Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 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 | #ifndef WANT_SIGFPE_HANDLER |
| 72 | /* Define locally if they are not defined in Python. This gives only |
| 73 | * the limited control to induce a core dump in case of an exception. |
| 74 | */ |
Guido van Rossum | 1aeb104 | 1997-03-14 04:32:25 +0000 | [diff] [blame] | 75 | #include <setjmp.h> |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 76 | static jmp_buf PyFPE_jbuf; |
| 77 | static int PyFPE_counter = 0; |
| 78 | #endif |
| 79 | |
Tim Peters | 4f1b208 | 2000-07-23 21:18:09 +0000 | [diff] [blame] | 80 | typedef void Sigfunc(int); |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 81 | static Sigfunc sigfpe_handler; |
| 82 | static void fpe_reset(Sigfunc *); |
| 83 | |
| 84 | static PyObject *fpe_error; |
Guido van Rossum | 5de5420 | 1998-12-10 16:49:28 +0000 | [diff] [blame] | 85 | DL_EXPORT(void) initfpectl(void); |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 86 | static PyObject *turnon_sigfpe (PyObject *self,PyObject *args); |
| 87 | static PyObject *turnoff_sigfpe (PyObject *self,PyObject *args); |
| 88 | |
| 89 | static PyMethodDef fpectl_methods[] = { |
| 90 | {"turnon_sigfpe", (PyCFunction) turnon_sigfpe, 1}, |
| 91 | {"turnoff_sigfpe", (PyCFunction) turnoff_sigfpe, 1}, |
| 92 | {0,0} |
| 93 | }; |
| 94 | |
| 95 | static PyObject *turnon_sigfpe(PyObject *self,PyObject *args) |
| 96 | { |
| 97 | /* Do any architecture-specific one-time only initialization here. */ |
| 98 | |
| 99 | fpe_reset(sigfpe_handler); |
| 100 | Py_INCREF (Py_None); |
| 101 | return Py_None; |
| 102 | } |
| 103 | |
| 104 | static void fpe_reset(Sigfunc *handler) |
| 105 | { |
| 106 | /* Reset the exception handling machinery, and reset the signal |
| 107 | * handler for SIGFPE to the given handler. |
| 108 | */ |
| 109 | |
| 110 | /*-- IRIX -----------------------------------------------------------------*/ |
| 111 | #if defined(sgi) |
| 112 | /* See man page on handle_sigfpes -- must link with -lfpe |
| 113 | * My usage doesn't follow the man page exactly. Maybe somebody |
| 114 | * else can explain handle_sigfpes to me.... |
| 115 | * cc -c -I/usr/local/python/include fpectlmodule.c |
| 116 | * ld -shared -o fpectlmodule.so fpectlmodule.o -lfpe |
| 117 | */ |
| 118 | #include <sigfpe.h> |
| 119 | typedef void user_routine (unsigned[5], int[2]); |
| 120 | typedef void abort_routine (unsigned long); |
| 121 | handle_sigfpes(_OFF, 0, |
| 122 | (user_routine *)0, |
| 123 | _TURN_OFF_HANDLER_ON_ERROR, |
Guido van Rossum | 1ed5e57 | 1997-04-29 21:34:16 +0000 | [diff] [blame] | 124 | NULL); |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 125 | handle_sigfpes(_ON, _EN_OVERFL | _EN_DIVZERO | _EN_INVALID, |
| 126 | (user_routine *)0, |
| 127 | _ABORT_ON_ERROR, |
Guido van Rossum | 1ed5e57 | 1997-04-29 21:34:16 +0000 | [diff] [blame] | 128 | NULL); |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 129 | signal(SIGFPE, handler); |
| 130 | |
| 131 | /*-- SunOS and Solaris ----------------------------------------------------*/ |
| 132 | #elif defined(sun) |
| 133 | /* References: ieee_handler, ieee_sun, ieee_functions, and ieee_flags |
| 134 | man pages (SunOS or Solaris) |
| 135 | cc -c -I/usr/local/python/include fpectlmodule.c |
| 136 | ld -G -o fpectlmodule.so -L/opt/SUNWspro/lib fpectlmodule.o -lsunmath -lm |
| 137 | */ |
| 138 | #include <math.h> |
| 139 | char *mode="exception", *in="all", *out; |
| 140 | (void) nonstandard_arithmetic(); |
| 141 | (void) ieee_flags("clearall",mode,in,&out); |
| 142 | (void) ieee_handler("set","common",(sigfpe_handler_type)handler); |
| 143 | signal(SIGFPE, handler); |
| 144 | |
| 145 | /*-- HPUX -----------------------------------------------------------------*/ |
| 146 | #elif defined(__hppa) || defined(hppa) |
| 147 | /* References: fpsetmask man page */ |
| 148 | /* cc -Aa +z -c -I/usr/local/python/include fpectlmodule.c */ |
| 149 | /* ld -b -o fpectlmodule.sl fpectlmodule.o -lm */ |
| 150 | #include <math.h> |
| 151 | fpsetdefaults(); |
| 152 | signal(SIGFPE, handler); |
| 153 | |
| 154 | /*-- IBM AIX --------------------------------------------------------------*/ |
| 155 | #elif defined(__AIX) || defined(_AIX) |
| 156 | /* References: fp_trap, fp_enable man pages */ |
| 157 | #include <fptrap.h> |
| 158 | fp_trap(FP_TRAP_SYNC); |
| 159 | fp_enable(TRP_INVALID | TRP_DIV_BY_ZERO | TRP_OVERFLOW); |
| 160 | signal(SIGFPE, handler); |
| 161 | |
| 162 | /*-- DEC ALPHA OSF --------------------------------------------------------*/ |
Guido van Rossum | a7379d9 | 1999-04-19 16:50:26 +0000 | [diff] [blame] | 163 | #elif defined(__alpha) && defined(__osf__) |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 164 | /* References: exception_intro, ieee man pages */ |
| 165 | /* cc -c -I/usr/local/python/include fpectlmodule.c */ |
| 166 | /* ld -shared -o fpectlmodule.so fpectlmodule.o */ |
| 167 | #include <machine/fpu.h> |
| 168 | unsigned long fp_control = |
| 169 | IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE | IEEE_TRAP_ENABLE_OVF; |
| 170 | ieee_set_fp_control(fp_control); |
| 171 | signal(SIGFPE, handler); |
| 172 | |
| 173 | /*-- Cray Unicos ----------------------------------------------------------*/ |
| 174 | #elif defined(cray) |
| 175 | /* UNICOS delivers SIGFPE by default, but no matherr */ |
| 176 | #ifdef HAS_LIBMSET |
| 177 | libmset(-1); |
| 178 | #endif |
| 179 | signal(SIGFPE, handler); |
| 180 | |
| 181 | /*-- Linux ----------------------------------------------------------------*/ |
| 182 | #elif defined(linux) |
Guido van Rossum | aa6fa6b | 1997-12-15 18:07:10 +0000 | [diff] [blame] | 183 | #ifdef __GLIBC__ |
| 184 | #include <fpu_control.h> |
| 185 | #else |
Guido van Rossum | e85da65 | 1997-10-20 23:50:01 +0000 | [diff] [blame] | 186 | #include <i386/fpu_control.h> |
Guido van Rossum | aa6fa6b | 1997-12-15 18:07:10 +0000 | [diff] [blame] | 187 | #endif |
Guido van Rossum | e85da65 | 1997-10-20 23:50:01 +0000 | [diff] [blame] | 188 | __setfpucw(0x1372); |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 189 | signal(SIGFPE, handler); |
| 190 | |
| 191 | /*-- NeXT -----------------------------------------------------------------*/ |
| 192 | #elif defined(NeXT) && defined(m68k) && defined(__GNUC__) |
| 193 | /* NeXT needs explicit csr set to generate SIGFPE */ |
| 194 | asm("fmovel #0x1400,fpcr"); /* set OVFL and ZD bits */ |
| 195 | signal(SIGFPE, handler); |
| 196 | |
| 197 | /*-- Microsoft Windows, NT ------------------------------------------------*/ |
| 198 | #elif defined(_MSC_VER) |
| 199 | /* Reference: Visual C++ Books Online 4.2, |
| 200 | Run-Time Library Reference, _control87, _controlfp */ |
| 201 | #include <float.h> |
| 202 | unsigned int cw = _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW; |
| 203 | (void)_controlfp(0, cw); |
| 204 | signal(SIGFPE, handler); |
| 205 | |
| 206 | /*-- Give Up --------------------------------------------------------------*/ |
| 207 | #else |
| 208 | fputs("Operation not implemented\n", stderr); |
| 209 | #endif |
| 210 | |
| 211 | } |
| 212 | |
| 213 | static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args) |
| 214 | { |
| 215 | fputs("Operation not implemented\n", stderr); |
| 216 | Py_INCREF (Py_None); |
| 217 | return Py_None; |
| 218 | } |
| 219 | |
| 220 | static void sigfpe_handler(int signo) |
| 221 | { |
| 222 | fpe_reset(sigfpe_handler); |
| 223 | if(PyFPE_counter) { |
| 224 | longjmp(PyFPE_jbuf, 1); |
| 225 | } else { |
| 226 | Py_FatalError("Unprotected floating point exception"); |
| 227 | } |
| 228 | } |
| 229 | |
Guido van Rossum | 3886bb6 | 1998-12-04 18:50:17 +0000 | [diff] [blame] | 230 | DL_EXPORT(void) initfpectl(void) |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 231 | { |
| 232 | PyObject *m, *d; |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 233 | m = Py_InitModule("fpectl", fpectl_methods); |
| 234 | d = PyModule_GetDict(m); |
Guido van Rossum | 0cb96de | 1997-10-01 04:29:29 +0000 | [diff] [blame] | 235 | fpe_error = PyErr_NewException("fpectl.error", NULL, NULL); |
| 236 | if (fpe_error != NULL) |
| 237 | PyDict_SetItemString(d, "error", fpe_error); |
Guido van Rossum | 52fa3a6 | 1997-02-14 22:59:58 +0000 | [diff] [blame] | 238 | } |
| 239 | |
| 240 | #ifdef __cplusplus |
| 241 | } |
| 242 | #endif |