On Wed, Mar 13, 2019 at 01:01:54PM +0100, Richard Biener wrote:
> On Wed, Mar 13, 2019 at 12:40 AM Jakub Jelinek <ja...@redhat.com> wrote:
> >
> > On Tue, Mar 12, 2019 at 11:21:26PM +0000, Steve Ellcey wrote:
> > > I like this idea. I have prototyped something, I created 'vector_asm'
> > > as an aarch64 attribute because I couldn't find where to put global
> > > attributes like __simd__. Does anyone know where these are listed?
> >
> > gcc/c-family/c-attribs.c
> >
> > Note, vector_asm seems like a bad name when the attribute is simd
> > or directive #pragma omp declare simd, it should be simd_asm instead.
> >
> > If we go this route, glibc headers would need to use it conditional on gcc
> > version though, because older gccs wouldn't support that attribute.
>
> And that fortran support patch would need yet another iteration.
>
> That said, I dislike it and I do not see why a solution in glibc needs to be
> inefficient either.
Yeah, an alias doesn't really cost much, and has the advantage that if in
the vector version you need at some point to differentiate between the
finite only vs. full implementations, you can just by tweaking libmvec
implementation, the callers will have proper calls depending on if they were
compiled with -Ofast or -O3 etc.
Jakub
