From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] add "xchg ax, reg" emulator test Date: Tue, 16 Mar 2010 14:56:28 +0200 Message-ID: <4B9F7FFC.8090704@redhat.com> References: <20100316124252.GD1365@redhat.com> <4B9F7EB2.9060004@redhat.com> <20100316125248.GE1365@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: mtosatti@redhat.com, kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:9868 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751470Ab0CPM4a (ORCPT ); Tue, 16 Mar 2010 08:56:30 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o2GCuU6Y004432 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 16 Mar 2010 08:56:30 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o2GCuTss027620 for ; Tue, 16 Mar 2010 08:56:29 -0400 In-Reply-To: <20100316125248.GE1365@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/16/2010 02:52 PM, Gleb Natapov wrote: >>> + MK_INSN(xchg_test1, "xchg %eax,%eax\n\t"); >>> >> AKA 'nop'. >> >> > Yep, but we still emulate it. > > And well too. Note that 'xchg eax, ebx' will clear the top 32-bits of rax and rbx, but 'xchg eax, eax' will not. -- error compiling committee.c: too many arguments to function