return single message for "message" ie r0

other names, like next_message allocate  a new register

test/mom/send/test_setup_simple.rb

@@ -8,14 +8,15 @@ module Risc
     def setup
       super
       @input = "5.mod4"
-      @expect = [LoadConstant, LoadConstant, SlotToReg, SlotToReg, RegToSlot,
-                 RegToSlot, LoadConstant, SlotToReg, RegToSlot, LoadConstant,
-                 SlotToReg, RegToSlot, SlotToReg, LoadConstant, FunctionCall,
-                 Label]
+      @expect = [LoadConstant, LoadConstant, SlotToReg, RegToSlot, RegToSlot,
+                 SlotToReg, SlotToReg, RegToSlot, SlotToReg, SlotToReg,
+                 RegToSlot, SlotToReg, RegToSlot, SlotToReg, RegToSlot,
+                 LoadConstant, SlotToReg, RegToSlot, LoadConstant, SlotToReg,
+                 RegToSlot, SlotToReg, LoadConstant, FunctionCall, Label]
       @produced = produce_body
     end
 
-    def pest_send_instructions
+    def test_send_instructions
       assert_nil msg = check_nil , msg
     end
     def test_load_method
@@ -27,22 +28,28 @@ module Risc
       space = @produced.next(1)
       assert_load( space , Parfait::Space , :r2 )
     end
-    def test_load_message #from space (ie r2)
+    def test_load_first_message #from space (ie r2)
       sl = @produced.next( 2 )
       assert_slot_to_reg( sl , :r2 ,  4 ,  :r3 )
     end
-    def pest_load_next_message
+    def test_store_message_in_current
       sl = @produced.next( 3 )
-      assert_slot_to_reg( sl , :r2 ,  2 ,  :r4 )
+      assert_reg_to_slot( sl , :r3  ,  :r0 ,  2 )
     end
-    def pest_store_next_message
+    def pest_store_message_in_current
       sl = @produced.next( 4 )
-      assert_reg_to_slot( sl , :r4  ,  :r3 ,  4 )
+      assert_reg_to_slot( sl , :r4  ,  :r3 ,  7 )
     end
     def pest_store_current_message
       sl = @produced.next( 5 )
       assert_reg_to_slot( sl , :r2  ,  :r0 ,  2 )
     end
 
+
+    def pest_load_next_message
+      sl = @produced.next( 3 )
+      assert_slot_to_reg( sl , :r2 ,  2 ,  :r4 )
+    end
+
   end
 end

test/risc/test_builder.rb

@@ -9,16 +9,21 @@ module Risc
       compiler = Risc::MethodCompiler.new( init )
       @builder = Builder.new(compiler)
     end
-    def test_register_alloc_space
+    def test_alloc_space
       reg = @builder.space
       assert_equal RiscValue , reg.class
       assert_equal :Space , reg.type
     end
-    def test_register_alloc_message
-      reg = @builder.message
+    def test_next_message
+      reg = @builder.next_message
       assert_equal :r1 , reg.symbol
       assert_equal :Message , reg.type
     end
+    def test_message
+      reg = @builder.message
+      assert_equal :r0 , reg.symbol
+      assert_equal :Message , reg.type
+    end
     def test_returns_built
       r1 = RiscValue.new(:r1 , :Space)
       built = @builder.build{ space << r1 }
@@ -48,6 +53,12 @@ module Risc
       built = @builder.build{ space << r1 ; space << r1}
       assert_equal built.to.symbol , built.next.to.symbol
     end
+    def test_uses_message_as_message
+      r1 = RiscValue.new(:r1 , :Space)
+      built = @builder.build{ message[:receiver] << r1}
+      assert_equal RegToSlot , built.class
+      assert_equal :r0 , built.array.symbol
+    end
   end
 
   class TestBuilderNoBoot < MiniTest::Test