| 1 | /* Round long double to integer away from zero. |
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| 2 | Copyright (C) 1997-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #define NO_MATH_REDIRECT |
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| 20 | #include <math.h> |
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| 21 | |
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| 22 | #include <math_private.h> |
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| 23 | #include <libm-alias-ldouble.h> |
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| 24 | #include <math-use-builtins.h> |
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| 25 | |
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| 26 | |
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| 27 | _Float128 |
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| 28 | __roundl (_Float128 x) |
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| 29 | { |
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| 30 | #if USE_ROUNDL_BUILTIN |
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| 31 | return __builtin_roundl (x); |
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| 32 | #else |
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| 33 | /* Use generic implementation. */ |
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| 34 | int32_t j0; |
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| 35 | uint64_t i1, i0; |
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| 36 | |
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| 37 | GET_LDOUBLE_WORDS64 (i0, i1, x); |
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| 38 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; |
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| 39 | if (j0 < 48) |
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| 40 | { |
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| 41 | if (j0 < 0) |
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| 42 | { |
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| 43 | i0 &= 0x8000000000000000ULL; |
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| 44 | if (j0 == -1) |
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| 45 | i0 |= 0x3fff000000000000LL; |
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| 46 | i1 = 0; |
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| 47 | } |
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| 48 | else |
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| 49 | { |
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| 50 | uint64_t i = 0x0000ffffffffffffLL >> j0; |
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| 51 | if (((i0 & i) | i1) == 0) |
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| 52 | /* X is integral. */ |
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| 53 | return x; |
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| 54 | |
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| 55 | i0 += 0x0000800000000000LL >> j0; |
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| 56 | i0 &= ~i; |
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| 57 | i1 = 0; |
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| 58 | } |
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| 59 | } |
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| 60 | else if (j0 > 111) |
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| 61 | { |
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| 62 | if (j0 == 0x4000) |
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| 63 | /* Inf or NaN. */ |
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| 64 | return x + x; |
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| 65 | else |
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| 66 | return x; |
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| 67 | } |
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| 68 | else |
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| 69 | { |
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| 70 | uint64_t i = -1ULL >> (j0 - 48); |
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| 71 | if ((i1 & i) == 0) |
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| 72 | /* X is integral. */ |
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| 73 | return x; |
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| 74 | |
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| 75 | uint64_t j = i1 + (1LL << (111 - j0)); |
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| 76 | if (j < i1) |
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| 77 | i0 += 1; |
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| 78 | i1 = j; |
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| 79 | i1 &= ~i; |
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| 80 | } |
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| 81 | |
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| 82 | SET_LDOUBLE_WORDS64 (x, i0, i1); |
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| 83 | return x; |
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| 84 | #endif /* ! USE_ROUNDL_BUILTIN */ |
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| 85 | } |
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| 86 | libm_alias_ldouble (__round, round) |
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| 87 | |
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