1 /*- 2 * Copyright (c) 2013 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Matt Thomas of 3am Software Foundry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __RCSID("$NetBSD: fenv.c,v 1.5 2014/12/28 10:15:29 martin Exp $"); 32 33 #include <sys/types.h> 34 #include <assert.h> 35 #include <fenv.h> 36 #include <string.h> 37 #include <unistd.h> 38 #include <inttypes.h> 39 40 #ifdef __SOFTFP__ 41 #include <ieeefp.h> 42 #include <sys/signal.h> 43 #include <sys/siginfo.h> 44 #else 45 #include <arm/armreg.h> 46 #endif 47 48 #include <arm/vfpreg.h> 49 50 const fenv_t __fe_dfl_env = VFP_FPSCR_FZ|VFP_FPSCR_DN|VFP_FPSCR_RN; 51 52 /* 53 * The feclearexcept() function shall attempt to clear the supported 54 * floating-point exceptions represented by excepts. 55 */ 56 int 57 feclearexcept(int excepts) 58 { 59 #ifndef lint 60 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 61 #endif 62 #ifdef __SOFTFP__ 63 fpsetsticky(fpgetsticky() & ~excepts); 64 return 0; 65 #else 66 int tmp = armreg_fpscr_read() & ~__SHIFTIN(excepts, VFP_FPSCR_CSUM); 67 armreg_fpscr_write(tmp); 68 return 0; 69 #endif 70 } 71 72 /* 73 * The fegetexceptflag() function shall attempt to store an 74 * implementation-defined representation of the states of the floating-point 75 * status flags indicated by the argument excepts in the object pointed to by 76 * the argument flagp. 77 */ 78 int 79 fegetexceptflag(fexcept_t *flagp, int excepts) 80 { 81 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 82 #ifdef __SOFTFP__ 83 *flagp = fpgetsticky() & excepts; 84 #else 85 *flagp = __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts; 86 #endif 87 return 0; 88 } 89 90 /* 91 * The feraiseexcept() function shall attempt to raise the supported 92 * floating-point exceptions represented by the argument excepts. The order 93 * in which these floating-point exceptions are raised is unspecified. 94 */ 95 int 96 feraiseexcept(int excepts) 97 { 98 #ifndef lint 99 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 100 #endif 101 #ifdef __SOFTFP__ 102 excepts &= fpgetsticky(); 103 104 if (excepts) { 105 siginfo_t info; 106 memset(&info, 0, sizeof info); 107 info.si_signo = SIGFPE; 108 info.si_pid = getpid(); 109 info.si_uid = geteuid(); 110 if (excepts & FE_UNDERFLOW) 111 info.si_code = FPE_FLTUND; 112 else if (excepts & FE_OVERFLOW) 113 info.si_code = FPE_FLTOVF; 114 else if (excepts & FE_DIVBYZERO) 115 info.si_code = FPE_FLTDIV; 116 else if (excepts & FE_INVALID) 117 info.si_code = FPE_FLTINV; 118 else if (excepts & FE_INEXACT) 119 info.si_code = FPE_FLTRES; 120 sigqueueinfo(getpid(), &info); 121 } 122 #else 123 int fpscr = armreg_fpscr_read(); 124 fpscr = (fpscr & ~VFP_FPSCR_ESUM) | __SHIFTIN(excepts, VFP_FPSCR_ESUM); 125 armreg_fpscr_write(fpscr); 126 #endif 127 return 0; 128 } 129 130 /* 131 * The fesetexceptflag() function shall attempt to set the floating-point 132 * status flags indicated by the argument excepts to the states stored in the 133 * object pointed to by flagp. The value pointed to by flagp shall have been 134 * set by a previous call to fegetexceptflag() whose second argument 135 * represented at least those floating-point exceptions represented by the 136 * argument excepts. This function does not raise floating-point exceptions, 137 * but only sets the state of the flags. 138 */ 139 int 140 fesetexceptflag(const fexcept_t *flagp, int excepts) 141 { 142 #ifndef lint 143 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 144 #endif 145 #ifdef __SOFTFP__ 146 fpsetsticky((fpgetsticky() & ~excepts) | (excepts & *flagp)); 147 #else 148 int fpscr = armreg_fpscr_read(); 149 fpscr &= ~__SHIFTIN(excepts, VFP_FPSCR_CSUM); 150 fpscr |= __SHIFTIN((*flagp & excepts), VFP_FPSCR_CSUM); 151 armreg_fpscr_write(fpscr); 152 #endif 153 return 0; 154 } 155 156 int 157 feenableexcept(int excepts) 158 { 159 #ifndef lint 160 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 161 #endif 162 #ifdef __SOFTFP__ 163 int old = fpgetsticky(); 164 fpsetsticky(old | excepts); 165 return old; 166 #else 167 int fpscr = armreg_fpscr_read(); 168 armreg_fpscr_write(fpscr | __SHIFTIN((excepts), VFP_FPSCR_CSUM)); 169 return __SHIFTOUT(fpscr, VFP_FPSCR_CSUM) & FE_ALL_EXCEPT; 170 #endif 171 } 172 173 int 174 fedisableexcept(int excepts) 175 { 176 #ifndef lint 177 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 178 #endif 179 #ifdef __SOFTFP__ 180 int old = fpgetsticky(); 181 fpsetsticky(old & ~excepts); 182 return old; 183 #else 184 int fpscr = armreg_fpscr_read(); 185 armreg_fpscr_write(fpscr & ~__SHIFTIN((excepts), VFP_FPSCR_CSUM)); 186 return __SHIFTOUT(fpscr, VFP_FPSCR_CSUM) & FE_ALL_EXCEPT; 187 #endif 188 } 189 190 /* 191 * The fetestexcept() function shall determine which of a specified subset of 192 * the floating-point exception flags are currently set. The excepts argument 193 * specifies the floating-point status flags to be queried. 194 */ 195 int 196 fetestexcept(int excepts) 197 { 198 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 199 #ifdef __SOFTFP__ 200 return fpgetsticky() & excepts; 201 #else 202 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts; 203 #endif 204 } 205 206 int 207 fegetexcept(void) 208 { 209 return fetestexcept(FE_ALL_EXCEPT); 210 } 211 212 /* 213 * The fegetround() function shall get the current rounding direction. 214 */ 215 int 216 fegetround(void) 217 { 218 #ifdef __SOFTFP__ 219 return fpgetround(); 220 #else 221 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_RMODE); 222 #endif 223 } 224 225 /* 226 * The fesetround() function shall establish the rounding direction represented 227 * by its argument round. If the argument is not equal to the value of a 228 * rounding direction macro, the rounding direction is not changed. 229 */ 230 int 231 fesetround(int round) 232 { 233 #ifndef lint 234 _DIAGASSERT(!(round & ~__SHIFTOUT(VFP_FPSCR_RMODE, VFP_FPSCR_RMODE))); 235 #endif 236 #ifdef __SOFTFP__ 237 (void)fpsetround(round); 238 #else 239 int fpscr = armreg_fpscr_read() & ~VFP_FPSCR_RMODE; 240 fpscr |= __SHIFTIN(round, VFP_FPSCR_RMODE); 241 armreg_fpscr_write(fpscr); 242 #endif 243 return 0; 244 } 245 246 /* 247 * The fegetenv() function shall attempt to store the current floating-point 248 * environment in the object pointed to by envp. 249 */ 250 int 251 fegetenv(fenv_t *envp) 252 { 253 #ifdef __SOFTFP__ 254 *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE) 255 | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM) 256 | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM); 257 #else 258 *envp = armreg_fpscr_read(); 259 #endif 260 return 0; 261 } 262 263 /* 264 * The feholdexcept() function shall save the current floating-point 265 * environment in the object pointed to by envp, clear the floating-point 266 * status flags, and then install a non-stop (continue on floating-point 267 * exceptions) mode, if available, for all floating-point exceptions. 268 */ 269 int 270 feholdexcept(fenv_t *envp) 271 { 272 #ifdef __SOFTFP__ 273 *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE) 274 | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM) 275 | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM); 276 fpsetmask(0); 277 fpsetsticky(0); 278 #else 279 *envp = armreg_fpscr_read(); 280 armreg_fpscr_write((*envp) & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM)); 281 #endif 282 return 0; 283 } 284 285 /* 286 * The fesetenv() function shall attempt to establish the floating-point 287 * environment represented by the object pointed to by envp. The fesetenv() 288 * function does not raise floating-point exceptions, but only installs the 289 * state of the floating-point status flags represented through its argument. 290 */ 291 int 292 fesetenv(const fenv_t *envp) 293 { 294 #ifdef __SOFTFP__ 295 (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE)); 296 (void)fpsetmask(__SHIFTOUT(*envp, VFP_FPSCR_ESUM)); 297 (void)fpsetsticky(__SHIFTOUT(*envp, VFP_FPSCR_CSUM)); 298 #else 299 armreg_fpscr_write(*envp); 300 #endif 301 return 0; 302 } 303 304 /* 305 * The feupdateenv() function shall attempt to save the currently raised 306 * floating-point exceptions in its automatic storage, attempt to install the 307 * floating-point environment represented by the object pointed to by envp, 308 * and then attempt to raise the saved floating-point exceptions. 309 */ 310 int 311 feupdateenv(const fenv_t *envp) 312 { 313 #ifndef lint 314 _DIAGASSERT(envp != NULL); 315 #endif 316 #ifdef __SOFTFP__ 317 (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE)); 318 (void)fpsetmask(fpgetmask() | __SHIFTOUT(*envp, VFP_FPSCR_ESUM)); 319 (void)fpsetsticky(fpgetsticky() | __SHIFTOUT(*envp, VFP_FPSCR_CSUM)); 320 #else 321 int fpscr = armreg_fpscr_read() & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM); 322 fpscr |= *envp; 323 armreg_fpscr_write(fpscr); 324 #endif 325 326 /* Success */ 327 return 0; 328 } 329