[Bug target/56253] fp-contract does not work with SSE and AVX FMAs (neither FMA4 nor FMA3)

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56253

--- Comment #12 from Marc Glisse <glisse at gcc dot gnu.org> ---
(In reply to Agner Fog from comment #11)
> Thanks for the links Marc. 
> You are right, the discussion in the gcc-patches mailing list ignores
> integer vectors. You need a solution that also allows optimizations on
> integer intrinsic functions (perhaps cast the vector type?).

If you follow the links, you can find:
https://gcc.gnu.org/ml/gcc-patches/2013-04/msg00374.html
where I handled some integer vector intrinsics as well (there were some bugs in
that patch, but the idea should be fine).

> The proposed solution of using vector extensions will not work on masked
> vector intrinsics in AVX512, so it wouldn't enable e.g. constant propagation
> through a masked intrinsic, but that is probably too much to ask for :)

I expect we can get most of the benefits from using vector extensions for very
little effort, while handling the esoteric intrinsics would be a lot more work
so it gets lower priority.