Shamusworld >> Repos - rmac/blob - parmode.h

   1 //
   2 // RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System
   3 // PARMODE.C - Addressing Modes Parser Include
   4 // Copyright (C) 199x Landon Dyer, 2011 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 // This file is included (twice) to parse two addressing modes, into slightly
  10 // different var names
  11 {
  12         // Dn
  13         // An
  14         // # expression
  15         if ((*tok >= KW_D0) && (*tok <= KW_D7))
  16         {
  17                 AMn = DREG;
  18                 AnREG = *tok++ & 7;
  19         }
  20         else if ((*tok >= KW_A0) && (*tok <= KW_A7))
  21         {
  22                 AMn = AREG;
  23                 AnREG = *tok++ & 7;
  24         }
  25         else if (*tok == '#')
  26         {
  27                 ++tok;
  28                 if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
  29                         return ERROR;
  30
  31                 AMn = IMMED;
  32         }
  33         // (An)
  34         // (An)+
  35         // (An,Xn[.siz][*scale])
  36         // (PC,Xn[.siz][*scale])
  37         // (d16,An)
  38         // (d8,An,Xn[.siz][*scale])
  39         // (d16,PC)
  40         // (d8,PC,Xn[.siz][*scale])
  41         // ([bd,An],Xn,od)
  42         // ([bd,An,Xn],od)
  43         // ([bd,PC],Xn,od)
  44         // ([bd,PC,Xn],od)
  45         else if (*tok == '(')
  46         {
  47                 ++tok;
  48
  49                 if ((*tok >= KW_A0) && (*tok <= KW_A7))
  50                 {
  51                         AnREG = *tok++ & 7;
  52
  53                         if (*tok == ')')
  54                         {
  55                                 ++tok;
  56
  57                                 if (*tok == '+')
  58                                 {
  59                                         ++tok;
  60                                         AMn = APOSTINC;
  61                                 }
  62                                 else
  63                                         AMn = AIND;
  64
  65                                 goto AnOK;
  66                         }
  67
  68                         AMn = AINDEXED;
  69                         goto AMn_IX0;                                      // Handle ",Xn[.siz][*scale])"
  70                 }
  71                 else if (*tok == KW_PC)
  72                 {                            // (PC,Xn[.siz][*scale])
  73                         ++tok;
  74                         AMn = PCINDEXED;
  75
  76                         // Common index handler; enter here with `tok' pointing at the comma.
  77
  78                         AMn_IX0:                                           // Handle indexed with missing expr
  79
  80                         AnEXVAL = 0;
  81                         AnEXATTR = ABS | DEFINED;
  82
  83                         AMn_IXN:                                           // Handle any indexed (tok -> a comma)
  84
  85                         if (*tok++ != ',')
  86                                 goto badmode;
  87
  88                         if (*tok < KW_D0 || *tok > KW_A7)
  89                                 goto badmode;
  90
  91                         AnIXREG = *tok++ & 15;
  92
  93                         switch ((int)*tok)
  94                         {                                // Index reg size: <empty> | .W | .L
  95                         case DOTW:
  96                                 ++tok;
  97                         default:
  98                                 AnIXSIZ = 0;
  99                                 break;
 100                         case DOTL:
 101                                 AnIXSIZ = 0x0800;
 102                                 ++tok;
 103                                 break;
 104                         case DOTB:                                      // .B not allowed here...
 105                                 goto badmode;
 106                         }
 107
 108                         if (*tok == '*')
 109                         {                                  // scale: *1, *2, *4, *8
 110                                 ++tok;
 111                                 if (*tok++ != CONST || *tok > 8)
 112                                         goto badmode;
 113
 114                                 switch ((int)*tok++)
 115                                 {
 116                                 case 1:
 117                                         break;
 118                                 case 2:
 119                                         AnIXSIZ |= TIMES2;
 120                                         break;
 121                                 case 4:
 122                                         AnIXSIZ |= TIMES4;
 123                                         break;
 124                                 case 8:
 125                                         AnIXSIZ |= TIMES8;
 126                                         break;
 127                                 default:
 128                                         goto badmode;
 129                                 }
 130                         }
 131
 132                         if (*tok++ != ')')                                  // final ")"
 133                                 goto badmode;
 134
 135                         goto AnOK;
 136                 }
 137                 else if (*tok == '[')
 138                 {                              // ([...
 139                         goto unmode;
 140                 }
 141                 else
 142                 {                                              // (expr...
 143                         if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
 144                                 return ERROR;
 145
 146                         if (*tok++ != ',')
 147                                 goto badmode;
 148
 149                         if ((*tok >= KW_A0) && (*tok <= KW_A7))
 150                         {
 151                                 AnREG = *tok & 7;
 152                                 ++tok;
 153
 154                                 if (*tok == ',')
 155                                 {
 156                                         AMn = AINDEXED;
 157                                         goto AMn_IXN;
 158                                 }
 159                                 else if (*tok == ')')
 160                                 {
 161                                         AMn = ADISP;
 162                                         ++tok;
 163                                         goto AnOK;
 164                                 }
 165                                 else
 166                                         goto badmode;
 167                         }
 168                         else if (*tok == KW_PC)
 169                         {
 170                                 if (*++tok == ',')
 171                                 {                             // expr(PC,Xn...)
 172                                         AMn = PCINDEXED;
 173                                         goto AMn_IXN;
 174                                 }
 175                                 else if (*tok == ')')
 176                                 {
 177                                         AMn = PCDISP;                                // expr(PC)
 178                                         ++tok;
 179                                         goto AnOK;
 180                                 }
 181                                 else
 182                                         goto badmode;
 183                         }
 184                         else
 185                                 goto badmode;
 186                 }
 187         }
 188         else if (*tok=='-' && tok[1]=='(' && ((tok[2]>=KW_A0) && (tok[2]<=KW_A7)) && tok[3]==')')
 189         {
 190                 AMn = APREDEC;
 191                 AnREG = tok[2] & 7;
 192                 tok += 4;
 193         }
 194         else if (*tok == KW_CCR)
 195         {
 196                 AMn = AM_CCR;
 197                 ++tok;
 198                 goto AnOK;
 199         }
 200         else if (*tok == KW_SR)
 201         {
 202                 AMn = AM_SR;
 203                 ++tok;
 204                 goto AnOK;
 205         }
 206         else if (*tok == KW_USP)
 207         {
 208                 AMn = AM_USP;
 209                 ++tok;
 210                 goto AnOK;
 211         }
 212         // expr
 213         // expr.w
 214         // expr.l
 215         // d16(An)
 216         // d8(An,Xn[.siz])
 217         // d16(PC)
 218         // d8(PC,Xn[.siz])
 219         else
 220         {
 221                 if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
 222                         return ERROR;
 223
 224                 if (*tok == DOTW)
 225                 {                                    // expr.W
 226                         ++tok;
 227                         AMn = ABSW;
 228                         goto AnOK;
 229                 }
 230                 else if (*tok != '(')
 231                 {                              // expr[.L]
 232                         AMn = ABSL;
 233                         // Defined, absolute values from $FFFF8000..$00007FFF get optimized to absolute short
 234
 235                         if ((AnEXATTR & (TDB|DEFINED)) == DEFINED && (AnEXVAL + 0x8000) < 0x10000)
 236                                 AMn = ABSW;
 237
 238                         if (*tok == DOTL)
 239                         {                                 // force .L
 240                                 ++tok;
 241                                 AMn = ABSL;
 242                         }
 243
 244                         goto AnOK;
 245                 }
 246
 247                 ++tok;
 248
 249                 if ((*tok >= KW_A0) && (*tok <= KW_A7))
 250                 {
 251                         AnREG = *tok++ & 7;
 252
 253                         if (*tok == ')')
 254                         {
 255                                 AMn = ADISP;
 256                                 ++tok;
 257                                 goto AnOK;
 258                         }
 259
 260                         AMn = AINDEXED;
 261                         goto AMn_IXN;
 262                 }
 263                 else if (*tok == KW_PC)
 264                 {
 265                         if (*++tok == ')')
 266                         {
 267                                 AMn = PCDISP;
 268                                 ++tok;
 269                                 goto AnOK;
 270                         }
 271
 272                         AMn = PCINDEXED;
 273                         goto AMn_IXN;
 274                 }
 275                 goto badmode;
 276         }
 277
 278         // Addressing mode OK
 279
 280         AnOK:
 281         ;
 282 }
 283
 284 // Cleanup dirty little macros
 285 #undef AnOK
 286 #undef AMn
 287 #undef AnREG
 288 #undef AnIXREG
 289 #undef AnIXSIZ
 290 #undef AnEXPR
 291 #undef AnEXVAL
 292 #undef AnEXATTR
 293 #undef AnOEXPR
 294 #undef AnOEXVAL
 295 #undef AnOEXATTR
 296 #undef AnESYM
 297 #undef AMn_IX0
 298 #undef AMn_IXN