51 lines
1.1 KiB
Ruby
51 lines
1.1 KiB
Ruby
module Risc
|
|
|
|
# A branch must branch to a label.
|
|
# Different Branches (derived classes) use different registers, the base
|
|
# just stores the Label
|
|
class Branch < Instruction
|
|
def initialize( source , label )
|
|
super(source)
|
|
@label = label
|
|
end
|
|
attr_reader :label
|
|
|
|
def to_s
|
|
class_source "#{label ? label.name : '(no label)'}"
|
|
end
|
|
alias :inspect :to_s
|
|
|
|
end
|
|
|
|
# dynamic version of an Unconditional branch that jumps to the contents
|
|
# of a register instead of a hardcoded address
|
|
# As Branches jump to Labels, this is not derived from Branch
|
|
# PS: to conditionally jump to a dynamic adddress we do a normal branch
|
|
# over the dynamic one and then a dynamic one. Save us having all types of branches
|
|
# in two versions
|
|
class DynamicJump < Instruction
|
|
def initialize( source , register )
|
|
super(source)
|
|
@register = register
|
|
end
|
|
attr_reader :register
|
|
end
|
|
|
|
class Unconditional < Branch
|
|
|
|
end
|
|
|
|
class IsZero < Branch
|
|
end
|
|
|
|
class IsNotZero < Branch
|
|
end
|
|
|
|
class IsMinus < Branch
|
|
end
|
|
|
|
class IsPlus < Branch
|
|
end
|
|
|
|
end
|