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git.ipfire.org Git - thirdparty/glibc.git/blob - sysdeps/ieee754/dbl-64/s_floor.c
1 /* Round double to integer away from zero.
2 Copyright (C) 2011-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
19 /* Based on a version which carries the following copyright: */
22 * ====================================================
23 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
25 * Developed at SunPro, a Sun Microsystems, Inc. business.
26 * Permission to use, copy, modify, and distribute this
27 * software is freely granted, provided that this notice
29 * ====================================================
32 #define NO_MATH_REDIRECT
34 #include <math_private.h>
36 #include <libm-alias-double.h>
37 #include <math-use-builtins.h>
41 * Return x rounded toward -inf to integral value
51 return __builtin_floor (x
);
53 /* Use generic implementation. */
55 EXTRACT_WORDS64 (i0
, x
);
56 int32_t j0
= ((i0
>> 52) & 0x7ff) - 0x3ff;
57 if (__glibc_likely (j0
< 52))
61 /* return 0 * sign (x) if |x| < 1 */
64 else if ((i0
& 0x7fffffffffffffffl
) != 0)
65 i0
= 0xbff0000000000000l
;
69 uint64_t i
= 0x000fffffffffffffl
>> j0
;
71 return x
; /* x is integral */
73 i0
+= 0x0010000000000000l
>> j0
;
76 INSERT_WORDS64 (x
, i0
);
79 return x
+ x
; /* inf or NaN */
81 #endif /* ! USE_FLOOR_BUILTIN */
84 libm_alias_double (__floor
, floor
)