1 //===- MachineBlockFrequencyInfo.h - MBB Frequency Analysis -----*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Loops should be simplified before this analysis. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H 14 #define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H 15 16 #include "llvm/ADT/Optional.h" 17 #include "llvm/CodeGen/MachineFunctionPass.h" 18 #include "llvm/Support/BlockFrequency.h" 19 #include <cstdint> 20 #include <memory> 21 22 namespace llvm { 23 24 template <class BlockT> class BlockFrequencyInfoImpl; 25 class MachineBasicBlock; 26 class MachineBranchProbabilityInfo; 27 class MachineFunction; 28 class MachineLoopInfo; 29 class raw_ostream; 30 31 /// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation 32 /// to estimate machine basic block frequencies. 33 class MachineBlockFrequencyInfo : public MachineFunctionPass { 34 using ImplType = BlockFrequencyInfoImpl<MachineBasicBlock>; 35 std::unique_ptr<ImplType> MBFI; 36 37 public: 38 static char ID; 39 40 MachineBlockFrequencyInfo(); 41 explicit MachineBlockFrequencyInfo(MachineFunction &F, 42 MachineBranchProbabilityInfo &MBPI, 43 MachineLoopInfo &MLI); 44 ~MachineBlockFrequencyInfo() override; 45 46 void getAnalysisUsage(AnalysisUsage &AU) const override; 47 48 bool runOnMachineFunction(MachineFunction &F) override; 49 50 /// calculate - compute block frequency info for the given function. 51 void calculate(const MachineFunction &F, 52 const MachineBranchProbabilityInfo &MBPI, 53 const MachineLoopInfo &MLI); 54 55 void releaseMemory() override; 56 57 /// getblockFreq - Return block frequency. Return 0 if we don't have the 58 /// information. Please note that initial frequency is equal to 1024. It means 59 /// that we should not rely on the value itself, but only on the comparison to 60 /// the other block frequencies. We do this to avoid using of floating points. 61 /// 62 BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const; 63 64 Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const; 65 Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const; 66 67 bool isIrrLoopHeader(const MachineBasicBlock *MBB); 68 69 const MachineFunction *getFunction() const; 70 const MachineBranchProbabilityInfo *getMBPI() const; 71 void view(const Twine &Name, bool isSimple = true) const; 72 73 // Print the block frequency Freq to OS using the current functions entry 74 // frequency to convert freq into a relative decimal form. 75 raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const; 76 77 // Convenience method that attempts to look up the frequency associated with 78 // BB and print it to OS. 79 raw_ostream &printBlockFreq(raw_ostream &OS, 80 const MachineBasicBlock *MBB) const; 81 82 uint64_t getEntryFreq() const; 83 }; 84 85 } // end namespace llvm 86 87 #endif // LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H 88