[llvm] [LV] Add initial legality checks for ee loops with stores (PR #145663)

[David Sherwood via llvm-commits]

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@@ -542,7 +550,13 @@ class LoopVectorizationLegality {
   /// The list above is not based on theoretical limitations of vectorization,
   /// but simply a statement that more work is needed to support these
   /// additional cases safely.
-  bool isVectorizableEarlyExitLoop();
+  bool isVectorizableEarlyExitLoop(std::optional<LoadInst *> &);
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david-arm wrote:

Is it guaranteed to always be a load instruction that's critical for the early exit? Could it not be any arbitrary instruction where SCEV was unable to come up with a counted exit count?

https://github.com/llvm/llvm-project/pull/145663