From:	robk AT cyberway DOT com DOT sg (Rob Kramer)
Newsgroups:	comp.os.msdos.djgpp
Subject:	386 SX versus DX - 'int' datatransfer
Date:	Fri, 16 Jul 1999 16:39:31 +0800
Message-ID:	<MPG.11f97084d7231b29989686@news.cyberway.com.sg>
Organization:	Infologic Pte Ltd
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

Hi all,

One of my applications (involving a GIF-decoder) I recently tried on a 
386 SX machine. The decoder is terribly slow in that case. The original 
pre-DJGPP obsolete 16-bit version of the application is way faster. (I'm 
not sure whether the 32-bit version is faster than the 16-bit version on 
a 386 DX)

The 16-bit version uses shorts as working variables in the decoder, the 
32-bit version uses ints. Could the big difference between running on a 
SX and a DX be caused by the fact that 32-bit transfers are not a nice 
thing on a SX databus?

Then would it help if I change back to shorts, or will this harm the 
performance of the decoder on 32 bits databus machines. Note that the 
decoder doesn't actually need ints, but I thought ints were friendlier to 
a Pentium architecture. That's what it normally runs on, but I have to 
support 386SX too :( 

Cheers!

	Rob Kramer
	Singapore

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