arch/mips/math-emu/ieee754.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * MIPS floating point support
   4  * Copyright (C) 1994-2000 Algorithmics Ltd.
   5  *
   6  *  Nov 7, 2000
   7  *  Modification to allow integration with Linux kernel
   8  *
   9  *  Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
  10  *  Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
  11  */
  12 #ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
  13 #define __ARCH_MIPS_MATH_EMU_IEEE754_H
  14
  15 #include <linux/compiler.h>
  16 #include <asm/byteorder.h>
  17 #include <linux/kernel.h>
  18 #include <linux/types.h>
  19 #include <linux/sched.h>
  20 #include <asm/bitfield.h>
  21
  22 union ieee754dp {
  23         struct {
  24                 __BITFIELD_FIELD(unsigned int sign:1,
  25                 __BITFIELD_FIELD(unsigned int bexp:11,
  26                 __BITFIELD_FIELD(u64 mant:52,
  27                 ;)))
  28         };
  29         u64 bits;
  30 };
  31
  32 union ieee754sp {
  33         struct {
  34                 __BITFIELD_FIELD(unsigned sign:1,
  35                 __BITFIELD_FIELD(unsigned bexp:8,
  36                 __BITFIELD_FIELD(unsigned mant:23,
  37                 ;)))
  38         };
  39         u32 bits;
  40 };
  41
  42 /*
  43  * single precision (often aka float)
  44 */
  45 int ieee754sp_class(union ieee754sp x);
  46
  47 union ieee754sp ieee754sp_abs(union ieee754sp x);
  48 union ieee754sp ieee754sp_neg(union ieee754sp x);
  49
  50 union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y);
  51 union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y);
  52 union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y);
  53 union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y);
  54
  55 union ieee754sp ieee754sp_fint(int x);
  56 union ieee754sp ieee754sp_flong(s64 x);
  57 union ieee754sp ieee754sp_fdp(union ieee754dp x);
  58 union ieee754sp ieee754sp_rint(union ieee754sp x);
  59
  60 int ieee754sp_tint(union ieee754sp x);
  61 s64 ieee754sp_tlong(union ieee754sp x);
  62
  63 int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
  64
  65 union ieee754sp ieee754sp_sqrt(union ieee754sp x);
  66
  67 union ieee754sp ieee754sp_maddf(union ieee754sp z, union ieee754sp x,
  68                                 union ieee754sp y);
  69 union ieee754sp ieee754sp_msubf(union ieee754sp z, union ieee754sp x,
  70                                 union ieee754sp y);
  71 union ieee754sp ieee754sp_madd(union ieee754sp z, union ieee754sp x,
  72                                 union ieee754sp y);
  73 union ieee754sp ieee754sp_msub(union ieee754sp z, union ieee754sp x,
  74                                 union ieee754sp y);
  75 union ieee754sp ieee754sp_nmadd(union ieee754sp z, union ieee754sp x,
  76                                 union ieee754sp y);
  77 union ieee754sp ieee754sp_nmsub(union ieee754sp z, union ieee754sp x,
  78                                 union ieee754sp y);
  79 int ieee754sp_2008class(union ieee754sp x);
  80 union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y);
  81 union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y);
  82 union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y);
  83 union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y);
  84
  85 /*
  86  * double precision (often aka double)
  87 */
  88 int ieee754dp_class(union ieee754dp x);
  89
  90 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
  91 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
  92 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
  93 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
  94
  95 union ieee754dp ieee754dp_abs(union ieee754dp x);
  96 union ieee754dp ieee754dp_neg(union ieee754dp x);
  97
  98 union ieee754dp ieee754dp_fint(int x);
  99 union ieee754dp ieee754dp_flong(s64 x);
 100 union ieee754dp ieee754dp_fsp(union ieee754sp x);
 101 union ieee754dp ieee754dp_rint(union ieee754dp x);
 102
 103 int ieee754dp_tint(union ieee754dp x);
 104 s64 ieee754dp_tlong(union ieee754dp x);
 105
 106 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
 107
 108 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
 109
 110 union ieee754dp ieee754dp_maddf(union ieee754dp z, union ieee754dp x,
 111                                 union ieee754dp y);
 112 union ieee754dp ieee754dp_msubf(union ieee754dp z, union ieee754dp x,
 113                                 union ieee754dp y);
 114 union ieee754dp ieee754dp_madd(union ieee754dp z, union ieee754dp x,
 115                                 union ieee754dp y);
 116 union ieee754dp ieee754dp_msub(union ieee754dp z, union ieee754dp x,
 117                                 union ieee754dp y);
 118 union ieee754dp ieee754dp_nmadd(union ieee754dp z, union ieee754dp x,
 119                                 union ieee754dp y);
 120 union ieee754dp ieee754dp_nmsub(union ieee754dp z, union ieee754dp x,
 121                                 union ieee754dp y);
 122 int ieee754dp_2008class(union ieee754dp x);
 123 union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y);
 124 union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y);
 125 union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y);
 126 union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y);
 127
 128
 129 /* 5 types of floating point number
 130 */
 131 enum {
 132         IEEE754_CLASS_NORM      = 0x00,
 133         IEEE754_CLASS_ZERO      = 0x01,
 134         IEEE754_CLASS_DNORM     = 0x02,
 135         IEEE754_CLASS_INF       = 0x03,
 136         IEEE754_CLASS_SNAN      = 0x04,
 137         IEEE754_CLASS_QNAN      = 0x05,
 138 };
 139
 140 /* exception numbers */
 141 #define IEEE754_INEXACT                 0x01
 142 #define IEEE754_UNDERFLOW               0x02
 143 #define IEEE754_OVERFLOW                0x04
 144 #define IEEE754_ZERO_DIVIDE             0x08
 145 #define IEEE754_INVALID_OPERATION       0x10
 146
 147 /* cmp operators
 148 */
 149 #define IEEE754_CLT     0x01
 150 #define IEEE754_CEQ     0x02
 151 #define IEEE754_CGT     0x04
 152 #define IEEE754_CUN     0x08
 153
 154 /*
 155  * The control status register
 156  */
 157 struct _ieee754_csr {
 158         __BITFIELD_FIELD(unsigned fcc:7,        /* condition[7:1] */
 159         __BITFIELD_FIELD(unsigned nod:1,        /* set 1 for no denormals */
 160         __BITFIELD_FIELD(unsigned c:1,          /* condition[0] */
 161         __BITFIELD_FIELD(unsigned pad0:3,
 162         __BITFIELD_FIELD(unsigned abs2008:1,    /* IEEE 754-2008 ABS/NEG.fmt */
 163         __BITFIELD_FIELD(unsigned nan2008:1,    /* IEEE 754-2008 NaN mode */
 164         __BITFIELD_FIELD(unsigned cx:6,         /* exceptions this operation */
 165         __BITFIELD_FIELD(unsigned mx:5,         /* exception enable  mask */
 166         __BITFIELD_FIELD(unsigned sx:5,         /* exceptions total */
 167         __BITFIELD_FIELD(unsigned rm:2,         /* current rounding mode */
 168         ;))))))))))
 169 };
 170 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
 171
 172 static inline unsigned int ieee754_getrm(void)
 173 {
 174         return (ieee754_csr.rm);
 175 }
 176
 177 static inline unsigned int ieee754_setrm(unsigned int rm)
 178 {
 179         return (ieee754_csr.rm = rm);
 180 }
 181
 182 /*
 183  * get current exceptions
 184  */
 185 static inline unsigned int ieee754_getcx(void)
 186 {
 187         return (ieee754_csr.cx);
 188 }
 189
 190 /* test for current exception condition
 191  */
 192 static inline int ieee754_cxtest(unsigned int n)
 193 {
 194         return (ieee754_csr.cx & n);
 195 }
 196
 197 /*
 198  * get sticky exceptions
 199  */
 200 static inline unsigned int ieee754_getsx(void)
 201 {
 202         return (ieee754_csr.sx);
 203 }
 204
 205 /* clear sticky conditions
 206 */
 207 static inline unsigned int ieee754_clrsx(void)
 208 {
 209         return (ieee754_csr.sx = 0);
 210 }
 211
 212 /* test for sticky exception condition
 213  */
 214 static inline int ieee754_sxtest(unsigned int n)
 215 {
 216         return (ieee754_csr.sx & n);
 217 }
 218
 219 /* debugging */
 220 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
 221 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
 222
 223 #define IEEE754_SPCVAL_PZERO            0       /* +0.0 */
 224 #define IEEE754_SPCVAL_NZERO            1       /* -0.0 */
 225 #define IEEE754_SPCVAL_PONE             2       /* +1.0 */
 226 #define IEEE754_SPCVAL_NONE             3       /* -1.0 */
 227 #define IEEE754_SPCVAL_PTEN             4       /* +10.0 */
 228 #define IEEE754_SPCVAL_NTEN             5       /* -10.0 */
 229 #define IEEE754_SPCVAL_PINFINITY        6       /* +inf */
 230 #define IEEE754_SPCVAL_NINFINITY        7       /* -inf */
 231 #define IEEE754_SPCVAL_INDEF_LEG        8       /* legacy quiet NaN */
 232 #define IEEE754_SPCVAL_INDEF_2008       9       /* IEEE 754-2008 quiet NaN */
 233 #define IEEE754_SPCVAL_PMAX             10      /* +max norm */
 234 #define IEEE754_SPCVAL_NMAX             11      /* -max norm */
 235 #define IEEE754_SPCVAL_PMIN             12      /* +min norm */
 236 #define IEEE754_SPCVAL_NMIN             13      /* -min norm */
 237 #define IEEE754_SPCVAL_PMIND            14      /* +min denorm */
 238 #define IEEE754_SPCVAL_NMIND            15      /* -min denorm */
 239 #define IEEE754_SPCVAL_P1E31            16      /* + 1.0e31 */
 240 #define IEEE754_SPCVAL_P1E63            17      /* + 1.0e63 */
 241
 242 extern const union ieee754dp __ieee754dp_spcvals[];
 243 extern const union ieee754sp __ieee754sp_spcvals[];
 244 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
 245 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
 246
 247 /*
 248  * Return infinity with given sign
 249  */
 250 #define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 251 #define ieee754dp_zero(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 252 #define ieee754dp_one(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 253 #define ieee754dp_ten(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 254 #define ieee754dp_indef()       (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
 255                                                    ieee754_csr.nan2008])
 256 #define ieee754dp_max(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 257 #define ieee754dp_min(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 258 #define ieee754dp_mind(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 259 #define ieee754dp_1e31()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
 260 #define ieee754dp_1e63()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
 261
 262 #define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 263 #define ieee754sp_zero(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 264 #define ieee754sp_one(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 265 #define ieee754sp_ten(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 266 #define ieee754sp_indef()       (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
 267                                                    ieee754_csr.nan2008])
 268 #define ieee754sp_max(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 269 #define ieee754sp_min(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 270 #define ieee754sp_mind(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 271 #define ieee754sp_1e31()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
 272 #define ieee754sp_1e63()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
 273
 274 /*
 275  * Indefinite integer value
 276  */
 277 static inline int ieee754si_indef(void)
 278 {
 279         return ieee754_csr.nan2008 ? 0 : INT_MAX;
 280 }
 281
 282 static inline s64 ieee754di_indef(void)
 283 {
 284         return ieee754_csr.nan2008 ? 0 : S64_MAX;
 285 }
 286
 287 /*
 288  * Overflow integer value
 289  */
 290 static inline int ieee754si_overflow(int xs)
 291 {
 292         return ieee754_csr.nan2008 && xs ? INT_MIN : INT_MAX;
 293 }
 294
 295 static inline s64 ieee754di_overflow(int xs)
 296 {
 297         return ieee754_csr.nan2008 && xs ? S64_MIN : S64_MAX;
 298 }
 299
 300 /* result types for xctx.rt */
 301 #define IEEE754_RT_SP   0
 302 #define IEEE754_RT_DP   1
 303 #define IEEE754_RT_XP   2
 304 #define IEEE754_RT_SI   3
 305 #define IEEE754_RT_DI   4
 306
 307 /* compat */
 308 #define ieee754dp_fix(x)        ieee754dp_tint(x)
 309 #define ieee754sp_fix(x)        ieee754sp_tint(x)
 310
 311 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */