[PATCH 1/N] x86_64 vectorization support: vectorized math functions addition to Glibc

[Joseph Myers]

On Mon, 17 Nov 2014, Zamyatin, Igor wrote:

> > An alternative to having a processor clause now would be having an ABI/API
> > document for OpenMP on x86_64 - agreed between implementations - that
> > specifies what vector versions of a function the standard pragma means are
> > available, and specifies that implementations must not generate calls to
> > versions not listed unless some non-standard pragma is used to declare
> > those other versions to be available (which would put off defining such a
> > non-standard pragma until there is a desire to have vector versions for
> > newer ISAs).
> 
> We can prepare a document that describes what compiler (gcc 4.9 and 
> gcc5) can generate (and of course make sure that we have all those 
> versions in glibc) for x86_64 and put it somewhere on gcc.gnu.org (e.g. 
> Release notes?) and, say, on glibc wiki. Will it be enough for now?

I'm thinking of a document that multiple implementations have accepted as 
describing the intended semantics of the pragma as regard what function 
versions may be assumed to be present, so that we can expect glibc using 
that pragma in installed headers to work with future versions of multiple 
compilers, rather than something GCC-specific.

-- 
Joseph S. Myers
joseph@codesourcery.com