Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/lib/CodeGen/CodeGenPrepare.cpp
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//===- CodeGenPrepare.cpp - Prepare a function for code generation --------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass munges the code in the input function to better prepare it for
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// SelectionDAG-based code generation. This works around limitations in it's
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// basic-block-at-a-time approach. It should eventually be removed.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ADT/APInt.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/MapVector.h"
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#include "llvm/ADT/PointerIntPair.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/Analysis/BlockFrequencyInfo.h"
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#include "llvm/Analysis/BranchProbabilityInfo.h"
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#include "llvm/Analysis/ConstantFolding.h"
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#include "llvm/Analysis/InstructionSimplify.h"
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#include "llvm/Analysis/LoopInfo.h"
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#include "llvm/Analysis/MemoryBuiltins.h"
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#include "llvm/Analysis/ProfileSummaryInfo.h"
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#include "llvm/Analysis/TargetLibraryInfo.h"
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#include "llvm/Analysis/TargetTransformInfo.h"
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#include "llvm/Transforms/Utils/Local.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/Analysis/VectorUtils.h"
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#include "llvm/CodeGen/Analysis.h"
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#include "llvm/CodeGen/ISDOpcodes.h"
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#include "llvm/CodeGen/SelectionDAGNodes.h"
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#include "llvm/CodeGen/TargetLowering.h"
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#include "llvm/CodeGen/TargetPassConfig.h"
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#include "llvm/CodeGen/TargetSubtargetInfo.h"
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#include "llvm/CodeGen/ValueTypes.h"
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#include "llvm/Config/llvm-config.h"
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#include "llvm/IR/Argument.h"
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#include "llvm/IR/Attributes.h"
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#include "llvm/IR/BasicBlock.h"
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#include "llvm/IR/CallSite.h"
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#include "llvm/IR/Constant.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Dominators.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/GetElementPtrTypeIterator.h"
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#include "llvm/IR/GlobalValue.h"
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#include "llvm/IR/GlobalVariable.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/InlineAsm.h"
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#include "llvm/IR/InstrTypes.h"
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#include "llvm/IR/Instruction.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/IntrinsicInst.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/MDBuilder.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/Operator.h"
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#include "llvm/IR/PatternMatch.h"
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#include "llvm/IR/Statepoint.h"
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#include "llvm/IR/Type.h"
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#include "llvm/IR/Use.h"
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#include "llvm/IR/User.h"
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#include "llvm/IR/Value.h"
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#include "llvm/IR/ValueHandle.h"
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#include "llvm/IR/ValueMap.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/BlockFrequency.h"
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#include "llvm/Support/BranchProbability.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/MachineValueType.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetOptions.h"
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#include "llvm/Transforms/Utils/BasicBlockUtils.h"
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#include "llvm/Transforms/Utils/BypassSlowDivision.h"
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#include "llvm/Transforms/Utils/SimplifyLibCalls.h"
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#include <algorithm>
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#include <cassert>
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#include <cstdint>
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#include <iterator>
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#include <limits>
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#include <memory>
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#include <utility>
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#include <vector>
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using namespace llvm;
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using namespace llvm::PatternMatch;
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#define DEBUG_TYPE "codegenprepare"
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STATISTIC(NumBlocksElim, "Number of blocks eliminated");
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STATISTIC(NumPHIsElim,   "Number of trivial PHIs eliminated");
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STATISTIC(NumGEPsElim,   "Number of GEPs converted to casts");
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STATISTIC(NumCmpUses, "Number of uses of Cmp expressions replaced with uses of "
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                      "sunken Cmps");
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STATISTIC(NumCastUses, "Number of uses of Cast expressions replaced with uses "
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                       "of sunken Casts");
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STATISTIC(NumMemoryInsts, "Number of memory instructions whose address "
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                          "computations were sunk");
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STATISTIC(NumMemoryInstsPhiCreated,
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          "Number of phis created when address "
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          "computations were sunk to memory instructions");
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STATISTIC(NumMemoryInstsSelectCreated,
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          "Number of select created when address "
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          "computations were sunk to memory instructions");
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STATISTIC(NumExtsMoved,  "Number of [s|z]ext instructions combined with loads");
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STATISTIC(NumExtUses,    "Number of uses of [s|z]ext instructions optimized");
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STATISTIC(NumAndsAdded,
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          "Number of and mask instructions added to form ext loads");
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STATISTIC(NumAndUses, "Number of uses of and mask instructions optimized");
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STATISTIC(NumRetsDup,    "Number of return instructions duplicated");
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STATISTIC(NumDbgValueMoved, "Number of debug value instructions moved");
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STATISTIC(NumSelectsExpanded, "Number of selects turned into branches");
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STATISTIC(NumStoreExtractExposed, "Number of store(extractelement) exposed");
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static cl::opt<bool> DisableBranchOpts(
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  "disable-cgp-branch-opts", cl::Hidden, cl::init(false),
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  cl::desc("Disable branch optimizations in CodeGenPrepare"));
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static cl::opt<bool>
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    DisableGCOpts("disable-cgp-gc-opts", cl::Hidden, cl::init(false),
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                  cl::desc("Disable GC optimizations in CodeGenPrepare"));
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static cl::opt<bool> DisableSelectToBranch(
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  "disable-cgp-select2branch", cl::Hidden, cl::init(false),
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  cl::desc("Disable select to branch conversion."));
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static cl::opt<bool> AddrSinkUsingGEPs(
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  "addr-sink-using-gep", cl::Hidden, cl::init(true),
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  cl::desc("Address sinking in CGP using GEPs."));
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static cl::opt<bool> EnableAndCmpSinking(
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   "enable-andcmp-sinking", cl::Hidden, cl::init(true),
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   cl::desc("Enable sinkinig and/cmp into branches."));
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static cl::opt<bool> DisableStoreExtract(
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    "disable-cgp-store-extract", cl::Hidden, cl::init(false),
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    cl::desc("Disable store(extract) optimizations in CodeGenPrepare"));
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static cl::opt<bool> StressStoreExtract(
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    "stress-cgp-store-extract", cl::Hidden, cl::init(false),
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    cl::desc("Stress test store(extract) optimizations in CodeGenPrepare"));
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static cl::opt<bool> DisableExtLdPromotion(
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    "disable-cgp-ext-ld-promotion", cl::Hidden, cl::init(false),
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    cl::desc("Disable ext(promotable(ld)) -> promoted(ext(ld)) optimization in "
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             "CodeGenPrepare"));
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static cl::opt<bool> StressExtLdPromotion(
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    "stress-cgp-ext-ld-promotion", cl::Hidden, cl::init(false),
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    cl::desc("Stress test ext(promotable(ld)) -> promoted(ext(ld)) "
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             "optimization in CodeGenPrepare"));
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static cl::opt<bool> DisablePreheaderProtect(
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    "disable-preheader-prot", cl::Hidden, cl::init(false),
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    cl::desc("Disable protection against removing loop preheaders"));
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static cl::opt<bool> ProfileGuidedSectionPrefix(
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    "profile-guided-section-prefix", cl::Hidden, cl::init(true), cl::ZeroOrMore,
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    cl::desc("Use profile info to add section prefix for hot/cold functions"));
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static cl::opt<unsigned> FreqRatioToSkipMerge(
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    "cgp-freq-ratio-to-skip-merge", cl::Hidden, cl::init(2),
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    cl::desc("Skip merging empty blocks if (frequency of empty block) / "
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             "(frequency of destination block) is greater than this ratio"));
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static cl::opt<bool> ForceSplitStore(
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    "force-split-store", cl::Hidden, cl::init(false),
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    cl::desc("Force store splitting no matter what the target query says."));
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static cl::opt<bool>
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EnableTypePromotionMerge("cgp-type-promotion-merge", cl::Hidden,
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    cl::desc("Enable merging of redundant sexts when one is dominating"
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    " the other."), cl::init(true));
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static cl::opt<bool> DisableComplexAddrModes(
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    "disable-complex-addr-modes", cl::Hidden, cl::init(false),
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    cl::desc("Disables combining addressing modes with different parts "
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             "in optimizeMemoryInst."));
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static cl::opt<bool>
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AddrSinkNewPhis("addr-sink-new-phis", cl::Hidden, cl::init(false),
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                cl::desc("Allow creation of Phis in Address sinking."));
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static cl::opt<bool>
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AddrSinkNewSelects("addr-sink-new-select", cl::Hidden, cl::init(true),
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                   cl::desc("Allow creation of selects in Address sinking."));
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static cl::opt<bool> AddrSinkCombineBaseReg(
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    "addr-sink-combine-base-reg", cl::Hidden, cl::init(true),
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    cl::desc("Allow combining of BaseReg field in Address sinking."));
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static cl::opt<bool> AddrSinkCombineBaseGV(
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    "addr-sink-combine-base-gv", cl::Hidden, cl::init(true),
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    cl::desc("Allow combining of BaseGV field in Address sinking."));
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static cl::opt<bool> AddrSinkCombineBaseOffs(
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    "addr-sink-combine-base-offs", cl::Hidden, cl::init(true),
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    cl::desc("Allow combining of BaseOffs field in Address sinking."));
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static cl::opt<bool> AddrSinkCombineScaledReg(
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    "addr-sink-combine-scaled-reg", cl::Hidden, cl::init(true),
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    cl::desc("Allow combining of ScaledReg field in Address sinking."));
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static cl::opt<bool>
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    EnableGEPOffsetSplit("cgp-split-large-offset-gep", cl::Hidden,
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                         cl::init(true),
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                         cl::desc("Enable splitting large offset of GEP."));
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namespace {
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enum ExtType {
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  ZeroExtension,   // Zero extension has been seen.
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  SignExtension,   // Sign extension has been seen.
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  BothExtension    // This extension type is used if we saw sext after
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                   // ZeroExtension had been set, or if we saw zext after
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                   // SignExtension had been set. It makes the type
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                   // information of a promoted instruction invalid.
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};
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using SetOfInstrs = SmallPtrSet<Instruction *, 16>;
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using TypeIsSExt = PointerIntPair<Type *, 2, ExtType>;
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using InstrToOrigTy = DenseMap<Instruction *, TypeIsSExt>;
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using SExts = SmallVector<Instruction *, 16>;
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using ValueToSExts = DenseMap<Value *, SExts>;
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class TypePromotionTransaction;
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  class CodeGenPrepare : public FunctionPass {
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    const TargetMachine *TM = nullptr;
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    const TargetSubtargetInfo *SubtargetInfo;
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    const TargetLowering *TLI = nullptr;
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    const TargetRegisterInfo *TRI;
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    const TargetTransformInfo *TTI = nullptr;
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    const TargetLibraryInfo *TLInfo;
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    const LoopInfo *LI;
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    std::unique_ptr<BlockFrequencyInfo> BFI;
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    std::unique_ptr<BranchProbabilityInfo> BPI;
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    /// As we scan instructions optimizing them, this is the next instruction
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    /// to optimize. Transforms that can invalidate this should update it.
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    BasicBlock::iterator CurInstIterator;
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    /// Keeps track of non-local addresses that have been sunk into a block.
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    /// This allows us to avoid inserting duplicate code for blocks with
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    /// multiple load/stores of the same address. The usage of WeakTrackingVH
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    /// enables SunkAddrs to be treated as a cache whose entries can be
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    /// invalidated if a sunken address computation has been erased.
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    ValueMap<Value*, WeakTrackingVH> SunkAddrs;
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    /// Keeps track of all instructions inserted for the current function.
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    SetOfInstrs InsertedInsts;
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    /// Keeps track of the type of the related instruction before their
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    /// promotion for the current function.
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    InstrToOrigTy PromotedInsts;
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    /// Keep track of instructions removed during promotion.
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    SetOfInstrs RemovedInsts;
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    /// Keep track of sext chains based on their initial value.
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    DenseMap<Value *, Instruction *> SeenChainsForSExt;
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    /// Keep track of GEPs accessing the same data structures such as structs or
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    /// arrays that are candidates to be split later because of their large
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    /// size.
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    MapVector<
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        AssertingVH<Value>,
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        SmallVector<std::pair<AssertingVH<GetElementPtrInst>, int64_t>, 32>>
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        LargeOffsetGEPMap;
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    /// Keep track of new GEP base after splitting the GEPs having large offset.
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    SmallSet<AssertingVH<Value>, 2> NewGEPBases;
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    /// Map serial numbers to Large offset GEPs.
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    DenseMap<AssertingVH<GetElementPtrInst>, int> LargeOffsetGEPID;
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    /// Keep track of SExt promoted.
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    ValueToSExts ValToSExtendedUses;
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    /// True if optimizing for size.
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    bool OptSize;
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    /// DataLayout for the Function being processed.
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    const DataLayout *DL = nullptr;
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    /// Building the dominator tree can be expensive, so we only build it
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    /// lazily and update it when required.
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    std::unique_ptr<DominatorTree> DT;
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  public:
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    static char ID; // Pass identification, replacement for typeid
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34.6k
    CodeGenPrepare() : FunctionPass(ID) {
310
34.6k
      initializeCodeGenPreparePass(*PassRegistry::getPassRegistry());
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34.6k
    }
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    bool runOnFunction(Function &F) override;
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490k
    StringRef getPassName() const override { return "CodeGen Prepare"; }
316
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34.4k
    void getAnalysisUsage(AnalysisUsage &AU) const override {
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34.4k
      // FIXME: When we can selectively preserve passes, preserve the domtree.
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34.4k
      AU.addRequired<ProfileSummaryInfoWrapperPass>();
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34.4k
      AU.addRequired<TargetLibraryInfoWrapperPass>();
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34.4k
      AU.addRequired<TargetTransformInfoWrapperPass>();
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34.4k
      AU.addRequired<LoopInfoWrapperPass>();
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34.4k
    }
324
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  private:
326
    template <typename F>
327
3.42k
    void resetIteratorIfInvalidatedWhileCalling(BasicBlock *BB, F f) {
328
3.42k
      // Substituting can cause recursive simplifications, which can invalidate
329
3.42k
      // our iterator.  Use a WeakTrackingVH to hold onto it in case this
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3.42k
      // happens.
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3.42k
      Value *CurValue = &*CurInstIterator;
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3.42k
      WeakTrackingVH IterHandle(CurValue);
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3.42k
334
3.42k
      f();
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3.42k
336
3.42k
      // If the iterator instruction was recursively deleted, start over at the
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3.42k
      // start of the block.
338
3.42k
      if (IterHandle != CurValue) {
339
9
        CurInstIterator = BB->begin();
340
9
        SunkAddrs.clear();
341
9
      }
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3.42k
    }
CodeGenPrepare.cpp:void (anonymous namespace)::CodeGenPrepare::resetIteratorIfInvalidatedWhileCalling<(anonymous namespace)::CodeGenPrepare::optimizeCallInst(llvm::CallInst*, bool&)::$_1>(llvm::BasicBlock*, (anonymous namespace)::CodeGenPrepare::optimizeCallInst(llvm::CallInst*, bool&)::$_1)
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Source
327
4
    void resetIteratorIfInvalidatedWhileCalling(BasicBlock *BB, F f) {
328
4
      // Substituting can cause recursive simplifications, which can invalidate
329
4
      // our iterator.  Use a WeakTrackingVH to hold onto it in case this
330
4
      // happens.
331
4
      Value *CurValue = &*CurInstIterator;
332
4
      WeakTrackingVH IterHandle(CurValue);
333
4
334
4
      f();
335
4
336
4
      // If the iterator instruction was recursively deleted, start over at the
337
4
      // start of the block.
338
4
      if (IterHandle != CurValue) {
339
2
        CurInstIterator = BB->begin();
340
2
        SunkAddrs.clear();
341
2
      }
342
4
    }
CodeGenPrepare.cpp:void (anonymous namespace)::CodeGenPrepare::resetIteratorIfInvalidatedWhileCalling<(anonymous namespace)::CodeGenPrepare::optimizeCallInst(llvm::CallInst*, bool&)::$_2>(llvm::BasicBlock*, (anonymous namespace)::CodeGenPrepare::optimizeCallInst(llvm::CallInst*, bool&)::$_2)
Line
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Source
327
3.40k
    void resetIteratorIfInvalidatedWhileCalling(BasicBlock *BB, F f) {
328
3.40k
      // Substituting can cause recursive simplifications, which can invalidate
329
3.40k
      // our iterator.  Use a WeakTrackingVH to hold onto it in case this
330
3.40k
      // happens.
331
3.40k
      Value *CurValue = &*CurInstIterator;
332
3.40k
      WeakTrackingVH IterHandle(CurValue);
333
3.40k
334
3.40k
      f();
335
3.40k
336
3.40k
      // If the iterator instruction was recursively deleted, start over at the
337
3.40k
      // start of the block.
338
3.40k
      if (IterHandle != CurValue) {
339
6
        CurInstIterator = BB->begin();
340
6
        SunkAddrs.clear();
341
6
      }
342
3.40k
    }
CodeGenPrepare.cpp:void (anonymous namespace)::CodeGenPrepare::resetIteratorIfInvalidatedWhileCalling<(anonymous namespace)::CodeGenPrepare::optimizeCallInst(llvm::CallInst*, bool&)::$_3>(llvm::BasicBlock*, (anonymous namespace)::CodeGenPrepare::optimizeCallInst(llvm::CallInst*, bool&)::$_3)
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Source
327
19
    void resetIteratorIfInvalidatedWhileCalling(BasicBlock *BB, F f) {
328
19
      // Substituting can cause recursive simplifications, which can invalidate
329
19
      // our iterator.  Use a WeakTrackingVH to hold onto it in case this
330
19
      // happens.
331
19
      Value *CurValue = &*CurInstIterator;
332
19
      WeakTrackingVH IterHandle(CurValue);
333
19
334
19
      f();
335
19
336
19
      // If the iterator instruction was recursively deleted, start over at the
337
19
      // start of the block.
338
19
      if (IterHandle != CurValue) {
339
1
        CurInstIterator = BB->begin();
340
1
        SunkAddrs.clear();
341
1
      }
342
19
    }
343
344
    // Get the DominatorTree, building if necessary.
345
26.4k
    DominatorTree &getDT(Function &F) {
346
26.4k
      if (!DT)
347
1.17k
        DT = llvm::make_unique<DominatorTree>(F);
348
26.4k
      return *DT;
349
26.4k
    }
350
351
    bool eliminateFallThrough(Function &F);
352
    bool eliminateMostlyEmptyBlocks(Function &F);
353
    BasicBlock *findDestBlockOfMergeableEmptyBlock(BasicBlock *BB);
354
    bool canMergeBlocks(const BasicBlock *BB, const BasicBlock *DestBB) const;
355
    void eliminateMostlyEmptyBlock(BasicBlock *BB);
356
    bool isMergingEmptyBlockProfitable(BasicBlock *BB, BasicBlock *DestBB,
357
                                       bool isPreheader);
358
    bool optimizeBlock(BasicBlock &BB, bool &ModifiedDT);
359
    bool optimizeInst(Instruction *I, bool &ModifiedDT);
360
    bool optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
361
                            Type *AccessTy, unsigned AddrSpace);
362
    bool optimizeInlineAsmInst(CallInst *CS);
363
    bool optimizeCallInst(CallInst *CI, bool &ModifiedDT);
364
    bool optimizeExt(Instruction *&I);
365
    bool optimizeExtUses(Instruction *I);
366
    bool optimizeLoadExt(LoadInst *Load);
367
    bool optimizeShiftInst(BinaryOperator *BO);
368
    bool optimizeSelectInst(SelectInst *SI);
369
    bool optimizeShuffleVectorInst(ShuffleVectorInst *SVI);
370
    bool optimizeSwitchInst(SwitchInst *SI);
371
    bool optimizeExtractElementInst(Instruction *Inst);
372
    bool dupRetToEnableTailCallOpts(BasicBlock *BB, bool &ModifiedDT);
373
    bool placeDbgValues(Function &F);
374
    bool canFormExtLd(const SmallVectorImpl<Instruction *> &MovedExts,
375
                      LoadInst *&LI, Instruction *&Inst, bool HasPromoted);
376
    bool tryToPromoteExts(TypePromotionTransaction &TPT,
377
                          const SmallVectorImpl<Instruction *> &Exts,
378
                          SmallVectorImpl<Instruction *> &ProfitablyMovedExts,
379
                          unsigned CreatedInstsCost = 0);
380
    bool mergeSExts(Function &F);
381
    bool splitLargeGEPOffsets();
382
    bool performAddressTypePromotion(
383
        Instruction *&Inst,
384
        bool AllowPromotionWithoutCommonHeader,
385
        bool HasPromoted, TypePromotionTransaction &TPT,
386
        SmallVectorImpl<Instruction *> &SpeculativelyMovedExts);
387
    bool splitBranchCondition(Function &F, bool &ModifiedDT);
388
    bool simplifyOffsetableRelocate(Instruction &I);
389
390
    bool tryToSinkFreeOperands(Instruction *I);
391
    bool replaceMathCmpWithIntrinsic(BinaryOperator *BO, CmpInst *Cmp,
392
                                     Intrinsic::ID IID);
393
    bool optimizeCmp(CmpInst *Cmp, bool &ModifiedDT);
394
    bool combineToUSubWithOverflow(CmpInst *Cmp, bool &ModifiedDT);
395
    bool combineToUAddWithOverflow(CmpInst *Cmp, bool &ModifiedDT);
396
  };
397
398
} // end anonymous namespace
399
400
char CodeGenPrepare::ID = 0;
401
402
49.1k
INITIALIZE_PASS_BEGIN(CodeGenPrepare, DEBUG_TYPE,
403
49.1k
                      "Optimize for code generation", false, false)
404
49.1k
INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
405
49.1k
INITIALIZE_PASS_END(CodeGenPrepare, DEBUG_TYPE,
406
                    "Optimize for code generation", false, false)
407
408
34.5k
FunctionPass *llvm::createCodeGenPreparePass() { return new CodeGenPrepare(); }
409
410
490k
bool CodeGenPrepare::runOnFunction(Function &F) {
411
490k
  if (skipFunction(F))
412
272
    return false;
413
490k
414
490k
  DL = &F.getParent()->getDataLayout();
415
490k
416
490k
  bool EverMadeChange = false;
417
490k
  // Clear per function information.
418
490k
  InsertedInsts.clear();
419
490k
  PromotedInsts.clear();
420
490k
421
490k
  if (auto *TPC = getAnalysisIfAvailable<TargetPassConfig>()) {
422
490k
    TM = &TPC->getTM<TargetMachine>();
423
490k
    SubtargetInfo = TM->getSubtargetImpl(F);
424
490k
    TLI = SubtargetInfo->getTargetLowering();
425
490k
    TRI = SubtargetInfo->getRegisterInfo();
426
490k
  }
427
490k
  TLInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
428
490k
  TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
429
490k
  LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
430
490k
  BPI.reset(new BranchProbabilityInfo(F, *LI));
431
490k
  BFI.reset(new BlockFrequencyInfo(F, *BPI, *LI));
432
490k
  OptSize = F.hasOptSize();
433
490k
434
490k
  ProfileSummaryInfo *PSI =
435
490k
      &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
436
490k
  if (ProfileGuidedSectionPrefix) {
437
490k
    if (PSI->isFunctionHotInCallGraph(&F, *BFI))
438
20
      F.setSectionPrefix(".hot");
439
490k
    else if (PSI->isFunctionColdInCallGraph(&F, *BFI))
440
12
      F.setSectionPrefix(".unlikely");
441
490k
  }
442
490k
443
490k
  /// This optimization identifies DIV instructions that can be
444
490k
  /// profitably bypassed and carried out with a shorter, faster divide.
445
490k
  if (!OptSize && 
!PSI->hasHugeWorkingSetSize()486k
&&
TLI486k
&&
446
490k
      
TLI->isSlowDivBypassed()486k
) {
447
11.6k
    const DenseMap<unsigned int, unsigned int> &BypassWidths =
448
11.6k
       TLI->getBypassSlowDivWidths();
449
11.6k
    BasicBlock* BB = &*F.begin();
450
89.7k
    while (BB != nullptr) {
451
78.1k
      // bypassSlowDivision may create new BBs, but we don't want to reapply the
452
78.1k
      // optimization to those blocks.
453
78.1k
      BasicBlock* Next = BB->getNextNode();
454
78.1k
      EverMadeChange |= bypassSlowDivision(BB, BypassWidths);
455
78.1k
      BB = Next;
456
78.1k
    }
457
11.6k
  }
458
490k
459
490k
  // Eliminate blocks that contain only PHI nodes and an
460
490k
  // unconditional branch.
461
490k
  EverMadeChange |= eliminateMostlyEmptyBlocks(F);
462
490k
463
490k
  bool ModifiedDT = false;
464
490k
  if (!DisableBranchOpts)
465
490k
    EverMadeChange |= splitBranchCondition(F, ModifiedDT);
466
490k
467
490k
  // Split some critical edges where one of the sources is an indirect branch,
468
490k
  // to help generate sane code for PHIs involving such edges.
469
490k
  EverMadeChange |= SplitIndirectBrCriticalEdges(F);
470
490k
471
490k
  bool MadeChange = true;
472
1.13M
  while (MadeChange) {
473
644k
    MadeChange = false;
474
644k
    DT.reset();
475
6.95M
    for (Function::iterator I = F.begin(); I != F.end(); ) {
476
6.33M
      BasicBlock *BB = &*I++;
477
6.33M
      bool ModifiedDTOnIteration = false;
478
6.33M
      MadeChange |= optimizeBlock(*BB, ModifiedDTOnIteration);
479
6.33M
480
6.33M
      // Restart BB iteration if the dominator tree of the Function was changed
481
6.33M
      if (ModifiedDTOnIteration)
482
24.5k
        break;
483
6.33M
    }
484
644k
    if (EnableTypePromotionMerge && 
!ValToSExtendedUses.empty()644k
)
485
26.5k
      MadeChange |= mergeSExts(F);
486
644k
    if (!LargeOffsetGEPMap.empty())
487
4.26k
      MadeChange |= splitLargeGEPOffsets();
488
644k
489
644k
    // Really free removed instructions during promotion.
490
644k
    for (Instruction *I : RemovedInsts)
491
3.54k
      I->deleteValue();
492
644k
493
644k
    EverMadeChange |= MadeChange;
494
644k
    SeenChainsForSExt.clear();
495
644k
    ValToSExtendedUses.clear();
496
644k
    RemovedInsts.clear();
497
644k
    LargeOffsetGEPMap.clear();
498
644k
    LargeOffsetGEPID.clear();
499
644k
  }
500
490k
501
490k
  SunkAddrs.clear();
502
490k
503
490k
  if (!DisableBranchOpts) {
504
490k
    MadeChange = false;
505
490k
    // Use a set vector to get deterministic iteration order. The order the
506
490k
    // blocks are removed may affect whether or not PHI nodes in successors
507
490k
    // are removed.
508
490k
    SmallSetVector<BasicBlock*, 8> WorkList;
509
2.56M
    for (BasicBlock &BB : F) {
510
2.56M
      SmallVector<BasicBlock *, 2> Successors(succ_begin(&BB), succ_end(&BB));
511
2.56M
      MadeChange |= ConstantFoldTerminator(&BB, true);
512
2.56M
      if (!MadeChange) 
continue2.55M
;
513
5.17k
514
5.17k
      for (SmallVectorImpl<BasicBlock*>::iterator
515
13.3k
             II = Successors.begin(), IE = Successors.end(); II != IE; 
++II8.14k
)
516
8.14k
        if (pred_begin(*II) == pred_end(*II))
517
1.11k
          WorkList.insert(*II);
518
5.17k
    }
519
490k
520
490k
    // Delete the dead blocks and any of their dead successors.
521
490k
    MadeChange |= !WorkList.empty();
522
492k
    while (!WorkList.empty()) {
523
1.71k
      BasicBlock *BB = WorkList.pop_back_val();
524
1.71k
      SmallVector<BasicBlock*, 2> Successors(succ_begin(BB), succ_end(BB));
525
1.71k
526
1.71k
      DeleteDeadBlock(BB);
527
1.71k
528
1.71k
      for (SmallVectorImpl<BasicBlock*>::iterator
529
3.12k
             II = Successors.begin(), IE = Successors.end(); II != IE; 
++II1.40k
)
530
1.40k
        if (pred_begin(*II) == pred_end(*II))
531
773
          WorkList.insert(*II);
532
1.71k
    }
533
490k
534
490k
    // Merge pairs of basic blocks with unconditional branches, connected by
535
490k
    // a single edge.
536
490k
    if (EverMadeChange || 
MadeChange362k
)
537
128k
      MadeChange |= eliminateFallThrough(F);
538
490k
539
490k
    EverMadeChange |= MadeChange;
540
490k
  }
541
490k
542
490k
  if (
!DisableGCOpts490k
) {
543
490k
    SmallVector<Instruction *, 2> Statepoints;
544
490k
    for (BasicBlock &BB : F)
545
2.55M
      for (Instruction &I : BB)
546
15.3M
        if (isStatepoint(I))
547
92
          Statepoints.push_back(&I);
548
490k
    for (auto &I : Statepoints)
549
92
      EverMadeChange |= simplifyOffsetableRelocate(*I);
550
490k
  }
551
490k
552
490k
  // Do this last to clean up use-before-def scenarios introduced by other
553
490k
  // preparatory transforms.
554
490k
  EverMadeChange |= placeDbgValues(F);
555
490k
556
490k
  return EverMadeChange;
557
490k
}
558
559
/// Merge basic blocks which are connected by a single edge, where one of the
560
/// basic blocks has a single successor pointing to the other basic block,
561
/// which has a single predecessor.
562
128k
bool CodeGenPrepare::eliminateFallThrough(Function &F) {
563
128k
  bool Changed = false;
564
128k
  // Scan all of the blocks in the function, except for the entry block.
565
128k
  // Use a temporary array to avoid iterator being invalidated when
566
128k
  // deleting blocks.
567
128k
  SmallVector<WeakTrackingVH, 16> Blocks;
568
128k
  for (auto &Block : llvm::make_range(std::next(F.begin()), F.end()))
569
1.93M
    Blocks.push_back(&Block);
570
128k
571
1.93M
  for (auto &Block : Blocks) {
572
1.93M
    auto *BB = cast_or_null<BasicBlock>(Block);
573
1.93M
    if (!BB)
574
0
      continue;
575
1.93M
    // If the destination block has a single pred, then this is a trivial
576
1.93M
    // edge, just collapse it.
577
1.93M
    BasicBlock *SinglePred = BB->getSinglePredecessor();
578
1.93M
579
1.93M
    // Don't merge if BB's address is taken.
580
1.93M
    if (!SinglePred || 
SinglePred == BB1.25M
||
BB->hasAddressTaken()1.25M
)
continue679k
;
581
1.25M
582
1.25M
    BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator());
583
1.25M
    if (Term && 
!Term->isConditional()1.18M
) {
584
2.89k
      Changed = true;
585
2.89k
      LLVM_DEBUG(dbgs() << "To merge:\n" << *BB << "\n\n\n");
586
2.89k
587
2.89k
      // Merge BB into SinglePred and delete it.
588
2.89k
      MergeBlockIntoPredecessor(BB);
589
2.89k
    }
590
1.25M
  }
591
128k
  return Changed;
592
128k
}
593
594
/// Find a destination block from BB if BB is mergeable empty block.
595
2.21M
BasicBlock *CodeGenPrepare::findDestBlockOfMergeableEmptyBlock(BasicBlock *BB) {
596
2.21M
  // If this block doesn't end with an uncond branch, ignore it.
597
2.21M
  BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator());
598
2.21M
  if (!BI || 
!BI->isUnconditional()1.98M
)
599
1.26M
    return nullptr;
600
949k
601
949k
  // If the instruction before the branch (skipping debug info) isn't a phi
602
949k
  // node, then other stuff is happening here.
603
949k
  BasicBlock::iterator BBI = BI->getIterator();
604
949k
  if (BBI != BB->begin()) {
605
728k
    --BBI;
606
728k
    while (isa<DbgInfoIntrinsic>(BBI)) {
607
25
      if (BBI == BB->begin())
608
4
        break;
609
21
      --BBI;
610
21
    }
611
728k
    if (!isa<DbgInfoIntrinsic>(BBI) && 
!isa<PHINode>(BBI)728k
)
612
711k
      return nullptr;
613
238k
  }
614
238k
615
238k
  // Do not break infinite loops.
616
238k
  BasicBlock *DestBB = BI->getSuccessor(0);
617
238k
  if (DestBB == BB)
618
123
    return nullptr;
619
238k
620
238k
  if (!canMergeBlocks(BB, DestBB))
621
17.6k
    DestBB = nullptr;
622
238k
623
238k
  return DestBB;
624
238k
}
625
626
/// Eliminate blocks that contain only PHI nodes, debug info directives, and an
627
/// unconditional branch. Passes before isel (e.g. LSR/loopsimplify) often split
628
/// edges in ways that are non-optimal for isel. Start by eliminating these
629
/// blocks so we can split them the way we want them.
630
490k
bool CodeGenPrepare::eliminateMostlyEmptyBlocks(Function &F) {
631
490k
  SmallPtrSet<BasicBlock *, 16> Preheaders;
632
490k
  SmallVector<Loop *, 16> LoopList(LI->begin(), LI->end());
633
698k
  while (!LoopList.empty()) {
634
208k
    Loop *L = LoopList.pop_back_val();
635
208k
    LoopList.insert(LoopList.end(), L->begin(), L->end());
636
208k
    if (BasicBlock *Preheader = L->getLoopPreheader())
637
208k
      Preheaders.insert(Preheader);
638
208k
  }
639
490k
640
490k
  bool MadeChange = false;
641
490k
  // Copy blocks into a temporary array to avoid iterator invalidation issues
642
490k
  // as we remove them.
643
490k
  // Note that this intentionally skips the entry block.
644
490k
  SmallVector<WeakTrackingVH, 16> Blocks;
645
490k
  for (auto &Block : llvm::make_range(std::next(F.begin()), F.end()))
646
2.21M
    Blocks.push_back(&Block);
647
490k
648
2.21M
  for (auto &Block : Blocks) {
649
2.21M
    BasicBlock *BB = cast_or_null<BasicBlock>(Block);
650
2.21M
    if (!BB)
651
0
      continue;
652
2.21M
    BasicBlock *DestBB = findDestBlockOfMergeableEmptyBlock(BB);
653
2.21M
    if (!DestBB ||
654
2.21M
        
!isMergingEmptyBlockProfitable(BB, DestBB, Preheaders.count(BB))220k
)
655
2.07M
      continue;
656
136k
657
136k
    eliminateMostlyEmptyBlock(BB);
658
136k
    MadeChange = true;
659
136k
  }
660
490k
  return MadeChange;
661
490k
}
662
663
bool CodeGenPrepare::isMergingEmptyBlockProfitable(BasicBlock *BB,
664
                                                   BasicBlock *DestBB,
665
220k
                                                   bool isPreheader) {
666
220k
  // Do not delete loop preheaders if doing so would create a critical edge.
667
220k
  // Loop preheaders can be good locations to spill registers. If the
668
220k
  // preheader is deleted and we create a critical edge, registers may be
669
220k
  // spilled in the loop body instead.
670
220k
  if (!DisablePreheaderProtect && 
isPreheader220k
&&
671
220k
      
!(83.0k
BB->getSinglePredecessor()83.0k
&&
672
83.0k
        
BB->getSinglePredecessor()->getSingleSuccessor()77.3k
))
673
83.0k
    return false;
674
137k
675
137k
  // Skip merging if the block's successor is also a successor to any callbr
676
137k
  // that leads to this block.
677
137k
  // FIXME: Is this really needed? Is this a correctness issue?
678
292k
  
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); 137k
PI != E;
++PI155k
) {
679
155k
    if (auto *CBI = dyn_cast<CallBrInst>((*PI)->getTerminator()))
680
0
      for (unsigned i = 0, e = CBI->getNumSuccessors(); i != e; ++i)
681
0
        if (DestBB == CBI->getSuccessor(i))
682
0
          return false;
683
155k
  }
684
137k
685
137k
  // Try to skip merging if the unique predecessor of BB is terminated by a
686
137k
  // switch or indirect branch instruction, and BB is used as an incoming block
687
137k
  // of PHIs in DestBB. In such case, merging BB and DestBB would cause ISel to
688
137k
  // add COPY instructions in the predecessor of BB instead of BB (if it is not
689
137k
  // merged). Note that the critical edge created by merging such blocks wont be
690
137k
  // split in MachineSink because the jump table is not analyzable. By keeping
691
137k
  // such empty block (BB), ISel will place COPY instructions in BB, not in the
692
137k
  // predecessor of BB.
693
137k
  BasicBlock *Pred = BB->getUniquePredecessor();
694
137k
  if (!Pred ||
695
137k
      
!(126k
isa<SwitchInst>(Pred->getTerminator())126k
||
696
126k
        
isa<IndirectBrInst>(Pred->getTerminator())125k
))
697
135k
    return true;
698
1.44k
699
1.44k
  if (BB->getTerminator() != BB->getFirstNonPHIOrDbg())
700
0
    return true;
701
1.44k
702
1.44k
  // We use a simple cost heuristic which determine skipping merging is
703
1.44k
  // profitable if the cost of skipping merging is less than the cost of
704
1.44k
  // merging : Cost(skipping merging) < Cost(merging BB), where the
705
1.44k
  // Cost(skipping merging) is Freq(BB) * (Cost(Copy) + Cost(Branch)), and
706
1.44k
  // the Cost(merging BB) is Freq(Pred) * Cost(Copy).
707
1.44k
  // Assuming Cost(Copy) == Cost(Branch), we could simplify it to :
708
1.44k
  //   Freq(Pred) / Freq(BB) > 2.
709
1.44k
  // Note that if there are multiple empty blocks sharing the same incoming
710
1.44k
  // value for the PHIs in the DestBB, we consider them together. In such
711
1.44k
  // case, Cost(merging BB) will be the sum of their frequencies.
712
1.44k
713
1.44k
  if (!isa<PHINode>(DestBB->begin()))
714
646
    return true;
715
803
716
803
  SmallPtrSet<BasicBlock *, 16> SameIncomingValueBBs;
717
803
718
803
  // Find all other incoming blocks from which incoming values of all PHIs in
719
803
  // DestBB are the same as the ones from BB.
720
11.4k
  for (pred_iterator PI = pred_begin(DestBB), E = pred_end(DestBB); PI != E;
721
10.6k
       ++PI) {
722
10.6k
    BasicBlock *DestBBPred = *PI;
723
10.6k
    if (DestBBPred == BB)
724
803
      continue;
725
9.84k
726
10.4k
    
if (9.84k
llvm::all_of(DestBB->phis(), [&](const PHINode &DestPN) 9.84k
{
727
10.4k
          return DestPN.getIncomingValueForBlock(BB) ==
728
10.4k
                 DestPN.getIncomingValueForBlock(DestBBPred);
729
10.4k
        }))
730
386
      SameIncomingValueBBs.insert(DestBBPred);
731
9.84k
  }
732
803
733
803
  // See if all BB's incoming values are same as the value from Pred. In this
734
803
  // case, no reason to skip merging because COPYs are expected to be place in
735
803
  // Pred already.
736
803
  if (SameIncomingValueBBs.count(Pred))
737
6
    return true;
738
797
739
797
  BlockFrequency PredFreq = BFI->getBlockFreq(Pred);
740
797
  BlockFrequency BBFreq = BFI->getBlockFreq(BB);
741
797
742
797
  for (auto SameValueBB : SameIncomingValueBBs)
743
363
    if (SameValueBB->getUniquePredecessor() == Pred &&
744
363
        
DestBB == findDestBlockOfMergeableEmptyBlock(SameValueBB)49
)
745
15
      BBFreq += BFI->getBlockFreq(SameValueBB);
746
797
747
797
  return PredFreq.getFrequency() <=
748
797
         BBFreq.getFrequency() * FreqRatioToSkipMerge;
749
797
}
750
751
/// Return true if we can merge BB into DestBB if there is a single
752
/// unconditional branch between them, and BB contains no other non-phi
753
/// instructions.
754
bool CodeGenPrepare::canMergeBlocks(const BasicBlock *BB,
755
238k
                                    const BasicBlock *DestBB) const {
756
238k
  // We only want to eliminate blocks whose phi nodes are used by phi nodes in
757
238k
  // the successor.  If there are more complex condition (e.g. preheaders),
758
238k
  // don't mess around with them.
759
238k
  for (const PHINode &PN : BB->phis()) {
760
20.0k
    for (const User *U : PN.users()) {
761
20.0k
      const Instruction *UI = cast<Instruction>(U);
762
20.0k
      if (UI->getParent() != DestBB || 
!isa<PHINode>(UI)15.4k
)
763
7.98k
        return false;
764
12.0k
      // If User is inside DestBB block and it is a PHINode then check
765
12.0k
      // incoming value. If incoming value is not from BB then this is
766
12.0k
      // a complex condition (e.g. preheaders) we want to avoid here.
767
12.0k
      if (UI->getParent() == DestBB) {
768
12.0k
        if (const PHINode *UPN = dyn_cast<PHINode>(UI))
769
42.1k
          
for (unsigned I = 0, E = UPN->getNumIncomingValues(); 12.0k
I != E;
++I30.0k
) {
770
30.0k
            Instruction *Insn = dyn_cast<Instruction>(UPN->getIncomingValue(I));
771
30.0k
            if (Insn && 
Insn->getParent() == BB23.4k
&&
772
30.0k
                
Insn->getParent() != UPN->getIncomingBlock(I)12.0k
)
773
2
              return false;
774
30.0k
          }
775
12.0k
      }
776
12.0k
    }
777
19.8k
  }
778
238k
779
238k
  // If BB and DestBB contain any common predecessors, then the phi nodes in BB
780
238k
  // and DestBB may have conflicting incoming values for the block.  If so, we
781
238k
  // can't merge the block.
782
238k
  const PHINode *DestBBPN = dyn_cast<PHINode>(DestBB->begin());
783
230k
  if (!DestBBPN) 
return true88.7k
; // no conflict.
784
141k
785
141k
  // Collect the preds of BB.
786
141k
  SmallPtrSet<const BasicBlock*, 16> BBPreds;
787
141k
  if (const PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) {
788
9.16k
    // It is faster to get preds from a PHI than with pred_iterator.
789
29.8k
    for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; 
++i20.7k
)
790
20.7k
      BBPreds.insert(BBPN->getIncomingBlock(i));
791
132k
  } else {
792
132k
    BBPreds.insert(pred_begin(BB), pred_end(BB));
793
132k
  }
794
141k
795
141k
  // Walk the preds of DestBB.
796
598k
  for (unsigned i = 0, e = DestBBPN->getNumIncomingValues(); i != e; 
++i457k
) {
797
467k
    BasicBlock *Pred = DestBBPN->getIncomingBlock(i);
798
467k
    if (BBPreds.count(Pred)) {   // Common predecessor?
799
10.0k
      for (const PHINode &PN : DestBB->phis()) {
800
10.0k
        const Value *V1 = PN.getIncomingValueForBlock(Pred);
801
10.0k
        const Value *V2 = PN.getIncomingValueForBlock(BB);
802
10.0k
803
10.0k
        // If V2 is a phi node in BB, look up what the mapped value will be.
804
10.0k
        if (const PHINode *V2PN = dyn_cast<PHINode>(V2))
805
597
          if (V2PN->getParent() == BB)
806
206
            V2 = V2PN->getIncomingValueForBlock(Pred);
807
10.0k
808
10.0k
        // If there is a conflict, bail out.
809
10.0k
        if (V1 != V2) 
return false9.62k
;
810
10.0k
      }
811
9.65k
    }
812
467k
  }
813
141k
814
141k
  
return true131k
;
815
141k
}
816
817
/// Eliminate a basic block that has only phi's and an unconditional branch in
818
/// it.
819
136k
void CodeGenPrepare::eliminateMostlyEmptyBlock(BasicBlock *BB) {
820
136k
  BranchInst *BI = cast<BranchInst>(BB->getTerminator());
821
136k
  BasicBlock *DestBB = BI->getSuccessor(0);
822
136k
823
136k
  LLVM_DEBUG(dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n"
824
136k
                    << *BB << *DestBB);
825
136k
826
136k
  // If the destination block has a single pred, then this is a trivial edge,
827
136k
  // just collapse it.
828
136k
  if (BasicBlock *SinglePred = DestBB->getSinglePredecessor()) {
829
108
    if (SinglePred != DestBB) {
830
108
      assert(SinglePred == BB &&
831
108
             "Single predecessor not the same as predecessor");
832
108
      // Merge DestBB into SinglePred/BB and delete it.
833
108
      MergeBlockIntoPredecessor(DestBB);
834
108
      // Note: BB(=SinglePred) will not be deleted on this path.
835
108
      // DestBB(=its single successor) is the one that was deleted.
836
108
      LLVM_DEBUG(dbgs() << "AFTER:\n" << *SinglePred << "\n\n\n");
837
108
      return;
838
108
    }
839
136k
  }
840
136k
841
136k
  // Otherwise, we have multiple predecessors of BB.  Update the PHIs in DestBB
842
136k
  // to handle the new incoming edges it is about to have.
843
136k
  for (PHINode &PN : DestBB->phis()) {
844
70.4k
    // Remove the incoming value for BB, and remember it.
845
70.4k
    Value *InVal = PN.removeIncomingValue(BB, false);
846
70.4k
847
70.4k
    // Two options: either the InVal is a phi node defined in BB or it is some
848
70.4k
    // value that dominates BB.
849
70.4k
    PHINode *InValPhi = dyn_cast<PHINode>(InVal);
850
70.4k
    if (InValPhi && 
InValPhi->getParent() == BB25.2k
) {
851
6.27k
      // Add all of the input values of the input PHI as inputs of this phi.
852
21.3k
      for (unsigned i = 0, e = InValPhi->getNumIncomingValues(); i != e; 
++i15.0k
)
853
15.0k
        PN.addIncoming(InValPhi->getIncomingValue(i),
854
15.0k
                       InValPhi->getIncomingBlock(i));
855
64.1k
    } else {
856
64.1k
      // Otherwise, add one instance of the dominating value for each edge that
857
64.1k
      // we will be adding.
858
64.1k
      if (PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) {
859
1.40k
        for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; 
++i998
)
860
998
          PN.addIncoming(InVal, BBPN->getIncomingBlock(i));
861
63.7k
      } else {
862
129k
        for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; 
++PI66.1k
)
863
66.1k
          PN.addIncoming(InVal, *PI);
864
63.7k
      }
865
64.1k
    }
866
70.4k
  }
867
136k
868
136k
  // The PHIs are now updated, change everything that refers to BB to use
869
136k
  // DestBB and remove BB.
870
136k
  BB->replaceAllUsesWith(DestBB);
871
136k
  BB->eraseFromParent();
872
136k
  ++NumBlocksElim;
873
136k
874
136k
  LLVM_DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
875
136k
}
876
877
// Computes a map of base pointer relocation instructions to corresponding
878
// derived pointer relocation instructions given a vector of all relocate calls
879
static void computeBaseDerivedRelocateMap(
880
    const SmallVectorImpl<GCRelocateInst *> &AllRelocateCalls,
881
    DenseMap<GCRelocateInst *, SmallVector<GCRelocateInst *, 2>>
882
26
        &RelocateInstMap) {
883
26
  // Collect information in two maps: one primarily for locating the base object
884
26
  // while filling the second map; the second map is the final structure holding
885
26
  // a mapping between Base and corresponding Derived relocate calls
886
26
  DenseMap<std::pair<unsigned, unsigned>, GCRelocateInst *> RelocateIdxMap;
887
64
  for (auto *ThisRelocate : AllRelocateCalls) {
888
64
    auto K = std::make_pair(ThisRelocate->getBasePtrIndex(),
889
64
                            ThisRelocate->getDerivedPtrIndex());
890
64
    RelocateIdxMap.insert(std::make_pair(K, ThisRelocate));
891
64
  }
892
64
  for (auto &Item : RelocateIdxMap) {
893
64
    std::pair<unsigned, unsigned> Key = Item.first;
894
64
    if (Key.first == Key.second)
895
36
      // Base relocation: nothing to insert
896
36
      continue;
897
28
898
28
    GCRelocateInst *I = Item.second;
899
28
    auto BaseKey = std::make_pair(Key.first, Key.first);
900
28
901
28
    // We're iterating over RelocateIdxMap so we cannot modify it.
902
28
    auto MaybeBase = RelocateIdxMap.find(BaseKey);
903
28
    if (MaybeBase == RelocateIdxMap.end())
904
2
      // TODO: We might want to insert a new base object relocate and gep off
905
2
      // that, if there are enough derived object relocates.
906
2
      continue;
907
26
908
26
    RelocateInstMap[MaybeBase->second].push_back(I);
909
26
  }
910
26
}
911
912
// Accepts a GEP and extracts the operands into a vector provided they're all
913
// small integer constants
914
static bool getGEPSmallConstantIntOffsetV(GetElementPtrInst *GEP,
915
11
                                          SmallVectorImpl<Value *> &OffsetV) {
916
21
  for (unsigned i = 1; i < GEP->getNumOperands(); 
i++10
) {
917
13
    // Only accept small constant integer operands
918
13
    auto Op = dyn_cast<ConstantInt>(GEP->getOperand(i));
919
13
    if (!Op || 
Op->getZExtValue() > 2011
)
920
3
      return false;
921
13
  }
922
11
923
17
  
for (unsigned i = 1; 8
i < GEP->getNumOperands();
i++9
)
924
9
    OffsetV.push_back(GEP->getOperand(i));
925
8
  return true;
926
11
}
927
928
// Takes a RelocatedBase (base pointer relocation instruction) and Targets to
929
// replace, computes a replacement, and affects it.
930
static bool
931
simplifyRelocatesOffABase(GCRelocateInst *RelocatedBase,
932
18
                          const SmallVectorImpl<GCRelocateInst *> &Targets) {
933
18
  bool MadeChange = false;
934
18
  // We must ensure the relocation of derived pointer is defined after
935
18
  // relocation of base pointer. If we find a relocation corresponding to base
936
18
  // defined earlier than relocation of base then we move relocation of base
937
18
  // right before found relocation. We consider only relocation in the same
938
18
  // basic block as relocation of base. Relocations from other basic block will
939
18
  // be skipped by optimization and we do not care about them.
940
18
  for (auto R = RelocatedBase->getParent()->getFirstInsertionPt();
941
64
       &*R != RelocatedBase; 
++R46
)
942
52
    if (auto RI = dyn_cast<GCRelocateInst>(R))
943
12
      if (RI->getStatepoint() == RelocatedBase->getStatepoint())
944
6
        if (RI->getBasePtrIndex() == RelocatedBase->getBasePtrIndex()) {
945
6
          RelocatedBase->moveBefore(RI);
946
6
          break;
947
6
        }
948
18
949
26
  for (GCRelocateInst *ToReplace : Targets) {
950
26
    assert(ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() &&
951
26
           "Not relocating a derived object of the original base object");
952
26
    if (ToReplace->getBasePtrIndex() == ToReplace->getDerivedPtrIndex()) {
953
0
      // A duplicate relocate call. TODO: coalesce duplicates.
954
0
      continue;
955
0
    }
956
26
957
26
    if (RelocatedBase->getParent() != ToReplace->getParent()) {
958
1
      // Base and derived relocates are in different basic blocks.
959
1
      // In this case transform is only valid when base dominates derived
960
1
      // relocate. However it would be too expensive to check dominance
961
1
      // for each such relocate, so we skip the whole transformation.
962
1
      continue;
963
1
    }
964
25
965
25
    Value *Base = ToReplace->getBasePtr();
966
25
    auto Derived = dyn_cast<GetElementPtrInst>(ToReplace->getDerivedPtr());
967
25
    if (!Derived || 
Derived->getPointerOperand() != Base11
)
968
14
      continue;
969
11
970
11
    SmallVector<Value *, 2> OffsetV;
971
11
    if (!getGEPSmallConstantIntOffsetV(Derived, OffsetV))
972
3
      continue;
973
8
974
8
    // Create a Builder and replace the target callsite with a gep
975
8
    assert(RelocatedBase->getNextNode() &&
976
8
           "Should always have one since it's not a terminator");
977
8
978
8
    // Insert after RelocatedBase
979
8
    IRBuilder<> Builder(RelocatedBase->getNextNode());
980
8
    Builder.SetCurrentDebugLocation(ToReplace->getDebugLoc());
981
8
982
8
    // If gc_relocate does not match the actual type, cast it to the right type.
983
8
    // In theory, there must be a bitcast after gc_relocate if the type does not
984
8
    // match, and we should reuse it to get the derived pointer. But it could be
985
8
    // cases like this:
986
8
    // bb1:
987
8
    //  ...
988
8
    //  %g1 = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(...)
989
8
    //  br label %merge
990
8
    //
991
8
    // bb2:
992
8
    //  ...
993
8
    //  %g2 = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(...)
994
8
    //  br label %merge
995
8
    //
996
8
    // merge:
997
8
    //  %p1 = phi i8 addrspace(1)* [ %g1, %bb1 ], [ %g2, %bb2 ]
998
8
    //  %cast = bitcast i8 addrspace(1)* %p1 in to i32 addrspace(1)*
999
8
    //
1000
8
    // In this case, we can not find the bitcast any more. So we insert a new bitcast
1001
8
    // no matter there is already one or not. In this way, we can handle all cases, and
1002
8
    // the extra bitcast should be optimized away in later passes.
1003
8
    Value *ActualRelocatedBase = RelocatedBase;
1004
8
    if (RelocatedBase->getType() != Base->getType()) {
1005
0
      ActualRelocatedBase =
1006
0
          Builder.CreateBitCast(RelocatedBase, Base->getType());
1007
0
    }
1008
8
    Value *Replacement = Builder.CreateGEP(
1009
8
        Derived->getSourceElementType(), ActualRelocatedBase, makeArrayRef(OffsetV));
1010
8
    Replacement->takeName(ToReplace);
1011
8
    // If the newly generated derived pointer's type does not match the original derived
1012
8
    // pointer's type, cast the new derived pointer to match it. Same reasoning as above.
1013
8
    Value *ActualReplacement = Replacement;
1014
8
    if (Replacement->getType() != ToReplace->getType()) {
1015
0
      ActualReplacement =
1016
0
          Builder.CreateBitCast(Replacement, ToReplace->getType());
1017
0
    }
1018
8
    ToReplace->replaceAllUsesWith(ActualReplacement);
1019
8
    ToReplace->eraseFromParent();
1020
8
1021
8
    MadeChange = true;
1022
8
  }
1023
18
  return MadeChange;
1024
18
}
1025
1026
// Turns this:
1027
//
1028
// %base = ...
1029
// %ptr = gep %base + 15
1030
// %tok = statepoint (%fun, i32 0, i32 0, i32 0, %base, %ptr)
1031
// %base' = relocate(%tok, i32 4, i32 4)
1032
// %ptr' = relocate(%tok, i32 4, i32 5)
1033
// %val = load %ptr'
1034
//
1035
// into this:
1036
//
1037
// %base = ...
1038
// %ptr = gep %base + 15
1039
// %tok = statepoint (%fun, i32 0, i32 0, i32 0, %base, %ptr)
1040
// %base' = gc.relocate(%tok, i32 4, i32 4)
1041
// %ptr' = gep %base' + 15
1042
// %val = load %ptr'
1043
92
bool CodeGenPrepare::simplifyOffsetableRelocate(Instruction &I) {
1044
92
  bool MadeChange = false;
1045
92
  SmallVector<GCRelocateInst *, 2> AllRelocateCalls;
1046
92
1047
92
  for (auto *U : I.users())
1048
106
    if (GCRelocateInst *Relocate = dyn_cast<GCRelocateInst>(U))
1049
82
      // Collect all the relocate calls associated with a statepoint
1050
82
      AllRelocateCalls.push_back(Relocate);
1051
92
1052
92
  // We need atleast one base pointer relocation + one derived pointer
1053
92
  // relocation to mangle
1054
92
  if (AllRelocateCalls.size() < 2)
1055
66
    return false;
1056
26
1057
26
  // RelocateInstMap is a mapping from the base relocate instruction to the
1058
26
  // corresponding derived relocate instructions
1059
26
  DenseMap<GCRelocateInst *, SmallVector<GCRelocateInst *, 2>> RelocateInstMap;
1060
26
  computeBaseDerivedRelocateMap(AllRelocateCalls, RelocateInstMap);
1061
26
  if (RelocateInstMap.empty())
1062
8
    return false;
1063
18
1064
18
  for (auto &Item : RelocateInstMap)
1065
18
    // Item.first is the RelocatedBase to offset against
1066
18
    // Item.second is the vector of Targets to replace
1067
18
    MadeChange = simplifyRelocatesOffABase(Item.first, Item.second);
1068
18
  return MadeChange;
1069
18
}
1070
1071
/// Sink the specified cast instruction into its user blocks.
1072
4.15M
static bool SinkCast(CastInst *CI) {
1073
4.15M
  BasicBlock *DefBB = CI->getParent();
1074
4.15M
1075
4.15M
  /// InsertedCasts - Only insert a cast in each block once.
1076
4.15M
  DenseMap<BasicBlock*, CastInst*> InsertedCasts;
1077
4.15M
1078
4.15M
  bool MadeChange = false;
1079
4.15M
  for (Value::user_iterator UI = CI->user_begin(), E = CI->user_end();
1080
10.2M
       UI != E; ) {
1081
6.06M
    Use &TheUse = UI.getUse();
1082
6.06M
    Instruction *User = cast<Instruction>(*UI);
1083
6.06M
1084
6.06M
    // Figure out which BB this cast is used in.  For PHI's this is the
1085
6.06M
    // appropriate predecessor block.
1086
6.06M
    BasicBlock *UserBB = User->getParent();
1087
6.06M
    if (PHINode *PN = dyn_cast<PHINode>(User)) {
1088
250k
      UserBB = PN->getIncomingBlock(TheUse);
1089
250k
    }
1090
6.06M
1091
6.06M
    // Preincrement use iterator so we don't invalidate it.
1092
6.06M
    ++UI;
1093
6.06M
1094
6.06M
    // The first insertion point of a block containing an EH pad is after the
1095
6.06M
    // pad.  If the pad is the user, we cannot sink the cast past the pad.
1096
6.06M
    if (User->isEHPad())
1097
1
      continue;
1098
6.06M
1099
6.06M
    // If the block selected to receive the cast is an EH pad that does not
1100
6.06M
    // allow non-PHI instructions before the terminator, we can't sink the
1101
6.06M
    // cast.
1102
6.06M
    if (UserBB->getTerminator()->isEHPad())
1103
0
      continue;
1104
6.06M
1105
6.06M
    // If this user is in the same block as the cast, don't change the cast.
1106
6.06M
    if (UserBB == DefBB) 
continue5.70M
;
1107
353k
1108
353k
    // If we have already inserted a cast into this block, use it.
1109
353k
    CastInst *&InsertedCast = InsertedCasts[UserBB];
1110
353k
1111
353k
    if (!InsertedCast) {
1112
308k
      BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt();
1113
308k
      assert(InsertPt != UserBB->end());
1114
308k
      InsertedCast = CastInst::Create(CI->getOpcode(), CI->getOperand(0),
1115
308k
                                      CI->getType(), "", &*InsertPt);
1116
308k
      InsertedCast->setDebugLoc(CI->getDebugLoc());
1117
308k
    }
1118
353k
1119
353k
    // Replace a use of the cast with a use of the new cast.
1120
353k
    TheUse = InsertedCast;
1121
353k
    MadeChange = true;
1122
353k
    ++NumCastUses;
1123
353k
  }
1124
4.15M
1125
4.15M
  // If we removed all uses, nuke the cast.
1126
4.15M
  if (CI->use_empty()) {
1127
81.4k
    salvageDebugInfo(*CI);
1128
81.4k
    CI->eraseFromParent();
1129
81.4k
    MadeChange = true;
1130
81.4k
  }
1131
4.15M
1132
4.15M
  return MadeChange;
1133
4.15M
}
1134
1135
/// If the specified cast instruction is a noop copy (e.g. it's casting from
1136
/// one pointer type to another, i32->i8 on PPC), sink it into user blocks to
1137
/// reduce the number of virtual registers that must be created and coalesced.
1138
///
1139
/// Return true if any changes are made.
1140
static bool OptimizeNoopCopyExpression(CastInst *CI, const TargetLowering &TLI,
1141
5.64M
                                       const DataLayout &DL) {
1142
5.64M
  // Sink only "cheap" (or nop) address-space casts.  This is a weaker condition
1143
5.64M
  // than sinking only nop casts, but is helpful on some platforms.
1144
5.64M
  if (auto *ASC = dyn_cast<AddrSpaceCastInst>(CI)) {
1145
299
    if (!TLI.isFreeAddrSpaceCast(ASC->getSrcAddressSpace(),
1146
299
                                 ASC->getDestAddressSpace()))
1147
156
      return false;
1148
5.64M
  }
1149
5.64M
1150
5.64M
  // If this is a noop copy,
1151
5.64M
  EVT SrcVT = TLI.getValueType(DL, CI->getOperand(0)->getType());
1152
5.64M
  EVT DstVT = TLI.getValueType(DL, CI->getType());
1153
5.64M
1154
5.64M
  // This is an fp<->int conversion?
1155
5.64M
  if (SrcVT.isInteger() != DstVT.isInteger())
1156
269k
    return false;
1157
5.37M
1158
5.37M
  // If this is an extension, it will be a zero or sign extension, which
1159
5.37M
  // isn't a noop.
1160
5.37M
  if (SrcVT.bitsLT(DstVT)) 
return false856k
;
1161
4.52M
1162
4.52M
  // If these values will be promoted, find out what they will be promoted
1163
4.52M
  // to.  This helps us consider truncates on PPC as noop copies when they
1164
4.52M
  // are.
1165
4.52M
  if (TLI.getTypeAction(CI->getContext(), SrcVT) ==
1166
4.52M
      TargetLowering::TypePromoteInteger)
1167
11.1k
    SrcVT = TLI.getTypeToTransformTo(CI->getContext(), SrcVT);
1168
4.52M
  if (TLI.getTypeAction(CI->getContext(), DstVT) ==
1169
4.52M
      TargetLowering::TypePromoteInteger)
1170
90.3k
    DstVT = TLI.getTypeToTransformTo(CI->getContext(), DstVT);
1171
4.52M
1172
4.52M
  // If, after promotion, these are the same types, this is a noop copy.
1173
4.52M
  if (SrcVT != DstVT)
1174
379k
    return false;
1175
4.14M
1176
4.14M
  return SinkCast(CI);
1177
4.14M
}
1178
1179
bool CodeGenPrepare::replaceMathCmpWithIntrinsic(BinaryOperator *BO,
1180
                                                 CmpInst *Cmp,
1181
8.22k
                                                 Intrinsic::ID IID) {
1182
8.22k
  if (BO->getParent() != Cmp->getParent()) {
1183
5.30k
    // We used to use a dominator tree here to allow multi-block optimization.
1184
5.30k
    // But that was problematic because:
1185
5.30k
    // 1. It could cause a perf regression by hoisting the math op into the
1186
5.30k
    //    critical path.
1187
5.30k
    // 2. It could cause a perf regression by creating a value that was live
1188
5.30k
    //    across multiple blocks and increasing register pressure.
1189
5.30k
    // 3. Use of a dominator tree could cause large compile-time regression.
1190
5.30k
    //    This is because we recompute the DT on every change in the main CGP
1191
5.30k
    //    run-loop. The recomputing is probably unnecessary in many cases, so if
1192
5.30k
    //    that was fixed, using a DT here would be ok.
1193
5.30k
    return false;
1194
5.30k
  }
1195
2.92k
1196
2.92k
  // We allow matching the canonical IR (add X, C) back to (usubo X, -C).
1197
2.92k
  Value *Arg0 = BO->getOperand(0);
1198
2.92k
  Value *Arg1 = BO->getOperand(1);
1199
2.92k
  if (BO->getOpcode() == Instruction::Add &&
1200
2.92k
      
IID == Intrinsic::usub_with_overflow2.52k
) {
1201
129
    assert(isa<Constant>(Arg1) && "Unexpected input for usubo");
1202
129
    Arg1 = ConstantExpr::getNeg(cast<Constant>(Arg1));
1203
129
  }
1204
2.92k
1205
2.92k
  // Insert at the first instruction of the pair.
1206
2.92k
  Instruction *InsertPt = nullptr;
1207
210k
  for (Instruction &Iter : *Cmp->getParent()) {
1208
210k
    if (&Iter == BO || 
&Iter == Cmp207k
) {
1209
2.92k
      InsertPt = &Iter;
1210
2.92k
      break;
1211
2.92k
    }
1212
210k
  }
1213
2.92k
  assert(InsertPt != nullptr && "Parent block did not contain cmp or binop");
1214
2.92k
1215
2.92k
  IRBuilder<> Builder(InsertPt);
1216
2.92k
  Value *MathOV = Builder.CreateBinaryIntrinsic(IID, Arg0, Arg1);
1217
2.92k
  Value *Math = Builder.CreateExtractValue(MathOV, 0, "math");
1218
2.92k
  Value *OV = Builder.CreateExtractValue(MathOV, 1, "ov");
1219
2.92k
  BO->replaceAllUsesWith(Math);
1220
2.92k
  Cmp->replaceAllUsesWith(OV);
1221
2.92k
  BO->eraseFromParent();
1222
2.92k
  Cmp->eraseFromParent();
1223
2.92k
  return true;
1224
2.92k
}
1225
1226
/// Match special-case patterns that check for unsigned add overflow.
1227
static bool matchUAddWithOverflowConstantEdgeCases(CmpInst *Cmp,
1228
3.60M
                                                   BinaryOperator *&Add) {
1229
3.60M
  // Add = add A, 1; Cmp = icmp eq A,-1 (overflow if A is max val)
1230
3.60M
  // Add = add A,-1; Cmp = icmp ne A, 0 (overflow if A is non-zero)
1231
3.60M
  Value *A = Cmp->getOperand(0), *B = Cmp->getOperand(1);
1232
3.60M
1233
3.60M
  // We are not expecting non-canonical/degenerate code. Just bail out.
1234
3.60M
  if (isa<Constant>(A))
1235
2.07k
    return false;
1236
3.60M
1237
3.60M
  ICmpInst::Predicate Pred = Cmp->getPredicate();
1238
3.60M
  if (Pred == ICmpInst::ICMP_EQ && 
match(B, m_AllOnes())2.29M
)
1239
11.8k
    B = ConstantInt::get(B->getType(), 1);
1240
3.59M
  else if (Pred == ICmpInst::ICMP_NE && 
match(B, m_ZeroInt())137k
)
1241
112k
    B = ConstantInt::get(B->getType(), -1);
1242
3.47M
  else
1243
3.47M
    return false;
1244
124k
1245
124k
  // Check the users of the variable operand of the compare looking for an add
1246
124k
  // with the adjusted constant.
1247
353k
  
for (User *U : A->users())124k
{
1248
353k
    if (match(U, m_Add(m_Specific(A), m_Specific(B)))) {
1249
882
      Add = cast<BinaryOperator>(U);
1250
882
      return true;
1251
882
    }
1252
353k
  }
1253
124k
  
return false123k
;
1254
124k
}
1255
1256
/// Try to combine the compare into a call to the llvm.uadd.with.overflow
1257
/// intrinsic. Return true if any changes were made.
1258
bool CodeGenPrepare::combineToUAddWithOverflow(CmpInst *Cmp,
1259
3.60M
                                               bool &ModifiedDT) {
1260
3.60M
  Value *A, *B;
1261
3.60M
  BinaryOperator *Add;
1262
3.60M
  if (!match(Cmp, m_UAddWithOverflow(m_Value(A), m_Value(B), m_BinOp(Add))))
1263
3.60M
    if (!matchUAddWithOverflowConstantEdgeCases(Cmp, Add))
1264
3.60M
      return false;
1265
3.56k
1266
3.56k
  if (!TLI->shouldFormOverflowOp(ISD::UADDO,
1267
3.56k
                                 TLI->getValueType(*DL, Add->getType())))
1268
128
    return false;
1269
3.43k
1270
3.43k
  // We don't want to move around uses of condition values this late, so we
1271
3.43k
  // check if it is legal to create the call to the intrinsic in the basic
1272
3.43k
  // block containing the icmp.
1273
3.43k
  if (Add->getParent() != Cmp->getParent() && 
!Add->hasOneUse()1.04k
)
1274
336
    return false;
1275
3.09k
1276
3.09k
  if (!replaceMathCmpWithIntrinsic(Add, Cmp, Intrinsic::uadd_with_overflow))
1277
704
    return false;
1278
2.39k
1279
2.39k
  // Reset callers - do not crash by iterating over a dead instruction.
1280
2.39k
  ModifiedDT = true;
1281
2.39k
  return true;
1282
2.39k
}
1283
1284
bool CodeGenPrepare::combineToUSubWithOverflow(CmpInst *Cmp,
1285
3.60M
                                               bool &ModifiedDT) {
1286
3.60M
  // We are not expecting non-canonical/degenerate code. Just bail out.
1287
3.60M
  Value *A = Cmp->getOperand(0), *B = Cmp->getOperand(1);
1288
3.60M
  if (isa<Constant>(A) && 
isa<Constant>(B)2.07k
)
1289
890
    return false;
1290
3.60M
1291
3.60M
  // Convert (A u> B) to (A u< B) to simplify pattern matching.
1292
3.60M
  ICmpInst::Predicate Pred = Cmp->getPredicate();
1293
3.60M
  if (Pred == ICmpInst::ICMP_UGT) {
1294
127k
    std::swap(A, B);
1295
127k
    Pred = ICmpInst::ICMP_ULT;
1296
127k
  }
1297
3.60M
  // Convert special-case: (A == 0) is the same as (A u< 1).
1298
3.60M
  if (Pred == ICmpInst::ICMP_EQ && 
match(B, m_ZeroInt())2.29M
) {
1299
1.04M
    B = ConstantInt::get(B->getType(), 1);
1300
1.04M
    Pred = ICmpInst::ICMP_ULT;
1301
1.04M
  }
1302
3.60M
  // Convert special-case: (A != 0) is the same as (0 u< A).
1303
3.60M
  if (Pred == ICmpInst::ICMP_NE && 
match(B, m_ZeroInt())137k
) {
1304
112k
    std::swap(A, B);
1305
112k
    Pred = ICmpInst::ICMP_ULT;
1306
112k
  }
1307
3.60M
  if (Pred != ICmpInst::ICMP_ULT)
1308
2.03M
    return false;
1309
1.56M
1310
1.56M
  // Walk the users of a variable operand of a compare looking for a subtract or
1311
1.56M
  // add with that same operand. Also match the 2nd operand of the compare to
1312
1.56M
  // the add/sub, but that may be a negated constant operand of an add.
1313
1.56M
  Value *CmpVariableOperand = isa<Constant>(A) ? 
B185k
:
A1.38M
;
1314
1.56M
  BinaryOperator *Sub = nullptr;
1315
3.91M
  for (User *U : CmpVariableOperand->users()) {
1316
3.91M
    // A - B, A u< B --> usubo(A, B)
1317
3.91M
    if (match(U, m_Sub(m_Specific(A), m_Specific(B)))) {
1318
4.26k
      Sub = cast<BinaryOperator>(U);
1319
4.26k
      break;
1320
4.26k
    }
1321
3.91M
1322
3.91M
    // A + (-C), A u< C (canonicalized form of (sub A, C))
1323
3.91M
    const APInt *CmpC, *AddC;
1324
3.91M
    if (match(U, m_Add(m_Specific(A), m_APInt(AddC))) &&
1325
3.91M
        
match(B, m_APInt(CmpC))68.3k
&&
*AddC == -(*CmpC)62.3k
) {
1326
15.6k
      Sub = cast<BinaryOperator>(U);
1327
15.6k
      break;
1328
15.6k
    }
1329
3.91M
  }
1330
1.56M
  if (!Sub)
1331
1.54M
    return false;
1332
19.8k
1333
19.8k
  if (!TLI->shouldFormOverflowOp(ISD::USUBO,
1334
19.8k
                                 TLI->getValueType(*DL, Sub->getType())))
1335
14.7k
    return false;
1336
5.12k
1337
5.12k
  if (!replaceMathCmpWithIntrinsic(Sub, Cmp, Intrinsic::usub_with_overflow))
1338
4.59k
    return false;
1339
531
1340
531
  // Reset callers - do not crash by iterating over a dead instruction.
1341
531
  ModifiedDT = true;
1342
531
  return true;
1343
531
}
1344
1345
/// Sink the given CmpInst into user blocks to reduce the number of virtual
1346
/// registers that must be created and coalesced. This is a clear win except on
1347
/// targets with multiple condition code registers (PowerPC), where it might
1348
/// lose; some adjustment may be wanted there.
1349
///
1350
/// Return true if any changes are made.
1351
3.64M
static bool sinkCmpExpression(CmpInst *Cmp, const TargetLowering &TLI) {
1352
3.64M
  if (TLI.hasMultipleConditionRegisters())
1353
10.4k
    return false;
1354
3.63M
1355
3.63M
  // Avoid sinking soft-FP comparisons, since this can move them into a loop.
1356
3.63M
  if (TLI.useSoftFloat() && 
isa<FCmpInst>(Cmp)5.93k
)
1357
1.25k
    return false;
1358
3.62M
1359
3.62M
  // Only insert a cmp in each block once.
1360
3.62M
  DenseMap<BasicBlock*, CmpInst*> InsertedCmps;
1361
3.62M
1362
3.62M
  bool MadeChange = false;
1363
3.62M
  for (Value::user_iterator UI = Cmp->user_begin(), E = Cmp->user_end();
1364
7.32M
       UI != E; ) {
1365
3.69M
    Use &TheUse = UI.getUse();
1366
3.69M
    Instruction *User = cast<Instruction>(*UI);
1367
3.69M
1368
3.69M
    // Preincrement use iterator so we don't invalidate it.
1369
3.69M
    ++UI;
1370
3.69M
1371
3.69M
    // Don't bother for PHI nodes.
1372
3.69M
    if (isa<PHINode>(User))
1373
9.97k
      continue;
1374
3.68M
1375
3.68M
    // Figure out which BB this cmp is used in.
1376
3.68M
    BasicBlock *UserBB = User->getParent();
1377
3.68M
    BasicBlock *DefBB = Cmp->getParent();
1378
3.68M
1379
3.68M
    // If this user is in the same block as the cmp, don't change the cmp.
1380
3.68M
    if (UserBB == DefBB) 
continue3.63M
;
1381
51.6k
1382
51.6k
    // If we have already inserted a cmp into this block, use it.
1383
51.6k
    CmpInst *&InsertedCmp = InsertedCmps[UserBB];
1384
51.6k
1385
51.6k
    if (!InsertedCmp) {
1386
51.1k
      BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt();
1387
51.1k
      assert(InsertPt != UserBB->end());
1388
51.1k
      InsertedCmp =
1389
51.1k
          CmpInst::Create(Cmp->getOpcode(), Cmp->getPredicate(),
1390
51.1k
                          Cmp->getOperand(0), Cmp->getOperand(1), "",
1391
51.1k
                          &*InsertPt);
1392
51.1k
      // Propagate the debug info.
1393
51.1k
      InsertedCmp->setDebugLoc(Cmp->getDebugLoc());
1394
51.1k
    }
1395
51.6k
1396
51.6k
    // Replace a use of the cmp with a use of the new cmp.
1397
51.6k
    TheUse = InsertedCmp;
1398
51.6k
    MadeChange = true;
1399
51.6k
    ++NumCmpUses;
1400
51.6k
  }
1401
3.62M
1402
3.62M
  // If we removed all uses, nuke the cmp.
1403
3.62M
  if (Cmp->use_empty()) {
1404
15.4k
    Cmp->eraseFromParent();
1405
15.4k
    MadeChange = true;
1406
15.4k
  }
1407
3.62M
1408
3.62M
  return MadeChange;
1409
3.62M
}
1410
1411
3.64M
bool CodeGenPrepare::optimizeCmp(CmpInst *Cmp, bool &ModifiedDT) {
1412
3.64M
  if (sinkCmpExpression(Cmp, *TLI))
1413
34.0k
    return true;
1414
3.60M
1415
3.60M
  if (combineToUAddWithOverflow(Cmp, ModifiedDT))
1416
2.39k
    return true;
1417
3.60M
1418
3.60M
  if (combineToUSubWithOverflow(Cmp, ModifiedDT))
1419
531
    return true;
1420
3.60M
1421
3.60M
  return false;
1422
3.60M
}
1423
1424
/// Duplicate and sink the given 'and' instruction into user blocks where it is
1425
/// used in a compare to allow isel to generate better code for targets where
1426
/// this operation can be combined.
1427
///
1428
/// Return true if any changes are made.
1429
static bool sinkAndCmp0Expression(Instruction *AndI,
1430
                                  const TargetLowering &TLI,
1431
484k
                                  SetOfInstrs &InsertedInsts) {
1432
484k
  // Double-check that we're not trying to optimize an instruction that was
1433
484k
  // already optimized by some other part of this pass.
1434
484k
  assert(!InsertedInsts.count(AndI) &&
1435
484k
         "Attempting to optimize already optimized and instruction");
1436
484k
  (void) InsertedInsts;
1437
484k
1438
484k
  // Nothing to do for single use in same basic block.
1439
484k
  if (AndI->hasOneUse() &&
1440
484k
      
AndI->getParent() == cast<Instruction>(*AndI->user_begin())->getParent()385k
)
1441
353k
    return false;
1442
131k
1443
131k
  // Try to avoid cases where sinking/duplicating is likely to increase register
1444
131k
  // pressure.
1445
131k
  if (!isa<ConstantInt>(AndI->getOperand(0)) &&
1446
131k
      
!isa<ConstantInt>(AndI->getOperand(1))131k
&&
1447
131k
      
AndI->getOperand(0)->hasOneUse()65.2k
&&
AndI->getOperand(1)->hasOneUse()60.6k
)
1448
58.9k
    return false;
1449
72.7k
1450
76.4k
  
for (auto *U : AndI->users())72.7k
{
1451
76.4k
    Instruction *User = cast<Instruction>(U);
1452
76.4k
1453
76.4k
    // Only sink 'and' feeding icmp with 0.
1454
76.4k
    if (!isa<ICmpInst>(User))
1455
66.8k
      return false;
1456
9.60k
1457
9.60k
    auto *CmpC = dyn_cast<ConstantInt>(User->getOperand(1));
1458
9.60k
    if (!CmpC || 
!CmpC->isZero()5.62k
)
1459
5.11k
      return false;
1460
9.60k
  }
1461
72.7k
1462
72.7k
  
if (853
!TLI.isMaskAndCmp0FoldingBeneficial(*AndI)853
)
1463
206
    return false;
1464
647
1465
647
  LLVM_DEBUG(dbgs() << "found 'and' feeding only icmp 0;\n");
1466
647
  LLVM_DEBUG(AndI->getParent()->dump());
1467
647
1468
647
  // Push the 'and' into the same block as the icmp 0.  There should only be
1469
647
  // one (icmp (and, 0)) in each block, since CSE/GVN should have removed any
1470
647
  // others, so we don't need to keep track of which BBs we insert into.
1471
647
  for (Value::user_iterator UI = AndI->user_begin(), E = AndI->user_end();
1472
2.00k
       UI != E; ) {
1473
1.36k
    Use &TheUse = UI.getUse();
1474
1.36k
    Instruction *User = cast<Instruction>(*UI);
1475
1.36k
1476
1.36k
    // Preincrement use iterator so we don't invalidate it.
1477
1.36k
    ++UI;
1478
1.36k
1479
1.36k
    LLVM_DEBUG(dbgs() << "sinking 'and' use: " << *User << "\n");
1480
1.36k
1481
1.36k
    // Keep the 'and' in the same place if the use is already in the same block.
1482
1.36k
    Instruction *InsertPt =
1483
1.36k
        User->getParent() == AndI->getParent() ? 
AndI309
:
User1.05k
;
1484
1.36k
    Instruction *InsertedAnd =
1485
1.36k
        BinaryOperator::Create(Instruction::And, AndI->getOperand(0),
1486
1.36k
                               AndI->getOperand(1), "", InsertPt);
1487
1.36k
    // Propagate the debug info.
1488
1.36k
    InsertedAnd->setDebugLoc(AndI->getDebugLoc());
1489
1.36k
1490
1.36k
    // Replace a use of the 'and' with a use of the new 'and'.
1491
1.36k
    TheUse = InsertedAnd;
1492
1.36k
    ++NumAndUses;
1493
1.36k
    LLVM_DEBUG(User->getParent()->dump());
1494
1.36k
  }
1495
647
1496
647
  // We removed all uses, nuke the and.
1497
647
  AndI->eraseFromParent();
1498
647
  return true;
1499
647
}
1500
1501
/// Check if the candidates could be combined with a shift instruction, which
1502
/// includes:
1503
/// 1. Truncate instruction
1504
/// 2. And instruction and the imm is a mask of the low bits:
1505
/// imm & (imm+1) == 0
1506
155k
static bool isExtractBitsCandidateUse(Instruction *User) {
1507
155k
  if (!isa<TruncInst>(User)) {
1508
100k
    if (User->getOpcode() != Instruction::And ||
1509
100k
        
!isa<ConstantInt>(User->getOperand(1))13.1k
)
1510
87.6k
      return false;
1511
12.5k
1512
12.5k
    const APInt &Cimm = cast<ConstantInt>(User->getOperand(1))->getValue();
1513
12.5k
1514
12.5k
    if ((Cimm & (Cimm + 1)).getBoolValue())
1515
561
      return false;
1516
67.2k
  }
1517
67.2k
  return true;
1518
67.2k
}
1519
1520
/// Sink both shift and truncate instruction to the use of truncate's BB.
1521
static bool
1522
SinkShiftAndTruncate(BinaryOperator *ShiftI, Instruction *User, ConstantInt *CI,
1523
                     DenseMap<BasicBlock *, BinaryOperator *> &InsertedShifts,
1524
6.56k
                     const TargetLowering &TLI, const DataLayout &DL) {
1525
6.56k
  BasicBlock *UserBB = User->getParent();
1526
6.56k
  DenseMap<BasicBlock *, CastInst *> InsertedTruncs;
1527
6.56k
  TruncInst *TruncI = dyn_cast<TruncInst>(User);
1528
6.56k
  bool MadeChange = false;
1529
6.56k
1530
6.56k
  for (Value::user_iterator TruncUI = TruncI->user_begin(),
1531
6.56k
                            TruncE = TruncI->user_end();
1532
14.8k
       TruncUI != TruncE;) {
1533
8.25k
1534
8.25k
    Use &TruncTheUse = TruncUI.getUse();
1535
8.25k
    Instruction *TruncUser = cast<Instruction>(*TruncUI);
1536
8.25k
    // Preincrement use iterator so we don't invalidate it.
1537
8.25k
1538
8.25k
    ++TruncUI;
1539
8.25k
1540
8.25k
    int ISDOpcode = TLI.InstructionOpcodeToISD(TruncUser->getOpcode());
1541
8.25k
    if (!ISDOpcode)
1542
309
      continue;
1543
7.95k
1544
7.95k
    // If the use is actually a legal node, there will not be an
1545
7.95k
    // implicit truncate.
1546
7.95k
    // FIXME: always querying the result type is just an
1547
7.95k
    // approximation; some nodes' legality is determined by the
1548
7.95k
    // operand or other means. There's no good way to find out though.
1549
7.95k
    if (TLI.isOperationLegalOrCustom(
1550
7.95k
            ISDOpcode, TLI.getValueType(DL, TruncUser->getType(), true)))
1551
145
      continue;
1552
7.80k
1553
7.80k
    // Don't bother for PHI nodes.
1554
7.80k
    if (isa<PHINode>(TruncUser))
1555
0
      continue;
1556
7.80k
1557
7.80k
    BasicBlock *TruncUserBB = TruncUser->getParent();
1558
7.80k
1559
7.80k
    if (UserBB == TruncUserBB)
1560
7.74k
      continue;
1561
59
1562
59
    BinaryOperator *&InsertedShift = InsertedShifts[TruncUserBB];
1563
59
    CastInst *&InsertedTrunc = InsertedTruncs[TruncUserBB];
1564
59
1565
59
    if (!InsertedShift && 
!InsertedTrunc58
) {
1566
58
      BasicBlock::iterator InsertPt = TruncUserBB->getFirstInsertionPt();
1567
58
      assert(InsertPt != TruncUserBB->end());
1568
58
      // Sink the shift
1569
58
      if (ShiftI->getOpcode() == Instruction::AShr)
1570
0
        InsertedShift = BinaryOperator::CreateAShr(ShiftI->getOperand(0), CI,
1571
0
                                                   "", &*InsertPt);
1572
58
      else
1573
58
        InsertedShift = BinaryOperator::CreateLShr(ShiftI->getOperand(0), CI,
1574
58
                                                   "", &*InsertPt);
1575
58
      InsertedShift->setDebugLoc(ShiftI->getDebugLoc());
1576
58
1577
58
      // Sink the trunc
1578
58
      BasicBlock::iterator TruncInsertPt = TruncUserBB->getFirstInsertionPt();
1579
58
      TruncInsertPt++;
1580
58
      assert(TruncInsertPt != TruncUserBB->end());
1581
58
1582
58
      InsertedTrunc = CastInst::Create(TruncI->getOpcode(), InsertedShift,
1583
58
                                       TruncI->getType(), "", &*TruncInsertPt);
1584
58
      InsertedTrunc->setDebugLoc(TruncI->getDebugLoc());
1585
58
1586
58
      MadeChange = true;
1587
58
1588
58
      TruncTheUse = InsertedTrunc;
1589
58
    }
1590
59
  }
1591
6.56k
  return MadeChange;
1592
6.56k
}
1593
1594
/// Sink the shift *right* instruction into user blocks if the uses could
1595
/// potentially be combined with this shift instruction and generate BitExtract
1596
/// instruction. It will only be applied if the architecture supports BitExtract
1597
/// instruction. Here is an example:
1598
/// BB1:
1599
///   %x.extract.shift = lshr i64 %arg1, 32
1600
/// BB2:
1601
///   %x.extract.trunc = trunc i64 %x.extract.shift to i16
1602
/// ==>
1603
///
1604
/// BB2:
1605
///   %x.extract.shift.1 = lshr i64 %arg1, 32
1606
///   %x.extract.trunc = trunc i64 %x.extract.shift.1 to i16
1607
///
1608
/// CodeGen will recognize the pattern in BB2 and generate BitExtract
1609
/// instruction.
1610
/// Return true if any changes are made.
1611
static bool OptimizeExtractBits(BinaryOperator *ShiftI, ConstantInt *CI,
1612
                                const TargetLowering &TLI,
1613
138k
                                const DataLayout &DL) {
1614
138k
  BasicBlock *DefBB = ShiftI->getParent();
1615
138k
1616
138k
  /// Only insert instructions in each block once.
1617
138k
  DenseMap<BasicBlock *, BinaryOperator *> InsertedShifts;
1618
138k
1619
138k
  bool shiftIsLegal = TLI.isTypeLegal(TLI.getValueType(DL, ShiftI->getType()));
1620
138k
1621
138k
  bool MadeChange = false;
1622
138k
  for (Value::user_iterator UI = ShiftI->user_begin(), E = ShiftI->user_end();
1623
303k
       UI != E;) {
1624
165k
    Use &TheUse = UI.getUse();
1625
165k
    Instruction *User = cast<Instruction>(*UI);
1626
165k
    // Preincrement use iterator so we don't invalidate it.
1627
165k
    ++UI;
1628
165k
1629
165k
    // Don't bother for PHI nodes.
1630
165k
    if (isa<PHINode>(User))
1631
9.68k
      continue;
1632
155k
1633
155k
    if (!isExtractBitsCandidateUse(User))
1634
88.1k
      continue;
1635
67.2k
1636
67.2k
    BasicBlock *UserBB = User->getParent();
1637
67.2k
1638
67.2k
    if (UserBB == DefBB) {
1639
65.5k
      // If the shift and truncate instruction are in the same BB. The use of
1640
65.5k
      // the truncate(TruncUse) may still introduce another truncate if not
1641
65.5k
      // legal. In this case, we would like to sink both shift and truncate
1642
65.5k
      // instruction to the BB of TruncUse.
1643
65.5k
      // for example:
1644
65.5k
      // BB1:
1645
65.5k
      // i64 shift.result = lshr i64 opnd, imm
1646
65.5k
      // trunc.result = trunc shift.result to i16
1647
65.5k
      //
1648
65.5k
      // BB2:
1649
65.5k
      //   ----> We will have an implicit truncate here if the architecture does
1650
65.5k
      //   not have i16 compare.
1651
65.5k
      // cmp i16 trunc.result, opnd2
1652
65.5k
      //
1653
65.5k
      if (isa<TruncInst>(User) && 
shiftIsLegal53.7k
1654
65.5k
          // If the type of the truncate is legal, no truncate will be
1655
65.5k
          // introduced in other basic blocks.
1656
65.5k
          &&
1657
65.5k
          
(!TLI.isTypeLegal(TLI.getValueType(DL, User->getType())))52.6k
)
1658
6.56k
        MadeChange =
1659
6.56k
            SinkShiftAndTruncate(ShiftI, User, CI, InsertedShifts, TLI, DL);
1660
65.5k
1661
65.5k
      continue;
1662
65.5k
    }
1663
1.63k
    // If we have already inserted a shift into this block, use it.
1664
1.63k
    BinaryOperator *&InsertedShift = InsertedShifts[UserBB];
1665
1.63k
1666
1.63k
    if (!InsertedShift) {
1667
1.63k
      BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt();
1668
1.63k
      assert(InsertPt != UserBB->end());
1669
1.63k
1670
1.63k
      if (ShiftI->getOpcode() == Instruction::AShr)
1671
30
        InsertedShift = BinaryOperator::CreateAShr(ShiftI->getOperand(0), CI,
1672
30
                                                   "", &*InsertPt);
1673
1.60k
      else
1674
1.60k
        InsertedShift = BinaryOperator::CreateLShr(ShiftI->getOperand(0), CI,
1675
1.60k
                                                   "", &*InsertPt);
1676
1.63k
      InsertedShift->setDebugLoc(ShiftI->getDebugLoc());
1677
1.63k
1678
1.63k
      MadeChange = true;
1679
1.63k
    }
1680
1.63k
1681
1.63k
    // Replace a use of the shift with a use of the new shift.
1682
1.63k
    TheUse = InsertedShift;
1683
1.63k
  }
1684
138k
1685
138k
  // If we removed all uses, nuke the shift.
1686
138k
  if (ShiftI->use_empty()) {
1687
74
    salvageDebugInfo(*ShiftI);
1688
74
    ShiftI->eraseFromParent();
1689
74
  }
1690
138k
1691
138k
  return MadeChange;
1692
138k
}
1693
1694
/// If counting leading or trailing zeros is an expensive operation and a zero
1695
/// input is defined, add a check for zero to avoid calling the intrinsic.
1696
///
1697
/// We want to transform:
1698
///     %z = call i64 @llvm.cttz.i64(i64 %A, i1 false)
1699
///
1700
/// into:
1701
///   entry:
1702
///     %cmpz = icmp eq i64 %A, 0
1703
///     br i1 %cmpz, label %cond.end, label %cond.false
1704
///   cond.false:
1705
///     %z = call i64 @llvm.cttz.i64(i64 %A, i1 true)
1706
///     br label %cond.end
1707
///   cond.end:
1708
///     %ctz = phi i64 [ 64, %entry ], [ %z, %cond.false ]
1709
///
1710
/// If the transform is performed, return true and set ModifiedDT to true.
1711
static bool despeculateCountZeros(IntrinsicInst *CountZeros,
1712
                                  const TargetLowering *TLI,
1713
                                  const DataLayout *DL,
1714
8.47k
                                  bool &ModifiedDT) {
1715
8.47k
  if (!TLI || !DL)
1716
0
    return false;
1717
8.47k
1718
8.47k
  // If a zero input is undefined, it doesn't make sense to despeculate that.
1719
8.47k
  if (match(CountZeros->getOperand(1), m_One()))
1720
5.79k
    return false;
1721
2.67k
1722
2.67k
  // If it's cheap to speculate, there's nothing to do.
1723
2.67k
  auto IntrinsicID = CountZeros->getIntrinsicID();
1724
2.67k
  if ((IntrinsicID == Intrinsic::cttz && 
TLI->isCheapToSpeculateCttz()857
) ||
1725
2.67k
      
(2.06k
IntrinsicID == Intrinsic::ctlz2.06k
&&
TLI->isCheapToSpeculateCtlz()1.82k
))
1726
2.09k
    return false;
1727
588
1728
588
  // Only handle legal scalar cases. Anything else requires too much work.
1729
588
  Type *Ty = CountZeros->getType();
1730
588
  unsigned SizeInBits = Ty->getPrimitiveSizeInBits();
1731
588
  if (Ty->isVectorTy() || 
SizeInBits > DL->getLargestLegalIntTypeSizeInBits()120
)
1732
487
    return false;
1733
101
1734
101
  // The intrinsic will be sunk behind a compare against zero and branch.
1735
101
  BasicBlock *StartBlock = CountZeros->getParent();
1736
101
  BasicBlock *CallBlock = StartBlock->splitBasicBlock(CountZeros, "cond.false");
1737
101
1738
101
  // Create another block after the count zero intrinsic. A PHI will be added
1739
101
  // in this block to select the result of the intrinsic or the bit-width
1740
101
  // constant if the input to the intrinsic is zero.
1741
101
  BasicBlock::iterator SplitPt = ++(BasicBlock::iterator(CountZeros));
1742
101
  BasicBlock *EndBlock = CallBlock->splitBasicBlock(SplitPt, "cond.end");
1743
101
1744
101
  // Set up a builder to create a compare, conditional branch, and PHI.
1745
101
  IRBuilder<> Builder(CountZeros->getContext());
1746
101
  Builder.SetInsertPoint(StartBlock->getTerminator());
1747
101
  Builder.SetCurrentDebugLocation(CountZeros->getDebugLoc());
1748
101
1749
101
  // Replace the unconditional branch that was created by the first split with
1750
101
  // a compare against zero and a conditional branch.
1751
101
  Value *Zero = Constant::getNullValue(Ty);
1752
101
  Value *Cmp = Builder.CreateICmpEQ(CountZeros->getOperand(0), Zero, "cmpz");
1753
101
  Builder.CreateCondBr(Cmp, EndBlock, CallBlock);
1754
101
  StartBlock->getTerminator()->eraseFromParent();
1755
101
1756
101
  // Create a PHI in the end block to select either the output of the intrinsic
1757
101
  // or the bit width of the operand.
1758
101
  Builder.SetInsertPoint(&EndBlock->front());
1759
101
  PHINode *PN = Builder.CreatePHI(Ty, 2, "ctz");
1760
101
  CountZeros->replaceAllUsesWith(PN);
1761
101
  Value *BitWidth = Builder.getInt(APInt(SizeInBits, SizeInBits));
1762
101
  PN->addIncoming(BitWidth, StartBlock);
1763
101
  PN->addIncoming(CountZeros, CallBlock);
1764
101
1765
101
  // We are explicitly handling the zero case, so we can set the intrinsic's
1766
101
  // undefined zero argument to 'true'. This will also prevent reprocessing the
1767
101
  // intrinsic; we only despeculate when a zero input is defined.
1768
101
  CountZeros->setArgOperand(1, Builder.getTrue());
1769
101
  ModifiedDT = true;
1770
101
  return true;
1771
101
}
1772
1773
4.03M
bool CodeGenPrepare::optimizeCallInst(CallInst *CI, bool &ModifiedDT) {
1774
4.03M
  BasicBlock *BB = CI->getParent();
1775
4.03M
1776
4.03M
  // Lower inline assembly if we can.
1777
4.03M
  // If we found an inline asm expession, and if the target knows how to
1778
4.03M
  // lower it to normal LLVM code, do so now.
1779
4.03M
  if (TLI && 
isa<InlineAsm>(CI->getCalledValue())4.03M
) {
1780
27.0k
    if (TLI->ExpandInlineAsm(CI)) {
1781
27
      // Avoid invalidating the iterator.
1782
27
      CurInstIterator = BB->begin();
1783
27
      // Avoid processing instructions out of order, which could cause
1784
27
      // reuse before a value is defined.
1785
27
      SunkAddrs.clear();
1786
27
      return true;
1787
27
    }
1788
26.9k
    // Sink address computing for memory operands into the block.
1789
26.9k
    if (optimizeInlineAsmInst(CI))
1790
5
      return true;
1791
4.03M
  }
1792
4.03M
1793
4.03M
  // Align the pointer arguments to this call if the target thinks it's a good
1794
4.03M
  // idea
1795
4.03M
  unsigned MinSize, PrefAlign;
1796
4.03M
  if (TLI && 
TLI->shouldAlignPointerArgs(CI, MinSize, PrefAlign)4.03M
) {
1797
5.42k
    for (auto &Arg : CI->arg_operands()) {
1798
5.42k
      // We want to align both objects whose address is used directly and
1799
5.42k
      // objects whose address is used in casts and GEPs, though it only makes
1800
5.42k
      // sense for GEPs if the offset is a multiple of the desired alignment and
1801
5.42k
      // if size - offset meets the size threshold.
1802
5.42k
      if (!Arg->getType()->isPointerTy())
1803
3.04k
        continue;
1804
2.37k
      APInt Offset(DL->getIndexSizeInBits(
1805
2.37k
                       cast<PointerType>(Arg->getType())->getAddressSpace()),
1806
2.37k
                   0);
1807
2.37k
      Value *Val = Arg->stripAndAccumulateInBoundsConstantOffsets(*DL, Offset);
1808
2.37k
      uint64_t Offset2 = Offset.getLimitedValue();
1809
2.37k
      if ((Offset2 & (PrefAlign-1)) != 0)
1810
64
        continue;
1811
2.31k
      AllocaInst *AI;
1812
2.31k
      if ((AI = dyn_cast<AllocaInst>(Val)) && 
AI->getAlignment() < PrefAlign560
&&
1813
2.31k
          
DL->getTypeAllocSize(AI->getAllocatedType()) >= MinSize + Offset2321
)
1814
145
        AI->setAlignment(PrefAlign);
1815
2.31k
      // Global variables can only be aligned if they are defined in this
1816
2.31k
      // object (i.e. they are uniquely initialized in this object), and
1817
2.31k
      // over-aligning global variables that have an explicit section is
1818
2.31k
      // forbidden.
1819
2.31k
      GlobalVariable *GV;
1820
2.31k
      if ((GV = dyn_cast<GlobalVariable>(Val)) && 
GV->canIncreaseAlignment()269
&&
1821
2.31k
          
GV->getPointerAlignment(*DL) < PrefAlign127
&&
1822
2.31k
          DL->getTypeAllocSize(GV->getValueType()) >=
1823
112
              MinSize + Offset2)
1824
51
        GV->setAlignment(PrefAlign);
1825
2.31k
    }
1826
1.35k
    // If this is a memcpy (or similar) then we may be able to improve the
1827
1.35k
    // alignment
1828
1.35k
    if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) {
1829
1.35k
      unsigned DestAlign = getKnownAlignment(MI->getDest(), *DL);
1830
1.35k
      if (DestAlign > MI->getDestAlignment())
1831
566
        MI->setDestAlignment(DestAlign);
1832
1.35k
      if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
1833
1.02k
        unsigned SrcAlign = getKnownAlignment(MTI->getSource(), *DL);
1834
1.02k
        if (SrcAlign > MTI->getSourceAlignment())
1835
461
          MTI->setSourceAlignment(SrcAlign);
1836
1.02k
      }
1837
1.35k
    }
1838
1.35k
  }
1839
4.03M
1840
4.03M
  // If we have a cold call site, try to sink addressing computation into the
1841
4.03M
  // cold block.  This interacts with our handling for loads and stores to
1842
4.03M
  // ensure that we can fold all uses of a potential addressing computation
1843
4.03M
  // into their uses.  TODO: generalize this to work over profiling data
1844
4.03M
  if (!OptSize && 
CI->hasFnAttr(Attribute::Cold)4.02M
)
1845
679
    for (auto &Arg : CI->arg_operands()) {
1846
238
      if (!Arg->getType()->isPointerTy())
1847
6
        continue;
1848
232
      unsigned AS = Arg->getType()->getPointerAddressSpace();
1849
232
      return optimizeMemoryInst(CI, Arg, Arg->getType(), AS);
1850
232
    }
1851
4.03M
1852
4.03M
  IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
1853
4.03M
  if (II) {
1854
940k
    switch (II->getIntrinsicID()) {
1855
940k
    
default: break883k
;
1856
940k
    case Intrinsic::experimental_widenable_condition: {
1857
8
      // Give up on future widening oppurtunties so that we can fold away dead
1858
8
      // paths and merge blocks before going into block-local instruction
1859
8
      // selection.   
1860
8
      if (II->use_empty()) {
1861
4
        II->eraseFromParent();
1862
4
        return true;
1863
4
      }
1864
4
      Constant *RetVal = ConstantInt::getTrue(II->getContext());
1865
4
      resetIteratorIfInvalidatedWhileCalling(BB, [&]() {
1866
4
        replaceAndRecursivelySimplify(CI, RetVal, TLInfo, nullptr);
1867
4
      });
1868
4
      return true;
1869
4
    }
1870
3.40k
    case Intrinsic::objectsize: {
1871
3.40k
      // Lower all uses of llvm.objectsize.*
1872
3.40k
      Value *RetVal =
1873
3.40k
          lowerObjectSizeCall(II, *DL, TLInfo, /*MustSucceed=*/true);
1874
3.40k
1875
3.40k
      resetIteratorIfInvalidatedWhileCalling(BB, [&]() {
1876
3.40k
        replaceAndRecursivelySimplify(CI, RetVal, TLInfo, nullptr);
1877
3.40k
      });
1878
3.40k
      return true;
1879
4
    }
1880
19
    case Intrinsic::is_constant: {
1881
19
      // If is_constant hasn't folded away yet, lower it to false now.
1882
19
      Constant *RetVal = ConstantInt::get(II->getType(), 0);
1883
19
      resetIteratorIfInvalidatedWhileCalling(BB, [&]() {
1884
19
        replaceAndRecursivelySimplify(CI, RetVal, TLInfo, nullptr);
1885
19
      });
1886
19
      return true;
1887
4
    }
1888
44.5k
    case Intrinsic::aarch64_stlxr:
1889
44.5k
    case Intrinsic::aarch64_stxr: {
1890
44.5k
      ZExtInst *ExtVal = dyn_cast<ZExtInst>(CI->getArgOperand(0));
1891
44.5k
      if (!ExtVal || 
!ExtVal->hasOneUse()8.87k
||
1892
44.5k
          
ExtVal->getParent() == CI->getParent()8.87k
)
1893
44.5k
        return false;
1894
1
      // Sink a zext feeding stlxr/stxr before it, so it can be folded into it.
1895
1
      ExtVal->moveBefore(CI);
1896
1
      // Mark this instruction as "inserted by CGP", so that other
1897
1
      // optimizations don't touch it.
1898
1
      InsertedInsts.insert(ExtVal);
1899
1
      return true;
1900
1
    }
1901
1
1902
5
    case Intrinsic::launder_invariant_group:
1903
5
    case Intrinsic::strip_invariant_group: {
1904
5
      Value *ArgVal = II->getArgOperand(0);
1905
5
      auto it = LargeOffsetGEPMap.find(II);
1906
5
      if (it != LargeOffsetGEPMap.end()) {
1907
1
          // Merge entries in LargeOffsetGEPMap to reflect the RAUW.
1908
1
          // Make sure not to have to deal with iterator invalidation
1909
1
          // after possibly adding ArgVal to LargeOffsetGEPMap.
1910
1
          auto GEPs = std::move(it->second);
1911
1
          LargeOffsetGEPMap[ArgVal].append(GEPs.begin(), GEPs.end());
1912
1
          LargeOffsetGEPMap.erase(II);
1913
1
      }
1914
5
1915
5
      II->replaceAllUsesWith(ArgVal);
1916
5
      II->eraseFromParent();
1917
5
      return true;
1918
5
    }
1919
8.47k
    case Intrinsic::cttz:
1920
8.47k
    case Intrinsic::ctlz:
1921
8.47k
      // If counting zeros is expensive, try to avoid it.
1922
8.47k
      return despeculateCountZeros(II, TLI, DL, ModifiedDT);
1923
883k
    }
1924
883k
1925
883k
    if (TLI) {
1926
883k
      SmallVector<Value*, 2> PtrOps;
1927
883k
      Type *AccessTy;
1928
883k
      if (TLI->getAddrModeArguments(II, PtrOps, AccessTy))
1929
660
        
while (338
!PtrOps.empty()) {
1930
338
          Value *PtrVal = PtrOps.pop_back_val();
1931
338
          unsigned AS = PtrVal->getType()->getPointerAddressSpace();
1932
338
          if (optimizeMemoryInst(II, PtrVal, AccessTy, AS))
1933
16
            return true;
1934
338
        }
1935
883k
    }
1936
883k
  }
1937
4.03M
1938
4.03M
  // From here on out we're working with named functions.
1939
4.03M
  
if (3.97M
!CI->getCalledFunction()3.97M
)
return false149k
;
1940
3.82M
1941
3.82M
  // Lower all default uses of _chk calls.  This is very similar
1942
3.82M
  // to what InstCombineCalls does, but here we are only lowering calls
1943
3.82M
  // to fortified library functions (e.g. __memcpy_chk) that have the default
1944
3.82M
  // "don't know" as the objectsize.  Anything else should be left alone.
1945
3.82M
  FortifiedLibCallSimplifier Simplifier(TLInfo, true);
1946
3.82M
  if (Value *V = Simplifier.optimizeCall(CI)) {
1947
3.50k
    CI->replaceAllUsesWith(V);
1948
3.50k
    CI->eraseFromParent();
1949
3.50k
    return true;
1950
3.50k
  }
1951
3.82M
1952
3.82M
  return false;
1953
3.82M
}
1954
1955
/// Look for opportunities to duplicate return instructions to the predecessor
1956
/// to enable tail call optimizations. The case it is currently looking for is:
1957
/// @code
1958
/// bb0:
1959
///   %tmp0 = tail call i32 @f0()
1960
///   br label %return
1961
/// bb1:
1962
///   %tmp1 = tail call i32 @f1()
1963
///   br label %return
1964
/// bb2:
1965
///   %tmp2 = tail call i32 @f2()
1966
///   br label %return
1967
/// return:
1968
///   %retval = phi i32 [ %tmp0, %bb0 ], [ %tmp1, %bb1 ], [ %tmp2, %bb2 ]
1969
///   ret i32 %retval
1970
/// @endcode
1971
///
1972
/// =>
1973
///
1974
/// @code
1975
/// bb0:
1976
///   %tmp0 = tail call i32 @f0()
1977
///   ret i32 %tmp0
1978
/// bb1:
1979
///   %tmp1 = tail call i32 @f1()
1980
///   ret i32 %tmp1
1981
/// bb2:
1982
///   %tmp2 = tail call i32 @f2()
1983
///   ret i32 %tmp2
1984
/// @endcode
1985
6.33M
bool CodeGenPrepare::dupRetToEnableTailCallOpts(BasicBlock *BB, bool &ModifiedDT) {
1986
6.33M
  if (!TLI)
1987
193
    return false;
1988
6.33M
1989
6.33M
  ReturnInst *RetI = dyn_cast<ReturnInst>(BB->getTerminator());
1990
6.33M
  if (!RetI)
1991
5.14M
    return false;
1992
1.19M
1993
1.19M
  PHINode *PN = nullptr;
1994
1.19M
  BitCastInst *BCI = nullptr;
1995
1.19M
  Value *V = RetI->getReturnValue();
1996
1.19M
  if (V) {
1997
969k
    BCI = dyn_cast<BitCastInst>(V);
1998
969k
    if (BCI)
1999
16.5k
      V = BCI->getOperand(0);
2000
969k
2001
969k
    PN = dyn_cast<PHINode>(V);
2002
969k
    if (!PN)
2003
860k
      return false;
2004
330k
  }
2005
330k
2006
330k
  if (PN && 
PN->getParent() != BB109k
)
2007
4.65k
    return false;
2008
325k
2009
325k
  // Make sure there are no instructions between the PHI and return, or that the
2010
325k
  // return is the first instruction in the block.
2011
325k
  if (PN) {
2012
104k
    BasicBlock::iterator BI = BB->begin();
2013
104k
    // Skip over debug and the bitcast.
2014
105k
    do { ++BI; } while (isa<DbgInfoIntrinsic>(BI) || 
&*BI == BCI105k
);
2015
104k
    if (&*BI != RetI)
2016
23.5k
      return false;
2017
220k
  } else {
2018
220k
    BasicBlock::iterator BI = BB->begin();
2019
224k
    while (isa<DbgInfoIntrinsic>(BI)) 
++BI4.07k
;
2020
220k
    if (&*BI != RetI)
2021
157k
      return false;
2022
144k
  }
2023
144k
2024
144k
  /// Only dup the ReturnInst if the CallInst is likely to be emitted as a tail
2025
144k
  /// call.
2026
144k
  const Function *F = BB->getParent();
2027
144k
  SmallVector<CallInst*, 4> TailCalls;
2028
144k
  if (PN) {
2029
451k
    for (unsigned I = 0, E = PN->getNumIncomingValues(); I != E; 
++I369k
) {
2030
369k
      // Look through bitcasts.
2031
369k
      Value *IncomingVal = PN->getIncomingValue(I)->stripPointerCasts();
2032
369k
      CallInst *CI = dyn_cast<CallInst>(IncomingVal);
2033
369k
      // Make sure the phi value is indeed produced by the tail call.
2034
369k
      if (CI && 
CI->hasOneUse()119k
&&
CI->getParent() == PN->getIncomingBlock(I)104k
&&
2035
369k
          
TLI->mayBeEmittedAsTailCall(CI)104k
&&
2036
369k
          
attributesPermitTailCall(F, CI, RetI, *TLI)103k
)
2037
103k
        TailCalls.push_back(CI);
2038
369k
    }
2039
81.4k
  } else {
2040
62.7k
    SmallPtrSet<BasicBlock*, 4> VisitedBBs;
2041
201k
    for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; 
++PI138k
) {
2042
138k
      if (!VisitedBBs.insert(*PI).second)
2043
384
        continue;
2044
138k
2045
138k
      BasicBlock::InstListType &InstList = (*PI)->getInstList();
2046
138k
      BasicBlock::InstListType::reverse_iterator RI = InstList.rbegin();
2047
138k
      BasicBlock::InstListType::reverse_iterator RE = InstList.rend();
2048
138k
      do { ++RI; } while (RI != RE && 
isa<DbgInfoIntrinsic>(&*RI)136k
);
2049
138k
      if (RI == RE)
2050
1.65k
        continue;
2051
136k
2052
136k
      CallInst *CI = dyn_cast<CallInst>(&*RI);
2053
136k
      if (CI && 
CI->use_empty()20.1k
&&
TLI->mayBeEmittedAsTailCall(CI)18.8k
&&
2054
136k
          
attributesPermitTailCall(F, CI, RetI, *TLI)14.2k
)
2055
14.1k
        TailCalls.push_back(CI);
2056
136k
    }
2057
62.7k
  }
2058
144k
2059
144k
  bool Changed = false;
2060
261k
  for (unsigned i = 0, e = TailCalls.size(); i != e; 
++i117k
) {
2061
117k
    CallInst *CI = TailCalls[i];
2062
117k
    CallSite CS(CI);
2063
117k
2064
117k
    // Make sure the call instruction is followed by an unconditional branch to
2065
117k
    // the return block.
2066
117k
    BasicBlock *CallBB = CI->getParent();
2067
117k
    BranchInst *BI = dyn_cast<BranchInst>(CallBB->getTerminator());
2068
117k
    if (!BI || 
!BI->isUnconditional()117k
||
BI->getSuccessor(0) != BB117k
)
2069
153
      continue;
2070
117k
2071
117k
    // Duplicate the return into CallBB.
2072
117k
    (void)FoldReturnIntoUncondBranch(RetI, BB, CallBB);
2073
117k
    ModifiedDT = Changed = true;
2074
117k
    ++NumRetsDup;
2075
117k
  }
2076
144k
2077
144k
  // If we eliminated all predecessors of the block, delete the block now.
2078
144k
  if (Changed && 
!BB->hasAddressTaken()21.4k
&&
pred_begin(BB) == pred_end(BB)21.4k
)
2079
5.99k
    BB->eraseFromParent();
2080
144k
2081
144k
  return Changed;
2082
144k
}
2083
2084
//===----------------------------------------------------------------------===//
2085
// Memory Optimization
2086
//===----------------------------------------------------------------------===//
2087
2088
namespace {
2089
2090
/// This is an extended version of TargetLowering::AddrMode
2091
/// which holds actual Value*'s for register values.
2092
struct ExtAddrMode : public TargetLowering::AddrMode {
2093
  Value *BaseReg = nullptr;
2094
  Value *ScaledReg = nullptr;
2095
  Value *OriginalValue = nullptr;
2096
  bool InBounds = true;
2097
2098
  enum FieldName {
2099
    NoField        = 0x00,
2100
    BaseRegField   = 0x01,
2101
    BaseGVField    = 0x02,
2102
    BaseOffsField  = 0x04,
2103
    ScaledRegField = 0x08,
2104
    ScaleField     = 0x10,
2105
    MultipleFields = 0xff
2106
  };
2107
2108
2109
8.27M
  ExtAddrMode() = default;
2110
2111
  void print(raw_ostream &OS) const;
2112
  void dump() const;
2113
2114
106k
  FieldName compare(const ExtAddrMode &other) {
2115
106k
    // First check that the types are the same on each field, as differing types
2116
106k
    // is something we can't cope with later on.
2117
106k
    if (BaseReg && 
other.BaseReg105k
&&
2118
106k
        
BaseReg->getType() != other.BaseReg->getType()105k
)
2119
19.8k
      return MultipleFields;
2120
86.6k
    if (BaseGV && 
other.BaseGV140
&&
2121
86.6k
        
BaseGV->getType() != other.BaseGV->getType()16
)
2122
0
      return MultipleFields;
2123
86.6k
    if (ScaledReg && 
other.ScaledReg3.48k
&&
2124
86.6k
        
ScaledReg->getType() != other.ScaledReg->getType()1.24k
)
2125
0
      return MultipleFields;
2126
86.6k
2127
86.6k
    // Conservatively reject 'inbounds' mismatches.
2128
86.6k
    if (InBounds != other.InBounds)
2129
28.8k
      return MultipleFields;
2130
57.7k
2131
57.7k
    // Check each field to see if it differs.
2132
57.7k
    unsigned Result = NoField;
2133
57.7k
    if (BaseReg != other.BaseReg)
2134
49.9k
      Result |= BaseRegField;
2135
57.7k
    if (BaseGV != other.BaseGV)
2136
171
      Result |= BaseGVField;
2137
57.7k
    if (BaseOffs != other.BaseOffs)
2138
34.1k
      Result |= BaseOffsField;
2139
57.7k
    if (ScaledReg != other.ScaledReg)
2140
11.3k
      Result |= ScaledRegField;
2141
57.7k
    // Don't count 0 as being a different scale, because that actually means
2142
57.7k
    // unscaled (which will already be counted by having no ScaledReg).
2143
57.7k
    if (Scale && 
other.Scale2.78k
&&
Scale != other.Scale1.20k
)
2144
69
      Result |= ScaleField;
2145
57.7k
2146
57.7k
    if (countPopulation(Result) > 1)
2147
30.8k
      return MultipleFields;
2148
26.8k
    else
2149
26.8k
      return static_cast<FieldName>(Result);
2150
57.7k
  }
2151
2152
  // An AddrMode is trivial if it involves no calculation i.e. it is just a base
2153
  // with no offset.
2154
7.77M
  bool isTrivial() {
2155
7.77M
    // An AddrMode is (BaseGV + BaseReg + BaseOffs + ScaleReg * Scale) so it is
2156
7.77M
    // trivial if at most one of these terms is nonzero, except that BaseGV and
2157
7.77M
    // BaseReg both being zero actually means a null pointer value, which we
2158
7.77M
    // consider to be 'non-zero' here.
2159
7.77M
    return !BaseOffs && 
!Scale2.27M
&&
!(1.86M
BaseGV1.86M
&&
BaseReg17.3k
);
2160
7.77M
  }
2161
2162
12.4k
  Value *GetFieldAsValue(FieldName Field, Type *IntPtrTy) {
2163
12.4k
    switch (Field) {
2164
12.4k
    default:
2165
0
      return nullptr;
2166
12.4k
    case BaseRegField:
2167
7.05k
      return BaseReg;
2168
12.4k
    case BaseGVField:
2169
0
      return BaseGV;
2170
12.4k
    case ScaledRegField:
2171
1.02k
      return ScaledReg;
2172
12.4k
    case BaseOffsField:
2173
4.35k
      return ConstantInt::get(IntPtrTy, BaseOffs);
2174
12.4k
    }
2175
12.4k
  }
2176
2177
  void SetCombinedField(FieldName Field, Value *V,
2178
875
                        const SmallVectorImpl<ExtAddrMode> &AddrModes) {
2179
875
    switch (Field) {
2180
875
    default:
2181
0
      llvm_unreachable("Unhandled fields are expected to be rejected earlier");
2182
875
      
break0
;
2183
875
    case ExtAddrMode::BaseRegField:
2184
139
      BaseReg = V;
2185
139
      break;
2186
875
    case ExtAddrMode::BaseGVField:
2187
0
      // A combined BaseGV is an Instruction, not a GlobalValue, so it goes
2188
0
      // in the BaseReg field.
2189
0
      assert(BaseReg == nullptr);
2190
0
      BaseReg = V;
2191
0
      BaseGV = nullptr;
2192
0
      break;
2193
875
    case ExtAddrMode::ScaledRegField:
2194
37
      ScaledReg = V;
2195
37
      // If we have a mix of scaled and unscaled addrmodes then we want scale
2196
37
      // to be the scale and not zero.
2197
37
      if (!Scale)
2198
19
        for (const ExtAddrMode &AM : AddrModes)
2199
38
          if (AM.Scale) {
2200
19
            Scale = AM.Scale;
2201
19
            break;
2202
19
          }
2203
37
      break;
2204
875
    case ExtAddrMode::BaseOffsField:
2205
699
      // The offset is no longer a constant, so it goes in ScaledReg with a
2206
699
      // scale of 1.
2207
699
      assert(ScaledReg == nullptr);
2208
699
      ScaledReg = V;
2209
699
      Scale = 1;
2210
699
      BaseOffs = 0;
2211
699
      break;
2212
875
    }
2213
875
  }
2214
};
2215
2216
} // end anonymous namespace
2217
2218
#ifndef NDEBUG
2219
static inline raw_ostream &operator<<(raw_ostream &OS, const ExtAddrMode &AM) {
2220
  AM.print(OS);
2221
  return OS;
2222
}
2223
#endif
2224
2225
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2226
void ExtAddrMode::print(raw_ostream &OS) const {
2227
  bool NeedPlus = false;
2228
  OS << "[";
2229
  if (InBounds)
2230
    OS << "inbounds ";
2231
  if (BaseGV) {
2232
    OS << (NeedPlus ? " + " : "")
2233
       << "GV:";
2234
    BaseGV->printAsOperand(OS, /*PrintType=*/false);
2235
    NeedPlus = true;
2236
  }
2237
2238
  if (BaseOffs) {
2239
    OS << (NeedPlus ? " + " : "")
2240
       << BaseOffs;
2241
    NeedPlus = true;
2242
  }
2243
2244
  if (BaseReg) {
2245
    OS << (NeedPlus ? " + " : "")
2246
       << "Base:";
2247
    BaseReg->printAsOperand(OS, /*PrintType=*/false);
2248
    NeedPlus = true;
2249
  }
2250
  if (Scale) {
2251
    OS << (NeedPlus ? " + " : "")
2252
       << Scale << "*";
2253
    ScaledReg->printAsOperand(OS, /*PrintType=*/false);
2254
  }
2255
2256
  OS << ']';
2257
}
2258
2259
LLVM_DUMP_METHOD void ExtAddrMode::dump() const {
2260
  print(dbgs());
2261
  dbgs() << '\n';
2262
}
2263
#endif
2264
2265
namespace {
2266
2267
/// This class provides transaction based operation on the IR.
2268
/// Every change made through this class is recorded in the internal state and
2269
/// can be undone (rollback) until commit is called.
2270
class TypePromotionTransaction {
2271
  /// This represents the common interface of the individual transaction.
2272
  /// Each class implements the logic for doing one specific modification on
2273
  /// the IR via the TypePromotionTransaction.
2274
  class TypePromotionAction {
2275
  protected:
2276
    /// The Instruction modified.
2277
    Instruction *Inst;
2278
2279
  public:
2280
    /// Constructor of the action.
2281
    /// The constructor performs the related action on the IR.
2282
1.02M
    TypePromotionAction(Instruction *Inst) : Inst(Inst) {}
2283
2284
1.02M
    virtual ~TypePromotionAction() = default;
2285
2286
    /// Undo the modification done by this action.
2287
    /// When this method is called, the IR must be in the same state as it was
2288
    /// before this action was applied.
2289
    /// \pre Undoing the action works if and only if the IR is in the exact same
2290
    /// state as it was directly after this action was applied.
2291
    virtual void undo() = 0;
2292
2293
    /// Advocate every change made by this action.
2294
    /// When the results on the IR of the action are to be kept, it is important
2295
    /// to call this function, otherwise hidden information may be kept forever.
2296
169k
    virtual void commit() {
2297
169k
      // Nothing to be done, this action is not doing anything.
2298
169k
    }
2299
  };
2300
2301
  /// Utility to remember the position of an instruction.
2302
  class InsertionHandler {
2303
    /// Position of an instruction.
2304
    /// Either an instruction:
2305
    /// - Is the first in a basic block: BB is used.
2306
    /// - Has a previous instruction: PrevInst is used.
2307
    union {
2308
      Instruction *PrevInst;
2309
      BasicBlock *BB;
2310
    } Point;
2311
2312
    /// Remember whether or not the instruction had a previous instruction.
2313
    bool HasPrevInstruction;
2314
2315
  public:
2316
    /// Record the position of \p Inst.
2317
200k
    InsertionHandler(Instruction *Inst) {
2318
200k
      BasicBlock::iterator It = Inst->getIterator();
2319
200k
      HasPrevInstruction = (It != (Inst->getParent()->begin()));
2320
200k
      if (HasPrevInstruction)
2321
193k
        Point.PrevInst = &*--It;
2322
7.41k
      else
2323
7.41k
        Point.BB = Inst->getParent();
2324
200k
    }
2325
2326
    /// Insert \p Inst at the recorded position.
2327
167k
    void insert(Instruction *Inst) {
2328
167k
      if (HasPrevInstruction) {
2329
160k
        if (Inst->getParent())
2330
148k
          Inst->removeFromParent();
2331
160k
        Inst->insertAfter(Point.PrevInst);
2332
160k
      } else {
2333
6.78k
        Instruction *Position = &*Point.BB->getFirstInsertionPt();
2334
6.78k
        if (Inst->getParent())
2335
6.42k
          Inst->moveBefore(Position);
2336
361
        else
2337
361
          Inst->insertBefore(Position);
2338
6.78k
      }
2339
167k
    }
2340
  };
2341
2342
  /// Move an instruction before another.
2343
  class InstructionMoveBefore : public TypePromotionAction {
2344
    /// Original position of the instruction.
2345
    InsertionHandler Position;
2346
2347
  public:
2348
    /// Move \p Inst before \p Before.
2349
    InstructionMoveBefore(Instruction *Inst, Instruction *Before)
2350
186k
        : TypePromotionAction(Inst), Position(Inst) {
2351
186k
      LLVM_DEBUG(dbgs() << "Do: move: " << *Inst << "\nbefore: " << *Before
2352
186k
                        << "\n");
2353
186k
      Inst->moveBefore(Before);
2354
186k
    }
2355
2356
    /// Move the instruction back to its original position.
2357
154k
    void undo() override {
2358
154k
      LLVM_DEBUG(dbgs() << "Undo: moveBefore: " << *Inst << "\n");
2359
154k
      Position.insert(Inst);
2360
154k
    }
2361
  };
2362
2363
  /// Set the operand of an instruction with a new value.
2364
  class OperandSetter : public TypePromotionAction {
2365
    /// Original operand of the instruction.
2366
    Value *Origin;
2367
2368
    /// Index of the modified instruction.
2369
    unsigned Idx;
2370
2371
  public:
2372
    /// Set \p Idx operand of \p Inst with \p NewVal.
2373
    OperandSetter(Instruction *Inst, unsigned Idx, Value *NewVal)
2374
446k
        : TypePromotionAction(Inst), Idx(Idx) {
2375
446k
      LLVM_DEBUG(dbgs() << "Do: setOperand: " << Idx << "\n"
2376
446k
                        << "for:" << *Inst << "\n"
2377
446k
                        << "with:" << *NewVal << "\n");
2378
446k
      Origin = Inst->getOperand(Idx);
2379
446k
      Inst->setOperand(Idx, NewVal);
2380
446k
    }
2381
2382
    /// Restore the original value of the instruction.
2383
370k
    void undo() override {
2384
370k
      LLVM_DEBUG(dbgs() << "Undo: setOperand:" << Idx << "\n"
2385
370k
                        << "for: " << *Inst << "\n"
2386
370k
                        << "with: " << *Origin << "\n");
2387
370k
      Inst->setOperand(Idx, Origin);
2388
370k
    }
2389
  };
2390
2391
  /// Hide the operands of an instruction.
2392
  /// Do as if this instruction was not using any of its operands.
2393
  class OperandsHider : public TypePromotionAction {
2394
    /// The list of original operands.
2395
    SmallVector<Value *, 4> OriginalValues;
2396
2397
  public:
2398
    /// Remove \p Inst from the uses of the operands of \p Inst.
2399
13.9k
    OperandsHider(Instruction *Inst) : TypePromotionAction(Inst) {
2400
13.9k
      LLVM_DEBUG(dbgs() << "Do: OperandsHider: " << *Inst << "\n");
2401
13.9k
      unsigned NumOpnds = Inst->getNumOperands();
2402
13.9k
      OriginalValues.reserve(NumOpnds);
2403
27.8k
      for (unsigned It = 0; It < NumOpnds; 
++It13.9k
) {
2404
13.9k
        // Save the current operand.
2405
13.9k
        Value *Val = Inst->getOperand(It);
2406
13.9k
        OriginalValues.push_back(Val);
2407
13.9k
        // Set a dummy one.
2408
13.9k
        // We could use OperandSetter here, but that would imply an overhead
2409
13.9k
        // that we are not willing to pay.
2410
13.9k
        Inst->setOperand(It, UndefValue::get(Val->getType()));
2411
13.9k
      }
2412
13.9k
    }
2413
2414
    /// Restore the original list of uses.
2415
12.1k
    void undo() override {
2416
12.1k
      LLVM_DEBUG(dbgs() << "Undo: OperandsHider: " << *Inst << "\n");
2417
24.2k
      for (unsigned It = 0, EndIt = OriginalValues.size(); It != EndIt; 
++It12.1k
)
2418
12.1k
        Inst->setOperand(It, OriginalValues[It]);
2419
12.1k
    }
2420
  };
2421
2422
  /// Build a truncate instruction.
2423
  class TruncBuilder : public TypePromotionAction {
2424
    Value *Val;
2425
2426
  public:
2427
    /// Build a truncate instruction of \p Opnd producing a \p Ty
2428
    /// result.
2429
    /// trunc Opnd to Ty.
2430
23.0k
    TruncBuilder(Instruction *Opnd, Type *Ty) : TypePromotionAction(Opnd) {
2431
23.0k
      IRBuilder<> Builder(Opnd);
2432
23.0k
      Val = Builder.CreateTrunc(Opnd, Ty, "promoted");
2433
23.0k
      LLVM_DEBUG(dbgs() << "Do: TruncBuilder: " << *Val << "\n");
2434
23.0k
    }
2435
2436
    /// Get the built value.
2437
23.0k
    Value *getBuiltValue() { return Val; }
2438
2439
    /// Remove the built instruction.
2440
20.7k
    void undo() override {
2441
20.7k
      LLVM_DEBUG(dbgs() << "Undo: TruncBuilder: " << *Val << "\n");
2442
20.7k
      if (Instruction *IVal = dyn_cast<Instruction>(Val))
2443
20.7k
        IVal->eraseFromParent();
2444
20.7k
    }
2445
  };
2446
2447
  /// Build a sign extension instruction.
2448
  class SExtBuilder : public TypePromotionAction {
2449
    Value *Val;
2450
2451
  public:
2452
    /// Build a sign extension instruction of \p Opnd producing a \p Ty
2453
    /// result.
2454
    /// sext Opnd to Ty.
2455
    SExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty)
2456
62.6k
        : TypePromotionAction(InsertPt) {
2457
62.6k
      IRBuilder<> Builder(InsertPt);
2458
62.6k
      Val = Builder.CreateSExt(Opnd, Ty, "promoted");
2459
62.6k
      LLVM_DEBUG(dbgs() << "Do: SExtBuilder: " << *Val << "\n");
2460
62.6k
    }
2461
2462
    /// Get the built value.
2463
62.6k
    Value *getBuiltValue() { return Val; }
2464
2465
    /// Remove the built instruction.
2466
52.8k
    void undo() override {
2467
52.8k
      LLVM_DEBUG(dbgs() << "Undo: SExtBuilder: " << *Val << "\n");
2468
52.8k
      if (Instruction *IVal = dyn_cast<Instruction>(Val))
2469
52.8k
        IVal->eraseFromParent();
2470
52.8k
    }
2471
  };
2472
2473
  /// Build a zero extension instruction.
2474
  class ZExtBuilder : public TypePromotionAction {
2475
    Value *Val;
2476
2477
  public:
2478
    /// Build a zero extension instruction of \p Opnd producing a \p Ty
2479
    /// result.
2480
    /// zext Opnd to Ty.
2481
    ZExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty)
2482
12.2k
        : TypePromotionAction(InsertPt) {
2483
12.2k
      IRBuilder<> Builder(InsertPt);
2484
12.2k
      Val = Builder.CreateZExt(Opnd, Ty, "promoted");
2485
12.2k
      LLVM_DEBUG(dbgs() << "Do: ZExtBuilder: " << *Val << "\n");
2486
12.2k
    }
2487
2488
    /// Get the built value.
2489
12.2k
    Value *getBuiltValue() { return Val; }
2490
2491
    /// Remove the built instruction.
2492
10.5k
    void undo() override {
2493
10.5k
      LLVM_DEBUG(dbgs() << "Undo: ZExtBuilder: " << *Val << "\n");
2494
10.5k
      if (Instruction *IVal = dyn_cast<Instruction>(Val))
2495
10.5k
        IVal->eraseFromParent();
2496
10.5k
    }
2497
  };
2498
2499
  /// Mutate an instruction to another type.
2500
  class TypeMutator : public TypePromotionAction {
2501
    /// Record the original type.
2502
    Type *OrigTy;
2503
2504
  public:
2505
    /// Mutate the type of \p Inst into \p NewTy.
2506
    TypeMutator(Instruction *Inst, Type *NewTy)
2507
116k
        : TypePromotionAction(Inst), OrigTy(Inst->getType()) {
2508
116k
      LLVM_DEBUG(dbgs() << "Do: MutateType: " << *Inst << " with " << *NewTy
2509
116k
                        << "\n");
2510
116k
      Inst->mutateType(NewTy);
2511
116k
    }
2512
2513
    /// Mutate the instruction back to its original type.
2514
94.9k
    void undo() override {
2515
94.9k
      LLVM_DEBUG(dbgs() << "Undo: MutateType: " << *Inst << " with " << *OrigTy
2516
94.9k
                        << "\n");
2517
94.9k
      Inst->mutateType(OrigTy);
2518
94.9k
    }
2519
  };
2520
2521
  /// Replace the uses of an instruction by another instruction.
2522
  class UsesReplacer : public TypePromotionAction {
2523
    /// Helper structure to keep track of the replaced uses.
2524
    struct InstructionAndIdx {
2525
      /// The instruction using the instruction.
2526
      Instruction *Inst;
2527
2528
      /// The index where this instruction is used for Inst.
2529
      unsigned Idx;
2530
2531
      InstructionAndIdx(Instruction *Inst, unsigned Idx)
2532
336k
          : Inst(Inst), Idx(Idx) {}
2533
    };
2534
2535
    /// Keep track of the original uses (pair Instruction, Index).
2536
    SmallVector<InstructionAndIdx, 4> OriginalUses;
2537
    /// Keep track of the debug users.
2538
    SmallVector<DbgValueInst *, 1> DbgValues;
2539
2540
    using use_iterator = SmallVectorImpl<InstructionAndIdx>::iterator;
2541
2542
  public:
2543
    /// Replace all the use of \p Inst by \p New.
2544
147k
    UsesReplacer(Instruction *Inst, Value *New) : TypePromotionAction(Inst) {
2545
147k
      LLVM_DEBUG(dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *New
2546
147k
                        << "\n");
2547
147k
      // Record the original uses.
2548
336k
      for (Use &U : Inst->uses()) {
2549
336k
        Instruction *UserI = cast<Instruction>(U.getUser());
2550
336k
        OriginalUses.push_back(InstructionAndIdx(UserI, U.getOperandNo()));
2551
336k
      }
2552
147k
      // Record the debug uses separately. They are not in the instruction's
2553
147k
      // use list, but they are replaced by RAUW.
2554
147k
      findDbgValues(DbgValues, Inst);
2555
147k
2556
147k
      // Now, we can replace the uses.
2557
147k
      Inst->replaceAllUsesWith(New);
2558
147k
    }
2559
2560
    /// Reassign the original uses of Inst to Inst.
2561
123k
    void undo() override {
2562
123k
      LLVM_DEBUG(dbgs() << "Undo: UsersReplacer: " << *Inst << "\n");
2563
123k
      for (use_iterator UseIt = OriginalUses.begin(),
2564
123k
                        EndIt = OriginalUses.end();
2565
425k
           UseIt != EndIt; 
++UseIt302k
) {
2566
302k
        UseIt->Inst->setOperand(UseIt->Idx, Inst);
2567
302k
      }
2568
123k
      // RAUW has replaced all original uses with references to the new value,
2569
123k
      // including the debug uses. Since we are undoing the replacements,
2570
123k
      // the original debug uses must also be reinstated to maintain the
2571
123k
      // correctness and utility of debug value instructions.
2572
123k
      for (auto *DVI: DbgValues) {
2573
0
        LLVMContext &Ctx = Inst->getType()->getContext();
2574
0
        auto *MV = MetadataAsValue::get(Ctx, ValueAsMetadata::get(Inst));
2575
0
        DVI->setOperand(0, MV);
2576
0
      }
2577
123k
    }
2578
  };
2579
2580
  /// Remove an instruction from the IR.
2581
  class InstructionRemover : public TypePromotionAction {
2582
    /// Original position of the instruction.
2583
    InsertionHandler Inserter;
2584
2585
    /// Helper structure to hide all the link to the instruction. In other
2586
    /// words, this helps to do as if the instruction was removed.
2587
    OperandsHider Hider;
2588
2589
    /// Keep track of the uses replaced, if any.
2590
    UsesReplacer *Replacer = nullptr;
2591
2592
    /// Keep track of instructions removed.
2593
    SetOfInstrs &RemovedInsts;
2594
2595
  public:
2596
    /// Remove all reference of \p Inst and optionally replace all its
2597
    /// uses with New.
2598
    /// \p RemovedInsts Keep track of the instructions removed by this Action.
2599
    /// \pre If !Inst->use_empty(), then New != nullptr
2600
    InstructionRemover(Instruction *Inst, SetOfInstrs &RemovedInsts,
2601
                       Value *New = nullptr)
2602
        : TypePromotionAction(Inst), Inserter(Inst), Hider(Inst),
2603
13.9k
          RemovedInsts(RemovedInsts) {
2604
13.9k
      if (New)
2605
4.29k
        Replacer = new UsesReplacer(Inst, New);
2606
13.9k
      LLVM_DEBUG(dbgs() << "Do: InstructionRemover: " << *Inst << "\n");
2607
13.9k
      RemovedInsts.insert(Inst);
2608
13.9k
      /// The instructions removed here will be freed after completing
2609
13.9k
      /// optimizeBlock() for all blocks as we need to keep track of the
2610
13.9k
      /// removed instructions during promotion.
2611
13.9k
      Inst->removeFromParent();
2612
13.9k
    }
2613
2614
13.9k
    ~InstructionRemover() override { delete Replacer; }
2615
2616
    /// Resurrect the instruction and reassign it to the proper uses if
2617
    /// new value was provided when build this action.
2618
12.1k
    void undo() override {
2619
12.1k
      LLVM_DEBUG(dbgs() << "Undo: InstructionRemover: " << *Inst << "\n");
2620
12.1k
      Inserter.insert(Inst);
2621
12.1k
      if (Replacer)
2622
4.24k
        Replacer->undo();
2623
12.1k
      Hider.undo();
2624
12.1k
      RemovedInsts.erase(Inst);
2625
12.1k
    }
2626
  };
2627
2628
public:
2629
  /// Restoration point.
2630
  /// The restoration point is a pointer to an action instead of an iterator
2631
  /// because the iterator may be invalidated but not the pointer.
2632
  using ConstRestorationPt = const TypePromotionAction *;
2633
2634
  TypePromotionTransaction(SetOfInstrs &RemovedInsts)
2635
8.53M
      : RemovedInsts(RemovedInsts) {}
2636
2637
  /// Advocate every changes made in that transaction.
2638
  void commit();
2639
2640
  /// Undo all the changes made after the given point.
2641
  void rollback(ConstRestorationPt Point);
2642
2643
  /// Get the current restoration point.
2644
  ConstRestorationPt getRestorationPoint() const;
2645
2646
  /// \name API for IR modification with state keeping to support rollback.
2647
  /// @{
2648
  /// Same as Instruction::setOperand.
2649
  void setOperand(Instruction *Inst, unsigned Idx, Value *NewVal);
2650
2651
  /// Same as Instruction::eraseFromParent.
2652
  void eraseInstruction(Instruction *Inst, Value *NewVal = nullptr);
2653
2654
  /// Same as Value::replaceAllUsesWith.
2655
  void replaceAllUsesWith(Instruction *Inst, Value *New);
2656
2657
  /// Same as Value::mutateType.
2658
  void mutateType(Instruction *Inst, Type *NewTy);
2659
2660
  /// Same as IRBuilder::createTrunc.
2661
  Value *createTrunc(Instruction *Opnd, Type *Ty);
2662
2663
  /// Same as IRBuilder::createSExt.
2664
  Value *createSExt(Instruction *Inst, Value *Opnd, Type *Ty);
2665
2666
  /// Same as IRBuilder::createZExt.
2667
  Value *createZExt(Instruction *Inst, Value *Opnd, Type *Ty);
2668
2669
  /// Same as Instruction::moveBefore.
2670
  void moveBefore(Instruction *Inst, Instruction *Before);
2671
  /// @}
2672
2673
private:
2674
  /// The ordered list of actions made so far.
2675
  SmallVector<std::unique_ptr<TypePromotionAction>, 16> Actions;
2676
2677
  using CommitPt = SmallVectorImpl<std::unique_ptr<TypePromotionAction>>::iterator;
2678
2679
  SetOfInstrs &RemovedInsts;
2680
};
2681
2682
} // end anonymous namespace
2683
2684
void TypePromotionTransaction::setOperand(Instruction *Inst, unsigned Idx,
2685
446k
                                          Value *NewVal) {
2686
446k
  Actions.push_back(llvm::make_unique<TypePromotionTransaction::OperandSetter>(
2687
446k
      Inst, Idx, NewVal));
2688
446k
}
2689
2690
void TypePromotionTransaction::eraseInstruction(Instruction *Inst,
2691
13.9k
                                                Value *NewVal) {
2692
13.9k
  Actions.push_back(
2693
13.9k
      llvm::make_unique<TypePromotionTransaction::InstructionRemover>(
2694
13.9k
          Inst, RemovedInsts, NewVal));
2695
13.9k
}
2696
2697
void TypePromotionTransaction::replaceAllUsesWith(Instruction *Inst,
2698
143k
                                                  Value *New) {
2699
143k
  Actions.push_back(
2700
143k
      llvm::make_unique<TypePromotionTransaction::UsesReplacer>(Inst, New));
2701
143k
}
2702
2703
116k
void TypePromotionTransaction::mutateType(Instruction *Inst, Type *NewTy) {
2704
116k
  Actions.push_back(
2705
116k
      llvm::make_unique<TypePromotionTransaction::TypeMutator>(Inst, NewTy));
2706
116k
}
2707
2708
Value *TypePromotionTransaction::createTrunc(Instruction *Opnd,
2709
23.0k
                                             Type *Ty) {
2710
23.0k
  std::unique_ptr<TruncBuilder> Ptr(new TruncBuilder(Opnd, Ty));
2711
23.0k
  Value *Val = Ptr->getBuiltValue();
2712
23.0k
  Actions.push_back(std::move(Ptr));
2713
23.0k
  return Val;
2714
23.0k
}
2715
2716
Value *TypePromotionTransaction::createSExt(Instruction *Inst,
2717
62.6k
                                            Value *Opnd, Type *Ty) {
2718
62.6k
  std::unique_ptr<SExtBuilder> Ptr(new SExtBuilder(Inst, Opnd, Ty));
2719
62.6k
  Value *Val = Ptr->getBuiltValue();
2720
62.6k
  Actions.push_back(std::move(Ptr));
2721
62.6k
  return Val;
2722
62.6k
}
2723
2724
Value *TypePromotionTransaction::createZExt(Instruction *Inst,
2725
12.2k
                                            Value *Opnd, Type *Ty) {
2726
12.2k
  std::unique_ptr<ZExtBuilder> Ptr(new ZExtBuilder(Inst, Opnd, Ty));
2727
12.2k
  Value *Val = Ptr->getBuiltValue();
2728
12.2k
  Actions.push_back(std::move(Ptr));
2729
12.2k
  return Val;
2730
12.2k
}
2731
2732
void TypePromotionTransaction::moveBefore(Instruction *Inst,
2733
186k
                                          Instruction *Before) {
2734
186k
  Actions.push_back(
2735
186k
      llvm::make_unique<TypePromotionTransaction::InstructionMoveBefore>(
2736
186k
          Inst, Before));
2737
186k
}
2738
2739
TypePromotionTransaction::ConstRestorationPt
2740
29.4M
TypePromotionTransaction::getRestorationPoint() const {
2741
29.4M
  return !Actions.empty() ? 
Actions.back().get()41.4k
:
nullptr29.4M
;
2742
29.4M
}
2743
2744
7.72M
void TypePromotionTransaction::commit() {
2745
7.89M
  for (CommitPt It = Actions.begin(), EndIt = Actions.end(); It != EndIt;
2746
7.72M
       
++It169k
)
2747
169k
    (*It)->commit();
2748
7.72M
  Actions.clear();
2749
7.72M
}
2750
2751
void TypePromotionTransaction::rollback(
2752
1.74M
    TypePromotionTransaction::ConstRestorationPt Point) {
2753
2.58M
  while (!Actions.empty() && 
Point != Actions.back().get()854k
) {
2754
835k
    std::unique_ptr<TypePromotionAction> Curr = Actions.pop_back_val();
2755
835k
    Curr->undo();
2756
835k
  }
2757
1.74M
}
2758
2759
namespace {
2760
2761
/// A helper class for matching addressing modes.
2762
///
2763
/// This encapsulates the logic for matching the target-legal addressing modes.
2764
class AddressingModeMatcher {
2765
  SmallVectorImpl<Instruction*> &AddrModeInsts;
2766
  const TargetLowering &TLI;
2767
  const TargetRegisterInfo &TRI;
2768
  const DataLayout &DL;
2769
2770
  /// AccessTy/MemoryInst - This is the type for the access (e.g. double) and
2771
  /// the memory instruction that we're computing this address for.
2772
  Type *AccessTy;
2773
  unsigned AddrSpace;
2774
  Instruction *MemoryInst;
2775
2776
  /// This is the addressing mode that we're building up. This is
2777
  /// part of the return value of this addressing mode matching stuff.
2778
  ExtAddrMode &AddrMode;
2779
2780
  /// The instructions inserted by other CodeGenPrepare optimizations.
2781
  const SetOfInstrs &InsertedInsts;
2782
2783
  /// A map from the instructions to their type before promotion.
2784
  InstrToOrigTy &PromotedInsts;
2785
2786
  /// The ongoing transaction where every action should be registered.
2787
  TypePromotionTransaction &TPT;
2788
2789
  // A GEP which has too large offset to be folded into the addressing mode.
2790
  std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP;
2791
2792
  /// This is set to true when we should not do profitability checks.
2793
  /// When true, IsProfitableToFoldIntoAddressingMode always returns true.
2794
  bool IgnoreProfitability;
2795
2796
  AddressingModeMatcher(
2797
      SmallVectorImpl<Instruction *> &AMI, const TargetLowering &TLI,
2798
      const TargetRegisterInfo &TRI, Type *AT, unsigned AS, Instruction *MI,
2799
      ExtAddrMode &AM, const SetOfInstrs &InsertedInsts,
2800
      InstrToOrigTy &PromotedInsts, TypePromotionTransaction &TPT,
2801
      std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP)
2802
      : AddrModeInsts(AMI), TLI(TLI), TRI(TRI),
2803
        DL(MI->getModule()->getDataLayout()), AccessTy(AT), AddrSpace(AS),
2804
        MemoryInst(MI), AddrMode(AM), InsertedInsts(InsertedInsts),
2805
8.27M
        PromotedInsts(PromotedInsts), TPT(TPT), LargeOffsetGEP(LargeOffsetGEP) {
2806
8.27M
    IgnoreProfitability = false;
2807
8.27M
  }
2808
2809
public:
2810
  /// Find the maximal addressing mode that a load/store of V can fold,
2811
  /// give an access type of AccessTy.  This returns a list of involved
2812
  /// instructions in AddrModeInsts.
2813
  /// \p InsertedInsts The instructions inserted by other CodeGenPrepare
2814
  /// optimizations.
2815
  /// \p PromotedInsts maps the instructions to their type before promotion.
2816
  /// \p The ongoing transaction where every action should be registered.
2817
  static ExtAddrMode
2818
  Match(Value *V, Type *AccessTy, unsigned AS, Instruction *MemoryInst,
2819
        SmallVectorImpl<Instruction *> &AddrModeInsts,
2820
        const TargetLowering &TLI, const TargetRegisterInfo &TRI,
2821
        const SetOfInstrs &InsertedInsts, InstrToOrigTy &PromotedInsts,
2822
        TypePromotionTransaction &TPT,
2823
7.83M
        std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP) {
2824
7.83M
    ExtAddrMode Result;
2825
7.83M
2826
7.83M
    bool Success = AddressingModeMatcher(AddrModeInsts, TLI, TRI, AccessTy, AS,
2827
7.83M
                                         MemoryInst, Result, InsertedInsts,
2828
7.83M
                                         PromotedInsts, TPT, LargeOffsetGEP)
2829
7.83M
                       .matchAddr(V, 0);
2830
7.83M
    (void)Success; assert(Success && "Couldn't select *anything*?");
2831
7.83M
    return Result;
2832
7.83M
  }
2833
2834
private:
2835
  bool matchScaledValue(Value *ScaleReg, int64_t Scale, unsigned Depth);
2836
  bool matchAddr(Value *Addr, unsigned Depth);
2837
  bool matchOperationAddr(User *AddrInst, unsigned Opcode, unsigned Depth,
2838
                          bool *MovedAway = nullptr);
2839
  bool isProfitableToFoldIntoAddressingMode(Instruction *I,
2840
                                            ExtAddrMode &AMBefore,
2841
                                            ExtAddrMode &AMAfter);
2842
  bool valueAlreadyLiveAtInst(Value *Val, Value *KnownLive1, Value *KnownLive2);
2843
  bool isPromotionProfitable(unsigned NewCost, unsigned OldCost,
2844
                             Value *PromotedOperand) const;
2845
};
2846
2847
class PhiNodeSet;
2848
2849
/// An iterator for PhiNodeSet.
2850
class PhiNodeSetIterator {
2851
  PhiNodeSet * const Set;
2852
  size_t CurrentIndex = 0;
2853
2854
public:
2855
  /// The constructor. Start should point to either a valid element, or be equal
2856
  /// to the size of the underlying SmallVector of the PhiNodeSet.
2857
  PhiNodeSetIterator(PhiNodeSet * const Set, size_t Start);
2858
  PHINode * operator*() const;
2859
  PhiNodeSetIterator& operator++();
2860
  bool operator==(const PhiNodeSetIterator &RHS) const;
2861
  bool operator!=(const PhiNodeSetIterator &RHS) const;
2862
};
2863
2864
/// Keeps a set of PHINodes.
2865
///
2866
/// This is a minimal set implementation for a specific use case:
2867
/// It is very fast when there are very few elements, but also provides good
2868
/// performance when there are many. It is similar to SmallPtrSet, but also
2869
/// provides iteration by insertion order, which is deterministic and stable
2870
/// across runs. It is also similar to SmallSetVector, but provides removing
2871
/// elements in O(1) time. This is achieved by not actually removing the element
2872
/// from the underlying vector, so comes at the cost of using more memory, but
2873
/// that is fine, since PhiNodeSets are used as short lived objects.
2874
class PhiNodeSet {
2875
  friend class PhiNodeSetIterator;
2876
2877
  using MapType = SmallDenseMap<PHINode *, size_t, 32>;
2878
  using iterator =  PhiNodeSetIterator;
2879
2880
  /// Keeps the elements in the order of their insertion in the underlying
2881
  /// vector. To achieve constant time removal, it never deletes any element.
2882
  SmallVector<PHINode *, 32> NodeList;
2883
2884
  /// Keeps the elements in the underlying set implementation. This (and not the
2885
  /// NodeList defined above) is the source of truth on whether an element
2886
  /// is actually in the collection.
2887
  MapType NodeMap;
2888
2889
  /// Points to the first valid (not deleted) element when the set is not empty
2890
  /// and the value is not zero. Equals to the size of the underlying vector
2891
  /// when the set is empty. When the value is 0, as in the beginning, the
2892
  /// first element may or may not be valid.
2893
  size_t FirstValidElement = 0;
2894
2895
public:
2896
  /// Inserts a new element to the collection.
2897
  /// \returns true if the element is actually added, i.e. was not in the
2898
  /// collection before the operation.
2899
4.92k
  bool insert(PHINode *Ptr) {
2900
4.92k
    if (NodeMap.insert(std::make_pair(Ptr, NodeList.size())).second) {
2901
4.92k
      NodeList.push_back(Ptr);
2902
4.92k
      return true;
2903
4.92k
    }
2904
0
    return false;
2905
0
  }
2906
2907
  /// Removes the element from the collection.
2908
  /// \returns whether the element is actually removed, i.e. was in the
2909
  /// collection before the operation.
2910
161
  bool erase(PHINode *Ptr) {
2911
161
    auto it = NodeMap.find(Ptr);
2912
161
    if (it != NodeMap.end()) {
2913
160
      NodeMap.erase(Ptr);
2914
160
      SkipRemovedElements(FirstValidElement);
2915
160
      return true;
2916
160
    }
2917
1
    return false;
2918
1
  }
2919
2920
  /// Removes all elements and clears the collection.
2921
4.53k
  void clear() {
2922
4.53k
    NodeMap.clear();
2923
4.53k
    NodeList.clear();
2924
4.53k
    FirstValidElement = 0;
2925
4.53k
  }
2926
2927
  /// \returns an iterator that will iterate the elements in the order of
2928
  /// insertion.
2929
9.21k
  iterator begin() {
2930
9.21k
    if (FirstValidElement == 0)
2931
9.21k
      SkipRemovedElements(FirstValidElement);
2932
9.21k
    return PhiNodeSetIterator(this, FirstValidElement);
2933
9.21k
  }
2934
2935
  /// \returns an iterator that points to the end of the collection.
2936
4.53k
  iterator end() { return PhiNodeSetIterator(this, NodeList.size()); }
2937
2938
  /// Returns the number of elements in the collection.
2939
6.43k
  size_t size() const {
2940
6.43k
    return NodeMap.size();
2941
6.43k
  }
2942
2943
  /// \returns 1 if the given element is in the collection, and 0 if otherwise.
2944
702
  size_t count(PHINode *Ptr) const {
2945
702
    return NodeMap.count(Ptr);
2946
702
  }
2947
2948
private:
2949
  /// Updates the CurrentIndex so that it will point to a valid element.
2950
  ///
2951
  /// If the element of NodeList at CurrentIndex is valid, it does not
2952
  /// change it. If there are no more valid elements, it updates CurrentIndex
2953
  /// to point to the end of the NodeList.
2954
14.1k
  void SkipRemovedElements(size_t &CurrentIndex) {
2955
14.2k
    while (CurrentIndex < NodeList.size()) {
2956
9.61k
      auto it = NodeMap.find(NodeList[CurrentIndex]);
2957
9.61k
      // If the element has been deleted and added again later, NodeMap will
2958
9.61k
      // point to a different index, so CurrentIndex will still be invalid.
2959
9.61k
      if (it != NodeMap.end() && 
it->second == CurrentIndex9.45k
)
2960
9.45k
        break;
2961
160
      ++CurrentIndex;
2962
160
    }
2963
14.1k
  }
2964
};
2965
2966
PhiNodeSetIterator::PhiNodeSetIterator(PhiNodeSet *const Set, size_t Start)
2967
13.7k
    : Set(Set), CurrentIndex(Start) {}
2968
2969
9.45k
PHINode * PhiNodeSetIterator::operator*() const {
2970
9.45k
  assert(CurrentIndex < Set->NodeList.size() &&
2971
9.45k
         "PhiNodeSet access out of range");
2972
9.45k
  return Set->NodeList[CurrentIndex];
2973
9.45k
}
2974
2975
4.76k
PhiNodeSetIterator& PhiNodeSetIterator::operator++() {
2976
4.76k
  assert(CurrentIndex < Set->NodeList.size() &&
2977
4.76k
         "PhiNodeSet access out of range");
2978
4.76k
  ++CurrentIndex;
2979
4.76k
  Set->SkipRemovedElements(CurrentIndex);
2980
4.76k
  return *this;
2981
4.76k
}
2982
2983
9.29k
bool PhiNodeSetIterator::operator==(const PhiNodeSetIterator &RHS) const {
2984
9.29k
  return CurrentIndex == RHS.CurrentIndex;
2985
9.29k
}
2986
2987
9.29k
bool PhiNodeSetIterator::operator!=(const PhiNodeSetIterator &RHS) const {
2988
9.29k
  return !((*this) == RHS);
2989
9.29k
}
2990
2991
/// Keep track of simplification of Phi nodes.
2992
/// Accept the set of all phi nodes and erase phi node from this set
2993
/// if it is simplified.
2994
class SimplificationTracker {
2995
  DenseMap<Value *, Value *> Storage;
2996
  const SimplifyQuery &SQ;
2997
  // Tracks newly created Phi nodes. The elements are iterated by insertion
2998
  // order.
2999
  PhiNodeSet AllPhiNodes;
3000
  // Tracks newly created Select nodes.
3001
  SmallPtrSet<SelectInst *, 32> AllSelectNodes;
3002
3003
public:
3004
  SimplificationTracker(const SimplifyQuery &sq)
3005
5.40k
      : SQ(sq) {}
3006
3007
19.8k
  Value *Get(Value *V) {
3008
19.9k
    do {
3009
19.9k
      auto SV = Storage.find(V);
3010
19.9k
      if (SV == Storage.end())
3011
19.8k
        return V;
3012
126
      V = SV->second;
3013
126
    } while (true);
3014
19.8k
  }
3015
3016
5.68k
  Value *Simplify(Value *Val) {
3017
5.68k
    SmallVector<Value *, 32> WorkList;
3018
5.68k
    SmallPtrSet<Value *, 32> Visited;
3019
5.68k
    WorkList.push_back(Val);
3020
11.3k
    while (!WorkList.empty()) {
3021
5.68k
      auto P = WorkList.pop_back_val();
3022
5.68k
      if (!Visited.insert(P).second)
3023
0
        continue;
3024
5.68k
      if (auto *PI = dyn_cast<Instruction>(P))
3025
5.68k
        if (Value *V = SimplifyInstruction(cast<Instruction>(PI), SQ)) {
3026
1
          for (auto *U : PI->users())
3027
0
            WorkList.push_back(cast<Value>(U));
3028
1
          Put(PI, V);
3029
1
          PI->replaceAllUsesWith(V);
3030
1
          if (auto *PHI = dyn_cast<PHINode>(PI))
3031
1
            AllPhiNodes.erase(PHI);
3032
1
          if (auto *Select = dyn_cast<SelectInst>(PI))
3033
0
            AllSelectNodes.erase(Select);
3034
1
          PI->eraseFromParent();
3035
1
        }
3036
5.68k
    }
3037
5.68k
    return Get(Val);
3038
5.68k
  }
3039
3040
135
  void Put(Value *From, Value *To) {
3041
135
    Storage.insert({ From, To });
3042
135
  }
3043
3044
134
  void ReplacePhi(PHINode *From, PHINode *To) {
3045
134
    Value* OldReplacement = Get(From);
3046
136
    while (OldReplacement != From) {
3047
2
      From = To;
3048
2
      To = dyn_cast<PHINode>(OldReplacement);
3049
2
      OldReplacement = Get(From);
3050
2
    }
3051
134
    assert(Get(To) == To && "Replacement PHI node is already replaced.");
3052
134
    Put(From, To);
3053
134
    From->replaceAllUsesWith(To);
3054
134
    AllPhiNodes.erase(From);
3055
134
    From->eraseFromParent();
3056
134
  }
3057
3058
5.40k
  PhiNodeSet& newPhiNodes() { return AllPhiNodes; }
3059
3060
4.92k
  void insertNewPhi(PHINode *PN) { AllPhiNodes.insert(PN); }
3061
3062
764
  void insertNewSelect(SelectInst *SI) { AllSelectNodes.insert(SI); }
3063
3064
875
  unsigned countNewPhiNodes() const { return AllPhiNodes.size(); }
3065
3066
875
  unsigned countNewSelectNodes() const { return AllSelectNodes.size(); }
3067
3068
4.53k
  void destroyNewNodes(Type *CommonType) {
3069
4.53k
    // For safe erasing, replace the uses with dummy value first.
3070
4.53k
    auto Dummy = UndefValue::get(CommonType);
3071
4.76k
    for (auto I : AllPhiNodes) {
3072
4.76k
      I->replaceAllUsesWith(Dummy);
3073
4.76k
      I->eraseFromParent();
3074
4.76k
    }
3075
4.53k
    AllPhiNodes.clear();
3076
4.53k
    for (auto I : AllSelectNodes) {
3077
26
      I->replaceAllUsesWith(Dummy);
3078
26
      I->eraseFromParent();
3079
26
    }
3080
4.53k
    AllSelectNodes.clear();
3081
4.53k
  }
3082
};
3083
3084
/// A helper class for combining addressing modes.
3085
class AddressingModeCombiner {
3086
  typedef DenseMap<Value *, Value *> FoldAddrToValueMapping;
3087
  typedef std::pair<PHINode *, PHINode *> PHIPair;
3088
3089
private:
3090
  /// The addressing modes we've collected.
3091
  SmallVector<ExtAddrMode, 16> AddrModes;
3092
3093
  /// The field in which the AddrModes differ, when we have more than one.
3094
  ExtAddrMode::FieldName DifferentField = ExtAddrMode::NoField;
3095
3096
  /// Are the AddrModes that we have all just equal to their original values?
3097
  bool AllAddrModesTrivial = true;
3098
3099
  /// Common Type for all different fields in addressing modes.
3100
  Type *CommonType;
3101
3102
  /// SimplifyQuery for simplifyInstruction utility.
3103
  const SimplifyQuery &SQ;
3104
3105
  /// Original Address.
3106
  Value *Original;
3107
3108
public:
3109
  AddressingModeCombiner(const SimplifyQuery &_SQ, Value *OriginalValue)
3110
7.72M
      : CommonType(nullptr), SQ(_SQ), Original(OriginalValue) {}
3111
3112
  /// Get the combined AddrMode
3113
7.63M
  const ExtAddrMode &getAddrMode() const {
3114
7.63M
    return AddrModes[0];
3115
7.63M
  }
3116
3117
  /// Add a new AddrMode if it's compatible with the AddrModes we already
3118
  /// have.
3119
  /// \return True iff we succeeded in doing so.
3120
7.83M
  bool addNewAddrMode(ExtAddrMode &NewAddrMode) {
3121
7.83M
    // Take note of if we have any non-trivial AddrModes, as we need to detect
3122
7.83M
    // when all AddrModes are trivial as then we would introduce a phi or select
3123
7.83M
    // which just duplicates what's already there.
3124
7.83M
    AllAddrModesTrivial = AllAddrModesTrivial && 
NewAddrMode.isTrivial()7.77M
;
3125
7.83M
3126
7.83M
    // If this is the first addrmode then everything is fine.
3127
7.83M
    if (AddrModes.empty()) {
3128
7.72M
      AddrModes.emplace_back(NewAddrMode);
3129
7.72M
      return true;
3130
7.72M
    }
3131
106k
3132
106k
    // Figure out how different this is from the other address modes, which we
3133
106k
    // can do just by comparing against the first one given that we only care
3134
106k
    // about the cumulative difference.
3135
106k
    ExtAddrMode::FieldName ThisDifferentField =
3136
106k
      AddrModes[0].compare(NewAddrMode);
3137
106k
    if (DifferentField == ExtAddrMode::NoField)
3138
94.2k
      DifferentField = ThisDifferentField;
3139
12.2k
    else if (DifferentField != ThisDifferentField)
3140
5.86k
      DifferentField = ExtAddrMode::MultipleFields;
3141
106k
3142
106k
    // If NewAddrMode differs in more than one dimension we cannot handle it.
3143
106k
    bool CanHandle = DifferentField != ExtAddrMode::MultipleFields;
3144
106k
3145
106k
    // If Scale Field is different then we reject.
3146
106k
    CanHandle = CanHandle && 
DifferentField != ExtAddrMode::ScaleField26.7k
;
3147
106k
3148
106k
    // We also must reject the case when base offset is different and
3149
106k
    // scale reg is not null, we cannot handle this case due to merge of
3150
106k
    // different offsets will be used as ScaleReg.
3151
106k
    CanHandle = CanHandle && 
(26.7k
DifferentField != ExtAddrMode::BaseOffsField26.7k
||
3152
26.7k
                              
!NewAddrMode.ScaledReg4.71k
);
3153
106k
3154
106k
    // We also must reject the case when GV is different and BaseReg installed
3155
106k
    // due to we want to use base reg as a merge of GV values.
3156
106k
    CanHandle = CanHandle && 
(26.7k
DifferentField != ExtAddrMode::BaseGVField26.7k
||
3157
26.7k
                              
!NewAddrMode.HasBaseReg14
);
3158
106k
3159
106k
    // Even if NewAddMode is the same we still need to collect it due to
3160
106k
    // original value is different. And later we will need all original values
3161
106k
    // as anchors during finding the common Phi node.
3162
106k
    if (CanHandle)
3163
26.7k
      AddrModes.emplace_back(NewAddrMode);
3164
79.7k
    else
3165
79.7k
      AddrModes.clear();
3166
106k
3167
106k
    return CanHandle;
3168
106k
  }
3169
3170
  /// Combine the addressing modes we've collected into a single
3171
  /// addressing mode.
3172
  /// \return True iff we successfully combined them or we only had one so
3173
  /// didn't need to combine them anyway.
3174
7.72M
  bool combineAddrModes() {
3175
7.72M
    // If we have no AddrModes then they can't be combined.
3176
7.72M
    if (AddrModes.size() == 0)
3177
79.7k
      return false;
3178
7.64M
3179
7.64M
    // A single AddrMode can trivially be combined.
3180
7.64M
    if (AddrModes.size() == 1 || 
DifferentField == ExtAddrMode::NoField13.3k
)
3181
7.63M
      return true;
3182
12.4k
3183
12.4k
    // If the AddrModes we collected are all just equal to the value they are
3184
12.4k
    // derived from then combining them wouldn't do anything useful.
3185
12.4k
    if (AllAddrModesTrivial)
3186
7.02k
      return false;
3187
5.41k
3188
5.41k
    if (!addrModeCombiningAllowed())
3189
0
      return false;
3190
5.41k
3191
5.41k
    // Build a map between <original value, basic block where we saw it> to
3192
5.41k
    // value of base register.
3193
5.41k
    // Bail out if there is no common type.
3194
5.41k
    FoldAddrToValueMapping Map;
3195
5.41k
    if (!initializeMap(Map))
3196
4
      return false;
3197
5.40k
3198
5.40k
    Value *CommonValue = findCommon(Map);
3199
5.40k
    if (CommonValue)
3200
875
      AddrModes[0].SetCombinedField(DifferentField, CommonValue, AddrModes);
3201
5.40k
    return CommonValue != nullptr;
3202
5.40k
  }
3203
3204
private:
3205
  /// Initialize Map with anchor values. For address seen
3206
  /// we set the value of different field saw in this address.
3207
  /// At the same time we find a common type for different field we will
3208
  /// use to create new Phi/Select nodes. Keep it in CommonType field.
3209
  /// Return false if there is no common type found.
3210
5.41k
  bool initializeMap(FoldAddrToValueMapping &Map) {
3211
5.41k
    // Keep track of keys where the value is null. We will need to replace it
3212
5.41k
    // with constant null when we know the common type.
3213
5.41k
    SmallVector<Value *, 2> NullValue;
3214
5.41k
    Type *IntPtrTy = SQ.DL.getIntPtrType(AddrModes[0].OriginalValue->getType());
3215
12.4k
    for (auto &AM : AddrModes) {
3216
12.4k
      Value *DV = AM.GetFieldAsValue(DifferentField, IntPtrTy);
3217
12.4k
      if (DV) {
3218
12.4k
        auto *Type = DV->getType();
3219
12.4k
        if (CommonType && 
CommonType != Type6.99k
)
3220
4
          return false;
3221
12.3k
        CommonType = Type;
3222
12.3k
        Map[AM.OriginalValue] = DV;
3223
12.3k
      } else {
3224
41
        NullValue.push_back(AM.OriginalValue);
3225
41
      }
3226
12.4k
    }
3227
5.41k
    assert(CommonType && "At least one non-null value must be!");
3228
5.40k
    for (auto *V : NullValue)
3229
37
      Map[V] = Constant::getNullValue(CommonType);
3230
5.40k
    return true;
3231
5.41k
  }
3232
3233
  /// We have mapping between value A and other value B where B was a field in
3234
  /// addressing mode represented by A. Also we have an original value C
3235
  /// representing an address we start with. Traversing from C through phi and
3236
  /// selects we ended up with A's in a map. This utility function tries to find
3237
  /// a value V which is a field in addressing mode C and traversing through phi
3238
  /// nodes and selects we will end up in corresponded values B in a map.
3239
  /// The utility will create a new Phi/Selects if needed.
3240
  // The simple example looks as follows:
3241
  // BB1:
3242
  //   p1 = b1 + 40
3243
  //   br cond BB2, BB3
3244
  // BB2:
3245
  //   p2 = b2 + 40
3246
  //   br BB3
3247
  // BB3:
3248
  //   p = phi [p1, BB1], [p2, BB2]
3249
  //   v = load p
3250
  // Map is
3251
  //   p1 -> b1
3252
  //   p2 -> b2
3253
  // Request is
3254
  //   p -> ?
3255
  // The function tries to find or build phi [b1, BB1], [b2, BB2] in BB3.
3256
5.40k
  Value *findCommon(FoldAddrToValueMapping &Map) {
3257
5.40k
    // Tracks the simplification of newly created phi nodes. The reason we use
3258
5.40k
    // this mapping is because we will add new created Phi nodes in AddrToBase.
3259
5.40k
    // Simplification of Phi nodes is recursive, so some Phi node may
3260
5.40k
    // be simplified after we added it to AddrToBase. In reality this
3261
5.40k
    // simplification is possible only if original phi/selects were not
3262
5.40k
    // simplified yet.
3263
5.40k
    // Using this mapping we can find the current value in AddrToBase.
3264
5.40k
    SimplificationTracker ST(SQ);
3265
5.40k
3266
5.40k
    // First step, DFS to create PHI nodes for all intermediate blocks.
3267
5.40k
    // Also fill traverse order for the second step.
3268
5.40k
    SmallVector<Value *, 32> TraverseOrder;
3269
5.40k
    InsertPlaceholders(Map, TraverseOrder, ST);
3270
5.40k
3271
5.40k
    // Second Step, fill new nodes by merged values and simplify if possible.
3272
5.40k
    FillPlaceholders(Map, TraverseOrder, ST);
3273
5.40k
3274
5.40k
    if (!AddrSinkNewSelects && 
ST.countNewSelectNodes() > 00
) {
3275
0
      ST.destroyNewNodes(CommonType);
3276
0
      return nullptr;
3277
0
    }
3278
5.40k
3279
5.40k
    // Now we'd like to match New Phi nodes to existed ones.
3280
5.40k
    unsigned PhiNotMatchedCount = 0;
3281
5.40k
    if (!MatchPhiSet(ST, AddrSinkNewPhis, PhiNotMatchedCount)) {
3282
4.53k
      ST.destroyNewNodes(CommonType);
3283
4.53k
      return nullptr;
3284
4.53k
    }
3285
875
3286
875
    auto *Result = ST.Get(Map.find(Original)->second);
3287
875
    if (Result) {
3288
875
      NumMemoryInstsPhiCreated += ST.countNewPhiNodes() + PhiNotMatchedCount;
3289
875
      NumMemoryInstsSelectCreated += ST.countNewSelectNodes();
3290
875
    }
3291
875
    return Result;
3292
875
  }
3293
3294
  /// Try to match PHI node to Candidate.
3295
  /// Matcher tracks the matched Phi nodes.
3296
  bool MatchPhiNode(PHINode *PHI, PHINode *Candidate,
3297
                    SmallSetVector<PHIPair, 8> &Matcher,
3298
13.7k
                    PhiNodeSet &PhiNodesToMatch) {
3299
13.7k
    SmallVector<PHIPair, 8> WorkList;
3300
13.7k
    Matcher.insert({ PHI, Candidate });
3301
13.7k
    SmallSet<PHINode *, 8> MatchedPHIs;
3302
13.7k
    MatchedPHIs.insert(PHI);
3303
13.7k
    WorkList.push_back({ PHI, Candidate });
3304
13.7k
    SmallSet<PHIPair, 8> Visited;
3305
13.8k
    while (!WorkList.empty()) {
3306
13.7k
      auto Item = WorkList.pop_back_val();
3307
13.7k
      if (!Visited.insert(Item).second)
3308
3
        continue;
3309
13.7k
      // We iterate over all incoming values to Phi to compare them.
3310
13.7k
      // If values are different and both of them Phi and the first one is a
3311
13.7k
      // Phi we added (subject to match) and both of them is in the same basic
3312
13.7k
      // block then we can match our pair if values match. So we state that
3313
13.7k
      // these values match and add it to work list to verify that.
3314
14.2k
      
for (auto B : Item.first->blocks())13.7k
{
3315
14.2k
        Value *FirstValue = Item.first->getIncomingValueForBlock(B);
3316
14.2k
        Value *SecondValue = Item.second->getIncomingValueForBlock(B);
3317
14.2k
        if (FirstValue == SecondValue)
3318
419
          continue;
3319
13.8k
3320
13.8k
        PHINode *FirstPhi = dyn_cast<PHINode>(FirstValue);
3321
13.8k
        PHINode *SecondPhi = dyn_cast<PHINode>(SecondValue);
3322
13.8k
3323
13.8k
        // One of them is not Phi or
3324
13.8k
        // The first one is not Phi node from the set we'd like to match or
3325
13.8k
        // Phi nodes from different basic blocks then
3326
13.8k
        // we will not be able to match.
3327
13.8k
        if (!FirstPhi || 
!SecondPhi6.00k
||
!PhiNodesToMatch.count(FirstPhi)702
||
3328
13.8k
            
FirstPhi->getParent() != SecondPhi->getParent()232
)
3329
13.5k
          return false;
3330
208
3331
208
        // If we already matched them then continue.
3332
208
        if (Matcher.count({ FirstPhi, SecondPhi }))
3333
2
          continue;
3334
206
        // So the values are different and does not match. So we need them to
3335
206
        // match. (But we register no more than one match per PHI node, so that
3336
206
        // we won't later try to replace them twice.)
3337
206
        if (!MatchedPHIs.insert(FirstPhi).second)
3338
21
          Matcher.insert({ FirstPhi, SecondPhi });
3339
206
        // But me must check it.
3340
206
        WorkList.push_back({ FirstPhi, SecondPhi });
3341
206
      }
3342
13.7k
    }
3343
13.7k
    
return true129
;
3344
13.7k
  }
3345
3346
  /// For the given set of PHI nodes (in the SimplificationTracker) try
3347
  /// to find their equivalents.
3348
  /// Returns false if this matching fails and creation of new Phi is disabled.
3349
  bool MatchPhiSet(SimplificationTracker &ST, bool AllowNewPhiNodes,
3350
5.40k
                   unsigned &PhiNotMatchedCount) {
3351
5.40k
    // Matched and PhiNodesToMatch iterate their elements in a deterministic
3352
5.40k
    // order, so the replacements (ReplacePhi) are also done in a deterministic
3353
5.40k
    // order.
3354
5.40k
    SmallSetVector<PHIPair, 8> Matched;
3355
5.40k
    SmallPtrSet<PHINode *, 8> WillNotMatch;
3356
5.40k
    PhiNodeSet &PhiNodesToMatch = ST.newPhiNodes();
3357
5.56k
    while (PhiNodesToMatch.size()) {
3358
4.68k
      PHINode *PHI = *PhiNodesToMatch.begin();
3359
4.68k
3360
4.68k
      // Add us, if no Phi nodes in the basic block we do not match.
3361
4.68k
      WillNotMatch.clear();
3362
4.68k
      WillNotMatch.insert(PHI);
3363
4.68k
3364
4.68k
      // Traverse all Phis until we found equivalent or fail to do that.
3365
4.68k
      bool IsMatched = false;
3366
18.3k
      for (auto &P : PHI->getParent()->phis()) {
3367
18.3k
        if (&P == PHI)
3368
4.64k
          continue;
3369
13.7k
        if ((IsMatched = MatchPhiNode(PHI, &P, Matched, PhiNodesToMatch)))
3370
129
          break;
3371
13.5k
        // If it does not match, collect all Phi nodes from matcher.
3372
13.5k
        // if we end up with no match, them all these Phi nodes will not match
3373
13.5k
        // later.
3374
13.5k
        for (auto M : Matched)
3375
13.6k
          WillNotMatch.insert(M.first);
3376
13.5k
        Matched.clear();
3377
13.5k
      }
3378
4.68k
      if (IsMatched) {
3379
129
        // Replace all matched values and erase them.
3380
129
        for (auto MV : Matched)
3381
134
          ST.ReplacePhi(MV.first, MV.second);
3382
129
        Matched.clear();
3383
129
        continue;
3384
129
      }
3385
4.55k
      // If we are not allowed to create new nodes then bail out.
3386
4.55k
      if (!AllowNewPhiNodes)
3387
4.53k
        return false;
3388
26
      // Just remove all seen values in matcher. They will not match anything.
3389
26
      PhiNotMatchedCount += WillNotMatch.size();
3390
26
      for (auto *P : WillNotMatch)
3391
26
        PhiNodesToMatch.erase(P);
3392
26
    }
3393
5.40k
    
return true875
;
3394
5.40k
  }
3395
  /// Fill the placeholders with values from predecessors and simplify them.
3396
  void FillPlaceholders(FoldAddrToValueMapping &Map,
3397
                        SmallVectorImpl<Value *> &TraverseOrder,
3398
5.40k
                        SimplificationTracker &ST) {
3399
11.0k
    while (!TraverseOrder.empty()) {
3400
5.68k
      Value *Current = TraverseOrder.pop_back_val();
3401
5.68k
      assert(Map.find(Current) != Map.end() && "No node to fill!!!");
3402
5.68k
      Value *V = Map[Current];
3403
5.68k
3404
5.68k
      if (SelectInst *Select = dyn_cast<SelectInst>(V)) {
3405
764
        // CurrentValue also must be Select.
3406
764
        auto *CurrentSelect = cast<SelectInst>(Current);
3407
764
        auto *TrueValue = CurrentSelect->getTrueValue();
3408
764
        assert(Map.find(TrueValue) != Map.end() && "No True Value!");
3409
764
        Select->setTrueValue(ST.Get(Map[TrueValue]));
3410
764
        auto *FalseValue = CurrentSelect->getFalseValue();
3411
764
        assert(Map.find(FalseValue) != Map.end() && "No False Value!");
3412
764
        Select->setFalseValue(ST.Get(Map[FalseValue]));
3413
4.92k
      } else {
3414
4.92k
        // Must be a Phi node then.
3415
4.92k
        PHINode *PHI = cast<PHINode>(V);
3416
4.92k
        auto *CurrentPhi = dyn_cast<PHINode>(Current);
3417
4.92k
        // Fill the Phi node with values from predecessors.
3418
11.6k
        for (auto B : predecessors(PHI->getParent())) {
3419
11.6k
          Value *PV = CurrentPhi->getIncomingValueForBlock(B);
3420
11.6k
          assert(Map.find(PV) != Map.end() && "No predecessor Value!");
3421
11.6k
          PHI->addIncoming(ST.Get(Map[PV]), B);
3422
11.6k
        }
3423
4.92k
      }
3424
5.68k
      Map[Current] = ST.Simplify(V);
3425
5.68k
    }
3426
5.40k
  }
3427
3428
  /// Starting from original value recursively iterates over def-use chain up to
3429
  /// known ending values represented in a map. For each traversed phi/select
3430
  /// inserts a placeholder Phi or Select.
3431
  /// Reports all new created Phi/Select nodes by adding them to set.
3432
  /// Also reports and order in what values have been traversed.
3433
  void InsertPlaceholders(FoldAddrToValueMapping &Map,
3434
                          SmallVectorImpl<Value *> &TraverseOrder,
3435
5.40k
                          SimplificationTracker &ST) {
3436
5.40k
    SmallVector<Value *, 32> Worklist;
3437
5.40k
    assert((isa<PHINode>(Original) || isa<SelectInst>(Original)) &&
3438
5.40k
           "Address must be a Phi or Select node");
3439
5.40k
    auto *Dummy = UndefValue::get(CommonType);
3440
5.40k
    Worklist.push_back(Original);
3441
23.9k
    while (!Worklist.empty()) {
3442
18.5k
      Value *Current = Worklist.pop_back_val();
3443
18.5k
      // if it is already visited or it is an ending value then skip it.
3444
18.5k
      if (Map.find(Current) != Map.end())
3445
12.8k
        continue;
3446
5.68k
      TraverseOrder.push_back(Current);
3447
5.68k
3448
5.68k
      // CurrentValue must be a Phi node or select. All others must be covered
3449
5.68k
      // by anchors.
3450
5.68k
      if (SelectInst *CurrentSelect = dyn_cast<SelectInst>(Current)) {
3451
764
        // Is it OK to get metadata from OrigSelect?!
3452
764
        // Create a Select placeholder with dummy value.
3453
764
        SelectInst *Select = SelectInst::Create(
3454
764
            CurrentSelect->getCondition(), Dummy, Dummy,
3455
764
            CurrentSelect->getName(), CurrentSelect, CurrentSelect);
3456
764
        Map[Current] = Select;
3457
764
        ST.insertNewSelect(Select);
3458
764
        // We are interested in True and False values.
3459
764
        Worklist.push_back(CurrentSelect->getTrueValue());
3460
764
        Worklist.push_back(CurrentSelect->getFalseValue());
3461
4.92k
      } else {
3462
4.92k
        // It must be a Phi node then.
3463
4.92k
        PHINode *CurrentPhi = cast<PHINode>(Current);
3464
4.92k
        unsigned PredCount = CurrentPhi->getNumIncomingValues();
3465
4.92k
        PHINode *PHI =
3466
4.92k
            PHINode::Create(CommonType, PredCount, "sunk_phi", CurrentPhi);
3467
4.92k
        Map[Current] = PHI;
3468
4.92k
        ST.insertNewPhi(PHI);
3469
4.92k
        for (Value *P : CurrentPhi->incoming_values())
3470
11.6k
          Worklist.push_back(P);
3471
4.92k
      }
3472
5.68k
    }
3473
5.40k
  }
3474
3475
5.41k
  bool addrModeCombiningAllowed() {
3476
5.41k
    if (DisableComplexAddrModes)
3477
0
      return false;
3478
5.41k
    switch (DifferentField) {
3479
5.41k
    default:
3480
0
      return false;
3481
5.41k
    case ExtAddrMode::BaseRegField:
3482
3.41k
      return AddrSinkCombineBaseReg;
3483
5.41k
    case ExtAddrMode::BaseGVField:
3484
0
      return AddrSinkCombineBaseGV;
3485
5.41k
    case ExtAddrMode::BaseOffsField:
3486
1.78k
      return AddrSinkCombineBaseOffs;
3487
5.41k
    case ExtAddrMode::ScaledRegField:
3488
215
      return AddrSinkCombineScaledReg;
3489
5.41k
    }
3490
5.41k
  }
3491
};
3492
} // end anonymous namespace
3493
3494
/// Try adding ScaleReg*Scale to the current addressing mode.
3495
/// Return true and update AddrMode if this addr mode is legal for the target,
3496
/// false if not.
3497
bool AddressingModeMatcher::matchScaledValue(Value *ScaleReg, int64_t Scale,
3498
1.36M
                                             unsigned Depth) {
3499
1.36M
  // If Scale is 1, then this is the same as adding ScaleReg to the addressing
3500
1.36M
  // mode.  Just process that directly.
3501
1.36M
  if (Scale == 1)
3502
457k
    return matchAddr(ScaleReg, Depth);
3503
902k
3504
902k
  // If the scale is 0, it takes nothing to add this.
3505
902k
  if (Scale == 0)
3506
4
    return true;
3507
902k
3508
902k
  // If we already have a scale of this value, we can add to it, otherwise, we
3509
902k
  // need an available scale field.
3510
902k
  if (AddrMode.Scale != 0 && 
AddrMode.ScaledReg != ScaleReg25.2k
)
3511
21.6k
    return false;
3512
881k
3513
881k
  ExtAddrMode TestAddrMode = AddrMode;
3514
881k
3515
881k
  // Add scale to turn X*4+X*3 -> X*7.  This could also do things like
3516
881k
  // [A+B + A*7] -> [B+A*8].
3517
881k
  TestAddrMode.Scale += Scale;
3518
881k
  TestAddrMode.ScaledReg = ScaleReg;
3519
881k
3520
881k
  // If the new address isn't legal, bail out.
3521
881k
  if (!TLI.isLegalAddressingMode(DL, TestAddrMode, AccessTy, AddrSpace))
3522
496k
    return false;
3523
384k
3524
384k
  // It was legal, so commit it.
3525
384k
  AddrMode = TestAddrMode;
3526
384k
3527
384k
  // Okay, we decided that we can add ScaleReg+Scale to AddrMode.  Check now
3528
384k
  // to see if ScaleReg is actually X+C.  If so, we can turn this into adding
3529
384k
  // X*Scale + C*Scale to addr mode.
3530
384k
  ConstantInt *CI = nullptr; Value *AddLHS = nullptr;
3531
384k
  if (isa<Instruction>(ScaleReg) &&  // not a constant expr.
3532
384k
      
match(ScaleReg, m_Add(m_Value(AddLHS), m_ConstantInt(CI)))382k
) {
3533
19.4k
    TestAddrMode.InBounds = false;
3534
19.4k
    TestAddrMode.ScaledReg = AddLHS;
3535
19.4k
    TestAddrMode.BaseOffs += CI->getSExtValue()*TestAddrMode.Scale;
3536
19.4k
3537
19.4k
    // If this addressing mode is legal, commit it and remember that we folded
3538
19.4k
    // this instruction.
3539
19.4k
    if (TLI.isLegalAddressingMode(DL, TestAddrMode, AccessTy, AddrSpace)) {
3540
5.97k
      AddrModeInsts.push_back(cast<Instruction>(ScaleReg));
3541
5.97k
      AddrMode = TestAddrMode;
3542
5.97k
      return true;
3543
5.97k
    }
3544
378k
  }
3545
378k
3546
378k
  // Otherwise, not (x+c)*scale, just return what we have.
3547
378k
  return true;
3548
378k
}
3549
3550
/// This is a little filter, which returns true if an addressing computation
3551
/// involving I might be folded into a load/store accessing it.
3552
/// This doesn't need to be perfect, but needs to accept at least
3553
/// the set of instructions that MatchOperationAddr can.
3554
1.38M
static bool MightBeFoldableInst(Instruction *I) {
3555
1.38M
  switch (I->getOpcode()) {
3556
1.38M
  case Instruction::BitCast:
3557
602k
  case Instruction::AddrSpaceCast:
3558
602k
    // Don't touch identity bitcasts.
3559
602k
    if (I->getType() == I->getOperand(0)->getType())
3560
23
      return false;
3561
601k
    return I->getType()->isIntOrPtrTy();
3562
601k
  case Instruction::PtrToInt:
3563
2.29k
    // PtrToInt is always a noop, as we know that the int type is pointer sized.
3564
2.29k
    return true;
3565
601k
  case Instruction::IntToPtr:
3566
5.11k
    // We know the input is intptr_t, so this is foldable.
3567
5.11k
    return true;
3568
601k
  case Instruction::Add:
3569
5.71k
    return true;
3570
601k
  case Instruction::Mul:
3571
791
  case Instruction::Shl:
3572
791
    // Can only handle X*C and X << C.
3573
791
    return isa<ConstantInt>(I->getOperand(1));
3574
734k
  case Instruction::GetElementPtr:
3575
734k
    return true;
3576
38.1k
  default:
3577
38.1k
    return false;
3578
1.38M
  }
3579
1.38M
}
3580
3581
/// Check whether or not \p Val is a legal instruction for \p TLI.
3582
/// \note \p Val is assumed to be the product of some type promotion.
3583
/// Therefore if \p Val has an undefined state in \p TLI, this is assumed
3584
/// to be legal, as the non-promoted value would have had the same state.
3585
static bool isPromotedInstructionLegal(const TargetLowering &TLI,
3586
101k
                                       const DataLayout &DL, Value *Val) {
3587
101k
  Instruction *PromotedInst = dyn_cast<Instruction>(Val);
3588
101k
  if (!PromotedInst)
3589
1
    return false;
3590
101k
  int ISDOpcode = TLI.InstructionOpcodeToISD(PromotedInst->getOpcode());
3591
101k
  // If the ISDOpcode is undefined, it was undefined before the promotion.
3592
101k
  if (!ISDOpcode)
3593
0
    return true;
3594
101k
  // Otherwise, check if the promoted instruction is legal or not.
3595
101k
  return TLI.isOperationLegalOrCustom(
3596
101k
      ISDOpcode, TLI.getValueType(DL, PromotedInst->getType()));
3597
101k
}
3598
3599
namespace {
3600
3601
/// Hepler class to perform type promotion.
3602
class TypePromotionHelper {
3603
  /// Utility function to add a promoted instruction \p ExtOpnd to
3604
  /// \p PromotedInsts and record the type of extension we have seen.
3605
  static void addPromotedInst(InstrToOrigTy &PromotedInsts,
3606
                              Instruction *ExtOpnd,
3607
116k
                              bool IsSExt) {
3608
116k
    ExtType ExtTy = IsSExt ? 
SignExtension78.7k
:
ZeroExtension37.4k
;
3609
116k
    InstrToOrigTy::iterator It = PromotedInsts.find(ExtOpnd);
3610
116k
    if (It != PromotedInsts.end()) {
3611
68.1k
      // If the new extension is same as original, the information in
3612
68.1k
      // PromotedInsts[ExtOpnd] is still correct.
3613
68.1k
      if (It->second.getInt() == ExtTy)
3614
68.1k
        return;
3615
53
3616
53
      // Now the new extension is different from old extension, we make
3617
53
      // the type information invalid by setting extension type to
3618
53
      // BothExtension.
3619
53
      ExtTy = BothExtension;
3620
53
    }
3621
116k
    PromotedInsts[ExtOpnd] = TypeIsSExt(ExtOpnd->getType(), ExtTy);
3622
48.0k
  }
3623
3624
  /// Utility function to query the original type of instruction \p Opnd
3625
  /// with a matched extension type. If the extension doesn't match, we
3626
  /// cannot use the information we had on the original type.
3627
  /// BothExtension doesn't match any extension type.
3628
  static const Type *getOrigType(const InstrToOrigTy &PromotedInsts,
3629
                                 Instruction *Opnd,
3630
53.0k
                                 bool IsSExt) {
3631
53.0k
    ExtType ExtTy = IsSExt ? 
SignExtension42.2k
:
ZeroExtension10.7k
;
3632
53.0k
    InstrToOrigTy::const_iterator It = PromotedInsts.find(Opnd);
3633
53.0k
    if (It != PromotedInsts.end() && 
It->second.getInt() == ExtTy5.19k
)
3634
4.31k
      return It->second.getPointer();
3635
48.6k
    return nullptr;
3636
48.6k
  }
3637
3638
  /// Utility function to check whether or not a sign or zero extension
3639
  /// of \p Inst with \p ConsideredExtType can be moved through \p Inst by
3640
  /// either using the operands of \p Inst or promoting \p Inst.
3641
  /// The type of the extension is defined by \p IsSExt.
3642
  /// In other words, check if:
3643
  /// ext (Ty Inst opnd1 opnd2 ... opndN) to ConsideredExtType.
3644
  /// #1 Promotion applies:
3645
  /// ConsideredExtType Inst (ext opnd1 to ConsideredExtType, ...).
3646
  /// #2 Operand reuses:
3647
  /// ext opnd1 to ConsideredExtType.
3648
  /// \p PromotedInsts maps the instructions to their type before promotion.
3649
  static bool canGetThrough(const Instruction *Inst, Type *ConsideredExtType,
3650
                            const InstrToOrigTy &PromotedInsts, bool IsSExt);
3651
3652
  /// Utility function to determine if \p OpIdx should be promoted when
3653
  /// promoting \p Inst.
3654
232k
  static bool shouldExtOperand(const Instruction *Inst, int OpIdx) {
3655
232k
    return !(isa<SelectInst>(Inst) && 
OpIdx == 00
);
3656
232k
  }
3657
3658
  /// Utility function to promote the operand of \p Ext when this
3659
  /// operand is a promotable trunc or sext or zext.
3660
  /// \p PromotedInsts maps the instructions to their type before promotion.
3661
  /// \p CreatedInstsCost[out] contains the cost of all instructions
3662
  /// created to promote the operand of Ext.
3663
  /// Newly added extensions are inserted in \p Exts.
3664
  /// Newly added truncates are inserted in \p Truncs.
3665
  /// Should never be called directly.
3666
  /// \return The promoted value which is used instead of Ext.
3667
  static Value *promoteOperandForTruncAndAnyExt(
3668
      Instruction *Ext, TypePromotionTransaction &TPT,
3669
      InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
3670
      SmallVectorImpl<Instruction *> *Exts,
3671
      SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI);
3672
3673
  /// Utility function to promote the operand of \p Ext when this
3674
  /// operand is promotable and is not a supported trunc or sext.
3675
  /// \p PromotedInsts maps the instructions to their type before promotion.
3676
  /// \p CreatedInstsCost[out] contains the cost of all the instructions
3677
  /// created to promote the operand of Ext.
3678
  /// Newly added extensions are inserted in \p Exts.
3679
  /// Newly added truncates are inserted in \p Truncs.
3680
  /// Should never be called directly.
3681
  /// \return The promoted value which is used instead of Ext.
3682
  static Value *promoteOperandForOther(Instruction *Ext,
3683
                                       TypePromotionTransaction &TPT,
3684
                                       InstrToOrigTy &PromotedInsts,
3685
                                       unsigned &CreatedInstsCost,
3686
                                       SmallVectorImpl<Instruction *> *Exts,
3687
                                       SmallVectorImpl<Instruction *> *Truncs,
3688
                                       const TargetLowering &TLI, bool IsSExt);
3689
3690
  /// \see promoteOperandForOther.
3691
  static Value *signExtendOperandForOther(
3692
      Instruction *Ext, TypePromotionTransaction &TPT,
3693
      InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
3694
      SmallVectorImpl<Instruction *> *Exts,
3695
78.7k
      SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) {
3696
78.7k
    return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInstsCost,
3697
78.7k
                                  Exts, Truncs, TLI, true);
3698
78.7k
  }
3699
3700
  /// \see promoteOperandForOther.
3701
  static Value *zeroExtendOperandForOther(
3702
      Instruction *Ext, TypePromotionTransaction &TPT,
3703
      InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
3704
      SmallVectorImpl<Instruction *> *Exts,
3705
37.4k
      SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) {
3706
37.4k
    return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInstsCost,
3707
37.4k
                                  Exts, Truncs, TLI, false);
3708
37.4k
  }
3709
3710
public:
3711
  /// Type for the utility function that promotes the operand of Ext.
3712
  using Action = Value *(*)(Instruction *Ext, TypePromotionTransaction &TPT,
3713
                            InstrToOrigTy &PromotedInsts,
3714
                            unsigned &CreatedInstsCost,
3715
                            SmallVectorImpl<Instruction *> *Exts,
3716
                            SmallVectorImpl<Instruction *> *Truncs,
3717
                            const TargetLowering &TLI);
3718
3719
  /// Given a sign/zero extend instruction \p Ext, return the appropriate
3720
  /// action to promote the operand of \p Ext instead of using Ext.
3721
  /// \return NULL if no promotable action is possible with the current
3722
  /// sign extension.
3723
  /// \p InsertedInsts keeps track of all the instructions inserted by the
3724
  /// other CodeGenPrepare optimizations. This information is important
3725
  /// because we do not want to promote these instructions as CodeGenPrepare
3726
  /// will reinsert them later. Thus creating an infinite loop: create/remove.
3727
  /// \p PromotedInsts maps the instructions to their type before promotion.
3728
  static Action getAction(Instruction *Ext, const SetOfInstrs &InsertedInsts,
3729
                          const TargetLowering &TLI,
3730
                          const InstrToOrigTy &PromotedInsts);
3731
};
3732
3733
} // end anonymous namespace
3734
3735
bool TypePromotionHelper::canGetThrough(const Instruction *Inst,
3736
                                        Type *ConsideredExtType,
3737
                                        const InstrToOrigTy &PromotedInsts,
3738
456k
                                        bool IsSExt) {
3739
456k
  // The promotion helper does not know how to deal with vector types yet.
3740
456k
  // To be able to fix that, we would need to fix the places where we
3741
456k
  // statically extend, e.g., constants and such.
3742
456k
  if (Inst->getType()->isVectorTy())
3743
10.7k
    return false;
3744
445k
3745
445k
  // We can always get through zext.
3746
445k
  if (isa<ZExtInst>(Inst))
3747
4.36k
    return true;
3748
441k
3749
441k
  // sext(sext) is ok too.
3750
441k
  if (IsSExt && 
isa<SExtInst>(Inst)252k
)
3751
614
    return true;
3752
440k
3753
440k
  // We can get through binary operator, if it is legal. In other words, the
3754
440k
  // binary operator must have a nuw or nsw flag.
3755
440k
  const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Inst);
3756
440k
  if (BinOp && 
isa<OverflowingBinaryOperator>(BinOp)200k
&&
3757
440k
      
(144k
(144k
!IsSExt144k
&&
BinOp->hasNoUnsignedWrap()47.0k
) ||
3758
144k
       
(136k
IsSExt136k
&&
BinOp->hasNoSignedWrap()97.0k
)))
3759
84.5k
    return true;
3760
356k
3761
356k
  // ext(and(opnd, cst)) --> and(ext(opnd), ext(cst))
3762
356k
  if ((Inst->getOpcode() == Instruction::And ||
3763
356k
       
Inst->getOpcode() == Instruction::Or333k
))
3764
25.2k
    return true;
3765
331k
3766
331k
  // ext(xor(opnd, cst)) --> xor(ext(opnd), ext(cst))
3767
331k
  if (Inst->getOpcode() == Instruction::Xor) {
3768
5.02k
    const ConstantInt *Cst = dyn_cast<ConstantInt>(Inst->getOperand(1));
3769
5.02k
    // Make sure it is not a NOT.
3770
5.02k
    if (Cst && 
!Cst->getValue().isAllOnesValue()3.06k
)
3771
655
      return true;
3772
330k
  }
3773
330k
3774
330k
  // zext(shrl(opnd, cst)) --> shrl(zext(opnd), zext(cst))
3775
330k
  // It may change a poisoned value into a regular value, like
3776
330k
  //     zext i32 (shrl i8 %val, 12)  -->  shrl i32 (zext i8 %val), 12
3777
330k
  //          poisoned value                    regular value
3778
330k
  // It should be OK since undef covers valid value.
3779
330k
  if (Inst->getOpcode() == Instruction::LShr && 
!IsSExt5.78k
)
3780
5.61k
    return true;
3781
324k
3782
324k
  // and(ext(shl(opnd, cst)), cst) --> and(shl(ext(opnd), ext(cst)), cst)
3783
324k
  // It may change a poisoned value into a regular value, like
3784
324k
  //     zext i32 (shl i8 %val, 12)  -->  shl i32 (zext i8 %val), 12
3785
324k
  //          poisoned value                    regular value
3786
324k
  // It should be OK since undef covers valid value.
3787
324k
  if (Inst->getOpcode() == Instruction::Shl && 
Inst->hasOneUse()4.47k
) {
3788
2.84k
    const Instruction *ExtInst =
3789
2.84k
        dyn_cast<const Instruction>(*Inst->user_begin());
3790
2.84k
    if (ExtInst->hasOneUse()) {
3791
2.43k
      const Instruction *AndInst =
3792
2.43k
          dyn_cast<const Instruction>(*ExtInst->user_begin());
3793
2.43k
      if (AndInst && AndInst->getOpcode() == Instruction::And) {
3794
289
        const ConstantInt *Cst = dyn_cast<ConstantInt>(AndInst->getOperand(1));
3795
289
        if (Cst &&
3796
289
            
Cst->getValue().isIntN(Inst->getType()->getIntegerBitWidth())204
)
3797
200
          return true;
3798
324k
      }
3799
2.43k
    }
3800
2.84k
  }
3801
324k
3802
324k
  // Check if we can do the following simplification.
3803
324k
  // ext(trunc(opnd)) --> ext(opnd)
3804
324k
  if (!isa<TruncInst>(Inst))
3805
270k
    return false;
3806
53.6k
3807
53.6k
  Value *OpndVal = Inst->getOperand(0);
3808
53.6k
  // Check if we can use this operand in the extension.
3809
53.6k
  // If the type is larger than the result type of the extension, we cannot.
3810
53.6k
  if (!OpndVal->getType()->isIntegerTy() ||
3811
53.6k
      OpndVal->getType()->getIntegerBitWidth() >
3812
53.6k
          ConsideredExtType->getIntegerBitWidth())
3813
530
    return false;
3814
53.1k
3815
53.1k
  // If the operand of the truncate is not an instruction, we will not have
3816
53.1k
  // any information on the dropped bits.
3817
53.1k
  // (Actually we could for constant but it is not worth the extra logic).
3818
53.1k
  Instruction *Opnd = dyn_cast<Instruction>(OpndVal);
3819
53.1k
  if (!Opnd)
3820
151
    return false;
3821
53.0k
3822
53.0k
  // Check if the source of the type is narrow enough.
3823
53.0k
  // I.e., check that trunc just drops extended bits of the same kind of
3824
53.0k
  // the extension.
3825
53.0k
  // #1 get the type of the operand and check the kind of the extended bits.
3826
53.0k
  const Type *OpndType = getOrigType(PromotedInsts, Opnd, IsSExt);
3827
53.0k
  if (OpndType)
3828
4.31k
    ;
3829
48.6k
  else if ((IsSExt && 
isa<SExtInst>(Opnd)39.1k
) ||
(16.2k
!IsSExt16.2k
&&
isa<ZExtInst>(Opnd)9.58k
))
3830
34.5k
    OpndType = Opnd->getOperand(0)->getType();
3831
14.1k
  else
3832
14.1k
    return false;
3833
38.8k
3834
38.8k
  // #2 check that the truncate just drops extended bits.
3835
38.8k
  return Inst->getType()->getIntegerBitWidth() >=
3836
38.8k
         OpndType->getIntegerBitWidth();
3837
38.8k
}
3838
3839
TypePromotionHelper::Action TypePromotionHelper::getAction(
3840
    Instruction *Ext, const SetOfInstrs &InsertedInsts,
3841
577k
    const TargetLowering &TLI, const InstrToOrigTy &PromotedInsts) {
3842
577k
  assert((isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) &&
3843
577k
         "Unexpected instruction type");
3844
577k
  Instruction *ExtOpnd = dyn_cast<Instruction>(Ext->getOperand(0));
3845
577k
  Type *ExtTy = Ext->getType();
3846
577k
  bool IsSExt = isa<SExtInst>(Ext);
3847
577k
  // If the operand of the extension is not an instruction, we cannot
3848
577k
  // get through.
3849
577k
  // If it, check we can get through.
3850
577k
  if (!ExtOpnd || 
!canGetThrough(ExtOpnd, ExtTy, PromotedInsts, IsSExt)456k
)
3851
417k
    return nullptr;
3852
160k
3853
160k
  // Do not promote if the operand has been added by codegenprepare.
3854
160k
  // Otherwise, it means we are undoing an optimization that is likely to be
3855
160k
  // redone, thus causing potential infinite loop.
3856
160k
  if (isa<TruncInst>(ExtOpnd) && 
InsertedInsts.count(ExtOpnd)38.8k
)
3857
34.5k
    return nullptr;
3858
125k
3859
125k
  // SExt or Trunc instructions.
3860
125k
  // Return the related handler.
3861
125k
  if (isa<SExtInst>(ExtOpnd) || 
isa<TruncInst>(ExtOpnd)124k
||
3862
125k
      
isa<ZExtInst>(ExtOpnd)120k
)
3863
9.29k
    return promoteOperandForTruncAndAnyExt;
3864
116k
3865
116k
  // Regular instruction.
3866
116k
  // Abort early if we will have to insert non-free instructions.
3867
116k
  if (!ExtOpnd->hasOneUse() && 
!TLI.isTruncateFree(ExtTy, ExtOpnd->getType())23.0k
)
3868
0
    return nullptr;
3869
116k
  return IsSExt ? 
signExtendOperandForOther78.7k
:
zeroExtendOperandForOther37.4k
;
3870
116k
}
3871
3872
Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt(
3873
    Instruction *SExt, TypePromotionTransaction &TPT,
3874
    InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
3875
    SmallVectorImpl<Instruction *> *Exts,
3876
9.29k
    SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) {
3877
9.29k
  // By construction, the operand of SExt is an instruction. Otherwise we cannot
3878
9.29k
  // get through it and this method should not be called.
3879
9.29k
  Instruction *SExtOpnd = cast<Instruction>(SExt->getOperand(0));
3880
9.29k
  Value *ExtVal = SExt;
3881
9.29k
  bool HasMergedNonFreeExt = false;
3882
9.29k
  if (isa<ZExtInst>(SExtOpnd)) {
3883
4.36k
    // Replace s|zext(zext(opnd))
3884
4.36k
    // => zext(opnd).
3885
4.36k
    HasMergedNonFreeExt = !TLI.isExtFree(SExtOpnd);
3886
4.36k
    Value *ZExt =
3887
4.36k
        TPT.createZExt(SExt, SExtOpnd->getOperand(0), SExt->getType());
3888
4.36k
    TPT.replaceAllUsesWith(SExt, ZExt);
3889
4.36k
    TPT.eraseInstruction(SExt);
3890
4.36k
    ExtVal = ZExt;
3891
4.93k
  } else {
3892
4.93k
    // Replace z|sext(trunc(opnd)) or sext(sext(opnd))
3893
4.93k
    // => z|sext(opnd).
3894
4.93k
    TPT.setOperand(SExt, 0, SExtOpnd->getOperand(0));
3895
4.93k
  }
3896
9.29k
  CreatedInstsCost = 0;
3897
9.29k
3898
9.29k
  // Remove dead code.
3899
9.29k
  if (SExtOpnd->use_empty())
3900
5.26k
    TPT.eraseInstruction(SExtOpnd);
3901
9.29k
3902
9.29k
  // Check if the extension is still needed.
3903
9.29k
  Instruction *ExtInst = dyn_cast<Instruction>(ExtVal);
3904
9.29k
  if (!ExtInst || 
ExtInst->getType() != ExtInst->getOperand(0)->getType()9.29k
) {
3905
5.00k
    if (ExtInst) {
3906
4.99k
      if (Exts)
3907
4.87k
        Exts->push_back(ExtInst);
3908
4.99k
      CreatedInstsCost = !TLI.isExtFree(ExtInst) && 
!HasMergedNonFreeExt4.68k
;
3909
4.99k
    }
3910
5.00k
    return ExtVal;
3911
5.00k
  }
3912
4.29k
3913
4.29k
  // At this point we have: ext ty opnd to ty.
3914
4.29k
  // Reassign the uses of ExtInst to the opnd and remove ExtInst.
3915
4.29k
  Value *NextVal = ExtInst->getOperand(0);
3916
4.29k
  TPT.eraseInstruction(ExtInst, NextVal);
3917
4.29k
  return NextVal;
3918
4.29k
}
3919
3920
Value *TypePromotionHelper::promoteOperandForOther(
3921
    Instruction *Ext, TypePromotionTransaction &TPT,
3922
    InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
3923
    SmallVectorImpl<Instruction *> *Exts,
3924
    SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI,
3925
116k
    bool IsSExt) {
3926
116k
  // By construction, the operand of Ext is an instruction. Otherwise we cannot
3927
116k
  // get through it and this method should not be called.
3928
116k
  Instruction *ExtOpnd = cast<Instruction>(Ext->getOperand(0));
3929
116k
  CreatedInstsCost = 0;
3930
116k
  if (!ExtOpnd->hasOneUse()) {
3931
23.0k
    // ExtOpnd will be promoted.
3932
23.0k
    // All its uses, but Ext, will need to use a truncated value of the
3933
23.0k
    // promoted version.
3934
23.0k
    // Create the truncate now.
3935
23.0k
    Value *Trunc = TPT.createTrunc(Ext, ExtOpnd->getType());
3936
23.0k
    if (Instruction *ITrunc = dyn_cast<Instruction>(Trunc)) {
3937
23.0k
      // Insert it just after the definition.
3938
23.0k
      ITrunc->moveAfter(ExtOpnd);
3939
23.0k
      if (Truncs)
3940
0
        Truncs->push_back(ITrunc);
3941
23.0k
    }
3942
23.0k
3943
23.0k
    TPT.replaceAllUsesWith(ExtOpnd, Trunc);
3944
23.0k
    // Restore the operand of Ext (which has been replaced by the previous call
3945
23.0k
    // to replaceAllUsesWith) to avoid creating a cycle trunc <-> sext.
3946
23.0k
    TPT.setOperand(Ext, 0, ExtOpnd);
3947
23.0k
  }
3948
116k
3949
116k
  // Get through the Instruction:
3950
116k
  // 1. Update its type.
3951
116k
  // 2. Replace the uses of Ext by Inst.
3952
116k
  // 3. Extend each operand that needs to be extended.
3953
116k
3954
116k
  // Remember the original type of the instruction before promotion.
3955
116k
  // This is useful to know that the high bits are sign extended bits.
3956
116k
  addPromotedInst(PromotedInsts, ExtOpnd, IsSExt);
3957
116k
  // Step #1.
3958
116k
  TPT.mutateType(ExtOpnd, Ext->getType());
3959
116k
  // Step #2.
3960
116k
  TPT.replaceAllUsesWith(Ext, ExtOpnd);
3961
116k
  // Step #3.
3962
116k
  Instruction *ExtForOpnd = Ext;
3963
116k
3964
116k
  LLVM_DEBUG(dbgs() << "Propagate Ext to operands\n");
3965
348k
  for (int OpIdx = 0, EndOpIdx = ExtOpnd->getNumOperands(); OpIdx != EndOpIdx;
3966
232k
       ++OpIdx) {
3967
232k
    LLVM_DEBUG(dbgs() << "Operand:\n" << *(ExtOpnd->getOperand(OpIdx)) << '\n');
3968
232k
    if (ExtOpnd->getOperand(OpIdx)->getType() == Ext->getType() ||
3969
232k
        !shouldExtOperand(ExtOpnd, OpIdx)) {
3970
0
      LLVM_DEBUG(dbgs() << "No need to propagate\n");
3971
0
      continue;
3972
0
    }
3973
232k
    // Check if we can statically extend the operand.
3974
232k
    Value *Opnd = ExtOpnd->getOperand(OpIdx);
3975
232k
    if (const ConstantInt *Cst = dyn_cast<ConstantInt>(Opnd)) {
3976
45.6k
      LLVM_DEBUG(dbgs() << "Statically extend\n");
3977
45.6k
      unsigned BitWidth = Ext->getType()->getIntegerBitWidth();
3978
45.6k
      APInt CstVal = IsSExt ? 
Cst->getValue().sext(BitWidth)16.1k
3979
45.6k
                            : 
Cst->getValue().zext(BitWidth)29.5k
;
3980
45.6k
      TPT.setOperand(ExtOpnd, OpIdx, ConstantInt::get(Ext->getType(), CstVal));
3981
45.6k
      continue;
3982
45.6k
    }
3983
186k
    // UndefValue are typed, so we have to statically sign extend them.
3984
186k
    if (isa<UndefValue>(Opnd)) {
3985
0
      LLVM_DEBUG(dbgs() << "Statically extend\n");
3986
0
      TPT.setOperand(ExtOpnd, OpIdx, UndefValue::get(Ext->getType()));
3987
0
      continue;
3988
0
    }
3989
186k
3990
186k
    // Otherwise we have to explicitly sign extend the operand.
3991
186k
    // Check if Ext was reused to extend an operand.
3992
186k
    if (!ExtForOpnd) {
3993
70.4k
      // If yes, create a new one.
3994
70.4k
      LLVM_DEBUG(dbgs() << "More operands to ext\n");
3995
70.4k
      Value *ValForExtOpnd = IsSExt ? 
TPT.createSExt(Ext, Opnd, Ext->getType())62.6k
3996
70.4k
        : 
TPT.createZExt(Ext, Opnd, Ext->getType())7.84k
;
3997
70.4k
      if (!isa<Instruction>(ValForExtOpnd)) {
3998
6
        TPT.setOperand(ExtOpnd, OpIdx, ValForExtOpnd);
3999
6
        continue;
4000
6
      }
4001
70.4k
      ExtForOpnd = cast<Instruction>(ValForExtOpnd);
4002
70.4k
    }
4003
186k
    
if (186k
Exts186k
)
4004
165k
      Exts->push_back(ExtForOpnd);
4005
186k
    TPT.setOperand(ExtForOpnd, 0, Opnd);
4006
186k
4007
186k
    // Move the sign extension before the insertion point.
4008
186k
    TPT.moveBefore(ExtForOpnd, ExtOpnd);
4009
186k
    TPT.setOperand(ExtOpnd, OpIdx, ExtForOpnd);
4010
186k
    CreatedInstsCost += !TLI.isExtFree(ExtForOpnd);
4011
186k
    // If more sext are required, new instructions will have to be created.
4012
186k
    ExtForOpnd = nullptr;
4013
186k
  }
4014
116k
  if (ExtForOpnd == Ext) {
4015
0
    LLVM_DEBUG(dbgs() << "Extension is useless now\n");
4016
0
    TPT.eraseInstruction(Ext);
4017
0
  }
4018
116k
  return ExtOpnd;
4019
116k
}
4020
4021
/// Check whether or not promoting an instruction to a wider type is profitable.
4022
/// \p NewCost gives the cost of extension instructions created by the
4023
/// promotion.
4024
/// \p OldCost gives the cost of extension instructions before the promotion
4025
/// plus the number of instructions that have been
4026
/// matched in the addressing mode the promotion.
4027
/// \p PromotedOperand is the value that has been promoted.
4028
/// \return True if the promotion is profitable, false otherwise.
4029
bool AddressingModeMatcher::isPromotionProfitable(
4030
6.25k
    unsigned NewCost, unsigned OldCost, Value *PromotedOperand) const {
4031
6.25k
  LLVM_DEBUG(dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCost
4032
6.25k
                    << '\n');
4033
6.25k
  // The cost of the new extensions is greater than the cost of the
4034
6.25k
  // old extension plus what we folded.
4035
6.25k
  // This is not profitable.
4036
6.25k
  if (NewCost > OldCost)
4037
5.18k
    return false;
4038
1.06k
  if (NewCost < OldCost)
4039
334
    return true;
4040
735
  // The promotion is neutral but it may help folding the sign extension in
4041
735
  // loads for instance.
4042
735
  // Check that we did not create an illegal instruction.
4043
735
  return isPromotedInstructionLegal(TLI, DL, PromotedOperand);
4044
735
}
4045
4046
/// Given an instruction or constant expr, see if we can fold the operation
4047
/// into the addressing mode. If so, update the addressing mode and return
4048
/// true, otherwise return false without modifying AddrMode.
4049
/// If \p MovedAway is not NULL, it contains the information of whether or
4050
/// not AddrInst has to be folded into the addressing mode on success.
4051
/// If \p MovedAway == true, \p AddrInst will not be part of the addressing
4052
/// because it has been moved away.
4053
/// Thus AddrInst must not be added in the matched instructions.
4054
/// This state can happen when AddrInst is a sext, since it may be moved away.
4055
/// Therefore, AddrInst may not be valid when MovedAway is true and it must
4056
/// not be referenced anymore.
4057
bool AddressingModeMatcher::matchOperationAddr(User *AddrInst, unsigned Opcode,
4058
                                               unsigned Depth,
4059
17.3M
                                               bool *MovedAway) {
4060
17.3M
  // Avoid exponential behavior on extremely deep expression trees.
4061
17.3M
  if (Depth >= 5) 
return false2.99k
;
4062
17.3M
4063
17.3M
  // By default, all matched instructions stay in place.
4064
17.3M
  if (MovedAway)
4065
16.9M
    *MovedAway = false;
4066
17.3M
4067
17.3M
  switch (Opcode) {
4068
17.3M
  case Instruction::PtrToInt:
4069
1.40k
    // PtrToInt is always a noop, as we know that the int type is pointer sized.
4070
1.40k
    return matchAddr(AddrInst->getOperand(0), Depth);
4071
17.3M
  case Instruction::IntToPtr: {
4072
80.3k
    auto AS = AddrInst->getType()->getPointerAddressSpace();
4073
80.3k
    auto PtrTy = MVT::getIntegerVT(DL.getPointerSizeInBits(AS));
4074
80.3k
    // This inttoptr is a no-op if the integer type is pointer sized.
4075
80.3k
    if (TLI.getValueType(DL, AddrInst->getOperand(0)->getType()) == PtrTy)
4076
80.2k
      return matchAddr(AddrInst->getOperand(0), Depth);
4077
71
    return false;
4078
71
  }
4079
4.39M
  case Instruction::BitCast:
4080
4.39M
    // BitCast is always a noop, and we can handle it as long as it is
4081
4.39M
    // int->int or pointer->pointer (we don't want int<->fp or something).
4082
4.39M
    if (AddrInst->getOperand(0)->getType()->isIntOrPtrTy() &&
4083
4.39M
        // Don't touch identity bitcasts.  These were probably put here by LSR,
4084
4.39M
        // and we don't want to mess around with them.  Assume it knows what it
4085
4.39M
        // is doing.
4086
4.39M
        
AddrInst->getOperand(0)->getType() != AddrInst->getType()4.39M
)
4087
4.37M
      return matchAddr(AddrInst->getOperand(0), Depth);
4088
13.0k
    return false;
4089
13.0k
  case Instruction::AddrSpaceCast: {
4090
315
    unsigned SrcAS
4091
315
      = AddrInst->getOperand(0)->getType()->getPointerAddressSpace();
4092
315
    unsigned DestAS = AddrInst->getType()->getPointerAddressSpace();
4093
315
    if (TLI.isNoopAddrSpaceCast(SrcAS, DestAS))
4094
104
      return matchAddr(AddrInst->getOperand(0), Depth);
4095
211
    return false;
4096
211
  }
4097
48.1k
  case Instruction::Add: {
4098
48.1k
    // Check to see if we can merge in the RHS then the LHS.  If so, we win.
4099
48.1k
    ExtAddrMode BackupAddrMode = AddrMode;
4100
48.1k
    unsigned OldSize = AddrModeInsts.size();
4101
48.1k
    // Start a transaction at this point.
4102
48.1k
    // The LHS may match but not the RHS.
4103
48.1k
    // Therefore, we need a higher level restoration point to undo partially
4104
48.1k
    // matched operation.
4105
48.1k
    TypePromotionTransaction::ConstRestorationPt LastKnownGood =
4106
48.1k
        TPT.getRestorationPoint();
4107
48.1k
4108
48.1k
    AddrMode.InBounds = false;
4109
48.1k
    if (matchAddr(AddrInst->getOperand(1), Depth+1) &&
4110
48.1k
        
matchAddr(AddrInst->getOperand(0), Depth+1)46.6k
)
4111
24.6k
      return true;
4112
23.5k
4113
23.5k
    // Restore the old addr mode info.
4114
23.5k
    AddrMode = BackupAddrMode;
4115
23.5k
    AddrModeInsts.resize(OldSize);
4116
23.5k
    TPT.rollback(LastKnownGood);
4117
23.5k
4118
23.5k
    // Otherwise this was over-aggressive.  Try merging in the LHS then the RHS.
4119
23.5k
    if (matchAddr(AddrInst->getOperand(0), Depth+1) &&
4120
23.5k
        
matchAddr(AddrInst->getOperand(1), Depth+1)12.4k
)
4121
39
      return true;
4122
23.5k
4123
23.5k
    // Otherwise we definitely can't merge the ADD in.
4124
23.5k
    AddrMode = BackupAddrMode;
4125
23.5k
    AddrModeInsts.resize(OldSize);
4126
23.5k
    TPT.rollback(LastKnownGood);
4127
23.5k
    break;
4128
23.5k
  }
4129
23.5k
  //case Instruction::Or:
4130
23.5k
  // TODO: We can handle "Or Val, Imm" iff this OR is equivalent to an ADD.
4131
23.5k
  //break;
4132
99.8k
  case Instruction::Mul:
4133
99.8k
  case Instruction::Shl: {
4134
99.8k
    // Can only handle X*C and X << C.
4135
99.8k
    AddrMode.InBounds = false;
4136
99.8k
    ConstantInt *RHS = dyn_cast<ConstantInt>(AddrInst->getOperand(1));
4137
99.8k
    if (!RHS || 
RHS->getBitWidth() > 6488.8k
)
4138
11.0k
      return false;
4139
88.8k
    int64_t Scale = RHS->getSExtValue();
4140
88.8k
    if (Opcode == Instruction::Shl)
4141
57.4k
      Scale = 1LL << Scale;
4142
88.8k
4143
88.8k
    return matchScaledValue(AddrInst->getOperand(0), Scale, Depth);
4144
88.8k
  }
4145
7.06M
  case Instruction::GetElementPtr: {
4146
7.06M
    // Scan the GEP.  We check it if it contains constant offsets and at most
4147
7.06M
    // one variable offset.
4148
7.06M
    int VariableOperand = -1;
4149
7.06M
    unsigned VariableScale = 0;
4150
7.06M
4151
7.06M
    int64_t ConstantOffset = 0;
4152
7.06M
    gep_type_iterator GTI = gep_type_begin(AddrInst);
4153
20.7M
    for (unsigned i = 1, e = AddrInst->getNumOperands(); i != e; 
++i, ++GTI13.6M
) {
4154
13.6M
      if (StructType *STy = GTI.getStructTypeOrNull()) {
4155
5.01M
        const StructLayout *SL = DL.getStructLayout(STy);
4156
5.01M
        unsigned Idx =
4157
5.01M
          cast<ConstantInt>(AddrInst->getOperand(i))->getZExtValue();
4158
5.01M
        ConstantOffset += SL->getElementOffset(Idx);
4159
8.66M
      } else {
4160
8.66M
        uint64_t TypeSize = DL.getTypeAllocSize(GTI.getIndexedType());
4161
8.66M
        if (ConstantInt *CI = dyn_cast<ConstantInt>(AddrInst->getOperand(i))) {
4162
7.73M
          const APInt &CVal = CI->getValue();
4163
7.73M
          if (CVal.getMinSignedBits() <= 64) {
4164
7.73M
            ConstantOffset += CVal.getSExtValue() * TypeSize;
4165
7.73M
            continue;
4166
7.73M
          }
4167
928k
        }
4168
928k
        if (TypeSize) {  // Scales of zero don't do anything.
4169
928k
          // We only allow one variable index at the moment.
4170
928k
          if (VariableOperand != -1)
4171
18.9k
            return false;
4172
909k
4173
909k
          // Remember the variable index.
4174
909k
          VariableOperand = i;
4175
909k
          VariableScale = TypeSize;
4176
909k
        }
4177
928k
      }
4178
13.6M
    }
4179
7.06M
4180
7.06M
    // A common case is for the GEP to only do a constant offset.  In this case,
4181
7.06M
    // just add it to the disp field and check validity.
4182
7.06M
    
if (7.04M
VariableOperand == -17.04M
) {
4183
6.15M
      AddrMode.BaseOffs += ConstantOffset;
4184
6.15M
      if (ConstantOffset == 0 ||
4185
6.15M
          
TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace)6.12M
) {
4186
6.10M
        // Check to see if we can fold the base pointer in too.
4187
6.10M
        if (matchAddr(AddrInst->getOperand(0), Depth+1)) {
4188
6.10M
          if (!cast<GEPOperator>(AddrInst)->isInBounds())
4189
1.71M
            AddrMode.InBounds = false;
4190
6.10M
          return true;
4191
6.10M
        }
4192
56.8k
      } else if (EnableGEPOffsetSplit && isa<GetElementPtrInst>(AddrInst) &&
4193
56.8k
                 
TLI.shouldConsiderGEPOffsetSplit()51.7k
&&
Depth == 048.0k
&&
4194
56.8k
                 
ConstantOffset > 026.0k
) {
4195
25.7k
        // Record GEPs with non-zero offsets as candidates for splitting in the
4196
25.7k
        // event that the offset cannot fit into the r+i addressing mode.
4197
25.7k
        // Simple and common case that only one GEP is used in calculating the
4198
25.7k
        // address for the memory access.
4199
25.7k
        Value *Base = AddrInst->getOperand(0);
4200
25.7k
        auto *BaseI = dyn_cast<Instruction>(Base);
4201
25.7k
        auto *GEP = cast<GetElementPtrInst>(AddrInst);
4202
25.7k
        if (isa<Argument>(Base) || 
isa<GlobalValue>(Base)19.3k
||
4203
25.7k
            
(19.3k
BaseI19.3k
&&
!isa<CastInst>(BaseI)19.3k
&&
4204
19.9k
             
!isa<GetElementPtrInst>(BaseI)14.0k
)) {
4205
19.9k
          // Make sure the parent block allows inserting non-PHI instructions
4206
19.9k
          // before the terminator.
4207
19.9k
          BasicBlock *Parent =
4208
19.9k
              BaseI ? 
BaseI->getParent()13.4k
:
&GEP->getFunction()->getEntryBlock()6.46k
;
4209
19.9k
          if (!Parent->getTerminator()->isEHPad())
4210
19.9k
            LargeOffsetGEP = std::make_pair(GEP, ConstantOffset);
4211
19.9k
        }
4212
25.7k
      }
4213
6.15M
      AddrMode.BaseOffs -= ConstantOffset;
4214
56.8k
      return false;
4215
890k
    }
4216
890k
4217
890k
    // Save the valid addressing mode in case we can't match.
4218
890k
    ExtAddrMode BackupAddrMode = AddrMode;
4219
890k
    unsigned OldSize = AddrModeInsts.size();
4220
890k
4221
890k
    // See if the scale and offset amount is valid for this target.
4222
890k
    AddrMode.BaseOffs += ConstantOffset;
4223
890k
    if (!cast<GEPOperator>(AddrInst)->isInBounds())
4224
382k
      AddrMode.InBounds = false;
4225
890k
4226
890k
    // Match the base operand of the GEP.
4227
890k
    if (!matchAddr(AddrInst->getOperand(0), Depth+1)) {
4228
1.34k
      // If it couldn't be matched, just stuff the value in a register.
4229
1.34k
      if (AddrMode.HasBaseReg) {
4230
46
        AddrMode = BackupAddrMode;
4231
46
        AddrModeInsts.resize(OldSize);
4232
46
        return false;
4233
46
      }
4234
1.30k
      AddrMode.HasBaseReg = true;
4235
1.30k
      AddrMode.BaseReg = AddrInst->getOperand(0);
4236
1.30k
    }
4237
890k
4238
890k
    // Match the remaining variable portion of the GEP.
4239
890k
    
if (890k
!matchScaledValue(AddrInst->getOperand(VariableOperand), VariableScale,
4240
890k
                          Depth)) {
4241
380k
      // If it couldn't be matched, try stuffing the base into a register
4242
380k
      // instead of matching it, and retrying the match of the scale.
4243
380k
      AddrMode = BackupAddrMode;
4244
380k
      AddrModeInsts.resize(OldSize);
4245
380k
      if (AddrMode.HasBaseReg)
4246
102
        return false;
4247
380k
      AddrMode.HasBaseReg = true;
4248
380k
      AddrMode.BaseReg = AddrInst->getOperand(0);
4249
380k
      AddrMode.BaseOffs += ConstantOffset;
4250
380k
      if (!matchScaledValue(AddrInst->getOperand(VariableOperand),
4251
380k
                            VariableScale, Depth)) {
4252
311k
        // If even that didn't work, bail.
4253
311k
        AddrMode = BackupAddrMode;
4254
311k
        AddrModeInsts.resize(OldSize);
4255
311k
        return false;
4256
311k
      }
4257
578k
    }
4258
578k
4259
578k
    return true;
4260
578k
  }
4261
578k
  case Instruction::SExt:
4262
65.3k
  case Instruction::ZExt: {
4263
65.3k
    Instruction *Ext = dyn_cast<Instruction>(AddrInst);
4264
65.3k
    if (!Ext)
4265
1
      return false;
4266
65.2k
4267
65.2k
    // Try to move this ext out of the way of the addressing mode.
4268
65.2k
    // Ask for a method for doing so.
4269
65.2k
    TypePromotionHelper::Action TPH =
4270
65.2k
        TypePromotionHelper::getAction(Ext, InsertedInsts, TLI, PromotedInsts);
4271
65.2k
    if (!TPH)
4272
53.4k
      return false;
4273
11.8k
4274
11.8k
    TypePromotionTransaction::ConstRestorationPt LastKnownGood =
4275
11.8k
        TPT.getRestorationPoint();
4276
11.8k
    unsigned CreatedInstsCost = 0;
4277
11.8k
    unsigned ExtCost = !TLI.isExtFree(Ext);
4278
11.8k
    Value *PromotedOperand =
4279
11.8k
        TPH(Ext, TPT, PromotedInsts, CreatedInstsCost, nullptr, nullptr, TLI);
4280
11.8k
    // SExt has been moved away.
4281
11.8k
    // Thus either it will be rematched later in the recursive calls or it is
4282
11.8k
    // gone. Anyway, we must not fold it into the addressing mode at this point.
4283
11.8k
    // E.g.,
4284
11.8k
    // op = add opnd, 1
4285
11.8k
    // idx = ext op
4286
11.8k
    // addr = gep base, idx
4287
11.8k
    // is now:
4288
11.8k
    // promotedOpnd = ext opnd            <- no match here
4289
11.8k
    // op = promoted_add promotedOpnd, 1  <- match (later in recursive calls)
4290
11.8k
    // addr = gep base, op                <- match
4291
11.8k
    if (MovedAway)
4292
11.8k
      *MovedAway = true;
4293
11.8k
4294
11.8k
    assert(PromotedOperand &&
4295
11.8k
           "TypePromotionHelper should have filtered out those cases");
4296
11.8k
4297
11.8k
    ExtAddrMode BackupAddrMode = AddrMode;
4298
11.8k
    unsigned OldSize = AddrModeInsts.size();
4299
11.8k
4300
11.8k
    if (!matchAddr(PromotedOperand, Depth) ||
4301
11.8k
        // The total of the new cost is equal to the cost of the created
4302
11.8k
        // instructions.
4303
11.8k
        // The total of the old cost is equal to the cost of the extension plus
4304
11.8k
        // what we have saved in the addressing mode.
4305
11.8k
        !isPromotionProfitable(CreatedInstsCost,
4306
6.25k
                               ExtCost + (AddrModeInsts.size() - OldSize),
4307
10.7k
                               PromotedOperand)) {
4308
10.7k
      AddrMode = BackupAddrMode;
4309
10.7k
      AddrModeInsts.resize(OldSize);
4310
10.7k
      LLVM_DEBUG(dbgs() << "Sign extension does not pay off: rollback\n");
4311
10.7k
      TPT.rollback(LastKnownGood);
4312
10.7k
      return false;
4313
10.7k
    }
4314
1.03k
    return true;
4315
1.03k
  }
4316
5.56M
  }
4317
5.56M
  return false;
4318
5.56M
}
4319
4320
/// If we can, try to add the value of 'Addr' into the current addressing mode.
4321
/// If Addr can't be added to AddrMode this returns false and leaves AddrMode
4322
/// unmodified. This assumes that Addr is either a pointer type or intptr_t
4323
/// for the target.
4324
///
4325
20.3M
bool AddressingModeMatcher::matchAddr(Value *Addr, unsigned Depth) {
4326
20.3M
  // Start a transaction at this point that we will rollback if the matching
4327
20.3M
  // fails.
4328
20.3M
  TypePromotionTransaction::ConstRestorationPt LastKnownGood =
4329
20.3M
      TPT.getRestorationPoint();
4330
20.3M
  if (ConstantInt *CI = dyn_cast<ConstantInt>(Addr)) {
4331
42.3k
    // Fold in immediates if legal for the target.
4332
42.3k
    AddrMode.BaseOffs += CI->getSExtValue();
4333
42.3k
    if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace))
4334
30.0k
      return true;
4335
12.2k
    AddrMode.BaseOffs -= CI->getSExtValue();
4336
20.2M
  } else if (GlobalValue *GV = dyn_cast<GlobalValue>(Addr)) {
4337
809k
    // If this is a global variable, try to fold it into the addressing mode.
4338
809k
    if (!AddrMode.BaseGV) {
4339
809k
      AddrMode.BaseGV = GV;
4340
809k
      if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace))
4341
21.0k
        return true;
4342
788k
      AddrMode.BaseGV = nullptr;
4343
788k
    }
4344
19.4M
  } else if (Instruction *I = dyn_cast<Instruction>(Addr)) {
4345
16.9M
    ExtAddrMode BackupAddrMode = AddrMode;
4346
16.9M
    unsigned OldSize = AddrModeInsts.size();
4347
16.9M
4348
16.9M
    // Check to see if it is possible to fold this operation.
4349
16.9M
    bool MovedAway = false;
4350
16.9M
    if (matchOperationAddr(I, I->getOpcode(), Depth, &MovedAway)) {
4351
10.8M
      // This instruction may have been moved away. If so, there is nothing
4352
10.8M
      // to check here.
4353
10.8M
      if (MovedAway)
4354
1.03k
        return true;
4355
10.8M
      // Okay, it's possible to fold this.  Check to see if it is actually
4356
10.8M
      // *profitable* to do so.  We use a simple cost model to avoid increasing
4357
10.8M
      // register pressure too much.
4358
10.8M
      if (I->hasOneUse() ||
4359
10.8M
          
isProfitableToFoldIntoAddressingMode(I, BackupAddrMode, AddrMode)2.89M
) {
4360
10.7M
        AddrModeInsts.push_back(I);
4361
10.7M
        return true;
4362
10.7M
      }
4363
108k
4364
108k
      // It isn't profitable to do this, roll back.
4365
108k
      //cerr << "NOT FOLDING: " << *I;
4366
108k
      AddrMode = BackupAddrMode;
4367
108k
      AddrModeInsts.resize(OldSize);
4368
108k
      TPT.rollback(LastKnownGood);
4369
108k
    }
4370
16.9M
  } else 
if (ConstantExpr *2.53M
CE2.53M
= dyn_cast<ConstantExpr>(Addr)) {
4371
362k
    if (matchOperationAddr(CE, CE->getOpcode(), Depth))
4372
357k
      return true;
4373
5.24k
    TPT.rollback(LastKnownGood);
4374
2.16M
  } else if (isa<ConstantPointerNull>(Addr)) {
4375
2.14k
    // Null pointer gets folded without affecting the addressing mode.
4376
2.14k
    return true;
4377
2.14k
  }
4378
9.14M
4379
9.14M
  // Worse case, the target should support [reg] addressing modes. :)
4380
9.14M
  if (!AddrMode.HasBaseReg) {
4381
8.66M
    AddrMode.HasBaseReg = true;
4382
8.66M
    AddrMode.BaseReg = Addr;
4383
8.66M
    // Still check for legality in case the target supports [imm] but not [i+r].
4384
8.66M
    if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace))
4385
8.65M
      return true;
4386
6.10k
    AddrMode.HasBaseReg = false;
4387
6.10k
    AddrMode.BaseReg = nullptr;
4388
6.10k
  }
4389
9.14M
4390
9.14M
  // If the base register is already taken, see if we can do [r+r].
4391
9.14M
  
if (490k
AddrMode.Scale == 0490k
) {
4392
441k
    AddrMode.Scale = 1;
4393
441k
    AddrMode.ScaledReg = Addr;
4394
441k
    if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace))
4395
235k
      return true;
4396
206k
    AddrMode.Scale = 0;
4397
206k
    AddrMode.ScaledReg = nullptr;
4398
206k
  }
4399
490k
  // Couldn't match.
4400
490k
  TPT.rollback(LastKnownGood);
4401
254k
  return false;
4402
490k
}
4403
4404
/// Check to see if all uses of OpVal by the specified inline asm call are due
4405
/// to memory operands. If so, return true, otherwise return false.
4406
static bool IsOperandAMemoryOperand(CallInst *CI, InlineAsm *IA, Value *OpVal,
4407
                                    const TargetLowering &TLI,
4408
14
                                    const TargetRegisterInfo &TRI) {
4409
14
  const Function *F = CI->getFunction();
4410
14
  TargetLowering::AsmOperandInfoVector TargetConstraints =
4411
14
      TLI.ParseConstraints(F->getParent()->getDataLayout(), &TRI,
4412
14
                            ImmutableCallSite(CI));
4413
14
4414
68
  for (unsigned i = 0, e = TargetConstraints.size(); i != e; 
++i54
) {
4415
66
    TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
4416
66
4417
66
    // Compute the constraint code and ConstraintType to use.
4418
66
    TLI.ComputeConstraintToUse(OpInfo, SDValue());
4419
66
4420
66
    // If this asm operand is our Value*, and if it isn't an indirect memory
4421
66
    // operand, we can't fold it!
4422
66
    if (OpInfo.CallOperandVal == OpVal &&
4423
66
        
(28
OpInfo.ConstraintType != TargetLowering::C_Memory28
||
4424
28
         
!OpInfo.isIndirect16
))
4425
12
      return false;
4426
66
  }
4427
14
4428
14
  
return true2
;
4429
14
}
4430
4431
// Max number of memory uses to look at before aborting the search to conserve
4432
// compile time.
4433
static constexpr int MaxMemoryUsesToScan = 20;
4434
4435
/// Recursively walk all the uses of I until we find a memory use.
4436
/// If we find an obviously non-foldable instruction, return true.
4437
/// Add the ultimately found memory instructions to MemoryUses.
4438
static bool FindAllMemoryUses(
4439
    Instruction *I,
4440
    SmallVectorImpl<std::pair<Instruction *, unsigned>> &MemoryUses,
4441
    SmallPtrSetImpl<Instruction *> &ConsideredInsts, const TargetLowering &TLI,
4442
1.39M
    const TargetRegisterInfo &TRI, int SeenInsts = 0) {
4443
1.39M
  // If we already considered this instruction, we're done.
4444
1.39M
  if (!ConsideredInsts.insert(I).second)
4445
1.63k
    return false;
4446
1.38M
4447
1.38M
  // If this is an obviously unfoldable instruction, bail out.
4448
1.38M
  if (!MightBeFoldableInst(I))
4449
38.2k
    return true;
4450
1.35M
4451
1.35M
  const bool OptSize = I->getFunction()->hasOptSize();
4452
1.35M
4453
1.35M
  // Loop over all the uses, recursively processing them.
4454
2.38M
  for (Use &U : I->uses()) {
4455
2.38M
    // Conservatively return true if we're seeing a large number or a deep chain
4456
2.38M
    // of users. This avoids excessive compilation times in pathological cases.
4457
2.38M
    if (SeenInsts++ >= MaxMemoryUsesToScan)
4458
22.7k
      return true;
4459
2.35M
4460
2.35M
    Instruction *UserI = cast<Instruction>(U.getUser());
4461
2.35M
    if (LoadInst *LI = dyn_cast<LoadInst>(UserI)) {
4462
731k
      MemoryUses.push_back(std::make_pair(LI, U.getOperandNo()));
4463
731k
      continue;
4464
731k
    }
4465
1.62M
4466
1.62M
    if (StoreInst *SI = dyn_cast<StoreInst>(UserI)) {
4467
442k
      unsigned opNo = U.getOperandNo();
4468
442k
      if (opNo != StoreInst::getPointerOperandIndex())
4469
2.42k
        return true; // Storing addr, not into addr.
4470
440k
      MemoryUses.push_back(std::make_pair(SI, opNo));
4471
440k
      continue;
4472
440k
    }
4473
1.18M
4474
1.18M
    if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(UserI)) {
4475
485
      unsigned opNo = U.getOperandNo();
4476
485
      if (opNo != AtomicRMWInst::getPointerOperandIndex())
4477
0
        return true; // Storing addr, not into addr.
4478
485
      MemoryUses.push_back(std::make_pair(RMW, opNo));
4479
485
      continue;
4480
485
    }
4481
1.18M
4482
1.18M
    if (AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(UserI)) {
4483
114
      unsigned opNo = U.getOperandNo();
4484
114
      if (opNo != AtomicCmpXchgInst::getPointerOperandIndex())
4485
0
        return true; // Storing addr, not into addr.
4486
114
      MemoryUses.push_back(std::make_pair(CmpX, opNo));
4487
114
      continue;
4488
114
    }
4489
1.18M
4490
1.18M
    if (CallInst *CI = dyn_cast<CallInst>(UserI)) {
4491
17.8k
      // If this is a cold call, we can sink the addressing calculation into
4492
17.8k
      // the cold path.  See optimizeCallInst
4493
17.8k
      if (!OptSize && 
CI->hasFnAttr(Attribute::Cold)17.8k
)
4494
7
        continue;
4495
17.8k
4496
17.8k
      InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue());
4497
17.8k
      if (!IA) 
return true17.8k
;
4498
14
4499
14
      // If this is a memory operand, we're cool, otherwise bail out.
4500
14
      if (!IsOperandAMemoryOperand(CI, IA, I, TLI, TRI))
4501
12
        return true;
4502
2
      continue;
4503
2
    }
4504
1.16M
4505
1.16M
    if (FindAllMemoryUses(UserI, MemoryUses, ConsideredInsts, TLI, TRI,
4506
1.16M
                          SeenInsts))
4507
83.8k
      return true;
4508
1.16M
  }
4509
1.35M
4510
1.35M
  
return false1.22M
;
4511
1.35M
}
4512
4513
/// Return true if Val is already known to be live at the use site that we're
4514
/// folding it into. If so, there is no cost to include it in the addressing
4515
/// mode. KnownLive1 and KnownLive2 are two values that we know are live at the
4516
/// instruction already.
4517
bool AddressingModeMatcher::valueAlreadyLiveAtInst(Value *Val,Value *KnownLive1,
4518
4.85M
                                                   Value *KnownLive2) {
4519
4.85M
  // If Val is either of the known-live values, we know it is live!
4520
4.85M
  if (Val == nullptr || 
Val == KnownLive12.52M
||
Val == KnownLive22.52M
)
4521
2.33M
    return true;
4522
2.52M
4523
2.52M
  // All values other than instructions and arguments (e.g. constants) are live.
4524
2.52M
  if (!isa<Instruction>(Val) && 
!isa<Argument>(Val)357k
)
return true18.9k
;
4525
2.50M
4526
2.50M
  // If Val is a constant sized alloca in the entry block, it is live, this is
4527
2.50M
  // true because it is just a reference to the stack/frame pointer, which is
4528
2.50M
  // live for the whole function.
4529
2.50M
  if (AllocaInst *AI = dyn_cast<AllocaInst>(Val))
4530
115k
    if (AI->isStaticAlloca())
4531
115k
      return true;
4532
2.38M
4533
2.38M
  // Check to see if this value is already used in the memory instruction's
4534
2.38M
  // block.  If so, it's already live into the block at the very least, so we
4535
2.38M
  // can reasonably fold it.
4536
2.38M
  return Val->isUsedInBasicBlock(MemoryInst->getParent());
4537
2.38M
}
4538
4539
/// It is possible for the addressing mode of the machine to fold the specified
4540
/// instruction into a load or store that ultimately uses it.
4541
/// However, the specified instruction has multiple uses.
4542
/// Given this, it may actually increase register pressure to fold it
4543
/// into the load. For example, consider this code:
4544
///
4545
///     X = ...
4546
///     Y = X+1
4547
///     use(Y)   -> nonload/store
4548
///     Z = Y+1
4549
///     load Z
4550
///
4551
/// In this case, Y has multiple uses, and can be folded into the load of Z
4552
/// (yielding load [X+2]).  However, doing this will cause both "X" and "X+1" to
4553
/// be live at the use(Y) line.  If we don't fold Y into load Z, we use one
4554
/// fewer register.  Since Y can't be folded into "use(Y)" we don't increase the
4555
/// number of computations either.
4556
///
4557
/// Note that this (like most of CodeGenPrepare) is just a rough heuristic.  If
4558
/// X was live across 'load Z' for other reasons, we actually *would* want to
4559
/// fold the addressing mode in the Z case.  This would make Y die earlier.
4560
bool AddressingModeMatcher::
4561
isProfitableToFoldIntoAddressingMode(Instruction *I, ExtAddrMode &AMBefore,
4562
2.89M
                                     ExtAddrMode &AMAfter) {
4563
2.89M
  if (IgnoreProfitability) 
return true463k
;
4564
2.42M
4565
2.42M
  // AMBefore is the addressing mode before this instruction was folded into it,
4566
2.42M
  // and AMAfter is the addressing mode after the instruction was folded.  Get
4567
2.42M
  // the set of registers referenced by AMAfter and subtract out those
4568
2.42M
  // referenced by AMBefore: this is the set of values which folding in this
4569
2.42M
  // address extends the lifetime of.
4570
2.42M
  //
4571
2.42M
  // Note that there are only two potential values being referenced here,
4572
2.42M
  // BaseReg and ScaleReg (global addresses are always available, as are any
4573
2.42M
  // folded immediates).
4574
2.42M
  Value *BaseReg = AMAfter.BaseReg, *ScaledReg = AMAfter.ScaledReg;
4575
2.42M
4576
2.42M
  // If the BaseReg or ScaledReg was referenced by the previous addrmode, their
4577
2.42M
  // lifetime wasn't extended by adding this instruction.
4578
2.42M
  if (valueAlreadyLiveAtInst(BaseReg, AMBefore.BaseReg, AMBefore.ScaledReg))
4579
2.21M
    BaseReg = nullptr;
4580
2.42M
  if (valueAlreadyLiveAtInst(ScaledReg, AMBefore.BaseReg, AMBefore.ScaledReg))
4581
2.38M
    ScaledReg = nullptr;
4582
2.42M
4583
2.42M
  // If folding this instruction (and it's subexprs) didn't extend any live
4584
2.42M
  // ranges, we're ok with it.
4585
2.42M
  if (!BaseReg && 
!ScaledReg2.21M
)
4586
2.20M
    return true;
4587
225k
4588
225k
  // If all uses of this instruction can have the address mode sunk into them,
4589
225k
  // we can remove the addressing mode and effectively trade one live register
4590
225k
  // for another (at worst.)  In this context, folding an addressing mode into
4591
225k
  // the use is just a particularly nice way of sinking it.
4592
225k
  SmallVector<std::pair<Instruction*,unsigned>, 16> MemoryUses;
4593
225k
  SmallPtrSet<Instruction*, 16> ConsideredInsts;
4594
225k
  if (FindAllMemoryUses(I, MemoryUses, ConsideredInsts, TLI, TRI))
4595
81.2k
    return false;  // Has a non-memory, non-foldable use!
4596
144k
4597
144k
  // Now that we know that all uses of this instruction are part of a chain of
4598
144k
  // computation involving only operations that could theoretically be folded
4599
144k
  // into a memory use, loop over each of these memory operation uses and see
4600
144k
  // if they could  *actually* fold the instruction.  The assumption is that
4601
144k
  // addressing modes are cheap and that duplicating the computation involved
4602
144k
  // many times is worthwhile, even on a fastpath. For sinking candidates
4603
144k
  // (i.e. cold call sites), this serves as a way to prevent excessive code
4604
144k
  // growth since most architectures have some reasonable small and fast way to
4605
144k
  // compute an effective address.  (i.e LEA on x86)
4606
144k
  SmallVector<Instruction*, 32> MatchedAddrModeInsts;
4607
553k
  for (unsigned i = 0, e = MemoryUses.size(); i != e; 
++i408k
) {
4608
435k
    Instruction *User = MemoryUses[i].first;
4609
435k
    unsigned OpNo = MemoryUses[i].second;
4610
435k
4611
435k
    // Get the access type of this use.  If the use isn't a pointer, we don't
4612
435k
    // know what it accesses.
4613
435k
    Value *Address = User->getOperand(OpNo);
4614
435k
    PointerType *AddrTy = dyn_cast<PointerType>(Address->getType());
4615
435k
    if (!AddrTy)
4616
0
      return false;
4617
435k
    Type *AddressAccessTy = AddrTy->getElementType();
4618
435k
    unsigned AS = AddrTy->getAddressSpace();
4619
435k
4620
435k
    // Do a match against the root of this address, ignoring profitability. This
4621
435k
    // will tell us if the addressing mode for the memory operation will
4622
435k
    // *actually* cover the shared instruction.
4623
435k
    ExtAddrMode Result;
4624
435k
    std::pair<AssertingVH<GetElementPtrInst>, int64_t> LargeOffsetGEP(nullptr,
4625
435k
                                                                      0);
4626
435k
    TypePromotionTransaction::ConstRestorationPt LastKnownGood =
4627
435k
        TPT.getRestorationPoint();
4628
435k
    AddressingModeMatcher Matcher(
4629
435k
        MatchedAddrModeInsts, TLI, TRI, AddressAccessTy, AS, MemoryInst, Result,
4630
435k
        InsertedInsts, PromotedInsts, TPT, LargeOffsetGEP);
4631
435k
    Matcher.IgnoreProfitability = true;
4632
435k
    bool Success = Matcher.matchAddr(Address, 0);
4633
435k
    (void)Success; assert(Success && "Couldn't select *anything*?");
4634
435k
4635
435k
    // The match was to check the profitability, the changes made are not
4636
435k
    // part of the original matcher. Therefore, they should be dropped
4637
435k
    // otherwise the original matcher will not present the right state.
4638
435k
    TPT.rollback(LastKnownGood);
4639
435k
4640
435k
    // If the match didn't cover I, then it won't be shared by it.
4641
435k
    if (!is_contained(MatchedAddrModeInsts, I))
4642
26.7k
      return false;
4643
408k
4644
408k
    MatchedAddrModeInsts.clear();
4645
408k
  }
4646
144k
4647
144k
  
return true117k
;
4648
144k
}
4649
4650
/// Return true if the specified values are defined in a
4651
/// different basic block than BB.
4652
9.72M
static bool IsNonLocalValue(Value *V, BasicBlock *BB) {
4653
9.72M
  if (Instruction *I = dyn_cast<Instruction>(V))
4654
9.72M
    return I->getParent() != BB;
4655
0
  return false;
4656
0
}
4657
4658
/// Sink addressing mode computation immediate before MemoryInst if doing so
4659
/// can be done without increasing register pressure.  The need for the
4660
/// register pressure constraint means this can end up being an all or nothing
4661
/// decision for all uses of the same addressing computation.
4662
///
4663
/// Load and Store Instructions often have addressing modes that can do
4664
/// significant amounts of computation. As such, instruction selection will try
4665
/// to get the load or store to do as much computation as possible for the
4666
/// program. The problem is that isel can only see within a single block. As
4667
/// such, we sink as much legal addressing mode work into the block as possible.
4668
///
4669
/// This method is used to optimize both load/store and inline asms with memory
4670
/// operands.  It's also used to sink addressing computations feeding into cold
4671
/// call sites into their (cold) basic block.
4672
///
4673
/// The motivation for handling sinking into cold blocks is that doing so can
4674
/// both enable other address mode sinking (by satisfying the register pressure
4675
/// constraint above), and reduce register pressure globally (by removing the
4676
/// addressing mode computation from the fast path entirely.).
4677
bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
4678
7.72M
                                        Type *AccessTy, unsigned AddrSpace) {
4679
7.72M
  Value *Repl = Addr;
4680
7.72M
4681
7.72M
  // Try to collapse single-value PHI nodes.  This is necessary to undo
4682
7.72M
  // unprofitable PRE transformations.
4683
7.72M
  SmallVector<Value*, 8> worklist;
4684
7.72M
  SmallPtrSet<Value*, 16> Visited;
4685
7.72M
  worklist.push_back(Addr);
4686
7.72M
4687
7.72M
  // Use a worklist to iteratively look through PHI and select nodes, and
4688
7.72M
  // ensure that the addressing mode obtained from the non-PHI/select roots of
4689
7.72M
  // the graph are compatible.
4690
7.72M
  bool PhiOrSelectSeen = false;
4691
7.72M
  SmallVector<Instruction*, 16> AddrModeInsts;
4692
7.72M
  const SimplifyQuery SQ(*DL, TLInfo);
4693
7.72M
  AddressingModeCombiner AddrModes(SQ, Addr);
4694
7.72M
  TypePromotionTransaction TPT(RemovedInsts);
4695
7.72M
  TypePromotionTransaction::ConstRestorationPt LastKnownGood =
4696
7.72M
      TPT.getRestorationPoint();
4697
15.6M
  while (!worklist.empty()) {
4698
7.98M
    Value *V = worklist.back();
4699
7.98M
    worklist.pop_back();
4700
7.98M
4701
7.98M
    // We allow traversing cyclic Phi nodes.
4702
7.98M
    // In case of success after this loop we ensure that traversing through
4703
7.98M
    // Phi nodes ends up with all cases to compute address of the form
4704
7.98M
    //    BaseGV + Base + Scale * Index + Offset
4705
7.98M
    // where Scale and Offset are constans and BaseGV, Base and Index
4706
7.98M
    // are exactly the same Values in all cases.
4707
7.98M
    // It means that BaseGV, Scale and Offset dominate our memory instruction
4708
7.98M
    // and have the same value as they had in address computation represented
4709
7.98M
    // as Phi. So we can safely sink address computation to memory instruction.
4710
7.98M
    if (!Visited.insert(V).second)
4711
16.1k
      continue;
4712
7.97M
4713
7.97M
    // For a PHI node, push all of its incoming values.
4714
7.97M
    if (PHINode *P = dyn_cast<PHINode>(V)) {
4715
125k
      for (Value *IncValue : P->incoming_values())
4716
281k
        worklist.push_back(IncValue);
4717
125k
      PhiOrSelectSeen = true;
4718
125k
      continue;
4719
125k
    }
4720
7.84M
    // Similar for select.
4721
7.84M
    if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
4722
10.7k
      worklist.push_back(SI->getFalseValue());
4723
10.7k
      worklist.push_back(SI->getTrueValue());
4724
10.7k
      PhiOrSelectSeen = true;
4725
10.7k
      continue;
4726
10.7k
    }
4727
7.83M
4728
7.83M
    // For non-PHIs, determine the addressing mode being computed.  Note that
4729
7.83M
    // the result may differ depending on what other uses our candidate
4730
7.83M
    // addressing instructions might have.
4731
7.83M
    AddrModeInsts.clear();
4732
7.83M
    std::pair<AssertingVH<GetElementPtrInst>, int64_t> LargeOffsetGEP(nullptr,
4733
7.83M
                                                                      0);
4734
7.83M
    ExtAddrMode NewAddrMode = AddressingModeMatcher::Match(
4735
7.83M
        V, AccessTy, AddrSpace, MemoryInst, AddrModeInsts, *TLI, *TRI,
4736
7.83M
        InsertedInsts, PromotedInsts, TPT, LargeOffsetGEP);
4737
7.83M
4738
7.83M
    GetElementPtrInst *GEP = LargeOffsetGEP.first;
4739
7.83M
    if (GEP && 
!NewGEPBases.count(GEP)19.9k
) {
4740
19.7k
      // If splitting the underlying data structure can reduce the offset of a
4741
19.7k
      // GEP, collect the GEP.  Skip the GEPs that are the new bases of
4742
19.7k
      // previously split data structures.
4743
19.7k
      LargeOffsetGEPMap[GEP->getPointerOperand()].push_back(LargeOffsetGEP);
4744
19.7k
      if (LargeOffsetGEPID.find(GEP) == LargeOffsetGEPID.end())
4745
16.5k
        LargeOffsetGEPID[GEP] = LargeOffsetGEPID.size();
4746
19.7k
    }
4747
7.83M
4748
7.83M
    NewAddrMode.OriginalValue = V;
4749
7.83M
    if (!AddrModes.addNewAddrMode(NewAddrMode))
4750
79.7k
      break;
4751
7.83M
  }
4752
7.72M
4753
7.72M
  // Try to combine the AddrModes we've collected. If we couldn't collect any,
4754
7.72M
  // or we have multiple but either couldn't combine them or combining them
4755
7.72M
  // wouldn't do anything useful, bail out now.
4756
7.72M
  if (!AddrModes.combineAddrModes()) {
4757
91.2k
    TPT.rollback(LastKnownGood);
4758
91.2k
    return false;
4759
91.2k
  }
4760
7.63M
  TPT.commit();
4761
7.63M
4762
7.63M
  // Get the combined AddrMode (or the only AddrMode, if we only had one).
4763
7.63M
  ExtAddrMode AddrMode = AddrModes.getAddrMode();
4764
7.63M
4765
7.63M
  // If all the instructions matched are already in this BB, don't do anything.
4766
7.63M
  // If we saw a Phi node then it is not local definitely, and if we saw a select
4767
7.63M
  // then we want to push the address calculation past it even if it's already
4768
7.63M
  // in this BB.
4769
9.72M
  if (
!PhiOrSelectSeen7.63M
&&
none_of(AddrModeInsts, [&](Value *V) 7.63M
{
4770
9.72M
        return IsNonLocalValue(V, MemoryInst->getParent());
4771
9.72M
                  })) {
4772
7.32M
    LLVM_DEBUG(dbgs() << "CGP: Found      local addrmode: " << AddrMode
4773
7.32M
                      << "\n");
4774
7.32M
    return false;
4775
7.32M
  }
4776
313k
4777
313k
  // Insert this computation right after this user.  Since our caller is
4778
313k
  // scanning from the top of the BB to the bottom, reuse of the expr are
4779
313k
  // guaranteed to happen later.
4780
313k
  IRBuilder<> Builder(MemoryInst);
4781
313k
4782
313k
  // Now that we determined the addressing expression we want to use and know
4783
313k
  // that we have to sink it into this block.  Check to see if we have already
4784
313k
  // done this for some other load/store instr in this block.  If so, reuse
4785
313k
  // the computation.  Before attempting reuse, check if the address is valid
4786
313k
  // as it may have been erased.
4787
313k
4788
313k
  WeakTrackingVH SunkAddrVH = SunkAddrs[Addr];
4789
313k
4790
313k
  Value * SunkAddr = SunkAddrVH.pointsToAliveValue() ? 
SunkAddrVH22.1k
:
nullptr291k
;
4791
313k
  if (SunkAddr) {
4792
22.1k
    LLVM_DEBUG(dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode
4793
22.1k
                      << " for " << *MemoryInst << "\n");
4794
22.1k
    if (SunkAddr->getType() != Addr->getType())
4795
0
      SunkAddr = Builder.CreatePointerCast(SunkAddr, Addr->getType());
4796
291k
  } else if (AddrSinkUsingGEPs ||
4797
291k
             
(5
!AddrSinkUsingGEPs.getNumOccurrences()5
&&
TM0
&&
TTI->useAA()0
)) {
4798
291k
    // By default, we use the GEP-based method when AA is used later. This
4799
291k
    // prevents new inttoptr/ptrtoint pairs from degrading AA capabilities.
4800
291k
    LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode
4801
291k
                      << " for " << *MemoryInst << "\n");
4802
291k
    Type *IntPtrTy = DL->getIntPtrType(Addr->getType());
4803
291k
    Value *ResultPtr = nullptr, *ResultIndex = nullptr;
4804
291k
4805
291k
    // First, find the pointer.
4806
291k
    if (AddrMode.BaseReg && 
AddrMode.BaseReg->getType()->isPointerTy()291k
) {
4807
288k
      ResultPtr = AddrMode.BaseReg;
4808
288k
      AddrMode.BaseReg = nullptr;
4809
288k
    }
4810
291k
4811
291k
    if (AddrMode.Scale && 
AddrMode.ScaledReg->getType()->isPointerTy()20.0k
) {
4812
0
      // We can't add more than one pointer together, nor can we scale a
4813
0
      // pointer (both of which seem meaningless).
4814
0
      if (ResultPtr || AddrMode.Scale != 1)
4815
0
        return false;
4816
0
4817
0
      ResultPtr = AddrMode.ScaledReg;
4818
0
      AddrMode.Scale = 0;
4819
0
    }
4820
291k
4821
291k
    // It is only safe to sign extend the BaseReg if we know that the math
4822
291k
    // required to create it did not overflow before we extend it. Since
4823
291k
    // the original IR value was tossed in favor of a constant back when
4824
291k
    // the AddrMode was created we need to bail out gracefully if widths
4825
291k
    // do not match instead of extending it.
4826
291k
    //
4827
291k
    // (See below for code to add the scale.)
4828
291k
    if (AddrMode.Scale) {
4829
20.0k
      Type *ScaledRegTy = AddrMode.ScaledReg->getType();
4830
20.0k
      if (cast<IntegerType>(IntPtrTy)->getBitWidth() >
4831
20.0k
          cast<IntegerType>(ScaledRegTy)->getBitWidth())
4832
10
        return false;
4833
291k
    }
4834
291k
4835
291k
    if (AddrMode.BaseGV) {
4836
21
      if (ResultPtr)
4837
0
        return false;
4838
21
4839
21
      ResultPtr = AddrMode.BaseGV;
4840
21
    }
4841
291k
4842
291k
    // If the real base value actually came from an inttoptr, then the matcher
4843
291k
    // will look through it and provide only the integer value. In that case,
4844
291k
    // use it here.
4845
291k
    if (!DL->isNonIntegralPointerType(Addr->getType())) {
4846
291k
      if (!ResultPtr && 
AddrMode.BaseReg3.06k
) {
4847
3.05k
        ResultPtr = Builder.CreateIntToPtr(AddrMode.BaseReg, Addr->getType(),
4848
3.05k
                                           "sunkaddr");
4849
3.05k
        AddrMode.BaseReg = nullptr;
4850
288k
      } else if (!ResultPtr && 
AddrMode.Scale == 19
) {
4851
0
        ResultPtr = Builder.CreateIntToPtr(AddrMode.ScaledReg, Addr->getType(),
4852
0
                                           "sunkaddr");
4853
0
        AddrMode.Scale = 0;
4854
0
      }
4855
291k
    }
4856
291k
4857
291k
    if (!ResultPtr &&
4858
291k
        
!AddrMode.BaseReg11
&&
!AddrMode.Scale9
&&
!AddrMode.BaseOffs9
) {
4859
3
      SunkAddr = Constant::getNullValue(Addr->getType());
4860
291k
    } else if (!ResultPtr) {
4861
8
      return false;
4862
291k
    } else {
4863
291k
      Type *I8PtrTy =
4864
291k
          Builder.getInt8PtrTy(Addr->getType()->getPointerAddressSpace());
4865
291k
      Type *I8Ty = Builder.getInt8Ty();
4866
291k
4867
291k
      // Start with the base register. Do this first so that subsequent address
4868
291k
      // matching finds it last, which will prevent it from trying to match it
4869
291k
      // as the scaled value in case it happens to be a mul. That would be
4870
291k
      // problematic if we've sunk a different mul for the scale, because then
4871
291k
      // we'd end up sinking both muls.
4872
291k
      if (AddrMode.BaseReg) {
4873
2
        Value *V = AddrMode.BaseReg;
4874
2
        if (V->getType() != IntPtrTy)
4875
2
          V = Builder.CreateIntCast(V, IntPtrTy, /*isSigned=*/true, "sunkaddr");
4876
2
4877
2
        ResultIndex = V;
4878
2
      }
4879
291k
4880
291k
      // Add the scale value.
4881
291k
      if (AddrMode.Scale) {
4882
20.0k
        Value *V = AddrMode.ScaledReg;
4883
20.0k
        if (V->getType() == IntPtrTy) {
4884
20.0k
          // done.
4885
20.0k
        } else {
4886
2
          assert(cast<IntegerType>(IntPtrTy)->getBitWidth() <
4887
2
                 cast<IntegerType>(V->getType())->getBitWidth() &&
4888
2
                 "We can't transform if ScaledReg is too narrow");
4889
2
          V = Builder.CreateTrunc(V, IntPtrTy, "sunkaddr");
4890
2
        }
4891
20.0k
4892
20.0k
        if (AddrMode.Scale != 1)
4893
14.0k
          V = Builder.CreateMul(V, ConstantInt::get(IntPtrTy, AddrMode.Scale),
4894
14.0k
                                "sunkaddr");
4895
20.0k
        if (ResultIndex)
4896
0
          ResultIndex = Builder.CreateAdd(ResultIndex, V, "sunkaddr");
4897
20.0k
        else
4898
20.0k
          ResultIndex = V;
4899
20.0k
      }
4900
291k
4901
291k
      // Add in the Base Offset if present.
4902
291k
      if (AddrMode.BaseOffs) {
4903
279k
        Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs);
4904
279k
        if (ResultIndex) {
4905
8.87k
          // We need to add this separately from the scale above to help with
4906
8.87k
          // SDAG consecutive load/store merging.
4907
8.87k
          if (ResultPtr->getType() != I8PtrTy)
4908
5.02k
            ResultPtr = Builder.CreatePointerCast(ResultPtr, I8PtrTy);
4909
8.87k
          ResultPtr =
4910
8.87k
              AddrMode.InBounds
4911
8.87k
                  ? Builder.CreateInBoundsGEP(I8Ty, ResultPtr, ResultIndex,
4912
393
                                              "sunkaddr")
4913
8.87k
                  : 
Builder.CreateGEP(I8Ty, ResultPtr, ResultIndex, "sunkaddr")8.48k
;
4914
8.87k
        }
4915
279k
4916
279k
        ResultIndex = V;
4917
279k
      }
4918
291k
4919
291k
      if (!ResultIndex) {
4920
854
        SunkAddr = ResultPtr;
4921
290k
      } else {
4922
290k
        if (ResultPtr->getType() != I8PtrTy)
4923
271k
          ResultPtr = Builder.CreatePointerCast(ResultPtr, I8PtrTy);
4924
290k
        SunkAddr =
4925
290k
            AddrMode.InBounds
4926
290k
                ? Builder.CreateInBoundsGEP(I8Ty, ResultPtr, ResultIndex,
4927
275k
                                            "sunkaddr")
4928
290k
                : 
Builder.CreateGEP(I8Ty, ResultPtr, ResultIndex, "sunkaddr")15.3k
;
4929
290k
      }
4930
291k
4931
291k
      if (SunkAddr->getType() != Addr->getType())
4932
262k
        SunkAddr = Builder.CreatePointerCast(SunkAddr, Addr->getType());
4933
291k
    }
4934
291k
  } else {
4935
5
    // We'd require a ptrtoint/inttoptr down the line, which we can't do for
4936
5
    // non-integral pointers, so in that case bail out now.
4937
5
    Type *BaseTy = AddrMode.BaseReg ? AddrMode.BaseReg->getType() : 
nullptr0
;
4938
5
    Type *ScaleTy = AddrMode.Scale ? 
AddrMode.ScaledReg->getType()0
: nullptr;
4939
5
    PointerType *BasePtrTy = dyn_cast_or_null<PointerType>(BaseTy);
4940
5
    PointerType *ScalePtrTy = dyn_cast_or_null<PointerType>(ScaleTy);
4941
5
    if (DL->isNonIntegralPointerType(Addr->getType()) ||
4942
5
        
(1
BasePtrTy1
&&
DL->isNonIntegralPointerType(BasePtrTy)1
) ||
4943
5
        
(0
ScalePtrTy0
&&
DL->isNonIntegralPointerType(ScalePtrTy)0
) ||
4944
5
        
(0
AddrMode.BaseGV0
&&
4945
0
         DL->isNonIntegralPointerType(AddrMode.BaseGV->getType())))
4946
5
      return false;
4947
0
4948
0
    LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode
4949
0
                      << " for " << *MemoryInst << "\n");
4950
0
    Type *IntPtrTy = DL->getIntPtrType(Addr->getType());
4951
0
    Value *Result = nullptr;
4952
0
4953
0
    // Start with the base register. Do this first so that subsequent address
4954
0
    // matching finds it last, which will prevent it from trying to match it
4955
0
    // as the scaled value in case it happens to be a mul. That would be
4956
0
    // problematic if we've sunk a different mul for the scale, because then
4957
0
    // we'd end up sinking both muls.
4958
0
    if (AddrMode.BaseReg) {
4959
0
      Value *V = AddrMode.BaseReg;
4960
0
      if (V->getType()->isPointerTy())
4961
0
        V = Builder.CreatePtrToInt(V, IntPtrTy, "sunkaddr");
4962
0
      if (V->getType() != IntPtrTy)
4963
0
        V = Builder.CreateIntCast(V, IntPtrTy, /*isSigned=*/true, "sunkaddr");
4964
0
      Result = V;
4965
0
    }
4966
0
4967
0
    // Add the scale value.
4968
0
    if (AddrMode.Scale) {
4969
0
      Value *V = AddrMode.ScaledReg;
4970
0
      if (V->getType() == IntPtrTy) {
4971
0
        // done.
4972
0
      } else if (V->getType()->isPointerTy()) {
4973
0
        V = Builder.CreatePtrToInt(V, IntPtrTy, "sunkaddr");
4974
0
      } else if (cast<IntegerType>(IntPtrTy)->getBitWidth() <
4975
0
                 cast<IntegerType>(V->getType())->getBitWidth()) {
4976
0
        V = Builder.CreateTrunc(V, IntPtrTy, "sunkaddr");
4977
0
      } else {
4978
0
        // It is only safe to sign extend the BaseReg if we know that the math
4979
0
        // required to create it did not overflow before we extend it. Since
4980
0
        // the original IR value was tossed in favor of a constant back when
4981
0
        // the AddrMode was created we need to bail out gracefully if widths
4982
0
        // do not match instead of extending it.
4983
0
        Instruction *I = dyn_cast_or_null<Instruction>(Result);
4984
0
        if (I && (Result != AddrMode.BaseReg))
4985
0
          I->eraseFromParent();
4986
0
        return false;
4987
0
      }
4988
0
      if (AddrMode.Scale != 1)
4989
0
        V = Builder.CreateMul(V, ConstantInt::get(IntPtrTy, AddrMode.Scale),
4990
0
                              "sunkaddr");
4991
0
      if (Result)
4992
0
        Result = Builder.CreateAdd(Result, V, "sunkaddr");
4993
0
      else
4994
0
        Result = V;
4995
0
    }
4996
0
4997
0
    // Add in the BaseGV if present.
4998
0
    if (AddrMode.BaseGV) {
4999
0
      Value *V = Builder.CreatePtrToInt(AddrMode.BaseGV, IntPtrTy, "sunkaddr");
5000
0
      if (Result)
5001
0
        Result = Builder.CreateAdd(Result, V, "sunkaddr");
5002
0
      else
5003
0
        Result = V;
5004
0
    }
5005
0
5006
0
    // Add in the Base Offset if present.
5007
0
    if (AddrMode.BaseOffs) {
5008
0
      Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs);
5009
0
      if (Result)
5010
0
        Result = Builder.CreateAdd(Result, V, "sunkaddr");
5011
0
      else
5012
0
        Result = V;
5013
0
    }
5014
0
5015
0
    if (!Result)
5016
0
      SunkAddr = Constant::getNullValue(Addr->getType());
5017
0
    else
5018
0
      SunkAddr = Builder.CreateIntToPtr(Result, Addr->getType(), "sunkaddr");
5019
0
  }
5020
313k
5021
313k
  MemoryInst->replaceUsesOfWith(Repl, SunkAddr);
5022
313k
  // Store the newly computed address into the cache. In the case we reused a
5023
313k
  // value, this should be idempotent.
5024
313k
  SunkAddrs[Addr] = WeakTrackingVH(SunkAddr);
5025
313k
5026
313k
  // If we have no uses, recursively delete the value and all dead instructions
5027
313k
  // using it.
5028
313k
  if (Repl->use_empty()) {
5029
132k
    // This can cause recursive deletion, which can invalidate our iterator.
5030
132k
    // Use a WeakTrackingVH to hold onto it in case this happens.
5031
132k
    Value *CurValue = &*CurInstIterator;
5032
132k
    WeakTrackingVH IterHandle(CurValue);
5033
132k
    BasicBlock *BB = CurInstIterator->getParent();
5034
132k
5035
132k
    RecursivelyDeleteTriviallyDeadInstructions(Repl, TLInfo);
5036
132k
5037
132k
    if (IterHandle != CurValue) {
5038
1
      // If the iterator instruction was recursively deleted, start over at the
5039
1
      // start of the block.
5040
1
      CurInstIterator = BB->begin();
5041
1
      SunkAddrs.clear();
5042
1
    }
5043
132k
  }
5044
313k
  ++NumMemoryInsts;
5045
313k
  return true;
5046
313k
}
5047
5048
/// If there are any memory operands, use OptimizeMemoryInst to sink their
5049
/// address computing into the block when possible / profitable.
5050
26.9k
bool CodeGenPrepare::optimizeInlineAsmInst(CallInst *CS) {
5051
26.9k
  bool MadeChange = false;
5052
26.9k
5053
26.9k
  const TargetRegisterInfo *TRI =
5054
26.9k
      TM->getSubtargetImpl(*CS->getFunction())->getRegisterInfo();
5055
26.9k
  TargetLowering::AsmOperandInfoVector TargetConstraints =
5056
26.9k
      TLI->ParseConstraints(*DL, TRI, CS);
5057
26.9k
  unsigned ArgNo = 0;
5058
156k
  for (unsigned i = 0, e = TargetConstraints.size(); i != e; 
++i129k
) {
5059
129k
    TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
5060
129k
5061
129k
    // Compute the constraint code and ConstraintType to use.
5062
129k
    TLI->ComputeConstraintToUse(OpInfo, SDValue());
5063
129k
5064
129k
    if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
5065
129k
        
OpInfo.isIndirect15.7k
) {
5066
482
      Value *OpVal = CS->getArgOperand(ArgNo++);
5067
482
      MadeChange |= optimizeMemoryInst(CS, OpVal, OpVal->getType(), ~0u);
5068
129k
    } else if (OpInfo.Type == InlineAsm::isInput)
5069
6.41k
      ArgNo++;
5070
129k
  }
5071
26.9k
5072
26.9k
  return MadeChange;
5073
26.9k
}
5074
5075
/// Check if all the uses of \p Val are equivalent (or free) zero or
5076
/// sign extensions.
5077
13.6k
static bool hasSameExtUse(Value *Val, const TargetLowering &TLI) {
5078
13.6k
  assert(!Val->use_empty() && "Input must have at least one use");
5079
13.6k
  const Instruction *FirstUser = cast<Instruction>(*Val->user_begin());
5080
13.6k
  bool IsSExt = isa<SExtInst>(FirstUser);
5081
13.6k
  Type *ExtTy = FirstUser->getType();
5082
36.5k
  for (const User *U : Val->users()) {
5083
36.5k
    const Instruction *UI = cast<Instruction>(U);
5084
36.5k
    if ((IsSExt && 
!isa<SExtInst>(UI)35.2k
) ||
(25.0k
!IsSExt25.0k
&&
!isa<ZExtInst>(UI)1.29k
))
5085
11.7k
      return false;
5086
24.8k
    Type *CurTy = UI->getType();
5087
24.8k
    // Same input and output types: Same instruction after CSE.
5088
24.8k
    if (CurTy == ExtTy)
5089
24.5k
      continue;
5090
284
5091
284
    // If IsSExt is true, we are in this situation:
5092
284
    // a = Val
5093
284
    // b = sext ty1 a to ty2
5094
284
    // c = sext ty1 a to ty3
5095
284
    // Assuming ty2 is shorter than ty3, this could be turned into:
5096
284
    // a = Val
5097
284
    // b = sext ty1 a to ty2
5098
284
    // c = sext ty2 b to ty3
5099
284
    // However, the last sext is not free.
5100
284
    if (IsSExt)
5101
196
      return false;
5102
88
5103
88
    // This is a ZExt, maybe this is free to extend from one type to another.
5104
88
    // In that case, we would not account for a different use.
5105
88
    Type *NarrowTy;
5106
88
    Type *LargeTy;
5107
88
    if (ExtTy->getScalarType()->getIntegerBitWidth() >
5108
88
        CurTy->getScalarType()->getIntegerBitWidth()) {
5109
88
      NarrowTy = CurTy;
5110
88
      LargeTy = ExtTy;
5111
88
    } else {
5112
0
      NarrowTy = ExtTy;
5113
0
      LargeTy = CurTy;
5114
0
    }
5115
88
5116
88
    if (!TLI.isZExtFree(NarrowTy, LargeTy))
5117
0
      return false;
5118
88
  }
5119
13.6k
  // All uses are the same or can be derived from one another for free.
5120
13.6k
  
return true1.71k
;
5121
13.6k
}
5122
5123
/// Try to speculatively promote extensions in \p Exts and continue
5124
/// promoting through newly promoted operands recursively as far as doing so is
5125
/// profitable. Save extensions profitably moved up, in \p ProfitablyMovedExts.
5126
/// When some promotion happened, \p TPT contains the proper state to revert
5127
/// them.
5128
///
5129
/// \return true if some promotion happened, false otherwise.
5130
bool CodeGenPrepare::tryToPromoteExts(
5131
    TypePromotionTransaction &TPT, const SmallVectorImpl<Instruction *> &Exts,
5132
    SmallVectorImpl<Instruction *> &ProfitablyMovedExts,
5133
909k
    unsigned CreatedInstsCost) {
5134
909k
  bool Promoted = false;
5135
909k
5136
909k
  // Iterate over all the extensions to try to promote them.
5137
952k
  for (auto I : Exts) {
5138
952k
    // Early check if we directly have ext(load).
5139
952k
    if (isa<LoadInst>(I->getOperand(0))) {
5140
421k
      ProfitablyMovedExts.push_back(I);
5141
421k
      continue;
5142
421k
    }
5143
531k
5144
531k
    // Check whether or not we want to do any promotion.  The reason we have
5145
531k
    // this check inside the for loop is to catch the case where an extension
5146
531k
    // is directly fed by a load because in such case the extension can be moved
5147
531k
    // up without any promotion on its operands.
5148
531k
    if (!TLI || !TLI->enableExtLdPromotion() || 
DisableExtLdPromotion512k
)
5149
19.2k
      return false;
5150
512k
5151
512k
    // Get the action to perform the promotion.
5152
512k
    TypePromotionHelper::Action TPH =
5153
512k
        TypePromotionHelper::getAction(I, InsertedInsts, *TLI, PromotedInsts);
5154
512k
    // Check if we can promote.
5155
512k
    if (!TPH) {
5156
398k
      // Save the current extension as we cannot move up through its operand.
5157
398k
      ProfitablyMovedExts.push_back(I);
5158
398k
      continue;
5159
398k
    }
5160
113k
5161
113k
    // Save the current state.
5162
113k
    TypePromotionTransaction::ConstRestorationPt LastKnownGood =
5163
113k
        TPT.getRestorationPoint();
5164
113k
    SmallVector<Instruction *, 4> NewExts;
5165
113k
    unsigned NewCreatedInstsCost = 0;
5166
113k
    unsigned ExtCost = !TLI->isExtFree(I);
5167
113k
    // Promote.
5168
113k
    Value *PromotedVal = TPH(I, TPT, PromotedInsts, NewCreatedInstsCost,
5169
113k
                             &NewExts, nullptr, *TLI);
5170
113k
    assert(PromotedVal &&
5171
113k
           "TypePromotionHelper should have filtered out those cases");
5172
113k
5173
113k
    // We would be able to merge only one extension in a load.
5174
113k
    // Therefore, if we have more than 1 new extension we heuristically
5175
113k
    // cut this search path, because it means we degrade the code quality.
5176
113k
    // With exactly 2, the transformation is neutral, because we will merge
5177
113k
    // one extension but leave one. However, we optimistically keep going,
5178
113k
    // because the new extension may be removed too.
5179
113k
    long long TotalCreatedInstsCost = CreatedInstsCost + NewCreatedInstsCost;
5180
113k
    // FIXME: It would be possible to propagate a negative value instead of
5181
113k
    // conservatively ceiling it to 0.
5182
113k
    TotalCreatedInstsCost =
5183
113k
        std::max((long long)0, (TotalCreatedInstsCost - ExtCost));
5184
113k
    if (!StressExtLdPromotion &&
5185
113k
        
(113k
TotalCreatedInstsCost > 1113k
||
5186
113k
         
!isPromotedInstructionLegal(*TLI, *DL, PromotedVal)100k
)) {
5187
14.0k
      // This promotion is not profitable, rollback to the previous state, and
5188
14.0k
      // save the current extension in ProfitablyMovedExts as the latest
5189
14.0k
      // speculative promotion turned out to be unprofitable.
5190
14.0k
      TPT.rollback(LastKnownGood);
5191
14.0k
      ProfitablyMovedExts.push_back(I);
5192
14.0k
      continue;
5193
14.0k
    }
5194
99.5k
    // Continue promoting NewExts as far as doing so is profitable.
5195
99.5k
    SmallVector<Instruction *, 2> NewlyMovedExts;
5196
99.5k
    (void)tryToPromoteExts(TPT, NewExts, NewlyMovedExts, TotalCreatedInstsCost);
5197
99.5k
    bool NewPromoted = false;
5198
145k
    for (auto ExtInst : NewlyMovedExts) {
5199
145k
      Instruction *MovedExt = cast<Instruction>(ExtInst);
5200
145k
      Value *ExtOperand = MovedExt->getOperand(0);
5201
145k
      // If we have reached to a load, we need this extra profitability check
5202
145k
      // as it could potentially be merged into an ext(load).
5203
145k
      if (isa<LoadInst>(ExtOperand) &&
5204
145k
          
!(33.7k
StressExtLdPromotion33.7k
||
NewCreatedInstsCost <= ExtCost33.6k
||
5205
33.7k
            
(22.3k
ExtOperand->hasOneUse()22.3k
||
hasSameExtUse(ExtOperand, *TLI)13.6k
)))
5206
11.9k
        continue;
5207
133k
5208
133k
      ProfitablyMovedExts.push_back(MovedExt);
5209
133k
      NewPromoted = true;
5210
133k
    }
5211
99.5k
5212
99.5k
    // If none of speculative promotions for NewExts is profitable, rollback
5213
99.5k
    // and save the current extension (I) as the last profitable extension.
5214
99.5k
    if (!NewPromoted) {
5215
5.94k
      TPT.rollback(LastKnownGood);
5216
5.94k
      ProfitablyMovedExts.push_back(I);
5217
5.94k
      continue;
5218
5.94k
    }
5219
93.6k
    // The promotion is profitable.
5220
93.6k
    Promoted = true;
5221
93.6k
  }
5222
909k
  
return Promoted889k
;
5223
909k
}
5224
5225
/// Merging redundant sexts when one is dominating the other.
5226
26.5k
bool CodeGenPrepare::mergeSExts(Function &F) {
5227
26.5k
  bool Changed = false;
5228
48.0k
  for (auto &Entry : ValToSExtendedUses) {
5229
48.0k
    SExts &Insts = Entry.second;
5230
48.0k
    SExts CurPts;
5231
52.8k
    for (Instruction *Inst : Insts) {
5232
52.8k
      if (RemovedInsts.count(Inst) || 
!isa<SExtInst>(Inst)52.8k
||
5233
52.8k
          
Inst->getOperand(0) != Entry.first52.8k
)
5234
49
        continue;
5235
52.8k
      bool inserted = false;
5236
52.8k
      for (auto &Pt : CurPts) {
5237
13.4k
        if (getDT(F).dominates(Inst, Pt)) {
5238
571
          Pt->replaceAllUsesWith(Inst);
5239
571
          RemovedInsts.insert(Pt);
5240
571
          Pt->removeFromParent();
5241
571
          Pt = Inst;
5242
571
          inserted = true;
5243
571
          Changed = true;
5244
571
          break;
5245
571
        }
5246
12.9k
        if (!getDT(F).dominates(Pt, Inst))
5247
11.7k
          // Give up if we need to merge in a common dominator as the
5248
11.7k
          // experiments show it is not profitable.
5249
11.7k
          continue;
5250
1.14k
        Inst->replaceAllUsesWith(Pt);
5251
1.14k
        RemovedInsts.insert(Inst);
5252
1.14k
        Inst->removeFromParent();
5253
1.14k
        inserted = true;
5254
1.14k
        Changed = true;
5255
1.14k
        break;
5256
1.14k
      }
5257
52.8k
      if (!inserted)
5258
51.1k
        CurPts.push_back(Inst);
5259
52.8k
    }
5260
48.0k
  }
5261
26.5k
  return Changed;
5262
26.5k
}
5263
5264
// Spliting large data structures so that the GEPs accessing them can have
5265
// smaller offsets so that they can be sunk to the same blocks as their users.
5266
// For example, a large struct starting from %base is splitted into two parts
5267
// where the second part starts from %new_base.
5268
//
5269
// Before:
5270
// BB0:
5271
//   %base     =
5272
//
5273
// BB1:
5274
//   %gep0     = gep %base, off0
5275
//   %gep1     = gep %base, off1
5276
//   %gep2     = gep %base, off2
5277
//
5278
// BB2:
5279
//   %load1    = load %gep0
5280
//   %load2    = load %gep1
5281
//   %load3    = load %gep2
5282
//
5283
// After:
5284
// BB0:
5285
//   %base     =
5286
//   %new_base = gep %base, off0
5287
//
5288
// BB1:
5289
//   %new_gep0 = %new_base
5290
//   %new_gep1 = gep %new_base, off1 - off0
5291
//   %new_gep2 = gep %new_base, off2 - off0
5292
//
5293
// BB2:
5294
//   %load1    = load i32, i32* %new_gep0
5295
//   %load2    = load i32, i32* %new_gep1
5296
//   %load3    = load i32, i32* %new_gep2
5297
//
5298
// %new_gep1 and %new_gep2 can be sunk to BB2 now after the splitting because
5299
// their offsets are smaller enough to fit into the addressing mode.
5300
4.26k
bool CodeGenPrepare::splitLargeGEPOffsets() {
5301
4.26k
  bool Changed = false;
5302
11.4k
  for (auto &Entry : LargeOffsetGEPMap) {
5303
11.4k
    Value *OldBase = Entry.first;
5304
11.4k
    SmallVectorImpl<std::pair<AssertingVH<GetElementPtrInst>, int64_t>>
5305
11.4k
        &LargeOffsetGEPs = Entry.second;
5306
11.4k
    auto compareGEPOffset =
5307
11.4k
        [&](const std::pair<GetElementPtrInst *, int64_t> &LHS,
5308
27.6k
            const std::pair<GetElementPtrInst *, int64_t> &RHS) {
5309
27.6k
          if (LHS.first == RHS.first)
5310
7.05k
            return false;
5311
20.5k
          if (LHS.second != RHS.second)
5312
19.3k
            return LHS.second < RHS.second;
5313
1.17k
          return LargeOffsetGEPID[LHS.first] < LargeOffsetGEPID[RHS.first];
5314
1.17k
        };
5315
11.4k
    // Sorting all the GEPs of the same data structures based on the offsets.
5316
11.4k
    llvm::sort(LargeOffsetGEPs, compareGEPOffset);
5317
11.4k
    LargeOffsetGEPs.erase(
5318
11.4k
        std::unique(LargeOffsetGEPs.begin(), LargeOffsetGEPs.end()),
5319
11.4k
        LargeOffsetGEPs.end());
5320
11.4k
    // Skip if all the GEPs have the same offsets.
5321
11.4k
    if (LargeOffsetGEPs.front().second == LargeOffsetGEPs.back().second)
5322
9.98k
      continue;
5323
1.45k
    GetElementPtrInst *BaseGEP = LargeOffsetGEPs.begin()->first;
5324
1.45k
    int64_t BaseOffset = LargeOffsetGEPs.begin()->second;
5325
1.45k
    Value *NewBaseGEP = nullptr;
5326
1.45k
5327
1.45k
    auto LargeOffsetGEP = LargeOffsetGEPs.begin();
5328
7.84k
    while (LargeOffsetGEP != LargeOffsetGEPs.end()) {
5329
6.38k
      GetElementPtrInst *GEP = LargeOffsetGEP->first;
5330
6.38k
      int64_t Offset = LargeOffsetGEP->second;
5331
6.38k
      if (Offset != BaseOffset) {
5332
4.85k
        TargetLowering::AddrMode AddrMode;
5333
4.85k
        AddrMode.BaseOffs = Offset - BaseOffset;
5334
4.85k
        // The result type of the GEP might not be the type of the memory
5335
4.85k
        // access.
5336
4.85k
        if (!TLI->isLegalAddressingMode(*DL, AddrMode,
5337
4.85k
                                        GEP->getResultElementType(),
5338
4.85k
                                        GEP->getAddressSpace())) {
5339
241
          // We need to create a new base if the offset to the current base is
5340
241
          // too large to fit into the addressing mode. So, a very large struct
5341
241
          // may be splitted into several parts.
5342
241
          BaseGEP = GEP;
5343
241
          BaseOffset = Offset;
5344
241
          NewBaseGEP = nullptr;
5345
241
        }
5346
4.85k
      }
5347
6.38k
5348
6.38k
      // Generate a new GEP to replace the current one.
5349
6.38k
      LLVMContext &Ctx = GEP->getContext();
5350
6.38k
      Type *IntPtrTy = DL->getIntPtrType(GEP->getType());
5351
6.38k
      Type *I8PtrTy =
5352
6.38k
          Type::getInt8PtrTy(Ctx, GEP->getType()->getPointerAddressSpace());
5353
6.38k
      Type *I8Ty = Type::getInt8Ty(Ctx);
5354
6.38k
5355
6.38k
      if (!NewBaseGEP) {
5356
1.70k
        // Create a new base if we don't have one yet.  Find the insertion
5357
1.70k
        // pointer for the new base first.
5358
1.70k
        BasicBlock::iterator NewBaseInsertPt;
5359
1.70k
        BasicBlock *NewBaseInsertBB;
5360
1.70k
        if (auto *BaseI = dyn_cast<Instruction>(OldBase)) {
5361
1.06k
          // If the base of the struct is an instruction, the new base will be
5362
1.06k
          // inserted close to it.
5363
1.06k
          NewBaseInsertBB = BaseI->getParent();
5364
1.06k
          if (isa<PHINode>(BaseI))
5365
29
            NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
5366
1.03k
          else if (InvokeInst *Invoke = dyn_cast<InvokeInst>(BaseI)) {
5367
3
            NewBaseInsertBB =
5368
3
                SplitEdge(NewBaseInsertBB, Invoke->getNormalDest());
5369
3
            NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
5370
3
          } else
5371
1.02k
            NewBaseInsertPt = std::next(BaseI->getIterator());
5372
1.06k
        } else {
5373
639
          // If the current base is an argument or global value, the new base
5374
639
          // will be inserted to the entry block.
5375
639
          NewBaseInsertBB = &BaseGEP->getFunction()->getEntryBlock();
5376
639
          NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
5377
639
        }
5378
1.70k
        IRBuilder<> NewBaseBuilder(NewBaseInsertBB, NewBaseInsertPt);
5379
1.70k
        // Create a new base.
5380
1.70k
        Value *BaseIndex = ConstantInt::get(IntPtrTy, BaseOffset);
5381
1.70k
        NewBaseGEP = OldBase;
5382
1.70k
        if (NewBaseGEP->getType() != I8PtrTy)
5383
1.64k
          NewBaseGEP = NewBaseBuilder.CreatePointerCast(NewBaseGEP, I8PtrTy);
5384
1.70k
        NewBaseGEP =
5385
1.70k
            NewBaseBuilder.CreateGEP(I8Ty, NewBaseGEP, BaseIndex, "splitgep");
5386
1.70k
        NewGEPBases.insert(NewBaseGEP);
5387
1.70k
      }
5388
6.38k
5389
6.38k
      IRBuilder<> Builder(GEP);
5390
6.38k
      Value *NewGEP = NewBaseGEP;
5391
6.38k
      if (Offset == BaseOffset) {
5392
1.77k
        if (GEP->getType() != I8PtrTy)
5393
1.61k
          NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType());
5394
4.61k
      } else {
5395
4.61k
        // Calculate the new offset for the new GEP.
5396
4.61k
        Value *Index = ConstantInt::get(IntPtrTy, Offset - BaseOffset);
5397
4.61k
        NewGEP = Builder.CreateGEP(I8Ty, NewBaseGEP, Index);
5398
4.61k
5399
4.61k
        if (GEP->getType() != I8PtrTy)
5400
2.26k
          NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType());
5401
4.61k
      }
5402
6.38k
      GEP->replaceAllUsesWith(NewGEP);
5403
6.38k
      LargeOffsetGEPID.erase(GEP);
5404
6.38k
      LargeOffsetGEP = LargeOffsetGEPs.erase(LargeOffsetGEP);
5405
6.38k
      GEP->eraseFromParent();
5406
6.38k
      Changed = true;
5407
6.38k
    }
5408
1.45k
  }
5409
4.26k
  return Changed;
5410
4.26k
}
5411
5412
/// Return true, if an ext(load) can be formed from an extension in
5413
/// \p MovedExts.
5414
bool CodeGenPrepare::canFormExtLd(
5415
    const SmallVectorImpl<Instruction *> &MovedExts, LoadInst *&LI,
5416
808k
    Instruction *&Inst, bool HasPromoted) {
5417
823k
  for (auto *MovedExtInst : MovedExts) {
5418
823k
    if (isa<LoadInst>(MovedExtInst->getOperand(0))) {
5419
407k
      LI = cast<LoadInst>(MovedExtInst->getOperand(0));
5420
407k
      Inst = MovedExtInst;
5421
407k
      break;
5422
407k
    }
5423
823k
  }
5424
808k
  if (!LI)
5425
400k
    return false;
5426
407k
5427
407k
  // If they're already in the same block, there's nothing to do.
5428
407k
  // Make the cheap checks first if we did not promote.
5429
407k
  // If we promoted, we need to check if it is indeed profitable.
5430
407k
  if (!HasPromoted && 
LI->getParent() == Inst->getParent()391k
)
5431
374k
    return false;
5432
33.2k
5433
33.2k
  return TLI->isExtLoad(LI, Inst, *DL);
5434
33.2k
}
5435
5436
/// Move a zext or sext fed by a load into the same basic block as the load,
5437
/// unless conditions are unfavorable. This allows SelectionDAG to fold the
5438
/// extend into the load.
5439
///
5440
/// E.g.,
5441
/// \code
5442
/// %ld = load i32* %addr
5443
/// %add = add nuw i32 %ld, 4
5444
/// %zext = zext i32 %add to i64
5445
// \endcode
5446
/// =>
5447
/// \code
5448
/// %ld = load i32* %addr
5449
/// %zext = zext i32 %ld to i64
5450
/// %add = add nuw i64 %zext, 4
5451
/// \encode
5452
/// Note that the promotion in %add to i64 is done in tryToPromoteExts(), which
5453
/// allow us to match zext(load i32*) to i64.
5454
///
5455
/// Also, try to promote the computations used to obtain a sign extended
5456
/// value used into memory accesses.
5457
/// E.g.,
5458
/// \code
5459
/// a = add nsw i32 b, 3
5460
/// d = sext i32 a to i64
5461
/// e = getelementptr ..., i64 d
5462
/// \endcode
5463
/// =>
5464
/// \code
5465
/// f = sext i32 b to i64
5466
/// a = add nsw i64 f, 3
5467
/// e = getelementptr ..., i64 a
5468
/// \endcode
5469
///
5470
/// \p Inst[in/out] the extension may be modified during the process if some
5471
/// promotions apply.
5472
808k
bool CodeGenPrepare::optimizeExt(Instruction *&Inst) {
5473
808k
  // ExtLoad formation and address type promotion infrastructure requires TLI to
5474
808k
  // be effective.
5475
808k
  if (!TLI)
5476
5
    return false;
5477
808k
5478
808k
  bool AllowPromotionWithoutCommonHeader = false;
5479
808k
  /// See if it is an interesting sext operations for the address type
5480
808k
  /// promotion before trying to promote it, e.g., the ones with the right
5481
808k
  /// type and used in memory accesses.
5482
808k
  bool ATPConsiderable = TTI->shouldConsiderAddressTypePromotion(
5483
808k
      *Inst, AllowPromotionWithoutCommonHeader);
5484
808k
  TypePromotionTransaction TPT(RemovedInsts);
5485
808k
  TypePromotionTransaction::ConstRestorationPt LastKnownGood =
5486
808k
      TPT.getRestorationPoint();
5487
808k
  SmallVector<Instruction *, 1> Exts;
5488
808k
  SmallVector<Instruction *, 2> SpeculativelyMovedExts;
5489
808k
  Exts.push_back(Inst);
5490
808k
5491
808k
  bool HasPromoted = tryToPromoteExts(TPT, Exts, SpeculativelyMovedExts);
5492
808k
5493
808k
  // Look for a load being extended.
5494
808k
  LoadInst *LI = nullptr;
5495
808k
  Instruction *ExtFedByLoad;
5496
808k
5497
808k
  // Try to promote a chain of computation if it allows to form an extended
5498
808k
  // load.
5499
808k
  if (canFormExtLd(SpeculativelyMovedExts, LI, ExtFedByLoad, HasPromoted)) {
5500
33.1k
    assert(LI && ExtFedByLoad && "Expect a valid load and extension");
5501
33.1k
    TPT.commit();
5502
33.1k
    // Move the extend into the same block as the load
5503
33.1k
    ExtFedByLoad->moveAfter(LI);
5504
33.1k
    // CGP does not check if the zext would be speculatively executed when moved
5505
33.1k
    // to the same basic block as the load. Preserving its original location
5506
33.1k
    // would pessimize the debugging experience, as well as negatively impact
5507
33.1k
    // the quality of sample pgo. We don't want to use "line 0" as that has a
5508
33.1k
    // size cost in the line-table section and logically the zext can be seen as
5509
33.1k
    // part of the load. Therefore we conservatively reuse the same debug
5510
33.1k
    // location for the load and the zext.
5511
33.1k
    ExtFedByLoad->setDebugLoc(LI->getDebugLoc());
5512
33.1k
    ++NumExtsMoved;
5513
33.1k
    Inst = ExtFedByLoad;
5514
33.1k
    return true;
5515
33.1k
  }
5516
775k
5517
775k
  // Continue promoting SExts if known as considerable depending on targets.
5518
775k
  if (ATPConsiderable &&
5519
775k
      performAddressTypePromotion(Inst, AllowPromotionWithoutCommonHeader,
5520
102k
                                  HasPromoted, TPT, SpeculativelyMovedExts))
5521
3.36k
    return true;
5522
771k
5523
771k
  TPT.rollback(LastKnownGood);
5524
771k
  return false;
5525
771k
}
5526
5527
// Perform address type promotion if doing so is profitable.
5528
// If AllowPromotionWithoutCommonHeader == false, we should find other sext
5529
// instructions that sign extended the same initial value. However, if
5530
// AllowPromotionWithoutCommonHeader == true, we expect promoting the
5531
// extension is just profitable.
5532
bool CodeGenPrepare::performAddressTypePromotion(
5533
    Instruction *&Inst, bool AllowPromotionWithoutCommonHeader,
5534
    bool HasPromoted, TypePromotionTransaction &TPT,
5535
102k
    SmallVectorImpl<Instruction *> &SpeculativelyMovedExts) {
5536
102k
  bool Promoted = false;
5537
102k
  SmallPtrSet<Instruction *, 1> UnhandledExts;
5538
102k
  bool AllSeenFirst = true;
5539
106k
  for (auto I : SpeculativelyMovedExts) {
5540
106k
    Value *HeadOfChain = I->getOperand(0);
5541
106k
    DenseMap<Value *, Instruction *>::iterator AlreadySeen =
5542
106k
        SeenChainsForSExt.find(HeadOfChain);
5543
106k
    // If there is an unhandled SExt which has the same header, try to promote
5544
106k
    // it as well.
5545
106k
    if (AlreadySeen != SeenChainsForSExt.end()) {
5546
4.88k
      if (AlreadySeen->second != nullptr)
5547
1.47k
        UnhandledExts.insert(AlreadySeen->second);
5548
4.88k
      AllSeenFirst = false;
5549
4.88k
    }
5550
106k
  }
5551
102k
5552
102k
  if (!AllSeenFirst || 
(98.0k
AllowPromotionWithoutCommonHeader98.0k
&&
5553
98.0k
                        
SpeculativelyMovedExts.size() == 146.2k
)) {
5554
50.9k
    TPT.commit();
5555
50.9k
    if (HasPromoted)
5556
3.25k
      Promoted = true;
5557
51.3k
    for (auto I : SpeculativelyMovedExts) {
5558
51.3k
      Value *HeadOfChain = I->getOperand(0);
5559
51.3k
      SeenChainsForSExt[HeadOfChain] = nullptr;
5560
51.3k
      ValToSExtendedUses[HeadOfChain].push_back(I);
5561
51.3k
    }
5562
50.9k
    // Update Inst as promotion happen.
5563
50.9k
    Inst = SpeculativelyMovedExts.pop_back_val();
5564
51.9k
  } else {
5565
51.9k
    // This is the first chain visited from the header, keep the current chain
5566
51.9k
    // as unhandled. Defer to promote this until we encounter another SExt
5567
51.9k
    // chain derived from the same header.
5568
55.3k
    for (auto I : SpeculativelyMovedExts) {
5569
55.3k
      Value *HeadOfChain = I->getOperand(0);
5570
55.3k
      SeenChainsForSExt[HeadOfChain] = Inst;
5571
55.3k
    }
5572
51.9k
    return false;
5573
51.9k
  }
5574
50.9k
5575
50.9k
  if (!AllSeenFirst && 
!UnhandledExts.empty()4.85k
)
5576
1.47k
    
for (auto VisitedSExt : UnhandledExts)1.46k
{
5577
1.47k
      if (RemovedInsts.count(VisitedSExt))
5578
11
        continue;
5579
1.45k
      TypePromotionTransaction TPT(RemovedInsts);
5580
1.45k
      SmallVector<Instruction *, 1> Exts;
5581
1.45k
      SmallVector<Instruction *, 2> Chains;
5582
1.45k
      Exts.push_back(VisitedSExt);
5583
1.45k
      bool HasPromoted = tryToPromoteExts(TPT, Exts, Chains);
5584
1.45k
      TPT.commit();
5585
1.45k
      if (HasPromoted)
5586
281
        Promoted = true;
5587
1.53k
      for (auto I : Chains) {
5588
1.53k
        Value *HeadOfChain = I->getOperand(0);
5589
1.53k
        // Mark this as handled.
5590
1.53k
        SeenChainsForSExt[HeadOfChain] = nullptr;
5591
1.53k
        ValToSExtendedUses[HeadOfChain].push_back(I);
5592
1.53k
      }
5593
1.45k
    }
5594
50.9k
  return Promoted;
5595
50.9k
}
5596
5597
808k
bool CodeGenPrepare::optimizeExtUses(Instruction *I) {
5598
808k
  BasicBlock *DefBB = I->getParent();
5599
808k
5600
808k
  // If the result of a {s|z}ext and its source are both live out, rewrite all
5601
808k
  // other uses of the source with result of extension.
5602
808k
  Value *Src = I->getOperand(0);
5603
808k
  if (Src->hasOneUse())
5604
475k
    return false;
5605
332k
5606
332k
  // Only do this xform if truncating is free.
5607
332k
  if (TLI && 
!TLI->isTruncateFree(I->getType(), Src->getType())332k
)
5608
4.55k
    return false;
5609
328k
5610
328k
  // Only safe to perform the optimization if the source is also defined in
5611
328k
  // this block.
5612
328k
  if (!isa<Instruction>(Src) || 
DefBB != cast<Instruction>(Src)->getParent()251k
)
5613
119k
    return false;
5614
208k
5615
208k
  bool DefIsLiveOut = false;
5616
222k
  for (User *U : I->users()) {
5617
222k
    Instruction *UI = cast<Instruction>(U);
5618
222k
5619
222k
    // Figure out which BB this ext is used in.
5620
222k
    BasicBlock *UserBB = UI->getParent();
5621
222k
    if (UserBB == DefBB) 
continue114k
;
5622
107k
    DefIsLiveOut = true;
5623
107k
    break;
5624
107k
  }
5625
208k
  if (!DefIsLiveOut)
5626
101k
    return false;
5627
107k
5628
107k
  // Make sure none of the uses are PHI nodes.
5629
346k
  
for (User *U : Src->users())107k
{
5630
346k
    Instruction *UI = cast<Instruction>(U);
5631
346k
    BasicBlock *UserBB = UI->getParent();
5632
346k
    if (UserBB == DefBB) 
continue163k
;
5633
183k
    // Be conservative. We don't want this xform to end up introducing
5634
183k
    // reloads just before load / store instructions.
5635
183k
    if (isa<PHINode>(UI) || 
isa<LoadInst>(UI)172k
||
isa<StoreInst>(UI)172k
)
5636
11.7k
      return false;
5637
183k
  }
5638
107k
5639
107k
  // InsertedTruncs - Only insert one trunc in each block once.
5640
107k
  DenseMap<BasicBlock*, Instruction*> InsertedTruncs;
5641
95.6k
5642
95.6k
  bool MadeChange = false;
5643
157k
  for (Use &U : Src->uses()) {
5644
157k
    Instruction *User = cast<Instruction>(U.getUser());
5645
157k
5646
157k
    // Figure out which BB this ext is used in.
5647
157k
    BasicBlock *UserBB = User->getParent();
5648
157k
    if (UserBB == DefBB) 
continue103k
;
5649
54.7k
5650
54.7k
    // Both src and def are live in this block. Rewrite the use.
5651
54.7k
    Instruction *&InsertedTrunc = InsertedTruncs[UserBB];
5652
54.7k
5653
54.7k
    if (!InsertedTrunc) {
5654
54.7k
      BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt();
5655
54.7k
      assert(InsertPt != UserBB->end());
5656
54.7k
      InsertedTrunc = new TruncInst(I, Src->getType(), "", &*InsertPt);
5657
54.7k
      InsertedInsts.insert(InsertedTrunc);
5658
54.7k
    }
5659
54.7k
5660
54.7k
    // Replace a use of the {s|z}ext source with a use of the result.
5661
54.7k
    U = InsertedTrunc;
5662
54.7k
    ++NumExtUses;
5663
54.7k
    MadeChange = true;
5664
54.7k
  }
5665
95.6k
5666
95.6k
  return MadeChange;
5667
107k
}
5668
5669
// Find loads whose uses only use some of the loaded value's bits.  Add an "and"
5670
// just after the load if the target can fold this into one extload instruction,
5671
// with the hope of eliminating some of the other later "and" instructions using
5672
// the loaded value.  "and"s that are made trivially redundant by the insertion
5673
// of the new "and" are removed by this function, while others (e.g. those whose
5674
// path from the load goes through a phi) are left for isel to potentially
5675
// remove.
5676
//
5677
// For example:
5678
//
5679
// b0:
5680
//   x = load i32
5681
//   ...
5682
// b1:
5683
//   y = and x, 0xff
5684
//   z = use y
5685
//
5686
// becomes:
5687
//
5688
// b0:
5689
//   x = load i32
5690
//   x' = and x, 0xff
5691
//   ...
5692
// b1:
5693
//   z = use x'
5694
//
5695
// whereas:
5696
//
5697
// b0:
5698
//   x1 = load i32
5699
//   ...
5700
// b1:
5701
//   x2 = load i32
5702
//   ...
5703
// b2:
5704
//   x = phi x1, x2
5705
//   y = and x, 0xff
5706
//
5707
// becomes (after a call to optimizeLoadExt for each load):
5708
//
5709
// b0:
5710
//   x1 = load i32
5711
//   x1' = and x1, 0xff
5712
//   ...
5713
// b1:
5714
//   x2 = load i32
5715
//   x2' = and x2, 0xff
5716
//   ...
5717
// b2:
5718
//   x = phi x1', x2'
5719
//   y = and x, 0xff
5720
3.66M
bool CodeGenPrepare::optimizeLoadExt(LoadInst *Load) {
5721
3.66M
  if (!Load->isSimple() || 
!Load->getType()->isIntOrPtrTy()3.62M
)
5722
304k
    return false;
5723
3.35M
5724
3.35M
  // Skip loads we've already transformed.
5725
3.35M
  if (Load->hasOneUse() &&
5726
3.35M
      
InsertedInsts.count(cast<Instruction>(*Load->user_begin()))2.24M
)
5727
254
    return false;
5728
3.35M
5729
3.35M
  // Look at all uses of Load, looking through phis, to determine how many bits
5730
3.35M
  // of the loaded value are needed.
5731
3.35M
  SmallVector<Instruction *, 8> WorkList;
5732
3.35M
  SmallPtrSet<Instruction *, 16> Visited;
5733
3.35M
  SmallVector<Instruction *, 8> AndsToMaybeRemove;
5734
3.35M
  for (auto *U : Load->users())
5735
5.44M
    WorkList.push_back(cast<Instruction>(U));
5736
3.35M
5737
3.35M
  EVT LoadResultVT = TLI->getValueType(*DL, Load->getType());
5738
3.35M
  unsigned BitWidth = LoadResultVT.getSizeInBits();
5739
3.35M
  APInt DemandBits(BitWidth, 0);
5740
3.35M
  APInt WidestAndBits(BitWidth, 0);
5741
3.35M
5742
3.68M
  while (!WorkList.empty()) {
5743
3.62M
    Instruction *I = WorkList.back();
5744
3.62M
    WorkList.pop_back();
5745
3.62M
5746
3.62M
    // Break use-def graph loops.
5747
3.62M
    if (!Visited.insert(I).second)
5748
17.9k
      continue;
5749
3.60M
5750
3.60M
    // For a PHI node, push all of its users.
5751
3.60M
    if (auto *Phi = dyn_cast<PHINode>(I)) {
5752
195k
      for (auto *U : Phi->users())
5753
385k
        WorkList.push_back(cast<Instruction>(U));
5754
195k
      continue;
5755
195k
    }
5756
3.41M
5757
3.41M
    switch (I->getOpcode()) {
5758
3.41M
    case Instruction::And: {
5759
52.6k
      auto *AndC = dyn_cast<ConstantInt>(I->getOperand(1));
5760
52.6k
      if (!AndC)
5761
10.4k
        return false;
5762
42.1k
      APInt AndBits = AndC->getValue();
5763
42.1k
      DemandBits |= AndBits;
5764
42.1k
      // Keep track of the widest and mask we see.
5765
42.1k
      if (AndBits.ugt(WidestAndBits))
5766
40.8k
        WidestAndBits = AndBits;
5767
42.1k
      if (AndBits == WidestAndBits && 
I->getOperand(0) == Load41.1k
)
5768
39.5k
        AndsToMaybeRemove.push_back(I);
5769
42.1k
      break;
5770
42.1k
    }
5771
42.1k
5772
42.1k
    case Instruction::Shl: {
5773
16.1k
      auto *ShlC = dyn_cast<ConstantInt>(I->getOperand(1));
5774
16.1k
      if (!ShlC)
5775
1.13k
        return false;
5776
14.9k
      uint64_t ShiftAmt = ShlC->getLimitedValue(BitWidth - 1);
5777
14.9k
      DemandBits.setLowBits(BitWidth - ShiftAmt);
5778
14.9k
      break;
5779
14.9k
    }
5780
14.9k
5781
59.2k
    case Instruction::Trunc: {
5782
59.2k
      EVT TruncVT = TLI->getValueType(*DL, I->getType());
5783
59.2k
      unsigned TruncBitWidth = TruncVT.getSizeInBits();
5784
59.2k
      DemandBits.setLowBits(TruncBitWidth);
5785
59.2k
      break;
5786
14.9k
    }
5787
14.9k
5788
3.28M
    default:
5789
3.28M
      return false;
5790
3.41M
    }
5791
3.41M
  }
5792
3.35M
5793
3.35M
  uint32_t ActiveBits = DemandBits.getActiveBits();
5794
57.9k
  // Avoid hoisting (and (load x) 1) since it is unlikely to be folded by the
5795
57.9k
  // target even if isLoadExtLegal says an i1 EXTLOAD is valid.  For example,
5796
57.9k
  // for the AArch64 target isLoadExtLegal(ZEXTLOAD, i32, i1) returns true, but
5797
57.9k
  // (and (load x) 1) is not matched as a single instruction, rather as a LDR
5798
57.9k
  // followed by an AND.
5799
57.9k
  // TODO: Look into removing this restriction by fixing backends to either
5800
57.9k
  // return false for isLoadExtLegal for i1 or have them select this pattern to
5801
57.9k
  // a single instruction.
5802
57.9k
  //
5803
57.9k
  // Also avoid hoisting if we didn't see any ands with the exact DemandBits
5804
57.9k
  // mask, since these are the only ands that will be removed by isel.
5805
57.9k
  if (ActiveBits <= 1 || 
!DemandBits.isMask(ActiveBits)45.8k
||
5806
57.9k
      
WidestAndBits != DemandBits31.5k
)
5807
53.6k
    return false;
5808
4.30k
5809
4.30k
  LLVMContext &Ctx = Load->getType()->getContext();
5810
4.30k
  Type *TruncTy = Type::getIntNTy(Ctx, ActiveBits);
5811
4.30k
  EVT TruncVT = TLI->getValueType(*DL, TruncTy);
5812
4.30k
5813
4.30k
  // Reject cases that won't be matched as extloads.
5814
4.30k
  if (!LoadResultVT.bitsGT(TruncVT) || 
!TruncVT.isRound()4.29k
||
5815
4.30k
      
!TLI->isLoadExtLegal(ISD::ZEXTLOAD, LoadResultVT, TruncVT)1.72k
)
5816
2.70k
    return false;
5817
1.60k
5818
1.60k
  IRBuilder<> Builder(Load->getNextNode());
5819
1.60k
  auto *NewAnd = dyn_cast<Instruction>(
5820
1.60k
      Builder.CreateAnd(Load, ConstantInt::get(Ctx, DemandBits)));
5821
1.60k
  // Mark this instruction as "inserted by CGP", so that other
5822
1.60k
  // optimizations don't touch it.
5823
1.60k
  InsertedInsts.insert(NewAnd);
5824
1.60k
5825
1.60k
  // Replace all uses of load with new and (except for the use of load in the
5826
1.60k
  // new and itself).
5827
1.60k
  Load->replaceAllUsesWith(NewAnd);
5828
1.60k
  NewAnd->setOperand(0, Load);
5829
1.60k
5830
1.60k
  // Remove any and instructions that are now redundant.
5831
1.60k
  for (auto *And : AndsToMaybeRemove)
5832
1.58k
    // Check that the and mask is the same as the one we decided to put on the
5833
1.58k
    // new and.
5834
1.58k
    if (cast<ConstantInt>(And->getOperand(1))->getValue() == DemandBits) {
5835
1.58k
      And->replaceAllUsesWith(NewAnd);
5836
1.58k
      if (&*CurInstIterator == And)
5837
1.49k
        CurInstIterator = std::next(And->getIterator());
5838
1.58k
      And->eraseFromParent();
5839
1.58k
      ++NumAndUses;
5840
1.58k
    }
5841
1.60k
5842
1.60k
  ++NumAndsAdded;
5843
1.60k
  return true;
5844
1.60k
}
5845
5846
/// Check if V (an operand of a select instruction) is an expensive instruction
5847
/// that is only used once.
5848
33.6k
static bool sinkSelectOperand(const TargetTransformInfo *TTI, Value *V) {
5849
33.6k
  auto *I = dyn_cast<Instruction>(V);
5850
33.6k
  // If it's safe to speculatively execute, then it should not have side
5851
33.6k
  // effects; therefore, it's safe to sink and possibly *not* execute.
5852
33.6k
  return I && 
I->hasOneUse()20.9k
&&
isSafeToSpeculativelyExecute(I)8.88k
&&
5853
33.6k
         
TTI->getUserCost(I) >= TargetTransformInfo::TCC_Expensive8.06k
;
5854
33.6k
}
5855
5856
/// Returns true if a SelectInst should be turned into an explicit branch.
5857
static bool isFormingBranchFromSelectProfitable(const TargetTransformInfo *TTI,
5858
                                                const TargetLowering *TLI,
5859
268k
                                                SelectInst *SI) {
5860
268k
  // If even a predictable select is cheap, then a branch can't be cheaper.
5861
268k
  if (!TLI->isPredictableSelectExpensive())
5862
245k
    return false;
5863
23.3k
5864
23.3k
  // FIXME: This should use the same heuristics as IfConversion to determine
5865
23.3k
  // whether a select is better represented as a branch.
5866
23.3k
5867
23.3k
  // If metadata tells us that the select condition is obviously predictable,
5868
23.3k
  // then we want to replace the select with a branch.
5869
23.3k
  uint64_t TrueWeight, FalseWeight;
5870
23.3k
  if (SI->extractProfMetadata(TrueWeight, FalseWeight)) {
5871
15
    uint64_t Max = std::max(TrueWeight, FalseWeight);
5872
15
    uint64_t Sum = TrueWeight + FalseWeight;
5873
15
    if (Sum != 0) {
5874
14
      auto Probability = BranchProbability::getBranchProbability(Max, Sum);
5875
14
      if (Probability > TLI->getPredictableBranchThreshold())
5876
9
        return true;
5877
23.3k
    }
5878
15
  }
5879
23.3k
5880
23.3k
  CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
5881
23.3k
5882
23.3k
  // If a branch is predictable, an out-of-order CPU can avoid blocking on its
5883
23.3k
  // comparison condition. If the compare has more than one use, there's
5884
23.3k
  // probably another cmov or setcc around, so it's not worth emitting a branch.
5885
23.3k
  if (!Cmp || 
!Cmp->hasOneUse()19.1k
)
5886
6.69k
    return false;
5887
16.6k
5888
16.6k
  // If either operand of the select is expensive and only needed on one side
5889
16.6k
  // of the select, we should form a branch.
5890
16.6k
  if (sinkSelectOperand(TTI, SI->getTrueValue()) ||
5891
16.6k
      
sinkSelectOperand(TTI, SI->getFalseValue())16.6k
)
5892
29
    return true;
5893
16.6k
5894
16.6k
  return false;
5895
16.6k
}
5896
5897
/// If \p isTrue is true, return the true value of \p SI, otherwise return
5898
/// false value of \p SI. If the true/false value of \p SI is defined by any
5899
/// select instructions in \p Selects, look through the defining select
5900
/// instruction until the true/false value is not defined in \p Selects.
5901
static Value *getTrueOrFalseValue(
5902
    SelectInst *SI, bool isTrue,
5903
302
    const SmallPtrSet<const Instruction *, 2> &Selects) {
5904
302
  Value *V = nullptr;
5905
302
5906
607
  for (SelectInst *DefSI = SI; DefSI != nullptr && 
Selects.count(DefSI)305
;
5907
305
       DefSI = dyn_cast<SelectInst>(V)) {
5908
305
    assert(DefSI->getCondition() == SI->getCondition() &&
5909
305
           "The condition of DefSI does not match with SI");
5910
305
    V = (isTrue ? 
DefSI->getTrueValue()154
:
DefSI->getFalseValue()151
);
5911
305
  }
5912
302
5913
302
  assert(V && "Failed to get select true/false value");
5914
302
  return V;
5915
302
}
5916
5917
485k
bool CodeGenPrepare::optimizeShiftInst(BinaryOperator *Shift) {
5918
485k
  assert(Shift->isShift() && "Expected a shift");
5919
485k
5920
485k
  // If this is (1) a vector shift, (2) shifts by scalars are cheaper than
5921
485k
  // general vector shifts, and (3) the shift amount is a select-of-splatted
5922
485k
  // values, hoist the shifts before the select:
5923
485k
  //   shift Op0, (select Cond, TVal, FVal) -->
5924
485k
  //   select Cond, (shift Op0, TVal), (shift Op0, FVal)
5925
485k
  //
5926
485k
  // This is inverting a generic IR transform when we know that the cost of a
5927
485k
  // general vector shift is more than the cost of 2 shift-by-scalars.
5928
485k
  // We can't do this effectively in SDAG because we may not be able to
5929
485k
  // determine if the select operands are splats from within a basic block.
5930
485k
  Type *Ty = Shift->getType();
5931
485k
  if (!Ty->isVectorTy() || 
!TLI->isVectorShiftByScalarCheap(Ty)19.7k
)
5932
481k
    return false;
5933
3.61k
  Value *Cond, *TVal, *FVal;
5934
3.61k
  if (!match(Shift->getOperand(1),
5935
3.61k
             m_OneUse(m_Select(m_Value(Cond), m_Value(TVal), m_Value(FVal)))))
5936
3.59k
    return false;
5937
18
  if (!isSplatValue(TVal) || !isSplatValue(FVal))
5938
0
    return false;
5939
18
5940
18
  IRBuilder<> Builder(Shift);
5941
18
  BinaryOperator::BinaryOps Opcode = Shift->getOpcode();
5942
18
  Value *NewTVal = Builder.CreateBinOp(Opcode, Shift->getOperand(0), TVal);
5943
18
  Value *NewFVal = Builder.CreateBinOp(Opcode, Shift->getOperand(0), FVal);
5944
18
  Value *NewSel = Builder.CreateSelect(Cond, NewTVal, NewFVal);
5945
18
  Shift->replaceAllUsesWith(NewSel);
5946
18
  Shift->eraseFromParent();
5947
18
  return true;
5948
18
}
5949
5950
/// If we have a SelectInst that will likely profit from branch prediction,
5951
/// turn it into a branch.
5952
303k
bool CodeGenPrepare::optimizeSelectInst(SelectInst *SI) {
5953
303k
  // If branch conversion isn't desirable, exit early.
5954
303k
  if (DisableSelectToBranch || 
OptSize303k
||
!TLI301k
)
5955
1.60k
    return false;
5956
301k
5957
301k
  // Find all consecutive select instructions that share the same condition.
5958
301k
  SmallVector<SelectInst *, 2> ASI;
5959
301k
  ASI.push_back(SI);
5960
301k
  for (BasicBlock::iterator It = ++BasicBlock::iterator(SI);
5961
322k
       It != SI->getParent()->end(); 
++It21.3k
) {
5962
322k
    SelectInst *I = dyn_cast<SelectInst>(&*It);
5963
322k
    if (I && 
SI->getCondition() == I->getCondition()28.1k
) {
5964
21.3k
      ASI.push_back(I);
5965
301k
    } else {
5966
301k
      break;
5967
301k
    }
5968
322k
  }
5969
301k
5970
301k
  SelectInst *LastSI = ASI.back();
5971
301k
  // Increment the current iterator to skip all the rest of select instructions
5972
301k
  // because they will be either "not lowered" or "all lowered" to branch.
5973
301k
  CurInstIterator = std::next(LastSI->getIterator());
5974
301k
5975
301k
  bool VectorCond = !SI->getCondition()->getType()->isIntegerTy(1);
5976
301k
5977
301k
  // Can we convert the 'select' to CF ?
5978
301k
  if (VectorCond || 
SI->getMetadata(LLVMContext::MD_unpredictable)268k
)
5979
32.5k
    return false;
5980
268k
5981
268k
  TargetLowering::SelectSupportKind SelectKind;
5982
268k
  if (VectorCond)
5983
0
    SelectKind = TargetLowering::VectorMaskSelect;
5984
268k
  else if (SI->getType()->isVectorTy())
5985
840
    SelectKind = TargetLowering::ScalarCondVectorVal;
5986
268k
  else
5987
268k
    SelectKind = TargetLowering::ScalarValSelect;
5988
268k
5989
268k
  if (TLI->isSelectSupported(SelectKind) &&
5990
268k
      
!isFormingBranchFromSelectProfitable(TTI, TLI, SI)268k
)
5991
268k
    return false;
5992
149
5993
149
  // The DominatorTree needs to be rebuilt by any consumers after this
5994
149
  // transformation. We simply reset here rather than setting the ModifiedDT
5995
149
  // flag to avoid restarting the function walk in runOnFunction for each
5996
149
  // select optimized.
5997
149
  DT.reset();
5998
149
5999
149
  // Transform a sequence like this:
6000
149
  //    start:
6001
149
  //       %cmp = cmp uge i32 %a, %b
6002
149
  //       %sel = select i1 %cmp, i32 %c, i32 %d
6003
149
  //
6004
149
  // Into:
6005
149
  //    start:
6006
149
  //       %cmp = cmp uge i32 %a, %b
6007
149
  //       br i1 %cmp, label %select.true, label %select.false
6008
149
  //    select.true:
6009
149
  //       br label %select.end
6010
149
  //    select.false:
6011
149
  //       br label %select.end
6012
149
  //    select.end:
6013
149
  //       %sel = phi i32 [ %c, %select.true ], [ %d, %select.false ]
6014
149
  //
6015
149
  // In addition, we may sink instructions that produce %c or %d from
6016
149
  // the entry block into the destination(s) of the new branch.
6017
149
  // If the true or false blocks do not contain a sunken instruction, that
6018
149
  // block and its branch may be optimized away. In that case, one side of the
6019
149
  // first branch will point directly to select.end, and the corresponding PHI
6020
149
  // predecessor block will be the start block.
6021
149
6022
149
  // First, we split the block containing the select into 2 blocks.
6023
149
  BasicBlock *StartBlock = SI->getParent();
6024
149
  BasicBlock::iterator SplitPt = ++(BasicBlock::iterator(LastSI));
6025
149
  BasicBlock *EndBlock = StartBlock->splitBasicBlock(SplitPt, "select.end");
6026
149
6027
149
  // Delete the unconditional branch that was just created by the split.
6028
149
  StartBlock->getTerminator()->eraseFromParent();
6029
149
6030
149
  // These are the new basic blocks for the conditional branch.
6031
149
  // At least one will become an actual new basic block.
6032
149
  BasicBlock *TrueBlock = nullptr;
6033
149
  BasicBlock *FalseBlock = nullptr;
6034
149
  BranchInst *TrueBranch = nullptr;
6035
149
  BranchInst *FalseBranch = nullptr;
6036
149
6037
149
  // Sink expensive instructions into the conditional blocks to avoid executing
6038
149
  // them speculatively.
6039
151
  for (SelectInst *SI : ASI) {
6040
151
    if (sinkSelectOperand(TTI, SI->getTrueValue())) {
6041
26
      if (TrueBlock == nullptr) {
6042
26
        TrueBlock = BasicBlock::Create(SI->getContext(), "select.true.sink",
6043
26
                                       EndBlock->getParent(), EndBlock);
6044
26
        TrueBranch = BranchInst::Create(EndBlock, TrueBlock);
6045
26
        TrueBranch->setDebugLoc(SI->getDebugLoc());
6046
26
      }
6047
26
      auto *TrueInst = cast<Instruction>(SI->getTrueValue());
6048
26
      TrueInst->moveBefore(TrueBranch);
6049
26
    }
6050
151
    if (sinkSelectOperand(TTI, SI->getFalseValue())) {
6051
5
      if (FalseBlock == nullptr) {
6052
5
        FalseBlock = BasicBlock::Create(SI->getContext(), "select.false.sink",
6053
5
                                        EndBlock->getParent(), EndBlock);
6054
5
        FalseBranch = BranchInst::Create(EndBlock, FalseBlock);
6055
5
        FalseBranch->setDebugLoc(SI->getDebugLoc());
6056
5
      }
6057
5
      auto *FalseInst = cast<Instruction>(SI->getFalseValue());
6058
5
      FalseInst->moveBefore(FalseBranch);
6059
5
    }
6060
151
  }
6061
149
6062
149
  // If there was nothing to sink, then arbitrarily choose the 'false' side
6063
149
  // for a new input value to the PHI.
6064
149
  if (TrueBlock == FalseBlock) {
6065
120
    assert(TrueBlock == nullptr &&
6066
120
           "Unexpected basic block transform while optimizing select");
6067
120
6068
120
    FalseBlock = BasicBlock::Create(SI->getContext(), "select.false",
6069
120
                                    EndBlock->getParent(), EndBlock);
6070
120
    auto *FalseBranch = BranchInst::Create(EndBlock, FalseBlock);
6071
120
    FalseBranch->setDebugLoc(SI->getDebugLoc());
6072
120
  }
6073
149
6074
149
  // Insert the real conditional branch based on the original condition.
6075
149
  // If we did not create a new block for one of the 'true' or 'false' paths
6076
149
  // of the condition, it means that side of the branch goes to the end block
6077
149
  // directly and the path originates from the start block from the point of
6078
149
  // view of the new PHI.
6079
149
  BasicBlock *TT, *FT;
6080
149
  if (TrueBlock == nullptr) {
6081
123
    TT = EndBlock;
6082
123
    FT = FalseBlock;
6083
123
    TrueBlock = StartBlock;
6084
123
  } else 
if (26
FalseBlock == nullptr26
) {
6085
24
    TT = TrueBlock;
6086
24
    FT = EndBlock;
6087
24
    FalseBlock = StartBlock;
6088
24
  } else {
6089
2
    TT = TrueBlock;
6090
2
    FT = FalseBlock;
6091
2
  }
6092
149
  IRBuilder<>(SI).CreateCondBr(SI->getCondition(), TT, FT, SI);
6093
149
6094
149
  SmallPtrSet<const Instruction *, 2> INS;
6095
149
  INS.insert(ASI.begin(), ASI.end());
6096
149
  // Use reverse iterator because later select may use the value of the
6097
149
  // earlier select, and we need to propagate value through earlier select
6098
149
  // to get the PHI operand.
6099
300
  for (auto It = ASI.rbegin(); It != ASI.rend(); 
++It151
) {
6100
151
    SelectInst *SI = *It;
6101
151
    // The select itself is replaced with a PHI Node.
6102
151
    PHINode *PN = PHINode::Create(SI->getType(), 2, "", &EndBlock->front());
6103
151
    PN->takeName(SI);
6104
151
    PN->addIncoming(getTrueOrFalseValue(SI, true, INS), TrueBlock);
6105
151
    PN->addIncoming(getTrueOrFalseValue(SI, false, INS), FalseBlock);
6106
151
    PN->setDebugLoc(SI->getDebugLoc());
6107
151
6108
151
    SI->replaceAllUsesWith(PN);
6109
151
    SI->eraseFromParent();
6110
151
    INS.erase(SI);
6111
151
    ++NumSelectsExpanded;
6112
151
  }
6113
149
6114
149
  // Instruct OptimizeBlock to skip to the next block.
6115
149
  CurInstIterator = StartBlock->end();
6116
149
  return true;
6117
149
}
6118
6119
23.4k
static bool isBroadcastShuffle(ShuffleVectorInst *SVI) {
6120
23.4k
  SmallVector<int, 16> Mask(SVI->getShuffleMask());
6121
23.4k
  int SplatElem = -1;
6122
90.5k
  for (unsigned i = 0; i < Mask.size(); 
++i67.0k
) {
6123
85.6k
    if (SplatElem != -1 && 
Mask[i] != -132.7k
&&
Mask[i] != SplatElem29.5k
)
6124
18.6k
      return false;
6125
67.0k
    SplatElem = Mask[i];
6126
67.0k
  }
6127
23.4k
6128
23.4k
  
return true4.84k
;
6129
23.4k
}
6130
6131
/// Some targets have expensive vector shifts if the lanes aren't all the same
6132
/// (e.g. x86 only introduced "vpsllvd" and friends with AVX2). In these cases
6133
/// it's often worth sinking a shufflevector splat down to its use so that
6134
/// codegen can spot all lanes are identical.
6135
230k
bool CodeGenPrepare::optimizeShuffleVectorInst(ShuffleVectorInst *SVI) {
6136
230k
  BasicBlock *DefBB = SVI->getParent();
6137
230k
6138
230k
  // Only do this xform if variable vector shifts are particularly expensive.
6139
230k
  if (!TLI || !TLI->isVectorShiftByScalarCheap(SVI->getType()))
6140
207k
    return false;
6141
23.4k
6142
23.4k
  // We only expect better codegen by sinking a shuffle if we can recognise a
6143
23.4k
  // constant splat.
6144
23.4k
  if (!isBroadcastShuffle(SVI))
6145
18.6k
    return false;
6146
4.84k
6147
4.84k
  // InsertedShuffles - Only insert a shuffle in each block once.
6148
4.84k
  DenseMap<BasicBlock*, Instruction*> InsertedShuffles;
6149
4.84k
6150
4.84k
  bool MadeChange = false;
6151
5.72k
  for (User *U : SVI->users()) {
6152
5.72k
    Instruction *UI = cast<Instruction>(U);
6153
5.72k
6154
5.72k
    // Figure out which BB this ext is used in.
6155
5.72k
    BasicBlock *UserBB = UI->getParent();
6156
5.72k
    if (UserBB == DefBB) 
continue5.39k
;
6157
327
6158
327
    // For now only apply this when the splat is used by a shift instruction.
6159
327
    if (!UI->isShift()) 
continue295
;
6160
32
6161
32
    // Everything checks out, sink the shuffle if the user's block doesn't
6162
32
    // already have a copy.
6163
32
    Instruction *&InsertedShuffle = InsertedShuffles[UserBB];
6164
32
6165
32
    if (!InsertedShuffle) {
6166
32
      BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt();
6167
32
      assert(InsertPt != UserBB->end());
6168
32
      InsertedShuffle =
6169
32
          new ShuffleVectorInst(SVI->getOperand(0), SVI->getOperand(1),
6170
32
                                SVI->getOperand(2), "", &*InsertPt);
6171
32
      InsertedShuffle->setDebugLoc(SVI->getDebugLoc());
6172
32
    }
6173
32
6174
32
    UI->replaceUsesOfWith(SVI, InsertedShuffle);
6175
32
    MadeChange = true;
6176
32
  }
6177
4.84k
6178
4.84k
  // If we removed all uses, nuke the shuffle.
6179
4.84k
  if (SVI->use_empty()) {
6180
6
    SVI->eraseFromParent();
6181
6
    MadeChange = true;
6182
6
  }
6183
4.84k
6184
4.84k
  return MadeChange;
6185
4.84k
}
6186
6187
18.4M
bool CodeGenPrepare::tryToSinkFreeOperands(Instruction *I) {
6188
18.4M
  // If the operands of I can be folded into a target instruction together with
6189
18.4M
  // I, duplicate and sink them.
6190
18.4M
  SmallVector<Use *, 4> OpsToSink;
6191
18.4M
  if (!TLI || 
!TLI->shouldSinkOperands(I, OpsToSink)18.4M
)
6192
18.4M
    return false;
6193
2.42k
6194
2.42k
  // OpsToSink can contain multiple uses in a use chain (e.g.
6195
2.42k
  // (%u1 with %u1 = shufflevector), (%u2 with %u2 = zext %u1)). The dominating
6196
2.42k
  // uses must come first, which means they are sunk first, temporarily creating
6197
2.42k
  // invalid IR. This will be fixed once their dominated users are sunk and
6198
2.42k
  // updated.
6199
2.42k
  BasicBlock *TargetBB = I->getParent();
6200
2.42k
  bool Changed = false;
6201
2.42k
  SmallVector<Use *, 4> ToReplace;
6202
4.83k
  for (Use *U : OpsToSink) {
6203
4.83k
    auto *UI = cast<Instruction>(U->get());
6204
4.83k
    if (UI->getParent() == TargetBB || 
isa<PHINode>(UI)18
)
6205
4.81k
      continue;
6206
18
    ToReplace.push_back(U);
6207
18
  }
6208
2.42k
6209
2.42k
  SmallPtrSet<Instruction *, 4> MaybeDead;
6210
2.42k
  for (Use *U : ToReplace) {
6211
18
    auto *UI = cast<Instruction>(U->get());
6212
18
    Instruction *NI = UI->clone();
6213
18
    MaybeDead.insert(UI);
6214
18
    LLVM_DEBUG(dbgs() << "Sinking " << *UI << " to user " << *I << "\n");
6215
18
    NI->insertBefore(I);
6216
18
    InsertedInsts.insert(NI);
6217
18
    U->set(NI);
6218
18
    Changed = true;
6219
18
  }
6220
2.42k
6221
2.42k
  // Remove instructions that are dead after sinking.
6222
2.42k
  for (auto *I : MaybeDead)
6223
18
    if (!I->hasNUsesOrMore(1))
6224
12
      I->eraseFromParent();
6225
2.42k
6226
2.42k
  return Changed;
6227
2.42k
}
6228
6229
39.3k
bool CodeGenPrepare::optimizeSwitchInst(SwitchInst *SI) {
6230
39.3k
  if (!TLI || 
!DL39.3k
)
6231
4
    return false;
6232
39.3k
6233
39.3k
  Value *Cond = SI->getCondition();
6234
39.3k
  Type *OldType = Cond->getType();
6235
39.3k
  LLVMContext &Context = Cond->getContext();
6236
39.3k
  MVT RegType = TLI->getRegisterType(Context, TLI->getValueType(*DL, OldType));
6237
39.3k
  unsigned RegWidth = RegType.getSizeInBits();
6238
39.3k
6239
39.3k
  if (RegWidth <= cast<IntegerType>(OldType)->getBitWidth())
6240
30.5k
    return false;
6241
8.78k
6242
8.78k
  // If the register width is greater than the type width, expand the condition
6243
8.78k
  // of the switch instruction and each case constant to the width of the
6244
8.78k
  // register. By widening the type of the switch condition, subsequent
6245
8.78k
  // comparisons (for case comparisons) will not need to be extended to the
6246
8.78k
  // preferred register width, so we will potentially eliminate N-1 extends,
6247
8.78k
  // where N is the number of cases in the switch.
6248
8.78k
  auto *NewType = Type::getIntNTy(Context, RegWidth);
6249
8.78k
6250
8.78k
  // Zero-extend the switch condition and case constants unless the switch
6251
8.78k
  // condition is a function argument that is already being sign-extended.
6252
8.78k
  // In that case, we can avoid an unnecessary mask/extension by sign-extending
6253
8.78k
  // everything instead.
6254
8.78k
  Instruction::CastOps ExtType = Instruction::ZExt;
6255
8.78k
  if (auto *Arg = dyn_cast<Argument>(Cond))
6256
39
    if (Arg->hasSExtAttr())
6257
16
      ExtType = Instruction::SExt;
6258
8.78k
6259
8.78k
  auto *ExtInst = CastInst::Create(ExtType, Cond, NewType);
6260
8.78k
  ExtInst->insertBefore(SI);
6261
8.78k
  ExtInst->setDebugLoc(SI->getDebugLoc());
6262
8.78k
  SI->setCondition(ExtInst);
6263
25.2k
  for (auto Case : SI->cases()) {
6264
25.2k
    APInt NarrowConst = Case.getCaseValue()->getValue();
6265
25.2k
    APInt WideConst = (ExtType == Instruction::ZExt) ?
6266
25.1k
                      NarrowConst.zext(RegWidth) : 
NarrowConst.sext(RegWidth)69
;
6267
25.2k
    Case.setValue(ConstantInt::get(Context, WideConst));
6268
25.2k
  }
6269
8.78k
6270
8.78k
  return true;
6271
8.78k
}
6272
6273
6274
namespace {
6275
6276
/// Helper class to promote a scalar operation to a vector one.
6277
/// This class is used to move downward extractelement transition.
6278
/// E.g.,
6279
/// a = vector_op <2 x i32>
6280
/// b = extractelement <2 x i32> a, i32 0
6281
/// c = scalar_op b
6282
/// store c
6283
///
6284
/// =>
6285
/// a = vector_op <2 x i32>
6286
/// c = vector_op a (equivalent to scalar_op on the related lane)
6287
/// * d = extractelement <2 x i32> c, i32 0
6288
/// * store d
6289
/// Assuming both extractelement and store can be combine, we get rid of the
6290
/// transition.
6291
class VectorPromoteHelper {
6292
  /// DataLayout associated with the current module.
6293
  const DataLayout &DL;
6294
6295
  /// Used to perform some checks on the legality of vector operations.
6296
  const TargetLowering &TLI;
6297
6298
  /// Used to estimated the cost of the promoted chain.
6299
  const TargetTransformInfo &TTI;
6300
6301
  /// The transition being moved downwards.
6302
  Instruction *Transition;
6303
6304
  /// The sequence of instructions to be promoted.
6305
  SmallVector<Instruction *, 4> InstsToBePromoted;
6306
6307
  /// Cost of combining a store and an extract.
6308
  unsigned StoreExtractCombineCost;
6309
6310
  /// Instruction that will be combined with the transition.
6311
  Instruction *CombineInst = nullptr;
6312
6313
  /// The instruction that represents the current end of the transition.
6314
  /// Since we are faking the promotion until we reach the end of the chain
6315
  /// of computation, we need a way to get the current end of the transition.
6316
117
  Instruction *getEndOfTransition() const {
6317
117
    if (InstsToBePromoted.empty())
6318
81
      return Transition;
6319
36
    return InstsToBePromoted.back();
6320
36
  }
6321
6322
  /// Return the index of the original value in the transition.
6323
  /// E.g., for "extractelement <2 x i32> c, i32 1" the original value,
6324
  /// c, is at index 0.
6325
194
  unsigned getTransitionOriginalValueIdx() const {
6326
194
    assert(isa<ExtractElementInst>(Transition) &&
6327
194
           "Other kind of transitions are not supported yet");
6328
194
    return 0;
6329
194
  }
6330
6331
  /// Return the index of the index in the transition.
6332
  /// E.g., for "extractelement <2 x i32> c, i32 0" the index
6333
  /// is at index 1.
6334
32
  unsigned getTransitionIdx() const {
6335
32
    assert(isa<ExtractElementInst>(Transition) &&
6336
32
           "Other kind of transitions are not supported yet");
6337
32
    return 1;
6338
32
  }
6339
6340
  /// Get the type of the transition.
6341
  /// This is the type of the original value.
6342
  /// E.g., for "extractelement <2 x i32> c, i32 1" the type of the
6343
  /// transition is <2 x i32>.
6344
112
  Type *getTransitionType() const {
6345
112
    return Transition->getOperand(getTransitionOriginalValueIdx())->getType();
6346
112
  }
6347
6348
  /// Promote \p ToBePromoted by moving \p Def downward through.
6349
  /// I.e., we have the following sequence:
6350
  /// Def = Transition <ty1> a to <ty2>
6351
  /// b = ToBePromoted <ty2> Def, ...
6352
  /// =>
6353
  /// b = ToBePromoted <ty1> a, ...
6354
  /// Def = Transition <ty1> ToBePromoted to <ty2>
6355
  void promoteImpl(Instruction *ToBePromoted);
6356
6357
  /// Check whether or not it is profitable to promote all the
6358
  /// instructions enqueued to be promoted.
6359
6
  bool isProfitableToPromote() {
6360
6
    Value *ValIdx = Transition->getOperand(getTransitionOriginalValueIdx());
6361
6
    unsigned Index = isa<ConstantInt>(ValIdx)
6362
6
                         ? 
cast<ConstantInt>(ValIdx)->getZExtValue()0
6363
6
                         : -1;
6364
6
    Type *PromotedType = getTransitionType();
6365
6
6366
6
    StoreInst *ST = cast<StoreInst>(CombineInst);
6367
6
    unsigned AS = ST->getPointerAddressSpace();
6368
6
    unsigned Align = ST->getAlignment();
6369
6
    // Check if this store is supported.
6370
6
    if (!TLI.allowsMisalignedMemoryAccesses(
6371
6
            TLI.getValueType(DL, ST->getValueOperand()->getType()), AS,
6372
6
            Align)) {
6373
0
      // If this is not supported, there is no way we can combine
6374
0
      // the extract with the store.
6375
0
      return false;
6376
0
    }
6377
6
6378
6
    // The scalar chain of computation has to pay for the transition
6379
6
    // scalar to vector.
6380
6
    // The vector chain has to account for the combining cost.
6381
6
    uint64_t ScalarCost =
6382
6
        TTI.getVectorInstrCost(Transition->getOpcode(), PromotedType, Index);
6383
6
    uint64_t VectorCost = StoreExtractCombineCost;
6384
18
    for (const auto &Inst : InstsToBePromoted) {
6385
18
      // Compute the cost.
6386
18
      // By construction, all instructions being promoted are arithmetic ones.
6387
18
      // Moreover, one argument is a constant that can be viewed as a splat
6388
18
      // constant.
6389
18
      Value *Arg0 = Inst->getOperand(0);
6390
18
      bool IsArg0Constant = isa<UndefValue>(Arg0) || isa<ConstantInt>(Arg0) ||
6391
18
                            isa<ConstantFP>(Arg0);
6392
18
      TargetTransformInfo::OperandValueKind Arg0OVK =
6393
18
          IsArg0Constant ? 
TargetTransformInfo::OK_UniformConstantValue0
6394
18
                         : TargetTransformInfo::OK_AnyValue;
6395
18
      TargetTransformInfo::OperandValueKind Arg1OVK =
6396
18
          !IsArg0Constant ? TargetTransformInfo::OK_UniformConstantValue
6397
18
                          : 
TargetTransformInfo::OK_AnyValue0
;
6398
18
      ScalarCost += TTI.getArithmeticInstrCost(
6399
18
          Inst->getOpcode(), Inst->getType(), Arg0OVK, Arg1OVK);
6400
18
      VectorCost += TTI.getArithmeticInstrCost(Inst->getOpcode(), PromotedType,
6401
18
                                               Arg0OVK, Arg1OVK);
6402
18
    }
6403
6
    LLVM_DEBUG(
6404
6
        dbgs() << "Estimated cost of computation to be promoted:\nScalar: "
6405
6
               << ScalarCost << "\nVector: " << VectorCost << '\n');
6406
6
    return ScalarCost > VectorCost;
6407
6
  }
6408
6409
  /// Generate a constant vector with \p Val with the same
6410
  /// number of elements as the transition.
6411
  /// \p UseSplat defines whether or not \p Val should be replicated
6412
  /// across the whole vector.
6413
  /// In other words, if UseSplat == true, we generate <Val, Val, ..., Val>,
6414
  /// otherwise we generate a vector with as many undef as possible:
6415
  /// <undef, ..., undef, Val, undef, ..., undef> where \p Val is only
6416
  /// used at the index of the extract.
6417
38
  Value *getConstantVector(Constant *Val, bool UseSplat) const {
6418
38
    unsigned ExtractIdx = std::numeric_limits<unsigned>::max();
6419
38
    if (!UseSplat) {
6420
32
      // If we cannot determine where the constant must be, we have to
6421
32
      // use a splat constant.
6422
32
      Value *ValExtractIdx = Transition->getOperand(getTransitionIdx());
6423
32
      if (ConstantInt *CstVal = dyn_cast<ConstantInt>(ValExtractIdx))
6424
31
        ExtractIdx = CstVal->getSExtValue();
6425
1
      else
6426
1
        UseSplat = true;
6427
32
    }
6428
38
6429
38
    unsigned End = getTransitionType()->getVectorNumElements();
6430
38
    if (UseSplat)
6431
7
      return ConstantVector::getSplat(End, Val);
6432
31
6433
31
    SmallVector<Constant *, 4> ConstVec;
6434
31
    UndefValue *UndefVal = UndefValue::get(Val->getType());
6435
105
    for (unsigned Idx = 0; Idx != End; 
++Idx74
) {
6436
74
      if (Idx == ExtractIdx)
6437
31
        ConstVec.push_back(Val);
6438
43
      else
6439
43
        ConstVec.push_back(UndefVal);
6440
74
    }
6441
31
    return ConstantVector::get(ConstVec);
6442
31
  }
6443
6444
  /// Check if promoting to a vector type an operand at \p OperandIdx
6445
  /// in \p Use can trigger undefined behavior.
6446
  static bool canCauseUndefinedBehavior(const Instruction *Use,
6447
96
                                        unsigned OperandIdx) {
6448
96
    // This is not safe to introduce undef when the operand is on
6449
96
    // the right hand side of a division-like instruction.
6450
96
    if (OperandIdx != 1)
6451
52
      return false;
6452
44
    switch (Use->getOpcode()) {
6453
44
    default:
6454
30
      return false;
6455
44
    case Instruction::SDiv:
6456
10
    case Instruction::UDiv:
6457
10
    case Instruction::SRem:
6458
10
    case Instruction::URem:
6459
10
      return true;
6460
10
    case Instruction::FDiv:
6461
4
    case Instruction::FRem:
6462
4
      return !Use->hasNoNaNs();
6463
0
    }
6464
0
    llvm_unreachable(nullptr);
6465
0
  }
6466
6467
public:
6468
  VectorPromoteHelper(const DataLayout &DL, const TargetLowering &TLI,
6469
                      const TargetTransformInfo &TTI, Instruction *Transition,
6470
                      unsigned CombineCost)
6471
      : DL(DL), TLI(TLI), TTI(TTI), Transition(Transition),
6472
218
        StoreExtractCombineCost(CombineCost) {
6473
218
    assert(Transition && "Do not know how to promote null");
6474
218
  }
6475
6476
  /// Check if we can promote \p ToBePromoted to \p Type.
6477
95
  bool canPromote(const Instruction *ToBePromoted) const {
6478
95
    // We could support CastInst too.
6479
95
    return isa<BinaryOperator>(ToBePromoted);
6480
95
  }
6481
6482
  /// Check if it is profitable to promote \p ToBePromoted
6483
  /// by moving downward the transition through.
6484
59
  bool shouldPromote(const Instruction *ToBePromoted) const {
6485
59
    // Promote only if all the operands can be statically expanded.
6486
59
    // Indeed, we do not want to introduce any new kind of transitions.
6487
117
    for (const Use &U : ToBePromoted->operands()) {
6488
117
      const Value *Val = U.get();
6489
117
      if (Val == getEndOfTransition()) {
6490
58
        // If the use is a division and the transition is on the rhs,
6491
58
        // we cannot promote the operation, otherwise we may create a
6492
58
        // division by zero.
6493
58
        if (canCauseUndefinedBehavior(ToBePromoted, U.getOperandNo()))
6494
6
          return false;
6495
52
        continue;
6496
52
      }
6497
59
      if (!isa<ConstantInt>(Val) && 
!isa<UndefValue>(Val)7
&&
6498
59
          
!isa<ConstantFP>(Val)7
)
6499
2
        return false;
6500
59
    }
6501
59
    // Check that the resulting operation is legal.
6502
59
    int ISDOpcode = TLI.InstructionOpcodeToISD(ToBePromoted->getOpcode());
6503
51
    if (!ISDOpcode)
6504
0
      return false;
6505
51
    return StressStoreExtract ||
6506
51
           TLI.isOperationLegalOrCustom(
6507
30
               ISDOpcode, TLI.getValueType(DL, getTransitionType(), true));
6508
51
  }
6509
6510
  /// Check whether or not \p Use can be combined
6511
  /// with the transition.
6512
  /// I.e., is it possible to do Use(Transition) => AnotherUse?
6513
168
  bool canCombine(const Instruction *Use) { return isa<StoreInst>(Use); }
6514
6515
  /// Record \p ToBePromoted as part of the chain to be promoted.
6516
41
  void enqueueForPromotion(Instruction *ToBePromoted) {
6517
41
    InstsToBePromoted.push_back(ToBePromoted);
6518
41
  }
6519
6520
  /// Set the instruction that will be combined with the transition.
6521
73
  void recordCombineInstruction(Instruction *ToBeCombined) {
6522
73
    assert(canCombine(ToBeCombined) && "Unsupported instruction to combine");
6523
73
    CombineInst = ToBeCombined;
6524
73
  }
6525
6526
  /// Promote all the instructions enqueued for promotion if it is
6527
  /// is profitable.
6528
  /// \return True if the promotion happened, false otherwise.
6529
73
  bool promote() {
6530
73
    // Check if there is something to promote.
6531
73
    // Right now, if we do not have anything to combine with,
6532
73
    // we assume the promotion is not profitable.
6533
73
    if (InstsToBePromoted.empty() || 
!CombineInst20
)
6534
53
      return false;
6535
20
6536
20
    // Check cost.
6537
20
    if (!StressStoreExtract && 
!isProfitableToPromote()6
)
6538
0
      return false;
6539
20
6540
20
    // Promote.
6541
20
    for (auto &ToBePromoted : InstsToBePromoted)
6542
38
      promoteImpl(ToBePromoted);
6543
20
    InstsToBePromoted.clear();
6544
20
    return true;
6545
20
  }
6546
};
6547
6548
} // end anonymous namespace
6549
6550
38
void VectorPromoteHelper::promoteImpl(Instruction *ToBePromoted) {
6551
38
  // At this point, we know that all the operands of ToBePromoted but Def
6552
38
  // can be statically promoted.
6553
38
  // For Def, we need to use its parameter in ToBePromoted:
6554
38
  // b = ToBePromoted ty1 a
6555
38
  // Def = Transition ty1 b to ty2
6556
38
  // Move the transition down.
6557
38
  // 1. Replace all uses of the promoted operation by the transition.
6558
38
  // = ... b => = ... Def.
6559
38
  assert(ToBePromoted->getType() == Transition->getType() &&
6560
38
         "The type of the result of the transition does not match "
6561
38
         "the final type");
6562
38
  ToBePromoted->replaceAllUsesWith(Transition);
6563
38
  // 2. Update the type of the uses.
6564
38
  // b = ToBePromoted ty2 Def => b = ToBePromoted ty1 Def.
6565
38
  Type *TransitionTy = getTransitionType();
6566
38
  ToBePromoted->mutateType(TransitionTy);
6567
38
  // 3. Update all the operands of the promoted operation with promoted
6568
38
  // operands.
6569
38
  // b = ToBePromoted ty1 Def => b = ToBePromoted ty1 a.
6570
76
  for (Use &U : ToBePromoted->operands()) {
6571
76
    Value *Val = U.get();
6572
76
    Value *NewVal = nullptr;
6573
76
    if (Val == Transition)
6574
38
      NewVal = Transition->getOperand(getTransitionOriginalValueIdx());
6575
38
    else if (isa<UndefValue>(Val) || isa<ConstantInt>(Val) ||
6576
38
             
isa<ConstantFP>(Val)5
) {
6577
38
      // Use a splat constant if it is not safe to use undef.
6578
38
      NewVal = getConstantVector(
6579
38
          cast<Constant>(Val),
6580
38
          isa<UndefValue>(Val) ||
6581
38
              canCauseUndefinedBehavior(ToBePromoted, U.getOperandNo()));
6582
38
    } else
6583
38
      
llvm_unreachable0
("Did you modified shouldPromote and forgot to update "
6584
76
                       "this?");
6585
76
    ToBePromoted->setOperand(U.getOperandNo(), NewVal);
6586
76
  }
6587
38
  Transition->moveAfter(ToBePromoted);
6588
38
  Transition->setOperand(getTransitionOriginalValueIdx(), ToBePromoted);
6589
38
}
6590
6591
/// Some targets can do store(extractelement) with one instruction.
6592
/// Try to push the extractelement towards the stores when the target
6593
/// has this feature and this is profitable.
6594
67.4k
bool CodeGenPrepare::optimizeExtractElementInst(Instruction *Inst) {
6595
67.4k
  unsigned CombineCost = std::numeric_limits<unsigned>::max();
6596
67.4k
  if (DisableStoreExtract || !TLI ||
6597
67.4k
      (!StressStoreExtract &&
6598
67.4k
       !TLI->canCombineStoreAndExtract(Inst->getOperand(0)->getType(),
6599
67.3k
                                       Inst->getOperand(1), CombineCost)))
6600
67.2k
    return false;
6601
218
6602
218
  // At this point we know that Inst is a vector to scalar transition.
6603
218
  // Try to move it down the def-use chain, until:
6604
218
  // - We can combine the transition with its single use
6605
218
  //   => we got rid of the transition.
6606
218
  // - We escape the current basic block
6607
218
  //   => we would need to check that we are moving it at a cheaper place and
6608
218
  //      we do not do that for now.
6609
218
  BasicBlock *Parent = Inst->getParent();
6610
218
  LLVM_DEBUG(dbgs() << "Found an interesting transition: " << *Inst << '\n');
6611
218
  VectorPromoteHelper VPH(*DL, *TLI, *TTI, Inst, CombineCost);
6612
218
  // If the transition has more than one use, assume this is not going to be
6613
218
  // beneficial.
6614
259
  while (Inst->hasOneUse()) {
6615
171
    Instruction *ToBePromoted = cast<Instruction>(*Inst->user_begin());
6616
171
    LLVM_DEBUG(dbgs() << "Use: " << *ToBePromoted << '\n');
6617
171
6618
171
    if (ToBePromoted->getParent() != Parent) {
6619
3
      LLVM_DEBUG(dbgs() << "Instruction to promote is in a different block ("
6620
3
                        << ToBePromoted->getParent()->getName()
6621
3
                        << ") than the transition (" << Parent->getName()
6622
3
                        << ").\n");
6623
3
      return false;
6624
3
    }
6625
168
6626
168
    if (VPH.canCombine(ToBePromoted)) {
6627
73
      LLVM_DEBUG(dbgs() << "Assume " << *Inst << '\n'
6628
73
                        << "will be combined with: " << *ToBePromoted << '\n');
6629
73
      VPH.recordCombineInstruction(ToBePromoted);
6630
73
      bool Changed = VPH.promote();
6631
73
      NumStoreExtractExposed += Changed;
6632
73
      return Changed;
6633
73
    }
6634
95
6635
95
    LLVM_DEBUG(dbgs() << "Try promoting.\n");
6636
95
    if (!VPH.canPromote(ToBePromoted) || 
!VPH.shouldPromote(ToBePromoted)59
)
6637
54
      return false;
6638
41
6639
41
    LLVM_DEBUG(dbgs() << "Promoting is possible... Enqueue for promotion!\n");
6640
41
6641
41
    VPH.enqueueForPromotion(ToBePromoted);
6642
41
    Inst = ToBePromoted;
6643
41
  }
6644
218
  
return false88
;
6645
218
}
6646
6647
/// For the instruction sequence of store below, F and I values
6648
/// are bundled together as an i64 value before being stored into memory.
6649
/// Sometimes it is more efficient to generate separate stores for F and I,
6650
/// which can remove the bitwise instructions or sink them to colder places.
6651
///
6652
///   (store (or (zext (bitcast F to i32) to i64),
6653
///              (shl (zext I to i64), 32)), addr)  -->
6654
///   (store F, addr) and (store I, addr+4)
6655
///
6656
/// Similarly, splitting for other merged store can also be beneficial, like:
6657
/// For pair of {i32, i32}, i64 store --> two i32 stores.
6658
/// For pair of {i32, i16}, i64 store --> two i32 stores.
6659
/// For pair of {i16, i16}, i32 store --> two i16 stores.
6660
/// For pair of {i16, i8},  i32 store --> two i16 stores.
6661
/// For pair of {i8, i8},   i16 store --> two i8 stores.
6662
///
6663
/// We allow each target to determine specifically which kind of splitting is
6664
/// supported.
6665
///
6666
/// The store patterns are commonly seen from the simple code snippet below
6667
/// if only std::make_pair(...) is sroa transformed before inlined into hoo.
6668
///   void goo(const std::pair<int, float> &);
6669
///   hoo() {
6670
///     ...
6671
///     goo(std::make_pair(tmp, ftmp));
6672
///     ...
6673
///   }
6674
///
6675
/// Although we already have similar splitting in DAG Combine, we duplicate
6676
/// it in CodeGenPrepare to catch the case in which pattern is across
6677
/// multiple BBs. The logic in DAG Combine is kept to catch case generated
6678
/// during code expansion.
6679
static bool splitMergedValStore(StoreInst &SI, const DataLayout &DL,
6680
4.05M
                                const TargetLowering &TLI) {
6681
4.05M
  // Handle simple but common cases only.
6682
4.05M
  Type *StoreType = SI.getValueOperand()->getType();
6683
4.05M
  if (!DL.typeSizeEqualsStoreSize(StoreType) ||
6684
4.05M
      
DL.getTypeSizeInBits(StoreType) == 04.02M
)
6685
27.2k
    return false;
6686
4.02M
6687
4.02M
  unsigned HalfValBitSize = DL.getTypeSizeInBits(StoreType) / 2;
6688
4.02M
  Type *SplitStoreType = Type::getIntNTy(SI.getContext(), HalfValBitSize);
6689
4.02M
  if (!DL.typeSizeEqualsStoreSize(SplitStoreType))
6690
360k
    return false;
6691
3.66M
6692
3.66M
  // Don't split the store if it is volatile.
6693
3.66M
  if (SI.isVolatile())
6694
22.1k
    return false;
6695
3.64M
6696
3.64M
  // Match the following patterns:
6697
3.64M
  // (store (or (zext LValue to i64),
6698
3.64M
  //            (shl (zext HValue to i64), 32)), HalfValBitSize)
6699
3.64M
  //  or
6700
3.64M
  // (store (or (shl (zext HValue to i64), 32)), HalfValBitSize)
6701
3.64M
  //            (zext LValue to i64),
6702
3.64M
  // Expect both operands of OR and the first operand of SHL have only
6703
3.64M
  // one use.
6704
3.64M
  Value *LValue, *HValue;
6705
3.64M
  if (!match(SI.getValueOperand(),
6706
3.64M
             m_c_Or(m_OneUse(m_ZExt(m_Value(LValue))),
6707
3.64M
                    m_OneUse(m_Shl(m_OneUse(m_ZExt(m_Value(HValue))),
6708
3.64M
                                   m_SpecificInt(HalfValBitSize))))))
6709
3.64M
    return false;
6710
802
6711
802
  // Check LValue and HValue are int with size less or equal than 32.
6712
802
  if (!LValue->getType()->isIntegerTy() ||
6713
802
      DL.getTypeSizeInBits(LValue->getType()) > HalfValBitSize ||
6714
802
      !HValue->getType()->isIntegerTy() ||
6715
802
      DL.getTypeSizeInBits(HValue->getType()) > HalfValBitSize)
6716
0
    return false;
6717
802
6718
802
  // If LValue/HValue is a bitcast instruction, use the EVT before bitcast
6719
802
  // as the input of target query.
6720
802
  auto *LBC = dyn_cast<BitCastInst>(LValue);
6721
802
  auto *HBC = dyn_cast<BitCastInst>(HValue);
6722
802
  EVT LowTy = LBC ? 
EVT::getEVT(LBC->getOperand(0)->getType())1
6723
802
                  : 
EVT::getEVT(LValue->getType())801
;
6724
802
  EVT HighTy = HBC ? 
EVT::getEVT(HBC->getOperand(0)->getType())6
6725
802
                   : 
EVT::getEVT(HValue->getType())796
;
6726
802
  if (!ForceSplitStore && 
!TLI.isMultiStoresCheaperThanBitsMerge(LowTy, HighTy)787
)
6727
787
    return false;
6728
15
6729
15
  // Start to split store.
6730
15
  IRBuilder<> Builder(SI.getContext());
6731
15
  Builder.SetInsertPoint(&SI);
6732
15
6733
15
  // If LValue/HValue is a bitcast in another BB, create a new one in current
6734
15
  // BB so it may be merged with the splitted stores by dag combiner.
6735
15
  if (LBC && 
LBC->getParent() != SI.getParent()1
)
6736
0
    LValue = Builder.CreateBitCast(LBC->getOperand(0), LBC->getType());
6737
15
  if (HBC && 
HBC->getParent() != SI.getParent()6
)
6738
3
    HValue = Builder.CreateBitCast(HBC->getOperand(0), HBC->getType());
6739
15
6740
15
  bool IsLE = SI.getModule()->getDataLayout().isLittleEndian();
6741
30
  auto CreateSplitStore = [&](Value *V, bool Upper) {
6742
30
    V = Builder.CreateZExtOrBitCast(V, SplitStoreType);
6743
30
    Value *Addr = Builder.CreateBitCast(
6744
30
        SI.getOperand(1),
6745
30
        SplitStoreType->getPointerTo(SI.getPointerAddressSpace()));
6746
30
    if ((IsLE && 
Upper28
) ||
(16
!IsLE16
&&
!Upper2
))
6747
15
      Addr = Builder.CreateGEP(
6748
15
          SplitStoreType, Addr,
6749
15
          ConstantInt::get(Type::getInt32Ty(SI.getContext()), 1));
6750
30
    Builder.CreateAlignedStore(
6751
30
        V, Addr, Upper ? 
SI.getAlignment() / 215
:
SI.getAlignment()15
);
6752
30
  };
6753
15
6754
15
  CreateSplitStore(LValue, false);
6755
15
  CreateSplitStore(HValue, true);
6756
15
6757
15
  // Delete the old store.
6758
15
  SI.eraseFromParent();
6759
15
  return true;
6760
15
}
6761
6762
// Return true if the GEP has two operands, the first operand is of a sequential
6763
// type, and the second operand is a constant.
6764
91
static bool GEPSequentialConstIndexed(GetElementPtrInst *GEP) {
6765
91
  gep_type_iterator I = gep_type_begin(*GEP);
6766
91
  return GEP->getNumOperands() == 2 &&
6767
91
      
I.isSequential()24
&&
6768
91
      
isa<ConstantInt>(GEP->getOperand(1))24
;
6769
91
}
6770
6771
// Try unmerging GEPs to reduce liveness interference (register pressure) across
6772
// IndirectBr edges. Since IndirectBr edges tend to touch on many blocks,
6773
// reducing liveness interference across those edges benefits global register
6774
// allocation. Currently handles only certain cases.
6775
//
6776
// For example, unmerge %GEPI and %UGEPI as below.
6777
//
6778
// ---------- BEFORE ----------
6779
// SrcBlock:
6780
//   ...
6781
//   %GEPIOp = ...
6782
//   ...
6783
//   %GEPI = gep %GEPIOp, Idx
6784
//   ...
6785
//   indirectbr ... [ label %DstB0, label %DstB1, ... label %DstBi ... ]
6786
//   (* %GEPI is alive on the indirectbr edges due to other uses ahead)
6787
//   (* %GEPIOp is alive on the indirectbr edges only because of it's used by
6788
//   %UGEPI)
6789
//
6790
// DstB0: ... (there may be a gep similar to %UGEPI to be unmerged)
6791
// DstB1: ... (there may be a gep similar to %UGEPI to be unmerged)
6792
// ...
6793
//
6794
// DstBi:
6795
//   ...
6796
//   %UGEPI = gep %GEPIOp, UIdx
6797
// ...
6798
// ---------------------------
6799
//
6800
// ---------- AFTER ----------
6801
// SrcBlock:
6802
//   ... (same as above)
6803
//    (* %GEPI is still alive on the indirectbr edges)
6804
//    (* %GEPIOp is no longer alive on the indirectbr edges as a result of the
6805
//    unmerging)
6806
// ...
6807
//
6808
// DstBi:
6809
//   ...
6810
//   %UGEPI = gep %GEPI, (UIdx-Idx)
6811
//   ...
6812
// ---------------------------
6813
//
6814
// The register pressure on the IndirectBr edges is reduced because %GEPIOp is
6815
// no longer alive on them.
6816
//
6817
// We try to unmerge GEPs here in CodGenPrepare, as opposed to limiting merging
6818
// of GEPs in the first place in InstCombiner::visitGetElementPtrInst() so as
6819
// not to disable further simplications and optimizations as a result of GEP
6820
// merging.
6821
//
6822
// Note this unmerging may increase the length of the data flow critical path
6823
// (the path from %GEPIOp to %UGEPI would go through %GEPI), which is a tradeoff
6824
// between the register pressure and the length of data-flow critical
6825
// path. Restricting this to the uncommon IndirectBr case would minimize the
6826
// impact of potentially longer critical path, if any, and the impact on compile
6827
// time.
6828
static bool tryUnmergingGEPsAcrossIndirectBr(GetElementPtrInst *GEPI,
6829
6.33M
                                             const TargetTransformInfo *TTI) {
6830
6.33M
  BasicBlock *SrcBlock = GEPI->getParent();
6831
6.33M
  // Check that SrcBlock ends with an IndirectBr. If not, give up. The common
6832
6.33M
  // (non-IndirectBr) cases exit early here.
6833
6.33M
  if (!isa<IndirectBrInst>(SrcBlock->getTerminator()))
6834
6.33M
    return false;
6835
88
  // Check that GEPI is a simple gep with a single constant index.
6836
88
  if (!GEPSequentialConstIndexed(GEPI))
6837
77
    return false;
6838
11
  ConstantInt *GEPIIdx = cast<ConstantInt>(GEPI->getOperand(1));
6839
11
  // Check that GEPI is a cheap one.
6840
11
  if (TTI->getIntImmCost(GEPIIdx->getValue(), GEPIIdx->getType())
6841
11
      > TargetTransformInfo::TCC_Basic)
6842
0
    return false;
6843
11
  Value *GEPIOp = GEPI->getOperand(0);
6844
11
  // Check that GEPIOp is an instruction that's also defined in SrcBlock.
6845
11
  if (!isa<Instruction>(GEPIOp))
6846
1
    return false;
6847
10
  auto *GEPIOpI = cast<Instruction>(GEPIOp);
6848
10
  if (GEPIOpI->getParent() != SrcBlock)
6849
0
    return false;
6850
10
  // Check that GEP is used outside the block, meaning it's alive on the
6851
10
  // IndirectBr edge(s).
6852
12
  
if (10
find_if(GEPI->users(), [&](User *Usr) 10
{
6853
12
        if (auto *I = dyn_cast<Instruction>(Usr)) {
6854
12
          if (I->getParent() != SrcBlock) {
6855
8
            return true;
6856
8
          }
6857
4
        }
6858
4
        return false;
6859
4
      }) == GEPI->users().end())
6860
2
    return false;
6861
8
  // The second elements of the GEP chains to be unmerged.
6862
8
  std::vector<GetElementPtrInst *> UGEPIs;
6863
8
  // Check each user of GEPIOp to check if unmerging would make GEPIOp not alive
6864
8
  // on IndirectBr edges.
6865
19
  for (User *Usr : GEPIOp->users()) {
6866
19
    if (Usr == GEPI) 
continue8
;
6867
11
    // Check if Usr is an Instruction. If not, give up.
6868
11
    if (!isa<Instruction>(Usr))
6869
0
      return false;
6870
11
    auto *UI = cast<Instruction>(Usr);
6871
11
    // Check if Usr in the same block as GEPIOp, which is fine, skip.
6872
11
    if (UI->getParent() == SrcBlock)
6873
8
      continue;
6874
3
    // Check if Usr is a GEP. If not, give up.
6875
3
    if (!isa<GetElementPtrInst>(Usr))
6876
0
      return false;
6877
3
    auto *UGEPI = cast<GetElementPtrInst>(Usr);
6878
3
    // Check if UGEPI is a simple gep with a single constant index and GEPIOp is
6879
3
    // the pointer operand to it. If so, record it in the vector. If not, give
6880
3
    // up.
6881
3
    if (!GEPSequentialConstIndexed(UGEPI))
6882
0
      return false;
6883
3
    if (UGEPI->getOperand(0) != GEPIOp)
6884
0
      return false;
6885
3
    if (GEPIIdx->getType() !=
6886
3
        cast<ConstantInt>(UGEPI->getOperand(1))->getType())
6887
0
      return false;
6888
3
    ConstantInt *UGEPIIdx = cast<ConstantInt>(UGEPI->getOperand(1));
6889
3
    if (TTI->getIntImmCost(UGEPIIdx->getValue(), UGEPIIdx->getType())
6890
3
        > TargetTransformInfo::TCC_Basic)
6891
0
      return false;
6892
3
    UGEPIs.push_back(UGEPI);
6893
3
  }
6894
8
  if (UGEPIs.size() == 0)
6895
7
    return false;
6896
1
  // Check the materializing cost of (Uidx-Idx).
6897
3
  
for (GetElementPtrInst *UGEPI : UGEPIs)1
{
6898
3
    ConstantInt *UGEPIIdx = cast<ConstantInt>(UGEPI->getOperand(1));
6899
3
    APInt NewIdx = UGEPIIdx->getValue() - GEPIIdx->getValue();
6900
3
    unsigned ImmCost = TTI->getIntImmCost(NewIdx, GEPIIdx->getType());
6901
3
    if (ImmCost > TargetTransformInfo::TCC_Basic)
6902
0
      return false;
6903
3
  }
6904
1
  // Now unmerge between GEPI and UGEPIs.
6905
3
  
for (GetElementPtrInst *UGEPI : UGEPIs)1
{
6906
3
    UGEPI->setOperand(0, GEPI);
6907
3
    ConstantInt *UGEPIIdx = cast<ConstantInt>(UGEPI->getOperand(1));
6908
3
    Constant *NewUGEPIIdx =
6909
3
        ConstantInt::get(GEPIIdx->getType(),
6910
3
                         UGEPIIdx->getValue() - GEPIIdx->getValue());
6911
3
    UGEPI->setOperand(1, NewUGEPIIdx);
6912
3
    // If GEPI is not inbounds but UGEPI is inbounds, change UGEPI to not
6913
3
    // inbounds to avoid UB.
6914
3
    if (!GEPI->isInBounds()) {
6915
3
      UGEPI->setIsInBounds(false);
6916
3
    }
6917
3
  }
6918
1
  // After unmerging, verify that GEPIOp is actually only used in SrcBlock (not
6919
1
  // alive on IndirectBr edges).
6920
1
  assert(find_if(GEPIOp->users(), [&](User *Usr) {
6921
1
        return cast<Instruction>(Usr)->getParent() != SrcBlock;
6922
1
      }) == GEPIOp->users().end() && "GEPIOp is used outside SrcBlock");
6923
1
  return true;
6924
1
}
6925
6926
40.9M
bool CodeGenPrepare::optimizeInst(Instruction *I, bool &ModifiedDT) {
6927
40.9M
  // Bail out if we inserted the instruction to prevent optimizations from
6928
40.9M
  // stepping on each other's toes.
6929
40.9M
  if (InsertedInsts.count(I))
6930
278k
    return false;
6931
40.7M
6932
40.7M
  // TODO: Move into the switch on opcode below here.
6933
40.7M
  if (PHINode *P = dyn_cast<PHINode>(I)) {
6934
1.76M
    // It is possible for very late stage optimizations (such as SimplifyCFG)
6935
1.76M
    // to introduce PHI nodes too late to be cleaned up.  If we detect such a
6936
1.76M
    // trivial PHI, go ahead and zap it here.
6937
1.76M
    if (Value *V = SimplifyInstruction(P, {*DL, TLInfo})) {
6938
625
      LargeOffsetGEPMap.erase(P);
6939
625
      P->replaceAllUsesWith(V);
6940
625
      P->eraseFromParent();
6941
625
      ++NumPHIsElim;
6942
625
      return true;
6943
625
    }
6944
1.75M
    return false;
6945
1.75M
  }
6946
38.9M
6947
38.9M
  if (CastInst *CI = dyn_cast<CastInst>(I)) {
6948
5.70M
    // If the source of the cast is a constant, then this should have
6949
5.70M
    // already been constant folded.  The only reason NOT to constant fold
6950
5.70M
    // it is if something (e.g. LSR) was careful to place the constant
6951
5.70M
    // evaluation in a block other than then one that uses it (e.g. to hoist
6952
5.70M
    // the address of globals out of a loop).  If this is the case, we don't
6953
5.70M
    // want to forward-subst the cast.
6954
5.70M
    if (isa<Constant>(CI->getOperand(0)))
6955
60.8k
      return false;
6956
5.64M
6957
5.64M
    if (TLI && 
OptimizeNoopCopyExpression(CI, *TLI, *DL)5.64M
)
6958
172k
      return true;
6959
5.47M
6960
5.47M
    if (isa<ZExtInst>(I) || 
isa<SExtInst>(I)5.13M
) {
6961
826k
      /// Sink a zext or sext into its user blocks if the target type doesn't
6962
826k
      /// fit in one register
6963
826k
      if (TLI &&
6964
826k
          TLI->getTypeAction(CI->getContext(),
6965
826k
                             TLI->getValueType(*DL, CI->getType())) ==
6966
826k
              TargetLowering::TypeExpandInteger) {
6967
18.6k
        return SinkCast(CI);
6968
808k
      } else {
6969
808k
        bool MadeChange = optimizeExt(I);
6970
808k
        return MadeChange | optimizeExtUses(I);
6971
808k
      }
6972
4.64M
    }
6973
4.64M
    return false;
6974
4.64M
  }
6975
33.2M
6976
33.2M
  if (auto *Cmp = dyn_cast<CmpInst>(I))
6977
3.64M
    if (TLI && 
optimizeCmp(Cmp, ModifiedDT)3.64M
)
6978
36.9k
      return true;
6979
33.2M
6980
33.2M
  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
6981
3.66M
    LI->setMetadata(LLVMContext::MD_invariant_group, nullptr);
6982
3.66M
    if (TLI) {
6983
3.66M
      bool Modified = optimizeLoadExt(LI);
6984
3.66M
      unsigned AS = LI->getPointerAddressSpace();
6985
3.66M
      Modified |= optimizeMemoryInst(I, I->getOperand(0), LI->getType(), AS);
6986
3.66M
      return Modified;
6987
3.66M
    }
6988
28
    return false;
6989
28
  }
6990
29.5M
6991
29.5M
  if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
6992
4.05M
    if (TLI && 
splitMergedValStore(*SI, *DL, *TLI)4.05M
)
6993
15
      return true;
6994
4.05M
    SI->setMetadata(LLVMContext::MD_invariant_group, nullptr);
6995
4.05M
    if (TLI) {
6996
4.05M
      unsigned AS = SI->getPointerAddressSpace();
6997
4.05M
      return optimizeMemoryInst(I, SI->getOperand(1),
6998
4.05M
                                SI->getOperand(0)->getType(), AS);
6999
4.05M
    }
7000
20
    return false;
7001
20
  }
7002
25.4M
7003
25.4M
  if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
7004
9.14k
      unsigned AS = RMW->getPointerAddressSpace();
7005
9.14k
      return optimizeMemoryInst(I, RMW->getPointerOperand(),
7006
9.14k
                                RMW->getType(), AS);
7007
9.14k
  }
7008
25.4M
7009
25.4M
  if (AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(I)) {
7010
3.87k
      unsigned AS = CmpX->getPointerAddressSpace();
7011
3.87k
      return optimizeMemoryInst(I, CmpX->getPointerOperand(),
7012
3.87k
                                CmpX->getCompareOperand()->getType(), AS);
7013
3.87k
  }
7014
25.4M
7015
25.4M
  BinaryOperator *BinOp = dyn_cast<BinaryOperator>(I);
7016
25.4M
7017
25.4M
  if (BinOp && 
(BinOp->getOpcode() == Instruction::And)3.94M
&&
7018
25.4M
      
EnableAndCmpSinking484k
&&
TLI484k
)
7019
484k
    return sinkAndCmp0Expression(BinOp, *TLI, InsertedInsts);
7020
24.9M
7021
24.9M
  // TODO: Move this into the switch on opcode - it handles shifts already.
7022
24.9M
  if (BinOp && 
(3.45M
BinOp->getOpcode() == Instruction::AShr3.45M
||
7023
3.45M
                
BinOp->getOpcode() == Instruction::LShr3.40M
)) {
7024
229k
    ConstantInt *CI = dyn_cast<ConstantInt>(BinOp->getOperand(1));
7025
229k
    if (TLI && 
CI229k
&&
TLI->hasExtractBitsInsn()193k
)
7026
138k
      if (OptimizeExtractBits(BinOp, CI, *TLI, *DL))
7027
1.59k
        return true;
7028
24.9M
  }
7029
24.9M
7030
24.9M
  if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(I)) {
7031
6.51M
    if (GEPI->hasAllZeroIndices()) {
7032
174k
      /// The GEP operand must be a pointer, so must its result -> BitCast
7033
174k
      Instruction *NC = new BitCastInst(GEPI->getOperand(0), GEPI->getType(),
7034
174k
                                        GEPI->getName(), GEPI);
7035
174k
      NC->setDebugLoc(GEPI->getDebugLoc());
7036
174k
      GEPI->replaceAllUsesWith(NC);
7037
174k
      GEPI->eraseFromParent();
7038
174k
      ++NumGEPsElim;
7039
174k
      optimizeInst(NC, ModifiedDT);
7040
174k
      return true;
7041
174k
    }
7042
6.33M
    if (tryUnmergingGEPsAcrossIndirectBr(GEPI, TTI)) {
7043
1
      return true;
7044
1
    }
7045
6.33M
    return false;
7046
6.33M
  }
7047
18.4M
7048
18.4M
  if (tryToSinkFreeOperands(I))
7049
18
    return true;
7050
18.4M
7051
18.4M
  switch (I->getOpcode()) {
7052
18.4M
  case Instruction::Shl:
7053
485k
  case Instruction::LShr:
7054
485k
  case Instruction::AShr:
7055
485k
    return optimizeShiftInst(cast<BinaryOperator>(I));
7056
4.03M
  case Instruction::Call:
7057
4.03M
    return optimizeCallInst(cast<CallInst>(I), ModifiedDT);
7058
485k
  case Instruction::Select:
7059
303k
    return optimizeSelectInst(cast<SelectInst>(I));
7060
485k
  case Instruction::ShuffleVector:
7061
230k
    return optimizeShuffleVectorInst(cast<ShuffleVectorInst>(I));
7062
485k
  case Instruction::Switch:
7063
39.3k
    return optimizeSwitchInst(cast<SwitchInst>(I));
7064
485k
  case Instruction::ExtractElement:
7065
67.4k
    return optimizeExtractElementInst(cast<ExtractElementInst>(I));
7066
13.3M
  }
7067
13.3M
7068
13.3M
  return false;
7069
13.3M
}
7070
7071
/// Given an OR instruction, check to see if this is a bitreverse
7072
/// idiom. If so, insert the new intrinsic and return true.
7073
static bool makeBitReverse(Instruction &I, const DataLayout &DL,
7074
41.2M
                           const TargetLowering &TLI) {
7075
41.2M
  if (!I.getType()->isIntegerTy() ||
7076
41.2M
      !TLI.isOperationLegalOrCustom(ISD::BITREVERSE,
7077
13.4M
                                    TLI.getValueType(DL, I.getType(), true)))
7078
33.5M
    return false;
7079
7.74M
7080
7.74M
  SmallVector<Instruction*, 4> Insts;
7081
7.74M
  if (!recognizeBSwapOrBitReverseIdiom(&I, false, true, Insts))
7082
7.74M
    return false;
7083
8
  Instruction *LastInst = Insts.back();
7084
8
  I.replaceAllUsesWith(LastInst);
7085
8
  RecursivelyDeleteTriviallyDeadInstructions(&I);
7086
8
  return true;
7087
8
}
7088
7089
// In this pass we look for GEP and cast instructions that are used
7090
// across basic blocks and rewrite them to improve basic-block-at-a-time
7091
// selection.
7092
6.33M
bool CodeGenPrepare::optimizeBlock(BasicBlock &BB, bool &ModifiedDT) {
7093
6.33M
  SunkAddrs.clear();
7094
6.33M
  bool MadeChange = false;
7095
6.33M
7096
6.33M
  CurInstIterator = BB.begin();
7097
47.1M
  while (CurInstIterator != BB.end()) {
7098
40.8M
    MadeChange |= optimizeInst(&*CurInstIterator++, ModifiedDT);
7099
40.8M
    if (ModifiedDT)
7100
3.02k
      return true;
7101
40.8M
  }
7102
6.33M
7103
6.33M
  bool MadeBitReverse = true;
7104
12.6M
  while (TLI && 
MadeBitReverse12.6M
) {
7105
6.33M
    MadeBitReverse = false;
7106
41.2M
    for (auto &I : reverse(BB)) {
7107
41.2M
      if (makeBitReverse(I, *DL, *TLI)) {
7108
9
        MadeBitReverse = MadeChange = true;
7109
9
        ModifiedDT = true;
7110
9
        break;
7111
9
      }
7112
41.2M
    }
7113
6.33M
  }
7114
6.33M
  MadeChange |= dupRetToEnableTailCallOpts(&BB, ModifiedDT);
7115
6.33M
7116
6.33M
  return MadeChange;
7117
6.33M
}
7118
7119
// llvm.dbg.value is far away from the value then iSel may not be able
7120
// handle it properly. iSel will drop llvm.dbg.value if it can not
7121
// find a node corresponding to the value.
7122
490k
bool CodeGenPrepare::placeDbgValues(Function &F) {
7123
490k
  bool MadeChange = false;
7124
2.55M
  for (BasicBlock &BB : F) {
7125
2.55M
    Instruction *PrevNonDbgInst = nullptr;
7126
17.9M
    for (BasicBlock::iterator BI = BB.begin(), BE = BB.end(); BI != BE;) {
7127
15.3M
      Instruction *Insn = &*BI++;
7128
15.3M
      DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn);
7129
15.3M
      // Leave dbg.values that refer to an alloca alone. These
7130
15.3M
      // intrinsics describe the address of a variable (= the alloca)
7131
15.3M
      // being taken.  They should not be moved next to the alloca
7132
15.3M
      // (and to the beginning of the scope), but rather stay close to
7133
15.3M
      // where said address is used.
7134
15.3M
      if (!DVI || 
(4.98k
DVI->getValue()4.98k
&&
isa<AllocaInst>(DVI->getValue())4.98k
)) {
7135
15.3M
        PrevNonDbgInst = Insn;
7136
15.3M
        continue;
7137
15.3M
      }
7138
4.92k
7139
4.92k
      Instruction *VI = dyn_cast_or_null<Instruction>(DVI->getValue());
7140
4.92k
      if (VI && 
VI != PrevNonDbgInst467
&&
!VI->isTerminator()91
) {
7141
91
        // If VI is a phi in a block with an EHPad terminator, we can't insert
7142
91
        // after it.
7143
91
        if (isa<PHINode>(VI) && 
VI->getParent()->getTerminator()->isEHPad()16
)
7144
1
          continue;
7145
90
        LLVM_DEBUG(dbgs() << "Moving Debug Value before :\n"
7146
90
                          << *DVI << ' ' << *VI);
7147
90
        DVI->removeFromParent();
7148
90
        if (isa<PHINode>(VI))
7149
15
          DVI->insertBefore(&*VI->getParent()->getFirstInsertionPt());
7150
75
        else
7151
75
          DVI->insertAfter(VI);
7152
90
        MadeChange = true;
7153
90
        ++NumDbgValueMoved;
7154
90
      }
7155
4.92k
    }
7156
2.55M
  }
7157
490k
  return MadeChange;
7158
490k
}
7159
7160
/// Scale down both weights to fit into uint32_t.
7161
4
static void scaleWeights(uint64_t &NewTrue, uint64_t &NewFalse) {
7162
4
  uint64_t NewMax = (NewTrue > NewFalse) ? 
NewTrue2
:
NewFalse2
;
7163
4
  uint32_t Scale = (NewMax / std::numeric_limits<uint32_t>::max()) + 1;
7164
4
  NewTrue = NewTrue / Scale;
7165
4
  NewFalse = NewFalse / Scale;
7166
4
}
7167
7168
/// Some targets prefer to split a conditional branch like:
7169
/// \code
7170
///   %0 = icmp ne i32 %a, 0
7171
///   %1 = icmp ne i32 %b, 0
7172
///   %or.cond = or i1 %0, %1
7173
///   br i1 %or.cond, label %TrueBB, label %FalseBB
7174
/// \endcode
7175
/// into multiple branch instructions like:
7176
/// \code
7177
///   bb1:
7178
///     %0 = icmp ne i32 %a, 0
7179
///     br i1 %0, label %TrueBB, label %bb2
7180
///   bb2:
7181
///     %1 = icmp ne i32 %b, 0
7182
///     br i1 %1, label %TrueBB, label %FalseBB
7183
/// \endcode
7184
/// This usually allows instruction selection to do even further optimizations
7185
/// and combine the compare with the branch instruction. Currently this is
7186
/// applied for targets which have "cheap" jump instructions.
7187
///
7188
/// FIXME: Remove the (equivalent?) implementation in SelectionDAG.
7189
///
7190
490k
bool CodeGenPrepare::splitBranchCondition(Function &F, bool &ModifiedDT) {
7191
490k
  if (!TM || 
!TM->Options.EnableFastISel490k
||
!TLI8.24k
||
TLI->isJumpExpensive()8.24k
)
7192
482k
    return false;
7193
8.22k
7194
8.22k
  bool MadeChange = false;
7195
8.64k
  for (auto &BB : F) {
7196
8.64k
    // Does this BB end with the following?
7197
8.64k
    //   %cond1 = icmp|fcmp|binary instruction ...
7198
8.64k
    //   %cond2 = icmp|fcmp|binary instruction ...
7199
8.64k
    //   %cond.or = or|and i1 %cond1, cond2
7200
8.64k
    //   br i1 %cond.or label %dest1, label %dest2"
7201
8.64k
    BinaryOperator *LogicOp;
7202
8.64k
    BasicBlock *TBB, *FBB;
7203
8.64k
    if (!match(BB.getTerminator(), m_Br(m_OneUse(m_BinOp(LogicOp)), TBB, FBB)))
7204
8.63k
      continue;
7205
6
7206
6
    auto *Br1 = cast<BranchInst>(BB.getTerminator());
7207
6
    if (Br1->getMetadata(LLVMContext::MD_unpredictable))
7208
2
      continue;
7209
4
7210
4
    unsigned Opc;
7211
4
    Value *Cond1, *Cond2;
7212
4
    if (match(LogicOp, m_And(m_OneUse(m_Value(Cond1)),
7213
4
                             m_OneUse(m_Value(Cond2)))))
7214
2
      Opc = Instruction::And;
7215
2
    else if (match(LogicOp, m_Or(m_OneUse(m_Value(Cond1)),
7216
2
                                 m_OneUse(m_Value(Cond2)))))
7217
1
      Opc = Instruction::Or;
7218
1
    else
7219
1
      continue;
7220
3
7221
3
    if (!match(Cond1, m_CombineOr(m_Cmp(), m_BinOp())) ||
7222
3
        !match(Cond2, m_CombineOr(m_Cmp(), m_BinOp()))   )
7223
0
      continue;
7224
3
7225
3
    LLVM_DEBUG(dbgs() << "Before branch condition splitting\n"; BB.dump());
7226
3
7227
3
    // Create a new BB.
7228
3
    auto TmpBB =
7229
3
        BasicBlock::Create(BB.getContext(), BB.getName() + ".cond.split",
7230
3
                           BB.getParent(), BB.getNextNode());
7231
3
7232
3
    // Update original basic block by using the first condition directly by the
7233
3
    // branch instruction and removing the no longer needed and/or instruction.
7234
3
    Br1->setCondition(Cond1);
7235
3
    LogicOp->eraseFromParent();
7236
3
7237
3
    // Depending on the condition we have to either replace the true or the
7238
3
    // false successor of the original branch instruction.
7239
3
    if (Opc == Instruction::And)
7240
2
      Br1->setSuccessor(0, TmpBB);
7241
1
    else
7242
1
      Br1->setSuccessor(1, TmpBB);
7243
3
7244
3
    // Fill in the new basic block.
7245
3
    auto *Br2 = IRBuilder<>(TmpBB).CreateCondBr(Cond2, TBB, FBB);
7246
3
    if (auto *I = dyn_cast<Instruction>(Cond2)) {
7247
3
      I->removeFromParent();
7248
3
      I->insertBefore(Br2);
7249
3
    }
7250
3
7251
3
    // Update PHI nodes in both successors. The original BB needs to be
7252
3
    // replaced in one successor's PHI nodes, because the branch comes now from
7253
3
    // the newly generated BB (NewBB). In the other successor we need to add one
7254
3
    // incoming edge to the PHI nodes, because both branch instructions target
7255
3
    // now the same successor. Depending on the original branch condition
7256
3
    // (and/or) we have to swap the successors (TrueDest, FalseDest), so that
7257
3
    // we perform the correct update for the PHI nodes.
7258
3
    // This doesn't change the successor order of the just created branch
7259
3
    // instruction (or any other instruction).
7260
3
    if (Opc == Instruction::Or)
7261
1
      std::swap(TBB, FBB);
7262
3
7263
3
    // Replace the old BB with the new BB.
7264
3
    TBB->replacePhiUsesWith(&BB, TmpBB);
7265
3
7266
3
    // Add another incoming edge form the new BB.
7267
3
    for (PHINode &PN : FBB->phis()) {
7268
0
      auto *Val = PN.getIncomingValueForBlock(&BB);
7269
0
      PN.addIncoming(Val, TmpBB);
7270
0
    }
7271
3
7272
3
    // Update the branch weights (from SelectionDAGBuilder::
7273
3
    // FindMergedConditions).
7274
3
    if (Opc == Instruction::Or) {
7275
1
      // Codegen X | Y as:
7276
1
      // BB1:
7277
1
      //   jmp_if_X TBB
7278
1
      //   jmp TmpBB
7279
1
      // TmpBB:
7280
1
      //   jmp_if_Y TBB
7281
1
      //   jmp FBB
7282
1
      //
7283
1
7284
1
      // We have flexibility in setting Prob for BB1 and Prob for NewBB.
7285
1
      // The requirement is that
7286
1
      //   TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB)
7287
1
      //     = TrueProb for original BB.
7288
1
      // Assuming the original weights are A and B, one choice is to set BB1's
7289
1
      // weights to A and A+2B, and set TmpBB's weights to A and 2B. This choice
7290
1
      // assumes that
7291
1
      //   TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB.
7292
1
      // Another choice is to assume TrueProb for BB1 equals to TrueProb for
7293
1
      // TmpBB, but the math is more complicated.
7294
1
      uint64_t TrueWeight, FalseWeight;
7295
1
      if (Br1->extractProfMetadata(TrueWeight, FalseWeight)) {
7296
1
        uint64_t NewTrueWeight = TrueWeight;
7297
1
        uint64_t NewFalseWeight = TrueWeight + 2 * FalseWeight;
7298
1
        scaleWeights(NewTrueWeight, NewFalseWeight);
7299
1
        Br1->setMetadata(LLVMContext::MD_prof, MDBuilder(Br1->getContext())
7300
1
                         .createBranchWeights(TrueWeight, FalseWeight));
7301
1
7302
1
        NewTrueWeight = TrueWeight;
7303
1
        NewFalseWeight = 2 * FalseWeight;
7304
1
        scaleWeights(NewTrueWeight, NewFalseWeight);
7305
1
        Br2->setMetadata(LLVMContext::MD_prof, MDBuilder(Br2->getContext())
7306
1
                         .createBranchWeights(TrueWeight, FalseWeight));
7307
1
      }
7308
2
    } else {
7309
2
      // Codegen X & Y as:
7310
2
      // BB1:
7311
2
      //   jmp_if_X TmpBB
7312
2
      //   jmp FBB
7313
2
      // TmpBB:
7314
2
      //   jmp_if_Y TBB
7315
2
      //   jmp FBB
7316
2
      //
7317
2
      //  This requires creation of TmpBB after CurBB.
7318
2
7319
2
      // We have flexibility in setting Prob for BB1 and Prob for TmpBB.
7320
2
      // The requirement is that
7321
2
      //   FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB)
7322
2
      //     = FalseProb for original BB.
7323
2
      // Assuming the original weights are A and B, one choice is to set BB1's
7324
2
      // weights to 2A+B and B, and set TmpBB's weights to 2A and B. This choice
7325
2
      // assumes that
7326
2
      //   FalseProb for BB1 == TrueProb for BB1 * FalseProb for TmpBB.
7327
2
      uint64_t TrueWeight, FalseWeight;
7328
2
      if (Br1->extractProfMetadata(TrueWeight, FalseWeight)) {
7329
1
        uint64_t NewTrueWeight = 2 * TrueWeight + FalseWeight;
7330
1
        uint64_t NewFalseWeight = FalseWeight;
7331
1
        scaleWeights(NewTrueWeight, NewFalseWeight);
7332
1
        Br1->setMetadata(LLVMContext::MD_prof, MDBuilder(Br1->getContext())
7333
1
                         .createBranchWeights(TrueWeight, FalseWeight));
7334
1
7335
1
        NewTrueWeight = 2 * TrueWeight;
7336
1
        NewFalseWeight = FalseWeight;
7337
1
        scaleWeights(NewTrueWeight, NewFalseWeight);
7338
1
        Br2->setMetadata(LLVMContext::MD_prof, MDBuilder(Br2->getContext())
7339
1
                         .createBranchWeights(TrueWeight, FalseWeight));
7340
1
      }
7341
2
    }
7342
3
7343
3
    ModifiedDT = true;
7344
3
    MadeChange = true;
7345
3
7346
3
    LLVM_DEBUG(dbgs() << "After branch condition splitting\n"; BB.dump();
7347
3
               TmpBB->dump());
7348
3
  }
7349
8.22k
  return MadeChange;
7350
8.22k
}