return BinaryOperator::CreateNeg(Op0);
ConstantInt *RHSNeg = cast<ConstantInt>(ConstantExpr::getNeg(RHS));
+ APInt RHSNegAPI(RHSNeg->getBitWidth(), RHSNeg->getSExtValue(), true);
+
+ APInt NegOne = -APInt(RHSNeg->getBitWidth(), 1, true);
+ APInt TwoToExp(RHSNeg->getBitWidth(), 1 << (RHSNeg->getBitWidth() - 1),
+ true);
// -X/C -> X/-C, if and only if negation doesn't overflow.
- if ((RHS->getSExtValue() < 0 &&
- RHS->getSExtValue() < RHSNeg->getSExtValue()) ||
- (RHS->getSExtValue() > 0 &&
- RHS->getSExtValue() > RHSNeg->getSExtValue())) {
+ if ((RHS->getSExtValue() < 0 && RHSNegAPI.slt(TwoToExp - 1)) ||
+ (RHS->getSExtValue() > 0 && RHSNegAPI.sgt(TwoToExp * NegOne))) {
if (Value *LHSNeg = dyn_castNegVal(Op0)) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(LHSNeg)) {
ConstantInt *CINeg = cast<ConstantInt>(ConstantExpr::getNeg(CI));
+ APInt CINegAPI(CINeg->getBitWidth(), CINeg->getSExtValue(), true);
- if ((CI->getSExtValue() < 0 &&
- CI->getSExtValue() < CINeg->getSExtValue()) ||
- (CI->getSExtValue() > 0 &&
- CI->getSExtValue() > CINeg->getSExtValue()))
+ if ((CI->getSExtValue() < 0 && CINegAPI.slt(TwoToExp - 1)) ||
+ (CI->getSExtValue() > 0 && CINegAPI.sgt(TwoToExp * NegOne)))
return BinaryOperator::CreateSDiv(LHSNeg,
ConstantExpr::getNeg(RHS));
}