Date: Fri, 13 Jan 95 16:49 MST
From: mat AT ardi DOT com (Mat Hostetter)
To: THE MASKED PROGRAMMER <badcoe AT bsa DOT bris DOT ac DOT uk>
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Optimizing the conversion loop
References: <0098A693 DOT C4DAB1BD DOT 23 AT bsa DOT bristol DOT ac DOT uk>

When asking for help with an algorithm, it is helpful if you can
formulate the problem in simple terms.  From looking at your code, it
looks like your problem is "I want to map an array of 16 bit values to
an array of 8 bit values via a 64K lookup table as quickly as
possible".  Is this a fair assessment?  This is a much different
statement than your original question, which unnecessarily brought up
two dimensional arrays.

I have a question for you: does %es refer to conventional memory (so
you can access the VGA frame buffer), or is all of this taking place
in PM memory?

I noticed a few efficiency problems with your code, although to be
honest I don't know much about optimizing for the 80386 in particular.
Do you want this to be fast on all x86's or do you only care about the
80386?

-Mat