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