package codegen

import (
	"slices"

	"git.urbach.dev/cli/q/src/asm"
	"git.urbach.dev/cli/q/src/ssa"
)

func (f *Function) executeCas(step *Step, instr *ssa.Cas) {
	address := f.ValueToStep[instr.Arguments[0]]
	oldValue := f.ValueToStep[instr.Arguments[1]]
	newValue := f.ValueToStep[instr.Arguments[2]]
	live := slices.Concat(step.Live, []*Step{address, oldValue, newValue})
	addressRegister := f.resolveOperand(address, live)
	oldValueRegister := f.resolveOperand(oldValue, live, addressRegister)
	newValueRegister := f.resolveOperand(newValue, live, addressRegister, oldValueRegister)
	oldValueRegister = f.arch.casOldValue(f, oldValueRegister)

	f.Assembler.Append(&asm.CompareAndSwap{
		OldValue: oldValueRegister,
		NewValue: newValueRegister,
		Address:  addressRegister,
		Length:   8,
	})
}