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)