linux-kernel - Re: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 22 Nov 2015 20:03:26 +0000
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Peter Maydell <peter.maydell@...aro.org>,
	Måns Rullgård <mans@...sr.com>,
	Nicolas Pitre <nico@...xnic.net>,
	"linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>,
	Stephen Boyd <sboyd@...eaurora.org>,
	lkml - Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	arm-mail-list <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library
 functions

On Sun, Nov 22, 2015 at 08:58:08PM +0100, Arnd Bergmann wrote:
> does it work with -mcpu=cortex-a15?  I've tried crosstool as versions
> 2.23.52.20130913, 2.24.0.20141017 and 2.25.51.20150518, and they
> all seem to behave as expected, failing with -mcpu=cortex-a9 and
> marvell-pj4 but succeeding with -mcpu=cortex-a15 or marvell-pj4+idiv.

Appears not:

root@...ox:~# gcc -O2 -o idiv idiv.c -Wa,-mcpu='cortex-a15+idiv' -marm
/tmp/ccSovg32.s: Assembler messages:
/tmp/ccSovg32.s:32: Error: selected processor does not support ARM mode `udiv ip,r5,r4'
root@...ox:~# gcc -O2 -o idiv idiv.c -Wa,-mcpu='cortex-a15+idiv' -mthumb
/tmp/cchbT3EE.s: Assembler messages:
/tmp/cchbT3EE.s:36: Error: selected processor does not support Thumb mode `udiv r6,r5,r4'

Same without the +idiv.

> I've also found some /proc/cpuinfo output to cross-reference SoCs
> to their core names.
> 
> 		variant	part	revision	name		features
> mmp2:		0	0x581	5		PJ4		idivt
> dove:		0	0x581	5		PJ4		idivt

Yes, that agrees with my dove.

-- 
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@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/