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