tools/llvm-prof/llvm-prof.cpp

   1 //===- llvm-prof.cpp - Read in and process llvmprof.out data files --------===//
   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 tools is meant for use with the various LLVM profiling instrumentation
  11 // passes.  It reads in the data file produced by executing an instrumented
  12 // program, and outputs a nice report.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/InstrTypes.h"
  17 #include "llvm/LLVMContext.h"
  18 #include "llvm/Module.h"
  19 #include "llvm/PassManager.h"
  20 #include "llvm/Assembly/AssemblyAnnotationWriter.h"
  21 #include "llvm/Analysis/ProfileInfo.h"
  22 #include "llvm/Analysis/ProfileInfoLoader.h"
  23 #include "llvm/Analysis/Passes.h"
  24 #include "llvm/Bitcode/ReaderWriter.h"
  25 #include "llvm/Support/CommandLine.h"
  26 #include "llvm/Support/FormattedStream.h"
  27 #include "llvm/Support/ManagedStatic.h"
  28 #include "llvm/Support/MemoryBuffer.h"
  29 #include "llvm/Support/PrettyStackTrace.h"
  30 #include "llvm/Support/raw_ostream.h"
  31 #include "llvm/Support/Format.h"
  32 #include "llvm/Support/Signals.h"
  33 #include "llvm/Support/system_error.h"
  34 #include <algorithm>
  35 #include <iomanip>
  36 #include <map>
  37 #include <set>
  38
  39 using namespace llvm;
  40
  41 namespace {
  42   cl::opt<std::string>
  43   BitcodeFile(cl::Positional, cl::desc("<program bitcode file>"),
  44               cl::Required);
  45
  46   cl::opt<std::string>
  47   ProfileDataFile(cl::Positional, cl::desc("<llvmprof.out file>"),
  48                   cl::Optional, cl::init("llvmprof.out"));
  49
  50   cl::opt<bool>
  51   PrintAnnotatedLLVM("annotated-llvm",
  52                      cl::desc("Print LLVM code with frequency annotations"));
  53   cl::alias PrintAnnotated2("A", cl::desc("Alias for --annotated-llvm"),
  54                             cl::aliasopt(PrintAnnotatedLLVM));
  55   cl::opt<bool>
  56   PrintAllCode("print-all-code",
  57                cl::desc("Print annotated code for the entire program"));
  58 }
  59
  60 // PairSecondSort - A sorting predicate to sort by the second element of a pair.
  61 template<class T>
  62 struct PairSecondSortReverse
  63   : public std::binary_function<std::pair<T, double>,
  64                                 std::pair<T, double>, bool> {
  65   bool operator()(const std::pair<T, double> &LHS,
  66                   const std::pair<T, double> &RHS) const {
  67     return LHS.second > RHS.second;
  68   }
  69 };
  70
  71 static double ignoreMissing(double w) {
  72   if (w == ProfileInfo::MissingValue) return 0;
  73   return w;
  74 }
  75
  76 namespace {
  77   class ProfileAnnotator : public AssemblyAnnotationWriter {
  78     ProfileInfo &PI;
  79   public:
  80     ProfileAnnotator(ProfileInfo &pi) : PI(pi) {}
  81
  82     virtual void emitFunctionAnnot(const Function *F,
  83                                    formatted_raw_ostream &OS) {
  84       double w = PI.getExecutionCount(F);
  85       if (w != ProfileInfo::MissingValue) {
  86         OS << ";;; %" << F->getName() << " called "<<(unsigned)w
  87            <<" times.\n;;;\n";
  88       }
  89     }
  90     virtual void emitBasicBlockStartAnnot(const BasicBlock *BB,
  91                                           formatted_raw_ostream &OS) {
  92       double w = PI.getExecutionCount(BB);
  93       if (w != ProfileInfo::MissingValue) {
  94         if (w != 0) {
  95           OS << "\t;;; Basic block executed " << (unsigned)w << " times.\n";
  96         } else {
  97           OS << "\t;;; Never executed!\n";
  98         }
  99       }
 100     }
 101
 102     virtual void emitBasicBlockEndAnnot(const BasicBlock *BB,
 103                                         formatted_raw_ostream &OS) {
 104       // Figure out how many times each successor executed.
 105       std::vector<std::pair<ProfileInfo::Edge, double> > SuccCounts;
 106
 107       const TerminatorInst *TI = BB->getTerminator();
 108       for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
 109         BasicBlock* Succ = TI->getSuccessor(s);
 110         double w = ignoreMissing(PI.getEdgeWeight(std::make_pair(BB, Succ)));
 111         if (w != 0)
 112           SuccCounts.push_back(std::make_pair(std::make_pair(BB, Succ), w));
 113       }
 114       if (!SuccCounts.empty()) {
 115         OS << "\t;;; Out-edge counts:";
 116         for (unsigned i = 0, e = SuccCounts.size(); i != e; ++i)
 117           OS << " [" << (SuccCounts[i]).second << " -> "
 118              << (SuccCounts[i]).first.second->getName() << "]";
 119         OS << "\n";
 120       }
 121     }
 122   };
 123 }
 124
 125 namespace {
 126   /// ProfileInfoPrinterPass - Helper pass to dump the profile information for
 127   /// a module.
 128   //
 129   // FIXME: This should move elsewhere.
 130   class ProfileInfoPrinterPass : public ModulePass {
 131     ProfileInfoLoader &PIL;
 132   public:
 133     static char ID; // Class identification, replacement for typeinfo.
 134     explicit ProfileInfoPrinterPass(ProfileInfoLoader &_PIL)
 135       : ModulePass(ID), PIL(_PIL) {}
 136
 137     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 138       AU.setPreservesAll();
 139       AU.addRequired<ProfileInfo>();
 140     }
 141
 142     bool runOnModule(Module &M);
 143   };
 144 }
 145
 146 char ProfileInfoPrinterPass::ID = 0;
 147
 148 bool ProfileInfoPrinterPass::runOnModule(Module &M) {
 149   ProfileInfo &PI = getAnalysis<ProfileInfo>();
 150   std::map<const Function  *, unsigned> FuncFreqs;
 151   std::map<const BasicBlock*, unsigned> BlockFreqs;
 152   std::map<ProfileInfo::Edge, unsigned> EdgeFreqs;
 153
 154   // Output a report. Eventually, there will be multiple reports selectable on
 155   // the command line, for now, just keep things simple.
 156
 157   // Emit the most frequent function table...
 158   std::vector<std::pair<Function*, double> > FunctionCounts;
 159   std::vector<std::pair<BasicBlock*, double> > Counts;
 160   for (Module::iterator FI = M.begin(), FE = M.end(); FI != FE; ++FI) {
 161     if (FI->isDeclaration()) continue;
 162     double w = ignoreMissing(PI.getExecutionCount(FI));
 163     FunctionCounts.push_back(std::make_pair(FI, w));
 164     for (Function::iterator BB = FI->begin(), BBE = FI->end();
 165          BB != BBE; ++BB) {
 166       double w = ignoreMissing(PI.getExecutionCount(BB));
 167       Counts.push_back(std::make_pair(BB, w));
 168     }
 169   }
 170
 171   // Sort by the frequency, backwards.
 172   sort(FunctionCounts.begin(), FunctionCounts.end(),
 173             PairSecondSortReverse<Function*>());
 174
 175   double TotalExecutions = 0;
 176   for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i)
 177     TotalExecutions += FunctionCounts[i].second;
 178
 179   outs() << "===" << std::string(73, '-') << "===\n"
 180          << "LLVM profiling output for execution";
 181   if (PIL.getNumExecutions() != 1) outs() << "s";
 182   outs() << ":\n";
 183
 184   for (unsigned i = 0, e = PIL.getNumExecutions(); i != e; ++i) {
 185     outs() << "  ";
 186     if (e != 1) outs() << i+1 << ". ";
 187     outs() << PIL.getExecution(i) << "\n";
 188   }
 189
 190   outs() << "\n===" << std::string(73, '-') << "===\n";
 191   outs() << "Function execution frequencies:\n\n";
 192
 193   // Print out the function frequencies...
 194   outs() << " ##   Frequency\n";
 195   for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i) {
 196     if (FunctionCounts[i].second == 0) {
 197       outs() << "\n  NOTE: " << e-i << " function"
 198         << (e-i-1 ? "s were" : " was") << " never executed!\n";
 199       break;
 200     }
 201
 202     outs() << format("%3d", i+1) << ". "
 203       << format("%5.2g", FunctionCounts[i].second) << "/"
 204       << format("%g", TotalExecutions) << " "
 205       << FunctionCounts[i].first->getNameStr() << "\n";
 206   }
 207
 208   std::set<Function*> FunctionsToPrint;
 209
 210   TotalExecutions = 0;
 211   for (unsigned i = 0, e = Counts.size(); i != e; ++i)
 212     TotalExecutions += Counts[i].second;
 213
 214   // Sort by the frequency, backwards.
 215   sort(Counts.begin(), Counts.end(),
 216        PairSecondSortReverse<BasicBlock*>());
 217
 218   outs() << "\n===" << std::string(73, '-') << "===\n";
 219   outs() << "Top 20 most frequently executed basic blocks:\n\n";
 220
 221   // Print out the function frequencies...
 222   outs() <<" ##      %% \tFrequency\n";
 223   unsigned BlocksToPrint = Counts.size();
 224   if (BlocksToPrint > 20) BlocksToPrint = 20;
 225   for (unsigned i = 0; i != BlocksToPrint; ++i) {
 226     if (Counts[i].second == 0) break;
 227     Function *F = Counts[i].first->getParent();
 228     outs() << format("%3d", i+1) << ". "
 229       << format("%5g", Counts[i].second/(double)TotalExecutions*100) << "% "
 230       << format("%5.0f", Counts[i].second) << "/"
 231       << format("%g", TotalExecutions) << "\t"
 232       << F->getNameStr() << "() - "
 233        << Counts[i].first->getNameStr() << "\n";
 234     FunctionsToPrint.insert(F);
 235   }
 236
 237   if (PrintAnnotatedLLVM || PrintAllCode) {
 238     outs() << "\n===" << std::string(73, '-') << "===\n";
 239     outs() << "Annotated LLVM code for the module:\n\n";
 240
 241     ProfileAnnotator PA(PI);
 242
 243     if (FunctionsToPrint.empty() || PrintAllCode)
 244       M.print(outs(), &PA);
 245     else
 246       // Print just a subset of the functions.
 247       for (std::set<Function*>::iterator I = FunctionsToPrint.begin(),
 248              E = FunctionsToPrint.end(); I != E; ++I)
 249         (*I)->print(outs(), &PA);
 250   }
 251
 252   return false;
 253 }
 254
 255 int main(int argc, char **argv) {
 256   // Print a stack trace if we signal out.
 257   sys::PrintStackTraceOnErrorSignal();
 258   PrettyStackTraceProgram X(argc, argv);
 259
 260   LLVMContext &Context = getGlobalContext();
 261   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 262
 263   cl::ParseCommandLineOptions(argc, argv, "llvm profile dump decoder\n");
 264
 265   // Read in the bitcode file...
 266   std::string ErrorMessage;
 267   OwningPtr<MemoryBuffer> Buffer;
 268   error_code ec;
 269   Module *M = 0;
 270   if (!(ec = MemoryBuffer::getFileOrSTDIN(BitcodeFile, Buffer))) {
 271     M = ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage);
 272   } else
 273     ErrorMessage = ec.message();
 274   if (M == 0) {
 275     errs() << argv[0] << ": " << BitcodeFile << ": "
 276       << ErrorMessage << "\n";
 277     return 1;
 278   }
 279
 280   // Read the profiling information. This is redundant since we load it again
 281   // using the standard profile info provider pass, but for now this gives us
 282   // access to additional information not exposed via the ProfileInfo
 283   // interface.
 284   ProfileInfoLoader PIL(argv[0], ProfileDataFile, *M);
 285
 286   // Run the printer pass.
 287   PassManager PassMgr;
 288   PassMgr.add(createProfileLoaderPass(ProfileDataFile));
 289   PassMgr.add(new ProfileInfoPrinterPass(PIL));
 290   PassMgr.run(*M);
 291
 292   return 0;
 293 }