Path: utzoo!utgpu!water!watmath!clyde!rutgers!sri-spam!ames!sdcsvax!ucsdhub!hp-sdd!hplabs!hpcea!hpfcdc!hpfclq!mike
From: mike@hpfclq.HP.COM (Mike McNelly)
Newsgroups: comp.sys.hp
Subject: Re: Sun as vs. HPUX as
Message-ID: <4260002@hpfclq.HP.COM>
Date: 18 Jan 88 16:43:29 GMT
References: <822@ucdavis.ucdavis.edu>
Organization: Hewlett-Packard
Lines: 17

> HP swapped the order of operands in compares:

	> cmpa.l	%a0,%a1  ==>	cmpa.l	%a1,%a0

When Motorola first introduced the 68020/68881 chips, the new addressing
modes required a change in assembly syntax because there were
ambiguities introduced.  Hence Motorola came out with two proposed
syntaxes, one for "general" use and another for "*nix" use.  We chose to
use the "*nix" version for HP-UX in order to be as compatable as
possible with the rest of the 68020 world.  Not all manufacturers made
the same decision.

The suggested Motorola syntax specified the swap of cmp instruction
operands.


Mike McNelly