sdcc/sdas/as8051/i51adr.c

   1 /* i51adr.c */
   2
   3 /*
   4  *  Copyright (C) 1998-2009  Alan R. Baldwin
   5  *
   6  *  This program is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  *
  19  *
  20  * Alan R. Baldwin
  21  * 721 Berkeley St.
  22  * Kent, Ohio  44240
  23  *
  24  *      This Assember Ported by
  25  *      John L. Hartman (JLH)
  26  *      jhartman at compuserve dot com
  27  *      noice at noicedebugger dot com
  28  *
  29  */
  30
  31 #include "asxxxx.h"
  32 #include "i8051.h"
  33
  34
  35 struct adsym reg51[] = {        /* R0 thru R7 registers */
  36     {   "R0",   R0      },
  37     {   "R1",   R1      },
  38     {   "R2",   R2      },
  39     {   "R3",   R3      },
  40     {   "R4",   R4      },
  41     {   "R5",   R5      },
  42     {   "R6",   R6      },
  43     {   "R7",   R7      },
  44     {   "A",    A       },
  45     {   "DPTR", DPTR    },
  46     {   "PC",   PC      },
  47     {   "C",    C       },
  48     {   "AB",   AB      },
  49     {   "",     0x00    }
  50 };
  51
  52 /*  Classify argument as to address mode */
  53 int
  54 addr(struct expr *esp)
  55 {
  56         int c;
  57         unsigned rd;
  58
  59         if ((c = getnb()) == '#') {
  60                 /*  Immediate mode */
  61                 expr(esp, 0);
  62                 esp->e_mode = S_IMMED;
  63         }
  64         else if (c == '@') {
  65                 /* choices are @R0, @R1, @DPTR, @A+PC, @A+DPTR */
  66                 switch (reg()) {
  67                 case R0:
  68                         esp->e_mode = S_AT_R;
  69                         esp->e_addr = R0;
  70                         break;
  71                 case R1:
  72                         esp->e_mode = S_AT_R;
  73                         esp->e_addr = R1;
  74                         break;
  75                 case DPTR:
  76                         esp->e_mode = S_AT_DP;
  77                         esp->e_addr = DPTR;
  78                         break;
  79                 case A:
  80                         if (getnb() == '+') {
  81                                 rd = reg();
  82                                 if (rd == PC) {
  83                                         esp->e_mode = S_AT_APC;
  84                                         esp->e_addr = 0;
  85                                 } else if (rd == DPTR) {
  86                                         esp->e_mode = S_AT_ADP;
  87                                         esp->e_addr = 0;
  88                                 } else {
  89                                         xerr('a', "@A+DPTR and A,@A+PC are the allowed modes.");
  90                                 }
  91                         } else
  92                                 xerr('a', "Invalid Addressing Mode.");
  93                         break;
  94                 }
  95
  96                 esp->e_flag = 0;
  97                 esp->e_base.e_ap = NULL;
  98         }
  99         else if (c == '*') {
 100                 if ((c = getnb()) == '/') {
 101                         /* Force inverted bit */
 102                         expr(esp, 0);
 103                         esp->e_mode = S_NOT_BIT;
 104                 } else {
 105                         unget(c);
 106                         /* Force direct page */
 107                         expr(esp, 0);
 108                         esp->e_mode = S_DIR;
 109                 }
 110                 if (esp->e_addr & ~0xFF)
 111                         xerr('d', "A Direct Page addressing error.");
 112         }
 113         else if (c == '/') {
 114                 /* Force inverted bit  */
 115                 expr(esp, 0);
 116                 esp->e_mode = S_NOT_BIT;
 117         }
 118         else {
 119                 unget(c);
 120
 121                 /* try for register: A, AB, R0-R7, DPTR, PC, Cy */
 122                 if ((esp->e_addr = admode(reg51)) != -1) {
 123                         switch (esp->e_addr) {
 124                         case A:
 125                                 esp->e_mode = S_A;
 126                                 break;
 127                         case AB:
 128                                 esp->e_mode = S_RAB;
 129                                 break;
 130                         case DPTR:
 131                                 esp->e_mode = S_DPTR;
 132                                 break;
 133                         case PC:
 134                                 esp->e_mode = S_PC;
 135                                 break;
 136                         case C:
 137                                 esp->e_mode = S_C;
 138                                 break;
 139                         default:
 140                                 /* R0-R7 */
 141                                 esp->e_mode = S_REG;
 142                         }
 143                 } else {
 144                         /* Must be an expression */
 145                         esp->e_addr = 0;
 146                         expr(esp, 0);
 147                         if ((!esp->e_flag)
 148                                 && (esp->e_base.e_ap==NULL)
 149                                 && !(esp->e_addr & ~0xFF)) {
 150                                 esp->e_mode = S_DIR;
 151                         } else {
 152                                 esp->e_mode = S_EXT;
 153                         }
 154                 }
 155         }
 156         return (esp->e_mode);
 157 }
 158
 159 /*
 160  * Enter admode() to search a specific addressing mode table
 161  * for a match. Return the addressing value on a match or
 162  * -1 for no match.
 163  */
 164 int
 165 admode(struct adsym *sp)
 166 {
 167         char *ptr;
 168         int i;
 169
 170         unget(getnb());
 171         i = 0;
 172         while ( *(ptr = &sp[i].a_str[0]) ) {
 173                 if (srch(ptr)) {
 174                         return(sp[i].a_val);
 175                 }
 176                 i++;
 177         }
 178         return(-1);
 179 }
 180
 181 /*
 182  *      srch --- does string match ?
 183  */
 184 int
 185 srch(char *str)
 186 {
 187         char *ptr;
 188         ptr = ip;
 189
 190         while (*ptr && *str) {
 191                 if(ccase[*ptr & 0x007F] != ccase[*str & 0x007F])
 192                         break;
 193                 ptr++;
 194                 str++;
 195         }
 196         if (ccase[*ptr & 0x007F] == ccase[*str & 0x007F]) {
 197                 ip = ptr;
 198                 return(1);
 199         }
 200
 201         if (!*str)
 202                 if (any(*ptr," \t\n,];")) {
 203                         ip = ptr;
 204                         return(1);
 205                 }
 206         return(0);
 207 }
 208
 209 /*
 210  *      any --- does str contain c?
 211  */
 212 int
 213 any(int c, char *str)
 214 {
 215         while (*str)
 216                 if(*str++ == c)
 217                         return(1);
 218         return(0);
 219 }
 220
 221 /*
 222  * Read a register name.  Return register value, -1 if no register found
 223  */
 224 int
 225 reg(void)
 226 {
 227         struct mne *mp;
 228         char id[NCPS];
 229
 230         getid(id, -1);
 231         if ((mp = mlookup(id))==NULL) {
 232                 aerr();
 233                 return (-1);
 234         }
 235         switch (mp->m_type) {
 236         case S_A:
 237         case S_AB:
 238         case S_DPTR:
 239         case S_PC:
 240         case S_REG:
 241                 return ((int) mp->m_valu);
 242
 243         default:
 244                 return (-1);
 245         }
 246 }