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dfd2257a | 1 | /* Round double value to long long int. |
63551311 UD |
2 | Copyright (C) 1997 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. | |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Library General Public License as | |
8 | published by the Free Software Foundation; either version 2 of the | |
9 | License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Library General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Library General Public | |
17 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
18 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include <math.h> | |
22 | ||
23 | #include "math_private.h" | |
24 | ||
25 | ||
63551311 | 26 | long long int |
dfd2257a | 27 | __llround (double x) |
63551311 UD |
28 | { |
29 | int32_t j0; | |
30 | u_int32_t i1, i0; | |
31 | long long int result; | |
dfd2257a | 32 | int sign; |
63551311 UD |
33 | |
34 | EXTRACT_WORDS (i0, i1, x); | |
35 | j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; | |
dfd2257a UD |
36 | sign = (i0 & 0x80000000) != 0 ? -1 : 1; |
37 | i0 &= 0xfffff; | |
38 | i0 |= 0x100000; | |
39 | ||
63551311 UD |
40 | if (j0 < 20) |
41 | { | |
42 | if (j0 < 0) | |
dfd2257a | 43 | return j0 < -1 ? 0 : sign; |
63551311 UD |
44 | else |
45 | { | |
dfd2257a UD |
46 | i0 += 0x80000 >> j0; |
47 | ||
48 | result = i0 >> (20 - j0); | |
63551311 UD |
49 | } |
50 | } | |
cc3fa755 | 51 | else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) |
63551311 | 52 | { |
dfd2257a | 53 | if (j0 >= 52) |
cc3fa755 | 54 | result = (((long long int) i0 << 32) | i1) << (j0 - 52); |
dfd2257a | 55 | else |
63551311 | 56 | { |
63551311 UD |
57 | u_int32_t j = i1 + (0x80000000 >> (j0 - 20)); |
58 | if (j < i1) | |
dfd2257a | 59 | ++i0; |
63551311 | 60 | |
cc3fa755 UD |
61 | if (j0 == 20) |
62 | result = (long long int) i0; | |
63 | else | |
64 | result = ((long long int) i0 << (j0 - 20)) | (j >> (52 - j0)); | |
63551311 UD |
65 | } |
66 | } | |
dfd2257a | 67 | else |
63551311 UD |
68 | { |
69 | /* The number is too large. It is left implementation defined | |
70 | what happens. */ | |
dfd2257a | 71 | return (long long int) x; |
63551311 UD |
72 | } |
73 | ||
dfd2257a | 74 | return sign * result; |
63551311 | 75 | } |
dfd2257a | 76 | |
d705269e | 77 | weak_alias (__llround, llround) |
dfd2257a UD |
78 | #ifdef NO_LONG_DOUBLE |
79 | strong_alias (__llround, __llroundl) | |
80 | weak_alias (__llround, llroundl) | |
81 | #endif |