| 1 | /* Round long double value to long long int. |
| 2 | Copyright (C) 1997-2020 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. |
| 5 | |
| 6 | The GNU C Library is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Lesser General Public |
| 8 | License as published by the Free Software Foundation; either |
| 9 | version 2.1 of the License, or (at your option) any later version. |
| 10 | |
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Lesser General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; if not, see |
| 18 | <https://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <fenv.h> |
| 21 | #include <limits.h> |
| 22 | #include <math.h> |
| 23 | |
| 24 | #include <math_private.h> |
| 25 | #include <libm-alias-ldouble.h> |
| 26 | |
| 27 | |
| 28 | long long int |
| 29 | __llroundl (long double x) |
| 30 | { |
| 31 | int32_t j0; |
| 32 | uint32_t se, i1, i0; |
| 33 | long long int result; |
| 34 | int sign; |
| 35 | |
| 36 | GET_LDOUBLE_WORDS (se, i0, i1, x); |
| 37 | j0 = (se & 0x7fff) - 0x3fff; |
| 38 | sign = (se & 0x8000) != 0 ? -1 : 1; |
| 39 | |
| 40 | if (j0 < 31) |
| 41 | { |
| 42 | if (j0 < 0) |
| 43 | return j0 < -1 ? 0 : sign; |
| 44 | else |
| 45 | { |
| 46 | uint32_t j = i0 + (0x40000000 >> j0); |
| 47 | if (j < i0) |
| 48 | { |
| 49 | j >>= 1; |
| 50 | j |= 0x80000000; |
| 51 | ++j0; |
| 52 | } |
| 53 | |
| 54 | result = j >> (31 - j0); |
| 55 | } |
| 56 | } |
| 57 | else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) |
| 58 | { |
| 59 | if (j0 >= 63) |
| 60 | result = (((long long int) i0 << 32) | i1) << (j0 - 63); |
| 61 | else |
| 62 | { |
| 63 | uint32_t j = i1 + (0x80000000 >> (j0 - 31)); |
| 64 | |
| 65 | result = (long long int) i0; |
| 66 | if (j < i1) |
| 67 | ++result; |
| 68 | |
| 69 | if (j0 > 31) |
| 70 | { |
| 71 | result = (result << (j0 - 31)) | (j >> (63 - j0)); |
| 72 | #ifdef FE_INVALID |
| 73 | if (sign == 1 && result == LLONG_MIN) |
| 74 | /* Rounding brought the value out of range. */ |
| 75 | feraiseexcept (FE_INVALID); |
| 76 | #endif |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | else |
| 81 | { |
| 82 | /* The number is too large. It is left implementation defined |
| 83 | what happens. */ |
| 84 | return (long long int) x; |
| 85 | } |
| 86 | |
| 87 | return sign * result; |
| 88 | } |
| 89 | |
| 90 | libm_alias_ldouble (__llround, llround) |
| 91 | |