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 int
32lrintq (__float128 x)
33{
34 int32_t j0;
35 uint64_t i0,i1;
36 __float128 w;
37 __float128 t;
38 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 int)) - 1)
48 {
49 if (j0 < 48)
50 {
51#if defined FE_INVALID || defined FE_INEXACT
52 /* X < LONG_MAX + 1 implied by J0 < 31. */
53 if (sizeof (long int) == 4
54 && x > (__float128) LONG_MAX)
55 {
56 /* In the event of overflow we must raise the "invalid"
57 exception, but not "inexact". */
58 t = nearbyintq (x);
59#ifdef USE_FENV_H
60 feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID);
61#endif
62 }
63 else
64#endif
65 {
66 w = two112[sx] + x;
67 t = w - two112[sx];
68 }
69 GET_FLT128_WORDS64 (i0, i1, t);
70 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
71 i0 &= 0x0000ffffffffffffLL;
72 i0 |= 0x0001000000000000LL;
73
74 result = (j0 < 0 ? 0 : i0 >> (48 - j0));
75 }
76 else if (j0 >= 112)
77 result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
78 else
79 {
80#if defined FE_INVALID || defined FE_INEXACT
81 /* X < LONG_MAX + 1 implied by J0 < 63. */
82 if (sizeof (long int) == 8
83 && x > (__float128) LONG_MAX)
84 {
85 /* In the event of overflow we must raise the "invalid"
86 exception, but not "inexact". */
87 t = nearbyintq (x);
88#ifdef USE_FENV_H
89 feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID);
90#endif
91 }
92 else
93#endif
94 {
95 w = two112[sx] + x;
96 t = w - two112[sx];
97 }
98 GET_FLT128_WORDS64 (i0, i1, t);
99 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
100 i0 &= 0x0000ffffffffffffLL;
101 i0 |= 0x0001000000000000LL;
102
103 if (j0 == 48)
104 result = (long int) i0;
105 else
106 result = ((long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
107 }
108 }
109 else
110 {
111 /* The number is too large. Unless it rounds to LONG_MIN,
112 FE_INVALID must be raised and the return value is
113 unspecified. */
114#if defined FE_INVALID || defined FE_INEXACT
115 if (x < (__float128) LONG_MIN
116 && x > (__float128) LONG_MIN - 1.0Q)
117 {
118 /* If truncation produces LONG_MIN, the cast will not raise
119 the exception, but may raise "inexact". */
120 t = nearbyintq (x);
121#ifdef USE_FENV_H
122 feraiseexcept (t == LONG_MIN ? FE_INEXACT : FE_INVALID);
123#endif
124 return LONG_MIN;
125 }
126#endif
127 return (long int) x;
128 }
129
130 return sx ? -result : result;
131}
132