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  */
  23 package org.graalvm.compiler.nodes.graphbuilderconf;
  24 
  25 import jdk.vm.ci.meta.ResolvedJavaMethod;
  26 
  27 public 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 }