/*
* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package com.oracle.max.graal.compiler.phases;
import com.oracle.max.criutils.*;
import com.oracle.max.graal.compiler.*;
import com.oracle.max.graal.graph.*;
import com.oracle.max.graal.nodes.*;
import com.oracle.max.graal.nodes.extended.*;
public class ReadEliminationPhase extends Phase {
@Override
protected void run(StructuredGraph graph) {
for (ReadNode n : graph.getNodes(ReadNode.class)) {
if (n.dependencies().size() > 0) {
Node memoryInput = n.dependencies().get(0);
if (memoryInput instanceof WriteNode) {
WriteNode other = (WriteNode) memoryInput;
if (other.object() == n.object() && other.location() == n.location()) {
if (GraalOptions.TraceReadElimination) {
TTY.println("Eliminated memory read " + n + "and replaced with node " + other.value());
}
n.replaceAndDelete(other.value());
}
}
}
}
}
}