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295ae817 | 1 | /* Basic block reordering routines for the GNU compiler. |
818ab71a | 2 | Copyright (C) 2000-2016 Free Software Foundation, Inc. |
295ae817 | 3 | |
1322177d | 4 | This file is part of GCC. |
295ae817 | 5 | |
1322177d LB |
6 | GCC is free software; you can redistribute it and/or modify it |
7 | under the terms of the GNU General Public License as published by | |
9dcd6f09 | 8 | the Free Software Foundation; either version 3, or (at your option) |
295ae817 JE |
9 | any later version. |
10 | ||
1322177d LB |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
13 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
14 | License for more details. | |
295ae817 JE |
15 | |
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
295ae817 | 19 | |
248c16c4 SB |
20 | /* This file contains the "reorder blocks" pass, which changes the control |
21 | flow of a function to encounter fewer branches; the "partition blocks" | |
22 | pass, which divides the basic blocks into "hot" and "cold" partitions, | |
23 | which are kept separate; and the "duplicate computed gotos" pass, which | |
24 | duplicates blocks ending in an indirect jump. | |
25 | ||
26 | There are two algorithms for "reorder blocks": the "simple" algorithm, | |
27 | which just rearranges blocks, trying to minimize the number of executed | |
28 | unconditional branches; and the "software trace cache" algorithm, which | |
29 | also copies code, and in general tries a lot harder to have long linear | |
30 | pieces of machine code executed. This algorithm is described next. */ | |
31 | ||
aa634f11 JZ |
32 | /* This (greedy) algorithm constructs traces in several rounds. |
33 | The construction starts from "seeds". The seed for the first round | |
4700dd70 EB |
34 | is the entry point of the function. When there are more than one seed, |
35 | the one with the lowest key in the heap is selected first (see bb_to_key). | |
36 | Then the algorithm repeatedly adds the most probable successor to the end | |
37 | of a trace. Finally it connects the traces. | |
aa634f11 JZ |
38 | |
39 | There are two parameters: Branch Threshold and Exec Threshold. | |
4700dd70 EB |
40 | If the probability of an edge to a successor of the current basic block is |
41 | lower than Branch Threshold or its frequency is lower than Exec Threshold, | |
42 | then the successor will be the seed in one of the next rounds. | |
aa634f11 | 43 | Each round has these parameters lower than the previous one. |
4700dd70 EB |
44 | The last round has to have these parameters set to zero so that the |
45 | remaining blocks are picked up. | |
aa634f11 JZ |
46 | |
47 | The algorithm selects the most probable successor from all unvisited | |
48 | successors and successors that have been added to this trace. | |
49 | The other successors (that has not been "sent" to the next round) will be | |
4700dd70 EB |
50 | other seeds for this round and the secondary traces will start from them. |
51 | If the successor has not been visited in this trace, it is added to the | |
52 | trace (however, there is some heuristic for simple branches). | |
53 | If the successor has been visited in this trace, a loop has been found. | |
54 | If the loop has many iterations, the loop is rotated so that the source | |
55 | block of the most probable edge going out of the loop is the last block | |
56 | of the trace. | |
aa634f11 | 57 | If the loop has few iterations and there is no edge from the last block of |
4700dd70 | 58 | the loop going out of the loop, the loop header is duplicated. |
aa634f11 | 59 | |
4700dd70 EB |
60 | When connecting traces, the algorithm first checks whether there is an edge |
61 | from the last block of a trace to the first block of another trace. | |
aa634f11 | 62 | When there are still some unconnected traces it checks whether there exists |
4700dd70 EB |
63 | a basic block BB such that BB is a successor of the last block of a trace |
64 | and BB is a predecessor of the first block of another trace. In this case, | |
65 | BB is duplicated, added at the end of the first trace and the traces are | |
66 | connected through it. | |
aa634f11 | 67 | The rest of traces are simply connected so there will be a jump to the |
4700dd70 | 68 | beginning of the rest of traces. |
aa634f11 | 69 | |
f7d0c571 ZC |
70 | The above description is for the full algorithm, which is used when the |
71 | function is optimized for speed. When the function is optimized for size, | |
72 | in order to reduce long jumps and connect more fallthru edges, the | |
73 | algorithm is modified as follows: | |
74 | (1) Break long traces to short ones. A trace is broken at a block that has | |
75 | multiple predecessors/ successors during trace discovery. When connecting | |
76 | traces, only connect Trace n with Trace n + 1. This change reduces most | |
77 | long jumps compared with the above algorithm. | |
78 | (2) Ignore the edge probability and frequency for fallthru edges. | |
79 | (3) Keep the original order of blocks when there is no chance to fall | |
80 | through. We rely on the results of cfg_cleanup. | |
81 | ||
82 | To implement the change for code size optimization, block's index is | |
83 | selected as the key and all traces are found in one round. | |
aa634f11 JZ |
84 | |
85 | References: | |
86 | ||
87 | "Software Trace Cache" | |
88 | A. Ramirez, J. Larriba-Pey, C. Navarro, J. Torrellas and M. Valero; 1999 | |
89 | http://citeseer.nj.nec.com/15361.html | |
90 | ||
295ae817 JE |
91 | */ |
92 | ||
93 | #include "config.h" | |
01736018 | 94 | #define INCLUDE_ALGORITHM /* stable_sort */ |
295ae817 | 95 | #include "system.h" |
4977bab6 | 96 | #include "coretypes.h" |
c7131fb2 | 97 | #include "backend.h" |
957060b5 | 98 | #include "target.h" |
295ae817 | 99 | #include "rtl.h" |
957060b5 AM |
100 | #include "tree.h" |
101 | #include "cfghooks.h" | |
c7131fb2 | 102 | #include "df.h" |
957060b5 | 103 | #include "optabs.h" |
7932a3db | 104 | #include "regs.h" |
957060b5 | 105 | #include "emit-rtl.h" |
295ae817 | 106 | #include "output.h" |
750054a2 | 107 | #include "expr.h" |
bbcb0c05 | 108 | #include "params.h" |
718f9c0f | 109 | #include "toplev.h" /* user_defined_section_attribute */ |
ef330312 | 110 | #include "tree-pass.h" |
60393bbc AM |
111 | #include "cfgrtl.h" |
112 | #include "cfganal.h" | |
113 | #include "cfgbuild.h" | |
114 | #include "cfgcleanup.h" | |
76ee381a | 115 | #include "bb-reorder.h" |
0be7e7a6 | 116 | #include "except.h" |
8d261514 | 117 | #include "fibonacci_heap.h" |
ef330312 | 118 | |
750054a2 CT |
119 | /* The number of rounds. In most cases there will only be 4 rounds, but |
120 | when partitioning hot and cold basic blocks into separate sections of | |
4700dd70 | 121 | the object file there will be an extra round. */ |
750054a2 | 122 | #define N_ROUNDS 5 |
aa634f11 | 123 | |
76ee381a RS |
124 | struct target_bb_reorder default_target_bb_reorder; |
125 | #if SWITCHABLE_TARGET | |
126 | struct target_bb_reorder *this_target_bb_reorder = &default_target_bb_reorder; | |
127 | #endif | |
128 | ||
129 | #define uncond_jump_length \ | |
130 | (this_target_bb_reorder->x_uncond_jump_length) | |
131 | ||
aa634f11 | 132 | /* Branch thresholds in thousandths (per mille) of the REG_BR_PROB_BASE. */ |
cfb00b41 | 133 | static const int branch_threshold[N_ROUNDS] = {400, 200, 100, 0, 0}; |
aa634f11 JZ |
134 | |
135 | /* Exec thresholds in thousandths (per mille) of the frequency of bb 0. */ | |
cfb00b41 | 136 | static const int exec_threshold[N_ROUNDS] = {500, 200, 50, 0, 0}; |
aa634f11 JZ |
137 | |
138 | /* If edge frequency is lower than DUPLICATION_THRESHOLD per mille of entry | |
139 | block the edge destination is not duplicated while connecting traces. */ | |
140 | #define DUPLICATION_THRESHOLD 100 | |
141 | ||
8d261514 ML |
142 | typedef fibonacci_heap <long, basic_block_def> bb_heap_t; |
143 | typedef fibonacci_node <long, basic_block_def> bb_heap_node_t; | |
144 | ||
aa634f11 | 145 | /* Structure to hold needed information for each basic block. */ |
a79683d5 | 146 | struct bbro_basic_block_data |
aa634f11 | 147 | { |
4700dd70 | 148 | /* Which trace is the bb start of (-1 means it is not a start of any). */ |
aa634f11 JZ |
149 | int start_of_trace; |
150 | ||
4700dd70 | 151 | /* Which trace is the bb end of (-1 means it is not an end of any). */ |
aa634f11 JZ |
152 | int end_of_trace; |
153 | ||
87c8b4be CT |
154 | /* Which trace is the bb in? */ |
155 | int in_trace; | |
156 | ||
bcc708fc MM |
157 | /* Which trace was this bb visited in? */ |
158 | int visited; | |
159 | ||
aa634f11 | 160 | /* Which heap is BB in (if any)? */ |
8d261514 | 161 | bb_heap_t *heap; |
aa634f11 JZ |
162 | |
163 | /* Which heap node is BB in (if any)? */ | |
8d261514 | 164 | bb_heap_node_t *node; |
a79683d5 | 165 | }; |
aa634f11 JZ |
166 | |
167 | /* The current size of the following dynamic array. */ | |
168 | static int array_size; | |
169 | ||
170 | /* The array which holds needed information for basic blocks. */ | |
171 | static bbro_basic_block_data *bbd; | |
172 | ||
173 | /* To avoid frequent reallocation the size of arrays is greater than needed, | |
174 | the number of elements is (not less than) 1.25 * size_wanted. */ | |
175 | #define GET_ARRAY_SIZE(X) ((((X) / 4) + 1) * 5) | |
176 | ||
177 | /* Free the memory and set the pointer to NULL. */ | |
298e6adc | 178 | #define FREE(P) (gcc_assert (P), free (P), P = 0) |
aa634f11 JZ |
179 | |
180 | /* Structure for holding information about a trace. */ | |
181 | struct trace | |
182 | { | |
183 | /* First and last basic block of the trace. */ | |
184 | basic_block first, last; | |
185 | ||
186 | /* The round of the STC creation which this trace was found in. */ | |
187 | int round; | |
188 | ||
189 | /* The length (i.e. the number of basic blocks) of the trace. */ | |
190 | int length; | |
191 | }; | |
192 | ||
193 | /* Maximum frequency and count of one of the entry blocks. */ | |
cd735ab8 KH |
194 | static int max_entry_frequency; |
195 | static gcov_type max_entry_count; | |
aa634f11 | 196 | |
295ae817 | 197 | /* Local function prototypes. */ |
4682ae04 AJ |
198 | static void find_traces (int *, struct trace *); |
199 | static basic_block rotate_loop (edge, struct trace *, int); | |
200 | static void mark_bb_visited (basic_block, int); | |
201 | static void find_traces_1_round (int, int, gcov_type, struct trace *, int *, | |
8d261514 | 202 | int, bb_heap_t **, int); |
4682ae04 | 203 | static basic_block copy_bb (basic_block, edge, basic_block, int); |
8d261514 | 204 | static long bb_to_key (basic_block); |
4700dd70 EB |
205 | static bool better_edge_p (const_basic_block, const_edge, int, int, int, int, |
206 | const_edge); | |
f7d0c571 ZC |
207 | static bool connect_better_edge_p (const_edge, bool, int, const_edge, |
208 | struct trace *); | |
4682ae04 | 209 | static void connect_traces (int, struct trace *); |
9678086d | 210 | static bool copy_bb_p (const_basic_block, int); |
ed7a4b4b | 211 | static bool push_to_next_round_p (const_basic_block, int, int, int, gcov_type); |
f008a564 | 212 | \f |
bcc708fc MM |
213 | /* Return the trace number in which BB was visited. */ |
214 | ||
215 | static int | |
216 | bb_visited_trace (const_basic_block bb) | |
217 | { | |
218 | gcc_assert (bb->index < array_size); | |
219 | return bbd[bb->index].visited; | |
220 | } | |
221 | ||
222 | /* This function marks BB that it was visited in trace number TRACE. */ | |
223 | ||
224 | static void | |
225 | mark_bb_visited (basic_block bb, int trace) | |
226 | { | |
227 | bbd[bb->index].visited = trace; | |
228 | if (bbd[bb->index].heap) | |
229 | { | |
8d261514 | 230 | bbd[bb->index].heap->delete_node (bbd[bb->index].node); |
bcc708fc MM |
231 | bbd[bb->index].heap = NULL; |
232 | bbd[bb->index].node = NULL; | |
233 | } | |
234 | } | |
235 | ||
750054a2 CT |
236 | /* Check to see if bb should be pushed into the next round of trace |
237 | collections or not. Reasons for pushing the block forward are 1). | |
238 | If the block is cold, we are doing partitioning, and there will be | |
239 | another round (cold partition blocks are not supposed to be | |
240 | collected into traces until the very last round); or 2). There will | |
241 | be another round, and the basic block is not "hot enough" for the | |
242 | current round of trace collection. */ | |
243 | ||
244 | static bool | |
ed7a4b4b | 245 | push_to_next_round_p (const_basic_block bb, int round, int number_of_rounds, |
750054a2 CT |
246 | int exec_th, gcov_type count_th) |
247 | { | |
248 | bool there_exists_another_round; | |
750054a2 CT |
249 | bool block_not_hot_enough; |
250 | ||
251 | there_exists_another_round = round < number_of_rounds - 1; | |
750054a2 | 252 | |
c22cacf3 | 253 | block_not_hot_enough = (bb->frequency < exec_th |
750054a2 | 254 | || bb->count < count_th |
2eb712b4 | 255 | || probably_never_executed_bb_p (cfun, bb)); |
750054a2 | 256 | |
87c8b4be CT |
257 | if (there_exists_another_round |
258 | && block_not_hot_enough) | |
750054a2 | 259 | return true; |
c22cacf3 | 260 | else |
750054a2 CT |
261 | return false; |
262 | } | |
263 | ||
aa634f11 JZ |
264 | /* Find the traces for Software Trace Cache. Chain each trace through |
265 | RBI()->next. Store the number of traces to N_TRACES and description of | |
266 | traces to TRACES. */ | |
295ae817 | 267 | |
f008a564 | 268 | static void |
4682ae04 | 269 | find_traces (int *n_traces, struct trace *traces) |
295ae817 | 270 | { |
aa634f11 | 271 | int i; |
750054a2 | 272 | int number_of_rounds; |
aa634f11 | 273 | edge e; |
628f6a4e | 274 | edge_iterator ei; |
8d261514 | 275 | bb_heap_t *heap = new bb_heap_t (LONG_MIN); |
aa634f11 | 276 | |
750054a2 CT |
277 | /* Add one extra round of trace collection when partitioning hot/cold |
278 | basic blocks into separate sections. The last round is for all the | |
279 | cold blocks (and ONLY the cold blocks). */ | |
280 | ||
281 | number_of_rounds = N_ROUNDS - 1; | |
750054a2 | 282 | |
aa634f11 | 283 | /* Insert entry points of function into heap. */ |
aa634f11 JZ |
284 | max_entry_frequency = 0; |
285 | max_entry_count = 0; | |
fefa31b5 | 286 | FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs) |
aa634f11 JZ |
287 | { |
288 | bbd[e->dest->index].heap = heap; | |
8d261514 | 289 | bbd[e->dest->index].node = heap->insert (bb_to_key (e->dest), e->dest); |
aa634f11 JZ |
290 | if (e->dest->frequency > max_entry_frequency) |
291 | max_entry_frequency = e->dest->frequency; | |
292 | if (e->dest->count > max_entry_count) | |
293 | max_entry_count = e->dest->count; | |
294 | } | |
295 | ||
296 | /* Find the traces. */ | |
750054a2 | 297 | for (i = 0; i < number_of_rounds; i++) |
aa634f11 JZ |
298 | { |
299 | gcov_type count_threshold; | |
f008a564 | 300 | |
c263766c RH |
301 | if (dump_file) |
302 | fprintf (dump_file, "STC - round %d\n", i + 1); | |
aa634f11 JZ |
303 | |
304 | if (max_entry_count < INT_MAX / 1000) | |
305 | count_threshold = max_entry_count * exec_threshold[i] / 1000; | |
306 | else | |
307 | count_threshold = max_entry_count / 1000 * exec_threshold[i]; | |
308 | ||
309 | find_traces_1_round (REG_BR_PROB_BASE * branch_threshold[i] / 1000, | |
310 | max_entry_frequency * exec_threshold[i] / 1000, | |
750054a2 CT |
311 | count_threshold, traces, n_traces, i, &heap, |
312 | number_of_rounds); | |
aa634f11 | 313 | } |
8d261514 | 314 | delete heap; |
aa634f11 | 315 | |
c263766c | 316 | if (dump_file) |
aa634f11 JZ |
317 | { |
318 | for (i = 0; i < *n_traces; i++) | |
319 | { | |
320 | basic_block bb; | |
c263766c | 321 | fprintf (dump_file, "Trace %d (round %d): ", i + 1, |
aa634f11 | 322 | traces[i].round + 1); |
4700dd70 EB |
323 | for (bb = traces[i].first; |
324 | bb != traces[i].last; | |
325 | bb = (basic_block) bb->aux) | |
c263766c RH |
326 | fprintf (dump_file, "%d [%d] ", bb->index, bb->frequency); |
327 | fprintf (dump_file, "%d [%d]\n", bb->index, bb->frequency); | |
aa634f11 | 328 | } |
c263766c | 329 | fflush (dump_file); |
aa634f11 JZ |
330 | } |
331 | } | |
332 | ||
333 | /* Rotate loop whose back edge is BACK_EDGE in the tail of trace TRACE | |
334 | (with sequential number TRACE_N). */ | |
335 | ||
336 | static basic_block | |
4682ae04 | 337 | rotate_loop (edge back_edge, struct trace *trace, int trace_n) |
aa634f11 JZ |
338 | { |
339 | basic_block bb; | |
340 | ||
341 | /* Information about the best end (end after rotation) of the loop. */ | |
342 | basic_block best_bb = NULL; | |
343 | edge best_edge = NULL; | |
344 | int best_freq = -1; | |
345 | gcov_type best_count = -1; | |
346 | /* The best edge is preferred when its destination is not visited yet | |
347 | or is a start block of some trace. */ | |
348 | bool is_preferred = false; | |
349 | ||
350 | /* Find the most frequent edge that goes out from current trace. */ | |
351 | bb = back_edge->dest; | |
f008a564 RH |
352 | do |
353 | { | |
aa634f11 | 354 | edge e; |
628f6a4e BE |
355 | edge_iterator ei; |
356 | ||
357 | FOR_EACH_EDGE (e, ei, bb->succs) | |
fefa31b5 | 358 | if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
bcc708fc | 359 | && bb_visited_trace (e->dest) != trace_n |
aa634f11 JZ |
360 | && (e->flags & EDGE_CAN_FALLTHRU) |
361 | && !(e->flags & EDGE_COMPLEX)) | |
362 | { | |
363 | if (is_preferred) | |
364 | { | |
365 | /* The best edge is preferred. */ | |
bcc708fc | 366 | if (!bb_visited_trace (e->dest) |
aa634f11 JZ |
367 | || bbd[e->dest->index].start_of_trace >= 0) |
368 | { | |
369 | /* The current edge E is also preferred. */ | |
370 | int freq = EDGE_FREQUENCY (e); | |
371 | if (freq > best_freq || e->count > best_count) | |
372 | { | |
373 | best_freq = freq; | |
374 | best_count = e->count; | |
375 | best_edge = e; | |
376 | best_bb = bb; | |
377 | } | |
378 | } | |
379 | } | |
380 | else | |
381 | { | |
bcc708fc | 382 | if (!bb_visited_trace (e->dest) |
aa634f11 JZ |
383 | || bbd[e->dest->index].start_of_trace >= 0) |
384 | { | |
385 | /* The current edge E is preferred. */ | |
386 | is_preferred = true; | |
387 | best_freq = EDGE_FREQUENCY (e); | |
388 | best_count = e->count; | |
389 | best_edge = e; | |
390 | best_bb = bb; | |
391 | } | |
392 | else | |
393 | { | |
394 | int freq = EDGE_FREQUENCY (e); | |
395 | if (!best_edge || freq > best_freq || e->count > best_count) | |
396 | { | |
397 | best_freq = freq; | |
398 | best_count = e->count; | |
399 | best_edge = e; | |
400 | best_bb = bb; | |
401 | } | |
402 | } | |
403 | } | |
404 | } | |
f883e0a7 | 405 | bb = (basic_block) bb->aux; |
aa634f11 JZ |
406 | } |
407 | while (bb != back_edge->dest); | |
408 | ||
409 | if (best_bb) | |
410 | { | |
411 | /* Rotate the loop so that the BEST_EDGE goes out from the last block of | |
412 | the trace. */ | |
413 | if (back_edge->dest == trace->first) | |
414 | { | |
f883e0a7 | 415 | trace->first = (basic_block) best_bb->aux; |
aa634f11 JZ |
416 | } |
417 | else | |
418 | { | |
419 | basic_block prev_bb; | |
ca7fd9cd | 420 | |
aa634f11 | 421 | for (prev_bb = trace->first; |
370369e1 | 422 | prev_bb->aux != back_edge->dest; |
f883e0a7 | 423 | prev_bb = (basic_block) prev_bb->aux) |
aa634f11 | 424 | ; |
370369e1 | 425 | prev_bb->aux = best_bb->aux; |
aa634f11 JZ |
426 | |
427 | /* Try to get rid of uncond jump to cond jump. */ | |
c5cbcccf | 428 | if (single_succ_p (prev_bb)) |
aa634f11 | 429 | { |
c5cbcccf | 430 | basic_block header = single_succ (prev_bb); |
aa634f11 JZ |
431 | |
432 | /* Duplicate HEADER if it is a small block containing cond jump | |
433 | in the end. */ | |
9fb32434 | 434 | if (any_condjump_p (BB_END (header)) && copy_bb_p (header, 0) |
339ba33b | 435 | && !CROSSING_JUMP_P (BB_END (header))) |
c5cbcccf | 436 | copy_bb (header, single_succ_edge (prev_bb), prev_bb, trace_n); |
aa634f11 JZ |
437 | } |
438 | } | |
439 | } | |
440 | else | |
441 | { | |
442 | /* We have not found suitable loop tail so do no rotation. */ | |
443 | best_bb = back_edge->src; | |
295ae817 | 444 | } |
370369e1 | 445 | best_bb->aux = NULL; |
aa634f11 | 446 | return best_bb; |
f008a564 | 447 | } |
295ae817 | 448 | |
4700dd70 EB |
449 | /* One round of finding traces. Find traces for BRANCH_TH and EXEC_TH i.e. do |
450 | not include basic blocks whose probability is lower than BRANCH_TH or whose | |
451 | frequency is lower than EXEC_TH into traces (or whose count is lower than | |
452 | COUNT_TH). Store the new traces into TRACES and modify the number of | |
453 | traces *N_TRACES. Set the round (which the trace belongs to) to ROUND. | |
454 | The function expects starting basic blocks to be in *HEAP and will delete | |
455 | *HEAP and store starting points for the next round into new *HEAP. */ | |
aa634f11 JZ |
456 | |
457 | static void | |
4682ae04 AJ |
458 | find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, |
459 | struct trace *traces, int *n_traces, int round, | |
8d261514 | 460 | bb_heap_t **heap, int number_of_rounds) |
aa634f11 JZ |
461 | { |
462 | /* Heap for discarded basic blocks which are possible starting points for | |
463 | the next round. */ | |
8d261514 | 464 | bb_heap_t *new_heap = new bb_heap_t (LONG_MIN); |
f7d0c571 | 465 | bool for_size = optimize_function_for_size_p (cfun); |
aa634f11 | 466 | |
8d261514 | 467 | while (!(*heap)->empty ()) |
aa634f11 JZ |
468 | { |
469 | basic_block bb; | |
470 | struct trace *trace; | |
471 | edge best_edge, e; | |
8d261514 | 472 | long key; |
628f6a4e | 473 | edge_iterator ei; |
aa634f11 | 474 | |
8d261514 | 475 | bb = (*heap)->extract_min (); |
aa634f11 JZ |
476 | bbd[bb->index].heap = NULL; |
477 | bbd[bb->index].node = NULL; | |
478 | ||
c263766c RH |
479 | if (dump_file) |
480 | fprintf (dump_file, "Getting bb %d\n", bb->index); | |
aa634f11 | 481 | |
4700dd70 | 482 | /* If the BB's frequency is too low, send BB to the next round. When |
c22cacf3 MS |
483 | partitioning hot/cold blocks into separate sections, make sure all |
484 | the cold blocks (and ONLY the cold blocks) go into the (extra) final | |
f7d0c571 | 485 | round. When optimizing for size, do not push to next round. */ |
750054a2 | 486 | |
f7d0c571 ZC |
487 | if (!for_size |
488 | && push_to_next_round_p (bb, round, number_of_rounds, exec_th, | |
489 | count_th)) | |
aa634f11 JZ |
490 | { |
491 | int key = bb_to_key (bb); | |
492 | bbd[bb->index].heap = new_heap; | |
8d261514 | 493 | bbd[bb->index].node = new_heap->insert (key, bb); |
aa634f11 | 494 | |
c263766c RH |
495 | if (dump_file) |
496 | fprintf (dump_file, | |
aa634f11 JZ |
497 | " Possible start point of next round: %d (key: %d)\n", |
498 | bb->index, key); | |
499 | continue; | |
500 | } | |
501 | ||
502 | trace = traces + *n_traces; | |
503 | trace->first = bb; | |
504 | trace->round = round; | |
505 | trace->length = 0; | |
87c8b4be | 506 | bbd[bb->index].in_trace = *n_traces; |
aa634f11 JZ |
507 | (*n_traces)++; |
508 | ||
509 | do | |
510 | { | |
511 | int prob, freq; | |
934677f9 | 512 | bool ends_in_call; |
aa634f11 JZ |
513 | |
514 | /* The probability and frequency of the best edge. */ | |
515 | int best_prob = INT_MIN / 2; | |
516 | int best_freq = INT_MIN / 2; | |
517 | ||
518 | best_edge = NULL; | |
519 | mark_bb_visited (bb, *n_traces); | |
520 | trace->length++; | |
521 | ||
c263766c RH |
522 | if (dump_file) |
523 | fprintf (dump_file, "Basic block %d was visited in trace %d\n", | |
aa634f11 JZ |
524 | bb->index, *n_traces - 1); |
525 | ||
c22cacf3 | 526 | ends_in_call = block_ends_with_call_p (bb); |
934677f9 | 527 | |
aa634f11 | 528 | /* Select the successor that will be placed after BB. */ |
628f6a4e | 529 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 | 530 | { |
298e6adc | 531 | gcc_assert (!(e->flags & EDGE_FAKE)); |
aa634f11 | 532 | |
fefa31b5 | 533 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
aa634f11 JZ |
534 | continue; |
535 | ||
bcc708fc MM |
536 | if (bb_visited_trace (e->dest) |
537 | && bb_visited_trace (e->dest) != *n_traces) | |
aa634f11 JZ |
538 | continue; |
539 | ||
87c8b4be | 540 | if (BB_PARTITION (e->dest) != BB_PARTITION (bb)) |
750054a2 CT |
541 | continue; |
542 | ||
aa634f11 | 543 | prob = e->probability; |
1651e640 | 544 | freq = e->dest->frequency; |
aa634f11 | 545 | |
934677f9 RH |
546 | /* The only sensible preference for a call instruction is the |
547 | fallthru edge. Don't bother selecting anything else. */ | |
548 | if (ends_in_call) | |
549 | { | |
550 | if (e->flags & EDGE_CAN_FALLTHRU) | |
551 | { | |
552 | best_edge = e; | |
553 | best_prob = prob; | |
554 | best_freq = freq; | |
555 | } | |
556 | continue; | |
557 | } | |
558 | ||
aa634f11 | 559 | /* Edge that cannot be fallthru or improbable or infrequent |
f7d0c571 ZC |
560 | successor (i.e. it is unsuitable successor). When optimizing |
561 | for size, ignore the probability and frequency. */ | |
aa634f11 | 562 | if (!(e->flags & EDGE_CAN_FALLTHRU) || (e->flags & EDGE_COMPLEX) |
f7d0c571 ZC |
563 | || ((prob < branch_th || EDGE_FREQUENCY (e) < exec_th |
564 | || e->count < count_th) && (!for_size))) | |
aa634f11 JZ |
565 | continue; |
566 | ||
750054a2 CT |
567 | /* If partitioning hot/cold basic blocks, don't consider edges |
568 | that cross section boundaries. */ | |
569 | ||
570 | if (better_edge_p (bb, e, prob, freq, best_prob, best_freq, | |
571 | best_edge)) | |
aa634f11 JZ |
572 | { |
573 | best_edge = e; | |
574 | best_prob = prob; | |
575 | best_freq = freq; | |
576 | } | |
577 | } | |
578 | ||
c8717368 | 579 | /* If the best destination has multiple predecessors, and can be |
6d9cc15b JZ |
580 | duplicated cheaper than a jump, don't allow it to be added |
581 | to a trace. We'll duplicate it when connecting traces. */ | |
628f6a4e | 582 | if (best_edge && EDGE_COUNT (best_edge->dest->preds) >= 2 |
6d9cc15b JZ |
583 | && copy_bb_p (best_edge->dest, 0)) |
584 | best_edge = NULL; | |
585 | ||
f7d0c571 ZC |
586 | /* If the best destination has multiple successors or predecessors, |
587 | don't allow it to be added when optimizing for size. This makes | |
588 | sure predecessors with smaller index are handled before the best | |
589 | destinarion. It breaks long trace and reduces long jumps. | |
590 | ||
591 | Take if-then-else as an example. | |
592 | A | |
593 | / \ | |
594 | B C | |
595 | \ / | |
596 | D | |
597 | If we do not remove the best edge B->D/C->D, the final order might | |
598 | be A B D ... C. C is at the end of the program. If D's successors | |
599 | and D are complicated, might need long jumps for A->C and C->D. | |
600 | Similar issue for order: A C D ... B. | |
601 | ||
602 | After removing the best edge, the final result will be ABCD/ ACBD. | |
603 | It does not add jump compared with the previous order. But it | |
688010ba | 604 | reduces the possibility of long jumps. */ |
f7d0c571 ZC |
605 | if (best_edge && for_size |
606 | && (EDGE_COUNT (best_edge->dest->succs) > 1 | |
607 | || EDGE_COUNT (best_edge->dest->preds) > 1)) | |
608 | best_edge = NULL; | |
609 | ||
aa634f11 | 610 | /* Add all non-selected successors to the heaps. */ |
628f6a4e | 611 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 JZ |
612 | { |
613 | if (e == best_edge | |
fefa31b5 | 614 | || e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
bcc708fc | 615 | || bb_visited_trace (e->dest)) |
aa634f11 JZ |
616 | continue; |
617 | ||
618 | key = bb_to_key (e->dest); | |
619 | ||
620 | if (bbd[e->dest->index].heap) | |
621 | { | |
622 | /* E->DEST is already in some heap. */ | |
8d261514 | 623 | if (key != bbd[e->dest->index].node->get_key ()) |
aa634f11 | 624 | { |
c263766c | 625 | if (dump_file) |
aa634f11 | 626 | { |
c263766c | 627 | fprintf (dump_file, |
aa634f11 JZ |
628 | "Changing key for bb %d from %ld to %ld.\n", |
629 | e->dest->index, | |
8d261514 | 630 | (long) bbd[e->dest->index].node->get_key (), |
aa634f11 JZ |
631 | key); |
632 | } | |
a3dc1a45 | 633 | bbd[e->dest->index].heap->replace_key |
8d261514 | 634 | (bbd[e->dest->index].node, key); |
aa634f11 JZ |
635 | } |
636 | } | |
637 | else | |
638 | { | |
8d261514 | 639 | bb_heap_t *which_heap = *heap; |
aa634f11 JZ |
640 | |
641 | prob = e->probability; | |
642 | freq = EDGE_FREQUENCY (e); | |
643 | ||
644 | if (!(e->flags & EDGE_CAN_FALLTHRU) | |
645 | || (e->flags & EDGE_COMPLEX) | |
646 | || prob < branch_th || freq < exec_th | |
647 | || e->count < count_th) | |
648 | { | |
750054a2 CT |
649 | /* When partitioning hot/cold basic blocks, make sure |
650 | the cold blocks (and only the cold blocks) all get | |
f7d0c571 ZC |
651 | pushed to the last round of trace collection. When |
652 | optimizing for size, do not push to next round. */ | |
750054a2 | 653 | |
f7d0c571 ZC |
654 | if (!for_size && push_to_next_round_p (e->dest, round, |
655 | number_of_rounds, | |
656 | exec_th, count_th)) | |
aa634f11 JZ |
657 | which_heap = new_heap; |
658 | } | |
295ae817 | 659 | |
aa634f11 | 660 | bbd[e->dest->index].heap = which_heap; |
8d261514 | 661 | bbd[e->dest->index].node = which_heap->insert (key, e->dest); |
295ae817 | 662 | |
c263766c | 663 | if (dump_file) |
aa634f11 | 664 | { |
c263766c | 665 | fprintf (dump_file, |
aa634f11 JZ |
666 | " Possible start of %s round: %d (key: %ld)\n", |
667 | (which_heap == new_heap) ? "next" : "this", | |
668 | e->dest->index, (long) key); | |
669 | } | |
670 | ||
671 | } | |
672 | } | |
673 | ||
674 | if (best_edge) /* Suitable successor was found. */ | |
675 | { | |
bcc708fc | 676 | if (bb_visited_trace (best_edge->dest) == *n_traces) |
aa634f11 JZ |
677 | { |
678 | /* We do nothing with one basic block loops. */ | |
679 | if (best_edge->dest != bb) | |
680 | { | |
681 | if (EDGE_FREQUENCY (best_edge) | |
682 | > 4 * best_edge->dest->frequency / 5) | |
683 | { | |
684 | /* The loop has at least 4 iterations. If the loop | |
685 | header is not the first block of the function | |
686 | we can rotate the loop. */ | |
687 | ||
fefa31b5 DM |
688 | if (best_edge->dest |
689 | != ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) | |
aa634f11 | 690 | { |
c263766c | 691 | if (dump_file) |
aa634f11 | 692 | { |
c263766c | 693 | fprintf (dump_file, |
aa634f11 JZ |
694 | "Rotating loop %d - %d\n", |
695 | best_edge->dest->index, bb->index); | |
696 | } | |
370369e1 | 697 | bb->aux = best_edge->dest; |
c22cacf3 MS |
698 | bbd[best_edge->dest->index].in_trace = |
699 | (*n_traces) - 1; | |
aa634f11 JZ |
700 | bb = rotate_loop (best_edge, trace, *n_traces); |
701 | } | |
702 | } | |
703 | else | |
704 | { | |
705 | /* The loop has less than 4 iterations. */ | |
706 | ||
c5cbcccf | 707 | if (single_succ_p (bb) |
efd8f750 | 708 | && copy_bb_p (best_edge->dest, |
4700dd70 EB |
709 | optimize_edge_for_speed_p |
710 | (best_edge))) | |
aa634f11 JZ |
711 | { |
712 | bb = copy_bb (best_edge->dest, best_edge, bb, | |
713 | *n_traces); | |
87c8b4be | 714 | trace->length++; |
aa634f11 JZ |
715 | } |
716 | } | |
717 | } | |
718 | ||
719 | /* Terminate the trace. */ | |
720 | break; | |
721 | } | |
722 | else | |
723 | { | |
724 | /* Check for a situation | |
725 | ||
726 | A | |
727 | /| | |
728 | B | | |
729 | \| | |
730 | C | |
731 | ||
732 | where | |
733 | EDGE_FREQUENCY (AB) + EDGE_FREQUENCY (BC) | |
734 | >= EDGE_FREQUENCY (AC). | |
735 | (i.e. 2 * B->frequency >= EDGE_FREQUENCY (AC) ) | |
736 | Best ordering is then A B C. | |
737 | ||
f7d0c571 ZC |
738 | When optimizing for size, A B C is always the best order. |
739 | ||
aa634f11 JZ |
740 | This situation is created for example by: |
741 | ||
742 | if (A) B; | |
743 | C; | |
744 | ||
745 | */ | |
746 | ||
628f6a4e | 747 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 JZ |
748 | if (e != best_edge |
749 | && (e->flags & EDGE_CAN_FALLTHRU) | |
750 | && !(e->flags & EDGE_COMPLEX) | |
bcc708fc | 751 | && !bb_visited_trace (e->dest) |
c5cbcccf | 752 | && single_pred_p (e->dest) |
bd454efd | 753 | && !(e->flags & EDGE_CROSSING) |
87c8b4be | 754 | && single_succ_p (e->dest) |
c5cbcccf ZD |
755 | && (single_succ_edge (e->dest)->flags |
756 | & EDGE_CAN_FALLTHRU) | |
757 | && !(single_succ_edge (e->dest)->flags & EDGE_COMPLEX) | |
758 | && single_succ (e->dest) == best_edge->dest | |
f7d0c571 ZC |
759 | && (2 * e->dest->frequency >= EDGE_FREQUENCY (best_edge) |
760 | || for_size)) | |
aa634f11 JZ |
761 | { |
762 | best_edge = e; | |
c263766c RH |
763 | if (dump_file) |
764 | fprintf (dump_file, "Selecting BB %d\n", | |
aa634f11 JZ |
765 | best_edge->dest->index); |
766 | break; | |
767 | } | |
768 | ||
370369e1 | 769 | bb->aux = best_edge->dest; |
87c8b4be | 770 | bbd[best_edge->dest->index].in_trace = (*n_traces) - 1; |
aa634f11 JZ |
771 | bb = best_edge->dest; |
772 | } | |
773 | } | |
774 | } | |
775 | while (best_edge); | |
776 | trace->last = bb; | |
777 | bbd[trace->first->index].start_of_trace = *n_traces - 1; | |
778 | bbd[trace->last->index].end_of_trace = *n_traces - 1; | |
779 | ||
780 | /* The trace is terminated so we have to recount the keys in heap | |
781 | (some block can have a lower key because now one of its predecessors | |
782 | is an end of the trace). */ | |
628f6a4e | 783 | FOR_EACH_EDGE (e, ei, bb->succs) |
aa634f11 | 784 | { |
fefa31b5 | 785 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
bcc708fc | 786 | || bb_visited_trace (e->dest)) |
aa634f11 JZ |
787 | continue; |
788 | ||
789 | if (bbd[e->dest->index].heap) | |
790 | { | |
791 | key = bb_to_key (e->dest); | |
8d261514 | 792 | if (key != bbd[e->dest->index].node->get_key ()) |
aa634f11 | 793 | { |
c263766c | 794 | if (dump_file) |
aa634f11 | 795 | { |
c263766c | 796 | fprintf (dump_file, |
aa634f11 JZ |
797 | "Changing key for bb %d from %ld to %ld.\n", |
798 | e->dest->index, | |
8d261514 | 799 | (long) bbd[e->dest->index].node->get_key (), key); |
aa634f11 | 800 | } |
a3dc1a45 | 801 | bbd[e->dest->index].heap->replace_key |
8d261514 | 802 | (bbd[e->dest->index].node, key); |
aa634f11 JZ |
803 | } |
804 | } | |
805 | } | |
806 | } | |
807 | ||
8d261514 | 808 | delete (*heap); |
aa634f11 JZ |
809 | |
810 | /* "Return" the new heap. */ | |
811 | *heap = new_heap; | |
812 | } | |
813 | ||
814 | /* Create a duplicate of the basic block OLD_BB and redirect edge E to it, add | |
815 | it to trace after BB, mark OLD_BB visited and update pass' data structures | |
816 | (TRACE is a number of trace which OLD_BB is duplicated to). */ | |
295ae817 | 817 | |
f008a564 | 818 | static basic_block |
4682ae04 | 819 | copy_bb (basic_block old_bb, edge e, basic_block bb, int trace) |
f008a564 | 820 | { |
aa634f11 JZ |
821 | basic_block new_bb; |
822 | ||
b9a66240 | 823 | new_bb = duplicate_block (old_bb, e, bb); |
076c7ab8 | 824 | BB_COPY_PARTITION (new_bb, old_bb); |
9fb32434 | 825 | |
298e6adc | 826 | gcc_assert (e->dest == new_bb); |
298e6adc | 827 | |
c263766c RH |
828 | if (dump_file) |
829 | fprintf (dump_file, | |
aa634f11 JZ |
830 | "Duplicated bb %d (created bb %d)\n", |
831 | old_bb->index, new_bb->index); | |
f008a564 | 832 | |
8b1c6fd7 DM |
833 | if (new_bb->index >= array_size |
834 | || last_basic_block_for_fn (cfun) > array_size) | |
295ae817 | 835 | { |
aa634f11 JZ |
836 | int i; |
837 | int new_size; | |
838 | ||
8b1c6fd7 | 839 | new_size = MAX (last_basic_block_for_fn (cfun), new_bb->index + 1); |
aa634f11 | 840 | new_size = GET_ARRAY_SIZE (new_size); |
f883e0a7 | 841 | bbd = XRESIZEVEC (bbro_basic_block_data, bbd, new_size); |
aa634f11 JZ |
842 | for (i = array_size; i < new_size; i++) |
843 | { | |
844 | bbd[i].start_of_trace = -1; | |
845 | bbd[i].end_of_trace = -1; | |
bcc708fc MM |
846 | bbd[i].in_trace = -1; |
847 | bbd[i].visited = 0; | |
aa634f11 JZ |
848 | bbd[i].heap = NULL; |
849 | bbd[i].node = NULL; | |
850 | } | |
851 | array_size = new_size; | |
295ae817 | 852 | |
c263766c | 853 | if (dump_file) |
aa634f11 | 854 | { |
c263766c | 855 | fprintf (dump_file, |
aa634f11 JZ |
856 | "Growing the dynamic array to %d elements.\n", |
857 | array_size); | |
858 | } | |
295ae817 | 859 | } |
aa634f11 | 860 | |
bcc708fc MM |
861 | gcc_assert (!bb_visited_trace (e->dest)); |
862 | mark_bb_visited (new_bb, trace); | |
863 | new_bb->aux = bb->aux; | |
864 | bb->aux = new_bb; | |
865 | ||
87c8b4be CT |
866 | bbd[new_bb->index].in_trace = trace; |
867 | ||
aa634f11 JZ |
868 | return new_bb; |
869 | } | |
870 | ||
871 | /* Compute and return the key (for the heap) of the basic block BB. */ | |
872 | ||
8d261514 | 873 | static long |
4682ae04 | 874 | bb_to_key (basic_block bb) |
aa634f11 JZ |
875 | { |
876 | edge e; | |
628f6a4e | 877 | edge_iterator ei; |
aa634f11 JZ |
878 | int priority = 0; |
879 | ||
f7d0c571 ZC |
880 | /* Use index as key to align with its original order. */ |
881 | if (optimize_function_for_size_p (cfun)) | |
882 | return bb->index; | |
883 | ||
aa634f11 | 884 | /* Do not start in probably never executed blocks. */ |
750054a2 | 885 | |
076c7ab8 | 886 | if (BB_PARTITION (bb) == BB_COLD_PARTITION |
2eb712b4 | 887 | || probably_never_executed_bb_p (cfun, bb)) |
aa634f11 JZ |
888 | return BB_FREQ_MAX; |
889 | ||
890 | /* Prefer blocks whose predecessor is an end of some trace | |
891 | or whose predecessor edge is EDGE_DFS_BACK. */ | |
628f6a4e | 892 | FOR_EACH_EDGE (e, ei, bb->preds) |
402209ff | 893 | { |
fefa31b5 DM |
894 | if ((e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
895 | && bbd[e->src->index].end_of_trace >= 0) | |
aa634f11 JZ |
896 | || (e->flags & EDGE_DFS_BACK)) |
897 | { | |
898 | int edge_freq = EDGE_FREQUENCY (e); | |
899 | ||
900 | if (edge_freq > priority) | |
901 | priority = edge_freq; | |
902 | } | |
402209ff | 903 | } |
295ae817 | 904 | |
aa634f11 JZ |
905 | if (priority) |
906 | /* The block with priority should have significantly lower key. */ | |
907 | return -(100 * BB_FREQ_MAX + 100 * priority + bb->frequency); | |
4700dd70 | 908 | |
aa634f11 JZ |
909 | return -bb->frequency; |
910 | } | |
911 | ||
912 | /* Return true when the edge E from basic block BB is better than the temporary | |
913 | best edge (details are in function). The probability of edge E is PROB. The | |
914 | frequency of the successor is FREQ. The current best probability is | |
915 | BEST_PROB, the best frequency is BEST_FREQ. | |
916 | The edge is considered to be equivalent when PROB does not differ much from | |
917 | BEST_PROB; similarly for frequency. */ | |
918 | ||
919 | static bool | |
4700dd70 EB |
920 | better_edge_p (const_basic_block bb, const_edge e, int prob, int freq, |
921 | int best_prob, int best_freq, const_edge cur_best_edge) | |
aa634f11 JZ |
922 | { |
923 | bool is_better_edge; | |
f008a564 | 924 | |
aa634f11 JZ |
925 | /* The BEST_* values do not have to be best, but can be a bit smaller than |
926 | maximum values. */ | |
927 | int diff_prob = best_prob / 10; | |
928 | int diff_freq = best_freq / 10; | |
f008a564 | 929 | |
f7d0c571 ZC |
930 | /* The smaller one is better to keep the original order. */ |
931 | if (optimize_function_for_size_p (cfun)) | |
932 | return !cur_best_edge | |
933 | || cur_best_edge->dest->index > e->dest->index; | |
934 | ||
aa634f11 JZ |
935 | if (prob > best_prob + diff_prob) |
936 | /* The edge has higher probability than the temporary best edge. */ | |
937 | is_better_edge = true; | |
938 | else if (prob < best_prob - diff_prob) | |
939 | /* The edge has lower probability than the temporary best edge. */ | |
940 | is_better_edge = false; | |
941 | else if (freq < best_freq - diff_freq) | |
942 | /* The edge and the temporary best edge have almost equivalent | |
943 | probabilities. The higher frequency of a successor now means | |
944 | that there is another edge going into that successor. | |
945 | This successor has lower frequency so it is better. */ | |
946 | is_better_edge = true; | |
947 | else if (freq > best_freq + diff_freq) | |
948 | /* This successor has higher frequency so it is worse. */ | |
949 | is_better_edge = false; | |
950 | else if (e->dest->prev_bb == bb) | |
951 | /* The edges have equivalent probabilities and the successors | |
952 | have equivalent frequencies. Select the previous successor. */ | |
953 | is_better_edge = true; | |
954 | else | |
955 | is_better_edge = false; | |
956 | ||
750054a2 CT |
957 | /* If we are doing hot/cold partitioning, make sure that we always favor |
958 | non-crossing edges over crossing edges. */ | |
959 | ||
960 | if (!is_better_edge | |
c22cacf3 MS |
961 | && flag_reorder_blocks_and_partition |
962 | && cur_best_edge | |
bd454efd SB |
963 | && (cur_best_edge->flags & EDGE_CROSSING) |
964 | && !(e->flags & EDGE_CROSSING)) | |
750054a2 CT |
965 | is_better_edge = true; |
966 | ||
aa634f11 JZ |
967 | return is_better_edge; |
968 | } | |
969 | ||
f7d0c571 ZC |
970 | /* Return true when the edge E is better than the temporary best edge |
971 | CUR_BEST_EDGE. If SRC_INDEX_P is true, the function compares the src bb of | |
972 | E and CUR_BEST_EDGE; otherwise it will compare the dest bb. | |
973 | BEST_LEN is the trace length of src (or dest) bb in CUR_BEST_EDGE. | |
974 | TRACES record the information about traces. | |
975 | When optimizing for size, the edge with smaller index is better. | |
976 | When optimizing for speed, the edge with bigger probability or longer trace | |
977 | is better. */ | |
978 | ||
979 | static bool | |
980 | connect_better_edge_p (const_edge e, bool src_index_p, int best_len, | |
981 | const_edge cur_best_edge, struct trace *traces) | |
982 | { | |
983 | int e_index; | |
984 | int b_index; | |
985 | bool is_better_edge; | |
986 | ||
987 | if (!cur_best_edge) | |
988 | return true; | |
989 | ||
990 | if (optimize_function_for_size_p (cfun)) | |
991 | { | |
992 | e_index = src_index_p ? e->src->index : e->dest->index; | |
993 | b_index = src_index_p ? cur_best_edge->src->index | |
994 | : cur_best_edge->dest->index; | |
995 | /* The smaller one is better to keep the original order. */ | |
996 | return b_index > e_index; | |
997 | } | |
998 | ||
999 | if (src_index_p) | |
1000 | { | |
1001 | e_index = e->src->index; | |
1002 | ||
1003 | if (e->probability > cur_best_edge->probability) | |
1004 | /* The edge has higher probability than the temporary best edge. */ | |
1005 | is_better_edge = true; | |
1006 | else if (e->probability < cur_best_edge->probability) | |
1007 | /* The edge has lower probability than the temporary best edge. */ | |
1008 | is_better_edge = false; | |
1009 | else if (traces[bbd[e_index].end_of_trace].length > best_len) | |
1010 | /* The edge and the temporary best edge have equivalent probabilities. | |
1011 | The edge with longer trace is better. */ | |
1012 | is_better_edge = true; | |
1013 | else | |
1014 | is_better_edge = false; | |
1015 | } | |
1016 | else | |
1017 | { | |
1018 | e_index = e->dest->index; | |
1019 | ||
1020 | if (e->probability > cur_best_edge->probability) | |
1021 | /* The edge has higher probability than the temporary best edge. */ | |
1022 | is_better_edge = true; | |
1023 | else if (e->probability < cur_best_edge->probability) | |
1024 | /* The edge has lower probability than the temporary best edge. */ | |
1025 | is_better_edge = false; | |
1026 | else if (traces[bbd[e_index].start_of_trace].length > best_len) | |
1027 | /* The edge and the temporary best edge have equivalent probabilities. | |
1028 | The edge with longer trace is better. */ | |
1029 | is_better_edge = true; | |
1030 | else | |
1031 | is_better_edge = false; | |
1032 | } | |
1033 | ||
1034 | return is_better_edge; | |
1035 | } | |
1036 | ||
aa634f11 JZ |
1037 | /* Connect traces in array TRACES, N_TRACES is the count of traces. */ |
1038 | ||
1039 | static void | |
4682ae04 | 1040 | connect_traces (int n_traces, struct trace *traces) |
aa634f11 JZ |
1041 | { |
1042 | int i; | |
1043 | bool *connected; | |
87c8b4be | 1044 | bool two_passes; |
aa634f11 | 1045 | int last_trace; |
87c8b4be CT |
1046 | int current_pass; |
1047 | int current_partition; | |
aa634f11 JZ |
1048 | int freq_threshold; |
1049 | gcov_type count_threshold; | |
f7d0c571 | 1050 | bool for_size = optimize_function_for_size_p (cfun); |
aa634f11 JZ |
1051 | |
1052 | freq_threshold = max_entry_frequency * DUPLICATION_THRESHOLD / 1000; | |
1053 | if (max_entry_count < INT_MAX / 1000) | |
1054 | count_threshold = max_entry_count * DUPLICATION_THRESHOLD / 1000; | |
1055 | else | |
1056 | count_threshold = max_entry_count / 1000 * DUPLICATION_THRESHOLD; | |
1057 | ||
5ed6ace5 | 1058 | connected = XCNEWVEC (bool, n_traces); |
aa634f11 | 1059 | last_trace = -1; |
87c8b4be CT |
1060 | current_pass = 1; |
1061 | current_partition = BB_PARTITION (traces[0].first); | |
1062 | two_passes = false; | |
750054a2 | 1063 | |
af205f67 | 1064 | if (crtl->has_bb_partition) |
87c8b4be | 1065 | for (i = 0; i < n_traces && !two_passes; i++) |
c22cacf3 | 1066 | if (BB_PARTITION (traces[0].first) |
87c8b4be CT |
1067 | != BB_PARTITION (traces[i].first)) |
1068 | two_passes = true; | |
1069 | ||
1070 | for (i = 0; i < n_traces || (two_passes && current_pass == 1) ; i++) | |
295ae817 | 1071 | { |
aa634f11 JZ |
1072 | int t = i; |
1073 | int t2; | |
1074 | edge e, best; | |
1075 | int best_len; | |
295ae817 | 1076 | |
87c8b4be | 1077 | if (i >= n_traces) |
750054a2 | 1078 | { |
41806d92 NS |
1079 | gcc_assert (two_passes && current_pass == 1); |
1080 | i = 0; | |
1081 | t = i; | |
1082 | current_pass = 2; | |
1083 | if (current_partition == BB_HOT_PARTITION) | |
1084 | current_partition = BB_COLD_PARTITION; | |
87c8b4be | 1085 | else |
41806d92 | 1086 | current_partition = BB_HOT_PARTITION; |
750054a2 | 1087 | } |
c22cacf3 | 1088 | |
aa634f11 JZ |
1089 | if (connected[t]) |
1090 | continue; | |
f008a564 | 1091 | |
c22cacf3 | 1092 | if (two_passes |
87c8b4be CT |
1093 | && BB_PARTITION (traces[t].first) != current_partition) |
1094 | continue; | |
1095 | ||
aa634f11 | 1096 | connected[t] = true; |
b0cc7919 | 1097 | |
aa634f11 JZ |
1098 | /* Find the predecessor traces. */ |
1099 | for (t2 = t; t2 > 0;) | |
1100 | { | |
628f6a4e | 1101 | edge_iterator ei; |
aa634f11 JZ |
1102 | best = NULL; |
1103 | best_len = 0; | |
628f6a4e | 1104 | FOR_EACH_EDGE (e, ei, traces[t2].first->preds) |
aa634f11 JZ |
1105 | { |
1106 | int si = e->src->index; | |
b0cc7919 | 1107 | |
fefa31b5 | 1108 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
aa634f11 JZ |
1109 | && (e->flags & EDGE_CAN_FALLTHRU) |
1110 | && !(e->flags & EDGE_COMPLEX) | |
1111 | && bbd[si].end_of_trace >= 0 | |
1112 | && !connected[bbd[si].end_of_trace] | |
87c8b4be | 1113 | && (BB_PARTITION (e->src) == current_partition) |
f7d0c571 | 1114 | && connect_better_edge_p (e, true, best_len, best, traces)) |
aa634f11 JZ |
1115 | { |
1116 | best = e; | |
1117 | best_len = traces[bbd[si].end_of_trace].length; | |
1118 | } | |
1119 | } | |
1120 | if (best) | |
1121 | { | |
370369e1 | 1122 | best->src->aux = best->dest; |
aa634f11 JZ |
1123 | t2 = bbd[best->src->index].end_of_trace; |
1124 | connected[t2] = true; | |
750054a2 | 1125 | |
c263766c | 1126 | if (dump_file) |
aa634f11 | 1127 | { |
c263766c | 1128 | fprintf (dump_file, "Connection: %d %d\n", |
aa634f11 JZ |
1129 | best->src->index, best->dest->index); |
1130 | } | |
1131 | } | |
1132 | else | |
1133 | break; | |
1134 | } | |
f008a564 | 1135 | |
aa634f11 | 1136 | if (last_trace >= 0) |
370369e1 | 1137 | traces[last_trace].last->aux = traces[t2].first; |
aa634f11 JZ |
1138 | last_trace = t; |
1139 | ||
1140 | /* Find the successor traces. */ | |
1141 | while (1) | |
b0cc7919 | 1142 | { |
aa634f11 | 1143 | /* Find the continuation of the chain. */ |
628f6a4e | 1144 | edge_iterator ei; |
aa634f11 JZ |
1145 | best = NULL; |
1146 | best_len = 0; | |
628f6a4e | 1147 | FOR_EACH_EDGE (e, ei, traces[t].last->succs) |
aa634f11 JZ |
1148 | { |
1149 | int di = e->dest->index; | |
1150 | ||
fefa31b5 | 1151 | if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
aa634f11 JZ |
1152 | && (e->flags & EDGE_CAN_FALLTHRU) |
1153 | && !(e->flags & EDGE_COMPLEX) | |
1154 | && bbd[di].start_of_trace >= 0 | |
1155 | && !connected[bbd[di].start_of_trace] | |
87c8b4be | 1156 | && (BB_PARTITION (e->dest) == current_partition) |
f7d0c571 | 1157 | && connect_better_edge_p (e, false, best_len, best, traces)) |
aa634f11 JZ |
1158 | { |
1159 | best = e; | |
1160 | best_len = traces[bbd[di].start_of_trace].length; | |
1161 | } | |
1162 | } | |
1163 | ||
f7d0c571 ZC |
1164 | if (for_size) |
1165 | { | |
1166 | if (!best) | |
1167 | /* Stop finding the successor traces. */ | |
1168 | break; | |
1169 | ||
1170 | /* It is OK to connect block n with block n + 1 or a block | |
1171 | before n. For others, only connect to the loop header. */ | |
1172 | if (best->dest->index > (traces[t].last->index + 1)) | |
1173 | { | |
1174 | int count = EDGE_COUNT (best->dest->preds); | |
1175 | ||
1176 | FOR_EACH_EDGE (e, ei, best->dest->preds) | |
1177 | if (e->flags & EDGE_DFS_BACK) | |
1178 | count--; | |
1179 | ||
1180 | /* If dest has multiple predecessors, skip it. We expect | |
1181 | that one predecessor with smaller index connects with it | |
1182 | later. */ | |
1183 | if (count != 1) | |
1184 | break; | |
1185 | } | |
1186 | ||
1187 | /* Only connect Trace n with Trace n + 1. It is conservative | |
1188 | to keep the order as close as possible to the original order. | |
1189 | It also helps to reduce long jumps. */ | |
1190 | if (last_trace != bbd[best->dest->index].start_of_trace - 1) | |
1191 | break; | |
1192 | ||
1193 | if (dump_file) | |
1194 | fprintf (dump_file, "Connection: %d %d\n", | |
1195 | best->src->index, best->dest->index); | |
1196 | ||
1197 | t = bbd[best->dest->index].start_of_trace; | |
1198 | traces[last_trace].last->aux = traces[t].first; | |
1199 | connected[t] = true; | |
1200 | last_trace = t; | |
1201 | } | |
1202 | else if (best) | |
aa634f11 | 1203 | { |
c263766c | 1204 | if (dump_file) |
aa634f11 | 1205 | { |
c263766c | 1206 | fprintf (dump_file, "Connection: %d %d\n", |
aa634f11 JZ |
1207 | best->src->index, best->dest->index); |
1208 | } | |
1209 | t = bbd[best->dest->index].start_of_trace; | |
370369e1 | 1210 | traces[last_trace].last->aux = traces[t].first; |
aa634f11 JZ |
1211 | connected[t] = true; |
1212 | last_trace = t; | |
1213 | } | |
1214 | else | |
1215 | { | |
1216 | /* Try to connect the traces by duplication of 1 block. */ | |
1217 | edge e2; | |
1218 | basic_block next_bb = NULL; | |
99dc7277 | 1219 | bool try_copy = false; |
aa634f11 | 1220 | |
628f6a4e | 1221 | FOR_EACH_EDGE (e, ei, traces[t].last->succs) |
fefa31b5 | 1222 | if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
aa634f11 JZ |
1223 | && (e->flags & EDGE_CAN_FALLTHRU) |
1224 | && !(e->flags & EDGE_COMPLEX) | |
99dc7277 | 1225 | && (!best || e->probability > best->probability)) |
aa634f11 | 1226 | { |
628f6a4e | 1227 | edge_iterator ei; |
aa634f11 JZ |
1228 | edge best2 = NULL; |
1229 | int best2_len = 0; | |
1230 | ||
6d9cc15b JZ |
1231 | /* If the destination is a start of a trace which is only |
1232 | one block long, then no need to search the successor | |
99dc7277 | 1233 | blocks of the trace. Accept it. */ |
6d9cc15b JZ |
1234 | if (bbd[e->dest->index].start_of_trace >= 0 |
1235 | && traces[bbd[e->dest->index].start_of_trace].length | |
1236 | == 1) | |
1237 | { | |
1238 | best = e; | |
1239 | try_copy = true; | |
1240 | continue; | |
1241 | } | |
99dc7277 | 1242 | |
628f6a4e | 1243 | FOR_EACH_EDGE (e2, ei, e->dest->succs) |
aa634f11 JZ |
1244 | { |
1245 | int di = e2->dest->index; | |
1246 | ||
fefa31b5 | 1247 | if (e2->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
aa634f11 JZ |
1248 | || ((e2->flags & EDGE_CAN_FALLTHRU) |
1249 | && !(e2->flags & EDGE_COMPLEX) | |
1250 | && bbd[di].start_of_trace >= 0 | |
1251 | && !connected[bbd[di].start_of_trace] | |
4700dd70 EB |
1252 | && BB_PARTITION (e2->dest) == current_partition |
1253 | && EDGE_FREQUENCY (e2) >= freq_threshold | |
1254 | && e2->count >= count_threshold | |
aa634f11 JZ |
1255 | && (!best2 |
1256 | || e2->probability > best2->probability | |
1257 | || (e2->probability == best2->probability | |
1258 | && traces[bbd[di].start_of_trace].length | |
1259 | > best2_len)))) | |
1260 | { | |
1261 | best = e; | |
1262 | best2 = e2; | |
fefa31b5 | 1263 | if (e2->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
aa634f11 JZ |
1264 | best2_len = traces[bbd[di].start_of_trace].length; |
1265 | else | |
1266 | best2_len = INT_MAX; | |
1267 | next_bb = e2->dest; | |
99dc7277 | 1268 | try_copy = true; |
aa634f11 JZ |
1269 | } |
1270 | } | |
1271 | } | |
99dc7277 | 1272 | |
af205f67 | 1273 | if (crtl->has_bb_partition) |
750054a2 CT |
1274 | try_copy = false; |
1275 | ||
99dc7277 RH |
1276 | /* Copy tiny blocks always; copy larger blocks only when the |
1277 | edge is traversed frequently enough. */ | |
1278 | if (try_copy | |
1279 | && copy_bb_p (best->dest, | |
efd8f750 | 1280 | optimize_edge_for_speed_p (best) |
99dc7277 RH |
1281 | && EDGE_FREQUENCY (best) >= freq_threshold |
1282 | && best->count >= count_threshold)) | |
aa634f11 JZ |
1283 | { |
1284 | basic_block new_bb; | |
1285 | ||
c263766c | 1286 | if (dump_file) |
aa634f11 | 1287 | { |
c263766c | 1288 | fprintf (dump_file, "Connection: %d %d ", |
aa634f11 | 1289 | traces[t].last->index, best->dest->index); |
99dc7277 | 1290 | if (!next_bb) |
c263766c | 1291 | fputc ('\n', dump_file); |
fefa31b5 | 1292 | else if (next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
c263766c | 1293 | fprintf (dump_file, "exit\n"); |
aa634f11 | 1294 | else |
c263766c | 1295 | fprintf (dump_file, "%d\n", next_bb->index); |
aa634f11 JZ |
1296 | } |
1297 | ||
1298 | new_bb = copy_bb (best->dest, best, traces[t].last, t); | |
1299 | traces[t].last = new_bb; | |
fefa31b5 | 1300 | if (next_bb && next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
aa634f11 JZ |
1301 | { |
1302 | t = bbd[next_bb->index].start_of_trace; | |
370369e1 | 1303 | traces[last_trace].last->aux = traces[t].first; |
aa634f11 JZ |
1304 | connected[t] = true; |
1305 | last_trace = t; | |
1306 | } | |
1307 | else | |
1308 | break; /* Stop finding the successor traces. */ | |
1309 | } | |
1310 | else | |
1311 | break; /* Stop finding the successor traces. */ | |
1312 | } | |
b0cc7919 | 1313 | } |
aa634f11 JZ |
1314 | } |
1315 | ||
c263766c | 1316 | if (dump_file) |
aa634f11 JZ |
1317 | { |
1318 | basic_block bb; | |
f008a564 | 1319 | |
c263766c | 1320 | fprintf (dump_file, "Final order:\n"); |
f883e0a7 | 1321 | for (bb = traces[0].first; bb; bb = (basic_block) bb->aux) |
c263766c RH |
1322 | fprintf (dump_file, "%d ", bb->index); |
1323 | fprintf (dump_file, "\n"); | |
1324 | fflush (dump_file); | |
295ae817 JE |
1325 | } |
1326 | ||
aa634f11 JZ |
1327 | FREE (connected); |
1328 | } | |
1329 | ||
1330 | /* Return true when BB can and should be copied. CODE_MAY_GROW is true | |
1331 | when code size is allowed to grow by duplication. */ | |
1332 | ||
1333 | static bool | |
9678086d | 1334 | copy_bb_p (const_basic_block bb, int code_may_grow) |
aa634f11 JZ |
1335 | { |
1336 | int size = 0; | |
1337 | int max_size = uncond_jump_length; | |
e93768e4 | 1338 | rtx_insn *insn; |
aa634f11 JZ |
1339 | |
1340 | if (!bb->frequency) | |
1341 | return false; | |
628f6a4e | 1342 | if (EDGE_COUNT (bb->preds) < 2) |
aa634f11 | 1343 | return false; |
6de9cd9a | 1344 | if (!can_duplicate_block_p (bb)) |
aa634f11 JZ |
1345 | return false; |
1346 | ||
6ae533cf | 1347 | /* Avoid duplicating blocks which have many successors (PR/13430). */ |
628f6a4e BE |
1348 | if (EDGE_COUNT (bb->succs) > 8) |
1349 | return false; | |
6ae533cf | 1350 | |
efd8f750 | 1351 | if (code_may_grow && optimize_bb_for_speed_p (bb)) |
f935b9e0 | 1352 | max_size *= PARAM_VALUE (PARAM_MAX_GROW_COPY_BB_INSNS); |
aa634f11 | 1353 | |
bbcb0c05 | 1354 | FOR_BB_INSNS (bb, insn) |
f008a564 | 1355 | { |
aa634f11 | 1356 | if (INSN_P (insn)) |
070a7956 | 1357 | size += get_attr_min_length (insn); |
f008a564 | 1358 | } |
295ae817 | 1359 | |
aa634f11 JZ |
1360 | if (size <= max_size) |
1361 | return true; | |
1362 | ||
c263766c | 1363 | if (dump_file) |
f008a564 | 1364 | { |
c263766c | 1365 | fprintf (dump_file, |
aa634f11 JZ |
1366 | "Block %d can't be copied because its size = %d.\n", |
1367 | bb->index, size); | |
f008a564 | 1368 | } |
295ae817 | 1369 | |
aa634f11 JZ |
1370 | return false; |
1371 | } | |
1372 | ||
1373 | /* Return the length of unconditional jump instruction. */ | |
1374 | ||
ffe14686 | 1375 | int |
4682ae04 | 1376 | get_uncond_jump_length (void) |
aa634f11 | 1377 | { |
aa634f11 JZ |
1378 | int length; |
1379 | ||
ed2b2162 | 1380 | start_sequence (); |
e67d1102 | 1381 | rtx_code_label *label = emit_label (gen_label_rtx ()); |
ec4a505f | 1382 | rtx_insn *jump = emit_jump_insn (targetm.gen_jump (label)); |
070a7956 | 1383 | length = get_attr_min_length (jump); |
ed2b2162 | 1384 | end_sequence (); |
aa634f11 | 1385 | |
aa634f11 | 1386 | return length; |
295ae817 JE |
1387 | } |
1388 | ||
0be7e7a6 RH |
1389 | /* The landing pad OLD_LP, in block OLD_BB, has edges from both partitions. |
1390 | Duplicate the landing pad and split the edges so that no EH edge | |
1391 | crosses partitions. */ | |
1392 | ||
1393 | static void | |
1394 | fix_up_crossing_landing_pad (eh_landing_pad old_lp, basic_block old_bb) | |
1395 | { | |
1396 | eh_landing_pad new_lp; | |
1397 | basic_block new_bb, last_bb, post_bb; | |
e67d1102 | 1398 | rtx_insn *jump; |
0be7e7a6 RH |
1399 | unsigned new_partition; |
1400 | edge_iterator ei; | |
1401 | edge e; | |
1402 | ||
1403 | /* Generate the new landing-pad structure. */ | |
1404 | new_lp = gen_eh_landing_pad (old_lp->region); | |
1405 | new_lp->post_landing_pad = old_lp->post_landing_pad; | |
1406 | new_lp->landing_pad = gen_label_rtx (); | |
1407 | LABEL_PRESERVE_P (new_lp->landing_pad) = 1; | |
1408 | ||
1409 | /* Put appropriate instructions in new bb. */ | |
e67d1102 | 1410 | rtx_code_label *new_label = emit_label (new_lp->landing_pad); |
0be7e7a6 RH |
1411 | |
1412 | expand_dw2_landing_pad_for_region (old_lp->region); | |
1413 | ||
1414 | post_bb = BLOCK_FOR_INSN (old_lp->landing_pad); | |
1415 | post_bb = single_succ (post_bb); | |
e67d1102 | 1416 | rtx_code_label *post_label = block_label (post_bb); |
ec4a505f | 1417 | jump = emit_jump_insn (targetm.gen_jump (post_label)); |
0be7e7a6 RH |
1418 | JUMP_LABEL (jump) = post_label; |
1419 | ||
1420 | /* Create new basic block to be dest for lp. */ | |
fefa31b5 | 1421 | last_bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb; |
0be7e7a6 RH |
1422 | new_bb = create_basic_block (new_label, jump, last_bb); |
1423 | new_bb->aux = last_bb->aux; | |
1424 | last_bb->aux = new_bb; | |
1425 | ||
1426 | emit_barrier_after_bb (new_bb); | |
1427 | ||
1428 | make_edge (new_bb, post_bb, 0); | |
1429 | ||
1430 | /* Make sure new bb is in the other partition. */ | |
1431 | new_partition = BB_PARTITION (old_bb); | |
1432 | new_partition ^= BB_HOT_PARTITION | BB_COLD_PARTITION; | |
1433 | BB_SET_PARTITION (new_bb, new_partition); | |
1434 | ||
1435 | /* Fix up the edges. */ | |
1436 | for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)) != NULL; ) | |
1437 | if (BB_PARTITION (e->src) == new_partition) | |
1438 | { | |
e93768e4 | 1439 | rtx_insn *insn = BB_END (e->src); |
0be7e7a6 RH |
1440 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
1441 | ||
1442 | gcc_assert (note != NULL); | |
1443 | gcc_checking_assert (INTVAL (XEXP (note, 0)) == old_lp->index); | |
1444 | XEXP (note, 0) = GEN_INT (new_lp->index); | |
1445 | ||
1446 | /* Adjust the edge to the new destination. */ | |
1447 | redirect_edge_succ (e, new_bb); | |
1448 | } | |
1449 | else | |
1450 | ei_next (&ei); | |
1451 | } | |
1452 | ||
600b5b1d TJ |
1453 | |
1454 | /* Ensure that all hot bbs are included in a hot path through the | |
1455 | procedure. This is done by calling this function twice, once | |
1456 | with WALK_UP true (to look for paths from the entry to hot bbs) and | |
1457 | once with WALK_UP false (to look for paths from hot bbs to the exit). | |
1458 | Returns the updated value of COLD_BB_COUNT and adds newly-hot bbs | |
1459 | to BBS_IN_HOT_PARTITION. */ | |
1460 | ||
1461 | static unsigned int | |
1462 | sanitize_hot_paths (bool walk_up, unsigned int cold_bb_count, | |
1463 | vec<basic_block> *bbs_in_hot_partition) | |
1464 | { | |
1465 | /* Callers check this. */ | |
1466 | gcc_checking_assert (cold_bb_count); | |
1467 | ||
1468 | /* Keep examining hot bbs while we still have some left to check | |
1469 | and there are remaining cold bbs. */ | |
1470 | vec<basic_block> hot_bbs_to_check = bbs_in_hot_partition->copy (); | |
1471 | while (! hot_bbs_to_check.is_empty () | |
1472 | && cold_bb_count) | |
1473 | { | |
1474 | basic_block bb = hot_bbs_to_check.pop (); | |
1475 | vec<edge, va_gc> *edges = walk_up ? bb->preds : bb->succs; | |
1476 | edge e; | |
1477 | edge_iterator ei; | |
1478 | int highest_probability = 0; | |
1479 | int highest_freq = 0; | |
1480 | gcov_type highest_count = 0; | |
1481 | bool found = false; | |
1482 | ||
1483 | /* Walk the preds/succs and check if there is at least one already | |
1484 | marked hot. Keep track of the most frequent pred/succ so that we | |
1485 | can mark it hot if we don't find one. */ | |
1486 | FOR_EACH_EDGE (e, ei, edges) | |
1487 | { | |
1488 | basic_block reach_bb = walk_up ? e->src : e->dest; | |
1489 | ||
1490 | if (e->flags & EDGE_DFS_BACK) | |
1491 | continue; | |
1492 | ||
1493 | if (BB_PARTITION (reach_bb) != BB_COLD_PARTITION) | |
1494 | { | |
1495 | found = true; | |
1496 | break; | |
1497 | } | |
1498 | /* The following loop will look for the hottest edge via | |
1499 | the edge count, if it is non-zero, then fallback to the edge | |
1500 | frequency and finally the edge probability. */ | |
1501 | if (e->count > highest_count) | |
1502 | highest_count = e->count; | |
1503 | int edge_freq = EDGE_FREQUENCY (e); | |
1504 | if (edge_freq > highest_freq) | |
1505 | highest_freq = edge_freq; | |
1506 | if (e->probability > highest_probability) | |
1507 | highest_probability = e->probability; | |
1508 | } | |
1509 | ||
1510 | /* If bb is reached by (or reaches, in the case of !WALK_UP) another hot | |
1511 | block (or unpartitioned, e.g. the entry block) then it is ok. If not, | |
1512 | then the most frequent pred (or succ) needs to be adjusted. In the | |
1513 | case where multiple preds/succs have the same frequency (e.g. a | |
1514 | 50-50 branch), then both will be adjusted. */ | |
1515 | if (found) | |
1516 | continue; | |
1517 | ||
1518 | FOR_EACH_EDGE (e, ei, edges) | |
1519 | { | |
1520 | if (e->flags & EDGE_DFS_BACK) | |
1521 | continue; | |
1522 | /* Select the hottest edge using the edge count, if it is non-zero, | |
1523 | then fallback to the edge frequency and finally the edge | |
1524 | probability. */ | |
1525 | if (highest_count) | |
1526 | { | |
1527 | if (e->count < highest_count) | |
1528 | continue; | |
1529 | } | |
1530 | else if (highest_freq) | |
1531 | { | |
1532 | if (EDGE_FREQUENCY (e) < highest_freq) | |
1533 | continue; | |
1534 | } | |
1535 | else if (e->probability < highest_probability) | |
1536 | continue; | |
1537 | ||
1538 | basic_block reach_bb = walk_up ? e->src : e->dest; | |
1539 | ||
1540 | /* We have a hot bb with an immediate dominator that is cold. | |
1541 | The dominator needs to be re-marked hot. */ | |
1542 | BB_SET_PARTITION (reach_bb, BB_HOT_PARTITION); | |
1543 | cold_bb_count--; | |
1544 | ||
1545 | /* Now we need to examine newly-hot reach_bb to see if it is also | |
1546 | dominated by a cold bb. */ | |
1547 | bbs_in_hot_partition->safe_push (reach_bb); | |
1548 | hot_bbs_to_check.safe_push (reach_bb); | |
1549 | } | |
1550 | } | |
1551 | ||
1552 | return cold_bb_count; | |
1553 | } | |
1554 | ||
1555 | ||
750054a2 CT |
1556 | /* Find the basic blocks that are rarely executed and need to be moved to |
1557 | a separate section of the .o file (to cut down on paging and improve | |
ea6136a2 | 1558 | cache locality). Return a vector of all edges that cross. */ |
750054a2 | 1559 | |
600b5b1d | 1560 | static vec<edge> |
ea6136a2 | 1561 | find_rarely_executed_basic_blocks_and_crossing_edges (void) |
750054a2 | 1562 | { |
6e1aa848 | 1563 | vec<edge> crossing_edges = vNULL; |
750054a2 CT |
1564 | basic_block bb; |
1565 | edge e; | |
628f6a4e | 1566 | edge_iterator ei; |
600b5b1d | 1567 | unsigned int cold_bb_count = 0; |
548296b0 | 1568 | auto_vec<basic_block> bbs_in_hot_partition; |
750054a2 CT |
1569 | |
1570 | /* Mark which partition (hot/cold) each basic block belongs in. */ | |
11cd3bed | 1571 | FOR_EACH_BB_FN (bb, cfun) |
750054a2 | 1572 | { |
79221839 TJ |
1573 | bool cold_bb = false; |
1574 | ||
2eb712b4 | 1575 | if (probably_never_executed_bb_p (cfun, bb)) |
79221839 TJ |
1576 | { |
1577 | /* Handle profile insanities created by upstream optimizations | |
1578 | by also checking the incoming edge weights. If there is a non-cold | |
1579 | incoming edge, conservatively prevent this block from being split | |
1580 | into the cold section. */ | |
1581 | cold_bb = true; | |
1582 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1583 | if (!probably_never_executed_edge_p (cfun, e)) | |
1584 | { | |
1585 | cold_bb = false; | |
1586 | break; | |
1587 | } | |
1588 | } | |
1589 | if (cold_bb) | |
600b5b1d TJ |
1590 | { |
1591 | BB_SET_PARTITION (bb, BB_COLD_PARTITION); | |
1592 | cold_bb_count++; | |
1593 | } | |
750054a2 | 1594 | else |
600b5b1d TJ |
1595 | { |
1596 | BB_SET_PARTITION (bb, BB_HOT_PARTITION); | |
1597 | bbs_in_hot_partition.safe_push (bb); | |
1598 | } | |
1599 | } | |
1600 | ||
1601 | /* Ensure that hot bbs are included along a hot path from the entry to exit. | |
1602 | Several different possibilities may include cold bbs along all paths | |
1603 | to/from a hot bb. One is that there are edge weight insanities | |
1604 | due to optimization phases that do not properly update basic block profile | |
1605 | counts. The second is that the entry of the function may not be hot, because | |
1606 | it is entered fewer times than the number of profile training runs, but there | |
1607 | is a loop inside the function that causes blocks within the function to be | |
1608 | above the threshold for hotness. This is fixed by walking up from hot bbs | |
1609 | to the entry block, and then down from hot bbs to the exit, performing | |
1610 | partitioning fixups as necessary. */ | |
1611 | if (cold_bb_count) | |
1612 | { | |
1613 | mark_dfs_back_edges (); | |
1614 | cold_bb_count = sanitize_hot_paths (true, cold_bb_count, | |
1615 | &bbs_in_hot_partition); | |
1616 | if (cold_bb_count) | |
1617 | sanitize_hot_paths (false, cold_bb_count, &bbs_in_hot_partition); | |
750054a2 CT |
1618 | } |
1619 | ||
0be7e7a6 RH |
1620 | /* The format of .gcc_except_table does not allow landing pads to |
1621 | be in a different partition as the throw. Fix this by either | |
1622 | moving or duplicating the landing pads. */ | |
1623 | if (cfun->eh->lp_array) | |
9fb32434 | 1624 | { |
0be7e7a6 RH |
1625 | unsigned i; |
1626 | eh_landing_pad lp; | |
1627 | ||
9771b263 | 1628 | FOR_EACH_VEC_ELT (*cfun->eh->lp_array, i, lp) |
c7466dee | 1629 | { |
0be7e7a6 RH |
1630 | bool all_same, all_diff; |
1631 | ||
b58d3391 JJ |
1632 | if (lp == NULL |
1633 | || lp->landing_pad == NULL_RTX | |
1634 | || !LABEL_P (lp->landing_pad)) | |
0be7e7a6 RH |
1635 | continue; |
1636 | ||
1637 | all_same = all_diff = true; | |
1638 | bb = BLOCK_FOR_INSN (lp->landing_pad); | |
1639 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1640 | { | |
1641 | gcc_assert (e->flags & EDGE_EH); | |
1642 | if (BB_PARTITION (bb) == BB_PARTITION (e->src)) | |
1643 | all_diff = false; | |
1644 | else | |
1645 | all_same = false; | |
1646 | } | |
1647 | ||
1648 | if (all_same) | |
1649 | ; | |
1650 | else if (all_diff) | |
1651 | { | |
1652 | int which = BB_PARTITION (bb); | |
1653 | which ^= BB_HOT_PARTITION | BB_COLD_PARTITION; | |
1654 | BB_SET_PARTITION (bb, which); | |
1655 | } | |
1656 | else | |
1657 | fix_up_crossing_landing_pad (lp, bb); | |
c7466dee | 1658 | } |
9fb32434 | 1659 | } |
ea6136a2 | 1660 | |
0be7e7a6 | 1661 | /* Mark every edge that crosses between sections. */ |
750054a2 | 1662 | |
11cd3bed | 1663 | FOR_EACH_BB_FN (bb, cfun) |
0be7e7a6 RH |
1664 | FOR_EACH_EDGE (e, ei, bb->succs) |
1665 | { | |
1666 | unsigned int flags = e->flags; | |
4700dd70 | 1667 | |
0be7e7a6 RH |
1668 | /* We should never have EDGE_CROSSING set yet. */ |
1669 | gcc_checking_assert ((flags & EDGE_CROSSING) == 0); | |
1670 | ||
fefa31b5 DM |
1671 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
1672 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
0be7e7a6 RH |
1673 | && BB_PARTITION (e->src) != BB_PARTITION (e->dest)) |
1674 | { | |
9771b263 | 1675 | crossing_edges.safe_push (e); |
0be7e7a6 RH |
1676 | flags |= EDGE_CROSSING; |
1677 | } | |
9f68560b | 1678 | |
0be7e7a6 RH |
1679 | /* Now that we've split eh edges as appropriate, allow landing pads |
1680 | to be merged with the post-landing pads. */ | |
1681 | flags &= ~EDGE_PRESERVE; | |
1682 | ||
1683 | e->flags = flags; | |
1684 | } | |
1685 | ||
1686 | return crossing_edges; | |
9f68560b RH |
1687 | } |
1688 | ||
532aafad SB |
1689 | /* Set the flag EDGE_CAN_FALLTHRU for edges that can be fallthru. */ |
1690 | ||
1691 | static void | |
1692 | set_edge_can_fallthru_flag (void) | |
1693 | { | |
1694 | basic_block bb; | |
1695 | ||
11cd3bed | 1696 | FOR_EACH_BB_FN (bb, cfun) |
532aafad SB |
1697 | { |
1698 | edge e; | |
1699 | edge_iterator ei; | |
1700 | ||
1701 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1702 | { | |
1703 | e->flags &= ~EDGE_CAN_FALLTHRU; | |
1704 | ||
1705 | /* The FALLTHRU edge is also CAN_FALLTHRU edge. */ | |
1706 | if (e->flags & EDGE_FALLTHRU) | |
1707 | e->flags |= EDGE_CAN_FALLTHRU; | |
1708 | } | |
1709 | ||
1710 | /* If the BB ends with an invertible condjump all (2) edges are | |
1711 | CAN_FALLTHRU edges. */ | |
1712 | if (EDGE_COUNT (bb->succs) != 2) | |
1713 | continue; | |
1714 | if (!any_condjump_p (BB_END (bb))) | |
1715 | continue; | |
1476d1bd MM |
1716 | |
1717 | rtx_jump_insn *bb_end_jump = as_a <rtx_jump_insn *> (BB_END (bb)); | |
1718 | if (!invert_jump (bb_end_jump, JUMP_LABEL (bb_end_jump), 0)) | |
532aafad | 1719 | continue; |
1476d1bd | 1720 | invert_jump (bb_end_jump, JUMP_LABEL (bb_end_jump), 0); |
532aafad SB |
1721 | EDGE_SUCC (bb, 0)->flags |= EDGE_CAN_FALLTHRU; |
1722 | EDGE_SUCC (bb, 1)->flags |= EDGE_CAN_FALLTHRU; | |
1723 | } | |
1724 | } | |
1725 | ||
750054a2 | 1726 | /* If any destination of a crossing edge does not have a label, add label; |
ea6136a2 | 1727 | Convert any easy fall-through crossing edges to unconditional jumps. */ |
750054a2 | 1728 | |
c22cacf3 | 1729 | static void |
9771b263 | 1730 | add_labels_and_missing_jumps (vec<edge> crossing_edges) |
750054a2 | 1731 | { |
ea6136a2 RH |
1732 | size_t i; |
1733 | edge e; | |
c22cacf3 | 1734 | |
9771b263 | 1735 | FOR_EACH_VEC_ELT (crossing_edges, i, e) |
750054a2 | 1736 | { |
ea6136a2 RH |
1737 | basic_block src = e->src; |
1738 | basic_block dest = e->dest; | |
e67d1102 | 1739 | rtx_jump_insn *new_jump; |
c22cacf3 | 1740 | |
fefa31b5 | 1741 | if (dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ea6136a2 | 1742 | continue; |
c22cacf3 | 1743 | |
ea6136a2 | 1744 | /* Make sure dest has a label. */ |
e67d1102 | 1745 | rtx_code_label *label = block_label (dest); |
c22cacf3 | 1746 | |
ea6136a2 | 1747 | /* Nothing to do for non-fallthru edges. */ |
fefa31b5 | 1748 | if (src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
ea6136a2 RH |
1749 | continue; |
1750 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1751 | continue; | |
c22cacf3 | 1752 | |
ea6136a2 RH |
1753 | /* If the block does not end with a control flow insn, then we |
1754 | can trivially add a jump to the end to fixup the crossing. | |
1755 | Otherwise the jump will have to go in a new bb, which will | |
1756 | be handled by fix_up_fall_thru_edges function. */ | |
1757 | if (control_flow_insn_p (BB_END (src))) | |
1758 | continue; | |
1759 | ||
1760 | /* Make sure there's only one successor. */ | |
1761 | gcc_assert (single_succ_p (src)); | |
1762 | ||
ec4a505f | 1763 | new_jump = emit_jump_insn_after (targetm.gen_jump (label), BB_END (src)); |
1130d5e3 | 1764 | BB_END (src) = new_jump; |
ea6136a2 RH |
1765 | JUMP_LABEL (new_jump) = label; |
1766 | LABEL_NUSES (label) += 1; | |
9f68560b RH |
1767 | |
1768 | emit_barrier_after_bb (src); | |
ea6136a2 RH |
1769 | |
1770 | /* Mark edge as non-fallthru. */ | |
1771 | e->flags &= ~EDGE_FALLTHRU; | |
1772 | } | |
750054a2 CT |
1773 | } |
1774 | ||
1775 | /* Find any bb's where the fall-through edge is a crossing edge (note that | |
8bf6e270 RE |
1776 | these bb's must also contain a conditional jump or end with a call |
1777 | instruction; we've already dealt with fall-through edges for blocks | |
1778 | that didn't have a conditional jump or didn't end with call instruction | |
1779 | in the call to add_labels_and_missing_jumps). Convert the fall-through | |
1780 | edge to non-crossing edge by inserting a new bb to fall-through into. | |
1781 | The new bb will contain an unconditional jump (crossing edge) to the | |
1782 | original fall through destination. */ | |
750054a2 | 1783 | |
c22cacf3 | 1784 | static void |
750054a2 CT |
1785 | fix_up_fall_thru_edges (void) |
1786 | { | |
1787 | basic_block cur_bb; | |
1788 | basic_block new_bb; | |
1789 | edge succ1; | |
1790 | edge succ2; | |
1791 | edge fall_thru; | |
4b493aa5 | 1792 | edge cond_jump = NULL; |
750054a2 CT |
1793 | bool cond_jump_crosses; |
1794 | int invert_worked; | |
e93768e4 | 1795 | rtx_insn *old_jump; |
e67d1102 | 1796 | rtx_code_label *fall_thru_label; |
c22cacf3 | 1797 | |
11cd3bed | 1798 | FOR_EACH_BB_FN (cur_bb, cfun) |
750054a2 CT |
1799 | { |
1800 | fall_thru = NULL; | |
628f6a4e BE |
1801 | if (EDGE_COUNT (cur_bb->succs) > 0) |
1802 | succ1 = EDGE_SUCC (cur_bb, 0); | |
1803 | else | |
1804 | succ1 = NULL; | |
1805 | ||
1806 | if (EDGE_COUNT (cur_bb->succs) > 1) | |
c22cacf3 | 1807 | succ2 = EDGE_SUCC (cur_bb, 1); |
750054a2 | 1808 | else |
c22cacf3 MS |
1809 | succ2 = NULL; |
1810 | ||
750054a2 | 1811 | /* Find the fall-through edge. */ |
c22cacf3 MS |
1812 | |
1813 | if (succ1 | |
1814 | && (succ1->flags & EDGE_FALLTHRU)) | |
1815 | { | |
1816 | fall_thru = succ1; | |
1817 | cond_jump = succ2; | |
1818 | } | |
1819 | else if (succ2 | |
1820 | && (succ2->flags & EDGE_FALLTHRU)) | |
1821 | { | |
1822 | fall_thru = succ2; | |
1823 | cond_jump = succ1; | |
1824 | } | |
596aa3f0 JJ |
1825 | else if (succ1 |
1826 | && (block_ends_with_call_p (cur_bb) | |
1827 | || can_throw_internal (BB_END (cur_bb)))) | |
1828 | { | |
1829 | edge e; | |
1830 | edge_iterator ei; | |
1831 | ||
596aa3f0 | 1832 | FOR_EACH_EDGE (e, ei, cur_bb->succs) |
f87604f8 | 1833 | if (e->flags & EDGE_FALLTHRU) |
596aa3f0 JJ |
1834 | { |
1835 | fall_thru = e; | |
1836 | break; | |
1837 | } | |
1838 | } | |
c22cacf3 | 1839 | |
fefa31b5 | 1840 | if (fall_thru && (fall_thru->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))) |
c22cacf3 MS |
1841 | { |
1842 | /* Check to see if the fall-thru edge is a crossing edge. */ | |
1843 | ||
bd454efd | 1844 | if (fall_thru->flags & EDGE_CROSSING) |
c22cacf3 | 1845 | { |
750054a2 | 1846 | /* The fall_thru edge crosses; now check the cond jump edge, if |
c22cacf3 MS |
1847 | it exists. */ |
1848 | ||
1849 | cond_jump_crosses = true; | |
1850 | invert_worked = 0; | |
750054a2 | 1851 | old_jump = BB_END (cur_bb); |
c22cacf3 MS |
1852 | |
1853 | /* Find the jump instruction, if there is one. */ | |
1854 | ||
1855 | if (cond_jump) | |
1856 | { | |
bd454efd | 1857 | if (!(cond_jump->flags & EDGE_CROSSING)) |
c22cacf3 MS |
1858 | cond_jump_crosses = false; |
1859 | ||
1860 | /* We know the fall-thru edge crosses; if the cond | |
1861 | jump edge does NOT cross, and its destination is the | |
750054a2 | 1862 | next block in the bb order, invert the jump |
073a8998 | 1863 | (i.e. fix it so the fall through does not cross and |
c22cacf3 MS |
1864 | the cond jump does). */ |
1865 | ||
3371a64f | 1866 | if (!cond_jump_crosses) |
c22cacf3 MS |
1867 | { |
1868 | /* Find label in fall_thru block. We've already added | |
1869 | any missing labels, so there must be one. */ | |
1870 | ||
1871 | fall_thru_label = block_label (fall_thru->dest); | |
1872 | ||
1476d1bd MM |
1873 | if (old_jump && fall_thru_label) |
1874 | { | |
1875 | rtx_jump_insn *old_jump_insn = | |
1876 | dyn_cast <rtx_jump_insn *> (old_jump); | |
1877 | if (old_jump_insn) | |
1878 | invert_worked = invert_jump (old_jump_insn, | |
1879 | fall_thru_label, 0); | |
1880 | } | |
1881 | ||
c22cacf3 MS |
1882 | if (invert_worked) |
1883 | { | |
1884 | fall_thru->flags &= ~EDGE_FALLTHRU; | |
1885 | cond_jump->flags |= EDGE_FALLTHRU; | |
1886 | update_br_prob_note (cur_bb); | |
fab27f52 | 1887 | std::swap (fall_thru, cond_jump); |
bd454efd SB |
1888 | cond_jump->flags |= EDGE_CROSSING; |
1889 | fall_thru->flags &= ~EDGE_CROSSING; | |
c22cacf3 MS |
1890 | } |
1891 | } | |
1892 | } | |
1893 | ||
1894 | if (cond_jump_crosses || !invert_worked) | |
1895 | { | |
1896 | /* This is the case where both edges out of the basic | |
1897 | block are crossing edges. Here we will fix up the | |
750054a2 | 1898 | fall through edge. The jump edge will be taken care |
b8698a0f | 1899 | of later. The EDGE_CROSSING flag of fall_thru edge |
4700dd70 EB |
1900 | is unset before the call to force_nonfallthru |
1901 | function because if a new basic-block is created | |
1902 | this edge remains in the current section boundary | |
1903 | while the edge between new_bb and the fall_thru->dest | |
1904 | becomes EDGE_CROSSING. */ | |
8bf6e270 | 1905 | |
4700dd70 | 1906 | fall_thru->flags &= ~EDGE_CROSSING; |
c22cacf3 MS |
1907 | new_bb = force_nonfallthru (fall_thru); |
1908 | ||
1909 | if (new_bb) | |
1910 | { | |
1911 | new_bb->aux = cur_bb->aux; | |
1912 | cur_bb->aux = new_bb; | |
1913 | ||
3371a64f TJ |
1914 | /* This is done by force_nonfallthru_and_redirect. */ |
1915 | gcc_assert (BB_PARTITION (new_bb) | |
1916 | == BB_PARTITION (cur_bb)); | |
076c7ab8 | 1917 | |
c5cbcccf | 1918 | single_succ_edge (new_bb)->flags |= EDGE_CROSSING; |
c22cacf3 | 1919 | } |
4700dd70 EB |
1920 | else |
1921 | { | |
1922 | /* If a new basic-block was not created; restore | |
1923 | the EDGE_CROSSING flag. */ | |
1924 | fall_thru->flags |= EDGE_CROSSING; | |
1925 | } | |
c22cacf3 MS |
1926 | |
1927 | /* Add barrier after new jump */ | |
9f68560b | 1928 | emit_barrier_after_bb (new_bb ? new_bb : cur_bb); |
c22cacf3 MS |
1929 | } |
1930 | } | |
1931 | } | |
750054a2 CT |
1932 | } |
1933 | } | |
1934 | ||
fa10beec | 1935 | /* This function checks the destination block of a "crossing jump" to |
750054a2 CT |
1936 | see if it has any crossing predecessors that begin with a code label |
1937 | and end with an unconditional jump. If so, it returns that predecessor | |
1938 | block. (This is to avoid creating lots of new basic blocks that all | |
1939 | contain unconditional jumps to the same destination). */ | |
1940 | ||
1941 | static basic_block | |
c22cacf3 MS |
1942 | find_jump_block (basic_block jump_dest) |
1943 | { | |
1944 | basic_block source_bb = NULL; | |
750054a2 | 1945 | edge e; |
e93768e4 | 1946 | rtx_insn *insn; |
628f6a4e | 1947 | edge_iterator ei; |
750054a2 | 1948 | |
628f6a4e | 1949 | FOR_EACH_EDGE (e, ei, jump_dest->preds) |
bd454efd | 1950 | if (e->flags & EDGE_CROSSING) |
750054a2 CT |
1951 | { |
1952 | basic_block src = e->src; | |
c22cacf3 | 1953 | |
750054a2 CT |
1954 | /* Check each predecessor to see if it has a label, and contains |
1955 | only one executable instruction, which is an unconditional jump. | |
9cf737f8 | 1956 | If so, we can use it. */ |
c22cacf3 | 1957 | |
4b4bf941 | 1958 | if (LABEL_P (BB_HEAD (src))) |
c22cacf3 | 1959 | for (insn = BB_HEAD (src); |
750054a2 CT |
1960 | !INSN_P (insn) && insn != NEXT_INSN (BB_END (src)); |
1961 | insn = NEXT_INSN (insn)) | |
1962 | { | |
1963 | if (INSN_P (insn) | |
1964 | && insn == BB_END (src) | |
4b4bf941 | 1965 | && JUMP_P (insn) |
750054a2 CT |
1966 | && !any_condjump_p (insn)) |
1967 | { | |
1968 | source_bb = src; | |
1969 | break; | |
1970 | } | |
1971 | } | |
c22cacf3 | 1972 | |
750054a2 CT |
1973 | if (source_bb) |
1974 | break; | |
1975 | } | |
1976 | ||
1977 | return source_bb; | |
1978 | } | |
1979 | ||
1980 | /* Find all BB's with conditional jumps that are crossing edges; | |
1981 | insert a new bb and make the conditional jump branch to the new | |
1982 | bb instead (make the new bb same color so conditional branch won't | |
1983 | be a 'crossing' edge). Insert an unconditional jump from the | |
1984 | new bb to the original destination of the conditional jump. */ | |
1985 | ||
1986 | static void | |
1987 | fix_crossing_conditional_branches (void) | |
1988 | { | |
1989 | basic_block cur_bb; | |
1990 | basic_block new_bb; | |
750054a2 | 1991 | basic_block dest; |
750054a2 CT |
1992 | edge succ1; |
1993 | edge succ2; | |
1994 | edge crossing_edge; | |
1995 | edge new_edge; | |
750054a2 CT |
1996 | rtx set_src; |
1997 | rtx old_label = NULL_RTX; | |
1476d1bd | 1998 | rtx_code_label *new_label; |
c22cacf3 | 1999 | |
11cd3bed | 2000 | FOR_EACH_BB_FN (cur_bb, cfun) |
750054a2 CT |
2001 | { |
2002 | crossing_edge = NULL; | |
628f6a4e BE |
2003 | if (EDGE_COUNT (cur_bb->succs) > 0) |
2004 | succ1 = EDGE_SUCC (cur_bb, 0); | |
2005 | else | |
2006 | succ1 = NULL; | |
c22cacf3 | 2007 | |
628f6a4e BE |
2008 | if (EDGE_COUNT (cur_bb->succs) > 1) |
2009 | succ2 = EDGE_SUCC (cur_bb, 1); | |
750054a2 | 2010 | else |
628f6a4e | 2011 | succ2 = NULL; |
c22cacf3 | 2012 | |
750054a2 CT |
2013 | /* We already took care of fall-through edges, so only one successor |
2014 | can be a crossing edge. */ | |
c22cacf3 | 2015 | |
bd454efd | 2016 | if (succ1 && (succ1->flags & EDGE_CROSSING)) |
750054a2 | 2017 | crossing_edge = succ1; |
bd454efd | 2018 | else if (succ2 && (succ2->flags & EDGE_CROSSING)) |
c22cacf3 MS |
2019 | crossing_edge = succ2; |
2020 | ||
2021 | if (crossing_edge) | |
2022 | { | |
d08093db | 2023 | rtx_insn *old_jump = BB_END (cur_bb); |
c22cacf3 | 2024 | |
750054a2 CT |
2025 | /* Check to make sure the jump instruction is a |
2026 | conditional jump. */ | |
c22cacf3 | 2027 | |
750054a2 CT |
2028 | set_src = NULL_RTX; |
2029 | ||
2030 | if (any_condjump_p (old_jump)) | |
2031 | { | |
2032 | if (GET_CODE (PATTERN (old_jump)) == SET) | |
2033 | set_src = SET_SRC (PATTERN (old_jump)); | |
2034 | else if (GET_CODE (PATTERN (old_jump)) == PARALLEL) | |
2035 | { | |
2036 | set_src = XVECEXP (PATTERN (old_jump), 0,0); | |
2037 | if (GET_CODE (set_src) == SET) | |
2038 | set_src = SET_SRC (set_src); | |
2039 | else | |
2040 | set_src = NULL_RTX; | |
2041 | } | |
2042 | } | |
2043 | ||
2044 | if (set_src && (GET_CODE (set_src) == IF_THEN_ELSE)) | |
2045 | { | |
d08093db MM |
2046 | rtx_jump_insn *old_jump_insn = |
2047 | as_a <rtx_jump_insn *> (old_jump); | |
2048 | ||
750054a2 CT |
2049 | if (GET_CODE (XEXP (set_src, 1)) == PC) |
2050 | old_label = XEXP (set_src, 2); | |
2051 | else if (GET_CODE (XEXP (set_src, 2)) == PC) | |
2052 | old_label = XEXP (set_src, 1); | |
c22cacf3 | 2053 | |
750054a2 CT |
2054 | /* Check to see if new bb for jumping to that dest has |
2055 | already been created; if so, use it; if not, create | |
2056 | a new one. */ | |
2057 | ||
2058 | new_bb = find_jump_block (crossing_edge->dest); | |
c22cacf3 | 2059 | |
750054a2 CT |
2060 | if (new_bb) |
2061 | new_label = block_label (new_bb); | |
2062 | else | |
2063 | { | |
6774a66f | 2064 | basic_block last_bb; |
1476d1bd MM |
2065 | rtx_code_label *old_jump_target; |
2066 | rtx_jump_insn *new_jump; | |
6774a66f | 2067 | |
750054a2 CT |
2068 | /* Create new basic block to be dest for |
2069 | conditional jump. */ | |
c22cacf3 | 2070 | |
750054a2 | 2071 | /* Put appropriate instructions in new bb. */ |
c22cacf3 | 2072 | |
750054a2 | 2073 | new_label = gen_label_rtx (); |
6774a66f | 2074 | emit_label (new_label); |
c22cacf3 | 2075 | |
6774a66f | 2076 | gcc_assert (GET_CODE (old_label) == LABEL_REF); |
d08093db | 2077 | old_jump_target = old_jump_insn->jump_target (); |
1476d1bd | 2078 | new_jump = as_a <rtx_jump_insn *> |
ec4a505f | 2079 | (emit_jump_insn (targetm.gen_jump (old_jump_target))); |
1476d1bd | 2080 | new_jump->set_jump_target (old_jump_target); |
6774a66f | 2081 | |
fefa31b5 | 2082 | last_bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb; |
6774a66f RH |
2083 | new_bb = create_basic_block (new_label, new_jump, last_bb); |
2084 | new_bb->aux = last_bb->aux; | |
2085 | last_bb->aux = new_bb; | |
9f68560b RH |
2086 | |
2087 | emit_barrier_after_bb (new_bb); | |
c22cacf3 | 2088 | |
750054a2 CT |
2089 | /* Make sure new bb is in same partition as source |
2090 | of conditional branch. */ | |
076c7ab8 | 2091 | BB_COPY_PARTITION (new_bb, cur_bb); |
750054a2 | 2092 | } |
c22cacf3 | 2093 | |
750054a2 | 2094 | /* Make old jump branch to new bb. */ |
c22cacf3 | 2095 | |
d08093db | 2096 | redirect_jump (old_jump_insn, new_label, 0); |
c22cacf3 | 2097 | |
750054a2 | 2098 | /* Remove crossing_edge as predecessor of 'dest'. */ |
c22cacf3 | 2099 | |
750054a2 | 2100 | dest = crossing_edge->dest; |
c22cacf3 | 2101 | |
750054a2 | 2102 | redirect_edge_succ (crossing_edge, new_bb); |
c22cacf3 | 2103 | |
750054a2 CT |
2104 | /* Make a new edge from new_bb to old dest; new edge |
2105 | will be a successor for new_bb and a predecessor | |
2106 | for 'dest'. */ | |
c22cacf3 | 2107 | |
628f6a4e | 2108 | if (EDGE_COUNT (new_bb->succs) == 0) |
750054a2 CT |
2109 | new_edge = make_edge (new_bb, dest, 0); |
2110 | else | |
628f6a4e | 2111 | new_edge = EDGE_SUCC (new_bb, 0); |
c22cacf3 | 2112 | |
bd454efd SB |
2113 | crossing_edge->flags &= ~EDGE_CROSSING; |
2114 | new_edge->flags |= EDGE_CROSSING; | |
750054a2 | 2115 | } |
c22cacf3 | 2116 | } |
750054a2 CT |
2117 | } |
2118 | } | |
2119 | ||
2120 | /* Find any unconditional branches that cross between hot and cold | |
2121 | sections. Convert them into indirect jumps instead. */ | |
2122 | ||
2123 | static void | |
2124 | fix_crossing_unconditional_branches (void) | |
2125 | { | |
2126 | basic_block cur_bb; | |
e93768e4 | 2127 | rtx_insn *last_insn; |
750054a2 CT |
2128 | rtx label; |
2129 | rtx label_addr; | |
e93768e4 DM |
2130 | rtx_insn *indirect_jump_sequence; |
2131 | rtx_insn *jump_insn = NULL; | |
750054a2 | 2132 | rtx new_reg; |
e93768e4 | 2133 | rtx_insn *cur_insn; |
750054a2 | 2134 | edge succ; |
9fb32434 | 2135 | |
11cd3bed | 2136 | FOR_EACH_BB_FN (cur_bb, cfun) |
750054a2 CT |
2137 | { |
2138 | last_insn = BB_END (cur_bb); | |
87c8b4be CT |
2139 | |
2140 | if (EDGE_COUNT (cur_bb->succs) < 1) | |
2141 | continue; | |
2142 | ||
628f6a4e | 2143 | succ = EDGE_SUCC (cur_bb, 0); |
750054a2 CT |
2144 | |
2145 | /* Check to see if bb ends in a crossing (unconditional) jump. At | |
c22cacf3 | 2146 | this point, no crossing jumps should be conditional. */ |
750054a2 | 2147 | |
4b4bf941 | 2148 | if (JUMP_P (last_insn) |
bd454efd | 2149 | && (succ->flags & EDGE_CROSSING)) |
750054a2 | 2150 | { |
298e6adc | 2151 | gcc_assert (!any_condjump_p (last_insn)); |
750054a2 CT |
2152 | |
2153 | /* Make sure the jump is not already an indirect or table jump. */ | |
2154 | ||
298e6adc | 2155 | if (!computed_jump_p (last_insn) |
7bca81dc | 2156 | && !tablejump_p (last_insn, NULL, NULL)) |
750054a2 CT |
2157 | { |
2158 | /* We have found a "crossing" unconditional branch. Now | |
2159 | we must convert it to an indirect jump. First create | |
2160 | reference of label, as target for jump. */ | |
c22cacf3 | 2161 | |
750054a2 | 2162 | label = JUMP_LABEL (last_insn); |
b50b729d | 2163 | label_addr = gen_rtx_LABEL_REF (Pmode, label); |
750054a2 | 2164 | LABEL_NUSES (label) += 1; |
c22cacf3 | 2165 | |
750054a2 | 2166 | /* Get a register to use for the indirect jump. */ |
c22cacf3 | 2167 | |
750054a2 | 2168 | new_reg = gen_reg_rtx (Pmode); |
c22cacf3 | 2169 | |
750054a2 | 2170 | /* Generate indirect the jump sequence. */ |
c22cacf3 | 2171 | |
750054a2 CT |
2172 | start_sequence (); |
2173 | emit_move_insn (new_reg, label_addr); | |
2174 | emit_indirect_jump (new_reg); | |
2175 | indirect_jump_sequence = get_insns (); | |
2176 | end_sequence (); | |
c22cacf3 | 2177 | |
750054a2 CT |
2178 | /* Make sure every instruction in the new jump sequence has |
2179 | its basic block set to be cur_bb. */ | |
c22cacf3 | 2180 | |
750054a2 CT |
2181 | for (cur_insn = indirect_jump_sequence; cur_insn; |
2182 | cur_insn = NEXT_INSN (cur_insn)) | |
2183 | { | |
0e714a54 EB |
2184 | if (!BARRIER_P (cur_insn)) |
2185 | BLOCK_FOR_INSN (cur_insn) = cur_bb; | |
4b4bf941 | 2186 | if (JUMP_P (cur_insn)) |
750054a2 CT |
2187 | jump_insn = cur_insn; |
2188 | } | |
c22cacf3 | 2189 | |
750054a2 CT |
2190 | /* Insert the new (indirect) jump sequence immediately before |
2191 | the unconditional jump, then delete the unconditional jump. */ | |
c22cacf3 | 2192 | |
750054a2 CT |
2193 | emit_insn_before (indirect_jump_sequence, last_insn); |
2194 | delete_insn (last_insn); | |
c22cacf3 | 2195 | |
8fce217e JJ |
2196 | JUMP_LABEL (jump_insn) = label; |
2197 | LABEL_NUSES (label)++; | |
2198 | ||
750054a2 CT |
2199 | /* Make BB_END for cur_bb be the jump instruction (NOT the |
2200 | barrier instruction at the end of the sequence...). */ | |
c22cacf3 | 2201 | |
1130d5e3 | 2202 | BB_END (cur_bb) = jump_insn; |
750054a2 CT |
2203 | } |
2204 | } | |
2205 | } | |
2206 | } | |
2207 | ||
339ba33b | 2208 | /* Update CROSSING_JUMP_P flags on all jump insns. */ |
750054a2 CT |
2209 | |
2210 | static void | |
339ba33b | 2211 | update_crossing_jump_flags (void) |
750054a2 CT |
2212 | { |
2213 | basic_block bb; | |
2214 | edge e; | |
628f6a4e | 2215 | edge_iterator ei; |
750054a2 | 2216 | |
11cd3bed | 2217 | FOR_EACH_BB_FN (bb, cfun) |
628f6a4e | 2218 | FOR_EACH_EDGE (e, ei, bb->succs) |
339ba33b RS |
2219 | if (e->flags & EDGE_CROSSING) |
2220 | { | |
2221 | if (JUMP_P (BB_END (bb)) | |
2222 | /* Some flags were added during fix_up_fall_thru_edges, via | |
2223 | force_nonfallthru_and_redirect. */ | |
2224 | && !CROSSING_JUMP_P (BB_END (bb))) | |
2225 | CROSSING_JUMP_P (BB_END (bb)) = 1; | |
2226 | break; | |
2227 | } | |
750054a2 CT |
2228 | } |
2229 | ||
af71fa39 | 2230 | /* Reorder basic blocks using the software trace cache (STC) algorithm. */ |
295ae817 | 2231 | |
711417cd | 2232 | static void |
af71fa39 | 2233 | reorder_basic_blocks_software_trace_cache (void) |
295ae817 | 2234 | { |
248c16c4 SB |
2235 | if (dump_file) |
2236 | fprintf (dump_file, "\nReordering with the STC algorithm.\n\n"); | |
2237 | ||
aa634f11 JZ |
2238 | int n_traces; |
2239 | int i; | |
2240 | struct trace *traces; | |
2241 | ||
e0bb17a8 KH |
2242 | /* We are estimating the length of uncond jump insn only once since the code |
2243 | for getting the insn length always returns the minimal length now. */ | |
4682ae04 | 2244 | if (uncond_jump_length == 0) |
aa634f11 JZ |
2245 | uncond_jump_length = get_uncond_jump_length (); |
2246 | ||
2247 | /* We need to know some information for each basic block. */ | |
8b1c6fd7 | 2248 | array_size = GET_ARRAY_SIZE (last_basic_block_for_fn (cfun)); |
5ed6ace5 | 2249 | bbd = XNEWVEC (bbro_basic_block_data, array_size); |
aa634f11 JZ |
2250 | for (i = 0; i < array_size; i++) |
2251 | { | |
2252 | bbd[i].start_of_trace = -1; | |
2253 | bbd[i].end_of_trace = -1; | |
bcc708fc MM |
2254 | bbd[i].in_trace = -1; |
2255 | bbd[i].visited = 0; | |
aa634f11 JZ |
2256 | bbd[i].heap = NULL; |
2257 | bbd[i].node = NULL; | |
2258 | } | |
2259 | ||
0cae8d31 | 2260 | traces = XNEWVEC (struct trace, n_basic_blocks_for_fn (cfun)); |
aa634f11 JZ |
2261 | n_traces = 0; |
2262 | find_traces (&n_traces, traces); | |
2263 | connect_traces (n_traces, traces); | |
2264 | FREE (traces); | |
2265 | FREE (bbd); | |
af71fa39 SB |
2266 | } |
2267 | ||
248c16c4 SB |
2268 | /* Return true if edge E1 is more desirable as a fallthrough edge than |
2269 | edge E2 is. */ | |
2270 | ||
2271 | static bool | |
2272 | edge_order (edge e1, edge e2) | |
2273 | { | |
2274 | return EDGE_FREQUENCY (e1) > EDGE_FREQUENCY (e2); | |
2275 | } | |
2276 | ||
2277 | /* Reorder basic blocks using the "simple" algorithm. This tries to | |
2278 | maximize the dynamic number of branches that are fallthrough, without | |
2279 | copying instructions. The algorithm is greedy, looking at the most | |
2280 | frequently executed branch first. */ | |
2281 | ||
2282 | static void | |
2283 | reorder_basic_blocks_simple (void) | |
2284 | { | |
2285 | if (dump_file) | |
2286 | fprintf (dump_file, "\nReordering with the \"simple\" algorithm.\n\n"); | |
2287 | ||
2288 | edge *edges = new edge[2 * n_basic_blocks_for_fn (cfun)]; | |
2289 | ||
2290 | /* First, collect all edges that can be optimized by reordering blocks: | |
2291 | simple jumps and conditional jumps, as well as the function entry edge. */ | |
2292 | ||
2293 | int n = 0; | |
2294 | edges[n++] = EDGE_SUCC (ENTRY_BLOCK_PTR_FOR_FN (cfun), 0); | |
2295 | ||
2296 | basic_block bb; | |
2297 | FOR_EACH_BB_FN (bb, cfun) | |
2298 | { | |
2299 | rtx_insn *end = BB_END (bb); | |
2300 | ||
2301 | if (computed_jump_p (end) || tablejump_p (end, NULL, NULL)) | |
2302 | continue; | |
2303 | ||
2304 | /* We cannot optimize asm goto. */ | |
2305 | if (JUMP_P (end) && extract_asm_operands (end)) | |
2306 | continue; | |
2307 | ||
d4c8d5ed SB |
2308 | if (single_succ_p (bb)) |
2309 | edges[n++] = EDGE_SUCC (bb, 0); | |
2310 | else if (any_condjump_p (end)) | |
248c16c4 | 2311 | { |
c70f0ca2 SB |
2312 | edge e0 = EDGE_SUCC (bb, 0); |
2313 | edge e1 = EDGE_SUCC (bb, 1); | |
2314 | /* When optimizing for size it is best to keep the original | |
2315 | fallthrough edges. */ | |
2316 | if (e1->flags & EDGE_FALLTHRU) | |
2317 | std::swap (e0, e1); | |
2318 | edges[n++] = e0; | |
2319 | edges[n++] = e1; | |
248c16c4 | 2320 | } |
248c16c4 SB |
2321 | } |
2322 | ||
c70f0ca2 SB |
2323 | /* Sort the edges, the most desirable first. When optimizing for size |
2324 | all edges are equally desirable. */ | |
248c16c4 | 2325 | |
c70f0ca2 SB |
2326 | if (optimize_function_for_speed_p (cfun)) |
2327 | std::stable_sort (edges, edges + n, edge_order); | |
248c16c4 SB |
2328 | |
2329 | /* Now decide which of those edges to make fallthrough edges. We set | |
2330 | BB_VISITED if a block already has a fallthrough successor assigned | |
2331 | to it. We make ->AUX of an endpoint point to the opposite endpoint | |
2332 | of a sequence of blocks that fall through, and ->AUX will be NULL | |
2333 | for a block that is in such a sequence but not an endpoint anymore. | |
2334 | ||
2335 | To start with, everything points to itself, nothing is assigned yet. */ | |
2336 | ||
2337 | FOR_ALL_BB_FN (bb, cfun) | |
2338 | bb->aux = bb; | |
2339 | ||
2340 | EXIT_BLOCK_PTR_FOR_FN (cfun)->aux = 0; | |
2341 | ||
2342 | /* Now for all edges, the most desirable first, see if that edge can | |
2343 | connect two sequences. If it can, update AUX and BB_VISITED; if it | |
2344 | cannot, zero out the edge in the table. */ | |
2345 | ||
2346 | for (int j = 0; j < n; j++) | |
2347 | { | |
2348 | edge e = edges[j]; | |
2349 | ||
2350 | basic_block tail_a = e->src; | |
2351 | basic_block head_b = e->dest; | |
2352 | basic_block head_a = (basic_block) tail_a->aux; | |
2353 | basic_block tail_b = (basic_block) head_b->aux; | |
2354 | ||
2355 | /* An edge cannot connect two sequences if: | |
2356 | - it crosses partitions; | |
2357 | - its src is not a current endpoint; | |
2358 | - its dest is not a current endpoint; | |
2359 | - or, it would create a loop. */ | |
2360 | ||
2361 | if (e->flags & EDGE_CROSSING | |
2362 | || tail_a->flags & BB_VISITED | |
2363 | || !tail_b | |
2364 | || (!(head_b->flags & BB_VISITED) && head_b != tail_b) | |
2365 | || tail_a == tail_b) | |
2366 | { | |
2367 | edges[j] = 0; | |
2368 | continue; | |
2369 | } | |
2370 | ||
2371 | tail_a->aux = 0; | |
2372 | head_b->aux = 0; | |
2373 | head_a->aux = tail_b; | |
2374 | tail_b->aux = head_a; | |
2375 | tail_a->flags |= BB_VISITED; | |
2376 | } | |
2377 | ||
2378 | /* Put the pieces together, in the same order that the start blocks of | |
2379 | the sequences already had. The hot/cold partitioning gives a little | |
2380 | complication: as a first pass only do this for blocks in the same | |
2381 | partition as the start block, and (if there is anything left to do) | |
2382 | in a second pass handle the other partition. */ | |
2383 | ||
2384 | basic_block last_tail = (basic_block) ENTRY_BLOCK_PTR_FOR_FN (cfun)->aux; | |
2385 | ||
2386 | int current_partition = BB_PARTITION (last_tail); | |
2387 | bool need_another_pass = true; | |
2388 | ||
2389 | for (int pass = 0; pass < 2 && need_another_pass; pass++) | |
2390 | { | |
2391 | need_another_pass = false; | |
2392 | ||
2393 | FOR_EACH_BB_FN (bb, cfun) | |
2394 | if ((bb->flags & BB_VISITED && bb->aux) || bb->aux == bb) | |
2395 | { | |
2396 | if (BB_PARTITION (bb) != current_partition) | |
2397 | { | |
2398 | need_another_pass = true; | |
2399 | continue; | |
2400 | } | |
2401 | ||
2402 | last_tail->aux = bb; | |
2403 | last_tail = (basic_block) bb->aux; | |
2404 | } | |
2405 | ||
2406 | current_partition ^= BB_HOT_PARTITION | BB_COLD_PARTITION; | |
2407 | } | |
2408 | ||
2409 | last_tail->aux = 0; | |
2410 | ||
2411 | /* Finally, link all the chosen fallthrough edges. */ | |
2412 | ||
2413 | for (int j = 0; j < n; j++) | |
2414 | if (edges[j]) | |
2415 | edges[j]->src->aux = edges[j]->dest; | |
2416 | ||
2417 | delete[] edges; | |
2418 | ||
2419 | /* If the entry edge no longer falls through we have to make a new | |
2420 | block so it can do so again. */ | |
2421 | ||
2422 | edge e = EDGE_SUCC (ENTRY_BLOCK_PTR_FOR_FN (cfun), 0); | |
2423 | if (e->dest != ENTRY_BLOCK_PTR_FOR_FN (cfun)->aux) | |
2424 | { | |
2425 | force_nonfallthru (e); | |
2426 | e->src->aux = ENTRY_BLOCK_PTR_FOR_FN (cfun)->aux; | |
2427 | BB_COPY_PARTITION (e->src, e->dest); | |
2428 | } | |
2429 | } | |
2430 | ||
af71fa39 SB |
2431 | /* Reorder basic blocks. The main entry point to this file. */ |
2432 | ||
2433 | static void | |
2434 | reorder_basic_blocks (void) | |
2435 | { | |
2436 | gcc_assert (current_ir_type () == IR_RTL_CFGLAYOUT); | |
2437 | ||
2438 | if (n_basic_blocks_for_fn (cfun) <= NUM_FIXED_BLOCKS + 1) | |
2439 | return; | |
2440 | ||
2441 | set_edge_can_fallthru_flag (); | |
2442 | mark_dfs_back_edges (); | |
2443 | ||
59faab7c SB |
2444 | switch (flag_reorder_blocks_algorithm) |
2445 | { | |
2446 | case REORDER_BLOCKS_ALGORITHM_SIMPLE: | |
2447 | reorder_basic_blocks_simple (); | |
2448 | break; | |
2449 | ||
2450 | case REORDER_BLOCKS_ALGORITHM_STC: | |
2451 | reorder_basic_blocks_software_trace_cache (); | |
2452 | break; | |
2453 | ||
2454 | default: | |
2455 | gcc_unreachable (); | |
2456 | } | |
402209ff | 2457 | |
ad21dab7 SB |
2458 | relink_block_chain (/*stay_in_cfglayout_mode=*/true); |
2459 | ||
c263766c | 2460 | if (dump_file) |
532aafad SB |
2461 | { |
2462 | if (dump_flags & TDF_DETAILS) | |
2463 | dump_reg_info (dump_file); | |
2464 | dump_flow_info (dump_file, dump_flags); | |
2465 | } | |
402209ff | 2466 | |
af205f67 TJ |
2467 | /* Signal that rtl_verify_flow_info_1 can now verify that there |
2468 | is at most one switch between hot/cold sections. */ | |
2469 | crtl->bb_reorder_complete = true; | |
295ae817 | 2470 | } |
bbcb0c05 | 2471 | |
87c8b4be CT |
2472 | /* Determine which partition the first basic block in the function |
2473 | belongs to, then find the first basic block in the current function | |
2474 | that belongs to a different section, and insert a | |
2475 | NOTE_INSN_SWITCH_TEXT_SECTIONS note immediately before it in the | |
2476 | instruction stream. When writing out the assembly code, | |
2477 | encountering this note will make the compiler switch between the | |
2478 | hot and cold text sections. */ | |
2479 | ||
3371a64f | 2480 | void |
87c8b4be CT |
2481 | insert_section_boundary_note (void) |
2482 | { | |
2483 | basic_block bb; | |
3371a64f TJ |
2484 | bool switched_sections = false; |
2485 | int current_partition = 0; | |
c22cacf3 | 2486 | |
3371a64f | 2487 | if (!crtl->has_bb_partition) |
9645d434 BS |
2488 | return; |
2489 | ||
11cd3bed | 2490 | FOR_EACH_BB_FN (bb, cfun) |
87c8b4be | 2491 | { |
3371a64f TJ |
2492 | if (!current_partition) |
2493 | current_partition = BB_PARTITION (bb); | |
2494 | if (BB_PARTITION (bb) != current_partition) | |
87c8b4be | 2495 | { |
3371a64f TJ |
2496 | gcc_assert (!switched_sections); |
2497 | switched_sections = true; | |
2498 | emit_note_before (NOTE_INSN_SWITCH_TEXT_SECTIONS, BB_HEAD (bb)); | |
2499 | current_partition = BB_PARTITION (bb); | |
87c8b4be CT |
2500 | } |
2501 | } | |
2502 | } | |
2503 | ||
27a4cd48 DM |
2504 | namespace { |
2505 | ||
2506 | const pass_data pass_data_reorder_blocks = | |
427b8bb8 | 2507 | { |
27a4cd48 DM |
2508 | RTL_PASS, /* type */ |
2509 | "bbro", /* name */ | |
2510 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
2511 | TV_REORDER_BLOCKS, /* tv_id */ |
2512 | 0, /* properties_required */ | |
2513 | 0, /* properties_provided */ | |
2514 | 0, /* properties_destroyed */ | |
2515 | 0, /* todo_flags_start */ | |
3bea341f | 2516 | 0, /* todo_flags_finish */ |
427b8bb8 EB |
2517 | }; |
2518 | ||
27a4cd48 DM |
2519 | class pass_reorder_blocks : public rtl_opt_pass |
2520 | { | |
2521 | public: | |
c3284718 RS |
2522 | pass_reorder_blocks (gcc::context *ctxt) |
2523 | : rtl_opt_pass (pass_data_reorder_blocks, ctxt) | |
27a4cd48 DM |
2524 | {} |
2525 | ||
2526 | /* opt_pass methods: */ | |
1a3d085c TS |
2527 | virtual bool gate (function *) |
2528 | { | |
2529 | if (targetm.cannot_modify_jumps_p ()) | |
2530 | return false; | |
2531 | return (optimize > 0 | |
2532 | && (flag_reorder_blocks || flag_reorder_blocks_and_partition)); | |
2533 | } | |
2534 | ||
be55bfe6 | 2535 | virtual unsigned int execute (function *); |
27a4cd48 DM |
2536 | |
2537 | }; // class pass_reorder_blocks | |
2538 | ||
be55bfe6 TS |
2539 | unsigned int |
2540 | pass_reorder_blocks::execute (function *fun) | |
2541 | { | |
2542 | basic_block bb; | |
2543 | ||
2544 | /* Last attempt to optimize CFG, as scheduling, peepholing and insn | |
2545 | splitting possibly introduced more crossjumping opportunities. */ | |
2546 | cfg_layout_initialize (CLEANUP_EXPENSIVE); | |
2547 | ||
2548 | reorder_basic_blocks (); | |
2549 | cleanup_cfg (CLEANUP_EXPENSIVE); | |
2550 | ||
2551 | FOR_EACH_BB_FN (bb, fun) | |
2552 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
2553 | bb->aux = bb->next_bb; | |
2554 | cfg_layout_finalize (); | |
2555 | ||
2556 | return 0; | |
2557 | } | |
2558 | ||
27a4cd48 DM |
2559 | } // anon namespace |
2560 | ||
2561 | rtl_opt_pass * | |
2562 | make_pass_reorder_blocks (gcc::context *ctxt) | |
2563 | { | |
2564 | return new pass_reorder_blocks (ctxt); | |
2565 | } | |
2566 | ||
bbcb0c05 SB |
2567 | /* Duplicate the blocks containing computed gotos. This basically unfactors |
2568 | computed gotos that were factored early on in the compilation process to | |
2569 | speed up edge based data flow. We used to not unfactoring them again, | |
2570 | which can seriously pessimize code with many computed jumps in the source | |
2571 | code, such as interpreters. See e.g. PR15242. */ | |
2572 | ||
be55bfe6 | 2573 | namespace { |
ef330312 | 2574 | |
be55bfe6 TS |
2575 | const pass_data pass_data_duplicate_computed_gotos = |
2576 | { | |
2577 | RTL_PASS, /* type */ | |
2578 | "compgotos", /* name */ | |
2579 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
2580 | TV_REORDER_BLOCKS, /* tv_id */ |
2581 | 0, /* properties_required */ | |
2582 | 0, /* properties_provided */ | |
2583 | 0, /* properties_destroyed */ | |
2584 | 0, /* todo_flags_start */ | |
3bea341f | 2585 | 0, /* todo_flags_finish */ |
be55bfe6 TS |
2586 | }; |
2587 | ||
2588 | class pass_duplicate_computed_gotos : public rtl_opt_pass | |
2589 | { | |
2590 | public: | |
2591 | pass_duplicate_computed_gotos (gcc::context *ctxt) | |
2592 | : rtl_opt_pass (pass_data_duplicate_computed_gotos, ctxt) | |
2593 | {} | |
2594 | ||
2595 | /* opt_pass methods: */ | |
2596 | virtual bool gate (function *); | |
2597 | virtual unsigned int execute (function *); | |
2598 | ||
2599 | }; // class pass_duplicate_computed_gotos | |
2600 | ||
2601 | bool | |
2602 | pass_duplicate_computed_gotos::gate (function *fun) | |
2603 | { | |
2604 | if (targetm.cannot_modify_jumps_p ()) | |
2605 | return false; | |
2606 | return (optimize > 0 | |
2607 | && flag_expensive_optimizations | |
2608 | && ! optimize_function_for_size_p (fun)); | |
2609 | } | |
2610 | ||
2611 | unsigned int | |
2612 | pass_duplicate_computed_gotos::execute (function *fun) | |
bbcb0c05 SB |
2613 | { |
2614 | basic_block bb, new_bb; | |
2615 | bitmap candidates; | |
2616 | int max_size; | |
b55bf120 | 2617 | bool changed = false; |
bbcb0c05 | 2618 | |
be55bfe6 | 2619 | if (n_basic_blocks_for_fn (fun) <= NUM_FIXED_BLOCKS + 1) |
c2924966 | 2620 | return 0; |
bbcb0c05 | 2621 | |
bcc708fc | 2622 | clear_bb_flags (); |
bbcb0c05 SB |
2623 | cfg_layout_initialize (0); |
2624 | ||
2625 | /* We are estimating the length of uncond jump insn only once | |
2626 | since the code for getting the insn length always returns | |
2627 | the minimal length now. */ | |
2628 | if (uncond_jump_length == 0) | |
2629 | uncond_jump_length = get_uncond_jump_length (); | |
2630 | ||
4700dd70 EB |
2631 | max_size |
2632 | = uncond_jump_length * PARAM_VALUE (PARAM_MAX_GOTO_DUPLICATION_INSNS); | |
8bdbfff5 | 2633 | candidates = BITMAP_ALLOC (NULL); |
bbcb0c05 | 2634 | |
00b28cb0 SB |
2635 | /* Look for blocks that end in a computed jump, and see if such blocks |
2636 | are suitable for unfactoring. If a block is a candidate for unfactoring, | |
2637 | mark it in the candidates. */ | |
be55bfe6 | 2638 | FOR_EACH_BB_FN (bb, fun) |
bbcb0c05 | 2639 | { |
e93768e4 | 2640 | rtx_insn *insn; |
00b28cb0 SB |
2641 | edge e; |
2642 | edge_iterator ei; | |
2643 | int size, all_flags; | |
2644 | ||
2645 | /* Build the reorder chain for the original order of blocks. */ | |
be55bfe6 | 2646 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (fun)) |
370369e1 | 2647 | bb->aux = bb->next_bb; |
bbcb0c05 | 2648 | |
00b28cb0 SB |
2649 | /* Obviously the block has to end in a computed jump. */ |
2650 | if (!computed_jump_p (BB_END (bb))) | |
2651 | continue; | |
bbcb0c05 | 2652 | |
00b28cb0 | 2653 | /* Only consider blocks that can be duplicated. */ |
339ba33b | 2654 | if (CROSSING_JUMP_P (BB_END (bb)) |
00b28cb0 SB |
2655 | || !can_duplicate_block_p (bb)) |
2656 | continue; | |
bbcb0c05 | 2657 | |
00b28cb0 SB |
2658 | /* Make sure that the block is small enough. */ |
2659 | size = 0; | |
2660 | FOR_BB_INSNS (bb, insn) | |
2661 | if (INSN_P (insn)) | |
2662 | { | |
070a7956 | 2663 | size += get_attr_min_length (insn); |
00b28cb0 SB |
2664 | if (size > max_size) |
2665 | break; | |
2666 | } | |
2667 | if (size > max_size) | |
2668 | continue; | |
2669 | ||
2670 | /* Final check: there must not be any incoming abnormal edges. */ | |
2671 | all_flags = 0; | |
2672 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2673 | all_flags |= e->flags; | |
2674 | if (all_flags & EDGE_COMPLEX) | |
2675 | continue; | |
2676 | ||
2677 | bitmap_set_bit (candidates, bb->index); | |
bbcb0c05 SB |
2678 | } |
2679 | ||
2680 | /* Nothing to do if there is no computed jump here. */ | |
2681 | if (bitmap_empty_p (candidates)) | |
2682 | goto done; | |
2683 | ||
2684 | /* Duplicate computed gotos. */ | |
be55bfe6 | 2685 | FOR_EACH_BB_FN (bb, fun) |
bbcb0c05 | 2686 | { |
bcc708fc | 2687 | if (bb->flags & BB_VISITED) |
bbcb0c05 SB |
2688 | continue; |
2689 | ||
bcc708fc | 2690 | bb->flags |= BB_VISITED; |
bbcb0c05 SB |
2691 | |
2692 | /* BB must have one outgoing edge. That edge must not lead to | |
c22cacf3 | 2693 | the exit block or the next block. |
bbcb0c05 | 2694 | The destination must have more than one predecessor. */ |
c5cbcccf | 2695 | if (!single_succ_p (bb) |
be55bfe6 | 2696 | || single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (fun) |
c5cbcccf ZD |
2697 | || single_succ (bb) == bb->next_bb |
2698 | || single_pred_p (single_succ (bb))) | |
bbcb0c05 SB |
2699 | continue; |
2700 | ||
2701 | /* The successor block has to be a duplication candidate. */ | |
c5cbcccf | 2702 | if (!bitmap_bit_p (candidates, single_succ (bb)->index)) |
bbcb0c05 SB |
2703 | continue; |
2704 | ||
3371a64f TJ |
2705 | /* Don't duplicate a partition crossing edge, which requires difficult |
2706 | fixup. */ | |
339ba33b | 2707 | if (JUMP_P (BB_END (bb)) && CROSSING_JUMP_P (BB_END (bb))) |
3371a64f TJ |
2708 | continue; |
2709 | ||
b9a66240 | 2710 | new_bb = duplicate_block (single_succ (bb), single_succ_edge (bb), bb); |
370369e1 JH |
2711 | new_bb->aux = bb->aux; |
2712 | bb->aux = new_bb; | |
bcc708fc | 2713 | new_bb->flags |= BB_VISITED; |
b55bf120 | 2714 | changed = true; |
bbcb0c05 SB |
2715 | } |
2716 | ||
fc56f9d2 | 2717 | done: |
b55bf120 | 2718 | if (changed) |
fc56f9d2 RH |
2719 | { |
2720 | /* Duplicating blocks above will redirect edges and may cause hot | |
2721 | blocks previously reached by both hot and cold blocks to become | |
2722 | dominated only by cold blocks. */ | |
2723 | fixup_partitions (); | |
2724 | ||
2725 | /* Merge the duplicated blocks into predecessors, when possible. */ | |
2726 | cfg_layout_finalize (); | |
2727 | cleanup_cfg (0); | |
2728 | } | |
2729 | else | |
2730 | cfg_layout_finalize (); | |
bbcb0c05 | 2731 | |
8bdbfff5 | 2732 | BITMAP_FREE (candidates); |
c2924966 | 2733 | return 0; |
bbcb0c05 | 2734 | } |
750054a2 | 2735 | |
27a4cd48 DM |
2736 | } // anon namespace |
2737 | ||
2738 | rtl_opt_pass * | |
2739 | make_pass_duplicate_computed_gotos (gcc::context *ctxt) | |
2740 | { | |
2741 | return new pass_duplicate_computed_gotos (ctxt); | |
2742 | } | |
2743 | ||
750054a2 CT |
2744 | /* This function is the main 'entrance' for the optimization that |
2745 | partitions hot and cold basic blocks into separate sections of the | |
2746 | .o file (to improve performance and cache locality). Ideally it | |
2747 | would be called after all optimizations that rearrange the CFG have | |
2748 | been called. However part of this optimization may introduce new | |
2749 | register usage, so it must be called before register allocation has | |
2750 | occurred. This means that this optimization is actually called | |
8e8d5162 CT |
2751 | well before the optimization that reorders basic blocks (see |
2752 | function above). | |
750054a2 CT |
2753 | |
2754 | This optimization checks the feedback information to determine | |
87c8b4be CT |
2755 | which basic blocks are hot/cold, updates flags on the basic blocks |
2756 | to indicate which section they belong in. This information is | |
2757 | later used for writing out sections in the .o file. Because hot | |
2758 | and cold sections can be arbitrarily large (within the bounds of | |
2759 | memory), far beyond the size of a single function, it is necessary | |
2760 | to fix up all edges that cross section boundaries, to make sure the | |
2761 | instructions used can actually span the required distance. The | |
2762 | fixes are described below. | |
8e8d5162 CT |
2763 | |
2764 | Fall-through edges must be changed into jumps; it is not safe or | |
2765 | legal to fall through across a section boundary. Whenever a | |
2766 | fall-through edge crossing a section boundary is encountered, a new | |
2767 | basic block is inserted (in the same section as the fall-through | |
2768 | source), and the fall through edge is redirected to the new basic | |
2769 | block. The new basic block contains an unconditional jump to the | |
2770 | original fall-through target. (If the unconditional jump is | |
2771 | insufficient to cross section boundaries, that is dealt with a | |
2772 | little later, see below). | |
2773 | ||
2774 | In order to deal with architectures that have short conditional | |
2775 | branches (which cannot span all of memory) we take any conditional | |
2776 | jump that attempts to cross a section boundary and add a level of | |
2777 | indirection: it becomes a conditional jump to a new basic block, in | |
2778 | the same section. The new basic block contains an unconditional | |
2779 | jump to the original target, in the other section. | |
2780 | ||
2781 | For those architectures whose unconditional branch is also | |
2782 | incapable of reaching all of memory, those unconditional jumps are | |
2783 | converted into indirect jumps, through a register. | |
2784 | ||
2785 | IMPORTANT NOTE: This optimization causes some messy interactions | |
2786 | with the cfg cleanup optimizations; those optimizations want to | |
2787 | merge blocks wherever possible, and to collapse indirect jump | |
2788 | sequences (change "A jumps to B jumps to C" directly into "A jumps | |
2789 | to C"). Those optimizations can undo the jump fixes that | |
2790 | partitioning is required to make (see above), in order to ensure | |
2791 | that jumps attempting to cross section boundaries are really able | |
2792 | to cover whatever distance the jump requires (on many architectures | |
2793 | conditional or unconditional jumps are not able to reach all of | |
2794 | memory). Therefore tests have to be inserted into each such | |
2795 | optimization to make sure that it does not undo stuff necessary to | |
2796 | cross partition boundaries. This would be much less of a problem | |
2797 | if we could perform this optimization later in the compilation, but | |
2798 | unfortunately the fact that we may need to create indirect jumps | |
2799 | (through registers) requires that this optimization be performed | |
ea6136a2 | 2800 | before register allocation. |
750054a2 | 2801 | |
ea6136a2 RH |
2802 | Hot and cold basic blocks are partitioned and put in separate |
2803 | sections of the .o file, to reduce paging and improve cache | |
2804 | performance (hopefully). This can result in bits of code from the | |
2805 | same function being widely separated in the .o file. However this | |
2806 | is not obvious to the current bb structure. Therefore we must take | |
2807 | care to ensure that: 1). There are no fall_thru edges that cross | |
2808 | between sections; 2). For those architectures which have "short" | |
2809 | conditional branches, all conditional branches that attempt to | |
2810 | cross between sections are converted to unconditional branches; | |
2811 | and, 3). For those architectures which have "short" unconditional | |
2812 | branches, all unconditional branches that attempt to cross between | |
2813 | sections are converted to indirect jumps. | |
2814 | ||
2815 | The code for fixing up fall_thru edges that cross between hot and | |
2816 | cold basic blocks does so by creating new basic blocks containing | |
2817 | unconditional branches to the appropriate label in the "other" | |
2818 | section. The new basic block is then put in the same (hot or cold) | |
2819 | section as the original conditional branch, and the fall_thru edge | |
2820 | is modified to fall into the new basic block instead. By adding | |
2821 | this level of indirection we end up with only unconditional branches | |
2822 | crossing between hot and cold sections. | |
2823 | ||
2824 | Conditional branches are dealt with by adding a level of indirection. | |
2825 | A new basic block is added in the same (hot/cold) section as the | |
2826 | conditional branch, and the conditional branch is retargeted to the | |
2827 | new basic block. The new basic block contains an unconditional branch | |
2828 | to the original target of the conditional branch (in the other section). | |
2829 | ||
2830 | Unconditional branches are dealt with by converting them into | |
2831 | indirect jumps. */ | |
2832 | ||
be55bfe6 TS |
2833 | namespace { |
2834 | ||
2835 | const pass_data pass_data_partition_blocks = | |
2836 | { | |
2837 | RTL_PASS, /* type */ | |
2838 | "bbpart", /* name */ | |
2839 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
2840 | TV_REORDER_BLOCKS, /* tv_id */ |
2841 | PROP_cfglayout, /* properties_required */ | |
2842 | 0, /* properties_provided */ | |
2843 | 0, /* properties_destroyed */ | |
2844 | 0, /* todo_flags_start */ | |
2845 | 0, /* todo_flags_finish */ | |
2846 | }; | |
2847 | ||
2848 | class pass_partition_blocks : public rtl_opt_pass | |
2849 | { | |
2850 | public: | |
2851 | pass_partition_blocks (gcc::context *ctxt) | |
2852 | : rtl_opt_pass (pass_data_partition_blocks, ctxt) | |
2853 | {} | |
2854 | ||
2855 | /* opt_pass methods: */ | |
2856 | virtual bool gate (function *); | |
2857 | virtual unsigned int execute (function *); | |
2858 | ||
2859 | }; // class pass_partition_blocks | |
2860 | ||
2861 | bool | |
2862 | pass_partition_blocks::gate (function *fun) | |
2863 | { | |
2864 | /* The optimization to partition hot/cold basic blocks into separate | |
2865 | sections of the .o file does not work well with linkonce or with | |
2866 | user defined section attributes. Don't call it if either case | |
2867 | arises. */ | |
2868 | return (flag_reorder_blocks_and_partition | |
2869 | && optimize | |
2870 | /* See gate_handle_reorder_blocks. We should not partition if | |
2871 | we are going to omit the reordering. */ | |
2872 | && optimize_function_for_speed_p (fun) | |
cf288ed3 | 2873 | && !DECL_COMDAT_GROUP (current_function_decl) |
be55bfe6 TS |
2874 | && !user_defined_section_attribute); |
2875 | } | |
2876 | ||
2877 | unsigned | |
2878 | pass_partition_blocks::execute (function *fun) | |
750054a2 | 2879 | { |
9771b263 | 2880 | vec<edge> crossing_edges; |
c22cacf3 | 2881 | |
be55bfe6 | 2882 | if (n_basic_blocks_for_fn (fun) <= NUM_FIXED_BLOCKS + 1) |
ea6136a2 RH |
2883 | return 0; |
2884 | ||
0be7e7a6 RH |
2885 | df_set_flags (DF_DEFER_INSN_RESCAN); |
2886 | ||
ea6136a2 | 2887 | crossing_edges = find_rarely_executed_basic_blocks_and_crossing_edges (); |
9771b263 | 2888 | if (!crossing_edges.exists ()) |
ea6136a2 RH |
2889 | return 0; |
2890 | ||
af205f67 TJ |
2891 | crtl->has_bb_partition = true; |
2892 | ||
ea6136a2 RH |
2893 | /* Make sure the source of any crossing edge ends in a jump and the |
2894 | destination of any crossing edge has a label. */ | |
2895 | add_labels_and_missing_jumps (crossing_edges); | |
2896 | ||
2897 | /* Convert all crossing fall_thru edges to non-crossing fall | |
2898 | thrus to unconditional jumps (that jump to the original fall | |
073a8998 | 2899 | through dest). */ |
ea6136a2 RH |
2900 | fix_up_fall_thru_edges (); |
2901 | ||
2902 | /* If the architecture does not have conditional branches that can | |
2903 | span all of memory, convert crossing conditional branches into | |
2904 | crossing unconditional branches. */ | |
2905 | if (!HAS_LONG_COND_BRANCH) | |
2906 | fix_crossing_conditional_branches (); | |
c22cacf3 | 2907 | |
ea6136a2 RH |
2908 | /* If the architecture does not have unconditional branches that |
2909 | can span all of memory, convert crossing unconditional branches | |
2910 | into indirect jumps. Since adding an indirect jump also adds | |
2911 | a new register usage, update the register usage information as | |
2912 | well. */ | |
2913 | if (!HAS_LONG_UNCOND_BRANCH) | |
2914 | fix_crossing_unconditional_branches (); | |
750054a2 | 2915 | |
339ba33b | 2916 | update_crossing_jump_flags (); |
750054a2 | 2917 | |
b71d7f85 JJ |
2918 | /* Clear bb->aux fields that the above routines were using. */ |
2919 | clear_aux_for_blocks (); | |
2920 | ||
9771b263 | 2921 | crossing_edges.release (); |
c22cacf3 | 2922 | |
0be7e7a6 RH |
2923 | /* ??? FIXME: DF generates the bb info for a block immediately. |
2924 | And by immediately, I mean *during* creation of the block. | |
2925 | ||
2926 | #0 df_bb_refs_collect | |
2927 | #1 in df_bb_refs_record | |
2928 | #2 in create_basic_block_structure | |
2929 | ||
2930 | Which means that the bb_has_eh_pred test in df_bb_refs_collect | |
2931 | will *always* fail, because no edges can have been added to the | |
2932 | block yet. Which of course means we don't add the right | |
2933 | artificial refs, which means we fail df_verify (much) later. | |
2934 | ||
2935 | Cleanest solution would seem to make DF_DEFER_INSN_RESCAN imply | |
2936 | that we also shouldn't grab data from the new blocks those new | |
2937 | insns are in either. In this way one can create the block, link | |
2938 | it up properly, and have everything Just Work later, when deferred | |
2939 | insns are processed. | |
2940 | ||
2941 | In the meantime, we have no other option but to throw away all | |
2942 | of the DF data and recompute it all. */ | |
be55bfe6 | 2943 | if (fun->eh->lp_array) |
0be7e7a6 RH |
2944 | { |
2945 | df_finish_pass (true); | |
2946 | df_scan_alloc (NULL); | |
2947 | df_scan_blocks (); | |
2948 | /* Not all post-landing pads use all of the EH_RETURN_DATA_REGNO | |
2949 | data. We blindly generated all of them when creating the new | |
2950 | landing pad. Delete those assignments we don't use. */ | |
2951 | df_set_flags (DF_LR_RUN_DCE); | |
2952 | df_analyze (); | |
2953 | } | |
2954 | ||
3bea341f | 2955 | return 0; |
750054a2 | 2956 | } |
ef330312 | 2957 | |
27a4cd48 DM |
2958 | } // anon namespace |
2959 | ||
2960 | rtl_opt_pass * | |
2961 | make_pass_partition_blocks (gcc::context *ctxt) | |
2962 | { | |
2963 | return new pass_partition_blocks (ctxt); | |
2964 | } |