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: stable/11/lib/msun/tests/rem_test.c 315121 2017-03-12 04:52:09Z ngie $");
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(void)
56{
57
58	printf("1..3\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, 0);
71	testf(0x1p-149, 1, 0x1p-149, 0);
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	test(0x1.66666cp+120, 0x1p+71, 0.0, 1476395008);
100	testd(-0x1.0000000000003p+0, 0x1.0000000000003p+0, -0.0, -1);
101	testl(-0x1.0000000000003p+0, 0x1.0000000000003p+0, -0.0, -1);
102	testd(-0x1.0000000000001p-749, 0x1.4p-1072, 0x1p-1074, -1288490189);
103	testl(-0x1.0000000000001p-749, 0x1.4p-1072, 0x1p-1074, -1288490189);
104
105	printf("ok 3 - rem\n");
106
107	return (0);
108}
109
110static void
111test_invalid(long double x, long double y)
112{
113	int q;
114
115	q = 0xdeadbeef;
116
117	assert(isnan(remainder(x, y)));
118	assert(isnan(remquo(x, y, &q)));
119#ifdef STRICT
120	assert(q == 0xdeadbeef);
121#endif
122
123	assert(isnan(remainderf(x, y)));
124	assert(isnan(remquof(x, y, &q)));
125#ifdef STRICT
126	assert(q == 0xdeadbeef);
127#endif
128
129	assert(isnan(remainderl(x, y)));
130	assert(isnan(remquol(x, y, &q)));
131#ifdef STRICT
132	assert(q == 0xdeadbeef);
133#endif
134}
135
136/* 0x012345 ==> 0x01ffff */
137static inline int
138mask(int x)
139{
140	return ((unsigned)~0 >> (32 - fls(x)));
141}
142
143static void
144testl(long double x, long double y, long double expected_rem, int expected_quo)
145{
146	int q;
147	long double rem;
148
149	q = random();
150	rem = remainderl(x, y);
151	assert(rem == expected_rem);
152	assert(!signbit(rem) == !signbit(expected_rem));
153	rem = remquol(x, y, &q);
154	assert(rem == expected_rem);
155	assert(!signbit(rem) == !signbit(expected_rem));
156	assert((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
157	assert((q & 0x7) == (expected_quo & 0x7));
158	if (q != 0) {
159		assert((q > 0) ^ !(expected_quo > 0));
160		q = abs(q);
161		assert(q == (abs(expected_quo) & mask(q)));
162	}
163}
164
165static void
166testd(double x, double y, double expected_rem, int expected_quo)
167{
168	int q;
169	double rem;
170
171	q = random();
172	rem = remainder(x, y);
173	assert(rem == expected_rem);
174	assert(!signbit(rem) == !signbit(expected_rem));
175	rem = remquo(x, y, &q);
176	assert(rem == expected_rem);
177	assert(!signbit(rem) == !signbit(expected_rem));
178	assert((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
179	assert((q & 0x7) == (expected_quo & 0x7));
180	if (q != 0) {
181		assert((q > 0) ^ !(expected_quo > 0));
182		q = abs(q);
183		assert(q == (abs(expected_quo) & mask(q)));
184	}
185}
186
187static void
188testf(float x, float y, float expected_rem, int expected_quo)
189{
190	int q;
191	float rem;
192
193	q = random();
194	rem = remainderf(x, y);
195	assert(rem == expected_rem);
196	assert(!signbit(rem) == !signbit(expected_rem));
197	rem = remquof(x, y, &q);
198	assert(rem == expected_rem);
199	assert(!signbit(rem) == !signbit(expected_rem));
200	assert((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
201	assert((q & 0x7) == (expected_quo & 0x7));
202	if (q != 0) {
203		assert((q > 0) ^ !(expected_quo > 0));
204		q = abs(q);
205		assert((q & mask(q)) == (abs(expected_quo) & mask(q)));
206	}
207}
208