xref: /titanic_50/usr/src/lib/libc/sparcv9/fp/__dtoul.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1*7c478bd9Sstevel@tonic-gate /*
2*7c478bd9Sstevel@tonic-gate  * CDDL HEADER START
3*7c478bd9Sstevel@tonic-gate  *
4*7c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*7c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*7c478bd9Sstevel@tonic-gate  * with the License.
8*7c478bd9Sstevel@tonic-gate  *
9*7c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*7c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*7c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*7c478bd9Sstevel@tonic-gate  * and limitations under the License.
13*7c478bd9Sstevel@tonic-gate  *
14*7c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*7c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*7c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*7c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*7c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*7c478bd9Sstevel@tonic-gate  *
20*7c478bd9Sstevel@tonic-gate  * CDDL HEADER END
21*7c478bd9Sstevel@tonic-gate  */
22*7c478bd9Sstevel@tonic-gate /*
23*7c478bd9Sstevel@tonic-gate  * Copyright (c) 1994-1997, by Sun Microsystems, Inc.
24*7c478bd9Sstevel@tonic-gate  * All rights reserved.
25*7c478bd9Sstevel@tonic-gate  */
26*7c478bd9Sstevel@tonic-gate 
27*7c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*7c478bd9Sstevel@tonic-gate 
29*7c478bd9Sstevel@tonic-gate /*
30*7c478bd9Sstevel@tonic-gate  * __dtoul(x) converts double x to unsigned long.
31*7c478bd9Sstevel@tonic-gate  */
32*7c478bd9Sstevel@tonic-gate unsigned long
__dtoul(double x)33*7c478bd9Sstevel@tonic-gate __dtoul(double x)
34*7c478bd9Sstevel@tonic-gate {
35*7c478bd9Sstevel@tonic-gate 	union {
36*7c478bd9Sstevel@tonic-gate 		double		d;
37*7c478bd9Sstevel@tonic-gate 		unsigned long	l;
38*7c478bd9Sstevel@tonic-gate 	} u;
39*7c478bd9Sstevel@tonic-gate 
40*7c478bd9Sstevel@tonic-gate 	u.d = x;
41*7c478bd9Sstevel@tonic-gate 
42*7c478bd9Sstevel@tonic-gate 	/* handle cases for which double->unsigned long differs from */
43*7c478bd9Sstevel@tonic-gate 	/* double->signed long */
44*7c478bd9Sstevel@tonic-gate 	if ((u.l >> 52) == 0x43e) {
45*7c478bd9Sstevel@tonic-gate 		/* 2^63 <= x < 2^64 */
46*7c478bd9Sstevel@tonic-gate 		return (0x8000000000000000ul | (u.l << 11));
47*7c478bd9Sstevel@tonic-gate 	}
48*7c478bd9Sstevel@tonic-gate 
49*7c478bd9Sstevel@tonic-gate 	/* for all other cases, just convert to signed long */
50*7c478bd9Sstevel@tonic-gate 	return ((long)x);
51*7c478bd9Sstevel@tonic-gate }
52