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 #include "quad.h"
28
29 /*
30 * _Qp_xtoq(pz, x) sets *pz = (long double)x.
31 */
32 void
_Qp_xtoq(union longdouble * pz,long x)33 _Qp_xtoq(union longdouble *pz, long x)
34 {
35 unsigned int s, e;
36
37 /* extract the sign */
38 s = 0;
39 if (x < 0) {
40 if ((unsigned long) x == 0x8000000000000000ul) {
41 /* largest negative 64 bit int */
42 Z.l.msw = 0xc03e0000;
43 Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
44 QUAD_RETURN(Z);
45 }
46 x = -x;
47 s = 0x80000000;
48 } else if (x == 0) {
49 Z.l.msw = Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
50 QUAD_RETURN(Z);
51 }
52
53 /* find the most significant bit */
54 for (e = 62; (x & (1l << e)) == 0; e--)
55 ;
56
57 if (e > 48) {
58 Z.l.msw = ((unsigned long) x >> (e - 16)) & 0xffff;
59 Z.l.frac2 = (unsigned long) x >> (e - 48);
60 Z.l.frac3 = (unsigned long) x << (80 - e);
61 } else if (e > 16) {
62 Z.l.msw = ((unsigned long) x >> (e - 16)) & 0xffff;
63 Z.l.frac2 = (unsigned long) x << (48 - e);
64 Z.l.frac3 = 0;
65 } else {
66 Z.l.msw = ((unsigned long) x << (16 - e)) & 0xffff;
67 Z.l.frac2 = Z.l.frac3 = 0;
68 }
69 Z.l.frac4 = 0;
70 Z.l.msw |= s | ((e + 0x3fff) << 16);
71 QUAD_RETURN(Z);
72 }
73