public static void ADDI(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
gen.EmitGetRegister(inst.Value.Reg0, ctx);
gen.Emit(OpCodes.Dup);
gen.Emit(OpCodes.Ldind_U1);
gen.EmitLoadImmediate(inst);
gen.Emit(OpCodes.Add);
gen.Emit(OpCodes.Conv_U1);
gen.Emit(OpCodes.Stind_I1);
}
public static void LDREG(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
var method = typeof(Interpreter.Implementation).GetMethod(nameof(Implementation.LDREG));
//Args are: Chip8State state, byte regx
gen.Emit(OpCodes.Ldarg_0);
gen.Emit(OpCodes.Ldc_I4_S, inst.Value.Reg0);
gen.Emit(OpCodes.Call, method);
}
public static void STBCD(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
var method = typeof(Interpreter.Implementation).GetMethod(nameof(Implementation.STBCD));
//Args are: Chip8State state, ref byte regx
gen.Emit(OpCodes.Ldarg_0);
gen.EmitGetRegister(inst.Value.Reg0, ctx);
gen.Emit(OpCodes.Call, method);
}
public static void SNER(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
gen.EmitGetRegister(inst.Value.Reg0, ctx);
gen.Emit(OpCodes.Ldind_I1);
gen.Emit(OpCodes.Conv_U1);
gen.EmitGetRegister(inst.Value.Reg1, ctx);
gen.Emit(OpCodes.Ldind_I1);
gen.Emit(OpCodes.Conv_U1);
gen.Emit(OpCodes.Bne_Un, ctx.Label(inst.Offset + 4));
}
public static void JMP(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
if (inst.Instr.Value.Immediate16 == inst.Offset)
{
gen.Emit(OpCodes.Ret);
}
else
{
gen.Emit(OpCodes.Br, ctx.Labels[inst.Value.Immediate16]);
}
}
public static void ADDRI(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
gen.Emit(OpCodes.Ldarg_0); //reference for the last store call
gen.EmitGetRegister(inst.Value.Reg0, ctx);
gen.Emit(OpCodes.Ldind_I1);
gen.Emit(OpCodes.Conv_U1);
gen.Emit(OpCodes.Ldarg_0);
gen.Emit(OpCodes.Call, ctx.RegisterI.GetMethod);
gen.Emit(OpCodes.Add);
gen.Emit(OpCodes.Call, ctx.RegisterI.SetMethod);
}
public static void DRW(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
var method = typeof(Interpreter.Implementation).GetMethod(nameof(Implementation.DRW));
//Args are: Chip8State state, ref byte regx, ref byte regy, byte imm4
gen.Emit(OpCodes.Ldarg_0);
gen.EmitGetRegister(inst.Value.Reg0, ctx);
gen.EmitGetRegister(inst.Value.Reg1, ctx);
gen.Emit(OpCodes.Ldc_I4_S, inst.Value.Immediate4);
gen.Emit(OpCodes.Call, method);
}
public static void JMP0(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
List <Label> JumpTable = new List <Label>();
for (int i = inst.Value.Immediate16; i < inst.Value.Immediate16 + 256; i++)
{
JumpTable.Add(ctx.Label(i));
}
gen.EmitGetRegister(0, ctx);
gen.Emit(OpCodes.Ldind_I1);
gen.Emit(OpCodes.Conv_U1);
gen.Emit(OpCodes.Switch, JumpTable.ToArray());
}
public static void SHR(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
gen.EmitGetRegister(inst.Value.Reg0, ctx);
gen.Emit(OpCodes.Dup); //Duplicate address for loading
gen.Emit(OpCodes.Ldind_U1); //Load value
gen.Emit(OpCodes.Dup); //duplicate value for VF comparison
gen.Emit(OpCodes.Stloc_0); //Store for VF comparison
gen.Emit(OpCodes.Ldc_I4_1);
gen.Emit(OpCodes.Shr_Un); //Shift and store
gen.Emit(OpCodes.Stind_I1);
gen.EmitGetRegister(0xF, ctx);
gen.Emit(OpCodes.Ldloc_0);
gen.Emit(OpCodes.Ldc_I4_1);
gen.Emit(OpCodes.And);
gen.Emit(OpCodes.Stind_I1);
}
public static void CALL(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
gen.Emit(OpCodes.Ldarg_0);
gen.Emit(OpCodes.Ldarg_1);
gen.Emit(OpCodes.Call, ctx.Functions[inst.Value.Immediate16].Method);
}
public static void RET(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
gen.Emit(OpCodes.Ret);
}
public static void SYS(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
Debug.WriteLine("WARN: Sys called");
}
public static void SKNP(JITContext ctx, Disassembler.DecompEntry inst, ILGenerator gen)
{
Debug.WriteLine("WARN: Unimplemented input instruction");
//Skip next instruction if key with the value of Vx is pressed.
}
internal static void EmitLoadImmediate(this ILGenerator gen, Disassembler.DecompEntry inst) => gen.Emit(OpCodes.Ldc_I4, (int)inst.Value.Immediate16);
