Path: utzoo!attcan!uunet!cs.utexas.edu!rutgers!apple!farrier
From: farrier@Apple.COM (Cary Farrier)
Newsgroups: comp.sys.apple
Subject: Re: JMP/JML revisited...
Message-ID: <30445@apple.Apple.COM>
Date: 10 May 89 19:38:53 GMT
References: <8905101021.aa15777@SMOKE.BRL.MIL>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 25

In article <8905101021.aa15777@SMOKE.BRL.MIL> JWANKERL@UTCVM.BITNET ("Josef W. Wankerl") writes:
>BIG OOOOOOOPS!!!
>
>I didn't mean JML... I meant BRL.  (They both have L so I guess that's
>what messed me up.  I have it straight when I program...  :-)
>
>
>They're both 3 byte instructions, but is there any difference in
>execution time?  On range?
>
	The advantage of a JMP is that you can use absolute [ JMP addr ], 
	absolute indirect [ JMP (addr) ], and absolute indexed 
	indirect [ JMP(addr,x) ].  A BRL can only use absolute [ BRL addr ].
	The BRL is, however, relocatable.  This is good in case you wish to
	move a segment of code from one memory location to another.

	About exection times and instruction sizes:
		BRL addr	4 cycles 	3 bytes
		JMP addr	3 cycles	3 bytes
		JMP (addr)	5 cycles	3 bytes
		JMP (addr,x)	6 cycles	3 bytes

	Both have the same range.

Cary Farrier