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[InstCombine] use isKnownNonNegative() for readability; NFCI 

This should be functionally equivalent - both calls are thin
wrappers around computeKnownBits(). We'll probably want to use
known-bits directly in follow-up patches because that could
determine "exact" for example (see issue #58348).
This commit is contained in:
Sanjay Patel 2022-10-14 10:47:16 -04:00
parent 067b744dbb
commit 340ae45be0
1 changed files with 3 additions and 6 deletions
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9
llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
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@ -1332,12 +1332,9 @@ Instruction *InstCombinerImpl::visitSDiv(BinaryOperator &I) {
ConstantInt::getAllOnesValue(Ty));
}
// If the sign bits of both operands are zero (i.e. we can prove they are
// unsigned inputs), turn this into a udiv.
APInt Mask(APInt::getSignMask(Ty->getScalarSizeInBits()));
if (MaskedValueIsZero(Op0, Mask, 0, &I)) {
if (MaskedValueIsZero(Op1, Mask, 0, &I)) {
// X sdiv Y -> X udiv Y, iff X and Y don't have sign bit set
if (isKnownNonNegative(Op0, DL, 0, &AC, &I, &DT)) {
// If both operands are unsigned, turn this into a udiv.
if (isKnownNonNegative(Op1, DL, 0, &AC, &I, &DT)) {
auto *BO = BinaryOperator::CreateUDiv(Op0, Op1, I.getName());
BO->setIsExact(I.isExact());
return BO;