| 1 | /* Round a double value to a long long in the current rounding mode. |
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| 2 | Copyright (C) 1997-2024 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 | #include <limits.h> |
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| 20 | #include <math.h> |
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| 21 | #include <math_ldbl_opt.h> |
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| 22 | #include <math_private.h> |
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| 23 | #include <stdint.h> |
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| 24 | #include <libm-alias-double.h> |
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| 25 | |
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| 26 | long long int |
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| 27 | __llrint (double x) |
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| 28 | { |
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| 29 | #ifdef _ARCH_PWR4 |
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| 30 | /* Assume powerpc64 instructions availability. */ |
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| 31 | long long int ret; |
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| 32 | __asm__ ("fctid %0, %1" : "=d" (ret) : "d" (x)); |
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| 33 | return ret; |
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| 34 | #else |
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| 35 | double rx = rint (x); |
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| 36 | if (HAVE_PPC_FCTIDZ || rx != x) |
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| 37 | return (long long int) rx; |
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| 38 | else |
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| 39 | { |
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| 40 | /* Avoid incorrect exceptions from libgcc conversions (as of GCC |
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| 41 | 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */ |
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| 42 | if (fabs (x: rx) < 0x1p31) |
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| 43 | return (long long int) (long int) rx; |
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| 44 | uint64_t i0; |
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| 45 | EXTRACT_WORDS64 (i0, rx); |
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| 46 | int exponent = ((i0 >> 52) & 0x7ff) - 0x3ff; |
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| 47 | if (exponent < 63) |
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| 48 | { |
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| 49 | unsigned long long int mant |
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| 50 | = (i0 & ((1ULL << 52) - 1)) | (1ULL << 52); |
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| 51 | if (exponent < 52) |
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| 52 | mant >>= 52 - exponent; |
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| 53 | else |
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| 54 | mant <<= exponent - 52; |
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| 55 | return (long long int) ((i0 & (1ULL << 63)) != 0 ? -mant : mant); |
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| 56 | } |
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| 57 | else if (rx == (double) LLONG_MIN) |
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| 58 | return LLONG_MIN; |
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| 59 | else |
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| 60 | return (long long int) (long int) rx << 32; |
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| 61 | } |
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| 62 | #endif |
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| 63 | } |
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| 64 | #ifndef __llrint |
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| 65 | libm_alias_double (__llrint, llrint) |
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| 66 | #endif |
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| 67 | |
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