1/* Hooks for cfg representation specific functions.
2 Copyright (C) 2003-2025 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <s.pop@laposte.net>
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 GCC_CFGHOOKS_H
22#define GCC_CFGHOOKS_H
23
24#include "predict.h"
25
26/* Structure to gather statistic about profile consistency, per pass.
27 An array of this structure, indexed by pass static number, is allocated
28 in passes.cc. The structure is defined here so that different CFG modes
29 can do their book-keeping via CFG hooks.
30
31 For every field[2], field[0] is the count before the pass runs, and
32 field[1] is the post-pass count. This allows us to monitor the effect
33 of each individual pass on the profile consistency.
34
35 This structure is not supposed to be used by anything other than passes.cc
36 and one CFG hook per CFG mode. */
37struct profile_record
38{
39 /* A weighted cost of the run-time of the function body. */
40 double time;
41 /* Frequency of execution of basic blocks where sum(prob) of the block's
42 predecessors doesn't match reasonably probability 1. */
43 double dyn_mismatched_prob_out;
44 /* Frequency of execution basic blocks where sum(count) of the block's
45 predecessors doesn't match reasonably well with the incoming frequency. */
46 double dyn_mismatched_count_in;
47 /* The number of basic blocks where sum(prob) of the block's predecessors
48 doesn't match reasonably probability 1. */
49 int num_mismatched_prob_out;
50 /* The number of basic blocks where sum(count) of the block's predecessors
51 doesn't match reasonably well with the incoming frequency. */
52 int num_mismatched_count_in;
53 /* A weighted cost of the size of the function body. */
54 int size;
55 /* True iff this pass actually was run. */
56 bool run;
57 bool fdo;
58};
59
60typedef int_hash <unsigned short, 0> dependence_hash;
61
62/* Optional data for duplicate_block. */
63
64class copy_bb_data
65{
66public:
67 copy_bb_data() : dependence_map (NULL) {}
68 ~copy_bb_data () { delete dependence_map; }
69
70 /* A map from the copied BBs dependence info cliques to
71 equivalents in the BBs duplicated to. */
72 hash_map<dependence_hash, unsigned short> *dependence_map;
73};
74
75struct cfg_hooks
76{
77 /* Name of the corresponding ir. */
78 const char *name;
79
80 /* Debugging. */
81 bool (*verify_flow_info) (void);
82 void (*dump_bb) (FILE *, basic_block, int, dump_flags_t);
83 void (*dump_bb_for_graph) (pretty_printer *, basic_block);
84
85 /* Basic CFG manipulation. */
86
87 /* Return new basic block. */
88 basic_block (*create_basic_block) (void *head, void *end, basic_block after);
89
90 /* Redirect edge E to the given basic block B and update underlying program
91 representation. Returns edge representing redirected branch (that may not
92 be equivalent to E in the case of duplicate edges being removed) or NULL
93 if edge is not easily redirectable for whatever reason. */
94 edge (*redirect_edge_and_branch) (edge e, basic_block b);
95
96 /* Same as the above but allows redirecting of fallthru edges. In that case
97 newly created forwarder basic block is returned. The edge must
98 not be abnormal. */
99 basic_block (*redirect_edge_and_branch_force) (edge, basic_block);
100
101 /* Returns true if it is possible to remove the edge by redirecting it
102 to the destination of the other edge going from its source. */
103 bool (*can_remove_branch_p) (const_edge);
104
105 /* Remove statements corresponding to a given basic block. */
106 void (*delete_basic_block) (basic_block);
107
108 /* Creates a new basic block just after basic block B by splitting
109 everything after specified instruction I. */
110 basic_block (*split_block) (basic_block b, void * i);
111
112 /* Move block B immediately after block A. */
113 bool (*move_block_after) (basic_block b, basic_block a);
114
115 /* Return true when blocks A and B can be merged into single basic block. */
116 bool (*can_merge_blocks_p) (basic_block a, basic_block b);
117
118 /* Merge blocks A and B. */
119 void (*merge_blocks) (basic_block a, basic_block b);
120
121 /* Predict edge E using PREDICTOR to given PROBABILITY. */
122 void (*predict_edge) (edge e, enum br_predictor predictor, int probability);
123
124 /* Return true if the one of outgoing edges is already predicted by
125 PREDICTOR. */
126 bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);
127
128 /* Return true when block A can be duplicated. */
129 bool (*can_duplicate_block_p) (const_basic_block a);
130
131 /* Duplicate block A. */
132 basic_block (*duplicate_block) (basic_block a, copy_bb_data *);
133
134 /* Higher level functions representable by primitive operations above if
135 we didn't have some oddities in RTL and Tree representations. */
136 basic_block (*split_edge) (edge);
137 void (*make_forwarder_block) (edge);
138
139 /* Try to make the edge fallthru. */
140 void (*tidy_fallthru_edge) (edge);
141
142 /* Make the edge non-fallthru. */
143 basic_block (*force_nonfallthru) (edge);
144
145 /* Say whether a block ends with a call, possibly followed by some
146 other code that must stay with the call. */
147 bool (*block_ends_with_call_p) (basic_block);
148
149 /* Say whether a block ends with a conditional branch. Switches
150 and unconditional branches do not qualify. */
151 bool (*block_ends_with_condjump_p) (const_basic_block);
152
153 /* Add fake edges to the function exit for any non constant and non noreturn
154 calls, volatile inline assembly in the bitmap of blocks specified by
155 BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
156 that were split.
157
158 The goal is to expose cases in which entering a basic block does not imply
159 that all subsequent instructions must be executed. */
160 int (*flow_call_edges_add) (sbitmap);
161
162 /* This function is called immediately after edge E is added to the
163 edge vector E->dest->preds. */
164 void (*execute_on_growing_pred) (edge);
165
166 /* This function is called immediately before edge E is removed from
167 the edge vector E->dest->preds. */
168 void (*execute_on_shrinking_pred) (edge);
169
170 /* A hook for duplicating loop in CFG, currently this is used
171 in loop versioning. */
172 bool (*cfg_hook_duplicate_loop_body_to_header_edge) (class loop *, edge,
173 unsigned, sbitmap, edge,
174 vec<edge> *, int);
175
176 /* Add condition to new basic block and update CFG used in loop
177 versioning. */
178 void (*lv_add_condition_to_bb) (basic_block, basic_block, basic_block,
179 void *);
180 /* Update the PHI nodes in case of loop versioning. */
181 void (*lv_adjust_loop_header_phi) (basic_block, basic_block,
182 basic_block, edge);
183
184 /* Given a condition BB extract the true/false taken/not taken edges
185 (depending if we are on tree's or RTL). */
186 void (*extract_cond_bb_edges) (basic_block, edge *, edge *);
187
188
189 /* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
190 E->dest (only in tree-ssa loop versioning. */
191 void (*flush_pending_stmts) (edge);
192
193 /* True if a block contains no executable instructions. */
194 bool (*empty_block_p) (basic_block);
195
196 /* Split a basic block if it ends with a conditional branch and if
197 the other part of the block is not empty. */
198 basic_block (*split_block_before_cond_jump) (basic_block);
199
200 /* Do book-keeping of a basic block for the profile consistency checker. */
201 void (*account_profile_record) (basic_block, struct profile_record *);
202};
203
204extern void verify_flow_info (void);
205
206/* Check control flow invariants, if internal consistency checks are
207 enabled. */
208
209inline void
210checking_verify_flow_info (void)
211{
212 /* TODO: Add a separate option for -fchecking=cfg. */
213 if (flag_checking)
214 verify_flow_info ();
215}
216
217extern void dump_bb (FILE *, basic_block, int, dump_flags_t);
218extern void dump_bb_for_graph (pretty_printer *, basic_block);
219extern void dump_flow_info (FILE *, dump_flags_t);
220
221extern edge redirect_edge_and_branch (edge, basic_block);
222extern basic_block redirect_edge_and_branch_force (edge, basic_block);
223extern edge redirect_edge_succ_nodup (edge, basic_block);
224extern bool can_remove_branch_p (const_edge);
225extern void remove_branch (edge);
226extern void remove_edge (edge);
227extern edge split_block (basic_block, rtx);
228extern edge split_block (basic_block, gimple *);
229extern edge split_block_after_labels (basic_block);
230extern bool move_block_after (basic_block, basic_block);
231extern void delete_basic_block (basic_block);
232extern basic_block split_edge (edge);
233extern basic_block create_basic_block (rtx, rtx, basic_block);
234extern basic_block create_basic_block (gimple_seq, basic_block);
235extern basic_block create_empty_bb (basic_block);
236extern bool can_merge_blocks_p (basic_block, basic_block);
237extern void merge_blocks (basic_block, basic_block);
238extern edge make_forwarder_block (basic_block, bool (*)(edge),
239 void (*) (basic_block));
240extern basic_block force_nonfallthru (edge);
241extern void tidy_fallthru_edge (edge);
242extern void tidy_fallthru_edges (void);
243extern void predict_edge (edge e, enum br_predictor predictor, int probability);
244extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
245extern bool can_duplicate_block_p (const_basic_block);
246extern basic_block duplicate_block (basic_block, edge, basic_block,
247 copy_bb_data * = NULL);
248extern bool block_ends_with_call_p (basic_block bb);
249extern bool empty_block_p (basic_block);
250extern basic_block split_block_before_cond_jump (basic_block);
251extern bool block_ends_with_condjump_p (const_basic_block bb);
252extern int flow_call_edges_add (sbitmap);
253extern void execute_on_growing_pred (edge);
254extern void execute_on_shrinking_pred (edge);
255extern bool
256cfg_hook_duplicate_loop_body_to_header_edge (class loop *loop, edge,
257 unsigned int ndupl,
258 sbitmap wont_exit, edge orig,
259 vec<edge> *to_remove, int flags);
260
261extern void lv_flush_pending_stmts (edge);
262extern void extract_cond_bb_edges (basic_block, edge *, edge*);
263extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
264 edge);
265extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
266 void *);
267
268extern bool can_copy_bbs_p (basic_block *, unsigned);
269extern void copy_bbs (basic_block *, unsigned, basic_block *,
270 edge *, unsigned, edge *, class loop *,
271 basic_block, bool);
272
273void profile_record_check_consistency (profile_record *);
274void profile_record_account_profile (profile_record *);
275
276/* Hooks containers. */
277extern struct cfg_hooks gimple_cfg_hooks;
278extern struct cfg_hooks rtl_cfg_hooks;
279extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
280
281/* Declarations. */
282extern enum ir_type current_ir_type (void);
283extern void rtl_register_cfg_hooks (void);
284extern void cfg_layout_rtl_register_cfg_hooks (void);
285extern void gimple_register_cfg_hooks (void);
286extern struct cfg_hooks get_cfg_hooks (void);
287extern void set_cfg_hooks (struct cfg_hooks);
288
289#endif /* GCC_CFGHOOKS_H */
290

source code of gcc/cfghooks.h