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