1/* Round argument to nearest integral value according to current rounding
2 direction.
3 Copyright (C) 1997-2017 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, write to the Free
20 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 02111-1307 USA. */
22
23#include "quadmath-imp.h"
24
25static const __float128 two112[2] =
26{
27 5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
28 -5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
29};
30
31long long int
32llrintq (__float128 x)
33{
34 int32_t j0;
35 uint64_t i0,i1;
36 __float128 w;
37 __float128 t;
38 long long int result;
39 int sx;
40
41 GET_FLT128_WORDS64 (i0, i1, x);
42 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
43 sx = i0 >> 63;
44 i0 &= 0x0000ffffffffffffLL;
45 i0 |= 0x0001000000000000LL;
46
47 if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
48 {
49#if defined FE_INVALID || defined FE_INEXACT
50 /* X < LLONG_MAX + 1 implied by J0 < 63. */
51 if (x > (__float128) LLONG_MAX)
52 {
53 /* In the event of overflow we must raise the "invalid"
54 exception, but not "inexact". */
55 t = nearbyintq (x);
56#ifdef USE_FENV_H
57 feraiseexcept (t == LLONG_MAX ? FE_INEXACT : FE_INVALID);
58#endif
59 }
60 else
61#endif
62 {
63 w = two112[sx] + x;
64 t = w - two112[sx];
65 }
66 GET_FLT128_WORDS64 (i0, i1, t);
67 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
68 i0 &= 0x0000ffffffffffffLL;
69 i0 |= 0x0001000000000000LL;
70
71 if (j0 < 0)
72 result = 0;
73 else if (j0 <= 48)
74 result = i0 >> (48 - j0);
75 else
76 result = ((long long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
77 }
78 else
79 {
80 /* The number is too large. Unless it rounds to LLONG_MIN,
81 FE_INVALID must be raised and the return value is
82 unspecified. */
83#if defined FE_INVALID || defined FE_INEXACT
84 if (x < (__float128) LLONG_MIN
85 && x > (__float128) LLONG_MIN - 1.0Q)
86 {
87 /* If truncation produces LLONG_MIN, the cast will not raise
88 the exception, but may raise "inexact". */
89 t = nearbyintq (x);
90#ifdef USE_FENV_H
91 feraiseexcept (t == LLONG_MIN ? FE_INEXACT : FE_INVALID);
92#endif
93 return LLONG_MIN;
94 }
95
96#endif
97
98 /* The number is too large. It is left implementation defined
99 what happens. */
100 return (long long int) x;
101 }
102
103 return sx ? -result : result;
104}
105