[llvm] [ARM] Speedups for CombineBaseUpdate. (PR #129725)

[Andrew Savonichev via llvm-commits]

asavonic wrote:

LGTM, thanks a lot David!

I can confirm that limiting `BaseUpdates.size()` is critical. Just setting MaxSteps was not enough to fix the issue.

https://github.com/llvm/llvm-project/pull/129725