1/* Truncate (toward zero) long double floating-point values.
2 IBM extended format long double version.
3 Copyright (C) 2006-2024 Free Software Foundation, Inc.
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
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#define NO_MATH_REDIRECT
21#include <math.h>
22#include <math_private.h>
23#include <math_ldbl_opt.h>
24#include <float.h>
25#include <ieee754.h>
26
27double ceil (double) asm ("__ceil");
28double floor (double) asm ("__floor");
29double trunc (double) asm ("__trunc");
30
31
32long double
33__truncl (long double x)
34{
35 double xh, xl, hi, lo;
36
37 ldbl_unpack (x, &xh, &xl);
38
39 /* Return Inf, Nan, +/-0 unchanged. */
40 if (__builtin_expect (xh != 0.0
41 && __builtin_isless (__builtin_fabs (xh),
42 __builtin_inf ()), 1))
43 {
44 hi = trunc (xh);
45 if (hi != xh)
46 {
47 /* The high part is not an integer; the low part does not
48 affect the result. */
49 xh = hi;
50 xl = 0;
51 }
52 else
53 {
54 /* The high part is a nonzero integer. */
55 lo = xh > 0 ? floor (xl) : ceil (xl);
56 xh = hi;
57 xl = lo;
58 ldbl_canonicalize_int (&xh, &xl);
59 }
60 }
61 else
62 /* Quiet signaling NaN arguments. */
63 xh += xh;
64
65 return ldbl_pack (xh, xl);
66}
67
68long_double_symbol (libm, __truncl, truncl);
69

source code of glibc/sysdeps/ieee754/ldbl-128ibm/s_truncl.c