From: Aurelien Jarno <aurelien@aurel32.net>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [patch] Alpha : fix cmpbge instruction
Date: Mon, 10 Nov 2008 12:11:06 +0100 [thread overview]
Message-ID: <20081110111106.GA20280@hall.aurel32.net> (raw)
In-Reply-To: <Pine.LNX.4.44.0811100146240.20447-100000@cacao.csl.cornell.edu>
On Mon, Nov 10, 2008 at 01:48:28AM -0500, Vince Weaver wrote:
> Hello
>
> The cmpbge instruction should compare all 8 bytes of one 64-bit value with
> another. However, we were looping with a < 7 condition which was skipping
> the top byte. So if we were doing a compare where the top byte was
> important, we could get the wrong result (this notably breaks the strlen()
> function with certain sized strings).
>
> Attached is a patch
Thanks, applied.
> Index: target-alpha/op_helper.c
> ===================================================================
> --- target-alpha/op_helper.c (revision 5666)
> +++ target-alpha/op_helper.c (working copy)
> @@ -330,7 +330,7 @@
> int i;
>
> res = 0;
> - for (i = 0; i < 7; i++) {
> + for (i = 0; i < 8; i++) {
> opa = op1 >> (i * 8);
> opb = op2 >> (i * 8);
> if (opa >= opb)
>
>
>
>
--
.''`. Aurelien Jarno | GPG: 1024D/F1BCDB73
: :' : Debian developer | Electrical Engineer
`. `' aurel32@debian.org | aurelien@aurel32.net
`- people.debian.org/~aurel32 | www.aurel32.net
prev parent reply other threads:[~2008-11-10 11:11 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-10 6:48 [Qemu-devel] [patch] Alpha : fix cmpbge instruction Vince Weaver
2008-11-10 11:11 ` Aurelien Jarno [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=20081110111106.GA20280@hall.aurel32.net \
--to=aurelien@aurel32.net \
--cc=qemu-devel@nongnu.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).