tc-avr.c

基于4个mips核的noc设计

    {
      /* Fetch the instruction, insert the fully resolved operand
	 value, and stuff the instruction back again.  */
      where = fixp->fx_frag->fr_literal + fixp->fx_where;
      insn = bfd_getl16 (where);

      switch (fixp->fx_r_type)
	{
	case BFD_RELOC_AVR_7_PCREL:
	  if (value & 1)
	    as_bad_where (fixp->fx_file, fixp->fx_line,
			  _("odd address operand: %ld"), value);

	  /* Instruction addresses are always right-shifted by 1.  */
	  value >>= 1;
	  --value;			/* Correct PC.  */

	  if (value < -64 || value > 63)
	    as_bad_where (fixp->fx_file, fixp->fx_line,
			  _("operand out of range: %ld"), value);
	  value = (value << 3) & 0x3f8;
	  bfd_putl16 ((bfd_vma) (value | insn), where);
	  break;

	case BFD_RELOC_AVR_13_PCREL:
	  if (value & 1)
	    as_bad_where (fixp->fx_file, fixp->fx_line,
			  _("odd address operand: %ld"), value);

	  /* Instruction addresses are always right-shifted by 1.  */
	  value >>= 1;
	  --value;			/* Correct PC.  */

	  if (value < -2048 || value > 2047)
	    {
	      /* No wrap for devices with >8K of program memory.  */
	      if ((avr_mcu->isa & AVR_ISA_MEGA) || avr_opt.no_wrap)
		as_bad_where (fixp->fx_file, fixp->fx_line,
			      _("operand out of range: %ld"), value);
	    }

	  value &= 0xfff;
	  bfd_putl16 ((bfd_vma) (value | insn), where);
	  break;

	case BFD_RELOC_32:
	  bfd_putl16 ((bfd_vma) value, where);
	  break;

	case BFD_RELOC_16:
	  bfd_putl16 ((bfd_vma) value, where);
	  break;

	case BFD_RELOC_AVR_16_PM:
	  bfd_putl16 ((bfd_vma) (value >> 1), where);
	  break;

	case BFD_RELOC_AVR_LO8_LDI:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value), where);
	  break;

	case -BFD_RELOC_AVR_LO8_LDI:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 16), where);
	  break;

	case BFD_RELOC_AVR_HI8_LDI:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 8), where);
	  break;

	case -BFD_RELOC_AVR_HI8_LDI:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 24), where);
	  break;

	case BFD_RELOC_AVR_HH8_LDI:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 16), where);
	  break;

	case BFD_RELOC_AVR_LO8_LDI_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value), where);
	  break;

	case -BFD_RELOC_AVR_LO8_LDI_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 16), where);
	  break;

	case BFD_RELOC_AVR_HI8_LDI_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 8), where);
	  break;

	case -BFD_RELOC_AVR_HI8_LDI_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 24), where);
	  break;

	case BFD_RELOC_AVR_HH8_LDI_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 16), where);
	  break;

	case BFD_RELOC_AVR_LO8_LDI_PM:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 1), where);
	  break;

	case BFD_RELOC_AVR_HI8_LDI_PM:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 9), where);
	  break;

	case BFD_RELOC_AVR_HH8_LDI_PM:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 17), where);
	  break;

	case BFD_RELOC_AVR_LO8_LDI_PM_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 1), where);
	  break;

	case BFD_RELOC_AVR_HI8_LDI_PM_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 9), where);
	  break;

	case BFD_RELOC_AVR_HH8_LDI_PM_NEG:
	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 17), where);
	  break;

	case BFD_RELOC_AVR_CALL:
	  {
	    unsigned long x;

	    x = bfd_getl16 (where);
	    if (value & 1)
	      as_bad_where (fixp->fx_file, fixp->fx_line,
			    _("odd address operand: %ld"), value);
	    value >>= 1;
	    x |= ((value & 0x10000) | ((value << 3) & 0x1f00000)) >> 16;
	    bfd_putl16 ((bfd_vma) x, where);
	    bfd_putl16 ((bfd_vma) (value & 0xffff), where + 2);
	  }
	  break;

	default:
	  as_fatal (_("line %d: unknown relocation type: 0x%x"),
		    fixp->fx_line, fixp->fx_r_type);
	  break;
	}
    }
  else
    {
      switch (fixp->fx_r_type)
	{
	case -BFD_RELOC_AVR_HI8_LDI_NEG:
	case -BFD_RELOC_AVR_HI8_LDI:
	case -BFD_RELOC_AVR_LO8_LDI_NEG:
	case -BFD_RELOC_AVR_LO8_LDI:
	  as_bad_where (fixp->fx_file, fixp->fx_line,
			_("only constant expression allowed"));
	  fixp->fx_done = 1;
	  break;
	default:
	  break;
	}
      fixp->fx_addnumber = value;
    }
  return 0;
}

/* A `BFD_ASSEMBLER' GAS will call this to generate a reloc.  GAS
   will pass the resulting reloc to `bfd_install_relocation'.  This
   currently works poorly, as `bfd_install_relocation' often does the
   wrong thing, and instances of `tc_gen_reloc' have been written to
   work around the problems, which in turns makes it difficult to fix
   `bfd_install_relocation'.  */

/* If while processing a fixup, a reloc really needs to be created
   then it is done here.  */

arelent *
tc_gen_reloc (seg, fixp)
     asection *seg ATTRIBUTE_UNUSED;
     fixS *fixp;
{
  arelent *reloc;

  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;
  reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);
  if (reloc->howto == (reloc_howto_type *) NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
		    _("reloc %d not supported by object file format"),
		    (int) fixp->fx_r_type);
      return NULL;
    }

  if (fixp->fx_r_type == BFD_RELOC_VTABLE_INHERIT
      || fixp->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
    reloc->address = fixp->fx_offset;

  reloc->addend = fixp->fx_offset;

  return reloc;
}

void
md_assemble (str)
     char *str;
{
  struct avr_opcodes_s *opcode;
  char op[11];

  str = skip_space (extract_word (str, op, sizeof (op)));

  if (!op[0])
    as_bad (_("can't find opcode "));

  opcode = (struct avr_opcodes_s *) hash_find (avr_hash, op);

  if (opcode == NULL)
    {
      as_bad (_("unknown opcode `%s'"), op);
      return;
    }

  /* Special case for opcodes with optional operands (lpm, elpm) -
     version with operands exists in avr_opcodes[] in the next entry.  */

  if (*str && *opcode->constraints == '?')
    ++opcode;

  if (!avr_opt.all_opcodes && (opcode->isa & avr_mcu->isa) != opcode->isa)
    as_bad (_("illegal opcode %s for mcu %s"), opcode->name, avr_mcu->name);

  /* We used to set input_line_pointer to the result of get_operands,
     but that is wrong.  Our caller assumes we don't change it.  */
  {
    char *t = input_line_pointer;
    avr_operands (opcode, &str);
    if (*skip_space (str))
      as_bad (_("garbage at end of line"));
    input_line_pointer = t;
  }
}

/* Parse ordinary expression.  */

static char *
parse_exp (s, op)
     char *s;
     expressionS *op;
{
  input_line_pointer = s;
  expression (op);
  if (op->X_op == O_absent)
    as_bad (_("missing operand"));
  return input_line_pointer;
}

/* Parse special expressions (needed for LDI command):
   xx8 (address)
   xx8 (-address)
   pm_xx8 (address)
   pm_xx8 (-address)
   where xx is: hh, hi, lo.  */

static bfd_reloc_code_real_type
avr_ldi_expression (exp)
     expressionS *exp;
{
  char *str = input_line_pointer;
  char *tmp;
  char op[8];
  int mod;
  tmp = str;

  str = extract_word (str, op, sizeof (op));

  if (op[0])
    {
      mod = (int) hash_find (avr_mod_hash, op);

      if (mod)
	{
	  int closes = 0;

	  mod -= 10;
	  str = skip_space (str);

	  if (*str == '(')
	    {
	      int neg_p = 0;

	      ++str;

	      if (strncmp ("pm(", str, 3) == 0
		  || strncmp ("-(pm(", str, 5) == 0)
		{
		  if (HAVE_PM_P (mod))
		    {
		      ++mod;
		      ++closes;
		    }
		  else
		    as_bad (_("illegal expression"));

		  if (*str == '-')
		    {
		      neg_p = 1;
		      ++closes;
		      str += 5;
		    }
		  else
		    str += 3;
		}

	      if (*str == '-' && *(str + 1) == '(')
		{
		  neg_p ^= 1;
		  ++closes;
		  str += 2;
		}

	      input_line_pointer = str;
	      expression (exp);

	      do
		{
		  if (*input_line_pointer != ')')
		    {
		      as_bad (_("`)' required"));
		      break;
		    }
		  input_line_pointer++;
		}
	      while (closes--);

	      return neg_p ? EXP_MOD_NEG_RELOC (mod) : EXP_MOD_RELOC (mod);
	    }
	}
    }

  input_line_pointer = tmp;
  expression (exp);

  /* Warn about expressions that fail to use lo8 ().  */
  if (exp->X_op == O_constant)
    {
      int x = exp->X_add_number;
      if (x < -255 || x > 255)
	as_warn (_("constant out of 8-bit range: %d"), x);
    }
  else
    as_warn (_("expression possibly out of 8-bit range"));

  return BFD_RELOC_AVR_LO8_LDI;
}

/* Flag to pass `pm' mode between `avr_parse_cons_expression' and
   `avr_cons_fix_new'.  */
static int exp_mod_pm = 0;

/* Parse special CONS expression: pm (expression)
   which is used for addressing to a program memory.
   Relocation: BFD_RELOC_AVR_16_PM.  */

void
avr_parse_cons_expression (exp, nbytes)
     expressionS *exp;
     int nbytes;
{
  char *tmp;

  exp_mod_pm = 0;

  tmp = input_line_pointer = skip_space (input_line_pointer);

  if (nbytes == 2)
    {
      char *pm_name = "pm";
      int len = strlen (pm_name);

      if (strncasecmp (input_line_pointer, pm_name, len) == 0)
	{
	  input_line_pointer = skip_space (input_line_pointer + len);

	  if (*input_line_pointer == '(')
	    {
	      input_line_pointer = skip_space (input_line_pointer + 1);
	      exp_mod_pm = 1;
	      expression (exp);

	      if (*input_line_pointer == ')')
		++input_line_pointer;
	      else
		{
		  as_bad (_("`)' required"));
		  exp_mod_pm = 0;
		}

	      return;
	    }

	  input_line_pointer = tmp;
	}
    }

  expression (exp);
}

void
avr_cons_fix_new (frag, where, nbytes, exp)
     fragS *frag;
     int where;
     int nbytes;
     expressionS *exp;
{
  if (exp_mod_pm == 0)
    {
      if (nbytes == 2)
	fix_new_exp (frag, where, nbytes, exp, false, BFD_RELOC_16);
      else if (nbytes == 4)
	fix_new_exp (frag, where, nbytes, exp, false, BFD_RELOC_32);
      else
	as_bad (_("illegal %srelocation size: %d"), "", nbytes);
    }
  else
    {
      if (nbytes == 2)
	fix_new_exp (frag, where, nbytes, exp, false, BFD_RELOC_AVR_16_PM);
      else
	as_bad (_("illegal %srelocation size: %d"), "`pm' ", nbytes);
      exp_mod_pm = 0;
    }
}