[PATCH] D113970: [SelectionDAG] Add pattern to haveNoCommonBitsSet.

Wed Nov 24 08:16:05 PST 2021

spatel added a comment.

In D113970#3151642 <https://reviews.llvm.org/D113970#3151642>, @OmerAviram wrote:

> In D113970#3151343 <https://reviews.llvm.org/D113970#3151343>, @spatel wrote:
>
>> Do we expect all vector types/targets to bypass this in some way? If yes, it's worth adding a comment to the patch description and/or code. If no, can we find a test that shows an asm difference?
>
> What exactly do you mean by bypass it? This addition to haveNoCommonBitsSet works for vector types as well. Do you mean add another lit test for vector types?

I mean are there TLI hooks (for example hasAndNot) or other transforms that will trigger before or after this such that vector instructions are never affected? 
It sounds like the answer is 'no'. Therefore, yes we should have another lit test with vector types, so we can see the difference from this patch.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D113970/new/

https://reviews.llvm.org/D113970