Class: Kumi::Core::Analyzer::Passes::LIR::ConstantPropagationPass

Inherits:
PassBase
  • Object
show all
Defined in:
lib/kumi/core/analyzer/passes/lir/constant_propagation_pass.rb

Overview

ConstantPropagationPass

This is an intra-block constant propagation pass. It substitutes the uses of registers that hold a known constant value with the literal constant itself.

This pass must run before DeadCodeEliminationPass to be effective. It doesn’t remove the original constant assignments; rather, it makes them “dead” by removing their uses, allowing a subsequent DCE pass to clean them up.

In : state Out: state.with(:lir_02_const_prop, …)

Constant Summary collapse

LIR = 
Kumi::Core::LIR

Instance Method Summary collapse

Methods inherited from PassBase

#debug, #debug_enabled?, #initialize

Methods included from ErrorReporting

#inferred_location, #raise_localized_error, #raise_syntax_error, #raise_type_error, #report_enhanced_error, #report_error, #report_semantic_error, #report_syntax_error, #report_type_error

Constructor Details

This class inherits a constructor from Kumi::Core::Analyzer::Passes::PassBase

Instance Method Details

#run(_errors) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/lir/constant_propagation_pass.rb', line 24

def run(_errors)
  ops_by_decl = get_state(:lir_module)
  out = {}

  ops_by_decl.each do |name, payload|
    operations = Array(payload[:operations])
    out[name] = { operations: optimize_decl(operations) }
  end

  out.freeze
  state.with(:lir_module, out).with(:lir_06_const_prop, out)
end