Mercurial > hg > graal-compiler
view graal/GraalCompiler/src/com/sun/c1x/ir/StateSplit.java @ 2509:16b9a8b5ad39
Renamings Runtime=>GraalRuntime and Compiler=>GraalCompiler
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Wed, 27 Apr 2011 11:50:44 +0200 |
parents | graal/Compiler/src/com/sun/c1x/ir/StateSplit.java@9ec15d6914ca |
children | c58a301eb2d7 |
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/* * Copyright (c) 2009, 2011, 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.sun.c1x.ir; import com.sun.c1x.value.*; import com.sun.cri.ci.*; /** * The {@code StateSplit} class is the abstract base class of all instructions * that store an immutable copy of the frame state. * * @author Ben L. Titzer */ public abstract class StateSplit extends Instruction { /** * Sentinel denoting an explicitly cleared state. */ private static final FrameState CLEARED_STATE = new MutableFrameState(null, -5, 0, 0); private FrameState stateBefore; /** * Creates a new state split with the specified value type. * @param kind the type of the value that this instruction produces */ public StateSplit(CiKind kind, FrameState stateBefore) { super(kind); this.stateBefore = stateBefore; } /** * Determines if the state for this instruction has explicitly * been cleared (as opposed to never initialized). Once explicitly * cleared, an instruction must not have it state (re)set. */ public boolean isStateCleared() { return stateBefore == CLEARED_STATE; } /** * Clears the state for this instruction. Once explicitly * cleared, an instruction must not have it state (re)set. */ protected void clearState() { stateBefore = CLEARED_STATE; } /** * Records the state of this instruction before it is executed. * * @param stateBefore the state */ public final void setStateBefore(FrameState stateBefore) { assert this.stateBefore == null; this.stateBefore = stateBefore; } /** * Gets the state for this instruction. * @return the state */ @Override public final FrameState stateBefore() { return stateBefore == CLEARED_STATE ? null : stateBefore; } }