diff --git a/include/opcode/ChangeLog b/include/opcode/ChangeLog
index cdf578add..19fd1b398 100644
--- a/include/opcode/ChangeLog
+++ b/include/opcode/ChangeLog
@@ -1,3 +1,8 @@
+2013-08-19  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	* mips.h (OP_OPTIONAL_REG): New mips_operand_type.
+	(mips_optional_operand_p): New function.
+
 2013-08-04  Jürgen Urban  <JuergenUrban@gmx.de>
 	    Richard Sandiford  <rdsandiford@googlemail.com>
 
diff --git a/include/opcode/mips.h b/include/opcode/mips.h
index ae6983b1d..6860fa794 100644
--- a/include/opcode/mips.h
+++ b/include/opcode/mips.h
@@ -346,6 +346,10 @@ enum mips_operand_type {
   /* Described by mips_reg_operand.  */
   OP_REG,
 
+  /* Like OP_REG, but can be omitted if the register is the same as the
+     previous operand.  */
+  OP_OPTIONAL_REG,
+
   /* Described by mips_reg_pair_operand.  */
   OP_REG_PAIR,
 
@@ -574,6 +578,15 @@ struct mips_pcrel_operand
   unsigned int flip_isa_bit : 1;
 };
 
+/* Return true if the assembly syntax allows OPERAND to be omitted.  */
+
+static inline bfd_boolean
+mips_optional_operand_p (const struct mips_operand *operand)
+{
+  return (operand->type == OP_OPTIONAL_REG
+	  || operand->type == OP_REPEAT_PREV_REG);
+}
+
 /* Return a version of INSN in which the field specified by OPERAND
    has value UVAL.  */