diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -672,6 +672,15 @@
     if (op.getSection().hasValue())
       var->setSection(*op.getSection());
 
+    auto TargetTriple = llvm::Triple(llvmModule->getTargetTriple());
+    if (var->isWeakForLinker() && !var->hasCommonLinkage() &&
+        TargetTriple.isOSBinFormatCOFF()) {
+      auto *C = llvmModule->getOrInsertComdat(var->getName());
+      if (!var->isInterposable())
+        C->setSelectionKind(llvm::Comdat::ExactMatch);
+      var->setComdat(C);
+    }
+
     addRuntimePreemptionSpecifier(op.getDsoLocal(), var);
 
     Optional<uint64_t> alignment = op.getAlignment();