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295ae817 | 1 | /* Basic block reordering routines for the GNU compiler. |
62e5bf5d RS |
2 | Copyright (C) 2000, 2002, 2003, 2004, 2005, 2006, 2007 |
3 | Free Software Foundation, Inc. | |
295ae817 | 4 | |
1322177d | 5 | This file is part of GCC. |
295ae817 | 6 | |
1322177d LB |
7 | GCC is free software; you can redistribute it and/or modify it |
8 | under the terms of the GNU General Public License as published by | |
9dcd6f09 | 9 | the Free Software Foundation; either version 3, or (at your option) |
295ae817 JE |
10 | any later version. |
11 | ||
1322177d LB |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
295ae817 JE |
16 | |
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
295ae817 | 20 | |
aa634f11 JZ |
21 | /* This (greedy) algorithm constructs traces in several rounds. |
22 | The construction starts from "seeds". The seed for the first round | |
23 | is the entry point of function. When there are more than one seed | |
24 | that one is selected first that has the lowest key in the heap | |
25 | (see function bb_to_key). Then the algorithm repeatedly adds the most | |
26 | probable successor to the end of a trace. Finally it connects the traces. | |
27 | ||
28 | There are two parameters: Branch Threshold and Exec Threshold. | |
29 | If the edge to a successor of the actual basic block is lower than | |
30 | Branch Threshold or the frequency of the successor is lower than | |
31 | Exec Threshold the successor will be the seed in one of the next rounds. | |
32 | Each round has these parameters lower than the previous one. | |
33 | The last round has to have these parameters set to zero | |
34 | so that the remaining blocks are picked up. | |
35 | ||
36 | The algorithm selects the most probable successor from all unvisited | |
37 | successors and successors that have been added to this trace. | |
38 | The other successors (that has not been "sent" to the next round) will be | |
39 | other seeds for this round and the secondary traces will start in them. | |
40 | If the successor has not been visited in this trace it is added to the trace | |
41 | (however, there is some heuristic for simple branches). | |
42 | If the successor has been visited in this trace the loop has been found. | |
43 | If the loop has many iterations the loop is rotated so that the | |
44 | source block of the most probable edge going out from the loop | |
45 | is the last block of the trace. | |
46 | If the loop has few iterations and there is no edge from the last block of | |
47 | the loop going out from loop the loop header is duplicated. | |
48 | Finally, the construction of the trace is terminated. | |
49 | ||
50 | When connecting traces it first checks whether there is an edge from the | |
51 | last block of one trace to the first block of another trace. | |
52 | When there are still some unconnected traces it checks whether there exists | |
53 | a basic block BB such that BB is a successor of the last bb of one trace | |
54 | and BB is a predecessor of the first block of another trace. In this case, | |
55 | BB is duplicated and the traces are connected through this duplicate. | |
56 | The rest of traces are simply connected so there will be a jump to the | |
57 | beginning of the rest of trace. | |
58 | ||
59 | ||
60 | References: | |
61 | ||
62 | "Software Trace Cache" | |
63 | A. Ramirez, J. Larriba-Pey, C. Navarro, J. Torrellas and M. Valero; 1999 | |
64 | http://citeseer.nj.nec.com/15361.html | |
65 | ||
295ae817 JE |
66 | */ |
67 | ||
68 | #include "config.h" | |
69 | #include "system.h" | |
4977bab6 ZW |
70 | #include "coretypes.h" |
71 | #include "tm.h" | |
295ae817 | 72 | #include "rtl.h" |
7932a3db | 73 | #include "regs.h" |
295ae817 | 74 | #include "flags.h" |
38700cee | 75 | #include "timevar.h" |
295ae817 | 76 | #include "output.h" |
d56a8211 | 77 | #include "cfglayout.h" |
aa634f11 | 78 | #include "fibheap.h" |
e4ec2cac | 79 | #include "target.h" |
750054a2 | 80 | #include "function.h" |
ef482a86 | 81 | #include "tm_p.h" |
750054a2 CT |
82 | #include "obstack.h" |
83 | #include "expr.h" | |
bbcb0c05 | 84 | #include "params.h" |
4c714dd4 | 85 | #include "toplev.h" |
ef330312 | 86 | #include "tree-pass.h" |
6fb5fa3c | 87 | #include "df.h" |
ef330312 PB |
88 | |
89 | #ifndef HAVE_conditional_execution | |
90 | #define HAVE_conditional_execution 0 | |
91 | #endif | |
295ae817 | 92 | |
750054a2 CT |
93 | /* The number of rounds. In most cases there will only be 4 rounds, but |
94 | when partitioning hot and cold basic blocks into separate sections of | |
95 | the .o file there will be an extra round.*/ | |
96 | #define N_ROUNDS 5 | |
aa634f11 | 97 | |
ef482a86 | 98 | /* Stubs in case we don't have a return insn. |
c22cacf3 | 99 | We have to check at runtime too, not only compiletime. */ |
ef482a86 AT |
100 | |
101 | #ifndef HAVE_return | |
102 | #define HAVE_return 0 | |
103 | #define gen_return() NULL_RTX | |
104 | #endif | |
105 | ||
106 | ||
aa634f11 | 107 | /* Branch thresholds in thousandths (per mille) of the REG_BR_PROB_BASE. */ |
750054a2 | 108 | static int branch_threshold[N_ROUNDS] = {400, 200, 100, 0, 0}; |
aa634f11 JZ |
109 | |
110 | /* Exec thresholds in thousandths (per mille) of the frequency of bb 0. */ | |
750054a2 | 111 | static int exec_threshold[N_ROUNDS] = {500, 200, 50, 0, 0}; |
aa634f11 JZ |
112 | |
113 | /* If edge frequency is lower than DUPLICATION_THRESHOLD per mille of entry | |
114 | block the edge destination is not duplicated while connecting traces. */ | |
115 | #define DUPLICATION_THRESHOLD 100 | |
116 | ||
117 | /* Length of unconditional jump instruction. */ | |
118 | static int uncond_jump_length; | |
119 | ||
120 | /* Structure to hold needed information for each basic block. */ | |
121 | typedef struct bbro_basic_block_data_def | |
122 | { | |
123 | /* Which trace is the bb start of (-1 means it is not a start of a trace). */ | |
124 | int start_of_trace; | |
125 | ||
126 | /* Which trace is the bb end of (-1 means it is not an end of a trace). */ | |
127 | int end_of_trace; | |
128 | ||
87c8b4be CT |
129 | /* Which trace is the bb in? */ |
130 | int in_trace; | |
131 | ||
aa634f11 JZ |
132 | /* Which heap is BB in (if any)? */ |
133 | fibheap_t heap; | |
134 | ||
135 | /* Which heap node is BB in (if any)? */ | |
136 | fibnode_t node; | |
137 | } bbro_basic_block_data; | |
138 | ||
139 | /* The current size of the following dynamic array. */ | |
140 | static int array_size; | |
141 | ||
142 | /* The array which holds needed information for basic blocks. */ | |
143 | static bbro_basic_block_data *bbd; | |
144 | ||
145 | /* To avoid frequent reallocation the size of arrays is greater than needed, | |
146 | the number of elements is (not less than) 1.25 * size_wanted. */ | |
147 | #define GET_ARRAY_SIZE(X) ((((X) / 4) + 1) * 5) | |
148 | ||
149 | /* Free the memory and set the pointer to NULL. */ | |
298e6adc | 150 | #define FREE(P) (gcc_assert (P), free (P), P = 0) |
aa634f11 JZ |
151 | |
152 | /* Structure for holding information about a trace. */ | |
153 | struct trace | |
154 | { | |
155 | /* First and last basic block of the trace. */ | |
156 | basic_block first, last; | |
157 | ||
158 | /* The round of the STC creation which this trace was found in. */ | |
159 | int round; | |
160 | ||
161 | /* The length (i.e. the number of basic blocks) of the trace. */ | |
162 | int length; | |
163 | }; | |
164 | ||
165 | /* Maximum frequency and count of one of the entry blocks. */ | |
cd735ab8 KH |
166 | static int max_entry_frequency; |
167 | static gcov_type max_entry_count; | |
aa634f11 | 168 | |
295ae817 | 169 | /* Local function prototypes. */ |
4682ae04 AJ |
170 | static void find_traces (int *, struct trace *); |
171 | static basic_block rotate_loop (edge, struct trace *, int); | |
172 | static void mark_bb_visited (basic_block, int); | |
173 | static void find_traces_1_round (int, int, gcov_type, struct trace *, int *, | |
750054a2 | 174 | int, fibheap_t *, int); |
4682ae04 AJ |
175 | static basic_block copy_bb (basic_block, edge, basic_block, int); |
176 | static fibheapkey_t bb_to_key (basic_block); | |
750054a2 | 177 | static bool better_edge_p (basic_block, edge, int, int, int, int, edge); |
4682ae04 AJ |
178 | static void connect_traces (int, struct trace *); |
179 | static bool copy_bb_p (basic_block, int); | |
180 | static int get_uncond_jump_length (void); | |
750054a2 | 181 | static bool push_to_next_round_p (basic_block, int, int, int, gcov_type); |
639d3040 | 182 | static void find_rarely_executed_basic_blocks_and_crossing_edges (edge **, |
750054a2 CT |
183 | int *, |
184 | int *); | |
750054a2 CT |
185 | static void add_labels_and_missing_jumps (edge *, int); |
186 | static void add_reg_crossing_jump_notes (void); | |
187 | static void fix_up_fall_thru_edges (void); | |
188 | static void fix_edges_for_rarely_executed_code (edge *, int); | |
189 | static void fix_crossing_conditional_branches (void); | |
190 | static void fix_crossing_unconditional_branches (void); | |
f008a564 | 191 | \f |
750054a2 CT |
192 | /* Check to see if bb should be pushed into the next round of trace |
193 | collections or not. Reasons for pushing the block forward are 1). | |
194 | If the block is cold, we are doing partitioning, and there will be | |
195 | another round (cold partition blocks are not supposed to be | |
196 | collected into traces until the very last round); or 2). There will | |
197 | be another round, and the basic block is not "hot enough" for the | |
198 | current round of trace collection. */ | |
199 | ||
200 | static bool | |
201 | push_to_next_round_p (basic_block bb, int round, int number_of_rounds, | |
202 | int exec_th, gcov_type count_th) | |
203 | { | |
204 | bool there_exists_another_round; | |
750054a2 CT |
205 | bool block_not_hot_enough; |
206 | ||
207 | there_exists_another_round = round < number_of_rounds - 1; | |
750054a2 | 208 | |
c22cacf3 | 209 | block_not_hot_enough = (bb->frequency < exec_th |
750054a2 CT |
210 | || bb->count < count_th |
211 | || probably_never_executed_bb_p (bb)); | |
212 | ||
87c8b4be CT |
213 | if (there_exists_another_round |
214 | && block_not_hot_enough) | |
750054a2 | 215 | return true; |
c22cacf3 | 216 | else |
750054a2 CT |
217 | return false; |
218 | } | |
219 | ||
aa634f11 JZ |
220 | /* Find the traces for Software Trace Cache. Chain each trace through |
221 | RBI()->next. Store the number of traces to N_TRACES and description of | |
222 | traces to TRACES. */ | |
295ae817 | 223 | |
f008a564 | 224 | static void |
4682ae04 | 225 | find_traces (int *n_traces, struct trace *traces) |
295ae817 | 226 | { |
aa634f11 | 227 | int i; |
750054a2 | 228 | int number_of_rounds; |
aa634f11 | 229 | edge e; |
628f6a4e | 230 | edge_iterator ei; |
aa634f11 JZ |
231 | fibheap_t heap; |
232 | ||
750054a2 CT |
233 | /* Add one extra round of trace collection when partitioning hot/cold |
234 | basic blocks into separate sections. The last round is for all the | |
235 | cold blocks (and ONLY the cold blocks). */ | |
236 | ||
237 | number_of_rounds = N_ROUNDS - 1; | |
750054a2 | 238 | |
aa634f11 JZ |
239 | /* Insert entry points of function into heap. */ |
240 | heap = fibheap_new (); | |
241 | max_entry_frequency = 0; | |
242 | max_entry_count = 0; | |
628f6a4e | 243 | FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) |
aa634f11 JZ |
244 | { |
245 | bbd[e->dest->index].heap = heap; | |
246 | bbd[e->dest->index].node = fibheap_insert (heap, bb_to_key (e->dest), | |
247 | e->dest); | |
248 | if (e->dest->frequency > max_entry_frequency) | |
249 | max_entry_frequency = e->dest->frequency; | |
250 | if (e->dest->count > max_entry_count) | |
251 | max_entry_count = e->dest->count; | |
252 | } | |
253 | ||
254 | /* Find the traces. */ | |
750054a2 | 255 | for (i = 0; i < number_of_rounds; i++) |
aa634f11 JZ |
256 | { |
257 | gcov_type count_threshold; | |
f008a564 | 258 | |
c263766c RH |
259 | if (dump_file) |
260 | fprintf (dump_file, "STC - round %d\n", i + 1); | |
aa634f11 JZ |
261 | |
262 | if (max_entry_count < INT_MAX / 1000) | |
263 | count_threshold = max_entry_count * exec_threshold[i] / 1000; | |
264 | else | |
265 | count_threshold = max_entry_count / 1000 * exec_threshold[i]; | |
266 | ||
267 | find_traces_1_round (REG_BR_PROB_BASE * branch_threshold[i] / 1000, | |
268 | max_entry_frequency * exec_threshold[i] / 1000, | |
750054a2 CT |
269 | count_threshold, traces, n_traces, i, &heap, |
270 | number_of_rounds); | |
aa634f11 JZ |
271 | } |
272 | fibheap_delete (heap); | |
273 | ||
c263766c | 274 | if (dump_file) |
aa634f11 JZ |
275 | { |
276 | for (i = 0; i < *n_traces; i++) | |
277 | { | |
278 | basic_block bb; | |
c263766c | 279 | fprintf (dump_file, "Trace %d (round %d): ", i + 1, |
aa634f11 | 280 | traces[i].round + 1); |
370369e1 | 281 | for (bb = traces[i].first; bb != traces[i].last; bb = bb->aux) |
c263766c RH |
282 | fprintf (dump_file, "%d [%d] ", bb->index, bb->frequency); |
283 | fprintf (dump_file, "%d [%d]\n", bb->index, bb->frequency); | |
aa634f11 | 284 | } |
c263766c | 285 | fflush (dump_file); |
aa634f11 JZ |
286 | } |
287 | } | |
288 | ||
289 | /* Rotate loop whose back edge is BACK_EDGE in the tail of trace TRACE | |
290 | (with sequential number TRACE_N). */ | |
291 | ||
292 | static basic_block | |
4682ae04 | 293 | rotate_loop (edge back_edge, struct trace *trace, int trace_n) |
aa634f11 JZ |
294 | { |
295 | basic_block bb; | |
296 | ||
297 | /* Information about the best end (end after rotation) of the loop. */ | |
298 | basic_block best_bb = NULL; | |
299 | edge best_edge = NULL; | |
300 | int best_freq = -1; | |
301 | gcov_type best_count = -1; | |
302 | /* The best edge is preferred when its destination is not visited yet | |
303 | or is a start block of some trace. */ | |
304 | bool is_preferred = false; | |
305 | ||
306 | /* Find the most frequent edge that goes out from current trace. */ | |
307 | bb = back_edge->dest; | |
f008a564 RH |
308 | do |
309 | { | |
aa634f11 | 310 | edge e; |
628f6a4e BE |
311 | edge_iterator ei; |
312 | ||
313 | FOR_EACH_EDGE (e, ei, bb->succs) | |
aa634f11 | 314 | if (e->dest != EXIT_BLOCK_PTR |
370369e1 | 315 | && e->dest->il.rtl->visited != trace_n |
aa634f11 JZ |
316 | && (e->flags & EDGE_CAN_FALLTHRU) |
317 | && !(e->flags & EDGE_COMPLEX)) | |
318 | { | |
319 | if (is_preferred) | |
320 | { | |
321 | /* The best edge is preferred. */ | |
370369e1 | 322 | if (!e->dest->il.rtl->visited |
aa634f11 JZ |
323 | || bbd[e->dest->index].start_of_trace >= 0) |
324 | { | |
325 | /* The current edge E is also preferred. */ | |
326 | int freq = EDGE_FREQUENCY (e); | |
327 | if (freq > best_freq || e->count > best_count) | |
328 | { | |
329 | best_freq = freq; | |
330 | best_count = e->count; | |
331 | best_edge = e; | |
332 | best_bb = bb; | |
333 | } | |
334 | } | |
335 | } | |
336 | else | |
337 | { | |
370369e1 | 338 | if (!e->dest->il.rtl->visited |
aa634f11 JZ |
339 | || bbd[e->dest->index].start_of_trace >= 0) |
340 | { | |
341 | /* The current edge E is preferred. */ | |
342 | is_preferred = true; | |
343 | best_freq = EDGE_FREQUENCY (e); | |
344 | best_count = e->count; | |
345 | best_edge = e; | |
346 | best_bb = bb; | |
347 | } | |
348 | else | |
349 | { | |
350 | int freq = EDGE_FREQUENCY (e); | |
351 | if (!best_edge || freq > best_freq || e->count > best_count) | |
352 | { | |
353 | best_freq = freq; | |
354 | best_count = e->count; | |
355 | best_edge = e; | |
356 | best_bb = bb; | |
357 | } | |
358 | } | |
359 | } | |
360 | } | |
370369e1 | 361 | bb = bb->aux; |
aa634f11 JZ |
362 | } |
363 | while (bb != back_edge->dest); | |
364 | ||
365 | if (best_bb) | |
366 | { | |
367 | /* Rotate the loop so that the BEST_EDGE goes out from the last block of | |
368 | the trace. */ | |
369 | if (back_edge->dest == trace->first) | |
370 | { | |
370369e1 | 371 | trace->first = best_bb->aux; |
aa634f11 JZ |
372 | } |
373 | else | |
374 | { | |
375 | basic_block prev_bb; | |
ca7fd9cd | 376 | |
aa634f11 | 377 | for (prev_bb = trace->first; |
370369e1 JH |
378 | prev_bb->aux != back_edge->dest; |
379 | prev_bb = prev_bb->aux) | |
aa634f11 | 380 | ; |
370369e1 | 381 | prev_bb->aux = best_bb->aux; |
aa634f11 JZ |
382 | |
383 | /* Try to get rid of uncond jump to cond jump. */ | |
c5cbcccf | 384 | if (single_succ_p (prev_bb)) |
aa634f11 | 385 | { |
c5cbcccf | 386 | basic_block header = single_succ (prev_bb); |
aa634f11 JZ |
387 | |
388 | /* Duplicate HEADER if it is a small block containing cond jump | |
389 | in the end. */ | |
9fb32434 | 390 | if (any_condjump_p (BB_END (header)) && copy_bb_p (header, 0) |
c22cacf3 | 391 | && !find_reg_note (BB_END (header), REG_CROSSING_JUMP, |
9fb32434 | 392 | NULL_RTX)) |
c5cbcccf | 393 | copy_bb (header, single_succ_edge (prev_bb), prev_bb, trace_n); |
aa634f11 JZ |
394 | } |
395 | } | |
396 | } | |
397 | else | |
398 | { | |
399 | /* We have not found suitable loop tail so do no rotation. */ | |
400 | best_bb = back_edge->src; | |
295ae817 | 401 | } |
370369e1 | 402 | best_bb->aux = NULL; |
aa634f11 | 403 | return best_bb; |
f008a564 | 404 | } |
295ae817 | 405 | |
aa634f11 JZ |
406 | /* This function marks BB that it was visited in trace number TRACE. */ |
407 | ||
408 | static void | |
4682ae04 | 409 | mark_bb_visited (basic_block bb, int trace) |
aa634f11 | 410 | { |
370369e1 | 411 | bb->il.rtl->visited = trace; |
aa634f11 JZ |
412 | if (bbd[bb->index].heap) |
413 | { | |
414 | fibheap_delete_node (bbd[bb->index].heap, bbd[bb->index].node); | |
415 | bbd[bb->index].heap = NULL; | |
416 | bbd[bb->index].node = NULL; | |
417 | } | |
418 | } | |
419 | ||
420 | /* One round of finding traces. Find traces for BRANCH_TH and EXEC_TH i.e. do | |
421 | not include basic blocks their probability is lower than BRANCH_TH or their | |
422 | frequency is lower than EXEC_TH into traces (or count is lower than | |
423 | COUNT_TH). It stores the new traces into TRACES and modifies the number of | |
424 | traces *N_TRACES. Sets the round (which the trace belongs to) to ROUND. It | |
425 | expects that starting basic blocks are in *HEAP and at the end it deletes | |
426 | *HEAP and stores starting points for the next round into new *HEAP. */ | |
427 | ||
428 | static void | |
4682ae04 AJ |
429 | find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, |
430 | struct trace *traces, int *n_traces, int round, | |
750054a2 | 431 | fibheap_t *heap, int number_of_rounds) |
aa634f11 JZ |
432 | { |
433 | /* Heap for discarded basic blocks which are possible starting points for | |
434 | the next round. */ | |
435 | fibheap_t new_heap = fibheap_new (); | |
436 | ||
437 | while (!fibheap_empty (*heap)) | |
438 | { | |
439 | basic_block bb; | |
440 | struct trace *trace; | |
441 | edge best_edge, e; | |
442 | fibheapkey_t key; | |
628f6a4e | 443 | edge_iterator ei; |
aa634f11 JZ |
444 | |
445 | bb = fibheap_extract_min (*heap); | |
446 | bbd[bb->index].heap = NULL; | |
447 | bbd[bb->index].node = NULL; | |
448 | ||
c263766c RH |
449 | if (dump_file) |
450 | fprintf (dump_file, "Getting bb %d\n", bb->index); | |
aa634f11 | 451 | |
750054a2 | 452 | /* If the BB's frequency is too low send BB to the next round. When |
c22cacf3 MS |
453 | partitioning hot/cold blocks into separate sections, make sure all |
454 | the cold blocks (and ONLY the cold blocks) go into the (extra) final | |
455 | round. */ | |
750054a2 | 456 | |
c22cacf3 | 457 | if (push_to_next_round_p (bb, round, number_of_rounds, exec_th, |
750054a2 | 458 | count_th)) |
aa634f11 JZ |
459 | { |
460 | int key = bb_to_key (bb); | |
461 | bbd[bb->index].heap = new_heap; | |
462 | bbd[bb->index].node = fibheap_insert (new_heap, key, bb); | |
463 | ||
c263766c RH |
464 | if (dump_file) |
465 | fprintf (dump_file, | |
aa634f11 JZ |
466 | " Possible start point of next round: %d (key: %d)\n", |
467 | bb->index, key); | |
468 | continue; | |
469 | } | |
470 | ||
471 | trace = traces + *n_traces; | |
472 | trace->first = bb; | |
473 | trace->round = round; | |
474 | trace->length = 0; | |
87c8b4be | 475 | bbd[bb->index].in_trace = *n_traces; |
aa634f11 JZ |
476 | (*n_traces)++; |
477 | ||
478 | do | |
479 | { | |
480 | int prob, freq; | |
934677f9 | 481 | bool ends_in_call; |
aa634f11 JZ |
482 | |
483 | /* The probability and frequency of the best edge. */ | |
484 | int best_prob = INT_MIN / 2; | |
485 | int best_freq = INT_MIN / 2; | |
486 | ||
487 | best_edge = NULL; | |
488 | mark_bb_visited (bb, *n_traces); | |
489 | trace->length++; | |
490 | ||
c263766c RH |
491 | if (dump_file) |
492 | fprintf (dump_file, "Basic block %d was visited in trace %d\n", | |
aa634f11 JZ |
493 | bb->index, *n_traces - 1); |
494 | ||
c22cacf3 | 495 | ends_in_call = block_ends_with_call_p (bb); |
934677f9 | 496 | |
aa634f11 | 497 | /* Select the successor that will be placed after BB. */ |
628f6a4e | 498 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 | 499 | { |
298e6adc | 500 | gcc_assert (!(e->flags & EDGE_FAKE)); |
aa634f11 JZ |
501 | |
502 | if (e->dest == EXIT_BLOCK_PTR) | |
503 | continue; | |
504 | ||
370369e1 JH |
505 | if (e->dest->il.rtl->visited |
506 | && e->dest->il.rtl->visited != *n_traces) | |
aa634f11 JZ |
507 | continue; |
508 | ||
87c8b4be | 509 | if (BB_PARTITION (e->dest) != BB_PARTITION (bb)) |
750054a2 CT |
510 | continue; |
511 | ||
aa634f11 | 512 | prob = e->probability; |
1651e640 | 513 | freq = e->dest->frequency; |
aa634f11 | 514 | |
934677f9 RH |
515 | /* The only sensible preference for a call instruction is the |
516 | fallthru edge. Don't bother selecting anything else. */ | |
517 | if (ends_in_call) | |
518 | { | |
519 | if (e->flags & EDGE_CAN_FALLTHRU) | |
520 | { | |
521 | best_edge = e; | |
522 | best_prob = prob; | |
523 | best_freq = freq; | |
524 | } | |
525 | continue; | |
526 | } | |
527 | ||
aa634f11 | 528 | /* Edge that cannot be fallthru or improbable or infrequent |
89dbed81 | 529 | successor (i.e. it is unsuitable successor). */ |
aa634f11 | 530 | if (!(e->flags & EDGE_CAN_FALLTHRU) || (e->flags & EDGE_COMPLEX) |
1651e640 PH |
531 | || prob < branch_th || EDGE_FREQUENCY (e) < exec_th |
532 | || e->count < count_th) | |
aa634f11 JZ |
533 | continue; |
534 | ||
750054a2 CT |
535 | /* If partitioning hot/cold basic blocks, don't consider edges |
536 | that cross section boundaries. */ | |
537 | ||
538 | if (better_edge_p (bb, e, prob, freq, best_prob, best_freq, | |
539 | best_edge)) | |
aa634f11 JZ |
540 | { |
541 | best_edge = e; | |
542 | best_prob = prob; | |
543 | best_freq = freq; | |
544 | } | |
545 | } | |
546 | ||
c8717368 | 547 | /* If the best destination has multiple predecessors, and can be |
6d9cc15b JZ |
548 | duplicated cheaper than a jump, don't allow it to be added |
549 | to a trace. We'll duplicate it when connecting traces. */ | |
628f6a4e | 550 | if (best_edge && EDGE_COUNT (best_edge->dest->preds) >= 2 |
6d9cc15b JZ |
551 | && copy_bb_p (best_edge->dest, 0)) |
552 | best_edge = NULL; | |
553 | ||
aa634f11 | 554 | /* Add all non-selected successors to the heaps. */ |
628f6a4e | 555 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 JZ |
556 | { |
557 | if (e == best_edge | |
558 | || e->dest == EXIT_BLOCK_PTR | |
370369e1 | 559 | || e->dest->il.rtl->visited) |
aa634f11 JZ |
560 | continue; |
561 | ||
562 | key = bb_to_key (e->dest); | |
563 | ||
564 | if (bbd[e->dest->index].heap) | |
565 | { | |
566 | /* E->DEST is already in some heap. */ | |
567 | if (key != bbd[e->dest->index].node->key) | |
568 | { | |
c263766c | 569 | if (dump_file) |
aa634f11 | 570 | { |
c263766c | 571 | fprintf (dump_file, |
aa634f11 JZ |
572 | "Changing key for bb %d from %ld to %ld.\n", |
573 | e->dest->index, | |
574 | (long) bbd[e->dest->index].node->key, | |
575 | key); | |
576 | } | |
577 | fibheap_replace_key (bbd[e->dest->index].heap, | |
578 | bbd[e->dest->index].node, key); | |
579 | } | |
580 | } | |
581 | else | |
582 | { | |
583 | fibheap_t which_heap = *heap; | |
584 | ||
585 | prob = e->probability; | |
586 | freq = EDGE_FREQUENCY (e); | |
587 | ||
588 | if (!(e->flags & EDGE_CAN_FALLTHRU) | |
589 | || (e->flags & EDGE_COMPLEX) | |
590 | || prob < branch_th || freq < exec_th | |
591 | || e->count < count_th) | |
592 | { | |
750054a2 CT |
593 | /* When partitioning hot/cold basic blocks, make sure |
594 | the cold blocks (and only the cold blocks) all get | |
595 | pushed to the last round of trace collection. */ | |
596 | ||
c22cacf3 | 597 | if (push_to_next_round_p (e->dest, round, |
750054a2 CT |
598 | number_of_rounds, |
599 | exec_th, count_th)) | |
aa634f11 JZ |
600 | which_heap = new_heap; |
601 | } | |
295ae817 | 602 | |
aa634f11 JZ |
603 | bbd[e->dest->index].heap = which_heap; |
604 | bbd[e->dest->index].node = fibheap_insert (which_heap, | |
605 | key, e->dest); | |
295ae817 | 606 | |
c263766c | 607 | if (dump_file) |
aa634f11 | 608 | { |
c263766c | 609 | fprintf (dump_file, |
aa634f11 JZ |
610 | " Possible start of %s round: %d (key: %ld)\n", |
611 | (which_heap == new_heap) ? "next" : "this", | |
612 | e->dest->index, (long) key); | |
613 | } | |
614 | ||
615 | } | |
616 | } | |
617 | ||
618 | if (best_edge) /* Suitable successor was found. */ | |
619 | { | |
370369e1 | 620 | if (best_edge->dest->il.rtl->visited == *n_traces) |
aa634f11 JZ |
621 | { |
622 | /* We do nothing with one basic block loops. */ | |
623 | if (best_edge->dest != bb) | |
624 | { | |
625 | if (EDGE_FREQUENCY (best_edge) | |
626 | > 4 * best_edge->dest->frequency / 5) | |
627 | { | |
628 | /* The loop has at least 4 iterations. If the loop | |
629 | header is not the first block of the function | |
630 | we can rotate the loop. */ | |
631 | ||
632 | if (best_edge->dest != ENTRY_BLOCK_PTR->next_bb) | |
633 | { | |
c263766c | 634 | if (dump_file) |
aa634f11 | 635 | { |
c263766c | 636 | fprintf (dump_file, |
aa634f11 JZ |
637 | "Rotating loop %d - %d\n", |
638 | best_edge->dest->index, bb->index); | |
639 | } | |
370369e1 | 640 | bb->aux = best_edge->dest; |
c22cacf3 MS |
641 | bbd[best_edge->dest->index].in_trace = |
642 | (*n_traces) - 1; | |
aa634f11 JZ |
643 | bb = rotate_loop (best_edge, trace, *n_traces); |
644 | } | |
645 | } | |
646 | else | |
647 | { | |
648 | /* The loop has less than 4 iterations. */ | |
649 | ||
c5cbcccf | 650 | if (single_succ_p (bb) |
51027369 | 651 | && copy_bb_p (best_edge->dest, !optimize_size)) |
aa634f11 JZ |
652 | { |
653 | bb = copy_bb (best_edge->dest, best_edge, bb, | |
654 | *n_traces); | |
87c8b4be | 655 | trace->length++; |
aa634f11 JZ |
656 | } |
657 | } | |
658 | } | |
659 | ||
660 | /* Terminate the trace. */ | |
661 | break; | |
662 | } | |
663 | else | |
664 | { | |
665 | /* Check for a situation | |
666 | ||
667 | A | |
668 | /| | |
669 | B | | |
670 | \| | |
671 | C | |
672 | ||
673 | where | |
674 | EDGE_FREQUENCY (AB) + EDGE_FREQUENCY (BC) | |
675 | >= EDGE_FREQUENCY (AC). | |
676 | (i.e. 2 * B->frequency >= EDGE_FREQUENCY (AC) ) | |
677 | Best ordering is then A B C. | |
678 | ||
679 | This situation is created for example by: | |
680 | ||
681 | if (A) B; | |
682 | C; | |
683 | ||
684 | */ | |
685 | ||
628f6a4e | 686 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 JZ |
687 | if (e != best_edge |
688 | && (e->flags & EDGE_CAN_FALLTHRU) | |
689 | && !(e->flags & EDGE_COMPLEX) | |
370369e1 | 690 | && !e->dest->il.rtl->visited |
c5cbcccf | 691 | && single_pred_p (e->dest) |
bd454efd | 692 | && !(e->flags & EDGE_CROSSING) |
87c8b4be | 693 | && single_succ_p (e->dest) |
c5cbcccf ZD |
694 | && (single_succ_edge (e->dest)->flags |
695 | & EDGE_CAN_FALLTHRU) | |
696 | && !(single_succ_edge (e->dest)->flags & EDGE_COMPLEX) | |
697 | && single_succ (e->dest) == best_edge->dest | |
aa634f11 JZ |
698 | && 2 * e->dest->frequency >= EDGE_FREQUENCY (best_edge)) |
699 | { | |
700 | best_edge = e; | |
c263766c RH |
701 | if (dump_file) |
702 | fprintf (dump_file, "Selecting BB %d\n", | |
aa634f11 JZ |
703 | best_edge->dest->index); |
704 | break; | |
705 | } | |
706 | ||
370369e1 | 707 | bb->aux = best_edge->dest; |
87c8b4be | 708 | bbd[best_edge->dest->index].in_trace = (*n_traces) - 1; |
aa634f11 JZ |
709 | bb = best_edge->dest; |
710 | } | |
711 | } | |
712 | } | |
713 | while (best_edge); | |
714 | trace->last = bb; | |
715 | bbd[trace->first->index].start_of_trace = *n_traces - 1; | |
716 | bbd[trace->last->index].end_of_trace = *n_traces - 1; | |
717 | ||
718 | /* The trace is terminated so we have to recount the keys in heap | |
719 | (some block can have a lower key because now one of its predecessors | |
720 | is an end of the trace). */ | |
628f6a4e | 721 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 JZ |
722 | { |
723 | if (e->dest == EXIT_BLOCK_PTR | |
370369e1 | 724 | || e->dest->il.rtl->visited) |
aa634f11 JZ |
725 | continue; |
726 | ||
727 | if (bbd[e->dest->index].heap) | |
728 | { | |
729 | key = bb_to_key (e->dest); | |
730 | if (key != bbd[e->dest->index].node->key) | |
731 | { | |
c263766c | 732 | if (dump_file) |
aa634f11 | 733 | { |
c263766c | 734 | fprintf (dump_file, |
aa634f11 JZ |
735 | "Changing key for bb %d from %ld to %ld.\n", |
736 | e->dest->index, | |
737 | (long) bbd[e->dest->index].node->key, key); | |
738 | } | |
739 | fibheap_replace_key (bbd[e->dest->index].heap, | |
740 | bbd[e->dest->index].node, | |
741 | key); | |
742 | } | |
743 | } | |
744 | } | |
745 | } | |
746 | ||
747 | fibheap_delete (*heap); | |
748 | ||
749 | /* "Return" the new heap. */ | |
750 | *heap = new_heap; | |
751 | } | |
752 | ||
753 | /* Create a duplicate of the basic block OLD_BB and redirect edge E to it, add | |
754 | it to trace after BB, mark OLD_BB visited and update pass' data structures | |
755 | (TRACE is a number of trace which OLD_BB is duplicated to). */ | |
295ae817 | 756 | |
f008a564 | 757 | static basic_block |
4682ae04 | 758 | copy_bb (basic_block old_bb, edge e, basic_block bb, int trace) |
f008a564 | 759 | { |
aa634f11 JZ |
760 | basic_block new_bb; |
761 | ||
b9a66240 | 762 | new_bb = duplicate_block (old_bb, e, bb); |
076c7ab8 | 763 | BB_COPY_PARTITION (new_bb, old_bb); |
9fb32434 | 764 | |
298e6adc | 765 | gcc_assert (e->dest == new_bb); |
370369e1 | 766 | gcc_assert (!e->dest->il.rtl->visited); |
298e6adc | 767 | |
c263766c RH |
768 | if (dump_file) |
769 | fprintf (dump_file, | |
aa634f11 JZ |
770 | "Duplicated bb %d (created bb %d)\n", |
771 | old_bb->index, new_bb->index); | |
370369e1 JH |
772 | new_bb->il.rtl->visited = trace; |
773 | new_bb->aux = bb->aux; | |
774 | bb->aux = new_bb; | |
f008a564 | 775 | |
aa634f11 | 776 | if (new_bb->index >= array_size || last_basic_block > array_size) |
295ae817 | 777 | { |
aa634f11 JZ |
778 | int i; |
779 | int new_size; | |
780 | ||
781 | new_size = MAX (last_basic_block, new_bb->index + 1); | |
782 | new_size = GET_ARRAY_SIZE (new_size); | |
783 | bbd = xrealloc (bbd, new_size * sizeof (bbro_basic_block_data)); | |
784 | for (i = array_size; i < new_size; i++) | |
785 | { | |
786 | bbd[i].start_of_trace = -1; | |
87c8b4be | 787 | bbd[i].in_trace = -1; |
aa634f11 JZ |
788 | bbd[i].end_of_trace = -1; |
789 | bbd[i].heap = NULL; | |
790 | bbd[i].node = NULL; | |
791 | } | |
792 | array_size = new_size; | |
295ae817 | 793 | |
c263766c | 794 | if (dump_file) |
aa634f11 | 795 | { |
c263766c | 796 | fprintf (dump_file, |
aa634f11 JZ |
797 | "Growing the dynamic array to %d elements.\n", |
798 | array_size); | |
799 | } | |
295ae817 | 800 | } |
aa634f11 | 801 | |
87c8b4be CT |
802 | bbd[new_bb->index].in_trace = trace; |
803 | ||
aa634f11 JZ |
804 | return new_bb; |
805 | } | |
806 | ||
807 | /* Compute and return the key (for the heap) of the basic block BB. */ | |
808 | ||
809 | static fibheapkey_t | |
4682ae04 | 810 | bb_to_key (basic_block bb) |
aa634f11 JZ |
811 | { |
812 | edge e; | |
628f6a4e | 813 | edge_iterator ei; |
aa634f11 JZ |
814 | int priority = 0; |
815 | ||
816 | /* Do not start in probably never executed blocks. */ | |
750054a2 | 817 | |
076c7ab8 ZW |
818 | if (BB_PARTITION (bb) == BB_COLD_PARTITION |
819 | || probably_never_executed_bb_p (bb)) | |
aa634f11 JZ |
820 | return BB_FREQ_MAX; |
821 | ||
822 | /* Prefer blocks whose predecessor is an end of some trace | |
823 | or whose predecessor edge is EDGE_DFS_BACK. */ | |
628f6a4e | 824 | FOR_EACH_EDGE (e, ei, bb->preds) |
402209ff | 825 | { |
aa634f11 JZ |
826 | if ((e->src != ENTRY_BLOCK_PTR && bbd[e->src->index].end_of_trace >= 0) |
827 | || (e->flags & EDGE_DFS_BACK)) | |
828 | { | |
829 | int edge_freq = EDGE_FREQUENCY (e); | |
830 | ||
831 | if (edge_freq > priority) | |
832 | priority = edge_freq; | |
833 | } | |
402209ff | 834 | } |
295ae817 | 835 | |
aa634f11 JZ |
836 | if (priority) |
837 | /* The block with priority should have significantly lower key. */ | |
838 | return -(100 * BB_FREQ_MAX + 100 * priority + bb->frequency); | |
839 | return -bb->frequency; | |
840 | } | |
841 | ||
842 | /* Return true when the edge E from basic block BB is better than the temporary | |
843 | best edge (details are in function). The probability of edge E is PROB. The | |
844 | frequency of the successor is FREQ. The current best probability is | |
845 | BEST_PROB, the best frequency is BEST_FREQ. | |
846 | The edge is considered to be equivalent when PROB does not differ much from | |
847 | BEST_PROB; similarly for frequency. */ | |
848 | ||
849 | static bool | |
4682ae04 | 850 | better_edge_p (basic_block bb, edge e, int prob, int freq, int best_prob, |
750054a2 | 851 | int best_freq, edge cur_best_edge) |
aa634f11 JZ |
852 | { |
853 | bool is_better_edge; | |
f008a564 | 854 | |
aa634f11 JZ |
855 | /* The BEST_* values do not have to be best, but can be a bit smaller than |
856 | maximum values. */ | |
857 | int diff_prob = best_prob / 10; | |
858 | int diff_freq = best_freq / 10; | |
f008a564 | 859 | |
aa634f11 JZ |
860 | if (prob > best_prob + diff_prob) |
861 | /* The edge has higher probability than the temporary best edge. */ | |
862 | is_better_edge = true; | |
863 | else if (prob < best_prob - diff_prob) | |
864 | /* The edge has lower probability than the temporary best edge. */ | |
865 | is_better_edge = false; | |
866 | else if (freq < best_freq - diff_freq) | |
867 | /* The edge and the temporary best edge have almost equivalent | |
868 | probabilities. The higher frequency of a successor now means | |
869 | that there is another edge going into that successor. | |
870 | This successor has lower frequency so it is better. */ | |
871 | is_better_edge = true; | |
872 | else if (freq > best_freq + diff_freq) | |
873 | /* This successor has higher frequency so it is worse. */ | |
874 | is_better_edge = false; | |
875 | else if (e->dest->prev_bb == bb) | |
876 | /* The edges have equivalent probabilities and the successors | |
877 | have equivalent frequencies. Select the previous successor. */ | |
878 | is_better_edge = true; | |
879 | else | |
880 | is_better_edge = false; | |
881 | ||
750054a2 CT |
882 | /* If we are doing hot/cold partitioning, make sure that we always favor |
883 | non-crossing edges over crossing edges. */ | |
884 | ||
885 | if (!is_better_edge | |
c22cacf3 MS |
886 | && flag_reorder_blocks_and_partition |
887 | && cur_best_edge | |
bd454efd SB |
888 | && (cur_best_edge->flags & EDGE_CROSSING) |
889 | && !(e->flags & EDGE_CROSSING)) | |
750054a2 CT |
890 | is_better_edge = true; |
891 | ||
aa634f11 JZ |
892 | return is_better_edge; |
893 | } | |
894 | ||
895 | /* Connect traces in array TRACES, N_TRACES is the count of traces. */ | |
896 | ||
897 | static void | |
4682ae04 | 898 | connect_traces (int n_traces, struct trace *traces) |
aa634f11 JZ |
899 | { |
900 | int i; | |
901 | bool *connected; | |
87c8b4be | 902 | bool two_passes; |
aa634f11 | 903 | int last_trace; |
87c8b4be CT |
904 | int current_pass; |
905 | int current_partition; | |
aa634f11 JZ |
906 | int freq_threshold; |
907 | gcov_type count_threshold; | |
908 | ||
909 | freq_threshold = max_entry_frequency * DUPLICATION_THRESHOLD / 1000; | |
910 | if (max_entry_count < INT_MAX / 1000) | |
911 | count_threshold = max_entry_count * DUPLICATION_THRESHOLD / 1000; | |
912 | else | |
913 | count_threshold = max_entry_count / 1000 * DUPLICATION_THRESHOLD; | |
914 | ||
5ed6ace5 | 915 | connected = XCNEWVEC (bool, n_traces); |
aa634f11 | 916 | last_trace = -1; |
87c8b4be CT |
917 | current_pass = 1; |
918 | current_partition = BB_PARTITION (traces[0].first); | |
919 | two_passes = false; | |
750054a2 CT |
920 | |
921 | if (flag_reorder_blocks_and_partition) | |
87c8b4be | 922 | for (i = 0; i < n_traces && !two_passes; i++) |
c22cacf3 | 923 | if (BB_PARTITION (traces[0].first) |
87c8b4be CT |
924 | != BB_PARTITION (traces[i].first)) |
925 | two_passes = true; | |
926 | ||
927 | for (i = 0; i < n_traces || (two_passes && current_pass == 1) ; i++) | |
295ae817 | 928 | { |
aa634f11 JZ |
929 | int t = i; |
930 | int t2; | |
931 | edge e, best; | |
932 | int best_len; | |
295ae817 | 933 | |
87c8b4be | 934 | if (i >= n_traces) |
750054a2 | 935 | { |
41806d92 NS |
936 | gcc_assert (two_passes && current_pass == 1); |
937 | i = 0; | |
938 | t = i; | |
939 | current_pass = 2; | |
940 | if (current_partition == BB_HOT_PARTITION) | |
941 | current_partition = BB_COLD_PARTITION; | |
87c8b4be | 942 | else |
41806d92 | 943 | current_partition = BB_HOT_PARTITION; |
750054a2 | 944 | } |
c22cacf3 | 945 | |
aa634f11 JZ |
946 | if (connected[t]) |
947 | continue; | |
f008a564 | 948 | |
c22cacf3 | 949 | if (two_passes |
87c8b4be CT |
950 | && BB_PARTITION (traces[t].first) != current_partition) |
951 | continue; | |
952 | ||
aa634f11 | 953 | connected[t] = true; |
b0cc7919 | 954 | |
aa634f11 JZ |
955 | /* Find the predecessor traces. */ |
956 | for (t2 = t; t2 > 0;) | |
957 | { | |
628f6a4e | 958 | edge_iterator ei; |
aa634f11 JZ |
959 | best = NULL; |
960 | best_len = 0; | |
628f6a4e | 961 | FOR_EACH_EDGE (e, ei, traces[t2].first->preds) |
aa634f11 JZ |
962 | { |
963 | int si = e->src->index; | |
b0cc7919 | 964 | |
aa634f11 JZ |
965 | if (e->src != ENTRY_BLOCK_PTR |
966 | && (e->flags & EDGE_CAN_FALLTHRU) | |
967 | && !(e->flags & EDGE_COMPLEX) | |
968 | && bbd[si].end_of_trace >= 0 | |
969 | && !connected[bbd[si].end_of_trace] | |
87c8b4be | 970 | && (BB_PARTITION (e->src) == current_partition) |
aa634f11 JZ |
971 | && (!best |
972 | || e->probability > best->probability | |
973 | || (e->probability == best->probability | |
974 | && traces[bbd[si].end_of_trace].length > best_len))) | |
975 | { | |
976 | best = e; | |
977 | best_len = traces[bbd[si].end_of_trace].length; | |
978 | } | |
979 | } | |
980 | if (best) | |
981 | { | |
370369e1 | 982 | best->src->aux = best->dest; |
aa634f11 JZ |
983 | t2 = bbd[best->src->index].end_of_trace; |
984 | connected[t2] = true; | |
750054a2 | 985 | |
c263766c | 986 | if (dump_file) |
aa634f11 | 987 | { |
c263766c | 988 | fprintf (dump_file, "Connection: %d %d\n", |
aa634f11 JZ |
989 | best->src->index, best->dest->index); |
990 | } | |
991 | } | |
992 | else | |
993 | break; | |
994 | } | |
f008a564 | 995 | |
aa634f11 | 996 | if (last_trace >= 0) |
370369e1 | 997 | traces[last_trace].last->aux = traces[t2].first; |
aa634f11 JZ |
998 | last_trace = t; |
999 | ||
1000 | /* Find the successor traces. */ | |
1001 | while (1) | |
b0cc7919 | 1002 | { |
aa634f11 | 1003 | /* Find the continuation of the chain. */ |
628f6a4e | 1004 | edge_iterator ei; |
aa634f11 JZ |
1005 | best = NULL; |
1006 | best_len = 0; | |
628f6a4e | 1007 | FOR_EACH_EDGE (e, ei, traces[t].last->succs) |
aa634f11 JZ |
1008 | { |
1009 | int di = e->dest->index; | |
1010 | ||
1011 | if (e->dest != EXIT_BLOCK_PTR | |
1012 | && (e->flags & EDGE_CAN_FALLTHRU) | |
1013 | && !(e->flags & EDGE_COMPLEX) | |
1014 | && bbd[di].start_of_trace >= 0 | |
1015 | && !connected[bbd[di].start_of_trace] | |
87c8b4be | 1016 | && (BB_PARTITION (e->dest) == current_partition) |
aa634f11 JZ |
1017 | && (!best |
1018 | || e->probability > best->probability | |
1019 | || (e->probability == best->probability | |
1020 | && traces[bbd[di].start_of_trace].length > best_len))) | |
1021 | { | |
1022 | best = e; | |
1023 | best_len = traces[bbd[di].start_of_trace].length; | |
1024 | } | |
1025 | } | |
1026 | ||
1027 | if (best) | |
1028 | { | |
c263766c | 1029 | if (dump_file) |
aa634f11 | 1030 | { |
c263766c | 1031 | fprintf (dump_file, "Connection: %d %d\n", |
aa634f11 JZ |
1032 | best->src->index, best->dest->index); |
1033 | } | |
1034 | t = bbd[best->dest->index].start_of_trace; | |
370369e1 | 1035 | traces[last_trace].last->aux = traces[t].first; |
aa634f11 JZ |
1036 | connected[t] = true; |
1037 | last_trace = t; | |
1038 | } | |
1039 | else | |
1040 | { | |
1041 | /* Try to connect the traces by duplication of 1 block. */ | |
1042 | edge e2; | |
1043 | basic_block next_bb = NULL; | |
99dc7277 | 1044 | bool try_copy = false; |
aa634f11 | 1045 | |
628f6a4e | 1046 | FOR_EACH_EDGE (e, ei, traces[t].last->succs) |
aa634f11 JZ |
1047 | if (e->dest != EXIT_BLOCK_PTR |
1048 | && (e->flags & EDGE_CAN_FALLTHRU) | |
1049 | && !(e->flags & EDGE_COMPLEX) | |
99dc7277 | 1050 | && (!best || e->probability > best->probability)) |
aa634f11 | 1051 | { |
628f6a4e | 1052 | edge_iterator ei; |
aa634f11 JZ |
1053 | edge best2 = NULL; |
1054 | int best2_len = 0; | |
1055 | ||
6d9cc15b JZ |
1056 | /* If the destination is a start of a trace which is only |
1057 | one block long, then no need to search the successor | |
99dc7277 | 1058 | blocks of the trace. Accept it. */ |
6d9cc15b JZ |
1059 | if (bbd[e->dest->index].start_of_trace >= 0 |
1060 | && traces[bbd[e->dest->index].start_of_trace].length | |
1061 | == 1) | |
1062 | { | |
1063 | best = e; | |
1064 | try_copy = true; | |
1065 | continue; | |
1066 | } | |
99dc7277 | 1067 | |
628f6a4e | 1068 | FOR_EACH_EDGE (e2, ei, e->dest->succs) |
aa634f11 JZ |
1069 | { |
1070 | int di = e2->dest->index; | |
1071 | ||
1072 | if (e2->dest == EXIT_BLOCK_PTR | |
1073 | || ((e2->flags & EDGE_CAN_FALLTHRU) | |
1074 | && !(e2->flags & EDGE_COMPLEX) | |
1075 | && bbd[di].start_of_trace >= 0 | |
1076 | && !connected[bbd[di].start_of_trace] | |
87c8b4be | 1077 | && (BB_PARTITION (e2->dest) == current_partition) |
aa634f11 JZ |
1078 | && (EDGE_FREQUENCY (e2) >= freq_threshold) |
1079 | && (e2->count >= count_threshold) | |
1080 | && (!best2 | |
1081 | || e2->probability > best2->probability | |
1082 | || (e2->probability == best2->probability | |
1083 | && traces[bbd[di].start_of_trace].length | |
1084 | > best2_len)))) | |
1085 | { | |
1086 | best = e; | |
1087 | best2 = e2; | |
1088 | if (e2->dest != EXIT_BLOCK_PTR) | |
1089 | best2_len = traces[bbd[di].start_of_trace].length; | |
1090 | else | |
1091 | best2_len = INT_MAX; | |
1092 | next_bb = e2->dest; | |
99dc7277 | 1093 | try_copy = true; |
aa634f11 JZ |
1094 | } |
1095 | } | |
1096 | } | |
99dc7277 | 1097 | |
750054a2 CT |
1098 | if (flag_reorder_blocks_and_partition) |
1099 | try_copy = false; | |
1100 | ||
99dc7277 RH |
1101 | /* Copy tiny blocks always; copy larger blocks only when the |
1102 | edge is traversed frequently enough. */ | |
1103 | if (try_copy | |
1104 | && copy_bb_p (best->dest, | |
1105 | !optimize_size | |
1106 | && EDGE_FREQUENCY (best) >= freq_threshold | |
1107 | && best->count >= count_threshold)) | |
aa634f11 JZ |
1108 | { |
1109 | basic_block new_bb; | |
1110 | ||
c263766c | 1111 | if (dump_file) |
aa634f11 | 1112 | { |
c263766c | 1113 | fprintf (dump_file, "Connection: %d %d ", |
aa634f11 | 1114 | traces[t].last->index, best->dest->index); |
99dc7277 | 1115 | if (!next_bb) |
c263766c | 1116 | fputc ('\n', dump_file); |
99dc7277 | 1117 | else if (next_bb == EXIT_BLOCK_PTR) |
c263766c | 1118 | fprintf (dump_file, "exit\n"); |
aa634f11 | 1119 | else |
c263766c | 1120 | fprintf (dump_file, "%d\n", next_bb->index); |
aa634f11 JZ |
1121 | } |
1122 | ||
1123 | new_bb = copy_bb (best->dest, best, traces[t].last, t); | |
1124 | traces[t].last = new_bb; | |
99dc7277 | 1125 | if (next_bb && next_bb != EXIT_BLOCK_PTR) |
aa634f11 JZ |
1126 | { |
1127 | t = bbd[next_bb->index].start_of_trace; | |
370369e1 | 1128 | traces[last_trace].last->aux = traces[t].first; |
aa634f11 JZ |
1129 | connected[t] = true; |
1130 | last_trace = t; | |
1131 | } | |
1132 | else | |
1133 | break; /* Stop finding the successor traces. */ | |
1134 | } | |
1135 | else | |
1136 | break; /* Stop finding the successor traces. */ | |
1137 | } | |
b0cc7919 | 1138 | } |
aa634f11 JZ |
1139 | } |
1140 | ||
c263766c | 1141 | if (dump_file) |
aa634f11 JZ |
1142 | { |
1143 | basic_block bb; | |
f008a564 | 1144 | |
c263766c | 1145 | fprintf (dump_file, "Final order:\n"); |
370369e1 | 1146 | for (bb = traces[0].first; bb; bb = bb->aux) |
c263766c RH |
1147 | fprintf (dump_file, "%d ", bb->index); |
1148 | fprintf (dump_file, "\n"); | |
1149 | fflush (dump_file); | |
295ae817 JE |
1150 | } |
1151 | ||
aa634f11 JZ |
1152 | FREE (connected); |
1153 | } | |
1154 | ||
1155 | /* Return true when BB can and should be copied. CODE_MAY_GROW is true | |
1156 | when code size is allowed to grow by duplication. */ | |
1157 | ||
1158 | static bool | |
4682ae04 | 1159 | copy_bb_p (basic_block bb, int code_may_grow) |
aa634f11 JZ |
1160 | { |
1161 | int size = 0; | |
1162 | int max_size = uncond_jump_length; | |
1163 | rtx insn; | |
1164 | ||
1165 | if (!bb->frequency) | |
1166 | return false; | |
628f6a4e | 1167 | if (EDGE_COUNT (bb->preds) < 2) |
aa634f11 | 1168 | return false; |
6de9cd9a | 1169 | if (!can_duplicate_block_p (bb)) |
aa634f11 JZ |
1170 | return false; |
1171 | ||
6ae533cf | 1172 | /* Avoid duplicating blocks which have many successors (PR/13430). */ |
628f6a4e BE |
1173 | if (EDGE_COUNT (bb->succs) > 8) |
1174 | return false; | |
6ae533cf | 1175 | |
aa634f11 | 1176 | if (code_may_grow && maybe_hot_bb_p (bb)) |
f935b9e0 | 1177 | max_size *= PARAM_VALUE (PARAM_MAX_GROW_COPY_BB_INSNS); |
aa634f11 | 1178 | |
bbcb0c05 | 1179 | FOR_BB_INSNS (bb, insn) |
f008a564 | 1180 | { |
aa634f11 | 1181 | if (INSN_P (insn)) |
070a7956 | 1182 | size += get_attr_min_length (insn); |
f008a564 | 1183 | } |
295ae817 | 1184 | |
aa634f11 JZ |
1185 | if (size <= max_size) |
1186 | return true; | |
1187 | ||
c263766c | 1188 | if (dump_file) |
f008a564 | 1189 | { |
c263766c | 1190 | fprintf (dump_file, |
aa634f11 JZ |
1191 | "Block %d can't be copied because its size = %d.\n", |
1192 | bb->index, size); | |
f008a564 | 1193 | } |
295ae817 | 1194 | |
aa634f11 JZ |
1195 | return false; |
1196 | } | |
1197 | ||
1198 | /* Return the length of unconditional jump instruction. */ | |
1199 | ||
1200 | static int | |
4682ae04 | 1201 | get_uncond_jump_length (void) |
aa634f11 JZ |
1202 | { |
1203 | rtx label, jump; | |
1204 | int length; | |
1205 | ||
1206 | label = emit_label_before (gen_label_rtx (), get_insns ()); | |
1207 | jump = emit_jump_insn (gen_jump (label)); | |
1208 | ||
070a7956 | 1209 | length = get_attr_min_length (jump); |
aa634f11 JZ |
1210 | |
1211 | delete_insn (jump); | |
1212 | delete_insn (label); | |
1213 | return length; | |
295ae817 JE |
1214 | } |
1215 | ||
750054a2 CT |
1216 | /* Find the basic blocks that are rarely executed and need to be moved to |
1217 | a separate section of the .o file (to cut down on paging and improve | |
1218 | cache locality). */ | |
1219 | ||
1220 | static void | |
639d3040 | 1221 | find_rarely_executed_basic_blocks_and_crossing_edges (edge **crossing_edges, |
c22cacf3 | 1222 | int *n_crossing_edges, |
750054a2 CT |
1223 | int *max_idx) |
1224 | { | |
1225 | basic_block bb; | |
9fb32434 | 1226 | bool has_hot_blocks = false; |
750054a2 CT |
1227 | edge e; |
1228 | int i; | |
628f6a4e | 1229 | edge_iterator ei; |
750054a2 CT |
1230 | |
1231 | /* Mark which partition (hot/cold) each basic block belongs in. */ | |
c22cacf3 | 1232 | |
750054a2 CT |
1233 | FOR_EACH_BB (bb) |
1234 | { | |
1235 | if (probably_never_executed_bb_p (bb)) | |
076c7ab8 | 1236 | BB_SET_PARTITION (bb, BB_COLD_PARTITION); |
750054a2 | 1237 | else |
9fb32434 | 1238 | { |
076c7ab8 | 1239 | BB_SET_PARTITION (bb, BB_HOT_PARTITION); |
9fb32434 CT |
1240 | has_hot_blocks = true; |
1241 | } | |
750054a2 CT |
1242 | } |
1243 | ||
1244 | /* Mark every edge that crosses between sections. */ | |
1245 | ||
1246 | i = 0; | |
c7466dee CT |
1247 | FOR_EACH_BB (bb) |
1248 | FOR_EACH_EDGE (e, ei, bb->succs) | |
9fb32434 | 1249 | { |
c7466dee CT |
1250 | if (e->src != ENTRY_BLOCK_PTR |
1251 | && e->dest != EXIT_BLOCK_PTR | |
1252 | && BB_PARTITION (e->src) != BB_PARTITION (e->dest)) | |
1253 | { | |
1254 | e->flags |= EDGE_CROSSING; | |
1255 | if (i == *max_idx) | |
1256 | { | |
1257 | *max_idx *= 2; | |
639d3040 | 1258 | *crossing_edges = xrealloc (*crossing_edges, |
c7466dee CT |
1259 | (*max_idx) * sizeof (edge)); |
1260 | } | |
639d3040 | 1261 | (*crossing_edges)[i++] = e; |
c7466dee CT |
1262 | } |
1263 | else | |
1264 | e->flags &= ~EDGE_CROSSING; | |
9fb32434 | 1265 | } |
750054a2 CT |
1266 | *n_crossing_edges = i; |
1267 | } | |
1268 | ||
750054a2 CT |
1269 | /* If any destination of a crossing edge does not have a label, add label; |
1270 | Convert any fall-through crossing edges (for blocks that do not contain | |
9cf737f8 | 1271 | a jump) to unconditional jumps. */ |
750054a2 | 1272 | |
c22cacf3 | 1273 | static void |
750054a2 CT |
1274 | add_labels_and_missing_jumps (edge *crossing_edges, int n_crossing_edges) |
1275 | { | |
1276 | int i; | |
1277 | basic_block src; | |
1278 | basic_block dest; | |
1279 | rtx label; | |
1280 | rtx barrier; | |
1281 | rtx new_jump; | |
c22cacf3 MS |
1282 | |
1283 | for (i=0; i < n_crossing_edges; i++) | |
750054a2 | 1284 | { |
c22cacf3 MS |
1285 | if (crossing_edges[i]) |
1286 | { | |
1287 | src = crossing_edges[i]->src; | |
1288 | dest = crossing_edges[i]->dest; | |
1289 | ||
1290 | /* Make sure dest has a label. */ | |
1291 | ||
1292 | if (dest && (dest != EXIT_BLOCK_PTR)) | |
1293 | { | |
750054a2 | 1294 | label = block_label (dest); |
c22cacf3 MS |
1295 | |
1296 | /* Make sure source block ends with a jump. */ | |
1297 | ||
1298 | if (src && (src != ENTRY_BLOCK_PTR)) | |
1299 | { | |
4b4bf941 | 1300 | if (!JUMP_P (BB_END (src))) |
c22cacf3 MS |
1301 | /* bb just falls through. */ |
1302 | { | |
1303 | /* make sure there's only one successor */ | |
c5cbcccf | 1304 | gcc_assert (single_succ_p (src)); |
c22cacf3 | 1305 | |
298e6adc NS |
1306 | /* Find label in dest block. */ |
1307 | label = block_label (dest); | |
c22cacf3 MS |
1308 | |
1309 | new_jump = emit_jump_insn_after (gen_jump (label), | |
298e6adc NS |
1310 | BB_END (src)); |
1311 | barrier = emit_barrier_after (new_jump); | |
1312 | JUMP_LABEL (new_jump) = label; | |
1313 | LABEL_NUSES (label) += 1; | |
370369e1 | 1314 | src->il.rtl->footer = unlink_insn_chain (barrier, barrier); |
298e6adc NS |
1315 | /* Mark edge as non-fallthru. */ |
1316 | crossing_edges[i]->flags &= ~EDGE_FALLTHRU; | |
c22cacf3 MS |
1317 | } /* end: 'if (GET_CODE ... ' */ |
1318 | } /* end: 'if (src && src->index...' */ | |
1319 | } /* end: 'if (dest && dest->index...' */ | |
1320 | } /* end: 'if (crossing_edges[i]...' */ | |
750054a2 CT |
1321 | } /* end for loop */ |
1322 | } | |
1323 | ||
1324 | /* Find any bb's where the fall-through edge is a crossing edge (note that | |
1325 | these bb's must also contain a conditional jump; we've already | |
1326 | dealt with fall-through edges for blocks that didn't have a | |
1327 | conditional jump in the call to add_labels_and_missing_jumps). | |
1328 | Convert the fall-through edge to non-crossing edge by inserting a | |
1329 | new bb to fall-through into. The new bb will contain an | |
1330 | unconditional jump (crossing edge) to the original fall through | |
1331 | destination. */ | |
1332 | ||
c22cacf3 | 1333 | static void |
750054a2 CT |
1334 | fix_up_fall_thru_edges (void) |
1335 | { | |
1336 | basic_block cur_bb; | |
1337 | basic_block new_bb; | |
1338 | edge succ1; | |
1339 | edge succ2; | |
1340 | edge fall_thru; | |
4b493aa5 | 1341 | edge cond_jump = NULL; |
750054a2 CT |
1342 | edge e; |
1343 | bool cond_jump_crosses; | |
1344 | int invert_worked; | |
1345 | rtx old_jump; | |
1346 | rtx fall_thru_label; | |
1347 | rtx barrier; | |
c22cacf3 | 1348 | |
750054a2 CT |
1349 | FOR_EACH_BB (cur_bb) |
1350 | { | |
1351 | fall_thru = NULL; | |
628f6a4e BE |
1352 | if (EDGE_COUNT (cur_bb->succs) > 0) |
1353 | succ1 = EDGE_SUCC (cur_bb, 0); | |
1354 | else | |
1355 | succ1 = NULL; | |
1356 | ||
1357 | if (EDGE_COUNT (cur_bb->succs) > 1) | |
c22cacf3 | 1358 | succ2 = EDGE_SUCC (cur_bb, 1); |
750054a2 | 1359 | else |
c22cacf3 MS |
1360 | succ2 = NULL; |
1361 | ||
750054a2 | 1362 | /* Find the fall-through edge. */ |
c22cacf3 MS |
1363 | |
1364 | if (succ1 | |
1365 | && (succ1->flags & EDGE_FALLTHRU)) | |
1366 | { | |
1367 | fall_thru = succ1; | |
1368 | cond_jump = succ2; | |
1369 | } | |
1370 | else if (succ2 | |
1371 | && (succ2->flags & EDGE_FALLTHRU)) | |
1372 | { | |
1373 | fall_thru = succ2; | |
1374 | cond_jump = succ1; | |
1375 | } | |
1376 | ||
750054a2 | 1377 | if (fall_thru && (fall_thru->dest != EXIT_BLOCK_PTR)) |
c22cacf3 MS |
1378 | { |
1379 | /* Check to see if the fall-thru edge is a crossing edge. */ | |
1380 | ||
bd454efd | 1381 | if (fall_thru->flags & EDGE_CROSSING) |
c22cacf3 | 1382 | { |
750054a2 | 1383 | /* The fall_thru edge crosses; now check the cond jump edge, if |
c22cacf3 MS |
1384 | it exists. */ |
1385 | ||
1386 | cond_jump_crosses = true; | |
1387 | invert_worked = 0; | |
750054a2 | 1388 | old_jump = BB_END (cur_bb); |
c22cacf3 MS |
1389 | |
1390 | /* Find the jump instruction, if there is one. */ | |
1391 | ||
1392 | if (cond_jump) | |
1393 | { | |
bd454efd | 1394 | if (!(cond_jump->flags & EDGE_CROSSING)) |
c22cacf3 MS |
1395 | cond_jump_crosses = false; |
1396 | ||
1397 | /* We know the fall-thru edge crosses; if the cond | |
1398 | jump edge does NOT cross, and its destination is the | |
750054a2 | 1399 | next block in the bb order, invert the jump |
c22cacf3 MS |
1400 | (i.e. fix it so the fall thru does not cross and |
1401 | the cond jump does). */ | |
1402 | ||
750054a2 | 1403 | if (!cond_jump_crosses |
370369e1 | 1404 | && cur_bb->aux == cond_jump->dest) |
c22cacf3 MS |
1405 | { |
1406 | /* Find label in fall_thru block. We've already added | |
1407 | any missing labels, so there must be one. */ | |
1408 | ||
1409 | fall_thru_label = block_label (fall_thru->dest); | |
1410 | ||
1411 | if (old_jump && fall_thru_label) | |
1412 | invert_worked = invert_jump (old_jump, | |
1413 | fall_thru_label,0); | |
1414 | if (invert_worked) | |
1415 | { | |
1416 | fall_thru->flags &= ~EDGE_FALLTHRU; | |
1417 | cond_jump->flags |= EDGE_FALLTHRU; | |
1418 | update_br_prob_note (cur_bb); | |
1419 | e = fall_thru; | |
1420 | fall_thru = cond_jump; | |
1421 | cond_jump = e; | |
bd454efd SB |
1422 | cond_jump->flags |= EDGE_CROSSING; |
1423 | fall_thru->flags &= ~EDGE_CROSSING; | |
c22cacf3 MS |
1424 | } |
1425 | } | |
1426 | } | |
1427 | ||
1428 | if (cond_jump_crosses || !invert_worked) | |
1429 | { | |
1430 | /* This is the case where both edges out of the basic | |
1431 | block are crossing edges. Here we will fix up the | |
750054a2 CT |
1432 | fall through edge. The jump edge will be taken care |
1433 | of later. */ | |
c22cacf3 MS |
1434 | |
1435 | new_bb = force_nonfallthru (fall_thru); | |
1436 | ||
1437 | if (new_bb) | |
1438 | { | |
1439 | new_bb->aux = cur_bb->aux; | |
1440 | cur_bb->aux = new_bb; | |
1441 | ||
1442 | /* Make sure new fall-through bb is in same | |
750054a2 | 1443 | partition as bb it's falling through from. */ |
076c7ab8 ZW |
1444 | |
1445 | BB_COPY_PARTITION (new_bb, cur_bb); | |
c5cbcccf | 1446 | single_succ_edge (new_bb)->flags |= EDGE_CROSSING; |
c22cacf3 MS |
1447 | } |
1448 | ||
1449 | /* Add barrier after new jump */ | |
1450 | ||
1451 | if (new_bb) | |
1452 | { | |
1453 | barrier = emit_barrier_after (BB_END (new_bb)); | |
1454 | new_bb->il.rtl->footer = unlink_insn_chain (barrier, | |
1455 | barrier); | |
1456 | } | |
1457 | else | |
1458 | { | |
1459 | barrier = emit_barrier_after (BB_END (cur_bb)); | |
1460 | cur_bb->il.rtl->footer = unlink_insn_chain (barrier, | |
1461 | barrier); | |
1462 | } | |
1463 | } | |
1464 | } | |
1465 | } | |
750054a2 CT |
1466 | } |
1467 | } | |
1468 | ||
1469 | /* This function checks the destination blockof a "crossing jump" to | |
1470 | see if it has any crossing predecessors that begin with a code label | |
1471 | and end with an unconditional jump. If so, it returns that predecessor | |
1472 | block. (This is to avoid creating lots of new basic blocks that all | |
1473 | contain unconditional jumps to the same destination). */ | |
1474 | ||
1475 | static basic_block | |
c22cacf3 MS |
1476 | find_jump_block (basic_block jump_dest) |
1477 | { | |
1478 | basic_block source_bb = NULL; | |
750054a2 CT |
1479 | edge e; |
1480 | rtx insn; | |
628f6a4e | 1481 | edge_iterator ei; |
750054a2 | 1482 | |
628f6a4e | 1483 | FOR_EACH_EDGE (e, ei, jump_dest->preds) |
bd454efd | 1484 | if (e->flags & EDGE_CROSSING) |
750054a2 CT |
1485 | { |
1486 | basic_block src = e->src; | |
c22cacf3 | 1487 | |
750054a2 CT |
1488 | /* Check each predecessor to see if it has a label, and contains |
1489 | only one executable instruction, which is an unconditional jump. | |
9cf737f8 | 1490 | If so, we can use it. */ |
c22cacf3 | 1491 | |
4b4bf941 | 1492 | if (LABEL_P (BB_HEAD (src))) |
c22cacf3 | 1493 | for (insn = BB_HEAD (src); |
750054a2 CT |
1494 | !INSN_P (insn) && insn != NEXT_INSN (BB_END (src)); |
1495 | insn = NEXT_INSN (insn)) | |
1496 | { | |
1497 | if (INSN_P (insn) | |
1498 | && insn == BB_END (src) | |
4b4bf941 | 1499 | && JUMP_P (insn) |
750054a2 CT |
1500 | && !any_condjump_p (insn)) |
1501 | { | |
1502 | source_bb = src; | |
1503 | break; | |
1504 | } | |
1505 | } | |
c22cacf3 | 1506 | |
750054a2 CT |
1507 | if (source_bb) |
1508 | break; | |
1509 | } | |
1510 | ||
1511 | return source_bb; | |
1512 | } | |
1513 | ||
1514 | /* Find all BB's with conditional jumps that are crossing edges; | |
1515 | insert a new bb and make the conditional jump branch to the new | |
1516 | bb instead (make the new bb same color so conditional branch won't | |
1517 | be a 'crossing' edge). Insert an unconditional jump from the | |
1518 | new bb to the original destination of the conditional jump. */ | |
1519 | ||
1520 | static void | |
1521 | fix_crossing_conditional_branches (void) | |
1522 | { | |
1523 | basic_block cur_bb; | |
1524 | basic_block new_bb; | |
1525 | basic_block last_bb; | |
1526 | basic_block dest; | |
1527 | basic_block prev_bb; | |
1528 | edge succ1; | |
1529 | edge succ2; | |
1530 | edge crossing_edge; | |
1531 | edge new_edge; | |
1532 | rtx old_jump; | |
1533 | rtx set_src; | |
1534 | rtx old_label = NULL_RTX; | |
1535 | rtx new_label; | |
1536 | rtx new_jump; | |
1537 | rtx barrier; | |
1538 | ||
1539 | last_bb = EXIT_BLOCK_PTR->prev_bb; | |
c22cacf3 | 1540 | |
750054a2 CT |
1541 | FOR_EACH_BB (cur_bb) |
1542 | { | |
1543 | crossing_edge = NULL; | |
628f6a4e BE |
1544 | if (EDGE_COUNT (cur_bb->succs) > 0) |
1545 | succ1 = EDGE_SUCC (cur_bb, 0); | |
1546 | else | |
1547 | succ1 = NULL; | |
c22cacf3 | 1548 | |
628f6a4e BE |
1549 | if (EDGE_COUNT (cur_bb->succs) > 1) |
1550 | succ2 = EDGE_SUCC (cur_bb, 1); | |
750054a2 | 1551 | else |
628f6a4e | 1552 | succ2 = NULL; |
c22cacf3 | 1553 | |
750054a2 CT |
1554 | /* We already took care of fall-through edges, so only one successor |
1555 | can be a crossing edge. */ | |
c22cacf3 | 1556 | |
bd454efd | 1557 | if (succ1 && (succ1->flags & EDGE_CROSSING)) |
750054a2 | 1558 | crossing_edge = succ1; |
bd454efd | 1559 | else if (succ2 && (succ2->flags & EDGE_CROSSING)) |
c22cacf3 MS |
1560 | crossing_edge = succ2; |
1561 | ||
1562 | if (crossing_edge) | |
1563 | { | |
750054a2 | 1564 | old_jump = BB_END (cur_bb); |
c22cacf3 | 1565 | |
750054a2 CT |
1566 | /* Check to make sure the jump instruction is a |
1567 | conditional jump. */ | |
c22cacf3 | 1568 | |
750054a2 CT |
1569 | set_src = NULL_RTX; |
1570 | ||
1571 | if (any_condjump_p (old_jump)) | |
1572 | { | |
1573 | if (GET_CODE (PATTERN (old_jump)) == SET) | |
1574 | set_src = SET_SRC (PATTERN (old_jump)); | |
1575 | else if (GET_CODE (PATTERN (old_jump)) == PARALLEL) | |
1576 | { | |
1577 | set_src = XVECEXP (PATTERN (old_jump), 0,0); | |
1578 | if (GET_CODE (set_src) == SET) | |
1579 | set_src = SET_SRC (set_src); | |
1580 | else | |
1581 | set_src = NULL_RTX; | |
1582 | } | |
1583 | } | |
1584 | ||
1585 | if (set_src && (GET_CODE (set_src) == IF_THEN_ELSE)) | |
1586 | { | |
1587 | if (GET_CODE (XEXP (set_src, 1)) == PC) | |
1588 | old_label = XEXP (set_src, 2); | |
1589 | else if (GET_CODE (XEXP (set_src, 2)) == PC) | |
1590 | old_label = XEXP (set_src, 1); | |
c22cacf3 | 1591 | |
750054a2 CT |
1592 | /* Check to see if new bb for jumping to that dest has |
1593 | already been created; if so, use it; if not, create | |
1594 | a new one. */ | |
1595 | ||
1596 | new_bb = find_jump_block (crossing_edge->dest); | |
c22cacf3 | 1597 | |
750054a2 CT |
1598 | if (new_bb) |
1599 | new_label = block_label (new_bb); | |
1600 | else | |
1601 | { | |
1602 | /* Create new basic block to be dest for | |
1603 | conditional jump. */ | |
c22cacf3 | 1604 | |
750054a2 | 1605 | new_bb = create_basic_block (NULL, NULL, last_bb); |
370369e1 JH |
1606 | new_bb->aux = last_bb->aux; |
1607 | last_bb->aux = new_bb; | |
750054a2 CT |
1608 | prev_bb = last_bb; |
1609 | last_bb = new_bb; | |
750054a2 | 1610 | /* Put appropriate instructions in new bb. */ |
c22cacf3 | 1611 | |
750054a2 CT |
1612 | new_label = gen_label_rtx (); |
1613 | emit_label_before (new_label, BB_HEAD (new_bb)); | |
1614 | BB_HEAD (new_bb) = new_label; | |
c22cacf3 | 1615 | |
750054a2 CT |
1616 | if (GET_CODE (old_label) == LABEL_REF) |
1617 | { | |
1618 | old_label = JUMP_LABEL (old_jump); | |
c22cacf3 MS |
1619 | new_jump = emit_jump_insn_after (gen_jump |
1620 | (old_label), | |
750054a2 CT |
1621 | BB_END (new_bb)); |
1622 | } | |
750054a2 | 1623 | else |
298e6adc NS |
1624 | { |
1625 | gcc_assert (HAVE_return | |
1626 | && GET_CODE (old_label) == RETURN); | |
c22cacf3 | 1627 | new_jump = emit_jump_insn_after (gen_return (), |
298e6adc NS |
1628 | BB_END (new_bb)); |
1629 | } | |
c22cacf3 | 1630 | |
750054a2 CT |
1631 | barrier = emit_barrier_after (new_jump); |
1632 | JUMP_LABEL (new_jump) = old_label; | |
c22cacf3 | 1633 | new_bb->il.rtl->footer = unlink_insn_chain (barrier, |
750054a2 | 1634 | barrier); |
c22cacf3 | 1635 | |
750054a2 CT |
1636 | /* Make sure new bb is in same partition as source |
1637 | of conditional branch. */ | |
076c7ab8 | 1638 | BB_COPY_PARTITION (new_bb, cur_bb); |
750054a2 | 1639 | } |
c22cacf3 | 1640 | |
750054a2 | 1641 | /* Make old jump branch to new bb. */ |
c22cacf3 | 1642 | |
750054a2 | 1643 | redirect_jump (old_jump, new_label, 0); |
c22cacf3 | 1644 | |
750054a2 | 1645 | /* Remove crossing_edge as predecessor of 'dest'. */ |
c22cacf3 | 1646 | |
750054a2 | 1647 | dest = crossing_edge->dest; |
c22cacf3 | 1648 | |
750054a2 | 1649 | redirect_edge_succ (crossing_edge, new_bb); |
c22cacf3 | 1650 | |
750054a2 CT |
1651 | /* Make a new edge from new_bb to old dest; new edge |
1652 | will be a successor for new_bb and a predecessor | |
1653 | for 'dest'. */ | |
c22cacf3 | 1654 | |
628f6a4e | 1655 | if (EDGE_COUNT (new_bb->succs) == 0) |
750054a2 CT |
1656 | new_edge = make_edge (new_bb, dest, 0); |
1657 | else | |
628f6a4e | 1658 | new_edge = EDGE_SUCC (new_bb, 0); |
c22cacf3 | 1659 | |
bd454efd SB |
1660 | crossing_edge->flags &= ~EDGE_CROSSING; |
1661 | new_edge->flags |= EDGE_CROSSING; | |
750054a2 | 1662 | } |
c22cacf3 | 1663 | } |
750054a2 CT |
1664 | } |
1665 | } | |
1666 | ||
1667 | /* Find any unconditional branches that cross between hot and cold | |
1668 | sections. Convert them into indirect jumps instead. */ | |
1669 | ||
1670 | static void | |
1671 | fix_crossing_unconditional_branches (void) | |
1672 | { | |
1673 | basic_block cur_bb; | |
1674 | rtx last_insn; | |
1675 | rtx label; | |
1676 | rtx label_addr; | |
1677 | rtx indirect_jump_sequence; | |
1678 | rtx jump_insn = NULL_RTX; | |
1679 | rtx new_reg; | |
1680 | rtx cur_insn; | |
1681 | edge succ; | |
9fb32434 | 1682 | |
750054a2 CT |
1683 | FOR_EACH_BB (cur_bb) |
1684 | { | |
1685 | last_insn = BB_END (cur_bb); | |
87c8b4be CT |
1686 | |
1687 | if (EDGE_COUNT (cur_bb->succs) < 1) | |
1688 | continue; | |
1689 | ||
628f6a4e | 1690 | succ = EDGE_SUCC (cur_bb, 0); |
750054a2 CT |
1691 | |
1692 | /* Check to see if bb ends in a crossing (unconditional) jump. At | |
c22cacf3 | 1693 | this point, no crossing jumps should be conditional. */ |
750054a2 | 1694 | |
4b4bf941 | 1695 | if (JUMP_P (last_insn) |
bd454efd | 1696 | && (succ->flags & EDGE_CROSSING)) |
750054a2 CT |
1697 | { |
1698 | rtx label2, table; | |
1699 | ||
298e6adc | 1700 | gcc_assert (!any_condjump_p (last_insn)); |
750054a2 CT |
1701 | |
1702 | /* Make sure the jump is not already an indirect or table jump. */ | |
1703 | ||
298e6adc NS |
1704 | if (!computed_jump_p (last_insn) |
1705 | && !tablejump_p (last_insn, &label2, &table)) | |
750054a2 CT |
1706 | { |
1707 | /* We have found a "crossing" unconditional branch. Now | |
1708 | we must convert it to an indirect jump. First create | |
1709 | reference of label, as target for jump. */ | |
c22cacf3 | 1710 | |
750054a2 | 1711 | label = JUMP_LABEL (last_insn); |
b50b729d | 1712 | label_addr = gen_rtx_LABEL_REF (Pmode, label); |
750054a2 | 1713 | LABEL_NUSES (label) += 1; |
c22cacf3 | 1714 | |
750054a2 | 1715 | /* Get a register to use for the indirect jump. */ |
c22cacf3 | 1716 | |
750054a2 | 1717 | new_reg = gen_reg_rtx (Pmode); |
c22cacf3 | 1718 | |
750054a2 | 1719 | /* Generate indirect the jump sequence. */ |
c22cacf3 | 1720 | |
750054a2 CT |
1721 | start_sequence (); |
1722 | emit_move_insn (new_reg, label_addr); | |
1723 | emit_indirect_jump (new_reg); | |
1724 | indirect_jump_sequence = get_insns (); | |
1725 | end_sequence (); | |
c22cacf3 | 1726 | |
750054a2 CT |
1727 | /* Make sure every instruction in the new jump sequence has |
1728 | its basic block set to be cur_bb. */ | |
c22cacf3 | 1729 | |
750054a2 CT |
1730 | for (cur_insn = indirect_jump_sequence; cur_insn; |
1731 | cur_insn = NEXT_INSN (cur_insn)) | |
1732 | { | |
0e714a54 EB |
1733 | if (!BARRIER_P (cur_insn)) |
1734 | BLOCK_FOR_INSN (cur_insn) = cur_bb; | |
4b4bf941 | 1735 | if (JUMP_P (cur_insn)) |
750054a2 CT |
1736 | jump_insn = cur_insn; |
1737 | } | |
c22cacf3 | 1738 | |
750054a2 CT |
1739 | /* Insert the new (indirect) jump sequence immediately before |
1740 | the unconditional jump, then delete the unconditional jump. */ | |
c22cacf3 | 1741 | |
750054a2 CT |
1742 | emit_insn_before (indirect_jump_sequence, last_insn); |
1743 | delete_insn (last_insn); | |
c22cacf3 | 1744 | |
750054a2 CT |
1745 | /* Make BB_END for cur_bb be the jump instruction (NOT the |
1746 | barrier instruction at the end of the sequence...). */ | |
c22cacf3 | 1747 | |
750054a2 CT |
1748 | BB_END (cur_bb) = jump_insn; |
1749 | } | |
1750 | } | |
1751 | } | |
1752 | } | |
1753 | ||
1754 | /* Add REG_CROSSING_JUMP note to all crossing jump insns. */ | |
1755 | ||
1756 | static void | |
1757 | add_reg_crossing_jump_notes (void) | |
1758 | { | |
1759 | basic_block bb; | |
1760 | edge e; | |
628f6a4e | 1761 | edge_iterator ei; |
750054a2 CT |
1762 | |
1763 | FOR_EACH_BB (bb) | |
628f6a4e | 1764 | FOR_EACH_EDGE (e, ei, bb->succs) |
bd454efd | 1765 | if ((e->flags & EDGE_CROSSING) |
4b4bf941 | 1766 | && JUMP_P (BB_END (e->src))) |
c22cacf3 MS |
1767 | REG_NOTES (BB_END (e->src)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP, |
1768 | NULL_RTX, | |
1769 | REG_NOTES (BB_END | |
750054a2 CT |
1770 | (e->src))); |
1771 | } | |
1772 | ||
830113fd | 1773 | /* Hot and cold basic blocks are partitioned and put in separate |
87c8b4be CT |
1774 | sections of the .o file, to reduce paging and improve cache |
1775 | performance (hopefully). This can result in bits of code from the | |
1776 | same function being widely separated in the .o file. However this | |
1777 | is not obvious to the current bb structure. Therefore we must take | |
1778 | care to ensure that: 1). There are no fall_thru edges that cross | |
1779 | between sections; 2). For those architectures which have "short" | |
1780 | conditional branches, all conditional branches that attempt to | |
1781 | cross between sections are converted to unconditional branches; | |
1782 | and, 3). For those architectures which have "short" unconditional | |
1783 | branches, all unconditional branches that attempt to cross between | |
1784 | sections are converted to indirect jumps. | |
1785 | ||
750054a2 | 1786 | The code for fixing up fall_thru edges that cross between hot and |
c22cacf3 MS |
1787 | cold basic blocks does so by creating new basic blocks containing |
1788 | unconditional branches to the appropriate label in the "other" | |
750054a2 CT |
1789 | section. The new basic block is then put in the same (hot or cold) |
1790 | section as the original conditional branch, and the fall_thru edge | |
1791 | is modified to fall into the new basic block instead. By adding | |
1792 | this level of indirection we end up with only unconditional branches | |
c22cacf3 MS |
1793 | crossing between hot and cold sections. |
1794 | ||
750054a2 | 1795 | Conditional branches are dealt with by adding a level of indirection. |
c22cacf3 | 1796 | A new basic block is added in the same (hot/cold) section as the |
750054a2 CT |
1797 | conditional branch, and the conditional branch is retargeted to the |
1798 | new basic block. The new basic block contains an unconditional branch | |
1799 | to the original target of the conditional branch (in the other section). | |
1800 | ||
1801 | Unconditional branches are dealt with by converting them into | |
1802 | indirect jumps. */ | |
1803 | ||
c22cacf3 MS |
1804 | static void |
1805 | fix_edges_for_rarely_executed_code (edge *crossing_edges, | |
750054a2 CT |
1806 | int n_crossing_edges) |
1807 | { | |
1808 | /* Make sure the source of any crossing edge ends in a jump and the | |
1809 | destination of any crossing edge has a label. */ | |
c22cacf3 | 1810 | |
750054a2 | 1811 | add_labels_and_missing_jumps (crossing_edges, n_crossing_edges); |
c22cacf3 | 1812 | |
750054a2 CT |
1813 | /* Convert all crossing fall_thru edges to non-crossing fall |
1814 | thrus to unconditional jumps (that jump to the original fall | |
1815 | thru dest). */ | |
c22cacf3 | 1816 | |
750054a2 | 1817 | fix_up_fall_thru_edges (); |
c22cacf3 | 1818 | |
c7466dee CT |
1819 | /* If the architecture does not have conditional branches that can |
1820 | span all of memory, convert crossing conditional branches into | |
1821 | crossing unconditional branches. */ | |
c22cacf3 | 1822 | |
c7466dee CT |
1823 | if (!HAS_LONG_COND_BRANCH) |
1824 | fix_crossing_conditional_branches (); | |
c22cacf3 | 1825 | |
c7466dee CT |
1826 | /* If the architecture does not have unconditional branches that |
1827 | can span all of memory, convert crossing unconditional branches | |
1828 | into indirect jumps. Since adding an indirect jump also adds | |
1829 | a new register usage, update the register usage information as | |
1830 | well. */ | |
c22cacf3 | 1831 | |
c7466dee | 1832 | if (!HAS_LONG_UNCOND_BRANCH) |
6fb5fa3c | 1833 | fix_crossing_unconditional_branches (); |
c22cacf3 | 1834 | |
c7466dee | 1835 | add_reg_crossing_jump_notes (); |
750054a2 CT |
1836 | } |
1837 | ||
87c8b4be CT |
1838 | /* Verify, in the basic block chain, that there is at most one switch |
1839 | between hot/cold partitions. This is modelled on | |
1840 | rtl_verify_flow_info_1, but it cannot go inside that function | |
1841 | because this condition will not be true until after | |
1842 | reorder_basic_blocks is called. */ | |
1843 | ||
1844 | static void | |
1845 | verify_hot_cold_block_grouping (void) | |
1846 | { | |
1847 | basic_block bb; | |
1848 | int err = 0; | |
1849 | bool switched_sections = false; | |
1850 | int current_partition = 0; | |
c22cacf3 | 1851 | |
87c8b4be CT |
1852 | FOR_EACH_BB (bb) |
1853 | { | |
1854 | if (!current_partition) | |
1855 | current_partition = BB_PARTITION (bb); | |
1856 | if (BB_PARTITION (bb) != current_partition) | |
1857 | { | |
1858 | if (switched_sections) | |
1859 | { | |
ab532386 | 1860 | error ("multiple hot/cold transitions found (bb %i)", |
87c8b4be CT |
1861 | bb->index); |
1862 | err = 1; | |
1863 | } | |
1864 | else | |
1865 | { | |
1866 | switched_sections = true; | |
1867 | current_partition = BB_PARTITION (bb); | |
1868 | } | |
1869 | } | |
1870 | } | |
c22cacf3 | 1871 | |
1ad435a5 | 1872 | gcc_assert(!err); |
87c8b4be CT |
1873 | } |
1874 | ||
35b6b437 RS |
1875 | /* Reorder basic blocks. The main entry point to this file. FLAGS is |
1876 | the set of flags to pass to cfg_layout_initialize(). */ | |
295ae817 JE |
1877 | |
1878 | void | |
ad21dab7 | 1879 | reorder_basic_blocks (void) |
295ae817 | 1880 | { |
aa634f11 JZ |
1881 | int n_traces; |
1882 | int i; | |
1883 | struct trace *traces; | |
1884 | ||
ad21dab7 | 1885 | gcc_assert (current_ir_type () == IR_RTL_CFGLAYOUT); |
295ae817 | 1886 | |
ad21dab7 | 1887 | if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) |
e4ec2cac AO |
1888 | return; |
1889 | ||
aa634f11 JZ |
1890 | set_edge_can_fallthru_flag (); |
1891 | mark_dfs_back_edges (); | |
1892 | ||
e0bb17a8 KH |
1893 | /* We are estimating the length of uncond jump insn only once since the code |
1894 | for getting the insn length always returns the minimal length now. */ | |
4682ae04 | 1895 | if (uncond_jump_length == 0) |
aa634f11 JZ |
1896 | uncond_jump_length = get_uncond_jump_length (); |
1897 | ||
1898 | /* We need to know some information for each basic block. */ | |
1899 | array_size = GET_ARRAY_SIZE (last_basic_block); | |
5ed6ace5 | 1900 | bbd = XNEWVEC (bbro_basic_block_data, array_size); |
aa634f11 JZ |
1901 | for (i = 0; i < array_size; i++) |
1902 | { | |
1903 | bbd[i].start_of_trace = -1; | |
87c8b4be | 1904 | bbd[i].in_trace = -1; |
aa634f11 JZ |
1905 | bbd[i].end_of_trace = -1; |
1906 | bbd[i].heap = NULL; | |
1907 | bbd[i].node = NULL; | |
1908 | } | |
1909 | ||
5ed6ace5 | 1910 | traces = XNEWVEC (struct trace, n_basic_blocks); |
aa634f11 JZ |
1911 | n_traces = 0; |
1912 | find_traces (&n_traces, traces); | |
1913 | connect_traces (n_traces, traces); | |
1914 | FREE (traces); | |
1915 | FREE (bbd); | |
402209ff | 1916 | |
ad21dab7 SB |
1917 | relink_block_chain (/*stay_in_cfglayout_mode=*/true); |
1918 | ||
c263766c | 1919 | if (dump_file) |
5b4fdb20 | 1920 | dump_flow_info (dump_file, dump_flags); |
402209ff | 1921 | |
c7466dee CT |
1922 | if (flag_reorder_blocks_and_partition) |
1923 | verify_hot_cold_block_grouping (); | |
295ae817 | 1924 | } |
bbcb0c05 | 1925 | |
87c8b4be CT |
1926 | /* Determine which partition the first basic block in the function |
1927 | belongs to, then find the first basic block in the current function | |
1928 | that belongs to a different section, and insert a | |
1929 | NOTE_INSN_SWITCH_TEXT_SECTIONS note immediately before it in the | |
1930 | instruction stream. When writing out the assembly code, | |
1931 | encountering this note will make the compiler switch between the | |
1932 | hot and cold text sections. */ | |
1933 | ||
43f237b4 | 1934 | static void |
87c8b4be CT |
1935 | insert_section_boundary_note (void) |
1936 | { | |
1937 | basic_block bb; | |
1938 | rtx new_note; | |
1939 | int first_partition = 0; | |
c22cacf3 | 1940 | |
c7466dee | 1941 | if (flag_reorder_blocks_and_partition) |
87c8b4be CT |
1942 | FOR_EACH_BB (bb) |
1943 | { | |
1944 | if (!first_partition) | |
1945 | first_partition = BB_PARTITION (bb); | |
1946 | if (BB_PARTITION (bb) != first_partition) | |
1947 | { | |
1948 | new_note = emit_note_before (NOTE_INSN_SWITCH_TEXT_SECTIONS, | |
1949 | BB_HEAD (bb)); | |
1950 | break; | |
1951 | } | |
1952 | } | |
1953 | } | |
1954 | ||
bbcb0c05 SB |
1955 | /* Duplicate the blocks containing computed gotos. This basically unfactors |
1956 | computed gotos that were factored early on in the compilation process to | |
1957 | speed up edge based data flow. We used to not unfactoring them again, | |
1958 | which can seriously pessimize code with many computed jumps in the source | |
1959 | code, such as interpreters. See e.g. PR15242. */ | |
1960 | ||
ef330312 PB |
1961 | static bool |
1962 | gate_duplicate_computed_gotos (void) | |
1963 | { | |
ad21dab7 SB |
1964 | if (targetm.cannot_modify_jumps_p ()) |
1965 | return false; | |
ef330312 PB |
1966 | return (optimize > 0 && flag_expensive_optimizations && !optimize_size); |
1967 | } | |
1968 | ||
1969 | ||
c2924966 | 1970 | static unsigned int |
bbcb0c05 SB |
1971 | duplicate_computed_gotos (void) |
1972 | { | |
1973 | basic_block bb, new_bb; | |
1974 | bitmap candidates; | |
1975 | int max_size; | |
1976 | ||
24bd1a0b | 1977 | if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) |
c2924966 | 1978 | return 0; |
bbcb0c05 | 1979 | |
bbcb0c05 SB |
1980 | cfg_layout_initialize (0); |
1981 | ||
1982 | /* We are estimating the length of uncond jump insn only once | |
1983 | since the code for getting the insn length always returns | |
1984 | the minimal length now. */ | |
1985 | if (uncond_jump_length == 0) | |
1986 | uncond_jump_length = get_uncond_jump_length (); | |
1987 | ||
1988 | max_size = uncond_jump_length * PARAM_VALUE (PARAM_MAX_GOTO_DUPLICATION_INSNS); | |
8bdbfff5 | 1989 | candidates = BITMAP_ALLOC (NULL); |
bbcb0c05 | 1990 | |
00b28cb0 SB |
1991 | /* Look for blocks that end in a computed jump, and see if such blocks |
1992 | are suitable for unfactoring. If a block is a candidate for unfactoring, | |
1993 | mark it in the candidates. */ | |
bbcb0c05 SB |
1994 | FOR_EACH_BB (bb) |
1995 | { | |
00b28cb0 SB |
1996 | rtx insn; |
1997 | edge e; | |
1998 | edge_iterator ei; | |
1999 | int size, all_flags; | |
2000 | ||
2001 | /* Build the reorder chain for the original order of blocks. */ | |
bbcb0c05 | 2002 | if (bb->next_bb != EXIT_BLOCK_PTR) |
370369e1 | 2003 | bb->aux = bb->next_bb; |
bbcb0c05 | 2004 | |
00b28cb0 SB |
2005 | /* Obviously the block has to end in a computed jump. */ |
2006 | if (!computed_jump_p (BB_END (bb))) | |
2007 | continue; | |
bbcb0c05 | 2008 | |
00b28cb0 SB |
2009 | /* Only consider blocks that can be duplicated. */ |
2010 | if (find_reg_note (BB_END (bb), REG_CROSSING_JUMP, NULL_RTX) | |
2011 | || !can_duplicate_block_p (bb)) | |
2012 | continue; | |
bbcb0c05 | 2013 | |
00b28cb0 SB |
2014 | /* Make sure that the block is small enough. */ |
2015 | size = 0; | |
2016 | FOR_BB_INSNS (bb, insn) | |
2017 | if (INSN_P (insn)) | |
2018 | { | |
070a7956 | 2019 | size += get_attr_min_length (insn); |
00b28cb0 SB |
2020 | if (size > max_size) |
2021 | break; | |
2022 | } | |
2023 | if (size > max_size) | |
2024 | continue; | |
2025 | ||
2026 | /* Final check: there must not be any incoming abnormal edges. */ | |
2027 | all_flags = 0; | |
2028 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2029 | all_flags |= e->flags; | |
2030 | if (all_flags & EDGE_COMPLEX) | |
2031 | continue; | |
2032 | ||
2033 | bitmap_set_bit (candidates, bb->index); | |
bbcb0c05 SB |
2034 | } |
2035 | ||
2036 | /* Nothing to do if there is no computed jump here. */ | |
2037 | if (bitmap_empty_p (candidates)) | |
2038 | goto done; | |
2039 | ||
2040 | /* Duplicate computed gotos. */ | |
2041 | FOR_EACH_BB (bb) | |
2042 | { | |
370369e1 | 2043 | if (bb->il.rtl->visited) |
bbcb0c05 SB |
2044 | continue; |
2045 | ||
370369e1 | 2046 | bb->il.rtl->visited = 1; |
bbcb0c05 SB |
2047 | |
2048 | /* BB must have one outgoing edge. That edge must not lead to | |
c22cacf3 | 2049 | the exit block or the next block. |
bbcb0c05 | 2050 | The destination must have more than one predecessor. */ |
c5cbcccf ZD |
2051 | if (!single_succ_p (bb) |
2052 | || single_succ (bb) == EXIT_BLOCK_PTR | |
2053 | || single_succ (bb) == bb->next_bb | |
2054 | || single_pred_p (single_succ (bb))) | |
bbcb0c05 SB |
2055 | continue; |
2056 | ||
2057 | /* The successor block has to be a duplication candidate. */ | |
c5cbcccf | 2058 | if (!bitmap_bit_p (candidates, single_succ (bb)->index)) |
bbcb0c05 SB |
2059 | continue; |
2060 | ||
b9a66240 | 2061 | new_bb = duplicate_block (single_succ (bb), single_succ_edge (bb), bb); |
370369e1 JH |
2062 | new_bb->aux = bb->aux; |
2063 | bb->aux = new_bb; | |
2064 | new_bb->il.rtl->visited = 1; | |
bbcb0c05 SB |
2065 | } |
2066 | ||
2067 | done: | |
2068 | cfg_layout_finalize (); | |
2069 | ||
8bdbfff5 | 2070 | BITMAP_FREE (candidates); |
c2924966 | 2071 | return 0; |
bbcb0c05 | 2072 | } |
750054a2 | 2073 | |
ef330312 PB |
2074 | struct tree_opt_pass pass_duplicate_computed_gotos = |
2075 | { | |
defb77dc | 2076 | "compgotos", /* name */ |
ef330312 PB |
2077 | gate_duplicate_computed_gotos, /* gate */ |
2078 | duplicate_computed_gotos, /* execute */ | |
2079 | NULL, /* sub */ | |
2080 | NULL, /* next */ | |
2081 | 0, /* static_pass_number */ | |
2082 | TV_REORDER_BLOCKS, /* tv_id */ | |
2083 | 0, /* properties_required */ | |
2084 | 0, /* properties_provided */ | |
2085 | 0, /* properties_destroyed */ | |
2086 | 0, /* todo_flags_start */ | |
defb77dc | 2087 | TODO_dump_func, /* todo_flags_finish */ |
ef330312 PB |
2088 | 0 /* letter */ |
2089 | }; | |
2090 | ||
2091 | ||
750054a2 CT |
2092 | /* This function is the main 'entrance' for the optimization that |
2093 | partitions hot and cold basic blocks into separate sections of the | |
2094 | .o file (to improve performance and cache locality). Ideally it | |
2095 | would be called after all optimizations that rearrange the CFG have | |
2096 | been called. However part of this optimization may introduce new | |
2097 | register usage, so it must be called before register allocation has | |
2098 | occurred. This means that this optimization is actually called | |
8e8d5162 CT |
2099 | well before the optimization that reorders basic blocks (see |
2100 | function above). | |
750054a2 CT |
2101 | |
2102 | This optimization checks the feedback information to determine | |
87c8b4be CT |
2103 | which basic blocks are hot/cold, updates flags on the basic blocks |
2104 | to indicate which section they belong in. This information is | |
2105 | later used for writing out sections in the .o file. Because hot | |
2106 | and cold sections can be arbitrarily large (within the bounds of | |
2107 | memory), far beyond the size of a single function, it is necessary | |
2108 | to fix up all edges that cross section boundaries, to make sure the | |
2109 | instructions used can actually span the required distance. The | |
2110 | fixes are described below. | |
8e8d5162 CT |
2111 | |
2112 | Fall-through edges must be changed into jumps; it is not safe or | |
2113 | legal to fall through across a section boundary. Whenever a | |
2114 | fall-through edge crossing a section boundary is encountered, a new | |
2115 | basic block is inserted (in the same section as the fall-through | |
2116 | source), and the fall through edge is redirected to the new basic | |
2117 | block. The new basic block contains an unconditional jump to the | |
2118 | original fall-through target. (If the unconditional jump is | |
2119 | insufficient to cross section boundaries, that is dealt with a | |
2120 | little later, see below). | |
2121 | ||
2122 | In order to deal with architectures that have short conditional | |
2123 | branches (which cannot span all of memory) we take any conditional | |
2124 | jump that attempts to cross a section boundary and add a level of | |
2125 | indirection: it becomes a conditional jump to a new basic block, in | |
2126 | the same section. The new basic block contains an unconditional | |
2127 | jump to the original target, in the other section. | |
2128 | ||
2129 | For those architectures whose unconditional branch is also | |
2130 | incapable of reaching all of memory, those unconditional jumps are | |
2131 | converted into indirect jumps, through a register. | |
2132 | ||
2133 | IMPORTANT NOTE: This optimization causes some messy interactions | |
2134 | with the cfg cleanup optimizations; those optimizations want to | |
2135 | merge blocks wherever possible, and to collapse indirect jump | |
2136 | sequences (change "A jumps to B jumps to C" directly into "A jumps | |
2137 | to C"). Those optimizations can undo the jump fixes that | |
2138 | partitioning is required to make (see above), in order to ensure | |
2139 | that jumps attempting to cross section boundaries are really able | |
2140 | to cover whatever distance the jump requires (on many architectures | |
2141 | conditional or unconditional jumps are not able to reach all of | |
2142 | memory). Therefore tests have to be inserted into each such | |
2143 | optimization to make sure that it does not undo stuff necessary to | |
2144 | cross partition boundaries. This would be much less of a problem | |
2145 | if we could perform this optimization later in the compilation, but | |
2146 | unfortunately the fact that we may need to create indirect jumps | |
2147 | (through registers) requires that this optimization be performed | |
2148 | before register allocation. */ | |
750054a2 | 2149 | |
081c6ba6 | 2150 | static void |
750054a2 CT |
2151 | partition_hot_cold_basic_blocks (void) |
2152 | { | |
2153 | basic_block cur_bb; | |
2154 | edge *crossing_edges; | |
2155 | int n_crossing_edges; | |
2156 | int max_edges = 2 * last_basic_block; | |
c22cacf3 | 2157 | |
24bd1a0b | 2158 | if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) |
750054a2 | 2159 | return; |
c22cacf3 | 2160 | |
5ed6ace5 | 2161 | crossing_edges = XCNEWVEC (edge, max_edges); |
750054a2 | 2162 | |
35b6b437 | 2163 | cfg_layout_initialize (0); |
c22cacf3 | 2164 | |
750054a2 | 2165 | FOR_EACH_BB (cur_bb) |
24bd1a0b | 2166 | if (cur_bb->index >= NUM_FIXED_BLOCKS |
c22cacf3 | 2167 | && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS) |
370369e1 | 2168 | cur_bb->aux = cur_bb->next_bb; |
c22cacf3 | 2169 | |
639d3040 | 2170 | find_rarely_executed_basic_blocks_and_crossing_edges (&crossing_edges, |
c22cacf3 | 2171 | &n_crossing_edges, |
750054a2 CT |
2172 | &max_edges); |
2173 | ||
2174 | if (n_crossing_edges > 0) | |
2175 | fix_edges_for_rarely_executed_code (crossing_edges, n_crossing_edges); | |
c22cacf3 | 2176 | |
750054a2 CT |
2177 | free (crossing_edges); |
2178 | ||
62e5bf5d | 2179 | cfg_layout_finalize (); |
750054a2 | 2180 | } |
ef330312 PB |
2181 | \f |
2182 | static bool | |
2183 | gate_handle_reorder_blocks (void) | |
2184 | { | |
ad21dab7 SB |
2185 | if (targetm.cannot_modify_jumps_p ()) |
2186 | return false; | |
ef330312 PB |
2187 | return (optimize > 0); |
2188 | } | |
2189 | ||
2190 | ||
2191 | /* Reorder basic blocks. */ | |
c2924966 | 2192 | static unsigned int |
ef330312 PB |
2193 | rest_of_handle_reorder_blocks (void) |
2194 | { | |
ad21dab7 | 2195 | basic_block bb; |
ef330312 PB |
2196 | |
2197 | /* Last attempt to optimize CFG, as scheduling, peepholing and insn | |
2198 | splitting possibly introduced more crossjumping opportunities. */ | |
6fb5fa3c | 2199 | cfg_layout_initialize (CLEANUP_EXPENSIVE); |
ef330312 PB |
2200 | |
2201 | if (flag_sched2_use_traces && flag_schedule_insns_after_reload) | |
2202 | { | |
2203 | timevar_push (TV_TRACER); | |
ad21dab7 | 2204 | tracer (); |
ef330312 PB |
2205 | timevar_pop (TV_TRACER); |
2206 | } | |
2207 | ||
2208 | if (flag_reorder_blocks || flag_reorder_blocks_and_partition) | |
ad21dab7 | 2209 | reorder_basic_blocks (); |
ef330312 PB |
2210 | if (flag_reorder_blocks || flag_reorder_blocks_and_partition |
2211 | || (flag_sched2_use_traces && flag_schedule_insns_after_reload)) | |
6fb5fa3c | 2212 | cleanup_cfg (CLEANUP_EXPENSIVE); |
43f237b4 | 2213 | |
ad21dab7 SB |
2214 | FOR_EACH_BB (bb) |
2215 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
2216 | bb->aux = bb->next_bb; | |
2217 | cfg_layout_finalize (); | |
2218 | ||
43f237b4 EB |
2219 | /* Add NOTE_INSN_SWITCH_TEXT_SECTIONS notes. */ |
2220 | insert_section_boundary_note (); | |
c2924966 | 2221 | return 0; |
ef330312 PB |
2222 | } |
2223 | ||
2224 | struct tree_opt_pass pass_reorder_blocks = | |
2225 | { | |
2226 | "bbro", /* name */ | |
2227 | gate_handle_reorder_blocks, /* gate */ | |
2228 | rest_of_handle_reorder_blocks, /* execute */ | |
2229 | NULL, /* sub */ | |
2230 | NULL, /* next */ | |
2231 | 0, /* static_pass_number */ | |
2232 | TV_REORDER_BLOCKS, /* tv_id */ | |
2233 | 0, /* properties_required */ | |
2234 | 0, /* properties_provided */ | |
2235 | 0, /* properties_destroyed */ | |
2236 | 0, /* todo_flags_start */ | |
2237 | TODO_dump_func, /* todo_flags_finish */ | |
2238 | 'B' /* letter */ | |
2239 | }; | |
2240 | ||
2241 | static bool | |
2242 | gate_handle_partition_blocks (void) | |
2243 | { | |
2244 | /* The optimization to partition hot/cold basic blocks into separate | |
2245 | sections of the .o file does not work well with linkonce or with | |
2246 | user defined section attributes. Don't call it if either case | |
2247 | arises. */ | |
2248 | ||
2249 | return (flag_reorder_blocks_and_partition | |
c22cacf3 MS |
2250 | && !DECL_ONE_ONLY (current_function_decl) |
2251 | && !user_defined_section_attribute); | |
ef330312 PB |
2252 | } |
2253 | ||
2254 | /* Partition hot and cold basic blocks. */ | |
c2924966 | 2255 | static unsigned int |
ef330312 PB |
2256 | rest_of_handle_partition_blocks (void) |
2257 | { | |
ef330312 | 2258 | partition_hot_cold_basic_blocks (); |
c2924966 | 2259 | return 0; |
ef330312 PB |
2260 | } |
2261 | ||
2262 | struct tree_opt_pass pass_partition_blocks = | |
2263 | { | |
defb77dc | 2264 | "bbpart", /* name */ |
ef330312 PB |
2265 | gate_handle_partition_blocks, /* gate */ |
2266 | rest_of_handle_partition_blocks, /* execute */ | |
2267 | NULL, /* sub */ | |
2268 | NULL, /* next */ | |
2269 | 0, /* static_pass_number */ | |
2270 | TV_REORDER_BLOCKS, /* tv_id */ | |
2271 | 0, /* properties_required */ | |
2272 | 0, /* properties_provided */ | |
2273 | 0, /* properties_destroyed */ | |
2274 | 0, /* todo_flags_start */ | |
defb77dc | 2275 | TODO_dump_func, /* todo_flags_finish */ |
ef330312 PB |
2276 | 0 /* letter */ |
2277 | }; | |
2278 | ||
2279 |