twoapple-reboot/src/cpu/ctfe_d6502.d

1310 lines
30 KiB
D

module cpu.ctfe_d6502;
import cpu.data_d6502;
// The following versions are mutually exclusive.
// OpDelegates: each opcode is a method of the Cpu class.
version(OpDelegates)
{
enum versionCheck = 1;
enum opArray = true;
}
// OpFunctions: each opcode is a free function with a Cpu argument.
version(OpFunctions)
{
enum versionCheck = 2;
enum opArray = true;
// With free functions, strict and cumulative need to be set by
// version.
version(Strict)
enum vStrict = true;
else
enum vStrict = false;
version(Cumulative)
enum vCumulative = true;
else
enum vCumulative = false;
}
// OpSwitch: each opcode is inlined in a 256-case switch.
version(OpSwitch)
{
enum versionCheck = 3;
enum opArray = false;
}
/*
* OpNestedSwitch: each opcode is inlined in a nested switch.
*
* (The outer one switches on the high byte, with each case switching
* on the low byte.)
*/
version(OpNestedSwitch)
{
enum versionCheck = 4;
enum opArray = false;
}
// At least one of the previous versions must be specified.
static if (!__traits(compiles, { bool b = opArray; })) enum opArray = 0;
static assert (versionCheck);
string OpArrayDef()
{
version(OpDelegates)
return q{void delegate()[256] opcodes;};
else version(OpFunctions)
return q{void function(typeof(this))[256] opcodes;};
else
return "";
}
string OpArrayInit()
{
static if (!opArray) return "";
else
{
string ret;
foreach (op; 0..256)
{
version(OpDelegates)
ret ~= Fmt("opcodes[0x#] = &opcode_#;\n",
Hex2(op), Hex2(op));
version(OpFunctions)
ret ~= Fmt("opcodes[0x#] = &opcode_#!(typeof(this));\n",
Hex2(op), Hex2(op));
}
return ret;
}
}
string OpBodies(string chip, bool strict, bool cumulative)
{
static if (!opArray) return "";
else
{
string ret;
foreach (op; 0..256)
{
version(OpDelegates)
ret ~= "final void opcode_" ~ Hex2(op) ~ "()\n{\n" ~
If!(cumulative)("int cycles = 1;\n") ~
OpBody(op, chip, strict, cumulative) ~ "}\n";
version(OpFunctions)
ret ~= "void opcode_" ~ Hex2(op) ~
"(T)(T cpu) if (is" ~ chip ~ "!T)\n{\n" ~
If!(cumulative)("int cycles = 1;\n") ~
OpBody(op, chip, strict, cumulative) ~ "}\n";
}
/+
foreach (op; 13..256)
version(OpDelegates)
ret ~= "final void opcode_" ~ Hex2(op) ~ "()\n{\n" ~
If!(cumulative)("int cycles = 1;\n") ~
"" ~ "}\n";
version(OpFunctions)
ret ~= "void opcode_" ~ Hex2(op) ~
"(T)(T cpu) if (is" ~ chip ~ "!T)\n{\n" ~
If!(cumulative)("int cycles = 1;\n") ~
"" ~ "}\n";
+/
return ret;
}
}
string OpExecute(string chip, bool strict, bool cumulative)
{
version(OpDelegates)
return q{opcodes[opcode]();};
version(OpFunctions)
return q{opcodes[opcode](this);};
version(OpSwitch)
return Switch256(chip, strict, cumulative);
version(OpNestedSwitch)
return Switch16x16(chip, strict, cumulative);
}
string Switch256(string chip, bool strict, bool cumulative)
{
string ret = "final switch (opcode)\n{\n";
foreach (op; 0..256)
ret ~= "case 0x" ~ Hex2(op) ~ ":\n" ~
OpBody(op, chip, strict, cumulative) ~ "break;\n";
return ret ~ "}\n";
}
string Switch16x16(string chip, bool strict, bool cumulative)
{
string ret = "final switch (opcode & 0xF0)\n{\n";
foreach (opHi; 0..16)
{
ret ~= "case 0x" ~ Hex1(opHi) ~ "0:\n" ~
"final switch(opcode & 0x0F)\n{\n";
foreach (opLo; 0..16)
{
int op = opLo | (opHi << 4);
ret ~= "case 0x0" ~ Hex1(opLo) ~ ":\n" ~
OpBody(op, chip, strict, cumulative) ~
"break;\n";
}
ret ~= "}\nbreak;\n";
}
return ret ~ "}\n";
}
enum _PC = Attr("PC");
enum _A = Attr("A");
enum _X = Attr("X");
enum _Y = Attr("Y");
enum _N = Attr("N");
enum _V = Attr("V");
enum _D = Attr("D");
enum _I = Attr("I");
enum _Z = Attr("Z");
enum _C = Attr("C");
enum _S = Attr("S");
enum STACK = "0x0100 + " ~ _S;
struct Env
{
int op;
string chip;
bool s, c;
bool nmos, cmos;
int mode;
int exCyc;
this(int op, string chip, bool s, bool c)
{
this.op = op;
this.chip = chip;
this.s = s;
this.c = c;
nmos = (chip == "6502");
cmos = !nmos;
mode = opMode(op, chip);
exCyc = opExCyc(op, chip);
}
}
string OpBody(int op, string chip, bool s, bool c)
{
auto env = Env(op, chip, s, c);
string ret = ((op == 0x20) ? "" : Address(env));
final switch (opName(op, chip))
{
case "BRK":
ret ~= Break(env);
break;
case "RTI":
ret ~= RetInt(env);
break;
case "JSR":
ret ~= JumpSub(env);
break;
case "RTS":
ret ~= RetSub(env);
break;
case "JMP":
ret ~= Jump(env);
break;
case "KIL":
ret ~= _PC ~ "--;\n";
break;
case "BPL":
ret ~= Branch("!(" ~ _N ~ " & 0x80)", env);
break;
case "BMI":
ret ~= Branch("(" ~ _N ~ " & 0x80)", env);
break;
case "BVC":
ret ~= Branch("!" ~ _V, env);
break;
case "BVS":
ret ~= Branch(_V, env);
break;
case "BRA":
ret ~= Branch("true", env);
break;
case "BCC":
ret ~= Branch("!" ~ _C, env);
break;
case "BCS":
ret ~= Branch(_C, env);
break;
case "BNE":
ret ~= Branch(_Z, env);
break;
case "BEQ":
ret ~= Branch("!" ~ _Z, env);
break;
case "CLC":
ret ~= ClearFlag(_C);
break;
case "SEC":
ret ~= SetFlag(_C);
break;
case "CLI":
ret ~= ClearFlag(_I);
break;
case "SEI":
ret ~= SetFlag(_I);
break;
case "CLV":
ret ~= ClearFlag(_V);
break;
case "CLD":
ret ~= ClearFlag(_D);
break;
case "SED":
ret ~= SetFlag(_D);
break;
case "NOP":
ret ~= Nop(env);
break;
case "TAX":
ret ~= Transfer(_A, _X, env);
break;
case "TXA":
ret ~= Transfer(_X, _A, env);
break;
case "TAY":
ret ~= Transfer(_A, _Y, env);
break;
case "TYA":
ret ~= Transfer(_Y, _A, env);
break;
case "TSX":
ret ~= Transfer(_S, _X, env);
break;
case "TXS":
ret ~= Transfer(_X, _S, env);
break;
case "DEX":
ret ~= Dec(_X);
break;
case "DEY":
ret ~= Dec(_Y);
break;
case "INX":
ret ~= Inc(_X);
break;
case "INY":
ret ~= Inc(_Y);
break;
case "PHP":
ret ~= Push(Attr("statusToByte()"), env);
break;
case "PLP":
ret ~= PullStatus(env);
break;
case "PLA":
ret ~= PullReg(_A, env);
break;
case "PLX":
ret ~= PullReg(_X, env);
break;
case "PLY":
ret ~= PullReg(_Y, env);
break;
case "PHA":
ret ~= PushReg(_A, env);
break;
case "PHX":
ret ~= PushReg(_X, env);
break;
case "PHY":
ret ~= PushReg(_Y, env);
break;
case "LDA":
ret ~= Load(_A, env);
break;
case "LDX":
ret ~= Load(_X, env);
break;
case "LDY":
ret ~= Load(_Y, env);
break;
case "STA":
ret ~= Store(_A, env);
break;
case "STX":
ret ~= Store(_X, env);
break;
case "STY":
ret ~= Store(_Y, env);
break;
case "STZ":
ret ~= Store("0", env);
break;
case "CMP":
ret ~= Compare(_A, env);
break;
case "CPX":
ret ~= Compare(_X, env);
break;
case "CPY":
ret ~= Compare(_Y, env);
break;
case "BIT":
ret ~= Bit(env);
break;
case "ORA":
ret ~= Logic("|=", env);
break;
case "AND":
ret ~= Logic("&=", env);
break;
case "EOR":
ret ~= Logic("^=", env);
break;
case "ADC":
ret ~= Add(env);
break;
case "SBC":
ret ~= Sub(env);
break;
case "INC":
if (op == 0x1a)
ret ~= Inc(_A);
else
ret ~= RMW(Inc("data"), env);
break;
case "DEC":
if (op == 0x3a)
ret ~= Dec(_A);
else
ret ~= RMW(Dec("data"), env);
break;
case "ASL":
if (op == 0x0a)
ret ~= ShiftLeft(_A);
else
ret ~= RMW(ShiftLeft("data"), env);
break;
case "ROL":
if (op == 0x2a)
ret ~= RotateLeft(_A);
else
ret ~= RMW(RotateLeft("data"), env);
break;
case "LSR":
if (op == 0x4a)
ret ~= ShiftRight(_A);
else
ret ~= RMW(ShiftRight("data"), env);
break;
case "ROR":
if (op == 0x6a)
ret ~= ShiftRight(_A);
else
ret ~= RMW(RotateRight("data"), env);
break;
case "TRB":
ret ~= RMW(TestReset(), env);
break;
case "TSB":
ret ~= RMW(TestSet(), env);
break;
case "LAS":
ret ~= LAS_Undoc(env);
break;
case "LAX":
if (op != 0xAB)
ret ~= Load(_A ~ " = " ~ _X, env);
else
return "";
break;
case "SAX":
ret ~= Store(_A ~ " & " ~ _X, env);
break;
case "ANC":
ret ~= ANC_Undoc(env);
break;
case "ALR":
ret ~= ALR_Undoc(env);
break;
case "ARR":
ret ~= ARR_Undoc(env);
break;
case "AXS":
ret ~= AXS_Undoc(env);
break;
case "AHX":
return "";
case "SHY":
return "";
case "SHX":
return "";
case "TAS":
return "";
case "XAA":
return "";
case "SLO":
ret ~= RMW_Undoc(ShiftLeft("data"),
SetNZ(_A ~ " |= data"), env);
break;
case "RLA":
ret ~= RMW_Undoc(RotateLeft("data"),
SetNZ(_A ~ " &= data"), env);
break;
case "SRE":
ret ~= RMW_Undoc(ShiftRight("data"),
SetNZ(_A ~ " ^= data"), env);
break;
case "RRA":
ret ~= RMW_Undoc(RotateRight("data"), AddBase(env), env);
break;
case "DCP":
ret ~= RMW_Undoc(Dec("data"), CompareBase(_A, env), env);
break;
case "ISC":
ret ~= RMW_Undoc(Inc("data"), SubBase(env), env);
break;
}
return ret ~ Done(env);
}
string Break(Env env)
{
return IncPC() ~
PushPC(env) ~
Push(Attr("statusToByte()"), env) ~
SetFlag(_I) ~
ReadWord(_PC, "IRQ_VECTOR", env);
}
string JumpSub(Env env)
{
return ReadOp(Local("ushort", "address"), env) ~
Peek(STACK, env) ~
PushPC(env) ~
LoadHiByte("address", _PC ~ "++", env) ~
_PC ~ " = address;\n";
}
string RetSub(Env env)
{
return Peek(STACK, env) ~
PullPC(env) ~
Peek(_PC, env) ~
IncPC();
}
string RetInt(Env env)
{
return PullStatus(env) ~
PullPC(env);
}
string Jump(Env env)
{
bool cmos = env.cmos;
bool nmos = env.nmos;
if (env.op == 0x4c)
return _PC ~ " = address;\n";
else if (env.op == 0x6c)
return ReadWordOp("ushort", "base", env) ~
If!(cmos)(
Peek(_PC, env)) ~
ReadWordBasic(_PC, "base",
If!(nmos)(
"(base & 0xFF00) | cast(ubyte)(base + 1)",
"cast(ushort)(base + 1)"), env);
else if (env.op == 0x7c)
return ReadWordOp("ushort", "base", env) ~
Peek(_PC, env) ~
ReadWord(_PC, "cast(ushort)(base + " ~ _X ~ ")", env);
return "";
}
string Branch(string check, Env env)
{
return ReadOp(Local("ushort", "base"), env) ~
"if (" ~ check ~ ")\n{\n" ~
Peek(_PC, env) ~
Local("ushort", "address") ~
" = cast(ushort)(" ~ _PC ~ " + cast(byte)base);\n" ~
CheckShortcut(_PC, "address", env) ~
_PC ~ " = address;\n" ~
"}\n";
}
string Nop(Env env)
{
if (env.mode == IMP || env.mode == NP1 || env.mode == NP8)
return ""; // XXX add np1/np8 stuff
else
return PreAccess(env) ~
ReadRaw("address") ~ ";\n";
}
string Transfer(string source, string dest, Env env)
{
return dest ~ " = " ~ source ~ ";\n" ~
((env.op != 0x9a) ? SetNZ(dest) : "");
}
string PullReg(string reg, Env env)
{
return Peek(STACK, env) ~
PullInto(reg, env) ~
SetNZ(reg);
}
string PushReg(string reg, Env env)
{
return Push(reg, env);
}
string Load(string reg, Env env)
{
return ReadInto(reg, "address", env) ~
SetNZ(reg);
}
string Store(string reg, Env env)
{
return Write("address", reg, env);
}
string Compare(string reg, Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
CompareBase(reg, env);
}
string CompareBase(string reg, Env env)
{
return UpdateFlag(_C, reg ~ " >= data") ~
SetNZ("cast(ubyte)(" ~ reg ~ " - data)");
}
string Bit(Env env)
{
bool notImm = (env.mode != IMM);
return ReadInto(Local("ubyte", "data"), "address", env) ~
If!(notImm)(
_N ~ " = data;\n" ~
_V ~ " = ((data & 0x40) != 0);\n") ~
_Z ~ " = (" ~ _A ~ " & data);\n";
}
string Logic(string action, Env env)
{
return ReadInto(_A, action, "address", env) ~
SetNZ(_A);
}
string Add(Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
AddBase(env);
}
string AddBase(Env env)
{
return "if (" ~ _D ~ ")\n{\n" ~
DecAdd(env) ~
"}\nelse\n{\n" ~
HexAdd(env) ~
"}\n";
}
string HexAdd(Env env)
{
return "uint sum = " ~ _A ~ " + data + " ~ _C ~ ";\n" ~
_V ~
" = (!((" ~ _A ~ " ^ data) & 0x80)) && ((data ^ sum) & 0x80);\n" ~
_C ~ " = (sum > 0xFF);\n" ~
SetNZ(_A ~ " = cast(ubyte)sum");
}
string DecAdd(Env env)
{
bool cmos = env.cmos;
return "int a = " ~ _A ~ ";\n" ~
"int al = (a & 0x0F) + (data & 0x0F) + " ~ _C ~ ";\n" ~
"if (al >= 0x0A)\n" ~
"al = ((al + 0x06) & 0x0F) + 0x10;\n" ~
"a = (a & 0xF0) + (data & 0xF0) + al;\n" ~
If!(cmos)("",
_N ~ " = cast(ubyte)a;\n" ~
_Z ~ " = cast(ubyte)(" ~ _A ~ " + data + " ~ _C ~ ");\n") ~
_V ~
" = (!((" ~ _A ~ " ^ data) & 0x80)) && ((data ^ a) & 0x80);\n" ~
"if (a >= 0xA0)\n" ~
"a = a + 0x60;\n" ~
_C ~ " = (a >= 0x100);\n" ~
If!(cmos)(
SetNZ(_A ~ " = cast(ubyte)a") ~ Peek(_PC, env),
_A ~ " = cast(ubyte)a;\n");
}
string Sub(Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
SubBase(env);
}
string SubBase(Env env)
{
bool nmos = env.nmos;
return "if (" ~ _D ~ ")\n{\n" ~
If!(nmos)(DecSubNMOS(), DecSubCMOS(env)) ~
"}\nelse\n{\n" ~
HexSub() ~
"}\n";
}
string HexSub()
{
return "uint diff = " ~ _A ~ " - data - !" ~ _C ~ ";\n" ~
_V ~
" = ((" ~ _A ~ " ^ diff) & 0x80) && ((" ~
_A ~ " ^ data) & 0x80);\n" ~
_C ~ " = (diff < 0x100);\n" ~
SetNZ(_A ~ " = cast(ubyte)diff");
}
string DecSubNMOS()
{
return "int a = " ~ _A ~ ";\n" ~
"int al = (a & 0x0F) - (data & 0x0F) - !" ~ _C ~ ";\n" ~
"if (al < 0)\n" ~
"al = ((al - 0x06) & 0x0F) - 0x10;\n" ~
"a = (a & 0xF0) - (data & 0xF0) + al;\n" ~
"if (a < 0)\n" ~
"a = a - 0x60;\n" ~
"uint diff = " ~ _A ~ " - data - !" ~ _C ~ ";\n" ~
_V ~
" = ((" ~ _A ~ " ^ diff) & 0x80) && ((" ~
_A ~ " ^ data) & 0x80);\n" ~
_C ~ " = (diff < 0x100);\n" ~
SetNZ("cast(ubyte)diff") ~
_A ~ " = cast(ubyte)a;\n";
}
string DecSubCMOS(Env env)
{
return "int a = " ~ _A ~ ";\n" ~
"int al = (a & 0x0F) - (data & 0x0F) - !" ~ _C ~ ";\n" ~
"a = a - data - !" ~ _C ~ ";\n" ~
"if (a < 0) a = a - 0x60;\n" ~
"if (al < 0) a = a - 0x06;\n" ~
"uint diff = " ~ _A ~ " - data - !" ~ _C ~ ";\n" ~
_V ~
" = ((" ~ _A ~ " ^ diff) & 0x80) && ((" ~
_A ~ " ^ data) & 0x80);\n" ~
_C ~ " = (diff < 0x100);\n" ~
Peek(_PC, env) ~
SetNZ(_A ~ " = cast(ubyte)a");
}
string Inc(string val)
{
return val ~ "++;\n" ~
SetNZ(val);
}
string Dec(string val)
{
return val ~ "--;\n" ~
SetNZ(val);
}
string ShiftLeft(string val)
{
return _C ~ " = (" ~ val ~ " > 0x7F);\n" ~
SetNZ(val ~ " = cast(ubyte)(" ~ val ~ " << 1)");
}
string RotateLeft(string val)
{
return "auto oldC = " ~ _C ~ ";\n" ~
_C ~ " = (" ~ val ~ " > 0x7f);\n" ~
SetNZ(val ~ " = cast(ubyte)(" ~ val ~ " << 1 | (oldC ? 1 : 0))");
}
string ShiftRight(string val)
{
return _C ~ " = ((" ~ val ~ " & 0x01) != 0);\n" ~
SetNZ(val ~ " = " ~ val ~ " >> 1");
}
string RotateRight(string val)
{
return "auto oldC = " ~ _C ~ ";\n" ~
_C ~ " = ((" ~ val ~ " & 0x01) != 0);\n" ~
SetNZ(val ~ " = (" ~ val ~ " >> 1 | (oldC ? 0x80 : 0))");
}
string TestReset()
{
return _Z ~ " = data & " ~ _A ~ ";\n" ~
"data &= (~" ~ _A ~ ");\n";
}
string TestSet()
{
return _Z ~ " = data & " ~ _A ~ ";\n" ~
"data |= " ~ _A ~ ";\n";
}
string RMW(string action, Env env)
{
bool nmos = env.nmos;
return ReadInto(Local("ubyte", "data"), "address", env) ~
If!(nmos)(Poke("address", "data", env),
Peek("address", env)) ~
action ~
Write("address", "data", env);
}
string RMW_Undoc(string action1, string action2, Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
Poke("address", "data", env) ~
action1 ~
Write("address", "data", env) ~
action2;
}
string LAS_Undoc(Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
SetNZ(_X ~ " = " ~ _A ~ " = (" ~ _S ~ " & data)");
}
string ARR_Undoc(Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
"ubyte tmp1 = data & " ~ _A ~ ";\n" ~
"if (" ~ _D ~ ")\n{\n" ~
"ubyte tmp2 = cast(ubyte)((tmp1 >> 1) + (" ~
_C ~ " ? 0x80 : 0));\n" ~
_N ~ " = " ~ _Z ~ " = tmp2;\n" ~
_V ~ " = (((tmp2 ^ tmp1) & 0x40) != 0);\n" ~
"if ((data & 0x0F) + (tmp1 & 0x01) > 5)\n" ~
"tmp2 = (tmp2 & 0xF0) + ((tmp2 + 0x6) & 0x0F);\n" ~
"if (tmp1 + (tmp1 & 0x10) >= 0x60)\n{\n" ~
"tmp2 += 0x60;\n" ~
SetFlag(_C) ~
"}\nelse\n" ~
ClearFlag(_C) ~
_A ~ " = tmp2;\n" ~
"}\nelse{\n" ~
_A ~ " = cast(ubyte)((tmp1 >> 1) + (" ~
_C ~ " ? 0x80 : 0));\n" ~
_N ~ " = " ~ _Z ~ " = " ~_A ~ ";\n" ~
"tmp1 >>= 7;\n" ~
_C ~ " = (tmp1 != 0);\n" ~
_V ~ " = ((tmp1 ^ ((" ~ _A ~ " >> 5) & 1)) != 0);\n}";
}
string ANC_Undoc(Env env)
{
return ReadInto(_A, "address", env) ~
SetNZ(_A) ~
_C ~ " = (" ~ _A ~ " > 0x7f);\n";
}
string ALR_Undoc(Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
_A ~ " &= data;\n" ~
ShiftRight(_A);
}
string AXS_Undoc(Env env)
{
return ReadInto(Local("ubyte", "data"), "address", env) ~
_X ~ " &= " ~ _A ~ ";\n" ~
CompareBase(_X, env);
}
string Local(string type)
{
version(OpFunctions)
return type ~ " ";
else
return "";
/+
version(OpSwitch)
return "";
else version(OpNestedSwitch)
return "";
else
return type ~ " ";
+/
}
string Local(string type, string var)
{
version(OpFunctions)
return type ~ " " ~ var;
else
return var;
/+
version(OpSwitch)
return var;
else version(OpNestedSwitch)
return var;
else
return type ~ " " ~ var;
+/
}
string Attr(string var)
{
version(OpFunctions)
return "cpu." ~ var;
else
return var;
}
string Address(Env env)
{
final switch (env.mode)
{
case IMP:
return AddrIMP(env);
case IMM:
return AddrIMM(env);
case ZP:
return AddrZP(env);
case ZPX:
return AddrZPXY(_X, env);
case ZPY:
return AddrZPXY(_Y, env);
case IZX:
return AddrIZX(env);
case IZY:
return AddrIZY(env);
case ABS:
return AddrABS(env);
case ABX:
return AddrABXY(_X, env);
case ABY:
return AddrABXY(_Y, env);
case IND:
return "";
case REL:
return "";
case ZPI:
return AddrZPI(env);
case ABI:
return "";
case NP1:
return "";
case NP8:
return AddrNP8(env);
case KIL:
return "";
}
return "";
}
string AddrIMM(Env env)
{
return Local("ushort") ~ "address = " ~ _PC ~ "++;\n";
}
string AddrIMP(Env env)
{
return Peek(_PC, env);
}
string AddrZP(Env env)
{
return ReadOp(Local("ushort", "address"), env);
}
string AddrZPXY(string reg, Env env)
{
bool nmos = env.nmos;
return ReadOp(Local("ushort", "base"), env) ~
If!(nmos)(
Peek("base", env),
Peek(_PC, env)) ~
Local("ushort") ~
"address = cast(ubyte)(base + " ~ reg ~ ");\n";
}
string AddrIZX(Env env)
{
bool nmos = env.nmos;
return ReadOp(Local("ushort", "base"), env) ~
If!(nmos)(
Peek("base", env),
Peek(_PC, env)) ~
ReadWordZP("ushort", "address", "base + " ~ _X, env);
}
string AddrIZY(Env env)
{
return ReadOp("ubyte vector", env) ~
ReadWordZP("ushort", "base", "vector", env) ~
Local("ushort") ~
"address = cast(ushort)(base + " ~ _Y ~ ");\n" ~
CheckShortcut("base", "address", env);
}
string AddrABS(Env env)
{
return ReadWordOp("ushort", "address", env);
}
string AddrABXY(string reg, Env env)
{
return ReadWordOp("ushort", "base", env) ~
Local("ushort") ~ "address = cast(ushort)(base + " ~ reg ~ ");\n" ~
CheckShortcut("base", "address", env);
}
string AddrZPI(Env env)
{
return ReadOp(Local("ushort", "base"), env) ~
ReadWordZP("ushort", "address", "base", env);
}
string AddrNP8(Env env)
{
return ReadOp(Local("ushort", "base"), env) ~
Peek(_PC, env) ~
IncPC() ~
Peek("0xff00 | base", env) ~
Peek("0xffff", env) ~
Peek("0xffff", env) ~
Peek("0xffff", env) ~
Peek("0xffff", env);
}
string CheckShortcut(string base, string addr, Env env)
{
bool nmos = env.nmos;
int exCyc = env.exCyc;
return "ushort guess = (" ~ base ~ " & 0xFF00) | cast(ubyte)" ~ addr ~ ";\n" ~
"if (guess != " ~ addr ~ ")\n{\n" ~
If!(nmos)(Peek("guess", env),
Peek(_PC, env)) ~
"}\n" ~
If!(exCyc)("else\n{\n" ~ Peek("address", env) ~ "}\n");
}
string ReadInto(string var, string action, string addr, Env env)
{
return PreAccess(env) ~
var ~ " " ~ action ~ " " ~ ReadRaw("(" ~ addr ~ ")") ~ ";\n";
}
string ReadInto(string var, string addr, Env env)
{
return ReadInto(var, "=", addr, env);
}
string ReadOp(string var, Env env)
{
return ReadInto(var, _PC ~ "++", env);
}
string ReadRaw(string addr)
{
return Attr("memory") ~ ".read(" ~ addr ~")";
}
string ReadWordBasic(string type, string var, string addr1, string addr2,
Env env)
{
return LoadLoByte(type, var, addr1, env) ~
LoadHiByte(var, addr2, env);
}
string ReadWordBasic(string var, string addr1, string addr2, Env env)
{
return ReadWordBasic("", var, addr1, addr2, env);
}
string ReadWord(string type, string var, string addr, Env env)
{
return ReadWordBasic(type, var, addr, "cast(ushort)(" ~ addr ~ " + 1)",
env);
}
string ReadWord(string var, string addr, Env env)
{
return ReadWord("", var, addr, env);
}
string ReadWordZP(string type, string var, string addr, Env env)
{
return ReadWordBasic(type, var, "cast(ubyte)( " ~ addr ~ ")",
"cast(ubyte)(" ~ addr ~ " + 1)", env);
}
string ReadWordZP(string var, string addr, Env env)
{
return ReadWordZP("", var, addr, env);
}
string ReadWordOp(string type, string var, Env env)
{
return ReadWordBasic(type, var, _PC ~ "++", _PC ~ "++", env);
}
string ReadWordOp(string var, Env env)
{
return ReadWordOp("", var, env);
}
string PreAccess(Env env)
{
bool c = env.c;
return If!(c)("++cycles;\n", Attr("clock") ~ ".tick();\n");
}
string Peek(string addr, Env env)
{
bool s = env.s;
return PreAccess(env) ~
If!(s)(Attr("memory") ~ ".read(" ~ addr ~");\n");
}
string Poke(string addr, string val, Env env)
{
bool s = env.s;
return PreAccess(env) ~
If!(s)(
Attr("memory") ~ ".write(" ~ addr ~ ", " ~ val ~ ");\n");
}
string Write(string addr, string val, Env env)
{
return PreAccess(env) ~
Attr("memory") ~ ".write(" ~ addr ~ ", " ~ val ~ ");\n";
}
string IncPC()
{
return "++" ~ _PC ~ ";\n";
}
string IncSP()
{
return "++" ~ _S ~ ";\n";
}
string DecSP()
{
return "--" ~ _S ~ ";\n";
}
string PullStatus(Env env)
{
return Peek(STACK, env) ~
IncSP() ~
PreAccess(env) ~
Attr("statusFromByte") ~ "(" ~
ReadRaw(STACK) ~ ");\n";
}
string PullInto(string var, Env env)
{
return IncSP() ~
ReadInto(var, STACK, env);
}
string Push(string val, Env env)
{
return Write(STACK, val, env) ~
DecSP();
}
string PushPC(Env env)
{
return Push(HiByte(_PC), env) ~
Push(LoByte(_PC), env);
}
string PullPC(Env env)
{
return PullInto(_PC, env) ~
IncSP() ~
LoadHiByte(_PC, STACK, env);
}
string LoadLoByte(string type, string var, string addr, Env env)
{
return PreAccess(env) ~
Local(type, var) ~ " = " ~ ReadRaw(addr) ~ ";\n";
}
string LoadHiByte(string var, string addr, Env env)
{
return PreAccess(env) ~
var ~ " |= (" ~ ReadRaw(addr) ~ " << 8);\n";
}
string SetFlag(string flag)
{
return flag ~ " = true;\n";
}
string ClearFlag(string flag)
{
return flag ~ " = false;\n";
}
string UpdateFlag(string flag, string val)
{
return flag ~ " = (" ~ val ~ ");\n";
}
string SetNZ(string var)
{
return _N ~ " = " ~ _Z ~ " = (" ~ var ~ ");\n";
}
string Done(Env env)
{
bool c = env.c;
return If!(c)(Attr("clock") ~ ".tick(cycles);\n");
}
string HiByte(string var)
{
return var ~ " >> 8";
}
string LoByte(string var)
{
return var ~ " & 0xff";
}
string If(alias cond)(string yes, string no = "")
{
if (cond)
return yes;
else
return no;
}
string opName(int op, string chip)
{
if (chip == "6502")
return OP_NAMES_6502[op];
else
return OP_NAMES_65C02[op];
}
int opMode(int op, string chip)
{
if (chip == "6502")
return ADDR_MODES_6502[op];
else
return ADDR_MODES_65C02[op];
}
int opExCyc(int op, string chip)
{
if (chip == "6502")
return EXTRA_CYCLES_6502[op];
else
return EXTRA_CYCLES_65C02[op];
}
// Custom string formatting.
enum HEX_DIGITS = "0123456789abcdef";
string Hex1(int dec)
{
return HEX_DIGITS[dec..dec+1];
}
string Hex2(int dec)
{
int highNybble = (dec & 0xF0) >> 4;
int lowNybble = dec & 0x0F;
return HEX_DIGITS[highNybble..highNybble+1] ~
HEX_DIGITS[lowNybble..lowNybble+1];
}
string Fmt(string f, string[] p ...)
{
if (!p.length) return "ERROR";
string ret;
size_t last;
size_t other;
for (size_t i = 0; i < f.length; i++)
{
if (f[i] == '#')
{
if (other == p.length) return "ERROR";
ret ~= f[last..i] ~ p[other++];
last = i + 1;
}
}
return ret ~ f[last..$];
}