pa.c

早期freebsd实现

     rtx X;
{
  if (GET_CODE (X) == PLUS)
      return 1;
  else if (GET_CODE (X) == LO_SUM)
    return 1;
  else if (GET_CODE (X) == HIGH)
    return 2;
  return 4;
}

/* Emit insns to move operands[1] into operands[0].

   Return 1 if we have written out everything that needs to be done to
   do the move.  Otherwise, return 0 and the caller will emit the move
   normally.  */

int
emit_move_sequence (operands, mode, scratch_reg)
     rtx *operands;
     enum machine_mode mode;
     rtx scratch_reg;
{
  register rtx operand0 = operands[0];
  register rtx operand1 = operands[1];

  if (fp_reg_operand (operand0, mode)
      && GET_CODE (operand1) == MEM
      && !short_memory_operand  (operand1, mode)
      && scratch_reg)
    {
      emit_move_insn (scratch_reg, XEXP (operand1 , 0));
      emit_insn (gen_rtx (SET, VOIDmode, operand0, gen_rtx (MEM, mode,
							    scratch_reg)));
      return 1;
    }
  else if (fp_reg_operand (operand1, mode)
	   && GET_CODE (operand0) == MEM
	   && !short_memory_operand  (operand0, mode)
	   && scratch_reg)
    {
      emit_move_insn (scratch_reg, XEXP (operand0 , 0));
      emit_insn (gen_rtx (SET, VOIDmode, gen_rtx (MEM, mode,  scratch_reg),
			  operand1));
      return 1;
    }
  /* Handle most common case: storing into a register.  */
  else if (register_operand (operand0, mode))
    {
      if (register_operand (operand1, mode)
	  || (GET_CODE (operand1) == CONST_INT && SMALL_INT (operand1))
	  || (GET_CODE (operand1) == HIGH
	      && !symbolic_operand (XEXP (operand1, 0)))
	  /* Only `general_operands' can come here, so MEM is ok.  */
	  || GET_CODE (operand1) == MEM)
	{
	  /* Run this case quickly.  */
	  emit_insn (gen_rtx (SET, VOIDmode, operand0, operand1));
	  return 1;
	}
    }
  else if (GET_CODE (operand0) == MEM)
    {
      if (register_operand (operand1, mode) || operand1 == const0_rtx)
	{
	  /* Run this case quickly.  */
	  emit_insn (gen_rtx (SET, VOIDmode, operand0, operand1));
	  return 1;
	}
      if (! reload_in_progress)
	{
	  operands[0] = validize_mem (operand0);
	  operands[1] = operand1 = force_reg (mode, operand1);
	}
    }

  /* Simplify the source if we need to.  */
  if (GET_CODE (operand1) != HIGH && immediate_operand (operand1, mode))
    {
      if (symbolic_operand (operand1, mode))
	{
	  if (flag_pic)
	    {
	      rtx temp = reload_in_progress ? operand0 : gen_reg_rtx (Pmode);
	      operands[1] = legitimize_pic_address (operand1, mode, temp);
	    }
	  /* On the HPPA, references to data space are supposed to */
	  /* use dp, register 27. */
	  else if (read_only_operand (operand1))
	    {
	      rtx set = gen_rtx (SET, VOIDmode,
				  operand0,
				  gen_rtx (LO_SUM, mode, operand0, operand1));
				 
	      emit_insn (gen_rtx (SET, VOIDmode,
				  operand0,
				  gen_rtx (HIGH, mode, operand1)));
	      if (TARGET_SHARED_LIBS
		  && function_label_operand (operand1, mode))
		{
		  rtx temp = reload_in_progress ? scratch_reg
		    : gen_reg_rtx (mode);
		  if (!temp)
		    abort ();
		  emit_insn (gen_rtx (PARALLEL, VOIDmode,
				      gen_rtvec (2,
						 set,
						 gen_rtx (CLOBBER, VOIDmode,
							  temp))));
		}
	      else
		emit_insn (set);
	      return 1;
	    }
	  else
	    {
	      /* If reload_in_progress, we can't use addil and r1; we */
	      /* have to use the more expensive ldil sequence. */
	      if (reload_in_progress)
		{
		  emit_insn (gen_rtx (SET, VOIDmode,
				      operand0,
				      gen_rtx (HIGH, mode, operand1)));
		  emit_insn (gen_rtx (SET, VOIDmode,
				      operand0,
				      gen_rtx (PLUS, mode,
					       operand0,
					       gen_rtx (REG, mode, 27))));
		  emit_insn (gen_rtx (SET, VOIDmode,
				      operand0,
				      gen_rtx (LO_SUM, mode,
					       operand0, operand1)));
		}
	      else
		{
		  rtx temp1, temp2 = gen_reg_rtx (mode);

		  /* For 2.4 we could set RTX_UNCHANGING and add a 
		     REG_EQUAL note for the first insn.  This would 
		     allow the first insn to be moved out of loops.  */
		  temp1 = gen_rtx (HIGH, mode, operand1);
		  emit_insn (gen_rtx (SET, VOIDmode,
				      temp2,
				      gen_rtx (PLUS, mode,
					       gen_rtx (REG, mode, 27),
					       temp1)));
		  emit_insn (gen_rtx (SET, VOIDmode,
				      operand0,
				      gen_rtx (LO_SUM, mode,
					       temp2, operand1)));
		}
	      return 1;
	    }
	}
      else if (depi_cint_operand (operand1, VOIDmode))
	return 0;
      else if (GET_CODE (operand1) == CONST_INT
	       ? (! SMALL_INT (operand1)
		  && (INTVAL (operand1) & 0x7ff) != 0) : 1)
	{
	  rtx temp = reload_in_progress ? operand0 : gen_reg_rtx (mode);
	  emit_insn (gen_rtx (SET, VOIDmode, temp,
			      gen_rtx (HIGH, mode, operand1)));
	  operands[1] = gen_rtx (LO_SUM, mode, temp, operand1);
	}
    }
  /* Now have insn-emit do whatever it normally does.  */
  return 0;
}

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

int
read_only_operand (operand)
     rtx operand;
{
  if (GET_CODE (operand) == CONST)
    operand = XEXP (XEXP (operand, 0), 0);
  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.  */

char *
singlemove_string (operands)
     rtx *operands;
{
  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_INT)
    if (INT_14_BITS (operands[1]))
      return (INTVAL (operands[1]) == 0 ? "copy 0,%0" : "ldi %1,%0");
    else
      return "ldil L'%1,%0\n\tldo R'%1(%0),%0";
  return "copy %1,%0";
}


/* Compute position (in OPERANDS[2]) and width (in OPERANDS[3])
   useful for copying or or'ing IMM to a register using bit field
   instructions.  Store the immediate value to insert in OPERANDS[1].  */
void
compute_xdepi_operands_from_integer (imm, operands)
     unsigned imm;
     rtx *operands;
{
  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;
    }

  operands[1] = gen_rtx (CONST_INT, VOIDmode, imm);
  operands[2] = gen_rtx (CONST_INT, VOIDmode, 31 - lsb);
  operands[3] = gen_rtx (CONST_INT, VOIDmode, len);
}

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

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,ma %1,8(0,%0)\n\tstw %R1,-4(0,%0)";
	      return "stws,ma %1,-8(0,%0)\n\tstw %R1,12(0,%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,mb %1,8(0,%0)\n\tstw %R1,4(0,%0)";
	      return "stws,mb %1,-8(0,%0)\n\tstw %R1,4(0,%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,ma 8(0,%1),%0\n\tldw -4(0,%1),%R0";
	      return "ldws,ma -8(0,%1),%0\n\tldw 12(0,%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(0,%1),%R0\n\tldws,ma 8(0,%1),%0";
	      return "ldw 4(0,%1),%R0\n\tldws,ma -8(0,%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,mb 8(0,%1),%0\n\tldw 4(0,%1),%R0";
	      return "ldws,mb -8(0,%1),%0\n\tldw 4(0,%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(0,%1),%R0\n\tldws,mb 8(0,%1),%0";
	      return "ldw -4(0,%1),%R0\n\tldws,mb -8(0,%1),%0";
	    }
	}
    }

  /* If an operand is an unoffsettable memory ref, find a register
     we can increment temporarily to make it refer to the second word.  */

  if (optype0 == MEMOP)
    addreg0 = find_addr_reg (XEXP (operands[0], 0));

  if (optype1 == MEMOP)
    addreg1 = find_addr_reg (XEXP (operands[1], 0));

  /* Ok, we can do one word at a time.
     Normally we do the low-numbered word first.

     In either case, set up in LATEHALF the operands to use
     for the high-numbered word and in some cases alter the
     operands in OPERANDS to be suitable for the low-numbered word.  */

  if (optype0 == REGOP)
    latehalf[0] = gen_rtx (REG, SImode, REGNO (operands[0]) + 1);
  else if (optype0 == OFFSOP)
    latehalf[0] = adj_offsettable_operand (operands[0], 4);
  else
    latehalf[0] = operands[0];

  if (optype1 == REGOP)
    latehalf[1] = gen_rtx (REG, SImode, REGNO (operands[1]) + 1);
  else if (optype1 == OFFSOP)
    latehalf[1] = adj_offsettable_operand (operands[1], 4);
  else if (optype1 == CNSTOP)
    split_double (operands[1], &operands[1], &latehalf[1]);
  else
    latehalf[1] = operands[1];

  /* If the first move would clobber the source of the second one,
     do them in the other order.

     RMS says "This happens only for registers;
     such overlap can't happen in memory unless the user explicitly
     sets it up, and that is an undefined circumstance."

     but it happens on the HP-PA when loading parameter registers,
     so I am going to define that circumstance, and make it work
     as expected.  */

  if (optype0 == REGOP && (optype1 == MEMOP || optype1 == OFFSOP)
	   && reg_overlap_mentioned_p (operands[0], XEXP (operands[1], 0)))
    {
      /* XXX THIS PROBABLY DOESN'T WORK.  */
      /* Do the late half first.  */
      if (addreg1)
	output_asm_insn ("ldo 4(%0),%0", &addreg1);
      output_asm_insn (singlemove_string (latehalf), latehalf);
      if (addreg1)
	output_asm_insn ("ldo -4(%0),%0", &addreg1);
      /* Then clobber.  */
      return singlemove_string (operands);
    }

  if (optype0 == REGOP && optype1 == REGOP
      && REGNO (operands[0]) == REGNO (operands[1]) + 1)
    {
      output_asm_insn (singlemove_string (latehalf), latehalf);
      return singlemove_string (operands);
    }

  /* Normal case: do the two words, low-numbered first.  */

  output_asm_insn (singlemove_string (operands), operands);

  /* Make any unoffsettable addresses point at high-numbered word.  */
  if (addreg0)
    output_asm_insn ("ldo 4(%0),%0", &addreg0);
  if (addreg1)
    output_asm_insn ("ldo 4(%0),%0", &addreg1);

  /* Do that word.  */
  output_asm_insn (singlemove_string (latehalf), latehalf);

  /* Undo the adds we just did.  */
  if (addreg0)
    output_asm_insn ("ldo -4(%0),%0", &addreg0);
  if (addreg1)
    output_asm_insn ("ldo -4(%0),%0", &addreg1);

  return "";
}

char *
output_fp_move_double (operands)
     rtx *operands;
{
  if (FP_REG_P (operands[0]))
    {
      if (FP_REG_P (operands[1]))
	output_asm_insn ("fcpy,dbl %1,%0", operands);
      else if (GET_CODE (operands[1]) == REG)
	{
	  rtx xoperands[3];
	  xoperands[0] = operands[0];
	  xoperands[1] = operands[1];
	  xoperands[2] = gen_rtx (REG, SImode, REGNO (operands[1]) + 1);
	  output_asm_insn
	    ("stw %1,-16(0,30)\n\tstw %2,-12(0,30)\n\tfldds -16(0,30),%0",
			   xoperands);
	}
      else 
	output_asm_insn ("fldds%F1 %1,%0", operands);
    }
  else if (FP_REG_P (operands[1]))
    {