xref: /freebsd/lib/msun/tests/csqrt_test.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Copyright (c) 2007 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 csqrt{,f}()
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 
36 #include <assert.h>
37 #include <complex.h>
38 #include <float.h>
39 #include <math.h>
40 #include <stdio.h>
41 
42 #include "test-utils.h"
43 
44 /*
45  * This is a test hook that can point to csqrtl(), _csqrt(), or to _csqrtf().
46  * The latter two convert to float or double, respectively, and test csqrtf()
47  * and csqrt() with the same arguments.
48  */
49 static long double complex (*t_csqrt)(long double complex);
50 
51 static long double complex
52 _csqrtf(long double complex d)
53 {
54 
55 	return (csqrtf((float complex)d));
56 }
57 
58 static long double complex
59 _csqrt(long double complex d)
60 {
61 
62 	return (csqrt((double complex)d));
63 }
64 
65 #pragma	STDC CX_LIMITED_RANGE	OFF
66 
67 /*
68  * Compare d1 and d2 using special rules: NaN == NaN and +0 != -0.
69  * Fail an assertion if they differ.
70  */
71 static void
72 assert_equal(long double complex d1, long double complex d2)
73 {
74 
75 	assert(cfpequal(d1, d2));
76 }
77 
78 /*
79  * Test csqrt for some finite arguments where the answer is exact.
80  * (We do not test if it produces correctly rounded answers when the
81  * result is inexact, nor do we check whether it throws spurious
82  * exceptions.)
83  */
84 static void
85 test_finite(void)
86 {
87 	static const double tests[] = {
88 	     /* csqrt(a + bI) = x + yI */
89 	     /* a	b	x	y */
90 		0,	8,	2,	2,
91 		0,	-8,	2,	-2,
92 		4,	0,	2,	0,
93 		-4,	0,	0,	2,
94 		3,	4,	2,	1,
95 		3,	-4,	2,	-1,
96 		-3,	4,	1,	2,
97 		-3,	-4,	1,	-2,
98 		5,	12,	3,	2,
99 		7,	24,	4,	3,
100 		9,	40,	5,	4,
101 		11,	60,	6,	5,
102 		13,	84,	7,	6,
103 		33,	56,	7,	4,
104 		39,	80,	8,	5,
105 		65,	72,	9,	4,
106 		987,	9916,	74,	67,
107 		5289,	6640,	83,	40,
108 		460766389075.0, 16762287900.0, 678910, 12345
109 	};
110 	/*
111 	 * We also test some multiples of the above arguments. This
112 	 * array defines which multiples we use. Note that these have
113 	 * to be small enough to not cause overflow for float precision
114 	 * with all of the constants in the above table.
115 	 */
116 	static const double mults[] = {
117 		1,
118 		2,
119 		3,
120 		13,
121 		16,
122 		0x1.p30,
123 		0x1.p-30,
124 	};
125 
126 	double a, b;
127 	double x, y;
128 	unsigned i, j;
129 
130 	for (i = 0; i < nitems(tests); i += 4) {
131 		for (j = 0; j < nitems(mults); j++) {
132 			a = tests[i] * mults[j] * mults[j];
133 			b = tests[i + 1] * mults[j] * mults[j];
134 			x = tests[i + 2] * mults[j];
135 			y = tests[i + 3] * mults[j];
136 			assert(t_csqrt(CMPLXL(a, b)) == CMPLXL(x, y));
137 		}
138 	}
139 
140 }
141 
142 /*
143  * Test the handling of +/- 0.
144  */
145 static void
146 test_zeros(void)
147 {
148 
149 	assert_equal(t_csqrt(CMPLXL(0.0, 0.0)), CMPLXL(0.0, 0.0));
150 	assert_equal(t_csqrt(CMPLXL(-0.0, 0.0)), CMPLXL(0.0, 0.0));
151 	assert_equal(t_csqrt(CMPLXL(0.0, -0.0)), CMPLXL(0.0, -0.0));
152 	assert_equal(t_csqrt(CMPLXL(-0.0, -0.0)), CMPLXL(0.0, -0.0));
153 }
154 
155 /*
156  * Test the handling of infinities when the other argument is not NaN.
157  */
158 static void
159 test_infinities(void)
160 {
161 	static const double vals[] = {
162 		0.0,
163 		-0.0,
164 		42.0,
165 		-42.0,
166 		INFINITY,
167 		-INFINITY,
168 	};
169 
170 	unsigned i;
171 
172 	for (i = 0; i < nitems(vals); i++) {
173 		if (isfinite(vals[i])) {
174 			assert_equal(t_csqrt(CMPLXL(-INFINITY, vals[i])),
175 			    CMPLXL(0.0, copysignl(INFINITY, vals[i])));
176 			assert_equal(t_csqrt(CMPLXL(INFINITY, vals[i])),
177 			    CMPLXL(INFINITY, copysignl(0.0, vals[i])));
178 		}
179 		assert_equal(t_csqrt(CMPLXL(vals[i], INFINITY)),
180 		    CMPLXL(INFINITY, INFINITY));
181 		assert_equal(t_csqrt(CMPLXL(vals[i], -INFINITY)),
182 		    CMPLXL(INFINITY, -INFINITY));
183 	}
184 }
185 
186 /*
187  * Test the handling of NaNs.
188  */
189 static void
190 test_nans(void)
191 {
192 
193 	assert(creall(t_csqrt(CMPLXL(INFINITY, NAN))) == INFINITY);
194 	assert(isnan(cimagl(t_csqrt(CMPLXL(INFINITY, NAN)))));
195 
196 	assert(isnan(creall(t_csqrt(CMPLXL(-INFINITY, NAN)))));
197 	assert(isinf(cimagl(t_csqrt(CMPLXL(-INFINITY, NAN)))));
198 
199 	assert_equal(t_csqrt(CMPLXL(NAN, INFINITY)),
200 		     CMPLXL(INFINITY, INFINITY));
201 	assert_equal(t_csqrt(CMPLXL(NAN, -INFINITY)),
202 		     CMPLXL(INFINITY, -INFINITY));
203 
204 	assert_equal(t_csqrt(CMPLXL(0.0, NAN)), CMPLXL(NAN, NAN));
205 	assert_equal(t_csqrt(CMPLXL(-0.0, NAN)), CMPLXL(NAN, NAN));
206 	assert_equal(t_csqrt(CMPLXL(42.0, NAN)), CMPLXL(NAN, NAN));
207 	assert_equal(t_csqrt(CMPLXL(-42.0, NAN)), CMPLXL(NAN, NAN));
208 	assert_equal(t_csqrt(CMPLXL(NAN, 0.0)), CMPLXL(NAN, NAN));
209 	assert_equal(t_csqrt(CMPLXL(NAN, -0.0)), CMPLXL(NAN, NAN));
210 	assert_equal(t_csqrt(CMPLXL(NAN, 42.0)), CMPLXL(NAN, NAN));
211 	assert_equal(t_csqrt(CMPLXL(NAN, -42.0)), CMPLXL(NAN, NAN));
212 	assert_equal(t_csqrt(CMPLXL(NAN, NAN)), CMPLXL(NAN, NAN));
213 }
214 
215 /*
216  * Test whether csqrt(a + bi) works for inputs that are large enough to
217  * cause overflow in hypot(a, b) + a. In this case we are using
218  *	csqrt(115 + 252*I) == 14 + 9*I
219  * scaled up to near MAX_EXP.
220  */
221 static void
222 test_overflow(int maxexp)
223 {
224 	long double a, b;
225 	long double complex result;
226 
227 	a = ldexpl(115 * 0x1p-8, maxexp);
228 	b = ldexpl(252 * 0x1p-8, maxexp);
229 	result = t_csqrt(CMPLXL(a, b));
230 	assert(creall(result) == ldexpl(14 * 0x1p-4, maxexp / 2));
231 	assert(cimagl(result) == ldexpl(9 * 0x1p-4, maxexp / 2));
232 }
233 
234 int
235 main(void)
236 {
237 
238 	printf("1..15\n");
239 
240 	/* Test csqrt() */
241 	t_csqrt = _csqrt;
242 
243 	test_finite();
244 	printf("ok 1 - csqrt\n");
245 
246 	test_zeros();
247 	printf("ok 2 - csqrt\n");
248 
249 	test_infinities();
250 	printf("ok 3 - csqrt\n");
251 
252 	test_nans();
253 	printf("ok 4 - csqrt\n");
254 
255 	test_overflow(DBL_MAX_EXP);
256 	printf("ok 5 - csqrt\n");
257 
258 	/* Now test csqrtf() */
259 	t_csqrt = _csqrtf;
260 
261 	test_finite();
262 	printf("ok 6 - csqrt\n");
263 
264 	test_zeros();
265 	printf("ok 7 - csqrt\n");
266 
267 	test_infinities();
268 	printf("ok 8 - csqrt\n");
269 
270 	test_nans();
271 	printf("ok 9 - csqrt\n");
272 
273 	test_overflow(FLT_MAX_EXP);
274 	printf("ok 10 - csqrt\n");
275 
276 	/* Now test csqrtl() */
277 	t_csqrt = csqrtl;
278 
279 	test_finite();
280 	printf("ok 11 - csqrt\n");
281 
282 	test_zeros();
283 	printf("ok 12 - csqrt\n");
284 
285 	test_infinities();
286 	printf("ok 13 - csqrt\n");
287 
288 	test_nans();
289 	printf("ok 14 - csqrt\n");
290 
291 	test_overflow(LDBL_MAX_EXP);
292 	printf("ok 15 - csqrt\n");
293 
294 	return (0);
295 }
296