/*  Written in 2016-2018 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.

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <stdint.h>

/* The current state of the generator. */
static uint64_t s[2] = { 1, 1 };

static inline uint64_t rotl(const uint64_t x, int k) {
	return (x << k) | (x >> (64 - k));
}

static uint64_t inline next(void) {
	const uint64_t s0 = s[0];
	uint64_t s1 = s[1];

	const uint64_t result_plus = s0 + s1;

	s1 ^= s0;
	s[0] = rotl(s0, 24) ^ s1 ^ (s1 << 16);
	s[1] = rotl(s1, 37);

	return result_plus;
}

#include "harness.c"