Re: KISS4691, a potentially top-ranked RNG.

[David Bernier <david250@videotron.ca>]

Ian Collins wrote:
> On 04/29/11 01:50 PM, David Bernier wrote:
[...]

>> All we have now are George Marsaglia's posts and writings.
>> I know there's now a move on the way to 64-bit processors,
>> which I take to mean the x86_64 or AMD64 design/instruction set.
>
> The move happened several years ago (at least on the desktop and server).
>
>> In any case, with an executable compiled with a C compiler,
>> there's the function sizeof, which might be useful
>> in some cases at run time.
>
> Being pedantic, sizeof is a compile time operator when used with
> integral types.
>
>> For example, one could add to main() in C :
>>
>> printf("the size of an unsigned long in bytes is %d\n",
>> sizeof(unsigned long));
>
> Given the code as written, assert(sizeof(unsigned long) == 4) would be
> more use.
>
>> There's also the Itanium architecture and others, and even with a known
>> processor, some compiler flags affect the number of bytes for
>> some data types, such as "long double" with the -m64 flag
>> on Fujitsu SPARC IV with Sun Solaris (--> 16 byte long
>> doubles with the -m64 flag).
>>
>> AFAIK, sizeof(unsigned long) can be relied upon to give the size
>> in 8-bit bytes of a C "unsigned long".
>
> sizeof(unsigned long) is by definition the size in (not necessarily 8
> bit) bytes of an unsigned long.
>
>> Perhaps some documentation of language, machine, compiler, compiler
>> options examples where KISS4691 works as per the Marsaglia
>> specs could be helpful as a reference ...
>
> I suggested long ago the code be updated to use fixed width types, thus
> removing any ambiguities.

I'm sorry about the inaccuracies and falsehoods in my post.
I support your suggestion, perhaps also adding comments.
I'm the wrong person to update the code, but I would be
willing to test updated C code.

David Bernier