22 lines
1.2 KiB
Ruby
22 lines
1.2 KiB
Ruby
module Register
|
|
class ReturnImplementation
|
|
def run block
|
|
block.codes.dup.each do |code|
|
|
next unless code.is_a? Virtual::MethodReturn
|
|
new_codes = []
|
|
# move the current message to new_message
|
|
new_codes << RegisterMachine.instance.mov( Slot.MESSAGE_REGISTER , Slot::NEW_MESSAGE_REGISTER )
|
|
# and restore the message from saved value in new_message
|
|
new_codes << RegisterMachine.instance.ldr( Slot.MESSAGE_REGISTER ,Slot.NEW_MESSAGE_REGISTER , Virtual::Slot::MESSAGE_CALLER )
|
|
# "roll out" self and frame into their registers
|
|
new_codes << RegisterMachine.instance.ldr( Slot.SELF_REGISTER ,Slot.MESSAGE_REGISTER , Virtual::Slot::MESSAGE_SELF )
|
|
new_codes << RegisterMachine.instance.ldr( Slot.FRAME_REGISTER ,Slot.MESSAGE_REGISTER , Virtual::Slot::MESSAGE_FRAME )
|
|
#load the return address into pc, affecting return. (other cpus have commands for this, but not arm)
|
|
new_codes << RegisterMachine.instance.ldr( :pc ,Slot.MESSAGE_REGISTER , Virtual::Slot::MESSAGE_RETURN_ADDRESS )
|
|
block.replace(code , new_codes )
|
|
end
|
|
end
|
|
end
|
|
Virtual::BootSpace.space.add_pass_after ReturnImplementation , CallImplementation
|
|
end
|