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