3 * Matthias Drochner. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $NetBSD: lroundf.c,v 1.2 2004/10/13 15:18:32 drochner Exp $
27 * $DragonFly: src/lib/libm/src/lroundf.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
31 #include <sys/ieee754.h>
32 #include <machine/limits.h>
33 #include "math_private.h"
36 #define LROUNDNAME lroundf
37 #define RESTYPE long int
38 #define RESTYPE_MIN LONG_MIN
39 #define RESTYPE_MAX LONG_MAX
42 #define RESTYPE_BITS (sizeof(RESTYPE) * 8)
51 GET_FLOAT_WORD(i0
, x
);
52 e
= i0
>> SNG_FRACBITS
;
54 e
= (e
& 0xff) - SNG_EXP_BIAS
;
56 /* 1.0 x 2^-1 is the smallest number which can be rounded to 1 */
59 /* 1.0 x 2^31 (or 2^63) is already too large */
60 if (e
>= (int)RESTYPE_BITS
- 1)
61 return (s
? RESTYPE_MIN
: RESTYPE_MAX
); /* ??? unspecified */
63 /* >= 2^23 is already an exact integer */
64 if (e
< SNG_FRACBITS
) {
65 /* add 0.5, extraction below will truncate */
66 x
+= (s
? -0.5 : 0.5);
69 GET_FLOAT_WORD(i0
, x
);
70 e
= ((i0
>> SNG_FRACBITS
) & 0xff) - SNG_EXP_BIAS
;
72 i0
|= (1 << SNG_FRACBITS
);
74 shift
= e
- SNG_FRACBITS
;
76 res
= (shift
< 32 ? (RESTYPE
)i0
<< shift
: 0);
78 res
= (shift
> -32 ? i0
>> -shift
: 0);
80 return (s
? -res
: res
);