llvm-prof.cpp revision 8c2730e347092e2c62ddb8442252e694bc498aa0 
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 "Support/CommandLine.h"
22#include "Support/Signals.h"
23#include <cstdio>
24#include <map>
25#include <set>
26
27using namespace llvm;
28
29namespace {
30  cl::opt<std::string>
31  BytecodeFile(cl::Positional, cl::desc("<program bytecode file>"),
32               cl::Required);
33
34  cl::opt<std::string>
35  ProfileDataFile(cl::Positional, cl::desc("<llvmprof.out file>"),
36                  cl::Optional, cl::init("llvmprof.out"));
37
38  cl::opt<bool>
39  PrintAnnotatedLLVM("annotated-llvm",
40                     cl::desc("Print LLVM code with frequency annotations"));
41  cl::alias PrintAnnotated2("A", cl::desc("Alias for --annotated-llvm"),
42                            cl::aliasopt(PrintAnnotatedLLVM));
43  cl::opt<bool>
44  PrintAllCode("print-all-code",
45               cl::desc("Print annotated code for the entire program"));
46}
47
48// PairSecondSort - A sorting predicate to sort by the second element of a pair.
49template<class T>
50struct PairSecondSortReverse
51  : public std::binary_function<std::pair<T, unsigned>,
52                                std::pair<T, unsigned>, bool> {
53  bool operator()(const std::pair<T, unsigned> &LHS,
54                  const std::pair<T, unsigned> &RHS) const {
55    return LHS.second > RHS.second;
56  }
57};
58
59namespace {
60  class ProfileAnnotator : public AssemblyAnnotationWriter {
61    std::map<const Function  *, unsigned> &FuncFreqs;
62    std::map<const BasicBlock*, unsigned> &BlockFreqs;
63    std::map<ProfileInfoLoader::Edge, unsigned> &EdgeFreqs;
64  public:
65    ProfileAnnotator(std::map<const Function  *, unsigned> &FF,
66                     std::map<const BasicBlock*, unsigned> &BF,
67                     std::map<ProfileInfoLoader::Edge, unsigned> &EF)
68      : FuncFreqs(FF), BlockFreqs(BF), EdgeFreqs(EF) {}
69
70    virtual void emitFunctionAnnot(const Function *F, std::ostream &OS) {
71      OS << ";;; %" << F->getName() << " called " << FuncFreqs[F]
72         << " times.\n;;;\n";
73    }
74    virtual void emitBasicBlockStartAnnot(const BasicBlock *BB,
75                                          std::ostream &OS) {
76      if (BlockFreqs.empty()) return;
77      if (unsigned Count = BlockFreqs[BB])
78        OS << "\t;;; Basic block executed " << Count << " times.\n";
79      else
80        OS << "\t;;; Never executed!\n";
81    }
82
83    virtual void emitBasicBlockEndAnnot(const BasicBlock *BB, std::ostream &OS){
84      if (EdgeFreqs.empty()) return;
85
86      // Figure out how many times each successor executed.
87      std::vector<std::pair<const BasicBlock*, unsigned> > SuccCounts;
88      const TerminatorInst *TI = BB->getTerminator();
89
90      std::map<ProfileInfoLoader::Edge, unsigned>::iterator I =
91        EdgeFreqs.lower_bound(std::make_pair(const_cast<BasicBlock*>(BB), 0U));
92      for (; I != EdgeFreqs.end() && I->first.first == BB; ++I)
93        if (I->second)
94          SuccCounts.push_back(std::make_pair(TI->getSuccessor(I->first.second),
95                                              I->second));
96      if (!SuccCounts.empty()) {
97        OS << "\t;;; Out-edge counts:";
98        for (unsigned i = 0, e = SuccCounts.size(); i != e; ++i)
99          OS << " [" << SuccCounts[i].second << " -> "
100             << SuccCounts[i].first->getName() << "]";
101        OS << "\n";
102      }
103    }
104  };
105}
106
107
108int main(int argc, char **argv) {
109  cl::ParseCommandLineOptions(argc, argv, " llvm profile dump decoder\n");
110  PrintStackTraceOnErrorSignal();
111
112  // Read in the bytecode file...
113  std::string ErrorMessage;
114  Module *M = ParseBytecodeFile(BytecodeFile, &ErrorMessage);
115  if (M == 0) {
116    std::cerr << argv[0] << ": " << BytecodeFile << ": " << ErrorMessage
117              << "\n";
118    return 1;
119  }
120
121  // Read the profiling information
122  ProfileInfoLoader PI(argv[0], ProfileDataFile, *M);
123
124  std::map<const Function  *, unsigned> FuncFreqs;
125  std::map<const BasicBlock*, unsigned> BlockFreqs;
126  std::map<ProfileInfoLoader::Edge, unsigned> EdgeFreqs;
127
128  // Output a report.  Eventually, there will be multiple reports selectable on
129  // the command line, for now, just keep things simple.
130
131  // Emit the most frequent function table...
132  std::vector<std::pair<Function*, unsigned> > FunctionCounts;
133  PI.getFunctionCounts(FunctionCounts);
134  FuncFreqs.insert(FunctionCounts.begin(), FunctionCounts.end());
135
136  // Sort by the frequency, backwards.
137  std::sort(FunctionCounts.begin(), FunctionCounts.end(),
138            PairSecondSortReverse<Function*>());
139
140  unsigned long long TotalExecutions = 0;
141  for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i)
142    TotalExecutions += FunctionCounts[i].second;
143
144  std::cout << "===" << std::string(73, '-') << "===\n"
145            << "LLVM profiling output for execution";
146  if (PI.getNumExecutions() != 1) std::cout << "s";
147  std::cout << ":\n";
148
149  for (unsigned i = 0, e = PI.getNumExecutions(); i != e; ++i) {
150    std::cout << "  ";
151    if (e != 1) std::cout << i+1 << ". ";
152    std::cout << PI.getExecution(i) << "\n";
153  }
154
155  std::cout << "\n===" << std::string(73, '-') << "===\n";
156  std::cout << "Function execution frequencies:\n\n";
157
158  // Print out the function frequencies...
159  printf(" ##   Frequency\n");
160  for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i) {
161    if (FunctionCounts[i].second == 0) {
162      printf("\n  NOTE: %d function%s never executed!\n",
163             e-i, e-i-1 ? "s were" : " was");
164      break;
165    }
166
167    printf("%3d. %5u/%llu %s\n", i+1, FunctionCounts[i].second, TotalExecutions,
168           FunctionCounts[i].first->getName().c_str());
169  }
170
171  std::set<Function*> FunctionsToPrint;
172
173  // If we have block count information, print out the LLVM module with
174  // frequency annotations.
175  if (PI.hasAccurateBlockCounts()) {
176    std::vector<std::pair<BasicBlock*, unsigned> > Counts;
177    PI.getBlockCounts(Counts);
178
179    TotalExecutions = 0;
180    for (unsigned i = 0, e = Counts.size(); i != e; ++i)
181      TotalExecutions += Counts[i].second;
182
183    // Sort by the frequency, backwards.
184    std::sort(Counts.begin(), Counts.end(),
185              PairSecondSortReverse<BasicBlock*>());
186
187    std::cout << "\n===" << std::string(73, '-') << "===\n";
188    std::cout << "Top 20 most frequently executed basic blocks:\n\n";
189
190    // Print out the function frequencies...
191    printf(" ##      %%%% \tFrequency\n");
192    unsigned BlocksToPrint = Counts.size();
193    if (BlocksToPrint > 20) BlocksToPrint = 20;
194    for (unsigned i = 0; i != BlocksToPrint; ++i) {
195      if (Counts[i].second == 0) break;
196      Function *F = Counts[i].first->getParent();
197      printf("%3d. %5.2f%% %5u/%llu\t%s() - %s\n", i+1,
198             Counts[i].second/(double)TotalExecutions*100,
199             Counts[i].second, TotalExecutions,
200             F->getName().c_str(), Counts[i].first->getName().c_str());
201      FunctionsToPrint.insert(F);
202    }
203
204    BlockFreqs.insert(Counts.begin(), Counts.end());
205  }
206
207  if (PI.hasAccurateEdgeCounts()) {
208    std::vector<std::pair<ProfileInfoLoader::Edge, unsigned> > Counts;
209    PI.getEdgeCounts(Counts);
210    EdgeFreqs.insert(Counts.begin(), Counts.end());
211  }
212
213  if (PrintAnnotatedLLVM || PrintAllCode) {
214    std::cout << "\n===" << std::string(73, '-') << "===\n";
215    std::cout << "Annotated LLVM code for the module:\n\n";
216
217    ProfileAnnotator PA(FuncFreqs, BlockFreqs, EdgeFreqs);
218
219    if (FunctionsToPrint.empty() || PrintAllCode)
220      M->print(std::cout, &PA);
221    else
222      // Print just a subset of the functions...
223      for (std::set<Function*>::iterator I = FunctionsToPrint.begin(),
224             E = FunctionsToPrint.end(); I != E; ++I)
225        (*I)->print(std::cout, &PA);
226  }
227
228  return 0;
229}
230