Improved code consistency

src/x86/Div.go

@@ -6,9 +6,9 @@ import "git.akyoto.dev/cli/q/src/cpu"
 func DivRegister(code []byte, divisor cpu.Register) []byte {
 	rex := byte(0x48)
 
-	if divisor >= 8 {
+	if divisor > 0b111 {
 		rex++
-		divisor -= 8
+		divisor &= 0b111
 	}
 
 	return append(

src/x86/Pop.go

@@ -4,9 +4,9 @@ import "git.akyoto.dev/cli/q/src/cpu"
 
 // PopRegister pops a value from the stack and saves it into the register.
 func PopRegister(code []byte, register cpu.Register) []byte {
-	if register >= 8 {
+	if register > 0b111 {
 		code = append(code, REX(0, 0, 0, 1))
-		register -= 8
+		register &= 0b111
 	}
 
 	return append(

src/x86/Push.go

@@ -29,9 +29,9 @@ func PushNumber(code []byte, number int) []byte {
 
 // PushRegister pushes the value inside the register onto the stack.
 func PushRegister(code []byte, register cpu.Register) []byte {
-	if register >= 8 {
+	if register > 0b111 {
 		code = append(code, REX(0, 0, 0, 1))
-		register -= 8
+		register &= 0b111
 	}
 
 	return append(