[clang] [Clang][Sema] Promote pointers to common address space in pointer subtraction (PR #217341)

[via cfe-commits]

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@@ -11902,6 +11902,37 @@ QualType Sema::CheckSubtractionOperands(ExprResult &LHS, ExprResult &RHS,
                                                LHS.get(), RHS.get()))
         return QualType();
 
+      // For pointer subtraction, if the address spaces differ but overlap,
+      // convert both pointers to the composite (superset) address space.
+      // This is needed because pointer subtraction compares addresses, and
+      // addresses in different spaces may have different sizes.
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addmisol wrote:

Updated.

https://github.com/llvm/llvm-project/pull/217341