Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279AbbKXKnS (ORCPT ); Tue, 24 Nov 2015 05:43:18 -0500 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:52864 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753315AbbKXKmj (ORCPT ); Tue, 24 Nov 2015 05:42:39 -0500 Date: Tue, 24 Nov 2015 10:42:26 +0000 From: Russell King - ARM Linux To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, Stephen Boyd , Nicolas Pitre , Peter Maydell , =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= , "linux-arm-msm@vger.kernel.org" , Daniel Lezcano , lkml - Kernel Mailing List , Steven Rostedt , Christopher Covington Subject: Re: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions Message-ID: <20151124104225.GA8644@n2100.arm.linux.org.uk> References: <1448068997-26631-1-git-send-email-sboyd@codeaurora.org> <20151124001306.GI19156@codeaurora.org> <20151124085349.GQ19156@codeaurora.org> <4485320.CGMJdfZLya@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4485320.CGMJdfZLya@wuerfel> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1044 Lines: 23 On Tue, Nov 24, 2015 at 11:38:53AM +0100, Arnd Bergmann wrote: > I suggested using -mcpu=cortex-a15 because there are old gcc versions > that don't know about -march=armv7ve or -march=armv7-a+idiv yet, but > that do understand -mcpu=cortex-a15. That's not all. The bigger problem is that there are toolchains out there which accept these options, but do _not_ support IDIV in either ARM or Thumb mode. I'm afraid that makes it impossible to add this feature to the mainline kernel in this form: we need to run a test build to check that -march=armv7ve or what-not really does work through both GCC and GAS. Given that Ubuntu 14.04 LTS suffers with this, it's something that must be resolved. -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- 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/