From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20183 invoked by alias); 8 Mar 2013 12:12:37 -0000 Received: (qmail 19900 invoked by uid 48); 8 Mar 2013 12:11:26 -0000 From: "dwmw2 at infradead dot org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/55177] missed optimizations with __builtin_bswap Date: Fri, 08 Mar 2013 12:12:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: dwmw2 at infradead dot org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: ebotcazou at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2013-03/txt/msg00660.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55177 --- Comment #9 from David Woodhouse 2013-03-08 12:11:24 UTC --- This is now enabled in the Linux kernel. Core patch: http://git.kernel.org/linus/cf66bb93 (in v3.8 but does nothing there) x86: http://git.kernel.org/linus/83a57a4d (will be in v3.9) PowerPC: http://git.kernel.org/linus/fe3955cb (will be in v3.9) There's an ARM patch which looks like it missed the boat for 3.9 but should hopefully be in v3.10: https://lkml.org/lkml/2013/2/22/475 On ARM where we have no load-and-swap or store-and-swap primitives we are already seeing a tiny win. But fixing up more of the missing optimisations would be good.