Coverage Report

Created: 2018-07-19 03:59

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/Analysis/InstructionSimplify.h
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//===-- InstructionSimplify.h - Fold instrs into simpler forms --*- C++ -*-===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file declares routines for folding instructions into simpler forms
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// that do not require creating new instructions.  This does constant folding
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// ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
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// returning a constant ("and i32 %x, 0" -> "0") or an already existing value
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// ("and i32 %x, %x" -> "%x").  If the simplification is also an instruction
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// then it dominates the original instruction.
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//
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// These routines implicitly resolve undef uses. The easiest way to be safe when
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// using these routines to obtain simplified values for existing instructions is
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// to always replace all uses of the instructions with the resulting simplified
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// values. This will prevent other code from seeing the same undef uses and
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// resolving them to different values.
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//
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// These routines are designed to tolerate moderately incomplete IR, such as
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// instructions that are not connected to basic blocks yet. However, they do
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// require that all the IR that they encounter be valid. In particular, they
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// require that all non-constant values be defined in the same function, and the
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// same call context of that function (and not split between caller and callee
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// contexts of a directly recursive call, for example).
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
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#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
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#include "llvm/IR/User.h"
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namespace llvm {
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class Function;
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template <typename T, typename... TArgs> class AnalysisManager;
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template <class T> class ArrayRef;
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class AssumptionCache;
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class DominatorTree;
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class Instruction;
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class ImmutableCallSite;
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class DataLayout;
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class FastMathFlags;
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struct LoopStandardAnalysisResults;
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class OptimizationRemarkEmitter;
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class Pass;
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class TargetLibraryInfo;
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class Type;
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class Value;
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struct SimplifyQuery {
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  const DataLayout &DL;
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  const TargetLibraryInfo *TLI = nullptr;
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  const DominatorTree *DT = nullptr;
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  AssumptionCache *AC = nullptr;
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  const Instruction *CxtI = nullptr;
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  SimplifyQuery(const DataLayout &DL, const Instruction *CXTI = nullptr)
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      : DL(DL), CxtI(CXTI) {}
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  SimplifyQuery(const DataLayout &DL, const TargetLibraryInfo *TLI,
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                const DominatorTree *DT = nullptr,
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                AssumptionCache *AC = nullptr,
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                const Instruction *CXTI = nullptr)
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      : DL(DL), TLI(TLI), DT(DT), AC(AC), CxtI(CXTI) {}
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  SimplifyQuery getWithInstruction(Instruction *I) const {
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    SimplifyQuery Copy(*this);
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    Copy.CxtI = I;
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    return Copy;
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  }
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};
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// NOTE: the explicit multiple argument versions of these functions are
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// deprecated.
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// Please use the SimplifyQuery versions in new code.
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/// Given operands for an Add, fold the result or return null.
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Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
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                       const SimplifyQuery &Q);
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/// Given operands for a Sub, fold the result or return null.
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Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
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                       const SimplifyQuery &Q);
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/// Given operands for an FAdd, fold the result or return null.
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Value *SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF,
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                        const SimplifyQuery &Q);
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/// Given operands for an FSub, fold the result or return null.
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Value *SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF,
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                        const SimplifyQuery &Q);
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/// Given operands for an FMul, fold the result or return null.
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Value *SimplifyFMulInst(Value *LHS, Value *RHS, FastMathFlags FMF,
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                        const SimplifyQuery &Q);
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/// Given operands for a Mul, fold the result or return null.
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Value *SimplifyMulInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for an SDiv, fold the result or return null.
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Value *SimplifySDivInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for a UDiv, fold the result or return null.
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Value *SimplifyUDivInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for an FDiv, fold the result or return null.
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Value *SimplifyFDivInst(Value *LHS, Value *RHS, FastMathFlags FMF,
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                        const SimplifyQuery &Q);
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/// Given operands for an SRem, fold the result or return null.
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Value *SimplifySRemInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for a URem, fold the result or return null.
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Value *SimplifyURemInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for an FRem, fold the result or return null.
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Value *SimplifyFRemInst(Value *LHS, Value *RHS, FastMathFlags FMF,
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                        const SimplifyQuery &Q);
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/// Given operands for a Shl, fold the result or return null.
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Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
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                       const SimplifyQuery &Q);
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/// Given operands for a LShr, fold the result or return null.
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Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
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                        const SimplifyQuery &Q);
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/// Given operands for a AShr, fold the result or return nulll.
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Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
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                        const SimplifyQuery &Q);
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/// Given operands for an And, fold the result or return null.
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Value *SimplifyAndInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for an Or, fold the result or return null.
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Value *SimplifyOrInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for an Xor, fold the result or return null.
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Value *SimplifyXorInst(Value *LHS, Value *RHS, const SimplifyQuery &Q);
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/// Given operands for an ICmpInst, fold the result or return null.
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Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
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                        const SimplifyQuery &Q);
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/// Given operands for an FCmpInst, fold the result or return null.
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Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
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                        FastMathFlags FMF, const SimplifyQuery &Q);
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/// Given operands for a SelectInst, fold the result or return null.
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Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
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                          const SimplifyQuery &Q);
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/// Given operands for a GetElementPtrInst, fold the result or return null.
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Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
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                       const SimplifyQuery &Q);
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/// Given operands for an InsertValueInst, fold the result or return null.
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Value *SimplifyInsertValueInst(Value *Agg, Value *Val, ArrayRef<unsigned> Idxs,
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                               const SimplifyQuery &Q);
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/// Given operands for an InsertElement, fold the result or return null.
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Value *SimplifyInsertElementInst(Value *Vec, Value *Elt, Value *Idx,
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                                 const SimplifyQuery &Q);
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/// Given operands for an ExtractValueInst, fold the result or return null.
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Value *SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
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                                const SimplifyQuery &Q);
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/// Given operands for an ExtractElementInst, fold the result or return null.
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Value *SimplifyExtractElementInst(Value *Vec, Value *Idx,
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                                  const SimplifyQuery &Q);
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/// Given operands for a CastInst, fold the result or return null.
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Value *SimplifyCastInst(unsigned CastOpc, Value *Op, Type *Ty,
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                        const SimplifyQuery &Q);
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/// Given operands for a ShuffleVectorInst, fold the result or return null.
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Value *SimplifyShuffleVectorInst(Value *Op0, Value *Op1, Constant *Mask,
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                                 Type *RetTy, const SimplifyQuery &Q);
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//=== Helper functions for higher up the class hierarchy.
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/// Given operands for a CmpInst, fold the result or return null.
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Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
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                       const SimplifyQuery &Q);
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/// Given operands for a BinaryOperator, fold the result or return null.
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Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
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                     const SimplifyQuery &Q);
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/// Given operands for an FP BinaryOperator, fold the result or return null.
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/// In contrast to SimplifyBinOp, try to use FastMathFlag when folding the
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/// result. In case we don't need FastMathFlags, simply fall to SimplifyBinOp.
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Value *SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
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                       FastMathFlags FMF, const SimplifyQuery &Q);
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/// Given a callsite, fold the result or return null.
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Value *SimplifyCall(ImmutableCallSite CS, const SimplifyQuery &Q);
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/// Given a function and iterators over arguments, fold the result or return
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/// null.
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Value *SimplifyCall(ImmutableCallSite CS, Value *V, User::op_iterator ArgBegin,
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                    User::op_iterator ArgEnd, const SimplifyQuery &Q);
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/// Given a function and set of arguments, fold the result or return null.
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Value *SimplifyCall(ImmutableCallSite CS, Value *V, ArrayRef<Value *> Args,
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                    const SimplifyQuery &Q);
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/// See if we can compute a simplified version of this instruction. If not,
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/// return null.
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Value *SimplifyInstruction(Instruction *I, const SimplifyQuery &Q,
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                           OptimizationRemarkEmitter *ORE = nullptr);
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/// Replace all uses of 'I' with 'SimpleV' and simplify the uses recursively.
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///
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/// This first performs a normal RAUW of I with SimpleV. It then recursively
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/// attempts to simplify those users updated by the operation. The 'I'
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/// instruction must not be equal to the simplified value 'SimpleV'.
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///
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/// The function returns true if any simplifications were performed.
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bool replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
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                                   const TargetLibraryInfo *TLI = nullptr,
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                                   const DominatorTree *DT = nullptr,
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                                   AssumptionCache *AC = nullptr);
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/// Recursively attempt to simplify an instruction.
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///
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/// This routine uses SimplifyInstruction to simplify 'I', and if successful
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/// replaces uses of 'I' with the simplified value. It then recurses on each
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/// of the users impacted. It returns true if any simplifications were
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/// performed.
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bool recursivelySimplifyInstruction(Instruction *I,
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                                    const TargetLibraryInfo *TLI = nullptr,
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                                    const DominatorTree *DT = nullptr,
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                                    AssumptionCache *AC = nullptr);
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// These helper functions return a SimplifyQuery structure that contains as
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// many of the optional analysis we use as are currently valid.  This is the
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// strongly preferred way of constructing SimplifyQuery in passes.
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const SimplifyQuery getBestSimplifyQuery(Pass &, Function &);
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template <class T, class... TArgs>
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const SimplifyQuery getBestSimplifyQuery(AnalysisManager<T, TArgs...> &,
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                                         Function &);
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const SimplifyQuery getBestSimplifyQuery(LoopStandardAnalysisResults &,
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                                         const DataLayout &);
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} // end namespace llvm
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#endif
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