| /* Copyright (C) 1995-2016 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 <ieee754.h> |
| #include <stdlib.h> |
| #include <limits.h> |
| |
| |
| int |
| __erand48_r (unsigned short int xsubi[3], struct drand48_data *buffer, |
| double *result) |
| { |
| union ieee754_double temp; |
| |
| /* Compute next state. */ |
| if (__drand48_iterate (xsubi, buffer) < 0) |
| return -1; |
| |
| /* Construct a positive double with the 48 random bits distributed over |
| its fractional part so the resulting FP number is [0.0,1.0). */ |
| |
| temp.ieee.negative = 0; |
| temp.ieee.exponent = IEEE754_DOUBLE_BIAS; |
| temp.ieee.mantissa0 = (xsubi[2] << 4) | (xsubi[1] >> 12); |
| temp.ieee.mantissa1 = ((xsubi[1] & 0xfff) << 20) | (xsubi[0] << 4); |
| |
| /* Please note the lower 4 bits of mantissa1 are always 0. */ |
| *result = temp.d - 1.0; |
| |
| return 0; |
| } |
| weak_alias (__erand48_r, erand48_r) |