Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
ieee754.h
Go to the documentation of this file.
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  * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
17  *
18  * Nov 7, 2000
19  * Modification to allow integration with Linux kernel
20  *
21  * Kevin D. Kissell, [email protected] and Carsten Langgard, [email protected]
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 <asm/byteorder.h>
28 #include <linux/types.h>
29 #include <linux/sched.h>
30 
31 /*
32  * Not very pretty, but the Linux kernel's normal va_list definition
33  * does not allow it to be used as a structure element, as it is here.
34  */
35 #ifndef _STDARG_H
36 #include <stdarg.h>
37 #endif
38 
39 #ifdef __LITTLE_ENDIAN
40 struct ieee754dp_konst {
41  unsigned mantlo:32;
42  unsigned manthi:20;
43  unsigned bexp:11;
44  unsigned sign:1;
45 };
46 struct ieee754sp_konst {
47  unsigned mant:23;
48  unsigned bexp:8;
49  unsigned sign:1;
50 };
51 
52 typedef union _ieee754dp {
53  struct ieee754dp_konst oparts;
54  struct {
55  u64 mant:52;
56  unsigned int bexp:11;
57  unsigned int sign:1;
58  } parts;
59  u64 bits;
60  double d;
61 } ieee754dp;
62 
63 typedef union _ieee754sp {
64  struct ieee754sp_konst parts;
65  float f;
66  u32 bits;
67 } ieee754sp;
68 #endif
69 
70 #ifdef __BIG_ENDIAN
71 struct ieee754dp_konst {
72  unsigned sign:1;
73  unsigned bexp:11;
74  unsigned manthi:20;
75  unsigned mantlo:32;
76 };
77 
78 typedef union _ieee754dp {
79  struct ieee754dp_konst oparts;
80  struct {
81  unsigned int sign:1;
82  unsigned int bexp:11;
83  u64 mant:52;
84  } parts;
85  double d;
86  u64 bits;
87 } ieee754dp;
88 
89 struct ieee754sp_konst {
90  unsigned sign:1;
91  unsigned bexp:8;
92  unsigned mant:23;
93 };
94 
95 typedef union _ieee754sp {
96  struct ieee754sp_konst parts;
97  float f;
98  u32 bits;
99 } ieee754sp;
100 #endif
101 
102 /*
103  * single precision (often aka float)
104 */
105 int ieee754sp_finite(ieee754sp x);
106 int ieee754sp_class(ieee754sp x);
107 
108 ieee754sp ieee754sp_abs(ieee754sp x);
109 ieee754sp ieee754sp_neg(ieee754sp x);
110 ieee754sp ieee754sp_scalb(ieee754sp x, int);
111 ieee754sp ieee754sp_logb(ieee754sp x);
112 
113 /* x with sign of y */
114 ieee754sp ieee754sp_copysign(ieee754sp x, ieee754sp y);
115 
116 ieee754sp ieee754sp_add(ieee754sp x, ieee754sp y);
117 ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y);
118 ieee754sp ieee754sp_mul(ieee754sp x, ieee754sp y);
119 ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y);
120 
121 ieee754sp ieee754sp_fint(int x);
122 ieee754sp ieee754sp_funs(unsigned x);
123 ieee754sp ieee754sp_flong(s64 x);
124 ieee754sp ieee754sp_fulong(u64 x);
125 ieee754sp ieee754sp_fdp(ieee754dp x);
126 
127 int ieee754sp_tint(ieee754sp x);
128 unsigned int ieee754sp_tuns(ieee754sp x);
129 s64 ieee754sp_tlong(ieee754sp x);
130 u64 ieee754sp_tulong(ieee754sp x);
131 
132 int ieee754sp_cmp(ieee754sp x, ieee754sp y, int cop, int sig);
133 /*
134  * basic sp math
135  */
136 ieee754sp ieee754sp_modf(ieee754sp x, ieee754sp * ip);
137 ieee754sp ieee754sp_frexp(ieee754sp x, int *exp);
138 ieee754sp ieee754sp_ldexp(ieee754sp x, int exp);
139 
140 ieee754sp ieee754sp_ceil(ieee754sp x);
141 ieee754sp ieee754sp_floor(ieee754sp x);
142 ieee754sp ieee754sp_trunc(ieee754sp x);
143 
144 ieee754sp ieee754sp_sqrt(ieee754sp x);
145 
146 /*
147  * double precision (often aka double)
148 */
149 int ieee754dp_finite(ieee754dp x);
150 int ieee754dp_class(ieee754dp x);
151 
152 /* x with sign of y */
153 ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y);
154 
155 ieee754dp ieee754dp_add(ieee754dp x, ieee754dp y);
156 ieee754dp ieee754dp_sub(ieee754dp x, ieee754dp y);
157 ieee754dp ieee754dp_mul(ieee754dp x, ieee754dp y);
158 ieee754dp ieee754dp_div(ieee754dp x, ieee754dp y);
159 
160 ieee754dp ieee754dp_abs(ieee754dp x);
161 ieee754dp ieee754dp_neg(ieee754dp x);
162 ieee754dp ieee754dp_scalb(ieee754dp x, int);
163 
164 /* return exponent as integer in floating point format
165  */
166 ieee754dp ieee754dp_logb(ieee754dp x);
167 
168 ieee754dp ieee754dp_fint(int x);
169 ieee754dp ieee754dp_funs(unsigned x);
170 ieee754dp ieee754dp_flong(s64 x);
171 ieee754dp ieee754dp_fulong(u64 x);
172 ieee754dp ieee754dp_fsp(ieee754sp x);
173 
174 ieee754dp ieee754dp_ceil(ieee754dp x);
175 ieee754dp ieee754dp_floor(ieee754dp x);
176 ieee754dp ieee754dp_trunc(ieee754dp x);
177 
178 int ieee754dp_tint(ieee754dp x);
179 unsigned int ieee754dp_tuns(ieee754dp x);
180 s64 ieee754dp_tlong(ieee754dp x);
181 u64 ieee754dp_tulong(ieee754dp x);
182 
183 int ieee754dp_cmp(ieee754dp x, ieee754dp y, int cop, int sig);
184 /*
185  * basic sp math
186  */
187 ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip);
188 ieee754dp ieee754dp_frexp(ieee754dp x, int *exp);
189 ieee754dp ieee754dp_ldexp(ieee754dp x, int exp);
190 
191 ieee754dp ieee754dp_ceil(ieee754dp x);
192 ieee754dp ieee754dp_floor(ieee754dp x);
193 ieee754dp ieee754dp_trunc(ieee754dp x);
194 
195 ieee754dp ieee754dp_sqrt(ieee754dp x);
196 
197 
198 
199 /* 5 types of floating point number
200 */
201 #define IEEE754_CLASS_NORM 0x00
202 #define IEEE754_CLASS_ZERO 0x01
203 #define IEEE754_CLASS_DNORM 0x02
204 #define IEEE754_CLASS_INF 0x03
205 #define IEEE754_CLASS_SNAN 0x04
206 #define IEEE754_CLASS_QNAN 0x05
207 
208 /* exception numbers */
209 #define IEEE754_INEXACT 0x01
210 #define IEEE754_UNDERFLOW 0x02
211 #define IEEE754_OVERFLOW 0x04
212 #define IEEE754_ZERO_DIVIDE 0x08
213 #define IEEE754_INVALID_OPERATION 0x10
214 
215 /* cmp operators
216 */
217 #define IEEE754_CLT 0x01
218 #define IEEE754_CEQ 0x02
219 #define IEEE754_CGT 0x04
220 #define IEEE754_CUN 0x08
221 
222 /* rounding mode
223 */
224 #define IEEE754_RN 0 /* round to nearest */
225 #define IEEE754_RZ 1 /* round toward zero */
226 #define IEEE754_RD 2 /* round toward -Infinity */
227 #define IEEE754_RU 3 /* round toward +Infinity */
228 
229 /* other naming */
230 #define IEEE754_RM IEEE754_RD
231 #define IEEE754_RP IEEE754_RU
232 
233 /* "normal" comparisons
234 */
235 static inline int ieee754sp_eq(ieee754sp x, ieee754sp y)
236 {
237  return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
238 }
239 
240 static inline int ieee754sp_ne(ieee754sp x, ieee754sp y)
241 {
242  return ieee754sp_cmp(x, y,
243  IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
244 }
245 
246 static inline int ieee754sp_lt(ieee754sp x, ieee754sp y)
247 {
248  return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
249 }
250 
251 static inline int ieee754sp_le(ieee754sp x, ieee754sp y)
252 {
253  return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
254 }
255 
256 static inline int ieee754sp_gt(ieee754sp x, ieee754sp y)
257 {
258  return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
259 }
260 
261 
262 static inline int ieee754sp_ge(ieee754sp x, ieee754sp y)
263 {
264  return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
265 }
266 
267 static inline int ieee754dp_eq(ieee754dp x, ieee754dp y)
268 {
269  return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
270 }
271 
272 static inline int ieee754dp_ne(ieee754dp x, ieee754dp y)
273 {
274  return ieee754dp_cmp(x, y,
275  IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
276 }
277 
278 static inline int ieee754dp_lt(ieee754dp x, ieee754dp y)
279 {
280  return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
281 }
282 
283 static inline int ieee754dp_le(ieee754dp x, ieee754dp y)
284 {
285  return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
286 }
287 
288 static inline int ieee754dp_gt(ieee754dp x, ieee754dp y)
289 {
290  return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
291 }
292 
293 static inline int ieee754dp_ge(ieee754dp x, ieee754dp y)
294 {
295  return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
296 }
297 
298 
299 /*
300  * Like strtod
301  */
302 ieee754dp ieee754dp_fstr(const char *s, char **endp);
303 char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af);
304 
305 
306 /*
307  * The control status register
308  */
309 struct _ieee754_csr {
310 #ifdef __BIG_ENDIAN
311  unsigned pad0:7;
312  unsigned nod:1; /* set 1 for no denormalised numbers */
313  unsigned c:1; /* condition */
314  unsigned pad1:5;
315  unsigned cx:6; /* exceptions this operation */
316  unsigned mx:5; /* exception enable mask */
317  unsigned sx:5; /* exceptions total */
318  unsigned rm:2; /* current rounding mode */
319 #endif
320 #ifdef __LITTLE_ENDIAN
321  unsigned rm:2; /* current rounding mode */
322  unsigned sx:5; /* exceptions total */
323  unsigned mx:5; /* exception enable mask */
324  unsigned cx:6; /* exceptions this operation */
325  unsigned pad1:5;
326  unsigned c:1; /* condition */
327  unsigned nod:1; /* set 1 for no denormalised numbers */
328  unsigned pad0:7;
329 #endif
330 };
331 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
332 
333 static inline unsigned ieee754_getrm(void)
334 {
335  return (ieee754_csr.rm);
336 }
337 static inline unsigned ieee754_setrm(unsigned rm)
338 {
339  return (ieee754_csr.rm = rm);
340 }
341 
342 /*
343  * get current exceptions
344  */
345 static inline unsigned ieee754_getcx(void)
346 {
347  return (ieee754_csr.cx);
348 }
349 
350 /* test for current exception condition
351  */
352 static inline int ieee754_cxtest(unsigned n)
353 {
354  return (ieee754_csr.cx & n);
355 }
356 
357 /*
358  * get sticky exceptions
359  */
360 static inline unsigned ieee754_getsx(void)
361 {
362  return (ieee754_csr.sx);
363 }
364 
365 /* clear sticky conditions
366 */
367 static inline unsigned ieee754_clrsx(void)
368 {
369  return (ieee754_csr.sx = 0);
370 }
371 
372 /* test for sticky exception condition
373  */
374 static inline int ieee754_sxtest(unsigned n)
375 {
376  return (ieee754_csr.sx & n);
377 }
378 
379 /* debugging */
380 ieee754sp ieee754sp_dump(char *s, ieee754sp x);
381 ieee754dp ieee754dp_dump(char *s, ieee754dp x);
382 
383 #define IEEE754_SPCVAL_PZERO 0
384 #define IEEE754_SPCVAL_NZERO 1
385 #define IEEE754_SPCVAL_PONE 2
386 #define IEEE754_SPCVAL_NONE 3
387 #define IEEE754_SPCVAL_PTEN 4
388 #define IEEE754_SPCVAL_NTEN 5
389 #define IEEE754_SPCVAL_PINFINITY 6
390 #define IEEE754_SPCVAL_NINFINITY 7
391 #define IEEE754_SPCVAL_INDEF 8
392 #define IEEE754_SPCVAL_PMAX 9 /* +max norm */
393 #define IEEE754_SPCVAL_NMAX 10 /* -max norm */
394 #define IEEE754_SPCVAL_PMIN 11 /* +min norm */
395 #define IEEE754_SPCVAL_NMIN 12 /* +min norm */
396 #define IEEE754_SPCVAL_PMIND 13 /* +min denorm */
397 #define IEEE754_SPCVAL_NMIND 14 /* +min denorm */
398 #define IEEE754_SPCVAL_P1E31 15 /* + 1.0e31 */
399 #define IEEE754_SPCVAL_P1E63 16 /* + 1.0e63 */
400 
401 extern const struct ieee754dp_konst __ieee754dp_spcvals[];
402 extern const struct ieee754sp_konst __ieee754sp_spcvals[];
403 #define ieee754dp_spcvals ((const ieee754dp *)__ieee754dp_spcvals)
404 #define ieee754sp_spcvals ((const ieee754sp *)__ieee754sp_spcvals)
405 
406 /*
407  * Return infinity with given sign
408  */
409 #define ieee754dp_inf(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
410 #define ieee754dp_zero(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
411 #define ieee754dp_one(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
412 #define ieee754dp_ten(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
413 #define ieee754dp_indef() (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
414 #define ieee754dp_max(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
415 #define ieee754dp_min(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
416 #define ieee754dp_mind(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
417 #define ieee754dp_1e31() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
418 #define ieee754dp_1e63() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
419 
420 #define ieee754sp_inf(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
421 #define ieee754sp_zero(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
422 #define ieee754sp_one(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
423 #define ieee754sp_ten(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
424 #define ieee754sp_indef() (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
425 #define ieee754sp_max(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
426 #define ieee754sp_min(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
427 #define ieee754sp_mind(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
428 #define ieee754sp_1e31() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
429 #define ieee754sp_1e63() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
430 
431 /*
432  * Indefinite integer value
433  */
434 #define ieee754si_indef() INT_MAX
435 #ifdef LONG_LONG_MAX
436 #define ieee754di_indef() LONG_LONG_MAX
437 #else
438 #define ieee754di_indef() ((s64)(~0ULL>>1))
439 #endif
440 
441 /* IEEE exception context, passed to handler */
442 struct ieee754xctx {
443  const char *op; /* operation name */
444  int rt; /* result type */
445  union {
446  ieee754sp sp; /* single precision */
447  ieee754dp dp; /* double precision */
448 #ifdef IEEE854_XP
449  ieee754xp xp; /* extended precision */
450 #endif
451  int si; /* standard signed integer (32bits) */
452  s64 di; /* extended signed integer (64bits) */
453  } rv; /* default result format implied by op */
454  va_list ap;
455 };
456 
457 /* result types for xctx.rt */
458 #define IEEE754_RT_SP 0
459 #define IEEE754_RT_DP 1
460 #define IEEE754_RT_XP 2
461 #define IEEE754_RT_SI 3
462 #define IEEE754_RT_DI 4
463 
464 extern void ieee754_xcpt(struct ieee754xctx *xcp);
465 
466 /* compat */
467 #define ieee754dp_fix(x) ieee754dp_tint(x)
468 #define ieee754sp_fix(x) ieee754sp_tint(x)
469 
470 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */
Generated on Thu Jan 10 2013 13:11:39 for Linux Kernel by   doxygen 1.8.2