AMD64RoundNode.java revision 12651:6ef01bd40ce2 
1/*
2 * Copyright (c) 2016, 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.replacements.amd64;
24
25import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_1;
26
27import org.graalvm.compiler.core.common.type.FloatStamp;
28import org.graalvm.compiler.core.common.type.Stamp;
29import org.graalvm.compiler.debug.GraalError;
30import org.graalvm.compiler.graph.NodeClass;
31import org.graalvm.compiler.graph.spi.CanonicalizerTool;
32import org.graalvm.compiler.lir.amd64.AMD64ArithmeticLIRGeneratorTool;
33import org.graalvm.compiler.lir.amd64.AMD64ArithmeticLIRGeneratorTool.RoundingMode;
34import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool;
35import org.graalvm.compiler.nodeinfo.NodeInfo;
36import org.graalvm.compiler.nodes.ConstantNode;
37import org.graalvm.compiler.nodes.ValueNode;
38import org.graalvm.compiler.nodes.calc.UnaryNode;
39import org.graalvm.compiler.nodes.spi.ArithmeticLIRLowerable;
40import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
41
42import jdk.vm.ci.meta.JavaConstant;
43import jdk.vm.ci.meta.JavaKind;
44
45/**
46 * Round floating-point value.
47 */
48@NodeInfo(cycles = CYCLES_1)
49public final class AMD64RoundNode extends UnaryNode implements ArithmeticLIRLowerable {
50    public static final NodeClass<AMD64RoundNode> TYPE = NodeClass.create(AMD64RoundNode.class);
51
52    private final RoundingMode mode;
53
54    public AMD64RoundNode(ValueNode value, RoundingMode mode) {
55        super(TYPE, roundStamp((FloatStamp) value.stamp(), mode), value);
56        this.mode = mode;
57    }
58
59    private static double round(RoundingMode mode, double input) {
60        switch (mode) {
61            case DOWN:
62                return Math.floor(input);
63            case NEAREST:
64                return Math.rint(input);
65            case UP:
66                return Math.ceil(input);
67            case TRUNCATE:
68                return (long) input;
69            default:
70                throw GraalError.unimplemented("unimplemented RoundingMode " + mode);
71        }
72    }
73
74    private static FloatStamp roundStamp(FloatStamp stamp, RoundingMode mode) {
75        double min = stamp.lowerBound();
76        min = Math.min(min, round(mode, min));
77
78        double max = stamp.upperBound();
79        max = Math.max(max, round(mode, max));
80
81        return new FloatStamp(stamp.getBits(), min, max, stamp.isNonNaN());
82    }
83
84    @Override
85    public Stamp foldStamp(Stamp newStamp) {
86        assert newStamp.isCompatible(getValue().stamp());
87        return roundStamp((FloatStamp) newStamp, mode);
88    }
89
90    public ValueNode tryFold(ValueNode input) {
91        if (input.isConstant()) {
92            JavaConstant c = input.asJavaConstant();
93            if (c.getJavaKind() == JavaKind.Double) {
94                return ConstantNode.forDouble(round(mode, c.asDouble()));
95            } else if (c.getJavaKind() == JavaKind.Float) {
96                return ConstantNode.forFloat((float) round(mode, c.asFloat()));
97            }
98        }
99        return null;
100    }
101
102    @Override
103    public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {
104        ValueNode folded = tryFold(forValue);
105        return folded != null ? folded : this;
106    }
107
108    @Override
109    public void generate(NodeLIRBuilderTool builder, ArithmeticLIRGeneratorTool gen) {
110        builder.setResult(this, ((AMD64ArithmeticLIRGeneratorTool) gen).emitRound(builder.operand(getValue()), mode));
111    }
112}
113