| 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
| ||
|
Message-ID: <m23a9deb87.fsf@igel.home> Date: Fri, 03 Jul 2009 22:57:12 +0200 From: Andreas Schwab <schwab@...ux-m68k.org> To: Brad Boyer <flar@...andria.com> Cc: kernel mailz <kernelmailz@...glemail.com>, linuxppc-dev@...abs.org, gcc-help@....gnu.org, linux-kernel@...r.kernel.org Subject: Re: Inline assembly queries [2] 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 gcc documentation says Z is obsolete.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). It should only be used together with the %y operand modifier, which makes sure that the first register is never 0. If the 'm' constraint were used the operand could contain a pre-in/decrement operation, and without %U the side effect would be lost. Andreas. -- Andreas Schwab, schwab@...ux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." -- 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/
Powered by blists - more mailing lists