1 /* $OpenBSD: rem_test.c,v 1.2 2021/12/13 18:04:28 deraadt Exp $ */
2 /*-
3 * Copyright (c) 2005-2008 David Schultz <das@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include "macros.h"
29
30 /*
31 * Test for remainder functions: remainder, remainderf, remainderl,
32 * remquo, remquof, and remquol.
33 * Missing tests: fmod, fmodf.
34 */
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);
ATF_TC_BODY(rem1,tc)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);
ATF_TC_BODY(rem2,tc)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);
ATF_TC_BODY(rem3,tc)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
test_invalid(long double x,long double y)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
mask(int x)136 mask(int x)
137 {
138 return ((unsigned)~0 >> (32 - fls(x)));
139 }
140
141 static void
testl(long double x,long double y,long double expected_rem,int expected_quo)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
testd(double x,double y,double expected_rem,int expected_quo)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
testf(float x,float y,float expected_rem,int expected_quo)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
ATF_TP_ADD_TCS(tp)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