rubyx/lib/slot_machine/instruction/argument_transfer.rb
Torsten Rüger c43436f35a Change Mom to SlotMachine
rather large commit, but essentially a simple rename
Rationale in docs and blogs
2019-10-03 20:55:41 +03:00

52 lines
1.9 KiB
Ruby

module Mom
# Transering the arguments from the current frame into the next frame
#
# This could be _done_ at this level, and in fact used to be.
# The instruction was introduced to
# 1. make optimisations easier
# 2. localise the inevitable change
#
# 1. The optimal risc implementation for this loads old and new frames into registers
# and does a whole bunch of transfers
# But if we do individual SlotMoves here, each one has to load the frames,
# thus making advanced analysis/optimisation neccessary to achieve the same effect.
#
# 2. Closures will have to have access to variables after the frame goes out of scope
# and in fact be able to change the parents variables. The current design does not allow
# for this, and so will have to be change in the not so distant future.
#
class ArgumentTransfer < Instruction
attr_reader :receiver , :arguments
# receiver is a slot_definition
# arguments is an array of SlotLoads
def initialize( source , receiver,arguments )
super(source)
@receiver , @arguments = receiver , arguments
raise "Receiver not SlotDefinition #{@receiver}" unless @receiver.is_a?(SlotDefinition)
@arguments.each{|a| raise "args not SlotLoad #{a}" unless a.is_a?(SlotLoad)}
end
def to_s
"ArgumentTransfer " + ([@receiver] + @arguments).join(",")
end
# load receiver and then each arg into the new message
# delegates to SlotLoad for receiver and to the actual args.to_risc
def to_risc(compiler)
transfer = SlotLoad.new(self.source ,[:message , :next_message , :receiver] , @receiver, self).to_risc(compiler)
#TODO transfer the Number of arguments to :arguments_given (to be checked on entry)
compiler.reset_regs
@arguments.each do |arg|
arg.to_risc(compiler)
compiler.reset_regs
end
transfer
end
end
end