/* * Simple xorshift PRNG * see http://www.jstatsoft.org/v08/i14/paper * * Copyright (c) 2012 Michael Walle * Michael Walle <michael@walle.cc> * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ #include <common.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; }