1/*
2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package org.graalvm.compiler.nodes.graphbuilderconf;
24
25import jdk.vm.ci.meta.ResolvedJavaMethod;
26
27public interface LoopExplosionPlugin extends GraphBuilderPlugin {
28
29    enum LoopExplosionKind {
30        /**
31         * No loop explosion.
32         */
33        NONE,
34        /**
35         * Fully unroll all loops. The loops must have a known finite number of iterations. If a
36         * loop has multiple loop ends, they are merged so that the subsequent loop iteration is
37         * processed only once. For example, a loop with 4 iterations and 2 loop ends leads to
38         * 1+1+1+1 = 4 copies of the loop body.
39         */
40        FULL_UNROLL,
41        /**
42         * Fully explode all loops. The loops must have a known finite number of iterations. If a
43         * loop has multiple loop ends, they are not merged so that subsequent loop iterations are
44         * processed multiple times. For example, a loop with 4 iterations and 2 loop ends leads to
45         * 1+2+4+8 = 15 copies of the loop body.
46         */
47        FULL_EXPLODE,
48        /**
49         * Like {@link #FULL_EXPLODE}, but in addition explosion does not stop at loop exits. Code
50         * after the loop is duplicated for every loop exit of every loop iteration. For example, a
51         * loop with 4 iterations and 2 loop exits leads to 4 * 2 = 8 copies of the code after the
52         * loop.
53         */
54        FULL_EXPLODE_UNTIL_RETURN,
55        /**
56         * like {@link #FULL_EXPLODE}, but copies of the loop body that have the exact same state
57         * (all local variables have the same value) are merged. This reduces the number of copies
58         * necessary, but can introduce loops again. This kind is useful for bytecode interpreter
59         * loops.
60         */
61        MERGE_EXPLODE
62    }
63
64    LoopExplosionKind loopExplosionKind(ResolvedJavaMethod method);
65}
66