GCC Middle and Back End API Reference
tree-ssa-threadupdate.h
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1/* Communication between registering jump thread requests and
2 updating the SSA/CFG for jump threading.
3 Copyright (C) 2013-2024 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3. If not see
19<http://www.gnu.org/licenses/>. */
20
21#ifndef _TREE_SSA_THREADUPDATE_H
22#define _TREE_SSA_THREADUPDATE_H 1
23
31
32// We keep the registered jump threading opportunities in this
33// vector as edge pairs (original_edge, target_edge).
34
43
55
56// Abstract class for the jump thread registry.
57//
58// When all candidates have been registered with
59// register_jump_thread(), thread_through_all_blocks() is called to
60// update the CFG.
61
63{
64public:
65 jt_path_registry (bool backedge_threads);
66 virtual ~jt_path_registry ();
68 bool thread_through_all_blocks (bool peel_loop_headers);
71 void debug ();
72protected:
73 void debug_path (FILE *, int pathno);
75 unsigned long m_num_threaded_edges;
76private:
77 virtual bool update_cfg (bool peel_loop_headers) = 0;
80 // True if threading through back edges is allowed. This is only
81 // allowed in the generic copier in the backward threader.
84};
85
86// Forward threader path registry using a custom BB copier.
87
89{
90public:
94private:
95 bool update_cfg (bool peel_loop_headers) override;
96 void mark_threaded_blocks (bitmap threaded_blocks);
97 bool thread_block_1 (basic_block, bool noloop_only, bool joiners);
98 bool thread_block (basic_block, bool noloop_only);
100 bool may_peel_loop_headers);
101 class redirection_data *lookup_redirection_data (edge e, enum insert_option);
102
104
105 // Main data structure to hold information for duplicates of BB.
107};
108
109// Backward threader path registry using a generic BB copier.
110
112{
113public:
115private:
116 bool update_cfg (bool peel_loop_headers) override;
117 void adjust_paths_after_duplication (unsigned curr_path_num);
118 bool duplicate_thread_path (edge entry, edge exit, basic_block *region,
119 unsigned n_region, unsigned current_path_no);
120 bool rewire_first_differing_edge (unsigned path_num, unsigned edge_num);
121};
122
123// Rather than search all the edges in jump thread paths each time DOM
124// is able to simply if control statement, we build a hash table with
125// the deleted edges. We only care about the address of the edge, not
126// its contents.
128{
129 static hashval_t hash (edge e) { return htab_hash_pointer (e); }
130 static bool equal (edge e1, edge e2) { return e1 == e2; }
131};
132
133extern unsigned int estimate_threading_killed_stmts (basic_block);
134
136{
137 /* BB does not dominate latch of the LOOP. */
139 /* The LOOP is broken (there is no path from the header to its latch. */
141 /* BB dominates the latch of the LOOP. */
144
146
147// In tree-ssa-dom.cc.
148extern void free_dom_edge_info (edge);
149
150#endif
Definition tree-ssa-threadupdate.h:112
bool duplicate_thread_path(edge entry, edge exit, basic_block *region, unsigned n_region, unsigned current_path_no)
Definition tree-ssa-threadupdate.cc:2388
void adjust_paths_after_duplication(unsigned curr_path_num)
Definition tree-ssa-threadupdate.cc:2291
bool rewire_first_differing_edge(unsigned path_num, unsigned edge_num)
Definition tree-ssa-threadupdate.cc:2245
bool update_cfg(bool peel_loop_headers) override
Definition tree-ssa-threadupdate.cc:2605
back_jt_path_registry()
Definition tree-ssa-threadupdate.cc:195
Definition tree-ssa-threadupdate.h:89
fwd_jt_path_registry()
Definition tree-ssa-threadupdate.cc:183
~fwd_jt_path_registry()
Definition tree-ssa-threadupdate.cc:190
bool thread_block_1(basic_block, bool noloop_only, bool joiners)
Definition tree-ssa-threadupdate.cc:1423
hash_table< struct removed_edges > * m_removed_edges
Definition tree-ssa-threadupdate.h:103
hash_table< redirection_data > * m_redirection_data
Definition tree-ssa-threadupdate.h:106
class redirection_data * lookup_redirection_data(edge e, enum insert_option)
Definition tree-ssa-threadupdate.cc:457
bool thread_block(basic_block, bool noloop_only)
Definition tree-ssa-threadupdate.cc:1617
bool thread_through_loop_header(class loop *loop, bool may_peel_loop_headers)
Definition tree-ssa-threadupdate.cc:1698
bool update_cfg(bool peel_loop_headers) override
Definition tree-ssa-threadupdate.cc:2661
void mark_threaded_blocks(bitmap threaded_blocks)
Definition tree-ssa-threadupdate.cc:1954
void remove_jump_threads_including(edge)
Definition tree-ssa-threadupdate.cc:2561
Definition hash-table.h:375
Definition tree-ssa-threadupdate.h:63
unsigned long m_num_threaded_edges
Definition tree-ssa-threadupdate.h:75
bool cancel_invalid_paths(vec< jump_thread_edge * > &path)
Definition tree-ssa-threadupdate.cc:2754
bool thread_through_all_blocks(bool peel_loop_headers)
Definition tree-ssa-threadupdate.cc:2582
jump_thread_path_allocator m_allocator
Definition tree-ssa-threadupdate.h:79
virtual bool update_cfg(bool peel_loop_headers)=0
virtual ~jt_path_registry()
Definition tree-ssa-threadupdate.cc:178
void debug_path(FILE *, int pathno)
Definition tree-ssa-threadupdate.cc:2219
bool m_backedge_threads
Definition tree-ssa-threadupdate.h:82
DISABLE_COPY_AND_ASSIGN(jt_path_registry)
bool register_jump_thread(vec< jump_thread_edge * > *)
Definition tree-ssa-threadupdate.cc:2858
vec< jump_thread_edge * > * allocate_thread_path()
Definition tree-ssa-threadupdate.cc:209
void debug()
Definition tree-ssa-threadupdate.cc:2230
jt_path_registry(bool backedge_threads)
Definition tree-ssa-threadupdate.cc:171
void push_edge(vec< jump_thread_edge * > *path, edge, jump_thread_edge_type)
Definition tree-ssa-threadupdate.cc:201
vec< vec< jump_thread_edge * > * > m_paths
Definition tree-ssa-threadupdate.h:74
Definition tree-ssa-threadupdate.h:36
jump_thread_edge_type type
Definition tree-ssa-threadupdate.h:41
edge e
Definition tree-ssa-threadupdate.h:40
jump_thread_edge(edge e, jump_thread_edge_type t)
Definition tree-ssa-threadupdate.h:38
Definition tree-ssa-threadupdate.h:45
obstack m_obstack
Definition tree-ssa-threadupdate.h:53
jump_thread_edge * allocate_thread_edge(edge, jump_thread_edge_type)
Definition tree-ssa-threadupdate.cc:155
DISABLE_COPY_AND_ASSIGN(jump_thread_path_allocator)
~jump_thread_path_allocator()
Definition tree-ssa-threadupdate.cc:149
jump_thread_path_allocator()
Definition tree-ssa-threadupdate.cc:144
vec< jump_thread_edge * > * allocate_thread_path()
Definition tree-ssa-threadupdate.cc:163
Definition cfgloop.h:120
class edge_def * edge
Definition coretypes.h:352
class bitmap_head * bitmap
Definition coretypes.h:51
static struct obstack obstack
Definition gcc.cc:358
Definition basic-block.h:117
Definition hash-traits.h:303
Definition tree-ssa-threadupdate.cc:117
Definition tree-ssa-threadupdate.h:128
static bool equal(edge e1, edge e2)
Definition tree-ssa-threadupdate.h:130
static hashval_t hash(edge e)
Definition tree-ssa-threadupdate.h:129
Definition gengtype.h:252
Definition vec.h:450
void free_dom_edge_info(edge)
Definition tree-ssa-dom.cc:400
bb_dom_status
Definition tree-ssa-threadupdate.h:136
@ DOMST_DOMINATING
Definition tree-ssa-threadupdate.h:142
@ DOMST_LOOP_BROKEN
Definition tree-ssa-threadupdate.h:140
@ DOMST_NONDOMINATING
Definition tree-ssa-threadupdate.h:138
jump_thread_edge_type
Definition tree-ssa-threadupdate.h:25
@ EDGE_START_JUMP_THREAD
Definition tree-ssa-threadupdate.h:26
@ EDGE_COPY_SRC_JOINER_BLOCK
Definition tree-ssa-threadupdate.h:28
@ EDGE_NO_COPY_SRC_BLOCK
Definition tree-ssa-threadupdate.h:29
@ EDGE_COPY_SRC_BLOCK
Definition tree-ssa-threadupdate.h:27
enum bb_dom_status determine_bb_domination_status(class loop *, basic_block)
Definition tree-ssa-threadupdate.cc:1640
unsigned int estimate_threading_killed_stmts(basic_block)
Definition tree-ssa-threadupdate.cc:2917