<p>I implement convolution with fft and block.<br>
When input and kernel scale is large, fft performs much better than simple loop convolution.<br>
But in my experiment simple loop convolution performs better than block convolution.<br>
As my convolution type is different from <a href="http://lists.r-forge.r-project.org/pipermail/rcpp-devel/2012-January/003304.html">http://lists.r-forge.r-project.org/pipermail/rcpp-devel/2012-January/003304.html</a>, so the block convolution is also different.<br>
My configuration:<br>
cmake -D DEBUG=OFF -G "Xcode"<br>
In Xcode in use Release Mode to do comparasion</p>

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