X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FAnalysis%2FMemoryDependenceAnalysis.cpp;h=6918360536a300b58ccdb8dca5e5dc6676092348;hp=c0009cb9899f7f50ab737de16b374ffb6cb3f37e;hb=1aeaf6cd6373dbf67d3728de0b9f4d2725571b67;hpb=8b9dc21d6f12a0251cdb6116c2297c13d77073d5 diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp index c0009cb9899..6918360536a 100644 --- a/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -1,4 +1,4 @@ -//===- MemoryDependenceAnalysis.cpp - Mem Deps Implementation --*- C++ -*-===// +//===- MemoryDependenceAnalysis.cpp - Mem Deps Implementation -------------===// // // The LLVM Compiler Infrastructure // @@ -14,25 +14,29 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "memdep" #include "llvm/Analysis/MemoryDependenceAnalysis.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AliasAnalysis.h" -#include "llvm/Analysis/Dominators.h" +#include "llvm/Analysis/AssumptionCache.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/MemoryBuiltins.h" #include "llvm/Analysis/PHITransAddr.h" +#include "llvm/Analysis/OrderedBasicBlock.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/IR/DataLayout.h" +#include "llvm/IR/Dominators.h" #include "llvm/IR/Function.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/LLVMContext.h" +#include "llvm/IR/PredIteratorCache.h" #include "llvm/Support/Debug.h" -#include "llvm/Support/PredIteratorCache.h" using namespace llvm; +#define DEBUG_TYPE "memdep" + 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"); @@ -47,19 +51,28 @@ STATISTIC(NumCacheCompleteNonLocalPtr, "Number of block queries that were completely cached"); // Limit for the number of instructions to scan in a block. -static const int BlockScanLimit = 100; + +static cl::opt BlockScanLimit( + "memdep-block-scan-limit", cl::Hidden, cl::init(100), + cl::desc("The number of instructions to scan in a block in memory " + "dependency analysis (default = 100)")); + +// Limit on the number of memdep results to process. +static const unsigned int NumResultsLimit = 100; char MemoryDependenceAnalysis::ID = 0; // Register this pass... INITIALIZE_PASS_BEGIN(MemoryDependenceAnalysis, "memdep", "Memory Dependence Analysis", false, true) -INITIALIZE_AG_DEPENDENCY(AliasAnalysis) +INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker) +INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass) +INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass) INITIALIZE_PASS_END(MemoryDependenceAnalysis, "memdep", "Memory Dependence Analysis", false, true) MemoryDependenceAnalysis::MemoryDependenceAnalysis() -: FunctionPass(ID), PredCache(0) { + : FunctionPass(ID) { initializeMemoryDependenceAnalysisPass(*PassRegistry::getPassRegistry()); } MemoryDependenceAnalysis::~MemoryDependenceAnalysis() { @@ -73,24 +86,25 @@ void MemoryDependenceAnalysis::releaseMemory() { ReverseLocalDeps.clear(); ReverseNonLocalDeps.clear(); ReverseNonLocalPtrDeps.clear(); - PredCache->clear(); + PredCache.clear(); } - - /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis. /// void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesAll(); - AU.addRequiredTransitive(); + AU.addRequired(); + AU.addRequiredTransitive(); + AU.addRequiredTransitive(); } -bool MemoryDependenceAnalysis::runOnFunction(Function &) { - AA = &getAnalysis(); - TD = getAnalysisIfAvailable(); - DT = getAnalysisIfAvailable(); - if (PredCache == 0) - PredCache.reset(new PredIteratorCache()); +bool MemoryDependenceAnalysis::runOnFunction(Function &F) { + AA = &getAnalysis().getAAResults(); + AC = &getAnalysis().getAssumptionCache(F); + DominatorTreeWrapperPass *DTWP = + getAnalysisIfAvailable(); + DT = DTWP ? &DTWP->getDomTree() : nullptr; + TLI = &getAnalysis().getTLI(); return false; } @@ -113,77 +127,78 @@ static void RemoveFromReverseMap(DenseMap(Inst)) { if (LI->isUnordered()) { - Loc = AA->getLocation(LI); - return AliasAnalysis::Ref; + Loc = MemoryLocation::get(LI); + return MRI_Ref; } if (LI->getOrdering() == Monotonic) { - Loc = AA->getLocation(LI); - return AliasAnalysis::ModRef; + Loc = MemoryLocation::get(LI); + return MRI_ModRef; } - Loc = AliasAnalysis::Location(); - return AliasAnalysis::ModRef; + Loc = MemoryLocation(); + return MRI_ModRef; } if (const StoreInst *SI = dyn_cast(Inst)) { if (SI->isUnordered()) { - Loc = AA->getLocation(SI); - return AliasAnalysis::Mod; + Loc = MemoryLocation::get(SI); + return MRI_Mod; } if (SI->getOrdering() == Monotonic) { - Loc = AA->getLocation(SI); - return AliasAnalysis::ModRef; + Loc = MemoryLocation::get(SI); + return MRI_ModRef; } - Loc = AliasAnalysis::Location(); - return AliasAnalysis::ModRef; + Loc = MemoryLocation(); + return MRI_ModRef; } if (const VAArgInst *V = dyn_cast(Inst)) { - Loc = AA->getLocation(V); - return AliasAnalysis::ModRef; + Loc = MemoryLocation::get(V); + return MRI_ModRef; } - if (const CallInst *CI = isFreeCall(Inst, AA->getTargetLibraryInfo())) { + if (const CallInst *CI = isFreeCall(Inst, &TLI)) { // calls to free() deallocate the entire structure - Loc = AliasAnalysis::Location(CI->getArgOperand(0)); - return AliasAnalysis::Mod; + Loc = MemoryLocation(CI->getArgOperand(0)); + return MRI_Mod; } - if (const IntrinsicInst *II = dyn_cast(Inst)) + if (const IntrinsicInst *II = dyn_cast(Inst)) { + AAMDNodes AAInfo; + switch (II->getIntrinsicID()) { case Intrinsic::lifetime_start: case Intrinsic::lifetime_end: case Intrinsic::invariant_start: - Loc = AliasAnalysis::Location(II->getArgOperand(1), - cast(II->getArgOperand(0)) - ->getZExtValue(), - II->getMetadata(LLVMContext::MD_tbaa)); + II->getAAMetadata(AAInfo); + Loc = MemoryLocation( + II->getArgOperand(1), + cast(II->getArgOperand(0))->getZExtValue(), AAInfo); // These intrinsics don't really modify the memory, but returning Mod // will allow them to be handled conservatively. - return AliasAnalysis::Mod; + return MRI_Mod; case Intrinsic::invariant_end: - Loc = AliasAnalysis::Location(II->getArgOperand(2), - cast(II->getArgOperand(1)) - ->getZExtValue(), - II->getMetadata(LLVMContext::MD_tbaa)); + II->getAAMetadata(AAInfo); + Loc = MemoryLocation( + II->getArgOperand(2), + cast(II->getArgOperand(1))->getZExtValue(), AAInfo); // These intrinsics don't really modify the memory, but returning Mod // will allow them to be handled conservatively. - return AliasAnalysis::Mod; + return MRI_Mod; default: break; } + } // Otherwise, just do the coarse-grained thing that always works. if (Inst->mayWriteToMemory()) - return AliasAnalysis::ModRef; + return MRI_ModRef; if (Inst->mayReadFromMemory()) - return AliasAnalysis::Ref; - return AliasAnalysis::NoModRef; + return MRI_Ref; + return MRI_NoModRef; } /// getCallSiteDependencyFrom - Private helper for finding the local @@ -201,27 +216,27 @@ getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall, if (!Limit) return MemDepResult::getUnknown(); - Instruction *Inst = --ScanIt; + Instruction *Inst = &*--ScanIt; // If this inst is a memory op, get the pointer it accessed - AliasAnalysis::Location Loc; - AliasAnalysis::ModRefResult MR = GetLocation(Inst, Loc, AA); + MemoryLocation Loc; + ModRefInfo MR = GetLocation(Inst, Loc, *TLI); if (Loc.Ptr) { // A simple instruction. - if (AA->getModRefInfo(CS, Loc) != AliasAnalysis::NoModRef) + if (AA->getModRefInfo(CS, Loc) != MRI_NoModRef) return MemDepResult::getClobber(Inst); continue; } - if (CallSite InstCS = cast(Inst)) { + if (auto InstCS = CallSite(Inst)) { // Debug intrinsics don't cause dependences. if (isa(Inst)) continue; // If these two calls do not interfere, look past it. switch (AA->getModRefInfo(CS, InstCS)) { - case AliasAnalysis::NoModRef: + case MRI_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) && + if (isReadOnlyCall && !(MR & MRI_Mod) && CS.getInstruction()->isIdenticalToWhenDefined(Inst)) return MemDepResult::getDef(Inst); @@ -235,7 +250,7 @@ getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall, // 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) + if (MR != MRI_NoModRef) return MemDepResult::getClobber(Inst); } @@ -251,22 +266,18 @@ getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall, /// /// 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; +static bool isLoadLoadClobberIfExtendedToFullWidth(const MemoryLocation &MemLoc, + const Value *&MemLocBase, + int64_t &MemLocOffs, + const LoadInst *LI) { + const DataLayout &DL = LI->getModule()->getDataLayout(); // If we haven't already computed the base/offset of MemLoc, do so now. - if (MemLocBase == 0) - MemLocBase = GetPointerBaseWithConstantOffset(MemLoc.Ptr, MemLocOffs, TD); + if (!MemLocBase) + MemLocBase = GetPointerBaseWithConstantOffset(MemLoc.Ptr, MemLocOffs, DL); - unsigned Size = MemoryDependenceAnalysis:: - getLoadLoadClobberFullWidthSize(MemLocBase, MemLocOffs, MemLoc.Size, - LI, *TD); + unsigned Size = MemoryDependenceAnalysis::getLoadLoadClobberFullWidthSize( + MemLocBase, MemLocOffs, MemLoc.Size, LI); return Size != 0; } @@ -277,23 +288,23 @@ isLoadLoadClobberIfExtendedToFullWidth(const AliasAnalysis::Location &MemLoc, /// 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) { +unsigned MemoryDependenceAnalysis::getLoadLoadClobberFullWidthSize( + const Value *MemLocBase, int64_t MemLocOffs, unsigned MemLocSize, + const LoadInst *LI) { // We can only extend simple integer loads. if (!isa(LI->getType()) || !LI->isSimple()) return 0; // Load widening is hostile to ThreadSanitizer: it may cause false positives // or make the reports more cryptic (access sizes are wrong). - if (LI->getParent()->getParent()->getAttributes(). - hasAttribute(AttributeSet::FunctionIndex, Attribute::SanitizeThread)) + if (LI->getParent()->getParent()->hasFnAttribute(Attribute::SanitizeThread)) return 0; + const DataLayout &DL = LI->getModule()->getDataLayout(); + // Get the base of this load. int64_t LIOffs = 0; const Value *LIBase = - GetPointerBaseWithConstantOffset(LI->getPointerOperand(), LIOffs, &TD); + GetPointerBaseWithConstantOffset(LI->getPointerOperand(), LIOffs, DL); // If the two pointers are not based on the same pointer, we can't tell that // they are related. @@ -329,12 +340,12 @@ getLoadLoadClobberFullWidthSize(const Value *MemLocBase, int64_t MemLocOffs, // 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)) + !DL.fitsInLegalInteger(NewLoadByteSize*8)) return 0; - if (LIOffs+NewLoadByteSize > MemLocEnd && - LI->getParent()->getParent()->getAttributes(). - hasAttribute(AttributeSet::FunctionIndex, Attribute::SanitizeAddress)) + if (LIOffs + NewLoadByteSize > MemLocEnd && + LI->getParent()->getParent()->hasFnAttribute( + Attribute::SanitizeAddress)) // 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. @@ -348,41 +359,162 @@ getLoadLoadClobberFullWidthSize(const Value *MemLocBase, int64_t MemLocOffs, } } +static bool isVolatile(Instruction *Inst) { + if (LoadInst *LI = dyn_cast(Inst)) + return LI->isVolatile(); + else if (StoreInst *SI = dyn_cast(Inst)) + return SI->isVolatile(); + else if (AtomicCmpXchgInst *AI = dyn_cast(Inst)) + return AI->isVolatile(); + return false; +} + + /// 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. If possible, pass the query /// instruction as well; this function may take advantage of the metadata /// annotated to the query instruction to refine the result. -MemDepResult MemoryDependenceAnalysis:: -getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, - BasicBlock::iterator ScanIt, BasicBlock *BB, - Instruction *QueryInst) { +MemDepResult MemoryDependenceAnalysis::getPointerDependencyFrom( + const MemoryLocation &MemLoc, bool isLoad, BasicBlock::iterator ScanIt, + BasicBlock *BB, Instruction *QueryInst) { + + if (QueryInst != nullptr) { + if (auto *LI = dyn_cast(QueryInst)) { + MemDepResult invariantGroupDependency = + getInvariantGroupPointerDependency(LI, BB); + + if (invariantGroupDependency.isDef()) + return invariantGroupDependency; + } + } + return getSimplePointerDependencyFrom(MemLoc, isLoad, ScanIt, BB, QueryInst); +} + +MemDepResult +MemoryDependenceAnalysis::getInvariantGroupPointerDependency(LoadInst *LI, + BasicBlock *BB) { + Value *LoadOperand = LI->getPointerOperand(); + // It's is not safe to walk the use list of global value, because function + // passes aren't allowed to look outside their functions. + if (isa(LoadOperand)) + return MemDepResult::getUnknown(); + + auto *InvariantGroupMD = LI->getMetadata(LLVMContext::MD_invariant_group); + if (!InvariantGroupMD) + return MemDepResult::getUnknown(); + + MemDepResult Result = MemDepResult::getUnknown(); + llvm::SmallSet Seen; + // Queue to process all pointers that are equivalent to load operand. + llvm::SmallVector LoadOperandsQueue; + LoadOperandsQueue.push_back(LoadOperand); + while (!LoadOperandsQueue.empty()) { + Value *Ptr = LoadOperandsQueue.pop_back_val(); + if (isa(Ptr)) + continue; + + if (auto *BCI = dyn_cast(Ptr)) { + if (!Seen.count(BCI->getOperand(0))) { + LoadOperandsQueue.push_back(BCI->getOperand(0)); + Seen.insert(BCI->getOperand(0)); + } + } + + for (Use &Us : Ptr->uses()) { + auto *U = dyn_cast(Us.getUser()); + if (!U || U == LI || !DT->dominates(U, LI)) + continue; - const Value *MemLocBase = 0; + if (auto *BCI = dyn_cast(U)) { + if (!Seen.count(BCI)) { + LoadOperandsQueue.push_back(BCI); + Seen.insert(BCI); + } + continue; + } + // If we hit load/store with the same invariant.group metadata (and the + // same pointer operand) we can assume that value pointed by pointer + // operand didn't change. + if ((isa(U) || isa(U)) && U->getParent() == BB && + U->getMetadata(LLVMContext::MD_invariant_group) == InvariantGroupMD) + return MemDepResult::getDef(U); + } + } + return Result; +} + +MemDepResult MemoryDependenceAnalysis::getSimplePointerDependencyFrom( + const MemoryLocation &MemLoc, bool isLoad, BasicBlock::iterator ScanIt, + BasicBlock *BB, Instruction *QueryInst) { + + const Value *MemLocBase = nullptr; int64_t MemLocOffset = 0; unsigned Limit = BlockScanLimit; bool isInvariantLoad = false; + + // We must be careful with atomic accesses, as they may allow another thread + // to touch this location, cloberring it. We are conservative: if the + // QueryInst is not a simple (non-atomic) memory access, we automatically + // return getClobber. + // If it is simple, we know based on the results of + // "Compiler testing via a theory of sound optimisations in the C11/C++11 + // memory model" in PLDI 2013, that a non-atomic location can only be + // clobbered between a pair of a release and an acquire action, with no + // access to the location in between. + // Here is an example for giving the general intuition behind this rule. + // In the following code: + // store x 0; + // release action; [1] + // acquire action; [4] + // %val = load x; + // It is unsafe to replace %val by 0 because another thread may be running: + // acquire action; [2] + // store x 42; + // release action; [3] + // with synchronization from 1 to 2 and from 3 to 4, resulting in %val + // being 42. A key property of this program however is that if either + // 1 or 4 were missing, there would be a race between the store of 42 + // either the store of 0 or the load (making the whole progam racy). + // The paper mentioned above shows that the same property is respected + // by every program that can detect any optimisation of that kind: either + // it is racy (undefined) or there is a release followed by an acquire + // between the pair of accesses under consideration. + + // If the load is invariant, we "know" that it doesn't alias *any* write. We + // do want to respect mustalias results since defs are useful for value + // forwarding, but any mayalias write can be assumed to be noalias. + // Arguably, this logic should be pushed inside AliasAnalysis itself. if (isLoad && QueryInst) { LoadInst *LI = dyn_cast(QueryInst); - if (LI && LI->getMetadata(LLVMContext::MD_invariant_load) != 0) + if (LI && LI->getMetadata(LLVMContext::MD_invariant_load) != nullptr) isInvariantLoad = true; } + const DataLayout &DL = BB->getModule()->getDataLayout(); + + // Create a numbered basic block to lazily compute and cache instruction + // positions inside a BB. This is used to provide fast queries for relative + // position between two instructions in a BB and can be used by + // AliasAnalysis::callCapturesBefore. + OrderedBasicBlock OBB(BB); + // Walk backwards through the basic block, looking for dependencies. while (ScanIt != BB->begin()) { + Instruction *Inst = &*--ScanIt; + + if (IntrinsicInst *II = dyn_cast(Inst)) + // Debug intrinsics don't (and can't) cause dependencies. + if (isa(II)) continue; + // 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 (IntrinsicInst *II = dyn_cast(Inst)) { - // Debug intrinsics don't (and can't) cause dependences. - if (isa(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) { @@ -390,8 +522,7 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, // 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)) + if (AA->isMustAlias(MemoryLocation(II->getArgOperand(1)), MemLoc)) return MemDepResult::getDef(II); continue; } @@ -399,36 +530,67 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, // 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. + // One exception is atomic loads: a value can depend on an atomic load that it + // does not alias with when this atomic load indicates that another thread may + // be accessing the location. if (LoadInst *LI = dyn_cast(Inst)) { + + // While volatile access cannot be eliminated, they do not have to clobber + // non-aliasing locations, as normal accesses, for example, can be safely + // reordered with volatile accesses. + if (LI->isVolatile()) { + if (!QueryInst) + // Original QueryInst *may* be volatile + return MemDepResult::getClobber(LI); + if (isVolatile(QueryInst)) + // Ordering required if QueryInst is itself volatile + return MemDepResult::getClobber(LI); + // Otherwise, volatile doesn't imply any special ordering + } + // Atomic loads have complications involved. + // A Monotonic (or higher) load is OK if the query inst is itself not atomic. // FIXME: This is overly conservative. - if (!LI->isUnordered()) - return MemDepResult::getClobber(LI); + if (LI->isAtomic() && LI->getOrdering() > Unordered) { + if (!QueryInst) + return MemDepResult::getClobber(LI); + if (LI->getOrdering() != Monotonic) + return MemDepResult::getClobber(LI); + if (auto *QueryLI = dyn_cast(QueryInst)) { + if (!QueryLI->isSimple()) + return MemDepResult::getClobber(LI); + } else if (auto *QuerySI = dyn_cast(QueryInst)) { + if (!QuerySI->isSimple()) + return MemDepResult::getClobber(LI); + } else if (QueryInst->mayReadOrWriteMemory()) { + return MemDepResult::getClobber(LI); + } + } - AliasAnalysis::Location LoadLoc = AA->getLocation(LI); + MemoryLocation LoadLoc = MemoryLocation::get(LI); // If we found a pointer, check if it could be the same as our pointer. - AliasAnalysis::AliasResult R = AA->alias(LoadLoc, MemLoc); + AliasResult R = AA->alias(LoadLoc, MemLoc); if (isLoad) { - if (R == AliasAnalysis::NoAlias) { + if (R == 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(LI->getType())) - if (LI->getAlignment()*8 > ITy->getPrimitiveSizeInBits() && + if (IntegerType *ITy = dyn_cast(LI->getType())) { + if (LI->getAlignment() * 8 > ITy->getPrimitiveSizeInBits() && isLoadLoadClobberIfExtendedToFullWidth(MemLoc, MemLocBase, - MemLocOffset, LI, TD)) + MemLocOffset, LI)) return MemDepResult::getClobber(Inst); - + } continue; } // Must aliased loads are defs of each other. - if (R == AliasAnalysis::MustAlias) + if (R == MustAlias) return MemDepResult::getDef(Inst); #if 0 // FIXME: Temporarily disabled. GVN is cleverly rewriting loads @@ -438,7 +600,7 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, // If we have a partial alias, then return this as a clobber for the // client to handle. - if (R == AliasAnalysis::PartialAlias) + if (R == PartialAlias) return MemDepResult::getClobber(Inst); #endif @@ -448,7 +610,7 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, } // Stores don't depend on other no-aliased accesses. - if (R == AliasAnalysis::NoAlias) + if (R == NoAlias) continue; // Stores don't alias loads from read-only memory. @@ -461,26 +623,47 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, if (StoreInst *SI = dyn_cast(Inst)) { // Atomic stores have complications involved. + // A Monotonic store is OK if the query inst is itself not atomic. // FIXME: This is overly conservative. - if (!SI->isUnordered()) + if (!SI->isUnordered()) { + if (!QueryInst) + return MemDepResult::getClobber(SI); + if (SI->getOrdering() != Monotonic) + return MemDepResult::getClobber(SI); + if (auto *QueryLI = dyn_cast(QueryInst)) { + if (!QueryLI->isSimple()) + return MemDepResult::getClobber(SI); + } else if (auto *QuerySI = dyn_cast(QueryInst)) { + if (!QuerySI->isSimple()) + return MemDepResult::getClobber(SI); + } else if (QueryInst->mayReadOrWriteMemory()) { + return MemDepResult::getClobber(SI); + } + } + + // FIXME: this is overly conservative. + // While volatile access cannot be eliminated, they do not have to clobber + // non-aliasing locations, as normal accesses can for example be reordered + // with volatile accesses. + if (SI->isVolatile()) 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) + if (AA->getModRefInfo(SI, MemLoc) == MRI_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); + MemoryLocation StoreLoc = MemoryLocation::get(SI); // If we found a pointer, check if it could be the same as our pointer. - AliasAnalysis::AliasResult R = AA->alias(StoreLoc, MemLoc); + AliasResult R = AA->alias(StoreLoc, MemLoc); - if (R == AliasAnalysis::NoAlias) + if (R == NoAlias) continue; - if (R == AliasAnalysis::MustAlias) + if (R == MustAlias) return MemDepResult::getDef(Inst); if (isInvariantLoad) continue; @@ -495,34 +678,38 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad, // 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(Inst) || isNoAliasFn(Inst, TLI)) { - const Value *AccessPtr = GetUnderlyingObject(MemLoc.Ptr, TD); + const Value *AccessPtr = GetUnderlyingObject(MemLoc.Ptr, DL); 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(Inst) || - isMallocLikeFn(Inst, TLI) || isCallocLikeFn(Inst, TLI)) + if (isInvariantLoad) + continue; + // Be conservative if the accessed pointer may alias the allocation - + // fallback to the generic handling below. + if ((AA->alias(Inst, AccessPtr) == NoAlias) && + // If the allocation is not aliased and does not read memory (like + // strdup), it is safe to ignore. + (isa(Inst) || isMallocLikeFn(Inst, TLI) || + isCallocLikeFn(Inst, TLI))) continue; } + if (isInvariantLoad) + continue; + // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer. - AliasAnalysis::ModRefResult MR = AA->getModRefInfo(Inst, MemLoc); + ModRefInfo MR = AA->getModRefInfo(Inst, MemLoc); // If necessary, perform additional analysis. - if (MR == AliasAnalysis::ModRef) - MR = AA->callCapturesBefore(Inst, MemLoc, DT); + if (MR == MRI_ModRef) + MR = AA->callCapturesBefore(Inst, MemLoc, DT, &OBB); switch (MR) { - case AliasAnalysis::NoModRef: + case MRI_NoModRef: // If the call has no effect on the queried pointer, just ignore it. continue; - case AliasAnalysis::Mod: + case MRI_Mod: return MemDepResult::getClobber(Inst); - case AliasAnalysis::Ref: + case MRI_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) @@ -572,21 +759,21 @@ MemDepResult MemoryDependenceAnalysis::getDependency(Instruction *QueryInst) { else LocalCache = MemDepResult::getNonFuncLocal(); } else { - AliasAnalysis::Location MemLoc; - AliasAnalysis::ModRefResult MR = GetLocation(QueryInst, MemLoc, AA); + MemoryLocation MemLoc; + ModRefInfo MR = GetLocation(QueryInst, MemLoc, *TLI); if (MemLoc.Ptr) { // If we can do a pointer scan, make it happen. - bool isLoad = !(MR & AliasAnalysis::Mod); + bool isLoad = !(MR & MRI_Mod); if (IntrinsicInst *II = dyn_cast(QueryInst)) isLoad |= II->getIntrinsicID() == Intrinsic::lifetime_start; - LocalCache = getPointerDependencyFrom(MemLoc, isLoad, ScanPos, - QueryParent, QueryInst); + LocalCache = getPointerDependencyFrom( + MemLoc, isLoad, ScanPos->getIterator(), QueryParent, QueryInst); } else if (isa(QueryInst) || isa(QueryInst)) { CallSite QueryCS(QueryInst); bool isReadOnly = AA->onlyReadsMemory(QueryCS); - LocalCache = getCallSiteDependencyFrom(QueryCS, isReadOnly, ScanPos, - QueryParent); + LocalCache = getCallSiteDependencyFrom( + QueryCS, isReadOnly, ScanPos->getIterator(), QueryParent); } else // Non-memory instruction. LocalCache = MemDepResult::getUnknown(); @@ -605,10 +792,8 @@ MemDepResult MemoryDependenceAnalysis::getDependency(Instruction *QueryInst) { 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!"); + assert(std::is_sorted(Cache.begin(), Cache.begin() + Count) && + "Cache isn't sorted!"); } #endif @@ -661,8 +846,8 @@ MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { } else { // Seed DirtyBlocks with each of the preds of QueryInst's block. BasicBlock *QueryBB = QueryCS.getInstruction()->getParent(); - for (BasicBlock **PI = PredCache->GetPreds(QueryBB); *PI; ++PI) - DirtyBlocks.push_back(*PI); + for (BasicBlock *Pred : PredCache.get(QueryBB)) + DirtyBlocks.push_back(Pred); ++NumUncacheNonLocal; } @@ -680,7 +865,7 @@ MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { DirtyBlocks.pop_back(); // Already processed this block? - if (!Visited.insert(DirtyBB)) + if (!Visited.insert(DirtyBB).second) continue; // Do a binary search to see if we already have an entry for this block in @@ -689,10 +874,10 @@ MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { NonLocalDepInfo::iterator Entry = std::upper_bound(Cache.begin(), Cache.begin()+NumSortedEntries, NonLocalDepEntry(DirtyBB)); - if (Entry != Cache.begin() && prior(Entry)->getBB() == DirtyBB) + if (Entry != Cache.begin() && std::prev(Entry)->getBB() == DirtyBB) --Entry; - NonLocalDepEntry *ExistingResult = 0; + NonLocalDepEntry *ExistingResult = nullptr; if (Entry != Cache.begin()+NumSortedEntries && Entry->getBB() == DirtyBB) { // If we already have an entry, and if it isn't already dirty, the block @@ -709,7 +894,7 @@ MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { BasicBlock::iterator ScanPos = DirtyBB->end(); if (ExistingResult) { if (Instruction *Inst = ExistingResult->getResult().getInst()) { - ScanPos = Inst; + ScanPos = Inst->getIterator(); // We're removing QueryInst's use of Inst. RemoveFromReverseMap(ReverseNonLocalDeps, Inst, QueryCS.getInstruction()); @@ -747,8 +932,8 @@ MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { // 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); + for (BasicBlock *Pred : PredCache.get(DirtyBB)) + DirtyBlocks.push_back(Pred); } } @@ -763,21 +948,48 @@ MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { /// own block. /// void MemoryDependenceAnalysis:: -getNonLocalPointerDependency(const AliasAnalysis::Location &Loc, bool isLoad, - BasicBlock *FromBB, +getNonLocalPointerDependency(Instruction *QueryInst, SmallVectorImpl &Result) { + const MemoryLocation Loc = MemoryLocation::get(QueryInst); + bool isLoad = isa(QueryInst); + BasicBlock *FromBB = QueryInst->getParent(); + assert(FromBB); + assert(Loc.Ptr->getType()->isPointerTy() && "Can't get pointer deps of a non-pointer!"); Result.clear(); - - PHITransAddr Address(const_cast(Loc.Ptr), TD); + + // This routine does not expect to deal with volatile instructions. + // Doing so would require piping through the QueryInst all the way through. + // TODO: volatiles can't be elided, but they can be reordered with other + // non-volatile accesses. + + // We currently give up on any instruction which is ordered, but we do handle + // atomic instructions which are unordered. + // TODO: Handle ordered instructions + auto isOrdered = [](Instruction *Inst) { + if (LoadInst *LI = dyn_cast(Inst)) { + return !LI->isUnordered(); + } else if (StoreInst *SI = dyn_cast(Inst)) { + return !SI->isUnordered(); + } + return false; + }; + if (isVolatile(QueryInst) || isOrdered(QueryInst)) { + Result.push_back(NonLocalDepResult(FromBB, + MemDepResult::getUnknown(), + const_cast(Loc.Ptr))); + return; + } + const DataLayout &DL = FromBB->getModule()->getDataLayout(); + PHITransAddr Address(const_cast(Loc.Ptr), DL, AC); // 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 Visited; - if (!getNonLocalPointerDepFromBB(Address, Loc, isLoad, FromBB, + if (!getNonLocalPointerDepFromBB(QueryInst, Address, Loc, isLoad, FromBB, Result, Visited, true)) return; Result.clear(); @@ -790,10 +1002,9 @@ getNonLocalPointerDependency(const AliasAnalysis::Location &Loc, bool isLoad, /// 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) { +MemDepResult MemoryDependenceAnalysis::GetNonLocalInfoForBlock( + Instruction *QueryInst, const MemoryLocation &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. @@ -803,7 +1014,7 @@ GetNonLocalInfoForBlock(const AliasAnalysis::Location &Loc, if (Entry != Cache->begin() && (Entry-1)->getBB() == BB) --Entry; - NonLocalDepEntry *ExistingResult = 0; + NonLocalDepEntry *ExistingResult = nullptr; if (Entry != Cache->begin()+NumSortedEntries && Entry->getBB() == BB) ExistingResult = &*Entry; @@ -822,17 +1033,18 @@ GetNonLocalInfoForBlock(const AliasAnalysis::Location &Loc, assert(ExistingResult->getResult().getInst()->getParent() == BB && "Instruction invalidated?"); ++NumCacheDirtyNonLocalPtr; - ScanPos = ExistingResult->getResult().getInst(); + ScanPos = ExistingResult->getResult().getInst()->getIterator(); // Eliminating the dirty entry from 'Cache', so update the reverse info. ValueIsLoadPair CacheKey(Loc.Ptr, isLoad); - RemoveFromReverseMap(ReverseNonLocalPtrDeps, ScanPos, CacheKey); + RemoveFromReverseMap(ReverseNonLocalPtrDeps, &*ScanPos, CacheKey); } else { ++NumUncacheNonLocalPtr; } // Scan the block for the dependency. - MemDepResult Dep = getPointerDependencyFrom(Loc, isLoad, ScanPos, BB); + MemDepResult Dep = getPointerDependencyFrom(Loc, isLoad, ScanPos, BB, + QueryInst); // If we had a dirty entry for the block, update it. Otherwise, just add // a new entry. @@ -856,7 +1068,7 @@ GetNonLocalInfoForBlock(const AliasAnalysis::Location &Loc, return Dep; } -/// SortNonLocalDepInfoCache - Sort the a NonLocalDepInfo cache, given a certain +/// SortNonLocalDepInfoCache - Sort the 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 @@ -904,23 +1116,21 @@ SortNonLocalDepInfoCache(MemoryDependenceAnalysis::NonLocalDepInfo &Cache, /// 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 &Result, - DenseMap &Visited, - bool SkipFirstBlock) { +bool MemoryDependenceAnalysis::getNonLocalPointerDepFromBB( + Instruction *QueryInst, const PHITransAddr &Pointer, + const MemoryLocation &Loc, bool isLoad, BasicBlock *StartBB, + SmallVectorImpl &Result, + DenseMap &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. + // aa tags are consistent with the current query. NonLocalPointerInfo InitialNLPI; InitialNLPI.Size = Loc.Size; - InitialNLPI.TBAATag = Loc.TBAATag; + InitialNLPI.AATags = Loc.AATags; // Get the NLPI for CacheKey, inserting one into the map if it doesn't // already have one. @@ -944,27 +1154,28 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, } 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, + return getNonLocalPointerDepFromBB(QueryInst, Pointer, Loc.getWithNewSize(CacheInfo->Size), isLoad, StartBB, Result, Visited, SkipFirstBlock); } - // If the query's TBAATag is inconsistent with the cached one, + // If the query's AATags are 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) { + if (CacheInfo->AATags != Loc.AATags) { + if (CacheInfo->AATags) { CacheInfo->Pair = BBSkipFirstBlockPair(); - CacheInfo->TBAATag = 0; + CacheInfo->AATags = AAMDNodes(); 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(), + if (Loc.AATags) + return getNonLocalPointerDepFromBB(QueryInst, + Pointer, Loc.getWithoutAATags(), isLoad, StartBB, Result, Visited, SkipFirstBlock); } @@ -1040,6 +1251,24 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, while (!Worklist.empty()) { BasicBlock *BB = Worklist.pop_back_val(); + // If we do process a large number of blocks it becomes very expensive and + // likely it isn't worth worrying about + if (Result.size() > NumResultsLimit) { + Worklist.clear(); + // 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); + } + // Since we bail out, 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(); + return true; + } + // Skip the first block if we have it. if (!SkipFirstBlock) { // Analyze the dependency of *Pointer in FromBB. See if we already have @@ -1049,7 +1278,8 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, // 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, + MemDepResult Dep = GetNonLocalInfoForBlock(QueryInst, + Loc, isLoad, BB, Cache, NumSortedEntries); // If we got a Def or Clobber, add this to the list of results. @@ -1073,13 +1303,13 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, if (!Pointer.NeedsPHITranslationFromBlock(BB)) { SkipFirstBlock = false; SmallVector NewBlocks; - for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) { + for (BasicBlock *Pred : PredCache.get(BB)) { // Verify that we haven't looked at this block yet. std::pair::iterator, bool> - InsertRes = Visited.insert(std::make_pair(*PI, Pointer.getAddr())); + InsertRes = Visited.insert(std::make_pair(Pred, Pointer.getAddr())); if (InsertRes.second) { // First time we've looked at *PI. - NewBlocks.push_back(*PI); + NewBlocks.push_back(Pred); continue; } @@ -1112,18 +1342,16 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, SortNonLocalDepInfoCache(*Cache, NumSortedEntries); NumSortedEntries = Cache->size(); } - Cache = 0; + Cache = nullptr; PredList.clear(); - for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) { - BasicBlock *Pred = *PI; + for (BasicBlock *Pred : PredCache.get(BB)) { 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); - + PredPointer.PHITranslateValue(BB, Pred, DT, /*MustDominate=*/false); Value *PredPtrVal = PredPointer.getAddr(); // Check to see if we have already visited this pred block with another @@ -1171,7 +1399,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, // 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) + if (!PredPtrVal) CanTranslate = false; // FIXME: it is entirely possible that PHI translating will end up with @@ -1183,7 +1411,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, // 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, + getNonLocalPointerDepFromBB(QueryInst, PredPointer, Loc.getWithNewPtr(PredPtrVal), isLoad, Pred, Result, Visited)) { @@ -1220,7 +1448,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, // for the given block. It assumes that we haven't modified any of // our datastructures while processing the current block. - if (Cache == 0) { + if (!Cache) { // Refresh the CacheInfo/Cache pointer if it got invalidated. CacheInfo = &NonLocalPointerDeps[CacheKey]; Cache = &CacheInfo->NonLocalDeps; @@ -1246,7 +1474,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, if (I->getBB() != BB) continue; - assert(I->getResult().isNonLocal() && + assert((I->getResult().isNonLocal() || !DT->isReachableFromEntry(BB)) && "Should only be here with transparent block"); I->setResult(MemDepResult::getUnknown()); Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(), @@ -1275,7 +1503,7 @@ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P) { 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. + if (!Target) continue; // Ignore non-local dep results. assert(Target->getParent() == PInfo[i].getBB()); // Eliminating the dirty entry from 'Cache', so update the reverse info. @@ -1306,7 +1534,7 @@ void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) { /// This needs to be done when the CFG changes, e.g., due to splitting /// critical edges. void MemoryDependenceAnalysis::invalidateCachedPredecessors() { - PredCache->clear(); + PredCache.clear(); } /// removeInstruction - Remove an instruction from the dependence analysis, @@ -1360,18 +1588,15 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { // the entire block to get to this point. MemDepResult NewDirtyVal; if (!RemInst->isTerminator()) - NewDirtyVal = MemDepResult::getDirty(++BasicBlock::iterator(RemInst)); + NewDirtyVal = MemDepResult::getDirty(&*++RemInst->getIterator()); ReverseDepMapType::iterator ReverseDepIt = ReverseLocalDeps.find(RemInst); if (ReverseDepIt != ReverseLocalDeps.end()) { - SmallPtrSet &ReverseDeps = ReverseDepIt->second; // RemInst can't be the terminator if it has local stuff depending on it. - assert(!ReverseDeps.empty() && !isa(RemInst) && + assert(!ReverseDepIt->second.empty() && !isa(RemInst) && "Nothing can locally depend on a terminator"); - for (SmallPtrSet::iterator I = ReverseDeps.begin(), - E = ReverseDeps.end(); I != E; ++I) { - Instruction *InstDependingOnRemInst = *I; + for (Instruction *InstDependingOnRemInst : ReverseDepIt->second) { assert(InstDependingOnRemInst != RemInst && "Already removed our local dep info"); @@ -1397,12 +1622,10 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { ReverseDepIt = ReverseNonLocalDeps.find(RemInst); if (ReverseDepIt != ReverseNonLocalDeps.end()) { - SmallPtrSet &Set = ReverseDepIt->second; - for (SmallPtrSet::iterator I = Set.begin(), E = Set.end(); - I != E; ++I) { - assert(*I != RemInst && "Already removed NonLocalDep info for RemInst"); + for (Instruction *I : ReverseDepIt->second) { + assert(I != RemInst && "Already removed NonLocalDep info for RemInst"); - PerInstNLInfo &INLD = NonLocalDeps[*I]; + PerInstNLInfo &INLD = NonLocalDeps[I]; // The information is now dirty! INLD.second = true; @@ -1414,7 +1637,7 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { DI->setResult(NewDirtyVal); if (Instruction *NextI = NewDirtyVal.getInst()) - ReverseDepsToAdd.push_back(std::make_pair(NextI, *I)); + ReverseDepsToAdd.push_back(std::make_pair(NextI, I)); } } @@ -1433,12 +1656,9 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { ReverseNonLocalPtrDepTy::iterator ReversePtrDepIt = ReverseNonLocalPtrDeps.find(RemInst); if (ReversePtrDepIt != ReverseNonLocalPtrDeps.end()) { - SmallPtrSet &Set = ReversePtrDepIt->second; SmallVector,8> ReversePtrDepsToAdd; - for (SmallPtrSet::iterator I = Set.begin(), - E = Set.end(); I != E; ++I) { - ValueIsLoadPair P = *I; + for (ValueIsLoadPair P : ReversePtrDepIt->second) { assert(P.getPointer() != RemInst && "Already removed NonLocalPointerDeps info for RemInst"); @@ -1475,12 +1695,13 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?"); - AA->deleteValue(RemInst); DEBUG(verifyRemoved(RemInst)); } /// verifyRemoved - Verify that the specified instruction does not occur -/// in our internal data structures. +/// in our internal data structures. This function verifies by asserting in +/// debug builds. void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { +#ifndef NDEBUG for (LocalDepMapType::const_iterator I = LocalDeps.begin(), E = LocalDeps.end(); I != E; ++I) { assert(I->first != D && "Inst occurs in data structures"); @@ -1509,18 +1730,16 @@ void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { for (ReverseDepMapType::const_iterator I = ReverseLocalDeps.begin(), E = ReverseLocalDeps.end(); I != E; ++I) { assert(I->first != D && "Inst occurs in data structures"); - for (SmallPtrSet::const_iterator II = I->second.begin(), - EE = I->second.end(); II != EE; ++II) - assert(*II != D && "Inst occurs in data structures"); + for (Instruction *Inst : I->second) + assert(Inst != D && "Inst occurs in data structures"); } for (ReverseDepMapType::const_iterator I = ReverseNonLocalDeps.begin(), E = ReverseNonLocalDeps.end(); I != E; ++I) { assert(I->first != D && "Inst occurs in data structures"); - for (SmallPtrSet::const_iterator II = I->second.begin(), - EE = I->second.end(); II != EE; ++II) - assert(*II != D && "Inst occurs in data structures"); + for (Instruction *Inst : I->second) + assert(Inst != D && "Inst occurs in data structures"); } for (ReverseNonLocalPtrDepTy::const_iterator @@ -1528,11 +1747,10 @@ void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { E = ReverseNonLocalPtrDeps.end(); I != E; ++I) { assert(I->first != D && "Inst occurs in rev NLPD map"); - for (SmallPtrSet::const_iterator II = I->second.begin(), - E = I->second.end(); II != E; ++II) - assert(*II != ValueIsLoadPair(D, false) && - *II != ValueIsLoadPair(D, true) && + for (ValueIsLoadPair P : I->second) + assert(P != ValueIsLoadPair(D, false) && + P != ValueIsLoadPair(D, true) && "Inst occurs in ReverseNonLocalPtrDeps map"); } - +#endif }