1 //====----- MachineBlockFrequency.cpp - Machine Block Frequency Analysis ----====// 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 #include "llvm/InitializePasses.h" 15 #include "llvm/Analysis/BlockFrequencyImpl.h" 16 #include "llvm/CodeGen/MachineBlockFrequency.h" 17 #include "llvm/CodeGen/Passes.h" 18 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h" 19 20 using namespace llvm; 21 22 INITIALIZE_PASS_BEGIN(MachineBlockFrequency, "machine-block-freq", 23 "Machine Block Frequency Analysis", true, true) 24 INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo) 25 INITIALIZE_PASS_END(MachineBlockFrequency, "machine-block-freq", 26 "Machine Block Frequency Analysis", true, true) 27 28 char MachineBlockFrequency::ID = 0; 29 30 31 MachineBlockFrequency::MachineBlockFrequency() : MachineFunctionPass(ID) { 32 initializeMachineBlockFrequencyPass(*PassRegistry::getPassRegistry()); 33 MBFI = new BlockFrequencyImpl<MachineBasicBlock, MachineFunction, 34 MachineBranchProbabilityInfo>(); 35 } 36 37 MachineBlockFrequency::~MachineBlockFrequency() { 38 delete MBFI; 39 } 40 41 void MachineBlockFrequency::getAnalysisUsage(AnalysisUsage &AU) const { 42 AU.addRequired<MachineBranchProbabilityInfo>(); 43 AU.setPreservesAll(); 44 } 45 46 bool MachineBlockFrequency::runOnMachineFunction(MachineFunction &F) { 47 MachineBranchProbabilityInfo &MBPI = getAnalysis<MachineBranchProbabilityInfo>(); 48 MBFI->doFunction(&F, &MBPI); 49 return false; 50 } 51 52 /// getblockFreq - Return block frequency. Never return 0, value must be 53 /// positive. Please note that initial frequency is equal to 1024. It means that 54 /// we should not rely on the value itself, but only on the comparison to the 55 /// other block frequencies. We do this to avoid using of floating points. 56 /// 57 uint32_t MachineBlockFrequency::getBlockFreq(MachineBasicBlock *MBB) { 58 return MBFI->getBlockFreq(MBB); 59 } 60
