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 239CA388F031; Sun, 11 Apr 2021 01:44:25 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 239CA388F031
From: "luc.vanoostenryck at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/100028] New: arm64 failure to generate bfxil
Date: Sun, 11 Apr 2021 01:44:22 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 10.2.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: luc.vanoostenryck at gmail dot com
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
 keywords bug_severity priority component assigned_to reporter
 target_milestone cf_gcctarget attachments.created
Message-ID: <bug-100028-4@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: <https://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: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Sun, 11 Apr 2021 01:44:27 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100028

            Bug ID: 100028
           Summary: arm64 failure to generate bfxil
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: luc.vanoostenryck at gmail dot com
  Target Milestone: ---
            Target: aarch64

Created attachment 50555
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D50555&action=3Dedit
should generate bfxil but doesn't

The attached code reproduced here:

#define W       3
#define L       11

int bfxil(int d, int s)
{
        int wmask =3D (1 << W) - 1;
        return (d & ~wmask) | ((s >> L) & wmask);
}

Should return:
        bfxil:
                bfxil   w0, w1, 11, 3
                ret

but instead returns:
        bfxil:
                ubfx    x1, x1, 11, 3
                and     w0, w0, -8
                orr     w0, w1, w0
                ret

The problem is still present in trunk, was also present in 9.3 but wasn't in
GCC 8.2 (see https://gcc.godbolt.org/z/E6z31hr9r ).=