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   // Query if there is any relation between SSA1 and SSA2.
  75   relation_kind query_relation (gimple *s, tree ssa1, tree ssa2,
  76                                 bool get_range = true);
  77   relation_kind query_relation (edge e, tree ssa1, tree ssa2,
  78                                 bool get_range = true);
  79   // If present, Access relation oracle for more advanced uses.
  80   inline relation_oracle *oracle () const  { return m_oracle; }
  81
  82   virtual void dump (FILE *);
  83
  84 protected:
  85   bool get_tree_range (vrange &v, tree expr, gimple *stmt);
  86   bool get_arith_expr_range (vrange &r, tree expr, gimple *stmt);
  87   relation_oracle *m_oracle;
  88 };
  89
  90 // Global ranges for SSA names using SSA_NAME_RANGE_INFO.
  91
  92 class global_range_query : public range_query
  93 {
  94 public:
  95   bool range_of_expr (vrange &r, tree expr, gimple * = NULL) override;
  96 };
  97
  98 extern global_range_query global_ranges;
  99
 100 inline range_query *
 101 get_global_range_query ()
 102 {
 103   return &global_ranges;
 104 }
 105
 106 /* Returns the currently active range access class.  When there is no active
 107    range class, global ranges are used.  Never returns null.  */
 108
 109 ATTRIBUTE_RETURNS_NONNULL inline range_query *
 110 get_range_query (const struct function *fun)
 111 {
 112   return (fun && fun->x_range_query) ? fun->x_range_query : &global_ranges;
 113 }
 114
 115 // Query the global range of NAME in function F.  Default to cfun.
 116 extern void gimple_range_global (vrange &v, tree name,
 117                                  struct function *f = cfun);
 118
 119 #endif // GCC_QUERY_H