xref: /freebsd/lib/msun/tests/fenv_test.c (revision a03411e84728e9b267056fd31c7d1d9d1dc1b01e)
1 /*-
2  * Copyright (c) 2004 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 the correctness and C99-compliance of various fenv.h features.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/wait.h>
33 #include <assert.h>
34 #include <err.h>
35 #include <fenv.h>
36 #include <float.h>
37 #include <libutil.h>
38 #include <math.h>
39 #include <signal.h>
40 #include <stdio.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "test-utils.h"
45 
46 #define	NEXCEPTS	(sizeof(std_excepts) / sizeof(std_excepts[0]))
47 
48 static const int std_excepts[] = {
49 	FE_INVALID,
50 	FE_DIVBYZERO,
51 	FE_OVERFLOW,
52 	FE_UNDERFLOW,
53 	FE_INEXACT,
54 };
55 
56 /* init_exceptsets() initializes this to the power set of std_excepts[] */
57 static int std_except_sets[1 << NEXCEPTS];
58 
59 #pragma STDC FENV_ACCESS ON
60 
61 /*
62  * Initialize std_except_sets[] to the power set of std_excepts[]
63  */
64 static __attribute__((constructor)) void
65 do_setup(void)
66 {
67 	unsigned i, j, sr;
68 
69 	/* Avoid double output after fork() */
70 	setvbuf(stdout, NULL, _IONBF, 0);
71 
72 	for (i = 0; i < 1 << NEXCEPTS; i++) {
73 		for (sr = i, j = 0; sr != 0; sr >>= 1, j++)
74 			std_except_sets[i] |= std_excepts[j] & ((~sr & 1) - 1);
75 	}
76 }
77 
78 /*
79  * Raise a floating-point exception without relying on the standard
80  * library routines, which we are trying to test.
81  *
82  * XXX We can't raise an {over,under}flow without also raising an
83  * inexact exception.
84  */
85 static void
86 raiseexcept(int excepts)
87 {
88 	volatile double d;
89 
90 	/*
91 	 * With a compiler that supports the FENV_ACCESS pragma
92 	 * properly, simple expressions like '0.0 / 0.0' should
93 	 * be sufficient to generate traps.  Unfortunately, we
94 	 * need to bring a volatile variable into the equation
95 	 * to prevent incorrect optimizations.
96 	 */
97 	if (excepts & FE_INVALID) {
98 		d = 0.0;
99 		d = 0.0 / d;
100 	}
101 	if (excepts & FE_DIVBYZERO) {
102 		d = 0.0;
103 		d = 1.0 / d;
104 	}
105 	if (excepts & FE_OVERFLOW) {
106 		d = DBL_MAX;
107 		d *= 2.0;
108 	}
109 	if (excepts & FE_UNDERFLOW) {
110 		d = DBL_MIN;
111 		d /= DBL_MAX;
112 	}
113 	if (excepts & FE_INEXACT) {
114 		d = DBL_MIN;
115 		d += 1.0;
116 	}
117 
118 	/*
119 	 * On the x86 (and some other architectures?) the FPU and
120 	 * integer units are decoupled.  We need to execute an FWAIT
121 	 * or a floating-point instruction to get synchronous exceptions.
122 	 */
123 	d = 1.0;
124 	d += 1.0;
125 }
126 
127 /*
128  * Determine the current rounding mode without relying on the fenv
129  * routines.  This function may raise an inexact exception.
130  */
131 static int
132 getround(void)
133 {
134 	volatile double d;
135 
136 	/*
137 	 * This test works just as well with 0.0 - 0.0, except on ia64
138 	 * where 0.0 - 0.0 gives the wrong sign when rounding downwards.
139 	 */
140 	d = 1.0;
141 	d -= 1.0;
142 	if (copysign(1.0, d) < 0.0)
143 		return (FE_DOWNWARD);
144 
145 	d = 1.0;
146 	if (d + (DBL_EPSILON * 3.0 / 4.0) == 1.0)
147 		return (FE_TOWARDZERO);
148 	if (d + (DBL_EPSILON * 1.0 / 4.0) > 1.0)
149 		return (FE_UPWARD);
150 
151 	return (FE_TONEAREST);
152 }
153 
154 static void
155 trap_handler(int sig)
156 {
157 
158 	ATF_CHECK_EQ(SIGFPE, sig);
159 	_exit(0);
160 }
161 
162 /*
163  * This tests checks the default FP environment, so it must be first.
164  * The memcmp() test below may be too much to ask for, since there
165  * could be multiple machine-specific default environments.
166  */
167 ATF_TC_WITHOUT_HEAD(dfl_env);
168 ATF_TC_BODY(dfl_env, tc)
169 {
170 #ifndef NO_STRICT_DFL_ENV
171 	fenv_t env;
172 
173 	fegetenv(&env);
174 	/* Print the default environment for debugging purposes. */
175 	hexdump(&env, sizeof(env), "current fenv ", HD_OMIT_CHARS);
176 	hexdump(FE_DFL_ENV, sizeof(env), "default fenv ", HD_OMIT_CHARS);
177 	CHECK_FP_EXCEPTIONS(0, FE_ALL_EXCEPT);
178 #ifdef __amd64__
179 	/*
180 	 * Compare the fields that the AMD [1] and Intel [2] specs say will be
181 	 * set once fnstenv returns.
182 	 *
183 	 * Not all amd64 capable processors implement the fnstenv instruction
184 	 * by zero'ing out the env.__x87.__other field (example: AMD Opteron
185 	 * 6308). The AMD64/x64 specs aren't explicit on what the
186 	 * env.__x87.__other field will contain after fnstenv is executed, so
187 	 * the values in env.__x87.__other could be filled with arbitrary
188 	 * data depending on how the CPU implements fnstenv.
189 	 *
190 	 * 1. http://support.amd.com/TechDocs/26569_APM_v5.pdf
191 	 * 2. http://www.intel.com/Assets/en_US/PDF/manual/253666.pdf
192 	 */
193 	ATF_CHECK(memcmp(&env.__mxcsr, &FE_DFL_ENV->__mxcsr,
194 	    sizeof(env.__mxcsr)) == 0);
195 	ATF_CHECK(memcmp(&env.__x87.__control, &FE_DFL_ENV->__x87.__control,
196 	    sizeof(env.__x87.__control)) == 0);
197 	ATF_CHECK(memcmp(&env.__x87.__status, &FE_DFL_ENV->__x87.__status,
198 	    sizeof(env.__x87.__status)) == 0);
199 	ATF_CHECK(memcmp(&env.__x87.__tag, &FE_DFL_ENV->__x87.__tag,
200 	    sizeof(env.__x87.__tag)) == 0);
201 #else
202 	ATF_CHECK_EQ(0, memcmp(&env, FE_DFL_ENV, sizeof(env)));
203 #endif
204 
205 #endif
206 	CHECK_FP_EXCEPTIONS(0, FE_ALL_EXCEPT);
207 }
208 
209 /*
210  * Test fetestexcept() and feclearexcept().
211  */
212 ATF_TC_WITHOUT_HEAD(fetestclearexcept);
213 ATF_TC_BODY(fetestclearexcept, tc)
214 {
215 	int excepts, i;
216 
217 	for (i = 0; i < 1 << NEXCEPTS; i++)
218 		ATF_CHECK_EQ(0, fetestexcept(std_except_sets[i]));
219 	for (i = 0; i < 1 << NEXCEPTS; i++) {
220 		excepts = std_except_sets[i];
221 
222 		/* FE_ALL_EXCEPT might be special-cased, as on i386. */
223 		raiseexcept(excepts);
224 		ATF_CHECK_EQ(excepts, fetestexcept(excepts));
225 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
226 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
227 
228 		raiseexcept(excepts);
229 		ATF_CHECK_EQ(excepts, fetestexcept(excepts));
230 		if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0) {
231 			excepts |= FE_INEXACT;
232 			ATF_CHECK_EQ(excepts, (fetestexcept(ALL_STD_EXCEPT) | FE_INEXACT));
233 		} else {
234 			ATF_CHECK_EQ(excepts, fetestexcept(ALL_STD_EXCEPT));
235 		}
236 		ATF_CHECK_EQ(0, feclearexcept(excepts));
237 		ATF_CHECK_EQ(0, fetestexcept(ALL_STD_EXCEPT));
238 	}
239 }
240 
241 /*
242  * Test fegetexceptflag() and fesetexceptflag().
243  *
244  * Prerequisites: fetestexcept(), feclearexcept()
245  */
246 ATF_TC_WITHOUT_HEAD(fegsetexceptflag);
247 ATF_TC_BODY(fegsetexceptflag, tc)
248 {
249 	fexcept_t flag;
250 	int excepts, i;
251 
252 	CHECK_FP_EXCEPTIONS(0, FE_ALL_EXCEPT);
253 	for (i = 0; i < 1 << NEXCEPTS; i++) {
254 		excepts = std_except_sets[i];
255 
256 		ATF_CHECK_EQ(0, fegetexceptflag(&flag, excepts));
257 		raiseexcept(ALL_STD_EXCEPT);
258 		ATF_CHECK_EQ(0, fesetexceptflag(&flag, excepts));
259 		ATF_CHECK_EQ((ALL_STD_EXCEPT ^ excepts), fetestexcept(ALL_STD_EXCEPT));
260 
261 		ATF_CHECK_EQ(0, fegetexceptflag(&flag, FE_ALL_EXCEPT));
262 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
263 		ATF_CHECK_EQ(0, fesetexceptflag(&flag, excepts));
264 		ATF_CHECK_EQ(0, fetestexcept(ALL_STD_EXCEPT));
265 		ATF_CHECK_EQ(0, fesetexceptflag(&flag, ALL_STD_EXCEPT ^ excepts));
266 		ATF_CHECK_EQ((ALL_STD_EXCEPT ^ excepts), fetestexcept(ALL_STD_EXCEPT));
267 
268 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
269 	}
270 }
271 
272 /*
273  * Test feraiseexcept().
274  *
275  * Prerequisites: fetestexcept(), feclearexcept()
276  */
277 ATF_TC_WITHOUT_HEAD(feraiseexcept);
278 ATF_TC_BODY(feraiseexcept, tc)
279 {
280 	int excepts, i;
281 
282 	for (i = 0; i < 1 << NEXCEPTS; i++) {
283 		excepts = std_except_sets[i];
284 
285 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
286 		ATF_CHECK_EQ(0, feraiseexcept(excepts));
287 		if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0) {
288 			excepts |= FE_INEXACT;
289 			ATF_CHECK_EQ(excepts, (fetestexcept(ALL_STD_EXCEPT) | FE_INEXACT));
290 		} else {
291 			ATF_CHECK_EQ(excepts, fetestexcept(ALL_STD_EXCEPT));
292 		}
293 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
294 	}
295 	ATF_CHECK_EQ(0, feraiseexcept(FE_INVALID | FE_DIVBYZERO));
296 	ATF_CHECK_EQ((FE_INVALID | FE_DIVBYZERO), fetestexcept(ALL_STD_EXCEPT));
297 	ATF_CHECK_EQ(0, feraiseexcept(FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT));
298 	ATF_CHECK_EQ(ALL_STD_EXCEPT, fetestexcept(ALL_STD_EXCEPT));
299 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
300 }
301 
302 /*
303  * Test fegetround() and fesetround().
304  */
305 ATF_TC_WITHOUT_HEAD(fegsetround);
306 ATF_TC_BODY(fegsetround, tc)
307 {
308 
309 	ATF_CHECK_EQ(FE_TONEAREST, fegetround());
310 	ATF_CHECK_EQ(FE_TONEAREST, getround());
311 	ATF_CHECK_EQ(1, FLT_ROUNDS);
312 
313 	ATF_CHECK_EQ(0, fesetround(FE_DOWNWARD));
314 	ATF_CHECK_EQ(FE_DOWNWARD, fegetround());
315 	ATF_CHECK_EQ(FE_DOWNWARD, getround());
316 	ATF_CHECK_EQ(3, FLT_ROUNDS);
317 
318 	ATF_CHECK_EQ(0, fesetround(FE_UPWARD));
319 	ATF_CHECK_EQ(FE_UPWARD, getround());
320 	ATF_CHECK_EQ(FE_UPWARD, fegetround());
321 	ATF_CHECK_EQ(2, FLT_ROUNDS);
322 
323 	ATF_CHECK_EQ(0, fesetround(FE_TOWARDZERO));
324 	ATF_CHECK_EQ(FE_TOWARDZERO, getround());
325 	ATF_CHECK_EQ(FE_TOWARDZERO, fegetround());
326 	ATF_CHECK_EQ(0, FLT_ROUNDS);
327 
328 	ATF_CHECK_EQ(0, fesetround(FE_TONEAREST));
329 	ATF_CHECK_EQ(FE_TONEAREST, getround());
330 	ATF_CHECK_EQ(1, FLT_ROUNDS);
331 
332 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
333 }
334 
335 /*
336  * Test fegetenv() and fesetenv().
337  *
338  * Prerequisites: fetestexcept(), feclearexcept(), fegetround(), fesetround()
339  */
340 ATF_TC_WITHOUT_HEAD(fegsetenv);
341 ATF_TC_BODY(fegsetenv, tc)
342 {
343 	fenv_t env1, env2;
344 	int excepts, i;
345 
346 	for (i = 0; i < 1 << NEXCEPTS; i++) {
347 		excepts = std_except_sets[i];
348 
349 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
350 		ATF_CHECK_EQ(FE_TONEAREST, fegetround());
351 		ATF_CHECK_EQ(0, fegetenv(&env1));
352 
353 		/*
354 		 * fe[gs]etenv() should be able to save and restore
355 		 * exception flags without the spurious inexact
356 		 * exceptions that afflict raiseexcept().
357 		 */
358 		raiseexcept(excepts);
359 		if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0 &&
360 		    (excepts & FE_INEXACT) == 0)
361 			ATF_CHECK_EQ(0, feclearexcept(FE_INEXACT));
362 
363 		fesetround(FE_DOWNWARD);
364 		ATF_CHECK_EQ(0, fegetenv(&env2));
365 		ATF_CHECK_EQ(0, fesetenv(&env1));
366 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
367 		ATF_CHECK_EQ(FE_TONEAREST, fegetround());
368 
369 		ATF_CHECK_EQ(0, fesetenv(&env2));
370 
371 		/*
372 		 * Some platforms like powerpc may set extra exception bits. Since
373 		 * only standard exceptions are tested, mask against ALL_STD_EXCEPT
374 		 */
375 		ATF_CHECK_EQ(excepts, (fetestexcept(FE_ALL_EXCEPT) & ALL_STD_EXCEPT));
376 
377 		ATF_CHECK_EQ(FE_DOWNWARD, fegetround());
378 		ATF_CHECK_EQ(0, fesetenv(&env1));
379 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
380 		ATF_CHECK_EQ(FE_TONEAREST, fegetround());
381 	}
382 }
383 
384 /*
385  * Test fegetexcept(), fedisableexcept(), and feenableexcept().
386  *
387  * Prerequisites: fetestexcept(), feraiseexcept()
388  */
389 ATF_TC_WITHOUT_HEAD(masking);
390 ATF_TC_BODY(masking, tc)
391 {
392 	struct sigaction act;
393 	int except, pass, raise, status;
394 	unsigned i;
395 
396 	ATF_REQUIRE_EQ(0, (fegetexcept() & ALL_STD_EXCEPT));
397 
398 	/*
399 	 * Some CPUs, e.g. AArch64 QEMU does not support trapping on FP
400 	 * exceptions. In that case the trap enable bits are all RAZ/WI, so
401 	 * writing to those bits will be ignored and the next read will
402 	 * return all zeroes for those bits. Skip the test if no floating
403 	 * point exceptions are supported and mark it XFAIL if some are missing.
404 	 */
405 	ATF_REQUIRE_EQ(0, (feenableexcept(FE_ALL_EXCEPT)));
406 	except = fegetexcept();
407 	if (except == 0) {
408 		atf_tc_skip("CPU does not support trapping on floating point "
409 		    "exceptions.");
410 	} else if ((except & ALL_STD_EXCEPT) != ALL_STD_EXCEPT) {
411 		atf_tc_expect_fail("Not all floating point exceptions can be "
412 		    "set to trap: %#x vs %#x", except, ALL_STD_EXCEPT);
413 	}
414 	fedisableexcept(FE_ALL_EXCEPT);
415 
416 
417 	ATF_CHECK_EQ(0, (feenableexcept(FE_INVALID|FE_OVERFLOW) & ALL_STD_EXCEPT));
418 	ATF_CHECK_EQ((FE_INVALID | FE_OVERFLOW), (feenableexcept(FE_UNDERFLOW) & ALL_STD_EXCEPT));
419 	ATF_CHECK_EQ((FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW), (fedisableexcept(FE_OVERFLOW) & ALL_STD_EXCEPT));
420 	ATF_CHECK_EQ((FE_INVALID | FE_UNDERFLOW), (fegetexcept() & ALL_STD_EXCEPT));
421 	ATF_CHECK_EQ((FE_INVALID | FE_UNDERFLOW), (fedisableexcept(FE_ALL_EXCEPT) & ALL_STD_EXCEPT));
422 	ATF_CHECK_EQ(0, (fegetexcept() & ALL_STD_EXCEPT));
423 
424 	sigemptyset(&act.sa_mask);
425 	act.sa_flags = 0;
426 	act.sa_handler = trap_handler;
427 	for (pass = 0; pass < 2; pass++) {
428 		for (i = 0; i < NEXCEPTS; i++) {
429 			except = std_excepts[i];
430 			/* over/underflow may also raise inexact */
431 			if (except == FE_INEXACT)
432 				raise = FE_DIVBYZERO | FE_INVALID;
433 			else
434 				raise = ALL_STD_EXCEPT ^ except;
435 
436 			/*
437 			 * We need to fork a child process because
438 			 * there isn't a portable way to recover from
439 			 * a floating-point exception.
440 			 */
441 			switch(fork()) {
442 			case 0:		/* child */
443 				ATF_CHECK_EQ(0, (fegetexcept() & ALL_STD_EXCEPT));
444 				ATF_REQUIRE_EQ(0, (feenableexcept(except) & ALL_STD_EXCEPT));
445 				ATF_CHECK_EQ(except, fegetexcept());
446 				raiseexcept(raise);
447 				ATF_CHECK_EQ(0, feraiseexcept(raise));
448 				ATF_CHECK_EQ(raise, fetestexcept(ALL_STD_EXCEPT));
449 
450 				ATF_CHECK_EQ(0, sigaction(SIGFPE, &act, NULL));
451 				switch (pass) {
452 				case 0:
453 					raiseexcept(except);
454 				case 1:
455 					feraiseexcept(except);
456 				default:
457 					ATF_REQUIRE(0);
458 				}
459 				ATF_REQUIRE(0);
460 			default:	/* parent */
461 				ATF_REQUIRE(wait(&status) > 0);
462 				/*
463 				 * Avoid assert() here so that it's possible
464 				 * to examine a failed child's core dump.
465 				 */
466 				if (!WIFEXITED(status))
467 					errx(1, "child aborted\n");
468 				ATF_CHECK_EQ(0, WEXITSTATUS(status));
469 				break;
470 			case -1:	/* error */
471 				ATF_REQUIRE(0);
472 			}
473 		}
474 	}
475 	ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
476 }
477 
478 /*
479  * Test feholdexcept() and feupdateenv().
480  *
481  * Prerequisites: fetestexcept(), fegetround(), fesetround(),
482  *	fedisableexcept(), feenableexcept()
483  */
484 ATF_TC_WITHOUT_HEAD(feholdupdate);
485 ATF_TC_BODY(feholdupdate, tc)
486 {
487 	fenv_t env;
488 
489 	struct sigaction act;
490 	int except, pass, status, raise;
491 	unsigned i;
492 
493 	sigemptyset(&act.sa_mask);
494 	act.sa_flags = 0;
495 	act.sa_handler = trap_handler;
496 	for (pass = 0; pass < 2; pass++) {
497 		for (i = 0; i < NEXCEPTS; i++) {
498 			except = std_excepts[i];
499 			/* over/underflow may also raise inexact */
500 			if (except == FE_INEXACT)
501 				raise = FE_DIVBYZERO | FE_INVALID;
502 			else
503 				raise = ALL_STD_EXCEPT ^ except;
504 
505 			/*
506 			 * We need to fork a child process because
507 			 * there isn't a portable way to recover from
508 			 * a floating-point exception.
509 			 */
510 			switch(fork()) {
511 			case 0:		/* child */
512 				/*
513 				 * We don't want to cause a fatal exception in
514 				 * the child until the second pass, so we can
515 				 * check other properties of feupdateenv().
516 				 */
517 				if (pass == 1)
518 					ATF_REQUIRE_EQ(0, feenableexcept(except) & ALL_STD_EXCEPT);
519 				raiseexcept(raise);
520 				ATF_CHECK_EQ(0, fesetround(FE_DOWNWARD));
521 				ATF_CHECK_EQ(0, feholdexcept(&env));
522 				ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
523 				raiseexcept(except);
524 				ATF_CHECK_EQ(0, fesetround(FE_UPWARD));
525 
526 				if (pass == 1)
527 					ATF_CHECK_EQ(0, sigaction(SIGFPE, &act, NULL));
528 				ATF_CHECK_EQ(0, feupdateenv(&env));
529 				ATF_CHECK_EQ(FE_DOWNWARD, fegetround());
530 				ATF_CHECK_EQ((except | raise), fetestexcept(ALL_STD_EXCEPT));
531 
532 				ATF_CHECK_EQ(0, pass);
533 				_exit(0);
534 			default:	/* parent */
535 				ATF_REQUIRE(wait(&status) > 0);
536 				/*
537 				 * Avoid assert() here so that it's possible
538 				 * to examine a failed child's core dump.
539 				 */
540 				if (!WIFEXITED(status))
541 					errx(1, "child aborted\n");
542 				ATF_CHECK_EQ(0, WEXITSTATUS(status));
543 				break;
544 			case -1:	/* error */
545 				ATF_REQUIRE(0);
546 			}
547 		}
548 	}
549 	ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
550 }
551 
552 ATF_TP_ADD_TCS(tp)
553 {
554 	ATF_TP_ADD_TC(tp, dfl_env);
555 	ATF_TP_ADD_TC(tp, fetestclearexcept);
556 	ATF_TP_ADD_TC(tp, fegsetexceptflag);
557 	ATF_TP_ADD_TC(tp, feraiseexcept);
558 	ATF_TP_ADD_TC(tp, fegsetround);
559 	ATF_TP_ADD_TC(tp, fegsetenv);
560 	ATF_TP_ADD_TC(tp, masking);
561 	ATF_TP_ADD_TC(tp, feholdupdate);
562 
563 	return (atf_no_error());
564 }
565