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izapple2
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Reorder execute.go

This commit is contained in:
Ivan Izaguirre 2019-01-29 00:06:15 +01:00
parent 858d6acac5
commit 195d9098a1
1 changed files with 45 additions and 45 deletions
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90
execute.go
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@ -31,50 +31,6 @@ func getWordInLine(line []uint8) uint16 {
return uint16(line[1]) + 0x100*uint16(line[2])
}
type opcode struct {
name string
bytes int
cycles int
action opFunc
}
type opFunc func(s *state, line []uint8, opcode opcode)
func opNOP(s *state, line []uint8, opcode opcode) {}
func buildOpTransfer(regSrc int, regDst int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
value := s.registers.getRegister(regSrc)
s.registers.setRegister(regDst, value)
if regDst != regSP {
s.registers.updateFlagZN(value)
}
}
}
func buildOpIncDec(addressMode int, inc bool) opFunc {
return func(s *state, line []uint8, opcode opcode) {
value, hasAddress, address, register := resolveWithAddressMode(s, line, addressMode)
if inc {
value++
} else {
value--
}
s.registers.updateFlagZN(value)
storeWhereNeeded(s, value, hasAddress, address, register)
}
}
func storeWhereNeeded(s *state, value uint8, hasAddress bool, address uint16, register int) {
if hasAddress {
s.memory[address] = value
} else if register != regNone {
s.registers.setRegister(register, value)
} else {
// Todo: assert impossible
}
}
func resolveWithAddressMode(s *state, line []uint8, addressMode int) (
value uint8, hasAddress bool, address uint16, register int) {
hasAddress = true
@ -121,6 +77,50 @@ func resolveWithAddressMode(s *state, line []uint8, addressMode int) (
return
}
func storeWhereResolved(s *state, value uint8, hasAddress bool, address uint16, register int) {
if hasAddress {
s.memory[address] = value
} else if register != regNone {
s.registers.setRegister(register, value)
} else {
// Todo: assert impossible
}
}
type opcode struct {
name string
bytes int
cycles int
action opFunc
}
type opFunc func(s *state, line []uint8, opcode opcode)
func opNOP(s *state, line []uint8, opcode opcode) {}
func buildOpTransfer(regSrc int, regDst int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
value := s.registers.getRegister(regSrc)
s.registers.setRegister(regDst, value)
if regDst != regSP {
s.registers.updateFlagZN(value)
}
}
}
func buildOpIncDec(addressMode int, inc bool) opFunc {
return func(s *state, line []uint8, opcode opcode) {
value, hasAddress, address, register := resolveWithAddressMode(s, line, addressMode)
if inc {
value++
} else {
value--
}
s.registers.updateFlagZN(value)
storeWhereResolved(s, value, hasAddress, address, register)
}
}
func buildRotate(addressMode int, isLeft bool) opFunc {
return func(s *state, line []uint8, opcode opcode) {
value, hasAddress, address, register := resolveWithAddressMode(s, line, addressMode)
@ -138,7 +138,7 @@ func buildRotate(addressMode int, isLeft bool) opFunc {
}
s.registers.updateFlag(flagC, carry)
s.registers.updateFlagZN(value)
storeWhereNeeded(s, value, hasAddress, address, register)
storeWhereResolved(s, value, hasAddress, address, register)
}
}