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Fix for [BZ #15680] IBM long double inaccuracy
[thirdparty/glibc.git] / sysdeps / x86_64 / fpu / printf_fphex.c
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c9cf6dde 1/* Print floating point number in hexadecimal notation according to ISO C99.
568035b7 2 Copyright (C) 1997-2013 Free Software Foundation, Inc.
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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
59ba27a6
PE
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
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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 \
24do { \
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 \
29 \
30 num = (((unsigned long long int) fpnum.ldbl.ieee.mantissa0) << 32 \
31 | fpnum.ldbl.ieee.mantissa1); \
32 \
33 zero_mantissa = num == 0; \
34 \
35 if (sizeof (unsigned long int) > 6) \
36 { \
37 numstr = _itoa_word (num, numbuf + sizeof numbuf, 16, \
38 info->spec == 'A'); \
39 wnumstr = _itowa_word (num, \
40 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),\
41 16, info->spec == 'A'); \
42 } \
43 else \
44 { \
45 numstr = _itoa (num, numbuf + sizeof numbuf, 16, info->spec == 'A');\
46 wnumstr = _itowa (num, \
47 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t), \
48 16, info->spec == 'A'); \
49 } \
50 \
51 /* Fill with zeroes. */ \
52 while (numstr > numbuf + (sizeof numbuf - 64 / 4)) \
53 { \
54 *--numstr = '0'; \
55 *--wnumstr = L'0'; \
56 } \
57 \
58 /* We use a full nibble for the leading digit. */ \
59 leading = *numstr++; \
a53b7a4e 60 wnumstr++; \
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61 \
62 /* We have 3 bits from the mantissa in the leading nibble. \
63 Therefore we are here using `IEEE854_LONG_DOUBLE_BIAS + 3'. */ \
64 exponent = fpnum.ldbl.ieee.exponent; \
65 \
66 if (exponent == 0) \
67 { \
68 if (zero_mantissa) \
69 expnegative = 0; \
70 else \
71 { \
72 /* This is a denormalized number. */ \
73 expnegative = 1; \
74 /* This is a hook for the m68k long double format, where the \
75 exponent bias is the same for normalized and denormalized \
76 numbers. */ \
77 exponent = LONG_DOUBLE_DENORM_BIAS + 3; \
78 } \
79 } \
80 else if (exponent >= IEEE854_LONG_DOUBLE_BIAS + 3) \
81 { \
82 expnegative = 0; \
83 exponent -= IEEE854_LONG_DOUBLE_BIAS + 3; \
84 } \
85 else \
86 { \
87 expnegative = 1; \
88 exponent = -(exponent - (IEEE854_LONG_DOUBLE_BIAS + 3)); \
89 } \
90} while (0)
91
b6ab06ce 92#include <stdio-common/printf_fphex.c>