1/*
2 * Copyright (c) 2015, Intel Corporation
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * * Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of Intel Corporation nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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27 */
28
29/** \file
30 * \brief Edge redundancy graph reductions.
31 */
32#ifndef NG_EDGE_REDUNDANCY_H
33#define NG_EDGE_REDUNDANCY_H
34
35#include "som/som.h"
36
37namespace ue2 {
38
39class NGHolder;
40struct CompileContext;
41
42/** \brief Entry point: Runs all the edge redundancy passes. */
43bool removeEdgeRedundancy(NGHolder &g, som_type som, const CompileContext &cc);
44
45/** \brief Removes optional stuff from the front of floating patterns, since
46 * it's redundant with startDs.
47 *
48 * For each successor of startDs, remove any in-edges that aren't from either
49 * start or startDs. This allows us to prune redundant vertices at the start of
50 * a pattern:
51 *
52 * /(hat)?stand --> /stand/
53 *
54 */
55bool removeSiblingsOfStartDotStar(NGHolder &g);
56
57/** \brief Removes all edges into virtual starts other than those from
58 * start/startDs, providing there is an edge from startDs.
59 *
60 * This operation is an optimisation for SOM mode. (see UE-1544) */
61bool optimiseVirtualStarts(NGHolder &g);
62
63} // namespace ue2
64
65#endif
66