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 E501E3857C61; Mon, 15 Mar 2021 10:21:38 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E501E3857C61
From: "unlvsur at live dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/99582] No intrinsics to access rcl or rcr instruction on
 x86_64
Date: Mon, 15 Mar 2021 10:21:38 +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: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: unlvsur at live 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-99582-4-NE7SRFdOID@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-99582-4@http.gcc.gnu.org/bugzilla/>
References: <bug-99582-4@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: Mon, 15 Mar 2021 10:21:39 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99582

--- Comment #2 from cqwrteur <unlvsur at live dot com> ---
(In reply to Richard Biener from comment #1)
> ROR can be open-coded, GCC tries hard to detect common patterns.
>=20
> RCR is difficult because it involves the carry flag and thus the carry
> producer
> would have to be explicit.  Or it would need to be an awkward intrinsic
> like
>=20
> __builtin_rcr ({unsigned, unsigned short, unsigned char} word, bool carry,
> unsigned amnt);
>=20
> and you'd need to hope the compiler can arrange 'carry' to be produced in
> the carry flag ...

so is that possible to __builtin_rcl and __builtin_rcr? I think a lot of
cryptography and multi-precision libraries need that for pow stuffs=