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 E5E063939C27; Wed, 29 Apr 2020 06:51:31 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E5E063939C27
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1588143091;
 bh=KXz8+GvdBLoiKg2tDpubc7wzHIBS5t1HrlwYlvdHtHM=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=qEx0RWxNEoZ50v8a8ZrPtEbVz5YrYDXWGKaH7WqJdnOS8VPNKVtHSpdzuL+AZHXsv
 OSFusZvbgEV3KmG2Iv1UC/HLImiUFqzqy5k+vgJy/LZIOsjGz5lj0QrT+Vr/NB1Vx0
 9ZU467qW0yWOe8mVQllJqFDHn1w36wsF/f2VzK9s=
From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/94838] Failure to optimize out useless zero-ing after
 register was already zero-ed
Date: Wed, 29 Apr 2020 06:51:31 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 10.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: gabravier 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: 
Message-ID: <bug-94838-4-t0OerwxCMU@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-94838-4@http.gcc.gnu.org/bugzilla/>
References: <bug-94838-4@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: Wed, 29 Apr 2020 06:51:32 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94838

--- Comment #3 from Gabriel Ravier <gabravier at gmail dot com> ---
This also occurs on i68* :=20

f(bool, int*):
  xor eax, eax ; Already 0
  cmp BYTE PTR [esp+4], 0
  je .L1
  mov eax, DWORD PTR [esp+8] ; Could use different caller-saved register su=
ch
as ecx or edx
  mov eax, DWORD PTR [eax]
  test eax, eax
  setne al
  movzx eax, al ; This could then be avoided since eax would already be 0
.L1:
  ret=