1 /* $NetBSD: fixunsdfdi.c,v 1.11 2013/02/03 01:48:53 matt Exp $ */
2
3 /*-
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)fixunsdfdi.c 8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: fixunsdfdi.c,v 1.11 2013/02/03 01:48:53 matt Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44
45 #if defined(SOFTFLOAT) || defined(__ARM_EABI__)
46 #include "softfloat/softfloat-for-gcc.h"
47 #endif
48
49 #include "quad.h"
50
51 #define ONE_FOURTH ((int)1 << (unsigned int)(INT_BITS - 2))
52 #define ONE_HALF (ONE_FOURTH * 2.0)
53 #define ONE (ONE_FOURTH * 4.0)
54
55 /*
56 * Convert double to (unsigned) quad.
57 * Not sure what to do with negative numbers---for now, anything out
58 * of range becomes UQUAD_MAX.
59 */
60 u_quad_t
__fixunsdfdi(double x)61 __fixunsdfdi(double x)
62 {
63 union uu t;
64 unsigned int tmp;
65
66 if (x < 0)
67 return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */
68 #ifdef notdef /* this falls afoul of a GCC bug */
69 if (x >= UQUAD_MAX)
70 return (UQUAD_MAX);
71 #else /* so we wire in 2^64-1 instead */
72 if (x >= 18446744073709551615.0) /* XXX */
73 return (UQUAD_MAX);
74 #endif
75 /*
76 * Now we know that 0 <= x <= 18446744073709549568. The upper
77 * limit is one ulp less than 18446744073709551615 tested for above.
78 * Dividing this by 2^32 will *not* round irrespective of any
79 * rounding modes (except if the result is an IEEE denorm).
80 * Furthermore, the quotient will fit into a 32-bit integer.
81 */
82 tmp = x / ONE;
83 t.ul[L] = (unsigned int) (x - tmp * ONE);
84 t.ul[H] = tmp;
85 return (t.uq);
86 }
87