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 81184385842C; Wed, 23 Feb 2022 13:42:29 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 81184385842C
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/104644] [12 Regression] ICE: SIGSEGV
 (infinite recursion in fold_binary_loc / fold_build2_loc /
 generic_simplify_NE_EXPR)
Date: Wed, 23 Feb 2022 13:42:29 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: ice-on-valid-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P1
X-Bugzilla-Assigned-To: jakub at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-104644-4-iC1MH526wF@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-104644-4@http.gcc.gnu.org/bugzilla/>
References: <bug-104644-4@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: Wed, 23 Feb 2022 13:42:29 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104644

--- Comment #6 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:fdc46830f1b793dc791099acfadc3f0f8cc24c0e

commit r12-7361-gfdc46830f1b793dc791099acfadc3f0f8cc24c0e
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Feb 23 13:47:01 2022 +0100

    middle-end/104644 - recursion with bswap match.pd pattern

    The following patch avoids infinite recursion during generic folding.
    The (cmp (bswap @0) INTEGER_CST@1) simplification relies on
    (bswap @1) actually being simplified, if it is not simplified, we just
    move the bswap from one operand to the other and if @0 is also INTEGER_=
CST,
    we apply the same rule next.

    The reason why bswap @1 isn't folded to INTEGER_CST is that the INTEGER=
_CST
    has TREE_OVERFLOW set on it and fold-const-call.cc predicate punts in
    such cases:
    static inline bool
    integer_cst_p (tree t)
    {
      return TREE_CODE (t) =3D=3D INTEGER_CST && !TREE_OVERFLOW (t);
    }
    The patch uses ! modifier to ensure the bswap is simplified and
    extends support to GENERIC by means of requiring !EXPR_P which
    is not perfect but a conservative approximation.

    2022-02-22  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/104644
            * doc/match-and-simplify.texi: Amend ! documentation.
            * genmatch.cc (expr::gen_transform): Code-generate ! support
            for GENERIC.
            (parser::parse_expr): Allow ! for GENERIC.
            * match.pd (cmp (bswap @0) INTEGER_CST@1): Use ! modifier on
            bswap.

            * gcc.dg/pr104644.c: New test.

    Co-Authored-by: Jakub Jelinek <jakub@redhat.com>=