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