An interesting trick for increasing instruction-level parallelism by introducing a spurious-seeming conditional to break a dependency chain:

If we could tell the CPU to predict that j stays intact, the loop would become throughput-bound rather than latency-bound. While we don’t have direct control over address prediction, we can simulate this with branch prediction: […]

See also Matt Godbolt’s talk about the fundamental performance features of modern CPUs.

An interactive tool for seeing how various compilers (GCC, Clang, MSVC, rustc, etc.) produce machine code for various architectures at various optimisation levels.

A very good talk about the fundamentals of high-performance CPUs, plus tooling for experimenting with and measuring low-level performance characteristics, from Matt Godbolt, who also runs the Compiler Explorer.

Presented at GOTO Chicago 2024.

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