Mercurial > hg > truffle
view graal/GraalCompiler/src/com/sun/c1x/ir/CompareAndSwap.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/CompareAndSwap.java@9ec15d6914ca |
children |
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/* * Copyright (c) 2010, 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.debug.*; import com.sun.c1x.value.*; import com.sun.cri.bytecode.*; /** * Atomic update of a value in memory. Implements the {@link Bytecodes#PCMPSWP} family of instructions. * * Compares a suspected value with the actual value in a memory location. * Iff they are same, a new value is placed into the location and the expected value is returned. * Otherwise, the actual value is returned. * * @author Doug Simon */ public final class CompareAndSwap extends PointerOp { /** * The value to store. */ Value expectedValue; Value newValue; /** * Creates an instruction for a pointer store. If {@code displacement != null}, the effective of the address of the store is * computed as the pointer plus a byte displacement plus a scaled index. Otherwise, the effective address is computed as the * pointer plus a byte offset. * @param pointer the value producing the pointer * @param offset the value producing the byte offset * @param expectedValue the value that must currently being in memory location for the swap to occur * @param newValue the new value to store if the precondition is satisfied * @param stateBefore the state before * @param isVolatile {@code true} if the access is volatile */ public CompareAndSwap(int opcode, Value pointer, Value offset, Value expectedValue, Value newValue, FrameState stateBefore, boolean isVolatile) { super(expectedValue.kind, expectedValue.kind, opcode, pointer, null, offset, stateBefore, isVolatile); assert offset != null; this.expectedValue = expectedValue; this.newValue = newValue; setFlag(Flag.LiveStore); } @Override public void accept(ValueVisitor v) { v.visitCompareAndSwap(this); } public Value expectedValue() { return expectedValue; } public Value newValue() { return newValue; } @Override public void inputValuesDo(ValueClosure closure) { super.inputValuesDo(closure); expectedValue = closure.apply(expectedValue); newValue = closure.apply(newValue); } @Override public void print(LogStream out) { out.print(Bytecodes.nameOf(opcode)).print("(").print(pointer()); out.print(" + ").print(offset()); out.print(", ").print(expectedValue()).print(", ").print(newValue()).print(')'); } }