From owner-freebsd-current Tue Mar 16 21:29: 9 1999 Delivered-To: freebsd-current@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 86FEF14F24 for ; Tue, 16 Mar 1999 21:29:07 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id VAA24119; Tue, 16 Mar 1999 21:28:47 -0800 (PST) (envelope-from dillon) Date: Tue, 16 Mar 1999 21:28:47 -0800 (PST) From: Matthew Dillon Message-Id: <199903170528.VAA24119@apollo.backplane.com> To: Luoqi Chen Cc: current@FreeBSD.ORG Subject: Re: VM86 assembly code problem References: <199903170413.XAA14900@lor.watermarkgroup.com> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :There're a couple of places in swtch.s where code looks like this, : :#ifdef VM86 : btrl %esi, _private_tss : je 3f : ... :3: :#endif : :The conditional jump statement doesn't seem right, according to manual, :btrl instruction modifies CF flag but not Z, so the jump should be jae/jb :instead of je/jne. Could anyone confirm this? : :-lq btrl only effects the Carry. The VM86 code looks wrong to me, though there is an outside chance that it is doing a conditional jump based on something that occured prior to the btrl. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message