projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 63551311 | 1 | /* Round long double to integer away from zero. |
| f7a9f785 | 2 | Copyright (C) 1997-2016 Free Software Foundation, Inc. |
| 63551311 | 3 | This file is part of the GNU C Library. |
| abfbdde1 UD |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and |
| 5 | Jakub Jelinek <jj@ultra.linux.cz>, 1999. | |
| 63551311 UD |
6 | |
| 7 | The GNU C Library is free software; you can redistribute it and/or | |
| 41bdb6e2 AJ |
8 | modify it under the terms of the GNU Lesser General Public |
| 9 | License as published by the Free Software Foundation; either | |
| 10 | version 2.1 of the License, or (at your option) any later version. | |
| 63551311 UD |
11 | |
| 12 | The GNU C Library is distributed in the hope that it will be useful, | |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 41bdb6e2 | 15 | Lesser General Public License for more details. |
| 63551311 | 16 | |
| 41bdb6e2 | 17 | You should have received a copy of the GNU Lesser General Public |
| 59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
| 19 | <http://www.gnu.org/licenses/>. */ | |
| 63551311 UD |
20 | |
| 21 | #include <math.h> | |
| 22 | ||
| 1ed0291c | 23 | #include <math_private.h> |
| 63551311 UD |
24 | |
| 25 | ||
| abfbdde1 | 26 | static const long double huge = 1.0E4930L; |
| 63551311 UD |
27 | |
| 28 | ||
| 29 | long double | |
| 30 | __roundl (long double x) | |
| 31 | { | |
| 32 | int32_t j0; | |
| dbbbaf53 | 33 | u_int64_t i1, i0; |
| 63551311 | 34 | |
| abfbdde1 UD |
35 | GET_LDOUBLE_WORDS64 (i0, i1, x); |
| 36 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; | |
| 7d0b2575 | 37 | if (j0 < 48) |
| 63551311 UD |
38 | { |
| 39 | if (j0 < 0) | |
| 40 | { | |
| 41 | if (huge + x > 0.0) | |
| 42 | { | |
| abfbdde1 | 43 | i0 &= 0x8000000000000000ULL; |
| dd33e89f | 44 | if (j0 == -1) |
| abfbdde1 UD |
45 | i0 |= 0x3fff000000000000LL; |
| 46 | i1 = 0; | |
| 63551311 UD |
47 | } |
| 48 | } | |
| 49 | else | |
| 50 | { | |
| abfbdde1 | 51 | u_int64_t i = 0x0000ffffffffffffLL >> j0; |
| 63551311 UD |
52 | if (((i0 & i) | i1) == 0) |
| 53 | /* X is integral. */ | |
| 54 | return x; | |
| 55 | if (huge + x > 0.0) | |
| 56 | { | |
| 57 | /* Raise inexact if x != 0. */ | |
| abfbdde1 UD |
58 | i0 += 0x0000800000000000LL >> j0; |
| 59 | i0 &= ~i; | |
| 63551311 UD |
60 | i1 = 0; |
| 61 | } | |
| 62 | } | |
| 63 | } | |
| abfbdde1 | 64 | else if (j0 > 111) |
| 63551311 UD |
65 | { |
| 66 | if (j0 == 0x4000) | |
| 67 | /* Inf or NaN. */ | |
| 68 | return x + x; | |
| 69 | else | |
| 70 | return x; | |
| 71 | } | |
| 72 | else | |
| 73 | { | |
| abfbdde1 | 74 | u_int64_t i = -1ULL >> (j0 - 48); |
| 63551311 UD |
75 | if ((i1 & i) == 0) |
| 76 | /* X is integral. */ | |
| 77 | return x; | |
| 78 | ||
| 79 | if (huge + x > 0.0) | |
| 80 | { | |
| 81 | /* Raise inexact if x != 0. */ | |
| abfbdde1 | 82 | u_int64_t j = i1 + (1LL << (111 - j0)); |
| 63551311 | 83 | if (j < i1) |
| abfbdde1 | 84 | i0 += 1; |
| 63551311 UD |
85 | i1 = j; |
| 86 | } | |
| 87 | i1 &= ~i; | |
| 88 | } | |
| 89 | ||
| abfbdde1 | 90 | SET_LDOUBLE_WORDS64 (x, i0, i1); |
| 63551311 UD |
91 | return x; |
| 92 | } | |
| 93 | weak_alias (__roundl, roundl) |