On Thu, Aug 10, 2023 at 03:08:11PM +0000, Zhang, Annita via Gcc-patches wrote:
> > IMO it is not acceptable for AVX10-256 to generate zmm registers.
> >
> > If I have to choose among the three proposal, the second is better.
> >
> > But the best choice I suppose is to keep what we are doing currently, which
> > is
> > passing them in memory and emit a warning. It is a reasonable behavior.
Completely agree on this. If anything in the psABI should be changed, that
IMHO would be just clarification if it is not clear enough that when __m256
and/or __m512 are passed on ISAs which do not support those they are passed
in memory. That is what the psABI was clearly effectively saying before the
__m256 resp. __m512 support has been added there.
So yes, warn and use memory if ISA doesn't support those.
Jakub
