1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2017 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* Inlining decision heuristics
23 The implementation of inliner is organized as follows:
25 inlining heuristics limits
27 can_inline_edge_p allow to check that particular inlining is allowed
28 by the limits specified by user (allowed function growth, growth and so
31 Functions are inlined when it is obvious the result is profitable (such
32 as functions called once or when inlining reduce code size).
33 In addition to that we perform inlining of small functions and recursive
38 The inliner itself is split into two passes:
42 Simple local inlining pass inlining callees into current function.
43 This pass makes no use of whole unit analysis and thus it can do only
44 very simple decisions based on local properties.
46 The strength of the pass is that it is run in topological order
47 (reverse postorder) on the callgraph. Functions are converted into SSA
48 form just before this pass and optimized subsequently. As a result, the
49 callees of the function seen by the early inliner was already optimized
50 and results of early inlining adds a lot of optimization opportunities
51 for the local optimization.
53 The pass handle the obvious inlining decisions within the compilation
54 unit - inlining auto inline functions, inlining for size and
57 main strength of the pass is the ability to eliminate abstraction
58 penalty in C++ code (via combination of inlining and early
59 optimization) and thus improve quality of analysis done by real IPA
62 Because of lack of whole unit knowledge, the pass can not really make
63 good code size/performance tradeoffs. It however does very simple
64 speculative inlining allowing code size to grow by
65 EARLY_INLINING_INSNS when callee is leaf function. In this case the
66 optimizations performed later are very likely to eliminate the cost.
70 This is the real inliner able to handle inlining with whole program
71 knowledge. It performs following steps:
73 1) inlining of small functions. This is implemented by greedy
74 algorithm ordering all inlinable cgraph edges by their badness and
75 inlining them in this order as long as inline limits allows doing so.
77 This heuristics is not very good on inlining recursive calls. Recursive
78 calls can be inlined with results similar to loop unrolling. To do so,
79 special purpose recursive inliner is executed on function when
80 recursive edge is met as viable candidate.
82 2) Unreachable functions are removed from callgraph. Inlining leads
83 to devirtualization and other modification of callgraph so functions
84 may become unreachable during the process. Also functions declared as
85 extern inline or virtual functions are removed, since after inlining
86 we no longer need the offline bodies.
88 3) Functions called once and not exported from the unit are inlined.
89 This should almost always lead to reduction of code size by eliminating
90 the need for offline copy of the function. */
94 #include "coretypes.h"
100 #include "alloc-pool.h"
101 #include "tree-pass.h"
102 #include "gimple-ssa.h"
104 #include "lto-streamer.h"
105 #include "trans-mem.h"
107 #include "tree-inline.h"
110 #include "symbol-summary.h"
111 #include "tree-vrp.h"
112 #include "ipa-prop.h"
113 #include "ipa-fnsummary.h"
114 #include "ipa-inline.h"
115 #include "ipa-utils.h"
117 #include "auto-profile.h"
118 #include "builtins.h"
119 #include "fibonacci_heap.h"
120 #include "stringpool.h"
124 typedef fibonacci_heap
<sreal
, cgraph_edge
> edge_heap_t
;
125 typedef fibonacci_node
<sreal
, cgraph_edge
> edge_heap_node_t
;
127 /* Statistics we collect about inlining algorithm. */
128 static int overall_size
;
129 static profile_count max_count
;
130 static profile_count spec_rem
;
132 /* Pre-computed constants 1/CGRAPH_FREQ_BASE and 1/100. */
133 static sreal cgraph_freq_base_rec
, percent_rec
;
135 /* Return false when inlining edge E would lead to violating
136 limits on function unit growth or stack usage growth.
138 The relative function body growth limit is present generally
139 to avoid problems with non-linear behavior of the compiler.
140 To allow inlining huge functions into tiny wrapper, the limit
141 is always based on the bigger of the two functions considered.
143 For stack growth limits we always base the growth in stack usage
144 of the callers. We want to prevent applications from segfaulting
145 on stack overflow when functions with huge stack frames gets
149 caller_growth_limits (struct cgraph_edge
*e
)
151 struct cgraph_node
*to
= e
->caller
;
152 struct cgraph_node
*what
= e
->callee
->ultimate_alias_target ();
155 HOST_WIDE_INT stack_size_limit
= 0, inlined_stack
;
156 ipa_fn_summary
*info
, *what_info
, *outer_info
= ipa_fn_summaries
->get (to
);
158 /* Look for function e->caller is inlined to. While doing
159 so work out the largest function body on the way. As
160 described above, we want to base our function growth
161 limits based on that. Not on the self size of the
162 outer function, not on the self size of inline code
163 we immediately inline to. This is the most relaxed
164 interpretation of the rule "do not grow large functions
165 too much in order to prevent compiler from exploding". */
168 info
= ipa_fn_summaries
->get (to
);
169 if (limit
< info
->self_size
)
170 limit
= info
->self_size
;
171 if (stack_size_limit
< info
->estimated_self_stack_size
)
172 stack_size_limit
= info
->estimated_self_stack_size
;
173 if (to
->global
.inlined_to
)
174 to
= to
->callers
->caller
;
179 what_info
= ipa_fn_summaries
->get (what
);
181 if (limit
< what_info
->self_size
)
182 limit
= what_info
->self_size
;
184 limit
+= limit
* PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH
) / 100;
186 /* Check the size after inlining against the function limits. But allow
187 the function to shrink if it went over the limits by forced inlining. */
188 newsize
= estimate_size_after_inlining (to
, e
);
189 if (newsize
>= info
->size
190 && newsize
> PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS
)
193 e
->inline_failed
= CIF_LARGE_FUNCTION_GROWTH_LIMIT
;
197 if (!what_info
->estimated_stack_size
)
200 /* FIXME: Stack size limit often prevents inlining in Fortran programs
201 due to large i/o datastructures used by the Fortran front-end.
202 We ought to ignore this limit when we know that the edge is executed
203 on every invocation of the caller (i.e. its call statement dominates
204 exit block). We do not track this information, yet. */
205 stack_size_limit
+= ((gcov_type
)stack_size_limit
206 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH
) / 100);
208 inlined_stack
= (outer_info
->stack_frame_offset
209 + outer_info
->estimated_self_stack_size
210 + what_info
->estimated_stack_size
);
211 /* Check new stack consumption with stack consumption at the place
213 if (inlined_stack
> stack_size_limit
214 /* If function already has large stack usage from sibling
215 inline call, we can inline, too.
216 This bit overoptimistically assume that we are good at stack
218 && inlined_stack
> info
->estimated_stack_size
219 && inlined_stack
> PARAM_VALUE (PARAM_LARGE_STACK_FRAME
))
221 e
->inline_failed
= CIF_LARGE_STACK_FRAME_GROWTH_LIMIT
;
227 /* Dump info about why inlining has failed. */
230 report_inline_failed_reason (struct cgraph_edge
*e
)
234 fprintf (dump_file
, " not inlinable: %s -> %s, %s\n",
235 e
->caller
->dump_name (),
236 e
->callee
->dump_name (),
237 cgraph_inline_failed_string (e
->inline_failed
));
238 if ((e
->inline_failed
== CIF_TARGET_OPTION_MISMATCH
239 || e
->inline_failed
== CIF_OPTIMIZATION_MISMATCH
)
240 && e
->caller
->lto_file_data
241 && e
->callee
->ultimate_alias_target ()->lto_file_data
)
243 fprintf (dump_file
, " LTO objects: %s, %s\n",
244 e
->caller
->lto_file_data
->file_name
,
245 e
->callee
->ultimate_alias_target ()->lto_file_data
->file_name
);
247 if (e
->inline_failed
== CIF_TARGET_OPTION_MISMATCH
)
248 cl_target_option_print_diff
249 (dump_file
, 2, target_opts_for_fn (e
->caller
->decl
),
250 target_opts_for_fn (e
->callee
->ultimate_alias_target ()->decl
));
251 if (e
->inline_failed
== CIF_OPTIMIZATION_MISMATCH
)
252 cl_optimization_print_diff
253 (dump_file
, 2, opts_for_fn (e
->caller
->decl
),
254 opts_for_fn (e
->callee
->ultimate_alias_target ()->decl
));
258 /* Decide whether sanitizer-related attributes allow inlining. */
261 sanitize_attrs_match_for_inline_p (const_tree caller
, const_tree callee
)
263 if (!caller
|| !callee
)
266 return sanitize_flags_p (SANITIZE_ADDRESS
, caller
)
267 == sanitize_flags_p (SANITIZE_ADDRESS
, callee
);
270 /* Used for flags where it is safe to inline when caller's value is
271 grater than callee's. */
272 #define check_maybe_up(flag) \
273 (opts_for_fn (caller->decl)->x_##flag \
274 != opts_for_fn (callee->decl)->x_##flag \
276 || opts_for_fn (caller->decl)->x_##flag \
277 < opts_for_fn (callee->decl)->x_##flag))
278 /* Used for flags where it is safe to inline when caller's value is
279 smaller than callee's. */
280 #define check_maybe_down(flag) \
281 (opts_for_fn (caller->decl)->x_##flag \
282 != opts_for_fn (callee->decl)->x_##flag \
284 || opts_for_fn (caller->decl)->x_##flag \
285 > opts_for_fn (callee->decl)->x_##flag))
286 /* Used for flags where exact match is needed for correctness. */
287 #define check_match(flag) \
288 (opts_for_fn (caller->decl)->x_##flag \
289 != opts_for_fn (callee->decl)->x_##flag)
291 /* Decide if we can inline the edge and possibly update
292 inline_failed reason.
293 We check whether inlining is possible at all and whether
294 caller growth limits allow doing so.
296 if REPORT is true, output reason to the dump file.
298 if DISREGARD_LIMITS is true, ignore size limits.*/
301 can_inline_edge_p (struct cgraph_edge
*e
, bool report
,
302 bool disregard_limits
= false, bool early
= false)
304 gcc_checking_assert (e
->inline_failed
);
306 if (cgraph_inline_failed_type (e
->inline_failed
) == CIF_FINAL_ERROR
)
309 report_inline_failed_reason (e
);
313 bool inlinable
= true;
314 enum availability avail
;
315 cgraph_node
*caller
= e
->caller
->global
.inlined_to
316 ? e
->caller
->global
.inlined_to
: e
->caller
;
317 cgraph_node
*callee
= e
->callee
->ultimate_alias_target (&avail
, caller
);
318 tree caller_tree
= DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller
->decl
);
320 = callee
? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee
->decl
) : NULL
;
322 if (!callee
->definition
)
324 e
->inline_failed
= CIF_BODY_NOT_AVAILABLE
;
327 if (!early
&& !opt_for_fn (callee
->decl
, optimize
))
329 e
->inline_failed
= CIF_FUNCTION_NOT_OPTIMIZED
;
332 else if (callee
->calls_comdat_local
)
334 e
->inline_failed
= CIF_USES_COMDAT_LOCAL
;
337 else if (avail
<= AVAIL_INTERPOSABLE
)
339 e
->inline_failed
= CIF_OVERWRITABLE
;
342 /* All edges with call_stmt_cannot_inline_p should have inline_failed
343 initialized to one of FINAL_ERROR reasons. */
344 else if (e
->call_stmt_cannot_inline_p
)
346 /* Don't inline if the functions have different EH personalities. */
347 else if (DECL_FUNCTION_PERSONALITY (caller
->decl
)
348 && DECL_FUNCTION_PERSONALITY (callee
->decl
)
349 && (DECL_FUNCTION_PERSONALITY (caller
->decl
)
350 != DECL_FUNCTION_PERSONALITY (callee
->decl
)))
352 e
->inline_failed
= CIF_EH_PERSONALITY
;
355 /* TM pure functions should not be inlined into non-TM_pure
357 else if (is_tm_pure (callee
->decl
) && !is_tm_pure (caller
->decl
))
359 e
->inline_failed
= CIF_UNSPECIFIED
;
362 /* Check compatibility of target optimization options. */
363 else if (!targetm
.target_option
.can_inline_p (caller
->decl
,
366 e
->inline_failed
= CIF_TARGET_OPTION_MISMATCH
;
369 else if (!ipa_fn_summaries
->get (callee
)->inlinable
)
371 e
->inline_failed
= CIF_FUNCTION_NOT_INLINABLE
;
374 /* Don't inline a function with mismatched sanitization attributes. */
375 else if (!sanitize_attrs_match_for_inline_p (caller
->decl
, callee
->decl
))
377 e
->inline_failed
= CIF_ATTRIBUTE_MISMATCH
;
380 /* Check if caller growth allows the inlining. */
381 else if (!DECL_DISREGARD_INLINE_LIMITS (callee
->decl
)
383 && !lookup_attribute ("flatten",
384 DECL_ATTRIBUTES (caller
->decl
))
385 && !caller_growth_limits (e
))
387 /* Don't inline a function with a higher optimization level than the
388 caller. FIXME: this is really just tip of iceberg of handling
389 optimization attribute. */
390 else if (caller_tree
!= callee_tree
)
393 (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
)
394 && lookup_attribute ("always_inline",
395 DECL_ATTRIBUTES (callee
->decl
)));
396 ipa_fn_summary
*caller_info
= ipa_fn_summaries
->get (caller
);
397 ipa_fn_summary
*callee_info
= ipa_fn_summaries
->get (callee
);
399 /* Until GCC 4.9 we did not check the semantics alterning flags
400 bellow and inline across optimization boundry.
401 Enabling checks bellow breaks several packages by refusing
402 to inline library always_inline functions. See PR65873.
403 Disable the check for early inlining for now until better solution
405 if (always_inline
&& early
)
407 /* There are some options that change IL semantics which means
408 we cannot inline in these cases for correctness reason.
409 Not even for always_inline declared functions. */
410 else if (check_match (flag_wrapv
)
411 || check_match (flag_trapv
)
412 || check_match (flag_pcc_struct_return
)
413 /* When caller or callee does FP math, be sure FP codegen flags
415 || ((caller_info
->fp_expressions
&& callee_info
->fp_expressions
)
416 && (check_maybe_up (flag_rounding_math
)
417 || check_maybe_up (flag_trapping_math
)
418 || check_maybe_down (flag_unsafe_math_optimizations
)
419 || check_maybe_down (flag_finite_math_only
)
420 || check_maybe_up (flag_signaling_nans
)
421 || check_maybe_down (flag_cx_limited_range
)
422 || check_maybe_up (flag_signed_zeros
)
423 || check_maybe_down (flag_associative_math
)
424 || check_maybe_down (flag_reciprocal_math
)
425 || check_maybe_down (flag_fp_int_builtin_inexact
)
426 /* Strictly speaking only when the callee contains function
427 calls that may end up setting errno. */
428 || check_maybe_up (flag_errno_math
)))
429 /* We do not want to make code compiled with exceptions to be
430 brought into a non-EH function unless we know that the callee
432 This is tracked by DECL_FUNCTION_PERSONALITY. */
433 || (check_maybe_up (flag_non_call_exceptions
)
434 && DECL_FUNCTION_PERSONALITY (callee
->decl
))
435 || (check_maybe_up (flag_exceptions
)
436 && DECL_FUNCTION_PERSONALITY (callee
->decl
))
437 /* When devirtualization is diabled for callee, it is not safe
438 to inline it as we possibly mangled the type info.
439 Allow early inlining of always inlines. */
440 || (!early
&& check_maybe_down (flag_devirtualize
)))
442 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
445 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
446 else if (always_inline
)
448 /* When user added an attribute to the callee honor it. */
449 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee
->decl
))
450 && opts_for_fn (caller
->decl
) != opts_for_fn (callee
->decl
))
452 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
455 /* If explicit optimize attribute are not used, the mismatch is caused
456 by different command line options used to build different units.
457 Do not care about COMDAT functions - those are intended to be
458 optimized with the optimization flags of module they are used in.
459 Also do not care about mixing up size/speed optimization when
460 DECL_DISREGARD_INLINE_LIMITS is set. */
461 else if ((callee
->merged_comdat
462 && !lookup_attribute ("optimize",
463 DECL_ATTRIBUTES (caller
->decl
)))
464 || DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
466 /* If mismatch is caused by merging two LTO units with different
467 optimizationflags we want to be bit nicer. However never inline
468 if one of functions is not optimized at all. */
469 else if (!opt_for_fn (callee
->decl
, optimize
)
470 || !opt_for_fn (caller
->decl
, optimize
))
472 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
475 /* If callee is optimized for size and caller is not, allow inlining if
476 code shrinks or we are in MAX_INLINE_INSNS_SINGLE limit and callee
477 is inline (and thus likely an unified comdat). This will allow caller
479 else if (opt_for_fn (callee
->decl
, optimize_size
)
480 > opt_for_fn (caller
->decl
, optimize_size
))
482 int growth
= estimate_edge_growth (e
);
484 && (!DECL_DECLARED_INLINE_P (callee
->decl
)
485 && growth
>= MAX (MAX_INLINE_INSNS_SINGLE
,
486 MAX_INLINE_INSNS_AUTO
)))
488 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
492 /* If callee is more aggressively optimized for performance than caller,
493 we generally want to inline only cheap (runtime wise) functions. */
494 else if (opt_for_fn (callee
->decl
, optimize_size
)
495 < opt_for_fn (caller
->decl
, optimize_size
)
496 || (opt_for_fn (callee
->decl
, optimize
)
497 > opt_for_fn (caller
->decl
, optimize
)))
499 if (estimate_edge_time (e
)
500 >= 20 + ipa_call_summaries
->get (e
)->call_stmt_time
)
502 e
->inline_failed
= CIF_OPTIMIZATION_MISMATCH
;
509 if (!inlinable
&& report
)
510 report_inline_failed_reason (e
);
515 /* Return true if the edge E is inlinable during early inlining. */
518 can_early_inline_edge_p (struct cgraph_edge
*e
)
520 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
521 /* Early inliner might get called at WPA stage when IPA pass adds new
522 function. In this case we can not really do any of early inlining
523 because function bodies are missing. */
524 if (cgraph_inline_failed_type (e
->inline_failed
) == CIF_FINAL_ERROR
)
526 if (!gimple_has_body_p (callee
->decl
))
528 e
->inline_failed
= CIF_BODY_NOT_AVAILABLE
;
531 /* In early inliner some of callees may not be in SSA form yet
532 (i.e. the callgraph is cyclic and we did not process
533 the callee by early inliner, yet). We don't have CIF code for this
534 case; later we will re-do the decision in the real inliner. */
535 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e
->caller
->decl
))
536 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee
->decl
)))
539 fprintf (dump_file
, " edge not inlinable: not in SSA form\n");
542 if (!can_inline_edge_p (e
, true, false, true))
548 /* Return number of calls in N. Ignore cheap builtins. */
551 num_calls (struct cgraph_node
*n
)
553 struct cgraph_edge
*e
;
556 for (e
= n
->callees
; e
; e
= e
->next_callee
)
557 if (!is_inexpensive_builtin (e
->callee
->decl
))
563 /* Return true if we are interested in inlining small function. */
566 want_early_inline_function_p (struct cgraph_edge
*e
)
568 bool want_inline
= true;
569 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
571 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
573 /* For AutoFDO, we need to make sure that before profile summary, all
574 hot paths' IR look exactly the same as profiled binary. As a result,
575 in einliner, we will disregard size limit and inline those callsites
577 * inlined in the profiled binary, and
578 * the cloned callee has enough samples to be considered "hot". */
579 else if (flag_auto_profile
&& afdo_callsite_hot_enough_for_early_inline (e
))
581 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
582 && !opt_for_fn (e
->caller
->decl
, flag_inline_small_functions
))
584 e
->inline_failed
= CIF_FUNCTION_NOT_INLINE_CANDIDATE
;
585 report_inline_failed_reason (e
);
590 int growth
= estimate_edge_growth (e
);
595 else if (!e
->maybe_hot_p ()
599 fprintf (dump_file
, " will not early inline: %s->%s, "
600 "call is cold and code would grow by %i\n",
601 e
->caller
->dump_name (),
602 callee
->dump_name (),
606 else if (growth
> PARAM_VALUE (PARAM_EARLY_INLINING_INSNS
))
609 fprintf (dump_file
, " will not early inline: %s->%s, "
610 "growth %i exceeds --param early-inlining-insns\n",
611 e
->caller
->dump_name (),
612 callee
->dump_name (),
616 else if ((n
= num_calls (callee
)) != 0
617 && growth
* (n
+ 1) > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS
))
620 fprintf (dump_file
, " will not early inline: %s->%s, "
621 "growth %i exceeds --param early-inlining-insns "
622 "divided by number of calls\n",
623 e
->caller
->dump_name (),
624 callee
->dump_name (),
632 /* Compute time of the edge->caller + edge->callee execution when inlining
636 compute_uninlined_call_time (struct cgraph_edge
*edge
,
637 sreal uninlined_call_time
)
639 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
640 ? edge
->caller
->global
.inlined_to
643 if (edge
->count
.ipa ().nonzero_p ()
644 && caller
->count
.ipa ().nonzero_p ())
645 uninlined_call_time
*= (sreal
)edge
->count
.ipa ().to_gcov_type ()
646 / caller
->count
.ipa ().to_gcov_type ();
647 if (edge
->frequency ())
648 uninlined_call_time
*= cgraph_freq_base_rec
* edge
->frequency ();
650 uninlined_call_time
= uninlined_call_time
>> 11;
652 sreal caller_time
= ipa_fn_summaries
->get (caller
)->time
;
653 return uninlined_call_time
+ caller_time
;
656 /* Same as compute_uinlined_call_time but compute time when inlining
660 compute_inlined_call_time (struct cgraph_edge
*edge
,
663 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
664 ? edge
->caller
->global
.inlined_to
666 sreal caller_time
= ipa_fn_summaries
->get (caller
)->time
;
668 if (edge
->count
.ipa ().nonzero_p ()
669 && caller
->count
.ipa ().nonzero_p ())
670 time
*= (sreal
)edge
->count
.to_gcov_type () / caller
->count
.to_gcov_type ();
671 if (edge
->frequency ())
672 time
*= cgraph_freq_base_rec
* edge
->frequency ();
676 /* This calculation should match one in ipa-inline-analysis.c
677 (estimate_edge_size_and_time). */
678 time
-= (sreal
) edge
->frequency ()
679 * ipa_call_summaries
->get (edge
)->call_stmt_time
/ CGRAPH_FREQ_BASE
;
682 time
= ((sreal
) 1) >> 8;
683 gcc_checking_assert (time
>= 0);
687 /* Return true if the speedup for inlining E is bigger than
688 PARAM_MAX_INLINE_MIN_SPEEDUP. */
691 big_speedup_p (struct cgraph_edge
*e
)
694 sreal spec_time
= estimate_edge_time (e
, &unspec_time
);
695 sreal time
= compute_uninlined_call_time (e
, unspec_time
);
696 sreal inlined_time
= compute_inlined_call_time (e
, spec_time
);
698 if (time
- inlined_time
699 > (sreal
) (time
* PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP
))
705 /* Return true if we are interested in inlining small function.
706 When REPORT is true, report reason to dump file. */
709 want_inline_small_function_p (struct cgraph_edge
*e
, bool report
)
711 bool want_inline
= true;
712 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
714 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
716 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
717 && !opt_for_fn (e
->caller
->decl
, flag_inline_small_functions
))
719 e
->inline_failed
= CIF_FUNCTION_NOT_INLINE_CANDIDATE
;
722 /* Do fast and conservative check if the function can be good
723 inline candidate. At the moment we allow inline hints to
724 promote non-inline functions to inline and we increase
725 MAX_INLINE_INSNS_SINGLE 16-fold for inline functions. */
726 else if ((!DECL_DECLARED_INLINE_P (callee
->decl
)
727 && (!e
->count
.ipa ().initialized_p () || !e
->maybe_hot_p ()))
728 && ipa_fn_summaries
->get (callee
)->min_size
729 - ipa_call_summaries
->get (e
)->call_stmt_size
730 > MAX (MAX_INLINE_INSNS_SINGLE
, MAX_INLINE_INSNS_AUTO
))
732 e
->inline_failed
= CIF_MAX_INLINE_INSNS_AUTO_LIMIT
;
735 else if ((DECL_DECLARED_INLINE_P (callee
->decl
)
736 || e
->count
.ipa ().nonzero_p ())
737 && ipa_fn_summaries
->get (callee
)->min_size
738 - ipa_call_summaries
->get (e
)->call_stmt_size
739 > 16 * MAX_INLINE_INSNS_SINGLE
)
741 e
->inline_failed
= (DECL_DECLARED_INLINE_P (callee
->decl
)
742 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
743 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT
);
748 int growth
= estimate_edge_growth (e
);
749 ipa_hints hints
= estimate_edge_hints (e
);
750 bool big_speedup
= big_speedup_p (e
);
754 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when
755 hints suggests that inlining given function is very profitable. */
756 else if (DECL_DECLARED_INLINE_P (callee
->decl
)
757 && growth
>= MAX_INLINE_INSNS_SINGLE
759 && !(hints
& (INLINE_HINT_indirect_call
760 | INLINE_HINT_known_hot
761 | INLINE_HINT_loop_iterations
762 | INLINE_HINT_array_index
763 | INLINE_HINT_loop_stride
)))
764 || growth
>= MAX_INLINE_INSNS_SINGLE
* 16))
766 e
->inline_failed
= CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
;
769 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
770 && !opt_for_fn (e
->caller
->decl
, flag_inline_functions
))
772 /* growth_likely_positive is expensive, always test it last. */
773 if (growth
>= MAX_INLINE_INSNS_SINGLE
774 || growth_likely_positive (callee
, growth
))
776 e
->inline_failed
= CIF_NOT_DECLARED_INLINED
;
780 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline
781 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that
782 inlining given function is very profitable. */
783 else if (!DECL_DECLARED_INLINE_P (callee
->decl
)
785 && !(hints
& INLINE_HINT_known_hot
)
786 && growth
>= ((hints
& (INLINE_HINT_indirect_call
787 | INLINE_HINT_loop_iterations
788 | INLINE_HINT_array_index
789 | INLINE_HINT_loop_stride
))
790 ? MAX (MAX_INLINE_INSNS_AUTO
,
791 MAX_INLINE_INSNS_SINGLE
)
792 : MAX_INLINE_INSNS_AUTO
))
794 /* growth_likely_positive is expensive, always test it last. */
795 if (growth
>= MAX_INLINE_INSNS_SINGLE
796 || growth_likely_positive (callee
, growth
))
798 e
->inline_failed
= CIF_MAX_INLINE_INSNS_AUTO_LIMIT
;
802 /* If call is cold, do not inline when function body would grow. */
803 else if (!e
->maybe_hot_p ()
804 && (growth
>= MAX_INLINE_INSNS_SINGLE
805 || growth_likely_positive (callee
, growth
)))
807 e
->inline_failed
= CIF_UNLIKELY_CALL
;
811 if (!want_inline
&& report
)
812 report_inline_failed_reason (e
);
816 /* EDGE is self recursive edge.
817 We hand two cases - when function A is inlining into itself
818 or when function A is being inlined into another inliner copy of function
821 In first case OUTER_NODE points to the toplevel copy of A, while
822 in the second case OUTER_NODE points to the outermost copy of A in B.
824 In both cases we want to be extra selective since
825 inlining the call will just introduce new recursive calls to appear. */
828 want_inline_self_recursive_call_p (struct cgraph_edge
*edge
,
829 struct cgraph_node
*outer_node
,
833 char const *reason
= NULL
;
834 bool want_inline
= true;
835 int caller_freq
= CGRAPH_FREQ_BASE
;
836 int max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO
);
838 if (DECL_DECLARED_INLINE_P (edge
->caller
->decl
))
839 max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH
);
841 if (!edge
->maybe_hot_p ())
843 reason
= "recursive call is cold";
846 else if (!outer_node
->count
.ipa ().nonzero_p ())
848 reason
= "not executed in profile";
851 else if (depth
> max_depth
)
853 reason
= "--param max-inline-recursive-depth exceeded.";
857 if (outer_node
->global
.inlined_to
)
858 caller_freq
= outer_node
->callers
->frequency ();
862 reason
= "function is inlined and unlikely";
868 /* Inlining of self recursive function into copy of itself within other function
869 is transformation similar to loop peeling.
871 Peeling is profitable if we can inline enough copies to make probability
872 of actual call to the self recursive function very small. Be sure that
873 the probability of recursion is small.
875 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
876 This way the expected number of recision is at most max_depth. */
879 int max_prob
= CGRAPH_FREQ_BASE
- ((CGRAPH_FREQ_BASE
+ max_depth
- 1)
882 for (i
= 1; i
< depth
; i
++)
883 max_prob
= max_prob
* max_prob
/ CGRAPH_FREQ_BASE
;
884 if (max_count
.nonzero_p () && edge
->count
.ipa ().nonzero_p ()
885 && (edge
->count
.ipa ().to_gcov_type () * CGRAPH_FREQ_BASE
886 / outer_node
->count
.ipa ().to_gcov_type ()
889 reason
= "profile of recursive call is too large";
892 if (!max_count
.nonzero_p ()
893 && (edge
->frequency () * CGRAPH_FREQ_BASE
/ caller_freq
896 reason
= "frequency of recursive call is too large";
900 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if recursion
901 depth is large. We reduce function call overhead and increase chances that
902 things fit in hardware return predictor.
904 Recursive inlining might however increase cost of stack frame setup
905 actually slowing down functions whose recursion tree is wide rather than
908 Deciding reliably on when to do recursive inlining without profile feedback
909 is tricky. For now we disable recursive inlining when probability of self
912 Recursive inlining of self recursive call within loop also results in large loop
913 depths that generally optimize badly. We may want to throttle down inlining
914 in those cases. In particular this seems to happen in one of libstdc++ rb tree
918 if (max_count
.nonzero_p () && edge
->count
.ipa ().initialized_p ()
919 && (edge
->count
.ipa ().to_gcov_type () * 100
920 / outer_node
->count
.ipa ().to_gcov_type ()
921 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY
)))
923 reason
= "profile of recursive call is too small";
926 else if ((!max_count
.nonzero_p ()
927 || !edge
->count
.ipa ().initialized_p ())
928 && (edge
->frequency () * 100 / caller_freq
929 <= PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY
)))
931 reason
= "frequency of recursive call is too small";
935 if (!want_inline
&& dump_file
)
936 fprintf (dump_file
, " not inlining recursively: %s\n", reason
);
940 /* Return true when NODE has uninlinable caller;
941 set HAS_HOT_CALL if it has hot call.
942 Worker for cgraph_for_node_and_aliases. */
945 check_callers (struct cgraph_node
*node
, void *has_hot_call
)
947 struct cgraph_edge
*e
;
948 for (e
= node
->callers
; e
; e
= e
->next_caller
)
950 if (!opt_for_fn (e
->caller
->decl
, flag_inline_functions_called_once
)
951 || !opt_for_fn (e
->caller
->decl
, optimize
))
953 if (!can_inline_edge_p (e
, true))
955 if (e
->recursive_p ())
957 if (!(*(bool *)has_hot_call
) && e
->maybe_hot_p ())
958 *(bool *)has_hot_call
= true;
963 /* If NODE has a caller, return true. */
966 has_caller_p (struct cgraph_node
*node
, void *data ATTRIBUTE_UNUSED
)
973 /* Decide if inlining NODE would reduce unit size by eliminating
974 the offline copy of function.
975 When COLD is true the cold calls are considered, too. */
978 want_inline_function_to_all_callers_p (struct cgraph_node
*node
, bool cold
)
980 bool has_hot_call
= false;
982 /* Aliases gets inlined along with the function they alias. */
985 /* Already inlined? */
986 if (node
->global
.inlined_to
)
988 /* Does it have callers? */
989 if (!node
->call_for_symbol_and_aliases (has_caller_p
, NULL
, true))
991 /* Inlining into all callers would increase size? */
992 if (estimate_growth (node
) > 0)
994 /* All inlines must be possible. */
995 if (node
->call_for_symbol_and_aliases (check_callers
, &has_hot_call
,
998 if (!cold
&& !has_hot_call
)
1003 /* A cost model driving the inlining heuristics in a way so the edges with
1004 smallest badness are inlined first. After each inlining is performed
1005 the costs of all caller edges of nodes affected are recomputed so the
1006 metrics may accurately depend on values such as number of inlinable callers
1007 of the function or function body size. */
1010 edge_badness (struct cgraph_edge
*edge
, bool dump
)
1014 sreal edge_time
, unspec_edge_time
;
1015 struct cgraph_node
*callee
= edge
->callee
->ultimate_alias_target ();
1016 struct ipa_fn_summary
*callee_info
= ipa_fn_summaries
->get (callee
);
1018 cgraph_node
*caller
= (edge
->caller
->global
.inlined_to
1019 ? edge
->caller
->global
.inlined_to
1022 growth
= estimate_edge_growth (edge
);
1023 edge_time
= estimate_edge_time (edge
, &unspec_edge_time
);
1024 hints
= estimate_edge_hints (edge
);
1025 gcc_checking_assert (edge_time
>= 0);
1026 /* Check that inlined time is better, but tolerate some roundoff issues.
1027 FIXME: When callee profile drops to 0 we account calls more. This
1028 should be fixed by never doing that. */
1029 gcc_checking_assert ((edge_time
- callee_info
->time
).to_int () <= 0
1030 || callee
->count
.ipa ().initialized_p ());
1031 gcc_checking_assert (growth
<= callee_info
->size
);
1035 fprintf (dump_file
, " Badness calculation for %s -> %s\n",
1036 edge
->caller
->dump_name (),
1037 edge
->callee
->dump_name ());
1038 fprintf (dump_file
, " size growth %i, time %f unspec %f ",
1040 edge_time
.to_double (),
1041 unspec_edge_time
.to_double ());
1042 ipa_dump_hints (dump_file
, hints
);
1043 if (big_speedup_p (edge
))
1044 fprintf (dump_file
, " big_speedup");
1045 fprintf (dump_file
, "\n");
1048 /* Always prefer inlining saving code size. */
1051 badness
= (sreal
) (-SREAL_MIN_SIG
+ growth
) << (SREAL_MAX_EXP
/ 256);
1053 fprintf (dump_file
, " %f: Growth %d <= 0\n", badness
.to_double (),
1056 /* Inlining into EXTERNAL functions is not going to change anything unless
1057 they are themselves inlined. */
1058 else if (DECL_EXTERNAL (caller
->decl
))
1061 fprintf (dump_file
, " max: function is external\n");
1062 return sreal::max ();
1064 /* When profile is available. Compute badness as:
1066 time_saved * caller_count
1067 goodness = -------------------------------------------------
1068 growth_of_caller * overall_growth * combined_size
1070 badness = - goodness
1072 Again use negative value to make calls with profile appear hotter
1075 else if (opt_for_fn (caller
->decl
, flag_guess_branch_prob
)
1076 || caller
->count
.ipa ().nonzero_p ())
1078 sreal numerator
, denominator
;
1080 sreal inlined_time
= compute_inlined_call_time (edge
, edge_time
);
1082 numerator
= (compute_uninlined_call_time (edge
, unspec_edge_time
)
1085 numerator
= ((sreal
) 1 >> 8);
1086 if (caller
->count
.ipa ().nonzero_p ())
1087 numerator
*= caller
->count
.ipa ().to_gcov_type ();
1088 else if (caller
->count
.ipa ().initialized_p ())
1089 numerator
= numerator
>> 11;
1090 denominator
= growth
;
1092 overall_growth
= callee_info
->growth
;
1094 /* Look for inliner wrappers of the form:
1100 noninline_callee ();
1102 Withhout panilizing this case, we usually inline noninline_callee
1103 into the inline_caller because overall_growth is small preventing
1104 further inlining of inline_caller.
1106 Penalize only callgraph edges to functions with small overall
1109 if (growth
> overall_growth
1110 /* ... and having only one caller which is not inlined ... */
1111 && callee_info
->single_caller
1112 && !edge
->caller
->global
.inlined_to
1113 /* ... and edges executed only conditionally ... */
1114 && edge
->frequency () < CGRAPH_FREQ_BASE
1115 /* ... consider case where callee is not inline but caller is ... */
1116 && ((!DECL_DECLARED_INLINE_P (edge
->callee
->decl
)
1117 && DECL_DECLARED_INLINE_P (caller
->decl
))
1118 /* ... or when early optimizers decided to split and edge
1119 frequency still indicates splitting is a win ... */
1120 || (callee
->split_part
&& !caller
->split_part
1121 && edge
->frequency ()
1124 (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY
) / 100
1125 /* ... and do not overwrite user specified hints. */
1126 && (!DECL_DECLARED_INLINE_P (edge
->callee
->decl
)
1127 || DECL_DECLARED_INLINE_P (caller
->decl
)))))
1129 struct ipa_fn_summary
*caller_info
= ipa_fn_summaries
->get (caller
);
1130 int caller_growth
= caller_info
->growth
;
1132 /* Only apply the penalty when caller looks like inline candidate,
1133 and it is not called once and. */
1134 if (!caller_info
->single_caller
&& overall_growth
< caller_growth
1135 && caller_info
->inlinable
1136 && caller_info
->size
1137 < (DECL_DECLARED_INLINE_P (caller
->decl
)
1138 ? MAX_INLINE_INSNS_SINGLE
: MAX_INLINE_INSNS_AUTO
))
1142 " Wrapper penalty. Increasing growth %i to %i\n",
1143 overall_growth
, caller_growth
);
1144 overall_growth
= caller_growth
;
1147 if (overall_growth
> 0)
1149 /* Strongly preffer functions with few callers that can be inlined
1150 fully. The square root here leads to smaller binaries at average.
1151 Watch however for extreme cases and return to linear function
1152 when growth is large. */
1153 if (overall_growth
< 256)
1154 overall_growth
*= overall_growth
;
1156 overall_growth
+= 256 * 256 - 256;
1157 denominator
*= overall_growth
;
1159 denominator
*= inlined_time
;
1161 badness
= - numerator
/ denominator
;
1166 " %f: guessed profile. frequency %f, count %" PRId64
1167 " caller count %" PRId64
1168 " time w/o inlining %f, time with inlining %f"
1169 " overall growth %i (current) %i (original)"
1170 " %i (compensated)\n",
1171 badness
.to_double (),
1172 (double)edge
->frequency () / CGRAPH_FREQ_BASE
,
1173 edge
->count
.ipa ().initialized_p () ? edge
->count
.ipa ().to_gcov_type () : -1,
1174 caller
->count
.ipa ().initialized_p () ? caller
->count
.ipa ().to_gcov_type () : -1,
1175 compute_uninlined_call_time (edge
,
1176 unspec_edge_time
).to_double (),
1177 compute_inlined_call_time (edge
, edge_time
).to_double (),
1178 estimate_growth (callee
),
1179 callee_info
->growth
, overall_growth
);
1182 /* When function local profile is not available or it does not give
1183 useful information (ie frequency is zero), base the cost on
1184 loop nest and overall size growth, so we optimize for overall number
1185 of functions fully inlined in program. */
1188 int nest
= MIN (ipa_call_summaries
->get (edge
)->loop_depth
, 8);
1191 /* Decrease badness if call is nested. */
1193 badness
= badness
>> nest
;
1195 badness
= badness
<< nest
;
1197 fprintf (dump_file
, " %f: no profile. nest %i\n",
1198 badness
.to_double (), nest
);
1200 gcc_checking_assert (badness
!= 0);
1202 if (edge
->recursive_p ())
1203 badness
= badness
.shift (badness
> 0 ? 4 : -4);
1204 if ((hints
& (INLINE_HINT_indirect_call
1205 | INLINE_HINT_loop_iterations
1206 | INLINE_HINT_array_index
1207 | INLINE_HINT_loop_stride
))
1208 || callee_info
->growth
<= 0)
1209 badness
= badness
.shift (badness
> 0 ? -2 : 2);
1210 if (hints
& (INLINE_HINT_same_scc
))
1211 badness
= badness
.shift (badness
> 0 ? 3 : -3);
1212 else if (hints
& (INLINE_HINT_in_scc
))
1213 badness
= badness
.shift (badness
> 0 ? 2 : -2);
1214 else if (hints
& (INLINE_HINT_cross_module
))
1215 badness
= badness
.shift (badness
> 0 ? 1 : -1);
1216 if (DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
1217 badness
= badness
.shift (badness
> 0 ? -4 : 4);
1218 else if ((hints
& INLINE_HINT_declared_inline
))
1219 badness
= badness
.shift (badness
> 0 ? -3 : 3);
1221 fprintf (dump_file
, " Adjusted by hints %f\n", badness
.to_double ());
1225 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1227 update_edge_key (edge_heap_t
*heap
, struct cgraph_edge
*edge
)
1229 sreal badness
= edge_badness (edge
, false);
1232 edge_heap_node_t
*n
= (edge_heap_node_t
*) edge
->aux
;
1233 gcc_checking_assert (n
->get_data () == edge
);
1235 /* fibonacci_heap::replace_key does busy updating of the
1236 heap that is unnecesarily expensive.
1237 We do lazy increases: after extracting minimum if the key
1238 turns out to be out of date, it is re-inserted into heap
1239 with correct value. */
1240 if (badness
< n
->get_key ())
1242 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1245 " decreasing badness %s -> %s, %f to %f\n",
1246 edge
->caller
->dump_name (),
1247 edge
->callee
->dump_name (),
1248 n
->get_key ().to_double (),
1249 badness
.to_double ());
1251 heap
->decrease_key (n
, badness
);
1256 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1259 " enqueuing call %s -> %s, badness %f\n",
1260 edge
->caller
->dump_name (),
1261 edge
->callee
->dump_name (),
1262 badness
.to_double ());
1264 edge
->aux
= heap
->insert (badness
, edge
);
1269 /* NODE was inlined.
1270 All caller edges needs to be resetted because
1271 size estimates change. Similarly callees needs reset
1272 because better context may be known. */
1275 reset_edge_caches (struct cgraph_node
*node
)
1277 struct cgraph_edge
*edge
;
1278 struct cgraph_edge
*e
= node
->callees
;
1279 struct cgraph_node
*where
= node
;
1280 struct ipa_ref
*ref
;
1282 if (where
->global
.inlined_to
)
1283 where
= where
->global
.inlined_to
;
1285 for (edge
= where
->callers
; edge
; edge
= edge
->next_caller
)
1286 if (edge
->inline_failed
)
1287 reset_edge_growth_cache (edge
);
1289 FOR_EACH_ALIAS (where
, ref
)
1290 reset_edge_caches (dyn_cast
<cgraph_node
*> (ref
->referring
));
1296 if (!e
->inline_failed
&& e
->callee
->callees
)
1297 e
= e
->callee
->callees
;
1300 if (e
->inline_failed
)
1301 reset_edge_growth_cache (e
);
1308 if (e
->caller
== node
)
1310 e
= e
->caller
->callers
;
1312 while (!e
->next_callee
);
1318 /* Recompute HEAP nodes for each of caller of NODE.
1319 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1320 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1321 it is inlinable. Otherwise check all edges. */
1324 update_caller_keys (edge_heap_t
*heap
, struct cgraph_node
*node
,
1325 bitmap updated_nodes
,
1326 struct cgraph_edge
*check_inlinablity_for
)
1328 struct cgraph_edge
*edge
;
1329 struct ipa_ref
*ref
;
1331 if ((!node
->alias
&& !ipa_fn_summaries
->get (node
)->inlinable
)
1332 || node
->global
.inlined_to
)
1334 if (!bitmap_set_bit (updated_nodes
, node
->uid
))
1337 FOR_EACH_ALIAS (node
, ref
)
1339 struct cgraph_node
*alias
= dyn_cast
<cgraph_node
*> (ref
->referring
);
1340 update_caller_keys (heap
, alias
, updated_nodes
, check_inlinablity_for
);
1343 for (edge
= node
->callers
; edge
; edge
= edge
->next_caller
)
1344 if (edge
->inline_failed
)
1346 if (!check_inlinablity_for
1347 || check_inlinablity_for
== edge
)
1349 if (can_inline_edge_p (edge
, false)
1350 && want_inline_small_function_p (edge
, false))
1351 update_edge_key (heap
, edge
);
1354 report_inline_failed_reason (edge
);
1355 heap
->delete_node ((edge_heap_node_t
*) edge
->aux
);
1360 update_edge_key (heap
, edge
);
1364 /* Recompute HEAP nodes for each uninlined call in NODE.
1365 This is used when we know that edge badnesses are going only to increase
1366 (we introduced new call site) and thus all we need is to insert newly
1367 created edges into heap. */
1370 update_callee_keys (edge_heap_t
*heap
, struct cgraph_node
*node
,
1371 bitmap updated_nodes
)
1373 struct cgraph_edge
*e
= node
->callees
;
1378 if (!e
->inline_failed
&& e
->callee
->callees
)
1379 e
= e
->callee
->callees
;
1382 enum availability avail
;
1383 struct cgraph_node
*callee
;
1384 /* We do not reset callee growth cache here. Since we added a new call,
1385 growth chould have just increased and consequentely badness metric
1386 don't need updating. */
1387 if (e
->inline_failed
1388 && (callee
= e
->callee
->ultimate_alias_target (&avail
, e
->caller
))
1389 && ipa_fn_summaries
->get (callee
)->inlinable
1390 && avail
>= AVAIL_AVAILABLE
1391 && !bitmap_bit_p (updated_nodes
, callee
->uid
))
1393 if (can_inline_edge_p (e
, false)
1394 && want_inline_small_function_p (e
, false))
1395 update_edge_key (heap
, e
);
1398 report_inline_failed_reason (e
);
1399 heap
->delete_node ((edge_heap_node_t
*) e
->aux
);
1409 if (e
->caller
== node
)
1411 e
= e
->caller
->callers
;
1413 while (!e
->next_callee
);
1419 /* Enqueue all recursive calls from NODE into priority queue depending on
1420 how likely we want to recursively inline the call. */
1423 lookup_recursive_calls (struct cgraph_node
*node
, struct cgraph_node
*where
,
1426 struct cgraph_edge
*e
;
1427 enum availability avail
;
1429 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1430 if (e
->callee
== node
1431 || (e
->callee
->ultimate_alias_target (&avail
, e
->caller
) == node
1432 && avail
> AVAIL_INTERPOSABLE
))
1434 /* When profile feedback is available, prioritize by expected number
1436 heap
->insert (!(max_count
> 0) || !e
->count
.ipa ().initialized_p () ? -e
->frequency ()
1437 : -(e
->count
.ipa ().to_gcov_type ()
1438 / ((max_count
.to_gcov_type () + (1<<24) - 1)
1442 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1443 if (!e
->inline_failed
)
1444 lookup_recursive_calls (node
, e
->callee
, heap
);
1447 /* Decide on recursive inlining: in the case function has recursive calls,
1448 inline until body size reaches given argument. If any new indirect edges
1449 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1453 recursive_inlining (struct cgraph_edge
*edge
,
1454 vec
<cgraph_edge
*> *new_edges
)
1456 int limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO
);
1457 edge_heap_t
heap (sreal::min ());
1458 struct cgraph_node
*node
;
1459 struct cgraph_edge
*e
;
1460 struct cgraph_node
*master_clone
= NULL
, *next
;
1464 node
= edge
->caller
;
1465 if (node
->global
.inlined_to
)
1466 node
= node
->global
.inlined_to
;
1468 if (DECL_DECLARED_INLINE_P (node
->decl
))
1469 limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE
);
1471 /* Make sure that function is small enough to be considered for inlining. */
1472 if (estimate_size_after_inlining (node
, edge
) >= limit
)
1474 lookup_recursive_calls (node
, node
, &heap
);
1480 " Performing recursive inlining on %s\n",
1483 /* Do the inlining and update list of recursive call during process. */
1484 while (!heap
.empty ())
1486 struct cgraph_edge
*curr
= heap
.extract_min ();
1487 struct cgraph_node
*cnode
, *dest
= curr
->callee
;
1489 if (!can_inline_edge_p (curr
, true))
1492 /* MASTER_CLONE is produced in the case we already started modified
1493 the function. Be sure to redirect edge to the original body before
1494 estimating growths otherwise we will be seeing growths after inlining
1495 the already modified body. */
1498 curr
->redirect_callee (master_clone
);
1499 reset_edge_growth_cache (curr
);
1502 if (estimate_size_after_inlining (node
, curr
) > limit
)
1504 curr
->redirect_callee (dest
);
1505 reset_edge_growth_cache (curr
);
1510 for (cnode
= curr
->caller
;
1511 cnode
->global
.inlined_to
; cnode
= cnode
->callers
->caller
)
1513 == curr
->callee
->ultimate_alias_target ()->decl
)
1516 if (!want_inline_self_recursive_call_p (curr
, node
, false, depth
))
1518 curr
->redirect_callee (dest
);
1519 reset_edge_growth_cache (curr
);
1526 " Inlining call of depth %i", depth
);
1527 if (node
->count
.nonzero_p ())
1529 fprintf (dump_file
, " called approx. %.2f times per call",
1530 (double)curr
->count
.to_gcov_type ()
1531 / node
->count
.to_gcov_type ());
1533 fprintf (dump_file
, "\n");
1537 /* We need original clone to copy around. */
1538 master_clone
= node
->create_clone (node
->decl
, node
->count
,
1539 false, vNULL
, true, NULL
, NULL
);
1540 for (e
= master_clone
->callees
; e
; e
= e
->next_callee
)
1541 if (!e
->inline_failed
)
1542 clone_inlined_nodes (e
, true, false, NULL
);
1543 curr
->redirect_callee (master_clone
);
1544 reset_edge_growth_cache (curr
);
1547 inline_call (curr
, false, new_edges
, &overall_size
, true);
1548 lookup_recursive_calls (node
, curr
->callee
, &heap
);
1552 if (!heap
.empty () && dump_file
)
1553 fprintf (dump_file
, " Recursive inlining growth limit met.\n");
1560 "\n Inlined %i times, "
1561 "body grown from size %i to %i, time %f to %f\n", n
,
1562 ipa_fn_summaries
->get (master_clone
)->size
,
1563 ipa_fn_summaries
->get (node
)->size
,
1564 ipa_fn_summaries
->get (master_clone
)->time
.to_double (),
1565 ipa_fn_summaries
->get (node
)->time
.to_double ());
1567 /* Remove master clone we used for inlining. We rely that clones inlined
1568 into master clone gets queued just before master clone so we don't
1570 for (node
= symtab
->first_function (); node
!= master_clone
;
1573 next
= symtab
->next_function (node
);
1574 if (node
->global
.inlined_to
== master_clone
)
1577 master_clone
->remove ();
1582 /* Given whole compilation unit estimate of INSNS, compute how large we can
1583 allow the unit to grow. */
1586 compute_max_insns (int insns
)
1588 int max_insns
= insns
;
1589 if (max_insns
< PARAM_VALUE (PARAM_LARGE_UNIT_INSNS
))
1590 max_insns
= PARAM_VALUE (PARAM_LARGE_UNIT_INSNS
);
1592 return ((int64_t) max_insns
1593 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH
)) / 100);
1597 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1600 add_new_edges_to_heap (edge_heap_t
*heap
, vec
<cgraph_edge
*> new_edges
)
1602 while (new_edges
.length () > 0)
1604 struct cgraph_edge
*edge
= new_edges
.pop ();
1606 gcc_assert (!edge
->aux
);
1607 if (edge
->inline_failed
1608 && can_inline_edge_p (edge
, true)
1609 && want_inline_small_function_p (edge
, true))
1610 edge
->aux
= heap
->insert (edge_badness (edge
, false), edge
);
1614 /* Remove EDGE from the fibheap. */
1617 heap_edge_removal_hook (struct cgraph_edge
*e
, void *data
)
1621 ((edge_heap_t
*)data
)->delete_node ((edge_heap_node_t
*)e
->aux
);
1626 /* Return true if speculation of edge E seems useful.
1627 If ANTICIPATE_INLINING is true, be conservative and hope that E
1631 speculation_useful_p (struct cgraph_edge
*e
, bool anticipate_inlining
)
1633 enum availability avail
;
1634 struct cgraph_node
*target
= e
->callee
->ultimate_alias_target (&avail
,
1636 struct cgraph_edge
*direct
, *indirect
;
1637 struct ipa_ref
*ref
;
1639 gcc_assert (e
->speculative
&& !e
->indirect_unknown_callee
);
1641 if (!e
->maybe_hot_p ())
1644 /* See if IP optimizations found something potentially useful about the
1645 function. For now we look only for CONST/PURE flags. Almost everything
1646 else we propagate is useless. */
1647 if (avail
>= AVAIL_AVAILABLE
)
1649 int ecf_flags
= flags_from_decl_or_type (target
->decl
);
1650 if (ecf_flags
& ECF_CONST
)
1652 e
->speculative_call_info (direct
, indirect
, ref
);
1653 if (!(indirect
->indirect_info
->ecf_flags
& ECF_CONST
))
1656 else if (ecf_flags
& ECF_PURE
)
1658 e
->speculative_call_info (direct
, indirect
, ref
);
1659 if (!(indirect
->indirect_info
->ecf_flags
& ECF_PURE
))
1663 /* If we did not managed to inline the function nor redirect
1664 to an ipa-cp clone (that are seen by having local flag set),
1665 it is probably pointless to inline it unless hardware is missing
1666 indirect call predictor. */
1667 if (!anticipate_inlining
&& e
->inline_failed
&& !target
->local
.local
)
1669 /* For overwritable targets there is not much to do. */
1670 if (e
->inline_failed
&& !can_inline_edge_p (e
, false, true))
1672 /* OK, speculation seems interesting. */
1676 /* We know that EDGE is not going to be inlined.
1677 See if we can remove speculation. */
1680 resolve_noninline_speculation (edge_heap_t
*edge_heap
, struct cgraph_edge
*edge
)
1682 if (edge
->speculative
&& !speculation_useful_p (edge
, false))
1684 struct cgraph_node
*node
= edge
->caller
;
1685 struct cgraph_node
*where
= node
->global
.inlined_to
1686 ? node
->global
.inlined_to
: node
;
1687 auto_bitmap updated_nodes
;
1689 if (edge
->count
.ipa ().initialized_p ())
1690 spec_rem
+= edge
->count
.ipa ();
1691 edge
->resolve_speculation ();
1692 reset_edge_caches (where
);
1693 ipa_update_overall_fn_summary (where
);
1694 update_caller_keys (edge_heap
, where
,
1695 updated_nodes
, NULL
);
1696 update_callee_keys (edge_heap
, where
,
1701 /* Return true if NODE should be accounted for overall size estimate.
1702 Skip all nodes optimized for size so we can measure the growth of hot
1703 part of program no matter of the padding. */
1706 inline_account_function_p (struct cgraph_node
*node
)
1708 return (!DECL_EXTERNAL (node
->decl
)
1709 && !opt_for_fn (node
->decl
, optimize_size
)
1710 && node
->frequency
!= NODE_FREQUENCY_UNLIKELY_EXECUTED
);
1713 /* Count number of callers of NODE and store it into DATA (that
1714 points to int. Worker for cgraph_for_node_and_aliases. */
1717 sum_callers (struct cgraph_node
*node
, void *data
)
1719 struct cgraph_edge
*e
;
1720 int *num_calls
= (int *)data
;
1722 for (e
= node
->callers
; e
; e
= e
->next_caller
)
1727 /* We use greedy algorithm for inlining of small functions:
1728 All inline candidates are put into prioritized heap ordered in
1731 The inlining of small functions is bounded by unit growth parameters. */
1734 inline_small_functions (void)
1736 struct cgraph_node
*node
;
1737 struct cgraph_edge
*edge
;
1738 edge_heap_t
edge_heap (sreal::min ());
1739 auto_bitmap updated_nodes
;
1740 int min_size
, max_size
;
1741 auto_vec
<cgraph_edge
*> new_indirect_edges
;
1742 int initial_size
= 0;
1743 struct cgraph_node
**order
= XCNEWVEC (cgraph_node
*, symtab
->cgraph_count
);
1744 struct cgraph_edge_hook_list
*edge_removal_hook_holder
;
1745 new_indirect_edges
.create (8);
1747 edge_removal_hook_holder
1748 = symtab
->add_edge_removal_hook (&heap_edge_removal_hook
, &edge_heap
);
1750 /* Compute overall unit size and other global parameters used by badness
1753 max_count
= profile_count::uninitialized ();
1754 ipa_reduced_postorder (order
, true, true, NULL
);
1757 FOR_EACH_DEFINED_FUNCTION (node
)
1758 if (!node
->global
.inlined_to
)
1760 if (!node
->alias
&& node
->analyzed
1761 && (node
->has_gimple_body_p () || node
->thunk
.thunk_p
)
1762 && opt_for_fn (node
->decl
, optimize
))
1764 struct ipa_fn_summary
*info
= ipa_fn_summaries
->get (node
);
1765 struct ipa_dfs_info
*dfs
= (struct ipa_dfs_info
*) node
->aux
;
1767 /* Do not account external functions, they will be optimized out
1768 if not inlined. Also only count the non-cold portion of program. */
1769 if (inline_account_function_p (node
))
1770 initial_size
+= info
->size
;
1771 info
->growth
= estimate_growth (node
);
1774 node
->call_for_symbol_and_aliases (sum_callers
, &num_calls
,
1777 info
->single_caller
= true;
1778 if (dfs
&& dfs
->next_cycle
)
1780 struct cgraph_node
*n2
;
1781 int id
= dfs
->scc_no
+ 1;
1783 n2
= ((struct ipa_dfs_info
*) node
->aux
)->next_cycle
)
1784 if (opt_for_fn (n2
->decl
, optimize
))
1786 struct ipa_fn_summary
*info2
= ipa_fn_summaries
->get (n2
);
1794 for (edge
= node
->callers
; edge
; edge
= edge
->next_caller
)
1795 max_count
= max_count
.max (edge
->count
.ipa ());
1797 ipa_free_postorder_info ();
1798 initialize_growth_caches ();
1802 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1805 overall_size
= initial_size
;
1806 max_size
= compute_max_insns (overall_size
);
1807 min_size
= overall_size
;
1809 /* Populate the heap with all edges we might inline. */
1811 FOR_EACH_DEFINED_FUNCTION (node
)
1813 bool update
= false;
1814 struct cgraph_edge
*next
= NULL
;
1815 bool has_speculative
= false;
1817 if (!opt_for_fn (node
->decl
, optimize
))
1821 fprintf (dump_file
, "Enqueueing calls in %s.\n", node
->dump_name ());
1823 for (edge
= node
->callees
; edge
; edge
= next
)
1825 next
= edge
->next_callee
;
1826 if (edge
->inline_failed
1828 && can_inline_edge_p (edge
, true)
1829 && want_inline_small_function_p (edge
, true)
1830 && edge
->inline_failed
)
1832 gcc_assert (!edge
->aux
);
1833 update_edge_key (&edge_heap
, edge
);
1835 if (edge
->speculative
)
1836 has_speculative
= true;
1838 if (has_speculative
)
1839 for (edge
= node
->callees
; edge
; edge
= next
)
1840 if (edge
->speculative
&& !speculation_useful_p (edge
,
1843 edge
->resolve_speculation ();
1848 struct cgraph_node
*where
= node
->global
.inlined_to
1849 ? node
->global
.inlined_to
: node
;
1850 ipa_update_overall_fn_summary (where
);
1851 reset_edge_caches (where
);
1852 update_caller_keys (&edge_heap
, where
,
1853 updated_nodes
, NULL
);
1854 update_callee_keys (&edge_heap
, where
,
1856 bitmap_clear (updated_nodes
);
1860 gcc_assert (in_lto_p
1862 || (profile_info
&& flag_branch_probabilities
));
1864 while (!edge_heap
.empty ())
1866 int old_size
= overall_size
;
1867 struct cgraph_node
*where
, *callee
;
1868 sreal badness
= edge_heap
.min_key ();
1869 sreal current_badness
;
1872 edge
= edge_heap
.extract_min ();
1873 gcc_assert (edge
->aux
);
1875 if (!edge
->inline_failed
|| !edge
->callee
->analyzed
)
1879 /* Be sure that caches are maintained consistent.
1880 This check is affected by scaling roundoff errors when compiling for
1881 IPA this we skip it in that case. */
1882 if (!edge
->callee
->count
.ipa_p ())
1884 sreal cached_badness
= edge_badness (edge
, false);
1886 int old_size_est
= estimate_edge_size (edge
);
1887 sreal old_time_est
= estimate_edge_time (edge
);
1888 int old_hints_est
= estimate_edge_hints (edge
);
1890 reset_edge_growth_cache (edge
);
1891 gcc_assert (old_size_est
== estimate_edge_size (edge
));
1892 gcc_assert (old_time_est
== estimate_edge_time (edge
));
1895 gcc_assert (old_hints_est == estimate_edge_hints (edge));
1897 fails with profile feedback because some hints depends on
1898 maybe_hot_edge_p predicate and because callee gets inlined to other
1899 calls, the edge may become cold.
1900 This ought to be fixed by computing relative probabilities
1901 for given invocation but that will be better done once whole
1902 code is converted to sreals. Disable for now and revert to "wrong"
1903 value so enable/disable checking paths agree. */
1904 edge_growth_cache
[edge
->uid
].hints
= old_hints_est
+ 1;
1906 /* When updating the edge costs, we only decrease badness in the keys.
1907 Increases of badness are handled lazilly; when we see key with out
1908 of date value on it, we re-insert it now. */
1909 current_badness
= edge_badness (edge
, false);
1910 gcc_assert (cached_badness
== current_badness
);
1911 gcc_assert (current_badness
>= badness
);
1914 current_badness
= edge_badness (edge
, false);
1916 if (current_badness
!= badness
)
1918 if (edge_heap
.min () && current_badness
> edge_heap
.min_key ())
1920 edge
->aux
= edge_heap
.insert (current_badness
, edge
);
1924 badness
= current_badness
;
1927 if (!can_inline_edge_p (edge
, true))
1929 resolve_noninline_speculation (&edge_heap
, edge
);
1933 callee
= edge
->callee
->ultimate_alias_target ();
1934 growth
= estimate_edge_growth (edge
);
1938 "\nConsidering %s with %i size\n",
1939 callee
->dump_name (),
1940 ipa_fn_summaries
->get (callee
)->size
);
1942 " to be inlined into %s in %s:%i\n"
1943 " Estimated badness is %f, frequency %.2f.\n",
1944 edge
->caller
->dump_name (),
1946 && (LOCATION_LOCUS (gimple_location ((const gimple
*)
1948 > BUILTINS_LOCATION
)
1949 ? gimple_filename ((const gimple
*) edge
->call_stmt
)
1952 ? gimple_lineno ((const gimple
*) edge
->call_stmt
)
1954 badness
.to_double (),
1955 edge
->frequency () / (double)CGRAPH_FREQ_BASE
);
1956 if (edge
->count
.ipa ().initialized_p ())
1958 fprintf (dump_file
, " Called ");
1959 edge
->count
.ipa ().dump (dump_file
);
1960 fprintf (dump_file
, "times\n");
1962 if (dump_flags
& TDF_DETAILS
)
1963 edge_badness (edge
, true);
1966 if (overall_size
+ growth
> max_size
1967 && !DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
1969 edge
->inline_failed
= CIF_INLINE_UNIT_GROWTH_LIMIT
;
1970 report_inline_failed_reason (edge
);
1971 resolve_noninline_speculation (&edge_heap
, edge
);
1975 if (!want_inline_small_function_p (edge
, true))
1977 resolve_noninline_speculation (&edge_heap
, edge
);
1981 /* Heuristics for inlining small functions work poorly for
1982 recursive calls where we do effects similar to loop unrolling.
1983 When inlining such edge seems profitable, leave decision on
1984 specific inliner. */
1985 if (edge
->recursive_p ())
1987 where
= edge
->caller
;
1988 if (where
->global
.inlined_to
)
1989 where
= where
->global
.inlined_to
;
1990 if (!recursive_inlining (edge
,
1991 opt_for_fn (edge
->caller
->decl
,
1992 flag_indirect_inlining
)
1993 ? &new_indirect_edges
: NULL
))
1995 edge
->inline_failed
= CIF_RECURSIVE_INLINING
;
1996 resolve_noninline_speculation (&edge_heap
, edge
);
1999 reset_edge_caches (where
);
2000 /* Recursive inliner inlines all recursive calls of the function
2001 at once. Consequently we need to update all callee keys. */
2002 if (opt_for_fn (edge
->caller
->decl
, flag_indirect_inlining
))
2003 add_new_edges_to_heap (&edge_heap
, new_indirect_edges
);
2004 update_callee_keys (&edge_heap
, where
, updated_nodes
);
2005 bitmap_clear (updated_nodes
);
2009 struct cgraph_node
*outer_node
= NULL
;
2012 /* Consider the case where self recursive function A is inlined
2013 into B. This is desired optimization in some cases, since it
2014 leads to effect similar of loop peeling and we might completely
2015 optimize out the recursive call. However we must be extra
2018 where
= edge
->caller
;
2019 while (where
->global
.inlined_to
)
2021 if (where
->decl
== callee
->decl
)
2022 outer_node
= where
, depth
++;
2023 where
= where
->callers
->caller
;
2026 && !want_inline_self_recursive_call_p (edge
, outer_node
,
2030 = (DECL_DISREGARD_INLINE_LIMITS (edge
->callee
->decl
)
2031 ? CIF_RECURSIVE_INLINING
: CIF_UNSPECIFIED
);
2032 resolve_noninline_speculation (&edge_heap
, edge
);
2035 else if (depth
&& dump_file
)
2036 fprintf (dump_file
, " Peeling recursion with depth %i\n", depth
);
2038 gcc_checking_assert (!callee
->global
.inlined_to
);
2039 inline_call (edge
, true, &new_indirect_edges
, &overall_size
, true);
2040 add_new_edges_to_heap (&edge_heap
, new_indirect_edges
);
2042 reset_edge_caches (edge
->callee
);
2044 update_callee_keys (&edge_heap
, where
, updated_nodes
);
2046 where
= edge
->caller
;
2047 if (where
->global
.inlined_to
)
2048 where
= where
->global
.inlined_to
;
2050 /* Our profitability metric can depend on local properties
2051 such as number of inlinable calls and size of the function body.
2052 After inlining these properties might change for the function we
2053 inlined into (since it's body size changed) and for the functions
2054 called by function we inlined (since number of it inlinable callers
2056 update_caller_keys (&edge_heap
, where
, updated_nodes
, NULL
);
2057 /* Offline copy count has possibly changed, recompute if profile is
2059 if (max_count
.nonzero_p ())
2061 struct cgraph_node
*n
= cgraph_node::get (edge
->callee
->decl
);
2062 if (n
!= edge
->callee
&& n
->analyzed
)
2063 update_callee_keys (&edge_heap
, n
, updated_nodes
);
2065 bitmap_clear (updated_nodes
);
2070 " Inlined %s into %s which now has time %f and size %i, "
2071 "net change of %+i.\n",
2072 xstrdup_for_dump (edge
->callee
->name ()),
2073 xstrdup_for_dump (edge
->caller
->name ()),
2074 ipa_fn_summaries
->get (edge
->caller
)->time
.to_double (),
2075 ipa_fn_summaries
->get (edge
->caller
)->size
,
2076 overall_size
- old_size
);
2078 if (min_size
> overall_size
)
2080 min_size
= overall_size
;
2081 max_size
= compute_max_insns (min_size
);
2084 fprintf (dump_file
, "New minimal size reached: %i\n", min_size
);
2088 free_growth_caches ();
2091 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2092 initial_size
, overall_size
,
2093 initial_size
? overall_size
* 100 / (initial_size
) - 100: 0);
2094 symtab
->remove_edge_removal_hook (edge_removal_hook_holder
);
2097 /* Flatten NODE. Performed both during early inlining and
2098 at IPA inlining time. */
2101 flatten_function (struct cgraph_node
*node
, bool early
)
2103 struct cgraph_edge
*e
;
2105 /* We shouldn't be called recursively when we are being processed. */
2106 gcc_assert (node
->aux
== NULL
);
2108 node
->aux
= (void *) node
;
2110 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2112 struct cgraph_node
*orig_callee
;
2113 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2115 /* We've hit cycle? It is time to give up. */
2120 "Not inlining %s into %s to avoid cycle.\n",
2121 xstrdup_for_dump (callee
->name ()),
2122 xstrdup_for_dump (e
->caller
->name ()));
2123 e
->inline_failed
= CIF_RECURSIVE_INLINING
;
2127 /* When the edge is already inlined, we just need to recurse into
2128 it in order to fully flatten the leaves. */
2129 if (!e
->inline_failed
)
2131 flatten_function (callee
, early
);
2135 /* Flatten attribute needs to be processed during late inlining. For
2136 extra code quality we however do flattening during early optimization,
2139 ? !can_inline_edge_p (e
, true)
2140 : !can_early_inline_edge_p (e
))
2143 if (e
->recursive_p ())
2146 fprintf (dump_file
, "Not inlining: recursive call.\n");
2150 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node
->decl
))
2151 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee
->decl
)))
2154 fprintf (dump_file
, "Not inlining: SSA form does not match.\n");
2158 /* Inline the edge and flatten the inline clone. Avoid
2159 recursing through the original node if the node was cloned. */
2161 fprintf (dump_file
, " Inlining %s into %s.\n",
2162 xstrdup_for_dump (callee
->name ()),
2163 xstrdup_for_dump (e
->caller
->name ()));
2164 orig_callee
= callee
;
2165 inline_call (e
, true, NULL
, NULL
, false);
2166 if (e
->callee
!= orig_callee
)
2167 orig_callee
->aux
= (void *) node
;
2168 flatten_function (e
->callee
, early
);
2169 if (e
->callee
!= orig_callee
)
2170 orig_callee
->aux
= NULL
;
2174 if (!node
->global
.inlined_to
)
2175 ipa_update_overall_fn_summary (node
);
2178 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2179 DATA points to number of calls originally found so we avoid infinite
2183 inline_to_all_callers_1 (struct cgraph_node
*node
, void *data
,
2184 hash_set
<cgraph_node
*> *callers
)
2186 int *num_calls
= (int *)data
;
2187 bool callee_removed
= false;
2189 while (node
->callers
&& !node
->global
.inlined_to
)
2191 struct cgraph_node
*caller
= node
->callers
->caller
;
2193 if (!can_inline_edge_p (node
->callers
, true)
2194 || node
->callers
->recursive_p ())
2197 fprintf (dump_file
, "Uninlinable call found; giving up.\n");
2205 "\nInlining %s size %i.\n",
2207 ipa_fn_summaries
->get (node
)->size
);
2209 " Called once from %s %i insns.\n",
2210 node
->callers
->caller
->name (),
2211 ipa_fn_summaries
->get (node
->callers
->caller
)->size
);
2214 /* Remember which callers we inlined to, delaying updating the
2216 callers
->add (node
->callers
->caller
);
2217 inline_call (node
->callers
, true, NULL
, NULL
, false, &callee_removed
);
2220 " Inlined into %s which now has %i size\n",
2222 ipa_fn_summaries
->get (caller
)->size
);
2223 if (!(*num_calls
)--)
2226 fprintf (dump_file
, "New calls found; giving up.\n");
2227 return callee_removed
;
2235 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2239 inline_to_all_callers (struct cgraph_node
*node
, void *data
)
2241 hash_set
<cgraph_node
*> callers
;
2242 bool res
= inline_to_all_callers_1 (node
, data
, &callers
);
2243 /* Perform the delayed update of the overall summary of all callers
2244 processed. This avoids quadratic behavior in the cases where
2245 we have a lot of calls to the same function. */
2246 for (hash_set
<cgraph_node
*>::iterator i
= callers
.begin ();
2247 i
!= callers
.end (); ++i
)
2248 ipa_update_overall_fn_summary (*i
);
2252 /* Output overall time estimate. */
2254 dump_overall_stats (void)
2256 sreal sum_weighted
= 0, sum
= 0;
2257 struct cgraph_node
*node
;
2259 FOR_EACH_DEFINED_FUNCTION (node
)
2260 if (!node
->global
.inlined_to
2263 sreal time
= ipa_fn_summaries
->get (node
)->time
;
2265 if (node
->count
.ipa ().initialized_p ())
2266 sum_weighted
+= time
* node
->count
.ipa ().to_gcov_type ();
2268 fprintf (dump_file
, "Overall time estimate: "
2269 "%f weighted by profile: "
2270 "%f\n", sum
.to_double (), sum_weighted
.to_double ());
2273 /* Output some useful stats about inlining. */
2276 dump_inline_stats (void)
2278 int64_t inlined_cnt
= 0, inlined_indir_cnt
= 0;
2279 int64_t inlined_virt_cnt
= 0, inlined_virt_indir_cnt
= 0;
2280 int64_t noninlined_cnt
= 0, noninlined_indir_cnt
= 0;
2281 int64_t noninlined_virt_cnt
= 0, noninlined_virt_indir_cnt
= 0;
2282 int64_t inlined_speculative
= 0, inlined_speculative_ply
= 0;
2283 int64_t indirect_poly_cnt
= 0, indirect_cnt
= 0;
2284 int64_t reason
[CIF_N_REASONS
][3];
2286 struct cgraph_node
*node
;
2288 memset (reason
, 0, sizeof (reason
));
2289 FOR_EACH_DEFINED_FUNCTION (node
)
2291 struct cgraph_edge
*e
;
2292 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2294 if (e
->inline_failed
)
2296 if (e
->count
.ipa ().initialized_p ())
2297 reason
[(int) e
->inline_failed
][0] += e
->count
.ipa ().to_gcov_type ();
2298 reason
[(int) e
->inline_failed
][1] += e
->frequency ();
2299 reason
[(int) e
->inline_failed
][2] ++;
2300 if (DECL_VIRTUAL_P (e
->callee
->decl
)
2301 && e
->count
.ipa ().initialized_p ())
2303 if (e
->indirect_inlining_edge
)
2304 noninlined_virt_indir_cnt
+= e
->count
.ipa ().to_gcov_type ();
2306 noninlined_virt_cnt
+= e
->count
.ipa ().to_gcov_type ();
2308 else if (e
->count
.ipa ().initialized_p ())
2310 if (e
->indirect_inlining_edge
)
2311 noninlined_indir_cnt
+= e
->count
.ipa ().to_gcov_type ();
2313 noninlined_cnt
+= e
->count
.ipa ().to_gcov_type ();
2316 else if (e
->count
.ipa ().initialized_p ())
2320 if (DECL_VIRTUAL_P (e
->callee
->decl
))
2321 inlined_speculative_ply
+= e
->count
.ipa ().to_gcov_type ();
2323 inlined_speculative
+= e
->count
.ipa ().to_gcov_type ();
2325 else if (DECL_VIRTUAL_P (e
->callee
->decl
))
2327 if (e
->indirect_inlining_edge
)
2328 inlined_virt_indir_cnt
+= e
->count
.ipa ().to_gcov_type ();
2330 inlined_virt_cnt
+= e
->count
.ipa ().to_gcov_type ();
2334 if (e
->indirect_inlining_edge
)
2335 inlined_indir_cnt
+= e
->count
.ipa ().to_gcov_type ();
2337 inlined_cnt
+= e
->count
.ipa ().to_gcov_type ();
2341 for (e
= node
->indirect_calls
; e
; e
= e
->next_callee
)
2342 if (e
->indirect_info
->polymorphic
2343 & e
->count
.ipa ().initialized_p ())
2344 indirect_poly_cnt
+= e
->count
.ipa ().to_gcov_type ();
2345 else if (e
->count
.ipa ().initialized_p ())
2346 indirect_cnt
+= e
->count
.ipa ().to_gcov_type ();
2348 if (max_count
.initialized_p ())
2351 "Inlined %" PRId64
" + speculative "
2352 "%" PRId64
" + speculative polymorphic "
2353 "%" PRId64
" + previously indirect "
2354 "%" PRId64
" + virtual "
2355 "%" PRId64
" + virtual and previously indirect "
2356 "%" PRId64
"\n" "Not inlined "
2357 "%" PRId64
" + previously indirect "
2358 "%" PRId64
" + virtual "
2359 "%" PRId64
" + virtual and previously indirect "
2360 "%" PRId64
" + stil indirect "
2361 "%" PRId64
" + still indirect polymorphic "
2362 "%" PRId64
"\n", inlined_cnt
,
2363 inlined_speculative
, inlined_speculative_ply
,
2364 inlined_indir_cnt
, inlined_virt_cnt
, inlined_virt_indir_cnt
,
2365 noninlined_cnt
, noninlined_indir_cnt
, noninlined_virt_cnt
,
2366 noninlined_virt_indir_cnt
, indirect_cnt
, indirect_poly_cnt
);
2367 fprintf (dump_file
, "Removed speculations ");
2368 spec_rem
.dump (dump_file
);
2369 fprintf (dump_file
, "\n");
2371 dump_overall_stats ();
2372 fprintf (dump_file
, "\nWhy inlining failed?\n");
2373 for (i
= 0; i
< CIF_N_REASONS
; i
++)
2375 fprintf (dump_file
, "%-50s: %8i calls, %8i freq, %" PRId64
" count\n",
2376 cgraph_inline_failed_string ((cgraph_inline_failed_t
) i
),
2377 (int) reason
[i
][2], (int) reason
[i
][1], reason
[i
][0]);
2380 /* Decide on the inlining. We do so in the topological order to avoid
2381 expenses on updating data structures. */
2386 struct cgraph_node
*node
;
2388 struct cgraph_node
**order
;
2391 bool remove_functions
= false;
2393 cgraph_freq_base_rec
= (sreal
) 1 / (sreal
) CGRAPH_FREQ_BASE
;
2394 percent_rec
= (sreal
) 1 / (sreal
) 100;
2396 order
= XCNEWVEC (struct cgraph_node
*, symtab
->cgraph_count
);
2399 ipa_dump_fn_summaries (dump_file
);
2401 nnodes
= ipa_reverse_postorder (order
);
2402 spec_rem
= profile_count::zero ();
2404 FOR_EACH_FUNCTION (node
)
2408 /* Recompute the default reasons for inlining because they may have
2409 changed during merging. */
2412 for (cgraph_edge
*e
= node
->callees
; e
; e
= e
->next_callee
)
2414 gcc_assert (e
->inline_failed
);
2415 initialize_inline_failed (e
);
2417 for (cgraph_edge
*e
= node
->indirect_calls
; e
; e
= e
->next_callee
)
2418 initialize_inline_failed (e
);
2423 fprintf (dump_file
, "\nFlattening functions:\n");
2425 /* In the first pass handle functions to be flattened. Do this with
2426 a priority so none of our later choices will make this impossible. */
2427 for (i
= nnodes
- 1; i
>= 0; i
--)
2431 /* Handle nodes to be flattened.
2432 Ideally when processing callees we stop inlining at the
2433 entry of cycles, possibly cloning that entry point and
2434 try to flatten itself turning it into a self-recursive
2436 if (lookup_attribute ("flatten",
2437 DECL_ATTRIBUTES (node
->decl
)) != NULL
)
2441 "Flattening %s\n", node
->name ());
2442 flatten_function (node
, false);
2446 dump_overall_stats ();
2448 inline_small_functions ();
2450 gcc_assert (symtab
->state
== IPA_SSA
);
2451 symtab
->state
= IPA_SSA_AFTER_INLINING
;
2452 /* Do first after-inlining removal. We want to remove all "stale" extern
2453 inline functions and virtual functions so we really know what is called
2455 symtab
->remove_unreachable_nodes (dump_file
);
2458 /* Inline functions with a property that after inlining into all callers the
2459 code size will shrink because the out-of-line copy is eliminated.
2460 We do this regardless on the callee size as long as function growth limits
2464 "\nDeciding on functions to be inlined into all callers and "
2465 "removing useless speculations:\n");
2467 /* Inlining one function called once has good chance of preventing
2468 inlining other function into the same callee. Ideally we should
2469 work in priority order, but probably inlining hot functions first
2470 is good cut without the extra pain of maintaining the queue.
2472 ??? this is not really fitting the bill perfectly: inlining function
2473 into callee often leads to better optimization of callee due to
2474 increased context for optimization.
2475 For example if main() function calls a function that outputs help
2476 and then function that does the main optmization, we should inline
2477 the second with priority even if both calls are cold by themselves.
2479 We probably want to implement new predicate replacing our use of
2480 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2482 for (cold
= 0; cold
<= 1; cold
++)
2484 FOR_EACH_DEFINED_FUNCTION (node
)
2486 struct cgraph_edge
*edge
, *next
;
2489 if (!opt_for_fn (node
->decl
, optimize
)
2490 || !opt_for_fn (node
->decl
, flag_inline_functions_called_once
))
2493 for (edge
= node
->callees
; edge
; edge
= next
)
2495 next
= edge
->next_callee
;
2496 if (edge
->speculative
&& !speculation_useful_p (edge
, false))
2498 if (edge
->count
.ipa ().initialized_p ())
2499 spec_rem
+= edge
->count
.ipa ();
2500 edge
->resolve_speculation ();
2502 remove_functions
= true;
2507 struct cgraph_node
*where
= node
->global
.inlined_to
2508 ? node
->global
.inlined_to
: node
;
2509 reset_edge_caches (where
);
2510 ipa_update_overall_fn_summary (where
);
2512 if (want_inline_function_to_all_callers_p (node
, cold
))
2515 node
->call_for_symbol_and_aliases (sum_callers
, &num_calls
,
2517 while (node
->call_for_symbol_and_aliases
2518 (inline_to_all_callers
, &num_calls
, true))
2520 remove_functions
= true;
2525 /* Free ipa-prop structures if they are no longer needed. */
2526 ipa_free_all_structures_after_iinln ();
2531 "\nInlined %i calls, eliminated %i functions\n\n",
2532 ncalls_inlined
, nfunctions_inlined
);
2533 dump_inline_stats ();
2537 ipa_dump_fn_summaries (dump_file
);
2538 return remove_functions
? TODO_remove_functions
: 0;
2541 /* Inline always-inline function calls in NODE. */
2544 inline_always_inline_functions (struct cgraph_node
*node
)
2546 struct cgraph_edge
*e
;
2547 bool inlined
= false;
2549 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2551 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2552 if (!DECL_DISREGARD_INLINE_LIMITS (callee
->decl
))
2555 if (e
->recursive_p ())
2558 fprintf (dump_file
, " Not inlining recursive call to %s.\n",
2559 e
->callee
->name ());
2560 e
->inline_failed
= CIF_RECURSIVE_INLINING
;
2564 if (!can_early_inline_edge_p (e
))
2566 /* Set inlined to true if the callee is marked "always_inline" but
2567 is not inlinable. This will allow flagging an error later in
2568 expand_call_inline in tree-inline.c. */
2569 if (lookup_attribute ("always_inline",
2570 DECL_ATTRIBUTES (callee
->decl
)) != NULL
)
2576 fprintf (dump_file
, " Inlining %s into %s (always_inline).\n",
2577 xstrdup_for_dump (e
->callee
->name ()),
2578 xstrdup_for_dump (e
->caller
->name ()));
2579 inline_call (e
, true, NULL
, NULL
, false);
2583 ipa_update_overall_fn_summary (node
);
2588 /* Decide on the inlining. We do so in the topological order to avoid
2589 expenses on updating data structures. */
2592 early_inline_small_functions (struct cgraph_node
*node
)
2594 struct cgraph_edge
*e
;
2595 bool inlined
= false;
2597 for (e
= node
->callees
; e
; e
= e
->next_callee
)
2599 struct cgraph_node
*callee
= e
->callee
->ultimate_alias_target ();
2600 if (!ipa_fn_summaries
->get (callee
)->inlinable
2601 || !e
->inline_failed
)
2604 /* Do not consider functions not declared inline. */
2605 if (!DECL_DECLARED_INLINE_P (callee
->decl
)
2606 && !opt_for_fn (node
->decl
, flag_inline_small_functions
)
2607 && !opt_for_fn (node
->decl
, flag_inline_functions
))
2611 fprintf (dump_file
, "Considering inline candidate %s.\n",
2614 if (!can_early_inline_edge_p (e
))
2617 if (e
->recursive_p ())
2620 fprintf (dump_file
, " Not inlining: recursive call.\n");
2624 if (!want_early_inline_function_p (e
))
2628 fprintf (dump_file
, " Inlining %s into %s.\n",
2629 xstrdup_for_dump (callee
->name ()),
2630 xstrdup_for_dump (e
->caller
->name ()));
2631 inline_call (e
, true, NULL
, NULL
, false);
2636 ipa_update_overall_fn_summary (node
);
2642 early_inliner (function
*fun
)
2644 struct cgraph_node
*node
= cgraph_node::get (current_function_decl
);
2645 struct cgraph_edge
*edge
;
2646 unsigned int todo
= 0;
2648 bool inlined
= false;
2653 /* Do nothing if datastructures for ipa-inliner are already computed. This
2654 happens when some pass decides to construct new function and
2655 cgraph_add_new_function calls lowering passes and early optimization on
2656 it. This may confuse ourself when early inliner decide to inline call to
2657 function clone, because function clones don't have parameter list in
2658 ipa-prop matching their signature. */
2659 if (ipa_node_params_sum
)
2664 node
->remove_all_references ();
2666 /* Rebuild this reference because it dosn't depend on
2667 function's body and it's required to pass cgraph_node
2669 if (node
->instrumented_version
2670 && !node
->instrumentation_clone
)
2671 node
->create_reference (node
->instrumented_version
, IPA_REF_CHKP
, NULL
);
2673 /* Even when not optimizing or not inlining inline always-inline
2675 inlined
= inline_always_inline_functions (node
);
2679 || !flag_early_inlining
2680 /* Never inline regular functions into always-inline functions
2681 during incremental inlining. This sucks as functions calling
2682 always inline functions will get less optimized, but at the
2683 same time inlining of functions calling always inline
2684 function into an always inline function might introduce
2685 cycles of edges to be always inlined in the callgraph.
2687 We might want to be smarter and just avoid this type of inlining. */
2688 || (DECL_DISREGARD_INLINE_LIMITS (node
->decl
)
2689 && lookup_attribute ("always_inline",
2690 DECL_ATTRIBUTES (node
->decl
))))
2692 else if (lookup_attribute ("flatten",
2693 DECL_ATTRIBUTES (node
->decl
)) != NULL
)
2695 /* When the function is marked to be flattened, recursively inline
2699 "Flattening %s\n", node
->name ());
2700 flatten_function (node
, true);
2705 /* If some always_inline functions was inlined, apply the changes.
2706 This way we will not account always inline into growth limits and
2707 moreover we will inline calls from always inlines that we skipped
2708 previously because of conditional above. */
2711 timevar_push (TV_INTEGRATION
);
2712 todo
|= optimize_inline_calls (current_function_decl
);
2713 /* optimize_inline_calls call above might have introduced new
2714 statements that don't have inline parameters computed. */
2715 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
2717 struct ipa_call_summary
*es
= ipa_call_summaries
->get (edge
);
2719 = estimate_num_insns (edge
->call_stmt
, &eni_size_weights
);
2721 = estimate_num_insns (edge
->call_stmt
, &eni_time_weights
);
2723 ipa_update_overall_fn_summary (node
);
2725 timevar_pop (TV_INTEGRATION
);
2727 /* We iterate incremental inlining to get trivial cases of indirect
2729 while (iterations
< PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS
)
2730 && early_inline_small_functions (node
))
2732 timevar_push (TV_INTEGRATION
);
2733 todo
|= optimize_inline_calls (current_function_decl
);
2735 /* Technically we ought to recompute inline parameters so the new
2736 iteration of early inliner works as expected. We however have
2737 values approximately right and thus we only need to update edge
2738 info that might be cleared out for newly discovered edges. */
2739 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
2741 /* We have no summary for new bound store calls yet. */
2742 struct ipa_call_summary
*es
= ipa_call_summaries
->get (edge
);
2744 = estimate_num_insns (edge
->call_stmt
, &eni_size_weights
);
2746 = estimate_num_insns (edge
->call_stmt
, &eni_time_weights
);
2748 if (edge
->callee
->decl
2749 && !gimple_check_call_matching_types (
2750 edge
->call_stmt
, edge
->callee
->decl
, false))
2752 edge
->inline_failed
= CIF_MISMATCHED_ARGUMENTS
;
2753 edge
->call_stmt_cannot_inline_p
= true;
2756 if (iterations
< PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS
) - 1)
2757 ipa_update_overall_fn_summary (node
);
2758 timevar_pop (TV_INTEGRATION
);
2763 fprintf (dump_file
, "Iterations: %i\n", iterations
);
2768 timevar_push (TV_INTEGRATION
);
2769 todo
|= optimize_inline_calls (current_function_decl
);
2770 timevar_pop (TV_INTEGRATION
);
2773 fun
->always_inline_functions_inlined
= true;
2778 /* Do inlining of small functions. Doing so early helps profiling and other
2779 passes to be somewhat more effective and avoids some code duplication in
2780 later real inlining pass for testcases with very many function calls. */
2784 const pass_data pass_data_early_inline
=
2786 GIMPLE_PASS
, /* type */
2787 "einline", /* name */
2788 OPTGROUP_INLINE
, /* optinfo_flags */
2789 TV_EARLY_INLINING
, /* tv_id */
2790 PROP_ssa
, /* properties_required */
2791 0, /* properties_provided */
2792 0, /* properties_destroyed */
2793 0, /* todo_flags_start */
2794 0, /* todo_flags_finish */
2797 class pass_early_inline
: public gimple_opt_pass
2800 pass_early_inline (gcc::context
*ctxt
)
2801 : gimple_opt_pass (pass_data_early_inline
, ctxt
)
2804 /* opt_pass methods: */
2805 virtual unsigned int execute (function
*);
2807 }; // class pass_early_inline
2810 pass_early_inline::execute (function
*fun
)
2812 return early_inliner (fun
);
2818 make_pass_early_inline (gcc::context
*ctxt
)
2820 return new pass_early_inline (ctxt
);
2825 const pass_data pass_data_ipa_inline
=
2827 IPA_PASS
, /* type */
2828 "inline", /* name */
2829 OPTGROUP_INLINE
, /* optinfo_flags */
2830 TV_IPA_INLINING
, /* tv_id */
2831 0, /* properties_required */
2832 0, /* properties_provided */
2833 0, /* properties_destroyed */
2834 0, /* todo_flags_start */
2835 ( TODO_dump_symtab
), /* todo_flags_finish */
2838 class pass_ipa_inline
: public ipa_opt_pass_d
2841 pass_ipa_inline (gcc::context
*ctxt
)
2842 : ipa_opt_pass_d (pass_data_ipa_inline
, ctxt
,
2843 NULL
, /* generate_summary */
2844 NULL
, /* write_summary */
2845 NULL
, /* read_summary */
2846 NULL
, /* write_optimization_summary */
2847 NULL
, /* read_optimization_summary */
2848 NULL
, /* stmt_fixup */
2849 0, /* function_transform_todo_flags_start */
2850 inline_transform
, /* function_transform */
2851 NULL
) /* variable_transform */
2854 /* opt_pass methods: */
2855 virtual unsigned int execute (function
*) { return ipa_inline (); }
2857 }; // class pass_ipa_inline
2862 make_pass_ipa_inline (gcc::context
*ctxt
)
2864 return new pass_ipa_inline (ctxt
);