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 __FBSDID("$FreeBSD$"); 33 34 #include <sys/types.h> 35 #include <sys/wait.h> 36 #include <assert.h> 37 #include <err.h> 38 #include <fenv.h> 39 #include <float.h> 40 #include <math.h> 41 #include <signal.h> 42 #include <stdio.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #include "test-utils.h" 47 48 #define NEXCEPTS (sizeof(std_excepts) / sizeof(std_excepts[0])) 49 50 static const int std_excepts[] = { 51 FE_INVALID, 52 FE_DIVBYZERO, 53 FE_OVERFLOW, 54 FE_UNDERFLOW, 55 FE_INEXACT, 56 }; 57 58 /* init_exceptsets() initializes this to the power set of std_excepts[] */ 59 static int std_except_sets[1 << NEXCEPTS]; 60 61 #pragma STDC FENV_ACCESS ON 62 63 /* 64 * Initialize std_except_sets[] to the power set of std_excepts[] 65 */ 66 static void 67 init_exceptsets(void) 68 { 69 unsigned i, j, sr; 70 71 for (i = 0; i < 1 << NEXCEPTS; i++) { 72 for (sr = i, j = 0; sr != 0; sr >>= 1, j++) 73 std_except_sets[i] |= std_excepts[j] & ((~sr & 1) - 1); 74 } 75 } 76 77 /* 78 * Raise a floating-point exception without relying on the standard 79 * library routines, which we are trying to test. 80 * 81 * XXX We can't raise an {over,under}flow without also raising an 82 * inexact exception. 83 */ 84 static void 85 raiseexcept(int excepts) 86 { 87 volatile double d; 88 89 /* 90 * With a compiler that supports the FENV_ACCESS pragma 91 * properly, simple expressions like '0.0 / 0.0' should 92 * be sufficient to generate traps. Unfortunately, we 93 * need to bring a volatile variable into the equation 94 * to prevent incorrect optimizations. 95 */ 96 if (excepts & FE_INVALID) { 97 d = 0.0; 98 d = 0.0 / d; 99 } 100 if (excepts & FE_DIVBYZERO) { 101 d = 0.0; 102 d = 1.0 / d; 103 } 104 if (excepts & FE_OVERFLOW) { 105 d = DBL_MAX; 106 d *= 2.0; 107 } 108 if (excepts & FE_UNDERFLOW) { 109 d = DBL_MIN; 110 d /= DBL_MAX; 111 } 112 if (excepts & FE_INEXACT) { 113 d = DBL_MIN; 114 d += 1.0; 115 } 116 117 /* 118 * On the x86 (and some other architectures?) the FPU and 119 * integer units are decoupled. We need to execute an FWAIT 120 * or a floating-point instruction to get synchronous exceptions. 121 */ 122 d = 1.0; 123 d += 1.0; 124 } 125 126 /* 127 * Determine the current rounding mode without relying on the fenv 128 * routines. This function may raise an inexact exception. 129 */ 130 static int 131 getround(void) 132 { 133 volatile double d; 134 135 /* 136 * This test works just as well with 0.0 - 0.0, except on ia64 137 * where 0.0 - 0.0 gives the wrong sign when rounding downwards. 138 */ 139 d = 1.0; 140 d -= 1.0; 141 if (copysign(1.0, d) < 0.0) 142 return (FE_DOWNWARD); 143 144 d = 1.0; 145 if (d + (DBL_EPSILON * 3.0 / 4.0) == 1.0) 146 return (FE_TOWARDZERO); 147 if (d + (DBL_EPSILON * 1.0 / 4.0) > 1.0) 148 return (FE_UPWARD); 149 150 return (FE_TONEAREST); 151 } 152 153 static void 154 trap_handler(int sig) 155 { 156 157 assert(sig == SIGFPE); 158 _exit(0); 159 } 160 161 /* 162 * This tests checks the default FP environment, so it must be first. 163 * The memcmp() test below may be too much to ask for, since there 164 * could be multiple machine-specific default environments. 165 */ 166 static void 167 test_dfl_env(void) 168 { 169 #ifndef NO_STRICT_DFL_ENV 170 fenv_t env; 171 172 fegetenv(&env); 173 174 #ifdef __amd64__ 175 /* 176 * Compare the fields that the AMD [1] and Intel [2] specs say will be 177 * set once fnstenv returns. 178 * 179 * Not all amd64 capable processors implement the fnstenv instruction 180 * by zero'ing out the env.__x87.__other field (example: AMD Opteron 181 * 6308). The AMD64/x64 specs aren't explicit on what the 182 * env.__x87.__other field will contain after fnstenv is executed, so 183 * the values in env.__x87.__other could be filled with arbitrary 184 * data depending on how the CPU implements fnstenv. 185 * 186 * 1. http://support.amd.com/TechDocs/26569_APM_v5.pdf 187 * 2. http://www.intel.com/Assets/en_US/PDF/manual/253666.pdf 188 */ 189 assert(memcmp(&env.__mxcsr, &FE_DFL_ENV->__mxcsr, 190 sizeof(env.__mxcsr)) == 0); 191 assert(memcmp(&env.__x87.__control, &FE_DFL_ENV->__x87.__control, 192 sizeof(env.__x87.__control)) == 0); 193 assert(memcmp(&env.__x87.__status, &FE_DFL_ENV->__x87.__status, 194 sizeof(env.__x87.__status)) == 0); 195 assert(memcmp(&env.__x87.__tag, &FE_DFL_ENV->__x87.__tag, 196 sizeof(env.__x87.__tag)) == 0); 197 #else 198 assert(memcmp(&env, FE_DFL_ENV, sizeof(env)) == 0); 199 #endif 200 201 #endif 202 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 203 } 204 205 /* 206 * Test fetestexcept() and feclearexcept(). 207 */ 208 static void 209 test_fetestclearexcept(void) 210 { 211 int excepts, i; 212 213 for (i = 0; i < 1 << NEXCEPTS; i++) 214 assert(fetestexcept(std_except_sets[i]) == 0); 215 for (i = 0; i < 1 << NEXCEPTS; i++) { 216 excepts = std_except_sets[i]; 217 218 /* FE_ALL_EXCEPT might be special-cased, as on i386. */ 219 raiseexcept(excepts); 220 assert(fetestexcept(excepts) == excepts); 221 assert(feclearexcept(FE_ALL_EXCEPT) == 0); 222 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 223 224 raiseexcept(excepts); 225 assert(fetestexcept(excepts) == excepts); 226 if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0) { 227 excepts |= FE_INEXACT; 228 assert((fetestexcept(ALL_STD_EXCEPT) | FE_INEXACT) == 229 excepts); 230 } else { 231 assert(fetestexcept(ALL_STD_EXCEPT) == excepts); 232 } 233 assert(feclearexcept(excepts) == 0); 234 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 235 } 236 } 237 238 /* 239 * Test fegetexceptflag() and fesetexceptflag(). 240 * 241 * Prerequisites: fetestexcept(), feclearexcept() 242 */ 243 static void 244 test_fegsetexceptflag(void) 245 { 246 fexcept_t flag; 247 int excepts, i; 248 249 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 250 for (i = 0; i < 1 << NEXCEPTS; i++) { 251 excepts = std_except_sets[i]; 252 253 assert(fegetexceptflag(&flag, excepts) == 0); 254 raiseexcept(ALL_STD_EXCEPT); 255 assert(fesetexceptflag(&flag, excepts) == 0); 256 assert(fetestexcept(ALL_STD_EXCEPT) == 257 (ALL_STD_EXCEPT ^ excepts)); 258 259 assert(fegetexceptflag(&flag, FE_ALL_EXCEPT) == 0); 260 assert(feclearexcept(FE_ALL_EXCEPT) == 0); 261 assert(fesetexceptflag(&flag, excepts) == 0); 262 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 263 assert(fesetexceptflag(&flag, ALL_STD_EXCEPT ^ excepts) == 0); 264 assert(fetestexcept(ALL_STD_EXCEPT) == 265 (ALL_STD_EXCEPT ^ excepts)); 266 267 assert(feclearexcept(FE_ALL_EXCEPT) == 0); 268 } 269 } 270 271 /* 272 * Test feraiseexcept(). 273 * 274 * Prerequisites: fetestexcept(), feclearexcept() 275 */ 276 static void 277 test_feraiseexcept(void) 278 { 279 int excepts, i; 280 281 for (i = 0; i < 1 << NEXCEPTS; i++) { 282 excepts = std_except_sets[i]; 283 284 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 285 assert(feraiseexcept(excepts) == 0); 286 if ((excepts & (FE_UNDERFLOW | FE_OVERFLOW)) != 0) { 287 excepts |= FE_INEXACT; 288 assert((fetestexcept(ALL_STD_EXCEPT) | FE_INEXACT) == 289 excepts); 290 } else { 291 assert(fetestexcept(ALL_STD_EXCEPT) == excepts); 292 } 293 assert(feclearexcept(FE_ALL_EXCEPT) == 0); 294 } 295 assert(feraiseexcept(FE_INVALID | FE_DIVBYZERO) == 0); 296 assert(fetestexcept(ALL_STD_EXCEPT) == (FE_INVALID | FE_DIVBYZERO)); 297 assert(feraiseexcept(FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT) == 0); 298 assert(fetestexcept(ALL_STD_EXCEPT) == ALL_STD_EXCEPT); 299 assert(feclearexcept(FE_ALL_EXCEPT) == 0); 300 } 301 302 /* 303 * Test fegetround() and fesetround(). 304 */ 305 static void 306 test_fegsetround(void) 307 { 308 309 assert(fegetround() == FE_TONEAREST); 310 assert(getround() == FE_TONEAREST); 311 assert(FLT_ROUNDS == 1); 312 313 assert(fesetround(FE_DOWNWARD) == 0); 314 assert(fegetround() == FE_DOWNWARD); 315 assert(getround() == FE_DOWNWARD); 316 assert(FLT_ROUNDS == 3); 317 318 assert(fesetround(FE_UPWARD) == 0); 319 assert(getround() == FE_UPWARD); 320 assert(fegetround() == FE_UPWARD); 321 assert(FLT_ROUNDS == 2); 322 323 assert(fesetround(FE_TOWARDZERO) == 0); 324 assert(getround() == FE_TOWARDZERO); 325 assert(fegetround() == FE_TOWARDZERO); 326 assert(FLT_ROUNDS == 0); 327 328 assert(fesetround(FE_TONEAREST) == 0); 329 assert(getround() == FE_TONEAREST); 330 assert(FLT_ROUNDS == 1); 331 332 assert(feclearexcept(FE_ALL_EXCEPT) == 0); 333 } 334 335 /* 336 * Test fegetenv() and fesetenv(). 337 * 338 * Prerequisites: fetestexcept(), feclearexcept(), fegetround(), fesetround() 339 */ 340 static void 341 test_fegsetenv(void) 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 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 350 assert(fegetround() == FE_TONEAREST); 351 assert(fegetenv(&env1) == 0); 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 assert(feclearexcept(FE_INEXACT) == 0); 362 363 fesetround(FE_DOWNWARD); 364 assert(fegetenv(&env2) == 0); 365 assert(fesetenv(&env1) == 0); 366 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 367 assert(fegetround() == FE_TONEAREST); 368 369 assert(fesetenv(&env2) == 0); 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 assert((fetestexcept(FE_ALL_EXCEPT) & ALL_STD_EXCEPT) == excepts); 376 377 assert(fegetround() == FE_DOWNWARD); 378 assert(fesetenv(&env1) == 0); 379 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 380 assert(fegetround() == FE_TONEAREST); 381 } 382 } 383 384 /* 385 * Test fegetexcept(), fedisableexcept(), and feenableexcept(). 386 * 387 * Prerequisites: fetestexcept(), feraiseexcept() 388 */ 389 static void 390 test_masking(void) 391 { 392 struct sigaction act; 393 int except, pass, raise, status; 394 unsigned i; 395 396 assert((fegetexcept() & ALL_STD_EXCEPT) == 0); 397 assert((feenableexcept(FE_INVALID|FE_OVERFLOW) & ALL_STD_EXCEPT) == 0); 398 assert((feenableexcept(FE_UNDERFLOW) & ALL_STD_EXCEPT) == 399 (FE_INVALID | FE_OVERFLOW)); 400 assert((fedisableexcept(FE_OVERFLOW) & ALL_STD_EXCEPT) == 401 (FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)); 402 assert((fegetexcept() & ALL_STD_EXCEPT) == (FE_INVALID | FE_UNDERFLOW)); 403 assert((fedisableexcept(FE_ALL_EXCEPT) & ALL_STD_EXCEPT) == 404 (FE_INVALID | FE_UNDERFLOW)); 405 assert((fegetexcept() & ALL_STD_EXCEPT) == 0); 406 407 sigemptyset(&act.sa_mask); 408 act.sa_flags = 0; 409 act.sa_handler = trap_handler; 410 for (pass = 0; pass < 2; pass++) { 411 for (i = 0; i < NEXCEPTS; i++) { 412 except = std_excepts[i]; 413 /* over/underflow may also raise inexact */ 414 if (except == FE_INEXACT) 415 raise = FE_DIVBYZERO | FE_INVALID; 416 else 417 raise = ALL_STD_EXCEPT ^ except; 418 419 /* 420 * We need to fork a child process because 421 * there isn't a portable way to recover from 422 * a floating-point exception. 423 */ 424 switch(fork()) { 425 case 0: /* child */ 426 assert((fegetexcept() & ALL_STD_EXCEPT) == 0); 427 assert((feenableexcept(except) 428 & ALL_STD_EXCEPT) == 0); 429 assert(fegetexcept() == except); 430 raiseexcept(raise); 431 assert(feraiseexcept(raise) == 0); 432 assert(fetestexcept(ALL_STD_EXCEPT) == raise); 433 434 assert(sigaction(SIGFPE, &act, NULL) == 0); 435 switch (pass) { 436 case 0: 437 raiseexcept(except); 438 case 1: 439 feraiseexcept(except); 440 default: 441 assert(0); 442 } 443 assert(0); 444 default: /* parent */ 445 assert(wait(&status) > 0); 446 /* 447 * Avoid assert() here so that it's possible 448 * to examine a failed child's core dump. 449 */ 450 if (!WIFEXITED(status)) 451 errx(1, "child aborted\n"); 452 assert(WEXITSTATUS(status) == 0); 453 break; 454 case -1: /* error */ 455 assert(0); 456 } 457 } 458 } 459 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 460 } 461 462 /* 463 * Test feholdexcept() and feupdateenv(). 464 * 465 * Prerequisites: fetestexcept(), fegetround(), fesetround(), 466 * fedisableexcept(), feenableexcept() 467 */ 468 static void 469 test_feholdupdate(void) 470 { 471 fenv_t env; 472 473 struct sigaction act; 474 int except, pass, status, raise; 475 unsigned i; 476 477 sigemptyset(&act.sa_mask); 478 act.sa_flags = 0; 479 act.sa_handler = trap_handler; 480 for (pass = 0; pass < 2; pass++) { 481 for (i = 0; i < NEXCEPTS; i++) { 482 except = std_excepts[i]; 483 /* over/underflow may also raise inexact */ 484 if (except == FE_INEXACT) 485 raise = FE_DIVBYZERO | FE_INVALID; 486 else 487 raise = ALL_STD_EXCEPT ^ except; 488 489 /* 490 * We need to fork a child process because 491 * there isn't a portable way to recover from 492 * a floating-point exception. 493 */ 494 switch(fork()) { 495 case 0: /* child */ 496 /* 497 * We don't want to cause a fatal exception in 498 * the child until the second pass, so we can 499 * check other properties of feupdateenv(). 500 */ 501 if (pass == 1) 502 assert((feenableexcept(except) & 503 ALL_STD_EXCEPT) == 0); 504 raiseexcept(raise); 505 assert(fesetround(FE_DOWNWARD) == 0); 506 assert(feholdexcept(&env) == 0); 507 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 508 raiseexcept(except); 509 assert(fesetround(FE_UPWARD) == 0); 510 511 if (pass == 1) 512 assert(sigaction(SIGFPE, &act, NULL) == 513 0); 514 assert(feupdateenv(&env) == 0); 515 assert(fegetround() == FE_DOWNWARD); 516 assert(fetestexcept(ALL_STD_EXCEPT) == 517 (except | raise)); 518 519 assert(pass == 0); 520 _exit(0); 521 default: /* parent */ 522 assert(wait(&status) > 0); 523 /* 524 * Avoid assert() here so that it's possible 525 * to examine a failed child's core dump. 526 */ 527 if (!WIFEXITED(status)) 528 errx(1, "child aborted\n"); 529 assert(WEXITSTATUS(status) == 0); 530 break; 531 case -1: /* error */ 532 assert(0); 533 } 534 } 535 } 536 assert(fetestexcept(FE_ALL_EXCEPT) == 0); 537 } 538 539 int 540 main(void) 541 { 542 543 printf("1..8\n"); 544 init_exceptsets(); 545 test_dfl_env(); 546 printf("ok 1 - fenv\n"); 547 test_fetestclearexcept(); 548 printf("ok 2 - fenv\n"); 549 test_fegsetexceptflag(); 550 printf("ok 3 - fenv\n"); 551 test_feraiseexcept(); 552 printf("ok 4 - fenv\n"); 553 test_fegsetround(); 554 printf("ok 5 - fenv\n"); 555 test_fegsetenv(); 556 printf("ok 6 - fenv\n"); 557 test_masking(); 558 printf("ok 7 - fenv\n"); 559 test_feholdupdate(); 560 printf("ok 8 - fenv\n"); 561 562 return (0); 563 } 564