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} 32