1 /* 2 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 25 package org.graalvm.compiler.loop; 26 27 import org.graalvm.compiler.core.common.type.IntegerStamp; 28 import org.graalvm.compiler.nodes.FixedNode; 29 import org.graalvm.compiler.nodes.NodeView; 30 import org.graalvm.compiler.nodes.StructuredGraph; 31 import org.graalvm.compiler.nodes.ValueNode; 32 import org.graalvm.compiler.nodes.calc.BinaryArithmeticNode; 33 import org.graalvm.compiler.nodes.calc.FixedBinaryNode; 34 import org.graalvm.compiler.nodes.calc.SignedDivNode; 35 import org.graalvm.compiler.nodes.calc.UnsignedDivNode; 36 import org.graalvm.compiler.nodes.extended.GuardingNode; 37 38 import java.util.function.BiFunction; 39 40 /** 41 * Utility methods to perform integer math with some obvious constant folding first. 42 */ 43 public class MathUtil { 44 private static boolean isConstantOne(ValueNode v1) { 45 return v1.isConstant() && v1.stamp(NodeView.DEFAULT) instanceof IntegerStamp && v1.asJavaConstant().asLong() == 1; 46 } 47 48 private static boolean isConstantZero(ValueNode v1) { 49 return v1.isConstant() && v1.stamp(NodeView.DEFAULT) instanceof IntegerStamp && v1.asJavaConstant().asLong() == 0; 50 } 51 52 public static ValueNode add(StructuredGraph graph, ValueNode v1, ValueNode v2) { 53 if (isConstantZero(v1)) { 54 return v2; 55 } 56 if (isConstantZero(v2)) { 57 return v1; 58 } 59 return BinaryArithmeticNode.add(graph, v1, v2, NodeView.DEFAULT); 60 } 61 62 public static ValueNode mul(StructuredGraph graph, ValueNode v1, ValueNode v2) { 63 if (isConstantOne(v1)) { 64 return v2; 65 } 66 if (isConstantOne(v2)) { 67 return v1; 68 } 69 return BinaryArithmeticNode.mul(graph, v1, v2, NodeView.DEFAULT); 70 } 71 72 public static ValueNode sub(StructuredGraph graph, ValueNode v1, ValueNode v2) { 73 if (isConstantZero(v2)) { 74 return v1; 75 } 76 return BinaryArithmeticNode.sub(graph, v1, v2, NodeView.DEFAULT); 77 } 78 79 public static ValueNode divBefore(StructuredGraph graph, FixedNode before, ValueNode dividend, ValueNode divisor, GuardingNode zeroCheck) { 80 return fixedDivBefore(graph, before, dividend, divisor, (dend, sor) -> SignedDivNode.create(dend, sor, zeroCheck, NodeView.DEFAULT)); 81 } 82 83 public static ValueNode unsignedDivBefore(StructuredGraph graph, FixedNode before, ValueNode dividend, ValueNode divisor, GuardingNode zeroCheck) { 84 return fixedDivBefore(graph, before, dividend, divisor, (dend, sor) -> UnsignedDivNode.create(dend, sor, zeroCheck, NodeView.DEFAULT)); 85 } 86 87 private static ValueNode fixedDivBefore(StructuredGraph graph, FixedNode before, ValueNode dividend, ValueNode divisor, BiFunction<ValueNode, ValueNode, ValueNode> createDiv) { 88 if (isConstantOne(divisor)) { 89 return dividend; 90 } 91 ValueNode div = graph.addOrUniqueWithInputs(createDiv.apply(dividend, divisor)); 92 if (div instanceof FixedBinaryNode) { 93 FixedBinaryNode fixedDiv = (FixedBinaryNode) div; 94 if (before.predecessor() instanceof FixedBinaryNode) { 95 FixedBinaryNode binaryPredecessor = (FixedBinaryNode) before.predecessor(); 96 if (fixedDiv.dataFlowEquals(binaryPredecessor)) { 97 fixedDiv.safeDelete(); 98 return binaryPredecessor; 99 } 100 } 101 graph.addBeforeFixed(before, fixedDiv); 102 } 103 return div; 104 } 105 }