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       1              : /* Header file for gimple range inference.
       2              :    Copyright (C) 2022-2026 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_GIMPLE_RANGE_SIDE_H
      22              : #define GCC_GIMPLE_RANGE_SIDE_H
      23              : 
      24              : // Inferred ranges are ranges which are applied to use operands as a by product
      25              : // of executing an operation.
      26              : 
      27              : // This class manages an on-demand summary of inferred ranges for a statement.
      28              : // It can be instantiated as required and provides a list of inferred ranges.
      29              : // New inferred ranges should be added in the constructor of this class.
      30              : //
      31              : // There are 2 main instantiations.
      32              : // gimple_range_infer (gimple *s, range_query *q, bool use_range_ops)
      33              : //   S is the statement being queried.
      34              : //   Q is a range-query object which is used to resolve any ranges that
      35              : //      might be required.  This defaults to NULL which maps to the
      36              : //      global_range_query, which is what most passes will want.
      37              : //      Ranger internally will pass the cache's range-query which is a
      38              : //      read-only query and prevents any additional lookup.
      39              : //   USE_RANGEOPS is a boolean flag which defaults to false.  if TRUE,
      40              : //      range-ops is invoked to see if any additional side effects are seen
      41              : //      based on the stmt.  ie .x = y * 2 will reigster a side effect for Y
      42              : //      which is [-INF/2 , +INF/2].  It is not on by default because it
      43              : //      is a relatively expensive operation to do on every statement, and
      44              : //      ranger will already incorporate that range for Y via GORI most of the
      45              : //      time that it matters.  Individual passes may have use for it however.
      46              : //      PR 113879 is an example where this can be of use.
      47              : //
      48              : // gimple_range_infer (tree name, vrange &r)
      49              : // This instantiation simply create an inferred range record directly.
      50              : //   NAME is the SSA_NAME to create the record for
      51              : //   R is the range for NAME.
      52              : //
      53              : // Once a gimple_infer_range record has been created, the API is simple:
      54              : //   num ()    - The number of inferred ranges in this record.
      55              : //   name (i)  - The i'th SSA_NAME in this record.
      56              : //   range (i) - The range of the i'th SSA_NAME.
      57              : 
      58   3911214604 : class gimple_infer_range
      59              : {
      60              : public:
      61              :   gimple_infer_range (gimple *s, range_query *q = NULL,
      62              :                       bool use_rangeops = false);
      63              :   gimple_infer_range (tree name, vrange &r);
      64    427967771 :   inline unsigned num () const { return num_args; }
      65     40324947 :   inline tree name (unsigned index) const
      66     40324947 :     { gcc_checking_assert (index < num_args); return m_names[index]; }
      67     43907549 :   inline const vrange& range (unsigned index) const
      68     43907549 :     { gcc_checking_assert (index < num_args); return m_ranges[index]; }
      69              : private:
      70              :   void add_range (tree name, vrange &range);
      71              :   void add_nonzero (tree name);
      72              :   void check_assume_func (gcall *call);
      73              :   unsigned num_args;
      74              :   static const int size_limit = 10;
      75              :   tree m_names[size_limit];
      76              :   value_range m_ranges[size_limit];
      77              :   inline void bump_index () { if (num_args < size_limit - 1) num_args++; }
      78              :   friend class non_null_wrapper;
      79              : };
      80              : 
      81              : // This is the basic infer oracle API.  Default functionaility does nothing.
      82              : 
      83              : class infer_range_oracle
      84              : {
      85              : public:
      86     27881050 :   infer_range_oracle () { }
      87     28450231 :   virtual ~infer_range_oracle () { }
      88            0 :   virtual void add_ranges (gimple *, gimple_infer_range &) { }
      89            0 :   virtual bool has_range_p (basic_block, tree = NULL_TREE) { return false; }
      90            0 :   virtual bool maybe_adjust_range (vrange &, tree, basic_block)
      91            0 :       { return false; }
      92              : };
      93              : 
      94              : // This class manages a list of inferred ranges for each basic block.
      95              : // As inferences are made, they can be registered to a block and later
      96              : // queried via a DOM search.
      97              : // When DO_SEARCH is TRUE,  immediate uses chains are followed the first time
      98              : // a name is referenced and block populated if there are any inferred ranges.
      99              : // range_query Q is the range_query to use for any range lookups. It defaults
     100              : // to NULL which maps to the global_range_query.  This is what most passes
     101              : // will want to use. Ranger invokes it with the cache's internal query which
     102              : // can provide better ranges during a DOM walk.
     103              : //
     104              : // add_ranges is used to add inferred range IR assocaited with stmt S.
     105              : // has_range_p is used to check if NAME has an inferred range in block BB.
     106              : // maybe_adjust_range will adjust the range R to incorporate any inferred
     107              : //   range NAME may have in block BB.  If there are on inferred ranges in
     108              : //   block BB, then R will be unchanged, otherwise the ranges are intersected.
     109              : 
     110              : class infer_range_manager : public infer_range_oracle
     111              : {
     112              : public:
     113              :   infer_range_manager (bool do_search, range_query *q = NULL);
     114              :   virtual ~infer_range_manager ();
     115              :   virtual void add_ranges (gimple *s, gimple_infer_range &ir);
     116              :   virtual bool has_range_p (basic_block bb, tree name = NULL_TREE);
     117              :   virtual bool maybe_adjust_range (vrange &r, tree name, basic_block bb);
     118              : private:
     119              :   void add_range (tree name, gimple *s, const vrange &r);
     120              :   void add_nonzero (tree name, gimple *s);
     121              :   class exit_range_head
     122              :   {
     123              :   public:
     124              :     bitmap m_names;             // list of names with an outgoing range.
     125              :     class exit_range *head;
     126              :     int m_num_ranges;
     127              :     exit_range *find_ptr (tree name);
     128              :   };
     129              :   void register_all_uses (tree name);
     130              :   vec <exit_range_head> m_on_exit;
     131              :   const vrange &get_nonzero (tree name);
     132              :   vec <vrange *> m_nonzero;
     133              :   bitmap m_seen;
     134              :   bitmap_obstack m_bitmaps;
     135              :   struct obstack m_list_obstack;
     136              :   class vrange_allocator *m_range_allocator;
     137              :   range_query *m_query;
     138              : };
     139              : #endif // GCC_GIMPLE_RANGE_SIDE_H