some more safety tests

lib/risc/instructions/function_return.rb

@@ -7,6 +7,7 @@ module Risc
     def initialize( source , register )
       super(source)
       @register = register
+      raise "Not register #{register}" unless RiscValue.look_like_reg(register)
     end
     attr_reader :register
 

lib/risc/instructions/load_constant.rb

@@ -10,6 +10,7 @@ module Risc
       @register = register
       @constant = constant
       raise "Not Constant #{constant}" if constant.is_a?(Mom::SlotDefinition)
+      raise "Not register #{register}" unless RiscValue.look_like_reg(register)
     end
     attr_accessor :register , :constant
 

lib/risc/instructions/load_data.rb

@@ -13,6 +13,7 @@ module Risc
       @register = register
       @constant = constant
       raise "Not Integer #{constant}" unless constant.is_a?(Integer)
+      raise "Not register #{register}" unless RiscValue.look_like_reg(register)
     end
     attr_accessor :register , :constant
 

lib/risc/instructions/operator_instruction.rb

@@ -14,6 +14,8 @@ module Risc
       raise "unsuported operator :#{operator}:" unless [:+, :-, :>>, :<<, :*, :&, :|, :==].include?(operator)
       @left = left
       @right = right
+      raise "Not register #{left}" unless RiscValue.look_like_reg(left)
+      raise "Not register #{right}" unless RiscValue.look_like_reg(right)
     end
     attr_reader :operator, :left , :right