source: vendor/python/2.5/Modules/fpectlmodule.c

Last change on this file was 3225, checked in by bird, 18 years ago

Python 2.5
File size: 10.9 KB
Line 
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
65extern "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>
84static jmp_buf PyFPE_jbuf;
85static int PyFPE_counter = 0;
86#endif
87
88typedef void Sigfunc(int);
89static Sigfunc sigfpe_handler;
90static void fpe_reset(Sigfunc *);
91
92static PyObject *fpe_error;
93PyMODINIT_FUNC initfpectl(void);
94static PyObject *turnon_sigfpe (PyObject *self,PyObject *args);
95static PyObject *turnoff_sigfpe (PyObject *self,PyObject *args);
96
97static PyMethodDef fpectl_methods[] = {
98 {"turnon_sigfpe", (PyCFunction) turnon_sigfpe, METH_VARARGS},
99 {"turnoff_sigfpe", (PyCFunction) turnoff_sigfpe, METH_VARARGS},
100 {0,0}
101};
102
103static 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
112static 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$ieee_set_fp_control(&clrmsk, &setmsk, 0);
206 PyOS_setsig(SIGFPE, handler);
207
208/*-- HP IA64 VMS --------------------------------------------------------*/
209#elif defined(__ia64) && defined(__VMS)
210 PyOS_setsig(SIGFPE, handler);
211
212/*-- Cray Unicos ----------------------------------------------------------*/
213#elif defined(cray)
214 /* UNICOS delivers SIGFPE by default, but no matherr */
215#ifdef HAS_LIBMSET
216 libmset(-1);
217#endif
218 PyOS_setsig(SIGFPE, handler);
219
220/*-- FreeBSD ----------------------------------------------------------------*/
221#elif defined(__FreeBSD__)
222 fpresetsticky(fpgetsticky());
223 fpsetmask(FP_X_INV | FP_X_DZ | FP_X_OFL);
224 PyOS_setsig(SIGFPE, handler);
225
226/*-- Linux ----------------------------------------------------------------*/
227#elif defined(linux)
228#ifdef __GLIBC__
229#include <fpu_control.h>
230#else
231#include <i386/fpu_control.h>
232#endif
233#ifdef _FPU_SETCW
234 {
235 fpu_control_t cw = 0x1372;
236 _FPU_SETCW(cw);
237 }
238#else
239 __setfpucw(0x1372);
240#endif
241 PyOS_setsig(SIGFPE, handler);
242
243/*-- Microsoft Windows, NT ------------------------------------------------*/
244#elif defined(_MSC_VER)
245 /* Reference: Visual C++ Books Online 4.2,
246 Run-Time Library Reference, _control87, _controlfp */
247#include <float.h>
248 unsigned int cw = _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW;
249 (void)_controlfp(0, cw);
250 PyOS_setsig(SIGFPE, handler);
251
252/*-- Give Up --------------------------------------------------------------*/
253#else
254 fputs("Operation not implemented\n", stderr);
255#endif
256
257}
258
259static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args)
260{
261#ifdef __FreeBSD__
262 fpresetsticky(fpgetsticky());
263 fpsetmask(0);
264#elif defined(__VMS)
265 IEEE clrmsk;
266 clrmsk.ieee$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
279static 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
289PyMODINIT_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
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