1/* Round __float128 value to long int.
2 Copyright (C) 1997-2017 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, write to the Free
19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 02111-1307 USA. */
21
22#include "quadmath-imp.h"
23
24
25long int
26lroundq (__float128 x)
27{
28 int64_t j0;
29 uint64_t i1, i0;
30 long int result;
31 int sign;
32
33 GET_FLT128_WORDS64 (i0, i1, x);
34 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
35 sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1;
36 i0 &= 0x0000ffffffffffffLL;
37 i0 |= 0x0001000000000000LL;
38
39 if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
40 {
41 if (j0 < 48)
42 {
43 if (j0 < 0)
44 return j0 < -1 ? 0 : sign;
45 else
46 {
47 i0 += 0x0000800000000000LL >> j0;
48 result = i0 >> (48 - j0);
49#if defined FE_INVALID && defined USE_FENV_H
50 if (sizeof (long int) == 4
51 && sign == 1
52 && result == LONG_MIN)
53 /* Rounding brought the value out of range. */
54 feraiseexcept (FE_INVALID);
55#endif
56 }
57 }
58 else if (j0 >= 112)
59 result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
60 else
61 {
62 uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48));
63 if (j < i1)
64 ++i0;
65
66 if (j0 == 48)
67 result = (long int) i0;
68 else
69 {
70 result = ((long int) i0 << (j0 - 48)) | (j >> (112 - j0));
71#if defined FE_INVALID && defined USE_FENV_H
72 if (sizeof (long int) == 8
73 && sign == 1
74 && result == LONG_MIN)
75 /* Rounding brought the value out of range. */
76 feraiseexcept (FE_INVALID);
77#endif
78 }
79 }
80 }
81 else
82 {
83 /* The number is too large. Unless it rounds to LONG_MIN,
84 FE_INVALID must be raised and the return value is
85 unspecified. */
86#ifdef FE_INVALID
87 if (x <= (__float128) LONG_MIN - 0.5Q)
88 {
89 /* If truncation produces LONG_MIN, the cast will not raise
90 the exception, but may raise "inexact". */
91#ifdef USE_FENV_H
92 feraiseexcept (FE_INVALID);
93#endif
94 return LONG_MIN;
95 }
96#endif
97 return (long int) x;
98 }
99
100 return sign * result;
101}
102