A Tausworthe random number generator

[John Colvin]

On Tuesday, 21 January 2014 at 10:05:42 UTC, terchestor wrote:
> I'm a newcomer to D language (after years of programming with 
> ASM Motorola 68030-40 long time ago, as well as C, C++, 
> Javascript, PHP, etc.), but not anymore a professional coder.
> After reading some articles around there and that nice and cute 
> TDPL (just after Coding standards, another world!), I began to 
> write some to exercise my fresh new "skill".
> I choose as a first experience, to write a simple class 
> implementing a very interesting random number generator known 
> as Tausworthe, according to the recipe found in this paper: 
> http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.101.9723&rep=rep1&type=pdf.
> The algorithm in C is quite simple and set in Lecuyer's paper 
> as:
>
> unsigned long s1, s2, s3, b;
> double taus88 ()
> {
>  /* Generates numbers between 0 and 1. */
> b = (((s1 << 13) ^ s1) >> 19);
> s1 = (((s1 & 4294967294) << 12) ^ b);
> b = (((s2 << 2) ^ s2) >> 25);
> s2 = (((s2 & 4294967288) << 4) ^ b);
> b = (((s3 << 3) ^ s3) >> 11);
> s3 = (((s3 & 4294967280) << 17) ^ b);
> return ((s1 ^ s2 ^ s3) * 2.3283064365e-10);
> }
>
> I made some "adjustments" to this algorithm, to yield either a 
> (long) integer or (double) float result, in any range.
>
> Benchmarks
> ----------
> Tausworthe module (rdmd -main -unittest 
> -debug=Benchmark_Tausworthe tausworthe.d)
> ============================================================
> Call 1_000_000 times benchmark_uniform_ulong( ): 30 ms | 
> Average : 3e-05 ms
> ============================================================
> ============================================================
> Call 1_000_000 times benchmark_uniform_double( ): 42 ms | 
> Average : 4.2e-05 ms
> ============================================================
> ============================================================
> Call 1_000_000 times benchmark_uniform_std( ): 70 ms | Average 
> : 7e-05 ms
> ============================================================
> Comparing ratio tausworthe / std.random:  0.609229
>
> I'd greatly appreciate any reviewing and testing of my code. 
> Any improvements you feel necessary are most welcome (as said 
> before, I'm a newbie).
>
> What's the best place to publish the code?

Github, bitbucket or equivalent.

If you think it's ready for general use then write a dub.json and 
register it to code.dlang.org


Take care with modifying random number generators, it's quite 
easy to ruin them by changing something that seems innocent.