From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id CB7E83939C37; Fri, 29 Jan 2021 12:48:59 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CB7E83939C37 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/98884] Implement empty struct optimisations on ARM Date: Fri, 29 Jan 2021 12:48:59 +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: 11.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: jakub at gcc dot gnu.org 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 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: Fri, 29 Jan 2021 12:48:59 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D98884 --- Comment #4 from Jakub Jelinek --- Note, for ABI compatibility or incompatibility it might be better to check = what happens when some argument is passed after the empty structs. Because at l= east in some ABIs one could get away with just pretending the stack slots (or registers) are there even when they aren't actually allocated on the stack,= but one would need to have guarantees the callee e.g. will never modify those s= tack slots (in most ABIs the call argument stack slot are owned by the callee).=