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 /*
  79  * double precision (often aka double)
  80 */
  81 int ieee754dp_class(union ieee754dp x);
  82
  83 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
  84 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
  85 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
  86 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
  87
  88 union ieee754dp ieee754dp_abs(union ieee754dp x);
  89 union ieee754dp ieee754dp_neg(union ieee754dp x);
  90
  91 union ieee754dp ieee754dp_fint(int x);
  92 union ieee754dp ieee754dp_flong(s64 x);
  93 union ieee754dp ieee754dp_fsp(union ieee754sp x);
  94
  95 int ieee754dp_tint(union ieee754dp x);
  96 s64 ieee754dp_tlong(union ieee754dp x);
  97
  98 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
  99
 100 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
 101
 102
 103
 104 /* 5 types of floating point number
 105 */
 106 enum {
 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  */
 132 struct _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
 147 static inline unsigned ieee754_getrm(void)
 148 {
 149         return (ieee754_csr.rm);
 150 }
 151 static inline unsigned ieee754_setrm(unsigned rm)
 152 {
 153         return (ieee754_csr.rm = rm);
 154 }
 155
 156 /*
 157  * get current exceptions
 158  */
 159 static inline unsigned ieee754_getcx(void)
 160 {
 161         return (ieee754_csr.cx);
 162 }
 163
 164 /* test for current exception condition
 165  */
 166 static inline int ieee754_cxtest(unsigned n)
 167 {
 168         return (ieee754_csr.cx & n);
 169 }
 170
 171 /*
 172  * get sticky exceptions
 173  */
 174 static inline unsigned ieee754_getsx(void)
 175 {
 176         return (ieee754_csr.sx);
 177 }
 178
 179 /* clear sticky conditions
 180 */
 181 static inline unsigned ieee754_clrsx(void)
 182 {
 183         return (ieee754_csr.sx = 0);
 184 }
 185
 186 /* test for sticky exception condition
 187  */
 188 static inline int ieee754_sxtest(unsigned n)
 189 {
 190         return (ieee754_csr.sx & n);
 191 }
 192
 193 /* debugging */
 194 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
 195 union 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
 215 extern const union ieee754dp __ieee754dp_spcvals[];
 216 extern 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  */
 248 static inline int ieee754si_indef(void)
 249 {
 250         return INT_MAX;
 251 }
 252
 253 static 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 */