blob: 9f2d6d92dab9e434046363f9c9f0db3e26b4a2e1 [file] [log] [blame]
/* Header file for jump threading path solver.
Copyright (C) 2021-2022 Free Software Foundation, Inc.
Contributed by Aldy Hernandez <>.
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
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
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
<>. */
// This class is a basic block path solver. Given a set of BBs
// indicating a path through the CFG, range_of_expr and range_of_stmt
// will calculate the range of an SSA or STMT as if the BBs in the
// path would have been executed in order.
// Note that the blocks are in reverse order, thus the exit block is
// path[0].
class path_range_query : public range_query
path_range_query (class gimple_ranger &ranger,
const vec<basic_block> &path,
const bitmap_head *dependencies = NULL,
bool resolve = true);
path_range_query (gimple_ranger &ranger, bool resolve = true);
virtual ~path_range_query ();
void reset_path (const vec<basic_block> &, const bitmap_head *dependencies);
bool range_of_expr (vrange &r, tree name, gimple * = NULL) override;
bool range_of_stmt (vrange &r, gimple *, tree name = NULL) override;
bool unreachable_path_p ();
void dump (FILE *) override;
void debug ();
bool internal_range_of_expr (vrange &r, tree name, gimple *);
void compute_ranges (const bitmap_head *dependencies);
void compute_exit_dependencies (bitmap_head *dependencies);
bool defined_outside_path (tree name);
void range_on_path_entry (vrange &r, tree name);
path_oracle *get_path_oracle () { return (path_oracle *)m_oracle; }
// Cache manipulation.
void set_cache (const vrange &r, tree name);
bool get_cache (vrange &r, tree name);
void clear_cache (tree name);
// Methods to compute ranges for the given path.
bool range_defined_in_block (vrange &, tree name, basic_block bb);
void compute_ranges_in_block (basic_block bb);
void compute_ranges_in_phis (basic_block bb);
void adjust_for_non_null_uses (basic_block bb);
void ssa_range_in_phi (vrange &r, gphi *phi);
void compute_outgoing_relations (basic_block bb, basic_block next);
void compute_phi_relations (basic_block bb, basic_block prev);
void maybe_register_phi_relation (gphi *, edge e);
bool add_to_exit_dependencies (tree name, bitmap dependencies);
bool exit_dependency_p (tree name);
bool ssa_defined_in_bb (tree name, basic_block bb);
bool relations_may_be_invalidated (edge);
// Path navigation.
basic_block entry_bb () { return m_path[m_path.length () - 1]; }
basic_block exit_bb () { return m_path[0]; }
basic_block curr_bb () { return m_path[m_pos]; }
basic_block prev_bb () { return m_path[m_pos + 1]; }
basic_block next_bb () { return m_path[m_pos - 1]; }
bool at_entry () { return m_pos == m_path.length () - 1; }
bool at_exit () { return m_pos == 0; }
void move_next () { --m_pos; }
// Range cache for SSA names.
ssa_global_cache *m_cache;
// Set for each SSA that has an active entry in the cache.
bitmap m_has_cache_entry;
// Path being analyzed.
auto_vec<basic_block> m_path;
// This is a list of SSA names that may have relevant context
// information for solving the final conditional along the path.
// Ranges for these SSA names are pre-calculated and cached during a
// top-down traversal of the path, and are then used to answer
// questions at the path exit.
auto_bitmap m_exit_dependencies;
// A ranger used to resolve ranges for SSA names whose values come
// from outside the path.
gimple_ranger &m_ranger;
// Current path position.
unsigned m_pos;
// Use ranger to resolve anything not known on entry.
bool m_resolve;
// Set if there were any undefined expressions while pre-calculating path.
bool m_undefined_path;