From mboxrd@z Thu Jan 1 00:00:00 1970 From: mans@mansr.com (=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=) Date: Tue, 24 Nov 2015 12:10:02 +0000 Subject: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions In-Reply-To: <20151124104225.GA8644@n2100.arm.linux.org.uk> (Russell King's message of "Tue, 24 Nov 2015 10:42:26 +0000") References: <1448068997-26631-1-git-send-email-sboyd@codeaurora.org> <20151124001306.GI19156@codeaurora.org> <20151124085349.GQ19156@codeaurora.org> <4485320.CGMJdfZLya@wuerfel> <20151124104225.GA8644@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Russell King - ARM Linux writes: > 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. If the compiler accepts the option but doesn't actually emit any div instructions, is there any real harm? -- M?ns Rullg?rd mans at mansr.com