Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.711 -> 1.712 --- Log message: Make sure the use of ConstantInt::getZExtValue() for shift amount safe. --- Diffs of the changes: (+20 -18) InstructionCombining.cpp | 38 ++++++++++++++++++++------------------ 1 files changed, 20 insertions(+), 18 deletions(-) Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.711 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.712 --- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.711 Fri Mar 30 04:29:48 2007 +++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Fri Mar 30 12:20:39 2007 @@ -1354,7 +1354,7 @@ } if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) { - unsigned ShiftAmt = SA->getZExtValue(); + uint32_t ShiftAmt = SA->getLimitedValue(BitWidth); // Signed shift right. APInt DemandedMaskIn(DemandedMask.shl(ShiftAmt)); @@ -2095,12 +2095,12 @@ // -(X >>u 31) -> (X >>s 31) // -(X >>s 31) -> (X >>u 31) - if (C->isNullValue()) { + if (C->isZero()) { if (BinaryOperator *SI = dyn_cast<BinaryOperator>(Op1)) if (SI->getOpcode() == Instruction::LShr) { if (ConstantInt *CU = dyn_cast<ConstantInt>(SI->getOperand(1))) { // Check to see if we are shifting out everything but the sign bit. - if (CU->getZExtValue() == + if (CU->getLimitedValue(SI->getType()->getPrimitiveSizeInBits()) == SI->getType()->getPrimitiveSizeInBits()-1) { // Ok, the transformation is safe. Insert AShr. return BinaryOperator::create(Instruction::AShr, @@ -2111,7 +2111,7 @@ else if (SI->getOpcode() == Instruction::AShr) { if (ConstantInt *CU = dyn_cast<ConstantInt>(SI->getOperand(1))) { // Check to see if we are shifting out everything but the sign bit. - if (CU->getZExtValue() == + if (CU->getLimitedValue(SI->getType()->getPrimitiveSizeInBits()) == SI->getType()->getPrimitiveSizeInBits()-1) { // Ok, the transformation is safe. Insert LShr. return BinaryOperator::createLShr( @@ -4789,7 +4789,8 @@ if (!CanFold) { // To test for the bad case of the signed shr, see if any // of the bits shifted in could be tested after the mask. - int ShAmtVal = Ty->getPrimitiveSizeInBits()-ShAmt->getZExtValue(); + uint32_t TyBits = Ty->getPrimitiveSizeInBits(); + int ShAmtVal = TyBits - ShAmt->getLimitedValue(TyBits); if (ShAmtVal < 0) ShAmtVal = 0; // Out of range shift. uint32_t BitWidth = AndTy->getPrimitiveSizeInBits(); @@ -4883,7 +4884,7 @@ if (LHSI->hasOneUse()) { // Otherwise strength reduce the shift into an and. - unsigned ShAmtVal = (unsigned)ShAmt->getZExtValue(); + uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits); uint64_t Val = (1ULL << (TypeBits-ShAmtVal))-1; Constant *Mask = ConstantInt::get(CI->getType(), Val); @@ -4926,7 +4927,7 @@ } if (LHSI->hasOneUse() || CI->isNullValue()) { - unsigned ShAmtVal = (unsigned)ShAmt->getZExtValue(); + uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits); // Otherwise strength reduce the shift into an and. APInt Val(APInt::getHighBitsSet(TypeBits, TypeBits - ShAmtVal)); @@ -5658,7 +5659,7 @@ BinaryOperator::create(Op0BO->getOpcode(), YS, V1, Op0BO->getOperand(1)->getName()); InsertNewInstBefore(X, I); // (X + (Y << C)) - uint32_t Op1Val = Op1->getZExtValue(); + uint32_t Op1Val = Op1->getLimitedValue(TypeBits); return BinaryOperator::createAnd(X, ConstantInt::get( APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val))); } @@ -5697,7 +5698,7 @@ BinaryOperator::create(Op0BO->getOpcode(), V1, YS, Op0BO->getOperand(0)->getName()); InsertNewInstBefore(X, I); // (X + (Y << C)) - uint32_t Op1Val = Op1->getZExtValue(); + uint32_t Op1Val = Op1->getLimitedValue(TypeBits); return BinaryOperator::createAnd(X, ConstantInt::get( APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val))); } @@ -6084,8 +6085,9 @@ // If we are truncating the result of this SHL, and if it's a shift of a // constant amount, we can always perform a SHL in a smaller type. if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) { - if (Ty->getBitWidth() < OrigTy->getBitWidth() && - CI->getZExtValue() < Ty->getBitWidth()) + uint32_t BitWidth = Ty->getBitWidth(); + if (BitWidth < OrigTy->getBitWidth() && + CI->getLimitedValue(BitWidth) < BitWidth) return CanEvaluateInDifferentType(I->getOperand(0), Ty,NumCastsRemoved); } break; @@ -6095,12 +6097,12 @@ // lshr iff we know that the bits we would otherwise be shifting in are // already zeros. if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) { - uint32_t BitWidth = OrigTy->getBitWidth(); - if (Ty->getBitWidth() < BitWidth && + uint32_t OrigBitWidth = OrigTy->getBitWidth(); + uint32_t BitWidth = Ty->getBitWidth(); + if (BitWidth < OrigBitWidth && MaskedValueIsZero(I->getOperand(0), - APInt::getAllOnesValue(BitWidth) & - APInt::getAllOnesValue(Ty->getBitWidth()).zextOrTrunc(BitWidth).flip()) - && CI->getZExtValue() < Ty->getBitWidth()) { + APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth)) && + CI->getLimitedValue(BitWidth) < BitWidth) { return CanEvaluateInDifferentType(I->getOperand(0), Ty, NumCastsRemoved); } } @@ -6396,7 +6398,7 @@ // simplifications. if (DestBitSize < SrcBitSize && isa<ConstantInt>(Op1)) { - unsigned ShiftAmt = cast<ConstantInt>(Op1)->getZExtValue(); + uint32_t ShiftAmt = cast<ConstantInt>(Op1)->getLimitedValue(SrcBitSize); if (SrcBitSize > ShiftAmt && SrcBitSize-ShiftAmt >= DestBitSize) { // Insert the new logical shift right. return BinaryOperator::createLShr(Op0, Op1); @@ -6486,7 +6488,7 @@ // We can shrink lshr to something smaller if we know the bits shifted in // are already zeros. if (ConstantInt *ShAmtV = dyn_cast<ConstantInt>(SrcI->getOperand(1))) { - unsigned ShAmt = ShAmtV->getZExtValue(); + uint32_t ShAmt = ShAmtV->getLimitedValue(SrcBitWidth); // Get a mask for the bits shifting in. APInt Mask(APInt::getLowBitsSet(SrcBitWidth, ShAmt).shl(DestBitWidth)); _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits