tc-i860.c

基于4个mips核的noc设计

  t = atof_ieee (input_line_pointer, type, words);
  if (t)
    input_line_pointer = t;
  *sizeP = prec * sizeof (LITTLENUM_TYPE);
  for (wordP = words; prec--;)
    {
      md_number_to_chars (litP, (long) (*wordP++), sizeof (LITTLENUM_TYPE));
      litP += sizeof (LITTLENUM_TYPE);
    }
  return 0;
}

/* Write out in current endian mode.  */
void
md_number_to_chars (buf, val, n)
     char *buf;
     valueT val;
     int n;
{
  if (target_big_endian)
    number_to_chars_bigendian (buf, val, n);
  else
    number_to_chars_littleendian (buf, val, n);
}

/* This should never be called for i860.  */
void
md_number_to_disp (buf, val, n)
     char *buf ATTRIBUTE_UNUSED;
     long val ATTRIBUTE_UNUSED;
     int n ATTRIBUTE_UNUSED;
{
  as_fatal (_("md_number_to_disp\n"));
}

/* This should never be called for i860.  */
void
md_number_to_field (buf, val, fix)
     char *buf ATTRIBUTE_UNUSED;
     long val ATTRIBUTE_UNUSED;
     void *fix ATTRIBUTE_UNUSED;
{
  as_fatal (_("i860_number_to_field\n"));
}

/* This should never be called for i860.  */
int
md_estimate_size_before_relax (fragP, segtype)
     register fragS *fragP ATTRIBUTE_UNUSED;
     segT segtype ATTRIBUTE_UNUSED;
{
  as_fatal (_("i860_estimate_size_before_relax\n"));
}

#ifdef DEBUG_I860
static void
print_insn (insn)
     struct i860_it *insn;
{
  if (insn->error)
    fprintf (stderr, "ERROR: %s\n", insn->error);

  fprintf (stderr, "opcode = 0x%08lx\t", insn->opcode);
  fprintf (stderr, "expand = 0x%x\t", insn->expand);
  fprintf (stderr, "reloc = %s\t\n",
	   bfd_get_reloc_code_name (insn->reloc));
  fprintf (stderr, "exp =  {\n");
  fprintf (stderr, "\t\tX_add_symbol = %s\n",
	   insn->exp.X_add_symbol ?
	   (S_GET_NAME (insn->exp.X_add_symbol) ?
	    S_GET_NAME (insn->exp.X_add_symbol) : "???") : "0");
  fprintf (stderr, "\t\tX_op_symbol = %s\n",
	   insn->exp.X_op_symbol ?
	   (S_GET_NAME (insn->exp.X_op_symbol) ?
	    S_GET_NAME (insn->exp.X_op_symbol) : "???") : "0");
  fprintf (stderr, "\t\tX_add_number = %lx\n",
	   insn->exp.X_add_number);
  fprintf (stderr, "}\n");
}
#endif /* DEBUG_I860 */


#ifdef OBJ_ELF
CONST char *md_shortopts = "VQ:";
#else
CONST char *md_shortopts = "";
#endif

#define OPTION_EB		(OPTION_MD_BASE + 0)
#define OPTION_EL		(OPTION_MD_BASE + 1)
#define OPTION_WARN_EXPAND	(OPTION_MD_BASE + 2)

struct option md_longopts[] = {
  { "EB",	    no_argument, NULL, OPTION_EB },
  { "EL",	    no_argument, NULL, OPTION_EL },
  { "mwarn-expand", no_argument, NULL, OPTION_WARN_EXPAND },
  { NULL,	    no_argument, NULL, 0 }
};
size_t md_longopts_size = sizeof (md_longopts);

int
md_parse_option (c, arg)
     int c;
     char *arg ATTRIBUTE_UNUSED;
{
  switch (c)
    {
    case OPTION_EB:
      target_big_endian = 1;
      break;

    case OPTION_EL:
      target_big_endian = 0;
      break;

    case OPTION_WARN_EXPAND:
      target_warn_expand = 1;
      break;

#ifdef OBJ_ELF
    /* SVR4 argument compatibility (-V): print version ID.  */
    case 'V':
      print_version_id ();
      break;

    /* SVR4 argument compatibility (-Qy, -Qn): controls whether
       a .comment section should be emitted or not (ignored).  */
    case 'Q':
      break;
#endif

    default:
      return 0;
    }

  return 1;
}

void
md_show_usage (stream)
     FILE *stream;
{
  fprintf (stream, _("\
  -EL			  generate code for little endian mode (default)\n\
  -EB			  generate code for big endian mode\n\
  -mwarn-expand		  warn if pseudo operations are expanded\n"));
#ifdef OBJ_ELF
  /* SVR4 compatibility flags.  */
  fprintf (stream, _("\
  -V			  print assembler version number\n\
  -Qy, -Qn		  ignored\n"));
#endif
}


/* We have no need to default values of symbols.  */
symbolS *
md_undefined_symbol (name)
     char *name ATTRIBUTE_UNUSED;
{
  return 0;
}

/* The i860 denotes auto-increment with '++'.  */
void
md_operand (exp)
     expressionS *exp;
{
  char *s;

  for (s = input_line_pointer; *s; s++)
    {
      if (s[0] == '+' && s[1] == '+')
	{
	  input_line_pointer += 2;
	  exp->X_op = O_register;
	  break;
	}
    }
}

/* Round up a section size to the appropriate boundary.  */
valueT
md_section_align (segment, size)
     segT segment ATTRIBUTE_UNUSED;
     valueT size ATTRIBUTE_UNUSED;
{
  /* Byte alignment is fine.  */
  return size;
}

/* On the i860, a PC-relative offset is relative to the address of the
   of the offset plus its size.  */
long
md_pcrel_from (fixP)
     fixS *fixP;
{
  return fixP->fx_size + fixP->fx_where + fixP->fx_frag->fr_address;
}

/* Determine the relocation needed for non PC-relative 16-bit immediates.
   Also adjust the given immediate as necessary.  Finally, check that
   all constraints (such as alignment) are satisfied.   */
static bfd_reloc_code_real_type
obtain_reloc_for_imm16 (fix, val)
     fixS *fix;
     long *val;
{
  valueT fup = fix->fx_addnumber;
  bfd_reloc_code_real_type reloc;

  if (fix->fx_pcrel)
    abort ();

  /* Check alignment restrictions.  */
  if ((fup & OP_ALIGN2) && (*val & 0x1))
    as_bad_where (fix->fx_file, fix->fx_line,
		  _("This immediate requires 0 MOD 2 alignment"));
  else if ((fup & OP_ALIGN4) && (*val & 0x3))
    as_bad_where (fix->fx_file, fix->fx_line,
		  _("This immediate requires 0 MOD 4 alignment"));
  else if ((fup & OP_ALIGN8) && (*val & 0x7))
    as_bad_where (fix->fx_file, fix->fx_line,
		  _("This immediate requires 0 MOD 8 alignment"));
  else if ((fup & OP_ALIGN16) && (*val & 0xf))
    as_bad_where (fix->fx_file, fix->fx_line,
		  _("This immediate requires 0 MOD 16 alignment"));

  if (fup & OP_SEL_HA)
    {
      *val = (*val >> 16) + (*val & 0x8000 ? 1 : 0);
      reloc = BFD_RELOC_860_HIGHADJ;
    }
  else if (fup & OP_SEL_H)
    {
      *val >>= 16;
      reloc = BFD_RELOC_860_HIGH;
    }
  else if (fup & OP_SEL_L)
    {
      int num_encode;
      if (fup & OP_IMM_SPLIT16)
	{
	  if (fup & OP_ENCODE1)
	    {
	      num_encode = 1;
	      reloc = BFD_RELOC_860_SPLIT1;
	    }
	  else if (fup & OP_ENCODE2)
	    {
	      num_encode = 2;
	      reloc = BFD_RELOC_860_SPLIT2;
	    }
	  else
	    {
	      num_encode = 0;
	      reloc = BFD_RELOC_860_SPLIT0;
	    }
	}
      else
	{
	  if (fup & OP_ENCODE1)
	    {
	      num_encode = 1;
	      reloc = BFD_RELOC_860_LOW1;
	    }
	  else if (fup & OP_ENCODE2)
	    {
	      num_encode = 2;
	      reloc = BFD_RELOC_860_LOW2;
	    }
	  else if (fup & OP_ENCODE3)
	    {
	      num_encode = 3;
	      reloc = BFD_RELOC_860_LOW3;
	    }
	  else
	    {
	      num_encode = 0;
	      reloc = BFD_RELOC_860_LOW0;
	    }
	}

      /* Preserve size encode bits.  */
      *val &= ~((1 << num_encode) - 1);
    }
  else
    {
      /* No selector.  What reloc do we generate (???)?  */
      reloc = BFD_RELOC_32;
    }

  return reloc;
}

/* Attempt to simplify or eliminate a fixup. To indicate that a fixup
   has been eliminated, set fix->fx_done. If fix->fx_addsy is non-NULL,
   we will have to generate a reloc entry.  */
int
md_apply_fix3 (fix, valuep, seg)
     fixS *fix;
     valueT *valuep;
     segT seg ATTRIBUTE_UNUSED;
{

  char *buf;
  long val = (long) (*valuep);
  unsigned long insn;
  valueT fup;

  buf = fix->fx_frag->fr_literal + fix->fx_where;

  /* Recall that earlier we stored the opcode little-endian.  */
  insn = bfd_getl32 (buf);

  /* We stored a fix-up in this oddly-named scratch field.  */
  fup = fix->fx_addnumber;

  /* Determine the necessary relocations as well as inserting an
     immediate into the instruction.   */
  if (fup == OP_IMM_U5)
    {
      if (val & ~0x1f)
	as_bad_where (fix->fx_file, fix->fx_line,
		      _("5-bit immediate too large"));
      if (fix->fx_addsy)
	as_bad_where (fix->fx_file, fix->fx_line,
		      _("5-bit field must be absolute"));

      insn |= (val & 0x1f) << 11;
      bfd_putl32 (insn, buf);
      fix->fx_r_type = BFD_RELOC_NONE;
      fix->fx_done = 1;
    }
  else if (fup & OP_IMM_S16)
    {
      fix->fx_r_type = obtain_reloc_for_imm16 (fix, &val);

      /* Insert the immediate.  */
      if (fix->fx_addsy)
	fix->fx_done = 0;
      else
	{
	  insn |= val & 0xffff;
	  bfd_putl32 (insn, buf);
	  fix->fx_r_type = BFD_RELOC_NONE;
	  fix->fx_done = 1;
	}
    }
  else if (fup & OP_IMM_U16)
    {
      abort ();
    }
  else if (fup & OP_IMM_SPLIT16)
    {
      fix->fx_r_type = obtain_reloc_for_imm16 (fix, &val);

      /* Insert the immediate.  */
      if (fix->fx_addsy)
	fix->fx_done = 0;
      else
	{
	  insn |= val & 0x7ff;
	  insn |= (val & 0xf800) << 5;
	  bfd_putl32 (insn, buf);
	  fix->fx_r_type = BFD_RELOC_NONE;
	  fix->fx_done = 1;
	}
    }
  else if (fup & OP_IMM_BR16)
    {
      if (val & 0x3)
	as_bad_where (fix->fx_file, fix->fx_line,
		      _("A branch offset requires 0 MOD 4 alignment"));

      val = val >> 2;

      /* Insert the immediate.  */
      if (fix->fx_addsy)
	{
	  fix->fx_done = 0;
	  fix->fx_r_type = BFD_RELOC_860_PC16;
	}
      else
	{
	  insn |= (val & 0x7ff);
	  insn |= ((val & 0xf800) << 5);
	  bfd_putl32 (insn, buf);
	  fix->fx_r_type = BFD_RELOC_NONE;
	  fix->fx_done = 1;
	}
    }
  else if (fup & OP_IMM_BR26)
    {
      if (val & 0x3)
	as_bad_where (fix->fx_file, fix->fx_line,
		      _("A branch offset requires 0 MOD 4 alignment"));

      val >>= 2;

      /* Insert the immediate.  */
      if (fix->fx_addsy)
	{
	  fix->fx_r_type = BFD_RELOC_860_PC26;
	  fix->fx_done = 0;
	}
      else
	{
	  insn |= (val & 0x3ffffff);
	  bfd_putl32 (insn, buf);
	  fix->fx_r_type = BFD_RELOC_NONE;
	  fix->fx_done = 1;
	}
    }
  else if (fup != OP_NONE)
    {
      as_bad_where (fix->fx_file, fix->fx_line,
		    _("Unrecognized fix-up (0x%08x)"), fup);
      abort ();
    }
  else
    {
      /* I believe only fix-ups such as ".long .ep.main-main+0xc8000000"
 	 reach here (???).  */
      if (fix->fx_addsy)
	{
	  fix->fx_r_type = BFD_RELOC_32;
	  fix->fx_done = 0;
	}
      else
	{
	  insn |= (val & 0xffffffff);
	  bfd_putl32 (insn, buf);
	  fix->fx_r_type = BFD_RELOC_NONE;
	  fix->fx_done = 1;
	}
    }

  /* Return value ignored.  */
  return 0;
}

/* Generate a machine dependent reloc from a fixup.  */
arelent*
tc_gen_reloc (section, fixp)
     asection *section ATTRIBUTE_UNUSED;
     fixS *fixp;
{
  arelent *reloc;

  reloc = xmalloc (sizeof (*reloc));
  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->addend = fixp->fx_offset;
  reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);

  if (! reloc->howto)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
                    "Cannot represent %s relocation in object file",
                    bfd_get_reloc_code_name (fixp->fx_r_type));
    }
  return reloc;
}