-- MIT License

-- Copyright (c) 2021 Stephen Merrony

-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:

-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.

-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.

with Ada.Text_IO; use Ada.Text_IO;

with Resolver; use Resolver;

package body Processor.Nova_PC_P is 
   procedure Do_Nova_PC (I : Decoded_Instr_T; CPU : CPU_T) is
      Ring_Mask : constant Phys_Addr_T := CPU.PC and 16#7000_0000#;
   begin
      case I.Instruction is
         when I_JMP =>
            CPU.PC := (Resolve_8bit_Disp (CPU, I.Ind, I.Mode, I.Disp_15) and 16#7fff#) or Ring_Mask;

         when I_JSR =>
            declare
               Tmp_PC : constant Dword_T := Dword_T(CPU.PC) + 1;
            begin
               CPU.PC := (Resolve_8bit_Disp (CPU, I.Ind, I.Mode, I.Disp_15) and 16#7fff#) or Ring_Mask;
               CPU.AC(3) := Tmp_PC;
            end;

         when others =>
            Put_Line ("ERROR: Nova_PC instruction " & To_String(I.Mnemonic) & 
                        " not yet implemented");
            raise Execution_Failure with "ERROR: Nova_PC instruction " & To_String(I.Mnemonic) & 
                        " not yet implemented";
      end case;
   end Do_Nova_PC;
end Processor.Nova_PC_P;