Implementing CPX and CPY

sources/CPU/CPU.cpp

@@ -351,6 +351,14 @@ namespace ComSquare::CPU
 		case Instructions::INX: 	this->INX();	return 2;
 		case Instructions::INY: 	this->INY();	return 2;
 
+		case Instructions::CPX_IM: 	this->CPX(this->_getImmediateAddrForX());	return 2 + !this->_registers.p.m;
+		case Instructions::CPX_ABS: this->CPX(this->_getAbsoluteAddr());		return 4 + !this->_registers.p.m;
+		case Instructions::CPX_DP: 	this->CPX(this->_getDirectAddr());		return 3 + !this->_registers.p.m + this->_registers.dl != 0;
+
+		case Instructions::CPY_IM: 	this->CPY(this->_getImmediateAddrForX());	return 2 + !this->_registers.p.m;
+		case Instructions::CPY_ABS: this->CPY(this->_getAbsoluteAddr());		return 4 + !this->_registers.p.m;
+		case Instructions::CPY_DP: 	this->CPY(this->_getDirectAddr());		return 3 + !this->_registers.p.m + this->_registers.dl != 0;
+
 		default:
 			throw InvalidOpcode("CPU", opcode);
 		}

sources/CPU/CPU.hpp

@@ -333,7 +333,15 @@ namespace ComSquare::CPU
 		TXS = 0x9A,
 
 		INX = 0xE8,
-		INY = 0xC8
+		INY = 0xC8,
+
+		CPX_IM = 0xE0,
+		CPX_ABS = 0xEC,
+		CPX_DP = 0xE4,
+
+		CPY_IM = 0xC0,
+		CPY_ABS = 0xCC,
+		CPY_DP = 0xC4
 	};
 
 	//! @brief The main CPU
@@ -497,6 +505,10 @@ namespace ComSquare::CPU
 		void INX();
 		//! @brief Increment the Y register
 		void INY();
+		//! @brief Compare the X register with the memory
+		void CPX(uint24_t valueAddr);
+		//! @brief Compare the Y register with the memory
+		void CPY(uint24_t valueAddr);
 	public:
 		explicit CPU(std::shared_ptr<Memory::MemoryBus> bus, Cartridge::Header &cartridgeHeader);
 		CPU(const CPU &) = default;

sources/CPU/Instructions/InternalInstruction.cpp

@@ -188,4 +188,42 @@ namespace ComSquare::CPU
 		this->_registers.p.z = this->_registers.y == 0;
 		this->_registers.p.n = this->_registers.y & negativeFlag;
 	}
+
+	void CPU::CPX(uint24_t valueAddr)
+	{
+		unsigned value = this->_bus->read(valueAddr++);
+
+		if (this->_registers.p.x_b) {
+			uint8_t x = this->_registers.x;
+			x -= value;
+			this->_registers.p.z = x == 0;
+			this->_registers.p.n = x & 0x80u;
+		} else {
+			value += this->_bus->read(valueAddr) << 8u;
+			uint16_t x = this->_registers.x;
+			x -= value;
+			this->_registers.p.z = x == 0;
+			this->_registers.p.n = x & 0x8000u;
+		}
+		this->_registers.p.c = this->_registers.x >= value;
+	}
+
+	void CPU::CPY(uint24_t valueAddr)
+	{
+		unsigned value = this->_bus->read(valueAddr++);
+
+		this->_registers.p.c = this->_registers.y >= value;
+		if (this->_registers.p.x_b) {
+			uint8_t y = this->_registers.y;
+			y -= value;
+			this->_registers.p.z = y == 0;
+			this->_registers.p.n = y & 0x80u;
+		} else {
+			value += this->_bus->read(valueAddr) << 8u;
+			uint16_t y = this->_registers.y;
+			y -= value;
+			this->_registers.p.z = y == 0;
+			this->_registers.p.n = y & 0x8000u;
+		}
+	}
 }

sources/Debugger/CPUDebug.cpp

@@ -337,6 +337,14 @@ namespace ComSquare::Debugger
 		case Instructions::INX: 	 return "INX";
 		case Instructions::INY: 	 return "INY";
 
+		case Instructions::CPX_IM:	 return "CPX " + this->_getImmediateValueForX(pc);
+		case Instructions::CPX_ABS:	 return "CPX " + this->_getAbsoluteValue(pc);
+		case Instructions::CPX_DP:	 return "CPX";
+
+		case Instructions::CPY_IM:	 return "CPY " + this->_getImmediateValueForX(pc);
+		case Instructions::CPY_ABS:	 return "CPY " + this->_getAbsoluteValue(pc);
+		case Instructions::CPY_DP:	 return "CPY";
+
 		default: return "Unknown";
 		}
 	}

tests/CPU/testInternal.cpp

@@ -539,3 +539,69 @@ Test(INY, 8bits)
 	cr_assert_eq(pair.second.cpu->_registers.p.z, true, "The zero flag should be set");
 	cr_assert_eq(pair.second.cpu->_registers.p.n, false, "The negative flag should not be set");
 }
+
+Test(CPX, basic)
+{
+	auto pair = Init();
+	pair.second.cpu->_registers.p.x_b = true;
+	pair.second.cpu->_registers.p.flags = 0;
+	pair.second.cpu->_registers.x = 0xFF;
+	pair.second.wram->_data[0] = 0xFF;
+	pair.second.cpu->CPX(0x0);
+	cr_assert_eq(pair.second.cpu->_registers.p.z, true, "The zero flag should be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.n, false, "The negative flag should not be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.c, true, "The carry flag should be set");
+}
+
+Test(CPX, negative)
+{
+	auto pair = Init();
+	pair.second.cpu->_registers.p.x_b = true;
+	pair.second.cpu->_registers.p.flags = 0;
+	pair.second.cpu->_registers.x = 0x80;
+	pair.second.wram->_data[0] = 0xFF;
+	pair.second.cpu->CPX(0x0);
+	cr_assert_eq(pair.second.cpu->_registers.p.z, false, "The zero flag should not be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.n, true, "The negative flag should be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.c, false, "The carry flag should not be set");
+}
+
+Test(CPX, 16bits)
+{
+	auto pair = Init();
+	pair.second.cpu->_registers.p.flags = 0;
+	pair.second.cpu->_registers.p.x_b = false;
+	pair.second.cpu->_registers.x = 0x8888;
+	pair.second.wram->_data[0] = 0x88;
+	pair.second.wram->_data[1] = 0x98;
+	pair.second.cpu->CPX(0x0);
+	cr_assert_eq(pair.second.cpu->_registers.p.z, false, "The zero flag should not be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.n, true, "The negative flag should be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.c, false, "The carry flag should not be set");
+}
+
+Test(CPY, basic)
+{
+	auto pair = Init();
+	pair.second.cpu->_registers.p.x_b = true;
+	pair.second.cpu->_registers.p.flags = 0;
+	pair.second.cpu->_registers.y = 0xFF;
+	pair.second.wram->_data[0] = 0xFF;
+	pair.second.cpu->CPY(0x0);
+	cr_assert_eq(pair.second.cpu->_registers.p.z, true, "The zero flag should be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.n, false, "The negative flag should not be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.c, true, "The carry flag should be set");
+}
+
+Test(CPY, negative)
+{
+	auto pair = Init();
+	pair.second.cpu->_registers.p.x_b = true;
+	pair.second.cpu->_registers.p.flags = 0;
+	pair.second.cpu->_registers.y = 0x80;
+	pair.second.wram->_data[0] = 0xFF;
+	pair.second.cpu->CPY(0x0);
+	cr_assert_eq(pair.second.cpu->_registers.p.z, false, "The zero flag should not be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.n, true, "The negative flag should be set");
+	cr_assert_eq(pair.second.cpu->_registers.p.c, false, "The carry flag should not be set");
+}