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 C516C38708E1; Sat,  9 May 2020 19:19:31 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C516C38708E1
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1589051971;
 bh=YiQ9t9BlkZLUe9NphIfPlsRCMOnXriSk/JthmL8FE9w=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=xyJzFmB7TWitMMViejD179yFYY/x9EGKFGJFDN9dMd5h91XBQsRCTMotuUQwwB9A1
 TmKFmkXHDv/YwoydKsdVoXvsoap9urfdY+TZM1IP6NAk+lc0JJHCPDyNbcxTWH7yRl
 76szQk3FGTfoTU671fLdtUqHV1p1nTc7/FcMfgUM=
From: "hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/95021] [10/11 Regression] Bogus -Wclobbered warning
Date: Sat, 09 May 2020 19:19:31 +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: 10.1.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: hjl.tools at gmail dot com
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: 10.2
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_status cc cf_reconfirmed_on target_milestone
 everconfirmed
Message-ID: <bug-95021-4-SpVwzJY1o3@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-95021-4@http.gcc.gnu.org/bugzilla/>
References: <bug-95021-4@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: Sat, 09 May 2020 19:19:31 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95021

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
                 CC|                            |rguenther at suse dot de
   Last reconfirmed|                            |2020-05-09
   Target Milestone|---                         |10.2
     Ever confirmed|0                           |1

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
Need -msse2 to trigger the bug.  This caused by r10-2807:

commit 48a31a09839b12127ce7c40d7adc4bd5bf1d3407
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Aug 26 10:35:59 2019 +0000

    re PR target/91522 (STV is slow)

    2019-08-26  Richard Biener  <rguenther@suse.de>

            PR target/91522
            PR target/91527
            * config/i386/i386-features.h (general_scalar_chain::defs_map):
            New member.
            (general_scalar_chain::replace_with_subreg): Remove.
            (general_scalar_chain::replace_with_subreg_in_insn): Likewise.
            (general_scalar_chain::convert_reg): Adjust signature.
            * config/i386/i386-features.c (scalar_chain::add_insn): Do not
            iterate over all defs of a reg.
            (general_scalar_chain::replace_with_subreg): Remove.
            (general_scalar_chain::replace_with_subreg_in_insn): Likewise.
            (general_scalar_chain::make_vector_copies): Populate defs_map,
            place copy only after defs that are used as vectors in the chai=
n.
            (general_scalar_chain::convert_reg): Emit a copy for a specific
            def in a specific instruction.
            (general_scalar_chain::convert_op): All reg uses are converted
here.
            (general_scalar_chain::convert_insn): Emit copies for scalar
            uses of defs here.  Replace uses with the copies we created.
            Replace and convert the def.  Adjust REG_DEAD notes, remove
            REG_EQUIV/EQUAL notes.
            (general_scalar_chain::convert_registers): Only handle copies
            into the chain here.=