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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.graphbuilderconf;

import jdk.vm.ci.meta.ResolvedJavaMethod;

public interface LoopExplosionPlugin extends GraphBuilderPlugin {

    enum LoopExplosionKind {
        
No loop explosion.
/**
         * No loop explosion.
         */
        NONE,
        
Fully unroll all loops. The loops must have a known finite number of iterations. If a
loop has multiple loop ends, they are merged so that the subsequent loop iteration is
processed only once. For example, a loop with 4 iterations and 2 loop ends leads to
1+1+1+1 = 4 copies of the loop body.
/**
         * Fully unroll all loops. The loops must have a known finite number of iterations. If a
         * loop has multiple loop ends, they are merged so that the subsequent loop iteration is
         * processed only once. For example, a loop with 4 iterations and 2 loop ends leads to
         * 1+1+1+1 = 4 copies of the loop body.
         */
        FULL_UNROLL,
        
Fully explode all loops. The loops must have a known finite number of iterations. If a
loop has multiple loop ends, they are not merged so that subsequent loop iterations are
processed multiple times. For example, a loop with 4 iterations and 2 loop ends leads to
1+2+4+8 = 15 copies of the loop body.
/**
         * Fully explode all loops. The loops must have a known finite number of iterations. If a
         * loop has multiple loop ends, they are not merged so that subsequent loop iterations are
         * processed multiple times. For example, a loop with 4 iterations and 2 loop ends leads to
         * 1+2+4+8 = 15 copies of the loop body.
         */
        FULL_EXPLODE,
        
Like FULL_EXPLODE, but in addition explosion does not stop at loop exits. Code after the loop is duplicated for every loop exit of every loop iteration. For example, a loop with 4 iterations and 2 loop exits leads to 4 * 2 = 8 copies of the code after the loop. /**
         * Like {@link #FULL_EXPLODE}, but in addition explosion does not stop at loop exits. Code
         * after the loop is duplicated for every loop exit of every loop iteration. For example, a
         * loop with 4 iterations and 2 loop exits leads to 4 * 2 = 8 copies of the code after the
         * loop.
         */
        FULL_EXPLODE_UNTIL_RETURN,
        
like FULL_EXPLODE, but copies of the loop body that have the exact same state (all local variables have the same value) are merged. This reduces the number of copies necessary, but can introduce loops again. This kind is useful for bytecode interpreter loops. /**
         * like {@link #FULL_EXPLODE}, but copies of the loop body that have the exact same state
         * (all local variables have the same value) are merged. This reduces the number of copies
         * necessary, but can introduce loops again. This kind is useful for bytecode interpreter
         * loops.
         */
        MERGE_EXPLODE
    }

    LoopExplosionKind loopExplosionKind(ResolvedJavaMethod method);
}