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 "double-int.h"
103 #include "wide-int.h"
106 #include "fold-const.h"
107 #include "trans-mem.h"
109 #include "tree-inline.h"
110 #include "langhooks.h"
112 #include "diagnostic.h"
113 #include "gimple-pretty-print.h"
116 #include "tree-pass.h"
117 #include "coverage.h"
122 #include "hard-reg-set.h"
124 #include "function.h"
125 #include "basic-block.h"
126 #include "tree-ssa-alias.h"
127 #include "internal-fn.h"
128 #include "gimple-expr.h"
131 #include "gimple-ssa.h"
132 #include "hash-map.h"
133 #include "plugin-api.h"
136 #include "alloc-pool.h"
137 #include "symbol-summary.h"
138 #include "ipa-prop.h"
141 #include "ipa-inline.h"
142 #include "ipa-utils.h"
144 #include "auto-profile.h"
145 #include "builtins.h"
146 #include "fibonacci_heap.h"
147 #include "lto-streamer.h"
149 typedef fibonacci_heap
<sreal
, cgraph_edge
> edge_heap_t
;
150 typedef fibonacci_node
<sreal
, cgraph_edge
> edge_heap_node_t
;
152 /* Statistics we collect about inlining algorithm. */
153 static int overall_size
;
154 static gcov_type max_count
;
155 static gcov_type spec_rem
;
157 /* Pre-computed constants 1/CGRAPH_FREQ_BASE and 1/100. */
158 static sreal cgraph_freq_base_rec
, percent_rec
;
160 /* Return false when inlining edge E would lead to violating
161 limits on function unit growth or stack usage growth.
163 The relative function body growth limit is present generally
164 to avoid problems with non-linear behavior of the compiler.
165 To allow inlining huge functions into tiny wrapper, the limit
166 is always based on the bigger of the two functions considered.
168 For stack growth limits we always base the growth in stack usage
169 of the callers. We want to prevent applications from segfaulting
170 on stack overflow when functions with huge stack frames gets
174 caller_growth_limits (struct cgraph_edge
*e
)
176 struct cgraph_node
*to
= e
->caller
;
177 struct cgraph_node
*what
= e
->callee
->ultimate_alias_target ();
180 HOST_WIDE_INT stack_size_limit
= 0, inlined_stack
;
181 inline_summary
*info
, *what_info
, *outer_info
= inline_summaries
->get (to
);
183 /* Look for function e->caller is inlined to. While doing
184 so work out the largest function body on the way. As
185 described above, we want to base our function growth
186 limits based on that. Not on the self size of the
187 outer function, not on the self size of inline code
188 we immediately inline to. This is the most relaxed
189 interpretation of the rule "do not grow large functions
190 too much in order to prevent compiler from exploding". */
193 info
= inline_summaries
->get (to
);
194 if (limit
< info
->self_size
)
195 limit
= info
->self_size
;
196 if (stack_size_limit
< info
->estimated_self_stack_size
)
197 stack_size_limit
= info
->estimated_self_stack_size
;
198 if (to
->global
.inlined_to
)
199 to
= to
->callers
->caller
;
204 what_info
= inline_summaries
->get (what
);
206 if (limit
< what_info
->self_size
)
207 limit
= what_info
->self_size
;
209 limit
+= limit
* PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH
) / 100;
211 /* Check the size after inlining against the function limits. But allow
212 the function to shrink if it went over the limits by forced inlining. */
213 newsize
= estimate_size_after_inlining (to
, e
);
214 if (newsize
>= info
->size
215 && newsize
> PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS
)
218 e
->inline_failed
= CIF_LARGE_FUNCTION_GROWTH_LIMIT
;
222 if (!what_info
->estimated_stack_size
)
225 /* FIXME: Stack size limit often prevents inlining in Fortran programs
226 due to large i/o datastructures used by the Fortran front-end.
227 We ought to ignore this limit when we know that the edge is executed
228 on every invocation of the caller (i.e. its call statement dominates
229 exit block). We do not track this information, yet. */
230 stack_size_limit
+= ((gcov_type
)stack_size_limit
231 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH
) / 100);
233 inlined_stack
= (outer_info
->stack_frame_offset
234 + outer_info
->estimated_self_stack_size
235 + what_info
->estimated_stack_size
);
236 /* Check new stack consumption with stack consumption at the place
238 if (inlined_stack
> stack_size_limit
239 /* If function already has large stack usage from sibling
240 inline call, we can inline, too.
241 This bit overoptimistically assume that we are good at stack
243 && inlined_stack
> info
->estimated_stack_size
244 && inlined_stack
> PARAM_VALUE (PARAM_LARGE_STACK_FRAME
))
246 e
->inline_failed
= CIF_LARGE_STACK_FRAME_GROWTH_LIMIT
;
252 /* Dump info about why inlining has failed. */
255 report_inline_failed_reason (struct cgraph_edge
*e
)
259 fprintf (dump_file
, " not inlinable: %s/%i -> %s/%i, %s\n",
260 xstrdup_for_dump (e
->caller
->name ()), e
->caller
->order
,
261 xstrdup_for_dump (e
->callee
->name ()), e
->callee
->order
,
262 cgraph_inline_failed_string (e
->inline_failed
));
263 if ((e
->inline_failed
== CIF_TARGET_OPTION_MISMATCH
264 || e
->inline_failed
== CIF_OPTIMIZATION_MISMATCH
)
265 && e
->caller
->lto_file_data
266 && e
->callee
->function_symbol ()->lto_file_data
)
268 fprintf (dump_file
, " LTO objects: %s, %s\n",
269 e
->caller
->lto_file_data
->file_name
,
270 e
->callee
->function_symbol ()->lto_file_data
->file_name
);
272 if (e
->inline_failed
== CIF_TARGET_OPTION_MISMATCH
)
273 cl_target_option_print_diff
274 (dump_file
, 2, target_opts_for_fn (e
->caller
->decl
),
275 target_opts_for_fn (e
->callee
->ultimate_alias_target ()->decl
));
276 if (e
->inline_failed
== CIF_OPTIMIZATION_MISMATCH
)
277 cl_optimization_print_diff
278 (dump_file
, 2, opts_for_fn (e
->caller
->decl
),
279 opts_for_fn (e
->callee
->ultimate_alias_target ()->decl
));
283 /* Decide whether sanitizer-related attributes allow inlining. */
286 sanitize_attrs_match_for_inline_p (const_tree caller
, const_tree callee
)
288 /* Don't care if sanitizer is disabled */
289 if (!(flag_sanitize
& SANITIZE_ADDRESS
))
292 if (!caller
|| !callee
)
295 return !!lookup_attribute ("no_sanitize_address",
296 DECL_ATTRIBUTES (caller
)) ==
297 !!lookup_attribute ("no_sanitize_address",
298 DECL_ATTRIBUTES (callee
));
301 /* Used for flags where it is safe to inline when caller's value is
302 grater than callee's. */
303 #define check_maybe_up(flag) \
304 (opts_for_fn (caller->decl)->x_##flag \
305 != opts_for_fn (callee->decl)->x_##flag \
307 || opts_for_fn (caller->decl)->x_##flag \
308 < opts_for_fn (callee->decl)->x_##flag))
309 /* Used for flags where it is safe to inline when caller's value is
310 smaller than callee's. */
311 #define check_maybe_down(flag) \
312 (opts_for_fn (caller->decl)->x_##flag \
313 != opts_for_fn (callee->decl)->x_##flag \
315 || opts_for_fn (caller->decl)->x_##flag \
316 > opts_for_fn (callee->decl)->x_##flag))
317 /* Used for flags where exact match is needed for correctness. */
318 #define check_match(flag) \
319 (opts_for_fn (caller->decl)->x_##flag \
320 != opts_for_fn (callee->decl)->x_##flag)
322 /* Decide if we can inline the edge and possibly update
323 inline_failed reason.
324 We check whether inlining is possible at all and whether
325 caller growth limits allow doing so.
327 if REPORT is true, output reason to the dump file.
329 if DISREGARD_LIMITS is true, ignore size limits.*/
332 can_inline_edge_p (struct cgraph_edge
*e
, bool report
,
333 bool disregard_limits
= false, bool early
= false)
335 gcc_checking_assert (e
->inline_failed
);
337 if (cgraph_inline_failed_type (e
->inline_failed
) == CIF_FINAL_ERROR
)
340 report_inline_failed_reason (e
);
344 bool inlinable
= true;
345 enum availability avail
;
346 cgraph_node
*callee
= e
->callee
->ultimate_alias_target (&avail
);
347 cgraph_node
*caller
= e
->caller
->global
.inlined_to
348 ? e
->caller
->global
.inlined_to
: e
->caller
;
349 tree caller_tree
= DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller
->decl
);
351 = callee
? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee
->decl
) : NULL
;
353 if (!callee
->definition
)
355 e
->inline_failed
= CIF_BODY_NOT_AVAILABLE
;
358 else if (callee
->calls_comdat_local
)
360 e
->inline_failed
= CIF_USES_COMDAT_LOCAL
;
363 else if (avail
<= AVAIL_INTERPOSABLE
)
365 e
->inline_failed
= CIF_OVERWRITABLE
;
368 else if (e
->call_stmt_cannot_inline_p
)
370 if (e
->inline_failed
!= CIF_FUNCTION_NOT_OPTIMIZED
)
371 e
->inline_failed
= CIF_MISMATCHED_ARGUMENTS
;
374 /* Don't inline if the functions have different EH personalities. */
375 else if (DECL_FUNCTION_PERSONALITY (caller
->decl
)
376 && DECL_FUNCTION_PERSONALITY (callee
->decl
)
377 && (DECL_FUNCTION_PERSONALITY (caller
->decl
)
378 != DECL_FUNCTION_PERSONALITY (callee
->decl
)))
380 e
->inline_failed
= CIF_EH_PERSONALITY
;
383 /* TM pure functions should not be inlined into non-TM_pure
385 else if (is_tm_pure (callee
->decl
) && !is_tm_pure (caller
->decl
))
387 e
->inline_failed
= CIF_UNSPECIFIED
;
390 /* Check compatibility of target optimization options. */
391 else if (!targetm
.target_option
.can_inline_p (caller
->decl
,
394 e
->inline_failed
= CIF_TARGET_OPTION_MISMATCH
;
397 else if (!inline_summaries
->get (callee
)->inlinable
)
399 e
->inline_failed
= CIF_FUNCTION_NOT_INLINABLE
;
402 else if (inline_summaries
->get (caller
)->contains_cilk_spawn
)
404 e
->inline_failed
= CIF_CILK_SPAWN
;
407 /* Don't inline a function with mismatched sanitization attributes. */
408 else if (!sanitize_attrs_match_for_inline_p (caller
->decl
, callee
->decl
))
410 e
->inline_failed
= CIF_ATTRIBUTE_MISMATCH
;
413 /* Check if caller growth allows the inlining. */
414 else if (!DECL_DISREGARD_INLINE_LIMITS (callee
->decl
)
416 && !lookup_attribute ("flatten",
417 DECL_ATTRIBUTES (caller
->decl
))
418 && !caller_growth_limits (e
))
420 /* Don't inline a function with a higher optimization level than the
421 caller. FIXME: this is really just tip of iceberg of handling
422 optimization attribute. */
423 else if (caller_tree
!= callee_tree
)
426 (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
)
427 && lookup_attribute ("always_inline",
428 DECL_ATTRIBUTES (callee
->decl
)));
430 /* Until GCC 4.9 we did not check the semantics alterning flags
431 bellow and inline across optimization boundry.
432 Enabling checks bellow breaks several packages by refusing
433 to inline library always_inline functions. See PR65873.
434 Disable the check for early inlining for now until better solution
436 if (always_inline
&& early
)
438 /* There are some options that change IL semantics which means
439 we cannot inline in these cases for correctness reason.
440 Not even for always_inline declared functions. */
441 /* Strictly speaking only when the callee contains signed integer
442 math where overflow is undefined. */
443 else if ((check_maybe_up (flag_strict_overflow
)
444 /* this flag is set by optimize. Allow inlining across
445 optimize boundary. */
446 && (!opt_for_fn (caller
->decl
, optimize
)
447 == !opt_for_fn (callee
->decl
, optimize
) || !always_inline
))
448 || check_match (flag_wrapv
)
449 || check_match (flag_trapv
)
450 /* Strictly speaking only when the callee uses FP math. */
451 || check_maybe_up (flag_rounding_math
)
452 || check_maybe_up (flag_trapping_math
)
453 || check_maybe_down (flag_unsafe_math_optimizations
)
454 || check_maybe_down (flag_finite_math_only
)
455 || check_maybe_up (flag_signaling_nans
)
456 || check_maybe_down (flag_cx_limited_range
)
457 || check_maybe_up (flag_signed_zeros
)
458 || check_maybe_down (flag_associative_math
)
459 || check_maybe_down (flag_reciprocal_math
)
460 /* We do not want to make code compiled with exceptions to be
461 brought into a non-EH function unless we know that the callee
463 This is tracked by DECL_FUNCTION_PERSONALITY. */
464 || (check_match (flag_non_call_exceptions
)
465 /* TODO: We also may allow bringing !flag_non_call_exceptions
466 to flag_non_call_exceptions function, but that may need
467 extra work in tree-inline to add the extra EH edges. */
468 && (!opt_for_fn (callee
->decl
, flag_non_call_exceptions
)
469 || DECL_FUNCTION_PERSONALITY (callee
->decl
)))
470 || (check_maybe_up (flag_exceptions
)
471 && DECL_FUNCTION_PERSONALITY (callee
->decl
))
472 /* Strictly speaking only when the callee contains function
473 calls that may end up setting errno. */
474 || check_maybe_up (flag_errno_math
)
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
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 + inline_edge_summary (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 (!gimple_has_body_p (callee
->decl
))
564 e
->inline_failed
= CIF_BODY_NOT_AVAILABLE
;
567 /* In early inliner some of callees may not be in SSA form yet
568 (i.e. the callgraph is cyclic and we did not process
569 the callee by early inliner, yet). We don't have CIF code for this
570 case; later we will re-do the decision in the real inliner. */
571 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e
->caller
->decl
))
572 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee
->decl
)))
575 fprintf (dump_file
, " edge not inlinable: not in SSA form\n");
578 if (!can_inline_edge_p (e
, true, false, true))
584 /* Return number of calls in N. Ignore cheap builtins. */
587 num_calls (struct cgraph_node
*n
)
589 struct cgraph_edge
*e
;
592 for (e
= n
->callees
; e
; e
= e
->next_callee
)
593 if (!is_inexpensive_builtin (e
->callee
->decl
))
599 /* Return true if we are interested in inlining small function. */
602 want_early_inline_function_p (struct cgraph_edge
*e
)
604 bool want_inline
= true;
605 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
607 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
609 /* For AutoFDO, we need to make sure that before profile summary, all
610 hot paths' IR look exactly the same as profiled binary. As a result,
611 in einliner, we will disregard size limit and inline those callsites
613 * inlined in the profiled binary, and
614 * the cloned callee has enough samples to be considered "hot". */
615 else if (flag_auto_profile
&& afdo_callsite_hot_enough_for_early_inline (e
))
617 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
618 && !opt_for_fn (e
->caller
->decl
, flag_inline_small_functions
))
620 e
->inline_failed
= CIF_FUNCTION_NOT_INLINE_CANDIDATE
;
621 report_inline_failed_reason (e
);
626 int growth
= estimate_edge_growth (e
);
631 else if (!e
->maybe_hot_p ()
635 fprintf (dump_file
, " will not early inline: %s/%i->%s/%i, "
636 "call is cold and code would grow by %i\n",
637 xstrdup_for_dump (e
->caller
->name ()),
639 xstrdup_for_dump (callee
->name ()), callee
->order
,
643 else if (growth
> 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\n",
648 xstrdup_for_dump (e
->caller
->name ()),
650 xstrdup_for_dump (callee
->name ()), callee
->order
,
654 else if ((n
= num_calls (callee
)) != 0
655 && growth
* (n
+ 1) > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS
))
658 fprintf (dump_file
, " will not early inline: %s/%i->%s/%i, "
659 "growth %i exceeds --param early-inlining-insns "
660 "divided by number of calls\n",
661 xstrdup_for_dump (e
->caller
->name ()),
663 xstrdup_for_dump (callee
->name ()), callee
->order
,
671 /* Compute time of the edge->caller + edge->callee execution when inlining
675 compute_uninlined_call_time (struct inline_summary
*callee_info
,
676 struct cgraph_edge
*edge
)
678 sreal uninlined_call_time
= (sreal
)callee_info
->time
;
679 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
680 ? edge
->caller
->global
.inlined_to
683 if (edge
->count
&& caller
->count
)
684 uninlined_call_time
*= (sreal
)edge
->count
/ caller
->count
;
686 uninlined_call_time
*= cgraph_freq_base_rec
* edge
->frequency
;
688 uninlined_call_time
= uninlined_call_time
>> 11;
690 int caller_time
= inline_summaries
->get (caller
)->time
;
691 return uninlined_call_time
+ caller_time
;
694 /* Same as compute_uinlined_call_time but compute time when inlining
698 compute_inlined_call_time (struct cgraph_edge
*edge
,
701 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
702 ? edge
->caller
->global
.inlined_to
704 int caller_time
= inline_summaries
->get (caller
)->time
;
705 sreal time
= edge_time
;
707 if (edge
->count
&& caller
->count
)
708 time
*= (sreal
)edge
->count
/ caller
->count
;
710 time
*= cgraph_freq_base_rec
* edge
->frequency
;
714 /* This calculation should match one in ipa-inline-analysis.
715 FIXME: Once ipa-inline-analysis is converted to sreal this can be
717 time
-= (sreal
) ((gcov_type
) edge
->frequency
718 * inline_edge_summary (edge
)->call_stmt_time
719 * (INLINE_TIME_SCALE
/ CGRAPH_FREQ_BASE
)) / INLINE_TIME_SCALE
;
722 time
= ((sreal
) 1) >> 8;
723 gcc_checking_assert (time
>= 0);
727 /* Return true if the speedup for inlining E is bigger than
728 PARAM_MAX_INLINE_MIN_SPEEDUP. */
731 big_speedup_p (struct cgraph_edge
*e
)
733 sreal time
= compute_uninlined_call_time (inline_summaries
->get (e
->callee
),
735 sreal inlined_time
= compute_inlined_call_time (e
, estimate_edge_time (e
));
737 if (time
- inlined_time
738 > (sreal
) time
* PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP
)
744 /* Return true if we are interested in inlining small function.
745 When REPORT is true, report reason to dump file. */
748 want_inline_small_function_p (struct cgraph_edge
*e
, bool report
)
750 bool want_inline
= true;
751 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
753 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
755 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
756 && !opt_for_fn (e
->caller
->decl
, flag_inline_small_functions
))
758 e
->inline_failed
= CIF_FUNCTION_NOT_INLINE_CANDIDATE
;
761 /* Do fast and conservative check if the function can be good
762 inline candidate. At the moment we allow inline hints to
763 promote non-inline functions to inline and we increase
764 MAX_INLINE_INSNS_SINGLE 16-fold for inline functions. */
765 else if ((!DECL_DECLARED_INLINE_P (callee
->decl
)
766 && (!e
->count
|| !e
->maybe_hot_p ()))
767 && inline_summaries
->get (callee
)->min_size
768 - inline_edge_summary (e
)->call_stmt_size
769 > MAX (MAX_INLINE_INSNS_SINGLE
, MAX_INLINE_INSNS_AUTO
))
771 e
->inline_failed
= CIF_MAX_INLINE_INSNS_AUTO_LIMIT
;
774 else if ((DECL_DECLARED_INLINE_P (callee
->decl
) || e
->count
)
775 && inline_summaries
->get (callee
)->min_size
776 - inline_edge_summary (e
)->call_stmt_size
777 > 16 * MAX_INLINE_INSNS_SINGLE
)
779 e
->inline_failed
= (DECL_DECLARED_INLINE_P (callee
->decl
)
780 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
781 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT
);
786 int growth
= estimate_edge_growth (e
);
787 inline_hints hints
= estimate_edge_hints (e
);
788 bool big_speedup
= big_speedup_p (e
);
792 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when
793 hints suggests that inlining given function is very profitable. */
794 else if (DECL_DECLARED_INLINE_P (callee
->decl
)
795 && growth
>= MAX_INLINE_INSNS_SINGLE
797 && !(hints
& (INLINE_HINT_indirect_call
798 | INLINE_HINT_known_hot
799 | INLINE_HINT_loop_iterations
800 | INLINE_HINT_array_index
801 | INLINE_HINT_loop_stride
)))
802 || growth
>= MAX_INLINE_INSNS_SINGLE
* 16))
804 e
->inline_failed
= CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
;
807 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
808 && !opt_for_fn (e
->caller
->decl
, flag_inline_functions
))
810 /* growth_likely_positive is expensive, always test it last. */
811 if (growth
>= MAX_INLINE_INSNS_SINGLE
812 || growth_likely_positive (callee
, growth
))
814 e
->inline_failed
= CIF_NOT_DECLARED_INLINED
;
818 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline
819 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that
820 inlining given function is very profitable. */
821 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
823 && !(hints
& INLINE_HINT_known_hot
)
824 && growth
>= ((hints
& (INLINE_HINT_indirect_call
825 | INLINE_HINT_loop_iterations
826 | INLINE_HINT_array_index
827 | INLINE_HINT_loop_stride
))
828 ? MAX (MAX_INLINE_INSNS_AUTO
,
829 MAX_INLINE_INSNS_SINGLE
)
830 : MAX_INLINE_INSNS_AUTO
))
832 /* growth_likely_positive is expensive, always test it last. */
833 if (growth
>= MAX_INLINE_INSNS_SINGLE
834 || growth_likely_positive (callee
, growth
))
836 e
->inline_failed
= CIF_MAX_INLINE_INSNS_AUTO_LIMIT
;
840 /* If call is cold, do not inline when function body would grow. */
841 else if (!e
->maybe_hot_p ()
842 && (growth
>= MAX_INLINE_INSNS_SINGLE
843 || growth_likely_positive (callee
, growth
)))
845 e
->inline_failed
= CIF_UNLIKELY_CALL
;
849 if (!want_inline
&& report
)
850 report_inline_failed_reason (e
);
854 /* EDGE is self recursive edge.
855 We hand two cases - when function A is inlining into itself
856 or when function A is being inlined into another inliner copy of function
859 In first case OUTER_NODE points to the toplevel copy of A, while
860 in the second case OUTER_NODE points to the outermost copy of A in B.
862 In both cases we want to be extra selective since
863 inlining the call will just introduce new recursive calls to appear. */
866 want_inline_self_recursive_call_p (struct cgraph_edge
*edge
,
867 struct cgraph_node
*outer_node
,
871 char const *reason
= NULL
;
872 bool want_inline
= true;
873 int caller_freq
= CGRAPH_FREQ_BASE
;
874 int max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO
);
876 if (DECL_DECLARED_INLINE_P (edge
->caller
->decl
))
877 max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH
);
879 if (!edge
->maybe_hot_p ())
881 reason
= "recursive call is cold";
884 else if (max_count
&& !outer_node
->count
)
886 reason
= "not executed in profile";
889 else if (depth
> max_depth
)
891 reason
= "--param max-inline-recursive-depth exceeded.";
895 if (outer_node
->global
.inlined_to
)
896 caller_freq
= outer_node
->callers
->frequency
;
900 reason
= "function is inlined and unlikely";
906 /* Inlining of self recursive function into copy of itself within other function
907 is transformation similar to loop peeling.
909 Peeling is profitable if we can inline enough copies to make probability
910 of actual call to the self recursive function very small. Be sure that
911 the probability of recursion is small.
913 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
914 This way the expected number of recision is at most max_depth. */
917 int max_prob
= CGRAPH_FREQ_BASE
- ((CGRAPH_FREQ_BASE
+ max_depth
- 1)
920 for (i
= 1; i
< depth
; i
++)
921 max_prob
= max_prob
* max_prob
/ CGRAPH_FREQ_BASE
;
923 && (edge
->count
* CGRAPH_FREQ_BASE
/ outer_node
->count
926 reason
= "profile of recursive call is too large";
930 && (edge
->frequency
* CGRAPH_FREQ_BASE
/ caller_freq
933 reason
= "frequency of recursive call is too large";
937 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if recursion
938 depth is large. We reduce function call overhead and increase chances that
939 things fit in hardware return predictor.
941 Recursive inlining might however increase cost of stack frame setup
942 actually slowing down functions whose recursion tree is wide rather than
945 Deciding reliably on when to do recursive inlining without profile feedback
946 is tricky. For now we disable recursive inlining when probability of self
949 Recursive inlining of self recursive call within loop also results in large loop
950 depths that generally optimize badly. We may want to throttle down inlining
951 in those cases. In particular this seems to happen in one of libstdc++ rb tree
956 && (edge
->count
* 100 / outer_node
->count
957 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY
)))
959 reason
= "profile of recursive call is too small";
963 && (edge
->frequency
* 100 / caller_freq
964 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY
)))
966 reason
= "frequency of recursive call is too small";
970 if (!want_inline
&& dump_file
)
971 fprintf (dump_file
, " not inlining recursively: %s\n", reason
);
975 /* Return true when NODE has uninlinable caller;
976 set HAS_HOT_CALL if it has hot call.
977 Worker for cgraph_for_node_and_aliases. */
980 check_callers (struct cgraph_node
*node
, void *has_hot_call
)
982 struct cgraph_edge
*e
;
983 for (e
= node
->callers
; e
; e
= e
->next_caller
)
985 if (!opt_for_fn (e
->caller
->decl
, flag_inline_functions_called_once
))
987 if (!can_inline_edge_p (e
, true))
989 if (e
->recursive_p ())
991 if (!(*(bool *)has_hot_call
) && e
->maybe_hot_p ())
992 *(bool *)has_hot_call
= true;
997 /* If NODE has a caller, return true. */
1000 has_caller_p (struct cgraph_node
*node
, void *data ATTRIBUTE_UNUSED
)
1007 /* Decide if inlining NODE would reduce unit size by eliminating
1008 the offline copy of function.
1009 When COLD is true the cold calls are considered, too. */
1012 want_inline_function_to_all_callers_p (struct cgraph_node
*node
, bool cold
)
1014 bool has_hot_call
= false;
1016 /* Aliases gets inlined along with the function they alias. */
1019 /* Already inlined? */
1020 if (node
->global
.inlined_to
)
1022 /* Does it have callers? */
1023 if (!node
->call_for_symbol_and_aliases (has_caller_p
, NULL
, true))
1025 /* Inlining into all callers would increase size? */
1026 if (estimate_growth (node
) > 0)
1028 /* All inlines must be possible. */
1029 if (node
->call_for_symbol_and_aliases (check_callers
, &has_hot_call
,
1032 if (!cold
&& !has_hot_call
)
1037 /* A cost model driving the inlining heuristics in a way so the edges with
1038 smallest badness are inlined first. After each inlining is performed
1039 the costs of all caller edges of nodes affected are recomputed so the
1040 metrics may accurately depend on values such as number of inlinable callers
1041 of the function or function body size. */
1044 edge_badness (struct cgraph_edge
*edge
, bool dump
)
1047 int growth
, edge_time
;
1048 struct cgraph_node
*callee
= edge
->callee
->ultimate_alias_target ();
1049 struct inline_summary
*callee_info
= inline_summaries
->get (callee
);
1051 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
1052 ? edge
->caller
->global
.inlined_to
1055 growth
= estimate_edge_growth (edge
);
1056 edge_time
= estimate_edge_time (edge
);
1057 hints
= estimate_edge_hints (edge
);
1058 gcc_checking_assert (edge_time
>= 0);
1059 gcc_checking_assert (edge_time
<= callee_info
->time
);
1060 gcc_checking_assert (growth
<= callee_info
->size
);
1064 fprintf (dump_file
, " Badness calculation for %s/%i -> %s/%i\n",
1065 xstrdup_for_dump (edge
->caller
->name ()),
1066 edge
->caller
->order
,
1067 xstrdup_for_dump (callee
->name ()),
1068 edge
->callee
->order
);
1069 fprintf (dump_file
, " size growth %i, time %i ",
1072 dump_inline_hints (dump_file
, hints
);
1073 if (big_speedup_p (edge
))
1074 fprintf (dump_file
, " big_speedup");
1075 fprintf (dump_file
, "\n");
1078 /* Always prefer inlining saving code size. */
1081 badness
= (sreal
) (-SREAL_MIN_SIG
+ growth
) << (SREAL_MAX_EXP
/ 256);
1083 fprintf (dump_file
, " %f: Growth %d <= 0\n", badness
.to_double (),
1086 /* Inlining into EXTERNAL functions is not going to change anything unless
1087 they are themselves inlined. */
1088 else if (DECL_EXTERNAL (caller
->decl
))
1091 fprintf (dump_file
, " max: function is external\n");
1092 return sreal::max ();
1094 /* When profile is available. Compute badness as:
1096 time_saved * caller_count
1097 goodness = -------------------------------------------------
1098 growth_of_caller * overall_growth * combined_size
1100 badness = - goodness
1102 Again use negative value to make calls with profile appear hotter
1105 else if (opt_for_fn (caller
->decl
, flag_guess_branch_prob
) || caller
->count
)
1107 sreal numerator
, denominator
;
1110 numerator
= (compute_uninlined_call_time (callee_info
, edge
)
1111 - compute_inlined_call_time (edge
, edge_time
));
1113 numerator
= ((sreal
) 1 >> 8);
1115 numerator
*= caller
->count
;
1116 else if (opt_for_fn (caller
->decl
, flag_branch_probabilities
))
1117 numerator
= numerator
>> 11;
1118 denominator
= growth
;
1120 overall_growth
= callee_info
->growth
;
1122 /* Look for inliner wrappers of the form:
1128 noninline_callee ();
1130 Withhout panilizing this case, we usually inline noninline_callee
1131 into the inline_caller because overall_growth is small preventing
1132 further inlining of inline_caller.
1134 Penalize only callgraph edges to functions with small overall
1137 if (growth
> overall_growth
1138 /* ... and having only one caller which is not inlined ... */
1139 && callee_info
->single_caller
1140 && !edge
->caller
->global
.inlined_to
1141 /* ... and edges executed only conditionally ... */
1142 && edge
->frequency
< CGRAPH_FREQ_BASE
1143 /* ... consider case where callee is not inline but caller is ... */
1144 && ((!DECL_DECLARED_INLINE_P (edge
->callee
->decl
)
1145 && DECL_DECLARED_INLINE_P (caller
->decl
))
1146 /* ... or when early optimizers decided to split and edge
1147 frequency still indicates splitting is a win ... */
1148 || (callee
->split_part
&& !caller
->split_part
1152 (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY
) / 100
1153 /* ... and do not overwrite user specified hints. */
1154 && (!DECL_DECLARED_INLINE_P (edge
->callee
->decl
)
1155 || DECL_DECLARED_INLINE_P (caller
->decl
)))))
1157 struct inline_summary
*caller_info
= inline_summaries
->get (caller
);
1158 int caller_growth
= caller_info
->growth
;
1160 /* Only apply the penalty when caller looks like inline candidate,
1161 and it is not called once and. */
1162 if (!caller_info
->single_caller
&& overall_growth
< caller_growth
1163 && caller_info
->inlinable
1164 && caller_info
->size
1165 < (DECL_DECLARED_INLINE_P (caller
->decl
)
1166 ? MAX_INLINE_INSNS_SINGLE
: MAX_INLINE_INSNS_AUTO
))
1170 " Wrapper penalty. Increasing growth %i to %i\n",
1171 overall_growth
, caller_growth
);
1172 overall_growth
= caller_growth
;
1175 if (overall_growth
> 0)
1177 /* Strongly preffer functions with few callers that can be inlined
1178 fully. The square root here leads to smaller binaries at average.
1179 Watch however for extreme cases and return to linear function
1180 when growth is large. */
1181 if (overall_growth
< 256)
1182 overall_growth
*= overall_growth
;
1184 overall_growth
+= 256 * 256 - 256;
1185 denominator
*= overall_growth
;
1187 denominator
*= inline_summaries
->get (caller
)->self_size
+ growth
;
1189 badness
= - numerator
/ denominator
;
1194 " %f: guessed profile. frequency %f, count %" PRId64
1195 " caller count %" PRId64
1196 " time w/o inlining %f, time w inlining %f"
1197 " overall growth %i (current) %i (original)"
1198 " %i (compensated)\n",
1199 badness
.to_double (),
1200 (double)edge
->frequency
/ CGRAPH_FREQ_BASE
,
1201 edge
->count
, caller
->count
,
1202 compute_uninlined_call_time (callee_info
, edge
).to_double (),
1203 compute_inlined_call_time (edge
, edge_time
).to_double (),
1204 estimate_growth (callee
),
1205 callee_info
->growth
, overall_growth
);
1208 /* When function local profile is not available or it does not give
1209 useful information (ie frequency is zero), base the cost on
1210 loop nest and overall size growth, so we optimize for overall number
1211 of functions fully inlined in program. */
1214 int nest
= MIN (inline_edge_summary (edge
)->loop_depth
, 8);
1217 /* Decrease badness if call is nested. */
1219 badness
= badness
>> nest
;
1221 badness
= badness
<< nest
;
1223 fprintf (dump_file
, " %f: no profile. nest %i\n",
1224 badness
.to_double (), nest
);
1226 gcc_checking_assert (badness
!= 0);
1228 if (edge
->recursive_p ())
1229 badness
= badness
.shift (badness
> 0 ? 4 : -4);
1230 if ((hints
& (INLINE_HINT_indirect_call
1231 | INLINE_HINT_loop_iterations
1232 | INLINE_HINT_array_index
1233 | INLINE_HINT_loop_stride
))
1234 || callee_info
->growth
<= 0)
1235 badness
= badness
.shift (badness
> 0 ? -2 : 2);
1236 if (hints
& (INLINE_HINT_same_scc
))
1237 badness
= badness
.shift (badness
> 0 ? 3 : -3);
1238 else if (hints
& (INLINE_HINT_in_scc
))
1239 badness
= badness
.shift (badness
> 0 ? 2 : -2);
1240 else if (hints
& (INLINE_HINT_cross_module
))
1241 badness
= badness
.shift (badness
> 0 ? 1 : -1);
1242 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
1243 badness
= badness
.shift (badness
> 0 ? -4 : 4);
1244 else if ((hints
& INLINE_HINT_declared_inline
))
1245 badness
= badness
.shift (badness
> 0 ? -3 : 3);
1247 fprintf (dump_file
, " Adjusted by hints %f\n", badness
.to_double ());
1251 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1253 update_edge_key (edge_heap_t
*heap
, struct cgraph_edge
*edge
)
1255 sreal badness
= edge_badness (edge
, false);
1258 edge_heap_node_t
*n
= (edge_heap_node_t
*) edge
->aux
;
1259 gcc_checking_assert (n
->get_data () == edge
);
1261 /* fibonacci_heap::replace_key does busy updating of the
1262 heap that is unnecesarily expensive.
1263 We do lazy increases: after extracting minimum if the key
1264 turns out to be out of date, it is re-inserted into heap
1265 with correct value. */
1266 if (badness
< n
->get_key ())
1268 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1271 " decreasing badness %s/%i -> %s/%i, %f"
1273 xstrdup_for_dump (edge
->caller
->name ()),
1274 edge
->caller
->order
,
1275 xstrdup_for_dump (edge
->callee
->name ()),
1276 edge
->callee
->order
,
1277 n
->get_key ().to_double (),
1278 badness
.to_double ());
1280 heap
->decrease_key (n
, badness
);
1285 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1288 " enqueuing call %s/%i -> %s/%i, badness %f\n",
1289 xstrdup_for_dump (edge
->caller
->name ()),
1290 edge
->caller
->order
,
1291 xstrdup_for_dump (edge
->callee
->name ()),
1292 edge
->callee
->order
,
1293 badness
.to_double ());
1295 edge
->aux
= heap
->insert (badness
, edge
);
1300 /* NODE was inlined.
1301 All caller edges needs to be resetted because
1302 size estimates change. Similarly callees needs reset
1303 because better context may be known. */
1306 reset_edge_caches (struct cgraph_node
*node
)
1308 struct cgraph_edge
*edge
;
1309 struct cgraph_edge
*e
= node
->callees
;
1310 struct cgraph_node
*where
= node
;
1311 struct ipa_ref
*ref
;
1313 if (where
->global
.inlined_to
)
1314 where
= where
->global
.inlined_to
;
1316 for (edge
= where
->callers
; edge
; edge
= edge
->next_caller
)
1317 if (edge
->inline_failed
)
1318 reset_edge_growth_cache (edge
);
1320 FOR_EACH_ALIAS (where
, ref
)
1321 reset_edge_caches (dyn_cast
<cgraph_node
*> (ref
->referring
));
1327 if (!e
->inline_failed
&& e
->callee
->callees
)
1328 e
= e
->callee
->callees
;
1331 if (e
->inline_failed
)
1332 reset_edge_growth_cache (e
);
1339 if (e
->caller
== node
)
1341 e
= e
->caller
->callers
;
1343 while (!e
->next_callee
);
1349 /* Recompute HEAP nodes for each of caller of NODE.
1350 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1351 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1352 it is inlinable. Otherwise check all edges. */
1355 update_caller_keys (edge_heap_t
*heap
, struct cgraph_node
*node
,
1356 bitmap updated_nodes
,
1357 struct cgraph_edge
*check_inlinablity_for
)
1359 struct cgraph_edge
*edge
;
1360 struct ipa_ref
*ref
;
1362 if ((!node
->alias
&& !inline_summaries
->get (node
)->inlinable
)
1363 || node
->global
.inlined_to
)
1365 if (!bitmap_set_bit (updated_nodes
, node
->uid
))
1368 FOR_EACH_ALIAS (node
, ref
)
1370 struct cgraph_node
*alias
= dyn_cast
<cgraph_node
*> (ref
->referring
);
1371 update_caller_keys (heap
, alias
, updated_nodes
, check_inlinablity_for
);
1374 for (edge
= node
->callers
; edge
; edge
= edge
->next_caller
)
1375 if (edge
->inline_failed
)
1377 if (!check_inlinablity_for
1378 || check_inlinablity_for
== edge
)
1380 if (can_inline_edge_p (edge
, false)
1381 && want_inline_small_function_p (edge
, false))
1382 update_edge_key (heap
, edge
);
1385 report_inline_failed_reason (edge
);
1386 heap
->delete_node ((edge_heap_node_t
*) edge
->aux
);
1391 update_edge_key (heap
, edge
);
1395 /* Recompute HEAP nodes for each uninlined call in NODE.
1396 This is used when we know that edge badnesses are going only to increase
1397 (we introduced new call site) and thus all we need is to insert newly
1398 created edges into heap. */
1401 update_callee_keys (edge_heap_t
*heap
, struct cgraph_node
*node
,
1402 bitmap updated_nodes
)
1404 struct cgraph_edge
*e
= node
->callees
;
1409 if (!e
->inline_failed
&& e
->callee
->callees
)
1410 e
= e
->callee
->callees
;
1413 enum availability avail
;
1414 struct cgraph_node
*callee
;
1415 /* We do not reset callee growth cache here. Since we added a new call,
1416 growth chould have just increased and consequentely badness metric
1417 don't need updating. */
1418 if (e
->inline_failed
1419 && (callee
= e
->callee
->ultimate_alias_target (&avail
))
1420 && inline_summaries
->get (callee
)->inlinable
1421 && avail
>= AVAIL_AVAILABLE
1422 && !bitmap_bit_p (updated_nodes
, callee
->uid
))
1424 if (can_inline_edge_p (e
, false)
1425 && want_inline_small_function_p (e
, false))
1426 update_edge_key (heap
, e
);
1429 report_inline_failed_reason (e
);
1430 heap
->delete_node ((edge_heap_node_t
*) e
->aux
);
1440 if (e
->caller
== node
)
1442 e
= e
->caller
->callers
;
1444 while (!e
->next_callee
);
1450 /* Enqueue all recursive calls from NODE into priority queue depending on
1451 how likely we want to recursively inline the call. */
1454 lookup_recursive_calls (struct cgraph_node
*node
, struct cgraph_node
*where
,
1457 struct cgraph_edge
*e
;
1458 enum availability avail
;
1460 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1461 if (e
->callee
== node
1462 || (e
->callee
->ultimate_alias_target (&avail
) == node
1463 && avail
> AVAIL_INTERPOSABLE
))
1465 /* When profile feedback is available, prioritize by expected number
1467 heap
->insert (!max_count
? -e
->frequency
1468 : -(e
->count
/ ((max_count
+ (1<<24) - 1) / (1<<24))),
1471 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1472 if (!e
->inline_failed
)
1473 lookup_recursive_calls (node
, e
->callee
, heap
);
1476 /* Decide on recursive inlining: in the case function has recursive calls,
1477 inline until body size reaches given argument. If any new indirect edges
1478 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1482 recursive_inlining (struct cgraph_edge
*edge
,
1483 vec
<cgraph_edge
*> *new_edges
)
1485 int limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO
);
1486 edge_heap_t
heap (sreal::min ());
1487 struct cgraph_node
*node
;
1488 struct cgraph_edge
*e
;
1489 struct cgraph_node
*master_clone
= NULL
, *next
;
1493 node
= edge
->caller
;
1494 if (node
->global
.inlined_to
)
1495 node
= node
->global
.inlined_to
;
1497 if (DECL_DECLARED_INLINE_P (node
->decl
))
1498 limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE
);
1500 /* Make sure that function is small enough to be considered for inlining. */
1501 if (estimate_size_after_inlining (node
, edge
) >= limit
)
1503 lookup_recursive_calls (node
, node
, &heap
);
1509 " Performing recursive inlining on %s\n",
1512 /* Do the inlining and update list of recursive call during process. */
1513 while (!heap
.empty ())
1515 struct cgraph_edge
*curr
= heap
.extract_min ();
1516 struct cgraph_node
*cnode
, *dest
= curr
->callee
;
1518 if (!can_inline_edge_p (curr
, true))
1521 /* MASTER_CLONE is produced in the case we already started modified
1522 the function. Be sure to redirect edge to the original body before
1523 estimating growths otherwise we will be seeing growths after inlining
1524 the already modified body. */
1527 curr
->redirect_callee (master_clone
);
1528 reset_edge_growth_cache (curr
);
1531 if (estimate_size_after_inlining (node
, curr
) > limit
)
1533 curr
->redirect_callee (dest
);
1534 reset_edge_growth_cache (curr
);
1539 for (cnode
= curr
->caller
;
1540 cnode
->global
.inlined_to
; cnode
= cnode
->callers
->caller
)
1542 == curr
->callee
->ultimate_alias_target ()->decl
)
1545 if (!want_inline_self_recursive_call_p (curr
, node
, false, depth
))
1547 curr
->redirect_callee (dest
);
1548 reset_edge_growth_cache (curr
);
1555 " Inlining call of depth %i", depth
);
1558 fprintf (dump_file
, " called approx. %.2f times per call",
1559 (double)curr
->count
/ node
->count
);
1561 fprintf (dump_file
, "\n");
1565 /* We need original clone to copy around. */
1566 master_clone
= node
->create_clone (node
->decl
, node
->count
,
1567 CGRAPH_FREQ_BASE
, false, vNULL
,
1569 for (e
= master_clone
->callees
; e
; e
= e
->next_callee
)
1570 if (!e
->inline_failed
)
1571 clone_inlined_nodes (e
, true, false, NULL
, CGRAPH_FREQ_BASE
);
1572 curr
->redirect_callee (master_clone
);
1573 reset_edge_growth_cache (curr
);
1576 inline_call (curr
, false, new_edges
, &overall_size
, true);
1577 lookup_recursive_calls (node
, curr
->callee
, &heap
);
1581 if (!heap
.empty () && dump_file
)
1582 fprintf (dump_file
, " Recursive inlining growth limit met.\n");
1589 "\n Inlined %i times, "
1590 "body grown from size %i to %i, time %i to %i\n", n
,
1591 inline_summaries
->get (master_clone
)->size
, inline_summaries
->get (node
)->size
,
1592 inline_summaries
->get (master_clone
)->time
, inline_summaries
->get (node
)->time
);
1594 /* Remove master clone we used for inlining. We rely that clones inlined
1595 into master clone gets queued just before master clone so we don't
1597 for (node
= symtab
->first_function (); node
!= master_clone
;
1600 next
= symtab
->next_function (node
);
1601 if (node
->global
.inlined_to
== master_clone
)
1604 master_clone
->remove ();
1609 /* Given whole compilation unit estimate of INSNS, compute how large we can
1610 allow the unit to grow. */
1613 compute_max_insns (int insns
)
1615 int max_insns
= insns
;
1616 if (max_insns
< PARAM_VALUE (PARAM_LARGE_UNIT_INSNS
))
1617 max_insns
= PARAM_VALUE (PARAM_LARGE_UNIT_INSNS
);
1619 return ((int64_t) max_insns
1620 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH
)) / 100);
1624 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1627 add_new_edges_to_heap (edge_heap_t
*heap
, vec
<cgraph_edge
*> new_edges
)
1629 while (new_edges
.length () > 0)
1631 struct cgraph_edge
*edge
= new_edges
.pop ();
1633 gcc_assert (!edge
->aux
);
1634 if (edge
->inline_failed
1635 && can_inline_edge_p (edge
, true)
1636 && want_inline_small_function_p (edge
, true))
1637 edge
->aux
= heap
->insert (edge_badness (edge
, false), edge
);
1641 /* Remove EDGE from the fibheap. */
1644 heap_edge_removal_hook (struct cgraph_edge
*e
, void *data
)
1648 ((edge_heap_t
*)data
)->delete_node ((edge_heap_node_t
*)e
->aux
);
1653 /* Return true if speculation of edge E seems useful.
1654 If ANTICIPATE_INLINING is true, be conservative and hope that E
1658 speculation_useful_p (struct cgraph_edge
*e
, bool anticipate_inlining
)
1660 enum availability avail
;
1661 struct cgraph_node
*target
= e
->callee
->ultimate_alias_target (&avail
);
1662 struct cgraph_edge
*direct
, *indirect
;
1663 struct ipa_ref
*ref
;
1665 gcc_assert (e
->speculative
&& !e
->indirect_unknown_callee
);
1667 if (!e
->maybe_hot_p ())
1670 /* See if IP optimizations found something potentially useful about the
1671 function. For now we look only for CONST/PURE flags. Almost everything
1672 else we propagate is useless. */
1673 if (avail
>= AVAIL_AVAILABLE
)
1675 int ecf_flags
= flags_from_decl_or_type (target
->decl
);
1676 if (ecf_flags
& ECF_CONST
)
1678 e
->speculative_call_info (direct
, indirect
, ref
);
1679 if (!(indirect
->indirect_info
->ecf_flags
& ECF_CONST
))
1682 else if (ecf_flags
& ECF_PURE
)
1684 e
->speculative_call_info (direct
, indirect
, ref
);
1685 if (!(indirect
->indirect_info
->ecf_flags
& ECF_PURE
))
1689 /* If we did not managed to inline the function nor redirect
1690 to an ipa-cp clone (that are seen by having local flag set),
1691 it is probably pointless to inline it unless hardware is missing
1692 indirect call predictor. */
1693 if (!anticipate_inlining
&& e
->inline_failed
&& !target
->local
.local
)
1695 /* For overwritable targets there is not much to do. */
1696 if (e
->inline_failed
&& !can_inline_edge_p (e
, false, true))
1698 /* OK, speculation seems interesting. */
1702 /* We know that EDGE is not going to be inlined.
1703 See if we can remove speculation. */
1706 resolve_noninline_speculation (edge_heap_t
*edge_heap
, struct cgraph_edge
*edge
)
1708 if (edge
->speculative
&& !speculation_useful_p (edge
, false))
1710 struct cgraph_node
*node
= edge
->caller
;
1711 struct cgraph_node
*where
= node
->global
.inlined_to
1712 ? node
->global
.inlined_to
: node
;
1713 bitmap updated_nodes
= BITMAP_ALLOC (NULL
);
1715 spec_rem
+= edge
->count
;
1716 edge
->resolve_speculation ();
1717 reset_edge_caches (where
);
1718 inline_update_overall_summary (where
);
1719 update_caller_keys (edge_heap
, where
,
1720 updated_nodes
, NULL
);
1721 update_callee_keys (edge_heap
, where
,
1723 BITMAP_FREE (updated_nodes
);
1727 /* Return true if NODE should be accounted for overall size estimate.
1728 Skip all nodes optimized for size so we can measure the growth of hot
1729 part of program no matter of the padding. */
1732 inline_account_function_p (struct cgraph_node
*node
)
1734 return (!DECL_EXTERNAL (node
->decl
)
1735 && !opt_for_fn (node
->decl
, optimize_size
)
1736 && node
->frequency
!= NODE_FREQUENCY_UNLIKELY_EXECUTED
);
1739 /* Count number of callers of NODE and store it into DATA (that
1740 points to int. Worker for cgraph_for_node_and_aliases. */
1743 sum_callers (struct cgraph_node
*node
, void *data
)
1745 struct cgraph_edge
*e
;
1746 int *num_calls
= (int *)data
;
1748 for (e
= node
->callers
; e
; e
= e
->next_caller
)
1753 /* We use greedy algorithm for inlining of small functions:
1754 All inline candidates are put into prioritized heap ordered in
1757 The inlining of small functions is bounded by unit growth parameters. */
1760 inline_small_functions (void)
1762 struct cgraph_node
*node
;
1763 struct cgraph_edge
*edge
;
1764 edge_heap_t
edge_heap (sreal::min ());
1765 bitmap updated_nodes
= BITMAP_ALLOC (NULL
);
1766 int min_size
, max_size
;
1767 auto_vec
<cgraph_edge
*> new_indirect_edges
;
1768 int initial_size
= 0;
1769 struct cgraph_node
**order
= XCNEWVEC (cgraph_node
*, symtab
->cgraph_count
);
1770 struct cgraph_edge_hook_list
*edge_removal_hook_holder
;
1771 new_indirect_edges
.create (8);
1773 edge_removal_hook_holder
1774 = symtab
->add_edge_removal_hook (&heap_edge_removal_hook
, &edge_heap
);
1776 /* Compute overall unit size and other global parameters used by badness
1780 ipa_reduced_postorder (order
, true, true, NULL
);
1783 FOR_EACH_DEFINED_FUNCTION (node
)
1784 if (!node
->global
.inlined_to
)
1786 if (!node
->alias
&& node
->analyzed
1787 && (node
->has_gimple_body_p () || node
->thunk
.thunk_p
))
1789 struct inline_summary
*info
= inline_summaries
->get (node
);
1790 struct ipa_dfs_info
*dfs
= (struct ipa_dfs_info
*) node
->aux
;
1792 /* Do not account external functions, they will be optimized out
1793 if not inlined. Also only count the non-cold portion of program. */
1794 if (inline_account_function_p (node
))
1795 initial_size
+= info
->size
;
1796 info
->growth
= estimate_growth (node
);
1799 node
->call_for_symbol_and_aliases (sum_callers
, &num_calls
,
1802 info
->single_caller
= true;
1803 if (dfs
&& dfs
->next_cycle
)
1805 struct cgraph_node
*n2
;
1806 int id
= dfs
->scc_no
+ 1;
1808 n2
= ((struct ipa_dfs_info
*) node
->aux
)->next_cycle
)
1810 struct inline_summary
*info2
= inline_summaries
->get (n2
);
1818 for (edge
= node
->callers
; edge
; edge
= edge
->next_caller
)
1819 if (max_count
< edge
->count
)
1820 max_count
= edge
->count
;
1822 ipa_free_postorder_info ();
1823 initialize_growth_caches ();
1827 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1830 overall_size
= initial_size
;
1831 max_size
= compute_max_insns (overall_size
);
1832 min_size
= overall_size
;
1834 /* Populate the heap with all edges we might inline. */
1836 FOR_EACH_DEFINED_FUNCTION (node
)
1838 bool update
= false;
1839 struct cgraph_edge
*next
= NULL
;
1840 bool has_speculative
= false;
1843 fprintf (dump_file
, "Enqueueing calls in %s/%i.\n",
1844 node
->name (), node
->order
);
1846 for (edge
= node
->callees
; edge
; edge
= next
)
1848 next
= edge
->next_callee
;
1849 if (edge
->inline_failed
1851 && can_inline_edge_p (edge
, true)
1852 && want_inline_small_function_p (edge
, true)
1853 && edge
->inline_failed
)
1855 gcc_assert (!edge
->aux
);
1856 update_edge_key (&edge_heap
, edge
);
1858 if (edge
->speculative
)
1859 has_speculative
= true;
1861 if (has_speculative
)
1862 for (edge
= node
->callees
; edge
; edge
= next
)
1863 if (edge
->speculative
&& !speculation_useful_p (edge
,
1866 edge
->resolve_speculation ();
1871 struct cgraph_node
*where
= node
->global
.inlined_to
1872 ? node
->global
.inlined_to
: node
;
1873 inline_update_overall_summary (where
);
1874 reset_edge_caches (where
);
1875 update_caller_keys (&edge_heap
, where
,
1876 updated_nodes
, NULL
);
1877 update_callee_keys (&edge_heap
, where
,
1879 bitmap_clear (updated_nodes
);
1883 gcc_assert (in_lto_p
1885 || (profile_info
&& flag_branch_probabilities
));
1887 while (!edge_heap
.empty ())
1889 int old_size
= overall_size
;
1890 struct cgraph_node
*where
, *callee
;
1891 sreal badness
= edge_heap
.min_key ();
1892 sreal current_badness
;
1895 edge
= edge_heap
.extract_min ();
1896 gcc_assert (edge
->aux
);
1898 if (!edge
->inline_failed
|| !edge
->callee
->analyzed
)
1901 #ifdef ENABLE_CHECKING
1902 /* Be sure that caches are maintained consistent. */
1903 sreal cached_badness
= edge_badness (edge
, false);
1905 int old_size_est
= estimate_edge_size (edge
);
1906 int old_time_est
= estimate_edge_time (edge
);
1907 int old_hints_est
= estimate_edge_hints (edge
);
1909 reset_edge_growth_cache (edge
);
1910 gcc_assert (old_size_est
== estimate_edge_size (edge
));
1911 gcc_assert (old_time_est
== estimate_edge_time (edge
));
1914 gcc_assert (old_hints_est == estimate_edge_hints (edge));
1916 fails with profile feedback because some hints depends on
1917 maybe_hot_edge_p predicate and because callee gets inlined to other
1918 calls, the edge may become cold.
1919 This ought to be fixed by computing relative probabilities
1920 for given invocation but that will be better done once whole
1921 code is converted to sreals. Disable for now and revert to "wrong"
1922 value so enable/disable checking paths agree. */
1923 edge_growth_cache
[edge
->uid
].hints
= old_hints_est
+ 1;
1925 /* When updating the edge costs, we only decrease badness in the keys.
1926 Increases of badness are handled lazilly; when we see key with out
1927 of date value on it, we re-insert it now. */
1928 current_badness
= edge_badness (edge
, false);
1929 /* Disable checking for profile because roundoff errors may cause slight
1930 deviations in the order. */
1931 gcc_assert (max_count
|| cached_badness
== current_badness
);
1932 gcc_assert (current_badness
>= badness
);
1934 current_badness
= edge_badness (edge
, false);
1936 if (current_badness
!= badness
)
1938 if (edge_heap
.min () && current_badness
> edge_heap
.min_key ())
1940 edge
->aux
= edge_heap
.insert (current_badness
, edge
);
1944 badness
= current_badness
;
1947 if (!can_inline_edge_p (edge
, true))
1949 resolve_noninline_speculation (&edge_heap
, edge
);
1953 callee
= edge
->callee
->ultimate_alias_target ();
1954 growth
= estimate_edge_growth (edge
);
1958 "\nConsidering %s/%i with %i size\n",
1959 callee
->name (), callee
->order
,
1960 inline_summaries
->get (callee
)->size
);
1962 " to be inlined into %s/%i in %s:%i\n"
1963 " Estimated badness is %f, frequency %.2f.\n",
1964 edge
->caller
->name (), edge
->caller
->order
,
1966 && (LOCATION_LOCUS (gimple_location ((const_gimple
)
1968 > BUILTINS_LOCATION
)
1969 ? gimple_filename ((const_gimple
) edge
->call_stmt
)
1972 ? gimple_lineno ((const_gimple
) edge
->call_stmt
)
1974 badness
.to_double (),
1975 edge
->frequency
/ (double)CGRAPH_FREQ_BASE
);
1977 fprintf (dump_file
," Called %" PRId64
"x\n",
1979 if (dump_flags
& TDF_DETAILS
)
1980 edge_badness (edge
, true);
1983 if (overall_size
+ growth
> max_size
1984 && !DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
1986 edge
->inline_failed
= CIF_INLINE_UNIT_GROWTH_LIMIT
;
1987 report_inline_failed_reason (edge
);
1988 resolve_noninline_speculation (&edge_heap
, edge
);
1992 if (!want_inline_small_function_p (edge
, true))
1994 resolve_noninline_speculation (&edge_heap
, edge
);
1998 /* Heuristics for inlining small functions work poorly for
1999 recursive calls where we do effects similar to loop unrolling.
2000 When inlining such edge seems profitable, leave decision on
2001 specific inliner. */
2002 if (edge
->recursive_p ())
2004 where
= edge
->caller
;
2005 if (where
->global
.inlined_to
)
2006 where
= where
->global
.inlined_to
;
2007 if (!recursive_inlining (edge
,
2008 opt_for_fn (edge
->caller
->decl
,
2009 flag_indirect_inlining
)
2010 ? &new_indirect_edges
: NULL
))
2012 edge
->inline_failed
= CIF_RECURSIVE_INLINING
;
2013 resolve_noninline_speculation (&edge_heap
, edge
);
2016 reset_edge_caches (where
);
2017 /* Recursive inliner inlines all recursive calls of the function
2018 at once. Consequently we need to update all callee keys. */
2019 if (opt_for_fn (edge
->caller
->decl
, flag_indirect_inlining
))
2020 add_new_edges_to_heap (&edge_heap
, new_indirect_edges
);
2021 update_callee_keys (&edge_heap
, where
, updated_nodes
);
2022 bitmap_clear (updated_nodes
);
2026 struct cgraph_node
*outer_node
= NULL
;
2029 /* Consider the case where self recursive function A is inlined
2030 into B. This is desired optimization in some cases, since it
2031 leads to effect similar of loop peeling and we might completely
2032 optimize out the recursive call. However we must be extra
2035 where
= edge
->caller
;
2036 while (where
->global
.inlined_to
)
2038 if (where
->decl
== callee
->decl
)
2039 outer_node
= where
, depth
++;
2040 where
= where
->callers
->caller
;
2043 && !want_inline_self_recursive_call_p (edge
, outer_node
,
2047 = (DECL_DISREGARD_INLINE_LIMITS (edge
->callee
->decl
)
2048 ? CIF_RECURSIVE_INLINING
: CIF_UNSPECIFIED
);
2049 resolve_noninline_speculation (&edge_heap
, edge
);
2052 else if (depth
&& dump_file
)
2053 fprintf (dump_file
, " Peeling recursion with depth %i\n", depth
);
2055 gcc_checking_assert (!callee
->global
.inlined_to
);
2056 inline_call (edge
, true, &new_indirect_edges
, &overall_size
, true);
2057 add_new_edges_to_heap (&edge_heap
, new_indirect_edges
);
2059 reset_edge_caches (edge
->callee
->function_symbol ());
2061 update_callee_keys (&edge_heap
, where
, updated_nodes
);
2063 where
= edge
->caller
;
2064 if (where
->global
.inlined_to
)
2065 where
= where
->global
.inlined_to
;
2067 /* Our profitability metric can depend on local properties
2068 such as number of inlinable calls and size of the function body.
2069 After inlining these properties might change for the function we
2070 inlined into (since it's body size changed) and for the functions
2071 called by function we inlined (since number of it inlinable callers
2073 update_caller_keys (&edge_heap
, where
, updated_nodes
, NULL
);
2074 /* Offline copy count has possibly changed, recompute if profile is
2078 struct cgraph_node
*n
= cgraph_node::get (edge
->callee
->decl
);
2079 if (n
!= edge
->callee
&& n
->analyzed
)
2080 update_callee_keys (&edge_heap
, n
, updated_nodes
);
2082 bitmap_clear (updated_nodes
);
2087 " Inlined into %s which now has time %i and size %i,"
2088 "net change of %+i.\n",
2089 edge
->caller
->name (),
2090 inline_summaries
->get (edge
->caller
)->time
,
2091 inline_summaries
->get (edge
->caller
)->size
,
2092 overall_size
- old_size
);
2094 if (min_size
> overall_size
)
2096 min_size
= overall_size
;
2097 max_size
= compute_max_insns (min_size
);
2100 fprintf (dump_file
, "New minimal size reached: %i\n", min_size
);
2104 free_growth_caches ();
2107 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2108 initial_size
, overall_size
,
2109 initial_size
? overall_size
* 100 / (initial_size
) - 100: 0);
2110 BITMAP_FREE (updated_nodes
);
2111 symtab
->remove_edge_removal_hook (edge_removal_hook_holder
);
2114 /* Flatten NODE. Performed both during early inlining and
2115 at IPA inlining time. */
2118 flatten_function (struct cgraph_node
*node
, bool early
)
2120 struct cgraph_edge
*e
;
2122 /* We shouldn't be called recursively when we are being processed. */
2123 gcc_assert (node
->aux
== NULL
);
2125 node
->aux
= (void *) node
;
2127 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2129 struct cgraph_node
*orig_callee
;
2130 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2132 /* We've hit cycle? It is time to give up. */
2137 "Not inlining %s into %s to avoid cycle.\n",
2138 xstrdup_for_dump (callee
->name ()),
2139 xstrdup_for_dump (e
->caller
->name ()));
2140 e
->inline_failed
= CIF_RECURSIVE_INLINING
;
2144 /* When the edge is already inlined, we just need to recurse into
2145 it in order to fully flatten the leaves. */
2146 if (!e
->inline_failed
)
2148 flatten_function (callee
, early
);
2152 /* Flatten attribute needs to be processed during late inlining. For
2153 extra code quality we however do flattening during early optimization,
2156 ? !can_inline_edge_p (e
, true)
2157 : !can_early_inline_edge_p (e
))
2160 if (e
->recursive_p ())
2163 fprintf (dump_file
, "Not inlining: recursive call.\n");
2167 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node
->decl
))
2168 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee
->decl
)))
2171 fprintf (dump_file
, "Not inlining: SSA form does not match.\n");
2175 /* Inline the edge and flatten the inline clone. Avoid
2176 recursing through the original node if the node was cloned. */
2178 fprintf (dump_file
, " Inlining %s into %s.\n",
2179 xstrdup_for_dump (callee
->name ()),
2180 xstrdup_for_dump (e
->caller
->name ()));
2181 orig_callee
= callee
;
2182 inline_call (e
, true, NULL
, NULL
, false);
2183 if (e
->callee
!= orig_callee
)
2184 orig_callee
->aux
= (void *) node
;
2185 flatten_function (e
->callee
, early
);
2186 if (e
->callee
!= orig_callee
)
2187 orig_callee
->aux
= NULL
;
2191 if (!node
->global
.inlined_to
)
2192 inline_update_overall_summary (node
);
2195 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2196 DATA points to number of calls originally found so we avoid infinite
2200 inline_to_all_callers (struct cgraph_node
*node
, void *data
)
2202 int *num_calls
= (int *)data
;
2203 bool callee_removed
= false;
2205 while (node
->callers
&& !node
->global
.inlined_to
)
2207 struct cgraph_node
*caller
= node
->callers
->caller
;
2209 if (!can_inline_edge_p (node
->callers
, true)
2210 || node
->callers
->recursive_p ())
2213 fprintf (dump_file
, "Uninlinable call found; giving up.\n");
2221 "\nInlining %s size %i.\n",
2223 inline_summaries
->get (node
)->size
);
2225 " Called once from %s %i insns.\n",
2226 node
->callers
->caller
->name (),
2227 inline_summaries
->get (node
->callers
->caller
)->size
);
2230 inline_call (node
->callers
, true, NULL
, NULL
, true, &callee_removed
);
2233 " Inlined into %s which now has %i size\n",
2235 inline_summaries
->get (caller
)->size
);
2236 if (!(*num_calls
)--)
2239 fprintf (dump_file
, "New calls found; giving up.\n");
2240 return callee_removed
;
2248 /* Output overall time estimate. */
2250 dump_overall_stats (void)
2252 int64_t sum_weighted
= 0, sum
= 0;
2253 struct cgraph_node
*node
;
2255 FOR_EACH_DEFINED_FUNCTION (node
)
2256 if (!node
->global
.inlined_to
2259 int time
= inline_summaries
->get (node
)->time
;
2261 sum_weighted
+= time
* node
->count
;
2263 fprintf (dump_file
, "Overall time estimate: "
2264 "%" PRId64
" weighted by profile: "
2265 "%" PRId64
"\n", sum
, sum_weighted
);
2268 /* Output some useful stats about inlining. */
2271 dump_inline_stats (void)
2273 int64_t inlined_cnt
= 0, inlined_indir_cnt
= 0;
2274 int64_t inlined_virt_cnt
= 0, inlined_virt_indir_cnt
= 0;
2275 int64_t noninlined_cnt
= 0, noninlined_indir_cnt
= 0;
2276 int64_t noninlined_virt_cnt
= 0, noninlined_virt_indir_cnt
= 0;
2277 int64_t inlined_speculative
= 0, inlined_speculative_ply
= 0;
2278 int64_t indirect_poly_cnt
= 0, indirect_cnt
= 0;
2279 int64_t reason
[CIF_N_REASONS
][3];
2281 struct cgraph_node
*node
;
2283 memset (reason
, 0, sizeof (reason
));
2284 FOR_EACH_DEFINED_FUNCTION (node
)
2286 struct cgraph_edge
*e
;
2287 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2289 if (e
->inline_failed
)
2291 reason
[(int) e
->inline_failed
][0] += e
->count
;
2292 reason
[(int) e
->inline_failed
][1] += e
->frequency
;
2293 reason
[(int) e
->inline_failed
][2] ++;
2294 if (DECL_VIRTUAL_P (e
->callee
->decl
))
2296 if (e
->indirect_inlining_edge
)
2297 noninlined_virt_indir_cnt
+= e
->count
;
2299 noninlined_virt_cnt
+= e
->count
;
2303 if (e
->indirect_inlining_edge
)
2304 noninlined_indir_cnt
+= e
->count
;
2306 noninlined_cnt
+= e
->count
;
2313 if (DECL_VIRTUAL_P (e
->callee
->decl
))
2314 inlined_speculative_ply
+= e
->count
;
2316 inlined_speculative
+= e
->count
;
2318 else if (DECL_VIRTUAL_P (e
->callee
->decl
))
2320 if (e
->indirect_inlining_edge
)
2321 inlined_virt_indir_cnt
+= e
->count
;
2323 inlined_virt_cnt
+= e
->count
;
2327 if (e
->indirect_inlining_edge
)
2328 inlined_indir_cnt
+= e
->count
;
2330 inlined_cnt
+= e
->count
;
2334 for (e
= node
->indirect_calls
; e
; e
= e
->next_callee
)
2335 if (e
->indirect_info
->polymorphic
)
2336 indirect_poly_cnt
+= e
->count
;
2338 indirect_cnt
+= e
->count
;
2343 "Inlined %" PRId64
" + speculative "
2344 "%" PRId64
" + speculative polymorphic "
2345 "%" PRId64
" + previously indirect "
2346 "%" PRId64
" + virtual "
2347 "%" PRId64
" + virtual and previously indirect "
2348 "%" PRId64
"\n" "Not inlined "
2349 "%" PRId64
" + previously indirect "
2350 "%" PRId64
" + virtual "
2351 "%" PRId64
" + virtual and previously indirect "
2352 "%" PRId64
" + stil indirect "
2353 "%" PRId64
" + still indirect polymorphic "
2354 "%" PRId64
"\n", inlined_cnt
,
2355 inlined_speculative
, inlined_speculative_ply
,
2356 inlined_indir_cnt
, inlined_virt_cnt
, inlined_virt_indir_cnt
,
2357 noninlined_cnt
, noninlined_indir_cnt
, noninlined_virt_cnt
,
2358 noninlined_virt_indir_cnt
, indirect_cnt
, indirect_poly_cnt
);
2360 "Removed speculations %" PRId64
"\n",
2363 dump_overall_stats ();
2364 fprintf (dump_file
, "\nWhy inlining failed?\n");
2365 for (i
= 0; i
< CIF_N_REASONS
; i
++)
2367 fprintf (dump_file
, "%-50s: %8i calls, %8i freq, %" PRId64
" count\n",
2368 cgraph_inline_failed_string ((cgraph_inline_failed_t
) i
),
2369 (int) reason
[i
][2], (int) reason
[i
][1], reason
[i
][0]);
2372 /* Decide on the inlining. We do so in the topological order to avoid
2373 expenses on updating data structures. */
2378 struct cgraph_node
*node
;
2380 struct cgraph_node
**order
;
2383 bool remove_functions
= false;
2388 cgraph_freq_base_rec
= (sreal
) 1 / (sreal
) CGRAPH_FREQ_BASE
;
2389 percent_rec
= (sreal
) 1 / (sreal
) 100;
2391 order
= XCNEWVEC (struct cgraph_node
*, symtab
->cgraph_count
);
2393 if (in_lto_p
&& optimize
)
2394 ipa_update_after_lto_read ();
2397 dump_inline_summaries (dump_file
);
2399 nnodes
= ipa_reverse_postorder (order
);
2401 FOR_EACH_FUNCTION (node
)
2405 /* Recompute the default reasons for inlining because they may have
2406 changed during merging. */
2409 for (cgraph_edge
*e
= node
->callees
; e
; e
= e
->next_callee
)
2411 gcc_assert (e
->inline_failed
);
2412 initialize_inline_failed (e
);
2414 for (cgraph_edge
*e
= node
->indirect_calls
; e
; e
= e
->next_callee
)
2415 initialize_inline_failed (e
);
2420 fprintf (dump_file
, "\nFlattening functions:\n");
2422 /* In the first pass handle functions to be flattened. Do this with
2423 a priority so none of our later choices will make this impossible. */
2424 for (i
= nnodes
- 1; i
>= 0; i
--)
2428 /* Handle nodes to be flattened.
2429 Ideally when processing callees we stop inlining at the
2430 entry of cycles, possibly cloning that entry point and
2431 try to flatten itself turning it into a self-recursive
2433 if (lookup_attribute ("flatten",
2434 DECL_ATTRIBUTES (node
->decl
)) != NULL
)
2438 "Flattening %s\n", node
->name ());
2439 flatten_function (node
, false);
2443 dump_overall_stats ();
2445 inline_small_functions ();
2447 gcc_assert (symtab
->state
== IPA_SSA
);
2448 symtab
->state
= IPA_SSA_AFTER_INLINING
;
2449 /* Do first after-inlining removal. We want to remove all "stale" extern
2450 inline functions and virtual functions so we really know what is called
2452 symtab
->remove_unreachable_nodes (dump_file
);
2455 /* Inline functions with a property that after inlining into all callers the
2456 code size will shrink because the out-of-line copy is eliminated.
2457 We do this regardless on the callee size as long as function growth limits
2461 "\nDeciding on functions to be inlined into all callers and "
2462 "removing useless speculations:\n");
2464 /* Inlining one function called once has good chance of preventing
2465 inlining other function into the same callee. Ideally we should
2466 work in priority order, but probably inlining hot functions first
2467 is good cut without the extra pain of maintaining the queue.
2469 ??? this is not really fitting the bill perfectly: inlining function
2470 into callee often leads to better optimization of callee due to
2471 increased context for optimization.
2472 For example if main() function calls a function that outputs help
2473 and then function that does the main optmization, we should inline
2474 the second with priority even if both calls are cold by themselves.
2476 We probably want to implement new predicate replacing our use of
2477 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2479 for (cold
= 0; cold
<= 1; cold
++)
2481 FOR_EACH_DEFINED_FUNCTION (node
)
2483 struct cgraph_edge
*edge
, *next
;
2486 for (edge
= node
->callees
; edge
; edge
= next
)
2488 next
= edge
->next_callee
;
2489 if (edge
->speculative
&& !speculation_useful_p (edge
, false))
2491 edge
->resolve_speculation ();
2492 spec_rem
+= edge
->count
;
2494 remove_functions
= true;
2499 struct cgraph_node
*where
= node
->global
.inlined_to
2500 ? node
->global
.inlined_to
: node
;
2501 reset_edge_caches (where
);
2502 inline_update_overall_summary (where
);
2504 if (want_inline_function_to_all_callers_p (node
, cold
))
2507 node
->call_for_symbol_and_aliases (sum_callers
, &num_calls
,
2509 while (node
->call_for_symbol_and_aliases
2510 (inline_to_all_callers
, &num_calls
, true))
2512 remove_functions
= true;
2517 /* Free ipa-prop structures if they are no longer needed. */
2519 ipa_free_all_structures_after_iinln ();
2524 "\nInlined %i calls, eliminated %i functions\n\n",
2525 ncalls_inlined
, nfunctions_inlined
);
2526 dump_inline_stats ();
2530 dump_inline_summaries (dump_file
);
2531 /* In WPA we use inline summaries for partitioning process. */
2533 inline_free_summary ();
2534 return remove_functions
? TODO_remove_functions
: 0;
2537 /* Inline always-inline function calls in NODE. */
2540 inline_always_inline_functions (struct cgraph_node
*node
)
2542 struct cgraph_edge
*e
;
2543 bool inlined
= false;
2545 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2547 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2548 if (!DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
2551 if (e
->recursive_p ())
2554 fprintf (dump_file
, " Not inlining recursive call to %s.\n",
2555 e
->callee
->name ());
2556 e
->inline_failed
= CIF_RECURSIVE_INLINING
;
2560 if (!can_early_inline_edge_p (e
))
2562 /* Set inlined to true if the callee is marked "always_inline" but
2563 is not inlinable. This will allow flagging an error later in
2564 expand_call_inline in tree-inline.c. */
2565 if (lookup_attribute ("always_inline",
2566 DECL_ATTRIBUTES (callee
->decl
)) != NULL
)
2572 fprintf (dump_file
, " Inlining %s into %s (always_inline).\n",
2573 xstrdup_for_dump (e
->callee
->name ()),
2574 xstrdup_for_dump (e
->caller
->name ()));
2575 inline_call (e
, true, NULL
, NULL
, false);
2579 inline_update_overall_summary (node
);
2584 /* Decide on the inlining. We do so in the topological order to avoid
2585 expenses on updating data structures. */
2588 early_inline_small_functions (struct cgraph_node
*node
)
2590 struct cgraph_edge
*e
;
2591 bool inlined
= false;
2593 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2595 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2596 if (!inline_summaries
->get (callee
)->inlinable
2597 || !e
->inline_failed
)
2600 /* Do not consider functions not declared inline. */
2601 if (!DECL_DECLARED_INLINE_P (callee
->decl
)
2602 && !opt_for_fn (node
->decl
, flag_inline_small_functions
)
2603 && !opt_for_fn (node
->decl
, flag_inline_functions
))
2607 fprintf (dump_file
, "Considering inline candidate %s.\n",
2610 if (!can_early_inline_edge_p (e
))
2613 if (e
->recursive_p ())
2616 fprintf (dump_file
, " Not inlining: recursive call.\n");
2620 if (!want_early_inline_function_p (e
))
2624 fprintf (dump_file
, " Inlining %s into %s.\n",
2625 xstrdup_for_dump (callee
->name ()),
2626 xstrdup_for_dump (e
->caller
->name ()));
2627 inline_call (e
, true, NULL
, NULL
, true);
2635 early_inliner (function
*fun
)
2637 struct cgraph_node
*node
= cgraph_node::get (current_function_decl
);
2638 struct cgraph_edge
*edge
;
2639 unsigned int todo
= 0;
2641 bool inlined
= false;
2646 /* Do nothing if datastructures for ipa-inliner are already computed. This
2647 happens when some pass decides to construct new function and
2648 cgraph_add_new_function calls lowering passes and early optimization on
2649 it. This may confuse ourself when early inliner decide to inline call to
2650 function clone, because function clones don't have parameter list in
2651 ipa-prop matching their signature. */
2652 if (ipa_node_params_sum
)
2655 #ifdef ENABLE_CHECKING
2658 node
->remove_all_references ();
2660 /* Rebuild this reference because it dosn't depend on
2661 function's body and it's required to pass cgraph_node
2663 if (node
->instrumented_version
2664 && !node
->instrumentation_clone
)
2665 node
->create_reference (node
->instrumented_version
, IPA_REF_CHKP
, NULL
);
2667 /* Even when not optimizing or not inlining inline always-inline
2669 inlined
= inline_always_inline_functions (node
);
2673 || !flag_early_inlining
2674 /* Never inline regular functions into always-inline functions
2675 during incremental inlining. This sucks as functions calling
2676 always inline functions will get less optimized, but at the
2677 same time inlining of functions calling always inline
2678 function into an always inline function might introduce
2679 cycles of edges to be always inlined in the callgraph.
2681 We might want to be smarter and just avoid this type of inlining. */
2682 || (DECL_DISREGARD_INLINE_LIMITS (node
->decl
)
2683 && lookup_attribute ("always_inline",
2684 DECL_ATTRIBUTES (node
->decl
))))
2686 else if (lookup_attribute ("flatten",
2687 DECL_ATTRIBUTES (node
->decl
)) != NULL
)
2689 /* When the function is marked to be flattened, recursively inline
2693 "Flattening %s\n", node
->name ());
2694 flatten_function (node
, true);
2699 /* If some always_inline functions was inlined, apply the changes.
2700 This way we will not account always inline into growth limits and
2701 moreover we will inline calls from always inlines that we skipped
2702 previously becuase of conditional above. */
2705 timevar_push (TV_INTEGRATION
);
2706 todo
|= optimize_inline_calls (current_function_decl
);
2707 /* optimize_inline_calls call above might have introduced new
2708 statements that don't have inline parameters computed. */
2709 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
2711 if (inline_edge_summary_vec
.length () > (unsigned) edge
->uid
)
2713 struct inline_edge_summary
*es
= inline_edge_summary (edge
);
2715 = estimate_num_insns (edge
->call_stmt
, &eni_size_weights
);
2717 = estimate_num_insns (edge
->call_stmt
, &eni_time_weights
);
2720 inline_update_overall_summary (node
);
2722 timevar_pop (TV_INTEGRATION
);
2724 /* We iterate incremental inlining to get trivial cases of indirect
2726 while (iterations
< PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS
)
2727 && early_inline_small_functions (node
))
2729 timevar_push (TV_INTEGRATION
);
2730 todo
|= optimize_inline_calls (current_function_decl
);
2732 /* Technically we ought to recompute inline parameters so the new
2733 iteration of early inliner works as expected. We however have
2734 values approximately right and thus we only need to update edge
2735 info that might be cleared out for newly discovered edges. */
2736 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
2738 /* We have no summary for new bound store calls yet. */
2739 if (inline_edge_summary_vec
.length () > (unsigned)edge
->uid
)
2741 struct inline_edge_summary
*es
= inline_edge_summary (edge
);
2743 = estimate_num_insns (edge
->call_stmt
, &eni_size_weights
);
2745 = estimate_num_insns (edge
->call_stmt
, &eni_time_weights
);
2747 if (edge
->callee
->decl
2748 && !gimple_check_call_matching_types (
2749 edge
->call_stmt
, edge
->callee
->decl
, false))
2750 edge
->call_stmt_cannot_inline_p
= true;
2752 if (iterations
< PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS
) - 1)
2753 inline_update_overall_summary (node
);
2754 timevar_pop (TV_INTEGRATION
);
2759 fprintf (dump_file
, "Iterations: %i\n", iterations
);
2764 timevar_push (TV_INTEGRATION
);
2765 todo
|= optimize_inline_calls (current_function_decl
);
2766 timevar_pop (TV_INTEGRATION
);
2769 fun
->always_inline_functions_inlined
= true;
2774 /* Do inlining of small functions. Doing so early helps profiling and other
2775 passes to be somewhat more effective and avoids some code duplication in
2776 later real inlining pass for testcases with very many function calls. */
2780 const pass_data pass_data_early_inline
=
2782 GIMPLE_PASS
, /* type */
2783 "einline", /* name */
2784 OPTGROUP_INLINE
, /* optinfo_flags */
2785 TV_EARLY_INLINING
, /* tv_id */
2786 PROP_ssa
, /* properties_required */
2787 0, /* properties_provided */
2788 0, /* properties_destroyed */
2789 0, /* todo_flags_start */
2790 0, /* todo_flags_finish */
2793 class pass_early_inline
: public gimple_opt_pass
2796 pass_early_inline (gcc::context
*ctxt
)
2797 : gimple_opt_pass (pass_data_early_inline
, ctxt
)
2800 /* opt_pass methods: */
2801 virtual unsigned int execute (function
*);
2803 }; // class pass_early_inline
2806 pass_early_inline::execute (function
*fun
)
2808 return early_inliner (fun
);
2814 make_pass_early_inline (gcc::context
*ctxt
)
2816 return new pass_early_inline (ctxt
);
2821 const pass_data pass_data_ipa_inline
=
2823 IPA_PASS
, /* type */
2824 "inline", /* name */
2825 OPTGROUP_INLINE
, /* optinfo_flags */
2826 TV_IPA_INLINING
, /* tv_id */
2827 0, /* properties_required */
2828 0, /* properties_provided */
2829 0, /* properties_destroyed */
2830 0, /* todo_flags_start */
2831 ( TODO_dump_symtab
), /* todo_flags_finish */
2834 class pass_ipa_inline
: public ipa_opt_pass_d
2837 pass_ipa_inline (gcc::context
*ctxt
)
2838 : ipa_opt_pass_d (pass_data_ipa_inline
, ctxt
,
2839 inline_generate_summary
, /* generate_summary */
2840 inline_write_summary
, /* write_summary */
2841 inline_read_summary
, /* read_summary */
2842 NULL
, /* write_optimization_summary */
2843 NULL
, /* read_optimization_summary */
2844 NULL
, /* stmt_fixup */
2845 0, /* function_transform_todo_flags_start */
2846 inline_transform
, /* function_transform */
2847 NULL
) /* variable_transform */
2850 /* opt_pass methods: */
2851 virtual unsigned int execute (function
*) { return ipa_inline (); }
2853 }; // class pass_ipa_inline
2858 make_pass_ipa_inline (gcc::context
*ctxt
)
2860 return new pass_ipa_inline (ctxt
);