bsnes/higan/processor/m68k/instructions.cpp

646 lines
18 KiB
C++

auto M68K::testCondition(uint4 condition) -> bool {
switch(condition) {
case 0: return true; //T
case 1: return false; //F
case 2: return !r.c && !r.z; //HI
case 3: return r.c || r.z; //LS
case 4: return !r.c; //CC,HS
case 5: return r.c; //CS,LO
case 6: return !r.z; //NE
case 7: return r.z; //EQ
case 8: return !r.v; //VC
case 9: return r.v; //VS
case 10: return !r.n; //PL
case 11: return r.n; //MI
case 12: return r.n == r.v; //GE
case 13: return r.n != r.v; //LT
case 14: return r.n == r.v && !r.z; //GT
case 15: return r.n != r.v || r.z; //LE
}
unreachable;
}
//
template<> auto M68K::bytes<Byte>() -> uint { return 1; }
template<> auto M68K::bytes<Word>() -> uint { return 2; }
template<> auto M68K::bytes<Long>() -> uint { return 4; }
template<> auto M68K::bits<Byte>() -> uint { return 8; }
template<> auto M68K::bits<Word>() -> uint { return 16; }
template<> auto M68K::bits<Long>() -> uint { return 32; }
template<uint Size> auto M68K::lsb() -> uint32 { return 1; }
template<> auto M68K::msb<Byte>() -> uint32 { return 0x80; }
template<> auto M68K::msb<Word>() -> uint32 { return 0x8000; }
template<> auto M68K::msb<Long>() -> uint32 { return 0x80000000; }
template<> auto M68K::mask<Byte>() -> uint32 { return 0xff; }
template<> auto M68K::mask<Word>() -> uint32 { return 0xffff; }
template<> auto M68K::mask<Long>() -> uint32 { return 0xffffffff; }
template<> auto M68K::clip<Byte>(uint32 data) -> uint32 { return data & 0xff; }
template<> auto M68K::clip<Word>(uint32 data) -> uint32 { return data & 0xffff; }
template<> auto M68K::clip<Long>(uint32 data) -> uint32 { return data & 0xffffffff; }
template<> auto M68K::sign<Byte>(uint32 data) -> int32 { return (int8)data; }
template<> auto M68K::sign<Word>(uint32 data) -> int32 { return (int16)data; }
template<> auto M68K::sign<Long>(uint32 data) -> int32 { return (int32)data; }
template<uint Size> auto M68K::zero(uint32 result) -> bool {
return clip<Size>(result) == 0;
}
template<uint Size> auto M68K::negative(uint32 result) -> bool {
return sign<Size>(result) < 0;
}
//
template<uint Size, bool Extend> auto M68K::ADD(uint32 source, uint32 target) -> uint32 {
uint64 result = (uint64)source + (uint64)target;
if(Extend) result += r.x;
r.c = sign<Size>(result >> 1) < 0;
r.v = sign<Size>(~(target ^ source) & (target ^ result)) < 0;
if(Extend == 0) r.z = clip<Size>(result) == 0;
if(Extend == 1) if(clip<Size>(result)) r.z = 0;
r.n = sign<Size>(result) < 0;
r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionADD(DataRegister dr, uint1 direction, EffectiveAddress ea) -> void {
if(direction == 0) {
auto source = read<Size>(ea);
auto target = read<Size>(dr);
auto result = ADD<Size>(source, target);
write<Size>(dr, result);
} else {
auto source = read<Size>(dr);
auto target = read<Size>(ea);
auto result = ADD<Size>(source, target);
write<Size>(ea, result);
}
}
template<uint Size> auto M68K::instructionADDI(EffectiveAddress modify) -> void {
auto source = readPC<Size>();
auto target = read<Size>(modify);
auto result = ADD<Size>(source, target);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionADDA(AddressRegister ar, EffectiveAddress ea) -> void {
auto source = read<Size>(ea);
auto target = read<Size>(ar);
write<Long>(ar, source + target);
}
template<uint Size> auto M68K::instructionADDQ(uint4 immediate, EffectiveAddress modify) -> void {
auto source = read<Size>(modify);
auto target = immediate;
auto result = ADD<Size>(source, target);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionADDX(EffectiveAddress target_, EffectiveAddress source_) -> void {
auto source = read<Size>(source_);
auto target = read<Size>(target_);
auto result = ADD<Size, Extend>(source, target);
write<Size>(target, result);
}
template<uint Size> auto M68K::instructionANDI(EffectiveAddress ea) -> void {
auto source = readPC<Size>();
auto target = read<Size, NoUpdate>(ea);
auto result = target & source;
write<Size>(ea, result);
r.c = 0;
r.v = 0;
r.z = zero<Size>(result);
r.n = negative<Size>(result);
}
auto M68K::instructionANDI_TO_CCR() -> void {
auto data = readPC<Word>();
writeCCR(readCCR() & data);
}
auto M68K::instructionANDI_TO_SR() -> void {
if(!supervisor()) return;
auto data = readPC<Word>();
writeSR(readSR() & data);
}
template<uint Size> auto M68K::ASL(uint32 result, uint shift) -> uint32 {
bool carry = false;
uint32 overflow = 0;
for(auto _ : range(shift)) {
carry = result & msb<Size>();
uint32 before = result;
result <<= 1;
overflow |= before ^ result;
}
r.c = carry;
r.v = sign<Size>(overflow) < 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
if(shift) r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionASL(uint4 shift, DataRegister modify) -> void {
auto result = ASL<Size>(read<Size>(modify), shift);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionASL(DataRegister shift, DataRegister modify) -> void {
auto count = read<Long>(shift) & 63;
auto result = ASL<Size>(read<Size>(modify), count);
write<Size>(modify, result);
}
auto M68K::instructionASL(EffectiveAddress modify) -> void {
auto result = ASL<Word>(read<Word, NoUpdate>(modify), 1);
write<Word>(modify, result);
}
template<uint Size> auto M68K::ASR(uint32 result, uint shift) -> uint32 {
bool carry = false;
uint32 overflow = 0;
for(auto _ : range(shift)) {
carry = result & lsb<Size>();
uint32 before = result;
result = sign<Size>(result) >> 1;
overflow |= before ^ result;
}
r.c = carry;
r.v = sign<Size>(overflow) < 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
if(shift) r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionASR(uint4 shift, DataRegister modify) -> void {
auto result = ASR<Size>(read<Size>(modify), shift);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionASR(DataRegister shift, DataRegister modify) -> void {
auto count = read<Long>(shift) & 63;
auto result = ASR<Size>(read<Size>(modify), count);
write<Size>(modify, result);
}
auto M68K::instructionASR(EffectiveAddress modify) -> void {
auto result = ASR<Word>(read<Word, NoUpdate>(modify), 1);
write<Word>(modify, result);
}
auto M68K::instructionBCC(uint4 condition, uint8 displacement) -> void {
auto extension = readPC<Word>();
if(condition == 1) push<Long>(r.pc);
if(condition >= 2 && !testCondition(condition)) { //0 = BRA; 1 = BSR
if(displacement) r.pc -= 2;
} else {
r.pc -= 2;
r.pc += displacement ? sign<Byte>(displacement) : sign<Word>(extension);
}
}
template<uint Size> auto M68K::instructionBTST(DataRegister dr, EffectiveAddress ea) -> void {
auto bit = read<Size>(dr);
auto test = read<Size>(ea);
bit &= bits<Size>() - 1;
r.z = test.bit(bit) == 0;
}
template<uint Size> auto M68K::instructionBTST(EffectiveAddress ea) -> void {
auto bit = (uint8)readPC<Word>();
auto test = read<Size>(ea);
bit &= bits<Size>() - 1;
r.z = test.bit(bit) == 0;
}
template<uint Size> auto M68K::instructionCLR(EffectiveAddress ea) -> void {
read<Size>(ea);
write<Size>(ea, 0);
r.c = 0;
r.v = 0;
r.z = 1;
r.n = 0;
}
template<uint Size> auto M68K::CMP(uint32 source, uint32 target) -> uint32 {
uint64 result = (uint64)target - (uint64)source;
r.c = sign<Size>(result >> 1) < 0;
r.v = sign<Size>((target ^ source) & (target ^ result)) < 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionCMP(DataRegister dr, EffectiveAddress ea) -> void {
auto source = read<Size>(ea);
auto target = read<Size>(dr);
CMP<Size>(source, target);
}
template<uint Size> auto M68K::instructionCMPA(AddressRegister ar, EffectiveAddress ea) -> void {
auto source = read<Size>(ea);
auto target = read<Size>(ar);
CMP<Size>(source, target);
}
template<uint Size> auto M68K::instructionCMPI(EffectiveAddress ea) -> void {
auto source = readPC<Size>();
auto target = read<Size>(ea);
CMP<Size>(source, target);
}
template<uint Size> auto M68K::instructionCMPM(EffectiveAddress ax, EffectiveAddress ay) -> void {
auto source = read<Size>(ay);
auto target = read<Size>(ax);
CMP<Size>(source, target);
}
auto M68K::instructionDBCC(uint4 condition, DataRegister dr) -> void {
auto displacement = readPC<Word>();
if(!testCondition(condition)) {
uint16 result = read<Word>(dr);
write<Word>(dr, result - 1);
if(result) r.pc -= 2, r.pc += sign<Word>(displacement);
}
}
auto M68K::instructionEORI_TO_CCR() -> void {
auto data = readPC<Word>();
writeCCR(readCCR() ^ data);
}
auto M68K::instructionEORI_TO_SR() -> void {
if(!supervisor()) return;
auto data = readPC<Word>();
writeSR(readSR() ^ data);
}
auto M68K::instructionJSR(EffectiveAddress target) -> void {
push<Long>(r.pc);
r.pc = fetch<Long>(target);
}
auto M68K::instructionLEA(AddressRegister ar, EffectiveAddress ea) -> void {
write<Long>(ar, fetch<Long>(ea));
}
template<uint Size> auto M68K::LSL(uint32 result, uint shift) -> uint32 {
bool carry = false;
for(auto _ : range(shift)) {
carry = result & msb<Size>();
result <<= 1;
}
r.c = carry;
r.v = 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
if(shift) r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionLSL(uint4 immediate, DataRegister dr) -> void {
auto result = LSL<Size>(read<Size>(dr), immediate);
write<Size>(dr, result);
}
template<uint Size> auto M68K::instructionLSL(DataRegister sr, DataRegister dr) -> void {
auto shift = read<Long>(sr) & 63;
auto result = LSL<Size>(read<Size>(dr), shift);
write<Size>(dr, result);
}
auto M68K::instructionLSL(EffectiveAddress ea) -> void {
auto result = LSL<Word>(read<Word, NoUpdate>(ea), 1);
write<Word>(ea, result);
}
template<uint Size> auto M68K::LSR(uint32 result, uint shift) -> uint32 {
bool carry = false;
for(auto _ : range(shift)) {
carry = result & lsb<Size>();
result >>= 1;
}
r.c = carry;
r.v = 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
if(shift) r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionLSR(uint4 immediate, DataRegister dr) -> void {
auto result = LSR<Size>(read<Size>(dr), immediate);
write<Size>(dr, result);
}
template<uint Size> auto M68K::instructionLSR(DataRegister shift, DataRegister dr) -> void {
auto count = read<Long>(shift) & 63;
auto result = LSR<Size>(read<Size>(dr), count);
write<Size>(dr, result);
}
auto M68K::instructionLSR(EffectiveAddress ea) -> void {
auto result = LSR<Word>(read<Word, NoUpdate>(ea), 1);
write<Word>(ea, result);
}
template<uint Size> auto M68K::instructionMOVE(EffectiveAddress to, EffectiveAddress from) -> void {
auto data = read<Size>(from);
write<Size>(to, data);
r.c = 0;
r.v = 0;
r.z = zero<Size>(data);
r.n = negative<Size>(data);
}
template<uint Size> auto M68K::instructionMOVEA(AddressRegister ar, EffectiveAddress ea) -> void {
auto data = read<Size>(ea);
write<Long>(ar, data);
}
template<uint Size> auto M68K::instructionMOVEM(uint1 direction, EffectiveAddress ea) -> void {
auto list = readPC();
auto addr = fetch<Long>(ea);
for(uint n : range(16)) {
if(!list.bit(n)) continue;
//pre-decrement mode traverses registers in reverse order {A7-A0, D7-D0}
uint index = ea.mode == AddressRegisterIndirectWithPreDecrement ? 15 - n : n;
if(ea.mode == AddressRegisterIndirectWithPreDecrement) addr -= bytes<Size>();
if(direction == 0) {
auto data = index < 8 ? read<Size>(DataRegister{index}) : read<Size>(AddressRegister{index});
write<Size>(addr, data);
} else {
auto data = read<Size>(addr);
data = sign<Size>(data);
index < 8 ? write<Long>(DataRegister{index}, data) : write<Long>(AddressRegister{index}, data);
}
if(ea.mode == AddressRegisterIndirectWithPostIncrement) addr += bytes<Size>();
}
flush<Long>(ea, addr);
}
auto M68K::instructionMOVEQ(DataRegister dr, uint8 immediate) -> void {
write<Long>(dr, immediate);
r.c = 0;
r.v = 0;
r.z = zero<Byte>(immediate);
r.n = negative<Byte>(immediate);
}
auto M68K::instructionMOVE_FROM_SR(EffectiveAddress ea) -> void {
auto data = readSR();
write<Word>(ea, data);
}
auto M68K::instructionMOVE_TO_CCR(EffectiveAddress ea) -> void {
auto data = read<Byte>(ea);
writeCCR(data);
}
auto M68K::instructionMOVE_TO_SR(EffectiveAddress ea) -> void {
if(!supervisor()) return;
auto data = read<Word>(ea);
writeSR(data);
}
auto M68K::instructionMOVE_USP(uint1 direction, AddressRegister ar) -> void {
if(!supervisor()) return;
if(direction == 0) {
r.sp = read<Long>(ar);
} else {
write<Long>(ar, r.sp);
}
}
auto M68K::instructionNOP() -> void {
}
auto M68K::instructionORI_TO_CCR() -> void {
auto data = readPC<Word>();
writeCCR(readCCR() | data);
}
auto M68K::instructionORI_TO_SR() -> void {
if(!supervisor()) return;
auto data = readPC<Word>();
writeSR(readSR() | data);
}
template<uint Size> auto M68K::ROL(uint32 result, uint shift) -> uint32 {
bool carry = false;
for(auto _ : range(shift)) {
carry = result & msb<Size>();
result = result << 1 | carry;
}
r.c = carry;
r.v = 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionROL(uint4 shift, DataRegister modify) -> void {
auto result = ROL<Size>(read<Size>(modify), shift);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionROL(DataRegister shift, DataRegister modify) -> void {
auto count = read<Long>(shift) & 63;
auto result = ROL<Size>(read<Size>(modify), count);
write<Size>(modify, result);
}
auto M68K::instructionROL(EffectiveAddress modify) -> void {
auto result = ROL<Word>(read<Word, NoUpdate>(modify), 1);
write<Word>(modify, result);
}
template<uint Size> auto M68K::ROR(uint32 result, uint shift) -> uint32 {
bool carry = false;
for(auto _ : range(shift)) {
carry = result & lsb<Size>();
result >>= 1;
if(carry) result |= msb<Size>();
}
r.c = carry;
r.v = 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionROR(uint4 shift, DataRegister modify) -> void {
auto result = ROR<Size>(read<Size>(modify), shift);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionROR(DataRegister shift, DataRegister modify) -> void {
auto count = read<Long>(shift) & 63;
auto result = ROR<Size>(read<Size>(modify), count);
write<Size>(modify, result);
}
auto M68K::instructionROR(EffectiveAddress modify) -> void {
auto result = ROR<Word>(read<Word, NoUpdate>(modify), 1);
write<Word>(modify, result);
}
template<uint Size> auto M68K::ROXL(uint32 result, uint shift) -> uint32 {
bool carry = r.x;
for(auto _ : range(shift)) {
bool extend = carry;
carry = result & msb<Size>();
result = result << 1 | extend;
}
r.c = carry;
r.v = 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionROXL(uint4 shift, DataRegister modify) -> void {
auto result = ROXL<Size>(read<Size>(modify), shift);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionROXL(DataRegister shift, DataRegister modify) -> void {
auto count = read<Long>(shift) & 63;
auto result = ROXL<Size>(read<Size>(modify), count);
write<Size>(modify, result);
}
auto M68K::instructionROXL(EffectiveAddress modify) -> void {
auto result = ROXL<Word>(read<Word, NoUpdate>(modify), 1);
write<Word>(modify, result);
}
template<uint Size> auto M68K::ROXR(uint32 result, uint shift) -> uint32 {
bool carry = r.x;
for(auto _ : range(shift)) {
bool extend = carry;
carry = result & lsb<Size>();
result >>= 1;
if(extend) result |= msb<Size>();
}
r.c = carry;
r.v = 0;
r.z = clip<Size>(result) == 0;
r.n = sign<Size>(result) < 0;
r.x = r.c;
return clip<Size>(result);
}
template<uint Size> auto M68K::instructionROXR(uint4 shift, DataRegister modify) -> void {
auto result = ROXR<Size>(read<Size>(modify), shift);
write<Size>(modify, result);
}
template<uint Size> auto M68K::instructionROXR(DataRegister shift, DataRegister modify) -> void {
auto count = read<Long>(shift) & 63;
auto result = ROXR<Size>(read<Size>(modify), count);
write<Size>(modify, result);
}
auto M68K::instructionROXR(EffectiveAddress modify) -> void {
auto result = ROXR<Word>(read<Word, NoUpdate>(modify), 1);
write<Word>(modify, result);
}
auto M68K::instructionRTS() -> void {
r.pc = pop<Long>();
}
template<uint Size, bool Extend> auto M68K::SUB(uint32 source, uint32 target) -> uint32 {
uint64 result = source - target;
if(Extend) result -= r.x;
r.c = sign<Size>(result >> 1) < 0;
r.v = sign<Size>((target ^ source) & (target ^ result)) < 0;
if(Extend == 0) r.z = clip<Size>(result == 0);
if(Extend == 1) if(clip<Size>(result)) r.z = 0;
r.n = sign<Size>(result) < 0;
r.x = r.c;
return result;
}
template<uint Size> auto M68K::instructionSUB(EffectiveAddress source_, DataRegister target_) -> void {
auto source = read<Size>(source_);
auto target = read<Size>(target_);
auto result = SUB<Size>(source, target);
write<Size>(target_, result);
}
template<uint Size> auto M68K::instructionSUB(DataRegister source_, EffectiveAddress target_) -> void {
auto source = read<Size>(source_);
auto target = read<Size>(target_);
auto result = SUB<Size>(source, target);
write<Size>(target_, result);
}
template<uint Size> auto M68K::instructionSUBQ(uint4 immediate, EffectiveAddress ea) -> void {
auto source = immediate;
auto target = read<Size, NoUpdate>(ea);
auto result = SUB<Size>(source, target);
write<Size>(ea, result);
}
template<uint Size> auto M68K::instructionTST(EffectiveAddress ea) -> void {
auto data = read<Size>(ea);
r.c = 0;
r.v = 0;
r.z = zero<Size>(data);
r.n = negative<Size>(data);
}