MIPS: ieee754.h: Correct comments for special values
[deliverable/linux.git] / arch / mips / math-emu / ieee754.h
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1da177e4
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1/*
2 * MIPS floating point support
3 * Copyright (C) 1994-2000 Algorithmics Ltd.
1da177e4 4 *
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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.,
3f7cac41 16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1da177e4 17 *
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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.
cd21dfcf 23 */
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24#ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
25#define __ARCH_MIPS_MATH_EMU_IEEE754_H
1da177e4 26
cae55066 27#include <linux/compiler.h>
cd21dfcf 28#include <asm/byteorder.h>
e812a739 29#include <linux/kernel.h>
1da177e4 30#include <linux/types.h>
cd21dfcf 31#include <linux/sched.h>
f80cc08d 32#include <asm/bitfield.h>
1da177e4 33
2209bcb1 34union ieee754dp {
1da177e4 35 struct {
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36 __BITFIELD_FIELD(unsigned int sign:1,
37 __BITFIELD_FIELD(unsigned int bexp:11,
38 __BITFIELD_FIELD(u64 mant:52,
39 ;)))
49548b09 40 };
1da177e4 41 u64 bits;
2209bcb1 42};
1da177e4 43
2209bcb1 44union ieee754sp {
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45 struct {
46 __BITFIELD_FIELD(unsigned sign:1,
47 __BITFIELD_FIELD(unsigned bexp:8,
48 __BITFIELD_FIELD(unsigned mant:23,
49 ;)))
50 };
1da177e4 51 u32 bits;
2209bcb1 52};
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53
54/*
55 * single precision (often aka float)
56*/
2209bcb1 57int ieee754sp_class(union ieee754sp x);
1da177e4 58
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59union ieee754sp ieee754sp_abs(union ieee754sp x);
60union ieee754sp ieee754sp_neg(union ieee754sp x);
1da177e4 61
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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);
1da177e4 66
2209bcb1 67union ieee754sp ieee754sp_fint(int x);
2209bcb1 68union ieee754sp ieee754sp_flong(s64 x);
2209bcb1 69union ieee754sp ieee754sp_fdp(union ieee754dp x);
1da177e4 70
2209bcb1 71int ieee754sp_tint(union ieee754sp x);
2209bcb1 72s64 ieee754sp_tlong(union ieee754sp x);
1da177e4 73
2209bcb1 74int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
1da177e4 75
2209bcb1 76union ieee754sp ieee754sp_sqrt(union ieee754sp x);
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77
78/*
79 * double precision (often aka double)
80*/
2209bcb1 81int ieee754dp_class(union ieee754dp x);
1da177e4 82
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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);
1da177e4 87
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88union ieee754dp ieee754dp_abs(union ieee754dp x);
89union ieee754dp ieee754dp_neg(union ieee754dp x);
1da177e4 90
2209bcb1 91union ieee754dp ieee754dp_fint(int x);
2209bcb1 92union ieee754dp ieee754dp_flong(s64 x);
2209bcb1 93union ieee754dp ieee754dp_fsp(union ieee754sp x);
1da177e4 94
2209bcb1 95int ieee754dp_tint(union ieee754dp x);
2209bcb1 96s64 ieee754dp_tlong(union ieee754dp x);
1da177e4 97
2209bcb1 98int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
1da177e4 99
2209bcb1 100union ieee754dp ieee754dp_sqrt(union ieee754dp x);
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101
102
103
104/* 5 types of floating point number
105*/
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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};
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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
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129/* "normal" comparisons
130*/
2209bcb1 131static inline int ieee754sp_eq(union ieee754sp x, union ieee754sp y)
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132{
133 return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
134}
135
2209bcb1 136static inline int ieee754sp_ne(union ieee754sp x, union ieee754sp y)
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137{
138 return ieee754sp_cmp(x, y,
139 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
140}
141
2209bcb1 142static inline int ieee754sp_lt(union ieee754sp x, union ieee754sp y)
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143{
144 return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
145}
146
2209bcb1 147static inline int ieee754sp_le(union ieee754sp x, union ieee754sp y)
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148{
149 return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
150}
151
2209bcb1 152static inline int ieee754sp_gt(union ieee754sp x, union ieee754sp y)
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153{
154 return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
155}
156
157
2209bcb1 158static inline int ieee754sp_ge(union ieee754sp x, union ieee754sp y)
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159{
160 return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
161}
162
2209bcb1 163static inline int ieee754dp_eq(union ieee754dp x, union ieee754dp y)
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164{
165 return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
166}
167
2209bcb1 168static inline int ieee754dp_ne(union ieee754dp x, union ieee754dp y)
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169{
170 return ieee754dp_cmp(x, y,
171 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
172}
173
2209bcb1 174static inline int ieee754dp_lt(union ieee754dp x, union ieee754dp y)
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175{
176 return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
177}
178
2209bcb1 179static inline int ieee754dp_le(union ieee754dp x, union ieee754dp y)
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180{
181 return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
182}
183
2209bcb1 184static inline int ieee754dp_gt(union ieee754dp x, union ieee754dp y)
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185{
186 return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
187}
188
2209bcb1 189static inline int ieee754dp_ge(union ieee754dp x, union ieee754dp y)
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190{
191 return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
192}
193
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194/*
195 * The control status register
196 */
197struct _ieee754_csr {
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198 __BITFIELD_FIELD(unsigned pad0:7,
199 __BITFIELD_FIELD(unsigned nod:1, /* set 1 for no denormalised numbers */
200 __BITFIELD_FIELD(unsigned c:1, /* condition */
201 __BITFIELD_FIELD(unsigned pad1:5,
202 __BITFIELD_FIELD(unsigned cx:6, /* exceptions this operation */
203 __BITFIELD_FIELD(unsigned mx:5, /* exception enable mask */
204 __BITFIELD_FIELD(unsigned sx:5, /* exceptions total */
205 __BITFIELD_FIELD(unsigned rm:2, /* current rounding mode */
206 ;))))))))
1da177e4 207};
eae89076 208#define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
1da177e4 209
cd21dfcf 210static inline unsigned ieee754_getrm(void)
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211{
212 return (ieee754_csr.rm);
213}
cd21dfcf 214static inline unsigned ieee754_setrm(unsigned rm)
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215{
216 return (ieee754_csr.rm = rm);
217}
218
219/*
220 * get current exceptions
221 */
cd21dfcf 222static inline unsigned ieee754_getcx(void)
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223{
224 return (ieee754_csr.cx);
225}
226
227/* test for current exception condition
228 */
cd21dfcf 229static inline int ieee754_cxtest(unsigned n)
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230{
231 return (ieee754_csr.cx & n);
232}
233
234/*
235 * get sticky exceptions
236 */
cd21dfcf 237static inline unsigned ieee754_getsx(void)
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238{
239 return (ieee754_csr.sx);
240}
241
242/* clear sticky conditions
243*/
cd21dfcf 244static inline unsigned ieee754_clrsx(void)
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245{
246 return (ieee754_csr.sx = 0);
247}
248
249/* test for sticky exception condition
250 */
cd21dfcf 251static inline int ieee754_sxtest(unsigned n)
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252{
253 return (ieee754_csr.sx & n);
254}
255
256/* debugging */
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257union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
258union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
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259
260#define IEEE754_SPCVAL_PZERO 0
261#define IEEE754_SPCVAL_NZERO 1
262#define IEEE754_SPCVAL_PONE 2
263#define IEEE754_SPCVAL_NONE 3
264#define IEEE754_SPCVAL_PTEN 4
265#define IEEE754_SPCVAL_NTEN 5
266#define IEEE754_SPCVAL_PINFINITY 6
267#define IEEE754_SPCVAL_NINFINITY 7
268#define IEEE754_SPCVAL_INDEF 8
269#define IEEE754_SPCVAL_PMAX 9 /* +max norm */
270#define IEEE754_SPCVAL_NMAX 10 /* -max norm */
271#define IEEE754_SPCVAL_PMIN 11 /* +min norm */
b3fea962 272#define IEEE754_SPCVAL_NMIN 12 /* -min norm */
1da177e4 273#define IEEE754_SPCVAL_PMIND 13 /* +min denorm */
b3fea962 274#define IEEE754_SPCVAL_NMIND 14 /* -min denorm */
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275#define IEEE754_SPCVAL_P1E31 15 /* + 1.0e31 */
276#define IEEE754_SPCVAL_P1E63 16 /* + 1.0e63 */
277
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278extern const union ieee754dp __ieee754dp_spcvals[];
279extern const union ieee754sp __ieee754sp_spcvals[];
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280#define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
281#define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
1da177e4 282
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283/*
284 * Return infinity with given sign
285 */
286#define ieee754dp_inf(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
287#define ieee754dp_zero(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
288#define ieee754dp_one(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
289#define ieee754dp_ten(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
290#define ieee754dp_indef() (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
291#define ieee754dp_max(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
292#define ieee754dp_min(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
293#define ieee754dp_mind(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
294#define ieee754dp_1e31() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
295#define ieee754dp_1e63() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
296
297#define ieee754sp_inf(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
298#define ieee754sp_zero(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
299#define ieee754sp_one(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
300#define ieee754sp_ten(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
301#define ieee754sp_indef() (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
302#define ieee754sp_max(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
303#define ieee754sp_min(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
304#define ieee754sp_mind(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
305#define ieee754sp_1e31() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
306#define ieee754sp_1e63() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
307
308/*
309 * Indefinite integer value
310 */
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311static inline int ieee754si_indef(void)
312{
313 return INT_MAX;
314}
315
316static inline s64 ieee754di_indef(void)
317{
318 return S64_MAX;
319}
1da177e4 320
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321/* result types for xctx.rt */
322#define IEEE754_RT_SP 0
323#define IEEE754_RT_DP 1
324#define IEEE754_RT_XP 2
325#define IEEE754_RT_SI 3
326#define IEEE754_RT_DI 4
327
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328/* compat */
329#define ieee754dp_fix(x) ieee754dp_tint(x)
330#define ieee754sp_fix(x) ieee754sp_tint(x)
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331
332#endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */
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