1/*	$NetBSD: fixunsdfdi.c,v 1.8 2011/07/04 06:23:50 matt Exp $	*/
2/*-
3 * Copyright (c) 2011 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Matt Thomas of 3am Software Foundry.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
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 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32
33#if defined(LIBC_SCCS) && !defined(lint)
34__RCSID("$NetBSD: fixunsdfdi.c,v 1.8 2011/07/04 06:23:50 matt Exp $");
35#endif /* LIBC_SCCS and not lint */
36
37#include <stdbool.h>
38#include <stdint.h>
39#include <float.h>
40#include <machine/ieee.h>
41
42uint32_t __fixunsgen32(int, bool, size_t, size_t, const uint32_t *);
43
44uint32_t __fixunsdfsi(double);
45
46/*
47 * Convert double to (unsigned) int.  All operations are done module 2^32.
48 */
49uint32_t
50__fixunsdfsi(double x)
51{
52	const union ieee_double_u dblu = { .dblu_d = x };
53	const uint32_t frac[(DBL_FRACBITS + 31)/32 + 1] = {
54		[0] = 0,
55		[1] = dblu.dblu_dbl.dbl_fracl,
56		[2] = dblu.dblu_dbl.dbl_frach,
57	};
58
59	return __fixunsgen32(
60		dblu.dblu_dbl.dbl_exp - DBL_EXP_BIAS,
61		dblu.dblu_dbl.dbl_sign != 0,
62		DBL_MANT_DIG,
63		DBL_FRACHBITS,
64		&frac[__arraycount(frac)-1]);
65}
66