Fortran vector math header

[Joseph Myers]

On Tue, 22 Jan 2019, Richard Biener wrote:

> > Or instead just come up with target specific strings to determine the ABI,
> > say i386, x86_64 and x32 for the 3 ABIs on x86, powerpc{,64}{,le} on rs6000
> > etc.
> 
> Yeah, I would even suggest to use a target hook multilib_ABI_active_p
> (const char *)
> for this ... (where the hook should diagnose unknown multilib specifiers).

A header from a newer glibc version, supporting new ABIs, should still be 
usable with an older GCC version, not supporting some of those ABIs.  
Thus I don't think the hook should diagnose unknown specifiers from such a 
header.  (This is just like how a C header can test new predefined macros 
without an old GCC complaining it doesn't know what would define those 
macros.)

-- 
Joseph S. Myers
joseph@codesourcery.com