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

[Paul Walker via llvm-commits]

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@@ -2133,6 +2155,41 @@ class GeneratedRTChecks {
 };
 } // namespace
 
+std::optional<unsigned> getMaxVScale(const Function &F,
+                                     const TargetTransformInfo &TTI) {
+  if (std::optional<unsigned> MaxVScale = TTI.getMaxVScale())
+    return MaxVScale;
+
+  if (F.hasFnAttribute(Attribute::VScaleRange))
+    return F.getFnAttribute(Attribute::VScaleRange).getVScaleRangeMax();
+
+  return std::nullopt;
+}
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paulwalker-arm wrote:

Does `getMaxVScale` need to be moved? I could not spot any uses in `addPointerAlignmentChecks` but perhaps I've missed something?  

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