expr.c

GCC编译器源代码

	  if (QUEUED_INSN (y))
	    {
	      register rtx temp = gen_reg_rtx (GET_MODE (new));
	      emit_insn_before (gen_move_insn (temp, new),
				QUEUED_INSN (y));
	      return temp;
	    }
	  return new;
	}
      /* Otherwise, recursively protect the subexpressions of all
	 the kinds of rtx's that can contain a QUEUED.  */
      if (code == MEM)
	{
	  rtx tem = protect_from_queue (XEXP (x, 0), 0);
	  if (tem != XEXP (x, 0))
	    {
	      x = copy_rtx (x);
	      XEXP (x, 0) = tem;
	    }
	}
      else if (code == PLUS || code == MULT)
	{
	  rtx new0 = protect_from_queue (XEXP (x, 0), 0);
	  rtx new1 = protect_from_queue (XEXP (x, 1), 0);
	  if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
	    {
	      x = copy_rtx (x);
	      XEXP (x, 0) = new0;
	      XEXP (x, 1) = new1;
	    }
	}
      return x;
    }
  /* If the increment has not happened, use the variable itself.  */
  if (QUEUED_INSN (x) == 0)
    return QUEUED_VAR (x);
  /* If the increment has happened and a pre-increment copy exists,
     use that copy.  */
  if (QUEUED_COPY (x) != 0)
    return QUEUED_COPY (x);
  /* The increment has happened but we haven't set up a pre-increment copy.
     Set one up now, and use it.  */
  QUEUED_COPY (x) = gen_reg_rtx (GET_MODE (QUEUED_VAR (x)));
  emit_insn_before (gen_move_insn (QUEUED_COPY (x), QUEUED_VAR (x)),
		    QUEUED_INSN (x));
  return QUEUED_COPY (x);
}

/* Return nonzero if X contains a QUEUED expression:
   if it contains anything that will be altered by a queued increment.
   We handle only combinations of MEM, PLUS, MINUS and MULT operators
   since memory addresses generally contain only those.  */

static int
queued_subexp_p (x)
     rtx x;
{
  register enum rtx_code code = GET_CODE (x);
  switch (code)
    {
    case QUEUED:
      return 1;
    case MEM:
      return queued_subexp_p (XEXP (x, 0));
    case MULT:
    case PLUS:
    case MINUS:
      return (queued_subexp_p (XEXP (x, 0))
	      || queued_subexp_p (XEXP (x, 1)));
    default:
      return 0;
    }
}

/* Perform all the pending incrementations.  */

void
emit_queue ()
{
  register rtx p;
  while (p = pending_chain)
    {
      QUEUED_INSN (p) = emit_insn (QUEUED_BODY (p));
      pending_chain = QUEUED_NEXT (p);
    }
}

static void
init_queue ()
{
  if (pending_chain)
    abort ();
}

/* Copy data from FROM to TO, where the machine modes are not the same.
   Both modes may be integer, or both may be floating.
   UNSIGNEDP should be nonzero if FROM is an unsigned type.
   This causes zero-extension instead of sign-extension.  */

void
convert_move (to, from, unsignedp)
     register rtx to, from;
     int unsignedp;
{
  enum machine_mode to_mode = GET_MODE (to);
  enum machine_mode from_mode = GET_MODE (from);
  int to_real = GET_MODE_CLASS (to_mode) == MODE_FLOAT;
  int from_real = GET_MODE_CLASS (from_mode) == MODE_FLOAT;
  enum insn_code code;
  rtx libcall;

  /* rtx code for making an equivalent value.  */
  enum rtx_code equiv_code = (unsignedp ? ZERO_EXTEND : SIGN_EXTEND);

  to = protect_from_queue (to, 1);
  from = protect_from_queue (from, 0);

  if (to_real != from_real)
    abort ();

  /* If FROM is a SUBREG that indicates that we have already done at least
     the required extension, strip it.  We don't handle such SUBREGs as
     TO here.  */

  if (GET_CODE (from) == SUBREG && SUBREG_PROMOTED_VAR_P (from)
      && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (from)))
	  >= GET_MODE_SIZE (to_mode))
      && SUBREG_PROMOTED_UNSIGNED_P (from) == unsignedp)
    from = gen_lowpart (to_mode, from), from_mode = to_mode;

  if (GET_CODE (to) == SUBREG && SUBREG_PROMOTED_VAR_P (to))
    abort ();

  if (to_mode == from_mode
      || (from_mode == VOIDmode && CONSTANT_P (from)))
    {
      emit_move_insn (to, from);
      return;
    }

  if (to_real)
    {
      rtx value;

      if (GET_MODE_BITSIZE (from_mode) < GET_MODE_BITSIZE (to_mode))
	{
	  /* Try converting directly if the insn is supported.  */
	  if ((code = can_extend_p (to_mode, from_mode, 0))
	      != CODE_FOR_nothing)
	    {
	      emit_unop_insn (code, to, from, UNKNOWN);
	      return;
	    }
	}
 
#ifdef HAVE_trunchfqf2
      if (HAVE_trunchfqf2 && from_mode == HFmode && to_mode == QFmode)
	{
	  emit_unop_insn (CODE_FOR_trunchfqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_trunctqfqf2
      if (HAVE_trunctqfqf2 && from_mode == TQFmode && to_mode == QFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctqfqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncsfqf2
      if (HAVE_truncsfqf2 && from_mode == SFmode && to_mode == QFmode)
	{
	  emit_unop_insn (CODE_FOR_truncsfqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncdfqf2
      if (HAVE_truncdfqf2 && from_mode == DFmode && to_mode == QFmode)
	{
	  emit_unop_insn (CODE_FOR_truncdfqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncxfqf2
      if (HAVE_truncxfqf2 && from_mode == XFmode && to_mode == QFmode)
	{
	  emit_unop_insn (CODE_FOR_truncxfqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_trunctfqf2
      if (HAVE_trunctfqf2 && from_mode == TFmode && to_mode == QFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctfqf2, to, from, UNKNOWN);
	  return;
	}
#endif

#ifdef HAVE_trunctqfhf2
      if (HAVE_trunctqfhf2 && from_mode == TQFmode && to_mode == HFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctqfhf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncsfhf2
      if (HAVE_truncsfhf2 && from_mode == SFmode && to_mode == HFmode)
	{
	  emit_unop_insn (CODE_FOR_truncsfhf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncdfhf2
      if (HAVE_truncdfhf2 && from_mode == DFmode && to_mode == HFmode)
	{
	  emit_unop_insn (CODE_FOR_truncdfhf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncxfhf2
      if (HAVE_truncxfhf2 && from_mode == XFmode && to_mode == HFmode)
	{
	  emit_unop_insn (CODE_FOR_truncxfhf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_trunctfhf2
      if (HAVE_trunctfhf2 && from_mode == TFmode && to_mode == HFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctfhf2, to, from, UNKNOWN);
	  return;
	}
#endif

#ifdef HAVE_truncsftqf2
      if (HAVE_truncsftqf2 && from_mode == SFmode && to_mode == TQFmode)
	{
	  emit_unop_insn (CODE_FOR_truncsftqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncdftqf2
      if (HAVE_truncdftqf2 && from_mode == DFmode && to_mode == TQFmode)
	{
	  emit_unop_insn (CODE_FOR_truncdftqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncxftqf2
      if (HAVE_truncxftqf2 && from_mode == XFmode && to_mode == TQFmode)
	{
	  emit_unop_insn (CODE_FOR_truncxftqf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_trunctftqf2
      if (HAVE_trunctftqf2 && from_mode == TFmode && to_mode == TQFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctftqf2, to, from, UNKNOWN);
	  return;
	}
#endif

#ifdef HAVE_truncdfsf2
      if (HAVE_truncdfsf2 && from_mode == DFmode && to_mode == SFmode)
	{
	  emit_unop_insn (CODE_FOR_truncdfsf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncxfsf2
      if (HAVE_truncxfsf2 && from_mode == XFmode && to_mode == SFmode)
	{
	  emit_unop_insn (CODE_FOR_truncxfsf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_trunctfsf2
      if (HAVE_trunctfsf2 && from_mode == TFmode && to_mode == SFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctfsf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_truncxfdf2
      if (HAVE_truncxfdf2 && from_mode == XFmode && to_mode == DFmode)
	{
	  emit_unop_insn (CODE_FOR_truncxfdf2, to, from, UNKNOWN);
	  return;
	}
#endif
#ifdef HAVE_trunctfdf2
      if (HAVE_trunctfdf2 && from_mode == TFmode && to_mode == DFmode)
	{
	  emit_unop_insn (CODE_FOR_trunctfdf2, to, from, UNKNOWN);
	  return;
	}
#endif

      libcall = (rtx) 0;
      switch (from_mode)
	{
	case SFmode:
	  switch (to_mode)
	    {
	    case DFmode:
	      libcall = extendsfdf2_libfunc;
	      break;

	    case XFmode:
	      libcall = extendsfxf2_libfunc;
	      break;

	    case TFmode:
	      libcall = extendsftf2_libfunc;
	      break;
	      
	    default:
	      break;
	    }
	  break;

	case DFmode:
	  switch (to_mode)
	    {
	    case SFmode:
	      libcall = truncdfsf2_libfunc;
	      break;

	    case XFmode:
	      libcall = extenddfxf2_libfunc;
	      break;

	    case TFmode:
	      libcall = extenddftf2_libfunc;
	      break;
	      
	    default:
	      break;
	    }
	  break;

	case XFmode:
	  switch (to_mode)
	    {
	    case SFmode:
	      libcall = truncxfsf2_libfunc;
	      break;

	    case DFmode:
	      libcall = truncxfdf2_libfunc;
	      break;
	      
	    default:
	      break;
	    }
	  break;

	case TFmode:
	  switch (to_mode)
	    {
	    case SFmode:
	      libcall = trunctfsf2_libfunc;
	      break;

	    case DFmode:
	      libcall = trunctfdf2_libfunc;
	      break;
	      
	    default:
	      break;
	    }
	  break;
	  
	default:
	  break;
	}

      if (libcall == (rtx) 0)
	/* This conversion is not implemented yet.  */
	abort ();

      value = emit_library_call_value (libcall, NULL_RTX, 1, to_mode,
				       1, from, from_mode);
      emit_move_insn (to, value);
      return;
    }

  /* Now both modes are integers.  */

  /* Handle expanding beyond a word.  */
  if (GET_MODE_BITSIZE (from_mode) < GET_MODE_BITSIZE (to_mode)
      && GET_MODE_BITSIZE (to_mode) > BITS_PER_WORD)
    {
      rtx insns;
      rtx lowpart;
      rtx fill_value;
      rtx lowfrom;
      int i;
      enum machine_mode lowpart_mode;
      int nwords = CEIL (GET_MODE_SIZE (to_mode), UNITS_PER_WORD);

      /* Try converting directly if the insn is supported.  */
      if ((code = can_extend_p (to_mode, from_mode, unsignedp))
	  != CODE_FOR_nothing)
	{
	  /* If FROM is a SUBREG, put it into a register.  Do this
	     so that we always generate the same set of insns for
	     better cse'ing; if an intermediate assignment occurred,
	     we won't be doing the operation directly on the SUBREG.  */
	  if (optimize > 0 && GET_CODE (from) == SUBREG)
	    from = force_reg (from_mode, from);
	  emit_unop_insn (code, to, from, equiv_code);
	  return;
	}
      /* Next, try converting via full word.  */
      else if (GET_MODE_BITSIZE (from_mode) < BITS_PER_WORD
	       && ((code = can_extend_p (to_mode, word_mode, unsignedp))
		   != CODE_FOR_nothing))
	{
	  if (GET_CODE (to) == REG)
	    emit_insn (gen_rtx (CLOBBER, VOIDmode, to));
	  convert_move (gen_lowpart (word_mode, to), from, unsignedp);
	  emit_unop_insn (code, to,
			  gen_lowpart (word_mode, to), equiv_code);
	  return;
	}

      /* No special multiword conversion insn; do it by hand.  */
      start_sequence ();

      /* Since we will turn this into a no conflict block, we must ensure
	 that the source does not overlap the target.  */

      if (reg_overlap_mentioned_p (to, from))
	from = force_reg (from_mode, from);

      /* Get a copy of FROM widened to a word, if necessary.  */
      if (GET_MODE_BITSIZE (from_mode) < BITS_PER_WORD)
	lowpart_mode = word_mode;
      else
	lowpart_mode = from_mode;

      lowfrom = convert_to_mode (lowpart_mode, from, unsignedp);

      lowpart = gen_lowpart (lowpart_mode, to);
      emit_move_insn (lowpart, lowfrom);

      /* Compute the value to put in each remaining word.  */
      if (unsignedp)
	fill_value = const0_rtx;
      else
	{
#ifdef HAVE_slt
	  if (HAVE_slt
	      && insn_operand_mode[(int) CODE_FOR_slt][0] == word_mode
	      && STORE_FLAG_VALUE == -1)
	    {
	      emit_cmp_insn (lowfrom, const0_rtx, NE, NULL_RTX,
			     lowpart_mode, 0, 0);
	      fill_value = gen_reg_rtx (word_mode);
	      emit_insn (gen_slt (fill_value));
	    }
	  else
#endif
	    {
	      fill_value
		= expand_shift (RSHIFT_EXPR, lowpart_mode, lowfrom,