[binutils.git] / opcodes / pdp11-dis.c

/* Print DEC PDP-11 instructions.
   Copyright 2001 Free Software Foundation, Inc.

This file is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "dis-asm.h"
#include "opcode/pdp11.h"

#define AFTER_INSTRUCTION	"\t"
#define OPERAND_SEPARATOR	", "

#define JUMP	0x1000	/* flag that this operand is used in a jump */

#define FPRINTF	(*info->fprintf_func)
#define F	info->stream

/* sign-extend a 16-bit number in an int */
#define SIGN_BITS	(8 * sizeof (int) - 16)
#define sign_extend(x) (((x) << SIGN_BITS) >> SIGN_BITS)

static int read_word PARAMS ((bfd_vma memaddr, int *word,
			      disassemble_info *info));
static void print_signed_octal PARAMS ((int n, disassemble_info *info));
static void print_reg PARAMS ((int reg, disassemble_info *info));
static void print_freg PARAMS ((int freg, disassemble_info *info));
static int print_operand PARAMS ((bfd_vma *memaddr, int code,
				  disassemble_info *info));
int print_insn_pdp11 PARAMS ((bfd_vma memaddr, disassemble_info *info));

static int
read_word (memaddr, word, info)
     bfd_vma memaddr;
     int *word;
     disassemble_info *info;
{
  int status;
  bfd_byte x[2];

  status = (*info->read_memory_func) (memaddr, x, 2, info);
  if (status != 0)
    return -1;

  *word = x[1] << 8 | x[0];
  return 0;
}

static void
print_signed_octal (n, info)
     int n;
     disassemble_info *info;
{
  if (n < 0)
    FPRINTF (F, "-%o", -n);
  else
    FPRINTF (F, "%o", n);
}

static void
print_reg (reg, info)
     int reg;
     disassemble_info *info;
{
  /* mask off the addressing mode, if any */
  reg &= 7;

  switch (reg)
    {
    case 0: case 1: case 2: case 3: case 4: case 5:
		FPRINTF (F, "r%d", reg); break;
    case 6:	FPRINTF (F, "sp"); break;
    case 7:	FPRINTF (F, "pc"); break;
    default:	/* error */
    }
}

static void
print_freg (freg, info)
     int freg;
     disassemble_info *info;
{
  FPRINTF (F, "fr%d", freg);
}

static int
print_operand (memaddr, code, info)
     bfd_vma *memaddr;
     int code;
     disassemble_info *info;
{
  int mode = (code >> 3) & 7;
  int reg = code & 7;
  int disp;

  switch (mode)
    {
    case 0:
      print_reg (reg, info);
      break;
    case 1:
      FPRINTF (F, "(");
      print_reg (reg, info);
      FPRINTF (F, ")");
      break;
    case 2:
      if (reg == 7)
	{
	  int data;
	  if (read_word (*memaddr, &data, info) < 0)
	    return -1;
	  FPRINTF (F, "$");
	  print_signed_octal (sign_extend (data), info);
	  *memaddr += 2;
	}
      else
	{
	  FPRINTF (F, "(");
	  print_reg (reg, info);
	  FPRINTF (F, ")+");
	}
	break;
    case 3:
      if (reg == 7)
	{
	  int address;
	  if (read_word (*memaddr, &address, info) < 0)
	    return -1;
	  FPRINTF (F, "*$%o", address);
	  *memaddr += 2;
	}
      else
	{
	  FPRINTF (F, "*(");
	  print_reg (reg, info);
	  FPRINTF (F, ")+");
	}
	break;
    case 4:
      FPRINTF (F, "-(");
      print_reg (reg, info);
      FPRINTF (F, ")");
      break;
    case 5:
      FPRINTF (F, "*-(");
      print_reg (reg, info);
      FPRINTF (F, ")");
      break;
    case 6:
    case 7:
      if (read_word (*memaddr, &disp, info) < 0)
	return -1;
      *memaddr += 2;
      if (reg == 7)
	{
	  bfd_vma address = *memaddr + sign_extend (disp);
	  if (!(code & JUMP))
	    FPRINTF (F, "*$");
	  (*info->print_address_func) (address, info);
	}
      else
	{
	  if (mode == 7)
	    FPRINTF (F, "*");
	  print_signed_octal (sign_extend (disp), info);
	  FPRINTF (F, "(");
	  print_reg (reg, info);
	  FPRINTF (F, ")");
	}
      break;
    }

  return 0;
}

/* Print the PDP-11 instruction at address MEMADDR in debugged memory,
   on INFO->STREAM.  Returns length of the instruction, in bytes.  */

int
print_insn_pdp11 (memaddr, info)
     bfd_vma memaddr;
     disassemble_info *info;
{
  bfd_vma start_memaddr = memaddr;
  int opcode;
  int src, dst;
  int i;

  info->bytes_per_line = 6;
  info->bytes_per_chunk = 2;
  info->display_endian = BFD_ENDIAN_LITTLE;

  if (read_word (memaddr, &opcode, info) != 0)
    return -1;
  memaddr += 2;

  src = (opcode >> 6) & 0x3f;
  dst = opcode & 0x3f;

  for (i = 0; i < pdp11_num_opcodes; i++)
    {
#define OP pdp11_opcodes[i]
      if ((opcode & OP.mask) == OP.opcode)
	switch (OP.type)
	  {
	  case PDP11_OPCODE_NO_OPS:
	    FPRINTF (F, OP.name);
	    break;
	  case PDP11_OPCODE_REG:
	    FPRINTF (F, OP.name);
	    FPRINTF (F, AFTER_INSTRUCTION);
	    print_reg (dst, info);
	    break;
	  case PDP11_OPCODE_OP:
	    FPRINTF (F, OP.name);
	    FPRINTF (F, AFTER_INSTRUCTION);
	    if (strcmp (OP.name, "jmp") == 0)
	      dst |= JUMP;
	    if (print_operand (&memaddr, dst, info) < 0)
	      return -1;
	    break;
	  case PDP11_OPCODE_REG_OP:
	    FPRINTF (F, OP.name);
	    FPRINTF (F, AFTER_INSTRUCTION);
	    print_reg (src, info);
	    FPRINTF (F, OPERAND_SEPARATOR);
	    if (strcmp (OP.name, "jsr") == 0)
	      dst |= JUMP;
	    if (print_operand (&memaddr, dst, info) < 0)
	      return -1;
	    break;
	  case PDP11_OPCODE_REG_OP_REV:
	    FPRINTF (F, OP.name);
	    FPRINTF (F, AFTER_INSTRUCTION);
	    if (print_operand (&memaddr, dst, info) < 0)
	      return -1;
	    FPRINTF (F, OPERAND_SEPARATOR);
	    print_reg (src, info);
	    break;
	  case PDP11_OPCODE_AC_OP:
	    {
	      int ac = (opcode & 0xe0) >> 6;
	      FPRINTF (F, OP.name);
	      FPRINTF (F, AFTER_INSTRUCTION);
	      print_freg (ac, info);
	      FPRINTF (F, OPERAND_SEPARATOR);
	      if (print_operand (&memaddr, dst, info) < 0)
		return -1;
	      break;
	    }
	  case PDP11_OPCODE_OP_OP:
	    FPRINTF (F, OP.name);
	    FPRINTF (F, AFTER_INSTRUCTION);
	    if (print_operand (&memaddr, src, info) < 0)
	      return -1;
	    FPRINTF (F, OPERAND_SEPARATOR);
	    if (print_operand (&memaddr, dst, info) < 0)
	      return -1;
	    break;
	  case PDP11_OPCODE_DISPL:
	    {
	      int displ = (opcode & 0xff) << 8;
	      bfd_vma address = memaddr + (sign_extend (displ) >> 7);
	      FPRINTF (F, OP.name);
	      FPRINTF (F, AFTER_INSTRUCTION);
	      (*info->print_address_func) (address, info);
	      break;
	    }
	  case PDP11_OPCODE_REG_DISPL:
	    {
	      int displ = (opcode & 0x3f) << 10;
	      bfd_vma address = memaddr + (sign_extend (displ) >> 9);
	      FPRINTF (F, OP.name);
	      FPRINTF (F, AFTER_INSTRUCTION);
	      print_reg (src, info);
	      FPRINTF (F, OPERAND_SEPARATOR);
	      (*info->print_address_func) (address, info);
	      break;
	    }
	  case PDP11_OPCODE_IMM8:
	    {
	      int code = opcode & 0xff;
	      FPRINTF (F, OP.name);
	      FPRINTF (F, AFTER_INSTRUCTION);
	      FPRINTF (F, "%o", code);
	      break;
	    }
	  case PDP11_OPCODE_IMM6:
	    {
	      int code = opcode & 0x3f;
	      FPRINTF (F, OP.name);
	      FPRINTF (F, AFTER_INSTRUCTION);
	      FPRINTF (F, "%o", code);
	      break;
	    }
	  case PDP11_OPCODE_IMM3:
	    {
	      int code = opcode & 7;
	      FPRINTF (F, OP.name);
	      FPRINTF (F, AFTER_INSTRUCTION);
	      FPRINTF (F, "%o", code);
	      break;
	    }
	  default:
	    /* TODO: is this a proper way of signalling an error? */
	    FPRINTF (F, "<internal error: unrecognized instruction type>");
	    return -1;
	  }
#undef OP
    }

  return memaddr - start_memaddr;
}
Commit	Line	Data
e135f41b NC	1	/* Print DEC PDP-11 instructions.
	2	Copyright 2001 Free Software Foundation, Inc.
	3
	4	This file is free software; you can redistribute it and/or modify
	5	it under the terms of the GNU General Public License as published by
	6	the Free Software Foundation; either version 2 of the License, or
	7	(at your option) any later version.
	8
	9	This program is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	GNU General Public License for more details.
	13
	14	You should have received a copy of the GNU General Public License
	15	along with this program; if not, write to the Free Software
	16	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
	17
	18	#include "dis-asm.h"
	19	#include "opcode/pdp11.h"
	20
	21	#define AFTER_INSTRUCTION "\t"
	22	#define OPERAND_SEPARATOR ", "
	23
	24	#define JUMP 0x1000 /* flag that this operand is used in a jump */
	25
	26	#define FPRINTF (*info->fprintf_func)
	27	#define F info->stream
	28
	29	/* sign-extend a 16-bit number in an int */
	30	#define SIGN_BITS (8 * sizeof (int) - 16)
	31	#define sign_extend(x) (((x) << SIGN_BITS) >> SIGN_BITS)
	32
	33	static int read_word PARAMS ((bfd_vma memaddr, int *word,
	34	disassemble_info *info));
	35	static void print_signed_octal PARAMS ((int n, disassemble_info *info));
	36	static void print_reg PARAMS ((int reg, disassemble_info *info));
	37	static void print_freg PARAMS ((int freg, disassemble_info *info));
	38	static int print_operand PARAMS ((bfd_vma *memaddr, int code,
	39	disassemble_info *info));
	40	int print_insn_pdp11 PARAMS ((bfd_vma memaddr, disassemble_info *info));
	41
	42	static int
	43	read_word (memaddr, word, info)
	44	bfd_vma memaddr;
	45	int *word;
	46	disassemble_info *info;
	47	{
	48	int status;
	49	bfd_byte x[2];
	50
	51	status = (*info->read_memory_func) (memaddr, x, 2, info);
	52	if (status != 0)
	53	return -1;
	54
	55	*word = x[1] << 8 \| x[0];
	56	return 0;
	57	}
	58
	59	static void
	60	print_signed_octal (n, info)
	61	int n;
	62	disassemble_info *info;
	63	{
	64	if (n < 0)
65	FPRINTF (F, "-%o", -n);
66	else
67	FPRINTF (F, "%o", n);
68	}
69
70	static void
71	print_reg (reg, info)
72	int reg;
73	disassemble_info *info;
74	{
75	/* mask off the addressing mode, if any */
76	reg &= 7;
77
78	switch (reg)
79	{
80	case 0: case 1: case 2: case 3: case 4: case 5:
81	FPRINTF (F, "r%d", reg); break;
82	case 6: FPRINTF (F, "sp"); break;
83	case 7: FPRINTF (F, "pc"); break;
84	default: /* error */
85	}
86	}
87
88	static void
89	print_freg (freg, info)
90	int freg;
91	disassemble_info *info;
92	{
93	FPRINTF (F, "fr%d", freg);
94	}
95
96	static int
97	print_operand (memaddr, code, info)
98	bfd_vma *memaddr;
99	int code;
100	disassemble_info *info;
101	{
102	int mode = (code >> 3) & 7;
103	int reg = code & 7;
104	int disp;
105
106	switch (mode)
107	{
108	case 0:
109	print_reg (reg, info);
110	break;
111	case 1:
112	FPRINTF (F, "(");
113	print_reg (reg, info);
114	FPRINTF (F, ")");
115	break;
116	case 2:
117	if (reg == 7)
118	{
119	int data;
120	if (read_word (*memaddr, &data, info) < 0)
121	return -1;
122	FPRINTF (F, "$");
123	print_signed_octal (sign_extend (data), info);
124	*memaddr += 2;
125	}
126	else
127	{
128	FPRINTF (F, "(");
129	print_reg (reg, info);
130	FPRINTF (F, ")+");
131	}
132	break;
133	case 3:
134	if (reg == 7)
135	{
136	int address;
137	if (read_word (*memaddr, &address, info) < 0)
138	return -1;
139	FPRINTF (F, "*$%o", address);
140	*memaddr += 2;
141	}
142	else
143	{
144	FPRINTF (F, "*(");
145	print_reg (reg, info);
146	FPRINTF (F, ")+");
147	}
148	break;
149	case 4:
150	FPRINTF (F, "-(");
151	print_reg (reg, info);
152	FPRINTF (F, ")");
153	break;
154	case 5:
155	FPRINTF (F, "*-(");
156	print_reg (reg, info);
157	FPRINTF (F, ")");
158	break;
159	case 6:
160	case 7:
161	if (read_word (*memaddr, &disp, info) < 0)
162	return -1;
163	*memaddr += 2;
164	if (reg == 7)
165	{
166	bfd_vma address = *memaddr + sign_extend (disp);
167	if (!(code & JUMP))
168	FPRINTF (F, "*$");
169	(*info->print_address_func) (address, info);
170	}
171	else
172	{
173	if (mode == 7)
174	FPRINTF (F, "*");
175	print_signed_octal (sign_extend (disp), info);
176	FPRINTF (F, "(");
177	print_reg (reg, info);
178	FPRINTF (F, ")");
179	}
180	break;
181	}
182
183	return 0;
184	}
185
186	/* Print the PDP-11 instruction at address MEMADDR in debugged memory,
187	on INFO->STREAM. Returns length of the instruction, in bytes. */
188
189	int
190	print_insn_pdp11 (memaddr, info)
191	bfd_vma memaddr;
192	disassemble_info *info;
193	{
194	bfd_vma start_memaddr = memaddr;
195	int opcode;
196	int src, dst;
197	int i;
198
199	info->bytes_per_line = 6;
200	info->bytes_per_chunk = 2;
201	info->display_endian = BFD_ENDIAN_LITTLE;
202
203	if (read_word (memaddr, &opcode, info) != 0)
204	return -1;
205	memaddr += 2;
206
207	src = (opcode >> 6) & 0x3f;
208	dst = opcode & 0x3f;
209
210	for (i = 0; i < pdp11_num_opcodes; i++)
211	{
212	#define OP pdp11_opcodes[i]
213	if ((opcode & OP.mask) == OP.opcode)
214	switch (OP.type)
215	{
216	case PDP11_OPCODE_NO_OPS:
217	FPRINTF (F, OP.name);
218	break;
219	case PDP11_OPCODE_REG:
220	FPRINTF (F, OP.name);
221	FPRINTF (F, AFTER_INSTRUCTION);
222	print_reg (dst, info);
223	break;
224	case PDP11_OPCODE_OP:
225	FPRINTF (F, OP.name);
226	FPRINTF (F, AFTER_INSTRUCTION);
227	if (strcmp (OP.name, "jmp") == 0)
228	dst \|= JUMP;
229	if (print_operand (&memaddr, dst, info) < 0)
230	return -1;
231	break;
232	case PDP11_OPCODE_REG_OP:
233	FPRINTF (F, OP.name);
234	FPRINTF (F, AFTER_INSTRUCTION);
235	print_reg (src, info);
236	FPRINTF (F, OPERAND_SEPARATOR);
237	if (strcmp (OP.name, "jsr") == 0)
238	dst \|= JUMP;
239	if (print_operand (&memaddr, dst, info) < 0)
240	return -1;
241	break;
242	case PDP11_OPCODE_REG_OP_REV:
243	FPRINTF (F, OP.name);
244	FPRINTF (F, AFTER_INSTRUCTION);
245	if (print_operand (&memaddr, dst, info) < 0)
246	return -1;
247	FPRINTF (F, OPERAND_SEPARATOR);
248	print_reg (src, info);
249	break;
250	case PDP11_OPCODE_AC_OP:
251	{
252	int ac = (opcode & 0xe0) >> 6;
253	FPRINTF (F, OP.name);
254	FPRINTF (F, AFTER_INSTRUCTION);
255	print_freg (ac, info);
256	FPRINTF (F, OPERAND_SEPARATOR);
257	if (print_operand (&memaddr, dst, info) < 0)
258	return -1;
259	break;
260	}
261	case PDP11_OPCODE_OP_OP:
262	FPRINTF (F, OP.name);
263	FPRINTF (F, AFTER_INSTRUCTION);
264	if (print_operand (&memaddr, src, info) < 0)
265	return -1;
266	FPRINTF (F, OPERAND_SEPARATOR);
267	if (print_operand (&memaddr, dst, info) < 0)
268	return -1;
269	break;
270	case PDP11_OPCODE_DISPL:
271	{
272	int displ = (opcode & 0xff) << 8;
273	bfd_vma address = memaddr + (sign_extend (displ) >> 7);
274	FPRINTF (F, OP.name);
275	FPRINTF (F, AFTER_INSTRUCTION);
276	(*info->print_address_func) (address, info);
277	break;
278	}
279	case PDP11_OPCODE_REG_DISPL:
280	{
281	int displ = (opcode & 0x3f) << 10;
282	bfd_vma address = memaddr + (sign_extend (displ) >> 9);
283	FPRINTF (F, OP.name);
284	FPRINTF (F, AFTER_INSTRUCTION);
285	print_reg (src, info);
286	FPRINTF (F, OPERAND_SEPARATOR);
287	(*info->print_address_func) (address, info);
288	break;
289	}
290	case PDP11_OPCODE_IMM8:
291	{
292	int code = opcode & 0xff;
293	FPRINTF (F, OP.name);
294	FPRINTF (F, AFTER_INSTRUCTION);
295	FPRINTF (F, "%o", code);
296	break;
297	}
298	case PDP11_OPCODE_IMM6:
299	{
300	int code = opcode & 0x3f;
301	FPRINTF (F, OP.name);
302	FPRINTF (F, AFTER_INSTRUCTION);
303	FPRINTF (F, "%o", code);
304	break;
305	}
306	case PDP11_OPCODE_IMM3:
307	{
308	int code = opcode & 7;
309	FPRINTF (F, OP.name);
310	FPRINTF (F, AFTER_INSTRUCTION);
311	FPRINTF (F, "%o", code);
312	break;
313	}
314	default:
315	/* TODO: is this a proper way of signalling an error? */
316	FPRINTF (F, "<internal error: unrecognized instruction type>");
317	return -1;
318	}
319	#undef OP
320	}
321
322	return memaddr - start_memaddr;
323	}