1 /* Manipulation of the bit representation of 'long double' quantities. 2 Copyright (C) 2000-2022 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 #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 three 32 bit ints. */ 27 28 #if __FLOAT_WORD_ORDER == __BIG_ENDIAN 29 30 typedef union 31 { 32 long double value; 33 struct 34 { 35 unsigned int empty0:32; 36 int sign_exponent:16; 37 unsigned int empty1:16; 38 uint32_t msw; 39 uint32_t lsw; 40 } parts; 41 } ieee_long_double_shape_type; 42 43 #endif 44 45 #if __FLOAT_WORD_ORDER == __LITTLE_ENDIAN 46 47 typedef union 48 { 49 long double value; 50 struct 51 { 52 uint32_t lsw; 53 uint32_t msw; 54 int sign_exponent:16; 55 unsigned int empty1:16; 56 unsigned int empty0:32; 57 } parts; 58 } ieee_long_double_shape_type; 59 60 #endif 61 62 /* Get three 32 bit ints from a double. */ 63 64 #define GET_LDOUBLE_WORDS(exp,ix0,ix1,d) \ 65 do { \ 66 ieee_long_double_shape_type ew_u; \ 67 ew_u.value = (d); \ 68 (exp) = ew_u.parts.sign_exponent; \ 69 (ix0) = ew_u.parts.msw; \ 70 (ix1) = ew_u.parts.lsw; \ 71 } while (0) 72 73 /* Set a double from two 32 bit ints. */ 74 75 #define SET_LDOUBLE_WORDS(d,exp,ix0,ix1) \ 76 do { \ 77 ieee_long_double_shape_type iw_u; \ 78 iw_u.parts.sign_exponent = (exp); \ 79 iw_u.parts.msw = (ix0); \ 80 iw_u.parts.lsw = (ix1); \ 81 (d) = iw_u.value; \ 82 } while (0) 83 84 /* Get the more significant 32 bits of a long double mantissa. */ 85 86 #define GET_LDOUBLE_MSW(v,d) \ 87 do { \ 88 ieee_long_double_shape_type sh_u; \ 89 sh_u.value = (d); \ 90 (v) = sh_u.parts.msw; \ 91 } while (0) 92 93 /* Set the more significant 32 bits of a long double mantissa from an int. */ 94 95 #define SET_LDOUBLE_MSW(d,v) \ 96 do { \ 97 ieee_long_double_shape_type sh_u; \ 98 sh_u.value = (d); \ 99 sh_u.parts.msw = (v); \ 100 (d) = sh_u.value; \ 101 } while (0) 102 103 /* Get int from the exponent of a long double. */ 104 105 #define GET_LDOUBLE_EXP(exp,d) \ 106 do { \ 107 ieee_long_double_shape_type ge_u; \ 108 ge_u.value = (d); \ 109 (exp) = ge_u.parts.sign_exponent; \ 110 } while (0) 111 112 /* Set exponent of a long double from an int. */ 113 114 #define SET_LDOUBLE_EXP(d,exp) \ 115 do { \ 116 ieee_long_double_shape_type se_u; \ 117 se_u.value = (d); \ 118 se_u.parts.sign_exponent = (exp); \ 119 (d) = se_u.value; \ 120 } while (0) 121 122 #endif /* math_ldbl.h */ 123