1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2015 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"
99 #include "fold-const.h"
100 #include "trans-mem.h"
102 #include "tree-inline.h"
103 #include "langhooks.h"
105 #include "diagnostic.h"
106 #include "gimple-pretty-print.h"
109 #include "tree-pass.h"
110 #include "coverage.h"
115 #include "hard-reg-set.h"
116 #include "function.h"
117 #include "basic-block.h"
118 #include "tree-ssa-alias.h"
119 #include "internal-fn.h"
120 #include "gimple-expr.h"
122 #include "gimple-ssa.h"
124 #include "alloc-pool.h"
125 #include "symbol-summary.h"
126 #include "ipa-prop.h"
129 #include "ipa-inline.h"
130 #include "ipa-utils.h"
132 #include "auto-profile.h"
133 #include "builtins.h"
134 #include "fibonacci_heap.h"
135 #include "lto-streamer.h"
137 typedef fibonacci_heap
<sreal
, cgraph_edge
> edge_heap_t
;
138 typedef fibonacci_node
<sreal
, cgraph_edge
> edge_heap_node_t
;
140 /* Statistics we collect about inlining algorithm. */
141 static int overall_size
;
142 static gcov_type max_count
;
143 static gcov_type spec_rem
;
145 /* Pre-computed constants 1/CGRAPH_FREQ_BASE and 1/100. */
146 static sreal cgraph_freq_base_rec
, percent_rec
;
148 /* Return false when inlining edge E would lead to violating
149 limits on function unit growth or stack usage growth.
151 The relative function body growth limit is present generally
152 to avoid problems with non-linear behavior of the compiler.
153 To allow inlining huge functions into tiny wrapper, the limit
154 is always based on the bigger of the two functions considered.
156 For stack growth limits we always base the growth in stack usage
157 of the callers. We want to prevent applications from segfaulting
158 on stack overflow when functions with huge stack frames gets
162 caller_growth_limits (struct cgraph_edge
*e
)
164 struct cgraph_node
*to
= e
->caller
;
165 struct cgraph_node
*what
= e
->callee
->ultimate_alias_target ();
168 HOST_WIDE_INT stack_size_limit
= 0, inlined_stack
;
169 inline_summary
*info
, *what_info
, *outer_info
= inline_summaries
->get (to
);
171 /* Look for function e->caller is inlined to. While doing
172 so work out the largest function body on the way. As
173 described above, we want to base our function growth
174 limits based on that. Not on the self size of the
175 outer function, not on the self size of inline code
176 we immediately inline to. This is the most relaxed
177 interpretation of the rule "do not grow large functions
178 too much in order to prevent compiler from exploding". */
181 info
= inline_summaries
->get (to
);
182 if (limit
< info
->self_size
)
183 limit
= info
->self_size
;
184 if (stack_size_limit
< info
->estimated_self_stack_size
)
185 stack_size_limit
= info
->estimated_self_stack_size
;
186 if (to
->global
.inlined_to
)
187 to
= to
->callers
->caller
;
192 what_info
= inline_summaries
->get (what
);
194 if (limit
< what_info
->self_size
)
195 limit
= what_info
->self_size
;
197 limit
+= limit
* PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH
) / 100;
199 /* Check the size after inlining against the function limits. But allow
200 the function to shrink if it went over the limits by forced inlining. */
201 newsize
= estimate_size_after_inlining (to
, e
);
202 if (newsize
>= info
->size
203 && newsize
> PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS
)
206 e
->inline_failed
= CIF_LARGE_FUNCTION_GROWTH_LIMIT
;
210 if (!what_info
->estimated_stack_size
)
213 /* FIXME: Stack size limit often prevents inlining in Fortran programs
214 due to large i/o datastructures used by the Fortran front-end.
215 We ought to ignore this limit when we know that the edge is executed
216 on every invocation of the caller (i.e. its call statement dominates
217 exit block). We do not track this information, yet. */
218 stack_size_limit
+= ((gcov_type
)stack_size_limit
219 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH
) / 100);
221 inlined_stack
= (outer_info
->stack_frame_offset
222 + outer_info
->estimated_self_stack_size
223 + what_info
->estimated_stack_size
);
224 /* Check new stack consumption with stack consumption at the place
226 if (inlined_stack
> stack_size_limit
227 /* If function already has large stack usage from sibling
228 inline call, we can inline, too.
229 This bit overoptimistically assume that we are good at stack
231 && inlined_stack
> info
->estimated_stack_size
232 && inlined_stack
> PARAM_VALUE (PARAM_LARGE_STACK_FRAME
))
234 e
->inline_failed
= CIF_LARGE_STACK_FRAME_GROWTH_LIMIT
;
240 /* Dump info about why inlining has failed. */
243 report_inline_failed_reason (struct cgraph_edge
*e
)
247 fprintf (dump_file
, " not inlinable: %s/%i -> %s/%i, %s\n",
248 xstrdup_for_dump (e
->caller
->name ()), e
->caller
->order
,
249 xstrdup_for_dump (e
->callee
->name ()), e
->callee
->order
,
250 cgraph_inline_failed_string (e
->inline_failed
));
251 if ((e
->inline_failed
== CIF_TARGET_OPTION_MISMATCH
252 || e
->inline_failed
== CIF_OPTIMIZATION_MISMATCH
)
253 && e
->caller
->lto_file_data
254 && e
->callee
->function_symbol ()->lto_file_data
)
256 fprintf (dump_file
, " LTO objects: %s, %s\n",
257 e
->caller
->lto_file_data
->file_name
,
258 e
->callee
->function_symbol ()->lto_file_data
->file_name
);
260 if (e
->inline_failed
== CIF_TARGET_OPTION_MISMATCH
)
261 cl_target_option_print_diff
262 (dump_file
, 2, target_opts_for_fn (e
->caller
->decl
),
263 target_opts_for_fn (e
->callee
->ultimate_alias_target ()->decl
));
264 if (e
->inline_failed
== CIF_OPTIMIZATION_MISMATCH
)
265 cl_optimization_print_diff
266 (dump_file
, 2, opts_for_fn (e
->caller
->decl
),
267 opts_for_fn (e
->callee
->ultimate_alias_target ()->decl
));
271 /* Decide whether sanitizer-related attributes allow inlining. */
274 sanitize_attrs_match_for_inline_p (const_tree caller
, const_tree callee
)
276 /* Don't care if sanitizer is disabled */
277 if (!(flag_sanitize
& SANITIZE_ADDRESS
))
280 if (!caller
|| !callee
)
283 return !!lookup_attribute ("no_sanitize_address",
284 DECL_ATTRIBUTES (caller
)) ==
285 !!lookup_attribute ("no_sanitize_address",
286 DECL_ATTRIBUTES (callee
));
289 /* Used for flags where it is safe to inline when caller's value is
290 grater than callee's. */
291 #define check_maybe_up(flag) \
292 (opts_for_fn (caller->decl)->x_##flag \
293 != opts_for_fn (callee->decl)->x_##flag \
295 || opts_for_fn (caller->decl)->x_##flag \
296 < opts_for_fn (callee->decl)->x_##flag))
297 /* Used for flags where it is safe to inline when caller's value is
298 smaller than callee's. */
299 #define check_maybe_down(flag) \
300 (opts_for_fn (caller->decl)->x_##flag \
301 != opts_for_fn (callee->decl)->x_##flag \
303 || opts_for_fn (caller->decl)->x_##flag \
304 > opts_for_fn (callee->decl)->x_##flag))
305 /* Used for flags where exact match is needed for correctness. */
306 #define check_match(flag) \
307 (opts_for_fn (caller->decl)->x_##flag \
308 != opts_for_fn (callee->decl)->x_##flag)
310 /* Decide if we can inline the edge and possibly update
311 inline_failed reason.
312 We check whether inlining is possible at all and whether
313 caller growth limits allow doing so.
315 if REPORT is true, output reason to the dump file.
317 if DISREGARD_LIMITS is true, ignore size limits.*/
320 can_inline_edge_p (struct cgraph_edge
*e
, bool report
,
321 bool disregard_limits
= false, bool early
= false)
323 gcc_checking_assert (e
->inline_failed
);
325 if (cgraph_inline_failed_type (e
->inline_failed
) == CIF_FINAL_ERROR
)
328 report_inline_failed_reason (e
);
332 bool inlinable
= true;
333 enum availability avail
;
334 cgraph_node
*callee
= e
->callee
->ultimate_alias_target (&avail
);
335 cgraph_node
*caller
= e
->caller
->global
.inlined_to
336 ? e
->caller
->global
.inlined_to
: e
->caller
;
337 tree caller_tree
= DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller
->decl
);
339 = callee
? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee
->decl
) : NULL
;
341 if (!callee
->definition
)
343 e
->inline_failed
= CIF_BODY_NOT_AVAILABLE
;
346 else if (callee
->calls_comdat_local
)
348 e
->inline_failed
= CIF_USES_COMDAT_LOCAL
;
351 else if (avail
<= AVAIL_INTERPOSABLE
)
353 e
->inline_failed
= CIF_OVERWRITABLE
;
356 else if (e
->call_stmt_cannot_inline_p
)
358 if (e
->inline_failed
!= CIF_FUNCTION_NOT_OPTIMIZED
)
359 e
->inline_failed
= CIF_MISMATCHED_ARGUMENTS
;
362 /* Don't inline if the functions have different EH personalities. */
363 else if (DECL_FUNCTION_PERSONALITY (caller
->decl
)
364 && DECL_FUNCTION_PERSONALITY (callee
->decl
)
365 && (DECL_FUNCTION_PERSONALITY (caller
->decl
)
366 != DECL_FUNCTION_PERSONALITY (callee
->decl
)))
368 e
->inline_failed
= CIF_EH_PERSONALITY
;
371 /* TM pure functions should not be inlined into non-TM_pure
373 else if (is_tm_pure (callee
->decl
) && !is_tm_pure (caller
->decl
))
375 e
->inline_failed
= CIF_UNSPECIFIED
;
378 /* Check compatibility of target optimization options. */
379 else if (!targetm
.target_option
.can_inline_p (caller
->decl
,
382 e
->inline_failed
= CIF_TARGET_OPTION_MISMATCH
;
385 else if (!inline_summaries
->get (callee
)->inlinable
)
387 e
->inline_failed
= CIF_FUNCTION_NOT_INLINABLE
;
390 else if (inline_summaries
->get (caller
)->contains_cilk_spawn
)
392 e
->inline_failed
= CIF_CILK_SPAWN
;
395 /* Don't inline a function with mismatched sanitization attributes. */
396 else if (!sanitize_attrs_match_for_inline_p (caller
->decl
, callee
->decl
))
398 e
->inline_failed
= CIF_ATTRIBUTE_MISMATCH
;
401 /* Check if caller growth allows the inlining. */
402 else if (!DECL_DISREGARD_INLINE_LIMITS (callee
->decl
)
404 && !lookup_attribute ("flatten",
405 DECL_ATTRIBUTES (caller
->decl
))
406 && !caller_growth_limits (e
))
408 /* Don't inline a function with a higher optimization level than the
409 caller. FIXME: this is really just tip of iceberg of handling
410 optimization attribute. */
411 else if (caller_tree
!= callee_tree
)
414 (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
)
415 && lookup_attribute ("always_inline",
416 DECL_ATTRIBUTES (callee
->decl
)));
418 /* Until GCC 4.9 we did not check the semantics alterning flags
419 bellow and inline across optimization boundry.
420 Enabling checks bellow breaks several packages by refusing
421 to inline library always_inline functions. See PR65873.
422 Disable the check for early inlining for now until better solution
424 if (always_inline
&& early
)
426 /* There are some options that change IL semantics which means
427 we cannot inline in these cases for correctness reason.
428 Not even for always_inline declared functions. */
429 /* Strictly speaking only when the callee contains signed integer
430 math where overflow is undefined. */
431 else if ((check_maybe_up (flag_strict_overflow
)
432 /* this flag is set by optimize. Allow inlining across
433 optimize boundary. */
434 && (!opt_for_fn (caller
->decl
, optimize
)
435 == !opt_for_fn (callee
->decl
, optimize
) || !always_inline
))
436 || check_match (flag_wrapv
)
437 || check_match (flag_trapv
)
438 /* Strictly speaking only when the callee uses FP math. */
439 || check_maybe_up (flag_rounding_math
)
440 || check_maybe_up (flag_trapping_math
)
441 || check_maybe_down (flag_unsafe_math_optimizations
)
442 || check_maybe_down (flag_finite_math_only
)
443 || check_maybe_up (flag_signaling_nans
)
444 || check_maybe_down (flag_cx_limited_range
)
445 || check_maybe_up (flag_signed_zeros
)
446 || check_maybe_down (flag_associative_math
)
447 || check_maybe_down (flag_reciprocal_math
)
448 /* We do not want to make code compiled with exceptions to be
449 brought into a non-EH function unless we know that the callee
451 This is tracked by DECL_FUNCTION_PERSONALITY. */
452 || (check_match (flag_non_call_exceptions
)
453 /* TODO: We also may allow bringing !flag_non_call_exceptions
454 to flag_non_call_exceptions function, but that may need
455 extra work in tree-inline to add the extra EH edges. */
456 && (!opt_for_fn (callee
->decl
, flag_non_call_exceptions
)
457 || DECL_FUNCTION_PERSONALITY (callee
->decl
)))
458 || (check_maybe_up (flag_exceptions
)
459 && DECL_FUNCTION_PERSONALITY (callee
->decl
))
460 /* Strictly speaking only when the callee contains function
461 calls that may end up setting errno. */
462 || check_maybe_up (flag_errno_math
)
463 /* When devirtualization is diabled for callee, it is not safe
464 to inline it as we possibly mangled the type info.
465 Allow early inlining of always inlines. */
466 || (!early
&& check_maybe_down (flag_devirtualize
)))
468 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
471 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
472 else if (always_inline
)
474 /* When user added an attribute to the callee honor it. */
475 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee
->decl
))
476 && opts_for_fn (caller
->decl
) != opts_for_fn (callee
->decl
))
478 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
481 /* If explicit optimize attribute are not used, the mismatch is caused
482 by different command line options used to build different units.
483 Do not care about COMDAT functions - those are intended to be
484 optimized with the optimization flags of module they are used in.
485 Also do not care about mixing up size/speed optimization when
486 DECL_DISREGARD_INLINE_LIMITS is set. */
487 else if ((callee
->merged
488 && !lookup_attribute ("optimize",
489 DECL_ATTRIBUTES (caller
->decl
)))
490 || DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
492 /* If mismatch is caused by merging two LTO units with different
493 optimizationflags we want to be bit nicer. However never inline
494 if one of functions is not optimized at all. */
495 else if (!opt_for_fn (callee
->decl
, optimize
)
496 || !opt_for_fn (caller
->decl
, optimize
))
498 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
501 /* If callee is optimized for size and caller is not, allow inlining if
502 code shrinks or we are in MAX_INLINE_INSNS_SINGLE limit and callee
503 is inline (and thus likely an unified comdat). This will allow caller
505 else if (opt_for_fn (callee
->decl
, optimize_size
)
506 > opt_for_fn (caller
->decl
, optimize_size
))
508 int growth
= estimate_edge_growth (e
);
510 && (!DECL_DECLARED_INLINE_P (callee
->decl
)
511 && growth
>= MAX (MAX_INLINE_INSNS_SINGLE
,
512 MAX_INLINE_INSNS_AUTO
)))
514 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
518 /* If callee is more aggressively optimized for performance than caller,
519 we generally want to inline only cheap (runtime wise) functions. */
520 else if (opt_for_fn (callee
->decl
, optimize_size
)
521 < opt_for_fn (caller
->decl
, optimize_size
)
522 || (opt_for_fn (callee
->decl
, optimize
)
523 > opt_for_fn (caller
->decl
, optimize
)))
525 if (estimate_edge_time (e
)
526 >= 20 + inline_edge_summary (e
)->call_stmt_time
)
528 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
535 if (!inlinable
&& report
)
536 report_inline_failed_reason (e
);
541 /* Return true if the edge E is inlinable during early inlining. */
544 can_early_inline_edge_p (struct cgraph_edge
*e
)
546 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
547 /* Early inliner might get called at WPA stage when IPA pass adds new
548 function. In this case we can not really do any of early inlining
549 because function bodies are missing. */
550 if (!gimple_has_body_p (callee
->decl
))
552 e
->inline_failed
= CIF_BODY_NOT_AVAILABLE
;
555 /* In early inliner some of callees may not be in SSA form yet
556 (i.e. the callgraph is cyclic and we did not process
557 the callee by early inliner, yet). We don't have CIF code for this
558 case; later we will re-do the decision in the real inliner. */
559 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e
->caller
->decl
))
560 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee
->decl
)))
563 fprintf (dump_file
, " edge not inlinable: not in SSA form\n");
566 if (!can_inline_edge_p (e
, true, false, true))
572 /* Return number of calls in N. Ignore cheap builtins. */
575 num_calls (struct cgraph_node
*n
)
577 struct cgraph_edge
*e
;
580 for (e
= n
->callees
; e
; e
= e
->next_callee
)
581 if (!is_inexpensive_builtin (e
->callee
->decl
))
587 /* Return true if we are interested in inlining small function. */
590 want_early_inline_function_p (struct cgraph_edge
*e
)
592 bool want_inline
= true;
593 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
595 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
597 /* For AutoFDO, we need to make sure that before profile summary, all
598 hot paths' IR look exactly the same as profiled binary. As a result,
599 in einliner, we will disregard size limit and inline those callsites
601 * inlined in the profiled binary, and
602 * the cloned callee has enough samples to be considered "hot". */
603 else if (flag_auto_profile
&& afdo_callsite_hot_enough_for_early_inline (e
))
605 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
606 && !opt_for_fn (e
->caller
->decl
, flag_inline_small_functions
))
608 e
->inline_failed
= CIF_FUNCTION_NOT_INLINE_CANDIDATE
;
609 report_inline_failed_reason (e
);
614 int growth
= estimate_edge_growth (e
);
619 else if (!e
->maybe_hot_p ()
623 fprintf (dump_file
, " will not early inline: %s/%i->%s/%i, "
624 "call is cold and code would grow by %i\n",
625 xstrdup_for_dump (e
->caller
->name ()),
627 xstrdup_for_dump (callee
->name ()), callee
->order
,
631 else if (growth
> PARAM_VALUE (PARAM_EARLY_INLINING_INSNS
))
634 fprintf (dump_file
, " will not early inline: %s/%i->%s/%i, "
635 "growth %i exceeds --param early-inlining-insns\n",
636 xstrdup_for_dump (e
->caller
->name ()),
638 xstrdup_for_dump (callee
->name ()), callee
->order
,
642 else if ((n
= num_calls (callee
)) != 0
643 && growth
* (n
+ 1) > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS
))
646 fprintf (dump_file
, " will not early inline: %s/%i->%s/%i, "
647 "growth %i exceeds --param early-inlining-insns "
648 "divided by number of calls\n",
649 xstrdup_for_dump (e
->caller
->name ()),
651 xstrdup_for_dump (callee
->name ()), callee
->order
,
659 /* Compute time of the edge->caller + edge->callee execution when inlining
663 compute_uninlined_call_time (struct inline_summary
*callee_info
,
664 struct cgraph_edge
*edge
)
666 sreal uninlined_call_time
= (sreal
)callee_info
->time
;
667 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
668 ? edge
->caller
->global
.inlined_to
671 if (edge
->count
&& caller
->count
)
672 uninlined_call_time
*= (sreal
)edge
->count
/ caller
->count
;
674 uninlined_call_time
*= cgraph_freq_base_rec
* edge
->frequency
;
676 uninlined_call_time
= uninlined_call_time
>> 11;
678 int caller_time
= inline_summaries
->get (caller
)->time
;
679 return uninlined_call_time
+ caller_time
;
682 /* Same as compute_uinlined_call_time but compute time when inlining
686 compute_inlined_call_time (struct cgraph_edge
*edge
,
689 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
690 ? edge
->caller
->global
.inlined_to
692 int caller_time
= inline_summaries
->get (caller
)->time
;
693 sreal time
= edge_time
;
695 if (edge
->count
&& caller
->count
)
696 time
*= (sreal
)edge
->count
/ caller
->count
;
698 time
*= cgraph_freq_base_rec
* edge
->frequency
;
702 /* This calculation should match one in ipa-inline-analysis.
703 FIXME: Once ipa-inline-analysis is converted to sreal this can be
705 time
-= (sreal
) ((gcov_type
) edge
->frequency
706 * inline_edge_summary (edge
)->call_stmt_time
707 * (INLINE_TIME_SCALE
/ CGRAPH_FREQ_BASE
)) / INLINE_TIME_SCALE
;
710 time
= ((sreal
) 1) >> 8;
711 gcc_checking_assert (time
>= 0);
715 /* Return true if the speedup for inlining E is bigger than
716 PARAM_MAX_INLINE_MIN_SPEEDUP. */
719 big_speedup_p (struct cgraph_edge
*e
)
721 sreal time
= compute_uninlined_call_time (inline_summaries
->get (e
->callee
),
723 sreal inlined_time
= compute_inlined_call_time (e
, estimate_edge_time (e
));
725 if (time
- inlined_time
726 > (sreal
) time
* PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP
)
732 /* Return true if we are interested in inlining small function.
733 When REPORT is true, report reason to dump file. */
736 want_inline_small_function_p (struct cgraph_edge
*e
, bool report
)
738 bool want_inline
= true;
739 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
741 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
743 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
744 && !opt_for_fn (e
->caller
->decl
, flag_inline_small_functions
))
746 e
->inline_failed
= CIF_FUNCTION_NOT_INLINE_CANDIDATE
;
749 /* Do fast and conservative check if the function can be good
750 inline candidate. At the moment we allow inline hints to
751 promote non-inline functions to inline and we increase
752 MAX_INLINE_INSNS_SINGLE 16-fold for inline functions. */
753 else if ((!DECL_DECLARED_INLINE_P (callee
->decl
)
754 && (!e
->count
|| !e
->maybe_hot_p ()))
755 && inline_summaries
->get (callee
)->min_size
756 - inline_edge_summary (e
)->call_stmt_size
757 > MAX (MAX_INLINE_INSNS_SINGLE
, MAX_INLINE_INSNS_AUTO
))
759 e
->inline_failed
= CIF_MAX_INLINE_INSNS_AUTO_LIMIT
;
762 else if ((DECL_DECLARED_INLINE_P (callee
->decl
) || e
->count
)
763 && inline_summaries
->get (callee
)->min_size
764 - inline_edge_summary (e
)->call_stmt_size
765 > 16 * MAX_INLINE_INSNS_SINGLE
)
767 e
->inline_failed
= (DECL_DECLARED_INLINE_P (callee
->decl
)
768 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
769 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT
);
774 int growth
= estimate_edge_growth (e
);
775 inline_hints hints
= estimate_edge_hints (e
);
776 bool big_speedup
= big_speedup_p (e
);
780 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when
781 hints suggests that inlining given function is very profitable. */
782 else if (DECL_DECLARED_INLINE_P (callee
->decl
)
783 && growth
>= MAX_INLINE_INSNS_SINGLE
785 && !(hints
& (INLINE_HINT_indirect_call
786 | INLINE_HINT_known_hot
787 | INLINE_HINT_loop_iterations
788 | INLINE_HINT_array_index
789 | INLINE_HINT_loop_stride
)))
790 || growth
>= MAX_INLINE_INSNS_SINGLE
* 16))
792 e
->inline_failed
= CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
;
795 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
796 && !opt_for_fn (e
->caller
->decl
, flag_inline_functions
))
798 /* growth_likely_positive is expensive, always test it last. */
799 if (growth
>= MAX_INLINE_INSNS_SINGLE
800 || growth_likely_positive (callee
, growth
))
802 e
->inline_failed
= CIF_NOT_DECLARED_INLINED
;
806 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline
807 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that
808 inlining given function is very profitable. */
809 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
811 && !(hints
& INLINE_HINT_known_hot
)
812 && growth
>= ((hints
& (INLINE_HINT_indirect_call
813 | INLINE_HINT_loop_iterations
814 | INLINE_HINT_array_index
815 | INLINE_HINT_loop_stride
))
816 ? MAX (MAX_INLINE_INSNS_AUTO
,
817 MAX_INLINE_INSNS_SINGLE
)
818 : MAX_INLINE_INSNS_AUTO
))
820 /* growth_likely_positive is expensive, always test it last. */
821 if (growth
>= MAX_INLINE_INSNS_SINGLE
822 || growth_likely_positive (callee
, growth
))
824 e
->inline_failed
= CIF_MAX_INLINE_INSNS_AUTO_LIMIT
;
828 /* If call is cold, do not inline when function body would grow. */
829 else if (!e
->maybe_hot_p ()
830 && (growth
>= MAX_INLINE_INSNS_SINGLE
831 || growth_likely_positive (callee
, growth
)))
833 e
->inline_failed
= CIF_UNLIKELY_CALL
;
837 if (!want_inline
&& report
)
838 report_inline_failed_reason (e
);
842 /* EDGE is self recursive edge.
843 We hand two cases - when function A is inlining into itself
844 or when function A is being inlined into another inliner copy of function
847 In first case OUTER_NODE points to the toplevel copy of A, while
848 in the second case OUTER_NODE points to the outermost copy of A in B.
850 In both cases we want to be extra selective since
851 inlining the call will just introduce new recursive calls to appear. */
854 want_inline_self_recursive_call_p (struct cgraph_edge
*edge
,
855 struct cgraph_node
*outer_node
,
859 char const *reason
= NULL
;
860 bool want_inline
= true;
861 int caller_freq
= CGRAPH_FREQ_BASE
;
862 int max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO
);
864 if (DECL_DECLARED_INLINE_P (edge
->caller
->decl
))
865 max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH
);
867 if (!edge
->maybe_hot_p ())
869 reason
= "recursive call is cold";
872 else if (max_count
&& !outer_node
->count
)
874 reason
= "not executed in profile";
877 else if (depth
> max_depth
)
879 reason
= "--param max-inline-recursive-depth exceeded.";
883 if (outer_node
->global
.inlined_to
)
884 caller_freq
= outer_node
->callers
->frequency
;
888 reason
= "function is inlined and unlikely";
894 /* Inlining of self recursive function into copy of itself within other function
895 is transformation similar to loop peeling.
897 Peeling is profitable if we can inline enough copies to make probability
898 of actual call to the self recursive function very small. Be sure that
899 the probability of recursion is small.
901 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
902 This way the expected number of recision is at most max_depth. */
905 int max_prob
= CGRAPH_FREQ_BASE
- ((CGRAPH_FREQ_BASE
+ max_depth
- 1)
908 for (i
= 1; i
< depth
; i
++)
909 max_prob
= max_prob
* max_prob
/ CGRAPH_FREQ_BASE
;
911 && (edge
->count
* CGRAPH_FREQ_BASE
/ outer_node
->count
914 reason
= "profile of recursive call is too large";
918 && (edge
->frequency
* CGRAPH_FREQ_BASE
/ caller_freq
921 reason
= "frequency of recursive call is too large";
925 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if recursion
926 depth is large. We reduce function call overhead and increase chances that
927 things fit in hardware return predictor.
929 Recursive inlining might however increase cost of stack frame setup
930 actually slowing down functions whose recursion tree is wide rather than
933 Deciding reliably on when to do recursive inlining without profile feedback
934 is tricky. For now we disable recursive inlining when probability of self
937 Recursive inlining of self recursive call within loop also results in large loop
938 depths that generally optimize badly. We may want to throttle down inlining
939 in those cases. In particular this seems to happen in one of libstdc++ rb tree
944 && (edge
->count
* 100 / outer_node
->count
945 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY
)))
947 reason
= "profile of recursive call is too small";
951 && (edge
->frequency
* 100 / caller_freq
952 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY
)))
954 reason
= "frequency of recursive call is too small";
958 if (!want_inline
&& dump_file
)
959 fprintf (dump_file
, " not inlining recursively: %s\n", reason
);
963 /* Return true when NODE has uninlinable caller;
964 set HAS_HOT_CALL if it has hot call.
965 Worker for cgraph_for_node_and_aliases. */
968 check_callers (struct cgraph_node
*node
, void *has_hot_call
)
970 struct cgraph_edge
*e
;
971 for (e
= node
->callers
; e
; e
= e
->next_caller
)
973 if (!opt_for_fn (e
->caller
->decl
, flag_inline_functions_called_once
))
975 if (!can_inline_edge_p (e
, true))
977 if (e
->recursive_p ())
979 if (!(*(bool *)has_hot_call
) && e
->maybe_hot_p ())
980 *(bool *)has_hot_call
= true;
985 /* If NODE has a caller, return true. */
988 has_caller_p (struct cgraph_node
*node
, void *data ATTRIBUTE_UNUSED
)
995 /* Decide if inlining NODE would reduce unit size by eliminating
996 the offline copy of function.
997 When COLD is true the cold calls are considered, too. */
1000 want_inline_function_to_all_callers_p (struct cgraph_node
*node
, bool cold
)
1002 bool has_hot_call
= false;
1004 /* Aliases gets inlined along with the function they alias. */
1007 /* Already inlined? */
1008 if (node
->global
.inlined_to
)
1010 /* Does it have callers? */
1011 if (!node
->call_for_symbol_and_aliases (has_caller_p
, NULL
, true))
1013 /* Inlining into all callers would increase size? */
1014 if (estimate_growth (node
) > 0)
1016 /* All inlines must be possible. */
1017 if (node
->call_for_symbol_and_aliases (check_callers
, &has_hot_call
,
1020 if (!cold
&& !has_hot_call
)
1025 /* A cost model driving the inlining heuristics in a way so the edges with
1026 smallest badness are inlined first. After each inlining is performed
1027 the costs of all caller edges of nodes affected are recomputed so the
1028 metrics may accurately depend on values such as number of inlinable callers
1029 of the function or function body size. */
1032 edge_badness (struct cgraph_edge
*edge
, bool dump
)
1035 int growth
, edge_time
;
1036 struct cgraph_node
*callee
= edge
->callee
->ultimate_alias_target ();
1037 struct inline_summary
*callee_info
= inline_summaries
->get (callee
);
1039 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
1040 ? edge
->caller
->global
.inlined_to
1043 growth
= estimate_edge_growth (edge
);
1044 edge_time
= estimate_edge_time (edge
);
1045 hints
= estimate_edge_hints (edge
);
1046 gcc_checking_assert (edge_time
>= 0);
1047 gcc_checking_assert (edge_time
<= callee_info
->time
);
1048 gcc_checking_assert (growth
<= callee_info
->size
);
1052 fprintf (dump_file
, " Badness calculation for %s/%i -> %s/%i\n",
1053 xstrdup_for_dump (edge
->caller
->name ()),
1054 edge
->caller
->order
,
1055 xstrdup_for_dump (callee
->name ()),
1056 edge
->callee
->order
);
1057 fprintf (dump_file
, " size growth %i, time %i ",
1060 dump_inline_hints (dump_file
, hints
);
1061 if (big_speedup_p (edge
))
1062 fprintf (dump_file
, " big_speedup");
1063 fprintf (dump_file
, "\n");
1066 /* Always prefer inlining saving code size. */
1069 badness
= (sreal
) (-SREAL_MIN_SIG
+ growth
) << (SREAL_MAX_EXP
/ 256);
1071 fprintf (dump_file
, " %f: Growth %d <= 0\n", badness
.to_double (),
1074 /* Inlining into EXTERNAL functions is not going to change anything unless
1075 they are themselves inlined. */
1076 else if (DECL_EXTERNAL (caller
->decl
))
1079 fprintf (dump_file
, " max: function is external\n");
1080 return sreal::max ();
1082 /* When profile is available. Compute badness as:
1084 time_saved * caller_count
1085 goodness = -------------------------------------------------
1086 growth_of_caller * overall_growth * combined_size
1088 badness = - goodness
1090 Again use negative value to make calls with profile appear hotter
1093 else if (opt_for_fn (caller
->decl
, flag_guess_branch_prob
) || caller
->count
)
1095 sreal numerator
, denominator
;
1098 numerator
= (compute_uninlined_call_time (callee_info
, edge
)
1099 - compute_inlined_call_time (edge
, edge_time
));
1101 numerator
= ((sreal
) 1 >> 8);
1103 numerator
*= caller
->count
;
1104 else if (opt_for_fn (caller
->decl
, flag_branch_probabilities
))
1105 numerator
= numerator
>> 11;
1106 denominator
= growth
;
1108 overall_growth
= callee_info
->growth
;
1110 /* Look for inliner wrappers of the form:
1116 noninline_callee ();
1118 Withhout panilizing this case, we usually inline noninline_callee
1119 into the inline_caller because overall_growth is small preventing
1120 further inlining of inline_caller.
1122 Penalize only callgraph edges to functions with small overall
1125 if (growth
> overall_growth
1126 /* ... and having only one caller which is not inlined ... */
1127 && callee_info
->single_caller
1128 && !edge
->caller
->global
.inlined_to
1129 /* ... and edges executed only conditionally ... */
1130 && edge
->frequency
< CGRAPH_FREQ_BASE
1131 /* ... consider case where callee is not inline but caller is ... */
1132 && ((!DECL_DECLARED_INLINE_P (edge
->callee
->decl
)
1133 && DECL_DECLARED_INLINE_P (caller
->decl
))
1134 /* ... or when early optimizers decided to split and edge
1135 frequency still indicates splitting is a win ... */
1136 || (callee
->split_part
&& !caller
->split_part
1140 (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY
) / 100
1141 /* ... and do not overwrite user specified hints. */
1142 && (!DECL_DECLARED_INLINE_P (edge
->callee
->decl
)
1143 || DECL_DECLARED_INLINE_P (caller
->decl
)))))
1145 struct inline_summary
*caller_info
= inline_summaries
->get (caller
);
1146 int caller_growth
= caller_info
->growth
;
1148 /* Only apply the penalty when caller looks like inline candidate,
1149 and it is not called once and. */
1150 if (!caller_info
->single_caller
&& overall_growth
< caller_growth
1151 && caller_info
->inlinable
1152 && caller_info
->size
1153 < (DECL_DECLARED_INLINE_P (caller
->decl
)
1154 ? MAX_INLINE_INSNS_SINGLE
: MAX_INLINE_INSNS_AUTO
))
1158 " Wrapper penalty. Increasing growth %i to %i\n",
1159 overall_growth
, caller_growth
);
1160 overall_growth
= caller_growth
;
1163 if (overall_growth
> 0)
1165 /* Strongly preffer functions with few callers that can be inlined
1166 fully. The square root here leads to smaller binaries at average.
1167 Watch however for extreme cases and return to linear function
1168 when growth is large. */
1169 if (overall_growth
< 256)
1170 overall_growth
*= overall_growth
;
1172 overall_growth
+= 256 * 256 - 256;
1173 denominator
*= overall_growth
;
1175 denominator
*= inline_summaries
->get (caller
)->self_size
+ growth
;
1177 badness
= - numerator
/ denominator
;
1182 " %f: guessed profile. frequency %f, count %" PRId64
1183 " caller count %" PRId64
1184 " time w/o inlining %f, time w inlining %f"
1185 " overall growth %i (current) %i (original)"
1186 " %i (compensated)\n",
1187 badness
.to_double (),
1188 (double)edge
->frequency
/ CGRAPH_FREQ_BASE
,
1189 edge
->count
, caller
->count
,
1190 compute_uninlined_call_time (callee_info
, edge
).to_double (),
1191 compute_inlined_call_time (edge
, edge_time
).to_double (),
1192 estimate_growth (callee
),
1193 callee_info
->growth
, overall_growth
);
1196 /* When function local profile is not available or it does not give
1197 useful information (ie frequency is zero), base the cost on
1198 loop nest and overall size growth, so we optimize for overall number
1199 of functions fully inlined in program. */
1202 int nest
= MIN (inline_edge_summary (edge
)->loop_depth
, 8);
1205 /* Decrease badness if call is nested. */
1207 badness
= badness
>> nest
;
1209 badness
= badness
<< nest
;
1211 fprintf (dump_file
, " %f: no profile. nest %i\n",
1212 badness
.to_double (), nest
);
1214 gcc_checking_assert (badness
!= 0);
1216 if (edge
->recursive_p ())
1217 badness
= badness
.shift (badness
> 0 ? 4 : -4);
1218 if ((hints
& (INLINE_HINT_indirect_call
1219 | INLINE_HINT_loop_iterations
1220 | INLINE_HINT_array_index
1221 | INLINE_HINT_loop_stride
))
1222 || callee_info
->growth
<= 0)
1223 badness
= badness
.shift (badness
> 0 ? -2 : 2);
1224 if (hints
& (INLINE_HINT_same_scc
))
1225 badness
= badness
.shift (badness
> 0 ? 3 : -3);
1226 else if (hints
& (INLINE_HINT_in_scc
))
1227 badness
= badness
.shift (badness
> 0 ? 2 : -2);
1228 else if (hints
& (INLINE_HINT_cross_module
))
1229 badness
= badness
.shift (badness
> 0 ? 1 : -1);
1230 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
1231 badness
= badness
.shift (badness
> 0 ? -4 : 4);
1232 else if ((hints
& INLINE_HINT_declared_inline
))
1233 badness
= badness
.shift (badness
> 0 ? -3 : 3);
1235 fprintf (dump_file
, " Adjusted by hints %f\n", badness
.to_double ());
1239 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1241 update_edge_key (edge_heap_t
*heap
, struct cgraph_edge
*edge
)
1243 sreal badness
= edge_badness (edge
, false);
1246 edge_heap_node_t
*n
= (edge_heap_node_t
*) edge
->aux
;
1247 gcc_checking_assert (n
->get_data () == edge
);
1249 /* fibonacci_heap::replace_key does busy updating of the
1250 heap that is unnecesarily expensive.
1251 We do lazy increases: after extracting minimum if the key
1252 turns out to be out of date, it is re-inserted into heap
1253 with correct value. */
1254 if (badness
< n
->get_key ())
1256 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1259 " decreasing badness %s/%i -> %s/%i, %f"
1261 xstrdup_for_dump (edge
->caller
->name ()),
1262 edge
->caller
->order
,
1263 xstrdup_for_dump (edge
->callee
->name ()),
1264 edge
->callee
->order
,
1265 n
->get_key ().to_double (),
1266 badness
.to_double ());
1268 heap
->decrease_key (n
, badness
);
1273 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1276 " enqueuing call %s/%i -> %s/%i, badness %f\n",
1277 xstrdup_for_dump (edge
->caller
->name ()),
1278 edge
->caller
->order
,
1279 xstrdup_for_dump (edge
->callee
->name ()),
1280 edge
->callee
->order
,
1281 badness
.to_double ());
1283 edge
->aux
= heap
->insert (badness
, edge
);
1288 /* NODE was inlined.
1289 All caller edges needs to be resetted because
1290 size estimates change. Similarly callees needs reset
1291 because better context may be known. */
1294 reset_edge_caches (struct cgraph_node
*node
)
1296 struct cgraph_edge
*edge
;
1297 struct cgraph_edge
*e
= node
->callees
;
1298 struct cgraph_node
*where
= node
;
1299 struct ipa_ref
*ref
;
1301 if (where
->global
.inlined_to
)
1302 where
= where
->global
.inlined_to
;
1304 for (edge
= where
->callers
; edge
; edge
= edge
->next_caller
)
1305 if (edge
->inline_failed
)
1306 reset_edge_growth_cache (edge
);
1308 FOR_EACH_ALIAS (where
, ref
)
1309 reset_edge_caches (dyn_cast
<cgraph_node
*> (ref
->referring
));
1315 if (!e
->inline_failed
&& e
->callee
->callees
)
1316 e
= e
->callee
->callees
;
1319 if (e
->inline_failed
)
1320 reset_edge_growth_cache (e
);
1327 if (e
->caller
== node
)
1329 e
= e
->caller
->callers
;
1331 while (!e
->next_callee
);
1337 /* Recompute HEAP nodes for each of caller of NODE.
1338 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1339 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1340 it is inlinable. Otherwise check all edges. */
1343 update_caller_keys (edge_heap_t
*heap
, struct cgraph_node
*node
,
1344 bitmap updated_nodes
,
1345 struct cgraph_edge
*check_inlinablity_for
)
1347 struct cgraph_edge
*edge
;
1348 struct ipa_ref
*ref
;
1350 if ((!node
->alias
&& !inline_summaries
->get (node
)->inlinable
)
1351 || node
->global
.inlined_to
)
1353 if (!bitmap_set_bit (updated_nodes
, node
->uid
))
1356 FOR_EACH_ALIAS (node
, ref
)
1358 struct cgraph_node
*alias
= dyn_cast
<cgraph_node
*> (ref
->referring
);
1359 update_caller_keys (heap
, alias
, updated_nodes
, check_inlinablity_for
);
1362 for (edge
= node
->callers
; edge
; edge
= edge
->next_caller
)
1363 if (edge
->inline_failed
)
1365 if (!check_inlinablity_for
1366 || check_inlinablity_for
== edge
)
1368 if (can_inline_edge_p (edge
, false)
1369 && want_inline_small_function_p (edge
, false))
1370 update_edge_key (heap
, edge
);
1373 report_inline_failed_reason (edge
);
1374 heap
->delete_node ((edge_heap_node_t
*) edge
->aux
);
1379 update_edge_key (heap
, edge
);
1383 /* Recompute HEAP nodes for each uninlined call in NODE.
1384 This is used when we know that edge badnesses are going only to increase
1385 (we introduced new call site) and thus all we need is to insert newly
1386 created edges into heap. */
1389 update_callee_keys (edge_heap_t
*heap
, struct cgraph_node
*node
,
1390 bitmap updated_nodes
)
1392 struct cgraph_edge
*e
= node
->callees
;
1397 if (!e
->inline_failed
&& e
->callee
->callees
)
1398 e
= e
->callee
->callees
;
1401 enum availability avail
;
1402 struct cgraph_node
*callee
;
1403 /* We do not reset callee growth cache here. Since we added a new call,
1404 growth chould have just increased and consequentely badness metric
1405 don't need updating. */
1406 if (e
->inline_failed
1407 && (callee
= e
->callee
->ultimate_alias_target (&avail
))
1408 && inline_summaries
->get (callee
)->inlinable
1409 && avail
>= AVAIL_AVAILABLE
1410 && !bitmap_bit_p (updated_nodes
, callee
->uid
))
1412 if (can_inline_edge_p (e
, false)
1413 && want_inline_small_function_p (e
, false))
1414 update_edge_key (heap
, e
);
1417 report_inline_failed_reason (e
);
1418 heap
->delete_node ((edge_heap_node_t
*) e
->aux
);
1428 if (e
->caller
== node
)
1430 e
= e
->caller
->callers
;
1432 while (!e
->next_callee
);
1438 /* Enqueue all recursive calls from NODE into priority queue depending on
1439 how likely we want to recursively inline the call. */
1442 lookup_recursive_calls (struct cgraph_node
*node
, struct cgraph_node
*where
,
1445 struct cgraph_edge
*e
;
1446 enum availability avail
;
1448 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1449 if (e
->callee
== node
1450 || (e
->callee
->ultimate_alias_target (&avail
) == node
1451 && avail
> AVAIL_INTERPOSABLE
))
1453 /* When profile feedback is available, prioritize by expected number
1455 heap
->insert (!max_count
? -e
->frequency
1456 : -(e
->count
/ ((max_count
+ (1<<24) - 1) / (1<<24))),
1459 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1460 if (!e
->inline_failed
)
1461 lookup_recursive_calls (node
, e
->callee
, heap
);
1464 /* Decide on recursive inlining: in the case function has recursive calls,
1465 inline until body size reaches given argument. If any new indirect edges
1466 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1470 recursive_inlining (struct cgraph_edge
*edge
,
1471 vec
<cgraph_edge
*> *new_edges
)
1473 int limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO
);
1474 edge_heap_t
heap (sreal::min ());
1475 struct cgraph_node
*node
;
1476 struct cgraph_edge
*e
;
1477 struct cgraph_node
*master_clone
= NULL
, *next
;
1481 node
= edge
->caller
;
1482 if (node
->global
.inlined_to
)
1483 node
= node
->global
.inlined_to
;
1485 if (DECL_DECLARED_INLINE_P (node
->decl
))
1486 limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE
);
1488 /* Make sure that function is small enough to be considered for inlining. */
1489 if (estimate_size_after_inlining (node
, edge
) >= limit
)
1491 lookup_recursive_calls (node
, node
, &heap
);
1497 " Performing recursive inlining on %s\n",
1500 /* Do the inlining and update list of recursive call during process. */
1501 while (!heap
.empty ())
1503 struct cgraph_edge
*curr
= heap
.extract_min ();
1504 struct cgraph_node
*cnode
, *dest
= curr
->callee
;
1506 if (!can_inline_edge_p (curr
, true))
1509 /* MASTER_CLONE is produced in the case we already started modified
1510 the function. Be sure to redirect edge to the original body before
1511 estimating growths otherwise we will be seeing growths after inlining
1512 the already modified body. */
1515 curr
->redirect_callee (master_clone
);
1516 reset_edge_growth_cache (curr
);
1519 if (estimate_size_after_inlining (node
, curr
) > limit
)
1521 curr
->redirect_callee (dest
);
1522 reset_edge_growth_cache (curr
);
1527 for (cnode
= curr
->caller
;
1528 cnode
->global
.inlined_to
; cnode
= cnode
->callers
->caller
)
1530 == curr
->callee
->ultimate_alias_target ()->decl
)
1533 if (!want_inline_self_recursive_call_p (curr
, node
, false, depth
))
1535 curr
->redirect_callee (dest
);
1536 reset_edge_growth_cache (curr
);
1543 " Inlining call of depth %i", depth
);
1546 fprintf (dump_file
, " called approx. %.2f times per call",
1547 (double)curr
->count
/ node
->count
);
1549 fprintf (dump_file
, "\n");
1553 /* We need original clone to copy around. */
1554 master_clone
= node
->create_clone (node
->decl
, node
->count
,
1555 CGRAPH_FREQ_BASE
, false, vNULL
,
1557 for (e
= master_clone
->callees
; e
; e
= e
->next_callee
)
1558 if (!e
->inline_failed
)
1559 clone_inlined_nodes (e
, true, false, NULL
, CGRAPH_FREQ_BASE
);
1560 curr
->redirect_callee (master_clone
);
1561 reset_edge_growth_cache (curr
);
1564 inline_call (curr
, false, new_edges
, &overall_size
, true);
1565 lookup_recursive_calls (node
, curr
->callee
, &heap
);
1569 if (!heap
.empty () && dump_file
)
1570 fprintf (dump_file
, " Recursive inlining growth limit met.\n");
1577 "\n Inlined %i times, "
1578 "body grown from size %i to %i, time %i to %i\n", n
,
1579 inline_summaries
->get (master_clone
)->size
, inline_summaries
->get (node
)->size
,
1580 inline_summaries
->get (master_clone
)->time
, inline_summaries
->get (node
)->time
);
1582 /* Remove master clone we used for inlining. We rely that clones inlined
1583 into master clone gets queued just before master clone so we don't
1585 for (node
= symtab
->first_function (); node
!= master_clone
;
1588 next
= symtab
->next_function (node
);
1589 if (node
->global
.inlined_to
== master_clone
)
1592 master_clone
->remove ();
1597 /* Given whole compilation unit estimate of INSNS, compute how large we can
1598 allow the unit to grow. */
1601 compute_max_insns (int insns
)
1603 int max_insns
= insns
;
1604 if (max_insns
< PARAM_VALUE (PARAM_LARGE_UNIT_INSNS
))
1605 max_insns
= PARAM_VALUE (PARAM_LARGE_UNIT_INSNS
);
1607 return ((int64_t) max_insns
1608 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH
)) / 100);
1612 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1615 add_new_edges_to_heap (edge_heap_t
*heap
, vec
<cgraph_edge
*> new_edges
)
1617 while (new_edges
.length () > 0)
1619 struct cgraph_edge
*edge
= new_edges
.pop ();
1621 gcc_assert (!edge
->aux
);
1622 if (edge
->inline_failed
1623 && can_inline_edge_p (edge
, true)
1624 && want_inline_small_function_p (edge
, true))
1625 edge
->aux
= heap
->insert (edge_badness (edge
, false), edge
);
1629 /* Remove EDGE from the fibheap. */
1632 heap_edge_removal_hook (struct cgraph_edge
*e
, void *data
)
1636 ((edge_heap_t
*)data
)->delete_node ((edge_heap_node_t
*)e
->aux
);
1641 /* Return true if speculation of edge E seems useful.
1642 If ANTICIPATE_INLINING is true, be conservative and hope that E
1646 speculation_useful_p (struct cgraph_edge
*e
, bool anticipate_inlining
)
1648 enum availability avail
;
1649 struct cgraph_node
*target
= e
->callee
->ultimate_alias_target (&avail
);
1650 struct cgraph_edge
*direct
, *indirect
;
1651 struct ipa_ref
*ref
;
1653 gcc_assert (e
->speculative
&& !e
->indirect_unknown_callee
);
1655 if (!e
->maybe_hot_p ())
1658 /* See if IP optimizations found something potentially useful about the
1659 function. For now we look only for CONST/PURE flags. Almost everything
1660 else we propagate is useless. */
1661 if (avail
>= AVAIL_AVAILABLE
)
1663 int ecf_flags
= flags_from_decl_or_type (target
->decl
);
1664 if (ecf_flags
& ECF_CONST
)
1666 e
->speculative_call_info (direct
, indirect
, ref
);
1667 if (!(indirect
->indirect_info
->ecf_flags
& ECF_CONST
))
1670 else if (ecf_flags
& ECF_PURE
)
1672 e
->speculative_call_info (direct
, indirect
, ref
);
1673 if (!(indirect
->indirect_info
->ecf_flags
& ECF_PURE
))
1677 /* If we did not managed to inline the function nor redirect
1678 to an ipa-cp clone (that are seen by having local flag set),
1679 it is probably pointless to inline it unless hardware is missing
1680 indirect call predictor. */
1681 if (!anticipate_inlining
&& e
->inline_failed
&& !target
->local
.local
)
1683 /* For overwritable targets there is not much to do. */
1684 if (e
->inline_failed
&& !can_inline_edge_p (e
, false, true))
1686 /* OK, speculation seems interesting. */
1690 /* We know that EDGE is not going to be inlined.
1691 See if we can remove speculation. */
1694 resolve_noninline_speculation (edge_heap_t
*edge_heap
, struct cgraph_edge
*edge
)
1696 if (edge
->speculative
&& !speculation_useful_p (edge
, false))
1698 struct cgraph_node
*node
= edge
->caller
;
1699 struct cgraph_node
*where
= node
->global
.inlined_to
1700 ? node
->global
.inlined_to
: node
;
1701 bitmap updated_nodes
= BITMAP_ALLOC (NULL
);
1703 spec_rem
+= edge
->count
;
1704 edge
->resolve_speculation ();
1705 reset_edge_caches (where
);
1706 inline_update_overall_summary (where
);
1707 update_caller_keys (edge_heap
, where
,
1708 updated_nodes
, NULL
);
1709 update_callee_keys (edge_heap
, where
,
1711 BITMAP_FREE (updated_nodes
);
1715 /* Return true if NODE should be accounted for overall size estimate.
1716 Skip all nodes optimized for size so we can measure the growth of hot
1717 part of program no matter of the padding. */
1720 inline_account_function_p (struct cgraph_node
*node
)
1722 return (!DECL_EXTERNAL (node
->decl
)
1723 && !opt_for_fn (node
->decl
, optimize_size
)
1724 && node
->frequency
!= NODE_FREQUENCY_UNLIKELY_EXECUTED
);
1727 /* Count number of callers of NODE and store it into DATA (that
1728 points to int. Worker for cgraph_for_node_and_aliases. */
1731 sum_callers (struct cgraph_node
*node
, void *data
)
1733 struct cgraph_edge
*e
;
1734 int *num_calls
= (int *)data
;
1736 for (e
= node
->callers
; e
; e
= e
->next_caller
)
1741 /* We use greedy algorithm for inlining of small functions:
1742 All inline candidates are put into prioritized heap ordered in
1745 The inlining of small functions is bounded by unit growth parameters. */
1748 inline_small_functions (void)
1750 struct cgraph_node
*node
;
1751 struct cgraph_edge
*edge
;
1752 edge_heap_t
edge_heap (sreal::min ());
1753 bitmap updated_nodes
= BITMAP_ALLOC (NULL
);
1754 int min_size
, max_size
;
1755 auto_vec
<cgraph_edge
*> new_indirect_edges
;
1756 int initial_size
= 0;
1757 struct cgraph_node
**order
= XCNEWVEC (cgraph_node
*, symtab
->cgraph_count
);
1758 struct cgraph_edge_hook_list
*edge_removal_hook_holder
;
1759 new_indirect_edges
.create (8);
1761 edge_removal_hook_holder
1762 = symtab
->add_edge_removal_hook (&heap_edge_removal_hook
, &edge_heap
);
1764 /* Compute overall unit size and other global parameters used by badness
1768 ipa_reduced_postorder (order
, true, true, NULL
);
1771 FOR_EACH_DEFINED_FUNCTION (node
)
1772 if (!node
->global
.inlined_to
)
1774 if (!node
->alias
&& node
->analyzed
1775 && (node
->has_gimple_body_p () || node
->thunk
.thunk_p
))
1777 struct inline_summary
*info
= inline_summaries
->get (node
);
1778 struct ipa_dfs_info
*dfs
= (struct ipa_dfs_info
*) node
->aux
;
1780 /* Do not account external functions, they will be optimized out
1781 if not inlined. Also only count the non-cold portion of program. */
1782 if (inline_account_function_p (node
))
1783 initial_size
+= info
->size
;
1784 info
->growth
= estimate_growth (node
);
1787 node
->call_for_symbol_and_aliases (sum_callers
, &num_calls
,
1790 info
->single_caller
= true;
1791 if (dfs
&& dfs
->next_cycle
)
1793 struct cgraph_node
*n2
;
1794 int id
= dfs
->scc_no
+ 1;
1796 n2
= ((struct ipa_dfs_info
*) node
->aux
)->next_cycle
)
1798 struct inline_summary
*info2
= inline_summaries
->get (n2
);
1806 for (edge
= node
->callers
; edge
; edge
= edge
->next_caller
)
1807 if (max_count
< edge
->count
)
1808 max_count
= edge
->count
;
1810 ipa_free_postorder_info ();
1811 initialize_growth_caches ();
1815 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1818 overall_size
= initial_size
;
1819 max_size
= compute_max_insns (overall_size
);
1820 min_size
= overall_size
;
1822 /* Populate the heap with all edges we might inline. */
1824 FOR_EACH_DEFINED_FUNCTION (node
)
1826 bool update
= false;
1827 struct cgraph_edge
*next
= NULL
;
1828 bool has_speculative
= false;
1831 fprintf (dump_file
, "Enqueueing calls in %s/%i.\n",
1832 node
->name (), node
->order
);
1834 for (edge
= node
->callees
; edge
; edge
= next
)
1836 next
= edge
->next_callee
;
1837 if (edge
->inline_failed
1839 && can_inline_edge_p (edge
, true)
1840 && want_inline_small_function_p (edge
, true)
1841 && edge
->inline_failed
)
1843 gcc_assert (!edge
->aux
);
1844 update_edge_key (&edge_heap
, edge
);
1846 if (edge
->speculative
)
1847 has_speculative
= true;
1849 if (has_speculative
)
1850 for (edge
= node
->callees
; edge
; edge
= next
)
1851 if (edge
->speculative
&& !speculation_useful_p (edge
,
1854 edge
->resolve_speculation ();
1859 struct cgraph_node
*where
= node
->global
.inlined_to
1860 ? node
->global
.inlined_to
: node
;
1861 inline_update_overall_summary (where
);
1862 reset_edge_caches (where
);
1863 update_caller_keys (&edge_heap
, where
,
1864 updated_nodes
, NULL
);
1865 update_callee_keys (&edge_heap
, where
,
1867 bitmap_clear (updated_nodes
);
1871 gcc_assert (in_lto_p
1873 || (profile_info
&& flag_branch_probabilities
));
1875 while (!edge_heap
.empty ())
1877 int old_size
= overall_size
;
1878 struct cgraph_node
*where
, *callee
;
1879 sreal badness
= edge_heap
.min_key ();
1880 sreal current_badness
;
1883 edge
= edge_heap
.extract_min ();
1884 gcc_assert (edge
->aux
);
1886 if (!edge
->inline_failed
|| !edge
->callee
->analyzed
)
1889 #ifdef ENABLE_CHECKING
1890 /* Be sure that caches are maintained consistent. */
1891 sreal cached_badness
= edge_badness (edge
, false);
1893 int old_size_est
= estimate_edge_size (edge
);
1894 int old_time_est
= estimate_edge_time (edge
);
1895 int old_hints_est
= estimate_edge_hints (edge
);
1897 reset_edge_growth_cache (edge
);
1898 gcc_assert (old_size_est
== estimate_edge_size (edge
));
1899 gcc_assert (old_time_est
== estimate_edge_time (edge
));
1902 gcc_assert (old_hints_est == estimate_edge_hints (edge));
1904 fails with profile feedback because some hints depends on
1905 maybe_hot_edge_p predicate and because callee gets inlined to other
1906 calls, the edge may become cold.
1907 This ought to be fixed by computing relative probabilities
1908 for given invocation but that will be better done once whole
1909 code is converted to sreals. Disable for now and revert to "wrong"
1910 value so enable/disable checking paths agree. */
1911 edge_growth_cache
[edge
->uid
].hints
= old_hints_est
+ 1;
1913 /* When updating the edge costs, we only decrease badness in the keys.
1914 Increases of badness are handled lazilly; when we see key with out
1915 of date value on it, we re-insert it now. */
1916 current_badness
= edge_badness (edge
, false);
1917 /* Disable checking for profile because roundoff errors may cause slight
1918 deviations in the order. */
1919 gcc_assert (max_count
|| cached_badness
== current_badness
);
1920 gcc_assert (current_badness
>= badness
);
1922 current_badness
= edge_badness (edge
, false);
1924 if (current_badness
!= badness
)
1926 if (edge_heap
.min () && current_badness
> edge_heap
.min_key ())
1928 edge
->aux
= edge_heap
.insert (current_badness
, edge
);
1932 badness
= current_badness
;
1935 if (!can_inline_edge_p (edge
, true))
1937 resolve_noninline_speculation (&edge_heap
, edge
);
1941 callee
= edge
->callee
->ultimate_alias_target ();
1942 growth
= estimate_edge_growth (edge
);
1946 "\nConsidering %s/%i with %i size\n",
1947 callee
->name (), callee
->order
,
1948 inline_summaries
->get (callee
)->size
);
1950 " to be inlined into %s/%i in %s:%i\n"
1951 " Estimated badness is %f, frequency %.2f.\n",
1952 edge
->caller
->name (), edge
->caller
->order
,
1954 && (LOCATION_LOCUS (gimple_location ((const_gimple
)
1956 > BUILTINS_LOCATION
)
1957 ? gimple_filename ((const_gimple
) edge
->call_stmt
)
1960 ? gimple_lineno ((const_gimple
) edge
->call_stmt
)
1962 badness
.to_double (),
1963 edge
->frequency
/ (double)CGRAPH_FREQ_BASE
);
1965 fprintf (dump_file
," Called %" PRId64
"x\n",
1967 if (dump_flags
& TDF_DETAILS
)
1968 edge_badness (edge
, true);
1971 if (overall_size
+ growth
> max_size
1972 && !DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
1974 edge
->inline_failed
= CIF_INLINE_UNIT_GROWTH_LIMIT
;
1975 report_inline_failed_reason (edge
);
1976 resolve_noninline_speculation (&edge_heap
, edge
);
1980 if (!want_inline_small_function_p (edge
, true))
1982 resolve_noninline_speculation (&edge_heap
, edge
);
1986 /* Heuristics for inlining small functions work poorly for
1987 recursive calls where we do effects similar to loop unrolling.
1988 When inlining such edge seems profitable, leave decision on
1989 specific inliner. */
1990 if (edge
->recursive_p ())
1992 where
= edge
->caller
;
1993 if (where
->global
.inlined_to
)
1994 where
= where
->global
.inlined_to
;
1995 if (!recursive_inlining (edge
,
1996 opt_for_fn (edge
->caller
->decl
,
1997 flag_indirect_inlining
)
1998 ? &new_indirect_edges
: NULL
))
2000 edge
->inline_failed
= CIF_RECURSIVE_INLINING
;
2001 resolve_noninline_speculation (&edge_heap
, edge
);
2004 reset_edge_caches (where
);
2005 /* Recursive inliner inlines all recursive calls of the function
2006 at once. Consequently we need to update all callee keys. */
2007 if (opt_for_fn (edge
->caller
->decl
, flag_indirect_inlining
))
2008 add_new_edges_to_heap (&edge_heap
, new_indirect_edges
);
2009 update_callee_keys (&edge_heap
, where
, updated_nodes
);
2010 bitmap_clear (updated_nodes
);
2014 struct cgraph_node
*outer_node
= NULL
;
2017 /* Consider the case where self recursive function A is inlined
2018 into B. This is desired optimization in some cases, since it
2019 leads to effect similar of loop peeling and we might completely
2020 optimize out the recursive call. However we must be extra
2023 where
= edge
->caller
;
2024 while (where
->global
.inlined_to
)
2026 if (where
->decl
== callee
->decl
)
2027 outer_node
= where
, depth
++;
2028 where
= where
->callers
->caller
;
2031 && !want_inline_self_recursive_call_p (edge
, outer_node
,
2035 = (DECL_DISREGARD_INLINE_LIMITS (edge
->callee
->decl
)
2036 ? CIF_RECURSIVE_INLINING
: CIF_UNSPECIFIED
);
2037 resolve_noninline_speculation (&edge_heap
, edge
);
2040 else if (depth
&& dump_file
)
2041 fprintf (dump_file
, " Peeling recursion with depth %i\n", depth
);
2043 gcc_checking_assert (!callee
->global
.inlined_to
);
2044 inline_call (edge
, true, &new_indirect_edges
, &overall_size
, true);
2045 add_new_edges_to_heap (&edge_heap
, new_indirect_edges
);
2047 reset_edge_caches (edge
->callee
->function_symbol ());
2049 update_callee_keys (&edge_heap
, where
, updated_nodes
);
2051 where
= edge
->caller
;
2052 if (where
->global
.inlined_to
)
2053 where
= where
->global
.inlined_to
;
2055 /* Our profitability metric can depend on local properties
2056 such as number of inlinable calls and size of the function body.
2057 After inlining these properties might change for the function we
2058 inlined into (since it's body size changed) and for the functions
2059 called by function we inlined (since number of it inlinable callers
2061 update_caller_keys (&edge_heap
, where
, updated_nodes
, NULL
);
2062 /* Offline copy count has possibly changed, recompute if profile is
2066 struct cgraph_node
*n
= cgraph_node::get (edge
->callee
->decl
);
2067 if (n
!= edge
->callee
&& n
->analyzed
)
2068 update_callee_keys (&edge_heap
, n
, updated_nodes
);
2070 bitmap_clear (updated_nodes
);
2075 " Inlined into %s which now has time %i and size %i,"
2076 "net change of %+i.\n",
2077 edge
->caller
->name (),
2078 inline_summaries
->get (edge
->caller
)->time
,
2079 inline_summaries
->get (edge
->caller
)->size
,
2080 overall_size
- old_size
);
2082 if (min_size
> overall_size
)
2084 min_size
= overall_size
;
2085 max_size
= compute_max_insns (min_size
);
2088 fprintf (dump_file
, "New minimal size reached: %i\n", min_size
);
2092 free_growth_caches ();
2095 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2096 initial_size
, overall_size
,
2097 initial_size
? overall_size
* 100 / (initial_size
) - 100: 0);
2098 BITMAP_FREE (updated_nodes
);
2099 symtab
->remove_edge_removal_hook (edge_removal_hook_holder
);
2102 /* Flatten NODE. Performed both during early inlining and
2103 at IPA inlining time. */
2106 flatten_function (struct cgraph_node
*node
, bool early
)
2108 struct cgraph_edge
*e
;
2110 /* We shouldn't be called recursively when we are being processed. */
2111 gcc_assert (node
->aux
== NULL
);
2113 node
->aux
= (void *) node
;
2115 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2117 struct cgraph_node
*orig_callee
;
2118 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2120 /* We've hit cycle? It is time to give up. */
2125 "Not inlining %s into %s to avoid cycle.\n",
2126 xstrdup_for_dump (callee
->name ()),
2127 xstrdup_for_dump (e
->caller
->name ()));
2128 e
->inline_failed
= CIF_RECURSIVE_INLINING
;
2132 /* When the edge is already inlined, we just need to recurse into
2133 it in order to fully flatten the leaves. */
2134 if (!e
->inline_failed
)
2136 flatten_function (callee
, early
);
2140 /* Flatten attribute needs to be processed during late inlining. For
2141 extra code quality we however do flattening during early optimization,
2144 ? !can_inline_edge_p (e
, true)
2145 : !can_early_inline_edge_p (e
))
2148 if (e
->recursive_p ())
2151 fprintf (dump_file
, "Not inlining: recursive call.\n");
2155 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node
->decl
))
2156 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee
->decl
)))
2159 fprintf (dump_file
, "Not inlining: SSA form does not match.\n");
2163 /* Inline the edge and flatten the inline clone. Avoid
2164 recursing through the original node if the node was cloned. */
2166 fprintf (dump_file
, " Inlining %s into %s.\n",
2167 xstrdup_for_dump (callee
->name ()),
2168 xstrdup_for_dump (e
->caller
->name ()));
2169 orig_callee
= callee
;
2170 inline_call (e
, true, NULL
, NULL
, false);
2171 if (e
->callee
!= orig_callee
)
2172 orig_callee
->aux
= (void *) node
;
2173 flatten_function (e
->callee
, early
);
2174 if (e
->callee
!= orig_callee
)
2175 orig_callee
->aux
= NULL
;
2179 if (!node
->global
.inlined_to
)
2180 inline_update_overall_summary (node
);
2183 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2184 DATA points to number of calls originally found so we avoid infinite
2188 inline_to_all_callers (struct cgraph_node
*node
, void *data
)
2190 int *num_calls
= (int *)data
;
2191 bool callee_removed
= false;
2193 while (node
->callers
&& !node
->global
.inlined_to
)
2195 struct cgraph_node
*caller
= node
->callers
->caller
;
2197 if (!can_inline_edge_p (node
->callers
, true)
2198 || node
->callers
->recursive_p ())
2201 fprintf (dump_file
, "Uninlinable call found; giving up.\n");
2209 "\nInlining %s size %i.\n",
2211 inline_summaries
->get (node
)->size
);
2213 " Called once from %s %i insns.\n",
2214 node
->callers
->caller
->name (),
2215 inline_summaries
->get (node
->callers
->caller
)->size
);
2218 inline_call (node
->callers
, true, NULL
, NULL
, true, &callee_removed
);
2221 " Inlined into %s which now has %i size\n",
2223 inline_summaries
->get (caller
)->size
);
2224 if (!(*num_calls
)--)
2227 fprintf (dump_file
, "New calls found; giving up.\n");
2228 return callee_removed
;
2236 /* Output overall time estimate. */
2238 dump_overall_stats (void)
2240 int64_t sum_weighted
= 0, sum
= 0;
2241 struct cgraph_node
*node
;
2243 FOR_EACH_DEFINED_FUNCTION (node
)
2244 if (!node
->global
.inlined_to
2247 int time
= inline_summaries
->get (node
)->time
;
2249 sum_weighted
+= time
* node
->count
;
2251 fprintf (dump_file
, "Overall time estimate: "
2252 "%" PRId64
" weighted by profile: "
2253 "%" PRId64
"\n", sum
, sum_weighted
);
2256 /* Output some useful stats about inlining. */
2259 dump_inline_stats (void)
2261 int64_t inlined_cnt
= 0, inlined_indir_cnt
= 0;
2262 int64_t inlined_virt_cnt
= 0, inlined_virt_indir_cnt
= 0;
2263 int64_t noninlined_cnt
= 0, noninlined_indir_cnt
= 0;
2264 int64_t noninlined_virt_cnt
= 0, noninlined_virt_indir_cnt
= 0;
2265 int64_t inlined_speculative
= 0, inlined_speculative_ply
= 0;
2266 int64_t indirect_poly_cnt
= 0, indirect_cnt
= 0;
2267 int64_t reason
[CIF_N_REASONS
][3];
2269 struct cgraph_node
*node
;
2271 memset (reason
, 0, sizeof (reason
));
2272 FOR_EACH_DEFINED_FUNCTION (node
)
2274 struct cgraph_edge
*e
;
2275 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2277 if (e
->inline_failed
)
2279 reason
[(int) e
->inline_failed
][0] += e
->count
;
2280 reason
[(int) e
->inline_failed
][1] += e
->frequency
;
2281 reason
[(int) e
->inline_failed
][2] ++;
2282 if (DECL_VIRTUAL_P (e
->callee
->decl
))
2284 if (e
->indirect_inlining_edge
)
2285 noninlined_virt_indir_cnt
+= e
->count
;
2287 noninlined_virt_cnt
+= e
->count
;
2291 if (e
->indirect_inlining_edge
)
2292 noninlined_indir_cnt
+= e
->count
;
2294 noninlined_cnt
+= e
->count
;
2301 if (DECL_VIRTUAL_P (e
->callee
->decl
))
2302 inlined_speculative_ply
+= e
->count
;
2304 inlined_speculative
+= e
->count
;
2306 else if (DECL_VIRTUAL_P (e
->callee
->decl
))
2308 if (e
->indirect_inlining_edge
)
2309 inlined_virt_indir_cnt
+= e
->count
;
2311 inlined_virt_cnt
+= e
->count
;
2315 if (e
->indirect_inlining_edge
)
2316 inlined_indir_cnt
+= e
->count
;
2318 inlined_cnt
+= e
->count
;
2322 for (e
= node
->indirect_calls
; e
; e
= e
->next_callee
)
2323 if (e
->indirect_info
->polymorphic
)
2324 indirect_poly_cnt
+= e
->count
;
2326 indirect_cnt
+= e
->count
;
2331 "Inlined %" PRId64
" + speculative "
2332 "%" PRId64
" + speculative polymorphic "
2333 "%" PRId64
" + previously indirect "
2334 "%" PRId64
" + virtual "
2335 "%" PRId64
" + virtual and previously indirect "
2336 "%" PRId64
"\n" "Not inlined "
2337 "%" PRId64
" + previously indirect "
2338 "%" PRId64
" + virtual "
2339 "%" PRId64
" + virtual and previously indirect "
2340 "%" PRId64
" + stil indirect "
2341 "%" PRId64
" + still indirect polymorphic "
2342 "%" PRId64
"\n", inlined_cnt
,
2343 inlined_speculative
, inlined_speculative_ply
,
2344 inlined_indir_cnt
, inlined_virt_cnt
, inlined_virt_indir_cnt
,
2345 noninlined_cnt
, noninlined_indir_cnt
, noninlined_virt_cnt
,
2346 noninlined_virt_indir_cnt
, indirect_cnt
, indirect_poly_cnt
);
2348 "Removed speculations %" PRId64
"\n",
2351 dump_overall_stats ();
2352 fprintf (dump_file
, "\nWhy inlining failed?\n");
2353 for (i
= 0; i
< CIF_N_REASONS
; i
++)
2355 fprintf (dump_file
, "%-50s: %8i calls, %8i freq, %" PRId64
" count\n",
2356 cgraph_inline_failed_string ((cgraph_inline_failed_t
) i
),
2357 (int) reason
[i
][2], (int) reason
[i
][1], reason
[i
][0]);
2360 /* Decide on the inlining. We do so in the topological order to avoid
2361 expenses on updating data structures. */
2366 struct cgraph_node
*node
;
2368 struct cgraph_node
**order
;
2371 bool remove_functions
= false;
2376 cgraph_freq_base_rec
= (sreal
) 1 / (sreal
) CGRAPH_FREQ_BASE
;
2377 percent_rec
= (sreal
) 1 / (sreal
) 100;
2379 order
= XCNEWVEC (struct cgraph_node
*, symtab
->cgraph_count
);
2381 if (in_lto_p
&& optimize
)
2382 ipa_update_after_lto_read ();
2385 dump_inline_summaries (dump_file
);
2387 nnodes
= ipa_reverse_postorder (order
);
2389 FOR_EACH_FUNCTION (node
)
2393 /* Recompute the default reasons for inlining because they may have
2394 changed during merging. */
2397 for (cgraph_edge
*e
= node
->callees
; e
; e
= e
->next_callee
)
2399 gcc_assert (e
->inline_failed
);
2400 initialize_inline_failed (e
);
2402 for (cgraph_edge
*e
= node
->indirect_calls
; e
; e
= e
->next_callee
)
2403 initialize_inline_failed (e
);
2408 fprintf (dump_file
, "\nFlattening functions:\n");
2410 /* In the first pass handle functions to be flattened. Do this with
2411 a priority so none of our later choices will make this impossible. */
2412 for (i
= nnodes
- 1; i
>= 0; i
--)
2416 /* Handle nodes to be flattened.
2417 Ideally when processing callees we stop inlining at the
2418 entry of cycles, possibly cloning that entry point and
2419 try to flatten itself turning it into a self-recursive
2421 if (lookup_attribute ("flatten",
2422 DECL_ATTRIBUTES (node
->decl
)) != NULL
)
2426 "Flattening %s\n", node
->name ());
2427 flatten_function (node
, false);
2431 dump_overall_stats ();
2433 inline_small_functions ();
2435 gcc_assert (symtab
->state
== IPA_SSA
);
2436 symtab
->state
= IPA_SSA_AFTER_INLINING
;
2437 /* Do first after-inlining removal. We want to remove all "stale" extern
2438 inline functions and virtual functions so we really know what is called
2440 symtab
->remove_unreachable_nodes (dump_file
);
2443 /* Inline functions with a property that after inlining into all callers the
2444 code size will shrink because the out-of-line copy is eliminated.
2445 We do this regardless on the callee size as long as function growth limits
2449 "\nDeciding on functions to be inlined into all callers and "
2450 "removing useless speculations:\n");
2452 /* Inlining one function called once has good chance of preventing
2453 inlining other function into the same callee. Ideally we should
2454 work in priority order, but probably inlining hot functions first
2455 is good cut without the extra pain of maintaining the queue.
2457 ??? this is not really fitting the bill perfectly: inlining function
2458 into callee often leads to better optimization of callee due to
2459 increased context for optimization.
2460 For example if main() function calls a function that outputs help
2461 and then function that does the main optmization, we should inline
2462 the second with priority even if both calls are cold by themselves.
2464 We probably want to implement new predicate replacing our use of
2465 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2467 for (cold
= 0; cold
<= 1; cold
++)
2469 FOR_EACH_DEFINED_FUNCTION (node
)
2471 struct cgraph_edge
*edge
, *next
;
2474 for (edge
= node
->callees
; edge
; edge
= next
)
2476 next
= edge
->next_callee
;
2477 if (edge
->speculative
&& !speculation_useful_p (edge
, false))
2479 edge
->resolve_speculation ();
2480 spec_rem
+= edge
->count
;
2482 remove_functions
= true;
2487 struct cgraph_node
*where
= node
->global
.inlined_to
2488 ? node
->global
.inlined_to
: node
;
2489 reset_edge_caches (where
);
2490 inline_update_overall_summary (where
);
2492 if (want_inline_function_to_all_callers_p (node
, cold
))
2495 node
->call_for_symbol_and_aliases (sum_callers
, &num_calls
,
2497 while (node
->call_for_symbol_and_aliases
2498 (inline_to_all_callers
, &num_calls
, true))
2500 remove_functions
= true;
2505 /* Free ipa-prop structures if they are no longer needed. */
2507 ipa_free_all_structures_after_iinln ();
2512 "\nInlined %i calls, eliminated %i functions\n\n",
2513 ncalls_inlined
, nfunctions_inlined
);
2514 dump_inline_stats ();
2518 dump_inline_summaries (dump_file
);
2519 /* In WPA we use inline summaries for partitioning process. */
2521 inline_free_summary ();
2522 return remove_functions
? TODO_remove_functions
: 0;
2525 /* Inline always-inline function calls in NODE. */
2528 inline_always_inline_functions (struct cgraph_node
*node
)
2530 struct cgraph_edge
*e
;
2531 bool inlined
= false;
2533 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2535 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2536 if (!DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
2539 if (e
->recursive_p ())
2542 fprintf (dump_file
, " Not inlining recursive call to %s.\n",
2543 e
->callee
->name ());
2544 e
->inline_failed
= CIF_RECURSIVE_INLINING
;
2548 if (!can_early_inline_edge_p (e
))
2550 /* Set inlined to true if the callee is marked "always_inline" but
2551 is not inlinable. This will allow flagging an error later in
2552 expand_call_inline in tree-inline.c. */
2553 if (lookup_attribute ("always_inline",
2554 DECL_ATTRIBUTES (callee
->decl
)) != NULL
)
2560 fprintf (dump_file
, " Inlining %s into %s (always_inline).\n",
2561 xstrdup_for_dump (e
->callee
->name ()),
2562 xstrdup_for_dump (e
->caller
->name ()));
2563 inline_call (e
, true, NULL
, NULL
, false);
2567 inline_update_overall_summary (node
);
2572 /* Decide on the inlining. We do so in the topological order to avoid
2573 expenses on updating data structures. */
2576 early_inline_small_functions (struct cgraph_node
*node
)
2578 struct cgraph_edge
*e
;
2579 bool inlined
= false;
2581 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2583 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2584 if (!inline_summaries
->get (callee
)->inlinable
2585 || !e
->inline_failed
)
2588 /* Do not consider functions not declared inline. */
2589 if (!DECL_DECLARED_INLINE_P (callee
->decl
)
2590 && !opt_for_fn (node
->decl
, flag_inline_small_functions
)
2591 && !opt_for_fn (node
->decl
, flag_inline_functions
))
2595 fprintf (dump_file
, "Considering inline candidate %s.\n",
2598 if (!can_early_inline_edge_p (e
))
2601 if (e
->recursive_p ())
2604 fprintf (dump_file
, " Not inlining: recursive call.\n");
2608 if (!want_early_inline_function_p (e
))
2612 fprintf (dump_file
, " Inlining %s into %s.\n",
2613 xstrdup_for_dump (callee
->name ()),
2614 xstrdup_for_dump (e
->caller
->name ()));
2615 inline_call (e
, true, NULL
, NULL
, true);
2623 early_inliner (function
*fun
)
2625 struct cgraph_node
*node
= cgraph_node::get (current_function_decl
);
2626 struct cgraph_edge
*edge
;
2627 unsigned int todo
= 0;
2629 bool inlined
= false;
2634 /* Do nothing if datastructures for ipa-inliner are already computed. This
2635 happens when some pass decides to construct new function and
2636 cgraph_add_new_function calls lowering passes and early optimization on
2637 it. This may confuse ourself when early inliner decide to inline call to
2638 function clone, because function clones don't have parameter list in
2639 ipa-prop matching their signature. */
2640 if (ipa_node_params_sum
)
2643 #ifdef ENABLE_CHECKING
2646 node
->remove_all_references ();
2648 /* Rebuild this reference because it dosn't depend on
2649 function's body and it's required to pass cgraph_node
2651 if (node
->instrumented_version
2652 && !node
->instrumentation_clone
)
2653 node
->create_reference (node
->instrumented_version
, IPA_REF_CHKP
, NULL
);
2655 /* Even when not optimizing or not inlining inline always-inline
2657 inlined
= inline_always_inline_functions (node
);
2661 || !flag_early_inlining
2662 /* Never inline regular functions into always-inline functions
2663 during incremental inlining. This sucks as functions calling
2664 always inline functions will get less optimized, but at the
2665 same time inlining of functions calling always inline
2666 function into an always inline function might introduce
2667 cycles of edges to be always inlined in the callgraph.
2669 We might want to be smarter and just avoid this type of inlining. */
2670 || (DECL_DISREGARD_INLINE_LIMITS (node
->decl
)
2671 && lookup_attribute ("always_inline",
2672 DECL_ATTRIBUTES (node
->decl
))))
2674 else if (lookup_attribute ("flatten",
2675 DECL_ATTRIBUTES (node
->decl
)) != NULL
)
2677 /* When the function is marked to be flattened, recursively inline
2681 "Flattening %s\n", node
->name ());
2682 flatten_function (node
, true);
2687 /* If some always_inline functions was inlined, apply the changes.
2688 This way we will not account always inline into growth limits and
2689 moreover we will inline calls from always inlines that we skipped
2690 previously becuase of conditional above. */
2693 timevar_push (TV_INTEGRATION
);
2694 todo
|= optimize_inline_calls (current_function_decl
);
2695 /* optimize_inline_calls call above might have introduced new
2696 statements that don't have inline parameters computed. */
2697 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
2699 if (inline_edge_summary_vec
.length () > (unsigned) edge
->uid
)
2701 struct inline_edge_summary
*es
= inline_edge_summary (edge
);
2703 = estimate_num_insns (edge
->call_stmt
, &eni_size_weights
);
2705 = estimate_num_insns (edge
->call_stmt
, &eni_time_weights
);
2708 inline_update_overall_summary (node
);
2710 timevar_pop (TV_INTEGRATION
);
2712 /* We iterate incremental inlining to get trivial cases of indirect
2714 while (iterations
< PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS
)
2715 && early_inline_small_functions (node
))
2717 timevar_push (TV_INTEGRATION
);
2718 todo
|= optimize_inline_calls (current_function_decl
);
2720 /* Technically we ought to recompute inline parameters so the new
2721 iteration of early inliner works as expected. We however have
2722 values approximately right and thus we only need to update edge
2723 info that might be cleared out for newly discovered edges. */
2724 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
2726 /* We have no summary for new bound store calls yet. */
2727 if (inline_edge_summary_vec
.length () > (unsigned)edge
->uid
)
2729 struct inline_edge_summary
*es
= inline_edge_summary (edge
);
2731 = estimate_num_insns (edge
->call_stmt
, &eni_size_weights
);
2733 = estimate_num_insns (edge
->call_stmt
, &eni_time_weights
);
2735 if (edge
->callee
->decl
2736 && !gimple_check_call_matching_types (
2737 edge
->call_stmt
, edge
->callee
->decl
, false))
2738 edge
->call_stmt_cannot_inline_p
= true;
2740 if (iterations
< PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS
) - 1)
2741 inline_update_overall_summary (node
);
2742 timevar_pop (TV_INTEGRATION
);
2747 fprintf (dump_file
, "Iterations: %i\n", iterations
);
2752 timevar_push (TV_INTEGRATION
);
2753 todo
|= optimize_inline_calls (current_function_decl
);
2754 timevar_pop (TV_INTEGRATION
);
2757 fun
->always_inline_functions_inlined
= true;
2762 /* Do inlining of small functions. Doing so early helps profiling and other
2763 passes to be somewhat more effective and avoids some code duplication in
2764 later real inlining pass for testcases with very many function calls. */
2768 const pass_data pass_data_early_inline
=
2770 GIMPLE_PASS
, /* type */
2771 "einline", /* name */
2772 OPTGROUP_INLINE
, /* optinfo_flags */
2773 TV_EARLY_INLINING
, /* tv_id */
2774 PROP_ssa
, /* properties_required */
2775 0, /* properties_provided */
2776 0, /* properties_destroyed */
2777 0, /* todo_flags_start */
2778 0, /* todo_flags_finish */
2781 class pass_early_inline
: public gimple_opt_pass
2784 pass_early_inline (gcc::context
*ctxt
)
2785 : gimple_opt_pass (pass_data_early_inline
, ctxt
)
2788 /* opt_pass methods: */
2789 virtual unsigned int execute (function
*);
2791 }; // class pass_early_inline
2794 pass_early_inline::execute (function
*fun
)
2796 return early_inliner (fun
);
2802 make_pass_early_inline (gcc::context
*ctxt
)
2804 return new pass_early_inline (ctxt
);
2809 const pass_data pass_data_ipa_inline
=
2811 IPA_PASS
, /* type */
2812 "inline", /* name */
2813 OPTGROUP_INLINE
, /* optinfo_flags */
2814 TV_IPA_INLINING
, /* tv_id */
2815 0, /* properties_required */
2816 0, /* properties_provided */
2817 0, /* properties_destroyed */
2818 0, /* todo_flags_start */
2819 ( TODO_dump_symtab
), /* todo_flags_finish */
2822 class pass_ipa_inline
: public ipa_opt_pass_d
2825 pass_ipa_inline (gcc::context
*ctxt
)
2826 : ipa_opt_pass_d (pass_data_ipa_inline
, ctxt
,
2827 inline_generate_summary
, /* generate_summary */
2828 inline_write_summary
, /* write_summary */
2829 inline_read_summary
, /* read_summary */
2830 NULL
, /* write_optimization_summary */
2831 NULL
, /* read_optimization_summary */
2832 NULL
, /* stmt_fixup */
2833 0, /* function_transform_todo_flags_start */
2834 inline_transform
, /* function_transform */
2835 NULL
) /* variable_transform */
2838 /* opt_pass methods: */
2839 virtual unsigned int execute (function
*) { return ipa_inline (); }
2841 }; // class pass_ipa_inline
2846 make_pass_ipa_inline (gcc::context
*ctxt
)
2848 return new pass_ipa_inline (ctxt
);