op_bitop.go

package z80

func (cpu *CPU) bitchk8b(b, v uint8) {
	var nand uint8 = maskS53 | maskZ | maskH | maskPV | maskN
	var or uint8
	if v&(0x01<<b) == 0 {
		or |= maskZ | maskPV
	} else if b == 7 {
		or |= maskS
	}
	or |= maskH
	cpu.AF.Lo = cpu.AF.Lo&^nand | or
	cpu.LastOpCycles = 12
}

func xopBITbIXdP(cpu *CPU, b, d uint8) {
	p := addrOff(cpu.IX, d)
	v := cpu.Memory.Get(p)
	cpu.bitchk8b(b, v)
	cpu.LastOpCycles = 20
}

func xopBITbIYdP(cpu *CPU, b, d uint8) {
	p := addrOff(cpu.IY, d)
	v := cpu.Memory.Get(p)
	cpu.bitchk8b(b, v)
	cpu.LastOpCycles = 20
}

func xopSETbIXdP(cpu *CPU, b, d uint8) {
	p := addrOff(cpu.IX, d)
	v := cpu.Memory.Get(p)
	v = cpu.bitset8(b, v)
	cpu.Memory.Set(p, v)
	cpu.LastOpCycles = 23
}

func xopSETbIYdP(cpu *CPU, b, d uint8) {
	p := addrOff(cpu.IY, d)
	v := cpu.Memory.Get(p)
	v = cpu.bitset8(b, v)
	cpu.Memory.Set(p, v)
	cpu.LastOpCycles = 23
}

func xopRESbIXdP(cpu *CPU, b, d uint8) {
	p := addrOff(cpu.IX, d)
	v := cpu.Memory.Get(p)
	v = cpu.bitres8(b, v)
	cpu.Memory.Set(p, v)
	cpu.LastOpCycles = 23
}

func xopRESbIYdP(cpu *CPU, b, d uint8) {
	p := addrOff(cpu.IY, d)
	v := cpu.Memory.Get(p)
	v = cpu.bitres8(b, v)
	cpu.Memory.Set(p, v)
	cpu.LastOpCycles = 23
}

func xopBITbHLP(cpu *CPU, b uint8) {
	p := cpu.HL.U16()
	x := cpu.Memory.Get(p)
	x = cpu.bitres8(b, x)
	cpu.Memory.Set(p, x)
	cpu.LastOpCycles = 15
}

func xopSETbHLP(cpu *CPU, b uint8) {
	p := cpu.HL.U16()
	x := cpu.Memory.Get(p)
	x = cpu.bitset8(b, x)
	cpu.Memory.Set(p, x)
	cpu.LastOpCycles = 15
}