dom_walker Class Reference

#include <domwalk.h>

Inheritance diagram for dom_walker:

Collaboration diagram for dom_walker:

Public Types
enum	reachability { ALL_BLOCKS , REACHABLE_BLOCKS , REACHABLE_BLOCKS_PRESERVING_FLAGS }

Public Member Functions
	dom_walker (cdi_direction direction, enum reachability=ALL_BLOCKS, int *bb_index_to_rpo=NULL)
	~dom_walker ()
void	walk (basic_block)
virtual edge	before_dom_children (basic_block)
virtual void	after_dom_children (basic_block)

Static Public Attributes
static const edge	STOP = (edge)-1

Private Member Functions
bool	bb_reachable (struct function *, basic_block)
void	propagate_unreachable_to_edges (basic_block, FILE *, dump_flags_t)

Private Attributes
enum cdi_direction	m_dom_direction: 2
enum reachability	m_reachability: 2
bool	m_user_bb_to_rpo
basic_block	m_unreachable_dom
int *	m_bb_to_rpo

Detailed Description

Generic dominator tree walker
   Copyright (C) 2003-2024 Free Software Foundation, Inc.
   Contributed by Diego Novillo <dnovillo@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/>.   

This is the main class for the dominator walker. It is expected that consumers will have a custom class inheriting from it, which will over ride at least one of before_dom_children and after_dom_children to implement the custom behavior.

Member Enumeration Documentation

reachability

enum dom_walker::reachability

Enumerator
ALL_BLOCKS
REACHABLE_BLOCKS
REACHABLE_BLOCKS_PRESERVING_FLAGS

Constructor & Destructor Documentation

dom_walker()

dom_walker::dom_walker	(	cdi_direction	direction,
		enum reachability	reachability = ALL_BLOCKS,
		int *	bb_index_to_rpo = NULL )

Constructor for a dom walker.   

~dom_walker()

dom_walker::~dom_walker

(

)

Destructor.   

References free(), m_bb_to_rpo, and m_user_bb_to_rpo.

Member Function Documentation

after_dom_children()

virtual void dom_walker::after_dom_children ( basic_block )

inlinevirtual

Reimplemented in dom_opt_dom_walker, eliminate_dom_walker, nontrapping_dom_walker, rewrite_dom_walker, rewrite_update_dom_walker, strlen_pass, substitute_and_fold_dom_walker, and uncprop_dom_walker.

Referenced by walk().

bb_reachable()

bool dom_walker::bb_reachable ( struct function * fun, basic_block bb )

private

Return TRUE if BB is reachable, false otherwise.   

References ALL_BLOCKS, CDI_DOMINATORS, dominated_by_p(), ENTRY_BLOCK_PTR_FOR_FN, FOR_EACH_EDGE, m_reachability, m_unreachable_dom, and basic_block_def::preds.

Referenced by walk().

before_dom_children()

virtual edge dom_walker::before_dom_children ( basic_block )

inlinevirtual

Reimplemented in analysis_dom_walker, check_array_bounds_dom_walker, dom_opt_dom_walker, eliminate_dom_walker, find_candidates_dom_walker, find_comparison_dom_walker, ipcp_modif_dom_walker, mark_def_dom_walker, nontrapping_dom_walker, rewrite_dom_walker, rewrite_update_dom_walker, strlen_pass, substitute_and_fold_dom_walker, and uncprop_dom_walker.

References NULL.

Referenced by walk().

propagate_unreachable_to_edges()

void dom_walker::propagate_unreachable_to_edges ( basic_block bb, FILE * dump_file, dump_flags_t dump_flags )

private

BB has been determined to be unreachable.  Propagate that property
to incoming and outgoing edges of BB as appropriate.   

References CDI_DOMINATORS, dominated_by_p(), dump_file, dump_flags, FOR_EACH_EDGE, basic_block_def::index, m_unreachable_dom, basic_block_def::preds, basic_block_def::succs, and TDF_DETAILS.

Referenced by walk().

walk()

void dom_walker::walk

(

basic_block

bb

)

Recursively walk the dominator tree.
BB is the basic block we are currently visiting.   

References after_dom_children(), bb_reachable(), before_dom_children(), CDI_DOMINATORS, cfun, dump_file, dump_flags, EDGE_COUNT, ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, first_dom_son(), FOR_EACH_EDGE, free(), i, last_basic_block_for_fn, m_bb_to_rpo, m_dom_direction, m_reachability, m_unreachable_dom, m_user_bb_to_rpo, n_basic_blocks_for_fn, next_dom_son(), NULL, pre_and_rev_post_order_compute(), basic_block_def::preds, propagate_unreachable_to_edges(), REACHABLE_BLOCKS, set_all_edges_as_executable(), sort_bbs_postorder(), STOP, basic_block_def::succs, and worklist.

Referenced by array_bounds_checker::check(), eliminate_with_rpo_vn(), find_comparisons(), get_non_trapping(), ipa_analyze_node(), ipcp_transform_function(), rewrite_blocks(), and substitute_and_fold_engine::substitute_and_fold().

Field Documentation

m_bb_to_rpo

int* dom_walker::m_bb_to_rpo

private

Referenced by walk(), and ~dom_walker().

m_dom_direction

enum cdi_direction dom_walker::m_dom_direction

private

Referenced by walk().

m_reachability

enum reachability dom_walker::m_reachability

private

Referenced by bb_reachable(), and walk().

m_unreachable_dom

basic_block dom_walker::m_unreachable_dom

private

Referenced by bb_reachable(), propagate_unreachable_to_edges(), and walk().

m_user_bb_to_rpo

bool dom_walker::m_user_bb_to_rpo

private

Referenced by walk(), and ~dom_walker().

STOP

const edge dom_walker::STOP = (edge)-1

static

Referenced by rewrite_update_dom_walker::before_dom_children(), and walk().

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The documentation for this class was generated from the following files:

• domwalk.h
• domwalk.cc