source: branches/libc-0.6/src/binutils/opcodes/pdp11-dis.c

Last change on this file was 607, checked in by bird, 22 years ago

Initial revision
  • Property cvs2svn:cvs-rev set to 1.1
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 9.4 KB
Line 
1/* Print DEC PDP-11 instructions.
2 Copyright 2001, 2002 Free Software Foundation, Inc.
3
4This file is free software; you can redistribute it and/or modify
5it under the terms of the GNU General Public License as published by
6the Free Software Foundation; either version 2 of the License, or
7(at your option) any later version.
8
9This program is distributed in the hope that it will be useful,
10but WITHOUT ANY WARRANTY; without even the implied warranty of
11MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12GNU General Public License for more details.
13
14You should have received a copy of the GNU General Public License
15along with this program; if not, write to the Free Software
16Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
17
18#include "sysdep.h"
19#include "dis-asm.h"
20#include "opcode/pdp11.h"
21
22#define AFTER_INSTRUCTION "\t"
23#define OPERAND_SEPARATOR ", "
24
25#define JUMP 0x1000 /* flag that this operand is used in a jump */
26
27#define FPRINTF (*info->fprintf_func)
28#define F info->stream
29
30/* sign-extend a 16-bit number in an int */
31#define SIGN_BITS (8 * sizeof (int) - 16)
32#define sign_extend(x) (((x) << SIGN_BITS) >> SIGN_BITS)
33
34static int read_word PARAMS ((bfd_vma memaddr, int *word,
35 disassemble_info *info));
36static void print_signed_octal PARAMS ((int n, disassemble_info *info));
37static void print_reg PARAMS ((int reg, disassemble_info *info));
38static void print_freg PARAMS ((int freg, disassemble_info *info));
39static int print_operand PARAMS ((bfd_vma *memaddr, int code,
40 disassemble_info *info));
41static int print_foperand PARAMS ((bfd_vma *memaddr, int code,
42 disassemble_info *info));
43int print_insn_pdp11 PARAMS ((bfd_vma memaddr, disassemble_info *info));
44
45static int
46read_word (memaddr, word, info)
47 bfd_vma memaddr;
48 int *word;
49 disassemble_info *info;
50{
51 int status;
52 bfd_byte x[2];
53
54 status = (*info->read_memory_func) (memaddr, x, 2, info);
55 if (status != 0)
56 return -1;
57
58 *word = x[1] << 8 | x[0];
59 return 0;
60}
61
62static void
63print_signed_octal (n, info)
64 int n;
65 disassemble_info *info;
66{
67 if (n < 0)
68 FPRINTF (F, "-%o", -n);
69 else
70 FPRINTF (F, "%o", n);
71}
72
73static void
74print_reg (reg, info)
75 int reg;
76 disassemble_info *info;
77{
78 /* mask off the addressing mode, if any */
79 reg &= 7;
80
81 switch (reg)
82 {
83 case 0: case 1: case 2: case 3: case 4: case 5:
84 FPRINTF (F, "r%d", reg); break;
85 case 6: FPRINTF (F, "sp"); break;
86 case 7: FPRINTF (F, "pc"); break;
87 default: ; /* error */
88 }
89}
90
91static void
92print_freg (freg, info)
93 int freg;
94 disassemble_info *info;
95{
96 FPRINTF (F, "fr%d", freg);
97}
98
99static int
100print_operand (memaddr, code, info)
101 bfd_vma *memaddr;
102 int code;
103 disassemble_info *info;
104{
105 int mode = (code >> 3) & 7;
106 int reg = code & 7;
107 int disp;
108
109 switch (mode)
110 {
111 case 0:
112 print_reg (reg, info);
113 break;
114 case 1:
115 FPRINTF (F, "(");
116 print_reg (reg, info);
117 FPRINTF (F, ")");
118 break;
119 case 2:
120 if (reg == 7)
121 {
122 int data;
123 if (read_word (*memaddr, &data, info) < 0)
124 return -1;
125 FPRINTF (F, "$");
126 print_signed_octal (sign_extend (data), info);
127 *memaddr += 2;
128 }
129 else
130 {
131 FPRINTF (F, "(");
132 print_reg (reg, info);
133 FPRINTF (F, ")+");
134 }
135 break;
136 case 3:
137 if (reg == 7)
138 {
139 int address;
140 if (read_word (*memaddr, &address, info) < 0)
141 return -1;
142 FPRINTF (F, "*$%o", address);
143 *memaddr += 2;
144 }
145 else
146 {
147 FPRINTF (F, "*(");
148 print_reg (reg, info);
149 FPRINTF (F, ")+");
150 }
151 break;
152 case 4:
153 FPRINTF (F, "-(");
154 print_reg (reg, info);
155 FPRINTF (F, ")");
156 break;
157 case 5:
158 FPRINTF (F, "*-(");
159 print_reg (reg, info);
160 FPRINTF (F, ")");
161 break;
162 case 6:
163 case 7:
164 if (read_word (*memaddr, &disp, info) < 0)
165 return -1;
166 *memaddr += 2;
167 if (reg == 7)
168 {
169 bfd_vma address = *memaddr + sign_extend (disp);
170 if (mode == 7)
171 FPRINTF (F, "*");
172 if (!(code & JUMP))
173 FPRINTF (F, "$");
174 (*info->print_address_func) (address, info);
175 }
176 else
177 {
178 if (mode == 7)
179 FPRINTF (F, "*");
180 print_signed_octal (sign_extend (disp), info);
181 FPRINTF (F, "(");
182 print_reg (reg, info);
183 FPRINTF (F, ")");
184 }
185 break;
186 }
187
188 return 0;
189}
190
191static int
192print_foperand (memaddr, code, info)
193 bfd_vma *memaddr;
194 int code;
195 disassemble_info *info;
196{
197 int mode = (code >> 3) & 7;
198 int reg = code & 7;
199
200 if (mode == 0)
201 print_freg (reg, info);
202 else
203 return print_operand (memaddr, code, info);
204
205 return 0;
206}
207
208/* Print the PDP-11 instruction at address MEMADDR in debugged memory,
209 on INFO->STREAM. Returns length of the instruction, in bytes. */
210
211int
212print_insn_pdp11 (memaddr, info)
213 bfd_vma memaddr;
214 disassemble_info *info;
215{
216 bfd_vma start_memaddr = memaddr;
217 int opcode;
218 int src, dst;
219 int i;
220
221 info->bytes_per_line = 6;
222 info->bytes_per_chunk = 2;
223 info->display_endian = BFD_ENDIAN_LITTLE;
224
225 if (read_word (memaddr, &opcode, info) != 0)
226 return -1;
227 memaddr += 2;
228
229 src = (opcode >> 6) & 0x3f;
230 dst = opcode & 0x3f;
231
232 for (i = 0; i < pdp11_num_opcodes; i++)
233 {
234#define OP pdp11_opcodes[i]
235 if ((opcode & OP.mask) == OP.opcode)
236 switch (OP.type)
237 {
238 case PDP11_OPCODE_NO_OPS:
239 FPRINTF (F, OP.name);
240 goto done;
241 case PDP11_OPCODE_REG:
242 FPRINTF (F, OP.name);
243 FPRINTF (F, AFTER_INSTRUCTION);
244 print_reg (dst, info);
245 goto done;
246 case PDP11_OPCODE_OP:
247 FPRINTF (F, OP.name);
248 FPRINTF (F, AFTER_INSTRUCTION);
249 if (strcmp (OP.name, "jmp") == 0)
250 dst |= JUMP;
251 if (print_operand (&memaddr, dst, info) < 0)
252 return -1;
253 goto done;
254 case PDP11_OPCODE_FOP:
255 FPRINTF (F, OP.name);
256 FPRINTF (F, AFTER_INSTRUCTION);
257 if (strcmp (OP.name, "jmp") == 0)
258 dst |= JUMP;
259 if (print_foperand (&memaddr, dst, info) < 0)
260 return -1;
261 goto done;
262 case PDP11_OPCODE_REG_OP:
263 FPRINTF (F, OP.name);
264 FPRINTF (F, AFTER_INSTRUCTION);
265 print_reg (src, info);
266 FPRINTF (F, OPERAND_SEPARATOR);
267 if (strcmp (OP.name, "jsr") == 0)
268 dst |= JUMP;
269 if (print_operand (&memaddr, dst, info) < 0)
270 return -1;
271 goto done;
272 case PDP11_OPCODE_REG_OP_REV:
273 FPRINTF (F, OP.name);
274 FPRINTF (F, AFTER_INSTRUCTION);
275 if (print_operand (&memaddr, dst, info) < 0)
276 return -1;
277 FPRINTF (F, OPERAND_SEPARATOR);
278 print_reg (src, info);
279 goto done;
280 case PDP11_OPCODE_AC_FOP:
281 {
282 int ac = (opcode & 0xe0) >> 6;
283 FPRINTF (F, OP.name);
284 FPRINTF (F, AFTER_INSTRUCTION);
285 print_freg (ac, info);
286 FPRINTF (F, OPERAND_SEPARATOR);
287 if (print_foperand (&memaddr, dst, info) < 0)
288 return -1;
289 goto done;
290 }
291 case PDP11_OPCODE_FOP_AC:
292 {
293 int ac = (opcode & 0xe0) >> 6;
294 FPRINTF (F, OP.name);
295 FPRINTF (F, AFTER_INSTRUCTION);
296 if (print_foperand (&memaddr, dst, info) < 0)
297 return -1;
298 FPRINTF (F, OPERAND_SEPARATOR);
299 print_freg (ac, info);
300 goto done;
301 }
302 case PDP11_OPCODE_AC_OP:
303 {
304 int ac = (opcode & 0xe0) >> 6;
305 FPRINTF (F, OP.name);
306 FPRINTF (F, AFTER_INSTRUCTION);
307 print_freg (ac, info);
308 FPRINTF (F, OPERAND_SEPARATOR);
309 if (print_operand (&memaddr, dst, info) < 0)
310 return -1;
311 goto done;
312 }
313 case PDP11_OPCODE_OP_AC:
314 {
315 int ac = (opcode & 0xe0) >> 6;
316 FPRINTF (F, OP.name);
317 FPRINTF (F, AFTER_INSTRUCTION);
318 if (print_operand (&memaddr, dst, info) < 0)
319 return -1;
320 FPRINTF (F, OPERAND_SEPARATOR);
321 print_freg (ac, info);
322 goto done;
323 }
324 case PDP11_OPCODE_OP_OP:
325 FPRINTF (F, OP.name);
326 FPRINTF (F, AFTER_INSTRUCTION);
327 if (print_operand (&memaddr, src, info) < 0)
328 return -1;
329 FPRINTF (F, OPERAND_SEPARATOR);
330 if (print_operand (&memaddr, dst, info) < 0)
331 return -1;
332 goto done;
333 case PDP11_OPCODE_DISPL:
334 {
335 int displ = (opcode & 0xff) << 8;
336 bfd_vma address = memaddr + (sign_extend (displ) >> 7);
337 FPRINTF (F, OP.name);
338 FPRINTF (F, AFTER_INSTRUCTION);
339 (*info->print_address_func) (address, info);
340 goto done;
341 }
342 case PDP11_OPCODE_REG_DISPL:
343 {
344 int displ = (opcode & 0x3f) << 10;
345 bfd_vma address = memaddr + (sign_extend (displ) >> 9);
346 FPRINTF (F, OP.name);
347 FPRINTF (F, AFTER_INSTRUCTION);
348 print_reg (src, info);
349 FPRINTF (F, OPERAND_SEPARATOR);
350 (*info->print_address_func) (address, info);
351 goto done;
352 }
353 case PDP11_OPCODE_IMM8:
354 {
355 int code = opcode & 0xff;
356 FPRINTF (F, OP.name);
357 FPRINTF (F, AFTER_INSTRUCTION);
358 FPRINTF (F, "%o", code);
359 goto done;
360 }
361 case PDP11_OPCODE_IMM6:
362 {
363 int code = opcode & 0x3f;
364 FPRINTF (F, OP.name);
365 FPRINTF (F, AFTER_INSTRUCTION);
366 FPRINTF (F, "%o", code);
367 goto done;
368 }
369 case PDP11_OPCODE_IMM3:
370 {
371 int code = opcode & 7;
372 FPRINTF (F, OP.name);
373 FPRINTF (F, AFTER_INSTRUCTION);
374 FPRINTF (F, "%o", code);
375 goto done;
376 }
377 case PDP11_OPCODE_ILLEGAL:
378 {
379 FPRINTF (F, ".word");
380 FPRINTF (F, AFTER_INSTRUCTION);
381 FPRINTF (F, "%o", opcode);
382 goto done;
383 }
384 default:
385 /* TODO: is this a proper way of signalling an error? */
386 FPRINTF (F, "<internal error: unrecognized instruction type>");
387 return -1;
388 }
389#undef OP
390 }
391 done:
392
393 return memaddr - start_memaddr;
394}
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