diff --git a/gcc/rtl.def b/gcc/rtl.def
index c9d72517ef7..17b9715de43 100644
--- a/gcc/rtl.def
+++ b/gcc/rtl.def
@@ -153,6 +153,11 @@ DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", 'm')
    at the index specified by the argument.  For MATCH_OPERATOR.  */
 DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", 'm')
 
+/* Appears only in machine descriptions.
+   Means match only something equal to what is stored in the operand table
+   at the index specified by the argument.  For MATCH_PARALLEL.  */
+DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", 'm')
+
 /* Appears only in machine descriptions.
    Defines the pattern for one kind of instruction.
    Operand: