[PATCH] D126713: [SLPVectorizer] Fix extractelement insertion point

Tue May 31 13:31:19 PDT 2022

anna added a comment.

In D126713#3548047 <https://reviews.llvm.org/D126713#3548047>, @ABataev wrote:

> Thanks for the patch.
>
> 1. Would be good to check if it affects the vectorization of the SPECs.

Could you pls elaborate? Unfortunately, I don't know what needs to be done here and I think irrespective of any vectorization "performance issue", we would need to fix the *functional problem*.

> 2. I think the test can be reduced more.

Will do.

> The original patch is not the cause of the issue, it just reveals it. This patch also does not fix the issue, it just hides it.

yes, it exposed the issue and I do not know what the actual issue is. However, we don't have any forward path downstream (with applications failing with this assertion failure) and I believe the ideal solution is to revert the exposing patch, fix the issue correctly and then land it again, if the actual fix is more involved.

As you can see there are a whole bunch of tests that need to be fixed as well for this (at least the X86 ones were CHECK updates) and if this is not the correct fix, I think it best to revert the change to allow unblocking failing issues.

Repository:
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https://reviews.llvm.org/D126713