Re: A89: Re: how to test 2 keys at once? and another question.

To: assembly-89@lists.ticalc.org
Subject: Re: A89: Re: how to test 2 keys at once? and another question.
From: Johan <johei804@student.liu.se>
Date: Wed, 26 Apr 2000 23:17:18 +0200
In-Reply-To: <001201bfaf04$3e6faf60$da02e0c7@Pnoveck>; from Scott Noveck on Tue, Apr 25, 2000 at 18:18:53 -0400
References: <20000425201346.C98EEA4029@towerguard.edu.sollentuna.se> <001201bfaf04$3e6faf60$da02e0c7@Pnoveck>
Reply-To: assembly-89@lists.ticalc.org


On Tue, Apr 25, 2000 at 18:18:53 -0400, Scott Noveck wrote:
> 
> wow, I like that code so much I just had to write in and say so - I've
> always wondered what makes some of those opcodes useful, but how does this
> compare speed wise?

Assuming four clocks for memory reads:

	cmp	foo,bar
	seq	d0		; 6/4 (true/false)
	ext.w	d0		; 4
	sub.w	d0,d1		; 4
	; *** total = 14/12 clocks (added/did not)


	cmp	foo,bar
	bne.s	\dont_add_1	; 10/8 (jump/no jump)
	addq.w	#1,d1		; 4
\dont_add_1
	; *** total = 12/10 (added/did not)


/Johan

References:

From:

Re: A89: Re: how to test 2 keys at once? and another question.

From: "Scott Noveck" <noveck@pluto.njcc.com>

Prev: Re: A89: Re: Inline Assembly with GCC
Next: A89: 68K Assembly Tutorials
Index(es):
- Main
- Thread