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

   1 //
   2 // RMAC - Renamed Macro Assembler for all Atari computers
   3 // RISCA.C - GPU/DSP Assembler
   4 // Copyright (C) 199x Landon Dyer, 2011-2021 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 // Useful macros
  29 #define EVAL_REG_RETURN_IF_ERROR(x, y) \
  30 x = EvaluateRegisterFromTokenStream(y); \
  31 \
  32 if (x == ERROR) \
  33         return ERROR;
  34
  35 #define EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(x, y) \
  36 x = EvaluateRegisterFromTokenStream(y); \
  37 \
  38 if ((x == ERROR) || (ErrorIfNotAtEOL() == ERROR)) \
  39         return ERROR;
  40
  41 #define CHECK_EOL \
  42 if (ErrorIfNotAtEOL() == ERROR) \
  43         return ERROR;
  44
  45 unsigned altbankok = 0;         // Ok to use alternate register bank
  46 unsigned orgactive = 0;         // RISC/6502 org directive active
  47 unsigned orgaddr = 0;           // Org'd address
  48 unsigned orgwarning = 0;        // Has an ORG warning been issued
  49 int lastOpcode = -1;            // Last RISC opcode assembled
  50 uint8_t riscImmTokenSeen;       // The '#' (immediate) token was seen
  51
  52 static const char reg_err[] = "missing register R0...R31";
  53
  54 // Jaguar jump condition names
  55 static const char condname[MAXINTERNCC][5] = {
  56         "NZ", "Z", "NC", "NCNZ", "NCZ", "C", "CNZ", "CZ", "NN", "NNNZ", "NNZ",
  57         "N", "N_NZ", "N_Z", "T", "A", "NE", "EQ", "CC", "HS", "HI", "CS", "LO",
  58         "PL", "MI", "F"
  59 };
  60
  61 // Jaguar jump condition numbers
  62 static const char condnumber[] = {
  63         1, 2, 4, 5, 6, 8, 9, 10, 20, 21, 22, 24, 25, 26,
  64         0, 0, 1, 2, 4, 4, 5,  8,  8, 20, 24, 31
  65 };
  66
  67 // Opcode Specific Data
  68 struct opcoderecord {
  69         uint16_t state;         // Opcode Name (unused)
  70         uint16_t type;          // Opcode Type
  71         uint16_t param;         // Opcode Parameter
  72 };
  73
  74 static const struct opcoderecord roptbl[] = {
  75         { MR_ADD,     RI_TWO,    0 },
  76         { MR_ADDC,    RI_TWO,    1 },
  77         { MR_ADDQ,    RI_NUM_32, 2 },
  78         { MR_ADDQT,   RI_NUM_32, 3 },
  79         { MR_SUB,     RI_TWO,    4 },
  80         { MR_SUBC,    RI_TWO,    5 },
  81         { MR_SUBQ,    RI_NUM_32, 6 },
  82         { MR_SUBQT,   RI_NUM_32, 7 },
  83         { MR_NEG,     RI_ONE,    8 },
  84         { MR_AND,     RI_TWO,    9 },
  85         { MR_OR,      RI_TWO,    10 },
  86         { MR_XOR,     RI_TWO,    11 },
  87         { MR_NOT,     RI_ONE,    12 },
  88         { MR_BTST,    RI_NUM_31, 13 },
  89         { MR_BSET,    RI_NUM_31, 14 },
  90         { MR_BCLR,    RI_NUM_31, 15 },
  91         { MR_MULT,    RI_TWO,    16 },
  92         { MR_IMULT,   RI_TWO,    17 },
  93         { MR_IMULTN,  RI_TWO,    18 },
  94         { MR_RESMAC,  RI_ONE,    19 },
  95         { MR_IMACN,   RI_TWO,    20 },
  96         { MR_DIV,     RI_TWO,    21 },
  97         { MR_ABS,     RI_ONE,    22 },
  98         { MR_SH,      RI_TWO,    23 },
  99         { MR_SHLQ,    RI_NUM_32, 24 + SUB32 },
 100         { MR_SHRQ,    RI_NUM_32, 25 },
 101         { MR_SHA,     RI_TWO,    26 },
 102         { MR_SHARQ,   RI_NUM_32, 27 },
 103         { MR_ROR,     RI_TWO,    28 },
 104         { MR_RORQ,    RI_NUM_32, 29 },
 105         { MR_ROLQ,    RI_NUM_32, 29 + SUB32 },
 106         { MR_CMP,     RI_TWO,    30 },
 107         { MR_CMPQ,    RI_NUM_15, 31 },
 108         { MR_SAT8,    RI_ONE,    32 + GPUONLY },
 109         { MR_SUBQMOD, RI_NUM_32, 32 + DSPONLY },
 110         { MR_SAT16,   RI_ONE,    33 + GPUONLY },
 111         { MR_SAT16S,  RI_ONE,    33 + DSPONLY },
 112         { MR_MOVEQ,   RI_NUM_31, 35 },
 113         { MR_MOVETA,  RI_TWO,    36 },
 114         { MR_MOVEFA,  RI_TWO,    37 },
 115         { MR_MOVEI,   RI_MOVEI,  38 },
 116         { MR_LOADB,   RI_LOADN,  39 },
 117         { MR_LOADW,   RI_LOADN,  40 },
 118         { MR_LOADP,   RI_LOADN,  42 + GPUONLY },
 119         { MR_SAT32S,  RI_ONE,    42 + DSPONLY },
 120         { MR_STOREB,  RI_STOREN, 45 },
 121         { MR_STOREW,  RI_STOREN, 46 },
 122         { MR_STOREP,  RI_STOREN, 48 + GPUONLY },
 123         { MR_MIRROR,  RI_ONE,    48 + DSPONLY },
 124         { MR_JUMP,    RI_JUMP,   52 },
 125         { MR_JR,      RI_JR,     53 },
 126         { MR_MMULT,   RI_TWO,    54 },
 127         { MR_MTOI,    RI_TWO,    55 },
 128         { MR_NORMI,   RI_TWO,    56 },
 129         { MR_NOP,     RI_NONE,   57 },
 130         { MR_SAT24,   RI_ONE,    62 },
 131         { MR_UNPACK,  RI_ONE,    63 + GPUONLY | (0 << 6) },
 132         { MR_PACK,    RI_ONE,    63 + GPUONLY | (1 << 6) },
 133         { MR_ADDQMOD, RI_NUM_32, 63 + DSPONLY },
 134         { MR_MOVE,    RI_MOVE,   0 },
 135         { MR_LOAD,    RI_LOAD,   0 },
 136         { MR_STORE,   RI_STORE,  0 }
 137 };
 138
 139 #define MALF_NUM                0
 140 #define MALF_EXPR               1
 141 #define MALF_LPAREN             2
 142 #define MALF_RPAREN             3
 143
 144 static const char malform1[] = "missing '#'";
 145 static const char malform2[] = "bad expression";
 146 static const char malform3[] = "missing ')'";
 147 static const char malform4[] = "missing '('";
 148
 149 static const char * malformErr[] = {
 150         malform1, malform2, malform3, malform4
 151 };
 152
 153 //
 154 // Function to return "malformed expression" error
 155 // This is done mainly to remove a bunch of GOTO statements in the parser
 156 //
 157 static inline int MalformedOpcode(int signal)
 158 {
 159         return error("Malformed opcode, %s", malformErr[signal]);
 160 }
 161
 162 //
 163 // Function to return "Illegal Indexed Register" error
 164 // Anyone trying to index something other than R14 or R15
 165 //
 166 static inline int IllegalIndexedRegister(int reg)
 167 {
 168         return error("Attempted index reference with non-indexable register (r%d)", reg - KW_R0);
 169 }
 170
 171 //
 172 // Function to return "Illegal Indexed Register" error for EQUR scenarios
 173 // Trying to use register value within EQUR that isn't 14 or 15
 174 //
 175 static inline int IllegalIndexedRegisterEqur(SYM * sy)
 176 {
 177         return error("Attempted index reference with non-indexable register within EQUR (%s = r%d)", sy->sname, sy->svalue);
 178 }
 179
 180 //
 181 // Build up & deposit RISC instruction word
 182 //
 183 static void DepositRISCInstructionWord(uint16_t opcode, int reg1, int reg2)
 184 {
 185         // Check for absolute address setting
 186         if (!orgwarning && !orgactive)
 187         {
 188                 warn("RISC code generated with no origin defined");
 189                 orgwarning = 1;
 190         }
 191
 192         int value = ((opcode & 0x3F) << 10) + ((reg1 & 0x1F) << 5) + (reg2 & 0x1F);
 193         D_word(value);
 194 }
 195
 196 //
 197 // Evaluate the RISC register from the token stream. Passed in value is the
 198 // FIXUP attribute to use if the expression comes back as undefined.
 199 //
 200 static int EvaluateRegisterFromTokenStream(uint32_t fixup)
 201 {
 202         // Firstly, check to see if it's a register token and return that.  No
 203         // need to invoke expr() for easy cases like this.
 204         if (*tok >= KW_R0 && *tok <= KW_R31)
 205         {
 206                 int reg = *tok - KW_R0;
 207                 tok++;
 208                 return reg;
 209         }
 210
 211         if (*tok != SYMBOL)
 212         {
 213                 // If at this point we don't have a symbol then it's garbage.  Punt.
 214                 return error("Expected register number or EQUREG");
 215         }
 216
 217         uint64_t eval;                          // Expression value
 218         WORD eattr;                                     // Expression attributes
 219         SYM * esym;                                     // External symbol involved in expr.
 220         TOKEN r_expr[EXPRSIZE];         // Expression token list
 221
 222         // Evaluate what's in the global "tok" buffer
 223         // N.B.: We should either get a fixup or a register name from EQUR
 224         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 225                 return ERROR;
 226
 227         if (!(eattr & DEFINED))
 228         {
 229                 AddFixup(FU_WORD | fixup, sloc, r_expr);
 230                 return 0;
 231         }
 232
 233         // If we got a register in range (0-31), return it
 234         if (eval <= 31)
 235                 return (int)eval;
 236
 237         // Otherwise, it's out of range & we flag an error
 238         return error(reg_err);
 239 }
 240
 241 //
 242 // Do RISC code generation
 243 //
 244 int GenerateRISCCode(int state)
 245 {
 246         int reg1;                                       // Register 1
 247         int reg2;                                       // Register 2
 248         int val = 0;                            // Constructed value
 249         char scratch[80];
 250         SYM * ccsym;
 251         SYM * sy;
 252         int i, commaFound;
 253         TOKEN * t;
 254         uint16_t attrflg;
 255         int indexed;                            // Indexed register flag
 256
 257         uint64_t eval;                          // Expression value
 258         uint16_t eattr;                         // Expression attributes
 259         SYM * esym = NULL;                      // External symbol involved in expr.
 260         TOKEN r_expr[EXPRSIZE];         // Expression token list
 261
 262         // Get opcode parameter and type
 263         uint16_t parm = roptbl[state - 3000].param;
 264         uint16_t type = roptbl[state - 3000].type;
 265         riscImmTokenSeen = 0;           // Set to "token not seen yet"
 266
 267         // Detect whether the opcode parmeter passed determines that the opcode is
 268         // specific to only one of the RISC processors and ensure it is legal in
 269         // the current code section. If not then show error and return.
 270         if (((parm & GPUONLY) && rdsp) || ((parm & DSPONLY) && rgpu))
 271                 return error("Opcode is not valid in this code section");
 272
 273         // Process RISC opcode
 274         switch (type)
 275         {
 276         // No operand instructions
 277         // NOP (57)
 278         case RI_NONE:
 279                 DepositRISCInstructionWord(parm, 0, 0);
 280                 break;
 281
 282         // Single operand instructions (Rd)
 283         // ABS, MIRROR, NEG, NOT, PACK, RESMAC, SAT8, SAT16, SAT16S, SAT24, SAT32S,
 284         // UNPACK
 285         case RI_ONE:
 286                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 287                 DepositRISCInstructionWord(parm, parm >> 6, reg2);
 288                 break;
 289
 290         // Two operand instructions (Rs,Rd)
 291         // ADD, ADDC, AND, CMP, DIV, IMACN, IMULT, IMULTN, MOVEFA, MOVETA, MULT,
 292         // MMULT, MTOI, NORMI, OR, ROR, SH, SHA, SUB, SUBC, XOR
 293         case RI_TWO:
 294                 if (parm == 37)
 295                         altbankok = 1;                      // MOVEFA
 296
 297                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 298                 CHECK_COMMA;
 299
 300                 if (parm == 36)
 301                         altbankok = 1;                      // MOVETA
 302
 303                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 304                 DepositRISCInstructionWord(parm, reg1, reg2);
 305                 break;
 306
 307         // Numeric operand (n,Rd) where n = -16..+15
 308         // CMPQ
 309         case RI_NUM_15:
 310
 311         // Numeric operand (n,Rd) where n = 0..31
 312         // BCLR, BSET, BTST, MOVEQ
 313         case RI_NUM_31:
 314
 315         // Numeric operand (n,Rd) where n = 1..32
 316         // ADDQ, ADDQMOD, ADDQT, SHARQ, SHLQ, SHRQ, SUBQ, SUBQMOD, SUBQT, ROLQ,
 317         // RORQ
 318         case RI_NUM_32:
 319                 switch (type)
 320                 {
 321                 case RI_NUM_15:
 322                         reg1 = -16; reg2 = 15; attrflg = FU_NUM15;
 323                         break;
 324                 default:
 325                 case RI_NUM_31:
 326                         reg1 =   0; reg2 = 31; attrflg = FU_NUM31;
 327                         break;
 328                 case RI_NUM_32:
 329                         reg1 =   1; reg2 = 32; attrflg = FU_NUM32;
 330                         break;
 331                 }
 332
 333                 if (parm & SUB32)
 334                         attrflg |= FU_SUB32;
 335
 336                 if (*tok != '#')
 337                         return MalformedOpcode(MALF_NUM);
 338
 339                 tok++;
 340                 riscImmTokenSeen = 1;
 341
 342                 if (expr(r_expr, &eval, &eattr, &esym) != OK)
 343                         return MalformedOpcode(MALF_EXPR);
 344
 345                 if (!(eattr & DEFINED))
 346                 {
 347                         AddFixup((WORD)(FU_WORD | attrflg), sloc, r_expr);
 348                         reg1 = 0;
 349                 }
 350                 else
 351                 {
 352                         if (esym && (esym->sattre & EQUATEDREG))
 353                                 return error("equated register seen for immediate value");
 354
 355                         if (eattr & RISCREG)
 356                                 return error("register seen for immediate value");
 357
 358                         if (((int)eval < reg1) || ((int)eval > reg2))
 359                                 return error("constant out of range (%d to %d)", reg1, reg2);
 360
 361                         if (parm & SUB32)
 362                                 reg1 = 32 - (int)eval;
 363                         else if (type == RI_NUM_32)
 364                                 reg1 = (reg1 == 32 ? 0 : (int)eval);
 365                         else
 366                                 reg1 = (int)eval;
 367                 }
 368
 369                 CHECK_COMMA;
 370                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 371                 DepositRISCInstructionWord(parm, reg1, reg2);
 372                 break;
 373
 374         // Move Immediate--n,Rn--n in Second Word
 375         case RI_MOVEI:
 376                 if (*tok != '#')
 377                         return MalformedOpcode(MALF_NUM);
 378
 379                 tok++;
 380                 riscImmTokenSeen = 1;
 381
 382                 // Check for equated register after # and return error if so
 383                 if (*tok == SYMBOL)
 384                 {
 385                         sy = lookup(string[tok[1]], LABEL, 0);
 386
 387                         if (sy && (sy->sattre & EQUATEDREG))
 388                                 return error("equated register in 1st operand of MOVEI instruction");
 389                 }
 390
 391                 if (expr(r_expr, &eval, &eattr, &esym) != OK)
 392                         return MalformedOpcode(MALF_EXPR);
 393
 394                 if ((lastOpcode == RI_JUMP) || (lastOpcode == RI_JR))
 395                 {
 396                         if (legacy_flag)
 397                         {
 398                                 // User doesn't care, emit a NOP to fix
 399                                 DepositRISCInstructionWord(57, 0, 0);
 400                                 warn("MOVEI following JUMP, inserting NOP to fix your BROKEN CODE");
 401                         }
 402                         else
 403                                 warn("MOVEI immediately follows JUMP");
 404                 }
 405
 406                 if (!(eattr & DEFINED))
 407                 {
 408                         AddFixup(FU_LONG | FU_MOVEI, sloc + 2, r_expr);
 409                         eval = 0;
 410                 }
 411                 else
 412                 {
 413                         if (eattr & TDB)
 414                                 MarkRelocatable(cursect, sloc + 2, (eattr & TDB), (MLONG | MMOVEI), NULL);
 415                 }
 416
 417                 CHECK_COMMA;
 418                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 419
 420                 DepositRISCInstructionWord(parm, 0, reg2);
 421                 val = WORDSWAP32(eval);
 422                 D_long(val);
 423                 break;
 424
 425         // PC,Rd or Rs,Rd
 426         case RI_MOVE:
 427                 if (*tok == KW_PC)
 428                 {
 429                         parm = 51;
 430                         reg1 = 0;
 431                         tok++;
 432                 }
 433                 else
 434                 {
 435                         parm = 34;
 436                         EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 437                 }
 438
 439                 CHECK_COMMA;
 440                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 441                 DepositRISCInstructionWord(parm, reg1, reg2);
 442                 break;
 443
 444         // (Rn),Rn = 41 / (R14/R15+n),Rn = 43/44 / (R14/R15+Rn),Rn = 58/59
 445         case RI_LOAD:
 446                 indexed = 0;
 447                 parm = 41;
 448
 449                 if (*tok != '(')
 450                         return MalformedOpcode(MALF_LPAREN);
 451
 452                 tok++;
 453
 454         if ((tok[1] == '+') || (tok[1] == '-'))
 455                 {
 456                         // Trying to make indexed call
 457                         if ((*tok == KW_R14) || (*tok == KW_R15))
 458                                 indexed = (*tok - KW_R0);
 459                         else
 460                                 return IllegalIndexedRegister(*tok);
 461                 }
 462
 463                 if (*tok == SYMBOL)
 464                 {
 465                         sy = lookup(string[tok[1]], LABEL, 0);
 466
 467                         if (!sy)
 468                         {
 469                                 error(reg_err);
 470                                 return ERROR;
 471                         }
 472
 473                         if (sy->sattre & EQUATEDREG)
 474                         {
 475                                 if ((tok[2] == '+') || (tok[2] == '-'))
 476                                 {
 477                                         if ((sy->svalue & 0x1F) == 14 || (sy->svalue & 0x1F) == 15) {
 478                                                 indexed = (sy->svalue & 0x1F);
 479                                                 tok++;
 480                                         }
 481                                         else
 482                                                 return IllegalIndexedRegisterEqur(sy);
 483                                 }
 484                         }
 485                 }
 486
 487                 if (!indexed)
 488                 {
 489                         EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 490                 }
 491                 else
 492                 {
 493                         reg1 = indexed;
 494                         indexed = 0;
 495                         tok++;
 496
 497                         if (*tok == '+')
 498                         {
 499                                 parm = (WORD)(reg1 - 14 + 58);
 500                                 tok++;
 501
 502                                 if ((*tok >= KW_R0) && (*tok <= KW_R31))
 503                                         indexed = 1;
 504
 505                                 if (*tok == SYMBOL)
 506                                 {
 507                                         sy = lookup(string[tok[1]], LABEL, 0);
 508
 509                                         if (!sy)
 510                                         {
 511                                                 error(reg_err);
 512                                                 return ERROR;
 513                                         }
 514
 515                                         if (sy->sattre & EQUATEDREG)
 516                                                 indexed = 1;
 517                                 }
 518
 519                                 if (indexed)
 520                                 {
 521                                         EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 522                                 }
 523                                 else
 524                                 {
 525                                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 526                                                 return MalformedOpcode(MALF_EXPR);
 527
 528                                         if (!(eattr & DEFINED))
 529                                                 return error("constant expected after '+'");
 530
 531                                         reg1 = (int)eval;
 532
 533                                         if (reg1 == 0)
 534                                         {
 535                                                 reg1 = 14 + (parm - 58);
 536                                                 parm = 41;
 537                                                 warn("NULL offset in LOAD ignored");
 538                                         }
 539                                         else
 540                                         {
 541                                                 if ((reg1 < 1) || (reg1 > 32))
 542                                                         return error("constant in LOAD out of range (1-32)");
 543
 544                                                 if (reg1 == 32)
 545                                                         reg1 = 0;
 546
 547                                                 parm = (WORD)(parm - 58 + 43);
 548                                         }
 549                                 }
 550                         }
 551                         else
 552                         {
 553                                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 554                         }
 555                 }
 556
 557                 if (*tok != ')')
 558                         return MalformedOpcode(MALF_RPAREN);
 559
 560                 tok++;
 561                 CHECK_COMMA;
 562                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 563                 DepositRISCInstructionWord(parm, reg1, reg2);
 564                 break;
 565
 566         // Rn,(Rn) = 47 / Rn,(R14/R15+n) = 49/50 / Rn,(R14/R15+Rn) = 60/61
 567         case RI_STORE:
 568                 parm = 47;
 569                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 570                 CHECK_COMMA;
 571
 572                 if (*tok != '(')
 573                         return MalformedOpcode(MALF_LPAREN);
 574
 575                 tok++;
 576                 indexed = 0;
 577
 578                 if (((*tok == KW_R14) || (*tok == KW_R15)) && (tok[1] != ')'))
 579                         indexed = *tok - KW_R0;
 580
 581                 if (*tok == SYMBOL)
 582                 {
 583                         sy = lookup(string[tok[1]], LABEL, 0);
 584
 585                         if (!sy)
 586                         {
 587                                 error(reg_err);
 588                                 return ERROR;
 589                         }
 590
 591                         if (sy->sattre & EQUATEDREG)
 592                         {
 593                                 if (((sy->svalue & 0x1F) == 14 || (sy->svalue & 0x1F) == 15)
 594                                         && (tok[2] != ')'))
 595                                 {
 596                                         indexed = (sy->svalue & 0x1F);
 597                                         tok++;
 598                                 }
 599                         }
 600                 }
 601
 602                 if (!indexed)
 603                 {
 604                         EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 605                 }
 606                 else
 607                 {
 608                         reg2 = indexed;
 609                         indexed = 0;
 610                         tok++;
 611
 612                         if (*tok == '+')
 613                         {
 614                                 parm = (WORD)(reg2 - 14 + 60);
 615                                 tok++;
 616
 617                                 if ((*tok >= KW_R0) && (*tok <= KW_R31))
 618                                         indexed = 1;
 619
 620                                 if (*tok == SYMBOL)
 621                                 {
 622                                         sy = lookup(string[tok[1]], LABEL, 0);
 623
 624                                         if (!sy)
 625                                         {
 626                                                 error(reg_err);
 627                                                 return ERROR;
 628                                         }
 629
 630                                         if (sy->sattre & EQUATEDREG)
 631                                                 indexed = 1;
 632                                 }
 633
 634                                 if (indexed)
 635                                 {
 636                                         EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 637                                 }
 638                                 else
 639                                 {
 640                                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 641                                                 return MalformedOpcode(MALF_EXPR);
 642
 643                                         if (!(eattr & DEFINED))
 644                                         {
 645                                                 AddFixup(FU_WORD | FU_REGTWO, sloc, r_expr);
 646                                                 reg2 = 0;
 647                                         }
 648                                         else
 649                                         {
 650                                                 reg2 = (int)eval;
 651
 652                                                 if (reg2 == 0)
 653                                                 {
 654                                                         reg2 = 14 + (parm - 60);
 655                                                         parm = 47;
 656                                                         warn("NULL offset in STORE ignored");
 657                                                 }
 658                                                 else
 659                                                 {
 660                                                         if ((reg2 < 1) || (reg2 > 32))
 661                                                                 return error("constant in STORE out of range (1-32)");
 662
 663                                                         if (reg2 == 32)
 664                                                                 reg2 = 0;
 665
 666                                                         parm = (WORD)(parm - 60 + 49);
 667                                                 }
 668                                         }
 669                                 }
 670                         }
 671                         else
 672                         {
 673                                 EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 674                         }
 675                 }
 676
 677                 if (*tok != ')')
 678                         return MalformedOpcode(MALF_RPAREN);
 679
 680                 tok++;
 681                 CHECK_EOL;
 682                 DepositRISCInstructionWord(parm, reg2, reg1);
 683                 break;
 684
 685         // LOADB/LOADP/LOADW (Rn),Rn
 686         case RI_LOADN:
 687                 if (*tok != '(')
 688                         return MalformedOpcode(MALF_LPAREN);
 689
 690                 tok++;
 691                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 692
 693                 if (*tok != ')')
 694                         return MalformedOpcode(MALF_RPAREN);
 695
 696                 tok++;
 697                 CHECK_COMMA;
 698                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 699                 DepositRISCInstructionWord(parm, reg1, reg2);
 700                 break;
 701
 702         // STOREB/STOREP/STOREW Rn,(Rn)
 703         case RI_STOREN:
 704                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 705                 CHECK_COMMA;
 706
 707                 if (*tok != '(')
 708                         return MalformedOpcode(MALF_LPAREN);
 709
 710                 tok++;
 711                 EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 712
 713                 if (*tok != ')')
 714                         return MalformedOpcode(MALF_RPAREN);
 715
 716                 tok++;
 717                 CHECK_EOL;
 718                 DepositRISCInstructionWord(parm, reg2, reg1);
 719                 break;
 720
 721         // Jump Relative - cc,n - n=-16..+15 words, reg2=cc
 722         case RI_JR:
 723
 724         // Jump Absolute - cc,(Rs) - reg2=cc
 725         case RI_JUMP:
 726                 // Check to see if there is a comma in the token string. If not then
 727                 // the JR or JUMP should default to 0, Jump Always
 728                 commaFound = 0;
 729
 730                 for(t=tok; *t!=EOL; t++)
 731                 {
 732                         if (*t == ',')
 733                         {
 734                                 commaFound = 1;
 735                                 break;
 736                         }
 737                 }
 738
 739                 if (commaFound)
 740                 {
 741                         if (*tok == CONST)
 742                         {
 743                                 // CC using a constant number (O_o)
 744                                 PTR tp;
 745                                 tp.tk = tok + 1;
 746                                 val = *tp.i64++;
 747                                 tok = tp.tk;
 748                                 CHECK_COMMA;
 749                         }
 750                         else if (*tok == SYMBOL)
 751                         {
 752                                 val = 9999;
 753                                 strcpy(scratch, string[tok[1]]);
 754                                 strtoupper(scratch);
 755
 756                                 for(i=0; i<MAXINTERNCC; i++)
 757                                 {
 758                                         // Look for the condition code & break if found
 759                                         if (strcmp(condname[i], scratch) == 0)
 760                                         {
 761                                                 val = condnumber[i];
 762                                                 break;
 763                                         }
 764                                 }
 765
 766                                 // Standard CC was not found, look for an equated one
 767                                 if (val == 9999)
 768                                 {
 769                                         ccsym = lookup(string[tok[1]], LABEL, 0);
 770
 771                                         if (ccsym && (ccsym->sattre & EQUATEDCC) && !(ccsym->sattre & UNDEF_CC))
 772                                                 val = (int)ccsym->svalue;
 773                                         else
 774                                                 return error("unknown condition code");
 775                                 }
 776
 777                                 tok += 2;
 778                                 CHECK_COMMA;
 779                         }
 780                         else if (*tok == '(')
 781                         {
 782                                 // Set CC to "Jump Always"
 783                                 val = 0;
 784                         }
 785                 }
 786                 else
 787                 {
 788                         // Set CC to "Jump Always"
 789                         val = 0;
 790                 }
 791
 792                 if ((val < 0) || (val > 31))
 793                         return error("condition constant out of range");
 794
 795                 // Store condition code
 796                 reg1 = val;
 797
 798                 if (type == RI_JR)
 799                 {
 800                         // JR cc,n
 801                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 802                                 return MalformedOpcode(MALF_EXPR);
 803
 804                         if (!(eattr & DEFINED))
 805                         {
 806                                 AddFixup(FU_WORD | FU_JR, sloc, r_expr);
 807                                 reg2 = 0;
 808                         }
 809                         else
 810                         {
 811                                 reg2 = ((int)(eval - ((orgactive ? orgaddr : sloc) + 2))) / 2;
 812
 813                                 if ((reg2 < -16) || (reg2 > 15))
 814                                         error("PC relative overflow in JR (outside of -16 to 15)");
 815                         }
 816                 }
 817                 else
 818                 {
 819                         // JUMP cc, (Rn)
 820                         if (*tok != '(')
 821                                 return MalformedOpcode(MALF_LPAREN);
 822
 823                         tok++;
 824                         EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 825
 826                         if (*tok != ')')
 827                                 return MalformedOpcode(MALF_RPAREN);
 828
 829                         tok++;
 830                         CHECK_EOL;
 831                 }
 832
 833                 DepositRISCInstructionWord(parm, reg2, reg1);
 834                 break;
 835
 836         // We should never get here. If we do, somebody done fucked up. :-D
 837         default:
 838                 return error("Unknown RISC opcode type");
 839         }
 840
 841         lastOpcode = type;
 842         return 0;
 843 }