PostEscapeAnalysis.cpp

/*******************************************************************************
 * Copyright IBM Corp. and others 2019
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0
 * or the Apache License, Version 2.0 which accompanies this distribution
 * and is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception [1] and GNU General Public
 * License, version 2 with the OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 *******************************************************************************/

#include "il/Block.hpp"
#include "il/TreeTop.hpp"
#include "il/Node.hpp"
#include "il/Node_inlines.hpp"
#include "il/SymbolReference.hpp"
#include "optimizer/EscapeAnalysisTools.hpp"
#include "optimizer/PostEscapeAnalysis.hpp"
#include "optimizer/TransformUtil.hpp"
#include "optimizer/Optimizer.hpp"
#include "optimizer/OptimizationManager.hpp"

int32_t TR_PostEscapeAnalysis::perform()
   {
   if (!optimizer()->isEnabled(OMR::escapeAnalysis))
      {
      if (comp()->trace(OMR::escapeAnalysis))
         {
         traceMsg(comp(), "EscapeAnalysis is disabled - skipping Post-EscapeAnalysis\n");
         }
      return 0;
      }

   if (comp()->getOSRMode() != TR::voluntaryOSR)
      {
      if (comp()->trace(OMR::escapeAnalysis))
         {
         traceMsg(comp(), "Special handling of OSR points is not possible outside of voluntary OSR - nothing to do\n");
         }
      return 0;
      }
   if (optimizer()->getOptimization(OMR::escapeAnalysis)->numPassesCompleted() != 0)
      {
      if (comp()->trace(OMR::escapeAnalysis))
         {
         traceMsg(comp(), "EA has self enabled - skipping clean-up\n");
         }
      return 0;
      }

   for (TR::TreeTop *itr = comp()->getStartTree(); itr; itr = itr->getNextTreeTop())
      {
      // Remove any fake escape calls that were added to OSR
      // induction blocks by TR_PreEscapeAnalysis
      if (itr->getNode()->getNumChildren() == 1
          && itr->getNode()->getFirstChild()->getOpCodeValue() == TR::call
          && TR_EscapeAnalysisTools::isFakeEscape(itr->getNode()->getFirstChild()))
         {
         dumpOptDetails(comp(), " Removing fake call <eaEscapeHelper> n%dn\n", itr->getNode()->getFirstChild()->getGlobalIndex());
         itr = itr->getPrevTreeTop();
         if (optimizer()->getUseDefInfo() != NULL)
            {
            optimizer()->setUseDefInfo(NULL);
            }
         if (optimizer()->getValueNumberInfo())
            {
            optimizer()->setValueNumberInfo(NULL);
            }
         TR::TransformUtil::removeTree(comp(), itr->getNextTreeTop());
         }
      }

   if (comp()->trace(OMR::escapeAnalysis))
      {
      comp()->dumpMethodTrees("Trees after Post-Escape Analysis");
      }

   return 1;
   }

const char *
TR_PostEscapeAnalysis::optDetailString() const throw()
   {
   return "O^O POST ESCAPE ANALYSIS: ";
   }