[llvm] [LoopVectorize] Perform loop versioning for some early exit loops (PR #120603)

[Paul Walker via llvm-commits]

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@@ -1585,6 +1591,22 @@ class LoopVectorizationCostModel {
                                        ElementCount MaxSafeVF,
                                        bool FoldTailByMasking);
 
+  bool isSafeForAnyVectorWidth() const {
+    return Legal->isSafeForAnyVectorWidth() &&
+           (!Legal->hasUncountableEarlyExit() ||
+            !Legal->getNumPotentiallyFaultingLoads());
+  }
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paulwalker-arm wrote:

Given all the questions are answered by `LoopVectorizationLegality` why not just extend its implementation instead of adding a cost model specific implementation? 

https://github.com/llvm/llvm-project/pull/120603