[llvm] [Attributor] Change allocation size and load/store offsets using AAPointerInfo for Alloca instructions (PR #72029)

[Vidush Singhal via llvm-commits]

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@@ -6181,11 +6278,53 @@ struct AAPointerInfo : public AbstractAttribute {
       }
     }
 
+    // Merge two access paths into one.
+    void mergeAccessPaths(const AccessPathSetTy *AccessPathsNew) const {
+      for (auto *Path : *AccessPathsNew)
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vidsinghal wrote:

yes it can be an empty set but not a nullptr, since i ensure to make memory for it.
https://github.com/llvm/llvm-project/blob/f1992d7fffbcc6b1bc64e97b5a885f4c9974e517/llvm/lib/Transforms/IPO/AttributorAttributes.cpp#L945
I will make the change you suggested. 

https://github.com/llvm/llvm-project/pull/72029