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dfd2257a UD |
1 | /* Round argument to nearest integral value according to current rounding |
2 | direction. | |
0ecb606c | 3 | Copyright (C) 1997, 2006 Free Software Foundation, Inc. |
dfd2257a UD |
4 | This file is part of the GNU C Library. |
5 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
6 | ||
7 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
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. | |
dfd2257a UD |
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 | |
41bdb6e2 | 15 | Lesser General Public License for more details. |
dfd2257a | 16 | |
41bdb6e2 AJ |
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. */ | |
dfd2257a UD |
21 | |
22 | #include <math.h> | |
23 | ||
24 | #include "math_private.h" | |
25 | ||
0ecb606c | 26 | static const float two23[2] = |
dfd2257a UD |
27 | { |
28 | 8.3886080000e+06, /* 0x4B000000 */ | |
29 | -8.3886080000e+06, /* 0xCB000000 */ | |
30 | }; | |
31 | ||
32 | ||
33 | long int | |
34 | __lrintf (float x) | |
35 | { | |
36 | int32_t j0; | |
6973fc01 | 37 | u_int32_t i0; |
dfd2257a UD |
38 | volatile float w; |
39 | float t; | |
40 | long int result; | |
41 | int sx; | |
42 | ||
6973fc01 | 43 | GET_FLOAT_WORD (i0, x); |
dfd2257a UD |
44 | |
45 | sx = i0 >> 31; | |
46 | j0 = ((i0 >> 23) & 0xff) - 0x7f; | |
6973fc01 | 47 | i0 &= 0x7fffff; |
dfd2257a UD |
48 | i0 |= 0x800000; |
49 | ||
cc3fa755 | 50 | if (j0 < (int32_t) (sizeof (long int) * 8) - 1) |
dfd2257a | 51 | { |
0ecb606c | 52 | if (j0 >= 23) |
dfd2257a UD |
53 | result = (long int) i0 << (j0 - 23); |
54 | else | |
55 | { | |
56 | w = two23[sx] + x; | |
57 | t = w - two23[sx]; | |
6973fc01 | 58 | GET_FLOAT_WORD (i0, t); |
dfd2257a | 59 | j0 = ((i0 >> 23) & 0xff) - 0x7f; |
6973fc01 UD |
60 | i0 &= 0x7fffff; |
61 | i0 |= 0x800000; | |
dfd2257a | 62 | |
0ecb606c | 63 | result = (j0 < 0 ? 0 : i0 >> (23 - j0)); |
dfd2257a UD |
64 | } |
65 | } | |
66 | else | |
67 | { | |
68 | /* The number is too large. It is left implementation defined | |
69 | what happens. */ | |
70 | return (long int) x; | |
71 | } | |
72 | ||
73 | return sx ? -result : result; | |
74 | } | |
75 | ||
76 | weak_alias (__lrintf, lrintf) |