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__RCSID("$NetBSD: fixunsdfdi.c,v 1.11 2013/02/03 01:48:53 matt Exp $");
39#endif /* LIBC_SCCS and not lint */
40
41#if defined(SOFTFLOAT) || defined(__ARM_EABI__)
42#include "softfloat/softfloat-for-gcc.h"
43#endif
44
45#include "quad.h"
46#include <limits.h>
47#include <stdbool.h>
48#include <machine/ieee.h>
49
50/*
51 * Convert double to signed quad.
52 * Not sure what to do with negative numbers---for now, anything out
53 * of range becomes UQUAD_MAX.
54 */
55quad_t
56__fixdfdi(double x)
57{
58	const union ieee_double_u ux = { .dblu_d = x };
59	signed int exp = ux.dblu_exp - DBL_EXP_BIAS;
60	const bool neg = ux.dblu_sign;
61	quad_t r;
62
63	if (exp >= 62)
64		return neg ? QUAD_MIN : QUAD_MAX;
65
66	r = 1 << DBL_FRACHBITS;		/* implicit bit */
67	r |= ux.dblu_frach;
68	exp -= DBL_FRACHBITS;
69	if (exp < 0) {
70		r >>= -exp;
71	} else if (exp > 0) {
72		r <<= DBL_FRACLBITS;
73		r |= ux.dblu_fracl;
74		exp -= DBL_FRACLBITS;
75		if (exp < 0) {
76			r >>= -exp;
77		} else if (exp > 0) {
78			r <<= exp;
79		}
80	}
81	return neg ? -r : r;
82}
83