rubyx/lib/register/return_implementation.rb
2014-09-25 20:29:05 +03:00

24 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 = []
machine = RegisterMachine.instance
slot = Virtual::Slot
# move the current message to new_message
new_codes << machine.mov( slot::MESSAGE_REGISTER , slot::NEW_MESSAGE_REGISTER )
# and restore the message from saved value in new_message
new_codes << machine.ldr( slot::MESSAGE_REGISTER ,slot::NEW_MESSAGE_REGISTER , slot::MESSAGE_CALLER )
# "roll out" self and frame into their registers
new_codes << machine.ldr( slot::SELF_REGISTER ,slot::MESSAGE_REGISTER , slot::MESSAGE_SELF )
new_codes << machine.ldr( slot::FRAME_REGISTER ,slot::MESSAGE_REGISTER , slot::MESSAGE_FRAME )
#load the return address into pc, affecting return. (other cpus have commands for this, but not arm)
new_codes << machine.ldr( :pc ,slot::MESSAGE_REGISTER , slot::MESSAGE_RETURN_ADDRESS )
block.replace(code , new_codes )
end
end
end
Virtual::BootSpace.space.add_pass_after ReturnImplementation , CallImplementation
end