[llvm-branch-commits] [llvm] release/22.x: [Hexagon] Fix 64-bit funnel shift miscompilation with register shift amounts (#183669) (PR #185781)

[Brian Cain via llvm-branch-commits]

androm3da wrote:

> Was this a regression from a previous release? If so, which release?

It's an oldie for sure.

LLVM 7 introduced the funnel shift patterns, they were implemented for Hexagon in LLVM 8 (30c42e2ab6), and it was incorrect when introduced.  The generic DAG expansion could have handled it correctly for 7, so it was a regression from 7 to 8.

https://github.com/llvm/llvm-project/pull/185781