Use round-to-nearest internally in jn, test with ALL_RM_TEST (bug 18602).
[glibc.git] / sysdeps / ieee754 / ldbl-96 / s_lrintl.c
blob96c6a5ea7dfb8c32f3c7212a2734891d0b5ad759
1 /* Round argument to nearest integral value according to current rounding
2 direction.
3 Copyright (C) 1997-2015 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
7 The GNU C Library is free software; you can redistribute it and/or
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.
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
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
21 #include <math.h>
23 #include <math_private.h>
25 static const long double two63[2] =
27 9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */
28 -9.223372036854775808000000e+18 /* 0xC03E, 0x00000000, 0x00000000 */
32 long int
33 __lrintl (long double x)
35 int32_t se,j0;
36 u_int32_t i0, i1;
37 long int result;
38 volatile long double w;
39 long double t;
40 int sx;
42 GET_LDOUBLE_WORDS (se, i0, i1, x);
44 sx = (se >> 15) & 1;
45 j0 = (se & 0x7fff) - 0x3fff;
47 if (j0 < 31)
49 w = two63[sx] + x;
50 t = w - two63[sx];
51 GET_LDOUBLE_WORDS (se, i0, i1, t);
52 j0 = (se & 0x7fff) - 0x3fff;
54 result = (j0 < 0 ? 0 : i0 >> (31 - j0));
56 else if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
58 if (j0 >= 63)
59 result = ((long int) i0 << (j0 - 31)) | (i1 << (j0 - 63));
60 else
62 w = two63[sx] + x;
63 t = w - two63[sx];
64 GET_LDOUBLE_WORDS (se, i0, i1, t);
65 j0 = (se & 0x7fff) - 0x3fff;
67 if (j0 == 31)
68 result = (long int) i0;
69 else
70 result = ((long int) i0 << (j0 - 31)) | (i1 >> (63 - j0));
73 else
75 /* The number is too large. It is left implementation defined
76 what happens. */
77 return (long int) x;
80 return sx ? -result : result;
83 weak_alias (__lrintl, lrintl)