1 //===- BlockFrequencyInfo.h - Block Frequency Analysis ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Loops should be simplified before this analysis.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H
15 #define LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H
17 #include "llvm/ADT/Optional.h"
18 #include "llvm/IR/PassManager.h"
19 #include "llvm/Pass.h"
20 #include "llvm/Support/BlockFrequency.h"
25 class BranchProbabilityInfo;
27 template <class BlockT> class BlockFrequencyInfoImpl;
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;
35 void operator=(const BlockFrequencyInfo &) = delete;
36 BlockFrequencyInfo(const BlockFrequencyInfo &) = delete;
40 BlockFrequencyInfo(const Function &F, const BranchProbabilityInfo &BPI,
42 BlockFrequencyInfo(BlockFrequencyInfo &&Arg);
44 BlockFrequencyInfo &operator=(BlockFrequencyInfo &&RHS);
46 ~BlockFrequencyInfo();
48 const Function *getFunction() const;
49 const BranchProbabilityInfo *getBPI() const;
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
57 BlockFrequency getBlockFreq(const BasicBlock *BB) const;
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;
64 /// \brief Returns the estimated profile count of \p Freq.
65 /// This uses the frequency \p Freq and multiplies it by
66 /// the enclosing function's count (if available) and returns the value.
67 Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const;
69 // Set the frequency of the given basic block.
70 void setBlockFreq(const BasicBlock *BB, uint64_t Freq);
72 /// calculate - compute block frequency info for the given function.
73 void calculate(const Function &F, const BranchProbabilityInfo &BPI,
76 // Print the block frequency Freq to OS using the current functions entry
77 // frequency to convert freq into a relative decimal form.
78 raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
80 // Convenience method that attempts to look up the frequency associated with
81 // BB and print it to OS.
82 raw_ostream &printBlockFreq(raw_ostream &OS, const BasicBlock *BB) const;
84 uint64_t getEntryFreq() const;
86 void print(raw_ostream &OS) const;
89 /// \brief Analysis pass which computes \c BlockFrequencyInfo.
90 class BlockFrequencyAnalysis
91 : public AnalysisInfoMixin<BlockFrequencyAnalysis> {
92 friend AnalysisInfoMixin<BlockFrequencyAnalysis>;
93 static AnalysisKey Key;
96 /// \brief Provide the result typedef for this analysis pass.
97 typedef BlockFrequencyInfo Result;
99 /// \brief Run the analysis pass over a function and produce BFI.
100 Result run(Function &F, FunctionAnalysisManager &AM);
103 /// \brief Printer pass for the \c BlockFrequencyInfo results.
104 class BlockFrequencyPrinterPass
105 : public PassInfoMixin<BlockFrequencyPrinterPass> {
109 explicit BlockFrequencyPrinterPass(raw_ostream &OS) : OS(OS) {}
110 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
113 /// \brief Legacy analysis pass which computes \c BlockFrequencyInfo.
114 class BlockFrequencyInfoWrapperPass : public FunctionPass {
115 BlockFrequencyInfo BFI;
120 BlockFrequencyInfoWrapperPass();
121 ~BlockFrequencyInfoWrapperPass() override;
123 BlockFrequencyInfo &getBFI() { return BFI; }
124 const BlockFrequencyInfo &getBFI() const { return BFI; }
126 void getAnalysisUsage(AnalysisUsage &AU) const override;
128 bool runOnFunction(Function &F) override;
129 void releaseMemory() override;
130 void print(raw_ostream &OS, const Module *M) const override;