gcc/value-query.h

   1 /* Support routines for value queries.
   2    Copyright (C) 2020-2023 Free Software Foundation, Inc.
   3    Contributed by Aldy Hernandez <aldyh@redhat.com> and
   4    Andrew Macleod <amacleod@redhat.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef GCC_QUERY_H
  23 #define GCC_QUERY_H
  24
  25 #include "value-relation.h"
  26
  27 // The value_query class is used by optimization passes that require
  28 // valueizing SSA names in terms of a tree value, but have no need
  29 // for ranges.
  30 //
  31 // value_of_expr must be provided.  The default for value_on_edge and
  32 // value_of_stmt is to call value_of_expr.
  33 //
  34 // This implies the valuation is global in nature.  If a pass can make
  35 // use of more specific information, it can override the other queries.
  36 //
  37 // Proper usage of the correct query in passes will enable other
  38 // valuation mechanisms to produce more precise results.
  39
  40 // The range_query class is used by optimization passes which are
  41 // range aware.
  42 //
  43 // range_of_expr must be provided.  The default for range_on_edge and
  44 // range_of_stmt is to call range_of_expr.  If a pass can make use of
  45 // more specific information, then it can override the other queries.
  46 //
  47 // The default for the value_* routines is to call the equivalent
  48 // range_* routines, check if the range is a singleton, and return it
  49 // if so.
  50 //
  51 // The get_value_range method is currently provided for compatibility
  52 // with vr-values.  It will be deprecated when possible.
  53
  54 class range_query
  55 {
  56 public:
  57   range_query ();
  58   virtual ~range_query ();
  59
  60   virtual tree value_of_expr (tree expr, gimple * = NULL);
  61   virtual tree value_on_edge (edge, tree expr);
  62   virtual tree value_of_stmt (gimple *, tree name = NULL);
  63
  64   // These are the range equivalents of the value_* methods.  Instead
  65   // of returning a singleton, they calculate a range and return it in
  66   // R.  TRUE is returned on success or FALSE if no range was found.
  67   //
  68   // Note that range_of_expr must always return TRUE unless ranges are
  69   // unsupported for EXPR's type (supports_type_p is false).
  70   virtual bool range_of_expr (vrange &r, tree expr, gimple * = NULL) = 0;
  71   virtual bool range_on_edge (vrange &r, edge, tree expr);
  72   virtual bool range_of_stmt (vrange &r, gimple *, tree name = NULL);
  73
  74   // When the IL in a stmt is changed, call this for better results.
  75   virtual void update_stmt (gimple *) { }
  76
  77   // Query if there is any relation between SSA1 and SSA2.
  78   relation_kind query_relation (gimple *s, tree ssa1, tree ssa2,
  79                                 bool get_range = true);
  80   relation_kind query_relation (edge e, tree ssa1, tree ssa2,
  81                                 bool get_range = true);
  82   // If present, Access relation oracle for more advanced uses.
  83   inline relation_oracle *oracle () const  { return m_oracle; }
  84
  85   virtual void dump (FILE *);
  86
  87 protected:
  88   bool get_tree_range (vrange &v, tree expr, gimple *stmt);
  89   bool get_arith_expr_range (vrange &r, tree expr, gimple *stmt);
  90   relation_oracle *m_oracle;
  91 };
  92
  93 // Global ranges for SSA names using SSA_NAME_RANGE_INFO.
  94
  95 class global_range_query : public range_query
  96 {
  97 public:
  98   bool range_of_expr (vrange &r, tree expr, gimple * = NULL) override;
  99 };
 100
 101 extern global_range_query global_ranges;
 102
 103 inline range_query *
 104 get_global_range_query ()
 105 {
 106   return &global_ranges;
 107 }
 108
 109 /* Returns the currently active range access class.  When there is no active
 110    range class, global ranges are used.  Never returns null.  */
 111
 112 ATTRIBUTE_RETURNS_NONNULL inline range_query *
 113 get_range_query (const struct function *fun)
 114 {
 115   return (fun && fun->x_range_query) ? fun->x_range_query : &global_ranges;
 116 }
 117
 118 // Query the global range of NAME in function F.  Default to cfun.
 119 extern void gimple_range_global (vrange &v, tree name,
 120                                  struct function *f = cfun);
 121
 122 #endif // GCC_QUERY_H