[llvm] [LV]Initial support for safe distance in predicated DataWithEVL vectorization mode. (PR #102897)

[via llvm-commits]

================
@@ -1490,13 +1486,29 @@ class LoopVectorizationCostModel {
     }
   }
 
+  /// Disables previously chosen tail folding policy, sets it to None. Expects,
+  /// that the tail policy was selected.
+  void disableTailFolding() {
+    assert(ChosenTailFoldingStyle && "Tail folding must be selected.");
+    ChosenTailFoldingStyle =
+        std::make_pair(TailFoldingStyle::None, TailFoldingStyle::None);
+  }
+
   /// Returns true if all loop blocks should be masked to fold tail loop.
   bool foldTailByMasking() const {
     // TODO: check if it is possible to check for None style independent of
     // IVUpdateMayOverflow flag in getTailFoldingStyle.
     return getTailFoldingStyle() != TailFoldingStyle::None;
   }
 
+  /// Return maximum safe number of elements to be processed, which do not
+  /// prevent store-load forwarding.
----------------
ayalz wrote:

This explains what max dependence distance is, which is indeed target independent. Why/does EVL need another value? Tried to answer below.

https://github.com/llvm/llvm-project/pull/102897