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 BC5FD385842A; Thu,  2 Mar 2023 19:05:14 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BC5FD385842A
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1677783914;
	bh=5R4Ax0T8Fn2C62zvSnZJn5hZ+5Ak/YxRf5l0VZ0nqco=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=V2NQ0UB5hH3k3OJCXdPihWz6iY05EIND23B0mvIIF0e+5/H889wmsOo9qMIhBYDWN
	 6N96asM4Ww1oDXZCLkXVOgKFT0IyZzv4rFvJMuwR+IOUtLcKFi6hxPFhwKED8H71oS
	 wgFX2hsfpnGaB8qx76tIWYBN6cltikrJC7zbx7O4=
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/97553] [missed optimization] constexprness not noticed when
 UBsan enabled
Date: Thu, 02 Mar 2023 19:05:12 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 10.2.0
X-Bugzilla-Keywords: missed-optimization
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: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-97553-4-f4UUNpgBxY@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-97553-4@http.gcc.gnu.org/bugzilla/>
References: <bug-97553-4@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=3D97553

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:5425159d176a7a92afc932cbb22d8822667099c4

commit r13-6422-g5425159d176a7a92afc932cbb22d8822667099c4
Author: Patrick Palka <ppalka@redhat.com>
Date:   Thu Mar 2 14:04:50 2023 -0500

    c++: more mce_false folding from cp_fully_fold_init [PR108243]

    We should also fold the overall initializer passed to cp_fully_fold_init
    with mce_false, which allows folding of the copy-initialization of
    'a1' in the below testcase (the initializer here is an AGGR_INIT_EXPR).

    Unfortunately this doesn't help with direct- or default-initialization
    because we don't call cp_fully_fold_init in that case, and even if we
    did the initializer in that case is expressed as a bare CALL_EXPR
    instead of an AGGR_INIT_EXPR, which cp_fully_fold_init can't really
    fold.

            PR c++/108243
            PR c++/97553

    gcc/cp/ChangeLog:

            * cp-gimplify.cc (cp_fully_fold): Add an internal overload that
            additionally takes and propagate an mce_value parameter, and
            define the existing public overload in terms of it.
            (cp_fully_fold_init): Pass mce_false to cp_fully_fold.

    gcc/testsuite/ChangeLog:

            * g++.dg/opt/is_constant_evaluated3.C: New test.=