1 /* $NetBSD: fpu_getexp.c,v 1.5 2011/07/18 07:44:30 isaki 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 1.5 2011/07/18 07:44:30 isaki Exp $");
36
37 #include <sys/types.h>
38
39 #include "fpu_emulate.h"
40
41 struct fpn *
fpu_getexp(struct fpemu * fe)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 *
fpu_getman(struct fpemu * fe)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