1 /* Inlining decision heuristics. 2 Copyright (C) 2003-2019 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 "params.h" 109 #include "profile.h" 110 #include "symbol-summary.h" 111 #include "tree-vrp.h" 112 #include "ipa-prop.h" 113 #include "ipa-fnsummary.h" 114 #include "ipa-inline.h" 115 #include "ipa-utils.h" 116 #include "sreal.h" 117 #include "auto-profile.h" 118 #include "builtins.h" 119 #include "fibonacci_heap.h" 120 #include "stringpool.h" 121 #include "attribs.h" 122 #include "asan.h" 123 124 typedef fibonacci_heap <sreal, cgraph_edge> edge_heap_t; 125 typedef fibonacci_node <sreal, cgraph_edge> edge_heap_node_t; 126 127 /* Statistics we collect about inlining algorithm. */ 128 static int overall_size; 129 static profile_count max_count; 130 static profile_count spec_rem; 131 132 /* Return false when inlining edge E would lead to violating 133 limits on function unit growth or stack usage growth. 134 135 The relative function body growth limit is present generally 136 to avoid problems with non-linear behavior of the compiler. 137 To allow inlining huge functions into tiny wrapper, the limit 138 is always based on the bigger of the two functions considered. 139 140 For stack growth limits we always base the growth in stack usage 141 of the callers. We want to prevent applications from segfaulting 142 on stack overflow when functions with huge stack frames gets 143 inlined. */ 144 145 static bool 146 caller_growth_limits (struct cgraph_edge *e) 147 { 148 struct cgraph_node *to = e->caller; 149 struct cgraph_node *what = e->callee->ultimate_alias_target (); 150 int newsize; 151 int limit = 0; 152 HOST_WIDE_INT stack_size_limit = 0, inlined_stack; 153 ipa_fn_summary *info, *what_info; 154 ipa_fn_summary *outer_info = ipa_fn_summaries->get (to); 155 156 /* Look for function e->caller is inlined to. While doing 157 so work out the largest function body on the way. As 158 described above, we want to base our function growth 159 limits based on that. Not on the self size of the 160 outer function, not on the self size of inline code 161 we immediately inline to. This is the most relaxed 162 interpretation of the rule "do not grow large functions 163 too much in order to prevent compiler from exploding". */ 164 while (true) 165 { 166 info = ipa_fn_summaries->get (to); 167 if (limit < info->self_size) 168 limit = info->self_size; 169 if (stack_size_limit < info->estimated_self_stack_size) 170 stack_size_limit = info->estimated_self_stack_size; 171 if (to->global.inlined_to) 172 to = to->callers->caller; 173 else 174 break; 175 } 176 177 what_info = ipa_fn_summaries->get (what); 178 179 if (limit < what_info->self_size) 180 limit = what_info->self_size; 181 182 limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100; 183 184 /* Check the size after inlining against the function limits. But allow 185 the function to shrink if it went over the limits by forced inlining. */ 186 newsize = estimate_size_after_inlining (to, e); 187 if (newsize >= info->size 188 && newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS) 189 && newsize > limit) 190 { 191 e->inline_failed = CIF_LARGE_FUNCTION_GROWTH_LIMIT; 192 return false; 193 } 194 195 if (!what_info->estimated_stack_size) 196 return true; 197 198 /* FIXME: Stack size limit often prevents inlining in Fortran programs 199 due to large i/o datastructures used by the Fortran front-end. 200 We ought to ignore this limit when we know that the edge is executed 201 on every invocation of the caller (i.e. its call statement dominates 202 exit block). We do not track this information, yet. */ 203 stack_size_limit += ((gcov_type)stack_size_limit 204 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH) / 100); 205 206 inlined_stack = (outer_info->stack_frame_offset 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 > info->estimated_stack_size 217 && inlined_stack > PARAM_VALUE (PARAM_LARGE_STACK_FRAME)) 218 { 219 e->inline_failed = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT; 220 return false; 221 } 222 return true; 223 } 224 225 /* Dump info about why inlining has failed. */ 226 227 static void 228 report_inline_failed_reason (struct cgraph_edge *e) 229 { 230 if (dump_enabled_p ()) 231 { 232 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 233 " not inlinable: %C -> %C, %s\n", 234 e->caller, e->callee, 235 cgraph_inline_failed_string (e->inline_failed)); 236 if ((e->inline_failed == CIF_TARGET_OPTION_MISMATCH 237 || e->inline_failed == CIF_OPTIMIZATION_MISMATCH) 238 && e->caller->lto_file_data 239 && e->callee->ultimate_alias_target ()->lto_file_data) 240 { 241 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 242 " LTO objects: %s, %s\n", 243 e->caller->lto_file_data->file_name, 244 e->callee->ultimate_alias_target ()->lto_file_data->file_name); 245 } 246 if (e->inline_failed == CIF_TARGET_OPTION_MISMATCH) 247 if (dump_file) 248 cl_target_option_print_diff 249 (dump_file, 2, target_opts_for_fn (e->caller->decl), 250 target_opts_for_fn (e->callee->ultimate_alias_target ()->decl)); 251 if (e->inline_failed == CIF_OPTIMIZATION_MISMATCH) 252 if (dump_file) 253 cl_optimization_print_diff 254 (dump_file, 2, opts_for_fn (e->caller->decl), 255 opts_for_fn (e->callee->ultimate_alias_target ()->decl)); 256 } 257 } 258 259 /* Decide whether sanitizer-related attributes allow inlining. */ 260 261 static bool 262 sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee) 263 { 264 if (!caller || !callee) 265 return true; 266 267 /* Allow inlining always_inline functions into no_sanitize_address 268 functions. */ 269 if (!sanitize_flags_p (SANITIZE_ADDRESS, caller) 270 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee))) 271 return true; 272 273 return ((sanitize_flags_p (SANITIZE_ADDRESS, caller) 274 == sanitize_flags_p (SANITIZE_ADDRESS, callee)) 275 && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller) 276 == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee)) 277 && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller) 278 == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee))); 279 } 280 281 /* Used for flags where it is safe to inline when caller's value is 282 grater than callee's. */ 283 #define check_maybe_up(flag) \ 284 (opts_for_fn (caller->decl)->x_##flag \ 285 != opts_for_fn (callee->decl)->x_##flag \ 286 && (!always_inline \ 287 || opts_for_fn (caller->decl)->x_##flag \ 288 < opts_for_fn (callee->decl)->x_##flag)) 289 /* Used for flags where it is safe to inline when caller's value is 290 smaller than callee's. */ 291 #define check_maybe_down(flag) \ 292 (opts_for_fn (caller->decl)->x_##flag \ 293 != opts_for_fn (callee->decl)->x_##flag \ 294 && (!always_inline \ 295 || opts_for_fn (caller->decl)->x_##flag \ 296 > opts_for_fn (callee->decl)->x_##flag)) 297 /* Used for flags where exact match is needed for correctness. */ 298 #define check_match(flag) \ 299 (opts_for_fn (caller->decl)->x_##flag \ 300 != opts_for_fn (callee->decl)->x_##flag) 301 302 /* Decide if we can inline the edge and possibly update 303 inline_failed reason. 304 We check whether inlining is possible at all and whether 305 caller growth limits allow doing so. 306 307 if REPORT is true, output reason to the dump file. */ 308 309 static bool 310 can_inline_edge_p (struct cgraph_edge *e, bool report, 311 bool early = false) 312 { 313 gcc_checking_assert (e->inline_failed); 314 315 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR) 316 { 317 if (report) 318 report_inline_failed_reason (e); 319 return false; 320 } 321 322 bool inlinable = true; 323 enum availability avail; 324 cgraph_node *caller = e->caller->global.inlined_to 325 ? e->caller->global.inlined_to : e->caller; 326 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller); 327 328 if (!callee->definition) 329 { 330 e->inline_failed = CIF_BODY_NOT_AVAILABLE; 331 inlinable = false; 332 } 333 if (!early && (!opt_for_fn (callee->decl, optimize) 334 || !opt_for_fn (caller->decl, optimize))) 335 { 336 e->inline_failed = CIF_FUNCTION_NOT_OPTIMIZED; 337 inlinable = false; 338 } 339 else if (callee->calls_comdat_local) 340 { 341 e->inline_failed = CIF_USES_COMDAT_LOCAL; 342 inlinable = false; 343 } 344 else if (avail <= AVAIL_INTERPOSABLE) 345 { 346 e->inline_failed = CIF_OVERWRITABLE; 347 inlinable = false; 348 } 349 /* All edges with call_stmt_cannot_inline_p should have inline_failed 350 initialized to one of FINAL_ERROR reasons. */ 351 else if (e->call_stmt_cannot_inline_p) 352 gcc_unreachable (); 353 /* Don't inline if the functions have different EH personalities. */ 354 else if (DECL_FUNCTION_PERSONALITY (caller->decl) 355 && DECL_FUNCTION_PERSONALITY (callee->decl) 356 && (DECL_FUNCTION_PERSONALITY (caller->decl) 357 != DECL_FUNCTION_PERSONALITY (callee->decl))) 358 { 359 e->inline_failed = CIF_EH_PERSONALITY; 360 inlinable = false; 361 } 362 /* TM pure functions should not be inlined into non-TM_pure 363 functions. */ 364 else if (is_tm_pure (callee->decl) && !is_tm_pure (caller->decl)) 365 { 366 e->inline_failed = CIF_UNSPECIFIED; 367 inlinable = false; 368 } 369 /* Check compatibility of target optimization options. */ 370 else if (!targetm.target_option.can_inline_p (caller->decl, 371 callee->decl)) 372 { 373 e->inline_failed = CIF_TARGET_OPTION_MISMATCH; 374 inlinable = false; 375 } 376 else if (ipa_fn_summaries->get (callee) == NULL 377 || !ipa_fn_summaries->get (callee)->inlinable) 378 { 379 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE; 380 inlinable = false; 381 } 382 /* Don't inline a function with mismatched sanitization attributes. */ 383 else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl)) 384 { 385 e->inline_failed = CIF_ATTRIBUTE_MISMATCH; 386 inlinable = false; 387 } 388 if (!inlinable && report) 389 report_inline_failed_reason (e); 390 return inlinable; 391 } 392 393 /* Decide if we can inline the edge and possibly update 394 inline_failed reason. 395 We check whether inlining is possible at all and whether 396 caller growth limits allow doing so. 397 398 if REPORT is true, output reason to the dump file. 399 400 if DISREGARD_LIMITS is true, ignore size limits. */ 401 402 static bool 403 can_inline_edge_by_limits_p (struct cgraph_edge *e, bool report, 404 bool disregard_limits = false, bool early = false) 405 { 406 gcc_checking_assert (e->inline_failed); 407 408 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR) 409 { 410 if (report) 411 report_inline_failed_reason (e); 412 return false; 413 } 414 415 bool inlinable = true; 416 enum availability avail; 417 cgraph_node *caller = e->caller->global.inlined_to 418 ? e->caller->global.inlined_to : e->caller; 419 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller); 420 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl); 421 tree callee_tree 422 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL; 423 /* Check if caller growth allows the inlining. */ 424 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl) 425 && !disregard_limits 426 && !lookup_attribute ("flatten", 427 DECL_ATTRIBUTES (caller->decl)) 428 && !caller_growth_limits (e)) 429 inlinable = false; 430 else if (callee->externally_visible 431 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl) 432 && flag_live_patching == LIVE_PATCHING_INLINE_ONLY_STATIC) 433 { 434 e->inline_failed = CIF_EXTERN_LIVE_ONLY_STATIC; 435 inlinable = false; 436 } 437 /* Don't inline a function with a higher optimization level than the 438 caller. FIXME: this is really just tip of iceberg of handling 439 optimization attribute. */ 440 else if (caller_tree != callee_tree) 441 { 442 bool always_inline = 443 (DECL_DISREGARD_INLINE_LIMITS (callee->decl) 444 && lookup_attribute ("always_inline", 445 DECL_ATTRIBUTES (callee->decl))); 446 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller); 447 ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee); 448 449 /* Until GCC 4.9 we did not check the semantics-altering flags 450 below and inlined across optimization boundaries. 451 Enabling checks below breaks several packages by refusing 452 to inline library always_inline functions. See PR65873. 453 Disable the check for early inlining for now until better solution 454 is found. */ 455 if (always_inline && early) 456 ; 457 /* There are some options that change IL semantics which means 458 we cannot inline in these cases for correctness reason. 459 Not even for always_inline declared functions. */ 460 else if (check_match (flag_wrapv) 461 || check_match (flag_trapv) 462 || check_match (flag_pcc_struct_return) 463 /* When caller or callee does FP math, be sure FP codegen flags 464 compatible. */ 465 || ((caller_info->fp_expressions && callee_info->fp_expressions) 466 && (check_maybe_up (flag_rounding_math) 467 || check_maybe_up (flag_trapping_math) 468 || check_maybe_down (flag_unsafe_math_optimizations) 469 || check_maybe_down (flag_finite_math_only) 470 || check_maybe_up (flag_signaling_nans) 471 || check_maybe_down (flag_cx_limited_range) 472 || check_maybe_up (flag_signed_zeros) 473 || check_maybe_down (flag_associative_math) 474 || check_maybe_down (flag_reciprocal_math) 475 || check_maybe_down (flag_fp_int_builtin_inexact) 476 /* Strictly speaking only when the callee contains function 477 calls that may end up setting errno. */ 478 || check_maybe_up (flag_errno_math))) 479 /* We do not want to make code compiled with exceptions to be 480 brought into a non-EH function unless we know that the callee 481 does not throw. 482 This is tracked by DECL_FUNCTION_PERSONALITY. */ 483 || (check_maybe_up (flag_non_call_exceptions) 484 && DECL_FUNCTION_PERSONALITY (callee->decl)) 485 || (check_maybe_up (flag_exceptions) 486 && DECL_FUNCTION_PERSONALITY (callee->decl)) 487 /* When devirtualization is diabled for callee, it is not safe 488 to inline it as we possibly mangled the type info. 489 Allow early inlining of always inlines. */ 490 || (!early && check_maybe_down (flag_devirtualize))) 491 { 492 e->inline_failed = CIF_OPTIMIZATION_MISMATCH; 493 inlinable = false; 494 } 495 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */ 496 else if (always_inline) 497 ; 498 /* When user added an attribute to the callee honor it. */ 499 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee->decl)) 500 && opts_for_fn (caller->decl) != opts_for_fn (callee->decl)) 501 { 502 e->inline_failed = CIF_OPTIMIZATION_MISMATCH; 503 inlinable = false; 504 } 505 /* If explicit optimize attribute are not used, the mismatch is caused 506 by different command line options used to build different units. 507 Do not care about COMDAT functions - those are intended to be 508 optimized with the optimization flags of module they are used in. 509 Also do not care about mixing up size/speed optimization when 510 DECL_DISREGARD_INLINE_LIMITS is set. */ 511 else if ((callee->merged_comdat 512 && !lookup_attribute ("optimize", 513 DECL_ATTRIBUTES (caller->decl))) 514 || DECL_DISREGARD_INLINE_LIMITS (callee->decl)) 515 ; 516 /* If mismatch is caused by merging two LTO units with different 517 optimizationflags we want to be bit nicer. However never inline 518 if one of functions is not optimized at all. */ 519 else if (!opt_for_fn (callee->decl, optimize) 520 || !opt_for_fn (caller->decl, optimize)) 521 { 522 e->inline_failed = CIF_OPTIMIZATION_MISMATCH; 523 inlinable = false; 524 } 525 /* If callee is optimized for size and caller is not, allow inlining if 526 code shrinks or we are in MAX_INLINE_INSNS_SINGLE limit and callee 527 is inline (and thus likely an unified comdat). This will allow caller 528 to run faster. */ 529 else if (opt_for_fn (callee->decl, optimize_size) 530 > opt_for_fn (caller->decl, optimize_size)) 531 { 532 int growth = estimate_edge_growth (e); 533 if (growth > PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SIZE) 534 && (!DECL_DECLARED_INLINE_P (callee->decl) 535 && growth >= MAX (MAX_INLINE_INSNS_SINGLE, 536 MAX_INLINE_INSNS_AUTO))) 537 { 538 e->inline_failed = CIF_OPTIMIZATION_MISMATCH; 539 inlinable = false; 540 } 541 } 542 /* If callee is more aggressively optimized for performance than caller, 543 we generally want to inline only cheap (runtime wise) functions. */ 544 else if (opt_for_fn (callee->decl, optimize_size) 545 < opt_for_fn (caller->decl, optimize_size) 546 || (opt_for_fn (callee->decl, optimize) 547 > opt_for_fn (caller->decl, optimize))) 548 { 549 if (estimate_edge_time (e) 550 >= 20 + ipa_call_summaries->get (e)->call_stmt_time) 551 { 552 e->inline_failed = CIF_OPTIMIZATION_MISMATCH; 553 inlinable = false; 554 } 555 } 556 557 } 558 559 if (!inlinable && report) 560 report_inline_failed_reason (e); 561 return inlinable; 562 } 563 564 565 /* Return true if the edge E is inlinable during early inlining. */ 566 567 static bool 568 can_early_inline_edge_p (struct cgraph_edge *e) 569 { 570 struct cgraph_node *callee = e->callee->ultimate_alias_target (); 571 /* Early inliner might get called at WPA stage when IPA pass adds new 572 function. In this case we cannot really do any of early inlining 573 because function bodies are missing. */ 574 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR) 575 return false; 576 if (!gimple_has_body_p (callee->decl)) 577 { 578 e->inline_failed = CIF_BODY_NOT_AVAILABLE; 579 return false; 580 } 581 /* In early inliner some of callees may not be in SSA form yet 582 (i.e. the callgraph is cyclic and we did not process 583 the callee by early inliner, yet). We don't have CIF code for this 584 case; later we will re-do the decision in the real inliner. */ 585 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl)) 586 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl))) 587 { 588 if (dump_enabled_p ()) 589 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 590 " edge not inlinable: not in SSA form\n"); 591 return false; 592 } 593 if (!can_inline_edge_p (e, true, true) 594 || !can_inline_edge_by_limits_p (e, true, false, true)) 595 return false; 596 return true; 597 } 598 599 600 /* Return number of calls in N. Ignore cheap builtins. */ 601 602 static int 603 num_calls (struct cgraph_node *n) 604 { 605 struct cgraph_edge *e; 606 int num = 0; 607 608 for (e = n->callees; e; e = e->next_callee) 609 if (!is_inexpensive_builtin (e->callee->decl)) 610 num++; 611 return num; 612 } 613 614 615 /* Return true if we are interested in inlining small function. */ 616 617 static bool 618 want_early_inline_function_p (struct cgraph_edge *e) 619 { 620 bool want_inline = true; 621 struct cgraph_node *callee = e->callee->ultimate_alias_target (); 622 623 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl)) 624 ; 625 /* For AutoFDO, we need to make sure that before profile summary, all 626 hot paths' IR look exactly the same as profiled binary. As a result, 627 in einliner, we will disregard size limit and inline those callsites 628 that are: 629 * inlined in the profiled binary, and 630 * the cloned callee has enough samples to be considered "hot". */ 631 else if (flag_auto_profile && afdo_callsite_hot_enough_for_early_inline (e)) 632 ; 633 else if (!DECL_DECLARED_INLINE_P (callee->decl) 634 && !opt_for_fn (e->caller->decl, flag_inline_small_functions)) 635 { 636 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE; 637 report_inline_failed_reason (e); 638 want_inline = false; 639 } 640 else 641 { 642 int growth = estimate_edge_growth (e); 643 int n; 644 645 if (growth <= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SIZE)) 646 ; 647 else if (!e->maybe_hot_p ()) 648 { 649 if (dump_enabled_p ()) 650 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 651 " will not early inline: %C->%C, " 652 "call is cold and code would grow by %i\n", 653 e->caller, callee, 654 growth); 655 want_inline = false; 656 } 657 else if (growth > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS)) 658 { 659 if (dump_enabled_p ()) 660 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 661 " will not early inline: %C->%C, " 662 "growth %i exceeds --param early-inlining-insns\n", 663 e->caller, callee, 664 growth); 665 want_inline = false; 666 } 667 else if ((n = num_calls (callee)) != 0 668 && growth * (n + 1) > PARAM_VALUE (PARAM_EARLY_INLINING_INSNS)) 669 { 670 if (dump_enabled_p ()) 671 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 672 " will not early inline: %C->%C, " 673 "growth %i exceeds --param early-inlining-insns " 674 "divided by number of calls\n", 675 e->caller, callee, 676 growth); 677 want_inline = false; 678 } 679 } 680 return want_inline; 681 } 682 683 /* Compute time of the edge->caller + edge->callee execution when inlining 684 does not happen. */ 685 686 inline sreal 687 compute_uninlined_call_time (struct cgraph_edge *edge, 688 sreal uninlined_call_time) 689 { 690 cgraph_node *caller = (edge->caller->global.inlined_to 691 ? edge->caller->global.inlined_to 692 : edge->caller); 693 694 sreal freq = edge->sreal_frequency (); 695 if (freq > 0) 696 uninlined_call_time *= freq; 697 else 698 uninlined_call_time = uninlined_call_time >> 11; 699 700 sreal caller_time = ipa_fn_summaries->get (caller)->time; 701 return uninlined_call_time + caller_time; 702 } 703 704 /* Same as compute_uinlined_call_time but compute time when inlining 705 does happen. */ 706 707 inline sreal 708 compute_inlined_call_time (struct cgraph_edge *edge, 709 sreal time) 710 { 711 cgraph_node *caller = (edge->caller->global.inlined_to 712 ? edge->caller->global.inlined_to 713 : edge->caller); 714 sreal caller_time = ipa_fn_summaries->get (caller)->time; 715 716 sreal freq = edge->sreal_frequency (); 717 if (freq > 0) 718 time *= freq; 719 else 720 time = time >> 11; 721 722 /* This calculation should match one in ipa-inline-analysis.c 723 (estimate_edge_size_and_time). */ 724 time -= (sreal)ipa_call_summaries->get (edge)->call_stmt_time * freq; 725 time += caller_time; 726 if (time <= 0) 727 time = ((sreal) 1) >> 8; 728 gcc_checking_assert (time >= 0); 729 return time; 730 } 731 732 /* Return true if the speedup for inlining E is bigger than 733 PARAM_MAX_INLINE_MIN_SPEEDUP. */ 734 735 static bool 736 big_speedup_p (struct cgraph_edge *e) 737 { 738 sreal unspec_time; 739 sreal spec_time = estimate_edge_time (e, &unspec_time); 740 sreal time = compute_uninlined_call_time (e, unspec_time); 741 sreal inlined_time = compute_inlined_call_time (e, spec_time); 742 743 if ((time - inlined_time) * 100 744 > (sreal) (time * PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP))) 745 return true; 746 return false; 747 } 748 749 /* Return true if we are interested in inlining small function. 750 When REPORT is true, report reason to dump file. */ 751 752 static bool 753 want_inline_small_function_p (struct cgraph_edge *e, bool report) 754 { 755 bool want_inline = true; 756 struct cgraph_node *callee = e->callee->ultimate_alias_target (); 757 758 /* Allow this function to be called before can_inline_edge_p, 759 since it's usually cheaper. */ 760 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR) 761 want_inline = false; 762 else if (DECL_DISREGARD_INLINE_LIMITS (callee->decl)) 763 ; 764 else if (!DECL_DECLARED_INLINE_P (callee->decl) 765 && !opt_for_fn (e->caller->decl, flag_inline_small_functions)) 766 { 767 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE; 768 want_inline = false; 769 } 770 /* Do fast and conservative check if the function can be good 771 inline candidate. At the moment we allow inline hints to 772 promote non-inline functions to inline and we increase 773 MAX_INLINE_INSNS_SINGLE 16-fold for inline functions. */ 774 else if ((!DECL_DECLARED_INLINE_P (callee->decl) 775 && (!e->count.ipa ().initialized_p () || !e->maybe_hot_p ())) 776 && ipa_fn_summaries->get (callee)->min_size 777 - ipa_call_summaries->get (e)->call_stmt_size 778 > MAX (MAX_INLINE_INSNS_SINGLE, MAX_INLINE_INSNS_AUTO)) 779 { 780 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT; 781 want_inline = false; 782 } 783 else if ((DECL_DECLARED_INLINE_P (callee->decl) 784 || e->count.ipa ().nonzero_p ()) 785 && ipa_fn_summaries->get (callee)->min_size 786 - ipa_call_summaries->get (e)->call_stmt_size 787 > 16 * MAX_INLINE_INSNS_SINGLE) 788 { 789 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl) 790 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT 791 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT); 792 want_inline = false; 793 } 794 else 795 { 796 int growth = estimate_edge_growth (e); 797 ipa_hints hints = estimate_edge_hints (e); 798 int big_speedup = -1; /* compute this lazily */ 799 800 if (growth <= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SIZE)) 801 ; 802 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when 803 hints suggests that inlining given function is very profitable. */ 804 else if (DECL_DECLARED_INLINE_P (callee->decl) 805 && growth >= MAX_INLINE_INSNS_SINGLE 806 && (growth >= MAX_INLINE_INSNS_SINGLE * 16 807 || (!(hints & (INLINE_HINT_indirect_call 808 | INLINE_HINT_known_hot 809 | INLINE_HINT_loop_iterations 810 | INLINE_HINT_array_index 811 | INLINE_HINT_loop_stride)) 812 && !(big_speedup = big_speedup_p (e))))) 813 { 814 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT; 815 want_inline = false; 816 } 817 else if (!DECL_DECLARED_INLINE_P (callee->decl) 818 && !opt_for_fn (e->caller->decl, flag_inline_functions) 819 && growth >= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SMALL)) 820 { 821 /* growth_likely_positive is expensive, always test it last. */ 822 if (growth >= MAX_INLINE_INSNS_SINGLE 823 || growth_likely_positive (callee, growth)) 824 { 825 e->inline_failed = CIF_NOT_DECLARED_INLINED; 826 want_inline = false; 827 } 828 } 829 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline 830 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that 831 inlining given function is very profitable. */ 832 else if (!DECL_DECLARED_INLINE_P (callee->decl) 833 && !(hints & INLINE_HINT_known_hot) 834 && growth >= ((hints & (INLINE_HINT_indirect_call 835 | INLINE_HINT_loop_iterations 836 | INLINE_HINT_array_index 837 | INLINE_HINT_loop_stride)) 838 ? MAX (MAX_INLINE_INSNS_AUTO, 839 MAX_INLINE_INSNS_SINGLE) 840 : MAX_INLINE_INSNS_AUTO) 841 && !(big_speedup == -1 ? big_speedup_p (e) : big_speedup)) 842 { 843 /* growth_likely_positive is expensive, always test it last. */ 844 if (growth >= MAX_INLINE_INSNS_SINGLE 845 || growth_likely_positive (callee, growth)) 846 { 847 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT; 848 want_inline = false; 849 } 850 } 851 /* If call is cold, do not inline when function body would grow. */ 852 else if (!e->maybe_hot_p () 853 && (growth >= MAX_INLINE_INSNS_SINGLE 854 || growth_likely_positive (callee, growth))) 855 { 856 e->inline_failed = CIF_UNLIKELY_CALL; 857 want_inline = false; 858 } 859 } 860 if (!want_inline && report) 861 report_inline_failed_reason (e); 862 return want_inline; 863 } 864 865 /* EDGE is self recursive edge. 866 We hand two cases - when function A is inlining into itself 867 or when function A is being inlined into another inliner copy of function 868 A within function B. 869 870 In first case OUTER_NODE points to the toplevel copy of A, while 871 in the second case OUTER_NODE points to the outermost copy of A in B. 872 873 In both cases we want to be extra selective since 874 inlining the call will just introduce new recursive calls to appear. */ 875 876 static bool 877 want_inline_self_recursive_call_p (struct cgraph_edge *edge, 878 struct cgraph_node *outer_node, 879 bool peeling, 880 int depth) 881 { 882 char const *reason = NULL; 883 bool want_inline = true; 884 sreal caller_freq = 1; 885 int max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO); 886 887 if (DECL_DECLARED_INLINE_P (edge->caller->decl)) 888 max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH); 889 890 if (!edge->maybe_hot_p ()) 891 { 892 reason = "recursive call is cold"; 893 want_inline = false; 894 } 895 else if (depth > max_depth) 896 { 897 reason = "--param max-inline-recursive-depth exceeded."; 898 want_inline = false; 899 } 900 else if (outer_node->global.inlined_to 901 && (caller_freq = outer_node->callers->sreal_frequency ()) == 0) 902 { 903 reason = "caller frequency is 0"; 904 want_inline = false; 905 } 906 907 if (!want_inline) 908 ; 909 /* Inlining of self recursive function into copy of itself within other 910 function is transformation similar to loop peeling. 911 912 Peeling is profitable if we can inline enough copies to make probability 913 of actual call to the self recursive function very small. Be sure that 914 the probability of recursion is small. 915 916 We ensure that the frequency of recursing is at most 1 - (1/max_depth). 917 This way the expected number of recursion is at most max_depth. */ 918 else if (peeling) 919 { 920 sreal max_prob = (sreal)1 - ((sreal)1 / (sreal)max_depth); 921 int i; 922 for (i = 1; i < depth; i++) 923 max_prob = max_prob * max_prob; 924 if (edge->sreal_frequency () >= max_prob * caller_freq) 925 { 926 reason = "frequency of recursive call is too large"; 927 want_inline = false; 928 } 929 } 930 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if 931 recursion depth is large. We reduce function call overhead and increase 932 chances that things fit in hardware return predictor. 933 934 Recursive inlining might however increase cost of stack frame setup 935 actually slowing down functions whose recursion tree is wide rather than 936 deep. 937 938 Deciding reliably on when to do recursive inlining without profile feedback 939 is tricky. For now we disable recursive inlining when probability of self 940 recursion is low. 941 942 Recursive inlining of self recursive call within loop also results in 943 large loop depths that generally optimize badly. We may want to throttle 944 down inlining in those cases. In particular this seems to happen in one 945 of libstdc++ rb tree methods. */ 946 else 947 { 948 if (edge->sreal_frequency () * 100 949 <= caller_freq 950 * PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY)) 951 { 952 reason = "frequency of recursive call is too small"; 953 want_inline = false; 954 } 955 } 956 if (!want_inline && dump_enabled_p ()) 957 dump_printf_loc (MSG_MISSED_OPTIMIZATION, edge->call_stmt, 958 " not inlining recursively: %s\n", reason); 959 return want_inline; 960 } 961 962 /* Return true when NODE has uninlinable caller; 963 set HAS_HOT_CALL if it has hot call. 964 Worker for cgraph_for_node_and_aliases. */ 965 966 static bool 967 check_callers (struct cgraph_node *node, void *has_hot_call) 968 { 969 struct cgraph_edge *e; 970 for (e = node->callers; e; e = e->next_caller) 971 { 972 if (!opt_for_fn (e->caller->decl, flag_inline_functions_called_once) 973 || !opt_for_fn (e->caller->decl, optimize)) 974 return true; 975 if (!can_inline_edge_p (e, true)) 976 return true; 977 if (e->recursive_p ()) 978 return true; 979 if (!can_inline_edge_by_limits_p (e, true)) 980 return true; 981 if (!(*(bool *)has_hot_call) && e->maybe_hot_p ()) 982 *(bool *)has_hot_call = true; 983 } 984 return false; 985 } 986 987 /* If NODE has a caller, return true. */ 988 989 static bool 990 has_caller_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) 991 { 992 if (node->callers) 993 return true; 994 return false; 995 } 996 997 /* Decide if inlining NODE would reduce unit size by eliminating 998 the offline copy of function. 999 When COLD is true the cold calls are considered, too. */ 1000 1001 static bool 1002 want_inline_function_to_all_callers_p (struct cgraph_node *node, bool cold) 1003 { 1004 bool has_hot_call = false; 1005 1006 /* Aliases gets inlined along with the function they alias. */ 1007 if (node->alias) 1008 return false; 1009 /* Already inlined? */ 1010 if (node->global.inlined_to) 1011 return false; 1012 /* Does it have callers? */ 1013 if (!node->call_for_symbol_and_aliases (has_caller_p, NULL, true)) 1014 return false; 1015 /* Inlining into all callers would increase size? */ 1016 if (estimate_growth (node) > 0) 1017 return false; 1018 /* All inlines must be possible. */ 1019 if (node->call_for_symbol_and_aliases (check_callers, &has_hot_call, 1020 true)) 1021 return false; 1022 if (!cold && !has_hot_call) 1023 return false; 1024 return true; 1025 } 1026 1027 /* A cost model driving the inlining heuristics in a way so the edges with 1028 smallest badness are inlined first. After each inlining is performed 1029 the costs of all caller edges of nodes affected are recomputed so the 1030 metrics may accurately depend on values such as number of inlinable callers 1031 of the function or function body size. */ 1032 1033 static sreal 1034 edge_badness (struct cgraph_edge *edge, bool dump) 1035 { 1036 sreal badness; 1037 int growth; 1038 sreal edge_time, unspec_edge_time; 1039 struct cgraph_node *callee = edge->callee->ultimate_alias_target (); 1040 struct ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee); 1041 ipa_hints hints; 1042 cgraph_node *caller = (edge->caller->global.inlined_to 1043 ? edge->caller->global.inlined_to 1044 : edge->caller); 1045 1046 growth = estimate_edge_growth (edge); 1047 edge_time = estimate_edge_time (edge, &unspec_edge_time); 1048 hints = estimate_edge_hints (edge); 1049 gcc_checking_assert (edge_time >= 0); 1050 /* Check that inlined time is better, but tolerate some roundoff issues. 1051 FIXME: When callee profile drops to 0 we account calls more. This 1052 should be fixed by never doing that. */ 1053 gcc_checking_assert ((edge_time * 100 1054 - callee_info->time * 101).to_int () <= 0 1055 || callee->count.ipa ().initialized_p ()); 1056 gcc_checking_assert (growth <= callee_info->size); 1057 1058 if (dump) 1059 { 1060 fprintf (dump_file, " Badness calculation for %s -> %s\n", 1061 edge->caller->dump_name (), 1062 edge->callee->dump_name ()); 1063 fprintf (dump_file, " size growth %i, time %f unspec %f ", 1064 growth, 1065 edge_time.to_double (), 1066 unspec_edge_time.to_double ()); 1067 ipa_dump_hints (dump_file, hints); 1068 if (big_speedup_p (edge)) 1069 fprintf (dump_file, " big_speedup"); 1070 fprintf (dump_file, "\n"); 1071 } 1072 1073 /* Always prefer inlining saving code size. */ 1074 if (growth <= 0) 1075 { 1076 badness = (sreal) (-SREAL_MIN_SIG + growth) << (SREAL_MAX_EXP / 256); 1077 if (dump) 1078 fprintf (dump_file, " %f: Growth %d <= 0\n", badness.to_double (), 1079 growth); 1080 } 1081 /* Inlining into EXTERNAL functions is not going to change anything unless 1082 they are themselves inlined. */ 1083 else if (DECL_EXTERNAL (caller->decl)) 1084 { 1085 if (dump) 1086 fprintf (dump_file, " max: function is external\n"); 1087 return sreal::max (); 1088 } 1089 /* When profile is available. Compute badness as: 1090 1091 time_saved * caller_count 1092 goodness = ------------------------------------------------- 1093 growth_of_caller * overall_growth * combined_size 1094 1095 badness = - goodness 1096 1097 Again use negative value to make calls with profile appear hotter 1098 then calls without. 1099 */ 1100 else if (opt_for_fn (caller->decl, flag_guess_branch_prob) 1101 || caller->count.ipa ().nonzero_p ()) 1102 { 1103 sreal numerator, denominator; 1104 int overall_growth; 1105 sreal inlined_time = compute_inlined_call_time (edge, edge_time); 1106 1107 numerator = (compute_uninlined_call_time (edge, unspec_edge_time) 1108 - inlined_time); 1109 if (numerator <= 0) 1110 numerator = ((sreal) 1 >> 8); 1111 if (caller->count.ipa ().nonzero_p ()) 1112 numerator *= caller->count.ipa ().to_gcov_type (); 1113 else if (caller->count.ipa ().initialized_p ()) 1114 numerator = numerator >> 11; 1115 denominator = growth; 1116 1117 overall_growth = callee_info->growth; 1118 1119 /* Look for inliner wrappers of the form: 1120 1121 inline_caller () 1122 { 1123 do_fast_job... 1124 if (need_more_work) 1125 noninline_callee (); 1126 } 1127 Withhout panilizing this case, we usually inline noninline_callee 1128 into the inline_caller because overall_growth is small preventing 1129 further inlining of inline_caller. 1130 1131 Penalize only callgraph edges to functions with small overall 1132 growth ... 1133 */ 1134 if (growth > overall_growth 1135 /* ... and having only one caller which is not inlined ... */ 1136 && callee_info->single_caller 1137 && !edge->caller->global.inlined_to 1138 /* ... and edges executed only conditionally ... */ 1139 && edge->sreal_frequency () < 1 1140 /* ... consider case where callee is not inline but caller is ... */ 1141 && ((!DECL_DECLARED_INLINE_P (edge->callee->decl) 1142 && DECL_DECLARED_INLINE_P (caller->decl)) 1143 /* ... or when early optimizers decided to split and edge 1144 frequency still indicates splitting is a win ... */ 1145 || (callee->split_part && !caller->split_part 1146 && edge->sreal_frequency () * 100 1147 < PARAM_VALUE 1148 (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY) 1149 /* ... and do not overwrite user specified hints. */ 1150 && (!DECL_DECLARED_INLINE_P (edge->callee->decl) 1151 || DECL_DECLARED_INLINE_P (caller->decl))))) 1152 { 1153 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller); 1154 int caller_growth = caller_info->growth; 1155 1156 /* Only apply the penalty when caller looks like inline candidate, 1157 and it is not called once and. */ 1158 if (!caller_info->single_caller && overall_growth < caller_growth 1159 && caller_info->inlinable 1160 && caller_info->size 1161 < (DECL_DECLARED_INLINE_P (caller->decl) 1162 ? MAX_INLINE_INSNS_SINGLE : MAX_INLINE_INSNS_AUTO)) 1163 { 1164 if (dump) 1165 fprintf (dump_file, 1166 " Wrapper penalty. Increasing growth %i to %i\n", 1167 overall_growth, caller_growth); 1168 overall_growth = caller_growth; 1169 } 1170 } 1171 if (overall_growth > 0) 1172 { 1173 /* Strongly preffer functions with few callers that can be inlined 1174 fully. The square root here leads to smaller binaries at average. 1175 Watch however for extreme cases and return to linear function 1176 when growth is large. */ 1177 if (overall_growth < 256) 1178 overall_growth *= overall_growth; 1179 else 1180 overall_growth += 256 * 256 - 256; 1181 denominator *= overall_growth; 1182 } 1183 denominator *= ipa_fn_summaries->get (caller)->self_size + growth; 1184 1185 badness = - numerator / denominator; 1186 1187 if (dump) 1188 { 1189 fprintf (dump_file, 1190 " %f: guessed profile. frequency %f, count %" PRId64 1191 " caller count %" PRId64 1192 " time w/o inlining %f, time with inlining %f" 1193 " overall growth %i (current) %i (original)" 1194 " %i (compensated)\n", 1195 badness.to_double (), 1196 edge->sreal_frequency ().to_double (), 1197 edge->count.ipa ().initialized_p () ? edge->count.ipa ().to_gcov_type () : -1, 1198 caller->count.ipa ().initialized_p () ? caller->count.ipa ().to_gcov_type () : -1, 1199 compute_uninlined_call_time (edge, 1200 unspec_edge_time).to_double (), 1201 inlined_time.to_double (), 1202 estimate_growth (callee), 1203 callee_info->growth, overall_growth); 1204 } 1205 } 1206 /* When function local profile is not available or it does not give 1207 useful information (ie frequency is zero), base the cost on 1208 loop nest and overall size growth, so we optimize for overall number 1209 of functions fully inlined in program. */ 1210 else 1211 { 1212 int nest = MIN (ipa_call_summaries->get (edge)->loop_depth, 8); 1213 badness = growth; 1214 1215 /* Decrease badness if call is nested. */ 1216 if (badness > 0) 1217 badness = badness >> nest; 1218 else 1219 badness = badness << nest; 1220 if (dump) 1221 fprintf (dump_file, " %f: no profile. nest %i\n", 1222 badness.to_double (), nest); 1223 } 1224 gcc_checking_assert (badness != 0); 1225 1226 if (edge->recursive_p ()) 1227 badness = badness.shift (badness > 0 ? 4 : -4); 1228 if ((hints & (INLINE_HINT_indirect_call 1229 | INLINE_HINT_loop_iterations 1230 | INLINE_HINT_array_index 1231 | INLINE_HINT_loop_stride)) 1232 || callee_info->growth <= 0) 1233 badness = badness.shift (badness > 0 ? -2 : 2); 1234 if (hints & (INLINE_HINT_same_scc)) 1235 badness = badness.shift (badness > 0 ? 3 : -3); 1236 else if (hints & (INLINE_HINT_in_scc)) 1237 badness = badness.shift (badness > 0 ? 2 : -2); 1238 else if (hints & (INLINE_HINT_cross_module)) 1239 badness = badness.shift (badness > 0 ? 1 : -1); 1240 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl)) 1241 badness = badness.shift (badness > 0 ? -4 : 4); 1242 else if ((hints & INLINE_HINT_declared_inline)) 1243 badness = badness.shift (badness > 0 ? -3 : 3); 1244 if (dump) 1245 fprintf (dump_file, " Adjusted by hints %f\n", badness.to_double ()); 1246 return badness; 1247 } 1248 1249 /* Recompute badness of EDGE and update its key in HEAP if needed. */ 1250 static inline void 1251 update_edge_key (edge_heap_t *heap, struct cgraph_edge *edge) 1252 { 1253 sreal badness = edge_badness (edge, false); 1254 if (edge->aux) 1255 { 1256 edge_heap_node_t *n = (edge_heap_node_t *) edge->aux; 1257 gcc_checking_assert (n->get_data () == edge); 1258 1259 /* fibonacci_heap::replace_key does busy updating of the 1260 heap that is unnecesarily expensive. 1261 We do lazy increases: after extracting minimum if the key 1262 turns out to be out of date, it is re-inserted into heap 1263 with correct value. */ 1264 if (badness < n->get_key ()) 1265 { 1266 if (dump_file && (dump_flags & TDF_DETAILS)) 1267 { 1268 fprintf (dump_file, 1269 " decreasing badness %s -> %s, %f to %f\n", 1270 edge->caller->dump_name (), 1271 edge->callee->dump_name (), 1272 n->get_key ().to_double (), 1273 badness.to_double ()); 1274 } 1275 heap->decrease_key (n, badness); 1276 } 1277 } 1278 else 1279 { 1280 if (dump_file && (dump_flags & TDF_DETAILS)) 1281 { 1282 fprintf (dump_file, 1283 " enqueuing call %s -> %s, badness %f\n", 1284 edge->caller->dump_name (), 1285 edge->callee->dump_name (), 1286 badness.to_double ()); 1287 } 1288 edge->aux = heap->insert (badness, edge); 1289 } 1290 } 1291 1292 1293 /* NODE was inlined. 1294 All caller edges needs to be resetted because 1295 size estimates change. Similarly callees needs reset 1296 because better context may be known. */ 1297 1298 static void 1299 reset_edge_caches (struct cgraph_node *node) 1300 { 1301 struct cgraph_edge *edge; 1302 struct cgraph_edge *e = node->callees; 1303 struct cgraph_node *where = node; 1304 struct ipa_ref *ref; 1305 1306 if (where->global.inlined_to) 1307 where = where->global.inlined_to; 1308 1309 if (edge_growth_cache != NULL) 1310 for (edge = where->callers; edge; edge = edge->next_caller) 1311 if (edge->inline_failed) 1312 edge_growth_cache->remove (edge); 1313 1314 FOR_EACH_ALIAS (where, ref) 1315 reset_edge_caches (dyn_cast <cgraph_node *> (ref->referring)); 1316 1317 if (!e) 1318 return; 1319 1320 while (true) 1321 if (!e->inline_failed && e->callee->callees) 1322 e = e->callee->callees; 1323 else 1324 { 1325 if (edge_growth_cache != NULL && e->inline_failed) 1326 edge_growth_cache->remove (e); 1327 if (e->next_callee) 1328 e = e->next_callee; 1329 else 1330 { 1331 do 1332 { 1333 if (e->caller == node) 1334 return; 1335 e = e->caller->callers; 1336 } 1337 while (!e->next_callee); 1338 e = e->next_callee; 1339 } 1340 } 1341 } 1342 1343 /* Recompute HEAP nodes for each of caller of NODE. 1344 UPDATED_NODES track nodes we already visited, to avoid redundant work. 1345 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that 1346 it is inlinable. Otherwise check all edges. */ 1347 1348 static void 1349 update_caller_keys (edge_heap_t *heap, struct cgraph_node *node, 1350 bitmap updated_nodes, 1351 struct cgraph_edge *check_inlinablity_for) 1352 { 1353 struct cgraph_edge *edge; 1354 struct ipa_ref *ref; 1355 1356 if ((!node->alias && !ipa_fn_summaries->get (node)->inlinable) 1357 || node->global.inlined_to) 1358 return; 1359 if (!bitmap_set_bit (updated_nodes, node->get_uid ())) 1360 return; 1361 1362 FOR_EACH_ALIAS (node, ref) 1363 { 1364 struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring); 1365 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for); 1366 } 1367 1368 for (edge = node->callers; edge; edge = edge->next_caller) 1369 if (edge->inline_failed) 1370 { 1371 if (!check_inlinablity_for 1372 || check_inlinablity_for == edge) 1373 { 1374 if (can_inline_edge_p (edge, false) 1375 && want_inline_small_function_p (edge, false) 1376 && can_inline_edge_by_limits_p (edge, false)) 1377 update_edge_key (heap, edge); 1378 else if (edge->aux) 1379 { 1380 report_inline_failed_reason (edge); 1381 heap->delete_node ((edge_heap_node_t *) edge->aux); 1382 edge->aux = NULL; 1383 } 1384 } 1385 else if (edge->aux) 1386 update_edge_key (heap, edge); 1387 } 1388 } 1389 1390 /* Recompute HEAP nodes for each uninlined call in NODE. 1391 This is used when we know that edge badnesses are going only to increase 1392 (we introduced new call site) and thus all we need is to insert newly 1393 created edges into heap. */ 1394 1395 static void 1396 update_callee_keys (edge_heap_t *heap, struct cgraph_node *node, 1397 bitmap updated_nodes) 1398 { 1399 struct cgraph_edge *e = node->callees; 1400 1401 if (!e) 1402 return; 1403 while (true) 1404 if (!e->inline_failed && e->callee->callees) 1405 e = e->callee->callees; 1406 else 1407 { 1408 enum availability avail; 1409 struct cgraph_node *callee; 1410 /* We do not reset callee growth cache here. Since we added a new call, 1411 growth chould have just increased and consequentely badness metric 1412 don't need updating. */ 1413 if (e->inline_failed 1414 && (callee = e->callee->ultimate_alias_target (&avail, e->caller)) 1415 && ipa_fn_summaries->get (callee) != NULL 1416 && ipa_fn_summaries->get (callee)->inlinable 1417 && avail >= AVAIL_AVAILABLE 1418 && !bitmap_bit_p (updated_nodes, callee->get_uid ())) 1419 { 1420 if (can_inline_edge_p (e, false) 1421 && want_inline_small_function_p (e, false) 1422 && can_inline_edge_by_limits_p (e, false)) 1423 update_edge_key (heap, e); 1424 else if (e->aux) 1425 { 1426 report_inline_failed_reason (e); 1427 heap->delete_node ((edge_heap_node_t *) e->aux); 1428 e->aux = NULL; 1429 } 1430 } 1431 if (e->next_callee) 1432 e = e->next_callee; 1433 else 1434 { 1435 do 1436 { 1437 if (e->caller == node) 1438 return; 1439 e = e->caller->callers; 1440 } 1441 while (!e->next_callee); 1442 e = e->next_callee; 1443 } 1444 } 1445 } 1446 1447 /* Enqueue all recursive calls from NODE into priority queue depending on 1448 how likely we want to recursively inline the call. */ 1449 1450 static void 1451 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where, 1452 edge_heap_t *heap) 1453 { 1454 struct cgraph_edge *e; 1455 enum availability avail; 1456 1457 for (e = where->callees; e; e = e->next_callee) 1458 if (e->callee == node 1459 || (e->callee->ultimate_alias_target (&avail, e->caller) == node 1460 && avail > AVAIL_INTERPOSABLE)) 1461 heap->insert (-e->sreal_frequency (), e); 1462 for (e = where->callees; e; e = e->next_callee) 1463 if (!e->inline_failed) 1464 lookup_recursive_calls (node, e->callee, heap); 1465 } 1466 1467 /* Decide on recursive inlining: in the case function has recursive calls, 1468 inline until body size reaches given argument. If any new indirect edges 1469 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES 1470 is NULL. */ 1471 1472 static bool 1473 recursive_inlining (struct cgraph_edge *edge, 1474 vec<cgraph_edge *> *new_edges) 1475 { 1476 int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO); 1477 edge_heap_t heap (sreal::min ()); 1478 struct cgraph_node *node; 1479 struct cgraph_edge *e; 1480 struct cgraph_node *master_clone = NULL, *next; 1481 int depth = 0; 1482 int n = 0; 1483 1484 node = edge->caller; 1485 if (node->global.inlined_to) 1486 node = node->global.inlined_to; 1487 1488 if (DECL_DECLARED_INLINE_P (node->decl)) 1489 limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE); 1490 1491 /* Make sure that function is small enough to be considered for inlining. */ 1492 if (estimate_size_after_inlining (node, edge) >= limit) 1493 return false; 1494 lookup_recursive_calls (node, node, &heap); 1495 if (heap.empty ()) 1496 return false; 1497 1498 if (dump_file) 1499 fprintf (dump_file, 1500 " Performing recursive inlining on %s\n", 1501 node->name ()); 1502 1503 /* Do the inlining and update list of recursive call during process. */ 1504 while (!heap.empty ()) 1505 { 1506 struct cgraph_edge *curr = heap.extract_min (); 1507 struct cgraph_node *cnode, *dest = curr->callee; 1508 1509 if (!can_inline_edge_p (curr, true) 1510 || can_inline_edge_by_limits_p (curr, true)) 1511 continue; 1512 1513 /* MASTER_CLONE is produced in the case we already started modified 1514 the function. Be sure to redirect edge to the original body before 1515 estimating growths otherwise we will be seeing growths after inlining 1516 the already modified body. */ 1517 if (master_clone) 1518 { 1519 curr->redirect_callee (master_clone); 1520 if (edge_growth_cache != NULL) 1521 edge_growth_cache->remove (curr); 1522 } 1523 1524 if (estimate_size_after_inlining (node, curr) > limit) 1525 { 1526 curr->redirect_callee (dest); 1527 if (edge_growth_cache != NULL) 1528 edge_growth_cache->remove (curr); 1529 break; 1530 } 1531 1532 depth = 1; 1533 for (cnode = curr->caller; 1534 cnode->global.inlined_to; cnode = cnode->callers->caller) 1535 if (node->decl 1536 == curr->callee->ultimate_alias_target ()->decl) 1537 depth++; 1538 1539 if (!want_inline_self_recursive_call_p (curr, node, false, depth)) 1540 { 1541 curr->redirect_callee (dest); 1542 if (edge_growth_cache != NULL) 1543 edge_growth_cache->remove (curr); 1544 continue; 1545 } 1546 1547 if (dump_file) 1548 { 1549 fprintf (dump_file, 1550 " Inlining call of depth %i", depth); 1551 if (node->count.nonzero_p ()) 1552 { 1553 fprintf (dump_file, " called approx. %.2f times per call", 1554 (double)curr->count.to_gcov_type () 1555 / node->count.to_gcov_type ()); 1556 } 1557 fprintf (dump_file, "\n"); 1558 } 1559 if (!master_clone) 1560 { 1561 /* We need original clone to copy around. */ 1562 master_clone = node->create_clone (node->decl, node->count, 1563 false, vNULL, true, NULL, NULL); 1564 for (e = master_clone->callees; e; e = e->next_callee) 1565 if (!e->inline_failed) 1566 clone_inlined_nodes (e, true, false, NULL); 1567 curr->redirect_callee (master_clone); 1568 if (edge_growth_cache != NULL) 1569 edge_growth_cache->remove (curr); 1570 } 1571 1572 inline_call (curr, false, new_edges, &overall_size, true); 1573 lookup_recursive_calls (node, curr->callee, &heap); 1574 n++; 1575 } 1576 1577 if (!heap.empty () && dump_file) 1578 fprintf (dump_file, " Recursive inlining growth limit met.\n"); 1579 1580 if (!master_clone) 1581 return false; 1582 1583 if (dump_enabled_p ()) 1584 dump_printf_loc (MSG_NOTE, edge->call_stmt, 1585 "\n Inlined %i times, " 1586 "body grown from size %i to %i, time %f to %f\n", n, 1587 ipa_fn_summaries->get (master_clone)->size, 1588 ipa_fn_summaries->get (node)->size, 1589 ipa_fn_summaries->get (master_clone)->time.to_double (), 1590 ipa_fn_summaries->get (node)->time.to_double ()); 1591 1592 /* Remove master clone we used for inlining. We rely that clones inlined 1593 into master clone gets queued just before master clone so we don't 1594 need recursion. */ 1595 for (node = symtab->first_function (); node != master_clone; 1596 node = next) 1597 { 1598 next = symtab->next_function (node); 1599 if (node->global.inlined_to == master_clone) 1600 node->remove (); 1601 } 1602 master_clone->remove (); 1603 return true; 1604 } 1605 1606 1607 /* Given whole compilation unit estimate of INSNS, compute how large we can 1608 allow the unit to grow. */ 1609 1610 static int 1611 compute_max_insns (int insns) 1612 { 1613 int max_insns = insns; 1614 if (max_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS)) 1615 max_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS); 1616 1617 return ((int64_t) max_insns 1618 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100); 1619 } 1620 1621 1622 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */ 1623 1624 static void 1625 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> new_edges) 1626 { 1627 while (new_edges.length () > 0) 1628 { 1629 struct cgraph_edge *edge = new_edges.pop (); 1630 1631 gcc_assert (!edge->aux); 1632 if (edge->inline_failed 1633 && can_inline_edge_p (edge, true) 1634 && want_inline_small_function_p (edge, true) 1635 && can_inline_edge_by_limits_p (edge, true)) 1636 edge->aux = heap->insert (edge_badness (edge, false), edge); 1637 } 1638 } 1639 1640 /* Remove EDGE from the fibheap. */ 1641 1642 static void 1643 heap_edge_removal_hook (struct cgraph_edge *e, void *data) 1644 { 1645 if (e->aux) 1646 { 1647 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux); 1648 e->aux = NULL; 1649 } 1650 } 1651 1652 /* Return true if speculation of edge E seems useful. 1653 If ANTICIPATE_INLINING is true, be conservative and hope that E 1654 may get inlined. */ 1655 1656 bool 1657 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining) 1658 { 1659 enum availability avail; 1660 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail, 1661 e->caller); 1662 struct cgraph_edge *direct, *indirect; 1663 struct ipa_ref *ref; 1664 1665 gcc_assert (e->speculative && !e->indirect_unknown_callee); 1666 1667 if (!e->maybe_hot_p ()) 1668 return false; 1669 1670 /* See if IP optimizations found something potentially useful about the 1671 function. For now we look only for CONST/PURE flags. Almost everything 1672 else we propagate is useless. */ 1673 if (avail >= AVAIL_AVAILABLE) 1674 { 1675 int ecf_flags = flags_from_decl_or_type (target->decl); 1676 if (ecf_flags & ECF_CONST) 1677 { 1678 e->speculative_call_info (direct, indirect, ref); 1679 if (!(indirect->indirect_info->ecf_flags & ECF_CONST)) 1680 return true; 1681 } 1682 else if (ecf_flags & ECF_PURE) 1683 { 1684 e->speculative_call_info (direct, indirect, ref); 1685 if (!(indirect->indirect_info->ecf_flags & ECF_PURE)) 1686 return true; 1687 } 1688 } 1689 /* If we did not managed to inline the function nor redirect 1690 to an ipa-cp clone (that are seen by having local flag set), 1691 it is probably pointless to inline it unless hardware is missing 1692 indirect call predictor. */ 1693 if (!anticipate_inlining && e->inline_failed && !target->local.local) 1694 return false; 1695 /* For overwritable targets there is not much to do. */ 1696 if (e->inline_failed 1697 && (!can_inline_edge_p (e, false) 1698 || !can_inline_edge_by_limits_p (e, false, true))) 1699 return false; 1700 /* OK, speculation seems interesting. */ 1701 return true; 1702 } 1703 1704 /* We know that EDGE is not going to be inlined. 1705 See if we can remove speculation. */ 1706 1707 static void 1708 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge) 1709 { 1710 if (edge->speculative && !speculation_useful_p (edge, false)) 1711 { 1712 struct cgraph_node *node = edge->caller; 1713 struct cgraph_node *where = node->global.inlined_to 1714 ? node->global.inlined_to : node; 1715 auto_bitmap updated_nodes; 1716 1717 if (edge->count.ipa ().initialized_p ()) 1718 spec_rem += edge->count.ipa (); 1719 edge->resolve_speculation (); 1720 reset_edge_caches (where); 1721 ipa_update_overall_fn_summary (where); 1722 update_caller_keys (edge_heap, where, 1723 updated_nodes, NULL); 1724 update_callee_keys (edge_heap, where, 1725 updated_nodes); 1726 } 1727 } 1728 1729 /* Return true if NODE should be accounted for overall size estimate. 1730 Skip all nodes optimized for size so we can measure the growth of hot 1731 part of program no matter of the padding. */ 1732 1733 bool 1734 inline_account_function_p (struct cgraph_node *node) 1735 { 1736 return (!DECL_EXTERNAL (node->decl) 1737 && !opt_for_fn (node->decl, optimize_size) 1738 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED); 1739 } 1740 1741 /* Count number of callers of NODE and store it into DATA (that 1742 points to int. Worker for cgraph_for_node_and_aliases. */ 1743 1744 static bool 1745 sum_callers (struct cgraph_node *node, void *data) 1746 { 1747 struct cgraph_edge *e; 1748 int *num_calls = (int *)data; 1749 1750 for (e = node->callers; e; e = e->next_caller) 1751 (*num_calls)++; 1752 return false; 1753 } 1754 1755 /* We use greedy algorithm for inlining of small functions: 1756 All inline candidates are put into prioritized heap ordered in 1757 increasing badness. 1758 1759 The inlining of small functions is bounded by unit growth parameters. */ 1760 1761 static void 1762 inline_small_functions (void) 1763 { 1764 struct cgraph_node *node; 1765 struct cgraph_edge *edge; 1766 edge_heap_t edge_heap (sreal::min ()); 1767 auto_bitmap updated_nodes; 1768 int min_size, max_size; 1769 auto_vec<cgraph_edge *> new_indirect_edges; 1770 int initial_size = 0; 1771 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count); 1772 struct cgraph_edge_hook_list *edge_removal_hook_holder; 1773 new_indirect_edges.create (8); 1774 1775 edge_removal_hook_holder 1776 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap); 1777 1778 /* Compute overall unit size and other global parameters used by badness 1779 metrics. */ 1780 1781 max_count = profile_count::uninitialized (); 1782 ipa_reduced_postorder (order, true, NULL); 1783 free (order); 1784 1785 FOR_EACH_DEFINED_FUNCTION (node) 1786 if (!node->global.inlined_to) 1787 { 1788 if (!node->alias && node->analyzed 1789 && (node->has_gimple_body_p () || node->thunk.thunk_p) 1790 && opt_for_fn (node->decl, optimize)) 1791 { 1792 struct ipa_fn_summary *info = ipa_fn_summaries->get (node); 1793 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux; 1794 1795 /* Do not account external functions, they will be optimized out 1796 if not inlined. Also only count the non-cold portion of program. */ 1797 if (inline_account_function_p (node)) 1798 initial_size += info->size; 1799 info->growth = estimate_growth (node); 1800 1801 int num_calls = 0; 1802 node->call_for_symbol_and_aliases (sum_callers, &num_calls, 1803 true); 1804 if (num_calls == 1) 1805 info->single_caller = true; 1806 if (dfs && dfs->next_cycle) 1807 { 1808 struct cgraph_node *n2; 1809 int id = dfs->scc_no + 1; 1810 for (n2 = node; n2; 1811 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle) 1812 if (opt_for_fn (n2->decl, optimize)) 1813 { 1814 ipa_fn_summary *info2 = ipa_fn_summaries->get (n2); 1815 if (info2->scc_no) 1816 break; 1817 info2->scc_no = id; 1818 } 1819 } 1820 } 1821 1822 for (edge = node->callers; edge; edge = edge->next_caller) 1823 max_count = max_count.max (edge->count.ipa ()); 1824 } 1825 ipa_free_postorder_info (); 1826 edge_growth_cache 1827 = new call_summary<edge_growth_cache_entry *> (symtab, false); 1828 1829 if (dump_file) 1830 fprintf (dump_file, 1831 "\nDeciding on inlining of small functions. Starting with size %i.\n", 1832 initial_size); 1833 1834 overall_size = initial_size; 1835 max_size = compute_max_insns (overall_size); 1836 min_size = overall_size; 1837 1838 /* Populate the heap with all edges we might inline. */ 1839 1840 FOR_EACH_DEFINED_FUNCTION (node) 1841 { 1842 bool update = false; 1843 struct cgraph_edge *next = NULL; 1844 bool has_speculative = false; 1845 1846 if (!opt_for_fn (node->decl, optimize)) 1847 continue; 1848 1849 if (dump_file) 1850 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ()); 1851 1852 for (edge = node->callees; edge; edge = next) 1853 { 1854 next = edge->next_callee; 1855 if (edge->inline_failed 1856 && !edge->aux 1857 && can_inline_edge_p (edge, true) 1858 && want_inline_small_function_p (edge, true) 1859 && can_inline_edge_by_limits_p (edge, true) 1860 && edge->inline_failed) 1861 { 1862 gcc_assert (!edge->aux); 1863 update_edge_key (&edge_heap, edge); 1864 } 1865 if (edge->speculative) 1866 has_speculative = true; 1867 } 1868 if (has_speculative) 1869 for (edge = node->callees; edge; edge = next) 1870 if (edge->speculative && !speculation_useful_p (edge, 1871 edge->aux != NULL)) 1872 { 1873 edge->resolve_speculation (); 1874 update = true; 1875 } 1876 if (update) 1877 { 1878 struct cgraph_node *where = node->global.inlined_to 1879 ? node->global.inlined_to : node; 1880 ipa_update_overall_fn_summary (where); 1881 reset_edge_caches (where); 1882 update_caller_keys (&edge_heap, where, 1883 updated_nodes, NULL); 1884 update_callee_keys (&edge_heap, where, 1885 updated_nodes); 1886 bitmap_clear (updated_nodes); 1887 } 1888 } 1889 1890 gcc_assert (in_lto_p 1891 || !(max_count > 0) 1892 || (profile_info && flag_branch_probabilities)); 1893 1894 while (!edge_heap.empty ()) 1895 { 1896 int old_size = overall_size; 1897 struct cgraph_node *where, *callee; 1898 sreal badness = edge_heap.min_key (); 1899 sreal current_badness; 1900 int growth; 1901 1902 edge = edge_heap.extract_min (); 1903 gcc_assert (edge->aux); 1904 edge->aux = NULL; 1905 if (!edge->inline_failed || !edge->callee->analyzed) 1906 continue; 1907 1908 #if CHECKING_P 1909 /* Be sure that caches are maintained consistent. 1910 This check is affected by scaling roundoff errors when compiling for 1911 IPA this we skip it in that case. */ 1912 if (!edge->callee->count.ipa_p () 1913 && (!max_count.initialized_p () || !max_count.nonzero_p ())) 1914 { 1915 sreal cached_badness = edge_badness (edge, false); 1916 1917 int old_size_est = estimate_edge_size (edge); 1918 sreal old_time_est = estimate_edge_time (edge); 1919 int old_hints_est = estimate_edge_hints (edge); 1920 1921 if (edge_growth_cache != NULL) 1922 edge_growth_cache->remove (edge); 1923 gcc_assert (old_size_est == estimate_edge_size (edge)); 1924 gcc_assert (old_time_est == estimate_edge_time (edge)); 1925 /* FIXME: 1926 1927 gcc_assert (old_hints_est == estimate_edge_hints (edge)); 1928 1929 fails with profile feedback because some hints depends on 1930 maybe_hot_edge_p predicate and because callee gets inlined to other 1931 calls, the edge may become cold. 1932 This ought to be fixed by computing relative probabilities 1933 for given invocation but that will be better done once whole 1934 code is converted to sreals. Disable for now and revert to "wrong" 1935 value so enable/disable checking paths agree. */ 1936 edge_growth_cache->get (edge)->hints = old_hints_est + 1; 1937 1938 /* When updating the edge costs, we only decrease badness in the keys. 1939 Increases of badness are handled lazilly; when we see key with out 1940 of date value on it, we re-insert it now. */ 1941 current_badness = edge_badness (edge, false); 1942 gcc_assert (cached_badness == current_badness); 1943 gcc_assert (current_badness >= badness); 1944 } 1945 else 1946 current_badness = edge_badness (edge, false); 1947 #else 1948 current_badness = edge_badness (edge, false); 1949 #endif 1950 if (current_badness != badness) 1951 { 1952 if (edge_heap.min () && current_badness > edge_heap.min_key ()) 1953 { 1954 edge->aux = edge_heap.insert (current_badness, edge); 1955 continue; 1956 } 1957 else 1958 badness = current_badness; 1959 } 1960 1961 if (!can_inline_edge_p (edge, true) 1962 || !can_inline_edge_by_limits_p (edge, true)) 1963 { 1964 resolve_noninline_speculation (&edge_heap, edge); 1965 continue; 1966 } 1967 1968 callee = edge->callee->ultimate_alias_target (); 1969 growth = estimate_edge_growth (edge); 1970 if (dump_file) 1971 { 1972 fprintf (dump_file, 1973 "\nConsidering %s with %i size\n", 1974 callee->dump_name (), 1975 ipa_fn_summaries->get (callee)->size); 1976 fprintf (dump_file, 1977 " to be inlined into %s in %s:%i\n" 1978 " Estimated badness is %f, frequency %.2f.\n", 1979 edge->caller->dump_name (), 1980 edge->call_stmt 1981 && (LOCATION_LOCUS (gimple_location ((const gimple *) 1982 edge->call_stmt)) 1983 > BUILTINS_LOCATION) 1984 ? gimple_filename ((const gimple *) edge->call_stmt) 1985 : "unknown", 1986 edge->call_stmt 1987 ? gimple_lineno ((const gimple *) edge->call_stmt) 1988 : -1, 1989 badness.to_double (), 1990 edge->sreal_frequency ().to_double ()); 1991 if (edge->count.ipa ().initialized_p ()) 1992 { 1993 fprintf (dump_file, " Called "); 1994 edge->count.ipa ().dump (dump_file); 1995 fprintf (dump_file, " times\n"); 1996 } 1997 if (dump_flags & TDF_DETAILS) 1998 edge_badness (edge, true); 1999 } 2000 2001 if (overall_size + growth > max_size 2002 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl)) 2003 { 2004 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT; 2005 report_inline_failed_reason (edge); 2006 resolve_noninline_speculation (&edge_heap, edge); 2007 continue; 2008 } 2009 2010 if (!want_inline_small_function_p (edge, true)) 2011 { 2012 resolve_noninline_speculation (&edge_heap, edge); 2013 continue; 2014 } 2015 2016 /* Heuristics for inlining small functions work poorly for 2017 recursive calls where we do effects similar to loop unrolling. 2018 When inlining such edge seems profitable, leave decision on 2019 specific inliner. */ 2020 if (edge->recursive_p ()) 2021 { 2022 where = edge->caller; 2023 if (where->global.inlined_to) 2024 where = where->global.inlined_to; 2025 if (!recursive_inlining (edge, 2026 opt_for_fn (edge->caller->decl, 2027 flag_indirect_inlining) 2028 ? &new_indirect_edges : NULL)) 2029 { 2030 edge->inline_failed = CIF_RECURSIVE_INLINING; 2031 resolve_noninline_speculation (&edge_heap, edge); 2032 continue; 2033 } 2034 reset_edge_caches (where); 2035 /* Recursive inliner inlines all recursive calls of the function 2036 at once. Consequently we need to update all callee keys. */ 2037 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining)) 2038 add_new_edges_to_heap (&edge_heap, new_indirect_edges); 2039 update_callee_keys (&edge_heap, where, updated_nodes); 2040 bitmap_clear (updated_nodes); 2041 } 2042 else 2043 { 2044 struct cgraph_node *outer_node = NULL; 2045 int depth = 0; 2046 2047 /* Consider the case where self recursive function A is inlined 2048 into B. This is desired optimization in some cases, since it 2049 leads to effect similar of loop peeling and we might completely 2050 optimize out the recursive call. However we must be extra 2051 selective. */ 2052 2053 where = edge->caller; 2054 while (where->global.inlined_to) 2055 { 2056 if (where->decl == callee->decl) 2057 outer_node = where, depth++; 2058 where = where->callers->caller; 2059 } 2060 if (outer_node 2061 && !want_inline_self_recursive_call_p (edge, outer_node, 2062 true, depth)) 2063 { 2064 edge->inline_failed 2065 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl) 2066 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED); 2067 resolve_noninline_speculation (&edge_heap, edge); 2068 continue; 2069 } 2070 else if (depth && dump_file) 2071 fprintf (dump_file, " Peeling recursion with depth %i\n", depth); 2072 2073 gcc_checking_assert (!callee->global.inlined_to); 2074 inline_call (edge, true, &new_indirect_edges, &overall_size, true); 2075 add_new_edges_to_heap (&edge_heap, new_indirect_edges); 2076 2077 reset_edge_caches (edge->callee); 2078 2079 update_callee_keys (&edge_heap, where, updated_nodes); 2080 } 2081 where = edge->caller; 2082 if (where->global.inlined_to) 2083 where = where->global.inlined_to; 2084 2085 /* Our profitability metric can depend on local properties 2086 such as number of inlinable calls and size of the function body. 2087 After inlining these properties might change for the function we 2088 inlined into (since it's body size changed) and for the functions 2089 called by function we inlined (since number of it inlinable callers 2090 might change). */ 2091 update_caller_keys (&edge_heap, where, updated_nodes, NULL); 2092 /* Offline copy count has possibly changed, recompute if profile is 2093 available. */ 2094 struct cgraph_node *n = cgraph_node::get (edge->callee->decl); 2095 if (n != edge->callee && n->analyzed && n->count.ipa ().initialized_p ()) 2096 update_callee_keys (&edge_heap, n, updated_nodes); 2097 bitmap_clear (updated_nodes); 2098 2099 if (dump_enabled_p ()) 2100 { 2101 ipa_fn_summary *s = ipa_fn_summaries->get (edge->caller); 2102 2103 /* dump_printf can't handle %+i. */ 2104 char buf_net_change[100]; 2105 snprintf (buf_net_change, sizeof buf_net_change, "%+i", 2106 overall_size - old_size); 2107 2108 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt, 2109 " Inlined %C into %C which now has time %f and " 2110 "size %i, net change of %s.\n", 2111 edge->callee, edge->caller, 2112 s->time.to_double (), s->size, buf_net_change); 2113 } 2114 if (min_size > overall_size) 2115 { 2116 min_size = overall_size; 2117 max_size = compute_max_insns (min_size); 2118 2119 if (dump_file) 2120 fprintf (dump_file, "New minimal size reached: %i\n", min_size); 2121 } 2122 } 2123 2124 free_growth_caches (); 2125 if (dump_enabled_p ()) 2126 dump_printf (MSG_NOTE, 2127 "Unit growth for small function inlining: %i->%i (%i%%)\n", 2128 initial_size, overall_size, 2129 initial_size ? overall_size * 100 / (initial_size) - 100: 0); 2130 symtab->remove_edge_removal_hook (edge_removal_hook_holder); 2131 } 2132 2133 /* Flatten NODE. Performed both during early inlining and 2134 at IPA inlining time. */ 2135 2136 static void 2137 flatten_function (struct cgraph_node *node, bool early, bool update) 2138 { 2139 struct cgraph_edge *e; 2140 2141 /* We shouldn't be called recursively when we are being processed. */ 2142 gcc_assert (node->aux == NULL); 2143 2144 node->aux = (void *) node; 2145 2146 for (e = node->callees; e; e = e->next_callee) 2147 { 2148 struct cgraph_node *orig_callee; 2149 struct cgraph_node *callee = e->callee->ultimate_alias_target (); 2150 2151 /* We've hit cycle? It is time to give up. */ 2152 if (callee->aux) 2153 { 2154 if (dump_enabled_p ()) 2155 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 2156 "Not inlining %C into %C to avoid cycle.\n", 2157 callee, e->caller); 2158 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR) 2159 e->inline_failed = CIF_RECURSIVE_INLINING; 2160 continue; 2161 } 2162 2163 /* When the edge is already inlined, we just need to recurse into 2164 it in order to fully flatten the leaves. */ 2165 if (!e->inline_failed) 2166 { 2167 flatten_function (callee, early, false); 2168 continue; 2169 } 2170 2171 /* Flatten attribute needs to be processed during late inlining. For 2172 extra code quality we however do flattening during early optimization, 2173 too. */ 2174 if (!early 2175 ? !can_inline_edge_p (e, true) 2176 && !can_inline_edge_by_limits_p (e, true) 2177 : !can_early_inline_edge_p (e)) 2178 continue; 2179 2180 if (e->recursive_p ()) 2181 { 2182 if (dump_enabled_p ()) 2183 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 2184 "Not inlining: recursive call.\n"); 2185 continue; 2186 } 2187 2188 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl)) 2189 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl))) 2190 { 2191 if (dump_enabled_p ()) 2192 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 2193 "Not inlining: SSA form does not match.\n"); 2194 continue; 2195 } 2196 2197 /* Inline the edge and flatten the inline clone. Avoid 2198 recursing through the original node if the node was cloned. */ 2199 if (dump_enabled_p ()) 2200 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt, 2201 " Inlining %C into %C.\n", 2202 callee, e->caller); 2203 orig_callee = callee; 2204 inline_call (e, true, NULL, NULL, false); 2205 if (e->callee != orig_callee) 2206 orig_callee->aux = (void *) node; 2207 flatten_function (e->callee, early, false); 2208 if (e->callee != orig_callee) 2209 orig_callee->aux = NULL; 2210 } 2211 2212 node->aux = NULL; 2213 if (update) 2214 ipa_update_overall_fn_summary (node->global.inlined_to 2215 ? node->global.inlined_to : node); 2216 } 2217 2218 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases. 2219 DATA points to number of calls originally found so we avoid infinite 2220 recursion. */ 2221 2222 static bool 2223 inline_to_all_callers_1 (struct cgraph_node *node, void *data, 2224 hash_set<cgraph_node *> *callers) 2225 { 2226 int *num_calls = (int *)data; 2227 bool callee_removed = false; 2228 2229 while (node->callers && !node->global.inlined_to) 2230 { 2231 struct cgraph_node *caller = node->callers->caller; 2232 2233 if (!can_inline_edge_p (node->callers, true) 2234 || !can_inline_edge_by_limits_p (node->callers, true) 2235 || node->callers->recursive_p ()) 2236 { 2237 if (dump_file) 2238 fprintf (dump_file, "Uninlinable call found; giving up.\n"); 2239 *num_calls = 0; 2240 return false; 2241 } 2242 2243 if (dump_file) 2244 { 2245 cgraph_node *ultimate = node->ultimate_alias_target (); 2246 fprintf (dump_file, 2247 "\nInlining %s size %i.\n", 2248 ultimate->name (), 2249 ipa_fn_summaries->get (ultimate)->size); 2250 fprintf (dump_file, 2251 " Called once from %s %i insns.\n", 2252 node->callers->caller->name (), 2253 ipa_fn_summaries->get (node->callers->caller)->size); 2254 } 2255 2256 /* Remember which callers we inlined to, delaying updating the 2257 overall summary. */ 2258 callers->add (node->callers->caller); 2259 inline_call (node->callers, true, NULL, NULL, false, &callee_removed); 2260 if (dump_file) 2261 fprintf (dump_file, 2262 " Inlined into %s which now has %i size\n", 2263 caller->name (), 2264 ipa_fn_summaries->get (caller)->size); 2265 if (!(*num_calls)--) 2266 { 2267 if (dump_file) 2268 fprintf (dump_file, "New calls found; giving up.\n"); 2269 return callee_removed; 2270 } 2271 if (callee_removed) 2272 return true; 2273 } 2274 return false; 2275 } 2276 2277 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary 2278 update. */ 2279 2280 static bool 2281 inline_to_all_callers (struct cgraph_node *node, void *data) 2282 { 2283 hash_set<cgraph_node *> callers; 2284 bool res = inline_to_all_callers_1 (node, data, &callers); 2285 /* Perform the delayed update of the overall summary of all callers 2286 processed. This avoids quadratic behavior in the cases where 2287 we have a lot of calls to the same function. */ 2288 for (hash_set<cgraph_node *>::iterator i = callers.begin (); 2289 i != callers.end (); ++i) 2290 ipa_update_overall_fn_summary (*i); 2291 return res; 2292 } 2293 2294 /* Output overall time estimate. */ 2295 static void 2296 dump_overall_stats (void) 2297 { 2298 sreal sum_weighted = 0, sum = 0; 2299 struct cgraph_node *node; 2300 2301 FOR_EACH_DEFINED_FUNCTION (node) 2302 if (!node->global.inlined_to 2303 && !node->alias) 2304 { 2305 ipa_fn_summary *s = ipa_fn_summaries->get (node); 2306 if (s != NULL) 2307 { 2308 sum += s->time; 2309 if (node->count.ipa ().initialized_p ()) 2310 sum_weighted += s->time * node->count.ipa ().to_gcov_type (); 2311 } 2312 } 2313 fprintf (dump_file, "Overall time estimate: " 2314 "%f weighted by profile: " 2315 "%f\n", sum.to_double (), sum_weighted.to_double ()); 2316 } 2317 2318 /* Output some useful stats about inlining. */ 2319 2320 static void 2321 dump_inline_stats (void) 2322 { 2323 int64_t inlined_cnt = 0, inlined_indir_cnt = 0; 2324 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0; 2325 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0; 2326 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0; 2327 int64_t inlined_speculative = 0, inlined_speculative_ply = 0; 2328 int64_t indirect_poly_cnt = 0, indirect_cnt = 0; 2329 int64_t reason[CIF_N_REASONS][2]; 2330 sreal reason_freq[CIF_N_REASONS]; 2331 int i; 2332 struct cgraph_node *node; 2333 2334 memset (reason, 0, sizeof (reason)); 2335 for (i=0; i < CIF_N_REASONS; i++) 2336 reason_freq[i] = 0; 2337 FOR_EACH_DEFINED_FUNCTION (node) 2338 { 2339 struct cgraph_edge *e; 2340 for (e = node->callees; e; e = e->next_callee) 2341 { 2342 if (e->inline_failed) 2343 { 2344 if (e->count.ipa ().initialized_p ()) 2345 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type (); 2346 reason_freq[(int) e->inline_failed] += e->sreal_frequency (); 2347 reason[(int) e->inline_failed][1] ++; 2348 if (DECL_VIRTUAL_P (e->callee->decl) 2349 && e->count.ipa ().initialized_p ()) 2350 { 2351 if (e->indirect_inlining_edge) 2352 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type (); 2353 else 2354 noninlined_virt_cnt += e->count.ipa ().to_gcov_type (); 2355 } 2356 else if (e->count.ipa ().initialized_p ()) 2357 { 2358 if (e->indirect_inlining_edge) 2359 noninlined_indir_cnt += e->count.ipa ().to_gcov_type (); 2360 else 2361 noninlined_cnt += e->count.ipa ().to_gcov_type (); 2362 } 2363 } 2364 else if (e->count.ipa ().initialized_p ()) 2365 { 2366 if (e->speculative) 2367 { 2368 if (DECL_VIRTUAL_P (e->callee->decl)) 2369 inlined_speculative_ply += e->count.ipa ().to_gcov_type (); 2370 else 2371 inlined_speculative += e->count.ipa ().to_gcov_type (); 2372 } 2373 else if (DECL_VIRTUAL_P (e->callee->decl)) 2374 { 2375 if (e->indirect_inlining_edge) 2376 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type (); 2377 else 2378 inlined_virt_cnt += e->count.ipa ().to_gcov_type (); 2379 } 2380 else 2381 { 2382 if (e->indirect_inlining_edge) 2383 inlined_indir_cnt += e->count.ipa ().to_gcov_type (); 2384 else 2385 inlined_cnt += e->count.ipa ().to_gcov_type (); 2386 } 2387 } 2388 } 2389 for (e = node->indirect_calls; e; e = e->next_callee) 2390 if (e->indirect_info->polymorphic 2391 & e->count.ipa ().initialized_p ()) 2392 indirect_poly_cnt += e->count.ipa ().to_gcov_type (); 2393 else if (e->count.ipa ().initialized_p ()) 2394 indirect_cnt += e->count.ipa ().to_gcov_type (); 2395 } 2396 if (max_count.initialized_p ()) 2397 { 2398 fprintf (dump_file, 2399 "Inlined %" PRId64 " + speculative " 2400 "%" PRId64 " + speculative polymorphic " 2401 "%" PRId64 " + previously indirect " 2402 "%" PRId64 " + virtual " 2403 "%" PRId64 " + virtual and previously indirect " 2404 "%" PRId64 "\n" "Not inlined " 2405 "%" PRId64 " + previously indirect " 2406 "%" PRId64 " + virtual " 2407 "%" PRId64 " + virtual and previously indirect " 2408 "%" PRId64 " + stil indirect " 2409 "%" PRId64 " + still indirect polymorphic " 2410 "%" PRId64 "\n", inlined_cnt, 2411 inlined_speculative, inlined_speculative_ply, 2412 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt, 2413 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt, 2414 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt); 2415 fprintf (dump_file, "Removed speculations "); 2416 spec_rem.dump (dump_file); 2417 fprintf (dump_file, "\n"); 2418 } 2419 dump_overall_stats (); 2420 fprintf (dump_file, "\nWhy inlining failed?\n"); 2421 for (i = 0; i < CIF_N_REASONS; i++) 2422 if (reason[i][1]) 2423 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n", 2424 cgraph_inline_failed_string ((cgraph_inline_failed_t) i), 2425 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]); 2426 } 2427 2428 /* Called when node is removed. */ 2429 2430 static void 2431 flatten_remove_node_hook (struct cgraph_node *node, void *data) 2432 { 2433 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL) 2434 return; 2435 2436 hash_set<struct cgraph_node *> *removed 2437 = (hash_set<struct cgraph_node *> *) data; 2438 removed->add (node); 2439 } 2440 2441 /* Decide on the inlining. We do so in the topological order to avoid 2442 expenses on updating data structures. */ 2443 2444 static unsigned int 2445 ipa_inline (void) 2446 { 2447 struct cgraph_node *node; 2448 int nnodes; 2449 struct cgraph_node **order; 2450 int i, j; 2451 int cold; 2452 bool remove_functions = false; 2453 2454 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); 2455 2456 if (dump_file) 2457 ipa_dump_fn_summaries (dump_file); 2458 2459 nnodes = ipa_reverse_postorder (order); 2460 spec_rem = profile_count::zero (); 2461 2462 FOR_EACH_FUNCTION (node) 2463 { 2464 node->aux = 0; 2465 2466 /* Recompute the default reasons for inlining because they may have 2467 changed during merging. */ 2468 if (in_lto_p) 2469 { 2470 for (cgraph_edge *e = node->callees; e; e = e->next_callee) 2471 { 2472 gcc_assert (e->inline_failed); 2473 initialize_inline_failed (e); 2474 } 2475 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) 2476 initialize_inline_failed (e); 2477 } 2478 } 2479 2480 if (dump_file) 2481 fprintf (dump_file, "\nFlattening functions:\n"); 2482 2483 /* First shrink order array, so that it only contains nodes with 2484 flatten attribute. */ 2485 for (i = nnodes - 1, j = i; i >= 0; i--) 2486 { 2487 node = order[i]; 2488 if (lookup_attribute ("flatten", 2489 DECL_ATTRIBUTES (node->decl)) != NULL) 2490 order[j--] = order[i]; 2491 } 2492 2493 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain 2494 nodes with flatten attribute. If there is more than one such 2495 node, we need to register a node removal hook, as flatten_function 2496 could remove other nodes with flatten attribute. See PR82801. */ 2497 struct cgraph_node_hook_list *node_removal_hook_holder = NULL; 2498 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL; 2499 /* 2500 * XXXMRG: added "nnodes > 1" as -O2 (but not -O) warn: 2501 * "assuming signed overflow does not occur" 2502 */ 2503 if (nnodes > 1 && j < nnodes - 2) 2504 { 2505 flatten_removed_nodes = new hash_set<struct cgraph_node *>; 2506 node_removal_hook_holder 2507 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook, 2508 flatten_removed_nodes); 2509 } 2510 2511 /* In the first pass handle functions to be flattened. Do this with 2512 a priority so none of our later choices will make this impossible. */ 2513 for (i = nnodes - 1; i > j; i--) 2514 { 2515 node = order[i]; 2516 if (flatten_removed_nodes 2517 && flatten_removed_nodes->contains (node)) 2518 continue; 2519 2520 /* Handle nodes to be flattened. 2521 Ideally when processing callees we stop inlining at the 2522 entry of cycles, possibly cloning that entry point and 2523 try to flatten itself turning it into a self-recursive 2524 function. */ 2525 if (dump_file) 2526 fprintf (dump_file, "Flattening %s\n", node->name ()); 2527 flatten_function (node, false, true); 2528 } 2529 2530 if (j < nnodes - 2) 2531 { 2532 symtab->remove_cgraph_removal_hook (node_removal_hook_holder); 2533 delete flatten_removed_nodes; 2534 } 2535 free (order); 2536 2537 if (dump_file) 2538 dump_overall_stats (); 2539 2540 inline_small_functions (); 2541 2542 gcc_assert (symtab->state == IPA_SSA); 2543 symtab->state = IPA_SSA_AFTER_INLINING; 2544 /* Do first after-inlining removal. We want to remove all "stale" extern 2545 inline functions and virtual functions so we really know what is called 2546 once. */ 2547 symtab->remove_unreachable_nodes (dump_file); 2548 2549 /* Inline functions with a property that after inlining into all callers the 2550 code size will shrink because the out-of-line copy is eliminated. 2551 We do this regardless on the callee size as long as function growth limits 2552 are met. */ 2553 if (dump_file) 2554 fprintf (dump_file, 2555 "\nDeciding on functions to be inlined into all callers and " 2556 "removing useless speculations:\n"); 2557 2558 /* Inlining one function called once has good chance of preventing 2559 inlining other function into the same callee. Ideally we should 2560 work in priority order, but probably inlining hot functions first 2561 is good cut without the extra pain of maintaining the queue. 2562 2563 ??? this is not really fitting the bill perfectly: inlining function 2564 into callee often leads to better optimization of callee due to 2565 increased context for optimization. 2566 For example if main() function calls a function that outputs help 2567 and then function that does the main optmization, we should inline 2568 the second with priority even if both calls are cold by themselves. 2569 2570 We probably want to implement new predicate replacing our use of 2571 maybe_hot_edge interpreted as maybe_hot_edge || callee is known 2572 to be hot. */ 2573 for (cold = 0; cold <= 1; cold ++) 2574 { 2575 FOR_EACH_DEFINED_FUNCTION (node) 2576 { 2577 struct cgraph_edge *edge, *next; 2578 bool update=false; 2579 2580 if (!opt_for_fn (node->decl, optimize) 2581 || !opt_for_fn (node->decl, flag_inline_functions_called_once)) 2582 continue; 2583 2584 for (edge = node->callees; edge; edge = next) 2585 { 2586 next = edge->next_callee; 2587 if (edge->speculative && !speculation_useful_p (edge, false)) 2588 { 2589 if (edge->count.ipa ().initialized_p ()) 2590 spec_rem += edge->count.ipa (); 2591 edge->resolve_speculation (); 2592 update = true; 2593 remove_functions = true; 2594 } 2595 } 2596 if (update) 2597 { 2598 struct cgraph_node *where = node->global.inlined_to 2599 ? node->global.inlined_to : node; 2600 reset_edge_caches (where); 2601 ipa_update_overall_fn_summary (where); 2602 } 2603 if (want_inline_function_to_all_callers_p (node, cold)) 2604 { 2605 int num_calls = 0; 2606 node->call_for_symbol_and_aliases (sum_callers, &num_calls, 2607 true); 2608 while (node->call_for_symbol_and_aliases 2609 (inline_to_all_callers, &num_calls, true)) 2610 ; 2611 remove_functions = true; 2612 } 2613 } 2614 } 2615 2616 /* Free ipa-prop structures if they are no longer needed. */ 2617 ipa_free_all_structures_after_iinln (); 2618 2619 if (dump_enabled_p ()) 2620 dump_printf (MSG_NOTE, 2621 "\nInlined %i calls, eliminated %i functions\n\n", 2622 ncalls_inlined, nfunctions_inlined); 2623 if (dump_file) 2624 dump_inline_stats (); 2625 2626 if (dump_file) 2627 ipa_dump_fn_summaries (dump_file); 2628 return remove_functions ? TODO_remove_functions : 0; 2629 } 2630 2631 /* Inline always-inline function calls in NODE. */ 2632 2633 static bool 2634 inline_always_inline_functions (struct cgraph_node *node) 2635 { 2636 struct cgraph_edge *e; 2637 bool inlined = false; 2638 2639 for (e = node->callees; e; e = e->next_callee) 2640 { 2641 struct cgraph_node *callee = e->callee->ultimate_alias_target (); 2642 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)) 2643 continue; 2644 2645 if (e->recursive_p ()) 2646 { 2647 if (dump_enabled_p ()) 2648 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 2649 " Not inlining recursive call to %C.\n", 2650 e->callee); 2651 e->inline_failed = CIF_RECURSIVE_INLINING; 2652 continue; 2653 } 2654 2655 if (!can_early_inline_edge_p (e)) 2656 { 2657 /* Set inlined to true if the callee is marked "always_inline" but 2658 is not inlinable. This will allow flagging an error later in 2659 expand_call_inline in tree-inline.c. */ 2660 if (lookup_attribute ("always_inline", 2661 DECL_ATTRIBUTES (callee->decl)) != NULL) 2662 inlined = true; 2663 continue; 2664 } 2665 2666 if (dump_enabled_p ()) 2667 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt, 2668 " Inlining %C into %C (always_inline).\n", 2669 e->callee, e->caller); 2670 inline_call (e, true, NULL, NULL, false); 2671 inlined = true; 2672 } 2673 if (inlined) 2674 ipa_update_overall_fn_summary (node); 2675 2676 return inlined; 2677 } 2678 2679 /* Decide on the inlining. We do so in the topological order to avoid 2680 expenses on updating data structures. */ 2681 2682 static bool 2683 early_inline_small_functions (struct cgraph_node *node) 2684 { 2685 struct cgraph_edge *e; 2686 bool inlined = false; 2687 2688 for (e = node->callees; e; e = e->next_callee) 2689 { 2690 struct cgraph_node *callee = e->callee->ultimate_alias_target (); 2691 2692 /* We can enounter not-yet-analyzed function during 2693 early inlining on callgraphs with strongly 2694 connected components. */ 2695 ipa_fn_summary *s = ipa_fn_summaries->get (callee); 2696 if (s == NULL || !s->inlinable || !e->inline_failed) 2697 continue; 2698 2699 /* Do not consider functions not declared inline. */ 2700 if (!DECL_DECLARED_INLINE_P (callee->decl) 2701 && !opt_for_fn (node->decl, flag_inline_small_functions) 2702 && !opt_for_fn (node->decl, flag_inline_functions)) 2703 continue; 2704 2705 if (dump_enabled_p ()) 2706 dump_printf_loc (MSG_NOTE, e->call_stmt, 2707 "Considering inline candidate %C.\n", 2708 callee); 2709 2710 if (!can_early_inline_edge_p (e)) 2711 continue; 2712 2713 if (e->recursive_p ()) 2714 { 2715 if (dump_enabled_p ()) 2716 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, 2717 " Not inlining: recursive call.\n"); 2718 continue; 2719 } 2720 2721 if (!want_early_inline_function_p (e)) 2722 continue; 2723 2724 if (dump_enabled_p ()) 2725 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt, 2726 " Inlining %C into %C.\n", 2727 callee, e->caller); 2728 inline_call (e, true, NULL, NULL, false); 2729 inlined = true; 2730 } 2731 2732 if (inlined) 2733 ipa_update_overall_fn_summary (node); 2734 2735 return inlined; 2736 } 2737 2738 unsigned int 2739 early_inliner (function *fun) 2740 { 2741 struct cgraph_node *node = cgraph_node::get (current_function_decl); 2742 struct cgraph_edge *edge; 2743 unsigned int todo = 0; 2744 int iterations = 0; 2745 bool inlined = false; 2746 2747 if (seen_error ()) 2748 return 0; 2749 2750 /* Do nothing if datastructures for ipa-inliner are already computed. This 2751 happens when some pass decides to construct new function and 2752 cgraph_add_new_function calls lowering passes and early optimization on 2753 it. This may confuse ourself when early inliner decide to inline call to 2754 function clone, because function clones don't have parameter list in 2755 ipa-prop matching their signature. */ 2756 if (ipa_node_params_sum) 2757 return 0; 2758 2759 if (flag_checking) 2760 node->verify (); 2761 node->remove_all_references (); 2762 2763 /* Even when not optimizing or not inlining inline always-inline 2764 functions. */ 2765 inlined = inline_always_inline_functions (node); 2766 2767 if (!optimize 2768 || flag_no_inline 2769 || !flag_early_inlining 2770 /* Never inline regular functions into always-inline functions 2771 during incremental inlining. This sucks as functions calling 2772 always inline functions will get less optimized, but at the 2773 same time inlining of functions calling always inline 2774 function into an always inline function might introduce 2775 cycles of edges to be always inlined in the callgraph. 2776 2777 We might want to be smarter and just avoid this type of inlining. */ 2778 || (DECL_DISREGARD_INLINE_LIMITS (node->decl) 2779 && lookup_attribute ("always_inline", 2780 DECL_ATTRIBUTES (node->decl)))) 2781 ; 2782 else if (lookup_attribute ("flatten", 2783 DECL_ATTRIBUTES (node->decl)) != NULL) 2784 { 2785 /* When the function is marked to be flattened, recursively inline 2786 all calls in it. */ 2787 if (dump_enabled_p ()) 2788 dump_printf (MSG_OPTIMIZED_LOCATIONS, 2789 "Flattening %C\n", node); 2790 flatten_function (node, true, true); 2791 inlined = true; 2792 } 2793 else 2794 { 2795 /* If some always_inline functions was inlined, apply the changes. 2796 This way we will not account always inline into growth limits and 2797 moreover we will inline calls from always inlines that we skipped 2798 previously because of conditional above. */ 2799 if (inlined) 2800 { 2801 timevar_push (TV_INTEGRATION); 2802 todo |= optimize_inline_calls (current_function_decl); 2803 /* optimize_inline_calls call above might have introduced new 2804 statements that don't have inline parameters computed. */ 2805 for (edge = node->callees; edge; edge = edge->next_callee) 2806 { 2807 /* We can enounter not-yet-analyzed function during 2808 early inlining on callgraphs with strongly 2809 connected components. */ 2810 ipa_call_summary *es = ipa_call_summaries->get_create (edge); 2811 es->call_stmt_size 2812 = estimate_num_insns (edge->call_stmt, &eni_size_weights); 2813 es->call_stmt_time 2814 = estimate_num_insns (edge->call_stmt, &eni_time_weights); 2815 } 2816 ipa_update_overall_fn_summary (node); 2817 inlined = false; 2818 timevar_pop (TV_INTEGRATION); 2819 } 2820 /* We iterate incremental inlining to get trivial cases of indirect 2821 inlining. */ 2822 while (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS) 2823 && early_inline_small_functions (node)) 2824 { 2825 timevar_push (TV_INTEGRATION); 2826 todo |= optimize_inline_calls (current_function_decl); 2827 2828 /* Technically we ought to recompute inline parameters so the new 2829 iteration of early inliner works as expected. We however have 2830 values approximately right and thus we only need to update edge 2831 info that might be cleared out for newly discovered edges. */ 2832 for (edge = node->callees; edge; edge = edge->next_callee) 2833 { 2834 /* We have no summary for new bound store calls yet. */ 2835 ipa_call_summary *es = ipa_call_summaries->get_create (edge); 2836 es->call_stmt_size 2837 = estimate_num_insns (edge->call_stmt, &eni_size_weights); 2838 es->call_stmt_time 2839 = estimate_num_insns (edge->call_stmt, &eni_time_weights); 2840 2841 if (edge->callee->decl 2842 && !gimple_check_call_matching_types ( 2843 edge->call_stmt, edge->callee->decl, false)) 2844 { 2845 edge->inline_failed = CIF_MISMATCHED_ARGUMENTS; 2846 edge->call_stmt_cannot_inline_p = true; 2847 } 2848 } 2849 if (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS) - 1) 2850 ipa_update_overall_fn_summary (node); 2851 timevar_pop (TV_INTEGRATION); 2852 iterations++; 2853 inlined = false; 2854 } 2855 if (dump_file) 2856 fprintf (dump_file, "Iterations: %i\n", iterations); 2857 } 2858 2859 if (inlined) 2860 { 2861 timevar_push (TV_INTEGRATION); 2862 todo |= optimize_inline_calls (current_function_decl); 2863 timevar_pop (TV_INTEGRATION); 2864 } 2865 2866 fun->always_inline_functions_inlined = true; 2867 2868 return todo; 2869 } 2870 2871 /* Do inlining of small functions. Doing so early helps profiling and other 2872 passes to be somewhat more effective and avoids some code duplication in 2873 later real inlining pass for testcases with very many function calls. */ 2874 2875 namespace { 2876 2877 const pass_data pass_data_early_inline = 2878 { 2879 GIMPLE_PASS, /* type */ 2880 "einline", /* name */ 2881 OPTGROUP_INLINE, /* optinfo_flags */ 2882 TV_EARLY_INLINING, /* tv_id */ 2883 PROP_ssa, /* properties_required */ 2884 0, /* properties_provided */ 2885 0, /* properties_destroyed */ 2886 0, /* todo_flags_start */ 2887 0, /* todo_flags_finish */ 2888 }; 2889 2890 class pass_early_inline : public gimple_opt_pass 2891 { 2892 public: 2893 pass_early_inline (gcc::context *ctxt) 2894 : gimple_opt_pass (pass_data_early_inline, ctxt) 2895 {} 2896 2897 /* opt_pass methods: */ 2898 virtual unsigned int execute (function *); 2899 2900 }; // class pass_early_inline 2901 2902 unsigned int 2903 pass_early_inline::execute (function *fun) 2904 { 2905 return early_inliner (fun); 2906 } 2907 2908 } // anon namespace 2909 2910 gimple_opt_pass * 2911 make_pass_early_inline (gcc::context *ctxt) 2912 { 2913 return new pass_early_inline (ctxt); 2914 } 2915 2916 namespace { 2917 2918 const pass_data pass_data_ipa_inline = 2919 { 2920 IPA_PASS, /* type */ 2921 "inline", /* name */ 2922 OPTGROUP_INLINE, /* optinfo_flags */ 2923 TV_IPA_INLINING, /* tv_id */ 2924 0, /* properties_required */ 2925 0, /* properties_provided */ 2926 0, /* properties_destroyed */ 2927 0, /* todo_flags_start */ 2928 ( TODO_dump_symtab ), /* todo_flags_finish */ 2929 }; 2930 2931 class pass_ipa_inline : public ipa_opt_pass_d 2932 { 2933 public: 2934 pass_ipa_inline (gcc::context *ctxt) 2935 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt, 2936 NULL, /* generate_summary */ 2937 NULL, /* write_summary */ 2938 NULL, /* read_summary */ 2939 NULL, /* write_optimization_summary */ 2940 NULL, /* read_optimization_summary */ 2941 NULL, /* stmt_fixup */ 2942 0, /* function_transform_todo_flags_start */ 2943 inline_transform, /* function_transform */ 2944 NULL) /* variable_transform */ 2945 {} 2946 2947 /* opt_pass methods: */ 2948 virtual unsigned int execute (function *) { return ipa_inline (); } 2949 2950 }; // class pass_ipa_inline 2951 2952 } // anon namespace 2953 2954 ipa_opt_pass_d * 2955 make_pass_ipa_inline (gcc::context *ctxt) 2956 { 2957 return new pass_ipa_inline (ctxt); 2958 } 2959