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

   1 //
   2 // RMAC - Reboot's Macro Assembler for all Atari computers
   3 // RISCA.C - GPU/DSP Assembler
   4 // Copyright (C) 199x Landon Dyer, 2011-2020 Reboot and Friends
   5 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
   6 // Source utilised with the kind permission of Landon Dyer
   7 //
   8
   9 #include "riscasm.h"
  10 #include "amode.h"
  11 #include "direct.h"
  12 #include "error.h"
  13 #include "expr.h"
  14 #include "mark.h"
  15 #include "procln.h"
  16 #include "rmac.h"
  17 #include "sect.h"
  18 #include "token.h"
  19
  20 #define DEF_MR                          // Declare keyword values
  21 #include "risckw.h"                     // Incl. generated risc keywords
  22
  23 #define DEF_KW                          // Declare keyword values
  24 #include "kwtab.h"                      // Incl. generated keyword tables & defs
  25
  26 #define MAXINTERNCC 26          // Maximum internal condition codes
  27
  28
  29 unsigned altbankok = 0;         // Ok to use alternate register bank
  30 unsigned orgactive = 0;         // RISC/6502 org directive active
  31 unsigned orgaddr = 0;           // Org'd address
  32 unsigned orgwarning = 0;        // Has an ORG warning been issued
  33 int lastOpcode = -1;            // Last RISC opcode assembled
  34 uint8_t riscImmTokenSeen;       // The '#' (immediate) token was seen
  35
  36 static const char reg_err[] = "missing register R0...R31";
  37
  38 // Jaguar jump condition names
  39 static const char condname[MAXINTERNCC][5] = {
  40         "NZ", "Z", "NC", "NCNZ", "NCZ", "C", "CNZ", "CZ", "NN", "NNNZ", "NNZ",
  41         "N", "N_NZ", "N_Z", "T", "A", "NE", "EQ", "CC", "HS", "HI", "CS", "LO",
  42         "PL", "MI", "F"
  43 };
  44
  45 // Jaguar jump condition numbers
  46 static const char condnumber[] = {
  47         1, 2, 4, 5, 6, 8, 9, 10, 20, 21, 22, 24, 25, 26,
  48         0, 0, 1, 2, 4, 4, 5,  8,  8, 20, 24, 31
  49 };
  50
  51 // Opcode Specific Data
  52 struct opcoderecord {
  53         uint16_t state;         // Opcode Name (unused)
  54         uint16_t type;          // Opcode Type
  55         uint16_t param;         // Opcode Parameter
  56 };
  57
  58 static const struct opcoderecord roptbl[] = {
  59         { MR_ADD,     RI_TWO,    0 },
  60         { MR_ADDC,    RI_TWO,    1 },
  61         { MR_ADDQ,    RI_NUM_32, 2 },
  62         { MR_ADDQT,   RI_NUM_32, 3 },
  63         { MR_SUB,     RI_TWO,    4 },
  64         { MR_SUBC,    RI_TWO,    5 },
  65         { MR_SUBQ,    RI_NUM_32, 6 },
  66         { MR_SUBQT,   RI_NUM_32, 7 },
  67         { MR_NEG,     RI_ONE,    8 },
  68         { MR_AND,     RI_TWO,    9 },
  69         { MR_OR,      RI_TWO,    10 },
  70         { MR_XOR,     RI_TWO,    11 },
  71         { MR_NOT,     RI_ONE,    12 },
  72         { MR_BTST,    RI_NUM_31, 13 },
  73         { MR_BSET,    RI_NUM_31, 14 },
  74         { MR_BCLR,    RI_NUM_31, 15 },
  75         { MR_MULT,    RI_TWO,    16 },
  76         { MR_IMULT,   RI_TWO,    17 },
  77         { MR_IMULTN,  RI_TWO,    18 },
  78         { MR_RESMAC,  RI_ONE,    19 },
  79         { MR_IMACN,   RI_TWO,    20 },
  80         { MR_DIV,     RI_TWO,    21 },
  81         { MR_ABS,     RI_ONE,    22 },
  82         { MR_SH,      RI_TWO,    23 },
  83         { MR_SHLQ,    RI_NUM_32, 24 + SUB32 },
  84         { MR_SHRQ,    RI_NUM_32, 25 },
  85         { MR_SHA,     RI_TWO,    26 },
  86         { MR_SHARQ,   RI_NUM_32, 27 },
  87         { MR_ROR,     RI_TWO,    28 },
  88         { MR_RORQ,    RI_NUM_32, 29 },
  89         { MR_ROLQ,    RI_NUM_32, 29 + SUB32 },
  90         { MR_CMP,     RI_TWO,    30 },
  91         { MR_CMPQ,    RI_NUM_15, 31 },
  92         { MR_SAT8,    RI_ONE,    32 + GPUONLY },
  93         { MR_SUBQMOD, RI_NUM_32, 32 + DSPONLY },
  94         { MR_SAT16,   RI_ONE,    33 + GPUONLY },
  95         { MR_SAT16S,  RI_ONE,    33 + DSPONLY },
  96         { MR_MOVEQ,   RI_NUM_31, 35 },
  97         { MR_MOVETA,  RI_TWO,    36 },
  98         { MR_MOVEFA,  RI_TWO,    37 },
  99         { MR_MOVEI,   RI_MOVEI,  38 },
 100         { MR_LOADB,   RI_LOADN,  39 },
 101         { MR_LOADW,   RI_LOADN,  40 },
 102         { MR_LOADP,   RI_LOADN,  42 + GPUONLY },
 103         { MR_SAT32S,  RI_ONE,    42 + DSPONLY },
 104         { MR_STOREB,  RI_STOREN, 45 },
 105         { MR_STOREW,  RI_STOREN, 46 },
 106         { MR_STOREP,  RI_STOREN, 48 + GPUONLY },
 107         { MR_MIRROR,  RI_ONE,    48 + DSPONLY },
 108         { MR_JUMP,    RI_JUMP,   52 },
 109         { MR_JR,      RI_JR,     53 },
 110         { MR_MMULT,   RI_TWO,    54 },
 111         { MR_MTOI,    RI_TWO,    55 },
 112         { MR_NORMI,   RI_TWO,    56 },
 113         { MR_NOP,     RI_NONE,   57 },
 114         { MR_SAT24,   RI_ONE,    62 },
 115         { MR_UNPACK,  RI_ONE,    63 + GPUONLY | (0 << 6) },
 116         { MR_PACK,    RI_ONE,    63 + GPUONLY | (1 << 6) },
 117         { MR_ADDQMOD, RI_NUM_32, 63 + DSPONLY },
 118         { MR_MOVE,    RI_MOVE,   0 },
 119         { MR_LOAD,    RI_LOAD,   0 },
 120         { MR_STORE,   RI_STORE,  0 }
 121 };
 122
 123 #define MALF_NUM                0
 124 #define MALF_EXPR               1
 125 #define MALF_LPAREN             2
 126 #define MALF_RPAREN             3
 127
 128 static const char malform1[] = "missing '#'";
 129 static const char malform2[] = "bad expression";
 130 static const char malform3[] = "missing ')'";
 131 static const char malform4[] = "missing '('";
 132
 133 static const char * malformErr[] = {
 134         malform1, malform2, malform3, malform4
 135 };
 136
 137
 138 //
 139 // Function to return "malformed expression" error
 140 // This is done mainly to remove a bunch of GOTO statements in the parser
 141 //
 142 static inline int MalformedOpcode(int signal)
 143 {
 144         return error("Malformed opcode, %s", malformErr[signal]);
 145 }
 146
 147
 148 //
 149 // Function to return "Illegal Indexed Register" error
 150 // Anyone trying to index something other than R14 or R15
 151 //
 152 static inline int IllegalIndexedRegister(int reg)
 153 {
 154         return error("Attempted index reference with non-indexable register (r%d)", reg - KW_R0);
 155 }
 156
 157
 158 //
 159 // Function to return "Illegal Indexed Register" error for EQUR scenarios
 160 // Trying to use register value within EQUR that isn't 14 or 15
 161 //
 162 static inline int IllegalIndexedRegisterEqur(SYM * sy)
 163 {
 164         return error("Attempted index reference with non-indexable register within EQUR (%s = r%d)", sy->sname, sy->svalue);
 165 }
 166
 167
 168 //
 169 // Build up & deposit RISC instruction word
 170 //
 171 static void DepositRISCInstructionWord(uint16_t opcode, int reg1, int reg2)
 172 {
 173         // Check for absolute address setting
 174         if (!orgwarning && !orgactive)
 175         {
 176                 warn("RISC code generated with no origin defined");
 177                 orgwarning = 1;
 178         }
 179
 180         int value = ((opcode & 0x3F) << 10) + ((reg1 & 0x1F) << 5) + (reg2 & 0x1F);
 181         D_word(value);
 182 }
 183
 184
 185 //
 186 // Evaluate the RISC register from the token stream. Passed in value is the
 187 // FIXUP attribute to use if the expression comes back as undefined.
 188 //
 189 static int EvaluateRegisterFromTokenStream(uint32_t attr)
 190 {
 191         uint64_t eval;                          // Expression value
 192         WORD eattr;                                     // Expression attributes
 193         SYM * esym;                                     // External symbol involved in expr.
 194         TOKEN r_expr[EXPRSIZE];         // Expression token list
 195
 196         // Evaluate what's in the global "tok" buffer
 197         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 198                 return ERROR;
 199
 200         if (!(eattr & DEFINED))
 201         {
 202                 AddFixup(FU_WORD | attr, sloc, r_expr);
 203                 return 0;
 204         }
 205
 206         // If we got a register in range (0-31), return it
 207         if (eval <= 31)
 208                 return (int)eval;
 209
 210         // Otherwise, it's out of range & we flag an error
 211         return error(reg_err);
 212 }
 213
 214
 215 //
 216 // Do RISC code generation
 217 //
 218 int GenerateRISCCode(int state)
 219 {
 220         int reg1;                                       // Register 1
 221         int reg2;                                       // Register 2
 222         int val = 0;                            // Constructed value
 223         char scratch[80];
 224         SYM * ccsym;
 225         SYM * sy;
 226         int i, commaFound;
 227         TOKEN * t;
 228         uint16_t attrflg;
 229         int indexed;                            // Indexed register flag
 230
 231         uint64_t eval;                          // Expression value
 232         uint16_t eattr;                         // Expression attributes
 233         SYM * esym;                                     // External symbol involved in expr.
 234         TOKEN r_expr[EXPRSIZE];         // Expression token list
 235
 236         // Get opcode parameter and type
 237         uint16_t parm = roptbl[state - 3000].param;
 238         uint16_t type = roptbl[state - 3000].type;
 239         riscImmTokenSeen = 0;           // Set to "token not seen yet"
 240
 241         // Detect whether the opcode parmeter passed determines that the opcode is
 242         // specific to only one of the RISC processors and ensure it is legal in
 243         // the current code section. If not then show error and return.
 244         if (((parm & GPUONLY) && rdsp) || ((parm & DSPONLY) && rgpu))
 245                 return error("Opcode is not valid in this code section");
 246
 247         // Process RISC opcode
 248         switch (type)
 249         {
 250         // No operand instructions
 251         // NOP (57)
 252         case RI_NONE:
 253                 DepositRISCInstructionWord(parm, 0, 0);
 254                 break;
 255
 256         // Single operand instructions (Rd)
 257         // ABS, MIRROR, NEG, NOT, PACK, RESMAC, SAT8, SAT16, SAT16S, SAT24, SAT32S,
 258         // UNPACK
 259         case RI_ONE:
 260                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 261                 ErrorIfNotAtEOL();
 262                 DepositRISCInstructionWord(parm, parm >> 6, reg2);
 263                 break;
 264
 265         // Two operand instructions (Rs,Rd)
 266         // ADD, ADDC, AND, CMP, DIV, IMACN, IMULT, IMULTN, MOVEFA, MOVETA, MULT,
 267         // MMULT, MTOI, NORMI, OR, ROR, SH, SHA, SUB, SUBC, XOR
 268         case RI_TWO:
 269                 if (parm == 37)
 270                         altbankok = 1;                      // MOVEFA
 271
 272                 reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 273                 CHECK_COMMA;
 274
 275                 if (parm == 36)
 276                         altbankok = 1;                      // MOVETA
 277
 278                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 279                 ErrorIfNotAtEOL();
 280                 DepositRISCInstructionWord(parm, reg1, reg2);
 281                 break;
 282
 283         // Numeric operand (n,Rd) where n = -16..+15
 284         // CMPQ
 285         case RI_NUM_15:
 286
 287         // Numeric operand (n,Rd) where n = 0..31
 288         // BCLR, BSET, BTST, MOVEQ
 289         case RI_NUM_31:
 290
 291         // Numeric operand (n,Rd) where n = 1..32
 292         // ADDQ, ADDQMOD, ADDQT, SHARQ, SHLQ, SHRQ, SUBQ, SUBQMOD, SUBQT, ROLQ,
 293         // RORQ
 294         case RI_NUM_32:
 295                 switch (type)
 296                 {
 297                 case RI_NUM_15:
 298                         reg1 = -16; reg2 = 15; attrflg = FU_NUM15;
 299                         break;
 300                 default:
 301                 case RI_NUM_31:
 302                         reg1 =   0; reg2 = 31; attrflg = FU_NUM31;
 303                         break;
 304                 case RI_NUM_32:
 305                         reg1 =   1; reg2 = 32; attrflg = FU_NUM32;
 306                         break;
 307                 }
 308
 309                 if (parm & SUB32)
 310                         attrflg |= FU_SUB32;
 311
 312                 if (*tok != '#')
 313                         return MalformedOpcode(MALF_NUM);
 314
 315                 tok++;
 316                 riscImmTokenSeen = 1;
 317
 318                 if (expr(r_expr, &eval, &eattr, &esym) != OK)
 319                         return MalformedOpcode(MALF_EXPR);
 320
 321                 if (!(eattr & DEFINED))
 322                 {
 323                         AddFixup((WORD)(FU_WORD | attrflg), sloc, r_expr);
 324                         reg1 = 0;
 325                 }
 326                 else
 327                 {
 328                         if (esym && (esym->sattre & EQUATEDREG))
 329                                 return error("equated register seen for immediate value");
 330
 331                         if (eattr & RISCREG)
 332                                 return error("register seen for immediate value");
 333
 334                         if (((int)eval < reg1) || ((int)eval > reg2))
 335                                 return error("constant out of range (%d to %d)", reg1, reg2);
 336
 337                         if (parm & SUB32)
 338                                 reg1 = 32 - (int)eval;
 339                         else if (type == RI_NUM_32)
 340                                 reg1 = (reg1 == 32 ? 0 : (int)eval);
 341                         else
 342                                 reg1 = (int)eval;
 343                 }
 344
 345                 CHECK_COMMA;
 346                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 347                 ErrorIfNotAtEOL();
 348                 DepositRISCInstructionWord(parm, reg1, reg2);
 349                 break;
 350
 351         // Move Immediate--n,Rn--n in Second Word
 352         case RI_MOVEI:
 353                 if (*tok != '#')
 354                         return MalformedOpcode(MALF_NUM);
 355
 356                 tok++;
 357                 riscImmTokenSeen = 1;
 358
 359                 // Check for equated register after # and return error if so
 360                 if (*tok == SYMBOL)
 361                 {
 362                         sy = lookup(string[tok[1]], LABEL, 0);
 363
 364                         if (sy && (sy->sattre & EQUATEDREG))
 365                                 return error("equated register in 1st operand of MOVEI instruction");
 366                 }
 367
 368                 if (expr(r_expr, &eval, &eattr, &esym) != OK)
 369                         return MalformedOpcode(MALF_EXPR);
 370
 371                 if ((lastOpcode == RI_JUMP) || (lastOpcode == RI_JR))
 372                 {
 373                         if (legacy_flag)
 374                         {
 375                                 // User doesn't care, emit a NOP to fix
 376                                 DepositRISCInstructionWord(57, 0, 0);
 377                                 warn("MOVEI following JUMP, inserting NOP to fix your BROKEN CODE");
 378                         }
 379                         else
 380                                 warn("MOVEI immediately follows JUMP");
 381                 }
 382
 383                 if (!(eattr & DEFINED))
 384                 {
 385                         AddFixup(FU_LONG | FU_MOVEI, sloc + 2, r_expr);
 386                         eval = 0;
 387                 }
 388                 else
 389                 {
 390                         if (eattr & TDB)
 391                                 MarkRelocatable(cursect, sloc + 2, (eattr & TDB), (MLONG | MMOVEI), NULL);
 392                 }
 393
 394                 CHECK_COMMA;
 395                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 396                 ErrorIfNotAtEOL();
 397
 398                 DepositRISCInstructionWord(parm, 0, reg2);
 399                 val = WORDSWAP32(eval);
 400                 D_long(val);
 401                 break;
 402
 403         // PC,Rd or Rs,Rd
 404         case RI_MOVE:
 405                 if (*tok == KW_PC)
 406                 {
 407                         parm = 51;
 408                         reg1 = 0;
 409                         tok++;
 410                 }
 411                 else
 412                 {
 413                         parm = 34;
 414                         reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 415                 }
 416
 417                 CHECK_COMMA;
 418                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 419                 ErrorIfNotAtEOL();
 420                 DepositRISCInstructionWord(parm, reg1, reg2);
 421                 break;
 422
 423         // (Rn),Rn = 41 / (R14/R15+n),Rn = 43/44 / (R14/R15+Rn),Rn = 58/59
 424         case RI_LOAD:
 425                 indexed = 0;
 426                 parm = 41;
 427
 428                 if (*tok != '(')
 429                         return MalformedOpcode(MALF_LPAREN);
 430
 431                 tok++;
 432
 433         if ((tok[1] == '+') || (tok[1] == '-'))
 434                 {
 435                         // Trying to make indexed call
 436                         if ((*tok == KW_R14) || (*tok == KW_R15))
 437                                 indexed = (*tok - KW_R0);
 438                         else
 439                                 return IllegalIndexedRegister(*tok);
 440                 }
 441
 442                 if (*tok == SYMBOL)
 443                 {
 444                         sy = lookup(string[tok[1]], LABEL, 0);
 445
 446                         if (!sy)
 447                         {
 448                                 error(reg_err);
 449                                 return ERROR;
 450                         }
 451
 452                         if (sy->sattre & EQUATEDREG)
 453                         {
 454                                 if ((tok[2] == '+') || (tok[2] == '-'))
 455                                 {
 456                                         if ((sy->svalue & 0x1F) == 14 || (sy->svalue & 0x1F) == 15) {
 457                                                 indexed = (sy->svalue & 0x1F);
 458                                                 tok++;
 459                                         }
 460                                         else
 461                                                 return IllegalIndexedRegisterEqur(sy);
 462                                 }
 463                         }
 464                 }
 465
 466                 if (!indexed)
 467                 {
 468                         reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 469                 }
 470                 else
 471                 {
 472                         reg1 = indexed;
 473                         indexed = 0;
 474                         tok++;
 475
 476                         if (*tok == '+')
 477                         {
 478                                 parm = (WORD)(reg1 - 14 + 58);
 479                                 tok++;
 480
 481                                 if ((*tok >= KW_R0) && (*tok <= KW_R31))
 482                                         indexed = 1;
 483
 484                                 if (*tok == SYMBOL)
 485                                 {
 486                                         sy = lookup(string[tok[1]], LABEL, 0);
 487
 488                                         if (!sy)
 489                                         {
 490                                                 error(reg_err);
 491                                                 return ERROR;
 492                                         }
 493
 494                                         if (sy->sattre & EQUATEDREG)
 495                                                 indexed = 1;
 496                                 }
 497
 498                                 if (indexed)
 499                                 {
 500                                         reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 501                                 }
 502                                 else
 503                                 {
 504                                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 505                                                 return MalformedOpcode(MALF_EXPR);
 506
 507                                         if (!(eattr & DEFINED))
 508                                                 return error("constant expected after '+'");
 509
 510                                         reg1 = (int)eval;
 511
 512                                         if (reg1 == 0)
 513                                         {
 514                                                 reg1 = 14 + (parm - 58);
 515                                                 parm = 41;
 516                                                 warn("NULL offset in LOAD ignored");
 517                                         }
 518                                         else
 519                                         {
 520                                                 if ((reg1 < 1) || (reg1 > 32))
 521                                                         return error("constant in LOAD out of range (1-32)");
 522
 523                                                 if (reg1 == 32)
 524                                                         reg1 = 0;
 525
 526                                                 parm = (WORD)(parm - 58 + 43);
 527                                         }
 528                                 }
 529                         }
 530                         else
 531                         {
 532                                 reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 533                         }
 534                 }
 535
 536                 if (*tok != ')')
 537                         return MalformedOpcode(MALF_RPAREN);
 538
 539                 tok++;
 540                 CHECK_COMMA;
 541                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 542                 ErrorIfNotAtEOL();
 543                 DepositRISCInstructionWord(parm, reg1, reg2);
 544                 break;
 545
 546         // Rn,(Rn) = 47 / Rn,(R14/R15+n) = 49/50 / Rn,(R14/R15+Rn) = 60/61
 547         case RI_STORE:
 548                 parm = 47;
 549                 reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 550                 CHECK_COMMA;
 551
 552                 if (*tok != '(')
 553                         return MalformedOpcode(MALF_LPAREN);
 554
 555                 tok++;
 556                 indexed = 0;
 557
 558                 if (((*tok == KW_R14) || (*tok == KW_R15)) && (tok[1] != ')'))
 559                         indexed = *tok - KW_R0;
 560
 561                 if (*tok == SYMBOL)
 562                 {
 563                         sy = lookup(string[tok[1]], LABEL, 0);
 564
 565                         if (!sy)
 566                         {
 567                                 error(reg_err);
 568                                 return ERROR;
 569                         }
 570
 571                         if (sy->sattre & EQUATEDREG)
 572                         {
 573                                 if (((sy->svalue & 0x1F) == 14 || (sy->svalue & 0x1F) == 15)
 574                                         && (tok[2] != ')'))
 575                                 {
 576                                         indexed = (sy->svalue & 0x1F);
 577                                         tok++;
 578                                 }
 579                         }
 580                 }
 581
 582                 if (!indexed)
 583                 {
 584                         reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 585                 }
 586                 else
 587                 {
 588                         reg2 = indexed;
 589                         indexed = 0;
 590                         tok++;
 591
 592                         if (*tok == '+')
 593                         {
 594                                 parm = (WORD)(reg2 - 14 + 60);
 595                                 tok++;
 596
 597                                 if ((*tok >= KW_R0) && (*tok <= KW_R31))
 598                                         indexed = 1;
 599
 600                                 if (*tok == SYMBOL)
 601                                 {
 602                                         sy = lookup(string[tok[1]], LABEL, 0);
 603
 604                                         if (!sy)
 605                                         {
 606                                                 error(reg_err);
 607                                                 return ERROR;
 608                                         }
 609
 610                                         if (sy->sattre & EQUATEDREG)
 611                                                 indexed = 1;
 612                                 }
 613
 614                                 if (indexed)
 615                                 {
 616                                         reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 617                                 }
 618                                 else
 619                                 {
 620                                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 621                                                 return MalformedOpcode(MALF_EXPR);
 622
 623                                         if (!(eattr & DEFINED))
 624                                         {
 625                                                 AddFixup(FU_WORD | FU_REGTWO, sloc, r_expr);
 626                                                 reg2 = 0;
 627                                         }
 628                                         else
 629                                         {
 630                                                 reg2 = (int)eval;
 631
 632                                                 if (reg2 == 0)
 633                                                 {
 634                                                         reg2 = 14 + (parm - 60);
 635                                                         parm = 47;
 636                                                         warn("NULL offset in STORE ignored");
 637                                                 }
 638                                                 else
 639                                                 {
 640                                                         if ((reg2 < 1) || (reg2 > 32))
 641                                                                 return error("constant in STORE out of range (1-32)");
 642
 643                                                         if (reg2 == 32)
 644                                                                 reg2 = 0;
 645
 646                                                         parm = (WORD)(parm - 60 + 49);
 647                                                 }
 648                                         }
 649                                 }
 650                         }
 651                         else
 652                         {
 653                                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 654                         }
 655                 }
 656
 657                 if (*tok != ')')
 658                         return MalformedOpcode(MALF_RPAREN);
 659
 660                 tok++;
 661                 ErrorIfNotAtEOL();
 662                 DepositRISCInstructionWord(parm, reg2, reg1);
 663                 break;
 664
 665         // LOADB/LOADP/LOADW (Rn),Rn
 666         case RI_LOADN:
 667                 if (*tok != '(')
 668                         return MalformedOpcode(MALF_LPAREN);
 669
 670                 tok++;
 671                 reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 672
 673                 if (*tok != ')')
 674                         return MalformedOpcode(MALF_RPAREN);
 675
 676                 tok++;
 677                 CHECK_COMMA;
 678                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 679                 ErrorIfNotAtEOL();
 680                 DepositRISCInstructionWord(parm, reg1, reg2);
 681                 break;
 682
 683         // STOREB/STOREP/STOREW Rn,(Rn)
 684         case RI_STOREN:
 685                 reg1 = EvaluateRegisterFromTokenStream(FU_REGONE);
 686                 CHECK_COMMA;
 687
 688                 if (*tok != '(')
 689                         return MalformedOpcode(MALF_LPAREN);
 690
 691                 tok++;
 692                 reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 693
 694                 if (*tok != ')')
 695                         return MalformedOpcode(MALF_RPAREN);
 696
 697                 tok++;
 698                 ErrorIfNotAtEOL();
 699                 DepositRISCInstructionWord(parm, reg2, reg1);
 700                 break;
 701
 702         // Jump Relative - cc,n - n=-16..+15 words, reg2=cc
 703         case RI_JR:
 704
 705         // Jump Absolute - cc,(Rs) - reg2=cc
 706         case RI_JUMP:
 707                 // Check to see if there is a comma in the token string. If not then
 708                 // the JR or JUMP should default to 0, Jump Always
 709                 commaFound = 0;
 710
 711                 for(t=tok; *t!=EOL; t++)
 712                 {
 713                         if (*t == ',')
 714                         {
 715                                 commaFound = 1;
 716                                 break;
 717                         }
 718                 }
 719
 720                 if (commaFound)
 721                 {
 722                         if (*tok == CONST)
 723                         {
 724                                 // CC using a constant number (O_o)
 725                                 PTR tp;
 726                                 tp.tk = tok + 1;
 727                                 val = *tp.i64++;
 728                                 tok = tp.tk;
 729                                 CHECK_COMMA;
 730                         }
 731                         else if (*tok == SYMBOL)
 732                         {
 733                                 val = 9999;
 734                                 strcpy(scratch, string[tok[1]]);
 735                                 strtoupper(scratch);
 736
 737                                 for(i=0; i<MAXINTERNCC; i++)
 738                                 {
 739                                         // Look for the condition code & break if found
 740                                         if (strcmp(condname[i], scratch) == 0)
 741                                         {
 742                                                 val = condnumber[i];
 743                                                 break;
 744                                         }
 745                                 }
 746
 747                                 // Standard CC was not found, look for an equated one
 748                                 if (val == 9999)
 749                                 {
 750                                         ccsym = lookup(string[tok[1]], LABEL, 0);
 751
 752                                         if (ccsym && (ccsym->sattre & EQUATEDCC) && !(ccsym->sattre & UNDEF_CC))
 753                                                 val = (int)ccsym->svalue;
 754                                         else
 755                                                 return error("unknown condition code");
 756                                 }
 757
 758                                 tok += 2;
 759                                 CHECK_COMMA;
 760                         }
 761                         else if (*tok == '(')
 762                         {
 763                                 // Set CC to "Jump Always"
 764                                 val = 0;
 765                         }
 766                 }
 767                 else
 768                 {
 769                         // Set CC to "Jump Always"
 770                         val = 0;
 771                 }
 772
 773                 if ((val < 0) || (val > 31))
 774                         return error("condition constant out of range");
 775
 776                 // Store condition code
 777                 reg1 = val;
 778
 779                 if (type == RI_JR)
 780                 {
 781                         // JR cc,n
 782                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 783                                 return MalformedOpcode(MALF_EXPR);
 784
 785                         if (!(eattr & DEFINED))
 786                         {
 787                                 AddFixup(FU_WORD | FU_JR, sloc, r_expr);
 788                                 reg2 = 0;
 789                         }
 790                         else
 791                         {
 792                                 reg2 = ((int)(eval - ((orgactive ? orgaddr : sloc) + 2))) / 2;
 793
 794                                 if ((reg2 < -16) || (reg2 > 15))
 795                                         error("PC relative overflow in JR (outside of -16 to 15)");
 796                         }
 797                 }
 798                 else
 799                 {
 800                         // JUMP cc, (Rn)
 801                         if (*tok != '(')
 802                                 return MalformedOpcode(MALF_LPAREN);
 803
 804                         tok++;
 805                         reg2 = EvaluateRegisterFromTokenStream(FU_REGTWO);
 806
 807                         if (*tok != ')')
 808                                 return MalformedOpcode(MALF_RPAREN);
 809
 810                         tok++;
 811                         ErrorIfNotAtEOL();
 812                 }
 813
 814                 DepositRISCInstructionWord(parm, reg2, reg1);
 815                 break;
 816
 817         // We should never get here. If we do, somebody done fucked up. :-D
 818         default:
 819                 return error("Unknown RISC opcode type");
 820         }
 821
 822         lastOpcode = type;
 823         return 0;
 824 }
 825