1/*-
2 * Copyright (c) 2010 David Schultz <das@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * Tests for nearbyint{,f,l}()
29 *
30 * TODO:
31 * - adapt tests for rint(3)
32 * - tests for harder values (more mantissa bits than float)
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include <sys/param.h>
39#include <assert.h>
40#include <fenv.h>
41#include <math.h>
42#include <stdio.h>
43
44#include "test-utils.h"
45
46static int testnum;
47
48static const int rmodes[] = {
49	FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, FE_TOWARDZERO,
50};
51
52/* Make sure we're testing the library, not some broken compiler built-ins. */
53static double (*libnearbyint)(double) = nearbyint;
54static float (*libnearbyintf)(float) = nearbyintf;
55static long double (*libnearbyintl)(long double) = nearbyintl;
56#define nearbyintf libnearbyintf
57#define nearbyint libnearbyint
58#define nearbyintl libnearbyintl
59
60static const struct {
61	float in;
62	float out[3];	/* one answer per rounding mode except towardzero */
63} tests[] = {
64/* input	output (expected) */
65    { 0.0,	{ 0.0, 0.0, 0.0 }},
66    { 0.5,	{ 0.0, 0.0, 1.0 }},
67    { M_PI,	{ 3.0, 3.0, 4.0 }},
68    { 65536.5,	{ 65536, 65536, 65537 }},
69    { INFINITY,	{ INFINITY, INFINITY, INFINITY }},
70    { NAN,	{ NAN, NAN, NAN }},
71};
72
73/* Get the appropriate result for the current rounding mode. */
74static float
75get_output(int testindex, int rmodeindex, int negative)
76{
77	double out;
78
79	if (negative) {	/* swap downwards and upwards if input is negative */
80		if (rmodeindex == 1)
81			rmodeindex = 2;
82		else if (rmodeindex == 2)
83			rmodeindex = 1;
84	}
85	if (rmodeindex == 3) /* FE_TOWARDZERO uses the value for downwards */
86		rmodeindex = 1;
87	out = tests[testindex].out[rmodeindex];
88	return (negative ? -out : out);
89}
90
91static void
92test_nearby(int testindex)
93{
94	float in, out;
95	unsigned i;
96
97	for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
98		fesetround(rmodes[i]);
99		feclearexcept(ALL_STD_EXCEPT);
100
101		in = tests[testindex].in;
102		out = get_output(testindex, i, 0);
103		assert(fpequal(out, libnearbyintf(in)));
104		assert(fpequal(out, nearbyint(in)));
105		assert(fpequal(out, nearbyintl(in)));
106		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
107
108		in = -tests[testindex].in;
109		out = get_output(testindex, i, 1);
110		assert(fpequal(out, nearbyintf(in)));
111		assert(fpequal(out, nearbyint(in)));
112		assert(fpequal(out, nearbyintl(in)));
113		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
114	}
115
116	printf("ok %d\t\t# nearbyint(+%g)\n", testnum++, in);
117}
118
119static void
120test_modf(int testindex)
121{
122	float in, out;
123	float ipartf, ipart_expected;
124	double ipart;
125	long double ipartl;
126	unsigned i;
127
128	for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
129		fesetround(rmodes[i]);
130		feclearexcept(ALL_STD_EXCEPT);
131
132		in = tests[testindex].in;
133		ipart_expected = tests[testindex].out[1];
134		out = copysignf(
135		    isinf(ipart_expected) ? 0.0 : in - ipart_expected, in);
136		ipartl = ipart = ipartf = 42.0;
137
138		assert(fpequal(out, modff(in, &ipartf)));
139		assert(fpequal(ipart_expected, ipartf));
140		assert(fpequal(out, modf(in, &ipart)));
141		assert(fpequal(ipart_expected, ipart));
142		assert(fpequal(out, modfl(in, &ipartl)));
143		assert(fpequal(ipart_expected, ipartl));
144		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
145
146		in = -in;
147		ipart_expected = -ipart_expected;
148		out = -out;
149		ipartl = ipart = ipartf = 42.0;
150		assert(fpequal(out, modff(in, &ipartf)));
151		assert(fpequal(ipart_expected, ipartf));
152		assert(fpequal(out, modf(in, &ipart)));
153		assert(fpequal(ipart_expected, ipart));
154		assert(fpequal(out, modfl(in, &ipartl)));
155		assert(fpequal(ipart_expected, ipartl));
156		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
157	}
158
159	printf("ok %d\t\t# modf(+%g)\n", testnum++, in);
160}
161
162int
163main(void)
164{
165	unsigned i;
166
167	printf("1..%zu\n", (size_t)(nitems(tests) * 2));
168	testnum = 1;
169	for (i = 0; i < nitems(tests); i++) {
170		test_nearby(i);
171		test_modf(i);
172	}
173
174	return (0);
175}
176