1/* Hooks for cfg representation specific functions.
2   Copyright (C) 2003-2015 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/* Only basic-block.h includes this.  */
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, int);
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);
189extern void dump_bb (FILE *, basic_block, int, int);
190extern void dump_bb_for_graph (pretty_printer *, basic_block);
191extern void dump_flow_info (FILE *, int);
192
193extern edge redirect_edge_and_branch (edge, basic_block);
194extern basic_block redirect_edge_and_branch_force (edge, basic_block);
195extern edge redirect_edge_succ_nodup (edge, basic_block);
196extern bool can_remove_branch_p (const_edge);
197extern void remove_branch (edge);
198extern void remove_edge (edge);
199extern edge split_block (basic_block, void *);
200extern edge split_block_after_labels (basic_block);
201extern bool move_block_after (basic_block, basic_block);
202extern void delete_basic_block (basic_block);
203extern basic_block split_edge (edge);
204extern basic_block create_basic_block (void *, void *, basic_block);
205extern basic_block create_empty_bb (basic_block);
206extern bool can_merge_blocks_p (basic_block, basic_block);
207extern void merge_blocks (basic_block, basic_block);
208extern edge make_forwarder_block (basic_block, bool (*)(edge),
209				  void (*) (basic_block));
210extern basic_block force_nonfallthru (edge);
211extern void tidy_fallthru_edge (edge);
212extern void tidy_fallthru_edges (void);
213extern void predict_edge (edge e, enum br_predictor predictor, int probability);
214extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
215extern bool can_duplicate_block_p (const_basic_block);
216extern basic_block duplicate_block (basic_block, edge, basic_block);
217extern bool block_ends_with_call_p (basic_block bb);
218extern bool empty_block_p (basic_block);
219extern basic_block split_block_before_cond_jump (basic_block);
220extern bool block_ends_with_condjump_p (const_basic_block bb);
221extern int flow_call_edges_add (sbitmap);
222extern void execute_on_growing_pred (edge);
223extern void execute_on_shrinking_pred (edge);
224extern bool cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge,
225						    unsigned int ndupl,
226						    sbitmap wont_exit,
227						    edge orig,
228						    vec<edge> *to_remove,
229						    int flags);
230
231extern void lv_flush_pending_stmts (edge);
232extern void extract_cond_bb_edges (basic_block, edge *, edge*);
233extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
234				       edge);
235extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
236				    void *);
237
238extern bool can_copy_bbs_p (basic_block *, unsigned);
239extern void copy_bbs (basic_block *, unsigned, basic_block *,
240		      edge *, unsigned, edge *, struct loop *,
241		      basic_block, bool);
242
243void account_profile_record (struct profile_record *, int);
244
245/* Hooks containers.  */
246extern struct cfg_hooks gimple_cfg_hooks;
247extern struct cfg_hooks rtl_cfg_hooks;
248extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
249
250/* Declarations.  */
251extern enum ir_type current_ir_type (void);
252extern void rtl_register_cfg_hooks (void);
253extern void cfg_layout_rtl_register_cfg_hooks (void);
254extern void gimple_register_cfg_hooks (void);
255extern struct cfg_hooks get_cfg_hooks (void);
256extern void set_cfg_hooks (struct cfg_hooks);
257
258#endif /* GCC_CFGHOOKS_H */
259