xref: /netbsd-src/sys/arch/m68k/fpe/fpu_getexp.c (revision 86811edb37e43f44504b192591c863c5d48f5e08)
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(fe)
43      struct fpemu *fe;
44 {
45   struct fpn *fp = &fe->fe_f2;
46 
47   fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */
48 
49   if (fp->fp_class == FPC_INF) {
50     fp = fpu_newnan(fe);
51     fe->fe_fpsr |= FPSR_OPERR;
52   } else if (fp->fp_class == FPC_NUM) { /* a number */
53     fpu_explode(fe, &fe->fe_f3, FTYPE_LNG, &fp->fp_exp);
54     fp = &fe->fe_f3;
55   } else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
56     fe->fe_fpsr |= FPSR_SNAN;
57   } /* else if fp == zero or fp == quiet NaN, return itself */
58   return fp;
59 }
60 
61 struct fpn *
62 fpu_getman(fe)
63      struct fpemu *fe;
64 {
65   struct fpn *fp = &fe->fe_f2;
66 
67   fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */
68 
69   if (fp->fp_class == FPC_INF) {
70     fp = fpu_newnan(fe);
71     fe->fe_fpsr |= FPSR_OPERR;
72   } else if (fp->fp_class == FPC_NUM) { /* a number */
73     fp->fp_exp = 0;
74   } else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
75     fe->fe_fpsr |= FPSR_SNAN;
76   } /* else if fp == zero or fp == quiet NaN, return itself */
77   return fp;
78 }
79 
80