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Guido van Rossum52fa3a61997-02-14 22:59:58 +00001/*
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
Guido van Rossum4622e142000-09-19 13:35:40 +000071#if defined(__FreeBSD__)
72# include <ieeefp.h>
73#endif
74
Guido van Rossum52fa3a61997-02-14 22:59:58 +000075#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.
78 */
Guido van Rossum1aeb1041997-03-14 04:32:25 +000079#include <setjmp.h>
Guido van Rossum52fa3a61997-02-14 22:59:58 +000080static jmp_buf PyFPE_jbuf;
81static int PyFPE_counter = 0;
82#endif
83
Tim Peters4f1b2082000-07-23 21:18:09 +000084typedef void Sigfunc(int);
Guido van Rossum52fa3a61997-02-14 22:59:58 +000085static Sigfunc sigfpe_handler;
86static void fpe_reset(Sigfunc *);
87
88static PyObject *fpe_error;
Guido van Rossum5de54201998-12-10 16:49:28 +000089DL_EXPORT(void) initfpectl(void);
Guido van Rossum52fa3a61997-02-14 22:59:58 +000090static PyObject *turnon_sigfpe (PyObject *self,PyObject *args);
91static PyObject *turnoff_sigfpe (PyObject *self,PyObject *args);
92
93static PyMethodDef fpectl_methods[] = {
94 {"turnon_sigfpe", (PyCFunction) turnon_sigfpe, 1},
95 {"turnoff_sigfpe", (PyCFunction) turnoff_sigfpe, 1},
96 {0,0}
97};
98
99static PyObject *turnon_sigfpe(PyObject *self,PyObject *args)
100{
101 /* Do any architecture-specific one-time only initialization here. */
102
103 fpe_reset(sigfpe_handler);
104 Py_INCREF (Py_None);
105 return Py_None;
106}
107
108static void fpe_reset(Sigfunc *handler)
109{
110 /* Reset the exception handling machinery, and reset the signal
111 * handler for SIGFPE to the given handler.
112 */
113
114/*-- IRIX -----------------------------------------------------------------*/
115#if defined(sgi)
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
121 */
122#include <sigfpe.h>
123 typedef void user_routine (unsigned[5], int[2]);
124 typedef void abort_routine (unsigned long);
125 handle_sigfpes(_OFF, 0,
126 (user_routine *)0,
127 _TURN_OFF_HANDLER_ON_ERROR,
Guido van Rossum1ed5e571997-04-29 21:34:16 +0000128 NULL);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000129 handle_sigfpes(_ON, _EN_OVERFL | _EN_DIVZERO | _EN_INVALID,
130 (user_routine *)0,
131 _ABORT_ON_ERROR,
Guido van Rossum1ed5e571997-04-29 21:34:16 +0000132 NULL);
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000133 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000134
135/*-- SunOS and Solaris ----------------------------------------------------*/
136#elif defined(sun)
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
141 */
142#include <math.h>
Martin v. Löwisc4db4762001-03-07 10:22:20 +0000143#ifndef _SUNMATH_H
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);
147#endif
148
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000149 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);
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000153 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000154
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 */
160#include <math.h>
161 fpsetdefaults();
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000162 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000163
164/*-- IBM AIX --------------------------------------------------------------*/
165#elif defined(__AIX) || defined(_AIX)
166 /* References: fp_trap, fp_enable man pages */
167#include <fptrap.h>
168 fp_trap(FP_TRAP_SYNC);
169 fp_enable(TRP_INVALID | TRP_DIV_BY_ZERO | TRP_OVERFLOW);
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000170 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000171
172/*-- DEC ALPHA OSF --------------------------------------------------------*/
Guido van Rossuma7379d91999-04-19 16:50:26 +0000173#elif defined(__alpha) && defined(__osf__)
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000174 /* 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);
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000181 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000182
183/*-- Cray Unicos ----------------------------------------------------------*/
184#elif defined(cray)
185 /* UNICOS delivers SIGFPE by default, but no matherr */
186#ifdef HAS_LIBMSET
187 libmset(-1);
188#endif
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000189 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000190
Guido van Rossum4622e142000-09-19 13:35:40 +0000191/*-- FreeBSD ----------------------------------------------------------------*/
192#elif defined(__FreeBSD__)
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000193 fpresetsticky(fpgetsticky());
194 fpsetmask(FP_X_INV | FP_X_DZ | FP_X_OFL);
195 PyOS_setsig(SIGFPE, handler);
Guido van Rossum4622e142000-09-19 13:35:40 +0000196
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000197/*-- Linux ----------------------------------------------------------------*/
198#elif defined(linux)
Guido van Rossumaa6fa6b1997-12-15 18:07:10 +0000199#ifdef __GLIBC__
200#include <fpu_control.h>
201#else
Guido van Rossume85da651997-10-20 23:50:01 +0000202#include <i386/fpu_control.h>
Guido van Rossumaa6fa6b1997-12-15 18:07:10 +0000203#endif
Andrew M. Kuchling5a571632001-01-04 01:01:12 +0000204#ifdef _FPU_SETCW
205 {
206 fpu_control_t cw = 0x1372;
207 _FPU_SETCW(cw);
208 }
209#else
Guido van Rossume85da651997-10-20 23:50:01 +0000210 __setfpucw(0x1372);
Andrew M. Kuchling5a571632001-01-04 01:01:12 +0000211#endif
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000212 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000213
214/*-- NeXT -----------------------------------------------------------------*/
215#elif defined(NeXT) && defined(m68k) && defined(__GNUC__)
216 /* NeXT needs explicit csr set to generate SIGFPE */
217 asm("fmovel #0x1400,fpcr"); /* set OVFL and ZD bits */
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000218 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000219
220/*-- Microsoft Windows, NT ------------------------------------------------*/
221#elif defined(_MSC_VER)
222 /* Reference: Visual C++ Books Online 4.2,
223 Run-Time Library Reference, _control87, _controlfp */
224#include <float.h>
225 unsigned int cw = _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW;
226 (void)_controlfp(0, cw);
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000227 PyOS_setsig(SIGFPE, handler);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000228
229/*-- Give Up --------------------------------------------------------------*/
230#else
231 fputs("Operation not implemented\n", stderr);
232#endif
233
234}
235
236static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args)
237{
Guido van Rossum4622e142000-09-19 13:35:40 +0000238#ifdef __FreeBSD__
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000239 fpresetsticky(fpgetsticky());
240 fpsetmask(0);
Guido van Rossum4622e142000-09-19 13:35:40 +0000241#else
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000242 fputs("Operation not implemented\n", stderr);
Guido van Rossum4622e142000-09-19 13:35:40 +0000243#endif
Guido van Rossumcf06571a2000-09-21 14:32:04 +0000244 Py_INCREF(Py_None);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000245 return Py_None;
246}
247
248static void sigfpe_handler(int signo)
249{
250 fpe_reset(sigfpe_handler);
251 if(PyFPE_counter) {
252 longjmp(PyFPE_jbuf, 1);
253 } else {
254 Py_FatalError("Unprotected floating point exception");
255 }
256}
257
Guido van Rossum3886bb61998-12-04 18:50:17 +0000258DL_EXPORT(void) initfpectl(void)
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000259{
260 PyObject *m, *d;
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000261 m = Py_InitModule("fpectl", fpectl_methods);
262 d = PyModule_GetDict(m);
Guido van Rossum0cb96de1997-10-01 04:29:29 +0000263 fpe_error = PyErr_NewException("fpectl.error", NULL, NULL);
264 if (fpe_error != NULL)
265 PyDict_SetItemString(d, "error", fpe_error);
Guido van Rossum52fa3a61997-02-14 22:59:58 +0000266}
267
268#ifdef __cplusplus
269}
270#endif