diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
@@ -385,6 +385,8 @@
   case WebAssembly::ARGUMENT_v4f32_S:
   case WebAssembly::ARGUMENT_v2f64:
   case WebAssembly::ARGUMENT_v2f64_S:
+  case WebAssembly::ARGUMENT_exnref:
+  case WebAssembly::ARGUMENT_exnref_S:
     return true;
   default:
     return false;
@@ -423,6 +425,8 @@
   case WebAssembly::TEE_F64_S:
   case WebAssembly::TEE_V128:
   case WebAssembly::TEE_V128_S:
+  case WebAssembly::TEE_EXNREF:
+  case WebAssembly::TEE_EXNREF_S:
     return true;
   default:
     return false;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
@@ -75,6 +75,8 @@
     CopyOpcode = WebAssembly::COPY_F64;
   else if (RC == &WebAssembly::V128RegClass)
     CopyOpcode = WebAssembly::COPY_V128;
+  else if (RC == &WebAssembly::EXNREFRegClass)
+    CopyOpcode = WebAssembly::COPY_EXNREF;
   else
     llvm_unreachable("Unexpected register class");
 
diff --git a/llvm/test/CodeGen/WebAssembly/reg-argument.mir b/llvm/test/CodeGen/WebAssembly/reg-argument.mir
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/WebAssembly/reg-argument.mir
@@ -0,0 +1,59 @@
+# RUN: llc -mtriple=wasm32-unknown-unknown %s -o - -run-pass wasm-argument-move  | FileCheck %s
+
+# wasm-argument-move pass moves all ARGUMENT instructions to the top of the
+# entry BB.
+---
+name: argument_i32
+# CHECK-LABEL: argument_i32
+body: |
+  ; CHECK-LABEL: bb.0:
+  ; CHECK-NEXT: %1:i32 = ARGUMENT_i32 0
+  bb.0:
+    %0:i32 = CONST_I32 0, implicit-def $arguments
+    %1:i32 = ARGUMENT_i32 0, implicit $arguments
+    RETURN_VOID implicit-def $arguments
+...
+---
+name: argument_i64
+# CHECK-LABEL: argument_i64
+body: |
+  ; CHECK-LABEL: bb.0:
+  ; CHECK-NEXT: %1:i64 = ARGUMENT_i64 0
+  bb.0:
+    %0:i32 = CONST_I32 0, implicit-def $arguments
+    %1:i64 = ARGUMENT_i64 0, implicit $arguments
+    RETURN_VOID implicit-def $arguments
+...
+---
+name: argument_f32
+# CHECK-LABEL: argument_f32
+body: |
+  ; CHECK-LABEL: bb.0:
+  ; CHECK-NEXT: %1:f32 = ARGUMENT_f32 0
+  bb.0:
+    %0:i32 = CONST_I32 0, implicit-def $arguments
+    %1:f32 = ARGUMENT_f32 0, implicit $arguments
+    RETURN_VOID implicit-def $arguments
+...
+---
+name: argument_f64
+# CHECK-LABEL: argument_f64
+body: |
+  ; CHECK-LABEL: bb.0:
+  ; CHECK-NEXT: %1:f64 = ARGUMENT_f64 0
+  bb.0:
+    %0:i32 = CONST_I32 0, implicit-def $arguments
+    %1:f64 = ARGUMENT_f64 0, implicit $arguments
+    RETURN_VOID implicit-def $arguments
+...
+---
+name: argument_exnref
+# CHECK-LABEL: argument_exnref
+body: |
+  ; CHECK-LABEL: bb.0:
+  ; CHECK-NEXT: %1:exnref = ARGUMENT_exnref 0
+  bb.0:
+    %0:i32 = CONST_I32 0, implicit-def $arguments
+    %1:exnref = ARGUMENT_exnref 0, implicit $arguments
+    RETURN_VOID implicit-def $arguments
+...
diff --git a/llvm/test/CodeGen/WebAssembly/reg-copy.mir b/llvm/test/CodeGen/WebAssembly/reg-copy.mir
--- a/llvm/test/CodeGen/WebAssembly/reg-copy.mir
+++ b/llvm/test/CodeGen/WebAssembly/reg-copy.mir
@@ -55,3 +55,14 @@
     %0:v128 = COPY %1:v128
     RETURN_VOID implicit-def $arguments
 ...
+---
+name: copy_exnref
+# CHECK-LABEL: copy_exnref
+body: |
+  ; CHECK-LABEL: bb.0:
+  ; CHECK-NEXT: %0:exnref = COPY_EXNREF %1:exnref
+  ; CHECK-NEXT: RETURN_VOID
+  bb.0:
+    %0:exnref = COPY %1:exnref
+    RETURN_VOID implicit-def $arguments
+...