1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1988 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30
31#pragma ident	"%Z%%M%	%I%	%E% SMI"
32
33/*
34 * Macros to pull apart parts of single and  double precision
35 * floating point numbers in IEEE format
36 * Be sure to include /usr/include/values.h before including
37 * this file to get the required definition of _IEEE
38 */
39
40#if _IEEE
41#if defined(__sparc)
42/* byte order with high order bits at lowest address */
43
44/* double precision */
45typedef  union {
46	struct {
47		unsigned  sign	:1;
48		unsigned  exp	:11;
49		unsigned  hi	:20;
50		unsigned  lo	:32;
51	} fparts;
52	struct {
53		unsigned  sign	:1;
54		unsigned  exp	:11;
55		unsigned  qnan_bit	:1;
56		unsigned  hi	:19;
57		unsigned  lo	:32;
58	} nparts;
59	struct {
60		unsigned hi;
61		unsigned lo;
62	} fwords;
63	double	d;
64} _dval;
65
66/* single precision */
67typedef  union {
68	struct {
69		unsigned sign	:1;
70		unsigned exp	:8;
71		unsigned fract	:23;
72	} fparts;
73	struct {
74		unsigned sign	:1;
75		unsigned exp	:8;
76		unsigned qnan_bit	:1;
77		unsigned fract	:22;
78	} nparts;
79	unsigned long	fword;
80	float	f;
81} _fval;
82
83
84#elif defined(__i386) || defined(__amd64)
85/* byte order with low order bits at lowest address */
86
87/* double precision */
88typedef  union {
89	struct {
90		unsigned  lo	:32;
91		unsigned  hi	:20;
92		unsigned  exp	:11;
93		unsigned  sign	:1;
94	} fparts;
95	struct {
96		unsigned  lo	:32;
97		unsigned  hi	:19;
98		unsigned  qnan_bit	:1;
99		unsigned  exp	:11;
100		unsigned  sign	:1;
101	} nparts;
102	struct {
103		unsigned  lo	:32;
104		unsigned  hi	:32;
105	} fwords;
106	double	d;
107} _dval;
108
109/* single precision */
110typedef  union {
111	struct {
112		unsigned fract	:23;
113		unsigned exp	:8;
114		unsigned sign	:1;
115	} fparts;
116	struct {
117		unsigned fract	:22;
118		unsigned qnan_bit	:1;
119		unsigned exp	:8;
120		unsigned sign	:1;
121	} nparts;
122	unsigned long	fword;
123	float	f;
124} _fval;
125#endif
126
127/* parts of a double precision floating point number */
128#define	SIGNBIT(X)	(((_dval *)&(X))->fparts.sign)
129#define	EXPONENT(X)	(((_dval *)&(X))->fparts.exp)
130
131#define	HIFRACTION(X)	(((_dval *)&(X))->fparts.hi)
132#define	LOFRACTION(X)	(((_dval *)&(X))->fparts.lo)
133#define	QNANBIT(X)	(((_dval *)&(X))->nparts.qnan_bit)
134#define	HIWORD(X)	(((_dval *)&(X))->fwords.hi)
135#define	LOWORD(X)	(((_dval *)&(X))->fwords.lo)
136
137#define	MAXEXP	0x7ff /* maximum exponent of double */
138#define	ISMAXEXP(X)	((EXPONENT(X)) == MAXEXP)
139
140/* macros used to create quiet NaNs as return values */
141#define	SETQNAN(X)	((((_dval *)&(X))->nparts.qnan_bit) = 0x1)
142#define	HIQNAN(X)	((HIWORD(X)) = 0x7ff80000)
143#define	LOQNAN(X)	((((_dval *)&(X))->fwords.lo) = 0x0)
144
145/* macros used to extract parts of single precision values */
146#define	FSIGNBIT(X)	(((_fval *)&(X))->fparts.sign)
147#define	FEXPONENT(X)	(((_fval *)&(X))->fparts.exp)
148#define	FFRACTION(X)	(((_fval *)&(X))->fparts.fract)
149
150#define	FWORD(X)	(((_fval *)&(X))->fword)
151#define	FQNANBIT(X)	(((_fval *)&(X))->nparts.qnan_bit)
152#define	MAXEXPF	255 /* maximum exponent of single */
153#define	FISMAXEXP(X)	((FEXPONENT(X)) == MAXEXPF)
154
155#endif  /* _IEEE */
156