[llvm] [DAG] Recognise AVGFLOOR (((A >> 1) + (B >> 1)) + (A & B & 1)) patterns (PR #169644)

[Nikita Popov via llvm-commits]

nikic wrote:

Surprisingly, this change seems to have measurable compile-time impact: https://llvm-compile-time-tracker.com/compare.php?from=a108881b24ecfea8d194b33dd9fb211943065bca&to=804e768bda1697ce0449eec844bd9ac4f29aed64&stat=instructions:u

I suspect that ReassociatableOpc_match is very expensive.

https://github.com/llvm/llvm-project/pull/169644