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			277 lines
		
	
	
	
		
			9.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			277 lines
		
	
	
	
		
			9.9 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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|    |                                                                       |
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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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|    |                                                                       |
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|    |                              DISCLAIMER                               |
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|    |                                                                       |
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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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| /*
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|                   Floating point exception control module.
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| 
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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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| 
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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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| 
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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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| 
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|    ** Version 1.0: September 20, 1996.  Lee Busby, LLNL.
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|  */
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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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| 
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| #include "Python.h"
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| #include <signal.h>
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| 
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| #if defined(__FreeBSD__)
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| #  include <ieeefp.h>
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| #endif
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| 
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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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| #include <setjmp.h>
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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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| 
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| typedef void Sigfunc(int);
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| static Sigfunc sigfpe_handler;
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| static void fpe_reset(Sigfunc *);
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| 
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| static PyObject *fpe_error;
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| 
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| PyMODINIT_FUNC PyInit_fpectl(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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| 
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| static PyMethodDef fpectl_methods[] = {
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|     {"turnon_sigfpe",            (PyCFunction) turnon_sigfpe,            METH_VARARGS},
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|     {"turnoff_sigfpe",           (PyCFunction) turnoff_sigfpe,           METH_VARARGS},
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|     {0,0}
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| };
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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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| 
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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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| 
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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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| 
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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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|                  NULL);
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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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|                  NULL);
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|     PyOS_setsig(SIGFPE, handler);
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| 
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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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| #ifndef _SUNMATH_H
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|     extern void nonstandard_arithmetic(void);
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|     extern int ieee_flags(const char*, const char*, const char*, char **);
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|     extern long ieee_handler(const char*, const char*, sigfpe_handler_type);
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| #endif
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| 
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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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|     PyOS_setsig(SIGFPE, handler);
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| 
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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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|     PyOS_setsig(SIGFPE, handler);
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| 
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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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|     PyOS_setsig(SIGFPE, handler);
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| 
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| /*-- DEC ALPHA LINUX ------------------------------------------------------*/
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| #elif defined(__alpha) && defined(linux)
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| #include <asm/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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|     PyOS_setsig(SIGFPE, handler);
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| 
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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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|     PyOS_setsig(SIGFPE, handler);
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| 
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| /*-- FreeBSD ----------------------------------------------------------------*/
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| #elif defined(__FreeBSD__)
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|     fpresetsticky(fpgetsticky());
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|     fpsetmask(FP_X_INV | FP_X_DZ | FP_X_OFL);
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|     PyOS_setsig(SIGFPE, handler);
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| 
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| /*-- Linux ----------------------------------------------------------------*/
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| #elif defined(linux)
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| #ifdef __GLIBC__
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| #include <fpu_control.h>
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| #else
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| #include <i386/fpu_control.h>
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| #endif
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| #ifdef _FPU_SETCW
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|     {
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|         fpu_control_t cw = 0x1372;
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|         _FPU_SETCW(cw);
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|     }
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| #else
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|     __setfpucw(0x1372);
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| #endif
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|     PyOS_setsig(SIGFPE, handler);
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| 
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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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|     PyOS_setsig(SIGFPE, handler);
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| 
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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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| }
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| 
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| static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args)
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| {
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| #ifdef __FreeBSD__
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|     fpresetsticky(fpgetsticky());
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|     fpsetmask(0);
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| #else
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|     fputs("Operation not implemented\n", stderr);
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| #endif
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|     Py_INCREF(Py_None);
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|     return Py_None;
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| }
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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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| 
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| static struct PyModuleDef fpectlmodule = {
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|         PyModuleDef_HEAD_INIT,
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|         "fpectl",
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|         NULL,
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|         -1,
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|         fpectl_methods,
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|         NULL,
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|         NULL,
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|         NULL,
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|         NULL
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| };
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| 
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| PyMODINIT_FUNC PyInit_fpectl(void)
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| {
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|     PyObject *m, *d;
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|     m = PyModule_Create(&fpectlmodule);
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|     if (m == NULL)
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|         return NULL;
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|     d = PyModule_GetDict(m);
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|     fpe_error = PyErr_NewException("fpectl.error", NULL, NULL);
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|     if (fpe_error != NULL)
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|         PyDict_SetItemString(d, "error", fpe_error);
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|     return m;
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| }
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| 
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| #ifdef __cplusplus
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| }
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| #endif
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