/*      $NetBSD: fpu_getexp.c,v 1.5 2011/07/18 07:44:30 isaki Exp $     */

/*
* Copyright (c) 1995  Ken Nakata
*      All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*      @(#)fpu_getexp.c        10/8/95
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fpu_getexp.c,v 1.5 2011/07/18 07:44:30 isaki Exp $");

#include <sys/types.h>

#include "fpu_emulate.h"

struct fpn *
fpu_getexp(struct fpemu *fe)
{
       struct fpn *fp = &fe->fe_f2;

       fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */

       if (fp->fp_class == FPC_INF) {
               fp = fpu_newnan(fe);
               fe->fe_fpsr |= FPSR_OPERR;
       } else if (fp->fp_class == FPC_NUM) { /* a number */
               fpu_explode(fe, &fe->fe_f3, FTYPE_LNG, &fp->fp_exp);
               fp = &fe->fe_f3;
       } else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
               fe->fe_fpsr |= FPSR_SNAN;
       } /* else if fp == zero or fp == quiet NaN, return itself */
       return fp;
}

struct fpn *
fpu_getman(struct fpemu *fe)
{
       struct fpn *fp = &fe->fe_f2;

       fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */

       if (fp->fp_class == FPC_INF) {
               fp = fpu_newnan(fe);
               fe->fe_fpsr |= FPSR_OPERR;
       } else if (fp->fp_class == FPC_NUM) { /* a number */
               fp->fp_exp = 0;
       } else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
               fe->fe_fpsr |= FPSR_SNAN;
       } /* else if fp == zero or fp == quiet NaN, return itself */
       return fp;
}