[llvm] [TailDuplicator] Add maximum predecessors and successors to consider tail duplicating blocks (PR #78582)

[Quentin Dian via llvm-commits]

DianQK wrote:

> > We started seeing a ~36% regression in the https://github.com/llvm/llvm-test-suite/blob/main/SingleSource/Benchmarks/Misc/evalloop.c benchmark on AArch64. Is this expected?
> 
> @DianQK ^^
> 
> It's not blocking us in any way, but it would be nice to ensure nothing wrong is happening here.

I apologize for my late reply. (*^^*)
I think we can adjust the values of `tail-dup-succ-size` and `tail-dup-pred-size`, and based on my experiments, this compilation time is acceptable up to 100.

https://github.com/llvm/llvm-project/pull/78582