1 /* $OpenBSD: fixunsdfdi.c,v 1.9 2019/11/10 22:23:28 guenther Exp $ */
2 /*-
3 * Copyright (c) 1992, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This software was developed by the Computer Systems Engineering group
7 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
8 * contributed to Berkeley.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include "quad.h"
36
37 #define ONE_FOURTH ((int)1 << (INT_BITS - 2))
38 #define ONE_HALF (ONE_FOURTH * 2.0)
39 #define ONE (ONE_FOURTH * 4.0)
40
41 /*
42 * Convert double to (unsigned) quad.
43 * Not sure what to do with negative numbers---for now, anything out
44 * of range becomes UQUAD_MAX.
45 */
46 u_quad_t
__fixunsdfdi(double x)47 __fixunsdfdi(double x)
48 {
49 union uu t;
50 unsigned int tmp;
51
52 if (x < 0)
53 return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */
54 #ifdef notdef /* this falls afoul of a GCC bug */
55 if (x >= UQUAD_MAX)
56 return (UQUAD_MAX);
57 #else /* so we wire in 2^64-1 instead */
58 if (x >= 18446744073709551615.0) /* XXX */
59 return (UQUAD_MAX);
60 #endif
61 /*
62 * Now we know that 0 <= x <= 18446744073709549568. The upper
63 * limit is one ulp less than 18446744073709551615 tested for above.
64 * Dividing this by 2^32 will *not* round irrespective of any
65 * rounding modes (except if the result is an IEEE denorm).
66 * Furthermore, the quotient will fit into a 32-bit integer.
67 */
68 tmp = x / ONE;
69 t.ul[L] = (unsigned int) (x - tmp * ONE);
70 t.ul[H] = tmp;
71 return (t.uq);
72 }
73
74 #ifdef __ARM_EABI__
75 __strong_alias(__aeabi_d2ulz, __fixunsdfdi);
76 __asm(".protected __aeabi_d2ulz");
77 #endif
78