Collaboration diagram for edge_info:

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Public Types
typedef std::pair< tree, tree >	equiv_pair

Public Member Functions
	edge_info (edge)

	~edge_info ()

void	record_simple_equiv (tree, tree)

Data Fields
vec< equiv_pair >	simple_equivalences

vec< cond_equivalence >	cond_equivalences

Private Member Functions
void	derive_equivalences (tree, tree, int)

Detailed Description

SSA Dominator optimizations for trees
   Copyright (C) 2001-2025 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 file implements optimizations on the dominator tree.

Structure for recording edge equivalences.

Computing and storing the edge equivalences instead of creating
them on-demand can save significant amounts of time, particularly
for pathological cases involving switch statements.

These structures live for a single iteration of the dominator
optimizer in the edge's AUX field.  At the end of an iteration we
free each of these structures.

Member Typedef Documentation

◆ equiv_pair

typedef std::pair<tree, tree> edge_info::equiv_pair

Constructor & Destructor Documentation

◆ edge_info()

edge_info::edge_info ( edge e )

Constructor for EDGE_INFO.  An EDGE_INFO instance is always
associated with an edge E.

References cond_equivalences, free_dom_edge_info(), simple_equivalences, and vNULL.

◆ ~edge_info()

edge_info::~edge_info ( void )


Destructor just needs to release the vectors.

References cond_equivalences, and simple_equivalences.

Member Function Documentation

◆ derive_equivalences()

void edge_info::derive_equivalences	(	tree	name,
		tree	value,
		int	recursion_limit )

private

NAME is known to have the value VALUE, which must be a constant.

Walk through its use-def chain to see if there are other equivalences
we might be able to derive.

RECURSION_LIMIT controls how far back we recurse through the use-def
chains.

References boolean_type_node, build2(), build_one_cst(), build_zero_cst(), CASE_CONVERT, cond_equivalences, derive_equivalences(), fold_binary, fold_build1, fold_convert, gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), int_fits_type_p(), integer_onep(), integer_zerop(), INTEGRAL_TYPE_P, invert_truthvalue, is_gimple_assign(), record_conditions(), simple_equivalences, SSA_NAME_DEF_STMT, ssa_name_has_boolean_range(), tcc_comparison, TREE_CODE, TREE_CODE_CLASS, TREE_INT_CST_LOW, TREE_TYPE, and TYPE_PRECISION.