Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/CodeGen/SwiftErrorValueTracking.h
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//===- SwiftErrorValueTracking.h - Track swifterror VReg vals --*- C++ -*--===//
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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 implements a limited mem2reg-like analysis to promote uses of function
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// arguments and allocas marked with swiftalloc from memory into virtual
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// registers tracked by this class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFTERRORVALUETRACKING_H
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#define SWIFTERRORVALUETRACKING_H
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/CodeGen/Register.h"
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#include "llvm/IR/BasicBlock.h"
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#include "llvm/IR/DebugLoc.h"
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#include <functional>
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#include <type_traits>
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#include <utility>
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namespace llvm {
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  class Function;
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  class MachineBasicBlock;
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  class MachineFunction;
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  class MachineInstr;
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  class TargetInstrInfo;
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  class TargetLowering;
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class SwiftErrorValueTracking {
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  // Some useful objects to reduce the number of function arguments needed.
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  MachineFunction *MF;
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  const Function *Fn;
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  const TargetLowering *TLI;
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  const TargetInstrInfo *TII;
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  /// A map from swifterror value in a basic block to the virtual register it is
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  /// currently represented by.
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  DenseMap<std::pair<const MachineBasicBlock *, const Value *>, Register>
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      VRegDefMap;
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  /// A list of upward exposed vreg uses that need to be satisfied by either a
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  /// copy def or a phi node at the beginning of the basic block representing
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  /// the predecessor(s) swifterror value.
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  DenseMap<std::pair<const MachineBasicBlock *, const Value *>, Register>
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      VRegUpwardsUse;
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  /// A map from instructions that define/use a swifterror value to the virtual
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  /// register that represents that def/use.
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  llvm::DenseMap<PointerIntPair<const Instruction *, 1, bool>, Register>
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      VRegDefUses;
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  /// The swifterror argument of the current function.
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  const Value *SwiftErrorArg;
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  using SwiftErrorValues = SmallVector<const Value*, 1>;
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  /// A function can only have a single swifterror argument. And if it does
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  /// have a swifterror argument, it must be the first entry in
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  /// SwiftErrorVals.
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  SwiftErrorValues SwiftErrorVals;
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public:
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  /// Initialize data structures for specified new function.
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  void setFunction(MachineFunction &MF);
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  /// Get the (unique) function argument that was marked swifterror, or nullptr
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  /// if this function has no swifterror args.
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  const Value *getFunctionArg() const {
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    return SwiftErrorArg;
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  }
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  /// Get or create the swifterror value virtual register in
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  /// VRegDefMap for this basic block.
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  Register getOrCreateVReg(const MachineBasicBlock *, const Value *);
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  /// Set the swifterror virtual register in the VRegDefMap for this
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  /// basic block.
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  void setCurrentVReg(const MachineBasicBlock *MBB, const Value *, Register);
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  /// Get or create the swifterror value virtual register for a def of a
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  /// swifterror by an instruction.
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  Register getOrCreateVRegDefAt(const Instruction *, const MachineBasicBlock *,
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                                const Value *);
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  /// Get or create the swifterror value virtual register for a use of a
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  /// swifterror by an instruction.
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  Register getOrCreateVRegUseAt(const Instruction *, const MachineBasicBlock *,
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                                const Value *);
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  /// Create initial definitions of swifterror values in the entry block of the
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  /// current function.
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  bool createEntriesInEntryBlock(DebugLoc DbgLoc);
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  /// Propagate assigned swifterror vregs through a function, synthesizing PHI
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  /// nodes when needed to maintain consistency.
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  void propagateVRegs();
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  void preassignVRegs(MachineBasicBlock *MBB, BasicBlock::const_iterator Begin,
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                      BasicBlock::const_iterator End);
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};
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}
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#endif