RNGs: A Super KISS - sci.math

Message from discussion RNGs: A Super KISS

Tom St Denis

View profile

More options Nov 3 2009, 8:32 pm

Newsgroups: sci.math, comp.lang.c, sci.crypt

From: Tom St Denis <t...@iahu.ca>

Date: Tue, 3 Nov 2009 12:32:54 -0800 (PST)

Local: Tues, Nov 3 2009 8:32 pm

Subject: Re: RNGs: A Super KISS

  Forward
  | Print
  | View thread
  | Show original
  | Report this message
  | Find messages by this author
  

On Nov 3, 10:46 am, geo <gmarsag...@gmail.com> wrote:

> int refill( )
> { int i; unsigned long long t;
> for(i=0;i<41790;i++) { t=7010176LL*Q[i]+carry; carry=(t>>32); Q[i]=~
> (t);}
> indx=1; return (Q[0]);
> }

Not to nitpick but your C code could use some work. First off, some
indentation please? Second, returning a unsigned long long as "int"
is not very portable.

Part of the good thing of PRNGs is that they're reproduceable.
Ideally over different platforms. You should truncate the return
value if you want it as "int" or change the return type. As it stands
now this will produce different results on my x86-32 and 64 boxes for
the same seed, which is a bad thing.

Tom

Forward