Index: lib/Target/WebAssembly/WebAssemblyInstrControl.td
===================================================================
--- lib/Target/WebAssembly/WebAssemblyInstrControl.td
+++ lib/Target/WebAssembly/WebAssemblyInstrControl.td
@@ -125,8 +125,9 @@
 def THROW_I64 : I<(outs), (ins i32imm:$tag, I64:$val),
                   [(int_wasm_throw imm:$tag, I64:$val)], "throw   \t$tag, $val",
                   0x08>;
-def RETHROW : I<(outs), (ins i32imm:$rel_depth), [], "rethrow \t$rel_depth",
-                0x09>;
+// rethrow instruction takes an except_ref type argument, but it is omitted here
+// because it will be added after instruction selection.
+def RETHROW : I<(outs), (ins), [(int_wasm_rethrow)], "rethrow", 0x09>;
 } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1
 
 // Region within which an exception is caught: try / end_try
@@ -136,8 +137,3 @@
 } // Uses = [VALUE_STACK], Defs = [VALUE_STACK]
 
 } // Defs = [ARGUMENTS]
-
-// rethrow takes a relative depth as an argument, for which currently only 0 is
-// possible for C++. Once other languages need depths other than 0, depths will
-// be computed in CFGStackify.
-def : Pat<(int_wasm_rethrow), (RETHROW 0)>;
Index: test/CodeGen/WebAssembly/exception.ll
===================================================================
--- test/CodeGen/WebAssembly/exception.ll
+++ test/CodeGen/WebAssembly/exception.ll
@@ -15,7 +15,7 @@
 }
 
 ; CHECK-LABEL: rethrow:
-; CHECK-NEXT: rethrow 0
+; CHECK-NEXT: rethrow
 define void @rethrow() {
   call void @llvm.wasm.rethrow()
   ret void