1 /* $NetBSD: fixunsdfdi_ieee754.c,v 1.1 2013/08/24 00:51:48 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_ieee754.c,v 1.1 2013/08/24 00:51:48 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 <machine/ieee.h>
48
49 /*
50 * Convert double to unsigned quad.
51 * Not sure what to do with negative numbers---for now, anything out
52 * of range becomes UQUAD_MAX.
53 */
54 u_quad_t
__fixunsdfdi(double x)55 __fixunsdfdi(double x)
56 {
57 const union ieee_double_u ux = { .dblu_d = x };
58 signed int exp = ux.dblu_exp - DBL_EXP_BIAS;
59 u_quad_t r;
60
61 if (ux.dblu_sign)
62 return UQUAD_MAX;
63 if (exp > 63)
64 return UQUAD_MAX;
65 if (exp < 0)
66 return 0;
67
68 r = 1 << DBL_FRACHBITS; /* implicit bit */
69 r |= ux.dblu_frach;
70 exp -= DBL_FRACHBITS;
71 if (exp == 0)
72 return r;
73 if (exp < 0)
74 return r >> -exp;
75
76 r <<= DBL_FRACLBITS;
77 r |= ux.dblu_fracl;
78 exp -= DBL_FRACLBITS;
79 if (exp == 0)
80 return r;
81 if (exp < 0)
82 return r >> -exp;
83
84 return r << exp;
85 }
86