C++ GET_RTX_LENGTH函数代码示例

PyObject *
PyGccRtl_get_operands(struct PyGccRtl *self, void *closure)
{
    const int length = GET_RTX_LENGTH (GET_CODE (self->insn.inner));
    PyObject *result;
    int i;
    const char *format_ptr;

    result = PyTuple_New(length);
    if (!result) {
        return NULL;
    }

    format_ptr = GET_RTX_FORMAT (GET_CODE (self->insn.inner));
    for (i = 0; i < length; i++) {
        PyObject *item = get_operand_as_object(self->insn.inner, i, *format_ptr++);
        if (!item) {
            Py_DECREF(result);
            return NULL;
        }
        PyTuple_SET_ITEM(result, i, item);
    }

    return result;
}

/* Return TRUE if X references a SYMBOL_REF or LABEL_REF whose symbol
   isn't protected by a PIC unspec.  */
int
nonpic_symbol_mentioned_p (rtx x)
{
  const char *fmt;
  int i;

  if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF
      || GET_CODE (x) == PC)
    return 1;

  /* We don't want to look into the possible MEM location of a
     CONST_DOUBLE, since we're not going to use it, in general.  */
  if (GET_CODE (x) == CONST_DOUBLE)
    return 0;

  if (GET_CODE (x) == UNSPEC)
    return 0;

  fmt = GET_RTX_FORMAT (GET_CODE (x));
  for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'E')
	{
	  int j;

	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
	    if (nonpic_symbol_mentioned_p (XVECEXP (x, i, j)))
	      return 1;
	}
      else if (fmt[i] == 'e' && nonpic_symbol_mentioned_p (XEXP (x, i)))
	return 1;
    }

  return 0;
}

static void
purge_mem_unchanging_flag (rtx x)
{
  RTX_CODE code;
  int i, j;
  const char *fmt;

  if (x == NULL_RTX)
    return;

  code = GET_CODE (x);

  if (code == MEM)
    {
      if (RTX_UNCHANGING_P (x)
	  && (XEXP (x, 0) == current_function_internal_arg_pointer
	      || (GET_CODE (XEXP (x, 0)) == PLUS
		  && XEXP (XEXP (x, 0), 0) ==
		     current_function_internal_arg_pointer
		  && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)))
	RTX_UNCHANGING_P (x) = 0;
      return;
    }

  /* Scan all subexpressions.  */
  fmt = GET_RTX_FORMAT (code);
  for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
    {
      if (*fmt == 'e')
	purge_mem_unchanging_flag (XEXP (x, i));
      else if (*fmt == 'E')
	for (j = 0; j < XVECLEN (x, i); j++)
	  purge_mem_unchanging_flag (XVECEXP (x, i, j));
    }
}

static void
max_operand_1 (rtx x)
{
  RTX_CODE code;
  int i;
  int len;
  const char *fmt;

  if (x == 0)
    return;

  code = GET_CODE (x);

  if (code == MATCH_OPERAND || code == MATCH_OPERATOR
      || code == MATCH_PARALLEL)
    max_opno = MAX (max_opno, XINT (x, 0));

  fmt = GET_RTX_FORMAT (code);
  len = GET_RTX_LENGTH (code);
  for (i = 0; i < len; i++)
    {
      if (fmt[i] == 'e' || fmt[i] == 'u')
	max_operand_1 (XEXP (x, i));
      else if (fmt[i] == 'E')
	{
	  int j;
	  for (j = 0; j < XVECLEN (x, i); j++)
	    max_operand_1 (XVECEXP (x, i, j));
	}
    }
}

/* Return true if X contains memory or some UNSPEC.  We can not just
   check insn operands as memory or unspec might be not an operand
   itself but contain an operand.  Insn with memory access is not
   profitable for rematerialization.  Rematerialization of UNSPEC
   might result in wrong code generation as the UNPEC effect is
   unknown (e.g. generating a label).  */
static bool
bad_for_rematerialization_p (rtx x)
{
  int i, j;
  const char *fmt;
  enum rtx_code code;

  if (MEM_P (x) || GET_CODE (x) == UNSPEC || GET_CODE (x) == UNSPEC_VOLATILE)
    return true;
  code = GET_CODE (x);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'e')
	{
	  if (bad_for_rematerialization_p (XEXP (x, i)))
	    return true;
	}
      else if (fmt[i] == 'E')
	{
	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
	    if (bad_for_rematerialization_p (XVECEXP (x, i, j)))
	      return true;
	}
    }
  return false;
}

void
rtl_check_failed_bounds (const_rtx r, int n, const char *file, int line,
			 const char *func)
{
  internal_error
    ("RTL check: access of elt %d of '%s' with last elt %d in %s, at %s:%d",
     n, GET_RTX_NAME (GET_CODE (r)), GET_RTX_LENGTH (GET_CODE (r)) - 1,
     func, trim_filename (file), line);
}

static void
collect_insn_data (rtx pattern, int *palt, int *pmax)
{
  const char *fmt;
  enum rtx_code code;
  int i, j, len;

  code = GET_CODE (pattern);
  switch (code)
    {
    case MATCH_OPERAND:
      i = n_alternatives (XSTR (pattern, 2));
      *palt = (i > *palt ? i : *palt);
      /* Fall through.  */

    case MATCH_OPERATOR:
    case MATCH_SCRATCH:
    case MATCH_PARALLEL:
    case MATCH_INSN:
      i = XINT (pattern, 0);
      if (i > *pmax)
	*pmax = i;
      break;

    default:
      break;
    }

  fmt = GET_RTX_FORMAT (code);
  len = GET_RTX_LENGTH (code);
  for (i = 0; i < len; i++)
    {
      switch (fmt[i])
	{
	case 'e': case 'u':
	  collect_insn_data (XEXP (pattern, i), palt, pmax);
	  break;

	case 'V':
	  if (XVEC (pattern, i) == NULL)
	    break;
	  /* Fall through.  */
	case 'E':
	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
	    collect_insn_data (XVECEXP (pattern, i, j), palt, pmax);
	  break;

	case 'i': case 'w': case '0': case 's': case 'S': case 'T':
	  break;

	default:
	  abort ();
	}
    }
}

/* Process MEMs in SET_DEST destinations.  We must not process this together
   with REG SET_DESTs, but must do it separately, lest when we see
   [(set (reg:SI foo) (bar))
    (set (mem:SI (reg:SI foo) (baz)))]
   struct_equiv_block_eq could get confused to assume that (reg:SI foo)
   is not live before this instruction.  */
static bool
set_dest_addr_equiv_p (rtx x, rtx y, struct equiv_info *info)
{
  enum rtx_code code = GET_CODE (x);
  int length;
  const char *format;
  int i;

  if (code != GET_CODE (y))
    return false;
  if (code == MEM)
    return rtx_equiv_p (&XEXP (x, 0), XEXP (y, 0), 1, info);

  /* Process subexpressions.  */
  length = GET_RTX_LENGTH (code);
  format = GET_RTX_FORMAT (code);

  for (i = 0; i < length; ++i)
    {
      switch (format[i])
	{
	case 'V':
	case 'E':
	  if (XVECLEN (x, i) != XVECLEN (y, i))
	    return false;
	  if (XVEC (x, i) != 0)
	    {
	      int j;
	      for (j = 0; j < XVECLEN (x, i); ++j)
		{
		  if (! set_dest_addr_equiv_p (XVECEXP (x, i, j),
					       XVECEXP (y, i, j), info))
		    return false;
		}
	    }
	  break;
	case 'e':
	  if (! set_dest_addr_equiv_p (XEXP (x, i), XEXP (y, i), info))
	    return false;
	  break;
	default:
	  break;
	}
    }
  return true;
}

/* Change pseudos in *LOC on their coalescing group
   representatives.  */
static bool
substitute (rtx *loc)
{
  int i, regno;
  const char *fmt;
  enum rtx_code code;
  bool res;

  if (*loc == NULL_RTX)
    return false;
  code = GET_CODE (*loc);
  if (code == REG)
    {
      regno = REGNO (*loc);
      if (regno < FIRST_PSEUDO_REGISTER
	  || first_coalesced_pseudo[regno] == regno)
	return false;
      *loc = regno_reg_rtx[first_coalesced_pseudo[regno]];
      return true;
    }

  res = false;
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'e')
	{
	  if (substitute (&XEXP (*loc, i)))
	    res = true;
	}
      else if (fmt[i] == 'E')
	{
	  int j;

	  for (j = XVECLEN (*loc, i) - 1; j >= 0; j--)
	    if (substitute (&XVECEXP (*loc, i, j)))
	      res = true;
	}
    }
  return res;
}

int
references_value_p (const_rtx x, int only_useless)
{
  const enum rtx_code code = GET_CODE (x);
  const char *fmt = GET_RTX_FORMAT (code);
  int i, j;

  if (GET_CODE (x) == VALUE
      && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0))
    return 1;

  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless))
	return 1;
      else if (fmt[i] == 'E')
	for (j = 0; j < XVECLEN (x, i); j++)
	  if (references_value_p (XVECEXP (x, i, j), only_useless))
	    return 1;
    }

  return 0;
}

static int
uses_addressof (rtx x)
{
  RTX_CODE code;
  int i, j;
  const char *fmt;

  if (x == NULL_RTX)
    return 0;

  code = GET_CODE (x);

  if (code == ADDRESSOF || x == current_function_internal_arg_pointer)
    return 1;

  if (code == MEM)
    return 0;

  /* Scan all subexpressions.  */
  fmt = GET_RTX_FORMAT (code);
  for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
    {
      if (*fmt == 'e')
	{
	  if (uses_addressof (XEXP (x, i)))
	    return 1;
	}
      else if (*fmt == 'E')
	{
	  for (j = 0; j < XVECLEN (x, i); j++)
	    if (uses_addressof (XVECEXP (x, i, j)))
	      return 1;
	}
    }
  return 0;
}

//.........这里部分代码省略.........
      else if (REG_P (XEXP (x, 0))
	       && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER)
	{
	  /* If we modify the source of an elimination rule, disable
	     it.  Do the same if it is the destination and not the
	     hard frame register.  */
	  for (ep = reg_eliminate;
	       ep < &reg_eliminate[NUM_ELIMINABLE_REGS];
	       ep++)
	    if (ep->from_rtx == XEXP (x, 0)
		|| (ep->to_rtx == XEXP (x, 0)
		    && ep->to_rtx != hard_frame_pointer_rtx))
	      setup_can_eliminate (ep, false);
	}
      return;

    case USE:
      if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)
	/* If using a hard register that is the source of an eliminate
	   we still think can be performed, note it cannot be
	   performed since we don't know how this hard register is
	   used.  */
	for (ep = reg_eliminate;
	     ep < &reg_eliminate[NUM_ELIMINABLE_REGS];
	     ep++)
	  if (ep->from_rtx == XEXP (x, 0)
	      && ep->to_rtx != hard_frame_pointer_rtx)
	    setup_can_eliminate (ep, false);
      return;

    case CLOBBER:
      if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)
	/* If clobbering a hard register that is the replacement
	   register for an elimination we still think can be
	   performed, note that it cannot be performed.	 Otherwise, we
	   need not be concerned about it.  */
	for (ep = reg_eliminate;
	     ep < &reg_eliminate[NUM_ELIMINABLE_REGS];
	     ep++)
	  if (ep->to_rtx == XEXP (x, 0)
	      && ep->to_rtx != hard_frame_pointer_rtx)
	    setup_can_eliminate (ep, false);
      return;

    case SET:
      if (SET_DEST (x) == stack_pointer_rtx
	  && GET_CODE (SET_SRC (x)) == PLUS
	  && XEXP (SET_SRC (x), 0) == SET_DEST (x)
	  && CONST_INT_P (XEXP (SET_SRC (x), 1)))
	{
	  curr_sp_change += INTVAL (XEXP (SET_SRC (x), 1));
	  return;
	}
      if (! REG_P (SET_DEST (x))
	  || REGNO (SET_DEST (x)) >= FIRST_PSEUDO_REGISTER)
	mark_not_eliminable (SET_DEST (x), mem_mode);
      else
	{
	  /* See if this is setting the replacement hard register for
	     an elimination.
	     
	     If DEST is the hard frame pointer, we do nothing because
	     we assume that all assignments to the frame pointer are
	     for non-local gotos and are being done at a time when
	     they are valid and do not disturb anything else.  Some
	     machines want to eliminate a fake argument pointer (or
	     even a fake frame pointer) with either the real frame
	     pointer or the stack pointer.  Assignments to the hard
	     frame pointer must not prevent this elimination.  */
	  for (ep = reg_eliminate;
	       ep < &reg_eliminate[NUM_ELIMINABLE_REGS];
	       ep++)
	    if (ep->to_rtx == SET_DEST (x)
		&& SET_DEST (x) != hard_frame_pointer_rtx)
	      setup_can_eliminate (ep, false);
	}
      
      mark_not_eliminable (SET_SRC (x), mem_mode);
      return;

    case MEM:
      /* Our only special processing is to pass the mode of the MEM to
	 our recursive call.  */
      mark_not_eliminable (XEXP (x, 0), GET_MODE (x));
      return;

    default:
      break;
    }

  fmt = GET_RTX_FORMAT (code);
  for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
    {
      if (*fmt == 'e')
	mark_not_eliminable (XEXP (x, i), mem_mode);
      else if (*fmt == 'E')
	for (j = 0; j < XVECLEN (x, i); j++)
	  mark_not_eliminable (XVECEXP (x, i, j), mem_mode);
    }
}

/* Recursive hash function for RTL X.  */
static hashval_t
rtx_hash (rtx x)
{
  int i, j;
  enum rtx_code code;
  const char *fmt;
  hashval_t val = 0;

  if (x == 0)
    return val;

  code = GET_CODE (x);
  val += (int) code + 4095;

  /* Some RTL can be compared nonrecursively.  */
  switch (code)
    {
    case REG:
      return val + REGNO (x);

    case LABEL_REF:
      return iterative_hash_object (XEXP (x, 0), val);

    case SYMBOL_REF:
      return iterative_hash_object (XSTR (x, 0), val);

    case SCRATCH:
    case CONST_DOUBLE:
    case CONST_INT:
    case CONST_VECTOR:
      return val;

    default:
      break;
    }

  /* Hash the elements.  */
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      switch (fmt[i])
	{
	case 'w':
	  val += XWINT (x, i);
	  break;

	case 'n':
	case 'i':
	  val += XINT (x, i);
	  break;

	case 'V':
	case 'E':
	  val += XVECLEN (x, i);

	  for (j = 0; j < XVECLEN (x, i); j++)
	    val += rtx_hash (XVECEXP (x, i, j));
	  break;

	case 'e':
	  val += rtx_hash (XEXP (x, i));
	  break;

	case 'S':
	case 's':
	  val += htab_hash_string (XSTR (x, i));
	  break;

	case 'u':
	case '0':
	case 't':
	  break;

	  /* It is believed that rtx's at this level will never
	     contain anything but integers and other rtx's, except for
	     within LABEL_REFs and SYMBOL_REFs.  */
	default:
	  abort ();
	}
    }
  return val;
}

hashval_t
iterative_hash_rtx (const_rtx x, hashval_t hash)
{
  enum rtx_code code;
  enum machine_mode mode;
  int i, j;
  const char *fmt;

  if (x == NULL_RTX)
    return hash;
  code = GET_CODE (x);
  hash = iterative_hash_object (code, hash);
  mode = GET_MODE (x);
  hash = iterative_hash_object (mode, hash);
  switch (code)
    {
    case REG:
      i = REGNO (x);
      return iterative_hash_object (i, hash);
    case CONST_INT:
      return iterative_hash_object (INTVAL (x), hash);
    case SYMBOL_REF:
      if (XSTR (x, 0))
	return iterative_hash (XSTR (x, 0), strlen (XSTR (x, 0)) + 1,
			       hash);
      return hash;
    case LABEL_REF:
    case DEBUG_EXPR:
    case VALUE:
    case SCRATCH:
    case CONST_DOUBLE:
    case CONST_FIXED:
    case DEBUG_IMPLICIT_PTR:
    case DEBUG_PARAMETER_REF:
      return hash;
    default:
      break;
    }

  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    switch (fmt[i])
      {
      case 'w':
	hash = iterative_hash_object (XWINT (x, i), hash);
	break;
      case 'n':
      case 'i':
	hash = iterative_hash_object (XINT (x, i), hash);
	break;
      case 'V':
      case 'E':
	j = XVECLEN (x, i);
	hash = iterative_hash_object (j, hash);
	for (j = 0; j < XVECLEN (x, i); j++)
	  hash = iterative_hash_rtx (XVECEXP (x, i, j), hash);
	break;
      case 'e':
	hash = iterative_hash_rtx (XEXP (x, i), hash);
	break;
      case 'S':
      case 's':
	if (XSTR (x, i))
	  hash = iterative_hash (XSTR (x, 0), strlen (XSTR (x, 0)) + 1,
				 hash);
	break;
      default:
	break;
      }
  return hash;
}

int
rtx_equal_p (const_rtx x, const_rtx y)
{
  int i;
  int j;
  enum rtx_code code;
  const char *fmt;

  if (x == y)
    return 1;
  if (x == 0 || y == 0)
    return 0;

  code = GET_CODE (x);
  /* Rtx's of different codes cannot be equal.  */
  if (code != GET_CODE (y))
    return 0;

  /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
     (REG:SI x) and (REG:HI x) are NOT equivalent.  */

  if (GET_MODE (x) != GET_MODE (y))
    return 0;

  /* MEMs referring to different address space are not equivalent.  */
  if (code == MEM && MEM_ADDR_SPACE (x) != MEM_ADDR_SPACE (y))
    return 0;

  /* Some RTL can be compared nonrecursively.  */
  switch (code)
    {
    case REG:
      return (REGNO (x) == REGNO (y));

    case LABEL_REF:
      return XEXP (x, 0) == XEXP (y, 0);

    case SYMBOL_REF:
      return XSTR (x, 0) == XSTR (y, 0);

    case DEBUG_EXPR:
    case VALUE:
    case SCRATCH:
    case CONST_DOUBLE:
    case CONST_INT:
    case CONST_FIXED:
      return 0;

    case DEBUG_IMPLICIT_PTR:
      return DEBUG_IMPLICIT_PTR_DECL (x)
	     == DEBUG_IMPLICIT_PTR_DECL (y);

    case DEBUG_PARAMETER_REF:
      return DEBUG_PARAMETER_REF_DECL (x)
	     == DEBUG_PARAMETER_REF_DECL (y);

    case ENTRY_VALUE:
      return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y));

    default:
      break;
    }

  /* Compare the elements.  If any pair of corresponding elements
     fail to match, return 0 for the whole thing.  */

  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      switch (fmt[i])
	{
	case 'w':
	  if (XWINT (x, i) != XWINT (y, i))
	    return 0;
	  break;

	case 'n':
	case 'i':
	  if (XINT (x, i) != XINT (y, i))
	    {
#ifndef GENERATOR_FILE
	      if (((code == ASM_OPERANDS && i == 6)
		   || (code == ASM_INPUT && i == 1))
		  && locator_eq (XINT (x, i), XINT (y, i)))
		break;
#endif
	      return 0;
	    }
	  break;

	case 'V':
	case 'E':
	  /* Two vectors must have the same length.  */
	  if (XVECLEN (x, i) != XVECLEN (y, i))
	    return 0;

	  /* And the corresponding elements must match.  */
	  for (j = 0; j < XVECLEN (x, i); j++)
	    if (rtx_equal_p (XVECEXP (x, i, j),  XVECEXP (y, i, j)) == 0)
	      return 0;
//.........这里部分代码省略.........