tc-arm.c

基于4个mips核的noc设计

  if (preserved_copy_of_name[0] == '_')
    preserved_copy_of_name++;
#endif

#ifdef tc_canonicalize_symbol_name
  preserved_copy_of_name =
    tc_canonicalize_symbol_name (preserved_copy_of_name);
#endif

  S_SET_NAME (symbolP, preserved_copy_of_name);

  S_SET_SEGMENT (symbolP, segment);
  S_SET_VALUE (symbolP, valu);
  symbol_clear_list_pointers(symbolP);

  symbol_set_frag (symbolP, frag);

  /* Link to end of symbol chain.  */
  {
    extern int symbol_table_frozen;
    if (symbol_table_frozen)
      abort ();
  }

  symbol_append (symbolP, symbol_lastP, & symbol_rootP, & symbol_lastP);

  obj_symbol_new_hook (symbolP);

#ifdef tc_symbol_new_hook
  tc_symbol_new_hook (symbolP);
#endif

#ifdef DEBUG_SYMS
  verify_symbol_chain (symbol_rootP, symbol_lastP);
#endif /* DEBUG_SYMS  */
}

/* Check that an immediate is valid.
   If so, convert it to the right format.  */

static unsigned int
validate_immediate (val)
     unsigned int val;
{
  unsigned int a;
  unsigned int i;

#define rotate_left(v, n) (v << n | v >> (32 - n))

  for (i = 0; i < 32; i += 2)
    if ((a = rotate_left (val, i)) <= 0xff)
      return a | (i << 7); /* 12-bit pack: [shift-cnt,const].  */

  return FAIL;
}

/* Check to see if an immediate can be computed as two seperate immediate
   values, added together.  We already know that this value cannot be
   computed by just one ARM instruction.  */

static unsigned int
validate_immediate_twopart (val, highpart)
     unsigned int   val;
     unsigned int * highpart;
{
  unsigned int a;
  unsigned int i;

  for (i = 0; i < 32; i += 2)
    if (((a = rotate_left (val, i)) & 0xff) != 0)
      {
	if (a & 0xff00)
	  {
	    if (a & ~ 0xffff)
	      continue;
	    * highpart = (a  >> 8) | ((i + 24) << 7);
	  }
	else if (a & 0xff0000)
	  {
	    if (a & 0xff000000)
	      continue;
	    * highpart = (a >> 16) | ((i + 16) << 7);
	  }
	else
	  {
	    assert (a & 0xff000000);
	    * highpart = (a >> 24) | ((i + 8) << 7);
	  }

	return (a & 0xff) | (i << 7);
      }

  return FAIL;
}

static int
validate_offset_imm (val, hwse)
     unsigned int val;
     int hwse;
{
  if ((hwse && val > 255) || val > 4095)
    return FAIL;
  return val;
}

static void
s_req (a)
     int a ATTRIBUTE_UNUSED;
{
  as_bad (_("Invalid syntax for .req directive."));
}

static void
s_bss (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  /* We don't support putting frags in the BSS segment, we fake it by
     marking in_bss, then looking at s_skip for clues.  */
  subseg_set (bss_section, 0);
  demand_empty_rest_of_line ();
}

static void
s_even (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  /* Never make frag if expect extra pass.  */
  if (!need_pass_2)
    frag_align (1, 0, 0);

  record_alignment (now_seg, 1);

  demand_empty_rest_of_line ();
}

static void
s_ltorg (ignored)
     int ignored ATTRIBUTE_UNUSED;
{
  int lit_count = 0;
  char sym_name[20];

  if (current_poolP == NULL)
    return;

  /* Align pool as you have word accesses.
     Only make a frag if we have to.  */
  if (!need_pass_2)
    frag_align (2, 0, 0);

  record_alignment (now_seg, 2);

  sprintf (sym_name, "$$lit_\002%x", lit_pool_num++);

  symbol_locate (current_poolP, sym_name, now_seg,
		 (valueT) frag_now_fix (), frag_now);
  symbol_table_insert (current_poolP);

  ARM_SET_THUMB (current_poolP, thumb_mode);

#if defined OBJ_COFF || defined OBJ_ELF
  ARM_SET_INTERWORK (current_poolP, support_interwork);
#endif

  while (lit_count < next_literal_pool_place)
    /* First output the expression in the instruction to the pool.  */
    emit_expr (&(literals[lit_count++].exp), 4); /* .word  */

  next_literal_pool_place = 0;
  current_poolP = NULL;
}

/* Same as s_align_ptwo but align 0 => align 2.  */

static void
s_align (unused)
     int unused ATTRIBUTE_UNUSED;
{
  register int temp;
  register long temp_fill;
  long max_alignment = 15;

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

  if (*input_line_pointer == ',')
    {
      input_line_pointer++;
      temp_fill = get_absolute_expression ();
    }
  else
    temp_fill = 0;

  if (!temp)
    temp = 2;

  /* Only make a frag if we HAVE to.  */
  if (temp && !need_pass_2)
    frag_align (temp, (int) temp_fill, 0);
  demand_empty_rest_of_line ();

  record_alignment (now_seg, temp);
}

static void
s_force_thumb (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  /* If we are not already in thumb mode go into it, EVEN if
     the target processor does not support thumb instructions.
     This is used by gcc/config/arm/lib1funcs.asm for example
     to compile interworking support functions even if the
     target processor should not support interworking.  */
  if (! thumb_mode)
    {
      thumb_mode = 2;

      record_alignment (now_seg, 1);
    }

  demand_empty_rest_of_line ();
}

static void
s_thumb_func (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  if (! thumb_mode)
    opcode_select (16);

  /* The following label is the name/address of the start of a Thumb function.
     We need to know this for the interworking support.  */
  label_is_thumb_function_name = true;

  demand_empty_rest_of_line ();
}

/* Perform a .set directive, but also mark the alias as
   being a thumb function.  */

static void
s_thumb_set (equiv)
     int equiv;
{
  /* XXX the following is a duplicate of the code for s_set() in read.c
     We cannot just call that code as we need to get at the symbol that
     is created.  */
  register char *    name;
  register char      delim;
  register char *    end_name;
  register symbolS * symbolP;

  /* Especial apologies for the random logic:
     This just grew, and could be parsed much more simply!
     Dean - in haste.  */
  name      = input_line_pointer;
  delim     = get_symbol_end ();
  end_name  = input_line_pointer;
  *end_name = delim;

  SKIP_WHITESPACE ();

  if (*input_line_pointer != ',')
    {
      *end_name = 0;
      as_bad (_("Expected comma after name \"%s\""), name);
      *end_name = delim;
      ignore_rest_of_line ();
      return;
    }

  input_line_pointer++;
  *end_name = 0;

  if (name[0] == '.' && name[1] == '\0')
    {
      /* XXX - this should not happen to .thumb_set.  */
      abort ();
    }

  if ((symbolP = symbol_find (name)) == NULL
      && (symbolP = md_undefined_symbol (name)) == NULL)
    {
#ifndef NO_LISTING
      /* When doing symbol listings, play games with dummy fragments living
	 outside the normal fragment chain to record the file and line info
         for this symbol.  */
      if (listing & LISTING_SYMBOLS)
	{
	  extern struct list_info_struct * listing_tail;
	  fragS * dummy_frag = (fragS *) xmalloc (sizeof (fragS));

	  memset (dummy_frag, 0, sizeof (fragS));
	  dummy_frag->fr_type = rs_fill;
	  dummy_frag->line = listing_tail;
	  symbolP = symbol_new (name, undefined_section, 0, dummy_frag);
	  dummy_frag->fr_symbol = symbolP;
	}
      else
#endif
	symbolP = symbol_new (name, undefined_section, 0, &zero_address_frag);

#ifdef OBJ_COFF
      /* "set" symbols are local unless otherwise specified.  */
      SF_SET_LOCAL (symbolP);
#endif /* OBJ_COFF  */
    }				/* Make a new symbol.  */

  symbol_table_insert (symbolP);

  * end_name = delim;

  if (equiv
      && S_IS_DEFINED (symbolP)
      && S_GET_SEGMENT (symbolP) != reg_section)
    as_bad (_("symbol `%s' already defined"), S_GET_NAME (symbolP));

  pseudo_set (symbolP);

  demand_empty_rest_of_line ();

  /* XXX Now we come to the Thumb specific bit of code.  */

  THUMB_SET_FUNC (symbolP, 1);
  ARM_SET_THUMB (symbolP, 1);
#if defined OBJ_ELF || defined OBJ_COFF
  ARM_SET_INTERWORK (symbolP, support_interwork);
#endif
}

/* If we change section we must dump the literal pool first.  */

static void
arm_s_text (ignore)
     int ignore;
{
  if (now_seg != text_section)
    s_ltorg (0);

#ifdef OBJ_ELF
  obj_elf_text (ignore);
#else
  s_text (ignore);
#endif
}

static void
arm_s_data (ignore)
     int ignore;
{
  if (flag_readonly_data_in_text)
    {
      if (now_seg != text_section)
	s_ltorg (0);
    }
  else if (now_seg != data_section)
    s_ltorg (0);

#ifdef OBJ_ELF
  obj_elf_data (ignore);
#else
  s_data (ignore);
#endif
}

#ifdef OBJ_ELF
static void
arm_s_section (ignore)
     int ignore;
{
  s_ltorg (0);

  obj_elf_section (ignore);
}
#endif

static void
opcode_select (width)
     int width;
{
  switch (width)
    {
    case 16:
      if (! thumb_mode)
	{
	  if (! (cpu_variant & ARM_EXT_THUMB))
	    as_bad (_("selected processor does not support THUMB opcodes"));

	  thumb_mode = 1;
	  /* No need to force the alignment, since we will have been
             coming from ARM mode, which is word-aligned.  */
	  record_alignment (now_seg, 1);
	}
      break;

    case 32:
      if (thumb_mode)
	{
	  if ((cpu_variant & ARM_ANY) == ARM_EXT_THUMB)
	    as_bad (_("selected processor does not support ARM opcodes"));

	  thumb_mode = 0;

	  if (!need_pass_2)
            frag_align (2, 0, 0);

          record_alignment (now_seg, 1);
	}
      break;

    default:
      as_bad (_("invalid instruction size selected (%d)"), width);
    }
}

static void
s_arm (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  opcode_select (32);
  demand_empty_rest_of_line ();
}

static void
s_thumb (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  opcode_select (16);
  demand_empty_rest_of_line ();
}

static void
s_code (unused)
     int unused ATTRIBUTE_UNUSED;
{
  register int temp;

  temp = get_absolute_expression ();