pa.c

gcc-2.95.3 Linux下最常用的C编译器

  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.

     This can happen in two cases:

	mem -> register where the first half of the destination register
 	is the same register used in the memory's address.  Reload
	can create such insns.

	mem in this case will be either register indirect or register
	indirect plus a valid offset. 

	register -> register move where REGNO(dst) == REGNO(src + 1)
	someone (Tim/Tege?) claimed this can happen for parameter loads. 

     Handle mem -> register case first.  */
  if (optype0 == REGOP
      && (optype1 == MEMOP || optype1 == OFFSOP)
      && refers_to_regno_p (REGNO (operands[0]), REGNO (operands[0]) + 1,
			    operands[1], 0))
    {
      /* Do the late half first.  */
      if (addreg1)
	output_asm_insn ("ldo 4(%0),%0", &addreg1);
      output_asm_insn (singlemove_string (latehalf), latehalf);

      /* Then clobber.  */
      if (addreg1)
	output_asm_insn ("ldo -4(%0),%0", &addreg1);
      return singlemove_string (operands);
    }

  /* Now handle register -> register case.  */
  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])
	  || operands[1] == CONST0_RTX (GET_MODE (operands[0])))
	output_asm_insn ("fcpy,dbl %f1,%0", operands);
      else
	output_asm_insn ("fldd%F1 %1,%0", operands);
    }
  else if (FP_REG_P (operands[1]))
    {
      output_asm_insn ("fstd%F0 %1,%0", operands);
    }
  else if (operands[1] == CONST0_RTX (GET_MODE (operands[0])))
    {
      if (GET_CODE (operands[0]) == REG)
	{
	  rtx xoperands[2];
	  xoperands[1] = gen_rtx_REG (SImode, REGNO (operands[0]) + 1);
	  xoperands[0] = operands[0];
	  output_asm_insn ("copy %%r0,%0\n\tcopy %%r0,%1", xoperands);
	}
      /* This is a pain.  You have to be prepared to deal with an
	 arbitrary address here including pre/post increment/decrement.

	 so avoid this in the MD.  */
      else
	abort ();
    }
  else abort ();
  return "";
}

/* Return a REG that occurs in ADDR with coefficient 1.
   ADDR can be effectively incremented by incrementing REG.  */

static rtx
find_addr_reg (addr)
     rtx addr;
{
  while (GET_CODE (addr) == PLUS)
    {
      if (GET_CODE (XEXP (addr, 0)) == REG)
	addr = XEXP (addr, 0);
      else if (GET_CODE (XEXP (addr, 1)) == REG)
	addr = XEXP (addr, 1);
      else if (CONSTANT_P (XEXP (addr, 0)))
	addr = XEXP (addr, 1);
      else if (CONSTANT_P (XEXP (addr, 1)))
	addr = XEXP (addr, 0);
      else
	abort ();
    }
  if (GET_CODE (addr) == REG)
    return addr;
  abort ();
}

/* Emit code to perform a block move.

   OPERANDS[0] is the destination pointer as a REG, clobbered.
   OPERANDS[1] is the source pointer as a REG, clobbered.
   OPERANDS[2] is a register for temporary storage.
   OPERANDS[4] is the size as a CONST_INT
   OPERANDS[3] is a register for temporary storage.
   OPERANDS[5] is the alignment safe to use, as a CONST_INT. 
   OPERANDS[6] is another temporary register.   */

char *
output_block_move (operands, size_is_constant)
     rtx *operands;
     int size_is_constant ATTRIBUTE_UNUSED;
{
  int align = INTVAL (operands[5]);
  unsigned long n_bytes = INTVAL (operands[4]);

  /* We can't move more than four bytes at a time because the PA
     has no longer integer move insns.  (Could use fp mem ops?)  */
  if (align > 4)
    align = 4;

  /* Note that we know each loop below will execute at least twice
     (else we would have open-coded the copy).  */
  switch (align)
    {
      case 4:
	/* Pre-adjust the loop counter.  */
	operands[4] = GEN_INT (n_bytes - 8);
	output_asm_insn ("ldi %4,%2", operands);

	/* Copying loop.  */
	output_asm_insn ("ldws,ma 4(%1),%3", operands);
	output_asm_insn ("ldws,ma 4(%1),%6", operands);
	output_asm_insn ("stws,ma %3,4(%0)", operands);
	output_asm_insn ("addib,>= -8,%2,.-12", operands);
	output_asm_insn ("stws,ma %6,4(%0)", operands);

	/* Handle the residual.  There could be up to 7 bytes of
	   residual to copy!  */
	if (n_bytes % 8 != 0)
	  {
	    operands[4] = GEN_INT (n_bytes % 4);
	    if (n_bytes % 8 >= 4)
	      output_asm_insn ("ldws,ma 4(%1),%3", operands);
	    if (n_bytes % 4 != 0)
	      output_asm_insn ("ldw 0(%1),%6", operands);
	    if (n_bytes % 8 >= 4)
	      output_asm_insn ("stws,ma %3,4(%0)", operands);
	    if (n_bytes % 4 != 0)
	      output_asm_insn ("stbys,e %6,%4(%0)", operands);
	  }
	return "";

      case 2:
	/* Pre-adjust the loop counter.  */
	operands[4] = GEN_INT (n_bytes - 4);
	output_asm_insn ("ldi %4,%2", operands);

	/* Copying loop.  */
	output_asm_insn ("ldhs,ma 2(%1),%3", operands);
	output_asm_insn ("ldhs,ma 2(%1),%6", operands);
	output_asm_insn ("sths,ma %3,2(%0)", operands);
	output_asm_insn ("addib,>= -4,%2,.-12", operands);
	output_asm_insn ("sths,ma %6,2(%0)", operands);

	/* Handle the residual.  */
	if (n_bytes % 4 != 0)
	  {
	    if (n_bytes % 4 >= 2)
	      output_asm_insn ("ldhs,ma 2(%1),%3", operands);
	    if (n_bytes % 2 != 0)
	      output_asm_insn ("ldb 0(%1),%6", operands);
	    if (n_bytes % 4 >= 2)
	      output_asm_insn ("sths,ma %3,2(%0)", operands);
	    if (n_bytes % 2 != 0)
	      output_asm_insn ("stb %6,0(%0)", operands);
	  }
	return "";

      case 1:
	/* Pre-adjust the loop counter.  */
	operands[4] = GEN_INT (n_bytes - 2);
	output_asm_insn ("ldi %4,%2", operands);

	/* Copying loop.  */
	output_asm_insn ("ldbs,ma 1(%1),%3", operands);
	output_asm_insn ("ldbs,ma 1(%1),%6", operands);
	output_asm_insn ("stbs,ma %3,1(%0)", operands);
	output_asm_insn ("addib,>= -2,%2,.-12", operands);
	output_asm_insn ("stbs,ma %6,1(%0)", operands);

	/* Handle the residual.  */
	if (n_bytes % 2 != 0)
	  {
	    output_asm_insn ("ldb 0(%1),%3", operands);
	    output_asm_insn ("stb %3,0(%0)", operands);
	  }
	return "";

      default:
	abort ();
    }
}

/* Count the number of insns necessary to handle this block move.

   Basic structure is the same as emit_block_move, except that we
   count insns rather than emit them.  */

int
compute_movstrsi_length (insn)
     rtx insn;
{
  rtx pat = PATTERN (insn);
  int align = INTVAL (XEXP (XVECEXP (pat, 0, 6), 0));
  unsigned long n_bytes = INTVAL (XEXP (XVECEXP (pat, 0, 5), 0));
  unsigned int n_insns = 0;

  /* We can't move more than four bytes at a time because the PA
     has no longer integer move insns.  (Could use fp mem ops?)  */
  if (align > 4)
    align = 4;

  /* The basic copying loop.  */
  n_insns = 6;

  /* Residuals.  */
  if (n_bytes % (2 * align) != 0)
    {
      if ((n_bytes % (2 * align)) >= align)
	n_insns += 2;

      if ((n_bytes % align) != 0)
	n_insns += 2;
    }

  /* Lengths are expressed in bytes now; each insn is 4 bytes.  */
  return n_insns * 4;
}


char *
output_and (operands)
     rtx *operands;
{
  if (GET_CODE (operands[2]) == CONST_INT && INTVAL (operands[2]) != 0)
    {
      unsigned HOST_WIDE_INT mask = INTVAL (operands[2]);
      int ls0, ls1, ms0, p, len;

      for (ls0 = 0; ls0 < 32; ls0++)
	if ((mask & (1 << ls0)) == 0)
	  break;

      for (ls1 = ls0; ls1 < 32; ls1++)
	if ((mask & (1 << ls1)) != 0)
	  break;

      for (ms0 = ls1; ms0 < 32; ms0++)
	if ((mask & (1 << ms0)) == 0)
	  break;

      if (ms0 != 32)
	abort();

      if (ls1 == 32)
	{
	  len = ls0;

	  if (len == 0)
	    abort ();

	  operands[2] = GEN_INT (len);
	  return "extru %1,31,%2,%0";
	}
      else
	{
	  /* We could use this `depi' for the case above as well, but `depi'
	     requires one more register file access than an `extru'.  */

	  p = 31 - ls0;
	  len = ls1 - ls0;

	  operands[2] = GEN_INT (p);
	  operands[3] = GEN_INT (len);
	  return "depi 0,%2,%3,%0";
	}
    }
  else
    return "and %1,%2,%0";
}

char *
output_ior (operands)
     rtx *operands;
{
  unsigned HOST_WIDE_INT mask = INTVAL (operands[2]);
  int bs0, bs1, p, len;

  if (INTVAL (operands[2]) == 0)
    return "copy %1,%0";

  for (bs0 = 0; bs0 < 32; bs0++)
    if ((mask & (1 << bs0)) != 0)
      break;

  for (bs1 = bs0; bs1 < 32; bs1++)
    if ((mask & (1 << bs1)) == 0)
      break;

  if (bs1 != 32 && ((unsigned HOST_WIDE_INT) 1 << bs1) <= mask)
    abort();

  p = 31 - bs0;
  len = bs1 - bs0;

  operands[2] = GEN_INT (p);
  operands[3] = GEN_INT (len);
  return "depi -1,%2,%3,%0";
}

/* Output an ascii string.  */
void
output_ascii (file, p, size)
     FILE *file;
     unsigned char *p;
     int size;
{
  int i;
  int chars_output;
  unsigned char partial_output[16];	/* Max space 4 chars can occupy.   */

  /* The HP assembler can only take strings of 256 characters at one
     time.  This is a limitation on input line length, *not* the
     length of the string.  Sigh.  Even worse, it seems that the
     restriction is in number of input characters (see \xnn &
     \whatever).  So we have to do this very carefully.  */

  fputs ("\t.STRING \"", file);

  chars_output = 0;
  for (i = 0; i < size; i += 4)
    {
      int co = 0;
      int io = 0;
      for (io = 0, co = 0; io < MIN (4, size - i); io++)
	{
	  register unsigned int c = p[i + io];

	  if (c == '\"' || c == '\\')
	    partial_output[co++] = '\\';
	  if (c >= ' ' && c < 0177)
	    partial_output[co++] = c;
	  else
	    {
	      unsigned int hexd;
	      partial_output[co++] = '\\';
	      partial_output[co++] = 'x';
	      hexd =  c  / 16 - 0 + '0';
	      if (hexd > '9')
		hexd -= '9' - 'a' + 1;
	      partial_output[co++] = hexd;
	      hexd =  c % 16 - 0 + '0';
	      if (hexd > '9')
		hexd -= '9' - 'a' + 1;
	      partial_output[co++] = hexd;
	    }
	}
      if (chars_output + co > 243)
	{
	  fputs ("\"\n\t.STRING \"", file);
	  chars_output = 0;
	}
      fwrite (partial_output, 1, co, file);
      chars_output += co;
      co = 0;
    }
  fputs ("\"\n", file);
}

/* Try to rewrite floating point comparisons & branches to avoid
   useless add,tr insns.

   CHECK_NOTES is nonzero if we should examine REG_DEAD notes
   to see if FPCC is dead.  CHECK_NOTES is nonzero for the
   first attempt to remove useless add,tr insns.  It is zero
   for the second pass as reorg sometimes leaves bogus REG_DEAD
   notes lying around.

   When CHECK_NOTES is zero we can only eliminate add,tr insns
   when there's a 1:1 correspondence between fcmp and ftest/fbranch
   instructions.  */
void
remove_useless_addtr_insns (insns, check_notes)
     rtx insns;
     int check_notes;
{
  rtx insn;
  static int pass = 0;

  /* This is fairly cheap, so always run it when optimizing.  */
  if (optimize > 0)
    {
      int fcmp_count = 0;
      int fbranch_count = 0;

      /* Walk all the insns in this function looking for fcmp & fbranch
	 instructions.  Keep track of how many of each we find.  */
      insns = get_insns ();
      for (insn = insns; insn; insn = next_insn (insn))
	{
	  rtx tmp;