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 1.3 2013/05/01 04:04:54 matt 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_EXCEPT_ALL) == 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_EXCEPT_ALL) == 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_EXCEPT_ALL) == 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_EXCEPT_ALL) == 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 /* 157 * The fetestexcept() function shall determine which of a specified subset of 158 * the floating-point exception flags are currently set. The excepts argument 159 * specifies the floating-point status flags to be queried. 160 */ 161 int 162 fetestexcept(int excepts) 163 { 164 _DIAGASSERT((except & ~FE_EXCEPT_ALL) == 0); 165 #ifdef __SOFTFP__ 166 return fpgetsticky() & excepts; 167 #else 168 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts; 169 #endif 170 } 171 172 /* 173 * The fegetround() function shall get the current rounding direction. 174 */ 175 int 176 fegetround(void) 177 { 178 #ifdef __SOFTFP__ 179 return fpgetround(); 180 #else 181 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_RMODE); 182 #endif 183 } 184 185 /* 186 * The fesetround() function shall establish the rounding direction represented 187 * by its argument round. If the argument is not equal to the value of a 188 * rounding direction macro, the rounding direction is not changed. 189 */ 190 int 191 fesetround(int round) 192 { 193 #ifndef lint 194 _DIAGASSERT(!(round & ~__SHIFTOUT(VFP_FPSCR_RMODE, VFP_FPSCR_RMODE))); 195 #endif 196 #ifdef __SOFTFP__ 197 (void)fpsetround(round); 198 #else 199 int fpscr = armreg_fpscr_read() & ~VFP_FPSCR_RMODE; 200 fpscr |= __SHIFTIN(round, VFP_FPSCR_RMODE); 201 armreg_fpscr_write(fpscr); 202 #endif 203 return 0; 204 } 205 206 /* 207 * The fegetenv() function shall attempt to store the current floating-point 208 * environment in the object pointed to by envp. 209 */ 210 int 211 fegetenv(fenv_t *envp) 212 { 213 #ifdef __SOFTFP__ 214 *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE) 215 | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM) 216 | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM); 217 #else 218 *envp = armreg_fpscr_read(); 219 #endif 220 return 0; 221 } 222 223 /* 224 * The feholdexcept() function shall save the current floating-point 225 * environment in the object pointed to by envp, clear the floating-point 226 * status flags, and then install a non-stop (continue on floating-point 227 * exceptions) mode, if available, for all floating-point exceptions. 228 */ 229 int 230 feholdexcept(fenv_t *envp) 231 { 232 #ifdef __SOFTFP__ 233 *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE) 234 | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM) 235 | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM); 236 fpsetmask(0); 237 fpsetsticky(0); 238 #else 239 *envp = armreg_fpscr_read(); 240 armreg_fpscr_write((*envp) & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM)); 241 #endif 242 return 0; 243 } 244 245 /* 246 * The fesetenv() function shall attempt to establish the floating-point 247 * environment represented by the object pointed to by envp. The fesetenv() 248 * function does not raise floating-point exceptions, but only installs the 249 * state of the floating-point status flags represented through its argument. 250 */ 251 int 252 fesetenv(const fenv_t *envp) 253 { 254 #ifdef __SOFTFP__ 255 (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE)); 256 (void)fpsetmask(__SHIFTOUT(*envp, VFP_FPSCR_ESUM)); 257 (void)fpsetsticky(__SHIFTOUT(*envp, VFP_FPSCR_CSUM)); 258 #else 259 armreg_fpscr_write(*envp); 260 #endif 261 return 0; 262 } 263 264 /* 265 * The feupdateenv() function shall attempt to save the currently raised 266 * floating-point exceptions in its automatic storage, attempt to install the 267 * floating-point environment represented by the object pointed to by envp, 268 * and then attempt to raise the saved floating-point exceptions. 269 */ 270 int 271 feupdateenv(const fenv_t *envp) 272 { 273 #ifndef lint 274 _DIAGASSERT(envp != NULL); 275 #endif 276 #ifdef __SOFTFP__ 277 (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE)); 278 (void)fpsetmask(fpgetmask() | __SHIFTOUT(*envp, VFP_FPSCR_ESUM)); 279 (void)fpsetsticky(fpgetsticky() | __SHIFTOUT(*envp, VFP_FPSCR_CSUM)); 280 #else 281 int fpscr = armreg_fpscr_read() & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM); 282 fpscr |= *envp; 283 armreg_fpscr_write(fpscr); 284 #endif 285 286 /* Success */ 287 return 0; 288 } 289