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 B76883858C00; Fri, 11 Aug 2023 21:23:13 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B76883858C00
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1691788993;
	bh=TTSB8cMsqkfI+mKDvYEHq9atcKMr8loKWPzG6lpW7tY=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=uzhwUTG3dXwa3rlhJyB55EmHsHqAAoWO6eeu1Xtv876fILjx5cE+8HaeqFZyP2Tyh
	 VqHOzCmf5ylM9JWYNDra9LQcRlvJ5nfcoa+3BQ3heOYu38QpoeIN3GG7G6aEbRPinY
	 EBYrjURvMydxPg1FzxIjU1yAD06pJ11HiRrTMm3A=
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/109678] [13/14 Regression] exponential time behavior on
 std::variant
Date: Fri, 11 Aug 2023 21:23:12 +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: 13.0
X-Bugzilla-Keywords: compile-time-hog, memory-hog
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Resolution: FIXED
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: jason at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 13.2
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-109678-4-ktk36x1ins@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-109678-4@http.gcc.gnu.org/bugzilla/>
References: <bug-109678-4@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=3D109678

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:d3088f0ed25fe7200fd657b70cb5af53139b0193

commit r13-7713-gd3088f0ed25fe7200fd657b70cb5af53139b0193
Author: Jason Merrill <jason@redhat.com>
Date:   Mon May 1 17:41:44 2023 -0400

    c++: std::variant slow to compile [PR109678]

    Here, when dealing with a class with a complex subobject structure, we
would
    try and fail to find the relevant FIELD_DECL for an empty base before
giving
    up.  And we would do this at each level, in a combinatorially problemat=
ic
    way.  Instead, we should check for an empty base first.

            PR c++/109678

    gcc/cp/ChangeLog:

            * constexpr.cc (cxx_fold_indirect_ref_1): Handle empty base fir=
st.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp1z/variant1.C: New test.=