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| author | Craig Topper <craig.topper@intel.com> | 2018-09-13 18:52:58 +0000 |
|---|---|---|
| committer | Craig Topper <craig.topper@intel.com> | 2018-09-13 18:52:58 +0000 |
| commit | 8fc05ce34016bcdf2529ed6bcfcb05e450b4e034 (patch) | |
| tree | 63864ae899b059f5421a48fc4264adf3cae26779 /llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | |
| parent | 3fc5e72d84178c55faef8784c2d0e6c33a5639cd (diff) | |
| download | bcm5719-llvm-8fc05ce34016bcdf2529ed6bcfcb05e450b4e034.tar.gz bcm5719-llvm-8fc05ce34016bcdf2529ed6bcfcb05e450b4e034.zip | |
[InstCombine] Fold (xor (min/max X, Y), -1) -> (max/min ~X, ~Y) when X and Y are freely invertible.
This allows the xor to be removed completely.
This might help with recomitting r341674, but seems good regardless.
Coincidentally fixes PR38915.
Differential Revision: https://reviews.llvm.org/D51964
llvm-svn: 342163
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index a388269d6e6..b7e237eb6ed 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1847,6 +1847,8 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { // MIN(~a, ~b) -> ~MAX(a, b) Value *A, *B; if (match(LHS, m_Not(m_Value(A))) && match(RHS, m_Not(m_Value(B))) && + !IsFreeToInvert(A, A->hasOneUse()) && + !IsFreeToInvert(B, B->hasOneUse()) && (!LHS->hasNUsesOrMore(3) || !RHS->hasNUsesOrMore(3))) { CmpInst::Predicate InvertedPred = getInverseMinMaxPred(SPF); Value *InvertedCmp = Builder.CreateICmp(InvertedPred, A, B); |
