frexp.c

一个C源代码分析器

/* Copyright (C) 1993 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 <math.h>
#include "ieee754.h"

/* Break VALUE into a normalized fraction and an integral power of 2.  */

double
frexp (value, exp)
     double value;
     int *exp;
{
  if (value == 0)
    {
      *exp = 0;
      return 0;
    }
  else
    {
      union ieee754_double u;
      u.d = value;
      *exp = u.ieee.exponent - 1022;
      u.ieee.exponent = 1022;
      return u.d;
    }
}