1/* Hooks for cfg representation specific functions.
2 Copyright (C) 2003-2017 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.c. 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.c
36 and one CFG hook per CFG mode. */
37struct profile_record
38{
39 /* The number of basic blocks where sum(freq) of the block's predecessors
40 doesn't match reasonably well with the incoming frequency. */
41 int num_mismatched_freq_in[2];
42 /* Likewise for a basic block's successors. */
43 int num_mismatched_freq_out[2];
44 /* The number of basic blocks where sum(count) of the block's predecessors
45 doesn't match reasonably well with the incoming frequency. */
46 int num_mismatched_count_in[2];
47 /* Likewise for a basic block's successors. */
48 int num_mismatched_count_out[2];
49 /* A weighted cost of the run-time of the function body. */
50 gcov_type time[2];
51 /* A weighted cost of the size of the function body. */
52 int size[2];
53 /* True iff this pass actually was run. */
54 bool run;
55};
56
57
58struct cfg_hooks
59{
60 /* Name of the corresponding ir. */
61 const char *name;
62
63 /* Debugging. */
64 int (*verify_flow_info) (void);
65 void (*dump_bb) (FILE *, basic_block, int, dump_flags_t);
66 void (*dump_bb_for_graph) (pretty_printer *, basic_block);
67
68 /* Basic CFG manipulation. */
69
70 /* Return new basic block. */
71 basic_block (*create_basic_block) (void *head, void *end, basic_block after);
72
73 /* Redirect edge E to the given basic block B and update underlying program
74 representation. Returns edge representing redirected branch (that may not
75 be equivalent to E in the case of duplicate edges being removed) or NULL
76 if edge is not easily redirectable for whatever reason. */
77 edge (*redirect_edge_and_branch) (edge e, basic_block b);
78
79 /* Same as the above but allows redirecting of fallthru edges. In that case
80 newly created forwarder basic block is returned. The edge must
81 not be abnormal. */
82 basic_block (*redirect_edge_and_branch_force) (edge, basic_block);
83
84 /* Returns true if it is possible to remove the edge by redirecting it
85 to the destination of the other edge going from its source. */
86 bool (*can_remove_branch_p) (const_edge);
87
88 /* Remove statements corresponding to a given basic block. */
89 void (*delete_basic_block) (basic_block);
90
91 /* Creates a new basic block just after basic block B by splitting
92 everything after specified instruction I. */
93 basic_block (*split_block) (basic_block b, void * i);
94
95 /* Move block B immediately after block A. */
96 bool (*move_block_after) (basic_block b, basic_block a);
97
98 /* Return true when blocks A and B can be merged into single basic block. */
99 bool (*can_merge_blocks_p) (basic_block a, basic_block b);
100
101 /* Merge blocks A and B. */
102 void (*merge_blocks) (basic_block a, basic_block b);
103
104 /* Predict edge E using PREDICTOR to given PROBABILITY. */
105 void (*predict_edge) (edge e, enum br_predictor predictor, int probability);
106
107 /* Return true if the one of outgoing edges is already predicted by
108 PREDICTOR. */
109 bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);
110
111 /* Return true when block A can be duplicated. */
112 bool (*can_duplicate_block_p) (const_basic_block a);
113
114 /* Duplicate block A. */
115 basic_block (*duplicate_block) (basic_block a);
116
117 /* Higher level functions representable by primitive operations above if
118 we didn't have some oddities in RTL and Tree representations. */
119 basic_block (*split_edge) (edge);
120 void (*make_forwarder_block) (edge);
121
122 /* Try to make the edge fallthru. */
123 void (*tidy_fallthru_edge) (edge);
124
125 /* Make the edge non-fallthru. */
126 basic_block (*force_nonfallthru) (edge);
127
128 /* Say whether a block ends with a call, possibly followed by some
129 other code that must stay with the call. */
130 bool (*block_ends_with_call_p) (basic_block);
131
132 /* Say whether a block ends with a conditional branch. Switches
133 and unconditional branches do not qualify. */
134 bool (*block_ends_with_condjump_p) (const_basic_block);
135
136 /* Add fake edges to the function exit for any non constant and non noreturn
137 calls, volatile inline assembly in the bitmap of blocks specified by
138 BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
139 that were split.
140
141 The goal is to expose cases in which entering a basic block does not imply
142 that all subsequent instructions must be executed. */
143 int (*flow_call_edges_add) (sbitmap);
144
145 /* This function is called immediately after edge E is added to the
146 edge vector E->dest->preds. */
147 void (*execute_on_growing_pred) (edge);
148
149 /* This function is called immediately before edge E is removed from
150 the edge vector E->dest->preds. */
151 void (*execute_on_shrinking_pred) (edge);
152
153 /* A hook for duplicating loop in CFG, currently this is used
154 in loop versioning. */
155 bool (*cfg_hook_duplicate_loop_to_header_edge) (struct loop *, edge,
156 unsigned, sbitmap,
157 edge, vec<edge> *,
158 int);
159
160 /* Add condition to new basic block and update CFG used in loop
161 versioning. */
162 void (*lv_add_condition_to_bb) (basic_block, basic_block, basic_block,
163 void *);
164 /* Update the PHI nodes in case of loop versioning. */
165 void (*lv_adjust_loop_header_phi) (basic_block, basic_block,
166 basic_block, edge);
167
168 /* Given a condition BB extract the true/false taken/not taken edges
169 (depending if we are on tree's or RTL). */
170 void (*extract_cond_bb_edges) (basic_block, edge *, edge *);
171
172
173 /* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
174 E->dest (only in tree-ssa loop versioning. */
175 void (*flush_pending_stmts) (edge);
176
177 /* True if a block contains no executable instructions. */
178 bool (*empty_block_p) (basic_block);
179
180 /* Split a basic block if it ends with a conditional branch and if
181 the other part of the block is not empty. */
182 basic_block (*split_block_before_cond_jump) (basic_block);
183
184 /* Do book-keeping of a basic block for the profile consistency checker. */
185 void (*account_profile_record) (basic_block, int, struct profile_record *);
186};
187
188extern void verify_flow_info (void);
189
190/* Check control flow invariants, if internal consistency checks are
191 enabled. */
192
193static inline void
194checking_verify_flow_info (void)
195{
196 /* TODO: Add a separate option for -fchecking=cfg. */
197 if (flag_checking)
198 verify_flow_info ();
199}
200
201extern void dump_bb (FILE *, basic_block, int, dump_flags_t);
202extern void dump_bb_for_graph (pretty_printer *, basic_block);
203extern void dump_flow_info (FILE *, dump_flags_t);
204
205extern edge redirect_edge_and_branch (edge, basic_block);
206extern basic_block redirect_edge_and_branch_force (edge, basic_block);
207extern edge redirect_edge_succ_nodup (edge, basic_block);
208extern bool can_remove_branch_p (const_edge);
209extern void remove_branch (edge);
210extern void remove_edge (edge);
211extern edge split_block (basic_block, rtx);
212extern edge split_block (basic_block, gimple *);
213extern edge split_block_after_labels (basic_block);
214extern bool move_block_after (basic_block, basic_block);
215extern void delete_basic_block (basic_block);
216extern basic_block split_edge (edge);
217extern basic_block create_basic_block (rtx, rtx, basic_block);
218extern basic_block create_basic_block (gimple_seq, basic_block);
219extern basic_block create_empty_bb (basic_block);
220extern bool can_merge_blocks_p (basic_block, basic_block);
221extern void merge_blocks (basic_block, basic_block);
222extern edge make_forwarder_block (basic_block, bool (*)(edge),
223 void (*) (basic_block));
224extern basic_block force_nonfallthru (edge);
225extern void tidy_fallthru_edge (edge);
226extern void tidy_fallthru_edges (void);
227extern void predict_edge (edge e, enum br_predictor predictor, int probability);
228extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
229extern bool can_duplicate_block_p (const_basic_block);
230extern basic_block duplicate_block (basic_block, edge, basic_block);
231extern bool block_ends_with_call_p (basic_block bb);
232extern bool empty_block_p (basic_block);
233extern basic_block split_block_before_cond_jump (basic_block);
234extern bool block_ends_with_condjump_p (const_basic_block bb);
235extern int flow_call_edges_add (sbitmap);
236extern void execute_on_growing_pred (edge);
237extern void execute_on_shrinking_pred (edge);
238extern bool cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge,
239 unsigned int ndupl,
240 sbitmap wont_exit,
241 edge orig,
242 vec<edge> *to_remove,
243 int flags);
244
245extern void lv_flush_pending_stmts (edge);
246extern void extract_cond_bb_edges (basic_block, edge *, edge*);
247extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
248 edge);
249extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
250 void *);
251
252extern bool can_copy_bbs_p (basic_block *, unsigned);
253extern void copy_bbs (basic_block *, unsigned, basic_block *,
254 edge *, unsigned, edge *, struct loop *,
255 basic_block, bool);
256
257void account_profile_record (struct profile_record *, int);
258
259/* Hooks containers. */
260extern struct cfg_hooks gimple_cfg_hooks;
261extern struct cfg_hooks rtl_cfg_hooks;
262extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
263
264/* Declarations. */
265extern enum ir_type current_ir_type (void);
266extern void rtl_register_cfg_hooks (void);
267extern void cfg_layout_rtl_register_cfg_hooks (void);
268extern void gimple_register_cfg_hooks (void);
269extern struct cfg_hooks get_cfg_hooks (void);
270extern void set_cfg_hooks (struct cfg_hooks);
271
272#endif /* GCC_CFGHOOKS_H */
273