[Bug target/59539] Missed optimisation: VEX-prefixed operations don't need aligned data

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59539

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Uroš Bizjak from comment #3)
> (In reply to Jakub Jelinek from comment #1)
> > Created attachment 31463 [details]
> > gcc49-pr59539.patch
> 
> From a quick look at the patch, the proposed patch doesn't support masked
> insns. 
> 
> I think it is better to introduce corresponding sse.md expanders for
> UNSPEC_STOREU and UNSPEC_LOADU insns. These expanders will either generate
> UNSPEC_* pattern or "normal" (masked) move in case of TARGET_AVX.

I can surely add the expanders, but don't understand the comment about masked
moves.  *maskload* is already a specialized UNSPEC, and can't really be merged
with arithmetic patterns (ok, perhaps with -mavx512f?) and handles both aligned
and unaligned operands the same.