| Austin Schuh | bb1338c | 2024-06-15 19:31:16 -0700 | [diff] [blame] | 1 | /* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL. |
| 2 | |
| 3 | Copyright 1995, 1996, 2000-2003, 2006, 2015 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of the GNU MP Library. |
| 6 | |
| 7 | The GNU MP Library is free software; you can redistribute it and/or modify |
| 8 | it under the terms of either: |
| 9 | |
| 10 | * the GNU Lesser General Public License as published by the Free |
| 11 | Software Foundation; either version 3 of the License, or (at your |
| 12 | option) any later version. |
| 13 | |
| 14 | or |
| 15 | |
| 16 | * the GNU General Public License as published by the Free Software |
| 17 | Foundation; either version 2 of the License, or (at your option) any |
| 18 | later version. |
| 19 | |
| 20 | or both in parallel, as here. |
| 21 | |
| 22 | The GNU MP Library is distributed in the hope that it will be useful, but |
| 23 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 24 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 25 | for more details. |
| 26 | |
| 27 | You should have received copies of the GNU General Public License and the |
| 28 | GNU Lesser General Public License along with the GNU MP Library. If not, |
| 29 | see https://www.gnu.org/licenses/. */ |
| 30 | |
| 31 | #include "config.h" |
| 32 | |
| 33 | #if HAVE_FLOAT_H |
| 34 | #include <float.h> /* for DBL_MAX */ |
| 35 | #endif |
| 36 | |
| 37 | #include "gmp-impl.h" |
| 38 | |
| 39 | |
| 40 | /* We used to have a special case for d < MP_BASE_AS_DOUBLE, just casting |
| 41 | double -> limb. Unfortunately gcc 3.3 on powerpc970-apple-darwin6.8.5 |
| 42 | got this wrong. (It assumed __fixunsdfdi returned its result in a single |
| 43 | 64-bit register, where instead that function followed the calling |
| 44 | conventions and gave the result in two parts r3 and r4.) Hence the use |
| 45 | of __gmp_extract_double in all cases. */ |
| 46 | |
| 47 | void |
| 48 | mpz_set_d (mpz_ptr r, double d) |
| 49 | { |
| 50 | int negative; |
| 51 | mp_limb_t tp[LIMBS_PER_DOUBLE]; |
| 52 | mp_ptr rp; |
| 53 | mp_size_t rn; |
| 54 | |
| 55 | DOUBLE_NAN_INF_ACTION (d, |
| 56 | __gmp_invalid_operation (), |
| 57 | __gmp_invalid_operation ()); |
| 58 | |
| 59 | negative = d < 0; |
| 60 | d = ABS (d); |
| 61 | |
| 62 | rn = __gmp_extract_double (tp, d); |
| 63 | |
| 64 | if (rn <= 0) |
| 65 | rn = 0; |
| 66 | |
| 67 | rp = MPZ_NEWALLOC (r, rn); |
| 68 | |
| 69 | switch (rn) |
| 70 | { |
| 71 | default: |
| 72 | MPN_ZERO (rp, rn - LIMBS_PER_DOUBLE); |
| 73 | rp += rn - LIMBS_PER_DOUBLE; |
| 74 | /* fall through */ |
| 75 | #if LIMBS_PER_DOUBLE == 2 |
| 76 | case 2: |
| 77 | rp[1] = tp[1], rp[0] = tp[0]; |
| 78 | break; |
| 79 | case 1: |
| 80 | rp[0] = tp[1]; |
| 81 | break; |
| 82 | #endif |
| 83 | #if LIMBS_PER_DOUBLE == 3 |
| 84 | case 3: |
| 85 | rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0]; |
| 86 | break; |
| 87 | case 2: |
| 88 | rp[1] = tp[2], rp[0] = tp[1]; |
| 89 | break; |
| 90 | case 1: |
| 91 | rp[0] = tp[2]; |
| 92 | break; |
| 93 | #endif |
| 94 | #if LIMBS_PER_DOUBLE == 4 |
| 95 | case 4: |
| 96 | rp[3] = tp[3], rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0]; |
| 97 | break; |
| 98 | case 3: |
| 99 | rp[2] = tp[3], rp[1] = tp[2], rp[0] = tp[1]; |
| 100 | break; |
| 101 | case 2: |
| 102 | rp[1] = tp[3], rp[0] = tp[2]; |
| 103 | break; |
| 104 | case 1: |
| 105 | rp[0] = tp[3]; |
| 106 | break; |
| 107 | #endif |
| 108 | case 0: |
| 109 | break; |
| 110 | } |
| 111 | |
| 112 | SIZ(r) = negative ? -rn : rn; |
| 113 | } |