2 ---------------------------------------------------------------------
3 / Copyright (c) 1996. \
4 | The Regents of the University of California. |
5 | All rights reserved. |
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. |
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. |
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 ---------------------------------------------------------------------
40 Floating point exception control module.
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
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.
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.
61 ** Version 1.0: September 20, 1996. Lee Busby, LLNL.
71 #if defined(__FreeBSD__)
75 #ifndef WANT_SIGFPE_HANDLER
76 /* Define locally if they are not defined in Python. This gives only
77 * the limited control to induce a core dump in case of an exception.
80 static jmp_buf PyFPE_jbuf
;
81 static int PyFPE_counter
= 0;
84 typedef void Sigfunc(int);
85 static Sigfunc sigfpe_handler
;
86 static void fpe_reset(Sigfunc
*);
88 static PyObject
*fpe_error
;
89 PyMODINIT_FUNC
initfpectl(void);
90 static PyObject
*turnon_sigfpe (PyObject
*self
,PyObject
*args
);
91 static PyObject
*turnoff_sigfpe (PyObject
*self
,PyObject
*args
);
93 static PyMethodDef fpectl_methods
[] = {
94 {"turnon_sigfpe", (PyCFunction
) turnon_sigfpe
, METH_VARARGS
},
95 {"turnoff_sigfpe", (PyCFunction
) turnoff_sigfpe
, METH_VARARGS
},
99 static PyObject
*turnon_sigfpe(PyObject
*self
,PyObject
*args
)
101 /* Do any architecture-specific one-time only initialization here. */
103 fpe_reset(sigfpe_handler
);
108 static void fpe_reset(Sigfunc
*handler
)
110 /* Reset the exception handling machinery, and reset the signal
111 * handler for SIGFPE to the given handler.
114 /*-- IRIX -----------------------------------------------------------------*/
116 /* See man page on handle_sigfpes -- must link with -lfpe
117 * My usage doesn't follow the man page exactly. Maybe somebody
118 * else can explain handle_sigfpes to me....
119 * cc -c -I/usr/local/python/include fpectlmodule.c
120 * ld -shared -o fpectlmodule.so fpectlmodule.o -lfpe
123 typedef void user_routine (unsigned[5], int[2]);
124 typedef void abort_routine (unsigned long);
125 handle_sigfpes(_OFF
, 0,
127 _TURN_OFF_HANDLER_ON_ERROR
,
129 handle_sigfpes(_ON
, _EN_OVERFL
| _EN_DIVZERO
| _EN_INVALID
,
133 PyOS_setsig(SIGFPE
, handler
);
135 /*-- SunOS and Solaris ----------------------------------------------------*/
137 /* References: ieee_handler, ieee_sun, ieee_functions, and ieee_flags
138 man pages (SunOS or Solaris)
139 cc -c -I/usr/local/python/include fpectlmodule.c
140 ld -G -o fpectlmodule.so -L/opt/SUNWspro/lib fpectlmodule.o -lsunmath -lm
144 extern void nonstandard_arithmetic(void);
145 extern int ieee_flags(const char*, const char*, const char*, char **);
146 extern long ieee_handler(const char*, const char*, sigfpe_handler_type
);
149 char *mode
="exception", *in
="all", *out
;
150 (void) nonstandard_arithmetic();
151 (void) ieee_flags("clearall",mode
,in
,&out
);
152 (void) ieee_handler("set","common",(sigfpe_handler_type
)handler
);
153 PyOS_setsig(SIGFPE
, handler
);
155 /*-- HPUX -----------------------------------------------------------------*/
156 #elif defined(__hppa) || defined(hppa)
157 /* References: fpsetmask man page */
158 /* cc -Aa +z -c -I/usr/local/python/include fpectlmodule.c */
159 /* ld -b -o fpectlmodule.sl fpectlmodule.o -lm */
162 PyOS_setsig(SIGFPE
, handler
);
164 /*-- IBM AIX --------------------------------------------------------------*/
165 #elif defined(__AIX) || defined(_AIX)
166 /* References: fp_trap, fp_enable man pages */
168 fp_trap(FP_TRAP_SYNC
);
169 fp_enable(TRP_INVALID
| TRP_DIV_BY_ZERO
| TRP_OVERFLOW
);
170 PyOS_setsig(SIGFPE
, handler
);
172 /*-- DEC ALPHA OSF --------------------------------------------------------*/
173 #elif defined(__alpha) && defined(__osf__)
174 /* References: exception_intro, ieee man pages */
175 /* cc -c -I/usr/local/python/include fpectlmodule.c */
176 /* ld -shared -o fpectlmodule.so fpectlmodule.o */
177 #include <machine/fpu.h>
178 unsigned long fp_control
=
179 IEEE_TRAP_ENABLE_INV
| IEEE_TRAP_ENABLE_DZE
| IEEE_TRAP_ENABLE_OVF
;
180 ieee_set_fp_control(fp_control
);
181 PyOS_setsig(SIGFPE
, handler
);
183 /*-- DEC ALPHA LINUX ------------------------------------------------------*/
184 #elif defined(__alpha) && defined(linux)
186 unsigned long fp_control
=
187 IEEE_TRAP_ENABLE_INV
| IEEE_TRAP_ENABLE_DZE
| IEEE_TRAP_ENABLE_OVF
;
188 ieee_set_fp_control(fp_control
);
189 PyOS_setsig(SIGFPE
, handler
);
191 /*-- DEC ALPHA VMS --------------------------------------------------------*/
192 #elif defined(__ALPHA) && defined(__VMS)
193 PyOS_setsig(SIGFPE
, handler
);
195 /*-- Cray Unicos ----------------------------------------------------------*/
197 /* UNICOS delivers SIGFPE by default, but no matherr */
201 PyOS_setsig(SIGFPE
, handler
);
203 /*-- FreeBSD ----------------------------------------------------------------*/
204 #elif defined(__FreeBSD__)
205 fpresetsticky(fpgetsticky());
206 fpsetmask(FP_X_INV
| FP_X_DZ
| FP_X_OFL
);
207 PyOS_setsig(SIGFPE
, handler
);
209 /*-- Linux ----------------------------------------------------------------*/
212 #include <fpu_control.h>
214 #include <i386/fpu_control.h>
218 fpu_control_t cw
= 0x1372;
224 PyOS_setsig(SIGFPE
, handler
);
226 /*-- Microsoft Windows, NT ------------------------------------------------*/
227 #elif defined(_MSC_VER)
228 /* Reference: Visual C++ Books Online 4.2,
229 Run-Time Library Reference, _control87, _controlfp */
231 unsigned int cw
= _EM_INVALID
| _EM_ZERODIVIDE
| _EM_OVERFLOW
;
232 (void)_controlfp(0, cw
);
233 PyOS_setsig(SIGFPE
, handler
);
235 /*-- Give Up --------------------------------------------------------------*/
237 fputs("Operation not implemented\n", stderr
);
242 static PyObject
*turnoff_sigfpe(PyObject
*self
,PyObject
*args
)
245 fpresetsticky(fpgetsticky());
248 fputs("Operation not implemented\n", stderr
);
254 static void sigfpe_handler(int signo
)
256 fpe_reset(sigfpe_handler
);
258 longjmp(PyFPE_jbuf
, 1);
260 Py_FatalError("Unprotected floating point exception");
264 PyMODINIT_FUNC
initfpectl(void)
267 m
= Py_InitModule("fpectl", fpectl_methods
);
268 d
= PyModule_GetDict(m
);
269 fpe_error
= PyErr_NewException("fpectl.error", NULL
, NULL
);
270 if (fpe_error
!= NULL
)
271 PyDict_SetItemString(d
, "error", fpe_error
);