1 /* $OpenBSD: fixdfdi.c,v 1.1 2022/09/03 08:26:05 mbuhl Exp $ */
2 /* $NetBSD: fixdfdi_ieee754.c,v 1.1 2013/08/24 00:51:48 matt Exp $ */
3
4 /*-
5 * Copyright (c) 1992, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This software was developed by the Computer Systems Engineering group
9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10 * contributed to Berkeley.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38 #if defined(LIBC_SCCS) && !defined(lint)
39 __RCSID("$NetBSD: fixdfdi_ieee754.c,v 1.1 2013/08/24 00:51:48 matt Exp $");
40 #endif /* LIBC_SCCS and not lint */
41
42 #if defined(SOFTFLOAT) || defined(__ARM_EABI__)
43 #include "softfloat/softfloat-for-gcc.h"
44 #endif
45
46 #include "../../../quad/quad.h"
47 #include <limits.h>
48 #include <stdbool.h>
49 #include <machine/ieee.h>
50
51 /*
52 * Convert double to signed quad.
53 * Not sure what to do with negative numbers---for now, anything out
54 * of range becomes UQUAD_MAX.
55 */
56 quad_t
__fixdfdi(double x)57 __fixdfdi(double x)
58 {
59 struct ieee_double ux = *(struct ieee_double *)&x;
60 signed int exp = ux.dbl_exp - DBL_EXP_BIAS;
61 const bool neg = ux.dbl_sign;
62 quad_t r;
63
64 if (exp > 62)
65 return neg ? QUAD_MIN : QUAD_MAX;
66
67 r = 1 << DBL_FRACHBITS; /* implicit bit */
68 r |= ux.dbl_frach;
69 exp -= DBL_FRACHBITS;
70 if (exp < 0) {
71 r >>= -exp;
72 } else if (exp > 0) {
73 r <<= DBL_FRACLBITS;
74 r |= ux.dbl_fracl;
75 exp -= DBL_FRACLBITS;
76 if (exp < 0) {
77 r >>= -exp;
78 } else if (exp > 0) {
79 r <<= exp;
80 }
81 }
82 return neg ? -r : r;
83 }
84