xref: /freebsd/lib/msun/tests/rem_test.c (revision 02e9120893770924227138ba49df1edb3896112a)
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 #include <float.h>
35 #include <math.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <strings.h>
39 
40 #include "test-utils.h"
41 
42 static void test_invalid(long double, long double);
43 static void testl(long double, long double, long double, int);
44 static void testd(double, double, double, int);
45 static void testf(float, float, float, int);
46 
47 #define	test(x, y, e_r, e_q) do {	\
48 	testl(x, y, e_r, e_q);		\
49 	testd(x, y, e_r, e_q);		\
50 	testf(x, y, e_r, e_q);		\
51 } while (0)
52 
53 ATF_TC_WITHOUT_HEAD(rem1);
54 ATF_TC_BODY(rem1, tc)
55 {
56 	test_invalid(0.0, 0.0);
57 	test_invalid(1.0, 0.0);
58 	test_invalid(INFINITY, 0.0);
59 	test_invalid(INFINITY, 1.0);
60 	test_invalid(-INFINITY, 1.0);
61 	test_invalid(NAN, 1.0);
62 	test_invalid(1.0, NAN);
63 
64 	test(4, 4, 0, 1);
65 	test(0, 3.0, 0, 0);
66 	testd(0x1p-1074, 1, 0x1p-1074, 0);
67 	testf(0x1p-149, 1, 0x1p-149, 0);
68 	test(3.0, 4, -1, 1);
69 	test(3.0, -4, -1, -1);
70 	testd(275 * 1193040, 275, 0, 1193040);
71 	test(4.5 * 7.5, 4.5, -2.25, 8); /* we should get the even one */
72 	testf(0x1.9044f6p-1, 0x1.ce662ep-1, -0x1.f109cp-4, 1);
73 #if LDBL_MANT_DIG > 53
74 	testl(-0x1.23456789abcdefp-2000L, 0x1.fedcba987654321p-2000L,
75 	    0x1.b72ea61d950c862p-2001L, -1);
76 #endif
77 }
78 
79 ATF_TC_WITHOUT_HEAD(rem2);
80 ATF_TC_BODY(rem2, tc)
81 {
82 	/*
83 	 * The actual quotient here is 864062210.50000003..., but
84 	 * double-precision division gets -8.64062210.5, which rounds
85 	 * the wrong way.  This test ensures that remquo() is smart
86 	 * enough to get the low-order bit right.
87 	 */
88 	testd(-0x1.98260f22fc6dep-302, 0x1.fb3167c430a13p-332,
89 	    0x1.fb3165b82de72p-333, -864062211);
90 	/* Even harder cases with greater exponent separation */
91 	test(0x1.fp100, 0x1.ep-40, -0x1.cp-41, 143165577);
92 	testd(-0x1.abcdefp120, 0x1.87654321p-120, -0x1.69c78ec4p-121,
93 	    -63816414);
94 }
95 
96 ATF_TC_WITHOUT_HEAD(rem3);
97 ATF_TC_BODY(rem3, tc)
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 
106 static void
107 test_invalid(long double x, long double y)
108 {
109 	int q;
110 
111 	q = 0xdeadbeef;
112 
113 	ATF_CHECK(isnan(remainder(x, y)));
114 	ATF_CHECK(isnan(remquo(x, y, &q)));
115 #ifdef STRICT
116 	ATF_CHECK(q == 0xdeadbeef);
117 #endif
118 
119 	ATF_CHECK(isnan(remainderf(x, y)));
120 	ATF_CHECK(isnan(remquof(x, y, &q)));
121 #ifdef STRICT
122 	ATF_CHECK(q == 0xdeadbeef);
123 #endif
124 
125 	ATF_CHECK(isnan(remainderl(x, y)));
126 	ATF_CHECK(isnan(remquol(x, y, &q)));
127 #ifdef STRICT
128 	ATF_CHECK(q == 0xdeadbeef);
129 #endif
130 }
131 
132 /* 0x012345 ==> 0x01ffff */
133 static inline int
134 mask(int x)
135 {
136 	return ((unsigned)~0 >> (32 - fls(x)));
137 }
138 
139 static void
140 testl(long double x, long double y, long double expected_rem, int expected_quo)
141 {
142 	int q;
143 	long double rem;
144 
145 	q = random();
146 	rem = remainderl(x, y);
147 	ATF_CHECK(rem == expected_rem);
148 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
149 	rem = remquol(x, y, &q);
150 	ATF_CHECK(rem == expected_rem);
151 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
152 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
153 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
154 	if (q != 0) {
155 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
156 		q = abs(q);
157 		ATF_CHECK(q == (abs(expected_quo) & mask(q)));
158 	}
159 }
160 
161 static void
162 testd(double x, double y, double expected_rem, int expected_quo)
163 {
164 	int q;
165 	double rem;
166 
167 	q = random();
168 	rem = remainder(x, y);
169 	ATF_CHECK(rem == expected_rem);
170 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
171 	rem = remquo(x, y, &q);
172 	ATF_CHECK(rem == expected_rem);
173 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
174 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
175 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
176 	if (q != 0) {
177 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
178 		q = abs(q);
179 		ATF_CHECK(q == (abs(expected_quo) & mask(q)));
180 	}
181 }
182 
183 static void
184 testf(float x, float y, float expected_rem, int expected_quo)
185 {
186 	int q;
187 	float rem;
188 
189 	q = random();
190 	rem = remainderf(x, y);
191 	ATF_CHECK(rem == expected_rem);
192 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
193 	rem = remquof(x, y, &q);
194 	ATF_CHECK(rem == expected_rem);
195 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
196 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
197 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
198 	if (q != 0) {
199 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
200 		q = abs(q);
201 		ATF_CHECK((q & mask(q)) == (abs(expected_quo) & mask(q)));
202 	}
203 }
204 
205 ATF_TP_ADD_TCS(tp)
206 {
207 	ATF_TP_ADD_TC(tp, rem1);
208 	ATF_TP_ADD_TC(tp, rem2);
209 	ATF_TP_ADD_TC(tp, rem3);
210 
211 	return (atf_no_error());
212 }
213