xref: /netbsd-src/external/gpl3/gcc/dist/gcc/cfghooks.h (revision b1e838363e3c6fc78a55519254d99869742dd33c)
1 /* Hooks for cfg representation specific functions.
2    Copyright (C) 2003-2022 Free Software Foundation, Inc.
3    Contributed by Sebastian Pop <s.pop@laposte.net>
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11 
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 GNU General Public License for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along 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.  */
37 struct 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 
60 typedef int_hash <unsigned short, 0> dependence_hash;
61 
62 /* Optional data for duplicate_block.   */
63 
64 class copy_bb_data
65 {
66 public:
copy_bb_data()67   copy_bb_data() : dependence_map (NULL) {}
~copy_bb_data()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 
75 struct cfg_hooks
76 {
77   /* Name of the corresponding ir.  */
78   const char *name;
79 
80   /* Debugging.  */
81   int (*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 
204 extern void verify_flow_info (void);
205 
206 /* Check control flow invariants, if internal consistency checks are
207    enabled.  */
208 
209 static inline void
checking_verify_flow_info(void)210 checking_verify_flow_info (void)
211 {
212   /* TODO: Add a separate option for -fchecking=cfg.  */
213   if (flag_checking)
214     verify_flow_info ();
215 }
216 
217 extern void dump_bb (FILE *, basic_block, int, dump_flags_t);
218 extern void dump_bb_for_graph (pretty_printer *, basic_block);
219 extern void dump_flow_info (FILE *, dump_flags_t);
220 
221 extern edge redirect_edge_and_branch (edge, basic_block);
222 extern basic_block redirect_edge_and_branch_force (edge, basic_block);
223 extern edge redirect_edge_succ_nodup (edge, basic_block);
224 extern bool can_remove_branch_p (const_edge);
225 extern void remove_branch (edge);
226 extern void remove_edge (edge);
227 extern edge split_block (basic_block, rtx);
228 extern edge split_block (basic_block, gimple *);
229 extern edge split_block_after_labels (basic_block);
230 extern bool move_block_after (basic_block, basic_block);
231 extern void delete_basic_block (basic_block);
232 extern basic_block split_edge (edge);
233 extern basic_block create_basic_block (rtx, rtx, basic_block);
234 extern basic_block create_basic_block (gimple_seq, basic_block);
235 extern basic_block create_empty_bb (basic_block);
236 extern bool can_merge_blocks_p (basic_block, basic_block);
237 extern void merge_blocks (basic_block, basic_block);
238 extern edge make_forwarder_block (basic_block, bool (*)(edge),
239 				  void (*) (basic_block));
240 extern basic_block force_nonfallthru (edge);
241 extern void tidy_fallthru_edge (edge);
242 extern void tidy_fallthru_edges (void);
243 extern void predict_edge (edge e, enum br_predictor predictor, int probability);
244 extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
245 extern bool can_duplicate_block_p (const_basic_block);
246 extern basic_block duplicate_block (basic_block, edge, basic_block,
247 				    copy_bb_data * = NULL);
248 extern bool block_ends_with_call_p (basic_block bb);
249 extern bool empty_block_p (basic_block);
250 extern basic_block split_block_before_cond_jump (basic_block);
251 extern bool block_ends_with_condjump_p (const_basic_block bb);
252 extern int flow_call_edges_add (sbitmap);
253 extern void execute_on_growing_pred (edge);
254 extern void execute_on_shrinking_pred (edge);
255 extern bool
256 cfg_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 
261 extern void lv_flush_pending_stmts (edge);
262 extern void extract_cond_bb_edges (basic_block, edge *, edge*);
263 extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
264 				       edge);
265 extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
266 				    void *);
267 
268 extern bool can_copy_bbs_p (basic_block *, unsigned);
269 extern void copy_bbs (basic_block *, unsigned, basic_block *,
270 		      edge *, unsigned, edge *, class loop *,
271 		      basic_block, bool);
272 
273 void profile_record_check_consistency (profile_record *);
274 void profile_record_account_profile (profile_record *);
275 
276 /* Hooks containers.  */
277 extern struct cfg_hooks gimple_cfg_hooks;
278 extern struct cfg_hooks rtl_cfg_hooks;
279 extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
280 
281 /* Declarations.  */
282 extern enum ir_type current_ir_type (void);
283 extern void rtl_register_cfg_hooks (void);
284 extern void cfg_layout_rtl_register_cfg_hooks (void);
285 extern void gimple_register_cfg_hooks (void);
286 extern struct cfg_hooks get_cfg_hooks (void);
287 extern void set_cfg_hooks (struct cfg_hooks);
288 
289 #endif /* GCC_CFGHOOKS_H */
290