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/* Support routines for value queries.
Copyright (C) 2020-2021 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
// The value_query class is used by optimization passes that require
// valueizing SSA names in terms of a tree value, but have no neeed
// 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.
class value_query
{
public:
value_query () { }
// Return the singleton expression for NAME at a gimple statement,
// or NULL if none found.
virtual tree value_of_expr (tree name, gimple * = NULL) = 0;
// Return the singleton expression for NAME at an edge, or NULL if
// none found.
virtual tree value_on_edge (edge, tree name);
// Return the singleton expression for the LHS of a gimple
// statement, assuming an (optional) initial value of NAME. Returns
// NULL if none found.
//
// Note that this method calculates the range the LHS would have
// *after* the statement has executed.
virtual tree value_of_stmt (gimple *, tree name = NULL);
private:
DISABLE_COPY_AND_ASSIGN (value_query);
};
// 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 value_query
{
public:
range_query ();
virtual ~range_query ();
virtual tree value_of_expr (tree name, gimple * = NULL) OVERRIDE;
virtual tree value_on_edge (edge, tree name) OVERRIDE;
virtual tree value_of_stmt (gimple *, tree name = NULL) OVERRIDE;
// 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 NAME's type (supports_type_p is false).
virtual bool range_of_expr (irange &r, tree name, gimple * = NULL) = 0;
virtual bool range_on_edge (irange &r, edge, tree name);
virtual bool range_of_stmt (irange &r, gimple *, tree name = NULL);
// DEPRECATED: This method is used from vr-values. The plan is to
// rewrite all uses of it to the above API.
virtual const class value_range_equiv *get_value_range (const_tree,
gimple * = NULL);
protected:
class value_range_equiv *allocate_value_range_equiv ();
void free_value_range_equiv (class value_range_equiv *);
private:
class equiv_allocator *equiv_alloc;
};
#endif // GCC_QUERY_H