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Re: [i386] Replace builtins with vector extensions
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Kirill Yukhin <kirill dot yukhin at gmail dot com>
- Cc: Marc Glisse <marc dot glisse at inria dot fr>, GCC Patches <gcc-patches at gcc dot gnu dot org>, Uros Bizjak <ubizjak at gmail dot com>
- Date: Tue, 8 Jul 2014 13:17:07 +0200
- Subject: Re: [i386] Replace builtins with vector extensions
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- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Tue, Jul 08, 2014 at 03:14:04PM +0400, Kirill Yukhin wrote:
> > >On the over hand, updated in such a way intrinsic
> > >may actually generate different instruction then intended (e.g. FMA case).
> >
> > It is the same with scalars, we have -ffp-contract for that.
> Agreed.
I don't think we actually always guarantee using the particular instructions
for the intrinsics even when they are implemented using builtins, at least
if they don't use UNSPECs, e.g. if combiner or peephole2 manage to combine
something into some other insn, we'll happily do that.
Jakub