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 5CC55385840C; Mon, 24 Oct 2022 18:40:13 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5CC55385840C
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1666636813;
	bh=tWc8bsAyXgNInd0Nj4FLc6vDs5mVu+PQnRCbLrjcOHc=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=g6c9sWnDO5Zd0l07Lol52eiUT/1YDJsKsQqSx+WPAuiCpJXvectpzF46+kjs4K5UP
	 /tHn9y+sY2HfOsHzHsSVSmhPZoIc6o1Pxlrk/f+XewAul3t4MQC8Ozyl2F3qonCmyF
	 8aFvlCJSRFS8AuQ16JMD318eA/1Q0My/dH3qmcQs=
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/107370] long double sqrtl constant folding is wrong
Date: Mon, 24 Oct 2022 18:40:13 +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: 10.2.1
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: pinskia at gcc dot gnu.org
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: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_status keywords everconfirmed component
 short_desc cf_reconfirmed_on
Message-ID: <bug-107370-4-Gjm3Jn8nSO@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-107370-4@http.gcc.gnu.org/bugzilla/>
References: <bug-107370-4@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=3D107370

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |wrong-code
     Ever confirmed|0                           |1
          Component|target                      |middle-end
            Summary|long double precision is    |long double sqrtl constant
                   |wrong in ARM 64             |folding is wrong
   Last reconfirmed|                            |2022-10-24

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---

Hmm, this might be a bug in mpfr though.  GCC uses MPFR to do constant fold=
ing.


Without constant folding libm produces:
1.4142135623730950488

That is:
```
#include <stdio.h>
#include <math.h>
int main(void) { volatile long double a =3D 2.0L; printf("%.20Lg \n",sqrtl(=
a)); }
```=