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[InstCombine] Add check of i1 types in select-to-zext/sext transformation 

When doing select-to-zext/sext transformations, we should
not handle TrueVal and FalseVal of i1 type otherwise it
would result in zext/sext i1 to i1.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D93272
This commit is contained in:
Congzhe Cao 2020-12-21 13:33:58 -05:00 committed by CongzheUalberta
parent 6bbb04a732
commit c60a58f8d4
1 changed files with 4 additions and 1 deletions
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5
llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
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@ -2606,7 +2606,10 @@ Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
// select i1 %c, <2 x i8> <1, 1>, <2 x i8> <0, 0>
// because that may need 3 instructions to splat the condition value:
// extend, insertelement, shufflevector.
if (SelType->isIntOrIntVectorTy() &&
//
// Do not handle i1 TrueVal and FalseVal otherwise would result in
// zext/sext i1 to i1.
if (SelType->isIntOrIntVectorTy() && !SelType->isIntOrIntVectorTy(1) &&
CondVal->getType()->isVectorTy() == SelType->isVectorTy()) {
// select C, 1, 0 -> zext C to int
if (match(TrueVal, m_One()) && match(FalseVal, m_Zero()))