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1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2013 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 The implementation of inliner is organized as follows:
25 inlining heuristics limits
27 can_inline_edge_p allow to check that particular inlining is allowed
28 by the limits specified by user (allowed function growth, growth and so
29 on).
31 Functions are inlined when it is obvious the result is profitable (such
32 as functions called once or when inlining reduce code size).
33 In addition to that we perform inlining of small functions and recursive
34 inlining.
36 inlining heuristics
38 The inliner itself is split into two passes:
40 pass_early_inlining
42 Simple local inlining pass inlining callees into current function.
43 This pass makes no use of whole unit analysis and thus it can do only
44 very simple decisions based on local properties.
46 The strength of the pass is that it is run in topological order
47 (reverse postorder) on the callgraph. Functions are converted into SSA
48 form just before this pass and optimized subsequently. As a result, the
49 callees of the function seen by the early inliner was already optimized
50 and results of early inlining adds a lot of optimization opportunities
51 for the local optimization.
53 The pass handle the obvious inlining decisions within the compilation
54 unit - inlining auto inline functions, inlining for size and
55 flattening.
57 main strength of the pass is the ability to eliminate abstraction
58 penalty in C++ code (via combination of inlining and early
59 optimization) and thus improve quality of analysis done by real IPA
60 optimizers.
62 Because of lack of whole unit knowledge, the pass can not really make
63 good code size/performance tradeoffs. It however does very simple
64 speculative inlining allowing code size to grow by
65 EARLY_INLINING_INSNS when callee is leaf function. In this case the
66 optimizations performed later are very likely to eliminate the cost.
68 pass_ipa_inline
70 This is the real inliner able to handle inlining with whole program
71 knowledge. It performs following steps:
73 1) inlining of small functions. This is implemented by greedy
74 algorithm ordering all inlinable cgraph edges by their badness and
75 inlining them in this order as long as inline limits allows doing so.
77 This heuristics is not very good on inlining recursive calls. Recursive
78 calls can be inlined with results similar to loop unrolling. To do so,
79 special purpose recursive inliner is executed on function when
80 recursive edge is met as viable candidate.
82 2) Unreachable functions are removed from callgraph. Inlining leads
83 to devirtualization and other modification of callgraph so functions
84 may become unreachable during the process. Also functions declared as
85 extern inline or virtual functions are removed, since after inlining
86 we no longer need the offline bodies.
88 3) Functions called once and not exported from the unit are inlined.
89 This should almost always lead to reduction of code size by eliminating
90 the need for offline copy of the function. */
92 #include "config.h"
93 #include "system.h"
94 #include "coretypes.h"
95 #include "tm.h"
96 #include "tree.h"
97 #include "tree-inline.h"
98 #include "langhooks.h"
99 #include "flags.h"
100 #include "cgraph.h"
101 #include "diagnostic.h"
102 #include "gimple-pretty-print.h"
103 #include "params.h"
104 #include "fibheap.h"
105 #include "intl.h"
106 #include "tree-pass.h"
107 #include "coverage.h"
108 #include "ggc.h"
109 #include "rtl.h"
110 #include "tree-flow.h"
111 #include "ipa-prop.h"
112 #include "except.h"
113 #include "target.h"
114 #include "ipa-inline.h"
115 #include "ipa-utils.h"
116 #include "sreal.h"
118 /* Statistics we collect about inlining algorithm. */
119 static int overall_size;
120 static gcov_type max_count;
121 static sreal max_count_real, max_relbenefit_real, half_int_min_real;
123 /* Return false when inlining edge E would lead to violating
124 limits on function unit growth or stack usage growth.
126 The relative function body growth limit is present generally
127 to avoid problems with non-linear behavior of the compiler.
128 To allow inlining huge functions into tiny wrapper, the limit
129 is always based on the bigger of the two functions considered.
131 For stack growth limits we always base the growth in stack usage
132 of the callers. We want to prevent applications from segfaulting
133 on stack overflow when functions with huge stack frames gets
134 inlined. */
136 static bool
137 caller_growth_limits (struct cgraph_edge *e)
139 struct cgraph_node *to = e->caller;
140 struct cgraph_node *what = cgraph_function_or_thunk_node (e->callee, NULL);
141 int newsize;
142 int limit = 0;
143 HOST_WIDE_INT stack_size_limit = 0, inlined_stack;
144 struct inline_summary *info, *what_info, *outer_info = inline_summary (to);
146 /* Look for function e->caller is inlined to. While doing
147 so work out the largest function body on the way. As
148 described above, we want to base our function growth
149 limits based on that. Not on the self size of the
150 outer function, not on the self size of inline code
151 we immediately inline to. This is the most relaxed
152 interpretation of the rule "do not grow large functions
153 too much in order to prevent compiler from exploding". */
154 while (true)
156 info = inline_summary (to);
157 if (limit < info->self_size)
158 limit = info->self_size;
159 if (stack_size_limit < info->estimated_self_stack_size)
160 stack_size_limit = info->estimated_self_stack_size;
161 if (to->global.inlined_to)
162 to = to->callers->caller;
163 else
164 break;
167 what_info = inline_summary (what);
169 if (limit < what_info->self_size)
170 limit = what_info->self_size;
172 limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100;
174 /* Check the size after inlining against the function limits. But allow
175 the function to shrink if it went over the limits by forced inlining. */
176 newsize = estimate_size_after_inlining (to, e);
177 if (newsize >= info->size
178 && newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS)
179 && newsize > limit)
181 e->inline_failed = CIF_LARGE_FUNCTION_GROWTH_LIMIT;
182 return false;
185 if (!what_info->estimated_stack_size)
186 return true;
188 /* FIXME: Stack size limit often prevents inlining in Fortran programs
189 due to large i/o datastructures used by the Fortran front-end.
190 We ought to ignore this limit when we know that the edge is executed
191 on every invocation of the caller (i.e. its call statement dominates
192 exit block). We do not track this information, yet. */
193 stack_size_limit += ((gcov_type)stack_size_limit
194 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH) / 100);
196 inlined_stack = (outer_info->stack_frame_offset
197 + outer_info->estimated_self_stack_size
198 + what_info->estimated_stack_size);
199 /* Check new stack consumption with stack consumption at the place
200 stack is used. */
201 if (inlined_stack > stack_size_limit
202 /* If function already has large stack usage from sibling
203 inline call, we can inline, too.
204 This bit overoptimistically assume that we are good at stack
205 packing. */
206 && inlined_stack > info->estimated_stack_size
207 && inlined_stack > PARAM_VALUE (PARAM_LARGE_STACK_FRAME))
209 e->inline_failed = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT;
210 return false;
212 return true;
215 /* Dump info about why inlining has failed. */
217 static void
218 report_inline_failed_reason (struct cgraph_edge *e)
220 if (dump_file)
222 fprintf (dump_file, " not inlinable: %s/%i -> %s/%i, %s\n",
223 xstrdup (cgraph_node_name (e->caller)), e->caller->symbol.order,
224 xstrdup (cgraph_node_name (e->callee)), e->callee->symbol.order,
225 cgraph_inline_failed_string (e->inline_failed));
229 /* Decide if we can inline the edge and possibly update
230 inline_failed reason.
231 We check whether inlining is possible at all and whether
232 caller growth limits allow doing so.
234 if REPORT is true, output reason to the dump file.
236 if DISREGARD_LIMITES is true, ignore size limits.*/
238 static bool
239 can_inline_edge_p (struct cgraph_edge *e, bool report,
240 bool disregard_limits = false)
242 bool inlinable = true;
243 enum availability avail;
244 struct cgraph_node *callee
245 = cgraph_function_or_thunk_node (e->callee, &avail);
246 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (e->caller->symbol.decl);
247 tree callee_tree
248 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->symbol.decl) : NULL;
249 struct function *caller_cfun = DECL_STRUCT_FUNCTION (e->caller->symbol.decl);
250 struct function *callee_cfun
251 = callee ? DECL_STRUCT_FUNCTION (callee->symbol.decl) : NULL;
253 if (!caller_cfun && e->caller->clone_of)
254 caller_cfun = DECL_STRUCT_FUNCTION (e->caller->clone_of->symbol.decl);
256 if (!callee_cfun && callee && callee->clone_of)
257 callee_cfun = DECL_STRUCT_FUNCTION (callee->clone_of->symbol.decl);
259 gcc_assert (e->inline_failed);
261 if (!callee || !callee->symbol.definition)
263 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
264 inlinable = false;
266 else if (!inline_summary (callee)->inlinable)
268 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
269 inlinable = false;
271 else if (avail <= AVAIL_OVERWRITABLE)
273 e->inline_failed = CIF_OVERWRITABLE;
274 inlinable = false;
276 else if (e->call_stmt_cannot_inline_p)
278 e->inline_failed = CIF_MISMATCHED_ARGUMENTS;
279 inlinable = false;
281 /* Don't inline if the functions have different EH personalities. */
282 else if (DECL_FUNCTION_PERSONALITY (e->caller->symbol.decl)
283 && DECL_FUNCTION_PERSONALITY (callee->symbol.decl)
284 && (DECL_FUNCTION_PERSONALITY (e->caller->symbol.decl)
285 != DECL_FUNCTION_PERSONALITY (callee->symbol.decl)))
287 e->inline_failed = CIF_EH_PERSONALITY;
288 inlinable = false;
290 /* TM pure functions should not be inlined into non-TM_pure
291 functions. */
292 else if (is_tm_pure (callee->symbol.decl)
293 && !is_tm_pure (e->caller->symbol.decl))
295 e->inline_failed = CIF_UNSPECIFIED;
296 inlinable = false;
298 /* Don't inline if the callee can throw non-call exceptions but the
299 caller cannot.
300 FIXME: this is obviously wrong for LTO where STRUCT_FUNCTION is missing.
301 Move the flag into cgraph node or mirror it in the inline summary. */
302 else if (callee_cfun && callee_cfun->can_throw_non_call_exceptions
303 && !(caller_cfun && caller_cfun->can_throw_non_call_exceptions))
305 e->inline_failed = CIF_NON_CALL_EXCEPTIONS;
306 inlinable = false;
308 /* Check compatibility of target optimization options. */
309 else if (!targetm.target_option.can_inline_p (e->caller->symbol.decl,
310 callee->symbol.decl))
312 e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
313 inlinable = false;
315 /* Check if caller growth allows the inlining. */
316 else if (!DECL_DISREGARD_INLINE_LIMITS (callee->symbol.decl)
317 && !disregard_limits
318 && !lookup_attribute ("flatten",
319 DECL_ATTRIBUTES
320 (e->caller->global.inlined_to
321 ? e->caller->global.inlined_to->symbol.decl
322 : e->caller->symbol.decl))
323 && !caller_growth_limits (e))
324 inlinable = false;
325 /* Don't inline a function with a higher optimization level than the
326 caller. FIXME: this is really just tip of iceberg of handling
327 optimization attribute. */
328 else if (caller_tree != callee_tree)
330 struct cl_optimization *caller_opt
331 = TREE_OPTIMIZATION ((caller_tree)
332 ? caller_tree
333 : optimization_default_node);
335 struct cl_optimization *callee_opt
336 = TREE_OPTIMIZATION ((callee_tree)
337 ? callee_tree
338 : optimization_default_node);
340 if (((caller_opt->x_optimize > callee_opt->x_optimize)
341 || (caller_opt->x_optimize_size != callee_opt->x_optimize_size))
342 /* gcc.dg/pr43564.c. Look at forced inline even in -O0. */
343 && !DECL_DISREGARD_INLINE_LIMITS (e->callee->symbol.decl))
345 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
346 inlinable = false;
350 if (!inlinable && report)
351 report_inline_failed_reason (e);
352 return inlinable;
356 /* Return true if the edge E is inlinable during early inlining. */
358 static bool
359 can_early_inline_edge_p (struct cgraph_edge *e)
361 struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee,
362 NULL);
363 /* Early inliner might get called at WPA stage when IPA pass adds new
364 function. In this case we can not really do any of early inlining
365 because function bodies are missing. */
366 if (!gimple_has_body_p (callee->symbol.decl))
368 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
369 return false;
371 /* In early inliner some of callees may not be in SSA form yet
372 (i.e. the callgraph is cyclic and we did not process
373 the callee by early inliner, yet). We don't have CIF code for this
374 case; later we will re-do the decision in the real inliner. */
375 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->symbol.decl))
376 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->symbol.decl)))
378 if (dump_file)
379 fprintf (dump_file, " edge not inlinable: not in SSA form\n");
380 return false;
382 if (!can_inline_edge_p (e, true))
383 return false;
384 return true;
388 /* Return number of calls in N. Ignore cheap builtins. */
390 static int
391 num_calls (struct cgraph_node *n)
393 struct cgraph_edge *e;
394 int num = 0;
396 for (e = n->callees; e; e = e->next_callee)
397 if (!is_inexpensive_builtin (e->callee->symbol.decl))
398 num++;
399 return num;
403 /* Return true if we are interested in inlining small function. */
405 static bool
406 want_early_inline_function_p (struct cgraph_edge *e)
408 bool want_inline = true;
409 struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL);
411 if (DECL_DISREGARD_INLINE_LIMITS (callee->symbol.decl))
413 else if (!DECL_DECLARED_INLINE_P (callee->symbol.decl)
414 && !flag_inline_small_functions)
416 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
417 report_inline_failed_reason (e);
418 want_inline = false;
420 else
422 int growth = estimate_edge_growth (e);
423 int n;
425 if (growth <= 0)
427 else if (!cgraph_maybe_hot_edge_p (e)
428 && growth > 0)
430 if (dump_file)
431 fprintf (dump_file, " will not early inline: %s/%i->%s/%i, "
432 "call is cold and code would grow by %i\n",
433 xstrdup (cgraph_node_name (e->caller)),
434 e->caller->symbol.order,
435 xstrdup (cgraph_node_name (callee)), callee->symbol.order,
436 growth);
437 want_inline = false;
439 else if (growth > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS))
441 if (dump_file)
442 fprintf (dump_file, " will not early inline: %s/%i->%s/%i, "
443 "growth %i exceeds --param early-inlining-insns\n",
444 xstrdup (cgraph_node_name (e->caller)),
445 e->caller->symbol.order,
446 xstrdup (cgraph_node_name (callee)), callee->symbol.order,
447 growth);
448 want_inline = false;
450 else if ((n = num_calls (callee)) != 0
451 && growth * (n + 1) > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS))
453 if (dump_file)
454 fprintf (dump_file, " will not early inline: %s/%i->%s/%i, "
455 "growth %i exceeds --param early-inlining-insns "
456 "divided by number of calls\n",
457 xstrdup (cgraph_node_name (e->caller)),
458 e->caller->symbol.order,
459 xstrdup (cgraph_node_name (callee)), callee->symbol.order,
460 growth);
461 want_inline = false;
464 return want_inline;
467 /* Compute time of the edge->caller + edge->callee execution when inlining
468 does not happen. */
470 inline gcov_type
471 compute_uninlined_call_time (struct inline_summary *callee_info,
472 struct cgraph_edge *edge)
474 gcov_type uninlined_call_time =
475 RDIV ((gcov_type)callee_info->time * MAX (edge->frequency, 1),
476 CGRAPH_FREQ_BASE);
477 gcov_type caller_time = inline_summary (edge->caller->global.inlined_to
478 ? edge->caller->global.inlined_to
479 : edge->caller)->time;
480 return uninlined_call_time + caller_time;
483 /* Same as compute_uinlined_call_time but compute time when inlining
484 does happen. */
486 inline gcov_type
487 compute_inlined_call_time (struct cgraph_edge *edge,
488 int edge_time)
490 gcov_type caller_time = inline_summary (edge->caller->global.inlined_to
491 ? edge->caller->global.inlined_to
492 : edge->caller)->time;
493 gcov_type time = (caller_time
494 + RDIV (((gcov_type) edge_time
495 - inline_edge_summary (edge)->call_stmt_time)
496 * MAX (edge->frequency, 1), CGRAPH_FREQ_BASE));
497 /* Possible one roundoff error, but watch for overflows. */
498 gcc_checking_assert (time >= INT_MIN / 2);
499 if (time < 0)
500 time = 0;
501 return time;
504 /* Return true if the speedup for inlining E is bigger than
505 PARAM_MAX_INLINE_MIN_SPEEDUP. */
507 static bool
508 big_speedup_p (struct cgraph_edge *e)
510 gcov_type time = compute_uninlined_call_time (inline_summary (e->callee),
512 gcov_type inlined_time = compute_inlined_call_time (e,
513 estimate_edge_time (e));
514 if (time - inlined_time
515 > RDIV (time * PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP), 100))
516 return true;
517 return false;
520 /* Return true if we are interested in inlining small function.
521 When REPORT is true, report reason to dump file. */
523 static bool
524 want_inline_small_function_p (struct cgraph_edge *e, bool report)
526 bool want_inline = true;
527 struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL);
529 if (DECL_DISREGARD_INLINE_LIMITS (callee->symbol.decl))
531 else if (!DECL_DECLARED_INLINE_P (callee->symbol.decl)
532 && !flag_inline_small_functions)
534 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
535 want_inline = false;
537 else
539 int growth = estimate_edge_growth (e);
540 inline_hints hints = estimate_edge_hints (e);
541 bool big_speedup = big_speedup_p (e);
543 if (growth <= 0)
545 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when
546 hints suggests that inlining given function is very profitable. */
547 else if (DECL_DECLARED_INLINE_P (callee->symbol.decl)
548 && growth >= MAX_INLINE_INSNS_SINGLE
549 && !big_speedup
550 && !(hints & (INLINE_HINT_indirect_call
551 | INLINE_HINT_loop_iterations
552 | INLINE_HINT_array_index
553 | INLINE_HINT_loop_stride)))
555 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
556 want_inline = false;
558 /* Before giving up based on fact that caller size will grow, allow
559 functions that are called few times and eliminating the offline
560 copy will lead to overall code size reduction.
561 Not all of these will be handled by subsequent inlining of functions
562 called once: in particular weak functions are not handled or funcitons
563 that inline to multiple calls but a lot of bodies is optimized out.
564 Finally we want to inline earlier to allow inlining of callbacks.
566 This is slightly wrong on aggressive side: it is entirely possible
567 that function is called many times with a context where inlining
568 reduces code size and few times with a context where inlining increase
569 code size. Resoluting growth estimate will be negative even if it
570 would make more sense to keep offline copy and do not inline into the
571 call sites that makes the code size grow.
573 When badness orders the calls in a way that code reducing calls come
574 first, this situation is not a problem at all: after inlining all
575 "good" calls, we will realize that keeping the function around is
576 better. */
577 else if (growth <= MAX_INLINE_INSNS_SINGLE
578 /* Unlike for functions called once, we play unsafe with
579 COMDATs. We can allow that since we know functions
580 in consideration are small (and thus risk is small) and
581 moreover grow estimates already accounts that COMDAT
582 functions may or may not disappear when eliminated from
583 current unit. With good probability making aggressive
584 choice in all units is going to make overall program
585 smaller.
587 Consequently we ask cgraph_can_remove_if_no_direct_calls_p
588 instead of
589 cgraph_will_be_removed_from_program_if_no_direct_calls */
590 && !DECL_EXTERNAL (callee->symbol.decl)
591 && cgraph_can_remove_if_no_direct_calls_p (callee)
592 && estimate_growth (callee) <= 0)
594 else if (!DECL_DECLARED_INLINE_P (callee->symbol.decl)
595 && !flag_inline_functions)
597 e->inline_failed = CIF_NOT_DECLARED_INLINED;
598 want_inline = false;
600 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline
601 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that
602 inlining given function is very profitable. */
603 else if (!DECL_DECLARED_INLINE_P (callee->symbol.decl)
604 && !big_speedup
605 && growth >= ((hints & (INLINE_HINT_indirect_call
606 | INLINE_HINT_loop_iterations
607 | INLINE_HINT_array_index
608 | INLINE_HINT_loop_stride))
609 ? MAX (MAX_INLINE_INSNS_AUTO,
610 MAX_INLINE_INSNS_SINGLE)
611 : MAX_INLINE_INSNS_AUTO))
613 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
614 want_inline = false;
616 /* If call is cold, do not inline when function body would grow. */
617 else if (!cgraph_maybe_hot_edge_p (e))
619 e->inline_failed = CIF_UNLIKELY_CALL;
620 want_inline = false;
623 if (!want_inline && report)
624 report_inline_failed_reason (e);
625 return want_inline;
628 /* EDGE is self recursive edge.
629 We hand two cases - when function A is inlining into itself
630 or when function A is being inlined into another inliner copy of function
631 A within function B.
633 In first case OUTER_NODE points to the toplevel copy of A, while
634 in the second case OUTER_NODE points to the outermost copy of A in B.
636 In both cases we want to be extra selective since
637 inlining the call will just introduce new recursive calls to appear. */
639 static bool
640 want_inline_self_recursive_call_p (struct cgraph_edge *edge,
641 struct cgraph_node *outer_node,
642 bool peeling,
643 int depth)
645 char const *reason = NULL;
646 bool want_inline = true;
647 int caller_freq = CGRAPH_FREQ_BASE;
648 int max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO);
650 if (DECL_DECLARED_INLINE_P (edge->caller->symbol.decl))
651 max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH);
653 if (!cgraph_maybe_hot_edge_p (edge))
655 reason = "recursive call is cold";
656 want_inline = false;
658 else if (max_count && !outer_node->count)
660 reason = "not executed in profile";
661 want_inline = false;
663 else if (depth > max_depth)
665 reason = "--param max-inline-recursive-depth exceeded.";
666 want_inline = false;
669 if (outer_node->global.inlined_to)
670 caller_freq = outer_node->callers->frequency;
672 if (!want_inline)
674 /* Inlining of self recursive function into copy of itself within other function
675 is transformation similar to loop peeling.
677 Peeling is profitable if we can inline enough copies to make probability
678 of actual call to the self recursive function very small. Be sure that
679 the probability of recursion is small.
681 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
682 This way the expected number of recision is at most max_depth. */
683 else if (peeling)
685 int max_prob = CGRAPH_FREQ_BASE - ((CGRAPH_FREQ_BASE + max_depth - 1)
686 / max_depth);
687 int i;
688 for (i = 1; i < depth; i++)
689 max_prob = max_prob * max_prob / CGRAPH_FREQ_BASE;
690 if (max_count
691 && (edge->count * CGRAPH_FREQ_BASE / outer_node->count
692 >= max_prob))
694 reason = "profile of recursive call is too large";
695 want_inline = false;
697 if (!max_count
698 && (edge->frequency * CGRAPH_FREQ_BASE / caller_freq
699 >= max_prob))
701 reason = "frequency of recursive call is too large";
702 want_inline = false;
705 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if recursion
706 depth is large. We reduce function call overhead and increase chances that
707 things fit in hardware return predictor.
709 Recursive inlining might however increase cost of stack frame setup
710 actually slowing down functions whose recursion tree is wide rather than
711 deep.
713 Deciding reliably on when to do recursive inlining without profile feedback
714 is tricky. For now we disable recursive inlining when probability of self
715 recursion is low.
717 Recursive inlining of self recursive call within loop also results in large loop
718 depths that generally optimize badly. We may want to throttle down inlining
719 in those cases. In particular this seems to happen in one of libstdc++ rb tree
720 methods. */
721 else
723 if (max_count
724 && (edge->count * 100 / outer_node->count
725 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY)))
727 reason = "profile of recursive call is too small";
728 want_inline = false;
730 else if (!max_count
731 && (edge->frequency * 100 / caller_freq
732 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY)))
734 reason = "frequency of recursive call is too small";
735 want_inline = false;
738 if (!want_inline && dump_file)
739 fprintf (dump_file, " not inlining recursively: %s\n", reason);
740 return want_inline;
743 /* Return true when NODE has caller other than EDGE.
744 Worker for cgraph_for_node_and_aliases. */
746 static bool
747 check_caller_edge (struct cgraph_node *node, void *edge)
749 return (node->callers
750 && node->callers != edge);
754 /* Decide if inlining NODE would reduce unit size by eliminating
755 the offline copy of function.
756 When COLD is true the cold calls are considered, too. */
758 static bool
759 want_inline_function_to_all_callers_p (struct cgraph_node *node, bool cold)
761 struct cgraph_node *function = cgraph_function_or_thunk_node (node, NULL);
762 struct cgraph_edge *e;
763 bool has_hot_call = false;
765 /* Does it have callers? */
766 if (!node->callers)
767 return false;
768 /* Already inlined? */
769 if (function->global.inlined_to)
770 return false;
771 if (cgraph_function_or_thunk_node (node, NULL) != node)
772 return false;
773 /* Inlining into all callers would increase size? */
774 if (estimate_growth (node) > 0)
775 return false;
776 /* Maybe other aliases has more direct calls. */
777 if (cgraph_for_node_and_aliases (node, check_caller_edge, node->callers, true))
778 return false;
779 /* All inlines must be possible. */
780 for (e = node->callers; e; e = e->next_caller)
782 if (!can_inline_edge_p (e, true))
783 return false;
784 if (!has_hot_call && cgraph_maybe_hot_edge_p (e))
785 has_hot_call = 1;
788 if (!cold && !has_hot_call)
789 return false;
790 return true;
793 #define RELATIVE_TIME_BENEFIT_RANGE (INT_MAX / 64)
795 /* Return relative time improvement for inlining EDGE in range
796 1...RELATIVE_TIME_BENEFIT_RANGE */
798 static inline int
799 relative_time_benefit (struct inline_summary *callee_info,
800 struct cgraph_edge *edge,
801 int edge_time)
803 gcov_type relbenefit;
804 gcov_type uninlined_call_time = compute_uninlined_call_time (callee_info, edge);
805 gcov_type inlined_call_time = compute_inlined_call_time (edge, edge_time);
807 /* Inlining into extern inline function is not a win. */
808 if (DECL_EXTERNAL (edge->caller->global.inlined_to
809 ? edge->caller->global.inlined_to->symbol.decl
810 : edge->caller->symbol.decl))
811 return 1;
813 /* Watch overflows. */
814 gcc_checking_assert (uninlined_call_time >= 0);
815 gcc_checking_assert (inlined_call_time >= 0);
816 gcc_checking_assert (uninlined_call_time >= inlined_call_time);
818 /* Compute relative time benefit, i.e. how much the call becomes faster.
819 ??? perhaps computing how much the caller+calle together become faster
820 would lead to more realistic results. */
821 if (!uninlined_call_time)
822 uninlined_call_time = 1;
823 relbenefit =
824 RDIV (((gcov_type)uninlined_call_time - inlined_call_time) * RELATIVE_TIME_BENEFIT_RANGE,
825 uninlined_call_time);
826 relbenefit = MIN (relbenefit, RELATIVE_TIME_BENEFIT_RANGE);
827 gcc_checking_assert (relbenefit >= 0);
828 relbenefit = MAX (relbenefit, 1);
829 return relbenefit;
833 /* A cost model driving the inlining heuristics in a way so the edges with
834 smallest badness are inlined first. After each inlining is performed
835 the costs of all caller edges of nodes affected are recomputed so the
836 metrics may accurately depend on values such as number of inlinable callers
837 of the function or function body size. */
839 static int
840 edge_badness (struct cgraph_edge *edge, bool dump)
842 gcov_type badness;
843 int growth, edge_time;
844 struct cgraph_node *callee = cgraph_function_or_thunk_node (edge->callee,
845 NULL);
846 struct inline_summary *callee_info = inline_summary (callee);
847 inline_hints hints;
849 if (DECL_DISREGARD_INLINE_LIMITS (callee->symbol.decl))
850 return INT_MIN;
852 growth = estimate_edge_growth (edge);
853 edge_time = estimate_edge_time (edge);
854 hints = estimate_edge_hints (edge);
855 gcc_checking_assert (edge_time >= 0);
856 gcc_checking_assert (edge_time <= callee_info->time);
857 gcc_checking_assert (growth <= callee_info->size);
859 if (dump)
861 fprintf (dump_file, " Badness calculation for %s/%i -> %s/%i\n",
862 xstrdup (cgraph_node_name (edge->caller)),
863 edge->caller->symbol.order,
864 xstrdup (cgraph_node_name (callee)),
865 edge->callee->symbol.order);
866 fprintf (dump_file, " size growth %i, time %i ",
867 growth,
868 edge_time);
869 dump_inline_hints (dump_file, hints);
870 if (big_speedup_p (edge))
871 fprintf (dump_file, " big_speedup");
872 fprintf (dump_file, "\n");
875 /* Always prefer inlining saving code size. */
876 if (growth <= 0)
878 badness = INT_MIN / 2 + growth;
879 if (dump)
880 fprintf (dump_file, " %i: Growth %i <= 0\n", (int) badness,
881 growth);
884 /* When profiling is available, compute badness as:
886 relative_edge_count * relative_time_benefit
887 goodness = -------------------------------------------
888 growth_f_caller
889 badness = -goodness
891 The fraction is upside down, because on edge counts and time beneits
892 the bounds are known. Edge growth is essentially unlimited. */
894 else if (max_count)
896 sreal tmp, relbenefit_real, growth_real;
897 int relbenefit = relative_time_benefit (callee_info, edge, edge_time);
899 sreal_init(&relbenefit_real, relbenefit, 0);
900 sreal_init(&growth_real, growth, 0);
902 /* relative_edge_count. */
903 sreal_init (&tmp, edge->count, 0);
904 sreal_div (&tmp, &tmp, &max_count_real);
906 /* relative_time_benefit. */
907 sreal_mul (&tmp, &tmp, &relbenefit_real);
908 sreal_div (&tmp, &tmp, &max_relbenefit_real);
910 /* growth_f_caller. */
911 sreal_mul (&tmp, &tmp, &half_int_min_real);
912 sreal_div (&tmp, &tmp, &growth_real);
914 badness = -1 * sreal_to_int (&tmp);
916 /* Be sure that insanity of the profile won't lead to increasing counts
917 in the scalling and thus to overflow in the computation above. */
918 gcc_assert (max_count >= edge->count);
919 if (dump)
921 fprintf (dump_file,
922 " %i (relative %f): profile info. Relative count %f"
923 " * Relative benefit %f\n",
924 (int) badness, (double) badness / INT_MIN,
925 (double) edge->count / max_count,
926 relbenefit * 100.0 / RELATIVE_TIME_BENEFIT_RANGE);
930 /* When function local profile is available. Compute badness as:
932 relative_time_benefit
933 goodness = ---------------------------------
934 growth_of_caller * overall_growth
936 badness = - goodness
938 compensated by the inline hints.
940 else if (flag_guess_branch_prob)
942 badness = (relative_time_benefit (callee_info, edge, edge_time)
943 * (INT_MIN / 16 / RELATIVE_TIME_BENEFIT_RANGE));
944 badness /= (MIN (65536/2, growth) * MIN (65536/2, MAX (1, callee_info->growth)));
945 gcc_checking_assert (badness <=0 && badness >= INT_MIN / 16);
946 if ((hints & (INLINE_HINT_indirect_call
947 | INLINE_HINT_loop_iterations
948 | INLINE_HINT_array_index
949 | INLINE_HINT_loop_stride))
950 || callee_info->growth <= 0)
951 badness *= 8;
952 if (hints & (INLINE_HINT_same_scc))
953 badness /= 16;
954 else if (hints & (INLINE_HINT_in_scc))
955 badness /= 8;
956 else if (hints & (INLINE_HINT_cross_module))
957 badness /= 2;
958 gcc_checking_assert (badness <= 0 && badness >= INT_MIN / 2);
959 if ((hints & INLINE_HINT_declared_inline) && badness >= INT_MIN / 32)
960 badness *= 16;
961 if (dump)
963 fprintf (dump_file,
964 " %i: guessed profile. frequency %f,"
965 " benefit %f%%, time w/o inlining %i, time w inlining %i"
966 " overall growth %i (current) %i (original)\n",
967 (int) badness, (double)edge->frequency / CGRAPH_FREQ_BASE,
968 relative_time_benefit (callee_info, edge, edge_time) * 100.0
969 / RELATIVE_TIME_BENEFIT_RANGE,
970 (int)compute_uninlined_call_time (callee_info, edge),
971 (int)compute_inlined_call_time (edge, edge_time),
972 estimate_growth (callee),
973 callee_info->growth);
976 /* When function local profile is not available or it does not give
977 useful information (ie frequency is zero), base the cost on
978 loop nest and overall size growth, so we optimize for overall number
979 of functions fully inlined in program. */
980 else
982 int nest = MIN (inline_edge_summary (edge)->loop_depth, 8);
983 badness = growth * 256;
985 /* Decrease badness if call is nested. */
986 if (badness > 0)
987 badness >>= nest;
988 else
990 badness <<= nest;
992 if (dump)
993 fprintf (dump_file, " %i: no profile. nest %i\n", (int) badness,
994 nest);
997 /* Ensure that we did not overflow in all the fixed point math above. */
998 gcc_assert (badness >= INT_MIN);
999 gcc_assert (badness <= INT_MAX - 1);
1000 /* Make recursive inlining happen always after other inlining is done. */
1001 if (cgraph_edge_recursive_p (edge))
1002 return badness + 1;
1003 else
1004 return badness;
1007 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1008 static inline void
1009 update_edge_key (fibheap_t heap, struct cgraph_edge *edge)
1011 int badness = edge_badness (edge, false);
1012 if (edge->aux)
1014 fibnode_t n = (fibnode_t) edge->aux;
1015 gcc_checking_assert (n->data == edge);
1017 /* fibheap_replace_key only decrease the keys.
1018 When we increase the key we do not update heap
1019 and instead re-insert the element once it becomes
1020 a minimum of heap. */
1021 if (badness < n->key)
1023 if (dump_file && (dump_flags & TDF_DETAILS))
1025 fprintf (dump_file,
1026 " decreasing badness %s/%i -> %s/%i, %i to %i\n",
1027 xstrdup (cgraph_node_name (edge->caller)),
1028 edge->caller->symbol.order,
1029 xstrdup (cgraph_node_name (edge->callee)),
1030 edge->callee->symbol.order,
1031 (int)n->key,
1032 badness);
1034 fibheap_replace_key (heap, n, badness);
1035 gcc_checking_assert (n->key == badness);
1038 else
1040 if (dump_file && (dump_flags & TDF_DETAILS))
1042 fprintf (dump_file,
1043 " enqueuing call %s/%i -> %s/%i, badness %i\n",
1044 xstrdup (cgraph_node_name (edge->caller)),
1045 edge->caller->symbol.order,
1046 xstrdup (cgraph_node_name (edge->callee)),
1047 edge->callee->symbol.order,
1048 badness);
1050 edge->aux = fibheap_insert (heap, badness, edge);
1055 /* NODE was inlined.
1056 All caller edges needs to be resetted because
1057 size estimates change. Similarly callees needs reset
1058 because better context may be known. */
1060 static void
1061 reset_edge_caches (struct cgraph_node *node)
1063 struct cgraph_edge *edge;
1064 struct cgraph_edge *e = node->callees;
1065 struct cgraph_node *where = node;
1066 int i;
1067 struct ipa_ref *ref;
1069 if (where->global.inlined_to)
1070 where = where->global.inlined_to;
1072 /* WHERE body size has changed, the cached growth is invalid. */
1073 reset_node_growth_cache (where);
1075 for (edge = where->callers; edge; edge = edge->next_caller)
1076 if (edge->inline_failed)
1077 reset_edge_growth_cache (edge);
1078 for (i = 0; ipa_ref_list_referring_iterate (&where->symbol.ref_list,
1079 i, ref); i++)
1080 if (ref->use == IPA_REF_ALIAS)
1081 reset_edge_caches (ipa_ref_referring_node (ref));
1083 if (!e)
1084 return;
1086 while (true)
1087 if (!e->inline_failed && e->callee->callees)
1088 e = e->callee->callees;
1089 else
1091 if (e->inline_failed)
1092 reset_edge_growth_cache (e);
1093 if (e->next_callee)
1094 e = e->next_callee;
1095 else
1099 if (e->caller == node)
1100 return;
1101 e = e->caller->callers;
1103 while (!e->next_callee);
1104 e = e->next_callee;
1109 /* Recompute HEAP nodes for each of caller of NODE.
1110 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1111 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1112 it is inlinable. Otherwise check all edges. */
1114 static void
1115 update_caller_keys (fibheap_t heap, struct cgraph_node *node,
1116 bitmap updated_nodes,
1117 struct cgraph_edge *check_inlinablity_for)
1119 struct cgraph_edge *edge;
1120 int i;
1121 struct ipa_ref *ref;
1123 if ((!node->symbol.alias && !inline_summary (node)->inlinable)
1124 || node->global.inlined_to)
1125 return;
1126 if (!bitmap_set_bit (updated_nodes, node->uid))
1127 return;
1129 for (i = 0; ipa_ref_list_referring_iterate (&node->symbol.ref_list,
1130 i, ref); i++)
1131 if (ref->use == IPA_REF_ALIAS)
1133 struct cgraph_node *alias = ipa_ref_referring_node (ref);
1134 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for);
1137 for (edge = node->callers; edge; edge = edge->next_caller)
1138 if (edge->inline_failed)
1140 if (!check_inlinablity_for
1141 || check_inlinablity_for == edge)
1143 if (can_inline_edge_p (edge, false)
1144 && want_inline_small_function_p (edge, false))
1145 update_edge_key (heap, edge);
1146 else if (edge->aux)
1148 report_inline_failed_reason (edge);
1149 fibheap_delete_node (heap, (fibnode_t) edge->aux);
1150 edge->aux = NULL;
1153 else if (edge->aux)
1154 update_edge_key (heap, edge);
1158 /* Recompute HEAP nodes for each uninlined call in NODE.
1159 This is used when we know that edge badnesses are going only to increase
1160 (we introduced new call site) and thus all we need is to insert newly
1161 created edges into heap. */
1163 static void
1164 update_callee_keys (fibheap_t heap, struct cgraph_node *node,
1165 bitmap updated_nodes)
1167 struct cgraph_edge *e = node->callees;
1169 if (!e)
1170 return;
1171 while (true)
1172 if (!e->inline_failed && e->callee->callees)
1173 e = e->callee->callees;
1174 else
1176 enum availability avail;
1177 struct cgraph_node *callee;
1178 /* We do not reset callee growth cache here. Since we added a new call,
1179 growth chould have just increased and consequentely badness metric
1180 don't need updating. */
1181 if (e->inline_failed
1182 && (callee = cgraph_function_or_thunk_node (e->callee, &avail))
1183 && inline_summary (callee)->inlinable
1184 && avail >= AVAIL_AVAILABLE
1185 && !bitmap_bit_p (updated_nodes, callee->uid))
1187 if (can_inline_edge_p (e, false)
1188 && want_inline_small_function_p (e, false))
1189 update_edge_key (heap, e);
1190 else if (e->aux)
1192 report_inline_failed_reason (e);
1193 fibheap_delete_node (heap, (fibnode_t) e->aux);
1194 e->aux = NULL;
1197 if (e->next_callee)
1198 e = e->next_callee;
1199 else
1203 if (e->caller == node)
1204 return;
1205 e = e->caller->callers;
1207 while (!e->next_callee);
1208 e = e->next_callee;
1213 /* Enqueue all recursive calls from NODE into priority queue depending on
1214 how likely we want to recursively inline the call. */
1216 static void
1217 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
1218 fibheap_t heap)
1220 struct cgraph_edge *e;
1221 enum availability avail;
1223 for (e = where->callees; e; e = e->next_callee)
1224 if (e->callee == node
1225 || (cgraph_function_or_thunk_node (e->callee, &avail) == node
1226 && avail > AVAIL_OVERWRITABLE))
1228 /* When profile feedback is available, prioritize by expected number
1229 of calls. */
1230 fibheap_insert (heap,
1231 !max_count ? -e->frequency
1232 : -(e->count / ((max_count + (1<<24) - 1) / (1<<24))),
1235 for (e = where->callees; e; e = e->next_callee)
1236 if (!e->inline_failed)
1237 lookup_recursive_calls (node, e->callee, heap);
1240 /* Decide on recursive inlining: in the case function has recursive calls,
1241 inline until body size reaches given argument. If any new indirect edges
1242 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1243 is NULL. */
1245 static bool
1246 recursive_inlining (struct cgraph_edge *edge,
1247 vec<cgraph_edge_p> *new_edges)
1249 int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO);
1250 fibheap_t heap;
1251 struct cgraph_node *node;
1252 struct cgraph_edge *e;
1253 struct cgraph_node *master_clone = NULL, *next;
1254 int depth = 0;
1255 int n = 0;
1257 node = edge->caller;
1258 if (node->global.inlined_to)
1259 node = node->global.inlined_to;
1261 if (DECL_DECLARED_INLINE_P (node->symbol.decl))
1262 limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE);
1264 /* Make sure that function is small enough to be considered for inlining. */
1265 if (estimate_size_after_inlining (node, edge) >= limit)
1266 return false;
1267 heap = fibheap_new ();
1268 lookup_recursive_calls (node, node, heap);
1269 if (fibheap_empty (heap))
1271 fibheap_delete (heap);
1272 return false;
1275 if (dump_file)
1276 fprintf (dump_file,
1277 " Performing recursive inlining on %s\n",
1278 cgraph_node_name (node));
1280 /* Do the inlining and update list of recursive call during process. */
1281 while (!fibheap_empty (heap))
1283 struct cgraph_edge *curr
1284 = (struct cgraph_edge *) fibheap_extract_min (heap);
1285 struct cgraph_node *cnode, *dest = curr->callee;
1287 if (!can_inline_edge_p (curr, true))
1288 continue;
1290 /* MASTER_CLONE is produced in the case we already started modified
1291 the function. Be sure to redirect edge to the original body before
1292 estimating growths otherwise we will be seeing growths after inlining
1293 the already modified body. */
1294 if (master_clone)
1296 cgraph_redirect_edge_callee (curr, master_clone);
1297 reset_edge_growth_cache (curr);
1300 if (estimate_size_after_inlining (node, curr) > limit)
1302 cgraph_redirect_edge_callee (curr, dest);
1303 reset_edge_growth_cache (curr);
1304 break;
1307 depth = 1;
1308 for (cnode = curr->caller;
1309 cnode->global.inlined_to; cnode = cnode->callers->caller)
1310 if (node->symbol.decl
1311 == cgraph_function_or_thunk_node (curr->callee, NULL)->symbol.decl)
1312 depth++;
1314 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1316 cgraph_redirect_edge_callee (curr, dest);
1317 reset_edge_growth_cache (curr);
1318 continue;
1321 if (dump_file)
1323 fprintf (dump_file,
1324 " Inlining call of depth %i", depth);
1325 if (node->count)
1327 fprintf (dump_file, " called approx. %.2f times per call",
1328 (double)curr->count / node->count);
1330 fprintf (dump_file, "\n");
1332 if (!master_clone)
1334 /* We need original clone to copy around. */
1335 master_clone = cgraph_clone_node (node, node->symbol.decl,
1336 node->count, CGRAPH_FREQ_BASE,
1337 false, vNULL, true, NULL);
1338 for (e = master_clone->callees; e; e = e->next_callee)
1339 if (!e->inline_failed)
1340 clone_inlined_nodes (e, true, false, NULL);
1341 cgraph_redirect_edge_callee (curr, master_clone);
1342 reset_edge_growth_cache (curr);
1345 inline_call (curr, false, new_edges, &overall_size, true);
1346 lookup_recursive_calls (node, curr->callee, heap);
1347 n++;
1350 if (!fibheap_empty (heap) && dump_file)
1351 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1352 fibheap_delete (heap);
1354 if (!master_clone)
1355 return false;
1357 if (dump_file)
1358 fprintf (dump_file,
1359 "\n Inlined %i times, "
1360 "body grown from size %i to %i, time %i to %i\n", n,
1361 inline_summary (master_clone)->size, inline_summary (node)->size,
1362 inline_summary (master_clone)->time, inline_summary (node)->time);
1364 /* Remove master clone we used for inlining. We rely that clones inlined
1365 into master clone gets queued just before master clone so we don't
1366 need recursion. */
1367 for (node = cgraph_first_function (); node != master_clone;
1368 node = next)
1370 next = cgraph_next_function (node);
1371 if (node->global.inlined_to == master_clone)
1372 cgraph_remove_node (node);
1374 cgraph_remove_node (master_clone);
1375 return true;
1379 /* Given whole compilation unit estimate of INSNS, compute how large we can
1380 allow the unit to grow. */
1382 static int
1383 compute_max_insns (int insns)
1385 int max_insns = insns;
1386 if (max_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS))
1387 max_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS);
1389 return ((HOST_WIDEST_INT) max_insns
1390 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100);
1394 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1396 static void
1397 add_new_edges_to_heap (fibheap_t heap, vec<cgraph_edge_p> new_edges)
1399 while (new_edges.length () > 0)
1401 struct cgraph_edge *edge = new_edges.pop ();
1403 gcc_assert (!edge->aux);
1404 if (edge->inline_failed
1405 && can_inline_edge_p (edge, true)
1406 && want_inline_small_function_p (edge, true))
1407 edge->aux = fibheap_insert (heap, edge_badness (edge, false), edge);
1411 /* Remove EDGE from the fibheap. */
1413 static void
1414 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1416 if (e->callee)
1417 reset_node_growth_cache (e->callee);
1418 if (e->aux)
1420 fibheap_delete_node ((fibheap_t)data, (fibnode_t)e->aux);
1421 e->aux = NULL;
1425 /* Return true if speculation of edge E seems useful.
1426 If ANTICIPATE_INLINING is true, be conservative and hope that E
1427 may get inlined. */
1429 bool
1430 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1432 enum availability avail;
1433 struct cgraph_node *target = cgraph_function_or_thunk_node (e->callee, &avail);
1434 struct cgraph_edge *direct, *indirect;
1435 struct ipa_ref *ref;
1437 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1439 if (!cgraph_maybe_hot_edge_p (e))
1440 return false;
1442 /* See if IP optimizations found something potentially useful about the
1443 function. For now we look only for CONST/PURE flags. Almost everything
1444 else we propagate is useless. */
1445 if (avail >= AVAIL_AVAILABLE)
1447 int ecf_flags = flags_from_decl_or_type (target->symbol.decl);
1448 if (ecf_flags & ECF_CONST)
1450 cgraph_speculative_call_info (e, direct, indirect, ref);
1451 if (!(indirect->indirect_info->ecf_flags & ECF_CONST))
1452 return true;
1454 else if (ecf_flags & ECF_PURE)
1456 cgraph_speculative_call_info (e, direct, indirect, ref);
1457 if (!(indirect->indirect_info->ecf_flags & ECF_PURE))
1458 return true;
1461 /* If we did not managed to inline the function nor redirect
1462 to an ipa-cp clone (that are seen by having local flag set),
1463 it is probably pointless to inline it unless hardware is missing
1464 indirect call predictor. */
1465 if (!anticipate_inlining && e->inline_failed && !target->local.local)
1466 return false;
1467 /* For overwritable targets there is not much to do. */
1468 if (e->inline_failed && !can_inline_edge_p (e, false, true))
1469 return false;
1470 /* OK, speculation seems interesting. */
1471 return true;
1474 /* We know that EDGE is not going to be inlined.
1475 See if we can remove speculation. */
1477 static void
1478 resolve_noninline_speculation (fibheap_t edge_heap, struct cgraph_edge *edge)
1480 if (edge->speculative && !speculation_useful_p (edge, false))
1482 struct cgraph_node *node = edge->caller;
1483 struct cgraph_node *where = node->global.inlined_to
1484 ? node->global.inlined_to : node;
1485 bitmap updated_nodes = BITMAP_ALLOC (NULL);
1487 cgraph_resolve_speculation (edge, NULL);
1488 reset_edge_caches (where);
1489 inline_update_overall_summary (where);
1490 update_caller_keys (edge_heap, where,
1491 updated_nodes, NULL);
1492 update_callee_keys (edge_heap, where,
1493 updated_nodes);
1494 BITMAP_FREE (updated_nodes);
1498 /* We use greedy algorithm for inlining of small functions:
1499 All inline candidates are put into prioritized heap ordered in
1500 increasing badness.
1502 The inlining of small functions is bounded by unit growth parameters. */
1504 static void
1505 inline_small_functions (void)
1507 struct cgraph_node *node;
1508 struct cgraph_edge *edge;
1509 fibheap_t edge_heap = fibheap_new ();
1510 bitmap updated_nodes = BITMAP_ALLOC (NULL);
1511 int min_size, max_size;
1512 vec<cgraph_edge_p> new_indirect_edges = vNULL;
1513 int initial_size = 0;
1514 struct cgraph_node **order = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1515 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1517 if (flag_indirect_inlining)
1518 new_indirect_edges.create (8);
1520 edge_removal_hook_holder
1521 = cgraph_add_edge_removal_hook (&heap_edge_removal_hook, edge_heap);
1523 /* Compute overall unit size and other global parameters used by badness
1524 metrics. */
1526 max_count = 0;
1527 ipa_reduced_postorder (order, true, true, NULL);
1528 free (order);
1530 FOR_EACH_DEFINED_FUNCTION (node)
1531 if (!node->global.inlined_to)
1533 if (cgraph_function_with_gimple_body_p (node)
1534 || node->thunk.thunk_p)
1536 struct inline_summary *info = inline_summary (node);
1537 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->symbol.aux;
1539 if (!DECL_EXTERNAL (node->symbol.decl))
1540 initial_size += info->size;
1541 info->growth = estimate_growth (node);
1542 if (dfs && dfs->next_cycle)
1544 struct cgraph_node *n2;
1545 int id = dfs->scc_no + 1;
1546 for (n2 = node; n2;
1547 n2 = ((struct ipa_dfs_info *) node->symbol.aux)->next_cycle)
1549 struct inline_summary *info2 = inline_summary (n2);
1550 if (info2->scc_no)
1551 break;
1552 info2->scc_no = id;
1557 for (edge = node->callers; edge; edge = edge->next_caller)
1558 if (max_count < edge->count)
1559 max_count = edge->count;
1561 sreal_init (&max_count_real, max_count, 0);
1562 sreal_init (&max_relbenefit_real, RELATIVE_TIME_BENEFIT_RANGE, 0);
1563 sreal_init (&half_int_min_real, INT_MAX / 2, 0);
1564 ipa_free_postorder_info ();
1565 initialize_growth_caches ();
1567 if (dump_file)
1568 fprintf (dump_file,
1569 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1570 initial_size);
1572 overall_size = initial_size;
1573 max_size = compute_max_insns (overall_size);
1574 min_size = overall_size;
1576 /* Populate the heeap with all edges we might inline. */
1578 FOR_EACH_DEFINED_FUNCTION (node)
1580 bool update = false;
1581 struct cgraph_edge *next;
1583 if (dump_file)
1584 fprintf (dump_file, "Enqueueing calls in %s/%i.\n",
1585 cgraph_node_name (node), node->symbol.order);
1587 for (edge = node->callees; edge; edge = next)
1589 next = edge->next_callee;
1590 if (edge->inline_failed
1591 && !edge->aux
1592 && can_inline_edge_p (edge, true)
1593 && want_inline_small_function_p (edge, true)
1594 && edge->inline_failed)
1596 gcc_assert (!edge->aux);
1597 update_edge_key (edge_heap, edge);
1599 if (edge->speculative && !speculation_useful_p (edge, edge->aux != NULL))
1601 cgraph_resolve_speculation (edge, NULL);
1602 update = true;
1605 if (update)
1607 struct cgraph_node *where = node->global.inlined_to
1608 ? node->global.inlined_to : node;
1609 inline_update_overall_summary (where);
1610 reset_node_growth_cache (where);
1611 reset_edge_caches (where);
1612 update_caller_keys (edge_heap, where,
1613 updated_nodes, NULL);
1614 bitmap_clear (updated_nodes);
1618 gcc_assert (in_lto_p
1619 || !max_count
1620 || (profile_info && flag_branch_probabilities));
1622 while (!fibheap_empty (edge_heap))
1624 int old_size = overall_size;
1625 struct cgraph_node *where, *callee;
1626 int badness = fibheap_min_key (edge_heap);
1627 int current_badness;
1628 int cached_badness;
1629 int growth;
1631 edge = (struct cgraph_edge *) fibheap_extract_min (edge_heap);
1632 gcc_assert (edge->aux);
1633 edge->aux = NULL;
1634 if (!edge->inline_failed)
1635 continue;
1637 /* Be sure that caches are maintained consistent.
1638 We can not make this ENABLE_CHECKING only because it cause different
1639 updates of the fibheap queue. */
1640 cached_badness = edge_badness (edge, false);
1641 reset_edge_growth_cache (edge);
1642 reset_node_growth_cache (edge->callee);
1644 /* When updating the edge costs, we only decrease badness in the keys.
1645 Increases of badness are handled lazilly; when we see key with out
1646 of date value on it, we re-insert it now. */
1647 current_badness = edge_badness (edge, false);
1648 gcc_assert (cached_badness == current_badness);
1649 gcc_assert (current_badness >= badness);
1650 if (current_badness != badness)
1652 edge->aux = fibheap_insert (edge_heap, current_badness, edge);
1653 continue;
1656 if (!can_inline_edge_p (edge, true))
1658 resolve_noninline_speculation (edge_heap, edge);
1659 continue;
1662 callee = cgraph_function_or_thunk_node (edge->callee, NULL);
1663 growth = estimate_edge_growth (edge);
1664 if (dump_file)
1666 fprintf (dump_file,
1667 "\nConsidering %s/%i with %i size\n",
1668 cgraph_node_name (callee), callee->symbol.order,
1669 inline_summary (callee)->size);
1670 fprintf (dump_file,
1671 " to be inlined into %s/%i in %s:%i\n"
1672 " Estimated growth after inlined into all is %+i insns.\n"
1673 " Estimated badness is %i, frequency %.2f.\n",
1674 cgraph_node_name (edge->caller), edge->caller->symbol.order,
1675 flag_wpa ? "unknown"
1676 : gimple_filename ((const_gimple) edge->call_stmt),
1677 flag_wpa ? -1
1678 : gimple_lineno ((const_gimple) edge->call_stmt),
1679 estimate_growth (callee),
1680 badness,
1681 edge->frequency / (double)CGRAPH_FREQ_BASE);
1682 if (edge->count)
1683 fprintf (dump_file," Called "HOST_WIDEST_INT_PRINT_DEC"x\n",
1684 edge->count);
1685 if (dump_flags & TDF_DETAILS)
1686 edge_badness (edge, true);
1689 if (overall_size + growth > max_size
1690 && !DECL_DISREGARD_INLINE_LIMITS (callee->symbol.decl))
1692 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
1693 report_inline_failed_reason (edge);
1694 resolve_noninline_speculation (edge_heap, edge);
1695 continue;
1698 if (!want_inline_small_function_p (edge, true))
1700 resolve_noninline_speculation (edge_heap, edge);
1701 continue;
1704 /* Heuristics for inlining small functions works poorly for
1705 recursive calls where we do efect similar to loop unrolling.
1706 When inliing such edge seems profitable, leave decision on
1707 specific inliner. */
1708 if (cgraph_edge_recursive_p (edge))
1710 where = edge->caller;
1711 if (where->global.inlined_to)
1712 where = where->global.inlined_to;
1713 if (!recursive_inlining (edge,
1714 flag_indirect_inlining
1715 ? &new_indirect_edges : NULL))
1717 edge->inline_failed = CIF_RECURSIVE_INLINING;
1718 resolve_noninline_speculation (edge_heap, edge);
1719 continue;
1721 reset_edge_caches (where);
1722 /* Recursive inliner inlines all recursive calls of the function
1723 at once. Consequently we need to update all callee keys. */
1724 if (flag_indirect_inlining)
1725 add_new_edges_to_heap (edge_heap, new_indirect_edges);
1726 update_callee_keys (edge_heap, where, updated_nodes);
1727 bitmap_clear (updated_nodes);
1729 else
1731 struct cgraph_node *outer_node = NULL;
1732 int depth = 0;
1734 /* Consider the case where self recursive function A is inlined into B.
1735 This is desired optimization in some cases, since it leads to effect
1736 similar of loop peeling and we might completely optimize out the
1737 recursive call. However we must be extra selective. */
1739 where = edge->caller;
1740 while (where->global.inlined_to)
1742 if (where->symbol.decl == callee->symbol.decl)
1743 outer_node = where, depth++;
1744 where = where->callers->caller;
1746 if (outer_node
1747 && !want_inline_self_recursive_call_p (edge, outer_node,
1748 true, depth))
1750 edge->inline_failed
1751 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->symbol.decl)
1752 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
1753 resolve_noninline_speculation (edge_heap, edge);
1754 continue;
1756 else if (depth && dump_file)
1757 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
1759 gcc_checking_assert (!callee->global.inlined_to);
1760 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
1761 if (flag_indirect_inlining)
1762 add_new_edges_to_heap (edge_heap, new_indirect_edges);
1764 reset_edge_caches (edge->callee);
1765 reset_node_growth_cache (callee);
1767 update_callee_keys (edge_heap, where, updated_nodes);
1769 where = edge->caller;
1770 if (where->global.inlined_to)
1771 where = where->global.inlined_to;
1773 /* Our profitability metric can depend on local properties
1774 such as number of inlinable calls and size of the function body.
1775 After inlining these properties might change for the function we
1776 inlined into (since it's body size changed) and for the functions
1777 called by function we inlined (since number of it inlinable callers
1778 might change). */
1779 update_caller_keys (edge_heap, where, updated_nodes, NULL);
1780 bitmap_clear (updated_nodes);
1782 if (dump_file)
1784 fprintf (dump_file,
1785 " Inlined into %s which now has time %i and size %i,"
1786 "net change of %+i.\n",
1787 cgraph_node_name (edge->caller),
1788 inline_summary (edge->caller)->time,
1789 inline_summary (edge->caller)->size,
1790 overall_size - old_size);
1792 if (min_size > overall_size)
1794 min_size = overall_size;
1795 max_size = compute_max_insns (min_size);
1797 if (dump_file)
1798 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
1802 free_growth_caches ();
1803 new_indirect_edges.release ();
1804 fibheap_delete (edge_heap);
1805 if (dump_file)
1806 fprintf (dump_file,
1807 "Unit growth for small function inlining: %i->%i (%i%%)\n",
1808 initial_size, overall_size,
1809 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
1810 BITMAP_FREE (updated_nodes);
1811 cgraph_remove_edge_removal_hook (edge_removal_hook_holder);
1814 /* Flatten NODE. Performed both during early inlining and
1815 at IPA inlining time. */
1817 static void
1818 flatten_function (struct cgraph_node *node, bool early)
1820 struct cgraph_edge *e;
1822 /* We shouldn't be called recursively when we are being processed. */
1823 gcc_assert (node->symbol.aux == NULL);
1825 node->symbol.aux = (void *) node;
1827 for (e = node->callees; e; e = e->next_callee)
1829 struct cgraph_node *orig_callee;
1830 struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL);
1832 /* We've hit cycle? It is time to give up. */
1833 if (callee->symbol.aux)
1835 if (dump_file)
1836 fprintf (dump_file,
1837 "Not inlining %s into %s to avoid cycle.\n",
1838 xstrdup (cgraph_node_name (callee)),
1839 xstrdup (cgraph_node_name (e->caller)));
1840 e->inline_failed = CIF_RECURSIVE_INLINING;
1841 continue;
1844 /* When the edge is already inlined, we just need to recurse into
1845 it in order to fully flatten the leaves. */
1846 if (!e->inline_failed)
1848 flatten_function (callee, early);
1849 continue;
1852 /* Flatten attribute needs to be processed during late inlining. For
1853 extra code quality we however do flattening during early optimization,
1854 too. */
1855 if (!early
1856 ? !can_inline_edge_p (e, true)
1857 : !can_early_inline_edge_p (e))
1858 continue;
1860 if (cgraph_edge_recursive_p (e))
1862 if (dump_file)
1863 fprintf (dump_file, "Not inlining: recursive call.\n");
1864 continue;
1867 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->symbol.decl))
1868 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->symbol.decl)))
1870 if (dump_file)
1871 fprintf (dump_file, "Not inlining: SSA form does not match.\n");
1872 continue;
1875 /* Inline the edge and flatten the inline clone. Avoid
1876 recursing through the original node if the node was cloned. */
1877 if (dump_file)
1878 fprintf (dump_file, " Inlining %s into %s.\n",
1879 xstrdup (cgraph_node_name (callee)),
1880 xstrdup (cgraph_node_name (e->caller)));
1881 orig_callee = callee;
1882 inline_call (e, true, NULL, NULL, false);
1883 if (e->callee != orig_callee)
1884 orig_callee->symbol.aux = (void *) node;
1885 flatten_function (e->callee, early);
1886 if (e->callee != orig_callee)
1887 orig_callee->symbol.aux = NULL;
1890 node->symbol.aux = NULL;
1891 if (!node->global.inlined_to)
1892 inline_update_overall_summary (node);
1895 /* Decide on the inlining. We do so in the topological order to avoid
1896 expenses on updating data structures. */
1898 static unsigned int
1899 ipa_inline (void)
1901 struct cgraph_node *node;
1902 int nnodes;
1903 struct cgraph_node **order =
1904 XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1905 int i;
1906 int cold;
1908 if (in_lto_p && optimize)
1909 ipa_update_after_lto_read ();
1911 if (dump_file)
1912 dump_inline_summaries (dump_file);
1914 nnodes = ipa_reverse_postorder (order);
1916 FOR_EACH_FUNCTION (node)
1917 node->symbol.aux = 0;
1919 if (dump_file)
1920 fprintf (dump_file, "\nFlattening functions:\n");
1922 /* In the first pass handle functions to be flattened. Do this with
1923 a priority so none of our later choices will make this impossible. */
1924 for (i = nnodes - 1; i >= 0; i--)
1926 node = order[i];
1928 /* Handle nodes to be flattened.
1929 Ideally when processing callees we stop inlining at the
1930 entry of cycles, possibly cloning that entry point and
1931 try to flatten itself turning it into a self-recursive
1932 function. */
1933 if (lookup_attribute ("flatten",
1934 DECL_ATTRIBUTES (node->symbol.decl)) != NULL)
1936 if (dump_file)
1937 fprintf (dump_file,
1938 "Flattening %s\n", cgraph_node_name (node));
1939 flatten_function (node, false);
1943 inline_small_functions ();
1945 /* Do first after-inlining removal. We want to remove all "stale" extern inline
1946 functions and virtual functions so we really know what is called once. */
1947 symtab_remove_unreachable_nodes (false, dump_file);
1948 free (order);
1950 /* Inline functions with a property that after inlining into all callers the
1951 code size will shrink because the out-of-line copy is eliminated.
1952 We do this regardless on the callee size as long as function growth limits
1953 are met. */
1954 if (dump_file)
1955 fprintf (dump_file,
1956 "\nDeciding on functions to be inlined into all callers and removing useless speculations:\n");
1958 /* Inlining one function called once has good chance of preventing
1959 inlining other function into the same callee. Ideally we should
1960 work in priority order, but probably inlining hot functions first
1961 is good cut without the extra pain of maintaining the queue.
1963 ??? this is not really fitting the bill perfectly: inlining function
1964 into callee often leads to better optimization of callee due to
1965 increased context for optimization.
1966 For example if main() function calls a function that outputs help
1967 and then function that does the main optmization, we should inline
1968 the second with priority even if both calls are cold by themselves.
1970 We probably want to implement new predicate replacing our use of
1971 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
1972 to be hot. */
1973 for (cold = 0; cold <= 1; cold ++)
1975 FOR_EACH_DEFINED_FUNCTION (node)
1977 struct cgraph_edge *edge, *next;
1978 bool update=false;
1980 for (edge = node->callees; edge; edge = next)
1982 next = edge->next_callee;
1983 if (edge->speculative && !speculation_useful_p (edge, false))
1985 cgraph_resolve_speculation (edge, NULL);
1986 update = true;
1989 if (update)
1991 struct cgraph_node *where = node->global.inlined_to
1992 ? node->global.inlined_to : node;
1993 reset_node_growth_cache (where);
1994 reset_edge_caches (where);
1995 inline_update_overall_summary (where);
1997 if (flag_inline_functions_called_once
1998 && want_inline_function_to_all_callers_p (node, cold))
2000 int num_calls = 0;
2001 struct cgraph_edge *e;
2002 for (e = node->callers; e; e = e->next_caller)
2003 num_calls++;
2004 while (node->callers && !node->global.inlined_to)
2006 struct cgraph_node *caller = node->callers->caller;
2008 if (dump_file)
2010 fprintf (dump_file,
2011 "\nInlining %s size %i.\n",
2012 cgraph_node_name (node),
2013 inline_summary (node)->size);
2014 fprintf (dump_file,
2015 " Called once from %s %i insns.\n",
2016 cgraph_node_name (node->callers->caller),
2017 inline_summary (node->callers->caller)->size);
2020 inline_call (node->callers, true, NULL, NULL, true);
2021 if (dump_file)
2022 fprintf (dump_file,
2023 " Inlined into %s which now has %i size\n",
2024 cgraph_node_name (caller),
2025 inline_summary (caller)->size);
2026 if (!num_calls--)
2028 if (dump_file)
2029 fprintf (dump_file, "New calls found; giving up.\n");
2030 break;
2037 /* Free ipa-prop structures if they are no longer needed. */
2038 if (optimize)
2039 ipa_free_all_structures_after_iinln ();
2041 if (dump_file)
2042 fprintf (dump_file,
2043 "\nInlined %i calls, eliminated %i functions\n\n",
2044 ncalls_inlined, nfunctions_inlined);
2046 if (dump_file)
2047 dump_inline_summaries (dump_file);
2048 /* In WPA we use inline summaries for partitioning process. */
2049 if (!flag_wpa)
2050 inline_free_summary ();
2051 return 0;
2054 /* Inline always-inline function calls in NODE. */
2056 static bool
2057 inline_always_inline_functions (struct cgraph_node *node)
2059 struct cgraph_edge *e;
2060 bool inlined = false;
2062 for (e = node->callees; e; e = e->next_callee)
2064 struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL);
2065 if (!DECL_DISREGARD_INLINE_LIMITS (callee->symbol.decl))
2066 continue;
2068 if (cgraph_edge_recursive_p (e))
2070 if (dump_file)
2071 fprintf (dump_file, " Not inlining recursive call to %s.\n",
2072 cgraph_node_name (e->callee));
2073 e->inline_failed = CIF_RECURSIVE_INLINING;
2074 continue;
2077 if (!can_early_inline_edge_p (e))
2079 /* Set inlined to true if the callee is marked "always_inline" but
2080 is not inlinable. This will allow flagging an error later in
2081 expand_call_inline in tree-inline.c. */
2082 if (lookup_attribute ("always_inline",
2083 DECL_ATTRIBUTES (callee->symbol.decl)) != NULL)
2084 inlined = true;
2085 continue;
2088 if (dump_file)
2089 fprintf (dump_file, " Inlining %s into %s (always_inline).\n",
2090 xstrdup (cgraph_node_name (e->callee)),
2091 xstrdup (cgraph_node_name (e->caller)));
2092 inline_call (e, true, NULL, NULL, false);
2093 inlined = true;
2095 if (inlined)
2096 inline_update_overall_summary (node);
2098 return inlined;
2101 /* Decide on the inlining. We do so in the topological order to avoid
2102 expenses on updating data structures. */
2104 static bool
2105 early_inline_small_functions (struct cgraph_node *node)
2107 struct cgraph_edge *e;
2108 bool inlined = false;
2110 for (e = node->callees; e; e = e->next_callee)
2112 struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL);
2113 if (!inline_summary (callee)->inlinable
2114 || !e->inline_failed)
2115 continue;
2117 /* Do not consider functions not declared inline. */
2118 if (!DECL_DECLARED_INLINE_P (callee->symbol.decl)
2119 && !flag_inline_small_functions
2120 && !flag_inline_functions)
2121 continue;
2123 if (dump_file)
2124 fprintf (dump_file, "Considering inline candidate %s.\n",
2125 cgraph_node_name (callee));
2127 if (!can_early_inline_edge_p (e))
2128 continue;
2130 if (cgraph_edge_recursive_p (e))
2132 if (dump_file)
2133 fprintf (dump_file, " Not inlining: recursive call.\n");
2134 continue;
2137 if (!want_early_inline_function_p (e))
2138 continue;
2140 if (dump_file)
2141 fprintf (dump_file, " Inlining %s into %s.\n",
2142 xstrdup (cgraph_node_name (callee)),
2143 xstrdup (cgraph_node_name (e->caller)));
2144 inline_call (e, true, NULL, NULL, true);
2145 inlined = true;
2148 return inlined;
2151 /* Do inlining of small functions. Doing so early helps profiling and other
2152 passes to be somewhat more effective and avoids some code duplication in
2153 later real inlining pass for testcases with very many function calls. */
2154 static unsigned int
2155 early_inliner (void)
2157 struct cgraph_node *node = cgraph_get_node (current_function_decl);
2158 struct cgraph_edge *edge;
2159 unsigned int todo = 0;
2160 int iterations = 0;
2161 bool inlined = false;
2163 if (seen_error ())
2164 return 0;
2166 /* Do nothing if datastructures for ipa-inliner are already computed. This
2167 happens when some pass decides to construct new function and
2168 cgraph_add_new_function calls lowering passes and early optimization on
2169 it. This may confuse ourself when early inliner decide to inline call to
2170 function clone, because function clones don't have parameter list in
2171 ipa-prop matching their signature. */
2172 if (ipa_node_params_vector.exists ())
2173 return 0;
2175 #ifdef ENABLE_CHECKING
2176 verify_cgraph_node (node);
2177 #endif
2178 ipa_remove_all_references (&node->symbol.ref_list);
2180 /* Even when not optimizing or not inlining inline always-inline
2181 functions. */
2182 inlined = inline_always_inline_functions (node);
2184 if (!optimize
2185 || flag_no_inline
2186 || !flag_early_inlining
2187 /* Never inline regular functions into always-inline functions
2188 during incremental inlining. This sucks as functions calling
2189 always inline functions will get less optimized, but at the
2190 same time inlining of functions calling always inline
2191 function into an always inline function might introduce
2192 cycles of edges to be always inlined in the callgraph.
2194 We might want to be smarter and just avoid this type of inlining. */
2195 || DECL_DISREGARD_INLINE_LIMITS (node->symbol.decl))
2197 else if (lookup_attribute ("flatten",
2198 DECL_ATTRIBUTES (node->symbol.decl)) != NULL)
2200 /* When the function is marked to be flattened, recursively inline
2201 all calls in it. */
2202 if (dump_file)
2203 fprintf (dump_file,
2204 "Flattening %s\n", cgraph_node_name (node));
2205 flatten_function (node, true);
2206 inlined = true;
2208 else
2210 /* We iterate incremental inlining to get trivial cases of indirect
2211 inlining. */
2212 while (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS)
2213 && early_inline_small_functions (node))
2215 timevar_push (TV_INTEGRATION);
2216 todo |= optimize_inline_calls (current_function_decl);
2218 /* Technically we ought to recompute inline parameters so the new
2219 iteration of early inliner works as expected. We however have
2220 values approximately right and thus we only need to update edge
2221 info that might be cleared out for newly discovered edges. */
2222 for (edge = node->callees; edge; edge = edge->next_callee)
2224 struct inline_edge_summary *es = inline_edge_summary (edge);
2225 es->call_stmt_size
2226 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2227 es->call_stmt_time
2228 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2229 if (edge->callee->symbol.decl
2230 && !gimple_check_call_matching_types (
2231 edge->call_stmt, edge->callee->symbol.decl, false))
2232 edge->call_stmt_cannot_inline_p = true;
2234 timevar_pop (TV_INTEGRATION);
2235 iterations++;
2236 inlined = false;
2238 if (dump_file)
2239 fprintf (dump_file, "Iterations: %i\n", iterations);
2242 if (inlined)
2244 timevar_push (TV_INTEGRATION);
2245 todo |= optimize_inline_calls (current_function_decl);
2246 timevar_pop (TV_INTEGRATION);
2249 cfun->always_inline_functions_inlined = true;
2251 return todo;
2254 namespace {
2256 const pass_data pass_data_early_inline =
2258 GIMPLE_PASS, /* type */
2259 "einline", /* name */
2260 OPTGROUP_INLINE, /* optinfo_flags */
2261 false, /* has_gate */
2262 true, /* has_execute */
2263 TV_EARLY_INLINING, /* tv_id */
2264 PROP_ssa, /* properties_required */
2265 0, /* properties_provided */
2266 0, /* properties_destroyed */
2267 0, /* todo_flags_start */
2268 0, /* todo_flags_finish */
2271 class pass_early_inline : public gimple_opt_pass
2273 public:
2274 pass_early_inline(gcc::context *ctxt)
2275 : gimple_opt_pass(pass_data_early_inline, ctxt)
2278 /* opt_pass methods: */
2279 unsigned int execute () { return early_inliner (); }
2281 }; // class pass_early_inline
2283 } // anon namespace
2285 gimple_opt_pass *
2286 make_pass_early_inline (gcc::context *ctxt)
2288 return new pass_early_inline (ctxt);
2292 /* When to run IPA inlining. Inlining of always-inline functions
2293 happens during early inlining.
2295 Enable inlining unconditoinally at -flto. We need size estimates to
2296 drive partitioning. */
2298 static bool
2299 gate_ipa_inline (void)
2301 return optimize || flag_lto || flag_wpa;
2304 namespace {
2306 const pass_data pass_data_ipa_inline =
2308 IPA_PASS, /* type */
2309 "inline", /* name */
2310 OPTGROUP_INLINE, /* optinfo_flags */
2311 true, /* has_gate */
2312 true, /* has_execute */
2313 TV_IPA_INLINING, /* tv_id */
2314 0, /* properties_required */
2315 0, /* properties_provided */
2316 0, /* properties_destroyed */
2317 TODO_remove_functions, /* todo_flags_start */
2318 ( TODO_dump_symtab | TODO_remove_functions ), /* todo_flags_finish */
2321 class pass_ipa_inline : public ipa_opt_pass_d
2323 public:
2324 pass_ipa_inline(gcc::context *ctxt)
2325 : ipa_opt_pass_d(pass_data_ipa_inline, ctxt,
2326 inline_generate_summary, /* generate_summary */
2327 inline_write_summary, /* write_summary */
2328 inline_read_summary, /* read_summary */
2329 NULL, /* write_optimization_summary */
2330 NULL, /* read_optimization_summary */
2331 NULL, /* stmt_fixup */
2332 0, /* function_transform_todo_flags_start */
2333 inline_transform, /* function_transform */
2334 NULL) /* variable_transform */
2337 /* opt_pass methods: */
2338 bool gate () { return gate_ipa_inline (); }
2339 unsigned int execute () { return ipa_inline (); }
2341 }; // class pass_ipa_inline
2343 } // anon namespace
2345 ipa_opt_pass_d *
2346 make_pass_ipa_inline (gcc::context *ctxt)
2348 return new pass_ipa_inline (ctxt);