Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756770Ab3JNPll (ORCPT ); Mon, 14 Oct 2013 11:41:41 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:41123 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756254Ab3JNPlk (ORCPT ); Mon, 14 Oct 2013 11:41:40 -0400 Date: Mon, 14 Oct 2013 16:40:44 +0100 From: Russell King - ARM Linux To: Jiang Liu Cc: Steven Rostedt , Catalin Marinas , Will Deacon , Sandeepa Prabhu , Jiang Liu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/7] Optimize jump label implementation on ARM64 Message-ID: <20131014154044.GR25034@n2100.arm.linux.org.uk> References: <1381675827-1610-1-git-send-email-liuj97@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1381675827-1610-1-git-send-email-liuj97@gmail.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 813 Lines: 15 On Sun, Oct 13, 2013 at 10:50:20PM +0800, Jiang Liu wrote: > To enable this feature, your toolchain must support "asm goto" extension > and "%c" constraint extesion. Current GCC for AARCH64 doesn't support > "%c", so you need a GCC patch similiar to this: Oh god, not that again. I've no idea why ARM stuff has such a problem with supporting this very useful "%c" GCC constraint. Aarch32 didn't for ages consequently we now have horrid hacks around it in the kernel source because our compilers suck. Seems Aarch64 is doomed to repeat the same stupid mistakes. :( -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/