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 __llrintf = llrintf
31 #if defined(__sparcv9) || defined(__amd64)
32 #pragma weak lrintf = llrintf
33 #pragma weak __lrintf = llrintf
34 #endif
35
36 #include "libm.h"
37
38 long long
llrintf(float x)39 llrintf(float x) {
40 /*
41 * Note: The following code works on x86 (in the default rounding
42 * precision mode), but one should just use the fistpll instruction
43 * instead.
44 */
45 union {
46 unsigned i;
47 float f;
48 } xx, yy;
49 unsigned hx;
50
51 xx.f = x;
52 hx = xx.i & ~0x80000000;
53
54 if (hx < 0x4b000000) { /* |x| < 2^23 */
55 /* add and subtract a power of two to round x to an integer */
56 #if defined(__sparc) || defined(__amd64)
57 yy.i = (xx.i & 0x80000000) | 0x4b000000;
58 #elif defined(__i386)
59 /* assume 64-bit precision */
60 yy.i = (xx.i & 0x80000000) | 0x5f000000;
61 #else
62 #error Unknown architecture
63 #endif
64 x = (x + yy.f) - yy.f;
65
66 /*
67 * on LP32 architectures, we can just convert x to a 32-bit
68 * integer and sign-extend it
69 */
70 return ((long) x);
71 }
72
73 /* now x is nan, inf, or integral */
74 return ((long long) x);
75 }
76