(root)/
gcc-13.2.0/
gcc/
real.h
       1  /* Definitions of floating-point access for GNU compiler.
       2     Copyright (C) 1989-2023 Free Software Foundation, Inc.
       3  
       4     This file is part of GCC.
       5  
       6     GCC is free software; you can redistribute it and/or modify it under
       7     the terms of the GNU General Public License as published by the Free
       8     Software Foundation; either version 3, or (at your option) any later
       9     version.
      10  
      11     GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      12     WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      14     for more details.
      15  
      16     You should have received a copy of the GNU General Public License
      17     along with GCC; see the file COPYING3.  If not see
      18     <http://www.gnu.org/licenses/>.  */
      19  
      20  #ifndef GCC_REAL_H
      21  #define GCC_REAL_H
      22  
      23  /* An expanded form of the represented number.  */
      24  
      25  /* Enumerate the special cases of numbers that we encounter.  */
      26  enum real_value_class {
      27    rvc_zero,
      28    rvc_normal,
      29    rvc_inf,
      30    rvc_nan
      31  };
      32  
      33  #define SIGNIFICAND_BITS	(128 + HOST_BITS_PER_LONG)
      34  #define EXP_BITS		(32 - 6)
      35  #define MAX_EXP			((1 << (EXP_BITS - 1)) - 1)
      36  #define SIGSZ			(SIGNIFICAND_BITS / HOST_BITS_PER_LONG)
      37  #define SIG_MSB			((unsigned long)1 << (HOST_BITS_PER_LONG - 1))
      38  
      39  struct GTY(()) real_value {
      40    /* Use the same underlying type for all bit-fields, so as to make
      41       sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will
      42       be miscomputed.  */
      43    unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2;
      44    /* 1 if number is decimal floating point.  */
      45    unsigned int decimal : 1;
      46    /* 1 if number is negative.  */
      47    unsigned int sign : 1;
      48    /* 1 if number is signalling.  */
      49    unsigned int signalling : 1;
      50    /* 1 if number is canonical
      51    All are generally used for handling cases in real.cc.  */
      52    unsigned int canonical : 1;
      53    /* unbiased exponent of the number.  */
      54    unsigned int uexp : EXP_BITS;
      55    /* significand of the number.  */
      56    unsigned long sig[SIGSZ];
      57  };
      58  
      59  #define REAL_EXP(REAL) \
      60    ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \
      61     - (1 << (EXP_BITS - 1)))
      62  #define SET_REAL_EXP(REAL, EXP) \
      63    ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1)))
      64  
      65  /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it
      66     needs to be a macro.  We do need to continue to have a structure tag
      67     so that other headers can forward declare it.  */
      68  #define REAL_VALUE_TYPE struct real_value
      69  
      70  /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in
      71     consecutive "w" slots.  Moreover, we've got to compute the number of "w"
      72     slots at preprocessor time, which means we can't use sizeof.  Guess.  */
      73  
      74  #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32)
      75  #define REAL_WIDTH \
      76    (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
      77     + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
      78  
      79  /* Verify the guess.  */
      80  extern char test_real_width
      81    [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
      82  
      83  /* Calculate the format for CONST_DOUBLE.  We need as many slots as
      84     are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
      85     as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).
      86  
      87     A number of places assume that there are always at least two 'w'
      88     slots in a CONST_DOUBLE, so we provide them even if one would suffice.  */
      89  
      90  #if REAL_WIDTH == 1
      91  # define CONST_DOUBLE_FORMAT	 "ww"
      92  #else
      93  # if REAL_WIDTH == 2
      94  #  define CONST_DOUBLE_FORMAT	 "ww"
      95  # else
      96  #  if REAL_WIDTH == 3
      97  #   define CONST_DOUBLE_FORMAT	 "www"
      98  #  else
      99  #   if REAL_WIDTH == 4
     100  #    define CONST_DOUBLE_FORMAT	 "wwww"
     101  #   else
     102  #    if REAL_WIDTH == 5
     103  #     define CONST_DOUBLE_FORMAT "wwwww"
     104  #    else
     105  #     if REAL_WIDTH == 6
     106  #      define CONST_DOUBLE_FORMAT "wwwwww"
     107  #     else
     108         #error "REAL_WIDTH > 6 not supported"
     109  #     endif
     110  #    endif
     111  #   endif
     112  #  endif
     113  # endif
     114  #endif
     115  
     116  
     117  /* Describes the properties of the specific target format in use.  */
     118  struct real_format
     119  {
     120    /* Move to and from the target bytes.  */
     121    void (*encode) (const struct real_format *, long *,
     122  		  const REAL_VALUE_TYPE *);
     123    void (*decode) (const struct real_format *, REAL_VALUE_TYPE *,
     124  		  const long *);
     125  
     126    /* The radix of the exponent and digits of the significand.  */
     127    int b;
     128  
     129    /* Size of the significand in digits of radix B.  */
     130    int p;
     131  
     132    /* Size of the significant of a NaN, in digits of radix B.  */
     133    int pnan;
     134  
     135    /* The minimum negative integer, x, such that b**(x-1) is normalized.  */
     136    int emin;
     137  
     138    /* The maximum integer, x, such that b**(x-1) is representable.  */
     139    int emax;
     140  
     141    /* The bit position of the sign bit, for determining whether a value
     142       is positive/negative, or -1 for a complex encoding.  */
     143    int signbit_ro;
     144  
     145    /* The bit position of the sign bit, for changing the sign of a number,
     146       or -1 for a complex encoding.  */
     147    int signbit_rw;
     148  
     149    /* If this is an IEEE interchange format, the number of bits in the
     150       format; otherwise, if it is an IEEE extended format, one more
     151       than the greatest number of bits in an interchange format it
     152       extends; otherwise 0.  Formats need not follow the IEEE 754-2008
     153       recommended practice regarding how signaling NaNs are identified,
     154       and may vary in the choice of default NaN, but must follow other
     155       IEEE practice regarding having NaNs, infinities and subnormal
     156       values, and the relation of minimum and maximum exponents, and,
     157       for interchange formats, the details of the encoding.  */
     158    int ieee_bits;
     159  
     160    /* Default rounding mode for operations on this format.  */
     161    bool round_towards_zero;
     162    bool has_sign_dependent_rounding;
     163  
     164    /* Properties of the format.  */
     165    bool has_nans;
     166    bool has_inf;
     167    bool has_denorm;
     168    bool has_signed_zero;
     169    bool qnan_msb_set;
     170    bool canonical_nan_lsbs_set;
     171    const char *name;
     172  };
     173  
     174  
     175  /* The target format used for each floating point mode.
     176     Float modes are followed by decimal float modes, with entries for
     177     float modes indexed by (MODE - first float mode), and entries for
     178     decimal float modes indexed by (MODE - first decimal float mode) +
     179     the number of float modes.  */
     180  extern const struct real_format *
     181    real_format_for_mode[NUM_MODE_FLOAT + NUM_MODE_DECIMAL_FLOAT];
     182  
     183  #define REAL_MODE_FORMAT(MODE)						\
     184    (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE)			\
     185  			? (((MODE) - MIN_MODE_DECIMAL_FLOAT)		\
     186  			   + NUM_MODE_FLOAT)				\
     187  			: GET_MODE_CLASS (MODE) == MODE_FLOAT		\
     188  			? ((MODE) - MIN_MODE_FLOAT)			\
     189  			: (gcc_unreachable (), 0)])
     190  
     191  #define FLOAT_MODE_FORMAT(MODE) \
     192    (REAL_MODE_FORMAT (as_a <scalar_float_mode> (GET_MODE_INNER (MODE))))
     193  
     194  /* The following macro determines whether the floating point format is
     195     composite, i.e. may contain non-consecutive mantissa bits, in which
     196     case compile-time FP overflow may not model run-time overflow.  */
     197  #define MODE_COMPOSITE_P(MODE) \
     198    (FLOAT_MODE_P (MODE) \
     199     && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p)
     200  
     201  /* Accessor macros for format properties.  */
     202  #define MODE_HAS_NANS(MODE) \
     203    (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans)
     204  #define MODE_HAS_INFINITIES(MODE) \
     205    (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf)
     206  #define MODE_HAS_SIGNED_ZEROS(MODE) \
     207    (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero)
     208  #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \
     209    (FLOAT_MODE_P (MODE) \
     210     && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding)
     211  
     212  /* This class allows functions in this file to accept a floating-point
     213     format as either a mode or an explicit real_format pointer.  In the
     214     former case the mode must be VOIDmode (which means "no particular
     215     format") or must satisfy SCALAR_FLOAT_MODE_P.  */
     216  class format_helper
     217  {
     218  public:
     219    format_helper (const real_format *format) : m_format (format) {}
     220    template<typename T> format_helper (const T &);
     221    const real_format *operator-> () const { return m_format; }
     222    operator const real_format *() const { return m_format; }
     223  
     224    bool decimal_p () const { return m_format && m_format->b == 10; }
     225    bool can_represent_integral_type_p (tree type) const;
     226  
     227  private:
     228    const real_format *m_format;
     229  };
     230  
     231  template<typename T>
     232  inline format_helper::format_helper (const T &m)
     233    : m_format (m == VOIDmode ? 0 : REAL_MODE_FORMAT (m))
     234  {}
     235  
     236  /* Declare functions in real.cc.  */
     237  
     238  /* True if the given mode has a NaN representation and the treatment of
     239     NaN operands is important.  Certain optimizations, such as folding
     240     x * 0 into 0, are not correct for NaN operands, and are normally
     241     disabled for modes with NaNs.  The user can ask for them to be
     242     done anyway using the -funsafe-math-optimizations switch.  */
     243  extern bool HONOR_NANS (machine_mode);
     244  extern bool HONOR_NANS (const_tree);
     245  extern bool HONOR_NANS (const_rtx);
     246  
     247  /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
     248  extern bool HONOR_SNANS (machine_mode);
     249  extern bool HONOR_SNANS (const_tree);
     250  extern bool HONOR_SNANS (const_rtx);
     251  
     252  /* As for HONOR_NANS, but true if the mode can represent infinity and
     253     the treatment of infinite values is important.  */
     254  extern bool HONOR_INFINITIES (machine_mode);
     255  extern bool HONOR_INFINITIES (const_tree);
     256  extern bool HONOR_INFINITIES (const_rtx);
     257  
     258  /* Like HONOR_NANS, but true if the given mode distinguishes between
     259     positive and negative zero, and the sign of zero is important.  */
     260  extern bool HONOR_SIGNED_ZEROS (machine_mode);
     261  extern bool HONOR_SIGNED_ZEROS (const_tree);
     262  extern bool HONOR_SIGNED_ZEROS (const_rtx);
     263  
     264  /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
     265     and the rounding mode is important.  */
     266  extern bool HONOR_SIGN_DEPENDENT_ROUNDING (machine_mode);
     267  extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_tree);
     268  extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_rtx);
     269  
     270  /* Binary or unary arithmetic on tree_code.  */
     271  extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *,
     272  			     const REAL_VALUE_TYPE *);
     273  
     274  /* Compare reals by tree_code.  */
     275  extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
     276  
     277  /* Determine whether a floating-point value X is infinite.  */
     278  extern bool real_isinf (const REAL_VALUE_TYPE *);
     279  
     280  /* Determine whether a floating-point value X is infinite with SIGN.  */
     281  extern bool real_isinf (const REAL_VALUE_TYPE *, bool sign);
     282  
     283  /* Determine whether a floating-point value X is a NaN.  */
     284  extern bool real_isnan (const REAL_VALUE_TYPE *);
     285  
     286  /* Determine whether a floating-point value X is a signaling NaN.  */
     287  extern bool real_issignaling_nan (const REAL_VALUE_TYPE *);
     288  
     289  /* Determine whether floating-point value R is a denormal.  This
     290     function is only valid for normalized values.  */
     291  inline bool
     292  real_isdenormal (const REAL_VALUE_TYPE *r, machine_mode mode)
     293  {
     294    return r->cl == rvc_normal && REAL_EXP (r) < REAL_MODE_FORMAT (mode)->emin;
     295  }
     296  
     297  /* Determine whether a floating-point value X is finite.  */
     298  extern bool real_isfinite (const REAL_VALUE_TYPE *);
     299  
     300  /* Determine whether a floating-point value X is negative.  */
     301  extern bool real_isneg (const REAL_VALUE_TYPE *);
     302  
     303  /* Determine whether a floating-point value X is minus zero.  */
     304  extern bool real_isnegzero (const REAL_VALUE_TYPE *);
     305  
     306  /* Determine whether a floating-point value X is plus or minus zero.  */
     307  extern bool real_iszero (const REAL_VALUE_TYPE *);
     308  
     309  /* Determine whether a floating-point value X is zero with SIGN.  */
     310  extern bool real_iszero (const REAL_VALUE_TYPE *, bool sign);
     311  
     312  /* Test relationships between reals.  */
     313  extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
     314  extern bool real_equal (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
     315  extern bool real_less (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
     316  
     317  /* Extend or truncate to a new format.  */
     318  extern void real_convert (REAL_VALUE_TYPE *, format_helper,
     319  			  const REAL_VALUE_TYPE *);
     320  
     321  /* Return true if truncating to NEW is exact.  */
     322  extern bool exact_real_truncate (format_helper, const REAL_VALUE_TYPE *);
     323  
     324  /* Render R as a decimal floating point constant.  */
     325  extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t,
     326  			     size_t, int);
     327  
     328  /* Render R as a decimal floating point constant, rounded so as to be
     329     parsed back to the same value when interpreted in mode MODE.  */
     330  extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t,
     331  				      size_t, int, machine_mode);
     332  
     333  /* Render R as a hexadecimal floating point constant.  */
     334  extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *,
     335  				 size_t, size_t, int);
     336  
     337  /* Render R as an integer.  */
     338  extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *);
     339  
     340  /* Initialize R from a decimal or hexadecimal string.  Return -1 if
     341     the value underflows, +1 if overflows, and 0 otherwise.  */
     342  extern int real_from_string (REAL_VALUE_TYPE *, const char *);
     343  /* Wrapper to allow different internal representation for decimal floats. */
     344  extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, format_helper);
     345  
     346  extern long real_to_target (long *, const REAL_VALUE_TYPE *, format_helper);
     347  
     348  extern void real_from_target (REAL_VALUE_TYPE *, const long *,
     349  			      format_helper);
     350  
     351  extern void real_inf (REAL_VALUE_TYPE *, bool sign = false);
     352  
     353  extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, format_helper);
     354  
     355  extern void real_maxval (REAL_VALUE_TYPE *, int, machine_mode);
     356  
     357  extern void real_2expN (REAL_VALUE_TYPE *, int, format_helper);
     358  
     359  extern unsigned int real_hash (const REAL_VALUE_TYPE *);
     360  
     361  
     362  /* Target formats defined in real.cc.  */
     363  extern const struct real_format ieee_single_format;
     364  extern const struct real_format mips_single_format;
     365  extern const struct real_format motorola_single_format;
     366  extern const struct real_format spu_single_format;
     367  extern const struct real_format ieee_double_format;
     368  extern const struct real_format mips_double_format;
     369  extern const struct real_format motorola_double_format;
     370  extern const struct real_format ieee_extended_motorola_format;
     371  extern const struct real_format ieee_extended_intel_96_format;
     372  extern const struct real_format ieee_extended_intel_96_round_53_format;
     373  extern const struct real_format ieee_extended_intel_128_format;
     374  extern const struct real_format ibm_extended_format;
     375  extern const struct real_format mips_extended_format;
     376  extern const struct real_format ieee_quad_format;
     377  extern const struct real_format mips_quad_format;
     378  extern const struct real_format vax_f_format;
     379  extern const struct real_format vax_d_format;
     380  extern const struct real_format vax_g_format;
     381  extern const struct real_format real_internal_format;
     382  extern const struct real_format decimal_single_format;
     383  extern const struct real_format decimal_double_format;
     384  extern const struct real_format decimal_quad_format;
     385  extern const struct real_format ieee_half_format;
     386  extern const struct real_format arm_half_format;
     387  extern const struct real_format arm_bfloat_half_format;
     388  
     389  
     390  /* ====================================================================== */
     391  /* Crap.  */
     392  
     393  /* Determine whether a floating-point value X is infinite.  */
     394  #define REAL_VALUE_ISINF(x)		real_isinf (&(x))
     395  
     396  /* Determine whether a floating-point value X is a NaN.  */
     397  #define REAL_VALUE_ISNAN(x)		real_isnan (&(x))
     398  
     399  /* Determine whether a floating-point value X is a signaling NaN.  */ 
     400  #define REAL_VALUE_ISSIGNALING_NAN(x)  real_issignaling_nan (&(x))
     401  
     402  /* Determine whether a floating-point value X is negative.  */
     403  #define REAL_VALUE_NEGATIVE(x)		real_isneg (&(x))
     404  
     405  /* Determine whether a floating-point value X is minus zero.  */
     406  #define REAL_VALUE_MINUS_ZERO(x)	real_isnegzero (&(x))
     407  
     408  /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
     409  #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT)			\
     410    real_to_target (OUT, &(IN),						\
     411  		  float_mode_for_size (LONG_DOUBLE_TYPE_SIZE).require ())
     412  
     413  #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
     414    real_to_target (OUT, &(IN), float_mode_for_size (64).require ())
     415  
     416  /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
     417  #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
     418    ((OUT) = real_to_target (NULL, &(IN), float_mode_for_size (32).require ()))
     419  
     420  /* Real values to IEEE 754 decimal floats.  */
     421  
     422  /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
     423  #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \
     424    real_to_target (OUT, &(IN), decimal_float_mode_for_size (128).require ())
     425  
     426  #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
     427    real_to_target (OUT, &(IN), decimal_float_mode_for_size (64).require ())
     428  
     429  /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
     430  #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \
     431    ((OUT) = real_to_target (NULL, &(IN), \
     432  			   decimal_float_mode_for_size (32).require ()))
     433  
     434  extern REAL_VALUE_TYPE real_value_truncate (format_helper, REAL_VALUE_TYPE);
     435  
     436  extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *);
     437  extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *);
     438  
     439  extern int significand_size (format_helper);
     440  
     441  extern REAL_VALUE_TYPE real_from_string2 (const char *, format_helper);
     442  
     443  #define REAL_VALUE_ATOF(s, m) \
     444    real_from_string2 (s, m)
     445  
     446  #define CONST_DOUBLE_ATOF(s, m) \
     447    const_double_from_real_value (real_from_string2 (s, m), m)
     448  
     449  #define REAL_VALUE_FIX(r) \
     450    real_to_integer (&(r))
     451  
     452  /* ??? Not quite right.  */
     453  #define REAL_VALUE_UNSIGNED_FIX(r) \
     454    real_to_integer (&(r))
     455  
     456  /* ??? These were added for Paranoia support.  */
     457  
     458  /* Return floor log2(R).  */
     459  extern int real_exponent (const REAL_VALUE_TYPE *);
     460  
     461  /* R = A * 2**EXP.  */
     462  extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
     463  
     464  /* **** End of software floating point emulator interface macros **** */
     465  
     466  /* Constant real values 0, 1, 2, -1 and 0.5.  */
     467  
     468  extern REAL_VALUE_TYPE dconst0;
     469  extern REAL_VALUE_TYPE dconst1;
     470  extern REAL_VALUE_TYPE dconst2;
     471  extern REAL_VALUE_TYPE dconstm1;
     472  extern REAL_VALUE_TYPE dconsthalf;
     473  extern REAL_VALUE_TYPE dconstinf;
     474  extern REAL_VALUE_TYPE dconstninf;
     475  
     476  #define dconst_e() (*dconst_e_ptr ())
     477  #define dconst_third() (*dconst_third_ptr ())
     478  #define dconst_quarter() (*dconst_quarter_ptr ())
     479  #define dconst_sixth() (*dconst_sixth_ptr ())
     480  #define dconst_ninth() (*dconst_ninth_ptr ())
     481  #define dconst_sqrt2() (*dconst_sqrt2_ptr ())
     482  
     483  /* Function to return the real value special constant 'e'.  */
     484  extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
     485  
     486  /* Returns a cached REAL_VALUE_TYPE corresponding to 1/n, for various n.  */
     487  extern const REAL_VALUE_TYPE *dconst_third_ptr (void);
     488  extern const REAL_VALUE_TYPE *dconst_quarter_ptr (void);
     489  extern const REAL_VALUE_TYPE *dconst_sixth_ptr (void);
     490  extern const REAL_VALUE_TYPE *dconst_ninth_ptr (void);
     491  
     492  /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2).  */
     493  extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
     494  
     495  /* Function to return a real value (not a tree node)
     496     from a given integer constant.  */
     497  REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree);
     498  
     499  /* Return a CONST_DOUBLE with value R and mode M.  */
     500  extern rtx const_double_from_real_value (REAL_VALUE_TYPE, machine_mode);
     501  
     502  /* Replace R by 1/R in the given format, if the result is exact.  */
     503  extern bool exact_real_inverse (format_helper, REAL_VALUE_TYPE *);
     504  
     505  /* Return true if arithmetic on values in IMODE that were promoted
     506     from values in TMODE is equivalent to direct arithmetic on values
     507     in TMODE.  */
     508  bool real_can_shorten_arithmetic (machine_mode, machine_mode);
     509  
     510  /* In tree.cc: wrap up a REAL_VALUE_TYPE in a tree node.  */
     511  extern tree build_real (tree, REAL_VALUE_TYPE);
     512  
     513  /* Likewise, but first truncate the value to the type.  */
     514  extern tree build_real_truncate (tree, REAL_VALUE_TYPE);
     515  
     516  /* Calculate R as X raised to the integer exponent N in format FMT.  */
     517  extern bool real_powi (REAL_VALUE_TYPE *, format_helper,
     518  		       const REAL_VALUE_TYPE *, HOST_WIDE_INT);
     519  
     520  /* Standard round to integer value functions.  */
     521  extern void real_trunc (REAL_VALUE_TYPE *, format_helper,
     522  			const REAL_VALUE_TYPE *);
     523  extern void real_floor (REAL_VALUE_TYPE *, format_helper,
     524  			const REAL_VALUE_TYPE *);
     525  extern void real_ceil (REAL_VALUE_TYPE *, format_helper,
     526  		       const REAL_VALUE_TYPE *);
     527  extern void real_round (REAL_VALUE_TYPE *, format_helper,
     528  			const REAL_VALUE_TYPE *);
     529  extern void real_roundeven (REAL_VALUE_TYPE *, format_helper,
     530  			    const REAL_VALUE_TYPE *);
     531  
     532  /* Set the sign of R to the sign of X.  */
     533  extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
     534  
     535  /* Check whether the real constant value given is an integer.  */
     536  extern bool real_isinteger (const REAL_VALUE_TYPE *, format_helper);
     537  extern bool real_isinteger (const REAL_VALUE_TYPE *, HOST_WIDE_INT *);
     538  
     539  /* Calculate nextafter (X, Y) in format FMT.  */
     540  extern bool real_nextafter (REAL_VALUE_TYPE *, format_helper,
     541  			    const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
     542  
     543  /* Write into BUF the maximum representable finite floating-point
     544     number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
     545     float string.  BUF must be large enough to contain the result.  */
     546  extern void get_max_float (const struct real_format *, char *, size_t, bool);
     547  
     548  #ifndef GENERATOR_FILE
     549  /* real related routines.  */
     550  extern wide_int real_to_integer (const REAL_VALUE_TYPE *, bool *, int);
     551  extern void real_from_integer (REAL_VALUE_TYPE *, format_helper,
     552  			       const wide_int_ref &, signop);
     553  #endif
     554  
     555  /* Fills r with the largest value such that 1 + r*r won't overflow.
     556     This is used in both sin (atan (x)) and cos (atan(x)) optimizations. */
     557  extern void build_sinatan_real (REAL_VALUE_TYPE *, tree); 
     558  
     559  #endif /* ! GCC_REAL_H */