2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This software was developed by the Computer Systems Engineering group
6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7 * contributed to Berkeley.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 #if defined(LIBC_SCCS) && !defined(lint)
39 static char sccsid[] = "@(#)fixunsdfdi.c 8.1 (Berkeley) 6/4/93";
40 #endif /* LIBC_SCCS and not lint */
44 #define ONE_FOURTH (1 << (LONG_BITS - 2))
45 #define ONE_HALF (ONE_FOURTH * 2.0)
46 #define ONE (ONE_FOURTH * 4.0)
49 * Convert double to (unsigned) quad.
50 * Not sure what to do with negative numbers---for now, anything out
51 * of range becomes UQUAD_MAX.
61 return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */
62 #ifdef notdef /* this falls afoul of a GCC bug */
65 #else /* so we wire in 2^64-1 instead */
66 if (x >= 18446744073709551615.0)
70 * Get the upper part of the result. Note that the divide
71 * may round up; we want to avoid this if possible, so we
72 * subtract `1/2' first.
74 toppart = (x - ONE_HALF) / ONE;
76 * Now build a u_quad_t out of the top part. The difference
77 * between x and this is the bottom part (this may introduce
78 * a few fuzzy bits, but what the heck). With any luck this
79 * difference will be nonnegative: x should wind up in the
80 * range [0..ULONG_MAX]. For paranoia, we assume [LONG_MIN..
81 * 2*ULONG_MAX] instead.
83 t.ul[H] = (unsigned long)toppart;