[coyote@anim.dreamworks.com] autoconf/139: Floating point math wrong on Intel without optimizer

[Akim Demaille <akim at epita dot fr>]

Hi!,

This is not an Autoconf bug, it's a bug in the web pages that have you
believe you are reporting a bug to GCC while you actually ``chose''
the Autoconf category.

Regards,

        Akim

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• To: autoconf-gnats at sourceware dot cygnus dot com
• Subject: autoconf/139: Floating point math wrong on Intel without optimizer
• From: coyote at anim dot dreamworks dot com
• Date: 28 Jul 2000 20:41:12 -0000
• Delivery-date: Fri, 28 Jul 2000 22:41:35 +0200
• Envelope-to: akim@lrde.epita.fr
• Reply-To: coyote at anim dot dreamworks dot com
• Resent-Cc: autoconf-prs at sourceware dot cygnus dot com
• Resent-Reply-To: autoconf-gnats@sourceware.cygnus.com, coyote@anim.dreamworks.com
• Xref: nostromo.lrde.epita.fr mail.list.autoconf.prs:255

>Number:         139
>Category:       autoconf
>Synopsis:       Floating point math wrong on Intel without optimizer
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    akim
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 28 13:42:01 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     coyote@anim.dreamworks.com
>Release:        unknown-1.0
>Organization:
>Environment:
Problem shows up on HP or Compaq Intel boxes running
GNU/Linux Red Hat 6.1 release and either the 2.91.66 or
2.96 versions of GCC.  Problem does not show up on a Sun
box running Solaris and GCC 2.91.66.
>Description:
Simple floating point operations return slightly erroneous
results when the optimizer is *not* on.  These differences
can end up being significant when doing image processing for
animation.
>How-To-Repeat:
Compiler and run the attached code (e.g. g++ test.cc -o test)
>Fix:
Turn on level 2 optimization (-O2)
>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: application/octet-stream; name="test.cc"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.cc"

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