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 0C0AA3858034; Thu, 23 Nov 2023 19:04:03 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0C0AA3858034
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1700766244;
	bh=yIn9zVkBQfvHD+blPDcH7oaUMo+rfy8aZ8XbU8TClow=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=DRTz0A/o5etKb+Jo7Il5ylNYu5s0/NdmFSOkPHYxM915RlFoGL7m/8JFPY7w2pyoX
	 1t9S5qZMYly5OwkpbT3bKsKXNAhI6FrPatM+hBe12V6D9tvhu0WTdGOKgMZbPvY6Wr
	 vNJsIBofLeeG9+cnTRecYtClf23WulMU3dbjFSD8=
From: "post+gcc at ralfj dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/32667] block copy with exact overlap is expanded as
 memcpy
Date: Thu, 23 Nov 2023 19:04:02 +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: 4.2.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: post+gcc at ralfj dot de
X-Bugzilla-Status: NEW
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-32667-4-ztZsFcraGn@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-32667-4@http.gcc.gnu.org/bugzilla/>
References: <bug-32667-4@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=3D32667

--- Comment #43 from post+gcc at ralfj dot de ---
That is not my reading of the standard, but absent a proper (formal,
mathematical) spec I guess it is hard to tell.

With your reading, "if ((uintptr_t)src =3D=3D 0x400400)" is UB, since chang=
ing the
"src" argument to a different copy located at that address would change the
execution. I strongly doubt that is the intent of the standard.=