1 /* $NetBSD: lrint.c,v 1.5 2015/07/09 06:17:13 nat Exp $ */
5 * Matthias Drochner. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/ieee754.h>
31 #include <machine/limits.h>
32 #include "math_private.h"
35 #define LRINTNAME lrint
36 #define RESTYPE long int
37 #define RESTYPE_MIN LONG_MIN
38 #define RESTYPE_MAX LONG_MAX
41 #define RESTYPE_BITS (sizeof(RESTYPE) * 8)
45 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
46 -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
58 s
= (uint32_t)e
>> DBL_EXPBITS
;
59 e
= (e
& 0x7ff) - DBL_EXP_BIAS
;
61 /* 1.0 x 2^-1 is the smallest number which can be rounded to 1 */
64 /* 1.0 x 2^31 (or 2^63) is already too large */
65 if (e
>= (int)RESTYPE_BITS
- 1)
66 return (s
? RESTYPE_MIN
: RESTYPE_MAX
); /* ??? unspecified */
68 /* >= 2^52 is already an exact integer */
69 if (e
< DBL_FRACBITS
) {
70 /* round, using current direction */
76 EXTRACT_WORDS(i0
, i1
, x
);
77 e
= ((i0
>> 20) & 0x7ff) - DBL_EXP_BIAS
;
81 shift
= e
- DBL_FRACBITS
;
83 res
= (shift
< 32 ? (RESTYPE
)i1
<< shift
: 0);
85 res
= (shift
> -32 ? i1
>> -shift
: 0);
88 res
|= (shift
< 32 ? (RESTYPE
)i0
<< shift
: 0);
90 res
|= (shift
> -32 ? i0
>> -shift
: 0);
92 return (s
? -res
: res
);