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- /* Copyright (C) 1995, 1996, 2001 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
- 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 <errno.h>
- #include <stdlib.h>
- #include <limits.h>
- #include <stdint.h>
- #include <stdlib.h>
- #include <sys/types.h>
- /* Global state for non-reentrant functions. */
- struct drand48_data __libc_drand48_data;
- #ifdef __UCLIBC_MJN3_ONLY__
- #warning turn int __drand48_iterate into void
- #endif /* __UCLIBC_MJN3_ONLY__ */
- int __drand48_iterate (unsigned short int xsubi[3], struct drand48_data *buffer)
- {
- uint64_t X;
- uint64_t result;
- /* Initialize buffer, if not yet done. */
- if (unlikely(!buffer->__init))
- {
- buffer->__a = 0x5deece66dull;
- buffer->__c = 0xb;
- buffer->__init = 1;
- }
- /* Do the real work. We choose a data type which contains at least
- 48 bits. Because we compute the modulus it does not care how
- many bits really are computed. */
- X = (uint64_t) xsubi[2] << 32 | (uint32_t) xsubi[1] << 16 | xsubi[0];
- result = X * buffer->__a + buffer->__c;
- xsubi[0] = result & 0xffff;
- xsubi[1] = (result >> 16) & 0xffff;
- xsubi[2] = (result >> 32) & 0xffff;
- return 0;
- }
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