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 union ieee754sp ieee754sp_maddf(union ieee754sp z, union ieee754sp x,
79 union ieee754sp y);
80 union ieee754sp ieee754sp_msubf(union ieee754sp z, union ieee754sp x,
81 union ieee754sp y);
82 int ieee754sp_2008class(union ieee754sp x);
83 union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y);
84 union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y);
85 union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y);
86 union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y);
87
88 /*
89 * double precision (often aka double)
90 */
91 int ieee754dp_class(union ieee754dp x);
92
93 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
94 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
95 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
96 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
97
98 union ieee754dp ieee754dp_abs(union ieee754dp x);
99 union ieee754dp ieee754dp_neg(union ieee754dp x);
100
101 union ieee754dp ieee754dp_fint(int x);
102 union ieee754dp ieee754dp_flong(s64 x);
103 union ieee754dp ieee754dp_fsp(union ieee754sp x);
104
105 int ieee754dp_tint(union ieee754dp x);
106 s64 ieee754dp_tlong(union ieee754dp x);
107
108 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
109
110 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
111
112 union ieee754dp ieee754dp_maddf(union ieee754dp z, union ieee754dp x,
113 union ieee754dp y);
114 union ieee754dp ieee754dp_msubf(union ieee754dp z, union ieee754dp x,
115 union ieee754dp y);
116 int ieee754dp_2008class(union ieee754dp x);
117 union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y);
118 union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y);
119 union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y);
120 union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y);
121
122
123 /* 5 types of floating point number
124 */
125 enum {
126 IEEE754_CLASS_NORM = 0x00,
127 IEEE754_CLASS_ZERO = 0x01,
128 IEEE754_CLASS_DNORM = 0x02,
129 IEEE754_CLASS_INF = 0x03,
130 IEEE754_CLASS_SNAN = 0x04,
131 IEEE754_CLASS_QNAN = 0x05,
132 };
133
134 /* exception numbers */
135 #define IEEE754_INEXACT 0x01
136 #define IEEE754_UNDERFLOW 0x02
137 #define IEEE754_OVERFLOW 0x04
138 #define IEEE754_ZERO_DIVIDE 0x08
139 #define IEEE754_INVALID_OPERATION 0x10
140
141 /* cmp operators
142 */
143 #define IEEE754_CLT 0x01
144 #define IEEE754_CEQ 0x02
145 #define IEEE754_CGT 0x04
146 #define IEEE754_CUN 0x08
147
148 /*
149 * The control status register
150 */
151 struct _ieee754_csr {
152 __BITFIELD_FIELD(unsigned fcc:7, /* condition[7:1] */
153 __BITFIELD_FIELD(unsigned nod:1, /* set 1 for no denormals */
154 __BITFIELD_FIELD(unsigned c:1, /* condition[0] */
155 __BITFIELD_FIELD(unsigned pad0:3,
156 __BITFIELD_FIELD(unsigned abs2008:1, /* IEEE 754-2008 ABS/NEG.fmt */
157 __BITFIELD_FIELD(unsigned nan2008:1, /* IEEE 754-2008 NaN mode */
158 __BITFIELD_FIELD(unsigned cx:6, /* exceptions this operation */
159 __BITFIELD_FIELD(unsigned mx:5, /* exception enable mask */
160 __BITFIELD_FIELD(unsigned sx:5, /* exceptions total */
161 __BITFIELD_FIELD(unsigned rm:2, /* current rounding mode */
162 ;))))))))))
163 };
164 #define ieee754_csr (*(struct _ieee754_csr *)(¤t->thread.fpu.fcr31))
165
ieee754_getrm(void)166 static inline unsigned ieee754_getrm(void)
167 {
168 return (ieee754_csr.rm);
169 }
ieee754_setrm(unsigned rm)170 static inline unsigned ieee754_setrm(unsigned rm)
171 {
172 return (ieee754_csr.rm = rm);
173 }
174
175 /*
176 * get current exceptions
177 */
ieee754_getcx(void)178 static inline unsigned ieee754_getcx(void)
179 {
180 return (ieee754_csr.cx);
181 }
182
183 /* test for current exception condition
184 */
ieee754_cxtest(unsigned n)185 static inline int ieee754_cxtest(unsigned n)
186 {
187 return (ieee754_csr.cx & n);
188 }
189
190 /*
191 * get sticky exceptions
192 */
ieee754_getsx(void)193 static inline unsigned ieee754_getsx(void)
194 {
195 return (ieee754_csr.sx);
196 }
197
198 /* clear sticky conditions
199 */
ieee754_clrsx(void)200 static inline unsigned ieee754_clrsx(void)
201 {
202 return (ieee754_csr.sx = 0);
203 }
204
205 /* test for sticky exception condition
206 */
ieee754_sxtest(unsigned n)207 static inline int ieee754_sxtest(unsigned n)
208 {
209 return (ieee754_csr.sx & n);
210 }
211
212 /* debugging */
213 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
214 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
215
216 #define IEEE754_SPCVAL_PZERO 0 /* +0.0 */
217 #define IEEE754_SPCVAL_NZERO 1 /* -0.0 */
218 #define IEEE754_SPCVAL_PONE 2 /* +1.0 */
219 #define IEEE754_SPCVAL_NONE 3 /* -1.0 */
220 #define IEEE754_SPCVAL_PTEN 4 /* +10.0 */
221 #define IEEE754_SPCVAL_NTEN 5 /* -10.0 */
222 #define IEEE754_SPCVAL_PINFINITY 6 /* +inf */
223 #define IEEE754_SPCVAL_NINFINITY 7 /* -inf */
224 #define IEEE754_SPCVAL_INDEF_LEG 8 /* legacy quiet NaN */
225 #define IEEE754_SPCVAL_INDEF_2008 9 /* IEEE 754-2008 quiet NaN */
226 #define IEEE754_SPCVAL_PMAX 10 /* +max norm */
227 #define IEEE754_SPCVAL_NMAX 11 /* -max norm */
228 #define IEEE754_SPCVAL_PMIN 12 /* +min norm */
229 #define IEEE754_SPCVAL_NMIN 13 /* -min norm */
230 #define IEEE754_SPCVAL_PMIND 14 /* +min denorm */
231 #define IEEE754_SPCVAL_NMIND 15 /* -min denorm */
232 #define IEEE754_SPCVAL_P1E31 16 /* + 1.0e31 */
233 #define IEEE754_SPCVAL_P1E63 17 /* + 1.0e63 */
234
235 extern const union ieee754dp __ieee754dp_spcvals[];
236 extern const union ieee754sp __ieee754sp_spcvals[];
237 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
238 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
239
240 /*
241 * Return infinity with given sign
242 */
243 #define ieee754dp_inf(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
244 #define ieee754dp_zero(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
245 #define ieee754dp_one(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
246 #define ieee754dp_ten(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
247 #define ieee754dp_indef() (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
248 ieee754_csr.nan2008])
249 #define ieee754dp_max(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
250 #define ieee754dp_min(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
251 #define ieee754dp_mind(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
252 #define ieee754dp_1e31() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
253 #define ieee754dp_1e63() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
254
255 #define ieee754sp_inf(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
256 #define ieee754sp_zero(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
257 #define ieee754sp_one(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
258 #define ieee754sp_ten(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
259 #define ieee754sp_indef() (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
260 ieee754_csr.nan2008])
261 #define ieee754sp_max(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
262 #define ieee754sp_min(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
263 #define ieee754sp_mind(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
264 #define ieee754sp_1e31() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
265 #define ieee754sp_1e63() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
266
267 /*
268 * Indefinite integer value
269 */
ieee754si_indef(void)270 static inline int ieee754si_indef(void)
271 {
272 return ieee754_csr.nan2008 ? 0 : INT_MAX;
273 }
274
ieee754di_indef(void)275 static inline s64 ieee754di_indef(void)
276 {
277 return ieee754_csr.nan2008 ? 0 : S64_MAX;
278 }
279
280 /*
281 * Overflow integer value
282 */
ieee754si_overflow(int xs)283 static inline int ieee754si_overflow(int xs)
284 {
285 return ieee754_csr.nan2008 && xs ? INT_MIN : INT_MAX;
286 }
287
ieee754di_overflow(int xs)288 static inline s64 ieee754di_overflow(int xs)
289 {
290 return ieee754_csr.nan2008 && xs ? S64_MIN : S64_MAX;
291 }
292
293 /* result types for xctx.rt */
294 #define IEEE754_RT_SP 0
295 #define IEEE754_RT_DP 1
296 #define IEEE754_RT_XP 2
297 #define IEEE754_RT_SI 3
298 #define IEEE754_RT_DI 4
299
300 /* compat */
301 #define ieee754dp_fix(x) ieee754dp_tint(x)
302 #define ieee754sp_fix(x) ieee754sp_tint(x)
303
304 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */
305