Mercurial > hg > truffle
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/ShiftNode.java @ 21678:7355942cb270
Improve lowering of the type check node.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Wed, 03 Jun 2015 01:10:18 +0200 |
parents | 48c1ebd24120 |
children |
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/* * Copyright (c) 2009, 2015, 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.nodes.calc; import java.io.*; import java.util.function.*; import com.oracle.graal.compiler.common.type.*; import com.oracle.graal.compiler.common.type.ArithmeticOpTable.ShiftOp; import com.oracle.graal.graph.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.nodeinfo.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.spi.*; import com.oracle.jvmci.code.*; import com.oracle.jvmci.meta.*; /** * The {@code ShiftOp} class represents shift operations. */ @NodeInfo public abstract class ShiftNode<OP> extends BinaryNode implements ArithmeticLIRLowerable, NarrowableArithmeticNode { @SuppressWarnings("rawtypes") public static final NodeClass<ShiftNode> TYPE = NodeClass.create(ShiftNode.class); protected interface SerializableShiftFunction<T> extends Function<ArithmeticOpTable, ShiftOp<T>>, Serializable { } protected final SerializableShiftFunction<OP> getOp; /** * Creates a new shift operation. * * @param x the first input value * @param s the second input value */ protected ShiftNode(NodeClass<? extends ShiftNode<OP>> c, SerializableShiftFunction<OP> getOp, ValueNode x, ValueNode s) { super(c, getOp.apply(ArithmeticOpTable.forStamp(x.stamp())).foldStamp(x.stamp(), (IntegerStamp) s.stamp()), x, s); assert ((IntegerStamp) s.stamp()).getBits() == 32; this.getOp = getOp; } protected final ShiftOp<OP> getOp(ValueNode forValue) { return getOp.apply(ArithmeticOpTable.forStamp(forValue.stamp())); } @Override public boolean inferStamp() { return updateStamp(getOp(getX()).foldStamp(getX().stamp(), (IntegerStamp) getY().stamp())); } @Override public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { if (forX.isConstant() && forY.isConstant()) { JavaConstant amount = forY.asJavaConstant(); assert amount.getKind() == Kind.Int; return ConstantNode.forPrimitive(stamp(), getOp(forX).foldConstant(forX.asConstant(), amount.asInt())); } return this; } public int getShiftAmountMask() { return getOp(getX()).getShiftAmountMask(stamp()); } public boolean isNarrowable(int resultBits) { assert CodeUtil.isPowerOf2(resultBits); int narrowMask = resultBits - 1; int wideMask = getShiftAmountMask(); assert (wideMask & narrowMask) == narrowMask : String.format("wideMask %x should be wider than narrowMask %x", wideMask, narrowMask); /* * Shifts are special because narrowing them also changes the implicit mask of the shift * amount. We can narrow only if (y & wideMask) == (y & narrowMask) for all possible values * of y. */ IntegerStamp yStamp = (IntegerStamp) getY().stamp(); return (yStamp.upMask() & (wideMask & ~narrowMask)) == 0; } }