arch/mips/math-emu/ieee754.h

   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 *)(&current->thread.fpu.fcr31))
 165
 166 static inline unsigned ieee754_getrm(void)
 167 {
 168         return (ieee754_csr.rm);
 169 }
 170 static inline unsigned ieee754_setrm(unsigned rm)
 171 {
 172         return (ieee754_csr.rm = rm);
 173 }
 174
 175 /*
 176  * get current exceptions
 177  */
 178 static inline unsigned ieee754_getcx(void)
 179 {
 180         return (ieee754_csr.cx);
 181 }
 182
 183 /* test for current exception condition
 184  */
 185 static inline int ieee754_cxtest(unsigned n)
 186 {
 187         return (ieee754_csr.cx & n);
 188 }
 189
 190 /*
 191  * get sticky exceptions
 192  */
 193 static inline unsigned ieee754_getsx(void)
 194 {
 195         return (ieee754_csr.sx);
 196 }
 197
 198 /* clear sticky conditions
 199 */
 200 static inline unsigned ieee754_clrsx(void)
 201 {
 202         return (ieee754_csr.sx = 0);
 203 }
 204
 205 /* test for sticky exception condition
 206  */
 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  */
 270 static inline int ieee754si_indef(void)
 271 {
 272         return ieee754_csr.nan2008 ? 0 : INT_MAX;
 273 }
 274
 275 static inline s64 ieee754di_indef(void)
 276 {
 277         return ieee754_csr.nan2008 ? 0 : S64_MAX;
 278 }
 279
 280 /*
 281  * Overflow integer value
 282  */
 283 static inline int ieee754si_overflow(int xs)
 284 {
 285         return ieee754_csr.nan2008 && xs ? INT_MIN : INT_MAX;
 286 }
 287
 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 */