Mercurial > hg > graal-compiler
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/RightShiftNode.java @ 22790:615f3bbbb174
Update jvmci and truffle import: Rename jdk.internal.jvmci to jdk.vm.ci
author | Tom Rodriguez <tom.rodriguez@oracle.com> |
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date | Thu, 08 Oct 2015 17:41:33 -0700 |
parents | 26bbed810326 |
children |
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/* * Copyright (c) 2011, 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 jdk.vm.ci.code.CodeUtil; import com.oracle.graal.compiler.common.type.ArithmeticOpTable; import com.oracle.graal.compiler.common.type.ArithmeticOpTable.ShiftOp.Shr; import com.oracle.graal.compiler.common.type.IntegerStamp; import com.oracle.graal.graph.NodeClass; import com.oracle.graal.graph.spi.CanonicalizerTool; import com.oracle.graal.lir.gen.ArithmeticLIRGeneratorTool; import com.oracle.graal.nodeinfo.NodeInfo; import com.oracle.graal.nodes.ConstantNode; import com.oracle.graal.nodes.ValueNode; import com.oracle.graal.nodes.spi.NodeLIRBuilderTool; @NodeInfo(shortName = ">>") public final class RightShiftNode extends ShiftNode<Shr> { public static final NodeClass<RightShiftNode> TYPE = NodeClass.create(RightShiftNode.class); public RightShiftNode(ValueNode x, ValueNode y) { super(TYPE, ArithmeticOpTable::getShr, x, y); } @Override public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { ValueNode ret = super.canonical(tool, forX, forY); if (ret != this) { return ret; } if (forX.stamp() instanceof IntegerStamp && ((IntegerStamp) forX.stamp()).isPositive()) { return new UnsignedRightShiftNode(forX, forY); } if (forY.isConstant()) { int amount = forY.asJavaConstant().asInt(); int originalAmout = amount; int mask = getShiftAmountMask(); amount &= mask; if (amount == 0) { return forX; } if (forX instanceof ShiftNode) { ShiftNode<?> other = (ShiftNode<?>) forX; if (other.getY().isConstant()) { int otherAmount = other.getY().asJavaConstant().asInt() & mask; if (other instanceof RightShiftNode) { int total = amount + otherAmount; if (total != (total & mask)) { assert other.getX().stamp() instanceof IntegerStamp; IntegerStamp istamp = (IntegerStamp) other.getX().stamp(); if (istamp.isPositive()) { return ConstantNode.forIntegerKind(getStackKind(), 0); } if (istamp.isStrictlyNegative()) { return ConstantNode.forIntegerKind(getStackKind(), -1L); } /* * if we cannot replace both shifts with a constant, replace them by a * full shift for this kind */ assert total >= mask; return new RightShiftNode(other.getX(), ConstantNode.forInt(mask)); } return new RightShiftNode(other.getX(), ConstantNode.forInt(total)); } } } if (originalAmout != amount) { return new RightShiftNode(forX, ConstantNode.forInt(amount)); } } return this; } @Override public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) { nodeValueMap.setResult(this, gen.emitShr(nodeValueMap.operand(getX()), nodeValueMap.operand(getY()))); } @Override public boolean isNarrowable(int resultBits) { if (super.isNarrowable(resultBits)) { /* * For signed right shifts, the narrow can be done before the shift if the cut off bits * are all equal to the sign bit of the input. That's equivalent to the condition that * the input is in the signed range of the narrow type. */ IntegerStamp inputStamp = (IntegerStamp) getX().stamp(); return CodeUtil.minValue(resultBits) <= inputStamp.lowerBound() && inputStamp.upperBound() <= CodeUtil.maxValue(resultBits); } else { return false; } } }