Subversion Repositories openrisc_2011-10-31

/* @(#)z_frexpf.c 1.0 98/08/13 */

/******************************************************************

 * frexp

 *

 * Input:

 *   d   - floating point value

 *   exp - exponent value

 *

 * Output:

 *   A floating point value in the range [0.5, 1).

 *

 * Description:

 *   This routine breaks a floating point value into a number f and

 *   an exponent exp such that d = f * 2 ^ exp.

 *

 *****************************************************************/

#include "fdlibm.h"

#include "zmath.h"

float frexpf (float d, int *exp)

{

  float f;

  __int32_t wf, wd;

  /* Check for special values. */

  switch (numtestf (d))

    {

      case NAN:

      case INF:

        errno = EDOM;

      case 0:

        *exp = 0;

        return (d);

    }

  GET_FLOAT_WORD (wd, d);

  /* Get the exponent. */

  *exp = ((wd & 0x7f800000) >> 23) - 126;

  /* Get the mantissa. */

  wf = wd & 0x7fffff;

  wf |= 0x3f000000;

  SET_FLOAT_WORD (f, wf);

  return (f);

}

#ifdef _DOUBLE_IS_32BITS

double frexp (double x, int *exp)

{

  return (double) frexpf ((float) x, exp);

}

#endif /* defined(_DOUBLE_IS_32BITS) */