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 union ieee754sp ieee754sp_rint(union ieee754sp x);
  71
  72 int ieee754sp_tint(union ieee754sp x);
  73 s64 ieee754sp_tlong(union ieee754sp x);
  74
  75 int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
  76
  77 union ieee754sp ieee754sp_sqrt(union ieee754sp x);
  78
  79 union ieee754sp ieee754sp_maddf(union ieee754sp z, union ieee754sp x,
  80                                 union ieee754sp y);
  81 union ieee754sp ieee754sp_msubf(union ieee754sp z, union ieee754sp x,
  82                                 union ieee754sp y);
  83 int ieee754sp_2008class(union ieee754sp x);
  84 union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y);
  85 union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y);
  86 union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y);
  87 union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y);
  88
  89 /*
  90  * double precision (often aka double)
  91 */
  92 int ieee754dp_class(union ieee754dp x);
  93
  94 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
  95 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
  96 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
  97 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
  98
  99 union ieee754dp ieee754dp_abs(union ieee754dp x);
 100 union ieee754dp ieee754dp_neg(union ieee754dp x);
 101
 102 union ieee754dp ieee754dp_fint(int x);
 103 union ieee754dp ieee754dp_flong(s64 x);
 104 union ieee754dp ieee754dp_fsp(union ieee754sp x);
 105 union ieee754dp ieee754dp_rint(union ieee754dp x);
 106
 107 int ieee754dp_tint(union ieee754dp x);
 108 s64 ieee754dp_tlong(union ieee754dp x);
 109
 110 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
 111
 112 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
 113
 114 union ieee754dp ieee754dp_maddf(union ieee754dp z, union ieee754dp x,
 115                                 union ieee754dp y);
 116 union ieee754dp ieee754dp_msubf(union ieee754dp z, union ieee754dp x,
 117                                 union ieee754dp y);
 118 int ieee754dp_2008class(union ieee754dp x);
 119 union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y);
 120 union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y);
 121 union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y);
 122 union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y);
 123
 124
 125 /* 5 types of floating point number
 126 */
 127 enum {
 128         IEEE754_CLASS_NORM      = 0x00,
 129         IEEE754_CLASS_ZERO      = 0x01,
 130         IEEE754_CLASS_DNORM     = 0x02,
 131         IEEE754_CLASS_INF       = 0x03,
 132         IEEE754_CLASS_SNAN      = 0x04,
 133         IEEE754_CLASS_QNAN      = 0x05,
 134 };
 135
 136 /* exception numbers */
 137 #define IEEE754_INEXACT                 0x01
 138 #define IEEE754_UNDERFLOW               0x02
 139 #define IEEE754_OVERFLOW                0x04
 140 #define IEEE754_ZERO_DIVIDE             0x08
 141 #define IEEE754_INVALID_OPERATION       0x10
 142
 143 /* cmp operators
 144 */
 145 #define IEEE754_CLT     0x01
 146 #define IEEE754_CEQ     0x02
 147 #define IEEE754_CGT     0x04
 148 #define IEEE754_CUN     0x08
 149
 150 /*
 151  * The control status register
 152  */
 153 struct _ieee754_csr {
 154         __BITFIELD_FIELD(unsigned fcc:7,        /* condition[7:1] */
 155         __BITFIELD_FIELD(unsigned nod:1,        /* set 1 for no denormals */
 156         __BITFIELD_FIELD(unsigned c:1,          /* condition[0] */
 157         __BITFIELD_FIELD(unsigned pad0:3,
 158         __BITFIELD_FIELD(unsigned abs2008:1,    /* IEEE 754-2008 ABS/NEG.fmt */
 159         __BITFIELD_FIELD(unsigned nan2008:1,    /* IEEE 754-2008 NaN mode */
 160         __BITFIELD_FIELD(unsigned cx:6,         /* exceptions this operation */
 161         __BITFIELD_FIELD(unsigned mx:5,         /* exception enable  mask */
 162         __BITFIELD_FIELD(unsigned sx:5,         /* exceptions total */
 163         __BITFIELD_FIELD(unsigned rm:2,         /* current rounding mode */
 164         ;))))))))))
 165 };
 166 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
 167
 168 static inline unsigned int ieee754_getrm(void)
 169 {
 170         return (ieee754_csr.rm);
 171 }
 172
 173 static inline unsigned int ieee754_setrm(unsigned int rm)
 174 {
 175         return (ieee754_csr.rm = rm);
 176 }
 177
 178 /*
 179  * get current exceptions
 180  */
 181 static inline unsigned int ieee754_getcx(void)
 182 {
 183         return (ieee754_csr.cx);
 184 }
 185
 186 /* test for current exception condition
 187  */
 188 static inline int ieee754_cxtest(unsigned int n)
 189 {
 190         return (ieee754_csr.cx & n);
 191 }
 192
 193 /*
 194  * get sticky exceptions
 195  */
 196 static inline unsigned int ieee754_getsx(void)
 197 {
 198         return (ieee754_csr.sx);
 199 }
 200
 201 /* clear sticky conditions
 202 */
 203 static inline unsigned int ieee754_clrsx(void)
 204 {
 205         return (ieee754_csr.sx = 0);
 206 }
 207
 208 /* test for sticky exception condition
 209  */
 210 static inline int ieee754_sxtest(unsigned int n)
 211 {
 212         return (ieee754_csr.sx & n);
 213 }
 214
 215 /* debugging */
 216 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
 217 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
 218
 219 #define IEEE754_SPCVAL_PZERO            0       /* +0.0 */
 220 #define IEEE754_SPCVAL_NZERO            1       /* -0.0 */
 221 #define IEEE754_SPCVAL_PONE             2       /* +1.0 */
 222 #define IEEE754_SPCVAL_NONE             3       /* -1.0 */
 223 #define IEEE754_SPCVAL_PTEN             4       /* +10.0 */
 224 #define IEEE754_SPCVAL_NTEN             5       /* -10.0 */
 225 #define IEEE754_SPCVAL_PINFINITY        6       /* +inf */
 226 #define IEEE754_SPCVAL_NINFINITY        7       /* -inf */
 227 #define IEEE754_SPCVAL_INDEF_LEG        8       /* legacy quiet NaN */
 228 #define IEEE754_SPCVAL_INDEF_2008       9       /* IEEE 754-2008 quiet NaN */
 229 #define IEEE754_SPCVAL_PMAX             10      /* +max norm */
 230 #define IEEE754_SPCVAL_NMAX             11      /* -max norm */
 231 #define IEEE754_SPCVAL_PMIN             12      /* +min norm */
 232 #define IEEE754_SPCVAL_NMIN             13      /* -min norm */
 233 #define IEEE754_SPCVAL_PMIND            14      /* +min denorm */
 234 #define IEEE754_SPCVAL_NMIND            15      /* -min denorm */
 235 #define IEEE754_SPCVAL_P1E31            16      /* + 1.0e31 */
 236 #define IEEE754_SPCVAL_P1E63            17      /* + 1.0e63 */
 237
 238 extern const union ieee754dp __ieee754dp_spcvals[];
 239 extern const union ieee754sp __ieee754sp_spcvals[];
 240 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
 241 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
 242
 243 /*
 244  * Return infinity with given sign
 245  */
 246 #define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 247 #define ieee754dp_zero(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 248 #define ieee754dp_one(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 249 #define ieee754dp_ten(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 250 #define ieee754dp_indef()       (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
 251                                                    ieee754_csr.nan2008])
 252 #define ieee754dp_max(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 253 #define ieee754dp_min(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 254 #define ieee754dp_mind(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 255 #define ieee754dp_1e31()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
 256 #define ieee754dp_1e63()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
 257
 258 #define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 259 #define ieee754sp_zero(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 260 #define ieee754sp_one(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 261 #define ieee754sp_ten(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 262 #define ieee754sp_indef()       (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
 263                                                    ieee754_csr.nan2008])
 264 #define ieee754sp_max(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 265 #define ieee754sp_min(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 266 #define ieee754sp_mind(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 267 #define ieee754sp_1e31()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
 268 #define ieee754sp_1e63()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
 269
 270 /*
 271  * Indefinite integer value
 272  */
 273 static inline int ieee754si_indef(void)
 274 {
 275         return ieee754_csr.nan2008 ? 0 : INT_MAX;
 276 }
 277
 278 static inline s64 ieee754di_indef(void)
 279 {
 280         return ieee754_csr.nan2008 ? 0 : S64_MAX;
 281 }
 282
 283 /*
 284  * Overflow integer value
 285  */
 286 static inline int ieee754si_overflow(int xs)
 287 {
 288         return ieee754_csr.nan2008 && xs ? INT_MIN : INT_MAX;
 289 }
 290
 291 static inline s64 ieee754di_overflow(int xs)
 292 {
 293         return ieee754_csr.nan2008 && xs ? S64_MIN : S64_MAX;
 294 }
 295
 296 /* result types for xctx.rt */
 297 #define IEEE754_RT_SP   0
 298 #define IEEE754_RT_DP   1
 299 #define IEEE754_RT_XP   2
 300 #define IEEE754_RT_SI   3
 301 #define IEEE754_RT_DI   4
 302
 303 /* compat */
 304 #define ieee754dp_fix(x)        ieee754dp_tint(x)
 305 #define ieee754sp_fix(x)        ieee754sp_tint(x)
 306
 307 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */