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1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2020 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
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/>. */
20
21 /* Inlining decision heuristics
22
23 The implementation of inliner is organized as follows:
24
25 inlining heuristics limits
26
27 can_inline_edge_p allow to check that particular inlining is allowed
28 by the limits specified by user (allowed function growth, growth and so
29 on).
30
31 Functions are inlined when it is obvious the result is profitable (such
32 as functions called once or when inlining reduce code size).
33 In addition to that we perform inlining of small functions and recursive
34 inlining.
35
36 inlining heuristics
37
38 The inliner itself is split into two passes:
39
40 pass_early_inlining
41
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.
45
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.
52
53 The pass handle the obvious inlining decisions within the compilation
54 unit - inlining auto inline functions, inlining for size and
55 flattening.
56
57 main strength of the pass is the ability to eliminate abstraction
58 penalty in C++ code (via combination of inlining and early
59 optimization) and thus improve quality of analysis done by real IPA
60 optimizers.
61
62 Because of lack of whole unit knowledge, the pass cannot 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.
67
68 pass_ipa_inline
69
70 This is the real inliner able to handle inlining with whole program
71 knowledge. It performs following steps:
72
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.
76
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.
81
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.
87
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. */
91
92 #include "config.h"
93 #include "system.h"
94 #include "coretypes.h"
95 #include "backend.h"
96 #include "target.h"
97 #include "rtl.h"
98 #include "tree.h"
99 #include "gimple.h"
100 #include "alloc-pool.h"
101 #include "tree-pass.h"
102 #include "gimple-ssa.h"
103 #include "cgraph.h"
104 #include "lto-streamer.h"
105 #include "trans-mem.h"
106 #include "calls.h"
107 #include "tree-inline.h"
108 #include "profile.h"
109 #include "symbol-summary.h"
110 #include "tree-vrp.h"
111 #include "ipa-prop.h"
112 #include "ipa-fnsummary.h"
113 #include "ipa-inline.h"
114 #include "ipa-utils.h"
115 #include "sreal.h"
116 #include "auto-profile.h"
117 #include "builtins.h"
118 #include "fibonacci_heap.h"
119 #include "stringpool.h"
120 #include "attribs.h"
121 #include "asan.h"
122
123 typedef fibonacci_heap <sreal, cgraph_edge> edge_heap_t;
124 typedef fibonacci_node <sreal, cgraph_edge> edge_heap_node_t;
125
126 /* Statistics we collect about inlining algorithm. */
127 static int overall_size;
128 static profile_count max_count;
129 static profile_count spec_rem;
130
131 /* Return false when inlining edge E would lead to violating
132 limits on function unit growth or stack usage growth.
133
134 The relative function body growth limit is present generally
135 to avoid problems with non-linear behavior of the compiler.
136 To allow inlining huge functions into tiny wrapper, the limit
137 is always based on the bigger of the two functions considered.
138
139 For stack growth limits we always base the growth in stack usage
140 of the callers. We want to prevent applications from segfaulting
141 on stack overflow when functions with huge stack frames gets
142 inlined. */
143
144 static bool
145 caller_growth_limits (struct cgraph_edge *e)
146 {
147 struct cgraph_node *to = e->caller;
148 struct cgraph_node *what = e->callee->ultimate_alias_target ();
149 int newsize;
150 int limit = 0;
151 HOST_WIDE_INT stack_size_limit = 0, inlined_stack;
152 ipa_size_summary *outer_info = ipa_size_summaries->get (to);
153
154 /* Look for function e->caller is inlined to. While doing
155 so work out the largest function body on the way. As
156 described above, we want to base our function growth
157 limits based on that. Not on the self size of the
158 outer function, not on the self size of inline code
159 we immediately inline to. This is the most relaxed
160 interpretation of the rule "do not grow large functions
161 too much in order to prevent compiler from exploding". */
162 while (true)
163 {
164 ipa_size_summary *size_info = ipa_size_summaries->get (to);
165 if (limit < size_info->self_size)
166 limit = size_info->self_size;
167 if (stack_size_limit < size_info->estimated_self_stack_size)
168 stack_size_limit = size_info->estimated_self_stack_size;
169 if (to->inlined_to)
170 to = to->callers->caller;
171 else
172 break;
173 }
174
175 ipa_fn_summary *what_info = ipa_fn_summaries->get (what);
176 ipa_size_summary *what_size_info = ipa_size_summaries->get (what);
177
178 if (limit < what_size_info->self_size)
179 limit = what_size_info->self_size;
180
181 limit += limit * opt_for_fn (to->decl, param_large_function_growth) / 100;
182
183 /* Check the size after inlining against the function limits. But allow
184 the function to shrink if it went over the limits by forced inlining. */
185 newsize = estimate_size_after_inlining (to, e);
186 if (newsize >= ipa_size_summaries->get (what)->size
187 && newsize > opt_for_fn (to->decl, param_large_function_insns)
188 && newsize > limit)
189 {
190 e->inline_failed = CIF_LARGE_FUNCTION_GROWTH_LIMIT;
191 return false;
192 }
193
194 if (!what_info->estimated_stack_size)
195 return true;
196
197 /* FIXME: Stack size limit often prevents inlining in Fortran programs
198 due to large i/o datastructures used by the Fortran front-end.
199 We ought to ignore this limit when we know that the edge is executed
200 on every invocation of the caller (i.e. its call statement dominates
201 exit block). We do not track this information, yet. */
202 stack_size_limit += ((gcov_type)stack_size_limit
203 * opt_for_fn (to->decl, param_stack_frame_growth)
204 / 100);
205
206 inlined_stack = (ipa_get_stack_frame_offset (to)
207 + outer_info->estimated_self_stack_size
208 + what_info->estimated_stack_size);
209 /* Check new stack consumption with stack consumption at the place
210 stack is used. */
211 if (inlined_stack > stack_size_limit
212 /* If function already has large stack usage from sibling
213 inline call, we can inline, too.
214 This bit overoptimistically assume that we are good at stack
215 packing. */
216 && inlined_stack > ipa_fn_summaries->get (to)->estimated_stack_size
217 && inlined_stack > opt_for_fn (to->decl, param_large_stack_frame))
218 {
219 e->inline_failed = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT;
220 return false;
221 }
222 return true;
223 }
224
225 /* Dump info about why inlining has failed. */
226
227 static void
228 report_inline_failed_reason (struct cgraph_edge *e)
229 {
230 if (dump_enabled_p ())
231 {
232 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
233 " not inlinable: %C -> %C, %s\n",
234 e->caller, e->callee,
235 cgraph_inline_failed_string (e->inline_failed));
236 if ((e->inline_failed == CIF_TARGET_OPTION_MISMATCH
237 || e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
238 && e->caller->lto_file_data
239 && e->callee->ultimate_alias_target ()->lto_file_data)
240 {
241 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
242 " LTO objects: %s, %s\n",
243 e->caller->lto_file_data->file_name,
244 e->callee->ultimate_alias_target ()->lto_file_data->file_name);
245 }
246 if (e->inline_failed == CIF_TARGET_OPTION_MISMATCH)
247 if (dump_file)
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 if (dump_file)
253 cl_optimization_print_diff
254 (dump_file, 2, opts_for_fn (e->caller->decl),
255 opts_for_fn (e->callee->ultimate_alias_target ()->decl));
256 }
257 }
258
259 /* Decide whether sanitizer-related attributes allow inlining. */
260
261 static bool
262 sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
263 {
264 if (!caller || !callee)
265 return true;
266
267 /* Allow inlining always_inline functions into no_sanitize_address
268 functions. */
269 if (!sanitize_flags_p (SANITIZE_ADDRESS, caller)
270 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
271 return true;
272
273 return ((sanitize_flags_p (SANITIZE_ADDRESS, caller)
274 == sanitize_flags_p (SANITIZE_ADDRESS, callee))
275 && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller)
276 == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee))
277 && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller)
278 == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee)));
279 }
280
281 /* Used for flags where it is safe to inline when caller's value is
282 grater than callee's. */
283 #define check_maybe_up(flag) \
284 (opts_for_fn (caller->decl)->x_##flag \
285 != opts_for_fn (callee->decl)->x_##flag \
286 && (!always_inline \
287 || opts_for_fn (caller->decl)->x_##flag \
288 < opts_for_fn (callee->decl)->x_##flag))
289 /* Used for flags where it is safe to inline when caller's value is
290 smaller than callee's. */
291 #define check_maybe_down(flag) \
292 (opts_for_fn (caller->decl)->x_##flag \
293 != opts_for_fn (callee->decl)->x_##flag \
294 && (!always_inline \
295 || opts_for_fn (caller->decl)->x_##flag \
296 > opts_for_fn (callee->decl)->x_##flag))
297 /* Used for flags where exact match is needed for correctness. */
298 #define check_match(flag) \
299 (opts_for_fn (caller->decl)->x_##flag \
300 != opts_for_fn (callee->decl)->x_##flag)
301
302 /* Decide if we can inline the edge and possibly update
303 inline_failed reason.
304 We check whether inlining is possible at all and whether
305 caller growth limits allow doing so.
306
307 if REPORT is true, output reason to the dump file. */
308
309 static bool
310 can_inline_edge_p (struct cgraph_edge *e, bool report,
311 bool early = false)
312 {
313 gcc_checking_assert (e->inline_failed);
314
315 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
316 {
317 if (report)
318 report_inline_failed_reason (e);
319 return false;
320 }
321
322 bool inlinable = true;
323 enum availability avail;
324 cgraph_node *caller = (e->caller->inlined_to
325 ? e->caller->inlined_to : e->caller);
326 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
327
328 if (!callee->definition)
329 {
330 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
331 inlinable = false;
332 }
333 if (!early && (!opt_for_fn (callee->decl, optimize)
334 || !opt_for_fn (caller->decl, optimize)))
335 {
336 e->inline_failed = CIF_FUNCTION_NOT_OPTIMIZED;
337 inlinable = false;
338 }
339 else if (callee->calls_comdat_local)
340 {
341 e->inline_failed = CIF_USES_COMDAT_LOCAL;
342 inlinable = false;
343 }
344 else if (avail <= AVAIL_INTERPOSABLE)
345 {
346 e->inline_failed = CIF_OVERWRITABLE;
347 inlinable = false;
348 }
349 /* All edges with call_stmt_cannot_inline_p should have inline_failed
350 initialized to one of FINAL_ERROR reasons. */
351 else if (e->call_stmt_cannot_inline_p)
352 gcc_unreachable ();
353 /* Don't inline if the functions have different EH personalities. */
354 else if (DECL_FUNCTION_PERSONALITY (caller->decl)
355 && DECL_FUNCTION_PERSONALITY (callee->decl)
356 && (DECL_FUNCTION_PERSONALITY (caller->decl)
357 != DECL_FUNCTION_PERSONALITY (callee->decl)))
358 {
359 e->inline_failed = CIF_EH_PERSONALITY;
360 inlinable = false;
361 }
362 /* TM pure functions should not be inlined into non-TM_pure
363 functions. */
364 else if (is_tm_pure (callee->decl) && !is_tm_pure (caller->decl))
365 {
366 e->inline_failed = CIF_UNSPECIFIED;
367 inlinable = false;
368 }
369 /* Check compatibility of target optimization options. */
370 else if (!targetm.target_option.can_inline_p (caller->decl,
371 callee->decl))
372 {
373 e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
374 inlinable = false;
375 }
376 else if (ipa_fn_summaries->get (callee) == NULL
377 || !ipa_fn_summaries->get (callee)->inlinable)
378 {
379 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
380 inlinable = false;
381 }
382 /* Don't inline a function with mismatched sanitization attributes. */
383 else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
384 {
385 e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
386 inlinable = false;
387 }
388 if (!inlinable && report)
389 report_inline_failed_reason (e);
390 return inlinable;
391 }
392
393 /* Return inlining_insns_single limit for function N. If HINT is true
394 scale up the bound. */
395
396 static int
397 inline_insns_single (cgraph_node *n, bool hint)
398 {
399 if (hint)
400 return opt_for_fn (n->decl, param_max_inline_insns_single)
401 * opt_for_fn (n->decl, param_inline_heuristics_hint_percent) / 100;
402 return opt_for_fn (n->decl, param_max_inline_insns_single);
403 }
404
405 /* Return inlining_insns_auto limit for function N. If HINT is true
406 scale up the bound. */
407
408 static int
409 inline_insns_auto (cgraph_node *n, bool hint)
410 {
411 int max_inline_insns_auto = opt_for_fn (n->decl, param_max_inline_insns_auto);
412 if (hint)
413 return max_inline_insns_auto
414 * opt_for_fn (n->decl, param_inline_heuristics_hint_percent) / 100;
415 return max_inline_insns_auto;
416 }
417
418 /* Decide if we can inline the edge and possibly update
419 inline_failed reason.
420 We check whether inlining is possible at all and whether
421 caller growth limits allow doing so.
422
423 if REPORT is true, output reason to the dump file.
424
425 if DISREGARD_LIMITS is true, ignore size limits. */
426
427 static bool
428 can_inline_edge_by_limits_p (struct cgraph_edge *e, bool report,
429 bool disregard_limits = false, bool early = false)
430 {
431 gcc_checking_assert (e->inline_failed);
432
433 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
434 {
435 if (report)
436 report_inline_failed_reason (e);
437 return false;
438 }
439
440 bool inlinable = true;
441 enum availability avail;
442 cgraph_node *caller = (e->caller->inlined_to
443 ? e->caller->inlined_to : e->caller);
444 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
445 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl);
446 tree callee_tree
447 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL;
448 /* Check if caller growth allows the inlining. */
449 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
450 && !disregard_limits
451 && !lookup_attribute ("flatten",
452 DECL_ATTRIBUTES (caller->decl))
453 && !caller_growth_limits (e))
454 inlinable = false;
455 else if (callee->externally_visible
456 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl)
457 && flag_live_patching == LIVE_PATCHING_INLINE_ONLY_STATIC)
458 {
459 e->inline_failed = CIF_EXTERN_LIVE_ONLY_STATIC;
460 inlinable = false;
461 }
462 /* Don't inline a function with a higher optimization level than the
463 caller. FIXME: this is really just tip of iceberg of handling
464 optimization attribute. */
465 else if (caller_tree != callee_tree)
466 {
467 bool always_inline =
468 (DECL_DISREGARD_INLINE_LIMITS (callee->decl)
469 && lookup_attribute ("always_inline",
470 DECL_ATTRIBUTES (callee->decl)));
471 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
472 ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
473
474 /* Until GCC 4.9 we did not check the semantics-altering flags
475 below and inlined across optimization boundaries.
476 Enabling checks below breaks several packages by refusing
477 to inline library always_inline functions. See PR65873.
478 Disable the check for early inlining for now until better solution
479 is found. */
480 if (always_inline && early)
481 ;
482 /* There are some options that change IL semantics which means
483 we cannot inline in these cases for correctness reason.
484 Not even for always_inline declared functions. */
485 else if (check_match (flag_wrapv)
486 || check_match (flag_trapv)
487 || check_match (flag_pcc_struct_return)
488 /* When caller or callee does FP math, be sure FP codegen flags
489 compatible. */
490 || ((caller_info->fp_expressions && callee_info->fp_expressions)
491 && (check_maybe_up (flag_rounding_math)
492 || check_maybe_up (flag_trapping_math)
493 || check_maybe_down (flag_unsafe_math_optimizations)
494 || check_maybe_down (flag_finite_math_only)
495 || check_maybe_up (flag_signaling_nans)
496 || check_maybe_down (flag_cx_limited_range)
497 || check_maybe_up (flag_signed_zeros)
498 || check_maybe_down (flag_associative_math)
499 || check_maybe_down (flag_reciprocal_math)
500 || check_maybe_down (flag_fp_int_builtin_inexact)
501 /* Strictly speaking only when the callee contains function
502 calls that may end up setting errno. */
503 || check_maybe_up (flag_errno_math)))
504 /* We do not want to make code compiled with exceptions to be
505 brought into a non-EH function unless we know that the callee
506 does not throw.
507 This is tracked by DECL_FUNCTION_PERSONALITY. */
508 || (check_maybe_up (flag_non_call_exceptions)
509 && DECL_FUNCTION_PERSONALITY (callee->decl))
510 || (check_maybe_up (flag_exceptions)
511 && DECL_FUNCTION_PERSONALITY (callee->decl))
512 /* When devirtualization is disabled for callee, it is not safe
513 to inline it as we possibly mangled the type info.
514 Allow early inlining of always inlines. */
515 || (!early && check_maybe_down (flag_devirtualize)))
516 {
517 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
518 inlinable = false;
519 }
520 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
521 else if (always_inline)
522 ;
523 /* When user added an attribute to the callee honor it. */
524 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee->decl))
525 && opts_for_fn (caller->decl) != opts_for_fn (callee->decl))
526 {
527 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
528 inlinable = false;
529 }
530 /* If explicit optimize attribute are not used, the mismatch is caused
531 by different command line options used to build different units.
532 Do not care about COMDAT functions - those are intended to be
533 optimized with the optimization flags of module they are used in.
534 Also do not care about mixing up size/speed optimization when
535 DECL_DISREGARD_INLINE_LIMITS is set. */
536 else if ((callee->merged_comdat
537 && !lookup_attribute ("optimize",
538 DECL_ATTRIBUTES (caller->decl)))
539 || DECL_DISREGARD_INLINE_LIMITS (callee->decl))
540 ;
541 /* If mismatch is caused by merging two LTO units with different
542 optimization flags we want to be bit nicer. However never inline
543 if one of functions is not optimized at all. */
544 else if (!opt_for_fn (callee->decl, optimize)
545 || !opt_for_fn (caller->decl, optimize))
546 {
547 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
548 inlinable = false;
549 }
550 /* If callee is optimized for size and caller is not, allow inlining if
551 code shrinks or we are in param_max_inline_insns_single limit and
552 callee is inline (and thus likely an unified comdat).
553 This will allow caller to run faster. */
554 else if (opt_for_fn (callee->decl, optimize_size)
555 > opt_for_fn (caller->decl, optimize_size))
556 {
557 int growth = estimate_edge_growth (e);
558 if (growth > opt_for_fn (caller->decl, param_max_inline_insns_size)
559 && (!DECL_DECLARED_INLINE_P (callee->decl)
560 && growth >= MAX (inline_insns_single (caller, false),
561 inline_insns_auto (caller, false))))
562 {
563 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
564 inlinable = false;
565 }
566 }
567 /* If callee is more aggressively optimized for performance than caller,
568 we generally want to inline only cheap (runtime wise) functions. */
569 else if (opt_for_fn (callee->decl, optimize_size)
570 < opt_for_fn (caller->decl, optimize_size)
571 || (opt_for_fn (callee->decl, optimize)
572 > opt_for_fn (caller->decl, optimize)))
573 {
574 if (estimate_edge_time (e)
575 >= 20 + ipa_call_summaries->get (e)->call_stmt_time)
576 {
577 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
578 inlinable = false;
579 }
580 }
581
582 }
583
584 if (!inlinable && report)
585 report_inline_failed_reason (e);
586 return inlinable;
587 }
588
589
590 /* Return true if the edge E is inlinable during early inlining. */
591
592 static bool
593 can_early_inline_edge_p (struct cgraph_edge *e)
594 {
595 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
596 /* Early inliner might get called at WPA stage when IPA pass adds new
597 function. In this case we cannot really do any of early inlining
598 because function bodies are missing. */
599 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
600 return false;
601 if (!gimple_has_body_p (callee->decl))
602 {
603 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
604 return false;
605 }
606 /* In early inliner some of callees may not be in SSA form yet
607 (i.e. the callgraph is cyclic and we did not process
608 the callee by early inliner, yet). We don't have CIF code for this
609 case; later we will re-do the decision in the real inliner. */
610 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
611 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
612 {
613 if (dump_enabled_p ())
614 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
615 " edge not inlinable: not in SSA form\n");
616 return false;
617 }
618 if (!can_inline_edge_p (e, true, true)
619 || !can_inline_edge_by_limits_p (e, true, false, true))
620 return false;
621 return true;
622 }
623
624
625 /* Return number of calls in N. Ignore cheap builtins. */
626
627 static int
628 num_calls (struct cgraph_node *n)
629 {
630 struct cgraph_edge *e;
631 int num = 0;
632
633 for (e = n->callees; e; e = e->next_callee)
634 if (!is_inexpensive_builtin (e->callee->decl))
635 num++;
636 return num;
637 }
638
639
640 /* Return true if we are interested in inlining small function. */
641
642 static bool
643 want_early_inline_function_p (struct cgraph_edge *e)
644 {
645 bool want_inline = true;
646 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
647
648 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
649 ;
650 /* For AutoFDO, we need to make sure that before profile summary, all
651 hot paths' IR look exactly the same as profiled binary. As a result,
652 in einliner, we will disregard size limit and inline those callsites
653 that are:
654 * inlined in the profiled binary, and
655 * the cloned callee has enough samples to be considered "hot". */
656 else if (flag_auto_profile && afdo_callsite_hot_enough_for_early_inline (e))
657 ;
658 else if (!DECL_DECLARED_INLINE_P (callee->decl)
659 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
660 {
661 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
662 report_inline_failed_reason (e);
663 want_inline = false;
664 }
665 else
666 {
667 /* First take care of very large functions. */
668 int min_growth = estimate_min_edge_growth (e), growth = 0;
669 int n;
670 int early_inlining_insns = param_early_inlining_insns;
671
672 if (min_growth > early_inlining_insns)
673 {
674 if (dump_enabled_p ())
675 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
676 " will not early inline: %C->%C, "
677 "call is cold and code would grow "
678 "at least by %i\n",
679 e->caller, callee,
680 min_growth);
681 want_inline = false;
682 }
683 else
684 growth = estimate_edge_growth (e);
685
686
687 if (!want_inline || growth <= param_max_inline_insns_size)
688 ;
689 else if (!e->maybe_hot_p ())
690 {
691 if (dump_enabled_p ())
692 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
693 " will not early inline: %C->%C, "
694 "call is cold and code would grow by %i\n",
695 e->caller, callee,
696 growth);
697 want_inline = false;
698 }
699 else if (growth > early_inlining_insns)
700 {
701 if (dump_enabled_p ())
702 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
703 " will not early inline: %C->%C, "
704 "growth %i exceeds --param early-inlining-insns\n",
705 e->caller, callee, growth);
706 want_inline = false;
707 }
708 else if ((n = num_calls (callee)) != 0
709 && growth * (n + 1) > early_inlining_insns)
710 {
711 if (dump_enabled_p ())
712 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
713 " will not early inline: %C->%C, "
714 "growth %i exceeds --param early-inlining-insns "
715 "divided by number of calls\n",
716 e->caller, callee, growth);
717 want_inline = false;
718 }
719 }
720 return want_inline;
721 }
722
723 /* Compute time of the edge->caller + edge->callee execution when inlining
724 does not happen. */
725
726 inline sreal
727 compute_uninlined_call_time (struct cgraph_edge *edge,
728 sreal uninlined_call_time,
729 sreal freq)
730 {
731 cgraph_node *caller = (edge->caller->inlined_to
732 ? edge->caller->inlined_to
733 : edge->caller);
734
735 if (freq > 0)
736 uninlined_call_time *= freq;
737 else
738 uninlined_call_time = uninlined_call_time >> 11;
739
740 sreal caller_time = ipa_fn_summaries->get (caller)->time;
741 return uninlined_call_time + caller_time;
742 }
743
744 /* Same as compute_uinlined_call_time but compute time when inlining
745 does happen. */
746
747 inline sreal
748 compute_inlined_call_time (struct cgraph_edge *edge,
749 sreal time,
750 sreal freq)
751 {
752 cgraph_node *caller = (edge->caller->inlined_to
753 ? edge->caller->inlined_to
754 : edge->caller);
755 sreal caller_time = ipa_fn_summaries->get (caller)->time;
756
757 if (freq > 0)
758 time *= freq;
759 else
760 time = time >> 11;
761
762 /* This calculation should match one in ipa-inline-analysis.c
763 (estimate_edge_size_and_time). */
764 time -= (sreal)ipa_call_summaries->get (edge)->call_stmt_time * freq;
765 time += caller_time;
766 if (time <= 0)
767 time = ((sreal) 1) >> 8;
768 gcc_checking_assert (time >= 0);
769 return time;
770 }
771
772 /* Determine time saved by inlining EDGE of frequency FREQ
773 where callee's runtime w/o inlining is UNINLINED_TYPE
774 and with inlined is INLINED_TYPE. */
775
776 inline sreal
777 inlining_speedup (struct cgraph_edge *edge,
778 sreal freq,
779 sreal uninlined_time,
780 sreal inlined_time)
781 {
782 sreal speedup = uninlined_time - inlined_time;
783 /* Handling of call_time should match one in ipa-inline-fnsummary.c
784 (estimate_edge_size_and_time). */
785 sreal call_time = ipa_call_summaries->get (edge)->call_stmt_time;
786
787 if (freq > 0)
788 {
789 speedup = (speedup + call_time);
790 if (freq != 1)
791 speedup = speedup * freq;
792 }
793 else if (freq == 0)
794 speedup = speedup >> 11;
795 gcc_checking_assert (speedup >= 0);
796 return speedup;
797 }
798
799 /* Return true if the speedup for inlining E is bigger than
800 PARAM_MAX_INLINE_MIN_SPEEDUP. */
801
802 static bool
803 big_speedup_p (struct cgraph_edge *e)
804 {
805 sreal unspec_time;
806 sreal spec_time = estimate_edge_time (e, &unspec_time);
807 sreal freq = e->sreal_frequency ();
808 sreal time = compute_uninlined_call_time (e, unspec_time, freq);
809 sreal inlined_time = compute_inlined_call_time (e, spec_time, freq);
810 cgraph_node *caller = (e->caller->inlined_to
811 ? e->caller->inlined_to
812 : e->caller);
813 int limit = opt_for_fn (caller->decl, param_inline_min_speedup);
814
815 if ((time - inlined_time) * 100 > time * limit)
816 return true;
817 return false;
818 }
819
820 /* Return true if we are interested in inlining small function.
821 When REPORT is true, report reason to dump file. */
822
823 static bool
824 want_inline_small_function_p (struct cgraph_edge *e, bool report)
825 {
826 bool want_inline = true;
827 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
828 cgraph_node *to = (e->caller->inlined_to
829 ? e->caller->inlined_to : e->caller);
830
831 /* Allow this function to be called before can_inline_edge_p,
832 since it's usually cheaper. */
833 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
834 want_inline = false;
835 else if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
836 ;
837 else if (!DECL_DECLARED_INLINE_P (callee->decl)
838 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
839 {
840 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
841 want_inline = false;
842 }
843 /* Do fast and conservative check if the function can be good
844 inline candidate. */
845 else if ((!DECL_DECLARED_INLINE_P (callee->decl)
846 && (!e->count.ipa ().initialized_p () || !e->maybe_hot_p ()))
847 && ipa_fn_summaries->get (callee)->min_size
848 - ipa_call_summaries->get (e)->call_stmt_size
849 > inline_insns_auto (e->caller, true))
850 {
851 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
852 want_inline = false;
853 }
854 else if ((DECL_DECLARED_INLINE_P (callee->decl)
855 || e->count.ipa ().nonzero_p ())
856 && ipa_fn_summaries->get (callee)->min_size
857 - ipa_call_summaries->get (e)->call_stmt_size
858 > inline_insns_single (e->caller, true))
859 {
860 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
861 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
862 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT);
863 want_inline = false;
864 }
865 else
866 {
867 int growth = estimate_edge_growth (e);
868 ipa_hints hints = estimate_edge_hints (e);
869 bool apply_hints = (hints & (INLINE_HINT_indirect_call
870 | INLINE_HINT_known_hot
871 | INLINE_HINT_loop_iterations
872 | INLINE_HINT_loop_stride));
873
874 if (growth <= opt_for_fn (to->decl,
875 param_max_inline_insns_size))
876 ;
877 /* Apply param_max_inline_insns_single limit. Do not do so when
878 hints suggests that inlining given function is very profitable.
879 Avoid computation of big_speedup_p when not necessary to change
880 outcome of decision. */
881 else if (DECL_DECLARED_INLINE_P (callee->decl)
882 && growth >= inline_insns_single (e->caller, apply_hints)
883 && (apply_hints
884 || growth >= inline_insns_single (e->caller, true)
885 || !big_speedup_p (e)))
886 {
887 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
888 want_inline = false;
889 }
890 else if (!DECL_DECLARED_INLINE_P (callee->decl)
891 && !opt_for_fn (e->caller->decl, flag_inline_functions)
892 && growth >= opt_for_fn (to->decl,
893 param_max_inline_insns_small))
894 {
895 /* growth_positive_p is expensive, always test it last. */
896 if (growth >= inline_insns_single (e->caller, false)
897 || growth_positive_p (callee, e, growth))
898 {
899 e->inline_failed = CIF_NOT_DECLARED_INLINED;
900 want_inline = false;
901 }
902 }
903 /* Apply param_max_inline_insns_auto limit for functions not declared
904 inline. Bypass the limit when speedup seems big. */
905 else if (!DECL_DECLARED_INLINE_P (callee->decl)
906 && growth >= inline_insns_auto (e->caller, apply_hints)
907 && (apply_hints
908 || growth >= inline_insns_auto (e->caller, true)
909 || !big_speedup_p (e)))
910 {
911 /* growth_positive_p is expensive, always test it last. */
912 if (growth >= inline_insns_single (e->caller, false)
913 || growth_positive_p (callee, e, growth))
914 {
915 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
916 want_inline = false;
917 }
918 }
919 /* If call is cold, do not inline when function body would grow. */
920 else if (!e->maybe_hot_p ()
921 && (growth >= inline_insns_single (e->caller, false)
922 || growth_positive_p (callee, e, growth)))
923 {
924 e->inline_failed = CIF_UNLIKELY_CALL;
925 want_inline = false;
926 }
927 }
928 if (!want_inline && report)
929 report_inline_failed_reason (e);
930 return want_inline;
931 }
932
933 /* EDGE is self recursive edge.
934 We handle two cases - when function A is inlining into itself
935 or when function A is being inlined into another inliner copy of function
936 A within function B.
937
938 In first case OUTER_NODE points to the toplevel copy of A, while
939 in the second case OUTER_NODE points to the outermost copy of A in B.
940
941 In both cases we want to be extra selective since
942 inlining the call will just introduce new recursive calls to appear. */
943
944 static bool
945 want_inline_self_recursive_call_p (struct cgraph_edge *edge,
946 struct cgraph_node *outer_node,
947 bool peeling,
948 int depth)
949 {
950 char const *reason = NULL;
951 bool want_inline = true;
952 sreal caller_freq = 1;
953 int max_depth = opt_for_fn (outer_node->decl,
954 param_max_inline_recursive_depth_auto);
955
956 if (DECL_DECLARED_INLINE_P (edge->caller->decl))
957 max_depth = opt_for_fn (outer_node->decl,
958 param_max_inline_recursive_depth);
959
960 if (!edge->maybe_hot_p ())
961 {
962 reason = "recursive call is cold";
963 want_inline = false;
964 }
965 else if (depth > max_depth)
966 {
967 reason = "--param max-inline-recursive-depth exceeded.";
968 want_inline = false;
969 }
970 else if (outer_node->inlined_to
971 && (caller_freq = outer_node->callers->sreal_frequency ()) == 0)
972 {
973 reason = "caller frequency is 0";
974 want_inline = false;
975 }
976
977 if (!want_inline)
978 ;
979 /* Inlining of self recursive function into copy of itself within other
980 function is transformation similar to loop peeling.
981
982 Peeling is profitable if we can inline enough copies to make probability
983 of actual call to the self recursive function very small. Be sure that
984 the probability of recursion is small.
985
986 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
987 This way the expected number of recursion is at most max_depth. */
988 else if (peeling)
989 {
990 sreal max_prob = (sreal)1 - ((sreal)1 / (sreal)max_depth);
991 int i;
992 for (i = 1; i < depth; i++)
993 max_prob = max_prob * max_prob;
994 if (edge->sreal_frequency () >= max_prob * caller_freq)
995 {
996 reason = "frequency of recursive call is too large";
997 want_inline = false;
998 }
999 }
1000 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if
1001 recursion depth is large. We reduce function call overhead and increase
1002 chances that things fit in hardware return predictor.
1003
1004 Recursive inlining might however increase cost of stack frame setup
1005 actually slowing down functions whose recursion tree is wide rather than
1006 deep.
1007
1008 Deciding reliably on when to do recursive inlining without profile feedback
1009 is tricky. For now we disable recursive inlining when probability of self
1010 recursion is low.
1011
1012 Recursive inlining of self recursive call within loop also results in
1013 large loop depths that generally optimize badly. We may want to throttle
1014 down inlining in those cases. In particular this seems to happen in one
1015 of libstdc++ rb tree methods. */
1016 else
1017 {
1018 if (edge->sreal_frequency () * 100
1019 <= caller_freq
1020 * opt_for_fn (outer_node->decl,
1021 param_min_inline_recursive_probability))
1022 {
1023 reason = "frequency of recursive call is too small";
1024 want_inline = false;
1025 }
1026 }
1027 if (!want_inline && dump_enabled_p ())
1028 dump_printf_loc (MSG_MISSED_OPTIMIZATION, edge->call_stmt,
1029 " not inlining recursively: %s\n", reason);
1030 return want_inline;
1031 }
1032
1033 /* Return true when NODE has uninlinable caller;
1034 set HAS_HOT_CALL if it has hot call.
1035 Worker for cgraph_for_node_and_aliases. */
1036
1037 static bool
1038 check_callers (struct cgraph_node *node, void *has_hot_call)
1039 {
1040 struct cgraph_edge *e;
1041 for (e = node->callers; e; e = e->next_caller)
1042 {
1043 if (!opt_for_fn (e->caller->decl, flag_inline_functions_called_once)
1044 || !opt_for_fn (e->caller->decl, optimize))
1045 return true;
1046 if (!can_inline_edge_p (e, true))
1047 return true;
1048 if (e->recursive_p ())
1049 return true;
1050 if (!can_inline_edge_by_limits_p (e, true))
1051 return true;
1052 if (!(*(bool *)has_hot_call) && e->maybe_hot_p ())
1053 *(bool *)has_hot_call = true;
1054 }
1055 return false;
1056 }
1057
1058 /* If NODE has a caller, return true. */
1059
1060 static bool
1061 has_caller_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
1062 {
1063 if (node->callers)
1064 return true;
1065 return false;
1066 }
1067
1068 /* Decide if inlining NODE would reduce unit size by eliminating
1069 the offline copy of function.
1070 When COLD is true the cold calls are considered, too. */
1071
1072 static bool
1073 want_inline_function_to_all_callers_p (struct cgraph_node *node, bool cold)
1074 {
1075 bool has_hot_call = false;
1076
1077 /* Aliases gets inlined along with the function they alias. */
1078 if (node->alias)
1079 return false;
1080 /* Already inlined? */
1081 if (node->inlined_to)
1082 return false;
1083 /* Does it have callers? */
1084 if (!node->call_for_symbol_and_aliases (has_caller_p, NULL, true))
1085 return false;
1086 /* Inlining into all callers would increase size? */
1087 if (growth_positive_p (node, NULL, INT_MIN) > 0)
1088 return false;
1089 /* All inlines must be possible. */
1090 if (node->call_for_symbol_and_aliases (check_callers, &has_hot_call,
1091 true))
1092 return false;
1093 if (!cold && !has_hot_call)
1094 return false;
1095 return true;
1096 }
1097
1098 /* Return true if WHERE of SIZE is a possible candidate for wrapper heuristics
1099 in estimate_edge_badness. */
1100
1101 static bool
1102 wrapper_heuristics_may_apply (struct cgraph_node *where, int size)
1103 {
1104 return size < (DECL_DECLARED_INLINE_P (where->decl)
1105 ? inline_insns_single (where, false)
1106 : inline_insns_auto (where, false));
1107 }
1108
1109 /* A cost model driving the inlining heuristics in a way so the edges with
1110 smallest badness are inlined first. After each inlining is performed
1111 the costs of all caller edges of nodes affected are recomputed so the
1112 metrics may accurately depend on values such as number of inlinable callers
1113 of the function or function body size. */
1114
1115 static sreal
1116 edge_badness (struct cgraph_edge *edge, bool dump)
1117 {
1118 sreal badness;
1119 int growth;
1120 sreal edge_time, unspec_edge_time;
1121 struct cgraph_node *callee = edge->callee->ultimate_alias_target ();
1122 class ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
1123 ipa_hints hints;
1124 cgraph_node *caller = (edge->caller->inlined_to
1125 ? edge->caller->inlined_to
1126 : edge->caller);
1127
1128 growth = estimate_edge_growth (edge);
1129 edge_time = estimate_edge_time (edge, &unspec_edge_time);
1130 hints = estimate_edge_hints (edge);
1131 gcc_checking_assert (edge_time >= 0);
1132 /* Check that inlined time is better, but tolerate some roundoff issues.
1133 FIXME: When callee profile drops to 0 we account calls more. This
1134 should be fixed by never doing that. */
1135 gcc_checking_assert ((edge_time * 100
1136 - callee_info->time * 101).to_int () <= 0
1137 || callee->count.ipa ().initialized_p ());
1138 gcc_checking_assert (growth <= ipa_size_summaries->get (callee)->size);
1139
1140 if (dump)
1141 {
1142 fprintf (dump_file, " Badness calculation for %s -> %s\n",
1143 edge->caller->dump_name (),
1144 edge->callee->dump_name ());
1145 fprintf (dump_file, " size growth %i, time %f unspec %f ",
1146 growth,
1147 edge_time.to_double (),
1148 unspec_edge_time.to_double ());
1149 ipa_dump_hints (dump_file, hints);
1150 if (big_speedup_p (edge))
1151 fprintf (dump_file, " big_speedup");
1152 fprintf (dump_file, "\n");
1153 }
1154
1155 /* Always prefer inlining saving code size. */
1156 if (growth <= 0)
1157 {
1158 badness = (sreal) (-SREAL_MIN_SIG + growth) << (SREAL_MAX_EXP / 256);
1159 if (dump)
1160 fprintf (dump_file, " %f: Growth %d <= 0\n", badness.to_double (),
1161 growth);
1162 }
1163 /* Inlining into EXTERNAL functions is not going to change anything unless
1164 they are themselves inlined. */
1165 else if (DECL_EXTERNAL (caller->decl))
1166 {
1167 if (dump)
1168 fprintf (dump_file, " max: function is external\n");
1169 return sreal::max ();
1170 }
1171 /* When profile is available. Compute badness as:
1172
1173 time_saved * caller_count
1174 goodness = -------------------------------------------------
1175 growth_of_caller * overall_growth * combined_size
1176
1177 badness = - goodness
1178
1179 Again use negative value to make calls with profile appear hotter
1180 then calls without.
1181 */
1182 else if (opt_for_fn (caller->decl, flag_guess_branch_prob)
1183 || caller->count.ipa ().nonzero_p ())
1184 {
1185 sreal numerator, denominator;
1186 int overall_growth;
1187 sreal freq = edge->sreal_frequency ();
1188
1189 numerator = inlining_speedup (edge, freq, unspec_edge_time, edge_time);
1190 if (numerator <= 0)
1191 numerator = ((sreal) 1 >> 8);
1192 if (caller->count.ipa ().nonzero_p ())
1193 numerator *= caller->count.ipa ().to_gcov_type ();
1194 else if (caller->count.ipa ().initialized_p ())
1195 numerator = numerator >> 11;
1196 denominator = growth;
1197
1198 overall_growth = callee_info->growth;
1199
1200 /* Look for inliner wrappers of the form:
1201
1202 inline_caller ()
1203 {
1204 do_fast_job...
1205 if (need_more_work)
1206 noninline_callee ();
1207 }
1208 Without penalizing this case, we usually inline noninline_callee
1209 into the inline_caller because overall_growth is small preventing
1210 further inlining of inline_caller.
1211
1212 Penalize only callgraph edges to functions with small overall
1213 growth ...
1214 */
1215 if (growth > overall_growth
1216 /* ... and having only one caller which is not inlined ... */
1217 && callee_info->single_caller
1218 && !edge->caller->inlined_to
1219 /* ... and edges executed only conditionally ... */
1220 && freq < 1
1221 /* ... consider case where callee is not inline but caller is ... */
1222 && ((!DECL_DECLARED_INLINE_P (edge->callee->decl)
1223 && DECL_DECLARED_INLINE_P (caller->decl))
1224 /* ... or when early optimizers decided to split and edge
1225 frequency still indicates splitting is a win ... */
1226 || (callee->split_part && !caller->split_part
1227 && freq * 100
1228 < opt_for_fn (caller->decl,
1229 param_partial_inlining_entry_probability)
1230 /* ... and do not overwrite user specified hints. */
1231 && (!DECL_DECLARED_INLINE_P (edge->callee->decl)
1232 || DECL_DECLARED_INLINE_P (caller->decl)))))
1233 {
1234 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
1235 int caller_growth = caller_info->growth;
1236
1237 /* Only apply the penalty when caller looks like inline candidate,
1238 and it is not called once. */
1239 if (!caller_info->single_caller && overall_growth < caller_growth
1240 && caller_info->inlinable
1241 && wrapper_heuristics_may_apply
1242 (caller, ipa_size_summaries->get (caller)->size))
1243 {
1244 if (dump)
1245 fprintf (dump_file,
1246 " Wrapper penalty. Increasing growth %i to %i\n",
1247 overall_growth, caller_growth);
1248 overall_growth = caller_growth;
1249 }
1250 }
1251 if (overall_growth > 0)
1252 {
1253 /* Strongly prefer functions with few callers that can be inlined
1254 fully. The square root here leads to smaller binaries at average.
1255 Watch however for extreme cases and return to linear function
1256 when growth is large. */
1257 if (overall_growth < 256)
1258 overall_growth *= overall_growth;
1259 else
1260 overall_growth += 256 * 256 - 256;
1261 denominator *= overall_growth;
1262 }
1263 denominator *= ipa_size_summaries->get (caller)->size + growth;
1264
1265 badness = - numerator / denominator;
1266
1267 if (dump)
1268 {
1269 fprintf (dump_file,
1270 " %f: guessed profile. frequency %f, count %" PRId64
1271 " caller count %" PRId64
1272 " time saved %f"
1273 " overall growth %i (current) %i (original)"
1274 " %i (compensated)\n",
1275 badness.to_double (),
1276 freq.to_double (),
1277 edge->count.ipa ().initialized_p () ? edge->count.ipa ().to_gcov_type () : -1,
1278 caller->count.ipa ().initialized_p () ? caller->count.ipa ().to_gcov_type () : -1,
1279 inlining_speedup (edge, freq, unspec_edge_time, edge_time).to_double (),
1280 estimate_growth (callee),
1281 callee_info->growth, overall_growth);
1282 }
1283 }
1284 /* When function local profile is not available or it does not give
1285 useful information (i.e. frequency is zero), base the cost on
1286 loop nest and overall size growth, so we optimize for overall number
1287 of functions fully inlined in program. */
1288 else
1289 {
1290 int nest = MIN (ipa_call_summaries->get (edge)->loop_depth, 8);
1291 badness = growth;
1292
1293 /* Decrease badness if call is nested. */
1294 if (badness > 0)
1295 badness = badness >> nest;
1296 else
1297 badness = badness << nest;
1298 if (dump)
1299 fprintf (dump_file, " %f: no profile. nest %i\n",
1300 badness.to_double (), nest);
1301 }
1302 gcc_checking_assert (badness != 0);
1303
1304 if (edge->recursive_p ())
1305 badness = badness.shift (badness > 0 ? 4 : -4);
1306 if ((hints & (INLINE_HINT_indirect_call
1307 | INLINE_HINT_loop_iterations
1308 | INLINE_HINT_loop_stride))
1309 || callee_info->growth <= 0)
1310 badness = badness.shift (badness > 0 ? -2 : 2);
1311 if (hints & (INLINE_HINT_same_scc))
1312 badness = badness.shift (badness > 0 ? 3 : -3);
1313 else if (hints & (INLINE_HINT_in_scc))
1314 badness = badness.shift (badness > 0 ? 2 : -2);
1315 else if (hints & (INLINE_HINT_cross_module))
1316 badness = badness.shift (badness > 0 ? 1 : -1);
1317 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
1318 badness = badness.shift (badness > 0 ? -4 : 4);
1319 else if ((hints & INLINE_HINT_declared_inline))
1320 badness = badness.shift (badness > 0 ? -3 : 3);
1321 if (dump)
1322 fprintf (dump_file, " Adjusted by hints %f\n", badness.to_double ());
1323 return badness;
1324 }
1325
1326 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1327 static inline void
1328 update_edge_key (edge_heap_t *heap, struct cgraph_edge *edge)
1329 {
1330 sreal badness = edge_badness (edge, false);
1331 if (edge->aux)
1332 {
1333 edge_heap_node_t *n = (edge_heap_node_t *) edge->aux;
1334 gcc_checking_assert (n->get_data () == edge);
1335
1336 /* fibonacci_heap::replace_key does busy updating of the
1337 heap that is unnecessarily expensive.
1338 We do lazy increases: after extracting minimum if the key
1339 turns out to be out of date, it is re-inserted into heap
1340 with correct value. */
1341 if (badness < n->get_key ())
1342 {
1343 if (dump_file && (dump_flags & TDF_DETAILS))
1344 {
1345 fprintf (dump_file,
1346 " decreasing badness %s -> %s, %f to %f\n",
1347 edge->caller->dump_name (),
1348 edge->callee->dump_name (),
1349 n->get_key ().to_double (),
1350 badness.to_double ());
1351 }
1352 heap->decrease_key (n, badness);
1353 }
1354 }
1355 else
1356 {
1357 if (dump_file && (dump_flags & TDF_DETAILS))
1358 {
1359 fprintf (dump_file,
1360 " enqueuing call %s -> %s, badness %f\n",
1361 edge->caller->dump_name (),
1362 edge->callee->dump_name (),
1363 badness.to_double ());
1364 }
1365 edge->aux = heap->insert (badness, edge);
1366 }
1367 }
1368
1369
1370 /* NODE was inlined.
1371 All caller edges needs to be reset because
1372 size estimates change. Similarly callees needs reset
1373 because better context may be known. */
1374
1375 static void
1376 reset_edge_caches (struct cgraph_node *node)
1377 {
1378 struct cgraph_edge *edge;
1379 struct cgraph_edge *e = node->callees;
1380 struct cgraph_node *where = node;
1381 struct ipa_ref *ref;
1382
1383 if (where->inlined_to)
1384 where = where->inlined_to;
1385
1386 reset_node_cache (where);
1387
1388 if (edge_growth_cache != NULL)
1389 for (edge = where->callers; edge; edge = edge->next_caller)
1390 if (edge->inline_failed)
1391 edge_growth_cache->remove (edge);
1392
1393 FOR_EACH_ALIAS (where, ref)
1394 reset_edge_caches (dyn_cast <cgraph_node *> (ref->referring));
1395
1396 if (!e)
1397 return;
1398
1399 while (true)
1400 if (!e->inline_failed && e->callee->callees)
1401 e = e->callee->callees;
1402 else
1403 {
1404 if (edge_growth_cache != NULL && e->inline_failed)
1405 edge_growth_cache->remove (e);
1406 if (e->next_callee)
1407 e = e->next_callee;
1408 else
1409 {
1410 do
1411 {
1412 if (e->caller == node)
1413 return;
1414 e = e->caller->callers;
1415 }
1416 while (!e->next_callee);
1417 e = e->next_callee;
1418 }
1419 }
1420 }
1421
1422 /* Recompute HEAP nodes for each of caller of NODE.
1423 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1424 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1425 it is inlinable. Otherwise check all edges. */
1426
1427 static void
1428 update_caller_keys (edge_heap_t *heap, struct cgraph_node *node,
1429 bitmap updated_nodes,
1430 struct cgraph_edge *check_inlinablity_for)
1431 {
1432 struct cgraph_edge *edge;
1433 struct ipa_ref *ref;
1434
1435 if ((!node->alias && !ipa_fn_summaries->get (node)->inlinable)
1436 || node->inlined_to)
1437 return;
1438 if (!bitmap_set_bit (updated_nodes, node->get_uid ()))
1439 return;
1440
1441 FOR_EACH_ALIAS (node, ref)
1442 {
1443 struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
1444 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for);
1445 }
1446
1447 for (edge = node->callers; edge; edge = edge->next_caller)
1448 if (edge->inline_failed)
1449 {
1450 if (!check_inlinablity_for
1451 || check_inlinablity_for == edge)
1452 {
1453 if (can_inline_edge_p (edge, false)
1454 && want_inline_small_function_p (edge, false)
1455 && can_inline_edge_by_limits_p (edge, false))
1456 update_edge_key (heap, edge);
1457 else if (edge->aux)
1458 {
1459 report_inline_failed_reason (edge);
1460 heap->delete_node ((edge_heap_node_t *) edge->aux);
1461 edge->aux = NULL;
1462 }
1463 }
1464 else if (edge->aux)
1465 update_edge_key (heap, edge);
1466 }
1467 }
1468
1469 /* Recompute HEAP nodes for each uninlined call in NODE
1470 If UPDATE_SINCE is non-NULL check if edges called within that function
1471 are inlinable (typically UPDATE_SINCE is the inline clone we introduced
1472 where all edges have new context).
1473
1474 This is used when we know that edge badnesses are going only to increase
1475 (we introduced new call site) and thus all we need is to insert newly
1476 created edges into heap. */
1477
1478 static void
1479 update_callee_keys (edge_heap_t *heap, struct cgraph_node *node,
1480 struct cgraph_node *update_since,
1481 bitmap updated_nodes)
1482 {
1483 struct cgraph_edge *e = node->callees;
1484 bool check_inlinability = update_since == node;
1485
1486 if (!e)
1487 return;
1488 while (true)
1489 if (!e->inline_failed && e->callee->callees)
1490 {
1491 if (e->callee == update_since)
1492 check_inlinability = true;
1493 e = e->callee->callees;
1494 }
1495 else
1496 {
1497 enum availability avail;
1498 struct cgraph_node *callee;
1499 if (!check_inlinability)
1500 {
1501 if (e->aux
1502 && !bitmap_bit_p (updated_nodes,
1503 e->callee->ultimate_alias_target
1504 (&avail, e->caller)->get_uid ()))
1505 update_edge_key (heap, e);
1506 }
1507 /* We do not reset callee growth cache here. Since we added a new call,
1508 growth should have just increased and consequently badness metric
1509 don't need updating. */
1510 else if (e->inline_failed
1511 && (callee = e->callee->ultimate_alias_target (&avail,
1512 e->caller))
1513 && avail >= AVAIL_AVAILABLE
1514 && ipa_fn_summaries->get (callee) != NULL
1515 && ipa_fn_summaries->get (callee)->inlinable
1516 && !bitmap_bit_p (updated_nodes, callee->get_uid ()))
1517 {
1518 if (can_inline_edge_p (e, false)
1519 && want_inline_small_function_p (e, false)
1520 && can_inline_edge_by_limits_p (e, false))
1521 {
1522 gcc_checking_assert (check_inlinability || can_inline_edge_p (e, false));
1523 gcc_checking_assert (check_inlinability || e->aux);
1524 update_edge_key (heap, e);
1525 }
1526 else if (e->aux)
1527 {
1528 report_inline_failed_reason (e);
1529 heap->delete_node ((edge_heap_node_t *) e->aux);
1530 e->aux = NULL;
1531 }
1532 }
1533 /* In case we redirected to unreachable node we only need to remove the
1534 fibheap entry. */
1535 else if (e->aux)
1536 {
1537 heap->delete_node ((edge_heap_node_t *) e->aux);
1538 e->aux = NULL;
1539 }
1540 if (e->next_callee)
1541 e = e->next_callee;
1542 else
1543 {
1544 do
1545 {
1546 if (e->caller == node)
1547 return;
1548 if (e->caller == update_since)
1549 check_inlinability = false;
1550 e = e->caller->callers;
1551 }
1552 while (!e->next_callee);
1553 e = e->next_callee;
1554 }
1555 }
1556 }
1557
1558 /* Enqueue all recursive calls from NODE into priority queue depending on
1559 how likely we want to recursively inline the call. */
1560
1561 static void
1562 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
1563 edge_heap_t *heap)
1564 {
1565 struct cgraph_edge *e;
1566 enum availability avail;
1567
1568 for (e = where->callees; e; e = e->next_callee)
1569 if (e->callee == node
1570 || (e->callee->ultimate_alias_target (&avail, e->caller) == node
1571 && avail > AVAIL_INTERPOSABLE))
1572 heap->insert (-e->sreal_frequency (), e);
1573 for (e = where->callees; e; e = e->next_callee)
1574 if (!e->inline_failed)
1575 lookup_recursive_calls (node, e->callee, heap);
1576 }
1577
1578 /* Decide on recursive inlining: in the case function has recursive calls,
1579 inline until body size reaches given argument. If any new indirect edges
1580 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1581 is NULL. */
1582
1583 static bool
1584 recursive_inlining (struct cgraph_edge *edge,
1585 vec<cgraph_edge *> *new_edges)
1586 {
1587 cgraph_node *to = (edge->caller->inlined_to
1588 ? edge->caller->inlined_to : edge->caller);
1589 int limit = opt_for_fn (to->decl,
1590 param_max_inline_insns_recursive_auto);
1591 edge_heap_t heap (sreal::min ());
1592 struct cgraph_node *node;
1593 struct cgraph_edge *e;
1594 struct cgraph_node *master_clone = NULL, *next;
1595 int depth = 0;
1596 int n = 0;
1597
1598 node = edge->caller;
1599 if (node->inlined_to)
1600 node = node->inlined_to;
1601
1602 if (DECL_DECLARED_INLINE_P (node->decl))
1603 limit = opt_for_fn (to->decl, param_max_inline_insns_recursive);
1604
1605 /* Make sure that function is small enough to be considered for inlining. */
1606 if (estimate_size_after_inlining (node, edge) >= limit)
1607 return false;
1608 lookup_recursive_calls (node, node, &heap);
1609 if (heap.empty ())
1610 return false;
1611
1612 if (dump_file)
1613 fprintf (dump_file,
1614 " Performing recursive inlining on %s\n", node->dump_name ());
1615
1616 /* Do the inlining and update list of recursive call during process. */
1617 while (!heap.empty ())
1618 {
1619 struct cgraph_edge *curr = heap.extract_min ();
1620 struct cgraph_node *cnode, *dest = curr->callee;
1621
1622 if (!can_inline_edge_p (curr, true)
1623 || !can_inline_edge_by_limits_p (curr, true))
1624 continue;
1625
1626 /* MASTER_CLONE is produced in the case we already started modified
1627 the function. Be sure to redirect edge to the original body before
1628 estimating growths otherwise we will be seeing growths after inlining
1629 the already modified body. */
1630 if (master_clone)
1631 {
1632 curr->redirect_callee (master_clone);
1633 if (edge_growth_cache != NULL)
1634 edge_growth_cache->remove (curr);
1635 }
1636
1637 if (estimate_size_after_inlining (node, curr) > limit)
1638 {
1639 curr->redirect_callee (dest);
1640 if (edge_growth_cache != NULL)
1641 edge_growth_cache->remove (curr);
1642 break;
1643 }
1644
1645 depth = 1;
1646 for (cnode = curr->caller;
1647 cnode->inlined_to; cnode = cnode->callers->caller)
1648 if (node->decl
1649 == curr->callee->ultimate_alias_target ()->decl)
1650 depth++;
1651
1652 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1653 {
1654 curr->redirect_callee (dest);
1655 if (edge_growth_cache != NULL)
1656 edge_growth_cache->remove (curr);
1657 continue;
1658 }
1659
1660 if (dump_file)
1661 {
1662 fprintf (dump_file,
1663 " Inlining call of depth %i", depth);
1664 if (node->count.nonzero_p () && curr->count.initialized_p ())
1665 {
1666 fprintf (dump_file, " called approx. %.2f times per call",
1667 (double)curr->count.to_gcov_type ()
1668 / node->count.to_gcov_type ());
1669 }
1670 fprintf (dump_file, "\n");
1671 }
1672 if (!master_clone)
1673 {
1674 /* We need original clone to copy around. */
1675 master_clone = node->create_clone (node->decl, node->count,
1676 false, vNULL, true, NULL, NULL);
1677 for (e = master_clone->callees; e; e = e->next_callee)
1678 if (!e->inline_failed)
1679 clone_inlined_nodes (e, true, false, NULL);
1680 curr->redirect_callee (master_clone);
1681 if (edge_growth_cache != NULL)
1682 edge_growth_cache->remove (curr);
1683 }
1684
1685 inline_call (curr, false, new_edges, &overall_size, true);
1686 reset_node_cache (node);
1687 lookup_recursive_calls (node, curr->callee, &heap);
1688 n++;
1689 }
1690
1691 if (!heap.empty () && dump_file)
1692 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1693
1694 if (!master_clone)
1695 return false;
1696
1697 if (dump_enabled_p ())
1698 dump_printf_loc (MSG_NOTE, edge->call_stmt,
1699 "\n Inlined %i times, "
1700 "body grown from size %i to %i, time %f to %f\n", n,
1701 ipa_size_summaries->get (master_clone)->size,
1702 ipa_size_summaries->get (node)->size,
1703 ipa_fn_summaries->get (master_clone)->time.to_double (),
1704 ipa_fn_summaries->get (node)->time.to_double ());
1705
1706 /* Remove master clone we used for inlining. We rely that clones inlined
1707 into master clone gets queued just before master clone so we don't
1708 need recursion. */
1709 for (node = symtab->first_function (); node != master_clone;
1710 node = next)
1711 {
1712 next = symtab->next_function (node);
1713 if (node->inlined_to == master_clone)
1714 node->remove ();
1715 }
1716 master_clone->remove ();
1717 return true;
1718 }
1719
1720
1721 /* Given whole compilation unit estimate of INSNS, compute how large we can
1722 allow the unit to grow. */
1723
1724 static int64_t
1725 compute_max_insns (cgraph_node *node, int insns)
1726 {
1727 int max_insns = insns;
1728 if (max_insns < opt_for_fn (node->decl, param_large_unit_insns))
1729 max_insns = opt_for_fn (node->decl, param_large_unit_insns);
1730
1731 return ((int64_t) max_insns
1732 * (100 + opt_for_fn (node->decl, param_inline_unit_growth)) / 100);
1733 }
1734
1735
1736 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1737
1738 static void
1739 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> new_edges)
1740 {
1741 while (new_edges.length () > 0)
1742 {
1743 struct cgraph_edge *edge = new_edges.pop ();
1744
1745 gcc_assert (!edge->aux);
1746 gcc_assert (edge->callee);
1747 if (edge->inline_failed
1748 && can_inline_edge_p (edge, true)
1749 && want_inline_small_function_p (edge, true)
1750 && can_inline_edge_by_limits_p (edge, true))
1751 edge->aux = heap->insert (edge_badness (edge, false), edge);
1752 }
1753 }
1754
1755 /* Remove EDGE from the fibheap. */
1756
1757 static void
1758 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1759 {
1760 if (e->aux)
1761 {
1762 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux);
1763 e->aux = NULL;
1764 }
1765 }
1766
1767 /* Return true if speculation of edge E seems useful.
1768 If ANTICIPATE_INLINING is true, be conservative and hope that E
1769 may get inlined. */
1770
1771 bool
1772 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1773 {
1774 /* If we have already decided to inline the edge, it seems useful. */
1775 if (!e->inline_failed)
1776 return true;
1777
1778 enum availability avail;
1779 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail,
1780 e->caller);
1781 struct cgraph_edge *direct, *indirect;
1782 struct ipa_ref *ref;
1783
1784 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1785
1786 if (!e->maybe_hot_p ())
1787 return false;
1788
1789 /* See if IP optimizations found something potentially useful about the
1790 function. For now we look only for CONST/PURE flags. Almost everything
1791 else we propagate is useless. */
1792 if (avail >= AVAIL_AVAILABLE)
1793 {
1794 int ecf_flags = flags_from_decl_or_type (target->decl);
1795 if (ecf_flags & ECF_CONST)
1796 {
1797 e->speculative_call_info (direct, indirect, ref);
1798 if (!(indirect->indirect_info->ecf_flags & ECF_CONST))
1799 return true;
1800 }
1801 else if (ecf_flags & ECF_PURE)
1802 {
1803 e->speculative_call_info (direct, indirect, ref);
1804 if (!(indirect->indirect_info->ecf_flags & ECF_PURE))
1805 return true;
1806 }
1807 }
1808 /* If we did not managed to inline the function nor redirect
1809 to an ipa-cp clone (that are seen by having local flag set),
1810 it is probably pointless to inline it unless hardware is missing
1811 indirect call predictor. */
1812 if (!anticipate_inlining && !target->local)
1813 return false;
1814 /* For overwritable targets there is not much to do. */
1815 if (!can_inline_edge_p (e, false)
1816 || !can_inline_edge_by_limits_p (e, false, true))
1817 return false;
1818 /* OK, speculation seems interesting. */
1819 return true;
1820 }
1821
1822 /* We know that EDGE is not going to be inlined.
1823 See if we can remove speculation. */
1824
1825 static void
1826 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge)
1827 {
1828 if (edge->speculative && !speculation_useful_p (edge, false))
1829 {
1830 struct cgraph_node *node = edge->caller;
1831 struct cgraph_node *where = node->inlined_to
1832 ? node->inlined_to : node;
1833 auto_bitmap updated_nodes;
1834
1835 if (edge->count.ipa ().initialized_p ())
1836 spec_rem += edge->count.ipa ();
1837 cgraph_edge::resolve_speculation (edge);
1838 reset_edge_caches (where);
1839 ipa_update_overall_fn_summary (where);
1840 update_caller_keys (edge_heap, where,
1841 updated_nodes, NULL);
1842 update_callee_keys (edge_heap, where, NULL,
1843 updated_nodes);
1844 }
1845 }
1846
1847 /* Return true if NODE should be accounted for overall size estimate.
1848 Skip all nodes optimized for size so we can measure the growth of hot
1849 part of program no matter of the padding. */
1850
1851 bool
1852 inline_account_function_p (struct cgraph_node *node)
1853 {
1854 return (!DECL_EXTERNAL (node->decl)
1855 && !opt_for_fn (node->decl, optimize_size)
1856 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
1857 }
1858
1859 /* Count number of callers of NODE and store it into DATA (that
1860 points to int. Worker for cgraph_for_node_and_aliases. */
1861
1862 static bool
1863 sum_callers (struct cgraph_node *node, void *data)
1864 {
1865 struct cgraph_edge *e;
1866 int *num_calls = (int *)data;
1867
1868 for (e = node->callers; e; e = e->next_caller)
1869 (*num_calls)++;
1870 return false;
1871 }
1872
1873 /* We only propagate across edges with non-interposable callee. */
1874
1875 inline bool
1876 ignore_edge_p (struct cgraph_edge *e)
1877 {
1878 enum availability avail;
1879 e->callee->function_or_virtual_thunk_symbol (&avail, e->caller);
1880 return (avail <= AVAIL_INTERPOSABLE);
1881 }
1882
1883 /* We use greedy algorithm for inlining of small functions:
1884 All inline candidates are put into prioritized heap ordered in
1885 increasing badness.
1886
1887 The inlining of small functions is bounded by unit growth parameters. */
1888
1889 static void
1890 inline_small_functions (void)
1891 {
1892 struct cgraph_node *node;
1893 struct cgraph_edge *edge;
1894 edge_heap_t edge_heap (sreal::min ());
1895 auto_bitmap updated_nodes;
1896 int min_size;
1897 auto_vec<cgraph_edge *> new_indirect_edges;
1898 int initial_size = 0;
1899 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count);
1900 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1901 new_indirect_edges.create (8);
1902
1903 edge_removal_hook_holder
1904 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap);
1905
1906 /* Compute overall unit size and other global parameters used by badness
1907 metrics. */
1908
1909 max_count = profile_count::uninitialized ();
1910 ipa_reduced_postorder (order, true, ignore_edge_p);
1911 free (order);
1912
1913 FOR_EACH_DEFINED_FUNCTION (node)
1914 if (!node->inlined_to)
1915 {
1916 if (!node->alias && node->analyzed
1917 && (node->has_gimple_body_p () || node->thunk.thunk_p)
1918 && opt_for_fn (node->decl, optimize))
1919 {
1920 class ipa_fn_summary *info = ipa_fn_summaries->get (node);
1921 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux;
1922
1923 /* Do not account external functions, they will be optimized out
1924 if not inlined. Also only count the non-cold portion of program. */
1925 if (inline_account_function_p (node))
1926 initial_size += ipa_size_summaries->get (node)->size;
1927 info->growth = estimate_growth (node);
1928
1929 int num_calls = 0;
1930 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
1931 true);
1932 if (num_calls == 1)
1933 info->single_caller = true;
1934 if (dfs && dfs->next_cycle)
1935 {
1936 struct cgraph_node *n2;
1937 int id = dfs->scc_no + 1;
1938 for (n2 = node; n2;
1939 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle)
1940 if (opt_for_fn (n2->decl, optimize))
1941 {
1942 ipa_fn_summary *info2 = ipa_fn_summaries->get
1943 (n2->inlined_to ? n2->inlined_to : n2);
1944 if (info2->scc_no)
1945 break;
1946 info2->scc_no = id;
1947 }
1948 }
1949 }
1950
1951 for (edge = node->callers; edge; edge = edge->next_caller)
1952 max_count = max_count.max (edge->count.ipa ());
1953 }
1954 ipa_free_postorder_info ();
1955 initialize_growth_caches ();
1956
1957 if (dump_file)
1958 fprintf (dump_file,
1959 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1960 initial_size);
1961
1962 overall_size = initial_size;
1963 min_size = overall_size;
1964
1965 /* Populate the heap with all edges we might inline. */
1966
1967 FOR_EACH_DEFINED_FUNCTION (node)
1968 {
1969 bool update = false;
1970 struct cgraph_edge *next = NULL;
1971 bool has_speculative = false;
1972
1973 if (!opt_for_fn (node->decl, optimize))
1974 continue;
1975
1976 if (dump_file)
1977 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ());
1978
1979 for (edge = node->callees; edge; edge = edge->next_callee)
1980 {
1981 if (edge->inline_failed
1982 && !edge->aux
1983 && can_inline_edge_p (edge, true)
1984 && want_inline_small_function_p (edge, true)
1985 && can_inline_edge_by_limits_p (edge, true)
1986 && edge->inline_failed)
1987 {
1988 gcc_assert (!edge->aux);
1989 update_edge_key (&edge_heap, edge);
1990 }
1991 if (edge->speculative)
1992 has_speculative = true;
1993 }
1994 if (has_speculative)
1995 for (edge = node->callees; edge; edge = next)
1996 {
1997 next = edge->next_callee;
1998 if (edge->speculative
1999 && !speculation_useful_p (edge, edge->aux != NULL))
2000 {
2001 cgraph_edge::resolve_speculation (edge);
2002 update = true;
2003 }
2004 }
2005 if (update)
2006 {
2007 struct cgraph_node *where = node->inlined_to
2008 ? node->inlined_to : node;
2009 ipa_update_overall_fn_summary (where);
2010 reset_edge_caches (where);
2011 update_caller_keys (&edge_heap, where,
2012 updated_nodes, NULL);
2013 update_callee_keys (&edge_heap, where, NULL,
2014 updated_nodes);
2015 bitmap_clear (updated_nodes);
2016 }
2017 }
2018
2019 gcc_assert (in_lto_p
2020 || !(max_count > 0)
2021 || (profile_info && flag_branch_probabilities));
2022
2023 while (!edge_heap.empty ())
2024 {
2025 int old_size = overall_size;
2026 struct cgraph_node *where, *callee;
2027 sreal badness = edge_heap.min_key ();
2028 sreal current_badness;
2029 int growth;
2030
2031 edge = edge_heap.extract_min ();
2032 gcc_assert (edge->aux);
2033 edge->aux = NULL;
2034 if (!edge->inline_failed || !edge->callee->analyzed)
2035 continue;
2036
2037 /* Be sure that caches are maintained consistent.
2038 This check is affected by scaling roundoff errors when compiling for
2039 IPA this we skip it in that case. */
2040 if (flag_checking && !edge->callee->count.ipa_p ()
2041 && (!max_count.initialized_p () || !max_count.nonzero_p ()))
2042 {
2043 sreal cached_badness = edge_badness (edge, false);
2044
2045 int old_size_est = estimate_edge_size (edge);
2046 sreal old_time_est = estimate_edge_time (edge);
2047 int old_hints_est = estimate_edge_hints (edge);
2048
2049 if (edge_growth_cache != NULL)
2050 edge_growth_cache->remove (edge);
2051 reset_node_cache (edge->caller->inlined_to
2052 ? edge->caller->inlined_to
2053 : edge->caller);
2054 gcc_assert (old_size_est == estimate_edge_size (edge));
2055 gcc_assert (old_time_est == estimate_edge_time (edge));
2056 /* FIXME:
2057
2058 gcc_assert (old_hints_est == estimate_edge_hints (edge));
2059
2060 fails with profile feedback because some hints depends on
2061 maybe_hot_edge_p predicate and because callee gets inlined to other
2062 calls, the edge may become cold.
2063 This ought to be fixed by computing relative probabilities
2064 for given invocation but that will be better done once whole
2065 code is converted to sreals. Disable for now and revert to "wrong"
2066 value so enable/disable checking paths agree. */
2067 edge_growth_cache->get (edge)->hints = old_hints_est + 1;
2068
2069 /* When updating the edge costs, we only decrease badness in the keys.
2070 Increases of badness are handled lazily; when we see key with out
2071 of date value on it, we re-insert it now. */
2072 current_badness = edge_badness (edge, false);
2073 gcc_assert (cached_badness == current_badness);
2074 gcc_assert (current_badness >= badness);
2075 }
2076 else
2077 current_badness = edge_badness (edge, false);
2078 if (current_badness != badness)
2079 {
2080 if (edge_heap.min () && current_badness > edge_heap.min_key ())
2081 {
2082 edge->aux = edge_heap.insert (current_badness, edge);
2083 continue;
2084 }
2085 else
2086 badness = current_badness;
2087 }
2088
2089 if (!can_inline_edge_p (edge, true)
2090 || !can_inline_edge_by_limits_p (edge, true))
2091 {
2092 resolve_noninline_speculation (&edge_heap, edge);
2093 continue;
2094 }
2095
2096 callee = edge->callee->ultimate_alias_target ();
2097 growth = estimate_edge_growth (edge);
2098 if (dump_file)
2099 {
2100 fprintf (dump_file,
2101 "\nConsidering %s with %i size\n",
2102 callee->dump_name (),
2103 ipa_size_summaries->get (callee)->size);
2104 fprintf (dump_file,
2105 " to be inlined into %s in %s:%i\n"
2106 " Estimated badness is %f, frequency %.2f.\n",
2107 edge->caller->dump_name (),
2108 edge->call_stmt
2109 && (LOCATION_LOCUS (gimple_location ((const gimple *)
2110 edge->call_stmt))
2111 > BUILTINS_LOCATION)
2112 ? gimple_filename ((const gimple *) edge->call_stmt)
2113 : "unknown",
2114 edge->call_stmt
2115 ? gimple_lineno ((const gimple *) edge->call_stmt)
2116 : -1,
2117 badness.to_double (),
2118 edge->sreal_frequency ().to_double ());
2119 if (edge->count.ipa ().initialized_p ())
2120 {
2121 fprintf (dump_file, " Called ");
2122 edge->count.ipa ().dump (dump_file);
2123 fprintf (dump_file, " times\n");
2124 }
2125 if (dump_flags & TDF_DETAILS)
2126 edge_badness (edge, true);
2127 }
2128
2129 where = edge->caller;
2130
2131 if (overall_size + growth > compute_max_insns (where, min_size)
2132 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2133 {
2134 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
2135 report_inline_failed_reason (edge);
2136 resolve_noninline_speculation (&edge_heap, edge);
2137 continue;
2138 }
2139
2140 if (!want_inline_small_function_p (edge, true))
2141 {
2142 resolve_noninline_speculation (&edge_heap, edge);
2143 continue;
2144 }
2145
2146 profile_count old_count = callee->count;
2147
2148 /* Heuristics for inlining small functions work poorly for
2149 recursive calls where we do effects similar to loop unrolling.
2150 When inlining such edge seems profitable, leave decision on
2151 specific inliner. */
2152 if (edge->recursive_p ())
2153 {
2154 if (where->inlined_to)
2155 where = where->inlined_to;
2156 if (!recursive_inlining (edge,
2157 opt_for_fn (edge->caller->decl,
2158 flag_indirect_inlining)
2159 ? &new_indirect_edges : NULL))
2160 {
2161 edge->inline_failed = CIF_RECURSIVE_INLINING;
2162 resolve_noninline_speculation (&edge_heap, edge);
2163 continue;
2164 }
2165 reset_edge_caches (where);
2166 /* Recursive inliner inlines all recursive calls of the function
2167 at once. Consequently we need to update all callee keys. */
2168 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining))
2169 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2170 update_callee_keys (&edge_heap, where, where, updated_nodes);
2171 bitmap_clear (updated_nodes);
2172 }
2173 else
2174 {
2175 struct cgraph_node *outer_node = NULL;
2176 int depth = 0;
2177
2178 /* Consider the case where self recursive function A is inlined
2179 into B. This is desired optimization in some cases, since it
2180 leads to effect similar of loop peeling and we might completely
2181 optimize out the recursive call. However we must be extra
2182 selective. */
2183
2184 where = edge->caller;
2185 while (where->inlined_to)
2186 {
2187 if (where->decl == callee->decl)
2188 outer_node = where, depth++;
2189 where = where->callers->caller;
2190 }
2191 if (outer_node
2192 && !want_inline_self_recursive_call_p (edge, outer_node,
2193 true, depth))
2194 {
2195 edge->inline_failed
2196 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl)
2197 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
2198 resolve_noninline_speculation (&edge_heap, edge);
2199 continue;
2200 }
2201 else if (depth && dump_file)
2202 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
2203
2204 gcc_checking_assert (!callee->inlined_to);
2205
2206 int old_size = ipa_size_summaries->get (where)->size;
2207 sreal old_time = ipa_fn_summaries->get (where)->time;
2208
2209 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
2210 reset_edge_caches (edge->callee);
2211 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2212
2213 /* If caller's size and time increased we do not need to update
2214 all edges because badness is not going to decrease. */
2215 if (old_size <= ipa_size_summaries->get (where)->size
2216 && old_time <= ipa_fn_summaries->get (where)->time
2217 /* Wrapper penalty may be non-monotonous in this respect.
2218 Fortunately it only affects small functions. */
2219 && !wrapper_heuristics_may_apply (where, old_size))
2220 update_callee_keys (&edge_heap, edge->callee, edge->callee,
2221 updated_nodes);
2222 else
2223 update_callee_keys (&edge_heap, where,
2224 edge->callee,
2225 updated_nodes);
2226 }
2227 where = edge->caller;
2228 if (where->inlined_to)
2229 where = where->inlined_to;
2230
2231 /* Our profitability metric can depend on local properties
2232 such as number of inlinable calls and size of the function body.
2233 After inlining these properties might change for the function we
2234 inlined into (since it's body size changed) and for the functions
2235 called by function we inlined (since number of it inlinable callers
2236 might change). */
2237 update_caller_keys (&edge_heap, where, updated_nodes, NULL);
2238 /* Offline copy count has possibly changed, recompute if profile is
2239 available. */
2240 struct cgraph_node *n
2241 = cgraph_node::get (edge->callee->decl)->ultimate_alias_target ();
2242 if (n != edge->callee && n->analyzed && !(n->count == old_count)
2243 && n->count.ipa_p ())
2244 update_callee_keys (&edge_heap, n, NULL, updated_nodes);
2245 bitmap_clear (updated_nodes);
2246
2247 if (dump_enabled_p ())
2248 {
2249 ipa_fn_summary *s = ipa_fn_summaries->get (where);
2250
2251 /* dump_printf can't handle %+i. */
2252 char buf_net_change[100];
2253 snprintf (buf_net_change, sizeof buf_net_change, "%+i",
2254 overall_size - old_size);
2255
2256 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt,
2257 " Inlined %C into %C which now has time %f and "
2258 "size %i, net change of %s%s.\n",
2259 edge->callee, edge->caller,
2260 s->time.to_double (),
2261 ipa_size_summaries->get (edge->caller)->size,
2262 buf_net_change,
2263 cross_module_call_p (edge) ? " (cross module)":"");
2264 }
2265 if (min_size > overall_size)
2266 {
2267 min_size = overall_size;
2268
2269 if (dump_file)
2270 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
2271 }
2272 }
2273
2274 free_growth_caches ();
2275 if (dump_enabled_p ())
2276 dump_printf (MSG_NOTE,
2277 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2278 initial_size, overall_size,
2279 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
2280 symtab->remove_edge_removal_hook (edge_removal_hook_holder);
2281 }
2282
2283 /* Flatten NODE. Performed both during early inlining and
2284 at IPA inlining time. */
2285
2286 static void
2287 flatten_function (struct cgraph_node *node, bool early, bool update)
2288 {
2289 struct cgraph_edge *e;
2290
2291 /* We shouldn't be called recursively when we are being processed. */
2292 gcc_assert (node->aux == NULL);
2293
2294 node->aux = (void *) node;
2295
2296 for (e = node->callees; e; e = e->next_callee)
2297 {
2298 struct cgraph_node *orig_callee;
2299 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2300
2301 /* We've hit cycle? It is time to give up. */
2302 if (callee->aux)
2303 {
2304 if (dump_enabled_p ())
2305 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2306 "Not inlining %C into %C to avoid cycle.\n",
2307 callee, e->caller);
2308 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR)
2309 e->inline_failed = CIF_RECURSIVE_INLINING;
2310 continue;
2311 }
2312
2313 /* When the edge is already inlined, we just need to recurse into
2314 it in order to fully flatten the leaves. */
2315 if (!e->inline_failed)
2316 {
2317 flatten_function (callee, early, false);
2318 continue;
2319 }
2320
2321 /* Flatten attribute needs to be processed during late inlining. For
2322 extra code quality we however do flattening during early optimization,
2323 too. */
2324 if (!early
2325 ? !can_inline_edge_p (e, true)
2326 && !can_inline_edge_by_limits_p (e, true)
2327 : !can_early_inline_edge_p (e))
2328 continue;
2329
2330 if (e->recursive_p ())
2331 {
2332 if (dump_enabled_p ())
2333 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2334 "Not inlining: recursive call.\n");
2335 continue;
2336 }
2337
2338 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
2339 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
2340 {
2341 if (dump_enabled_p ())
2342 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2343 "Not inlining: SSA form does not match.\n");
2344 continue;
2345 }
2346
2347 /* Inline the edge and flatten the inline clone. Avoid
2348 recursing through the original node if the node was cloned. */
2349 if (dump_enabled_p ())
2350 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2351 " Inlining %C into %C.\n",
2352 callee, e->caller);
2353 orig_callee = callee;
2354 inline_call (e, true, NULL, NULL, false);
2355 if (e->callee != orig_callee)
2356 orig_callee->aux = (void *) node;
2357 flatten_function (e->callee, early, false);
2358 if (e->callee != orig_callee)
2359 orig_callee->aux = NULL;
2360 }
2361
2362 node->aux = NULL;
2363 cgraph_node *where = node->inlined_to ? node->inlined_to : node;
2364 if (update && opt_for_fn (where->decl, optimize))
2365 ipa_update_overall_fn_summary (where);
2366 }
2367
2368 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2369 DATA points to number of calls originally found so we avoid infinite
2370 recursion. */
2371
2372 static bool
2373 inline_to_all_callers_1 (struct cgraph_node *node, void *data,
2374 hash_set<cgraph_node *> *callers)
2375 {
2376 int *num_calls = (int *)data;
2377 bool callee_removed = false;
2378
2379 while (node->callers && !node->inlined_to)
2380 {
2381 struct cgraph_node *caller = node->callers->caller;
2382
2383 if (!can_inline_edge_p (node->callers, true)
2384 || !can_inline_edge_by_limits_p (node->callers, true)
2385 || node->callers->recursive_p ())
2386 {
2387 if (dump_file)
2388 fprintf (dump_file, "Uninlinable call found; giving up.\n");
2389 *num_calls = 0;
2390 return false;
2391 }
2392
2393 if (dump_file)
2394 {
2395 cgraph_node *ultimate = node->ultimate_alias_target ();
2396 fprintf (dump_file,
2397 "\nInlining %s size %i.\n",
2398 ultimate->dump_name (),
2399 ipa_size_summaries->get (ultimate)->size);
2400 fprintf (dump_file,
2401 " Called once from %s %i insns.\n",
2402 node->callers->caller->dump_name (),
2403 ipa_size_summaries->get (node->callers->caller)->size);
2404 }
2405
2406 /* Remember which callers we inlined to, delaying updating the
2407 overall summary. */
2408 callers->add (node->callers->caller);
2409 inline_call (node->callers, true, NULL, NULL, false, &callee_removed);
2410 if (dump_file)
2411 fprintf (dump_file,
2412 " Inlined into %s which now has %i size\n",
2413 caller->dump_name (),
2414 ipa_size_summaries->get (caller)->size);
2415 if (!(*num_calls)--)
2416 {
2417 if (dump_file)
2418 fprintf (dump_file, "New calls found; giving up.\n");
2419 return callee_removed;
2420 }
2421 if (callee_removed)
2422 return true;
2423 }
2424 return false;
2425 }
2426
2427 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2428 update. */
2429
2430 static bool
2431 inline_to_all_callers (struct cgraph_node *node, void *data)
2432 {
2433 hash_set<cgraph_node *> callers;
2434 bool res = inline_to_all_callers_1 (node, data, &callers);
2435 /* Perform the delayed update of the overall summary of all callers
2436 processed. This avoids quadratic behavior in the cases where
2437 we have a lot of calls to the same function. */
2438 for (hash_set<cgraph_node *>::iterator i = callers.begin ();
2439 i != callers.end (); ++i)
2440 ipa_update_overall_fn_summary ((*i)->inlined_to ? (*i)->inlined_to : *i);
2441 return res;
2442 }
2443
2444 /* Output overall time estimate. */
2445 static void
2446 dump_overall_stats (void)
2447 {
2448 sreal sum_weighted = 0, sum = 0;
2449 struct cgraph_node *node;
2450
2451 FOR_EACH_DEFINED_FUNCTION (node)
2452 if (!node->inlined_to
2453 && !node->alias)
2454 {
2455 ipa_fn_summary *s = ipa_fn_summaries->get (node);
2456 if (s != NULL)
2457 {
2458 sum += s->time;
2459 if (node->count.ipa ().initialized_p ())
2460 sum_weighted += s->time * node->count.ipa ().to_gcov_type ();
2461 }
2462 }
2463 fprintf (dump_file, "Overall time estimate: "
2464 "%f weighted by profile: "
2465 "%f\n", sum.to_double (), sum_weighted.to_double ());
2466 }
2467
2468 /* Output some useful stats about inlining. */
2469
2470 static void
2471 dump_inline_stats (void)
2472 {
2473 int64_t inlined_cnt = 0, inlined_indir_cnt = 0;
2474 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0;
2475 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0;
2476 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0;
2477 int64_t inlined_speculative = 0, inlined_speculative_ply = 0;
2478 int64_t indirect_poly_cnt = 0, indirect_cnt = 0;
2479 int64_t reason[CIF_N_REASONS][2];
2480 sreal reason_freq[CIF_N_REASONS];
2481 int i;
2482 struct cgraph_node *node;
2483
2484 memset (reason, 0, sizeof (reason));
2485 for (i=0; i < CIF_N_REASONS; i++)
2486 reason_freq[i] = 0;
2487 FOR_EACH_DEFINED_FUNCTION (node)
2488 {
2489 struct cgraph_edge *e;
2490 for (e = node->callees; e; e = e->next_callee)
2491 {
2492 if (e->inline_failed)
2493 {
2494 if (e->count.ipa ().initialized_p ())
2495 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type ();
2496 reason_freq[(int) e->inline_failed] += e->sreal_frequency ();
2497 reason[(int) e->inline_failed][1] ++;
2498 if (DECL_VIRTUAL_P (e->callee->decl)
2499 && e->count.ipa ().initialized_p ())
2500 {
2501 if (e->indirect_inlining_edge)
2502 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2503 else
2504 noninlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2505 }
2506 else if (e->count.ipa ().initialized_p ())
2507 {
2508 if (e->indirect_inlining_edge)
2509 noninlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2510 else
2511 noninlined_cnt += e->count.ipa ().to_gcov_type ();
2512 }
2513 }
2514 else if (e->count.ipa ().initialized_p ())
2515 {
2516 if (e->speculative)
2517 {
2518 if (DECL_VIRTUAL_P (e->callee->decl))
2519 inlined_speculative_ply += e->count.ipa ().to_gcov_type ();
2520 else
2521 inlined_speculative += e->count.ipa ().to_gcov_type ();
2522 }
2523 else if (DECL_VIRTUAL_P (e->callee->decl))
2524 {
2525 if (e->indirect_inlining_edge)
2526 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2527 else
2528 inlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2529 }
2530 else
2531 {
2532 if (e->indirect_inlining_edge)
2533 inlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2534 else
2535 inlined_cnt += e->count.ipa ().to_gcov_type ();
2536 }
2537 }
2538 }
2539 for (e = node->indirect_calls; e; e = e->next_callee)
2540 if (e->indirect_info->polymorphic
2541 & e->count.ipa ().initialized_p ())
2542 indirect_poly_cnt += e->count.ipa ().to_gcov_type ();
2543 else if (e->count.ipa ().initialized_p ())
2544 indirect_cnt += e->count.ipa ().to_gcov_type ();
2545 }
2546 if (max_count.initialized_p ())
2547 {
2548 fprintf (dump_file,
2549 "Inlined %" PRId64 " + speculative "
2550 "%" PRId64 " + speculative polymorphic "
2551 "%" PRId64 " + previously indirect "
2552 "%" PRId64 " + virtual "
2553 "%" PRId64 " + virtual and previously indirect "
2554 "%" PRId64 "\n" "Not inlined "
2555 "%" PRId64 " + previously indirect "
2556 "%" PRId64 " + virtual "
2557 "%" PRId64 " + virtual and previously indirect "
2558 "%" PRId64 " + still indirect "
2559 "%" PRId64 " + still indirect polymorphic "
2560 "%" PRId64 "\n", inlined_cnt,
2561 inlined_speculative, inlined_speculative_ply,
2562 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt,
2563 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt,
2564 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt);
2565 fprintf (dump_file, "Removed speculations ");
2566 spec_rem.dump (dump_file);
2567 fprintf (dump_file, "\n");
2568 }
2569 dump_overall_stats ();
2570 fprintf (dump_file, "\nWhy inlining failed?\n");
2571 for (i = 0; i < CIF_N_REASONS; i++)
2572 if (reason[i][1])
2573 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n",
2574 cgraph_inline_failed_string ((cgraph_inline_failed_t) i),
2575 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]);
2576 }
2577
2578 /* Called when node is removed. */
2579
2580 static void
2581 flatten_remove_node_hook (struct cgraph_node *node, void *data)
2582 {
2583 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL)
2584 return;
2585
2586 hash_set<struct cgraph_node *> *removed
2587 = (hash_set<struct cgraph_node *> *) data;
2588 removed->add (node);
2589 }
2590
2591 /* Decide on the inlining. We do so in the topological order to avoid
2592 expenses on updating data structures. */
2593
2594 static unsigned int
2595 ipa_inline (void)
2596 {
2597 struct cgraph_node *node;
2598 int nnodes;
2599 struct cgraph_node **order;
2600 int i, j;
2601 int cold;
2602 bool remove_functions = false;
2603
2604 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
2605
2606 if (dump_file)
2607 ipa_dump_fn_summaries (dump_file);
2608
2609 nnodes = ipa_reverse_postorder (order);
2610 spec_rem = profile_count::zero ();
2611
2612 FOR_EACH_FUNCTION (node)
2613 {
2614 node->aux = 0;
2615
2616 /* Recompute the default reasons for inlining because they may have
2617 changed during merging. */
2618 if (in_lto_p)
2619 {
2620 for (cgraph_edge *e = node->callees; e; e = e->next_callee)
2621 {
2622 gcc_assert (e->inline_failed);
2623 initialize_inline_failed (e);
2624 }
2625 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
2626 initialize_inline_failed (e);
2627 }
2628 }
2629
2630 if (dump_file)
2631 fprintf (dump_file, "\nFlattening functions:\n");
2632
2633 /* First shrink order array, so that it only contains nodes with
2634 flatten attribute. */
2635 for (i = nnodes - 1, j = i; i >= 0; i--)
2636 {
2637 node = order[i];
2638 if (node->definition
2639 && lookup_attribute ("flatten",
2640 DECL_ATTRIBUTES (node->decl)) != NULL)
2641 order[j--] = order[i];
2642 }
2643
2644 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain
2645 nodes with flatten attribute. If there is more than one such
2646 node, we need to register a node removal hook, as flatten_function
2647 could remove other nodes with flatten attribute. See PR82801. */
2648 struct cgraph_node_hook_list *node_removal_hook_holder = NULL;
2649 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL;
2650 if (j < nnodes - 2)
2651 {
2652 flatten_removed_nodes = new hash_set<struct cgraph_node *>;
2653 node_removal_hook_holder
2654 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook,
2655 flatten_removed_nodes);
2656 }
2657
2658 /* In the first pass handle functions to be flattened. Do this with
2659 a priority so none of our later choices will make this impossible. */
2660 for (i = nnodes - 1; i > j; i--)
2661 {
2662 node = order[i];
2663 if (flatten_removed_nodes
2664 && flatten_removed_nodes->contains (node))
2665 continue;
2666
2667 /* Handle nodes to be flattened.
2668 Ideally when processing callees we stop inlining at the
2669 entry of cycles, possibly cloning that entry point and
2670 try to flatten itself turning it into a self-recursive
2671 function. */
2672 if (dump_file)
2673 fprintf (dump_file, "Flattening %s\n", node->dump_name ());
2674 flatten_function (node, false, true);
2675 }
2676
2677 if (j < nnodes - 2)
2678 {
2679 symtab->remove_cgraph_removal_hook (node_removal_hook_holder);
2680 delete flatten_removed_nodes;
2681 }
2682 free (order);
2683
2684 if (dump_file)
2685 dump_overall_stats ();
2686
2687 inline_small_functions ();
2688
2689 gcc_assert (symtab->state == IPA_SSA);
2690 symtab->state = IPA_SSA_AFTER_INLINING;
2691 /* Do first after-inlining removal. We want to remove all "stale" extern
2692 inline functions and virtual functions so we really know what is called
2693 once. */
2694 symtab->remove_unreachable_nodes (dump_file);
2695
2696 /* Inline functions with a property that after inlining into all callers the
2697 code size will shrink because the out-of-line copy is eliminated.
2698 We do this regardless on the callee size as long as function growth limits
2699 are met. */
2700 if (dump_file)
2701 fprintf (dump_file,
2702 "\nDeciding on functions to be inlined into all callers and "
2703 "removing useless speculations:\n");
2704
2705 /* Inlining one function called once has good chance of preventing
2706 inlining other function into the same callee. Ideally we should
2707 work in priority order, but probably inlining hot functions first
2708 is good cut without the extra pain of maintaining the queue.
2709
2710 ??? this is not really fitting the bill perfectly: inlining function
2711 into callee often leads to better optimization of callee due to
2712 increased context for optimization.
2713 For example if main() function calls a function that outputs help
2714 and then function that does the main optimization, we should inline
2715 the second with priority even if both calls are cold by themselves.
2716
2717 We probably want to implement new predicate replacing our use of
2718 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2719 to be hot. */
2720 for (cold = 0; cold <= 1; cold ++)
2721 {
2722 FOR_EACH_DEFINED_FUNCTION (node)
2723 {
2724 struct cgraph_edge *edge, *next;
2725 bool update=false;
2726
2727 if (!opt_for_fn (node->decl, optimize)
2728 || !opt_for_fn (node->decl, flag_inline_functions_called_once))
2729 continue;
2730
2731 for (edge = node->callees; edge; edge = next)
2732 {
2733 next = edge->next_callee;
2734 if (edge->speculative && !speculation_useful_p (edge, false))
2735 {
2736 if (edge->count.ipa ().initialized_p ())
2737 spec_rem += edge->count.ipa ();
2738 cgraph_edge::resolve_speculation (edge);
2739 update = true;
2740 remove_functions = true;
2741 }
2742 }
2743 if (update)
2744 {
2745 struct cgraph_node *where = node->inlined_to
2746 ? node->inlined_to : node;
2747 reset_edge_caches (where);
2748 ipa_update_overall_fn_summary (where);
2749 }
2750 if (want_inline_function_to_all_callers_p (node, cold))
2751 {
2752 int num_calls = 0;
2753 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
2754 true);
2755 while (node->call_for_symbol_and_aliases
2756 (inline_to_all_callers, &num_calls, true))
2757 ;
2758 remove_functions = true;
2759 }
2760 }
2761 }
2762
2763 /* Free ipa-prop structures if they are no longer needed. */
2764 ipa_free_all_structures_after_iinln ();
2765
2766 if (dump_enabled_p ())
2767 dump_printf (MSG_NOTE,
2768 "\nInlined %i calls, eliminated %i functions\n\n",
2769 ncalls_inlined, nfunctions_inlined);
2770 if (dump_file)
2771 dump_inline_stats ();
2772
2773 if (dump_file)
2774 ipa_dump_fn_summaries (dump_file);
2775 return remove_functions ? TODO_remove_functions : 0;
2776 }
2777
2778 /* Inline always-inline function calls in NODE. */
2779
2780 static bool
2781 inline_always_inline_functions (struct cgraph_node *node)
2782 {
2783 struct cgraph_edge *e;
2784 bool inlined = false;
2785
2786 for (e = node->callees; e; e = e->next_callee)
2787 {
2788 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2789 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2790 continue;
2791
2792 if (e->recursive_p ())
2793 {
2794 if (dump_enabled_p ())
2795 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2796 " Not inlining recursive call to %C.\n",
2797 e->callee);
2798 e->inline_failed = CIF_RECURSIVE_INLINING;
2799 continue;
2800 }
2801
2802 if (!can_early_inline_edge_p (e))
2803 {
2804 /* Set inlined to true if the callee is marked "always_inline" but
2805 is not inlinable. This will allow flagging an error later in
2806 expand_call_inline in tree-inline.c. */
2807 if (lookup_attribute ("always_inline",
2808 DECL_ATTRIBUTES (callee->decl)) != NULL)
2809 inlined = true;
2810 continue;
2811 }
2812
2813 if (dump_enabled_p ())
2814 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2815 " Inlining %C into %C (always_inline).\n",
2816 e->callee, e->caller);
2817 inline_call (e, true, NULL, NULL, false);
2818 inlined = true;
2819 }
2820 if (inlined)
2821 ipa_update_overall_fn_summary (node);
2822
2823 return inlined;
2824 }
2825
2826 /* Decide on the inlining. We do so in the topological order to avoid
2827 expenses on updating data structures. */
2828
2829 static bool
2830 early_inline_small_functions (struct cgraph_node *node)
2831 {
2832 struct cgraph_edge *e;
2833 bool inlined = false;
2834
2835 for (e = node->callees; e; e = e->next_callee)
2836 {
2837 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2838
2839 /* We can encounter not-yet-analyzed function during
2840 early inlining on callgraphs with strongly
2841 connected components. */
2842 ipa_fn_summary *s = ipa_fn_summaries->get (callee);
2843 if (s == NULL || !s->inlinable || !e->inline_failed)
2844 continue;
2845
2846 /* Do not consider functions not declared inline. */
2847 if (!DECL_DECLARED_INLINE_P (callee->decl)
2848 && !opt_for_fn (node->decl, flag_inline_small_functions)
2849 && !opt_for_fn (node->decl, flag_inline_functions))
2850 continue;
2851
2852 if (dump_enabled_p ())
2853 dump_printf_loc (MSG_NOTE, e->call_stmt,
2854 "Considering inline candidate %C.\n",
2855 callee);
2856
2857 if (!can_early_inline_edge_p (e))
2858 continue;
2859
2860 if (e->recursive_p ())
2861 {
2862 if (dump_enabled_p ())
2863 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2864 " Not inlining: recursive call.\n");
2865 continue;
2866 }
2867
2868 if (!want_early_inline_function_p (e))
2869 continue;
2870
2871 if (dump_enabled_p ())
2872 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2873 " Inlining %C into %C.\n",
2874 callee, e->caller);
2875 inline_call (e, true, NULL, NULL, false);
2876 inlined = true;
2877 }
2878
2879 if (inlined)
2880 ipa_update_overall_fn_summary (node);
2881
2882 return inlined;
2883 }
2884
2885 unsigned int
2886 early_inliner (function *fun)
2887 {
2888 struct cgraph_node *node = cgraph_node::get (current_function_decl);
2889 struct cgraph_edge *edge;
2890 unsigned int todo = 0;
2891 int iterations = 0;
2892 bool inlined = false;
2893
2894 if (seen_error ())
2895 return 0;
2896
2897 /* Do nothing if datastructures for ipa-inliner are already computed. This
2898 happens when some pass decides to construct new function and
2899 cgraph_add_new_function calls lowering passes and early optimization on
2900 it. This may confuse ourself when early inliner decide to inline call to
2901 function clone, because function clones don't have parameter list in
2902 ipa-prop matching their signature. */
2903 if (ipa_node_params_sum)
2904 return 0;
2905
2906 if (flag_checking)
2907 node->verify ();
2908 node->remove_all_references ();
2909
2910 /* Even when not optimizing or not inlining inline always-inline
2911 functions. */
2912 inlined = inline_always_inline_functions (node);
2913
2914 if (!optimize
2915 || flag_no_inline
2916 || !flag_early_inlining
2917 /* Never inline regular functions into always-inline functions
2918 during incremental inlining. This sucks as functions calling
2919 always inline functions will get less optimized, but at the
2920 same time inlining of functions calling always inline
2921 function into an always inline function might introduce
2922 cycles of edges to be always inlined in the callgraph.
2923
2924 We might want to be smarter and just avoid this type of inlining. */
2925 || (DECL_DISREGARD_INLINE_LIMITS (node->decl)
2926 && lookup_attribute ("always_inline",
2927 DECL_ATTRIBUTES (node->decl))))
2928 ;
2929 else if (lookup_attribute ("flatten",
2930 DECL_ATTRIBUTES (node->decl)) != NULL)
2931 {
2932 /* When the function is marked to be flattened, recursively inline
2933 all calls in it. */
2934 if (dump_enabled_p ())
2935 dump_printf (MSG_OPTIMIZED_LOCATIONS,
2936 "Flattening %C\n", node);
2937 flatten_function (node, true, true);
2938 inlined = true;
2939 }
2940 else
2941 {
2942 /* If some always_inline functions was inlined, apply the changes.
2943 This way we will not account always inline into growth limits and
2944 moreover we will inline calls from always inlines that we skipped
2945 previously because of conditional above. */
2946 if (inlined)
2947 {
2948 timevar_push (TV_INTEGRATION);
2949 todo |= optimize_inline_calls (current_function_decl);
2950 /* optimize_inline_calls call above might have introduced new
2951 statements that don't have inline parameters computed. */
2952 for (edge = node->callees; edge; edge = edge->next_callee)
2953 {
2954 /* We can enounter not-yet-analyzed function during
2955 early inlining on callgraphs with strongly
2956 connected components. */
2957 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2958 es->call_stmt_size
2959 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2960 es->call_stmt_time
2961 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2962 }
2963 ipa_update_overall_fn_summary (node);
2964 inlined = false;
2965 timevar_pop (TV_INTEGRATION);
2966 }
2967 /* We iterate incremental inlining to get trivial cases of indirect
2968 inlining. */
2969 while (iterations < opt_for_fn (node->decl,
2970 param_early_inliner_max_iterations)
2971 && early_inline_small_functions (node))
2972 {
2973 timevar_push (TV_INTEGRATION);
2974 todo |= optimize_inline_calls (current_function_decl);
2975
2976 /* Technically we ought to recompute inline parameters so the new
2977 iteration of early inliner works as expected. We however have
2978 values approximately right and thus we only need to update edge
2979 info that might be cleared out for newly discovered edges. */
2980 for (edge = node->callees; edge; edge = edge->next_callee)
2981 {
2982 /* We have no summary for new bound store calls yet. */
2983 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2984 es->call_stmt_size
2985 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2986 es->call_stmt_time
2987 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2988 }
2989 if (iterations < opt_for_fn (node->decl,
2990 param_early_inliner_max_iterations) - 1)
2991 ipa_update_overall_fn_summary (node);
2992 timevar_pop (TV_INTEGRATION);
2993 iterations++;
2994 inlined = false;
2995 }
2996 if (dump_file)
2997 fprintf (dump_file, "Iterations: %i\n", iterations);
2998 }
2999
3000 if (inlined)
3001 {
3002 timevar_push (TV_INTEGRATION);
3003 todo |= optimize_inline_calls (current_function_decl);
3004 timevar_pop (TV_INTEGRATION);
3005 }
3006
3007 fun->always_inline_functions_inlined = true;
3008
3009 return todo;
3010 }
3011
3012 /* Do inlining of small functions. Doing so early helps profiling and other
3013 passes to be somewhat more effective and avoids some code duplication in
3014 later real inlining pass for testcases with very many function calls. */
3015
3016 namespace {
3017
3018 const pass_data pass_data_early_inline =
3019 {
3020 GIMPLE_PASS, /* type */
3021 "einline", /* name */
3022 OPTGROUP_INLINE, /* optinfo_flags */
3023 TV_EARLY_INLINING, /* tv_id */
3024 PROP_ssa, /* properties_required */
3025 0, /* properties_provided */
3026 0, /* properties_destroyed */
3027 0, /* todo_flags_start */
3028 0, /* todo_flags_finish */
3029 };
3030
3031 class pass_early_inline : public gimple_opt_pass
3032 {
3033 public:
3034 pass_early_inline (gcc::context *ctxt)
3035 : gimple_opt_pass (pass_data_early_inline, ctxt)
3036 {}
3037
3038 /* opt_pass methods: */
3039 virtual unsigned int execute (function *);
3040
3041 }; // class pass_early_inline
3042
3043 unsigned int
3044 pass_early_inline::execute (function *fun)
3045 {
3046 return early_inliner (fun);
3047 }
3048
3049 } // anon namespace
3050
3051 gimple_opt_pass *
3052 make_pass_early_inline (gcc::context *ctxt)
3053 {
3054 return new pass_early_inline (ctxt);
3055 }
3056
3057 namespace {
3058
3059 const pass_data pass_data_ipa_inline =
3060 {
3061 IPA_PASS, /* type */
3062 "inline", /* name */
3063 OPTGROUP_INLINE, /* optinfo_flags */
3064 TV_IPA_INLINING, /* tv_id */
3065 0, /* properties_required */
3066 0, /* properties_provided */
3067 0, /* properties_destroyed */
3068 0, /* todo_flags_start */
3069 ( TODO_dump_symtab ), /* todo_flags_finish */
3070 };
3071
3072 class pass_ipa_inline : public ipa_opt_pass_d
3073 {
3074 public:
3075 pass_ipa_inline (gcc::context *ctxt)
3076 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt,
3077 NULL, /* generate_summary */
3078 NULL, /* write_summary */
3079 NULL, /* read_summary */
3080 NULL, /* write_optimization_summary */
3081 NULL, /* read_optimization_summary */
3082 NULL, /* stmt_fixup */
3083 0, /* function_transform_todo_flags_start */
3084 inline_transform, /* function_transform */
3085 NULL) /* variable_transform */
3086 {}
3087
3088 /* opt_pass methods: */
3089 virtual unsigned int execute (function *) { return ipa_inline (); }
3090
3091 }; // class pass_ipa_inline
3092
3093 } // anon namespace
3094
3095 ipa_opt_pass_d *
3096 make_pass_ipa_inline (gcc::context *ctxt)
3097 {
3098 return new pass_ipa_inline (ctxt);
3099 }