diff options
| -rw-r--r-- | llvm/include/llvm/Analysis/ValueTracking.h | 7 | ||||
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 19 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp | 15 |
3 files changed, 20 insertions, 21 deletions
diff --git a/llvm/include/llvm/Analysis/ValueTracking.h b/llvm/include/llvm/Analysis/ValueTracking.h index 1616ef4b77f..0a3fab3fb71 100644 --- a/llvm/include/llvm/Analysis/ValueTracking.h +++ b/llvm/include/llvm/Analysis/ValueTracking.h @@ -384,6 +384,13 @@ class Value; /// Return true if the only users of this pointer are lifetime markers. bool onlyUsedByLifetimeMarkers(const Value *V); + /// Return true if speculation of the given load must be suppressed to avoid + /// ordering or interfering with an active sanitizer. If not suppressed, + /// dereferenceability and alignment must be proven separately. Note: This + /// is only needed for raw reasoning; if you use the interface below + /// (isSafeToSpeculativelyExecute), this is handled internally. + bool mustSuppressSpeculation(const LoadInst &LI); + /// Return true if the instruction does not have any effects besides /// calculating the result and does not have undefined behavior. /// diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index a8ee594d272..55c3e0228b2 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -3877,6 +3877,18 @@ bool llvm::onlyUsedByLifetimeMarkers(const Value *V) { return true; } +bool llvm::mustSuppressSpeculation(const LoadInst &LI) { + if (!LI.isUnordered()) + return true; + const Function &F = *LI.getFunction(); + // Speculative load may create a race that did not exist in the source. + return F.hasFnAttribute(Attribute::SanitizeThread) || + // Speculative load may load data from dirty regions. + F.hasFnAttribute(Attribute::SanitizeAddress) || + F.hasFnAttribute(Attribute::SanitizeHWAddress); +} + + bool llvm::isSafeToSpeculativelyExecute(const Value *V, const Instruction *CtxI, const DominatorTree *DT) { @@ -3921,12 +3933,7 @@ bool llvm::isSafeToSpeculativelyExecute(const Value *V, } case Instruction::Load: { const LoadInst *LI = cast<LoadInst>(Inst); - if (!LI->isUnordered() || - // Speculative load may create a race that did not exist in the source. - LI->getFunction()->hasFnAttribute(Attribute::SanitizeThread) || - // Speculative load may load data from dirty regions. - LI->getFunction()->hasFnAttribute(Attribute::SanitizeAddress) || - LI->getFunction()->hasFnAttribute(Attribute::SanitizeHWAddress)) + if (mustSuppressSpeculation(*LI)) return false; const DataLayout &DL = LI->getModule()->getDataLayout(); return isDereferenceableAndAlignedPointer(LI->getPointerOperand(), diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp index fe1e978a20d..3b3e055f01c 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp @@ -969,21 +969,6 @@ static bool isDereferenceableAndAlignedInLoop(LoadInst *LI, Loop *L, DL, HeaderFirstNonPHI, &DT); } -/// Return true if speculation of the given load must be suppressed for -/// correctness reasons. If not suppressed, dereferenceability and alignment -/// must be proven. -/// TODO: Move to ValueTracking.h/cpp in a separate change -static bool mustSuppressSpeculation(const LoadInst &LI) { - if (!LI.isUnordered()) - return true; - const Function &F = *LI.getFunction(); - // Speculative load may create a race that did not exist in the source. - return F.hasFnAttribute(Attribute::SanitizeThread) || - // Speculative load may load data from dirty regions. - F.hasFnAttribute(Attribute::SanitizeAddress) || - F.hasFnAttribute(Attribute::SanitizeHWAddress); -} - bool LoopVectorizationLegality::canVectorizeWithIfConvert() { if (!EnableIfConversion) { reportVectorizationFailure("If-conversion is disabled", |
