Shamusworld >> Repos - rmac/blob - eagen0.c

   1 //
   2 // RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System
   3 // EAGEN0.C - Effective Address Code Generation
   4 //            Generated Code for eaN (Included twice by "eagen.c")
   5 // Copyright (C) 199x Landon Dyer, 2017 Reboot and Friends
   6 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
   7 // Source utilised with the kind permission of Landon Dyer
   8 //
   9
  10 int eaNgen(WORD siz)
  11 {
  12         VALUE vbd, v = aNexval;
  13         WORD wbd, w = (WORD)(aNexattr & DEFINED);
  14         WORD tdbbd, tdb = (WORD)(aNexattr & TDB);
  15     vbd = aNbdexval;
  16     wbd = (WORD)(aNbdexattr & DEFINED);
  17     tdbbd = (WORD)(aNbdexattr & TDB);
  18
  19         switch (amN)
  20         {
  21         // "Do nothing" - they're in the opword
  22         case DREG:
  23         case AREG:
  24         case AIND:
  25         case APOSTINC:
  26         case APREDEC:
  27         case AM_USP:
  28         case AM_CCR:
  29         case AM_SR:
  30         case AM_NONE:
  31                 // This is a performance hit, though
  32                 break;
  33         case ADISP:
  34                 // expr(An)
  35                 if (w)
  36                 {
  37                         // Just deposit it
  38                         if (tdb)
  39                                 MarkRelocatable(cursect, sloc, tdb, MWORD, NULL);
  40
  41                         if ((v == 0) && optim_flags[OPT_INDIRECT_DISP] && !movep)
  42                         {
  43                                 // If expr is 0, size optimise the opcode. Generally the lower
  44                                 // 6 bits of the opcode for expr(ax) are 101rrr where rrr=the
  45                                 // number of the register, then followed by a word containing
  46                                 // 'expr'. We need to change that to 010rrr.
  47                                 if ((siz & 0x8000) == 0)
  48                                 {
  49                                         chptr_opcode[0] &= ((0xFFC7 >> 8) & 255); // mask off bits
  50                                         chptr_opcode[1] &= 0xFFC7 & 255;          // mask off bits
  51                                         chptr_opcode[0] |= ((0x0010 >> 8) & 255); // slap in 010 bits
  52                                         chptr_opcode[1] |= 0x0010 & 255;          // slap in 010 bits
  53                                 }
  54                                 else
  55                                 {
  56                                         // Special case for move ea,ea: there are two ea fields
  57                                         // there and we get a signal if it's the second ea field
  58                                         // from m_ea - siz's 16th bit is set
  59                                         chptr_opcode[0] &= ((0xFE3F >> 8) & 255); // mask off bits
  60                                         chptr_opcode[1] &= 0xFE3F & 255;          // mask off bits
  61                                         chptr_opcode[0] |= ((0x0080 >> 8) & 255); // slap in 010 bits
  62                                         chptr_opcode[1] |= 0x0080 & 255;          // slap in 010 bits
  63                                 }
  64
  65                                 if (sbra_flag)
  66                                         warn("0(An) converted to (An)");
  67
  68                                 return OK;
  69                         }
  70
  71                         if ((v + 0x8000) >= 0x18000)
  72                                 return error(range_error);
  73
  74                         D_word(v);
  75                 }
  76                 else
  77                 {
  78                         // Arrange for fixup later on
  79                         AddFixup(FU_WORD | FU_SEXT, sloc, aNexpr);
  80                         D_word(0);
  81                 }
  82
  83                 break;
  84         case PCDISP:
  85                 if (w)
  86                 {
  87                         // Just deposit it
  88                         if ((aNexattr & TDB) == cursect)
  89                                 v -= (VALUE)sloc;
  90                         else if ((aNexattr & TDB) != ABS)
  91                                 error(rel_error);
  92
  93                         if (v + 0x8000 >= 0x10000)
  94                                 return error(range_error);
  95
  96                         D_word(v);
  97                 }
  98                 else
  99                 {
 100                         // Arrange for fixup later on
 101                         AddFixup(FU_WORD | FU_SEXT | FU_PCREL, sloc, aNexpr);
 102                         D_word(0);
 103                 }
 104
 105                 break;
 106         case AINDEXED:
 107                 // Compute ixreg and size+scale
 108                 w = (WORD)((aNixreg << 12) | aNixsiz);
 109
 110                 if (aNexattr & DEFINED)
 111                 {
 112                         // Deposit a byte...
 113                         if (tdb)
 114                                 // Can't mark bytes
 115                                 return error(abs_error);
 116
 117                         if (v + 0x80 >= 0x180)
 118                                 return error(range_error);
 119
 120                         w |= v & 0xFF;
 121                         D_word(w);
 122                 }
 123                 else
 124                 {
 125                         // Fixup the byte later
 126                         AddFixup(FU_BYTE | FU_SEXT, sloc + 1, aNexpr);
 127                         D_word(w);
 128                 }
 129
 130                 break;
 131         case PCINDEXED:
 132                 // Compute ixreg and size+scale
 133                 w = (WORD)((aNixreg << 12) | aNixsiz);
 134
 135                 if (aNexattr & DEFINED)
 136                 {
 137                         // Deposit a byte...
 138                         if ((aNexattr & TDB) == cursect)
 139                                 v -= (VALUE)sloc;
 140                         else if ((aNexattr & TDB) != ABS)
 141                                 error(rel_error);
 142
 143                         if (v + 0x80 >= 0x100)
 144                                 return error(range_error);
 145
 146                         w |= v & 0xFF;
 147                         D_word(w);
 148                 }
 149                 else
 150                 {
 151                         // Fixup the byte later
 152                         AddFixup(FU_WBYTE | FU_SEXT | FU_PCREL, sloc, aNexpr);
 153                         D_word(w);
 154                 }
 155
 156                 break;
 157         case IMMED:
 158                 switch (siz)
 159                 {
 160                 case SIZB:
 161                         if (w)
 162                         {
 163                                 if (tdb)
 164                                         return error("illegal byte-sized relative reference");
 165
 166                                 if (v + 0x100 >= 0x200)
 167                                         return error(range_error);
 168
 169                                 D_word(v);
 170                         }
 171                         else
 172                         {
 173                                 AddFixup(FU_BYTE | FU_SEXT, sloc + 1, aNexpr);
 174                                 D_word(0);
 175                         }
 176
 177                         break;
 178                 case SIZW:
 179                 case SIZN:
 180                         if (w)
 181                         {
 182                                 if (v + 0x10000 >= 0x20000)
 183                                         return error(range_error);
 184
 185                                 if (tdb)
 186                                         MarkRelocatable(cursect, sloc, tdb, MWORD, NULL);
 187
 188                                 D_word(v);
 189                         }
 190                         else
 191                         {
 192                                 AddFixup(FU_WORD | FU_SEXT, sloc, aNexpr);
 193                                 D_word(0);
 194                         }
 195
 196                         break;
 197                 case SIZL:
 198                         if (w)
 199                         {
 200                                 if (tdb)
 201                                         MarkRelocatable(cursect, sloc, tdb, MLONG, NULL);
 202
 203                                 D_long(v);
 204                         }
 205                         else
 206                         {
 207                                 AddFixup(FU_LONG, sloc, aNexpr);
 208                                 D_long(0);
 209                         }
 210
 211                         break;
 212                 default:
 213                         // IMMED size problem
 214                         interror(1);
 215                 }
 216
 217                 break;
 218     case SIZP:
 219             // 68881/68882/68040 only
 220             return error("Sorry, .p constant format is not implemented yet!");
 221             break;
 222         case ABSW:
 223                 if (w) // Defined
 224                 {
 225                         if (tdb)
 226                                 MarkRelocatable(cursect, sloc, tdb, MWORD, NULL);
 227
 228                         if (v + 0x8000 >= 0x10000)
 229                                 return error(range_error);
 230
 231                         D_word(v);
 232                 }
 233                 else
 234                 {
 235                         AddFixup(FU_WORD | FU_SEXT, sloc, aNexpr);
 236                         D_word(0);
 237                 }
 238
 239                 break;
 240         case ABSL:
 241                 if (w) // Defined
 242                 {
 243                         if (tdb)
 244                                 MarkRelocatable(cursect, sloc, tdb, MLONG, NULL);
 245
 246                         D_long(v);
 247                 }
 248                 else
 249                 {
 250                         AddFixup(FU_LONG, sloc, aNexpr);
 251                         D_long(0);
 252                 }
 253
 254                 break;
 255         case ABASE:
 256         case MEMPOST:
 257         case MEMPRE:
 258         case PCBASE:
 259         case PCMPOST:
 260         case PCMPRE:
 261                 D_word(aNexten);
 262                 // Deposit bd (if not suppressed)
 263                 if ((aNexten&0x0030)==EXT_BDSIZE0)
 264                 {
 265                         // Don't deposit anything (suppressed)
 266                 }
 267                 else if ((aNexten&0x0030)==EXT_BDSIZEW)
 268                 {
 269                         // Deposit word bd
 270                         if (wbd)
 271                         {
 272                                 // Just deposit it
 273                                 if (tdb)
 274                                         MarkRelocatable(cursect, sloc, tdbbd, MWORD, NULL);
 275
 276                                 if (vbd + 0x8000 >= 0x10000)
 277                                         return error(range_error);
 278
 279                                 D_word(vbd);
 280                         }
 281                         else
 282                         {
 283                                 // Arrange for fixup later on
 284                                 AddFixup(FU_WORD|FU_SEXT, sloc, aNexpr);
 285                                 D_word(0);
 286                         }
 287                 }
 288                 else
 289                 {
 290                         // Deposit long bd
 291                         if (wbd)
 292                         {
 293                                 // Just deposit it
 294                                 if (tdbbd)
 295                                         MarkRelocatable(cursect, sloc, tdbbd, MLONG, NULL);
 296
 297                                 D_long(vbd);
 298                         }
 299                         else
 300                         {
 301                                 // Arrange for fixup later on
 302                                 AddFixup(FU_LONG|FU_SEXT, sloc, aNexpr);
 303                                 D_long(0);
 304                         }
 305                 }
 306                 // Deposit od (if not suppressed)
 307                 if ((aNexten&7)==EXT_IISPRE0 || (aNexten&7)==EXT_IISPREN
 308                         || (aNexten&7)==EXT_IISNOIN || (aNexten&7)==EXT_IISPOSN)
 309                 {
 310                         // Don't deposit anything (suppressed)
 311                 }
 312                 else if ((aNexten&7)==EXT_IISPREW
 313                         || (aNexten&7)==EXT_IISPOSW || (aNexten&7)==EXT_IISNOIW)
 314                 {
 315                         // Deposit word od
 316                         if (w)
 317                         {
 318                                 // Just deposit it
 319                                 if (tdb)
 320                                         MarkRelocatable(cursect, sloc, tdb, MWORD, NULL);
 321
 322                                 if (v + 0x8000 >= 0x10000)
 323                                         return error(range_error);
 324
 325                                 D_word(v);
 326                         }
 327                         else
 328                         {
 329                                 // Arrange for fixup later on
 330                                 AddFixup(FU_WORD|FU_SEXT, sloc, aNexpr);
 331                                 D_word(0);
 332                         }
 333                 }
 334                 else
 335                 {
 336                         // Deposit long od
 337                         if (w)
 338                         {
 339                                 // Just deposit it
 340                                 if (tdb)
 341                                         MarkRelocatable(cursect, sloc, tdb, MLONG, NULL);
 342
 343                                 D_long(v);
 344                         }
 345                         else
 346                         {
 347                                 // Arrange for fixup later on
 348                                 AddFixup(FU_LONG|FU_SEXT, sloc, aNexpr);
 349                                 D_long(0);
 350                         }
 351                 }
 352
 353                 break;
 354                 //return error("unsupported 68020 addressing mode");
 355         default:
 356                 // Bad addressing mode in ea gen
 357                 interror(3);
 358         }
 359
 360         return OK;
 361 }
 362
 363 // Undefine dirty macros
 364 #undef eaNgen
 365 #undef amN
 366 #undef aNexattr
 367 #undef aNexval
 368 #undef aNexpr
 369 #undef aNixreg
 370 #undef aNixsiz
 371 #undef aNexten
 372 #undef aNbdexval
 373 #undef aNbdexattr
 374 #undef AnESYM
 375