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 E8B5E3858425; Mon,  7 Aug 2023 12:59:09 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E8B5E3858425
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1691413149;
	bh=cfJ0NWcSfPsIyJsJ2GD8o00o9o1kK8P7NlxUnpUkfoc=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=hNK8tBKcmvf4s4AaW/MDG6vYCt1oNSxY1c0+3SQmEd2/BxpKN51vy8wtoyuX6HWMp
	 PJ8tJ95ywoGmb6M7dctal6/i3xhqrakwqh21o3Mb7I9e7e32ZQvrP6f/gnYXcaXtHS
	 qdZLU3hibvAyhnsmTqR7/vsdwp0QjfLrQqOA0dvU=
From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/110921] Relax _tzcnt_u32 support x86, all x86 arch
 support for this instrunction
Date: Mon, 07 Aug 2023 12:59:09 +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: 14.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: crazylht 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: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-110921-4-mIqcGnRWaq@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-110921-4@http.gcc.gnu.org/bugzilla/>
References: <bug-110921-4@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=3D110921

--- Comment #11 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to =E7=BD=97=E5=8B=87=E5=88=9A(Yonggang Luo) from comment #10)
> (In reply to Hongtao.liu from comment #9)
>=20
> > > Without `-mbmi` option, gcc can not compile and all other three compi=
ler
> > > can compile.
> >=20
> > As long as it keeps semantics(respect zero input), I think this is
> > acceptable.
>=20
> Yeap, it's acceptable, but consistence with Clang/MSVC/ICL would be bette=
r.
> That would makes the cross-platform code easier, besides, GCC also works =
for
> WIN32, that's needs GCC to be consistence with MSVC

Sorry for confusion, I meant generating codes like

f(int, int):                                 # @f(int, int)
        test    edi, edi
        je      .LBB0_2
        rep       bsf eax, edi
        ret
.LBB0_2:
        mov     eax, 32
        ret

w/o mbmi is acceptable as long as it respect zero input.=