mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2025-01-10 10:29:43 +00:00
First step of moving to an instruction decoder, rather than a lookup table.
Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
This commit is contained in:
Adrian.Conlon
parent
9a264c7c06
commit
8f18a128cd
@ -43,17 +43,9 @@ namespace EightBit {
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virtual register16_t& DE() override { return de; }
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virtual register16_t& HL() override { return hl; }
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bool isInterruptable() const {
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return m_interrupt;
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}
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bool isInterruptable() const;
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int interrupt(uint8_t value) {
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if (isInterruptable()) {
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di();
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return execute(value);
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}
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return 0;
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}
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int interrupt(uint8_t value);
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virtual void initialise();
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int step();
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@ -72,11 +64,7 @@ namespace EightBit {
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int execute(uint8_t opcode);
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int execute(const Instruction& instruction) {
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cycles = 0;
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instruction.vector();
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return cycles + instruction.count;
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}
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int execute(const Instruction& instruction);
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void adjustReservedFlags() {
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F() = (F() | Bit1) & ~(Bit5 | Bit3);
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@ -90,15 +78,9 @@ namespace EightBit {
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clearFlag(f, AC, calculateHalfCarrySub(before, value, calculation));
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}
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static void increment(uint8_t& f, uint8_t& operand) {
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adjustSZP<Intel8080>(f, ++operand);
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clearFlag(f, AC, lowNibble(operand));
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}
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static void increment(uint8_t& f, uint8_t& operand);
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static void decrement(uint8_t& f, uint8_t& operand) {
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adjustSZP<Intel8080>(f, --operand);
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setFlag(f, AC, lowNibble(operand) != Mask4);
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}
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static void decrement(uint8_t& f, uint8_t& operand);
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static Instruction INS(instruction_t method, AddressingMode mode, std::string disassembly, int cycles);
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Instruction UNKNOWN();
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@ -107,68 +89,18 @@ namespace EightBit {
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//
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void compare(uint8_t& f, uint8_t check, uint8_t value) {
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subtract(f, check, value);
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}
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void compare(uint8_t& f, uint8_t check, uint8_t value);
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void anda(uint8_t value);
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void ora(uint8_t value);
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void xra(uint8_t value);
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void anda(uint8_t value) {
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auto& a = A();
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auto& f = F();
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setFlag(f, AC, (a | value) & Bit3);
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clearFlag(f, CF);
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adjustSZP<Intel8080>(f, a &= value);
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}
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void add(uint8_t value, int carry = 0);
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void adc(uint8_t value);
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void ora(uint8_t value) {
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auto& f = F();
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clearFlag(f, AC | CF);
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adjustSZP<Intel8080>(f, A() |= value);
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}
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void dad(uint16_t value);
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void xra(uint8_t value) {
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auto& f = F();
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clearFlag(f, AC | CF);
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adjustSZP<Intel8080>(f, A() ^= value);
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}
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void add(uint8_t value, int carry = 0) {
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auto& a = A();
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auto& f = F();
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register16_t sum;
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sum.word = a + value + carry;
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adjustAuxiliaryCarryAdd(f, a, value, sum.word);
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a = sum.low;
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setFlag(f, CF, sum.word & Bit8);
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adjustSZP<Intel8080>(f, a);
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}
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void adc(uint8_t value) {
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add(value, F() & CF);
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}
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void dad(uint16_t value) {
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auto& f = F();
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auto sum = HL().word + value;
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setFlag(f, CF, sum & Bit16);
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HL().word = sum;
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}
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void subtract(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0) {
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register16_t result;
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result.word = operand - value - carry;
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adjustAuxiliaryCarrySub(f, operand, value, result.word);
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operand = result.low;
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setFlag(f, CF, result.word & Bit8);
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adjustSZP<Intel8080>(f, operand);
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}
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void sbb(uint8_t value) {
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subtract(F(), A(), value, F() & CF);
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}
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void subtract(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
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void sbb(uint8_t value);
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void mov_m_r(uint8_t value) {
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m_memory.ADDRESS() = HL();
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@ -332,16 +264,7 @@ namespace EightBit {
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adjustReservedFlags();
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}
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void xhtl() {
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m_memory.ADDRESS() = SP();
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MEMPTR().low = m_memory.reference();
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m_memory.reference() = L();
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L() = MEMPTR().low;
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m_memory.ADDRESS().word++;
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MEMPTR().high = m_memory.reference();
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m_memory.reference() = H();
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H() = MEMPTR().high;
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}
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void xhtl();
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void sphl() {
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SP() = HL();
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@ -356,56 +279,51 @@ namespace EightBit {
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// jump
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void jmp() { jumpConditional(true); }
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void jmp();
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void jc() { jumpConditional(F() & CF); }
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void jnc() { jumpConditional(!(F() & CF)); }
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void jc();
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void jnc();
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void jz() { jumpConditional(F() & ZF); }
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void jnz() { jumpConditional(!(F() & ZF)); }
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void jz();
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void jnz();
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void jpe() { jumpConditional(F() & PF); }
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void jpo() { jumpConditional(!(F() & PF)); }
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void jpe();
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void jpo();
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void jm() { jumpConditional(F() & SF); }
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void jp() { jumpConditional(!(F() & SF)); }
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void jm();
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void jp();
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void pchl() {
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PC() = HL();
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}
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void pchl();
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// call
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void callDirect() {
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fetchWord();
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call();
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}
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void callDirect();
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void cc() { if (callConditional(F() & CF)) cycles += 6; }
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void cnc() { if (callConditional(!(F() & CF))) cycles += 6; }
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void cc();
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void cnc();
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void cpe() { if (callConditional(F() & PF)) cycles += 6; }
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void cpo() { if (callConditional(!(F() & PF))) cycles += 6; }
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void cpe();
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void cpo();
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void cz() { if (callConditional(F() & ZF)) cycles += 6; }
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void cnz() { if (callConditional(!(F() & ZF))) cycles += 6; }
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void cz();
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void cnz();
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void cm() { if (callConditional(F() & SF)) cycles += 6; }
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void cp() { if (callConditional(!(F() & SF))) cycles += 6; }
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void cm();
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void cp();
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// return
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void rc() { if (returnConditional(F() & CF)) cycles += 6; }
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void rnc() { if (returnConditional(!(F() & CF))) cycles += 6; }
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void rc();
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void rnc();
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void rz() { if (returnConditional(F() & ZF)) cycles += 6; }
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void rnz() { if (returnConditional(!(F() & ZF))) cycles += 6; }
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void rz();
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void rnz();
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void rpe() { if (returnConditional(F() & PF)) cycles += 6; }
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void rpo() { if (returnConditional(!(F() & PF))) cycles += 6; }
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void rpe();
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void rpo();
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void rm() { if (returnConditional(F() & SF)) cycles += 6; }
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void rp() { if (returnConditional(!(F() & SF))) cycles += 6; }
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void rm();
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void rp();
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// restart
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@ -591,67 +509,27 @@ namespace EightBit {
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// rotate
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void rlc() {
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auto& a = A();
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auto carry = a & Bit7;
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a = (a << 1) | (carry >> 7);
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setFlag(F(), CF, carry);
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}
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void rrc() {
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auto& a = A();
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auto carry = a & Bit0;
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a = (a >> 1) | (carry << 7);
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setFlag(F(), CF, carry);
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}
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void ral() {
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auto& a = A();
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auto& f = F();
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const auto carry = f & CF;
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setFlag(f, CF, a & Bit7);
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a = (a << 1) | carry;
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}
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void rar() {
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auto& a = A();
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auto& f = F();
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const auto carry = f & CF;
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setFlag(f, CF, a & Bit0);
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a = (a >> 1) | (carry << 7);
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}
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void rlc();
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void rrc();
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void ral();
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void rar();
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// specials
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void cma() { A() ^= Mask8; }
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void stc() { setFlag(F(), CF); }
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void cmc() { clearFlag(F(), CF, F() & CF); }
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void daa() {
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const auto& a = A();
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auto& f = F();
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auto carry = f & CF;
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uint8_t addition = 0;
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if ((f & AC) || lowNibble(a) > 9) {
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addition = 0x6;
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}
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if ((f & CF) || highNibble(a) > 9 || (highNibble(a) >= 9 && lowNibble(a) > 9)) {
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addition |= 0x60;
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carry = true;
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}
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add(addition);
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setFlag(f, CF, carry);
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}
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void cma();
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void stc();
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void cmc();
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void daa();
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// input/output
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void out() { m_ports.write(fetchByte(), A()); }
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void in() { A() = m_ports.read(fetchByte()); }
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void out();
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void in();
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// control
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void ei() { m_interrupt = true; }
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void di() { m_interrupt = false; }
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void ei();
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void di();
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void nop() {}
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@ -62,6 +62,329 @@ void EightBit::Intel8080::initialise() {
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AF().word = BC().word = DE().word = HL().word = 0;
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}
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#pragma region Interrupt routines
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void EightBit::Intel8080::di() {
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m_interrupt = false;
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}
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void EightBit::Intel8080::ei() {
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m_interrupt = true;
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}
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int EightBit::Intel8080::interrupt(uint8_t value) {
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if (isInterruptable()) {
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di();
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return execute(value);
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}
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return 0;
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}
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bool EightBit::Intel8080::isInterruptable() const {
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return m_interrupt;
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}
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#pragma endregion Interrupt routines
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#pragma region Flag manipulation helpers
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void EightBit::Intel8080::increment(uint8_t& f, uint8_t& operand) {
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adjustSZP<Intel8080>(f, ++operand);
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clearFlag(f, AC, lowNibble(operand));
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}
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void EightBit::Intel8080::decrement(uint8_t& f, uint8_t& operand) {
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adjustSZP<Intel8080>(f, --operand);
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setFlag(f, AC, lowNibble(operand) != Mask4);
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}
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#pragma endregion Flag manipulation helpers
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#pragma region PC manipulation: call/ret/jp/jr
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void EightBit::Intel8080::jmp() {
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jumpConditional(true);
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}
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void EightBit::Intel8080::jc() {
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jumpConditional(F() & CF);
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}
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void EightBit::Intel8080::jnc() {
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jumpConditional(!(F() & CF));
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}
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void EightBit::Intel8080::jz() {
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jumpConditional(F() & ZF);
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}
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void EightBit::Intel8080::jnz() {
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jumpConditional(!(F() & ZF));
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}
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void EightBit::Intel8080::jpe() {
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jumpConditional(F() & PF);
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}
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void EightBit::Intel8080::jpo() {
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jumpConditional(!(F() & PF));
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}
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void EightBit::Intel8080::jm() {
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jumpConditional(F() & SF);
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}
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void EightBit::Intel8080::jp() {
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jumpConditional(!(F() & SF));
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}
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void EightBit::Intel8080::pchl() {
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PC() = HL();
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}
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void EightBit::Intel8080::rc() {
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if (returnConditional(F() & CF))
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cycles += 6;
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}
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void EightBit::Intel8080::rnc() {
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if (returnConditional(!(F() & CF)))
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cycles += 6;
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}
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void EightBit::Intel8080::rz() {
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if (returnConditional(F() & ZF))
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cycles += 6;
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}
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void EightBit::Intel8080::rnz() {
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if (returnConditional(!(F() & ZF)))
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cycles += 6;
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}
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void EightBit::Intel8080::rpe() {
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if (returnConditional(F() & PF))
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cycles += 6;
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}
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void EightBit::Intel8080::rpo() {
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if (returnConditional(!(F() & PF)))
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cycles += 6;
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}
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void EightBit::Intel8080::rm() {
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if (returnConditional(F() & SF))
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cycles += 6;
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}
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void EightBit::Intel8080::rp() {
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if (returnConditional(!(F() & SF)))
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cycles += 6;
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}
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void EightBit::Intel8080::callDirect() {
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fetchWord();
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call();
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}
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void EightBit::Intel8080::cc() {
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if (callConditional(F() & CF))
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cycles += 6;
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}
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void EightBit::Intel8080::cnc() {
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if (callConditional(!(F() & CF)))
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cycles += 6;
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}
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void EightBit::Intel8080::cpe() {
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if (callConditional(F() & PF))
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cycles += 6;
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}
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void EightBit::Intel8080::cpo() {
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if (callConditional(!(F() & PF)))
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cycles += 6;
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}
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void EightBit::Intel8080::cz() {
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if (callConditional(F() & ZF))
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cycles += 6;
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}
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void EightBit::Intel8080::cnz() {
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if (callConditional(!(F() & ZF)))
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cycles += 6;
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}
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void EightBit::Intel8080::cm() {
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if (callConditional(F() & SF))
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cycles += 6;
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}
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void EightBit::Intel8080::cp() {
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if (callConditional(!(F() & SF)))
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cycles += 6;
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}
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#pragma endregion PC manipulation: call/ret/jp/jr
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#pragma region 16-bit arithmetic
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void EightBit::Intel8080::dad(uint16_t value) {
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auto& f = F();
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auto sum = HL().word + value;
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setFlag(f, CF, sum & Bit16);
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HL().word = sum;
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}
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#pragma endregion 16-bit arithmetic
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#pragma region ALU
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void EightBit::Intel8080::add(uint8_t value, int carry) {
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auto& a = A();
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auto& f = F();
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register16_t sum;
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sum.word = a + value + carry;
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adjustAuxiliaryCarryAdd(f, a, value, sum.word);
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a = sum.low;
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setFlag(f, CF, sum.word & Bit8);
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adjustSZP<Intel8080>(f, a);
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}
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void EightBit::Intel8080::adc(uint8_t value) {
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add(value, F() & CF);
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}
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void EightBit::Intel8080::subtract(uint8_t& f, uint8_t& operand, uint8_t value, int carry) {
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register16_t result;
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result.word = operand - value - carry;
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adjustAuxiliaryCarrySub(f, operand, value, result.word);
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operand = result.low;
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setFlag(f, CF, result.word & Bit8);
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adjustSZP<Intel8080>(f, operand);
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}
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void EightBit::Intel8080::sbb(uint8_t value) {
|
||||
subtract(F(), A(), value, F() & CF);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::anda(uint8_t value) {
|
||||
auto& a = A();
|
||||
auto& f = F();
|
||||
setFlag(f, AC, (a | value) & Bit3);
|
||||
clearFlag(f, CF);
|
||||
adjustSZP<Intel8080>(f, a &= value);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::xra(uint8_t value) {
|
||||
auto& f = F();
|
||||
clearFlag(f, AC | CF);
|
||||
adjustSZP<Intel8080>(f, A() ^= value);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::ora(uint8_t value) {
|
||||
auto& f = F();
|
||||
clearFlag(f, AC | CF);
|
||||
adjustSZP<Intel8080>(f, A() |= value);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::compare(uint8_t& f, uint8_t check, uint8_t value) {
|
||||
subtract(f, check, value);
|
||||
}
|
||||
|
||||
#pragma endregion ALU
|
||||
|
||||
#pragma region Shift and rotate
|
||||
|
||||
void EightBit::Intel8080::rlc() {
|
||||
auto& a = A();
|
||||
auto carry = a & Bit7;
|
||||
a = (a << 1) | (carry >> 7);
|
||||
setFlag(F(), CF, carry);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::rrc() {
|
||||
auto& a = A();
|
||||
auto carry = a & Bit0;
|
||||
a = (a >> 1) | (carry << 7);
|
||||
setFlag(F(), CF, carry);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::ral() {
|
||||
auto& a = A();
|
||||
auto& f = F();
|
||||
const auto carry = f & CF;
|
||||
setFlag(f, CF, a & Bit7);
|
||||
a = (a << 1) | carry;
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::rar() {
|
||||
auto& a = A();
|
||||
auto& f = F();
|
||||
const auto carry = f & CF;
|
||||
setFlag(f, CF, a & Bit0);
|
||||
a = (a >> 1) | (carry << 7);
|
||||
}
|
||||
|
||||
#pragma endregion Shift and rotate
|
||||
|
||||
#pragma region Miscellaneous instructions
|
||||
|
||||
void EightBit::Intel8080::daa() {
|
||||
const auto& a = A();
|
||||
auto& f = F();
|
||||
auto carry = f & CF;
|
||||
uint8_t addition = 0;
|
||||
if ((f & AC) || lowNibble(a) > 9) {
|
||||
addition = 0x6;
|
||||
}
|
||||
if ((f & CF) || highNibble(a) > 9 || (highNibble(a) >= 9 && lowNibble(a) > 9)) {
|
||||
addition |= 0x60;
|
||||
carry = true;
|
||||
}
|
||||
add(addition);
|
||||
setFlag(f, CF, carry);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::cma() {
|
||||
A() ^= Mask8;
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::stc() {
|
||||
setFlag(F(), CF);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::cmc() {
|
||||
clearFlag(F(), CF, F() & CF);
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::xhtl() {
|
||||
m_memory.ADDRESS() = SP();
|
||||
MEMPTR().low = m_memory.reference();
|
||||
m_memory.reference() = L();
|
||||
L() = MEMPTR().low;
|
||||
m_memory.ADDRESS().word++;
|
||||
MEMPTR().high = m_memory.reference();
|
||||
m_memory.reference() = H();
|
||||
H() = MEMPTR().high;
|
||||
}
|
||||
|
||||
#pragma endregion Miscellaneous instructions
|
||||
|
||||
void EightBit::Intel8080::out() {
|
||||
m_ports.write(fetchByte(), A());
|
||||
}
|
||||
|
||||
void EightBit::Intel8080::in() {
|
||||
A() = m_ports.read(fetchByte());
|
||||
}
|
||||
|
||||
int EightBit::Intel8080::step() {
|
||||
ExecutingInstruction.fire(*this);
|
||||
return execute(fetchByte());
|
||||
@ -72,6 +395,12 @@ int EightBit::Intel8080::execute(uint8_t opcode) {
|
||||
return execute(instruction);
|
||||
}
|
||||
|
||||
int EightBit::Intel8080::execute(const Instruction& instruction) {
|
||||
cycles = 0;
|
||||
instruction.vector();
|
||||
return cycles + instruction.count;
|
||||
}
|
||||
|
||||
//
|
||||
|
||||
void EightBit::Intel8080::___() {
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user