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