Home | History | Annotate | Download | only in llvm-prof 
      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/IR/LLVMContext.h"
     17 #include "llvm/Analysis/Passes.h"
     18 #include "llvm/Analysis/ProfileInfo.h"
     19 #include "llvm/Analysis/ProfileInfoLoader.h"
     20 #include "llvm/Assembly/AssemblyAnnotationWriter.h"
     21 #include "llvm/Bitcode/ReaderWriter.h"
     22 #include "llvm/IR/InstrTypes.h"
     23 #include "llvm/IR/Module.h"
     24 #include "llvm/PassManager.h"
     25 #include "llvm/Support/CommandLine.h"
     26 #include "llvm/Support/Format.h"
     27 #include "llvm/Support/FormattedStream.h"
     28 #include "llvm/Support/ManagedStatic.h"
     29 #include "llvm/Support/MemoryBuffer.h"
     30 #include "llvm/Support/PrettyStackTrace.h"
     31 #include "llvm/Support/Signals.h"
     32 #include "llvm/Support/raw_ostream.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->getName() << "\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->getName() << "() - "
    233            << Counts[i].first->getName() << "\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);
    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 }
    294