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"Das U-Boot" Source Tree
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Simple xorshift PRNG
4 * see http://www.jstatsoft.org/v08/i14/paper
5 *
6 * Copyright (c) 2012 Michael Walle
7 * Michael Walle <michael@walle.cc>
8 */
9
10#include <rand.h>
11
12static unsigned int y = 1U;
13
14unsigned 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
23unsigned int rand(void)
24{
25 return rand_r(&y);
26}
27
28void srand(unsigned int seed)
29{
30 y = seed;
31}