[PATCH] D20477: [x86, AVX] don't add a vzeroupper if that's what the code is already doing (PR27823)

[Sanjay Patel via llvm-commits]

spatel added a comment.

In http://reviews.llvm.org/D20477#436382, @RKSimon wrote:

> Can we add tests for explicit calls to vzeroall/vzeroupper that is half way through the function with ymm accesses before + after?


Thanks, Simon and Amjad.
I'm not sure of all of the cases that we need to handle, but I've started a file for that purpose with:
http://reviews.llvm.org/rL270375
That's a simplification of the example I noted in:
https://llvm.org/bugs/show_bug.cgi?id=27823#c3

I'll add a FIXME comment to this patch, so we know that this is not the complete solution.


http://reviews.llvm.org/D20477