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
