working on registers, awip (a work in progress)

lib/arm/move_instruction.rb

@@ -12,6 +12,10 @@ module Arm
 
       @immediate = 0      
       @rn = :r0 # register zero = zero bit pattern
+      raise inspect if  to.is_a?(Vm::Value) and 
+                        from.is_a?(Vm::Value) and 
+                        !@attributes[:shift_lsr] and
+                        to.register == from.register
     end
     
     # arm intrucions are pretty sensible, and always 4 bytes (thumb not supported)