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Clarify set/get difference; make interrupt flag storage private.

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This commit is contained in:
Thomas Harte
2025-10-28 17:32:10 -04:00
parent 55c59e6164
commit 5332bcd6b4
3 changed files with 61 additions and 54 deletions
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Processors/6502Mk2/Implementation/6502.hpp
+1 -1
View File
@@ -111,7 +111,7 @@ void Processor<model, Traits>::run_for(const Cycles cycles) {
) && registers.flags.decimal;
};
const auto set_interrupt_flag = [&] {
registers.flags.inverse_interrupt = 0;
registers.flags.template set_per<Flag::InverseInterrupt>(0);
if constexpr (is_65c02(model)) {
registers.flags.decimal = 0;
}
Processors/6502Mk2/Perform.hpp
+46 -46
View File
@@ -21,13 +21,13 @@ namespace Operations {
template <typename RegistersT>
void ane(RegistersT &registers, const uint8_t operand) {
registers.a = (registers.a | 0xee) & operand & registers.x;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
template <typename RegistersT>
void anc(RegistersT &registers, const uint8_t operand) {
registers.a &= operand;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
registers.flags.carry = registers.a >> 7;
}
@@ -38,7 +38,7 @@ void adc(RegistersT &registers, const uint8_t operand) {
if(!has_decimal_mode(model) || !registers.flags.decimal) {
registers.flags.set_overflow(result, registers.a, operand);
registers.flags.template set<Flag::NegativeZero>(registers.a = result);
registers.flags.template set_per<Flag::NegativeZero>(registers.a = result);
return;
}
@@ -80,7 +80,7 @@ void adc(RegistersT &registers, const uint8_t operand) {
registers.a = result;
if constexpr (is_65c02(model)) {
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
}
@@ -97,7 +97,7 @@ void sbc(RegistersT &registers, const uint8_t operand) {
// All flags are set based only on the decimal result.
registers.flags.carry = result < registers.a + registers.flags.carry;
if constexpr (!is_65c02(model)) {
registers.flags.template set<Flag::NegativeZero>(result);
registers.flags.template set_per<Flag::NegativeZero>(result);
}
registers.flags.set_overflow(result, registers.a, operand_complement);
@@ -128,7 +128,7 @@ void sbc(RegistersT &registers, const uint8_t operand) {
registers.a = result;
if constexpr (is_65c02(model)) {
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
}
@@ -137,7 +137,7 @@ void arr(RegistersT &registers, const uint8_t operand) {
registers.a &= operand;
const uint8_t unshifted_a = registers.a;
registers.a = uint8_t((registers.a >> 1) | (registers.flags.carry << 7));
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
registers.flags.overflow = (registers.a^(registers.a << 1))&Flag::Overflow;
if(registers.flags.decimal && has_decimal_mode(model)) {
@@ -154,14 +154,14 @@ void sbx(RegistersT &registers, const uint8_t operand) {
registers.x &= registers.a;
registers.flags.carry = operand <= registers.x;
registers.x -= operand;
registers.flags.template set<Flag::NegativeZero>(registers.x);
registers.flags.template set_per<Flag::NegativeZero>(registers.x);
}
template <typename RegistersT>
void asl(RegistersT &registers, uint8_t &operand) {
registers.flags.carry = operand >> 7;
operand <<= 1;
registers.flags.template set<Flag::NegativeZero>(operand);
registers.flags.template set_per<Flag::NegativeZero>(operand);
}
template <typename RegistersT>
@@ -169,14 +169,14 @@ void aso(RegistersT &registers, uint8_t &operand) {
registers.flags.carry = operand >> 7;
operand <<= 1;
registers.a |= operand;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
template <typename RegistersT>
void rol(RegistersT &registers, uint8_t &operand) {
const uint8_t temp8 = uint8_t((operand << 1) | registers.flags.carry);
registers.flags.carry = operand >> 7;
registers.flags.template set<Flag::NegativeZero>(operand = temp8);
registers.flags.template set_per<Flag::NegativeZero>(operand = temp8);
}
template <typename RegistersT>
@@ -185,14 +185,14 @@ void rla(RegistersT &registers, uint8_t &operand) {
registers.flags.carry = operand >> 7;
operand = temp8;
registers.a &= operand;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
template <typename RegistersT>
void lsr(RegistersT &registers, uint8_t &operand) {
registers.flags.carry = operand & 1;
operand >>= 1;
registers.flags.template set<Flag::NegativeZero>(operand);
registers.flags.template set_per<Flag::NegativeZero>(operand);
}
template <typename RegistersT>
@@ -200,7 +200,7 @@ void lse(RegistersT &registers, uint8_t &operand) {
registers.flags.carry = operand & 1;
operand >>= 1;
registers.a ^= operand;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
template <typename RegistersT>
@@ -208,14 +208,14 @@ void asr(RegistersT &registers, uint8_t &operand) {
registers.a &= operand;
registers.flags.carry = registers.a & 1;
registers.a >>= 1;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
}
template <typename RegistersT>
void ror(RegistersT &registers, uint8_t &operand) {
const uint8_t temp8 = uint8_t((operand >> 1) | (registers.flags.carry << 7));
registers.flags.carry = operand & 1;
registers.flags.template set<Flag::NegativeZero>(operand = temp8);
registers.flags.template set_per<Flag::NegativeZero>(operand = temp8);
}
template <Model model, typename RegistersT>
@@ -229,7 +229,7 @@ void rra(RegistersT &registers, uint8_t &operand) {
template <typename RegistersT>
void compare(RegistersT &registers, const uint8_t lhs, const uint8_t rhs) {
registers.flags.carry = rhs <= lhs;
registers.flags.template set<Flag::NegativeZero>(lhs - rhs);
registers.flags.template set_per<Flag::NegativeZero>(lhs - rhs);
}
template <typename RegistersT>
@@ -342,19 +342,19 @@ void perform(
// MARK: - Bitwise logic.
case Operation::ORA: registers.flags.template set<Flag::NegativeZero>(registers.a |= operand); break;
case Operation::AND: registers.flags.template set<Flag::NegativeZero>(registers.a &= operand); break;
case Operation::EOR: registers.flags.template set<Flag::NegativeZero>(registers.a ^= operand); break;
case Operation::ORA: registers.flags.template set_per<Flag::NegativeZero>(registers.a |= operand); break;
case Operation::AND: registers.flags.template set_per<Flag::NegativeZero>(registers.a &= operand); break;
case Operation::EOR: registers.flags.template set_per<Flag::NegativeZero>(registers.a ^= operand); break;
// MARK: - Loads and stores.
case Operation::LDA: registers.flags.template set<Flag::NegativeZero>(registers.a = operand); break;
case Operation::LDX: registers.flags.template set<Flag::NegativeZero>(registers.x = operand); break;
case Operation::LDY: registers.flags.template set<Flag::NegativeZero>(registers.y = operand); break;
case Operation::LAX: registers.flags.template set<Flag::NegativeZero>(registers.a = registers.x = operand); break;
case Operation::LDA: registers.flags.template set_per<Flag::NegativeZero>(registers.a = operand); break;
case Operation::LDX: registers.flags.template set_per<Flag::NegativeZero>(registers.x = operand); break;
case Operation::LDY: registers.flags.template set_per<Flag::NegativeZero>(registers.y = operand); break;
case Operation::LAX: registers.flags.template set_per<Flag::NegativeZero>(registers.a = registers.x = operand); break;
case Operation::LXA:
registers.a = registers.x = (registers.a | 0xee) & operand;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
break;
case Operation::PLP: registers.flags = Flags(operand); break;
@@ -365,40 +365,40 @@ void perform(
case Operation::SAX: operand = registers.a & registers.x; break;
case Operation::PHP: operand = static_cast<uint8_t>(registers.flags) | Flag::Break; break;
case Operation::CLC: registers.flags.carry = 0; break;
case Operation::CLI: registers.flags.inverse_interrupt = Flag::Interrupt; break;
case Operation::CLV: registers.flags.overflow = 0; break;
case Operation::CLD: registers.flags.decimal = 0; break;
case Operation::SEC: registers.flags.carry = Flag::Carry; break;
case Operation::SEI: registers.flags.inverse_interrupt = 0; break;
case Operation::SED: registers.flags.decimal = Flag::Decimal; break;
case Operation::CLC: registers.flags.carry = 0; break;
case Operation::CLI: registers.flags.template set_per<Flag::Interrupt>(0); break;
case Operation::CLV: registers.flags.overflow = 0; break;
case Operation::CLD: registers.flags.decimal = 0; break;
case Operation::SEC: registers.flags.carry = Flag::Carry; break;
case Operation::SEI: registers.flags.template set_per<Flag::Interrupt>(Flag::Interrupt); break;
case Operation::SED: registers.flags.decimal = Flag::Decimal; break;
case Operation::ANE: Operations::ane(registers, operand); break;
case Operation::ANC: Operations::anc(registers, operand); break;
case Operation::LAS:
registers.a = registers.x = registers.s = registers.s & operand;
registers.flags.template set<Flag::NegativeZero>(registers.a);
registers.flags.template set_per<Flag::NegativeZero>(registers.a);
break;
// MARK: - Transfers.
case Operation::TXA: registers.flags.template set<Flag::NegativeZero>(registers.a = registers.x); break;
case Operation::TYA: registers.flags.template set<Flag::NegativeZero>(registers.a = registers.y); break;
case Operation::TXA: registers.flags.template set_per<Flag::NegativeZero>(registers.a = registers.x); break;
case Operation::TYA: registers.flags.template set_per<Flag::NegativeZero>(registers.a = registers.y); break;
case Operation::TXS: registers.s = registers.x; break;
case Operation::TAY: registers.flags.template set<Flag::NegativeZero>(registers.y = registers.a); break;
case Operation::TAX: registers.flags.template set<Flag::NegativeZero>(registers.x = registers.a); break;
case Operation::TSX: registers.flags.template set<Flag::NegativeZero>(registers.x = registers.s); break;
case Operation::TAY: registers.flags.template set_per<Flag::NegativeZero>(registers.y = registers.a); break;
case Operation::TAX: registers.flags.template set_per<Flag::NegativeZero>(registers.x = registers.a); break;
case Operation::TSX: registers.flags.template set_per<Flag::NegativeZero>(registers.x = registers.s); break;
// MARK: - Increments and decrements.
case Operation::INC: registers.flags.template set<Flag::NegativeZero>(++operand); break;
case Operation::DEC: registers.flags.template set<Flag::NegativeZero>(--operand); break;
case Operation::INA: registers.flags.template set<Flag::NegativeZero>(++registers.a); break;
case Operation::DEA: registers.flags.template set<Flag::NegativeZero>(--registers.a); break;
case Operation::INX: registers.flags.template set<Flag::NegativeZero>(++registers.x); break;
case Operation::DEX: registers.flags.template set<Flag::NegativeZero>(--registers.x); break;
case Operation::INY: registers.flags.template set<Flag::NegativeZero>(++registers.y); break;
case Operation::DEY: registers.flags.template set<Flag::NegativeZero>(--registers.y); break;
case Operation::INC: registers.flags.template set_per<Flag::NegativeZero>(++operand); break;
case Operation::DEC: registers.flags.template set_per<Flag::NegativeZero>(--operand); break;
case Operation::INA: registers.flags.template set_per<Flag::NegativeZero>(++registers.a); break;
case Operation::DEA: registers.flags.template set_per<Flag::NegativeZero>(--registers.a); break;
case Operation::INX: registers.flags.template set_per<Flag::NegativeZero>(++registers.x); break;
case Operation::DEX: registers.flags.template set_per<Flag::NegativeZero>(--registers.x); break;
case Operation::INY: registers.flags.template set_per<Flag::NegativeZero>(++registers.y); break;
case Operation::DEY: registers.flags.template set_per<Flag::NegativeZero>(--registers.y); break;
// MARK: - Shifts and rolls.
Processors/6502Mk2/Registers.hpp
+14 -7
View File
@@ -102,7 +102,7 @@ struct Flags {
/// Sets a flag based on an 8-bit ALU result.
template <Flag flag>
requires(is_settable(flag))
void set(const uint8_t result) {
void set_per(const uint8_t result) {
switch(flag) {
default: __builtin_unreachable();
@@ -117,6 +117,12 @@ struct Flags {
}
}
template <Flag flag>
requires(is_settable(flag))
void set(const bool result) {
set_per<flag>(result ? 0xff : 0x00);
}
uint8_t carry_value() const {
return carry;
}
@@ -145,12 +151,12 @@ struct Flags {
}
Flags(const uint8_t flags) {
set<Flag::Carry>(flags);
set<Flag::Negative>(flags);
set<Flag::Zero>((~flags) & Flag::Zero);
set<Flag::Overflow>(flags);
set<Flag::Interrupt>(flags);
set<Flag::Decimal>(flags);
set_per<Flag::Carry>(flags);
set_per<Flag::Negative>(flags);
set_per<Flag::Zero>((~flags) & Flag::Zero);
set_per<Flag::Overflow>(flags);
set_per<Flag::Interrupt>(flags);
set_per<Flag::Decimal>(flags);
assert((flags | Flag::Always | Flag::Break) == static_cast<uint8_t>(*this));
}
@@ -164,6 +170,7 @@ struct Flags {
uint8_t carry = 0; /// Contains Flag::Carry.
uint8_t decimal = 0; /// Contains Flag::Decimal.
uint8_t overflow = 0; /// Contains Flag::Overflow.
private:
uint8_t inverse_interrupt = 0; /// Contains Flag::Interrupt, complemented.
};