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1 | /* Round long double value to long long int. | |
2 | Copyright (C) 1997-2019 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and | |
5 | Jakub Jelinek <jj@ultra.linux.cz>, 1999. | |
6 | ||
7 | The GNU C Library is free software; you can redistribute it and/or | |
8 | modify it under the terms of the GNU Lesser General Public | |
9 | License as published by the Free Software Foundation; either | |
10 | version 2.1 of the License, or (at your option) any later version. | |
11 | ||
12 | The GNU C Library is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public | |
18 | License along with the GNU C Library; if not, see | |
19 | <https://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include <fenv.h> | |
22 | #include <limits.h> | |
23 | #include <math.h> | |
24 | ||
25 | #include <math_private.h> | |
26 | #include <libm-alias-ldouble.h> | |
27 | #include <fix-fp-int-convert-overflow.h> | |
28 | ||
29 | long long int | |
30 | __llroundl (_Float128 x) | |
31 | { | |
32 | int64_t j0; | |
33 | uint64_t i1, i0; | |
34 | long long int result; | |
35 | int sign; | |
36 | ||
37 | GET_LDOUBLE_WORDS64 (i0, i1, x); | |
38 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; | |
39 | sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1; | |
40 | i0 &= 0x0000ffffffffffffLL; | |
41 | i0 |= 0x0001000000000000LL; | |
42 | ||
43 | if (j0 < 48) | |
44 | { | |
45 | if (j0 < 0) | |
46 | return j0 < -1 ? 0 : sign; | |
47 | else | |
48 | { | |
49 | i0 += 0x0000800000000000LL >> j0; | |
50 | result = i0 >> (48 - j0); | |
51 | } | |
52 | } | |
53 | else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) | |
54 | { | |
55 | if (j0 >= 112) | |
56 | result = ((long long int) i0 << (j0 - 48)) | (i1 << (j0 - 112)); | |
57 | else | |
58 | { | |
59 | uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48)); | |
60 | if (j < i1) | |
61 | ++i0; | |
62 | ||
63 | if (j0 == 48) | |
64 | result = (long long int) i0; | |
65 | else | |
66 | { | |
67 | result = ((long long int) i0 << (j0 - 48)) | (j >> (112 - j0)); | |
68 | #ifdef FE_INVALID | |
69 | if (sign == 1 && result == LLONG_MIN) | |
70 | /* Rounding brought the value out of range. */ | |
71 | feraiseexcept (FE_INVALID); | |
72 | #endif | |
73 | } | |
74 | } | |
75 | } | |
76 | else | |
77 | { | |
78 | /* The number is too large. Unless it rounds to LLONG_MIN, | |
79 | FE_INVALID must be raised and the return value is | |
80 | unspecified. */ | |
81 | #ifdef FE_INVALID | |
82 | if (FIX_LDBL_LLONG_CONVERT_OVERFLOW | |
83 | && !(sign == -1 && x > (_Float128) LLONG_MIN - L(0.5))) | |
84 | { | |
85 | feraiseexcept (FE_INVALID); | |
86 | return sign == 1 ? LLONG_MAX : LLONG_MIN; | |
87 | } | |
88 | else if (!FIX_LDBL_LLONG_CONVERT_OVERFLOW | |
89 | && x <= (_Float128) LLONG_MIN - L(0.5)) | |
90 | { | |
91 | /* If truncation produces LLONG_MIN, the cast will not raise | |
92 | the exception, but may raise "inexact". */ | |
93 | feraiseexcept (FE_INVALID); | |
94 | return LLONG_MIN; | |
95 | } | |
96 | #endif | |
97 | return (long long int) x; | |
98 | } | |
99 | ||
100 | return sign * result; | |
101 | } | |
102 | ||
103 | libm_alias_ldouble (__llround, llround) |