value-query.h

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/* Support routines for value queries.
   Copyright (C) 2020-2024 Free Software Foundation, Inc.
   Contributed by Aldy Hernandez <aldyh@redhat.com> and
   Andrew Macleod <amacleod@redhat.com>.
 
This file is part of GCC.
 
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
 
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */
 
#ifndef GCC_QUERY_H
#define GCC_QUERY_H
 
#include "value-relation.h"
 
// The value_query class is used by optimization passes that require
// valueizing SSA names in terms of a tree value, but have no need
// for ranges.
//
// value_of_expr must be provided.  The default for value_on_edge and
// value_of_stmt is to call value_of_expr.
//
// This implies the valuation is global in nature.  If a pass can make
// use of more specific information, it can override the other queries.
//
// Proper usage of the correct query in passes will enable other
// valuation mechanisms to produce more precise results.
 
// The range_query class is used by optimization passes which are
// range aware.
//
// range_of_expr must be provided.  The default for range_on_edge and
// range_of_stmt is to call range_of_expr.  If a pass can make use of
// more specific information, then it can override the other queries.
//
// The default for the value_* routines is to call the equivalent
// range_* routines, check if the range is a singleton, and return it
// if so.
//
// The get_value_range method is currently provided for compatibility
// with vr-values.  It will be deprecated when possible.
 
class range_query
{
public:
  range_query ();
  virtual ~range_query ();
 
  virtual tree value_of_expr (tree expr, gimple * = NULL);
  virtual tree value_on_edge (edge, tree expr);
  virtual tree value_of_stmt (gimple *, tree name = NULL);
  virtual tree value_on_entry (basic_block, tree expr);
  virtual tree value_on_exit (basic_block, tree expr);
 
  // These are the range equivalents of the value_* methods.  Instead
  // of returning a singleton, they calculate a range and return it in
  // R.  TRUE is returned on success or FALSE if no range was found.
  //
  // Note that range_of_expr must always return TRUE unless ranges are
  // unsupported for EXPR's type (supports_type_p is false).
  virtual bool range_of_expr (vrange &r, tree expr, gimple * = NULL) = 0;
  virtual bool range_on_edge (vrange &r, edge, tree expr);
  virtual bool range_of_stmt (vrange &r, gimple *, tree name = NULL);
  virtual bool range_on_entry (vrange &r, basic_block bb, tree expr);
  virtual bool range_on_exit (vrange &r, basic_block bb, tree expr);
 
  // Query if there is any relation between SSA1 and SSA2.
  relation_kind query_relation (gimple *s, tree ssa1, tree ssa2,
                                bool get_range = true);
  relation_kind query_relation (edge e, tree ssa1, tree ssa2,
                                bool get_range = true);
  // If present, Access relation oracle for more advanced uses.
  inline relation_oracle *oracle () const  { return m_oracle; }
 
  virtual void dump (FILE *);
 
protected:
  bool get_tree_range (vrange &v, tree expr, gimple *stmt,
                       basic_block bbentry = NULL, basic_block bbexit = NULL);
  bool invoke_range_of_expr (vrange &v, tree expr, gimple *stmt,
                             basic_block bbentry, basic_block bbexit);
  bool get_arith_expr_range (vrange &r, tree expr, gimple *stmt);
  relation_oracle *m_oracle;
};
 
// Global ranges for SSA names using SSA_NAME_RANGE_INFO.
 
class global_range_query : public range_query
{
public:
  bool range_of_expr (vrange &r, tree expr, gimple * = NULL) override;
};
 
extern global_range_query global_ranges;
 
inline range_query *
get_global_range_query ()
{
  return &global_ranges;
}
 
/* Returns the currently active range access class.  When there is no active
   range class, global ranges are used.  Never returns null.  */
 
ATTRIBUTE_RETURNS_NONNULL inline range_query *
get_range_query (const struct function *fun)
{
  return (fun && fun->x_range_query) ? fun->x_range_query : &global_ranges;
}
 
// Query the global range of NAME in function F.  Default to cfun.
extern void gimple_range_global (vrange &v, tree name,
                                 struct function *f = cfun);
 
#endif // GCC_QUERY_H