1/* Round long double value to long long int.
2 Copyright (C) 1997-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <fenv.h>
20#include <limits.h>
21#include <math.h>
22
23#include <math_private.h>
24#include <libm-alias-ldouble.h>
25#include <fix-fp-int-convert-overflow.h>
26
27long long int
28__llroundl (_Float128 x)
29{
30 int64_t j0;
31 uint64_t i1, i0;
32 long long int result;
33 int sign;
34
35 GET_LDOUBLE_WORDS64 (i0, i1, x);
36 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
37 sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1;
38 i0 &= 0x0000ffffffffffffLL;
39 i0 |= 0x0001000000000000LL;
40
41 if (j0 < 48)
42 {
43 if (j0 < 0)
44 return j0 < -1 ? 0 : sign;
45 else
46 {
47 i0 += 0x0000800000000000LL >> j0;
48 result = i0 >> (48 - j0);
49 }
50 }
51 else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
52 {
53 if (j0 >= 112)
54 result = ((long long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
55 else
56 {
57 uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48));
58 if (j < i1)
59 ++i0;
60
61 if (j0 == 48)
62 result = (long long int) i0;
63 else
64 {
65 result = ((long long int) i0 << (j0 - 48)) | (j >> (112 - j0));
66#ifdef FE_INVALID
67 if (sign == 1 && result == LLONG_MIN)
68 /* Rounding brought the value out of range. */
69 feraiseexcept (FE_INVALID);
70#endif
71 }
72 }
73 }
74 else
75 {
76 /* The number is too large. Unless it rounds to LLONG_MIN,
77 FE_INVALID must be raised and the return value is
78 unspecified. */
79#ifdef FE_INVALID
80 if (FIX_LDBL_LLONG_CONVERT_OVERFLOW
81 && !(sign == -1 && x > (_Float128) LLONG_MIN - L(0.5)))
82 {
83 feraiseexcept (FE_INVALID);
84 return sign == 1 ? LLONG_MAX : LLONG_MIN;
85 }
86 else if (!FIX_LDBL_LLONG_CONVERT_OVERFLOW
87 && x <= (_Float128) LLONG_MIN - L(0.5))
88 {
89 /* If truncation produces LLONG_MIN, the cast will not raise
90 the exception, but may raise "inexact". */
91 feraiseexcept (FE_INVALID);
92 return LLONG_MIN;
93 }
94#endif
95 return (long long int) x;
96 }
97
98 return sign * result;
99}
100
101libm_alias_ldouble (__llround, llround)
102