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Re: [RFC] How to add vector math functions to Glibc
- From: "Carlos O'Donell" <carlos at redhat dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>, Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>
- Cc: "Joseph S. Myers" <joseph at codesourcery dot com>, libc-alpha <libc-alpha at sourceware dot org>
- Date: Thu, 25 Sep 2014 15:27:49 -0400
- Subject: Re: [RFC] How to add vector math functions to Glibc
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On 09/25/2014 11:40 AM, H.J. Lu wrote:
> On Thu, Sep 25, 2014 at 8:17 AM, Andrew Senkevich
> <andrew.n.senkevich@gmail.com> wrote:
>>> If consensus ends up being to have such a library (libmvec or libmvect?),
>>> then the installation rules for libm.so as a linker script should go in
>>> math/Makefile, not the toplevel Makerules. (I don't know what if any
>>> changes might be needed to allow subdirectories to provide libraries as
>>> linker scripts.)
>>
>> There were three options about the place where to add vectorized math functions:
>>
>> 1. GLIBC (libm)
>> 2. GLIBC (additional library)
>> 3. GCC
>>
>> In GLIBC cases build of vectorized functions can be conditional, no
>> additional -lmvec required because of libm.so installed as linked
>> script in case of vectorized functions available, so it seems not very
>> important whether functions located in additional library or in libm.
>>
>
> I don't think they should be in libm since most of applications
> won't use those vector functions, which increase libm size
> unnecessarily. A separate library is better.
I agree. A distinct libmvec.so is best.
I see the consensus that #2 is the way forward.
Cheers,
Carlos.