High-Performance Binary Search
Optimized binary search algorithms can be up to four times faster than std::lower_bound by eliminating branching and improving memory layout, enhancing cache performance and data locality for specific contexts.
Read original articleThe article discusses optimizations for the binary search algorithm, highlighting two variants that can be significantly faster than the standard implementation found in libraries like std::lower_bound. The first variant eliminates branching, which is a common bottleneck in performance due to control hazards and data hazards. By using predication, the algorithm can avoid conditional jumps, leading to improved performance, especially on smaller arrays. The second variant focuses on optimizing memory layout to enhance cache performance, utilizing a specific arrangement known as the Eytzinger layout, which groups frequently accessed elements together. This layout improves data locality, reducing cache misses and improving overall search speed. The article emphasizes that while these optimizations can yield substantial performance gains, they may not be universally applicable and should be tested in specific contexts. The performance improvements are quantified, showing that the optimized versions can be up to four times faster than the standard implementation, depending on the size of the data set.
- Optimized binary search can be up to 4x faster than std::lower_bound.
- Branchless implementation reduces control hazards and improves performance.
- Memory layout optimization enhances cache performance through better data locality.
- Eytzinger layout groups frequently accessed elements to minimize cache misses.
- Performance gains vary based on array size and specific use cases.
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