1/* $NetBSD: t_round.c,v 1.4 2013/11/11 23:57:34 joerg Exp $ */
2
3/*-
4 * Copyright (c) 2011 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <atf-c.h>
30#include <float.h>
31#include <math.h>
32
33/*
34 * This tests for a bug in the initial implementation where
35 * precision was lost in an internal substraction, leading to
36 * rounding into the wrong direction.
37 */
38
39/* 0.5 - EPSILON */
40#define VAL	0x0.7ffffffffffffcp0
41#define VALF	0x0.7fffff8p0
42#define VALL	(0.5 - LDBL_EPSILON)
43
44#ifdef __vax__
45#define SMALL_NUM	1.0e-38
46#else
47#define SMALL_NUM	1.0e-40
48#endif
49
50ATF_TC(round_dir);
51ATF_TC_HEAD(round_dir, tc)
52{
53	atf_tc_set_md_var(tc, "descr","Check for rounding in wrong direction");
54}
55
56ATF_TC_BODY(round_dir, tc)
57{
58	double a = VAL, b, c;
59	float af = VALF, bf, cf;
60	long double al = VALL, bl, cl;
61
62	b = round(a);
63	bf = roundf(af);
64	bl = roundl(al);
65
66	ATF_CHECK(fabs(b) < SMALL_NUM);
67	ATF_CHECK(fabsf(bf) < SMALL_NUM);
68	ATF_CHECK(fabsl(bl) < SMALL_NUM);
69
70	c = round(-a);
71	cf = roundf(-af);
72	cl = roundl(-al);
73
74	ATF_CHECK(fabs(c) < SMALL_NUM);
75	ATF_CHECK(fabsf(cf) < SMALL_NUM);
76	ATF_CHECK(fabsl(cl) < SMALL_NUM);
77}
78
79ATF_TP_ADD_TCS(tp)
80{
81
82	ATF_TP_ADD_TC(tp, round_dir);
83
84	return atf_no_error();
85}
86