linux-kernel - Re: Inline assembly queries [2]

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:	Mon, 6 Jul 2009 08:56:27 +0200
From:	Gabriel Paubert <paubert@...m.es>
To:	Andreas Schwab <schwab@...ux-m68k.org>
Cc:	Brad Boyer <flar@...andria.com>, gcc-help@....gnu.org,
	linuxppc-dev@...abs.org, linux-kernel@...r.kernel.org,
	kernel mailz <kernelmailz@...glemail.com>
Subject: Re: Inline assembly queries [2]

On Fri, Jul 03, 2009 at 10:57:12PM +0200, Andreas Schwab wrote:
> Brad Boyer <flar@...andria.com> writes:
> 
> > On Fri, Jul 03, 2009 at 12:14:41PM +0530, kernel mailz wrote:
> >> b. using m or Z  with a memory address. I tried replacing m/Z but no change
> >> Is there some guideline ?
> >> gcc documentation says Z is obsolete. Is m/Z replaceable ?
> >
> > No idea. I don't remember ever seeing 'Z' used in anything. Maybe somebody
> > else remembers what it used to mean.
> 
> The 'Z' constraint is required for a memory operand for insns that don't
> have an update form (which would be selected by the %U modifier).  

Hmmm, I believed that it was for instructions that only have an indexed
form (all Altivec, byte reverse, and l?arx/st?cx for atomic operations).

Of course none of these instructions have an update form, but they don't
have an offset encoded in the instruction either.

	Gabriel
--
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/