1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2022 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
caller_growth_limits(struct cgraph_edge * e)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
report_inline_failed_reason(struct cgraph_edge * e)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
sanitize_attrs_match_for_inline_p(const_tree caller,const_tree callee)262 sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
263 {
264 if (!caller || !callee)
265 return true;
266
267 /* Follow clang and allow inlining for always_inline functions. */
268 if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
269 return true;
270
271 const sanitize_code codes[] =
272 {
273 SANITIZE_ADDRESS,
274 SANITIZE_THREAD,
275 SANITIZE_UNDEFINED,
276 SANITIZE_UNDEFINED_NONDEFAULT,
277 SANITIZE_POINTER_COMPARE,
278 SANITIZE_POINTER_SUBTRACT
279 };
280
281 for (unsigned i = 0; i < sizeof (codes) / sizeof (codes[0]); i++)
282 if (sanitize_flags_p (codes[i], caller)
283 != sanitize_flags_p (codes[i], callee))
284 return false;
285
286 if (sanitize_coverage_p (caller) != sanitize_coverage_p (callee))
287 return false;
288
289 return true;
290 }
291
292 /* Used for flags where it is safe to inline when caller's value is
293 grater than callee's. */
294 #define check_maybe_up(flag) \
295 (opts_for_fn (caller->decl)->x_##flag \
296 != opts_for_fn (callee->decl)->x_##flag \
297 && (!always_inline \
298 || opts_for_fn (caller->decl)->x_##flag \
299 < opts_for_fn (callee->decl)->x_##flag))
300 /* Used for flags where it is safe to inline when caller's value is
301 smaller than callee's. */
302 #define check_maybe_down(flag) \
303 (opts_for_fn (caller->decl)->x_##flag \
304 != opts_for_fn (callee->decl)->x_##flag \
305 && (!always_inline \
306 || opts_for_fn (caller->decl)->x_##flag \
307 > opts_for_fn (callee->decl)->x_##flag))
308 /* Used for flags where exact match is needed for correctness. */
309 #define check_match(flag) \
310 (opts_for_fn (caller->decl)->x_##flag \
311 != opts_for_fn (callee->decl)->x_##flag)
312
313 /* Decide if we can inline the edge and possibly update
314 inline_failed reason.
315 We check whether inlining is possible at all and whether
316 caller growth limits allow doing so.
317
318 if REPORT is true, output reason to the dump file. */
319
320 static bool
can_inline_edge_p(struct cgraph_edge * e,bool report,bool early=false)321 can_inline_edge_p (struct cgraph_edge *e, bool report,
322 bool early = false)
323 {
324 gcc_checking_assert (e->inline_failed);
325
326 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
327 {
328 if (report)
329 report_inline_failed_reason (e);
330 return false;
331 }
332
333 bool inlinable = true;
334 enum availability avail;
335 cgraph_node *caller = (e->caller->inlined_to
336 ? e->caller->inlined_to : e->caller);
337 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
338
339 if (!callee->definition)
340 {
341 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
342 inlinable = false;
343 }
344 if (!early && (!opt_for_fn (callee->decl, optimize)
345 || !opt_for_fn (caller->decl, optimize)))
346 {
347 e->inline_failed = CIF_FUNCTION_NOT_OPTIMIZED;
348 inlinable = false;
349 }
350 else if (callee->calls_comdat_local)
351 {
352 e->inline_failed = CIF_USES_COMDAT_LOCAL;
353 inlinable = false;
354 }
355 else if (avail <= AVAIL_INTERPOSABLE)
356 {
357 e->inline_failed = CIF_OVERWRITABLE;
358 inlinable = false;
359 }
360 /* All edges with call_stmt_cannot_inline_p should have inline_failed
361 initialized to one of FINAL_ERROR reasons. */
362 else if (e->call_stmt_cannot_inline_p)
363 gcc_unreachable ();
364 /* Don't inline if the functions have different EH personalities. */
365 else if (DECL_FUNCTION_PERSONALITY (caller->decl)
366 && DECL_FUNCTION_PERSONALITY (callee->decl)
367 && (DECL_FUNCTION_PERSONALITY (caller->decl)
368 != DECL_FUNCTION_PERSONALITY (callee->decl)))
369 {
370 e->inline_failed = CIF_EH_PERSONALITY;
371 inlinable = false;
372 }
373 /* TM pure functions should not be inlined into non-TM_pure
374 functions. */
375 else if (is_tm_pure (callee->decl) && !is_tm_pure (caller->decl))
376 {
377 e->inline_failed = CIF_UNSPECIFIED;
378 inlinable = false;
379 }
380 /* Check compatibility of target optimization options. */
381 else if (!targetm.target_option.can_inline_p (caller->decl,
382 callee->decl))
383 {
384 e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
385 inlinable = false;
386 }
387 else if (ipa_fn_summaries->get (callee) == NULL
388 || !ipa_fn_summaries->get (callee)->inlinable)
389 {
390 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
391 inlinable = false;
392 }
393 /* Don't inline a function with mismatched sanitization attributes. */
394 else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
395 {
396 e->inline_failed = CIF_SANITIZE_ATTRIBUTE_MISMATCH;
397 inlinable = false;
398 }
399
400 if (!inlinable && report)
401 report_inline_failed_reason (e);
402 return inlinable;
403 }
404
405 /* Return inlining_insns_single limit for function N. If HINT or HINT2 is true
406 scale up the bound. */
407
408 static int
inline_insns_single(cgraph_node * n,bool hint,bool hint2)409 inline_insns_single (cgraph_node *n, bool hint, bool hint2)
410 {
411 if (hint && hint2)
412 {
413 int64_t spd = opt_for_fn (n->decl, param_inline_heuristics_hint_percent);
414 spd = spd * spd;
415 if (spd > 1000000)
416 spd = 1000000;
417 return opt_for_fn (n->decl, param_max_inline_insns_single) * spd / 100;
418 }
419 if (hint || hint2)
420 return opt_for_fn (n->decl, param_max_inline_insns_single)
421 * opt_for_fn (n->decl, param_inline_heuristics_hint_percent) / 100;
422 return opt_for_fn (n->decl, param_max_inline_insns_single);
423 }
424
425 /* Return inlining_insns_auto limit for function N. If HINT or HINT2 is true
426 scale up the bound. */
427
428 static int
inline_insns_auto(cgraph_node * n,bool hint,bool hint2)429 inline_insns_auto (cgraph_node *n, bool hint, bool hint2)
430 {
431 int max_inline_insns_auto = opt_for_fn (n->decl, param_max_inline_insns_auto);
432 if (hint && hint2)
433 {
434 int64_t spd = opt_for_fn (n->decl, param_inline_heuristics_hint_percent);
435 spd = spd * spd;
436 if (spd > 1000000)
437 spd = 1000000;
438 return max_inline_insns_auto * spd / 100;
439 }
440 if (hint || hint2)
441 return max_inline_insns_auto
442 * opt_for_fn (n->decl, param_inline_heuristics_hint_percent) / 100;
443 return max_inline_insns_auto;
444 }
445
446 /* Decide if we can inline the edge and possibly update
447 inline_failed reason.
448 We check whether inlining is possible at all and whether
449 caller growth limits allow doing so.
450
451 if REPORT is true, output reason to the dump file.
452
453 if DISREGARD_LIMITS is true, ignore size limits. */
454
455 static bool
can_inline_edge_by_limits_p(struct cgraph_edge * e,bool report,bool disregard_limits=false,bool early=false)456 can_inline_edge_by_limits_p (struct cgraph_edge *e, bool report,
457 bool disregard_limits = false, bool early = false)
458 {
459 gcc_checking_assert (e->inline_failed);
460
461 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
462 {
463 if (report)
464 report_inline_failed_reason (e);
465 return false;
466 }
467
468 bool inlinable = true;
469 enum availability avail;
470 cgraph_node *caller = (e->caller->inlined_to
471 ? e->caller->inlined_to : e->caller);
472 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
473 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl);
474 tree callee_tree
475 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL;
476 /* Check if caller growth allows the inlining. */
477 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
478 && !disregard_limits
479 && !lookup_attribute ("flatten",
480 DECL_ATTRIBUTES (caller->decl))
481 && !caller_growth_limits (e))
482 inlinable = false;
483 else if (callee->externally_visible
484 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl)
485 && flag_live_patching == LIVE_PATCHING_INLINE_ONLY_STATIC)
486 {
487 e->inline_failed = CIF_EXTERN_LIVE_ONLY_STATIC;
488 inlinable = false;
489 }
490 /* Don't inline a function with a higher optimization level than the
491 caller. FIXME: this is really just tip of iceberg of handling
492 optimization attribute. */
493 else if (caller_tree != callee_tree)
494 {
495 bool always_inline =
496 (DECL_DISREGARD_INLINE_LIMITS (callee->decl)
497 && lookup_attribute ("always_inline",
498 DECL_ATTRIBUTES (callee->decl)));
499 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
500 ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
501
502 /* Until GCC 4.9 we did not check the semantics-altering flags
503 below and inlined across optimization boundaries.
504 Enabling checks below breaks several packages by refusing
505 to inline library always_inline functions. See PR65873.
506 Disable the check for early inlining for now until better solution
507 is found. */
508 if (always_inline && early)
509 ;
510 /* There are some options that change IL semantics which means
511 we cannot inline in these cases for correctness reason.
512 Not even for always_inline declared functions. */
513 else if (check_match (flag_wrapv)
514 || check_match (flag_trapv)
515 || check_match (flag_pcc_struct_return)
516 || check_maybe_down (optimize_debug)
517 /* When caller or callee does FP math, be sure FP codegen flags
518 compatible. */
519 || ((caller_info->fp_expressions && callee_info->fp_expressions)
520 && (check_maybe_up (flag_rounding_math)
521 || check_maybe_up (flag_trapping_math)
522 || check_maybe_down (flag_unsafe_math_optimizations)
523 || check_maybe_down (flag_finite_math_only)
524 || check_maybe_up (flag_signaling_nans)
525 || check_maybe_down (flag_cx_limited_range)
526 || check_maybe_up (flag_signed_zeros)
527 || check_maybe_down (flag_associative_math)
528 || check_maybe_down (flag_reciprocal_math)
529 || check_maybe_down (flag_fp_int_builtin_inexact)
530 /* Strictly speaking only when the callee contains function
531 calls that may end up setting errno. */
532 || check_maybe_up (flag_errno_math)))
533 /* We do not want to make code compiled with exceptions to be
534 brought into a non-EH function unless we know that the callee
535 does not throw.
536 This is tracked by DECL_FUNCTION_PERSONALITY. */
537 || (check_maybe_up (flag_non_call_exceptions)
538 && DECL_FUNCTION_PERSONALITY (callee->decl))
539 || (check_maybe_up (flag_exceptions)
540 && DECL_FUNCTION_PERSONALITY (callee->decl))
541 /* When devirtualization is disabled for callee, it is not safe
542 to inline it as we possibly mangled the type info.
543 Allow early inlining of always inlines. */
544 || (!early && check_maybe_down (flag_devirtualize)))
545 {
546 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
547 inlinable = false;
548 }
549 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
550 else if (always_inline)
551 ;
552 /* When user added an attribute to the callee honor it. */
553 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee->decl))
554 && opts_for_fn (caller->decl) != opts_for_fn (callee->decl))
555 {
556 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
557 inlinable = false;
558 }
559 /* If explicit optimize attribute are not used, the mismatch is caused
560 by different command line options used to build different units.
561 Do not care about COMDAT functions - those are intended to be
562 optimized with the optimization flags of module they are used in.
563 Also do not care about mixing up size/speed optimization when
564 DECL_DISREGARD_INLINE_LIMITS is set. */
565 else if ((callee->merged_comdat
566 && !lookup_attribute ("optimize",
567 DECL_ATTRIBUTES (caller->decl)))
568 || DECL_DISREGARD_INLINE_LIMITS (callee->decl))
569 ;
570 /* If mismatch is caused by merging two LTO units with different
571 optimization flags we want to be bit nicer. However never inline
572 if one of functions is not optimized at all. */
573 else if (!opt_for_fn (callee->decl, optimize)
574 || !opt_for_fn (caller->decl, optimize))
575 {
576 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
577 inlinable = false;
578 }
579 /* If callee is optimized for size and caller is not, allow inlining if
580 code shrinks or we are in param_max_inline_insns_single limit and
581 callee is inline (and thus likely an unified comdat).
582 This will allow caller to run faster. */
583 else if (opt_for_fn (callee->decl, optimize_size)
584 > opt_for_fn (caller->decl, optimize_size))
585 {
586 int growth = estimate_edge_growth (e);
587 if (growth > opt_for_fn (caller->decl, param_max_inline_insns_size)
588 && (!DECL_DECLARED_INLINE_P (callee->decl)
589 && growth >= MAX (inline_insns_single (caller, false, false),
590 inline_insns_auto (caller, false, false))))
591 {
592 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
593 inlinable = false;
594 }
595 }
596 /* If callee is more aggressively optimized for performance than caller,
597 we generally want to inline only cheap (runtime wise) functions. */
598 else if (opt_for_fn (callee->decl, optimize_size)
599 < opt_for_fn (caller->decl, optimize_size)
600 || (opt_for_fn (callee->decl, optimize)
601 > opt_for_fn (caller->decl, optimize)))
602 {
603 if (estimate_edge_time (e)
604 >= 20 + ipa_call_summaries->get (e)->call_stmt_time)
605 {
606 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
607 inlinable = false;
608 }
609 }
610
611 }
612
613 if (!inlinable && report)
614 report_inline_failed_reason (e);
615 return inlinable;
616 }
617
618
619 /* Return true if the edge E is inlinable during early inlining. */
620
621 static bool
can_early_inline_edge_p(struct cgraph_edge * e)622 can_early_inline_edge_p (struct cgraph_edge *e)
623 {
624 cgraph_node *caller = (e->caller->inlined_to
625 ? e->caller->inlined_to : e->caller);
626 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
627 /* Early inliner might get called at WPA stage when IPA pass adds new
628 function. In this case we cannot really do any of early inlining
629 because function bodies are missing. */
630 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
631 return false;
632 if (!gimple_has_body_p (callee->decl))
633 {
634 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
635 return false;
636 }
637 /* In early inliner some of callees may not be in SSA form yet
638 (i.e. the callgraph is cyclic and we did not process
639 the callee by early inliner, yet). We don't have CIF code for this
640 case; later we will re-do the decision in the real inliner. */
641 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
642 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
643 {
644 if (dump_enabled_p ())
645 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
646 " edge not inlinable: not in SSA form\n");
647 return false;
648 }
649 else if (profile_arc_flag
650 && ((lookup_attribute ("no_profile_instrument_function",
651 DECL_ATTRIBUTES (caller->decl)) == NULL_TREE)
652 != (lookup_attribute ("no_profile_instrument_function",
653 DECL_ATTRIBUTES (callee->decl)) == NULL_TREE)))
654 return false;
655
656 if (!can_inline_edge_p (e, true, true)
657 || !can_inline_edge_by_limits_p (e, true, false, true))
658 return false;
659 return true;
660 }
661
662
663 /* Return number of calls in N. Ignore cheap builtins. */
664
665 static int
num_calls(struct cgraph_node * n)666 num_calls (struct cgraph_node *n)
667 {
668 struct cgraph_edge *e;
669 int num = 0;
670
671 for (e = n->callees; e; e = e->next_callee)
672 if (!is_inexpensive_builtin (e->callee->decl))
673 num++;
674 return num;
675 }
676
677
678 /* Return true if we are interested in inlining small function. */
679
680 static bool
want_early_inline_function_p(struct cgraph_edge * e)681 want_early_inline_function_p (struct cgraph_edge *e)
682 {
683 bool want_inline = true;
684 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
685
686 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
687 ;
688 /* For AutoFDO, we need to make sure that before profile summary, all
689 hot paths' IR look exactly the same as profiled binary. As a result,
690 in einliner, we will disregard size limit and inline those callsites
691 that are:
692 * inlined in the profiled binary, and
693 * the cloned callee has enough samples to be considered "hot". */
694 else if (flag_auto_profile && afdo_callsite_hot_enough_for_early_inline (e))
695 ;
696 else if (!DECL_DECLARED_INLINE_P (callee->decl)
697 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
698 {
699 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
700 report_inline_failed_reason (e);
701 want_inline = false;
702 }
703 else
704 {
705 /* First take care of very large functions. */
706 int min_growth = estimate_min_edge_growth (e), growth = 0;
707 int n;
708 int early_inlining_insns = param_early_inlining_insns;
709
710 if (min_growth > early_inlining_insns)
711 {
712 if (dump_enabled_p ())
713 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
714 " will not early inline: %C->%C, "
715 "call is cold and code would grow "
716 "at least by %i\n",
717 e->caller, callee,
718 min_growth);
719 want_inline = false;
720 }
721 else
722 growth = estimate_edge_growth (e);
723
724
725 if (!want_inline || growth <= param_max_inline_insns_size)
726 ;
727 else if (!e->maybe_hot_p ())
728 {
729 if (dump_enabled_p ())
730 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
731 " will not early inline: %C->%C, "
732 "call is cold and code would grow by %i\n",
733 e->caller, callee,
734 growth);
735 want_inline = false;
736 }
737 else if (growth > early_inlining_insns)
738 {
739 if (dump_enabled_p ())
740 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
741 " will not early inline: %C->%C, "
742 "growth %i exceeds --param early-inlining-insns\n",
743 e->caller, callee, growth);
744 want_inline = false;
745 }
746 else if ((n = num_calls (callee)) != 0
747 && growth * (n + 1) > early_inlining_insns)
748 {
749 if (dump_enabled_p ())
750 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
751 " will not early inline: %C->%C, "
752 "growth %i exceeds --param early-inlining-insns "
753 "divided by number of calls\n",
754 e->caller, callee, growth);
755 want_inline = false;
756 }
757 }
758 return want_inline;
759 }
760
761 /* Compute time of the edge->caller + edge->callee execution when inlining
762 does not happen. */
763
764 inline sreal
compute_uninlined_call_time(struct cgraph_edge * edge,sreal uninlined_call_time,sreal freq)765 compute_uninlined_call_time (struct cgraph_edge *edge,
766 sreal uninlined_call_time,
767 sreal freq)
768 {
769 cgraph_node *caller = (edge->caller->inlined_to
770 ? edge->caller->inlined_to
771 : edge->caller);
772
773 if (freq > 0)
774 uninlined_call_time *= freq;
775 else
776 uninlined_call_time = uninlined_call_time >> 11;
777
778 sreal caller_time = ipa_fn_summaries->get (caller)->time;
779 return uninlined_call_time + caller_time;
780 }
781
782 /* Same as compute_uinlined_call_time but compute time when inlining
783 does happen. */
784
785 inline sreal
compute_inlined_call_time(struct cgraph_edge * edge,sreal time,sreal freq)786 compute_inlined_call_time (struct cgraph_edge *edge,
787 sreal time,
788 sreal freq)
789 {
790 cgraph_node *caller = (edge->caller->inlined_to
791 ? edge->caller->inlined_to
792 : edge->caller);
793 sreal caller_time = ipa_fn_summaries->get (caller)->time;
794
795 if (freq > 0)
796 time *= freq;
797 else
798 time = time >> 11;
799
800 /* This calculation should match one in ipa-inline-analysis.cc
801 (estimate_edge_size_and_time). */
802 time -= (sreal)ipa_call_summaries->get (edge)->call_stmt_time * freq;
803 time += caller_time;
804 if (time <= 0)
805 time = ((sreal) 1) >> 8;
806 gcc_checking_assert (time >= 0);
807 return time;
808 }
809
810 /* Determine time saved by inlining EDGE of frequency FREQ
811 where callee's runtime w/o inlining is UNINLINED_TYPE
812 and with inlined is INLINED_TYPE. */
813
814 inline sreal
inlining_speedup(struct cgraph_edge * edge,sreal freq,sreal uninlined_time,sreal inlined_time)815 inlining_speedup (struct cgraph_edge *edge,
816 sreal freq,
817 sreal uninlined_time,
818 sreal inlined_time)
819 {
820 sreal speedup = uninlined_time - inlined_time;
821 /* Handling of call_time should match one in ipa-inline-fnsummary.c
822 (estimate_edge_size_and_time). */
823 sreal call_time = ipa_call_summaries->get (edge)->call_stmt_time;
824
825 if (freq > 0)
826 {
827 speedup = (speedup + call_time);
828 if (freq != 1)
829 speedup = speedup * freq;
830 }
831 else if (freq == 0)
832 speedup = speedup >> 11;
833 gcc_checking_assert (speedup >= 0);
834 return speedup;
835 }
836
837 /* Return true if the speedup for inlining E is bigger than
838 param_inline_min_speedup. */
839
840 static bool
big_speedup_p(struct cgraph_edge * e)841 big_speedup_p (struct cgraph_edge *e)
842 {
843 sreal unspec_time;
844 sreal spec_time = estimate_edge_time (e, &unspec_time);
845 sreal freq = e->sreal_frequency ();
846 sreal time = compute_uninlined_call_time (e, unspec_time, freq);
847 sreal inlined_time = compute_inlined_call_time (e, spec_time, freq);
848 cgraph_node *caller = (e->caller->inlined_to
849 ? e->caller->inlined_to
850 : e->caller);
851 int limit = opt_for_fn (caller->decl, param_inline_min_speedup);
852
853 if ((time - inlined_time) * 100 > time * limit)
854 return true;
855 return false;
856 }
857
858 /* Return true if we are interested in inlining small function.
859 When REPORT is true, report reason to dump file. */
860
861 static bool
want_inline_small_function_p(struct cgraph_edge * e,bool report)862 want_inline_small_function_p (struct cgraph_edge *e, bool report)
863 {
864 bool want_inline = true;
865 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
866 cgraph_node *to = (e->caller->inlined_to
867 ? e->caller->inlined_to : e->caller);
868
869 /* Allow this function to be called before can_inline_edge_p,
870 since it's usually cheaper. */
871 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
872 want_inline = false;
873 else if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
874 ;
875 else if (!DECL_DECLARED_INLINE_P (callee->decl)
876 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
877 {
878 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
879 want_inline = false;
880 }
881 /* Do fast and conservative check if the function can be good
882 inline candidate. */
883 else if ((!DECL_DECLARED_INLINE_P (callee->decl)
884 && (!e->count.ipa ().initialized_p () || !e->maybe_hot_p ()))
885 && ipa_fn_summaries->get (callee)->min_size
886 - ipa_call_summaries->get (e)->call_stmt_size
887 > inline_insns_auto (e->caller, true, true))
888 {
889 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
890 want_inline = false;
891 }
892 else if ((DECL_DECLARED_INLINE_P (callee->decl)
893 || e->count.ipa ().nonzero_p ())
894 && ipa_fn_summaries->get (callee)->min_size
895 - ipa_call_summaries->get (e)->call_stmt_size
896 > inline_insns_single (e->caller, true, true))
897 {
898 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
899 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
900 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT);
901 want_inline = false;
902 }
903 else
904 {
905 int growth = estimate_edge_growth (e);
906 ipa_hints hints = estimate_edge_hints (e);
907 /* We have two independent groups of hints. If one matches in each
908 of groups the limits are inreased. If both groups matches, limit
909 is increased even more. */
910 bool apply_hints = (hints & (INLINE_HINT_indirect_call
911 | INLINE_HINT_known_hot
912 | INLINE_HINT_loop_iterations
913 | INLINE_HINT_loop_stride));
914 bool apply_hints2 = (hints & INLINE_HINT_builtin_constant_p);
915
916 if (growth <= opt_for_fn (to->decl,
917 param_max_inline_insns_size))
918 ;
919 /* Apply param_max_inline_insns_single limit. Do not do so when
920 hints suggests that inlining given function is very profitable.
921 Avoid computation of big_speedup_p when not necessary to change
922 outcome of decision. */
923 else if (DECL_DECLARED_INLINE_P (callee->decl)
924 && growth >= inline_insns_single (e->caller, apply_hints,
925 apply_hints2)
926 && (apply_hints || apply_hints2
927 || growth >= inline_insns_single (e->caller, true,
928 apply_hints2)
929 || !big_speedup_p (e)))
930 {
931 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
932 want_inline = false;
933 }
934 else if (!DECL_DECLARED_INLINE_P (callee->decl)
935 && !opt_for_fn (e->caller->decl, flag_inline_functions)
936 && growth >= opt_for_fn (to->decl,
937 param_max_inline_insns_small))
938 {
939 /* growth_positive_p is expensive, always test it last. */
940 if (growth >= inline_insns_single (e->caller, false, false)
941 || growth_positive_p (callee, e, growth))
942 {
943 e->inline_failed = CIF_NOT_DECLARED_INLINED;
944 want_inline = false;
945 }
946 }
947 /* Apply param_max_inline_insns_auto limit for functions not declared
948 inline. Bypass the limit when speedup seems big. */
949 else if (!DECL_DECLARED_INLINE_P (callee->decl)
950 && growth >= inline_insns_auto (e->caller, apply_hints,
951 apply_hints2)
952 && (apply_hints || apply_hints2
953 || growth >= inline_insns_auto (e->caller, true,
954 apply_hints2)
955 || !big_speedup_p (e)))
956 {
957 /* growth_positive_p is expensive, always test it last. */
958 if (growth >= inline_insns_single (e->caller, false, false)
959 || growth_positive_p (callee, e, growth))
960 {
961 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
962 want_inline = false;
963 }
964 }
965 /* If call is cold, do not inline when function body would grow. */
966 else if (!e->maybe_hot_p ()
967 && (growth >= inline_insns_single (e->caller, false, false)
968 || growth_positive_p (callee, e, growth)))
969 {
970 e->inline_failed = CIF_UNLIKELY_CALL;
971 want_inline = false;
972 }
973 }
974 if (!want_inline && report)
975 report_inline_failed_reason (e);
976 return want_inline;
977 }
978
979 /* EDGE is self recursive edge.
980 We handle two cases - when function A is inlining into itself
981 or when function A is being inlined into another inliner copy of function
982 A within function B.
983
984 In first case OUTER_NODE points to the toplevel copy of A, while
985 in the second case OUTER_NODE points to the outermost copy of A in B.
986
987 In both cases we want to be extra selective since
988 inlining the call will just introduce new recursive calls to appear. */
989
990 static bool
want_inline_self_recursive_call_p(struct cgraph_edge * edge,struct cgraph_node * outer_node,bool peeling,int depth)991 want_inline_self_recursive_call_p (struct cgraph_edge *edge,
992 struct cgraph_node *outer_node,
993 bool peeling,
994 int depth)
995 {
996 char const *reason = NULL;
997 bool want_inline = true;
998 sreal caller_freq = 1;
999 int max_depth = opt_for_fn (outer_node->decl,
1000 param_max_inline_recursive_depth_auto);
1001
1002 if (DECL_DECLARED_INLINE_P (edge->caller->decl))
1003 max_depth = opt_for_fn (outer_node->decl,
1004 param_max_inline_recursive_depth);
1005
1006 if (!edge->maybe_hot_p ())
1007 {
1008 reason = "recursive call is cold";
1009 want_inline = false;
1010 }
1011 else if (depth > max_depth)
1012 {
1013 reason = "--param max-inline-recursive-depth exceeded.";
1014 want_inline = false;
1015 }
1016 else if (outer_node->inlined_to
1017 && (caller_freq = outer_node->callers->sreal_frequency ()) == 0)
1018 {
1019 reason = "caller frequency is 0";
1020 want_inline = false;
1021 }
1022
1023 if (!want_inline)
1024 ;
1025 /* Inlining of self recursive function into copy of itself within other
1026 function is transformation similar to loop peeling.
1027
1028 Peeling is profitable if we can inline enough copies to make probability
1029 of actual call to the self recursive function very small. Be sure that
1030 the probability of recursion is small.
1031
1032 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
1033 This way the expected number of recursion is at most max_depth. */
1034 else if (peeling)
1035 {
1036 sreal max_prob = (sreal)1 - ((sreal)1 / (sreal)max_depth);
1037 int i;
1038 for (i = 1; i < depth; i++)
1039 max_prob = max_prob * max_prob;
1040 if (edge->sreal_frequency () >= max_prob * caller_freq)
1041 {
1042 reason = "frequency of recursive call is too large";
1043 want_inline = false;
1044 }
1045 }
1046 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if
1047 recursion depth is large. We reduce function call overhead and increase
1048 chances that things fit in hardware return predictor.
1049
1050 Recursive inlining might however increase cost of stack frame setup
1051 actually slowing down functions whose recursion tree is wide rather than
1052 deep.
1053
1054 Deciding reliably on when to do recursive inlining without profile feedback
1055 is tricky. For now we disable recursive inlining when probability of self
1056 recursion is low.
1057
1058 Recursive inlining of self recursive call within loop also results in
1059 large loop depths that generally optimize badly. We may want to throttle
1060 down inlining in those cases. In particular this seems to happen in one
1061 of libstdc++ rb tree methods. */
1062 else
1063 {
1064 if (edge->sreal_frequency () * 100
1065 <= caller_freq
1066 * opt_for_fn (outer_node->decl,
1067 param_min_inline_recursive_probability))
1068 {
1069 reason = "frequency of recursive call is too small";
1070 want_inline = false;
1071 }
1072 }
1073 if (!want_inline && dump_enabled_p ())
1074 dump_printf_loc (MSG_MISSED_OPTIMIZATION, edge->call_stmt,
1075 " not inlining recursively: %s\n", reason);
1076 return want_inline;
1077 }
1078
1079 /* Return true when NODE has uninlinable caller;
1080 set HAS_HOT_CALL if it has hot call.
1081 Worker for cgraph_for_node_and_aliases. */
1082
1083 static bool
check_callers(struct cgraph_node * node,void * has_hot_call)1084 check_callers (struct cgraph_node *node, void *has_hot_call)
1085 {
1086 struct cgraph_edge *e;
1087 for (e = node->callers; e; e = e->next_caller)
1088 {
1089 if (!opt_for_fn (e->caller->decl, flag_inline_functions_called_once)
1090 || !opt_for_fn (e->caller->decl, optimize))
1091 return true;
1092 if (!can_inline_edge_p (e, true))
1093 return true;
1094 if (e->recursive_p ())
1095 return true;
1096 if (!can_inline_edge_by_limits_p (e, true))
1097 return true;
1098 /* Inlining large functions to large loop depth is often harmful because
1099 of register pressure it implies. */
1100 if ((int)ipa_call_summaries->get (e)->loop_depth
1101 > param_inline_functions_called_once_loop_depth)
1102 return true;
1103 /* Do not produce gigantic functions. */
1104 if (estimate_size_after_inlining (e->caller->inlined_to ?
1105 e->caller->inlined_to : e->caller, e)
1106 > param_inline_functions_called_once_insns)
1107 return true;
1108 if (!(*(bool *)has_hot_call) && e->maybe_hot_p ())
1109 *(bool *)has_hot_call = true;
1110 }
1111 return false;
1112 }
1113
1114 /* If NODE has a caller, return true. */
1115
1116 static bool
has_caller_p(struct cgraph_node * node,void * data ATTRIBUTE_UNUSED)1117 has_caller_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
1118 {
1119 if (node->callers)
1120 return true;
1121 return false;
1122 }
1123
1124 /* Decide if inlining NODE would reduce unit size by eliminating
1125 the offline copy of function.
1126 When COLD is true the cold calls are considered, too. */
1127
1128 static bool
want_inline_function_to_all_callers_p(struct cgraph_node * node,bool cold)1129 want_inline_function_to_all_callers_p (struct cgraph_node *node, bool cold)
1130 {
1131 bool has_hot_call = false;
1132
1133 /* Aliases gets inlined along with the function they alias. */
1134 if (node->alias)
1135 return false;
1136 /* Already inlined? */
1137 if (node->inlined_to)
1138 return false;
1139 /* Does it have callers? */
1140 if (!node->call_for_symbol_and_aliases (has_caller_p, NULL, true))
1141 return false;
1142 /* Inlining into all callers would increase size? */
1143 if (growth_positive_p (node, NULL, INT_MIN) > 0)
1144 return false;
1145 /* All inlines must be possible. */
1146 if (node->call_for_symbol_and_aliases (check_callers, &has_hot_call,
1147 true))
1148 return false;
1149 if (!cold && !has_hot_call)
1150 return false;
1151 return true;
1152 }
1153
1154 /* Return true if WHERE of SIZE is a possible candidate for wrapper heuristics
1155 in estimate_edge_badness. */
1156
1157 static bool
wrapper_heuristics_may_apply(struct cgraph_node * where,int size)1158 wrapper_heuristics_may_apply (struct cgraph_node *where, int size)
1159 {
1160 return size < (DECL_DECLARED_INLINE_P (where->decl)
1161 ? inline_insns_single (where, false, false)
1162 : inline_insns_auto (where, false, false));
1163 }
1164
1165 /* A cost model driving the inlining heuristics in a way so the edges with
1166 smallest badness are inlined first. After each inlining is performed
1167 the costs of all caller edges of nodes affected are recomputed so the
1168 metrics may accurately depend on values such as number of inlinable callers
1169 of the function or function body size. */
1170
1171 static sreal
edge_badness(struct cgraph_edge * edge,bool dump)1172 edge_badness (struct cgraph_edge *edge, bool dump)
1173 {
1174 sreal badness;
1175 int growth;
1176 sreal edge_time, unspec_edge_time;
1177 struct cgraph_node *callee = edge->callee->ultimate_alias_target ();
1178 class ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
1179 ipa_hints hints;
1180 cgraph_node *caller = (edge->caller->inlined_to
1181 ? edge->caller->inlined_to
1182 : edge->caller);
1183
1184 growth = estimate_edge_growth (edge);
1185 edge_time = estimate_edge_time (edge, &unspec_edge_time);
1186 hints = estimate_edge_hints (edge);
1187 gcc_checking_assert (edge_time >= 0);
1188 /* Check that inlined time is better, but tolerate some roundoff issues.
1189 FIXME: When callee profile drops to 0 we account calls more. This
1190 should be fixed by never doing that. */
1191 gcc_checking_assert ((edge_time * 100
1192 - callee_info->time * 101).to_int () <= 0
1193 || callee->count.ipa ().initialized_p ());
1194 gcc_checking_assert (growth <= ipa_size_summaries->get (callee)->size);
1195
1196 if (dump)
1197 {
1198 fprintf (dump_file, " Badness calculation for %s -> %s\n",
1199 edge->caller->dump_name (),
1200 edge->callee->dump_name ());
1201 fprintf (dump_file, " size growth %i, time %f unspec %f ",
1202 growth,
1203 edge_time.to_double (),
1204 unspec_edge_time.to_double ());
1205 ipa_dump_hints (dump_file, hints);
1206 if (big_speedup_p (edge))
1207 fprintf (dump_file, " big_speedup");
1208 fprintf (dump_file, "\n");
1209 }
1210
1211 /* Always prefer inlining saving code size. */
1212 if (growth <= 0)
1213 {
1214 badness = (sreal) (-SREAL_MIN_SIG + growth) << (SREAL_MAX_EXP / 256);
1215 if (dump)
1216 fprintf (dump_file, " %f: Growth %d <= 0\n", badness.to_double (),
1217 growth);
1218 }
1219 /* Inlining into EXTERNAL functions is not going to change anything unless
1220 they are themselves inlined. */
1221 else if (DECL_EXTERNAL (caller->decl))
1222 {
1223 if (dump)
1224 fprintf (dump_file, " max: function is external\n");
1225 return sreal::max ();
1226 }
1227 /* When profile is available. Compute badness as:
1228
1229 time_saved * caller_count
1230 goodness = -------------------------------------------------
1231 growth_of_caller * overall_growth * combined_size
1232
1233 badness = - goodness
1234
1235 Again use negative value to make calls with profile appear hotter
1236 then calls without.
1237 */
1238 else if (opt_for_fn (caller->decl, flag_guess_branch_prob)
1239 || caller->count.ipa ().nonzero_p ())
1240 {
1241 sreal numerator, denominator;
1242 int overall_growth;
1243 sreal freq = edge->sreal_frequency ();
1244
1245 numerator = inlining_speedup (edge, freq, unspec_edge_time, edge_time);
1246 if (numerator <= 0)
1247 numerator = ((sreal) 1 >> 8);
1248 if (caller->count.ipa ().nonzero_p ())
1249 numerator *= caller->count.ipa ().to_gcov_type ();
1250 else if (caller->count.ipa ().initialized_p ())
1251 numerator = numerator >> 11;
1252 denominator = growth;
1253
1254 overall_growth = callee_info->growth;
1255
1256 /* Look for inliner wrappers of the form:
1257
1258 inline_caller ()
1259 {
1260 do_fast_job...
1261 if (need_more_work)
1262 noninline_callee ();
1263 }
1264 Without penalizing this case, we usually inline noninline_callee
1265 into the inline_caller because overall_growth is small preventing
1266 further inlining of inline_caller.
1267
1268 Penalize only callgraph edges to functions with small overall
1269 growth ...
1270 */
1271 if (growth > overall_growth
1272 /* ... and having only one caller which is not inlined ... */
1273 && callee_info->single_caller
1274 && !edge->caller->inlined_to
1275 /* ... and edges executed only conditionally ... */
1276 && freq < 1
1277 /* ... consider case where callee is not inline but caller is ... */
1278 && ((!DECL_DECLARED_INLINE_P (edge->callee->decl)
1279 && DECL_DECLARED_INLINE_P (caller->decl))
1280 /* ... or when early optimizers decided to split and edge
1281 frequency still indicates splitting is a win ... */
1282 || (callee->split_part && !caller->split_part
1283 && freq * 100
1284 < opt_for_fn (caller->decl,
1285 param_partial_inlining_entry_probability)
1286 /* ... and do not overwrite user specified hints. */
1287 && (!DECL_DECLARED_INLINE_P (edge->callee->decl)
1288 || DECL_DECLARED_INLINE_P (caller->decl)))))
1289 {
1290 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
1291 int caller_growth = caller_info->growth;
1292
1293 /* Only apply the penalty when caller looks like inline candidate,
1294 and it is not called once. */
1295 if (!caller_info->single_caller && overall_growth < caller_growth
1296 && caller_info->inlinable
1297 && wrapper_heuristics_may_apply
1298 (caller, ipa_size_summaries->get (caller)->size))
1299 {
1300 if (dump)
1301 fprintf (dump_file,
1302 " Wrapper penalty. Increasing growth %i to %i\n",
1303 overall_growth, caller_growth);
1304 overall_growth = caller_growth;
1305 }
1306 }
1307 if (overall_growth > 0)
1308 {
1309 /* Strongly prefer functions with few callers that can be inlined
1310 fully. The square root here leads to smaller binaries at average.
1311 Watch however for extreme cases and return to linear function
1312 when growth is large. */
1313 if (overall_growth < 256)
1314 overall_growth *= overall_growth;
1315 else
1316 overall_growth += 256 * 256 - 256;
1317 denominator *= overall_growth;
1318 }
1319 denominator *= ipa_size_summaries->get (caller)->size + growth;
1320
1321 badness = - numerator / denominator;
1322
1323 if (dump)
1324 {
1325 fprintf (dump_file,
1326 " %f: guessed profile. frequency %f, count %" PRId64
1327 " caller count %" PRId64
1328 " time saved %f"
1329 " overall growth %i (current) %i (original)"
1330 " %i (compensated)\n",
1331 badness.to_double (),
1332 freq.to_double (),
1333 edge->count.ipa ().initialized_p ()
1334 ? edge->count.ipa ().to_gcov_type () : -1,
1335 caller->count.ipa ().initialized_p ()
1336 ? caller->count.ipa ().to_gcov_type () : -1,
1337 inlining_speedup (edge, freq, unspec_edge_time,
1338 edge_time).to_double (),
1339 estimate_growth (callee),
1340 callee_info->growth, overall_growth);
1341 }
1342 }
1343 /* When function local profile is not available or it does not give
1344 useful information (i.e. frequency is zero), base the cost on
1345 loop nest and overall size growth, so we optimize for overall number
1346 of functions fully inlined in program. */
1347 else
1348 {
1349 int nest = MIN (ipa_call_summaries->get (edge)->loop_depth, 8);
1350 badness = growth;
1351
1352 /* Decrease badness if call is nested. */
1353 if (badness > 0)
1354 badness = badness >> nest;
1355 else
1356 badness = badness << nest;
1357 if (dump)
1358 fprintf (dump_file, " %f: no profile. nest %i\n",
1359 badness.to_double (), nest);
1360 }
1361 gcc_checking_assert (badness != 0);
1362
1363 if (edge->recursive_p ())
1364 badness = badness.shift (badness > 0 ? 4 : -4);
1365 if ((hints & (INLINE_HINT_indirect_call
1366 | INLINE_HINT_loop_iterations
1367 | INLINE_HINT_loop_stride))
1368 || callee_info->growth <= 0)
1369 badness = badness.shift (badness > 0 ? -2 : 2);
1370 if (hints & INLINE_HINT_builtin_constant_p)
1371 badness = badness.shift (badness > 0 ? -4 : 4);
1372 if (hints & (INLINE_HINT_same_scc))
1373 badness = badness.shift (badness > 0 ? 3 : -3);
1374 else if (hints & (INLINE_HINT_in_scc))
1375 badness = badness.shift (badness > 0 ? 2 : -2);
1376 else if (hints & (INLINE_HINT_cross_module))
1377 badness = badness.shift (badness > 0 ? 1 : -1);
1378 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
1379 badness = badness.shift (badness > 0 ? -4 : 4);
1380 else if ((hints & INLINE_HINT_declared_inline))
1381 badness = badness.shift (badness > 0 ? -3 : 3);
1382 if (dump)
1383 fprintf (dump_file, " Adjusted by hints %f\n", badness.to_double ());
1384 return badness;
1385 }
1386
1387 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1388 static inline void
update_edge_key(edge_heap_t * heap,struct cgraph_edge * edge)1389 update_edge_key (edge_heap_t *heap, struct cgraph_edge *edge)
1390 {
1391 sreal badness = edge_badness (edge, false);
1392 if (edge->aux)
1393 {
1394 edge_heap_node_t *n = (edge_heap_node_t *) edge->aux;
1395 gcc_checking_assert (n->get_data () == edge);
1396
1397 /* fibonacci_heap::replace_key does busy updating of the
1398 heap that is unnecessarily expensive.
1399 We do lazy increases: after extracting minimum if the key
1400 turns out to be out of date, it is re-inserted into heap
1401 with correct value. */
1402 if (badness < n->get_key ())
1403 {
1404 if (dump_file && (dump_flags & TDF_DETAILS))
1405 {
1406 fprintf (dump_file,
1407 " decreasing badness %s -> %s, %f to %f\n",
1408 edge->caller->dump_name (),
1409 edge->callee->dump_name (),
1410 n->get_key ().to_double (),
1411 badness.to_double ());
1412 }
1413 heap->decrease_key (n, badness);
1414 }
1415 }
1416 else
1417 {
1418 if (dump_file && (dump_flags & TDF_DETAILS))
1419 {
1420 fprintf (dump_file,
1421 " enqueuing call %s -> %s, badness %f\n",
1422 edge->caller->dump_name (),
1423 edge->callee->dump_name (),
1424 badness.to_double ());
1425 }
1426 edge->aux = heap->insert (badness, edge);
1427 }
1428 }
1429
1430
1431 /* NODE was inlined.
1432 All caller edges needs to be reset because
1433 size estimates change. Similarly callees needs reset
1434 because better context may be known. */
1435
1436 static void
reset_edge_caches(struct cgraph_node * node)1437 reset_edge_caches (struct cgraph_node *node)
1438 {
1439 struct cgraph_edge *edge;
1440 struct cgraph_edge *e = node->callees;
1441 struct cgraph_node *where = node;
1442 struct ipa_ref *ref;
1443
1444 if (where->inlined_to)
1445 where = where->inlined_to;
1446
1447 reset_node_cache (where);
1448
1449 if (edge_growth_cache != NULL)
1450 for (edge = where->callers; edge; edge = edge->next_caller)
1451 if (edge->inline_failed)
1452 edge_growth_cache->remove (edge);
1453
1454 FOR_EACH_ALIAS (where, ref)
1455 reset_edge_caches (dyn_cast <cgraph_node *> (ref->referring));
1456
1457 if (!e)
1458 return;
1459
1460 while (true)
1461 if (!e->inline_failed && e->callee->callees)
1462 e = e->callee->callees;
1463 else
1464 {
1465 if (edge_growth_cache != NULL && e->inline_failed)
1466 edge_growth_cache->remove (e);
1467 if (e->next_callee)
1468 e = e->next_callee;
1469 else
1470 {
1471 do
1472 {
1473 if (e->caller == node)
1474 return;
1475 e = e->caller->callers;
1476 }
1477 while (!e->next_callee);
1478 e = e->next_callee;
1479 }
1480 }
1481 }
1482
1483 /* Recompute HEAP nodes for each of caller of NODE.
1484 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1485 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1486 it is inlinable. Otherwise check all edges. */
1487
1488 static void
update_caller_keys(edge_heap_t * heap,struct cgraph_node * node,bitmap updated_nodes,struct cgraph_edge * check_inlinablity_for)1489 update_caller_keys (edge_heap_t *heap, struct cgraph_node *node,
1490 bitmap updated_nodes,
1491 struct cgraph_edge *check_inlinablity_for)
1492 {
1493 struct cgraph_edge *edge;
1494 struct ipa_ref *ref;
1495
1496 if ((!node->alias && !ipa_fn_summaries->get (node)->inlinable)
1497 || node->inlined_to)
1498 return;
1499 if (!bitmap_set_bit (updated_nodes, node->get_uid ()))
1500 return;
1501
1502 FOR_EACH_ALIAS (node, ref)
1503 {
1504 struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
1505 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for);
1506 }
1507
1508 for (edge = node->callers; edge; edge = edge->next_caller)
1509 if (edge->inline_failed)
1510 {
1511 if (!check_inlinablity_for
1512 || check_inlinablity_for == edge)
1513 {
1514 if (can_inline_edge_p (edge, false)
1515 && want_inline_small_function_p (edge, false)
1516 && can_inline_edge_by_limits_p (edge, false))
1517 update_edge_key (heap, edge);
1518 else if (edge->aux)
1519 {
1520 report_inline_failed_reason (edge);
1521 heap->delete_node ((edge_heap_node_t *) edge->aux);
1522 edge->aux = NULL;
1523 }
1524 }
1525 else if (edge->aux)
1526 update_edge_key (heap, edge);
1527 }
1528 }
1529
1530 /* Recompute HEAP nodes for each uninlined call in NODE
1531 If UPDATE_SINCE is non-NULL check if edges called within that function
1532 are inlinable (typically UPDATE_SINCE is the inline clone we introduced
1533 where all edges have new context).
1534
1535 This is used when we know that edge badnesses are going only to increase
1536 (we introduced new call site) and thus all we need is to insert newly
1537 created edges into heap. */
1538
1539 static void
update_callee_keys(edge_heap_t * heap,struct cgraph_node * node,struct cgraph_node * update_since,bitmap updated_nodes)1540 update_callee_keys (edge_heap_t *heap, struct cgraph_node *node,
1541 struct cgraph_node *update_since,
1542 bitmap updated_nodes)
1543 {
1544 struct cgraph_edge *e = node->callees;
1545 bool check_inlinability = update_since == node;
1546
1547 if (!e)
1548 return;
1549 while (true)
1550 if (!e->inline_failed && e->callee->callees)
1551 {
1552 if (e->callee == update_since)
1553 check_inlinability = true;
1554 e = e->callee->callees;
1555 }
1556 else
1557 {
1558 enum availability avail;
1559 struct cgraph_node *callee;
1560 if (!check_inlinability)
1561 {
1562 if (e->aux
1563 && !bitmap_bit_p (updated_nodes,
1564 e->callee->ultimate_alias_target
1565 (&avail, e->caller)->get_uid ()))
1566 update_edge_key (heap, e);
1567 }
1568 /* We do not reset callee growth cache here. Since we added a new call,
1569 growth should have just increased and consequently badness metric
1570 don't need updating. */
1571 else if (e->inline_failed
1572 && (callee = e->callee->ultimate_alias_target (&avail,
1573 e->caller))
1574 && avail >= AVAIL_AVAILABLE
1575 && ipa_fn_summaries->get (callee) != NULL
1576 && ipa_fn_summaries->get (callee)->inlinable
1577 && !bitmap_bit_p (updated_nodes, callee->get_uid ()))
1578 {
1579 if (can_inline_edge_p (e, false)
1580 && want_inline_small_function_p (e, false)
1581 && can_inline_edge_by_limits_p (e, false))
1582 {
1583 gcc_checking_assert (check_inlinability || can_inline_edge_p (e, false));
1584 gcc_checking_assert (check_inlinability || e->aux);
1585 update_edge_key (heap, e);
1586 }
1587 else if (e->aux)
1588 {
1589 report_inline_failed_reason (e);
1590 heap->delete_node ((edge_heap_node_t *) e->aux);
1591 e->aux = NULL;
1592 }
1593 }
1594 /* In case we redirected to unreachable node we only need to remove the
1595 fibheap entry. */
1596 else if (e->aux)
1597 {
1598 heap->delete_node ((edge_heap_node_t *) e->aux);
1599 e->aux = NULL;
1600 }
1601 if (e->next_callee)
1602 e = e->next_callee;
1603 else
1604 {
1605 do
1606 {
1607 if (e->caller == node)
1608 return;
1609 if (e->caller == update_since)
1610 check_inlinability = false;
1611 e = e->caller->callers;
1612 }
1613 while (!e->next_callee);
1614 e = e->next_callee;
1615 }
1616 }
1617 }
1618
1619 /* Enqueue all recursive calls from NODE into priority queue depending on
1620 how likely we want to recursively inline the call. */
1621
1622 static void
lookup_recursive_calls(struct cgraph_node * node,struct cgraph_node * where,edge_heap_t * heap)1623 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
1624 edge_heap_t *heap)
1625 {
1626 struct cgraph_edge *e;
1627 enum availability avail;
1628
1629 for (e = where->callees; e; e = e->next_callee)
1630 if (e->callee == node
1631 || (e->callee->ultimate_alias_target (&avail, e->caller) == node
1632 && avail > AVAIL_INTERPOSABLE))
1633 heap->insert (-e->sreal_frequency (), e);
1634 for (e = where->callees; e; e = e->next_callee)
1635 if (!e->inline_failed)
1636 lookup_recursive_calls (node, e->callee, heap);
1637 }
1638
1639 /* Decide on recursive inlining: in the case function has recursive calls,
1640 inline until body size reaches given argument. If any new indirect edges
1641 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1642 is NULL. */
1643
1644 static bool
recursive_inlining(struct cgraph_edge * edge,vec<cgraph_edge * > * new_edges)1645 recursive_inlining (struct cgraph_edge *edge,
1646 vec<cgraph_edge *> *new_edges)
1647 {
1648 cgraph_node *to = (edge->caller->inlined_to
1649 ? edge->caller->inlined_to : edge->caller);
1650 int limit = opt_for_fn (to->decl,
1651 param_max_inline_insns_recursive_auto);
1652 edge_heap_t heap (sreal::min ());
1653 struct cgraph_node *node;
1654 struct cgraph_edge *e;
1655 struct cgraph_node *master_clone = NULL, *next;
1656 int depth = 0;
1657 int n = 0;
1658
1659 node = edge->caller;
1660 if (node->inlined_to)
1661 node = node->inlined_to;
1662
1663 if (DECL_DECLARED_INLINE_P (node->decl))
1664 limit = opt_for_fn (to->decl, param_max_inline_insns_recursive);
1665
1666 /* Make sure that function is small enough to be considered for inlining. */
1667 if (estimate_size_after_inlining (node, edge) >= limit)
1668 return false;
1669 lookup_recursive_calls (node, node, &heap);
1670 if (heap.empty ())
1671 return false;
1672
1673 if (dump_file)
1674 fprintf (dump_file,
1675 " Performing recursive inlining on %s\n", node->dump_name ());
1676
1677 /* Do the inlining and update list of recursive call during process. */
1678 while (!heap.empty ())
1679 {
1680 struct cgraph_edge *curr = heap.extract_min ();
1681 struct cgraph_node *cnode, *dest = curr->callee;
1682
1683 if (!can_inline_edge_p (curr, true)
1684 || !can_inline_edge_by_limits_p (curr, true))
1685 continue;
1686
1687 /* MASTER_CLONE is produced in the case we already started modified
1688 the function. Be sure to redirect edge to the original body before
1689 estimating growths otherwise we will be seeing growths after inlining
1690 the already modified body. */
1691 if (master_clone)
1692 {
1693 curr->redirect_callee (master_clone);
1694 if (edge_growth_cache != NULL)
1695 edge_growth_cache->remove (curr);
1696 }
1697
1698 if (estimate_size_after_inlining (node, curr) > limit)
1699 {
1700 curr->redirect_callee (dest);
1701 if (edge_growth_cache != NULL)
1702 edge_growth_cache->remove (curr);
1703 break;
1704 }
1705
1706 depth = 1;
1707 for (cnode = curr->caller;
1708 cnode->inlined_to; cnode = cnode->callers->caller)
1709 if (node->decl
1710 == curr->callee->ultimate_alias_target ()->decl)
1711 depth++;
1712
1713 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1714 {
1715 curr->redirect_callee (dest);
1716 if (edge_growth_cache != NULL)
1717 edge_growth_cache->remove (curr);
1718 continue;
1719 }
1720
1721 if (dump_file)
1722 {
1723 fprintf (dump_file,
1724 " Inlining call of depth %i", depth);
1725 if (node->count.nonzero_p () && curr->count.initialized_p ())
1726 {
1727 fprintf (dump_file, " called approx. %.2f times per call",
1728 (double)curr->count.to_gcov_type ()
1729 / node->count.to_gcov_type ());
1730 }
1731 fprintf (dump_file, "\n");
1732 }
1733 if (!master_clone)
1734 {
1735 /* We need original clone to copy around. */
1736 master_clone = node->create_clone (node->decl, node->count,
1737 false, vNULL, true, NULL, NULL);
1738 for (e = master_clone->callees; e; e = e->next_callee)
1739 if (!e->inline_failed)
1740 clone_inlined_nodes (e, true, false, NULL);
1741 curr->redirect_callee (master_clone);
1742 if (edge_growth_cache != NULL)
1743 edge_growth_cache->remove (curr);
1744 }
1745
1746 inline_call (curr, false, new_edges, &overall_size, true);
1747 reset_node_cache (node);
1748 lookup_recursive_calls (node, curr->callee, &heap);
1749 n++;
1750 }
1751
1752 if (!heap.empty () && dump_file)
1753 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1754
1755 if (!master_clone)
1756 return false;
1757
1758 if (dump_enabled_p ())
1759 dump_printf_loc (MSG_NOTE, edge->call_stmt,
1760 "\n Inlined %i times, "
1761 "body grown from size %i to %i, time %f to %f\n", n,
1762 ipa_size_summaries->get (master_clone)->size,
1763 ipa_size_summaries->get (node)->size,
1764 ipa_fn_summaries->get (master_clone)->time.to_double (),
1765 ipa_fn_summaries->get (node)->time.to_double ());
1766
1767 /* Remove master clone we used for inlining. We rely that clones inlined
1768 into master clone gets queued just before master clone so we don't
1769 need recursion. */
1770 for (node = symtab->first_function (); node != master_clone;
1771 node = next)
1772 {
1773 next = symtab->next_function (node);
1774 if (node->inlined_to == master_clone)
1775 node->remove ();
1776 }
1777 master_clone->remove ();
1778 return true;
1779 }
1780
1781
1782 /* Given whole compilation unit estimate of INSNS, compute how large we can
1783 allow the unit to grow. */
1784
1785 static int64_t
compute_max_insns(cgraph_node * node,int insns)1786 compute_max_insns (cgraph_node *node, int insns)
1787 {
1788 int max_insns = insns;
1789 if (max_insns < opt_for_fn (node->decl, param_large_unit_insns))
1790 max_insns = opt_for_fn (node->decl, param_large_unit_insns);
1791
1792 return ((int64_t) max_insns
1793 * (100 + opt_for_fn (node->decl, param_inline_unit_growth)) / 100);
1794 }
1795
1796
1797 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1798
1799 static void
add_new_edges_to_heap(edge_heap_t * heap,vec<cgraph_edge * > & new_edges)1800 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> &new_edges)
1801 {
1802 while (new_edges.length () > 0)
1803 {
1804 struct cgraph_edge *edge = new_edges.pop ();
1805
1806 gcc_assert (!edge->aux);
1807 gcc_assert (edge->callee);
1808 if (edge->inline_failed
1809 && can_inline_edge_p (edge, true)
1810 && want_inline_small_function_p (edge, true)
1811 && can_inline_edge_by_limits_p (edge, true))
1812 edge->aux = heap->insert (edge_badness (edge, false), edge);
1813 }
1814 }
1815
1816 /* Remove EDGE from the fibheap. */
1817
1818 static void
heap_edge_removal_hook(struct cgraph_edge * e,void * data)1819 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1820 {
1821 if (e->aux)
1822 {
1823 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux);
1824 e->aux = NULL;
1825 }
1826 }
1827
1828 /* Return true if speculation of edge E seems useful.
1829 If ANTICIPATE_INLINING is true, be conservative and hope that E
1830 may get inlined. */
1831
1832 bool
speculation_useful_p(struct cgraph_edge * e,bool anticipate_inlining)1833 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1834 {
1835 /* If we have already decided to inline the edge, it seems useful. */
1836 if (!e->inline_failed)
1837 return true;
1838
1839 enum availability avail;
1840 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail,
1841 e->caller);
1842
1843 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1844
1845 if (!e->maybe_hot_p ())
1846 return false;
1847
1848 /* See if IP optimizations found something potentially useful about the
1849 function. For now we look only for CONST/PURE flags. Almost everything
1850 else we propagate is useless. */
1851 if (avail >= AVAIL_AVAILABLE)
1852 {
1853 int ecf_flags = flags_from_decl_or_type (target->decl);
1854 if (ecf_flags & ECF_CONST)
1855 {
1856 if (!(e->speculative_call_indirect_edge ()->indirect_info
1857 ->ecf_flags & ECF_CONST))
1858 return true;
1859 }
1860 else if (ecf_flags & ECF_PURE)
1861 {
1862 if (!(e->speculative_call_indirect_edge ()->indirect_info
1863 ->ecf_flags & ECF_PURE))
1864 return true;
1865 }
1866 }
1867 /* If we did not managed to inline the function nor redirect
1868 to an ipa-cp clone (that are seen by having local flag set),
1869 it is probably pointless to inline it unless hardware is missing
1870 indirect call predictor. */
1871 if (!anticipate_inlining && !target->local)
1872 return false;
1873 /* For overwritable targets there is not much to do. */
1874 if (!can_inline_edge_p (e, false)
1875 || !can_inline_edge_by_limits_p (e, false, true))
1876 return false;
1877 /* OK, speculation seems interesting. */
1878 return true;
1879 }
1880
1881 /* We know that EDGE is not going to be inlined.
1882 See if we can remove speculation. */
1883
1884 static void
resolve_noninline_speculation(edge_heap_t * edge_heap,struct cgraph_edge * edge)1885 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge)
1886 {
1887 if (edge->speculative && !speculation_useful_p (edge, false))
1888 {
1889 struct cgraph_node *node = edge->caller;
1890 struct cgraph_node *where = node->inlined_to
1891 ? node->inlined_to : node;
1892 auto_bitmap updated_nodes;
1893
1894 if (edge->count.ipa ().initialized_p ())
1895 spec_rem += edge->count.ipa ();
1896 cgraph_edge::resolve_speculation (edge);
1897 reset_edge_caches (where);
1898 ipa_update_overall_fn_summary (where);
1899 update_caller_keys (edge_heap, where,
1900 updated_nodes, NULL);
1901 update_callee_keys (edge_heap, where, NULL,
1902 updated_nodes);
1903 }
1904 }
1905
1906 /* Return true if NODE should be accounted for overall size estimate.
1907 Skip all nodes optimized for size so we can measure the growth of hot
1908 part of program no matter of the padding. */
1909
1910 bool
inline_account_function_p(struct cgraph_node * node)1911 inline_account_function_p (struct cgraph_node *node)
1912 {
1913 return (!DECL_EXTERNAL (node->decl)
1914 && !opt_for_fn (node->decl, optimize_size)
1915 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
1916 }
1917
1918 /* Count number of callers of NODE and store it into DATA (that
1919 points to int. Worker for cgraph_for_node_and_aliases. */
1920
1921 static bool
sum_callers(struct cgraph_node * node,void * data)1922 sum_callers (struct cgraph_node *node, void *data)
1923 {
1924 struct cgraph_edge *e;
1925 int *num_calls = (int *)data;
1926
1927 for (e = node->callers; e; e = e->next_caller)
1928 (*num_calls)++;
1929 return false;
1930 }
1931
1932 /* We only propagate across edges with non-interposable callee. */
1933
1934 inline bool
ignore_edge_p(struct cgraph_edge * e)1935 ignore_edge_p (struct cgraph_edge *e)
1936 {
1937 enum availability avail;
1938 e->callee->function_or_virtual_thunk_symbol (&avail, e->caller);
1939 return (avail <= AVAIL_INTERPOSABLE);
1940 }
1941
1942 /* We use greedy algorithm for inlining of small functions:
1943 All inline candidates are put into prioritized heap ordered in
1944 increasing badness.
1945
1946 The inlining of small functions is bounded by unit growth parameters. */
1947
1948 static void
inline_small_functions(void)1949 inline_small_functions (void)
1950 {
1951 struct cgraph_node *node;
1952 struct cgraph_edge *edge;
1953 edge_heap_t edge_heap (sreal::min ());
1954 auto_bitmap updated_nodes;
1955 int min_size;
1956 auto_vec<cgraph_edge *> new_indirect_edges;
1957 int initial_size = 0;
1958 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count);
1959 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1960 new_indirect_edges.create (8);
1961
1962 edge_removal_hook_holder
1963 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap);
1964
1965 /* Compute overall unit size and other global parameters used by badness
1966 metrics. */
1967
1968 max_count = profile_count::uninitialized ();
1969 ipa_reduced_postorder (order, true, ignore_edge_p);
1970 free (order);
1971
1972 FOR_EACH_DEFINED_FUNCTION (node)
1973 if (!node->inlined_to)
1974 {
1975 if (!node->alias && node->analyzed
1976 && (node->has_gimple_body_p () || node->thunk)
1977 && opt_for_fn (node->decl, optimize))
1978 {
1979 class ipa_fn_summary *info = ipa_fn_summaries->get (node);
1980 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux;
1981
1982 /* Do not account external functions, they will be optimized out
1983 if not inlined. Also only count the non-cold portion of program. */
1984 if (inline_account_function_p (node))
1985 initial_size += ipa_size_summaries->get (node)->size;
1986 info->growth = estimate_growth (node);
1987
1988 int num_calls = 0;
1989 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
1990 true);
1991 if (num_calls == 1)
1992 info->single_caller = true;
1993 if (dfs && dfs->next_cycle)
1994 {
1995 struct cgraph_node *n2;
1996 int id = dfs->scc_no + 1;
1997 for (n2 = node; n2;
1998 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle)
1999 if (opt_for_fn (n2->decl, optimize))
2000 {
2001 ipa_fn_summary *info2 = ipa_fn_summaries->get
2002 (n2->inlined_to ? n2->inlined_to : n2);
2003 if (info2->scc_no)
2004 break;
2005 info2->scc_no = id;
2006 }
2007 }
2008 }
2009
2010 for (edge = node->callers; edge; edge = edge->next_caller)
2011 max_count = max_count.max (edge->count.ipa ());
2012 }
2013 ipa_free_postorder_info ();
2014 initialize_growth_caches ();
2015
2016 if (dump_file)
2017 fprintf (dump_file,
2018 "\nDeciding on inlining of small functions. Starting with size %i.\n",
2019 initial_size);
2020
2021 overall_size = initial_size;
2022 min_size = overall_size;
2023
2024 /* Populate the heap with all edges we might inline. */
2025
2026 FOR_EACH_DEFINED_FUNCTION (node)
2027 {
2028 bool update = false;
2029 struct cgraph_edge *next = NULL;
2030 bool has_speculative = false;
2031
2032 if (!opt_for_fn (node->decl, optimize)
2033 /* With -Og we do not want to perform IPA inlining of small
2034 functions since there are no scalar cleanups after it
2035 that would realize the anticipated win. All abstraction
2036 is removed during early inlining. */
2037 || opt_for_fn (node->decl, optimize_debug))
2038 continue;
2039
2040 if (dump_file)
2041 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ());
2042
2043 for (edge = node->callees; edge; edge = edge->next_callee)
2044 {
2045 if (edge->inline_failed
2046 && !edge->aux
2047 && can_inline_edge_p (edge, true)
2048 && want_inline_small_function_p (edge, true)
2049 && can_inline_edge_by_limits_p (edge, true)
2050 && edge->inline_failed)
2051 {
2052 gcc_assert (!edge->aux);
2053 update_edge_key (&edge_heap, edge);
2054 }
2055 if (edge->speculative)
2056 has_speculative = true;
2057 }
2058 if (has_speculative)
2059 for (edge = node->callees; edge; edge = next)
2060 {
2061 next = edge->next_callee;
2062 if (edge->speculative
2063 && !speculation_useful_p (edge, edge->aux != NULL))
2064 {
2065 cgraph_edge::resolve_speculation (edge);
2066 update = true;
2067 }
2068 }
2069 if (update)
2070 {
2071 struct cgraph_node *where = node->inlined_to
2072 ? node->inlined_to : node;
2073 ipa_update_overall_fn_summary (where);
2074 reset_edge_caches (where);
2075 update_caller_keys (&edge_heap, where,
2076 updated_nodes, NULL);
2077 update_callee_keys (&edge_heap, where, NULL,
2078 updated_nodes);
2079 bitmap_clear (updated_nodes);
2080 }
2081 }
2082
2083 gcc_assert (in_lto_p
2084 || !(max_count > 0)
2085 || (profile_info && flag_branch_probabilities));
2086
2087 while (!edge_heap.empty ())
2088 {
2089 int old_size = overall_size;
2090 struct cgraph_node *where, *callee;
2091 sreal badness = edge_heap.min_key ();
2092 sreal current_badness;
2093 int growth;
2094
2095 edge = edge_heap.extract_min ();
2096 gcc_assert (edge->aux);
2097 edge->aux = NULL;
2098 if (!edge->inline_failed || !edge->callee->analyzed)
2099 continue;
2100
2101 /* Be sure that caches are maintained consistent.
2102 This check is affected by scaling roundoff errors when compiling for
2103 IPA this we skip it in that case. */
2104 if (flag_checking && !edge->callee->count.ipa_p ()
2105 && (!max_count.initialized_p () || !max_count.nonzero_p ()))
2106 {
2107 sreal cached_badness = edge_badness (edge, false);
2108
2109 int old_size_est = estimate_edge_size (edge);
2110 sreal old_time_est = estimate_edge_time (edge);
2111 int old_hints_est = estimate_edge_hints (edge);
2112
2113 if (edge_growth_cache != NULL)
2114 edge_growth_cache->remove (edge);
2115 reset_node_cache (edge->caller->inlined_to
2116 ? edge->caller->inlined_to
2117 : edge->caller);
2118 gcc_assert (old_size_est == estimate_edge_size (edge));
2119 gcc_assert (old_time_est == estimate_edge_time (edge));
2120 /* FIXME:
2121
2122 gcc_assert (old_hints_est == estimate_edge_hints (edge));
2123
2124 fails with profile feedback because some hints depends on
2125 maybe_hot_edge_p predicate and because callee gets inlined to other
2126 calls, the edge may become cold.
2127 This ought to be fixed by computing relative probabilities
2128 for given invocation but that will be better done once whole
2129 code is converted to sreals. Disable for now and revert to "wrong"
2130 value so enable/disable checking paths agree. */
2131 edge_growth_cache->get (edge)->hints = old_hints_est + 1;
2132
2133 /* When updating the edge costs, we only decrease badness in the keys.
2134 Increases of badness are handled lazily; when we see key with out
2135 of date value on it, we re-insert it now. */
2136 current_badness = edge_badness (edge, false);
2137 gcc_assert (cached_badness == current_badness);
2138 gcc_assert (current_badness >= badness);
2139 }
2140 else
2141 current_badness = edge_badness (edge, false);
2142 if (current_badness != badness)
2143 {
2144 if (edge_heap.min () && current_badness > edge_heap.min_key ())
2145 {
2146 edge->aux = edge_heap.insert (current_badness, edge);
2147 continue;
2148 }
2149 else
2150 badness = current_badness;
2151 }
2152
2153 if (!can_inline_edge_p (edge, true)
2154 || !can_inline_edge_by_limits_p (edge, true))
2155 {
2156 resolve_noninline_speculation (&edge_heap, edge);
2157 continue;
2158 }
2159
2160 callee = edge->callee->ultimate_alias_target ();
2161 growth = estimate_edge_growth (edge);
2162 if (dump_file)
2163 {
2164 fprintf (dump_file,
2165 "\nConsidering %s with %i size\n",
2166 callee->dump_name (),
2167 ipa_size_summaries->get (callee)->size);
2168 fprintf (dump_file,
2169 " to be inlined into %s in %s:%i\n"
2170 " Estimated badness is %f, frequency %.2f.\n",
2171 edge->caller->dump_name (),
2172 edge->call_stmt
2173 && (LOCATION_LOCUS (gimple_location ((const gimple *)
2174 edge->call_stmt))
2175 > BUILTINS_LOCATION)
2176 ? gimple_filename ((const gimple *) edge->call_stmt)
2177 : "unknown",
2178 edge->call_stmt
2179 ? gimple_lineno ((const gimple *) edge->call_stmt)
2180 : -1,
2181 badness.to_double (),
2182 edge->sreal_frequency ().to_double ());
2183 if (edge->count.ipa ().initialized_p ())
2184 {
2185 fprintf (dump_file, " Called ");
2186 edge->count.ipa ().dump (dump_file);
2187 fprintf (dump_file, " times\n");
2188 }
2189 if (dump_flags & TDF_DETAILS)
2190 edge_badness (edge, true);
2191 }
2192
2193 where = edge->caller;
2194
2195 if (overall_size + growth > compute_max_insns (where, min_size)
2196 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2197 {
2198 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
2199 report_inline_failed_reason (edge);
2200 resolve_noninline_speculation (&edge_heap, edge);
2201 continue;
2202 }
2203
2204 if (!want_inline_small_function_p (edge, true))
2205 {
2206 resolve_noninline_speculation (&edge_heap, edge);
2207 continue;
2208 }
2209
2210 profile_count old_count = callee->count;
2211
2212 /* Heuristics for inlining small functions work poorly for
2213 recursive calls where we do effects similar to loop unrolling.
2214 When inlining such edge seems profitable, leave decision on
2215 specific inliner. */
2216 if (edge->recursive_p ())
2217 {
2218 if (where->inlined_to)
2219 where = where->inlined_to;
2220 if (!recursive_inlining (edge,
2221 opt_for_fn (edge->caller->decl,
2222 flag_indirect_inlining)
2223 ? &new_indirect_edges : NULL))
2224 {
2225 edge->inline_failed = CIF_RECURSIVE_INLINING;
2226 resolve_noninline_speculation (&edge_heap, edge);
2227 continue;
2228 }
2229 reset_edge_caches (where);
2230 /* Recursive inliner inlines all recursive calls of the function
2231 at once. Consequently we need to update all callee keys. */
2232 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining))
2233 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2234 update_callee_keys (&edge_heap, where, where, updated_nodes);
2235 bitmap_clear (updated_nodes);
2236 }
2237 else
2238 {
2239 struct cgraph_node *outer_node = NULL;
2240 int depth = 0;
2241
2242 /* Consider the case where self recursive function A is inlined
2243 into B. This is desired optimization in some cases, since it
2244 leads to effect similar of loop peeling and we might completely
2245 optimize out the recursive call. However we must be extra
2246 selective. */
2247
2248 where = edge->caller;
2249 while (where->inlined_to)
2250 {
2251 if (where->decl == callee->decl)
2252 outer_node = where, depth++;
2253 where = where->callers->caller;
2254 }
2255 if (outer_node
2256 && !want_inline_self_recursive_call_p (edge, outer_node,
2257 true, depth))
2258 {
2259 edge->inline_failed
2260 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl)
2261 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
2262 resolve_noninline_speculation (&edge_heap, edge);
2263 continue;
2264 }
2265 else if (depth && dump_file)
2266 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
2267
2268 gcc_checking_assert (!callee->inlined_to);
2269
2270 int old_size = ipa_size_summaries->get (where)->size;
2271 sreal old_time = ipa_fn_summaries->get (where)->time;
2272
2273 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
2274 reset_edge_caches (edge->callee);
2275 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2276
2277 /* If caller's size and time increased we do not need to update
2278 all edges because badness is not going to decrease. */
2279 if (old_size <= ipa_size_summaries->get (where)->size
2280 && old_time <= ipa_fn_summaries->get (where)->time
2281 /* Wrapper penalty may be non-monotonous in this respect.
2282 Fortunately it only affects small functions. */
2283 && !wrapper_heuristics_may_apply (where, old_size))
2284 update_callee_keys (&edge_heap, edge->callee, edge->callee,
2285 updated_nodes);
2286 else
2287 update_callee_keys (&edge_heap, where,
2288 edge->callee,
2289 updated_nodes);
2290 }
2291 where = edge->caller;
2292 if (where->inlined_to)
2293 where = where->inlined_to;
2294
2295 /* Our profitability metric can depend on local properties
2296 such as number of inlinable calls and size of the function body.
2297 After inlining these properties might change for the function we
2298 inlined into (since it's body size changed) and for the functions
2299 called by function we inlined (since number of it inlinable callers
2300 might change). */
2301 update_caller_keys (&edge_heap, where, updated_nodes, NULL);
2302 /* Offline copy count has possibly changed, recompute if profile is
2303 available. */
2304 struct cgraph_node *n
2305 = cgraph_node::get (edge->callee->decl)->ultimate_alias_target ();
2306 if (n != edge->callee && n->analyzed && !(n->count == old_count)
2307 && n->count.ipa_p ())
2308 update_callee_keys (&edge_heap, n, NULL, updated_nodes);
2309 bitmap_clear (updated_nodes);
2310
2311 if (dump_enabled_p ())
2312 {
2313 ipa_fn_summary *s = ipa_fn_summaries->get (where);
2314
2315 /* dump_printf can't handle %+i. */
2316 char buf_net_change[100];
2317 snprintf (buf_net_change, sizeof buf_net_change, "%+i",
2318 overall_size - old_size);
2319
2320 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt,
2321 " Inlined %C into %C which now has time %f and "
2322 "size %i, net change of %s%s.\n",
2323 edge->callee, edge->caller,
2324 s->time.to_double (),
2325 ipa_size_summaries->get (edge->caller)->size,
2326 buf_net_change,
2327 cross_module_call_p (edge) ? " (cross module)":"");
2328 }
2329 if (min_size > overall_size)
2330 {
2331 min_size = overall_size;
2332
2333 if (dump_file)
2334 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
2335 }
2336 }
2337
2338 free_growth_caches ();
2339 if (dump_enabled_p ())
2340 dump_printf (MSG_NOTE,
2341 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2342 initial_size, overall_size,
2343 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
2344 symtab->remove_edge_removal_hook (edge_removal_hook_holder);
2345 }
2346
2347 /* Flatten NODE. Performed both during early inlining and
2348 at IPA inlining time. */
2349
2350 static void
flatten_function(struct cgraph_node * node,bool early,bool update)2351 flatten_function (struct cgraph_node *node, bool early, bool update)
2352 {
2353 struct cgraph_edge *e;
2354
2355 /* We shouldn't be called recursively when we are being processed. */
2356 gcc_assert (node->aux == NULL);
2357
2358 node->aux = (void *) node;
2359
2360 for (e = node->callees; e; e = e->next_callee)
2361 {
2362 struct cgraph_node *orig_callee;
2363 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2364
2365 /* We've hit cycle? It is time to give up. */
2366 if (callee->aux)
2367 {
2368 if (dump_enabled_p ())
2369 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2370 "Not inlining %C into %C to avoid cycle.\n",
2371 callee, e->caller);
2372 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR)
2373 e->inline_failed = CIF_RECURSIVE_INLINING;
2374 continue;
2375 }
2376
2377 /* When the edge is already inlined, we just need to recurse into
2378 it in order to fully flatten the leaves. */
2379 if (!e->inline_failed)
2380 {
2381 flatten_function (callee, early, false);
2382 continue;
2383 }
2384
2385 /* Flatten attribute needs to be processed during late inlining. For
2386 extra code quality we however do flattening during early optimization,
2387 too. */
2388 if (!early
2389 ? !can_inline_edge_p (e, true)
2390 && !can_inline_edge_by_limits_p (e, true)
2391 : !can_early_inline_edge_p (e))
2392 continue;
2393
2394 if (e->recursive_p ())
2395 {
2396 if (dump_enabled_p ())
2397 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2398 "Not inlining: recursive call.\n");
2399 continue;
2400 }
2401
2402 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
2403 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
2404 {
2405 if (dump_enabled_p ())
2406 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2407 "Not inlining: SSA form does not match.\n");
2408 continue;
2409 }
2410
2411 /* Inline the edge and flatten the inline clone. Avoid
2412 recursing through the original node if the node was cloned. */
2413 if (dump_enabled_p ())
2414 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2415 " Inlining %C into %C.\n",
2416 callee, e->caller);
2417 orig_callee = callee;
2418 inline_call (e, true, NULL, NULL, false);
2419 if (e->callee != orig_callee)
2420 orig_callee->aux = (void *) node;
2421 flatten_function (e->callee, early, false);
2422 if (e->callee != orig_callee)
2423 orig_callee->aux = NULL;
2424 }
2425
2426 node->aux = NULL;
2427 cgraph_node *where = node->inlined_to ? node->inlined_to : node;
2428 if (update && opt_for_fn (where->decl, optimize))
2429 ipa_update_overall_fn_summary (where);
2430 }
2431
2432 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2433 DATA points to number of calls originally found so we avoid infinite
2434 recursion. */
2435
2436 static bool
inline_to_all_callers_1(struct cgraph_node * node,void * data,hash_set<cgraph_node * > * callers)2437 inline_to_all_callers_1 (struct cgraph_node *node, void *data,
2438 hash_set<cgraph_node *> *callers)
2439 {
2440 int *num_calls = (int *)data;
2441 bool callee_removed = false;
2442
2443 while (node->callers && !node->inlined_to)
2444 {
2445 struct cgraph_node *caller = node->callers->caller;
2446
2447 if (!can_inline_edge_p (node->callers, true)
2448 || !can_inline_edge_by_limits_p (node->callers, true)
2449 || node->callers->recursive_p ())
2450 {
2451 if (dump_file)
2452 fprintf (dump_file, "Uninlinable call found; giving up.\n");
2453 *num_calls = 0;
2454 return false;
2455 }
2456
2457 if (dump_file)
2458 {
2459 cgraph_node *ultimate = node->ultimate_alias_target ();
2460 fprintf (dump_file,
2461 "\nInlining %s size %i.\n",
2462 ultimate->dump_name (),
2463 ipa_size_summaries->get (ultimate)->size);
2464 fprintf (dump_file,
2465 " Called once from %s %i insns.\n",
2466 node->callers->caller->dump_name (),
2467 ipa_size_summaries->get (node->callers->caller)->size);
2468 }
2469
2470 /* Remember which callers we inlined to, delaying updating the
2471 overall summary. */
2472 callers->add (node->callers->caller);
2473 inline_call (node->callers, true, NULL, NULL, false, &callee_removed);
2474 if (dump_file)
2475 fprintf (dump_file,
2476 " Inlined into %s which now has %i size\n",
2477 caller->dump_name (),
2478 ipa_size_summaries->get (caller)->size);
2479 if (!(*num_calls)--)
2480 {
2481 if (dump_file)
2482 fprintf (dump_file, "New calls found; giving up.\n");
2483 return callee_removed;
2484 }
2485 if (callee_removed)
2486 return true;
2487 }
2488 return false;
2489 }
2490
2491 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2492 update. */
2493
2494 static bool
inline_to_all_callers(struct cgraph_node * node,void * data)2495 inline_to_all_callers (struct cgraph_node *node, void *data)
2496 {
2497 hash_set<cgraph_node *> callers;
2498 bool res = inline_to_all_callers_1 (node, data, &callers);
2499 /* Perform the delayed update of the overall summary of all callers
2500 processed. This avoids quadratic behavior in the cases where
2501 we have a lot of calls to the same function. */
2502 for (hash_set<cgraph_node *>::iterator i = callers.begin ();
2503 i != callers.end (); ++i)
2504 ipa_update_overall_fn_summary ((*i)->inlined_to ? (*i)->inlined_to : *i);
2505 return res;
2506 }
2507
2508 /* Output overall time estimate. */
2509 static void
dump_overall_stats(void)2510 dump_overall_stats (void)
2511 {
2512 sreal sum_weighted = 0, sum = 0;
2513 struct cgraph_node *node;
2514
2515 FOR_EACH_DEFINED_FUNCTION (node)
2516 if (!node->inlined_to
2517 && !node->alias)
2518 {
2519 ipa_fn_summary *s = ipa_fn_summaries->get (node);
2520 if (s != NULL)
2521 {
2522 sum += s->time;
2523 if (node->count.ipa ().initialized_p ())
2524 sum_weighted += s->time * node->count.ipa ().to_gcov_type ();
2525 }
2526 }
2527 fprintf (dump_file, "Overall time estimate: "
2528 "%f weighted by profile: "
2529 "%f\n", sum.to_double (), sum_weighted.to_double ());
2530 }
2531
2532 /* Output some useful stats about inlining. */
2533
2534 static void
dump_inline_stats(void)2535 dump_inline_stats (void)
2536 {
2537 int64_t inlined_cnt = 0, inlined_indir_cnt = 0;
2538 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0;
2539 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0;
2540 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0;
2541 int64_t inlined_speculative = 0, inlined_speculative_ply = 0;
2542 int64_t indirect_poly_cnt = 0, indirect_cnt = 0;
2543 int64_t reason[CIF_N_REASONS][2];
2544 sreal reason_freq[CIF_N_REASONS];
2545 int i;
2546 struct cgraph_node *node;
2547
2548 memset (reason, 0, sizeof (reason));
2549 for (i=0; i < CIF_N_REASONS; i++)
2550 reason_freq[i] = 0;
2551 FOR_EACH_DEFINED_FUNCTION (node)
2552 {
2553 struct cgraph_edge *e;
2554 for (e = node->callees; e; e = e->next_callee)
2555 {
2556 if (e->inline_failed)
2557 {
2558 if (e->count.ipa ().initialized_p ())
2559 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type ();
2560 reason_freq[(int) e->inline_failed] += e->sreal_frequency ();
2561 reason[(int) e->inline_failed][1] ++;
2562 if (DECL_VIRTUAL_P (e->callee->decl)
2563 && e->count.ipa ().initialized_p ())
2564 {
2565 if (e->indirect_inlining_edge)
2566 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2567 else
2568 noninlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2569 }
2570 else if (e->count.ipa ().initialized_p ())
2571 {
2572 if (e->indirect_inlining_edge)
2573 noninlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2574 else
2575 noninlined_cnt += e->count.ipa ().to_gcov_type ();
2576 }
2577 }
2578 else if (e->count.ipa ().initialized_p ())
2579 {
2580 if (e->speculative)
2581 {
2582 if (DECL_VIRTUAL_P (e->callee->decl))
2583 inlined_speculative_ply += e->count.ipa ().to_gcov_type ();
2584 else
2585 inlined_speculative += e->count.ipa ().to_gcov_type ();
2586 }
2587 else if (DECL_VIRTUAL_P (e->callee->decl))
2588 {
2589 if (e->indirect_inlining_edge)
2590 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2591 else
2592 inlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2593 }
2594 else
2595 {
2596 if (e->indirect_inlining_edge)
2597 inlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2598 else
2599 inlined_cnt += e->count.ipa ().to_gcov_type ();
2600 }
2601 }
2602 }
2603 for (e = node->indirect_calls; e; e = e->next_callee)
2604 if (e->indirect_info->polymorphic
2605 & e->count.ipa ().initialized_p ())
2606 indirect_poly_cnt += e->count.ipa ().to_gcov_type ();
2607 else if (e->count.ipa ().initialized_p ())
2608 indirect_cnt += e->count.ipa ().to_gcov_type ();
2609 }
2610 if (max_count.initialized_p ())
2611 {
2612 fprintf (dump_file,
2613 "Inlined %" PRId64 " + speculative "
2614 "%" PRId64 " + speculative polymorphic "
2615 "%" PRId64 " + previously indirect "
2616 "%" PRId64 " + virtual "
2617 "%" PRId64 " + virtual and previously indirect "
2618 "%" PRId64 "\n" "Not inlined "
2619 "%" PRId64 " + previously indirect "
2620 "%" PRId64 " + virtual "
2621 "%" PRId64 " + virtual and previously indirect "
2622 "%" PRId64 " + still indirect "
2623 "%" PRId64 " + still indirect polymorphic "
2624 "%" PRId64 "\n", inlined_cnt,
2625 inlined_speculative, inlined_speculative_ply,
2626 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt,
2627 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt,
2628 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt);
2629 fprintf (dump_file, "Removed speculations ");
2630 spec_rem.dump (dump_file);
2631 fprintf (dump_file, "\n");
2632 }
2633 dump_overall_stats ();
2634 fprintf (dump_file, "\nWhy inlining failed?\n");
2635 for (i = 0; i < CIF_N_REASONS; i++)
2636 if (reason[i][1])
2637 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n",
2638 cgraph_inline_failed_string ((cgraph_inline_failed_t) i),
2639 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]);
2640 }
2641
2642 /* Called when node is removed. */
2643
2644 static void
flatten_remove_node_hook(struct cgraph_node * node,void * data)2645 flatten_remove_node_hook (struct cgraph_node *node, void *data)
2646 {
2647 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL)
2648 return;
2649
2650 hash_set<struct cgraph_node *> *removed
2651 = (hash_set<struct cgraph_node *> *) data;
2652 removed->add (node);
2653 }
2654
2655 /* Decide on the inlining. We do so in the topological order to avoid
2656 expenses on updating data structures. */
2657
2658 static unsigned int
ipa_inline(void)2659 ipa_inline (void)
2660 {
2661 struct cgraph_node *node;
2662 int nnodes;
2663 struct cgraph_node **order;
2664 int i, j;
2665 int cold;
2666 bool remove_functions = false;
2667
2668 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
2669
2670 if (dump_file)
2671 ipa_dump_fn_summaries (dump_file);
2672
2673 nnodes = ipa_reverse_postorder (order);
2674 spec_rem = profile_count::zero ();
2675
2676 FOR_EACH_FUNCTION (node)
2677 {
2678 node->aux = 0;
2679
2680 /* Recompute the default reasons for inlining because they may have
2681 changed during merging. */
2682 if (in_lto_p)
2683 {
2684 for (cgraph_edge *e = node->callees; e; e = e->next_callee)
2685 {
2686 gcc_assert (e->inline_failed);
2687 initialize_inline_failed (e);
2688 }
2689 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
2690 initialize_inline_failed (e);
2691 }
2692 }
2693
2694 if (dump_file)
2695 fprintf (dump_file, "\nFlattening functions:\n");
2696
2697 /* First shrink order array, so that it only contains nodes with
2698 flatten attribute. */
2699 for (i = nnodes - 1, j = i; i >= 0; i--)
2700 {
2701 node = order[i];
2702 if (node->definition
2703 /* Do not try to flatten aliases. These may happen for example when
2704 creating local aliases. */
2705 && !node->alias
2706 && lookup_attribute ("flatten",
2707 DECL_ATTRIBUTES (node->decl)) != NULL)
2708 order[j--] = order[i];
2709 }
2710
2711 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain
2712 nodes with flatten attribute. If there is more than one such
2713 node, we need to register a node removal hook, as flatten_function
2714 could remove other nodes with flatten attribute. See PR82801. */
2715 struct cgraph_node_hook_list *node_removal_hook_holder = NULL;
2716 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL;
2717 /*
2718 * XXXMRG: added "nnodes > 1" as -O2 (but not -O) warn:
2719 * "assuming signed overflow does not occur"
2720 */
2721 if (nnodes > 1 && j < nnodes - 2)
2722 {
2723 flatten_removed_nodes = new hash_set<struct cgraph_node *>;
2724 node_removal_hook_holder
2725 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook,
2726 flatten_removed_nodes);
2727 }
2728
2729 /* In the first pass handle functions to be flattened. Do this with
2730 a priority so none of our later choices will make this impossible. */
2731 for (i = nnodes - 1; i > j; i--)
2732 {
2733 node = order[i];
2734 if (flatten_removed_nodes
2735 && flatten_removed_nodes->contains (node))
2736 continue;
2737
2738 /* Handle nodes to be flattened.
2739 Ideally when processing callees we stop inlining at the
2740 entry of cycles, possibly cloning that entry point and
2741 try to flatten itself turning it into a self-recursive
2742 function. */
2743 if (dump_file)
2744 fprintf (dump_file, "Flattening %s\n", node->dump_name ());
2745 flatten_function (node, false, true);
2746 }
2747
2748 if (j < nnodes - 2)
2749 {
2750 symtab->remove_cgraph_removal_hook (node_removal_hook_holder);
2751 delete flatten_removed_nodes;
2752 }
2753 free (order);
2754
2755 if (dump_file)
2756 dump_overall_stats ();
2757
2758 inline_small_functions ();
2759
2760 gcc_assert (symtab->state == IPA_SSA);
2761 symtab->state = IPA_SSA_AFTER_INLINING;
2762 /* Do first after-inlining removal. We want to remove all "stale" extern
2763 inline functions and virtual functions so we really know what is called
2764 once. */
2765 symtab->remove_unreachable_nodes (dump_file);
2766
2767 /* Inline functions with a property that after inlining into all callers the
2768 code size will shrink because the out-of-line copy is eliminated.
2769 We do this regardless on the callee size as long as function growth limits
2770 are met. */
2771 if (dump_file)
2772 fprintf (dump_file,
2773 "\nDeciding on functions to be inlined into all callers and "
2774 "removing useless speculations:\n");
2775
2776 /* Inlining one function called once has good chance of preventing
2777 inlining other function into the same callee. Ideally we should
2778 work in priority order, but probably inlining hot functions first
2779 is good cut without the extra pain of maintaining the queue.
2780
2781 ??? this is not really fitting the bill perfectly: inlining function
2782 into callee often leads to better optimization of callee due to
2783 increased context for optimization.
2784 For example if main() function calls a function that outputs help
2785 and then function that does the main optimization, we should inline
2786 the second with priority even if both calls are cold by themselves.
2787
2788 We probably want to implement new predicate replacing our use of
2789 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2790 to be hot. */
2791 for (cold = 0; cold <= 1; cold ++)
2792 {
2793 FOR_EACH_DEFINED_FUNCTION (node)
2794 {
2795 struct cgraph_edge *edge, *next;
2796 bool update=false;
2797
2798 if (!opt_for_fn (node->decl, optimize)
2799 || !opt_for_fn (node->decl, flag_inline_functions_called_once))
2800 continue;
2801
2802 for (edge = node->callees; edge; edge = next)
2803 {
2804 next = edge->next_callee;
2805 if (edge->speculative && !speculation_useful_p (edge, false))
2806 {
2807 if (edge->count.ipa ().initialized_p ())
2808 spec_rem += edge->count.ipa ();
2809 cgraph_edge::resolve_speculation (edge);
2810 update = true;
2811 remove_functions = true;
2812 }
2813 }
2814 if (update)
2815 {
2816 struct cgraph_node *where = node->inlined_to
2817 ? node->inlined_to : node;
2818 reset_edge_caches (where);
2819 ipa_update_overall_fn_summary (where);
2820 }
2821 if (want_inline_function_to_all_callers_p (node, cold))
2822 {
2823 int num_calls = 0;
2824 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
2825 true);
2826 while (node->call_for_symbol_and_aliases
2827 (inline_to_all_callers, &num_calls, true))
2828 ;
2829 remove_functions = true;
2830 }
2831 }
2832 }
2833
2834 if (dump_enabled_p ())
2835 dump_printf (MSG_NOTE,
2836 "\nInlined %i calls, eliminated %i functions\n\n",
2837 ncalls_inlined, nfunctions_inlined);
2838 if (dump_file)
2839 dump_inline_stats ();
2840
2841 if (dump_file)
2842 ipa_dump_fn_summaries (dump_file);
2843 return remove_functions ? TODO_remove_functions : 0;
2844 }
2845
2846 /* Inline always-inline function calls in NODE. */
2847
2848 static bool
inline_always_inline_functions(struct cgraph_node * node)2849 inline_always_inline_functions (struct cgraph_node *node)
2850 {
2851 struct cgraph_edge *e;
2852 bool inlined = false;
2853
2854 for (e = node->callees; e; e = e->next_callee)
2855 {
2856 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2857 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2858 continue;
2859
2860 if (e->recursive_p ())
2861 {
2862 if (dump_enabled_p ())
2863 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2864 " Not inlining recursive call to %C.\n",
2865 e->callee);
2866 e->inline_failed = CIF_RECURSIVE_INLINING;
2867 continue;
2868 }
2869
2870 if (!can_early_inline_edge_p (e))
2871 {
2872 /* Set inlined to true if the callee is marked "always_inline" but
2873 is not inlinable. This will allow flagging an error later in
2874 expand_call_inline in tree-inline.cc. */
2875 if (lookup_attribute ("always_inline",
2876 DECL_ATTRIBUTES (callee->decl)) != NULL)
2877 inlined = true;
2878 continue;
2879 }
2880
2881 if (dump_enabled_p ())
2882 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2883 " Inlining %C into %C (always_inline).\n",
2884 e->callee, e->caller);
2885 inline_call (e, true, NULL, NULL, false);
2886 inlined = true;
2887 }
2888 if (inlined)
2889 ipa_update_overall_fn_summary (node);
2890
2891 return inlined;
2892 }
2893
2894 /* Decide on the inlining. We do so in the topological order to avoid
2895 expenses on updating data structures. */
2896
2897 static bool
early_inline_small_functions(struct cgraph_node * node)2898 early_inline_small_functions (struct cgraph_node *node)
2899 {
2900 struct cgraph_edge *e;
2901 bool inlined = false;
2902
2903 for (e = node->callees; e; e = e->next_callee)
2904 {
2905 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2906
2907 /* We can encounter not-yet-analyzed function during
2908 early inlining on callgraphs with strongly
2909 connected components. */
2910 ipa_fn_summary *s = ipa_fn_summaries->get (callee);
2911 if (s == NULL || !s->inlinable || !e->inline_failed)
2912 continue;
2913
2914 /* Do not consider functions not declared inline. */
2915 if (!DECL_DECLARED_INLINE_P (callee->decl)
2916 && !opt_for_fn (node->decl, flag_inline_small_functions)
2917 && !opt_for_fn (node->decl, flag_inline_functions))
2918 continue;
2919
2920 if (dump_enabled_p ())
2921 dump_printf_loc (MSG_NOTE, e->call_stmt,
2922 "Considering inline candidate %C.\n",
2923 callee);
2924
2925 if (!can_early_inline_edge_p (e))
2926 continue;
2927
2928 if (e->recursive_p ())
2929 {
2930 if (dump_enabled_p ())
2931 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2932 " Not inlining: recursive call.\n");
2933 continue;
2934 }
2935
2936 if (!want_early_inline_function_p (e))
2937 continue;
2938
2939 if (dump_enabled_p ())
2940 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2941 " Inlining %C into %C.\n",
2942 callee, e->caller);
2943 inline_call (e, true, NULL, NULL, false);
2944 inlined = true;
2945 }
2946
2947 if (inlined)
2948 ipa_update_overall_fn_summary (node);
2949
2950 return inlined;
2951 }
2952
2953 unsigned int
early_inliner(function * fun)2954 early_inliner (function *fun)
2955 {
2956 struct cgraph_node *node = cgraph_node::get (current_function_decl);
2957 struct cgraph_edge *edge;
2958 unsigned int todo = 0;
2959 int iterations = 0;
2960 bool inlined = false;
2961
2962 if (seen_error ())
2963 return 0;
2964
2965 /* Do nothing if datastructures for ipa-inliner are already computed. This
2966 happens when some pass decides to construct new function and
2967 cgraph_add_new_function calls lowering passes and early optimization on
2968 it. This may confuse ourself when early inliner decide to inline call to
2969 function clone, because function clones don't have parameter list in
2970 ipa-prop matching their signature. */
2971 if (ipa_node_params_sum)
2972 return 0;
2973
2974 if (flag_checking)
2975 node->verify ();
2976 node->remove_all_references ();
2977
2978 /* Even when not optimizing or not inlining inline always-inline
2979 functions. */
2980 inlined = inline_always_inline_functions (node);
2981
2982 if (!optimize
2983 || flag_no_inline
2984 || !flag_early_inlining
2985 /* Never inline regular functions into always-inline functions
2986 during incremental inlining. This sucks as functions calling
2987 always inline functions will get less optimized, but at the
2988 same time inlining of functions calling always inline
2989 function into an always inline function might introduce
2990 cycles of edges to be always inlined in the callgraph.
2991
2992 We might want to be smarter and just avoid this type of inlining. */
2993 || (DECL_DISREGARD_INLINE_LIMITS (node->decl)
2994 && lookup_attribute ("always_inline",
2995 DECL_ATTRIBUTES (node->decl))))
2996 ;
2997 else if (lookup_attribute ("flatten",
2998 DECL_ATTRIBUTES (node->decl)) != NULL)
2999 {
3000 /* When the function is marked to be flattened, recursively inline
3001 all calls in it. */
3002 if (dump_enabled_p ())
3003 dump_printf (MSG_OPTIMIZED_LOCATIONS,
3004 "Flattening %C\n", node);
3005 flatten_function (node, true, true);
3006 inlined = true;
3007 }
3008 else
3009 {
3010 /* If some always_inline functions was inlined, apply the changes.
3011 This way we will not account always inline into growth limits and
3012 moreover we will inline calls from always inlines that we skipped
3013 previously because of conditional above. */
3014 if (inlined)
3015 {
3016 timevar_push (TV_INTEGRATION);
3017 todo |= optimize_inline_calls (current_function_decl);
3018 /* optimize_inline_calls call above might have introduced new
3019 statements that don't have inline parameters computed. */
3020 for (edge = node->callees; edge; edge = edge->next_callee)
3021 {
3022 /* We can enounter not-yet-analyzed function during
3023 early inlining on callgraphs with strongly
3024 connected components. */
3025 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
3026 es->call_stmt_size
3027 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
3028 es->call_stmt_time
3029 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
3030 }
3031 ipa_update_overall_fn_summary (node);
3032 inlined = false;
3033 timevar_pop (TV_INTEGRATION);
3034 }
3035 /* We iterate incremental inlining to get trivial cases of indirect
3036 inlining. */
3037 while (iterations < opt_for_fn (node->decl,
3038 param_early_inliner_max_iterations)
3039 && early_inline_small_functions (node))
3040 {
3041 timevar_push (TV_INTEGRATION);
3042 todo |= optimize_inline_calls (current_function_decl);
3043
3044 /* Technically we ought to recompute inline parameters so the new
3045 iteration of early inliner works as expected. We however have
3046 values approximately right and thus we only need to update edge
3047 info that might be cleared out for newly discovered edges. */
3048 for (edge = node->callees; edge; edge = edge->next_callee)
3049 {
3050 /* We have no summary for new bound store calls yet. */
3051 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
3052 es->call_stmt_size
3053 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
3054 es->call_stmt_time
3055 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
3056 }
3057 if (iterations < opt_for_fn (node->decl,
3058 param_early_inliner_max_iterations) - 1)
3059 ipa_update_overall_fn_summary (node);
3060 timevar_pop (TV_INTEGRATION);
3061 iterations++;
3062 inlined = false;
3063 }
3064 if (dump_file)
3065 fprintf (dump_file, "Iterations: %i\n", iterations);
3066 }
3067
3068 if (inlined)
3069 {
3070 timevar_push (TV_INTEGRATION);
3071 todo |= optimize_inline_calls (current_function_decl);
3072 timevar_pop (TV_INTEGRATION);
3073 }
3074
3075 fun->always_inline_functions_inlined = true;
3076
3077 return todo;
3078 }
3079
3080 /* Do inlining of small functions. Doing so early helps profiling and other
3081 passes to be somewhat more effective and avoids some code duplication in
3082 later real inlining pass for testcases with very many function calls. */
3083
3084 namespace {
3085
3086 const pass_data pass_data_early_inline =
3087 {
3088 GIMPLE_PASS, /* type */
3089 "einline", /* name */
3090 OPTGROUP_INLINE, /* optinfo_flags */
3091 TV_EARLY_INLINING, /* tv_id */
3092 PROP_ssa, /* properties_required */
3093 0, /* properties_provided */
3094 0, /* properties_destroyed */
3095 0, /* todo_flags_start */
3096 0, /* todo_flags_finish */
3097 };
3098
3099 class pass_early_inline : public gimple_opt_pass
3100 {
3101 public:
pass_early_inline(gcc::context * ctxt)3102 pass_early_inline (gcc::context *ctxt)
3103 : gimple_opt_pass (pass_data_early_inline, ctxt)
3104 {}
3105
3106 /* opt_pass methods: */
3107 virtual unsigned int execute (function *);
3108
3109 }; // class pass_early_inline
3110
3111 unsigned int
execute(function * fun)3112 pass_early_inline::execute (function *fun)
3113 {
3114 return early_inliner (fun);
3115 }
3116
3117 } // anon namespace
3118
3119 gimple_opt_pass *
make_pass_early_inline(gcc::context * ctxt)3120 make_pass_early_inline (gcc::context *ctxt)
3121 {
3122 return new pass_early_inline (ctxt);
3123 }
3124
3125 namespace {
3126
3127 const pass_data pass_data_ipa_inline =
3128 {
3129 IPA_PASS, /* type */
3130 "inline", /* name */
3131 OPTGROUP_INLINE, /* optinfo_flags */
3132 TV_IPA_INLINING, /* tv_id */
3133 0, /* properties_required */
3134 0, /* properties_provided */
3135 0, /* properties_destroyed */
3136 0, /* todo_flags_start */
3137 ( TODO_dump_symtab ), /* todo_flags_finish */
3138 };
3139
3140 class pass_ipa_inline : public ipa_opt_pass_d
3141 {
3142 public:
pass_ipa_inline(gcc::context * ctxt)3143 pass_ipa_inline (gcc::context *ctxt)
3144 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt,
3145 NULL, /* generate_summary */
3146 NULL, /* write_summary */
3147 NULL, /* read_summary */
3148 NULL, /* write_optimization_summary */
3149 NULL, /* read_optimization_summary */
3150 NULL, /* stmt_fixup */
3151 0, /* function_transform_todo_flags_start */
3152 inline_transform, /* function_transform */
3153 NULL) /* variable_transform */
3154 {}
3155
3156 /* opt_pass methods: */
execute(function *)3157 virtual unsigned int execute (function *) { return ipa_inline (); }
3158
3159 }; // class pass_ipa_inline
3160
3161 } // anon namespace
3162
3163 ipa_opt_pass_d *
make_pass_ipa_inline(gcc::context * ctxt)3164 make_pass_ipa_inline (gcc::context *ctxt)
3165 {
3166 return new pass_ipa_inline (ctxt);
3167 }
3168