diff --git a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
--- a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
+++ b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
@@ -835,6 +835,9 @@
     MemRefType memRefType = xferOp.getMemRefType();
 
     // 1. Get the source/dst address as an LLVM vector pointer.
+    //    The vector pointer would always be on address space 0, therefore
+    //    addrspacecast shall be used when source/dst memrefs are not on
+    //    address space 0.
     // TODO: support alignment when possible.
     Value dataPtr = getDataPtr(loc, memRefType, adaptor.memref(),
                                adaptor.indices(), rewriter, getModule());