[llvm] LoopVectorize ptr init (PR #139807)

[David Sherwood via llvm-commits]

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@@ -603,13 +603,13 @@ class InnerLoopVectorizer {
   // --- Vectorization state ---
 
   /// The vector-loop preheader.
-  BasicBlock *LoopVectorPreHeader;
+  BasicBlock *LoopVectorPreHeader = nullptr;
 
   /// The scalar-loop preheader.
-  BasicBlock *LoopScalarPreHeader;
+  BasicBlock *LoopScalarPreHeader = nullptr;
 
   /// Middle Block between the vector and the scalar.
-  BasicBlock *LoopMiddleBlock;
+  BasicBlock *LoopMiddleBlock = nullptr;
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david-arm wrote:

This looks like a nice fix! An alternative might be to disable the default constructor by adding

```
  InnerLoopVectorizer() = delete;
```

and then forcing the existing InnerLoopVectorizer constructor to explicitly set `LoopVectorPreHeader`, etc. to nullptr, as well as others such as `AddedSafetyChecks`? That way all the sensible defaults are being set in the same place. Any thoughts @fhahn?

https://github.com/llvm/llvm-project/pull/139807