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 3B941386C58A; Thu, 14 Mar 2024 16:39:28 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3B941386C58A
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1710434368;
	bh=eUGOeYTksWhGMcirRraL29jXAwHjC2W5d/Ob6kLPdMk=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=OU7Ik+hEDZIW82i5h1N71sLP4PzmsnSt84KktNeNnlqNwVlWbtPW4YvIrQJoPzHef
	 VcsgeNu+BElMteXIggaKFJFdUu3VjcuG2MYX/+w/80mn7M3pxr3zMcFsGMed2MKRUT
	 7iNKqAf35XqP7ZZ5jUg4JXjUnD3WtyiftIp60Ppg=
From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug ipa/113907] [11/12/13/14 regression] ICU miscompiled since on
 x86 since r14-5109-ga291237b628f41
Date: Thu, 14 Mar 2024 16:39:27 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: ipa
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: hubicka at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P1
X-Bugzilla-Assigned-To: hubicka at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 14.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-113907-4-KL1I3gahpA@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-113907-4@http.gcc.gnu.org/bugzilla/>
References: <bug-113907-4@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=3D113907

--- Comment #59 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
just to explain what happens in the testcase.  There is test and testb. They
are almost same:

int
testb(void)
{
  struct bar *fp;
  test2 ((void *)&fp);
  fp =3D NULL;
  (*ptr)++;
  test3 ((void *)&fp);
}
the difference is in the alias set of FP. In one case it aliases with the
(*ptr)++ while in other it does not.  This makes one function to have jump
function specifying aggregate value of 0 for *fp, while other does not.

Now with LTO both struct bar and foo becomes compatible for TBAA, so the
functions gets merged and the winning variant has the jump function specify=
ing
aggregate 0, which is wrong in the context code is invoked.=