Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!HERMES.BERKELEY.EDU!dillon
From: dillon@HERMES.BERKELEY.EDU (Matt Dillon)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Official Warnings...
Message-ID: <8904250145.AA16021@hermes.berkeley.edu>
Date: 25 Apr 89 01:45:19 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 16

:	In the Jan/Feb 1989 issue of Amiga-Mail, under the "Official Warnings
:to ROM-Jumpers, Structure-Hackers, and Others", it states that you should
:NOT use the TAS assembly instruction.  What is the reason for this?
:
:	In my sine/cosine routines, I use the TAS instruction to set the sign
:flag if the result is negative.  Sure, I could change it to MOVEQ #-128,D1,
:but why is this instruction "bad"?
:
:--Brett S Bourbin

	People often miss the usefulness of the Scc instruction... set 
according to condition.  i.e.  seq, sne, ... a very useful instruction.  Using
Scc or any of the bit manipulation instructions bset, bclr, btst will probably
do what you want even better than tas, which should not be used on the amiga.

					-Matt