xref: /freebsd/lib/msun/tests/rem_test.c (revision 62a52c15422470f97fc7b311d89c83f910bcc1b1)
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 <float.h>
34 #include <math.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <strings.h>
38 
39 #include "test-utils.h"
40 
41 static void test_invalid(long double, long double);
42 static void testl(long double, long double, long double, int);
43 static void testd(double, double, double, int);
44 static void testf(float, float, float, int);
45 
46 #define	test(x, y, e_r, e_q) do {	\
47 	testl(x, y, e_r, e_q);		\
48 	testd(x, y, e_r, e_q);		\
49 	testf(x, y, e_r, e_q);		\
50 } while (0)
51 
52 ATF_TC_WITHOUT_HEAD(rem1);
53 ATF_TC_BODY(rem1, tc)
54 {
55 	test_invalid(0.0, 0.0);
56 	test_invalid(1.0, 0.0);
57 	test_invalid(INFINITY, 0.0);
58 	test_invalid(INFINITY, 1.0);
59 	test_invalid(-INFINITY, 1.0);
60 	test_invalid(NAN, 1.0);
61 	test_invalid(1.0, NAN);
62 
63 	test(4, 4, 0, 1);
64 	test(0, 3.0, 0, 0);
65 	testd(0x1p-1074, 1, 0x1p-1074, 0);
66 	testf(0x1p-149, 1, 0x1p-149, 0);
67 	test(3.0, 4, -1, 1);
68 	test(3.0, -4, -1, -1);
69 	testd(275 * 1193040, 275, 0, 1193040);
70 	test(4.5 * 7.5, 4.5, -2.25, 8); /* we should get the even one */
71 	testf(0x1.9044f6p-1, 0x1.ce662ep-1, -0x1.f109cp-4, 1);
72 #if LDBL_MANT_DIG > 53
73 	testl(-0x1.23456789abcdefp-2000L, 0x1.fedcba987654321p-2000L,
74 	    0x1.b72ea61d950c862p-2001L, -1);
75 #endif
76 }
77 
78 ATF_TC_WITHOUT_HEAD(rem2);
79 ATF_TC_BODY(rem2, tc)
80 {
81 	/*
82 	 * The actual quotient here is 864062210.50000003..., but
83 	 * double-precision division gets -8.64062210.5, which rounds
84 	 * the wrong way.  This test ensures that remquo() is smart
85 	 * enough to get the low-order bit right.
86 	 */
87 	testd(-0x1.98260f22fc6dep-302, 0x1.fb3167c430a13p-332,
88 	    0x1.fb3165b82de72p-333, -864062211);
89 	/* Even harder cases with greater exponent separation */
90 	test(0x1.fp100, 0x1.ep-40, -0x1.cp-41, 143165577);
91 	testd(-0x1.abcdefp120, 0x1.87654321p-120, -0x1.69c78ec4p-121,
92 	    -63816414);
93 }
94 
95 ATF_TC_WITHOUT_HEAD(rem3);
96 ATF_TC_BODY(rem3, tc)
97 {
98 	test(0x1.66666cp+120, 0x1p+71, 0.0, 1476395008);
99 	testd(-0x1.0000000000003p+0, 0x1.0000000000003p+0, -0.0, -1);
100 	testl(-0x1.0000000000003p+0, 0x1.0000000000003p+0, -0.0, -1);
101 	testd(-0x1.0000000000001p-749, 0x1.4p-1072, 0x1p-1074, -1288490189);
102 	testl(-0x1.0000000000001p-749, 0x1.4p-1072, 0x1p-1074, -1288490189);
103 }
104 
105 static void
106 test_invalid(long double x, long double y)
107 {
108 	int q;
109 
110 	q = 0xdeadbeef;
111 
112 	ATF_CHECK(isnan(remainder(x, y)));
113 	ATF_CHECK(isnan(remquo(x, y, &q)));
114 #ifdef STRICT
115 	ATF_CHECK(q == 0xdeadbeef);
116 #endif
117 
118 	ATF_CHECK(isnan(remainderf(x, y)));
119 	ATF_CHECK(isnan(remquof(x, y, &q)));
120 #ifdef STRICT
121 	ATF_CHECK(q == 0xdeadbeef);
122 #endif
123 
124 	ATF_CHECK(isnan(remainderl(x, y)));
125 	ATF_CHECK(isnan(remquol(x, y, &q)));
126 #ifdef STRICT
127 	ATF_CHECK(q == 0xdeadbeef);
128 #endif
129 }
130 
131 /* 0x012345 ==> 0x01ffff */
132 static inline int
133 mask(int x)
134 {
135 	return ((unsigned)~0 >> (32 - fls(x)));
136 }
137 
138 static void
139 testl(long double x, long double y, long double expected_rem, int expected_quo)
140 {
141 	int q;
142 	long double rem;
143 
144 	q = random();
145 	rem = remainderl(x, y);
146 	ATF_CHECK(rem == expected_rem);
147 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
148 	rem = remquol(x, y, &q);
149 	ATF_CHECK(rem == expected_rem);
150 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
151 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
152 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
153 	if (q != 0) {
154 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
155 		q = abs(q);
156 		ATF_CHECK(q == (abs(expected_quo) & mask(q)));
157 	}
158 }
159 
160 static void
161 testd(double x, double y, double expected_rem, int expected_quo)
162 {
163 	int q;
164 	double rem;
165 
166 	q = random();
167 	rem = remainder(x, y);
168 	ATF_CHECK(rem == expected_rem);
169 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
170 	rem = remquo(x, y, &q);
171 	ATF_CHECK(rem == expected_rem);
172 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
173 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
174 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
175 	if (q != 0) {
176 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
177 		q = abs(q);
178 		ATF_CHECK(q == (abs(expected_quo) & mask(q)));
179 	}
180 }
181 
182 static void
183 testf(float x, float y, float expected_rem, int expected_quo)
184 {
185 	int q;
186 	float rem;
187 
188 	q = random();
189 	rem = remainderf(x, y);
190 	ATF_CHECK(rem == expected_rem);
191 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
192 	rem = remquof(x, y, &q);
193 	ATF_CHECK(rem == expected_rem);
194 	ATF_CHECK(!signbit(rem) == !signbit(expected_rem));
195 	ATF_CHECK((q ^ expected_quo) >= 0); /* sign(q) == sign(expected_quo) */
196 	ATF_CHECK((q & 0x7) == (expected_quo & 0x7));
197 	if (q != 0) {
198 		ATF_CHECK((q > 0) ^ !(expected_quo > 0));
199 		q = abs(q);
200 		ATF_CHECK((q & mask(q)) == (abs(expected_quo) & mask(q)));
201 	}
202 }
203 
204 ATF_TP_ADD_TCS(tp)
205 {
206 	ATF_TP_ADD_TC(tp, rem1);
207 	ATF_TP_ADD_TC(tp, rem2);
208 	ATF_TP_ADD_TC(tp, rem3);
209 
210 	return (atf_no_error());
211 }
212