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Commit | Line | Data |
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c131718c UD |
1 | /* Round argument to nearest integral value according to current rounding |
2 | direction. | |
dff8da6b | 3 | Copyright (C) 1997-2024 Free Software Foundation, Inc. |
c131718c | 4 | This file is part of the GNU C Library. |
c131718c UD |
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. | |
c131718c 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. |
c131718c | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
c131718c | 19 | |
06d97e5e JM |
20 | #include <fenv.h> |
21 | #include <limits.h> | |
c131718c UD |
22 | #include <math.h> |
23 | ||
aaee3cd8 | 24 | #include <math-narrow-eval.h> |
1ed0291c | 25 | #include <math_private.h> |
1e2bffd0 | 26 | #include <libm-alias-double.h> |
06d97e5e | 27 | #include <fix-fp-int-convert-overflow.h> |
a1981ecb | 28 | #include <math-use-builtins.h> |
c131718c UD |
29 | |
30 | ||
31 | long long int | |
dfd2257a | 32 | __llrint (double x) |
c131718c | 33 | { |
a1981ecb XT |
34 | #if USE_LLRINT_BUILTIN |
35 | return __builtin_llrint (x); | |
36 | #else | |
37 | /* Use generic implementation. */ | |
38 | static const double two52[2] = | |
39 | { | |
40 | 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ | |
41 | -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */ | |
42 | }; | |
43 | ||
dfd2257a | 44 | int32_t j0; |
24ab7723 | 45 | uint32_t i1, i0; |
c131718c | 46 | long long int result; |
54142c44 | 47 | double w; |
dfd2257a UD |
48 | double t; |
49 | int sx; | |
c131718c UD |
50 | |
51 | EXTRACT_WORDS (i0, i1, x); | |
c131718c | 52 | j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; |
dfd2257a UD |
53 | sx = i0 >> 31; |
54 | i0 &= 0xfffff; | |
55 | i0 |= 0x100000; | |
c131718c UD |
56 | |
57 | if (j0 < 20) | |
58 | { | |
54142c44 | 59 | w = math_narrow_eval (two52[sx] + x); |
6624dbc0 UD |
60 | t = w - two52[sx]; |
61 | EXTRACT_WORDS (i0, i1, t); | |
62 | j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; | |
63 | i0 &= 0xfffff; | |
64 | i0 |= 0x100000; | |
dfd2257a | 65 | |
6624dbc0 | 66 | result = (j0 < 0 ? 0 : i0 >> (20 - j0)); |
c131718c | 67 | } |
cc3fa755 | 68 | else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) |
c131718c | 69 | { |
dfd2257a | 70 | if (j0 >= 52) |
cc3fa755 | 71 | result = (((long long int) i0 << 32) | i1) << (j0 - 52); |
c131718c UD |
72 | else |
73 | { | |
54142c44 | 74 | w = math_narrow_eval (two52[sx] + x); |
dfd2257a UD |
75 | t = w - two52[sx]; |
76 | EXTRACT_WORDS (i0, i1, t); | |
dfd2257a | 77 | j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; |
cc3fa755 UD |
78 | i0 &= 0xfffff; |
79 | i0 |= 0x100000; | |
dfd2257a | 80 | |
3eb61415 UD |
81 | if (j0 == 20) |
82 | result = (long long int) i0; | |
83 | else | |
84 | result = ((long long int) i0 << (j0 - 20)) | (i1 >> (52 - j0)); | |
c131718c UD |
85 | } |
86 | } | |
dfd2257a | 87 | else |
c131718c | 88 | { |
06d97e5e JM |
89 | #ifdef FE_INVALID |
90 | /* The number is too large. Unless it rounds to LLONG_MIN, | |
91 | FE_INVALID must be raised and the return value is | |
92 | unspecified. */ | |
93 | if (FIX_DBL_LLONG_CONVERT_OVERFLOW && x != (double) LLONG_MIN) | |
94 | { | |
95 | feraiseexcept (FE_INVALID); | |
96 | return sx == 0 ? LLONG_MAX : LLONG_MIN; | |
97 | } | |
98 | #endif | |
dfd2257a | 99 | return (long long int) x; |
c131718c | 100 | } |
c131718c | 101 | |
dfd2257a | 102 | return sx ? -result : result; |
a1981ecb | 103 | #endif /* ! USE_LLRINT_BUILTIN */ |
c131718c | 104 | } |
c131718c | 105 | |
1e2bffd0 | 106 | libm_alias_double (__llrint, llrint) |