From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 32D7E385842B; Mon, 13 Sep 2021 03:28:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 32D7E385842B From: "crazylht at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/102294] memset expansion is sometimes slow for small sizes Date: Mon, 13 Sep 2021 03:28:57 +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: 11.2.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: crazylht at gmail dot com 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: Mon, 13 Sep 2021 03:28:57 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102294 --- Comment #10 from Hongtao.liu --- (In reply to Bart Van Assche from comment #9) > Hmm ... isn't movups a floating-point instruction? I want to avoid floati= ng > point instructions since my understanding is that it is not allowed to use > these in kernel code. See e.g. > https://stackoverflow.com/questions/13886338/use-of-floating-point-in-the- > linux-kernel. then as pinski mentioned in #c1, -mno-sse is needed, i guess for clang case, xmm mov is also used which also shouldn't be available in kernel.=