From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] x86: fix variable_test_bit() asmconstraints Date: Fri, 14 Mar 2008 13:57:28 +0000 Message-ID: References: <47DA90EE.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <47DA90EE.76E4.0078.0@novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 14/3/08 13:51, "Jan Beulich" wrote: >> because at least I'm certain that works. Same for 'asm volatile'. We've had >> various problems with the bitops before, and I just want the darn things to >> work! > > Okay, if you feel that way then I guess I won't propose changing it, > at the expense of slightly worse code generation. Frankly I'm scared to change it for the minuscule benefit we would derive from it. Regarding your other reply: I would actually be happy to change the bitops to work with longs only. I suspect, and would need to have demonstrated otherwise, that supporting bitops on arbitrary-width fields down to the instruction level is not really worthwhile. Either way, I accept that what we do now is dubious at best. -- Keir