extern int check_use_sfunc_addr (rtx, rtx);

/* INSN is an sfunc; return the rtx that describes the address used.  */

static rtx

extract_sfunc_addr (rtx insn)

{

  rtx pattern, part = NULL_RTX;

  int len, i;

  pattern = PATTERN (insn);

  len = XVECLEN (pattern, 0);

  for (i = 0; i < len; i++)

    {

      part = XVECEXP (pattern, 0, i);

      if (GET_CODE (part) == USE && GET_MODE (XEXP (part, 0)) == Pmode

	  && GENERAL_REGISTER_P (true_regnum (XEXP (part, 0))))

	return XEXP (part, 0);

    }

  if (GET_CODE (XVECEXP (pattern, 0, 0)) == UNSPEC_VOLATILE)

    return XVECEXP (XVECEXP (pattern, 0, 0), 0, 1);

  abort ();

}

/* Verify that the register in use_sfunc_addr still agrees with the address

   used in the sfunc.  This prevents fill_slots_from_thread from changing

   use_sfunc_addr.

   INSN is the use_sfunc_addr instruction, and REG is the register it

   guards.  */

int

check_use_sfunc_addr (rtx insn, rtx reg)

{

  /* Search for the sfunc.  It should really come right after INSN.  */

  while ((insn = NEXT_INSN (insn)))

    {

      if (GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == JUMP_INSN)

	break;

      if (! INSN_P (insn))

	continue;

      if (GET_CODE (PATTERN (insn)) == SEQUENCE)

	insn = XVECEXP (PATTERN (insn), 0, 0);

      if (GET_CODE (PATTERN (insn)) != PARALLEL

	  || get_attr_type (insn) != TYPE_SFUNC)

	continue;

      return rtx_equal_p (extract_sfunc_addr (insn), reg);

    }

  abort ();

}