Class: MilkTea::ControlFlow::ConstantPropagation

Inherits:
Object
  • Object
show all
Defined in:
lib/milk_tea/core/control_flow/constant_propagation.rb

Defined Under Namespace

Classes: ConstVal, Result

Constant Summary collapse

UNDEF = 
:undef
NAC = 
:nac

Class Method Summary collapse

Class Method Details

.constant_value_of(expr, in_state, binding_resolution: nil, strict_binding_ids: false) ⇒ Object 



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# File 'lib/milk_tea/core/control_flow/constant_propagation.rb', line 126

def self.constant_value_of(expr, in_state, binding_resolution: nil, strict_binding_ids: false)
  result = send(:eval_expr_const, expr, in_state, binding_resolution:, strict_binding_ids:)
  result.is_a?(ConstVal) ? result.value : nil
end

.solve(graph, binding_resolution: nil, strict_binding_ids: false) ⇒ Object 



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# File 'lib/milk_tea/core/control_flow/constant_propagation.rb', line 23

def self.solve(graph, binding_resolution: nil, strict_binding_ids: false)
  result = Dataflow.solve(
    graph,
    direction: :forward,
    initial: -> { {} },
    join: lambda do |states|
      return {} if states.empty?

      states.reduce do |acc, state|
        keys = acc.keys | state.keys
        keys.each_with_object({}) do |k, merged|
          a = acc[k]   || UNDEF
          b = state[k] || UNDEF
          merged[k] = join_lattice(a, b)
        end
      end
    end,
    transfer: lambda do |node, in_state|
      out = in_state.dup
      node.writes_info.each do |write|
        key = write[:binding_key]
        val = eval_const(node.statement, write, in_state, binding_resolution:, strict_binding_ids:)
        out[key] = val
      end
      out
    end,
    boundary_in: { graph.entry_id => {} }
  )

  Result.new(in_states: result.in_states, out_states: result.out_states)
end