gcc/gimple-range-cache.h

   1 /* Header file for gimple ranger SSA cache.
   2    Copyright (C) 2017-2020 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   void set_bb_range (tree name, const basic_block bb, const irange &r);
  54   void set_bb_varying (tree name, const basic_block bb);
  55   bool get_bb_range (irange &r, tree name, const basic_block bb);
  56   bool bb_range_p (tree name, const basic_block bb);
  57
  58   void dump (FILE *f);
  59   void dump (FILE *f, basic_block bb, bool print_varying = true);
  60 private:
  61   vec<class ssa_block_ranges *> m_ssa_ranges;
  62   ssa_block_ranges &get_block_ranges (tree name);
  63   irange_allocator *m_irange_allocator;
  64 };
  65
  66 // This global cache is used with the range engine as markers for what
  67 // has been visited during this incarnation.  Once the ranger evaluates
  68 // a name, it is typically not re-evaluated again.
  69
  70 class ssa_global_cache
  71 {
  72 public:
  73   ssa_global_cache ();
  74   ~ssa_global_cache ();
  75   bool get_global_range (irange &r, tree name) const;
  76   void set_global_range (tree name, const irange &r);
  77   void clear_global_range (tree name);
  78   void clear ();
  79   void dump (FILE *f = stderr);
  80 private:
  81   vec<irange *> m_tab;
  82   class irange_allocator *m_irange_allocator;
  83 };
  84
  85 // This class provides all the caches a global ranger may need, and makes
  86 // them available for gori-computes to query so outgoing edges can be
  87 // properly calculated.
  88
  89 class ranger_cache : public gori_compute_cache
  90 {
  91 public:
  92   ranger_cache (class range_query &q);
  93   ~ranger_cache ();
  94
  95   virtual void ssa_range_in_bb (irange &r, tree name, basic_block bb);
  96   bool block_range (irange &r, basic_block bb, tree name, bool calc = true);
  97
  98   ssa_global_cache m_globals;
  99   block_range_cache m_on_entry;
 100   non_null_ref m_non_null;
 101 private:
 102   void add_to_update (basic_block bb);
 103   void fill_block_cache (tree name, basic_block bb, basic_block def_bb);
 104   void iterative_cache_update (tree name);
 105
 106   vec<basic_block> m_workback;
 107   vec<basic_block> m_update_list;
 108
 109   // Iterative "poor value" calculations.
 110   struct update_record
 111   {
 112     basic_block bb;     // Block which value needs to be calculated in.
 113     tree calc;          // SSA_NAME which needs its value calculated.
 114   };
 115   bool push_poor_value (basic_block bb, tree name);
 116   vec<update_record> m_poor_value_list;
 117   class range_query &query;
 118 };
 119
 120 #endif // GCC_SSA_RANGE_CACHE_H