1/*
2 * MIPS floating point support
3 * Copyright (C) 1994-2000 Algorithmics Ltd.
4 * http://www.algor.co.uk
5 *
6 *  This program is free software; you can distribute it and/or modify it
7 *  under the terms of the GNU General Public License (Version 2) as
8 *  published by the Free Software Foundation.
9 *
10 *  This program is distributed in the hope it will be useful, but WITHOUT
11 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 *  for more details.
14 *
15 *  You should have received a copy of the GNU General Public License along
16 *  with this program; if not, write to the Free Software Foundation, Inc.,
17 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
18 *
19 *  Nov 7, 2000
20 *  Modification to allow integration with Linux kernel
21 *
22 *  Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
23 *  Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
24 */
25#ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
26#define __ARCH_MIPS_MATH_EMU_IEEE754_H
27
28#include <asm/byteorder.h>
29#include <linux/types.h>
30#include <linux/sched.h>
31
32/*
33 * Not very pretty, but the Linux kernel's normal va_list definition
34 * does not allow it to be used as a structure element, as it is here.
35 */
36#ifndef _STDARG_H
37#include <stdarg.h>
38#endif
39
40#ifdef __LITTLE_ENDIAN
41struct ieee754dp_konst {
42	unsigned mantlo:32;
43	unsigned manthi:20;
44	unsigned bexp:11;
45	unsigned sign:1;
46};
47struct ieee754sp_konst {
48	unsigned mant:23;
49	unsigned bexp:8;
50	unsigned sign:1;
51};
52
53typedef union _ieee754dp {
54	struct ieee754dp_konst oparts;
55	struct {
56		u64 mant:52;
57		unsigned int bexp:11;
58		unsigned int sign:1;
59	} parts;
60	u64 bits;
61	double d;
62} ieee754dp;
63
64typedef union _ieee754sp {
65	struct ieee754sp_konst parts;
66	float f;
67	u32 bits;
68} ieee754sp;
69#endif
70
71#ifdef __BIG_ENDIAN
72struct ieee754dp_konst {
73	unsigned sign:1;
74	unsigned bexp:11;
75	unsigned manthi:20;
76	unsigned mantlo:32;
77};
78
79typedef union _ieee754dp {
80	struct ieee754dp_konst oparts;
81	struct {
82		unsigned int sign:1;
83		unsigned int bexp:11;
84		u64 mant:52;
85	} parts;
86	double d;
87	u64 bits;
88} ieee754dp;
89
90struct ieee754sp_konst {
91	unsigned sign:1;
92	unsigned bexp:8;
93	unsigned mant:23;
94};
95
96typedef union _ieee754sp {
97	struct ieee754sp_konst parts;
98	float f;
99	u32 bits;
100} ieee754sp;
101#endif
102
103/*
104 * single precision (often aka float)
105*/
106int ieee754sp_finite(ieee754sp x);
107int ieee754sp_class(ieee754sp x);
108
109ieee754sp ieee754sp_abs(ieee754sp x);
110ieee754sp ieee754sp_neg(ieee754sp x);
111ieee754sp ieee754sp_scalb(ieee754sp x, int);
112ieee754sp ieee754sp_logb(ieee754sp x);
113
114/* x with sign of y */
115ieee754sp ieee754sp_copysign(ieee754sp x, ieee754sp y);
116
117ieee754sp ieee754sp_add(ieee754sp x, ieee754sp y);
118ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y);
119ieee754sp ieee754sp_mul(ieee754sp x, ieee754sp y);
120ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y);
121
122ieee754sp ieee754sp_fint(int x);
123ieee754sp ieee754sp_funs(unsigned x);
124ieee754sp ieee754sp_flong(s64 x);
125ieee754sp ieee754sp_fulong(u64 x);
126ieee754sp ieee754sp_fdp(ieee754dp x);
127
128int ieee754sp_tint(ieee754sp x);
129unsigned int ieee754sp_tuns(ieee754sp x);
130s64 ieee754sp_tlong(ieee754sp x);
131u64 ieee754sp_tulong(ieee754sp x);
132
133int ieee754sp_cmp(ieee754sp x, ieee754sp y, int cop, int sig);
134/*
135 * basic sp math
136 */
137ieee754sp ieee754sp_modf(ieee754sp x, ieee754sp * ip);
138ieee754sp ieee754sp_frexp(ieee754sp x, int *exp);
139ieee754sp ieee754sp_ldexp(ieee754sp x, int exp);
140
141ieee754sp ieee754sp_ceil(ieee754sp x);
142ieee754sp ieee754sp_floor(ieee754sp x);
143ieee754sp ieee754sp_trunc(ieee754sp x);
144
145ieee754sp ieee754sp_sqrt(ieee754sp x);
146
147/*
148 * double precision (often aka double)
149*/
150int ieee754dp_finite(ieee754dp x);
151int ieee754dp_class(ieee754dp x);
152
153/* x with sign of y */
154ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y);
155
156ieee754dp ieee754dp_add(ieee754dp x, ieee754dp y);
157ieee754dp ieee754dp_sub(ieee754dp x, ieee754dp y);
158ieee754dp ieee754dp_mul(ieee754dp x, ieee754dp y);
159ieee754dp ieee754dp_div(ieee754dp x, ieee754dp y);
160
161ieee754dp ieee754dp_abs(ieee754dp x);
162ieee754dp ieee754dp_neg(ieee754dp x);
163ieee754dp ieee754dp_scalb(ieee754dp x, int);
164
165/* return exponent as integer in floating point format
166 */
167ieee754dp ieee754dp_logb(ieee754dp x);
168
169ieee754dp ieee754dp_fint(int x);
170ieee754dp ieee754dp_funs(unsigned x);
171ieee754dp ieee754dp_flong(s64 x);
172ieee754dp ieee754dp_fulong(u64 x);
173ieee754dp ieee754dp_fsp(ieee754sp x);
174
175ieee754dp ieee754dp_ceil(ieee754dp x);
176ieee754dp ieee754dp_floor(ieee754dp x);
177ieee754dp ieee754dp_trunc(ieee754dp x);
178
179int ieee754dp_tint(ieee754dp x);
180unsigned int ieee754dp_tuns(ieee754dp x);
181s64 ieee754dp_tlong(ieee754dp x);
182u64 ieee754dp_tulong(ieee754dp x);
183
184int ieee754dp_cmp(ieee754dp x, ieee754dp y, int cop, int sig);
185/*
186 * basic sp math
187 */
188ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip);
189ieee754dp ieee754dp_frexp(ieee754dp x, int *exp);
190ieee754dp ieee754dp_ldexp(ieee754dp x, int exp);
191
192ieee754dp ieee754dp_ceil(ieee754dp x);
193ieee754dp ieee754dp_floor(ieee754dp x);
194ieee754dp ieee754dp_trunc(ieee754dp x);
195
196ieee754dp ieee754dp_sqrt(ieee754dp x);
197
198
199
200/* 5 types of floating point number
201*/
202#define IEEE754_CLASS_NORM	0x00
203#define IEEE754_CLASS_ZERO	0x01
204#define IEEE754_CLASS_DNORM	0x02
205#define IEEE754_CLASS_INF	0x03
206#define IEEE754_CLASS_SNAN	0x04
207#define IEEE754_CLASS_QNAN	0x05
208
209/* exception numbers */
210#define IEEE754_INEXACT			0x01
211#define IEEE754_UNDERFLOW		0x02
212#define IEEE754_OVERFLOW		0x04
213#define IEEE754_ZERO_DIVIDE		0x08
214#define IEEE754_INVALID_OPERATION	0x10
215
216/* cmp operators
217*/
218#define IEEE754_CLT	0x01
219#define IEEE754_CEQ	0x02
220#define IEEE754_CGT	0x04
221#define IEEE754_CUN	0x08
222
223/* rounding mode
224*/
225#define IEEE754_RN	0	/* round to nearest */
226#define IEEE754_RZ	1	/* round toward zero  */
227#define IEEE754_RD	2	/* round toward -Infinity */
228#define IEEE754_RU	3	/* round toward +Infinity */
229
230/* other naming */
231#define IEEE754_RM	IEEE754_RD
232#define IEEE754_RP	IEEE754_RU
233
234/* "normal" comparisons
235*/
236static inline int ieee754sp_eq(ieee754sp x, ieee754sp y)
237{
238	return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
239}
240
241static inline int ieee754sp_ne(ieee754sp x, ieee754sp y)
242{
243	return ieee754sp_cmp(x, y,
244			     IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
245}
246
247static inline int ieee754sp_lt(ieee754sp x, ieee754sp y)
248{
249	return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
250}
251
252static inline int ieee754sp_le(ieee754sp x, ieee754sp y)
253{
254	return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
255}
256
257static inline int ieee754sp_gt(ieee754sp x, ieee754sp y)
258{
259	return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
260}
261
262
263static inline int ieee754sp_ge(ieee754sp x, ieee754sp y)
264{
265	return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
266}
267
268static inline int ieee754dp_eq(ieee754dp x, ieee754dp y)
269{
270	return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
271}
272
273static inline int ieee754dp_ne(ieee754dp x, ieee754dp y)
274{
275	return ieee754dp_cmp(x, y,
276			     IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
277}
278
279static inline int ieee754dp_lt(ieee754dp x, ieee754dp y)
280{
281	return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
282}
283
284static inline int ieee754dp_le(ieee754dp x, ieee754dp y)
285{
286	return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
287}
288
289static inline int ieee754dp_gt(ieee754dp x, ieee754dp y)
290{
291	return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
292}
293
294static inline int ieee754dp_ge(ieee754dp x, ieee754dp y)
295{
296	return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
297}
298
299
300/*
301 * Like strtod
302 */
303ieee754dp ieee754dp_fstr(const char *s, char **endp);
304char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af);
305
306
307/*
308 * The control status register
309 */
310struct _ieee754_csr {
311#ifdef __BIG_ENDIAN
312	unsigned pad0:7;
313	unsigned nod:1;		/* set 1 for no denormalised numbers */
314	unsigned c:1;		/* condition */
315	unsigned pad1:5;
316	unsigned cx:6;		/* exceptions this operation */
317	unsigned mx:5;		/* exception enable  mask */
318	unsigned sx:5;		/* exceptions total */
319	unsigned rm:2;		/* current rounding mode */
320#endif
321#ifdef __LITTLE_ENDIAN
322	unsigned rm:2;		/* current rounding mode */
323	unsigned sx:5;		/* exceptions total */
324	unsigned mx:5;		/* exception enable  mask */
325	unsigned cx:6;		/* exceptions this operation */
326	unsigned pad1:5;
327	unsigned c:1;		/* condition */
328	unsigned nod:1;		/* set 1 for no denormalised numbers */
329	unsigned pad0:7;
330#endif
331};
332#define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
333
334static inline unsigned ieee754_getrm(void)
335{
336	return (ieee754_csr.rm);
337}
338static inline unsigned ieee754_setrm(unsigned rm)
339{
340	return (ieee754_csr.rm = rm);
341}
342
343/*
344 * get current exceptions
345 */
346static inline unsigned ieee754_getcx(void)
347{
348	return (ieee754_csr.cx);
349}
350
351/* test for current exception condition
352 */
353static inline int ieee754_cxtest(unsigned n)
354{
355	return (ieee754_csr.cx & n);
356}
357
358/*
359 * get sticky exceptions
360 */
361static inline unsigned ieee754_getsx(void)
362{
363	return (ieee754_csr.sx);
364}
365
366/* clear sticky conditions
367*/
368static inline unsigned ieee754_clrsx(void)
369{
370	return (ieee754_csr.sx = 0);
371}
372
373/* test for sticky exception condition
374 */
375static inline int ieee754_sxtest(unsigned n)
376{
377	return (ieee754_csr.sx & n);
378}
379
380/* debugging */
381ieee754sp ieee754sp_dump(char *s, ieee754sp x);
382ieee754dp ieee754dp_dump(char *s, ieee754dp x);
383
384#define IEEE754_SPCVAL_PZERO	0
385#define IEEE754_SPCVAL_NZERO	1
386#define IEEE754_SPCVAL_PONE	2
387#define IEEE754_SPCVAL_NONE	3
388#define IEEE754_SPCVAL_PTEN	4
389#define IEEE754_SPCVAL_NTEN	5
390#define IEEE754_SPCVAL_PINFINITY	6
391#define IEEE754_SPCVAL_NINFINITY	7
392#define IEEE754_SPCVAL_INDEF	8
393#define IEEE754_SPCVAL_PMAX	9	/* +max norm */
394#define IEEE754_SPCVAL_NMAX	10	/* -max norm */
395#define IEEE754_SPCVAL_PMIN	11	/* +min norm */
396#define IEEE754_SPCVAL_NMIN	12	/* +min norm */
397#define IEEE754_SPCVAL_PMIND	13	/* +min denorm */
398#define IEEE754_SPCVAL_NMIND	14	/* +min denorm */
399#define IEEE754_SPCVAL_P1E31	15	/* + 1.0e31 */
400#define IEEE754_SPCVAL_P1E63	16	/* + 1.0e63 */
401
402extern const struct ieee754dp_konst __ieee754dp_spcvals[];
403extern const struct ieee754sp_konst __ieee754sp_spcvals[];
404#define ieee754dp_spcvals ((const ieee754dp *)__ieee754dp_spcvals)
405#define ieee754sp_spcvals ((const ieee754sp *)__ieee754sp_spcvals)
406
407/*
408 * Return infinity with given sign
409 */
410#define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
411#define ieee754dp_zero(sn)	(ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
412#define ieee754dp_one(sn)	(ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
413#define ieee754dp_ten(sn)	(ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
414#define ieee754dp_indef()	(ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
415#define ieee754dp_max(sn)	(ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
416#define ieee754dp_min(sn)	(ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
417#define ieee754dp_mind(sn)	(ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
418#define ieee754dp_1e31()	(ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
419#define ieee754dp_1e63()	(ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
420
421#define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
422#define ieee754sp_zero(sn)	(ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
423#define ieee754sp_one(sn)	(ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
424#define ieee754sp_ten(sn)	(ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
425#define ieee754sp_indef()	(ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
426#define ieee754sp_max(sn)	(ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
427#define ieee754sp_min(sn)	(ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
428#define ieee754sp_mind(sn)	(ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
429#define ieee754sp_1e31()	(ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
430#define ieee754sp_1e63()	(ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
431
432/*
433 * Indefinite integer value
434 */
435#define ieee754si_indef()	INT_MAX
436#ifdef LONG_LONG_MAX
437#define ieee754di_indef()	LONG_LONG_MAX
438#else
439#define ieee754di_indef()	((s64)(~0ULL>>1))
440#endif
441
442/* IEEE exception context, passed to handler */
443struct ieee754xctx {
444	const char *op;		/* operation name */
445	int rt;			/* result type */
446	union {
447		ieee754sp sp;	/* single precision */
448		ieee754dp dp;	/* double precision */
449#ifdef IEEE854_XP
450		ieee754xp xp;	/* extended precision */
451#endif
452		int si;		/* standard signed integer (32bits) */
453		s64 di;		/* extended signed integer (64bits) */
454	} rv;			/* default result format implied by op */
455	va_list ap;
456};
457
458/* result types for xctx.rt */
459#define IEEE754_RT_SP	0
460#define IEEE754_RT_DP	1
461#define IEEE754_RT_XP	2
462#define IEEE754_RT_SI	3
463#define IEEE754_RT_DI	4
464
465extern void ieee754_xcpt(struct ieee754xctx *xcp);
466
467/* compat */
468#define ieee754dp_fix(x)	ieee754dp_tint(x)
469#define ieee754sp_fix(x)	ieee754sp_tint(x)
470
471#endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */
472