[PATCH] D41587: [AArch64] Change order of candidate FMLS patterns

[Florian Hahn via Phabricator via llvm-commits]

fhahn accepted this revision.
fhahn added a comment.
This revision is now accepted and ready to land.

Thanks for spotting this!
The reordering looks good to me, give the current behavior of the MachineCombiner it makes sense to move up the more profitable patterns.

> However, the order in which we add the patterns to the list of candidates determines the transformation that takes place, since only the first pattern that matches will be used.

This behavior is not ideal though, especially as some order of patterns might be good for one micro architecture, whereas a different order is better for a different micro architecture.

I'll try to look into this. Maybe it's worth to change the MachineCombiner to try all available patterns.


https://reviews.llvm.org/D41587