tc-arm.c

基于4个mips核的noc设计

  switch (temp)
    {
    case 16:
    case 32:
      opcode_select (temp);
      break;

    default:
      as_bad (_("invalid operand to .code directive (%d) (expecting 16 or 32)"), temp);
    }
}

static void
end_of_line (str)
     char * str;
{
  skip_whitespace (str);

  if (* str != '\0')
    inst.error = _("Garbage following instruction");
}

static int
skip_past_comma (str)
     char ** str;
{
  char * p = * str, c;
  int comma = 0;

  while ((c = *p) == ' ' || c == ',')
    {
      p++;
      if (c == ',' && comma++)
	return FAIL;
    }

  if (c == '\0')
    return FAIL;

  *str = p;
  return comma ? SUCCESS : FAIL;
}

/* A standard register must be given at this point.
   SHIFT is the place to put it in inst.instruction.
   Restores input start point on error.
   Returns the reg#, or FAIL.  */

static int
reg_required_here (str, shift)
     char ** str;
     int     shift;
{
  static char buff [128]; /* XXX  */
  int         reg;
  char *      start = * str;

  if ((reg = arm_reg_parse (str)) != FAIL && int_register (reg))
    {
      if (shift >= 0)
	inst.instruction |= reg << shift;
      return reg;
    }

  /* Restore the start point, we may have got a reg of the wrong class.  */
  *str = start;

  /* In the few cases where we might be able to accept something else
     this error can be overridden.  */
  sprintf (buff, _("Register expected, not '%.100s'"), start);
  inst.error = buff;

  return FAIL;
}

static CONST struct asm_psr *
arm_psr_parse (ccp)
     register char ** ccp;
{
  char * start = * ccp;
  char   c;
  char * p;
  CONST struct asm_psr * psr;

  p = start;

  /* Skip to the end of the next word in the input stream.  */
  do
    {
      c = *p++;
    }
  while (isalpha (c) || c == '_');

  /* Terminate the word.  */
  *--p = 0;

  /* CPSR's and SPSR's can now be lowercase.  This is just a convenience
     feature for ease of use and backwards compatibility.  */
  if (!strncmp (start, "cpsr", 4))
    strncpy (start, "CPSR", 4);
  else if (!strncmp (start, "spsr", 4))
    strncpy (start, "SPSR", 4);

  /* Now locate the word in the psr hash table.  */
  psr = (CONST struct asm_psr *) hash_find (arm_psr_hsh, start);

  /* Restore the input stream.  */
  *p = c;

  /* If we found a valid match, advance the
     stream pointer past the end of the word.  */
  *ccp = p;

  return psr;
}

/* Parse the input looking for a PSR flag.  */

static int
psr_required_here (str)
     char ** str;
{
  char * start = * str;
  CONST struct asm_psr * psr;

  psr = arm_psr_parse (str);

  if (psr)
    {
      /* If this is the SPSR that is being modified, set the R bit.  */
      if (! psr->cpsr)
	inst.instruction |= SPSR_BIT;

      /* Set the psr flags in the MSR instruction.  */
      inst.instruction |= psr->field << PSR_SHIFT;

      return SUCCESS;
    }

  /* In the few cases where we might be able to accept
     something else this error can be overridden.  */
  inst.error = _("flag for {c}psr instruction expected");

  /* Restore the start point.  */
  *str = start;
  return FAIL;
}

static int
co_proc_number (str)
     char ** str;
{
  int processor, pchar;

  skip_whitespace (* str);

  /* The data sheet seems to imply that just a number on its own is valid
     here, but the RISC iX assembler seems to accept a prefix 'p'.  We will
     accept either.  */
  if (**str == 'p' || **str == 'P')
    (*str)++;

  pchar = *(*str)++;
  if (pchar >= '0' && pchar <= '9')
    {
      processor = pchar - '0';
      if (**str >= '0' && **str <= '9')
	{
	  processor = processor * 10 + *(*str)++ - '0';
	  if (processor > 15)
	    {
	      inst.error = _("Illegal co-processor number");
	      return FAIL;
	    }
	}
    }
  else
    {
      inst.error = _("Bad or missing co-processor number");
      return FAIL;
    }

  inst.instruction |= processor << 8;
  return SUCCESS;
}

static int
cp_opc_expr (str, where, length)
     char ** str;
     int where;
     int length;
{
  expressionS expr;

  skip_whitespace (* str);

  memset (&expr, '\0', sizeof (expr));

  if (my_get_expression (&expr, str))
    return FAIL;
  if (expr.X_op != O_constant)
    {
      inst.error = _("bad or missing expression");
      return FAIL;
    }

  if ((expr.X_add_number & ((1 << length) - 1)) != expr.X_add_number)
    {
      inst.error = _("immediate co-processor expression too large");
      return FAIL;
    }

  inst.instruction |= expr.X_add_number << where;
  return SUCCESS;
}

static int
cp_reg_required_here (str, where)
     char ** str;
     int     where;
{
  int    reg;
  char * start = *str;

  if ((reg = arm_reg_parse (str)) != FAIL && cp_register (reg))
    {
      reg &= 15;
      inst.instruction |= reg << where;
      return reg;
    }

  /* In the few cases where we might be able to accept something else
     this error can be overridden.  */
  inst.error = _("Co-processor register expected");

  /* Restore the start point.  */
  *str = start;
  return FAIL;
}

static int
fp_reg_required_here (str, where)
     char ** str;
     int     where;
{
  int    reg;
  char * start = * str;

  if ((reg = arm_reg_parse (str)) != FAIL && fp_register (reg))
    {
      reg &= 7;
      inst.instruction |= reg << where;
      return reg;
    }

  /* In the few cases where we might be able to accept something else
     this error can be overridden.  */
  inst.error = _("Floating point register expected");

  /* Restore the start point.  */
  *str = start;
  return FAIL;
}

static int
cp_address_offset (str)
     char ** str;
{
  int offset;

  skip_whitespace (* str);

  if (! is_immediate_prefix (**str))
    {
      inst.error = _("immediate expression expected");
      return FAIL;
    }

  (*str)++;

  if (my_get_expression (& inst.reloc.exp, str))
    return FAIL;

  if (inst.reloc.exp.X_op == O_constant)
    {
      offset = inst.reloc.exp.X_add_number;

      if (offset & 3)
	{
	  inst.error = _("co-processor address must be word aligned");
	  return FAIL;
	}

      if (offset > 1023 || offset < -1023)
	{
	  inst.error = _("offset too large");
	  return FAIL;
	}

      if (offset >= 0)
	inst.instruction |= INDEX_UP;
      else
	offset = -offset;

      inst.instruction |= offset >> 2;
    }
  else
    inst.reloc.type = BFD_RELOC_ARM_CP_OFF_IMM;

  return SUCCESS;
}

static int
cp_address_required_here (str)
     char ** str;
{
  char * p = * str;
  int    pre_inc = 0;
  int    write_back = 0;

  if (*p == '[')
    {
      int reg;

      p++;
      skip_whitespace (p);

      if ((reg = reg_required_here (& p, 16)) == FAIL)
	return FAIL;

      skip_whitespace (p);

      if (*p == ']')
	{
	  p++;

	  if (skip_past_comma (& p) == SUCCESS)
	    {
	      /* [Rn], #expr  */
	      write_back = WRITE_BACK;

	      if (reg == REG_PC)
		{
		  inst.error = _("pc may not be used in post-increment");
		  return FAIL;
		}

	      if (cp_address_offset (& p) == FAIL)
		return FAIL;
	    }
	  else
	    pre_inc = PRE_INDEX | INDEX_UP;
	}
      else
	{
	  /* '['Rn, #expr']'[!]  */

	  if (skip_past_comma (& p) == FAIL)
	    {
	      inst.error = _("pre-indexed expression expected");
	      return FAIL;
	    }

	  pre_inc = PRE_INDEX;

	  if (cp_address_offset (& p) == FAIL)
	    return FAIL;

	  skip_whitespace (p);

	  if (*p++ != ']')
	    {
	      inst.error = _("missing ]");
	      return FAIL;
	    }

	  skip_whitespace (p);

	  if (*p == '!')
	    {
	      if (reg == REG_PC)
		{
		  inst.error = _("pc may not be used with write-back");
		  return FAIL;
		}

	      p++;
	      write_back = WRITE_BACK;
	    }
	}
    }
  else
    {
      if (my_get_expression (&inst.reloc.exp, &p))
	return FAIL;

      inst.reloc.type = BFD_RELOC_ARM_CP_OFF_IMM;
      inst.reloc.exp.X_add_number -= 8;  /* PC rel adjust.  */
      inst.reloc.pc_rel = 1;
      inst.instruction |= (REG_PC << 16);
      pre_inc = PRE_INDEX;
    }

  inst.instruction |= write_back | pre_inc;
  *str = p;
  return SUCCESS;
}

static void
do_nop (str, flags)
     char * str;
     unsigned long flags;
{
  /* Do nothing really.  */
  inst.instruction |= flags; /* This is pointless.  */
  end_of_line (str);
  return;
}

static void
do_mrs (str, flags)
     char *str;
     unsigned long flags;
{
  int skip = 0;

  /* Only one syntax.  */
  skip_whitespace (str);

  if (reg_required_here (&str, 12) == FAIL)
    {
      inst.error = BAD_ARGS;
      return;
    }

  if (skip_past_comma (&str) == FAIL)
    {
      inst.error = _("comma expected after register name");
      return;
    }

  skip_whitespace (str);

  if (   strcmp (s