[ECOS] TCP/IP performance under eCos & other compilers than gnu

[Grant Edwards]

On Mon, Oct 01, 2001 at 09:39:20AM +0200, Andrew Lunn wrote:

> Quite a while back there was a post to the list about gcc producing
> slow CRC calculation code when using -O3. I don't remember all the
> details, so find the post in the archive. I think if you compiled the
> CRC code -O you got faster code.

[I assume you're talking about the IP checksum routine, since I
don't remember any CRC stuff in the TCP/IP network stack.] With
-O3 optimization arm-gcc 2.95.2 starts "register thrashing" and
generates code that's about 50% slower than -O0.  I switched to
an assembly language checksum, which improved throughput
considerably on myplatform.  I've attached the changed files in
case you want to try it.

-- 
Grant Edwards
grante@visi.com