opcodes/pdp11-dis.c - binutils-gdb - Git at Google

 /* Print DEC PDP-11 instructions.
    Copyright (C) 2001-2023 Free Software Foundation, Inc.

    This file is part of the GNU opcodes library.

    This library 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 3, or (at your option)
    any later version.

    It 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., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */

 #include "sysdep.h"
 #include "disassemble.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_extend(x) ((((x) & 0xffff) ^ 0x8000) - 0x8000)

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

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

 static int
 print_operand (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 (mode == 7)
 	    FPRINTF (F, "*");
 	  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;
 }

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

   if (mode == 0)
     print_freg (reg, info);
   else
     return print_operand (memaddr, code, info);

   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 (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, "%s", OP.name);
 	    goto done;
 	  case PDP11_OPCODE_REG:
 	    FPRINTF (F, "%s", OP.name);
 	    FPRINTF (F, AFTER_INSTRUCTION);
 	    print_reg (dst, info);
 	    goto done;
 	  case PDP11_OPCODE_OP:
 	    FPRINTF (F, "%s", OP.name);
 	    FPRINTF (F, AFTER_INSTRUCTION);
 	    if (strcmp (OP.name, "jmp") == 0)
 	      dst |= JUMP;
 	    if (print_operand (&memaddr, dst, info) < 0)
 	      return -1;
 	    goto done;
 	  case PDP11_OPCODE_FOP:
 	    FPRINTF (F, "%s", OP.name);
 	    FPRINTF (F, AFTER_INSTRUCTION);
 	    if (strcmp (OP.name, "jmp") == 0)
 	      dst |= JUMP;
 	    if (print_foperand (&memaddr, dst, info) < 0)
 	      return -1;
 	    goto done;
 	  case PDP11_OPCODE_REG_OP:
 	    FPRINTF (F, "%s", 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;
 	    goto done;
 	  case PDP11_OPCODE_REG_OP_REV:
 	    FPRINTF (F, "%s", OP.name);
 	    FPRINTF (F, AFTER_INSTRUCTION);
 	    if (print_operand (&memaddr, dst, info) < 0)
 	      return -1;
 	    FPRINTF (F, OPERAND_SEPARATOR);
 	    print_reg (src, info);
 	    goto done;
 	  case PDP11_OPCODE_AC_FOP:
 	    {
 	      int ac = (opcode & 0xe0) >> 6;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      print_freg (ac, info);
 	      FPRINTF (F, OPERAND_SEPARATOR);
 	      if (print_foperand (&memaddr, dst, info) < 0)
 		return -1;
 	      goto done;
 	    }
 	  case PDP11_OPCODE_FOP_AC:
 	    {
 	      int ac = (opcode & 0xe0) >> 6;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      if (print_foperand (&memaddr, dst, info) < 0)
 		return -1;
 	      FPRINTF (F, OPERAND_SEPARATOR);
 	      print_freg (ac, info);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_AC_OP:
 	    {
 	      int ac = (opcode & 0xe0) >> 6;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      print_freg (ac, info);
 	      FPRINTF (F, OPERAND_SEPARATOR);
 	      if (print_operand (&memaddr, dst, info) < 0)
 		return -1;
 	      goto done;
 	    }
 	  case PDP11_OPCODE_OP_AC:
 	    {
 	      int ac = (opcode & 0xe0) >> 6;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      if (print_operand (&memaddr, dst, info) < 0)
 		return -1;
 	      FPRINTF (F, OPERAND_SEPARATOR);
 	      print_freg (ac, info);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_OP_OP:
 	    FPRINTF (F, "%s", 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;
 	    goto done;
 	  case PDP11_OPCODE_DISPL:
 	    {
 	      int displ = (opcode & 0xff) << 8;
 	      bfd_vma address = memaddr + (sign_extend (displ) >> 7);
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      (*info->print_address_func) (address, info);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_REG_DISPL:
 	    {
 	      int displ = (opcode & 0x3f) << 10;
 	      bfd_vma address = memaddr - (displ >> 9);

 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      print_reg (src, info);
 	      FPRINTF (F, OPERAND_SEPARATOR);
 	      (*info->print_address_func) (address, info);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_IMM8:
 	    {
 	      int code = opcode & 0xff;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      FPRINTF (F, "%o", code);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_IMM6:
 	    {
 	      int code = opcode & 0x3f;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      FPRINTF (F, "%o", code);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_IMM3:
 	    {
 	      int code = opcode & 7;
 	      FPRINTF (F, "%s", OP.name);
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      FPRINTF (F, "%o", code);
 	      goto done;
 	    }
 	  case PDP11_OPCODE_ILLEGAL:
 	    {
 	      FPRINTF (F, ".word");
 	      FPRINTF (F, AFTER_INSTRUCTION);
 	      FPRINTF (F, "%o", opcode);
 	      goto done;
 	    }
 	  default:
 	    /* TODO: is this a proper way of signalling an error? */
 	    FPRINTF (F, "<internal error: unrecognized instruction type>");
 	    return -1;
 	  }
 #undef OP
     }
  done:

   return memaddr - start_memaddr;
 }
	/* Print DEC PDP-11 instructions.
	Copyright (C) 2001-2023 Free Software Foundation, Inc.

	This file is part of the GNU opcodes library.

	This library 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 3, or (at your option)
	any later version.

	It 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., 51 Franklin Street - Fifth Floor, Boston,
	MA 02110-1301, USA. */

	#include "sysdep.h"
	#include "disassemble.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_extend(x) ((((x) & 0xffff) ^ 0x8000) - 0x8000)

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

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

	static int
	print_operand (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 (mode == 7)
	FPRINTF (F, "*");
	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;
	}

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

	if (mode == 0)
	print_freg (reg, info);
	else
	return print_operand (memaddr, code, info);

	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 (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, "%s", OP.name);
	goto done;
	case PDP11_OPCODE_REG:
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	print_reg (dst, info);
	goto done;
	case PDP11_OPCODE_OP:
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	if (strcmp (OP.name, "jmp") == 0)
	dst \|= JUMP;
	if (print_operand (&memaddr, dst, info) < 0)
	return -1;
	goto done;
	case PDP11_OPCODE_FOP:
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	if (strcmp (OP.name, "jmp") == 0)
	dst \|= JUMP;
	if (print_foperand (&memaddr, dst, info) < 0)
	return -1;
	goto done;
	case PDP11_OPCODE_REG_OP:
	FPRINTF (F, "%s", 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;
	goto done;
	case PDP11_OPCODE_REG_OP_REV:
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	if (print_operand (&memaddr, dst, info) < 0)
	return -1;
	FPRINTF (F, OPERAND_SEPARATOR);
	print_reg (src, info);
	goto done;
	case PDP11_OPCODE_AC_FOP:
	{
	int ac = (opcode & 0xe0) >> 6;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	print_freg (ac, info);
	FPRINTF (F, OPERAND_SEPARATOR);
	if (print_foperand (&memaddr, dst, info) < 0)
	return -1;
	goto done;
	}
	case PDP11_OPCODE_FOP_AC:
	{
	int ac = (opcode & 0xe0) >> 6;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	if (print_foperand (&memaddr, dst, info) < 0)
	return -1;
	FPRINTF (F, OPERAND_SEPARATOR);
	print_freg (ac, info);
	goto done;
	}
	case PDP11_OPCODE_AC_OP:
	{
	int ac = (opcode & 0xe0) >> 6;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	print_freg (ac, info);
	FPRINTF (F, OPERAND_SEPARATOR);
	if (print_operand (&memaddr, dst, info) < 0)
	return -1;
	goto done;
	}
	case PDP11_OPCODE_OP_AC:
	{
	int ac = (opcode & 0xe0) >> 6;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	if (print_operand (&memaddr, dst, info) < 0)
	return -1;
	FPRINTF (F, OPERAND_SEPARATOR);
	print_freg (ac, info);
	goto done;
	}
	case PDP11_OPCODE_OP_OP:
	FPRINTF (F, "%s", 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;
	goto done;
	case PDP11_OPCODE_DISPL:
	{
	int displ = (opcode & 0xff) << 8;
	bfd_vma address = memaddr + (sign_extend (displ) >> 7);
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	(*info->print_address_func) (address, info);
	goto done;
	}
	case PDP11_OPCODE_REG_DISPL:
	{
	int displ = (opcode & 0x3f) << 10;
	bfd_vma address = memaddr - (displ >> 9);

	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	print_reg (src, info);
	FPRINTF (F, OPERAND_SEPARATOR);
	(*info->print_address_func) (address, info);
	goto done;
	}
	case PDP11_OPCODE_IMM8:
	{
	int code = opcode & 0xff;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	FPRINTF (F, "%o", code);
	goto done;
	}
	case PDP11_OPCODE_IMM6:
	{
	int code = opcode & 0x3f;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	FPRINTF (F, "%o", code);
	goto done;
	}
	case PDP11_OPCODE_IMM3:
	{
	int code = opcode & 7;
	FPRINTF (F, "%s", OP.name);
	FPRINTF (F, AFTER_INSTRUCTION);
	FPRINTF (F, "%o", code);
	goto done;
	}
	case PDP11_OPCODE_ILLEGAL:
	{
	FPRINTF (F, ".word");
	FPRINTF (F, AFTER_INSTRUCTION);
	FPRINTF (F, "%o", opcode);
	goto done;
	}
	default:
	/* TODO: is this a proper way of signalling an error? */
	FPRINTF (F, "<internal error: unrecognized instruction type>");
	return -1;
	}
	#undef OP
	}
	done:

	return memaddr - start_memaddr;
	}