From owner-freebsd-bugs@freebsd.org  Wed Apr  5 01:35:39 2017
Return-Path: <owner-freebsd-bugs@freebsd.org>
Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2986ED2DFE8
 for <freebsd-bugs@mailman.ysv.freebsd.org>;
 Wed,  5 Apr 2017 01:35:39 +0000 (UTC)
 (envelope-from bugzilla-noreply@freebsd.org)
Received: from kenobi.freebsd.org (kenobi.freebsd.org
 [IPv6:2001:1900:2254:206a::16:76])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 197AC236
 for <freebsd-bugs@FreeBSD.org>; Wed,  5 Apr 2017 01:35:39 +0000 (UTC)
 (envelope-from bugzilla-noreply@freebsd.org)
Received: from bugs.freebsd.org ([127.0.1.118])
 by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v351Zcxm097214
 for <freebsd-bugs@FreeBSD.org>; Wed, 5 Apr 2017 01:35:38 GMT
 (envelope-from bugzilla-noreply@freebsd.org)
From: bugzilla-noreply@freebsd.org
To: freebsd-bugs@FreeBSD.org
Subject: [Bug 218387] -march=native or any specific CPU seems to produce x87
 math a lot
Date: Wed, 05 Apr 2017 01:35:39 +0000
X-Bugzilla-Reason: AssignedTo
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: Base System
X-Bugzilla-Component: bin
X-Bugzilla-Version: CURRENT
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: Affects Only Me
X-Bugzilla-Who: kungfujesus06@gmail.com
X-Bugzilla-Status: New
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: ---
X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform
 op_sys bug_status bug_severity priority component assigned_to reporter
Message-ID: <bug-218387-8@https.bugs.freebsd.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-bugs>,
 <mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs/>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
 <mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 05 Apr 2017 01:35:39 -0000

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D218387

            Bug ID: 218387
           Summary: -march=3Dnative or any specific CPU seems to produce x87
                    math a lot
           Product: Base System
           Version: CURRENT
          Hardware: amd64
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: bin
          Assignee: freebsd-bugs@FreeBSD.org
          Reporter: kungfujesus06@gmail.com

I think this is a bug, but perhaps I just think it is because the behavior
diverges from GCC by quite a bit.

When you compile an application that does floating point math with clang in
current right now, specifying -march=3Dnative or -march=3Dsandybridge or bt=
ver2 or
any number of CPUs I tried to target produces predominantly x87 instruction=
s.=20
Typically GCC and most other compilers I've seen default to targeting SSE
instructions, instead.

If you specify -march=3Dx86-64, you get the results you'd expect (predomina=
ntly
SSE2 instructions for floating point).  This leads me to believe this is a =
bug,
for most everything SSE units should be the most optimal.

--=20
You are receiving this mail because:
You are the assignee for the bug.=