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