245 lines
9.3 KiB
C
245 lines
9.3 KiB
C
/*
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---------------------------------------------------------------------
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/ Copyright (c) 1996. \
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| The Regents of the University of California. |
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| All rights reserved. |
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| Permission to use, copy, modify, and distribute this software for |
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| any purpose without fee is hereby granted, provided that this en- |
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| tire notice is included in all copies of any software which is or |
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| includes a copy or modification of this software and in all |
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| copies of the supporting documentation for such software. |
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| |
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| This work was produced at the University of California, Lawrence |
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| Livermore National Laboratory under contract no. W-7405-ENG-48 |
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| between the U.S. Department of Energy and The Regents of the |
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| University of California for the operation of UC LLNL. |
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| DISCLAIMER |
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| This software was prepared as an account of work sponsored by an |
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| agency of the United States Government. Neither the United States |
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| Government nor the University of California nor any of their em- |
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| ployees, makes any warranty, express or implied, or assumes any |
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| liability or responsibility for the accuracy, completeness, or |
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| usefulness of any information, apparatus, product, or process |
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| disclosed, or represents that its use would not infringe |
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| privately-owned rights. Reference herein to any specific commer- |
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| cial products, process, or service by trade name, trademark, |
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| manufacturer, or otherwise, does not necessarily constitute or |
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| imply its endorsement, recommendation, or favoring by the United |
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| States Government or the University of California. The views and |
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| opinions of authors expressed herein do not necessarily state or |
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| reflect those of the United States Government or the University |
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| of California, and shall not be used for advertising or product |
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\ endorsement purposes. /
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---------------------------------------------------------------------
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*/
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/*
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Floating point exception control module.
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This Python module provides bare-bones control over floating point
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units from several hardware manufacturers. Specifically, it allows
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the user to turn on the generation of SIGFPE whenever any of the
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three serious IEEE 754 exceptions (Division by Zero, Overflow,
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Invalid Operation) occurs. We currently ignore Underflow and
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Inexact Result exceptions, although those could certainly be added
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if desired.
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The module also establishes a signal handler for SIGFPE during
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initialization. This builds on code found in the Python
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distribution at Include/pyfpe.h and Python/pyfpe.c. If those files
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are not in your Python distribution, find them in a patch at
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ftp://icf.llnl.gov/pub/python/busby/patches.961108.tgz.
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This module is only useful to you if it happens to include code
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specific for your hardware and software environment. If you can
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contribute OS-specific code for new platforms, or corrections for
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the code provided, it will be greatly appreciated.
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** Version 1.0: September 20, 1996. Lee Busby, LLNL.
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include "Python.h"
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#include <signal.h>
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#ifndef WANT_SIGFPE_HANDLER
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/* Define locally if they are not defined in Python. This gives only
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* the limited control to induce a core dump in case of an exception.
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*/
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static jmp_buf PyFPE_jbuf;
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static int PyFPE_counter = 0;
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#endif
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typedef RETSIGTYPE Sigfunc(int);
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static Sigfunc sigfpe_handler;
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static void fpe_reset(Sigfunc *);
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static PyObject *fpe_error;
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void initfpectl(void);
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static PyObject *turnon_sigfpe (PyObject *self,PyObject *args);
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static PyObject *turnoff_sigfpe (PyObject *self,PyObject *args);
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static PyMethodDef fpectl_methods[] = {
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{"turnon_sigfpe", (PyCFunction) turnon_sigfpe, 1},
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{"turnoff_sigfpe", (PyCFunction) turnoff_sigfpe, 1},
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{0,0}
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};
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static PyObject *turnon_sigfpe(PyObject *self,PyObject *args)
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{
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/* Do any architecture-specific one-time only initialization here. */
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fpe_reset(sigfpe_handler);
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Py_INCREF (Py_None);
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return Py_None;
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}
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static void fpe_reset(Sigfunc *handler)
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{
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/* Reset the exception handling machinery, and reset the signal
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* handler for SIGFPE to the given handler.
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*/
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/*-- IRIX -----------------------------------------------------------------*/
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#if defined(sgi)
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/* See man page on handle_sigfpes -- must link with -lfpe
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* My usage doesn't follow the man page exactly. Maybe somebody
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* else can explain handle_sigfpes to me....
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* cc -c -I/usr/local/python/include fpectlmodule.c
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* ld -shared -o fpectlmodule.so fpectlmodule.o -lfpe
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*/
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#include <sigfpe.h>
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typedef void user_routine (unsigned[5], int[2]);
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typedef void abort_routine (unsigned long);
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handle_sigfpes(_OFF, 0,
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(user_routine *)0,
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_TURN_OFF_HANDLER_ON_ERROR,
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(abort_routine*)0);
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handle_sigfpes(_ON, _EN_OVERFL | _EN_DIVZERO | _EN_INVALID,
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(user_routine *)0,
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_ABORT_ON_ERROR,
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(abort_routine*)0);
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signal(SIGFPE, handler);
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/*-- SunOS and Solaris ----------------------------------------------------*/
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#elif defined(sun)
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/* References: ieee_handler, ieee_sun, ieee_functions, and ieee_flags
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man pages (SunOS or Solaris)
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cc -c -I/usr/local/python/include fpectlmodule.c
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ld -G -o fpectlmodule.so -L/opt/SUNWspro/lib fpectlmodule.o -lsunmath -lm
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*/
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#include <math.h>
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char *mode="exception", *in="all", *out;
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(void) nonstandard_arithmetic();
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(void) ieee_flags("clearall",mode,in,&out);
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(void) ieee_handler("set","common",(sigfpe_handler_type)handler);
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signal(SIGFPE, handler);
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/*-- HPUX -----------------------------------------------------------------*/
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#elif defined(__hppa) || defined(hppa)
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/* References: fpsetmask man page */
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/* cc -Aa +z -c -I/usr/local/python/include fpectlmodule.c */
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/* ld -b -o fpectlmodule.sl fpectlmodule.o -lm */
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#include <math.h>
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fpsetdefaults();
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signal(SIGFPE, handler);
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/*-- IBM AIX --------------------------------------------------------------*/
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#elif defined(__AIX) || defined(_AIX)
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/* References: fp_trap, fp_enable man pages */
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#include <fptrap.h>
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fp_trap(FP_TRAP_SYNC);
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fp_enable(TRP_INVALID | TRP_DIV_BY_ZERO | TRP_OVERFLOW);
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signal(SIGFPE, handler);
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/*-- DEC ALPHA OSF --------------------------------------------------------*/
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#elif defined(__alpha)
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/* References: exception_intro, ieee man pages */
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/* cc -c -I/usr/local/python/include fpectlmodule.c */
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/* ld -shared -o fpectlmodule.so fpectlmodule.o */
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#include <machine/fpu.h>
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unsigned long fp_control =
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IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE | IEEE_TRAP_ENABLE_OVF;
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ieee_set_fp_control(fp_control);
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signal(SIGFPE, handler);
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/*-- Cray Unicos ----------------------------------------------------------*/
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#elif defined(cray)
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/* UNICOS delivers SIGFPE by default, but no matherr */
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#ifdef HAS_LIBMSET
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libmset(-1);
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#endif
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signal(SIGFPE, handler);
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/*-- Linux ----------------------------------------------------------------*/
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#elif defined(linux)
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/* Linux delivers SIGFPE by default,
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except for log(0), atanh(-1), 0.^0.
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*/
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signal(SIGFPE, handler);
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/*-- NeXT -----------------------------------------------------------------*/
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#elif defined(NeXT) && defined(m68k) && defined(__GNUC__)
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/* NeXT needs explicit csr set to generate SIGFPE */
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asm("fmovel #0x1400,fpcr"); /* set OVFL and ZD bits */
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signal(SIGFPE, handler);
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/*-- Microsoft Windows, NT ------------------------------------------------*/
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#elif defined(_MSC_VER)
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/* Reference: Visual C++ Books Online 4.2,
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Run-Time Library Reference, _control87, _controlfp */
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#include <float.h>
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unsigned int cw = _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW;
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(void)_controlfp(0, cw);
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signal(SIGFPE, handler);
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/*-- Give Up --------------------------------------------------------------*/
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#else
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fputs("Operation not implemented\n", stderr);
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#endif
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}
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static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args)
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{
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fputs("Operation not implemented\n", stderr);
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Py_INCREF (Py_None);
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return Py_None;
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}
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static void sigfpe_handler(int signo)
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{
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fpe_reset(sigfpe_handler);
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if(PyFPE_counter) {
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longjmp(PyFPE_jbuf, 1);
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} else {
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Py_FatalError("Unprotected floating point exception");
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}
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}
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void initfpectl(void)
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{
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PyObject *m, *d;
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static int already_initialized = 0;
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if (already_initialized) return;
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m = Py_InitModule("fpectl", fpectl_methods);
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d = PyModule_GetDict(m);
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fpe_error = PyString_FromString("fpectl.error");
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PyDict_SetItemString(d, "error", fpe_error);
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if (PyErr_Occurred())
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Py_FatalError("Cannot initialize module fpectl");
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already_initialized = 1;
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}
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#ifdef __cplusplus
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}
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#endif
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