/* Supplemental information about the floating-point formats.
   Copyright (C) 2007, 2009-2018 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2007.

   This program is free software: you can redistribute it and/or
   modify it under the terms of either:

     * the GNU Lesser General Public License as published by the Free
       Software Foundation; either version 3 of the License, or (at your
       option) any later version.

   or

     * the GNU General Public License as published by the Free
       Software Foundation; either version 2 of the License, or (at your
       option) any later version.

   or both in parallel, as here.
   This program 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 this program; if not, see <https://www.gnu.org/licenses/>.  */

#ifndef _FLOATPLUS_H
#define _FLOATPLUS_H

#include <float.h>
#include <limits.h>

/* Number of bits in the mantissa of a floating-point number, including the
   "hidden bit".  */
#if FLT_RADIX == 2
# define FLT_MANT_BIT FLT_MANT_DIG
# define DBL_MANT_BIT DBL_MANT_DIG
# define LDBL_MANT_BIT LDBL_MANT_DIG
#elif FLT_RADIX == 4
# define FLT_MANT_BIT (FLT_MANT_DIG * 2)
# define DBL_MANT_BIT (DBL_MANT_DIG * 2)
# define LDBL_MANT_BIT (LDBL_MANT_DIG * 2)
#elif FLT_RADIX == 16
# define FLT_MANT_BIT (FLT_MANT_DIG * 4)
# define DBL_MANT_BIT (DBL_MANT_DIG * 4)
# define LDBL_MANT_BIT (LDBL_MANT_DIG * 4)
#endif

/* Bit mask that can be used to mask the exponent, as an unsigned number.  */
#define FLT_EXP_MASK ((FLT_MAX_EXP - FLT_MIN_EXP) | 7)
#define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7)
#define LDBL_EXP_MASK ((LDBL_MAX_EXP - LDBL_MIN_EXP) | 7)

/* Number of bits used for the exponent of a floating-point number, including
   the exponent's sign.  */
#define FLT_EXP_BIT \
  (FLT_EXP_MASK < 0x100 ? 8 : \
   FLT_EXP_MASK < 0x200 ? 9 : \
   FLT_EXP_MASK < 0x400 ? 10 : \
   FLT_EXP_MASK < 0x800 ? 11 : \
   FLT_EXP_MASK < 0x1000 ? 12 : \
   FLT_EXP_MASK < 0x2000 ? 13 : \
   FLT_EXP_MASK < 0x4000 ? 14 : \
   FLT_EXP_MASK < 0x8000 ? 15 : \
   FLT_EXP_MASK < 0x10000 ? 16 : \
   FLT_EXP_MASK < 0x20000 ? 17 : \
   FLT_EXP_MASK < 0x40000 ? 18 : \
   FLT_EXP_MASK < 0x80000 ? 19 : \
   FLT_EXP_MASK < 0x100000 ? 20 : \
   FLT_EXP_MASK < 0x200000 ? 21 : \
   FLT_EXP_MASK < 0x400000 ? 22 : \
   FLT_EXP_MASK < 0x800000 ? 23 : \
   FLT_EXP_MASK < 0x1000000 ? 24 : \
   FLT_EXP_MASK < 0x2000000 ? 25 : \
   FLT_EXP_MASK < 0x4000000 ? 26 : \
   FLT_EXP_MASK < 0x8000000 ? 27 : \
   FLT_EXP_MASK < 0x10000000 ? 28 : \
   FLT_EXP_MASK < 0x20000000 ? 29 : \
   FLT_EXP_MASK < 0x40000000 ? 30 : \
   FLT_EXP_MASK <= 0x7fffffff ? 31 : \
   32)
#define DBL_EXP_BIT \
  (DBL_EXP_MASK < 0x100 ? 8 : \
   DBL_EXP_MASK < 0x200 ? 9 : \
   DBL_EXP_MASK < 0x400 ? 10 : \
   DBL_EXP_MASK < 0x800 ? 11 : \
   DBL_EXP_MASK < 0x1000 ? 12 : \
   DBL_EXP_MASK < 0x2000 ? 13 : \
   DBL_EXP_MASK < 0x4000 ? 14 : \
   DBL_EXP_MASK < 0x8000 ? 15 : \
   DBL_EXP_MASK < 0x10000 ? 16 : \
   DBL_EXP_MASK < 0x20000 ? 17 : \
   DBL_EXP_MASK < 0x40000 ? 18 : \
   DBL_EXP_MASK < 0x80000 ? 19 : \
   DBL_EXP_MASK < 0x100000 ? 20 : \
   DBL_EXP_MASK < 0x200000 ? 21 : \
   DBL_EXP_MASK < 0x400000 ? 22 : \
   DBL_EXP_MASK < 0x800000 ? 23 : \
   DBL_EXP_MASK < 0x1000000 ? 24 : \
   DBL_EXP_MASK < 0x2000000 ? 25 : \
   DBL_EXP_MASK < 0x4000000 ? 26 : \
   DBL_EXP_MASK < 0x8000000 ? 27 : \
   DBL_EXP_MASK < 0x10000000 ? 28 : \
   DBL_EXP_MASK < 0x20000000 ? 29 : \
   DBL_EXP_MASK < 0x40000000 ? 30 : \
   DBL_EXP_MASK <= 0x7fffffff ? 31 : \
   32)
#define LDBL_EXP_BIT \
  (LDBL_EXP_MASK < 0x100 ? 8 : \
   LDBL_EXP_MASK < 0x200 ? 9 : \
   LDBL_EXP_MASK < 0x400 ? 10 : \
   LDBL_EXP_MASK < 0x800 ? 11 : \
   LDBL_EXP_MASK < 0x1000 ? 12 : \
   LDBL_EXP_MASK < 0x2000 ? 13 : \
   LDBL_EXP_MASK < 0x4000 ? 14 : \
   LDBL_EXP_MASK < 0x8000 ? 15 : \
   LDBL_EXP_MASK < 0x10000 ? 16 : \
   LDBL_EXP_MASK < 0x20000 ? 17 : \
   LDBL_EXP_MASK < 0x40000 ? 18 : \
   LDBL_EXP_MASK < 0x80000 ? 19 : \
   LDBL_EXP_MASK < 0x100000 ? 20 : \
   LDBL_EXP_MASK < 0x200000 ? 21 : \
   LDBL_EXP_MASK < 0x400000 ? 22 : \
   LDBL_EXP_MASK < 0x800000 ? 23 : \
   LDBL_EXP_MASK < 0x1000000 ? 24 : \
   LDBL_EXP_MASK < 0x2000000 ? 25 : \
   LDBL_EXP_MASK < 0x4000000 ? 26 : \
   LDBL_EXP_MASK < 0x8000000 ? 27 : \
   LDBL_EXP_MASK < 0x10000000 ? 28 : \
   LDBL_EXP_MASK < 0x20000000 ? 29 : \
   LDBL_EXP_MASK < 0x40000000 ? 30 : \
   LDBL_EXP_MASK <= 0x7fffffff ? 31 : \
   32)

/* Number of bits used for a floating-point number: the mantissa (not
   counting the "hidden bit", since it may or may not be explicit), the
   exponent, and the sign.  */
#define FLT_TOTAL_BIT ((FLT_MANT_BIT - 1) + FLT_EXP_BIT + 1)
#define DBL_TOTAL_BIT ((DBL_MANT_BIT - 1) + DBL_EXP_BIT + 1)
#define LDBL_TOTAL_BIT ((LDBL_MANT_BIT - 1) + LDBL_EXP_BIT + 1)

/* Number of bytes used for a floating-point number.
   This can be smaller than the 'sizeof'.  For example, on i386 systems,
   'long double' most often have LDBL_MANT_BIT = 64, LDBL_EXP_BIT = 16, hence
   LDBL_TOTAL_BIT = 80 bits, i.e. 10 bytes of consecutive memory, but
   sizeof (long double) = 12 or = 16.  */
#define SIZEOF_FLT ((FLT_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT)
#define SIZEOF_DBL ((DBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT)
#define SIZEOF_LDBL ((LDBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT)

/* Verify that SIZEOF_FLT <= sizeof (float) etc.  */
typedef int verify_sizeof_flt[SIZEOF_FLT <= sizeof (float) ? 1 : -1];
typedef int verify_sizeof_dbl[SIZEOF_DBL <= sizeof (double) ? 1 : - 1];
typedef int verify_sizeof_ldbl[SIZEOF_LDBL <= sizeof (long double) ? 1 : - 1];

#endif /* _FLOATPLUS_H */