Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!tut.cis.ohio-state.edu!kingkong.cis.ohio-state.edu!meekins
From: meekins@kingkong.cis.ohio-state.edu (Tim Meekins)
Newsgroups: comp.sys.apple2
Subject: Re: help optimizing asm routine (and help with GetCaretTime)
Message-ID: <125198@tut.cis.ohio-state.edu>
Date: 24 May 91 14:33:54 GMT
Sender: news@tut.cis.ohio-state.edu
Organization: The Ohio State University, Department of Computer and Information Science
Lines: 36

In article <1991May24.111453.27330@nntp-server.caltech.edu> toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes:

>>:6             ldy     ]x
>>:4             lda     []off_image],y
>>               sta     []image],y
>>               dey
>>               dey
>>               bpl     :4
>
>Jeezus. LHG at its slowest uses a loop like this. You can use MVP/MVN a lot
>of the time (yes, you really can use them -- get sneaky), and most of the
>time (except under Orca) you can map the stack into the shadowed graphics
>page and romp pixels to the screen.

A lot also depends on where off_image and image point to. If you know they're
in the same bank you can greatly speed this up. Also self-modifying code is
handy in these situations. For minor speed improvement, try unrolling by
a factor of 1. This will cut the bpl count in half. But then you need to know
you're copying a min up 4 bytes instead of 2...

>
>Sure it sounds sick but that's tough noogies. Think about it for a while and
>then mail me. Don't listen to Tim Meekins, or your code won't work with
>AppleTalk (in fact he's lucky it works at all -- do you EVER check to see
>where the standard GrafPort is, Tim?).
>


Come on Todd, that was only in ONE program a LONG time ago.. I challenge you
to crash ZLaunch.... (Hmmm. well I'm assuming my newer demos work....)

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