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 const Function *getFunction() const; 49 const BranchProbabilityInfo *getBPI() const; 50 void view() const; 51 52 /// getblockFreq - Return block frequency. Return 0 if we don't have the 53 /// information. Please note that initial frequency is equal to ENTRY_FREQ. It 54 /// means that we should not rely on the value itself, but only on the 55 /// comparison to the other block frequencies. We do this to avoid using of 56 /// floating points. 57 BlockFrequency getBlockFreq(const BasicBlock *BB) const; 58 59 /// \brief Returns the estimated profile count of \p BB. 60 /// This computes the relative block frequency of \p BB and multiplies it by 61 /// the enclosing function's count (if available) and returns the value. 62 Optional<uint64_t> getBlockProfileCount(const BasicBlock *BB) const; 63 64 // Set the frequency of the given basic block. 65 void setBlockFreq(const BasicBlock *BB, uint64_t Freq); 66 67 /// calculate - compute block frequency info for the given function. 68 void calculate(const Function &F, const BranchProbabilityInfo &BPI, 69 const LoopInfo &LI); 70 71 // Print the block frequency Freq to OS using the current functions entry 72 // frequency to convert freq into a relative decimal form. 73 raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const; 74 75 // Convenience method that attempts to look up the frequency associated with 76 // BB and print it to OS. 77 raw_ostream &printBlockFreq(raw_ostream &OS, const BasicBlock *BB) const; 78 79 uint64_t getEntryFreq() const; 80 void releaseMemory(); 81 void print(raw_ostream &OS) const; 82 }; 83 84 /// \brief Analysis pass which computes \c BlockFrequencyInfo. 85 class BlockFrequencyAnalysis 86 : public AnalysisInfoMixin<BlockFrequencyAnalysis> { 87 friend AnalysisInfoMixin<BlockFrequencyAnalysis>; 88 static char PassID; 89 90 public: 91 /// \brief Provide the result typedef for this analysis pass. 92 typedef BlockFrequencyInfo Result; 93 94 /// \brief Run the analysis pass over a function and produce BFI. 95 Result run(Function &F, AnalysisManager<Function> &AM); 96 }; 97 98 /// \brief Printer pass for the \c BlockFrequencyInfo results. 99 class BlockFrequencyPrinterPass 100 : public PassInfoMixin<BlockFrequencyPrinterPass> { 101 raw_ostream &OS; 102 103 public: BlockFrequencyPrinterPass(raw_ostream & OS)104 explicit BlockFrequencyPrinterPass(raw_ostream &OS) : OS(OS) {} 105 PreservedAnalyses run(Function &F, AnalysisManager<Function> &AM); 106 }; 107 108 /// \brief Legacy analysis pass which computes \c BlockFrequencyInfo. 109 class BlockFrequencyInfoWrapperPass : public FunctionPass { 110 BlockFrequencyInfo BFI; 111 112 public: 113 static char ID; 114 115 BlockFrequencyInfoWrapperPass(); 116 ~BlockFrequencyInfoWrapperPass() override; 117 getBFI()118 BlockFrequencyInfo &getBFI() { return BFI; } getBFI()119 const BlockFrequencyInfo &getBFI() const { return BFI; } 120 121 void getAnalysisUsage(AnalysisUsage &AU) const override; 122 123 bool runOnFunction(Function &F) override; 124 void releaseMemory() override; 125 void print(raw_ostream &OS, const Module *M) const override; 126 }; 127 128 } 129 130 #endif 131