1/*-
2 * Copyright (c) 2005-2008 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 * Test for remainder functions: remainder, remainderf, remainderl,
29 * remquo, remquof, and remquol.
30 * Missing tests: fmod, fmodf.
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#include <assert.h>
37#include <float.h>
38#include <math.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <strings.h>
42
43static void test_invalid(long double, long double);
44static void testl(long double, long double, long double, int);
45static void testd(double, double, double, int);
46static void testf(float, float, float, int);
47
48#define	test(x, y, e_r, e_q) do {	\
49	testl(x, y, e_r, e_q);		\
50	testd(x, y, e_r, e_q);		\
51	testf(x, y, e_r, e_q);		\
52} while (0)
53
54int
55main(int argc, char *argv[])
56{
57
58	printf("1..2\n");
59
60	test_invalid(0.0, 0.0);
61	test_invalid(1.0, 0.0);
62	test_invalid(INFINITY, 0.0);
63	test_invalid(INFINITY, 1.0);
64	test_invalid(-INFINITY, 1.0);
65	test_invalid(NAN, 1.0);
66	test_invalid(1.0, NAN);
67
68	test(4, 4, 0, 1);
69	test(0, 3.0, 0, 0);
70	testd(0x1p-1074, 1, 0x1p-1074, 0x1p-1074);
71	testf(0x1p-149, 1, 0x1p-149, 0x1p-149);
72	test(3.0, 4, -1, 1);
73	test(3.0, -4, -1, -1);
74	testd(275 * 1193040, 275, 0, 1193040);
75	test(4.5 * 7.5, 4.5, -2.25, 8);	/* we should get the even one */
76	testf(0x1.9044f6p-1, 0x1.ce662ep-1, -0x1.f109cp-4, 1);
77#if LDBL_MANT_DIG > 53
78	testl(-0x1.23456789abcdefp-2000L, 0x1.fedcba987654321p-2000L,
79	      0x1.b72ea61d950c862p-2001L, -1);
80#endif
81
82	printf("ok 1 - rem\n");
83
84	/*
85	 * The actual quotient here is 864062210.50000003..., but
86	 * double-precision division gets -8.64062210.5, which rounds
87	 * the wrong way.  This test ensures that remquo() is smart
88	 * enough to get the low-order bit right.
89	 */
90	testd(-0x1.98260f22fc6dep-302, 0x1.fb3167c430a13p-332,
91	    0x1.fb3165b82de72p-333, -864062211);
92	/* Even harder cases with greater exponent separation */
93	test(0x1.fp100, 0x1.ep-40, -0x1.cp-41, 143165577);
94	testd(-0x1.abcdefp120, 0x1.87654321p-120,
95	    -0x1.69c78ec4p-121, -63816414);
96
97	printf("ok 2 - rem\n");
98
99	return (0);
100}
101
102static void
103test_invalid(long double x, long double y)
104{
105	int q;
106
107	q = 0xdeadbeef;
108
109	assert(isnan(remainder(x, y)));
110	assert(isnan(remquo(x, y, &q)));
111#ifdef STRICT
112	assert(q == 0xdeadbeef);
113#endif
114
115	assert(isnan(remainderf(x, y)));
116	assert(isnan(remquof(x, y, &q)));
117#ifdef STRICT
118	assert(q == 0xdeadbeef);
119#endif
120
121	assert(isnan(remainderl(x, y)));
122	assert(isnan(remquol(x, y, &q)));
123#ifdef STRICT
124	assert(q == 0xdeadbeef);
125#endif
126}
127
128/* 0x012345 ==> 0x01ffff */
129static inline int
130mask(int x)
131{
132	return ((unsigned)~0 >> (32 - fls(x)));
133}
134
135static void
136testl(long double x, long double y, long double expected_rem, int expected_quo)
137{
138	int q;
139
140	q = random();
141	assert(remainderl(x, y) == expected_rem);
142	assert(remquol(x, y, &q) == expected_rem);
143	assert((q & 0x7) == (expected_quo & 0x7));
144	if (q != 0) {
145		assert((q > 0) ^ !(expected_quo > 0));
146		q = abs(q);
147		assert(q == (abs(expected_quo) & mask(q)));
148	}
149}
150
151static void
152testd(double x, double y, double expected_rem, int expected_quo)
153{
154	int q;
155
156	q = random();
157	assert(remainder(x, y) == expected_rem);
158	assert(remquo(x, y, &q) == expected_rem);
159	assert((q & 0x7) == (expected_quo & 0x7));
160	if (q != 0) {
161		assert((q > 0) ^ !(expected_quo > 0));
162		q = abs(q);
163		assert(q == (abs(expected_quo) & mask(q)));
164	}
165}
166
167static void
168testf(float x, float y, float expected_rem, int expected_quo)
169{
170	int q;
171
172	q = random();
173	assert(remainderf(x, y) == expected_rem);
174	assert(remquof(x, y, &q) == expected_rem);
175	assert((q & 0x7) == (expected_quo & 0x7));
176	if (q != 0) {
177		assert((q > 0) ^ !(expected_quo > 0));
178		q = abs(q);
179		assert((q & mask(q)) == (abs(expected_quo) & mask(q)));
180	}
181}
182