BasicBlockMatchingAndInference.h

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//===- llvm/CodeGen/BasicBlockMatchingAndInference.h ------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Infer weights for all basic blocks using matching and inference.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CODEGEN_BASIC_BLOCK_AND_INFERENCE_H
#define LLVM_CODEGEN_BASIC_BLOCK_AND_INFERENCE_H
 
#include "llvm/CodeGen/BasicBlockSectionsProfileReader.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/Transforms/Utils/SampleProfileInference.h"
 
namespace llvm {
 
/// Whether to match basic blocks using BBIDs instead of hashes for Propeller
/// inference.
LLVM_ABI extern cl::opt<bool> PropellerMatchBBID;
 
class LLVM_ABI BasicBlockMatchingAndInference : public MachineFunctionPass {
private:
  using Edge = std::pair<const MachineBasicBlock *, const MachineBasicBlock *>;
  using BlockWeightMap = DenseMap<const MachineBasicBlock *, uint64_t>;
  using EdgeWeightMap = DenseMap<Edge, uint64_t>;
  using BlockEdgeMap = DenseMap<const MachineBasicBlock *,
                                SmallVector<const MachineBasicBlock *, 8>>;
 
  struct WeightInfo {
    // Weight of basic blocks.
    BlockWeightMap BlockWeights;
    // Weight of edges.
    EdgeWeightMap EdgeWeights;
  };
 
public:
  static char ID;
  BasicBlockMatchingAndInference();
 
  StringRef getPassName() const override {
    return "Basic Block Matching and Inference";
  }
 
  void getAnalysisUsage(AnalysisUsage &AU) const override;
 
  bool runOnMachineFunction(MachineFunction &F) override;
 
  std::optional<WeightInfo> getWeightInfo(StringRef FuncName) const;
 
private:
  StringMap<WeightInfo> ProgramWeightInfo;
 
  WeightInfo initWeightInfoByMatching(MachineFunction &MF);
  WeightInfo initWeightInfoByBBID(MachineFunction &MF, const CFGProfile &CFG);
 
  void generateWeightInfoByInference(MachineFunction &MF,
                                     WeightInfo &MatchWeight);
};
 
} // end namespace llvm
 
#endif // LLVM_CODEGEN_BASIC_BLOCK_AND_INFERENCE_H