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annotate src/insn_indexed.c @ 84:e12edcfbebd5
Fixed problem with expression evaluation infrastructure not advancing input pointer on pass 2
| author | lost |
|---|---|
| date | Wed, 14 Jan 2009 07:04:45 +0000 |
| parents | b6b1e79cc277 |
| children | f59c0916753d |
| rev | line source |
|---|---|
| 32 | 1 /* |
| 2 insn_indexed.c | |
|
33
74a3fef7c8d0
Added general addressing modes (immediate, base page, extended, indexed)
lost
parents:
32
diff
changeset
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3 Copyright © 2009 William Astle |
| 32 | 4 |
| 5 This file is part of LWASM. | |
| 6 | |
| 7 LWASM is free software: you can redistribute it and/or modify it under the | |
| 8 terms of the GNU General Public License as published by the Free Software | |
| 9 Foundation, either version 3 of the License, or (at your option) any later | |
| 10 version. | |
| 11 | |
| 12 This program is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 15 more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License along with | |
| 18 this program. If not, see <http://www.gnu.org/licenses/>. | |
| 19 */ | |
| 20 | |
| 21 /* | |
| 22 for handling indexed mode instructions | |
| 23 */ | |
| 24 | |
| 25 #define __insn_indexed_c_seen__ | |
| 26 | |
| 27 #include <ctype.h> | |
| 28 #include <string.h> | |
| 29 | |
| 30 #include "lwasm.h" | |
| 31 #include "instab.h" | |
| 32 #include "expr.h" | |
| 33 | |
| 34 void insn_indexed_aux(asmstate_t *as, lwasm_line_t *l, const char **p, int *b1, int *b2, int *b3) | |
| 35 { | |
| 36 static const char *regs = "X Y U S W PCRPC "; | |
| 37 static const struct { char *opstr; int pb; } simpleindex[] = | |
| 38 { | |
| 39 {",x", 0x84}, {",y", 0xa4}, {",u", 0xc4}, {",s", 0xe4}, | |
| 40 {",x+", 0x80}, {",y+", 0xa0}, {",u+", 0xc0}, {",s+", 0xe0}, | |
| 41 {",x++", 0x81}, {",y++", 0xa1}, {",u++", 0xc1}, {",s++", 0xe1}, | |
| 42 {",-x", 0x82}, {",-y", 0xa2}, {",-u", 0xc2}, {",-s", 0xe2}, | |
| 43 {",--x", 0x83}, {",--y", 0xa3}, {",--u", 0xc3}, {",--s", 0xe3}, | |
| 44 {"a,x", 0x86}, {"a,y", 0xa6}, {"a,u", 0xc6}, {"a,s", 0xe6}, | |
| 45 {"b,x", 0x85}, {"b,y", 0xa5}, {"b,u", 0xc5}, {"b,s", 0xe5}, | |
| 46 {"e,x", 0x87}, {"e,y", 0xa7}, {"e,u", 0xc7}, {"e,s", 0xe7}, | |
| 47 {"f,x", 0x8a}, {"f,y", 0xaa}, {"f,u", 0xca}, {"f,s", 0xea}, | |
| 48 {"d,x", 0x8b}, {"d,y", 0xab}, {"d,u", 0xcb}, {"d,s", 0xed}, | |
| 49 {"w,x", 0x8e}, {"w,y", 0xae}, {"w,u", 0xce}, {"w,s", 0xee}, | |
| 50 {",w", 0x8f}, {",w++", 0xcf}, {",--w", 0xef}, | |
| 51 | |
| 52 {"[,x]", 0x94}, {"[,y]", 0xb4}, {"[,u", 0xd4}, {"[,s]", 0xf4}, | |
| 53 {"[,x++]", 0x91}, {"[,y++]", 0xb1}, {"[,u++]", 0xd1}, {"[,s++]", 0xf1}, | |
| 54 {"[,--x]", 0x93}, {"[,--y]", 0xb3}, {"[,--u]", 0xd3}, {"[,--s]", 0xf3}, | |
| 55 {"[a,x]", 0x96}, {"[a,y]", 0xb6}, {"[a,u]", 0xd6}, {"[a,s]", 0xf6}, | |
| 56 {"[b,x]", 0x95}, {"[b,y]", 0xb5}, {"[b,u]", 0xd5}, {"[b,s]", 0xf5}, | |
| 57 {"[e,x]", 0x97}, {"[e,y]", 0xb7}, {"[e,u]", 0xd7}, {"[e,s]", 0xf7}, | |
| 58 {"[f,x]", 0x9a}, {"[f,y]", 0xba}, {"[f,u]", 0xda}, {"[f,s]", 0xfa}, | |
| 59 {"[d,x]", 0x9b}, {"[d,y]", 0xbb}, {"[d,u]", 0xdb}, {"[d,s]", 0xfd}, | |
| 60 {"[w,x]", 0x9e}, {"[w,y]", 0xbe}, {"[w,u]", 0xde}, {"[w,s]", 0xfe}, | |
| 61 {"[,w]", 0x90}, {"[,w++]", 0xd0}, {"[,--w]", 0xf0}, | |
| 62 | |
| 63 { "", -1 } | |
| 64 }; | |
| 65 char stbuf[25]; | |
| 81 | 66 int i, j, rn; |
| 67 int f8 = 0, f16 = 0, f0 = 0; | |
| 68 int r, v; | |
| 32 | 69 int indir = 0; |
| 81 | 70 |
| 71 // initialize output bytes | |
| 32 | 72 *b1 = *b2 = *b3 = -1; |
| 73 | |
| 81 | 74 // fetch out operand for lookup |
| 32 | 75 for (i = 0; i < 24; i++) |
| 76 { | |
| 77 if (*((*p) + i) && !isspace(*((*p) + i))) | |
| 78 stbuf[i] = *((*p) + i); | |
| 79 else | |
| 80 break; | |
| 81 } | |
| 82 stbuf[i] = '\0'; | |
| 81 | 83 |
| 84 // now look up operand in "simple" table | |
| 32 | 85 if (!*((*p) + i) || isspace(*((*p) + i))) |
| 86 { | |
| 87 // do simple lookup | |
| 88 for (j = 0; simpleindex[j].opstr[0]; j++) | |
| 89 { | |
| 90 if (!strcasecmp(stbuf, simpleindex[j].opstr)) | |
| 91 break; | |
| 92 } | |
| 93 if (simpleindex[j].opstr[0]) | |
| 94 { | |
| 95 *b1 = simpleindex[j].pb; | |
| 96 (*p) += i; | |
| 97 return; | |
| 98 } | |
| 99 } | |
| 81 | 100 |
| 101 // now do the "hard" ones | |
| 102 | |
| 103 // is it indirect? | |
| 32 | 104 if (**p == '[') |
| 105 { | |
| 106 indir = 1; | |
| 107 (*p)++; | |
| 108 } | |
| 109 | |
| 81 | 110 // look for a "," - all indexed modes have a "," except extended indir |
| 32 | 111 rn = 0; |
| 112 for (i = 0; (*p)[i] && !isspace((*p)[i]); i++) | |
| 113 { | |
| 114 if ((*p)[i] == ',') | |
| 115 { | |
| 116 rn = 1; | |
| 117 break; | |
| 118 } | |
| 119 } | |
| 81 | 120 |
| 121 // if no "," and indirect, do extended indir | |
| 32 | 122 if (!rn && indir) |
| 123 { | |
| 124 // extended indir | |
| 125 *b1 = 0x9f; | |
| 126 *b2 = 0; | |
| 127 *b3 = 0; | |
| 81 | 128 r = lwasm_expr_result2(as, l, (char **)p, 0, &v, 0); |
| 129 if (r < 0) | |
| 32 | 130 { |
| 131 return; | |
| 132 } | |
| 133 if (**p != ']') | |
| 134 { | |
| 135 register_error(as, l, 1, "Bad operand"); | |
| 136 return; | |
| 137 } | |
| 81 | 138 |
| 32 | 139 (*p)++; |
| 81 | 140 |
| 141 if (r == 1 && as -> passnum == 2) | |
| 32 | 142 { |
| 81 | 143 l -> relocoff = as -> addr - l -> codeaddr + 1; |
| 32 | 144 } |
| 81 | 145 |
| 146 *b2 = (v >> 8) & 0xff; | |
| 147 *b3 = v & 0xff; | |
| 32 | 148 return; |
| 149 } | |
| 150 | |
| 81 | 151 // if we've previously forced the offset size, make a note of it |
| 152 if (l -> fsize == 1) | |
| 153 f8 = 1; | |
| 154 else if (l -> fsize == 2) | |
| 155 f16 = 1; | |
| 156 | |
| 32 | 157 if (**p == '<') |
| 158 { | |
| 159 f8 = 1; | |
| 160 (*p)++; | |
| 161 } | |
| 162 else if (**p == '>') | |
| 163 { | |
| 164 f16 = 1; | |
| 165 (*p)++; | |
| 166 } | |
| 167 | |
| 168 if (**p == '0' && *(*p+1) == ',') | |
| 169 { | |
| 170 f0 = 1; | |
| 171 } | |
| 172 | |
| 173 // now we have to evaluate the expression | |
| 81 | 174 r = lwasm_expr_result2(as, l, (char **)p, 0, &v, 0); |
| 175 if (r < 0) | |
| 32 | 176 { |
| 177 return; | |
| 178 } | |
| 81 | 179 if (f8 && r != 0) |
| 32 | 180 { |
| 81 | 181 register_error(as, l, 2, "Illegal external or inter-section reference"); |
| 182 r = 0; | |
| 183 v = 0; | |
| 32 | 184 } |
| 81 | 185 |
| 32 | 186 // now look for a comma; if not present, explode |
| 187 if (*(*p)++ != ',') | |
| 188 { | |
| 189 // syntax error; force 0 bit | |
| 190 *b1 = 00; | |
| 81 | 191 l -> fsize = 0; |
| 32 | 192 return; |
| 193 } | |
| 194 | |
| 195 // now get the register | |
| 196 rn = lwasm_lookupreg3(regs, p); | |
| 197 if (rn < 0) | |
| 81 | 198 { |
| 199 *b1 = 0; | |
| 200 l -> fsize = 0; | |
| 201 register_error(as, l, 1, "Bad register"); | |
| 202 return; | |
| 203 } | |
| 204 | |
| 32 | 205 if (indir) |
| 206 { | |
| 207 if (**p != ']') | |
| 81 | 208 { |
| 209 register_error(as, l, 1, "Bad operand"); | |
| 210 l -> fsize = 0; | |
| 211 *b1 = 0; | |
| 212 return; | |
| 213 } | |
| 32 | 214 else |
| 215 (*p)++; | |
| 216 } | |
| 217 | |
| 81 | 218 // incomplete reference on pass 1 forces 16 bit |
| 219 if (r == 1 && as -> passnum == 1) | |
| 220 { | |
| 221 f16 = 1; | |
| 222 l -> fsize = 2; | |
| 223 } | |
| 224 | |
| 225 // incomplete reference on pass 2 needs relocoff set | |
| 226 if (r == 1 && as -> passnum == 2) | |
| 227 { | |
| 228 l -> relocoff = as -> addr - l -> codeaddr + 1; | |
| 229 } | |
| 230 | |
| 231 // nnnn,W is only 16 bit (or 0 bit) | |
| 32 | 232 if (rn == 4) |
| 233 { | |
| 234 if (f8) | |
| 81 | 235 { |
| 236 register_error(as, l, 1, "n,W cannot be 8 bit"); | |
| 237 l -> fsize = 0; | |
| 238 *b1 = 0; | |
| 239 return; | |
| 240 } | |
| 241 // note: set f16 above for incomplete references | |
| 242 // also set reloc offset | |
| 243 if (!f16 && !f0 && !(as -> pragmas & PRAGMA_NOINDEX0TONONE) && v == 0) | |
| 32 | 244 { |
| 245 if (indir) | |
| 246 *b1 = 0x90; | |
| 247 else | |
| 248 *b1 = 0x8f; | |
| 249 return; | |
| 250 } | |
| 81 | 251 |
| 32 | 252 if (indir) |
| 253 *b1 = 0xb0; | |
| 254 else | |
| 255 *b1 = 0xcf; | |
| 81 | 256 *b2 = (v >> 8) & 0xff; |
| 257 *b3 = v & 0xff; | |
| 32 | 258 return; |
| 259 } | |
| 260 | |
| 81 | 261 // set indir to correct bit value |
| 32 | 262 if (indir) indir = 0x10; |
| 263 | |
| 81 | 264 // PCR? then we have PC relative addressing (like B??, LB??) |
| 32 | 265 if (rn == 5) |
| 266 { | |
| 81 | 267 // FIXME: handle external references sensibly |
| 268 v -= as -> addr; | |
| 32 | 269 |
| 270 // we have a slight problem here | |
| 271 // PCR based on current insn loc is really | |
| 272 // -125 <= offset <= +130 (8 bit offset) | |
| 273 // NOTE: when we are called, we already have the opcode emitted | |
| 274 // so we only need to worry about the size of the operand | |
| 275 // hence the 2 and 3 magic numbers below instead of 3 and 4 | |
| 276 // (and that also avoids errors with two byte opcodes, etc) | |
| 81 | 277 if (f8 || (!f16 && v >= -125 && v <= 130)) |
| 32 | 278 { |
| 279 *b1 = indir | 0x8C; | |
| 81 | 280 v -= 2; |
| 281 if (v < -128 || v > 127) | |
| 32 | 282 register_error(as, l, 2, "Byte overflow"); |
| 81 | 283 *b2 = v & 0xff; |
| 32 | 284 return; |
| 285 } | |
| 286 | |
| 287 // anything else is 16 bit offset | |
| 288 // need 16 bit | |
| 289 *b1 = indir | 0x8D; | |
| 81 | 290 v -= 3; |
| 291 *b2 = (v >> 8) & 0xff; | |
| 292 *b3 = v & 0xff; | |
| 32 | 293 return; |
| 294 } | |
| 295 | |
| 81 | 296 // constant offset from PC (using PC as regular register :) ) |
| 297 // FIXME: handle external references intelligently | |
| 32 | 298 if (rn == 6) |
| 299 { | |
| 81 | 300 if (f8 || (!f16 && v >= -128 && v <= 127)) |
| 32 | 301 { |
| 302 *b1 = indir | 0x8C; | |
| 81 | 303 if (v < -128 || v > 127) |
| 32 | 304 register_error(as, l, 2, "Byte overflow"); |
| 81 | 305 *b2 = v & 0xff; |
| 32 | 306 return; |
| 307 } | |
| 308 | |
| 309 // everything else must be 16 bit | |
| 310 // need 16 bit | |
| 311 *b1 = indir | 0x8D; | |
| 81 | 312 *b2 = (v >> 8) & 0xff; |
| 313 *b3 = v & 0xff; | |
| 32 | 314 return; |
| 315 } | |
| 316 | |
| 317 // we only have to deal with x,y,u,s here | |
| 81 | 318 if (!f8 && !f16 && v >= -16 && v <= 15) |
| 32 | 319 { |
| 81 | 320 // zero offset going to ,R? |
| 321 if (v == 0 && !f0 && !(as -> pragmas & PRAGMA_NOINDEX0TONONE)) | |
| 32 | 322 { |
| 323 *b1 = rn << 5 | indir | 0x80 | 0x04; | |
| 324 return; | |
| 325 } | |
| 81 | 326 |
| 327 // no 5 bit on indirect | |
| 32 | 328 if (indir) |
| 329 { | |
| 330 f8 = 1; | |
| 81 | 331 l -> fsize = 1; |
| 32 | 332 goto no5bit; |
| 333 } | |
| 81 | 334 |
| 335 // 5 bit addressing | |
| 336 *b1 = rn << 5 | (v & 0x1F); | |
| 32 | 337 return; |
| 338 } | |
| 81 | 339 |
| 32 | 340 no5bit: |
| 81 | 341 if (f16 || (!f8 && (v < -128 || v > 127))) |
| 32 | 342 { |
| 343 // must be a 16 bit offset here | |
| 344 *b1 = rn << 5 | indir | 0x80 | 0x09; | |
| 81 | 345 *b2 = (v >> 8) & 0xff; |
| 346 *b3 = v & 0xff; | |
| 32 | 347 return; |
| 348 } | |
| 349 | |
| 350 // if we're here, we have an 8 bit offset | |
| 81 | 351 // note: cannot get here if incomplete reference detected above |
| 32 | 352 *b1 = rn << 5 | indir | 0x80 | 0x08; |
| 81 | 353 if (v < -128 || v > 127) |
| 32 | 354 register_error(as, l, 2, "Byte overflow"); |
| 81 | 355 *b2 = v & 0xff; |
| 32 | 356 return; |
| 357 } | |
| 358 | |
| 359 OPFUNC(insn_indexed) | |
| 360 { | |
| 361 int b1, b2, b3; | |
| 362 | |
| 363 lwasm_emitop(as, l, instab[opnum].ops[0]); | |
| 364 | |
| 365 insn_indexed_aux(as, l, (const char **)p, &b1, &b2, &b3); | |
| 366 if (b1 != -1) | |
| 367 lwasm_emit(as, l, b1); | |
| 368 if (b2 != -1) | |
| 369 lwasm_emit(as, l, b2); | |
| 370 if (b3 != -1) | |
| 371 lwasm_emit(as, l, b3); | |
| 372 } |