xref: /freebsd/lib/msun/tests/nearbyint_test.c (revision 4b9d605768acabc460aa6dcfe8a1f8db35b16794)
1 /*-
2  * Copyright (c) 2010 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  * Tests for nearbyint{,f,l}()
29  *
30  * TODO:
31  * - adapt tests for rint(3)
32  * - tests for harder values (more mantissa bits than float)
33  */
34 
35 #include <sys/param.h>
36 #include <fenv.h>
37 #include <math.h>
38 #include <stdio.h>
39 
40 #include "test-utils.h"
41 
42 static const int rmodes[] = {
43 	FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, FE_TOWARDZERO,
44 };
45 
46 /* Make sure we're testing the library, not some broken compiler built-ins. */
47 static double (*libnearbyint)(double) = nearbyint;
48 static float (*libnearbyintf)(float) = nearbyintf;
49 static long double (*libnearbyintl)(long double) = nearbyintl;
50 #define nearbyintf libnearbyintf
51 #define nearbyint libnearbyint
52 #define nearbyintl libnearbyintl
53 
54 static const struct {
55 	float in;
56 	float out[3];	/* one answer per rounding mode except towardzero */
57 } tests[] = {
58 /* input	output (expected) */
59     { 0.0,	{ 0.0, 0.0, 0.0 }},
60     { 0.5,	{ 0.0, 0.0, 1.0 }},
61     { M_PI,	{ 3.0, 3.0, 4.0 }},
62     { 65536.5,	{ 65536, 65536, 65537 }},
63     { INFINITY,	{ INFINITY, INFINITY, INFINITY }},
64     { NAN,	{ NAN, NAN, NAN }},
65 };
66 
67 /* Get the appropriate result for the current rounding mode. */
68 static float
69 get_output(int testindex, int rmodeindex, int negative)
70 {
71 	double out;
72 
73 	if (negative) {	/* swap downwards and upwards if input is negative */
74 		if (rmodeindex == 1)
75 			rmodeindex = 2;
76 		else if (rmodeindex == 2)
77 			rmodeindex = 1;
78 	}
79 	if (rmodeindex == 3) /* FE_TOWARDZERO uses the value for downwards */
80 		rmodeindex = 1;
81 	out = tests[testindex].out[rmodeindex];
82 	return (negative ? -out : out);
83 }
84 
85 static void
86 test_nearby(int testindex)
87 {
88 	float in, out;
89 	unsigned i;
90 
91 	for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
92 		ATF_REQUIRE_EQ(0, fesetround(rmodes[i]));
93 		ATF_REQUIRE_EQ(0, feclearexcept(ALL_STD_EXCEPT));
94 
95 		in = tests[testindex].in;
96 		out = get_output(testindex, i, 0);
97 		CHECK_FPEQUAL(out, libnearbyintf(in));
98 		CHECK_FPEQUAL(out, nearbyint(in));
99 		CHECK_FPEQUAL(out, nearbyintl(in));
100 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
101 
102 		in = -tests[testindex].in;
103 		out = get_output(testindex, i, 1);
104 		CHECK_FPEQUAL(out, nearbyintf(in));
105 		CHECK_FPEQUAL(out, nearbyint(in));
106 		CHECK_FPEQUAL(out, nearbyintl(in));
107 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
108 	}
109 }
110 
111 static void
112 test_modf(int testindex)
113 {
114 	float in, out;
115 	float ipartf, ipart_expected;
116 	double ipart;
117 	long double ipartl;
118 	unsigned i;
119 
120 	for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
121 		ATF_REQUIRE_EQ(0, fesetround(rmodes[i]));
122 		ATF_REQUIRE_EQ(0, feclearexcept(ALL_STD_EXCEPT));
123 
124 		in = tests[testindex].in;
125 		ipart_expected = tests[testindex].out[1];
126 		out = copysignf(
127 		    isinf(ipart_expected) ? 0.0 : in - ipart_expected, in);
128 		ipartl = ipart = ipartf = 42.0;
129 
130 		CHECK_FPEQUAL(out, modff(in, &ipartf));
131 		CHECK_FPEQUAL(ipart_expected, ipartf);
132 		CHECK_FPEQUAL(out, modf(in, &ipart));
133 		CHECK_FPEQUAL(ipart_expected, ipart);
134 		CHECK_FPEQUAL(out, modfl(in, &ipartl));
135 		CHECK_FPEQUAL(ipart_expected, ipartl);
136 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
137 
138 		in = -in;
139 		ipart_expected = -ipart_expected;
140 		out = -out;
141 		ipartl = ipart = ipartf = 42.0;
142 		CHECK_FPEQUAL(out, modff(in, &ipartf));
143 		CHECK_FPEQUAL(ipart_expected, ipartf);
144 		CHECK_FPEQUAL(out, modf(in, &ipart));
145 		CHECK_FPEQUAL(ipart_expected, ipart);
146 		CHECK_FPEQUAL(out, modfl(in, &ipartl));
147 		CHECK_FPEQUAL(ipart_expected, ipartl);
148 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
149 	}
150 }
151 
152 ATF_TC_WITHOUT_HEAD(nearbyint);
153 ATF_TC_BODY(nearbyint, tc)
154 {
155 	unsigned i;
156 
157 	for (i = 0; i < nitems(tests); i++) {
158 		test_nearby(i);
159 		test_modf(i);
160 	}
161 }
162 
163 ATF_TP_ADD_TCS(tp)
164 {
165 	ATF_TP_ADD_TC(tp, nearbyint);
166 
167 	return (atf_no_error());
168 }
169