[PATCH] D55182: InstCombine: Scalarize single use icmp/fcmp

Mon Dec 10 11:39:42 PST 2018

spatel accepted this revision.
spatel added a comment.
This revision is now accepted and ready to land.

LGTM - but I think there's a bug in cheapToScalarize() that I didn't notice before. Please put a FIXME note in there.

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Comment at: test/Transforms/InstCombine/scalarization.ll:140-143
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <4 x i32> [[X:%.*]], zeroinitializer
-; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x i1> [[CMP]], i32 2
-; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <4 x i1> [[Y:%.*]], i32 2
-; CHECK-NEXT:    [[R:%.*]] = and i1 [[TMP1]], [[TMP2]]
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This doesn't look right to start with. I don't think we can justify leaving more instructions than we started with as a target-independent combine.

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  https://reviews.llvm.org/D55182/new/

https://reviews.llvm.org/D55182