tc-d30v.c

基于4个mips核的noc设计

		  /* Turn an expression into a symbol for later resolution.  */
		  if (X_op != O_absent && X_op != O_constant
		      && X_op != O_symbol && X_op != O_register
		      && X_op != O_big)
		    {
		      symbolS *sym = make_expr_symbol (&myops[j]);
		      myops[j].X_op = X_op = O_symbol;
		      myops[j].X_add_symbol = sym;
		      myops[j].X_add_number = num = 0;
		    }

		  if (fm->form >= LONG)
		    {
		      /* If we're testing for a LONG format, either fits.  */
		      if (X_op != O_constant && X_op != O_symbol)
			match = 0;
		    }
		  else if (fm->form < LONG
			   && ((fsize == FORCE_SHORT && X_op == O_symbol)
			       || (fm->form == SHORT_D2 && j == 0)))
		    match = 1;

		  /* This is the tricky part.  Will the constant or symbol
		     fit into the space in the current format?  */
		  else if (X_op == O_constant)
		    {
		      if (check_range (num, bits, flags))
			match = 0;
		    }
		  else if (X_op == O_symbol
			   && S_IS_DEFINED (myops[j].X_add_symbol)
			   && S_GET_SEGMENT (myops[j].X_add_symbol) == now_seg
			   && opcode->reloc_flag == RELOC_PCREL)
		    {
		      /* If the symbol is defined, see if the value will fit
			 into the form we're considering.  */
		      fragS *f;
		      long value;

		      /* Calculate the current address by running through the
			 previous frags and adding our current offset.  */
		      value = 0;
		      for (f = frchain_now->frch_root; f; f = f->fr_next)
			value += f->fr_fix + f->fr_offset;
		      value = (S_GET_VALUE (myops[j].X_add_symbol) - value
			       - (obstack_next_free (&frchain_now->frch_obstack)
				  - frag_now->fr_literal));
		      if (check_range (value, bits, flags))
			match = 0;
		    }
		  else
		    match = 0;
		}
	    }
#if 0
	  printf ("through the loop: match=%d\n", match);
#endif
	  /* We're only done if the operands matched so far AND there
	     are no more to check.  */
	  if (match && myops[j].X_op == 0)
	    {
	      /* Final check - issue a warning if an odd numbered register
		 is used as the first register in an instruction that reads
		 or writes 2 registers.  */

	      for (j = 0; fm->operands[j]; j++)
		if (myops[j].X_op == O_register
		    && (myops[j].X_add_number & 1)
		    && (d30v_operand_table[fm->operands[j]].flags & OPERAND_2REG))
		  as_warn (_("Odd numbered register used as target of multi-register instruction"));

	      return fm;
	    }
	  fm = (struct d30v_format *) &d30v_format_table[++k];
	}
#if 0
      printf ("trying another format: i=%d\n", i);
#endif
    }
  return NULL;
}

/* 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;
     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;
    }
  reloc->addend = fixp->fx_addnumber;
  return reloc;
}

int
md_estimate_size_before_relax (fragp, seg)
     fragS *fragp;
     asection *seg;
{
  abort ();
  return 0;
}

long
md_pcrel_from_section (fixp, sec)
     fixS *fixp;
     segT sec;
{
  if (fixp->fx_addsy != (symbolS *) NULL
      && (!S_IS_DEFINED (fixp->fx_addsy)
	  || (S_GET_SEGMENT (fixp->fx_addsy) != sec)))
    return 0;
  return fixp->fx_frag->fr_address + fixp->fx_where;
}

int
md_apply_fix3 (fixp, valuep, seg)
     fixS *fixp;
     valueT *valuep;
     segT seg;
{
  char *where;
  unsigned long insn, insn2;
  long value;

  if (fixp->fx_addsy == (symbolS *) NULL)
    {
      value = *valuep;
      fixp->fx_done = 1;
    }
  else if (fixp->fx_pcrel)
    value = *valuep;
  else
    {
      value = fixp->fx_offset;

      if (fixp->fx_subsy != (symbolS *) NULL)
	{
	  if (S_GET_SEGMENT (fixp->fx_subsy) == absolute_section)
	    value -= S_GET_VALUE (fixp->fx_subsy);
	  else
	    {
	      /* We don't actually support subtracting a symbol.  */
	      as_bad_where (fixp->fx_file, fixp->fx_line,
			    _("expression too complex"));
	    }
	}
    }

  /* 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_getb32 ((unsigned char *) where);

  switch (fixp->fx_r_type)
    {
    case BFD_RELOC_8:  /* Check for a bad .byte directive.  */
      if (fixp->fx_addsy != NULL)
	as_bad (_("line %d: unable to place address of symbol '%s' into a byte"),
		fixp->fx_line, S_GET_NAME (fixp->fx_addsy));
      else if (((unsigned)value) > 0xff)
	as_bad (_("line %d: unable to place value %x into a byte"),
		fixp->fx_line, value);
      else
	*(unsigned char *) where = value;
      break;

    case BFD_RELOC_16:  /* Check for a bad .short directive.  */
      if (fixp->fx_addsy != NULL)
	as_bad (_("line %d: unable to place address of symbol '%s' into a short"),
		fixp->fx_line, S_GET_NAME (fixp->fx_addsy));
      else if (((unsigned)value) > 0xffff)
	as_bad (_("line %d: unable to place value %x into a short"),
		fixp->fx_line, value);
      else
	bfd_putb16 ((bfd_vma) value, (unsigned char *) where);
      break;

    case BFD_RELOC_64:  /* Check for a bad .quad directive.  */
      if (fixp->fx_addsy != NULL)
	as_bad (_("line %d: unable to place address of symbol '%s' into a quad"),
		fixp->fx_line, S_GET_NAME (fixp->fx_addsy));
      else
	{
	  bfd_putb32 ((bfd_vma) value, (unsigned char *) where);
	  bfd_putb32 (0, ((unsigned char *) where) + 4);
	}
      break;

    case BFD_RELOC_D30V_6:
      check_size (value, 6, fixp->fx_file, fixp->fx_line);
      insn |= value & 0x3F;
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      break;

    case BFD_RELOC_D30V_9_PCREL:
      if (fixp->fx_where & 0x7)
	{
	  if (fixp->fx_done)
	    value += 4;
	  else
	    fixp->fx_r_type = BFD_RELOC_D30V_9_PCREL_R;
	}
      check_size (value, 9, fixp->fx_file, fixp->fx_line);
      insn |= ((value >> 3) & 0x3F) << 12;
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      break;

    case BFD_RELOC_D30V_15:
      check_size (value, 15, fixp->fx_file, fixp->fx_line);
      insn |= (value >> 3) & 0xFFF;
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      break;

    case BFD_RELOC_D30V_15_PCREL:
      if (fixp->fx_where & 0x7)
	{
	  if (fixp->fx_done)
	    value += 4;
	  else
	    fixp->fx_r_type = BFD_RELOC_D30V_15_PCREL_R;
	}
      check_size (value, 15, fixp->fx_file, fixp->fx_line);
      insn |= (value >> 3) & 0xFFF;
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      break;

    case BFD_RELOC_D30V_21:
      check_size (value, 21, fixp->fx_file, fixp->fx_line);
      insn |= (value >> 3) & 0x3FFFF;
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      break;

    case BFD_RELOC_D30V_21_PCREL:
      if (fixp->fx_where & 0x7)
	{
	  if (fixp->fx_done)
	    value += 4;
	  else
	    fixp->fx_r_type = BFD_RELOC_D30V_21_PCREL_R;
	}
      check_size (value, 21, fixp->fx_file, fixp->fx_line);
      insn |= (value >> 3) & 0x3FFFF;
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      break;

    case BFD_RELOC_D30V_32:
      insn2 = bfd_getb32 ((unsigned char *) where + 4);
      insn |= (value >> 26) & 0x3F;		/* Top 6 bits.  */
      insn2 |= ((value & 0x03FC0000) << 2);	/* Next 8 bits.  */
      insn2 |= value & 0x0003FFFF;		/* Bottom 18 bits.  */
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      bfd_putb32 ((bfd_vma) insn2, (unsigned char *) where + 4);
      break;

    case BFD_RELOC_D30V_32_PCREL:
      insn2 = bfd_getb32 ((unsigned char *) where + 4);
      insn |= (value >> 26) & 0x3F;		/* Top 6 bits.  */
      insn2 |= ((value & 0x03FC0000) << 2);	/* Next 8 bits.  */
      insn2 |= value & 0x0003FFFF;		/* Bottom 18 bits.  */
      bfd_putb32 ((bfd_vma) insn, (unsigned char *) where);
      bfd_putb32 ((bfd_vma) insn2, (unsigned char *) where + 4);
      break;

    case BFD_RELOC_32:
      bfd_putb32 ((bfd_vma) value, (unsigned char *) where);
      break;

    default:
      as_bad (_("line %d: unknown relocation type: 0x%x"),
	      fixp->fx_line, fixp->fx_r_type);
    }

  return 0;
}

/* Called after the assembler has finished parsing the input file or
   after a label is defined.  Because the D30V assembler sometimes
   saves short instructions to see if it can package them with the
   next instruction, there may be a short instruction that still needs
   written.  */

int
d30v_cleanup (use_sequential)
     int use_sequential;
{
  segT seg;
  subsegT subseg;

  if (prev_insn != -1)
    {
      seg = now_seg;
      subseg = now_subseg;
      subseg_set (prev_seg, prev_subseg);
      write_1_short (&prev_opcode, (long) prev_insn, fixups->next,
		     use_sequential);
      subseg_set (seg, subseg);
      prev_insn = -1;
      if (use_sequential)
	prev_mul32_p = false;
    }

  return 1;
}

static void
d30v_number_to_chars (buf, value, n)
     char *buf;			/* Return 'nbytes' of chars here.  */
     long long value;		/* The value of the bits.  */
     int n;			/* Number of bytes in the output.  */
{
  while (n--)
    {
      buf[n] = value & 0xff;
      value >>= 8;
    }
}

/* This function is called at the start of every line.  It checks to
   see if the first character is a '.', which indicates the start of a
   pseudo-op.  If it is, then write out any unwritten instructions.  */

void
d30v_start_line ()
{
  char *c = input_line_pointer;

  while (isspace (*c))
    c++;

  if (*c == '.')
    d30v_cleanup (false);
}

static void
check_size (value, bits, file, line)
     long value;
     int bits;
     char *file;
     int line;
{
  int tmp, max;

  if (value < 0)
    tmp = ~value;
  else
    tmp = value;

  max = (1 << (bits - 1)) - 1;

  if (tmp > max)
    as_bad_where (file, line, _("value too large to fit in %d bits"), bits);

  return;
}

/* d30v_frob_label() is called when after a label is recognized.  */

void
d30v_frob_label (lab)
     symbolS *lab;
{
  /* Emit any pending instructions.  */
  d30v_cleanup (false);

  /* Update the label's address with the current output pointer.  */
  symbol_set_frag (lab, frag_now);
  S_SET_VALUE (lab, (valueT) frag_now_fix ());

  /* Record this label for future adjustment after we find out what
     kind of data it references, and the required alignment therewith.  */
  d30v_last_label = lab;
}

/* Hook into cons for capturing alignment changes.  */

void
d30v_cons_align (size)
     int size;
{
  int log_size;

  log_size = 0;
  while ((size >>= 1) != 0)
    ++log_size;

  if (d30v_current_align < log_size)
    d30v_align (log_size, (char *) NULL, NULL);
  else if (d30v_current_align > log_size)
    d30v_current_align = log_size;
  d30v_last_label = NULL;
}

/* Called internally to handle all alignment needs.  This takes care
   of eliding calls to frag_align if'n the cached current alignment
   says we've already got it, as well as taking care of the auto-aligning
   labels wrt code.  */

static void
d30v_align (n, pfill, label)
     int n;
     char *pfill;
     symbolS *label;
{
  /* The front end is prone to changing segments out from under us
     temporarily when -g is in effect.  */
  int switched_seg_p = (d30v_current_align_seg != now_seg);

  /* Do not assume that if 'd30v_current_align >= n' and
     '! switched_seg_p' that it is safe to avoid performing
     this alignement request.  The alignment of the current frag
     can be changed under our feet, for example by a .ascii
     directive in the source code.  cf testsuite/gas/d30v/reloc.s  */
  d30v_cleanup (false);

  if (pfill == NULL)
    {
      if (n > 2
	  && (bfd_get_section_flags (stdoutput, now_seg) & SEC_CODE) != 0)
	{
	  static char const nop[4] = { 0x00, 0xf0, 0x00, 0x00 };

	  /* First, make sure we're on a four-byte boundary, in case
	     someone has been putting .byte values the text section.  */
	  if (d30v_current_align < 2 || switched_seg_p)
	    frag_align (2, 0, 0);
	  frag_align_pattern (n, nop, sizeof nop, 0);
	}
      else
	frag_align (n, 0, 0);
    }
  else
    frag_align (n, *pfill, 0);

  if (!switched_seg_p)
    d30v_current_align = n;

  if (label != NULL)
    {
      symbolS     *sym;
      int          label_seen = false;
      struct frag *old_frag;
      valueT       old_value;
      valueT       new_value;

      assert (S_GET_SEGMENT (label) == now_seg);

      old_frag  = symbol_get_frag (label);
      old_value = S_GET_VALUE (label);
      new_value = (valueT) frag_now_fix ();

      /* It is possible to have more than one label at a particular
	 address, especially if debugging is enabled, so we must
	 take care to adjust all the labels at this address in this
	 fragment.  To save time we search from the end of the symbol
	 list, backwards, since the symbols we are interested in are
	 almost certainly the ones that were most recently added.
	 Also to save time we stop searching once we have seen at least
	 one matching label, and we encounter a label that is no longer
	 in the target fragment.  Note, this search is guaranteed to
	 find at least one match when sym == label, so no special case
	 code is necessary.  */
      for (sym = symbol_lastP; sym != NULL; sym = symbol_previous (sym))
	{
	  if (symbol_get_frag (sym) == old_frag
	      && S_GET_VALUE (sym) == old_value)
	    {
	      label_seen = true;
	      symbol_set_frag (sym, frag_now);
	      S_SET_VALUE (sym, new_value);
	    }
	  else if (label_seen && symbol_get_frag (sym) != old_frag)
	    break;
	}
    }

  record_alignment (now_seg, n);
}

/* Handle the .align pseudo-op.  This aligns to a power of two.  We
   hook here to latch the current alignment.  */

static void
s_d30v_align (ignore)
     int ignore;
{
  int align;
  char fill, *pfill = NULL;
  long max_alignment = 15;

  align = get_absolute_expression ();
  if (align > max_alignment)
    {
      align = max_alignment;
      as_warn (_("Alignment too large: %d assumed"), align);
    }
  else if (align < 0)
    {
      as_warn (_("Alignment negative: 0 assumed"));
      align = 0;
    }

  if (*input_line_pointer == ',')
    {
      input_line_pointer++;
      fill = get_absolute_expression ();
      pfill = &fill;
    }

  d30v_last_label = NULL;
  d30v_align (align, pfill, NULL);

  demand_empty_rest_of_line ();
}

/* Handle the .text pseudo-op.  This is like the usual one, but it
   clears the saved last label and resets known alignment.  */

static void
s_d30v_text (i)
     int i;

{
  s_text (i);
  d30v_last_label = NULL;
  d30v_current_align = 0;
  d30v_current_align_seg = now_seg;
}

/* Handle the .data pseudo-op.  This is like the usual one, but it
   clears the saved last label and resets known alignment.  */

static void
s_d30v_data (i)
     int i;
{
  s_data (i);
  d30v_last_label = NULL;
  d30v_current_align = 0;
  d30v_current_align_seg = now_seg;
}

/* Handle the .section pseudo-op.  This is like the usual one, but it
   clears the saved last label and resets known alignment.  */

static void
s_d30v_section (ignore)
     int ignore;
{
  obj_elf_section (ignore);
  d30v_last_label = NULL;
  d30v_current_align = 0;
  d30v_current_align_seg = now_seg;
}