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1 /* |
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2 --------------------------------------------------------------------- |
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3 / Copyright (c) 1996. \ |
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4 | The Regents of the University of California. | |
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5 | All rights reserved. | |
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6 | | |
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7 | Permission to use, copy, modify, and distribute this software for | |
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8 | any purpose without fee is hereby granted, provided that this en- | |
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9 | tire notice is included in all copies of any software which is or | |
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10 | includes a copy or modification of this software and in all | |
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11 | copies of the supporting documentation for such software. | |
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12 | | |
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13 | This work was produced at the University of California, Lawrence | |
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14 | Livermore National Laboratory under contract no. W-7405-ENG-48 | |
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15 | between the U.S. Department of Energy and The Regents of the | |
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16 | University of California for the operation of UC LLNL. | |
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17 | | |
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18 | DISCLAIMER | |
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19 | | |
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20 | This software was prepared as an account of work sponsored by an | |
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21 | agency of the United States Government. Neither the United States | |
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22 | Government nor the University of California nor any of their em- | |
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23 | ployees, makes any warranty, express or implied, or assumes any | |
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24 | liability or responsibility for the accuracy, completeness, or | |
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25 | usefulness of any information, apparatus, product, or process | |
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26 | disclosed, or represents that its use would not infringe | |
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27 | privately-owned rights. Reference herein to any specific commer- | |
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28 | cial products, process, or service by trade name, trademark, | |
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29 | manufacturer, or otherwise, does not necessarily constitute or | |
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30 | imply its endorsement, recommendation, or favoring by the United | |
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31 | States Government or the University of California. The views and | |
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32 | opinions of authors expressed herein do not necessarily state or | |
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33 | reflect those of the United States Government or the University | |
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34 | of California, and shall not be used for advertising or product | |
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35 \ endorsement purposes. / |
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36 --------------------------------------------------------------------- |
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37 */ |
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38 |
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39 /* |
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40 Floating point exception control module. |
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41 |
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42 This Python module provides bare-bones control over floating point |
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43 units from several hardware manufacturers. Specifically, it allows |
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44 the user to turn on the generation of SIGFPE whenever any of the |
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45 three serious IEEE 754 exceptions (Division by Zero, Overflow, |
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46 Invalid Operation) occurs. We currently ignore Underflow and |
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47 Inexact Result exceptions, although those could certainly be added |
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48 if desired. |
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49 |
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50 The module also establishes a signal handler for SIGFPE during |
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51 initialization. This builds on code found in the Python |
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52 distribution at Include/pyfpe.h and Python/pyfpe.c. If those files |
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53 are not in your Python distribution, find them in a patch at |
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54 ftp://icf.llnl.gov/pub/python/busby/patches.961108.tgz. |
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55 |
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56 This module is only useful to you if it happens to include code |
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57 specific for your hardware and software environment. If you can |
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58 contribute OS-specific code for new platforms, or corrections for |
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59 the code provided, it will be greatly appreciated. |
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60 |
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61 ** Version 1.0: September 20, 1996. Lee Busby, LLNL. |
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62 */ |
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63 |
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64 #ifdef __cplusplus |
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65 extern "C" { |
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66 #endif |
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67 |
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68 #include "Python.h" |
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69 #include <signal.h> |
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70 |
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71 #if defined(__FreeBSD__) |
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72 # include <ieeefp.h> |
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73 #elif defined(__VMS) |
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74 #define __NEW_STARLET |
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75 #include <starlet.h> |
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76 #include <ieeedef.h> |
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77 #endif |
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78 |
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79 #ifndef WANT_SIGFPE_HANDLER |
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80 /* Define locally if they are not defined in Python. This gives only |
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81 * the limited control to induce a core dump in case of an exception. |
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82 */ |
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83 #include <setjmp.h> |
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84 static jmp_buf PyFPE_jbuf; |
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85 static int PyFPE_counter = 0; |
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86 #endif |
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87 |
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88 typedef void Sigfunc(int); |
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89 static Sigfunc sigfpe_handler; |
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90 static void fpe_reset(Sigfunc *); |
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91 |
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92 static PyObject *fpe_error; |
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93 PyMODINIT_FUNC initfpectl(void); |
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94 static PyObject *turnon_sigfpe (PyObject *self,PyObject *args); |
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95 static PyObject *turnoff_sigfpe (PyObject *self,PyObject *args); |
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96 |
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97 static PyMethodDef fpectl_methods[] = { |
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98 {"turnon_sigfpe", (PyCFunction) turnon_sigfpe, METH_VARARGS}, |
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99 {"turnoff_sigfpe", (PyCFunction) turnoff_sigfpe, METH_VARARGS}, |
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100 {0,0} |
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101 }; |
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102 |
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103 static PyObject *turnon_sigfpe(PyObject *self,PyObject *args) |
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104 { |
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105 /* Do any architecture-specific one-time only initialization here. */ |
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106 |
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107 fpe_reset(sigfpe_handler); |
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108 Py_INCREF (Py_None); |
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109 return Py_None; |
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110 } |
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111 |
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112 static void fpe_reset(Sigfunc *handler) |
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113 { |
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114 /* Reset the exception handling machinery, and reset the signal |
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115 * handler for SIGFPE to the given handler. |
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116 */ |
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117 |
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118 /*-- IRIX -----------------------------------------------------------------*/ |
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119 #if defined(sgi) |
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120 /* See man page on handle_sigfpes -- must link with -lfpe |
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121 * My usage doesn't follow the man page exactly. Maybe somebody |
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122 * else can explain handle_sigfpes to me.... |
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123 * cc -c -I/usr/local/python/include fpectlmodule.c |
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124 * ld -shared -o fpectlmodule.so fpectlmodule.o -lfpe |
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125 */ |
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126 #include <sigfpe.h> |
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127 typedef void user_routine (unsigned[5], int[2]); |
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128 typedef void abort_routine (unsigned long); |
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129 handle_sigfpes(_OFF, 0, |
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130 (user_routine *)0, |
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131 _TURN_OFF_HANDLER_ON_ERROR, |
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132 NULL); |
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133 handle_sigfpes(_ON, _EN_OVERFL | _EN_DIVZERO | _EN_INVALID, |
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134 (user_routine *)0, |
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135 _ABORT_ON_ERROR, |
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136 NULL); |
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137 PyOS_setsig(SIGFPE, handler); |
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138 |
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139 /*-- SunOS and Solaris ----------------------------------------------------*/ |
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140 #elif defined(sun) |
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141 /* References: ieee_handler, ieee_sun, ieee_functions, and ieee_flags |
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142 man pages (SunOS or Solaris) |
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143 cc -c -I/usr/local/python/include fpectlmodule.c |
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144 ld -G -o fpectlmodule.so -L/opt/SUNWspro/lib fpectlmodule.o -lsunmath -lm |
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145 */ |
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146 #include <math.h> |
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147 #ifndef _SUNMATH_H |
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148 extern void nonstandard_arithmetic(void); |
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149 extern int ieee_flags(const char*, const char*, const char*, char **); |
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150 extern long ieee_handler(const char*, const char*, sigfpe_handler_type); |
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151 #endif |
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152 |
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153 char *mode="exception", *in="all", *out; |
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154 (void) nonstandard_arithmetic(); |
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155 (void) ieee_flags("clearall",mode,in,&out); |
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156 (void) ieee_handler("set","common",(sigfpe_handler_type)handler); |
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157 PyOS_setsig(SIGFPE, handler); |
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158 |
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159 /*-- HPUX -----------------------------------------------------------------*/ |
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160 #elif defined(__hppa) || defined(hppa) |
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161 /* References: fpsetmask man page */ |
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162 /* cc -Aa +z -c -I/usr/local/python/include fpectlmodule.c */ |
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163 /* ld -b -o fpectlmodule.sl fpectlmodule.o -lm */ |
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164 #include <math.h> |
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165 fpsetdefaults(); |
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166 PyOS_setsig(SIGFPE, handler); |
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167 |
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168 /*-- IBM AIX --------------------------------------------------------------*/ |
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169 #elif defined(__AIX) || defined(_AIX) |
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170 /* References: fp_trap, fp_enable man pages */ |
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171 #include <fptrap.h> |
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172 fp_trap(FP_TRAP_SYNC); |
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173 fp_enable(TRP_INVALID | TRP_DIV_BY_ZERO | TRP_OVERFLOW); |
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174 PyOS_setsig(SIGFPE, handler); |
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175 |
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176 /*-- DEC ALPHA OSF --------------------------------------------------------*/ |
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177 #elif defined(__alpha) && defined(__osf__) |
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178 /* References: exception_intro, ieee man pages */ |
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179 /* cc -c -I/usr/local/python/include fpectlmodule.c */ |
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180 /* ld -shared -o fpectlmodule.so fpectlmodule.o */ |
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181 #include <machine/fpu.h> |
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182 unsigned long fp_control = |
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183 IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE | IEEE_TRAP_ENABLE_OVF; |
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184 ieee_set_fp_control(fp_control); |
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185 PyOS_setsig(SIGFPE, handler); |
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186 |
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187 /*-- DEC ALPHA LINUX ------------------------------------------------------*/ |
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188 #elif defined(__alpha) && defined(linux) |
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189 #include <asm/fpu.h> |
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190 unsigned long fp_control = |
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191 IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE | IEEE_TRAP_ENABLE_OVF; |
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192 ieee_set_fp_control(fp_control); |
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193 PyOS_setsig(SIGFPE, handler); |
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194 |
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195 /*-- DEC ALPHA VMS --------------------------------------------------------*/ |
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196 #elif defined(__ALPHA) && defined(__VMS) |
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197 IEEE clrmsk; |
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198 IEEE setmsk; |
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199 clrmsk.ieee$q_flags = |
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200 IEEE$M_TRAP_ENABLE_UNF | IEEE$M_TRAP_ENABLE_INE | |
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201 IEEE$M_MAP_UMZ; |
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202 setmsk.ieee$q_flags = |
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203 IEEE$M_TRAP_ENABLE_INV | IEEE$M_TRAP_ENABLE_DZE | |
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204 IEEE$M_TRAP_ENABLE_OVF; |
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205 sys$ieee_set_fp_control(&clrmsk, &setmsk, 0); |
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206 PyOS_setsig(SIGFPE, handler); |
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207 |
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208 /*-- HP IA64 VMS --------------------------------------------------------*/ |
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209 #elif defined(__ia64) && defined(__VMS) |
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210 PyOS_setsig(SIGFPE, handler); |
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211 |
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212 /*-- Cray Unicos ----------------------------------------------------------*/ |
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213 #elif defined(cray) |
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214 /* UNICOS delivers SIGFPE by default, but no matherr */ |
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215 #ifdef HAS_LIBMSET |
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216 libmset(-1); |
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217 #endif |
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218 PyOS_setsig(SIGFPE, handler); |
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219 |
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220 /*-- FreeBSD ----------------------------------------------------------------*/ |
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221 #elif defined(__FreeBSD__) |
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222 fpresetsticky(fpgetsticky()); |
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223 fpsetmask(FP_X_INV | FP_X_DZ | FP_X_OFL); |
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224 PyOS_setsig(SIGFPE, handler); |
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225 |
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226 /*-- Linux ----------------------------------------------------------------*/ |
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227 #elif defined(linux) |
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228 #ifdef __GLIBC__ |
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229 #include <fpu_control.h> |
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230 #else |
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231 #include <i386/fpu_control.h> |
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232 #endif |
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233 #ifdef _FPU_SETCW |
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234 { |
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235 fpu_control_t cw = 0x1372; |
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236 _FPU_SETCW(cw); |
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237 } |
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238 #else |
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239 __setfpucw(0x1372); |
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240 #endif |
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241 PyOS_setsig(SIGFPE, handler); |
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242 |
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243 /*-- Microsoft Windows, NT ------------------------------------------------*/ |
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244 #elif defined(_MSC_VER) |
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245 /* Reference: Visual C++ Books Online 4.2, |
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246 Run-Time Library Reference, _control87, _controlfp */ |
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247 #include <float.h> |
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248 unsigned int cw = _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW; |
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249 (void)_controlfp(0, cw); |
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250 PyOS_setsig(SIGFPE, handler); |
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251 |
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252 /*-- Give Up --------------------------------------------------------------*/ |
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253 #else |
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254 fputs("Operation not implemented\n", stderr); |
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255 #endif |
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256 |
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257 } |
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258 |
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259 static PyObject *turnoff_sigfpe(PyObject *self,PyObject *args) |
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260 { |
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261 #ifdef __FreeBSD__ |
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262 fpresetsticky(fpgetsticky()); |
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263 fpsetmask(0); |
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264 #elif defined(__VMS) |
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265 IEEE clrmsk; |
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266 clrmsk.ieee$q_flags = |
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267 IEEE$M_TRAP_ENABLE_UNF | IEEE$M_TRAP_ENABLE_INE | |
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268 IEEE$M_MAP_UMZ | IEEE$M_TRAP_ENABLE_INV | |
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269 IEEE$M_TRAP_ENABLE_DZE | IEEE$M_TRAP_ENABLE_OVF | |
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270 IEEE$M_INHERIT; |
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271 sys$ieee_set_fp_control(&clrmsk, 0, 0); |
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272 #else |
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273 fputs("Operation not implemented\n", stderr); |
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274 #endif |
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275 Py_INCREF(Py_None); |
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276 return Py_None; |
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277 } |
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278 |
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279 static void sigfpe_handler(int signo) |
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280 { |
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281 fpe_reset(sigfpe_handler); |
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282 if(PyFPE_counter) { |
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283 longjmp(PyFPE_jbuf, 1); |
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284 } else { |
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285 Py_FatalError("Unprotected floating point exception"); |
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286 } |
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287 } |
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288 |
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289 PyMODINIT_FUNC initfpectl(void) |
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290 { |
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291 PyObject *m, *d; |
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292 m = Py_InitModule("fpectl", fpectl_methods); |
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293 if (m == NULL) |
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294 return; |
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295 d = PyModule_GetDict(m); |
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296 fpe_error = PyErr_NewException("fpectl.error", NULL, NULL); |
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297 if (fpe_error != NULL) |
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298 PyDict_SetItemString(d, "error", fpe_error); |
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299 } |
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300 |
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301 #ifdef __cplusplus |
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302 } |
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303 #endif |