Easton Man's Channel

Copying data in software is cheap, but it is not at all free. As you start optimizing your code, you might find that copies become a performance bottleneck. Let me be clear that copies really are cheap. It is often more performant to copy that data than to track the same memory across different threads. The case I am interested in is when copies turn a trivial operation into one that is relatively expensive. Recently, the fast JavaScript runtime (Bun) optimized its base64 decoding routines.Base64 is a technique…

Server CPUs have pushed high core counts for a long time, though they way they got high core counts has varied. Bergamo is AMD’s move to increase core counts beyond what scaling up an interconnect can do, by using density focused Zen 4c cores. It’s a strategy with parallels to Intel’s upcoming Sierra Forest and Ampere’s server CPUs. Ampere in particular has shown there’s a market for server chips that prioritize core count, especially with cloud providers that rent compute capacity by the core. More cores lets…

We have been working on a fast library to validate and transcode Unicode and other formats such as base64 in C++: simdutf. We wondered: could we achieve the same good results in C#? Microsoft’s .NET framework has made great strides in leveraging advanced instructions. For instance, if your processor supports AVX-512, you can instantiate 512-bit registers right in C#! The standard .NET runtime library effectively utilizes these features, demonstrating that they practice what they preach. Most strings on the…

Modern processors have instructions to process several bytes at once. Effectively all processors have the capability of processing 16 bytes one once. These instructions are called SIMD, for single instruction, multiple data. It was once an open question whether these instructions could be useful to accelerate common tasks such as parsing HTML or JSON. However, the work on JSON parsing, as in the simdjson parser, has shown rather decisively that SIMD instructions could, indeed, be helpful in breaking speed records.…