Python 3.15’s interpreter for Windows x86-64 should hopefully be 15% faster
Ken Jin Python 3.15’s interpreter for Windows x86-64 should hopefully be 15% faster 24 December 2025 Some time ago I posted an apology peice for Python’s tail caling results. I apologized for communicating performance results without noticing a compiler bug had occured. I can proudly say today that I am partially retracting that apology, but only for two platforms—MacOs AArch64 (XCode Clang) and Windows x86-64 (MSVC). In our own experiments, the tail calling interpreter for CPython was found to beat the computed goto interpreter by 5% on pyperformance on AArch64 macOS using XCode Clang, and roughly 15% on pyperformance on Windows on an experimental internal version of MSVC. The Windows build is against a switch-case interpreter, but this in theory shouldn’t matter too much, more…
