linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Felipe Alfaro Solana <felipe_alfaro@linuxmail.org>
To: "J.A. Magallon" <jamagallon@able.es>
Cc: Lista Linux-Kernel <linux-kernel@vger.kernel.org>
Subject: Re: gcc -O3 and register usage
Date: Tue, 19 Aug 2003 12:17:19 +0200	[thread overview]
Message-ID: <1061288238.667.1.camel@teapot.felipe-alfaro.com> (raw)
In-Reply-To: <20030819001507.GA2015@werewolf.able.es>

On Tue, 2003-08-19 at 02:15, J.A. Magallon wrote:

> Does this mean that since PentiumPro gcc has one other register (%dl)
> available, and it uses it only at -O3 ?

AFAIK, the EDX 32-bit register is splitted in two 16-bit halves, being
the least significant half called DX which, at the sime time, is
splitted in two 8-bit halves of which the most significant is called DH,
while the least significant is called DL.

So, DL is not a new register, but the least significant 8-bits from the
EDX CPU register.


      reply	other threads:[~2003-08-19 10:17 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-08-19  0:15 gcc -O3 and register usage J.A. Magallon
2003-08-19 10:17 ` Felipe Alfaro Solana [this message]

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=1061288238.667.1.camel@teapot.felipe-alfaro.com \
    --to=felipe_alfaro@linuxmail.org \
    --cc=jamagallon@able.es \
    --cc=linux-kernel@vger.kernel.org \
    /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 NNTP newsgroup(s).