[u-boot.git] / lib / rand.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Simple xorshift PRNG
 *   see http://www.jstatsoft.org/v08/i14/paper
 *
 * Copyright (c) 2012 Michael Walle
 * Michael Walle <[email protected]>
 */

#include <rand.h>

static unsigned int y = 1U;

unsigned int rand_r(unsigned int *seedp)
{
	*seedp ^= (*seedp << 13);
	*seedp ^= (*seedp >> 17);
	*seedp ^= (*seedp << 5);

	return *seedp;
}

unsigned int rand(void)
{
	return rand_r(&y);
}

void srand(unsigned int seed)
{
	y = seed;
}
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
9acf1ca5 MW	2	/*
	3	* Simple xorshift PRNG
	4	* see http://www.jstatsoft.org/v08/i14/paper
	5	*
	6	* Copyright (c) 2012 Michael Walle
	7	* Michael Walle <[email protected]>
9acf1ca5 MW	8	*/
9acf1ca5 MW	9
840ef4d4	10	#include <rand.h>
9acf1ca5 MW	11
	12	static unsigned int y = 1U;
	13
	14	unsigned int rand_r(unsigned int *seedp)
	15	{
	16	seedp ^= (seedp << 13);
	17	seedp ^= (seedp >> 17);
	18	seedp ^= (seedp << 5);
	19
	20	return *seedp;
	21	}
	22
	23	unsigned int rand(void)
	24	{
	25	return rand_r(&y);
	26	}
	27
	28	void srand(unsigned int seed)
	29	{
	30	y = seed;
	31	}