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Re: [RFC, VECTOR ABI] Allow __attribute__((vector)) in GCC by default.
- From: Ramana Radhakrishnan <ramana dot gcc at googlemail dot com>
- To: Joseph Myers <joseph at codesourcery dot com>
- Cc: Jeff Law <law at redhat dot com>, Kirill Yukhin <kirill dot yukhin at gmail dot com>, Jakub Jelinek <jakub at redhat dot com>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Wed, 7 Oct 2015 18:34:18 +0100
- Subject: Re: [RFC, VECTOR ABI] Allow __attribute__((vector)) in GCC by default.
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- References: <20151005130733 dot GB62312 at msticlxl57 dot ims dot intel dot com> <alpine dot DEB dot 2 dot 10 dot 1510051320120 dot 16355 at digraph dot polyomino dot org dot uk> <561551B0 dot 70507 at redhat dot com> <alpine dot DEB dot 2 dot 10 dot 1510071719530 dot 29388 at digraph dot polyomino dot org dot uk>
On Wed, Oct 7, 2015 at 6:22 PM, Joseph Myers <joseph@codesourcery.com> wrote:
> On Wed, 7 Oct 2015, Jeff Law wrote:
>
>> I'm not sure why this attribute isn't documented, but clearly that should be
>> fixed.
>
> I assume the reasoning was: we document support for Cilk+ (and what's
> included in Cilk+ is externally documented). When it becomes a generic
> GNU C attribute, that reasoning no longer applies.
I do not understand enough of this feature but since this is becoming
a GNU C attribute, what happens with functions which are marked
__attribute__((vector)) but are compiled for platforms that do not
support vector clones or have options to compile for soft float - what
is the expected behaviour for the compiler in those situations ?
Presumably the __attribute__((vector)) has no effect ? Might also be
useful to document that.
I also suppose the behaviour is dependent as usual on command line
options, target options, pragmas etc ?
regards
Ramana