1//===- MachineBlockFrequencyInfo.h - MBB Frequency Analysis -----*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// Loops should be simplified before this analysis. 10// 11//===----------------------------------------------------------------------===// 12 13#ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H 14#define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H 15 16#include "llvm/ADT/Optional.h" 17#include "llvm/CodeGen/MachineFunctionPass.h" 18#include "llvm/Support/BlockFrequency.h" 19#include <cstdint> 20#include <memory> 21 22namespace llvm { 23 24template <class BlockT> class BlockFrequencyInfoImpl; 25class MachineBasicBlock; 26class MachineBranchProbabilityInfo; 27class MachineFunction; 28class MachineLoopInfo; 29class raw_ostream; 30 31/// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation 32/// to estimate machine basic block frequencies. 33class MachineBlockFrequencyInfo : public MachineFunctionPass { 34 using ImplType = BlockFrequencyInfoImpl<MachineBasicBlock>; 35 std::unique_ptr<ImplType> MBFI; 36 37public: 38 static char ID; 39 40 MachineBlockFrequencyInfo(); 41 explicit MachineBlockFrequencyInfo(MachineFunction &F, 42 MachineBranchProbabilityInfo &MBPI, 43 MachineLoopInfo &MLI); 44 ~MachineBlockFrequencyInfo() override; 45 46 void getAnalysisUsage(AnalysisUsage &AU) const override; 47 48 bool runOnMachineFunction(MachineFunction &F) override; 49 50 /// calculate - compute block frequency info for the given function. 51 void calculate(const MachineFunction &F, 52 const MachineBranchProbabilityInfo &MBPI, 53 const MachineLoopInfo &MLI); 54 55 void releaseMemory() override; 56 57 /// getblockFreq - Return block frequency. Return 0 if we don't have the 58 /// information. Please note that initial frequency is equal to 1024. It means 59 /// that we should not rely on the value itself, but only on the comparison to 60 /// the other block frequencies. We do this to avoid using of floating points. 61 /// 62 BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const; 63 64 Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const; 65 Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const; 66 67 bool isIrrLoopHeader(const MachineBasicBlock *MBB); 68 69 const MachineFunction *getFunction() const; 70 const MachineBranchProbabilityInfo *getMBPI() const; 71 void view(const Twine &Name, bool isSimple = true) const; 72 73 // Print the block frequency Freq to OS using the current functions entry 74 // frequency to convert freq into a relative decimal form. 75 raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const; 76 77 // Convenience method that attempts to look up the frequency associated with 78 // BB and print it to OS. 79 raw_ostream &printBlockFreq(raw_ostream &OS, 80 const MachineBasicBlock *MBB) const; 81 82 uint64_t getEntryFreq() const; 83}; 84 85} // end namespace llvm 86 87#endif // LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H 88