rubyx/lib/mom/instruction/not_same_check.rb
2018-04-17 20:26:15 +03:00

34 lines
1.0 KiB
Ruby

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