1 //===- MemoryDependenceAnalysis.cpp - Mem Deps Implementation --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
15 //===----------------------------------------------------------------------===//
17 #define DEBUG_TYPE "memdep"
18 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/IntrinsicInst.h"
21 #include "llvm/Function.h"
22 #include "llvm/LLVMContext.h"
23 #include "llvm/Analysis/AliasAnalysis.h"
24 #include "llvm/Analysis/Dominators.h"
25 #include "llvm/Analysis/InstructionSimplify.h"
26 #include "llvm/Analysis/MemoryBuiltins.h"
27 #include "llvm/Analysis/PHITransAddr.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/STLExtras.h"
30 #include "llvm/Support/PredIteratorCache.h"
31 #include "llvm/Support/Debug.h"
34 STATISTIC(NumCacheNonLocal, "Number of fully cached non-local responses");
35 STATISTIC(NumCacheDirtyNonLocal, "Number of dirty cached non-local responses");
36 STATISTIC(NumUncacheNonLocal, "Number of uncached non-local responses");
38 STATISTIC(NumCacheNonLocalPtr,
39 "Number of fully cached non-local ptr responses");
40 STATISTIC(NumCacheDirtyNonLocalPtr,
41 "Number of cached, but dirty, non-local ptr responses");
42 STATISTIC(NumUncacheNonLocalPtr,
43 "Number of uncached non-local ptr responses");
44 STATISTIC(NumCacheCompleteNonLocalPtr,
45 "Number of block queries that were completely cached");
47 char MemoryDependenceAnalysis::ID = 0;
49 // Register this pass...
50 INITIALIZE_PASS_BEGIN(MemoryDependenceAnalysis, "memdep",
51 "Memory Dependence Analysis", false, true)
52 INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
53 INITIALIZE_PASS_END(MemoryDependenceAnalysis, "memdep",
54 "Memory Dependence Analysis", false, true)
56 MemoryDependenceAnalysis::MemoryDependenceAnalysis()
57 : FunctionPass(ID), PredCache(0) {
59 MemoryDependenceAnalysis::~MemoryDependenceAnalysis() {
62 /// Clean up memory in between runs
63 void MemoryDependenceAnalysis::releaseMemory() {
66 NonLocalPointerDeps.clear();
67 ReverseLocalDeps.clear();
68 ReverseNonLocalDeps.clear();
69 ReverseNonLocalPtrDeps.clear();
75 /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis.
77 void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
79 AU.addRequiredTransitive<AliasAnalysis>();
82 bool MemoryDependenceAnalysis::runOnFunction(Function &) {
83 AA = &getAnalysis<AliasAnalysis>();
85 PredCache.reset(new PredIteratorCache());
89 /// RemoveFromReverseMap - This is a helper function that removes Val from
90 /// 'Inst's set in ReverseMap. If the set becomes empty, remove Inst's entry.
91 template <typename KeyTy>
92 static void RemoveFromReverseMap(DenseMap<Instruction*,
93 SmallPtrSet<KeyTy, 4> > &ReverseMap,
94 Instruction *Inst, KeyTy Val) {
95 typename DenseMap<Instruction*, SmallPtrSet<KeyTy, 4> >::iterator
96 InstIt = ReverseMap.find(Inst);
97 assert(InstIt != ReverseMap.end() && "Reverse map out of sync?");
98 bool Found = InstIt->second.erase(Val);
99 assert(Found && "Invalid reverse map!"); Found=Found;
100 if (InstIt->second.empty())
101 ReverseMap.erase(InstIt);
105 /// getCallSiteDependencyFrom - Private helper for finding the local
106 /// dependencies of a call site.
107 MemDepResult MemoryDependenceAnalysis::
108 getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall,
109 BasicBlock::iterator ScanIt, BasicBlock *BB) {
110 // Walk backwards through the block, looking for dependencies
111 while (ScanIt != BB->begin()) {
112 Instruction *Inst = --ScanIt;
114 // If this inst is a memory op, get the pointer it accessed
115 AliasAnalysis::Location Loc;
116 if (StoreInst *S = dyn_cast<StoreInst>(Inst)) {
117 Loc = AliasAnalysis::Location(S->getPointerOperand(),
118 AA->getTypeStoreSize(S->getValueOperand()
120 S->getMetadata(LLVMContext::MD_tbaa));
121 } else if (VAArgInst *V = dyn_cast<VAArgInst>(Inst)) {
122 Loc = AliasAnalysis::Location(V->getPointerOperand(),
123 AA->getTypeStoreSize(V->getType()),
124 V->getMetadata(LLVMContext::MD_tbaa));
125 } else if (const CallInst *CI = isFreeCall(Inst)) {
126 // calls to free() erase the entire structure
127 Loc = AliasAnalysis::Location(CI->getArgOperand(0));
128 } else if (CallSite InstCS = cast<Value>(Inst)) {
129 // Debug intrinsics don't cause dependences.
130 if (isa<DbgInfoIntrinsic>(Inst)) continue;
131 // If these two calls do not interfere, look past it.
132 switch (AA->getModRefInfo(CS, InstCS)) {
133 case AliasAnalysis::NoModRef:
134 // If the two calls are the same, return InstCS as a Def, so that
135 // CS can be found redundant and eliminated.
136 if (isReadOnlyCall && InstCS.onlyReadsMemory() &&
137 CS.getInstruction()->isIdenticalToWhenDefined(Inst))
138 return MemDepResult::getDef(Inst);
140 // Otherwise if the two calls don't interact (e.g. InstCS is readnone)
144 return MemDepResult::getClobber(Inst);
147 // Non-memory instruction.
151 if (AA->getModRefInfo(CS, Loc) != AliasAnalysis::NoModRef)
152 return MemDepResult::getClobber(Inst);
155 // No dependence found. If this is the entry block of the function, it is a
156 // clobber, otherwise it is non-local.
157 if (BB != &BB->getParent()->getEntryBlock())
158 return MemDepResult::getNonLocal();
159 return MemDepResult::getClobber(ScanIt);
162 /// getPointerDependencyFrom - Return the instruction on which a memory
163 /// location depends. If isLoad is true, this routine ignore may-aliases with
164 /// read-only operations.
165 MemDepResult MemoryDependenceAnalysis::
166 getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad,
167 BasicBlock::iterator ScanIt, BasicBlock *BB) {
169 Value *InvariantTag = 0;
171 // Walk backwards through the basic block, looking for dependencies.
172 while (ScanIt != BB->begin()) {
173 Instruction *Inst = --ScanIt;
175 // If we're in an invariant region, no dependencies can be found before
176 // we pass an invariant-begin marker.
177 if (InvariantTag == Inst) {
182 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
183 // Debug intrinsics don't (and can't) cause dependences.
184 if (isa<DbgInfoIntrinsic>(II)) continue;
186 // If we pass an invariant-end marker, then we've just entered an
187 // invariant region and can start ignoring dependencies.
188 if (II->getIntrinsicID() == Intrinsic::invariant_end) {
189 // FIXME: This only considers queries directly on the invariant-tagged
190 // pointer, not on query pointers that are indexed off of them. It'd
191 // be nice to handle that at some point.
192 AliasAnalysis::AliasResult R =
193 AA->alias(AliasAnalysis::Location(II->getArgOperand(2)), MemLoc);
194 if (R == AliasAnalysis::MustAlias)
195 InvariantTag = II->getArgOperand(0);
200 // If we reach a lifetime begin or end marker, then the query ends here
201 // because the value is undefined.
202 if (II->getIntrinsicID() == Intrinsic::lifetime_start) {
203 // FIXME: This only considers queries directly on the invariant-tagged
204 // pointer, not on query pointers that are indexed off of them. It'd
205 // be nice to handle that at some point.
206 AliasAnalysis::AliasResult R =
207 AA->alias(AliasAnalysis::Location(II->getArgOperand(1)), MemLoc);
208 if (R == AliasAnalysis::MustAlias)
209 return MemDepResult::getDef(II);
214 // If we're querying on a load and we're in an invariant region, we're done
215 // at this point. Nothing a load depends on can live in an invariant region.
217 // FIXME: this will prevent us from returning load/load must-aliases, so GVN
218 // won't remove redundant loads.
219 if (isLoad && InvariantTag) continue;
221 // Values depend on loads if the pointers are must aliased. This means that
222 // a load depends on another must aliased load from the same value.
223 if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
224 Value *Pointer = LI->getPointerOperand();
225 uint64_t PointerSize = AA->getTypeStoreSize(LI->getType());
226 MDNode *TBAATag = LI->getMetadata(LLVMContext::MD_tbaa);
228 // If we found a pointer, check if it could be the same as our pointer.
229 AliasAnalysis::AliasResult R =
230 AA->alias(AliasAnalysis::Location(Pointer, PointerSize, TBAATag),
232 if (R == AliasAnalysis::NoAlias)
235 // May-alias loads don't depend on each other without a dependence.
236 if (isLoad && R == AliasAnalysis::MayAlias)
238 // Stores depend on may and must aliased loads, loads depend on must-alias
240 return MemDepResult::getDef(Inst);
243 if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
244 // There can't be stores to the value we care about inside an
246 if (InvariantTag) continue;
248 // If alias analysis can tell that this store is guaranteed to not modify
249 // the query pointer, ignore it. Use getModRefInfo to handle cases where
250 // the query pointer points to constant memory etc.
251 if (AA->getModRefInfo(SI, MemLoc) == AliasAnalysis::NoModRef)
254 // Ok, this store might clobber the query pointer. Check to see if it is
255 // a must alias: in this case, we want to return this as a def.
256 Value *Pointer = SI->getPointerOperand();
257 uint64_t PointerSize = AA->getTypeStoreSize(SI->getOperand(0)->getType());
258 MDNode *TBAATag = SI->getMetadata(LLVMContext::MD_tbaa);
260 // If we found a pointer, check if it could be the same as our pointer.
261 AliasAnalysis::AliasResult R =
262 AA->alias(AliasAnalysis::Location(Pointer, PointerSize, TBAATag),
265 if (R == AliasAnalysis::NoAlias)
267 if (R == AliasAnalysis::MayAlias)
268 return MemDepResult::getClobber(Inst);
269 return MemDepResult::getDef(Inst);
272 // If this is an allocation, and if we know that the accessed pointer is to
273 // the allocation, return Def. This means that there is no dependence and
274 // the access can be optimized based on that. For example, a load could
276 // Note: Only determine this to be a malloc if Inst is the malloc call, not
277 // a subsequent bitcast of the malloc call result. There can be stores to
278 // the malloced memory between the malloc call and its bitcast uses, and we
279 // need to continue scanning until the malloc call.
280 if (isa<AllocaInst>(Inst) ||
281 (isa<CallInst>(Inst) && extractMallocCall(Inst))) {
282 const Value *AccessPtr = MemLoc.Ptr->getUnderlyingObject();
284 if (AccessPtr == Inst ||
285 AA->alias(Inst, 1, AccessPtr, 1) == AliasAnalysis::MustAlias)
286 return MemDepResult::getDef(Inst);
290 // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer.
291 switch (AA->getModRefInfo(Inst, MemLoc)) {
292 case AliasAnalysis::NoModRef:
293 // If the call has no effect on the queried pointer, just ignore it.
295 case AliasAnalysis::Mod:
296 // If we're in an invariant region, we can ignore calls that ONLY
297 // modify the pointer.
298 if (InvariantTag) continue;
299 return MemDepResult::getClobber(Inst);
300 case AliasAnalysis::Ref:
301 // If the call is known to never store to the pointer, and if this is a
302 // load query, we can safely ignore it (scan past it).
306 // Otherwise, there is a potential dependence. Return a clobber.
307 return MemDepResult::getClobber(Inst);
311 // No dependence found. If this is the entry block of the function, it is a
312 // clobber, otherwise it is non-local.
313 if (BB != &BB->getParent()->getEntryBlock())
314 return MemDepResult::getNonLocal();
315 return MemDepResult::getClobber(ScanIt);
318 /// getDependency - Return the instruction on which a memory operation
320 MemDepResult MemoryDependenceAnalysis::getDependency(Instruction *QueryInst) {
321 Instruction *ScanPos = QueryInst;
323 // Check for a cached result
324 MemDepResult &LocalCache = LocalDeps[QueryInst];
326 // If the cached entry is non-dirty, just return it. Note that this depends
327 // on MemDepResult's default constructing to 'dirty'.
328 if (!LocalCache.isDirty())
331 // Otherwise, if we have a dirty entry, we know we can start the scan at that
332 // instruction, which may save us some work.
333 if (Instruction *Inst = LocalCache.getInst()) {
336 RemoveFromReverseMap(ReverseLocalDeps, Inst, QueryInst);
339 BasicBlock *QueryParent = QueryInst->getParent();
341 AliasAnalysis::Location MemLoc;
344 if (BasicBlock::iterator(QueryInst) == QueryParent->begin()) {
345 // No dependence found. If this is the entry block of the function, it is a
346 // clobber, otherwise it is non-local.
347 if (QueryParent != &QueryParent->getParent()->getEntryBlock())
348 LocalCache = MemDepResult::getNonLocal();
350 LocalCache = MemDepResult::getClobber(QueryInst);
351 } else if (StoreInst *SI = dyn_cast<StoreInst>(QueryInst)) {
352 // If this is a volatile store, don't mess around with it. Just return the
353 // previous instruction as a clobber.
354 if (SI->isVolatile())
355 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos));
357 MemLoc = AliasAnalysis::Location(SI->getPointerOperand(),
358 AA->getTypeStoreSize(SI->getOperand(0)
360 SI->getMetadata(LLVMContext::MD_tbaa));
361 } else if (LoadInst *LI = dyn_cast<LoadInst>(QueryInst)) {
362 // If this is a volatile load, don't mess around with it. Just return the
363 // previous instruction as a clobber.
364 if (LI->isVolatile())
365 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos));
367 MemLoc = AliasAnalysis::Location(LI->getPointerOperand(),
368 AA->getTypeStoreSize(LI->getType()),
369 LI->getMetadata(LLVMContext::MD_tbaa));
370 } else if (const CallInst *CI = isFreeCall(QueryInst)) {
371 // calls to free() erase the entire structure, not just a field.
372 MemLoc = AliasAnalysis::Location(CI->getArgOperand(0));
373 } else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)) {
374 int IntrinsicID = 0; // Intrinsic IDs start at 1.
375 IntrinsicInst *II = dyn_cast<IntrinsicInst>(QueryInst);
377 IntrinsicID = II->getIntrinsicID();
379 switch (IntrinsicID) {
380 case Intrinsic::lifetime_start:
381 case Intrinsic::lifetime_end:
382 case Intrinsic::invariant_start:
383 MemLoc = AliasAnalysis::Location(II->getArgOperand(1),
384 cast<ConstantInt>(II->getArgOperand(0))
386 II->getMetadata(LLVMContext::MD_tbaa));
388 case Intrinsic::invariant_end:
389 MemLoc = AliasAnalysis::Location(II->getArgOperand(2),
390 cast<ConstantInt>(II->getArgOperand(1))
392 II->getMetadata(LLVMContext::MD_tbaa));
395 CallSite QueryCS(QueryInst);
396 bool isReadOnly = AA->onlyReadsMemory(QueryCS);
397 LocalCache = getCallSiteDependencyFrom(QueryCS, isReadOnly, ScanPos,
402 // Non-memory instruction.
403 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos));
406 // If we need to do a pointer scan, make it happen.
408 bool isLoad = !QueryInst->mayWriteToMemory();
409 if (IntrinsicInst *II = dyn_cast<MemoryUseIntrinsic>(QueryInst)) {
410 isLoad |= II->getIntrinsicID() == Intrinsic::lifetime_end;
412 LocalCache = getPointerDependencyFrom(MemLoc, isLoad, ScanPos,
416 // Remember the result!
417 if (Instruction *I = LocalCache.getInst())
418 ReverseLocalDeps[I].insert(QueryInst);
424 /// AssertSorted - This method is used when -debug is specified to verify that
425 /// cache arrays are properly kept sorted.
426 static void AssertSorted(MemoryDependenceAnalysis::NonLocalDepInfo &Cache,
428 if (Count == -1) Count = Cache.size();
429 if (Count == 0) return;
431 for (unsigned i = 1; i != unsigned(Count); ++i)
432 assert(!(Cache[i] < Cache[i-1]) && "Cache isn't sorted!");
436 /// getNonLocalCallDependency - Perform a full dependency query for the
437 /// specified call, returning the set of blocks that the value is
438 /// potentially live across. The returned set of results will include a
439 /// "NonLocal" result for all blocks where the value is live across.
441 /// This method assumes the instruction returns a "NonLocal" dependency
442 /// within its own block.
444 /// This returns a reference to an internal data structure that may be
445 /// invalidated on the next non-local query or when an instruction is
446 /// removed. Clients must copy this data if they want it around longer than
448 const MemoryDependenceAnalysis::NonLocalDepInfo &
449 MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) {
450 assert(getDependency(QueryCS.getInstruction()).isNonLocal() &&
451 "getNonLocalCallDependency should only be used on calls with non-local deps!");
452 PerInstNLInfo &CacheP = NonLocalDeps[QueryCS.getInstruction()];
453 NonLocalDepInfo &Cache = CacheP.first;
455 /// DirtyBlocks - This is the set of blocks that need to be recomputed. In
456 /// the cached case, this can happen due to instructions being deleted etc. In
457 /// the uncached case, this starts out as the set of predecessors we care
459 SmallVector<BasicBlock*, 32> DirtyBlocks;
461 if (!Cache.empty()) {
462 // Okay, we have a cache entry. If we know it is not dirty, just return it
463 // with no computation.
464 if (!CacheP.second) {
469 // If we already have a partially computed set of results, scan them to
470 // determine what is dirty, seeding our initial DirtyBlocks worklist.
471 for (NonLocalDepInfo::iterator I = Cache.begin(), E = Cache.end();
473 if (I->getResult().isDirty())
474 DirtyBlocks.push_back(I->getBB());
476 // Sort the cache so that we can do fast binary search lookups below.
477 std::sort(Cache.begin(), Cache.end());
479 ++NumCacheDirtyNonLocal;
480 //cerr << "CACHED CASE: " << DirtyBlocks.size() << " dirty: "
481 // << Cache.size() << " cached: " << *QueryInst;
483 // Seed DirtyBlocks with each of the preds of QueryInst's block.
484 BasicBlock *QueryBB = QueryCS.getInstruction()->getParent();
485 for (BasicBlock **PI = PredCache->GetPreds(QueryBB); *PI; ++PI)
486 DirtyBlocks.push_back(*PI);
487 ++NumUncacheNonLocal;
490 // isReadonlyCall - If this is a read-only call, we can be more aggressive.
491 bool isReadonlyCall = AA->onlyReadsMemory(QueryCS);
493 SmallPtrSet<BasicBlock*, 64> Visited;
495 unsigned NumSortedEntries = Cache.size();
496 DEBUG(AssertSorted(Cache));
498 // Iterate while we still have blocks to update.
499 while (!DirtyBlocks.empty()) {
500 BasicBlock *DirtyBB = DirtyBlocks.back();
501 DirtyBlocks.pop_back();
503 // Already processed this block?
504 if (!Visited.insert(DirtyBB))
507 // Do a binary search to see if we already have an entry for this block in
508 // the cache set. If so, find it.
509 DEBUG(AssertSorted(Cache, NumSortedEntries));
510 NonLocalDepInfo::iterator Entry =
511 std::upper_bound(Cache.begin(), Cache.begin()+NumSortedEntries,
512 NonLocalDepEntry(DirtyBB));
513 if (Entry != Cache.begin() && prior(Entry)->getBB() == DirtyBB)
516 NonLocalDepEntry *ExistingResult = 0;
517 if (Entry != Cache.begin()+NumSortedEntries &&
518 Entry->getBB() == DirtyBB) {
519 // If we already have an entry, and if it isn't already dirty, the block
521 if (!Entry->getResult().isDirty())
524 // Otherwise, remember this slot so we can update the value.
525 ExistingResult = &*Entry;
528 // If the dirty entry has a pointer, start scanning from it so we don't have
529 // to rescan the entire block.
530 BasicBlock::iterator ScanPos = DirtyBB->end();
531 if (ExistingResult) {
532 if (Instruction *Inst = ExistingResult->getResult().getInst()) {
534 // We're removing QueryInst's use of Inst.
535 RemoveFromReverseMap(ReverseNonLocalDeps, Inst,
536 QueryCS.getInstruction());
540 // Find out if this block has a local dependency for QueryInst.
543 if (ScanPos != DirtyBB->begin()) {
544 Dep = getCallSiteDependencyFrom(QueryCS, isReadonlyCall,ScanPos, DirtyBB);
545 } else if (DirtyBB != &DirtyBB->getParent()->getEntryBlock()) {
546 // No dependence found. If this is the entry block of the function, it is
547 // a clobber, otherwise it is non-local.
548 Dep = MemDepResult::getNonLocal();
550 Dep = MemDepResult::getClobber(ScanPos);
553 // If we had a dirty entry for the block, update it. Otherwise, just add
556 ExistingResult->setResult(Dep);
558 Cache.push_back(NonLocalDepEntry(DirtyBB, Dep));
560 // If the block has a dependency (i.e. it isn't completely transparent to
561 // the value), remember the association!
562 if (!Dep.isNonLocal()) {
563 // Keep the ReverseNonLocalDeps map up to date so we can efficiently
564 // update this when we remove instructions.
565 if (Instruction *Inst = Dep.getInst())
566 ReverseNonLocalDeps[Inst].insert(QueryCS.getInstruction());
569 // If the block *is* completely transparent to the load, we need to check
570 // the predecessors of this block. Add them to our worklist.
571 for (BasicBlock **PI = PredCache->GetPreds(DirtyBB); *PI; ++PI)
572 DirtyBlocks.push_back(*PI);
579 /// getNonLocalPointerDependency - Perform a full dependency query for an
580 /// access to the specified (non-volatile) memory location, returning the
581 /// set of instructions that either define or clobber the value.
583 /// This method assumes the pointer has a "NonLocal" dependency within its
586 void MemoryDependenceAnalysis::
587 getNonLocalPointerDependency(const AliasAnalysis::Location &Loc, bool isLoad,
589 SmallVectorImpl<NonLocalDepResult> &Result) {
590 assert(Loc.Ptr->getType()->isPointerTy() &&
591 "Can't get pointer deps of a non-pointer!");
594 PHITransAddr Address(const_cast<Value *>(Loc.Ptr), TD);
596 // This is the set of blocks we've inspected, and the pointer we consider in
597 // each block. Because of critical edges, we currently bail out if querying
598 // a block with multiple different pointers. This can happen during PHI
600 DenseMap<BasicBlock*, Value*> Visited;
601 if (!getNonLocalPointerDepFromBB(Address, Loc, isLoad, FromBB,
602 Result, Visited, true))
605 Result.push_back(NonLocalDepResult(FromBB,
606 MemDepResult::getClobber(FromBB->begin()),
607 const_cast<Value *>(Loc.Ptr)));
610 /// GetNonLocalInfoForBlock - Compute the memdep value for BB with
611 /// Pointer/PointeeSize using either cached information in Cache or by doing a
612 /// lookup (which may use dirty cache info if available). If we do a lookup,
613 /// add the result to the cache.
614 MemDepResult MemoryDependenceAnalysis::
615 GetNonLocalInfoForBlock(const AliasAnalysis::Location &Loc,
616 bool isLoad, BasicBlock *BB,
617 NonLocalDepInfo *Cache, unsigned NumSortedEntries) {
619 // Do a binary search to see if we already have an entry for this block in
620 // the cache set. If so, find it.
621 NonLocalDepInfo::iterator Entry =
622 std::upper_bound(Cache->begin(), Cache->begin()+NumSortedEntries,
623 NonLocalDepEntry(BB));
624 if (Entry != Cache->begin() && (Entry-1)->getBB() == BB)
627 NonLocalDepEntry *ExistingResult = 0;
628 if (Entry != Cache->begin()+NumSortedEntries && Entry->getBB() == BB)
629 ExistingResult = &*Entry;
631 // If we have a cached entry, and it is non-dirty, use it as the value for
633 if (ExistingResult && !ExistingResult->getResult().isDirty()) {
634 ++NumCacheNonLocalPtr;
635 return ExistingResult->getResult();
638 // Otherwise, we have to scan for the value. If we have a dirty cache
639 // entry, start scanning from its position, otherwise we scan from the end
641 BasicBlock::iterator ScanPos = BB->end();
642 if (ExistingResult && ExistingResult->getResult().getInst()) {
643 assert(ExistingResult->getResult().getInst()->getParent() == BB &&
644 "Instruction invalidated?");
645 ++NumCacheDirtyNonLocalPtr;
646 ScanPos = ExistingResult->getResult().getInst();
648 // Eliminating the dirty entry from 'Cache', so update the reverse info.
649 ValueIsLoadPair CacheKey(Loc.Ptr, isLoad);
650 RemoveFromReverseMap(ReverseNonLocalPtrDeps, ScanPos, CacheKey);
652 ++NumUncacheNonLocalPtr;
655 // Scan the block for the dependency.
656 MemDepResult Dep = getPointerDependencyFrom(Loc, isLoad, ScanPos, BB);
658 // If we had a dirty entry for the block, update it. Otherwise, just add
661 ExistingResult->setResult(Dep);
663 Cache->push_back(NonLocalDepEntry(BB, Dep));
665 // If the block has a dependency (i.e. it isn't completely transparent to
666 // the value), remember the reverse association because we just added it
668 if (Dep.isNonLocal())
671 // Keep the ReverseNonLocalPtrDeps map up to date so we can efficiently
672 // update MemDep when we remove instructions.
673 Instruction *Inst = Dep.getInst();
674 assert(Inst && "Didn't depend on anything?");
675 ValueIsLoadPair CacheKey(Loc.Ptr, isLoad);
676 ReverseNonLocalPtrDeps[Inst].insert(CacheKey);
680 /// SortNonLocalDepInfoCache - Sort the a NonLocalDepInfo cache, given a certain
681 /// number of elements in the array that are already properly ordered. This is
682 /// optimized for the case when only a few entries are added.
684 SortNonLocalDepInfoCache(MemoryDependenceAnalysis::NonLocalDepInfo &Cache,
685 unsigned NumSortedEntries) {
686 switch (Cache.size() - NumSortedEntries) {
688 // done, no new entries.
691 // Two new entries, insert the last one into place.
692 NonLocalDepEntry Val = Cache.back();
694 MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry =
695 std::upper_bound(Cache.begin(), Cache.end()-1, Val);
696 Cache.insert(Entry, Val);
700 // One new entry, Just insert the new value at the appropriate position.
701 if (Cache.size() != 1) {
702 NonLocalDepEntry Val = Cache.back();
704 MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry =
705 std::upper_bound(Cache.begin(), Cache.end(), Val);
706 Cache.insert(Entry, Val);
710 // Added many values, do a full scale sort.
711 std::sort(Cache.begin(), Cache.end());
716 /// getNonLocalPointerDepFromBB - Perform a dependency query based on
717 /// pointer/pointeesize starting at the end of StartBB. Add any clobber/def
718 /// results to the results vector and keep track of which blocks are visited in
721 /// This has special behavior for the first block queries (when SkipFirstBlock
722 /// is true). In this special case, it ignores the contents of the specified
723 /// block and starts returning dependence info for its predecessors.
725 /// This function returns false on success, or true to indicate that it could
726 /// not compute dependence information for some reason. This should be treated
727 /// as a clobber dependence on the first instruction in the predecessor block.
728 bool MemoryDependenceAnalysis::
729 getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
730 const AliasAnalysis::Location &Loc,
731 bool isLoad, BasicBlock *StartBB,
732 SmallVectorImpl<NonLocalDepResult> &Result,
733 DenseMap<BasicBlock*, Value*> &Visited,
734 bool SkipFirstBlock) {
736 // Look up the cached info for Pointer.
737 ValueIsLoadPair CacheKey(Pointer.getAddr(), isLoad);
738 NonLocalPointerInfo *CacheInfo = &NonLocalPointerDeps[CacheKey];
740 // If this query's TBAATag is inconsistent with the cached one, discard the
741 // tag and restart the query.
742 if (CacheInfo->TBAATag != Loc.TBAATag) {
743 CacheInfo->TBAATag = 0;
744 NonLocalPointerDeps.erase(CacheKey);
745 return getNonLocalPointerDepFromBB(Pointer, Loc.getWithoutTBAATag(),
746 isLoad, StartBB, Result, Visited,
750 NonLocalDepInfo *Cache = &CacheInfo->NonLocalDeps;
752 // If we have valid cached information for exactly the block we are
753 // investigating, just return it with no recomputation.
754 if (CacheInfo->Pair == BBSkipFirstBlockPair(StartBB, SkipFirstBlock)) {
755 // We have a fully cached result for this query then we can just return the
756 // cached results and populate the visited set. However, we have to verify
757 // that we don't already have conflicting results for these blocks. Check
758 // to ensure that if a block in the results set is in the visited set that
759 // it was for the same pointer query.
760 if (!Visited.empty()) {
761 for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end();
763 DenseMap<BasicBlock*, Value*>::iterator VI = Visited.find(I->getBB());
764 if (VI == Visited.end() || VI->second == Pointer.getAddr())
767 // We have a pointer mismatch in a block. Just return clobber, saying
768 // that something was clobbered in this result. We could also do a
769 // non-fully cached query, but there is little point in doing this.
774 Value *Addr = Pointer.getAddr();
775 for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end();
777 Visited.insert(std::make_pair(I->getBB(), Addr));
778 if (!I->getResult().isNonLocal())
779 Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(), Addr));
781 ++NumCacheCompleteNonLocalPtr;
785 // Otherwise, either this is a new block, a block with an invalid cache
786 // pointer or one that we're about to invalidate by putting more info into it
787 // than its valid cache info. If empty, the result will be valid cache info,
788 // otherwise it isn't.
790 CacheInfo->Pair = BBSkipFirstBlockPair(StartBB, SkipFirstBlock);
792 CacheInfo->Pair = BBSkipFirstBlockPair();
793 CacheInfo->TBAATag = 0;
796 SmallVector<BasicBlock*, 32> Worklist;
797 Worklist.push_back(StartBB);
799 // Keep track of the entries that we know are sorted. Previously cached
800 // entries will all be sorted. The entries we add we only sort on demand (we
801 // don't insert every element into its sorted position). We know that we
802 // won't get any reuse from currently inserted values, because we don't
803 // revisit blocks after we insert info for them.
804 unsigned NumSortedEntries = Cache->size();
805 DEBUG(AssertSorted(*Cache));
807 while (!Worklist.empty()) {
808 BasicBlock *BB = Worklist.pop_back_val();
810 // Skip the first block if we have it.
811 if (!SkipFirstBlock) {
812 // Analyze the dependency of *Pointer in FromBB. See if we already have
814 assert(Visited.count(BB) && "Should check 'visited' before adding to WL");
816 // Get the dependency info for Pointer in BB. If we have cached
817 // information, we will use it, otherwise we compute it.
818 DEBUG(AssertSorted(*Cache, NumSortedEntries));
819 MemDepResult Dep = GetNonLocalInfoForBlock(Loc, isLoad, BB, Cache,
822 // If we got a Def or Clobber, add this to the list of results.
823 if (!Dep.isNonLocal()) {
824 Result.push_back(NonLocalDepResult(BB, Dep, Pointer.getAddr()));
829 // If 'Pointer' is an instruction defined in this block, then we need to do
830 // phi translation to change it into a value live in the predecessor block.
831 // If not, we just add the predecessors to the worklist and scan them with
833 if (!Pointer.NeedsPHITranslationFromBlock(BB)) {
834 SkipFirstBlock = false;
835 for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) {
836 // Verify that we haven't looked at this block yet.
837 std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool>
838 InsertRes = Visited.insert(std::make_pair(*PI, Pointer.getAddr()));
839 if (InsertRes.second) {
840 // First time we've looked at *PI.
841 Worklist.push_back(*PI);
845 // If we have seen this block before, but it was with a different
846 // pointer then we have a phi translation failure and we have to treat
847 // this as a clobber.
848 if (InsertRes.first->second != Pointer.getAddr())
849 goto PredTranslationFailure;
854 // We do need to do phi translation, if we know ahead of time we can't phi
855 // translate this value, don't even try.
856 if (!Pointer.IsPotentiallyPHITranslatable())
857 goto PredTranslationFailure;
859 // We may have added values to the cache list before this PHI translation.
860 // If so, we haven't done anything to ensure that the cache remains sorted.
861 // Sort it now (if needed) so that recursive invocations of
862 // getNonLocalPointerDepFromBB and other routines that could reuse the cache
863 // value will only see properly sorted cache arrays.
864 if (Cache && NumSortedEntries != Cache->size()) {
865 SortNonLocalDepInfoCache(*Cache, NumSortedEntries);
866 NumSortedEntries = Cache->size();
870 for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) {
871 BasicBlock *Pred = *PI;
873 // Get the PHI translated pointer in this predecessor. This can fail if
874 // not translatable, in which case the getAddr() returns null.
875 PHITransAddr PredPointer(Pointer);
876 PredPointer.PHITranslateValue(BB, Pred, 0);
878 Value *PredPtrVal = PredPointer.getAddr();
880 // Check to see if we have already visited this pred block with another
881 // pointer. If so, we can't do this lookup. This failure can occur
882 // with PHI translation when a critical edge exists and the PHI node in
883 // the successor translates to a pointer value different than the
884 // pointer the block was first analyzed with.
885 std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool>
886 InsertRes = Visited.insert(std::make_pair(Pred, PredPtrVal));
888 if (!InsertRes.second) {
889 // If the predecessor was visited with PredPtr, then we already did
890 // the analysis and can ignore it.
891 if (InsertRes.first->second == PredPtrVal)
894 // Otherwise, the block was previously analyzed with a different
895 // pointer. We can't represent the result of this case, so we just
896 // treat this as a phi translation failure.
897 goto PredTranslationFailure;
900 // If PHI translation was unable to find an available pointer in this
901 // predecessor, then we have to assume that the pointer is clobbered in
902 // that predecessor. We can still do PRE of the load, which would insert
903 // a computation of the pointer in this predecessor.
904 if (PredPtrVal == 0) {
905 // Add the entry to the Result list.
906 NonLocalDepResult Entry(Pred,
907 MemDepResult::getClobber(Pred->getTerminator()),
909 Result.push_back(Entry);
911 // Since we had a phi translation failure, the cache for CacheKey won't
912 // include all of the entries that we need to immediately satisfy future
913 // queries. Mark this in NonLocalPointerDeps by setting the
914 // BBSkipFirstBlockPair pointer to null. This requires reuse of the
915 // cached value to do more work but not miss the phi trans failure.
916 NonLocalPointerInfo &NLPI = NonLocalPointerDeps[CacheKey];
917 NLPI.Pair = BBSkipFirstBlockPair();
922 // FIXME: it is entirely possible that PHI translating will end up with
923 // the same value. Consider PHI translating something like:
924 // X = phi [x, bb1], [y, bb2]. PHI translating for bb1 doesn't *need*
925 // to recurse here, pedantically speaking.
927 // If we have a problem phi translating, fall through to the code below
928 // to handle the failure condition.
929 if (getNonLocalPointerDepFromBB(PredPointer,
930 Loc.getWithNewPtr(PredPointer.getAddr()),
933 goto PredTranslationFailure;
936 // Refresh the CacheInfo/Cache pointer so that it isn't invalidated.
937 CacheInfo = &NonLocalPointerDeps[CacheKey];
938 Cache = &CacheInfo->NonLocalDeps;
939 NumSortedEntries = Cache->size();
941 // Since we did phi translation, the "Cache" set won't contain all of the
942 // results for the query. This is ok (we can still use it to accelerate
943 // specific block queries) but we can't do the fastpath "return all
944 // results from the set" Clear out the indicator for this.
945 CacheInfo->Pair = BBSkipFirstBlockPair();
946 CacheInfo->TBAATag = 0;
947 SkipFirstBlock = false;
950 PredTranslationFailure:
953 // Refresh the CacheInfo/Cache pointer if it got invalidated.
954 CacheInfo = &NonLocalPointerDeps[CacheKey];
955 Cache = &CacheInfo->NonLocalDeps;
956 NumSortedEntries = Cache->size();
959 // Since we failed phi translation, the "Cache" set won't contain all of the
960 // results for the query. This is ok (we can still use it to accelerate
961 // specific block queries) but we can't do the fastpath "return all
962 // results from the set". Clear out the indicator for this.
963 CacheInfo->Pair = BBSkipFirstBlockPair();
964 CacheInfo->TBAATag = 0;
966 // If *nothing* works, mark the pointer as being clobbered by the first
967 // instruction in this block.
969 // If this is the magic first block, return this as a clobber of the whole
970 // incoming value. Since we can't phi translate to one of the predecessors,
971 // we have to bail out.
975 for (NonLocalDepInfo::reverse_iterator I = Cache->rbegin(); ; ++I) {
976 assert(I != Cache->rend() && "Didn't find current block??");
977 if (I->getBB() != BB)
980 assert(I->getResult().isNonLocal() &&
981 "Should only be here with transparent block");
982 I->setResult(MemDepResult::getClobber(BB->begin()));
983 ReverseNonLocalPtrDeps[BB->begin()].insert(CacheKey);
984 Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(),
990 // Okay, we're done now. If we added new values to the cache, re-sort it.
991 SortNonLocalDepInfoCache(*Cache, NumSortedEntries);
992 DEBUG(AssertSorted(*Cache));
996 /// RemoveCachedNonLocalPointerDependencies - If P exists in
997 /// CachedNonLocalPointerInfo, remove it.
998 void MemoryDependenceAnalysis::
999 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P) {
1000 CachedNonLocalPointerInfo::iterator It =
1001 NonLocalPointerDeps.find(P);
1002 if (It == NonLocalPointerDeps.end()) return;
1004 // Remove all of the entries in the BB->val map. This involves removing
1005 // instructions from the reverse map.
1006 NonLocalDepInfo &PInfo = It->second.NonLocalDeps;
1008 for (unsigned i = 0, e = PInfo.size(); i != e; ++i) {
1009 Instruction *Target = PInfo[i].getResult().getInst();
1010 if (Target == 0) continue; // Ignore non-local dep results.
1011 assert(Target->getParent() == PInfo[i].getBB());
1013 // Eliminating the dirty entry from 'Cache', so update the reverse info.
1014 RemoveFromReverseMap(ReverseNonLocalPtrDeps, Target, P);
1017 // Remove P from NonLocalPointerDeps (which deletes NonLocalDepInfo).
1018 NonLocalPointerDeps.erase(It);
1022 /// invalidateCachedPointerInfo - This method is used to invalidate cached
1023 /// information about the specified pointer, because it may be too
1024 /// conservative in memdep. This is an optional call that can be used when
1025 /// the client detects an equivalence between the pointer and some other
1026 /// value and replaces the other value with ptr. This can make Ptr available
1027 /// in more places that cached info does not necessarily keep.
1028 void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) {
1029 // If Ptr isn't really a pointer, just ignore it.
1030 if (!Ptr->getType()->isPointerTy()) return;
1031 // Flush store info for the pointer.
1032 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false));
1033 // Flush load info for the pointer.
1034 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true));
1037 /// invalidateCachedPredecessors - Clear the PredIteratorCache info.
1038 /// This needs to be done when the CFG changes, e.g., due to splitting
1040 void MemoryDependenceAnalysis::invalidateCachedPredecessors() {
1044 /// removeInstruction - Remove an instruction from the dependence analysis,
1045 /// updating the dependence of instructions that previously depended on it.
1046 /// This method attempts to keep the cache coherent using the reverse map.
1047 void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) {
1048 // Walk through the Non-local dependencies, removing this one as the value
1049 // for any cached queries.
1050 NonLocalDepMapType::iterator NLDI = NonLocalDeps.find(RemInst);
1051 if (NLDI != NonLocalDeps.end()) {
1052 NonLocalDepInfo &BlockMap = NLDI->second.first;
1053 for (NonLocalDepInfo::iterator DI = BlockMap.begin(), DE = BlockMap.end();
1055 if (Instruction *Inst = DI->getResult().getInst())
1056 RemoveFromReverseMap(ReverseNonLocalDeps, Inst, RemInst);
1057 NonLocalDeps.erase(NLDI);
1060 // If we have a cached local dependence query for this instruction, remove it.
1062 LocalDepMapType::iterator LocalDepEntry = LocalDeps.find(RemInst);
1063 if (LocalDepEntry != LocalDeps.end()) {
1064 // Remove us from DepInst's reverse set now that the local dep info is gone.
1065 if (Instruction *Inst = LocalDepEntry->second.getInst())
1066 RemoveFromReverseMap(ReverseLocalDeps, Inst, RemInst);
1068 // Remove this local dependency info.
1069 LocalDeps.erase(LocalDepEntry);
1072 // If we have any cached pointer dependencies on this instruction, remove
1073 // them. If the instruction has non-pointer type, then it can't be a pointer
1076 // Remove it from both the load info and the store info. The instruction
1077 // can't be in either of these maps if it is non-pointer.
1078 if (RemInst->getType()->isPointerTy()) {
1079 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false));
1080 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true));
1083 // Loop over all of the things that depend on the instruction we're removing.
1085 SmallVector<std::pair<Instruction*, Instruction*>, 8> ReverseDepsToAdd;
1087 // If we find RemInst as a clobber or Def in any of the maps for other values,
1088 // we need to replace its entry with a dirty version of the instruction after
1089 // it. If RemInst is a terminator, we use a null dirty value.
1091 // Using a dirty version of the instruction after RemInst saves having to scan
1092 // the entire block to get to this point.
1093 MemDepResult NewDirtyVal;
1094 if (!RemInst->isTerminator())
1095 NewDirtyVal = MemDepResult::getDirty(++BasicBlock::iterator(RemInst));
1097 ReverseDepMapType::iterator ReverseDepIt = ReverseLocalDeps.find(RemInst);
1098 if (ReverseDepIt != ReverseLocalDeps.end()) {
1099 SmallPtrSet<Instruction*, 4> &ReverseDeps = ReverseDepIt->second;
1100 // RemInst can't be the terminator if it has local stuff depending on it.
1101 assert(!ReverseDeps.empty() && !isa<TerminatorInst>(RemInst) &&
1102 "Nothing can locally depend on a terminator");
1104 for (SmallPtrSet<Instruction*, 4>::iterator I = ReverseDeps.begin(),
1105 E = ReverseDeps.end(); I != E; ++I) {
1106 Instruction *InstDependingOnRemInst = *I;
1107 assert(InstDependingOnRemInst != RemInst &&
1108 "Already removed our local dep info");
1110 LocalDeps[InstDependingOnRemInst] = NewDirtyVal;
1112 // Make sure to remember that new things depend on NewDepInst.
1113 assert(NewDirtyVal.getInst() && "There is no way something else can have "
1114 "a local dep on this if it is a terminator!");
1115 ReverseDepsToAdd.push_back(std::make_pair(NewDirtyVal.getInst(),
1116 InstDependingOnRemInst));
1119 ReverseLocalDeps.erase(ReverseDepIt);
1121 // Add new reverse deps after scanning the set, to avoid invalidating the
1122 // 'ReverseDeps' reference.
1123 while (!ReverseDepsToAdd.empty()) {
1124 ReverseLocalDeps[ReverseDepsToAdd.back().first]
1125 .insert(ReverseDepsToAdd.back().second);
1126 ReverseDepsToAdd.pop_back();
1130 ReverseDepIt = ReverseNonLocalDeps.find(RemInst);
1131 if (ReverseDepIt != ReverseNonLocalDeps.end()) {
1132 SmallPtrSet<Instruction*, 4> &Set = ReverseDepIt->second;
1133 for (SmallPtrSet<Instruction*, 4>::iterator I = Set.begin(), E = Set.end();
1135 assert(*I != RemInst && "Already removed NonLocalDep info for RemInst");
1137 PerInstNLInfo &INLD = NonLocalDeps[*I];
1138 // The information is now dirty!
1141 for (NonLocalDepInfo::iterator DI = INLD.first.begin(),
1142 DE = INLD.first.end(); DI != DE; ++DI) {
1143 if (DI->getResult().getInst() != RemInst) continue;
1145 // Convert to a dirty entry for the subsequent instruction.
1146 DI->setResult(NewDirtyVal);
1148 if (Instruction *NextI = NewDirtyVal.getInst())
1149 ReverseDepsToAdd.push_back(std::make_pair(NextI, *I));
1153 ReverseNonLocalDeps.erase(ReverseDepIt);
1155 // Add new reverse deps after scanning the set, to avoid invalidating 'Set'
1156 while (!ReverseDepsToAdd.empty()) {
1157 ReverseNonLocalDeps[ReverseDepsToAdd.back().first]
1158 .insert(ReverseDepsToAdd.back().second);
1159 ReverseDepsToAdd.pop_back();
1163 // If the instruction is in ReverseNonLocalPtrDeps then it appears as a
1164 // value in the NonLocalPointerDeps info.
1165 ReverseNonLocalPtrDepTy::iterator ReversePtrDepIt =
1166 ReverseNonLocalPtrDeps.find(RemInst);
1167 if (ReversePtrDepIt != ReverseNonLocalPtrDeps.end()) {
1168 SmallPtrSet<ValueIsLoadPair, 4> &Set = ReversePtrDepIt->second;
1169 SmallVector<std::pair<Instruction*, ValueIsLoadPair>,8> ReversePtrDepsToAdd;
1171 for (SmallPtrSet<ValueIsLoadPair, 4>::iterator I = Set.begin(),
1172 E = Set.end(); I != E; ++I) {
1173 ValueIsLoadPair P = *I;
1174 assert(P.getPointer() != RemInst &&
1175 "Already removed NonLocalPointerDeps info for RemInst");
1177 NonLocalDepInfo &NLPDI = NonLocalPointerDeps[P].NonLocalDeps;
1179 // The cache is not valid for any specific block anymore.
1180 NonLocalPointerDeps[P].Pair = BBSkipFirstBlockPair();
1181 NonLocalPointerDeps[P].TBAATag = 0;
1183 // Update any entries for RemInst to use the instruction after it.
1184 for (NonLocalDepInfo::iterator DI = NLPDI.begin(), DE = NLPDI.end();
1186 if (DI->getResult().getInst() != RemInst) continue;
1188 // Convert to a dirty entry for the subsequent instruction.
1189 DI->setResult(NewDirtyVal);
1191 if (Instruction *NewDirtyInst = NewDirtyVal.getInst())
1192 ReversePtrDepsToAdd.push_back(std::make_pair(NewDirtyInst, P));
1195 // Re-sort the NonLocalDepInfo. Changing the dirty entry to its
1196 // subsequent value may invalidate the sortedness.
1197 std::sort(NLPDI.begin(), NLPDI.end());
1200 ReverseNonLocalPtrDeps.erase(ReversePtrDepIt);
1202 while (!ReversePtrDepsToAdd.empty()) {
1203 ReverseNonLocalPtrDeps[ReversePtrDepsToAdd.back().first]
1204 .insert(ReversePtrDepsToAdd.back().second);
1205 ReversePtrDepsToAdd.pop_back();
1210 assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?");
1211 AA->deleteValue(RemInst);
1212 DEBUG(verifyRemoved(RemInst));
1214 /// verifyRemoved - Verify that the specified instruction does not occur
1215 /// in our internal data structures.
1216 void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const {
1217 for (LocalDepMapType::const_iterator I = LocalDeps.begin(),
1218 E = LocalDeps.end(); I != E; ++I) {
1219 assert(I->first != D && "Inst occurs in data structures");
1220 assert(I->second.getInst() != D &&
1221 "Inst occurs in data structures");
1224 for (CachedNonLocalPointerInfo::const_iterator I =NonLocalPointerDeps.begin(),
1225 E = NonLocalPointerDeps.end(); I != E; ++I) {
1226 assert(I->first.getPointer() != D && "Inst occurs in NLPD map key");
1227 const NonLocalDepInfo &Val = I->second.NonLocalDeps;
1228 for (NonLocalDepInfo::const_iterator II = Val.begin(), E = Val.end();
1230 assert(II->getResult().getInst() != D && "Inst occurs as NLPD value");
1233 for (NonLocalDepMapType::const_iterator I = NonLocalDeps.begin(),
1234 E = NonLocalDeps.end(); I != E; ++I) {
1235 assert(I->first != D && "Inst occurs in data structures");
1236 const PerInstNLInfo &INLD = I->second;
1237 for (NonLocalDepInfo::const_iterator II = INLD.first.begin(),
1238 EE = INLD.first.end(); II != EE; ++II)
1239 assert(II->getResult().getInst() != D && "Inst occurs in data structures");
1242 for (ReverseDepMapType::const_iterator I = ReverseLocalDeps.begin(),
1243 E = ReverseLocalDeps.end(); I != E; ++I) {
1244 assert(I->first != D && "Inst occurs in data structures");
1245 for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(),
1246 EE = I->second.end(); II != EE; ++II)
1247 assert(*II != D && "Inst occurs in data structures");
1250 for (ReverseDepMapType::const_iterator I = ReverseNonLocalDeps.begin(),
1251 E = ReverseNonLocalDeps.end();
1253 assert(I->first != D && "Inst occurs in data structures");
1254 for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(),
1255 EE = I->second.end(); II != EE; ++II)
1256 assert(*II != D && "Inst occurs in data structures");
1259 for (ReverseNonLocalPtrDepTy::const_iterator
1260 I = ReverseNonLocalPtrDeps.begin(),
1261 E = ReverseNonLocalPtrDeps.end(); I != E; ++I) {
1262 assert(I->first != D && "Inst occurs in rev NLPD map");
1264 for (SmallPtrSet<ValueIsLoadPair, 4>::const_iterator II = I->second.begin(),
1265 E = I->second.end(); II != E; ++II)
1266 assert(*II != ValueIsLoadPair(D, false) &&
1267 *II != ValueIsLoadPair(D, true) &&
1268 "Inst occurs in ReverseNonLocalPtrDeps map");