m88k.c

linux下的gcc编译器

	      || (REG_P (addr) && REGNO (addr) == 1))
	    {
	      operands[1] = dest;
	      return (REG_P (addr)
		      ? "jsr %0\n\tbr %l1"
		      : (flag_pic
			 ? "bsr %0#plt\n\tbr %l1"
			 : "bsr %0\n\tbr %l1"));
	    }

	  /* Output the short branch form.  */
	  output_asm_insn ((REG_P (addr)
			    ? "jsr.n %0"
			    : (flag_pic ? "bsr.n %0#plt" : "bsr.n %0")),
			   operands);

#ifdef USE_GAS
	  last = (delta < 0
		  ? "subu %#r1,%#r1,.-%l0+4"
		  : "addu %#r1,%#r1,%l0-.-4");
	  operands[0] = dest;
#else
	  operands[0] = gen_label_rtx ();
	  operands[1] = gen_label_rtx ();
	  if (delta < 0)
	    {
	      low = dest;
	      high = operands[1];
	      last = "subu %#r1,%#r1,%l0\n%l1:";
	    }
	  else
	    {
	      low = operands[1];
	      high = dest;
	      last = "addu %#r1,%#r1,%l0\n%l1:";
	    }

	  /* Record the values to be computed later as "def name,high-low".  */
	  sb_name = gen_rtx_EXPR_LIST (VOIDmode, operands[0], sb_name);
	  sb_high = gen_rtx_EXPR_LIST (VOIDmode, high, sb_high);
	  sb_low = gen_rtx_EXPR_LIST (VOIDmode, low, sb_low);
#endif /* Don't USE_GAS */

	  return last;
	}
    }
  return (REG_P (addr)
	  ? "jsr%. %0"
	  : (flag_pic ? "bsr%. %0#plt" : "bsr%. %0"));
}

static void
output_short_branch_defs (stream)
     FILE *stream;
{
  char name[256], high[256], low[256];

  for (; sb_name && sb_high && sb_low;
       sb_name = XEXP (sb_name, 1),
       sb_high = XEXP (sb_high, 1),
       sb_low = XEXP (sb_low, 1))
    {
      ASM_GENERATE_INTERNAL_LABEL
	(name, "L", CODE_LABEL_NUMBER (XEXP (sb_name, 0)));
      ASM_GENERATE_INTERNAL_LABEL
	(high, "L", CODE_LABEL_NUMBER (XEXP (sb_high, 0)));
      ASM_GENERATE_INTERNAL_LABEL
	(low, "L", CODE_LABEL_NUMBER (XEXP (sb_low, 0)));
      /* This will change as the assembler requirements become known.  */
      fprintf (stream, "%s%s,%s-%s\n",
	       SET_ASM_OP, &name[1], &high[1], &low[1]);
    }
  if (sb_name || sb_high || sb_low)
    abort ();
}

/* Return truth value of the statement that this conditional branch is likely
   to fall through.  CONDITION, is the condition that JUMP_INSN is testing.  */

int
mostly_false_jump (jump_insn, condition)
     rtx jump_insn, condition;
{
  rtx target_label = JUMP_LABEL (jump_insn);
  rtx insnt, insnj;

  /* Much of this isn't computed unless we're optimizing.  */
  if (optimize == 0)
    return 0;

  /* Determine if one path or the other leads to a return.  */
  for (insnt = NEXT_INSN (target_label);
       insnt;
       insnt = NEXT_INSN (insnt))
    {
      if (GET_CODE (insnt) == JUMP_INSN)
	break;
      else if (GET_CODE (insnt) == INSN
	       && GET_CODE (PATTERN (insnt)) == SEQUENCE
	       && GET_CODE (XVECEXP (PATTERN (insnt), 0, 0)) == JUMP_INSN)
	{
	  insnt = XVECEXP (PATTERN (insnt), 0, 0);
	  break;
	}
    }
  if (insnt
      && (GET_CODE (PATTERN (insnt)) == RETURN
	  || (GET_CODE (PATTERN (insnt)) == SET
	      && GET_CODE (SET_SRC (PATTERN (insnt))) == REG
	      && REGNO (SET_SRC (PATTERN (insnt))) == 1)))
    insnt = 0;

  for (insnj = NEXT_INSN (jump_insn);
       insnj;
       insnj = NEXT_INSN (insnj))
    {
      if (GET_CODE (insnj) == JUMP_INSN)
	break;
      else if (GET_CODE (insnj) == INSN
	       && GET_CODE (PATTERN (insnj)) == SEQUENCE
	       && GET_CODE (XVECEXP (PATTERN (insnj), 0, 0)) == JUMP_INSN)
	{
	  insnj = XVECEXP (PATTERN (insnj), 0, 0);
	  break;
	}
    }
  if (insnj
      && (GET_CODE (PATTERN (insnj)) == RETURN
	  || (GET_CODE (PATTERN (insnj)) == SET
	      && GET_CODE (SET_SRC (PATTERN (insnj))) == REG
	      && REGNO (SET_SRC (PATTERN (insnj))) == 1)))
    insnj = 0;

  /* Predict to not return.  */
  if ((insnt == 0) != (insnj == 0))
    return (insnt == 0);

  /* Predict loops to loop.  */
  for (insnt = PREV_INSN (target_label);
       insnt && GET_CODE (insnt) == NOTE;
       insnt = PREV_INSN (insnt))
    if (NOTE_LINE_NUMBER (insnt) == NOTE_INSN_LOOP_END)
      return 1;
    else if (NOTE_LINE_NUMBER (insnt) == NOTE_INSN_LOOP_BEG)
      return 0;
    else if (NOTE_LINE_NUMBER (insnt) == NOTE_INSN_LOOP_CONT)
      return 0;

  /* Predict backward branches usually take.  */
  if (final_sequence)
    insnj = NEXT_INSN (PREV_INSN (XVECEXP (final_sequence, 0, 0)));
  else
    insnj = jump_insn;
  if (INSN_ADDRESSES (INSN_UID (insnj))
      > INSN_ADDRESSES (INSN_UID (target_label)))
    return 0;

  /* EQ tests are usually false and NE tests are usually true.  Also,
     most quantities are positive, so we can make the appropriate guesses
     about signed comparisons against zero.  Consider unsigned comparisons
     to be a range check and assume quantities to be in range.  */
  switch (GET_CODE (condition))
    {
    case CONST_INT:
      /* Unconditional branch.  */
      return 0;
    case EQ:
      return 1;
    case NE:
      return 0;
    case LE:
    case LT:
    case GEU:
    case GTU: /* Must get casesi right at least.  */
      if (XEXP (condition, 1) == const0_rtx)
        return 1;
      break;
    case GE:
    case GT:
    case LEU:
    case LTU:
      if (XEXP (condition, 1) == const0_rtx)
	return 0;
      break;
    default:
      break;
    }

  return 0;
}

/* Return true if the operand is a power of two and is a floating
   point type (to optimize division by power of two into multiplication).  */

int
real_power_of_2_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  REAL_VALUE_TYPE d;
  union {
    long l[2];
    struct {				/* IEEE double precision format */
      unsigned sign	 :  1;
      unsigned exponent  : 11;
      unsigned mantissa1 : 20;
      unsigned mantissa2;
    } s;
    struct {				/* IEEE double format to quick check */
      unsigned sign	 :  1;		/* if it fits in a float */
      unsigned exponent1 :  4;
      unsigned exponent2 :  7;
      unsigned mantissa1 : 20;
      unsigned mantissa2;
    } s2;
  } u;

  if (GET_MODE (op) != DFmode && GET_MODE (op) != SFmode)
    return 0;

  if (GET_CODE (op) != CONST_DOUBLE)
    return 0;

  REAL_VALUE_FROM_CONST_DOUBLE (d, op);
  REAL_VALUE_TO_TARGET_DOUBLE (d, u.l);

  if (u.s.mantissa1 != 0 || u.s.mantissa2 != 0	/* not a power of two */
      || u.s.exponent == 0			/* constant 0.0 */
      || u.s.exponent == 0x7ff			/* NAN */
      || (u.s2.exponent1 != 0x8 && u.s2.exponent1 != 0x7))
    return 0;					/* const won't fit in float */

  return 1;
}

/* Make OP legitimate for mode MODE.  Currently this only deals with DFmode
   operands, putting them in registers and making CONST_DOUBLE values
   SFmode where possible.  */

struct rtx_def *
legitimize_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  rtx temp;
  REAL_VALUE_TYPE r;
  union {
    long l[2];
    struct {				/* IEEE double precision format */
      unsigned sign	 :  1;
      unsigned exponent  : 11;
      unsigned mantissa1 : 20;
      unsigned mantissa2;
    } d;
    struct {				/* IEEE double format to quick check */
      unsigned sign	 :  1;		/* if it fits in a float */
      unsigned exponent1 :  4;
      unsigned exponent2 :  7;
      unsigned mantissa1 : 20;
      unsigned mantissa2;
    } s;
  } u;

  if (GET_CODE (op) == REG || mode != DFmode)
    return op;

  if (GET_CODE (op) == CONST_DOUBLE)
    {
      REAL_VALUE_FROM_CONST_DOUBLE (r, op);
      REAL_VALUE_TO_TARGET_DOUBLE (r, u.l);
      if (u.d.exponent != 0x7ff /* NaN */
	  && u.d.mantissa2 == 0 /* Mantissa fits */
	  && (u.s.exponent1 == 0x8 || u.s.exponent1 == 0x7) /* Exponent fits */
	  && (temp = simplify_unary_operation (FLOAT_TRUNCATE, SFmode,
					       op, mode)) != 0)
	return gen_rtx_FLOAT_EXTEND (mode, force_reg (SFmode, temp));
    }
  else if (register_operand (op, mode))
    return op;

  return force_reg (mode, op);
}

/* Return true if OP is a suitable input for a move insn.  */

int
move_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (register_operand (op, mode))
    return 1;
  if (GET_CODE (op) == CONST_INT)
    return (classify_integer (mode, INTVAL (op)) < m88k_oru_hi16);
  if (GET_MODE (op) != mode)
    return 0;
  if (GET_CODE (op) == SUBREG)
    op = SUBREG_REG (op);
  if (GET_CODE (op) != MEM)
    return 0;

  op = XEXP (op, 0);
  if (GET_CODE (op) == LO_SUM)
    return (REG_P (XEXP (op, 0))
	    && symbolic_address_p (XEXP (op, 1)));
  return memory_address_p (mode, op);
}

/* Return true if OP is suitable for a call insn.  */

int
call_address_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (REG_P (op) || symbolic_address_p (op));
}

/* Returns true if OP is either a symbol reference or a sum of a symbol
   reference and a constant.  */

int
symbolic_address_p (op)
     register rtx op;
{
  switch (GET_CODE (op))
    {
    case SYMBOL_REF:
    case LABEL_REF:
      return 1;

    case CONST:
      op = XEXP (op, 0);
      return ((GET_CODE (XEXP (op, 0)) == SYMBOL_REF
	       || GET_CODE (XEXP (op, 0)) == LABEL_REF)
	      && GET_CODE (XEXP (op, 1)) == CONST_INT);

    default:
      return 0;
    }
}

/* Return true if OP is a register or const0_rtx.  */

int
reg_or_0_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (op == const0_rtx || register_operand (op, mode));
}

/* Nonzero if OP is a valid second operand for an arithmetic insn.  */

int
arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode)
	  || (GET_CODE (op) == CONST_INT && SMALL_INT (op)));
}

/* Return true if OP is a  register or 5 bit integer.  */

int
arith5_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode)
	  || (GET_CODE (op) == CONST_INT && (unsigned) INTVAL (op) < 32));
}

int
arith32_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode) || GET_CODE (op) == CONST_INT);
}

int
arith64_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode)
	  || GET_CODE (op) == CONST_INT
	  || (GET_CODE (op) == CONST_DOUBLE && GET_MODE (op) == VOIDmode));
}

int
int5_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT && (unsigned) INTVAL (op) < 32);
}

int
int32_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT);
}

/* Return true if OP is a register or a valid immediate operand for
   addu or subu.  */

int
add_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode)
	  || (GET_CODE (op) == CONST_INT && ADD_INT (op)));
}

/* Nonzero if this is a bitmask filling the bottom bits, for optimizing and +
   shift left combinations into a single mak instruction.  */

int
mak_mask_p (value)
     int value;
{
  return (value && POWER_OF_2_or_0 (value + 1));
}

int
reg_or_bbx_mask_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  int value;
  if (register_operand (op, mode))
    return 1;
  if (GET_CODE (op) != CONST_INT)
    return 0;

  value = INTVAL (op);
  if (POWER_OF_2 (value))
    return 1;

  return 0;
}

/* Return true if OP is valid to use in the context of a floating
   point operation.  Special case 0.0, since we can use r0.  */

int
real_or_0_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (mode != SFmode && mode != DFmode)
    return 0;

  return (register_operand (op, mode)
	  || (GET_CODE (op) == CONST_DOUBLE
	      && op == CONST0_RTX (mode)));
}

/* Return true if OP is valid to use in the context of logic arithmetic