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

[David Sherwood via llvm-commits]

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@@ -407,6 +407,14 @@ class LoopVectorizationLegality {
     return hasUncountableEarlyExit() ? getUncountableEdge()->second : nullptr;
   }
 
+  /// Returns true if this is an early exit loop containing a store.
+  bool isConditionCopyRequired() const { return EarlyExitLoad.has_value(); }
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david-arm wrote:

I think this looks odd, i.e. the comment says `Returns true if this is an early exit loop containing a store.` but the code says `return EarlyExitLoad.has_value()`. I expect others reading this code will be confused as well. Can you add more comments explaining why it's using an early exit load to decide if the loop contains a store? Or is just that the comment itself is misleading?

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