adding register_names to instruction protocol

lib/risc/instructions/branch.rb

@@ -11,6 +11,11 @@ module Risc
     end
     attr_reader :label
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      []
+    end
+
     def to_s
       case label
       when Label

lib/risc/instructions/dynamic_jump.rb

@@ -12,6 +12,11 @@ module Risc
     end
     attr_reader :register
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      [register.symbol ]
+    end
+
     def to_s
       class_source( register.to_s)
     end

lib/risc/instructions/function_call.rb

@@ -10,6 +10,11 @@ module Risc
     end
     attr_reader :method
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      []
+    end
+
     def to_s
       class_source method.name
     end

lib/risc/instructions/function_return.rb

@@ -11,6 +11,11 @@ module Risc
     end
     attr_reader :register
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      [register.symbol]
+    end
+
     def to_s
       class_source "#{register} "
     end

lib/risc/instructions/getter.rb

@@ -29,6 +29,13 @@ module Risc
     end
     attr_accessor :array , :index , :register
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      names = [array.symbol , register.symbol]
+      names << index.symbol if index.is_a?(RegisterValue)
+      names
+    end
+
     def to_s
       class_source "#{array}[#{index}] -> #{register}"
     end

lib/risc/instructions/instruction.rb

@@ -41,6 +41,11 @@ module Risc
     def precheck
     end
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      raise "Not implemented in #{self.class}"
+    end
+
     def to_cpu( translator )
       translator.translate( self )
     end

lib/risc/instructions/label.rb

@@ -23,6 +23,11 @@ module Risc
     end
     attr_reader :name , :address
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      []
+    end
+
     def to_cpu(translator)
       @cpu_label ||= super
     end

lib/risc/instructions/load_constant.rb

@@ -14,6 +14,11 @@ module Risc
     end
     attr_accessor :register , :constant
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      [register.symbol]
+    end
+
     def to_s
       class_source "#{register} <- #{constant_str}"
     end

lib/risc/instructions/load_data.rb

@@ -17,6 +17,11 @@ module Risc
     end
     attr_accessor :register , :constant
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      [register.symbol]
+    end
+
     def to_s
       class_source "#{register} <- #{constant}"
     end

lib/risc/instructions/operator_instruction.rb

@@ -32,6 +32,11 @@ module Risc
     end
     attr_reader :operator, :left , :right , :result
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      [left.symbol , right.symbol, result.symbol]
+    end
+
     def to_s
       class_source "#{left} #{operator} #{right}"
     end

lib/risc/instructions/setter.rb

@@ -27,6 +27,13 @@ module Risc
     end
     attr_accessor :register , :array , :index
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      names = [array.symbol , register.symbol]
+      names << index.symbol if index.is_a?(RegisterValue)
+      names
+    end
+
     def to_s
       class_source "#{register} -> #{array}[#{index}]"
     end

lib/risc/instructions/syscall.rb

@@ -16,6 +16,11 @@ module Risc
     end
     attr_reader :name
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      []
+    end
+
     def to_s
       class_source name
     end

lib/risc/instructions/transfer.rb

@@ -25,6 +25,11 @@ module Risc
     end
     attr_reader :from, :to
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      [from.symbol , to.symbol]
+    end
+
     def to_s
       class_source "#{from} -> #{to}"
     end