What Changed When REX Was Re-Evaluated Against LLVM 22

Fri, 01 May 2026 00:00:00 +0000

The previous post closed the LLVM 21 performance story. That mattered, but it was not the end of the engineering question.

The next question was more uncomfortable:

1
2


If the OpenMP offloading runtime changes under us,
do the REX fixes still hold?

That is the question this post answers.

This is not another optimization post. No new benchmark-specific rewrite was added for LLVM 22. The point was to test whether the current REX design remained valid when the underlying OpenMP offloading stack moved from LLVM 21 to a source-built LLVM 22 toolchain.

Llvm22 on ./Code

What Changed When REX Was Re-Evaluated Against LLVM 22