rubyx/lib/slot_machine/instruction/same_check.rb
Torsten Rüger d751c53d1d Add a SameCheck and rename the label
SameCheck is very similar to NotSameCheck, but only used from the language
Label was named jump, fixed that
2020-02-19 02:16:44 +07:00

33 lines
1.0 KiB
Ruby

module SlotMachine
# SlotMachine internal check, as the name says to see if two values are the same
# In other words, we this checks identity, bit-values, pointers
#
# The values that are compared are defined as Slots, ie can be anything
# available to the machine through frame message or self
#
# Acording to SlotMachine::Check logic, we jump to the given label is the values are not the same
#
class SameCheck < Check
attr_reader :left , :right
def initialize(left, right , label)
super(label)
@left , @right = left , right
end
def to_s
"SameCheck: #{left}:#{right}"
end
# basically move both left and right values into register
# subtract them and see if IsZero comparison
def to_risc(compiler)
l_reg = left.to_register(compiler, self)
r_reg = right.to_register(compiler, self)
compiler.add_code Risc.op( self , :- , l_reg , r_reg)
compiler.add_code Risc::IsNotZero.new( self, false_label.risc_label(compiler))
end
end
end