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comparison libquadmath/math/llroundq.c @ 68:561a7518be6b

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update gcc-4.6
author Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
date Sun, 21 Aug 2011 07:07:55 +0900
parents
children 04ced10e8804
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67:f6334be47118 68:561a7518be6b
1 /* Round long double value to long long int.
2 Copyright (C) 1997, 1999, 2004 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 long int
26 llroundq (__float128 x)
27 {
28 int64_t j0;
29 uint64_t i1, i0;
30 long 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 < 48)
40 {
41 if (j0 < 0)
42 return j0 < -1 ? 0 : sign;
43 else
44 {
45 i0 += 0x0000800000000000LL >> j0;
46 result = i0 >> (48 - j0);
47 }
48 }
49 else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
50 {
51 if (j0 >= 112)
52 result = ((long long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
53 else
54 {
55 uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48));
56 if (j < i1)
57 ++i0;
58
59 if (j0 == 48)
60 result = (long long int) i0;
61 else
62 result = ((long long int) i0 << (j0 - 48)) | (j >> (112 - j0));
63 }
64 }
65 else
66 {
67 /* The number is too large. It is left implementation defined
68 what happens. */
69 return (long long int) x;
70 }
71
72 return sign * result;
73 }