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Re: [PATCH 1/N] x86_64 vectorization support: vectorized math functions addition to Glibc
- From: Rich Felker <dalias at libc dot org>
- To: Carlos O'Donell <carlos at redhat dot com>
- Cc: Andi Kleen <andi at firstfloor dot org>, Matthew Fortune <Matthew dot Fortune at imgtec dot com>, "Joseph S. Myers" <joseph at codesourcery dot com>, Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>, libc-alpha <libc-alpha at sourceware dot org>, "igor dot zamyatin at intel dot com" <igor dot zamyatin at intel dot com>, "Melik-Adamyan, Areg" <areg dot melik-adamyan at intel dot com>, "jakub at redhat dot com" <jakub at redhat dot com>
- Date: Fri, 12 Sep 2014 15:56:19 -0400
- Subject: Re: [PATCH 1/N] x86_64 vectorization support: vectorized math functions addition to Glibc
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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.
Rich