1 /*
2 * MIPS floating point support
3 * Copyright (C) 1994-2000 Algorithmics Ltd.
4 *
5 * This program is free software; you can distribute it and/or modify it
6 * under the terms of the GNU General Public License (Version 2) as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Nov 7, 2000
19 * Modification to allow integration with Linux kernel
20 *
21 * Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
22 * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
23 */
24 #ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
25 #define __ARCH_MIPS_MATH_EMU_IEEE754_H
26
27 #include <linux/compiler.h>
28 #include <asm/byteorder.h>
29 #include <linux/kernel.h>
30 #include <linux/types.h>
31 #include <linux/sched.h>
32 #include <asm/bitfield.h>
33
34 union ieee754dp {
35 struct {
36 __BITFIELD_FIELD(unsigned int sign:1,
37 __BITFIELD_FIELD(unsigned int bexp:11,
38 __BITFIELD_FIELD(u64 mant:52,
39 ;)))
40 };
41 u64 bits;
42 };
43
44 union ieee754sp {
45 struct {
46 __BITFIELD_FIELD(unsigned sign:1,
47 __BITFIELD_FIELD(unsigned bexp:8,
48 __BITFIELD_FIELD(unsigned mant:23,
49 ;)))
50 };
51 u32 bits;
52 };
53
54 /*
55 * single precision (often aka float)
56 */
57 int ieee754sp_class(union ieee754sp x);
58
59 union ieee754sp ieee754sp_abs(union ieee754sp x);
60 union ieee754sp ieee754sp_neg(union ieee754sp x);
61
62 union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y);
63 union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y);
64 union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y);
65 union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y);
66
67 union ieee754sp ieee754sp_fint(int x);
68 union ieee754sp ieee754sp_flong(s64 x);
69 union ieee754sp ieee754sp_fdp(union ieee754dp x);
70
71 int ieee754sp_tint(union ieee754sp x);
72 s64 ieee754sp_tlong(union ieee754sp x);
73
74 int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
75
76 union ieee754sp ieee754sp_sqrt(union ieee754sp x);
77
78 /*
79 * double precision (often aka double)
80 */
81 int ieee754dp_class(union ieee754dp x);
82
83 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
84 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
85 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
86 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
87
88 union ieee754dp ieee754dp_abs(union ieee754dp x);
89 union ieee754dp ieee754dp_neg(union ieee754dp x);
90
91 union ieee754dp ieee754dp_fint(int x);
92 union ieee754dp ieee754dp_flong(s64 x);
93 union ieee754dp ieee754dp_fsp(union ieee754sp x);
94
95 int ieee754dp_tint(union ieee754dp x);
96 s64 ieee754dp_tlong(union ieee754dp x);
97
98 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
99
100 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
101
102
103
104 /* 5 types of floating point number
105 */
106 enum {
107 IEEE754_CLASS_NORM = 0x00,
108 IEEE754_CLASS_ZERO = 0x01,
109 IEEE754_CLASS_DNORM = 0x02,
110 IEEE754_CLASS_INF = 0x03,
111 IEEE754_CLASS_SNAN = 0x04,
112 IEEE754_CLASS_QNAN = 0x05,
113 };
114
115 /* exception numbers */
116 #define IEEE754_INEXACT 0x01
117 #define IEEE754_UNDERFLOW 0x02
118 #define IEEE754_OVERFLOW 0x04
119 #define IEEE754_ZERO_DIVIDE 0x08
120 #define IEEE754_INVALID_OPERATION 0x10
121
122 /* cmp operators
123 */
124 #define IEEE754_CLT 0x01
125 #define IEEE754_CEQ 0x02
126 #define IEEE754_CGT 0x04
127 #define IEEE754_CUN 0x08
128
129 /*
130 * The control status register
131 */
132 struct _ieee754_csr {
133 __BITFIELD_FIELD(unsigned fcc:7, /* condition[7:1] */
134 __BITFIELD_FIELD(unsigned nod:1, /* set 1 for no denormals */
135 __BITFIELD_FIELD(unsigned c:1, /* condition[0] */
136 __BITFIELD_FIELD(unsigned pad0:3,
137 __BITFIELD_FIELD(unsigned abs2008:1, /* IEEE 754-2008 ABS/NEG.fmt */
138 __BITFIELD_FIELD(unsigned nan2008:1, /* IEEE 754-2008 NaN mode */
139 __BITFIELD_FIELD(unsigned cx:6, /* exceptions this operation */
140 __BITFIELD_FIELD(unsigned mx:5, /* exception enable mask */
141 __BITFIELD_FIELD(unsigned sx:5, /* exceptions total */
142 __BITFIELD_FIELD(unsigned rm:2, /* current rounding mode */
143 ;))))))))))
144 };
145 #define ieee754_csr (*(struct _ieee754_csr *)(¤t->thread.fpu.fcr31))
146
ieee754_getrm(void)147 static inline unsigned ieee754_getrm(void)
148 {
149 return (ieee754_csr.rm);
150 }
ieee754_setrm(unsigned rm)151 static inline unsigned ieee754_setrm(unsigned rm)
152 {
153 return (ieee754_csr.rm = rm);
154 }
155
156 /*
157 * get current exceptions
158 */
ieee754_getcx(void)159 static inline unsigned ieee754_getcx(void)
160 {
161 return (ieee754_csr.cx);
162 }
163
164 /* test for current exception condition
165 */
ieee754_cxtest(unsigned n)166 static inline int ieee754_cxtest(unsigned n)
167 {
168 return (ieee754_csr.cx & n);
169 }
170
171 /*
172 * get sticky exceptions
173 */
ieee754_getsx(void)174 static inline unsigned ieee754_getsx(void)
175 {
176 return (ieee754_csr.sx);
177 }
178
179 /* clear sticky conditions
180 */
ieee754_clrsx(void)181 static inline unsigned ieee754_clrsx(void)
182 {
183 return (ieee754_csr.sx = 0);
184 }
185
186 /* test for sticky exception condition
187 */
ieee754_sxtest(unsigned n)188 static inline int ieee754_sxtest(unsigned n)
189 {
190 return (ieee754_csr.sx & n);
191 }
192
193 /* debugging */
194 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
195 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
196
197 #define IEEE754_SPCVAL_PZERO 0 /* +0.0 */
198 #define IEEE754_SPCVAL_NZERO 1 /* -0.0 */
199 #define IEEE754_SPCVAL_PONE 2 /* +1.0 */
200 #define IEEE754_SPCVAL_NONE 3 /* -1.0 */
201 #define IEEE754_SPCVAL_PTEN 4 /* +10.0 */
202 #define IEEE754_SPCVAL_NTEN 5 /* -10.0 */
203 #define IEEE754_SPCVAL_PINFINITY 6 /* +inf */
204 #define IEEE754_SPCVAL_NINFINITY 7 /* -inf */
205 #define IEEE754_SPCVAL_INDEF 8 /* quiet NaN */
206 #define IEEE754_SPCVAL_PMAX 9 /* +max norm */
207 #define IEEE754_SPCVAL_NMAX 10 /* -max norm */
208 #define IEEE754_SPCVAL_PMIN 11 /* +min norm */
209 #define IEEE754_SPCVAL_NMIN 12 /* -min norm */
210 #define IEEE754_SPCVAL_PMIND 13 /* +min denorm */
211 #define IEEE754_SPCVAL_NMIND 14 /* -min denorm */
212 #define IEEE754_SPCVAL_P1E31 15 /* + 1.0e31 */
213 #define IEEE754_SPCVAL_P1E63 16 /* + 1.0e63 */
214
215 extern const union ieee754dp __ieee754dp_spcvals[];
216 extern const union ieee754sp __ieee754sp_spcvals[];
217 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
218 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
219
220 /*
221 * Return infinity with given sign
222 */
223 #define ieee754dp_inf(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
224 #define ieee754dp_zero(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
225 #define ieee754dp_one(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
226 #define ieee754dp_ten(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
227 #define ieee754dp_indef() (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
228 #define ieee754dp_max(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
229 #define ieee754dp_min(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
230 #define ieee754dp_mind(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
231 #define ieee754dp_1e31() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
232 #define ieee754dp_1e63() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
233
234 #define ieee754sp_inf(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
235 #define ieee754sp_zero(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
236 #define ieee754sp_one(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
237 #define ieee754sp_ten(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
238 #define ieee754sp_indef() (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
239 #define ieee754sp_max(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
240 #define ieee754sp_min(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
241 #define ieee754sp_mind(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
242 #define ieee754sp_1e31() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
243 #define ieee754sp_1e63() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
244
245 /*
246 * Indefinite integer value
247 */
ieee754si_indef(void)248 static inline int ieee754si_indef(void)
249 {
250 return INT_MAX;
251 }
252
ieee754di_indef(void)253 static inline s64 ieee754di_indef(void)
254 {
255 return S64_MAX;
256 }
257
258 /* result types for xctx.rt */
259 #define IEEE754_RT_SP 0
260 #define IEEE754_RT_DP 1
261 #define IEEE754_RT_XP 2
262 #define IEEE754_RT_SI 3
263 #define IEEE754_RT_DI 4
264
265 /* compat */
266 #define ieee754dp_fix(x) ieee754dp_tint(x)
267 #define ieee754sp_fix(x) ieee754sp_tint(x)
268
269 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */
270