/* tc-pdp11.c - pdp11-specific -
   Copyright 2001 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS 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, or (at your option)
   any later version.

   GAS 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 GAS; see the file COPYING.  If not, write to
   the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/*
  Apparently unused functions:
    md_convert_frag
    md_estimate_size_before_relax
    md_create_short_jump
    md_create_long_jump
*/

#include "as.h"
#include "safe-ctype.h"
#include "opcode/pdp11.h"

static int set_option PARAMS ((char *arg));
static int set_cpu_model PARAMS ((char *arg));
static int set_machine_model PARAMS ((char *arg));

#define TRUE 1
#define FALSE 0

/*
 * A representation for PDP-11 machine code.
 */
struct pdp11_code
{
  char *error;
  int code;
  int additional;	/* is there an additional word? */
  int word;		/* additional word, if any */
  struct
  {
    bfd_reloc_code_real_type type;
    expressionS exp;
    int pc_rel;
  } reloc;
};

/*
 * Instruction set extensions.
 *
 * If you change this from an array to something else, please update
 * the "PDP-11 instruction set extensions" comment in pdp11.h.
 */
int pdp11_extension[PDP11_EXT_NUM];

/*
 * Assembly options.
 */

#define ASM_OPT_PIC 1
#define ASM_OPT_NUM 2

int asm_option[ASM_OPT_NUM];

/* These chars start a comment anywhere in a source file (except inside
   another comment */
CONST char comment_chars[] = "#/";

/* These chars only start a comment at the beginning of a line.  */
CONST char line_comment_chars[] = "#/";

CONST char line_separator_chars[] = ";";

/* Chars that can be used to separate mant from exp in floating point nums */
CONST char EXP_CHARS[] = "eE";

/* Chars that mean this number is a floating point constant */
/* as in 0f123.456 */
/* or    0H1.234E-12 (see exp chars above) */
CONST char FLT_CHARS[] = "dDfFgGhH";

void pseudo_even (int);
void pseudo_bss (int);

CONST pseudo_typeS md_pseudo_table[] =
{
  { "bss", pseudo_bss, 0 },
  { "even", pseudo_even, 0 },
  { 0, 0, 0 },
};

static void
init_defaults ()
{
  static int first = 1;

  if (first)
    {
      set_option ("all-extensions");
      set_option ("pic");
      first = 0;
    }
}

static struct hash_control *insn_hash = NULL;

void
md_begin ()
{
  int i;

  init_defaults ();

  insn_hash = hash_new ();
  if (insn_hash == NULL)
    as_fatal ("Virtual memory exhausted");

  for (i = 0; i < pdp11_num_opcodes; i++)
    hash_insert (insn_hash, pdp11_opcodes[i].name, (PTR)(pdp11_opcodes + i));
  for (i = 0; i < pdp11_num_aliases; i++)
    hash_insert (insn_hash, pdp11_aliases[i].name, (PTR)(pdp11_aliases + i));
}

void
md_number_to_chars (con, value, nbytes)
     char con[];
     valueT value;
     int nbytes;
{
  /* On a PDP-11, 0x1234 is stored as "\x12\x34", and
   * 0x12345678 is stored as "\x56\x78\x12\x34". It's
   * anyones guess what 0x123456 would be stored like.
   */

  switch (nbytes)
    {
    case 0:
      break;
    case 1:
      con[0] =  value       & 0xff;
      break;
    case 2:
      con[0] =  value       & 0xff;
      con[1] = (value >>  8) & 0xff;
      break;
    case 4:
      con[0] = (value >> 16) & 0xff;
      con[1] = (value >> 24) & 0xff;
      con[2] =  value       & 0xff;
      con[3] = (value >>  8) & 0xff;
      break;
    default:
      BAD_CASE (nbytes);
    }
}

/* Fix up some data or instructions after we find out the value of a symbol
   that they reference.  Knows about order of bytes in address.  */

void
md_apply_fix3 (fixP, valP, seg)
     fixS *fixP;
     valueT * valP;
     segT seg ATTRIBUTE_UNUSED;
{
  valueT code;
  valueT mask;
  valueT val = * valP;
  char *buf;
  int shift;
  int size;

  buf = fixP->fx_where + fixP->fx_frag->fr_literal;
  size = fixP->fx_size;
  code = md_chars_to_number (buf, size);

  switch (fixP->fx_r_type)
    {
    case BFD_RELOC_16:
    case BFD_RELOC_16_PCREL:
      mask = 0xffff;
      shift = 0;
      break;
    case BFD_RELOC_PDP11_DISP_8_PCREL:
      mask = 0x00ff;
      shift = 1;
      break;
    case BFD_RELOC_PDP11_DISP_6_PCREL:
      mask = 0x003f;
      shift = 1;
      break;
    default:
      BAD_CASE (fixP->fx_r_type);
    }

  if (fixP->fx_addsy != NULL)
    val += symbol_get_bfdsym (fixP->fx_addsy)->section->vma;
    /* *value += fixP->fx_addsy->bsym->section->vma; */

  code &= ~mask;
  code |= (val >> shift) & mask;
  number_to_chars_littleendian (buf, code, size);

  if (fixP->fx_addsy == NULL && fixP->fx_pcrel == 0)
    fixP->fx_done = 1;
}

long
md_chars_to_number (con, nbytes)
     unsigned char con[];	/* Low order byte 1st.  */
     int nbytes;		/* Number of bytes in the input.  */
{
  /* On a PDP-11, 0x1234 is stored as "\x12\x34", and
   * 0x12345678 is stored as "\x56\x78\x12\x34". It's
   * anyones guess what 0x123456 would be stored like.
   */

  switch (nbytes)
    {
    case 0:
      return 0;
    case 1:
      return con[0];
    case 2:
      return (con[1] << BITS_PER_CHAR) | con[0];
    case 4:
      return
	(((con[1] << BITS_PER_CHAR) | con[0]) << (2 * BITS_PER_CHAR)) |
	 ((con[3] << BITS_PER_CHAR) | con[2]);
    default:
      BAD_CASE (nbytes);
      return 0;
    }
}

static char *
skip_whitespace (char *str)
{
  while (*str == ' ' || *str == '\t')
    str++;
  return str;
}

static char *
find_whitespace (char *str)
{
  while (*str != ' ' && *str != '\t' && *str != 0)
    str++;
  return str;
}

static char *
parse_reg (char *str, struct pdp11_code *operand)
{
  str = skip_whitespace (str);
  if (TOLOWER (*str) == 'r')
    {
      str++;
      switch (*str)
	{
	case '0': case '1': case '2': case '3':
	case '4': case '5': case '6': case '7':
	  operand->code = *str - '0';
	  str++;
	  break;
	default:
	  operand->error = "Bad register name";
	  return str - 1;
	}
    }
  else if (strncmp (str, "sp", 2) == 0 ||
	   strncmp (str, "SP", 2) == 0)
    {
      operand->code = 6;
      str += 2;
    }
  else if (strncmp (str, "pc", 2) == 0 ||
	   strncmp (str, "PC", 2) == 0)
    {
      operand->code = 7;
      str += 2;
    }
  else
    {
      operand->error = "Bad register name";
      return str;
    }

  return str;
}

static char *
parse_ac (char *str, struct pdp11_code *operand)
{
  str = skip_whitespace (str);
  if (strncmp (str, "fr", 2) == 0 ||
      strncmp (str, "FR", 2) == 0 ||
      strncmp (str, "ac", 2) == 0 ||
      strncmp (str, "AC", 2) == 0)
    {
      str += 2;
      switch (*str)
	{
	case '0': case '1': case '2': case '3':
	  operand->code = *str - '0';
	  str++;
	  break;
	default:
	  operand->error = "Bad register name";
	  return str - 2;
	}
    }
  else
    {
      operand->error = "Bad register name";
      return str;
    }

  return str;
}

static char *
parse_expression (char *str, struct pdp11_code *operand)
{
  char *save_input_line_pointer;
  segT seg;

  save_input_line_pointer = input_line_pointer;
  input_line_pointer = str;
  seg = expression (&operand->reloc.exp);
  if (seg == NULL)
    {
      input_line_pointer = save_input_line_pointer;
      operand->error = "Error in expression";
      return str;
    }

  str = input_line_pointer;
  input_line_pointer = save_input_line_pointer;

  operand->reloc.pc_rel = 0;

  if (operand->reloc.exp.X_op == O_constant)
    {
      if (*str == '.')
	str++;
      else
	{
	  /* FIXME: buffer overflow! */
	  char buf[100];
	  char *end;

	  sprintf (buf, "%ld", operand->reloc.exp.X_add_number);
	  operand->reloc.exp.X_add_number = strtol (buf, &end, 8);
	}
    }

  return str;
}

static char *
parse_op_no_deferred (char *str, struct pdp11_code *operand)
{
  str = skip_whitespace (str);

  switch (*str)
    {
    case '(':				/* (rn) and (rn)+ */
      str = parse_reg (str + 1, operand);
      if (operand->error)
	return str;
      str = skip_whitespace (str);
      if (*str != ')')
	{
	  operand->error = "Missing ')'";
	  return str;
	}
      str++;
      if (*str == '+')
	{
	  operand->code |= 020;
	  str++;
	}
      else
	{
	  operand->code |= 010;
	}
      break;

    case '#':				/* immediate */
    case '$':
      str = parse_expression (str + 1, operand);
      if (operand->error)
	return str;
      operand->additional = TRUE;
      operand->word = operand->reloc.exp.X_add_number;
      switch (operand->reloc.exp.X_op)
	{
	case O_constant:
	  break;
	case O_symbol:
	case O_add:
	case O_subtract:
	  operand->reloc.type = BFD_RELOC_16;
	  operand->reloc.pc_rel = 0;
	  break;
	default:
	  operand->error = "Error in expression";
	  break;
	}
      operand->code = 027;
      break;

    default:				/* label, d(rn), -(rn) */
      {
	char *old = str;

	if (strncmp (str, "-(", 2) == 0)	/* -(rn) */
	  {
	    str = parse_reg (str + 2, operand);
	    if (operand->error)
	      return str;
	    str = skip_whitespace (str);
	    if (*str != ')')
	      {
		operand->error = "Missing ')'";
		return str;
	      }
	    operand->code |= 040;
	    str++;
	    break;
	  }

	str = parse_expression (str, operand);
	if (operand->error)
	  return str;

	str = skip_whitespace (str);

	if (*str != '(')		/* label */
	  {
	    if (operand->reloc.exp.X_op != O_symbol)
	      {
		operand->error = "Label expected";
		return old;
	      }
	    operand->code = 067;
	    operand->additional = 1;
	    operand->word = 0;
	    operand->reloc.type = BFD_RELOC_16_PCREL;
	    operand->reloc.pc_rel = 1;
	    break;
	  }

	str++;				/* d(rn) */
	str = parse_reg (str, operand);
	if (operand->error)
	  return str;

	str = skip_whitespace (str);

	if (*str != ')')
	  {
	    operand->error = "Missing ')'";
	    return str;
	  }

	str++;
	operand->additional = TRUE;
	operand->code |= 060;
	switch (operand->reloc.exp.X_op)
	  {
	  case O_symbol:
	    operand->word = 0;
	    operand->reloc.pc_rel = 1;
	    break;
	  case O_constant:
	    if ((operand->code & 7) == 7)
	      {
		operand->reloc.pc_rel = 1;
		operand->word = operand->reloc.exp.X_add_number;
	      }
	    else
	      {
		operand->word = operand->reloc.exp.X_add_number;
	      }
	    break;
	  default:
	    BAD_CASE (operand->reloc.exp.X_op);
	  }
	break;
      }
    }

  return str;
}

static char *
parse_op (char *str, struct pdp11_code *operand)
{
  str = skip_whitespace (str);

  str = parse_reg (str, operand);
  if (!operand->error)
    return str;
  operand->error = NULL;

  if (*str == '@' || *str == '*')
    {
      str = parse_op_no_deferred (str + 1, operand);
      if (operand->error)
	return str;
      operand->code |= 010;
    }
  else
    str = parse_op_no_deferred (str, operand);

  return str;
}

static char *
parse_separator (char *str, int *error)
{
  str = skip_whitespace (str);
  *error = (*str != ',');
  if (!*error)
    str++;
  return str;
}

void
md_assemble (instruction_string)
     char *instruction_string;
{
  CONST struct pdp11_opcode *op;
  struct pdp11_code insn, op1, op2;
  int error;
  int size;
  char *err = NULL;
  char *str;
  char *p;
  char c;

  str = skip_whitespace (instruction_string);
  p = find_whitespace (str);
  if (p - str == 0)
    {
      as_bad ("No instruction found");
      return;
    }

  c = *p;
  *p = '\0';
  op = (struct pdp11_opcode *)hash_find (insn_hash, str);
  *p = c;
  if (op == 0)
    {
#if 0
      op1.error = NULL;
      op1.additional = FALSE;
      op1.reloc.type = BFD_RELOC_NONE;
      op1.code = 0;
      op1.word = 0;
      str = parse_expression (str, &op1);
      if (op1.error)
	{
	  as_bad (op1.error);
	  return;
	}

      {
	char *to = frag_more (2);

	md_number_to_chars (to, op1.code, 2);
	if (insn.reloc.type != BFD_RELOC_NONE)
	  fix_new_exp (frag_now, to - frag_now->fr_literal, 2,
		       &insn.reloc.exp, insn.reloc.pc_rel, insn.reloc.type);
      }
#else
      as_warn ("Unknown instruction");
#endif

      return;
    }

  if (!pdp11_extension[op->extension])
    {
      as_warn ("Unsupported instruction set extension: %s", op->name);
      return;
    }

  insn.error = NULL;
  insn.code = op->opcode;
  insn.reloc.type = BFD_RELOC_NONE;
  op1.error = NULL;
  op1.additional = FALSE;
  op1.reloc.type = BFD_RELOC_NONE;
  op2.error = NULL;
  op2.additional = FALSE;
  op2.reloc.type = BFD_RELOC_NONE;

  str = p;
  size = 2;

  switch (op->type)
    {
    case PDP11_OPCODE_NO_OPS:
      str = skip_whitespace (str);
      if (*str == 0)
	str = "";
      break;

    case PDP11_OPCODE_IMM3:
    case PDP11_OPCODE_IMM6:
    case PDP11_OPCODE_IMM8:
      str = skip_whitespace (str);
      if (*str == '#' || *str == '$')
	str++;
      str = parse_expression (str, &op1);
      if (op1.error)
	break;
      switch (op->type)
	{
	case PDP11_OPCODE_IMM3:
	  if (op1.code & ~7)
	    {
	      op1.error = "3-bit immediate out of range";
	      break;
	    }
	  break;
	case PDP11_OPCODE_IMM6:
	  if (op1.code & ~0x3f)
	    {
	      op1.error = "6-bit immediate out of range";
	      break;
	    }
	  break;
	case PDP11_OPCODE_IMM8:
	  if (op1.code & ~0xff)
	    {
	      op1.error = "8-bit immediate out of range";
	      break;
	    }
	  break;
	}
      insn.code |= op1.code;
      break;

    case PDP11_OPCODE_DISPL:
      {
	char *new;
	new = parse_expression (str, &op1);
	op1.code = 0;
	op1.reloc.pc_rel = 1;
	op1.reloc.type = BFD_RELOC_PDP11_DISP_8_PCREL;
	if (op1.reloc.exp.X_op != O_symbol)
	  {
	    op1.error = "Symbol expected";
	    break;
	  }
	if (op1.code & ~0xff)
	  {
	    err = "8-bit displacement out of range";
	    break;
	  }
	str = new;
	insn.code |= op1.code;
	insn.reloc = op1.reloc;
      }
      break;

    case PDP11_OPCODE_REG:
      str = parse_reg (str, &op1);
      if (op1.error)
	break;
      insn.code |= op1.code;
      break;

    case PDP11_OPCODE_OP:
      str = parse_op (str, &op1);
      if (op1.error)
	break;
      insn.code |= op1.code;
      if (op1.additional)
	size += 2;
      break;

    case PDP11_OPCODE_REG_OP:
      str = parse_reg (str, &op2);
      if (op2.error)
	break;
      insn.code |= op2.code << 6;
      str = parse_separator (str, &error);
      if (error)
	{
	  op2.error = "Missing ','";
	  break;
	}
      str = parse_op (str, &op1);
      if (op1.error)
	break;
      insn.code |= op1.code;
      if (op1.additional)
	size += 2;
      break;

    case PDP11_OPCODE_REG_OP_REV:
      str = parse_op (str, &op1);
      if (op1.error)
	break;
      insn.code |= op1.code;
      if (op1.additional)
	size += 2;
      str = parse_separator (str, &error);
      if (error)
	{
	  op2.error = "Missing ','";
	  break;
	}
      str = parse_reg (str, &op2);
      if (op2.error)
	break;
      insn.code |= op2.code << 6;
      break;

    case PDP11_OPCODE_AC_OP:
      str = parse_ac (str, &op2);
      if (op2.error)
	break;
      insn.code |= op2.code << 6;
      str = parse_separator (str, &error);
      if (error)
	{
	  op1.error = "Missing ','";
	  break;
	}
      str = parse_op (str, &op1);
      if (op1.error)
	break;
      insn.code |= op1.code;
      if (op1.additional)
	size += 2;
      break;

    case PDP11_OPCODE_OP_OP:
      str = parse_op (str, &op1);
      if (op1.error)
	break;
      insn.code |= op1.code << 6;
      if (op1.additional)
	size += 2;
      str = parse_separator (str, &error);
      if (error)
	{
	  op2.error = "Missing ','";
	  break;
	}
      str = parse_op (str, &op2);
      if (op2.error)
	break;
      insn.code |= op2.code;
      if (op2.additional)
	size += 2;
      break;

    case PDP11_OPCODE_REG_DISPL:
      {
	char *new;
	str = parse_reg (str, &op2);
	if (op2.error)
	  break;
	insn.code |= op2.code << 6;
	str = parse_separator (str, &error);
	if (error)
	  {
	    op1.error = "Missing ','";
	    break;
	  }
	new = parse_expression (str, &op1);
	op1.code = 0;
	op1.reloc.pc_rel = 1;
	op1.reloc.type = BFD_RELOC_PDP11_DISP_6_PCREL;
	if (op1.reloc.exp.X_op != O_symbol)
	  {
	    op1.error = "Symbol expected";
	    break;
	  }
	if (op1.code & ~0x3f)
	  {
	    err = "6-bit displacement out of range";
	    break;
	  }
	str = new;
	insn.code |= op1.code;
	insn.reloc = op1.reloc;
      }
      break;

    default:
      BAD_CASE (op->type);
    }

  if (op1.error)
    err = op1.error;
  else if (op2.error)
    err = op2.error;
  else
    {
      str = skip_whitespace (str);
      if (*str)
	err = "Too many operands";
    }

  {
    char *to = NULL;

    if (err)
      {
	as_bad (err);
	return;
      }

    to = frag_more (size);

    md_number_to_chars (to, insn.code, 2);
    if (insn.reloc.type != BFD_RELOC_NONE)
      fix_new_exp (frag_now, to - frag_now->fr_literal, 2,
		   &insn.reloc.exp, insn.reloc.pc_rel, insn.reloc.type);
    to += 2;

    if (op1.additional)
      {
	md_number_to_chars (to, op1.word, 2);
	if (op1.reloc.type != BFD_RELOC_NONE)
	  fix_new_exp (frag_now, to - frag_now->fr_literal, 2,
		       &op1.reloc.exp, op1.reloc.pc_rel, op1.reloc.type);
	to += 2;
      }

    if (op2.additional)
      {
	md_number_to_chars (to, op2.word, 2);
	if (op2.reloc.type != BFD_RELOC_NONE)
	  fix_new_exp (frag_now, to - frag_now->fr_literal, 2,
		       &op2.reloc.exp, op2.reloc.pc_rel, op2.reloc.type);
      }
  }
}

int
md_estimate_size_before_relax (fragP, segment)
     fragS *fragP ATTRIBUTE_UNUSED;
     segT segment ATTRIBUTE_UNUSED;
{
  return 0;
}

void
md_convert_frag (headers, seg, fragP)
     bfd *headers ATTRIBUTE_UNUSED;
     segT seg ATTRIBUTE_UNUSED;
     fragS *fragP ATTRIBUTE_UNUSED;
{
}

CONST int md_short_jump_size = 2;
CONST int md_long_jump_size = 4;

void
md_create_short_jump (ptr, from_addr, to_addr, frag, to_symbol)
     char *ptr ATTRIBUTE_UNUSED;
     addressT from_addr ATTRIBUTE_UNUSED;
     addressT to_addr ATTRIBUTE_UNUSED;
     fragS *frag ATTRIBUTE_UNUSED;
     symbolS *to_symbol ATTRIBUTE_UNUSED;
{
}

void
md_create_long_jump (ptr, from_addr, to_addr, frag, to_symbol)
     char *ptr ATTRIBUTE_UNUSED;
     addressT from_addr ATTRIBUTE_UNUSED;
     addressT to_addr ATTRIBUTE_UNUSED;
     fragS *frag ATTRIBUTE_UNUSED;
     symbolS *to_symbol ATTRIBUTE_UNUSED;
{
}

static int
set_option (arg)
     char *arg;
{
  int yes = 1;

  if (strcmp (arg, "all-extensions") == 0 ||
      strcmp (arg, "all") == 0)
    {
      memset (pdp11_extension, ~0, sizeof pdp11_extension);
      pdp11_extension[PDP11_NONE] = 0;
      return 1;
    }
  else if (strcmp (arg, "no-extensions") == 0)
    {
      memset (pdp11_extension, 0, sizeof pdp11_extension);
      pdp11_extension[PDP11_BASIC] = 1;
      return 1;
    }

  if (strncmp (arg, "no-", 3) == 0)
    {
      yes = 0;
      arg += 3;
    }

  if (strcmp (arg, "cis") == 0)			/* commersial instructions */
    pdp11_extension[PDP11_CIS] = yes;
  else if (strcmp (arg, "csm") == 0)		/* call supervisor mode */
    pdp11_extension[PDP11_CSM] = yes;
  else if (strcmp (arg, "eis") == 0)		/* extended instruction set */
    pdp11_extension[PDP11_EIS] = pdp11_extension[PDP11_LEIS] = yes;
  else if (strcmp (arg, "fis") == 0 ||		/* KEV11 floating-point */
	   strcmp (arg, "kev11") == 0 ||
	   strcmp (arg, "kev-11") == 0)
    pdp11_extension[PDP11_FIS] = yes;
  else if (strcmp (arg, "fpp") == 0 ||		/* FP-11 floating-point */
	   strcmp (arg, "fpu") == 0 ||
	   strcmp (arg, "fp11") == 0 ||
	   strcmp (arg, "fp-11") == 0 ||
	   strcmp (arg, "fpj11") == 0 ||
	   strcmp (arg, "fp-j11") == 0 ||
	   strcmp (arg, "fpj-11") == 0)
    pdp11_extension[PDP11_FPP] = yes;
  else if (strcmp (arg, "limited-eis") == 0)	/* limited extended insns */
    {
      pdp11_extension[PDP11_LEIS] = yes;
      if (!pdp11_extension[PDP11_LEIS])
	pdp11_extension[PDP11_EIS] = 0;
    }
  else if (strcmp (arg, "mfpt") == 0)		/* move from processor type */
    pdp11_extension[PDP11_MFPT] = yes;
  else if (strncmp (arg, "mproc", 5) == 0 ||	/* multiprocessor insns: */
	   strncmp (arg, "multiproc", 9) == 0 )	/* TSTSET, WRTLCK */
    pdp11_extension[PDP11_MPROC] = yes;
  else if (strcmp (arg, "mxps") == 0)		/* move from/to proc status */
    pdp11_extension[PDP11_MXPS] = yes;
  else if (strcmp (arg, "pic") == 0)		/* position-independent code */
    asm_option[ASM_OPT_PIC] = yes;
  else if (strcmp (arg, "spl") == 0)		/* set priority level */
    pdp11_extension[PDP11_SPL] = yes;
  else if (strcmp (arg, "ucode") == 0 ||	/* microcode instructions: */
	   strcmp (arg, "microcode") == 0)	/* LDUB, MED, XFC */
    pdp11_extension[PDP11_UCODE] = yes;
  else
    return 0;

  return 1;
}

static int
set_cpu_model (arg)
     char *arg;
{
  char buf[4];
  char *model = buf;

  if (arg[0] == 'k')
    arg++;

  *model++ = *arg++;

  if (strchr ("abdx", model[-1]) == NULL)
    return 0;

  if (model[-1] == 'd')
    {
      if (arg[0] == 'f' ||
	  arg[0] == 'j')
	model[-1] = *arg++;
    }
  else if (model[-1] == 'x')
    {
      if (arg[0] == 't')
	model[-1] = *arg++;
    }

  if (arg[0] == '-')
    arg++;

  if (strncmp (arg, "11", 2) != 0)
    return 0;
  arg += 2;

  if (arg[0] == '-')
    {
      if (*++arg == 0)
	return 0;
    }

  /* allow up to two revision letters */
  if (arg[0] != 0)
    *model++ = *arg++;
  if (arg[0] != 0)
    *model++ = *arg++;

  *model++ = 0;

  set_option ("no-extensions");

  if (strncmp (buf, "a", 1) == 0)		/* KA11 (11/15/20) */
    return 1; /* no extensions */

  else if (strncmp (buf, "b", 1) == 0)		/* KB11 (11/45/50/55/70) */
    return set_option ("eis") &&
           set_option ("spl");

  else if (strncmp (buf, "da", 2) == 0)		/* KD11-A (11/35/40) */
    return set_option ("limited-eis");

  else if (strncmp (buf, "db", 2) == 0 ||	/* KD11-B (11/05/10) */
	   strncmp (buf, "dd", 2) == 0)		/* KD11-D (11/04) */
    return 1; /* no extensions */

  else if (strncmp (buf, "de", 2) == 0)		/* KD11-E (11/34) */
    return set_option ("eis") &&
           set_option ("mxps");

  else if (strncmp (buf, "df", 2) == 0 ||	/* KD11-F (11/03) */
	   strncmp (buf, "dh", 2) == 0 ||	/* KD11-H (11/03) */
	   strncmp (buf, "dq", 2) == 0)		/* KD11-Q (11/03) */
    return set_option ("limited-eis") &&
           set_option ("mxps");

  else if (strncmp (buf, "dk", 2) == 0)		/* KD11-K (11/60) */
    return set_option ("eis") &&
           set_option ("mxps") &&
           set_option ("ucode");

  else if (strncmp (buf, "dz", 2) == 0)		/* KD11-Z (11/44) */
    return set_option ("csm") &&
           set_option ("eis") &&
           set_option ("mfpt") &&
           set_option ("mxps") &&
           set_option ("spl");

  else if (strncmp (buf, "f", 1) == 0)		/* F11 (11/23/24) */
    return set_option ("eis") &&
           set_option ("mfpt") &&
           set_option ("mxps");

  else if (strncmp (buf, "j", 1) == 0)		/* J11 (11/53/73/83/84/93/94)*/
    return set_option ("csm") &&
           set_option ("eis") &&
           set_option ("mfpt") &&
           set_option ("multiproc") &&
           set_option ("mxps") &&
           set_option ("spl");

  else if (strncmp (buf, "t", 1) == 0)		/* T11 (11/21) */
    return set_option ("limited-eis") &&
           set_option ("mxps");

  else
    return 0;
}

static int
set_machine_model (arg)
     char *arg;
{
  if (strncmp (arg, "pdp-11/", 7) != 0 &&
      strncmp (arg, "pdp11/", 6) != 0 &&
      strncmp (arg, "11/", 3) != 0)
    return 0;

  if (strncmp (arg, "pdp", 3) == 0)
    arg += 3;
  if (arg[0] == '-')
    arg++;
  if (strncmp (arg, "11/", 3) == 0)
    arg += 3;

  if (strcmp (arg, "03") == 0)			/* 11/03 */
    return set_cpu_model ("kd11f");		/* KD11-F */

  else if (strcmp (arg, "04") == 0)		/* 11/04 */
    return set_cpu_model ("kd11d");		/* KD11-D */

  else if (strcmp (arg, "05") == 0 ||		/* 11/05 or 11/10 */
	   strcmp (arg, "10") == 0)
    return set_cpu_model ("kd11b");		/* KD11-B */

  else if (strcmp (arg, "15") == 0 ||		/* 11/15 or 11/20 */
	   strcmp (arg, "20") == 0)
    return set_cpu_model ("ka11");		/* KA11 */

  else if (strcmp (arg, "21") == 0)		/* 11/21 */
    return set_cpu_model ("t11");		/* T11 */

  else if (strcmp (arg, "23") == 0 ||		/* 11/23 or 11/24 */
	   strcmp (arg, "24") == 0)
    return set_cpu_model ("f11");		/* F11 */

  else if (strcmp (arg, "34") == 0 ||		/* 11/34 or 11/34a */
           strcmp (arg, "34a") == 0)
    return set_cpu_model ("kd11e");		/* KD11-E */

  else if (strcmp (arg, "35") == 0 ||		/* 11/35 or 11/40 */
	   strcmp (arg, "40") == 0)
    return set_cpu_model ("kd11da");		/* KD11-A */

  else if (strcmp (arg, "44") == 0)		/* 11/44 */
    return set_cpu_model ("kd11dz");		/* KD11-Z */

  else if (strcmp (arg, "45") == 0 ||		/* 11/45/50/55/70 */
	   strcmp (arg, "50") == 0 ||
	   strcmp (arg, "55") == 0 ||
	   strcmp (arg, "70") == 0)
    return set_cpu_model ("kb11");		/* KB11 */

  else if (strcmp (arg, "60") == 0)		/* 11/60 */
    return set_cpu_model ("kd11k");		/* KD11-K */ /* FPP? */

  else if (strcmp (arg, "53") == 0 ||		/* 11/53/73/83/84/93/94 */
	   strcmp (arg, "73") == 0 ||
	   strcmp (arg, "83") == 0 ||
	   strcmp (arg, "84") == 0 ||
	   strcmp (arg, "93") == 0 ||
	   strcmp (arg, "94") == 0)
    return set_cpu_model ("j11") &&		/* J11 */
           set_option ("fpp");			/* All J11 machines come */
						/* with FPP installed.  */
  else
    return 0;
}

CONST char *md_shortopts = "m:";

struct option md_longopts[] =
{
#define OPTION_CPU 257
  { "cpu", required_argument, NULL, OPTION_CPU },
#define OPTION_MACHINE 258
  { "machine", required_argument, NULL, OPTION_MACHINE },
#define OPTION_PIC 259
  { "pic", no_argument, NULL, OPTION_PIC },
  { NULL, no_argument, NULL, 0 }
};

size_t md_longopts_size = sizeof (md_longopts);

/*
 * md_parse_option
 *	Invocation line includes a switch not recognized by the base assembler.
 *	See if it's a processor-specific option.
 */

int
md_parse_option (c, arg)
     int c;
     char *arg;
{
  init_defaults ();

  switch (c)
    {
    case 'm':
      if (set_option (arg))
	return 1;
      if (set_cpu_model (arg))
	return 1;
      if (set_machine_model (arg))
	return 1;
      break;

    case OPTION_CPU:
      if (set_cpu_model (arg))
	return 1;
      break;

    case OPTION_MACHINE:
      if (set_machine_model (arg))
	return 1;
      break;

    case OPTION_PIC:
      if (set_option ("pic"))
	return 1;
      break;

    default:
      break;
    }

  as_bad ("unrecognized option `-%c%s'", c, arg ? arg : "");

  return 0;
}

/*
One possible way of parsing options.

enum
{
  OPTION_CSM,
  OPTION_CIS,
  ...
};

struct
{
  CONST char *pattern;
  int opt;
  CONST char *description;
} options;

static struct options extension_opts[] =
{
  { "Ncsm", OPTION_CSM,
			"allow (disallow) CSM instruction" },
  { "Ncis", OPTION_CIS,
			"allow (disallow) commersial instruction set" },
  { "Neis", OPTION_EIS,
			"allow (disallow) extended instruction set" },
  ...
  { "all-extensions", OPTION_ALL_EXTENSIONS,
			"allow all instruction set extensions\n\
			(this is the default)" },
  { "no-extensions", OPTION_NO_EXTENSIONS,
			"disallow all instruction set extensions" },
  { "pic", OPTION_PIC,
			"position-independent code" },
};

static struct options cpu_opts[] =
{
  { "Ka_11_*", OPTION_KA11, "KA11 CPU. ..." },
  { "Kb_11_*", OPTION_KB11, "KB11 CPU. ..." },
  { "Kd_11_a*", OPTION_KD11A, "KD11-A CPU. ..." },
  { "Kd_11_b*", OPTION_KD11B, "KD11-B CPU. ..." },
  { "Kd_11_d*", OPTION_KD11D, "KD11-D CPU. ..." },
  { "Kd_11_e*", OPTION_KD11E, "KD11-E CPU. ..." },
  { "Kd_11_f*", OPTION_KD11F, "KD11-F CPU. ..." },
  { "Kd_11_h*", OPTION_KD11H, "KD11-H CPU. ..." },
  { "Kd_11_q*", OPTION_KD11Q, "KD11-Q CPU. ..." },
  { "Kd_11_z*", OPTION_KD11Z, "KD11-Z CPU. ..." },
  { "Df_11_*", OPTION_F11, "F11 CPU. ..." },
  { "Dj_11_*", OPTION_J11, "J11 CPU. ..." },
  { "Dt_11_*", OPTION_T11, "T11 CPU. ..." },
};

static struct options model_opts[] =
{
  { "P03", OPTION_PDP11_03, "same as ..." },
  { "P04", OPTION_PDP11_04, "same as ..." },
  { "P05", OPTION_PDP11_05, "same as ..." },
  { "P10", OPTION_PDP11_10, "same as ..." },
  { "P15", OPTION_PDP11_15, "same as ..." },
  { "P20", OPTION_PDP11_20, "same as ..." },
  { "P21", OPTION_PDP11_21, "same as ..." },
  { "P24", OPTION_PDP11_24, "same as ..." },
  { "P34", OPTION_PDP11_34, "same as ..." },
  { "P34a", OPTION_PDP11_34A, "same as ..." },
  { "P40", OPTION_PDP11_40, "same as ..." },
  { "P44", OPTION_PDP11_44, "same as ..." },
  { "P45", OPTION_PDP11_45, "same as ..." },
  { "P50", OPTION_PDP11_50, "same as ..." },
  { "P53", OPTION_PDP11_53, "same as ..." },
  { "P55", OPTION_PDP11_55, "same as ..." },
  { "P60", OPTION_PDP11_60, "same as ..." },
  { "P70", OPTION_PDP11_70, "same as ..." },
  { "P73", OPTION_PDP11_73, "same as ..." },
  { "P83", OPTION_PDP11_83, "same as ..." },
  { "P84", OPTION_PDP11_84, "same as ..." },
  { "P93", OPTION_PDP11_93, "same as ..." },
  { "P94", OPTION_PDP11_94, "same as ..." },
};

struct
{
  CONST char *title;
  struct options *opts;
  int num;
} all_opts[] =
{
  { "PDP-11 instruction set extentions",
    extension_opts,
    sizeof extension_opts / sizeof extension_opts[0] },
  { "PDP-11 CPU model options",
    cpu_opts,
    sizeof cpu_opts / sizeof cpu_opts[0] },
  { "PDP-11 machine model options",
    model_opts,
    sizeof model_opts / sizeof model_opts[0] },
};

int
parse_match (char *arg, char *pattern)
{
  int yes = 1;

  while (*pattern)
    {
      switch (*pattern++)
	{
	case 'N':
	  if (strncmp (arg, "no-") == 0)
	    {
	      yes = 0;
	      arg += 3;
	    }
	  break;

	case 'K':
	  if (arg[0] == 'k')
	    arg++;
	  break;

	case 'D':
	  if (strncmp (arg, "kd", 2) == 0)
	    arg +=2;
	  break;

	case 'P':
	  if (strncmp (arg, "pdp-11/", 7) == 0)
	    arg += 7;
	  else if (strncmp (arg, "pdp11/", 6) == 0)
	    arg += 6;
	  else if (strncmp (arg, "11/", 3) == 0)
	    arg += 3;
	  break;

	case '_':
	  if (arg[0] == "-")
	    {
	      if (*++arg == 0)
		return 0;
	    }
	  break;

	case '*':
	  return 1;

	default:
	  if (*arg++ != pattern[-1])
	    return 0;
	}
    }

  return arg[0] == 0;
}

int
fprint_opt (stream, pattern)
     FILE *stream;
     CONST char *pattern;
{
  int n;

  while (*pattern)
    {
      switch (*pattern++)
	{
	case 'N':
	  n += fprintf (stream, "(no-)");
	  break;

	case 'K':
	  n += fprintf (stream, "k");
	  break;

	case 'P':
	  n += fprintf (stream "11/");
	  break;

	case 'D':
	case '_':
	case '*':
	  break;

	default:
	  fputc (pattern[-1], stream);
	  n++;
	}
    }

  return n;
}

int
parse_option (char *arg)
{
  int i, j;

  for (i = 0; i < sizeof all_opts / sizeof all_opts[0]; i++)
    {
      for (j = 0; j < all_opts[i].num; j++)
	{
	  if (parse_match (arg, all_opts[i].opts[j].pattern))
	    {
	      set_option (all_opts[i].opts[j].opt);
	      return 1;
	    }
	}
    }

  return 0;
}

static void
fprint_space (stream, n)
     FILE *stream;
     int n;
{
  while (n--)
    fputc (' ', stream);
}

void
md_show_usage (stream)
     FILE *stream;
{
  int i, j, n;

  for (i = 0; i < sizeof all_opts / sizeof all_opts[0]; i++)
    {
      fprintf (stream "\n%s:\n\n", all_opts[i].title);

      for (j = 0; j < all_opts[i].num; j++)
	{
	  fprintf (stream, "-m");
	  n = fprintf_opt (stream, all_opts[i].opts[j].pattern);
	  fprint_space (stream, 22 - n);
	  fprintf (stream, "%s\n", all_opts[i].opts[j].description);
	}
    }
}
*/

void
md_show_usage (stream)
     FILE *stream;
{
  fprintf (stream, "\
\n\
PDP-11 instruction set extentions:\n\
\n\
-m(no-)cis		allow (disallow) commersial instruction set\n\
-m(no-)csm		allow (disallow) CSM instruction\n\
-m(no-)eis		allow (disallow) full extended instruction set\n\
-m(no-)fis		allow (disallow) KEV11 floating-point instructions\n\
-m(no-)fpp		allow (disallow) FP-11 floating-point instructions\n\
-m(no-)fpu		allow (disallow) FP-11 floating-point instructions\n\
-m(no-)limited-eis	allow (disallow) limited extended instruction set\n\
-m(no-)mfpt		allow (disallow) processor type instruction\n\
-m(no-)multiproc	allow (disallow) multiprocessor instructions\n\
-m(no-)mxps		allow (disallow) processor status instructions\n\
-m(no-)spl		allow (disallow) SPL instruction\n\
-m(no-)ucode		allow (disallow) microcode instructions\n\
-mall-extensions	allow all instruction set extensions\n\
			(this is the default)\n\
-mno-extentions		disallow all instruction set extensions\n\
-pic			generate position-indepenent code\n\
\n\
PDP-11 CPU model options:\n\
\n\
-mka11*			KA11 CPU.  base line instruction set only\n\
-mkb11*			KB11 CPU.  enable full EIS and SPL\n\
-mkd11a*		KD11-A CPU.  enable limited EIS\n\
-mkd11b*		KD11-B CPU.  base line instruction set only\n\
-mkd11d*		KD11-D CPU.  base line instruction set only\n\
-mkd11e*		KD11-E CPU.  enable full EIS, MTPS, and MFPS\n\
-mkd11f*		KD11-F CPU.  enable limited EIS, MTPS, and MFPS\n\
-mkd11h*		KD11-H CPU.  enable limited EIS, MTPS, and MFPS\n\
-mkd11q*		KD11-Q CPU.  enable limited EIS, MTPS, and MFPS\n\
-mkd11k*		KD11-K CPU.  enable full EIS, MTPS, MFPS, LDUB, MED,\n\
			XFC, and MFPT\n\
-mkd11z*		KD11-Z CPU.  enable full EIS, MTPS, MFPS, MFPT, SPL,\n\
			and CSM\n\
-mf11*			F11 CPU.  enable full EIS, MFPS, MTPS, and MFPT\n\
-mj11*			J11 CPU.  enable full EIS, MTPS, MFPS, MFPT, SPL,\n\
			CSM, TSTSET, and WRTLCK\n\
-mt11*			T11 CPU.  enable limited EIS, MTPS, and MFPS\n\
\n\
PDP-11 machine model options:\n\
\n\
-m11/03			same as -mkd11f\n\
-m11/04			same as -mkd11d\n\
-m11/05			same as -mkd11b\n\
-m11/10			same as -mkd11b\n\
-m11/15			same as -mka11\n\
-m11/20			same as -mka11\n\
-m11/21			same as -mt11\n\
-m11/23			same as -mf11\n\
-m11/24			same as -mf11\n\
-m11/34			same as -mkd11e\n\
-m11/34a		same as -mkd11e -mfpp\n\
-m11/35			same as -mkd11a\n\
-m11/40			same as -mkd11a\n\
-m11/44			same as -mkd11z\n\
-m11/45			same as -mkb11\n\
-m11/50			same as -mkb11\n\
-m11/53			same as -mj11\n\
-m11/55			same as -mkb11\n\
-m11/60			same as -mkd11k\n\
-m11/70			same as -mkb11\n\
-m11/73			same as -mj11\n\
-m11/83			same as -mj11\n\
-m11/84			same as -mj11\n\
-m11/93			same as -mj11\n\
-m11/94			same as -mj11\n\
");
}

symbolS *
md_undefined_symbol (name)
     char *name ATTRIBUTE_UNUSED;
{
  return 0;
}

valueT
md_section_align (segment, size)
     segT segment ATTRIBUTE_UNUSED;
     valueT size;
{
  return (size + 1) & ~1;
}

long
md_pcrel_from (fixP)
     fixS *fixP;
{
  return fixP->fx_frag->fr_address + fixP->fx_where + fixP->fx_size;
}

/* Translate internal representation of relocation info to BFD target
   format.  */
arelent *
tc_gen_reloc (section, fixp)
     asection *section ATTRIBUTE_UNUSED;
     fixS *fixp;
{
  arelent *reloc;
  bfd_reloc_code_real_type code;

  reloc = (arelent *) xmalloc (sizeof (arelent));

  reloc->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
  *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
  reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;

  /* This is taken account for in md_apply_fix3().  */
  reloc->addend = -symbol_get_bfdsym (fixp->fx_addsy)->section->vma;

  switch (fixp->fx_r_type)
    {
    case BFD_RELOC_16:
      if (fixp->fx_pcrel)
	code = BFD_RELOC_16_PCREL;
      else
	code = BFD_RELOC_16;
      break;

    case BFD_RELOC_16_PCREL:
      code = BFD_RELOC_16_PCREL;
      break;

    default:
      BAD_CASE (fixp->fx_r_type);
      return NULL;
    }

  reloc->howto = bfd_reloc_type_lookup (stdoutput, code);

  if (reloc->howto == NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
		    "Can not represent %s relocation in this object file format",
		    bfd_get_reloc_code_name (code));
      return NULL;
    }

  return reloc;
}

void
pseudo_bss (c)
     int c ATTRIBUTE_UNUSED;
{
  int temp;

  temp = get_absolute_expression ();
  subseg_set (bss_section, temp);
  demand_empty_rest_of_line ();
}

void
pseudo_even (c)
     int c ATTRIBUTE_UNUSED;
{
  int alignment = 1; /* 2^1 */
  frag_align (alignment, 0, 1);
  record_alignment (now_seg, alignment);
}

/* end of tc-pdp11.c */
