pa.c

gcc-2.95.3 Linux下最常用的C编译器

	      && GET_MODE (op) == mode
	      && VAL_14_BITS_P (CONST_DOUBLE_LOW (op))
	      && ((CONST_DOUBLE_HIGH (op) >= 0)
		  == ((CONST_DOUBLE_LOW (op) & 0x1000) == 0))));
}

/* Return truth value of whether OP is a integer which fits the
   range constraining immediate operands in three-address insns, or
   is an integer register.  */

int
ireg_or_int5_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return ((GET_CODE (op) == CONST_INT && INT_5_BITS (op))
	  || (GET_CODE (op) == REG && REGNO (op) > 0 && REGNO (op) < 32));
}

/* Return truth value of whether OP is a integer which fits the
   range constraining immediate operands in three-address insns.  */

int
int5_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT && INT_5_BITS (op));
}

int
uint5_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT && INT_U5_BITS (op));
}

int
int11_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT && INT_11_BITS (op));
}

int
uint32_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
#if HOST_BITS_PER_WIDE_INT > 32
  /* All allowed constants will fit a CONST_INT.  */
  return (GET_CODE (op) == CONST_INT
	  && (INTVAL (op) >= 0 && INTVAL (op) < 0x100000000L));
#else
  return (GET_CODE (op) == CONST_INT
	  || (GET_CODE (op) == CONST_DOUBLE
	      && CONST_DOUBLE_HIGH (op) == 0));
#endif
}

int
arith5_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return register_operand (op, mode) || int5_operand (op, mode);
}

/* True iff zdepi can be used to generate this CONST_INT.  */
int
zdepi_cint_p (x)
     unsigned HOST_WIDE_INT x;
{
  unsigned HOST_WIDE_INT lsb_mask, t;

  /* This might not be obvious, but it's at least fast.
     This function is critical; we don't have the time loops would take.  */
  lsb_mask = x & -x;
  t = ((x >> 4) + lsb_mask) & ~(lsb_mask - 1);
  /* Return true iff t is a power of two.  */
  return ((t & (t - 1)) == 0);
}

/* True iff depi or extru can be used to compute (reg & mask).
   Accept bit pattern like these:
   0....01....1
   1....10....0
   1..10..01..1  */
int
and_mask_p (mask)
     unsigned HOST_WIDE_INT mask;
{
  mask = ~mask;
  mask += mask & -mask;
  return (mask & (mask - 1)) == 0;
}

/* True iff depi or extru can be used to compute (reg & OP).  */
int
and_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode)
	  || (GET_CODE (op) == CONST_INT && and_mask_p (INTVAL (op))));
}

/* True iff depi can be used to compute (reg | MASK).  */
int
ior_mask_p (mask)
     unsigned HOST_WIDE_INT mask;
{
  mask += mask & -mask;
  return (mask & (mask - 1)) == 0;
}

/* True iff depi can be used to compute (reg | OP).  */
int
ior_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT && ior_mask_p (INTVAL (op)));
}

int
lhs_lshift_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return register_operand (op, mode) || lhs_lshift_cint_operand (op, mode);
}

/* True iff OP is a CONST_INT of the forms 0...0xxxx or 0...01...1xxxx.
   Such values can be the left hand side x in (x << r), using the zvdepi
   instruction.  */
int
lhs_lshift_cint_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  unsigned HOST_WIDE_INT x;
  if (GET_CODE (op) != CONST_INT)
    return 0;
  x = INTVAL (op) >> 4;
  return (x & (x + 1)) == 0;
}

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

int
pc_or_label_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == PC || GET_CODE (op) == LABEL_REF);
}

/* Legitimize PIC addresses.  If the address is already
   position-independent, we return ORIG.  Newly generated
   position-independent addresses go to REG.  If we need more
   than one register, we lose.  */

rtx
legitimize_pic_address (orig, mode, reg)
     rtx orig, reg;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  rtx pic_ref = orig;

  /* Labels need special handling.  */
  if (pic_label_operand (orig))
    {
      emit_insn (gen_pic_load_label (reg, orig));
      current_function_uses_pic_offset_table = 1;
      return reg;
    }
  if (GET_CODE (orig) == SYMBOL_REF)
    {
      if (reg == 0)
	abort ();

      if (flag_pic == 2)
	{
	  emit_insn (gen_pic2_highpart (reg, pic_offset_table_rtx, orig));
	  pic_ref
	    = gen_rtx_MEM (Pmode,
			   gen_rtx_LO_SUM (Pmode, reg,
					   gen_rtx_UNSPEC (SImode,
							   gen_rtvec (1, orig),
							   0)));
	}
      else
	pic_ref = gen_rtx_MEM (Pmode,
			       gen_rtx_PLUS (Pmode,
					     pic_offset_table_rtx, orig));
      current_function_uses_pic_offset_table = 1;
      RTX_UNCHANGING_P (pic_ref) = 1;
      emit_move_insn (reg, pic_ref);
      return reg;
    }
  else if (GET_CODE (orig) == CONST)
    {
      rtx base;

      if (GET_CODE (XEXP (orig, 0)) == PLUS
	  && XEXP (XEXP (orig, 0), 0) == pic_offset_table_rtx)
	return orig;

      if (reg == 0)
	abort ();

      if (GET_CODE (XEXP (orig, 0)) == PLUS)
	{
	  base = legitimize_pic_address (XEXP (XEXP (orig, 0), 0), Pmode, reg);
	  orig = legitimize_pic_address (XEXP (XEXP (orig, 0), 1), Pmode,
					 base == reg ? 0 : reg);
	}
      else abort ();
      if (GET_CODE (orig) == CONST_INT)
	{
	  if (INT_14_BITS (orig))
	    return plus_constant_for_output (base, INTVAL (orig));
	  orig = force_reg (Pmode, orig);
	}
      pic_ref = gen_rtx_PLUS (Pmode, base, orig);
      /* Likewise, should we set special REG_NOTEs here?  */
    }
  return pic_ref;
}

/* Try machine-dependent ways of modifying an illegitimate address
   to be legitimate.  If we find one, return the new, valid address.
   This macro is used in only one place: `memory_address' in explow.c.

   OLDX is the address as it was before break_out_memory_refs was called.
   In some cases it is useful to look at this to decide what needs to be done.

   MODE and WIN are passed so that this macro can use
   GO_IF_LEGITIMATE_ADDRESS.

   It is always safe for this macro to do nothing.  It exists to recognize
   opportunities to optimize the output.

   For the PA, transform:

	memory(X + <large int>)

   into:

	if (<large int> & mask) >= 16
	  Y = (<large int> & ~mask) + mask + 1	Round up.
	else
	  Y = (<large int> & ~mask)		Round down.
	Z = X + Y
	memory (Z + (<large int> - Y));

   This is for CSE to find several similar references, and only use one Z.

   X can either be a SYMBOL_REF or REG, but because combine can not
   perform a 4->2 combination we do nothing for SYMBOL_REF + D where
   D will not fit in 14 bits.

   MODE_FLOAT references allow displacements which fit in 5 bits, so use
   0x1f as the mask.

   MODE_INT references allow displacements which fit in 14 bits, so use
   0x3fff as the mask.

   This relies on the fact that most mode MODE_FLOAT references will use FP
   registers and most mode MODE_INT references will use integer registers.
   (In the rare case of an FP register used in an integer MODE, we depend
   on secondary reloads to clean things up.)


   It is also beneficial to handle (plus (mult (X) (Y)) (Z)) in a special
   manner if Y is 2, 4, or 8.  (allows more shadd insns and shifted indexed
   addressing modes to be used).

   Put X and Z into registers.  Then put the entire expression into
   a register.  */

rtx
hppa_legitimize_address (x, oldx, mode)
     rtx x, oldx ATTRIBUTE_UNUSED;
     enum machine_mode mode;
{
  rtx orig = x;

  if (flag_pic)
    return legitimize_pic_address (x, mode, gen_reg_rtx (Pmode));

  /* Strip off CONST. */
  if (GET_CODE (x) == CONST)
    x = XEXP (x, 0);

  /* Special case.  Get the SYMBOL_REF into a register and use indexing.
     That should always be safe.  */
  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 0)) == REG
      && GET_CODE (XEXP (x, 1)) == SYMBOL_REF)
    {
      rtx reg = force_reg (SImode, XEXP (x, 1));
      return force_reg (SImode, gen_rtx_PLUS (SImode, reg, XEXP (x, 0)));
    }

  /* Note we must reject symbols which represent function addresses
     since the assembler/linker can't handle arithmetic on plabels.  */
  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 1)) == CONST_INT
      && ((GET_CODE (XEXP (x, 0)) == SYMBOL_REF
	   && !FUNCTION_NAME_P (XSTR (XEXP (x, 0), 0)))
	  || GET_CODE (XEXP (x, 0)) == REG))
    {
      rtx int_part, ptr_reg;
      int newoffset;
      int offset = INTVAL (XEXP (x, 1));
      int mask = GET_MODE_CLASS (mode) == MODE_FLOAT ? 0x1f : 0x3fff;

      /* Choose which way to round the offset.  Round up if we
	 are >= halfway to the next boundary.  */
      if ((offset & mask) >= ((mask + 1) / 2))
	newoffset = (offset & ~ mask) + mask + 1;
      else
	newoffset = (offset & ~ mask);

      /* If the newoffset will not fit in 14 bits (ldo), then
	 handling this would take 4 or 5 instructions (2 to load
	 the SYMBOL_REF + 1 or 2 to load the newoffset + 1 to
	 add the new offset and the SYMBOL_REF.)  Combine can
	 not handle 4->2 or 5->2 combinations, so do not create
	 them.  */
      if (! VAL_14_BITS_P (newoffset)
	  && GET_CODE (XEXP (x, 0)) == SYMBOL_REF)
	{
	  rtx const_part
	    = gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (Pmode,
						     XEXP (x, 0),
						     GEN_INT (newoffset)));
	  rtx tmp_reg
	    = force_reg (Pmode,
			 gen_rtx_HIGH (Pmode, const_part));
	  ptr_reg
	    = force_reg (Pmode,
			 gen_rtx_LO_SUM (Pmode, tmp_reg, const_part));
	}
      else
	{
	  if (! VAL_14_BITS_P (newoffset))
	    int_part = force_reg (Pmode, GEN_INT (newoffset));
	  else
	    int_part = GEN_INT (newoffset);

	  ptr_reg = force_reg (Pmode,
			       gen_rtx_PLUS (Pmode,
					     force_reg (Pmode, XEXP (x, 0)),
					     int_part));
	}
      return plus_constant (ptr_reg, offset - newoffset);
    }

  /* Handle (plus (mult (a) (shadd_constant)) (b)).  */

  if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == MULT
      && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
      && shadd_constant_p (INTVAL (XEXP (XEXP (x, 0), 1)))
      && (GET_RTX_CLASS (GET_CODE (XEXP (x, 1))) == 'o'
	  || GET_CODE (XEXP (x, 1)) == SUBREG)
      && GET_CODE (XEXP (x, 1)) != CONST)
    {
      int val = INTVAL (XEXP (XEXP (x, 0), 1));
      rtx reg1, reg2;

      reg1 = XEXP (x, 1);
      if (GET_CODE (reg1) != REG)
	reg1 = force_reg (Pmode, force_operand (reg1, 0));

      reg2 = XEXP (XEXP (x, 0), 0);
      if (GET_CODE (reg2) != REG)
        reg2 = force_reg (Pmode, force_operand (reg2, 0));

      return force_reg (Pmode, gen_rtx_PLUS (Pmode,
					     gen_rtx_MULT (Pmode, reg2,
						           GEN_INT (val)),
					     reg1));
    }

  /* Similarly for (plus (plus (mult (a) (shadd_constant)) (b)) (c)).

     Only do so for floating point modes since this is more speculative
     and we lose if it's an integer store.  */
  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 0)) == PLUS
      && GET_CODE (XEXP (XEXP (x, 0), 0)) == MULT
      && GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 1)) == CONST_INT
      && shadd_constant_p (INTVAL (XEXP (XEXP (XEXP (x, 0), 0), 1)))
      && (mode == SFmode || mode == DFmode))
    {

      /* First, try and figure out what to use as a base register.  */
      rtx reg1, reg2, base, idx, orig_base;

      reg1 = XEXP (XEXP (x, 0), 1);
      reg2 = XEXP (x, 1);
      base = NULL_RTX;
      idx = NULL_RTX;

      /* Make sure they're both regs.  If one was a SYMBOL_REF [+ const],
	 then emit_move_sequence will turn on REGNO_POINTER_FLAG so we'll
	 know it's a base register below.  */
      if (GET_CODE (reg1) != REG)
	reg1 = force_reg (Pmode, force_operand (reg1, 0));

      if (GET_CODE (reg2) != REG)
	reg2 = force_reg (Pmode, force_operand (reg2, 0));

      /* Figure out what the base and index are.  */
	 
      if (GET_CODE (reg1) == REG
	  && REGNO_POINTER_FLAG (REGNO (reg1)))
	{
	  base = reg1;
	  orig_base = XEXP (XEXP (x, 0), 1);
	  idx = gen_rtx_PLUS (Pmode,
			      gen_rtx_MULT (Pmode,
					    XEXP (XEXP (XEXP (x, 0), 0), 0),
					    XEXP (XEXP (XEXP (x, 0), 0), 1)),
			      XEXP (x, 1));
	}
      else if (GET_CODE (reg2) == REG
	       && REGNO_POINTER_FLAG (REGNO (reg2)))
	{
	  base = reg2;
	  orig_base = XEXP (x, 1);
	  idx = XEXP (x, 0);
	}

      if (base == 0)
	return orig;

      /* If the index adds a large constant, try to scale the
	 constant so that it can be loaded with only one insn.  */
      if (GET_CODE (XEXP (idx, 1)) == CONST_INT
	  && VAL_14_BITS_P (INTVAL (XEXP (idx, 1))
			    / INTVAL (XEXP (XEXP (idx, 0), 1)))
	  && INTVAL (XEXP (idx, 1)) % INTVAL (XEXP (XEXP (idx, 0), 1)) == 0)
	{
	  /* Divide the CONST_INT by the scale factor, then add it to A.  */
	  int val = INTVAL (XEXP (idx, 1));

	  val /= INTVAL (XEXP (XEXP (idx, 0), 1));