+ /// getMatchingSuperRegClass - Return a subclass of the specified register
+ /// class A so that each register in it has a sub-register of the
+ /// specified sub-register index which is in the specified register class B.
+ virtual const TargetRegisterClass *
+ getMatchingSuperRegClass(const TargetRegisterClass *A,
+ const TargetRegisterClass *B, unsigned Idx) const;
+