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POGCC: program doesn't work with compilation option -O3
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  1. POGCC: program doesn't work with compilation option -O3
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    copied!<p>I'm writing a C++ program that doesn't work (I get a segmentation fault) when I compile it with optimizations (options -O1, -O2, -O3, etc.), but it works just fine when I compile it without optimizations.</p> <p>Is there any chance that the error is in my code? or should I assume that this is a bug in GCC?</p> <p>My GCC version is 3.4.6.</p> <p>Is there any known workaround for this kind of problem?</p> <p>There is a big difference in speed between the optimized and unoptimized version of my program, so I really need to use optimizations.</p> <hr> <p>This is my original functor. The one that works fine with no levels of optimizations and throws a segmentation fault with any level of optimization:</p> <pre><code>struct distanceToPointSort{ indexedDocument* point ; distanceToPointSort(indexedDocument* p): point(p) {} bool operator() (indexedDocument* p1,indexedDocument* p2){ return distance(point,p1) &lt; distance(point,p2) ; } } ; </code></pre> <p>And this one works flawlessly with any level of optimization:</p> <pre><code>struct distanceToPointSort{ indexedDocument* point ; distanceToPointSort(indexedDocument* p): point(p) {} bool operator() (indexedDocument* p1,indexedDocument* p2){ float d1=distance(point,p1) ; float d2=distance(point,p2) ; std::cout &lt;&lt; "" ; //without this line, I get a segmentation fault anyways return d1 &lt; d2 ; } } ; </code></pre> <p>Unfortunately, this problem is hard to reproduce because it happens with some specific values. I get the segmentation fault upon sorting just one out of more than a thousand vectors, so it really depends on the specific combination of values each vector has.</p>
 

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