[PATCH] D34032: [Power9] Exploit vector extract with variable index

[Zaara Syeda via Phabricator via llvm-commits]

syzaara added a comment.

In https://reviews.llvm.org/D34032#776682, @nemanjai wrote:

> I suspect that the total latency of an `LI, VEXTU[BH][LR]X` for extracting constant elements is probably less than the current set up when a shift in the vector element is required. We should probably use these new instructions for such extractions as well.
>  When it comes to word extractions, I don't think it makes a difference, but halfword and byte ones are probably better off using the new instructions.
>  I'm fine with that being a separate patch, but we shouldn't forget it.


The LI was already being added when using an immediate value for the index. I added a new testcase to cover this case.


https://reviews.llvm.org/D34032