1 /* Manipulation of the bit representation of 'long double' quantities. 2 Copyright (C) 1999-2022 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 int sign_exponent:16; 36 unsigned int empty:16; 37 uint32_t msw; 38 uint32_t lsw; 39 } parts; 40 } ieee_long_double_shape_type; 41 42 #endif 43 44 #if __FLOAT_WORD_ORDER == __LITTLE_ENDIAN 45 46 typedef union 47 { 48 long double value; 49 struct 50 { 51 uint32_t lsw; 52 uint32_t msw; 53 int sign_exponent:16; 54 unsigned int empty:16; 55 } parts; 56 } ieee_long_double_shape_type; 57 58 #endif 59 60 /* Get three 32 bit ints from a double. */ 61 62 #define GET_LDOUBLE_WORDS(exp,ix0,ix1,d) \ 63 do { \ 64 ieee_long_double_shape_type ew_u; \ 65 ew_u.value = (d); \ 66 (exp) = ew_u.parts.sign_exponent; \ 67 (ix0) = ew_u.parts.msw; \ 68 (ix1) = ew_u.parts.lsw; \ 69 } while (0) 70 71 /* Set a double from two 32 bit ints. */ 72 73 #define SET_LDOUBLE_WORDS(d,exp,ix0,ix1) \ 74 do { \ 75 ieee_long_double_shape_type iw_u; \ 76 iw_u.parts.sign_exponent = (exp); \ 77 iw_u.parts.msw = (ix0); \ 78 iw_u.parts.lsw = (ix1); \ 79 (d) = iw_u.value; \ 80 } while (0) 81 82 /* Get the more significant 32 bits of a long double mantissa. */ 83 84 #define GET_LDOUBLE_MSW(v,d) \ 85 do { \ 86 ieee_long_double_shape_type sh_u; \ 87 sh_u.value = (d); \ 88 (v) = sh_u.parts.msw; \ 89 } while (0) 90 91 /* Set the more significant 32 bits of a long double mantissa from an int. */ 92 93 #define SET_LDOUBLE_MSW(d,v) \ 94 do { \ 95 ieee_long_double_shape_type sh_u; \ 96 sh_u.value = (d); \ 97 sh_u.parts.msw = (v); \ 98 (d) = sh_u.value; \ 99 } while (0) 100 101 /* Get int from the exponent of a long double. */ 102 103 #define GET_LDOUBLE_EXP(exp,d) \ 104 do { \ 105 ieee_long_double_shape_type ge_u; \ 106 ge_u.value = (d); \ 107 (exp) = ge_u.parts.sign_exponent; \ 108 } while (0) 109 110 /* Set exponent of a long double from an int. */ 111 112 #define SET_LDOUBLE_EXP(d,exp) \ 113 do { \ 114 ieee_long_double_shape_type se_u; \ 115 se_u.value = (d); \ 116 se_u.parts.sign_exponent = (exp); \ 117 (d) = se_u.value; \ 118 } while (0) 119 120 #endif /* math_ldbl.h */ 121