ieee.h revision 1.16 
1/*	$NetBSD: ieee.h,v 1.16 2013/11/20 22:22:20 martin Exp $	*/
2
3/*
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * All advertising materials mentioning features or use of this software
12 * must display the following acknowledgement:
13 *	This product includes software developed by the University of
14 *	California, Lawrence Berkeley Laboratory.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 *    notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 *    notice, this list of conditions and the following disclaimer in the
23 *    documentation and/or other materials provided with the distribution.
24 * 3. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 *	@(#)ieee.h	8.1 (Berkeley) 6/11/93
41 */
42
43/*
44 * ieee.h defines the machine-dependent layout of the machine's IEEE
45 * floating point.  It does *not* define (yet?) any of the rounding
46 * mode bits, exceptions, and so forth.
47 */
48
49#include <sys/ieee754.h>
50
51/*
52 * The SPARC architecture defines the following IEEE 754 compliant
53 * 128-bit extended-precision format, which is supported only by the
54 * v9 toolchain.
55 */
56
57#if defined(__arch64__) || defined(_KERNEL)
58
59#define	EXT_EXPBITS	15
60#define EXT_FRACHBITS	(16+32)
61#define	EXT_FRACLBITS	(32+32)
62#define	EXT_FRACBITS	(EXT_FRACLBITS + EXT_FRACHBITS)
63
64struct ieee_ext {
65	uint64_t	ext_sign:1;
66	uint64_t	ext_exp:EXT_EXPBITS;
67	uint64_t	ext_frach:EXT_FRACHBITS;
68	uint64_t	ext_fracl;
69};
70__CTASSERT(sizeof(struct ieee_ext) == 16);
71
72/*
73 * Copy all mantissa bits to an array of uint32_t big enough to hold them all.
74 * This is an insane API (seems to only be needed in gdtoa).
75 */
76#define EXT_TO_ARRAY32(u, a) do {					\
77	(a)[0] = (uint32_t)((u).extu_ext.ext_fracl & 0x0ffffffffL);	\
78	(a)[1] = (uint32_t)((u).extu_ext.ext_fracl >> 32);		\
79	(a)[2] = (uint32_t)((u).extu_ext.ext_frach & 0x0ffffffffL);	\
80	(a)[3] = (uint32_t)((u).extu_ext.ext_frach >> 32) & 0x0ffff;	\
81} while(/*CONSTCOND*/0)
82
83/*
84 * Floats whose exponent is in [1..INFNAN) (of whatever type) are
85 * `normal'.  Floats whose exponent is INFNAN are either Inf or NaN.
86 * Floats whose exponent is zero are either zero (iff all fraction
87 * bits are zero) or subnormal values.
88 *
89 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
90 * high fraction; if the bit is set, it is a `quiet NaN'.
91 */
92#define	EXT_EXP_INFNAN	0x7fff
93#define	EXT_EXP_INF	0x7fff
94#define	EXT_EXP_NAN	0x7fff
95
96#if 0
97#define	SNG_QUIETNAN	(1 << 22)
98#define	DBL_QUIETNAN	(1 << 19)
99#define	EXT_QUIETNAN	(1 << 15)
100#endif
101
102/*
103 * Exponent biases.
104 */
105#define	EXT_EXP_BIAS	16383
106
107/*
108 * Convenience data structures.
109 */
110union ieee_ext_u {
111	long double		extu_ld;
112	struct ieee_ext		extu_ext;
113};
114
115#define extu_exp	extu_ext.ext_exp
116#define extu_sign	extu_ext.ext_sign
117#define extu_fracl	extu_ext.ext_fracl
118#define extu_fraclm	extu_ext.ext_fraclm
119#define extu_frachm	extu_ext.ext_frachm
120#define extu_frach	extu_ext.ext_frach
121
122#define	LDBL_IMPLICIT_NBIT	1
123
124#endif /* __arch64__ || _KERNEL */
125