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