hotspot/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/spi/LoweringProvider.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
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 * 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.spi;

import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.memory.address.AddressNode;

import jdk.vm.ci.meta.JavaKind;

/**
 * Provides a capability for replacing a higher node with one or more lower level nodes.
 */
public interface LoweringProvider {

    void lower(Node n, LoweringTool tool);

    /**
     * Reconstructs the array index from an address node that was created as a lowering of an
     * indexed access to an array.
     *
     * @param elementKind the {@link JavaKind} of the array elements
     * @param address an {@link AddressNode} pointing to an element in an array
     * @return a node that gives the index of the element
     */
    ValueNode reconstructArrayIndex(JavaKind elementKind, AddressNode address);

    /**
     * Indicates whether the target platform supports comparison of integers of a particular bit
     * width. This check is used by optimizations that might introduce subword compares.
     */
    default boolean supportSubwordCompare(int bits) {
        // most platforms only support 32 and 64 bit compares
        return bits >= 32;
    }
}