xref: /netbsd-src/sys/arch/sparc/include/ieee.h (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: ieee.h,v 1.17 2013/12/15 03:45:07 christos 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 
64 struct ieee_ext {
65 	/*LINTED35*/	uint64_t	ext_sign:1;
66 	/*LINTED35*/	uint64_t	ext_exp:EXT_EXPBITS;
67 	/*LINTED35*/	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  */
110 union 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