diff --git a/lib/risc/builder.rb b/lib/risc/builder.rb
index dd517e99..35c4e6d3 100644
--- a/lib/risc/builder.rb
+++ b/lib/risc/builder.rb
@@ -56,7 +56,7 @@ module Risc
     def infer_type( name )
       as_string = name.to_s
       parts = as_string.split("_")
-      if(parts.last == "reg"  or parts.last == "obj" or parts.last == "tmp")
+      if( ["reg" , "obj" , "tmp" , "self" , "const", "1" , "2"].include?( parts.last ) )
         parts.pop
         as_string = parts.join("_")
       end
diff --git a/lib/risc/builtin/integer.rb b/lib/risc/builtin/integer.rb
index cab77655..15e1f5ea 100644
--- a/lib/risc/builtin/integer.rb
+++ b/lib/risc/builtin/integer.rb
@@ -102,24 +102,27 @@ module Risc
           return compiler
         end
 
-        # old helper function for div10 (which doesn't use builder yet)
-        def add_receiver(builder)
-          message = Risc.message_reg
-          ret_type = builder.compiler.receiver_type
-          ret = builder.compiler.use_reg( ret_type ).set_builder(builder)
-          builder.add_slot_to_reg(" load self" , message , :receiver , ret )
-          builder.add_slot_to_reg(  "int -> fix" , ret , Parfait::Integer.integer_index , ret)
-          return ret
-        end
-
+        # as the name suggests, this devides the integer (self) by ten
+        #
+        # This version is lifted from some arm assembler tricks and is _much_
+        # faster than the general div versions. I think it was about three
+        # times less instructions. Useful for itos
+        #
+        # In fact it is possible to generate specific div function for any given
+        # integer and some are even more faster (as eg div4).
         def div10( context )
           s = "div_10 "
           compiler = compiler_for(:Integer,:div10 ,{})
           builder = compiler.compiler_builder(compiler.source)
-          #FIX: this could load receiver once, reduce and then transfer twice
-          me = add_receiver( builder )
-          tmp = add_receiver( builder )
-          q = add_receiver( builder )
+          builder.build do
+            integer_self! << message[:receiver]
+            integer_self.reduce_int
+            integer_tmp! << integer_self
+            integer_reg! << integer_self
+          end
+          me = builder.integer_self
+          tmp = builder.integer_tmp
+          q = builder.integer_reg
           const = compiler.use_reg :fixnum , value: 1
           builder.add_load_data( s , 1 , const )
           # int tmp = self >> 1
diff --git a/test/risc/interpreter/calling/test_div10.rb b/test/risc/interpreter/calling/test_div10.rb
index 07c84ff7..ee3bbe80 100644
--- a/test/risc/interpreter/calling/test_div10.rb
+++ b/test/risc/interpreter/calling/test_div10.rb
@@ -14,32 +14,31 @@ module Risc
       check_main_chain [LoadConstant, LoadConstant, SlotToReg, SlotToReg, RegToSlot,
             RegToSlot, RegToSlot, RegToSlot, LoadConstant, SlotToReg, # 10
             RegToSlot, LoadConstant, SlotToReg, Branch, RegToSlot,
-            SlotToReg, FunctionCall, SlotToReg, SlotToReg, SlotToReg, # 20
-            SlotToReg, SlotToReg, SlotToReg, LoadData, OperatorInstruction,
-            LoadData, OperatorInstruction, OperatorInstruction, LoadData, Transfer, # 30
-            Branch, OperatorInstruction, OperatorInstruction, LoadData, Transfer,
-            OperatorInstruction, OperatorInstruction, LoadData, Transfer, OperatorInstruction, # 40
-            OperatorInstruction, LoadData, OperatorInstruction, LoadData, Branch,
-            Transfer, OperatorInstruction, OperatorInstruction, Transfer, LoadData, # 50
-            OperatorInstruction, LoadData, OperatorInstruction, OperatorInstruction, LoadConstant,
-            SlotToReg, SlotToReg, RegToSlot, Branch, RegToSlot, # 60
-            RegToSlot, SlotToReg, SlotToReg, RegToSlot, LoadConstant,
-            SlotToReg, RegToSlot, RegToSlot, SlotToReg, SlotToReg, # 70
-            SlotToReg, FunctionReturn, SlotToReg, SlotToReg, RegToSlot,
-            SlotToReg, SlotToReg, RegToSlot, Branch, SlotToReg, # 80
-            SlotToReg, RegToSlot, Branch, LoadConstant, SlotToReg,
-            RegToSlot, RegToSlot, SlotToReg, SlotToReg, SlotToReg, # 90
-            FunctionReturn, Transfer, SlotToReg, SlotToReg, Syscall,
-            NilClass, ]
+            SlotToReg, FunctionCall, SlotToReg, SlotToReg, Transfer, # 20
+            Transfer, LoadData, OperatorInstruction, LoadData, OperatorInstruction,
+            OperatorInstruction, LoadData, Transfer, OperatorInstruction, OperatorInstruction, # 30
+            Branch, LoadData, Transfer, OperatorInstruction, OperatorInstruction,
+            LoadData, Transfer, OperatorInstruction, OperatorInstruction, LoadData, # 40
+            OperatorInstruction, LoadData, Transfer, OperatorInstruction, Branch,
+            OperatorInstruction, Transfer, LoadData, OperatorInstruction, LoadData, # 50
+            OperatorInstruction, OperatorInstruction, LoadConstant, SlotToReg, SlotToReg,
+            RegToSlot, RegToSlot, RegToSlot, Branch, SlotToReg, # 60
+            SlotToReg, RegToSlot, LoadConstant, SlotToReg, RegToSlot,
+            RegToSlot, SlotToReg, SlotToReg, SlotToReg, FunctionReturn, # 70
+            SlotToReg, SlotToReg, RegToSlot, SlotToReg, SlotToReg,
+            RegToSlot, Branch, SlotToReg, SlotToReg, RegToSlot, # 80
+            Branch, LoadConstant, SlotToReg, RegToSlot, RegToSlot,
+            SlotToReg, SlotToReg, SlotToReg, FunctionReturn, Transfer, # 90
+            SlotToReg, SlotToReg, Syscall, NilClass, ]
        assert_equal 2 , get_return
     end
 
     def test_load_space
-      load_ins = main_ticks 55
+      load_ins = main_ticks 53
       assert_load load_ins, Parfait::Space
     end
     def test_load_to
-      to = main_ticks 56
+      to = main_ticks 54
       assert_slot_to_reg to , :r5 , 5 ,:r2
     end
     def test_load_25
@@ -48,7 +47,7 @@ module Risc
       assert_equal 25 , @interpreter.get_register(load_ins.register).value
     end
     def test_return_class
-      ret = main_ticks(72)
+      ret = main_ticks(70)
       assert_equal FunctionReturn ,  ret.class
       link = @interpreter.get_register( ret.register )
       assert_equal Fixnum , link.class
diff --git a/test/risc/test_builder2.rb b/test/risc/test_builder2.rb
index 48326abe..6a919eeb 100644
--- a/test/risc/test_builder2.rb
+++ b/test/risc/test_builder2.rb
@@ -31,6 +31,15 @@ module Risc
     def test_caller_obj
       assert_equal :Message , @builder.infer_type(:caller_obj).class_name
     end
+    def test_caller_const
+      assert_equal :Message , @builder.infer_type(:caller_const).class_name
+    end
+    def test_caller_self
+      assert_equal :Message , @builder.infer_type(:caller_self).class_name
+    end
+    def test_caller_1
+      assert_equal :Message , @builder.infer_type(:caller_1).class_name
+    end
     def test_message
       assert_equal :Message , @builder.infer_type(:message).class_name
     end