//===- MachineBlockFrequencyInfo.cpp - MBB Frequency Analysis -------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // Loops should be simplified before this analysis. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineBlockFrequencyInfo.h" #include "llvm/Analysis/BlockFrequencyInfoImpl.h" #include "llvm/CodeGen/MachineBranchProbabilityInfo.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/Passes.h" #include "llvm/InitializePasses.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/GraphWriter.h" using namespace llvm; #define DEBUG_TYPE "block-freq" #ifndef NDEBUG enum GVDAGType { GVDT_None, GVDT_Fraction, GVDT_Integer }; static cl::opt<GVDAGType> ViewMachineBlockFreqPropagationDAG("view-machine-block-freq-propagation-dags", cl::Hidden, cl::desc("Pop up a window to show a dag displaying how machine block " "frequencies propagate through the CFG."), cl::values( clEnumValN(GVDT_None, "none", "do not display graphs."), clEnumValN(GVDT_Fraction, "fraction", "display a graph using the " "fractional block frequency representation."), clEnumValN(GVDT_Integer, "integer", "display a graph using the raw " "integer fractional block frequency representation."), clEnumValEnd)); namespace llvm { template <> struct GraphTraits<MachineBlockFrequencyInfo *> { typedef const MachineBasicBlock NodeType; typedef MachineBasicBlock::const_succ_iterator ChildIteratorType; typedef MachineFunction::const_iterator nodes_iterator; static inline const NodeType *getEntryNode(const MachineBlockFrequencyInfo *G) { return G->getFunction()->begin(); } static ChildIteratorType child_begin(const NodeType *N) { return N->succ_begin(); } static ChildIteratorType child_end(const NodeType *N) { return N->succ_end(); } static nodes_iterator nodes_begin(const MachineBlockFrequencyInfo *G) { return G->getFunction()->begin(); } static nodes_iterator nodes_end(const MachineBlockFrequencyInfo *G) { return G->getFunction()->end(); } }; template<> struct DOTGraphTraits<MachineBlockFrequencyInfo*> : public DefaultDOTGraphTraits { explicit DOTGraphTraits(bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} static std::string getGraphName(const MachineBlockFrequencyInfo *G) { return G->getFunction()->getName(); } std::string getNodeLabel(const MachineBasicBlock *Node, const MachineBlockFrequencyInfo *Graph) { std::string Result; raw_string_ostream OS(Result); OS << Node->getName().str() << ":"; switch (ViewMachineBlockFreqPropagationDAG) { case GVDT_Fraction: Graph->printBlockFreq(OS, Node); break; case GVDT_Integer: OS << Graph->getBlockFreq(Node).getFrequency(); break; case GVDT_None: llvm_unreachable("If we are not supposed to render a graph we should " "never reach this point."); } return Result; } }; } // end namespace llvm #endif INITIALIZE_PASS_BEGIN(MachineBlockFrequencyInfo, "machine-block-freq", "Machine Block Frequency Analysis", true, true) INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo) INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo) INITIALIZE_PASS_END(MachineBlockFrequencyInfo, "machine-block-freq", "Machine Block Frequency Analysis", true, true) char MachineBlockFrequencyInfo::ID = 0; MachineBlockFrequencyInfo:: MachineBlockFrequencyInfo() :MachineFunctionPass(ID) { initializeMachineBlockFrequencyInfoPass(*PassRegistry::getPassRegistry()); } MachineBlockFrequencyInfo::~MachineBlockFrequencyInfo() {} void MachineBlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequired<MachineBranchProbabilityInfo>(); AU.addRequired<MachineLoopInfo>(); AU.setPreservesAll(); MachineFunctionPass::getAnalysisUsage(AU); } bool MachineBlockFrequencyInfo::runOnMachineFunction(MachineFunction &F) { MachineBranchProbabilityInfo &MBPI = getAnalysis<MachineBranchProbabilityInfo>(); MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>(); if (!MBFI) MBFI.reset(new ImplType); MBFI->doFunction(&F, &MBPI, &MLI); #ifndef NDEBUG if (ViewMachineBlockFreqPropagationDAG != GVDT_None) { view(); } #endif return false; } void MachineBlockFrequencyInfo::releaseMemory() { MBFI.reset(); } /// Pop up a ghostview window with the current block frequency propagation /// rendered using dot. void MachineBlockFrequencyInfo::view() const { // This code is only for debugging. #ifndef NDEBUG ViewGraph(const_cast<MachineBlockFrequencyInfo *>(this), "MachineBlockFrequencyDAGs"); #else errs() << "MachineBlockFrequencyInfo::view is only available in debug builds " "on systems with Graphviz or gv!\n"; #endif // NDEBUG } BlockFrequency MachineBlockFrequencyInfo:: getBlockFreq(const MachineBasicBlock *MBB) const { return MBFI ? MBFI->getBlockFreq(MBB) : 0; } const MachineFunction *MachineBlockFrequencyInfo::getFunction() const { return MBFI ? MBFI->getFunction() : nullptr; } raw_ostream & MachineBlockFrequencyInfo::printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const { return MBFI ? MBFI->printBlockFreq(OS, Freq) : OS; } raw_ostream & MachineBlockFrequencyInfo::printBlockFreq(raw_ostream &OS, const MachineBasicBlock *MBB) const { return MBFI ? MBFI->printBlockFreq(OS, MBB) : OS; } uint64_t MachineBlockFrequencyInfo::getEntryFreq() const { return MBFI ? MBFI->getEntryFreq() : 0; }