From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A74923858C83; Mon, 5 Sep 2022 09:58:18 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A74923858C83 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1662371898; bh=k0UDO6e25oUGSKnkRAY2jGWila1nfsuvdK2thFEDDFo=; h=From:To:Subject:Date:In-Reply-To:References:From; b=bXXesaq2r7lAcm31VEuLvAoinN6uB+PTEEyI/dPKPXPX77XDuxQG2ssOMgGru6yeS 8MjP7f3eqj0ZNKlk2+ET9VDNmYQRFC6pb3LNigWmXI14yPn2OfEFU1awDHPAj9ic9O 2gOOUxOOmaTZ6mkNfbZ+vNAxA4o/ZeWa4WHoQgOI= From: "rguenther at suse dot de" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/106833] Handle OPAQUE_TYPE in gimple_canonical_types_compatible_p Date: Mon, 05 Sep 2022 09:58:18 +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: 13.0 X-Bugzilla-Keywords: ice-checking X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenther at suse dot de 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: 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=3D106833 --- Comment #6 from rguenther at suse dot de --- On Mon, 5 Sep 2022, linkw at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106833 >=20 > --- Comment #4 from Kewen Lin --- > (In reply to Richard Biener from comment #2) > > (In reply to Kewen Lin from comment #1) > > > IMHO this is an omission when we were adding supports for opaque type= , const > > > __vector_quad and __vector_quad should be taken as > > > canonical_types_compatible. > > >=20 > > > I wonder if we can simply take it just like what it handles for > > > "Non-aggregate types", for example: > > >=20 > > > diff --git a/gcc/tree.cc b/gcc/tree.cc > > > index 2f488e4467c..555e96c59d5 100644 > > > --- a/gcc/tree.cc > > > +++ b/gcc/tree.cc > > > @@ -13510,6 +13510,7 @@ gimple_canonical_types_compatible_p (const_tr= ee t1, > > > const_tree t2, > > > || TREE_CODE (t1) =3D=3D VECTOR_TYPE > > > || TREE_CODE (t1) =3D=3D COMPLEX_TYPE > > > || TREE_CODE (t1) =3D=3D OFFSET_TYPE > > > + || TREE_CODE (t1) =3D=3D OPAQUE_TYPE > > > || POINTER_TYPE_P (t1)) > > > { > > > /* Can't be the same type if they have different recision. */ > > >=20 > > > Or adding one default hook which does the similar thing, and then if = one > > > target needs some target specific checks on its opaque type, one spec= ific > > > hook can be provided. > >=20 > > I'm quoting tree.def, emphasis mine: > >=20 > > /* This is for types that will use MODE_OPAQUE in the back end. They a= re > > meant > > to be able to go in a register of some sort but are _EXPLICITLY NOT = TO BE > > CONVERTED_ or operated on like INTEGER_TYPE. They will have size and > > alignment information only. */ > > DEFTREECODE (OPAQUE_TYPE, "opaque_type", tcc_type, 0) > >=20 >=20 > Good point! My fault, I didn't read through this documentation. It seems = to say > no conversions are allowed on it? (either explicit or implicit?) >=20 > > so why should we care about special-casing them? The target should hav= e set > > TYPE_CANONICAL appropriately if necessary, why didn't it? Btw, 'const' > > qualification should go into the type variant chain (well, for "normal" > > types), where TYPE_MAIN_VARIANT is the unqualified type variant.=20 > > TYPE_CANONICAL > > shouldn't come into play here. > >=20 >=20 > With flag_checking on, while doing lto_fixup_state, verify_type will check > every tree type, it further checks with verify_type_variant, then fails w= ith > gimple_canonical_types_compatible_p (t, tv, false). (here trust_type_can= onical > is false). Ah, that special "mode". I think verify_types shouldn't do anything for OPAQUE_TYPES or alternatively trust the targets setup of TYPE_MAIN_VARIANT/TYPE_CANONICAL. Maybe verify TYPE_CANONICAL and TYPE_MAIN_VARIANT are also OPAQUE_TYPE. So the solution should be fully inside verify_type. > I think this is a common issue for any cv-qualified opaque type when lto > checking is on. >=20 > In this case,=20 > t1: > const __vector_quad=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 >=20 > t2: > __vector_quad >=20 > Both TYPE_MAIN_VARIANT and both TYPE_CANONICAL is exactly the same here (= all > equivalent to t2). >=20 > > Btw, the whole idea of "opaque" is a hack and it seems to backfire now? >=20 > Not sure, it had some adjustments with r11-5222 before, I thought we need= some > similar for this issue.=