gcc_float.h

Go to the documentation of this file.

/* Copyright (C) 2002 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */

/* As a special exception, if you include this header file into source
   files compiled by GCC, this header file does not by itself cause
   the resulting executable to be covered by the GNU General Public
   License.  This exception does not however invalidate any other
   reasons why the executable file might be covered by the GNU General
   Public License.  */

/*
 * ISO C Standard:  5.2.4.2.2  Characteristics of floating types <float.h>
 */

#ifndef _FLOAT_H___
#define _FLOAT_H___

/* Radix of exponent representation, b. */
#undef FLT_RADIX
#define FLT_RADIX   __FLT_RADIX__

/* Number of base-FLT_RADIX digits in the significand, p.  */
#undef FLT_MANT_DIG
#undef DBL_MANT_DIG
#undef LDBL_MANT_DIG
#define FLT_MANT_DIG    __FLT_MANT_DIG__
#define DBL_MANT_DIG    __DBL_MANT_DIG__
#define LDBL_MANT_DIG   __LDBL_MANT_DIG__

/* Number of decimal digits, q, such that any floating-point number with q
   decimal digits can be rounded into a floating-point number with p radix b
   digits and back again without change to the q decimal digits,

    p * log10(b)            if b is a power of 10
    floor((p - 1) * log10(b))   otherwise
*/
#undef FLT_DIG
#undef DBL_DIG
#undef LDBL_DIG
#define FLT_DIG     __FLT_DIG__
#define DBL_DIG     __DBL_DIG__
#define LDBL_DIG    __LDBL_DIG__

/* Minimum int x such that FLT_RADIX**(x-1) is a normalized float, emin */
#undef FLT_MIN_EXP
#undef DBL_MIN_EXP
#undef LDBL_MIN_EXP
#define FLT_MIN_EXP __FLT_MIN_EXP__
#define DBL_MIN_EXP __DBL_MIN_EXP__
#define LDBL_MIN_EXP    __LDBL_MIN_EXP__

/* Minimum negative integer such that 10 raised to that power is in the
   range of normalized floating-point numbers,

    ceil(log10(b) * (emin - 1))
*/
#undef FLT_MIN_10_EXP
#undef DBL_MIN_10_EXP
#undef LDBL_MIN_10_EXP
#define FLT_MIN_10_EXP  __FLT_MIN_10_EXP__
#define DBL_MIN_10_EXP  __DBL_MIN_10_EXP__
#define LDBL_MIN_10_EXP __LDBL_MIN_10_EXP__

/* Maximum int x such that FLT_RADIX**(x-1) is a representable float, emax.  */
#undef FLT_MAX_EXP
#undef DBL_MAX_EXP
#undef LDBL_MAX_EXP
#define FLT_MAX_EXP __FLT_MAX_EXP__
#define DBL_MAX_EXP __DBL_MAX_EXP__
#define LDBL_MAX_EXP    __LDBL_MAX_EXP__

/* Maximum integer such that 10 raised to that power is in the range of
   representable finite floating-point numbers,

    floor(log10((1 - b**-p) * b**emax))
*/
#undef FLT_MAX_10_EXP
#undef DBL_MAX_10_EXP
#undef LDBL_MAX_10_EXP
#define FLT_MAX_10_EXP  __FLT_MAX_10_EXP__
#define DBL_MAX_10_EXP  __DBL_MAX_10_EXP__
#define LDBL_MAX_10_EXP __LDBL_MAX_10_EXP__

/* Maximum representable finite floating-point number,

    (1 - b**-p) * b**emax
*/
#undef FLT_MAX
#undef DBL_MAX
#undef LDBL_MAX
#define FLT_MAX     __FLT_MAX__
#define DBL_MAX     __DBL_MAX__
#define LDBL_MAX    __LDBL_MAX__

/* The difference between 1 and the least value greater than 1 that is
   representable in the given floating point type, b**1-p.  */
#undef FLT_EPSILON
#undef DBL_EPSILON
#undef LDBL_EPSILON
#define FLT_EPSILON __FLT_EPSILON__
#define DBL_EPSILON __DBL_EPSILON__
#define LDBL_EPSILON    __LDBL_EPSILON__

/* Minimum normalized positive floating-point number, b**(emin - 1).  */
#undef FLT_MIN
#undef DBL_MIN
#undef LDBL_MIN
#define FLT_MIN     __FLT_MIN__
#define DBL_MIN     __DBL_MIN__
#define LDBL_MIN    __LDBL_MIN__

/* Addition rounds to 0: zero, 1: nearest, 2: +inf, 3: -inf, -1: unknown.  */
/* ??? This is supposed to change with calls to fesetround in <fenv.h>.  */
#undef FLT_ROUNDS
#define FLT_ROUNDS 1

#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
/* The floating-point expression evaluation method.
        -1  indeterminate
         0  evaluate all operations and constants just to the range and
            precision of the type
         1  evaluate operations and constants of type float and double
            to the range and precision of the double type, evaluate
            long double operations and constants to the range and
            precision of the long double type
         2  evaluate all operations and constants to the range and
            precision of the long double type

   ??? This ought to change with the setting of the fp control word;
   the value provided by the compiler assumes the widest setting.  */
#undef FLT_EVAL_METHOD
#define FLT_EVAL_METHOD __FLT_EVAL_METHOD__

/* Number of decimal digits, n, such that any floating-point number in the
   widest supported floating type with pmax radix b digits can be rounded
   to a floating-point number with n decimal digits and back again without
   change to the value,

    pmax * log10(b)         if b is a power of 10
    ceil(1 + pmax * log10(b))   otherwise
*/
#undef DECIMAL_DIG
#define DECIMAL_DIG __DECIMAL_DIG__

#endif /* C99 */
#endif /* _FLOAT_H___ */