projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 63551311 | 1 | /* Round long double to integer away from zero. |
| d7826aa1 | 2 | Copyright (C) 1997, 2007, 2011 Free Software Foundation, Inc. |
| 63551311 UD |
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 | |
| 41bdb6e2 AJ |
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. | |
| 63551311 UD |
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 | |
| 41bdb6e2 | 14 | Lesser General Public License for more details. |
| 63551311 | 15 | |
| 41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
| 59ba27a6 PE |
17 | License along with the GNU C Library; if not, see |
| 18 | <http://www.gnu.org/licenses/>. */ | |
| 63551311 UD |
19 | |
| 20 | #include <math.h> | |
| 21 | ||
| 22 | #include "math_private.h" | |
| 23 | ||
| 24 | ||
| 701666b7 | 25 | static const long double huge = 1.0e4930L; |
| 63551311 UD |
26 | |
| 27 | ||
| 28 | long double | |
| 29 | __roundl (long double x) | |
| 30 | { | |
| 31 | int32_t j0; | |
| 32 | u_int32_t se, i1, i0; | |
| 33 | ||
| 34 | GET_LDOUBLE_WORDS (se, i0, i1, x); | |
| 35 | j0 = (se & 0x7fff) - 0x3fff; | |
| 36 | if (j0 < 31) | |
| 37 | { | |
| 38 | if (j0 < 0) | |
| 39 | { | |
| d7826aa1 UD |
40 | math_force_eval (huge + x); |
| 41 | se &= 0x8000; | |
| 42 | i0 = i1 = 0; | |
| 43 | if (j0 == -1) | |
| 63551311 | 44 | { |
| d7826aa1 UD |
45 | se |= 0x3fff; |
| 46 | i0 = 0x80000000; | |
| 63551311 UD |
47 | } |
| 48 | } | |
| 49 | else | |
| 50 | { | |
| 51 | u_int32_t i = 0x7fffffff >> j0; | |
| 52 | if (((i0 & i) | i1) == 0) | |
| 53 | /* X is integral. */ | |
| 54 | return x; | |
| d7826aa1 UD |
55 | |
| 56 | /* Raise inexact if x != 0. */ | |
| 57 | math_force_eval (huge + x); | |
| 58 | u_int32_t j = i0 + (0x40000000 >> j0); | |
| 59 | if (j < i0) | |
| 60 | se += 1; | |
| 61 | i0 = (j & ~i) | 0x80000000; | |
| 62 | i1 = 0; | |
| 63551311 UD |
63 | } |
| 64 | } | |
| 65 | else if (j0 > 62) | |
| 66 | { | |
| 67 | if (j0 == 0x4000) | |
| 68 | /* Inf or NaN. */ | |
| 69 | return x + x; | |
| 70 | else | |
| 71 | return x; | |
| 72 | } | |
| 73 | else | |
| 74 | { | |
| 75 | u_int32_t i = 0xffffffff >> (j0 - 31); | |
| 76 | if ((i1 & i) == 0) | |
| 77 | /* X is integral. */ | |
| 78 | return x; | |
| 79 | ||
| d7826aa1 UD |
80 | math_force_eval (huge + x); |
| 81 | /* Raise inexact if x != 0. */ | |
| 82 | u_int32_t j = i1 + (1 << (62 - j0)); | |
| 83 | if (j < i1) | |
| 63551311 | 84 | { |
| d7826aa1 UD |
85 | u_int32_t k = i0 + 1; |
| 86 | if (k < i0) | |
| 63551311 | 87 | { |
| d7826aa1 UD |
88 | se += 1; |
| 89 | k |= 0x80000000; | |
| 63551311 | 90 | } |
| d7826aa1 | 91 | i0 = k; |
| 63551311 | 92 | } |
| d7826aa1 | 93 | i1 = j; |
| 63551311 UD |
94 | i1 &= ~i; |
| 95 | } | |
| 96 | ||
| 97 | SET_LDOUBLE_WORDS (x, se, i0, i1); | |
| 98 | return x; | |
| 99 | } | |
| 100 | weak_alias (__roundl, roundl) |