1 /*
   2  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 
  25 package org.graalvm.compiler.phases.common;
  26 
  27 import org.graalvm.compiler.nodes.FrameState;
  28 import org.graalvm.compiler.nodes.LoopExitNode;
  29 import org.graalvm.compiler.nodes.ProxyNode;
  30 import org.graalvm.compiler.nodes.StructuredGraph;
  31 import org.graalvm.compiler.nodes.util.GraphUtil;
  32 import org.graalvm.compiler.phases.Phase;
  33 
  34 public class RemoveValueProxyPhase extends Phase {
  35 
  36     @Override
  37     protected void run(StructuredGraph graph) {
  38         for (LoopExitNode exit : graph.getNodes(LoopExitNode.TYPE)) {
  39             for (ProxyNode vpn : exit.proxies().snapshot()) {
  40                 vpn.replaceAtUsagesAndDelete(vpn.value());
  41             }
  42             FrameState stateAfter = exit.stateAfter();
  43             if (stateAfter != null) {
  44                 exit.setStateAfter(null);
  45                 if (stateAfter.hasNoUsages()) {
  46                     GraphUtil.killWithUnusedFloatingInputs(stateAfter);
  47                 }
  48             }
  49         }
  50         graph.setHasValueProxies(false);
  51     }
  52 }