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More code cleanup of STZ functions

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This commit is contained in:
Palindromic Bread Loaf
2025-07-28 12:29:02 -04:00
parent 015b039fff
commit edac91baf9
2 changed files with 15 additions and 30 deletions
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43
src/cpu.cpp
View File

@@ -497,6 +497,15 @@ void CPU::SBC_FromAddress_PageCross(const uint32_t address, const uint16_t base_
}
}
void CPU::STZ_ToAddress(const uint32_t address, const int base_cycles_8bit, const int base_cycles_16bit) {
if (P & FLAG_M) {
WriteByte(address, 0x00);
cycles += base_cycles_8bit;
} else {
WriteWord(address, 0x0000);
cycles += base_cycles_16bit;
}
}
void CPU::ExecuteInstruction() {
switch (const uint8_t opcode = bus->Read(PC++)) {
@@ -4606,13 +4615,7 @@ void CPU::STZ_Absolute() {
PC += 2;
const uint32_t full_address = (DB << 16) | address;
if (P & FLAG_M) {
WriteByte(full_address, 0x00);
cycles += 4;
} else {
WriteWord(full_address, 0x0000);
cycles += 5;
}
STZ_ToAddress(full_address, 4, 5);
}
void CPU::STZ_AbsoluteX() {
@@ -4621,27 +4624,14 @@ void CPU::STZ_AbsoluteX() {
const uint16_t x_offset = (P & FLAG_X) ? (X & 0xFF) : X;
const uint32_t address = (DB << 16) | (base_address + x_offset);
if (P & FLAG_M) {
WriteByte(address, 0x00);
cycles += 5;
} else {
WriteWord(address, 0x0000);
cycles += 6;
}
STZ_ToAddress(address, 5, 6);
}
void CPU::STZ_DirectPage() {
const uint8_t offset = ReadByte(PC++);
const uint32_t address = D + offset;
if (P & FLAG_M) {
WriteByte(address, 0x00);
cycles += 3;
} else {
WriteWord(address, 0x0000);
cycles += 4;
}
STZ_ToAddress(address, 3, 4);
if (D & 0xFF) cycles++;
}
@@ -4649,14 +4639,7 @@ void CPU::STZ_DirectPageX() {
const uint8_t offset = ReadByte(PC++);
const uint16_t x_offset = (P & FLAG_X) ? (X & 0xFF) : X;
const uint32_t address = D + offset + x_offset;
if (P & FLAG_M) {
WriteByte(address, 0x00);
cycles += 4;
} else {
WriteWord(address, 0x0000);
cycles += 5;
}
STZ_ToAddress(address, 4, 5);
if (D & 0xFF) cycles++;
}

2
src/cpu.h
View File

@@ -95,6 +95,8 @@ class CPU {
void SBC_FromAddress_PageCross(uint32_t address, uint16_t base_address, uint16_t offset, int base_cycles_8bit,
int base_cycles_16bit);
void STZ_ToAddress(uint32_t address, int base_cycles_8bit, int base_cycles_16bit);
public:
explicit CPU(Bus* memory_bus) : bus(memory_bus) {
Reset();