J9CFGSimplifier.hpp

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 * Copyright (c) 2019, 2019 IBM Corp. and others
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#ifndef J9_CFGSIMPLIFIER_INCL
#define J9_CFGSIMPLIFIER_INCL

#include "optimizer/OMRCFGSimplifier.hpp"

namespace J9
{

// Performs local common subexpression elimination within
// a basic block.
//

class CFGSimplifier : public OMR::CFGSimplifier
   {
   public:

   CFGSimplifier(TR::OptimizationManager *manager) : OMR::CFGSimplifier(manager)
      {}

   protected:
   /**
    * \brief
    *    This virtual function calls individual routines to try to match different `if` control flow structures 
    *    for simplification.
    *
    * \parm needToDuplicateTree
    *    Boolean to indicate whether or not to duplicate node.
    *
    * \return Boolean that indicates whether tranformation is performed based on a matched pattern
    */
   virtual bool simplifyIfPatterns(bool needToDuplicateTree);

   /**
    * \brief
    *    This function tries to match an `ifacmpeq/ifacmpne` of NULL node with a throw of an NPE exception 
    *    for the unresolved case and replace with a NULLCHK node
    *
    * \parm needToDuplicateTree
    *    Boolean to indicate whether or not to duplicate node.
    *
    * \return Boolean that indicates true if tranformation is performed based on a matched pattern.
    */
   bool simplifyUnresolvedRequireNonNull(bool needToDuplicateTree);

   /**
    * \brief
    *    This function tries to match an `ifacmpeq/ifacmpne` of NULL node with a throw of an NPE exception 
    *    for the resolved case and replace with a NULLCHK node
    *
    * \parm needToDuplicateTree
    *    Boolean to indicate whether or not to duplicate node.
    *
    * \return Boolean that indicates true if tranformation is performed based on a matched pattern.
    */
   bool simplifyResolvedRequireNonNull(bool needToDuplicateTree);

   };

}

#endif