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
34union 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
44union 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*/
57int ieee754sp_class(union ieee754sp x);
58
59union ieee754sp ieee754sp_abs(union ieee754sp x);
60union ieee754sp ieee754sp_neg(union ieee754sp x);
61
62union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y);
63union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y);
64union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y);
65union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y);
66
67union ieee754sp ieee754sp_fint(int x);
68union ieee754sp ieee754sp_flong(s64 x);
69union ieee754sp ieee754sp_fdp(union ieee754dp x);
70
71int ieee754sp_tint(union ieee754sp x);
72s64 ieee754sp_tlong(union ieee754sp x);
73
74int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
75
76union ieee754sp ieee754sp_sqrt(union ieee754sp x);
77
78/*
79 * double precision (often aka double)
80*/
81int ieee754dp_class(union ieee754dp x);
82
83union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
84union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
85union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
86union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
87
88union ieee754dp ieee754dp_abs(union ieee754dp x);
89union ieee754dp ieee754dp_neg(union ieee754dp x);
90
91union ieee754dp ieee754dp_fint(int x);
92union ieee754dp ieee754dp_flong(s64 x);
93union ieee754dp ieee754dp_fsp(union ieee754sp x);
94
95int ieee754dp_tint(union ieee754dp x);
96s64 ieee754dp_tlong(union ieee754dp x);
97
98int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
99
100union ieee754dp ieee754dp_sqrt(union ieee754dp x);
101
102
103
104/* 5 types of floating point number
105*/
106enum {
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 */
132struct _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 *)(&current->thread.fpu.fcr31))
146
147static inline unsigned ieee754_getrm(void)
148{
149	return (ieee754_csr.rm);
150}
151static inline unsigned ieee754_setrm(unsigned rm)
152{
153	return (ieee754_csr.rm = rm);
154}
155
156/*
157 * get current exceptions
158 */
159static inline unsigned ieee754_getcx(void)
160{
161	return (ieee754_csr.cx);
162}
163
164/* test for current exception condition
165 */
166static inline int ieee754_cxtest(unsigned n)
167{
168	return (ieee754_csr.cx & n);
169}
170
171/*
172 * get sticky exceptions
173 */
174static inline unsigned ieee754_getsx(void)
175{
176	return (ieee754_csr.sx);
177}
178
179/* clear sticky conditions
180*/
181static inline unsigned ieee754_clrsx(void)
182{
183	return (ieee754_csr.sx = 0);
184}
185
186/* test for sticky exception condition
187 */
188static inline int ieee754_sxtest(unsigned n)
189{
190	return (ieee754_csr.sx & n);
191}
192
193/* debugging */
194union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
195union 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
215extern const union ieee754dp __ieee754dp_spcvals[];
216extern 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 */
248static inline int ieee754si_indef(void)
249{
250	return INT_MAX;
251}
252
253static 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