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 | |
25 | long int |
26 | lroundq (__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 | |