diff options
Diffstat (limited to 'lib/Transforms/Scalar')
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index f23c10f..a5fcbc9 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -616,12 +616,13 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) { Value *SCIOp0 = SCI->getOperand(0), *SCIOp1 = SCI->getOperand(1); const Type *SCOpTy = SCIOp0->getType(); - // If the source is X < 0, and X is a signed integer type, convert this - // multiply into a shift/and combination. - if (SCI->getOpcode() == Instruction::SetLT && - isa<Constant>(SCIOp1) && cast<Constant>(SCIOp1)->isNullValue() && - SCOpTy->isInteger() && SCOpTy->isSigned()) { - + // If the source is X < 0 or X <= -1, and X is a signed integer type, + // convert this multiply into a shift/and combination. + if (SCOpTy->isSigned() && isa<ConstantInt>(SCIOp1) && + ((SCI->getOpcode() == Instruction::SetLT && + cast<Constant>(SCIOp1)->isNullValue()) || + (SCI->getOpcode() == Instruction::SetLE && + cast<ConstantInt>(SCIOp1)->isAllOnesValue()))) { // Shift the X value right to turn it into "all signbits". Constant *Amt = ConstantUInt::get(Type::UByteTy, SCOpTy->getPrimitiveSize()*8-1); |