package asm

import "git.akyoto.dev/cli/q/src/build/cpu"

// unnecessary returns true if the register/register operation can be skipped.
func (a *Assembler) unnecessary(mnemonic Mnemonic, left cpu.Register, right cpu.Register) bool {
	if mnemonic == MOVE && left == right {
		return true
	}

	if len(a.Instructions) == 0 {
		return false
	}

	last := a.Instructions[len(a.Instructions)-1]

	if mnemonic == MOVE && last.Mnemonic == MOVE {
		data, isRegReg := last.Data.(*RegisterRegister)

		if !isRegReg {
			return false
		}

		if data.Destination == left && data.Source == right {
			return true
		}

		if data.Destination == right && data.Source == left {
			return true
		}
	}

	return false
}