[flang-commits] [flang] [flang] Create TBAA subtree for COMMON block variables. (PR #156558)

[Slava Zakharin via flang-commits]

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@@ -98,8 +223,65 @@ class PassState {
   // attachment.
   bool attachLocalAllocTag();
 
+  // Return fir.global for the given name.
+  fir::GlobalOp getGlobalDefiningOp(mlir::StringAttr name) const {
+    return symTab.lookup<fir::GlobalOp>(name);
+  }
+
+  // Process fir::FortranVariableStorageOpInterface operations within
+  // the given op, and fill in declToStorageMap with the information
+  // about their physical storages and layouts.
+  void collectPhysicalStorageAliasSets(mlir::Operation *op);
+
+  // Return the byte size of the given declaration.
+  std::size_t getDeclarationSize(fir::FortranVariableStorageOpInterface decl) {
+    mlir::Type memType = fir::unwrapRefType(decl.getBase().getType());
+    auto [size, alignment] =
+        getTypeSizeAndAlignment(memType, llvmTypeConverter);
+    return llvm::alignTo(size, alignment);
+  }
+
+  // A StorageDesc specifies an operation that defines a physical storage
+  // and the <offset, size> pair within that physical storage where
+  // a variable resides.
+  struct StorageDesc {
+    StorageDesc() = delete;
+    StorageDesc(mlir::Operation *storageDef, std::uint64_t start,
+                std::size_t size)
+        : storageDef(storageDef), interval(start, size) {}
+
+    // Return a string representing the byte range of the variable within
+    // its storage, e.g. bytes_0_to_0 for a 1-byte variable starting
+    // at offset 0.
+    std::string getByteRangeStr() const {
+      return ("bytes_" + llvm::Twine(interval.getStart()) + "_to_" +
+              llvm::Twine(interval.getEnd()))
+          .str();
+    }
+
+    mlir::Operation *storageDef;
+    IntervalTy interval;
+  };
+
+  const StorageDesc *getStorageDesc(mlir::Operation *op) {
+    auto it = declToStorageMap.find(op);
+    return it == declToStorageMap.end() ? nullptr : &it->second;
+  }
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vzakhari wrote:

Sounds reasonable - I will do it!

https://github.com/llvm/llvm-project/pull/156558