1 /* Manipulation of the bit representation of 'long double' quantities. 2 Copyright (C) 1999-2019 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 <http://www.gnu.org/licenses/>. */ 18 19 #ifndef _MATH_LDBL_H_ 20 #define _MATH_LDBL_H_ 1 21 22 #include <stdint.h> 23 #include <endian.h> 24 25 /* A union which permits us to convert between a long double and 26 four 32 bit ints or two 64 bit ints. */ 27 28 #if __FLOAT_WORD_ORDER == __BIG_ENDIAN 29 30 typedef union 31 { 32 long double value; 33 struct 34 { 35 uint64_t msw; 36 uint64_t lsw; 37 } parts64; 38 struct 39 { 40 uint32_t w0, w1, w2, w3; 41 } parts32; 42 } ieee854_long_double_shape_type; 43 44 #endif 45 46 #if __FLOAT_WORD_ORDER == __LITTLE_ENDIAN 47 48 typedef union 49 { 50 long double value; 51 struct 52 { 53 uint64_t lsw; 54 uint64_t msw; 55 } parts64; 56 struct 57 { 58 uint32_t w3, w2, w1, w0; 59 } parts32; 60 } ieee854_long_double_shape_type; 61 62 #endif 63 64 /* Get two 64 bit ints from a long double. */ 65 66 #define GET_LDOUBLE_WORDS64(ix0,ix1,d) \ 67 do { \ 68 ieee854_long_double_shape_type qw_u; \ 69 qw_u.value = (d); \ 70 (ix0) = qw_u.parts64.msw; \ 71 (ix1) = qw_u.parts64.lsw; \ 72 } while (0) 73 74 /* Set a long double from two 64 bit ints. */ 75 76 #define SET_LDOUBLE_WORDS64(d,ix0,ix1) \ 77 do { \ 78 ieee854_long_double_shape_type qw_u; \ 79 qw_u.parts64.msw = (ix0); \ 80 qw_u.parts64.lsw = (ix1); \ 81 (d) = qw_u.value; \ 82 } while (0) 83 84 /* Get the more significant 64 bits of a long double mantissa. */ 85 86 #define GET_LDOUBLE_MSW64(v,d) \ 87 do { \ 88 ieee854_long_double_shape_type sh_u; \ 89 sh_u.value = (d); \ 90 (v) = sh_u.parts64.msw; \ 91 } while (0) 92 93 /* Set the more significant 64 bits of a long double mantissa from an int. */ 94 95 #define SET_LDOUBLE_MSW64(d,v) \ 96 do { \ 97 ieee854_long_double_shape_type sh_u; \ 98 sh_u.value = (d); \ 99 sh_u.parts64.msw = (v); \ 100 (d) = sh_u.value; \ 101 } while (0) 102 103 /* Get the least significant 64 bits of a long double mantissa. */ 104 105 #define GET_LDOUBLE_LSW64(v,d) \ 106 do { \ 107 ieee854_long_double_shape_type sh_u; \ 108 sh_u.value = (d); \ 109 (v) = sh_u.parts64.lsw; \ 110 } while (0) 111 112 /* 113 On a platform already supporting a binary128 long double, 114 _Float128 will alias to long double. This transformation 115 makes aliasing *l functions to *f128 trivial. 116 */ 117 #define _Float128 long double 118 #define L(x) x##L 119 120 #endif /* math_ldbl.h */ 121