diff options
Diffstat (limited to 'REORG.TODO/stdlib/erand48_r.c')
-rw-r--r-- | REORG.TODO/stdlib/erand48_r.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/REORG.TODO/stdlib/erand48_r.c b/REORG.TODO/stdlib/erand48_r.c new file mode 100644 index 0000000000..8f6d3fad61 --- /dev/null +++ b/REORG.TODO/stdlib/erand48_r.c @@ -0,0 +1,47 @@ +/* Copyright (C) 1995-2017 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) |