mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-27 05:00:15 +00:00
54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
|
|
Cambridge, MA 02139, USA. */
|
|
|
|
#include <ansidecl.h>
|
|
#include <errno.h>
|
|
#include <math.h>
|
|
|
|
/* Break VALUE into a normalized fraction and an integral power of 2. */
|
|
double
|
|
DEFUN(frexp, (value, exp), double value AND int *exp)
|
|
{
|
|
#ifdef NAN
|
|
if (__isinf (value))
|
|
{
|
|
errno = EDOM;
|
|
*exp = 0;
|
|
return __copysign (NAN, value);
|
|
}
|
|
#endif
|
|
|
|
if (__isnan (value))
|
|
{
|
|
errno = EDOM;
|
|
*exp = 0;
|
|
return value;
|
|
}
|
|
|
|
if (value == 0)
|
|
{
|
|
*exp = 0;
|
|
return value;
|
|
}
|
|
|
|
/* Add one to the exponent of the number,
|
|
so we have one digit before the binary point. */
|
|
*exp = (int) __logb (value) + 1;
|
|
return ldexp (value, - *exp);
|
|
}
|