Counting Words at SIMD Speed
11 days ago
- #SIMD
- #optimization
- #performance
- The article discusses optimizing word counting in text files, starting with Python and moving to C and SIMD programming for speed.
- Initial Python implementation is slow (89.6 seconds) due to interpreter overhead per byte.
- Using CPython's `re` module reduces time to 13.7 seconds by leveraging C extensions.
- A C implementation further speeds up the process to 1.205 seconds by avoiding Python overhead.
- SIMD (Single Instruction, Multiple Data) programming in C with ARM NEON reduces time to 249 milliseconds by processing 16-byte chunks in parallel.
- Adding multi-threading to the SIMD approach achieves 181 milliseconds, nearing memory bandwidth limits.
- Final optimizations show the threaded SIMD version is ~494 times faster than the initial Python version.
- The author provides source files and benchmarks, inviting feedback on potential missed optimizations.