Mercurial > hg > truffle
view graal/com.oracle.graal.java.decompiler/src/com/oracle/graal/java/decompiler/DecompilerIfSimplify.java @ 18255:415c79fefdb3
TailDuplicationPhase.DummyAnchorNode: add allowedUsageTypes.
author | Josef Eisl <josef.eisl@jku.at> |
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date | Wed, 05 Nov 2014 11:48:13 +0100 |
parents | 29f47f2c6388 |
children |
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/* * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * 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. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.oracle.graal.java.decompiler; import java.io.*; import java.util.*; import com.oracle.graal.java.decompiler.block.*; import com.oracle.graal.java.decompiler.lines.*; import com.oracle.graal.nodes.cfg.*; public class DecompilerIfSimplify { private final Decompiler decompiler; private final PrintStream infoStream; public DecompilerIfSimplify(Decompiler decompiler, PrintStream infoStream) { this.decompiler = decompiler; this.infoStream = infoStream; } public List<DecompilerBlock> apply(List<DecompilerBlock> decompilerBlocks) { return detectIfs(decompilerBlocks); } private List<DecompilerBlock> detectIfs(List<DecompilerBlock> decompilerBlocks) { List<DecompilerBlock> blocks = new ArrayList<>(); while (!decompilerBlocks.isEmpty()) { if (decompilerBlocks.get(0) instanceof DecompilerBasicBlock) { DecompilerBasicBlock block = (DecompilerBasicBlock) decompilerBlocks.remove(0); if (block.getSuccessorCount() <= 1) { blocks.add(block); } else if (block.getSuccessorCount() == 2 && block.getCode().get(block.getCode().size() - 1) instanceof DecompilerIfLine) { Block firstThenBlock = block.getBlock().getSuccessors().get(0); Block firstElseBlock = block.getBlock().getSuccessors().get(1); List<DecompilerBlock> thenBlocks = getReachableDecompilerBlocks(firstThenBlock, decompilerBlocks); List<DecompilerBlock> elseBlocks = getReachableDecompilerBlocks(firstElseBlock, decompilerBlocks); removeIntersection(thenBlocks, elseBlocks); if (thenBlocks.size() == 0 && elseBlocks.size() == 0) { blocks.add(block); } else { for (DecompilerBlock b : thenBlocks) { decompilerBlocks.remove(b); } for (DecompilerBlock b : elseBlocks) { decompilerBlocks.remove(b); } // TODO(mg) // thenBlocks and elseBlocks can be both empty --> causes an AssertionError DecompilerIfBlock ifBlock = new DecompilerIfBlock(block.getBlock(), decompiler, thenBlocks, elseBlocks, infoStream); if (thenBlocks.contains(block) || elseBlocks.contains(block)) { throw new AssertionError(); } blocks.add(ifBlock); ifBlock.detectIfs(); } } else { blocks.add(block); } } else { if (decompilerBlocks.get(0) instanceof DecompilerLoopBlock) { DecompilerLoopBlock loop = (DecompilerLoopBlock) decompilerBlocks.get(0); loop.detectIfs(); } blocks.add(decompilerBlocks.remove(0)); } } return blocks; } private static List<DecompilerBlock> getReachableDecompilerBlocks(Block b, List<DecompilerBlock> decompilerBlocks) { List<DecompilerBlock> result = new ArrayList<>(); for (DecompilerBlock block : decompilerBlocks) { if (isReachable(b, block.getBlock(), new ArrayList<Block>())) { result.add(block); } } return result; } private static boolean isReachable(Block from, Block to, ArrayList<Block> visited) { if (from == to) { return true; } for (Block b : from.getSuccessors()) { if (b != from && visited.contains(b) == false && b.getId() > from.getId()) { visited.add(b); if (isReachable(b, to, visited)) { return true; } } } return false; } private static void removeIntersection(List<DecompilerBlock> list1, List<DecompilerBlock> list2) { List<DecompilerBlock> list1Copy = new ArrayList<>(list1); List<DecompilerBlock> list2Copy = new ArrayList<>(list2); list1.removeAll(list2Copy); list2.removeAll(list1Copy); } }