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

[Jakub Jelinek]

On Fri, Sep 12, 2014 at 03:56:19PM -0400, Rich Felker wrote:
> On Fri, Sep 12, 2014 at 03:19:48PM -0400, Carlos O'Donell wrote:
> > On 09/12/2014 03:17 PM, Carlos O'Donell wrote:
> > > On 09/12/2014 01:33 AM, Andi Kleen wrote:
> > >> Rich Felker <dalias@libc.org> writes:
> > >>>
> > >>> This really seems like something the compiler should be doing --
> > >>> translating parallelizable calls to the standard math functions into
> > >>> calls to special simd versions (
> > >>
> > >> Of course gcc already supports that. Even in two different flavours.
> > >>
> > >> Not sure why the patch doesn't implement one of those ABIs though.
> > > 
> > > Please note that AFAIK gcc doesn't implement the ABI as documented
> > > by Intel, but a variant, and my expectation is that we should *absolutely*
> > > be targetting the gcc version of the Intel ABI otherwise what's the point?
> > 
> > I see Jakub already responded that there is a 3rd ABI :}
> 
> I don't see any point in targeting ABIs that don't have the function
> names in a reserved namespace, since the compiler cannot automatically
> make such transformations using non-reserved namespace.

???  The names are in reserved namespace, e.g. for
#pragma omp declare simd
double foo (double x, double y, double z) { return x + y + z; }
on i?86/x86_64 the mangled names are
_ZGVbN2vvv_foo
_ZGVbM2vvv_foo
_ZGVcN4vvv_foo
_ZGVcM4vvv_foo
_ZGVdN4vvv_foo
_ZGVdM4vvv_foo

	Jakub