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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",
1615 node->name ());
1616
1617 /* Do the inlining and update list of recursive call during process. */
1618 while (!heap.empty ())
1619 {
1620 struct cgraph_edge *curr = heap.extract_min ();
1621 struct cgraph_node *cnode, *dest = curr->callee;
1622
1623 if (!can_inline_edge_p (curr, true)
1624 || !can_inline_edge_by_limits_p (curr, true))
1625 continue;
1626
1627 /* MASTER_CLONE is produced in the case we already started modified
1628 the function. Be sure to redirect edge to the original body before
1629 estimating growths otherwise we will be seeing growths after inlining
1630 the already modified body. */
1631 if (master_clone)
1632 {
1633 curr->redirect_callee (master_clone);
1634 if (edge_growth_cache != NULL)
1635 edge_growth_cache->remove (curr);
1636 }
1637
1638 if (estimate_size_after_inlining (node, curr) > limit)
1639 {
1640 curr->redirect_callee (dest);
1641 if (edge_growth_cache != NULL)
1642 edge_growth_cache->remove (curr);
1643 break;
1644 }
1645
1646 depth = 1;
1647 for (cnode = curr->caller;
1648 cnode->inlined_to; cnode = cnode->callers->caller)
1649 if (node->decl
1650 == curr->callee->ultimate_alias_target ()->decl)
1651 depth++;
1652
1653 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1654 {
1655 curr->redirect_callee (dest);
1656 if (edge_growth_cache != NULL)
1657 edge_growth_cache->remove (curr);
1658 continue;
1659 }
1660
1661 if (dump_file)
1662 {
1663 fprintf (dump_file,
1664 " Inlining call of depth %i", depth);
1665 if (node->count.nonzero_p () && curr->count.initialized_p ())
1666 {
1667 fprintf (dump_file, " called approx. %.2f times per call",
1668 (double)curr->count.to_gcov_type ()
1669 / node->count.to_gcov_type ());
1670 }
1671 fprintf (dump_file, "\n");
1672 }
1673 if (!master_clone)
1674 {
1675 /* We need original clone to copy around. */
1676 master_clone = node->create_clone (node->decl, node->count,
1677 false, vNULL, true, NULL, NULL);
1678 for (e = master_clone->callees; e; e = e->next_callee)
1679 if (!e->inline_failed)
1680 clone_inlined_nodes (e, true, false, NULL);
1681 curr->redirect_callee (master_clone);
1682 if (edge_growth_cache != NULL)
1683 edge_growth_cache->remove (curr);
1684 }
1685
1686 inline_call (curr, false, new_edges, &overall_size, true);
1687 reset_node_cache (node);
1688 lookup_recursive_calls (node, curr->callee, &heap);
1689 n++;
1690 }
1691
1692 if (!heap.empty () && dump_file)
1693 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1694
1695 if (!master_clone)
1696 return false;
1697
1698 if (dump_enabled_p ())
1699 dump_printf_loc (MSG_NOTE, edge->call_stmt,
1700 "\n Inlined %i times, "
1701 "body grown from size %i to %i, time %f to %f\n", n,
1702 ipa_size_summaries->get (master_clone)->size,
1703 ipa_size_summaries->get (node)->size,
1704 ipa_fn_summaries->get (master_clone)->time.to_double (),
1705 ipa_fn_summaries->get (node)->time.to_double ());
1706
1707 /* Remove master clone we used for inlining. We rely that clones inlined
1708 into master clone gets queued just before master clone so we don't
1709 need recursion. */
1710 for (node = symtab->first_function (); node != master_clone;
1711 node = next)
1712 {
1713 next = symtab->next_function (node);
1714 if (node->inlined_to == master_clone)
1715 node->remove ();
1716 }
1717 master_clone->remove ();
1718 return true;
1719 }
1720
1721
1722 /* Given whole compilation unit estimate of INSNS, compute how large we can
1723 allow the unit to grow. */
1724
1725 static int64_t
1726 compute_max_insns (cgraph_node *node, int insns)
1727 {
1728 int max_insns = insns;
1729 if (max_insns < opt_for_fn (node->decl, param_large_unit_insns))
1730 max_insns = opt_for_fn (node->decl, param_large_unit_insns);
1731
1732 return ((int64_t) max_insns
1733 * (100 + opt_for_fn (node->decl, param_inline_unit_growth)) / 100);
1734 }
1735
1736
1737 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1738
1739 static void
1740 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> new_edges)
1741 {
1742 while (new_edges.length () > 0)
1743 {
1744 struct cgraph_edge *edge = new_edges.pop ();
1745
1746 gcc_assert (!edge->aux);
1747 gcc_assert (edge->callee);
1748 if (edge->inline_failed
1749 && can_inline_edge_p (edge, true)
1750 && want_inline_small_function_p (edge, true)
1751 && can_inline_edge_by_limits_p (edge, true))
1752 edge->aux = heap->insert (edge_badness (edge, false), edge);
1753 }
1754 }
1755
1756 /* Remove EDGE from the fibheap. */
1757
1758 static void
1759 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1760 {
1761 if (e->aux)
1762 {
1763 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux);
1764 e->aux = NULL;
1765 }
1766 }
1767
1768 /* Return true if speculation of edge E seems useful.
1769 If ANTICIPATE_INLINING is true, be conservative and hope that E
1770 may get inlined. */
1771
1772 bool
1773 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1774 {
1775 /* If we have already decided to inline the edge, it seems useful. */
1776 if (!e->inline_failed)
1777 return true;
1778
1779 enum availability avail;
1780 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail,
1781 e->caller);
1782 struct cgraph_edge *direct, *indirect;
1783 struct ipa_ref *ref;
1784
1785 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1786
1787 if (!e->maybe_hot_p ())
1788 return false;
1789
1790 /* See if IP optimizations found something potentially useful about the
1791 function. For now we look only for CONST/PURE flags. Almost everything
1792 else we propagate is useless. */
1793 if (avail >= AVAIL_AVAILABLE)
1794 {
1795 int ecf_flags = flags_from_decl_or_type (target->decl);
1796 if (ecf_flags & ECF_CONST)
1797 {
1798 e->speculative_call_info (direct, indirect, ref);
1799 if (!(indirect->indirect_info->ecf_flags & ECF_CONST))
1800 return true;
1801 }
1802 else if (ecf_flags & ECF_PURE)
1803 {
1804 e->speculative_call_info (direct, indirect, ref);
1805 if (!(indirect->indirect_info->ecf_flags & ECF_PURE))
1806 return true;
1807 }
1808 }
1809 /* If we did not managed to inline the function nor redirect
1810 to an ipa-cp clone (that are seen by having local flag set),
1811 it is probably pointless to inline it unless hardware is missing
1812 indirect call predictor. */
1813 if (!anticipate_inlining && !target->local)
1814 return false;
1815 /* For overwritable targets there is not much to do. */
1816 if (!can_inline_edge_p (e, false)
1817 || !can_inline_edge_by_limits_p (e, false, true))
1818 return false;
1819 /* OK, speculation seems interesting. */
1820 return true;
1821 }
1822
1823 /* We know that EDGE is not going to be inlined.
1824 See if we can remove speculation. */
1825
1826 static void
1827 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge)
1828 {
1829 if (edge->speculative && !speculation_useful_p (edge, false))
1830 {
1831 struct cgraph_node *node = edge->caller;
1832 struct cgraph_node *where = node->inlined_to
1833 ? node->inlined_to : node;
1834 auto_bitmap updated_nodes;
1835
1836 if (edge->count.ipa ().initialized_p ())
1837 spec_rem += edge->count.ipa ();
1838 edge->resolve_speculation ();
1839 reset_edge_caches (where);
1840 ipa_update_overall_fn_summary (where);
1841 update_caller_keys (edge_heap, where,
1842 updated_nodes, NULL);
1843 update_callee_keys (edge_heap, where, NULL,
1844 updated_nodes);
1845 }
1846 }
1847
1848 /* Return true if NODE should be accounted for overall size estimate.
1849 Skip all nodes optimized for size so we can measure the growth of hot
1850 part of program no matter of the padding. */
1851
1852 bool
1853 inline_account_function_p (struct cgraph_node *node)
1854 {
1855 return (!DECL_EXTERNAL (node->decl)
1856 && !opt_for_fn (node->decl, optimize_size)
1857 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
1858 }
1859
1860 /* Count number of callers of NODE and store it into DATA (that
1861 points to int. Worker for cgraph_for_node_and_aliases. */
1862
1863 static bool
1864 sum_callers (struct cgraph_node *node, void *data)
1865 {
1866 struct cgraph_edge *e;
1867 int *num_calls = (int *)data;
1868
1869 for (e = node->callers; e; e = e->next_caller)
1870 (*num_calls)++;
1871 return false;
1872 }
1873
1874 /* We only propagate across edges with non-interposable callee. */
1875
1876 inline bool
1877 ignore_edge_p (struct cgraph_edge *e)
1878 {
1879 enum availability avail;
1880 e->callee->function_or_virtual_thunk_symbol (&avail, e->caller);
1881 return (avail <= AVAIL_INTERPOSABLE);
1882 }
1883
1884 /* We use greedy algorithm for inlining of small functions:
1885 All inline candidates are put into prioritized heap ordered in
1886 increasing badness.
1887
1888 The inlining of small functions is bounded by unit growth parameters. */
1889
1890 static void
1891 inline_small_functions (void)
1892 {
1893 struct cgraph_node *node;
1894 struct cgraph_edge *edge;
1895 edge_heap_t edge_heap (sreal::min ());
1896 auto_bitmap updated_nodes;
1897 int min_size;
1898 auto_vec<cgraph_edge *> new_indirect_edges;
1899 int initial_size = 0;
1900 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count);
1901 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1902 new_indirect_edges.create (8);
1903
1904 edge_removal_hook_holder
1905 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap);
1906
1907 /* Compute overall unit size and other global parameters used by badness
1908 metrics. */
1909
1910 max_count = profile_count::uninitialized ();
1911 ipa_reduced_postorder (order, true, ignore_edge_p);
1912 free (order);
1913
1914 FOR_EACH_DEFINED_FUNCTION (node)
1915 if (!node->inlined_to)
1916 {
1917 if (!node->alias && node->analyzed
1918 && (node->has_gimple_body_p () || node->thunk.thunk_p)
1919 && opt_for_fn (node->decl, optimize))
1920 {
1921 class ipa_fn_summary *info = ipa_fn_summaries->get (node);
1922 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux;
1923
1924 /* Do not account external functions, they will be optimized out
1925 if not inlined. Also only count the non-cold portion of program. */
1926 if (inline_account_function_p (node))
1927 initial_size += ipa_size_summaries->get (node)->size;
1928 info->growth = estimate_growth (node);
1929
1930 int num_calls = 0;
1931 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
1932 true);
1933 if (num_calls == 1)
1934 info->single_caller = true;
1935 if (dfs && dfs->next_cycle)
1936 {
1937 struct cgraph_node *n2;
1938 int id = dfs->scc_no + 1;
1939 for (n2 = node; n2;
1940 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle)
1941 if (opt_for_fn (n2->decl, optimize))
1942 {
1943 ipa_fn_summary *info2 = ipa_fn_summaries->get
1944 (n2->inlined_to ? n2->inlined_to : n2);
1945 if (info2->scc_no)
1946 break;
1947 info2->scc_no = id;
1948 }
1949 }
1950 }
1951
1952 for (edge = node->callers; edge; edge = edge->next_caller)
1953 max_count = max_count.max (edge->count.ipa ());
1954 }
1955 ipa_free_postorder_info ();
1956 initialize_growth_caches ();
1957
1958 if (dump_file)
1959 fprintf (dump_file,
1960 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1961 initial_size);
1962
1963 overall_size = initial_size;
1964 min_size = overall_size;
1965
1966 /* Populate the heap with all edges we might inline. */
1967
1968 FOR_EACH_DEFINED_FUNCTION (node)
1969 {
1970 bool update = false;
1971 struct cgraph_edge *next = NULL;
1972 bool has_speculative = false;
1973
1974 if (!opt_for_fn (node->decl, optimize))
1975 continue;
1976
1977 if (dump_file)
1978 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ());
1979
1980 for (edge = node->callees; edge; edge = edge->next_callee)
1981 {
1982 if (edge->inline_failed
1983 && !edge->aux
1984 && can_inline_edge_p (edge, true)
1985 && want_inline_small_function_p (edge, true)
1986 && can_inline_edge_by_limits_p (edge, true)
1987 && edge->inline_failed)
1988 {
1989 gcc_assert (!edge->aux);
1990 update_edge_key (&edge_heap, edge);
1991 }
1992 if (edge->speculative)
1993 has_speculative = true;
1994 }
1995 if (has_speculative)
1996 for (edge = node->callees; edge; edge = next)
1997 {
1998 next = edge->next_callee;
1999 if (edge->speculative
2000 && !speculation_useful_p (edge, edge->aux != NULL))
2001 {
2002 edge->resolve_speculation ();
2003 update = true;
2004 }
2005 }
2006 if (update)
2007 {
2008 struct cgraph_node *where = node->inlined_to
2009 ? node->inlined_to : node;
2010 ipa_update_overall_fn_summary (where);
2011 reset_edge_caches (where);
2012 update_caller_keys (&edge_heap, where,
2013 updated_nodes, NULL);
2014 update_callee_keys (&edge_heap, where, NULL,
2015 updated_nodes);
2016 bitmap_clear (updated_nodes);
2017 }
2018 }
2019
2020 gcc_assert (in_lto_p
2021 || !(max_count > 0)
2022 || (profile_info && flag_branch_probabilities));
2023
2024 while (!edge_heap.empty ())
2025 {
2026 int old_size = overall_size;
2027 struct cgraph_node *where, *callee;
2028 sreal badness = edge_heap.min_key ();
2029 sreal current_badness;
2030 int growth;
2031
2032 edge = edge_heap.extract_min ();
2033 gcc_assert (edge->aux);
2034 edge->aux = NULL;
2035 if (!edge->inline_failed || !edge->callee->analyzed)
2036 continue;
2037
2038 /* Be sure that caches are maintained consistent.
2039 This check is affected by scaling roundoff errors when compiling for
2040 IPA this we skip it in that case. */
2041 if (flag_checking && !edge->callee->count.ipa_p ()
2042 && (!max_count.initialized_p () || !max_count.nonzero_p ()))
2043 {
2044 sreal cached_badness = edge_badness (edge, false);
2045
2046 int old_size_est = estimate_edge_size (edge);
2047 sreal old_time_est = estimate_edge_time (edge);
2048 int old_hints_est = estimate_edge_hints (edge);
2049
2050 if (edge_growth_cache != NULL)
2051 edge_growth_cache->remove (edge);
2052 reset_node_cache (edge->caller->inlined_to
2053 ? edge->caller->inlined_to
2054 : edge->caller);
2055 gcc_assert (old_size_est == estimate_edge_size (edge));
2056 gcc_assert (old_time_est == estimate_edge_time (edge));
2057 /* FIXME:
2058
2059 gcc_assert (old_hints_est == estimate_edge_hints (edge));
2060
2061 fails with profile feedback because some hints depends on
2062 maybe_hot_edge_p predicate and because callee gets inlined to other
2063 calls, the edge may become cold.
2064 This ought to be fixed by computing relative probabilities
2065 for given invocation but that will be better done once whole
2066 code is converted to sreals. Disable for now and revert to "wrong"
2067 value so enable/disable checking paths agree. */
2068 edge_growth_cache->get (edge)->hints = old_hints_est + 1;
2069
2070 /* When updating the edge costs, we only decrease badness in the keys.
2071 Increases of badness are handled lazily; when we see key with out
2072 of date value on it, we re-insert it now. */
2073 current_badness = edge_badness (edge, false);
2074 gcc_assert (cached_badness == current_badness);
2075 gcc_assert (current_badness >= badness);
2076 }
2077 else
2078 current_badness = edge_badness (edge, false);
2079 if (current_badness != badness)
2080 {
2081 if (edge_heap.min () && current_badness > edge_heap.min_key ())
2082 {
2083 edge->aux = edge_heap.insert (current_badness, edge);
2084 continue;
2085 }
2086 else
2087 badness = current_badness;
2088 }
2089
2090 if (!can_inline_edge_p (edge, true)
2091 || !can_inline_edge_by_limits_p (edge, true))
2092 {
2093 resolve_noninline_speculation (&edge_heap, edge);
2094 continue;
2095 }
2096
2097 callee = edge->callee->ultimate_alias_target ();
2098 growth = estimate_edge_growth (edge);
2099 if (dump_file)
2100 {
2101 fprintf (dump_file,
2102 "\nConsidering %s with %i size\n",
2103 callee->dump_name (),
2104 ipa_size_summaries->get (callee)->size);
2105 fprintf (dump_file,
2106 " to be inlined into %s in %s:%i\n"
2107 " Estimated badness is %f, frequency %.2f.\n",
2108 edge->caller->dump_name (),
2109 edge->call_stmt
2110 && (LOCATION_LOCUS (gimple_location ((const gimple *)
2111 edge->call_stmt))
2112 > BUILTINS_LOCATION)
2113 ? gimple_filename ((const gimple *) edge->call_stmt)
2114 : "unknown",
2115 edge->call_stmt
2116 ? gimple_lineno ((const gimple *) edge->call_stmt)
2117 : -1,
2118 badness.to_double (),
2119 edge->sreal_frequency ().to_double ());
2120 if (edge->count.ipa ().initialized_p ())
2121 {
2122 fprintf (dump_file, " Called ");
2123 edge->count.ipa ().dump (dump_file);
2124 fprintf (dump_file, " times\n");
2125 }
2126 if (dump_flags & TDF_DETAILS)
2127 edge_badness (edge, true);
2128 }
2129
2130 where = edge->caller;
2131
2132 if (overall_size + growth > compute_max_insns (where, min_size)
2133 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2134 {
2135 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
2136 report_inline_failed_reason (edge);
2137 resolve_noninline_speculation (&edge_heap, edge);
2138 continue;
2139 }
2140
2141 if (!want_inline_small_function_p (edge, true))
2142 {
2143 resolve_noninline_speculation (&edge_heap, edge);
2144 continue;
2145 }
2146
2147 profile_count old_count = callee->count;
2148
2149 /* Heuristics for inlining small functions work poorly for
2150 recursive calls where we do effects similar to loop unrolling.
2151 When inlining such edge seems profitable, leave decision on
2152 specific inliner. */
2153 if (edge->recursive_p ())
2154 {
2155 if (where->inlined_to)
2156 where = where->inlined_to;
2157 if (!recursive_inlining (edge,
2158 opt_for_fn (edge->caller->decl,
2159 flag_indirect_inlining)
2160 ? &new_indirect_edges : NULL))
2161 {
2162 edge->inline_failed = CIF_RECURSIVE_INLINING;
2163 resolve_noninline_speculation (&edge_heap, edge);
2164 continue;
2165 }
2166 reset_edge_caches (where);
2167 /* Recursive inliner inlines all recursive calls of the function
2168 at once. Consequently we need to update all callee keys. */
2169 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining))
2170 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2171 update_callee_keys (&edge_heap, where, where, updated_nodes);
2172 bitmap_clear (updated_nodes);
2173 }
2174 else
2175 {
2176 struct cgraph_node *outer_node = NULL;
2177 int depth = 0;
2178
2179 /* Consider the case where self recursive function A is inlined
2180 into B. This is desired optimization in some cases, since it
2181 leads to effect similar of loop peeling and we might completely
2182 optimize out the recursive call. However we must be extra
2183 selective. */
2184
2185 where = edge->caller;
2186 while (where->inlined_to)
2187 {
2188 if (where->decl == callee->decl)
2189 outer_node = where, depth++;
2190 where = where->callers->caller;
2191 }
2192 if (outer_node
2193 && !want_inline_self_recursive_call_p (edge, outer_node,
2194 true, depth))
2195 {
2196 edge->inline_failed
2197 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl)
2198 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
2199 resolve_noninline_speculation (&edge_heap, edge);
2200 continue;
2201 }
2202 else if (depth && dump_file)
2203 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
2204
2205 gcc_checking_assert (!callee->inlined_to);
2206
2207 int old_size = ipa_size_summaries->get (where)->size;
2208 sreal old_time = ipa_fn_summaries->get (where)->time;
2209
2210 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
2211 reset_edge_caches (edge->callee);
2212 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2213
2214 /* If caller's size and time increased we do not need to update
2215 all edges because badness is not going to decrease. */
2216 if (old_size <= ipa_size_summaries->get (where)->size
2217 && old_time <= ipa_fn_summaries->get (where)->time
2218 /* Wrapper penalty may be non-monotonous in this respect.
2219 Fortunately it only affects small functions. */
2220 && !wrapper_heuristics_may_apply (where, old_size))
2221 update_callee_keys (&edge_heap, edge->callee, edge->callee,
2222 updated_nodes);
2223 else
2224 update_callee_keys (&edge_heap, where,
2225 edge->callee,
2226 updated_nodes);
2227 }
2228 where = edge->caller;
2229 if (where->inlined_to)
2230 where = where->inlined_to;
2231
2232 /* Our profitability metric can depend on local properties
2233 such as number of inlinable calls and size of the function body.
2234 After inlining these properties might change for the function we
2235 inlined into (since it's body size changed) and for the functions
2236 called by function we inlined (since number of it inlinable callers
2237 might change). */
2238 update_caller_keys (&edge_heap, where, updated_nodes, NULL);
2239 /* Offline copy count has possibly changed, recompute if profile is
2240 available. */
2241 struct cgraph_node *n
2242 = cgraph_node::get (edge->callee->decl)->ultimate_alias_target ();
2243 if (n != edge->callee && n->analyzed && !(n->count == old_count)
2244 && n->count.ipa_p ())
2245 update_callee_keys (&edge_heap, n, NULL, updated_nodes);
2246 bitmap_clear (updated_nodes);
2247
2248 if (dump_enabled_p ())
2249 {
2250 ipa_fn_summary *s = ipa_fn_summaries->get (where);
2251
2252 /* dump_printf can't handle %+i. */
2253 char buf_net_change[100];
2254 snprintf (buf_net_change, sizeof buf_net_change, "%+i",
2255 overall_size - old_size);
2256
2257 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt,
2258 " Inlined %C into %C which now has time %f and "
2259 "size %i, net change of %s%s.\n",
2260 edge->callee, edge->caller,
2261 s->time.to_double (),
2262 ipa_size_summaries->get (edge->caller)->size,
2263 buf_net_change,
2264 cross_module_call_p (edge) ? " (cross module)":"");
2265 }
2266 if (min_size > overall_size)
2267 {
2268 min_size = overall_size;
2269
2270 if (dump_file)
2271 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
2272 }
2273 }
2274
2275 free_growth_caches ();
2276 if (dump_enabled_p ())
2277 dump_printf (MSG_NOTE,
2278 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2279 initial_size, overall_size,
2280 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
2281 symtab->remove_edge_removal_hook (edge_removal_hook_holder);
2282 }
2283
2284 /* Flatten NODE. Performed both during early inlining and
2285 at IPA inlining time. */
2286
2287 static void
2288 flatten_function (struct cgraph_node *node, bool early, bool update)
2289 {
2290 struct cgraph_edge *e;
2291
2292 /* We shouldn't be called recursively when we are being processed. */
2293 gcc_assert (node->aux == NULL);
2294
2295 node->aux = (void *) node;
2296
2297 for (e = node->callees; e; e = e->next_callee)
2298 {
2299 struct cgraph_node *orig_callee;
2300 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2301
2302 /* We've hit cycle? It is time to give up. */
2303 if (callee->aux)
2304 {
2305 if (dump_enabled_p ())
2306 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2307 "Not inlining %C into %C to avoid cycle.\n",
2308 callee, e->caller);
2309 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR)
2310 e->inline_failed = CIF_RECURSIVE_INLINING;
2311 continue;
2312 }
2313
2314 /* When the edge is already inlined, we just need to recurse into
2315 it in order to fully flatten the leaves. */
2316 if (!e->inline_failed)
2317 {
2318 flatten_function (callee, early, false);
2319 continue;
2320 }
2321
2322 /* Flatten attribute needs to be processed during late inlining. For
2323 extra code quality we however do flattening during early optimization,
2324 too. */
2325 if (!early
2326 ? !can_inline_edge_p (e, true)
2327 && !can_inline_edge_by_limits_p (e, true)
2328 : !can_early_inline_edge_p (e))
2329 continue;
2330
2331 if (e->recursive_p ())
2332 {
2333 if (dump_enabled_p ())
2334 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2335 "Not inlining: recursive call.\n");
2336 continue;
2337 }
2338
2339 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
2340 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
2341 {
2342 if (dump_enabled_p ())
2343 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2344 "Not inlining: SSA form does not match.\n");
2345 continue;
2346 }
2347
2348 /* Inline the edge and flatten the inline clone. Avoid
2349 recursing through the original node if the node was cloned. */
2350 if (dump_enabled_p ())
2351 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2352 " Inlining %C into %C.\n",
2353 callee, e->caller);
2354 orig_callee = callee;
2355 inline_call (e, true, NULL, NULL, false);
2356 if (e->callee != orig_callee)
2357 orig_callee->aux = (void *) node;
2358 flatten_function (e->callee, early, false);
2359 if (e->callee != orig_callee)
2360 orig_callee->aux = NULL;
2361 }
2362
2363 node->aux = NULL;
2364 cgraph_node *where = node->inlined_to ? node->inlined_to : node;
2365 if (update && opt_for_fn (where->decl, optimize))
2366 ipa_update_overall_fn_summary (where);
2367 }
2368
2369 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2370 DATA points to number of calls originally found so we avoid infinite
2371 recursion. */
2372
2373 static bool
2374 inline_to_all_callers_1 (struct cgraph_node *node, void *data,
2375 hash_set<cgraph_node *> *callers)
2376 {
2377 int *num_calls = (int *)data;
2378 bool callee_removed = false;
2379
2380 while (node->callers && !node->inlined_to)
2381 {
2382 struct cgraph_node *caller = node->callers->caller;
2383
2384 if (!can_inline_edge_p (node->callers, true)
2385 || !can_inline_edge_by_limits_p (node->callers, true)
2386 || node->callers->recursive_p ())
2387 {
2388 if (dump_file)
2389 fprintf (dump_file, "Uninlinable call found; giving up.\n");
2390 *num_calls = 0;
2391 return false;
2392 }
2393
2394 if (dump_file)
2395 {
2396 cgraph_node *ultimate = node->ultimate_alias_target ();
2397 fprintf (dump_file,
2398 "\nInlining %s size %i.\n",
2399 ultimate->name (),
2400 ipa_size_summaries->get (ultimate)->size);
2401 fprintf (dump_file,
2402 " Called once from %s %i insns.\n",
2403 node->callers->caller->name (),
2404 ipa_size_summaries->get (node->callers->caller)->size);
2405 }
2406
2407 /* Remember which callers we inlined to, delaying updating the
2408 overall summary. */
2409 callers->add (node->callers->caller);
2410 inline_call (node->callers, true, NULL, NULL, false, &callee_removed);
2411 if (dump_file)
2412 fprintf (dump_file,
2413 " Inlined into %s which now has %i size\n",
2414 caller->name (),
2415 ipa_size_summaries->get (caller)->size);
2416 if (!(*num_calls)--)
2417 {
2418 if (dump_file)
2419 fprintf (dump_file, "New calls found; giving up.\n");
2420 return callee_removed;
2421 }
2422 if (callee_removed)
2423 return true;
2424 }
2425 return false;
2426 }
2427
2428 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2429 update. */
2430
2431 static bool
2432 inline_to_all_callers (struct cgraph_node *node, void *data)
2433 {
2434 hash_set<cgraph_node *> callers;
2435 bool res = inline_to_all_callers_1 (node, data, &callers);
2436 /* Perform the delayed update of the overall summary of all callers
2437 processed. This avoids quadratic behavior in the cases where
2438 we have a lot of calls to the same function. */
2439 for (hash_set<cgraph_node *>::iterator i = callers.begin ();
2440 i != callers.end (); ++i)
2441 ipa_update_overall_fn_summary ((*i)->inlined_to ? (*i)->inlined_to : *i);
2442 return res;
2443 }
2444
2445 /* Output overall time estimate. */
2446 static void
2447 dump_overall_stats (void)
2448 {
2449 sreal sum_weighted = 0, sum = 0;
2450 struct cgraph_node *node;
2451
2452 FOR_EACH_DEFINED_FUNCTION (node)
2453 if (!node->inlined_to
2454 && !node->alias)
2455 {
2456 ipa_fn_summary *s = ipa_fn_summaries->get (node);
2457 if (s != NULL)
2458 {
2459 sum += s->time;
2460 if (node->count.ipa ().initialized_p ())
2461 sum_weighted += s->time * node->count.ipa ().to_gcov_type ();
2462 }
2463 }
2464 fprintf (dump_file, "Overall time estimate: "
2465 "%f weighted by profile: "
2466 "%f\n", sum.to_double (), sum_weighted.to_double ());
2467 }
2468
2469 /* Output some useful stats about inlining. */
2470
2471 static void
2472 dump_inline_stats (void)
2473 {
2474 int64_t inlined_cnt = 0, inlined_indir_cnt = 0;
2475 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0;
2476 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0;
2477 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0;
2478 int64_t inlined_speculative = 0, inlined_speculative_ply = 0;
2479 int64_t indirect_poly_cnt = 0, indirect_cnt = 0;
2480 int64_t reason[CIF_N_REASONS][2];
2481 sreal reason_freq[CIF_N_REASONS];
2482 int i;
2483 struct cgraph_node *node;
2484
2485 memset (reason, 0, sizeof (reason));
2486 for (i=0; i < CIF_N_REASONS; i++)
2487 reason_freq[i] = 0;
2488 FOR_EACH_DEFINED_FUNCTION (node)
2489 {
2490 struct cgraph_edge *e;
2491 for (e = node->callees; e; e = e->next_callee)
2492 {
2493 if (e->inline_failed)
2494 {
2495 if (e->count.ipa ().initialized_p ())
2496 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type ();
2497 reason_freq[(int) e->inline_failed] += e->sreal_frequency ();
2498 reason[(int) e->inline_failed][1] ++;
2499 if (DECL_VIRTUAL_P (e->callee->decl)
2500 && e->count.ipa ().initialized_p ())
2501 {
2502 if (e->indirect_inlining_edge)
2503 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2504 else
2505 noninlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2506 }
2507 else if (e->count.ipa ().initialized_p ())
2508 {
2509 if (e->indirect_inlining_edge)
2510 noninlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2511 else
2512 noninlined_cnt += e->count.ipa ().to_gcov_type ();
2513 }
2514 }
2515 else if (e->count.ipa ().initialized_p ())
2516 {
2517 if (e->speculative)
2518 {
2519 if (DECL_VIRTUAL_P (e->callee->decl))
2520 inlined_speculative_ply += e->count.ipa ().to_gcov_type ();
2521 else
2522 inlined_speculative += e->count.ipa ().to_gcov_type ();
2523 }
2524 else if (DECL_VIRTUAL_P (e->callee->decl))
2525 {
2526 if (e->indirect_inlining_edge)
2527 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2528 else
2529 inlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2530 }
2531 else
2532 {
2533 if (e->indirect_inlining_edge)
2534 inlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2535 else
2536 inlined_cnt += e->count.ipa ().to_gcov_type ();
2537 }
2538 }
2539 }
2540 for (e = node->indirect_calls; e; e = e->next_callee)
2541 if (e->indirect_info->polymorphic
2542 & e->count.ipa ().initialized_p ())
2543 indirect_poly_cnt += e->count.ipa ().to_gcov_type ();
2544 else if (e->count.ipa ().initialized_p ())
2545 indirect_cnt += e->count.ipa ().to_gcov_type ();
2546 }
2547 if (max_count.initialized_p ())
2548 {
2549 fprintf (dump_file,
2550 "Inlined %" PRId64 " + speculative "
2551 "%" PRId64 " + speculative polymorphic "
2552 "%" PRId64 " + previously indirect "
2553 "%" PRId64 " + virtual "
2554 "%" PRId64 " + virtual and previously indirect "
2555 "%" PRId64 "\n" "Not inlined "
2556 "%" PRId64 " + previously indirect "
2557 "%" PRId64 " + virtual "
2558 "%" PRId64 " + virtual and previously indirect "
2559 "%" PRId64 " + still indirect "
2560 "%" PRId64 " + still indirect polymorphic "
2561 "%" PRId64 "\n", inlined_cnt,
2562 inlined_speculative, inlined_speculative_ply,
2563 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt,
2564 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt,
2565 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt);
2566 fprintf (dump_file, "Removed speculations ");
2567 spec_rem.dump (dump_file);
2568 fprintf (dump_file, "\n");
2569 }
2570 dump_overall_stats ();
2571 fprintf (dump_file, "\nWhy inlining failed?\n");
2572 for (i = 0; i < CIF_N_REASONS; i++)
2573 if (reason[i][1])
2574 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n",
2575 cgraph_inline_failed_string ((cgraph_inline_failed_t) i),
2576 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]);
2577 }
2578
2579 /* Called when node is removed. */
2580
2581 static void
2582 flatten_remove_node_hook (struct cgraph_node *node, void *data)
2583 {
2584 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL)
2585 return;
2586
2587 hash_set<struct cgraph_node *> *removed
2588 = (hash_set<struct cgraph_node *> *) data;
2589 removed->add (node);
2590 }
2591
2592 /* Decide on the inlining. We do so in the topological order to avoid
2593 expenses on updating data structures. */
2594
2595 static unsigned int
2596 ipa_inline (void)
2597 {
2598 struct cgraph_node *node;
2599 int nnodes;
2600 struct cgraph_node **order;
2601 int i, j;
2602 int cold;
2603 bool remove_functions = false;
2604
2605 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
2606
2607 if (dump_file)
2608 ipa_dump_fn_summaries (dump_file);
2609
2610 nnodes = ipa_reverse_postorder (order);
2611 spec_rem = profile_count::zero ();
2612
2613 FOR_EACH_FUNCTION (node)
2614 {
2615 node->aux = 0;
2616
2617 /* Recompute the default reasons for inlining because they may have
2618 changed during merging. */
2619 if (in_lto_p)
2620 {
2621 for (cgraph_edge *e = node->callees; e; e = e->next_callee)
2622 {
2623 gcc_assert (e->inline_failed);
2624 initialize_inline_failed (e);
2625 }
2626 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
2627 initialize_inline_failed (e);
2628 }
2629 }
2630
2631 if (dump_file)
2632 fprintf (dump_file, "\nFlattening functions:\n");
2633
2634 /* First shrink order array, so that it only contains nodes with
2635 flatten attribute. */
2636 for (i = nnodes - 1, j = i; i >= 0; i--)
2637 {
2638 node = order[i];
2639 if (node->definition
2640 && lookup_attribute ("flatten",
2641 DECL_ATTRIBUTES (node->decl)) != NULL)
2642 order[j--] = order[i];
2643 }
2644
2645 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain
2646 nodes with flatten attribute. If there is more than one such
2647 node, we need to register a node removal hook, as flatten_function
2648 could remove other nodes with flatten attribute. See PR82801. */
2649 struct cgraph_node_hook_list *node_removal_hook_holder = NULL;
2650 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL;
2651 if (j < nnodes - 2)
2652 {
2653 flatten_removed_nodes = new hash_set<struct cgraph_node *>;
2654 node_removal_hook_holder
2655 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook,
2656 flatten_removed_nodes);
2657 }
2658
2659 /* In the first pass handle functions to be flattened. Do this with
2660 a priority so none of our later choices will make this impossible. */
2661 for (i = nnodes - 1; i > j; i--)
2662 {
2663 node = order[i];
2664 if (flatten_removed_nodes
2665 && flatten_removed_nodes->contains (node))
2666 continue;
2667
2668 /* Handle nodes to be flattened.
2669 Ideally when processing callees we stop inlining at the
2670 entry of cycles, possibly cloning that entry point and
2671 try to flatten itself turning it into a self-recursive
2672 function. */
2673 if (dump_file)
2674 fprintf (dump_file, "Flattening %s\n", node->name ());
2675 flatten_function (node, false, true);
2676 }
2677
2678 if (j < nnodes - 2)
2679 {
2680 symtab->remove_cgraph_removal_hook (node_removal_hook_holder);
2681 delete flatten_removed_nodes;
2682 }
2683 free (order);
2684
2685 if (dump_file)
2686 dump_overall_stats ();
2687
2688 inline_small_functions ();
2689
2690 gcc_assert (symtab->state == IPA_SSA);
2691 symtab->state = IPA_SSA_AFTER_INLINING;
2692 /* Do first after-inlining removal. We want to remove all "stale" extern
2693 inline functions and virtual functions so we really know what is called
2694 once. */
2695 symtab->remove_unreachable_nodes (dump_file);
2696
2697 /* Inline functions with a property that after inlining into all callers the
2698 code size will shrink because the out-of-line copy is eliminated.
2699 We do this regardless on the callee size as long as function growth limits
2700 are met. */
2701 if (dump_file)
2702 fprintf (dump_file,
2703 "\nDeciding on functions to be inlined into all callers and "
2704 "removing useless speculations:\n");
2705
2706 /* Inlining one function called once has good chance of preventing
2707 inlining other function into the same callee. Ideally we should
2708 work in priority order, but probably inlining hot functions first
2709 is good cut without the extra pain of maintaining the queue.
2710
2711 ??? this is not really fitting the bill perfectly: inlining function
2712 into callee often leads to better optimization of callee due to
2713 increased context for optimization.
2714 For example if main() function calls a function that outputs help
2715 and then function that does the main optimization, we should inline
2716 the second with priority even if both calls are cold by themselves.
2717
2718 We probably want to implement new predicate replacing our use of
2719 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2720 to be hot. */
2721 for (cold = 0; cold <= 1; cold ++)
2722 {
2723 FOR_EACH_DEFINED_FUNCTION (node)
2724 {
2725 struct cgraph_edge *edge, *next;
2726 bool update=false;
2727
2728 if (!opt_for_fn (node->decl, optimize)
2729 || !opt_for_fn (node->decl, flag_inline_functions_called_once))
2730 continue;
2731
2732 for (edge = node->callees; edge; edge = next)
2733 {
2734 next = edge->next_callee;
2735 if (edge->speculative && !speculation_useful_p (edge, false))
2736 {
2737 if (edge->count.ipa ().initialized_p ())
2738 spec_rem += edge->count.ipa ();
2739 edge->resolve_speculation ();
2740 update = true;
2741 remove_functions = true;
2742 }
2743 }
2744 if (update)
2745 {
2746 struct cgraph_node *where = node->inlined_to
2747 ? node->inlined_to : node;
2748 reset_edge_caches (where);
2749 ipa_update_overall_fn_summary (where);
2750 }
2751 if (want_inline_function_to_all_callers_p (node, cold))
2752 {
2753 int num_calls = 0;
2754 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
2755 true);
2756 while (node->call_for_symbol_and_aliases
2757 (inline_to_all_callers, &num_calls, true))
2758 ;
2759 remove_functions = true;
2760 }
2761 }
2762 }
2763
2764 /* Free ipa-prop structures if they are no longer needed. */
2765 ipa_free_all_structures_after_iinln ();
2766
2767 if (dump_enabled_p ())
2768 dump_printf (MSG_NOTE,
2769 "\nInlined %i calls, eliminated %i functions\n\n",
2770 ncalls_inlined, nfunctions_inlined);
2771 if (dump_file)
2772 dump_inline_stats ();
2773
2774 if (dump_file)
2775 ipa_dump_fn_summaries (dump_file);
2776 return remove_functions ? TODO_remove_functions : 0;
2777 }
2778
2779 /* Inline always-inline function calls in NODE. */
2780
2781 static bool
2782 inline_always_inline_functions (struct cgraph_node *node)
2783 {
2784 struct cgraph_edge *e;
2785 bool inlined = false;
2786
2787 for (e = node->callees; e; e = e->next_callee)
2788 {
2789 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2790 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2791 continue;
2792
2793 if (e->recursive_p ())
2794 {
2795 if (dump_enabled_p ())
2796 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2797 " Not inlining recursive call to %C.\n",
2798 e->callee);
2799 e->inline_failed = CIF_RECURSIVE_INLINING;
2800 continue;
2801 }
2802
2803 if (!can_early_inline_edge_p (e))
2804 {
2805 /* Set inlined to true if the callee is marked "always_inline" but
2806 is not inlinable. This will allow flagging an error later in
2807 expand_call_inline in tree-inline.c. */
2808 if (lookup_attribute ("always_inline",
2809 DECL_ATTRIBUTES (callee->decl)) != NULL)
2810 inlined = true;
2811 continue;
2812 }
2813
2814 if (dump_enabled_p ())
2815 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2816 " Inlining %C into %C (always_inline).\n",
2817 e->callee, e->caller);
2818 inline_call (e, true, NULL, NULL, false);
2819 inlined = true;
2820 }
2821 if (inlined)
2822 ipa_update_overall_fn_summary (node);
2823
2824 return inlined;
2825 }
2826
2827 /* Decide on the inlining. We do so in the topological order to avoid
2828 expenses on updating data structures. */
2829
2830 static bool
2831 early_inline_small_functions (struct cgraph_node *node)
2832 {
2833 struct cgraph_edge *e;
2834 bool inlined = false;
2835
2836 for (e = node->callees; e; e = e->next_callee)
2837 {
2838 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2839
2840 /* We can encounter not-yet-analyzed function during
2841 early inlining on callgraphs with strongly
2842 connected components. */
2843 ipa_fn_summary *s = ipa_fn_summaries->get (callee);
2844 if (s == NULL || !s->inlinable || !e->inline_failed)
2845 continue;
2846
2847 /* Do not consider functions not declared inline. */
2848 if (!DECL_DECLARED_INLINE_P (callee->decl)
2849 && !opt_for_fn (node->decl, flag_inline_small_functions)
2850 && !opt_for_fn (node->decl, flag_inline_functions))
2851 continue;
2852
2853 if (dump_enabled_p ())
2854 dump_printf_loc (MSG_NOTE, e->call_stmt,
2855 "Considering inline candidate %C.\n",
2856 callee);
2857
2858 if (!can_early_inline_edge_p (e))
2859 continue;
2860
2861 if (e->recursive_p ())
2862 {
2863 if (dump_enabled_p ())
2864 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2865 " Not inlining: recursive call.\n");
2866 continue;
2867 }
2868
2869 if (!want_early_inline_function_p (e))
2870 continue;
2871
2872 if (dump_enabled_p ())
2873 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2874 " Inlining %C into %C.\n",
2875 callee, e->caller);
2876 inline_call (e, true, NULL, NULL, false);
2877 inlined = true;
2878 }
2879
2880 if (inlined)
2881 ipa_update_overall_fn_summary (node);
2882
2883 return inlined;
2884 }
2885
2886 unsigned int
2887 early_inliner (function *fun)
2888 {
2889 struct cgraph_node *node = cgraph_node::get (current_function_decl);
2890 struct cgraph_edge *edge;
2891 unsigned int todo = 0;
2892 int iterations = 0;
2893 bool inlined = false;
2894
2895 if (seen_error ())
2896 return 0;
2897
2898 /* Do nothing if datastructures for ipa-inliner are already computed. This
2899 happens when some pass decides to construct new function and
2900 cgraph_add_new_function calls lowering passes and early optimization on
2901 it. This may confuse ourself when early inliner decide to inline call to
2902 function clone, because function clones don't have parameter list in
2903 ipa-prop matching their signature. */
2904 if (ipa_node_params_sum)
2905 return 0;
2906
2907 if (flag_checking)
2908 node->verify ();
2909 node->remove_all_references ();
2910
2911 /* Even when not optimizing or not inlining inline always-inline
2912 functions. */
2913 inlined = inline_always_inline_functions (node);
2914
2915 if (!optimize
2916 || flag_no_inline
2917 || !flag_early_inlining
2918 /* Never inline regular functions into always-inline functions
2919 during incremental inlining. This sucks as functions calling
2920 always inline functions will get less optimized, but at the
2921 same time inlining of functions calling always inline
2922 function into an always inline function might introduce
2923 cycles of edges to be always inlined in the callgraph.
2924
2925 We might want to be smarter and just avoid this type of inlining. */
2926 || (DECL_DISREGARD_INLINE_LIMITS (node->decl)
2927 && lookup_attribute ("always_inline",
2928 DECL_ATTRIBUTES (node->decl))))
2929 ;
2930 else if (lookup_attribute ("flatten",
2931 DECL_ATTRIBUTES (node->decl)) != NULL)
2932 {
2933 /* When the function is marked to be flattened, recursively inline
2934 all calls in it. */
2935 if (dump_enabled_p ())
2936 dump_printf (MSG_OPTIMIZED_LOCATIONS,
2937 "Flattening %C\n", node);
2938 flatten_function (node, true, true);
2939 inlined = true;
2940 }
2941 else
2942 {
2943 /* If some always_inline functions was inlined, apply the changes.
2944 This way we will not account always inline into growth limits and
2945 moreover we will inline calls from always inlines that we skipped
2946 previously because of conditional above. */
2947 if (inlined)
2948 {
2949 timevar_push (TV_INTEGRATION);
2950 todo |= optimize_inline_calls (current_function_decl);
2951 /* optimize_inline_calls call above might have introduced new
2952 statements that don't have inline parameters computed. */
2953 for (edge = node->callees; edge; edge = edge->next_callee)
2954 {
2955 /* We can enounter not-yet-analyzed function during
2956 early inlining on callgraphs with strongly
2957 connected components. */
2958 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2959 es->call_stmt_size
2960 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2961 es->call_stmt_time
2962 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2963 }
2964 ipa_update_overall_fn_summary (node);
2965 inlined = false;
2966 timevar_pop (TV_INTEGRATION);
2967 }
2968 /* We iterate incremental inlining to get trivial cases of indirect
2969 inlining. */
2970 while (iterations < 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 < param_early_inliner_max_iterations - 1)
2990 ipa_update_overall_fn_summary (node);
2991 timevar_pop (TV_INTEGRATION);
2992 iterations++;
2993 inlined = false;
2994 }
2995 if (dump_file)
2996 fprintf (dump_file, "Iterations: %i\n", iterations);
2997 }
2998
2999 if (inlined)
3000 {
3001 timevar_push (TV_INTEGRATION);
3002 todo |= optimize_inline_calls (current_function_decl);
3003 timevar_pop (TV_INTEGRATION);
3004 }
3005
3006 fun->always_inline_functions_inlined = true;
3007
3008 return todo;
3009 }
3010
3011 /* Do inlining of small functions. Doing so early helps profiling and other
3012 passes to be somewhat more effective and avoids some code duplication in
3013 later real inlining pass for testcases with very many function calls. */
3014
3015 namespace {
3016
3017 const pass_data pass_data_early_inline =
3018 {
3019 GIMPLE_PASS, /* type */
3020 "einline", /* name */
3021 OPTGROUP_INLINE, /* optinfo_flags */
3022 TV_EARLY_INLINING, /* tv_id */
3023 PROP_ssa, /* properties_required */
3024 0, /* properties_provided */
3025 0, /* properties_destroyed */
3026 0, /* todo_flags_start */
3027 0, /* todo_flags_finish */
3028 };
3029
3030 class pass_early_inline : public gimple_opt_pass
3031 {
3032 public:
3033 pass_early_inline (gcc::context *ctxt)
3034 : gimple_opt_pass (pass_data_early_inline, ctxt)
3035 {}
3036
3037 /* opt_pass methods: */
3038 virtual unsigned int execute (function *);
3039
3040 }; // class pass_early_inline
3041
3042 unsigned int
3043 pass_early_inline::execute (function *fun)
3044 {
3045 return early_inliner (fun);
3046 }
3047
3048 } // anon namespace
3049
3050 gimple_opt_pass *
3051 make_pass_early_inline (gcc::context *ctxt)
3052 {
3053 return new pass_early_inline (ctxt);
3054 }
3055
3056 namespace {
3057
3058 const pass_data pass_data_ipa_inline =
3059 {
3060 IPA_PASS, /* type */
3061 "inline", /* name */
3062 OPTGROUP_INLINE, /* optinfo_flags */
3063 TV_IPA_INLINING, /* tv_id */
3064 0, /* properties_required */
3065 0, /* properties_provided */
3066 0, /* properties_destroyed */
3067 0, /* todo_flags_start */
3068 ( TODO_dump_symtab ), /* todo_flags_finish */
3069 };
3070
3071 class pass_ipa_inline : public ipa_opt_pass_d
3072 {
3073 public:
3074 pass_ipa_inline (gcc::context *ctxt)
3075 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt,
3076 NULL, /* generate_summary */
3077 NULL, /* write_summary */
3078 NULL, /* read_summary */
3079 NULL, /* write_optimization_summary */
3080 NULL, /* read_optimization_summary */
3081 NULL, /* stmt_fixup */
3082 0, /* function_transform_todo_flags_start */
3083 inline_transform, /* function_transform */
3084 NULL) /* variable_transform */
3085 {}
3086
3087 /* opt_pass methods: */
3088 virtual unsigned int execute (function *) { return ipa_inline (); }
3089
3090 }; // class pass_ipa_inline
3091
3092 } // anon namespace
3093
3094 ipa_opt_pass_d *
3095 make_pass_ipa_inline (gcc::context *ctxt)
3096 {
3097 return new pass_ipa_inline (ctxt);
3098 }