lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1995, 1996, 2001 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, write to the Free |
| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 18 | 02111-1307 USA. */ |
| 19 | |
| 20 | #include <errno.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <limits.h> |
| 23 | #include <stdint.h> |
| 24 | #include <stdlib.h> |
| 25 | #include <sys/types.h> |
| 26 | |
| 27 | /* Global state for non-reentrant functions. */ |
| 28 | struct drand48_data __libc_drand48_data; |
| 29 | |
| 30 | #ifdef __UCLIBC_MJN3_ONLY__ |
| 31 | #warning turn int __drand48_iterate into void |
| 32 | #endif /* __UCLIBC_MJN3_ONLY__ */ |
| 33 | int __drand48_iterate (unsigned short int xsubi[3], struct drand48_data *buffer) |
| 34 | { |
| 35 | uint64_t X; |
| 36 | uint64_t result; |
| 37 | |
| 38 | /* Initialize buffer, if not yet done. */ |
| 39 | if (unlikely(!buffer->__init)) |
| 40 | { |
| 41 | buffer->__a = 0x5deece66dull; |
| 42 | buffer->__c = 0xb; |
| 43 | buffer->__init = 1; |
| 44 | } |
| 45 | |
| 46 | /* Do the real work. We choose a data type which contains at least |
| 47 | 48 bits. Because we compute the modulus it does not care how |
| 48 | many bits really are computed. */ |
| 49 | |
| 50 | X = (uint64_t) xsubi[2] << 32 | (uint32_t) xsubi[1] << 16 | xsubi[0]; |
| 51 | |
| 52 | result = X * buffer->__a + buffer->__c; |
| 53 | |
| 54 | xsubi[0] = result & 0xffff; |
| 55 | xsubi[1] = (result >> 16) & 0xffff; |
| 56 | xsubi[2] = (result >> 32) & 0xffff; |
| 57 | |
| 58 | return 0; |
| 59 | } |