1 /* Truncate argument to nearest integral value not larger than the argument.
2 Copyright (C) 1997-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
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.
9
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.
14
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/>. */
18
19 #define NO_MATH_REDIRECT
20 #include <math.h>
21
22 #include <math_private.h>
23 #include <libm-alias-ldouble.h>
24 #include <math-use-builtins.h>
25
26
27 _Float128
__truncl(_Float128 x)28 __truncl (_Float128 x)
29 {
30 #if USE_TRUNCL_BUILTIN
31 return __builtin_truncl (x);
32 #else
33 /* Use generic implementation. */
34 int32_t j0;
35 uint64_t i0, i1, sx;
36
37 GET_LDOUBLE_WORDS64 (i0, i1, x);
38 sx = i0 & 0x8000000000000000ULL;
39 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
40 if (j0 < 48)
41 {
42 if (j0 < 0)
43 /* The magnitude of the number is < 1 so the result is +-0. */
44 SET_LDOUBLE_WORDS64 (x, sx, 0);
45 else
46 SET_LDOUBLE_WORDS64 (x, i0 & ~(0x0000ffffffffffffLL >> j0), 0);
47 }
48 else if (j0 > 111)
49 {
50 if (j0 == 0x4000)
51 /* x is inf or NaN. */
52 return x + x;
53 }
54 else
55 {
56 SET_LDOUBLE_WORDS64 (x, i0, i1 & ~(0xffffffffffffffffULL >> (j0 - 48)));
57 }
58
59 return x;
60 #endif /* ! USE_TRUNCL_BUILTIN */
61 }
62 libm_alias_ldouble (__trunc, trunc)
63