sysdeps/x86_64/fpu/printf_fphex.c

   1 /* Print floating point number in hexadecimal notation according to ISO C99.
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef LONG_DOUBLE_DENORM_BIAS
  20 # define LONG_DOUBLE_DENORM_BIAS (IEEE854_LONG_DOUBLE_BIAS - 1)
  21 #endif
  22
  23 #define PRINT_FPHEX_LONG_DOUBLE \
  24 do {                                                                          \
  25       /* The "strange" 80 bit format on ix86 and m68k has an explicit         \
  26          leading digit in the 64 bit mantissa.  */                            \
  27       unsigned long long int num;                                             \
  28       union ieee854_long_double u;                                            \
  29       u.d = fpnum.ldbl;                                                       \
  30                                                                               \
  31       num = (((unsigned long long int) u.ieee.mantissa0) << 32                \
  32              | u.ieee.mantissa1);                                             \
  33                                                                               \
  34       zero_mantissa = num == 0;                                               \
  35                                                                               \
  36       if (sizeof (unsigned long int) > 6)                                     \
  37         numstr = _itoa_word (num, numbuf + sizeof numbuf, 16, info->spec == 'A');\
  38       else                                                                    \
  39         numstr = _itoa (num, numbuf + sizeof numbuf, 16, info->spec == 'A');  \
  40                                                                               \
  41       /* Fill with zeroes.  */                                                \
  42       while (numstr > numbuf + (sizeof numbuf - 64 / 4))                      \
  43         *--numstr = '0';                                                      \
  44                                                                               \
  45       /* We use a full nibble for the leading digit.  */                      \
  46       leading = *numstr++;                                                    \
  47                                                                               \
  48       /* We have 3 bits from the mantissa in the leading nibble.              \
  49          Therefore we are here using `IEEE854_LONG_DOUBLE_BIAS + 3'.  */      \
  50       exponent = u.ieee.exponent;                                             \
  51                                                                               \
  52       if (exponent == 0)                                                      \
  53         {                                                                     \
  54           if (zero_mantissa)                                                  \
  55             expnegative = 0;                                                  \
  56           else                                                                \
  57             {                                                                 \
  58               /* This is a denormalized number.  */                           \
  59               expnegative = 1;                                                \
  60               /* This is a hook for the m68k long double format, where the    \
  61                  exponent bias is the same for normalized and denormalized    \
  62                  numbers.  */                                                 \
  63               exponent = LONG_DOUBLE_DENORM_BIAS + 3;                         \
  64             }                                                                 \
  65         }                                                                     \
  66       else if (exponent >= IEEE854_LONG_DOUBLE_BIAS + 3)                      \
  67         {                                                                     \
  68           expnegative = 0;                                                    \
  69           exponent -= IEEE854_LONG_DOUBLE_BIAS + 3;                           \
  70         }                                                                     \
  71       else                                                                    \
  72         {                                                                     \
  73           expnegative = 1;                                                    \
  74           exponent = -(exponent - (IEEE854_LONG_DOUBLE_BIAS + 3));            \
  75         }                                                                     \
  76 } while (0)
  77
  78 #include <stdio-common/printf_fphex.c>