diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -4594,8 +4594,17 @@
       return failedImport("Dst pattern child has multiple results");
 
     std::optional<LLTCodeGen> OpTyOrNone;
-    if (ChildTypes.front().isMachineValueType())
-      OpTyOrNone = MVTToLLT(ChildTypes.front().getMachineValueType().SimpleTy);
+    if (ChildTypes.front().isMachineValueType()) {
+      MVT VT = ChildTypes.front().getMachineValueType();
+      // Allow import more patterns like ComplexPattern<iPTR, ..>.
+      if (VT == MVT::iPTR)
+        // Since we don't know the exact pointer size for target supporting
+        // multiple address modes when tables are generated, no LLT is passed
+        // into LLTCodeGen.
+        OpTyOrNone = LLTCodeGen();
+      else
+        OpTyOrNone = MVTToLLT(VT.SimpleTy);
+    }
     if (!OpTyOrNone)
       return failedImport("Dst operand has an unsupported type");