From cc908bd3c4c6b991defaabe85e1acbf6529d8f4a Mon Sep 17 00:00:00 2001 From: "H. Vetinari" Date: Wed, 9 Apr 2025 12:20:12 +1100 Subject: [PATCH] update comment about LLVM bug relevant for --with-tail-call-interp performance --- Doc/whatsnew/3.14.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst index 5f84d8ba8b02c2..0f15a2a8a8f6af 100644 --- a/Doc/whatsnew/3.14.rst +++ b/Doc/whatsnew/3.14.rst @@ -390,8 +390,9 @@ For further information on how to build Python, see `compiler bug `_ found in Clang/LLVM 19, which causes the normal interpreter to be slower. We were unaware of this bug, resulting in inaccurate results. We sincerely apologize for - communicating results that were only accurate for certain versions of LLVM 19 - and 20. At the time of writing, this bug has not yet been fixed in LLVM 19-21. Thus + communicating results that were only accurate for LLVM v19.1.x and v20.1.0. In the meantime, + the bug has been fixed in LLVM v20.1.1 and for the upcoming v21.1, but it will remain + unfixed for LLVM v19.1.x and v20.1.0. Thus any benchmarks with those versions of LLVM may produce inaccurate numbers. (Thanks to Nelson Elhage for bringing this to light.)