[llvm] [LoopInterchange] Constrain LI within supported loop nest depth (PR #118656)

[via llvm-commits]

CongzheUalberta wrote:

> This patch is an extension to #115128.
> 
> After profiling LLVM test-suite, I see a lot of loop nest of depth more than `MaxLoopNestDepth` which is 10. Early exit for them would save compile-time as it would avoid computing DependenceInfo and CacheCost.

Do you have experimental results that supports the claim that 

> This patch is an extension to #115128.
> 
> After profiling LLVM test-suite, I see a lot of loop nest of depth more than `MaxLoopNestDepth` which is 10. Early exit for them would save compile-time as it would avoid computing DependenceInfo and CacheCost.

Would be good to know how much compile time reduction for LLVM test-suite you could achieve with this patch? 

https://github.com/llvm/llvm-project/pull/118656