1 /* _Float128 IEEE like macros.
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 #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
141