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 roundl = __roundl
31
32 #include "libm.h"
33
34 #if defined(__sparc)
35 long double
36 roundl(long double x) {
37 union {
38 unsigned i[4];
39 long double q;
40 } xx;
41 unsigned hx, sx, v;
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 if (hx >= 0x3ffe0000)
55 return (sx ? -1.0L : 1.0L);
56 return (sx ? -0.0L : 0.0L);
57 }
58
59 xx.i[0] = hx;
60 j = 0x406f - (hx >> 16); /* 1 <= j <= 112 */
61 if (j >= 96) { /* 96 <= j <= 112 */
62 v = (1U << (j - 96)) >> 1;
63 if (v) {
64 if (xx.i[0] & v)
65 xx.i[0] += v;
66 xx.i[0] &= ~(v - 1);
67 } else if (xx.i[1] & 0x80000000)
68 ++xx.i[0];
69 xx.i[1] = xx.i[2] = xx.i[3] = 0;
70 } else if (j >= 64) { /* 64 <= j <= 95 */
71 v = (1U << (j - 64)) >> 1;
72 if (v) {
73 if (xx.i[1] & v) {
74 xx.i[1] += v;
75 if (xx.i[1] < v)
76 ++xx.i[0];
77 }
78 xx.i[1] &= ~(v - 1);
79 } else if (xx.i[2] & 0x80000000) {
80 if (++xx.i[1] == 0)
81 ++xx.i[0];
82 }
83 xx.i[2] = xx.i[3] = 0;
84 } else if (j >= 32) { /* 32 <= j <= 63 */
85 v = (1U << (j - 32)) >> 1;
86 if (v) {
87 if (xx.i[2] & v) {
88 xx.i[2] += v;
89 if (xx.i[2] < v) {
90 if (++xx.i[1] == 0)
91 ++xx.i[0];
92 }
93 }
94 xx.i[2] &= ~(v - 1);
95 } else if (xx.i[3] & 0x80000000) {
96 if (++xx.i[2] == 0) {
97 if (++xx.i[1] == 0)
98 ++xx.i[0];
99 }
100 }
101 xx.i[3] = 0;
102 } else { /* 1 <= j <= 31 */
103 v = 1U << (j - 1);
104 if (xx.i[3] & v) {
105 xx.i[3] += v;
106 if (xx.i[3] < v) {
107 if (++xx.i[2] == 0) {
108 if (++xx.i[1] == 0)
109 ++xx.i[0];
110 }
111 }
112 }
113 xx.i[3] &= ~(v - 1);
114 }
115
116 /* negate result if need be */
117 if (sx)
118 xx.i[0] |= 0x80000000;
119 return (xx.q);
120 }
121 #elif defined(__x86)
122 long double
123 roundl(long double x) {
124 union {
125 unsigned i[3];
126 long double e;
127 } xx;
128 int ex, sx, i;
129
130 xx.e = x;
131 ex = xx.i[2] & 0x7fff;
132 sx = xx.i[2] & 0x8000;
133 if (ex < 0x403e) { /* |x| < 2^63 */
134 if (ex < 0x3fff) { /* |x| < 1 */
135 if (ex >= 0x3ffe)
136 return (sx ? -1.0L : 1.0L);
137 return (sx ? -0.0L : 0.0L);
138 }
139
140 /* round x at the integer bit */
141 if (ex < 0x401e) {
142 i = 1 << (0x401d - ex);
143 xx.i[1] = (xx.i[1] + i) & ~(i | (i - 1));
144 xx.i[0] = 0;
145 } else {
146 i = 1 << (0x403d - ex);
147 xx.i[0] += i;
148 if (xx.i[0] < i)
149 xx.i[1]++;
150 xx.i[0] &= ~(i | (i - 1));
151 }
152 if (xx.i[1] == 0) {
153 xx.i[2] = sx | ++ex;
154 xx.i[1] = 0x80000000U;
155 }
156 return (xx.e);
157 } else if (ex < 0x7fff) /* x is integral */
158 return (x);
159 else /* inf or nan */
160 return (x + x);
161 }
162 #else
163 #error Unknown architecture
164 #endif /* defined(__sparc) || defined(__x86) */