llvm-prof.cpp revision 065344dfd5a7b3502098810b981eb0077e5d81f3 
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/Bitcode/ReaderWriter.h"
21#include "llvm/Support/CommandLine.h"
22#include "llvm/Support/ManagedStatic.h"
23#include "llvm/Support/MemoryBuffer.h"
24#include "llvm/System/Signals.h"
25#include <algorithm>
26#include <iostream>
27#include <iomanip>
28#include <map>
29#include <set>
30
31using namespace llvm;
32
33namespace {
34  cl::opt<std::string>
35  BytecodeFile(cl::Positional, cl::desc("<program bytecode file>"),
36               cl::Required);
37
38  cl::opt<std::string>
39  ProfileDataFile(cl::Positional, cl::desc("<llvmprof.out file>"),
40                  cl::Optional, cl::init("llvmprof.out"));
41
42  cl::opt<bool>
43  PrintAnnotatedLLVM("annotated-llvm",
44                     cl::desc("Print LLVM code with frequency annotations"));
45  cl::alias PrintAnnotated2("A", cl::desc("Alias for --annotated-llvm"),
46                            cl::aliasopt(PrintAnnotatedLLVM));
47  cl::opt<bool>
48  PrintAllCode("print-all-code",
49               cl::desc("Print annotated code for the entire program"));
50}
51
52// PairSecondSort - A sorting predicate to sort by the second element of a pair.
53template<class T>
54struct PairSecondSortReverse
55  : public std::binary_function<std::pair<T, unsigned>,
56                                std::pair<T, unsigned>, bool> {
57  bool operator()(const std::pair<T, unsigned> &LHS,
58                  const std::pair<T, unsigned> &RHS) const {
59    return LHS.second > RHS.second;
60  }
61};
62
63namespace {
64  class ProfileAnnotator : public AssemblyAnnotationWriter {
65    std::map<const Function  *, unsigned> &FuncFreqs;
66    std::map<const BasicBlock*, unsigned> &BlockFreqs;
67    std::map<ProfileInfoLoader::Edge, unsigned> &EdgeFreqs;
68  public:
69    ProfileAnnotator(std::map<const Function  *, unsigned> &FF,
70                     std::map<const BasicBlock*, unsigned> &BF,
71                     std::map<ProfileInfoLoader::Edge, unsigned> &EF)
72      : FuncFreqs(FF), BlockFreqs(BF), EdgeFreqs(EF) {}
73
74    virtual void emitFunctionAnnot(const Function *F, std::ostream &OS) {
75      OS << ";;; %" << F->getName() << " called " << FuncFreqs[F]
76         << " times.\n;;;\n";
77    }
78    virtual void emitBasicBlockStartAnnot(const BasicBlock *BB,
79                                          std::ostream &OS) {
80      if (BlockFreqs.empty()) return;
81      if (unsigned Count = BlockFreqs[BB])
82        OS << "\t;;; Basic block executed " << Count << " times.\n";
83      else
84        OS << "\t;;; Never executed!\n";
85    }
86
87    virtual void emitBasicBlockEndAnnot(const BasicBlock *BB, std::ostream &OS){
88      if (EdgeFreqs.empty()) return;
89
90      // Figure out how many times each successor executed.
91      std::vector<std::pair<const BasicBlock*, unsigned> > SuccCounts;
92      const TerminatorInst *TI = BB->getTerminator();
93
94      std::map<ProfileInfoLoader::Edge, unsigned>::iterator I =
95        EdgeFreqs.lower_bound(std::make_pair(const_cast<BasicBlock*>(BB), 0U));
96      for (; I != EdgeFreqs.end() && I->first.first == BB; ++I)
97        if (I->second)
98          SuccCounts.push_back(std::make_pair(TI->getSuccessor(I->first.second),
99                                              I->second));
100      if (!SuccCounts.empty()) {
101        OS << "\t;;; Out-edge counts:";
102        for (unsigned i = 0, e = SuccCounts.size(); i != e; ++i)
103          OS << " [" << SuccCounts[i].second << " -> "
104             << SuccCounts[i].first->getName() << "]";
105        OS << "\n";
106      }
107    }
108  };
109}
110
111
112int main(int argc, char **argv) {
113  llvm_shutdown_obj X;  // Call llvm_shutdown() on exit.
114  try {
115    cl::ParseCommandLineOptions(argc, argv, " llvm profile dump decoder\n");
116    sys::PrintStackTraceOnErrorSignal();
117
118    // Read in the bytecode file...
119    std::string ErrorMessage;
120    Module *M;
121    if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(BytecodeFile,
122                                                            &ErrorMessage)) {
123      M = ParseBitcodeFile(Buffer, &ErrorMessage);
124      delete Buffer;
125    }
126    if (M == 0) {
127      std::cerr << argv[0] << ": " << BytecodeFile << ": "
128        << ErrorMessage << "\n";
129      return 1;
130    }
131
132    // Read the profiling information
133    ProfileInfoLoader PI(argv[0], ProfileDataFile, *M);
134
135    std::map<const Function  *, unsigned> FuncFreqs;
136    std::map<const BasicBlock*, unsigned> BlockFreqs;
137    std::map<ProfileInfoLoader::Edge, unsigned> EdgeFreqs;
138
139    // Output a report. Eventually, there will be multiple reports selectable on
140    // the command line, for now, just keep things simple.
141
142    // Emit the most frequent function table...
143    std::vector<std::pair<Function*, unsigned> > FunctionCounts;
144    PI.getFunctionCounts(FunctionCounts);
145    FuncFreqs.insert(FunctionCounts.begin(), FunctionCounts.end());
146
147    // Sort by the frequency, backwards.
148    sort(FunctionCounts.begin(), FunctionCounts.end(),
149              PairSecondSortReverse<Function*>());
150
151    uint64_t TotalExecutions = 0;
152    for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i)
153      TotalExecutions += FunctionCounts[i].second;
154
155    std::cout << "===" << std::string(73, '-') << "===\n"
156              << "LLVM profiling output for execution";
157    if (PI.getNumExecutions() != 1) std::cout << "s";
158    std::cout << ":\n";
159
160    for (unsigned i = 0, e = PI.getNumExecutions(); i != e; ++i) {
161      std::cout << "  ";
162      if (e != 1) std::cout << i+1 << ". ";
163      std::cout << PI.getExecution(i) << "\n";
164    }
165
166    std::cout << "\n===" << std::string(73, '-') << "===\n";
167    std::cout << "Function execution frequencies:\n\n";
168
169    // Print out the function frequencies...
170    std::cout << " ##   Frequency\n";
171    for (unsigned i = 0, e = FunctionCounts.size(); i != e; ++i) {
172      if (FunctionCounts[i].second == 0) {
173        std::cout << "\n  NOTE: " << e-i << " function" <<
174               (e-i-1 ? "s were" : " was") << " never executed!\n";
175        break;
176      }
177
178      std::cout << std::setw(3) << i+1 << ". "
179        << std::setw(5) << FunctionCounts[i].second << "/"
180        << TotalExecutions << " "
181        << FunctionCounts[i].first->getName().c_str() << "\n";
182    }
183
184    std::set<Function*> FunctionsToPrint;
185
186    // If we have block count information, print out the LLVM module with
187    // frequency annotations.
188    if (PI.hasAccurateBlockCounts()) {
189      std::vector<std::pair<BasicBlock*, unsigned> > Counts;
190      PI.getBlockCounts(Counts);
191
192      TotalExecutions = 0;
193      for (unsigned i = 0, e = Counts.size(); i != e; ++i)
194        TotalExecutions += Counts[i].second;
195
196      // Sort by the frequency, backwards.
197      sort(Counts.begin(), Counts.end(),
198                PairSecondSortReverse<BasicBlock*>());
199
200      std::cout << "\n===" << std::string(73, '-') << "===\n";
201      std::cout << "Top 20 most frequently executed basic blocks:\n\n";
202
203      // Print out the function frequencies...
204      std::cout <<" ##      %% \tFrequency\n";
205      unsigned BlocksToPrint = Counts.size();
206      if (BlocksToPrint > 20) BlocksToPrint = 20;
207      for (unsigned i = 0; i != BlocksToPrint; ++i) {
208        if (Counts[i].second == 0) break;
209        Function *F = Counts[i].first->getParent();
210        std::cout << std::setw(3) << i+1 << ". "
211          << std::setw(5) << std::setprecision(2)
212          << Counts[i].second/(double)TotalExecutions*100 << "% "
213          << std::setw(5) << Counts[i].second << "/"
214          << TotalExecutions << "\t"
215          << F->getName().c_str() << "() - "
216          << Counts[i].first->getName().c_str() << "\n";
217        FunctionsToPrint.insert(F);
218      }
219
220      BlockFreqs.insert(Counts.begin(), Counts.end());
221    }
222
223    if (PI.hasAccurateEdgeCounts()) {
224      std::vector<std::pair<ProfileInfoLoader::Edge, unsigned> > Counts;
225      PI.getEdgeCounts(Counts);
226      EdgeFreqs.insert(Counts.begin(), Counts.end());
227    }
228
229    if (PrintAnnotatedLLVM || PrintAllCode) {
230      std::cout << "\n===" << std::string(73, '-') << "===\n";
231      std::cout << "Annotated LLVM code for the module:\n\n";
232
233      ProfileAnnotator PA(FuncFreqs, BlockFreqs, EdgeFreqs);
234
235      if (FunctionsToPrint.empty() || PrintAllCode)
236        M->print(std::cout, &PA);
237      else
238        // Print just a subset of the functions...
239        for (std::set<Function*>::iterator I = FunctionsToPrint.begin(),
240               E = FunctionsToPrint.end(); I != E; ++I)
241          (*I)->print(std::cout, &PA);
242    }
243
244    return 0;
245  } catch (const std::string& msg) {
246    std::cerr << argv[0] << ": " << msg << "\n";
247  } catch (...) {
248    std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
249  }
250  return 1;
251}
252