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
  81 /*
  82  * double precision (often aka double)
  83 */
  84 int ieee754dp_class(union ieee754dp x);
  85
  86 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
  87 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
  88 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
  89 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
  90
  91 union ieee754dp ieee754dp_abs(union ieee754dp x);
  92 union ieee754dp ieee754dp_neg(union ieee754dp x);
  93
  94 union ieee754dp ieee754dp_fint(int x);
  95 union ieee754dp ieee754dp_flong(s64 x);
  96 union ieee754dp ieee754dp_fsp(union ieee754sp x);
  97
  98 int ieee754dp_tint(union ieee754dp x);
  99 s64 ieee754dp_tlong(union ieee754dp x);
 100
 101 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
 102
 103 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
 104
 105 union ieee754dp ieee754dp_maddf(union ieee754dp z, union ieee754dp x,
 106                                 union ieee754dp y);
 107
 108
 109 /* 5 types of floating point number
 110 */
 111 enum {
 112         IEEE754_CLASS_NORM      = 0x00,
 113         IEEE754_CLASS_ZERO      = 0x01,
 114         IEEE754_CLASS_DNORM     = 0x02,
 115         IEEE754_CLASS_INF       = 0x03,
 116         IEEE754_CLASS_SNAN      = 0x04,
 117         IEEE754_CLASS_QNAN      = 0x05,
 118 };
 119
 120 /* exception numbers */
 121 #define IEEE754_INEXACT                 0x01
 122 #define IEEE754_UNDERFLOW               0x02
 123 #define IEEE754_OVERFLOW                0x04
 124 #define IEEE754_ZERO_DIVIDE             0x08
 125 #define IEEE754_INVALID_OPERATION       0x10
 126
 127 /* cmp operators
 128 */
 129 #define IEEE754_CLT     0x01
 130 #define IEEE754_CEQ     0x02
 131 #define IEEE754_CGT     0x04
 132 #define IEEE754_CUN     0x08
 133
 134 /*
 135  * The control status register
 136  */
 137 struct _ieee754_csr {
 138         __BITFIELD_FIELD(unsigned fcc:7,        /* condition[7:1] */
 139         __BITFIELD_FIELD(unsigned nod:1,        /* set 1 for no denormals */
 140         __BITFIELD_FIELD(unsigned c:1,          /* condition[0] */
 141         __BITFIELD_FIELD(unsigned pad0:3,
 142         __BITFIELD_FIELD(unsigned abs2008:1,    /* IEEE 754-2008 ABS/NEG.fmt */
 143         __BITFIELD_FIELD(unsigned nan2008:1,    /* IEEE 754-2008 NaN mode */
 144         __BITFIELD_FIELD(unsigned cx:6,         /* exceptions this operation */
 145         __BITFIELD_FIELD(unsigned mx:5,         /* exception enable  mask */
 146         __BITFIELD_FIELD(unsigned sx:5,         /* exceptions total */
 147         __BITFIELD_FIELD(unsigned rm:2,         /* current rounding mode */
 148         ;))))))))))
 149 };
 150 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
 151
 152 static inline unsigned ieee754_getrm(void)
 153 {
 154         return (ieee754_csr.rm);
 155 }
 156 static inline unsigned ieee754_setrm(unsigned rm)
 157 {
 158         return (ieee754_csr.rm = rm);
 159 }
 160
 161 /*
 162  * get current exceptions
 163  */
 164 static inline unsigned ieee754_getcx(void)
 165 {
 166         return (ieee754_csr.cx);
 167 }
 168
 169 /* test for current exception condition
 170  */
 171 static inline int ieee754_cxtest(unsigned n)
 172 {
 173         return (ieee754_csr.cx & n);
 174 }
 175
 176 /*
 177  * get sticky exceptions
 178  */
 179 static inline unsigned ieee754_getsx(void)
 180 {
 181         return (ieee754_csr.sx);
 182 }
 183
 184 /* clear sticky conditions
 185 */
 186 static inline unsigned ieee754_clrsx(void)
 187 {
 188         return (ieee754_csr.sx = 0);
 189 }
 190
 191 /* test for sticky exception condition
 192  */
 193 static inline int ieee754_sxtest(unsigned n)
 194 {
 195         return (ieee754_csr.sx & n);
 196 }
 197
 198 /* debugging */
 199 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
 200 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
 201
 202 #define IEEE754_SPCVAL_PZERO            0       /* +0.0 */
 203 #define IEEE754_SPCVAL_NZERO            1       /* -0.0 */
 204 #define IEEE754_SPCVAL_PONE             2       /* +1.0 */
 205 #define IEEE754_SPCVAL_NONE             3       /* -1.0 */
 206 #define IEEE754_SPCVAL_PTEN             4       /* +10.0 */
 207 #define IEEE754_SPCVAL_NTEN             5       /* -10.0 */
 208 #define IEEE754_SPCVAL_PINFINITY        6       /* +inf */
 209 #define IEEE754_SPCVAL_NINFINITY        7       /* -inf */
 210 #define IEEE754_SPCVAL_INDEF            8       /* quiet NaN */
 211 #define IEEE754_SPCVAL_PMAX             9       /* +max norm */
 212 #define IEEE754_SPCVAL_NMAX             10      /* -max norm */
 213 #define IEEE754_SPCVAL_PMIN             11      /* +min norm */
 214 #define IEEE754_SPCVAL_NMIN             12      /* -min norm */
 215 #define IEEE754_SPCVAL_PMIND            13      /* +min denorm */
 216 #define IEEE754_SPCVAL_NMIND            14      /* -min denorm */
 217 #define IEEE754_SPCVAL_P1E31            15      /* + 1.0e31 */
 218 #define IEEE754_SPCVAL_P1E63            16      /* + 1.0e63 */
 219
 220 extern const union ieee754dp __ieee754dp_spcvals[];
 221 extern const union ieee754sp __ieee754sp_spcvals[];
 222 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
 223 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
 224
 225 /*
 226  * Return infinity with given sign
 227  */
 228 #define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 229 #define ieee754dp_zero(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 230 #define ieee754dp_one(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 231 #define ieee754dp_ten(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 232 #define ieee754dp_indef()       (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
 233 #define ieee754dp_max(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 234 #define ieee754dp_min(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 235 #define ieee754dp_mind(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 236 #define ieee754dp_1e31()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
 237 #define ieee754dp_1e63()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
 238
 239 #define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 240 #define ieee754sp_zero(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 241 #define ieee754sp_one(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 242 #define ieee754sp_ten(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 243 #define ieee754sp_indef()       (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
 244 #define ieee754sp_max(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 245 #define ieee754sp_min(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 246 #define ieee754sp_mind(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 247 #define ieee754sp_1e31()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
 248 #define ieee754sp_1e63()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
 249
 250 /*
 251  * Indefinite integer value
 252  */
 253 static inline int ieee754si_indef(void)
 254 {
 255         return INT_MAX;
 256 }
 257
 258 static inline s64 ieee754di_indef(void)
 259 {
 260         return S64_MAX;
 261 }
 262
 263 /* result types for xctx.rt */
 264 #define IEEE754_RT_SP   0
 265 #define IEEE754_RT_DP   1
 266 #define IEEE754_RT_XP   2
 267 #define IEEE754_RT_SI   3
 268 #define IEEE754_RT_DI   4
 269
 270 /* compat */
 271 #define ieee754dp_fix(x)        ieee754dp_tint(x)
 272 #define ieee754sp_fix(x)        ieee754sp_tint(x)
 273
 274 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */