[llvm] [LV]Split store-load forward distance analysis from other checks, NFC (PR #121156)

[Florian Hahn via llvm-commits]

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@@ -216,6 +216,12 @@ class MemoryDepChecker {
     return MaxSafeVectorWidthInBits;
   }
 
+  /// Return safe power-of-2 number of elements, which do not prevent store-load
+  /// forwarding and safe to operate simultaneously.
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fhahn wrote:

Also comment says this returns the number of elements, but it returns the number of bits size which does not prevent store-load forwarding?

https://github.com/llvm/llvm-project/pull/121156