lib/Analysis/ProfileInfoLoaderPass.cpp

   1 //===- ProfileInfoLoaderPass.cpp - LLVM Pass to load profile info ---------===//
   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 // This file implements a concrete implementation of profiling information that
  11 // loads the information from a profile dump file.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/BasicBlock.h"
  16 #include "llvm/InstrTypes.h"
  17 #include "llvm/Module.h"
  18 #include "llvm/Pass.h"
  19 #include "llvm/Analysis/Passes.h"
  20 #include "llvm/Analysis/ProfileInfo.h"
  21 #include "llvm/Analysis/ProfileInfoLoader.h"
  22 #include "llvm/Support/CommandLine.h"
  23 #include "llvm/Support/Compiler.h"
  24 #include "llvm/Support/Streams.h"
  25 using namespace llvm;
  26
  27 static cl::opt<std::string>
  28 ProfileInfoFilename("profile-info-file", cl::init("llvmprof.out"),
  29                     cl::value_desc("filename"),
  30                     cl::desc("Profile file loaded by -profile-loader"));
  31
  32 namespace {
  33   class VISIBILITY_HIDDEN LoaderPass : public ModulePass, public ProfileInfo {
  34     std::string Filename;
  35   public:
  36     static char ID; // Class identification, replacement for typeinfo
  37     explicit LoaderPass(const std::string &filename = "")
  38       : ModulePass(&ID), Filename(filename) {
  39       if (filename.empty()) Filename = ProfileInfoFilename;
  40     }
  41
  42     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  43       AU.setPreservesAll();
  44     }
  45
  46     virtual const char *getPassName() const {
  47       return "Profiling information loader";
  48     }
  49
  50     /// run - Load the profile information from the specified file.
  51     virtual bool runOnModule(Module &M);
  52   };
  53 }  // End of anonymous namespace
  54
  55 char LoaderPass::ID = 0;
  56 static RegisterPass<LoaderPass>
  57 X("profile-loader", "Load profile information from llvmprof.out", false, true);
  58
  59 static RegisterAnalysisGroup<ProfileInfo> Y(X);
  60
  61 ModulePass *llvm::createProfileLoaderPass() { return new LoaderPass(); }
  62
  63 /// createProfileLoaderPass - This function returns a Pass that loads the
  64 /// profiling information for the module from the specified filename, making it
  65 /// available to the optimizers.
  66 Pass *llvm::createProfileLoaderPass(const std::string &Filename) {
  67   return new LoaderPass(Filename);
  68 }
  69
  70 bool LoaderPass::runOnModule(Module &M) {
  71   ProfileInfoLoader PIL("profile-loader", Filename, M);
  72   EdgeCounts.clear();
  73
  74   std::vector<unsigned> ECs = PIL.getRawEdgeCounts();
  75   std::vector<unsigned> BCs = PIL.getRawBlockCounts();
  76   std::vector<unsigned> FCs = PIL.getRawFunctionCounts();
  77   // Instrument all of the edges...
  78   unsigned ei = 0;
  79   unsigned bi = 0;
  80   unsigned fi = 0;
  81   for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
  82     if (F->isDeclaration()) continue;
  83     if (fi<FCs.size()) FunctionCounts[F] = FCs[fi++];
  84     for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
  85       if (bi<BCs.size()) BlockCounts[BB] = BCs[bi++];
  86       // Okay, we have to add a counter of each outgoing edge.  If the
  87       // outgoing edge is not critical don't split it, just insert the counter
  88       // in the source or destination of the edge.
  89       TerminatorInst *TI = BB->getTerminator();
  90       for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
  91         if (ei < ECs.size())
  92           EdgeCounts[std::make_pair(BB, TI->getSuccessor(s))]+= ECs[ei++];
  93       }
  94     }
  95   }
  96
  97   if (ei != ECs.size()) {
  98     cerr << "WARNING: profile information is inconsistent with "
  99          << "the current program!\n";
 100   }
 101
 102   return false;
 103 }