--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/llvm/test/TableGen/defmclass.td	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,50 @@
+// RUN: llvm-tblgen %s | FileCheck %s
+// XFAIL: vg_leak
+
+class XD { bits<4> Prefix = 11; }
+// CHECK: Prefix = { 1, 1, 0, 0 };
+class XS { bits<4> Prefix = 12; }
+class VEX { bit hasVEX_4VPrefix = 1; }
+
+def xd : XD;
+
+class BaseI {
+  bits<4> Prefix = 0;
+  bit hasVEX_4VPrefix = 0;
+}
+
+class I<bits<4> op> : BaseI {
+  bits<4> opcode = op;
+  int val = !if(!eq(Prefix, xd.Prefix), 7, 21);
+  int check = !if(hasVEX_4VPrefix, 0, 10);
+}
+
+multiclass R {
+  def rr : I<4>;
+}
+
+multiclass M {
+  def rm : I<2>;
+}
+
+multiclass Y {
+  defm SS : R, M, XD;
+// CHECK: Prefix = { 1, 1, 0, 0 };
+// CHECK: Prefix = { 1, 1, 0, 0 };
+  defm SD : R, M, XS;
+}
+
+// CHECK: int check = 0;
+defm Instr : Y, VEX;
+
+
+// Anonymous defm.
+
+multiclass SomeAnonymous<int x> {
+  def rm;
+  def mr;
+}
+
+// These multiclasses shouldn't conflict.
+defm : SomeAnonymous<1>;
+defm : SomeAnonymous<2>;
\ No newline at end of file