Hi.
Relevant excerpt of previous posts:
[...]
Something implicit in "BitStreamGenerator": the maximum number of
bits is 32 (cf. return type of "next(int)" and the ubiquitous use
of hard-coded "32".
What about the possibility of using a "long" as a building block
for another family of RNG?
Why? We don't have contributions of other RNGs implemented using
64-bit blocks of data. In theory, I guess you could do that, but I
don't know of any and all the ones we have use 32-bit words.
Phil
Gilles
(1)
CPUs and OS are nowadays commonly 64-bits based.
Thus one could legitimately wonder whether, on such systems, generating
one "long" value
would not be faster than generating
two "int" values,
especially when 64 bits are necessary in order to produce the next
random
"long" or "double" value.
(2)
There indeed exist 64-bits implementations of RNGs:
http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/VERSIONS/C-LANG/mt19937-64.c
http://burtleburtle.net/bob/rand/isaacafa.html
I thus propose to create a feature branch that will contain
* a new interface, for when "nextLong()" is the "random bits" producer
* the (adapted) "xorshift1024*" RNG implementation from
http://xorshift.di.unimi.it/
* an "adapter" to the existing generic methods
* benchmarking code
Gilles
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