qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Ludovic Drolez <ldrolez@linbox.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] QEMU x86_64: problems with floats
Date: Fri, 15 Dec 2006 11:10:16 +0100	[thread overview]
Message-ID: <45827488.5@linbox.com> (raw)

Hi !

I've found a bug in Qemu FPU emulation: conversion of floats to strings fails
in some cases. For example, Ganglia (cluster monitoring software), shows
random values. If I add debug in gmond, I get this:

VALUE =2.G= =2.343750=
VALUE =2.G= =2.343750=
VALUE =9Ö= =93.487236=
VALUE =0.6o= =0.640000=
VALUE =0.1;= =0.119600=
VALUE =0.00= =0.000311=
VALUE =0.0= =0.000000=
VALUE =0.0= =0.000000=
VALUE =9.ê= =95.312500=
VALUE =0.9= =0.940000=
VALUE =0.4Y= =0.420000=
VALUE =0.1;= =0.113054=
VALUE =0.00= =0.000536=

On the left the float is converted with apr_sprintf, and on the right with
printf. Also, floating point operations in PHP also fail...

I tested with Qemu 0.8.2 and today's CVS. Of course, it works with a real
system (the disk image was then installed on a PE1950).

Any ideas ?


-- 
Ludovic DROLEZ                              Linbox / Free&ALter Soft
www.linbox.com www.linbox.org	

             reply	other threads:[~2006-12-15 10:10 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-15 10:10 Ludovic Drolez [this message]
  -- strict thread matches above, loose matches on Subject: below --
2006-12-15  9:40 [Qemu-devel] QEMU x86_64: problems with floats Ludovic Drolez

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=45827488.5@linbox.com \
    --to=ldrolez@linbox.com \
    --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).