arch/parisc/math-emu/cnv_float.h

   1 /*
   2  * Linux/PA-RISC Project (http://www.parisc-linux.org/)
   3  *
   4  * Floating-point emulation code
   5  *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2, or (at your option)
  10  *    any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #ifdef __NO_PA_HDRS
  23     PA header file -- do not include this header file for non-PA builds.
  24 #endif
  25
  26 /*
  27  * Some more constants
  28  */
  29 #define SGL_FX_MAX_EXP 30
  30 #define DBL_FX_MAX_EXP 62
  31 #define QUAD_FX_MAX_EXP 126
  32
  33 #define Dintp1(object) (object)
  34 #define Dintp2(object) (object)
  35
  36 #define Duintp1(object) (object)
  37 #define Duintp2(object) (object)
  38
  39 #define Qintp0(object) (object)
  40 #define Qintp1(object) (object)
  41 #define Qintp2(object) (object)
  42 #define Qintp3(object) (object)
  43
  44
  45 /*
  46  * These macros will be used specifically by the convert instructions.
  47  *
  48  *
  49  * Single format macros
  50  */
  51
  52 #define Sgl_to_dbl_exponent(src_exponent,dest)                  \
  53     Deposit_dexponent(dest,src_exponent+(DBL_BIAS-SGL_BIAS))
  54
  55 #define Sgl_to_dbl_mantissa(src_mantissa,destA,destB)   \
  56     Deposit_dmantissap1(destA,src_mantissa>>3);         \
  57     Dmantissap2(destB) = src_mantissa << 29
  58
  59 #define Sgl_isinexact_to_fix(sgl_value,exponent)        \
  60     ((exponent < (SGL_P - 1)) ?                         \
  61      (Sall(sgl_value) << (SGL_EXP_LENGTH + 1 + exponent)) : FALSE)
  62
  63 #define Int_isinexact_to_sgl(int_value) ((int_value << 33 - SGL_EXP_LENGTH) != 0)
  64
  65 #define Sgl_roundnearest_from_int(int_value,sgl_value)                  \
  66     if (int_value & 1<<(SGL_EXP_LENGTH - 2))   /* round bit */          \
  67         if (((int_value << 34 - SGL_EXP_LENGTH) != 0) || Slow(sgl_value)) \
  68                 Sall(sgl_value)++
  69
  70 #define Dint_isinexact_to_sgl(dint_valueA,dint_valueB)          \
  71     (((Dintp1(dint_valueA) << 33 - SGL_EXP_LENGTH) != 0) || Dintp2(dint_valueB))
  72
  73 #define Sgl_roundnearest_from_dint(dint_valueA,dint_valueB,sgl_value)   \
  74     if (Dintp1(dint_valueA) & 1<<(SGL_EXP_LENGTH - 2))                  \
  75         if (((Dintp1(dint_valueA) << 34 - SGL_EXP_LENGTH) != 0) ||      \
  76         Dintp2(dint_valueB) || Slow(sgl_value)) Sall(sgl_value)++
  77
  78 #define Dint_isinexact_to_dbl(dint_value)       \
  79     (Dintp2(dint_value) << 33 - DBL_EXP_LENGTH)
  80
  81 #define Dbl_roundnearest_from_dint(dint_opndB,dbl_opndA,dbl_opndB)      \
  82     if (Dintp2(dint_opndB) & 1<<(DBL_EXP_LENGTH - 2))                   \
  83        if ((Dintp2(dint_opndB) << 34 - DBL_EXP_LENGTH) || Dlowp2(dbl_opndB))  \
  84           if ((++Dallp2(dbl_opndB))==0) Dallp1(dbl_opndA)++
  85
  86 #define Sgl_isone_roundbit(sgl_value,exponent)                  \
  87     ((Sall(sgl_value) << (SGL_EXP_LENGTH + 1 + exponent)) >> 31)
  88
  89 #define Sgl_isone_stickybit(sgl_value,exponent)         \
  90     (exponent < (SGL_P - 2) ?                           \
  91      Sall(sgl_value) << (SGL_EXP_LENGTH + 2 + exponent) : FALSE)
  92
  93
  94 /*
  95  * Double format macros
  96  */
  97
  98 #define Dbl_to_sgl_exponent(src_exponent,dest)                  \
  99     dest = src_exponent + (SGL_BIAS - DBL_BIAS)
 100
 101 #define Dbl_to_sgl_mantissa(srcA,srcB,dest,inexact,guard,sticky,odd)    \
 102     Shiftdouble(Dmantissap1(srcA),Dmantissap2(srcB),29,dest);   \
 103     guard = Dbit3p2(srcB);                                      \
 104     sticky = Dallp2(srcB)<<4;                                   \
 105     inexact = guard | sticky;                                   \
 106     odd = Dbit2p2(srcB)
 107
 108 #define Dbl_to_sgl_denormalized(srcA,srcB,exp,dest,inexact,guard,sticky,odd,tiny) \
 109     Deposit_dexponent(srcA,1);                                          \
 110     tiny = TRUE;                                                        \
 111     if (exp >= -2) {                                                    \
 112         if (exp == 0) {                                                 \
 113             inexact = Dallp2(srcB) << 3;                                \
 114             guard = inexact >> 31;                                      \
 115             sticky = inexact << 1;                                      \
 116             Shiftdouble(Dmantissap1(srcA),Dmantissap2(srcB),29,dest);   \
 117             odd = dest << 31;                                           \
 118             if (inexact) {                                              \
 119                 switch(Rounding_mode()) {                               \
 120                     case ROUNDPLUS:                                     \
 121                         if (Dbl_iszero_sign(srcA)) {                    \
 122                             dest++;                                     \
 123                             if (Sgl_isone_hidden(dest)) \
 124                                 tiny = FALSE;                           \
 125                             dest--;                                     \
 126                         }                                               \
 127                         break;                                          \
 128                     case ROUNDMINUS:                                    \
 129                         if (Dbl_isone_sign(srcA)) {                     \
 130                             dest++;                                     \
 131                             if (Sgl_isone_hidden(dest)) \
 132                                 tiny = FALSE;                           \
 133                             dest--;                                     \
 134                         }                                               \
 135                         break;                                          \
 136                     case ROUNDNEAREST:                                  \
 137                         if (guard && (sticky || odd)) {                 \
 138                             dest++;                                     \
 139                             if (Sgl_isone_hidden(dest)) \
 140                                 tiny = FALSE;                           \
 141                             dest--;                                     \
 142                         }                                               \
 143                         break;                                          \
 144                 }                                                       \
 145             }                                                           \
 146                 /* shift right by one to get correct result */          \
 147                 guard = odd;                                            \
 148                 sticky = inexact;                                       \
 149                 inexact |= guard;                                       \
 150                 dest >>= 1;                                             \
 151                 Deposit_dsign(srcA,0);                                  \
 152                 Shiftdouble(Dallp1(srcA),Dallp2(srcB),30,dest);         \
 153                 odd = dest << 31;                                       \
 154         }                                                               \
 155         else {                                                          \
 156             inexact = Dallp2(srcB) << (2 + exp);                        \
 157             guard = inexact >> 31;                                      \
 158             sticky = inexact << 1;                                      \
 159             Deposit_dsign(srcA,0);                                      \
 160             if (exp == -2) dest = Dallp1(srcA);                         \
 161             else Variable_shift_double(Dallp1(srcA),Dallp2(srcB),30-exp,dest); \
 162             odd = dest << 31;                                           \
 163         }                                                               \
 164     }                                                                   \
 165     else {                                                              \
 166         Deposit_dsign(srcA,0);                                          \
 167         if (exp > (1 - SGL_P)) {                                        \
 168             dest = Dallp1(srcA) >> (- 2 - exp);                         \
 169             inexact = Dallp1(srcA) << (34 + exp);                       \
 170             guard = inexact >> 31;                                      \
 171             sticky = (inexact << 1) | Dallp2(srcB);                     \
 172             inexact |= Dallp2(srcB);                                    \
 173             odd = dest << 31;                                           \
 174         }                                                               \
 175         else {                                                          \
 176             dest = 0;                                                   \
 177             inexact = Dallp1(srcA) | Dallp2(srcB);                      \
 178             if (exp == (1 - SGL_P)) {                                   \
 179                 guard = Dhidden(srcA);                                  \
 180                 sticky = Dmantissap1(srcA) | Dallp2(srcB);              \
 181             }                                                           \
 182             else {                                                      \
 183                 guard = 0;                                              \
 184                 sticky = inexact;                                       \
 185             }                                                           \
 186             odd = 0;                                                    \
 187         }                                                               \
 188     }                                                                   \
 189     exp = 0
 190
 191 #define Dbl_isinexact_to_fix(dbl_valueA,dbl_valueB,exponent)            \
 192     (exponent < (DBL_P-33) ?                                            \
 193      Dallp2(dbl_valueB) || Dallp1(dbl_valueA) << (DBL_EXP_LENGTH+1+exponent) : \
 194      (exponent < (DBL_P-1) ? Dallp2(dbl_valueB) << (exponent + (33-DBL_P)) :   \
 195       FALSE))
 196
 197 #define Dbl_isoverflow_to_int(exponent,dbl_valueA,dbl_valueB)           \
 198     ((exponent > SGL_FX_MAX_EXP + 1) || Dsign(dbl_valueA)==0 ||         \
 199      Dmantissap1(dbl_valueA)!=0 || (Dallp2(dbl_valueB)>>21)!=0 )
 200
 201 #define Dbl_isone_roundbit(dbl_valueA,dbl_valueB,exponent)              \
 202     ((exponent < (DBL_P - 33) ?                                         \
 203       Dallp1(dbl_valueA) >> ((30 - DBL_EXP_LENGTH) - exponent) :        \
 204       Dallp2(dbl_valueB) >> ((DBL_P - 2) - exponent)) & 1)
 205
 206 #define Dbl_isone_stickybit(dbl_valueA,dbl_valueB,exponent)             \
 207     (exponent < (DBL_P-34) ?                                            \
 208      (Dallp2(dbl_valueB) || Dallp1(dbl_valueA)<<(DBL_EXP_LENGTH+2+exponent)) : \
 209      (exponent<(DBL_P-2) ? (Dallp2(dbl_valueB) << (exponent + (34-DBL_P))) : \
 210       FALSE))
 211
 212
 213 /* Int macros */
 214
 215 #define Int_from_sgl_mantissa(sgl_value,exponent)       \
 216     Sall(sgl_value) =                           \
 217         (unsigned)(Sall(sgl_value) << SGL_EXP_LENGTH)>>(31 - exponent)
 218
 219 #define Int_from_dbl_mantissa(dbl_valueA,dbl_valueB,exponent)   \
 220     Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),22,Dallp1(dbl_valueA)); \
 221     if (exponent < 31) Dallp1(dbl_valueA) >>= 30 - exponent;    \
 222     else Dallp1(dbl_valueA) <<= 1
 223
 224 #define Int_negate(int_value) int_value = -int_value
 225
 226
 227 /* Dint macros */
 228
 229 #define Dint_from_sgl_mantissa(sgl_value,exponent,dresultA,dresultB)    \
 230     {Sall(sgl_value) <<= SGL_EXP_LENGTH;  /*  left-justify  */          \
 231     if (exponent <= 31) {                                               \
 232         Dintp1(dresultA) = 0;                                           \
 233         Dintp2(dresultB) = (unsigned)Sall(sgl_value) >> (31 - exponent); \
 234     }                                                                   \
 235     else {                                                              \
 236         Dintp1(dresultA) = Sall(sgl_value) >> (63 - exponent);          \
 237         Dintp2(dresultB) = Sall(sgl_value) << (exponent - 31);          \
 238     }}
 239
 240
 241 #define Dint_from_dbl_mantissa(dbl_valueA,dbl_valueB,exponent,destA,destB) \
 242     {if (exponent < 32) {                                               \
 243         Dintp1(destA) = 0;                                              \
 244         if (exponent <= 20)                                             \
 245             Dintp2(destB) = Dallp1(dbl_valueA) >> 20-exponent;          \
 246         else Variable_shift_double(Dallp1(dbl_valueA),Dallp2(dbl_valueB), \
 247              52-exponent,Dintp2(destB));                                        \
 248     }                                                                   \
 249     else {                                                              \
 250         if (exponent <= 52) {                                           \
 251             Dintp1(destA) = Dallp1(dbl_valueA) >> 52-exponent;          \
 252             if (exponent == 52) Dintp2(destB) = Dallp2(dbl_valueB);     \
 253             else Variable_shift_double(Dallp1(dbl_valueA),Dallp2(dbl_valueB), \
 254             52-exponent,Dintp2(destB));                                 \
 255         }                                                               \
 256         else {                                                          \
 257             Variable_shift_double(Dallp1(dbl_valueA),Dallp2(dbl_valueB), \
 258             84-exponent,Dintp1(destA));                                 \
 259             Dintp2(destB) = Dallp2(dbl_valueB) << exponent-52;          \
 260         }                                                               \
 261     }}
 262
 263 #define Dint_setzero(dresultA,dresultB)         \
 264     Dintp1(dresultA) = 0;       \
 265     Dintp2(dresultB) = 0
 266
 267 #define Dint_setone_sign(dresultA,dresultB)             \
 268     Dintp1(dresultA) = ~Dintp1(dresultA);               \
 269     if ((Dintp2(dresultB) = -Dintp2(dresultB)) == 0) Dintp1(dresultA)++
 270
 271 #define Dint_set_minint(dresultA,dresultB)              \
 272     Dintp1(dresultA) = (unsigned int)1<<31;             \
 273     Dintp2(dresultB) = 0
 274
 275 #define Dint_isone_lowp2(dresultB)  (Dintp2(dresultB) & 01)
 276
 277 #define Dint_increment(dresultA,dresultB)               \
 278     if ((++Dintp2(dresultB))==0) Dintp1(dresultA)++
 279
 280 #define Dint_decrement(dresultA,dresultB)               \
 281     if ((Dintp2(dresultB)--)==0) Dintp1(dresultA)--
 282
 283 #define Dint_negate(dresultA,dresultB)                  \
 284     Dintp1(dresultA) = ~Dintp1(dresultA);               \
 285     if ((Dintp2(dresultB) = -Dintp2(dresultB))==0) Dintp1(dresultA)++
 286
 287 #define Dint_copyfromptr(src,destA,destB) \
 288      Dintp1(destA) = src->wd0;          \
 289      Dintp2(destB) = src->wd1
 290 #define Dint_copytoptr(srcA,srcB,dest)  \
 291     dest->wd0 = Dintp1(srcA);           \
 292     dest->wd1 = Dintp2(srcB)
 293
 294
 295 /* other macros  */
 296
 297 #define Find_ms_one_bit(value, position)        \
 298     {                                           \
 299         int var;                                \
 300         for (var=8; var >=1; var >>= 1) {       \
 301             if (value >> 32 - position)         \
 302                 position -= var;                \
 303                 else position += var;           \
 304         }                                       \
 305         if ((value >> 32 - position) == 0)      \
 306             position--;                         \
 307         else position -= 2;                     \
 308     }
 309
 310
 311 /*
 312  * Unsigned int macros
 313  */
 314 #define Duint_copyfromptr(src,destA,destB) \
 315     Dint_copyfromptr(src,destA,destB)
 316 #define Duint_copytoptr(srcA,srcB,dest) \
 317     Dint_copytoptr(srcA,srcB,dest)
 318
 319 #define Suint_isinexact_to_sgl(int_value) \
 320     (int_value << 32 - SGL_EXP_LENGTH)
 321
 322 #define Sgl_roundnearest_from_suint(suint_value,sgl_value)              \
 323     if (suint_value & 1<<(SGL_EXP_LENGTH - 1))   /* round bit */        \
 324         if ((suint_value << 33 - SGL_EXP_LENGTH) || Slow(sgl_value))    \
 325                 Sall(sgl_value)++
 326
 327 #define Duint_isinexact_to_sgl(duint_valueA,duint_valueB)       \
 328     ((Duintp1(duint_valueA) << 32 - SGL_EXP_LENGTH) || Duintp2(duint_valueB))
 329
 330 #define Sgl_roundnearest_from_duint(duint_valueA,duint_valueB,sgl_value) \
 331     if (Duintp1(duint_valueA) & 1<<(SGL_EXP_LENGTH - 1))                \
 332         if ((Duintp1(duint_valueA) << 33 - SGL_EXP_LENGTH) ||           \
 333         Duintp2(duint_valueB) || Slow(sgl_value)) Sall(sgl_value)++
 334
 335 #define Duint_isinexact_to_dbl(duint_value)     \
 336     (Duintp2(duint_value) << 32 - DBL_EXP_LENGTH)
 337
 338 #define Dbl_roundnearest_from_duint(duint_opndB,dbl_opndA,dbl_opndB)    \
 339     if (Duintp2(duint_opndB) & 1<<(DBL_EXP_LENGTH - 1))                 \
 340        if ((Duintp2(duint_opndB) << 33 - DBL_EXP_LENGTH) || Dlowp2(dbl_opndB)) \
 341           if ((++Dallp2(dbl_opndB))==0) Dallp1(dbl_opndA)++
 342
 343 #define Suint_from_sgl_mantissa(src,exponent,result)    \
 344     Sall(result) = (unsigned)(Sall(src) << SGL_EXP_LENGTH)>>(31 - exponent)
 345
 346 #define Sgl_isinexact_to_unsigned(sgl_value,exponent)   \
 347     Sgl_isinexact_to_fix(sgl_value,exponent)
 348
 349 #define Duint_from_sgl_mantissa(sgl_value,exponent,dresultA,dresultB)   \
 350   {unsigned int val = Sall(sgl_value) << SGL_EXP_LENGTH;                \
 351     if (exponent <= 31) {                                               \
 352         Dintp1(dresultA) = 0;                                           \
 353         Dintp2(dresultB) = val >> (31 - exponent);                      \
 354     }                                                                   \
 355     else {                                                              \
 356         Dintp1(dresultA) = val >> (63 - exponent);                      \
 357         Dintp2(dresultB) = exponent <= 62 ? val << (exponent - 31) : 0; \
 358     }                                                                   \
 359   }
 360
 361 #define Duint_setzero(dresultA,dresultB)        \
 362     Dint_setzero(dresultA,dresultB)
 363
 364 #define Duint_increment(dresultA,dresultB) Dint_increment(dresultA,dresultB)
 365
 366 #define Duint_isone_lowp2(dresultB)  Dint_isone_lowp2(dresultB)
 367
 368 #define Suint_from_dbl_mantissa(srcA,srcB,exponent,dest) \
 369     Shiftdouble(Dallp1(srcA),Dallp2(srcB),21,dest); \
 370     dest = (unsigned)dest >> 31 - exponent
 371
 372 #define Dbl_isinexact_to_unsigned(dbl_valueA,dbl_valueB,exponent) \
 373     Dbl_isinexact_to_fix(dbl_valueA,dbl_valueB,exponent)
 374
 375 #define Duint_from_dbl_mantissa(dbl_valueA,dbl_valueB,exponent,destA,destB) \
 376     Dint_from_dbl_mantissa(dbl_valueA,dbl_valueB,exponent,destA,destB)