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) {
58 initializeMemoryDependenceAnalysisPass(*PassRegistry::getPassRegistry());
60 MemoryDependenceAnalysis::~MemoryDependenceAnalysis() {
63 /// Clean up memory in between runs
64 void MemoryDependenceAnalysis::releaseMemory() {
67 NonLocalPointerDeps.clear();
68 ReverseLocalDeps.clear();
69 ReverseNonLocalDeps.clear();
70 ReverseNonLocalPtrDeps.clear();
76 /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis.
78 void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
80 AU.addRequiredTransitive<AliasAnalysis>();
83 bool MemoryDependenceAnalysis::runOnFunction(Function &) {
84 AA = &getAnalysis<AliasAnalysis>();
86 PredCache.reset(new PredIteratorCache());
90 /// RemoveFromReverseMap - This is a helper function that removes Val from
91 /// 'Inst's set in ReverseMap. If the set becomes empty, remove Inst's entry.
92 template <typename KeyTy>
93 static void RemoveFromReverseMap(DenseMap<Instruction*,
94 SmallPtrSet<KeyTy, 4> > &ReverseMap,
95 Instruction *Inst, KeyTy Val) {
96 typename DenseMap<Instruction*, SmallPtrSet<KeyTy, 4> >::iterator
97 InstIt = ReverseMap.find(Inst);
98 assert(InstIt != ReverseMap.end() && "Reverse map out of sync?");
99 bool Found = InstIt->second.erase(Val);
100 assert(Found && "Invalid reverse map!"); Found=Found;
101 if (InstIt->second.empty())
102 ReverseMap.erase(InstIt);
106 /// getCallSiteDependencyFrom - Private helper for finding the local
107 /// dependencies of a call site.
108 MemDepResult MemoryDependenceAnalysis::
109 getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall,
110 BasicBlock::iterator ScanIt, BasicBlock *BB) {
111 // Walk backwards through the block, looking for dependencies
112 while (ScanIt != BB->begin()) {
113 Instruction *Inst = --ScanIt;
115 // If this inst is a memory op, get the pointer it accessed
116 AliasAnalysis::Location Loc;
117 if (StoreInst *S = dyn_cast<StoreInst>(Inst)) {
118 Loc = AliasAnalysis::Location(S->getPointerOperand(),
119 AA->getTypeStoreSize(S->getValueOperand()
121 S->getMetadata(LLVMContext::MD_tbaa));
122 } else if (VAArgInst *V = dyn_cast<VAArgInst>(Inst)) {
123 Loc = AliasAnalysis::Location(V->getPointerOperand(),
124 AA->getTypeStoreSize(V->getType()),
125 V->getMetadata(LLVMContext::MD_tbaa));
126 } else if (const CallInst *CI = isFreeCall(Inst)) {
127 // calls to free() erase the entire structure
128 Loc = AliasAnalysis::Location(CI->getArgOperand(0));
129 } else if (CallSite InstCS = cast<Value>(Inst)) {
130 // Debug intrinsics don't cause dependences.
131 if (isa<DbgInfoIntrinsic>(Inst)) continue;
132 // If these two calls do not interfere, look past it.
133 switch (AA->getModRefInfo(CS, InstCS)) {
134 case AliasAnalysis::NoModRef:
135 // If the two calls are the same, return InstCS as a Def, so that
136 // CS can be found redundant and eliminated.
137 if (isReadOnlyCall && InstCS.onlyReadsMemory() &&
138 CS.getInstruction()->isIdenticalToWhenDefined(Inst))
139 return MemDepResult::getDef(Inst);
141 // Otherwise if the two calls don't interact (e.g. InstCS is readnone)
145 return MemDepResult::getClobber(Inst);
148 // Non-memory instruction.
152 if (AA->getModRefInfo(CS, Loc) != AliasAnalysis::NoModRef)
153 return MemDepResult::getClobber(Inst);
156 // No dependence found. If this is the entry block of the function, it is a
157 // clobber, otherwise it is non-local.
158 if (BB != &BB->getParent()->getEntryBlock())
159 return MemDepResult::getNonLocal();
160 return MemDepResult::getClobber(ScanIt);
163 /// getPointerDependencyFrom - Return the instruction on which a memory
164 /// location depends. If isLoad is true, this routine ignore may-aliases with
165 /// read-only operations.
166 MemDepResult MemoryDependenceAnalysis::
167 getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad,
168 BasicBlock::iterator ScanIt, BasicBlock *BB) {
170 Value *InvariantTag = 0;
172 // Walk backwards through the basic block, looking for dependencies.
173 while (ScanIt != BB->begin()) {
174 Instruction *Inst = --ScanIt;
176 // If we're in an invariant region, no dependencies can be found before
177 // we pass an invariant-begin marker.
178 if (InvariantTag == Inst) {
183 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
184 // Debug intrinsics don't (and can't) cause dependences.
185 if (isa<DbgInfoIntrinsic>(II)) continue;
187 // If we pass an invariant-end marker, then we've just entered an
188 // invariant region and can start ignoring dependencies.
189 if (II->getIntrinsicID() == Intrinsic::invariant_end) {
190 // FIXME: This only considers queries directly on the invariant-tagged
191 // pointer, not on query pointers that are indexed off of them. It'd
192 // be nice to handle that at some point.
193 AliasAnalysis::AliasResult R =
194 AA->alias(AliasAnalysis::Location(II->getArgOperand(2)), MemLoc);
195 if (R == AliasAnalysis::MustAlias)
196 InvariantTag = II->getArgOperand(0);
201 // If we reach a lifetime begin or end marker, then the query ends here
202 // because the value is undefined.
203 if (II->getIntrinsicID() == Intrinsic::lifetime_start) {
204 // FIXME: This only considers queries directly on the invariant-tagged
205 // pointer, not on query pointers that are indexed off of them. It'd
206 // be nice to handle that at some point.
207 AliasAnalysis::AliasResult R =
208 AA->alias(AliasAnalysis::Location(II->getArgOperand(1)), MemLoc);
209 if (R == AliasAnalysis::MustAlias)
210 return MemDepResult::getDef(II);
215 // If we're querying on a load and we're in an invariant region, we're done
216 // at this point. Nothing a load depends on can live in an invariant region.
218 // FIXME: this will prevent us from returning load/load must-aliases, so GVN
219 // won't remove redundant loads.
220 if (isLoad && InvariantTag) continue;
222 // Values depend on loads if the pointers are must aliased. This means that
223 // a load depends on another must aliased load from the same value.
224 if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
225 Value *Pointer = LI->getPointerOperand();
226 uint64_t PointerSize = AA->getTypeStoreSize(LI->getType());
227 MDNode *TBAATag = LI->getMetadata(LLVMContext::MD_tbaa);
229 // If we found a pointer, check if it could be the same as our pointer.
230 AliasAnalysis::AliasResult R =
231 AA->alias(AliasAnalysis::Location(Pointer, PointerSize, TBAATag),
233 if (R == AliasAnalysis::NoAlias)
236 // May-alias loads don't depend on each other without a dependence.
237 if (isLoad && R == AliasAnalysis::MayAlias)
239 // Stores depend on may and must aliased loads, loads depend on must-alias
241 return MemDepResult::getDef(Inst);
244 if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
245 // There can't be stores to the value we care about inside an
247 if (InvariantTag) continue;
249 // If alias analysis can tell that this store is guaranteed to not modify
250 // the query pointer, ignore it. Use getModRefInfo to handle cases where
251 // the query pointer points to constant memory etc.
252 if (AA->getModRefInfo(SI, MemLoc) == AliasAnalysis::NoModRef)
255 // Ok, this store might clobber the query pointer. Check to see if it is
256 // a must alias: in this case, we want to return this as a def.
257 Value *Pointer = SI->getPointerOperand();
258 uint64_t PointerSize = AA->getTypeStoreSize(SI->getOperand(0)->getType());
259 MDNode *TBAATag = SI->getMetadata(LLVMContext::MD_tbaa);
261 // If we found a pointer, check if it could be the same as our pointer.
262 AliasAnalysis::AliasResult R =
263 AA->alias(AliasAnalysis::Location(Pointer, PointerSize, TBAATag),
266 if (R == AliasAnalysis::NoAlias)
268 if (R == AliasAnalysis::MayAlias)
269 return MemDepResult::getClobber(Inst);
270 return MemDepResult::getDef(Inst);
273 // If this is an allocation, and if we know that the accessed pointer is to
274 // the allocation, return Def. This means that there is no dependence and
275 // the access can be optimized based on that. For example, a load could
277 // Note: Only determine this to be a malloc if Inst is the malloc call, not
278 // a subsequent bitcast of the malloc call result. There can be stores to
279 // the malloced memory between the malloc call and its bitcast uses, and we
280 // need to continue scanning until the malloc call.
281 if (isa<AllocaInst>(Inst) ||
282 (isa<CallInst>(Inst) && extractMallocCall(Inst))) {
283 const Value *AccessPtr = MemLoc.Ptr->getUnderlyingObject();
285 if (AccessPtr == Inst ||
286 AA->alias(Inst, 1, AccessPtr, 1) == AliasAnalysis::MustAlias)
287 return MemDepResult::getDef(Inst);
291 // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer.
292 switch (AA->getModRefInfo(Inst, MemLoc)) {
293 case AliasAnalysis::NoModRef:
294 // If the call has no effect on the queried pointer, just ignore it.
296 case AliasAnalysis::Mod:
297 // If we're in an invariant region, we can ignore calls that ONLY
298 // modify the pointer.
299 if (InvariantTag) continue;
300 return MemDepResult::getClobber(Inst);
301 case AliasAnalysis::Ref:
302 // If the call is known to never store to the pointer, and if this is a
303 // load query, we can safely ignore it (scan past it).
307 // Otherwise, there is a potential dependence. Return a clobber.
308 return MemDepResult::getClobber(Inst);
312 // No dependence found. If this is the entry block of the function, it is a
313 // clobber, otherwise it is non-local.
314 if (BB != &BB->getParent()->getEntryBlock())
315 return MemDepResult::getNonLocal();
316 return MemDepResult::getClobber(ScanIt);
319 /// getDependency - Return the instruction on which a memory operation
321 MemDepResult MemoryDependenceAnalysis::getDependency(Instruction *QueryInst) {
322 Instruction *ScanPos = QueryInst;
324 // Check for a cached result
325 MemDepResult &LocalCache = LocalDeps[QueryInst];
327 // If the cached entry is non-dirty, just return it. Note that this depends
328 // on MemDepResult's default constructing to 'dirty'.
329 if (!LocalCache.isDirty())
332 // Otherwise, if we have a dirty entry, we know we can start the scan at that
333 // instruction, which may save us some work.
334 if (Instruction *Inst = LocalCache.getInst()) {
337 RemoveFromReverseMap(ReverseLocalDeps, Inst, QueryInst);
340 BasicBlock *QueryParent = QueryInst->getParent();
342 AliasAnalysis::Location MemLoc;
345 if (BasicBlock::iterator(QueryInst) == QueryParent->begin()) {
346 // No dependence found. If this is the entry block of the function, it is a
347 // clobber, otherwise it is non-local.
348 if (QueryParent != &QueryParent->getParent()->getEntryBlock())
349 LocalCache = MemDepResult::getNonLocal();
351 LocalCache = MemDepResult::getClobber(QueryInst);
352 } else if (StoreInst *SI = dyn_cast<StoreInst>(QueryInst)) {
353 // If this is a volatile store, don't mess around with it. Just return the
354 // previous instruction as a clobber.
355 if (SI->isVolatile())
356 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos));
358 MemLoc = AliasAnalysis::Location(SI->getPointerOperand(),
359 AA->getTypeStoreSize(SI->getOperand(0)
361 SI->getMetadata(LLVMContext::MD_tbaa));
362 } else if (LoadInst *LI = dyn_cast<LoadInst>(QueryInst)) {
363 // If this is a volatile load, don't mess around with it. Just return the
364 // previous instruction as a clobber.
365 if (LI->isVolatile())
366 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos));
368 MemLoc = AliasAnalysis::Location(LI->getPointerOperand(),
369 AA->getTypeStoreSize(LI->getType()),
370 LI->getMetadata(LLVMContext::MD_tbaa));
371 } else if (const CallInst *CI = isFreeCall(QueryInst)) {
372 // calls to free() erase the entire structure, not just a field.
373 MemLoc = AliasAnalysis::Location(CI->getArgOperand(0));
374 } else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)) {
375 int IntrinsicID = 0; // Intrinsic IDs start at 1.
376 IntrinsicInst *II = dyn_cast<IntrinsicInst>(QueryInst);
378 IntrinsicID = II->getIntrinsicID();
380 switch (IntrinsicID) {
381 case Intrinsic::lifetime_start:
382 case Intrinsic::lifetime_end:
383 case Intrinsic::invariant_start:
384 MemLoc = AliasAnalysis::Location(II->getArgOperand(1),
385 cast<ConstantInt>(II->getArgOperand(0))
387 II->getMetadata(LLVMContext::MD_tbaa));
389 case Intrinsic::invariant_end:
390 MemLoc = AliasAnalysis::Location(II->getArgOperand(2),
391 cast<ConstantInt>(II->getArgOperand(1))
393 II->getMetadata(LLVMContext::MD_tbaa));
396 CallSite QueryCS(QueryInst);
397 bool isReadOnly = AA->onlyReadsMemory(QueryCS);
398 LocalCache = getCallSiteDependencyFrom(QueryCS, isReadOnly, ScanPos,
403 // Non-memory instruction.
404 LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos));
407 // If we need to do a pointer scan, make it happen.
409 bool isLoad = !QueryInst->mayWriteToMemory();
410 if (IntrinsicInst *II = dyn_cast<MemoryUseIntrinsic>(QueryInst)) {
411 isLoad |= II->getIntrinsicID() == Intrinsic::lifetime_end;
413 LocalCache = getPointerDependencyFrom(MemLoc, isLoad, ScanPos,
417 // Remember the result!
418 if (Instruction *I = LocalCache.getInst())
419 ReverseLocalDeps[I].insert(QueryInst);
425 /// AssertSorted - This method is used when -debug is specified to verify that
426 /// cache arrays are properly kept sorted.
427 static void AssertSorted(MemoryDependenceAnalysis::NonLocalDepInfo &Cache,
429 if (Count == -1) Count = Cache.size();
430 if (Count == 0) return;
432 for (unsigned i = 1; i != unsigned(Count); ++i)
433 assert(!(Cache[i] < Cache[i-1]) && "Cache isn't sorted!");
437 /// getNonLocalCallDependency - Perform a full dependency query for the
438 /// specified call, returning the set of blocks that the value is
439 /// potentially live across. The returned set of results will include a
440 /// "NonLocal" result for all blocks where the value is live across.
442 /// This method assumes the instruction returns a "NonLocal" dependency
443 /// within its own block.
445 /// This returns a reference to an internal data structure that may be
446 /// invalidated on the next non-local query or when an instruction is
447 /// removed. Clients must copy this data if they want it around longer than
449 const MemoryDependenceAnalysis::NonLocalDepInfo &
450 MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) {
451 assert(getDependency(QueryCS.getInstruction()).isNonLocal() &&
452 "getNonLocalCallDependency should only be used on calls with non-local deps!");
453 PerInstNLInfo &CacheP = NonLocalDeps[QueryCS.getInstruction()];
454 NonLocalDepInfo &Cache = CacheP.first;
456 /// DirtyBlocks - This is the set of blocks that need to be recomputed. In
457 /// the cached case, this can happen due to instructions being deleted etc. In
458 /// the uncached case, this starts out as the set of predecessors we care
460 SmallVector<BasicBlock*, 32> DirtyBlocks;
462 if (!Cache.empty()) {
463 // Okay, we have a cache entry. If we know it is not dirty, just return it
464 // with no computation.
465 if (!CacheP.second) {
470 // If we already have a partially computed set of results, scan them to
471 // determine what is dirty, seeding our initial DirtyBlocks worklist.
472 for (NonLocalDepInfo::iterator I = Cache.begin(), E = Cache.end();
474 if (I->getResult().isDirty())
475 DirtyBlocks.push_back(I->getBB());
477 // Sort the cache so that we can do fast binary search lookups below.
478 std::sort(Cache.begin(), Cache.end());
480 ++NumCacheDirtyNonLocal;
481 //cerr << "CACHED CASE: " << DirtyBlocks.size() << " dirty: "
482 // << Cache.size() << " cached: " << *QueryInst;
484 // Seed DirtyBlocks with each of the preds of QueryInst's block.
485 BasicBlock *QueryBB = QueryCS.getInstruction()->getParent();
486 for (BasicBlock **PI = PredCache->GetPreds(QueryBB); *PI; ++PI)
487 DirtyBlocks.push_back(*PI);
488 ++NumUncacheNonLocal;
491 // isReadonlyCall - If this is a read-only call, we can be more aggressive.
492 bool isReadonlyCall = AA->onlyReadsMemory(QueryCS);
494 SmallPtrSet<BasicBlock*, 64> Visited;
496 unsigned NumSortedEntries = Cache.size();
497 DEBUG(AssertSorted(Cache));
499 // Iterate while we still have blocks to update.
500 while (!DirtyBlocks.empty()) {
501 BasicBlock *DirtyBB = DirtyBlocks.back();
502 DirtyBlocks.pop_back();
504 // Already processed this block?
505 if (!Visited.insert(DirtyBB))
508 // Do a binary search to see if we already have an entry for this block in
509 // the cache set. If so, find it.
510 DEBUG(AssertSorted(Cache, NumSortedEntries));
511 NonLocalDepInfo::iterator Entry =
512 std::upper_bound(Cache.begin(), Cache.begin()+NumSortedEntries,
513 NonLocalDepEntry(DirtyBB));
514 if (Entry != Cache.begin() && prior(Entry)->getBB() == DirtyBB)
517 NonLocalDepEntry *ExistingResult = 0;
518 if (Entry != Cache.begin()+NumSortedEntries &&
519 Entry->getBB() == DirtyBB) {
520 // If we already have an entry, and if it isn't already dirty, the block
522 if (!Entry->getResult().isDirty())
525 // Otherwise, remember this slot so we can update the value.
526 ExistingResult = &*Entry;
529 // If the dirty entry has a pointer, start scanning from it so we don't have
530 // to rescan the entire block.
531 BasicBlock::iterator ScanPos = DirtyBB->end();
532 if (ExistingResult) {
533 if (Instruction *Inst = ExistingResult->getResult().getInst()) {
535 // We're removing QueryInst's use of Inst.
536 RemoveFromReverseMap(ReverseNonLocalDeps, Inst,
537 QueryCS.getInstruction());
541 // Find out if this block has a local dependency for QueryInst.
544 if (ScanPos != DirtyBB->begin()) {
545 Dep = getCallSiteDependencyFrom(QueryCS, isReadonlyCall,ScanPos, DirtyBB);
546 } else if (DirtyBB != &DirtyBB->getParent()->getEntryBlock()) {
547 // No dependence found. If this is the entry block of the function, it is
548 // a clobber, otherwise it is non-local.
549 Dep = MemDepResult::getNonLocal();
551 Dep = MemDepResult::getClobber(ScanPos);
554 // If we had a dirty entry for the block, update it. Otherwise, just add
557 ExistingResult->setResult(Dep);
559 Cache.push_back(NonLocalDepEntry(DirtyBB, Dep));
561 // If the block has a dependency (i.e. it isn't completely transparent to
562 // the value), remember the association!
563 if (!Dep.isNonLocal()) {
564 // Keep the ReverseNonLocalDeps map up to date so we can efficiently
565 // update this when we remove instructions.
566 if (Instruction *Inst = Dep.getInst())
567 ReverseNonLocalDeps[Inst].insert(QueryCS.getInstruction());
570 // If the block *is* completely transparent to the load, we need to check
571 // the predecessors of this block. Add them to our worklist.
572 for (BasicBlock **PI = PredCache->GetPreds(DirtyBB); *PI; ++PI)
573 DirtyBlocks.push_back(*PI);
580 /// getNonLocalPointerDependency - Perform a full dependency query for an
581 /// access to the specified (non-volatile) memory location, returning the
582 /// set of instructions that either define or clobber the value.
584 /// This method assumes the pointer has a "NonLocal" dependency within its
587 void MemoryDependenceAnalysis::
588 getNonLocalPointerDependency(const AliasAnalysis::Location &Loc, bool isLoad,
590 SmallVectorImpl<NonLocalDepResult> &Result) {
591 assert(Loc.Ptr->getType()->isPointerTy() &&
592 "Can't get pointer deps of a non-pointer!");
595 PHITransAddr Address(const_cast<Value *>(Loc.Ptr), TD);
597 // This is the set of blocks we've inspected, and the pointer we consider in
598 // each block. Because of critical edges, we currently bail out if querying
599 // a block with multiple different pointers. This can happen during PHI
601 DenseMap<BasicBlock*, Value*> Visited;
602 if (!getNonLocalPointerDepFromBB(Address, Loc, isLoad, FromBB,
603 Result, Visited, true))
606 Result.push_back(NonLocalDepResult(FromBB,
607 MemDepResult::getClobber(FromBB->begin()),
608 const_cast<Value *>(Loc.Ptr)));
611 /// GetNonLocalInfoForBlock - Compute the memdep value for BB with
612 /// Pointer/PointeeSize using either cached information in Cache or by doing a
613 /// lookup (which may use dirty cache info if available). If we do a lookup,
614 /// add the result to the cache.
615 MemDepResult MemoryDependenceAnalysis::
616 GetNonLocalInfoForBlock(const AliasAnalysis::Location &Loc,
617 bool isLoad, BasicBlock *BB,
618 NonLocalDepInfo *Cache, unsigned NumSortedEntries) {
620 // Do a binary search to see if we already have an entry for this block in
621 // the cache set. If so, find it.
622 NonLocalDepInfo::iterator Entry =
623 std::upper_bound(Cache->begin(), Cache->begin()+NumSortedEntries,
624 NonLocalDepEntry(BB));
625 if (Entry != Cache->begin() && (Entry-1)->getBB() == BB)
628 NonLocalDepEntry *ExistingResult = 0;
629 if (Entry != Cache->begin()+NumSortedEntries && Entry->getBB() == BB)
630 ExistingResult = &*Entry;
632 // If we have a cached entry, and it is non-dirty, use it as the value for
634 if (ExistingResult && !ExistingResult->getResult().isDirty()) {
635 ++NumCacheNonLocalPtr;
636 return ExistingResult->getResult();
639 // Otherwise, we have to scan for the value. If we have a dirty cache
640 // entry, start scanning from its position, otherwise we scan from the end
642 BasicBlock::iterator ScanPos = BB->end();
643 if (ExistingResult && ExistingResult->getResult().getInst()) {
644 assert(ExistingResult->getResult().getInst()->getParent() == BB &&
645 "Instruction invalidated?");
646 ++NumCacheDirtyNonLocalPtr;
647 ScanPos = ExistingResult->getResult().getInst();
649 // Eliminating the dirty entry from 'Cache', so update the reverse info.
650 ValueIsLoadPair CacheKey(Loc.Ptr, isLoad);
651 RemoveFromReverseMap(ReverseNonLocalPtrDeps, ScanPos, CacheKey);
653 ++NumUncacheNonLocalPtr;
656 // Scan the block for the dependency.
657 MemDepResult Dep = getPointerDependencyFrom(Loc, isLoad, ScanPos, BB);
659 // If we had a dirty entry for the block, update it. Otherwise, just add
662 ExistingResult->setResult(Dep);
664 Cache->push_back(NonLocalDepEntry(BB, Dep));
666 // If the block has a dependency (i.e. it isn't completely transparent to
667 // the value), remember the reverse association because we just added it
669 if (Dep.isNonLocal())
672 // Keep the ReverseNonLocalPtrDeps map up to date so we can efficiently
673 // update MemDep when we remove instructions.
674 Instruction *Inst = Dep.getInst();
675 assert(Inst && "Didn't depend on anything?");
676 ValueIsLoadPair CacheKey(Loc.Ptr, isLoad);
677 ReverseNonLocalPtrDeps[Inst].insert(CacheKey);
681 /// SortNonLocalDepInfoCache - Sort the a NonLocalDepInfo cache, given a certain
682 /// number of elements in the array that are already properly ordered. This is
683 /// optimized for the case when only a few entries are added.
685 SortNonLocalDepInfoCache(MemoryDependenceAnalysis::NonLocalDepInfo &Cache,
686 unsigned NumSortedEntries) {
687 switch (Cache.size() - NumSortedEntries) {
689 // done, no new entries.
692 // Two new entries, insert the last one into place.
693 NonLocalDepEntry Val = Cache.back();
695 MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry =
696 std::upper_bound(Cache.begin(), Cache.end()-1, Val);
697 Cache.insert(Entry, Val);
701 // One new entry, Just insert the new value at the appropriate position.
702 if (Cache.size() != 1) {
703 NonLocalDepEntry Val = Cache.back();
705 MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry =
706 std::upper_bound(Cache.begin(), Cache.end(), Val);
707 Cache.insert(Entry, Val);
711 // Added many values, do a full scale sort.
712 std::sort(Cache.begin(), Cache.end());
717 /// getNonLocalPointerDepFromBB - Perform a dependency query based on
718 /// pointer/pointeesize starting at the end of StartBB. Add any clobber/def
719 /// results to the results vector and keep track of which blocks are visited in
722 /// This has special behavior for the first block queries (when SkipFirstBlock
723 /// is true). In this special case, it ignores the contents of the specified
724 /// block and starts returning dependence info for its predecessors.
726 /// This function returns false on success, or true to indicate that it could
727 /// not compute dependence information for some reason. This should be treated
728 /// as a clobber dependence on the first instruction in the predecessor block.
729 bool MemoryDependenceAnalysis::
730 getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
731 const AliasAnalysis::Location &Loc,
732 bool isLoad, BasicBlock *StartBB,
733 SmallVectorImpl<NonLocalDepResult> &Result,
734 DenseMap<BasicBlock*, Value*> &Visited,
735 bool SkipFirstBlock) {
737 // Look up the cached info for Pointer.
738 ValueIsLoadPair CacheKey(Pointer.getAddr(), isLoad);
739 NonLocalPointerInfo *CacheInfo = &NonLocalPointerDeps[CacheKey];
741 // If this query's TBAATag is inconsistent with the cached one, discard the
742 // tag and restart the query.
743 if (CacheInfo->TBAATag != Loc.TBAATag) {
744 CacheInfo->TBAATag = 0;
745 NonLocalPointerDeps.erase(CacheKey);
746 return getNonLocalPointerDepFromBB(Pointer, Loc.getWithoutTBAATag(),
747 isLoad, StartBB, Result, Visited,
751 NonLocalDepInfo *Cache = &CacheInfo->NonLocalDeps;
753 // If we have valid cached information for exactly the block we are
754 // investigating, just return it with no recomputation.
755 if (CacheInfo->Pair == BBSkipFirstBlockPair(StartBB, SkipFirstBlock)) {
756 // We have a fully cached result for this query then we can just return the
757 // cached results and populate the visited set. However, we have to verify
758 // that we don't already have conflicting results for these blocks. Check
759 // to ensure that if a block in the results set is in the visited set that
760 // it was for the same pointer query.
761 if (!Visited.empty()) {
762 for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end();
764 DenseMap<BasicBlock*, Value*>::iterator VI = Visited.find(I->getBB());
765 if (VI == Visited.end() || VI->second == Pointer.getAddr())
768 // We have a pointer mismatch in a block. Just return clobber, saying
769 // that something was clobbered in this result. We could also do a
770 // non-fully cached query, but there is little point in doing this.
775 Value *Addr = Pointer.getAddr();
776 for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end();
778 Visited.insert(std::make_pair(I->getBB(), Addr));
779 if (!I->getResult().isNonLocal())
780 Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(), Addr));
782 ++NumCacheCompleteNonLocalPtr;
786 // Otherwise, either this is a new block, a block with an invalid cache
787 // pointer or one that we're about to invalidate by putting more info into it
788 // than its valid cache info. If empty, the result will be valid cache info,
789 // otherwise it isn't.
791 CacheInfo->Pair = BBSkipFirstBlockPair(StartBB, SkipFirstBlock);
793 CacheInfo->Pair = BBSkipFirstBlockPair();
794 CacheInfo->TBAATag = 0;
797 SmallVector<BasicBlock*, 32> Worklist;
798 Worklist.push_back(StartBB);
800 // Keep track of the entries that we know are sorted. Previously cached
801 // entries will all be sorted. The entries we add we only sort on demand (we
802 // don't insert every element into its sorted position). We know that we
803 // won't get any reuse from currently inserted values, because we don't
804 // revisit blocks after we insert info for them.
805 unsigned NumSortedEntries = Cache->size();
806 DEBUG(AssertSorted(*Cache));
808 while (!Worklist.empty()) {
809 BasicBlock *BB = Worklist.pop_back_val();
811 // Skip the first block if we have it.
812 if (!SkipFirstBlock) {
813 // Analyze the dependency of *Pointer in FromBB. See if we already have
815 assert(Visited.count(BB) && "Should check 'visited' before adding to WL");
817 // Get the dependency info for Pointer in BB. If we have cached
818 // information, we will use it, otherwise we compute it.
819 DEBUG(AssertSorted(*Cache, NumSortedEntries));
820 MemDepResult Dep = GetNonLocalInfoForBlock(Loc, isLoad, BB, Cache,
823 // If we got a Def or Clobber, add this to the list of results.
824 if (!Dep.isNonLocal()) {
825 Result.push_back(NonLocalDepResult(BB, Dep, Pointer.getAddr()));
830 // If 'Pointer' is an instruction defined in this block, then we need to do
831 // phi translation to change it into a value live in the predecessor block.
832 // If not, we just add the predecessors to the worklist and scan them with
834 if (!Pointer.NeedsPHITranslationFromBlock(BB)) {
835 SkipFirstBlock = false;
836 for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) {
837 // Verify that we haven't looked at this block yet.
838 std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool>
839 InsertRes = Visited.insert(std::make_pair(*PI, Pointer.getAddr()));
840 if (InsertRes.second) {
841 // First time we've looked at *PI.
842 Worklist.push_back(*PI);
846 // If we have seen this block before, but it was with a different
847 // pointer then we have a phi translation failure and we have to treat
848 // this as a clobber.
849 if (InsertRes.first->second != Pointer.getAddr())
850 goto PredTranslationFailure;
855 // We do need to do phi translation, if we know ahead of time we can't phi
856 // translate this value, don't even try.
857 if (!Pointer.IsPotentiallyPHITranslatable())
858 goto PredTranslationFailure;
860 // We may have added values to the cache list before this PHI translation.
861 // If so, we haven't done anything to ensure that the cache remains sorted.
862 // Sort it now (if needed) so that recursive invocations of
863 // getNonLocalPointerDepFromBB and other routines that could reuse the cache
864 // value will only see properly sorted cache arrays.
865 if (Cache && NumSortedEntries != Cache->size()) {
866 SortNonLocalDepInfoCache(*Cache, NumSortedEntries);
867 NumSortedEntries = Cache->size();
871 for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) {
872 BasicBlock *Pred = *PI;
874 // Get the PHI translated pointer in this predecessor. This can fail if
875 // not translatable, in which case the getAddr() returns null.
876 PHITransAddr PredPointer(Pointer);
877 PredPointer.PHITranslateValue(BB, Pred, 0);
879 Value *PredPtrVal = PredPointer.getAddr();
881 // Check to see if we have already visited this pred block with another
882 // pointer. If so, we can't do this lookup. This failure can occur
883 // with PHI translation when a critical edge exists and the PHI node in
884 // the successor translates to a pointer value different than the
885 // pointer the block was first analyzed with.
886 std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool>
887 InsertRes = Visited.insert(std::make_pair(Pred, PredPtrVal));
889 if (!InsertRes.second) {
890 // If the predecessor was visited with PredPtr, then we already did
891 // the analysis and can ignore it.
892 if (InsertRes.first->second == PredPtrVal)
895 // Otherwise, the block was previously analyzed with a different
896 // pointer. We can't represent the result of this case, so we just
897 // treat this as a phi translation failure.
898 goto PredTranslationFailure;
901 // If PHI translation was unable to find an available pointer in this
902 // predecessor, then we have to assume that the pointer is clobbered in
903 // that predecessor. We can still do PRE of the load, which would insert
904 // a computation of the pointer in this predecessor.
905 if (PredPtrVal == 0) {
906 // Add the entry to the Result list.
907 NonLocalDepResult Entry(Pred,
908 MemDepResult::getClobber(Pred->getTerminator()),
910 Result.push_back(Entry);
912 // Since we had a phi translation failure, the cache for CacheKey won't
913 // include all of the entries that we need to immediately satisfy future
914 // queries. Mark this in NonLocalPointerDeps by setting the
915 // BBSkipFirstBlockPair pointer to null. This requires reuse of the
916 // cached value to do more work but not miss the phi trans failure.
917 NonLocalPointerInfo &NLPI = NonLocalPointerDeps[CacheKey];
918 NLPI.Pair = BBSkipFirstBlockPair();
923 // FIXME: it is entirely possible that PHI translating will end up with
924 // the same value. Consider PHI translating something like:
925 // X = phi [x, bb1], [y, bb2]. PHI translating for bb1 doesn't *need*
926 // to recurse here, pedantically speaking.
928 // If we have a problem phi translating, fall through to the code below
929 // to handle the failure condition.
930 if (getNonLocalPointerDepFromBB(PredPointer,
931 Loc.getWithNewPtr(PredPointer.getAddr()),
934 goto PredTranslationFailure;
937 // Refresh the CacheInfo/Cache pointer so that it isn't invalidated.
938 CacheInfo = &NonLocalPointerDeps[CacheKey];
939 Cache = &CacheInfo->NonLocalDeps;
940 NumSortedEntries = Cache->size();
942 // Since we did phi translation, the "Cache" set won't contain all of the
943 // results for the query. This is ok (we can still use it to accelerate
944 // specific block queries) but we can't do the fastpath "return all
945 // results from the set" Clear out the indicator for this.
946 CacheInfo->Pair = BBSkipFirstBlockPair();
947 CacheInfo->TBAATag = 0;
948 SkipFirstBlock = false;
951 PredTranslationFailure:
954 // Refresh the CacheInfo/Cache pointer if it got invalidated.
955 CacheInfo = &NonLocalPointerDeps[CacheKey];
956 Cache = &CacheInfo->NonLocalDeps;
957 NumSortedEntries = Cache->size();
960 // Since we failed phi translation, the "Cache" set won't contain all of the
961 // results for the query. This is ok (we can still use it to accelerate
962 // specific block queries) but we can't do the fastpath "return all
963 // results from the set". Clear out the indicator for this.
964 CacheInfo->Pair = BBSkipFirstBlockPair();
965 CacheInfo->TBAATag = 0;
967 // If *nothing* works, mark the pointer as being clobbered by the first
968 // instruction in this block.
970 // If this is the magic first block, return this as a clobber of the whole
971 // incoming value. Since we can't phi translate to one of the predecessors,
972 // we have to bail out.
976 for (NonLocalDepInfo::reverse_iterator I = Cache->rbegin(); ; ++I) {
977 assert(I != Cache->rend() && "Didn't find current block??");
978 if (I->getBB() != BB)
981 assert(I->getResult().isNonLocal() &&
982 "Should only be here with transparent block");
983 I->setResult(MemDepResult::getClobber(BB->begin()));
984 ReverseNonLocalPtrDeps[BB->begin()].insert(CacheKey);
985 Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(),
991 // Okay, we're done now. If we added new values to the cache, re-sort it.
992 SortNonLocalDepInfoCache(*Cache, NumSortedEntries);
993 DEBUG(AssertSorted(*Cache));
997 /// RemoveCachedNonLocalPointerDependencies - If P exists in
998 /// CachedNonLocalPointerInfo, remove it.
999 void MemoryDependenceAnalysis::
1000 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P) {
1001 CachedNonLocalPointerInfo::iterator It =
1002 NonLocalPointerDeps.find(P);
1003 if (It == NonLocalPointerDeps.end()) return;
1005 // Remove all of the entries in the BB->val map. This involves removing
1006 // instructions from the reverse map.
1007 NonLocalDepInfo &PInfo = It->second.NonLocalDeps;
1009 for (unsigned i = 0, e = PInfo.size(); i != e; ++i) {
1010 Instruction *Target = PInfo[i].getResult().getInst();
1011 if (Target == 0) continue; // Ignore non-local dep results.
1012 assert(Target->getParent() == PInfo[i].getBB());
1014 // Eliminating the dirty entry from 'Cache', so update the reverse info.
1015 RemoveFromReverseMap(ReverseNonLocalPtrDeps, Target, P);
1018 // Remove P from NonLocalPointerDeps (which deletes NonLocalDepInfo).
1019 NonLocalPointerDeps.erase(It);
1023 /// invalidateCachedPointerInfo - This method is used to invalidate cached
1024 /// information about the specified pointer, because it may be too
1025 /// conservative in memdep. This is an optional call that can be used when
1026 /// the client detects an equivalence between the pointer and some other
1027 /// value and replaces the other value with ptr. This can make Ptr available
1028 /// in more places that cached info does not necessarily keep.
1029 void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) {
1030 // If Ptr isn't really a pointer, just ignore it.
1031 if (!Ptr->getType()->isPointerTy()) return;
1032 // Flush store info for the pointer.
1033 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false));
1034 // Flush load info for the pointer.
1035 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true));
1038 /// invalidateCachedPredecessors - Clear the PredIteratorCache info.
1039 /// This needs to be done when the CFG changes, e.g., due to splitting
1041 void MemoryDependenceAnalysis::invalidateCachedPredecessors() {
1045 /// removeInstruction - Remove an instruction from the dependence analysis,
1046 /// updating the dependence of instructions that previously depended on it.
1047 /// This method attempts to keep the cache coherent using the reverse map.
1048 void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) {
1049 // Walk through the Non-local dependencies, removing this one as the value
1050 // for any cached queries.
1051 NonLocalDepMapType::iterator NLDI = NonLocalDeps.find(RemInst);
1052 if (NLDI != NonLocalDeps.end()) {
1053 NonLocalDepInfo &BlockMap = NLDI->second.first;
1054 for (NonLocalDepInfo::iterator DI = BlockMap.begin(), DE = BlockMap.end();
1056 if (Instruction *Inst = DI->getResult().getInst())
1057 RemoveFromReverseMap(ReverseNonLocalDeps, Inst, RemInst);
1058 NonLocalDeps.erase(NLDI);
1061 // If we have a cached local dependence query for this instruction, remove it.
1063 LocalDepMapType::iterator LocalDepEntry = LocalDeps.find(RemInst);
1064 if (LocalDepEntry != LocalDeps.end()) {
1065 // Remove us from DepInst's reverse set now that the local dep info is gone.
1066 if (Instruction *Inst = LocalDepEntry->second.getInst())
1067 RemoveFromReverseMap(ReverseLocalDeps, Inst, RemInst);
1069 // Remove this local dependency info.
1070 LocalDeps.erase(LocalDepEntry);
1073 // If we have any cached pointer dependencies on this instruction, remove
1074 // them. If the instruction has non-pointer type, then it can't be a pointer
1077 // Remove it from both the load info and the store info. The instruction
1078 // can't be in either of these maps if it is non-pointer.
1079 if (RemInst->getType()->isPointerTy()) {
1080 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false));
1081 RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true));
1084 // Loop over all of the things that depend on the instruction we're removing.
1086 SmallVector<std::pair<Instruction*, Instruction*>, 8> ReverseDepsToAdd;
1088 // If we find RemInst as a clobber or Def in any of the maps for other values,
1089 // we need to replace its entry with a dirty version of the instruction after
1090 // it. If RemInst is a terminator, we use a null dirty value.
1092 // Using a dirty version of the instruction after RemInst saves having to scan
1093 // the entire block to get to this point.
1094 MemDepResult NewDirtyVal;
1095 if (!RemInst->isTerminator())
1096 NewDirtyVal = MemDepResult::getDirty(++BasicBlock::iterator(RemInst));
1098 ReverseDepMapType::iterator ReverseDepIt = ReverseLocalDeps.find(RemInst);
1099 if (ReverseDepIt != ReverseLocalDeps.end()) {
1100 SmallPtrSet<Instruction*, 4> &ReverseDeps = ReverseDepIt->second;
1101 // RemInst can't be the terminator if it has local stuff depending on it.
1102 assert(!ReverseDeps.empty() && !isa<TerminatorInst>(RemInst) &&
1103 "Nothing can locally depend on a terminator");
1105 for (SmallPtrSet<Instruction*, 4>::iterator I = ReverseDeps.begin(),
1106 E = ReverseDeps.end(); I != E; ++I) {
1107 Instruction *InstDependingOnRemInst = *I;
1108 assert(InstDependingOnRemInst != RemInst &&
1109 "Already removed our local dep info");
1111 LocalDeps[InstDependingOnRemInst] = NewDirtyVal;
1113 // Make sure to remember that new things depend on NewDepInst.
1114 assert(NewDirtyVal.getInst() && "There is no way something else can have "
1115 "a local dep on this if it is a terminator!");
1116 ReverseDepsToAdd.push_back(std::make_pair(NewDirtyVal.getInst(),
1117 InstDependingOnRemInst));
1120 ReverseLocalDeps.erase(ReverseDepIt);
1122 // Add new reverse deps after scanning the set, to avoid invalidating the
1123 // 'ReverseDeps' reference.
1124 while (!ReverseDepsToAdd.empty()) {
1125 ReverseLocalDeps[ReverseDepsToAdd.back().first]
1126 .insert(ReverseDepsToAdd.back().second);
1127 ReverseDepsToAdd.pop_back();
1131 ReverseDepIt = ReverseNonLocalDeps.find(RemInst);
1132 if (ReverseDepIt != ReverseNonLocalDeps.end()) {
1133 SmallPtrSet<Instruction*, 4> &Set = ReverseDepIt->second;
1134 for (SmallPtrSet<Instruction*, 4>::iterator I = Set.begin(), E = Set.end();
1136 assert(*I != RemInst && "Already removed NonLocalDep info for RemInst");
1138 PerInstNLInfo &INLD = NonLocalDeps[*I];
1139 // The information is now dirty!
1142 for (NonLocalDepInfo::iterator DI = INLD.first.begin(),
1143 DE = INLD.first.end(); DI != DE; ++DI) {
1144 if (DI->getResult().getInst() != RemInst) continue;
1146 // Convert to a dirty entry for the subsequent instruction.
1147 DI->setResult(NewDirtyVal);
1149 if (Instruction *NextI = NewDirtyVal.getInst())
1150 ReverseDepsToAdd.push_back(std::make_pair(NextI, *I));
1154 ReverseNonLocalDeps.erase(ReverseDepIt);
1156 // Add new reverse deps after scanning the set, to avoid invalidating 'Set'
1157 while (!ReverseDepsToAdd.empty()) {
1158 ReverseNonLocalDeps[ReverseDepsToAdd.back().first]
1159 .insert(ReverseDepsToAdd.back().second);
1160 ReverseDepsToAdd.pop_back();
1164 // If the instruction is in ReverseNonLocalPtrDeps then it appears as a
1165 // value in the NonLocalPointerDeps info.
1166 ReverseNonLocalPtrDepTy::iterator ReversePtrDepIt =
1167 ReverseNonLocalPtrDeps.find(RemInst);
1168 if (ReversePtrDepIt != ReverseNonLocalPtrDeps.end()) {
1169 SmallPtrSet<ValueIsLoadPair, 4> &Set = ReversePtrDepIt->second;
1170 SmallVector<std::pair<Instruction*, ValueIsLoadPair>,8> ReversePtrDepsToAdd;
1172 for (SmallPtrSet<ValueIsLoadPair, 4>::iterator I = Set.begin(),
1173 E = Set.end(); I != E; ++I) {
1174 ValueIsLoadPair P = *I;
1175 assert(P.getPointer() != RemInst &&
1176 "Already removed NonLocalPointerDeps info for RemInst");
1178 NonLocalDepInfo &NLPDI = NonLocalPointerDeps[P].NonLocalDeps;
1180 // The cache is not valid for any specific block anymore.
1181 NonLocalPointerDeps[P].Pair = BBSkipFirstBlockPair();
1182 NonLocalPointerDeps[P].TBAATag = 0;
1184 // Update any entries for RemInst to use the instruction after it.
1185 for (NonLocalDepInfo::iterator DI = NLPDI.begin(), DE = NLPDI.end();
1187 if (DI->getResult().getInst() != RemInst) continue;
1189 // Convert to a dirty entry for the subsequent instruction.
1190 DI->setResult(NewDirtyVal);
1192 if (Instruction *NewDirtyInst = NewDirtyVal.getInst())
1193 ReversePtrDepsToAdd.push_back(std::make_pair(NewDirtyInst, P));
1196 // Re-sort the NonLocalDepInfo. Changing the dirty entry to its
1197 // subsequent value may invalidate the sortedness.
1198 std::sort(NLPDI.begin(), NLPDI.end());
1201 ReverseNonLocalPtrDeps.erase(ReversePtrDepIt);
1203 while (!ReversePtrDepsToAdd.empty()) {
1204 ReverseNonLocalPtrDeps[ReversePtrDepsToAdd.back().first]
1205 .insert(ReversePtrDepsToAdd.back().second);
1206 ReversePtrDepsToAdd.pop_back();
1211 assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?");
1212 AA->deleteValue(RemInst);
1213 DEBUG(verifyRemoved(RemInst));
1215 /// verifyRemoved - Verify that the specified instruction does not occur
1216 /// in our internal data structures.
1217 void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const {
1218 for (LocalDepMapType::const_iterator I = LocalDeps.begin(),
1219 E = LocalDeps.end(); I != E; ++I) {
1220 assert(I->first != D && "Inst occurs in data structures");
1221 assert(I->second.getInst() != D &&
1222 "Inst occurs in data structures");
1225 for (CachedNonLocalPointerInfo::const_iterator I =NonLocalPointerDeps.begin(),
1226 E = NonLocalPointerDeps.end(); I != E; ++I) {
1227 assert(I->first.getPointer() != D && "Inst occurs in NLPD map key");
1228 const NonLocalDepInfo &Val = I->second.NonLocalDeps;
1229 for (NonLocalDepInfo::const_iterator II = Val.begin(), E = Val.end();
1231 assert(II->getResult().getInst() != D && "Inst occurs as NLPD value");
1234 for (NonLocalDepMapType::const_iterator I = NonLocalDeps.begin(),
1235 E = NonLocalDeps.end(); I != E; ++I) {
1236 assert(I->first != D && "Inst occurs in data structures");
1237 const PerInstNLInfo &INLD = I->second;
1238 for (NonLocalDepInfo::const_iterator II = INLD.first.begin(),
1239 EE = INLD.first.end(); II != EE; ++II)
1240 assert(II->getResult().getInst() != D && "Inst occurs in data structures");
1243 for (ReverseDepMapType::const_iterator I = ReverseLocalDeps.begin(),
1244 E = ReverseLocalDeps.end(); I != E; ++I) {
1245 assert(I->first != D && "Inst occurs in data structures");
1246 for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(),
1247 EE = I->second.end(); II != EE; ++II)
1248 assert(*II != D && "Inst occurs in data structures");
1251 for (ReverseDepMapType::const_iterator I = ReverseNonLocalDeps.begin(),
1252 E = ReverseNonLocalDeps.end();
1254 assert(I->first != D && "Inst occurs in data structures");
1255 for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(),
1256 EE = I->second.end(); II != EE; ++II)
1257 assert(*II != D && "Inst occurs in data structures");
1260 for (ReverseNonLocalPtrDepTy::const_iterator
1261 I = ReverseNonLocalPtrDeps.begin(),
1262 E = ReverseNonLocalPtrDeps.end(); I != E; ++I) {
1263 assert(I->first != D && "Inst occurs in rev NLPD map");
1265 for (SmallPtrSet<ValueIsLoadPair, 4>::const_iterator II = I->second.begin(),
1266 E = I->second.end(); II != E; ++II)
1267 assert(*II != ValueIsLoadPair(D, false) &&
1268 *II != ValueIsLoadPair(D, true) &&
1269 "Inst occurs in ReverseNonLocalPtrDeps map");