#define DEBUG_TYPE "memdep"
#include "llvm/Analysis/MemoryDependenceAnalysis.h"
-#include "llvm/Constants.h"
#include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
#include "llvm/Function.h"
+#include "llvm/LLVMContext.h"
#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Analysis/PHITransAddr.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/PredIteratorCache.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Target/TargetData.h"
+#include "llvm/DataLayout.h"
using namespace llvm;
-STATISTIC(NumCacheNonLocal, "Number of cached non-local responses");
+STATISTIC(NumCacheNonLocal, "Number of fully cached non-local responses");
+STATISTIC(NumCacheDirtyNonLocal, "Number of dirty cached non-local responses");
STATISTIC(NumUncacheNonLocal, "Number of uncached non-local responses");
+STATISTIC(NumCacheNonLocalPtr,
+ "Number of fully cached non-local ptr responses");
+STATISTIC(NumCacheDirtyNonLocalPtr,
+ "Number of cached, but dirty, non-local ptr responses");
+STATISTIC(NumUncacheNonLocalPtr,
+ "Number of uncached non-local ptr responses");
+STATISTIC(NumCacheCompleteNonLocalPtr,
+ "Number of block queries that were completely cached");
+
+// Limit for the number of instructions to scan in a block.
+// FIXME: Figure out what a sane value is for this.
+// (500 is relatively insane.)
+static const int BlockScanLimit = 500;
+
char MemoryDependenceAnalysis::ID = 0;
// Register this pass...
-static RegisterPass<MemoryDependenceAnalysis> X("memdep",
- "Memory Dependence Analysis", false, true);
+INITIALIZE_PASS_BEGIN(MemoryDependenceAnalysis, "memdep",
+ "Memory Dependence Analysis", false, true)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
+INITIALIZE_PASS_END(MemoryDependenceAnalysis, "memdep",
+ "Memory Dependence Analysis", false, true)
+
+MemoryDependenceAnalysis::MemoryDependenceAnalysis()
+: FunctionPass(ID), PredCache(0) {
+ initializeMemoryDependenceAnalysisPass(*PassRegistry::getPassRegistry());
+}
+MemoryDependenceAnalysis::~MemoryDependenceAnalysis() {
+}
+
+/// Clean up memory in between runs
+void MemoryDependenceAnalysis::releaseMemory() {
+ LocalDeps.clear();
+ NonLocalDeps.clear();
+ NonLocalPointerDeps.clear();
+ ReverseLocalDeps.clear();
+ ReverseNonLocalDeps.clear();
+ ReverseNonLocalPtrDeps.clear();
+ PredCache->clear();
+}
+
+
/// getAnalysisUsage - Does not modify anything. It uses Alias Analysis.
///
void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequiredTransitive<AliasAnalysis>();
- AU.addRequiredTransitive<TargetData>();
}
-/// getCallSiteDependency - Private helper for finding the local dependencies
-/// of a call site.
-MemoryDependenceAnalysis::DepResultTy MemoryDependenceAnalysis::
-getCallSiteDependency(CallSite C, BasicBlock::iterator ScanIt,
- BasicBlock *BB) {
- AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
- TargetData &TD = getAnalysis<TargetData>();
-
+bool MemoryDependenceAnalysis::runOnFunction(Function &) {
+ AA = &getAnalysis<AliasAnalysis>();
+ TD = getAnalysisIfAvailable<DataLayout>();
+ DT = getAnalysisIfAvailable<DominatorTree>();
+ if (PredCache == 0)
+ PredCache.reset(new PredIteratorCache());
+ return false;
+}
+
+/// RemoveFromReverseMap - This is a helper function that removes Val from
+/// 'Inst's set in ReverseMap. If the set becomes empty, remove Inst's entry.
+template <typename KeyTy>
+static void RemoveFromReverseMap(DenseMap<Instruction*,
+ SmallPtrSet<KeyTy, 4> > &ReverseMap,
+ Instruction *Inst, KeyTy Val) {
+ typename DenseMap<Instruction*, SmallPtrSet<KeyTy, 4> >::iterator
+ InstIt = ReverseMap.find(Inst);
+ assert(InstIt != ReverseMap.end() && "Reverse map out of sync?");
+ bool Found = InstIt->second.erase(Val);
+ assert(Found && "Invalid reverse map!"); (void)Found;
+ if (InstIt->second.empty())
+ ReverseMap.erase(InstIt);
+}
+
+/// GetLocation - If the given instruction references a specific memory
+/// location, fill in Loc with the details, otherwise set Loc.Ptr to null.
+/// Return a ModRefInfo value describing the general behavior of the
+/// instruction.
+static
+AliasAnalysis::ModRefResult GetLocation(const Instruction *Inst,
+ AliasAnalysis::Location &Loc,
+ AliasAnalysis *AA) {
+ if (const LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
+ if (LI->isUnordered()) {
+ Loc = AA->getLocation(LI);
+ return AliasAnalysis::Ref;
+ } else if (LI->getOrdering() == Monotonic) {
+ Loc = AA->getLocation(LI);
+ return AliasAnalysis::ModRef;
+ }
+ Loc = AliasAnalysis::Location();
+ return AliasAnalysis::ModRef;
+ }
+
+ if (const StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
+ if (SI->isUnordered()) {
+ Loc = AA->getLocation(SI);
+ return AliasAnalysis::Mod;
+ } else if (SI->getOrdering() == Monotonic) {
+ Loc = AA->getLocation(SI);
+ return AliasAnalysis::ModRef;
+ }
+ Loc = AliasAnalysis::Location();
+ return AliasAnalysis::ModRef;
+ }
+
+ if (const VAArgInst *V = dyn_cast<VAArgInst>(Inst)) {
+ Loc = AA->getLocation(V);
+ return AliasAnalysis::ModRef;
+ }
+
+ if (const CallInst *CI = isFreeCall(Inst, AA->getTargetLibraryInfo())) {
+ // calls to free() deallocate the entire structure
+ Loc = AliasAnalysis::Location(CI->getArgOperand(0));
+ return AliasAnalysis::Mod;
+ }
+
+ if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst))
+ switch (II->getIntrinsicID()) {
+ case Intrinsic::lifetime_start:
+ case Intrinsic::lifetime_end:
+ case Intrinsic::invariant_start:
+ Loc = AliasAnalysis::Location(II->getArgOperand(1),
+ cast<ConstantInt>(II->getArgOperand(0))
+ ->getZExtValue(),
+ II->getMetadata(LLVMContext::MD_tbaa));
+ // These intrinsics don't really modify the memory, but returning Mod
+ // will allow them to be handled conservatively.
+ return AliasAnalysis::Mod;
+ case Intrinsic::invariant_end:
+ Loc = AliasAnalysis::Location(II->getArgOperand(2),
+ cast<ConstantInt>(II->getArgOperand(1))
+ ->getZExtValue(),
+ II->getMetadata(LLVMContext::MD_tbaa));
+ // These intrinsics don't really modify the memory, but returning Mod
+ // will allow them to be handled conservatively.
+ return AliasAnalysis::Mod;
+ default:
+ break;
+ }
+
+ // Otherwise, just do the coarse-grained thing that always works.
+ if (Inst->mayWriteToMemory())
+ return AliasAnalysis::ModRef;
+ if (Inst->mayReadFromMemory())
+ return AliasAnalysis::Ref;
+ return AliasAnalysis::NoModRef;
+}
+
+/// getCallSiteDependencyFrom - Private helper for finding the local
+/// dependencies of a call site.
+MemDepResult MemoryDependenceAnalysis::
+getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall,
+ BasicBlock::iterator ScanIt, BasicBlock *BB) {
+ unsigned Limit = BlockScanLimit;
+
// Walk backwards through the block, looking for dependencies
while (ScanIt != BB->begin()) {
+ // Limit the amount of scanning we do so we don't end up with quadratic
+ // running time on extreme testcases.
+ --Limit;
+ if (!Limit)
+ return MemDepResult::getUnknown();
+
Instruction *Inst = --ScanIt;
// If this inst is a memory op, get the pointer it accessed
- Value *Pointer = 0;
- uint64_t PointerSize = 0;
- if (StoreInst *S = dyn_cast<StoreInst>(Inst)) {
- Pointer = S->getPointerOperand();
- PointerSize = TD.getTypeStoreSize(S->getOperand(0)->getType());
- } else if (VAArgInst *V = dyn_cast<VAArgInst>(Inst)) {
- Pointer = V->getOperand(0);
- PointerSize = TD.getTypeStoreSize(V->getType());
- } else if (FreeInst *F = dyn_cast<FreeInst>(Inst)) {
- Pointer = F->getPointerOperand();
-
- // FreeInsts erase the entire structure
- PointerSize = ~0UL;
- } else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) {
- if (AA.getModRefBehavior(CallSite::get(Inst)) ==
- AliasAnalysis::DoesNotAccessMemory)
- continue;
- return DepResultTy(Inst, Normal);
- } else {
- // Non-memory instruction.
+ AliasAnalysis::Location Loc;
+ AliasAnalysis::ModRefResult MR = GetLocation(Inst, Loc, AA);
+ if (Loc.Ptr) {
+ // A simple instruction.
+ if (AA->getModRefInfo(CS, Loc) != AliasAnalysis::NoModRef)
+ return MemDepResult::getClobber(Inst);
continue;
}
-
- if (AA.getModRefInfo(C, Pointer, PointerSize) != AliasAnalysis::NoModRef)
- return DepResultTy(Inst, Normal);
+
+ if (CallSite InstCS = cast<Value>(Inst)) {
+ // Debug intrinsics don't cause dependences.
+ if (isa<DbgInfoIntrinsic>(Inst)) continue;
+ // If these two calls do not interfere, look past it.
+ switch (AA->getModRefInfo(CS, InstCS)) {
+ case AliasAnalysis::NoModRef:
+ // If the two calls are the same, return InstCS as a Def, so that
+ // CS can be found redundant and eliminated.
+ if (isReadOnlyCall && !(MR & AliasAnalysis::Mod) &&
+ CS.getInstruction()->isIdenticalToWhenDefined(Inst))
+ return MemDepResult::getDef(Inst);
+
+ // Otherwise if the two calls don't interact (e.g. InstCS is readnone)
+ // keep scanning.
+ continue;
+ default:
+ return MemDepResult::getClobber(Inst);
+ }
+ }
+
+ // If we could not obtain a pointer for the instruction and the instruction
+ // touches memory then assume that this is a dependency.
+ if (MR != AliasAnalysis::NoModRef)
+ return MemDepResult::getClobber(Inst);
}
+
+ // No dependence found. If this is the entry block of the function, it is
+ // unknown, otherwise it is non-local.
+ if (BB != &BB->getParent()->getEntryBlock())
+ return MemDepResult::getNonLocal();
+ return MemDepResult::getNonFuncLocal();
+}
+
+/// isLoadLoadClobberIfExtendedToFullWidth - Return true if LI is a load that
+/// would fully overlap MemLoc if done as a wider legal integer load.
+///
+/// MemLocBase, MemLocOffset are lazily computed here the first time the
+/// base/offs of memloc is needed.
+static bool
+isLoadLoadClobberIfExtendedToFullWidth(const AliasAnalysis::Location &MemLoc,
+ const Value *&MemLocBase,
+ int64_t &MemLocOffs,
+ const LoadInst *LI,
+ const DataLayout *TD) {
+ // If we have no target data, we can't do this.
+ if (TD == 0) return false;
+
+ // If we haven't already computed the base/offset of MemLoc, do so now.
+ if (MemLocBase == 0)
+ MemLocBase = GetPointerBaseWithConstantOffset(MemLoc.Ptr, MemLocOffs, *TD);
+
+ unsigned Size = MemoryDependenceAnalysis::
+ getLoadLoadClobberFullWidthSize(MemLocBase, MemLocOffs, MemLoc.Size,
+ LI, *TD);
+ return Size != 0;
+}
+
+/// getLoadLoadClobberFullWidthSize - This is a little bit of analysis that
+/// looks at a memory location for a load (specified by MemLocBase, Offs,
+/// and Size) and compares it against a load. If the specified load could
+/// be safely widened to a larger integer load that is 1) still efficient,
+/// 2) safe for the target, and 3) would provide the specified memory
+/// location value, then this function returns the size in bytes of the
+/// load width to use. If not, this returns zero.
+unsigned MemoryDependenceAnalysis::
+getLoadLoadClobberFullWidthSize(const Value *MemLocBase, int64_t MemLocOffs,
+ unsigned MemLocSize, const LoadInst *LI,
+ const DataLayout &TD) {
+ // We can only extend simple integer loads.
+ if (!isa<IntegerType>(LI->getType()) || !LI->isSimple()) return 0;
+
+ // Get the base of this load.
+ int64_t LIOffs = 0;
+ const Value *LIBase =
+ GetPointerBaseWithConstantOffset(LI->getPointerOperand(), LIOffs, TD);
+
+ // If the two pointers are not based on the same pointer, we can't tell that
+ // they are related.
+ if (LIBase != MemLocBase) return 0;
+
+ // Okay, the two values are based on the same pointer, but returned as
+ // no-alias. This happens when we have things like two byte loads at "P+1"
+ // and "P+3". Check to see if increasing the size of the "LI" load up to its
+ // alignment (or the largest native integer type) will allow us to load all
+ // the bits required by MemLoc.
+
+ // If MemLoc is before LI, then no widening of LI will help us out.
+ if (MemLocOffs < LIOffs) return 0;
- // No dependence found.
- return DepResultTy(0, NonLocal);
+ // Get the alignment of the load in bytes. We assume that it is safe to load
+ // any legal integer up to this size without a problem. For example, if we're
+ // looking at an i8 load on x86-32 that is known 1024 byte aligned, we can
+ // widen it up to an i32 load. If it is known 2-byte aligned, we can widen it
+ // to i16.
+ unsigned LoadAlign = LI->getAlignment();
+
+ int64_t MemLocEnd = MemLocOffs+MemLocSize;
+
+ // If no amount of rounding up will let MemLoc fit into LI, then bail out.
+ if (LIOffs+LoadAlign < MemLocEnd) return 0;
+
+ // This is the size of the load to try. Start with the next larger power of
+ // two.
+ unsigned NewLoadByteSize = LI->getType()->getPrimitiveSizeInBits()/8U;
+ NewLoadByteSize = NextPowerOf2(NewLoadByteSize);
+
+ while (1) {
+ // If this load size is bigger than our known alignment or would not fit
+ // into a native integer register, then we fail.
+ if (NewLoadByteSize > LoadAlign ||
+ !TD.fitsInLegalInteger(NewLoadByteSize*8))
+ return 0;
+
+ if (LIOffs+NewLoadByteSize > MemLocEnd &&
+ LI->getParent()->getParent()->getFnAttributes().hasAddressSafetyAttr()){
+ // We will be reading past the location accessed by the original program.
+ // While this is safe in a regular build, Address Safety analysis tools
+ // may start reporting false warnings. So, don't do widening.
+ return 0;
+ }
+
+ // If a load of this width would include all of MemLoc, then we succeed.
+ if (LIOffs+NewLoadByteSize >= MemLocEnd)
+ return NewLoadByteSize;
+
+ NewLoadByteSize <<= 1;
+ }
}
-/// getDependency - Return the instruction on which a memory operation
-/// depends. The local parameter indicates if the query should only
-/// evaluate dependencies within the same basic block.
-MemoryDependenceAnalysis::DepResultTy MemoryDependenceAnalysis::
-getDependencyFromInternal(Instruction *QueryInst, BasicBlock::iterator ScanIt,
- BasicBlock *BB) {
- AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
- TargetData &TD = getAnalysis<TargetData>();
-
- // Get the pointer value for which dependence will be determined
- Value *MemPtr = 0;
- uint64_t MemSize = 0;
- bool MemVolatile = false;
-
- if (StoreInst* S = dyn_cast<StoreInst>(QueryInst)) {
- MemPtr = S->getPointerOperand();
- MemSize = TD.getTypeStoreSize(S->getOperand(0)->getType());
- MemVolatile = S->isVolatile();
- } else if (LoadInst* L = dyn_cast<LoadInst>(QueryInst)) {
- MemPtr = L->getPointerOperand();
- MemSize = TD.getTypeStoreSize(L->getType());
- MemVolatile = L->isVolatile();
- } else if (VAArgInst* V = dyn_cast<VAArgInst>(QueryInst)) {
- MemPtr = V->getOperand(0);
- MemSize = TD.getTypeStoreSize(V->getType());
- } else if (FreeInst* F = dyn_cast<FreeInst>(QueryInst)) {
- MemPtr = F->getPointerOperand();
- // FreeInsts erase the entire structure, not just a field.
- MemSize = ~0UL;
- } else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst))
- return getCallSiteDependency(CallSite::get(QueryInst), ScanIt, BB);
- else // Non-memory instructions depend on nothing.
- return DepResultTy(0, None);
-
- // Walk backwards through the basic block, looking for dependencies
+/// getPointerDependencyFrom - Return the instruction on which a memory
+/// location depends. If isLoad is true, this routine ignores may-aliases with
+/// read-only operations. If isLoad is false, this routine ignores may-aliases
+/// with reads from read-only locations.
+MemDepResult MemoryDependenceAnalysis::
+getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad,
+ BasicBlock::iterator ScanIt, BasicBlock *BB) {
+
+ const Value *MemLocBase = 0;
+ int64_t MemLocOffset = 0;
+
+ unsigned Limit = BlockScanLimit;
+
+ // Walk backwards through the basic block, looking for dependencies.
while (ScanIt != BB->begin()) {
+ // Limit the amount of scanning we do so we don't end up with quadratic
+ // running time on extreme testcases.
+ --Limit;
+ if (!Limit)
+ return MemDepResult::getUnknown();
+
Instruction *Inst = --ScanIt;
- // If the access is volatile and this is a volatile load/store, return a
- // dependence.
- if (MemVolatile &&
- ((isa<LoadInst>(Inst) && cast<LoadInst>(Inst)->isVolatile()) ||
- (isa<StoreInst>(Inst) && cast<StoreInst>(Inst)->isVolatile())))
- return DepResultTy(Inst, Normal);
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
+ // Debug intrinsics don't (and can't) cause dependences.
+ if (isa<DbgInfoIntrinsic>(II)) continue;
+
+ // If we reach a lifetime begin or end marker, then the query ends here
+ // because the value is undefined.
+ if (II->getIntrinsicID() == Intrinsic::lifetime_start) {
+ // FIXME: This only considers queries directly on the invariant-tagged
+ // pointer, not on query pointers that are indexed off of them. It'd
+ // be nice to handle that at some point (the right approach is to use
+ // GetPointerBaseWithConstantOffset).
+ if (AA->isMustAlias(AliasAnalysis::Location(II->getArgOperand(1)),
+ MemLoc))
+ return MemDepResult::getDef(II);
+ continue;
+ }
+ }
// Values depend on loads if the pointers are must aliased. This means that
// a load depends on another must aliased load from the same value.
- if (LoadInst *L = dyn_cast<LoadInst>(Inst)) {
- Value *Pointer = L->getPointerOperand();
- uint64_t PointerSize = TD.getTypeStoreSize(L->getType());
+ if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
+ // Atomic loads have complications involved.
+ // FIXME: This is overly conservative.
+ if (!LI->isUnordered())
+ return MemDepResult::getClobber(LI);
+
+ AliasAnalysis::Location LoadLoc = AA->getLocation(LI);
- // If we found a pointer, check if it could be the same as our pointer
- AliasAnalysis::AliasResult R =
- AA.alias(Pointer, PointerSize, MemPtr, MemSize);
+ // If we found a pointer, check if it could be the same as our pointer.
+ AliasAnalysis::AliasResult R = AA->alias(LoadLoc, MemLoc);
+ if (isLoad) {
+ if (R == AliasAnalysis::NoAlias) {
+ // If this is an over-aligned integer load (for example,
+ // "load i8* %P, align 4") see if it would obviously overlap with the
+ // queried location if widened to a larger load (e.g. if the queried
+ // location is 1 byte at P+1). If so, return it as a load/load
+ // clobber result, allowing the client to decide to widen the load if
+ // it wants to.
+ if (IntegerType *ITy = dyn_cast<IntegerType>(LI->getType()))
+ if (LI->getAlignment()*8 > ITy->getPrimitiveSizeInBits() &&
+ isLoadLoadClobberIfExtendedToFullWidth(MemLoc, MemLocBase,
+ MemLocOffset, LI, TD))
+ return MemDepResult::getClobber(Inst);
+
+ continue;
+ }
+
+ // Must aliased loads are defs of each other.
+ if (R == AliasAnalysis::MustAlias)
+ return MemDepResult::getDef(Inst);
+
+#if 0 // FIXME: Temporarily disabled. GVN is cleverly rewriting loads
+ // in terms of clobbering loads, but since it does this by looking
+ // at the clobbering load directly, it doesn't know about any
+ // phi translation that may have happened along the way.
+
+ // If we have a partial alias, then return this as a clobber for the
+ // client to handle.
+ if (R == AliasAnalysis::PartialAlias)
+ return MemDepResult::getClobber(Inst);
+#endif
+
+ // Random may-alias loads don't depend on each other without a
+ // dependence.
+ continue;
+ }
+
+ // Stores don't depend on other no-aliased accesses.
if (R == AliasAnalysis::NoAlias)
continue;
+
+ // Stores don't alias loads from read-only memory.
+ if (AA->pointsToConstantMemory(LoadLoc))
+ continue;
+
+ // Stores depend on may/must aliased loads.
+ return MemDepResult::getDef(Inst);
+ }
+
+ if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
+ // Atomic stores have complications involved.
+ // FIXME: This is overly conservative.
+ if (!SI->isUnordered())
+ return MemDepResult::getClobber(SI);
+
+ // If alias analysis can tell that this store is guaranteed to not modify
+ // the query pointer, ignore it. Use getModRefInfo to handle cases where
+ // the query pointer points to constant memory etc.
+ if (AA->getModRefInfo(SI, MemLoc) == AliasAnalysis::NoModRef)
+ continue;
+
+ // Ok, this store might clobber the query pointer. Check to see if it is
+ // a must alias: in this case, we want to return this as a def.
+ AliasAnalysis::Location StoreLoc = AA->getLocation(SI);
- // May-alias loads don't depend on each other without a dependence.
- if (isa<LoadInst>(QueryInst) && R == AliasAnalysis::MayAlias)
+ // If we found a pointer, check if it could be the same as our pointer.
+ AliasAnalysis::AliasResult R = AA->alias(StoreLoc, MemLoc);
+
+ if (R == AliasAnalysis::NoAlias)
continue;
- return DepResultTy(Inst, Normal);
+ if (R == AliasAnalysis::MustAlias)
+ return MemDepResult::getDef(Inst);
+ return MemDepResult::getClobber(Inst);
}
// If this is an allocation, and if we know that the accessed pointer is to
- // the allocation, return None. This means that there is no dependence and
+ // the allocation, return Def. This means that there is no dependence and
// the access can be optimized based on that. For example, a load could
// turn into undef.
- if (AllocationInst *AI = dyn_cast<AllocationInst>(Inst)) {
- Value *AccessPtr = MemPtr->getUnderlyingObject();
+ // Note: Only determine this to be a malloc if Inst is the malloc call, not
+ // a subsequent bitcast of the malloc call result. There can be stores to
+ // the malloced memory between the malloc call and its bitcast uses, and we
+ // need to continue scanning until the malloc call.
+ const TargetLibraryInfo *TLI = AA->getTargetLibraryInfo();
+ if (isa<AllocaInst>(Inst) || isNoAliasFn(Inst, TLI)) {
+ const Value *AccessPtr = GetUnderlyingObject(MemLoc.Ptr, TD);
- if (AccessPtr == AI ||
- AA.alias(AI, 1, AccessPtr, 1) == AliasAnalysis::MustAlias)
- return DepResultTy(0, None);
- continue;
+ if (AccessPtr == Inst || AA->isMustAlias(Inst, AccessPtr))
+ return MemDepResult::getDef(Inst);
+ // Be conservative if the accessed pointer may alias the allocation.
+ if (AA->alias(Inst, AccessPtr) != AliasAnalysis::NoAlias)
+ return MemDepResult::getClobber(Inst);
+ // If the allocation is not aliased and does not read memory (like
+ // strdup), it is safe to ignore.
+ if (isa<AllocaInst>(Inst) ||
+ isMallocLikeFn(Inst, TLI) || isCallocLikeFn(Inst, TLI))
+ continue;
}
-
- // See if this instruction mod/ref's the pointer.
- AliasAnalysis::ModRefResult MRR = AA.getModRefInfo(Inst, MemPtr, MemSize);
- if (MRR == AliasAnalysis::NoModRef)
+ // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer.
+ AliasAnalysis::ModRefResult MR = AA->getModRefInfo(Inst, MemLoc);
+ // If necessary, perform additional analysis.
+ if (MR == AliasAnalysis::ModRef)
+ MR = AA->callCapturesBefore(Inst, MemLoc, DT);
+ switch (MR) {
+ case AliasAnalysis::NoModRef:
+ // If the call has no effect on the queried pointer, just ignore it.
continue;
-
- // Loads don't depend on read-only instructions.
- if (isa<LoadInst>(QueryInst) && MRR == AliasAnalysis::Ref)
- continue;
-
- // Otherwise, there is a dependence.
- return DepResultTy(Inst, Normal);
+ case AliasAnalysis::Mod:
+ return MemDepResult::getClobber(Inst);
+ case AliasAnalysis::Ref:
+ // If the call is known to never store to the pointer, and if this is a
+ // load query, we can safely ignore it (scan past it).
+ if (isLoad)
+ continue;
+ default:
+ // Otherwise, there is a potential dependence. Return a clobber.
+ return MemDepResult::getClobber(Inst);
+ }
}
- // If we found nothing, return the non-local flag.
- return DepResultTy(0, NonLocal);
+ // No dependence found. If this is the entry block of the function, it is
+ // unknown, otherwise it is non-local.
+ if (BB != &BB->getParent()->getEntryBlock())
+ return MemDepResult::getNonLocal();
+ return MemDepResult::getNonFuncLocal();
}
/// getDependency - Return the instruction on which a memory operation
Instruction *ScanPos = QueryInst;
// Check for a cached result
- DepResultTy &LocalCache = LocalDeps[QueryInst];
+ MemDepResult &LocalCache = LocalDeps[QueryInst];
// If the cached entry is non-dirty, just return it. Note that this depends
- // on DepResultTy's default constructing to 'dirty'.
- if (LocalCache.getInt() != Dirty)
- return ConvToResult(LocalCache);
+ // on MemDepResult's default constructing to 'dirty'.
+ if (!LocalCache.isDirty())
+ return LocalCache;
// Otherwise, if we have a dirty entry, we know we can start the scan at that
// instruction, which may save us some work.
- if (Instruction *Inst = LocalCache.getPointer())
+ if (Instruction *Inst = LocalCache.getInst()) {
ScanPos = Inst;
+
+ RemoveFromReverseMap(ReverseLocalDeps, Inst, QueryInst);
+ }
+
+ BasicBlock *QueryParent = QueryInst->getParent();
// Do the scan.
- LocalCache = getDependencyFromInternal(QueryInst, ScanPos,
- QueryInst->getParent());
+ if (BasicBlock::iterator(QueryInst) == QueryParent->begin()) {
+ // No dependence found. If this is the entry block of the function, it is
+ // unknown, otherwise it is non-local.
+ if (QueryParent != &QueryParent->getParent()->getEntryBlock())
+ LocalCache = MemDepResult::getNonLocal();
+ else
+ LocalCache = MemDepResult::getNonFuncLocal();
+ } else {
+ AliasAnalysis::Location MemLoc;
+ AliasAnalysis::ModRefResult MR = GetLocation(QueryInst, MemLoc, AA);
+ if (MemLoc.Ptr) {
+ // If we can do a pointer scan, make it happen.
+ bool isLoad = !(MR & AliasAnalysis::Mod);
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(QueryInst))
+ isLoad |= II->getIntrinsicID() == Intrinsic::lifetime_start;
+
+ LocalCache = getPointerDependencyFrom(MemLoc, isLoad, ScanPos,
+ QueryParent);
+ } else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)) {
+ CallSite QueryCS(QueryInst);
+ bool isReadOnly = AA->onlyReadsMemory(QueryCS);
+ LocalCache = getCallSiteDependencyFrom(QueryCS, isReadOnly, ScanPos,
+ QueryParent);
+ } else
+ // Non-memory instruction.
+ LocalCache = MemDepResult::getUnknown();
+ }
// Remember the result!
- if (Instruction *I = LocalCache.getPointer())
+ if (Instruction *I = LocalCache.getInst())
ReverseLocalDeps[I].insert(QueryInst);
- return ConvToResult(LocalCache);
+ return LocalCache;
}
-/// getNonLocalDependency - Perform a full dependency query for the
-/// specified instruction, returning the set of blocks that the value is
+#ifndef NDEBUG
+/// AssertSorted - This method is used when -debug is specified to verify that
+/// cache arrays are properly kept sorted.
+static void AssertSorted(MemoryDependenceAnalysis::NonLocalDepInfo &Cache,
+ int Count = -1) {
+ if (Count == -1) Count = Cache.size();
+ if (Count == 0) return;
+
+ for (unsigned i = 1; i != unsigned(Count); ++i)
+ assert(!(Cache[i] < Cache[i-1]) && "Cache isn't sorted!");
+}
+#endif
+
+/// getNonLocalCallDependency - Perform a full dependency query for the
+/// specified call, returning the set of blocks that the value is
/// potentially live across. The returned set of results will include a
/// "NonLocal" result for all blocks where the value is live across.
///
-/// This method assumes the instruction returns a "nonlocal" dependency
+/// This method assumes the instruction returns a "NonLocal" dependency
/// within its own block.
///
-void MemoryDependenceAnalysis::
-getNonLocalDependency(Instruction *QueryInst,
- SmallVectorImpl<std::pair<BasicBlock*,
- MemDepResult> > &Result) {
- assert(getDependency(QueryInst).isNonLocal() &&
- "getNonLocalDependency should only be used on insts with non-local deps!");
- NonLocalDepInfo *&CacheP = NonLocalDeps[QueryInst];
- if (CacheP == 0) CacheP = new NonLocalDepInfo();
-
- NonLocalDepInfo &Cache = *CacheP;
+/// This returns a reference to an internal data structure that may be
+/// invalidated on the next non-local query or when an instruction is
+/// removed. Clients must copy this data if they want it around longer than
+/// that.
+const MemoryDependenceAnalysis::NonLocalDepInfo &
+MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) {
+ assert(getDependency(QueryCS.getInstruction()).isNonLocal() &&
+ "getNonLocalCallDependency should only be used on calls with non-local deps!");
+ PerInstNLInfo &CacheP = NonLocalDeps[QueryCS.getInstruction()];
+ NonLocalDepInfo &Cache = CacheP.first;
/// DirtyBlocks - This is the set of blocks that need to be recomputed. In
/// the cached case, this can happen due to instructions being deleted etc. In
SmallVector<BasicBlock*, 32> DirtyBlocks;
if (!Cache.empty()) {
+ // Okay, we have a cache entry. If we know it is not dirty, just return it
+ // with no computation.
+ if (!CacheP.second) {
+ ++NumCacheNonLocal;
+ return Cache;
+ }
+
// If we already have a partially computed set of results, scan them to
// determine what is dirty, seeding our initial DirtyBlocks worklist.
- // FIXME: In the "don't need to be updated" case, this is expensive, why not
- // have a per-"cache" flag saying it is undirty?
for (NonLocalDepInfo::iterator I = Cache.begin(), E = Cache.end();
- I != E; ++I)
- if (I->second.getInt() == Dirty)
- DirtyBlocks.push_back(I->first);
+ I != E; ++I)
+ if (I->getResult().isDirty())
+ DirtyBlocks.push_back(I->getBB());
- NumCacheNonLocal++;
+ // Sort the cache so that we can do fast binary search lookups below.
+ std::sort(Cache.begin(), Cache.end());
+ ++NumCacheDirtyNonLocal;
//cerr << "CACHED CASE: " << DirtyBlocks.size() << " dirty: "
// << Cache.size() << " cached: " << *QueryInst;
} else {
// Seed DirtyBlocks with each of the preds of QueryInst's block.
- BasicBlock *QueryBB = QueryInst->getParent();
- DirtyBlocks.append(pred_begin(QueryBB), pred_end(QueryBB));
- NumUncacheNonLocal++;
+ BasicBlock *QueryBB = QueryCS.getInstruction()->getParent();
+ for (BasicBlock **PI = PredCache->GetPreds(QueryBB); *PI; ++PI)
+ DirtyBlocks.push_back(*PI);
+ ++NumUncacheNonLocal;
}
+ // isReadonlyCall - If this is a read-only call, we can be more aggressive.
+ bool isReadonlyCall = AA->onlyReadsMemory(QueryCS);
+
+ SmallPtrSet<BasicBlock*, 64> Visited;
+
+ unsigned NumSortedEntries = Cache.size();
+ DEBUG(AssertSorted(Cache));
+
// Iterate while we still have blocks to update.
while (!DirtyBlocks.empty()) {
BasicBlock *DirtyBB = DirtyBlocks.back();
DirtyBlocks.pop_back();
- // Get the entry for this block. Note that this relies on DepResultTy
- // default initializing to Dirty.
- DepResultTy &DirtyBBEntry = Cache[DirtyBB];
+ // Already processed this block?
+ if (!Visited.insert(DirtyBB))
+ continue;
+
+ // Do a binary search to see if we already have an entry for this block in
+ // the cache set. If so, find it.
+ DEBUG(AssertSorted(Cache, NumSortedEntries));
+ NonLocalDepInfo::iterator Entry =
+ std::upper_bound(Cache.begin(), Cache.begin()+NumSortedEntries,
+ NonLocalDepEntry(DirtyBB));
+ if (Entry != Cache.begin() && prior(Entry)->getBB() == DirtyBB)
+ --Entry;
+
+ NonLocalDepEntry *ExistingResult = 0;
+ if (Entry != Cache.begin()+NumSortedEntries &&
+ Entry->getBB() == DirtyBB) {
+ // If we already have an entry, and if it isn't already dirty, the block
+ // is done.
+ if (!Entry->getResult().isDirty())
+ continue;
+
+ // Otherwise, remember this slot so we can update the value.
+ ExistingResult = &*Entry;
+ }
- // If DirtyBBEntry isn't dirty, it ended up on the worklist multiple times.
- if (DirtyBBEntry.getInt() != Dirty) continue;
-
// If the dirty entry has a pointer, start scanning from it so we don't have
// to rescan the entire block.
BasicBlock::iterator ScanPos = DirtyBB->end();
- if (Instruction *Inst = DirtyBBEntry.getPointer()) {
- ScanPos = Inst;
-
- // We're removing QueryInst's dependence on Inst.
- SmallPtrSet<Instruction*, 4> &InstMap = ReverseNonLocalDeps[Inst];
- InstMap.erase(QueryInst);
- if (InstMap.empty()) ReverseNonLocalDeps.erase(Inst);
+ if (ExistingResult) {
+ if (Instruction *Inst = ExistingResult->getResult().getInst()) {
+ ScanPos = Inst;
+ // We're removing QueryInst's use of Inst.
+ RemoveFromReverseMap(ReverseNonLocalDeps, Inst,
+ QueryCS.getInstruction());
+ }
}
// Find out if this block has a local dependency for QueryInst.
- DirtyBBEntry = getDependencyFromInternal(QueryInst, ScanPos, DirtyBB);
-
+ MemDepResult Dep;
+
+ if (ScanPos != DirtyBB->begin()) {
+ Dep = getCallSiteDependencyFrom(QueryCS, isReadonlyCall,ScanPos, DirtyBB);
+ } else if (DirtyBB != &DirtyBB->getParent()->getEntryBlock()) {
+ // No dependence found. If this is the entry block of the function, it is
+ // a clobber, otherwise it is unknown.
+ Dep = MemDepResult::getNonLocal();
+ } else {
+ Dep = MemDepResult::getNonFuncLocal();
+ }
+
+ // If we had a dirty entry for the block, update it. Otherwise, just add
+ // a new entry.
+ if (ExistingResult)
+ ExistingResult->setResult(Dep);
+ else
+ Cache.push_back(NonLocalDepEntry(DirtyBB, Dep));
+
// If the block has a dependency (i.e. it isn't completely transparent to
- // the value), remember it!
- if (DirtyBBEntry.getInt() != NonLocal) {
+ // the value), remember the association!
+ if (!Dep.isNonLocal()) {
// Keep the ReverseNonLocalDeps map up to date so we can efficiently
// update this when we remove instructions.
- if (Instruction *Inst = DirtyBBEntry.getPointer())
- ReverseNonLocalDeps[Inst].insert(QueryInst);
+ if (Instruction *Inst = Dep.getInst())
+ ReverseNonLocalDeps[Inst].insert(QueryCS.getInstruction());
+ } else {
+
+ // If the block *is* completely transparent to the load, we need to check
+ // the predecessors of this block. Add them to our worklist.
+ for (BasicBlock **PI = PredCache->GetPreds(DirtyBB); *PI; ++PI)
+ DirtyBlocks.push_back(*PI);
+ }
+ }
+
+ return Cache;
+}
+
+/// getNonLocalPointerDependency - Perform a full dependency query for an
+/// access to the specified (non-volatile) memory location, returning the
+/// set of instructions that either define or clobber the value.
+///
+/// This method assumes the pointer has a "NonLocal" dependency within its
+/// own block.
+///
+void MemoryDependenceAnalysis::
+getNonLocalPointerDependency(const AliasAnalysis::Location &Loc, bool isLoad,
+ BasicBlock *FromBB,
+ SmallVectorImpl<NonLocalDepResult> &Result) {
+ assert(Loc.Ptr->getType()->isPointerTy() &&
+ "Can't get pointer deps of a non-pointer!");
+ Result.clear();
+
+ PHITransAddr Address(const_cast<Value *>(Loc.Ptr), TD);
+
+ // This is the set of blocks we've inspected, and the pointer we consider in
+ // each block. Because of critical edges, we currently bail out if querying
+ // a block with multiple different pointers. This can happen during PHI
+ // translation.
+ DenseMap<BasicBlock*, Value*> Visited;
+ if (!getNonLocalPointerDepFromBB(Address, Loc, isLoad, FromBB,
+ Result, Visited, true))
+ return;
+ Result.clear();
+ Result.push_back(NonLocalDepResult(FromBB,
+ MemDepResult::getUnknown(),
+ const_cast<Value *>(Loc.Ptr)));
+}
+
+/// GetNonLocalInfoForBlock - Compute the memdep value for BB with
+/// Pointer/PointeeSize using either cached information in Cache or by doing a
+/// lookup (which may use dirty cache info if available). If we do a lookup,
+/// add the result to the cache.
+MemDepResult MemoryDependenceAnalysis::
+GetNonLocalInfoForBlock(const AliasAnalysis::Location &Loc,
+ bool isLoad, BasicBlock *BB,
+ NonLocalDepInfo *Cache, unsigned NumSortedEntries) {
+
+ // Do a binary search to see if we already have an entry for this block in
+ // the cache set. If so, find it.
+ NonLocalDepInfo::iterator Entry =
+ std::upper_bound(Cache->begin(), Cache->begin()+NumSortedEntries,
+ NonLocalDepEntry(BB));
+ if (Entry != Cache->begin() && (Entry-1)->getBB() == BB)
+ --Entry;
+
+ NonLocalDepEntry *ExistingResult = 0;
+ if (Entry != Cache->begin()+NumSortedEntries && Entry->getBB() == BB)
+ ExistingResult = &*Entry;
+
+ // If we have a cached entry, and it is non-dirty, use it as the value for
+ // this dependency.
+ if (ExistingResult && !ExistingResult->getResult().isDirty()) {
+ ++NumCacheNonLocalPtr;
+ return ExistingResult->getResult();
+ }
+
+ // Otherwise, we have to scan for the value. If we have a dirty cache
+ // entry, start scanning from its position, otherwise we scan from the end
+ // of the block.
+ BasicBlock::iterator ScanPos = BB->end();
+ if (ExistingResult && ExistingResult->getResult().getInst()) {
+ assert(ExistingResult->getResult().getInst()->getParent() == BB &&
+ "Instruction invalidated?");
+ ++NumCacheDirtyNonLocalPtr;
+ ScanPos = ExistingResult->getResult().getInst();
+
+ // Eliminating the dirty entry from 'Cache', so update the reverse info.
+ ValueIsLoadPair CacheKey(Loc.Ptr, isLoad);
+ RemoveFromReverseMap(ReverseNonLocalPtrDeps, ScanPos, CacheKey);
+ } else {
+ ++NumUncacheNonLocalPtr;
+ }
+
+ // Scan the block for the dependency.
+ MemDepResult Dep = getPointerDependencyFrom(Loc, isLoad, ScanPos, BB);
+
+ // If we had a dirty entry for the block, update it. Otherwise, just add
+ // a new entry.
+ if (ExistingResult)
+ ExistingResult->setResult(Dep);
+ else
+ Cache->push_back(NonLocalDepEntry(BB, Dep));
+
+ // If the block has a dependency (i.e. it isn't completely transparent to
+ // the value), remember the reverse association because we just added it
+ // to Cache!
+ if (!Dep.isDef() && !Dep.isClobber())
+ return Dep;
+
+ // Keep the ReverseNonLocalPtrDeps map up to date so we can efficiently
+ // update MemDep when we remove instructions.
+ Instruction *Inst = Dep.getInst();
+ assert(Inst && "Didn't depend on anything?");
+ ValueIsLoadPair CacheKey(Loc.Ptr, isLoad);
+ ReverseNonLocalPtrDeps[Inst].insert(CacheKey);
+ return Dep;
+}
+
+/// SortNonLocalDepInfoCache - Sort the a NonLocalDepInfo cache, given a certain
+/// number of elements in the array that are already properly ordered. This is
+/// optimized for the case when only a few entries are added.
+static void
+SortNonLocalDepInfoCache(MemoryDependenceAnalysis::NonLocalDepInfo &Cache,
+ unsigned NumSortedEntries) {
+ switch (Cache.size() - NumSortedEntries) {
+ case 0:
+ // done, no new entries.
+ break;
+ case 2: {
+ // Two new entries, insert the last one into place.
+ NonLocalDepEntry Val = Cache.back();
+ Cache.pop_back();
+ MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry =
+ std::upper_bound(Cache.begin(), Cache.end()-1, Val);
+ Cache.insert(Entry, Val);
+ // FALL THROUGH.
+ }
+ case 1:
+ // One new entry, Just insert the new value at the appropriate position.
+ if (Cache.size() != 1) {
+ NonLocalDepEntry Val = Cache.back();
+ Cache.pop_back();
+ MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry =
+ std::upper_bound(Cache.begin(), Cache.end(), Val);
+ Cache.insert(Entry, Val);
+ }
+ break;
+ default:
+ // Added many values, do a full scale sort.
+ std::sort(Cache.begin(), Cache.end());
+ break;
+ }
+}
+
+/// getNonLocalPointerDepFromBB - Perform a dependency query based on
+/// pointer/pointeesize starting at the end of StartBB. Add any clobber/def
+/// results to the results vector and keep track of which blocks are visited in
+/// 'Visited'.
+///
+/// This has special behavior for the first block queries (when SkipFirstBlock
+/// is true). In this special case, it ignores the contents of the specified
+/// block and starts returning dependence info for its predecessors.
+///
+/// This function returns false on success, or true to indicate that it could
+/// not compute dependence information for some reason. This should be treated
+/// as a clobber dependence on the first instruction in the predecessor block.
+bool MemoryDependenceAnalysis::
+getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
+ const AliasAnalysis::Location &Loc,
+ bool isLoad, BasicBlock *StartBB,
+ SmallVectorImpl<NonLocalDepResult> &Result,
+ DenseMap<BasicBlock*, Value*> &Visited,
+ bool SkipFirstBlock) {
+
+ // Look up the cached info for Pointer.
+ ValueIsLoadPair CacheKey(Pointer.getAddr(), isLoad);
+
+ // Set up a temporary NLPI value. If the map doesn't yet have an entry for
+ // CacheKey, this value will be inserted as the associated value. Otherwise,
+ // it'll be ignored, and we'll have to check to see if the cached size and
+ // tbaa tag are consistent with the current query.
+ NonLocalPointerInfo InitialNLPI;
+ InitialNLPI.Size = Loc.Size;
+ InitialNLPI.TBAATag = Loc.TBAATag;
+
+ // Get the NLPI for CacheKey, inserting one into the map if it doesn't
+ // already have one.
+ std::pair<CachedNonLocalPointerInfo::iterator, bool> Pair =
+ NonLocalPointerDeps.insert(std::make_pair(CacheKey, InitialNLPI));
+ NonLocalPointerInfo *CacheInfo = &Pair.first->second;
+
+ // If we already have a cache entry for this CacheKey, we may need to do some
+ // work to reconcile the cache entry and the current query.
+ if (!Pair.second) {
+ if (CacheInfo->Size < Loc.Size) {
+ // The query's Size is greater than the cached one. Throw out the
+ // cached data and proceed with the query at the greater size.
+ CacheInfo->Pair = BBSkipFirstBlockPair();
+ CacheInfo->Size = Loc.Size;
+ for (NonLocalDepInfo::iterator DI = CacheInfo->NonLocalDeps.begin(),
+ DE = CacheInfo->NonLocalDeps.end(); DI != DE; ++DI)
+ if (Instruction *Inst = DI->getResult().getInst())
+ RemoveFromReverseMap(ReverseNonLocalPtrDeps, Inst, CacheKey);
+ CacheInfo->NonLocalDeps.clear();
+ } else if (CacheInfo->Size > Loc.Size) {
+ // This query's Size is less than the cached one. Conservatively restart
+ // the query using the greater size.
+ return getNonLocalPointerDepFromBB(Pointer,
+ Loc.getWithNewSize(CacheInfo->Size),
+ isLoad, StartBB, Result, Visited,
+ SkipFirstBlock);
+ }
+
+ // If the query's TBAATag is inconsistent with the cached one,
+ // conservatively throw out the cached data and restart the query with
+ // no tag if needed.
+ if (CacheInfo->TBAATag != Loc.TBAATag) {
+ if (CacheInfo->TBAATag) {
+ CacheInfo->Pair = BBSkipFirstBlockPair();
+ CacheInfo->TBAATag = 0;
+ for (NonLocalDepInfo::iterator DI = CacheInfo->NonLocalDeps.begin(),
+ DE = CacheInfo->NonLocalDeps.end(); DI != DE; ++DI)
+ if (Instruction *Inst = DI->getResult().getInst())
+ RemoveFromReverseMap(ReverseNonLocalPtrDeps, Inst, CacheKey);
+ CacheInfo->NonLocalDeps.clear();
+ }
+ if (Loc.TBAATag)
+ return getNonLocalPointerDepFromBB(Pointer, Loc.getWithoutTBAATag(),
+ isLoad, StartBB, Result, Visited,
+ SkipFirstBlock);
+ }
+ }
+
+ NonLocalDepInfo *Cache = &CacheInfo->NonLocalDeps;
+
+ // If we have valid cached information for exactly the block we are
+ // investigating, just return it with no recomputation.
+ if (CacheInfo->Pair == BBSkipFirstBlockPair(StartBB, SkipFirstBlock)) {
+ // We have a fully cached result for this query then we can just return the
+ // cached results and populate the visited set. However, we have to verify
+ // that we don't already have conflicting results for these blocks. Check
+ // to ensure that if a block in the results set is in the visited set that
+ // it was for the same pointer query.
+ if (!Visited.empty()) {
+ for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end();
+ I != E; ++I) {
+ DenseMap<BasicBlock*, Value*>::iterator VI = Visited.find(I->getBB());
+ if (VI == Visited.end() || VI->second == Pointer.getAddr())
+ continue;
+
+ // We have a pointer mismatch in a block. Just return clobber, saying
+ // that something was clobbered in this result. We could also do a
+ // non-fully cached query, but there is little point in doing this.
+ return true;
+ }
+ }
+
+ Value *Addr = Pointer.getAddr();
+ for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end();
+ I != E; ++I) {
+ Visited.insert(std::make_pair(I->getBB(), Addr));
+ if (!I->getResult().isNonLocal())
+ Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(), Addr));
+ }
+ ++NumCacheCompleteNonLocalPtr;
+ return false;
+ }
+
+ // Otherwise, either this is a new block, a block with an invalid cache
+ // pointer or one that we're about to invalidate by putting more info into it
+ // than its valid cache info. If empty, the result will be valid cache info,
+ // otherwise it isn't.
+ if (Cache->empty())
+ CacheInfo->Pair = BBSkipFirstBlockPair(StartBB, SkipFirstBlock);
+ else
+ CacheInfo->Pair = BBSkipFirstBlockPair();
+
+ SmallVector<BasicBlock*, 32> Worklist;
+ Worklist.push_back(StartBB);
+
+ // PredList used inside loop.
+ SmallVector<std::pair<BasicBlock*, PHITransAddr>, 16> PredList;
+
+ // Keep track of the entries that we know are sorted. Previously cached
+ // entries will all be sorted. The entries we add we only sort on demand (we
+ // don't insert every element into its sorted position). We know that we
+ // won't get any reuse from currently inserted values, because we don't
+ // revisit blocks after we insert info for them.
+ unsigned NumSortedEntries = Cache->size();
+ DEBUG(AssertSorted(*Cache));
+
+ while (!Worklist.empty()) {
+ BasicBlock *BB = Worklist.pop_back_val();
+
+ // Skip the first block if we have it.
+ if (!SkipFirstBlock) {
+ // Analyze the dependency of *Pointer in FromBB. See if we already have
+ // been here.
+ assert(Visited.count(BB) && "Should check 'visited' before adding to WL");
+
+ // Get the dependency info for Pointer in BB. If we have cached
+ // information, we will use it, otherwise we compute it.
+ DEBUG(AssertSorted(*Cache, NumSortedEntries));
+ MemDepResult Dep = GetNonLocalInfoForBlock(Loc, isLoad, BB, Cache,
+ NumSortedEntries);
+
+ // If we got a Def or Clobber, add this to the list of results.
+ if (!Dep.isNonLocal()) {
+ Result.push_back(NonLocalDepResult(BB, Dep, Pointer.getAddr()));
+ continue;
+ }
+ }
+
+ // If 'Pointer' is an instruction defined in this block, then we need to do
+ // phi translation to change it into a value live in the predecessor block.
+ // If not, we just add the predecessors to the worklist and scan them with
+ // the same Pointer.
+ if (!Pointer.NeedsPHITranslationFromBlock(BB)) {
+ SkipFirstBlock = false;
+ SmallVector<BasicBlock*, 16> NewBlocks;
+ for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) {
+ // Verify that we haven't looked at this block yet.
+ std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool>
+ InsertRes = Visited.insert(std::make_pair(*PI, Pointer.getAddr()));
+ if (InsertRes.second) {
+ // First time we've looked at *PI.
+ NewBlocks.push_back(*PI);
+ continue;
+ }
+
+ // If we have seen this block before, but it was with a different
+ // pointer then we have a phi translation failure and we have to treat
+ // this as a clobber.
+ if (InsertRes.first->second != Pointer.getAddr()) {
+ // Make sure to clean up the Visited map before continuing on to
+ // PredTranslationFailure.
+ for (unsigned i = 0; i < NewBlocks.size(); i++)
+ Visited.erase(NewBlocks[i]);
+ goto PredTranslationFailure;
+ }
+ }
+ Worklist.append(NewBlocks.begin(), NewBlocks.end());
continue;
}
- // If the block *is* completely transparent to the load, we need to check
- // the predecessors of this block. Add them to our worklist.
- DirtyBlocks.append(pred_begin(DirtyBB), pred_end(DirtyBB));
+ // We do need to do phi translation, if we know ahead of time we can't phi
+ // translate this value, don't even try.
+ if (!Pointer.IsPotentiallyPHITranslatable())
+ goto PredTranslationFailure;
+
+ // We may have added values to the cache list before this PHI translation.
+ // If so, we haven't done anything to ensure that the cache remains sorted.
+ // Sort it now (if needed) so that recursive invocations of
+ // getNonLocalPointerDepFromBB and other routines that could reuse the cache
+ // value will only see properly sorted cache arrays.
+ if (Cache && NumSortedEntries != Cache->size()) {
+ SortNonLocalDepInfoCache(*Cache, NumSortedEntries);
+ NumSortedEntries = Cache->size();
+ }
+ Cache = 0;
+
+ PredList.clear();
+ for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) {
+ BasicBlock *Pred = *PI;
+ PredList.push_back(std::make_pair(Pred, Pointer));
+
+ // Get the PHI translated pointer in this predecessor. This can fail if
+ // not translatable, in which case the getAddr() returns null.
+ PHITransAddr &PredPointer = PredList.back().second;
+ PredPointer.PHITranslateValue(BB, Pred, 0);
+
+ Value *PredPtrVal = PredPointer.getAddr();
+
+ // Check to see if we have already visited this pred block with another
+ // pointer. If so, we can't do this lookup. This failure can occur
+ // with PHI translation when a critical edge exists and the PHI node in
+ // the successor translates to a pointer value different than the
+ // pointer the block was first analyzed with.
+ std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool>
+ InsertRes = Visited.insert(std::make_pair(Pred, PredPtrVal));
+
+ if (!InsertRes.second) {
+ // We found the pred; take it off the list of preds to visit.
+ PredList.pop_back();
+
+ // If the predecessor was visited with PredPtr, then we already did
+ // the analysis and can ignore it.
+ if (InsertRes.first->second == PredPtrVal)
+ continue;
+
+ // Otherwise, the block was previously analyzed with a different
+ // pointer. We can't represent the result of this case, so we just
+ // treat this as a phi translation failure.
+
+ // Make sure to clean up the Visited map before continuing on to
+ // PredTranslationFailure.
+ for (unsigned i = 0; i < PredList.size(); i++)
+ Visited.erase(PredList[i].first);
+
+ goto PredTranslationFailure;
+ }
+ }
+
+ // Actually process results here; this need to be a separate loop to avoid
+ // calling getNonLocalPointerDepFromBB for blocks we don't want to return
+ // any results for. (getNonLocalPointerDepFromBB will modify our
+ // datastructures in ways the code after the PredTranslationFailure label
+ // doesn't expect.)
+ for (unsigned i = 0; i < PredList.size(); i++) {
+ BasicBlock *Pred = PredList[i].first;
+ PHITransAddr &PredPointer = PredList[i].second;
+ Value *PredPtrVal = PredPointer.getAddr();
+
+ bool CanTranslate = true;
+ // If PHI translation was unable to find an available pointer in this
+ // predecessor, then we have to assume that the pointer is clobbered in
+ // that predecessor. We can still do PRE of the load, which would insert
+ // a computation of the pointer in this predecessor.
+ if (PredPtrVal == 0)
+ CanTranslate = false;
+
+ // FIXME: it is entirely possible that PHI translating will end up with
+ // the same value. Consider PHI translating something like:
+ // X = phi [x, bb1], [y, bb2]. PHI translating for bb1 doesn't *need*
+ // to recurse here, pedantically speaking.
+
+ // If getNonLocalPointerDepFromBB fails here, that means the cached
+ // result conflicted with the Visited list; we have to conservatively
+ // assume it is unknown, but this also does not block PRE of the load.
+ if (!CanTranslate ||
+ getNonLocalPointerDepFromBB(PredPointer,
+ Loc.getWithNewPtr(PredPtrVal),
+ isLoad, Pred,
+ Result, Visited)) {
+ // Add the entry to the Result list.
+ NonLocalDepResult Entry(Pred, MemDepResult::getUnknown(), PredPtrVal);
+ Result.push_back(Entry);
+
+ // Since we had a phi translation failure, the cache for CacheKey won't
+ // include all of the entries that we need to immediately satisfy future
+ // queries. Mark this in NonLocalPointerDeps by setting the
+ // BBSkipFirstBlockPair pointer to null. This requires reuse of the
+ // cached value to do more work but not miss the phi trans failure.
+ NonLocalPointerInfo &NLPI = NonLocalPointerDeps[CacheKey];
+ NLPI.Pair = BBSkipFirstBlockPair();
+ continue;
+ }
+ }
+
+ // Refresh the CacheInfo/Cache pointer so that it isn't invalidated.
+ CacheInfo = &NonLocalPointerDeps[CacheKey];
+ Cache = &CacheInfo->NonLocalDeps;
+ NumSortedEntries = Cache->size();
+
+ // Since we did phi translation, the "Cache" set won't contain all of the
+ // results for the query. This is ok (we can still use it to accelerate
+ // specific block queries) but we can't do the fastpath "return all
+ // results from the set" Clear out the indicator for this.
+ CacheInfo->Pair = BBSkipFirstBlockPair();
+ SkipFirstBlock = false;
+ continue;
+
+ PredTranslationFailure:
+ // The following code is "failure"; we can't produce a sane translation
+ // for the given block. It assumes that we haven't modified any of
+ // our datastructures while processing the current block.
+
+ if (Cache == 0) {
+ // Refresh the CacheInfo/Cache pointer if it got invalidated.
+ CacheInfo = &NonLocalPointerDeps[CacheKey];
+ Cache = &CacheInfo->NonLocalDeps;
+ NumSortedEntries = Cache->size();
+ }
+
+ // Since we failed phi translation, the "Cache" set won't contain all of the
+ // results for the query. This is ok (we can still use it to accelerate
+ // specific block queries) but we can't do the fastpath "return all
+ // results from the set". Clear out the indicator for this.
+ CacheInfo->Pair = BBSkipFirstBlockPair();
+
+ // If *nothing* works, mark the pointer as unknown.
+ //
+ // If this is the magic first block, return this as a clobber of the whole
+ // incoming value. Since we can't phi translate to one of the predecessors,
+ // we have to bail out.
+ if (SkipFirstBlock)
+ return true;
+
+ for (NonLocalDepInfo::reverse_iterator I = Cache->rbegin(); ; ++I) {
+ assert(I != Cache->rend() && "Didn't find current block??");
+ if (I->getBB() != BB)
+ continue;
+
+ assert(I->getResult().isNonLocal() &&
+ "Should only be here with transparent block");
+ I->setResult(MemDepResult::getUnknown());
+ Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(),
+ Pointer.getAddr()));
+ break;
+ }
}
+
+ // Okay, we're done now. If we added new values to the cache, re-sort it.
+ SortNonLocalDepInfoCache(*Cache, NumSortedEntries);
+ DEBUG(AssertSorted(*Cache));
+ return false;
+}
+
+/// RemoveCachedNonLocalPointerDependencies - If P exists in
+/// CachedNonLocalPointerInfo, remove it.
+void MemoryDependenceAnalysis::
+RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P) {
+ CachedNonLocalPointerInfo::iterator It =
+ NonLocalPointerDeps.find(P);
+ if (It == NonLocalPointerDeps.end()) return;
+ // Remove all of the entries in the BB->val map. This involves removing
+ // instructions from the reverse map.
+ NonLocalDepInfo &PInfo = It->second.NonLocalDeps;
- // Copy the result into the output set.
- for (NonLocalDepInfo::iterator I = Cache.begin(), E = Cache.end(); I != E;++I)
- Result.push_back(std::make_pair(I->first, ConvToResult(I->second)));
+ for (unsigned i = 0, e = PInfo.size(); i != e; ++i) {
+ Instruction *Target = PInfo[i].getResult().getInst();
+ if (Target == 0) continue; // Ignore non-local dep results.
+ assert(Target->getParent() == PInfo[i].getBB());
+
+ // Eliminating the dirty entry from 'Cache', so update the reverse info.
+ RemoveFromReverseMap(ReverseNonLocalPtrDeps, Target, P);
+ }
+
+ // Remove P from NonLocalPointerDeps (which deletes NonLocalDepInfo).
+ NonLocalPointerDeps.erase(It);
+}
+
+
+/// invalidateCachedPointerInfo - This method is used to invalidate cached
+/// information about the specified pointer, because it may be too
+/// conservative in memdep. This is an optional call that can be used when
+/// the client detects an equivalence between the pointer and some other
+/// value and replaces the other value with ptr. This can make Ptr available
+/// in more places that cached info does not necessarily keep.
+void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) {
+ // If Ptr isn't really a pointer, just ignore it.
+ if (!Ptr->getType()->isPointerTy()) return;
+ // Flush store info for the pointer.
+ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false));
+ // Flush load info for the pointer.
+ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true));
+}
+
+/// invalidateCachedPredecessors - Clear the PredIteratorCache info.
+/// This needs to be done when the CFG changes, e.g., due to splitting
+/// critical edges.
+void MemoryDependenceAnalysis::invalidateCachedPredecessors() {
+ PredCache->clear();
}
/// removeInstruction - Remove an instruction from the dependence analysis,
// for any cached queries.
NonLocalDepMapType::iterator NLDI = NonLocalDeps.find(RemInst);
if (NLDI != NonLocalDeps.end()) {
- NonLocalDepInfo &BlockMap = *NLDI->second;
+ NonLocalDepInfo &BlockMap = NLDI->second.first;
for (NonLocalDepInfo::iterator DI = BlockMap.begin(), DE = BlockMap.end();
DI != DE; ++DI)
- if (Instruction *Inst = DI->second.getPointer())
- ReverseNonLocalDeps[Inst].erase(RemInst);
- delete &BlockMap;
+ if (Instruction *Inst = DI->getResult().getInst())
+ RemoveFromReverseMap(ReverseNonLocalDeps, Inst, RemInst);
NonLocalDeps.erase(NLDI);
}
LocalDepMapType::iterator LocalDepEntry = LocalDeps.find(RemInst);
if (LocalDepEntry != LocalDeps.end()) {
// Remove us from DepInst's reverse set now that the local dep info is gone.
- if (Instruction *Inst = LocalDepEntry->second.getPointer()) {
- SmallPtrSet<Instruction*, 4> &RLD = ReverseLocalDeps[Inst];
- RLD.erase(RemInst);
- if (RLD.empty())
- ReverseLocalDeps.erase(Inst);
- }
+ if (Instruction *Inst = LocalDepEntry->second.getInst())
+ RemoveFromReverseMap(ReverseLocalDeps, Inst, RemInst);
// Remove this local dependency info.
LocalDeps.erase(LocalDepEntry);
- }
+ }
+
+ // If we have any cached pointer dependencies on this instruction, remove
+ // them. If the instruction has non-pointer type, then it can't be a pointer
+ // base.
+
+ // Remove it from both the load info and the store info. The instruction
+ // can't be in either of these maps if it is non-pointer.
+ if (RemInst->getType()->isPointerTy()) {
+ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false));
+ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true));
+ }
// Loop over all of the things that depend on the instruction we're removing.
//
SmallVector<std::pair<Instruction*, Instruction*>, 8> ReverseDepsToAdd;
+
+ // If we find RemInst as a clobber or Def in any of the maps for other values,
+ // we need to replace its entry with a dirty version of the instruction after
+ // it. If RemInst is a terminator, we use a null dirty value.
+ //
+ // Using a dirty version of the instruction after RemInst saves having to scan
+ // the entire block to get to this point.
+ MemDepResult NewDirtyVal;
+ if (!RemInst->isTerminator())
+ NewDirtyVal = MemDepResult::getDirty(++BasicBlock::iterator(RemInst));
ReverseDepMapType::iterator ReverseDepIt = ReverseLocalDeps.find(RemInst);
if (ReverseDepIt != ReverseLocalDeps.end()) {
SmallPtrSet<Instruction*, 4> &ReverseDeps = ReverseDepIt->second;
- // RemInst can't be the terminator if it has stuff depending on it.
+ // RemInst can't be the terminator if it has local stuff depending on it.
assert(!ReverseDeps.empty() && !isa<TerminatorInst>(RemInst) &&
"Nothing can locally depend on a terminator");
- // Anything that was locally dependent on RemInst is now going to be
- // dependent on the instruction after RemInst. It will have the dirty flag
- // set so it will rescan. This saves having to scan the entire block to get
- // to this point.
- Instruction *NewDepInst = next(BasicBlock::iterator(RemInst));
-
for (SmallPtrSet<Instruction*, 4>::iterator I = ReverseDeps.begin(),
E = ReverseDeps.end(); I != E; ++I) {
Instruction *InstDependingOnRemInst = *I;
assert(InstDependingOnRemInst != RemInst &&
"Already removed our local dep info");
- LocalDeps[InstDependingOnRemInst] = DepResultTy(NewDepInst, Dirty);
+ LocalDeps[InstDependingOnRemInst] = NewDirtyVal;
// Make sure to remember that new things depend on NewDepInst.
- ReverseDepsToAdd.push_back(std::make_pair(NewDepInst,
+ assert(NewDirtyVal.getInst() && "There is no way something else can have "
+ "a local dep on this if it is a terminator!");
+ ReverseDepsToAdd.push_back(std::make_pair(NewDirtyVal.getInst(),
InstDependingOnRemInst));
}
ReverseDepIt = ReverseNonLocalDeps.find(RemInst);
if (ReverseDepIt != ReverseNonLocalDeps.end()) {
- SmallPtrSet<Instruction*, 4>& set = ReverseDepIt->second;
- for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end();
+ SmallPtrSet<Instruction*, 4> &Set = ReverseDepIt->second;
+ for (SmallPtrSet<Instruction*, 4>::iterator I = Set.begin(), E = Set.end();
I != E; ++I) {
assert(*I != RemInst && "Already removed NonLocalDep info for RemInst");
- NonLocalDepInfo &INLD = *NonLocalDeps[*I];
- assert(&INLD != 0 && "Reverse mapping out of date?");
+ PerInstNLInfo &INLD = NonLocalDeps[*I];
+ // The information is now dirty!
+ INLD.second = true;
- for (NonLocalDepInfo::iterator DI = INLD.begin(), DE = INLD.end();
- DI != DE; ++DI) {
- if (DI->second.getPointer() != RemInst) continue;
+ for (NonLocalDepInfo::iterator DI = INLD.first.begin(),
+ DE = INLD.first.end(); DI != DE; ++DI) {
+ if (DI->getResult().getInst() != RemInst) continue;
// Convert to a dirty entry for the subsequent instruction.
- DI->second.setInt(Dirty);
- if (RemInst->isTerminator())
- DI->second.setPointer(0);
- else {
- Instruction *NextI = next(BasicBlock::iterator(RemInst));
- DI->second.setPointer(NextI);
+ DI->setResult(NewDirtyVal);
+
+ if (Instruction *NextI = NewDirtyVal.getInst())
ReverseDepsToAdd.push_back(std::make_pair(NextI, *I));
- }
}
}
}
}
+ // If the instruction is in ReverseNonLocalPtrDeps then it appears as a
+ // value in the NonLocalPointerDeps info.
+ ReverseNonLocalPtrDepTy::iterator ReversePtrDepIt =
+ ReverseNonLocalPtrDeps.find(RemInst);
+ if (ReversePtrDepIt != ReverseNonLocalPtrDeps.end()) {
+ SmallPtrSet<ValueIsLoadPair, 4> &Set = ReversePtrDepIt->second;
+ SmallVector<std::pair<Instruction*, ValueIsLoadPair>,8> ReversePtrDepsToAdd;
+
+ for (SmallPtrSet<ValueIsLoadPair, 4>::iterator I = Set.begin(),
+ E = Set.end(); I != E; ++I) {
+ ValueIsLoadPair P = *I;
+ assert(P.getPointer() != RemInst &&
+ "Already removed NonLocalPointerDeps info for RemInst");
+
+ NonLocalDepInfo &NLPDI = NonLocalPointerDeps[P].NonLocalDeps;
+
+ // The cache is not valid for any specific block anymore.
+ NonLocalPointerDeps[P].Pair = BBSkipFirstBlockPair();
+
+ // Update any entries for RemInst to use the instruction after it.
+ for (NonLocalDepInfo::iterator DI = NLPDI.begin(), DE = NLPDI.end();
+ DI != DE; ++DI) {
+ if (DI->getResult().getInst() != RemInst) continue;
+
+ // Convert to a dirty entry for the subsequent instruction.
+ DI->setResult(NewDirtyVal);
+
+ if (Instruction *NewDirtyInst = NewDirtyVal.getInst())
+ ReversePtrDepsToAdd.push_back(std::make_pair(NewDirtyInst, P));
+ }
+
+ // Re-sort the NonLocalDepInfo. Changing the dirty entry to its
+ // subsequent value may invalidate the sortedness.
+ std::sort(NLPDI.begin(), NLPDI.end());
+ }
+
+ ReverseNonLocalPtrDeps.erase(ReversePtrDepIt);
+
+ while (!ReversePtrDepsToAdd.empty()) {
+ ReverseNonLocalPtrDeps[ReversePtrDepsToAdd.back().first]
+ .insert(ReversePtrDepsToAdd.back().second);
+ ReversePtrDepsToAdd.pop_back();
+ }
+ }
+
+
assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?");
- getAnalysis<AliasAnalysis>().deleteValue(RemInst);
+ AA->deleteValue(RemInst);
DEBUG(verifyRemoved(RemInst));
}
-
/// verifyRemoved - Verify that the specified instruction does not occur
/// in our internal data structures.
void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const {
for (LocalDepMapType::const_iterator I = LocalDeps.begin(),
E = LocalDeps.end(); I != E; ++I) {
assert(I->first != D && "Inst occurs in data structures");
- assert(I->second.getPointer() != D &&
+ assert(I->second.getInst() != D &&
"Inst occurs in data structures");
}
+ for (CachedNonLocalPointerInfo::const_iterator I =NonLocalPointerDeps.begin(),
+ E = NonLocalPointerDeps.end(); I != E; ++I) {
+ assert(I->first.getPointer() != D && "Inst occurs in NLPD map key");
+ const NonLocalDepInfo &Val = I->second.NonLocalDeps;
+ for (NonLocalDepInfo::const_iterator II = Val.begin(), E = Val.end();
+ II != E; ++II)
+ assert(II->getResult().getInst() != D && "Inst occurs as NLPD value");
+ }
+
for (NonLocalDepMapType::const_iterator I = NonLocalDeps.begin(),
E = NonLocalDeps.end(); I != E; ++I) {
assert(I->first != D && "Inst occurs in data structures");
- NonLocalDepInfo &INLD = *I->second;
- for (NonLocalDepInfo::iterator II = INLD.begin(), EE = INLD.end();
- II != EE; ++II)
- assert(II->second.getPointer() != D && "Inst occurs in data structures");
+ const PerInstNLInfo &INLD = I->second;
+ for (NonLocalDepInfo::const_iterator II = INLD.first.begin(),
+ EE = INLD.first.end(); II != EE; ++II)
+ assert(II->getResult().getInst() != D && "Inst occurs in data structures");
}
for (ReverseDepMapType::const_iterator I = ReverseLocalDeps.begin(),
EE = I->second.end(); II != EE; ++II)
assert(*II != D && "Inst occurs in data structures");
}
+
+ for (ReverseNonLocalPtrDepTy::const_iterator
+ I = ReverseNonLocalPtrDeps.begin(),
+ E = ReverseNonLocalPtrDeps.end(); I != E; ++I) {
+ assert(I->first != D && "Inst occurs in rev NLPD map");
+
+ for (SmallPtrSet<ValueIsLoadPair, 4>::const_iterator II = I->second.begin(),
+ E = I->second.end(); II != E; ++II)
+ assert(*II != ValueIsLoadPair(D, false) &&
+ *II != ValueIsLoadPair(D, true) &&
+ "Inst occurs in ReverseNonLocalPtrDeps map");
+ }
+
}
projects / oota-llvm.git / blobdiff