Signed Integer Overflow Detection A similar method can be developed for summation of signed long arrays. When adding signed integers, arithmetic overflow is possible. In fact, arithmetic underflow is also possible – where adding two negatives results in a positive value. When adding two signed integers, four cases are possible: both positive both negative first […]

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In the blog “Faster Checked Addition in C#” we saw how to add numbers safely in C# without using the checked key work and without exceptions. This raised performance, since exceptions have quite a bit of overhead. In this blog, I’ll extend this idea to the data parallel SIMD/SSE instructions of Intel and AMD processors, […]

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Several improvements to C# .Sum() were shown in the “Better C# .Sum() in Many Ways” blog and made available in the HPCsharp nuget package. In this blog, I’ll explore more ways to improve .Sum() to raise its capabilities to the next level in performance while not giving up accuracy. BigInteger Summation C# provides a BigInteger […]

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One of my pet peeves is not using hardware to its fullest ability, such as all of memory bandwidth available. Copying is one of the simplest operations, which is memory bandwidth bound, and should use most of memory bandwidth. In this blog, I’ll examine C# copy operations from List to Array, to see how fast […]

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Adding Two Integers – Surprise! Adding two integers in C# can produce surprising results. For instance, int sum = 2147483647;    // Int32.MaxValue == 0x7FFFFFFF sum = sum + 1; The resulting sum is expected to be 2147483648, but is -2147483648 instead. uint sum = 4294967295;    // UInt32.MaxValue == 0xFFFFFFFF sum = sum + 1; The […]

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C# Linq provides a convenient way to add up all of the array elements. var arr = new int[] { 5, 7, 16, 3 }; int arrSum = arr.Sum(); This .Sum() supports some of the built-in numeric types: int, long, float, double, and decimal. It provides a nicely consistent and convenient way of adding up […]

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In this blog I’ll assemble variety of resources for code performance optimization – from videos to blog posts to StackOverflow topics to university class instructions to books. I’ll update this post from time to time. Videos   Books Blogs Gallery of Processor Cache Effects  

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LSD Radix Sort algorithm has been around for a long time with first computer usage in 1950’s and 1960’s to sort punch cards by performing several passes at the stack of cards. It has resurfaced in the last decade with GPUs having hundreds and even thousands of processor with internal local truly random access memories […]

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