BlockFrequencyInfo.h revision f3014761c955345d6e05491608e73228d014afb7
1//===- BlockFrequencyInfo.h - Block Frequency Analysis ----------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Loops should be simplified before this analysis. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H 15#define LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H 16 17#include "llvm/ADT/Optional.h" 18#include "llvm/IR/PassManager.h" 19#include "llvm/Pass.h" 20#include "llvm/Support/BlockFrequency.h" 21#include <cstdint> 22#include <memory> 23 24namespace llvm { 25 26class BasicBlock; 27class BranchProbabilityInfo; 28class Function; 29class LoopInfo; 30class Module; 31class raw_ostream; 32template <class BlockT> class BlockFrequencyInfoImpl; 33 34enum PGOViewCountsType { PGOVCT_None, PGOVCT_Graph, PGOVCT_Text }; 35 36/// BlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation to 37/// estimate IR basic block frequencies. 38class BlockFrequencyInfo { 39 using ImplType = BlockFrequencyInfoImpl<BasicBlock>; 40 41 std::unique_ptr<ImplType> BFI; 42 43public: 44 BlockFrequencyInfo(); 45 BlockFrequencyInfo(const Function &F, const BranchProbabilityInfo &BPI, 46 const LoopInfo &LI); 47 BlockFrequencyInfo(const BlockFrequencyInfo &) = delete; 48 BlockFrequencyInfo &operator=(const BlockFrequencyInfo &) = delete; 49 BlockFrequencyInfo(BlockFrequencyInfo &&Arg); 50 BlockFrequencyInfo &operator=(BlockFrequencyInfo &&RHS); 51 ~BlockFrequencyInfo(); 52 53 /// Handle invalidation explicitly. 54 bool invalidate(Function &F, const PreservedAnalyses &PA, 55 FunctionAnalysisManager::Invalidator &); 56 57 const Function *getFunction() const; 58 const BranchProbabilityInfo *getBPI() const; 59 void view() const; 60 61 /// getblockFreq - Return block frequency. Return 0 if we don't have the 62 /// information. Please note that initial frequency is equal to ENTRY_FREQ. It 63 /// means that we should not rely on the value itself, but only on the 64 /// comparison to the other block frequencies. We do this to avoid using of 65 /// floating points. 66 BlockFrequency getBlockFreq(const BasicBlock *BB) const; 67 68 /// \brief Returns the estimated profile count of \p BB. 69 /// This computes the relative block frequency of \p BB and multiplies it by 70 /// the enclosing function's count (if available) and returns the value. 71 Optional<uint64_t> getBlockProfileCount(const BasicBlock *BB) const; 72 73 /// \brief Returns the estimated profile count of \p Freq. 74 /// This uses the frequency \p Freq and multiplies it by 75 /// the enclosing function's count (if available) and returns the value. 76 Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const; 77 78 // Set the frequency of the given basic block. 79 void setBlockFreq(const BasicBlock *BB, uint64_t Freq); 80 81 /// Set the frequency of \p ReferenceBB to \p Freq and scale the frequencies 82 /// of the blocks in \p BlocksToScale such that their frequencies relative 83 /// to \p ReferenceBB remain unchanged. 84 void setBlockFreqAndScale(const BasicBlock *ReferenceBB, uint64_t Freq, 85 SmallPtrSetImpl<BasicBlock *> &BlocksToScale); 86 87 /// calculate - compute block frequency info for the given function. 88 void calculate(const Function &F, const BranchProbabilityInfo &BPI, 89 const LoopInfo &LI); 90 91 // Print the block frequency Freq to OS using the current functions entry 92 // frequency to convert freq into a relative decimal form. 93 raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const; 94 95 // Convenience method that attempts to look up the frequency associated with 96 // BB and print it to OS. 97 raw_ostream &printBlockFreq(raw_ostream &OS, const BasicBlock *BB) const; 98 99 uint64_t getEntryFreq() const; 100 void releaseMemory(); 101 void print(raw_ostream &OS) const; 102}; 103 104/// \brief Analysis pass which computes \c BlockFrequencyInfo. 105class BlockFrequencyAnalysis 106 : public AnalysisInfoMixin<BlockFrequencyAnalysis> { 107 friend AnalysisInfoMixin<BlockFrequencyAnalysis>; 108 109 static AnalysisKey Key; 110 111public: 112 /// \brief Provide the result type for this analysis pass. 113 using Result = BlockFrequencyInfo; 114 115 /// \brief Run the analysis pass over a function and produce BFI. 116 Result run(Function &F, FunctionAnalysisManager &AM); 117}; 118 119/// \brief Printer pass for the \c BlockFrequencyInfo results. 120class BlockFrequencyPrinterPass 121 : public PassInfoMixin<BlockFrequencyPrinterPass> { 122 raw_ostream &OS; 123 124public: 125 explicit BlockFrequencyPrinterPass(raw_ostream &OS) : OS(OS) {} 126 127 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); 128}; 129 130/// \brief Legacy analysis pass which computes \c BlockFrequencyInfo. 131class BlockFrequencyInfoWrapperPass : public FunctionPass { 132 BlockFrequencyInfo BFI; 133 134public: 135 static char ID; 136 137 BlockFrequencyInfoWrapperPass(); 138 ~BlockFrequencyInfoWrapperPass() override; 139 140 BlockFrequencyInfo &getBFI() { return BFI; } 141 const BlockFrequencyInfo &getBFI() const { return BFI; } 142 143 void getAnalysisUsage(AnalysisUsage &AU) const override; 144 145 bool runOnFunction(Function &F) override; 146 void releaseMemory() override; 147 void print(raw_ostream &OS, const Module *M) const override; 148}; 149 150} // end namespace llvm 151 152#endif // LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H 153