diff --git a/lib/risc.rb b/lib/risc.rb
index 5fe2f6ed..1794d884 100644
--- a/lib/risc.rb
+++ b/lib/risc.rb
@@ -26,6 +26,7 @@ require "parfait"
 require_relative "risc/parfait_adapter"
 require_relative "risc/parfait_boot"
 require_relative "risc/linker"
+require_relative "risc/callable_compiler"
 require_relative "risc/method_compiler"
 require_relative "risc/block_compiler"
 require_relative "risc/assembler"
diff --git a/lib/risc/callable_compiler.rb b/lib/risc/callable_compiler.rb
new file mode 100644
index 00000000..fc85d92e
--- /dev/null
+++ b/lib/risc/callable_compiler.rb
@@ -0,0 +1,104 @@
+module Risc
+
+  # CallableCompiler is used to generate risc instructions. It is an abstact base
+  # class shared by BlockCompiler and MethodCompiler
+
+  # - risc_instructions: The sequence of risc level instructions that mom was compiled to
+  # - cpu_instructions: The sequence of cpu specific instructions that the
+  #                      risc_instructions was compiled to
+  #                 Instructions derive from class Instruction and form a linked list
+
+  class CallableCompiler
+
+    def initialize( )
+      @regs = []
+      @risc_instructions = Risc.label(source_name, source_name)
+      @risc_instructions << Risc.label( source_name, "unreachable")
+      @current = @risc_instructions
+      @constants = []
+      @block_compilers = []
+    end
+    attr_reader :risc_instructions , :constants , :block_compilers
+
+    # convert the given mom instruction to_risc and then add it (see add_code)
+    # continue down the instruction chain unti depleted
+    # (adding moves the insertion point so the whole mom chain is added as a risc chain)
+    def add_mom( instruction )
+      while( instruction )
+        raise "whats this a #{instruction}" unless instruction.is_a?(Mom::Instruction)
+        #puts "adding mom #{instruction.to_s}:#{instruction.next.to_s}"
+        risc = instruction.to_risc( self )
+        add_code(risc)
+        reset_regs
+        #puts "adding risc #{risc.to_s}:#{risc.next.to_s}"
+        instruction = instruction.next
+      end
+    end
+
+    # add a constant (which get created during compilation and need to be linked)
+    def add_constant(const)
+      raise "Must be Parfait #{const}" unless const.is_a?(Parfait::Object)
+      @constants << const
+    end
+
+    # add a risc instruction after the current (insertion point)
+    # the added instruction will become the new insertion point
+    def add_code( instruction )
+      raise "Not an instruction:#{instruction.to_s}" unless  instruction.is_a?(Risc::Instruction)
+      raise instruction.to_s if( instruction.class.name.split("::").first == "Arm")
+      new_current = instruction.last #after insertion this point is lost
+      @current.insert(instruction) #insert after current
+      @current = new_current
+      self
+    end
+
+    # require a (temporary) register. code must give this back with release_reg
+    def use_reg( type , value = nil )
+      raise "Not type #{type.inspect}" unless type.is_a?(Symbol) or type.is_a?(Parfait::Type)
+      if @regs.empty?
+        reg = Risc.tmp_reg(type , value)
+      else
+        reg = @regs.last.next_reg_use(type , value)
+      end
+      @regs << reg
+      return reg
+    end
+
+    def copy( reg , source )
+      copied = use_reg reg.type
+      add_code Register.transfer( source , reg , copied )
+      copied
+    end
+
+    # releasing a register (accuired by use_reg) makes it available for use again
+    # thus avoiding possibly using too many registers
+    def release_reg( reg )
+      last = @regs.pop
+      raise "released register in wrong order, expect #{last} but was #{reg}" if reg != last
+    end
+
+    # reset the registers to be used. Start at r4 for next usage.
+    # Every statement starts with this, meaning each statement may use all registers, but none
+    # get saved. Statements have affect on objects.
+    def reset_regs
+      @regs.clear
+    end
+
+    # Build with builder (see there), adding the created instructions
+    def build(&block)
+      builder.build(&block)
+    end
+
+    # return a new code builder that uses this compiler
+    # CodeBuilder returns code after building
+    def code_builder( source)
+      CodeBuilder.new(self , source)
+    end
+
+    # return a CompilerBuilder
+    # CompilerBuilder adds the generated code to the compiler
+    def compiler_builder( source)
+      CompilerBuilder.new(self , source)
+    end
+  end
+end
diff --git a/lib/risc/method_compiler.rb b/lib/risc/method_compiler.rb
index a9258395..ccd6d6ad 100644
--- a/lib/risc/method_compiler.rb
+++ b/lib/risc/method_compiler.rb
@@ -4,25 +4,16 @@ module Risc
   # and to instantiate the methods correctly. Most of the init is typed layer stuff,
   # but there is some logic too.
 
-  # - risc_instructions: The sequence of risc level instructions that mom was compiled to
-  # - cpu_instructions: The sequence of cpu specific instructions that the
-  #                      risc_instructions was compiled to
-  #                 Instructions derive from class Instruction and form a linked list
-
-  class MethodCompiler
+  class MethodCompiler < CallableCompiler
 
     def initialize( method )
-      @regs = []
       @method = method
-      name = "#{method.self_type.name}.#{method.name}"
-      @risc_instructions = Risc.label(name, name)
-      @risc_instructions << Risc.label( name, "unreachable")
-      @current = @risc_instructions
-      @constants = []
-      @block_compilers = []
+      super()
     end
-    attr_reader :risc_instructions , :constants
 
+    def source_name
+      "#{@method.self_type.name}.#{@method.name}"
+    end
     def get_method
       @method
     end