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 0BF0C3858408; Mon, 28 Feb 2022 07:03:13 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0BF0C3858408
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/104686] [12 Regression] Huge compile-time regression
 building SPEC 2017 538.imagick_r with -march=skylake
Date: Mon, 28 Feb 2022 07:03:12 +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: 12.0
X-Bugzilla-Keywords: compile-time-hog, ra
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit 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: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-104686-4-pS0O1rUAXj@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-104686-4@http.gcc.gnu.org/bugzilla/>
References: <bug-104686-4@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, 28 Feb 2022 07:03:13 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104686

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:a8250bbaeb2e8250c20db477fe67fd085214be7c

commit r12-7401-ga8250bbaeb2e8250c20db477fe67fd085214be7c
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Feb 25 14:19:44 2022 +0100

    rtl-optimization/104686 - speed up conflict iteration

    The following replaces

           /* Skip bits that are zero.  */
           for (; (word & 1) =3D=3D 0; word >>=3D 1)
             bit_num++;

    idioms in ira-int.h in the attempt to speedup
update_conflict_hard_regno_costs
    which we're bound on in PR104686.  The trick is to use ctz_hwi here
    which should pay off even with dense bitmaps on architectures that
    have HW support for this.

    For the PR in question this speeds up compile-time from 31s to 24s for
    me.

    2022-02-25  Richard Biener  <rguenther@suse.de>

            PR rtl-optimization/104686
            * ira-int.h (minmax_set_iter_cond): Use ctz_hwi to elide loop
            skipping bits that are zero.
            (ira_object_conflict_iter_cond): Likewise.=