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 188CE3858001; Fri, 24 Nov 2023 09:55:00 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 188CE3858001
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1700819700;
	bh=MYcQQz2QRGPHZMT5No6LP+F8njZmwM4TqskaZH6Hsp8=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=V4DJaOrltfNRkw7lrPRVC2p3/7M/lFBPkSYyKISaRUnPc7up4+WHT3TD1Q2gvkBni
	 auorTOVosKE+6yocc1jKNBYSCbtW4DkFYQbSSIrC8swvNDlwnGs2Ivs+/VunVOBguH
	 sC6m6AyBRiKVxuK9xKBnO2IoWlQ8G1XpRoecDP0k=
From: "rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/111655] [11/12/13/14 Regression] wrong code
 generated for __builtin_signbit and 0./0. on x86-64 -O2
Date: Fri, 24 Nov 2023 09:54:58 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: 13.2.1
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenther at suse dot de
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 11.5
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-111655-4-SDoYBNaykT@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-111655-4@http.gcc.gnu.org/bugzilla/>
References: <bug-111655-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D111655

--- Comment #14 from rguenther at suse dot de <rguenther at suse dot de> ---
On Fri, 24 Nov 2023, amonakov at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D111655
>=20
> --- Comment #13 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
> > Then there is the MULT_EXPR x * x case
>=20
> This is PR 111701.
>=20
> It would be nice to clarify what "nonnegative" means in the contracts of =
this
> family of functions, because it's ambiguous for NaNs and negative zeros (=
x < 0
> is false while signbit is set, and x >=3D 0 is also false for positive Na=
Ns).

Agreed, I think we're using it in both ways which is the problem in
the end.  Maybe having _compares_nonnegative and _sign_positive
would clarify this.=