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 /*
27 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30
31 #pragma weak modfl = __modfl
32
33 #include "libm.h"
34
35 #if defined(__sparc)
36 long double
37 __modfl(long double x, long double *iptr)
38 {
39 union {
40 unsigned i[4];
41 long double q;
42 } xx, yy;
43
44 unsigned hx, s;
45
46 xx.q = x;
47 hx = xx.i[0] & ~0x80000000;
48
49 if (hx >= 0x406f0000) { /* x is NaN, infinite, or integral */
50 *iptr = x;
51
52 if (hx < 0x7fff0000 || (hx == 0x7fff0000 && (xx.i[1] | xx.i[2] |
53 xx.i[3]) == 0)) {
54 xx.i[0] &= 0x80000000;
55 xx.i[1] = xx.i[2] = xx.i[3] = 0;
56 }
57
58 return (xx.q);
59 }
60
61 if (hx < 0x3fff0000) { /* |x| < 1 */
62 xx.i[0] &= 0x80000000;
63 xx.i[1] = xx.i[2] = xx.i[3] = 0;
64 *iptr = xx.q;
65 return (x);
66 }
67
68 /* split x at the binary point */
69 s = xx.i[0] & 0x80000000;
70
71 if (hx < 0x40100000) {
72 yy.i[0] = xx.i[0] & ~((1 << (0x400f - (hx >> 16))) - 1);
73 yy.i[1] = yy.i[2] = yy.i[3] = 0;
74 } else if (hx < 0x40300000) {
75 yy.i[0] = xx.i[0];
76 yy.i[1] = xx.i[1] & ~((1 << (0x402f - (hx >> 16))) - 1);
77 yy.i[2] = yy.i[3] = 0;
78 } else if (hx < 0x40500000) {
79 yy.i[0] = xx.i[0];
80 yy.i[1] = xx.i[1];
81 yy.i[2] = xx.i[2] & ~((1 << (0x404f - (hx >> 16))) - 1);
82 yy.i[3] = 0;
83 } else {
84 yy.i[0] = xx.i[0];
85 yy.i[1] = xx.i[1];
86 yy.i[2] = xx.i[2];
87 yy.i[3] = xx.i[3] & ~((1 << (0x406f - (hx >> 16))) - 1);
88 }
89
90 *iptr = yy.q;
91
92 /*
93 * we could implement the following more efficiently than by using
94 * software emulation of fsubq, but we'll do it this way for now
95 * (and hope hardware support becomes commonplace)
96 */
97 xx.q -= yy.q;
98 xx.i[0] = (xx.i[0] & ~0x80000000) | s; /* keep sign of x */
99 return (xx.q);
100 }
101 #elif defined(__x86)
102 long double
103 __modfl(long double x, long double *iptr)
104 {
105 union {
106 unsigned i[3];
107 long double e;
108 } xx, yy;
109
110 unsigned hx, s;
111
112 /*
113 * It might be faster to use one of the x86 fpops instead of
114 * the following.
115 */
116 xx.e = x;
117 hx = xx.i[2] & 0x7fff;
118
119 if (hx >= 0x403e) { /* x is NaN, infinite, or integral */
120 *iptr = x;
121
122 if (hx < 0x7fff || (hx == 0x7fff && ((xx.i[1] << 1) |
123 xx.i[0]) == 0)) {
124 xx.i[2] &= 0x8000;
125 xx.i[1] = xx.i[0] = 0;
126 }
127
128 return (xx.e);
129 }
130
131 if (hx < 0x3fff) { /* |x| < 1 */
132 xx.i[2] &= 0x8000;
133 xx.i[1] = xx.i[0] = 0;
134 *iptr = xx.e;
135 return (x);
136 }
137
138 /* split x at the binary point */
139 s = xx.i[2] & 0x8000;
140 yy.i[2] = xx.i[2];
141
142 if (hx < 0x401f) {
143 yy.i[1] = xx.i[1] & ~((1 << (0x401e - hx)) - 1);
144 yy.i[0] = 0;
145 } else {
146 yy.i[1] = xx.i[1];
147 yy.i[0] = xx.i[0] & ~((1 << (0x403e - hx)) - 1);
148 }
149
150 *iptr = yy.e;
151 xx.e -= yy.e;
152 xx.i[2] = (xx.i[2] & ~0x8000) | s; /* keep sign of x */
153 return (xx.e);
154 }
155 #else
156 #error Unknown architecture
157 #endif