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/AsmAnnotationWriter.h"
  21 #include "llvm/Analysis/ProfileInfo.h"
  22 #include "llvm/Analysis/ProfileInfoLoader.h"
  23 #include "llvm/Bitcode/ReaderWriter.h"
  24 #include "llvm/Support/CommandLine.h"
  25 #include "llvm/Support/ManagedStatic.h"
  26 #include "llvm/Support/MemoryBuffer.h"
  27 #include "llvm/Support/PrettyStackTrace.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/System/Signals.h"
  30 #include <algorithm>
  31 #include <iostream>
  32 #include <iomanip>
  33 #include <map>
  34 #include <set>
  35
  36 using namespace llvm;
  37
  38 namespace {
  39   cl::opt<std::string>
  40   BitcodeFile(cl::Positional, cl::desc("<program bitcode file>"),
  41               cl::Required);
  42
  43   cl::opt<std::string>
  44   ProfileDataFile(cl::Positional, cl::desc("<llvmprof.out file>"),
  45                   cl::Optional, cl::init("llvmprof.out"));
  46
  47   cl::opt<bool>
  48   PrintAnnotatedLLVM("annotated-llvm",
  49                      cl::desc("Print LLVM code with frequency annotations"));
  50   cl::alias PrintAnnotated2("A", cl::desc("Alias for --annotated-llvm"),
  51                             cl::aliasopt(PrintAnnotatedLLVM));
  52   cl::opt<bool>
  53   PrintAllCode("print-all-code",
  54                cl::desc("Print annotated code for the entire program"));
  55 }
  56
  57 // PairSecondSort - A sorting predicate to sort by the second element of a pair.
  58 template<class T>
  59 struct PairSecondSortReverse
  60   : public std::binary_function<std::pair<T, unsigned>,
  61                                 std::pair<T, unsigned>, bool> {
  62   bool operator()(const std::pair<T, unsigned> &LHS,
  63                   const std::pair<T, unsigned> &RHS) const {
  64     return LHS.second > RHS.second;
  65   }
  66 };
  67
  68 namespace {
  69   class ProfileAnnotator : public AssemblyAnnotationWriter {
  70     std::map<const Function  *, unsigned> &FuncFreqs;
  71     std::map<const BasicBlock*, unsigned> &BlockFreqs;
  72     std::map<ProfileInfoLoader::Edge, unsigned> &EdgeFreqs;
  73   public:
  74     ProfileAnnotator(std::map<const Function  *, unsigned> &FF,
  75                      std::map<const BasicBlock*, unsigned> &BF,
  76                      std::map<ProfileInfoLoader::Edge, unsigned> &EF)
  77       : FuncFreqs(FF), BlockFreqs(BF), EdgeFreqs(EF) {}
  78
  79     virtual void emitFunctionAnnot(const Function *F, raw_ostream &OS) {
  80       OS << ";;; %" << F->getName() << " called " << FuncFreqs[F]
  81          << " times.\n;;;\n";
  82     }
  83     virtual void emitBasicBlockStartAnnot(const BasicBlock *BB,
  84                                           raw_ostream &OS) {
  85       if (BlockFreqs.empty()) return;
  86       std::map<const BasicBlock *, unsigned>::const_iterator I =
  87         BlockFreqs.find(BB);
  88       if (I != BlockFreqs.end())
  89         OS << "\t;;; Basic block executed " << I->second << " times.\n";
  90       else
  91         OS << "\t;;; Never executed!\n";
  92     }
  93
  94     virtual void emitBasicBlockEndAnnot(const BasicBlock *BB, raw_ostream &OS) {
  95       if (EdgeFreqs.empty()) return;
  96
  97       // Figure out how many times each successor executed.
  98       std::vector<std::pair<const BasicBlock*, unsigned> > SuccCounts;
  99       const TerminatorInst *TI = BB->getTerminator();
 100
 101       std::map<ProfileInfoLoader::Edge, unsigned>::iterator I =
 102         EdgeFreqs.lower_bound(std::make_pair(const_cast<BasicBlock*>(BB), 0U));
 103       for (; I != EdgeFreqs.end() && I->first.first == BB; ++I)
 104         if (I->second)
 105           SuccCounts.push_back(std::make_pair(TI->getSuccessor(I->first.second),
 106                                               I->second));
 107       if (!SuccCounts.empty()) {
 108         OS << "\t;;; Out-edge counts:";
 109         for (unsigned i = 0, e = SuccCounts.size(); i != e; ++i)
 110           OS << " [" << SuccCounts[i].second << " -> "
 111              << SuccCounts[i].first->getName() << "]";
 112         OS << "\n";
 113       }
 114     }
 115   };
 116 }
 117
 118 namespace {
 119   /// ProfileInfoPrinterPass - Helper pass to dump the profile information for
 120   /// a module.
 121   //
 122   // FIXME: This should move elsewhere.
 123   class ProfileInfoPrinterPass : public ModulePass {
 124     ProfileInfoLoader &PIL;
 125   public:
 126     static char ID; // Class identification, replacement for typeinfo.
 127     explicit ProfileInfoPrinterPass(ProfileInfoLoader &_PIL)
 128       : ModulePass(&ID), PIL(_PIL) {}
 129
 130     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 131       AU.setPreservesAll();
 132       AU.addRequired<ProfileInfo>();
 133     }
 134
 135     bool runOnModule(Module &M);
 136   };
 137 }
 138
 139 char ProfileInfoPrinterPass::ID = 0;
 140
 141 bool ProfileInfoPrinterPass::runOnModule(Module &M) {
 142   std::map<const Function  *, unsigned> FuncFreqs;
 143   std::map<const BasicBlock*, unsigned> BlockFreqs;
 144   std::map<ProfileInfoLoader::Edge, unsigned> EdgeFreqs;
 145
 146   // Output a report. Eventually, there will be multiple reports selectable on
 147   // the command line, for now, just keep things simple.
 148
 149   // Emit the most frequent function table...
 150   std::vector<std::pair<Function*, unsigned> > FunctionCounts;
 151   PIL.getFunctionCounts(FunctionCounts);
 152   FuncFreqs.insert(FunctionCounts.begin(), FunctionCounts.end());
 153
 154   // Sort by the frequency, backwards.
 155   sort(FunctionCounts.begin(), FunctionCounts.end(),
 156             PairSecondSortReverse<Function*>());
 157
 158   uint64_t TotalExecutions = 0;
 159   for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i)
 160     TotalExecutions += FunctionCounts[i].second;
 161
 162   std::cout << "===" << std::string(73, '-') << "===\n"
 163             << "LLVM profiling output for execution";
 164   if (PIL.getNumExecutions() != 1) std::cout << "s";
 165   std::cout << ":\n";
 166
 167   for (unsigned i = 0, e = PIL.getNumExecutions(); i != e; ++i) {
 168     std::cout << "  ";
 169     if (e != 1) std::cout << i+1 << ". ";
 170     std::cout << PIL.getExecution(i) << "\n";
 171   }
 172
 173   std::cout << "\n===" << std::string(73, '-') << "===\n";
 174   std::cout << "Function execution frequencies:\n\n";
 175
 176   // Print out the function frequencies...
 177   std::cout << " ##   Frequency\n";
 178   for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i) {
 179     if (FunctionCounts[i].second == 0) {
 180       std::cout << "\n  NOTE: " << e-i << " function" <<
 181              (e-i-1 ? "s were" : " was") << " never executed!\n";
 182       break;
 183     }
 184
 185     std::cout << std::setw(3) << i+1 << ". "
 186       << std::setw(5) << FunctionCounts[i].second << "/"
 187       << TotalExecutions << " "
 188       << FunctionCounts[i].first->getNameStr() << "\n";
 189   }
 190
 191   std::set<Function*> FunctionsToPrint;
 192
 193   // If we have block count information, print out the LLVM module with
 194   // frequency annotations.
 195   if (PIL.hasAccurateBlockCounts()) {
 196     std::vector<std::pair<BasicBlock*, unsigned> > Counts;
 197     PIL.getBlockCounts(Counts);
 198
 199     TotalExecutions = 0;
 200     for (unsigned i = 0, e = Counts.size(); i != e; ++i)
 201       TotalExecutions += Counts[i].second;
 202
 203     // Sort by the frequency, backwards.
 204     sort(Counts.begin(), Counts.end(),
 205               PairSecondSortReverse<BasicBlock*>());
 206
 207     std::cout << "\n===" << std::string(73, '-') << "===\n";
 208     std::cout << "Top 20 most frequently executed basic blocks:\n\n";
 209
 210     // Print out the function frequencies...
 211     std::cout <<" ##      %% \tFrequency\n";
 212     unsigned BlocksToPrint = Counts.size();
 213     if (BlocksToPrint > 20) BlocksToPrint = 20;
 214     for (unsigned i = 0; i != BlocksToPrint; ++i) {
 215       if (Counts[i].second == 0) break;
 216       Function *F = Counts[i].first->getParent();
 217       std::cout << std::setw(3) << i+1 << ". "
 218         << std::setw(5) << std::setprecision(2)
 219         << Counts[i].second/(double)TotalExecutions*100 << "% "
 220         << std::setw(5) << Counts[i].second << "/"
 221         << TotalExecutions << "\t"
 222         << F->getNameStr() << "() - "
 223         << Counts[i].first->getNameStr() << "\n";
 224       FunctionsToPrint.insert(F);
 225     }
 226
 227     BlockFreqs.insert(Counts.begin(), Counts.end());
 228   }
 229
 230   if (PIL.hasAccurateEdgeCounts()) {
 231     std::vector<std::pair<ProfileInfoLoader::Edge, unsigned> > Counts;
 232     PIL.getEdgeCounts(Counts);
 233     EdgeFreqs.insert(Counts.begin(), Counts.end());
 234   }
 235
 236   if (PrintAnnotatedLLVM || PrintAllCode) {
 237     std::cout << "\n===" << std::string(73, '-') << "===\n";
 238     std::cout << "Annotated LLVM code for the module:\n\n";
 239
 240     ProfileAnnotator PA(FuncFreqs, BlockFreqs, EdgeFreqs);
 241
 242     if (FunctionsToPrint.empty() || PrintAllCode)
 243       M.print(std::cout, &PA);
 244     else
 245       // Print just a subset of the functions.
 246       for (std::set<Function*>::iterator I = FunctionsToPrint.begin(),
 247              E = FunctionsToPrint.end(); I != E; ++I)
 248         (*I)->print(std::cout, &PA);
 249   }
 250
 251   return false;
 252 }
 253
 254 int main(int argc, char **argv) {
 255   // Print a stack trace if we signal out.
 256   sys::PrintStackTraceOnErrorSignal();
 257   PrettyStackTraceProgram X(argc, argv);
 258
 259   LLVMContext &Context = getGlobalContext();
 260   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 261   try {
 262     cl::ParseCommandLineOptions(argc, argv, "llvm profile dump decoder\n");
 263
 264     // Read in the bitcode file...
 265     std::string ErrorMessage;
 266     Module *M = 0;
 267     if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(BitcodeFile,
 268                                                             &ErrorMessage)) {
 269       M = ParseBitcodeFile(Buffer, Context, &ErrorMessage);
 270       delete Buffer;
 271     }
 272     if (M == 0) {
 273       errs() << argv[0] << ": " << BitcodeFile << ": "
 274         << ErrorMessage << "\n";
 275       return 1;
 276     }
 277
 278     // Read the profiling information. This is redundant since we load it again
 279     // using the standard profile info provider pass, but for now this gives us
 280     // access to additional information not exposed via the ProfileInfo
 281     // interface.
 282     ProfileInfoLoader PIL(argv[0], ProfileDataFile, *M);
 283
 284     // Run the printer pass.
 285     PassManager PassMgr;
 286     PassMgr.add(createProfileLoaderPass(ProfileDataFile));
 287     PassMgr.add(new ProfileInfoPrinterPass(PIL));
 288     PassMgr.run(*M);
 289
 290     return 0;
 291   } catch (const std::string& msg) {
 292     errs() << argv[0] << ": " << msg << "\n";
 293   } catch (...) {
 294     errs() << argv[0] << ": Unexpected unknown exception occurred.\n";
 295   }
 296
 297   return 1;
 298 }