1/*
2 * Copyright (c) 2015-2016, 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 *
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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
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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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 Miscellaneous optimisations.
31 */
32
33#ifndef NG_MISC_OPT_H
34#define NG_MISC_OPT_H
35
36#include <map>
37#include <vector>
38
39#include "ng_holder.h"
40#include "som/som.h"
41#include "util/depth.h"
42
43namespace ue2 {
44
45/** Small structure describing the bounds on a repeat. */
46struct BoundedRepeatSummary {
47 BoundedRepeatSummary(void) : repeatMin(0), repeatMax(depth::infinity()) {}
48 BoundedRepeatSummary(const depth &min_in, const depth &max_in)
49 : repeatMin(min_in), repeatMax(max_in) {
50 assert(repeatMin <= repeatMax);
51 assert(repeatMax.is_reachable());
52 }
53 bool unbounded(void) const { return repeatMax.is_infinite(); }
54
55 depth repeatMin; //!< minimum repeat bound.
56 depth repeatMax; //!< maximum repeat bound.
57};
58
59/* returns true if anything changed */
60bool improveGraph(NGHolder &g, som_type som);
61
62/** Sometimes the reach of a vertex is greater than it needs to be to reduce
63 * stop chars for the benefit of the rest of our code base (accel, etc). In
64 * these circumstances, we can treat the reach as the smaller one as
65 * the graphs are equivalent. */
66CharReach reduced_cr(NFAVertex v, const NGHolder &g,
67 const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic);
68
69std::vector<CharReach> reduced_cr(const NGHolder &g,
70 const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic);
71
72/** Remove cyclic stars connected to start */
73bool mergeCyclicDotStars(NGHolder &g);
74
75/**
76 * Given a cyclic state 'c' with a broad reach and a later state 'v' that is
77 * only reachable if c is still on, then any edges to a successor of a direct
78 * successor of c with reach a superset of v are redundant.
79 */
80bool prunePathsRedundantWithSuccessorOfCyclics(NGHolder &h, som_type som);
81
82} // namespace ue2
83
84#endif
85