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chore: Implement exec of RLC and RRC

This commit is contained in:
Rekai Nyangadzayi Musuka 2020-09-07 22:34:09 -05:00
parent a4b3da1939
commit 7edffb166d
1 changed files with 97 additions and 10 deletions
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107
src/instruction.rs
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@ -400,13 +400,13 @@ impl Instruction {
let mut flags: Flags = cpu.register(Register::Flag).into();
let a = cpu.register(Register::A);
let cache = a >> 7; // get the 7th bit (this will be the carry bit + the one that is wrapped around)
let rot_a = (a << 1) | (cache << 0); // (rotate a left), then set the first bit (which will be a 0 by default)
let msb = a >> 7;
let rot_a = a.rotate_left(1);
flags.z = false;
flags.n = false;
flags.h = false;
flags.c = cache == 0x01;
flags.c = msb == 0x01;
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
@ -417,13 +417,13 @@ impl Instruction {
let mut flags: Flags = cpu.register(Register::Flag).into();
let a = cpu.register(Register::A);
let cache = a & 0x01; // RLCA but the other way around
let rot_a = (a >> 1) | (cache << 7);
let lsb = a & 0x01;
let rot_a = a.rotate_right(1);
flags.z = false;
flags.n = false;
flags.h = false;
flags.c = cache == 0x01;
flags.c = lsb == 0x01;
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
@ -434,13 +434,13 @@ impl Instruction {
let mut flags: Flags = cpu.register(Register::Flag).into();
let a = cpu.register(Register::A);
let cache = a >> 7;
let msb = a >> 7;
let rot_a = (a << 1) | ((flags.c as u8) << 0);
flags.z = false;
flags.n = false;
flags.h = false;
flags.c = cache == 0x01;
flags.c = msb == 0x01;
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
@ -451,13 +451,13 @@ impl Instruction {
let mut flags: Flags = cpu.register(Register::Flag).into();
let a = cpu.register(Register::A);
let cache = a & 0x01;
let lsb = a & 0x01;
let rot_a = (a >> 1) | ((flags.c as u8) << 7);
flags.z = false;
flags.n = false;
flags.h = false;
flags.c = cache == 0x01;
flags.c = lsb == 0x01;
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
@ -1027,7 +1027,94 @@ impl Instruction {
cpu.set_register_pair(RegisterPair::PC, 0x0000 + (n as u16));
Cycles(16)
}
Instruction::RLC(reg) => {
let mut flags: Flags = cpu.register(Register::Flag).into();
let carry_flag;
let result;
let cycles: Cycles;
match reg {
InstrRegister::B
| InstrRegister::C
| InstrRegister::D
| InstrRegister::E
| InstrRegister::H
| InstrRegister::L
| InstrRegister::A => {
let register = Register::try_from(reg).unwrap();
let value = cpu.register(register);
carry_flag = value >> 7 == 0x01;
result = value.rotate_left(1);
cpu.set_register(register, result);
cycles = Cycles(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let value = cpu.read_byte(addr);
carry_flag = value >> 7 == 0x01;
result = value.rotate_left(1);
cpu.write_byte(addr, result);
cycles = Cycles(16);
}
InstrRegister::IndirectC => unreachable!(),
}
flags.z = result == 0;
flags.n = false;
flags.h = false;
flags.c = carry_flag;
cpu.set_register(Register::Flag, flags.into());
cycles
}
Instruction::RRC(reg) => {
let mut flags: Flags = cpu.register(Register::Flag).into();
let carry_flag;
let result;
let cycles: Cycles;
match reg {
InstrRegister::B
| InstrRegister::C
| InstrRegister::D
| InstrRegister::E
| InstrRegister::H
| InstrRegister::L
| InstrRegister::A => {
let register = Register::try_from(reg).unwrap();
let value = cpu.register(register);
carry_flag = value & 0x01 == 0x01;
result = value.rotate_right(1);
cpu.set_register(register, result);
cycles = Cycles(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let value = cpu.read_byte(addr);
carry_flag = value & 0x01 == 0x01;
result = value.rotate_right(1);
cpu.write_byte(addr, result);
cycles = Cycles(16);
}
InstrRegister::IndirectC => unreachable!(),
}
flags.z = result == 0;
flags.n = false;
flags.h = false;
flags.c = carry_flag;
cpu.set_register(Register::Flag, flags.into());
cycles
}
_ => unimplemented!(),
}
}