1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 */
25 /*
26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
27 * Use is subject to license terms.
28 */
29
30 #pragma weak __truncf = truncf
31
32 #include "libm.h"
33
34 float
truncf(float x)35 truncf(float x) {
36 union {
37 unsigned i;
38 float f;
39 } xx;
40 unsigned hx, sx, i;
41
42 xx.f = x;
43 hx = xx.i & ~0x80000000;
44 sx = xx.i & 0x80000000;
45 if (hx < 0x4b000000) { /* |x| < 2^23 */
46 if (hx < 0x3f800000) /* |x| < 1 */
47 return (sx ? -0.0F : 0.0F);
48
49 /* chop x at the integer bit */
50 i = 1 << (0x95 - (hx >> 23));
51 xx.i &= ~((i << 1) - 1);
52 return (xx.f);
53 } else if (hx < 0x7f800000) /* |x| is integral */
54 return (x);
55 else
56 #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
57 return (hx > 0x7f800000 ? x * x : x + x);
58 #else
59 return (x + x);
60 #endif
61 }
62