1/* Macro to print floating point numbers in hexadecimal notation.
2 Copyright (C) 2017-2022 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#define PRINT_FPHEX(FLOAT, VAR, IEEE854_UNION, IEEE854_BIAS) \
20do { \
21 /* We have 112 bits of mantissa plus one implicit digit. Since \
22 112 bits are representable without rest using hexadecimal \
23 digits we use only the implicit digits for the number before \
24 the decimal point. */ \
25 unsigned long long int num0, num1; \
26 union IEEE854_UNION u; \
27 u.d = VAR; \
28 \
29 assert (sizeof (FLOAT) == 16); \
30 \
31 num0 = (((unsigned long long int) u.ieee.mantissa0) << 32 \
32 | u.ieee.mantissa1); \
33 num1 = (((unsigned long long int) u.ieee.mantissa2) << 32 \
34 | u.ieee.mantissa3); \
35 \
36 zero_mantissa = (num0|num1) == 0; \
37 \
38 if (sizeof (unsigned long int) > 6) \
39 { \
40 numstr = _itoa_word (num1, numbuf + sizeof numbuf, 16, \
41 info->spec == 'A'); \
42 wnumstr = _itowa_word (num1, \
43 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),\
44 16, info->spec == 'A'); \
45 } \
46 else \
47 { \
48 numstr = _itoa (num1, numbuf + sizeof numbuf, 16, \
49 info->spec == 'A'); \
50 wnumstr = _itowa (num1, \
51 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t), \
52 16, info->spec == 'A'); \
53 } \
54 \
55 while (numstr > numbuf + (sizeof numbuf - 64 / 4)) \
56 { \
57 *--numstr = '0'; \
58 *--wnumstr = L'0'; \
59 } \
60 \
61 if (sizeof (unsigned long int) > 6) \
62 { \
63 numstr = _itoa_word (num0, numstr, 16, info->spec == 'A'); \
64 wnumstr = _itowa_word (num0, wnumstr, 16, info->spec == 'A'); \
65 } \
66 else \
67 { \
68 numstr = _itoa (num0, numstr, 16, info->spec == 'A'); \
69 wnumstr = _itowa (num0, wnumstr, 16, info->spec == 'A'); \
70 } \
71 \
72 /* Fill with zeroes. */ \
73 while (numstr > numbuf + (sizeof numbuf - 112 / 4)) \
74 { \
75 *--numstr = '0'; \
76 *--wnumstr = L'0'; \
77 } \
78 \
79 leading = u.ieee.exponent == 0 ? '0' : '1'; \
80 \
81 exponent = u.ieee.exponent; \
82 \
83 if (exponent == 0) \
84 { \
85 if (zero_mantissa) \
86 expnegative = 0; \
87 else \
88 { \
89 /* This is a denormalized number. */ \
90 expnegative = 1; \
91 exponent = IEEE854_BIAS - 1; \
92 } \
93 } \
94 else if (exponent >= IEEE854_BIAS) \
95 { \
96 expnegative = 0; \
97 exponent -= IEEE854_BIAS; \
98 } \
99 else \
100 { \
101 expnegative = 1; \
102 exponent = -(exponent - IEEE854_BIAS); \
103 } \
104} while (0)
105

source code of glibc/sysdeps/ieee754/ldbl-128/printf_fphex_macros.h