2 * Copyright (c) 2008 David Schultz <das@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
28 * Tests for corner cases in the inverse trigonometric functions. Some
29 * accuracy tests are included as well, but these are very basic
30 * sanity checks, not intended to be comprehensive.
33 #include <sys/cdefs.h>
39 #include "test-utils.h"
41 #pragma STDC FENV_ACCESS ON
44 * Test that a function returns the correct value and sets the
45 * exception flags correctly. A tolerance specifying the maximum
46 * relative error allowed may be specified. For the 'testall'
47 * functions, the tolerance is specified in ulps.
49 * These are macros instead of functions so that assert provides more
50 * meaningful error messages.
52 #define test_tol(func, x, result, tol, excepts) do { \
53 volatile long double _in = (x), _out = (result); \
54 ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT)); \
55 CHECK_FPEQUAL_TOL(func(_in), _out, (tol), CS_BOTH); \
56 CHECK_FP_EXCEPTIONS_MSG(excepts, ALL_STD_EXCEPT, "for %s(%s)", \
59 #define test(func, x, result, excepts) \
60 test_tol(func, (x), (result), 0, (excepts))
62 #define _testall_tol(prefix, x, result, tol, excepts) do { \
63 test_tol(prefix, (double)(x), (double)(result), \
64 (tol) * ldexp(1.0, 1 - DBL_MANT_DIG), (excepts)); \
65 test_tol(prefix##f, (float)(x), (float)(result), \
66 (tol) * ldexpf(1.0, 1 - FLT_MANT_DIG), (excepts)); \
70 #define testall_tol _testall_tol
72 #define testall_tol(prefix, x, result, tol, excepts) do { \
73 _testall_tol(prefix, x, result, tol, excepts); \
74 test_tol(prefix##l, (x), (result), \
75 (tol) * ldexpl(1.0, 1 - LDBL_MANT_DIG), (excepts)); \
79 #define testall(prefix, x, result, excepts) \
80 testall_tol(prefix, (x), (result), 0, (excepts))
82 #define test2_tol(func, y, x, result, tol, excepts) do { \
83 volatile long double _iny = (y), _inx = (x), _out = (result); \
84 ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT)); \
85 CHECK_FPEQUAL_TOL(func(_iny, _inx), _out, (tol), CS_BOTH); \
86 CHECK_FP_EXCEPTIONS_MSG(excepts, ALL_STD_EXCEPT, "for %s(%s)", \
89 #define test2(func, y, x, result, excepts) \
90 test2_tol(func, (y), (x), (result), 0, (excepts))
92 #define _testall2_tol(prefix, y, x, result, tol, excepts) do { \
93 test2_tol(prefix, (double)(y), (double)(x), (double)(result), \
94 (tol) * ldexp(1.0, 1 - DBL_MANT_DIG), (excepts)); \
95 test2_tol(prefix##f, (float)(y), (float)(x), (float)(result), \
96 (tol) * ldexpf(1.0, 1 - FLT_MANT_DIG), (excepts)); \
100 #define testall2_tol _testall2_tol
102 #define testall2_tol(prefix, y, x, result, tol, excepts) do { \
103 _testall2_tol(prefix, y, x, result, tol, excepts); \
104 test2_tol(prefix##l, (y), (x), (result), \
105 (tol) * ldexpl(1.0, 1 - LDBL_MANT_DIG), (excepts)); \
109 #define testall2(prefix, y, x, result, excepts) \
110 testall2_tol(prefix, (y), (x), (result), 0, (excepts))
113 pi = 3.14159265358979323846264338327950280e+00L,
114 pio3 = 1.04719755119659774615421446109316766e+00L,
115 c3pi = 9.42477796076937971538793014983850839e+00L,
116 c7pi = 2.19911485751285526692385036829565196e+01L,
117 c5pio3 = 5.23598775598298873077107230546583851e+00L,
118 sqrt2m1 = 4.14213562373095048801688724209698081e-01L;
122 * Test special case inputs in asin(), acos() and atan(): signed
123 * zeroes, infinities, and NaNs.
125 ATF_TC_WITHOUT_HEAD(special);
126 ATF_TC_BODY(special, tc)
129 testall(asin, 0.0, 0.0, 0);
130 testall(acos, 0.0, pi / 2, FE_INEXACT);
131 testall(atan, 0.0, 0.0, 0);
132 testall(asin, -0.0, -0.0, 0);
133 testall(acos, -0.0, pi / 2, FE_INEXACT);
134 testall(atan, -0.0, -0.0, 0);
136 testall(asin, INFINITY, NAN, FE_INVALID);
137 testall(acos, INFINITY, NAN, FE_INVALID);
138 testall(atan, INFINITY, pi / 2, FE_INEXACT);
139 testall(asin, -INFINITY, NAN, FE_INVALID);
140 testall(acos, -INFINITY, NAN, FE_INVALID);
141 testall(atan, -INFINITY, -pi / 2, FE_INEXACT);
143 testall(asin, NAN, NAN, 0);
144 testall(acos, NAN, NAN, 0);
145 testall(atan, NAN, NAN, 0);
149 * Test special case inputs in atan2(), where the exact value of y/x is
150 * zero or non-finite.
152 ATF_TC_WITHOUT_HEAD(special_atan2);
153 ATF_TC_BODY(special_atan2, tc)
158 testall2(atan2, 0.0, -0.0, pi, FE_INEXACT);
159 testall2(atan2, -0.0, -0.0, -pi, FE_INEXACT);
160 testall2(atan2, 0.0, 0.0, 0.0, 0);
161 testall2(atan2, -0.0, 0.0, -0.0, 0);
163 testall2(atan2, INFINITY, -INFINITY, c3pi / 4, FE_INEXACT);
164 testall2(atan2, -INFINITY, -INFINITY, -c3pi / 4, FE_INEXACT);
165 testall2(atan2, INFINITY, INFINITY, pi / 4, FE_INEXACT);
166 testall2(atan2, -INFINITY, INFINITY, -pi / 4, FE_INEXACT);
168 /* Tests with one input in the range (0, Inf]. */
170 for (e = FLT_MIN_EXP - FLT_MANT_DIG; e <= FLT_MAX_EXP; e++) {
171 test2(atan2f, 0.0, ldexpf(z, e), 0.0, 0);
172 test2(atan2f, -0.0, ldexpf(z, e), -0.0, 0);
173 test2(atan2f, 0.0, ldexpf(-z, e), (float)pi, FE_INEXACT);
174 test2(atan2f, -0.0, ldexpf(-z, e), (float)-pi, FE_INEXACT);
175 test2(atan2f, ldexpf(z, e), 0.0, (float)pi / 2, FE_INEXACT);
176 test2(atan2f, ldexpf(z, e), -0.0, (float)pi / 2, FE_INEXACT);
177 test2(atan2f, ldexpf(-z, e), 0.0, (float)-pi / 2, FE_INEXACT);
178 test2(atan2f, ldexpf(-z, e), -0.0, (float)-pi / 2, FE_INEXACT);
180 for (e = DBL_MIN_EXP - DBL_MANT_DIG; e <= DBL_MAX_EXP; e++) {
181 test2(atan2, 0.0, ldexp(z, e), 0.0, 0);
182 test2(atan2, -0.0, ldexp(z, e), -0.0, 0);
183 test2(atan2, 0.0, ldexp(-z, e), (double)pi, FE_INEXACT);
184 test2(atan2, -0.0, ldexp(-z, e), (double)-pi, FE_INEXACT);
185 test2(atan2, ldexp(z, e), 0.0, (double)pi / 2, FE_INEXACT);
186 test2(atan2, ldexp(z, e), -0.0, (double)pi / 2, FE_INEXACT);
187 test2(atan2, ldexp(-z, e), 0.0, (double)-pi / 2, FE_INEXACT);
188 test2(atan2, ldexp(-z, e), -0.0, (double)-pi / 2, FE_INEXACT);
190 for (e = LDBL_MIN_EXP - LDBL_MANT_DIG; e <= LDBL_MAX_EXP; e++) {
191 test2(atan2l, 0.0, ldexpl(z, e), 0.0, 0);
192 test2(atan2l, -0.0, ldexpl(z, e), -0.0, 0);
193 test2(atan2l, 0.0, ldexpl(-z, e), pi, FE_INEXACT);
194 test2(atan2l, -0.0, ldexpl(-z, e), -pi, FE_INEXACT);
195 test2(atan2l, ldexpl(z, e), 0.0, pi / 2, FE_INEXACT);
196 test2(atan2l, ldexpl(z, e), -0.0, pi / 2, FE_INEXACT);
197 test2(atan2l, ldexpl(-z, e), 0.0, -pi / 2, FE_INEXACT);
198 test2(atan2l, ldexpl(-z, e), -0.0, -pi / 2, FE_INEXACT);
201 /* Tests with one input in the range (0, Inf). */
202 for (e = FLT_MIN_EXP - FLT_MANT_DIG; e <= FLT_MAX_EXP - 1; e++) {
203 test2(atan2f, ldexpf(z, e), INFINITY, 0.0, 0);
204 test2(atan2f, ldexpf(-z,e), INFINITY, -0.0, 0);
205 test2(atan2f, ldexpf(z, e), -INFINITY, (float)pi, FE_INEXACT);
206 test2(atan2f, ldexpf(-z,e), -INFINITY, (float)-pi, FE_INEXACT);
207 test2(atan2f, INFINITY, ldexpf(z,e), (float)pi/2, FE_INEXACT);
208 test2(atan2f, INFINITY, ldexpf(-z,e), (float)pi/2, FE_INEXACT);
209 test2(atan2f, -INFINITY, ldexpf(z,e), (float)-pi/2,FE_INEXACT);
210 test2(atan2f, -INFINITY, ldexpf(-z,e),(float)-pi/2,FE_INEXACT);
212 for (e = DBL_MIN_EXP - DBL_MANT_DIG; e <= DBL_MAX_EXP - 1; e++) {
213 test2(atan2, ldexp(z, e), INFINITY, 0.0, 0);
214 test2(atan2, ldexp(-z,e), INFINITY, -0.0, 0);
215 test2(atan2, ldexp(z, e), -INFINITY, (double)pi, FE_INEXACT);
216 test2(atan2, ldexp(-z,e), -INFINITY, (double)-pi, FE_INEXACT);
217 test2(atan2, INFINITY, ldexp(z,e), (double)pi/2, FE_INEXACT);
218 test2(atan2, INFINITY, ldexp(-z,e), (double)pi/2, FE_INEXACT);
219 test2(atan2, -INFINITY, ldexp(z,e), (double)-pi/2,FE_INEXACT);
220 test2(atan2, -INFINITY, ldexp(-z,e),(double)-pi/2,FE_INEXACT);
222 for (e = LDBL_MIN_EXP - LDBL_MANT_DIG; e <= LDBL_MAX_EXP - 1; e++) {
223 test2(atan2l, ldexpl(z, e), INFINITY, 0.0, 0);
224 test2(atan2l, ldexpl(-z,e), INFINITY, -0.0, 0);
225 test2(atan2l, ldexpl(z, e), -INFINITY, pi, FE_INEXACT);
226 test2(atan2l, ldexpl(-z,e), -INFINITY, -pi, FE_INEXACT);
227 test2(atan2l, INFINITY, ldexpl(z, e), pi / 2, FE_INEXACT);
228 test2(atan2l, INFINITY, ldexpl(-z, e), pi / 2, FE_INEXACT);
229 test2(atan2l, -INFINITY, ldexpl(z, e), -pi / 2, FE_INEXACT);
230 test2(atan2l, -INFINITY, ldexpl(-z, e), -pi / 2, FE_INEXACT);
235 * Test various inputs to asin(), acos() and atan() and verify that the
236 * results are accurate to within 1 ulp.
238 ATF_TC_WITHOUT_HEAD(accuracy);
239 ATF_TC_BODY(accuracy, tc)
242 /* We expect correctly rounded results for these basic cases. */
243 testall(asin, 1.0, pi / 2, FE_INEXACT);
244 testall(acos, 1.0, 0, 0);
245 testall(atan, 1.0, pi / 4, FE_INEXACT);
246 testall(asin, -1.0, -pi / 2, FE_INEXACT);
247 testall(acos, -1.0, pi, FE_INEXACT);
248 testall(atan, -1.0, -pi / 4, FE_INEXACT);
251 * Here we expect answers to be within 1 ulp, although inexactness
252 * in the input, combined with double rounding, could cause larger
256 testall_tol(asin, sqrtl(2) / 2, pi / 4, 1, FE_INEXACT);
257 testall_tol(acos, sqrtl(2) / 2, pi / 4, 1, FE_INEXACT);
258 testall_tol(asin, -sqrtl(2) / 2, -pi / 4, 1, FE_INEXACT);
259 testall_tol(acos, -sqrtl(2) / 2, c3pi / 4, 1, FE_INEXACT);
261 testall_tol(asin, sqrtl(3) / 2, pio3, 1, FE_INEXACT);
262 testall_tol(acos, sqrtl(3) / 2, pio3 / 2, 1, FE_INEXACT);
263 testall_tol(atan, sqrtl(3), pio3, 1, FE_INEXACT);
264 testall_tol(asin, -sqrtl(3) / 2, -pio3, 1, FE_INEXACT);
265 testall_tol(acos, -sqrtl(3) / 2, c5pio3 / 2, 1, FE_INEXACT);
266 testall_tol(atan, -sqrtl(3), -pio3, 1, FE_INEXACT);
268 testall_tol(atan, sqrt2m1, pi / 8, 1, FE_INEXACT);
269 testall_tol(atan, -sqrt2m1, -pi / 8, 1, FE_INEXACT);
273 * Test inputs to atan2() where x is a power of 2. These are easy cases
274 * because y/x is exact.
276 ATF_TC_WITHOUT_HEAD(p2x_atan2);
277 ATF_TC_BODY(p2x_atan2, tc)
280 testall2(atan2, 1.0, 1.0, pi / 4, FE_INEXACT);
281 testall2(atan2, 1.0, -1.0, c3pi / 4, FE_INEXACT);
282 testall2(atan2, -1.0, 1.0, -pi / 4, FE_INEXACT);
283 testall2(atan2, -1.0, -1.0, -c3pi / 4, FE_INEXACT);
285 testall2_tol(atan2, sqrt2m1 * 2, 2.0, pi / 8, 1, FE_INEXACT);
286 testall2_tol(atan2, sqrt2m1 * 2, -2.0, c7pi / 8, 1, FE_INEXACT);
287 testall2_tol(atan2, -sqrt2m1 * 2, 2.0, -pi / 8, 1, FE_INEXACT);
288 testall2_tol(atan2, -sqrt2m1 * 2, -2.0, -c7pi / 8, 1, FE_INEXACT);
290 testall2_tol(atan2, sqrtl(3) * 0.5, 0.5, pio3, 1, FE_INEXACT);
291 testall2_tol(atan2, sqrtl(3) * 0.5, -0.5, pio3 * 2, 1, FE_INEXACT);
292 testall2_tol(atan2, -sqrtl(3) * 0.5, 0.5, -pio3, 1, FE_INEXACT);
293 testall2_tol(atan2, -sqrtl(3) * 0.5, -0.5, -pio3 * 2, 1, FE_INEXACT);
297 * Test inputs very close to 0.
299 ATF_TC_WITHOUT_HEAD(tiny);
300 ATF_TC_BODY(tiny, tc)
302 float tiny = 0x1.23456p-120f;
304 testall(asin, tiny, tiny, FE_INEXACT);
305 testall(acos, tiny, pi / 2, FE_INEXACT);
306 testall(atan, tiny, tiny, FE_INEXACT);
308 testall(asin, -tiny, -tiny, FE_INEXACT);
309 testall(acos, -tiny, pi / 2, FE_INEXACT);
310 testall(atan, -tiny, -tiny, FE_INEXACT);
312 /* Test inputs to atan2() that would cause y/x to underflow. */
313 test2(atan2f, 0x1.0p-100, 0x1.0p100, 0.0, FE_INEXACT | FE_UNDERFLOW);
314 test2(atan2, 0x1.0p-1000, 0x1.0p1000, 0.0, FE_INEXACT | FE_UNDERFLOW);
315 test2(atan2l, ldexpl(1.0, 100 - LDBL_MAX_EXP),
316 ldexpl(1.0, LDBL_MAX_EXP - 100), 0.0, FE_INEXACT | FE_UNDERFLOW);
317 test2(atan2f, -0x1.0p-100, 0x1.0p100, -0.0, FE_INEXACT | FE_UNDERFLOW);
318 test2(atan2, -0x1.0p-1000, 0x1.0p1000, -0.0, FE_INEXACT | FE_UNDERFLOW);
319 test2(atan2l, -ldexpl(1.0, 100 - LDBL_MAX_EXP),
320 ldexpl(1.0, LDBL_MAX_EXP - 100), -0.0, FE_INEXACT | FE_UNDERFLOW);
321 test2(atan2f, 0x1.0p-100, -0x1.0p100, (float)pi, FE_INEXACT);
322 test2(atan2, 0x1.0p-1000, -0x1.0p1000, (double)pi, FE_INEXACT);
323 test2(atan2l, ldexpl(1.0, 100 - LDBL_MAX_EXP),
324 -ldexpl(1.0, LDBL_MAX_EXP - 100), pi, FE_INEXACT);
325 test2(atan2f, -0x1.0p-100, -0x1.0p100, (float)-pi, FE_INEXACT);
326 test2(atan2, -0x1.0p-1000, -0x1.0p1000, (double)-pi, FE_INEXACT);
327 test2(atan2l, -ldexpl(1.0, 100 - LDBL_MAX_EXP),
328 -ldexpl(1.0, LDBL_MAX_EXP - 100), -pi, FE_INEXACT);
332 * Test very large inputs to atan().
334 ATF_TC_WITHOUT_HEAD(atan_huge);
335 ATF_TC_BODY(atan_huge, tc)
337 float huge = 0x1.23456p120;
339 testall(atan, huge, pi / 2, FE_INEXACT);
340 testall(atan, -huge, -pi / 2, FE_INEXACT);
342 /* Test inputs to atan2() that would cause y/x to overflow. */
343 test2(atan2f, 0x1.0p100, 0x1.0p-100, (float)pi / 2, FE_INEXACT);
344 test2(atan2, 0x1.0p1000, 0x1.0p-1000, (double)pi / 2, FE_INEXACT);
345 test2(atan2l, ldexpl(1.0, LDBL_MAX_EXP - 100),
346 ldexpl(1.0, 100 - LDBL_MAX_EXP), pi / 2, FE_INEXACT);
347 test2(atan2f, -0x1.0p100, 0x1.0p-100, (float)-pi / 2, FE_INEXACT);
348 test2(atan2, -0x1.0p1000, 0x1.0p-1000, (double)-pi / 2, FE_INEXACT);
349 test2(atan2l, -ldexpl(1.0, LDBL_MAX_EXP - 100),
350 ldexpl(1.0, 100 - LDBL_MAX_EXP), -pi / 2, FE_INEXACT);
352 test2(atan2f, 0x1.0p100, -0x1.0p-100, (float)pi / 2, FE_INEXACT);
353 test2(atan2, 0x1.0p1000, -0x1.0p-1000, (double)pi / 2, FE_INEXACT);
354 test2(atan2l, ldexpl(1.0, LDBL_MAX_EXP - 100),
355 -ldexpl(1.0, 100 - LDBL_MAX_EXP), pi / 2, FE_INEXACT);
356 test2(atan2f, -0x1.0p100, -0x1.0p-100, (float)-pi / 2, FE_INEXACT);
357 test2(atan2, -0x1.0p1000, -0x1.0p-1000, (double)-pi / 2, FE_INEXACT);
358 test2(atan2l, -ldexpl(1.0, LDBL_MAX_EXP - 100),
359 -ldexpl(1.0, 100 - LDBL_MAX_EXP), -pi / 2, FE_INEXACT);
363 * Test that sin(asin(x)) == x, and similarly for acos() and atan().
364 * You need to have a working sinl(), cosl(), and tanl() for these
371 return (sinl(asinf(x)));
378 return (sinl(asin(x)));
383 sinasinl(long double x)
386 return (sinl(asinl(x)));
394 return (cosl(acosf(x)));
401 return (cosl(acos(x)));
406 cosacosl(long double x)
409 return (cosl(acosl(x)));
417 return (tanl(atanf(x)));
424 return (tanl(atan(x)));
429 tanatanl(long double x)
432 return (tanl(atanl(x)));
436 ATF_TC_WITHOUT_HEAD(inverse);
437 ATF_TC_BODY(inverse, tc)
441 for (i = -1; i <= 1; i += 0x1.0p-12f) {
442 testall_tol(sinasin, i, i, 2, i == 0 ? 0 : FE_INEXACT);
443 /* The relative error for cosacos is very large near x=0. */
444 if (fabsf(i) > 0x1.0p-4f)
445 testall_tol(cosacos, i, i, 16, i == 1 ? 0 : FE_INEXACT);
446 testall_tol(tanatan, i, i, 2, i == 0 ? 0 : FE_INEXACT);
452 ATF_TP_ADD_TC(tp, special);
453 ATF_TP_ADD_TC(tp, special_atan2);
454 ATF_TP_ADD_TC(tp, accuracy);
455 ATF_TP_ADD_TC(tp, p2x_atan2);
456 ATF_TP_ADD_TC(tp, tiny);
457 ATF_TP_ADD_TC(tp, atan_huge);
458 ATF_TP_ADD_TC(tp, inverse);
460 return (atf_no_error());