001/* 002 * Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved. 003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 004 * 005 * This code is free software; you can redistribute it and/or modify it 006 * under the terms of the GNU General Public License version 2 only, as 007 * published by the Free Software Foundation. 008 * 009 * This code is distributed in the hope that it will be useful, but WITHOUT 010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 011 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 012 * version 2 for more details (a copy is included in the LICENSE file that 013 * accompanied this code). 014 * 015 * You should have received a copy of the GNU General Public License version 016 * 2 along with this work; if not, write to the Free Software Foundation, 017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 018 * 019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 020 * or visit www.oracle.com if you need additional information or have any 021 * questions. 022 */ 023package com.oracle.graal.nodes.calc; 024 025import jdk.internal.jvmci.code.*; 026 027import com.oracle.graal.compiler.common.type.*; 028import com.oracle.graal.graph.*; 029import com.oracle.graal.graph.spi.*; 030import com.oracle.graal.nodeinfo.*; 031import com.oracle.graal.nodes.*; 032import com.oracle.graal.nodes.spi.*; 033 034@NodeInfo(shortName = "/") 035public class IntegerDivNode extends FixedBinaryNode implements Lowerable, LIRLowerable { 036 public static final NodeClass<IntegerDivNode> TYPE = NodeClass.create(IntegerDivNode.class); 037 038 public IntegerDivNode(ValueNode x, ValueNode y) { 039 this(TYPE, x, y); 040 } 041 042 protected IntegerDivNode(NodeClass<? extends IntegerDivNode> c, ValueNode x, ValueNode y) { 043 super(c, IntegerStamp.OPS.getDiv().foldStamp(x.stamp(), y.stamp()), x, y); 044 } 045 046 @Override 047 public boolean inferStamp() { 048 return updateStamp(IntegerStamp.OPS.getDiv().foldStamp(getX().stamp(), getY().stamp())); 049 } 050 051 @Override 052 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { 053 if (forX.isConstant() && forY.isConstant()) { 054 @SuppressWarnings("hiding") 055 long y = forY.asJavaConstant().asLong(); 056 if (y == 0) { 057 return this; // this will trap, can not canonicalize 058 } 059 return ConstantNode.forIntegerStamp(stamp(), forX.asJavaConstant().asLong() / y); 060 } else if (forY.isConstant()) { 061 long c = forY.asJavaConstant().asLong(); 062 if (c == 1) { 063 return forX; 064 } 065 if (c == -1) { 066 return new NegateNode(forX); 067 } 068 long abs = Math.abs(c); 069 if (CodeUtil.isPowerOf2(abs) && forX.stamp() instanceof IntegerStamp) { 070 ValueNode dividend = forX; 071 IntegerStamp stampX = (IntegerStamp) forX.stamp(); 072 int log2 = CodeUtil.log2(abs); 073 // no rounding if dividend is positive or if its low bits are always 0 074 if (stampX.canBeNegative() || (stampX.upMask() & (abs - 1)) != 0) { 075 int bits = PrimitiveStamp.getBits(stamp()); 076 RightShiftNode sign = new RightShiftNode(forX, ConstantNode.forInt(bits - 1)); 077 UnsignedRightShiftNode round = new UnsignedRightShiftNode(sign, ConstantNode.forInt(bits - log2)); 078 dividend = BinaryArithmeticNode.add(dividend, round); 079 } 080 RightShiftNode shift = new RightShiftNode(dividend, ConstantNode.forInt(log2)); 081 if (c < 0) { 082 return new NegateNode(shift); 083 } 084 return shift; 085 } 086 } 087 088 // Convert the expression ((a - a % b) / b) into (a / b). 089 if (forX instanceof SubNode) { 090 SubNode integerSubNode = (SubNode) forX; 091 if (integerSubNode.getY() instanceof IntegerRemNode) { 092 IntegerRemNode integerRemNode = (IntegerRemNode) integerSubNode.getY(); 093 if (integerSubNode.stamp().isCompatible(this.stamp()) && integerRemNode.stamp().isCompatible(this.stamp()) && integerSubNode.getX() == integerRemNode.getX() && 094 forY == integerRemNode.getY()) { 095 return new IntegerDivNode(integerSubNode.getX(), forY); 096 } 097 } 098 } 099 100 if (next() instanceof IntegerDivNode) { 101 NodeClass<?> nodeClass = getNodeClass(); 102 if (next().getClass() == this.getClass() && nodeClass.getInputEdges().areEqualIn(this, next()) && valueEquals(next())) { 103 return next(); 104 } 105 } 106 107 return this; 108 } 109 110 @Override 111 public void lower(LoweringTool tool) { 112 tool.getLowerer().lower(this, tool); 113 } 114 115 @Override 116 public void generate(NodeLIRBuilderTool gen) { 117 gen.setResult(this, gen.getLIRGeneratorTool().emitDiv(gen.operand(getX()), gen.operand(getY()), gen.state(this))); 118 } 119 120 @Override 121 public boolean canDeoptimize() { 122 return !(getY().stamp() instanceof IntegerStamp) || ((IntegerStamp) getY().stamp()).contains(0); 123 } 124}