From c094cf86e9fac9707a479c35b63e95f96e120b7e Mon Sep 17 00:00:00 2001 From: Ken Jin Date: Mon, 22 Dec 2025 23:23:12 +0000 Subject: [PATCH 1/3] Add tail call for MSVC for whats new in 3.15 --- Doc/whatsnew/3.15.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst index 3c7e28a00c9c1a..9add50dc558699 100644 --- a/Doc/whatsnew/3.15.rst +++ b/Doc/whatsnew/3.15.rst @@ -849,6 +849,16 @@ zlib Optimizations ============= +* Builds using Visual Studio 2026 (MSVC 18) may now use the new + :ref:`tail-calling interpreter `. + Results on an early experimental MSVC compiler reported roughly 15% speedups + 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 + to 40% for long-running small pure-Python scripts on Windows. + (Contributed by Chris Eibl, Ken Jin, and Brandt Bucher in :gh:`143068`. + Special thanks to help received from the MSVC team including Hulon Jenkins.) + csv --- From c6cb242cb3b201c7c10afb8d80905f28f2b2dff8 Mon Sep 17 00:00:00 2001 From: Ken Jin Date: Mon, 22 Dec 2025 23:23:53 +0000 Subject: [PATCH 2/3] nit --- Doc/whatsnew/3.15.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst index 9add50dc558699..8577b8e6e7cda8 100644 --- a/Doc/whatsnew/3.15.rst +++ b/Doc/whatsnew/3.15.rst @@ -851,7 +851,7 @@ Optimizations * Builds using Visual Studio 2026 (MSVC 18) may now use the new :ref:`tail-calling interpreter `. - Results on an early experimental MSVC compiler reported roughly 15% speedups + 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 From b230c3657e451eda000bb462343f83b96e69f136 Mon Sep 17 00:00:00 2001 From: Ken Jin Date: Mon, 22 Dec 2025 23:24:53 +0000 Subject: [PATCH 3/3] nit --- Doc/whatsnew/3.15.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst index 8577b8e6e7cda8..aa138c9cacb021 100644 --- a/Doc/whatsnew/3.15.rst +++ b/Doc/whatsnew/3.15.rst @@ -857,7 +857,7 @@ Optimizations observed speedups ranging from 15% for large pure-Python libraries to 40% for long-running small pure-Python scripts on Windows. (Contributed by Chris Eibl, Ken Jin, and Brandt Bucher in :gh:`143068`. - Special thanks to help received from the MSVC team including Hulon Jenkins.) + Special thanks to the MSVC team including Hulon Jenkins.) csv ---