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Article #12351Re: Official Warnings...
From: Matt Dillon
Date: Tue, 25 Apr 1989 01:45
Date: Tue, 25 Apr 1989 01:45
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: 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
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Path: arc1-ca.pugleaf.net!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