Has anyone looked at the resultant distributions, to
determine how "random" they are?
--- Don Dailey <[EMAIL PROTECTED]> wrote:
> #include <stdio.h>
> #include <stdlib.h>
> I'm including my code below. Also, here are my
> reported times:
>
> Without RDTSC
>
> real 0m1.008s
> user 0m0.668s
> sys 0m0.004s
>
>
> With RDTSC
>
> real 0m5.790s
> user 0m3.956s
> sys 0m0.016s
>
>
> To turn on or off RDTSC see the rdtsc_rand line
> that says, "if (1)"
>
> - Don
>
> ----------[ snip ]------------
>
>
> #define rdtscll(val) \
> __asm__ __volatile__("rdtsc" : "=A" (val))
>
>
> unsigned long long rdtsc_rand(void);
>
>
/******************************************************/
> unsigned long long rdtsc_rand(void)
> {
> static unsigned long long
> val=0x0000000011111111ULL;
> unsigned long long new = 0llu;
>
> if (1) {
> rdtscll(new);
> }
>
> val ^= (val >> 15) ^ (val << 14) ^ 9 ^ new;
>
> return val;
> }
>
>
> void kessel()
> {
> int i;
> unsigned long long last = 0;
> unsigned long long cur = 0;
>
> for (i=100000000; i>0; i--) {
> cur = rdtsc_rand();
> if (i <= 10) {
> printf("%20llu %20lld\n", cur, (int) cur -
> last);
> }
> last = cur;
> }
> }
>
>
>
> int main(int argc, char **argv)
> {
>
> kessel();
>
> return(0);
> }
>
>
> A van Kessel wrote:
> >> I would like to mention that your generator is 64
> bit and the other
> >>
> > That is correct.
> >
> > My timings (Haven't profiled yet):
> > WITH TSC:
> > real 0m0.902s
> > user 0m0.870s
> > sys 0m0.002s
> >
> > WITHOUT:
> > real 0m0.613s
> > user 0m0.582s
> > sys 0m0.000s
> >
> > That's for 100 M random numbers.
> >
> > And inlining would probably help a lot, too.
> >
> > AvK
> > _______________________________________________
> > computer-go mailing list
> > computer-go@computer-go.org
> >
>
http://www.computer-go.org/mailman/listinfo/computer-go/
> >
> >
> _______________________________________________
> computer-go mailing list
> computer-go@computer-go.org
>
http://www.computer-go.org/mailman/listinfo/computer-go/
>
Terry McIntyre <[EMAIL PROTECTED]>
Wherever is found what is called a paternal government, there is found state
education. It has been discovered that the best way to insure implicit
obedience is to commence tyranny in the nursery.
Benjamin Disraeli, Speech in the House of Commons [June 15, 1874]
_______________________________________________
computer-go mailing list
computer-go@computer-go.org
http://www.computer-go.org/mailman/listinfo/computer-go/
