]>
Commit | Line | Data |
---|---|---|
e409716d | 1 | /* Round long double value to long int. |
2 | Copyright (C) 1997-2018 Free Software Foundation, Inc. | |
87969c8c | 3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and | |
c98f0ea6 | 5 | Jakub Jelinek <jj@ultra.linux.cz>, 1999. |
87969c8c | 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 | |
e409716d | 18 | License along with the GNU C Library; if not, see |
19 | <http://www.gnu.org/licenses/>. */ | |
87969c8c | 20 | |
21 | #include "quadmath-imp.h" | |
22 | ||
87969c8c | 23 | long int |
24 | lroundq (__float128 x) | |
25 | { | |
26 | int64_t j0; | |
27 | uint64_t i1, i0; | |
28 | long int result; | |
29 | int sign; | |
30 | ||
31 | GET_FLT128_WORDS64 (i0, i1, x); | |
32 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; | |
33 | sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1; | |
34 | i0 &= 0x0000ffffffffffffLL; | |
35 | i0 |= 0x0001000000000000LL; | |
36 | ||
c98f0ea6 | 37 | if (j0 < (int32_t) (8 * sizeof (long int)) - 1) |
87969c8c | 38 | { |
c98f0ea6 | 39 | if (j0 < 48) |
87969c8c | 40 | { |
c98f0ea6 | 41 | if (j0 < 0) |
42 | return j0 < -1 ? 0 : sign; | |
43 | else | |
44 | { | |
45 | i0 += 0x0000800000000000LL >> j0; | |
46 | result = i0 >> (48 - j0); | |
e409716d | 47 | #ifdef FE_INVALID |
c98f0ea6 | 48 | if (sizeof (long int) == 4 |
49 | && sign == 1 | |
50 | && result == LONG_MIN) | |
51 | /* Rounding brought the value out of range. */ | |
52 | feraiseexcept (FE_INVALID); | |
53 | #endif | |
54 | } | |
87969c8c | 55 | } |
c98f0ea6 | 56 | else if (j0 >= 112) |
87969c8c | 57 | result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112)); |
58 | else | |
59 | { | |
60 | uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48)); | |
61 | if (j < i1) | |
62 | ++i0; | |
63 | ||
64 | if (j0 == 48) | |
65 | result = (long int) i0; | |
66 | else | |
c98f0ea6 | 67 | { |
68 | result = ((long int) i0 << (j0 - 48)) | (j >> (112 - j0)); | |
e409716d | 69 | #ifdef FE_INVALID |
c98f0ea6 | 70 | if (sizeof (long int) == 8 |
71 | && sign == 1 | |
72 | && result == LONG_MIN) | |
73 | /* Rounding brought the value out of range. */ | |
74 | feraiseexcept (FE_INVALID); | |
75 | #endif | |
76 | } | |
87969c8c | 77 | } |
78 | } | |
79 | else | |
80 | { | |
c98f0ea6 | 81 | /* The number is too large. Unless it rounds to LONG_MIN, |
82 | FE_INVALID must be raised and the return value is | |
83 | unspecified. */ | |
84 | #ifdef FE_INVALID | |
e409716d | 85 | if (FIX_FLT128_LONG_CONVERT_OVERFLOW |
86 | && !(sign == -1 && x > (__float128) LONG_MIN - 0.5Q)) | |
87 | { | |
88 | feraiseexcept (FE_INVALID); | |
89 | return sign == 1 ? LONG_MAX : LONG_MIN; | |
90 | } | |
91 | else if (!FIX_FLT128_LONG_CONVERT_OVERFLOW | |
92 | && x <= (__float128) LONG_MIN - 0.5Q) | |
c98f0ea6 | 93 | { |
94 | /* If truncation produces LONG_MIN, the cast will not raise | |
95 | the exception, but may raise "inexact". */ | |
c98f0ea6 | 96 | feraiseexcept (FE_INVALID); |
c98f0ea6 | 97 | return LONG_MIN; |
98 | } | |
99 | #endif | |
e409716d | 100 | /* The number is too large. It is left implementation defined |
101 | what happens. */ | |
87969c8c | 102 | return (long int) x; |
103 | } | |
104 | ||
105 | return sign * result; | |
106 | } |