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comparison libquadmath/math/lrintq.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 argument to nearest integral value according to current rounding
2 direction.
3 Copyright (C) 1997, 1999, 2004, 2006 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
25 static const __float128 two112[2] =
26 {
27 5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
28 -5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
29 };
30
31 long int
32 lrintq (__float128 x)
33 {
34 int32_t j0;
35 uint64_t i0,i1;
36 volatile __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 < 48)
48 {
49 w = two112[sx] + x;
50 t = w - two112[sx];
51 GET_FLT128_WORDS64 (i0, i1, t);
52 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
53 i0 &= 0x0000ffffffffffffLL;
54 i0 |= 0x0001000000000000LL;
55
56 result = (j0 < 0 ? 0 : i0 >> (48 - j0));
57 }
58 else if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
59 {
60 if (j0 >= 112)
61 result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
62 else
63 {
64 w = two112[sx] + x;
65 t = w - two112[sx];
66 GET_FLT128_WORDS64 (i0, i1, t);
67 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
68 i0 &= 0x0000ffffffffffffLL;
69 i0 |= 0x0001000000000000LL;
70
71 if (j0 == 48)
72 result = (long int) i0;
73 else
74 result = ((long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
75 }
76 }
77 else
78 {
79 /* The number is too large. It is left implementation defined
80 what happens. */
81 return (long int) x;
82 }
83
84 return sx ? -result : result;
85 }