1/* Round long double value to long long int.
2 Copyright (C) 1997-2020 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
29long 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
103libm_alias_ldouble (__llround, llround)
104