-/// SSAUpdater - This class updates SSA form for a set of values defined in
-/// multiple blocks. This is used when code duplication or another unstructured
-/// transformation wants to rewrite a set of uses of one value with uses of a
-/// set of values.
+/// MachineSSAUpdater - This class updates SSA form for a set of virtual
+/// registers defined in multiple blocks. This is used when code duplication
+/// or another unstructured transformation wants to rewrite a set of uses of one
+/// vreg with uses of a set of vregs.