From: Marc Glisse <marc.glisse@inria.fr>
To: Richard Henderson <rth@redhat.com>
Cc: Michael Zolotukhin <michael.v.zolotukhin@gmail.com>,
Kirill Yukhin <kirill.yukhin@gmail.com>,
"H.J. Lu" <hjl.tools@gmail.com>,
Uros Bizjak <ubizjak@gmail.com>,
gcc-patches List <gcc-patches@gcc.gnu.org>
Subject: Re: [i386] scalar ops that preserve the high part of a vector
Date: Fri, 07 Dec 2012 15:00:00 -0000 [thread overview]
Message-ID: <alpine.DEB.2.02.1212071552390.3800@laptop-mg.saclay.inria.fr> (raw)
In-Reply-To: <50C20079.8050001@redhat.com>
On Fri, 7 Dec 2012, Richard Henderson wrote:
> On 2012-12-07 02:49, Marc Glisse wrote:
>> For 2-element vectors, vec_concat does seem more natural than
>> vec_merge. If we chose vec_merge as the canonical representation, we
>> should chose it for setting an element in a vector
>> (ix86_expand_vector_set) everywhere, not just those scalarish
>> operations.
>
> I'd hate to enshrine vec_merge over vec_concat for the benefit of x86,
> and to the detriment of e.g. mips. There are plenty of embedded simd
> implementations that are V2xx only.
>
> If we simply pull the various x86 patterns into one common form, set
> and extract included, does that buy us most of what we'd get for
> playing games in combine?
I'm sorry, could you be more precise? I don't see clearly what you are
suggesting.
> As for your xmmintrin.h changes, I'd like to see a test case that verifies
> that _mm_add_ss(a, b) does not add extra insns to extract __B[0].
Yes, good idea, thanks.
--
Marc Glisse
next prev parent reply other threads:[~2012-12-07 15:00 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-13 9:33 Marc Glisse
2012-10-14 9:54 ` Uros Bizjak
2012-10-14 12:52 ` Marc Glisse
2012-11-30 12:36 ` Marc Glisse
2012-11-30 13:55 ` Uros Bizjak
2012-11-30 22:36 ` Marc Glisse
2012-12-01 17:27 ` Marc Glisse
2012-12-02 10:51 ` Uros Bizjak
2012-12-02 12:30 ` Marc Glisse
2012-12-03 8:53 ` Uros Bizjak
2012-12-03 15:34 ` Marc Glisse
2012-12-03 17:55 ` Uros Bizjak
2012-12-04 14:05 ` Marc Glisse
2012-12-04 16:28 ` Marc Glisse
2012-12-04 18:06 ` Uros Bizjak
2012-12-04 18:12 ` H.J. Lu
2012-12-06 13:42 ` Kirill Yukhin
2012-12-07 6:50 ` Michael Zolotukhin
2012-12-07 8:46 ` Uros Bizjak
2012-12-07 8:49 ` Marc Glisse
2012-12-07 10:52 ` Michael Zolotukhin
2012-12-07 14:02 ` Marc Glisse
2012-12-07 14:43 ` Richard Henderson
2012-12-07 14:47 ` Jakub Jelinek
2012-12-07 14:53 ` Richard Henderson
2012-12-07 15:00 ` Marc Glisse [this message]
2012-12-07 15:06 ` Richard Henderson
2012-12-07 15:12 ` Marc Glisse
2012-12-07 16:24 ` Richard Henderson
2012-12-07 17:23 ` Marc Glisse
2012-12-08 5:47 ` Marc Glisse
2012-12-12 15:48 ` Richard Henderson
2012-12-05 14:22 ` Marc Glisse
2012-12-05 17:07 ` Paolo Bonzini
2012-12-05 20:22 ` Marc Glisse
2012-12-05 21:05 ` Eric Botcazou
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