Hi:
> On 03 Apr 2015, at 17:44, Eliot Miranda <[email protected]> wrote:
>
> seed := ((seed + 16r7ed55d16) + (seed << 12)) & 16rffffffff.
> seed := ((seed ^ 16rc761c23c) ^ (seed as32BitSignedValue >>> 19)) &
> 16rffffffff.
> seed := ((seed + 16r165667b1) + (seed << 5)) & 16rffffffff.
> seed := ((seed + 16rd3a2646c) ^ (seed << 9)) & 16rffffffff.
> seed := ((seed + 16rfd7046c5) + (seed << 3)) & 16rffffffff.
> seed := ((seed ^ 16rb55a4f09) ^ (seed as32BitSignedValue >>> 16)) &
> 16rffffffff.
> ^ seed as32BitSignedValue
Ok, my implementation looks now like this:
random
"Robert Jenkins' 32 bit integer hash function."
seed := ((seed + 16r7ed55d16) + (seed << 12)).
seed := ((seed bitXor: 16rc761c23c) bitXor: ((seed bitAnd: 16rffffffff) >>
19)).
seed := ((seed + 16r165667B1) + (seed << 5)).
seed := ((seed + 16rd3a2646c) bitXor: (seed << 9)).
seed := ((seed + 16rfd7046c5) + (seed << 3)).
seed := self as32BitSigned: ((seed bitXor: 16rb55a4f09) bitXor: ((seed
bitAnd: 16rffffffff) >> 16)).
^ seed
as32BitSigned: val
| r |
r := val bitAnd: 16rffffffff.
(r bitAnd: 16r80000000) = 0 ifTrue: [ ^ r ].
^ (16r100000000 - r) * -1
The #as32BitSigned: looks a little naive, but didn’t have any better idea.
And Andres, the random number generator is a given, I can’t just change it.
Best regards
Stefan
--
Stefan Marr
INRIA Lille - Nord Europe
http://stefan-marr.de/research/
