[PATCH] D91876: [DAG] Move vselect(icmp_ult, -1, add(x,y)) -> uaddsat(x,y) to DAGCombine (PR40111)

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

In D91876#2409613 <https://reviews.llvm.org/D91876#2409613>, @RKSimon wrote:

> In D91876#2409390 <https://reviews.llvm.org/D91876#2409390>, @craig.topper wrote:
>
>> Why do we have v4i32 UADDSAT marked as Custom with SSE2, but then fail out of the LowerADDSAT_SUBSAT is UMIN isn't Legal, I think it needs SSE4.1?
>
> Because we tag UMIN/UMAX as custom on SSE2 targets so the legalizer will try to use them - I'll see if we can remove that as well.

I misread the code in LowerADDSAT_SUBSAT when I asked that question. We use the default expansion if UMIN/UMAX is legal and custom otherwise.


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https://reviews.llvm.org/D91876