linux-kernel - ARM assembly syntax (was Re: [patch 03/36] Hexagon: Add bitops support)

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]

Message-ID: <20110830211449.GC7047@codeaurora.org>
Date:	Tue, 30 Aug 2011 16:14:49 -0500
From:	"Linas Vepstas (Code Aurora)" <linas@...eaurora.org>
To:	Pavel Machek <pavel@....cz>
Cc:	Richard Kuo <rkuo@...eaurora.org>, linux-kernel@...r.kernel.org,
	linux-hexagon@...r.kernel.org
Subject: ARM assembly syntax  (was Re: [patch 03/36] Hexagon: Add bitops
 support)

On Fri, Aug 26, 2011 at 10:34:10PM +0200, Pavel Machek wrote:
> Hi!
> 
> > +	__asm__ __volatile__ (
> > +	"	{R10 = %1; R11 = asr(%2,#5); }\n"
> > +	"	{R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
> > +	"1:	R12 = memw_locked(R10);\n"
> > +	"	{ P0 = tstbit(R12,R11); R12 = clrbit(R12,R11); }\n"
> > +	"	memw_locked(R10,P1) = R12;\n"
> > +	"	{if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
> 
> Nice assembly syntax, btw. I can only wish architectures such as arm
> used something as readable...

Yes, I, too, was very pleasantly surprised when I first saw this.

Of course, one *could* alter binutils to accept something similar
for ARM, and then alter gcc to spit it out. Whether anyone would use
this isn't clear .. and I can already almost hear certain maintainers
telling us how much of a bad idea this is from the maintainership
point-of-view ....

--linas

-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
--
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/