rubyx/lib/risc/instructions/branch.rb
Torsten Rüger b36ba42990 Test complied parfait tests
this makes it obvious that we need a working raise
and a correct method_missing, so we can diagnose the 
resulting errors
2019-09-15 12:18:31 +03:00

73 lines
1.8 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)
raise "not label #{label}:#{label.class}" unless label.is_a?(Label) or label.is_a?(Parfait::BinaryCode)
@label = label
end
attr_reader :label
def to_s
case label
when Label
str = label.name
when Parfait::BinaryCode
str = "Code"
str += ":#{Position.get(label)}" if Position.set?(label)
else
str = "(no label)"
end
class_source( str )
end
alias :inspect :to_s
# if branch_to is implemented it must return the label it branches to
def branch_to
label
end
end
# dynamic version of an 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
def to_s
class_source( register.to_s)
end
end
# A Dynamic yield is very much like a DynamicJump, especially in it's idea
#
# The implentation differes slightly, as we use a chache entry in the DynamicJump
# but a block in the DynamicYield.
# Using means that we assume the register to be ready loaded with a Block
class DynamicYield < DynamicJump
end
class IsZero < Branch
end
class IsNotZero < Branch
end
class IsMinus < Branch
end
class IsPlus < Branch
end
end