glibc/sysdeps/x86_64/fpu/printf_fphex.c

79 lines
3.1 KiB
C

/* Print floating point number in hexadecimal notation according to ISO C99.
Copyright (C) 1997-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef LONG_DOUBLE_DENORM_BIAS
# define LONG_DOUBLE_DENORM_BIAS (IEEE854_LONG_DOUBLE_BIAS - 1)
#endif
#define PRINT_FPHEX_LONG_DOUBLE \
do { \
/* The "strange" 80 bit format on ix86 and m68k has an explicit \
leading digit in the 64 bit mantissa. */ \
unsigned long long int num; \
union ieee854_long_double u; \
u.d = fpnum.ldbl; \
\
num = (((unsigned long long int) u.ieee.mantissa0) << 32 \
| u.ieee.mantissa1); \
\
zero_mantissa = num == 0; \
\
if (sizeof (unsigned long int) > 6) \
numstr = _itoa_word (num, numbuf + sizeof numbuf, 16, info->spec == 'A');\
else \
numstr = _itoa (num, numbuf + sizeof numbuf, 16, info->spec == 'A'); \
\
/* Fill with zeroes. */ \
while (numstr > numbuf + (sizeof numbuf - 64 / 4)) \
*--numstr = '0'; \
\
/* We use a full nibble for the leading digit. */ \
leading = *numstr++; \
\
/* We have 3 bits from the mantissa in the leading nibble. \
Therefore we are here using `IEEE854_LONG_DOUBLE_BIAS + 3'. */ \
exponent = u.ieee.exponent; \
\
if (exponent == 0) \
{ \
if (zero_mantissa) \
expnegative = 0; \
else \
{ \
/* This is a denormalized number. */ \
expnegative = 1; \
/* This is a hook for the m68k long double format, where the \
exponent bias is the same for normalized and denormalized \
numbers. */ \
exponent = LONG_DOUBLE_DENORM_BIAS + 3; \
} \
} \
else if (exponent >= IEEE854_LONG_DOUBLE_BIAS + 3) \
{ \
expnegative = 0; \
exponent -= IEEE854_LONG_DOUBLE_BIAS + 3; \
} \
else \
{ \
expnegative = 1; \
exponent = -(exponent - (IEEE854_LONG_DOUBLE_BIAS + 3)); \
} \
} while (0)
#include <stdio-common/printf_fphex.c>