From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions Date: Tue, 24 Nov 2015 10:42:26 +0000 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-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <4485320.CGMJdfZLya@wuerfel> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Arnd Bergmann Cc: Nicolas Pitre , Peter Maydell , =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= , "linux-arm-msm@vger.kernel.org" , Daniel Lezcano , Stephen Boyd , lkml - Kernel Mailing List , Steven Rostedt , Christopher Covington , linux-arm-kernel@lists.infradead.org List-Id: linux-arm-msm@vger.kernel.org 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.