llvm-prof.cpp revision 368820586bafcf620159e2e53c4fed557ab057b5 
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 "ProfileInfo.h"
17#include "llvm/Function.h"
18#include "llvm/Bytecode/Reader.h"
19#include "Support/CommandLine.h"
20#include <iostream>
21#include <cstdio>
22#include <map>
23
24namespace {
25  cl::opt<std::string>
26  BytecodeFile(cl::Positional, cl::desc("<program bytecode file>"),
27               cl::Required);
28
29  cl::opt<std::string>
30  ProfileDataFile(cl::Positional, cl::desc("<llvmprof.out file>"),
31                  cl::Optional, cl::init("llvmprof.out"));
32}
33
34// PairSecondSort - A sorting predicate to sort by the second element of a pair.
35template<class T>
36struct PairSecondSort
37  : public std::binary_function<std::pair<T, unsigned>,
38                                std::pair<T, unsigned>, bool> {
39  bool operator()(const std::pair<T, unsigned> &LHS,
40                  const std::pair<T, unsigned> &RHS) const {
41    return LHS.second < RHS.second;
42  }
43};
44
45
46int main(int argc, char **argv) {
47  cl::ParseCommandLineOptions(argc, argv, " llvm profile dump decoder\n");
48
49  // Read in the bytecode file...
50  std::string ErrorMessage;
51  Module *M = ParseBytecodeFile(BytecodeFile, &ErrorMessage);
52  if (M == 0) {
53    std::cerr << argv[0] << ": " << BytecodeFile << ": " << ErrorMessage
54              << "\n";
55    return 1;
56  }
57
58  // Read the profiling information
59  ProfileInfo PI(argv[0], ProfileDataFile, *M);
60
61  // Output a report.  Eventually, there will be multiple reports selectable on
62  // the command line, for now, just keep things simple.
63
64  // Emit the most frequent function table...
65  std::vector<std::pair<Function*, unsigned> > FunctionCounts;
66  PI.getFunctionCounts(FunctionCounts);
67
68  // Sort by the frequency, backwards.
69  std::sort(FunctionCounts.begin(), FunctionCounts.end(),
70            std::not2(PairSecondSort<Function*>()));
71
72  unsigned TotalExecutions = 0;
73  for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i)
74    TotalExecutions += FunctionCounts[i].second;
75
76  std::cout << "===" << std::string(73, '-') << "===\n"
77            << "LLVM profiling output for execution";
78  if (PI.getNumExecutions() != 1) std::cout << "s";
79  std::cout << ":\n";
80
81  for (unsigned i = 0, e = PI.getNumExecutions(); i != e; ++i) {
82    std::cout << "  ";
83    if (e != 1) std::cout << i << ". ";
84    std::cout << PI.getExecution(i) << "\n";
85  }
86
87  std::cout << "\n===" << std::string(73, '-') << "===\n";
88  std::cout << "Function execution frequencies:\n\n";
89
90  // Print out the function frequencies...
91  printf(" ##   Frequency\n");
92  for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i) {
93    if (FunctionCounts[i].second == 0) {
94      printf("\n  NOTE: %d function%s never executed!\n",
95             e-i, e-i-1 ? "s were" : " was");
96      break;
97    }
98
99    printf("%3d. %5d/%d %s\n", i, FunctionCounts[i].second, TotalExecutions,
100           FunctionCounts[i].first->getName().c_str());
101  }
102
103
104  // If we have block count information, print out the LLVM module with
105  // frequency annotations.
106  if (PI.hasAccurateBlockCounts()) {
107    std::vector<std::pair<BasicBlock*, unsigned> > Counts;
108    PI.getBlockCounts(Counts);
109    std::map<BasicBlock*, unsigned> BlockFreqs(Counts.begin(), Counts.end());
110
111  }
112
113  return 0;
114}
115