rs6000.c

早期freebsd实现

	  || GET_CODE (XEXP (XEXP (SET_SRC (elt), 0), 1)) != CONST_INT
	  || INTVAL (XEXP (XEXP (SET_SRC (elt), 0), 1)) != i * 4)
	return 0;
    }

  return 1;
}

/* Similar, but tests for store multiple.  Here, the second vector element
   is a CLOBBER.  It will be tested later.  */

int
store_multiple_operation (op, mode)
     rtx op;
     enum machine_mode mode;
{
  int count = XVECLEN (op, 0) - 1;
  int src_regno;
  rtx dest_addr;
  int i;

  /* Perform a quick check so we don't blow up below.  */
  if (count <= 1
      || GET_CODE (XVECEXP (op, 0, 0)) != SET
      || GET_CODE (SET_DEST (XVECEXP (op, 0, 0))) != MEM
      || GET_CODE (SET_SRC (XVECEXP (op, 0, 0))) != REG)
    return 0;

  src_regno = REGNO (SET_SRC (XVECEXP (op, 0, 0)));
  dest_addr = XEXP (SET_DEST (XVECEXP (op, 0, 0)), 0);

  for (i = 1; i < count; i++)
    {
      rtx elt = XVECEXP (op, 0, i + 1);

      if (GET_CODE (elt) != SET
	  || GET_CODE (SET_SRC (elt)) != REG
	  || GET_MODE (SET_SRC (elt)) != SImode
	  || REGNO (SET_SRC (elt)) != src_regno + i
	  || GET_CODE (SET_DEST (elt)) != MEM
	  || GET_MODE (SET_DEST (elt)) != SImode
	  || GET_CODE (XEXP (SET_DEST (elt), 0)) != PLUS
	  || ! rtx_equal_p (XEXP (XEXP (SET_DEST (elt), 0), 0), dest_addr)
	  || GET_CODE (XEXP (XEXP (SET_DEST (elt), 0), 1)) != CONST_INT
	  || INTVAL (XEXP (XEXP (SET_DEST (elt), 0), 1)) != i * 4)
	return 0;
    }

  return 1;
}

/* Return 1 if OP is a comparison operation that is valid for a branch insn.
   We only check the opcode against the mode of the CC value here.  */

int
branch_comparison_operator (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  enum rtx_code code = GET_CODE (op);
  enum machine_mode cc_mode;

  if (GET_RTX_CLASS (code) != '<')
    return 0;

  cc_mode = GET_MODE (XEXP (op, 0));
  if (GET_MODE_CLASS (cc_mode) != MODE_CC)
    return 0;

  if ((code == GT || code == LT || code == GE || code == LE)
      && cc_mode == CCUNSmode)
    return 0;

  if ((code == GTU || code == LTU || code == GEU || code == LEU)
      && (cc_mode != CCUNSmode))
    return 0;

  return 1;
}

/* Return 1 if OP is a comparison operation that is valid for an scc insn.
   We check the opcode against the mode of the CC value and disallow EQ or
   NE comparisons for integers.  */

int
scc_comparison_operator (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  enum rtx_code code = GET_CODE (op);
  enum machine_mode cc_mode;

  if (GET_MODE (op) != mode && mode != VOIDmode)
    return 0;

  if (GET_RTX_CLASS (code) != '<')
    return 0;

  cc_mode = GET_MODE (XEXP (op, 0));
  if (GET_MODE_CLASS (cc_mode) != MODE_CC)
    return 0;

  if (code == NE && cc_mode != CCFPmode)
    return 0;

  if ((code == GT || code == LT || code == GE || code == LE)
      && cc_mode == CCUNSmode)
    return 0;

  if ((code == GTU || code == LTU || code == GEU || code == LEU)
      && (cc_mode != CCUNSmode))
    return 0;

  if (cc_mode == CCEQmode && code != EQ && code != NE)
    return 0;

  return 1;
}

/* Return 1 if ANDOP is a mask that has no bits on that are not in the
   mask required to convert the result of a rotate insn into a shift
   left insn of SHIFTOP bits.  Both are known to be CONST_INT.  */

int
includes_lshift_p (shiftop, andop)
     register rtx shiftop;
     register rtx andop;
{
  int shift_mask = (~0 << INTVAL (shiftop));

  return (INTVAL (andop) & ~shift_mask) == 0;
}

/* Similar, but for right shift.  */

int
includes_rshift_p (shiftop, andop)
     register rtx shiftop;
     register rtx andop;
{
  unsigned shift_mask = ~0;

  shift_mask >>= INTVAL (shiftop);

  return (INTVAL (andop) & ~ shift_mask) == 0;
}

/* Return the register class of a scratch register needed to copy IN into
   or out of a register in CLASS in MODE.  If it can be done directly,
   NO_REGS is returned.  */

enum reg_class
secondary_reload_class (class, mode, in)
     enum reg_class class;
     enum machine_mode mode;
     rtx in;
{
  int regno = true_regnum (in);

  if (regno >= FIRST_PSEUDO_REGISTER)
    regno = -1;

  /* We can place anything into GENERAL_REGS and can put GENERAL_REGS
     into anything.  */
  if (class == GENERAL_REGS || class == BASE_REGS
      || (regno >= 0 && INT_REGNO_P (regno)))
    return NO_REGS;

  /* Constants, memory, and FP registers can go into FP registers.  */
  if ((regno == -1 || FP_REGNO_P (regno))
      && (class == FLOAT_REGS || class == NON_SPECIAL_REGS))
    return NO_REGS;

  /* We can copy among the CR registers.  */
  if ((class == CR_REGS || class == CR0_REGS)
      && regno >= 0 && CR_REGNO_P (regno))
    return NO_REGS;

  /* Otherwise, we need GENERAL_REGS.  */
  return GENERAL_REGS;
}

/* Given a comparison operation, return the bit number in CCR to test.  We
   know this is a valid comparison.  

   SCC_P is 1 if this is for an scc.  That means that %D will have been
   used instead of %C, so the bits will be in different places.

   Return -1 if OP isn't a valid comparison for some reason.  */

int
ccr_bit (op, scc_p)
     register rtx op;
     int scc_p;
{
  enum rtx_code code = GET_CODE (op);
  enum machine_mode cc_mode;
  int cc_regnum;
  int base_bit;

  if (GET_RTX_CLASS (code) != '<')
    return -1;

  cc_mode = GET_MODE (XEXP (op, 0));
  cc_regnum = REGNO (XEXP (op, 0));
  base_bit = 4 * (cc_regnum - 68);

  /* In CCEQmode cases we have made sure that the result is always in the
     third bit of the CR field.  */

  if (cc_mode == CCEQmode)
    return base_bit + 3;

  switch (code)
    {
    case NE:
      return scc_p ? base_bit + 3 : base_bit + 2;
    case EQ:
      return base_bit + 2;
    case GT:  case GTU:
      return base_bit + 1;
    case LT:  case LTU:
      return base_bit;

    case GE:  case GEU:
      /* If floating-point, we will have done a cror to put the bit in the
	 unordered position.  So test that bit.  For integer, this is ! LT
	 unless this is an scc insn.  */
      return cc_mode == CCFPmode || scc_p ? base_bit + 3 : base_bit;

    case LE:  case LEU:
      return cc_mode == CCFPmode || scc_p ? base_bit + 3 : base_bit + 1;

    default:
      abort ();
    }
}

/* Print an operand.  Recognize special options, documented below.  */

void
print_operand (file, x, code)
    FILE *file;
    rtx x;
    char code;
{
  int i;
  int val;

  /* These macros test for integers and extract the low-order bits.  */
#define INT_P(X)  \
((GET_CODE (X) == CONST_INT || GET_CODE (X) == CONST_DOUBLE)	\
 && GET_MODE (X) == VOIDmode)

#define INT_LOWPART(X) \
  (GET_CODE (X) == CONST_INT ? INTVAL (X) : CONST_DOUBLE_LOW (X))

  switch (code)
    {
    case 'h':
      /* If constant, output low-order five bits.  Otherwise,
	 write normally. */
      if (INT_P (x))
	fprintf (file, "%d", INT_LOWPART (x) & 31);
      else
	print_operand (file, x, 0);
      return;

    case 'H':
      /* X must be a constant.  Output the low order 5 bits plus 24.  */
      if (! INT_P (x))
	output_operand_lossage ("invalid %%H value");

      fprintf (file, "%d", (INT_LOWPART (x) + 24) & 31);
      return;

    case 'b':
      /* Low-order 16 bits of constant, unsigned.  */
      if (! INT_P (x))
	output_operand_lossage ("invalid %%b value");

      fprintf (file, "%d", INT_LOWPART (x) & 0xffff);
      return;

    case 'w':
      /* If constant, low-order 16 bits of constant, signed.  Otherwise, write
	 normally.  */
      if (INT_P (x))
	fprintf (file, "%d",
		 (INT_LOWPART (x) & 0xffff) - 2 * (INT_LOWPART (x) & 0x8000));
      else
	print_operand (file, x, 0);
      return;

    case 'W':
      /* If constant, low-order 16 bits of constant, unsigned.
	 Otherwise, write normally.  */
      if (INT_P (x))
	fprintf (file, "%d", INT_LOWPART (x) & 0xffff);
      else
	print_operand (file, x, 0);
      return;

    case 'u':
      /* High-order 16 bits of constant.  */
      if (! INT_P (x))
	output_operand_lossage ("invalid %%u value");

      fprintf (file, "%d", (INT_LOWPART (x) >> 16) & 0xffff);
      return;

    case 's':
      /* Low 5 bits of 32 - value */
      if (! INT_P (x))
	output_operand_lossage ("invalid %%s value");

      fprintf (file, "%d", (32 - INT_LOWPART (x)) & 31);
      return;

    case 'S':
      /* Low 5 bits of 31 - value */
      if (! INT_P (x))
	output_operand_lossage ("invalid %%S value");

      fprintf (file, "%d", (31 - INT_LOWPART (x)) & 31);
      return;

    case 'p':
      /* X is a CONST_INT that is a power of two.  Output the logarithm.  */
      if (! INT_P (x)
	  || (i = exact_log2 (INT_LOWPART (x))) < 0)
	output_operand_lossage ("invalid %%p value");

      fprintf (file, "%d", i);
      return;

    case 'm':
      /* MB value for a mask operand.  */
      if (! mask_operand (x, VOIDmode))
	output_operand_lossage ("invalid %%m value");

      val = INT_LOWPART (x);

      /* If the high bit is set and the low bit is not, the value is zero.
	 If the high bit is zero, the value is the first 1 bit we find from
	 the left.  */
      if (val < 0 && (val & 1) == 0)
	{
	  fprintf (file, "0");
	  return;
	}
      else if (val >= 0)
	{
	  for (i = 1; i < 32; i++)
	    if ((val <<= 1) < 0)
	      break;
	  fprintf (file, "%d", i);
	  return;
	}
	  
      /* Otherwise, look for the first 0 bit from the right.  The result is its
	 number plus 1. We know the low-order bit is one.  */
      for (i = 0; i < 32; i++)
	if (((val >>= 1) & 1) == 0)
	  break;

      /* If we ended in ...01, I would be 0.  The correct value is 31, so
	 we want 31 - i.  */
      fprintf (file, "%d", 31 - i);
      return;

    case 'M':
      /* ME value for a mask operand.  */
      if (! mask_operand (x, VOIDmode))
	output_operand_lossage ("invalid %%m value");

      val = INT_LOWPART (x);

      /* If the low bit is set and the high bit is not, the value is 31.
	 If the low bit is zero, the value is the first 1 bit we find from
	 the right.  */
      if ((val & 1) && val >= 0)
	{
	  fprintf (file, "31");
	  return;
	}
      else if ((val & 1) == 0)
	{
	  for (i = 0; i < 32; i++)
	    if ((val >>= 1) & 1)
	      break;

	  /* If we had ....10, I would be 0.  The result should be
	     30, so we need 30 - i.  */
	  fprintf (file, "%d", 30 - i);
	  return;
	}
	  
      /* Otherwise, look for the first 0 bit from the left.  The result is its
	 number minus 1. We know the high-order bit is one.  */
      for (i = 0; i < 32; i++)
	if ((val <<= 1) >= 0)
	  break;

      fprintf (file, "%d", i);
      return;

    case 'f':
      /* X is a CR register.  Print the shift count needed to move it
	 to the high-order four bits.  */
      if (GET_CODE (x) != REG || ! CR_REGNO_P (REGNO (x)))
	output_operand_lossage ("invalid %%f value");
      else
	fprintf (file, "%d", 4 * (REGNO (x) - 68));
      return;

    case 'F':
      /* Similar, but print the count for the rotate in the opposite
	 direction.  */
      if (GET_CODE (x) != REG || ! CR_REGNO_P (REGNO (x)))
	output_operand_lossage ("invalid %%F value");
      else
	fprintf (file, "%d", 32 - 4 * (REGNO (x) - 68));
      return;

    case 'E':
      /* X is a CR register.  Print the number of the third bit of the CR */
      if (GET_CODE (x) != REG || ! CR_REGNO_P (REGNO (x)))
	output_operand_lossage ("invalid %%E value");

      fprintf(file, "%d", 4 * (REGNO (x) - 68) + 3);
      break;

    case 'R':
      /* X is a CR register.  Print the mask for `mtcrf'.  */
      if (GET_CODE (x) != REG || ! CR_REGNO_P (REGNO (x)))
	output_operand_lossage ("invalid %%R value");
      else
	fprintf (file, "%d", 128 >> (REGNO (x) - 68));
      return;

    case 'X':
      if (GET_CODE (x) == MEM
	  && LEGITIMATE_INDEXED_ADDRESS_P (XEXP (x, 0)))
	fprintf (file, "x");
      return;

    case 'U':
      /* Print `u' is this has an auto-increment or auto-decrement.  */
      if (GET_CODE (x) == MEM
	  && (GET_CODE (XEXP (x, 0)) == PRE_INC
	      || GET_CODE (XEXP (x, 0)) == PRE_DEC))