glibc/sysdeps/ieee754/ldbl-128/printf_fphex.c
Alan Modra 1b6adf888d PowerPC floating point little-endian [1 of 15]
http://sourceware.org/ml/libc-alpha/2013-08/msg00081.html

This is the first of a series of patches to ban ieee854_long_double
and the ieee854_long_double macros when using IBM long double.  union
ieee854_long_double just isn't correct for IBM long double, especially
when little-endian, and pretending it is OK has allowed a number of
bugs to remain undetected in sysdeps/ieee754/ldbl-128ibm/.

This changes the few places in generic code that use it.

	* stdio-common/printf_size.c (__printf_size): Don't use
	union ieee854_long_double in fpnum union.
	* stdio-common/printf_fphex.c (__printf_fphex): Likewise.  Use
	signbit macro to retrieve sign from long double.
	* stdio-common/printf_fp.c (___printf_fp): Use signbit macro to
	retrieve sign from long double.
	* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c: Adjust for fpnum change.
	* sysdeps/ieee754/ldbl-128/printf_fphex.c: Likewise.
	* sysdeps/ieee754/ldbl-96/printf_fphex.c: Likewise.
	* sysdeps/x86_64/fpu/printf_fphex.c: Likewise.
	* math/test-misc.c (main): Don't use union ieee854_long_double.
ports/
	* sysdeps/ia64/fpu/printf_fphex.c: Adjust for fpnum change.
2013-10-04 10:31:41 +09:30

108 lines
4.0 KiB
C

/* Print floating point number in hexadecimal notation according to
ISO C99.
Copyright (C) 1997-2013 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
<http://www.gnu.org/licenses/>. */
#define PRINT_FPHEX_LONG_DOUBLE \
do { \
/* We have 112 bits of mantissa plus one implicit digit. Since \
112 bits are representable without rest using hexadecimal \
digits we use only the implicit digits for the number before \
the decimal point. */ \
unsigned long long int num0, num1; \
union ieee854_long_double u; \
u.d = fpnum.ldbl; \
\
assert (sizeof (long double) == 16); \
\
num0 = (((unsigned long long int) u.ieee.mantissa0) << 32 \
| u.ieee.mantissa1); \
num1 = (((unsigned long long int) u.ieee.mantissa2) << 32 \
| u.ieee.mantissa3); \
\
zero_mantissa = (num0|num1) == 0; \
\
if (sizeof (unsigned long int) > 6) \
{ \
numstr = _itoa_word (num1, numbuf + sizeof numbuf, 16, \
info->spec == 'A'); \
wnumstr = _itowa_word (num1, \
wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),\
16, info->spec == 'A'); \
} \
else \
{ \
numstr = _itoa (num1, numbuf + sizeof numbuf, 16, \
info->spec == 'A'); \
wnumstr = _itowa (num1, \
wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t), \
16, info->spec == 'A'); \
} \
\
while (numstr > numbuf + (sizeof numbuf - 64 / 4)) \
{ \
*--numstr = '0'; \
*--wnumstr = L'0'; \
} \
\
if (sizeof (unsigned long int) > 6) \
{ \
numstr = _itoa_word (num0, numstr, 16, info->spec == 'A'); \
wnumstr = _itowa_word (num0, wnumstr, 16, info->spec == 'A'); \
} \
else \
{ \
numstr = _itoa (num0, numstr, 16, info->spec == 'A'); \
wnumstr = _itowa (num0, wnumstr, 16, info->spec == 'A'); \
} \
\
/* Fill with zeroes. */ \
while (numstr > numbuf + (sizeof numbuf - 112 / 4)) \
{ \
*--numstr = '0'; \
*--wnumstr = L'0'; \
} \
\
leading = u.ieee.exponent == 0 ? '0' : '1'; \
\
exponent = u.ieee.exponent; \
\
if (exponent == 0) \
{ \
if (zero_mantissa) \
expnegative = 0; \
else \
{ \
/* This is a denormalized number. */ \
expnegative = 1; \
exponent = IEEE854_LONG_DOUBLE_BIAS - 1; \
} \
} \
else if (exponent >= IEEE854_LONG_DOUBLE_BIAS) \
{ \
expnegative = 0; \
exponent -= IEEE854_LONG_DOUBLE_BIAS; \
} \
else \
{ \
expnegative = 1; \
exponent = -(exponent - IEEE854_LONG_DOUBLE_BIAS); \
} \
} while (0)
#include <stdio-common/printf_fphex.c>