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 __truncl = truncl
31
32 #include "libm.h"
33
34 #if defined(__sparc)
35 long double
truncl(long double x)36 truncl(long double x) {
37 union {
38 unsigned i[4];
39 long double q;
40 } xx;
41 unsigned hx, sx;
42 int j;
43
44 xx.q = x;
45 sx = xx.i[0] & 0x80000000;
46 hx = xx.i[0] & ~0x80000000;
47
48 /* handle trivial cases */
49 if (hx >= 0x406f0000) /* |x| >= 2^112 + ... or x is nan */
50 return (hx >= 0x7fff0000 ? x + x : x);
51
52 /* handle |x| < 1 */
53 if (hx < 0x3fff0000)
54 return (sx ? -0.0L : 0.0L);
55
56 j = 0x406f - (hx >> 16); /* 1 <= j <= 112 */
57 xx.i[0] = hx;
58 if (j >= 96) { /* 96 <= j <= 112 */
59 xx.i[0] &= ~((1 << (j - 96)) - 1);
60 xx.i[1] = xx.i[2] = xx.i[3] = 0;
61 } else if (j >= 64) { /* 64 <= j <= 95 */
62 xx.i[1] &= ~((1 << (j - 64)) - 1);
63 xx.i[2] = xx.i[3] = 0;
64 } else if (j >= 32) { /* 32 <= j <= 63 */
65 xx.i[2] &= ~((1 << (j - 32)) - 1);
66 xx.i[3] = 0;
67 } else /* 1 <= j <= 31 */
68 xx.i[3] &= ~((1 << j) - 1);
69
70 /* negate result if need be */
71 if (sx)
72 xx.i[0] |= 0x80000000;
73 return (xx.q);
74 }
75 #elif defined(__x86)
76 long double
truncl(long double x)77 truncl(long double x) {
78 union {
79 unsigned i[3];
80 long double e;
81 } xx;
82 int ex, sx, i;
83
84 xx.e = x;
85 ex = xx.i[2] & 0x7fff;
86 sx = xx.i[2] & 0x8000;
87 if (ex < 0x403e) { /* |x| < 2^63 */
88 if (ex < 0x3fff) /* |x| < 1 */
89 return (sx ? -0.0L : 0.0L);
90
91 /* chop x at the integer bit */
92 if (ex < 0x401e) {
93 i = 1 << (0x401d - ex);
94 xx.i[1] &= ~(i | (i - 1));
95 xx.i[0] = 0;
96 } else {
97 i = 1 << (0x403d - ex);
98 xx.i[0] &= ~(i | (i - 1));
99 }
100 return (xx.e);
101 } else if (ex < 0x7fff) /* x is integral */
102 return (x);
103 else /* inf or nan */
104 return (x + x);
105 }
106 #else
107 #error Unknown architecture
108 #endif /* defined(__sparc) || defined(__x86) */
109