From: Kbwms AT aol DOT com
Message-ID: <26812372.3651be7b@aol.com>
Date: Tue, 17 Nov 1998 13:20:43 EST
To: DJ Delorie <dj AT delorie DOT com>
Cc: djgpp-workers AT delorie DOT com
Mime-Version: 1.0
Subject: Re: src/libc/ansi/stdlib/rand.c
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Reply-To: djgpp-workers AT delorie DOT com

Dear DJ Delorie,

On 11-17-98 at 11:14:38 EST you wrote:
>
> > However, there is another problem with a 64-bit generator and a
> > 32-bit seed, in that it will not be possible to re-start the
> > generator at some state that it has gotten itself into.
>
> This is impossible anyway, since there's no way to get the current
> seed.
>
> > My vote would be for a simple 32-bit generator.
>
> 64-bit generators are "more random" (we hope).
>

The only advantage one gets from a 64-bit generator, assuming that it is
a full-period generator, is a longer period.  This generator is full period
with a period of 2^64.  

Technology is beginning to make a simple 32-bit generator more like a
toy generator.  The period of a full-period 32-bit generator is only
2^32.  With the advent of even-faster computers, it will be duck soup
to consume the full cycle of random numbers from a 32-bit generator. 


K.B. Williams