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 __lrintf = lrintf
31
32 #include <sys/isa_defs.h> /* _ILP32 */
33 #include "libm.h"
34
35 #if defined(_ILP32)
36 long
lrintf(float x)37 lrintf(float x) {
38 /*
39 * Note: The following code works on x86 (in the default rounding
40 * precision mode), but one should just use the fistpl instruction
41 * instead.
42 */
43 union {
44 unsigned i;
45 float f;
46 } xx, yy;
47 unsigned hx;
48
49 xx.f = x;
50 hx = xx.i & ~0x80000000;
51 if (hx < 0x4b000000) { /* |x| < 2^23 */
52 /* add and subtract a power of two to round x to an integer */
53 #if defined(__sparc)
54 yy.i = (xx.i & 0x80000000) | 0x4b000000;
55 #elif defined(__x86)
56 /* assume 64-bit precision */
57 yy.i = (xx.i & 0x80000000) | 0x5f000000;
58 #else
59 #error Unknown architecture
60 #endif
61 x = (x + yy.f) - yy.f;
62 return ((long) x);
63 }
64
65 /* now x is nan, inf, or integral */
66 return ((long) x);
67 }
68 #else
69 #error Unsupported architecture
70 #endif /* defined(_ILP32) */
71