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

[Florian Hahn via llvm-commits]

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@@ -3874,12 +3874,17 @@ FixedScalableVFPair LoopVectorizationCostModel::computeFeasibleMaxVF(
   // the memory accesses that is most restrictive (involved in the smallest
   // dependence distance).
   unsigned MaxSafeElements =
-      llvm::bit_floor(Legal->getMaxSafeVectorWidthInBits() / WidestType);
+      bit_floor(Legal->getMaxSafeVectorWidthInBits() / WidestType);
+  unsigned MaxSafeElementsPowerOf2 = MaxSafeElements;
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fhahn wrote:

Do we need the extra `MaxSafeElementsPowerOf2` variable?
```suggestion
      unsigned MaxSafeElementsPowerOf2 =  bit_floor(Legal->getMaxSafeVectorWidthInBits() / WidestType);
```

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