coalesce.hpp revision 4514:8373c19be854 
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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 LRG_List;
33class Matcher;
34class PhaseIFG;
35class PhaseCFG;
36
37//------------------------------PhaseCoalesce----------------------------------
38class PhaseCoalesce : public Phase {
39protected:
40  PhaseChaitin &_phc;
41
42public:
43  // Coalesce copies
44  PhaseCoalesce(PhaseChaitin &phc)
45  : Phase(Coalesce)
46  , _phc(phc) {}
47
48  virtual void verify() = 0;
49
50  // Coalesce copies
51  void coalesce_driver();
52
53  // Coalesce copies in this block
54  virtual void coalesce(Block *b) = 0;
55
56  // Attempt to coalesce live ranges defined by these 2
57  void combine_these_two(Node *n1, Node *n2);
58
59  LRG &lrgs(uint lidx) { return _phc.lrgs(lidx); }
60#ifndef PRODUCT
61  // Dump internally name
62  void dump(Node *n) const;
63  // Dump whole shebang
64  void dump() const;
65#endif
66};
67
68//------------------------------PhaseAggressiveCoalesce------------------------
69// Aggressively, pessimistic coalesce copies.  Aggressive means ignore graph
70// colorability; perhaps coalescing to the point of forcing a spill.
71// Pessimistic means we cannot coalesce if 2 live ranges interfere.  This
72// implies we do not hit a fixed point right away.
73class PhaseAggressiveCoalesce : public PhaseCoalesce {
74  uint _unique;
75public:
76  // Coalesce copies
77  PhaseAggressiveCoalesce( PhaseChaitin &chaitin ) : PhaseCoalesce(chaitin) {}
78
79  virtual void verify() { };
80
81  // Aggressively coalesce copies in this block
82  virtual void coalesce( Block *b );
83
84  // Where I fail to coalesce, manifest virtual copies as the Real Thing
85  void insert_copies( Matcher &matcher );
86
87  // Copy insertion needs some smarts in case live ranges overlap
88  void insert_copy_with_overlap( Block *b, Node *copy, uint dst_name, uint src_name );
89};
90
91
92//------------------------------PhaseConservativeCoalesce----------------------
93// Conservatively, pessimistic coalesce copies.  Conservative means do not
94// coalesce if the resultant live range will be uncolorable.  Pessimistic
95// means we cannot coalesce if 2 live ranges interfere.  This implies we do
96// not hit a fixed point right away.
97class PhaseConservativeCoalesce : public PhaseCoalesce {
98  IndexSet _ulr;               // Union live range interferences
99public:
100  // Coalesce copies
101  PhaseConservativeCoalesce( PhaseChaitin &chaitin );
102
103  virtual void verify();
104
105  // Conservatively coalesce copies in this block
106  virtual void coalesce( Block *b );
107
108  // Coalesce this chain of copies away
109  bool copy_copy( Node *dst_copy, Node *src_copy, Block *b, uint bindex );
110
111  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 );
112
113  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);
114
115  void update_ifg(uint lr1, uint lr2, IndexSet *n_lr1, IndexSet *n_lr2);
116};
117
118#endif // SHARE_VM_OPTO_COALESCE_HPP
119