1/*	$NetBSD: fpu_getexp.c,v 1.4 2009/03/14 15:36:09 dsl 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 1.4 2009/03/14 15:36:09 dsl Exp $");
36
37#include <sys/types.h>
38
39#include "fpu_emulate.h"
40
41struct fpn *
42fpu_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
60struct fpn *
61fpu_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