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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 1994-1997, by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include "quad.h"
30
31 /*
32 * _Qp_xtoq(pz, x) sets *pz = (long double)x.
33 */
34 void
_Qp_xtoq(union longdouble * pz,long x)35 _Qp_xtoq(union longdouble *pz, long x)
36 {
37 unsigned int s, e;
38
39 /* extract the sign */
40 s = 0;
41 if (x < 0) {
42 if ((unsigned long) x == 0x8000000000000000ul) {
43 /* largest negative 64 bit int */
44 Z.l.msw = 0xc03e0000;
45 Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
46 QUAD_RETURN(Z);
47 }
48 x = -x;
49 s = 0x80000000;
50 } else if (x == 0) {
51 Z.l.msw = Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
52 QUAD_RETURN(Z);
53 }
54
55 /* find the most significant bit */
56 for (e = 62; (x & (1l << e)) == 0; e--)
57 ;
58
59 if (e > 48) {
60 Z.l.msw = ((unsigned long) x >> (e - 16)) & 0xffff;
61 Z.l.frac2 = (unsigned long) x >> (e - 48);
62 Z.l.frac3 = (unsigned long) x << (80 - e);
63 } else if (e > 16) {
64 Z.l.msw = ((unsigned long) x >> (e - 16)) & 0xffff;
65 Z.l.frac2 = (unsigned long) x << (48 - e);
66 Z.l.frac3 = 0;
67 } else {
68 Z.l.msw = ((unsigned long) x << (16 - e)) & 0xffff;
69 Z.l.frac2 = Z.l.frac3 = 0;
70 }
71 Z.l.frac4 = 0;
72 Z.l.msw |= s | ((e + 0x3fff) << 16);
73 QUAD_RETURN(Z);
74 }
75