1/*
2 * Copyright (c) 2009, 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.java;
24
25import org.graalvm.compiler.java.BciBlockMapping.BciBlock;
26
27public final class SmallLocalLiveness extends LocalLiveness {
28    /*
29     * local n is represented by the bit accessible as (1 << n)
30     */
31
32    private final long[] localsLiveIn;
33    private final long[] localsLiveOut;
34    private final long[] localsLiveGen;
35    private final long[] localsLiveKill;
36    private final long[] localsChangedInLoop;
37    private final int maxLocals;
38
39    public SmallLocalLiveness(BciBlock[] blocks, int maxLocals, int loopCount) {
40        super(blocks);
41        this.maxLocals = maxLocals;
42        int blockSize = blocks.length;
43        localsLiveIn = new long[blockSize];
44        localsLiveOut = new long[blockSize];
45        localsLiveGen = new long[blockSize];
46        localsLiveKill = new long[blockSize];
47        localsChangedInLoop = new long[loopCount];
48    }
49
50    private String debugString(long value) {
51        StringBuilder str = new StringBuilder("{");
52        long current = value;
53        for (int i = 0; i < maxLocals; i++) {
54            if ((current & 1L) == 1L) {
55                if (str.length() > 1) {
56                    str.append(", ");
57                }
58                str.append(i);
59            }
60            current >>= 1;
61        }
62        return str.append('}').toString();
63    }
64
65    @Override
66    protected String debugLiveIn(int blockID) {
67        return debugString(localsLiveIn[blockID]);
68    }
69
70    @Override
71    protected String debugLiveOut(int blockID) {
72        return debugString(localsLiveOut[blockID]);
73    }
74
75    @Override
76    protected String debugLiveGen(int blockID) {
77        return debugString(localsLiveGen[blockID]);
78    }
79
80    @Override
81    protected String debugLiveKill(int blockID) {
82        return debugString(localsLiveKill[blockID]);
83    }
84
85    @Override
86    protected int liveOutCardinality(int blockID) {
87        return Long.bitCount(localsLiveOut[blockID]);
88    }
89
90    @Override
91    protected void propagateLiveness(int blockID, int successorID) {
92        localsLiveOut[blockID] |= localsLiveIn[successorID];
93    }
94
95    @Override
96    protected void updateLiveness(int blockID) {
97        localsLiveIn[blockID] = (localsLiveOut[blockID] & ~localsLiveKill[blockID]) | localsLiveGen[blockID];
98    }
99
100    @Override
101    protected void loadOne(int blockID, int local) {
102        long bit = 1L << local;
103        if ((localsLiveKill[blockID] & bit) == 0L) {
104            localsLiveGen[blockID] |= bit;
105        }
106    }
107
108    @Override
109    protected void storeOne(int blockID, int local) {
110        long bit = 1L << local;
111        if ((localsLiveGen[blockID] & bit) == 0L) {
112            localsLiveKill[blockID] |= bit;
113        }
114
115        BciBlock block = blocks[blockID];
116        long tmp = block.loops;
117        int pos = 0;
118        while (tmp != 0) {
119            if ((tmp & 1L) == 1L) {
120                this.localsChangedInLoop[pos] |= bit;
121            }
122            tmp >>>= 1;
123            ++pos;
124        }
125    }
126
127    @Override
128    public boolean localIsLiveIn(BciBlock block, int local) {
129        int blockID = block.getId();
130        return blockID >= Integer.MAX_VALUE ? false : (localsLiveIn[blockID] & (1L << local)) != 0L;
131    }
132
133    @Override
134    public boolean localIsLiveOut(BciBlock block, int local) {
135        int blockID = block.getId();
136        return blockID >= Integer.MAX_VALUE ? false : (localsLiveOut[blockID] & (1L << local)) != 0L;
137    }
138
139    @Override
140    public boolean localIsChangedInLoop(int loopId, int local) {
141        return (localsChangedInLoop[loopId] & (1L << local)) != 0L;
142    }
143}
144