1 /* _Float128 IEEE like macros.
2 Copyright (C) 2017-2023 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 #ifndef _IEEE754_FLOAT128_H
19 #define _IEEE754_FLOAT128_H
20
21 #include <endian.h>
22 #include <stdint.h>
23
24 # if __FLOAT_WORD_ORDER == BIG_ENDIAN
25 # define __FLT_EORDER2(t, a, b) t a; t b;
26 # define __FLT_EORDER4(t, a, b, c, d) \
27 t a; t b; t c; t d;
28 # define __FLT_EORDER6(t, a, b, c, d, e, f) \
29 t a; t b; t c; t d; t e; t f;
30 # define __FLT_EORDER7(t, a, b, c, d, e, f, g) \
31 t a; t b; t c; t d; t e; t f; t g;
32 # else
33 # define __FLT_EORDER2(t, a, b) \
34 t b; t a;
35 # define __FLT_EORDER4(t, a, b, c, d) \
36 t d; t c; t b; t a;
37 # define __FLT_EORDER6(t, a, b, c, d, e, f) \
38 t f; t e; t d; t c; t b; t a;
39 # define __FLT_EORDER7(t, a, b, c, d, e, f, g) \
40 t g; t f; t e; t d; t c; t b; t a;
41 # endif
42
43 /* A union which permits us to convert between _Float128 and
44 four 32 bit ints or two 64 bit ints. */
45
46 typedef union
47 {
48 _Float128 value;
49 struct
50 {
51 __FLT_EORDER2 (uint64_t, msw, lsw);
52 } parts64;
53 struct
54 {
55 __FLT_EORDER4 (uint32_t, w0, w1, w2, w3);
56 } parts32;
57 } ieee854_float128_shape_type;
58
59 /* Get two 64 bit ints from a _Float128. */
60
61 # define GET_FLOAT128_WORDS64(ix0,ix1,d) \
62 do { \
63 ieee854_float128_shape_type qw_u; \
64 qw_u.value = (d); \
65 (ix0) = qw_u.parts64.msw; \
66 (ix1) = qw_u.parts64.lsw; \
67 } while (0)
68
69 /* Set a _Float128 from two 64 bit ints. */
70
71 # define SET_FLOAT128_WORDS64(d,ix0,ix1) \
72 do { \
73 ieee854_float128_shape_type qw_u; \
74 qw_u.parts64.msw = (ix0); \
75 qw_u.parts64.lsw = (ix1); \
76 (d) = qw_u.value; \
77 } while (0)
78
79 /* Get the more significant 64 bits of a _Float128 mantissa. */
80
81 # define GET_FLOAT128_MSW64(v,d) \
82 do { \
83 ieee854_float128_shape_type sh_u; \
84 sh_u.value = (d); \
85 (v) = sh_u.parts64.msw; \
86 } while (0)
87
88 /* Set the more significant 64 bits of a _Float128 mantissa from an int. */
89
90 # define SET_FLOAT128_MSW64(d,v) \
91 do { \
92 ieee854_float128_shape_type sh_u; \
93 sh_u.value = (d); \
94 sh_u.parts64.msw = (v); \
95 (d) = sh_u.value; \
96 } while (0)
97
98 /* Get the least significant 64 bits of a _Float128 mantissa. */
99
100 # define GET_FLOAT128_LSW64(v,d) \
101 do { \
102 ieee854_float128_shape_type sh_u; \
103 sh_u.value = (d); \
104 (v) = sh_u.parts64.lsw; \
105 } while (0)
106
107 /* Likewise, some helper macros which are exposed via ieee754.h for
108 C99 real types, but not _Float128. */
109
110 union ieee854_float128
111 {
112 _Float128 d;
113
114 /* This is the IEEE 854 quad-precision format. */
115 struct
116 {
117 __FLT_EORDER6 (unsigned int, negative:1,
118 exponent:15,
119 mantissa0:16,
120 mantissa1:32,
121 mantissa2:32,
122 mantissa3:32)
123 } ieee;
124
125 /* This format makes it easier to see if a NaN is a signalling NaN. */
126 struct
127 {
128 __FLT_EORDER7 (unsigned int, negative:1,
129 exponent:15,
130 quiet_nan:1,
131 mantissa0:15,
132 mantissa1:32,
133 mantissa2:32,
134 mantissa3:32)
135 } ieee_nan;
136 };
137
138 #define IEEE854_FLOAT128_BIAS 0x3fff /* Added to exponent. */
139
140 #endif