MemoryDependenceAnalysis.cpp revision e79be944c8ced0a0cb80ede8cb9f97e4fdc6778f
1//===- MemoryDependenceAnalysis.cpp - Mem Deps Implementation --*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements an analysis that determines, for a given memory 11// operation, what preceding memory operations it depends on. It builds on 12// alias analysis information, and tries to provide a lazy, caching interface to 13// a common kind of alias information query. 14// 15//===----------------------------------------------------------------------===// 16 17#define DEBUG_TYPE "memdep" 18#include "llvm/Analysis/MemoryDependenceAnalysis.h" 19#include "llvm/Constants.h" 20#include "llvm/Instructions.h" 21#include "llvm/Function.h" 22#include "llvm/Analysis/AliasAnalysis.h" 23#include "llvm/ADT/Statistic.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/CFG.h" 26#include "llvm/Support/CommandLine.h" 27#include "llvm/Support/Debug.h" 28#include "llvm/Target/TargetData.h" 29using namespace llvm; 30 31STATISTIC(NumCacheNonLocal, "Number of fully cached non-local responses"); 32STATISTIC(NumCacheDirtyNonLocal, "Number of dirty cached non-local responses"); 33STATISTIC(NumUncacheNonLocal, "Number of uncached non-local responses"); 34char MemoryDependenceAnalysis::ID = 0; 35 36// Register this pass... 37static RegisterPass<MemoryDependenceAnalysis> X("memdep", 38 "Memory Dependence Analysis", false, true); 39 40/// getAnalysisUsage - Does not modify anything. It uses Alias Analysis. 41/// 42void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { 43 AU.setPreservesAll(); 44 AU.addRequiredTransitive<AliasAnalysis>(); 45 AU.addRequiredTransitive<TargetData>(); 46} 47 48bool MemoryDependenceAnalysis::runOnFunction(Function &) { 49 AA = &getAnalysis<AliasAnalysis>(); 50 TD = &getAnalysis<TargetData>(); 51 return false; 52} 53 54 55/// getCallSiteDependencyFrom - Private helper for finding the local 56/// dependencies of a call site. 57MemDepResult MemoryDependenceAnalysis:: 58getCallSiteDependencyFrom(CallSite CS, BasicBlock::iterator ScanIt, 59 BasicBlock *BB) { 60 // Walk backwards through the block, looking for dependencies 61 while (ScanIt != BB->begin()) { 62 Instruction *Inst = --ScanIt; 63 64 // If this inst is a memory op, get the pointer it accessed 65 Value *Pointer = 0; 66 uint64_t PointerSize = 0; 67 if (StoreInst *S = dyn_cast<StoreInst>(Inst)) { 68 Pointer = S->getPointerOperand(); 69 PointerSize = TD->getTypeStoreSize(S->getOperand(0)->getType()); 70 } else if (VAArgInst *V = dyn_cast<VAArgInst>(Inst)) { 71 Pointer = V->getOperand(0); 72 PointerSize = TD->getTypeStoreSize(V->getType()); 73 } else if (FreeInst *F = dyn_cast<FreeInst>(Inst)) { 74 Pointer = F->getPointerOperand(); 75 76 // FreeInsts erase the entire structure 77 PointerSize = ~0UL; 78 } else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) { 79 CallSite InstCS = CallSite::get(Inst); 80 // If these two calls do not interfere, look past it. 81 if (AA->getModRefInfo(CS, InstCS) == AliasAnalysis::NoModRef) 82 continue; 83 84 // FIXME: If this is a ref/ref result, we should ignore it! 85 // X = strlen(P); 86 // Y = strlen(Q); 87 // Z = strlen(P); // Z = X 88 89 // If they interfere, we generally return clobber. However, if they are 90 // calls to the same read-only functions we return Def. 91 if (!AA->onlyReadsMemory(CS) || CS.getCalledFunction() == 0 || 92 CS.getCalledFunction() != InstCS.getCalledFunction()) 93 return MemDepResult::getClobber(Inst); 94 return MemDepResult::getDef(Inst); 95 } else { 96 // Non-memory instruction. 97 continue; 98 } 99 100 if (AA->getModRefInfo(CS, Pointer, PointerSize) != AliasAnalysis::NoModRef) 101 return MemDepResult::getClobber(Inst); 102 } 103 104 // No dependence found. 105 return MemDepResult::getNonLocal(); 106} 107 108/// getPointerDependencyFrom - Return the instruction on which a memory 109/// location depends. If isLoad is true, this routine ignore may-aliases with 110/// read-only operations. 111MemDepResult MemoryDependenceAnalysis:: 112getPointerDependencyFrom(Value *MemPtr, uint64_t MemSize, bool isLoad, 113 BasicBlock::iterator ScanIt, BasicBlock *BB) { 114 // The first instruction in a block is always non-local. 115 if (ScanIt == BB->begin()) 116 return MemDepResult::getNonLocal(); 117 118 // Walk backwards through the basic block, looking for dependencies 119 while (ScanIt != BB->begin()) { 120 Instruction *Inst = --ScanIt; 121 122 // Values depend on loads if the pointers are must aliased. This means that 123 // a load depends on another must aliased load from the same value. 124 if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) { 125 Value *Pointer = LI->getPointerOperand(); 126 uint64_t PointerSize = TD->getTypeStoreSize(LI->getType()); 127 128 // If we found a pointer, check if it could be the same as our pointer. 129 AliasAnalysis::AliasResult R = 130 AA->alias(Pointer, PointerSize, MemPtr, MemSize); 131 if (R == AliasAnalysis::NoAlias) 132 continue; 133 134 // May-alias loads don't depend on each other without a dependence. 135 if (isLoad && R == AliasAnalysis::MayAlias) 136 continue; 137 return MemDepResult::getDef(Inst); 138 } 139 140 if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) { 141 Value *Pointer = SI->getPointerOperand(); 142 uint64_t PointerSize = TD->getTypeStoreSize(SI->getOperand(0)->getType()); 143 144 // If we found a pointer, check if it could be the same as our pointer. 145 AliasAnalysis::AliasResult R = 146 AA->alias(Pointer, PointerSize, MemPtr, MemSize); 147 148 if (R == AliasAnalysis::NoAlias) 149 continue; 150 if (R == AliasAnalysis::MayAlias) 151 return MemDepResult::getClobber(Inst); 152 return MemDepResult::getDef(Inst); 153 } 154 155 // If this is an allocation, and if we know that the accessed pointer is to 156 // the allocation, return Def. This means that there is no dependence and 157 // the access can be optimized based on that. For example, a load could 158 // turn into undef. 159 if (AllocationInst *AI = dyn_cast<AllocationInst>(Inst)) { 160 Value *AccessPtr = MemPtr->getUnderlyingObject(); 161 162 if (AccessPtr == AI || 163 AA->alias(AI, 1, AccessPtr, 1) == AliasAnalysis::MustAlias) 164 return MemDepResult::getDef(AI); 165 continue; 166 } 167 168 // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer. 169 // FIXME: If this is a load, we should ignore readonly calls! 170 if (AA->getModRefInfo(Inst, MemPtr, MemSize) == AliasAnalysis::NoModRef) 171 continue; 172 173 // Otherwise, there is a dependence. 174 return MemDepResult::getClobber(Inst); 175 } 176 177 // If we found nothing, return the non-local flag. 178 return MemDepResult::getNonLocal(); 179} 180 181/// getDependency - Return the instruction on which a memory operation 182/// depends. 183MemDepResult MemoryDependenceAnalysis::getDependency(Instruction *QueryInst) { 184 Instruction *ScanPos = QueryInst; 185 186 // Check for a cached result 187 MemDepResult &LocalCache = LocalDeps[QueryInst]; 188 189 // If the cached entry is non-dirty, just return it. Note that this depends 190 // on MemDepResult's default constructing to 'dirty'. 191 if (!LocalCache.isDirty()) 192 return LocalCache; 193 194 // Otherwise, if we have a dirty entry, we know we can start the scan at that 195 // instruction, which may save us some work. 196 if (Instruction *Inst = LocalCache.getInst()) { 197 ScanPos = Inst; 198 199 SmallPtrSet<Instruction*, 4> &InstMap = ReverseLocalDeps[Inst]; 200 InstMap.erase(QueryInst); 201 if (InstMap.empty()) 202 ReverseLocalDeps.erase(Inst); 203 } 204 205 BasicBlock *QueryParent = QueryInst->getParent(); 206 207 Value *MemPtr = 0; 208 uint64_t MemSize = 0; 209 210 // Do the scan. 211 if (BasicBlock::iterator(QueryInst) == QueryParent->begin()) { 212 // First instruction in the block -> non local. 213 LocalCache = MemDepResult::getNonLocal(); 214 } else if (StoreInst *SI = dyn_cast<StoreInst>(QueryInst)) { 215 // If this is a volatile store, don't mess around with it. Just return the 216 // previous instruction as a clobber. 217 if (SI->isVolatile()) 218 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); 219 else { 220 MemPtr = SI->getPointerOperand(); 221 MemSize = TD->getTypeStoreSize(SI->getOperand(0)->getType()); 222 } 223 } else if (LoadInst *LI = dyn_cast<LoadInst>(QueryInst)) { 224 // If this is a volatile load, don't mess around with it. Just return the 225 // previous instruction as a clobber. 226 if (LI->isVolatile()) 227 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); 228 else { 229 MemPtr = LI->getPointerOperand(); 230 MemSize = TD->getTypeStoreSize(LI->getType()); 231 } 232 } else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)) { 233 LocalCache = getCallSiteDependencyFrom(CallSite::get(QueryInst), ScanPos, 234 QueryParent); 235 } else if (FreeInst *FI = dyn_cast<FreeInst>(QueryInst)) { 236 MemPtr = FI->getPointerOperand(); 237 // FreeInsts erase the entire structure, not just a field. 238 MemSize = ~0UL; 239 } else { 240 // Non-memory instruction. 241 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); 242 } 243 244 // If we need to do a pointer scan, make it happen. 245 if (MemPtr) 246 LocalCache = getPointerDependencyFrom(MemPtr, MemSize, 247 isa<LoadInst>(QueryInst), 248 ScanPos, QueryParent); 249 250 // Remember the result! 251 if (Instruction *I = LocalCache.getInst()) 252 ReverseLocalDeps[I].insert(QueryInst); 253 254 return LocalCache; 255} 256 257/// getNonLocalDependency - Perform a full dependency query for the 258/// specified instruction, returning the set of blocks that the value is 259/// potentially live across. The returned set of results will include a 260/// "NonLocal" result for all blocks where the value is live across. 261/// 262/// This method assumes the instruction returns a "nonlocal" dependency 263/// within its own block. 264/// 265const MemoryDependenceAnalysis::NonLocalDepInfo & 266MemoryDependenceAnalysis::getNonLocalDependency(Instruction *QueryInst) { 267 assert(isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst) || 268 isa<LoadInst>(QueryInst) || isa<StoreInst>(QueryInst)); 269 assert(getDependency(QueryInst).isNonLocal() && 270 "getNonLocalDependency should only be used on insts with non-local deps!"); 271 PerInstNLInfo &CacheP = NonLocalDeps[QueryInst]; 272 NonLocalDepInfo &Cache = CacheP.first; 273 274 /// DirtyBlocks - This is the set of blocks that need to be recomputed. In 275 /// the cached case, this can happen due to instructions being deleted etc. In 276 /// the uncached case, this starts out as the set of predecessors we care 277 /// about. 278 SmallVector<BasicBlock*, 32> DirtyBlocks; 279 280 if (!Cache.empty()) { 281 // Okay, we have a cache entry. If we know it is not dirty, just return it 282 // with no computation. 283 if (!CacheP.second) { 284 NumCacheNonLocal++; 285 return Cache; 286 } 287 288 // If we already have a partially computed set of results, scan them to 289 // determine what is dirty, seeding our initial DirtyBlocks worklist. 290 for (NonLocalDepInfo::iterator I = Cache.begin(), E = Cache.end(); 291 I != E; ++I) 292 if (I->second.isDirty()) 293 DirtyBlocks.push_back(I->first); 294 295 // Sort the cache so that we can do fast binary search lookups below. 296 std::sort(Cache.begin(), Cache.end()); 297 298 ++NumCacheDirtyNonLocal; 299 //cerr << "CACHED CASE: " << DirtyBlocks.size() << " dirty: " 300 // << Cache.size() << " cached: " << *QueryInst; 301 } else { 302 // Seed DirtyBlocks with each of the preds of QueryInst's block. 303 BasicBlock *QueryBB = QueryInst->getParent(); 304 DirtyBlocks.append(pred_begin(QueryBB), pred_end(QueryBB)); 305 NumUncacheNonLocal++; 306 } 307 308 // Visited checked first, vector in sorted order. 309 SmallPtrSet<BasicBlock*, 64> Visited; 310 311 unsigned NumSortedEntries = Cache.size(); 312 313 // Iterate while we still have blocks to update. 314 while (!DirtyBlocks.empty()) { 315 BasicBlock *DirtyBB = DirtyBlocks.back(); 316 DirtyBlocks.pop_back(); 317 318 // Already processed this block? 319 if (!Visited.insert(DirtyBB)) 320 continue; 321 322 // Do a binary search to see if we already have an entry for this block in 323 // the cache set. If so, find it. 324 NonLocalDepInfo::iterator Entry = 325 std::upper_bound(Cache.begin(), Cache.begin()+NumSortedEntries, 326 std::make_pair(DirtyBB, MemDepResult())); 327 if (Entry != Cache.begin() && (&*Entry)[-1].first == DirtyBB) 328 --Entry; 329 330 MemDepResult *ExistingResult = 0; 331 if (Entry != Cache.begin()+NumSortedEntries && 332 Entry->first == DirtyBB) { 333 // If we already have an entry, and if it isn't already dirty, the block 334 // is done. 335 if (!Entry->second.isDirty()) 336 continue; 337 338 // Otherwise, remember this slot so we can update the value. 339 ExistingResult = &Entry->second; 340 } 341 342 // If the dirty entry has a pointer, start scanning from it so we don't have 343 // to rescan the entire block. 344 BasicBlock::iterator ScanPos = DirtyBB->end(); 345 if (ExistingResult) { 346 if (Instruction *Inst = ExistingResult->getInst()) { 347 ScanPos = Inst; 348 349 // We're removing QueryInst's use of Inst. 350 SmallPtrSet<Instruction*, 4> &InstMap = ReverseNonLocalDeps[Inst]; 351 InstMap.erase(QueryInst); 352 if (InstMap.empty()) ReverseNonLocalDeps.erase(Inst); 353 } 354 } 355 356 // Find out if this block has a local dependency for QueryInst. 357 MemDepResult Dep; 358 359 Value *MemPtr = 0; 360 uint64_t MemSize = 0; 361 362 if (BasicBlock::iterator(QueryInst) == DirtyBB->begin()) { 363 // First instruction in the block -> non local. 364 Dep = MemDepResult::getNonLocal(); 365 } else if (StoreInst *SI = dyn_cast<StoreInst>(QueryInst)) { 366 // If this is a volatile store, don't mess around with it. Just return the 367 // previous instruction as a clobber. 368 if (SI->isVolatile()) 369 Dep = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); 370 else { 371 MemPtr = SI->getPointerOperand(); 372 MemSize = TD->getTypeStoreSize(SI->getOperand(0)->getType()); 373 } 374 } else if (LoadInst *LI = dyn_cast<LoadInst>(QueryInst)) { 375 // If this is a volatile load, don't mess around with it. Just return the 376 // previous instruction as a clobber. 377 if (LI->isVolatile()) 378 Dep = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); 379 else { 380 MemPtr = LI->getPointerOperand(); 381 MemSize = TD->getTypeStoreSize(LI->getType()); 382 } 383 } else { 384 assert(isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)); 385 Dep = getCallSiteDependencyFrom(CallSite::get(QueryInst), ScanPos, 386 DirtyBB); 387 } 388 389 if (MemPtr) 390 Dep = getPointerDependencyFrom(MemPtr, MemSize, isa<LoadInst>(QueryInst), 391 ScanPos, DirtyBB); 392 393 // If we had a dirty entry for the block, update it. Otherwise, just add 394 // a new entry. 395 if (ExistingResult) 396 *ExistingResult = Dep; 397 else 398 Cache.push_back(std::make_pair(DirtyBB, Dep)); 399 400 // If the block has a dependency (i.e. it isn't completely transparent to 401 // the value), remember the association! 402 if (!Dep.isNonLocal()) { 403 // Keep the ReverseNonLocalDeps map up to date so we can efficiently 404 // update this when we remove instructions. 405 if (Instruction *Inst = Dep.getInst()) 406 ReverseNonLocalDeps[Inst].insert(QueryInst); 407 } else { 408 409 // If the block *is* completely transparent to the load, we need to check 410 // the predecessors of this block. Add them to our worklist. 411 DirtyBlocks.append(pred_begin(DirtyBB), pred_end(DirtyBB)); 412 } 413 } 414 415 return Cache; 416} 417 418/// removeInstruction - Remove an instruction from the dependence analysis, 419/// updating the dependence of instructions that previously depended on it. 420/// This method attempts to keep the cache coherent using the reverse map. 421void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { 422 // Walk through the Non-local dependencies, removing this one as the value 423 // for any cached queries. 424 NonLocalDepMapType::iterator NLDI = NonLocalDeps.find(RemInst); 425 if (NLDI != NonLocalDeps.end()) { 426 NonLocalDepInfo &BlockMap = NLDI->second.first; 427 for (NonLocalDepInfo::iterator DI = BlockMap.begin(), DE = BlockMap.end(); 428 DI != DE; ++DI) 429 if (Instruction *Inst = DI->second.getInst()) 430 ReverseNonLocalDeps[Inst].erase(RemInst); 431 NonLocalDeps.erase(NLDI); 432 } 433 434 // If we have a cached local dependence query for this instruction, remove it. 435 // 436 LocalDepMapType::iterator LocalDepEntry = LocalDeps.find(RemInst); 437 if (LocalDepEntry != LocalDeps.end()) { 438 // Remove us from DepInst's reverse set now that the local dep info is gone. 439 if (Instruction *Inst = LocalDepEntry->second.getInst()) { 440 SmallPtrSet<Instruction*, 4> &RLD = ReverseLocalDeps[Inst]; 441 RLD.erase(RemInst); 442 if (RLD.empty()) 443 ReverseLocalDeps.erase(Inst); 444 } 445 446 // Remove this local dependency info. 447 LocalDeps.erase(LocalDepEntry); 448 } 449 450 // Loop over all of the things that depend on the instruction we're removing. 451 // 452 SmallVector<std::pair<Instruction*, Instruction*>, 8> ReverseDepsToAdd; 453 454 ReverseDepMapType::iterator ReverseDepIt = ReverseLocalDeps.find(RemInst); 455 if (ReverseDepIt != ReverseLocalDeps.end()) { 456 SmallPtrSet<Instruction*, 4> &ReverseDeps = ReverseDepIt->second; 457 // RemInst can't be the terminator if it has stuff depending on it. 458 assert(!ReverseDeps.empty() && !isa<TerminatorInst>(RemInst) && 459 "Nothing can locally depend on a terminator"); 460 461 // Anything that was locally dependent on RemInst is now going to be 462 // dependent on the instruction after RemInst. It will have the dirty flag 463 // set so it will rescan. This saves having to scan the entire block to get 464 // to this point. 465 Instruction *NewDepInst = next(BasicBlock::iterator(RemInst)); 466 467 for (SmallPtrSet<Instruction*, 4>::iterator I = ReverseDeps.begin(), 468 E = ReverseDeps.end(); I != E; ++I) { 469 Instruction *InstDependingOnRemInst = *I; 470 assert(InstDependingOnRemInst != RemInst && 471 "Already removed our local dep info"); 472 473 LocalDeps[InstDependingOnRemInst] = MemDepResult::getDirty(NewDepInst); 474 475 // Make sure to remember that new things depend on NewDepInst. 476 ReverseDepsToAdd.push_back(std::make_pair(NewDepInst, 477 InstDependingOnRemInst)); 478 } 479 480 ReverseLocalDeps.erase(ReverseDepIt); 481 482 // Add new reverse deps after scanning the set, to avoid invalidating the 483 // 'ReverseDeps' reference. 484 while (!ReverseDepsToAdd.empty()) { 485 ReverseLocalDeps[ReverseDepsToAdd.back().first] 486 .insert(ReverseDepsToAdd.back().second); 487 ReverseDepsToAdd.pop_back(); 488 } 489 } 490 491 ReverseDepIt = ReverseNonLocalDeps.find(RemInst); 492 if (ReverseDepIt != ReverseNonLocalDeps.end()) { 493 SmallPtrSet<Instruction*, 4>& set = ReverseDepIt->second; 494 for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); 495 I != E; ++I) { 496 assert(*I != RemInst && "Already removed NonLocalDep info for RemInst"); 497 498 PerInstNLInfo &INLD = NonLocalDeps[*I]; 499 // The information is now dirty! 500 INLD.second = true; 501 502 for (NonLocalDepInfo::iterator DI = INLD.first.begin(), 503 DE = INLD.first.end(); DI != DE; ++DI) { 504 if (DI->second.getInst() != RemInst) continue; 505 506 // Convert to a dirty entry for the subsequent instruction. 507 Instruction *NextI = 0; 508 if (!RemInst->isTerminator()) { 509 NextI = next(BasicBlock::iterator(RemInst)); 510 ReverseDepsToAdd.push_back(std::make_pair(NextI, *I)); 511 } 512 DI->second = MemDepResult::getDirty(NextI); 513 } 514 } 515 516 ReverseNonLocalDeps.erase(ReverseDepIt); 517 518 // Add new reverse deps after scanning the set, to avoid invalidating 'Set' 519 while (!ReverseDepsToAdd.empty()) { 520 ReverseNonLocalDeps[ReverseDepsToAdd.back().first] 521 .insert(ReverseDepsToAdd.back().second); 522 ReverseDepsToAdd.pop_back(); 523 } 524 } 525 526 assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?"); 527 AA->deleteValue(RemInst); 528 DEBUG(verifyRemoved(RemInst)); 529} 530 531/// verifyRemoved - Verify that the specified instruction does not occur 532/// in our internal data structures. 533void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { 534 for (LocalDepMapType::const_iterator I = LocalDeps.begin(), 535 E = LocalDeps.end(); I != E; ++I) { 536 assert(I->first != D && "Inst occurs in data structures"); 537 assert(I->second.getInst() != D && 538 "Inst occurs in data structures"); 539 } 540 541 for (NonLocalDepMapType::const_iterator I = NonLocalDeps.begin(), 542 E = NonLocalDeps.end(); I != E; ++I) { 543 assert(I->first != D && "Inst occurs in data structures"); 544 const PerInstNLInfo &INLD = I->second; 545 for (NonLocalDepInfo::const_iterator II = INLD.first.begin(), 546 EE = INLD.first.end(); II != EE; ++II) 547 assert(II->second.getInst() != D && "Inst occurs in data structures"); 548 } 549 550 for (ReverseDepMapType::const_iterator I = ReverseLocalDeps.begin(), 551 E = ReverseLocalDeps.end(); I != E; ++I) { 552 assert(I->first != D && "Inst occurs in data structures"); 553 for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), 554 EE = I->second.end(); II != EE; ++II) 555 assert(*II != D && "Inst occurs in data structures"); 556 } 557 558 for (ReverseDepMapType::const_iterator I = ReverseNonLocalDeps.begin(), 559 E = ReverseNonLocalDeps.end(); 560 I != E; ++I) { 561 assert(I->first != D && "Inst occurs in data structures"); 562 for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), 563 EE = I->second.end(); II != EE; ++II) 564 assert(*II != D && "Inst occurs in data structures"); 565 } 566} 567