This article doesn't do the best job explaining the broader picture - stability has been their number one priority up to this point.
- Most of the work has just been plumbing. Int/float unboxing, smarter register allocation, free-threaded safety land in 3.15+.
- Most JIT optimizations are currently off by default or only triggers after a few thousand hits, and skips any byte-codes that look risky (profiling hooks, rare ops, etc.).
Hi, author of the post here, stability indeed has been a priority. There are some points which are not exactly the case though:
- Most of the work has just been plumbing. Int/float unboxing, smarter register allocation, free-threaded safety land in 3.15+.
The first part is true, but for the second sentence: none of that is guaranteed to land in 3.15+. We proposed to land them, that doesn't mean they will. Landing a PR in CPython is subject to maintainer time and reviewer approval, which doesn't always happen. I proposed a few optimizations for 3.14 that never landed.
Most JIT optimizations are currently off by default or only triggers after a few thousand hits
It is indeed true we only trigger after a few thousand hits, but all optimizations that we currently have are always enabled. We don't sandbag the JIT on purpose.
Comments
This article doesn't do the best job explaining the broader picture - stability has been their number one priority up to this point.
- Most of the work has just been plumbing. Int/float unboxing, smarter register allocation, free-threaded safety land in 3.15+.
- Most JIT optimizations are currently off by default or only triggers after a few thousand hits, and skips any byte-codes that look risky (profiling hooks, rare ops, etc.).
I really recommend this talk with one of the Microsoft faster Cpython developers for more details, https://www.youtube.com/watch?v=abNY_RcO-BU
Hi, author of the post here, stability indeed has been a priority. There are some points which are not exactly the case though:
The first part is true, but for the second sentence: none of that is guaranteed to land in 3.15+. We proposed to land them, that doesn't mean they will. Landing a PR in CPython is subject to maintainer time and reviewer approval, which doesn't always happen. I proposed a few optimizations for 3.14 that never landed.
It is indeed true we only trigger after a few thousand hits, but all optimizations that we currently have are always enabled. We don't sandbag the JIT on purpose.