Mercurial > hg > truffle
view graal/com.oracle.graal.compiler.common/src/com/oracle/graal/compiler/common/cfg/AbstractControlFlowGraph.java @ 16505:45f92700119f
Move AbstractBlock.{dominates, isDominatedBy} to AbstractControlFlowGraph.
author | Josef Eisl <josef.eisl@jku.at> |
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date | Mon, 14 Jul 2014 19:32:01 +0200 |
parents | b07f96c783ad |
children | 79bbd0e9f1c9 |
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/* * Copyright (c) 2014, 2014, 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.compiler.common.cfg; import java.util.*; public interface AbstractControlFlowGraph<T extends AbstractBlock<T>> { static final int BLOCK_ID_INITIAL = -1; static final int BLOCK_ID_VISITED = -2; /** * Returns the list blocks contained in this control flow graph. * * It is {@linkplain CFGVerifier guaranteed} that the blocks are numbered according to a reverse * post order traversal of the control flow graph. * * @see CFGVerifier */ List<T> getBlocks(); Collection<Loop<T>> getLoops(); T getStartBlock(); /** * True if block {@code a} is dominated by block {@code b}. */ static boolean isDominatedBy(AbstractBlock<?> a, AbstractBlock<?> b) { assert a != null; if (a == b) { return true; } if (a.getDominator() == null) { return false; } return isDominatedBy(a.getDominator(), b); } /** * True if block {@code a} dominates block {@code b}. */ static boolean dominates(AbstractBlock<?> a, AbstractBlock<?> b) { assert a != null; return isDominatedBy(b, a); } /** * Calculates the common dominator of two blocks. * * Note that this algorithm makes use of special properties regarding the numbering of blocks. * * @see #getBlocks() * @see CFGVerifier */ public static AbstractBlock<?> commonDominator(AbstractBlock<?> a, AbstractBlock<?> b) { if (a == null) { return b; } if (b == null) { return a; } AbstractBlock<?> iterA = a; AbstractBlock<?> iterB = b; while (iterA != iterB) { if (iterA.getId() > iterB.getId()) { iterA = iterA.getDominator(); } else { assert iterB.getId() > iterA.getId(); iterB = iterB.getDominator(); } } return iterA; } /** * @see AbstractControlFlowGraph#commonDominator(AbstractBlock, AbstractBlock) */ @SuppressWarnings("unchecked") public static <T extends AbstractBlock<T>> T commonDominatorTyped(T a, T b) { return (T) commonDominator(a, b); } }