source: branches/simple/Instructions.pas

unit Instructions;

interface

uses
  Classes, SysUtils, Generics.Collections, Cpu;

type
  TParamType = (ptNone, ptNumber, ptNumber8, ptNumber16, ptNumber32, ptNumber64,
    ptReg, ptRegIndirect, ptRegIndirectIndex, ptRegIndirectGroup);
  TParamTypeArray = array of TParamType;

  TInstructionInfo = class
    Instruction: TInstruction;
    Name: string;
    Params: TParamTypeArray;
    Description: string;
  end;

  { TInstructionSet }

  TInstructionSet = class
    Items: TObjectList<TInstructionInfo>;
    function SearchName(Name: string): TInstructionInfo;
    function SearchInstruction(Instruction: TInstruction): TInstructionInfo;
    function AddNew(Instruction: TInstruction; Name: string;
      Params: TParamTypeArray; Description: string): TInstructionInfo;
    constructor Create;
    destructor Destroy; override;
  end;


implementation


{ TInstructionSet }

function TInstructionSet.SearchName(Name: string): TInstructionInfo;
var
  I: Integer;
begin
  I := 0;
  while (I < Items.Count) and (Items[I].Name <> Name) do Inc(I);
  if I < Items.Count then Result := Items[I]
    else Result := nil;
end;

function TInstructionSet.SearchInstruction(Instruction: TInstruction
  ): TInstructionInfo;
var
  I: Integer;
begin
  I := 0;
  while (I < Items.Count) and (Items[I].Instruction <> Instruction) do Inc(I);
  if I < Items.Count then Result := Items[I]
    else Result := nil;
end;

function TInstructionSet.AddNew(Instruction: TInstruction; Name: string;
  Params: TParamTypeArray; Description: string): TInstructionInfo;
begin
  Result := TInstructionInfo.Create;
  Result.Instruction := Instruction;
  Result.Name := Name;
  Result.Params := Params;
  Result.Description := Description;
  Items.Add(Result);
end;

constructor TInstructionSet.Create;
begin
  Items := TObjectList<TInstructionInfo>.Create;
  AddNew(inNop, 'NOP', [], 'No operation - The instruction doesn''t do anything.');
  AddNew(inHalt, 'HALT', [], 'It terminates program execution and halts processor. Processor can be waked up by interrupt.');
  AddNew(inLoadImmediate, 'LDI', [ptReg, ptNumber], 'Sets register to immediate constant value.');
  AddNew(inLoadImmediate8, 'LDI8', [ptReg, ptNumber8], 'Sets register to immediate constant value.');
  AddNew(inLoadImmediate16, 'LDI16', [ptReg, ptNumber16], 'Sets register to immediate constant value.');
  AddNew(inLoad, 'LD', [ptReg, ptReg], 'Copies value from one register to another.');
  AddNew(inLoad8, 'LD8', [ptReg, ptReg], 'Copies value from one register to another.');
  AddNew(inLoad16, 'LD16', [ptReg, ptReg], 'Copies value from one register to another.');
  AddNew(inStore, 'ST', [ptRegIndirect, ptReg], 'Stores value from register to memory.');
  AddNew(inStore8, 'ST8', [ptRegIndirect, ptReg], 'Stores value from register to memory.');
  AddNew(inStore16, 'ST16', [ptRegIndirect, ptReg], 'Stores value from register to memory.');
  AddNew(inInput, 'IN', [ptReg, ptRegIndirectGroup], 'Reads value from input port to register.');
  AddNew(inInput8, 'IN', [ptReg, ptRegIndirectGroup], 'Reads value from input port to register.');
  AddNew(inInput16, 'IN', [ptReg, ptRegIndirectGroup], 'Reads value from input port to register.');
  AddNew(inOutput, 'OUT', [ptRegIndirectGroup, ptReg], 'Writes value from register to output port.');
  AddNew(inOutput8, 'OUT8', [ptRegIndirectGroup, ptReg], 'Writes value from register to output port.');
  AddNew(inOutput16, 'OUT16', [ptRegIndirectGroup, ptReg], 'Writes value from register to output port.');
  AddNew(inJump, 'JP', [ptNumber], 'Unconditional absolute jump to defined address.');
end;

destructor TInstructionSet.Destroy;
begin
  FreeAndNil(Items);
  inherited;
end;

end.