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Revert r255115 until we figure out how to fix the bot failures.

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llvm-svn: 255117
This commit is contained in:
Silviu Baranga
2015-12-09 15:25:28 +00:00
parent 4514a87c4d
commit ad1ccb357b
8 changed files with 164 additions and 249 deletions
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87
llvm/lib/Analysis/LoopAccessAnalysis.cpp
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@@ -87,10 +87,11 @@ Value *llvm::stripIntegerCast(Value *V) {
return V;
}
const SCEV *llvm::replaceSymbolicStrideSCEV(PredicatedScalarEvolution &PSE,
const SCEV *llvm::replaceSymbolicStrideSCEV(ScalarEvolution *SE,
const ValueToValueMap &PtrToStride,
SCEVUnionPredicate &Preds,
Value *Ptr, Value *OrigPtr) {
const SCEV *OrigSCEV = PSE.getSCEV(Ptr);
const SCEV *OrigSCEV = SE->getSCEV(Ptr);
// If there is an entry in the map return the SCEV of the pointer with the
// symbolic stride replaced by one.
@@ -107,17 +108,16 @@ const SCEV *llvm::replaceSymbolicStrideSCEV(PredicatedScalarEvolution &PSE,
ValueToValueMap RewriteMap;
RewriteMap[StrideVal] = One;
ScalarEvolution *SE = PSE.getSE();
const auto *U = cast<SCEVUnknown>(SE->getSCEV(StrideVal));
const auto *CT =
static_cast<const SCEVConstant *>(SE->getOne(StrideVal->getType()));
PSE.addPredicate(*SE->getEqualPredicate(U, CT));
auto *Expr = PSE.getSCEV(Ptr);
Preds.add(SE->getEqualPredicate(U, CT));
DEBUG(dbgs() << "LAA: Replacing SCEV: " << *OrigSCEV << " by: " << *Expr
const SCEV *ByOne = SE->rewriteUsingPredicate(OrigSCEV, Preds);
DEBUG(dbgs() << "LAA: Replacing SCEV: " << *OrigSCEV << " by: " << *ByOne
<< "\n");
return Expr;
return ByOne;
}
// Otherwise, just return the SCEV of the original pointer.
@@ -127,12 +127,11 @@ const SCEV *llvm::replaceSymbolicStrideSCEV(PredicatedScalarEvolution &PSE,
void RuntimePointerChecking::insert(Loop *Lp, Value *Ptr, bool WritePtr,
unsigned DepSetId, unsigned ASId,
const ValueToValueMap &Strides,
PredicatedScalarEvolution &PSE) {
SCEVUnionPredicate &Preds) {
// Get the stride replaced scev.
const SCEV *Sc = replaceSymbolicStrideSCEV(PSE, Strides, Ptr);
const SCEV *Sc = replaceSymbolicStrideSCEV(SE, Strides, Preds, Ptr);
const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Sc);
assert(AR && "Invalid addrec expression");
ScalarEvolution *SE = PSE.getSE();
const SCEV *Ex = SE->getBackedgeTakenCount(Lp);
const SCEV *ScStart = AR->getStart();
@@ -424,10 +423,9 @@ public:
typedef SmallPtrSet<MemAccessInfo, 8> MemAccessInfoSet;
AccessAnalysis(const DataLayout &Dl, AliasAnalysis *AA, LoopInfo *LI,
MemoryDepChecker::DepCandidates &DA,
PredicatedScalarEvolution &PSE)
MemoryDepChecker::DepCandidates &DA, SCEVUnionPredicate &Preds)
: DL(Dl), AST(*AA), LI(LI), DepCands(DA), IsRTCheckAnalysisNeeded(false),
PSE(PSE) {}
Preds(Preds) {}
/// \brief Register a load and whether it is only read from.
void addLoad(MemoryLocation &Loc, bool IsReadOnly) {
@@ -514,16 +512,16 @@ private:
bool IsRTCheckAnalysisNeeded;
/// The SCEV predicate containing all the SCEV-related assumptions.
PredicatedScalarEvolution &PSE;
SCEVUnionPredicate &Preds;
};
} // end anonymous namespace
/// \brief Check whether a pointer can participate in a runtime bounds check.
static bool hasComputableBounds(PredicatedScalarEvolution &PSE,
static bool hasComputableBounds(ScalarEvolution *SE,
const ValueToValueMap &Strides, Value *Ptr,
Loop *L) {
const SCEV *PtrScev = replaceSymbolicStrideSCEV(PSE, Strides, Ptr);
Loop *L, SCEVUnionPredicate &Preds) {
const SCEV *PtrScev = replaceSymbolicStrideSCEV(SE, Strides, Preds, Ptr);
const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PtrScev);
if (!AR)
return false;
@@ -566,11 +564,11 @@ bool AccessAnalysis::canCheckPtrAtRT(RuntimePointerChecking &RtCheck,
else
++NumReadPtrChecks;
if (hasComputableBounds(PSE, StridesMap, Ptr, TheLoop) &&
if (hasComputableBounds(SE, StridesMap, Ptr, TheLoop, Preds) &&
// When we run after a failing dependency check we have to make sure
// we don't have wrapping pointers.
(!ShouldCheckStride ||
isStridedPtr(PSE, Ptr, TheLoop, StridesMap) == 1)) {
isStridedPtr(SE, Ptr, TheLoop, StridesMap, Preds) == 1)) {
// The id of the dependence set.
unsigned DepId;
@@ -584,7 +582,7 @@ bool AccessAnalysis::canCheckPtrAtRT(RuntimePointerChecking &RtCheck,
// Each access has its own dependence set.
DepId = RunningDepId++;
RtCheck.insert(TheLoop, Ptr, IsWrite, DepId, ASId, StridesMap, PSE);
RtCheck.insert(TheLoop, Ptr, IsWrite, DepId, ASId, StridesMap, Preds);
DEBUG(dbgs() << "LAA: Found a runtime check ptr:" << *Ptr << '\n');
} else {
@@ -819,8 +817,9 @@ static bool isNoWrapAddRec(Value *Ptr, const SCEVAddRecExpr *AR,
}
/// \brief Check whether the access through \p Ptr has a constant stride.
int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
const Loop *Lp, const ValueToValueMap &StridesMap) {
int llvm::isStridedPtr(ScalarEvolution *SE, Value *Ptr, const Loop *Lp,
const ValueToValueMap &StridesMap,
SCEVUnionPredicate &Preds) {
Type *Ty = Ptr->getType();
assert(Ty->isPointerTy() && "Unexpected non-ptr");
@@ -832,7 +831,7 @@ int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
return 0;
}
const SCEV *PtrScev = replaceSymbolicStrideSCEV(PSE, StridesMap, Ptr);
const SCEV *PtrScev = replaceSymbolicStrideSCEV(SE, StridesMap, Preds, Ptr);
const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PtrScev);
if (!AR) {
@@ -855,16 +854,16 @@ int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
// to access the pointer value "0" which is undefined behavior in address
// space 0, therefore we can also vectorize this case.
bool IsInBoundsGEP = isInBoundsGep(Ptr);
bool IsNoWrapAddRec = isNoWrapAddRec(Ptr, AR, PSE.getSE(), Lp);
bool IsNoWrapAddRec = isNoWrapAddRec(Ptr, AR, SE, Lp);
bool IsInAddressSpaceZero = PtrTy->getAddressSpace() == 0;
if (!IsNoWrapAddRec && !IsInBoundsGEP && !IsInAddressSpaceZero) {
DEBUG(dbgs() << "LAA: Bad stride - Pointer may wrap in the address space "
<< *Ptr << " SCEV: " << *PtrScev << "\n");
<< *Ptr << " SCEV: " << *PtrScev << "\n");
return 0;
}
// Check the step is constant.
const SCEV *Step = AR->getStepRecurrence(*PSE.getSE());
const SCEV *Step = AR->getStepRecurrence(*SE);
// Calculate the pointer stride and check if it is constant.
const SCEVConstant *C = dyn_cast<SCEVConstant>(Step);
@@ -1047,11 +1046,11 @@ MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx,
BPtr->getType()->getPointerAddressSpace())
return Dependence::Unknown;
const SCEV *AScev = replaceSymbolicStrideSCEV(PSE, Strides, APtr);
const SCEV *BScev = replaceSymbolicStrideSCEV(PSE, Strides, BPtr);
const SCEV *AScev = replaceSymbolicStrideSCEV(SE, Strides, Preds, APtr);
const SCEV *BScev = replaceSymbolicStrideSCEV(SE, Strides, Preds, BPtr);
int StrideAPtr = isStridedPtr(PSE, APtr, InnermostLoop, Strides);
int StrideBPtr = isStridedPtr(PSE, BPtr, InnermostLoop, Strides);
int StrideAPtr = isStridedPtr(SE, APtr, InnermostLoop, Strides, Preds);
int StrideBPtr = isStridedPtr(SE, BPtr, InnermostLoop, Strides, Preds);
const SCEV *Src = AScev;
const SCEV *Sink = BScev;
@@ -1068,10 +1067,10 @@ MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx,
std::swap(StrideAPtr, StrideBPtr);
}
const SCEV *Dist = PSE.getSE()->getMinusSCEV(Sink, Src);
const SCEV *Dist = SE->getMinusSCEV(Sink, Src);
DEBUG(dbgs() << "LAA: Src Scev: " << *Src << "Sink Scev: " << *Sink
<< "(Induction step: " << StrideAPtr << ")\n");
<< "(Induction step: " << StrideAPtr << ")\n");
DEBUG(dbgs() << "LAA: Distance for " << *InstMap[AIdx] << " to "
<< *InstMap[BIdx] << ": " << *Dist << "\n");
@@ -1344,10 +1343,10 @@ bool LoopAccessInfo::canAnalyzeLoop() {
}
// ScalarEvolution needs to be able to find the exit count.
const SCEV *ExitCount = PSE.getSE()->getBackedgeTakenCount(TheLoop);
if (ExitCount == PSE.getSE()->getCouldNotCompute()) {
emitAnalysis(LoopAccessReport()
<< "could not determine number of loop iterations");
const SCEV *ExitCount = SE->getBackedgeTakenCount(TheLoop);
if (ExitCount == SE->getCouldNotCompute()) {
emitAnalysis(LoopAccessReport() <<
"could not determine number of loop iterations");
DEBUG(dbgs() << "LAA: SCEV could not compute the loop exit count.\n");
return false;
}
@@ -1448,7 +1447,7 @@ void LoopAccessInfo::analyzeLoop(const ValueToValueMap &Strides) {
MemoryDepChecker::DepCandidates DependentAccesses;
AccessAnalysis Accesses(TheLoop->getHeader()->getModule()->getDataLayout(),
AA, LI, DependentAccesses, PSE);
AA, LI, DependentAccesses, Preds);
// Holds the analyzed pointers. We don't want to call GetUnderlyingObjects
// multiple times on the same object. If the ptr is accessed twice, once
@@ -1499,7 +1498,8 @@ void LoopAccessInfo::analyzeLoop(const ValueToValueMap &Strides) {
// read a few words, modify, and write a few words, and some of the
// words may be written to the same address.
bool IsReadOnlyPtr = false;
if (Seen.insert(Ptr).second || !isStridedPtr(PSE, Ptr, TheLoop, Strides)) {
if (Seen.insert(Ptr).second ||
!isStridedPtr(SE, Ptr, TheLoop, Strides, Preds)) {
++NumReads;
IsReadOnlyPtr = true;
}
@@ -1529,7 +1529,7 @@ void LoopAccessInfo::analyzeLoop(const ValueToValueMap &Strides) {
// Find pointers with computable bounds. We are going to use this information
// to place a runtime bound check.
bool CanDoRTIfNeeded =
Accesses.canCheckPtrAtRT(PtrRtChecking, PSE.getSE(), TheLoop, Strides);
Accesses.canCheckPtrAtRT(PtrRtChecking, SE, TheLoop, Strides);
if (!CanDoRTIfNeeded) {
emitAnalysis(LoopAccessReport() << "cannot identify array bounds");
DEBUG(dbgs() << "LAA: We can't vectorize because we can't find "
@@ -1556,7 +1556,6 @@ void LoopAccessInfo::analyzeLoop(const ValueToValueMap &Strides) {
PtrRtChecking.reset();
PtrRtChecking.Need = true;
auto *SE = PSE.getSE();
CanDoRTIfNeeded =
Accesses.canCheckPtrAtRT(PtrRtChecking, SE, TheLoop, Strides, true);
@@ -1599,7 +1598,7 @@ void LoopAccessInfo::emitAnalysis(LoopAccessReport &Message) {
}
bool LoopAccessInfo::isUniform(Value *V) const {
return (PSE.getSE()->isLoopInvariant(PSE.getSE()->getSCEV(V), TheLoop));
return (SE->isLoopInvariant(SE->getSCEV(V), TheLoop));
}
// FIXME: this function is currently a duplicate of the one in
@@ -1680,7 +1679,7 @@ std::pair<Instruction *, Instruction *> LoopAccessInfo::addRuntimeChecks(
Instruction *Loc,
const SmallVectorImpl<RuntimePointerChecking::PointerCheck> &PointerChecks)
const {
auto *SE = PSE.getSE();
SCEVExpander Exp(*SE, DL, "induction");
auto ExpandedChecks =
expandBounds(PointerChecks, TheLoop, Loc, SE, Exp, PtrRtChecking);
@@ -1750,7 +1749,7 @@ LoopAccessInfo::LoopAccessInfo(Loop *L, ScalarEvolution *SE,
const TargetLibraryInfo *TLI, AliasAnalysis *AA,
DominatorTree *DT, LoopInfo *LI,
const ValueToValueMap &Strides)
: PSE(*SE), PtrRtChecking(SE), DepChecker(PSE, L), TheLoop(L), DL(DL),
: PtrRtChecking(SE), DepChecker(SE, L, Preds), TheLoop(L), SE(SE), DL(DL),
TLI(TLI), AA(AA), DT(DT), LI(LI), NumLoads(0), NumStores(0),
MaxSafeDepDistBytes(-1U), CanVecMem(false),
StoreToLoopInvariantAddress(false) {
@@ -1787,7 +1786,7 @@ void LoopAccessInfo::print(raw_ostream &OS, unsigned Depth) const {
<< "found in loop.\n";
OS.indent(Depth) << "SCEV assumptions:\n";
PSE.getUnionPredicate().print(OS, Depth);
Preds.print(OS, Depth);
}
const LoopAccessInfo &