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 910B938362EC; Fri, 16 Dec 2022 09:35:29 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 910B938362EC
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1671183329;
	bh=vL0Ep+VsDPHDvN2u4PAg83PzXDV3laPjJPTl5SIBSn0=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=mYtbmxggRgzBsGnCEel7DbcZdGE4TAJSZ2gk5MJGlAITKvmFjZxeJf0NQIzz6JmLX
	 1yUFFKAJJ25IarVn7R0fvChippQmuKIcWriL+d2mJ5nyH4998HuCsQSVHzI/oMNPRT
	 +H87Dg8uKjbK0R8KjMv6uJbQvLY/K0qWU3jrY5y0=
From: "amonakov at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/108140] ICE expanding __rbit
Date: Fri, 16 Dec 2022 09:35:29 +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: unknown
X-Bugzilla-Keywords: ice-on-valid-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: amonakov at gcc dot gnu.org
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: cc keywords component cf_gcctarget short_desc
Message-ID: <bug-108140-4-8R0TBojHuf@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-108140-4@http.gcc.gnu.org/bugzilla/>
References: <bug-108140-4@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=3D108140

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amonakov at gcc dot gnu.org
           Keywords|                            |ice-on-valid-code
          Component|c                           |middle-end
             Target|                            |aarch64-*-*
            Summary|tzcnt gives different       |ICE expanding __rbit
                   |result in debug vs release  |

--- Comment #4 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
When comment #0 says "this crashes at -O2", it means ICE in expand for the
'__rbit' intrinsic on this testcase, which is reproducible on 12.2 and trun=
k:

#include<stdio.h>
#include<arm_acle.h>
int main(int argc, char *argv[])
{=20=20=20=20=20=20=20
        unsigned long long input =3D argc-1;
        unsigned long long v =3D __clz(__rbit(input));
        printf("%d %d\n", argc, v >=3D 64 ? 123 : 456);
}

I've edited the bug title to reflect this.=