1/*
2 * Copyright (c) 1997, 2013, 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.
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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
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23 */
24
25#ifndef SHARE_VM_OPTO_COALESCE_HPP
26#define SHARE_VM_OPTO_COALESCE_HPP
27
28#include "opto/phase.hpp"
29
30class LoopTree;
31class LRG;
32class Matcher;
33class PhaseIFG;
34class PhaseCFG;
35
36//------------------------------PhaseCoalesce----------------------------------
37class PhaseCoalesce : public Phase {
38protected:
39  PhaseChaitin &_phc;
40
41public:
42  // Coalesce copies
43  PhaseCoalesce(PhaseChaitin &phc)
44  : Phase(Coalesce)
45  , _phc(phc) {}
46
47  virtual void verify() = 0;
48
49  // Coalesce copies
50  void coalesce_driver();
51
52  // Coalesce copies in this block
53  virtual void coalesce(Block *b) = 0;
54
55  // Attempt to coalesce live ranges defined by these 2
56  void combine_these_two(Node *n1, Node *n2);
57
58  LRG &lrgs(uint lidx) { return _phc.lrgs(lidx); }
59#ifndef PRODUCT
60  // Dump internally name
61  void dump(Node *n) const;
62  // Dump whole shebang
63  void dump() const;
64#endif
65};
66
67//------------------------------PhaseAggressiveCoalesce------------------------
68// Aggressively, pessimistic coalesce copies.  Aggressive means ignore graph
69// colorability; perhaps coalescing to the point of forcing a spill.
70// Pessimistic means we cannot coalesce if 2 live ranges interfere.  This
71// implies we do not hit a fixed point right away.
72class PhaseAggressiveCoalesce : public PhaseCoalesce {
73  uint _unique;
74public:
75  // Coalesce copies
76  PhaseAggressiveCoalesce( PhaseChaitin &chaitin ) : PhaseCoalesce(chaitin) {}
77
78  virtual void verify() { };
79
80  // Aggressively coalesce copies in this block
81  virtual void coalesce( Block *b );
82
83  // Where I fail to coalesce, manifest virtual copies as the Real Thing
84  void insert_copies( Matcher &matcher );
85
86  // Copy insertion needs some smarts in case live ranges overlap
87  void insert_copy_with_overlap( Block *b, Node *copy, uint dst_name, uint src_name );
88};
89
90
91//------------------------------PhaseConservativeCoalesce----------------------
92// Conservatively, pessimistic coalesce copies.  Conservative means do not
93// coalesce if the resultant live range will be uncolorable.  Pessimistic
94// means we cannot coalesce if 2 live ranges interfere.  This implies we do
95// not hit a fixed point right away.
96class PhaseConservativeCoalesce : public PhaseCoalesce {
97  IndexSet _ulr;               // Union live range interferences
98public:
99  // Coalesce copies
100  PhaseConservativeCoalesce( PhaseChaitin &chaitin );
101
102  virtual void verify();
103
104  // Conservatively coalesce copies in this block
105  virtual void coalesce( Block *b );
106
107  // Coalesce this chain of copies away
108  bool copy_copy( Node *dst_copy, Node *src_copy, Block *b, uint bindex );
109
110  void union_helper( Node *lr1_node, Node *lr2_node, uint lr1, uint lr2, Node *src_def, Node *dst_copy, Node *src_copy, Block *b, uint bindex );
111
112  uint compute_separating_interferences(Node *dst_copy, Node *src_copy, Block *b, uint bindex, RegMask &rm, uint rm_size, uint reg_degree, uint lr1, uint lr2);
113
114  void update_ifg(uint lr1, uint lr2, IndexSet *n_lr1, IndexSet *n_lr2);
115};
116
117#endif // SHARE_VM_OPTO_COALESCE_HPP
118