xref: /illumos-gate/usr/src/lib/libc/sparc/fp/_Q_utoq.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 #ifdef __sparcv9
30 
31 /*
32  * _Qp_uitoq(pz, x) sets *pz = (long double)x.
33  */
34 void
35 _Qp_uitoq(union longdouble *pz, unsigned int x)
36 
37 #else
38 
39 /*
40  * _Q_utoq(x) returns (long double)x.
41  */
42 union longdouble
43 _Q_utoq(unsigned int x)
44 
45 #endif /* __sparcv9 */
46 
47 {
48 #ifndef __sparcv9
49 	union longdouble	z;
50 #endif
51 	unsigned int		e;
52 
53 	/* test for zero */
54 	if (x == 0) {
55 		Z.l.msw = Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
56 		QUAD_RETURN(Z);
57 	}
58 
59 	/* find the most significant bit */
60 	for (e = 31; (x & (1 << e)) == 0; e--)
61 		;
62 
63 	if (e > 16) {
64 		Z.l.msw = ((unsigned) x >> (e - 16)) & 0xffff;
65 		Z.l.frac2 = (unsigned) x << (48 - e);
66 	} else {
67 		Z.l.msw = ((unsigned) x << (16 - e)) & 0xffff;
68 		Z.l.frac2 = 0;
69 	}
70 	Z.l.frac3 = Z.l.frac4 = 0;
71 	Z.l.msw |= ((e + 0x3fff) << 16);
72 	QUAD_RETURN(Z);
73 }
74