revert redundant function: fetchM1x2

cpu.go

@@ -135,7 +135,7 @@ func (cpu *CPU) fetch16() uint16 {
 	return (uint16(h) << 8) | uint16(l)
 }
 
-// fetchM1 fetches a byte for M1 cycle
+// fetchM1 fetches a byte for M1 cycle.
 func (cpu *CPU) fetchM1() uint8 {
 	c := cpu.Memory.Get(cpu.PC)
 	cpu.PC++
@@ -145,19 +145,6 @@ func (cpu *CPU) fetchM1() uint8 {
 	return c
 }
 
-// fetchM1x2 fetches two bytes for M1 cycle.
-// First one is a data, second one is a part of opcode.
-func (cpu *CPU) fetchM1x2() (d, c uint8) {
-	d = cpu.Memory.Get(cpu.PC)
-	cpu.PC++
-	c = cpu.Memory.Get(cpu.PC)
-	cpu.PC++
-	// increment refresh counter
-	rc := cpu.IR.Lo
-	cpu.IR.Lo = rc&0x80 | (rc+1)&0x7f
-	return d, c
-}
-
 func (cpu *CPU) ioIn(addr uint8) uint8 {
 	if cpu.IO == nil {
 		return 0

operation.go

@@ -1537,7 +1537,7 @@ func (cpu *CPU) executeOne() {
 			oopLDSPIX(cpu)
 
 		case 0xcb:
-			switch d, c3 := cpu.fetchM1x2(); c3 {
+			switch d, c3 := cpu.fetch(), cpu.fetchM1(); c3 {
 
 			case 0x06:
 				oopRLCIXdP(cpu, d)
@@ -2144,7 +2144,7 @@ func (cpu *CPU) executeOne() {
 			oopLDSPIY(cpu)
 
 		case 0xcb:
-			switch d, c3 := cpu.fetchM1x2(); c3 {
+			switch d, c3 := cpu.fetch(), cpu.fetchM1(); c3 {
 
 			case 0x06:
 				oopRLCIYdP(cpu, d)