* Builds using Visual Studio 2026 (MSVC 18) may now use the new
:ref:`tail-calling interpreter <whatsnew314-tail-call-interpreter>`.
- Results on an early experimental MSVC compiler reported roughly 15% speedup
- on the geometric mean of pyperformance on Windows x86-64 over
- the switch-case interpreter. We have
- observed speedups ranging from 15% for large pure-Python libraries
+ Results on Visual Studio 18.1.1 report between
+ `15-20% <https://github.com/faster-cpython/ideas/blob/main/results/5800X-msvc.pgo2-vs-msvc.pgo.tc.svg>`__
+ speedup on the geometric mean of pyperformance on Windows x86-64 over
+ the switch-case interpreter on an AMD Ryzen 7 5800X. We have
+ observed speedups ranging from 14% for large pure-Python libraries
to 40% for long-running small pure-Python scripts on Windows.
+ This was made possible by a new feature introduced in MSVC 18.
(Contributed by Chris Eibl, Ken Jin, and Brandt Bucher in :gh:`143068`.
Special thanks to the MSVC team including Hulon Jenkins.)