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3e485f62 | 1 | /* Function splitting pass |
a348dc7f | 2 | Copyright (C) 2010, 2011, 2012 |
3e485f62 JH |
3 | Free Software Foundation, Inc. |
4 | Contributed by Jan Hubicka <jh@suse.cz> | |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 3, or (at your option) any later | |
11 | version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | /* The purpose of this pass is to split function bodies to improve | |
23 | inlining. I.e. for function of the form: | |
24 | ||
25 | func (...) | |
26 | { | |
27 | if (cheap_test) | |
28 | something_small | |
29 | else | |
30 | something_big | |
31 | } | |
32 | ||
33 | Produce: | |
34 | ||
35 | func.part (...) | |
36 | { | |
37 | something_big | |
38 | } | |
39 | ||
40 | func (...) | |
41 | { | |
42 | if (cheap_test) | |
43 | something_small | |
44 | else | |
45 | func.part (...); | |
46 | } | |
47 | ||
48 | When func becomes inlinable and when cheap_test is often true, inlining func, | |
ed7656f6 | 49 | but not fund.part leads to performance improvement similar as inlining |
3e485f62 JH |
50 | original func while the code size growth is smaller. |
51 | ||
52 | The pass is organized in three stages: | |
53 | 1) Collect local info about basic block into BB_INFO structure and | |
54 | compute function body estimated size and time. | |
55 | 2) Via DFS walk find all possible basic blocks where we can split | |
56 | and chose best one. | |
57 | 3) If split point is found, split at the specified BB by creating a clone | |
58 | and updating function to call it. | |
59 | ||
60 | The decisions what functions to split are in execute_split_functions | |
61 | and consider_split. | |
62 | ||
63 | There are several possible future improvements for this pass including: | |
64 | ||
65 | 1) Splitting to break up large functions | |
66 | 2) Splitting to reduce stack frame usage | |
67 | 3) Allow split part of function to use values computed in the header part. | |
68 | The values needs to be passed to split function, perhaps via same | |
69 | interface as for nested functions or as argument. | |
70 | 4) Support for simple rematerialization. I.e. when split part use | |
71 | value computed in header from function parameter in very cheap way, we | |
72 | can just recompute it. | |
73 | 5) Support splitting of nested functions. | |
74 | 6) Support non-SSA arguments. | |
75 | 7) There is nothing preventing us from producing multiple parts of single function | |
76 | when needed or splitting also the parts. */ | |
77 | ||
78 | #include "config.h" | |
79 | #include "system.h" | |
80 | #include "coretypes.h" | |
81 | #include "tree.h" | |
82 | #include "target.h" | |
83 | #include "cgraph.h" | |
84 | #include "ipa-prop.h" | |
85 | #include "tree-flow.h" | |
86 | #include "tree-pass.h" | |
87 | #include "flags.h" | |
3e485f62 JH |
88 | #include "diagnostic.h" |
89 | #include "tree-dump.h" | |
90 | #include "tree-inline.h" | |
3e485f62 JH |
91 | #include "params.h" |
92 | #include "gimple-pretty-print.h" | |
e7f23018 | 93 | #include "ipa-inline.h" |
3e485f62 JH |
94 | |
95 | /* Per basic block info. */ | |
96 | ||
97 | typedef struct | |
98 | { | |
99 | unsigned int size; | |
100 | unsigned int time; | |
101 | } bb_info; | |
102 | DEF_VEC_O(bb_info); | |
103 | DEF_VEC_ALLOC_O(bb_info,heap); | |
104 | ||
105 | static VEC(bb_info, heap) *bb_info_vec; | |
106 | ||
107 | /* Description of split point. */ | |
108 | ||
109 | struct split_point | |
110 | { | |
111 | /* Size of the partitions. */ | |
112 | unsigned int header_time, header_size, split_time, split_size; | |
113 | ||
ed7656f6 | 114 | /* SSA names that need to be passed into spit function. */ |
3e485f62 JH |
115 | bitmap ssa_names_to_pass; |
116 | ||
117 | /* Basic block where we split (that will become entry point of new function. */ | |
118 | basic_block entry_bb; | |
119 | ||
120 | /* Basic blocks we are splitting away. */ | |
121 | bitmap split_bbs; | |
241a2b9e JH |
122 | |
123 | /* True when return value is computed on split part and thus it needs | |
124 | to be returned. */ | |
125 | bool split_part_set_retval; | |
3e485f62 JH |
126 | }; |
127 | ||
128 | /* Best split point found. */ | |
129 | ||
130 | struct split_point best_split_point; | |
131 | ||
b2e25729 BS |
132 | /* Set of basic blocks that are not allowed to dominate a split point. */ |
133 | ||
134 | static bitmap forbidden_dominators; | |
135 | ||
241a2b9e JH |
136 | static tree find_retval (basic_block return_bb); |
137 | ||
1802378d | 138 | /* Callback for walk_stmt_load_store_addr_ops. If T is non-SSA automatic |
3e485f62 JH |
139 | variable, check it if it is present in bitmap passed via DATA. */ |
140 | ||
141 | static bool | |
1802378d | 142 | test_nonssa_use (gimple stmt ATTRIBUTE_UNUSED, tree t, void *data) |
3e485f62 JH |
143 | { |
144 | t = get_base_address (t); | |
145 | ||
1802378d EB |
146 | if (!t || is_gimple_reg (t)) |
147 | return false; | |
148 | ||
149 | if (TREE_CODE (t) == PARM_DECL | |
150 | || (TREE_CODE (t) == VAR_DECL | |
3e485f62 | 151 | && auto_var_in_fn_p (t, current_function_decl)) |
1802378d EB |
152 | || TREE_CODE (t) == RESULT_DECL |
153 | || TREE_CODE (t) == LABEL_DECL) | |
3e485f62 | 154 | return bitmap_bit_p ((bitmap)data, DECL_UID (t)); |
241a2b9e | 155 | |
1802378d EB |
156 | /* For DECL_BY_REFERENCE, the return value is actually a pointer. We want |
157 | to pretend that the value pointed to is actual result decl. */ | |
158 | if ((TREE_CODE (t) == MEM_REF || INDIRECT_REF_P (t)) | |
241a2b9e | 159 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
70b5e7dc | 160 | && SSA_NAME_VAR (TREE_OPERAND (t, 0)) |
241a2b9e JH |
161 | && TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (t, 0))) == RESULT_DECL |
162 | && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) | |
1802378d EB |
163 | return |
164 | bitmap_bit_p ((bitmap)data, | |
165 | DECL_UID (DECL_RESULT (current_function_decl))); | |
166 | ||
3e485f62 JH |
167 | return false; |
168 | } | |
169 | ||
170 | /* Dump split point CURRENT. */ | |
171 | ||
172 | static void | |
173 | dump_split_point (FILE * file, struct split_point *current) | |
174 | { | |
175 | fprintf (file, | |
cfef45c8 RG |
176 | "Split point at BB %i\n" |
177 | " header time: %i header size: %i\n" | |
178 | " split time: %i split size: %i\n bbs: ", | |
3e485f62 JH |
179 | current->entry_bb->index, current->header_time, |
180 | current->header_size, current->split_time, current->split_size); | |
181 | dump_bitmap (file, current->split_bbs); | |
182 | fprintf (file, " SSA names to pass: "); | |
183 | dump_bitmap (file, current->ssa_names_to_pass); | |
184 | } | |
185 | ||
1802378d EB |
186 | /* Look for all BBs in header that might lead to the split part and verify |
187 | that they are not defining any non-SSA var used by the split part. | |
2094f1fc JH |
188 | Parameters are the same as for consider_split. */ |
189 | ||
190 | static bool | |
191 | verify_non_ssa_vars (struct split_point *current, bitmap non_ssa_vars, | |
192 | basic_block return_bb) | |
193 | { | |
194 | bitmap seen = BITMAP_ALLOC (NULL); | |
195 | VEC (basic_block,heap) *worklist = NULL; | |
196 | edge e; | |
197 | edge_iterator ei; | |
198 | bool ok = true; | |
1802378d | 199 | |
2094f1fc JH |
200 | FOR_EACH_EDGE (e, ei, current->entry_bb->preds) |
201 | if (e->src != ENTRY_BLOCK_PTR | |
202 | && !bitmap_bit_p (current->split_bbs, e->src->index)) | |
203 | { | |
204 | VEC_safe_push (basic_block, heap, worklist, e->src); | |
205 | bitmap_set_bit (seen, e->src->index); | |
206 | } | |
1802378d | 207 | |
2094f1fc JH |
208 | while (!VEC_empty (basic_block, worklist)) |
209 | { | |
210 | gimple_stmt_iterator bsi; | |
211 | basic_block bb = VEC_pop (basic_block, worklist); | |
212 | ||
213 | FOR_EACH_EDGE (e, ei, bb->preds) | |
214 | if (e->src != ENTRY_BLOCK_PTR | |
fcaa4ca4 | 215 | && bitmap_set_bit (seen, e->src->index)) |
2094f1fc JH |
216 | { |
217 | gcc_checking_assert (!bitmap_bit_p (current->split_bbs, | |
218 | e->src->index)); | |
219 | VEC_safe_push (basic_block, heap, worklist, e->src); | |
2094f1fc JH |
220 | } |
221 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
222 | { | |
1802378d EB |
223 | gimple stmt = gsi_stmt (bsi); |
224 | if (is_gimple_debug (stmt)) | |
2094f1fc JH |
225 | continue; |
226 | if (walk_stmt_load_store_addr_ops | |
1802378d EB |
227 | (stmt, non_ssa_vars, test_nonssa_use, test_nonssa_use, |
228 | test_nonssa_use)) | |
2094f1fc JH |
229 | { |
230 | ok = false; | |
231 | goto done; | |
232 | } | |
1802378d EB |
233 | if (gimple_code (stmt) == GIMPLE_LABEL |
234 | && test_nonssa_use (stmt, gimple_label_label (stmt), | |
235 | non_ssa_vars)) | |
236 | { | |
237 | ok = false; | |
238 | goto done; | |
239 | } | |
2094f1fc JH |
240 | } |
241 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
242 | { | |
243 | if (walk_stmt_load_store_addr_ops | |
1802378d EB |
244 | (gsi_stmt (bsi), non_ssa_vars, test_nonssa_use, test_nonssa_use, |
245 | test_nonssa_use)) | |
2094f1fc JH |
246 | { |
247 | ok = false; | |
248 | goto done; | |
249 | } | |
250 | } | |
251 | FOR_EACH_EDGE (e, ei, bb->succs) | |
252 | { | |
253 | if (e->dest != return_bb) | |
254 | continue; | |
255 | for (bsi = gsi_start_phis (return_bb); !gsi_end_p (bsi); | |
256 | gsi_next (&bsi)) | |
257 | { | |
258 | gimple stmt = gsi_stmt (bsi); | |
259 | tree op = gimple_phi_arg_def (stmt, e->dest_idx); | |
260 | ||
ea057359 | 261 | if (virtual_operand_p (gimple_phi_result (stmt))) |
2094f1fc JH |
262 | continue; |
263 | if (TREE_CODE (op) != SSA_NAME | |
264 | && test_nonssa_use (stmt, op, non_ssa_vars)) | |
265 | { | |
266 | ok = false; | |
267 | goto done; | |
268 | } | |
269 | } | |
270 | } | |
271 | } | |
272 | done: | |
273 | BITMAP_FREE (seen); | |
274 | VEC_free (basic_block, heap, worklist); | |
275 | return ok; | |
276 | } | |
277 | ||
b2e25729 BS |
278 | /* If STMT is a call, check the callee against a list of forbidden |
279 | predicate functions. If a match is found, look for uses of the | |
280 | call result in condition statements that compare against zero. | |
281 | For each such use, find the block targeted by the condition | |
282 | statement for the nonzero result, and set the bit for this block | |
283 | in the forbidden dominators bitmap. The purpose of this is to avoid | |
284 | selecting a split point where we are likely to lose the chance | |
285 | to optimize away an unused function call. */ | |
286 | ||
287 | static void | |
288 | check_forbidden_calls (gimple stmt) | |
289 | { | |
290 | imm_use_iterator use_iter; | |
291 | use_operand_p use_p; | |
292 | tree lhs; | |
293 | ||
294 | /* At the moment, __builtin_constant_p is the only forbidden | |
295 | predicate function call (see PR49642). */ | |
296 | if (!gimple_call_builtin_p (stmt, BUILT_IN_CONSTANT_P)) | |
297 | return; | |
298 | ||
299 | lhs = gimple_call_lhs (stmt); | |
300 | ||
301 | if (!lhs || TREE_CODE (lhs) != SSA_NAME) | |
302 | return; | |
303 | ||
304 | FOR_EACH_IMM_USE_FAST (use_p, use_iter, lhs) | |
305 | { | |
306 | tree op1; | |
307 | basic_block use_bb, forbidden_bb; | |
308 | enum tree_code code; | |
309 | edge true_edge, false_edge; | |
310 | gimple use_stmt = USE_STMT (use_p); | |
311 | ||
312 | if (gimple_code (use_stmt) != GIMPLE_COND) | |
313 | continue; | |
314 | ||
315 | /* Assuming canonical form for GIMPLE_COND here, with constant | |
316 | in second position. */ | |
317 | op1 = gimple_cond_rhs (use_stmt); | |
318 | code = gimple_cond_code (use_stmt); | |
319 | use_bb = gimple_bb (use_stmt); | |
320 | ||
321 | extract_true_false_edges_from_block (use_bb, &true_edge, &false_edge); | |
322 | ||
323 | /* We're only interested in comparisons that distinguish | |
324 | unambiguously from zero. */ | |
325 | if (!integer_zerop (op1) || code == LE_EXPR || code == GE_EXPR) | |
326 | continue; | |
327 | ||
328 | if (code == EQ_EXPR) | |
329 | forbidden_bb = false_edge->dest; | |
330 | else | |
331 | forbidden_bb = true_edge->dest; | |
332 | ||
333 | bitmap_set_bit (forbidden_dominators, forbidden_bb->index); | |
334 | } | |
335 | } | |
336 | ||
337 | /* If BB is dominated by any block in the forbidden dominators set, | |
338 | return TRUE; else FALSE. */ | |
339 | ||
340 | static bool | |
341 | dominated_by_forbidden (basic_block bb) | |
342 | { | |
343 | unsigned dom_bb; | |
344 | bitmap_iterator bi; | |
345 | ||
346 | EXECUTE_IF_SET_IN_BITMAP (forbidden_dominators, 1, dom_bb, bi) | |
347 | { | |
348 | if (dominated_by_p (CDI_DOMINATORS, bb, BASIC_BLOCK (dom_bb))) | |
349 | return true; | |
350 | } | |
351 | ||
352 | return false; | |
353 | } | |
354 | ||
3e485f62 JH |
355 | /* We found an split_point CURRENT. NON_SSA_VARS is bitmap of all non ssa |
356 | variables used and RETURN_BB is return basic block. | |
357 | See if we can split function here. */ | |
358 | ||
359 | static void | |
360 | consider_split (struct split_point *current, bitmap non_ssa_vars, | |
361 | basic_block return_bb) | |
362 | { | |
363 | tree parm; | |
364 | unsigned int num_args = 0; | |
365 | unsigned int call_overhead; | |
366 | edge e; | |
367 | edge_iterator ei; | |
8b3057b3 JH |
368 | gimple_stmt_iterator bsi; |
369 | unsigned int i; | |
ed7656f6 | 370 | int incoming_freq = 0; |
241a2b9e | 371 | tree retval; |
8b3057b3 | 372 | |
3e485f62 JH |
373 | if (dump_file && (dump_flags & TDF_DETAILS)) |
374 | dump_split_point (dump_file, current); | |
375 | ||
8b3057b3 JH |
376 | FOR_EACH_EDGE (e, ei, current->entry_bb->preds) |
377 | if (!bitmap_bit_p (current->split_bbs, e->src->index)) | |
ed7656f6 | 378 | incoming_freq += EDGE_FREQUENCY (e); |
8b3057b3 | 379 | |
3e485f62 | 380 | /* Do not split when we would end up calling function anyway. */ |
ed7656f6 | 381 | if (incoming_freq |
3e485f62 JH |
382 | >= (ENTRY_BLOCK_PTR->frequency |
383 | * PARAM_VALUE (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY) / 100)) | |
384 | { | |
385 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
386 | fprintf (dump_file, | |
ed7656f6 | 387 | " Refused: incoming frequency is too large.\n"); |
3e485f62 JH |
388 | return; |
389 | } | |
390 | ||
391 | if (!current->header_size) | |
392 | { | |
393 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
394 | fprintf (dump_file, " Refused: header empty\n"); | |
3e485f62 JH |
395 | return; |
396 | } | |
397 | ||
ed7656f6 JJ |
398 | /* Verify that PHI args on entry are either virtual or all their operands |
399 | incoming from header are the same. */ | |
8b3057b3 | 400 | for (bsi = gsi_start_phis (current->entry_bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
3e485f62 | 401 | { |
8b3057b3 JH |
402 | gimple stmt = gsi_stmt (bsi); |
403 | tree val = NULL; | |
404 | ||
ea057359 | 405 | if (virtual_operand_p (gimple_phi_result (stmt))) |
8b3057b3 JH |
406 | continue; |
407 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
408 | { | |
409 | edge e = gimple_phi_arg_edge (stmt, i); | |
410 | if (!bitmap_bit_p (current->split_bbs, e->src->index)) | |
411 | { | |
412 | tree edge_val = gimple_phi_arg_def (stmt, i); | |
413 | if (val && edge_val != val) | |
414 | { | |
415 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
416 | fprintf (dump_file, | |
417 | " Refused: entry BB has PHI with multiple variants\n"); | |
418 | return; | |
419 | } | |
420 | val = edge_val; | |
421 | } | |
422 | } | |
3e485f62 JH |
423 | } |
424 | ||
425 | ||
426 | /* See what argument we will pass to the split function and compute | |
427 | call overhead. */ | |
428 | call_overhead = eni_size_weights.call_cost; | |
429 | for (parm = DECL_ARGUMENTS (current_function_decl); parm; | |
910ad8de | 430 | parm = DECL_CHAIN (parm)) |
3e485f62 JH |
431 | { |
432 | if (!is_gimple_reg (parm)) | |
433 | { | |
434 | if (bitmap_bit_p (non_ssa_vars, DECL_UID (parm))) | |
435 | { | |
436 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
437 | fprintf (dump_file, | |
438 | " Refused: need to pass non-ssa param values\n"); | |
439 | return; | |
440 | } | |
441 | } | |
32244553 | 442 | else |
3e485f62 | 443 | { |
32244553 RG |
444 | tree ddef = ssa_default_def (cfun, parm); |
445 | if (ddef | |
446 | && bitmap_bit_p (current->ssa_names_to_pass, | |
447 | SSA_NAME_VERSION (ddef))) | |
448 | { | |
449 | if (!VOID_TYPE_P (TREE_TYPE (parm))) | |
450 | call_overhead += estimate_move_cost (TREE_TYPE (parm)); | |
451 | num_args++; | |
452 | } | |
3e485f62 JH |
453 | } |
454 | } | |
455 | if (!VOID_TYPE_P (TREE_TYPE (current_function_decl))) | |
456 | call_overhead += estimate_move_cost (TREE_TYPE (current_function_decl)); | |
457 | ||
458 | if (current->split_size <= call_overhead) | |
459 | { | |
460 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
461 | fprintf (dump_file, | |
462 | " Refused: split size is smaller than call overhead\n"); | |
463 | return; | |
464 | } | |
465 | if (current->header_size + call_overhead | |
466 | >= (unsigned int)(DECL_DECLARED_INLINE_P (current_function_decl) | |
467 | ? MAX_INLINE_INSNS_SINGLE | |
468 | : MAX_INLINE_INSNS_AUTO)) | |
469 | { | |
470 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
471 | fprintf (dump_file, | |
472 | " Refused: header size is too large for inline candidate\n"); | |
473 | return; | |
474 | } | |
475 | ||
476 | /* FIXME: we currently can pass only SSA function parameters to the split | |
d402c33d | 477 | arguments. Once parm_adjustment infrastructure is supported by cloning, |
3e485f62 JH |
478 | we can pass more than that. */ |
479 | if (num_args != bitmap_count_bits (current->ssa_names_to_pass)) | |
480 | { | |
8b3057b3 | 481 | |
3e485f62 JH |
482 | if (dump_file && (dump_flags & TDF_DETAILS)) |
483 | fprintf (dump_file, | |
484 | " Refused: need to pass non-param values\n"); | |
485 | return; | |
486 | } | |
487 | ||
488 | /* When there are non-ssa vars used in the split region, see if they | |
489 | are used in the header region. If so, reject the split. | |
490 | FIXME: we can use nested function support to access both. */ | |
2094f1fc JH |
491 | if (!bitmap_empty_p (non_ssa_vars) |
492 | && !verify_non_ssa_vars (current, non_ssa_vars, return_bb)) | |
3e485f62 | 493 | { |
2094f1fc JH |
494 | if (dump_file && (dump_flags & TDF_DETAILS)) |
495 | fprintf (dump_file, | |
496 | " Refused: split part has non-ssa uses\n"); | |
3e485f62 JH |
497 | return; |
498 | } | |
b2e25729 BS |
499 | |
500 | /* If the split point is dominated by a forbidden block, reject | |
501 | the split. */ | |
502 | if (!bitmap_empty_p (forbidden_dominators) | |
503 | && dominated_by_forbidden (current->entry_bb)) | |
504 | { | |
505 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
506 | fprintf (dump_file, | |
507 | " Refused: split point dominated by forbidden block\n"); | |
508 | return; | |
509 | } | |
510 | ||
241a2b9e JH |
511 | /* See if retval used by return bb is computed by header or split part. |
512 | When it is computed by split part, we need to produce return statement | |
513 | in the split part and add code to header to pass it around. | |
514 | ||
515 | This is bit tricky to test: | |
516 | 1) When there is no return_bb or no return value, we always pass | |
517 | value around. | |
518 | 2) Invariants are always computed by caller. | |
519 | 3) For SSA we need to look if defining statement is in header or split part | |
520 | 4) For non-SSA we need to look where the var is computed. */ | |
521 | retval = find_retval (return_bb); | |
522 | if (!retval) | |
523 | current->split_part_set_retval = true; | |
524 | else if (is_gimple_min_invariant (retval)) | |
525 | current->split_part_set_retval = false; | |
526 | /* Special case is value returned by reference we record as if it was non-ssa | |
527 | set to result_decl. */ | |
528 | else if (TREE_CODE (retval) == SSA_NAME | |
70b5e7dc | 529 | && SSA_NAME_VAR (retval) |
241a2b9e JH |
530 | && TREE_CODE (SSA_NAME_VAR (retval)) == RESULT_DECL |
531 | && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) | |
532 | current->split_part_set_retval | |
533 | = bitmap_bit_p (non_ssa_vars, DECL_UID (SSA_NAME_VAR (retval))); | |
534 | else if (TREE_CODE (retval) == SSA_NAME) | |
535 | current->split_part_set_retval | |
536 | = (!SSA_NAME_IS_DEFAULT_DEF (retval) | |
537 | && (bitmap_bit_p (current->split_bbs, | |
538 | gimple_bb (SSA_NAME_DEF_STMT (retval))->index) | |
539 | || gimple_bb (SSA_NAME_DEF_STMT (retval)) == return_bb)); | |
540 | else if (TREE_CODE (retval) == PARM_DECL) | |
541 | current->split_part_set_retval = false; | |
542 | else if (TREE_CODE (retval) == VAR_DECL | |
543 | || TREE_CODE (retval) == RESULT_DECL) | |
544 | current->split_part_set_retval | |
545 | = bitmap_bit_p (non_ssa_vars, DECL_UID (retval)); | |
546 | else | |
547 | current->split_part_set_retval = true; | |
548 | ||
28fc44f3 JJ |
549 | /* split_function fixes up at most one PHI non-virtual PHI node in return_bb, |
550 | for the return value. If there are other PHIs, give up. */ | |
551 | if (return_bb != EXIT_BLOCK_PTR) | |
552 | { | |
553 | gimple_stmt_iterator psi; | |
554 | ||
555 | for (psi = gsi_start_phis (return_bb); !gsi_end_p (psi); gsi_next (&psi)) | |
ea057359 | 556 | if (!virtual_operand_p (gimple_phi_result (gsi_stmt (psi))) |
28fc44f3 JJ |
557 | && !(retval |
558 | && current->split_part_set_retval | |
559 | && TREE_CODE (retval) == SSA_NAME | |
560 | && !DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)) | |
561 | && SSA_NAME_DEF_STMT (retval) == gsi_stmt (psi))) | |
562 | { | |
563 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
564 | fprintf (dump_file, | |
565 | " Refused: return bb has extra PHIs\n"); | |
566 | return; | |
567 | } | |
568 | } | |
569 | ||
570 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
571 | fprintf (dump_file, " Accepted!\n"); | |
572 | ||
3e485f62 JH |
573 | /* At the moment chose split point with lowest frequency and that leaves |
574 | out smallest size of header. | |
575 | In future we might re-consider this heuristics. */ | |
576 | if (!best_split_point.split_bbs | |
577 | || best_split_point.entry_bb->frequency > current->entry_bb->frequency | |
578 | || (best_split_point.entry_bb->frequency == current->entry_bb->frequency | |
579 | && best_split_point.split_size < current->split_size)) | |
580 | ||
581 | { | |
582 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
583 | fprintf (dump_file, " New best split point!\n"); | |
584 | if (best_split_point.ssa_names_to_pass) | |
585 | { | |
586 | BITMAP_FREE (best_split_point.ssa_names_to_pass); | |
587 | BITMAP_FREE (best_split_point.split_bbs); | |
588 | } | |
589 | best_split_point = *current; | |
590 | best_split_point.ssa_names_to_pass = BITMAP_ALLOC (NULL); | |
591 | bitmap_copy (best_split_point.ssa_names_to_pass, | |
592 | current->ssa_names_to_pass); | |
593 | best_split_point.split_bbs = BITMAP_ALLOC (NULL); | |
594 | bitmap_copy (best_split_point.split_bbs, current->split_bbs); | |
595 | } | |
596 | } | |
597 | ||
2094f1fc JH |
598 | /* Return basic block containing RETURN statement. We allow basic blocks |
599 | of the form: | |
600 | <retval> = tmp_var; | |
601 | return <retval> | |
602 | but return_bb can not be more complex than this. | |
603 | If nothing is found, return EXIT_BLOCK_PTR. | |
604 | ||
3e485f62 JH |
605 | When there are multiple RETURN statement, chose one with return value, |
606 | since that one is more likely shared by multiple code paths. | |
2094f1fc JH |
607 | |
608 | Return BB is special, because for function splitting it is the only | |
609 | basic block that is duplicated in between header and split part of the | |
610 | function. | |
611 | ||
3e485f62 JH |
612 | TODO: We might support multiple return blocks. */ |
613 | ||
614 | static basic_block | |
615 | find_return_bb (void) | |
616 | { | |
617 | edge e; | |
3e485f62 | 618 | basic_block return_bb = EXIT_BLOCK_PTR; |
68457901 JJ |
619 | gimple_stmt_iterator bsi; |
620 | bool found_return = false; | |
621 | tree retval = NULL_TREE; | |
3e485f62 | 622 | |
68457901 JJ |
623 | if (!single_pred_p (EXIT_BLOCK_PTR)) |
624 | return return_bb; | |
625 | ||
626 | e = single_pred_edge (EXIT_BLOCK_PTR); | |
627 | for (bsi = gsi_last_bb (e->src); !gsi_end_p (bsi); gsi_prev (&bsi)) | |
628 | { | |
629 | gimple stmt = gsi_stmt (bsi); | |
a348dc7f JJ |
630 | if (gimple_code (stmt) == GIMPLE_LABEL |
631 | || is_gimple_debug (stmt) | |
632 | || gimple_clobber_p (stmt)) | |
68457901 JJ |
633 | ; |
634 | else if (gimple_code (stmt) == GIMPLE_ASSIGN | |
635 | && found_return | |
636 | && gimple_assign_single_p (stmt) | |
637 | && (auto_var_in_fn_p (gimple_assign_rhs1 (stmt), | |
638 | current_function_decl) | |
639 | || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))) | |
640 | && retval == gimple_assign_lhs (stmt)) | |
641 | ; | |
642 | else if (gimple_code (stmt) == GIMPLE_RETURN) | |
643 | { | |
644 | found_return = true; | |
645 | retval = gimple_return_retval (stmt); | |
646 | } | |
647 | else | |
648 | break; | |
649 | } | |
650 | if (gsi_end_p (bsi) && found_return) | |
651 | return_bb = e->src; | |
3e485f62 | 652 | |
3e485f62 JH |
653 | return return_bb; |
654 | } | |
655 | ||
ed7656f6 | 656 | /* Given return basic block RETURN_BB, see where return value is really |
2094f1fc JH |
657 | stored. */ |
658 | static tree | |
659 | find_retval (basic_block return_bb) | |
660 | { | |
661 | gimple_stmt_iterator bsi; | |
662 | for (bsi = gsi_start_bb (return_bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
663 | if (gimple_code (gsi_stmt (bsi)) == GIMPLE_RETURN) | |
664 | return gimple_return_retval (gsi_stmt (bsi)); | |
a348dc7f JJ |
665 | else if (gimple_code (gsi_stmt (bsi)) == GIMPLE_ASSIGN |
666 | && !gimple_clobber_p (gsi_stmt (bsi))) | |
2094f1fc JH |
667 | return gimple_assign_rhs1 (gsi_stmt (bsi)); |
668 | return NULL; | |
669 | } | |
670 | ||
1802378d EB |
671 | /* Callback for walk_stmt_load_store_addr_ops. If T is non-SSA automatic |
672 | variable, mark it as used in bitmap passed via DATA. | |
3e485f62 JH |
673 | Return true when access to T prevents splitting the function. */ |
674 | ||
675 | static bool | |
1802378d | 676 | mark_nonssa_use (gimple stmt ATTRIBUTE_UNUSED, tree t, void *data) |
3e485f62 JH |
677 | { |
678 | t = get_base_address (t); | |
679 | ||
680 | if (!t || is_gimple_reg (t)) | |
681 | return false; | |
682 | ||
683 | /* At present we can't pass non-SSA arguments to split function. | |
684 | FIXME: this can be relaxed by passing references to arguments. */ | |
685 | if (TREE_CODE (t) == PARM_DECL) | |
686 | { | |
687 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1802378d EB |
688 | fprintf (dump_file, |
689 | "Cannot split: use of non-ssa function parameter.\n"); | |
3e485f62 JH |
690 | return true; |
691 | } | |
692 | ||
1802378d EB |
693 | if ((TREE_CODE (t) == VAR_DECL |
694 | && auto_var_in_fn_p (t, current_function_decl)) | |
695 | || TREE_CODE (t) == RESULT_DECL | |
696 | || TREE_CODE (t) == LABEL_DECL) | |
3e485f62 | 697 | bitmap_set_bit ((bitmap)data, DECL_UID (t)); |
241a2b9e | 698 | |
1802378d EB |
699 | /* For DECL_BY_REFERENCE, the return value is actually a pointer. We want |
700 | to pretend that the value pointed to is actual result decl. */ | |
701 | if ((TREE_CODE (t) == MEM_REF || INDIRECT_REF_P (t)) | |
241a2b9e | 702 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
70b5e7dc | 703 | && SSA_NAME_VAR (TREE_OPERAND (t, 0)) |
241a2b9e JH |
704 | && TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (t, 0))) == RESULT_DECL |
705 | && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) | |
1802378d EB |
706 | return |
707 | bitmap_bit_p ((bitmap)data, | |
708 | DECL_UID (DECL_RESULT (current_function_decl))); | |
709 | ||
3e485f62 JH |
710 | return false; |
711 | } | |
712 | ||
713 | /* Compute local properties of basic block BB we collect when looking for | |
714 | split points. We look for ssa defs and store them in SET_SSA_NAMES, | |
715 | for ssa uses and store them in USED_SSA_NAMES and for any non-SSA automatic | |
716 | vars stored in NON_SSA_VARS. | |
717 | ||
718 | When BB has edge to RETURN_BB, collect uses in RETURN_BB too. | |
719 | ||
720 | Return false when BB contains something that prevents it from being put into | |
721 | split function. */ | |
722 | ||
723 | static bool | |
724 | visit_bb (basic_block bb, basic_block return_bb, | |
725 | bitmap set_ssa_names, bitmap used_ssa_names, | |
726 | bitmap non_ssa_vars) | |
727 | { | |
728 | gimple_stmt_iterator bsi; | |
729 | edge e; | |
730 | edge_iterator ei; | |
731 | bool can_split = true; | |
732 | ||
733 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
734 | { | |
735 | gimple stmt = gsi_stmt (bsi); | |
736 | tree op; | |
737 | ssa_op_iter iter; | |
738 | tree decl; | |
739 | ||
740 | if (is_gimple_debug (stmt)) | |
741 | continue; | |
742 | ||
a348dc7f JJ |
743 | if (gimple_clobber_p (stmt)) |
744 | continue; | |
745 | ||
3e485f62 JH |
746 | /* FIXME: We can split regions containing EH. We can not however |
747 | split RESX, EH_DISPATCH and EH_POINTER referring to same region | |
748 | into different partitions. This would require tracking of | |
749 | EH regions and checking in consider_split_point if they | |
750 | are not used elsewhere. */ | |
1da7d8c0 | 751 | if (gimple_code (stmt) == GIMPLE_RESX) |
3e485f62 JH |
752 | { |
753 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1da7d8c0 | 754 | fprintf (dump_file, "Cannot split: resx.\n"); |
3e485f62 JH |
755 | can_split = false; |
756 | } | |
757 | if (gimple_code (stmt) == GIMPLE_EH_DISPATCH) | |
758 | { | |
759 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1802378d | 760 | fprintf (dump_file, "Cannot split: eh dispatch.\n"); |
3e485f62 JH |
761 | can_split = false; |
762 | } | |
763 | ||
764 | /* Check builtins that prevent splitting. */ | |
765 | if (gimple_code (stmt) == GIMPLE_CALL | |
766 | && (decl = gimple_call_fndecl (stmt)) != NULL_TREE | |
767 | && DECL_BUILT_IN (decl) | |
768 | && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) | |
769 | switch (DECL_FUNCTION_CODE (decl)) | |
770 | { | |
771 | /* FIXME: once we will allow passing non-parm values to split part, | |
772 | we need to be sure to handle correct builtin_stack_save and | |
773 | builtin_stack_restore. At the moment we are safe; there is no | |
774 | way to store builtin_stack_save result in non-SSA variable | |
775 | since all calls to those are compiler generated. */ | |
776 | case BUILT_IN_APPLY: | |
61e03ffc | 777 | case BUILT_IN_APPLY_ARGS: |
3e485f62 JH |
778 | case BUILT_IN_VA_START: |
779 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1802378d EB |
780 | fprintf (dump_file, |
781 | "Cannot split: builtin_apply and va_start.\n"); | |
3e485f62 JH |
782 | can_split = false; |
783 | break; | |
784 | case BUILT_IN_EH_POINTER: | |
785 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1802378d | 786 | fprintf (dump_file, "Cannot split: builtin_eh_pointer.\n"); |
3e485f62 JH |
787 | can_split = false; |
788 | break; | |
789 | default: | |
790 | break; | |
791 | } | |
792 | ||
793 | FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF) | |
794 | bitmap_set_bit (set_ssa_names, SSA_NAME_VERSION (op)); | |
795 | FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE) | |
796 | bitmap_set_bit (used_ssa_names, SSA_NAME_VERSION (op)); | |
797 | can_split &= !walk_stmt_load_store_addr_ops (stmt, non_ssa_vars, | |
798 | mark_nonssa_use, | |
799 | mark_nonssa_use, | |
800 | mark_nonssa_use); | |
801 | } | |
802 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
803 | { | |
804 | gimple stmt = gsi_stmt (bsi); | |
8b3057b3 | 805 | unsigned int i; |
3e485f62 | 806 | |
ea057359 | 807 | if (virtual_operand_p (gimple_phi_result (stmt))) |
3e485f62 | 808 | continue; |
8b3057b3 JH |
809 | bitmap_set_bit (set_ssa_names, |
810 | SSA_NAME_VERSION (gimple_phi_result (stmt))); | |
811 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
812 | { | |
813 | tree op = gimple_phi_arg_def (stmt, i); | |
814 | if (TREE_CODE (op) == SSA_NAME) | |
815 | bitmap_set_bit (used_ssa_names, SSA_NAME_VERSION (op)); | |
816 | } | |
3e485f62 JH |
817 | can_split &= !walk_stmt_load_store_addr_ops (stmt, non_ssa_vars, |
818 | mark_nonssa_use, | |
819 | mark_nonssa_use, | |
820 | mark_nonssa_use); | |
821 | } | |
ed7656f6 | 822 | /* Record also uses coming from PHI operand in return BB. */ |
3e485f62 JH |
823 | FOR_EACH_EDGE (e, ei, bb->succs) |
824 | if (e->dest == return_bb) | |
825 | { | |
3e485f62 JH |
826 | for (bsi = gsi_start_phis (return_bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
827 | { | |
828 | gimple stmt = gsi_stmt (bsi); | |
829 | tree op = gimple_phi_arg_def (stmt, e->dest_idx); | |
830 | ||
ea057359 | 831 | if (virtual_operand_p (gimple_phi_result (stmt))) |
3e485f62 | 832 | continue; |
3e485f62 JH |
833 | if (TREE_CODE (op) == SSA_NAME) |
834 | bitmap_set_bit (used_ssa_names, SSA_NAME_VERSION (op)); | |
835 | else | |
836 | can_split &= !mark_nonssa_use (stmt, op, non_ssa_vars); | |
837 | } | |
3e485f62 JH |
838 | } |
839 | return can_split; | |
840 | } | |
841 | ||
842 | /* Stack entry for recursive DFS walk in find_split_point. */ | |
843 | ||
844 | typedef struct | |
845 | { | |
846 | /* Basic block we are examining. */ | |
847 | basic_block bb; | |
848 | ||
849 | /* SSA names set and used by the BB and all BBs reachable | |
850 | from it via DFS walk. */ | |
851 | bitmap set_ssa_names, used_ssa_names; | |
852 | bitmap non_ssa_vars; | |
853 | ||
854 | /* All BBS visited from this BB via DFS walk. */ | |
855 | bitmap bbs_visited; | |
856 | ||
857 | /* Last examined edge in DFS walk. Since we walk unoriented graph, | |
ed7656f6 | 858 | the value is up to sum of incoming and outgoing edges of BB. */ |
3e485f62 JH |
859 | unsigned int edge_num; |
860 | ||
861 | /* Stack entry index of earliest BB reachable from current BB | |
ed7656f6 | 862 | or any BB visited later in DFS walk. */ |
3e485f62 JH |
863 | int earliest; |
864 | ||
865 | /* Overall time and size of all BBs reached from this BB in DFS walk. */ | |
866 | int overall_time, overall_size; | |
867 | ||
868 | /* When false we can not split on this BB. */ | |
869 | bool can_split; | |
870 | } stack_entry; | |
871 | DEF_VEC_O(stack_entry); | |
872 | DEF_VEC_ALLOC_O(stack_entry,heap); | |
873 | ||
874 | ||
875 | /* Find all articulations and call consider_split on them. | |
876 | OVERALL_TIME and OVERALL_SIZE is time and size of the function. | |
877 | ||
878 | We perform basic algorithm for finding an articulation in a graph | |
879 | created from CFG by considering it to be an unoriented graph. | |
880 | ||
881 | The articulation is discovered via DFS walk. We collect earliest | |
882 | basic block on stack that is reachable via backward edge. Articulation | |
883 | is any basic block such that there is no backward edge bypassing it. | |
884 | To reduce stack usage we maintain heap allocated stack in STACK vector. | |
885 | AUX pointer of BB is set to index it appears in the stack or -1 once | |
886 | it is visited and popped off the stack. | |
887 | ||
888 | The algorithm finds articulation after visiting the whole component | |
889 | reachable by it. This makes it convenient to collect information about | |
890 | the component used by consider_split. */ | |
891 | ||
892 | static void | |
893 | find_split_points (int overall_time, int overall_size) | |
894 | { | |
895 | stack_entry first; | |
896 | VEC(stack_entry, heap) *stack = NULL; | |
897 | basic_block bb; | |
898 | basic_block return_bb = find_return_bb (); | |
899 | struct split_point current; | |
900 | ||
901 | current.header_time = overall_time; | |
902 | current.header_size = overall_size; | |
903 | current.split_time = 0; | |
904 | current.split_size = 0; | |
905 | current.ssa_names_to_pass = BITMAP_ALLOC (NULL); | |
906 | ||
907 | first.bb = ENTRY_BLOCK_PTR; | |
908 | first.edge_num = 0; | |
909 | first.overall_time = 0; | |
910 | first.overall_size = 0; | |
911 | first.earliest = INT_MAX; | |
912 | first.set_ssa_names = 0; | |
913 | first.used_ssa_names = 0; | |
914 | first.bbs_visited = 0; | |
915 | VEC_safe_push (stack_entry, heap, stack, &first); | |
916 | ENTRY_BLOCK_PTR->aux = (void *)(intptr_t)-1; | |
917 | ||
918 | while (!VEC_empty (stack_entry, stack)) | |
919 | { | |
920 | stack_entry *entry = VEC_last (stack_entry, stack); | |
921 | ||
922 | /* We are walking an acyclic graph, so edge_num counts | |
923 | succ and pred edges together. However when considering | |
924 | articulation, we want to have processed everything reachable | |
925 | from articulation but nothing that reaches into it. */ | |
926 | if (entry->edge_num == EDGE_COUNT (entry->bb->succs) | |
927 | && entry->bb != ENTRY_BLOCK_PTR) | |
928 | { | |
929 | int pos = VEC_length (stack_entry, stack); | |
930 | entry->can_split &= visit_bb (entry->bb, return_bb, | |
931 | entry->set_ssa_names, | |
932 | entry->used_ssa_names, | |
933 | entry->non_ssa_vars); | |
934 | if (pos <= entry->earliest && !entry->can_split | |
935 | && dump_file && (dump_flags & TDF_DETAILS)) | |
936 | fprintf (dump_file, | |
937 | "found articulation at bb %i but can not split\n", | |
938 | entry->bb->index); | |
939 | if (pos <= entry->earliest && entry->can_split) | |
940 | { | |
941 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
942 | fprintf (dump_file, "found articulation at bb %i\n", | |
943 | entry->bb->index); | |
944 | current.entry_bb = entry->bb; | |
945 | current.ssa_names_to_pass = BITMAP_ALLOC (NULL); | |
946 | bitmap_and_compl (current.ssa_names_to_pass, | |
947 | entry->used_ssa_names, entry->set_ssa_names); | |
948 | current.header_time = overall_time - entry->overall_time; | |
949 | current.header_size = overall_size - entry->overall_size; | |
950 | current.split_time = entry->overall_time; | |
951 | current.split_size = entry->overall_size; | |
952 | current.split_bbs = entry->bbs_visited; | |
953 | consider_split (¤t, entry->non_ssa_vars, return_bb); | |
954 | BITMAP_FREE (current.ssa_names_to_pass); | |
955 | } | |
956 | } | |
957 | /* Do actual DFS walk. */ | |
958 | if (entry->edge_num | |
959 | < (EDGE_COUNT (entry->bb->succs) | |
960 | + EDGE_COUNT (entry->bb->preds))) | |
961 | { | |
962 | edge e; | |
963 | basic_block dest; | |
964 | if (entry->edge_num < EDGE_COUNT (entry->bb->succs)) | |
965 | { | |
966 | e = EDGE_SUCC (entry->bb, entry->edge_num); | |
967 | dest = e->dest; | |
968 | } | |
969 | else | |
970 | { | |
971 | e = EDGE_PRED (entry->bb, entry->edge_num | |
972 | - EDGE_COUNT (entry->bb->succs)); | |
973 | dest = e->src; | |
974 | } | |
975 | ||
976 | entry->edge_num++; | |
977 | ||
978 | /* New BB to visit, push it to the stack. */ | |
979 | if (dest != return_bb && dest != EXIT_BLOCK_PTR | |
980 | && !dest->aux) | |
981 | { | |
982 | stack_entry new_entry; | |
983 | ||
984 | new_entry.bb = dest; | |
985 | new_entry.edge_num = 0; | |
986 | new_entry.overall_time | |
987 | = VEC_index (bb_info, bb_info_vec, dest->index)->time; | |
988 | new_entry.overall_size | |
989 | = VEC_index (bb_info, bb_info_vec, dest->index)->size; | |
990 | new_entry.earliest = INT_MAX; | |
991 | new_entry.set_ssa_names = BITMAP_ALLOC (NULL); | |
992 | new_entry.used_ssa_names = BITMAP_ALLOC (NULL); | |
993 | new_entry.bbs_visited = BITMAP_ALLOC (NULL); | |
994 | new_entry.non_ssa_vars = BITMAP_ALLOC (NULL); | |
995 | new_entry.can_split = true; | |
996 | bitmap_set_bit (new_entry.bbs_visited, dest->index); | |
997 | VEC_safe_push (stack_entry, heap, stack, &new_entry); | |
998 | dest->aux = (void *)(intptr_t)VEC_length (stack_entry, stack); | |
999 | } | |
1000 | /* Back edge found, record the earliest point. */ | |
1001 | else if ((intptr_t)dest->aux > 0 | |
1002 | && (intptr_t)dest->aux < entry->earliest) | |
1003 | entry->earliest = (intptr_t)dest->aux; | |
1004 | } | |
ed7656f6 JJ |
1005 | /* We are done with examining the edges. Pop off the value from stack |
1006 | and merge stuff we accumulate during the walk. */ | |
3e485f62 JH |
1007 | else if (entry->bb != ENTRY_BLOCK_PTR) |
1008 | { | |
1009 | stack_entry *prev = VEC_index (stack_entry, stack, | |
1010 | VEC_length (stack_entry, stack) - 2); | |
1011 | ||
1012 | entry->bb->aux = (void *)(intptr_t)-1; | |
1013 | prev->can_split &= entry->can_split; | |
1014 | if (prev->set_ssa_names) | |
1015 | { | |
1016 | bitmap_ior_into (prev->set_ssa_names, entry->set_ssa_names); | |
1017 | bitmap_ior_into (prev->used_ssa_names, entry->used_ssa_names); | |
1018 | bitmap_ior_into (prev->bbs_visited, entry->bbs_visited); | |
1019 | bitmap_ior_into (prev->non_ssa_vars, entry->non_ssa_vars); | |
1020 | } | |
1021 | if (prev->earliest > entry->earliest) | |
1022 | prev->earliest = entry->earliest; | |
1023 | prev->overall_time += entry->overall_time; | |
1024 | prev->overall_size += entry->overall_size; | |
1025 | BITMAP_FREE (entry->set_ssa_names); | |
1026 | BITMAP_FREE (entry->used_ssa_names); | |
1027 | BITMAP_FREE (entry->bbs_visited); | |
1028 | BITMAP_FREE (entry->non_ssa_vars); | |
1029 | VEC_pop (stack_entry, stack); | |
1030 | } | |
1031 | else | |
1032 | VEC_pop (stack_entry, stack); | |
1033 | } | |
1034 | ENTRY_BLOCK_PTR->aux = NULL; | |
1035 | FOR_EACH_BB (bb) | |
1036 | bb->aux = NULL; | |
ff61e417 | 1037 | VEC_free (stack_entry, heap, stack); |
3e485f62 JH |
1038 | BITMAP_FREE (current.ssa_names_to_pass); |
1039 | } | |
1040 | ||
1041 | /* Split function at SPLIT_POINT. */ | |
1042 | ||
1043 | static void | |
1044 | split_function (struct split_point *split_point) | |
1045 | { | |
1046 | VEC (tree, heap) *args_to_pass = NULL; | |
201176d3 | 1047 | bitmap args_to_skip; |
3e485f62 JH |
1048 | tree parm; |
1049 | int num = 0; | |
201176d3 | 1050 | struct cgraph_node *node, *cur_node = cgraph_get_node (current_function_decl); |
3e485f62 JH |
1051 | basic_block return_bb = find_return_bb (); |
1052 | basic_block call_bb; | |
1053 | gimple_stmt_iterator gsi; | |
1054 | gimple call; | |
1055 | edge e; | |
1056 | edge_iterator ei; | |
1057 | tree retval = NULL, real_retval = NULL; | |
1058 | bool split_part_return_p = false; | |
1059 | gimple last_stmt = NULL; | |
371556ee | 1060 | unsigned int i; |
32244553 | 1061 | tree arg, ddef; |
3e485f62 JH |
1062 | |
1063 | if (dump_file) | |
1064 | { | |
1065 | fprintf (dump_file, "\n\nSplitting function at:\n"); | |
1066 | dump_split_point (dump_file, split_point); | |
1067 | } | |
1068 | ||
201176d3 MJ |
1069 | if (cur_node->local.can_change_signature) |
1070 | args_to_skip = BITMAP_ALLOC (NULL); | |
1071 | else | |
1072 | args_to_skip = NULL; | |
1073 | ||
3e485f62 JH |
1074 | /* Collect the parameters of new function and args_to_skip bitmap. */ |
1075 | for (parm = DECL_ARGUMENTS (current_function_decl); | |
910ad8de | 1076 | parm; parm = DECL_CHAIN (parm), num++) |
201176d3 MJ |
1077 | if (args_to_skip |
1078 | && (!is_gimple_reg (parm) | |
32244553 | 1079 | || (ddef = ssa_default_def (cfun, parm)) == NULL_TREE |
201176d3 | 1080 | || !bitmap_bit_p (split_point->ssa_names_to_pass, |
32244553 | 1081 | SSA_NAME_VERSION (ddef)))) |
3e485f62 JH |
1082 | bitmap_set_bit (args_to_skip, num); |
1083 | else | |
371556ee | 1084 | { |
86814190 MJ |
1085 | /* This parm might not have been used up to now, but is going to be |
1086 | used, hence register it. */ | |
86814190 | 1087 | if (is_gimple_reg (parm)) |
32244553 | 1088 | arg = get_or_create_ssa_default_def (cfun, parm); |
86814190 MJ |
1089 | else |
1090 | arg = parm; | |
201176d3 | 1091 | |
2b3c0885 RG |
1092 | if (!useless_type_conversion_p (DECL_ARG_TYPE (parm), TREE_TYPE (arg))) |
1093 | arg = fold_convert (DECL_ARG_TYPE (parm), arg); | |
371556ee JJ |
1094 | VEC_safe_push (tree, heap, args_to_pass, arg); |
1095 | } | |
3e485f62 JH |
1096 | |
1097 | /* See if the split function will return. */ | |
1098 | FOR_EACH_EDGE (e, ei, return_bb->preds) | |
1099 | if (bitmap_bit_p (split_point->split_bbs, e->src->index)) | |
1100 | break; | |
1101 | if (e) | |
1102 | split_part_return_p = true; | |
1103 | ||
241a2b9e JH |
1104 | /* Add return block to what will become the split function. |
1105 | We do not return; no return block is needed. */ | |
1106 | if (!split_part_return_p) | |
1107 | ; | |
1108 | /* We have no return block, so nothing is needed. */ | |
1109 | else if (return_bb == EXIT_BLOCK_PTR) | |
1110 | ; | |
1111 | /* When we do not want to return value, we need to construct | |
1112 | new return block with empty return statement. | |
1113 | FIXME: Once we are able to change return type, we should change function | |
1114 | to return void instead of just outputting function with undefined return | |
1115 | value. For structures this affects quality of codegen. */ | |
1116 | else if (!split_point->split_part_set_retval | |
1117 | && find_retval (return_bb)) | |
1118 | { | |
1119 | bool redirected = true; | |
1120 | basic_block new_return_bb = create_basic_block (NULL, 0, return_bb); | |
1121 | gimple_stmt_iterator gsi = gsi_start_bb (new_return_bb); | |
1122 | gsi_insert_after (&gsi, gimple_build_return (NULL), GSI_NEW_STMT); | |
1123 | while (redirected) | |
1124 | { | |
1125 | redirected = false; | |
1126 | FOR_EACH_EDGE (e, ei, return_bb->preds) | |
1127 | if (bitmap_bit_p (split_point->split_bbs, e->src->index)) | |
1128 | { | |
1129 | new_return_bb->count += e->count; | |
1130 | new_return_bb->frequency += EDGE_FREQUENCY (e); | |
1131 | redirect_edge_and_branch (e, new_return_bb); | |
1132 | redirected = true; | |
1133 | break; | |
1134 | } | |
1135 | } | |
1136 | e = make_edge (new_return_bb, EXIT_BLOCK_PTR, 0); | |
1137 | e->probability = REG_BR_PROB_BASE; | |
1138 | e->count = new_return_bb->count; | |
1139 | bitmap_set_bit (split_point->split_bbs, new_return_bb->index); | |
2e5e346d JL |
1140 | } |
1141 | /* When we pass around the value, use existing return block. */ | |
1142 | else | |
1143 | bitmap_set_bit (split_point->split_bbs, return_bb->index); | |
1144 | ||
1145 | /* If RETURN_BB has virtual operand PHIs, they must be removed and the | |
1146 | virtual operand marked for renaming as we change the CFG in a way that | |
cfef45c8 | 1147 | tree-inline is not able to compensate for. |
2e5e346d JL |
1148 | |
1149 | Note this can happen whether or not we have a return value. If we have | |
1150 | a return value, then RETURN_BB may have PHIs for real operands too. */ | |
1151 | if (return_bb != EXIT_BLOCK_PTR) | |
1152 | { | |
cfef45c8 | 1153 | bool phi_p = false; |
241a2b9e JH |
1154 | for (gsi = gsi_start_phis (return_bb); !gsi_end_p (gsi);) |
1155 | { | |
1156 | gimple stmt = gsi_stmt (gsi); | |
ea057359 | 1157 | if (!virtual_operand_p (gimple_phi_result (stmt))) |
2e5e346d JL |
1158 | { |
1159 | gsi_next (&gsi); | |
1160 | continue; | |
1161 | } | |
6b8c9df8 RG |
1162 | mark_virtual_phi_result_for_renaming (stmt); |
1163 | remove_phi_node (&gsi, true); | |
cfef45c8 | 1164 | phi_p = true; |
241a2b9e | 1165 | } |
cfef45c8 RG |
1166 | /* In reality we have to rename the reaching definition of the |
1167 | virtual operand at return_bb as we will eventually release it | |
1168 | when we remove the code region we outlined. | |
1169 | So we have to rename all immediate virtual uses of that region | |
1170 | if we didn't see a PHI definition yet. */ | |
1171 | /* ??? In real reality we want to set the reaching vdef of the | |
1172 | entry of the SESE region as the vuse of the call and the reaching | |
1173 | vdef of the exit of the SESE region as the vdef of the call. */ | |
1174 | if (!phi_p) | |
1175 | for (gsi = gsi_start_bb (return_bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1176 | { | |
1177 | gimple stmt = gsi_stmt (gsi); | |
1178 | if (gimple_vuse (stmt)) | |
1179 | { | |
1180 | gimple_set_vuse (stmt, NULL_TREE); | |
1181 | update_stmt (stmt); | |
1182 | } | |
1183 | if (gimple_vdef (stmt)) | |
1184 | break; | |
1185 | } | |
241a2b9e | 1186 | } |
3e485f62 JH |
1187 | |
1188 | /* Now create the actual clone. */ | |
1189 | rebuild_cgraph_edges (); | |
201176d3 | 1190 | node = cgraph_function_versioning (cur_node, NULL, NULL, args_to_skip, |
1a2c27e9 | 1191 | !split_part_return_p, |
3e485f62 | 1192 | split_point->split_bbs, |
2094f1fc | 1193 | split_point->entry_bb, "part"); |
d402c33d JH |
1194 | /* For usual cloning it is enough to clear builtin only when signature |
1195 | changes. For partial inlining we however can not expect the part | |
1196 | of builtin implementation to have same semantic as the whole. */ | |
960bfb69 | 1197 | if (DECL_BUILT_IN (node->symbol.decl)) |
d402c33d | 1198 | { |
960bfb69 JH |
1199 | DECL_BUILT_IN_CLASS (node->symbol.decl) = NOT_BUILT_IN; |
1200 | DECL_FUNCTION_CODE (node->symbol.decl) = (enum built_in_function) 0; | |
d402c33d | 1201 | } |
201176d3 | 1202 | cgraph_node_remove_callees (cur_node); |
3e485f62 | 1203 | if (!split_part_return_p) |
960bfb69 | 1204 | TREE_THIS_VOLATILE (node->symbol.decl) = 1; |
3e485f62 | 1205 | if (dump_file) |
960bfb69 | 1206 | dump_function_to_file (node->symbol.decl, dump_file, dump_flags); |
3e485f62 JH |
1207 | |
1208 | /* Create the basic block we place call into. It is the entry basic block | |
1209 | split after last label. */ | |
1210 | call_bb = split_point->entry_bb; | |
1211 | for (gsi = gsi_start_bb (call_bb); !gsi_end_p (gsi);) | |
1212 | if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL) | |
1213 | { | |
1214 | last_stmt = gsi_stmt (gsi); | |
1215 | gsi_next (&gsi); | |
1216 | } | |
1217 | else | |
1218 | break; | |
1219 | e = split_block (split_point->entry_bb, last_stmt); | |
1220 | remove_edge (e); | |
1221 | ||
1222 | /* Produce the call statement. */ | |
1223 | gsi = gsi_last_bb (call_bb); | |
2b3c0885 RG |
1224 | FOR_EACH_VEC_ELT (tree, args_to_pass, i, arg) |
1225 | if (!is_gimple_val (arg)) | |
1226 | { | |
1227 | arg = force_gimple_operand_gsi (&gsi, arg, true, NULL_TREE, | |
f6e52e91 | 1228 | false, GSI_CONTINUE_LINKING); |
2b3c0885 RG |
1229 | VEC_replace (tree, args_to_pass, i, arg); |
1230 | } | |
960bfb69 | 1231 | call = gimple_build_call_vec (node->symbol.decl, args_to_pass); |
3e485f62 JH |
1232 | gimple_set_block (call, DECL_INITIAL (current_function_decl)); |
1233 | ||
556e9ba0 JH |
1234 | /* We avoid address being taken on any variable used by split part, |
1235 | so return slot optimization is always possible. Moreover this is | |
1236 | required to make DECL_BY_REFERENCE work. */ | |
1237 | if (aggregate_value_p (DECL_RESULT (current_function_decl), | |
1238 | TREE_TYPE (current_function_decl))) | |
1239 | gimple_call_set_return_slot_opt (call, true); | |
1240 | ||
3e485f62 JH |
1241 | /* Update return value. This is bit tricky. When we do not return, |
1242 | do nothing. When we return we might need to update return_bb | |
1243 | or produce a new return statement. */ | |
1244 | if (!split_part_return_p) | |
1245 | gsi_insert_after (&gsi, call, GSI_NEW_STMT); | |
1246 | else | |
1247 | { | |
1248 | e = make_edge (call_bb, return_bb, | |
1249 | return_bb == EXIT_BLOCK_PTR ? 0 : EDGE_FALLTHRU); | |
1250 | e->count = call_bb->count; | |
1251 | e->probability = REG_BR_PROB_BASE; | |
6938f93f JH |
1252 | |
1253 | /* If there is return basic block, see what value we need to store | |
1254 | return value into and put call just before it. */ | |
3e485f62 JH |
1255 | if (return_bb != EXIT_BLOCK_PTR) |
1256 | { | |
2094f1fc | 1257 | real_retval = retval = find_retval (return_bb); |
6938f93f | 1258 | |
241a2b9e | 1259 | if (real_retval && split_point->split_part_set_retval) |
3e485f62 JH |
1260 | { |
1261 | gimple_stmt_iterator psi; | |
1262 | ||
6938f93f JH |
1263 | /* See if we need new SSA_NAME for the result. |
1264 | When DECL_BY_REFERENCE is true, retval is actually pointer to | |
1265 | return value and it is constant in whole function. */ | |
1266 | if (TREE_CODE (retval) == SSA_NAME | |
1267 | && !DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) | |
3e485f62 | 1268 | { |
070ecdfd | 1269 | retval = copy_ssa_name (retval, call); |
6938f93f JH |
1270 | |
1271 | /* See if there is PHI defining return value. */ | |
1272 | for (psi = gsi_start_phis (return_bb); | |
1273 | !gsi_end_p (psi); gsi_next (&psi)) | |
ea057359 | 1274 | if (!virtual_operand_p (gimple_phi_result (gsi_stmt (psi)))) |
6938f93f JH |
1275 | break; |
1276 | ||
1277 | /* When there is PHI, just update its value. */ | |
3e485f62 JH |
1278 | if (TREE_CODE (retval) == SSA_NAME |
1279 | && !gsi_end_p (psi)) | |
9e227d60 | 1280 | add_phi_arg (gsi_stmt (psi), retval, e, UNKNOWN_LOCATION); |
6938f93f JH |
1281 | /* Otherwise update the return BB itself. |
1282 | find_return_bb allows at most one assignment to return value, | |
1283 | so update first statement. */ | |
1284 | else | |
3e485f62 | 1285 | { |
2094f1fc JH |
1286 | gimple_stmt_iterator bsi; |
1287 | for (bsi = gsi_start_bb (return_bb); !gsi_end_p (bsi); | |
1288 | gsi_next (&bsi)) | |
1289 | if (gimple_code (gsi_stmt (bsi)) == GIMPLE_RETURN) | |
1290 | { | |
1291 | gimple_return_set_retval (gsi_stmt (bsi), retval); | |
1292 | break; | |
1293 | } | |
2e216592 JJ |
1294 | else if (gimple_code (gsi_stmt (bsi)) == GIMPLE_ASSIGN |
1295 | && !gimple_clobber_p (gsi_stmt (bsi))) | |
2094f1fc JH |
1296 | { |
1297 | gimple_assign_set_rhs1 (gsi_stmt (bsi), retval); | |
1298 | break; | |
1299 | } | |
1300 | update_stmt (gsi_stmt (bsi)); | |
3e485f62 JH |
1301 | } |
1302 | } | |
556e9ba0 | 1303 | if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) |
42b05b6e RG |
1304 | { |
1305 | gimple_call_set_lhs (call, build_simple_mem_ref (retval)); | |
1306 | gsi_insert_after (&gsi, call, GSI_NEW_STMT); | |
1307 | } | |
556e9ba0 | 1308 | else |
42b05b6e RG |
1309 | { |
1310 | tree restype; | |
1311 | restype = TREE_TYPE (DECL_RESULT (current_function_decl)); | |
1312 | gsi_insert_after (&gsi, call, GSI_NEW_STMT); | |
1313 | if (!useless_type_conversion_p (TREE_TYPE (retval), restype)) | |
1314 | { | |
1315 | gimple cpy; | |
1316 | tree tem = create_tmp_reg (restype, NULL); | |
1317 | tem = make_ssa_name (tem, call); | |
1318 | cpy = gimple_build_assign_with_ops (NOP_EXPR, retval, | |
1319 | tem, NULL_TREE); | |
1320 | gsi_insert_after (&gsi, cpy, GSI_NEW_STMT); | |
1321 | retval = tem; | |
1322 | } | |
1323 | gimple_call_set_lhs (call, retval); | |
1324 | update_stmt (call); | |
1325 | } | |
3e485f62 | 1326 | } |
42b05b6e RG |
1327 | else |
1328 | gsi_insert_after (&gsi, call, GSI_NEW_STMT); | |
3e485f62 | 1329 | } |
6938f93f JH |
1330 | /* We don't use return block (there is either no return in function or |
1331 | multiple of them). So create new basic block with return statement. | |
1332 | */ | |
3e485f62 JH |
1333 | else |
1334 | { | |
1335 | gimple ret; | |
241a2b9e JH |
1336 | if (split_point->split_part_set_retval |
1337 | && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl)))) | |
3e485f62 | 1338 | { |
4021f4a1 | 1339 | retval = DECL_RESULT (current_function_decl); |
8a9c1ae6 JH |
1340 | |
1341 | /* We use temporary register to hold value when aggregate_value_p | |
1342 | is false. Similarly for DECL_BY_REFERENCE we must avoid extra | |
1343 | copy. */ | |
1344 | if (!aggregate_value_p (retval, TREE_TYPE (current_function_decl)) | |
1345 | && !DECL_BY_REFERENCE (retval)) | |
1346 | retval = create_tmp_reg (TREE_TYPE (retval), NULL); | |
3e485f62 | 1347 | if (is_gimple_reg (retval)) |
6938f93f JH |
1348 | { |
1349 | /* When returning by reference, there is only one SSA name | |
1350 | assigned to RESULT_DECL (that is pointer to return value). | |
1351 | Look it up or create new one if it is missing. */ | |
1352 | if (DECL_BY_REFERENCE (retval)) | |
32244553 | 1353 | retval = get_or_create_ssa_default_def (cfun, retval); |
6938f93f JH |
1354 | /* Otherwise produce new SSA name for return value. */ |
1355 | else | |
1356 | retval = make_ssa_name (retval, call); | |
1357 | } | |
556e9ba0 JH |
1358 | if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) |
1359 | gimple_call_set_lhs (call, build_simple_mem_ref (retval)); | |
1360 | else | |
1361 | gimple_call_set_lhs (call, retval); | |
3e485f62 JH |
1362 | } |
1363 | gsi_insert_after (&gsi, call, GSI_NEW_STMT); | |
1364 | ret = gimple_build_return (retval); | |
1365 | gsi_insert_after (&gsi, ret, GSI_NEW_STMT); | |
1366 | } | |
1367 | } | |
1368 | free_dominance_info (CDI_DOMINATORS); | |
1369 | free_dominance_info (CDI_POST_DOMINATORS); | |
632b4f8e | 1370 | compute_inline_parameters (node, true); |
3e485f62 JH |
1371 | } |
1372 | ||
1373 | /* Execute function splitting pass. */ | |
1374 | ||
1375 | static unsigned int | |
1376 | execute_split_functions (void) | |
1377 | { | |
1378 | gimple_stmt_iterator bsi; | |
1379 | basic_block bb; | |
1380 | int overall_time = 0, overall_size = 0; | |
1381 | int todo = 0; | |
581985d7 | 1382 | struct cgraph_node *node = cgraph_get_node (current_function_decl); |
3e485f62 | 1383 | |
b2d2adc6 RG |
1384 | if (flags_from_decl_or_type (current_function_decl) |
1385 | & (ECF_NORETURN|ECF_MALLOC)) | |
3e485f62 JH |
1386 | { |
1387 | if (dump_file) | |
b2d2adc6 | 1388 | fprintf (dump_file, "Not splitting: noreturn/malloc function.\n"); |
3e485f62 JH |
1389 | return 0; |
1390 | } | |
1391 | if (MAIN_NAME_P (DECL_NAME (current_function_decl))) | |
1392 | { | |
1393 | if (dump_file) | |
1394 | fprintf (dump_file, "Not splitting: main function.\n"); | |
1395 | return 0; | |
1396 | } | |
1397 | /* This can be relaxed; function might become inlinable after splitting | |
1398 | away the uninlinable part. */ | |
a8da72b8 | 1399 | if (inline_edge_summary_vec && !inline_summary (node)->inlinable) |
3e485f62 JH |
1400 | { |
1401 | if (dump_file) | |
1402 | fprintf (dump_file, "Not splitting: not inlinable.\n"); | |
1403 | return 0; | |
1404 | } | |
960bfb69 | 1405 | if (DECL_DISREGARD_INLINE_LIMITS (node->symbol.decl)) |
3e485f62 JH |
1406 | { |
1407 | if (dump_file) | |
ed7656f6 | 1408 | fprintf (dump_file, "Not splitting: disregarding inline limits.\n"); |
3e485f62 JH |
1409 | return 0; |
1410 | } | |
1411 | /* This can be relaxed; most of versioning tests actually prevents | |
1412 | a duplication. */ | |
1413 | if (!tree_versionable_function_p (current_function_decl)) | |
1414 | { | |
1415 | if (dump_file) | |
1416 | fprintf (dump_file, "Not splitting: not versionable.\n"); | |
1417 | return 0; | |
1418 | } | |
1419 | /* FIXME: we could support this. */ | |
1420 | if (DECL_STRUCT_FUNCTION (current_function_decl)->static_chain_decl) | |
1421 | { | |
1422 | if (dump_file) | |
1423 | fprintf (dump_file, "Not splitting: nested function.\n"); | |
1424 | return 0; | |
1425 | } | |
3e485f62 JH |
1426 | |
1427 | /* See if it makes sense to try to split. | |
1428 | It makes sense to split if we inline, that is if we have direct calls to | |
1429 | handle or direct calls are possibly going to appear as result of indirect | |
cf9712cc JH |
1430 | inlining or LTO. Also handle -fprofile-generate as LTO to allow non-LTO |
1431 | training for LTO -fprofile-use build. | |
1432 | ||
3e485f62 JH |
1433 | Note that we are not completely conservative about disqualifying functions |
1434 | called once. It is possible that the caller is called more then once and | |
1435 | then inlining would still benefit. */ | |
1436 | if ((!node->callers || !node->callers->next_caller) | |
960bfb69 JH |
1437 | && !node->symbol.address_taken |
1438 | && (!flag_lto || !node->symbol.externally_visible)) | |
3e485f62 JH |
1439 | { |
1440 | if (dump_file) | |
1441 | fprintf (dump_file, "Not splitting: not called directly " | |
1442 | "or called once.\n"); | |
1443 | return 0; | |
1444 | } | |
1445 | ||
1446 | /* FIXME: We can actually split if splitting reduces call overhead. */ | |
1447 | if (!flag_inline_small_functions | |
1448 | && !DECL_DECLARED_INLINE_P (current_function_decl)) | |
1449 | { | |
1450 | if (dump_file) | |
1451 | fprintf (dump_file, "Not splitting: not autoinlining and function" | |
1452 | " is not inline.\n"); | |
1453 | return 0; | |
1454 | } | |
1455 | ||
b2e25729 BS |
1456 | /* Initialize bitmap to track forbidden calls. */ |
1457 | forbidden_dominators = BITMAP_ALLOC (NULL); | |
1458 | calculate_dominance_info (CDI_DOMINATORS); | |
1459 | ||
3e485f62 JH |
1460 | /* Compute local info about basic blocks and determine function size/time. */ |
1461 | VEC_safe_grow_cleared (bb_info, heap, bb_info_vec, last_basic_block + 1); | |
1462 | memset (&best_split_point, 0, sizeof (best_split_point)); | |
1463 | FOR_EACH_BB (bb) | |
1464 | { | |
1465 | int time = 0; | |
1466 | int size = 0; | |
1467 | int freq = compute_call_stmt_bb_frequency (current_function_decl, bb); | |
1468 | ||
1469 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1470 | fprintf (dump_file, "Basic block %i\n", bb->index); | |
1471 | ||
1472 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
1473 | { | |
1474 | int this_time, this_size; | |
1475 | gimple stmt = gsi_stmt (bsi); | |
1476 | ||
1477 | this_size = estimate_num_insns (stmt, &eni_size_weights); | |
1478 | this_time = estimate_num_insns (stmt, &eni_time_weights) * freq; | |
1479 | size += this_size; | |
1480 | time += this_time; | |
b2e25729 | 1481 | check_forbidden_calls (stmt); |
3e485f62 JH |
1482 | |
1483 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1484 | { | |
1485 | fprintf (dump_file, " freq:%6i size:%3i time:%3i ", | |
1486 | freq, this_size, this_time); | |
1487 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
1488 | } | |
1489 | } | |
1490 | overall_time += time; | |
1491 | overall_size += size; | |
1492 | VEC_index (bb_info, bb_info_vec, bb->index)->time = time; | |
1493 | VEC_index (bb_info, bb_info_vec, bb->index)->size = size; | |
1494 | } | |
1495 | find_split_points (overall_time, overall_size); | |
1496 | if (best_split_point.split_bbs) | |
1497 | { | |
1498 | split_function (&best_split_point); | |
1499 | BITMAP_FREE (best_split_point.ssa_names_to_pass); | |
1500 | BITMAP_FREE (best_split_point.split_bbs); | |
1501 | todo = TODO_update_ssa | TODO_cleanup_cfg; | |
1502 | } | |
b2e25729 | 1503 | BITMAP_FREE (forbidden_dominators); |
3e485f62 JH |
1504 | VEC_free (bb_info, heap, bb_info_vec); |
1505 | bb_info_vec = NULL; | |
1506 | return todo; | |
1507 | } | |
1508 | ||
cf9712cc JH |
1509 | /* Gate function splitting pass. When doing profile feedback, we want |
1510 | to execute the pass after profiling is read. So disable one in | |
1511 | early optimization. */ | |
1512 | ||
3e485f62 JH |
1513 | static bool |
1514 | gate_split_functions (void) | |
1515 | { | |
cf9712cc JH |
1516 | return (flag_partial_inlining |
1517 | && !profile_arc_flag && !flag_branch_probabilities); | |
3e485f62 JH |
1518 | } |
1519 | ||
1520 | struct gimple_opt_pass pass_split_functions = | |
1521 | { | |
1522 | { | |
1523 | GIMPLE_PASS, | |
1524 | "fnsplit", /* name */ | |
1525 | gate_split_functions, /* gate */ | |
1526 | execute_split_functions, /* execute */ | |
1527 | NULL, /* sub */ | |
1528 | NULL, /* next */ | |
1529 | 0, /* static_pass_number */ | |
1530 | TV_IPA_FNSPLIT, /* tv_id */ | |
1531 | PROP_cfg, /* properties_required */ | |
1532 | 0, /* properties_provided */ | |
1533 | 0, /* properties_destroyed */ | |
1534 | 0, /* todo_flags_start */ | |
40b6510f | 1535 | TODO_verify_all /* todo_flags_finish */ |
3e485f62 JH |
1536 | } |
1537 | }; | |
cf9712cc JH |
1538 | |
1539 | /* Gate feedback driven function splitting pass. | |
1540 | We don't need to split when profiling at all, we are producing | |
1541 | lousy code anyway. */ | |
1542 | ||
1543 | static bool | |
1544 | gate_feedback_split_functions (void) | |
1545 | { | |
1546 | return (flag_partial_inlining | |
1547 | && flag_branch_probabilities); | |
1548 | } | |
1549 | ||
1550 | /* Execute function splitting pass. */ | |
1551 | ||
1552 | static unsigned int | |
1553 | execute_feedback_split_functions (void) | |
1554 | { | |
1555 | unsigned int retval = execute_split_functions (); | |
1556 | if (retval) | |
1557 | retval |= TODO_rebuild_cgraph_edges; | |
1558 | return retval; | |
1559 | } | |
1560 | ||
1561 | struct gimple_opt_pass pass_feedback_split_functions = | |
1562 | { | |
1563 | { | |
1564 | GIMPLE_PASS, | |
1565 | "feedback_fnsplit", /* name */ | |
1566 | gate_feedback_split_functions, /* gate */ | |
1567 | execute_feedback_split_functions, /* execute */ | |
1568 | NULL, /* sub */ | |
1569 | NULL, /* next */ | |
1570 | 0, /* static_pass_number */ | |
1571 | TV_IPA_FNSPLIT, /* tv_id */ | |
1572 | PROP_cfg, /* properties_required */ | |
1573 | 0, /* properties_provided */ | |
1574 | 0, /* properties_destroyed */ | |
1575 | 0, /* todo_flags_start */ | |
40b6510f | 1576 | TODO_verify_all /* todo_flags_finish */ |
cf9712cc JH |
1577 | } |
1578 | }; |