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1 | /* Round to int long double floating-point values. |
2 | IBM extended format long double version. | |
d4697bc9 | 3 | Copyright (C) 2006-2014 Free Software Foundation, Inc. |
f964490f RM |
4 | This file is part of the GNU C Library. |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the 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 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
f964490f | 19 | |
f964490f | 20 | #include <math.h> |
f964490f RM |
21 | #include <math_ldbl_opt.h> |
22 | #include <float.h> | |
23 | #include <ieee754.h> | |
24 | ||
25 | ||
f964490f RM |
26 | long double |
27 | __floorl (long double x) | |
f964490f | 28 | { |
5c68d401 | 29 | double xh, xl, hi, lo; |
f964490f | 30 | |
5c68d401 | 31 | ldbl_unpack (x, &xh, &xl); |
f964490f | 32 | |
5c68d401 RM |
33 | /* Return Inf, Nan, +/-0 unchanged. */ |
34 | if (__builtin_expect (xh != 0.0 | |
35 | && __builtin_isless (__builtin_fabs (xh), | |
36 | __builtin_inf ()), 1)) | |
16f0eced | 37 | { |
5c68d401 RM |
38 | /* Long double arithmetic, including the canonicalisation below, |
39 | only works in round-to-nearest mode. */ | |
5c68d401 RM |
40 | |
41 | /* Convert the high double to integer. */ | |
42 | hi = ldbl_nearbyint (xh); | |
43 | ||
44 | /* Subtract integral high part from the value. */ | |
45 | xh -= hi; | |
46 | ldbl_canonicalize (&xh, &xl); | |
47 | ||
48 | /* Now convert the low double, adjusted for any remainder from the | |
49 | high double. */ | |
50 | lo = ldbl_nearbyint (xh); | |
51 | ||
52 | /* Adjust the result when the remainder is non-zero. nearbyint | |
53 | rounds values to the nearest integer, and values halfway | |
54 | between integers to the nearest even integer. floorl must | |
55 | round towards -Inf. */ | |
56 | xh -= lo; | |
57 | ldbl_canonicalize (&xh, &xl); | |
58 | ||
59 | if (xh < 0.0 || (xh == 0.0 && xl < 0.0)) | |
60 | lo += -1.0; | |
61 | ||
62 | /* Ensure the final value is canonical. In certain cases, | |
63 | rounding causes hi,lo calculated so far to be non-canonical. */ | |
64 | xh = hi; | |
65 | xl = lo; | |
66 | ldbl_canonicalize (&xh, &xl); | |
f964490f RM |
67 | } |
68 | ||
5c68d401 | 69 | return ldbl_pack (xh, xl); |
f964490f RM |
70 | } |
71 | ||
72 | long_double_symbol (libm, __floorl, floorl); |