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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
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package org.graalvm.compiler.nodes;

import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;

Interface that overrides properties of a node, such as the node's stamp.
This interface allows richer canonicalizations when the current compilation context can provide a
narrower stamp than the one stored in the node itself. One such example is performing
canonicalization late in the compilation, when the nodes are already scheduled, and benefit from
additional stamp information from conditional checks in branches.
For example, in the following code, offset + i can be canonicalized once it is
scheduled into the branch:
public void update(int offset, int i) {
    if (i == 0) {
        array[offset + i];
    }
}

/**
 * Interface that overrides properties of a node, such as the node's stamp.
 *
 * This interface allows richer canonicalizations when the current compilation context can provide a
 * narrower stamp than the one stored in the node itself. One such example is performing
 * canonicalization late in the compilation, when the nodes are already scheduled, and benefit from
 * additional stamp information from conditional checks in branches.
 *
 * For example, in the following code, <code>offset + i</code> can be canonicalized once it is
 * scheduled into the branch:
 *
 * <pre>
 * public void update(int offset, int i) {
 *     if (i == 0) {
 *         array[offset + i];
 *     }
 * }
 * </pre>
 */
public interface NodeView {

    NodeView DEFAULT = new Default();

    class Default implements NodeView {
        @Override
        public Stamp stamp(ValueNode node) {
            return node.stamp;
        }
    }

    
Return a view-specific stamp of the node.
This stamp must be more specific than the default stamp.
/**
     * Return a view-specific stamp of the node.
     *
     * This stamp must be more specific than the default stamp.
     */
    Stamp stamp(ValueNode node);

    static NodeView from(CanonicalizerTool tool) {
        if (tool instanceof NodeView) {
            return (NodeView) tool;
        }
        return DEFAULT;
    }
}