xref: /freebsd/lib/msun/tests/fenv_test.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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/cdefs.h>
32 #include <sys/types.h>
33 #include <sys/wait.h>
34 #include <assert.h>
35 #include <err.h>
36 #include <fenv.h>
37 #include <float.h>
38 #include <libutil.h>
39 #include <math.h>
40 #include <signal.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 #include "test-utils.h"
46 
47 #define	NEXCEPTS	(sizeof(std_excepts) / sizeof(std_excepts[0]))
48 
49 static const int std_excepts[] = {
50 	FE_INVALID,
51 	FE_DIVBYZERO,
52 	FE_OVERFLOW,
53 	FE_UNDERFLOW,
54 	FE_INEXACT,
55 };
56 
57 /* init_exceptsets() initializes this to the power set of std_excepts[] */
58 static int std_except_sets[1 << NEXCEPTS];
59 
60 #pragma STDC FENV_ACCESS ON
61 
62 /*
63  * Initialize std_except_sets[] to the power set of std_excepts[]
64  */
65 static __attribute__((constructor)) void
66 do_setup(void)
67 {
68 	unsigned i, j, sr;
69 
70 	/* Avoid double output after fork() */
71 	setvbuf(stdout, NULL, _IONBF, 0);
72 
73 	for (i = 0; i < 1 << NEXCEPTS; i++) {
74 		for (sr = i, j = 0; sr != 0; sr >>= 1, j++)
75 			std_except_sets[i] |= std_excepts[j] & ((~sr & 1) - 1);
76 	}
77 }
78 
79 /*
80  * Raise a floating-point exception without relying on the standard
81  * library routines, which we are trying to test.
82  *
83  * XXX We can't raise an {over,under}flow without also raising an
84  * inexact exception.
85  */
86 static void
87 raiseexcept(int excepts)
88 {
89 	volatile double d;
90 
91 	/*
92 	 * With a compiler that supports the FENV_ACCESS pragma
93 	 * properly, simple expressions like '0.0 / 0.0' should
94 	 * be sufficient to generate traps.  Unfortunately, we
95 	 * need to bring a volatile variable into the equation
96 	 * to prevent incorrect optimizations.
97 	 */
98 	if (excepts & FE_INVALID) {
99 		d = 0.0;
100 		d = 0.0 / d;
101 	}
102 	if (excepts & FE_DIVBYZERO) {
103 		d = 0.0;
104 		d = 1.0 / d;
105 	}
106 	if (excepts & FE_OVERFLOW) {
107 		d = DBL_MAX;
108 		d *= 2.0;
109 	}
110 	if (excepts & FE_UNDERFLOW) {
111 		d = DBL_MIN;
112 		d /= DBL_MAX;
113 	}
114 	if (excepts & FE_INEXACT) {
115 		d = DBL_MIN;
116 		d += 1.0;
117 	}
118 
119 	/*
120 	 * On the x86 (and some other architectures?) the FPU and
121 	 * integer units are decoupled.  We need to execute an FWAIT
122 	 * or a floating-point instruction to get synchronous exceptions.
123 	 */
124 	d = 1.0;
125 	d += 1.0;
126 }
127 
128 /*
129  * Determine the current rounding mode without relying on the fenv
130  * routines.  This function may raise an inexact exception.
131  */
132 static int
133 getround(void)
134 {
135 	volatile double d;
136 
137 	/*
138 	 * This test works just as well with 0.0 - 0.0, except on ia64
139 	 * where 0.0 - 0.0 gives the wrong sign when rounding downwards.
140 	 */
141 	d = 1.0;
142 	d -= 1.0;
143 	if (copysign(1.0, d) < 0.0)
144 		return (FE_DOWNWARD);
145 
146 	d = 1.0;
147 	if (d + (DBL_EPSILON * 3.0 / 4.0) == 1.0)
148 		return (FE_TOWARDZERO);
149 	if (d + (DBL_EPSILON * 1.0 / 4.0) > 1.0)
150 		return (FE_UPWARD);
151 
152 	return (FE_TONEAREST);
153 }
154 
155 static void
156 trap_handler(int sig)
157 {
158 
159 	ATF_CHECK_EQ(SIGFPE, sig);
160 	_exit(0);
161 }
162 
163 /*
164  * This tests checks the default FP environment, so it must be first.
165  * The memcmp() test below may be too much to ask for, since there
166  * could be multiple machine-specific default environments.
167  */
168 ATF_TC_WITHOUT_HEAD(dfl_env);
169 ATF_TC_BODY(dfl_env, tc)
170 {
171 #ifndef NO_STRICT_DFL_ENV
172 	fenv_t env;
173 
174 	fegetenv(&env);
175 	/* Print the default environment for debugging purposes. */
176 	hexdump(&env, sizeof(env), "current fenv ", HD_OMIT_CHARS);
177 	hexdump(FE_DFL_ENV, sizeof(env), "default fenv ", HD_OMIT_CHARS);
178 	CHECK_FP_EXCEPTIONS(0, FE_ALL_EXCEPT);
179 #ifdef __amd64__
180 	/*
181 	 * Compare the fields that the AMD [1] and Intel [2] specs say will be
182 	 * set once fnstenv returns.
183 	 *
184 	 * Not all amd64 capable processors implement the fnstenv instruction
185 	 * by zero'ing out the env.__x87.__other field (example: AMD Opteron
186 	 * 6308). The AMD64/x64 specs aren't explicit on what the
187 	 * env.__x87.__other field will contain after fnstenv is executed, so
188 	 * the values in env.__x87.__other could be filled with arbitrary
189 	 * data depending on how the CPU implements fnstenv.
190 	 *
191 	 * 1. http://support.amd.com/TechDocs/26569_APM_v5.pdf
192 	 * 2. http://www.intel.com/Assets/en_US/PDF/manual/253666.pdf
193 	 */
194 	ATF_CHECK(memcmp(&env.__mxcsr, &FE_DFL_ENV->__mxcsr,
195 	    sizeof(env.__mxcsr)) == 0);
196 	ATF_CHECK(memcmp(&env.__x87.__control, &FE_DFL_ENV->__x87.__control,
197 	    sizeof(env.__x87.__control)) == 0);
198 	ATF_CHECK(memcmp(&env.__x87.__status, &FE_DFL_ENV->__x87.__status,
199 	    sizeof(env.__x87.__status)) == 0);
200 	ATF_CHECK(memcmp(&env.__x87.__tag, &FE_DFL_ENV->__x87.__tag,
201 	    sizeof(env.__x87.__tag)) == 0);
202 #else
203 	ATF_CHECK_EQ(0, memcmp(&env, FE_DFL_ENV, sizeof(env)));
204 #endif
205 
206 #endif
207 	CHECK_FP_EXCEPTIONS(0, FE_ALL_EXCEPT);
208 }
209 
210 /*
211  * Test fetestexcept() and feclearexcept().
212  */
213 ATF_TC_WITHOUT_HEAD(fetestclearexcept);
214 ATF_TC_BODY(fetestclearexcept, tc)
215 {
216 	int excepts, i;
217 
218 	for (i = 0; i < 1 << NEXCEPTS; i++)
219 		ATF_CHECK_EQ(0, fetestexcept(std_except_sets[i]));
220 	for (i = 0; i < 1 << NEXCEPTS; i++) {
221 		excepts = std_except_sets[i];
222 
223 		/* FE_ALL_EXCEPT might be special-cased, as on i386. */
224 		raiseexcept(excepts);
225 		ATF_CHECK_EQ(excepts, fetestexcept(excepts));
226 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
227 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
228 
229 		raiseexcept(excepts);
230 		ATF_CHECK_EQ(excepts, fetestexcept(excepts));
231 		if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0) {
232 			excepts |= FE_INEXACT;
233 			ATF_CHECK_EQ(excepts, (fetestexcept(ALL_STD_EXCEPT) | FE_INEXACT));
234 		} else {
235 			ATF_CHECK_EQ(excepts, fetestexcept(ALL_STD_EXCEPT));
236 		}
237 		ATF_CHECK_EQ(0, feclearexcept(excepts));
238 		ATF_CHECK_EQ(0, fetestexcept(ALL_STD_EXCEPT));
239 	}
240 }
241 
242 /*
243  * Test fegetexceptflag() and fesetexceptflag().
244  *
245  * Prerequisites: fetestexcept(), feclearexcept()
246  */
247 ATF_TC_WITHOUT_HEAD(fegsetexceptflag);
248 ATF_TC_BODY(fegsetexceptflag, tc)
249 {
250 	fexcept_t flag;
251 	int excepts, i;
252 
253 	CHECK_FP_EXCEPTIONS(0, FE_ALL_EXCEPT);
254 	for (i = 0; i < 1 << NEXCEPTS; i++) {
255 		excepts = std_except_sets[i];
256 
257 		ATF_CHECK_EQ(0, fegetexceptflag(&flag, excepts));
258 		raiseexcept(ALL_STD_EXCEPT);
259 		ATF_CHECK_EQ(0, fesetexceptflag(&flag, excepts));
260 		ATF_CHECK_EQ((ALL_STD_EXCEPT ^ excepts), fetestexcept(ALL_STD_EXCEPT));
261 
262 		ATF_CHECK_EQ(0, fegetexceptflag(&flag, FE_ALL_EXCEPT));
263 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
264 		ATF_CHECK_EQ(0, fesetexceptflag(&flag, excepts));
265 		ATF_CHECK_EQ(0, fetestexcept(ALL_STD_EXCEPT));
266 		ATF_CHECK_EQ(0, fesetexceptflag(&flag, ALL_STD_EXCEPT ^ excepts));
267 		ATF_CHECK_EQ((ALL_STD_EXCEPT ^ excepts), fetestexcept(ALL_STD_EXCEPT));
268 
269 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
270 	}
271 }
272 
273 /*
274  * Test feraiseexcept().
275  *
276  * Prerequisites: fetestexcept(), feclearexcept()
277  */
278 ATF_TC_WITHOUT_HEAD(feraiseexcept);
279 ATF_TC_BODY(feraiseexcept, tc)
280 {
281 	int excepts, i;
282 
283 	for (i = 0; i < 1 << NEXCEPTS; i++) {
284 		excepts = std_except_sets[i];
285 
286 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
287 		ATF_CHECK_EQ(0, feraiseexcept(excepts));
288 		if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0) {
289 			excepts |= FE_INEXACT;
290 			ATF_CHECK_EQ(excepts, (fetestexcept(ALL_STD_EXCEPT) | FE_INEXACT));
291 		} else {
292 			ATF_CHECK_EQ(excepts, fetestexcept(ALL_STD_EXCEPT));
293 		}
294 		ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
295 	}
296 	ATF_CHECK_EQ(0, feraiseexcept(FE_INVALID | FE_DIVBYZERO));
297 	ATF_CHECK_EQ((FE_INVALID | FE_DIVBYZERO), fetestexcept(ALL_STD_EXCEPT));
298 	ATF_CHECK_EQ(0, feraiseexcept(FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT));
299 	ATF_CHECK_EQ(ALL_STD_EXCEPT, fetestexcept(ALL_STD_EXCEPT));
300 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
301 }
302 
303 /*
304  * Test fegetround() and fesetround().
305  */
306 ATF_TC_WITHOUT_HEAD(fegsetround);
307 ATF_TC_BODY(fegsetround, tc)
308 {
309 
310 	ATF_CHECK_EQ(FE_TONEAREST, fegetround());
311 	ATF_CHECK_EQ(FE_TONEAREST, getround());
312 	ATF_CHECK_EQ(1, FLT_ROUNDS);
313 
314 	ATF_CHECK_EQ(0, fesetround(FE_DOWNWARD));
315 	ATF_CHECK_EQ(FE_DOWNWARD, fegetround());
316 	ATF_CHECK_EQ(FE_DOWNWARD, getround());
317 	ATF_CHECK_EQ(3, FLT_ROUNDS);
318 
319 	ATF_CHECK_EQ(0, fesetround(FE_UPWARD));
320 	ATF_CHECK_EQ(FE_UPWARD, getround());
321 	ATF_CHECK_EQ(FE_UPWARD, fegetround());
322 	ATF_CHECK_EQ(2, FLT_ROUNDS);
323 
324 	ATF_CHECK_EQ(0, fesetround(FE_TOWARDZERO));
325 	ATF_CHECK_EQ(FE_TOWARDZERO, getround());
326 	ATF_CHECK_EQ(FE_TOWARDZERO, fegetround());
327 	ATF_CHECK_EQ(0, FLT_ROUNDS);
328 
329 	ATF_CHECK_EQ(0, fesetround(FE_TONEAREST));
330 	ATF_CHECK_EQ(FE_TONEAREST, getround());
331 	ATF_CHECK_EQ(1, FLT_ROUNDS);
332 
333 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
334 }
335 
336 /*
337  * Test fegetenv() and fesetenv().
338  *
339  * Prerequisites: fetestexcept(), feclearexcept(), fegetround(), fesetround()
340  */
341 ATF_TC_WITHOUT_HEAD(fegsetenv);
342 ATF_TC_BODY(fegsetenv, tc)
343 {
344 	fenv_t env1, env2;
345 	int excepts, i;
346 
347 	for (i = 0; i < 1 << NEXCEPTS; i++) {
348 		excepts = std_except_sets[i];
349 
350 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
351 		ATF_CHECK_EQ(FE_TONEAREST, fegetround());
352 		ATF_CHECK_EQ(0, fegetenv(&env1));
353 
354 		/*
355 		 * fe[gs]etenv() should be able to save and restore
356 		 * exception flags without the spurious inexact
357 		 * exceptions that afflict raiseexcept().
358 		 */
359 		raiseexcept(excepts);
360 		if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0 &&
361 		    (excepts & FE_INEXACT) == 0)
362 			ATF_CHECK_EQ(0, feclearexcept(FE_INEXACT));
363 
364 		fesetround(FE_DOWNWARD);
365 		ATF_CHECK_EQ(0, fegetenv(&env2));
366 		ATF_CHECK_EQ(0, fesetenv(&env1));
367 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
368 		ATF_CHECK_EQ(FE_TONEAREST, fegetround());
369 
370 		ATF_CHECK_EQ(0, fesetenv(&env2));
371 
372 		/*
373 		 * Some platforms like powerpc may set extra exception bits. Since
374 		 * only standard exceptions are tested, mask against ALL_STD_EXCEPT
375 		 */
376 		ATF_CHECK_EQ(excepts, (fetestexcept(FE_ALL_EXCEPT) & ALL_STD_EXCEPT));
377 
378 		ATF_CHECK_EQ(FE_DOWNWARD, fegetround());
379 		ATF_CHECK_EQ(0, fesetenv(&env1));
380 		ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
381 		ATF_CHECK_EQ(FE_TONEAREST, fegetround());
382 	}
383 }
384 
385 /*
386  * Test fegetexcept(), fedisableexcept(), and feenableexcept().
387  *
388  * Prerequisites: fetestexcept(), feraiseexcept()
389  */
390 ATF_TC_WITHOUT_HEAD(masking);
391 ATF_TC_BODY(masking, tc)
392 {
393 	struct sigaction act;
394 	int except, pass, raise, status;
395 	unsigned i;
396 
397 	ATF_REQUIRE_EQ(0, (fegetexcept() & ALL_STD_EXCEPT));
398 
399 	/*
400 	 * Some CPUs, e.g. AArch64 QEMU does not support trapping on FP
401 	 * exceptions. In that case the trap enable bits are all RAZ/WI, so
402 	 * writing to those bits will be ignored and the next read will
403 	 * return all zeroes for those bits. Skip the test if no floating
404 	 * point exceptions are supported and mark it XFAIL if some are missing.
405 	 */
406 	ATF_REQUIRE_EQ(0, (feenableexcept(FE_ALL_EXCEPT)));
407 	except = fegetexcept();
408 	if (except == 0) {
409 		atf_tc_skip("CPU does not support trapping on floating point "
410 		    "exceptions.");
411 	} else if ((except & ALL_STD_EXCEPT) != ALL_STD_EXCEPT) {
412 		atf_tc_expect_fail("Not all floating point exceptions can be "
413 		    "set to trap: %#x vs %#x", except, ALL_STD_EXCEPT);
414 	}
415 	fedisableexcept(FE_ALL_EXCEPT);
416 
417 
418 	ATF_CHECK_EQ(0, (feenableexcept(FE_INVALID|FE_OVERFLOW) & ALL_STD_EXCEPT));
419 	ATF_CHECK_EQ((FE_INVALID | FE_OVERFLOW), (feenableexcept(FE_UNDERFLOW) & ALL_STD_EXCEPT));
420 	ATF_CHECK_EQ((FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW), (fedisableexcept(FE_OVERFLOW) & ALL_STD_EXCEPT));
421 	ATF_CHECK_EQ((FE_INVALID | FE_UNDERFLOW), (fegetexcept() & ALL_STD_EXCEPT));
422 	ATF_CHECK_EQ((FE_INVALID | FE_UNDERFLOW), (fedisableexcept(FE_ALL_EXCEPT) & ALL_STD_EXCEPT));
423 	ATF_CHECK_EQ(0, (fegetexcept() & ALL_STD_EXCEPT));
424 
425 	sigemptyset(&act.sa_mask);
426 	act.sa_flags = 0;
427 	act.sa_handler = trap_handler;
428 	for (pass = 0; pass < 2; pass++) {
429 		for (i = 0; i < NEXCEPTS; i++) {
430 			except = std_excepts[i];
431 			/* over/underflow may also raise inexact */
432 			if (except == FE_INEXACT)
433 				raise = FE_DIVBYZERO | FE_INVALID;
434 			else
435 				raise = ALL_STD_EXCEPT ^ except;
436 
437 			/*
438 			 * We need to fork a child process because
439 			 * there isn't a portable way to recover from
440 			 * a floating-point exception.
441 			 */
442 			switch(fork()) {
443 			case 0:		/* child */
444 				ATF_CHECK_EQ(0, (fegetexcept() & ALL_STD_EXCEPT));
445 				ATF_REQUIRE_EQ(0, (feenableexcept(except) & ALL_STD_EXCEPT));
446 				ATF_CHECK_EQ(except, fegetexcept());
447 				raiseexcept(raise);
448 				ATF_CHECK_EQ(0, feraiseexcept(raise));
449 				ATF_CHECK_EQ(raise, fetestexcept(ALL_STD_EXCEPT));
450 
451 				ATF_CHECK_EQ(0, sigaction(SIGFPE, &act, NULL));
452 				switch (pass) {
453 				case 0:
454 					raiseexcept(except);
455 				case 1:
456 					feraiseexcept(except);
457 				default:
458 					ATF_REQUIRE(0);
459 				}
460 				ATF_REQUIRE(0);
461 			default:	/* parent */
462 				ATF_REQUIRE(wait(&status) > 0);
463 				/*
464 				 * Avoid assert() here so that it's possible
465 				 * to examine a failed child's core dump.
466 				 */
467 				if (!WIFEXITED(status))
468 					errx(1, "child aborted\n");
469 				ATF_CHECK_EQ(0, WEXITSTATUS(status));
470 				break;
471 			case -1:	/* error */
472 				ATF_REQUIRE(0);
473 			}
474 		}
475 	}
476 	ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
477 }
478 
479 /*
480  * Test feholdexcept() and feupdateenv().
481  *
482  * Prerequisites: fetestexcept(), fegetround(), fesetround(),
483  *	fedisableexcept(), feenableexcept()
484  */
485 ATF_TC_WITHOUT_HEAD(feholdupdate);
486 ATF_TC_BODY(feholdupdate, tc)
487 {
488 	fenv_t env;
489 
490 	struct sigaction act;
491 	int except, pass, status, raise;
492 	unsigned i;
493 
494 	sigemptyset(&act.sa_mask);
495 	act.sa_flags = 0;
496 	act.sa_handler = trap_handler;
497 	for (pass = 0; pass < 2; pass++) {
498 		for (i = 0; i < NEXCEPTS; i++) {
499 			except = std_excepts[i];
500 			/* over/underflow may also raise inexact */
501 			if (except == FE_INEXACT)
502 				raise = FE_DIVBYZERO | FE_INVALID;
503 			else
504 				raise = ALL_STD_EXCEPT ^ except;
505 
506 			/*
507 			 * We need to fork a child process because
508 			 * there isn't a portable way to recover from
509 			 * a floating-point exception.
510 			 */
511 			switch(fork()) {
512 			case 0:		/* child */
513 				/*
514 				 * We don't want to cause a fatal exception in
515 				 * the child until the second pass, so we can
516 				 * check other properties of feupdateenv().
517 				 */
518 				if (pass == 1)
519 					ATF_REQUIRE_EQ(0, feenableexcept(except) & ALL_STD_EXCEPT);
520 				raiseexcept(raise);
521 				ATF_CHECK_EQ(0, fesetround(FE_DOWNWARD));
522 				ATF_CHECK_EQ(0, feholdexcept(&env));
523 				ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
524 				raiseexcept(except);
525 				ATF_CHECK_EQ(0, fesetround(FE_UPWARD));
526 
527 				if (pass == 1)
528 					ATF_CHECK_EQ(0, sigaction(SIGFPE, &act, NULL));
529 				ATF_CHECK_EQ(0, feupdateenv(&env));
530 				ATF_CHECK_EQ(FE_DOWNWARD, fegetround());
531 				ATF_CHECK_EQ((except | raise), fetestexcept(ALL_STD_EXCEPT));
532 
533 				ATF_CHECK_EQ(0, pass);
534 				_exit(0);
535 			default:	/* parent */
536 				ATF_REQUIRE(wait(&status) > 0);
537 				/*
538 				 * Avoid assert() here so that it's possible
539 				 * to examine a failed child's core dump.
540 				 */
541 				if (!WIFEXITED(status))
542 					errx(1, "child aborted\n");
543 				ATF_CHECK_EQ(0, WEXITSTATUS(status));
544 				break;
545 			case -1:	/* error */
546 				ATF_REQUIRE(0);
547 			}
548 		}
549 	}
550 	ATF_CHECK_EQ(0, fetestexcept(FE_ALL_EXCEPT));
551 }
552 
553 ATF_TP_ADD_TCS(tp)
554 {
555 	ATF_TP_ADD_TC(tp, dfl_env);
556 	ATF_TP_ADD_TC(tp, fetestclearexcept);
557 	ATF_TP_ADD_TC(tp, fegsetexceptflag);
558 	ATF_TP_ADD_TC(tp, feraiseexcept);
559 	ATF_TP_ADD_TC(tp, fegsetround);
560 	ATF_TP_ADD_TC(tp, fegsetenv);
561 	ATF_TP_ADD_TC(tp, masking);
562 	ATF_TP_ADD_TC(tp, feholdupdate);
563 
564 	return (atf_no_error());
565 }
566