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         int reg = *tok & 255;
 205         if (reg >= KW_R0 && reg <= KW_R31)
 206         {
 207                 reg -= KW_R0;
 208                 tok++;
 209                 return reg;
 210         }
 211
 212         if (*tok != SYMBOL)
 213         {
 214                 // If at this point we don't have a symbol then it's garbage.  Punt.
 215                 return error("Expected register number or EQUREG");
 216         }
 217
 218         uint64_t eval;                          // Expression value
 219         WORD eattr;                                     // Expression attributes
 220         SYM * esym;                                     // External symbol involved in expr.
 221         TOKEN r_expr[EXPRSIZE];         // Expression token list
 222
 223         // Evaluate what's in the global "tok" buffer
 224         // N.B.: We should either get a fixup or a register name from EQUR
 225         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 226                 return ERROR;
 227
 228         if (!(eattr & DEFINED))
 229         {
 230                 AddFixup(FU_WORD | fixup, sloc, r_expr);
 231                 return 0;
 232         }
 233
 234         // We shouldn't get here, that should not be legal
 235         interror(9);
 236 }
 237
 238 //
 239 // Do RISC code generation
 240 //
 241 int GenerateRISCCode(int state)
 242 {
 243         int reg1;                                       // Register 1
 244         int reg2;                                       // Register 2
 245         int val = 0;                            // Constructed value
 246         char scratch[80];
 247         SYM * ccsym;
 248         SYM * sy;
 249         int i, commaFound;
 250         TOKEN * t;
 251         uint16_t attrflg;
 252         int indexed;                            // Indexed register flag
 253
 254         uint64_t eval;                          // Expression value
 255         uint16_t eattr;                         // Expression attributes
 256         SYM * esym = NULL;                      // External symbol involved in expr.
 257         TOKEN r_expr[EXPRSIZE];         // Expression token list
 258
 259         // Get opcode parameter and type
 260         uint16_t parm = roptbl[state - 3000].param;
 261         uint16_t type = roptbl[state - 3000].type;
 262         riscImmTokenSeen = 0;           // Set to "token not seen yet"
 263
 264         // Detect whether the opcode parmeter passed determines that the opcode is
 265         // specific to only one of the RISC processors and ensure it is legal in
 266         // the current code section. If not then show error and return.
 267         if (((parm & GPUONLY) && rdsp) || ((parm & DSPONLY) && rgpu))
 268                 return error("Opcode is not valid in this code section");
 269
 270         // Process RISC opcode
 271         switch (type)
 272         {
 273         // No operand instructions
 274         // NOP (57)
 275         case RI_NONE:
 276                 DepositRISCInstructionWord(parm, 0, 0);
 277                 break;
 278
 279         // Single operand instructions (Rd)
 280         // ABS, MIRROR, NEG, NOT, PACK, RESMAC, SAT8, SAT16, SAT16S, SAT24, SAT32S,
 281         // UNPACK
 282         case RI_ONE:
 283                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 284                 DepositRISCInstructionWord(parm, parm >> 6, reg2);
 285                 break;
 286
 287         // Two operand instructions (Rs,Rd)
 288         // ADD, ADDC, AND, CMP, DIV, IMACN, IMULT, IMULTN, MOVEFA, MOVETA, MULT,
 289         // MMULT, MTOI, NORMI, OR, ROR, SH, SHA, SUB, SUBC, XOR
 290         case RI_TWO:
 291                 if (parm == 37)
 292                         altbankok = 1;                      // MOVEFA
 293
 294                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 295                 CHECK_COMMA;
 296
 297                 if (parm == 36)
 298                         altbankok = 1;                      // MOVETA
 299
 300                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 301                 DepositRISCInstructionWord(parm, reg1, reg2);
 302                 break;
 303
 304         // Numeric operand (n,Rd) where n = -16..+15
 305         // CMPQ
 306         case RI_NUM_15:
 307
 308         // Numeric operand (n,Rd) where n = 0..31
 309         // BCLR, BSET, BTST, MOVEQ
 310         case RI_NUM_31:
 311
 312         // Numeric operand (n,Rd) where n = 1..32
 313         // ADDQ, ADDQMOD, ADDQT, SHARQ, SHLQ, SHRQ, SUBQ, SUBQMOD, SUBQT, ROLQ,
 314         // RORQ
 315         case RI_NUM_32:
 316                 switch (type)
 317                 {
 318                 case RI_NUM_15:
 319                         reg1 = -16; reg2 = 15; attrflg = FU_NUM15;
 320                         break;
 321                 default:
 322                 case RI_NUM_31:
 323                         reg1 =   0; reg2 = 31; attrflg = FU_NUM31;
 324                         break;
 325                 case RI_NUM_32:
 326                         reg1 =   1; reg2 = 32; attrflg = FU_NUM32;
 327                         break;
 328                 }
 329
 330                 if (parm & SUB32)
 331                         attrflg |= FU_SUB32;
 332
 333                 if (*tok != '#')
 334                         return MalformedOpcode(MALF_NUM);
 335
 336                 tok++;
 337                 riscImmTokenSeen = 1;
 338
 339                 if (expr(r_expr, &eval, &eattr, &esym) != OK)
 340                         return MalformedOpcode(MALF_EXPR);
 341
 342                 if (!(eattr & DEFINED))
 343                 {
 344                         AddFixup((WORD)(FU_WORD | attrflg), sloc, r_expr);
 345                         reg1 = 0;
 346                 }
 347                 else
 348                 {
 349                         if (esym && (esym->sattre & EQUATEDREG))
 350                                 return error("equated register seen for immediate value");
 351
 352                         if (eattr & RISCREG)
 353                                 return error("register seen for immediate value");
 354
 355                         if (((int)eval < reg1) || ((int)eval > reg2))
 356                                 return error("constant out of range (%d to %d)", reg1, reg2);
 357
 358                         if (parm & SUB32)
 359                                 reg1 = 32 - (int)eval;
 360                         else if (type == RI_NUM_32)
 361                                 reg1 = (reg1 == 32 ? 0 : (int)eval);
 362                         else
 363                                 reg1 = (int)eval;
 364                 }
 365
 366                 CHECK_COMMA;
 367                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 368                 DepositRISCInstructionWord(parm, reg1, reg2);
 369                 break;
 370
 371         // Move Immediate--n,Rn--n in Second Word
 372         case RI_MOVEI:
 373                 if (*tok != '#')
 374                         return MalformedOpcode(MALF_NUM);
 375
 376                 tok++;
 377                 riscImmTokenSeen = 1;
 378
 379                 // Check for equated register after # and return error if so
 380                 if (*tok == SYMBOL)
 381                 {
 382                         sy = lookup(string[tok[1]], LABEL, 0);
 383
 384                         if (sy && (sy->sattre & EQUATEDREG))
 385                                 return error("equated register in 1st operand of MOVEI instruction");
 386                 }
 387
 388                 if (expr(r_expr, &eval, &eattr, &esym) != OK)
 389                         return MalformedOpcode(MALF_EXPR);
 390
 391                 if ((lastOpcode == RI_JUMP) || (lastOpcode == RI_JR))
 392                 {
 393                         if (legacy_flag)
 394                         {
 395                                 // User doesn't care, emit a NOP to fix
 396                                 DepositRISCInstructionWord(57, 0, 0);
 397                                 warn("MOVEI following JUMP, inserting NOP to fix your BROKEN CODE");
 398                         }
 399                         else
 400                                 warn("MOVEI immediately follows JUMP");
 401                 }
 402
 403                 if (!(eattr & DEFINED))
 404                 {
 405                         AddFixup(FU_LONG | FU_MOVEI, sloc + 2, r_expr);
 406                         eval = 0;
 407                 }
 408                 else
 409                 {
 410                         if (eattr & TDB)
 411                                 MarkRelocatable(cursect, sloc + 2, (eattr & TDB), (MLONG | MMOVEI), NULL);
 412                 }
 413
 414                 CHECK_COMMA;
 415                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 416
 417                 DepositRISCInstructionWord(parm, 0, reg2);
 418                 val = WORDSWAP32(eval);
 419                 D_long(val);
 420                 break;
 421
 422         // PC,Rd or Rs,Rd
 423         case RI_MOVE:
 424                 if (*tok == KW_PC)
 425                 {
 426                         parm = 51;
 427                         reg1 = 0;
 428                         tok++;
 429                 }
 430                 else
 431                 {
 432                         parm = 34;
 433                         EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 434                 }
 435
 436                 CHECK_COMMA;
 437                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 438                 DepositRISCInstructionWord(parm, reg1, reg2);
 439                 break;
 440
 441         // (Rn),Rn = 41 / (R14/R15+n),Rn = 43/44 / (R14/R15+Rn),Rn = 58/59
 442         case RI_LOAD:
 443                 indexed = 0;
 444                 parm = 41;
 445
 446                 if (*tok != '(')
 447                         return MalformedOpcode(MALF_LPAREN);
 448
 449                 tok++;
 450
 451         if ((tok[1] == '+') || (tok[1] == '-'))
 452                 {
 453                         // Trying to make indexed call
 454                         if ((*tok == KW_R14) || (*tok == KW_R15))
 455                                 indexed = (*tok - KW_R0);
 456                         else
 457                                 return IllegalIndexedRegister(*tok);
 458                 }
 459
 460                 if (!indexed)
 461                 {
 462                         EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 463                 }
 464                 else
 465                 {
 466                         reg1 = indexed;
 467                         indexed = 0;
 468                         tok++;
 469
 470                         if (*tok == '+')
 471                         {
 472                                 parm = (WORD)(reg1 - 14 + 58);
 473                                 tok++;
 474
 475                                 if ((*tok >= KW_R0) && (*tok <= KW_R31))
 476                                         indexed = 1;
 477
 478                                 if (*tok == SYMBOL)
 479                                 {
 480                                         sy = lookup(string[tok[1]], LABEL, 0);
 481
 482                                         if (!sy)
 483                                         {
 484                                                 error(reg_err);
 485                                                 return ERROR;
 486                                         }
 487
 488                                         if (sy->sattre & EQUATEDREG)
 489                                                 indexed = 1;
 490                                 }
 491
 492                                 if (indexed)
 493                                 {
 494                                         EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 495                                 }
 496                                 else
 497                                 {
 498                                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 499                                                 return MalformedOpcode(MALF_EXPR);
 500
 501                                         if (!(eattr & DEFINED))
 502                                                 return error("constant expected after '+'");
 503
 504                                         reg1 = (int)eval;
 505
 506                                         if (reg1 == 0)
 507                                         {
 508                                                 reg1 = 14 + (parm - 58);
 509                                                 parm = 41;
 510                                                 warn("NULL offset in LOAD ignored");
 511                                         }
 512                                         else
 513                                         {
 514                                                 if ((reg1 < 1) || (reg1 > 32))
 515                                                         return error("constant in LOAD out of range (1-32)");
 516
 517                                                 if (reg1 == 32)
 518                                                         reg1 = 0;
 519
 520                                                 parm = (WORD)(parm - 58 + 43);
 521                                         }
 522                                 }
 523                         }
 524                         else
 525                         {
 526                                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 527                         }
 528                 }
 529
 530                 if (*tok != ')')
 531                         return MalformedOpcode(MALF_RPAREN);
 532
 533                 tok++;
 534                 CHECK_COMMA;
 535                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 536                 DepositRISCInstructionWord(parm, reg1, reg2);
 537                 break;
 538
 539         // Rn,(Rn) = 47 / Rn,(R14/R15+n) = 49/50 / Rn,(R14/R15+Rn) = 60/61
 540         case RI_STORE:
 541                 parm = 47;
 542                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 543                 CHECK_COMMA;
 544
 545                 if (*tok != '(')
 546                         return MalformedOpcode(MALF_LPAREN);
 547
 548                 tok++;
 549                 indexed = 0;
 550
 551                 if (((*tok == KW_R14) || (*tok == KW_R15)) && (tok[1] != ')'))
 552                         indexed = *tok - KW_R0;
 553
 554                 if (!indexed)
 555                 {
 556                         EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 557                 }
 558                 else
 559                 {
 560                         reg2 = indexed;
 561                         indexed = 0;
 562                         tok++;
 563
 564                         if (*tok == '+')
 565                         {
 566                                 parm = (WORD)(reg2 - 14 + 60);
 567                                 tok++;
 568
 569                                 if ((*tok >= KW_R0) && (*tok <= KW_R31))
 570                                         indexed = 1;
 571
 572                                 if (*tok == SYMBOL)
 573                                 {
 574                                         sy = lookup(string[tok[1]], LABEL, 0);
 575
 576                                         if (!sy)
 577                                         {
 578                                                 error(reg_err);
 579                                                 return ERROR;
 580                                         }
 581
 582                                         if (sy->sattre & EQUATEDREG)
 583                                                 indexed = 1;
 584                                 }
 585
 586                                 if (indexed)
 587                                 {
 588                                         EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 589                                 }
 590                                 else
 591                                 {
 592                                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 593                                                 return MalformedOpcode(MALF_EXPR);
 594
 595                                         if (!(eattr & DEFINED))
 596                                         {
 597                                                 AddFixup(FU_WORD | FU_REGTWO, sloc, r_expr);
 598                                                 reg2 = 0;
 599                                         }
 600                                         else
 601                                         {
 602                                                 reg2 = (int)eval;
 603
 604                                                 if (reg2 == 0)
 605                                                 {
 606                                                         reg2 = 14 + (parm - 60);
 607                                                         parm = 47;
 608                                                         warn("NULL offset in STORE ignored");
 609                                                 }
 610                                                 else
 611                                                 {
 612                                                         if ((reg2 < 1) || (reg2 > 32))
 613                                                                 return error("constant in STORE out of range (1-32)");
 614
 615                                                         if (reg2 == 32)
 616                                                                 reg2 = 0;
 617
 618                                                         parm = (WORD)(parm - 60 + 49);
 619                                                 }
 620                                         }
 621                                 }
 622                         }
 623                         else
 624                         {
 625                                 EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 626                         }
 627                 }
 628
 629                 if (*tok != ')')
 630                         return MalformedOpcode(MALF_RPAREN);
 631
 632                 tok++;
 633                 CHECK_EOL;
 634                 DepositRISCInstructionWord(parm, reg2, reg1);
 635                 break;
 636
 637         // LOADB/LOADP/LOADW (Rn),Rn
 638         case RI_LOADN:
 639                 if (*tok != '(')
 640                         return MalformedOpcode(MALF_LPAREN);
 641
 642                 tok++;
 643                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 644
 645                 if (*tok != ')')
 646                         return MalformedOpcode(MALF_RPAREN);
 647
 648                 tok++;
 649                 CHECK_COMMA;
 650                 EVAL_REG_RETURN_IF_ERROR_OR_NO_EOL(reg2, FU_REGTWO);
 651                 DepositRISCInstructionWord(parm, reg1, reg2);
 652                 break;
 653
 654         // STOREB/STOREP/STOREW Rn,(Rn)
 655         case RI_STOREN:
 656                 EVAL_REG_RETURN_IF_ERROR(reg1, FU_REGONE);
 657                 CHECK_COMMA;
 658
 659                 if (*tok != '(')
 660                         return MalformedOpcode(MALF_LPAREN);
 661
 662                 tok++;
 663                 EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 664
 665                 if (*tok != ')')
 666                         return MalformedOpcode(MALF_RPAREN);
 667
 668                 tok++;
 669                 CHECK_EOL;
 670                 DepositRISCInstructionWord(parm, reg2, reg1);
 671                 break;
 672
 673         // Jump Relative - cc,n - n=-16..+15 words, reg2=cc
 674         case RI_JR:
 675
 676         // Jump Absolute - cc,(Rs) - reg2=cc
 677         case RI_JUMP:
 678                 // Check to see if there is a comma in the token string. If not then
 679                 // the JR or JUMP should default to 0, Jump Always
 680                 commaFound = 0;
 681
 682                 for(t=tok; *t!=EOL; t++)
 683                 {
 684                         if (*t == ',')
 685                         {
 686                                 commaFound = 1;
 687                                 break;
 688                         }
 689                 }
 690
 691                 if (commaFound)
 692                 {
 693                         if (*tok == CONST)
 694                         {
 695                                 // CC using a constant number (O_o)
 696                                 PTR tp;
 697                                 tp.tk = tok + 1;
 698                                 val = *tp.i64++;
 699                                 tok = tp.tk;
 700                                 CHECK_COMMA;
 701                         }
 702                         else if (*tok == SYMBOL)
 703                         {
 704                                 val = 9999;
 705                                 strcpy(scratch, string[tok[1]]);
 706                                 strtoupper(scratch);
 707
 708                                 for(i=0; i<MAXINTERNCC; i++)
 709                                 {
 710                                         // Look for the condition code & break if found
 711                                         if (strcmp(condname[i], scratch) == 0)
 712                                         {
 713                                                 val = condnumber[i];
 714                                                 break;
 715                                         }
 716                                 }
 717
 718                                 // Standard CC was not found, look for an equated one
 719                                 if (val == 9999)
 720                                 {
 721                                         ccsym = lookup(string[tok[1]], LABEL, 0);
 722
 723                                         if (ccsym && (ccsym->sattre & EQUATEDCC) && !(ccsym->sattre & UNDEF_CC))
 724                                                 val = (int)ccsym->svalue;
 725                                         else
 726                                                 return error("unknown condition code");
 727                                 }
 728
 729                                 tok += 2;
 730                                 CHECK_COMMA;
 731                         }
 732                         else if (*tok == '(')
 733                         {
 734                                 // Set CC to "Jump Always"
 735                                 val = 0;
 736                         }
 737                 }
 738                 else
 739                 {
 740                         // Set CC to "Jump Always"
 741                         val = 0;
 742                 }
 743
 744                 if ((val < 0) || (val > 31))
 745                         return error("condition constant out of range");
 746
 747                 // Store condition code
 748                 reg1 = val;
 749
 750                 if (type == RI_JR)
 751                 {
 752                         // JR cc,n
 753                         if (expr(r_expr, &eval, &eattr, &esym) != OK)
 754                                 return MalformedOpcode(MALF_EXPR);
 755
 756                         if (!(eattr & DEFINED))
 757                         {
 758                                 AddFixup(FU_WORD | FU_JR, sloc, r_expr);
 759                                 reg2 = 0;
 760                         }
 761                         else
 762                         {
 763                                 reg2 = ((int)(eval - ((orgactive ? orgaddr : sloc) + 2))) / 2;
 764
 765                                 if ((reg2 < -16) || (reg2 > 15))
 766                                         error("PC relative overflow in JR (outside of -16 to 15)");
 767                         }
 768                 }
 769                 else
 770                 {
 771                         // JUMP cc, (Rn)
 772                         if (*tok != '(')
 773                                 return MalformedOpcode(MALF_LPAREN);
 774
 775                         tok++;
 776                         EVAL_REG_RETURN_IF_ERROR(reg2, FU_REGTWO);
 777
 778                         if (*tok != ')')
 779                                 return MalformedOpcode(MALF_RPAREN);
 780
 781                         tok++;
 782                         CHECK_EOL;
 783                 }
 784
 785                 DepositRISCInstructionWord(parm, reg2, reg1);
 786                 break;
 787
 788         // We should never get here. If we do, somebody done fucked up. :-D
 789         default:
 790                 return error("Unknown RISC opcode type");
 791         }
 792
 793         lastOpcode = type;
 794         return 0;
 795 }