https://github.com/python/cpython/commit/2e64e36a2b1f8ebb2a6f24ad5c8f75388047d039 commit: 2e64e36a2b1f8ebb2a6f24ad5c8f75388047d039 branch: main author: Chris Eibl <[email protected]> committer: hugovk <[email protected]> date: 2026-03-27T13:44:25+02:00 summary:
GH-139922: update 3.15 whatsnew: Windows 64-bit binaries now use the tail-calling interpreter (#146391) Co-authored-by: Hugo van Kemenade <[email protected]> files: M Doc/whatsnew/3.15.rst diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst index a0475f778a372d..7d13eccb22311f 100644 --- a/Doc/whatsnew/3.15.rst +++ b/Doc/whatsnew/3.15.rst @@ -84,7 +84,8 @@ Summary -- Release highlights <whatsnew315-pybyteswriter>` * :ref:`The JIT compiler has been significantly upgraded <whatsnew315-jit>` * :ref:`Improved error messages <whatsnew315-improved-error-messages>` - +* :ref:`The official Windows 64-bit binaries now use the tail-calling interpreter + <whatsnew315-windows-tail-calling-interpreter>` New features ============ @@ -1294,18 +1295,6 @@ zlib Optimizations ============= -* Builds using Visual Studio 2026 (MSVC 18) may now use the new - :ref:`tail-calling interpreter <whatsnew314-tail-call-interpreter>`. - 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.) - * ``mimalloc`` is now used as the default allocator for for raw memory allocations such as via :c:func:`PyMem_RawMalloc` for better performance on :term:`free-threaded builds <free-threaded build>`. @@ -1962,6 +1951,23 @@ Build changes and :option:`-X dev <-X>` is passed to the Python or Python is built in :ref:`debug mode <debug-build>`. (Contributed by Donghee Na in :gh:`141770`.) +.. _whatsnew315-windows-tail-calling-interpreter: + +* 64-bit builds using Visual Studio 2026 (MSVC 18) may now use the new + :ref:`tail-calling interpreter <whatsnew314-tail-call-interpreter>`. + 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, + which the official Windows 64-bit binaries on python.org__ now use. + (Contributed by Chris Eibl, Ken Jin, and Brandt Bucher in :gh:`143068`. + Special thanks to Steve Dower, and the MSVC team including Hulon Jenkins.) + + __ https://www.python.org/downloads/windows/ + Porting to Python 3.15 ====================== _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
