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