aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Analysis/PathProfileInfo.cpp
blob: b361d3f4fa94b1e5a0eb09f2dd73b24412c861a3 (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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
//===- PathProfileInfo.cpp ------------------------------------*- C++ -*---===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interface used by optimizers to load path profiles,
// and provides a loader pass which reads a path profile file.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "path-profile-info"

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

#include <cstdio>

using namespace llvm;

// command line option for loading path profiles
static cl::opt<std::string>
PathProfileInfoFilename("path-profile-loader-file", cl::init("llvmprof.out"),
  cl::value_desc("filename"),
  cl::desc("Path profile file loaded by -path-profile-loader"), cl::Hidden);

namespace {
  class PathProfileLoaderPass : public ModulePass, public PathProfileInfo {
  public:
    PathProfileLoaderPass() : ModulePass(ID) { }
    ~PathProfileLoaderPass();

    // this pass doesn't change anything (only loads information)
    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
      AU.setPreservesAll();
    }

    // the full name of the loader pass
    virtual const char* getPassName() const {
      return "Path Profiling Information Loader";
    }

    // required since this pass implements multiple inheritance
                virtual void *getAdjustedAnalysisPointer(AnalysisID PI) {
      if (PI == &PathProfileInfo::ID)
        return (PathProfileInfo*)this;
      return this;
    }

    // entry point to run the pass
    bool runOnModule(Module &M);

    // pass identification
    static char ID;

  private:
    // make a reference table to refer to function by number
    void buildFunctionRefs(Module &M);

    // process argument info of a program from the input file
    void handleArgumentInfo();

    // process path number information from the input file
    void handlePathInfo();

    // array of references to the functions in the module
    std::vector<Function*> _functions;

    // path profile file handle
    FILE* _file;

    // path profile file name
    std::string _filename;
  };
}

// register PathLoader
char PathProfileLoaderPass::ID = 0;

INITIALIZE_ANALYSIS_GROUP(PathProfileInfo, "Path Profile Information",
                          NoPathProfileInfo)
INITIALIZE_AG_PASS(PathProfileLoaderPass, PathProfileInfo,
                   "path-profile-loader",
                   "Load path profile information from file",
                   false, true, false)

char &llvm::PathProfileLoaderPassID = PathProfileLoaderPass::ID;

// link PathLoader as a pass, and make it available as an optimisation
ModulePass *llvm::createPathProfileLoaderPass() {
  return new PathProfileLoaderPass;
}

// ----------------------------------------------------------------------------
// PathEdge implementation
//
ProfilePathEdge::ProfilePathEdge (BasicBlock* source, BasicBlock* target,
                                  unsigned duplicateNumber)
  : _source(source), _target(target), _duplicateNumber(duplicateNumber) {}

// ----------------------------------------------------------------------------
// Path implementation
//

ProfilePath::ProfilePath (unsigned int number, unsigned int count,
                          double countStdDev,   PathProfileInfo* ppi)
  : _number(number) , _count(count), _countStdDev(countStdDev), _ppi(ppi) {}

double ProfilePath::getFrequency() const {
  return 100 * double(_count) /
    double(_ppi->_functionPathCounts[_ppi->_currentFunction]);
}

static BallLarusEdge* getNextEdge (BallLarusNode* node,
                                   unsigned int pathNumber) {
  BallLarusEdge* best = 0;

  for( BLEdgeIterator next = node->succBegin(),
         end = node->succEnd(); next != end; next++ ) {
    if( (*next)->getType() != BallLarusEdge::BACKEDGE && // no backedges
        (*next)->getType() != BallLarusEdge::SPLITEDGE && // no split edges
        (*next)->getWeight() <= pathNumber && // weight must be <= pathNumber
        (!best || (best->getWeight() < (*next)->getWeight())) ) // best one?
      best = *next;
  }

  return best;
}

ProfilePathEdgeVector* ProfilePath::getPathEdges() const {
  BallLarusNode* currentNode = _ppi->_currentDag->getRoot ();
  unsigned int increment = _number;
  ProfilePathEdgeVector* pev = new ProfilePathEdgeVector;

  while (currentNode != _ppi->_currentDag->getExit()) {
    BallLarusEdge* next = getNextEdge(currentNode, increment);

    increment -= next->getWeight();

    if( next->getType() != BallLarusEdge::BACKEDGE_PHONY &&
        next->getType() != BallLarusEdge::SPLITEDGE_PHONY &&
        next->getTarget() != _ppi->_currentDag->getExit() )
      pev->push_back(ProfilePathEdge(
                       next->getSource()->getBlock(),
                       next->getTarget()->getBlock(),
                       next->getDuplicateNumber()));

    if( next->getType() == BallLarusEdge::BACKEDGE_PHONY &&
        next->getTarget() == _ppi->_currentDag->getExit() )
      pev->push_back(ProfilePathEdge(
                       next->getRealEdge()->getSource()->getBlock(),
                       next->getRealEdge()->getTarget()->getBlock(),
                       next->getDuplicateNumber()));

    if( next->getType() == BallLarusEdge::SPLITEDGE_PHONY &&
        next->getSource() == _ppi->_currentDag->getRoot() )
      pev->push_back(ProfilePathEdge(
                       next->getRealEdge()->getSource()->getBlock(),
                       next->getRealEdge()->getTarget()->getBlock(),
                       next->getDuplicateNumber()));

    // set the new node
    currentNode = next->getTarget();
  }

  return pev;
}

ProfilePathBlockVector* ProfilePath::getPathBlocks() const {
  BallLarusNode* currentNode = _ppi->_currentDag->getRoot ();
  unsigned int increment = _number;
  ProfilePathBlockVector* pbv = new ProfilePathBlockVector;

  while (currentNode != _ppi->_currentDag->getExit()) {
    BallLarusEdge* next = getNextEdge(currentNode, increment);
    increment -= next->getWeight();

    // add block to the block list if it is a real edge
    if( next->getType() == BallLarusEdge::NORMAL)
      pbv->push_back (currentNode->getBlock());
    // make the back edge the last edge since we are at the end
    else if( next->getTarget() == _ppi->_currentDag->getExit() ) {
      pbv->push_back (currentNode->getBlock());
      pbv->push_back (next->getRealEdge()->getTarget()->getBlock());
    }

    // set the new node
    currentNode = next->getTarget();
  }

  return pbv;
}

BasicBlock* ProfilePath::getFirstBlockInPath() const {
  BallLarusNode* root = _ppi->_currentDag->getRoot();
  BallLarusEdge* edge = getNextEdge(root, _number);

  if( edge && (edge->getType() == BallLarusEdge::BACKEDGE_PHONY ||
               edge->getType() == BallLarusEdge::SPLITEDGE_PHONY) )
    return edge->getTarget()->getBlock();

  return root->getBlock();
}

// ----------------------------------------------------------------------------
// PathProfileInfo implementation
//

// Pass identification
char llvm::PathProfileInfo::ID = 0;

PathProfileInfo::PathProfileInfo () : _currentDag(0) , _currentFunction(0) {
}

PathProfileInfo::~PathProfileInfo() {
  if (_currentDag)
    delete _currentDag;
}

// set the function for which paths are currently begin processed
void PathProfileInfo::setCurrentFunction(Function* F) {
  // Make sure it exists
  if (!F) return;

  if (_currentDag)
    delete _currentDag;

  _currentFunction = F;
  _currentDag = new BallLarusDag(*F);
  _currentDag->init();
  _currentDag->calculatePathNumbers();
}

// get the function for which paths are currently being processed
Function* PathProfileInfo::getCurrentFunction() const {
  return _currentFunction;
}

// get the entry block of the function
BasicBlock* PathProfileInfo::getCurrentFunctionEntry() {
  return _currentDag->getRoot()->getBlock();
}

// return the path based on its number
ProfilePath* PathProfileInfo::getPath(unsigned int number) {
  return _functionPaths[_currentFunction][number];
}

// return the number of paths which a function may potentially execute
unsigned int PathProfileInfo::getPotentialPathCount() {
  return _currentDag ? _currentDag->getNumberOfPaths() : 0;
}

// return an iterator for the beginning of a functions executed paths
ProfilePathIterator PathProfileInfo::pathBegin() {
  return _functionPaths[_currentFunction].begin();
}

// return an iterator for the end of a functions executed paths
ProfilePathIterator PathProfileInfo::pathEnd() {
  return _functionPaths[_currentFunction].end();
}

// returns the total number of paths run in the function
unsigned int PathProfileInfo::pathsRun() {
  return _currentFunction ? _functionPaths[_currentFunction].size() : 0;
}

// ----------------------------------------------------------------------------
// PathLoader implementation
//

// remove all generated paths
PathProfileLoaderPass::~PathProfileLoaderPass() {
  for( FunctionPathIterator funcNext = _functionPaths.begin(),
         funcEnd = _functionPaths.end(); funcNext != funcEnd; funcNext++)
    for( ProfilePathIterator pathNext = funcNext->second.begin(),
           pathEnd = funcNext->second.end(); pathNext != pathEnd; pathNext++)
      delete pathNext->second;
}

// entry point of the pass; this loads and parses a file
bool PathProfileLoaderPass::runOnModule(Module &M) {
  // get the filename and setup the module's function references
  _filename = PathProfileInfoFilename;
  buildFunctionRefs (M);

  if (!(_file = fopen(_filename.c_str(), "rb"))) {
    errs () << "error: input '" << _filename << "' file does not exist.\n";
    return false;
  }

  ProfilingType profType;

  while( fread(&profType, sizeof(ProfilingType), 1, _file) ) {
    switch (profType) {
    case ArgumentInfo:
      handleArgumentInfo ();
      break;
    case PathInfo:
      handlePathInfo ();
      break;
    default:
      errs () << "error: bad path profiling file syntax, " << profType << "\n";
      fclose (_file);
      return false;
    }
  }

  fclose (_file);

  return true;
}

// create a reference table for functions defined in the path profile file
void PathProfileLoaderPass::buildFunctionRefs (Module &M) {
  _functions.push_back(0); // make the 0 index a null pointer

  for (Module::iterator F = M.begin(), E = M.end(); F != E; F++) {
    if (F->isDeclaration())
      continue;
    _functions.push_back(F);
  }
}

// handle command like argument infor in the output file
void PathProfileLoaderPass::handleArgumentInfo() {
  // get the argument list's length
  unsigned savedArgsLength;
  if( fread(&savedArgsLength, sizeof(unsigned), 1, _file) != 1 ) {
    errs() << "warning: argument info header/data mismatch\n";
    return;
  }

  // allocate a buffer, and get the arguments
  char* args = new char[savedArgsLength+1];
  if( fread(args, 1, savedArgsLength, _file) != savedArgsLength )
    errs() << "warning: argument info header/data mismatch\n";

  args[savedArgsLength] = '\0';
  argList = std::string(args);
  delete [] args; // cleanup dynamic string

  // byte alignment
  if (savedArgsLength & 3)
    fseek(_file, 4-(savedArgsLength&3), SEEK_CUR);
}

// Handle path profile information in the output file
void PathProfileLoaderPass::handlePathInfo () {
  // get the number of functions in this profile
  unsigned functionCount;
  if( fread(&functionCount, sizeof(functionCount), 1, _file) != 1 ) {
    errs() << "warning: path info header/data mismatch\n";
    return;
  }

  // gather path information for each function
  for (unsigned i = 0; i < functionCount; i++) {
    PathProfileHeader pathHeader;
    if( fread(&pathHeader, sizeof(pathHeader), 1, _file) != 1 ) {
      errs() << "warning: bad header for path function info\n";
      break;
    }

    Function* f = _functions[pathHeader.fnNumber];

    // dynamically allocate a table to store path numbers
    PathProfileTableEntry* pathTable =
      new PathProfileTableEntry[pathHeader.numEntries];

    if( fread(pathTable, sizeof(PathProfileTableEntry),
              pathHeader.numEntries, _file) != pathHeader.numEntries) {
      delete [] pathTable;
      errs() << "warning: path function info header/data mismatch\n";
      return;
    }

    // Build a new path for the current function
    unsigned int totalPaths = 0;
    for (unsigned int j = 0; j < pathHeader.numEntries; j++) {
      totalPaths += pathTable[j].pathCounter;
      _functionPaths[f][pathTable[j].pathNumber]
        = new ProfilePath(pathTable[j].pathNumber, pathTable[j].pathCounter,
                          0, this);
    }

    _functionPathCounts[f] = totalPaths;

    delete [] pathTable;
  }
}

//===----------------------------------------------------------------------===//
//  NoProfile PathProfileInfo implementation
//

namespace {
  struct NoPathProfileInfo : public ImmutablePass, public PathProfileInfo {
    static char ID; // Class identification, replacement for typeinfo
    NoPathProfileInfo() : ImmutablePass(ID) {
      initializeNoPathProfileInfoPass(*PassRegistry::getPassRegistry());
    }

    /// getAdjustedAnalysisPointer - This method is used when a pass implements
    /// an analysis interface through multiple inheritance.  If needed, it
    /// should override this to adjust the this pointer as needed for the
    /// specified pass info.
    virtual void *getAdjustedAnalysisPointer(AnalysisID PI) {
      if (PI == &PathProfileInfo::ID)
        return (PathProfileInfo*)this;
      return this;
    }

    virtual const char *getPassName() const {
      return "NoPathProfileInfo";
    }
  };
}  // End of anonymous namespace

char NoPathProfileInfo::ID = 0;
// Register this pass...
INITIALIZE_AG_PASS(NoPathProfileInfo, PathProfileInfo, "no-path-profile",
                   "No Path Profile Information", false, true, true)

ImmutablePass *llvm::createNoPathProfileInfoPass() { return new NoPathProfileInfo(); }