43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/* Written in 2019 by David Blackman and Sebastiano Vigna (vigna@acm.org)
|
|
|
|
To the extent possible under law, the author has dedicated all copyright
|
|
and related and neighboring rights to this software to the public domain
|
|
worldwide. This software is distributed without any warranty.
|
|
|
|
See <http://creativecommons.org/publicdomain/zero/1.0/>. */
|
|
|
|
#include "xoshiro128.h"
|
|
|
|
/* This is xoshiro128++ 1.0, one of our 32-bit all-purpose, rock-solid
|
|
generators. It has excellent speed, a state size (128 bits) that is
|
|
large enough for mild parallelism, and it passes all tests we are aware
|
|
of.
|
|
|
|
For generating just single-precision (i.e., 32-bit) floating-point
|
|
numbers, xoshiro128+ is even faster.
|
|
|
|
The state must be seeded so that it is not everywhere zero. */
|
|
|
|
|
|
static inline uint32 rotl(const uint32 x, int k) {
|
|
return (x << k) | (x >> (32 - k));
|
|
}
|
|
|
|
uint32 xoshiro128plusplus_next(void* _state){
|
|
xoshiro128_state* state=_state;
|
|
const uint32 result = rotl(state->s[0] + state->s[3], 7) + state->s[0];
|
|
|
|
const uint32 t = state->s[1] << 9;
|
|
|
|
state->s[2] ^= state->s[0];
|
|
state->s[3] ^= state->s[1];
|
|
state->s[1] ^= state->s[2];
|
|
state->s[0] ^= state->s[3];
|
|
|
|
state->s[2] ^= t;
|
|
|
|
state->s[3] = rotl(state->s[3], 11);
|
|
|
|
return result;
|
|
}
|