From: Robin Burrows <rburrows AT hotmail DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Code speed-up
Date: Wed, 28 Jan 1998 16:40:50 +0000
Organization: Virgin Net Usenet Service	
Lines: 16
Message-ID: <34CF5F92.126C@hotmail.com>
Reply-To: rburrows AT hotmail DOT com
NNTP-Posting-Host: 194.168.73.210
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk

Hello,
  Anyone suggest a speed up for this little bit of code:

	for (l=0;l<mapblockheight;l++) {
		maplinecpypt = (unsigned char *) mapdestpt->line[(l+j)] + i;
		for (k=0;k<mapblockwidth;k++) {
			*maplinecpypt = *mapgfxpt; maplinecpypt++; mapgfxpt++;
		}
	}

It seems quite inefficient copying a byte over a 32bit bus, but I'm not
sure how odd addresses would affect a bigger move. The inner line of
this function is called 256*180 times for ONE screen update.

Regards,
Robin Burrows.