llvm-prof.cpp revision 3da94aec4d429b2ba0f65fa040c33650cade196b 
1//===- llvm-prof.cpp - Read in and process llvmprof.out data files --------===//
2//
3//                      The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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/Bytecode/Reader.h"
21#include "llvm/Support/CommandLine.h"
22#include "llvm/System/Signals.h"
23#include <cstdio>
24#include <iostream>
25#include <map>
26#include <set>
27
28using namespace llvm;
29
30namespace {
31  cl::opt<std::string>
32  BytecodeFile(cl::Positional, cl::desc("<program bytecode file>"),
33               cl::Required);
34
35  cl::opt<std::string>
36  ProfileDataFile(cl::Positional, cl::desc("<llvmprof.out file>"),
37                  cl::Optional, cl::init("llvmprof.out"));
38
39  cl::opt<bool>
40  PrintAnnotatedLLVM("annotated-llvm",
41                     cl::desc("Print LLVM code with frequency annotations"));
42  cl::alias PrintAnnotated2("A", cl::desc("Alias for --annotated-llvm"),
43                            cl::aliasopt(PrintAnnotatedLLVM));
44  cl::opt<bool>
45  PrintAllCode("print-all-code",
46               cl::desc("Print annotated code for the entire program"));
47}
48
49// PairSecondSort - A sorting predicate to sort by the second element of a pair.
50template<class T>
51struct PairSecondSortReverse
52  : public std::binary_function<std::pair<T, unsigned>,
53                                std::pair<T, unsigned>, bool> {
54  bool operator()(const std::pair<T, unsigned> &LHS,
55                  const std::pair<T, unsigned> &RHS) const {
56    return LHS.second > RHS.second;
57  }
58};
59
60namespace {
61  class ProfileAnnotator : public AssemblyAnnotationWriter {
62    std::map<const Function  *, unsigned> &FuncFreqs;
63    std::map<const BasicBlock*, unsigned> &BlockFreqs;
64    std::map<ProfileInfoLoader::Edge, unsigned> &EdgeFreqs;
65  public:
66    ProfileAnnotator(std::map<const Function  *, unsigned> &FF,
67                     std::map<const BasicBlock*, unsigned> &BF,
68                     std::map<ProfileInfoLoader::Edge, unsigned> &EF)
69      : FuncFreqs(FF), BlockFreqs(BF), EdgeFreqs(EF) {}
70
71    virtual void emitFunctionAnnot(const Function *F, std::ostream &OS) {
72      OS << ";;; %" << F->getName() << " called " << FuncFreqs[F]
73         << " times.\n;;;\n";
74    }
75    virtual void emitBasicBlockStartAnnot(const BasicBlock *BB,
76                                          std::ostream &OS) {
77      if (BlockFreqs.empty()) return;
78      if (unsigned Count = BlockFreqs[BB])
79        OS << "\t;;; Basic block executed " << Count << " times.\n";
80      else
81        OS << "\t;;; Never executed!\n";
82    }
83
84    virtual void emitBasicBlockEndAnnot(const BasicBlock *BB, std::ostream &OS){
85      if (EdgeFreqs.empty()) return;
86
87      // Figure out how many times each successor executed.
88      std::vector<std::pair<const BasicBlock*, unsigned> > SuccCounts;
89      const TerminatorInst *TI = BB->getTerminator();
90
91      std::map<ProfileInfoLoader::Edge, unsigned>::iterator I =
92        EdgeFreqs.lower_bound(std::make_pair(const_cast<BasicBlock*>(BB), 0U));
93      for (; I != EdgeFreqs.end() && I->first.first == BB; ++I)
94        if (I->second)
95          SuccCounts.push_back(std::make_pair(TI->getSuccessor(I->first.second),
96                                              I->second));
97      if (!SuccCounts.empty()) {
98        OS << "\t;;; Out-edge counts:";
99        for (unsigned i = 0, e = SuccCounts.size(); i != e; ++i)
100          OS << " [" << SuccCounts[i].second << " -> "
101             << SuccCounts[i].first->getName() << "]";
102        OS << "\n";
103      }
104    }
105  };
106}
107
108
109int main(int argc, char **argv) {
110  try {
111    cl::ParseCommandLineOptions(argc, argv, " llvm profile dump decoder\n");
112    sys::PrintStackTraceOnErrorSignal();
113
114    // Read in the bytecode file...
115    std::string ErrorMessage;
116    Module *M = ParseBytecodeFile(BytecodeFile, &ErrorMessage);
117    if (M == 0) {
118      std::cerr << argv[0] << ": " << BytecodeFile << ": " << ErrorMessage
119                << "\n";
120      return 1;
121    }
122
123    // Read the profiling information
124    ProfileInfoLoader PI(argv[0], ProfileDataFile, *M);
125
126    std::map<const Function  *, unsigned> FuncFreqs;
127    std::map<const BasicBlock*, unsigned> BlockFreqs;
128    std::map<ProfileInfoLoader::Edge, unsigned> EdgeFreqs;
129
130    // Output a report.  Eventually, there will be multiple reports selectable on
131    // the command line, for now, just keep things simple.
132
133    // Emit the most frequent function table...
134    std::vector<std::pair<Function*, unsigned> > FunctionCounts;
135    PI.getFunctionCounts(FunctionCounts);
136    FuncFreqs.insert(FunctionCounts.begin(), FunctionCounts.end());
137
138    // Sort by the frequency, backwards.
139    std::sort(FunctionCounts.begin(), FunctionCounts.end(),
140              PairSecondSortReverse<Function*>());
141
142    unsigned long long TotalExecutions = 0;
143    for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i)
144      TotalExecutions += FunctionCounts[i].second;
145
146    std::cout << "===" << std::string(73, '-') << "===\n"
147              << "LLVM profiling output for execution";
148    if (PI.getNumExecutions() != 1) std::cout << "s";
149    std::cout << ":\n";
150
151    for (unsigned i = 0, e = PI.getNumExecutions(); i != e; ++i) {
152      std::cout << "  ";
153      if (e != 1) std::cout << i+1 << ". ";
154      std::cout << PI.getExecution(i) << "\n";
155    }
156
157    std::cout << "\n===" << std::string(73, '-') << "===\n";
158    std::cout << "Function execution frequencies:\n\n";
159
160    // Print out the function frequencies...
161    printf(" ##   Frequency\n");
162    for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i) {
163      if (FunctionCounts[i].second == 0) {
164        printf("\n  NOTE: %d function%s never executed!\n",
165               e-i, e-i-1 ? "s were" : " was");
166        break;
167      }
168
169      printf("%3d. %5u/%llu %s\n", i+1, FunctionCounts[i].second, TotalExecutions,
170             FunctionCounts[i].first->getName().c_str());
171    }
172
173    std::set<Function*> FunctionsToPrint;
174
175    // If we have block count information, print out the LLVM module with
176    // frequency annotations.
177    if (PI.hasAccurateBlockCounts()) {
178      std::vector<std::pair<BasicBlock*, unsigned> > Counts;
179      PI.getBlockCounts(Counts);
180
181      TotalExecutions = 0;
182      for (unsigned i = 0, e = Counts.size(); i != e; ++i)
183        TotalExecutions += Counts[i].second;
184
185      // Sort by the frequency, backwards.
186      std::sort(Counts.begin(), Counts.end(),
187                PairSecondSortReverse<BasicBlock*>());
188
189      std::cout << "\n===" << std::string(73, '-') << "===\n";
190      std::cout << "Top 20 most frequently executed basic blocks:\n\n";
191
192      // Print out the function frequencies...
193      printf(" ##      %%%% \tFrequency\n");
194      unsigned BlocksToPrint = Counts.size();
195      if (BlocksToPrint > 20) BlocksToPrint = 20;
196      for (unsigned i = 0; i != BlocksToPrint; ++i) {
197        if (Counts[i].second == 0) break;
198        Function *F = Counts[i].first->getParent();
199        printf("%3d. %5.2f%% %5u/%llu\t%s() - %s\n", i+1,
200               Counts[i].second/(double)TotalExecutions*100,
201               Counts[i].second, TotalExecutions,
202               F->getName().c_str(), Counts[i].first->getName().c_str());
203        FunctionsToPrint.insert(F);
204      }
205
206      BlockFreqs.insert(Counts.begin(), Counts.end());
207    }
208
209    if (PI.hasAccurateEdgeCounts()) {
210      std::vector<std::pair<ProfileInfoLoader::Edge, unsigned> > Counts;
211      PI.getEdgeCounts(Counts);
212      EdgeFreqs.insert(Counts.begin(), Counts.end());
213    }
214
215    if (PrintAnnotatedLLVM || PrintAllCode) {
216      std::cout << "\n===" << std::string(73, '-') << "===\n";
217      std::cout << "Annotated LLVM code for the module:\n\n";
218
219      ProfileAnnotator PA(FuncFreqs, BlockFreqs, EdgeFreqs);
220
221      if (FunctionsToPrint.empty() || PrintAllCode)
222        M->print(std::cout, &PA);
223      else
224        // Print just a subset of the functions...
225        for (std::set<Function*>::iterator I = FunctionsToPrint.begin(),
226               E = FunctionsToPrint.end(); I != E; ++I)
227          (*I)->print(std::cout, &PA);
228    }
229
230    return 0;
231  } catch (const std::string& msg) {
232    std::cerr << argv[0] << ": " << msg << "\n";
233  } catch (...) {
234    std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
235  }
236  return 1;
237}
238