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- /* Reentrant random function frm POSIX.1c.
- Copyright (C) 1996, 1999 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@cygnus.com <mailto:drepper@cygnus.com>>, 1996.
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
- The GNU C Library 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
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
- #include <stdlib.h>
- /* This algorithm is mentioned in the ISO C standard, here extended
- for 32 bits. */
- int rand_r (unsigned int *seed)
- {
- unsigned int next = *seed;
- int result;
- next *= 1103515245;
- next += 12345;
- result = (unsigned int) (next / 65536) % 2048;
- next *= 1103515245;
- next += 12345;
- result <<= 10;
- result ^= (unsigned int) (next / 65536) % 1024;
- next *= 1103515245;
- next += 12345;
- result <<= 10;
- result ^= (unsigned int) (next / 65536) % 1024;
- *seed = next;
- return result;
- }
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