mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-28 23:34:53 +03:00
50 lines
1.6 KiB
C
50 lines
1.6 KiB
C
/* Copyright (C) 1995-2014 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 (xsubi, buffer, result)
|
|
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)
|