1 /* $NetBSD: t_fenv.c,v 1.13 2023/11/06 13:48:12 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Martin Husemann. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #include <sys/cdefs.h> 32 __RCSID("$NetBSD: t_fenv.c,v 1.13 2023/11/06 13:48:12 riastradh Exp $"); 33 34 #include <atf-c.h> 35 36 #include <fenv.h> 37 #ifdef __HAVE_FENV 38 39 /* XXXGCC gcc lacks #pragma STDC FENV_ACCESS */ 40 /* XXXclang clang lacks #pragma STDC FENV_ACCESS on some ports */ 41 #if !defined(__GNUC__) 42 #pragma STDC FENV_ACCESS ON 43 #endif 44 45 #include <float.h> 46 #include <ieeefp.h> 47 #include <stdlib.h> 48 49 #if FLT_RADIX != 2 50 #error This test assumes binary floating-point arithmetic. 51 #endif 52 53 #if (__arm__ && !__SOFTFP__) || __aarch64__ 54 /* 55 * Some NEON fpus do not trap on IEEE 754 FP exceptions. 56 * Skip these tests if running on them and compiled for 57 * hard float. 58 */ 59 #define FPU_EXC_PREREQ() \ 60 if (0 == fpsetmask(fpsetmask(FP_X_INV))) \ 61 atf_tc_skip("FPU does not implement traps on FP exceptions"); 62 63 /* 64 * Same as above: some don't allow configuring the rounding mode. 65 */ 66 #define FPU_RND_PREREQ() \ 67 if (0 == fpsetround(fpsetround(FP_RZ))) \ 68 atf_tc_skip("FPU does not implement configurable " \ 69 "rounding modes"); 70 #endif 71 72 #ifndef FPU_EXC_PREREQ 73 #define FPU_EXC_PREREQ() /* nothing */ 74 #endif 75 #ifndef FPU_RND_PREREQ 76 #define FPU_RND_PREREQ() /* nothing */ 77 #endif 78 79 80 static int 81 feround_to_fltrounds(int feround) 82 { 83 84 /* 85 * C99, Sec. 5.2.4.2.2 Characteristics of floating types 86 * <float.h>, p. 24, clause 7 87 */ 88 switch (feround) { 89 case FE_TOWARDZERO: 90 return 0; 91 case FE_TONEAREST: 92 return 1; 93 case FE_UPWARD: 94 return 2; 95 case FE_DOWNWARD: 96 return 3; 97 default: 98 return -1; 99 } 100 } 101 102 static void 103 checkfltrounds(void) 104 { 105 int feround = fegetround(); 106 int expected = feround_to_fltrounds(feround); 107 108 ATF_CHECK_EQ_MSG(FLT_ROUNDS, expected, 109 "FLT_ROUNDS=%d expected=%d fegetround()=%d", 110 FLT_ROUNDS, expected, feround); 111 } 112 113 static void 114 checkrounding(int feround, const char *name) 115 { 116 volatile double ulp1 = DBL_EPSILON; 117 118 /* 119 * XXX These must be volatile to force rounding to double when 120 * the intermediate quantities are evaluated in long double 121 * precision, e.g. on 32-bit x86 with x87 long double. Under 122 * the C standard (C99, C11, C17, &c.), cast and assignment 123 * operators are required to remove all extra range and 124 * precision, i.e., round double to long double. But we build 125 * this code with -std=gnu99, which diverges from this 126 * requirement -- unless you add a volatile qualifier. 127 */ 128 volatile double y1 = -1 + ulp1/4; 129 volatile double y2 = 1 + 3*(ulp1/2); 130 131 double z1, z2; 132 133 switch (feround) { 134 case FE_TONEAREST: 135 z1 = -1; 136 z2 = 1 + 2*ulp1; 137 break; 138 case FE_TOWARDZERO: 139 z1 = -1 + ulp1/2; 140 z2 = 1 + ulp1; 141 break; 142 case FE_UPWARD: 143 z1 = -1 + ulp1/2; 144 z2 = 1 + 2*ulp1; 145 break; 146 case FE_DOWNWARD: 147 z1 = -1; 148 z2 = 1 + ulp1; 149 break; 150 default: 151 atf_tc_fail("unknown rounding mode %d (%s)", feround, name); 152 } 153 154 ATF_CHECK_EQ_MSG(y1, z1, "%s[-1 + ulp(1)/4] expected=%a actual=%a", 155 name, y1, z1); 156 ATF_CHECK_EQ_MSG(y2, z2, "%s[1 + 3*(ulp(1)/2)] expected=%a actual=%a", 157 name, y2, z2); 158 } 159 160 ATF_TC(fegetround); 161 162 ATF_TC_HEAD(fegetround, tc) 163 { 164 atf_tc_set_md_var(tc, "descr", 165 "verify the fegetround() function agrees with the legacy " 166 "fpsetround"); 167 } 168 169 ATF_TC_BODY(fegetround, tc) 170 { 171 FPU_RND_PREREQ(); 172 173 checkrounding(FE_TONEAREST, "FE_TONEAREST"); 174 175 fpsetround(FP_RZ); 176 ATF_CHECK_EQ_MSG(fegetround(), FE_TOWARDZERO, 177 "fegetround()=%d FE_TOWARDZERO=%d", 178 fegetround(), FE_TOWARDZERO); 179 checkfltrounds(); 180 checkrounding(FE_TOWARDZERO, "FE_TOWARDZERO"); 181 182 fpsetround(FP_RM); 183 ATF_CHECK_EQ_MSG(fegetround(), FE_DOWNWARD, 184 "fegetround()=%d FE_DOWNWARD=%d", 185 fegetround(), FE_DOWNWARD); 186 checkfltrounds(); 187 checkrounding(FE_DOWNWARD, "FE_DOWNWARD"); 188 189 fpsetround(FP_RN); 190 ATF_CHECK_EQ_MSG(fegetround(), FE_TONEAREST, 191 "fegetround()=%d FE_TONEAREST=%d", 192 fegetround(), FE_TONEAREST); 193 checkfltrounds(); 194 checkrounding(FE_TONEAREST, "FE_TONEAREST"); 195 196 fpsetround(FP_RP); 197 ATF_CHECK_EQ_MSG(fegetround(), FE_UPWARD, 198 "fegetround()=%d FE_UPWARD=%d", 199 fegetround(), FE_UPWARD); 200 checkfltrounds(); 201 checkrounding(FE_UPWARD, "FE_UPWARD"); 202 } 203 204 ATF_TC(fesetround); 205 206 ATF_TC_HEAD(fesetround, tc) 207 { 208 atf_tc_set_md_var(tc, "descr", 209 "verify the fesetround() function agrees with the legacy " 210 "fpgetround"); 211 } 212 213 ATF_TC_BODY(fesetround, tc) 214 { 215 FPU_RND_PREREQ(); 216 217 checkrounding(FE_TONEAREST, "FE_TONEAREST"); 218 219 fesetround(FE_TOWARDZERO); 220 ATF_CHECK_EQ_MSG(fpgetround(), FP_RZ, 221 "fpgetround()=%d FP_RZ=%d", 222 (int)fpgetround(), (int)FP_RZ); 223 checkfltrounds(); 224 checkrounding(FE_TOWARDZERO, "FE_TOWARDZERO"); 225 226 fesetround(FE_DOWNWARD); 227 ATF_CHECK_EQ_MSG(fpgetround(), FP_RM, 228 "fpgetround()=%d FP_RM=%d", 229 (int)fpgetround(), (int)FP_RM); 230 checkfltrounds(); 231 checkrounding(FE_DOWNWARD, "FE_DOWNWARD"); 232 233 fesetround(FE_TONEAREST); 234 ATF_CHECK_EQ_MSG(fpgetround(), FP_RN, 235 "fpgetround()=%d FP_RN=%d", 236 (int)fpgetround(), (int)FP_RN); 237 checkfltrounds(); 238 checkrounding(FE_TONEAREST, "FE_TONEAREST"); 239 240 fesetround(FE_UPWARD); 241 ATF_CHECK_EQ_MSG(fpgetround(), FP_RP, 242 "fpgetround()=%d FP_RP=%d", 243 (int)fpgetround(), (int)FP_RP); 244 checkfltrounds(); 245 checkrounding(FE_UPWARD, "FE_UPWARD"); 246 } 247 248 ATF_TC(fegetexcept); 249 250 ATF_TC_HEAD(fegetexcept, tc) 251 { 252 atf_tc_set_md_var(tc, "descr", 253 "verify the fegetexcept() function agrees with the legacy " 254 "fpsetmask()"); 255 } 256 257 ATF_TC_BODY(fegetexcept, tc) 258 { 259 FPU_EXC_PREREQ(); 260 261 fpsetmask(0); 262 ATF_CHECK_EQ_MSG(fegetexcept(), 0, 263 "fegetexcept()=%d", 264 fegetexcept()); 265 266 fpsetmask(FP_X_INV|FP_X_DZ|FP_X_OFL|FP_X_UFL|FP_X_IMP); 267 ATF_CHECK(fegetexcept() == (FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW 268 |FE_UNDERFLOW|FE_INEXACT)); 269 270 fpsetmask(FP_X_INV); 271 ATF_CHECK_EQ_MSG(fegetexcept(), FE_INVALID, 272 "fegetexcept()=%d FE_INVALID=%d", 273 fegetexcept(), FE_INVALID); 274 275 fpsetmask(FP_X_DZ); 276 ATF_CHECK_EQ_MSG(fegetexcept(), FE_DIVBYZERO, 277 "fegetexcept()=%d FE_DIVBYZERO=%d", 278 fegetexcept(), FE_DIVBYZERO); 279 280 fpsetmask(FP_X_OFL); 281 ATF_CHECK_EQ_MSG(fegetexcept(), FE_OVERFLOW, 282 "fegetexcept()=%d FE_OVERFLOW=%d", 283 fegetexcept(), FE_OVERFLOW); 284 285 fpsetmask(FP_X_UFL); 286 ATF_CHECK_EQ_MSG(fegetexcept(), FE_UNDERFLOW, 287 "fegetexcept()=%d FE_UNDERFLOW=%d", 288 fegetexcept(), FE_UNDERFLOW); 289 290 fpsetmask(FP_X_IMP); 291 ATF_CHECK_EQ_MSG(fegetexcept(), FE_INEXACT, 292 "fegetexcept()=%d FE_INEXACT=%d", 293 fegetexcept(), FE_INEXACT); 294 } 295 296 ATF_TC(feenableexcept); 297 298 ATF_TC_HEAD(feenableexcept, tc) 299 { 300 atf_tc_set_md_var(tc, "descr", 301 "verify the feenableexcept() function agrees with the legacy " 302 "fpgetmask()"); 303 } 304 305 ATF_TC_BODY(feenableexcept, tc) 306 { 307 FPU_EXC_PREREQ(); 308 309 fedisableexcept(FE_ALL_EXCEPT); 310 ATF_CHECK_EQ_MSG(fpgetmask(), 0, 311 "fpgetmask()=%d", 312 (int)fpgetmask()); 313 314 feenableexcept(FE_UNDERFLOW); 315 ATF_CHECK_EQ_MSG(fpgetmask(), FP_X_UFL, 316 "fpgetmask()=%d FP_X_UFL=%d", 317 (int)fpgetmask(), (int)FP_X_UFL); 318 319 fedisableexcept(FE_ALL_EXCEPT); 320 feenableexcept(FE_OVERFLOW); 321 ATF_CHECK_EQ_MSG(fpgetmask(), FP_X_OFL, 322 "fpgetmask()=%d FP_X_OFL=%d", 323 (int)fpgetmask(), (int)FP_X_OFL); 324 325 fedisableexcept(FE_ALL_EXCEPT); 326 feenableexcept(FE_DIVBYZERO); 327 ATF_CHECK_EQ_MSG(fpgetmask(), FP_X_DZ, 328 "fpgetmask()=%d FP_X_DZ=%d", 329 (int)fpgetmask(), (int)FP_X_DZ); 330 331 fedisableexcept(FE_ALL_EXCEPT); 332 feenableexcept(FE_INEXACT); 333 ATF_CHECK_EQ_MSG(fpgetmask(), FP_X_IMP, 334 "fpgetmask()=%d FP_X_IMP=%d", 335 (int)fpgetmask(), (int)FP_X_IMP); 336 337 fedisableexcept(FE_ALL_EXCEPT); 338 feenableexcept(FE_INVALID); 339 ATF_CHECK_EQ_MSG(fpgetmask(), FP_X_INV, 340 "fpgetmask()=%d FP_X_INV=%d", 341 (int)fpgetmask(), (int)FP_X_INV); 342 } 343 344 ATF_TP_ADD_TCS(tp) 345 { 346 ATF_TP_ADD_TC(tp, fegetround); 347 ATF_TP_ADD_TC(tp, fesetround); 348 ATF_TP_ADD_TC(tp, fegetexcept); 349 ATF_TP_ADD_TC(tp, feenableexcept); 350 351 return atf_no_error(); 352 } 353 354 #else /* no fenv.h support */ 355 356 ATF_TC(t_nofenv); 357 358 ATF_TC_HEAD(t_nofenv, tc) 359 { 360 atf_tc_set_md_var(tc, "descr", 361 "dummy test case - no fenv.h support"); 362 } 363 364 365 ATF_TC_BODY(t_nofenv, tc) 366 { 367 atf_tc_skip("no fenv.h support on this architecture"); 368 } 369 370 ATF_TP_ADD_TCS(tp) 371 { 372 ATF_TP_ADD_TC(tp, t_nofenv); 373 return atf_no_error(); 374 } 375 376 #endif 377