Performance of the Python 3.14 tail-call interpreter

Nelson Elhage · 9 Mar 2025 · blog.nelhage.com ↗

3 korrents from this piece

Nelson Elhage did not write this page.

Every claim below was made in this piece, quoted word for word and numbered in the order the piece makes them, so you can read it there rather than take our word for it. The sentence above each quote is our reading of the claim, not their wording. Each quote was checked against a stored copy of the page at build time; where the two differ, the quote is the fact.

Our reading
Impressive-looking benchmark improvements often result from comparing against a poorly-tuned baseline rather than a genuine advance.

Their wordsIt's easy to get impressive-looking results if you're comparing against a poorly-tuned baseline, and that observation turns out to explain a surprising fraction of supposed improvements.
Our reading
As software projects grow more numerous, fast-moving, and interdependent, cross-project regressions become practically inevitable.

Their wordsHowever, with so many different software projects out there, each moving so rapidly and depending on and being used by so many other projects, it becomes practically-inevitable that some regressions "like that one" happen, almost constantly.
Our reading
Compiler mechanisms that force a required optimization to occur, rather than relying on incidental compiler behavior, are a more robust way to write performance-sensitive code.

Their wordsI'm hopeful this framework will turn out to be a much more robust style for writing performance-sensitive code, especially over time and as compilers evolve.