Message-ID: <378F6F22.36FA@ns.sympatico.ca> From: Klaas Organization: N/A X-Mailer: Mozilla 3.04 (Win95; I) MIME-Version: 1.0 Newsgroups: comp.os.msdos.djgpp Subject: Re: 386 SX versus DX - 'int' datatransfer References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 25 Date: Fri, 16 Jul 1999 14:42:58 -0300 NNTP-Posting-Host: 142.177.41.102 X-Trace: sapphire.mtt.net 932147335 142.177.41.102 (Fri, 16 Jul 1999 14:48:55 ADT) NNTP-Posting-Date: Fri, 16 Jul 1999 14:48:55 ADT To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Rob Kramer wrote: > > 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 :( Do you use any floating point math? The SX would have to emulate, which wuold be considerably slower. -Mike