https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103393
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rearnsha at gcc dot gnu.org
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to H.J. Lu from comment #2)
> (In reply to Richard Biener from comment #1)
> > It isn't the vectorizer but memmove inline expansion. I'm not sure it's
> > really a bug, but there isn't a way to disable %ymm use besides disabling
> > AVX entirely.
> > HJ?
>
> YMM move is generated by loop distribution which doesn't check
> TARGET_PREFER_AVX128.
I think it's generated by gimple_fold_builtin_memory_op which since Richards
changes accepts bigger now, up to MOVE_MAX * MOVE_RATIO and that ends up
picking an integer mode via
scalar_int_mode mode;
if (int_mode_for_size (ilen * 8, 0).exists (&mode)
&& GET_MODE_SIZE (mode) * BITS_PER_UNIT == ilen * 8
&& have_insn_for (SET, mode)
/* If the destination pointer is not aligned we must be able
to emit an unaligned store. */
&& (dest_align >= GET_MODE_ALIGNMENT (mode)
|| !targetm.slow_unaligned_access (mode, dest_align)
|| (optab_handler (movmisalign_optab, mode)
!= CODE_FOR_nothing)))
not sure if there's another way to validate things.
