From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 017F23858CDB; Wed, 1 May 2024 01:00:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 017F23858CDB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1714525241; bh=Zt+naHIcgSKgJHMaHzHrUNpEvg3CO/HRS9Eay6lTLXw=; h=From:To:Subject:Date:In-Reply-To:References:From; b=vRXJZNKkOylknp6HDv9F41LR5yyBeB53HeKqeTM/w0o80zs6J7scWgubmTYHNCkFH Qr0rRuo/5k/jRbM6HMfbPxYEiywhCbjJx5Qq+3EOUPzLiTk7f4VLhX84eN0Av/TeRO saYiDQGYvvD1XX0T2BdQO7W7OVz22ZlfgkHS0/WU= From: "sjames at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/114872] [13/14/15 Regression] Miscompilation with -O2 after commit r13-8037 Date: Wed, 01 May 2024 01:00:39 +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: 13.2.1 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: sjames 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: 13.3 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114872 --- Comment #8 from Sam James --- element.i is unfortunatley huge. It's hard to analyse things without a standalone testcase, but it's even harder without _something_ one can run. I'd suggest: 1) giving instructions to reproduce the crash assuming someone knows nothing about sage and cython; 2) taking sage and cannibalising it (first to directly call `libgap.AbelianGroup(0,0,0)`, then you can cut things down with lots of removals + gdb so that the important caller of Py_XDECREF gets passed with = the same args; it's harder if there's a lot of state involved though, of course) 3) build element.i with -fdump-tree-all -fdump-unnumbered -fdump-noaddr (can also try e.g. -da, see https://gcc.gnu.org/onlinedocs/gcc/Developer-Options.html) at the bad commit and before, and diff the produced dumps, and show us the *first* dump which differs between the two=