Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!ut-sally!im4u!oakhill!davet From: davet@oakhill.UUCP (Dave Trissel) Newsgroups: comp.sys.m68k Subject: Re: ADDA.L (SP)+,SP (68020) Message-ID: <1052@oakhill.UUCP> Date: Wed, 2-Dec-87 16:00:00 EST Article-I.D.: oakhill.1052 Posted: Wed Dec 2 16:00:00 1987 Date-Received: Sat, 5-Dec-87 17:41:57 EST References: <407@palladium.UUCP> Reply-To: davet@oakhill.UUCP (Dave Trissel) Organization: Motorola Inc. Austin, Tx Lines: 21 Keywords: MC68020 In article <407@palladium.UUCP> nw@palladium.UUCP (Neil Webber) writes: >Is the following instruction sequence an "undefined" operation? > > ADDA.L (SP)+,SP > No, this is well defined. The stack register value is first incremented by four and then totally replaced by the memory source data. > MOVES.x An,(An)+ > or > MOVES.x An,-(An) > > where An is the same address register for both source and destination > operand is an undefined operation. > >Is this meant to be a generic warning or only for MOVES? ... This warning only pertains to the MOVES instruction. -- Dave Trissel - Motorola Austin - ihnp4!ut-sally!im4u!oakhill!davet