1 /* Round argument to nearest integral value according to current rounding
2 direction.
3 Copyright (C) 1997-2018 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 <http://www.gnu.org/licenses/>. */
21
22 #include "quadmath-imp.h"
23
24 static const __float128 two112[2] =
25 {
26 5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
27 -5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
28 };
29
30 long long int
llrintq(__float128 x)31 llrintq (__float128 x)
32 {
33 int32_t j0;
34 uint64_t i0,i1;
35 __float128 w;
36 __float128 t;
37 long long int result;
38 int sx;
39
40 GET_FLT128_WORDS64 (i0, i1, x);
41 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
42 sx = i0 >> 63;
43 i0 &= 0x0000ffffffffffffLL;
44 i0 |= 0x0001000000000000LL;
45
46 if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
47 {
48 #if defined FE_INVALID || defined FE_INEXACT
49 /* X < LLONG_MAX + 1 implied by J0 < 63. */
50 if (x > (__float128) LLONG_MAX)
51 {
52 /* In the event of overflow we must raise the "invalid"
53 exception, but not "inexact". */
54 t = nearbyintq (x);
55 feraiseexcept (t == LLONG_MAX ? FE_INEXACT : FE_INVALID);
56 }
57 else
58 #endif
59 {
60 w = two112[sx] + x;
61 t = w - two112[sx];
62 }
63 GET_FLT128_WORDS64 (i0, i1, t);
64 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
65 i0 &= 0x0000ffffffffffffLL;
66 i0 |= 0x0001000000000000LL;
67
68 if (j0 < 0)
69 result = 0;
70 else if (j0 <= 48)
71 result = i0 >> (48 - j0);
72 else
73 result = ((long long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
74 }
75 else
76 {
77 /* The number is too large. Unless it rounds to LLONG_MIN,
78 FE_INVALID must be raised and the return value is
79 unspecified. */
80 #if defined FE_INVALID || defined FE_INEXACT
81 if (x < (__float128) LLONG_MIN
82 && x > (__float128) LLONG_MIN - 1)
83 {
84 /* If truncation produces LLONG_MIN, the cast will not raise
85 the exception, but may raise "inexact". */
86 t = nearbyintq (x);
87 feraiseexcept (t == LLONG_MIN ? FE_INEXACT : FE_INVALID);
88 return LLONG_MIN;
89 }
90 else if (FIX_FLT128_LLONG_CONVERT_OVERFLOW && x != (__float128) LLONG_MIN)
91 {
92 feraiseexcept (FE_INVALID);
93 return sx == 0 ? LLONG_MAX : LLONG_MIN;
94 }
95
96 #endif
97 return (long long int) x;
98 }
99
100 return sx ? -result : result;
101 }
102