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POSegmentation fault in a simple C++ program
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  1. POSegmentation fault in a simple C++ program
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    copied!<p>The program gives me a <a href="http://en.wikipedia.org/wiki/Segmentation_fault" rel="nofollow">segmentation fault</a>. How can I fix this problem?</p> <p>I have a <code>makefile</code>, <code>fir_filter.cpp</code>, <code>fir_filter_mod.cpp</code>, <code>fir_filter.h</code>, <code>fir_filter_mod.h</code> and <code>testbench.cpp</code>. Basically I use testbench to check the result between <code>fir_filter.cpp</code> and <code>fir_filter_mod.cpp</code>.</p> <h3>File Makefile:</h3> <pre><code>CAT_HOME = $(MGC_HOME) TARGET = my_tb OBJECTS = fir_filter.o fir_filter_mod.o testbench.o DEPENDS = fir_filter.h fir_filter_mod.h INCLUDES = -I"$(CAT_HOME)/shared/include" DEFINES = CXX = /usr/bin/g++ CXXFLAGS = -g $(DEFINES) $(INCLUDES) $(TARGET) : $(OBJECTS) $(CXX) $(CXXFLAGS) -o $(TARGET) $(OBJECTS) $(OBJECTS) : $(DEPENDS) # Phony target to remove all objects and executables .PHONY: clean clean: rm -f *.o my_tb </code></pre> <h3>File shift_class.h</h3> <pre><code>#ifndef __SHIFT_CLASS__ #define __SHIFT_CLASS__ template&lt;typename dataType, int NUM_REGS&gt; class shift_class{ private: dataType regs[NUM_REGS]; bool en; bool sync_rst; bool ld; dataType *load_data; public: shift_class(): en(true), sync_rst(false), ld(false) {} shift_class(dataType din[NUM_REGS]): en(true), sync_rst(false), ld(false) { load_data = din; } void set_sync_rst(bool srst) { sync_rst = srst; } void load(bool load_in){ ld = load_in; } void set_enable(bool enable) { en = enable; } void operator &lt;&lt; (dataType din){ SHIFT: for(int i = NUM_REGS - 1; i &gt;= 0; i--) { if(en) if(sync_rst) regs[i] = 0; else if(ld) regs[i] = load_data[i]; else if(i == 0) regs[i] = din; else regs[i] = regs[i - 1]; } } dataType operator [] (int i){ return regs[i]; } }; #endif </code></pre> <h3>File fir_filter.h</h3> <pre><code>void fir_filter(double *x, double *y); </code></pre> <h3>File fir_filter.cpp</h3> <pre><code>#include "fir_filter.h" #include "shift_class.h" void fir_filter(double *x, double *y) { const double h[4] = {0.5, 0.5, 0.5, 0.5}; static shift_class&lt;double, 4&gt; regs; double temp = 0; regs &lt;&lt; *x; MAX: for(int i = 0; i &lt; 4; i++) { temp += h[i] * regs[i]; } *y = temp; } </code></pre> <h3>File fir_filter_mod.cpp</h3> <pre><code>#include "fir_filter_mod.h" #include "shift_class.h" double fir_filter_mod(double *x) { const double h[4] = {0.5, 0.5, 0.5, 0.5}; static shift_class&lt;double, 4&gt; regs; double y = 0; double temp = 0; regs &lt;&lt; *x; MAX: for(int i = 0; i &lt; 4; i++) { temp += h[i] * regs[i]; } y = temp; return y; } </code></pre> <h3>File fir_filter.h</h3> <pre><code>double fir_filter_mod(double *x); </code></pre> <h3>File testbench.cpp</h3> <pre><code>#include &lt;iostream&gt; #include "fir_filter.h" #include "fir_filter_mod.h" using namespace std; int main() { double *x; double *y; double y_mod; double init = 1; x = &amp;init; for(int j = 0; j &lt; 5; j++) { fir_filter(x, y); y_mod = fir_filter_mod(x); if(*y == y_mod) { cout &lt;&lt; "ERROR" &lt;&lt; endl; } else { cout &lt;&lt; y_mod &lt;&lt; endl; } } } </code></pre>
 

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