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decoder - Add parenthesis to bitwise ANDs

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== has priority over & so a & b == c is parsed as a & (b == c)
This commit is contained in:
madmaurice 2023-08-28 22:31:52 +02:00
parent eb6faab89f
commit bd2b577c6c
1 changed files with 21 additions and 24 deletions
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45
cpu/decoder.cpp
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@ -9,10 +9,13 @@ static inline u16 make_u16(u8 msb, u8 lsb)
void Cpu::executeInstruction()
{
u16 currentpc = state.PC;
opcode_t op = readPC8();
int mcycles = 1;
if ((op & 0xC0 == 0x40) && op != 0x76) // LD r, r'
printf("@0x%04x: opcode %02X\n",currentpc,op);
if ((op & 0xC0) == 0x40 && op != 0x76) // LD r, r'
{
u8 tmp;
switch(op & 0x07)
@ -39,7 +42,7 @@ void Cpu::executeInstruction()
case 0x7: state.A = tmp; break;
}
}
else if(op & 0xC7 == 0x06) // LD r, n
else if((op & 0xC7) == 0x06) // LD r, n
{
u8 imm = readPC8();
@ -55,7 +58,7 @@ void Cpu::executeInstruction()
case 0x7: state.A = imm; break;
}
}
else if(op & 0xC7 == 0x46 && op != 0x76) // LD r, [HL]
else if((op & 0xC7) == 0x46 && op != 0x76) // LD r, [HL]
{
u8 data = bus->read8(state.HL);
@ -70,7 +73,7 @@ void Cpu::executeInstruction()
case 0x7: state.A = data; break;
}
}
else if(op & 0xC8 == 0x70 && op != 0x76) // LD [HL], r
else if((op & 0xC8) == 0x70 && op != 0x76) // LD [HL], r
{
u8 data;
switch(op & 0x7)
@ -86,7 +89,7 @@ void Cpu::executeInstruction()
bus->write8(state.HL, data);
}
else if(op & 0xCF == 0x01) // LD rr, nn
else if((op & 0xCF) == 0x01) // LD rr, nn
{
u16 data = readPC16();
@ -100,7 +103,7 @@ void Cpu::executeInstruction()
mcycles = 3;
}
else if(op & 0xCF == 0xC5) // PUSH rr
else if((op & 0xCF) == 0xC5) // PUSH rr
{
u16 data;
switch((op >> 4) & 0x3)
@ -117,7 +120,7 @@ void Cpu::executeInstruction()
mcycles = 4;
}
else if(op & 0xCF == 0xC1) // POP rr
else if((op & 0xCF) == 0xC1) // POP rr
{
u16 data = bus->read16(state.SP);
@ -133,7 +136,7 @@ void Cpu::executeInstruction()
mcycles = 4;
}
else if(op & 0xC0 == 0x80) // ADD, ADC, SUB, ABC, CP, AND, OR, XOR
else if((op & 0xC0) == 0x80) // ADD, ADC, SUB, ABC, CP, AND, OR, XOR
{
// SUB r: 0b10010xxx
// CP r: 0b10111xxx
@ -155,7 +158,7 @@ void Cpu::executeInstruction()
aluop8(aluop, rhs);
}
else if(op & 0xC6 == 0x04) // INC r; INC [HL]; DEC r; DEC [HL];
else if((op & 0xC6) == 0x04) // INC r; INC [HL]; DEC r; DEC [HL];
{
AluOp aluop = (op & 0x1) ? SUB : ADD;
@ -180,7 +183,7 @@ void Cpu::executeInstruction()
}
}
else if(op & 0xE7 == 0xC2) // JP cc, nn:
else if((op & 0xE7) == 0xC2) // JP cc, nn:
{
u16 nn = readPC16();
@ -194,7 +197,7 @@ void Cpu::executeInstruction()
mcycles = 3;
}
}
else if(op & 0xE7 == 0x20) // JR cc, e
else if((op & 0xE7) == 0x20) // JR cc, e
{
s8 e = readPC8();
@ -209,7 +212,7 @@ void Cpu::executeInstruction()
mcycles = 2;
}
}
else if(op & 0xE7 == 0xC4) // CALL cc, nn
else if((op & 0xE7) == 0xC4) // CALL cc, nn
{
u16 nn = readPC16();
@ -223,7 +226,7 @@ void Cpu::executeInstruction()
mcycles = 3;
}
}
else if(op & 0xE7 == 0xC0) // RET cc
else if((op & 0xE7) == 0xC0) // RET cc
{
if(decodeCond((op >> 3) & 0x3))
{
@ -235,7 +238,7 @@ void Cpu::executeInstruction()
mcycles = 2;
}
}
else if(op & 0xC7 == 0xC7) // RST
else if((op & 0xC7) == 0xC7) // RST
{
u16 rst_addr = op & 0x38;
doCall(rst_addr);
@ -284,18 +287,12 @@ void Cpu::executeInstruction()
mcycles = 2;
break;
case 0xF0: // LD A, [0xFF : n]
{
u8 n = readPC8();
state.A = bus->read8(make_u16(0xFFu,n));
mcycles = 3;
}
state.A = bus->read8(make_u16(0xFFu,readPC8()));
mcycles = 3;
break;
case 0xE0: // LD [0xFF : n], A
{
u8 n = readPC8();
bus->write8(make_u16(0xFFu,n), state.A);
mcycles = 3;
}
bus->write8(make_u16(0xFFu,readPC8()), state.A);
mcycles = 3;
break;
case 0x3A: // LD A, [HL-]
state.A = bus->read8(state.HL); state.HL--; mcycles = 2; break;