1 | /* Round argument to nearest integral value according to current rounding |
2 | direction. |
3 | Copyright (C) 1997-2023 Free Software Foundation, Inc. |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
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. |
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 |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <fenv.h> |
21 | #include <limits.h> |
22 | #include <math.h> |
23 | |
24 | #include <math_private.h> |
25 | #include <libm-alias-ldouble.h> |
26 | #include <fix-fp-int-convert-overflow.h> |
27 | #include <math-use-builtins.h> |
28 | |
29 | |
30 | long long int |
31 | __llrintl (_Float128 x) |
32 | { |
33 | #if USE_LLRINTL_BUILTIN |
34 | return __builtin_llrintl (x); |
35 | #else |
36 | /* Use generic implementation. */ |
37 | static const _Float128 two112[2] = |
38 | { |
39 | L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */ |
40 | L(-5.19229685853482762853049632922009600E+33) /* 0xC06F000000000000, 0 */ |
41 | }; |
42 | |
43 | int32_t j0; |
44 | uint64_t i0,i1; |
45 | _Float128 w; |
46 | _Float128 t; |
47 | long long int result; |
48 | int sx; |
49 | |
50 | GET_LDOUBLE_WORDS64 (i0, i1, x); |
51 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; |
52 | sx = i0 >> 63; |
53 | i0 &= 0x0000ffffffffffffLL; |
54 | i0 |= 0x0001000000000000LL; |
55 | |
56 | if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) |
57 | { |
58 | #if defined FE_INVALID || defined FE_INEXACT |
59 | /* X < LLONG_MAX + 1 implied by J0 < 63. */ |
60 | if (x > (_Float128) LLONG_MAX) |
61 | { |
62 | /* In the event of overflow we must raise the "invalid" |
63 | exception, but not "inexact". */ |
64 | t = __nearbyintl (x); |
65 | feraiseexcept (t == LLONG_MAX ? FE_INEXACT : FE_INVALID); |
66 | } |
67 | else |
68 | #endif |
69 | { |
70 | w = two112[sx] + x; |
71 | t = w - two112[sx]; |
72 | } |
73 | GET_LDOUBLE_WORDS64 (i0, i1, t); |
74 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; |
75 | i0 &= 0x0000ffffffffffffLL; |
76 | i0 |= 0x0001000000000000LL; |
77 | |
78 | if (j0 < 0) |
79 | result = 0; |
80 | else if (j0 <= 48) |
81 | result = i0 >> (48 - j0); |
82 | else |
83 | result = ((long long int) i0 << (j0 - 48)) | (i1 >> (112 - j0)); |
84 | } |
85 | else |
86 | { |
87 | /* The number is too large. Unless it rounds to LLONG_MIN, |
88 | FE_INVALID must be raised and the return value is |
89 | unspecified. */ |
90 | #if defined FE_INVALID || defined FE_INEXACT |
91 | if (x < (_Float128) LLONG_MIN |
92 | && x > (_Float128) LLONG_MIN - 1) |
93 | { |
94 | /* If truncation produces LLONG_MIN, the cast will not raise |
95 | the exception, but may raise "inexact". */ |
96 | t = __nearbyintl (x); |
97 | feraiseexcept (t == LLONG_MIN ? FE_INEXACT : FE_INVALID); |
98 | return LLONG_MIN; |
99 | } |
100 | else if (FIX_LDBL_LLONG_CONVERT_OVERFLOW && x != (_Float128) LLONG_MIN) |
101 | { |
102 | feraiseexcept (FE_INVALID); |
103 | return sx == 0 ? LLONG_MAX : LLONG_MIN; |
104 | } |
105 | |
106 | #endif |
107 | return (long long int) x; |
108 | } |
109 | |
110 | return sx ? -result : result; |
111 | #endif /* ! USE_LLRINTL_BUILTIN */ |
112 | } |
113 | |
114 | libm_alias_ldouble (__llrint, llrint) |
115 | |