Re: libmvec in gcc to have vector math in fortran

[Richard Biener <richard.guenther@gmail.com>]

On Fri, Jun 15, 2018 at 10:59 PM Joseph Myers <joseph@codesourcery.com> wrote:
>
> On Fri, 15 Jun 2018, Thomas Koenig wrote:
>
> > Hi Richard,
> >
> > > First and foremost we need a syntax that actually works for the
> > > Fortran frontend and a way to automatically include this special
> > > header / module.
> >
> > I can imagine parsing the relevant headers while compiling gfortran
> > and generating C code from it, which could then be #included in the
> > compiler source code. It should be possible to extend mathbuiltins.def
> > that way.
>
> The libmvec functions present depend on the multilib (for example, glibc
> only currently supports them for x86_64, not for 32-bit x86).  Given this
> multilib dependence, parsing the glibc headers when building the compiler
> itself is probably not a sensible option.

I'm thinking of sth like the C stdc-predef.h header which is always included
by the compiler.  So it needs to be sth parseable by gfortran which means
it needs to be a module or sth equivalent to a fortran include file.
GCC supports -include on the command-line, gfortran does not and it
could also support sth like -use FOO to import module FOO.  The rest could
be then done by specs processing (or similar to the stdc-predef.h via
a fortran specific target hook).

Richard.

>
> --
> Joseph S. Myers
> joseph@codesourcery.com