summaryrefslogtreecommitdiff
path: root/lib/Analysis/PathProfileVerifier.cpp
blob: 745d8c60bb5af8e60a72a53d32c11fe2ff982b2f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
//===- PathProfileVerifier.cpp --------------------------------*- C++ -*---===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This verifier derives an edge profile file from current path profile
// information
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "path-profile-verifier"

#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/PathProfileInfo.h"
#include "llvm/Analysis/ProfileInfoTypes.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <stdio.h>

using namespace llvm;

namespace {
  class PathProfileVerifier : public ModulePass {
  private:
    bool runOnModule(Module &M);

  public:
    static char ID; // Pass identification, replacement for typeid
    PathProfileVerifier() : ModulePass(ID) {
      initializePathProfileVerifierPass(*PassRegistry::getPassRegistry());
    }


    virtual const char *getPassName() const {
      return "Path Profiler Verifier";
    }

    // The verifier requires the path profile and edge profile.
    virtual void getAnalysisUsage(AnalysisUsage& AU) const;
  };
}

static cl::opt<std::string>
EdgeProfileFilename("path-profile-verifier-file",
  cl::init("edgefrompath.llvmprof.out"),
  cl::value_desc("filename"),
  cl::desc("Edge profile file generated by -path-profile-verifier"),
  cl::Hidden);

char PathProfileVerifier::ID = 0;
INITIALIZE_PASS(PathProfileVerifier, "path-profile-verifier",
                "Compare the path profile derived edge profile against the "
                "edge profile.", true, true)

ModulePass *llvm::createPathProfileVerifierPass() {
  return new PathProfileVerifier();
}

// The verifier requires the path profile and edge profile.
void PathProfileVerifier::getAnalysisUsage(AnalysisUsage& AU) const {
  AU.addRequired<PathProfileInfo>();
  AU.addPreserved<PathProfileInfo>();
}

typedef std::map<unsigned, unsigned> DuplicateToIndexMap;
typedef std::map<BasicBlock*,DuplicateToIndexMap> BlockToDuplicateMap;
typedef std::map<BasicBlock*,BlockToDuplicateMap> NestedBlockToIndexMap;

// the verifier iterates through each path to gather the total
// number of edge frequencies
bool PathProfileVerifier::runOnModule (Module &M) {
  PathProfileInfo& pathProfileInfo = getAnalysis<PathProfileInfo>();

  // setup a data structure to map path edges which index an
  // array of edge counters
  NestedBlockToIndexMap arrayMap;
  unsigned i = 0;
  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
    if (F->isDeclaration()) continue;

    arrayMap[0][F->begin()][0] = i++;

    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
      TerminatorInst *TI = BB->getTerminator();

      unsigned duplicate = 0;
      BasicBlock* prev = 0;
      for (unsigned s = 0, e = TI->getNumSuccessors(); s != e;
           prev = TI->getSuccessor(s), ++s) {
        if (prev == TI->getSuccessor(s))
          duplicate++;
        else duplicate = 0;

        arrayMap[BB][TI->getSuccessor(s)][duplicate] = i++;
      }
    }
  }

  std::vector<unsigned> edgeArray(i);

  // iterate through each path and increment the edge counters as needed
  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
    if (F->isDeclaration()) continue;

    pathProfileInfo.setCurrentFunction(F);

    DEBUG(dbgs() << "function '" << F->getName() << "' ran "
          << pathProfileInfo.pathsRun()
          << "/" << pathProfileInfo.getPotentialPathCount()
          << " potential paths\n");

    for( ProfilePathIterator nextPath = pathProfileInfo.pathBegin(),
           endPath = pathProfileInfo.pathEnd();
         nextPath != endPath; nextPath++ ) {
      ProfilePath* currentPath = nextPath->second;

      ProfilePathEdgeVector* pev = currentPath->getPathEdges();
      DEBUG(dbgs () << "path #" << currentPath->getNumber() << ": "
            << currentPath->getCount() << "\n");
      // setup the entry edge (normally path profiling doesn't care about this)
      if (currentPath->getFirstBlockInPath() == &F->getEntryBlock())
        edgeArray[arrayMap[0][currentPath->getFirstBlockInPath()][0]]
          += currentPath->getCount();

      for( ProfilePathEdgeIterator nextEdge = pev->begin(),
             endEdge = pev->end(); nextEdge != endEdge; nextEdge++ ) {
        if (nextEdge != pev->begin())
          DEBUG(dbgs() << " :: ");

        BasicBlock* source = nextEdge->getSource();
        BasicBlock* target = nextEdge->getTarget();
        unsigned duplicateNumber = nextEdge->getDuplicateNumber();
        DEBUG(dbgs() << source->getName() << " --{" << duplicateNumber
                     << "}--> " << target->getName());

        // Ensure all the referenced edges exist
        // TODO: make this a separate function
        if( !arrayMap.count(source) ) {
          errs() << "  error [" << F->getName() << "()]: source '"
                 << source->getName()
                 << "' does not exist in the array map.\n";
        } else if( !arrayMap[source].count(target) ) {
          errs() << "  error [" << F->getName() << "()]: target '"
                 << target->getName()
                 << "' does not exist in the array map.\n";
        } else if( !arrayMap[source][target].count(duplicateNumber) ) {
          errs() << "  error [" << F->getName() << "()]: edge "
                 << source->getName() << " -> " << target->getName()
                 << " duplicate number " << duplicateNumber
                 << " does not exist in the array map.\n";
        } else {
          edgeArray[arrayMap[source][target][duplicateNumber]]
            += currentPath->getCount();
        }
      }

      DEBUG(errs() << "\n");

      delete pev;
    }
  }

  std::string errorInfo;
  std::string filename = EdgeProfileFilename;

  // Open a handle to the file
  FILE* edgeFile = fopen(filename.c_str(),"wb");

  if (!edgeFile) {
    errs() << "error: unable to open file '" << filename << "' for output.\n";
    return false;
  }

  errs() << "Generating edge profile '" << filename << "' ...\n";

  // write argument info
  unsigned type = ArgumentInfo;
  unsigned num = pathProfileInfo.argList.size();
  int zeros = 0;

  fwrite(&type,sizeof(unsigned),1,edgeFile);
  fwrite(&num,sizeof(unsigned),1,edgeFile);
  fwrite(pathProfileInfo.argList.c_str(),1,num,edgeFile);
  if (num&3)
    fwrite(&zeros, 1, 4-(num&3), edgeFile);

  type = EdgeInfo;
  num = edgeArray.size();
  fwrite(&type,sizeof(unsigned),1,edgeFile);
  fwrite(&num,sizeof(unsigned),1,edgeFile);

  // write each edge to the file
  for( std::vector<unsigned>::iterator s = edgeArray.begin(),
         e = edgeArray.end(); s != e; s++)
    fwrite(&*s, sizeof (unsigned), 1, edgeFile);

  fclose (edgeFile);

  return true;
}