diff options
Diffstat (limited to 'lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | lib/Analysis/ValueTracking.cpp | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp index 4f48753..5264745 100644 --- a/lib/Analysis/ValueTracking.cpp +++ b/lib/Analysis/ValueTracking.cpp @@ -188,7 +188,8 @@ static void computeKnownBitsMul(Value *Op0, Value *Op1, bool NSW, KnownOne.setBit(BitWidth - 1); } -void llvm::computeKnownBitsLoad(const MDNode &Ranges, APInt &KnownZero) { +void llvm::computeKnownBitsFromRangeMetadata(const MDNode &Ranges, + APInt &KnownZero) { unsigned BitWidth = KnownZero.getBitWidth(); unsigned NumRanges = Ranges.getNumOperands() / 2; assert(NumRanges >= 1); @@ -338,7 +339,7 @@ void llvm::computeKnownBits(Value *V, APInt &KnownZero, APInt &KnownOne, default: break; case Instruction::Load: if (MDNode *MD = cast<LoadInst>(I)->getMetadata(LLVMContext::MD_range)) - computeKnownBitsLoad(*MD, KnownZero); + computeKnownBitsFromRangeMetadata(*MD, KnownZero); break; case Instruction::And: { // If either the LHS or the RHS are Zero, the result is zero. @@ -733,6 +734,12 @@ void llvm::computeKnownBits(Value *V, APInt &KnownZero, APInt &KnownOne, break; } case Instruction::Call: + case Instruction::Invoke: + if (MDNode *MD = cast<Instruction>(I)->getMetadata(LLVMContext::MD_range)) + computeKnownBitsFromRangeMetadata(*MD, KnownZero); + // If a range metadata is attached to this IntrinsicInst, intersect the + // explicit range specified by the metadata and the implicit range of + // the intrinsic. if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) { switch (II->getIntrinsicID()) { default: break; @@ -742,16 +749,16 @@ void llvm::computeKnownBits(Value *V, APInt &KnownZero, APInt &KnownOne, // If this call is undefined for 0, the result will be less than 2^n. if (II->getArgOperand(1) == ConstantInt::getTrue(II->getContext())) LowBits -= 1; - KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - LowBits); + KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - LowBits); break; } case Intrinsic::ctpop: { unsigned LowBits = Log2_32(BitWidth)+1; - KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - LowBits); + KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - LowBits); break; } case Intrinsic::x86_sse42_crc32_64_64: - KnownZero = APInt::getHighBitsSet(64, 32); + KnownZero |= APInt::getHighBitsSet(64, 32); break; } } @@ -1977,7 +1984,7 @@ bool llvm::isSafeToSpeculativelyExecute(const Value *V, return true; case Instruction::UDiv: case Instruction::URem: - // x / y is undefined if y == 0, but calcuations like x / 3 are safe. + // x / y is undefined if y == 0, but calculations like x / 3 are safe. return isKnownNonZero(Inst->getOperand(1), TD); case Instruction::SDiv: case Instruction::SRem: { @@ -2000,12 +2007,12 @@ bool llvm::isSafeToSpeculativelyExecute(const Value *V, // Speculative load may create a race that did not exist in the source. LI->getParent()->getParent()->hasFnAttribute(Attribute::SanitizeThread)) return false; - return LI->getPointerOperand()->isDereferenceablePointer(); + return LI->getPointerOperand()->isDereferenceablePointer(TD); } case Instruction::Call: { if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) { switch (II->getIntrinsicID()) { - // These synthetic intrinsics have no side-effects, and just mark + // These synthetic intrinsics have no side-effects and just mark // information about their operands. // FIXME: There are other no-op synthetic instructions that potentially // should be considered at least *safe* to speculate... |