1 /* Header file for gimple ranger SSA cache.
2    Copyright (C) 2017-2021 Free Software Foundation, Inc.
3    Contributed by Andrew MacLeod <amacleod@redhat.com>.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11 
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15  for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 #ifndef GCC_SSA_RANGE_CACHE_H
22 #define GCC_SSA_RANGE_CACHE_H
23 
24 #include "gimple-range-gori.h"
25 
26 // Class used to track non-null references of an SSA name.  A vector
27 // of bitmaps indexed by SSA name is maintained.  When indexed by
28 // basic block, an on-bit indicates there is a non-null dereference
29 // for that SSA in that block.
30 
31 class non_null_ref
32 {
33 public:
34   non_null_ref ();
35   ~non_null_ref ();
36   bool non_null_deref_p (tree name, basic_block bb);
37 private:
38   vec <bitmap> m_nn;
39   void process_name (tree name);
40   bitmap_obstack m_bitmaps;
41 };
42 
43 // This class manages a vector of pointers to ssa_block ranges.  It
44 // provides the basis for the "range on entry" cache for all
45 // SSA names.
46 
47 class block_range_cache
48 {
49 public:
50   block_range_cache ();
51   ~block_range_cache ();
52 
53   bool set_bb_range (tree name, const basic_block bb, const irange &r);
54   bool get_bb_range (irange &r, tree name, const basic_block bb);
55   bool bb_range_p (tree name, const basic_block bb);
56 
57   void dump (FILE *f);
58   void dump (FILE *f, basic_block bb, bool print_varying = true);
59 private:
60   vec<class ssa_block_ranges *> m_ssa_ranges;
61   ssa_block_ranges &get_block_ranges (tree name);
62   ssa_block_ranges *query_block_ranges (tree name);
63   irange_allocator *m_irange_allocator;
64   bitmap_obstack m_bitmaps;
65 };
66 
67 // This global cache is used with the range engine as markers for what
68 // has been visited during this incarnation.  Once the ranger evaluates
69 // a name, it is typically not re-evaluated again.
70 
71 class ssa_global_cache
72 {
73 public:
74   ssa_global_cache ();
75   ~ssa_global_cache ();
76   bool get_global_range (irange &r, tree name) const;
77   bool set_global_range (tree name, const irange &r);
78   void clear_global_range (tree name);
79   void clear ();
80   void dump (FILE *f = stderr);
81 private:
82   vec<irange *> m_tab;
83   class irange_allocator *m_irange_allocator;
84 };
85 
86 // This class provides all the caches a global ranger may need, and makes
87 // them available for gori-computes to query so outgoing edges can be
88 // properly calculated.
89 
90 class ranger_cache : public gori_compute
91 {
92 public:
93   ranger_cache (class gimple_ranger &q);
94   ~ranger_cache ();
95 
96   virtual void ssa_range_in_bb (irange &r, tree name, basic_block bb);
97   bool block_range (irange &r, basic_block bb, tree name, bool calc = true);
98 
99   bool get_global_range (irange &r, tree name) const;
100   bool get_non_stale_global_range (irange &r, tree name);
101   void set_global_range (tree name, const irange &r);
102   void register_dependency (tree name, tree dep);
103 
104   non_null_ref m_non_null;
105 
106   void dump (FILE *f, bool dump_gori = true);
107   void dump (FILE *f, basic_block bb);
108 private:
109   ssa_global_cache m_globals;
110   block_range_cache m_on_entry;
111   class temporal_cache *m_temporal;
112   void add_to_update (basic_block bb);
113   void fill_block_cache (tree name, basic_block bb, basic_block def_bb);
114   void propagate_cache (tree name);
115 
116   void propagate_updated_value (tree name, basic_block bb);
117 
118   bitmap m_propfail;
119   vec<basic_block> m_workback;
120   vec<basic_block> m_update_list;
121 
122   // Iterative "poor value" calculations.
123   struct update_record
124   {
125     basic_block bb;	// Block which value needs to be calculated in.
126     tree calc;		// SSA_NAME which needs its value calculated.
127   };
128   bool push_poor_value (basic_block bb, tree name);
129   vec<update_record> m_poor_value_list;
130   class gimple_ranger &query;
131 };
132 
133 #endif // GCC_SSA_RANGE_CACHE_H
134