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9e2e605f DS |
1 | /* @(#)i386.c 6.3 (Berkeley) %G% |
2 | ||
3 | Modified for Berkeley Unix by Donn Seeley, donn@okeeffe.berkeley.edu */ | |
4 | ||
d948810c DS |
5 | /* i386.c -- Assemble code for the Intel 80386 |
6 | Copyright (C) 1989, Free Software Foundation. | |
7 | ||
8 | This file is part of GAS, the GNU Assembler. | |
9 | ||
10 | GAS is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
12 | the Free Software Foundation; either version 1, or (at your option) | |
13 | any later version. | |
14 | ||
15 | GAS is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
21 | along with GAS; see the file COPYING. If not, write to | |
22 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
23 | ||
24 | /* | |
25 | Intel 80386 machine specific gas. | |
26 | Written by Eliot Dresselhaus (eliot@mgm.mit.edu). | |
27 | Bugs & suggestions are completely welcome. This is free software. | |
28 | Please help us make it better. | |
29 | */ | |
30 | ||
31 | #include <stdio.h> | |
32 | #include <varargs.h> | |
33 | #include <ctype.h> | |
34 | ||
35 | #ifdef __GNUC__ | |
36 | #define alloca __builtin_alloca | |
37 | #else | |
38 | extern char *alloca(); | |
39 | #endif | |
40 | #ifdef USG | |
41 | #define index strchr | |
42 | #endif | |
43 | ||
44 | #include "as.h" | |
45 | #include "read.h" | |
46 | #include "flonum.h" | |
47 | #include "obstack.h" | |
48 | #include "frags.h" | |
49 | #include "struc-symbol.h" | |
50 | #include "expr.h" | |
51 | #include "symbols.h" | |
52 | #include "hash.h" | |
53 | #include "md.h" | |
54 | #include "i386.h" | |
55 | #include "i386-opcode.h" | |
56 | ||
57 | long omagic = OMAGIC; | |
58 | char FLT_CHARS[] = "fFdDxX"; | |
59 | char EXP_CHARS[] = "eE"; | |
60 | char line_comment_chars[] = "#"; | |
407d6040 | 61 | char comment_chars[] = "#"; |
d948810c DS |
62 | |
63 | /* tables for lexical analysis */ | |
64 | static char opcode_chars[256]; | |
65 | static char register_chars[256]; | |
66 | static char operand_chars[256]; | |
67 | static char space_chars[256]; | |
68 | static char identifier_chars[256]; | |
69 | static char digit_chars[256]; | |
70 | ||
71 | /* lexical macros */ | |
72 | #define is_opcode_char(x) (opcode_chars[(unsigned char) x]) | |
73 | #define is_operand_char(x) (operand_chars[(unsigned char) x]) | |
74 | #define is_register_char(x) (register_chars[(unsigned char) x]) | |
75 | #define is_space_char(x) (space_chars[(unsigned char) x]) | |
76 | #define is_identifier_char(x) (identifier_chars[(unsigned char) x]) | |
77 | #define is_digit_char(x) (digit_chars[(unsigned char) x]) | |
78 | ||
79 | /* put here all non-digit non-letter charcters that may occur in an operand */ | |
80 | static char operand_special_chars[] = "%$-+(,)*._~/<>|&^!:"; | |
81 | ||
82 | static char *ordinal_names[] = { "first", "second", "third" }; /* for printfs */ | |
83 | ||
84 | /* md_assemble() always leaves the strings it's passed unaltered. To | |
85 | effect this we maintain a stack of saved characters that we've smashed | |
86 | with '\0's (indicating end of strings for various sub-fields of the | |
87 | assembler instruction). */ | |
88 | static char save_stack[32]; | |
89 | static char *save_stack_p; /* stack pointer */ | |
90 | #define END_STRING_AND_SAVE(s) *save_stack_p++ = *s; *s = '\0' | |
91 | #define RESTORE_END_STRING(s) *s = *--save_stack_p | |
92 | ||
93 | /* The instruction we're assembling. */ | |
94 | static i386_insn i; | |
95 | ||
96 | /* Per instruction expressionS buffers: 2 displacements & 2 immediate max. */ | |
97 | static expressionS disp_expressions[2], im_expressions[2]; | |
98 | ||
99 | /* pointers to ebp & esp entries in reg_hash hash table */ | |
100 | static reg_entry *ebp, *esp; | |
101 | ||
102 | static int this_operand; /* current operand we are working on */ | |
103 | ||
104 | /* | |
105 | Interface to relax_segment. | |
106 | There are 2 relax states for 386 jump insns: one for conditional & one | |
107 | for unconditional jumps. This is because the these two types of jumps | |
108 | add different sizes to frags when we're figuring out what sort of jump | |
109 | to choose to reach a given label. */ | |
110 | ||
111 | /* types */ | |
112 | #define COND_JUMP 1 /* conditional jump */ | |
113 | #define UNCOND_JUMP 2 /* unconditional jump */ | |
114 | /* sizes */ | |
115 | #define BYTE 0 | |
116 | #define WORD 1 | |
117 | #define DWORD 2 | |
118 | #define UNKNOWN_SIZE 3 | |
119 | ||
120 | #define ENCODE_RELAX_STATE(type,size) ((type<<2) | (size)) | |
121 | #define SIZE_FROM_RELAX_STATE(s) \ | |
122 | ( (((s) & 0x3) == BYTE ? 1 : (((s) & 0x3) == WORD ? 2 : 4)) ) | |
123 | ||
124 | const relax_typeS md_relax_table[] = { | |
125 | /* | |
126 | The fields are: | |
127 | 1) most positive reach of this state, | |
128 | 2) most negative reach of this state, | |
129 | 3) how many bytes this mode will add to the size of the current frag | |
130 | 4) which index into the table to try if we can't fit into this one. | |
131 | */ | |
132 | {1, 1, 0, 0}, | |
133 | {1, 1, 0, 0}, | |
134 | {1, 1, 0, 0}, | |
135 | {1, 1, 0, 0}, | |
136 | ||
137 | /* For now we don't use word displacement jumps: they may be | |
138 | untrustworthy. */ | |
139 | {127+1, -128+1, 0, ENCODE_RELAX_STATE(COND_JUMP,DWORD) }, | |
140 | /* word conditionals add 3 bytes to frag: | |
141 | 2 opcode prefix; 1 displacement bytes */ | |
142 | {32767+2, -32768+2, 3, ENCODE_RELAX_STATE(COND_JUMP,DWORD) }, | |
143 | /* dword conditionals adds 4 bytes to frag: | |
144 | 1 opcode prefix; 3 displacement bytes */ | |
145 | {0, 0, 4, 0}, | |
146 | {1, 1, 0, 0}, | |
147 | ||
148 | {127+1, -128+1, 0, ENCODE_RELAX_STATE(UNCOND_JUMP,DWORD) }, | |
149 | /* word jmp adds 2 bytes to frag: | |
150 | 1 opcode prefix; 1 displacement bytes */ | |
151 | {32767+2, -32768+2, 2, ENCODE_RELAX_STATE(UNCOND_JUMP,DWORD) }, | |
152 | /* dword jmp adds 3 bytes to frag: | |
153 | 0 opcode prefix; 3 displacement bytes */ | |
154 | {0, 0, 3, 0}, | |
155 | {1, 1, 0, 0}, | |
156 | ||
157 | }; | |
158 | ||
159 | void float_cons (), cons (); | |
160 | ||
161 | /* Ignore certain directives generated by gcc. This probably should | |
162 | not be here. */ | |
163 | void dummy () | |
164 | { | |
165 | while (*input_line_pointer && *input_line_pointer != '\n') | |
166 | input_line_pointer++; | |
167 | } | |
168 | ||
169 | const pseudo_typeS md_pseudo_table[] = { | |
170 | { "ffloat", float_cons, 'f' }, | |
171 | { "dfloat", float_cons, 'd' }, | |
172 | { "tfloat", float_cons, 'x' }, | |
173 | { "value", cons, 2 }, | |
174 | { "ident", dummy, 0 }, /* ignore these directives */ | |
175 | { "def", dummy, 0 }, | |
176 | { "optim", dummy, 0 }, /* For sun386i cc */ | |
177 | { "version", dummy, 0 }, | |
178 | { "ln", dummy, 0 }, | |
179 | { 0, 0, 0 } | |
180 | }; | |
181 | ||
182 | /* for interface with expression () */ | |
183 | extern char * input_line_pointer; | |
184 | char * index (); | |
185 | ||
186 | char * output_invalid (); | |
187 | reg_entry * parse_register (); | |
188 | ||
189 | /* obstack for constructing various things in md_begin */ | |
190 | struct obstack o; | |
191 | ||
192 | /* hash table for opcode lookup */ | |
193 | static struct hash_control *op_hash = (struct hash_control *) 0; | |
194 | /* hash table for register lookup */ | |
195 | static struct hash_control *reg_hash = (struct hash_control *) 0; | |
196 | /* hash table for prefix lookup */ | |
197 | static struct hash_control *prefix_hash = (struct hash_control *) 0; | |
198 | ||
199 | \f | |
200 | void md_begin () | |
201 | { | |
202 | char * hash_err; | |
203 | ||
204 | obstack_begin (&o,4096); | |
205 | ||
206 | /* initialize op_hash hash table */ | |
207 | op_hash = hash_new(); /* xmalloc handles error */ | |
208 | ||
209 | { | |
210 | register template *optab; | |
211 | register templates *core_optab; | |
212 | char *prev_name; | |
213 | ||
214 | optab = i386_optab; /* setup for loop */ | |
215 | prev_name = optab->name; | |
216 | obstack_grow (&o, optab, sizeof(template)); | |
217 | core_optab = (templates *) xmalloc (sizeof (templates)); | |
218 | ||
219 | for (optab++; optab < i386_optab_end; optab++) { | |
220 | if (! strcmp (optab->name, prev_name)) { | |
221 | /* same name as before --> append to current template list */ | |
222 | obstack_grow (&o, optab, sizeof(template)); | |
223 | } else { | |
224 | /* different name --> ship out current template list; | |
225 | add to hash table; & begin anew */ | |
226 | /* Note: end must be set before start! since obstack_next_free changes | |
227 | upon opstack_finish */ | |
228 | core_optab->end = (template *) obstack_next_free(&o); | |
229 | core_optab->start = (template *) obstack_finish(&o); | |
230 | hash_err = hash_insert (op_hash, prev_name, (char *) core_optab); | |
231 | if (hash_err && *hash_err) { | |
232 | hash_error: | |
233 | as_fatal("Internal Error: Can't hash %s: %s",prev_name, hash_err); | |
234 | } | |
235 | prev_name = optab->name; | |
236 | core_optab = (templates *) xmalloc (sizeof(templates)); | |
237 | obstack_grow (&o, optab, sizeof(template)); | |
238 | } | |
239 | } | |
240 | } | |
241 | ||
242 | /* initialize reg_hash hash table */ | |
243 | reg_hash = hash_new(); | |
244 | { | |
245 | register reg_entry *regtab; | |
246 | ||
247 | for (regtab = i386_regtab; regtab < i386_regtab_end; regtab++) { | |
248 | hash_err = hash_insert (reg_hash, regtab->reg_name, regtab); | |
249 | if (hash_err && *hash_err) goto hash_error; | |
250 | } | |
251 | } | |
252 | ||
253 | esp = (reg_entry *) hash_find (reg_hash, "esp"); | |
254 | ebp = (reg_entry *) hash_find (reg_hash, "ebp"); | |
255 | ||
256 | /* initialize reg_hash hash table */ | |
257 | prefix_hash = hash_new(); | |
258 | { | |
259 | register prefix_entry *prefixtab; | |
260 | ||
261 | for (prefixtab = i386_prefixtab; | |
262 | prefixtab < i386_prefixtab_end; prefixtab++) { | |
263 | hash_err = hash_insert (prefix_hash, prefixtab->prefix_name, prefixtab); | |
264 | if (hash_err && *hash_err) goto hash_error; | |
265 | } | |
266 | } | |
267 | ||
268 | /* fill in lexical tables: opcode_chars, operand_chars, space_chars */ | |
269 | { | |
270 | register unsigned int c; | |
271 | ||
272 | bzero (opcode_chars, sizeof(opcode_chars)); | |
273 | bzero (operand_chars, sizeof(operand_chars)); | |
274 | bzero (space_chars, sizeof(space_chars)); | |
275 | bzero (identifier_chars, sizeof(identifier_chars)); | |
276 | bzero (digit_chars, sizeof(digit_chars)); | |
277 | ||
278 | for (c = 0; c < 256; c++) { | |
279 | if (islower(c) || isdigit(c)) { | |
280 | opcode_chars[c] = c; | |
281 | register_chars[c] = c; | |
282 | } else if (isupper(c)) { | |
283 | opcode_chars[c] = tolower(c); | |
284 | register_chars[c] = opcode_chars[c]; | |
285 | } else if (c == PREFIX_SEPERATOR) { | |
286 | opcode_chars[c] = c; | |
287 | } else if (c == ')' || c == '(') { | |
288 | register_chars[c] = c; | |
289 | } | |
290 | ||
291 | if (isupper(c) || islower(c) || isdigit(c)) | |
292 | operand_chars[c] = c; | |
293 | else if (c && index(operand_special_chars, c)) | |
294 | operand_chars[c] = c; | |
295 | ||
296 | if (isdigit(c) || c == '-') digit_chars[c] = c; | |
297 | ||
298 | if (isalpha(c) || c == '_' || c == '.' || isdigit(c)) | |
299 | identifier_chars[c] = c; | |
300 | ||
301 | if (c == ' ' || c == '\t') space_chars[c] = c; | |
302 | } | |
303 | } | |
304 | } | |
305 | ||
306 | void md_end() {} /* not much to do here. */ | |
307 | ||
308 | \f | |
309 | #ifdef DEBUG386 | |
310 | ||
311 | /* debugging routines for md_assemble */ | |
312 | static void pi (), pte (), pt (), pe (), ps (); | |
313 | ||
314 | static void pi (line, x) | |
315 | char * line; | |
316 | i386_insn *x; | |
317 | { | |
318 | register template *p; | |
319 | int i; | |
320 | ||
321 | fprintf (stdout, "%s: template ", line); | |
322 | pte (&x->tm); | |
323 | fprintf (stdout, " modrm: mode %x reg %x reg/mem %x", | |
324 | x->rm.mode, x->rm.reg, x->rm.regmem); | |
325 | fprintf (stdout, " base %x index %x scale %x\n", | |
326 | x->bi.base, x->bi.index, x->bi.scale); | |
327 | for (i = 0; i < x->operands; i++) { | |
328 | fprintf (stdout, " #%d: ", i+1); | |
329 | pt (x->types[i]); | |
330 | fprintf (stdout, "\n"); | |
331 | if (x->types[i] & Reg) fprintf (stdout, "%s\n", x->regs[i]->reg_name); | |
332 | if (x->types[i] & Imm) pe (x->imms[i]); | |
333 | if (x->types[i] & (Disp|Abs)) pe (x->disps[i]); | |
334 | } | |
335 | } | |
336 | ||
337 | static void pte (t) | |
338 | template *t; | |
339 | { | |
340 | int i; | |
341 | fprintf (stdout, " %d operands ", t->operands); | |
342 | fprintf (stdout, "opcode %x ", | |
343 | t->base_opcode); | |
344 | if (t->extension_opcode != None) | |
345 | fprintf (stdout, "ext %x ", t->extension_opcode); | |
346 | if (t->opcode_modifier&D) | |
347 | fprintf (stdout, "D"); | |
348 | if (t->opcode_modifier&W) | |
349 | fprintf (stdout, "W"); | |
350 | fprintf (stdout, "\n"); | |
351 | for (i = 0; i < t->operands; i++) { | |
352 | fprintf (stdout, " #%d type ", i+1); | |
353 | pt (t->operand_types[i]); | |
354 | fprintf (stdout, "\n"); | |
355 | } | |
356 | } | |
357 | ||
358 | char *seg_names[] = { | |
359 | "SEG_ABSOLUTE", "SEG_TEXT", "SEG_DATA", "SEG_BSS", "SEG_UNKNOWN", | |
360 | "SEG_NONE", "SEG_PASS1", "SEG_GOOF", "SEG_BIG", "SEG_DIFFERENCE" }; | |
361 | ||
362 | static void pe (e) | |
363 | expressionS *e; | |
364 | { | |
365 | fprintf (stdout, " segment %s\n", seg_names[(int) e->X_seg]); | |
366 | fprintf (stdout, " add_number %d (%x)\n", | |
367 | e->X_add_number, e->X_add_number); | |
368 | if (e->X_add_symbol) { | |
369 | fprintf (stdout, " add_symbol "); | |
370 | ps (e->X_add_symbol); | |
371 | fprintf (stdout, "\n"); | |
372 | } | |
373 | if (e->X_subtract_symbol) { | |
374 | fprintf (stdout, " sub_symbol "); | |
375 | ps (e->X_subtract_symbol); | |
376 | fprintf (stdout, "\n"); | |
377 | } | |
378 | } | |
379 | ||
380 | #define SYMBOL_TYPE(t) \ | |
381 | (((t&N_TYPE) == N_UNDF) ? "UNDEFINED" : \ | |
382 | (((t&N_TYPE) == N_ABS) ? "ABSOLUTE" : \ | |
383 | (((t&N_TYPE) == N_TEXT) ? "TEXT" : \ | |
384 | (((t&N_TYPE) == N_DATA) ? "DATA" : \ | |
385 | (((t&N_TYPE) == N_BSS) ? "BSS" : "Bad n_type!"))))) | |
386 | ||
387 | static void ps (s) | |
388 | symbolS *s; | |
389 | { | |
390 | fprintf (stdout, "%s type %s%s", | |
391 | s->sy_nlist.n_un.n_name, | |
392 | (s->sy_nlist.n_type&N_EXT) ? "EXTERNAL " : "", | |
393 | SYMBOL_TYPE (s->sy_nlist.n_type)); | |
394 | } | |
395 | ||
396 | struct type_name { | |
397 | uint mask; | |
398 | char *tname; | |
399 | } type_names[] = { | |
400 | { Reg8, "r8" }, { Reg16, "r16" }, { Reg32, "r32" }, { Imm8, "i8" }, | |
401 | { Imm8S, "i8s" }, | |
402 | { Imm16, "i16" }, { Imm32, "i32" }, { Mem8, "Mem8"}, { Mem16, "Mem16"}, | |
403 | { Mem32, "Mem32"}, { BaseIndex, "BaseIndex" }, | |
404 | { Abs8, "Abs8" }, { Abs16, "Abs16" }, { Abs32, "Abs32" }, | |
405 | { Disp8, "d8" }, { Disp16, "d16" }, | |
406 | { Disp32, "d32" }, { SReg2, "SReg2" }, { SReg3, "SReg3" }, { Acc, "Acc" }, | |
407 | { InOutPortReg, "InOutPortReg" }, { ShiftCount, "ShiftCount" }, | |
408 | { Imm1, "i1" }, { Control, "control reg" }, {Test, "test reg"}, | |
409 | { FloatReg, "FReg"}, {FloatAcc, "FAcc"}, | |
410 | { JumpAbsolute, "Jump Absolute"}, | |
411 | { 0, "" } | |
412 | }; | |
413 | ||
414 | static void pt (t) | |
415 | uint t; | |
416 | { | |
417 | register struct type_name *ty; | |
418 | ||
419 | if (t == Unknown) { | |
420 | fprintf (stdout, "Unknown"); | |
421 | } else { | |
422 | for (ty = type_names; ty->mask; ty++) | |
423 | if (t & ty->mask) fprintf (stdout, "%s, ", ty->tname); | |
424 | } | |
425 | fflush (stdout); | |
426 | } | |
427 | ||
428 | #endif /* DEBUG386 */ | |
429 | \f | |
430 | /* | |
431 | This is the guts of the machine-dependent assembler. LINE points to a | |
432 | machine dependent instruction. This funciton is supposed to emit | |
433 | the frags/bytes it assembles to. | |
434 | */ | |
435 | void md_assemble (line) | |
436 | char *line; | |
437 | { | |
438 | /* Holds temlate once we've found it. */ | |
439 | register template * t; | |
440 | ||
441 | /* Possible templates for current insn */ | |
442 | templates *current_templates = (templates *) 0; | |
443 | ||
444 | /* Initialize globals. */ | |
445 | bzero (&i, sizeof(i)); | |
446 | bzero (disp_expressions, sizeof(disp_expressions)); | |
447 | bzero (im_expressions, sizeof(im_expressions)); | |
448 | save_stack_p = save_stack; /* reset stack pointer */ | |
449 | ||
450 | /* Fist parse an opcode & call i386_operand for the operands. | |
451 | We assume that the scrubber has arranged it so that line[0] is the valid | |
452 | start of a (possibly prefixed) opcode. */ | |
453 | { | |
454 | register char *l = line; /* Fast place to put LINE. */ | |
455 | ||
456 | /* TRUE if operand is pending after ','. */ | |
457 | uint expecting_operand = 0; | |
458 | /* TRUE if we found a prefix only acceptable with string insns. */ | |
459 | uint expecting_string_instruction = 0; | |
460 | /* Non-zero if operand parens not balenced. */ | |
461 | uint paren_not_balenced; | |
462 | char * token_start = l; | |
463 | ||
464 | while (! is_space_char(*l) && *l != END_OF_INSN) { | |
465 | if (! is_opcode_char(*l)) { | |
466 | as_bad ("invalid character %s in opcode", output_invalid(*l)); | |
467 | return; | |
468 | } else if (*l != PREFIX_SEPERATOR) { | |
469 | *l = opcode_chars[(unsigned char) *l]; /* fold case of opcodes */ | |
470 | l++; | |
471 | } else { /* this opcode's got a prefix */ | |
472 | register int q; | |
473 | register prefix_entry * prefix; | |
474 | ||
475 | if (l == token_start) { | |
476 | as_bad ("expecting prefix; got nothing"); | |
477 | return; | |
478 | } | |
479 | END_STRING_AND_SAVE (l); | |
480 | prefix = (prefix_entry *) hash_find (prefix_hash, token_start); | |
481 | if (! prefix) { | |
482 | as_bad ("no such opcode prefix ('%s')", token_start); | |
483 | return; | |
484 | } | |
485 | RESTORE_END_STRING (l); | |
486 | /* check for repeated prefix */ | |
487 | for (q = 0; q < i.prefixes; q++) | |
488 | if (i.prefix[q] == prefix->prefix_code) { | |
489 | as_bad ("same prefix used twice; you don't really want this!"); | |
490 | return; | |
491 | } | |
492 | if (i.prefixes == MAX_PREFIXES) { | |
493 | as_bad ("too many opcode prefixes"); | |
494 | return; | |
495 | } | |
496 | i.prefix[i.prefixes++] = prefix->prefix_code; | |
497 | if (prefix->prefix_code == REPE || prefix->prefix_code == REPNE) | |
498 | expecting_string_instruction = TRUE; | |
499 | /* skip past PREFIX_SEPERATOR and reset token_start */ | |
500 | token_start = ++l; | |
501 | } | |
502 | } | |
503 | END_STRING_AND_SAVE (l); | |
504 | if (token_start == l) { | |
505 | as_bad ("expecting opcode; got nothing"); | |
506 | return; | |
507 | } | |
508 | ||
509 | /* Lookup insn in hash; try intel & att naming conventions if appropriate; | |
510 | that is: we only use the opcode suffix 'b' 'w' or 'l' if we need to. */ | |
511 | current_templates = (templates *) hash_find (op_hash, token_start); | |
512 | if (! current_templates) { | |
513 | int last_index = strlen(token_start) - 1; | |
514 | char last_char = token_start[last_index]; | |
515 | switch (last_char) { | |
516 | case DWORD_OPCODE_SUFFIX: | |
517 | case WORD_OPCODE_SUFFIX: | |
518 | case BYTE_OPCODE_SUFFIX: | |
519 | token_start[last_index] = '\0'; | |
520 | current_templates = (templates *) hash_find (op_hash, token_start); | |
521 | token_start[last_index] = last_char; | |
522 | i.suffix = last_char; | |
523 | } | |
524 | if (!current_templates) { | |
525 | as_bad ("no such 386 instruction: `%s'", token_start); return; | |
526 | } | |
527 | } | |
528 | RESTORE_END_STRING (l); | |
529 | ||
530 | /* check for rep/repne without a string instruction */ | |
531 | if (expecting_string_instruction && | |
532 | ! IS_STRING_INSTRUCTION (current_templates-> | |
533 | start->base_opcode)) { | |
534 | as_bad ("expecting string instruction after rep/repne"); | |
535 | return; | |
536 | } | |
537 | ||
538 | /* There may be operands to parse. */ | |
539 | if (*l != END_OF_INSN && | |
540 | /* For string instructions, we ignore any operands if given. This | |
541 | kludges, for example, 'rep/movsb %ds:(%esi), %es:(%edi)' where | |
542 | the operands are always going to be the same, and are not really | |
543 | encoded in machine code. */ | |
544 | ! IS_STRING_INSTRUCTION (current_templates-> | |
545 | start->base_opcode)) { | |
546 | /* parse operands */ | |
547 | do { | |
548 | /* skip optional white space before operand */ | |
549 | while (! is_operand_char(*l) && *l != END_OF_INSN) { | |
550 | if (! is_space_char(*l)) { | |
551 | as_bad ("invalid character %s before %s operand", | |
552 | output_invalid(*l), | |
553 | ordinal_names[i.operands]); | |
554 | return; | |
555 | } | |
556 | l++; | |
557 | } | |
558 | token_start = l; /* after white space */ | |
559 | paren_not_balenced = 0; | |
560 | while (paren_not_balenced || *l != ',') { | |
561 | if (*l == END_OF_INSN) { | |
562 | if (paren_not_balenced) { | |
563 | as_bad ("unbalenced parenthesis in %s operand.", | |
564 | ordinal_names[i.operands]); | |
565 | return; | |
566 | } else break; /* we are done */ | |
567 | } else if (! is_operand_char(*l)) { | |
568 | as_bad ("invalid character %s in %s operand", | |
569 | output_invalid(*l), | |
570 | ordinal_names[i.operands]); | |
571 | return; | |
572 | } | |
573 | if (*l == '(') ++paren_not_balenced; | |
574 | if (*l == ')') --paren_not_balenced; | |
575 | l++; | |
576 | } | |
577 | if (l != token_start) { /* yes, we've read in another operand */ | |
578 | uint operand_ok; | |
579 | this_operand = i.operands++; | |
580 | if (i.operands > MAX_OPERANDS) { | |
581 | as_bad ("spurious operands; (%d operands/instruction max)", | |
582 | MAX_OPERANDS); | |
583 | return; | |
584 | } | |
585 | /* now parse operand adding info to 'i' as we go along */ | |
586 | END_STRING_AND_SAVE (l); | |
587 | operand_ok = i386_operand (token_start); | |
588 | RESTORE_END_STRING (l); /* restore old contents */ | |
589 | if (!operand_ok) return; | |
590 | } else { | |
591 | if (expecting_operand) { | |
592 | expecting_operand_after_comma: | |
593 | as_bad ("expecting operand after ','; got nothing"); | |
594 | return; | |
595 | } | |
596 | if (*l == ',') { | |
597 | as_bad ("expecting operand before ','; got nothing"); | |
598 | return; | |
599 | } | |
600 | } | |
601 | ||
602 | /* now *l must be either ',' or END_OF_INSN */ | |
603 | if (*l == ',') { | |
604 | if (*++l == END_OF_INSN) { /* just skip it, if it's \n complain */ | |
605 | goto expecting_operand_after_comma; | |
606 | } | |
607 | expecting_operand = TRUE; | |
608 | } | |
609 | } while (*l != END_OF_INSN); /* until we get end of insn */ | |
610 | } | |
611 | } | |
612 | ||
613 | /* Now we've parsed the opcode into a set of templates, and have the | |
614 | operands at hand. | |
615 | Next, we find a template that matches the given insn, | |
616 | making sure the overlap of the given operands types is consistent | |
617 | with the template operand types. */ | |
618 | ||
619 | #define MATCH(overlap,given_type) \ | |
620 | (overlap && \ | |
621 | (overlap & (JumpAbsolute|BaseIndex|Mem8)) \ | |
622 | == (given_type & (JumpAbsolute|BaseIndex|Mem8))) | |
623 | ||
624 | /* If m0 and m1 are register matches they must be consistent | |
625 | with the expected operand types t0 and t1. | |
626 | That is, if both m0 & m1 are register matches | |
627 | i.e. ( ((m0 & (Reg)) && (m1 & (Reg)) ) ? | |
628 | then, either 1. or 2. must be true: | |
629 | 1. the expected operand type register overlap is null: | |
630 | (t0 & t1 & Reg) == 0 | |
631 | AND | |
632 | the given register overlap is null: | |
633 | (m0 & m1 & Reg) == 0 | |
634 | 2. the expected operand type register overlap == the given | |
635 | operand type overlap: (t0 & t1 & m0 & m1 & Reg). | |
636 | */ | |
637 | #define CONSISTENT_REGISTER_MATCH(m0, m1, t0, t1) \ | |
638 | ( ((m0 & (Reg)) && (m1 & (Reg))) ? \ | |
639 | ( ((t0 & t1 & (Reg)) == 0 && (m0 & m1 & (Reg)) == 0) || \ | |
640 | ((t0 & t1) & (m0 & m1) & (Reg)) \ | |
641 | ) : 1) | |
642 | { | |
643 | register uint overlap0, overlap1; | |
644 | expressionS * exp; | |
645 | uint overlap2; | |
646 | uint found_reverse_match; | |
647 | ||
648 | overlap0 = overlap1 = overlap2 = found_reverse_match = 0; | |
649 | for (t = current_templates->start; | |
650 | t < current_templates->end; | |
651 | t++) { | |
652 | ||
653 | /* must have right number of operands */ | |
654 | if (i.operands != t->operands) continue; | |
655 | else if (!t->operands) break; /* 0 operands always matches */ | |
656 | ||
657 | overlap0 = i.types[0] & t->operand_types[0]; | |
658 | switch (t->operands) { | |
659 | case 1: | |
660 | if (! MATCH (overlap0,i.types[0])) continue; | |
661 | break; | |
662 | case 2: case 3: | |
663 | overlap1 = i.types[1] & t->operand_types[1]; | |
664 | if (! MATCH (overlap0,i.types[0]) || | |
665 | ! MATCH (overlap1,i.types[1]) || | |
666 | ! CONSISTENT_REGISTER_MATCH(overlap0, overlap1, | |
667 | t->operand_types[0], | |
668 | t->operand_types[1])) { | |
669 | ||
670 | /* check if other direction is valid ... */ | |
671 | if (! (t->opcode_modifier & COMES_IN_BOTH_DIRECTIONS)) | |
672 | continue; | |
673 | ||
674 | /* try reversing direction of operands */ | |
675 | overlap0 = i.types[0] & t->operand_types[1]; | |
676 | overlap1 = i.types[1] & t->operand_types[0]; | |
677 | if (! MATCH (overlap0,i.types[0]) || | |
678 | ! MATCH (overlap1,i.types[1]) || | |
679 | ! CONSISTENT_REGISTER_MATCH (overlap0, overlap1, | |
680 | t->operand_types[0], | |
681 | t->operand_types[1])) { | |
682 | /* does not match either direction */ | |
683 | continue; | |
684 | } | |
685 | /* found a reverse match here -- slip through */ | |
686 | /* found_reverse_match holds which of D or FloatD we've found */ | |
687 | found_reverse_match = t->opcode_modifier & COMES_IN_BOTH_DIRECTIONS; | |
688 | } /* endif: not forward match */ | |
689 | /* found either forward/reverse 2 operand match here */ | |
690 | if (t->operands == 3) { | |
691 | overlap2 = i.types[2] & t->operand_types[2]; | |
692 | if (! MATCH (overlap2,i.types[2]) || | |
693 | ! CONSISTENT_REGISTER_MATCH (overlap0, overlap2, | |
694 | t->operand_types[0], | |
695 | t->operand_types[2]) || | |
696 | ! CONSISTENT_REGISTER_MATCH (overlap1, overlap2, | |
697 | t->operand_types[1], | |
698 | t->operand_types[2])) | |
699 | continue; | |
700 | } | |
701 | /* found either forward/reverse 2 or 3 operand match here: | |
702 | slip through to break */ | |
703 | } | |
704 | break; /* we've found a match; break out of loop */ | |
705 | } /* for (t = ... */ | |
706 | if (t == current_templates->end) { /* we found no match */ | |
707 | as_bad ("operands given don't match any known 386 instruction"); | |
708 | return; | |
709 | } | |
710 | ||
711 | /* Copy the template we found (we may change it!). */ | |
712 | bcopy (t, &i.tm, sizeof (template)); | |
713 | t = &i.tm; /* alter new copy of template */ | |
714 | ||
715 | /* If there's no opcode suffix we try to invent one based on register | |
716 | operands. */ | |
717 | if (! i.suffix && i.reg_operands) { | |
718 | /* We take i.suffix from the LAST register operand specified. This | |
719 | assumes that the last register operands is the destination register | |
720 | operand. */ | |
721 | int o; | |
722 | for (o = 0; o < MAX_OPERANDS; o++) | |
723 | if (i.types[o] & Reg) { | |
724 | i.suffix = (i.types[o] == Reg8) ? BYTE_OPCODE_SUFFIX : | |
725 | (i.types[o] == Reg16) ? WORD_OPCODE_SUFFIX : | |
726 | DWORD_OPCODE_SUFFIX; | |
727 | } | |
728 | } | |
729 | ||
730 | /* Make still unresolved immediate matches conform to size of immediate | |
731 | given in i.suffix. Note: overlap2 cannot be an immediate! | |
732 | We assume this. */ | |
733 | if ((overlap0 & (Imm8|Imm8S|Imm16|Imm32)) | |
734 | && overlap0 != Imm8 && overlap0 != Imm8S | |
735 | && overlap0 != Imm16 && overlap0 != Imm32) { | |
736 | if (! i.suffix) { | |
737 | as_bad ("no opcode suffix given; can't determine immediate size"); | |
738 | return; | |
739 | } | |
740 | overlap0 &= (i.suffix == BYTE_OPCODE_SUFFIX ? (Imm8|Imm8S) : | |
741 | (i.suffix == WORD_OPCODE_SUFFIX ? Imm16 : Imm32)); | |
742 | } | |
743 | if ((overlap1 & (Imm8|Imm8S|Imm16|Imm32)) | |
744 | && overlap1 != Imm8 && overlap1 != Imm8S | |
745 | && overlap1 != Imm16 && overlap1 != Imm32) { | |
746 | if (! i.suffix) { | |
747 | as_bad ("no opcode suffix given; can't determine immediate size"); | |
748 | return; | |
749 | } | |
750 | overlap1 &= (i.suffix == BYTE_OPCODE_SUFFIX ? (Imm8|Imm8S) : | |
751 | (i.suffix == WORD_OPCODE_SUFFIX ? Imm16 : Imm32)); | |
752 | } | |
753 | ||
754 | i.types[0] = overlap0; | |
755 | i.types[1] = overlap1; | |
756 | i.types[2] = overlap2; | |
757 | ||
758 | if (overlap0 & ImplicitRegister) i.reg_operands--; | |
759 | if (overlap1 & ImplicitRegister) i.reg_operands--; | |
760 | if (overlap2 & ImplicitRegister) i.reg_operands--; | |
761 | if (overlap0 & Imm1) i.imm_operands = 0; /* kludge for shift insns */ | |
762 | ||
763 | if (found_reverse_match) { | |
764 | uint save; | |
765 | save = t->operand_types[0]; | |
766 | t->operand_types[0] = t->operand_types[1]; | |
767 | t->operand_types[1] = save; | |
768 | } | |
769 | ||
770 | /* Finalize opcode. First, we change the opcode based on the operand | |
771 | size given by i.suffix: we never have to change things for byte insns, | |
772 | or when no opcode suffix is need to size the operands. */ | |
773 | ||
774 | if (! i.suffix && (t->opcode_modifier & W)) { | |
775 | as_bad ("no opcode suffix given and no register operands; can't size instruction"); | |
776 | return; | |
777 | } | |
778 | ||
779 | if (i.suffix && i.suffix != BYTE_OPCODE_SUFFIX) { | |
780 | /* Select between byte and word/dword operations. */ | |
781 | if (t->opcode_modifier & W) | |
782 | t->base_opcode |= W; | |
783 | /* Now select between word & dword operations via the | |
784 | operand size prefix. */ | |
785 | if (i.suffix == WORD_OPCODE_SUFFIX) { | |
786 | if (i.prefixes == MAX_PREFIXES) { | |
787 | as_bad ("%d prefixes given and 'w' opcode suffix gives too many prefixes", | |
788 | MAX_PREFIXES); | |
789 | return; | |
790 | } | |
791 | i.prefix[i.prefixes++] = WORD_PREFIX_OPCODE; | |
792 | } | |
793 | } | |
794 | ||
795 | /* For insns with operands there are more diddles to do to the opcode. */ | |
796 | if (i.operands) { | |
797 | /* If we found a reverse match we must alter the opcode direction bit | |
798 | found_reverse_match holds bit to set (different for int & | |
799 | float insns). */ | |
800 | ||
801 | if (found_reverse_match) { | |
802 | t->base_opcode |= found_reverse_match; | |
803 | } | |
804 | ||
805 | /* | |
806 | The imul $imm, %reg instruction is converted into | |
807 | imul $imm, %reg, %reg. */ | |
808 | if (t->opcode_modifier & imulKludge) { | |
809 | i.regs[2] = i.regs[1]; /* Pretend we saw the 3 operand case. */ | |
810 | i.reg_operands = 2; | |
811 | } | |
812 | ||
813 | /* Certain instructions expect the destination to be in the i.rm.reg | |
814 | field. This is by far the exceptional case. For these instructions, | |
815 | if the source operand is a register, we must reverse the i.rm.reg | |
816 | and i.rm.regmem fields. We accomplish this by faking that the | |
817 | two register operands were given in the reverse order. */ | |
818 | if ((t->opcode_modifier & ReverseRegRegmem) && i.reg_operands == 2) { | |
819 | uint first_reg_operand = (i.types[0] & Reg) ? 0 : 1; | |
820 | uint second_reg_operand = first_reg_operand + 1; | |
821 | reg_entry *tmp = i.regs[first_reg_operand]; | |
822 | i.regs[first_reg_operand] = i.regs[second_reg_operand]; | |
823 | i.regs[second_reg_operand] = tmp; | |
824 | } | |
825 | ||
826 | if (t->opcode_modifier & ShortForm) { | |
827 | /* The register or float register operand is in operand 0 or 1. */ | |
828 | uint o = (i.types[0] & (Reg|FloatReg)) ? 0 : 1; | |
829 | /* Register goes in low 3 bits of opcode. */ | |
830 | t->base_opcode |= i.regs[o]->reg_num; | |
831 | } else if (t->opcode_modifier & ShortFormW) { | |
832 | /* Short form with 0x8 width bit. Register is always dest. operand */ | |
833 | t->base_opcode |= i.regs[1]->reg_num; | |
834 | if (i.suffix == WORD_OPCODE_SUFFIX || | |
835 | i.suffix == DWORD_OPCODE_SUFFIX) | |
836 | t->base_opcode |= 0x8; | |
837 | } else if (t->opcode_modifier & Seg2ShortForm) { | |
838 | if (t->base_opcode == POP_SEG_SHORT && i.regs[0]->reg_num == 1) { | |
839 | as_bad ("you can't 'pop cs' on the 386."); | |
840 | return; | |
841 | } | |
842 | t->base_opcode |= (i.regs[0]->reg_num << 3); | |
843 | } else if (t->opcode_modifier & Seg3ShortForm) { | |
844 | /* 'push %fs' is 0x0fa0; 'pop %fs' is 0x0fa1. | |
845 | 'push %gs' is 0x0fa8; 'pop %fs' is 0x0fa9. | |
846 | So, only if i.regs[0]->reg_num == 5 (%gs) do we need | |
847 | to change the opcode. */ | |
848 | if (i.regs[0]->reg_num == 5) | |
849 | t->base_opcode |= 0x08; | |
850 | } else if (t->opcode_modifier & Modrm) { | |
851 | /* The opcode is completed (modulo t->extension_opcode which must | |
852 | be put into the modrm byte. | |
853 | Now, we make the modrm & index base bytes based on all the info | |
854 | we've collected. */ | |
855 | ||
856 | /* i.reg_operands MUST be the number of real register operands; | |
857 | implicit registers do not count. */ | |
858 | if (i.reg_operands == 2) { | |
859 | uint source, dest; | |
860 | source = (i.types[0] & (Reg|SReg2|SReg3|Control|Debug|Test)) ? 0 : 1; | |
861 | dest = source + 1; | |
862 | i.rm.mode = 3; | |
863 | /* We must be careful to make sure that all segment/control/test/ | |
864 | debug registers go into the i.rm.reg field (despite the whether | |
865 | they are source or destination operands). */ | |
866 | if (i.regs[dest]->reg_type & (SReg2|SReg3|Control|Debug|Test)) { | |
867 | i.rm.reg = i.regs[dest]->reg_num; | |
868 | i.rm.regmem = i.regs[source]->reg_num; | |
869 | } else { | |
870 | i.rm.reg = i.regs[source]->reg_num; | |
871 | i.rm.regmem = i.regs[dest]->reg_num; | |
872 | } | |
873 | } else { /* if it's not 2 reg operands... */ | |
874 | if (i.mem_operands) { | |
875 | uint fake_zero_displacement = FALSE; | |
876 | uint o = (i.types[0] & Mem) ? 0 : ((i.types[1] & Mem) ? 1 : 2); | |
877 | ||
878 | /* Encode memory operand into modrm byte and base index byte. */ | |
879 | ||
880 | if (i.base_reg == esp && ! i.index_reg) { | |
881 | /* <disp>(%esp) becomes two byte modrm with no index register. */ | |
882 | i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING; | |
883 | i.rm.mode = MODE_FROM_DISP_SIZE (i.types[o]); | |
884 | i.bi.base = ESP_REG_NUM; | |
885 | i.bi.index = NO_INDEX_REGISTER; | |
886 | i.bi.scale = 0; /* Must be zero! */ | |
887 | } else if (i.base_reg == ebp && !i.index_reg) { | |
888 | if (! (i.types[o] & Disp)) { | |
889 | /* Must fake a zero byte displacement. | |
890 | There is no direct way to code '(%ebp)' directly. */ | |
891 | fake_zero_displacement = TRUE; | |
892 | /* fake_zero_displacement code does not set this. */ | |
893 | i.types[o] |= Disp8; | |
894 | } | |
895 | i.rm.mode = MODE_FROM_DISP_SIZE (i.types[o]); | |
896 | i.rm.regmem = EBP_REG_NUM; | |
897 | } else if (! i.base_reg && (i.types[o] & BaseIndex)) { | |
898 | /* There are three cases here. | |
899 | Case 1: '<32bit disp>(,1)' -- indirect absolute. | |
900 | (Same as cases 2 & 3 with NO index register) | |
901 | Case 2: <32bit disp> (,<index>) -- no base register with disp | |
902 | Case 3: (, <index>) --- no base register; | |
903 | no disp (must add 32bit 0 disp). */ | |
904 | i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING; | |
905 | i.rm.mode = 0; /* 32bit mode */ | |
906 | i.bi.base = NO_BASE_REGISTER; | |
907 | i.types[o] &= ~Disp; | |
908 | i.types[o] |= Disp32; /* Must be 32bit! */ | |
909 | if (i.index_reg) { /* case 2 or case 3 */ | |
910 | i.bi.index = i.index_reg->reg_num; | |
911 | i.bi.scale = i.log2_scale_factor; | |
912 | if (i.disp_operands == 0) | |
913 | fake_zero_displacement = TRUE; /* case 3 */ | |
914 | } else { | |
915 | i.bi.index = NO_INDEX_REGISTER; | |
916 | i.bi.scale = 0; | |
917 | } | |
918 | } else if (i.disp_operands && !i.base_reg && !i.index_reg) { | |
919 | /* Operand is just <32bit disp> */ | |
920 | i.rm.regmem = EBP_REG_NUM; | |
921 | i.rm.mode = 0; | |
922 | i.types[o] &= ~Disp; | |
923 | i.types[o] |= Disp32; | |
924 | } else { | |
925 | /* It's not a special case; rev'em up. */ | |
926 | i.rm.regmem = i.base_reg->reg_num; | |
927 | i.rm.mode = MODE_FROM_DISP_SIZE (i.types[o]); | |
928 | if (i.index_reg) { | |
929 | i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING; | |
930 | i.bi.base = i.base_reg->reg_num; | |
931 | i.bi.index = i.index_reg->reg_num; | |
932 | i.bi.scale = i.log2_scale_factor; | |
933 | if (i.base_reg == ebp && i.disp_operands == 0) { /* pace */ | |
934 | fake_zero_displacement = TRUE; | |
935 | i.types[o] |= Disp8; | |
936 | i.rm.mode = MODE_FROM_DISP_SIZE (i.types[o]); | |
937 | } | |
938 | } | |
939 | } | |
940 | if (fake_zero_displacement) { | |
941 | /* Fakes a zero displacement assuming that i.types[o] holds | |
942 | the correct displacement size. */ | |
943 | exp = &disp_expressions[i.disp_operands++]; | |
944 | i.disps[o] = exp; | |
945 | exp->X_seg = SEG_ABSOLUTE; | |
946 | exp->X_add_number = 0; | |
947 | exp->X_add_symbol = (symbolS *) 0; | |
948 | exp->X_subtract_symbol = (symbolS *) 0; | |
949 | } | |
950 | ||
951 | /* Select the correct segment for the memory operand. */ | |
952 | if (i.seg) { | |
953 | uint seg_index; | |
954 | seg_entry * default_seg; | |
955 | ||
956 | if (i.rm.regmem == ESCAPE_TO_TWO_BYTE_ADDRESSING) { | |
957 | seg_index = (i.rm.mode<<3) | i.bi.base; | |
958 | default_seg = two_byte_segment_defaults [seg_index]; | |
959 | } else { | |
960 | seg_index = (i.rm.mode<<3) | i.rm.regmem; | |
961 | default_seg = one_byte_segment_defaults [seg_index]; | |
962 | } | |
963 | /* If the specified segment is not the default, use an | |
964 | opcode prefix to select it */ | |
965 | if (i.seg != default_seg) { | |
966 | if (i.prefixes == MAX_PREFIXES) { | |
967 | as_bad ("%d prefixes given and %s segment override gives too many prefixes", | |
968 | MAX_PREFIXES, i.seg->seg_name); | |
969 | return; | |
970 | } | |
971 | i.prefix[i.prefixes++] = i.seg->seg_prefix; | |
972 | } | |
973 | } | |
974 | } | |
975 | ||
976 | /* Fill in i.rm.reg or i.rm.regmem field with register operand | |
977 | (if any) based on t->extension_opcode. Again, we must be careful | |
978 | to make sure that segment/control/debug/test registers are coded | |
979 | into the i.rm.reg field. */ | |
980 | if (i.reg_operands) { | |
981 | uint o = | |
982 | (i.types[0] & (Reg|SReg2|SReg3|Control|Debug|Test)) ? 0 : | |
983 | (i.types[1] & (Reg|SReg2|SReg3|Control|Debug|Test)) ? 1 : 2; | |
984 | /* If there is an extension opcode to put here, the register number | |
985 | must be put into the regmem field. */ | |
986 | if (t->extension_opcode != None) | |
987 | i.rm.regmem = i.regs[o]->reg_num; | |
988 | else i.rm.reg = i.regs[o]->reg_num; | |
989 | ||
990 | /* Now, if no memory operand has set i.rm.mode = 0, 1, 2 | |
991 | we must set it to 3 to indicate this is a register operand | |
992 | int the regmem field */ | |
993 | if (! i.mem_operands) i.rm.mode = 3; | |
994 | } | |
995 | ||
996 | /* Fill in i.rm.reg field with extension opcode (if any). */ | |
997 | if (t->extension_opcode != None) | |
998 | i.rm.reg = t->extension_opcode; | |
999 | } | |
1000 | } | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | /* Handle conversion of 'int $3' --> special int3 insn. */ | |
1005 | if (t->base_opcode == INT_OPCODE && i.imms[0]->X_add_number == 3) { | |
1006 | t->base_opcode = INT3_OPCODE; | |
1007 | i.imm_operands = 0; | |
1008 | } | |
1009 | ||
1010 | /* We are ready to output the insn. */ | |
1011 | { | |
1012 | register char * p; | |
1013 | ||
1014 | /* Output jumps. */ | |
1015 | if (t->opcode_modifier & Jump) { | |
1016 | int n = i.disps[0]->X_add_number; | |
1017 | ||
1018 | switch (i.disps[0]->X_seg) { | |
1019 | case SEG_ABSOLUTE: | |
1020 | if (FITS_IN_SIGNED_BYTE (n)) { | |
1021 | p = frag_more (2); | |
1022 | p[0] = t->base_opcode; | |
1023 | p[1] = n; | |
1024 | #if 0 /* leave out 16 bit jumps - pace */ | |
1025 | } else if (FITS_IN_SIGNED_WORD (n)) { | |
1026 | p = frag_more (4); | |
1027 | p[0] = WORD_PREFIX_OPCODE; | |
1028 | p[1] = t->base_opcode; | |
1029 | md_number_to_chars (&p[2], n, 2); | |
1030 | #endif | |
1031 | } else { /* It's an absolute dword displacement. */ | |
1032 | if (t->base_opcode == JUMP_PC_RELATIVE) { /* pace */ | |
1033 | /* unconditional jump */ | |
1034 | p = frag_more (5); | |
1035 | p[0] = 0xe9; | |
1036 | md_number_to_chars (&p[1], n, 4); | |
1037 | } else { | |
1038 | /* conditional jump */ | |
1039 | p = frag_more (6); | |
1040 | p[0] = TWO_BYTE_OPCODE_ESCAPE; | |
1041 | p[1] = t->base_opcode + 0x10; | |
1042 | md_number_to_chars (&p[2], n, 4); | |
1043 | } | |
1044 | } | |
1045 | break; | |
1046 | default: | |
1047 | /* It's a symbol; end frag & setup for relax. | |
1048 | Make sure there are 6 chars left in the current frag; if not | |
1049 | we'll have to start a new one. */ | |
1050 | /* I caught it failing with obstack_room == 6, | |
1051 | so I changed to <= pace */ | |
1052 | if (obstack_room (&frags) <= 6) { | |
1053 | frag_wane(frag_now); | |
1054 | frag_new (0); | |
1055 | } | |
1056 | p = frag_more (1); | |
1057 | p[0] = t->base_opcode; | |
1058 | frag_var (rs_machine_dependent, | |
1059 | 6, /* 2 opcode/prefix + 4 displacement */ | |
1060 | 1, | |
1061 | ((uchar) *p == JUMP_PC_RELATIVE | |
1062 | ? ENCODE_RELAX_STATE (UNCOND_JUMP, BYTE) | |
1063 | : ENCODE_RELAX_STATE (COND_JUMP, BYTE)), | |
1064 | i.disps[0]->X_add_symbol, | |
1065 | n, p); | |
1066 | break; | |
1067 | } | |
1068 | } else if (t->opcode_modifier & (JumpByte|JumpDword)) { | |
1069 | int size = (t->opcode_modifier & JumpByte) ? 1 : 4; | |
1070 | int n = i.disps[0]->X_add_number; | |
1071 | ||
1072 | if (FITS_IN_UNSIGNED_BYTE(t->base_opcode)) { | |
1073 | FRAG_APPEND_1_CHAR (t->base_opcode); | |
1074 | } else { | |
1075 | p = frag_more (2); /* opcode can be at most two bytes */ | |
1076 | /* put out high byte first: can't use md_number_to_chars! */ | |
1077 | *p++ = (t->base_opcode >> 8) & 0xff; | |
1078 | *p = t->base_opcode & 0xff; | |
1079 | } | |
1080 | ||
1081 | p = frag_more (size); | |
1082 | switch (i.disps[0]->X_seg) { | |
1083 | case SEG_ABSOLUTE: | |
1084 | md_number_to_chars (p, n, size); | |
1085 | if (size == 1 && ! FITS_IN_SIGNED_BYTE (n)) { | |
1086 | as_bad ("loop/jecx only takes byte displacement; %d shortened to %d", | |
1087 | n, *p); | |
1088 | } | |
1089 | break; | |
1090 | default: | |
1091 | fix_new (frag_now, p - frag_now->fr_literal, size, | |
1092 | i.disps[0]->X_add_symbol, i.disps[0]->X_subtract_symbol, | |
1093 | i.disps[0]->X_add_number, 1); | |
1094 | break; | |
1095 | } | |
1096 | } else if (t->opcode_modifier & JumpInterSegment) { | |
1097 | p = frag_more (1 + 2 + 4); /* 1 opcode; 2 segment; 4 offset */ | |
1098 | p[0] = t->base_opcode; | |
1099 | if (i.imms[1]->X_seg == SEG_ABSOLUTE) | |
1100 | md_number_to_chars (p + 1, i.imms[1]->X_add_number, 4); | |
1101 | else | |
1102 | fix_new (frag_now, p + 1 - frag_now->fr_literal, 4, | |
1103 | i.imms[1]->X_add_symbol, | |
1104 | i.imms[1]->X_subtract_symbol, | |
1105 | i.imms[1]->X_add_number, 0); | |
1106 | if (i.imms[0]->X_seg != SEG_ABSOLUTE) | |
1107 | as_bad ("can't handle non absolute segment in long call/jmp"); | |
1108 | md_number_to_chars (p + 5, i.imms[0]->X_add_number, 2); | |
1109 | } else { | |
1110 | /* Output normal instructions here. */ | |
1111 | register char *q; | |
1112 | ||
1113 | /* First the prefix bytes. */ | |
1114 | for (q = i.prefix; q < i.prefix + i.prefixes; q++) { | |
1115 | p = frag_more (1); | |
1116 | md_number_to_chars (p, (uint) *q, 1); | |
1117 | } | |
1118 | ||
1119 | /* Now the opcode; be careful about word order here! */ | |
1120 | if (FITS_IN_UNSIGNED_BYTE(t->base_opcode)) { | |
1121 | FRAG_APPEND_1_CHAR (t->base_opcode); | |
1122 | } else if (FITS_IN_UNSIGNED_WORD(t->base_opcode)) { | |
1123 | p = frag_more (2); | |
1124 | /* put out high byte first: can't use md_number_to_chars! */ | |
1125 | *p++ = (t->base_opcode >> 8) & 0xff; | |
1126 | *p = t->base_opcode & 0xff; | |
1127 | } else { /* opcode is either 3 or 4 bytes */ | |
1128 | if (t->base_opcode & 0xff000000) { | |
1129 | p = frag_more (4); | |
1130 | *p++ = (t->base_opcode >> 24) & 0xff; | |
1131 | } else p = frag_more (3); | |
1132 | *p++ = (t->base_opcode >> 16) & 0xff; | |
1133 | *p++ = (t->base_opcode >> 8) & 0xff; | |
1134 | *p = (t->base_opcode ) & 0xff; | |
1135 | } | |
1136 | ||
1137 | /* Now the modrm byte and base index byte (if present). */ | |
1138 | if (t->opcode_modifier & Modrm) { | |
1139 | p = frag_more (1); | |
1140 | /* md_number_to_chars (p, i.rm, 1); */ | |
1141 | md_number_to_chars (p, (i.rm.regmem<<0 | i.rm.reg<<3 | i.rm.mode<<6), 1); | |
1142 | /* If i.rm.regmem == ESP (4) && i.rm.mode != Mode 3 (Register mode) | |
1143 | ==> need second modrm byte. */ | |
1144 | if (i.rm.regmem == ESCAPE_TO_TWO_BYTE_ADDRESSING && i.rm.mode != 3) { | |
1145 | p = frag_more (1); | |
1146 | /* md_number_to_chars (p, i.bi, 1); */ | |
1147 | md_number_to_chars (p,(i.bi.base<<0 | i.bi.index<<3 | i.bi.scale<<6), 1); | |
1148 | } | |
1149 | } | |
1150 | ||
1151 | if (i.disp_operands) { | |
1152 | register int n; | |
1153 | ||
1154 | for (n = 0; n < i.operands; n++) { | |
1155 | if (i.disps[n]) { | |
1156 | if (i.disps[n]->X_seg == SEG_ABSOLUTE) { | |
1157 | if (i.types[n] & (Disp8|Abs8)) { | |
1158 | p = frag_more (1); | |
1159 | md_number_to_chars (p, i.disps[n]->X_add_number, 1); | |
1160 | } else if (i.types[n] & (Disp16|Abs16)) { | |
1161 | p = frag_more (2); | |
1162 | md_number_to_chars (p, i.disps[n]->X_add_number, 2); | |
1163 | } else { /* Disp32|Abs32 */ | |
1164 | p = frag_more (4); | |
1165 | md_number_to_chars (p, i.disps[n]->X_add_number, 4); | |
1166 | } | |
1167 | } else { /* not SEG_ABSOLUTE */ | |
1168 | /* need a 32-bit fixup (don't support 8bit non-absolute disps) */ | |
1169 | p = frag_more (4); | |
1170 | fix_new (frag_now, p - frag_now->fr_literal, 4, | |
1171 | i.disps[n]->X_add_symbol, i.disps[n]->X_subtract_symbol, | |
1172 | i.disps[n]->X_add_number, 0); | |
1173 | } | |
1174 | } | |
1175 | } | |
1176 | } /* end displacement output */ | |
1177 | ||
1178 | /* output immediate */ | |
1179 | if (i.imm_operands) { | |
1180 | register int n; | |
1181 | ||
1182 | for (n = 0; n < i.operands; n++) { | |
1183 | if (i.imms[n]) { | |
1184 | if (i.imms[n]->X_seg == SEG_ABSOLUTE) { | |
1185 | if (i.types[n] & (Imm8|Imm8S)) { | |
1186 | p = frag_more (1); | |
1187 | md_number_to_chars (p, i.imms[n]->X_add_number, 1); | |
1188 | } else if (i.types[n] & Imm16) { | |
1189 | p = frag_more (2); | |
1190 | md_number_to_chars (p, i.imms[n]->X_add_number, 2); | |
1191 | } else { | |
1192 | p = frag_more (4); | |
1193 | md_number_to_chars (p, i.imms[n]->X_add_number, 4); | |
1194 | } | |
1195 | } else { /* not SEG_ABSOLUTE */ | |
1196 | /* need a 32-bit fixup (don't support 8bit non-absolute ims) */ | |
1197 | /* try to support other sizes ... */ | |
1198 | int size; | |
1199 | if (i.types[n] & (Imm8|Imm8S)) | |
1200 | size = 1; | |
1201 | else if (i.types[n] & Imm16) | |
1202 | size = 2; | |
1203 | else | |
1204 | size = 4; | |
1205 | p = frag_more (size); | |
1206 | fix_new (frag_now, p - frag_now->fr_literal, size, | |
1207 | i.imms[n]->X_add_symbol, i.imms[n]->X_subtract_symbol, | |
1208 | i.imms[n]->X_add_number, 0); | |
1209 | } | |
1210 | } | |
1211 | } | |
1212 | } /* end immediate output */ | |
1213 | } | |
1214 | ||
1215 | #ifdef DEBUG386 | |
1216 | if (flagseen ['D']) { | |
1217 | pi (line, &i); | |
1218 | } | |
1219 | #endif /* DEBUG386 */ | |
1220 | ||
1221 | } | |
1222 | return; | |
1223 | } | |
1224 | \f | |
1225 | /* Parse OPERAND_STRING into the i386_insn structure I. Returns non-zero | |
1226 | on error. */ | |
1227 | ||
1228 | int i386_operand (operand_string) | |
1229 | char *operand_string; | |
1230 | { | |
1231 | register char *op_string = operand_string; | |
1232 | ||
1233 | /* Address of '\0' at end of operand_string. */ | |
1234 | char * end_of_operand_string = operand_string + strlen(operand_string); | |
1235 | ||
1236 | /* Start and end of displacement string expression (if found). */ | |
1237 | char * displacement_string_start = 0; | |
1238 | char * displacement_string_end; | |
1239 | ||
1240 | /* We check for an absolute prefix (differentiating, | |
1241 | for example, 'jmp pc_relative_label' from 'jmp *absolute_label'. */ | |
1242 | if (*op_string == ABSOLUTE_PREFIX) { | |
1243 | op_string++; | |
1244 | i.types[this_operand] |= JumpAbsolute; | |
1245 | } | |
1246 | ||
1247 | /* Check if operand is a register. */ | |
1248 | if (*op_string == REGISTER_PREFIX) { | |
1249 | register reg_entry * r; | |
1250 | if (! (r = parse_register (op_string))) { | |
1251 | as_bad ("bad register name ('%s')", op_string); | |
1252 | return 0; | |
1253 | } | |
1254 | /* Check for segment override, rather than segment register by | |
1255 | searching for ':' after %<x>s where <x> = s, c, d, e, f, g. */ | |
1256 | if ((r->reg_type & (SReg2|SReg3)) && op_string[3] == ':') { | |
1257 | switch (r->reg_num) { | |
1258 | case 0: | |
1259 | i.seg = &es; break; | |
1260 | case 1: | |
1261 | i.seg = &cs; break; | |
1262 | case 2: | |
1263 | i.seg = &ss; break; | |
1264 | case 3: | |
1265 | i.seg = &ds; break; | |
1266 | case 4: | |
1267 | i.seg = &fs; break; | |
1268 | case 5: | |
1269 | i.seg = &gs; break; | |
1270 | } | |
1271 | op_string += 4; /* skip % <x> s : */ | |
1272 | operand_string = op_string; /* Pretend given string starts here. */ | |
1273 | if (!is_digit_char(*op_string) && !is_identifier_char(*op_string) | |
1274 | && *op_string != '(' && *op_string != ABSOLUTE_PREFIX) { | |
1275 | as_bad ("bad memory operand after segment override"); | |
1276 | return 0; | |
1277 | } | |
1278 | /* Handle case of %es:*foo. */ | |
1279 | if (*op_string == ABSOLUTE_PREFIX) { | |
1280 | op_string++; | |
1281 | i.types[this_operand] |= JumpAbsolute; | |
1282 | } | |
1283 | goto do_memory_reference; | |
1284 | } | |
1285 | i.types[this_operand] |= r->reg_type; | |
1286 | i.regs[this_operand] = r; | |
1287 | i.reg_operands++; | |
1288 | } else if (*op_string == IMMEDIATE_PREFIX) { /* ... or an immediate */ | |
1289 | char * save_input_line_pointer; | |
1290 | register expressionS *exp; | |
1291 | segT exp_seg; | |
1292 | if (i.imm_operands == MAX_IMMEDIATE_OPERANDS) { | |
1293 | as_bad ("only 1 or 2 immediate operands are allowed"); | |
1294 | return 0; | |
1295 | } | |
1296 | exp = &im_expressions[i.imm_operands++]; | |
1297 | i.imms [this_operand] = exp; | |
1298 | save_input_line_pointer = input_line_pointer; | |
1299 | input_line_pointer = ++op_string; /* must advance op_string! */ | |
1300 | exp_seg = expression (exp); | |
1301 | input_line_pointer = save_input_line_pointer; | |
1302 | switch (exp_seg) { | |
1303 | case SEG_NONE: /* missing or bad expr becomes absolute 0 */ | |
1304 | as_bad ("missing or invalid immediate expression '%s' taken as 0", | |
1305 | operand_string); | |
1306 | exp->X_seg = SEG_ABSOLUTE; | |
1307 | exp->X_add_number = 0; | |
1308 | exp->X_add_symbol = (symbolS *) 0; | |
1309 | exp->X_subtract_symbol = (symbolS *) 0; | |
1310 | i.types[this_operand] |= Imm; | |
1311 | break; | |
1312 | case SEG_ABSOLUTE: | |
1313 | i.types[this_operand] |= SMALLEST_IMM_TYPE (exp->X_add_number); | |
1314 | break; | |
1315 | case SEG_TEXT: case SEG_DATA: case SEG_BSS: case SEG_UNKNOWN: | |
1316 | i.types[this_operand] |= Imm32; /* this is an address ==> 32bit */ | |
1317 | break; | |
1318 | default: | |
1319 | seg_unimplemented: | |
1320 | as_bad ("Unimplemented segment type %d in parse_operand", exp_seg); | |
1321 | return 0; | |
1322 | } | |
1323 | /* shorten this type of this operand if the instruction wants | |
1324 | * fewer bits than are present in the immediate. The bit field | |
1325 | * code can put out 'andb $0xffffff, %al', for example. pace | |
1326 | * also 'movw $foo,(%eax)' | |
1327 | */ | |
1328 | switch (i.suffix) { | |
1329 | case WORD_OPCODE_SUFFIX: | |
1330 | i.types[this_operand] |= Imm16; | |
1331 | break; | |
1332 | case BYTE_OPCODE_SUFFIX: | |
1333 | i.types[this_operand] |= Imm16 | Imm8 | Imm8S; | |
1334 | break; | |
1335 | } | |
1336 | } else if (is_digit_char(*op_string) || is_identifier_char(*op_string) | |
1337 | || *op_string == '(') { | |
1338 | /* This is a memory reference of some sort. */ | |
1339 | register char * base_string; | |
1340 | uint found_base_index_form; | |
1341 | ||
1342 | do_memory_reference: | |
1343 | if (i.mem_operands == MAX_MEMORY_OPERANDS) { | |
1344 | as_bad ("more than 1 memory reference in instruction"); | |
1345 | return 0; | |
1346 | } | |
1347 | i.mem_operands++; | |
1348 | ||
1349 | /* Determine type of memory operand from opcode_suffix; | |
1350 | no opcode suffix implies general memory references. */ | |
1351 | switch (i.suffix) { | |
1352 | case BYTE_OPCODE_SUFFIX: | |
1353 | i.types[this_operand] |= Mem8; | |
1354 | break; | |
1355 | case WORD_OPCODE_SUFFIX: | |
1356 | i.types[this_operand] |= Mem16; | |
1357 | break; | |
1358 | case DWORD_OPCODE_SUFFIX: | |
1359 | default: | |
1360 | i.types[this_operand] |= Mem32; | |
1361 | } | |
1362 | ||
1363 | /* Check for base index form. We detect the base index form by | |
1364 | looking for an ')' at the end of the operand, searching | |
1365 | for the '(' matching it, and finding a REGISTER_PREFIX or ',' | |
1366 | after it. */ | |
1367 | base_string = end_of_operand_string - 1; | |
1368 | found_base_index_form = FALSE; | |
1369 | if (*base_string == ')') { | |
1370 | uint parens_balenced = 1; | |
1371 | /* We've already checked that the number of left & right ()'s are equal, | |
1372 | so this loop will not be infinite. */ | |
1373 | do { | |
1374 | base_string--; | |
1375 | if (*base_string == ')') parens_balenced++; | |
1376 | if (*base_string == '(') parens_balenced--; | |
1377 | } while (parens_balenced); | |
1378 | base_string++; /* Skip past '('. */ | |
1379 | if (*base_string == REGISTER_PREFIX || *base_string == ',') | |
1380 | found_base_index_form = TRUE; | |
1381 | } | |
1382 | ||
1383 | /* If we can't parse a base index register expression, we've found | |
1384 | a pure displacement expression. We set up displacement_string_start | |
1385 | and displacement_string_end for the code below. */ | |
1386 | if (! found_base_index_form) { | |
1387 | displacement_string_start = op_string; | |
1388 | displacement_string_end = end_of_operand_string; | |
1389 | } else { | |
1390 | char *base_reg_name, *index_reg_name, *num_string; | |
1391 | int num; | |
1392 | ||
1393 | i.types[this_operand] |= BaseIndex; | |
1394 | ||
1395 | /* If there is a displacement set-up for it to be parsed later. */ | |
1396 | if (base_string != op_string + 1) { | |
1397 | displacement_string_start = op_string; | |
1398 | displacement_string_end = base_string - 1; | |
1399 | } | |
1400 | ||
1401 | /* Find base register (if any). */ | |
1402 | if (*base_string != ',') { | |
1403 | base_reg_name = base_string++; | |
1404 | /* skip past register name & parse it */ | |
1405 | while (isalpha(*base_string)) base_string++; | |
1406 | if (base_string == base_reg_name+1) { | |
1407 | as_bad ("can't find base register name after '(%c'", | |
1408 | REGISTER_PREFIX); | |
1409 | return 0; | |
1410 | } | |
1411 | END_STRING_AND_SAVE (base_string); | |
1412 | if (! (i.base_reg = parse_register (base_reg_name))) { | |
1413 | as_bad ("bad base register name ('%s')", base_reg_name); | |
1414 | return 0; | |
1415 | } | |
1416 | RESTORE_END_STRING (base_string); | |
1417 | } | |
1418 | ||
1419 | /* Now check seperator; must be ',' ==> index reg | |
1420 | OR num ==> no index reg. just scale factor | |
1421 | OR ')' ==> end. (scale factor = 1) */ | |
1422 | if (*base_string != ',' && *base_string != ')') { | |
1423 | as_bad ("expecting ',' or ')' after base register in `%s'", | |
1424 | operand_string); | |
1425 | return 0; | |
1426 | } | |
1427 | ||
1428 | /* There may index reg here; and there may be a scale factor. */ | |
1429 | if (*base_string == ',' && *(base_string+1) == REGISTER_PREFIX) { | |
1430 | index_reg_name = ++base_string; | |
1431 | while (isalpha(*++base_string)); | |
1432 | END_STRING_AND_SAVE (base_string); | |
1433 | if (! (i.index_reg = parse_register(index_reg_name))) { | |
1434 | as_bad ("bad index register name ('%s')", index_reg_name); | |
1435 | return 0; | |
1436 | } | |
1437 | RESTORE_END_STRING (base_string); | |
1438 | } | |
1439 | ||
1440 | /* Check for scale factor. */ | |
1441 | if (*base_string == ',' && isdigit(*(base_string+1))) { | |
1442 | num_string = ++base_string; | |
1443 | while (is_digit_char(*base_string)) base_string++; | |
1444 | if (base_string == num_string) { | |
1445 | as_bad ("can't find a scale factor after ','"); | |
1446 | return 0; | |
1447 | } | |
1448 | END_STRING_AND_SAVE (base_string); | |
1449 | /* We've got a scale factor. */ | |
1450 | if (! sscanf (num_string, "%d", &num)) { | |
1451 | as_bad ("can't parse scale factor from '%s'", num_string); | |
1452 | return 0; | |
1453 | } | |
1454 | RESTORE_END_STRING (base_string); | |
1455 | switch (num) { /* must be 1 digit scale */ | |
1456 | case 1: i.log2_scale_factor = 0; break; | |
1457 | case 2: i.log2_scale_factor = 1; break; | |
1458 | case 4: i.log2_scale_factor = 2; break; | |
1459 | case 8: i.log2_scale_factor = 3; break; | |
1460 | default: | |
1461 | as_bad ("expecting scale factor of 1, 2, 4, 8; got %d", num); | |
1462 | return 0; | |
1463 | } | |
1464 | } else { | |
1465 | if (! i.index_reg && *base_string == ',') { | |
1466 | as_bad ("expecting index register or scale factor after ','; got '%c'", | |
1467 | *(base_string+1)); | |
1468 | return 0; | |
1469 | } | |
1470 | } | |
1471 | } | |
1472 | ||
1473 | /* If there's an expression begining the operand, parse it, | |
1474 | assuming displacement_string_start and displacement_string_end | |
1475 | are meaningful. */ | |
1476 | if (displacement_string_start) { | |
1477 | register expressionS * exp; | |
1478 | segT exp_seg; | |
1479 | char * save_input_line_pointer; | |
1480 | exp = &disp_expressions[i.disp_operands]; | |
1481 | i.disps [this_operand] = exp; | |
1482 | i.disp_operands++; | |
1483 | save_input_line_pointer = input_line_pointer; | |
1484 | input_line_pointer = displacement_string_start; | |
1485 | END_STRING_AND_SAVE (displacement_string_end); | |
1486 | exp_seg = expression (exp); | |
1487 | if(*input_line_pointer) | |
1488 | as_bad("Ignoring junk '%s' after expression",input_line_pointer); | |
1489 | RESTORE_END_STRING (displacement_string_end); | |
1490 | input_line_pointer = save_input_line_pointer; | |
1491 | switch (exp_seg) { | |
1492 | case SEG_NONE: | |
1493 | /* missing expr becomes absolute 0 */ | |
1494 | as_bad ("missing or invalid displacement '%s' taken as 0", | |
1495 | operand_string); | |
1496 | i.types[this_operand] |= (Disp|Abs); | |
1497 | exp->X_seg = SEG_ABSOLUTE; | |
1498 | exp->X_add_number = 0; | |
1499 | exp->X_add_symbol = (symbolS *) 0; | |
1500 | exp->X_subtract_symbol = (symbolS *) 0; | |
1501 | break; | |
1502 | case SEG_ABSOLUTE: | |
1503 | i.types[this_operand] |= SMALLEST_DISP_TYPE (exp->X_add_number); | |
1504 | break; | |
1505 | case SEG_TEXT: case SEG_DATA: case SEG_BSS: | |
1506 | case SEG_UNKNOWN: /* must be 32 bit displacement (i.e. address) */ | |
1507 | i.types[this_operand] |= Disp32; | |
1508 | break; | |
1509 | default: | |
1510 | goto seg_unimplemented; | |
1511 | } | |
1512 | } | |
1513 | ||
1514 | /* Make sure the memory operand we've been dealt is valid. */ | |
1515 | if (i.base_reg && i.index_reg && | |
1516 | ! (i.base_reg->reg_type & i.index_reg->reg_type & Reg)) { | |
1517 | as_bad ("register size mismatch in (base,index,scale) expression"); | |
1518 | return 0; | |
1519 | } | |
1520 | if ((i.base_reg && (i.base_reg->reg_type & Reg32) == 0) || | |
1521 | (i.index_reg && (i.index_reg->reg_type & Reg32) == 0)) { | |
1522 | as_bad ("base/index register must be 32 bit register"); | |
1523 | return 0; | |
1524 | } | |
1525 | if (i.index_reg && i.index_reg == esp) { | |
1526 | as_bad ("%s may not be used as an index register", esp->reg_name); | |
1527 | return 0; | |
1528 | } | |
1529 | } else { /* it's not a memory operand; argh! */ | |
1530 | as_bad ("invalid char %s begining %s operand '%s'", | |
1531 | output_invalid(*op_string), ordinal_names[this_operand], | |
1532 | op_string); | |
1533 | return 0; | |
1534 | } | |
1535 | return 1; /* normal return */ | |
1536 | } | |
1537 | \f | |
1538 | /* | |
1539 | * md_estimate_size_before_relax() | |
1540 | * | |
1541 | * Called just before relax(). | |
1542 | * Any symbol that is now undefined will not become defined. | |
1543 | * Return the correct fr_subtype in the frag. | |
1544 | * Return the initial "guess for fr_var" to caller. | |
1545 | * The guess for fr_var is ACTUALLY the growth beyond fr_fix. | |
1546 | * Whatever we do to grow fr_fix or fr_var contributes to our returned value. | |
1547 | * Although it may not be explicit in the frag, pretend fr_var starts with a | |
1548 | * 0 value. | |
1549 | */ | |
1550 | int | |
1551 | md_estimate_size_before_relax (fragP, segment_type) | |
1552 | register fragS * fragP; | |
1553 | register int segment_type; /* N_DATA or N_TEXT. */ | |
1554 | { | |
1555 | register uchar * opcode; | |
1556 | register int old_fr_fix; | |
1557 | ||
1558 | old_fr_fix = fragP -> fr_fix; | |
1559 | opcode = (uchar *) fragP -> fr_opcode; | |
1560 | /* We've already got fragP->fr_subtype right; all we have to do is check | |
1561 | for un-relaxable symbols. */ | |
1562 | if ((fragP -> fr_symbol -> sy_type & N_TYPE) != segment_type) { | |
1563 | /* symbol is undefined in this segment */ | |
1564 | switch (opcode[0]) { | |
1565 | case JUMP_PC_RELATIVE: /* make jmp (0xeb) a dword displacement jump */ | |
1566 | opcode[0] = 0xe9; /* dword disp jmp */ | |
1567 | fragP -> fr_fix += 4; | |
1568 | fix_new (fragP, old_fr_fix, 4, | |
1569 | fragP -> fr_symbol, | |
1570 | (symbolS *) 0, | |
1571 | fragP -> fr_offset, 1); | |
1572 | break; | |
1573 | ||
1574 | default: | |
1575 | /* This changes the byte-displacement jump 0x7N --> | |
1576 | the dword-displacement jump 0x0f8N */ | |
1577 | opcode[1] = opcode[0] + 0x10; | |
1578 | opcode[0] = TWO_BYTE_OPCODE_ESCAPE; /* two-byte escape */ | |
1579 | fragP -> fr_fix += 1 + 4; /* we've added an opcode byte */ | |
1580 | fix_new (fragP, old_fr_fix + 1, 4, | |
1581 | fragP -> fr_symbol, | |
1582 | (symbolS *) 0, | |
1583 | fragP -> fr_offset, 1); | |
1584 | break; | |
1585 | } | |
1586 | frag_wane (fragP); | |
1587 | } | |
1588 | return (fragP -> fr_var + fragP -> fr_fix - old_fr_fix); | |
1589 | } /* md_estimate_size_before_relax() */ | |
1590 | \f | |
1591 | /* | |
1592 | * md_convert_frag(); | |
1593 | * | |
1594 | * Called after relax() is finished. | |
1595 | * In: Address of frag. | |
1596 | * fr_type == rs_machine_dependent. | |
1597 | * fr_subtype is what the address relaxed to. | |
1598 | * | |
1599 | * Out: Any fixSs and constants are set up. | |
1600 | * Caller will turn frag into a ".space 0". | |
1601 | */ | |
1602 | void | |
1603 | md_convert_frag (fragP) | |
1604 | register fragS * fragP; | |
1605 | { | |
1606 | register uchar * opcode; | |
1607 | uchar * where_to_put_displacement; | |
1608 | uint target_address, opcode_address; | |
1609 | uint extension; | |
1610 | int displacement_from_opcode_start; | |
1611 | ||
1612 | opcode = (uchar *) fragP -> fr_opcode; | |
1613 | ||
1614 | /* Address we want to reach in file space. */ | |
1615 | target_address = fragP->fr_symbol->sy_value + fragP->fr_offset; | |
1616 | ||
1617 | /* Address opcode resides at in file space. */ | |
1618 | opcode_address = fragP->fr_address + fragP->fr_fix; | |
1619 | ||
1620 | /* Displacement from opcode start to fill into instruction. */ | |
1621 | displacement_from_opcode_start = target_address - opcode_address; | |
1622 | ||
1623 | switch (fragP->fr_subtype) { | |
1624 | case ENCODE_RELAX_STATE (COND_JUMP, BYTE): | |
1625 | case ENCODE_RELAX_STATE (UNCOND_JUMP, BYTE): | |
1626 | /* don't have to change opcode */ | |
1627 | extension = 1; /* 1 opcode + 1 displacement */ | |
1628 | where_to_put_displacement = &opcode[1]; | |
1629 | break; | |
1630 | ||
1631 | case ENCODE_RELAX_STATE (COND_JUMP, WORD): | |
1632 | opcode[1] = TWO_BYTE_OPCODE_ESCAPE; | |
1633 | opcode[2] = opcode[0] + 0x10; | |
1634 | opcode[0] = WORD_PREFIX_OPCODE; | |
1635 | extension = 4; /* 3 opcode + 2 displacement */ | |
1636 | where_to_put_displacement = &opcode[3]; | |
1637 | break; | |
1638 | ||
1639 | case ENCODE_RELAX_STATE (UNCOND_JUMP, WORD): | |
1640 | opcode[1] = 0xe9; | |
1641 | opcode[0] = WORD_PREFIX_OPCODE; | |
1642 | extension = 3; /* 2 opcode + 2 displacement */ | |
1643 | where_to_put_displacement = &opcode[2]; | |
1644 | break; | |
1645 | ||
1646 | case ENCODE_RELAX_STATE (COND_JUMP, DWORD): | |
1647 | opcode[1] = opcode[0] + 0x10; | |
1648 | opcode[0] = TWO_BYTE_OPCODE_ESCAPE; | |
1649 | extension = 5; /* 2 opcode + 4 displacement */ | |
1650 | where_to_put_displacement = &opcode[2]; | |
1651 | break; | |
1652 | ||
1653 | case ENCODE_RELAX_STATE (UNCOND_JUMP, DWORD): | |
1654 | opcode[0] = 0xe9; | |
1655 | extension = 4; /* 1 opcode + 4 displacement */ | |
1656 | where_to_put_displacement = &opcode[1]; | |
1657 | break; | |
1658 | ||
1659 | default: | |
1660 | BAD_CASE(fragP -> fr_subtype); | |
1661 | break; | |
1662 | } | |
1663 | /* now put displacement after opcode */ | |
1664 | md_number_to_chars (where_to_put_displacement, | |
1665 | displacement_from_opcode_start - extension, | |
1666 | SIZE_FROM_RELAX_STATE (fragP->fr_subtype)); | |
1667 | fragP -> fr_fix += extension; | |
1668 | } | |
1669 | ||
1670 | \f | |
1671 | int md_short_jump_size = 2; /* size of byte displacement jmp */ | |
1672 | int md_long_jump_size = 5; /* size of dword displacement jmp */ | |
1673 | ||
1674 | void md_create_short_jump(ptr, from_addr, to_addr) | |
1675 | char *ptr; | |
1676 | long from_addr, to_addr; | |
1677 | { | |
1678 | long offset; | |
1679 | ||
1680 | offset = to_addr - (from_addr + 2); | |
1681 | md_number_to_chars (ptr, (long) 0xeb, 1); /* opcode for byte-disp jump */ | |
1682 | md_number_to_chars (ptr + 1, offset, 1); | |
1683 | } | |
1684 | ||
1685 | void md_create_long_jump (ptr, from_addr, to_addr, frag, to_symbol) | |
1686 | char *ptr; | |
1687 | long from_addr, to_addr; | |
1688 | fragS *frag; | |
1689 | symbolS *to_symbol; | |
1690 | { | |
1691 | long offset; | |
1692 | ||
1693 | if (flagseen['m']) { | |
1694 | offset = to_addr - to_symbol->sy_value; | |
1695 | md_number_to_chars (ptr, 0xe9, 1); /* opcode for long jmp */ | |
1696 | md_number_to_chars (ptr + 1, offset, 4); | |
1697 | fix_new (frag, (ptr+1) - frag->fr_literal, 4, | |
1698 | to_symbol, (symbolS *) 0, (long int) 0, 0); | |
1699 | } else { | |
1700 | offset = to_addr - (from_addr + 5); | |
1701 | md_number_to_chars(ptr, (long) 0xe9, 1); | |
1702 | md_number_to_chars(ptr + 1, offset, 4); | |
1703 | } | |
1704 | } | |
1705 | \f | |
1706 | int | |
1707 | md_parse_option(argP,cntP,vecP) | |
1708 | char **argP; | |
1709 | int *cntP; | |
1710 | char ***vecP; | |
1711 | { | |
1712 | return 1; | |
1713 | } | |
1714 | \f | |
1715 | void /* Knows about order of bytes in address. */ | |
1716 | md_number_to_chars (con, value, nbytes) | |
1717 | char con []; /* Return 'nbytes' of chars here. */ | |
1718 | long int value; /* The value of the bits. */ | |
1719 | int nbytes; /* Number of bytes in the output. */ | |
1720 | { | |
1721 | register char * p = con; | |
1722 | ||
1723 | switch (nbytes) { | |
1724 | case 1: | |
1725 | p[0] = value & 0xff; | |
1726 | break; | |
1727 | case 2: | |
1728 | p[0] = value & 0xff; | |
1729 | p[1] = (value >> 8) & 0xff; | |
1730 | break; | |
1731 | case 4: | |
1732 | p[0] = value & 0xff; | |
1733 | p[1] = (value>>8) & 0xff; | |
1734 | p[2] = (value>>16) & 0xff; | |
1735 | p[3] = (value>>24) & 0xff; | |
1736 | break; | |
1737 | default: | |
1738 | BAD_CASE (nbytes); | |
1739 | } | |
1740 | } | |
1741 | ||
1742 | void /* Knows about order of bytes in address. */ | |
1743 | md_number_to_disp (con, value, nbytes) | |
1744 | char con []; /* Return 'nbytes' of chars here. */ | |
1745 | long int value; /* The value of the bits. */ | |
1746 | int nbytes; /* Number of bytes in the output. */ | |
1747 | { | |
1748 | char * answer = alloca (nbytes); | |
1749 | register char * p = answer; | |
1750 | ||
1751 | switch (nbytes) { | |
1752 | case 1: | |
1753 | *p = value; | |
1754 | break; | |
1755 | case 2: | |
1756 | *p++ = value; | |
1757 | *p = (value>>8); | |
1758 | break; | |
1759 | case 4: | |
1760 | *p++ = value; | |
1761 | *p++ = (value>>8); | |
1762 | *p++ = (value>>16); | |
1763 | *p = (value>>24); | |
1764 | break; | |
1765 | default: | |
1766 | BAD_CASE (nbytes); | |
1767 | } | |
1768 | bcopy (answer, con, nbytes); | |
1769 | } | |
1770 | ||
1771 | void /* Knows about order of bytes in address. */ | |
1772 | md_number_to_imm (con, value, nbytes) | |
1773 | char con []; /* Return 'nbytes' of chars here. */ | |
1774 | long int value; /* The value of the bits. */ | |
1775 | int nbytes; /* Number of bytes in the output. */ | |
1776 | { | |
1777 | char * answer = alloca (nbytes); | |
1778 | register char * p = answer; | |
1779 | ||
1780 | switch (nbytes) { | |
1781 | case 1: | |
1782 | *p = value; | |
1783 | break; | |
1784 | case 2: | |
1785 | *p++ = value; | |
1786 | *p = (value>>8); | |
1787 | break; | |
1788 | case 4: | |
1789 | *p++ = value; | |
1790 | *p++ = (value>>8); | |
1791 | *p++ = (value>>16); | |
1792 | *p = (value>>24); | |
1793 | break; | |
1794 | default: | |
1795 | BAD_CASE (nbytes); | |
1796 | } | |
1797 | bcopy (answer, con, nbytes); | |
1798 | } | |
1799 | ||
1800 | void /* Knows about order of bytes in address. */ | |
1801 | md_number_to_field (con, value, nbytes) | |
1802 | char con []; /* Return 'nbytes' of chars here. */ | |
1803 | long int value; /* The value of the bits. */ | |
1804 | int nbytes; /* Number of bytes in the output. */ | |
1805 | { | |
1806 | char * answer = alloca (nbytes); | |
1807 | register char * p = answer; | |
1808 | ||
1809 | switch (nbytes) { | |
1810 | case 1: | |
1811 | *p = value; | |
1812 | break; | |
1813 | case 2: | |
1814 | *p++ = value; | |
1815 | *p = (value>>8); | |
1816 | break; | |
1817 | case 4: | |
1818 | *p++ = value; | |
1819 | *p++ = (value>>8); | |
1820 | *p++ = (value>>16); | |
1821 | *p = (value>>24); | |
1822 | break; | |
1823 | default: | |
1824 | BAD_CASE (nbytes); | |
1825 | } | |
1826 | bcopy (answer, con, nbytes); | |
1827 | } | |
1828 | ||
1829 | long int /* Knows about the byte order in a word. */ | |
1830 | md_chars_to_number (con, nbytes) | |
1831 | unsigned char con[]; /* Low order byte 1st. */ | |
1832 | int nbytes; /* Number of bytes in the input. */ | |
1833 | { | |
1834 | long int retval; | |
1835 | for (retval=0, con+=nbytes-1; nbytes--; con--) | |
1836 | { | |
1837 | retval <<= BITS_PER_CHAR; | |
1838 | retval |= *con; | |
1839 | } | |
1840 | return retval; | |
1841 | } | |
1842 | ||
1843 | void md_ri_to_chars(ri_p, ri) | |
1844 | struct relocation_info *ri_p, ri; | |
1845 | { | |
1846 | unsigned char the_bytes[8]; | |
1847 | ||
1848 | /* this is easy */ | |
1849 | md_number_to_chars(the_bytes, ri.r_address, sizeof(ri.r_address)); | |
1850 | /* now the fun stuff */ | |
1851 | the_bytes[6] = (ri.r_symbolnum >> 16) & 0x0ff; | |
1852 | the_bytes[5] = (ri.r_symbolnum >> 8) & 0x0ff; | |
1853 | the_bytes[4] = ri.r_symbolnum & 0x0ff; | |
1854 | the_bytes[7] = (((ri.r_extern << 3) & 0x08) | ((ri.r_length << 1) & 0x06) | | |
1855 | ((ri.r_pcrel << 0) & 0x01)) & 0x0F; | |
1856 | /* now put it back where you found it */ | |
1857 | bcopy (the_bytes, (char *)ri_p, sizeof(struct relocation_info)); | |
1858 | } | |
1859 | ||
1860 | \f | |
1861 | #define MAX_LITTLENUMS 6 | |
1862 | ||
1863 | /* Turn the string pointed to by litP into a floating point constant of type | |
1864 | type, and emit the appropriate bytes. The number of LITTLENUMS emitted | |
1865 | is stored in *sizeP . An error message is returned, or NULL on OK. | |
1866 | */ | |
1867 | char * | |
1868 | md_atof(type,litP,sizeP) | |
1869 | char type; | |
1870 | char *litP; | |
1871 | int *sizeP; | |
1872 | { | |
1873 | int prec; | |
1874 | LITTLENUM_TYPE words[MAX_LITTLENUMS]; | |
1875 | LITTLENUM_TYPE *wordP; | |
1876 | char *t; | |
1877 | char *atof_ieee(); | |
1878 | ||
1879 | switch(type) { | |
1880 | case 'f': | |
1881 | case 'F': | |
1882 | prec = 2; | |
1883 | break; | |
1884 | ||
1885 | case 'd': | |
1886 | case 'D': | |
1887 | prec = 4; | |
1888 | break; | |
1889 | ||
1890 | case 'x': | |
1891 | case 'X': | |
1892 | prec = 5; | |
1893 | break; | |
1894 | ||
1895 | default: | |
1896 | *sizeP=0; | |
1897 | return "Bad call to md_atof ()"; | |
1898 | } | |
1899 | t = atof_ieee (input_line_pointer,type,words); | |
1900 | if(t) | |
1901 | input_line_pointer=t; | |
1902 | ||
1903 | *sizeP = prec * sizeof(LITTLENUM_TYPE); | |
1904 | /* this loops outputs the LITTLENUMs in REVERSE order; in accord with | |
1905 | the bigendian 386 */ | |
1906 | for(wordP = words + prec - 1;prec--;) { | |
1907 | md_number_to_chars (litP, (long) (*wordP--), sizeof(LITTLENUM_TYPE)); | |
1908 | litP += sizeof(LITTLENUM_TYPE); | |
1909 | } | |
1910 | return ""; /* Someone should teach Dean about null pointers */ | |
1911 | } | |
1912 | \f | |
1913 | char output_invalid_buf[8]; | |
1914 | ||
1915 | char * output_invalid (c) | |
1916 | char c; | |
1917 | { | |
1918 | if (isprint(c)) sprintf (output_invalid_buf, "'%c'", c); | |
1919 | else sprintf (output_invalid_buf, "(0x%x)", c); | |
1920 | return output_invalid_buf; | |
1921 | } | |
1922 | ||
1923 | reg_entry *parse_register (reg_string) | |
1924 | char *reg_string; /* reg_string starts *before* REGISTER_PREFIX */ | |
1925 | { | |
1926 | register char *s = reg_string; | |
1927 | register char *p; | |
1928 | char reg_name_given[MAX_REG_NAME_SIZE]; | |
1929 | ||
1930 | s++; /* skip REGISTER_PREFIX */ | |
1931 | for (p = reg_name_given; is_register_char (*s); p++, s++) { | |
1932 | *p = register_chars [*s]; | |
1933 | if (p >= reg_name_given + MAX_REG_NAME_SIZE) | |
1934 | return (reg_entry *) 0; | |
1935 | } | |
1936 | *p = '\0'; | |
1937 | return (reg_entry *) hash_find (reg_hash, reg_name_given); | |
1938 | } | |
1939 |