tc-h8500.c

基于4个mips核的noc设计

	  return;
	}
      else
	{
	  /* must be a symbol */
	  *ptr =
	    skip_colonthing (exp_unsigned, src, op,
			     ispage ? ABS24 : ABS16, ABS8, ABS16, ABS24);
	  return;
	}
    }

  if (*src == '#')
    {
      src++;
      *ptr = skip_colonthing (exp_sandu, src, op, IMM16, IMM8, IMM16, ABS24);
      return;
    }
  else
    {
      *ptr = skip_colonthing (exp_signed, src, op,
			      ispage ? ABS24 : PCREL8, PCREL8, PCREL16, ABS24);
    }
}

static char *
get_operands (info, args, operand)
     h8500_opcode_info *info;
     char *args;
     h8500_operand_info *operand;

{
  char *ptr = args;

  switch (info->nargs)
    {
    case 0:
      operand[0].type = 0;
      operand[1].type = 0;
      break;

    case 1:
      ptr++;
      get_operand (&ptr, operand + 0, info->name[0] == 'p');
      operand[1].type = 0;
      break;

    case 2:
      ptr++;
      get_operand (&ptr, operand + 0, 0);
      if (*ptr == ',')
	ptr++;
      get_operand (&ptr, operand + 1, 0);
      break;

    default:
      abort ();
    }

  return ptr;
}

/* Passed a pointer to a list of opcodes which use different
   addressing modes, return the opcode which matches the opcodes
   provided.  */

int pcrel8;			/* Set when we've seen a pcrel operand */

static h8500_opcode_info *
get_specific (opcode, operands)
     h8500_opcode_info *opcode;
     h8500_operand_info *operands;
{
  h8500_opcode_info *this_try = opcode;
  int found = 0;
  unsigned int noperands = opcode->nargs;

  unsigned int this_index = opcode->idx;

  while (this_index == opcode->idx && !found)
    {
      unsigned int i;

      this_try = opcode++;

      /* look at both operands needed by the opcodes and provided by
       the user*/
      for (i = 0; i < noperands; i++)
	{
	  h8500_operand_info *user = operands + i;

	  switch (this_try->arg_type[i])
	    {
	    case FPIND_D8:
	      /* Opcode needs (disp:8,fp) */
	      if (user->type == RNIND_D8 && user->reg == 6)
		{
		  displacement = user->exp;
		  continue;
		}
	      break;
	    case RDIND_D16:
	      if (user->type == RNIND_D16)
		{
		  displacement = user->exp;
		  rd = user->reg;
		  continue;
		}
	      break;
	    case RDIND_D8:
	      if (user->type == RNIND_D8)
		{
		  displacement = user->exp;
		  rd = user->reg;
		  continue;
		}
	      break;
	    case RNIND_D16:
	    case RNIND_D8:
	      if (user->type == this_try->arg_type[i])
		{
		  displacement = user->exp;
		  rn = user->reg;
		  continue;
		}
	      break;

	    case SPDEC:
	      if (user->type == RNDEC && user->reg == 7)
		{
		  continue;
		}
	      break;
	    case SPINC:
	      if (user->type == RNINC && user->reg == 7)
		{
		  continue;
		}
	      break;
	    case ABS16:
	      if (user->type == ABS16)
		{
		  absolute = user->exp;
		  continue;
		}
	      break;
	    case ABS8:
	      if (user->type == ABS8)
		{
		  absolute = user->exp;
		  continue;
		}
	      break;
	    case ABS24:
	      if (user->type == ABS24)
		{
		  absolute = user->exp;
		  continue;
		}
	      break;

	    case CRB:
	      if ((user->type == CRB || user->type == CR) && user->reg != 0)
		{
		  crb = user->reg;
		  continue;
		}
	      break;
	    case CRW:
	      if ((user->type == CRW || user->type == CR) && user->reg == 0)
		{
		  crw = user->reg;
		  continue;
		}
	      break;
	    case DISP16:
	      if (user->type == DISP16)
		{
		  displacement = user->exp;
		  continue;
		}
	      break;
	    case DISP8:
	      if (user->type == DISP8)
		{
		  displacement = user->exp;
		  continue;
		}
	      break;
	    case FP:
	      if (user->type == RN && user->reg == 6)
		{
		  continue;
		}
	      break;
	    case PCREL16:
	      if (user->type == PCREL16)
		{
		  displacement = user->exp;
		  continue;
		}
	      break;
	    case PCREL8:
	      if (user->type == PCREL8)
		{
		  displacement = user->exp;
		  pcrel8 = 1;
		  continue;
		}
	      break;

	    case IMM16:
	      if (user->type == IMM16
		  || user->type == IMM8)
		{
		  immediate_inpage = user->page;
		  immediate = user->exp;
		  continue;
		}
	      break;
	    case RLIST:
	    case IMM8:
	      if (user->type == IMM8)
		{
		  immediate_inpage = user->page;
		  immediate = user->exp;
		  continue;
		}
	      break;
	    case IMM4:
	      if (user->type == IMM8)
		{
		  immediate_inpage = user->page;
		  immediate = user->exp;
		  continue;
		}
	      break;
	    case QIM:
	      if (user->type == IMM8
		  && user->exp.X_op == O_constant
		  &&
		  (user->exp.X_add_number == -2
		   || user->exp.X_add_number == -1
		   || user->exp.X_add_number == 1
		   || user->exp.X_add_number == 2))
		{
		  immediate_inpage = user->page;
		  immediate = user->exp;
		  continue;
		}
	      break;
	    case RD:
	      if (user->type == RN)
		{
		  rd = user->reg;
		  continue;
		}
	      break;
	    case RS:
	      if (user->type == RN)
		{
		  rs = user->reg;
		  continue;
		}
	      break;
	    case RDIND:
	      if (user->type == RNIND)
		{
		  rd = user->reg;
		  continue;

		}
	      break;
	    case RNINC:
	    case RNIND:
	    case RNDEC:
	    case RN:

	      if (user->type == this_try->arg_type[i])
		{
		  rn = user->reg;
		  continue;
		}
	      break;
	    case SP:
	      if (user->type == RN && user->reg == 7)
		{
		  continue;
		}
	      break;
	    default:
	      printf (_("unhandled %d\n"), this_try->arg_type[i]);
	      break;
	    }

	  /* If we get here this didn't work out */
	  goto fail;
	}
      found = 1;
    fail:;

    }

  if (found)
    return this_try;
  else
    return 0;
}

int
check (operand, low, high)
     expressionS *operand;
     int low;
     int high;
{
  if (operand->X_op != O_constant
      || operand->X_add_number < low
      || operand->X_add_number > high)
    {
      as_bad (_("operand must be absolute in range %d..%d"), low, high);
    }
  return operand->X_add_number;
}

static void
insert (output, index, exp, reloc, pcrel)
     char *output;
     int index;
     expressionS *exp;
     int reloc;
     int pcrel;
{
  fix_new_exp (frag_now,
	       output - frag_now->fr_literal + index,
	       4,	       	/* always say size is 4, but we know better */
	       exp,
	       pcrel,
	       reloc);
}

void
build_relaxable_instruction (opcode, operand)
     h8500_opcode_info *opcode;
     h8500_operand_info *operand;
{
  /* All relaxable instructions start life as two bytes but can become
     three bytes long if a lonely branch and up to 9 bytes if long
     scb.  */
  char *p;
  int len;
  int type;

  if (opcode->bytes[0].contents == 0x01)
    {
      type = SCB_F;
    }
  else if (opcode->bytes[0].contents == 0x06
	   || opcode->bytes[0].contents == 0x07)
    {
      type = SCB_TST;
    }
  else
    {
      type = BRANCH;
    }

  p = frag_var (rs_machine_dependent,
		md_relax_table[C (type, WORD_DISP)].rlx_length,
		len = md_relax_table[C (type, BYTE_DISP)].rlx_length,
		C (type, UNDEF_BYTE_DISP),
		displacement.X_add_symbol,
		displacement.X_add_number,
		0);

  p[0] = opcode->bytes[0].contents;
  if (type != BRANCH)
    {
      p[1] = opcode->bytes[1].contents | rs;
    }
}

/* Now we know what sort of opcodes it is, let's build the bytes.  */

static void
build_bytes (opcode, operand)
     h8500_opcode_info *opcode;
     h8500_operand_info *operand;

{
  int index;

  if (pcrel8)
    {
      pcrel8 = 0;
      build_relaxable_instruction (opcode, operand);
    }
  else
    {
      char *output = frag_more (opcode->length);

      memset (output, 0, opcode->length);
      for (index = 0; index < opcode->length; index++)
	{
	  output[index] = opcode->bytes[index].contents;

	  switch (opcode->bytes[index].insert)
	    {
	    default:
	      printf (_("failed for %d\n"), opcode->bytes[index].insert);
	      break;
	    case 0:
	      break;
	    case RN:
	      output[index] |= rn;
	      break;
	    case RD:
	    case RDIND:
	      output[index] |= rd;
	      break;
	    case RS:
	      output[index] |= rs;
	      break;
	    case DISP16:
	      insert (output, index, &displacement, R_H8500_IMM16, 0);
	      index++;
	      break;
	    case DISP8:
	    case FPIND_D8:
	      insert (output, index, &displacement, R_H8500_IMM8, 0);
	      break;
	    case IMM16:
	      {
		int p;

		switch (immediate_inpage)
		  {
		  case 'p':
		    p = R_H8500_HIGH16;
		    break;
		  case 'h':
		    p = R_H8500_HIGH16;
		    break;
		  default:
		    p = R_H8500_IMM16;
		    break;
		  }
		insert (output, index, &immediate, p, 0);
	      }
	      index++;
	      break;
	    case RLIST:
	    case IMM8:
	      if (immediate_inpage)
		insert (output, index, &immediate, R_H8500_HIGH8, 0);
	      else
		insert (output, index, &immediate, R_H8500_IMM8, 0);
	      break;
	    case PCREL16:
	      insert (output, index, &displacement, R_H8500_PCREL16, 1);
	      index++;
	      break;
	    case PCREL8:
	      insert (output, index, &displacement, R_H8500_PCREL8, 1);
	      break;
	    case IMM4:
	      output[index] |= check (&immediate, 0, 15);
	      break;
	    case CR:
	      output[index] |= cr;
	      if (cr == 0)
		output[0] |= 0x8;
	      else
		output[0] &= ~0x8;
	      break;
	    case CRB:
	      output[index] |= crb;
	      output[0] &= ~0x8;
	      break;
	    case CRW:
	      output[index] |= crw;
	      output[0] |= 0x8;
	      break;
	    case ABS24:
	      insert (output, index, &absolute, R_H8500_IMM24, 0);
	      index += 2;
	      break;
	    case ABS16:
	      insert (output, index, &absolute, R_H8500_IMM16, 0);
	      index++;
	      break;
	    case ABS8:
	      insert (output, index, &absolute, R_H8500_IMM8, 0);
	      break;
	    case QIM:
	      switch (immediate.X_add_number)
		{
		case -2:
		  output[index] |= 0x5;
		  break;
		case -1:
		  output[index] |= 0x4;
		  break;
		case 1:
		  output[index] |= 0;
		  break;
		case 2:
		  output[index] |= 1;
		  break;
		}
	      break;
	    }
	}
    }
}

/* This is the guts of the machine-dependent assembler.  STR points to
   a machine dependent instruction.  This function is supposed to emit
   the frags/bytes it assembles to.  */

void
md_assemble (str)
     char *str;
{
  char *op_start;
  char *op_end;
  h8500_operand_info operand[2];
  h8500_opcode_info *opcode;
  h8500_opcode_info *prev_opcode;
  char name[11];

  int nlen = 0;

  /* Drop leading whitespace.  */
  while (*str == ' ')
    str++;