1 /* Round to long int long double floating-point values.
2 IBM extended format long double version.
3 Copyright (C) 2006-2023 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, see
18 <https://www.gnu.org/licenses/>. */
22 #include <math_private.h>
23 #include <math_ldbl_opt.h>
28 __lroundl (long double x
)
33 ldbl_unpack (x
, &xh
, &xl
);
35 /* Limit the range of values handled by the conversion to long.
36 We do this because we aren't sure whether that conversion properly
39 #if __LONG_MAX__ == 2147483647
41 ((__builtin_fabs (xh
) <= (double) __LONG_MAX__
+ 2), 1)
44 ((__builtin_fabs (xh
) <= -(double) (-__LONG_MAX__
- 1)), 1)
46 #if !defined (FE_INVALID)
51 #if __LONG_MAX__ == 2147483647
52 long long llhi
= (long long) xh
;
53 if (llhi
!= (long) llhi
)
54 hi
= llhi
< 0 ? -__LONG_MAX__
- 1 : __LONG_MAX__
;
59 if (__glibc_unlikely ((xh
== -(double) (-__LONG_MAX__
- 1))))
61 /* When XH is 9223372036854775808.0, converting to long long will
62 overflow, resulting in an invalid operation. However, XL might
63 be negative and of sufficient magnitude that the overall long
64 double is in fact in range. Avoid raising an exception. In any
65 case we need to convert this value specially, because
66 the converted value is not exactly represented as a double
67 thus subtracting HI from XH suffers rounding error. */
77 ldbl_canonicalize (&xh
, &xl
);
81 /* Peg at max/min values, assuming that the above conversions do so.
82 Strictly speaking, we can return anything for values that overflow,
83 but this is more useful. */
84 res
= (long int) ((unsigned long int) hi
+ (unsigned long int) lo
);
86 /* This is just sign(hi) == sign(lo) && sign(res) != sign(hi). */
87 if (__glibc_unlikely (((~(hi
^ lo
) & (res
^ hi
)) < 0)))
91 ldbl_canonicalize (&xh
, &xl
);
100 if (xl
> 0.0 || (xl
== 0.0 && res
>= 0))
109 if (xl
< 0.0 || (xl
== 0.0 && res
<= 0))
113 if (__glibc_unlikely (((~(hi
^ (res
- hi
)) & (res
^ hi
)) < 0)))
123 hi
= -__LONG_MAX__
- 1;
131 feraiseexcept (FE_INVALID
);
136 long_double_symbol (libm
, __lroundl
, lroundl
);