1 /* Round double value to long int.
2 Copyright (C) 1997-2018 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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 <http://www.gnu.org/licenses/>. */
24 #include <math_private.h>
25 #include <libm-alias-double.h>
26 #include <fix-fp-int-convert-overflow.h>
37 EXTRACT_WORDS (i0
, i1
, x
);
38 j0
= ((i0
>> 20) & 0x7ff) - 0x3ff;
39 sign
= (i0
& 0x80000000) != 0 ? -1 : 1;
46 return j0
< -1 ? 0 : sign
;
51 result
= i0
>> (20 - j0
);
54 else if (j0
< (int32_t) (8 * sizeof (long int)) - 1)
57 result
= ((long int) i0
<< (j0
- 20)) | ((long int) i1
<< (j0
- 52));
60 uint32_t j
= i1
+ (0x80000000 >> (j0
- 20));
65 result
= (long int) i0
;
68 result
= ((long int) i0
<< (j0
- 20)) | (j
>> (52 - j0
));
70 if (sizeof (long int) == 4
72 && result
== LONG_MIN
)
73 /* Rounding brought the value out of range. */
74 feraiseexcept (FE_INVALID
);
81 /* The number is too large. Unless it rounds to LONG_MIN,
82 FE_INVALID must be raised and the return value is
85 if (FIX_DBL_LONG_CONVERT_OVERFLOW
87 && (sizeof (long int) == 4
88 ? x
> (double) LONG_MIN
- 0.5
89 : x
>= (double) LONG_MIN
)))
91 feraiseexcept (FE_INVALID
);
92 return sign
== 1 ? LONG_MAX
: LONG_MIN
;
94 else if (!FIX_DBL_LONG_CONVERT_OVERFLOW
95 && sizeof (long int) == 4
96 && x
<= (double) LONG_MIN
- 0.5)
98 /* If truncation produces LONG_MIN, the cast will not raise
99 the exception, but may raise "inexact". */
100 feraiseexcept (FE_INVALID
);
107 return sign
* result
;
110 libm_alias_double (__lround
, lround
)