1/*
2 * Copyright (c) 2011, 2015, 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 */
23package org.graalvm.compiler.nodes.calc;
24
25import org.graalvm.compiler.core.common.type.ArithmeticOpTable;
26import org.graalvm.compiler.core.common.type.ArithmeticOpTable.ShiftOp.Shl;
27import org.graalvm.compiler.core.common.type.IntegerStamp;
28import org.graalvm.compiler.core.common.type.Stamp;
29import org.graalvm.compiler.graph.NodeClass;
30import org.graalvm.compiler.graph.spi.CanonicalizerTool;
31import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool;
32import org.graalvm.compiler.nodeinfo.NodeInfo;
33import org.graalvm.compiler.nodes.ConstantNode;
34import org.graalvm.compiler.nodes.ValueNode;
35import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
36
37import jdk.vm.ci.meta.JavaKind;
38
39@NodeInfo(shortName = "<<")
40public final class LeftShiftNode extends ShiftNode<Shl> {
41
42    public static final NodeClass<LeftShiftNode> TYPE = NodeClass.create(LeftShiftNode.class);
43
44    public LeftShiftNode(ValueNode x, ValueNode y) {
45        super(TYPE, ArithmeticOpTable::getShl, x, y);
46    }
47
48    public static ValueNode create(ValueNode x, ValueNode y) {
49        ArithmeticOpTable.ShiftOp<Shl> op = ArithmeticOpTable.forStamp(x.stamp()).getShl();
50        Stamp stamp = op.foldStamp(x.stamp(), (IntegerStamp) y.stamp());
51        ValueNode value = ShiftNode.canonical(op, stamp, x, y);
52        if (value != null) {
53            return value;
54        }
55
56        return canonical(null, op, stamp, x, y);
57    }
58
59    @Override
60    public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
61        ValueNode ret = super.canonical(tool, forX, forY);
62        if (ret != this) {
63            return ret;
64        }
65
66        return canonical(this, getArithmeticOp(), stamp(), forX, forY);
67    }
68
69    private static ValueNode canonical(LeftShiftNode leftShiftNode, ArithmeticOpTable.ShiftOp<Shl> op, Stamp stamp, ValueNode forX, ValueNode forY) {
70        LeftShiftNode self = leftShiftNode;
71        if (forY.isConstant()) {
72            int amount = forY.asJavaConstant().asInt();
73            int originalAmount = amount;
74            int mask = op.getShiftAmountMask(stamp);
75            amount &= mask;
76            if (amount == 0) {
77                return forX;
78            }
79            if (forX instanceof ShiftNode) {
80                ShiftNode<?> other = (ShiftNode<?>) forX;
81                if (other.getY().isConstant()) {
82                    int otherAmount = other.getY().asJavaConstant().asInt() & mask;
83                    if (other instanceof LeftShiftNode) {
84                        int total = amount + otherAmount;
85                        if (total != (total & mask)) {
86                            return ConstantNode.forIntegerKind(stamp.getStackKind(), 0);
87                        }
88                        return new LeftShiftNode(other.getX(), ConstantNode.forInt(total));
89                    } else if ((other instanceof RightShiftNode || other instanceof UnsignedRightShiftNode) && otherAmount == amount) {
90                        if (stamp.getStackKind() == JavaKind.Long) {
91                            return new AndNode(other.getX(), ConstantNode.forLong(-1L << amount));
92                        } else {
93                            assert stamp.getStackKind() == JavaKind.Int;
94                            return new AndNode(other.getX(), ConstantNode.forInt(-1 << amount));
95                        }
96                    }
97                }
98            }
99            if (originalAmount != amount) {
100                return new LeftShiftNode(forX, ConstantNode.forInt(amount));
101            }
102        }
103        if (self == null) {
104            self = new LeftShiftNode(forX, forY);
105        }
106        return self;
107    }
108
109    @Override
110    public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) {
111        nodeValueMap.setResult(this, gen.emitShl(nodeValueMap.operand(getX()), nodeValueMap.operand(getY())));
112    }
113}
114