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1 /* Inlining decision heuristics.
2 Copyright (C) 2003, 2004, 2007, 2008, 2009 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* Inlining decision heuristics
23 We separate inlining decisions from the inliner itself and store it
24 inside callgraph as so called inline plan. Refer to cgraph.c
25 documentation about particular representation of inline plans in the
26 callgraph.
28 There are three major parts of this file:
30 cgraph_mark_inline implementation
32 This function allows to mark given call inline and performs necessary
33 modifications of cgraph (production of the clones and updating overall
34 statistics)
36 inlining heuristics limits
38 These functions allow to check that particular inlining is allowed
39 by the limits specified by user (allowed function growth, overall unit
40 growth and so on).
42 inlining heuristics
44 This is implementation of IPA pass aiming to get as much of benefit
45 from inlining obeying the limits checked above.
47 The implementation of particular heuristics is separated from
48 the rest of code to make it easier to replace it with more complicated
49 implementation in the future. The rest of inlining code acts as a
50 library aimed to modify the callgraph and verify that the parameters
51 on code size growth fits.
53 To mark given call inline, use cgraph_mark_inline function, the
54 verification is performed by cgraph_default_inline_p and
55 cgraph_check_inline_limits.
57 The heuristics implements simple knapsack style algorithm ordering
58 all functions by their "profitability" (estimated by code size growth)
59 and inlining them in priority order.
61 cgraph_decide_inlining implements heuristics taking whole callgraph
62 into account, while cgraph_decide_inlining_incrementally considers
63 only one function at a time and is used by early inliner.
65 The inliner itself is split into several passes:
67 pass_inline_parameters
69 This pass computes local properties of functions that are used by inliner:
70 estimated function body size, whether function is inlinable at all and
71 stack frame consumption.
73 Before executing any of inliner passes, this local pass has to be applied
74 to each function in the callgraph (ie run as subpass of some earlier
75 IPA pass). The results are made out of date by any optimization applied
76 on the function body.
78 pass_early_inlining
80 Simple local inlining pass inlining callees into current function. This
81 pass makes no global whole compilation unit analysis and this when allowed
82 to do inlining expanding code size it might result in unbounded growth of
83 whole unit.
85 The pass is run during conversion into SSA form. Only functions already
86 converted into SSA form are inlined, so the conversion must happen in
87 topological order on the callgraph (that is maintained by pass manager).
88 The functions after inlining are early optimized so the early inliner sees
89 unoptimized function itself, but all considered callees are already
90 optimized allowing it to unfold abstraction penalty on C++ effectively and
91 cheaply.
93 pass_ipa_early_inlining
95 With profiling, the early inlining is also necessary to reduce
96 instrumentation costs on program with high abstraction penalty (doing
97 many redundant calls). This can't happen in parallel with early
98 optimization and profile instrumentation, because we would end up
99 re-instrumenting already instrumented function bodies we brought in via
100 inlining.
102 To avoid this, this pass is executed as IPA pass before profiling. It is
103 simple wrapper to pass_early_inlining and ensures first inlining.
105 pass_ipa_inline
107 This is the main pass implementing simple greedy algorithm to do inlining
108 of small functions that results in overall growth of compilation unit and
109 inlining of functions called once. The pass compute just so called inline
110 plan (representation of inlining to be done in callgraph) and unlike early
111 inlining it is not performing the inlining itself.
113 pass_apply_inline
115 This pass performs actual inlining according to pass_ipa_inline on given
116 function. Possible the function body before inlining is saved when it is
117 needed for further inlining later.
120 #include "config.h"
121 #include "system.h"
122 #include "coretypes.h"
123 #include "tm.h"
124 #include "tree.h"
125 #include "tree-inline.h"
126 #include "langhooks.h"
127 #include "flags.h"
128 #include "cgraph.h"
129 #include "diagnostic.h"
130 #include "timevar.h"
131 #include "params.h"
132 #include "fibheap.h"
133 #include "intl.h"
134 #include "tree-pass.h"
135 #include "hashtab.h"
136 #include "coverage.h"
137 #include "ggc.h"
138 #include "tree-flow.h"
139 #include "rtl.h"
140 #include "ipa-prop.h"
141 #include "except.h"
143 #define MAX_TIME 1000000000
145 /* Mode incremental inliner operate on:
147 In ALWAYS_INLINE only functions marked
148 always_inline are inlined. This mode is used after detecting cycle during
149 flattening.
151 In SIZE mode, only functions that reduce function body size after inlining
152 are inlined, this is used during early inlining.
154 in ALL mode, everything is inlined. This is used during flattening. */
155 enum inlining_mode {
156 INLINE_NONE = 0,
157 INLINE_ALWAYS_INLINE,
158 INLINE_SIZE_NORECURSIVE,
159 INLINE_SIZE,
160 INLINE_ALL
162 static bool
163 cgraph_decide_inlining_incrementally (struct cgraph_node *, enum inlining_mode,
164 int);
167 /* Statistics we collect about inlining algorithm. */
168 static int ncalls_inlined;
169 static int nfunctions_inlined;
170 static int overall_size;
171 static gcov_type max_count, max_benefit;
173 /* Holders of ipa cgraph hooks: */
174 static struct cgraph_node_hook_list *function_insertion_hook_holder;
176 static inline struct inline_summary *
177 inline_summary (struct cgraph_node *node)
179 return &node->local.inline_summary;
182 /* Estimate self time of the function after inlining WHAT into TO. */
184 static int
185 cgraph_estimate_time_after_inlining (int frequency, struct cgraph_node *to,
186 struct cgraph_node *what)
188 gcov_type time = (((gcov_type)what->global.time
189 - inline_summary (what)->time_inlining_benefit)
190 * frequency + CGRAPH_FREQ_BASE / 2) / CGRAPH_FREQ_BASE
191 + to->global.time;
192 if (time < 0)
193 time = 0;
194 if (time > MAX_TIME)
195 time = MAX_TIME;
196 return time;
199 /* Estimate self time of the function after inlining WHAT into TO. */
201 static int
202 cgraph_estimate_size_after_inlining (int times, struct cgraph_node *to,
203 struct cgraph_node *what)
205 int size = (what->global.size - inline_summary (what)->size_inlining_benefit) * times + to->global.size;
206 gcc_assert (size >= 0);
207 return size;
210 /* E is expected to be an edge being inlined. Clone destination node of
211 the edge and redirect it to the new clone.
212 DUPLICATE is used for bookkeeping on whether we are actually creating new
213 clones or re-using node originally representing out-of-line function call.
215 void
216 cgraph_clone_inlined_nodes (struct cgraph_edge *e, bool duplicate,
217 bool update_original)
219 HOST_WIDE_INT peak;
221 if (duplicate)
223 /* We may eliminate the need for out-of-line copy to be output.
224 In that case just go ahead and re-use it. */
225 if (!e->callee->callers->next_caller
226 && cgraph_can_remove_if_no_direct_calls_p (e->callee)
227 && !cgraph_new_nodes)
229 gcc_assert (!e->callee->global.inlined_to);
230 if (e->callee->analyzed)
232 overall_size -= e->callee->global.size;
233 nfunctions_inlined++;
235 duplicate = false;
236 e->callee->local.externally_visible = false;
238 else
240 struct cgraph_node *n;
241 n = cgraph_clone_node (e->callee, e->count, e->frequency, e->loop_nest,
242 update_original, NULL);
243 cgraph_redirect_edge_callee (e, n);
247 if (e->caller->global.inlined_to)
248 e->callee->global.inlined_to = e->caller->global.inlined_to;
249 else
250 e->callee->global.inlined_to = e->caller;
251 e->callee->global.stack_frame_offset
252 = e->caller->global.stack_frame_offset
253 + inline_summary (e->caller)->estimated_self_stack_size;
254 peak = e->callee->global.stack_frame_offset
255 + inline_summary (e->callee)->estimated_self_stack_size;
256 if (e->callee->global.inlined_to->global.estimated_stack_size < peak)
257 e->callee->global.inlined_to->global.estimated_stack_size = peak;
259 /* Recursively clone all bodies. */
260 for (e = e->callee->callees; e; e = e->next_callee)
261 if (!e->inline_failed)
262 cgraph_clone_inlined_nodes (e, duplicate, update_original);
265 /* Mark edge E as inlined and update callgraph accordingly. UPDATE_ORIGINAL
266 specify whether profile of original function should be updated. If any new
267 indirect edges are discovered in the process, add them to NEW_EDGES, unless
268 it is NULL. Return true iff any new callgraph edges were discovered as a
269 result of inlining. */
271 static bool
272 cgraph_mark_inline_edge (struct cgraph_edge *e, bool update_original,
273 VEC (cgraph_edge_p, heap) **new_edges)
275 int old_size = 0, new_size = 0;
276 struct cgraph_node *to = NULL, *what;
277 struct cgraph_edge *curr = e;
278 int freq;
279 bool duplicate = false;
280 int orig_size = e->callee->global.size;
282 gcc_assert (e->inline_failed);
283 e->inline_failed = CIF_OK;
285 if (!e->callee->global.inlined)
286 DECL_POSSIBLY_INLINED (e->callee->decl) = true;
287 e->callee->global.inlined = true;
289 if (e->callee->callers->next_caller
290 || !cgraph_can_remove_if_no_direct_calls_p (e->callee))
291 duplicate = true;
292 cgraph_clone_inlined_nodes (e, true, update_original);
294 what = e->callee;
296 freq = e->frequency;
297 /* Now update size of caller and all functions caller is inlined into. */
298 for (;e && !e->inline_failed; e = e->caller->callers)
300 to = e->caller;
301 old_size = e->caller->global.size;
302 new_size = cgraph_estimate_size_after_inlining (1, to, what);
303 to->global.size = new_size;
304 to->global.time = cgraph_estimate_time_after_inlining (freq, to, what);
306 gcc_assert (what->global.inlined_to == to);
307 if (new_size > old_size)
308 overall_size += new_size - old_size;
309 if (!duplicate)
310 overall_size -= orig_size;
311 ncalls_inlined++;
313 if (flag_indirect_inlining && !flag_wpa)
314 return ipa_propagate_indirect_call_infos (curr, new_edges);
315 else
316 return false;
319 /* Mark all calls of EDGE->CALLEE inlined into EDGE->CALLER.
320 Return following unredirected edge in the list of callers
321 of EDGE->CALLEE */
323 static struct cgraph_edge *
324 cgraph_mark_inline (struct cgraph_edge *edge)
326 struct cgraph_node *to = edge->caller;
327 struct cgraph_node *what = edge->callee;
328 struct cgraph_edge *e, *next;
330 gcc_assert (!edge->call_stmt_cannot_inline_p);
331 /* Look for all calls, mark them inline and clone recursively
332 all inlined functions. */
333 for (e = what->callers; e; e = next)
335 next = e->next_caller;
336 if (e->caller == to && e->inline_failed)
338 cgraph_mark_inline_edge (e, true, NULL);
339 if (e == edge)
340 edge = next;
344 return edge;
347 /* Estimate the growth caused by inlining NODE into all callees. */
349 static int
350 cgraph_estimate_growth (struct cgraph_node *node)
352 int growth = 0;
353 struct cgraph_edge *e;
354 bool self_recursive = false;
356 if (node->global.estimated_growth != INT_MIN)
357 return node->global.estimated_growth;
359 for (e = node->callers; e; e = e->next_caller)
361 if (e->caller == node)
362 self_recursive = true;
363 if (e->inline_failed)
364 growth += (cgraph_estimate_size_after_inlining (1, e->caller, node)
365 - e->caller->global.size);
368 /* ??? Wrong for non-trivially self recursive functions or cases where
369 we decide to not inline for different reasons, but it is not big deal
370 as in that case we will keep the body around, but we will also avoid
371 some inlining. */
372 if (cgraph_only_called_directly_p (node)
373 && !DECL_EXTERNAL (node->decl) && !self_recursive)
374 growth -= node->global.size;
376 node->global.estimated_growth = growth;
377 return growth;
380 /* Return false when inlining WHAT into TO is not good idea
381 as it would cause too large growth of function bodies.
382 When ONE_ONLY is true, assume that only one call site is going
383 to be inlined, otherwise figure out how many call sites in
384 TO calls WHAT and verify that all can be inlined.
387 static bool
388 cgraph_check_inline_limits (struct cgraph_node *to, struct cgraph_node *what,
389 cgraph_inline_failed_t *reason, bool one_only)
391 int times = 0;
392 struct cgraph_edge *e;
393 int newsize;
394 int limit;
395 HOST_WIDE_INT stack_size_limit, inlined_stack;
397 if (one_only)
398 times = 1;
399 else
400 for (e = to->callees; e; e = e->next_callee)
401 if (e->callee == what)
402 times++;
404 if (to->global.inlined_to)
405 to = to->global.inlined_to;
407 /* When inlining large function body called once into small function,
408 take the inlined function as base for limiting the growth. */
409 if (inline_summary (to)->self_size > inline_summary(what)->self_size)
410 limit = inline_summary (to)->self_size;
411 else
412 limit = inline_summary (what)->self_size;
414 limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100;
416 /* Check the size after inlining against the function limits. But allow
417 the function to shrink if it went over the limits by forced inlining. */
418 newsize = cgraph_estimate_size_after_inlining (times, to, what);
419 if (newsize >= to->global.size
420 && newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS)
421 && newsize > limit)
423 if (reason)
424 *reason = CIF_LARGE_FUNCTION_GROWTH_LIMIT;
425 return false;
428 stack_size_limit = inline_summary (to)->estimated_self_stack_size;
430 stack_size_limit += stack_size_limit * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH) / 100;
432 inlined_stack = (to->global.stack_frame_offset
433 + inline_summary (to)->estimated_self_stack_size
434 + what->global.estimated_stack_size);
435 if (inlined_stack > stack_size_limit
436 && inlined_stack > PARAM_VALUE (PARAM_LARGE_STACK_FRAME))
438 if (reason)
439 *reason = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT;
440 return false;
442 return true;
445 /* Return true when function N is small enough to be inlined. */
447 static bool
448 cgraph_default_inline_p (struct cgraph_node *n, cgraph_inline_failed_t *reason)
450 tree decl = n->decl;
452 if (!flag_inline_small_functions && !DECL_DECLARED_INLINE_P (decl))
454 if (reason)
455 *reason = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
456 return false;
459 if (!n->analyzed)
461 if (reason)
462 *reason = CIF_BODY_NOT_AVAILABLE;
463 return false;
466 if (DECL_DECLARED_INLINE_P (decl))
468 if (n->global.size >= MAX_INLINE_INSNS_SINGLE)
470 if (reason)
471 *reason = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
472 return false;
475 else
477 if (n->global.size >= MAX_INLINE_INSNS_AUTO)
479 if (reason)
480 *reason = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
481 return false;
485 return true;
488 /* Return true when inlining WHAT would create recursive inlining.
489 We call recursive inlining all cases where same function appears more than
490 once in the single recursion nest path in the inline graph. */
492 static bool
493 cgraph_recursive_inlining_p (struct cgraph_node *to,
494 struct cgraph_node *what,
495 cgraph_inline_failed_t *reason)
497 bool recursive;
498 if (to->global.inlined_to)
499 recursive = what->decl == to->global.inlined_to->decl;
500 else
501 recursive = what->decl == to->decl;
502 /* Marking recursive function inline has sane semantic and thus we should
503 not warn on it. */
504 if (recursive && reason)
505 *reason = (what->local.disregard_inline_limits
506 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
507 return recursive;
510 /* A cost model driving the inlining heuristics in a way so the edges with
511 smallest badness are inlined first. After each inlining is performed
512 the costs of all caller edges of nodes affected are recomputed so the
513 metrics may accurately depend on values such as number of inlinable callers
514 of the function or function body size. */
516 static int
517 cgraph_edge_badness (struct cgraph_edge *edge)
519 gcov_type badness;
520 int growth =
521 cgraph_estimate_size_after_inlining (1, edge->caller, edge->callee);
523 growth -= edge->caller->global.size;
525 /* Always prefer inlining saving code size. */
526 if (growth <= 0)
527 badness = INT_MIN - growth;
529 /* When profiling is available, base priorities -(#calls / growth).
530 So we optimize for overall number of "executed" inlined calls. */
531 else if (max_count)
532 badness = ((int)((double)edge->count * INT_MIN / max_count / (max_benefit + 1))
533 * (inline_summary (edge->callee)->time_inlining_benefit + 1)) / growth;
535 /* When function local profile is available, base priorities on
536 growth / frequency, so we optimize for overall frequency of inlined
537 calls. This is not too accurate since while the call might be frequent
538 within function, the function itself is infrequent.
540 Other objective to optimize for is number of different calls inlined.
541 We add the estimated growth after inlining all functions to bias the
542 priorities slightly in this direction (so fewer times called functions
543 of the same size gets priority). */
544 else if (flag_guess_branch_prob)
546 int div = edge->frequency * 100 / CGRAPH_FREQ_BASE + 1;
547 badness = growth * 10000;
548 div *= MIN (100 * inline_summary (edge->callee)->time_inlining_benefit
549 / (edge->callee->global.time + 1) + 1, 100);
552 /* Decrease badness if call is nested. */
553 /* Compress the range so we don't overflow. */
554 if (div > 10000)
555 div = 10000 + ceil_log2 (div) - 8;
556 if (div < 1)
557 div = 1;
558 if (badness > 0)
559 badness /= div;
560 badness += cgraph_estimate_growth (edge->callee);
561 if (badness > INT_MAX)
562 badness = INT_MAX;
564 /* When function local profile is not available or it does not give
565 useful information (ie frequency is zero), base the cost on
566 loop nest and overall size growth, so we optimize for overall number
567 of functions fully inlined in program. */
568 else
570 int nest = MIN (edge->loop_nest, 8);
571 badness = cgraph_estimate_growth (edge->callee) * 256;
573 /* Decrease badness if call is nested. */
574 if (badness > 0)
575 badness >>= nest;
576 else
578 badness <<= nest;
581 /* Make recursive inlining happen always after other inlining is done. */
582 if (cgraph_recursive_inlining_p (edge->caller, edge->callee, NULL))
583 return badness + 1;
584 else
585 return badness;
588 /* Recompute heap nodes for each of caller edge. */
590 static void
591 update_caller_keys (fibheap_t heap, struct cgraph_node *node,
592 bitmap updated_nodes)
594 struct cgraph_edge *edge;
595 cgraph_inline_failed_t failed_reason;
597 if (!node->local.inlinable || node->local.disregard_inline_limits
598 || node->global.inlined_to)
599 return;
600 if (bitmap_bit_p (updated_nodes, node->uid))
601 return;
602 bitmap_set_bit (updated_nodes, node->uid);
603 node->global.estimated_growth = INT_MIN;
605 if (!node->local.inlinable)
606 return;
607 /* Prune out edges we won't inline into anymore. */
608 if (!cgraph_default_inline_p (node, &failed_reason))
610 for (edge = node->callers; edge; edge = edge->next_caller)
611 if (edge->aux)
613 fibheap_delete_node (heap, (fibnode_t) edge->aux);
614 edge->aux = NULL;
615 if (edge->inline_failed)
616 edge->inline_failed = failed_reason;
618 return;
621 for (edge = node->callers; edge; edge = edge->next_caller)
622 if (edge->inline_failed)
624 int badness = cgraph_edge_badness (edge);
625 if (edge->aux)
627 fibnode_t n = (fibnode_t) edge->aux;
628 gcc_assert (n->data == edge);
629 if (n->key == badness)
630 continue;
632 /* fibheap_replace_key only increase the keys. */
633 if (fibheap_replace_key (heap, n, badness))
634 continue;
635 fibheap_delete_node (heap, (fibnode_t) edge->aux);
637 edge->aux = fibheap_insert (heap, badness, edge);
641 /* Recompute heap nodes for each of caller edges of each of callees. */
643 static void
644 update_callee_keys (fibheap_t heap, struct cgraph_node *node,
645 bitmap updated_nodes)
647 struct cgraph_edge *e;
648 node->global.estimated_growth = INT_MIN;
650 for (e = node->callees; e; e = e->next_callee)
651 if (e->inline_failed)
652 update_caller_keys (heap, e->callee, updated_nodes);
653 else if (!e->inline_failed)
654 update_callee_keys (heap, e->callee, updated_nodes);
657 /* Enqueue all recursive calls from NODE into priority queue depending on
658 how likely we want to recursively inline the call. */
660 static void
661 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
662 fibheap_t heap)
664 static int priority;
665 struct cgraph_edge *e;
666 for (e = where->callees; e; e = e->next_callee)
667 if (e->callee == node)
669 /* When profile feedback is available, prioritize by expected number
670 of calls. Without profile feedback we maintain simple queue
671 to order candidates via recursive depths. */
672 fibheap_insert (heap,
673 !max_count ? priority++
674 : -(e->count / ((max_count + (1<<24) - 1) / (1<<24))),
677 for (e = where->callees; e; e = e->next_callee)
678 if (!e->inline_failed)
679 lookup_recursive_calls (node, e->callee, heap);
682 /* Decide on recursive inlining: in the case function has recursive calls,
683 inline until body size reaches given argument. If any new indirect edges
684 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
685 is NULL. */
687 static bool
688 cgraph_decide_recursive_inlining (struct cgraph_node *node,
689 VEC (cgraph_edge_p, heap) **new_edges)
691 int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO);
692 int max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO);
693 int probability = PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY);
694 fibheap_t heap;
695 struct cgraph_edge *e;
696 struct cgraph_node *master_clone, *next;
697 int depth = 0;
698 int n = 0;
700 if (optimize_function_for_size_p (DECL_STRUCT_FUNCTION (node->decl))
701 || (!flag_inline_functions && !DECL_DECLARED_INLINE_P (node->decl)))
702 return false;
704 if (DECL_DECLARED_INLINE_P (node->decl))
706 limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE);
707 max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH);
710 /* Make sure that function is small enough to be considered for inlining. */
711 if (!max_depth
712 || cgraph_estimate_size_after_inlining (1, node, node) >= limit)
713 return false;
714 heap = fibheap_new ();
715 lookup_recursive_calls (node, node, heap);
716 if (fibheap_empty (heap))
718 fibheap_delete (heap);
719 return false;
722 if (dump_file)
723 fprintf (dump_file,
724 " Performing recursive inlining on %s\n",
725 cgraph_node_name (node));
727 /* We need original clone to copy around. */
728 master_clone = cgraph_clone_node (node, node->count, CGRAPH_FREQ_BASE, 1,
729 false, NULL);
730 master_clone->needed = true;
731 for (e = master_clone->callees; e; e = e->next_callee)
732 if (!e->inline_failed)
733 cgraph_clone_inlined_nodes (e, true, false);
735 /* Do the inlining and update list of recursive call during process. */
736 while (!fibheap_empty (heap)
737 && (cgraph_estimate_size_after_inlining (1, node, master_clone)
738 <= limit))
740 struct cgraph_edge *curr
741 = (struct cgraph_edge *) fibheap_extract_min (heap);
742 struct cgraph_node *cnode;
744 depth = 1;
745 for (cnode = curr->caller;
746 cnode->global.inlined_to; cnode = cnode->callers->caller)
747 if (node->decl == curr->callee->decl)
748 depth++;
749 if (depth > max_depth)
751 if (dump_file)
752 fprintf (dump_file,
753 " maximal depth reached\n");
754 continue;
757 if (max_count)
759 if (!cgraph_maybe_hot_edge_p (curr))
761 if (dump_file)
762 fprintf (dump_file, " Not inlining cold call\n");
763 continue;
765 if (curr->count * 100 / node->count < probability)
767 if (dump_file)
768 fprintf (dump_file,
769 " Probability of edge is too small\n");
770 continue;
774 if (dump_file)
776 fprintf (dump_file,
777 " Inlining call of depth %i", depth);
778 if (node->count)
780 fprintf (dump_file, " called approx. %.2f times per call",
781 (double)curr->count / node->count);
783 fprintf (dump_file, "\n");
785 cgraph_redirect_edge_callee (curr, master_clone);
786 cgraph_mark_inline_edge (curr, false, new_edges);
787 lookup_recursive_calls (node, curr->callee, heap);
788 n++;
790 if (!fibheap_empty (heap) && dump_file)
791 fprintf (dump_file, " Recursive inlining growth limit met.\n");
793 fibheap_delete (heap);
794 if (dump_file)
795 fprintf (dump_file,
796 "\n Inlined %i times, body grown from size %i to %i, time %i to %i\n", n,
797 master_clone->global.size, node->global.size,
798 master_clone->global.time, node->global.time);
800 /* Remove master clone we used for inlining. We rely that clones inlined
801 into master clone gets queued just before master clone so we don't
802 need recursion. */
803 for (node = cgraph_nodes; node != master_clone;
804 node = next)
806 next = node->next;
807 if (node->global.inlined_to == master_clone)
808 cgraph_remove_node (node);
810 cgraph_remove_node (master_clone);
811 /* FIXME: Recursive inlining actually reduces number of calls of the
812 function. At this place we should probably walk the function and
813 inline clones and compensate the counts accordingly. This probably
814 doesn't matter much in practice. */
815 return n > 0;
818 /* Set inline_failed for all callers of given function to REASON. */
820 static void
821 cgraph_set_inline_failed (struct cgraph_node *node,
822 cgraph_inline_failed_t reason)
824 struct cgraph_edge *e;
826 if (dump_file)
827 fprintf (dump_file, "Inlining failed: %s\n",
828 cgraph_inline_failed_string (reason));
829 for (e = node->callers; e; e = e->next_caller)
830 if (e->inline_failed)
831 e->inline_failed = reason;
834 /* Given whole compilation unit estimate of INSNS, compute how large we can
835 allow the unit to grow. */
836 static int
837 compute_max_insns (int insns)
839 int max_insns = insns;
840 if (max_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS))
841 max_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS);
843 return ((HOST_WIDEST_INT) max_insns
844 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100);
847 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
848 static void
849 add_new_edges_to_heap (fibheap_t heap, VEC (cgraph_edge_p, heap) *new_edges)
851 while (VEC_length (cgraph_edge_p, new_edges) > 0)
853 struct cgraph_edge *edge = VEC_pop (cgraph_edge_p, new_edges);
855 gcc_assert (!edge->aux);
856 edge->aux = fibheap_insert (heap, cgraph_edge_badness (edge), edge);
861 /* We use greedy algorithm for inlining of small functions:
862 All inline candidates are put into prioritized heap based on estimated
863 growth of the overall number of instructions and then update the estimates.
865 INLINED and INLINED_CALEES are just pointers to arrays large enough
866 to be passed to cgraph_inlined_into and cgraph_inlined_callees. */
868 static void
869 cgraph_decide_inlining_of_small_functions (void)
871 struct cgraph_node *node;
872 struct cgraph_edge *edge;
873 cgraph_inline_failed_t failed_reason;
874 fibheap_t heap = fibheap_new ();
875 bitmap updated_nodes = BITMAP_ALLOC (NULL);
876 int min_size, max_size;
877 VEC (cgraph_edge_p, heap) *new_indirect_edges = NULL;
879 if (flag_indirect_inlining && !flag_wpa)
880 new_indirect_edges = VEC_alloc (cgraph_edge_p, heap, 8);
882 if (dump_file)
883 fprintf (dump_file, "\nDeciding on smaller functions:\n");
885 /* Put all inline candidates into the heap. */
887 for (node = cgraph_nodes; node; node = node->next)
889 if (!node->local.inlinable || !node->callers
890 || node->local.disregard_inline_limits)
891 continue;
892 if (dump_file)
893 fprintf (dump_file, "Considering inline candidate %s.\n", cgraph_node_name (node));
895 node->global.estimated_growth = INT_MIN;
896 if (!cgraph_default_inline_p (node, &failed_reason))
898 cgraph_set_inline_failed (node, failed_reason);
899 continue;
902 for (edge = node->callers; edge; edge = edge->next_caller)
903 if (edge->inline_failed)
905 gcc_assert (!edge->aux);
906 edge->aux = fibheap_insert (heap, cgraph_edge_badness (edge), edge);
910 max_size = compute_max_insns (overall_size);
911 min_size = overall_size;
913 while (overall_size <= max_size
914 && (edge = (struct cgraph_edge *) fibheap_extract_min (heap)))
916 int old_size = overall_size;
917 struct cgraph_node *where;
918 int growth =
919 cgraph_estimate_size_after_inlining (1, edge->caller, edge->callee);
920 cgraph_inline_failed_t not_good = CIF_OK;
922 growth -= edge->caller->global.size;
924 if (dump_file)
926 fprintf (dump_file,
927 "\nConsidering %s with %i size\n",
928 cgraph_node_name (edge->callee),
929 edge->callee->global.size);
930 fprintf (dump_file,
931 " to be inlined into %s in %s:%i\n"
932 " Estimated growth after inlined into all callees is %+i insns.\n"
933 " Estimated badness is %i, frequency %.2f.\n",
934 cgraph_node_name (edge->caller),
935 gimple_filename ((const_gimple) edge->call_stmt),
936 gimple_lineno ((const_gimple) edge->call_stmt),
937 cgraph_estimate_growth (edge->callee),
938 cgraph_edge_badness (edge),
939 edge->frequency / (double)CGRAPH_FREQ_BASE);
940 if (edge->count)
941 fprintf (dump_file," Called "HOST_WIDEST_INT_PRINT_DEC"x\n", edge->count);
943 gcc_assert (edge->aux);
944 edge->aux = NULL;
945 if (!edge->inline_failed)
946 continue;
948 /* When not having profile info ready we don't weight by any way the
949 position of call in procedure itself. This means if call of
950 function A from function B seems profitable to inline, the recursive
951 call of function A in inline copy of A in B will look profitable too
952 and we end up inlining until reaching maximal function growth. This
953 is not good idea so prohibit the recursive inlining.
955 ??? When the frequencies are taken into account we might not need this
956 restriction.
958 We need to be cureful here, in some testcases, e.g. directivec.c in
959 libcpp, we can estimate self recursive function to have negative growth
960 for inlining completely.
962 if (!edge->count)
964 where = edge->caller;
965 while (where->global.inlined_to)
967 if (where->decl == edge->callee->decl)
968 break;
969 where = where->callers->caller;
971 if (where->global.inlined_to)
973 edge->inline_failed
974 = (edge->callee->local.disregard_inline_limits
975 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
976 if (dump_file)
977 fprintf (dump_file, " inline_failed:Recursive inlining performed only for function itself.\n");
978 continue;
982 if (!cgraph_maybe_hot_edge_p (edge))
983 not_good = CIF_UNLIKELY_CALL;
984 if (!flag_inline_functions
985 && !DECL_DECLARED_INLINE_P (edge->callee->decl))
986 not_good = CIF_NOT_DECLARED_INLINED;
987 if (optimize_function_for_size_p (DECL_STRUCT_FUNCTION(edge->caller->decl)))
988 not_good = CIF_OPTIMIZING_FOR_SIZE;
989 if (not_good && growth > 0 && cgraph_estimate_growth (edge->callee) > 0)
991 if (!cgraph_recursive_inlining_p (edge->caller, edge->callee,
992 &edge->inline_failed))
994 edge->inline_failed = not_good;
995 if (dump_file)
996 fprintf (dump_file, " inline_failed:%s.\n",
997 cgraph_inline_failed_string (edge->inline_failed));
999 continue;
1001 if (!cgraph_default_inline_p (edge->callee, &edge->inline_failed))
1003 if (!cgraph_recursive_inlining_p (edge->caller, edge->callee,
1004 &edge->inline_failed))
1006 if (dump_file)
1007 fprintf (dump_file, " inline_failed:%s.\n",
1008 cgraph_inline_failed_string (edge->inline_failed));
1010 continue;
1012 if (!tree_can_inline_p (edge))
1014 if (dump_file)
1015 fprintf (dump_file, " inline_failed:%s.\n",
1016 cgraph_inline_failed_string (edge->inline_failed));
1017 continue;
1019 if (cgraph_recursive_inlining_p (edge->caller, edge->callee,
1020 &edge->inline_failed))
1022 where = edge->caller;
1023 if (where->global.inlined_to)
1024 where = where->global.inlined_to;
1025 if (!cgraph_decide_recursive_inlining (where,
1026 flag_indirect_inlining && !flag_wpa
1027 ? &new_indirect_edges : NULL))
1028 continue;
1029 if (flag_indirect_inlining && !flag_wpa)
1030 add_new_edges_to_heap (heap, new_indirect_edges);
1031 update_callee_keys (heap, where, updated_nodes);
1033 else
1035 struct cgraph_node *callee;
1036 if (edge->call_stmt_cannot_inline_p
1037 || !cgraph_check_inline_limits (edge->caller, edge->callee,
1038 &edge->inline_failed, true))
1040 if (dump_file)
1041 fprintf (dump_file, " Not inlining into %s:%s.\n",
1042 cgraph_node_name (edge->caller),
1043 cgraph_inline_failed_string (edge->inline_failed));
1044 continue;
1046 callee = edge->callee;
1047 cgraph_mark_inline_edge (edge, true, &new_indirect_edges);
1048 if (flag_indirect_inlining && !flag_wpa)
1049 add_new_edges_to_heap (heap, new_indirect_edges);
1051 update_callee_keys (heap, callee, updated_nodes);
1053 where = edge->caller;
1054 if (where->global.inlined_to)
1055 where = where->global.inlined_to;
1057 /* Our profitability metric can depend on local properties
1058 such as number of inlinable calls and size of the function body.
1059 After inlining these properties might change for the function we
1060 inlined into (since it's body size changed) and for the functions
1061 called by function we inlined (since number of it inlinable callers
1062 might change). */
1063 update_caller_keys (heap, where, updated_nodes);
1064 bitmap_clear (updated_nodes);
1066 if (dump_file)
1068 fprintf (dump_file,
1069 " Inlined into %s which now has size %i and self time %i,"
1070 "net change of %+i.\n",
1071 cgraph_node_name (edge->caller),
1072 edge->caller->global.time,
1073 edge->caller->global.size,
1074 overall_size - old_size);
1076 if (min_size > overall_size)
1078 min_size = overall_size;
1079 max_size = compute_max_insns (min_size);
1081 if (dump_file)
1082 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
1085 while ((edge = (struct cgraph_edge *) fibheap_extract_min (heap)) != NULL)
1087 gcc_assert (edge->aux);
1088 edge->aux = NULL;
1089 if (!edge->callee->local.disregard_inline_limits && edge->inline_failed
1090 && !cgraph_recursive_inlining_p (edge->caller, edge->callee,
1091 &edge->inline_failed))
1092 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
1095 if (new_indirect_edges)
1096 VEC_free (cgraph_edge_p, heap, new_indirect_edges);
1097 fibheap_delete (heap);
1098 BITMAP_FREE (updated_nodes);
1101 /* Decide on the inlining. We do so in the topological order to avoid
1102 expenses on updating data structures. */
1104 static unsigned int
1105 cgraph_decide_inlining (void)
1107 struct cgraph_node *node;
1108 int nnodes;
1109 struct cgraph_node **order =
1110 XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1111 int old_size = 0;
1112 int i;
1113 bool redo_always_inline = true;
1114 int initial_size = 0;
1116 cgraph_remove_function_insertion_hook (function_insertion_hook_holder);
1117 if (in_lto_p && flag_indirect_inlining && !flag_wpa)
1118 ipa_update_after_lto_read ();
1120 max_count = 0;
1121 max_benefit = 0;
1122 for (node = cgraph_nodes; node; node = node->next)
1123 if (node->analyzed)
1125 struct cgraph_edge *e;
1127 gcc_assert (inline_summary (node)->self_size == node->global.size);
1128 initial_size += node->global.size;
1129 for (e = node->callees; e; e = e->next_callee)
1130 if (max_count < e->count)
1131 max_count = e->count;
1132 if (max_benefit < inline_summary (node)->time_inlining_benefit)
1133 max_benefit = inline_summary (node)->time_inlining_benefit;
1135 gcc_assert (in_lto_p
1136 || !max_count
1137 || (profile_info && flag_branch_probabilities));
1138 overall_size = initial_size;
1140 nnodes = cgraph_postorder (order);
1142 if (dump_file)
1143 fprintf (dump_file,
1144 "\nDeciding on inlining. Starting with size %i.\n",
1145 initial_size);
1147 for (node = cgraph_nodes; node; node = node->next)
1148 node->aux = 0;
1150 if (dump_file)
1151 fprintf (dump_file, "\nInlining always_inline functions:\n");
1153 /* In the first pass mark all always_inline edges. Do this with a priority
1154 so none of our later choices will make this impossible. */
1155 while (redo_always_inline)
1157 redo_always_inline = false;
1158 for (i = nnodes - 1; i >= 0; i--)
1160 struct cgraph_edge *e, *next;
1162 node = order[i];
1164 /* Handle nodes to be flattened, but don't update overall unit
1165 size. */
1166 if (lookup_attribute ("flatten",
1167 DECL_ATTRIBUTES (node->decl)) != NULL)
1169 if (dump_file)
1170 fprintf (dump_file,
1171 "Flattening %s\n", cgraph_node_name (node));
1172 cgraph_decide_inlining_incrementally (node, INLINE_ALL, 0);
1175 if (!node->local.disregard_inline_limits)
1176 continue;
1177 if (dump_file)
1178 fprintf (dump_file,
1179 "\nConsidering %s size:%i (always inline)\n",
1180 cgraph_node_name (node), node->global.size);
1181 old_size = overall_size;
1182 for (e = node->callers; e; e = next)
1184 next = e->next_caller;
1185 if (!e->inline_failed || e->call_stmt_cannot_inline_p)
1186 continue;
1187 if (cgraph_recursive_inlining_p (e->caller, e->callee,
1188 &e->inline_failed))
1189 continue;
1190 if (!tree_can_inline_p (e))
1191 continue;
1192 if (cgraph_mark_inline_edge (e, true, NULL))
1193 redo_always_inline = true;
1194 if (dump_file)
1195 fprintf (dump_file,
1196 " Inlined into %s which now has size %i.\n",
1197 cgraph_node_name (e->caller),
1198 e->caller->global.size);
1200 /* Inlining self recursive function might introduce new calls to
1201 themselves we didn't see in the loop above. Fill in the proper
1202 reason why inline failed. */
1203 for (e = node->callers; e; e = e->next_caller)
1204 if (e->inline_failed)
1205 e->inline_failed = CIF_RECURSIVE_INLINING;
1206 if (dump_file)
1207 fprintf (dump_file,
1208 " Inlined for a net change of %+i size.\n",
1209 overall_size - old_size);
1213 cgraph_decide_inlining_of_small_functions ();
1215 if (flag_inline_functions_called_once)
1217 if (dump_file)
1218 fprintf (dump_file, "\nDeciding on functions called once:\n");
1220 /* And finally decide what functions are called once. */
1221 for (i = nnodes - 1; i >= 0; i--)
1223 node = order[i];
1225 if (node->callers
1226 && !node->callers->next_caller
1227 && cgraph_only_called_directly_p (node)
1228 && node->local.inlinable
1229 && node->callers->inline_failed
1230 && node->callers->caller != node
1231 && node->callers->caller->global.inlined_to != node
1232 && !node->callers->call_stmt_cannot_inline_p
1233 && !DECL_EXTERNAL (node->decl)
1234 && !DECL_COMDAT (node->decl))
1236 cgraph_inline_failed_t reason;
1237 old_size = overall_size;
1238 if (dump_file)
1240 fprintf (dump_file,
1241 "\nConsidering %s size %i.\n",
1242 cgraph_node_name (node), node->global.size);
1243 fprintf (dump_file,
1244 " Called once from %s %i insns.\n",
1245 cgraph_node_name (node->callers->caller),
1246 node->callers->caller->global.size);
1249 if (cgraph_check_inline_limits (node->callers->caller, node,
1250 &reason, false))
1252 cgraph_mark_inline (node->callers);
1253 if (dump_file)
1254 fprintf (dump_file,
1255 " Inlined into %s which now has %i size"
1256 " for a net change of %+i size.\n",
1257 cgraph_node_name (node->callers->caller),
1258 node->callers->caller->global.size,
1259 overall_size - old_size);
1261 else
1263 if (dump_file)
1264 fprintf (dump_file,
1265 " Not inlining: %s.\n",
1266 cgraph_inline_failed_string (reason));
1272 /* Free ipa-prop structures if they are no longer needed. */
1273 if (flag_indirect_inlining && !flag_wpa)
1274 free_all_ipa_structures_after_iinln ();
1276 if (dump_file)
1277 fprintf (dump_file,
1278 "\nInlined %i calls, eliminated %i functions, "
1279 "size %i turned to %i size.\n\n",
1280 ncalls_inlined, nfunctions_inlined, initial_size,
1281 overall_size);
1282 free (order);
1283 return 0;
1286 /* Try to inline edge E from incremental inliner. MODE specifies mode
1287 of inliner.
1289 We are detecting cycles by storing mode of inliner into cgraph_node last
1290 time we visited it in the recursion. In general when mode is set, we have
1291 recursive inlining, but as an special case, we want to try harder inline
1292 ALWAYS_INLINE functions: consider callgraph a->b->c->b, with a being
1293 flatten, b being always inline. Flattening 'a' will collapse
1294 a->b->c before hitting cycle. To accommodate always inline, we however
1295 need to inline a->b->c->b.
1297 So after hitting cycle first time, we switch into ALWAYS_INLINE mode and
1298 stop inlining only after hitting ALWAYS_INLINE in ALWAY_INLINE mode. */
1299 static bool
1300 try_inline (struct cgraph_edge *e, enum inlining_mode mode, int depth)
1302 struct cgraph_node *callee = e->callee;
1303 enum inlining_mode callee_mode = (enum inlining_mode) (size_t) callee->aux;
1304 bool always_inline = e->callee->local.disregard_inline_limits;
1305 bool inlined = false;
1307 /* We've hit cycle? */
1308 if (callee_mode)
1310 /* It is first time we see it and we are not in ALWAY_INLINE only
1311 mode yet. and the function in question is always_inline. */
1312 if (always_inline && mode != INLINE_ALWAYS_INLINE)
1314 if (dump_file)
1316 indent_to (dump_file, depth);
1317 fprintf (dump_file,
1318 "Hit cycle in %s, switching to always inline only.\n",
1319 cgraph_node_name (callee));
1321 mode = INLINE_ALWAYS_INLINE;
1323 /* Otherwise it is time to give up. */
1324 else
1326 if (dump_file)
1328 indent_to (dump_file, depth);
1329 fprintf (dump_file,
1330 "Not inlining %s into %s to avoid cycle.\n",
1331 cgraph_node_name (callee),
1332 cgraph_node_name (e->caller));
1334 e->inline_failed = (e->callee->local.disregard_inline_limits
1335 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
1336 return false;
1340 callee->aux = (void *)(size_t) mode;
1341 if (dump_file)
1343 indent_to (dump_file, depth);
1344 fprintf (dump_file, " Inlining %s into %s.\n",
1345 cgraph_node_name (e->callee),
1346 cgraph_node_name (e->caller));
1348 if (e->inline_failed)
1350 cgraph_mark_inline (e);
1352 /* In order to fully inline always_inline functions, we need to
1353 recurse here, since the inlined functions might not be processed by
1354 incremental inlining at all yet.
1356 Also flattening needs to be done recursively. */
1358 if (mode == INLINE_ALL || always_inline)
1359 cgraph_decide_inlining_incrementally (e->callee, mode, depth + 1);
1360 inlined = true;
1362 callee->aux = (void *)(size_t) callee_mode;
1363 return inlined;
1366 /* Return true when N is leaf function. Accept cheap (pure&const) builtins
1367 in leaf functions. */
1368 static bool
1369 leaf_node_p (struct cgraph_node *n)
1371 struct cgraph_edge *e;
1372 for (e = n->callees; e; e = e->next_callee)
1373 if (!DECL_BUILT_IN (e->callee->decl)
1374 || (!TREE_READONLY (e->callee->decl)
1375 || DECL_PURE_P (e->callee->decl)))
1376 return false;
1377 return true;
1380 /* Decide on the inlining. We do so in the topological order to avoid
1381 expenses on updating data structures.
1382 DEPTH is depth of recursion, used only for debug output. */
1384 static bool
1385 cgraph_decide_inlining_incrementally (struct cgraph_node *node,
1386 enum inlining_mode mode,
1387 int depth)
1389 struct cgraph_edge *e;
1390 bool inlined = false;
1391 cgraph_inline_failed_t failed_reason;
1392 enum inlining_mode old_mode;
1394 #ifdef ENABLE_CHECKING
1395 verify_cgraph_node (node);
1396 #endif
1398 old_mode = (enum inlining_mode) (size_t)node->aux;
1400 if (mode != INLINE_ALWAYS_INLINE && mode != INLINE_SIZE_NORECURSIVE
1401 && lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) != NULL)
1403 if (dump_file)
1405 indent_to (dump_file, depth);
1406 fprintf (dump_file, "Flattening %s\n", cgraph_node_name (node));
1408 mode = INLINE_ALL;
1411 node->aux = (void *)(size_t) mode;
1413 /* First of all look for always inline functions. */
1414 if (mode != INLINE_SIZE_NORECURSIVE)
1415 for (e = node->callees; e; e = e->next_callee)
1417 if (!e->callee->local.disregard_inline_limits
1418 && (mode != INLINE_ALL || !e->callee->local.inlinable))
1419 continue;
1420 if (e->call_stmt_cannot_inline_p)
1421 continue;
1422 /* When the edge is already inlined, we just need to recurse into
1423 it in order to fully flatten the leaves. */
1424 if (!e->inline_failed && mode == INLINE_ALL)
1426 inlined |= try_inline (e, mode, depth);
1427 continue;
1429 if (dump_file)
1431 indent_to (dump_file, depth);
1432 fprintf (dump_file,
1433 "Considering to always inline inline candidate %s.\n",
1434 cgraph_node_name (e->callee));
1436 if (cgraph_recursive_inlining_p (node, e->callee, &e->inline_failed))
1438 if (dump_file)
1440 indent_to (dump_file, depth);
1441 fprintf (dump_file, "Not inlining: recursive call.\n");
1443 continue;
1445 if (!tree_can_inline_p (e))
1447 if (dump_file)
1449 indent_to (dump_file, depth);
1450 fprintf (dump_file,
1451 "Not inlining: %s",
1452 cgraph_inline_failed_string (e->inline_failed));
1454 continue;
1456 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
1457 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->callee->decl)))
1459 if (dump_file)
1461 indent_to (dump_file, depth);
1462 fprintf (dump_file, "Not inlining: SSA form does not match.\n");
1464 continue;
1466 if (!e->callee->analyzed)
1468 if (dump_file)
1470 indent_to (dump_file, depth);
1471 fprintf (dump_file,
1472 "Not inlining: Function body no longer available.\n");
1474 continue;
1476 inlined |= try_inline (e, mode, depth);
1479 /* Now do the automatic inlining. */
1480 if (mode != INLINE_ALL && mode != INLINE_ALWAYS_INLINE)
1481 for (e = node->callees; e; e = e->next_callee)
1483 int allowed_growth = 0;
1484 if (!e->callee->local.inlinable
1485 || !e->inline_failed
1486 || e->callee->local.disregard_inline_limits)
1487 continue;
1488 if (dump_file)
1489 fprintf (dump_file, "Considering inline candidate %s.\n",
1490 cgraph_node_name (e->callee));
1491 if (cgraph_recursive_inlining_p (node, e->callee, &e->inline_failed))
1493 if (dump_file)
1495 indent_to (dump_file, depth);
1496 fprintf (dump_file, "Not inlining: recursive call.\n");
1498 continue;
1500 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
1501 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->callee->decl)))
1503 if (dump_file)
1505 indent_to (dump_file, depth);
1506 fprintf (dump_file, "Not inlining: SSA form does not match.\n");
1508 continue;
1511 if (cgraph_maybe_hot_edge_p (e) && leaf_node_p (e->callee)
1512 && optimize_function_for_speed_p (cfun))
1513 allowed_growth = PARAM_VALUE (PARAM_EARLY_INLINING_INSNS);
1515 /* When the function body would grow and inlining the function won't
1516 eliminate the need for offline copy of the function, don't inline.
1518 if (((mode == INLINE_SIZE || mode == INLINE_SIZE_NORECURSIVE)
1519 || (!flag_inline_functions
1520 && !DECL_DECLARED_INLINE_P (e->callee->decl)))
1521 && (cgraph_estimate_size_after_inlining (1, e->caller, e->callee)
1522 > e->caller->global.size + allowed_growth)
1523 && cgraph_estimate_growth (e->callee) > allowed_growth)
1525 if (dump_file)
1527 indent_to (dump_file, depth);
1528 fprintf (dump_file,
1529 "Not inlining: code size would grow by %i.\n",
1530 cgraph_estimate_size_after_inlining (1, e->caller,
1531 e->callee)
1532 - e->caller->global.size);
1534 continue;
1536 if (!cgraph_check_inline_limits (node, e->callee, &e->inline_failed,
1537 false)
1538 || e->call_stmt_cannot_inline_p)
1540 if (dump_file)
1542 indent_to (dump_file, depth);
1543 fprintf (dump_file, "Not inlining: %s.\n",
1544 cgraph_inline_failed_string (e->inline_failed));
1546 continue;
1548 if (!e->callee->analyzed)
1550 if (dump_file)
1552 indent_to (dump_file, depth);
1553 fprintf (dump_file,
1554 "Not inlining: Function body no longer available.\n");
1556 continue;
1558 if (!tree_can_inline_p (e))
1560 if (dump_file)
1562 indent_to (dump_file, depth);
1563 fprintf (dump_file,
1564 "Not inlining: %s.",
1565 cgraph_inline_failed_string (e->inline_failed));
1567 continue;
1569 if (cgraph_default_inline_p (e->callee, &failed_reason))
1570 inlined |= try_inline (e, mode, depth);
1572 node->aux = (void *)(size_t) old_mode;
1573 return inlined;
1576 /* Because inlining might remove no-longer reachable nodes, we need to
1577 keep the array visible to garbage collector to avoid reading collected
1578 out nodes. */
1579 static int nnodes;
1580 static GTY ((length ("nnodes"))) struct cgraph_node **order;
1582 /* Do inlining of small functions. Doing so early helps profiling and other
1583 passes to be somewhat more effective and avoids some code duplication in
1584 later real inlining pass for testcases with very many function calls. */
1585 static unsigned int
1586 cgraph_early_inlining (void)
1588 struct cgraph_node *node = cgraph_node (current_function_decl);
1589 unsigned int todo = 0;
1590 int iterations = 0;
1592 if (sorrycount || errorcount)
1593 return 0;
1594 while (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS)
1595 && cgraph_decide_inlining_incrementally (node,
1596 iterations
1597 ? INLINE_SIZE_NORECURSIVE : INLINE_SIZE, 0))
1599 timevar_push (TV_INTEGRATION);
1600 todo |= optimize_inline_calls (current_function_decl);
1601 iterations++;
1602 timevar_pop (TV_INTEGRATION);
1604 if (dump_file)
1605 fprintf (dump_file, "Iterations: %i\n", iterations);
1606 cfun->always_inline_functions_inlined = true;
1607 return todo;
1610 /* When inlining shall be performed. */
1611 static bool
1612 cgraph_gate_early_inlining (void)
1614 return flag_early_inlining;
1617 struct gimple_opt_pass pass_early_inline =
1620 GIMPLE_PASS,
1621 "einline", /* name */
1622 cgraph_gate_early_inlining, /* gate */
1623 cgraph_early_inlining, /* execute */
1624 NULL, /* sub */
1625 NULL, /* next */
1626 0, /* static_pass_number */
1627 TV_INLINE_HEURISTICS, /* tv_id */
1628 0, /* properties_required */
1629 0, /* properties_provided */
1630 0, /* properties_destroyed */
1631 0, /* todo_flags_start */
1632 TODO_dump_func /* todo_flags_finish */
1636 /* When inlining shall be performed. */
1637 static bool
1638 cgraph_gate_ipa_early_inlining (void)
1640 return (flag_early_inlining
1641 && !in_lto_p
1642 && (flag_branch_probabilities || flag_test_coverage
1643 || profile_arc_flag));
1646 /* IPA pass wrapper for early inlining pass. We need to run early inlining
1647 before tree profiling so we have stand alone IPA pass for doing so. */
1648 struct simple_ipa_opt_pass pass_ipa_early_inline =
1651 SIMPLE_IPA_PASS,
1652 "einline_ipa", /* name */
1653 cgraph_gate_ipa_early_inlining, /* gate */
1654 NULL, /* execute */
1655 NULL, /* sub */
1656 NULL, /* next */
1657 0, /* static_pass_number */
1658 TV_INLINE_HEURISTICS, /* tv_id */
1659 0, /* properties_required */
1660 0, /* properties_provided */
1661 0, /* properties_destroyed */
1662 0, /* todo_flags_start */
1663 TODO_dump_cgraph /* todo_flags_finish */
1667 /* See if statement might disappear after inlining. We are not terribly
1668 sophisficated, basically looking for simple abstraction penalty wrappers. */
1670 static bool
1671 likely_eliminated_by_inlining_p (gimple stmt)
1673 enum gimple_code code = gimple_code (stmt);
1674 switch (code)
1676 case GIMPLE_RETURN:
1677 return true;
1678 case GIMPLE_ASSIGN:
1679 if (gimple_num_ops (stmt) != 2)
1680 return false;
1682 /* Casts of parameters, loads from parameters passed by reference
1683 and stores to return value or parameters are probably free after
1684 inlining. */
1685 if (gimple_assign_rhs_code (stmt) == CONVERT_EXPR
1686 || gimple_assign_rhs_code (stmt) == NOP_EXPR
1687 || gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR
1688 || gimple_assign_rhs_class (stmt) == GIMPLE_SINGLE_RHS)
1690 tree rhs = gimple_assign_rhs1 (stmt);
1691 tree lhs = gimple_assign_lhs (stmt);
1692 tree inner_rhs = rhs;
1693 tree inner_lhs = lhs;
1694 bool rhs_free = false;
1695 bool lhs_free = false;
1697 while (handled_component_p (inner_lhs) || TREE_CODE (inner_lhs) == INDIRECT_REF)
1698 inner_lhs = TREE_OPERAND (inner_lhs, 0);
1699 while (handled_component_p (inner_rhs)
1700 || TREE_CODE (inner_rhs) == ADDR_EXPR || TREE_CODE (inner_rhs) == INDIRECT_REF)
1701 inner_rhs = TREE_OPERAND (inner_rhs, 0);
1704 if (TREE_CODE (inner_rhs) == PARM_DECL
1705 || (TREE_CODE (inner_rhs) == SSA_NAME
1706 && SSA_NAME_IS_DEFAULT_DEF (inner_rhs)
1707 && TREE_CODE (SSA_NAME_VAR (inner_rhs)) == PARM_DECL))
1708 rhs_free = true;
1709 if (rhs_free && is_gimple_reg (lhs))
1710 lhs_free = true;
1711 if (((TREE_CODE (inner_lhs) == PARM_DECL
1712 || (TREE_CODE (inner_lhs) == SSA_NAME
1713 && SSA_NAME_IS_DEFAULT_DEF (inner_lhs)
1714 && TREE_CODE (SSA_NAME_VAR (inner_lhs)) == PARM_DECL))
1715 && inner_lhs != lhs)
1716 || TREE_CODE (inner_lhs) == RESULT_DECL
1717 || (TREE_CODE (inner_lhs) == SSA_NAME
1718 && TREE_CODE (SSA_NAME_VAR (inner_lhs)) == RESULT_DECL))
1719 lhs_free = true;
1720 if (lhs_free && (is_gimple_reg (rhs) || is_gimple_min_invariant (rhs)))
1721 rhs_free = true;
1722 if (lhs_free && rhs_free)
1723 return true;
1725 return false;
1726 default:
1727 return false;
1731 /* Compute function body size parameters for NODE. */
1733 static void
1734 estimate_function_body_sizes (struct cgraph_node *node)
1736 gcov_type time = 0;
1737 gcov_type time_inlining_benefit = 0;
1738 int size = 0;
1739 int size_inlining_benefit = 0;
1740 basic_block bb;
1741 gimple_stmt_iterator bsi;
1742 struct function *my_function = DECL_STRUCT_FUNCTION (node->decl);
1743 tree arg;
1744 int freq;
1745 tree funtype = TREE_TYPE (node->decl);
1747 if (dump_file)
1748 fprintf (dump_file, "Analyzing function body size: %s\n",
1749 cgraph_node_name (node));
1751 gcc_assert (my_function && my_function->cfg);
1752 FOR_EACH_BB_FN (bb, my_function)
1754 freq = compute_call_stmt_bb_frequency (node->decl, bb);
1755 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1757 gimple stmt = gsi_stmt (bsi);
1758 int this_size = estimate_num_insns (stmt, &eni_size_weights);
1759 int this_time = estimate_num_insns (stmt, &eni_time_weights);
1761 if (dump_file && (dump_flags & TDF_DETAILS))
1763 fprintf (dump_file, " freq:%6i size:%3i time:%3i ",
1764 freq, this_size, this_time);
1765 print_gimple_stmt (dump_file, stmt, 0, 0);
1767 this_time *= freq;
1768 time += this_time;
1769 size += this_size;
1770 if (likely_eliminated_by_inlining_p (stmt))
1772 size_inlining_benefit += this_size;
1773 time_inlining_benefit += this_time;
1774 if (dump_file && (dump_flags & TDF_DETAILS))
1775 fprintf (dump_file, " Likely eliminated\n");
1777 gcc_assert (time >= 0);
1778 gcc_assert (size >= 0);
1781 time = (time + CGRAPH_FREQ_BASE / 2) / CGRAPH_FREQ_BASE;
1782 time_inlining_benefit = ((time_inlining_benefit + CGRAPH_FREQ_BASE / 2)
1783 / CGRAPH_FREQ_BASE);
1784 if (dump_file)
1785 fprintf (dump_file, "Overall function body time: %i-%i size: %i-%i\n",
1786 (int)time, (int)time_inlining_benefit,
1787 size, size_inlining_benefit);
1788 time_inlining_benefit += eni_time_weights.call_cost;
1789 size_inlining_benefit += eni_size_weights.call_cost;
1790 if (!VOID_TYPE_P (TREE_TYPE (funtype)))
1792 int cost = estimate_move_cost (TREE_TYPE (funtype));
1793 time_inlining_benefit += cost;
1794 size_inlining_benefit += cost;
1796 for (arg = DECL_ARGUMENTS (node->decl); arg; arg = TREE_CHAIN (arg))
1797 if (!VOID_TYPE_P (TREE_TYPE (arg)))
1799 int cost = estimate_move_cost (TREE_TYPE (arg));
1800 time_inlining_benefit += cost;
1801 size_inlining_benefit += cost;
1803 if (time_inlining_benefit > MAX_TIME)
1804 time_inlining_benefit = MAX_TIME;
1805 if (time > MAX_TIME)
1806 time = MAX_TIME;
1807 inline_summary (node)->self_time = time;
1808 inline_summary (node)->self_size = size;
1809 if (dump_file)
1810 fprintf (dump_file, "With function call overhead time: %i-%i size: %i-%i\n",
1811 (int)time, (int)time_inlining_benefit,
1812 size, size_inlining_benefit);
1813 inline_summary (node)->time_inlining_benefit = time_inlining_benefit;
1814 inline_summary (node)->size_inlining_benefit = size_inlining_benefit;
1817 /* Compute parameters of functions used by inliner. */
1818 unsigned int
1819 compute_inline_parameters (struct cgraph_node *node)
1821 HOST_WIDE_INT self_stack_size;
1823 gcc_assert (!node->global.inlined_to);
1825 /* Estimate the stack size for the function. But not at -O0
1826 because estimated_stack_frame_size is a quadratic problem. */
1827 self_stack_size = optimize ? estimated_stack_frame_size () : 0;
1828 inline_summary (node)->estimated_self_stack_size = self_stack_size;
1829 node->global.estimated_stack_size = self_stack_size;
1830 node->global.stack_frame_offset = 0;
1832 /* Can this function be inlined at all? */
1833 node->local.inlinable = tree_inlinable_function_p (current_function_decl);
1834 if (node->local.inlinable && !node->local.disregard_inline_limits)
1835 node->local.disregard_inline_limits
1836 = DECL_DISREGARD_INLINE_LIMITS (current_function_decl);
1837 estimate_function_body_sizes (node);
1838 /* Inlining characteristics are maintained by the cgraph_mark_inline. */
1839 node->global.time = inline_summary (node)->self_time;
1840 node->global.size = inline_summary (node)->self_size;
1841 return 0;
1845 /* Compute parameters of functions used by inliner using
1846 current_function_decl. */
1847 static unsigned int
1848 compute_inline_parameters_for_current (void)
1850 compute_inline_parameters (cgraph_node (current_function_decl));
1851 return 0;
1854 struct gimple_opt_pass pass_inline_parameters =
1857 GIMPLE_PASS,
1858 "inline_param", /* name */
1859 NULL, /* gate */
1860 compute_inline_parameters_for_current,/* execute */
1861 NULL, /* sub */
1862 NULL, /* next */
1863 0, /* static_pass_number */
1864 TV_INLINE_HEURISTICS, /* tv_id */
1865 0, /* properties_required */
1866 0, /* properties_provided */
1867 0, /* properties_destroyed */
1868 0, /* todo_flags_start */
1869 0 /* todo_flags_finish */
1873 /* This function performs intraprocedural analyzis in NODE that is required to
1874 inline indirect calls. */
1875 static void
1876 inline_indirect_intraprocedural_analysis (struct cgraph_node *node)
1878 struct cgraph_edge *cs;
1880 if (!flag_ipa_cp)
1882 ipa_initialize_node_params (node);
1883 ipa_detect_param_modifications (node);
1885 ipa_analyze_params_uses (node);
1887 if (!flag_ipa_cp)
1888 for (cs = node->callees; cs; cs = cs->next_callee)
1890 ipa_count_arguments (cs);
1891 ipa_compute_jump_functions (cs);
1894 if (dump_file)
1896 ipa_print_node_params (dump_file, node);
1897 ipa_print_node_jump_functions (dump_file, node);
1901 /* Note function body size. */
1902 static void
1903 analyze_function (struct cgraph_node *node)
1905 push_cfun (DECL_STRUCT_FUNCTION (node->decl));
1906 current_function_decl = node->decl;
1908 compute_inline_parameters (node);
1909 if (flag_indirect_inlining)
1910 inline_indirect_intraprocedural_analysis (node);
1912 current_function_decl = NULL;
1913 pop_cfun ();
1916 /* Called when new function is inserted to callgraph late. */
1917 static void
1918 add_new_function (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
1920 analyze_function (node);
1923 /* Note function body size. */
1924 static void
1925 inline_generate_summary (void)
1927 struct cgraph_node *node;
1929 function_insertion_hook_holder =
1930 cgraph_add_function_insertion_hook (&add_new_function, NULL);
1932 if (flag_indirect_inlining)
1934 ipa_register_cgraph_hooks ();
1935 ipa_check_create_node_params ();
1936 ipa_check_create_edge_args ();
1939 for (node = cgraph_nodes; node; node = node->next)
1940 if (node->analyzed)
1941 analyze_function (node);
1943 return;
1946 /* Apply inline plan to function. */
1947 static unsigned int
1948 inline_transform (struct cgraph_node *node)
1950 unsigned int todo = 0;
1951 struct cgraph_edge *e;
1953 /* We might need the body of this function so that we can expand
1954 it inline somewhere else. */
1955 if (cgraph_preserve_function_body_p (node->decl))
1956 save_inline_function_body (node);
1958 for (e = node->callees; e; e = e->next_callee)
1959 if (!e->inline_failed || warn_inline)
1960 break;
1962 if (e)
1964 timevar_push (TV_INTEGRATION);
1965 todo = optimize_inline_calls (current_function_decl);
1966 timevar_pop (TV_INTEGRATION);
1968 cfun->always_inline_functions_inlined = true;
1969 cfun->after_inlining = true;
1970 return todo | execute_fixup_cfg ();
1973 /* Read inline summary. Jump functions are shared among ipa-cp
1974 and inliner, so when ipa-cp is active, we don't need to write them
1975 twice. */
1977 static void
1978 inline_read_summary (void)
1980 if (flag_indirect_inlining && !flag_wpa)
1982 ipa_register_cgraph_hooks ();
1983 if (!flag_ipa_cp)
1984 ipa_prop_read_jump_functions ();
1986 function_insertion_hook_holder =
1987 cgraph_add_function_insertion_hook (&add_new_function, NULL);
1990 /* Write inline summary for node in SET.
1991 Jump functions are shared among ipa-cp and inliner, so when ipa-cp is
1992 active, we don't need to write them twice. */
1994 static void
1995 inline_write_summary (cgraph_node_set set)
1997 if (flag_indirect_inlining && !flag_ipa_cp)
1998 ipa_prop_write_jump_functions (set);
2001 struct ipa_opt_pass_d pass_ipa_inline =
2004 IPA_PASS,
2005 "inline", /* name */
2006 NULL, /* gate */
2007 cgraph_decide_inlining, /* execute */
2008 NULL, /* sub */
2009 NULL, /* next */
2010 0, /* static_pass_number */
2011 TV_INLINE_HEURISTICS, /* tv_id */
2012 0, /* properties_required */
2013 0, /* properties_provided */
2014 0, /* properties_destroyed */
2015 TODO_remove_functions, /* todo_flags_finish */
2016 TODO_dump_cgraph | TODO_dump_func
2017 | TODO_remove_functions /* todo_flags_finish */
2019 inline_generate_summary, /* generate_summary */
2020 inline_write_summary, /* write_summary */
2021 inline_read_summary, /* read_summary */
2022 NULL, /* function_read_summary */
2023 0, /* TODOs */
2024 inline_transform, /* function_transform */
2025 NULL, /* variable_transform */
2029 #include "gt-ipa-inline.h"