1 /* 2 --------------------------------------------------------------------- 3 / Copyright (c) 1996. \ 4 | The Regents of the University of California. | 5 | All rights reserved. | 6 | | 7 | Permission to use, copy, modify, and distribute this software for | 8 | any purpose without fee is hereby granted, provided that this en- | 9 | tire notice is included in all copies of any software which is or | 10 | includes a copy or modification of this software and in all | 11 | copies of the supporting documentation for such software. | 12 | | 13 | This work was produced at the University of California, Lawrence | 14 | Livermore National Laboratory under contract no. W-7405-ENG-48 | 15 | between the U.S. Department of Energy and The Regents of the | 16 | University of California for the operation of UC LLNL. | 17 | | 18 | DISCLAIMER | 19 | | 20 | This software was prepared as an account of work sponsored by an | 21 | agency of the United States Government. Neither the United States | 22 | Government nor the University of California nor any of their em- | 23 | ployees, makes any warranty, express or implied, or assumes any | 24 | liability or responsibility for the accuracy, completeness, or | 25 | usefulness of any information, apparatus, product, or process | 26 | disclosed, or represents that its use would not infringe | 27 | privately-owned rights. Reference herein to any specific commer- | 28 | cial products, process, or service by trade name, trademark, | 29 | manufacturer, or otherwise, does not necessarily constitute or | 30 | imply its endorsement, recommendation, or favoring by the United | 31 | States Government or the University of California. The views and | 32 | opinions of authors expressed herein do not necessarily state or | 33 | reflect those of the United States Government or the University | 34 | of California, and shall not be used for advertising or product | 35 \ endorsement purposes. / 36 --------------------------------------------------------------------- 37 */ 38 39 /* 40 Floating point exception control module. 41 42 This Python module provides bare-bones control over floating point 43 units from several hardware manufacturers. Specifically, it allows 44 the user to turn on the generation of SIGFPE whenever any of the 45 three serious IEEE 754 exceptions (Division by Zero, Overflow, 46 Invalid Operation) occurs. We currently ignore Underflow and 47 Inexact Result exceptions, although those could certainly be added 48 if desired. 49 50 The module also establishes a signal handler for SIGFPE during 51 initialization. This builds on code found in the Python 52 distribution at Include/pyfpe.h and Python/pyfpe.c. If those files 53 are not in your Python distribution, find them in a patch at 54 ftp://icf.llnl.gov/pub/python/busby/patches.961108.tgz. 55 56 This module is only useful to you if it happens to include code 57 specific for your hardware and software environment. If you can 58 contribute OS-specific code for new platforms, or corrections for 59 the code provided, it will be greatly appreciated. 60 61 ** Version 1.0: September 20, 1996. Lee Busby, LLNL. 62 */ 63 64 #ifdef __cplusplus 65 extern "C" { 66 #endif 67 68 #include "Python.h" 69 #include <signal.h> 70 71 #if defined(__FreeBSD__) 72 # include <ieeefp.h> 73 #elif defined(__VMS) 74 #define __NEW_STARLET 75 #include <starlet.h> 76 #include <ieeedef.h> 77 #endif 78 79 #ifndef WANT_SIGFPE_HANDLER 80 /* Define locally if they are not defined in Python. This gives only 81 * the limited control to induce a core dump in case of an exception. 82 */ 83 #include <setjmp.h> 84 static jmp_buf PyFPE_jbuf; 85 static int PyFPE_counter = 0; 86 #endif 87 88 typedef void Sigfunc(int); 89 static Sigfunc sigfpe_handler; 90 static void fpe_reset(Sigfunc *); 91 92 static PyObject *fpe_error; 93 PyMODINIT_FUNC initfpectl(void); 94 static PyObject *turnon_sigfpe (PyObject *self,PyObject *args); 95 static PyObject *turnoff_sigfpe (PyObject *self,PyObject *args); 96 97 static PyMethodDef fpectl_methods[] = { 98 {"turnon_sigfpe", (PyCFunction) turnon_sigfpe, METH_VARARGS}, 99 {"turnoff_sigfpe", (PyCFunction) turnoff_sigfpe, METH_VARARGS}, 100 {0,0} 101 }; 102 103 static PyObject *turnon_sigfpe(PyObject *self,PyObject *args) 104 { 105 /* Do any architecture-specific one-time only initialization here. */ 106 107 fpe_reset(sigfpe_handler); 108 Py_INCREF (Py_None); 109 return Py_None; 110 } 111 112 static void fpe_reset(Sigfunc *handler) 113 { 114 /* Reset the exception handling machinery, and reset the signal 115 * handler for SIGFPE to the given handler. 116 */ 117 118 /*-- IRIX -----------------------------------------------------------------*/ 119 #if defined(sgi) 120 /* See man page on handle_sigfpes -- must link with -lfpe 121 * My usage doesn't follow the man page exactly. Maybe somebody 122 * else can explain handle_sigfpes to me.... 123 * cc -c -I/usr/local/python/include fpectlmodule.c 124 * ld -shared -o fpectlmodule.so fpectlmodule.o -lfpe 125 */ 126 #include <sigfpe.h> 127 typedef void user_routine (unsigned[5], int[2]); 128 typedef void abort_routine (unsigned long); 129 handle_sigfpes(_OFF, 0, 130 (user_routine *)0, 131 _TURN_OFF_HANDLER_ON_ERROR, 132 NULL); 133 handle_sigfpes(_ON, _EN_OVERFL | _EN_DIVZERO | _EN_INVALID, 134 (user_routine *)0, 135 _ABORT_ON_ERROR, 136 NULL); 137 PyOS_setsig(SIGFPE, handler); 138 139 /*-- SunOS and Solaris ----------------------------------------------------*/ 140 #elif defined(sun) 141 /* References: ieee_handler, ieee_sun, ieee_functions, and ieee_flags 142 man pages (SunOS or Solaris) 143 cc -c -I/usr/local/python/include fpectlmodule.c 144 ld -G -o fpectlmodule.so -L/opt/SUNWspro/lib fpectlmodule.o -lsunmath -lm 145 */ 146 #include <math.h> 147 #ifndef _SUNMATH_H 148 extern void nonstandard_arithmetic(void); 149 extern int ieee_flags(const char*, const char*, const char*, char **); 150 extern long ieee_handler(const char*, const char*, sigfpe_handler_type); 151 #endif 152 153 char *mode="exception", *in="all", *out; 154 (void) nonstandard_arithmetic(); 155 (void) ieee_flags("clearall",mode,in,&out); 156 (void) ieee_handler("set","common",(sigfpe_handler_type)handler); 157 PyOS_setsig(SIGFPE, handler); 158 159 /*-- HPUX -----------------------------------------------------------------*/ 160 #elif defined(__hppa) || defined(hppa) 161 /* References: fpsetmask man page */ 162 /* cc -Aa +z -c -I/usr/local/python/include fpectlmodule.c */ 163 /* ld -b -o fpectlmodule.sl fpectlmodule.o -lm */ 164 #include <math.h> 165 fpsetdefaults(); 166 PyOS_setsig(SIGFPE, handler); 167 168 /*-- IBM AIX --------------------------------------------------------------*/ 169 #elif defined(__AIX) || defined(_AIX) 170 /* References: fp_trap, fp_enable man pages */ 171 #include <fptrap.h> 172 fp_trap(FP_TRAP_SYNC); 173 fp_enable(TRP_INVALID | TRP_DIV_BY_ZERO | TRP_OVERFLOW); 174 PyOS_setsig(SIGFPE, handler); 175 176 /*-- DEC ALPHA OSF --------------------------------------------------------*/ 177 #elif defined(__alpha) && defined(__osf__) 178 /* References: exception_intro, ieee man pages */ 179 /* cc -c -I/usr/local/python/include fpectlmodule.c */ 180 /* ld -shared -o fpectlmodule.so fpectlmodule.o */ 181 #include <machine/fpu.h> 182 unsigned long fp_control = 183 IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE | IEEE_TRAP_ENABLE_OVF; 184 ieee_set_fp_control(fp_control); 185 PyOS_setsig(SIGFPE, handler); 186 187 /*-- DEC ALPHA LINUX ------------------------------------------------------*/ 188 #elif defined(__alpha) && defined(linux) 189 #include <asm/fpu.h> 190 unsigned long fp_control = 191 IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE | IEEE_TRAP_ENABLE_OVF; 192 ieee_set_fp_control(fp_control); 193 PyOS_setsig(SIGFPE, handler); 194 195 /*-- DEC ALPHA VMS --------------------------------------------------------*/ 196 #elif defined(__ALPHA) && defined(__VMS) 197 IEEE clrmsk; 198 IEEE setmsk; 199 clrmsk.ieee$q_flags = 200 IEEE$M_TRAP_ENABLE_UNF | IEEE$M_TRAP_ENABLE_INE | 201 IEEE$M_MAP_UMZ; 202 setmsk.ieee$q_flags = 203 IEEE$M_TRAP_ENABLE_INV | IEEE$M_TRAP_ENABLE_DZE | 204 IEEE$M_TRAP_ENABLE_OVF; 205 sys$ieee_set_fp_control(&clrmsk, &setmsk, 0); 206 PyOS_setsig(SIGFPE, handler); 207 208 /*-- HP IA64 VMS --------------------------------------------------------*/ 209 #elif defined(__ia64) && defined(__VMS) 210 PyOS_setsig(SIGFPE, handler); 211 212 /*-- Cray Unicos ----------------------------------------------------------*/ 213 #elif defined(cray) 214 /* UNICOS delivers SIGFPE by default, but no matherr */ 215 #ifdef HAS_LIBMSET 216 libmset(-1); 217 #endif 218 PyOS_setsig(SIGFPE, handler); 219 220 /*-- FreeBSD ----------------------------------------------------------------*/ 221 #elif defined(__FreeBSD__) 222 fpresetsticky(fpgetsticky()); 223 fpsetmask(FP_X_INV | FP_X_DZ | FP_X_OFL); 224 PyOS_setsig(SIGFPE, handler); 225 226 /*-- Linux ----------------------------------------------------------------*/ 227 #elif defined(linux) 228 #ifdef __GLIBC__ 229 #include <fpu_control.h> 230 #else 231 #include <i386/fpu_control.h> 232 #endif 233 #ifdef _FPU_SETCW 234 { 235 fpu_control_t cw = 0x1372; 236 _FPU_SETCW(cw); 237 } 238 #else 239 __setfpucw(0x1372); 240 #endif 241 PyOS_setsig(SIGFPE, handler); 242 243 /*-- Microsoft Windows, NT ------------------------------------------------*/ 244 #elif defined(_MSC_VER) 245 /* Reference: Visual C++ Books Online 4.2, 246 Run-Time Library Reference, _control87, _controlfp */ 247 #include <float.h> 248 unsigned int cw = _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW; 249 (void)_controlfp(0, cw); 250 PyOS_setsig(SIGFPE, handler); 251 252 /*-- Give Up --------------------------------------------------------------*/ 253 #else 254 fputs("Operation not implemented\n", stderr); 255 #endif 256 257 } 258 259 static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args) 260 { 261 #ifdef __FreeBSD__ 262 fpresetsticky(fpgetsticky()); 263 fpsetmask(0); 264 #elif defined(__VMS) 265 IEEE clrmsk; 266 clrmsk.ieee$q_flags = 267 IEEE$M_TRAP_ENABLE_UNF | IEEE$M_TRAP_ENABLE_INE | 268 IEEE$M_MAP_UMZ | IEEE$M_TRAP_ENABLE_INV | 269 IEEE$M_TRAP_ENABLE_DZE | IEEE$M_TRAP_ENABLE_OVF | 270 IEEE$M_INHERIT; 271 sys$ieee_set_fp_control(&clrmsk, 0, 0); 272 #else 273 fputs("Operation not implemented\n", stderr); 274 #endif 275 Py_INCREF(Py_None); 276 return Py_None; 277 } 278 279 static void sigfpe_handler(int signo) 280 { 281 fpe_reset(sigfpe_handler); 282 if(PyFPE_counter) { 283 longjmp(PyFPE_jbuf, 1); 284 } else { 285 Py_FatalError("Unprotected floating point exception"); 286 } 287 } 288 289 PyMODINIT_FUNC initfpectl(void) 290 { 291 PyObject *m, *d; 292 m = Py_InitModule("fpectl", fpectl_methods); 293 if (m == NULL) 294 return; 295 d = PyModule_GetDict(m); 296 fpe_error = PyErr_NewException("fpectl.error", NULL, NULL); 297 if (fpe_error != NULL) 298 PyDict_SetItemString(d, "error", fpe_error); 299 } 300 301 #ifdef __cplusplus 302 } 303 #endif 304
