Take 2: new IP Checksum Code from DragonFlyBSD

[Gordon Bergling]

Hi,

a few month ago I ported DragonFlyBSD's IP checksum code to FreeBSD.
My first try wasn't complete and I had forgotten it by the time. Now I
hope I have addressed the former mistakes and it maybe included in the
tree. ;)

The patch can be found at
http://generic.0xfce3.net/20060524-ipchecksum.patch

This patch modifies the i386, amd64 and pc98 architectures. Matt Dillons
new implementation is machine indepement, but there are some asm
files/code with seems for me i386 centric. I don't know assembler, so I
can't tell much about it.

I applied the patch to RELENG_6 and have done a simple netperf
benchmark. The machine was a PIII 900.

The ministat output:
----------------------------------------------------------------------------
x netperf-localhost-plain.txt
+ netperf-localhost-ncksum.txt
+--------------------------------------------------------------------------+
|      x     x     x      x        +             ++               +        |
|xx    x     x  xx xxx    x  x x  x+x   *+x x +  +++   ++  +  + + +++++   +|
|        |__________M_A____________|        |__________A___________|       |
+--------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x  22        707.31        730.41        717.37     718.53909     6.7389076
+  22        725.57        746.46       736.535     736.51727     6.3001188
Difference at 95.0% confidence
	17.9782 +/- 3.96904
	2.50205% +/- 0.552377%
	(Student's t, pooled s = 6.5232)
----------------------------------------------------------------------------

Any comments, correctures are very appreciated.

best regards,

	Gordon

-- 
Gordon Bergling <GBergling at 0xfce3.net>	      http://www.0xFCE3.net/
PGP Fingerprint:  7732 9BB1 5013 AE8B E42C  28E0 93B9 D32B C76F 02A0
RIPE-HDL: MDTP-RIPE				  "Minimal Electronic Music"