Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!cornell!uw-beaver!teknowledge-vaxc!sri-unix!quintus!ok
From: ok@quintus
Newsgroups: comp.arch
Subject: MC 88k question
Message-ID: <197@quintus.UUCP>
Date: 27 Jul 88 02:27:22 GMT
Sender: news@quintus.UUCP
Reply-To: ok@quintus ()
Organization: Quintus Computer Systems, Inc.
Lines: 13

The MC88000 has add and subtract instructions which
  - ignore overflow, another set which
  - set a carry bit, and another set which
  - trap on overflow.
But the multiply instruction apparently only comes in a
  - quietly truncate to 32 bits
flavour.  So what is the recommended way of doing a 32x32 integer
multiplication with an overflow check?

And could someone explain in simple terms what the "multiply step"
instruction present in several RISCs does and how I can use it to
get a 32x32 integer multiplication with an overflow check?

Thanks for your trouble.