1 /* Ceil (round to +inf) long double floating-point values.
2 IBM extended format long double version.
3 Copyright (C) 2006, 2007 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
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.
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.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 #include <math_ldbl_opt.h>
29 __ceill (long double x
)
36 double xh
, xl
, hi
, lo
;
38 ldbl_unpack (x
, &xh
, &xl
);
40 /* Return Inf, Nan, +/-0 unchanged. */
41 if (__builtin_expect (xh
!= 0.0
42 && __builtin_isless (__builtin_fabs (xh
),
43 __builtin_inf ()), 1))
47 /* Long double arithmetic, including the canonicalisation below,
48 only works in round-to-nearest mode. */
50 /* Convert the high double to integer. */
52 hi
= ldbl_nearbyint (xh
);
54 /* Subtract integral high part from the value. */
56 ldbl_canonicalize (&xh
, &xl
);
58 /* Now convert the low double, adjusted for any remainder from the
60 lo
= ldbl_nearbyint (xh
);
62 /* Adjust the result when the remainder is non-zero. nearbyint
63 rounds values to the nearest integer, and values halfway
64 between integers to the nearest even integer. ceill must
65 round towards +Inf. */
67 ldbl_canonicalize (&xh
, &xl
);
69 if (xh
> 0.0 || (xh
== 0.0 && xl
> 0.0))
72 /* Ensure the final value is canonical. In certain cases,
73 rounding causes hi,lo calculated so far to be non-canonical. */
76 ldbl_canonicalize (&xh
, &xl
);
78 /* Ensure we return -0 rather than +0 when appropriate. */
80 xh
= -__builtin_fabs (xh
);
83 return ldbl_pack (xh
, xl
);
86 long_double_symbol (libm
, __ceill
, ceill
);