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 663573858C39; Tue,  7 May 2024 12:05:22 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 663573858C39
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1715083522;
	bh=hmBYAP1zSH0MXAK09+p3oweTWoMmKeVL4iE/dLB0/Ng=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=USz7oqV8pHAqVpojLn64cY9xb3hu7yiHpjia+5BfuzEIj1+K5A9U0WESLV9KyIVTa
	 URzvhSw8mCB+OM8uQz7kdjL1qmcwvKdZMZuvjjALM5iPur0yniXETqhFsupLbtFjwF
	 ODhLgN7FaCCiijYe51FaoOB2vWzdZdHtA3pkHymA=
From: "hubicka at ucw dot cz" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/114959] incorrect TBAA for drived types
 involving function types
Date: Tue, 07 May 2024 12:05:21 +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: 14.0
X-Bugzilla-Keywords: alias, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: hubicka at ucw dot cz
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-114959-4-BklBO6V3ZZ@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-114959-4@http.gcc.gnu.org/bugzilla/>
References: <bug-114959-4@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=3D114959

--- Comment #4 from Jan Hubicka <hubicka at ucw dot cz> ---
>=20
> I think function types are somewhat special in that they do not denote
> objects in the classical sense.  They are also most complex and probably
> target-dependent to handle.
>=20
> Note there's LTO where we glob all pointers to a single equivalence class
> because of Fortran where C_PTR inter-operates with all pointer types.  But

We special case void * to alias with all other pointer types and look
through pointers in alias.cc, so accesses through pointers are not
necessarily fully globbed.

I plan to look into unglobbing pointers when Fortran C_PTR can not clash
since this is relatively important piece of TBAA information.

Honza=