diff --git a/lib/risc/instructions/branch.rb b/lib/risc/instructions/branch.rb
index e3dd6aef..5a14e97f 100644
--- a/lib/risc/instructions/branch.rb
+++ b/lib/risc/instructions/branch.rb
@@ -12,7 +12,7 @@ module Risc
     attr_reader :label
 
     # return an array of names of registers that is used by the instruction
-    def register_names
+    def register_attributes
       []
     end
 
diff --git a/lib/risc/instructions/dynamic_jump.rb b/lib/risc/instructions/dynamic_jump.rb
index 4f7aac07..b07d53a9 100644
--- a/lib/risc/instructions/dynamic_jump.rb
+++ b/lib/risc/instructions/dynamic_jump.rb
@@ -13,8 +13,8 @@ module Risc
     attr_reader :register
 
     # return an array of names of registers that is used by the instruction
-    def register_names
-      [register.symbol ]
+    def register_attributes
+      [:register ]
     end
 
     def to_s
diff --git a/lib/risc/instructions/function_call.rb b/lib/risc/instructions/function_call.rb
index 3df7271e..84e9838e 100644
--- a/lib/risc/instructions/function_call.rb
+++ b/lib/risc/instructions/function_call.rb
@@ -11,7 +11,7 @@ module Risc
     attr_reader :method
 
     # return an array of names of registers that is used by the instruction
-    def register_names
+    def register_attributes
       []
     end
 
diff --git a/lib/risc/instructions/function_return.rb b/lib/risc/instructions/function_return.rb
index b90a8611..3e57c177 100644
--- a/lib/risc/instructions/function_return.rb
+++ b/lib/risc/instructions/function_return.rb
@@ -12,8 +12,8 @@ module Risc
     attr_reader :register
 
     # return an array of names of registers that is used by the instruction
-    def register_names
-      [register.symbol]
+    def register_attributes
+      [:register]
     end
 
     def to_s
diff --git a/lib/risc/instructions/getter.rb b/lib/risc/instructions/getter.rb
index 8cc22374..ead30890 100644
--- a/lib/risc/instructions/getter.rb
+++ b/lib/risc/instructions/getter.rb
@@ -30,9 +30,9 @@ module Risc
     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)
+    def register_attributes
+      names = [:array , :register]
+      names << :index if index.is_a?(RegisterValue)
       names
     end
 
diff --git a/lib/risc/instructions/instruction.rb b/lib/risc/instructions/instruction.rb
index dcecc6dc..f0986260 100644
--- a/lib/risc/instructions/instruction.rb
+++ b/lib/risc/instructions/instruction.rb
@@ -42,10 +42,33 @@ module Risc
     end
 
     # return an array of names of registers that is used by the instruction
-    def register_names
+    def register_attributes
       raise "Not implemented in #{self.class}"
     end
 
+    # return an array of names of registers that is used by the instruction
+    def register_names
+      register_attributes.collect {|attr| get_register(attr)}
+    end
+
+    # get the register value that has the name (ie attribute by that name)
+    # return the registers name ie RegisterValue's symbol
+    def get_register(name)
+      instance_variable_get("@#{name}".to_sym).symbol
+    end
+
+    # set all registers that has the name "name"
+    # going through the register_names and setting all where the
+    # get_register would return name
+    # Set to the value given as second arg.
+    def set_registers(name , value)
+      register_attributes.each do |attr|
+        reg = instance_variable_get("@#{attr}".to_sym)
+        next unless reg.symbol == name
+        reg.set_name(value)
+      end
+    end
+
     def to_cpu( translator )
       translator.translate( self )
     end
diff --git a/lib/risc/instructions/label.rb b/lib/risc/instructions/label.rb
index 8bfec0e8..8fd5170e 100644
--- a/lib/risc/instructions/label.rb
+++ b/lib/risc/instructions/label.rb
@@ -24,7 +24,7 @@ module Risc
     attr_reader :name , :address
 
     # return an array of names of registers that is used by the instruction
-    def register_names
+    def register_attributes
       []
     end
 
diff --git a/lib/risc/instructions/load_constant.rb b/lib/risc/instructions/load_constant.rb
index cf2a4c18..92dbea46 100644
--- a/lib/risc/instructions/load_constant.rb
+++ b/lib/risc/instructions/load_constant.rb
@@ -15,8 +15,8 @@ module Risc
     attr_accessor :register , :constant
 
     # return an array of names of registers that is used by the instruction
-    def register_names
-      [register.symbol]
+    def register_attributes
+      [:register]
     end
 
     def to_s
diff --git a/lib/risc/instructions/load_data.rb b/lib/risc/instructions/load_data.rb
index 57389df8..26d3498d 100644
--- a/lib/risc/instructions/load_data.rb
+++ b/lib/risc/instructions/load_data.rb
@@ -18,8 +18,8 @@ module Risc
     attr_accessor :register , :constant
 
     # return an array of names of registers that is used by the instruction
-    def register_names
-      [register.symbol]
+    def register_attributes
+      [:register]
     end
 
     def to_s
diff --git a/lib/risc/instructions/operator_instruction.rb b/lib/risc/instructions/operator_instruction.rb
index 3f61e421..2d94a511 100644
--- a/lib/risc/instructions/operator_instruction.rb
+++ b/lib/risc/instructions/operator_instruction.rb
@@ -33,8 +33,8 @@ module Risc
     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]
+    def register_attributes
+      [:left , :right, :result]
     end
 
     def to_s
diff --git a/lib/risc/instructions/setter.rb b/lib/risc/instructions/setter.rb
index 06c962fb..59f68b27 100644
--- a/lib/risc/instructions/setter.rb
+++ b/lib/risc/instructions/setter.rb
@@ -28,9 +28,9 @@ module Risc
     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)
+    def register_attributes
+      names = [:array , :register]
+      names << :index if index.is_a?(RegisterValue)
       names
     end
 
diff --git a/lib/risc/instructions/syscall.rb b/lib/risc/instructions/syscall.rb
index a5de82ca..01934097 100644
--- a/lib/risc/instructions/syscall.rb
+++ b/lib/risc/instructions/syscall.rb
@@ -17,7 +17,7 @@ module Risc
     attr_reader :name
 
     # return an array of names of registers that is used by the instruction
-    def register_names
+    def register_attributes
       []
     end
 
diff --git a/lib/risc/instructions/transfer.rb b/lib/risc/instructions/transfer.rb
index 46eb15fe..9eade0d4 100644
--- a/lib/risc/instructions/transfer.rb
+++ b/lib/risc/instructions/transfer.rb
@@ -26,8 +26,8 @@ module Risc
     attr_reader :from, :to
 
     # return an array of names of registers that is used by the instruction
-    def register_names
-      [from.symbol , to.symbol]
+    def register_attributes
+      [:from , :to]
     end
 
     def to_s
diff --git a/lib/risc/register_value.rb b/lib/risc/register_value.rb
index e51a4813..ea45dc43 100644
--- a/lib/risc/register_value.rb
+++ b/lib/risc/register_value.rb
@@ -5,11 +5,15 @@ module Risc
   # The type is always known, and sometimes the value too
   # Or something about the value, like some instances types
   #
+  # During initial creation ssa-like names are given to the registers.
+  # Later the name is changed, with set_name. When that happens
+  # the original is retained as ssa attttribute for debugging.
+  #
   # When participating in the compiler dsl, a compiler may be set to get the
   # results of dsl operations (like <<) back to the compiler
   class RegisterValue
 
-    attr_reader :symbol , :type , :extra
+    attr_reader :symbol , :type , :extra , :ssa
 
     attr_reader :compiler
 
@@ -33,6 +37,17 @@ module Risc
       @type.class_name
     end
 
+    # During initial creation ssa-like names are given to the registers.
+    # Later the name is changed, with set_name. When that happens
+    # the original is retained as ssa attttribute for debugging.
+    def set_name( symbol )
+      raise "not Symbol #{symbol}:#{symbol.class}" unless symbol.is_a?(Symbol)
+      old = @symbol
+      @ssa = @symbol
+      @symbol = symbol
+      old
+    end
+
     # allows to set the compiler, which is mainly done by the compiler
     # but sometimes, eg in exit, one nneds to create the reg by hand and set
     # return the RegisterValue for chaining in assignment
diff --git a/test/risc/test_register_value1.rb b/test/risc/test_register_value1.rb
index 5fd0e15d..b7282625 100644
--- a/test/risc/test_register_value1.rb
+++ b/test/risc/test_register_value1.rb
@@ -50,5 +50,15 @@ module Risc
       assert_equal Parfait::Type , reg.type.class
       assert_equal "Integer_Type" , reg.type.name
     end
+    def test_has_ssa
+      assert_nil @r0.ssa
+    end
+    def test_set_name
+      assert_equal :message , @r0.set_name(:r0)
+    end
+    def test_set_ssa
+      @r0.set_name(:r0)
+      assert_equal :message , @r0.ssa
+    end
   end
 end