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 1.4 2014/12/27 17:54:24 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 #else 166 int fpscr = armreg_fpscr_read(); 167 armreg_fpscr_write(fpscr | __SHIFTIN((excepts), VFP_FPSCR_CSUM)); 168 return __SHIFTOUT(fpscr, VFP_FPSCR_CSUM) & FE_ALL_EXCEPT; 169 #endif 170 } 171 172 int 173 fedisableexcept(int excepts) 174 { 175 #ifndef lint 176 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 177 #endif 178 #ifdef __SOFTFP__ 179 int old = fpgetsticky(); 180 fpsetsticky(old & ~excepts); 181 return old; 182 #else 183 int fpscr = armreg_fpscr_read(); 184 armreg_fpscr_write(fpscr & ~__SHIFTIN((excepts), VFP_FPSCR_CSUM)); 185 return __SHIFTOUT(fpscr, VFP_FPSCR_CSUM) & FE_ALL_EXCEPT; 186 #endif 187 } 188 189 /* 190 * The fetestexcept() function shall determine which of a specified subset of 191 * the floating-point exception flags are currently set. The excepts argument 192 * specifies the floating-point status flags to be queried. 193 */ 194 int 195 fetestexcept(int excepts) 196 { 197 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0); 198 #ifdef __SOFTFP__ 199 return fpgetsticky() & excepts; 200 #else 201 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts; 202 #endif 203 } 204 205 int 206 fegetexcept(void) 207 { 208 return fetestexcept(FE_ALL_EXCEPT); 209 } 210 211 /* 212 * The fegetround() function shall get the current rounding direction. 213 */ 214 int 215 fegetround(void) 216 { 217 #ifdef __SOFTFP__ 218 return fpgetround(); 219 #else 220 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_RMODE); 221 #endif 222 } 223 224 /* 225 * The fesetround() function shall establish the rounding direction represented 226 * by its argument round. If the argument is not equal to the value of a 227 * rounding direction macro, the rounding direction is not changed. 228 */ 229 int 230 fesetround(int round) 231 { 232 #ifndef lint 233 _DIAGASSERT(!(round & ~__SHIFTOUT(VFP_FPSCR_RMODE, VFP_FPSCR_RMODE))); 234 #endif 235 #ifdef __SOFTFP__ 236 (void)fpsetround(round); 237 #else 238 int fpscr = armreg_fpscr_read() & ~VFP_FPSCR_RMODE; 239 fpscr |= __SHIFTIN(round, VFP_FPSCR_RMODE); 240 armreg_fpscr_write(fpscr); 241 #endif 242 return 0; 243 } 244 245 /* 246 * The fegetenv() function shall attempt to store the current floating-point 247 * environment in the object pointed to by envp. 248 */ 249 int 250 fegetenv(fenv_t *envp) 251 { 252 #ifdef __SOFTFP__ 253 *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE) 254 | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM) 255 | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM); 256 #else 257 *envp = armreg_fpscr_read(); 258 #endif 259 return 0; 260 } 261 262 /* 263 * The feholdexcept() function shall save the current floating-point 264 * environment in the object pointed to by envp, clear the floating-point 265 * status flags, and then install a non-stop (continue on floating-point 266 * exceptions) mode, if available, for all floating-point exceptions. 267 */ 268 int 269 feholdexcept(fenv_t *envp) 270 { 271 #ifdef __SOFTFP__ 272 *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE) 273 | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM) 274 | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM); 275 fpsetmask(0); 276 fpsetsticky(0); 277 #else 278 *envp = armreg_fpscr_read(); 279 armreg_fpscr_write((*envp) & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM)); 280 #endif 281 return 0; 282 } 283 284 /* 285 * The fesetenv() function shall attempt to establish the floating-point 286 * environment represented by the object pointed to by envp. The fesetenv() 287 * function does not raise floating-point exceptions, but only installs the 288 * state of the floating-point status flags represented through its argument. 289 */ 290 int 291 fesetenv(const fenv_t *envp) 292 { 293 #ifdef __SOFTFP__ 294 (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE)); 295 (void)fpsetmask(__SHIFTOUT(*envp, VFP_FPSCR_ESUM)); 296 (void)fpsetsticky(__SHIFTOUT(*envp, VFP_FPSCR_CSUM)); 297 #else 298 armreg_fpscr_write(*envp); 299 #endif 300 return 0; 301 } 302 303 /* 304 * The feupdateenv() function shall attempt to save the currently raised 305 * floating-point exceptions in its automatic storage, attempt to install the 306 * floating-point environment represented by the object pointed to by envp, 307 * and then attempt to raise the saved floating-point exceptions. 308 */ 309 int 310 feupdateenv(const fenv_t *envp) 311 { 312 #ifndef lint 313 _DIAGASSERT(envp != NULL); 314 #endif 315 #ifdef __SOFTFP__ 316 (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE)); 317 (void)fpsetmask(fpgetmask() | __SHIFTOUT(*envp, VFP_FPSCR_ESUM)); 318 (void)fpsetsticky(fpgetsticky() | __SHIFTOUT(*envp, VFP_FPSCR_CSUM)); 319 #else 320 int fpscr = armreg_fpscr_read() & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM); 321 fpscr |= *envp; 322 armreg_fpscr_write(fpscr); 323 #endif 324 325 /* Success */ 326 return 0; 327 } 328