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: lrintf.c,v 1.3 2004/10/13 15:18:32 drochner Exp $
27 * $DragonFly: src/lib/libm/src/lrintf.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 LRINTNAME lrintf
37 #define RESTYPE long int
38 #define RESTYPE_MIN LONG_MIN
39 #define RESTYPE_MAX LONG_MAX
42 #define RESTYPE_BITS (sizeof(RESTYPE) * 8)
46 8.3886080000e+06, /* 0x4b000000 */
47 -8.3886080000e+06, /* 0xcb000000 */
57 GET_FLOAT_WORD(i0, x);
58 e = i0 >> SNG_FRACBITS;
60 e = (e & 0xff) - SNG_EXP_BIAS;
62 /* 1.0 x 2^-1 is the smallest number which can be rounded to 1 */
65 /* 1.0 x 2^31 (or 2^63) is already too large */
66 if (e >= (int)RESTYPE_BITS - 1)
67 return (s ? RESTYPE_MIN : RESTYPE_MAX); /* ??? unspecified */
69 /* >= 2^23 is already an exact integer */
70 if (e < SNG_FRACBITS) {
71 /* round, using current direction */
76 GET_FLOAT_WORD(i0, x);
77 e = ((i0 >> SNG_FRACBITS) & 0xff) - SNG_EXP_BIAS;
79 i0 |= (1 << SNG_FRACBITS);
81 shift = e - SNG_FRACBITS;
83 res = (shift < 32 ? (RESTYPE)i0 << shift : 0);
85 res = (shift > -32 ? i0 >> -shift : 0);
87 return (s ? -res : res);