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 __round = round
31
32 #include "libm.h"
33
34 double
35 round(double x) {
36 union {
37 unsigned i[2];
38 double d;
39 } xx;
40 unsigned hx, sx, i;
41
42 xx.d = x;
43 hx = xx.i[HIWORD] & ~0x80000000;
44 sx = xx.i[HIWORD] & 0x80000000;
45 if (hx < 0x43300000) { /* |x| < 2^52 */
46 if (hx < 0x3ff00000) { /* |x| < 1 */
47 if (hx >= 0x3fe00000)
48 return (sx ? -1.0 : 1.0);
49 return (sx ? -0.0 : 0.0);
50 }
51
52 /* round x at the integer bit */
53 if (hx < 0x41300000) {
54 i = 1 << (0x412 - (hx >> 20));
55 xx.i[HIWORD] = (xx.i[HIWORD] + i) & ~(i | (i - 1));
56 xx.i[LOWORD] = 0;
57 } else {
58 i = 1 << (0x432 - (hx >> 20));
59 xx.i[LOWORD] += i;
60 if (xx.i[LOWORD] < i)
61 xx.i[HIWORD]++;
62 xx.i[LOWORD] &= ~(i | (i - 1));
63 }
64 return (xx.d);
65 } else if (hx < 0x7ff00000)
66 return (x);
67 else
68 #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
69 return (hx >= 0x7ff80000 ? x : x + x);
70 /* assumes sparc-like QNaN */
71 #else
72 return (x + x);
73 #endif
74 }
|
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 /*
27 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30
31 #pragma weak __round = round
32
33 #include "libm.h"
34
35 double
36 round(double x)
37 {
38 union {
39 unsigned i[2];
40 double d;
41 } xx;
42
43 unsigned hx, sx, i;
44
45 xx.d = x;
46 hx = xx.i[HIWORD] & ~0x80000000;
47 sx = xx.i[HIWORD] & 0x80000000;
48
49 if (hx < 0x43300000) { /* |x| < 2^52 */
50 if (hx < 0x3ff00000) { /* |x| < 1 */
51 if (hx >= 0x3fe00000)
52 return (sx ? -1.0 : 1.0);
53
54 return (sx ? -0.0 : 0.0);
55 }
56
57 /* round x at the integer bit */
58 if (hx < 0x41300000) {
59 i = 1 << (0x412 - (hx >> 20));
60 xx.i[HIWORD] = (xx.i[HIWORD] + i) & ~(i | (i - 1));
61 xx.i[LOWORD] = 0;
62 } else {
63 i = 1 << (0x432 - (hx >> 20));
64 xx.i[LOWORD] += i;
65
66 if (xx.i[LOWORD] < i)
67 xx.i[HIWORD]++;
68
69 xx.i[LOWORD] &= ~(i | (i - 1));
70 }
71
72 return (xx.d);
73 } else if (hx < 0x7ff00000) {
74 return (x);
75 } else {
76 #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
77 return (hx >= 0x7ff80000 ? x : x + x);
78
79 /* assumes sparc-like QNaN */
80 #else
81 return (x + x);
82 #endif
83 }
84 }
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