1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2018 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
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
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
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
38 The inliner itself is split into two passes:
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
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
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.
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. */
94 #include "coretypes.h"
100 #include "alloc-pool.h"
101 #include "tree-pass.h"
102 #include "gimple-ssa.h"
104 #include "lto-streamer.h"
105 #include "trans-mem.h"
107 #include "tree-inline.h"
110 #include "symbol-summary.h"
111 #include "tree-vrp.h"
112 #include "ipa-prop.h"
113 #include "ipa-fnsummary.h"
114 #include "ipa-inline.h"
115 #include "ipa-utils.h"
117 #include "auto-profile.h"
118 #include "builtins.h"
119 #include "fibonacci_heap.h"
120 #include "stringpool.h"
124 typedef fibonacci_heap <sreal, cgraph_edge> edge_heap_t;
125 typedef fibonacci_node <sreal, cgraph_edge> edge_heap_node_t;
127 /* Statistics we collect about inlining algorithm. */
128 static int overall_size;
129 static profile_count max_count;
130 static profile_count spec_rem;
132 /* Return false when inlining edge E would lead to violating
133 limits on function unit growth or stack usage growth.
135 The relative function body growth limit is present generally
136 to avoid problems with non-linear behavior of the compiler.
137 To allow inlining huge functions into tiny wrapper, the limit
138 is always based on the bigger of the two functions considered.
140 For stack growth limits we always base the growth in stack usage
141 of the callers. We want to prevent applications from segfaulting
142 on stack overflow when functions with huge stack frames gets
146 caller_growth_limits (struct cgraph_edge *e)
148 struct cgraph_node *to = e->caller;
149 struct cgraph_node *what = e->callee->ultimate_alias_target ();
152 HOST_WIDE_INT stack_size_limit = 0, inlined_stack;
153 ipa_fn_summary *info, *what_info, *outer_info = ipa_fn_summaries->get (to);
155 /* Look for function e->caller is inlined to. While doing
156 so work out the largest function body on the way. As
157 described above, we want to base our function growth
158 limits based on that. Not on the self size of the
159 outer function, not on the self size of inline code
160 we immediately inline to. This is the most relaxed
161 interpretation of the rule "do not grow large functions
162 too much in order to prevent compiler from exploding". */
165 info = ipa_fn_summaries->get (to);
166 if (limit < info->self_size)
167 limit = info->self_size;
168 if (stack_size_limit < info->estimated_self_stack_size)
169 stack_size_limit = info->estimated_self_stack_size;
170 if (to->global.inlined_to)
171 to = to->callers->caller;
176 what_info = ipa_fn_summaries->get (what);
178 if (limit < what_info->self_size)
179 limit = what_info->self_size;
181 limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100;
183 /* Check the size after inlining against the function limits. But allow
184 the function to shrink if it went over the limits by forced inlining. */
185 newsize = estimate_size_after_inlining (to, e);
186 if (newsize >= info->size
187 && newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS)
190 e->inline_failed = CIF_LARGE_FUNCTION_GROWTH_LIMIT;
194 if (!what_info->estimated_stack_size)
197 /* FIXME: Stack size limit often prevents inlining in Fortran programs
198 due to large i/o datastructures used by the Fortran front-end.
199 We ought to ignore this limit when we know that the edge is executed
200 on every invocation of the caller (i.e. its call statement dominates
201 exit block). We do not track this information, yet. */
202 stack_size_limit += ((gcov_type)stack_size_limit
203 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH) / 100);
205 inlined_stack = (outer_info->stack_frame_offset
206 + outer_info->estimated_self_stack_size
207 + what_info->estimated_stack_size);
208 /* Check new stack consumption with stack consumption at the place
210 if (inlined_stack > stack_size_limit
211 /* If function already has large stack usage from sibling
212 inline call, we can inline, too.
213 This bit overoptimistically assume that we are good at stack
215 && inlined_stack > info->estimated_stack_size
216 && inlined_stack > PARAM_VALUE (PARAM_LARGE_STACK_FRAME))
218 e->inline_failed = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT;
224 /* Dump info about why inlining has failed. */
227 report_inline_failed_reason (struct cgraph_edge *e)
231 fprintf (dump_file, " not inlinable: %s -> %s, %s\n",
232 e->caller->dump_name (),
233 e->callee->dump_name (),
234 cgraph_inline_failed_string (e->inline_failed));
235 if ((e->inline_failed == CIF_TARGET_OPTION_MISMATCH
236 || e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
237 && e->caller->lto_file_data
238 && e->callee->ultimate_alias_target ()->lto_file_data)
240 fprintf (dump_file, " LTO objects: %s, %s\n",
241 e->caller->lto_file_data->file_name,
242 e->callee->ultimate_alias_target ()->lto_file_data->file_name);
244 if (e->inline_failed == CIF_TARGET_OPTION_MISMATCH)
245 cl_target_option_print_diff
246 (dump_file, 2, target_opts_for_fn (e->caller->decl),
247 target_opts_for_fn (e->callee->ultimate_alias_target ()->decl));
248 if (e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
249 cl_optimization_print_diff
250 (dump_file, 2, opts_for_fn (e->caller->decl),
251 opts_for_fn (e->callee->ultimate_alias_target ()->decl));
255 /* Decide whether sanitizer-related attributes allow inlining. */
258 sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
260 if (!caller || !callee)
263 /* Allow inlining always_inline functions into no_sanitize_address
265 if (!sanitize_flags_p (SANITIZE_ADDRESS, caller)
266 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
269 return ((sanitize_flags_p (SANITIZE_ADDRESS, caller)
270 == sanitize_flags_p (SANITIZE_ADDRESS, callee))
271 && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller)
272 == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee))
273 && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller)
274 == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee)));
277 /* Used for flags where it is safe to inline when caller's value is
278 grater than callee's. */
279 #define check_maybe_up(flag) \
280 (opts_for_fn (caller->decl)->x_##flag \
281 != opts_for_fn (callee->decl)->x_##flag \
283 || opts_for_fn (caller->decl)->x_##flag \
284 < opts_for_fn (callee->decl)->x_##flag))
285 /* Used for flags where it is safe to inline when caller's value is
286 smaller than callee's. */
287 #define check_maybe_down(flag) \
288 (opts_for_fn (caller->decl)->x_##flag \
289 != opts_for_fn (callee->decl)->x_##flag \
291 || opts_for_fn (caller->decl)->x_##flag \
292 > opts_for_fn (callee->decl)->x_##flag))
293 /* Used for flags where exact match is needed for correctness. */
294 #define check_match(flag) \
295 (opts_for_fn (caller->decl)->x_##flag \
296 != opts_for_fn (callee->decl)->x_##flag)
298 /* Decide if we can inline the edge and possibly update
299 inline_failed reason.
300 We check whether inlining is possible at all and whether
301 caller growth limits allow doing so.
303 if REPORT is true, output reason to the dump file. */
306 can_inline_edge_p (struct cgraph_edge *e, bool report,
309 gcc_checking_assert (e->inline_failed);
311 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
314 report_inline_failed_reason (e);
318 bool inlinable = true;
319 enum availability avail;
320 cgraph_node *caller = e->caller->global.inlined_to
321 ? e->caller->global.inlined_to : e->caller;
322 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
324 if (!callee->definition)
326 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
329 if (!early && (!opt_for_fn (callee->decl, optimize)
330 || !opt_for_fn (caller->decl, optimize)))
332 e->inline_failed = CIF_FUNCTION_NOT_OPTIMIZED;
335 else if (callee->calls_comdat_local)
337 e->inline_failed = CIF_USES_COMDAT_LOCAL;
340 else if (avail <= AVAIL_INTERPOSABLE)
342 e->inline_failed = CIF_OVERWRITABLE;
345 /* All edges with call_stmt_cannot_inline_p should have inline_failed
346 initialized to one of FINAL_ERROR reasons. */
347 else if (e->call_stmt_cannot_inline_p)
349 /* Don't inline if the functions have different EH personalities. */
350 else if (DECL_FUNCTION_PERSONALITY (caller->decl)
351 && DECL_FUNCTION_PERSONALITY (callee->decl)
352 && (DECL_FUNCTION_PERSONALITY (caller->decl)
353 != DECL_FUNCTION_PERSONALITY (callee->decl)))
355 e->inline_failed = CIF_EH_PERSONALITY;
358 /* TM pure functions should not be inlined into non-TM_pure
360 else if (is_tm_pure (callee->decl) && !is_tm_pure (caller->decl))
362 e->inline_failed = CIF_UNSPECIFIED;
365 /* Check compatibility of target optimization options. */
366 else if (!targetm.target_option.can_inline_p (caller->decl,
369 e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
372 else if (!ipa_fn_summaries->get (callee)->inlinable)
374 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
377 /* Don't inline a function with mismatched sanitization attributes. */
378 else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
380 e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
383 if (!inlinable && report)
384 report_inline_failed_reason (e);
388 /* Decide if we can inline the edge and possibly update
389 inline_failed reason.
390 We check whether inlining is possible at all and whether
391 caller growth limits allow doing so.
393 if REPORT is true, output reason to the dump file.
395 if DISREGARD_LIMITS is true, ignore size limits. */
398 can_inline_edge_by_limits_p (struct cgraph_edge *e, bool report,
399 bool disregard_limits = false, bool early = false)
401 gcc_checking_assert (e->inline_failed);
403 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
406 report_inline_failed_reason (e);
410 bool inlinable = true;
411 enum availability avail;
412 cgraph_node *caller = e->caller->global.inlined_to
413 ? e->caller->global.inlined_to : e->caller;
414 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
415 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl);
417 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL;
418 /* Check if caller growth allows the inlining. */
419 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
421 && !lookup_attribute ("flatten",
422 DECL_ATTRIBUTES (caller->decl))
423 && !caller_growth_limits (e))
425 /* Don't inline a function with a higher optimization level than the
426 caller. FIXME: this is really just tip of iceberg of handling
427 optimization attribute. */
428 else if (caller_tree != callee_tree)
431 (DECL_DISREGARD_INLINE_LIMITS (callee->decl)
432 && lookup_attribute ("always_inline",
433 DECL_ATTRIBUTES (callee->decl)));
434 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
435 ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
437 /* Until GCC 4.9 we did not check the semantics alterning flags
438 bellow and inline across optimization boundry.
439 Enabling checks bellow breaks several packages by refusing
440 to inline library always_inline functions. See PR65873.
441 Disable the check for early inlining for now until better solution
443 if (always_inline && early)
445 /* There are some options that change IL semantics which means
446 we cannot inline in these cases for correctness reason.
447 Not even for always_inline declared functions. */
448 else if (check_match (flag_wrapv)
449 || check_match (flag_trapv)
450 || check_match (flag_pcc_struct_return)
451 /* When caller or callee does FP math, be sure FP codegen flags
453 || ((caller_info->fp_expressions && callee_info->fp_expressions)
454 && (check_maybe_up (flag_rounding_math)
455 || check_maybe_up (flag_trapping_math)
456 || check_maybe_down (flag_unsafe_math_optimizations)
457 || check_maybe_down (flag_finite_math_only)
458 || check_maybe_up (flag_signaling_nans)
459 || check_maybe_down (flag_cx_limited_range)
460 || check_maybe_up (flag_signed_zeros)
461 || check_maybe_down (flag_associative_math)
462 || check_maybe_down (flag_reciprocal_math)
463 || check_maybe_down (flag_fp_int_builtin_inexact)
464 /* Strictly speaking only when the callee contains function
465 calls that may end up setting errno. */
466 || check_maybe_up (flag_errno_math)))
467 /* We do not want to make code compiled with exceptions to be
468 brought into a non-EH function unless we know that the callee
470 This is tracked by DECL_FUNCTION_PERSONALITY. */
471 || (check_maybe_up (flag_non_call_exceptions)
472 && DECL_FUNCTION_PERSONALITY (callee->decl))
473 || (check_maybe_up (flag_exceptions)
474 && DECL_FUNCTION_PERSONALITY (callee->decl))
475 /* When devirtualization is diabled for callee, it is not safe
476 to inline it as we possibly mangled the type info.
477 Allow early inlining of always inlines. */
478 || (!early && check_maybe_down (flag_devirtualize)))
480 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
483 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
484 else if (always_inline)
486 /* When user added an attribute to the callee honor it. */
487 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee->decl))
488 && opts_for_fn (caller->decl) != opts_for_fn (callee->decl))
490 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
493 /* If explicit optimize attribute are not used, the mismatch is caused
494 by different command line options used to build different units.
495 Do not care about COMDAT functions - those are intended to be
496 optimized with the optimization flags of module they are used in.
497 Also do not care about mixing up size/speed optimization when
498 DECL_DISREGARD_INLINE_LIMITS is set. */
499 else if ((callee->merged_comdat
500 && !lookup_attribute ("optimize",
501 DECL_ATTRIBUTES (caller->decl)))
502 || DECL_DISREGARD_INLINE_LIMITS (callee->decl))
504 /* If mismatch is caused by merging two LTO units with different
505 optimizationflags we want to be bit nicer. However never inline
506 if one of functions is not optimized at all. */
507 else if (!opt_for_fn (callee->decl, optimize)
508 || !opt_for_fn (caller->decl, optimize))
510 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
513 /* If callee is optimized for size and caller is not, allow inlining if
514 code shrinks or we are in MAX_INLINE_INSNS_SINGLE limit and callee
515 is inline (and thus likely an unified comdat). This will allow caller
517 else if (opt_for_fn (callee->decl, optimize_size)
518 > opt_for_fn (caller->decl, optimize_size))
520 int growth = estimate_edge_growth (e);
522 && (!DECL_DECLARED_INLINE_P (callee->decl)
523 && growth >= MAX (MAX_INLINE_INSNS_SINGLE,
524 MAX_INLINE_INSNS_AUTO)))
526 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
530 /* If callee is more aggressively optimized for performance than caller,
531 we generally want to inline only cheap (runtime wise) functions. */
532 else if (opt_for_fn (callee->decl, optimize_size)
533 < opt_for_fn (caller->decl, optimize_size)
534 || (opt_for_fn (callee->decl, optimize)
535 > opt_for_fn (caller->decl, optimize)))
537 if (estimate_edge_time (e)
538 >= 20 + ipa_call_summaries->get (e)->call_stmt_time)
540 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
547 if (!inlinable && report)
548 report_inline_failed_reason (e);
553 /* Return true if the edge E is inlinable during early inlining. */
556 can_early_inline_edge_p (struct cgraph_edge *e)
558 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
559 /* Early inliner might get called at WPA stage when IPA pass adds new
560 function. In this case we can not really do any of early inlining
561 because function bodies are missing. */
562 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
564 if (!gimple_has_body_p (callee->decl))
566 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
569 /* In early inliner some of callees may not be in SSA form yet
570 (i.e. the callgraph is cyclic and we did not process
571 the callee by early inliner, yet). We don't have CIF code for this
572 case; later we will re-do the decision in the real inliner. */
573 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
574 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
577 fprintf (dump_file, " edge not inlinable: not in SSA form\n");
580 if (!can_inline_edge_p (e, true, true)
581 || !can_inline_edge_by_limits_p (e, true, false, true))
587 /* Return number of calls in N. Ignore cheap builtins. */
590 num_calls (struct cgraph_node *n)
592 struct cgraph_edge *e;
595 for (e = n->callees; e; e = e->next_callee)
596 if (!is_inexpensive_builtin (e->callee->decl))
602 /* Return true if we are interested in inlining small function. */
605 want_early_inline_function_p (struct cgraph_edge *e)
607 bool want_inline = true;
608 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
610 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
612 /* For AutoFDO, we need to make sure that before profile summary, all
613 hot paths' IR look exactly the same as profiled binary. As a result,
614 in einliner, we will disregard size limit and inline those callsites
616 * inlined in the profiled binary, and
617 * the cloned callee has enough samples to be considered "hot". */
618 else if (flag_auto_profile && afdo_callsite_hot_enough_for_early_inline (e))
620 else if (!DECL_DECLARED_INLINE_P (callee->decl)
621 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
623 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
624 report_inline_failed_reason (e);
629 int growth = estimate_edge_growth (e);
634 else if (!e->maybe_hot_p ()
638 fprintf (dump_file, " will not early inline: %s->%s, "
639 "call is cold and code would grow by %i\n",
640 e->caller->dump_name (),
641 callee->dump_name (),
645 else if (growth > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS))
648 fprintf (dump_file, " will not early inline: %s->%s, "
649 "growth %i exceeds --param early-inlining-insns\n",
650 e->caller->dump_name (),
651 callee->dump_name (),
655 else if ((n = num_calls (callee)) != 0
656 && growth * (n + 1) > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS))
659 fprintf (dump_file, " will not early inline: %s->%s, "
660 "growth %i exceeds --param early-inlining-insns "
661 "divided by number of calls\n",
662 e->caller->dump_name (),
663 callee->dump_name (),
671 /* Compute time of the edge->caller + edge->callee execution when inlining
675 compute_uninlined_call_time (struct cgraph_edge *edge,
676 sreal uninlined_call_time)
678 cgraph_node *caller = (edge->caller->global.inlined_to
679 ? edge->caller->global.inlined_to
682 sreal freq = edge->sreal_frequency ();
684 uninlined_call_time *= freq;
686 uninlined_call_time = uninlined_call_time >> 11;
688 sreal caller_time = ipa_fn_summaries->get (caller)->time;
689 return uninlined_call_time + caller_time;
692 /* Same as compute_uinlined_call_time but compute time when inlining
696 compute_inlined_call_time (struct cgraph_edge *edge,
699 cgraph_node *caller = (edge->caller->global.inlined_to
700 ? edge->caller->global.inlined_to
702 sreal caller_time = ipa_fn_summaries->get (caller)->time;
704 sreal freq = edge->sreal_frequency ();
710 /* This calculation should match one in ipa-inline-analysis.c
711 (estimate_edge_size_and_time). */
712 time -= (sreal)ipa_call_summaries->get (edge)->call_stmt_time * freq;
715 time = ((sreal) 1) >> 8;
716 gcc_checking_assert (time >= 0);
720 /* Return true if the speedup for inlining E is bigger than
721 PARAM_MAX_INLINE_MIN_SPEEDUP. */
724 big_speedup_p (struct cgraph_edge *e)
727 sreal spec_time = estimate_edge_time (e, &unspec_time);
728 sreal time = compute_uninlined_call_time (e, unspec_time);
729 sreal inlined_time = compute_inlined_call_time (e, spec_time);
731 if ((time - inlined_time) * 100
732 > (sreal) (time * PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP)))
737 /* Return true if we are interested in inlining small function.
738 When REPORT is true, report reason to dump file. */
741 want_inline_small_function_p (struct cgraph_edge *e, bool report)
743 bool want_inline = true;
744 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
746 /* Allow this function to be called before can_inline_edge_p,
747 since it's usually cheaper. */
748 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
750 else if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
752 else if (!DECL_DECLARED_INLINE_P (callee->decl)
753 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
755 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
758 /* Do fast and conservative check if the function can be good
759 inline candidate. At the moment we allow inline hints to
760 promote non-inline functions to inline and we increase
761 MAX_INLINE_INSNS_SINGLE 16-fold for inline functions. */
762 else if ((!DECL_DECLARED_INLINE_P (callee->decl)
763 && (!e->count.ipa ().initialized_p () || !e->maybe_hot_p ()))
764 && ipa_fn_summaries->get (callee)->min_size
765 - ipa_call_summaries->get (e)->call_stmt_size
766 > MAX (MAX_INLINE_INSNS_SINGLE, MAX_INLINE_INSNS_AUTO))
768 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
771 else if ((DECL_DECLARED_INLINE_P (callee->decl)
772 || e->count.ipa ().nonzero_p ())
773 && ipa_fn_summaries->get (callee)->min_size
774 - ipa_call_summaries->get (e)->call_stmt_size
775 > 16 * MAX_INLINE_INSNS_SINGLE)
777 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
778 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
779 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT);
784 int growth = estimate_edge_growth (e);
785 ipa_hints hints = estimate_edge_hints (e);
786 bool big_speedup = big_speedup_p (e);
790 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when
791 hints suggests that inlining given function is very profitable. */
792 else if (DECL_DECLARED_INLINE_P (callee->decl)
793 && growth >= MAX_INLINE_INSNS_SINGLE
795 && !(hints & (INLINE_HINT_indirect_call
796 | INLINE_HINT_known_hot
797 | INLINE_HINT_loop_iterations
798 | INLINE_HINT_array_index
799 | INLINE_HINT_loop_stride)))
800 || growth >= MAX_INLINE_INSNS_SINGLE * 16))
802 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
805 else if (!DECL_DECLARED_INLINE_P (callee->decl)
806 && !opt_for_fn (e->caller->decl, flag_inline_functions))
808 /* growth_likely_positive is expensive, always test it last. */
809 if (growth >= MAX_INLINE_INSNS_SINGLE
810 || growth_likely_positive (callee, growth))
812 e->inline_failed = CIF_NOT_DECLARED_INLINED;
816 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline
817 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that
818 inlining given function is very profitable. */
819 else if (!DECL_DECLARED_INLINE_P (callee->decl)
821 && !(hints & INLINE_HINT_known_hot)
822 && growth >= ((hints & (INLINE_HINT_indirect_call
823 | INLINE_HINT_loop_iterations
824 | INLINE_HINT_array_index
825 | INLINE_HINT_loop_stride))
826 ? MAX (MAX_INLINE_INSNS_AUTO,
827 MAX_INLINE_INSNS_SINGLE)
828 : MAX_INLINE_INSNS_AUTO))
830 /* growth_likely_positive is expensive, always test it last. */
831 if (growth >= MAX_INLINE_INSNS_SINGLE
832 || growth_likely_positive (callee, growth))
834 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
838 /* If call is cold, do not inline when function body would grow. */
839 else if (!e->maybe_hot_p ()
840 && (growth >= MAX_INLINE_INSNS_SINGLE
841 || growth_likely_positive (callee, growth)))
843 e->inline_failed = CIF_UNLIKELY_CALL;
847 if (!want_inline && report)
848 report_inline_failed_reason (e);
852 /* EDGE is self recursive edge.
853 We hand two cases - when function A is inlining into itself
854 or when function A is being inlined into another inliner copy of function
857 In first case OUTER_NODE points to the toplevel copy of A, while
858 in the second case OUTER_NODE points to the outermost copy of A in B.
860 In both cases we want to be extra selective since
861 inlining the call will just introduce new recursive calls to appear. */
864 want_inline_self_recursive_call_p (struct cgraph_edge *edge,
865 struct cgraph_node *outer_node,
869 char const *reason = NULL;
870 bool want_inline = true;
871 sreal caller_freq = 1;
872 int max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO);
874 if (DECL_DECLARED_INLINE_P (edge->caller->decl))
875 max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH);
877 if (!edge->maybe_hot_p ())
879 reason = "recursive call is cold";
882 else if (depth > max_depth)
884 reason = "--param max-inline-recursive-depth exceeded.";
887 else if (outer_node->global.inlined_to
888 && (caller_freq = outer_node->callers->sreal_frequency ()) == 0)
890 reason = "caller frequency is 0";
896 /* Inlining of self recursive function into copy of itself within other
897 function is transformation similar to loop peeling.
899 Peeling is profitable if we can inline enough copies to make probability
900 of actual call to the self recursive function very small. Be sure that
901 the probability of recursion is small.
903 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
904 This way the expected number of recursion is at most max_depth. */
907 sreal max_prob = (sreal)1 - ((sreal)1 / (sreal)max_depth);
909 for (i = 1; i < depth; i++)
910 max_prob = max_prob * max_prob;
911 if (edge->sreal_frequency () >= max_prob * caller_freq)
913 reason = "frequency of recursive call is too large";
917 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if
918 recursion depth is large. We reduce function call overhead and increase
919 chances that things fit in hardware return predictor.
921 Recursive inlining might however increase cost of stack frame setup
922 actually slowing down functions whose recursion tree is wide rather than
925 Deciding reliably on when to do recursive inlining without profile feedback
926 is tricky. For now we disable recursive inlining when probability of self
929 Recursive inlining of self recursive call within loop also results in
930 large loop depths that generally optimize badly. We may want to throttle
931 down inlining in those cases. In particular this seems to happen in one
932 of libstdc++ rb tree methods. */
935 if (edge->sreal_frequency () * 100
937 * PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY))
939 reason = "frequency of recursive call is too small";
943 if (!want_inline && dump_file)
944 fprintf (dump_file, " not inlining recursively: %s\n", reason);
948 /* Return true when NODE has uninlinable caller;
949 set HAS_HOT_CALL if it has hot call.
950 Worker for cgraph_for_node_and_aliases. */
953 check_callers (struct cgraph_node *node, void *has_hot_call)
955 struct cgraph_edge *e;
956 for (e = node->callers; e; e = e->next_caller)
958 if (!opt_for_fn (e->caller->decl, flag_inline_functions_called_once)
959 || !opt_for_fn (e->caller->decl, optimize))
961 if (!can_inline_edge_p (e, true))
963 if (e->recursive_p ())
965 if (!can_inline_edge_by_limits_p (e, true))
967 if (!(*(bool *)has_hot_call) && e->maybe_hot_p ())
968 *(bool *)has_hot_call = true;
973 /* If NODE has a caller, return true. */
976 has_caller_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
983 /* Decide if inlining NODE would reduce unit size by eliminating
984 the offline copy of function.
985 When COLD is true the cold calls are considered, too. */
988 want_inline_function_to_all_callers_p (struct cgraph_node *node, bool cold)
990 bool has_hot_call = false;
992 /* Aliases gets inlined along with the function they alias. */
995 /* Already inlined? */
996 if (node->global.inlined_to)
998 /* Does it have callers? */
999 if (!node->call_for_symbol_and_aliases (has_caller_p, NULL, true))
1001 /* Inlining into all callers would increase size? */
1002 if (estimate_growth (node) > 0)
1004 /* All inlines must be possible. */
1005 if (node->call_for_symbol_and_aliases (check_callers, &has_hot_call,
1008 if (!cold && !has_hot_call)
1013 /* A cost model driving the inlining heuristics in a way so the edges with
1014 smallest badness are inlined first. After each inlining is performed
1015 the costs of all caller edges of nodes affected are recomputed so the
1016 metrics may accurately depend on values such as number of inlinable callers
1017 of the function or function body size. */
1020 edge_badness (struct cgraph_edge *edge, bool dump)
1024 sreal edge_time, unspec_edge_time;
1025 struct cgraph_node *callee = edge->callee->ultimate_alias_target ();
1026 struct ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
1028 cgraph_node *caller = (edge->caller->global.inlined_to
1029 ? edge->caller->global.inlined_to
1032 growth = estimate_edge_growth (edge);
1033 edge_time = estimate_edge_time (edge, &unspec_edge_time);
1034 hints = estimate_edge_hints (edge);
1035 gcc_checking_assert (edge_time >= 0);
1036 /* Check that inlined time is better, but tolerate some roundoff issues.
1037 FIXME: When callee profile drops to 0 we account calls more. This
1038 should be fixed by never doing that. */
1039 gcc_checking_assert ((edge_time * 100
1040 - callee_info->time * 101).to_int () <= 0
1041 || callee->count.ipa ().initialized_p ());
1042 gcc_checking_assert (growth <= callee_info->size);
1046 fprintf (dump_file, " Badness calculation for %s -> %s\n",
1047 edge->caller->dump_name (),
1048 edge->callee->dump_name ());
1049 fprintf (dump_file, " size growth %i, time %f unspec %f ",
1051 edge_time.to_double (),
1052 unspec_edge_time.to_double ());
1053 ipa_dump_hints (dump_file, hints);
1054 if (big_speedup_p (edge))
1055 fprintf (dump_file, " big_speedup");
1056 fprintf (dump_file, "\n");
1059 /* Always prefer inlining saving code size. */
1062 badness = (sreal) (-SREAL_MIN_SIG + growth) << (SREAL_MAX_EXP / 256);
1064 fprintf (dump_file, " %f: Growth %d <= 0\n", badness.to_double (),
1067 /* Inlining into EXTERNAL functions is not going to change anything unless
1068 they are themselves inlined. */
1069 else if (DECL_EXTERNAL (caller->decl))
1072 fprintf (dump_file, " max: function is external\n");
1073 return sreal::max ();
1075 /* When profile is available. Compute badness as:
1077 time_saved * caller_count
1078 goodness = -------------------------------------------------
1079 growth_of_caller * overall_growth * combined_size
1081 badness = - goodness
1083 Again use negative value to make calls with profile appear hotter
1086 else if (opt_for_fn (caller->decl, flag_guess_branch_prob)
1087 || caller->count.ipa ().nonzero_p ())
1089 sreal numerator, denominator;
1091 sreal inlined_time = compute_inlined_call_time (edge, edge_time);
1093 numerator = (compute_uninlined_call_time (edge, unspec_edge_time)
1096 numerator = ((sreal) 1 >> 8);
1097 if (caller->count.ipa ().nonzero_p ())
1098 numerator *= caller->count.ipa ().to_gcov_type ();
1099 else if (caller->count.ipa ().initialized_p ())
1100 numerator = numerator >> 11;
1101 denominator = growth;
1103 overall_growth = callee_info->growth;
1105 /* Look for inliner wrappers of the form:
1111 noninline_callee ();
1113 Withhout panilizing this case, we usually inline noninline_callee
1114 into the inline_caller because overall_growth is small preventing
1115 further inlining of inline_caller.
1117 Penalize only callgraph edges to functions with small overall
1120 if (growth > overall_growth
1121 /* ... and having only one caller which is not inlined ... */
1122 && callee_info->single_caller
1123 && !edge->caller->global.inlined_to
1124 /* ... and edges executed only conditionally ... */
1125 && edge->sreal_frequency () < 1
1126 /* ... consider case where callee is not inline but caller is ... */
1127 && ((!DECL_DECLARED_INLINE_P (edge->callee->decl)
1128 && DECL_DECLARED_INLINE_P (caller->decl))
1129 /* ... or when early optimizers decided to split and edge
1130 frequency still indicates splitting is a win ... */
1131 || (callee->split_part && !caller->split_part
1132 && edge->sreal_frequency () * 100
1134 (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY)
1135 /* ... and do not overwrite user specified hints. */
1136 && (!DECL_DECLARED_INLINE_P (edge->callee->decl)
1137 || DECL_DECLARED_INLINE_P (caller->decl)))))
1139 struct ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
1140 int caller_growth = caller_info->growth;
1142 /* Only apply the penalty when caller looks like inline candidate,
1143 and it is not called once and. */
1144 if (!caller_info->single_caller && overall_growth < caller_growth
1145 && caller_info->inlinable
1146 && caller_info->size
1147 < (DECL_DECLARED_INLINE_P (caller->decl)
1148 ? MAX_INLINE_INSNS_SINGLE : MAX_INLINE_INSNS_AUTO))
1152 " Wrapper penalty. Increasing growth %i to %i\n",
1153 overall_growth, caller_growth);
1154 overall_growth = caller_growth;
1157 if (overall_growth > 0)
1159 /* Strongly preffer functions with few callers that can be inlined
1160 fully. The square root here leads to smaller binaries at average.
1161 Watch however for extreme cases and return to linear function
1162 when growth is large. */
1163 if (overall_growth < 256)
1164 overall_growth *= overall_growth;
1166 overall_growth += 256 * 256 - 256;
1167 denominator *= overall_growth;
1169 denominator *= ipa_fn_summaries->get (caller)->self_size + growth;
1171 badness = - numerator / denominator;
1176 " %f: guessed profile. frequency %f, count %" PRId64
1177 " caller count %" PRId64
1178 " time w/o inlining %f, time with inlining %f"
1179 " overall growth %i (current) %i (original)"
1180 " %i (compensated)\n",
1181 badness.to_double (),
1182 edge->sreal_frequency ().to_double (),
1183 edge->count.ipa ().initialized_p () ? edge->count.ipa ().to_gcov_type () : -1,
1184 caller->count.ipa ().initialized_p () ? caller->count.ipa ().to_gcov_type () : -1,
1185 compute_uninlined_call_time (edge,
1186 unspec_edge_time).to_double (),
1187 inlined_time.to_double (),
1188 estimate_growth (callee),
1189 callee_info->growth, overall_growth);
1192 /* When function local profile is not available or it does not give
1193 useful information (ie frequency is zero), base the cost on
1194 loop nest and overall size growth, so we optimize for overall number
1195 of functions fully inlined in program. */
1198 int nest = MIN (ipa_call_summaries->get (edge)->loop_depth, 8);
1201 /* Decrease badness if call is nested. */
1203 badness = badness >> nest;
1205 badness = badness << nest;
1207 fprintf (dump_file, " %f: no profile. nest %i\n",
1208 badness.to_double (), nest);
1210 gcc_checking_assert (badness != 0);
1212 if (edge->recursive_p ())
1213 badness = badness.shift (badness > 0 ? 4 : -4);
1214 if ((hints & (INLINE_HINT_indirect_call
1215 | INLINE_HINT_loop_iterations
1216 | INLINE_HINT_array_index
1217 | INLINE_HINT_loop_stride))
1218 || callee_info->growth <= 0)
1219 badness = badness.shift (badness > 0 ? -2 : 2);
1220 if (hints & (INLINE_HINT_same_scc))
1221 badness = badness.shift (badness > 0 ? 3 : -3);
1222 else if (hints & (INLINE_HINT_in_scc))
1223 badness = badness.shift (badness > 0 ? 2 : -2);
1224 else if (hints & (INLINE_HINT_cross_module))
1225 badness = badness.shift (badness > 0 ? 1 : -1);
1226 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
1227 badness = badness.shift (badness > 0 ? -4 : 4);
1228 else if ((hints & INLINE_HINT_declared_inline))
1229 badness = badness.shift (badness > 0 ? -3 : 3);
1231 fprintf (dump_file, " Adjusted by hints %f\n", badness.to_double ());
1235 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1237 update_edge_key (edge_heap_t *heap, struct cgraph_edge *edge)
1239 sreal badness = edge_badness (edge, false);
1242 edge_heap_node_t *n = (edge_heap_node_t *) edge->aux;
1243 gcc_checking_assert (n->get_data () == edge);
1245 /* fibonacci_heap::replace_key does busy updating of the
1246 heap that is unnecesarily expensive.
1247 We do lazy increases: after extracting minimum if the key
1248 turns out to be out of date, it is re-inserted into heap
1249 with correct value. */
1250 if (badness < n->get_key ())
1252 if (dump_file && (dump_flags & TDF_DETAILS))
1255 " decreasing badness %s -> %s, %f to %f\n",
1256 edge->caller->dump_name (),
1257 edge->callee->dump_name (),
1258 n->get_key ().to_double (),
1259 badness.to_double ());
1261 heap->decrease_key (n, badness);
1266 if (dump_file && (dump_flags & TDF_DETAILS))
1269 " enqueuing call %s -> %s, badness %f\n",
1270 edge->caller->dump_name (),
1271 edge->callee->dump_name (),
1272 badness.to_double ());
1274 edge->aux = heap->insert (badness, edge);
1279 /* NODE was inlined.
1280 All caller edges needs to be resetted because
1281 size estimates change. Similarly callees needs reset
1282 because better context may be known. */
1285 reset_edge_caches (struct cgraph_node *node)
1287 struct cgraph_edge *edge;
1288 struct cgraph_edge *e = node->callees;
1289 struct cgraph_node *where = node;
1290 struct ipa_ref *ref;
1292 if (where->global.inlined_to)
1293 where = where->global.inlined_to;
1295 for (edge = where->callers; edge; edge = edge->next_caller)
1296 if (edge->inline_failed)
1297 reset_edge_growth_cache (edge);
1299 FOR_EACH_ALIAS (where, ref)
1300 reset_edge_caches (dyn_cast <cgraph_node *> (ref->referring));
1306 if (!e->inline_failed && e->callee->callees)
1307 e = e->callee->callees;
1310 if (e->inline_failed)
1311 reset_edge_growth_cache (e);
1318 if (e->caller == node)
1320 e = e->caller->callers;
1322 while (!e->next_callee);
1328 /* Recompute HEAP nodes for each of caller of NODE.
1329 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1330 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1331 it is inlinable. Otherwise check all edges. */
1334 update_caller_keys (edge_heap_t *heap, struct cgraph_node *node,
1335 bitmap updated_nodes,
1336 struct cgraph_edge *check_inlinablity_for)
1338 struct cgraph_edge *edge;
1339 struct ipa_ref *ref;
1341 if ((!node->alias && !ipa_fn_summaries->get (node)->inlinable)
1342 || node->global.inlined_to)
1344 if (!bitmap_set_bit (updated_nodes, node->uid))
1347 FOR_EACH_ALIAS (node, ref)
1349 struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
1350 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for);
1353 for (edge = node->callers; edge; edge = edge->next_caller)
1354 if (edge->inline_failed)
1356 if (!check_inlinablity_for
1357 || check_inlinablity_for == edge)
1359 if (can_inline_edge_p (edge, false)
1360 && want_inline_small_function_p (edge, false)
1361 && can_inline_edge_by_limits_p (edge, false))
1362 update_edge_key (heap, edge);
1365 report_inline_failed_reason (edge);
1366 heap->delete_node ((edge_heap_node_t *) edge->aux);
1371 update_edge_key (heap, edge);
1375 /* Recompute HEAP nodes for each uninlined call in NODE.
1376 This is used when we know that edge badnesses are going only to increase
1377 (we introduced new call site) and thus all we need is to insert newly
1378 created edges into heap. */
1381 update_callee_keys (edge_heap_t *heap, struct cgraph_node *node,
1382 bitmap updated_nodes)
1384 struct cgraph_edge *e = node->callees;
1389 if (!e->inline_failed && e->callee->callees)
1390 e = e->callee->callees;
1393 enum availability avail;
1394 struct cgraph_node *callee;
1395 /* We do not reset callee growth cache here. Since we added a new call,
1396 growth chould have just increased and consequentely badness metric
1397 don't need updating. */
1398 if (e->inline_failed
1399 && (callee = e->callee->ultimate_alias_target (&avail, e->caller))
1400 && ipa_fn_summaries->get (callee)->inlinable
1401 && avail >= AVAIL_AVAILABLE
1402 && !bitmap_bit_p (updated_nodes, callee->uid))
1404 if (can_inline_edge_p (e, false)
1405 && want_inline_small_function_p (e, false)
1406 && can_inline_edge_by_limits_p (e, false))
1407 update_edge_key (heap, e);
1410 report_inline_failed_reason (e);
1411 heap->delete_node ((edge_heap_node_t *) e->aux);
1421 if (e->caller == node)
1423 e = e->caller->callers;
1425 while (!e->next_callee);
1431 /* Enqueue all recursive calls from NODE into priority queue depending on
1432 how likely we want to recursively inline the call. */
1435 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
1438 struct cgraph_edge *e;
1439 enum availability avail;
1441 for (e = where->callees; e; e = e->next_callee)
1442 if (e->callee == node
1443 || (e->callee->ultimate_alias_target (&avail, e->caller) == node
1444 && avail > AVAIL_INTERPOSABLE))
1445 heap->insert (-e->sreal_frequency (), e);
1446 for (e = where->callees; e; e = e->next_callee)
1447 if (!e->inline_failed)
1448 lookup_recursive_calls (node, e->callee, heap);
1451 /* Decide on recursive inlining: in the case function has recursive calls,
1452 inline until body size reaches given argument. If any new indirect edges
1453 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1457 recursive_inlining (struct cgraph_edge *edge,
1458 vec<cgraph_edge *> *new_edges)
1460 int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO);
1461 edge_heap_t heap (sreal::min ());
1462 struct cgraph_node *node;
1463 struct cgraph_edge *e;
1464 struct cgraph_node *master_clone = NULL, *next;
1468 node = edge->caller;
1469 if (node->global.inlined_to)
1470 node = node->global.inlined_to;
1472 if (DECL_DECLARED_INLINE_P (node->decl))
1473 limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE);
1475 /* Make sure that function is small enough to be considered for inlining. */
1476 if (estimate_size_after_inlining (node, edge) >= limit)
1478 lookup_recursive_calls (node, node, &heap);
1484 " Performing recursive inlining on %s\n",
1487 /* Do the inlining and update list of recursive call during process. */
1488 while (!heap.empty ())
1490 struct cgraph_edge *curr = heap.extract_min ();
1491 struct cgraph_node *cnode, *dest = curr->callee;
1493 if (!can_inline_edge_p (curr, true)
1494 || can_inline_edge_by_limits_p (curr, true))
1497 /* MASTER_CLONE is produced in the case we already started modified
1498 the function. Be sure to redirect edge to the original body before
1499 estimating growths otherwise we will be seeing growths after inlining
1500 the already modified body. */
1503 curr->redirect_callee (master_clone);
1504 reset_edge_growth_cache (curr);
1507 if (estimate_size_after_inlining (node, curr) > limit)
1509 curr->redirect_callee (dest);
1510 reset_edge_growth_cache (curr);
1515 for (cnode = curr->caller;
1516 cnode->global.inlined_to; cnode = cnode->callers->caller)
1518 == curr->callee->ultimate_alias_target ()->decl)
1521 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1523 curr->redirect_callee (dest);
1524 reset_edge_growth_cache (curr);
1531 " Inlining call of depth %i", depth);
1532 if (node->count.nonzero_p ())
1534 fprintf (dump_file, " called approx. %.2f times per call",
1535 (double)curr->count.to_gcov_type ()
1536 / node->count.to_gcov_type ());
1538 fprintf (dump_file, "\n");
1542 /* We need original clone to copy around. */
1543 master_clone = node->create_clone (node->decl, node->count,
1544 false, vNULL, true, NULL, NULL);
1545 for (e = master_clone->callees; e; e = e->next_callee)
1546 if (!e->inline_failed)
1547 clone_inlined_nodes (e, true, false, NULL);
1548 curr->redirect_callee (master_clone);
1549 reset_edge_growth_cache (curr);
1552 inline_call (curr, false, new_edges, &overall_size, true);
1553 lookup_recursive_calls (node, curr->callee, &heap);
1557 if (!heap.empty () && dump_file)
1558 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1565 "\n Inlined %i times, "
1566 "body grown from size %i to %i, time %f to %f\n", n,
1567 ipa_fn_summaries->get (master_clone)->size,
1568 ipa_fn_summaries->get (node)->size,
1569 ipa_fn_summaries->get (master_clone)->time.to_double (),
1570 ipa_fn_summaries->get (node)->time.to_double ());
1572 /* Remove master clone we used for inlining. We rely that clones inlined
1573 into master clone gets queued just before master clone so we don't
1575 for (node = symtab->first_function (); node != master_clone;
1578 next = symtab->next_function (node);
1579 if (node->global.inlined_to == master_clone)
1582 master_clone->remove ();
1587 /* Given whole compilation unit estimate of INSNS, compute how large we can
1588 allow the unit to grow. */
1591 compute_max_insns (int insns)
1593 int max_insns = insns;
1594 if (max_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS))
1595 max_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS);
1597 return ((int64_t) max_insns
1598 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100);
1602 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1605 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> new_edges)
1607 while (new_edges.length () > 0)
1609 struct cgraph_edge *edge = new_edges.pop ();
1611 gcc_assert (!edge->aux);
1612 if (edge->inline_failed
1613 && can_inline_edge_p (edge, true)
1614 && want_inline_small_function_p (edge, true)
1615 && can_inline_edge_by_limits_p (edge, true))
1616 edge->aux = heap->insert (edge_badness (edge, false), edge);
1620 /* Remove EDGE from the fibheap. */
1623 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1627 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux);
1632 /* Return true if speculation of edge E seems useful.
1633 If ANTICIPATE_INLINING is true, be conservative and hope that E
1637 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1639 enum availability avail;
1640 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail,
1642 struct cgraph_edge *direct, *indirect;
1643 struct ipa_ref *ref;
1645 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1647 if (!e->maybe_hot_p ())
1650 /* See if IP optimizations found something potentially useful about the
1651 function. For now we look only for CONST/PURE flags. Almost everything
1652 else we propagate is useless. */
1653 if (avail >= AVAIL_AVAILABLE)
1655 int ecf_flags = flags_from_decl_or_type (target->decl);
1656 if (ecf_flags & ECF_CONST)
1658 e->speculative_call_info (direct, indirect, ref);
1659 if (!(indirect->indirect_info->ecf_flags & ECF_CONST))
1662 else if (ecf_flags & ECF_PURE)
1664 e->speculative_call_info (direct, indirect, ref);
1665 if (!(indirect->indirect_info->ecf_flags & ECF_PURE))
1669 /* If we did not managed to inline the function nor redirect
1670 to an ipa-cp clone (that are seen by having local flag set),
1671 it is probably pointless to inline it unless hardware is missing
1672 indirect call predictor. */
1673 if (!anticipate_inlining && e->inline_failed && !target->local.local)
1675 /* For overwritable targets there is not much to do. */
1676 if (e->inline_failed
1677 && (!can_inline_edge_p (e, false)
1678 || !can_inline_edge_by_limits_p (e, false, true)))
1680 /* OK, speculation seems interesting. */
1684 /* We know that EDGE is not going to be inlined.
1685 See if we can remove speculation. */
1688 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge)
1690 if (edge->speculative && !speculation_useful_p (edge, false))
1692 struct cgraph_node *node = edge->caller;
1693 struct cgraph_node *where = node->global.inlined_to
1694 ? node->global.inlined_to : node;
1695 auto_bitmap updated_nodes;
1697 if (edge->count.ipa ().initialized_p ())
1698 spec_rem += edge->count.ipa ();
1699 edge->resolve_speculation ();
1700 reset_edge_caches (where);
1701 ipa_update_overall_fn_summary (where);
1702 update_caller_keys (edge_heap, where,
1703 updated_nodes, NULL);
1704 update_callee_keys (edge_heap, where,
1709 /* Return true if NODE should be accounted for overall size estimate.
1710 Skip all nodes optimized for size so we can measure the growth of hot
1711 part of program no matter of the padding. */
1714 inline_account_function_p (struct cgraph_node *node)
1716 return (!DECL_EXTERNAL (node->decl)
1717 && !opt_for_fn (node->decl, optimize_size)
1718 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
1721 /* Count number of callers of NODE and store it into DATA (that
1722 points to int. Worker for cgraph_for_node_and_aliases. */
1725 sum_callers (struct cgraph_node *node, void *data)
1727 struct cgraph_edge *e;
1728 int *num_calls = (int *)data;
1730 for (e = node->callers; e; e = e->next_caller)
1735 /* We use greedy algorithm for inlining of small functions:
1736 All inline candidates are put into prioritized heap ordered in
1739 The inlining of small functions is bounded by unit growth parameters. */
1742 inline_small_functions (void)
1744 struct cgraph_node *node;
1745 struct cgraph_edge *edge;
1746 edge_heap_t edge_heap (sreal::min ());
1747 auto_bitmap updated_nodes;
1748 int min_size, max_size;
1749 auto_vec<cgraph_edge *> new_indirect_edges;
1750 int initial_size = 0;
1751 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count);
1752 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1753 new_indirect_edges.create (8);
1755 edge_removal_hook_holder
1756 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap);
1758 /* Compute overall unit size and other global parameters used by badness
1761 max_count = profile_count::uninitialized ();
1762 ipa_reduced_postorder (order, true, NULL);
1765 FOR_EACH_DEFINED_FUNCTION (node)
1766 if (!node->global.inlined_to)
1768 if (!node->alias && node->analyzed
1769 && (node->has_gimple_body_p () || node->thunk.thunk_p)
1770 && opt_for_fn (node->decl, optimize))
1772 struct ipa_fn_summary *info = ipa_fn_summaries->get (node);
1773 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux;
1775 /* Do not account external functions, they will be optimized out
1776 if not inlined. Also only count the non-cold portion of program. */
1777 if (inline_account_function_p (node))
1778 initial_size += info->size;
1779 info->growth = estimate_growth (node);
1782 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
1785 info->single_caller = true;
1786 if (dfs && dfs->next_cycle)
1788 struct cgraph_node *n2;
1789 int id = dfs->scc_no + 1;
1791 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle)
1792 if (opt_for_fn (n2->decl, optimize))
1794 struct ipa_fn_summary *info2 = ipa_fn_summaries->get (n2);
1802 for (edge = node->callers; edge; edge = edge->next_caller)
1803 max_count = max_count.max (edge->count.ipa ());
1805 ipa_free_postorder_info ();
1806 initialize_growth_caches ();
1810 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1813 overall_size = initial_size;
1814 max_size = compute_max_insns (overall_size);
1815 min_size = overall_size;
1817 /* Populate the heap with all edges we might inline. */
1819 FOR_EACH_DEFINED_FUNCTION (node)
1821 bool update = false;
1822 struct cgraph_edge *next = NULL;
1823 bool has_speculative = false;
1825 if (!opt_for_fn (node->decl, optimize))
1829 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ());
1831 for (edge = node->callees; edge; edge = next)
1833 next = edge->next_callee;
1834 if (edge->inline_failed
1836 && can_inline_edge_p (edge, true)
1837 && want_inline_small_function_p (edge, true)
1838 && can_inline_edge_by_limits_p (edge, true)
1839 && edge->inline_failed)
1841 gcc_assert (!edge->aux);
1842 update_edge_key (&edge_heap, edge);
1844 if (edge->speculative)
1845 has_speculative = true;
1847 if (has_speculative)
1848 for (edge = node->callees; edge; edge = next)
1849 if (edge->speculative && !speculation_useful_p (edge,
1852 edge->resolve_speculation ();
1857 struct cgraph_node *where = node->global.inlined_to
1858 ? node->global.inlined_to : node;
1859 ipa_update_overall_fn_summary (where);
1860 reset_edge_caches (where);
1861 update_caller_keys (&edge_heap, where,
1862 updated_nodes, NULL);
1863 update_callee_keys (&edge_heap, where,
1865 bitmap_clear (updated_nodes);
1869 gcc_assert (in_lto_p
1871 || (profile_info && flag_branch_probabilities));
1873 while (!edge_heap.empty ())
1875 int old_size = overall_size;
1876 struct cgraph_node *where, *callee;
1877 sreal badness = edge_heap.min_key ();
1878 sreal current_badness;
1881 edge = edge_heap.extract_min ();
1882 gcc_assert (edge->aux);
1884 if (!edge->inline_failed || !edge->callee->analyzed)
1888 /* Be sure that caches are maintained consistent.
1889 This check is affected by scaling roundoff errors when compiling for
1890 IPA this we skip it in that case. */
1891 if (!edge->callee->count.ipa_p ()
1892 && (!max_count.initialized_p () || !max_count.nonzero_p ()))
1894 sreal cached_badness = edge_badness (edge, false);
1896 int old_size_est = estimate_edge_size (edge);
1897 sreal old_time_est = estimate_edge_time (edge);
1898 int old_hints_est = estimate_edge_hints (edge);
1900 reset_edge_growth_cache (edge);
1901 gcc_assert (old_size_est == estimate_edge_size (edge));
1902 gcc_assert (old_time_est == estimate_edge_time (edge));
1905 gcc_assert (old_hints_est == estimate_edge_hints (edge));
1907 fails with profile feedback because some hints depends on
1908 maybe_hot_edge_p predicate and because callee gets inlined to other
1909 calls, the edge may become cold.
1910 This ought to be fixed by computing relative probabilities
1911 for given invocation but that will be better done once whole
1912 code is converted to sreals. Disable for now and revert to "wrong"
1913 value so enable/disable checking paths agree. */
1914 edge_growth_cache[edge->uid].hints = old_hints_est + 1;
1916 /* When updating the edge costs, we only decrease badness in the keys.
1917 Increases of badness are handled lazilly; when we see key with out
1918 of date value on it, we re-insert it now. */
1919 current_badness = edge_badness (edge, false);
1920 gcc_assert (cached_badness == current_badness);
1921 gcc_assert (current_badness >= badness);
1924 current_badness = edge_badness (edge, false);
1926 current_badness = edge_badness (edge, false);
1928 if (current_badness != badness)
1930 if (edge_heap.min () && current_badness > edge_heap.min_key ())
1932 edge->aux = edge_heap.insert (current_badness, edge);
1936 badness = current_badness;
1939 if (!can_inline_edge_p (edge, true)
1940 || !can_inline_edge_by_limits_p (edge, true))
1942 resolve_noninline_speculation (&edge_heap, edge);
1946 callee = edge->callee->ultimate_alias_target ();
1947 growth = estimate_edge_growth (edge);
1951 "\nConsidering %s with %i size\n",
1952 callee->dump_name (),
1953 ipa_fn_summaries->get (callee)->size);
1955 " to be inlined into %s in %s:%i\n"
1956 " Estimated badness is %f, frequency %.2f.\n",
1957 edge->caller->dump_name (),
1959 && (LOCATION_LOCUS (gimple_location ((const gimple *)
1961 > BUILTINS_LOCATION)
1962 ? gimple_filename ((const gimple *) edge->call_stmt)
1965 ? gimple_lineno ((const gimple *) edge->call_stmt)
1967 badness.to_double (),
1968 edge->sreal_frequency ().to_double ());
1969 if (edge->count.ipa ().initialized_p ())
1971 fprintf (dump_file, " Called ");
1972 edge->count.ipa ().dump (dump_file);
1973 fprintf (dump_file, " times\n");
1975 if (dump_flags & TDF_DETAILS)
1976 edge_badness (edge, true);
1979 if (overall_size + growth > max_size
1980 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl))
1982 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
1983 report_inline_failed_reason (edge);
1984 resolve_noninline_speculation (&edge_heap, edge);
1988 if (!want_inline_small_function_p (edge, true))
1990 resolve_noninline_speculation (&edge_heap, edge);
1994 /* Heuristics for inlining small functions work poorly for
1995 recursive calls where we do effects similar to loop unrolling.
1996 When inlining such edge seems profitable, leave decision on
1997 specific inliner. */
1998 if (edge->recursive_p ())
2000 where = edge->caller;
2001 if (where->global.inlined_to)
2002 where = where->global.inlined_to;
2003 if (!recursive_inlining (edge,
2004 opt_for_fn (edge->caller->decl,
2005 flag_indirect_inlining)
2006 ? &new_indirect_edges : NULL))
2008 edge->inline_failed = CIF_RECURSIVE_INLINING;
2009 resolve_noninline_speculation (&edge_heap, edge);
2012 reset_edge_caches (where);
2013 /* Recursive inliner inlines all recursive calls of the function
2014 at once. Consequently we need to update all callee keys. */
2015 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining))
2016 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2017 update_callee_keys (&edge_heap, where, updated_nodes);
2018 bitmap_clear (updated_nodes);
2022 struct cgraph_node *outer_node = NULL;
2025 /* Consider the case where self recursive function A is inlined
2026 into B. This is desired optimization in some cases, since it
2027 leads to effect similar of loop peeling and we might completely
2028 optimize out the recursive call. However we must be extra
2031 where = edge->caller;
2032 while (where->global.inlined_to)
2034 if (where->decl == callee->decl)
2035 outer_node = where, depth++;
2036 where = where->callers->caller;
2039 && !want_inline_self_recursive_call_p (edge, outer_node,
2043 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl)
2044 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
2045 resolve_noninline_speculation (&edge_heap, edge);
2048 else if (depth && dump_file)
2049 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
2051 gcc_checking_assert (!callee->global.inlined_to);
2052 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
2053 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2055 reset_edge_caches (edge->callee);
2057 update_callee_keys (&edge_heap, where, updated_nodes);
2059 where = edge->caller;
2060 if (where->global.inlined_to)
2061 where = where->global.inlined_to;
2063 /* Our profitability metric can depend on local properties
2064 such as number of inlinable calls and size of the function body.
2065 After inlining these properties might change for the function we
2066 inlined into (since it's body size changed) and for the functions
2067 called by function we inlined (since number of it inlinable callers
2069 update_caller_keys (&edge_heap, where, updated_nodes, NULL);
2070 /* Offline copy count has possibly changed, recompute if profile is
2072 struct cgraph_node *n = cgraph_node::get (edge->callee->decl);
2073 if (n != edge->callee && n->analyzed && n->count.ipa ().initialized_p ())
2074 update_callee_keys (&edge_heap, n, updated_nodes);
2075 bitmap_clear (updated_nodes);
2080 " Inlined %s into %s which now has time %f and size %i, "
2081 "net change of %+i.\n",
2082 xstrdup_for_dump (edge->callee->name ()),
2083 xstrdup_for_dump (edge->caller->name ()),
2084 ipa_fn_summaries->get (edge->caller)->time.to_double (),
2085 ipa_fn_summaries->get (edge->caller)->size,
2086 overall_size - old_size);
2088 if (min_size > overall_size)
2090 min_size = overall_size;
2091 max_size = compute_max_insns (min_size);
2094 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
2098 free_growth_caches ();
2101 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2102 initial_size, overall_size,
2103 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
2104 symtab->remove_edge_removal_hook (edge_removal_hook_holder);
2107 /* Flatten NODE. Performed both during early inlining and
2108 at IPA inlining time. */
2111 flatten_function (struct cgraph_node *node, bool early)
2113 struct cgraph_edge *e;
2115 /* We shouldn't be called recursively when we are being processed. */
2116 gcc_assert (node->aux == NULL);
2118 node->aux = (void *) node;
2120 for (e = node->callees; e; e = e->next_callee)
2122 struct cgraph_node *orig_callee;
2123 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2125 /* We've hit cycle? It is time to give up. */
2130 "Not inlining %s into %s to avoid cycle.\n",
2131 xstrdup_for_dump (callee->name ()),
2132 xstrdup_for_dump (e->caller->name ()));
2133 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR)
2134 e->inline_failed = CIF_RECURSIVE_INLINING;
2138 /* When the edge is already inlined, we just need to recurse into
2139 it in order to fully flatten the leaves. */
2140 if (!e->inline_failed)
2142 flatten_function (callee, early);
2146 /* Flatten attribute needs to be processed during late inlining. For
2147 extra code quality we however do flattening during early optimization,
2150 ? !can_inline_edge_p (e, true)
2151 && !can_inline_edge_by_limits_p (e, true)
2152 : !can_early_inline_edge_p (e))
2155 if (e->recursive_p ())
2158 fprintf (dump_file, "Not inlining: recursive call.\n");
2162 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
2163 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
2166 fprintf (dump_file, "Not inlining: SSA form does not match.\n");
2170 /* Inline the edge and flatten the inline clone. Avoid
2171 recursing through the original node if the node was cloned. */
2173 fprintf (dump_file, " Inlining %s into %s.\n",
2174 xstrdup_for_dump (callee->name ()),
2175 xstrdup_for_dump (e->caller->name ()));
2176 orig_callee = callee;
2177 inline_call (e, true, NULL, NULL, false);
2178 if (e->callee != orig_callee)
2179 orig_callee->aux = (void *) node;
2180 flatten_function (e->callee, early);
2181 if (e->callee != orig_callee)
2182 orig_callee->aux = NULL;
2186 if (!node->global.inlined_to)
2187 ipa_update_overall_fn_summary (node);
2190 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2191 DATA points to number of calls originally found so we avoid infinite
2195 inline_to_all_callers_1 (struct cgraph_node *node, void *data,
2196 hash_set<cgraph_node *> *callers)
2198 int *num_calls = (int *)data;
2199 bool callee_removed = false;
2201 while (node->callers && !node->global.inlined_to)
2203 struct cgraph_node *caller = node->callers->caller;
2205 if (!can_inline_edge_p (node->callers, true)
2206 || !can_inline_edge_by_limits_p (node->callers, true)
2207 || node->callers->recursive_p ())
2210 fprintf (dump_file, "Uninlinable call found; giving up.\n");
2218 "\nInlining %s size %i.\n",
2220 ipa_fn_summaries->get (node)->size);
2222 " Called once from %s %i insns.\n",
2223 node->callers->caller->name (),
2224 ipa_fn_summaries->get (node->callers->caller)->size);
2227 /* Remember which callers we inlined to, delaying updating the
2229 callers->add (node->callers->caller);
2230 inline_call (node->callers, true, NULL, NULL, false, &callee_removed);
2233 " Inlined into %s which now has %i size\n",
2235 ipa_fn_summaries->get (caller)->size);
2236 if (!(*num_calls)--)
2239 fprintf (dump_file, "New calls found; giving up.\n");
2240 return callee_removed;
2248 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2252 inline_to_all_callers (struct cgraph_node *node, void *data)
2254 hash_set<cgraph_node *> callers;
2255 bool res = inline_to_all_callers_1 (node, data, &callers);
2256 /* Perform the delayed update of the overall summary of all callers
2257 processed. This avoids quadratic behavior in the cases where
2258 we have a lot of calls to the same function. */
2259 for (hash_set<cgraph_node *>::iterator i = callers.begin ();
2260 i != callers.end (); ++i)
2261 ipa_update_overall_fn_summary (*i);
2265 /* Output overall time estimate. */
2267 dump_overall_stats (void)
2269 sreal sum_weighted = 0, sum = 0;
2270 struct cgraph_node *node;
2272 FOR_EACH_DEFINED_FUNCTION (node)
2273 if (!node->global.inlined_to
2276 sreal time = ipa_fn_summaries->get (node)->time;
2278 if (node->count.ipa ().initialized_p ())
2279 sum_weighted += time * node->count.ipa ().to_gcov_type ();
2281 fprintf (dump_file, "Overall time estimate: "
2282 "%f weighted by profile: "
2283 "%f\n", sum.to_double (), sum_weighted.to_double ());
2286 /* Output some useful stats about inlining. */
2289 dump_inline_stats (void)
2291 int64_t inlined_cnt = 0, inlined_indir_cnt = 0;
2292 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0;
2293 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0;
2294 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0;
2295 int64_t inlined_speculative = 0, inlined_speculative_ply = 0;
2296 int64_t indirect_poly_cnt = 0, indirect_cnt = 0;
2297 int64_t reason[CIF_N_REASONS][2];
2298 sreal reason_freq[CIF_N_REASONS];
2300 struct cgraph_node *node;
2302 memset (reason, 0, sizeof (reason));
2303 for (i=0; i < CIF_N_REASONS; i++)
2305 FOR_EACH_DEFINED_FUNCTION (node)
2307 struct cgraph_edge *e;
2308 for (e = node->callees; e; e = e->next_callee)
2310 if (e->inline_failed)
2312 if (e->count.ipa ().initialized_p ())
2313 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type ();
2314 reason_freq[(int) e->inline_failed] += e->sreal_frequency ();
2315 reason[(int) e->inline_failed][1] ++;
2316 if (DECL_VIRTUAL_P (e->callee->decl)
2317 && e->count.ipa ().initialized_p ())
2319 if (e->indirect_inlining_edge)
2320 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2322 noninlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2324 else if (e->count.ipa ().initialized_p ())
2326 if (e->indirect_inlining_edge)
2327 noninlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2329 noninlined_cnt += e->count.ipa ().to_gcov_type ();
2332 else if (e->count.ipa ().initialized_p ())
2336 if (DECL_VIRTUAL_P (e->callee->decl))
2337 inlined_speculative_ply += e->count.ipa ().to_gcov_type ();
2339 inlined_speculative += e->count.ipa ().to_gcov_type ();
2341 else if (DECL_VIRTUAL_P (e->callee->decl))
2343 if (e->indirect_inlining_edge)
2344 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2346 inlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2350 if (e->indirect_inlining_edge)
2351 inlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2353 inlined_cnt += e->count.ipa ().to_gcov_type ();
2357 for (e = node->indirect_calls; e; e = e->next_callee)
2358 if (e->indirect_info->polymorphic
2359 & e->count.ipa ().initialized_p ())
2360 indirect_poly_cnt += e->count.ipa ().to_gcov_type ();
2361 else if (e->count.ipa ().initialized_p ())
2362 indirect_cnt += e->count.ipa ().to_gcov_type ();
2364 if (max_count.initialized_p ())
2367 "Inlined %" PRId64 " + speculative "
2368 "%" PRId64 " + speculative polymorphic "
2369 "%" PRId64 " + previously indirect "
2370 "%" PRId64 " + virtual "
2371 "%" PRId64 " + virtual and previously indirect "
2372 "%" PRId64 "\n" "Not inlined "
2373 "%" PRId64 " + previously indirect "
2374 "%" PRId64 " + virtual "
2375 "%" PRId64 " + virtual and previously indirect "
2376 "%" PRId64 " + stil indirect "
2377 "%" PRId64 " + still indirect polymorphic "
2378 "%" PRId64 "\n", inlined_cnt,
2379 inlined_speculative, inlined_speculative_ply,
2380 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt,
2381 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt,
2382 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt);
2383 fprintf (dump_file, "Removed speculations ");
2384 spec_rem.dump (dump_file);
2385 fprintf (dump_file, "\n");
2387 dump_overall_stats ();
2388 fprintf (dump_file, "\nWhy inlining failed?\n");
2389 for (i = 0; i < CIF_N_REASONS; i++)
2391 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n",
2392 cgraph_inline_failed_string ((cgraph_inline_failed_t) i),
2393 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]);
2396 /* Called when node is removed. */
2399 flatten_remove_node_hook (struct cgraph_node *node, void *data)
2401 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL)
2404 hash_set<struct cgraph_node *> *removed
2405 = (hash_set<struct cgraph_node *> *) data;
2406 removed->add (node);
2409 /* Decide on the inlining. We do so in the topological order to avoid
2410 expenses on updating data structures. */
2415 struct cgraph_node *node;
2417 struct cgraph_node **order;
2420 bool remove_functions = false;
2422 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
2425 ipa_dump_fn_summaries (dump_file);
2427 nnodes = ipa_reverse_postorder (order);
2428 spec_rem = profile_count::zero ();
2430 FOR_EACH_FUNCTION (node)
2434 /* Recompute the default reasons for inlining because they may have
2435 changed during merging. */
2438 for (cgraph_edge *e = node->callees; e; e = e->next_callee)
2440 gcc_assert (e->inline_failed);
2441 initialize_inline_failed (e);
2443 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
2444 initialize_inline_failed (e);
2449 fprintf (dump_file, "\nFlattening functions:\n");
2451 /* First shrink order array, so that it only contains nodes with
2452 flatten attribute. */
2453 for (i = nnodes - 1, j = i; i >= 0; i--)
2456 if (lookup_attribute ("flatten",
2457 DECL_ATTRIBUTES (node->decl)) != NULL)
2458 order[j--] = order[i];
2461 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain
2462 nodes with flatten attribute. If there is more than one such
2463 node, we need to register a node removal hook, as flatten_function
2464 could remove other nodes with flatten attribute. See PR82801. */
2465 struct cgraph_node_hook_list *node_removal_hook_holder = NULL;
2466 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL;
2469 flatten_removed_nodes = new hash_set<struct cgraph_node *>;
2470 node_removal_hook_holder
2471 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook,
2472 flatten_removed_nodes);
2475 /* In the first pass handle functions to be flattened. Do this with
2476 a priority so none of our later choices will make this impossible. */
2477 for (i = nnodes - 1; i > j; i--)
2480 if (flatten_removed_nodes
2481 && flatten_removed_nodes->contains (node))
2484 /* Handle nodes to be flattened.
2485 Ideally when processing callees we stop inlining at the
2486 entry of cycles, possibly cloning that entry point and
2487 try to flatten itself turning it into a self-recursive
2490 fprintf (dump_file, "Flattening %s\n", node->name ());
2491 flatten_function (node, false);
2496 symtab->remove_cgraph_removal_hook (node_removal_hook_holder);
2497 delete flatten_removed_nodes;
2502 dump_overall_stats ();
2504 inline_small_functions ();
2506 gcc_assert (symtab->state == IPA_SSA);
2507 symtab->state = IPA_SSA_AFTER_INLINING;
2508 /* Do first after-inlining removal. We want to remove all "stale" extern
2509 inline functions and virtual functions so we really know what is called
2511 symtab->remove_unreachable_nodes (dump_file);
2513 /* Inline functions with a property that after inlining into all callers the
2514 code size will shrink because the out-of-line copy is eliminated.
2515 We do this regardless on the callee size as long as function growth limits
2519 "\nDeciding on functions to be inlined into all callers and "
2520 "removing useless speculations:\n");
2522 /* Inlining one function called once has good chance of preventing
2523 inlining other function into the same callee. Ideally we should
2524 work in priority order, but probably inlining hot functions first
2525 is good cut without the extra pain of maintaining the queue.
2527 ??? this is not really fitting the bill perfectly: inlining function
2528 into callee often leads to better optimization of callee due to
2529 increased context for optimization.
2530 For example if main() function calls a function that outputs help
2531 and then function that does the main optmization, we should inline
2532 the second with priority even if both calls are cold by themselves.
2534 We probably want to implement new predicate replacing our use of
2535 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2537 for (cold = 0; cold <= 1; cold ++)
2539 FOR_EACH_DEFINED_FUNCTION (node)
2541 struct cgraph_edge *edge, *next;
2544 if (!opt_for_fn (node->decl, optimize)
2545 || !opt_for_fn (node->decl, flag_inline_functions_called_once))
2548 for (edge = node->callees; edge; edge = next)
2550 next = edge->next_callee;
2551 if (edge->speculative && !speculation_useful_p (edge, false))
2553 if (edge->count.ipa ().initialized_p ())
2554 spec_rem += edge->count.ipa ();
2555 edge->resolve_speculation ();
2557 remove_functions = true;
2562 struct cgraph_node *where = node->global.inlined_to
2563 ? node->global.inlined_to : node;
2564 reset_edge_caches (where);
2565 ipa_update_overall_fn_summary (where);
2567 if (want_inline_function_to_all_callers_p (node, cold))
2570 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
2572 while (node->call_for_symbol_and_aliases
2573 (inline_to_all_callers, &num_calls, true))
2575 remove_functions = true;
2580 /* Free ipa-prop structures if they are no longer needed. */
2581 ipa_free_all_structures_after_iinln ();
2586 "\nInlined %i calls, eliminated %i functions\n\n",
2587 ncalls_inlined, nfunctions_inlined);
2588 dump_inline_stats ();
2592 ipa_dump_fn_summaries (dump_file);
2593 return remove_functions ? TODO_remove_functions : 0;
2596 /* Inline always-inline function calls in NODE. */
2599 inline_always_inline_functions (struct cgraph_node *node)
2601 struct cgraph_edge *e;
2602 bool inlined = false;
2604 for (e = node->callees; e; e = e->next_callee)
2606 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2607 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2610 if (e->recursive_p ())
2613 fprintf (dump_file, " Not inlining recursive call to %s.\n",
2614 e->callee->name ());
2615 e->inline_failed = CIF_RECURSIVE_INLINING;
2619 if (!can_early_inline_edge_p (e))
2621 /* Set inlined to true if the callee is marked "always_inline" but
2622 is not inlinable. This will allow flagging an error later in
2623 expand_call_inline in tree-inline.c. */
2624 if (lookup_attribute ("always_inline",
2625 DECL_ATTRIBUTES (callee->decl)) != NULL)
2631 fprintf (dump_file, " Inlining %s into %s (always_inline).\n",
2632 xstrdup_for_dump (e->callee->name ()),
2633 xstrdup_for_dump (e->caller->name ()));
2634 inline_call (e, true, NULL, NULL, false);
2638 ipa_update_overall_fn_summary (node);
2643 /* Decide on the inlining. We do so in the topological order to avoid
2644 expenses on updating data structures. */
2647 early_inline_small_functions (struct cgraph_node *node)
2649 struct cgraph_edge *e;
2650 bool inlined = false;
2652 for (e = node->callees; e; e = e->next_callee)
2654 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2655 if (!ipa_fn_summaries->get (callee)->inlinable
2656 || !e->inline_failed)
2659 /* Do not consider functions not declared inline. */
2660 if (!DECL_DECLARED_INLINE_P (callee->decl)
2661 && !opt_for_fn (node->decl, flag_inline_small_functions)
2662 && !opt_for_fn (node->decl, flag_inline_functions))
2666 fprintf (dump_file, "Considering inline candidate %s.\n",
2669 if (!can_early_inline_edge_p (e))
2672 if (e->recursive_p ())
2675 fprintf (dump_file, " Not inlining: recursive call.\n");
2679 if (!want_early_inline_function_p (e))
2683 fprintf (dump_file, " Inlining %s into %s.\n",
2684 xstrdup_for_dump (callee->name ()),
2685 xstrdup_for_dump (e->caller->name ()));
2686 inline_call (e, true, NULL, NULL, false);
2691 ipa_update_overall_fn_summary (node);
2697 early_inliner (function *fun)
2699 struct cgraph_node *node = cgraph_node::get (current_function_decl);
2700 struct cgraph_edge *edge;
2701 unsigned int todo = 0;
2703 bool inlined = false;
2708 /* Do nothing if datastructures for ipa-inliner are already computed. This
2709 happens when some pass decides to construct new function and
2710 cgraph_add_new_function calls lowering passes and early optimization on
2711 it. This may confuse ourself when early inliner decide to inline call to
2712 function clone, because function clones don't have parameter list in
2713 ipa-prop matching their signature. */
2714 if (ipa_node_params_sum)
2719 node->remove_all_references ();
2721 /* Rebuild this reference because it dosn't depend on
2722 function's body and it's required to pass cgraph_node
2724 if (node->instrumented_version
2725 && !node->instrumentation_clone)
2726 node->create_reference (node->instrumented_version, IPA_REF_CHKP, NULL);
2728 /* Even when not optimizing or not inlining inline always-inline
2730 inlined = inline_always_inline_functions (node);
2734 || !flag_early_inlining
2735 /* Never inline regular functions into always-inline functions
2736 during incremental inlining. This sucks as functions calling
2737 always inline functions will get less optimized, but at the
2738 same time inlining of functions calling always inline
2739 function into an always inline function might introduce
2740 cycles of edges to be always inlined in the callgraph.
2742 We might want to be smarter and just avoid this type of inlining. */
2743 || (DECL_DISREGARD_INLINE_LIMITS (node->decl)
2744 && lookup_attribute ("always_inline",
2745 DECL_ATTRIBUTES (node->decl))))
2747 else if (lookup_attribute ("flatten",
2748 DECL_ATTRIBUTES (node->decl)) != NULL)
2750 /* When the function is marked to be flattened, recursively inline
2754 "Flattening %s\n", node->name ());
2755 flatten_function (node, true);
2760 /* If some always_inline functions was inlined, apply the changes.
2761 This way we will not account always inline into growth limits and
2762 moreover we will inline calls from always inlines that we skipped
2763 previously because of conditional above. */
2766 timevar_push (TV_INTEGRATION);
2767 todo |= optimize_inline_calls (current_function_decl);
2768 /* optimize_inline_calls call above might have introduced new
2769 statements that don't have inline parameters computed. */
2770 for (edge = node->callees; edge; edge = edge->next_callee)
2772 struct ipa_call_summary *es = ipa_call_summaries->get (edge);
2774 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2776 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2778 ipa_update_overall_fn_summary (node);
2780 timevar_pop (TV_INTEGRATION);
2782 /* We iterate incremental inlining to get trivial cases of indirect
2784 while (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS)
2785 && early_inline_small_functions (node))
2787 timevar_push (TV_INTEGRATION);
2788 todo |= optimize_inline_calls (current_function_decl);
2790 /* Technically we ought to recompute inline parameters so the new
2791 iteration of early inliner works as expected. We however have
2792 values approximately right and thus we only need to update edge
2793 info that might be cleared out for newly discovered edges. */
2794 for (edge = node->callees; edge; edge = edge->next_callee)
2796 /* We have no summary for new bound store calls yet. */
2797 struct ipa_call_summary *es = ipa_call_summaries->get (edge);
2799 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2801 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2803 if (edge->callee->decl
2804 && !gimple_check_call_matching_types (
2805 edge->call_stmt, edge->callee->decl, false))
2807 edge->inline_failed = CIF_MISMATCHED_ARGUMENTS;
2808 edge->call_stmt_cannot_inline_p = true;
2811 if (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS) - 1)
2812 ipa_update_overall_fn_summary (node);
2813 timevar_pop (TV_INTEGRATION);
2818 fprintf (dump_file, "Iterations: %i\n", iterations);
2823 timevar_push (TV_INTEGRATION);
2824 todo |= optimize_inline_calls (current_function_decl);
2825 timevar_pop (TV_INTEGRATION);
2828 fun->always_inline_functions_inlined = true;
2833 /* Do inlining of small functions. Doing so early helps profiling and other
2834 passes to be somewhat more effective and avoids some code duplication in
2835 later real inlining pass for testcases with very many function calls. */
2839 const pass_data pass_data_early_inline =
2841 GIMPLE_PASS, /* type */
2842 "einline", /* name */
2843 OPTGROUP_INLINE, /* optinfo_flags */
2844 TV_EARLY_INLINING, /* tv_id */
2845 PROP_ssa, /* properties_required */
2846 0, /* properties_provided */
2847 0, /* properties_destroyed */
2848 0, /* todo_flags_start */
2849 0, /* todo_flags_finish */
2852 class pass_early_inline : public gimple_opt_pass
2855 pass_early_inline (gcc::context *ctxt)
2856 : gimple_opt_pass (pass_data_early_inline, ctxt)
2859 /* opt_pass methods: */
2860 virtual unsigned int execute (function *);
2862 }; // class pass_early_inline
2865 pass_early_inline::execute (function *fun)
2867 return early_inliner (fun);
2873 make_pass_early_inline (gcc::context *ctxt)
2875 return new pass_early_inline (ctxt);
2880 const pass_data pass_data_ipa_inline =
2882 IPA_PASS, /* type */
2883 "inline", /* name */
2884 OPTGROUP_INLINE, /* optinfo_flags */
2885 TV_IPA_INLINING, /* tv_id */
2886 0, /* properties_required */
2887 0, /* properties_provided */
2888 0, /* properties_destroyed */
2889 0, /* todo_flags_start */
2890 ( TODO_dump_symtab ), /* todo_flags_finish */
2893 class pass_ipa_inline : public ipa_opt_pass_d
2896 pass_ipa_inline (gcc::context *ctxt)
2897 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt,
2898 NULL, /* generate_summary */
2899 NULL, /* write_summary */
2900 NULL, /* read_summary */
2901 NULL, /* write_optimization_summary */
2902 NULL, /* read_optimization_summary */
2903 NULL, /* stmt_fixup */
2904 0, /* function_transform_todo_flags_start */
2905 inline_transform, /* function_transform */
2906 NULL) /* variable_transform */
2909 /* opt_pass methods: */
2910 virtual unsigned int execute (function *) { return ipa_inline (); }
2912 }; // class pass_ipa_inline
2917 make_pass_ipa_inline (gcc::context *ctxt)
2919 return new pass_ipa_inline (ctxt);