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 5CF3B3858D33; Fri, 12 Apr 2024 02:47:02 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5CF3B3858D33
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1712890022;
	bh=eXrClVo7EMMM7fzU77S82ECR5O36kCMLwYMGCbQ93BA=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=IDSLN9ZBrmTRMN5WRXxqvCJl6gqGuMGrkW12rg8JiSnlMAqKnxEZ31qwUNPAIJuGn
	 DNjMQ+pSpSuDqM/41U2eEwfvFs/uF7Tn2j89ytxYGERmF+YH5dhsuL/kvlHIqvUpHi
	 bHLfW5XYsLfKLMIsygMwHBiDukr18+5ayNXHkGAA=
From: "lin1.hu at intel dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/114700] Front-end optimization generates wrong code
 with -ftrapv.
Date: Fri, 12 Apr 2024 02:47:02 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: lin1.hu at intel dot com
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-114700-4-FbqLB5t0Tl@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-114700-4@http.gcc.gnu.org/bugzilla/>
References: <bug-114700-4@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=3D114700

--- Comment #2 from lin1.hu at intel dot com ---
(In reply to Andrew Pinski from comment #1)
> Gcc's trapv is known not always to work correctly.
>=20
> Try -fsanitize=3Dundefined instead.

Thanks, it solves the problem to some extent. But c is eliminated, I think =
c -
y may cause signed overflow, c

https://godbolt.org/z/Wbzx5Edsj=