view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/FloatLessThanNode.java @ 5425:0364a2a874b8

changes towards a canonical representation of comparisons: * new createNullCheckGuard helper method on CiLoweringTool * replaced NullCheckNode with IsNullNode * GuardNode and FixedGuardNode can be negated * keep a list of conditions that are true/false in CheckCastEliminationPhase * FixedGuardNode has only one condition * GraphBuilderPhase creates canonical CompareNodes * BooleanNodes can negate their usages * added junit test for canonicalized compares * removed junit test for negated instanceof * added more thorough graph comparison for junit tests * CheckCastEliminationPhase keeps track of conditions that are known to be true/false
author Lukas Stadler <lukas.stadler@jku.at>
date Tue, 22 May 2012 16:19:02 +0200
parents
children e23980f4a890
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/*
 * Copyright (c) 2011, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.graal.nodes.calc;

import com.oracle.graal.graph.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.spi.*;

@NodeInfo(shortName = "<")
public final class FloatLessThanNode extends CompareNode {

    private final boolean unorderedIsTrue;

    /**
     * Constructs a new floating point comparison node.
     *
     * @param x the instruction producing the first input to the instruction
     * @param y the instruction that produces the second input to this instruction
     * @param unorderedIsTrue whether a comparison that is undecided (involving NaNs, etc.) leads to a "true" result
     */
    public FloatLessThanNode(ValueNode x, ValueNode y, boolean unorderedIsTrue) {
        super(x, y);
        assert x.kind().isFloatOrDouble();
        assert y.kind().isFloatOrDouble();
        this.unorderedIsTrue = unorderedIsTrue;
    }

    @Override
    public Condition condition() {
        return Condition.LT;
    }

    @Override
    public boolean unorderedIsTrue() {
        return unorderedIsTrue;
    }

    @Override
    public ValueNode canonical(CanonicalizerTool tool) {
        if (x() == y() && !unorderedIsTrue()) {
            return ConstantNode.forBoolean(false, graph());
        }
        return super.canonical(tool);
    }
}