> From: Patrick Schaaf <[EMAIL PROTECTED]>
> static u32 hash_abcd_host(struct ct_key *key)
> {
> u32 res;
> PER_HASH_TIMER_1(
> res = 0x47441DFB * ntohl(key->sip)
> + 0x57655A7D * ntohl(key->dip)
> + 0x1C7F1D2D * ntohs(key->sport)
> + 0xDF91D738 * ntohs(key->dport)
> + key->proto;
> );
> return res;
> }
>
> Slightly surprising, this code runs about half as fast as the normal abcd,
> on my little endian box.
I guess that shows that the ntohl/s's take about as much time as the rest.
> Now there is http://bei.bof.de/cttest-0.5.tar.gz and an example
> presentation at http://bei.bof.de/ex4/
(Is this getting out of hand?)
> BTW, it should be possible to gather reports generated by different
> people
...
I suggest that you collect up their original data sets so other people
can experiment with those.
And finally, here's the current version of A-F which I am determined
to make my LAST version. This is the result of a little more
communication with my friendly crypto expert.
/* for 32866 entries table size: length of longest bucket
256:158 512:89 1K:49 2K:30 4K:21 8K:13 16K:10 32K:8 64K:6 256K:4 */
unsigned long long ls, ld, lp;
long sum;
ls = (unsigned long long) key->sip * A;
ld = (unsigned long long) key->dip * B;
lp = (unsigned long long) C * (u32)((u32)(key->sport << 16) + key->dport);
sum =
(ls ^ (ls >> 32) +
ld ^ (ld >> 32) +
lp ^ (lp >> 32) +
E * key->proto) ^ F;
return sum;
> As nobody requested the tarball yet, I've remade it with the latest
> 64 bit ABCDEF code from Don. I also remade the ex4/ pictures,
> in the abcd series, Don's new hash is named abcd_long. Looks good,
> takes about 2.2 times as long as abcd.
(Darn. So 64 bit does take a lot longer.)
> I call it a night now. Take care.
Me too.
