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4a2f7ea2 | 1 | /* Round __float128 to integer away from zero. |
92920cc6 | 2 | Copyright (C) 1997, 1999 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 | |
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 | static const __float128 huge = 1.0E4930Q; | |
25 | ||
26 | ||
27 | __float128 | |
28 | roundq (__float128 x) | |
29 | { | |
30 | int32_t j0; | |
31 | uint64_t i1, i0; | |
32 | ||
33 | GET_FLT128_WORDS64 (i0, i1, x); | |
34 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; | |
35 | if (j0 < 31) | |
36 | { | |
37 | if (j0 < 0) | |
38 | { | |
39 | if (huge + x > 0.0) | |
40 | { | |
41 | i0 &= 0x8000000000000000ULL; | |
42 | if (j0 == -1) | |
43 | i0 |= 0x3fff000000000000LL; | |
44 | i1 = 0; | |
45 | } | |
46 | } | |
47 | else | |
48 | { | |
49 | uint64_t i = 0x0000ffffffffffffLL >> j0; | |
50 | if (((i0 & i) | i1) == 0) | |
51 | /* X is integral. */ | |
52 | return x; | |
53 | if (huge + x > 0.0) | |
54 | { | |
55 | /* Raise inexact if x != 0. */ | |
56 | i0 += 0x0000800000000000LL >> j0; | |
57 | i0 &= ~i; | |
58 | i1 = 0; | |
59 | } | |
60 | } | |
61 | } | |
62 | else if (j0 > 111) | |
63 | { | |
64 | if (j0 == 0x4000) | |
65 | /* Inf or NaN. */ | |
66 | return x + x; | |
67 | else | |
68 | return x; | |
69 | } | |
70 | else | |
71 | { | |
72 | uint64_t i = -1ULL >> (j0 - 48); | |
73 | if ((i1 & i) == 0) | |
74 | /* X is integral. */ | |
75 | return x; | |
76 | ||
77 | if (huge + x > 0.0) | |
78 | { | |
79 | /* Raise inexact if x != 0. */ | |
80 | uint64_t j = i1 + (1LL << (111 - j0)); | |
81 | if (j < i1) | |
82 | i0 += 1; | |
83 | i1 = j; | |
84 | } | |
85 | i1 &= ~i; | |
86 | } | |
87 | ||
88 | SET_FLT128_WORDS64 (x, i0, i1); | |
89 | return x; | |
90 | } |