xref: /freebsd/lib/msun/tests/rem_test.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
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 <float.h>
37 #include <math.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <strings.h>
41 
42 #include "test-utils.h"
43 
44 static void test_invalid(long double, long double);
45 static void testl(long double, long double, long double, int);
46 static void testd(double, double, double, int);
47 static void testf(float, float, float, int);
48 
49 #define	test(x, y, e_r, e_q) do {	\
50 	testl(x, y, e_r, e_q);		\
51 	testd(x, y, e_r, e_q);		\
52 	testf(x, y, e_r, e_q);		\
53 } while (0)
54 
55 ATF_TC_WITHOUT_HEAD(rem1);
56 ATF_TC_BODY(rem1, tc)
57 {
58 	test_invalid(0.0, 0.0);
59 	test_invalid(1.0, 0.0);
60 	test_invalid(INFINITY, 0.0);
61 	test_invalid(INFINITY, 1.0);
62 	test_invalid(-INFINITY, 1.0);
63 	test_invalid(NAN, 1.0);
64 	test_invalid(1.0, NAN);
65 
66 	test(4, 4, 0, 1);
67 	test(0, 3.0, 0, 0);
68 	testd(0x1p-1074, 1, 0x1p-1074, 0);
69 	testf(0x1p-149, 1, 0x1p-149, 0);
70 	test(3.0, 4, -1, 1);
71 	test(3.0, -4, -1, -1);
72 	testd(275 * 1193040, 275, 0, 1193040);
73 	test(4.5 * 7.5, 4.5, -2.25, 8); /* we should get the even one */
74 	testf(0x1.9044f6p-1, 0x1.ce662ep-1, -0x1.f109cp-4, 1);
75 #if LDBL_MANT_DIG > 53
76 	testl(-0x1.23456789abcdefp-2000L, 0x1.fedcba987654321p-2000L,
77 	    0x1.b72ea61d950c862p-2001L, -1);
78 #endif
79 }
80 
81 ATF_TC_WITHOUT_HEAD(rem2);
82 ATF_TC_BODY(rem2, tc)
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, -0x1.69c78ec4p-121,
95 	    -63816414);
96 }
97 
98 ATF_TC_WITHOUT_HEAD(rem3);
99 ATF_TC_BODY(rem3, tc)
100 {
101 	test(0x1.66666cp+120, 0x1p+71, 0.0, 1476395008);
102 	testd(-0x1.0000000000003p+0, 0x1.0000000000003p+0, -0.0, -1);
103 	testl(-0x1.0000000000003p+0, 0x1.0000000000003p+0, -0.0, -1);
104 	testd(-0x1.0000000000001p-749, 0x1.4p-1072, 0x1p-1074, -1288490189);
105 	testl(-0x1.0000000000001p-749, 0x1.4p-1072, 0x1p-1074, -1288490189);
106 }
107 
108 static void
109 test_invalid(long double x, long double y)
110 {
111 	int q;
112 
113 	q = 0xdeadbeef;
114 
115 	ATF_CHECK(isnan(remainder(x, y)));
116 	ATF_CHECK(isnan(remquo(x, y, &q)));
117 #ifdef STRICT
118 	ATF_CHECK(q == 0xdeadbeef);
119 #endif
120 
121 	ATF_CHECK(isnan(remainderf(x, y)));
122 	ATF_CHECK(isnan(remquof(x, y, &q)));
123 #ifdef STRICT
124 	ATF_CHECK(q == 0xdeadbeef);
125 #endif
126 
127 	ATF_CHECK(isnan(remainderl(x, y)));
128 	ATF_CHECK(isnan(remquol(x, y, &q)));
129 #ifdef STRICT
130 	ATF_CHECK(q == 0xdeadbeef);
131 #endif
132 }
133 
134 /* 0x012345 ==> 0x01ffff */
135 static inline int
136 mask(int x)
137 {
138 	return ((unsigned)~0 >> (32 - fls(x)));
139 }
140 
141 static void
142 testl(long double x, long double y, long double expected_rem, int expected_quo)
143 {
144 	int q;
145 	long double rem;
146 
147 	q = random();
148 	rem = remainderl(x, y);
149 	ATF_CHECK(rem == expected_rem);
150 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
151 	rem = remquol(x, y, &q);
152 	ATF_CHECK(rem == expected_rem);
153 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
154 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
155 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
156 	if (q != 0) {
157 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
158 		q = abs(q);
159 		ATF_CHECK(q == (abs(expected_quo) & mask(q)));
160 	}
161 }
162 
163 static void
164 testd(double x, double y, double expected_rem, int expected_quo)
165 {
166 	int q;
167 	double rem;
168 
169 	q = random();
170 	rem = remainder(x, y);
171 	ATF_CHECK(rem == expected_rem);
172 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
173 	rem = remquo(x, y, &q);
174 	ATF_CHECK(rem == expected_rem);
175 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
176 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
177 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
178 	if (q != 0) {
179 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
180 		q = abs(q);
181 		ATF_CHECK(q == (abs(expected_quo) & mask(q)));
182 	}
183 }
184 
185 static void
186 testf(float x, float y, float expected_rem, int expected_quo)
187 {
188 	int q;
189 	float rem;
190 
191 	q = random();
192 	rem = remainderf(x, y);
193 	ATF_CHECK(rem == expected_rem);
194 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
195 	rem = remquof(x, y, &q);
196 	ATF_CHECK(rem == expected_rem);
197 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
198 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
199 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
200 	if (q != 0) {
201 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
202 		q = abs(q);
203 		ATF_CHECK((q & mask(q)) == (abs(expected_quo) & mask(q)));
204 	}
205 }
206 
207 ATF_TP_ADD_TCS(tp)
208 {
209 	ATF_TP_ADD_TC(tp, rem1);
210 	ATF_TP_ADD_TC(tp, rem2);
211 	ATF_TP_ADD_TC(tp, rem3);
212 
213 	return (atf_no_error());
214 }
215