pa.c

linux下的gcc编译器

	  if (TARGET_64BIT && GET_CODE (operand1) == CONST_INT
	      && HOST_BITS_PER_WIDE_INT > 32
	      && GET_MODE_BITSIZE (GET_MODE (operand0)) > 32)
	    {
	      HOST_WIDE_INT val = INTVAL (operand1);
	      HOST_WIDE_INT nval;

	      /* Extract the low order 32 bits of the value and sign extend.
		 If the new value is the same as the original value, we can
		 can use the original value as-is.  If the new value is
		 different, we use it and insert the most-significant 32-bits
		 of the original value into the final result.  */
	      nval = ((val & (((HOST_WIDE_INT) 2 << 31) - 1))
		      ^ ((HOST_WIDE_INT) 1 << 31)) - ((HOST_WIDE_INT) 1 << 31);
	      if (val != nval)
		{
#if HOST_BITS_PER_WIDE_INT > 32
		  extend = GEN_INT (val >> 32);
#endif
		  operand1 = GEN_INT (nval);
		}
	    }

	  if (reload_in_progress || reload_completed)
	    temp = operand0;
	  else
	    temp = gen_reg_rtx (mode);

	  /* We don't directly split DImode constants on 32-bit targets
	     because PLUS uses an 11-bit immediate and the insn sequence
	     generated is not as efficient as the one using HIGH/LO_SUM.  */
	  if (GET_CODE (operand1) == CONST_INT
	      && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
	    {
	      /* Directly break constant into high and low parts.  This
		 provides better optimization opportunities because various
		 passes recognize constants split with PLUS but not LO_SUM.
		 We use a 14-bit signed low part except when the addition
		 of 0x4000 to the high part might change the sign of the
		 high part.  */
	      HOST_WIDE_INT value = INTVAL (operand1);
	      HOST_WIDE_INT low = value & 0x3fff;
	      HOST_WIDE_INT high = value & ~ 0x3fff;

	      if (low >= 0x2000)
		{
		  if (high == 0x7fffc000 || (mode == HImode && high == 0x4000))
		    high += 0x2000;
		  else
		    high += 0x4000;
		}

	      low = value - high;

	      emit_insn (gen_rtx_SET (VOIDmode, temp, GEN_INT (high)));
	      operands[1] = gen_rtx_PLUS (mode, temp, GEN_INT (low));
	    }
	  else
	    {
	      emit_insn (gen_rtx_SET (VOIDmode, temp,
				      gen_rtx_HIGH (mode, operand1)));
	      operands[1] = gen_rtx_LO_SUM (mode, temp, operand1);
	    }

	  emit_move_insn (operands[0], operands[1]);

	  if (extend != NULL_RTX)
	    emit_insn (gen_insv (operands[0], GEN_INT (32), const0_rtx,
				 extend));

	  return 1;
	}
    }
  /* Now have insn-emit do whatever it normally does.  */
  return 0;
}

/* Examine EXP and return nonzero if it contains an ADDR_EXPR (meaning
   it will need a link/runtime reloc).  */

int
reloc_needed (exp)
     tree exp;
{
  int reloc = 0;

  switch (TREE_CODE (exp))
    {
    case ADDR_EXPR:
      return 1;

    case PLUS_EXPR:
    case MINUS_EXPR:
      reloc = reloc_needed (TREE_OPERAND (exp, 0));
      reloc |= reloc_needed (TREE_OPERAND (exp, 1));
      break;

    case NOP_EXPR:
    case CONVERT_EXPR:
    case NON_LVALUE_EXPR:
      reloc = reloc_needed (TREE_OPERAND (exp, 0));
      break;

    case CONSTRUCTOR:
      {
	register tree link;
	for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
	  if (TREE_VALUE (link) != 0)
	    reloc |= reloc_needed (TREE_VALUE (link));
      }
      break;

    case ERROR_MARK:
      break;

    default:
      break;
    }
  return reloc;
}

/* Does operand (which is a symbolic_operand) live in text space?
   If so, SYMBOL_REF_FLAG, which is set by pa_encode_section_info,
   will be true.  */

int
read_only_operand (operand, mode)
     rtx operand;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  if (GET_CODE (operand) == CONST)
    operand = XEXP (XEXP (operand, 0), 0);
  if (flag_pic)
    {
      if (GET_CODE (operand) == SYMBOL_REF)
	return SYMBOL_REF_FLAG (operand) && !CONSTANT_POOL_ADDRESS_P (operand);
    }
  else
    {
      if (GET_CODE (operand) == SYMBOL_REF)
	return SYMBOL_REF_FLAG (operand) || CONSTANT_POOL_ADDRESS_P (operand);
    }
  return 1;
}


/* Return the best assembler insn template
   for moving operands[1] into operands[0] as a fullword.   */
const char *
singlemove_string (operands)
     rtx *operands;
{
  HOST_WIDE_INT intval;

  if (GET_CODE (operands[0]) == MEM)
    return "stw %r1,%0";
  if (GET_CODE (operands[1]) == MEM)
    return "ldw %1,%0";
  if (GET_CODE (operands[1]) == CONST_DOUBLE)
    {
      long i;
      REAL_VALUE_TYPE d;

      if (GET_MODE (operands[1]) != SFmode)
	abort ();

      /* Translate the CONST_DOUBLE to a CONST_INT with the same target
	 bit pattern.  */
      REAL_VALUE_FROM_CONST_DOUBLE (d, operands[1]);
      REAL_VALUE_TO_TARGET_SINGLE (d, i);

      operands[1] = GEN_INT (i);
      /* Fall through to CONST_INT case.  */
    }
  if (GET_CODE (operands[1]) == CONST_INT)
    {
      intval = INTVAL (operands[1]);

      if (VAL_14_BITS_P (intval))
	return "ldi %1,%0";
      else if ((intval & 0x7ff) == 0)
	return "ldil L'%1,%0";
      else if (zdepi_cint_p (intval))
	return "{zdepi %Z1,%0|depwi,z %Z1,%0}";
      else
	return "ldil L'%1,%0\n\tldo R'%1(%0),%0";
    }
  return "copy %1,%0";
}


/* Compute position (in OP[1]) and width (in OP[2])
   useful for copying IMM to a register using the zdepi
   instructions.  Store the immediate value to insert in OP[0].  */
static void
compute_zdepwi_operands (imm, op)
     unsigned HOST_WIDE_INT imm;
     unsigned *op;
{
  int lsb, len;

  /* Find the least significant set bit in IMM.  */
  for (lsb = 0; lsb < 32; lsb++)
    {
      if ((imm & 1) != 0)
        break;
      imm >>= 1;
    }

  /* Choose variants based on *sign* of the 5-bit field.  */
  if ((imm & 0x10) == 0)
    len = (lsb <= 28) ? 4 : 32 - lsb;
  else
    {
      /* Find the width of the bitstring in IMM.  */
      for (len = 5; len < 32; len++)
	{
	  if ((imm & (1 << len)) == 0)
	    break;
	}

      /* Sign extend IMM as a 5-bit value.  */
      imm = (imm & 0xf) - 0x10;
    }

  op[0] = imm;
  op[1] = 31 - lsb;
  op[2] = len;
}

/* Compute position (in OP[1]) and width (in OP[2])
   useful for copying IMM to a register using the depdi,z
   instructions.  Store the immediate value to insert in OP[0].  */
void
compute_zdepdi_operands (imm, op)
     unsigned HOST_WIDE_INT imm;
     unsigned *op;
{
  HOST_WIDE_INT lsb, len;

  /* Find the least significant set bit in IMM.  */
  for (lsb = 0; lsb < HOST_BITS_PER_WIDE_INT; lsb++)
    {
      if ((imm & 1) != 0)
        break;
      imm >>= 1;
    }

  /* Choose variants based on *sign* of the 5-bit field.  */
  if ((imm & 0x10) == 0)
    len = ((lsb <= HOST_BITS_PER_WIDE_INT - 4)
	   ? 4 : HOST_BITS_PER_WIDE_INT - lsb);
  else
    {
      /* Find the width of the bitstring in IMM.  */
      for (len = 5; len < HOST_BITS_PER_WIDE_INT; len++)
	{
	  if ((imm & ((unsigned HOST_WIDE_INT) 1 << len)) == 0)
	    break;
	}

      /* Sign extend IMM as a 5-bit value.  */
      imm = (imm & 0xf) - 0x10;
    }

  op[0] = imm;
  op[1] = 63 - lsb;
  op[2] = len;
}

/* Output assembler code to perform a doubleword move insn
   with operands OPERANDS.  */

const char *
output_move_double (operands)
     rtx *operands;
{
  enum { REGOP, OFFSOP, MEMOP, CNSTOP, RNDOP } optype0, optype1;
  rtx latehalf[2];
  rtx addreg0 = 0, addreg1 = 0;

  /* First classify both operands.  */

  if (REG_P (operands[0]))
    optype0 = REGOP;
  else if (offsettable_memref_p (operands[0]))
    optype0 = OFFSOP;
  else if (GET_CODE (operands[0]) == MEM)
    optype0 = MEMOP;
  else
    optype0 = RNDOP;

  if (REG_P (operands[1]))
    optype1 = REGOP;
  else if (CONSTANT_P (operands[1]))
    optype1 = CNSTOP;
  else if (offsettable_memref_p (operands[1]))
    optype1 = OFFSOP;
  else if (GET_CODE (operands[1]) == MEM)
    optype1 = MEMOP;
  else
    optype1 = RNDOP;

  /* Check for the cases that the operand constraints are not
     supposed to allow to happen.  Abort if we get one,
     because generating code for these cases is painful.  */

  if (optype0 != REGOP && optype1 != REGOP)
    abort ();

   /* Handle auto decrementing and incrementing loads and stores
     specifically, since the structure of the function doesn't work
     for them without major modification.  Do it better when we learn
     this port about the general inc/dec addressing of PA.
     (This was written by tege.  Chide him if it doesn't work.)  */

  if (optype0 == MEMOP)
    {
      /* We have to output the address syntax ourselves, since print_operand
	 doesn't deal with the addresses we want to use.  Fix this later.  */

      rtx addr = XEXP (operands[0], 0);
      if (GET_CODE (addr) == POST_INC || GET_CODE (addr) == POST_DEC)
	{
	  rtx high_reg = gen_rtx_SUBREG (SImode, operands[1], 0);

	  operands[0] = XEXP (addr, 0);
	  if (GET_CODE (operands[1]) != REG || GET_CODE (operands[0]) != REG)
	    abort ();

	  if (!reg_overlap_mentioned_p (high_reg, addr))
	    {
	      /* No overlap between high target register and address
		 register.  (We do this in a non-obvious way to
		 save a register file writeback)  */
	      if (GET_CODE (addr) == POST_INC)
		return "{stws|stw},ma %1,8(%0)\n\tstw %R1,-4(%0)";
	      return "{stws|stw},ma %1,-8(%0)\n\tstw %R1,12(%0)";
	    }
	  else
	    abort ();
	}
      else if (GET_CODE (addr) == PRE_INC || GET_CODE (addr) == PRE_DEC)
	{
	  rtx high_reg = gen_rtx_SUBREG (SImode, operands[1], 0);

	  operands[0] = XEXP (addr, 0);
	  if (GET_CODE (operands[1]) != REG || GET_CODE (operands[0]) != REG)
	    abort ();

	  if (!reg_overlap_mentioned_p (high_reg, addr))
	    {
	      /* No overlap between high target register and address
		 register.  (We do this in a non-obvious way to
		 save a register file writeback)  */
	      if (GET_CODE (addr) == PRE_INC)
		return "{stws|stw},mb %1,8(%0)\n\tstw %R1,4(%0)";
	      return "{stws|stw},mb %1,-8(%0)\n\tstw %R1,4(%0)";
	    }
	  else
	    abort ();
	}
    }
  if (optype1 == MEMOP)
    {
      /* We have to output the address syntax ourselves, since print_operand
	 doesn't deal with the addresses we want to use.  Fix this later.  */

      rtx addr = XEXP (operands[1], 0);
      if (GET_CODE (addr) == POST_INC || GET_CODE (addr) == POST_DEC)
	{
	  rtx high_reg = gen_rtx_SUBREG (SImode, operands[0], 0);

	  operands[1] = XEXP (addr, 0);
	  if (GET_CODE (operands[0]) != REG || GET_CODE (operands[1]) != REG)
	    abort ();

	  if (!reg_overlap_mentioned_p (high_reg, addr))
	    {
	      /* No overlap between high target register and address
		 register.  (We do this in a non-obvious way to
		 save a register file writeback)  */
	      if (GET_CODE (addr) == POST_INC)
		return "{ldws|ldw},ma 8(%1),%0\n\tldw -4(%1),%R0";
	      return "{ldws|ldw},ma -8(%1),%0\n\tldw 12(%1),%R0";
	    }
	  else
	    {
	      /* This is an undefined situation.  We should load into the
		 address register *and* update that register.  Probably
		 we don't need to handle this at all.  */
	      if (GET_CODE (addr) == POST_INC)
		return "ldw 4(%1),%R0\n\t{ldws|ldw},ma 8(%1),%0";
	      return "ldw 4(%1),%R0\n\t{ldws|ldw},ma -8(%1),%0";
	    }
	}
      else if (GET_CODE (addr) == PRE_INC || GET_CODE (addr) == PRE_DEC)
	{
	  rtx high_reg = gen_rtx_SUBREG (SImode, operands[0], 0);

	  operands[1] = XEXP (addr, 0);
	  if (GET_CODE (operands[0]) != REG || GET_CODE (operands[1]) != REG)
	    abort ();

	  if (!reg_overlap_mentioned_p (high_reg, addr))
	    {
	      /* No overlap between high target register and address
		 register.  (We do this in a non-obvious way to
		 save a register file writeback)  */
	      if (GET_CODE (addr) == PRE_INC)
		return "{ldws|ldw},mb 8(%1),%0\n\tldw 4(%1),%R0";
	      return "{ldws|ldw},mb -8(%1),%0\n\tldw 4(%1),%R0";
	    }
	  else
	    {
	      /* This is an undefined situation.  We should load into the
		 address register *and* update that register.  Probably
		 we don't need to handle this at all.  */
	      if (GET_CODE (addr) == PRE_INC)
		return "ldw 12(%1),%R0\n\t{ldws|ldw},mb 8(%1),%0";
	      return "ldw -4(%1),%R0\n\t{ldws|ldw},mb -8(%1),%0";
	    }
	}
      else if (GET_CODE (addr) == PLUS
	       && GET_CODE (XEXP (addr, 0)) == MULT)
	{
	  rtx high_reg = gen_rtx_SUBREG (SImode, operands[0], 0);

	  if (!reg_overlap_mentioned_p (high_reg, addr))
	    {
	      rtx xoperands[3];

	      xoperands[0] = high_reg;
	      xoperands[1] = XEXP (addr, 1);
	      xoperands[2] = XEXP (XEXP (addr, 0), 0);
	      xoperands[3] = XEXP (XEXP (addr, 0), 1);
	      output_asm_insn ("{sh%O3addl %2,%1,%0|shladd,l %2,%O3,%1,%0}",
			       xoperands);
	      r