The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: jrvalverde@cnb.csic.es (Jose R. Valverde)
Subject: [TUHS] Introduction
Date: Thu, 5 Jun 2008 17:07:30 +0200	[thread overview]
Message-ID: <20080605170730.35320095@veda.cnb.uam.es> (raw)
In-Reply-To: <20080604135729.4c50e178@veda.cnb.uam.es>

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 813 bytes --]

> so i created the following C code out of it:
> 
> u.u_count = (-u.u_segmts[NUSEGS-1].sg_limit+0x100)<<8;
> ...
> 
> done by having 256² - 256*x. This was great. With that information I wrote
> in C:
> 
> u.u_count = (256-u.u_segmts[NUSEGS-1].sg_limit)<<8;


What happens if you use instead

	u.u_count = (~(-u.u_segmts[NUSEGS-1].sg_limit))<<8;

That should mean the same, would avoid using a hard coded value and the
compiler may optimize it to the same assembly.

I hope you understand that any advice will probably be faulty as we can
not check the code generated by our suggestions as you do. As long as you
don't mind that, it's OK.

				j
-- 
	These opinions are mine and only mine. Hey man, I saw them first!

			    José R. Valverde

	De nada sirve la Inteligencia Artificial cuando falta la Natural



  parent reply	other threads:[~2008-06-05 15:07 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-04 11:57 Jose R. Valverde
2008-06-04 15:11 ` Oliver Lehmann
2008-06-04 15:16   ` Oliver Lehmann
2008-06-05 15:07 ` Jose R. Valverde [this message]
2008-06-05 17:59   ` Oliver Lehmann
2008-06-05 15:17 ` Jose R. Valverde
2008-06-05 17:45   ` Oliver Lehmann
2008-06-23 14:18   ` Jose R. Valverde
2008-06-23 16:11     ` Oliver Lehmann
2008-06-25  9:40       ` Jose R. Valverde
2008-06-25 10:25       ` Jose R. Valverde
2008-06-26 14:52         ` Oliver Lehmann
2008-06-27 12:24           ` Jose R. Valverde
2008-06-29  8:25             ` Oliver Lehmann
2008-06-30  9:30               ` Jose R. Valverde
2008-06-30 17:34                 ` Oliver Lehmann
2008-07-01 14:21                   ` Jose R. Valverde
2008-07-01 18:35                     ` Oliver Lehmann
2008-07-03 10:12                       ` Jose R. Valverde
2008-07-06 16:14                         ` Oliver Lehmann
2008-07-07  9:25                           ` [TUHS] SysIII/PDP-11 on SIMH (was Re: Introduction) Jose R. Valverde
2008-07-07  9:32                           ` [TUHS] Introduction Jose R. Valverde
2008-07-07 14:45                             ` Oliver Lehmann
2008-06-06  9:58 ` Jose R. Valverde
  -- strict thread matches above, loose matches on Subject: below --
2008-06-03  4:18 Oliver Lehmann

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=20080605170730.35320095@veda.cnb.uam.es \
    --to=jrvalverde@cnb.csic.es \
    /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).