1/* Round argument to nearest integral value according to current rounding
2 direction.
3 Copyright (C) 1997-2021 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
6 Jakub Jelinek <jj@ultra.linux.cz>, 1999.
7
8 The GNU C Library is free software; you can redistribute it and/or
9 modify it under the terms of the GNU Lesser General Public
10 License as published by the Free Software Foundation; either
11 version 2.1 of the License, or (at your option) any later version.
12
13 The GNU C Library is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
17
18 You should have received a copy of the GNU Lesser General Public
19 License along with the GNU C Library; if not, see
20 <https://www.gnu.org/licenses/>. */
21
22#include <fenv.h>
23#include <limits.h>
24#include <math.h>
25
26#include <math_private.h>
27#include <libm-alias-ldouble.h>
28#include <fix-fp-int-convert-overflow.h>
29
30static const _Float128 two112[2] =
31{
32 L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */
33 L(-5.19229685853482762853049632922009600E+33) /* 0xC06F000000000000, 0 */
34};
35
36long int
37__lrintl (_Float128 x)
38{
39 int32_t j0;
40 uint64_t i0,i1;
41 _Float128 w;
42 _Float128 t;
43 long int result;
44 int sx;
45
46 GET_LDOUBLE_WORDS64 (i0, i1, x);
47 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
48 sx = i0 >> 63;
49 i0 &= 0x0000ffffffffffffLL;
50 i0 |= 0x0001000000000000LL;
51
52 if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
53 {
54 if (j0 < 48)
55 {
56#if defined FE_INVALID || defined FE_INEXACT
57 /* X < LONG_MAX + 1 implied by J0 < 31. */
58 if (sizeof (long int) == 4
59 && x > (_Float128) LONG_MAX)
60 {
61 /* In the event of overflow we must raise the "invalid"
62 exception, but not "inexact". */
63 t = __nearbyintl (x);
64 feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID);
65 }
66 else
67#endif
68 {
69 w = two112[sx] + x;
70 t = w - two112[sx];
71 }
72 GET_LDOUBLE_WORDS64 (i0, i1, t);
73 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
74 i0 &= 0x0000ffffffffffffLL;
75 i0 |= 0x0001000000000000LL;
76
77 result = (j0 < 0 ? 0 : i0 >> (48 - j0));
78 }
79 else if (j0 >= 112)
80 result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
81 else
82 {
83#if defined FE_INVALID || defined FE_INEXACT
84 /* X < LONG_MAX + 1 implied by J0 < 63. */
85 if (sizeof (long int) == 8
86 && x > (_Float128) LONG_MAX)
87 {
88 /* In the event of overflow we must raise the "invalid"
89 exception, but not "inexact". */
90 t = __nearbyintl (x);
91 feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID);
92 }
93 else
94#endif
95 {
96 w = two112[sx] + x;
97 t = w - two112[sx];
98 }
99 GET_LDOUBLE_WORDS64 (i0, i1, t);
100 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
101 i0 &= 0x0000ffffffffffffLL;
102 i0 |= 0x0001000000000000LL;
103
104 if (j0 == 48)
105 result = (long int) i0;
106 else
107 result = ((long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
108 }
109 }
110 else
111 {
112 /* The number is too large. Unless it rounds to LONG_MIN,
113 FE_INVALID must be raised and the return value is
114 unspecified. */
115#if defined FE_INVALID || defined FE_INEXACT
116 if (x < (_Float128) LONG_MIN
117 && x > (_Float128) LONG_MIN - 1)
118 {
119 /* If truncation produces LONG_MIN, the cast will not raise
120 the exception, but may raise "inexact". */
121 t = __nearbyintl (x);
122 feraiseexcept (t == LONG_MIN ? FE_INEXACT : FE_INVALID);
123 return LONG_MIN;
124 }
125 else if (FIX_LDBL_LONG_CONVERT_OVERFLOW && x != (_Float128) LONG_MIN)
126 {
127 feraiseexcept (FE_INVALID);
128 return sx == 0 ? LONG_MAX : LONG_MIN;
129 }
130
131#endif
132 return (long int) x;
133 }
134
135 return sx ? -result : result;
136}
137
138libm_alias_ldouble (__lrint, lrint)
139