sys/arch/m68k/fpe/fpu_getexp.c

   1 /*      $NetBSD: fpu_getexp.c,v 1.3 2005/12/11 12:17:52 christos Exp $  */
   2
   3 /*
   4  * Copyright (c) 1995  Ken Nakata
   5  *      All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the author nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)fpu_getexp.c        10/8/95
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __KERNEL_RCSID(0, "$NetBSD: fpu_getexp.c,v 1.3 2005/12/11 12:17:52 christos Exp $");
  36
  37 #include <sys/types.h>
  38
  39 #include "fpu_emulate.h"
  40
  41 struct fpn *
  42 fpu_getexp(struct fpemu *fe)
  43 {
  44   struct fpn *fp = &fe->fe_f2;
  45
  46   fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */
  47
  48   if (fp->fp_class == FPC_INF) {
  49     fp = fpu_newnan(fe);
  50     fe->fe_fpsr |= FPSR_OPERR;
  51   } else if (fp->fp_class == FPC_NUM) { /* a number */
  52     fpu_explode(fe, &fe->fe_f3, FTYPE_LNG, &fp->fp_exp);
  53     fp = &fe->fe_f3;
  54   } else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
  55     fe->fe_fpsr |= FPSR_SNAN;
  56   } /* else if fp == zero or fp == quiet NaN, return itself */
  57   return fp;
  58 }
  59
  60 struct fpn *
  61 fpu_getman(struct fpemu *fe)
  62 {
  63   struct fpn *fp = &fe->fe_f2;
  64
  65   fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */
  66
  67   if (fp->fp_class == FPC_INF) {
  68     fp = fpu_newnan(fe);
  69     fe->fe_fpsr |= FPSR_OPERR;
  70   } else if (fp->fp_class == FPC_NUM) { /* a number */
  71     fp->fp_exp = 0;
  72   } else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
  73     fe->fe_fpsr |= FPSR_SNAN;
  74   } /* else if fp == zero or fp == quiet NaN, return itself */
  75   return fp;
  76 }
  77