more work on instrucitons, mov this time

lib/arm/move_instruction.rb

@@ -4,7 +4,6 @@ module Arm
 
   class MoveInstruction < Vm::MoveInstruction
     include Arm::Constants
-    include LogicHelper
 
     def initialize(first , attributes) 
       super(first , attributes)
@@ -13,13 +12,63 @@ module Arm
       @attributes[:opcode] = attributes[:opcode]
       @operand = 0
 
-      @i = 0      
-      @rd = @first
+      @immediate = 0      
       @rn = :r0 # register zero = zero bit pattern
     end
-  
+    
+    # arm intrucions are pretty sensible, and always 4 bytes (thumb not supported)
+    def length
+      4
+    end
+
     def build
-      do_build @attributes[:right]
+      right = @attributes[:right]
+      if right.is_a?(Vm::StringConstant)
+        # do pc relative addressing with the difference to the instuction
+        # 8 is for the funny pipeline adjustment (ie oc pointing to fetch and not execute)
+        right = Vm::IntegerConstant.new( right.position - self.position - 8 )
+        @rn = :pc
+      end
+      if( right.is_a? Fixnum ) #HACK to not have to change the code just now
+        right = Vm::IntegerConstant.new( right )
+      end
+      if (right.is_a?(Vm::IntegerConstant))
+        if (right.integer.fits_u8?)
+          # no shifting needed
+          @operand = right.integer
+          @immediate = 1
+        elsif (op_with_rot = calculate_u8_with_rr(right))
+          @operand = op_with_rot
+          @immediate = 1
+          raise "hmm"
+        else
+          raise "cannot fit numeric literal argument in operand #{right.inspect}"
+        end
+      elsif (right.is_a?(Symbol) or right.is_a?(Vm::Integer))
+        @operand = reg_code(right)    #integer means the register the integer is in (otherwise constant)
+        @immediate = 0                # ie not immediate is register
+      else
+        raise "invalid operand argument #{right.inspect} , #{inspect}"
+      end
+      shift_handling
+    end
+
+    def assemble(io)
+      build
+      instuction_class = 0b00 # OPC_DATA_PROCESSING
+      val = shift(@operand , 0)
+      val |= shift(reg_code(@first) ,            12)     
+      val |= shift(reg_code(@rn) ,            12+4)   
+      val |= shift(@attributes[:update_status_flag] , 12+4+4)#20 
+      val |= shift(op_bit_code ,        12+4+4  +1)
+      val |= shift(@immediate ,                  12+4+4  +1+4) 
+      val |= shift(instuction_class ,   12+4+4  +1+4+1) 
+      val |= shift(cond_bit_code ,      12+4+4  +1+4+1+2)
+      io.write_uint32 val
+    end
+    def shift val , by
+      raise "Not integer #{val}:#{val.class}" unless val.is_a? Fixnum
+      val << by
     end
   end
-end
+end