File: /usr/src/linux/arch/mips64/math-emu/ieee754.c
1 /* ieee754 floating point arithmetic
2 * single and double precision
3 *
4 * BUGS
5 * not much dp done
6 * doesnt generate IEEE754_INEXACT
7 *
8 */
9 /*
10 * MIPS floating point support
11 * Copyright (C) 1994-2000 Algorithmics Ltd. All rights reserved.
12 * http://www.algor.co.uk
13 *
14 * ########################################################################
15 *
16 * This program is free software; you can distribute it and/or modify it
17 * under the terms of the GNU General Public License (Version 2) as
18 * published by the Free Software Foundation.
19 *
20 * This program is distributed in the hope it will be useful, but WITHOUT
21 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
22 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
23 * for more details.
24 *
25 * You should have received a copy of the GNU General Public License along
26 * with this program; if not, write to the Free Software Foundation, Inc.,
27 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
28 *
29 * ########################################################################
30 */
31
32
33 #include "ieee754int.h"
34
35 #define DP_EBIAS 1023
36 #define DP_EMIN (-1022)
37 #define DP_EMAX 1023
38
39 #define SP_EBIAS 127
40 #define SP_EMIN (-126)
41 #define SP_EMAX 127
42
43 /* indexed by class */
44 const char *const ieee754_cname[] = {
45 "Normal",
46 "Zero",
47 "Denormal",
48 "Infinity",
49 "QNaN",
50 "SNaN",
51 };
52
53 /* the control status register
54 */
55 struct ieee754_csr ieee754_csr;
56
57 /* special constants
58 */
59
60
61 #if (defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN) || defined(__MIPSEL__)
62 #define SPSTR(s,b,m) {m,b,s}
63 #define DPSTR(s,b,mh,ml) {ml,mh,b,s}
64 #endif
65
66 #ifdef __MIPSEB__
67 #define SPSTR(s,b,m) {s,b,m}
68 #define DPSTR(s,b,mh,ml) {s,b,mh,ml}
69 #endif
70
71 const struct ieee754dp_konst __ieee754dp_spcvals[] = {
72 DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* + zero */
73 DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* - zero */
74 DPSTR(0, DP_EBIAS, 0, 0), /* + 1.0 */
75 DPSTR(1, DP_EBIAS, 0, 0), /* - 1.0 */
76 DPSTR(0, 3 + DP_EBIAS, 0x40000, 0), /* + 10.0 */
77 DPSTR(1, 3 + DP_EBIAS, 0x40000, 0), /* - 10.0 */
78 DPSTR(0, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* + infinity */
79 DPSTR(1, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* - infinity */
80 DPSTR(0, DP_EMAX + 1 + DP_EBIAS, 0x40000, 0), /* + indef quiet Nan */
81 DPSTR(0, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF), /* + max */
82 DPSTR(1, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF), /* - max */
83 DPSTR(0, DP_EMIN + DP_EBIAS, 0, 0), /* + min normal */
84 DPSTR(1, DP_EMIN + DP_EBIAS, 0, 0), /* - min normal */
85 DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* + min denormal */
86 DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* - min denormal */
87 DPSTR(0, 31 + DP_EBIAS, 0, 0), /* + 1.0e31 */
88 DPSTR(0, 63 + DP_EBIAS, 0, 0), /* + 1.0e63 */
89 };
90
91 const struct ieee754sp_konst __ieee754sp_spcvals[] = {
92 SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 0), /* + zero */
93 SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 0), /* - zero */
94 SPSTR(0, SP_EBIAS, 0), /* + 1.0 */
95 SPSTR(1, SP_EBIAS, 0), /* - 1.0 */
96 SPSTR(0, 3 + SP_EBIAS, 0x200000), /* + 10.0 */
97 SPSTR(1, 3 + SP_EBIAS, 0x200000), /* - 10.0 */
98 SPSTR(0, SP_EMAX + 1 + SP_EBIAS, 0), /* + infinity */
99 SPSTR(1, SP_EMAX + 1 + SP_EBIAS, 0), /* - infinity */
100 SPSTR(0, SP_EMAX + 1 + SP_EBIAS, 0x200000), /* + indef quiet Nan */
101 SPSTR(0, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* + max normal */
102 SPSTR(1, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* - max normal */
103 SPSTR(0, SP_EMIN + SP_EBIAS, 0), /* + min normal */
104 SPSTR(1, SP_EMIN + SP_EBIAS, 0), /* - min normal */
105 SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 1), /* + min denormal */
106 SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 1), /* - min denormal */
107 SPSTR(0, 31 + SP_EBIAS, 0), /* + 1.0e31 */
108 SPSTR(0, 63 + SP_EBIAS, 0), /* + 1.0e63 */
109 };
110
111
112 int ieee754si_xcpt(int r, const char *op, ...)
113 {
114 struct ieee754xctx ax;
115
116 if (!TSTX())
117 return r;
118 ax.op = op;
119 ax.rt = IEEE754_RT_SI;
120 ax.rv.si = r;
121 va_start(ax.ap, op);
122 ieee754_xcpt(&ax);
123 return ax.rv.si;
124 }
125
126 long long ieee754di_xcpt(long long r, const char *op, ...)
127 {
128 struct ieee754xctx ax;
129
130 if (!TSTX())
131 return r;
132 ax.op = op;
133 ax.rt = IEEE754_RT_DI;
134 ax.rv.di = r;
135 va_start(ax.ap, op);
136 ieee754_xcpt(&ax);
137 return ax.rv.di;
138 }
139