John, if you're using a little endian processor, I've posted a patch (in the patch section) that made some improvement for me.
Bill >-----Original Message----- >From: [email protected] >[mailto:[email protected]] On >Behalf Of John Kennedy >Sent: Thursday, May 28, 2009 9:17 AM >To: Mailing list for lwIP users >Subject: RE: RE: [lwip-users] Sizes > >Well, just for fun I switched to algorithm 3 and got a 100Kbits/s >improvement. > >John > > > >________________________________________ >John Kennedy > > >Idaho Technology Inc. >390 Wakara Way >Salt Lake City, UT 84108, USA > >USA: 1-800-735-6544 >Bus:+1 (801)736-6354 x448 >Fax:+1 (801)588-0507 > >http://www.idahotech.com/ >-----Original Message----- >From: Simon Goldschmidt [mailto:[email protected]] >Sent: Thursday, May 28, 2009 1:16 AM >To: Mailing list for lwIP users >Subject: Re: RE: [lwip-users] Sizes > > >> BTW which checksum algorithm did base your >> assembly code on? Does anyone know which of the checksum algorithms >is the >> fastest? > >Unfortunately, that depends largely on your platform. The best thing to >do is to try all of them: call them in a loop on a data buffer that is >bigger than your caches and see which one finishes first. > >> I'm a little surprised that other than the call overhead that an >> assembly version of memcpy is much faster than what the complier >produces from the library? > >The difference here is not C or assembly but 'standard' library (written >in C, used on many platforms) or hand-written code that performs well on >your specific platform. And let me tell you there *is* room for >improvement here. For example, some C libraries use byte-by-byte copy if >compiled with the 'wrong' options... Nevertheless, the standard library >often is not too bad when copying a well-aligned source to a well- >aligned destination. > >Simon >-- >Neu: GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate + >Telefonanschluss für nur 17,95 Euro/mtl.!* >http://portal.gmx.net/de/go/dsl02 > > >_______________________________________________ >lwip-users mailing list >[email protected] >http://lists.nongnu.org/mailman/listinfo/lwip-users > >________________________________________ >CONFIDENTIALITY NOTICE: This E-mail and any attachments are confidential >information of the sender and are for the exclusive use of the intended >recipient. If you are not the intended recipient, be aware that any >disclosure, copying, distribution, or use of this E-mail or any >attachment is prohibited. If you have received this E-mail in error, >please notify us immediately by returning it to the sender and delete >this copy from your system. Thank you for your cooperation. > > > > >_______________________________________________ >lwip-users mailing list >[email protected] >http://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
