From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 82C38385DC1F; Sun, 17 May 2020 00:23:29 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 82C38385DC1F
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1589675009;
 bh=Y++uPgmQ4fhCwelkhzCeu7zrq7tFjeGJHYKJf83RnTg=;
 h=From:To:Subject:Date:From;
 b=t9qYxirkur0TJM+dfimbCuGl+w23fMK6lVUD7p/PN0UdHIQ9kdz2x3jMKNZ9bMlxe
 s9IRHGl/TcvVSl2zd9TwkyOOekPkf4p744Vqma+3Tm/+0musoqKaJ11MGQk3ecWmr5
 1aqoYu/4sWxRb2MCRWySLWvow95Na9O8Q9/KcAXw=
From: "samuel.thibault@ens-lyon.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/95169] New: i386 comparison between nan and 0.0 triggers
 Invalid operation exception
Date: Sun, 17 May 2020 00:23:29 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c
X-Bugzilla-Version: 10.1.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: samuel.thibault@ens-lyon.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
 attachments.created
Message-ID: <bug-95169-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <http://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <http://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Sun, 17 May 2020 00:23:29 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95169

            Bug ID: 95169
           Summary: i386 comparison between nan and 0.0 triggers Invalid
                    operation exception
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: samuel.thibault@ens-lyon.org
  Target Milestone: ---

Created attachment 48549
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D48549&action=3Dedit
testcase

Hello,

On building the attached testcase with=20

gcc-10 -m32 test.c -o test -march=3Di386 -mtune=3Dgeneric -lm

its execution prints "0 1", i.e. an Invalid operation exception is raised by
the mere comparison of y (that contains NaN) against 0.0.

This was tested with Debian's gcc-10 10.1.0-1.
This does not happen with previous versions of gcc. This happens with half =
of
the  values of -mtune (I'll attach the details) ; this also happens with
-march=3Di486, i586, pentium ; this does not happen with -march=3Di686 or
pentiumpro etc. (whatever the value of -mtune).

Samuel=