public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Richard Henderson <rth@redhat.com>
To: harsha.jagasia@amd.com
Cc: gcc-patches@gcc.gnu.org, hubicka@ucw.cz, ubizjak@gmail.com,
	       hjl.tools@gmail.com, Changpeng.Fang@amd.com
Subject: Re: AVX generic mode tuning discussion.
Date: Tue, 12 Jul 2011 22:29:00 -0000	[thread overview]
Message-ID: <4E1CC32B.3060004@redhat.com> (raw)
In-Reply-To: <20110712212201.23194.45716.sendpatchset@gccpike4.amd.com>

On 07/12/2011 02:22 PM, harsha.jagasia@amd.com wrote:
> We would like to propose changing AVX generic mode tuning to generate 128-bit
> AVX instead of 256-bit AVX.

You indicate a 3% reduction on bulldozer with avx256.
How does avx128 compare to -mno-avx -msse4.2?
Will the next AMD generation have a useable avx256?

I'm not keen on the idea of generic mode being tune
for a single processor revision that maybe shouldn't
actually be using avx at all.


r~

  reply	other threads:[~2011-07-12 21:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-12 22:26 harsha.jagasia
2011-07-12 22:29 ` Richard Henderson [this message]
2011-07-13  8:49   ` Richard Guenther
2011-07-13  9:07     ` Jakub Jelinek
2011-07-21 21:37     ` Jagasia, Harsha
2013-01-07 18:24     ` FW: " Jagasia, Harsha
     [not found]     ` <873A3B0C5474B84F92B91855BCB4FE1625438297@sausexdag01.amd.com>
2013-01-08 11:22       ` Richard Biener
2011-07-21 21:18   ` Jagasia, Harsha
     [not found]   ` <63EE40A00BA43F49B85FACBB03F078B60821086630@sausexmbp02.amd.com>
2011-10-31 21:21     ` Jagasia, Harsha
2011-11-01  9:47       ` Richard Guenther
2011-11-02 17:17         ` Jagasia, Harsha
2011-11-02 20:50           ` Richard Guenther

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4E1CC32B.3060004@redhat.com \
    --to=rth@redhat.com \
    --cc=Changpeng.Fang@amd.com \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=harsha.jagasia@amd.com \
    --cc=hjl.tools@gmail.com \
    --cc=hubicka@ucw.cz \
    --cc=ubizjak@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).