From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A5B0D384240B; Wed, 29 Jul 2020 16:40:55 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A5B0D384240B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1596040855; bh=gTa/hH5ejGe6FdH6EmDKtnGHCugdHW8gHwNSKbBmT9k=; h=From:To:Subject:Date:In-Reply-To:References:From; b=F/QyDSgsqxNbZKu0hANlZ+mNrNIOy+BofxF08/+XKJzQKtErIjJ73w9HbIeIQczRY oP8fbeCUZ3Cr3TXXSbWZdWhufw9rG03Jb4km6URRSi2D4sG0fo/HXf7hxsX9GD/aEG Nc0JB5JQQwLDVqjsNLJ1pd76oMfkEwC4W7bX7uho= From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/96377] [10/11 Regression] GCC 10.2/11 doesn't build Linux kernel anymore Date: Wed, 29 Jul 2020 16:40:55 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 10.0 X-Bugzilla-Keywords: rejects-valid X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 10.3 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 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Jul 2020 16:40:55 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D96377 --- Comment #2 from Jakub Jelinek --- This dates back to https://gcc.gnu.org/legacy-ml/gcc-patches/2004-06/msg00288.html Dunno, do we want to never strip attributes from VECTOR_TYPEs and only strip them that way from non-VECTOR_TYPEs? Or only strip some attributes and keep others? Or just add a if (t1 =3D=3D t2) return t1; before the attribute stripping (= perhaps for VECTOR_TYPEs only)? Note, due to the typedef __Uint8x16_t uint8x16_t; on this testcase t1 and t2 are equal and are the typedef file, and because they are unqualified, we do= n't use TYPE_MAIN_VARIANT (which is the __Uint8x16_t type). What is the desirable behavior for the common type if one is the aarch64 specific vector and the other generic vector with the same mode? The C++ behavior for vector types in cp_common_type is that it will merge attributes from both types, and if one is TYPE_UNSIGNED, pick that one, otherwise pick the other one. So in that case the ARM specific vector type wins. I must say I'm surprised that the 10.2 version of the patch also matters, perhaps the FE isn't using the target hook to compare attributes, but rather just compares TYPE_MAIN_VARIANT or something similar to determine if the initializer is initializing a whole vector or an element of the vector.=