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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>
- Cc: Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>, "Joseph S. Myers" <joseph at codesourcery dot com>, libc-alpha <libc-alpha at sourceware dot org>
- Date: Thu, 25 Sep 2014 16:48:43 -0400
- Subject: Re: [RFC] How to add vector math functions to Glibc
- Authentication-results: sourceware.org; auth=none
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On 09/25/2014 04:03 PM, H.J. Lu wrote:
>> Sorry, I don't understand this part, and perhaps that's why I didn't
>> understand question 7 in the previous post.
>> What does it mean for the vector library to target GCC?
Thanks for the pointer. I understand now.
> 3.1. Goal
> Main goal is to improve vectorization of GCC with OpenMP4.0 SIMD
> constructs (#2.8 in http://www.openmp.org/mp-documents/OpenMP4.0.0.pdf
> and Cilk Plus constructs (#6-8 in
> on x86_64 by adding SSE4, AVX and AVX2 vector implementations of
> several vector math functions (float and double versions). AVX-512
> versions are planned to be added later. These functions can be also
> used manually (with intrinsics) by developers to obtain speedup.
> So it is mainly for GCC.
The only counter-argument to that is that a single implementation
in glibc can be shared by gcc and llvm or any other compiler. As
noted in "3.5 Open questions, a."
Intel needs to decide where they want this piece of technology
to reside. I don't know that the community can make this choice
The community is ready to work with Intel to implement this in
I've tried to clarify a few of these: