[llvm] [LV] Transform to handle exits in the scalar loop (PR #148626)

[Sander de Smalen via llvm-commits]

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@@ -402,6 +402,10 @@ static cl::opt<bool> ConsiderRegPressure(
     "vectorizer-consider-reg-pressure", cl::init(false), cl::Hidden,
     cl::desc("Discard VFs if their register pressure is too high."));
 
+static cl::opt<bool> HandleEarlyExitsInScalarTail(
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sdesmalen-arm wrote:

How does this interact with `[Force]TailFoldingStyle`? Should this option override the tail folding style (because it requires a scalar tail loop), or should there be a check somewhere to ensure `TailFoldingStyle = none`?

Also, what do you think of creating an enum (e.g. `EarlyExitStyle`) so that we can describe the different styles of handling early exits?

https://github.com/llvm/llvm-project/pull/148626