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<h3 class="section">A.3 Handling floating point exceptions</h3>
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<p>It is possible to stop the program whenever a <code>SIGFPE</code> floating
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point exception occurs. This can be useful for finding the cause of an
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unexpected infinity or <code>NaN</code>. The current handler settings can be
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shown with the command <code>info signal SIGFPE</code>.
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<pre class="smallexample"> (gdb) info signal SIGFPE
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Signal Stop Print Pass to program Description
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SIGFPE Yes Yes Yes Arithmetic exception
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<p class="noindent">Unless the program uses a signal handler the default setting should be
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changed so that SIGFPE is not passed to the program, as this would cause
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it to exit. The command <code>handle SIGFPE stop nopass</code> prevents this.
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<pre class="smallexample"> (gdb) handle SIGFPE stop nopass
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Signal Stop Print Pass to program Description
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SIGFPE Yes Yes No Arithmetic exception
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<p class="noindent">Depending on the platform it may be necessary to instruct the kernel to
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generate signals for floating point exceptions. For programs using GSL
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this can be achieved using the <code>GSL_IEEE_MODE</code> environment variable
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in conjunction with the function <code>gsl_ieee_env_setup()</code> as described
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in see <a href="IEEE-floating_002dpoint-arithmetic.html#IEEE-floating_002dpoint-arithmetic">IEEE floating-point arithmetic</a>.
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<pre class="example"> (gdb) set env GSL_IEEE_MODE=double-precision
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