1/* Profile counter container type. 2 Copyright (C) 2017-2022 Free Software Foundation, Inc. 3 Contributed by Jan Hubicka 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING3. If not see 19<http://www.gnu.org/licenses/>. */ 20 21#ifndef GCC_PROFILE_COUNT_H 22#define GCC_PROFILE_COUNT_H 23 24struct function; 25struct profile_count; 26class sreal; 27 28/* Quality of the profile count. Because gengtype does not support enums 29 inside of classes, this is in global namespace. */ 30enum profile_quality { 31 /* Uninitialized value. */ 32 UNINITIALIZED_PROFILE, 33 34 /* Profile is based on static branch prediction heuristics and may 35 or may not match reality. It is local to function and cannot be compared 36 inter-procedurally. Never used by probabilities (they are always local). 37 */ 38 GUESSED_LOCAL, 39 40 /* Profile was read by feedback and was 0, we used local heuristics to guess 41 better. This is the case of functions not run in profile feedback. 42 Never used by probabilities. */ 43 GUESSED_GLOBAL0, 44 45 /* Same as GUESSED_GLOBAL0 but global count is adjusted 0. */ 46 GUESSED_GLOBAL0_ADJUSTED, 47 48 /* Profile is based on static branch prediction heuristics. It may or may 49 not reflect the reality but it can be compared interprocedurally 50 (for example, we inlined function w/o profile feedback into function 51 with feedback and propagated from that). 52 Never used by probabilities. */ 53 GUESSED, 54 55 /* Profile was determined by autofdo. */ 56 AFDO, 57 58 /* Profile was originally based on feedback but it was adjusted 59 by code duplicating optimization. It may not precisely reflect the 60 particular code path. */ 61 ADJUSTED, 62 63 /* Profile was read from profile feedback or determined by accurate static 64 method. */ 65 PRECISE 66}; 67 68extern const char *profile_quality_as_string (enum profile_quality); 69extern bool parse_profile_quality (const char *value, 70 profile_quality *quality); 71 72/* The base value for branch probability notes and edge probabilities. */ 73#define REG_BR_PROB_BASE 10000 74 75#define RDIV(X,Y) (((X) + (Y) / 2) / (Y)) 76 77bool slow_safe_scale_64bit (uint64_t a, uint64_t b, uint64_t c, uint64_t *res); 78 79/* Compute RES=(a*b + c/2)/c capping and return false if overflow happened. */ 80 81inline bool 82safe_scale_64bit (uint64_t a, uint64_t b, uint64_t c, uint64_t *res) 83{ 84#if (GCC_VERSION >= 5000) 85 uint64_t tmp; 86 if (!__builtin_mul_overflow (a, b, &tmp) 87 && !__builtin_add_overflow (tmp, c/2, &tmp)) 88 { 89 *res = tmp / c; 90 return true; 91 } 92 if (c == 1) 93 { 94 *res = (uint64_t) -1; 95 return false; 96 } 97#else 98 if (a < ((uint64_t)1 << 31) 99 && b < ((uint64_t)1 << 31) 100 && c < ((uint64_t)1 << 31)) 101 { 102 *res = (a * b + (c / 2)) / c; 103 return true; 104 } 105#endif 106 return slow_safe_scale_64bit (a, b, c, res); 107} 108 109/* Data type to hold probabilities. It implements fixed point arithmetics 110 with capping so probability is always in range [0,1] and scaling requiring 111 values greater than 1 needs to be represented otherwise. 112 113 In addition to actual value the quality of profile is tracked and propagated 114 through all operations. Special value UNINITIALIZED_PROFILE is used for probabilities 115 that has not been determined yet (for example because of 116 -fno-guess-branch-probability) 117 118 Typically probabilities are derived from profile feedback (via 119 probability_in_gcov_type), autoFDO or guessed statically and then propagated 120 thorough the compilation. 121 122 Named probabilities are available: 123 - never (0 probability) 124 - guessed_never 125 - very_unlikely (1/2000 probability) 126 - unlikely (1/5 probability) 127 - even (1/2 probability) 128 - likely (4/5 probability) 129 - very_likely (1999/2000 probability) 130 - guessed_always 131 - always 132 133 Named probabilities except for never/always are assumed to be statically 134 guessed and thus not necessarily accurate. The difference between never 135 and guessed_never is that the first one should be used only in case that 136 well behaving program will very likely not execute the "never" path. 137 For example if the path is going to abort () call or it exception handling. 138 139 Always and guessed_always probabilities are symmetric. 140 141 For legacy code we support conversion to/from REG_BR_PROB_BASE based fixpoint 142 integer arithmetics. Once the code is converted to branch probabilities, 143 these conversions will probably go away because they are lossy. 144*/ 145 146class GTY((user)) profile_probability 147{ 148 static const int n_bits = 29; 149 /* We can technically use ((uint32_t) 1 << (n_bits - 1)) - 2 but that 150 will lead to harder multiplication sequences. */ 151 static const uint32_t max_probability = (uint32_t) 1 << (n_bits - 2); 152 static const uint32_t uninitialized_probability 153 = ((uint32_t) 1 << (n_bits - 1)) - 1; 154 155 uint32_t m_val : 29; 156 enum profile_quality m_quality : 3; 157 158 friend struct profile_count; 159public: 160 profile_probability (): m_val (uninitialized_probability), 161 m_quality (GUESSED) 162 {} 163 164 profile_probability (uint32_t val, profile_quality quality): 165 m_val (val), m_quality (quality) 166 {} 167 168 /* Named probabilities. */ 169 static profile_probability never () 170 { 171 profile_probability ret; 172 ret.m_val = 0; 173 ret.m_quality = PRECISE; 174 return ret; 175 } 176 177 static profile_probability guessed_never () 178 { 179 profile_probability ret; 180 ret.m_val = 0; 181 ret.m_quality = GUESSED; 182 return ret; 183 } 184 185 static profile_probability very_unlikely () 186 { 187 /* Be consistent with PROB_VERY_UNLIKELY in predict.h. */ 188 profile_probability r = guessed_always ().apply_scale (1, 2000); 189 r.m_val--; 190 return r; 191 } 192 193 static profile_probability unlikely () 194 { 195 /* Be consistent with PROB_VERY_LIKELY in predict.h. */ 196 profile_probability r = guessed_always ().apply_scale (1, 5); 197 r.m_val--; 198 return r; 199 } 200 201 static profile_probability even () 202 { 203 return guessed_always ().apply_scale (1, 2); 204 } 205 206 static profile_probability very_likely () 207 { 208 return always () - very_unlikely (); 209 } 210 211 static profile_probability likely () 212 { 213 return always () - unlikely (); 214 } 215 216 static profile_probability guessed_always () 217 { 218 profile_probability ret; 219 ret.m_val = max_probability; 220 ret.m_quality = GUESSED; 221 return ret; 222 } 223 224 static profile_probability always () 225 { 226 profile_probability ret; 227 ret.m_val = max_probability; 228 ret.m_quality = PRECISE; 229 return ret; 230 } 231 232 /* Probabilities which has not been initialized. Either because 233 initialization did not happen yet or because profile is unknown. */ 234 static profile_probability uninitialized () 235 { 236 profile_probability c; 237 c.m_val = uninitialized_probability; 238 c.m_quality = GUESSED; 239 return c; 240 } 241 242 /* Return true if value has been initialized. */ 243 bool initialized_p () const 244 { 245 return m_val != uninitialized_probability; 246 } 247 248 /* Return true if value can be trusted. */ 249 bool reliable_p () const 250 { 251 return m_quality >= ADJUSTED; 252 } 253 254 /* Conversion from and to REG_BR_PROB_BASE integer fixpoint arithmetics. 255 this is mostly to support legacy code and should go away. */ 256 static profile_probability from_reg_br_prob_base (int v) 257 { 258 profile_probability ret; 259 gcc_checking_assert (v >= 0 && v <= REG_BR_PROB_BASE); 260 ret.m_val = RDIV (v * (uint64_t) max_probability, REG_BR_PROB_BASE); 261 ret.m_quality = GUESSED; 262 return ret; 263 } 264 265 /* Return THIS with quality set to ADJUSTED. */ 266 profile_probability adjusted () const 267 { 268 profile_probability ret = *this; 269 if (!initialized_p ()) 270 return *this; 271 ret.m_quality = ADJUSTED; 272 return ret; 273 } 274 275 int to_reg_br_prob_base () const 276 { 277 gcc_checking_assert (initialized_p ()); 278 return RDIV (m_val * (uint64_t) REG_BR_PROB_BASE, max_probability); 279 } 280 281 /* Conversion to and from RTL representation of profile probabilities. */ 282 static profile_probability from_reg_br_prob_note (int v) 283 { 284 profile_probability ret; 285 ret.m_val = ((unsigned int)v) / 8; 286 ret.m_quality = (enum profile_quality)(v & 7); 287 return ret; 288 } 289 290 int to_reg_br_prob_note () const 291 { 292 gcc_checking_assert (initialized_p ()); 293 int ret = m_val * 8 + m_quality; 294 gcc_checking_assert (from_reg_br_prob_note (ret) == *this); 295 return ret; 296 } 297 298 /* Return VAL1/VAL2. */ 299 static profile_probability probability_in_gcov_type 300 (gcov_type val1, gcov_type val2) 301 { 302 profile_probability ret; 303 gcc_checking_assert (val1 >= 0 && val2 > 0); 304 if (val1 > val2) 305 ret.m_val = max_probability; 306 else 307 { 308 uint64_t tmp; 309 safe_scale_64bit (val1, max_probability, val2, &tmp); 310 gcc_checking_assert (tmp <= max_probability); 311 ret.m_val = tmp; 312 } 313 ret.m_quality = PRECISE; 314 return ret; 315 } 316 317 /* Basic operations. */ 318 bool operator== (const profile_probability &other) const 319 { 320 return m_val == other.m_val && m_quality == other.m_quality; 321 } 322 323 profile_probability operator+ (const profile_probability &other) const 324 { 325 if (other == never ()) 326 return *this; 327 if (*this == never ()) 328 return other; 329 if (!initialized_p () || !other.initialized_p ()) 330 return uninitialized (); 331 332 profile_probability ret; 333 ret.m_val = MIN ((uint32_t)(m_val + other.m_val), max_probability); 334 ret.m_quality = MIN (m_quality, other.m_quality); 335 return ret; 336 } 337 338 profile_probability &operator+= (const profile_probability &other) 339 { 340 if (other == never ()) 341 return *this; 342 if (*this == never ()) 343 { 344 *this = other; 345 return *this; 346 } 347 if (!initialized_p () || !other.initialized_p ()) 348 return *this = uninitialized (); 349 else 350 { 351 m_val = MIN ((uint32_t)(m_val + other.m_val), max_probability); 352 m_quality = MIN (m_quality, other.m_quality); 353 } 354 return *this; 355 } 356 357 profile_probability operator- (const profile_probability &other) const 358 { 359 if (*this == never () 360 || other == never ()) 361 return *this; 362 if (!initialized_p () || !other.initialized_p ()) 363 return uninitialized (); 364 profile_probability ret; 365 ret.m_val = m_val >= other.m_val ? m_val - other.m_val : 0; 366 ret.m_quality = MIN (m_quality, other.m_quality); 367 return ret; 368 } 369 370 profile_probability &operator-= (const profile_probability &other) 371 { 372 if (*this == never () 373 || other == never ()) 374 return *this; 375 if (!initialized_p () || !other.initialized_p ()) 376 return *this = uninitialized (); 377 else 378 { 379 m_val = m_val >= other.m_val ? m_val - other.m_val : 0; 380 m_quality = MIN (m_quality, other.m_quality); 381 } 382 return *this; 383 } 384 385 profile_probability operator* (const profile_probability &other) const 386 { 387 if (*this == never () 388 || other == never ()) 389 return never (); 390 if (!initialized_p () || !other.initialized_p ()) 391 return uninitialized (); 392 profile_probability ret; 393 ret.m_val = RDIV ((uint64_t)m_val * other.m_val, max_probability); 394 ret.m_quality = MIN (MIN (m_quality, other.m_quality), ADJUSTED); 395 return ret; 396 } 397 398 profile_probability &operator*= (const profile_probability &other) 399 { 400 if (*this == never () 401 || other == never ()) 402 return *this = never (); 403 if (!initialized_p () || !other.initialized_p ()) 404 return *this = uninitialized (); 405 else 406 { 407 m_val = RDIV ((uint64_t)m_val * other.m_val, max_probability); 408 m_quality = MIN (MIN (m_quality, other.m_quality), ADJUSTED); 409 } 410 return *this; 411 } 412 413 profile_probability operator/ (const profile_probability &other) const 414 { 415 if (*this == never ()) 416 return never (); 417 if (!initialized_p () || !other.initialized_p ()) 418 return uninitialized (); 419 profile_probability ret; 420 /* If we get probability above 1, mark it as unreliable and return 1. */ 421 if (m_val >= other.m_val) 422 { 423 ret.m_val = max_probability; 424 ret.m_quality = MIN (MIN (m_quality, other.m_quality), 425 GUESSED); 426 return ret; 427 } 428 else if (!m_val) 429 ret.m_val = 0; 430 else 431 { 432 gcc_checking_assert (other.m_val); 433 ret.m_val = MIN (RDIV ((uint64_t)m_val * max_probability, 434 other.m_val), 435 max_probability); 436 } 437 ret.m_quality = MIN (MIN (m_quality, other.m_quality), ADJUSTED); 438 return ret; 439 } 440 441 profile_probability &operator/= (const profile_probability &other) 442 { 443 if (*this == never ()) 444 return *this = never (); 445 if (!initialized_p () || !other.initialized_p ()) 446 return *this = uninitialized (); 447 else 448 { 449 /* If we get probability above 1, mark it as unreliable 450 and return 1. */ 451 if (m_val > other.m_val) 452 { 453 m_val = max_probability; 454 m_quality = MIN (MIN (m_quality, other.m_quality), 455 GUESSED); 456 return *this; 457 } 458 else if (!m_val) 459 ; 460 else 461 { 462 gcc_checking_assert (other.m_val); 463 m_val = MIN (RDIV ((uint64_t)m_val * max_probability, 464 other.m_val), 465 max_probability); 466 } 467 m_quality = MIN (MIN (m_quality, other.m_quality), ADJUSTED); 468 } 469 return *this; 470 } 471 472 /* Split *THIS (ORIG) probability into 2 probabilities, such that 473 the returned one (FIRST) is *THIS * CPROB and *THIS is 474 adjusted (SECOND) so that FIRST + FIRST.invert () * SECOND 475 == ORIG. This is useful e.g. when splitting a conditional 476 branch like: 477 if (cond) 478 goto lab; // ORIG probability 479 into 480 if (cond1) 481 goto lab; // FIRST = ORIG * CPROB probability 482 if (cond2) 483 goto lab; // SECOND probability 484 such that the overall probability of jumping to lab remains 485 the same. CPROB gives the relative probability between the 486 branches. */ 487 profile_probability split (const profile_probability &cprob) 488 { 489 profile_probability ret = *this * cprob; 490 /* The following is equivalent to: 491 *this = cprob.invert () * *this / ret.invert (); 492 Avoid scaling when overall outcome is supposed to be always. 493 Without knowing that one is inverse of other, the result would be 494 conservative. */ 495 if (!(*this == always ())) 496 *this = (*this - ret) / ret.invert (); 497 return ret; 498 } 499 500 gcov_type apply (gcov_type val) const 501 { 502 if (*this == uninitialized ()) 503 return val / 2; 504 return RDIV (val * m_val, max_probability); 505 } 506 507 /* Return 1-*THIS. */ 508 profile_probability invert () const 509 { 510 return always() - *this; 511 } 512 513 /* Return THIS with quality dropped to GUESSED. */ 514 profile_probability guessed () const 515 { 516 profile_probability ret = *this; 517 ret.m_quality = GUESSED; 518 return ret; 519 } 520 521 /* Return THIS with quality dropped to AFDO. */ 522 profile_probability afdo () const 523 { 524 profile_probability ret = *this; 525 ret.m_quality = AFDO; 526 return ret; 527 } 528 529 /* Return *THIS * NUM / DEN. */ 530 profile_probability apply_scale (int64_t num, int64_t den) const 531 { 532 if (*this == never ()) 533 return *this; 534 if (!initialized_p ()) 535 return uninitialized (); 536 profile_probability ret; 537 uint64_t tmp; 538 safe_scale_64bit (m_val, num, den, &tmp); 539 ret.m_val = MIN (tmp, max_probability); 540 ret.m_quality = MIN (m_quality, ADJUSTED); 541 return ret; 542 } 543 544 /* Return true when the probability of edge is reliable. 545 546 The profile guessing code is good at predicting branch outcome (i.e. 547 taken/not taken), that is predicted right slightly over 75% of time. 548 It is however notoriously poor on predicting the probability itself. 549 In general the profile appear a lot flatter (with probabilities closer 550 to 50%) than the reality so it is bad idea to use it to drive optimization 551 such as those disabling dynamic branch prediction for well predictable 552 branches. 553 554 There are two exceptions - edges leading to noreturn edges and edges 555 predicted by number of iterations heuristics are predicted well. This macro 556 should be able to distinguish those, but at the moment it simply check for 557 noreturn heuristic that is only one giving probability over 99% or bellow 558 1%. In future we might want to propagate reliability information across the 559 CFG if we find this information useful on multiple places. */ 560 bool probably_reliable_p () const 561 { 562 if (m_quality >= ADJUSTED) 563 return true; 564 if (!initialized_p ()) 565 return false; 566 return m_val < max_probability / 100 567 || m_val > max_probability - max_probability / 100; 568 } 569 570 /* Return false if profile_probability is bogus. */ 571 bool verify () const 572 { 573 gcc_checking_assert (m_quality != UNINITIALIZED_PROFILE); 574 if (m_val == uninitialized_probability) 575 return m_quality == GUESSED; 576 else if (m_quality < GUESSED) 577 return false; 578 return m_val <= max_probability; 579 } 580 581 /* Comparisons are three-state and conservative. False is returned if 582 the inequality cannot be decided. */ 583 bool operator< (const profile_probability &other) const 584 { 585 return initialized_p () && other.initialized_p () && m_val < other.m_val; 586 } 587 588 bool operator> (const profile_probability &other) const 589 { 590 return initialized_p () && other.initialized_p () && m_val > other.m_val; 591 } 592 593 bool operator<= (const profile_probability &other) const 594 { 595 return initialized_p () && other.initialized_p () && m_val <= other.m_val; 596 } 597 598 bool operator>= (const profile_probability &other) const 599 { 600 return initialized_p () && other.initialized_p () && m_val >= other.m_val; 601 } 602 603 /* Get the value of the count. */ 604 uint32_t value () const { return m_val; } 605 606 /* Get the quality of the count. */ 607 enum profile_quality quality () const { return m_quality; } 608 609 /* Output THIS to F. */ 610 void dump (FILE *f) const; 611 612 /* Output THIS to BUFFER. */ 613 void dump (char *buffer) const; 614 615 /* Print THIS to stderr. */ 616 void debug () const; 617 618 /* Return true if THIS is known to differ significantly from OTHER. */ 619 bool differs_from_p (profile_probability other) const; 620 621 /* Return if difference is greater than 50%. */ 622 bool differs_lot_from_p (profile_probability other) const; 623 624 /* COUNT1 times event happens with *THIS probability, COUNT2 times OTHER 625 happens with COUNT2 probability. Return probability that either *THIS or 626 OTHER happens. */ 627 profile_probability combine_with_count (profile_count count1, 628 profile_probability other, 629 profile_count count2) const; 630 631 /* Return probability as sreal. */ 632 sreal to_sreal () const; 633 /* LTO streaming support. */ 634 static profile_probability stream_in (class lto_input_block *); 635 void stream_out (struct output_block *); 636 void stream_out (struct lto_output_stream *); 637}; 638 639/* Main data type to hold profile counters in GCC. Profile counts originate 640 either from profile feedback, static profile estimation or both. We do not 641 perform whole program profile propagation and thus profile estimation 642 counters are often local to function, while counters from profile feedback 643 (or special cases of profile estimation) can be used inter-procedurally. 644 645 There are 3 basic types 646 1) local counters which are result of intra-procedural static profile 647 estimation. 648 2) ipa counters which are result of profile feedback or special case 649 of static profile estimation (such as in function main). 650 3) counters which counts as 0 inter-procedurally (because given function 651 was never run in train feedback) but they hold local static profile 652 estimate. 653 654 Counters of type 1 and 3 cannot be mixed with counters of different type 655 within operation (because whole function should use one type of counter) 656 with exception that global zero mix in most operations where outcome is 657 well defined. 658 659 To take local counter and use it inter-procedurally use ipa member function 660 which strips information irrelevant at the inter-procedural level. 661 662 Counters are 61bit integers representing number of executions during the 663 train run or normalized frequency within the function. 664 665 As the profile is maintained during the compilation, many adjustments are 666 made. Not all transformations can be made precisely, most importantly 667 when code is being duplicated. It also may happen that part of CFG has 668 profile counts known while other do not - for example when LTO optimizing 669 partly profiled program or when profile was lost due to COMDAT merging. 670 671 For this reason profile_count tracks more information than 672 just unsigned integer and it is also ready for profile mismatches. 673 The API of this data type represent operations that are natural 674 on profile counts - sum, difference and operation with scales and 675 probabilities. All operations are safe by never getting negative counts 676 and they do end up in uninitialized scale if any of the parameters is 677 uninitialized. 678 679 All comparisons that are three state and handling of probabilities. Thus 680 a < b is not equal to !(a >= b). 681 682 The following pre-defined counts are available: 683 684 profile_count::zero () for code that is known to execute zero times at 685 runtime (this can be detected statically i.e. for paths leading to 686 abort (); 687 profile_count::one () for code that is known to execute once (such as 688 main () function 689 profile_count::uninitialized () for unknown execution count. 690 691 */ 692 693struct GTY(()) profile_count 694{ 695public: 696 /* Use 62bit to hold basic block counters. Should be at least 697 64bit. Although a counter cannot be negative, we use a signed 698 type to hold various extra stages. */ 699 700 static const int n_bits = 61; 701 static const uint64_t max_count = ((uint64_t) 1 << n_bits) - 2; 702private: 703 static const uint64_t uninitialized_count = ((uint64_t) 1 << n_bits) - 1; 704 705#if defined (__arm__) && (__GNUC__ >= 6 && __GNUC__ <= 8) 706 /* Work-around for PR88469. A bug in the gcc-6/7/8 PCS layout code 707 incorrectly detects the alignment of a structure where the only 708 64-bit aligned object is a bit-field. We force the alignment of 709 the entire field to mitigate this. */ 710#define UINT64_BIT_FIELD_ALIGN __attribute__ ((aligned(8))) 711#else 712#define UINT64_BIT_FIELD_ALIGN 713#endif 714 uint64_t UINT64_BIT_FIELD_ALIGN m_val : n_bits; 715#undef UINT64_BIT_FIELD_ALIGN 716 enum profile_quality m_quality : 3; 717public: 718 719 /* Return true if both values can meaningfully appear in single function 720 body. We have either all counters in function local or global, otherwise 721 operations between them are not really defined well. */ 722 bool compatible_p (const profile_count other) const 723 { 724 if (!initialized_p () || !other.initialized_p ()) 725 return true; 726 if (*this == zero () 727 || other == zero ()) 728 return true; 729 /* Do not allow nonzero global profile together with local guesses 730 that are globally0. */ 731 if (ipa ().nonzero_p () 732 && !(other.ipa () == other)) 733 return false; 734 if (other.ipa ().nonzero_p () 735 && !(ipa () == *this)) 736 return false; 737 738 return ipa_p () == other.ipa_p (); 739 } 740 741 /* Used for counters which are expected to be never executed. */ 742 static profile_count zero () 743 { 744 return from_gcov_type (0); 745 } 746 747 static profile_count adjusted_zero () 748 { 749 profile_count c; 750 c.m_val = 0; 751 c.m_quality = ADJUSTED; 752 return c; 753 } 754 755 static profile_count guessed_zero () 756 { 757 profile_count c; 758 c.m_val = 0; 759 c.m_quality = GUESSED; 760 return c; 761 } 762 763 static profile_count one () 764 { 765 return from_gcov_type (1); 766 } 767 768 /* Value of counters which has not been initialized. Either because 769 initialization did not happen yet or because profile is unknown. */ 770 static profile_count uninitialized () 771 { 772 profile_count c; 773 c.m_val = uninitialized_count; 774 c.m_quality = GUESSED_LOCAL; 775 return c; 776 } 777 778 /* Conversion to gcov_type is lossy. */ 779 gcov_type to_gcov_type () const 780 { 781 gcc_checking_assert (initialized_p ()); 782 return m_val; 783 } 784 785 /* Return true if value has been initialized. */ 786 bool initialized_p () const 787 { 788 return m_val != uninitialized_count; 789 } 790 791 /* Return true if value can be trusted. */ 792 bool reliable_p () const 793 { 794 return m_quality >= ADJUSTED; 795 } 796 797 /* Return true if value can be operated inter-procedurally. */ 798 bool ipa_p () const 799 { 800 return !initialized_p () || m_quality >= GUESSED_GLOBAL0; 801 } 802 803 /* Return true if quality of profile is precise. */ 804 bool precise_p () const 805 { 806 return m_quality == PRECISE; 807 } 808 809 /* Get the value of the count. */ 810 uint64_t value () const { return m_val; } 811 812 /* Get the quality of the count. */ 813 enum profile_quality quality () const { return m_quality; } 814 815 /* When merging basic blocks, the two different profile counts are unified. 816 Return true if this can be done without losing info about profile. 817 The only case we care about here is when first BB contains something 818 that makes it terminate in a way not visible in CFG. */ 819 bool ok_for_merging (profile_count other) const 820 { 821 if (m_quality < ADJUSTED 822 || other.m_quality < ADJUSTED) 823 return true; 824 return !(other < *this); 825 } 826 827 /* When merging two BBs with different counts, pick common count that looks 828 most representative. */ 829 profile_count merge (profile_count other) const 830 { 831 if (*this == other || !other.initialized_p () 832 || m_quality > other.m_quality) 833 return *this; 834 if (other.m_quality > m_quality 835 || other > *this) 836 return other; 837 return *this; 838 } 839 840 /* Basic operations. */ 841 bool operator== (const profile_count &other) const 842 { 843 return m_val == other.m_val && m_quality == other.m_quality; 844 } 845 846 profile_count operator+ (const profile_count &other) const 847 { 848 if (other == zero ()) 849 return *this; 850 if (*this == zero ()) 851 return other; 852 if (!initialized_p () || !other.initialized_p ()) 853 return uninitialized (); 854 855 profile_count ret; 856 gcc_checking_assert (compatible_p (other)); 857 ret.m_val = m_val + other.m_val; 858 ret.m_quality = MIN (m_quality, other.m_quality); 859 return ret; 860 } 861 862 profile_count &operator+= (const profile_count &other) 863 { 864 if (other == zero ()) 865 return *this; 866 if (*this == zero ()) 867 { 868 *this = other; 869 return *this; 870 } 871 if (!initialized_p () || !other.initialized_p ()) 872 return *this = uninitialized (); 873 else 874 { 875 gcc_checking_assert (compatible_p (other)); 876 m_val += other.m_val; 877 m_quality = MIN (m_quality, other.m_quality); 878 } 879 return *this; 880 } 881 882 profile_count operator- (const profile_count &other) const 883 { 884 if (*this == zero () || other == zero ()) 885 return *this; 886 if (!initialized_p () || !other.initialized_p ()) 887 return uninitialized (); 888 gcc_checking_assert (compatible_p (other)); 889 profile_count ret; 890 ret.m_val = m_val >= other.m_val ? m_val - other.m_val : 0; 891 ret.m_quality = MIN (m_quality, other.m_quality); 892 return ret; 893 } 894 895 profile_count &operator-= (const profile_count &other) 896 { 897 if (*this == zero () || other == zero ()) 898 return *this; 899 if (!initialized_p () || !other.initialized_p ()) 900 return *this = uninitialized (); 901 else 902 { 903 gcc_checking_assert (compatible_p (other)); 904 m_val = m_val >= other.m_val ? m_val - other.m_val: 0; 905 m_quality = MIN (m_quality, other.m_quality); 906 } 907 return *this; 908 } 909 910 /* Return false if profile_count is bogus. */ 911 bool verify () const 912 { 913 gcc_checking_assert (m_quality != UNINITIALIZED_PROFILE); 914 return m_val != uninitialized_count || m_quality == GUESSED_LOCAL; 915 } 916 917 /* Comparisons are three-state and conservative. False is returned if 918 the inequality cannot be decided. */ 919 bool operator< (const profile_count &other) const 920 { 921 if (!initialized_p () || !other.initialized_p ()) 922 return false; 923 if (*this == zero ()) 924 return !(other == zero ()); 925 if (other == zero ()) 926 return false; 927 gcc_checking_assert (compatible_p (other)); 928 return m_val < other.m_val; 929 } 930 931 bool operator> (const profile_count &other) const 932 { 933 if (!initialized_p () || !other.initialized_p ()) 934 return false; 935 if (*this == zero ()) 936 return false; 937 if (other == zero ()) 938 return !(*this == zero ()); 939 gcc_checking_assert (compatible_p (other)); 940 return initialized_p () && other.initialized_p () && m_val > other.m_val; 941 } 942 943 bool operator< (const gcov_type other) const 944 { 945 gcc_checking_assert (ipa_p ()); 946 gcc_checking_assert (other >= 0); 947 return ipa ().initialized_p () && ipa ().m_val < (uint64_t) other; 948 } 949 950 bool operator> (const gcov_type other) const 951 { 952 gcc_checking_assert (ipa_p ()); 953 gcc_checking_assert (other >= 0); 954 return ipa ().initialized_p () && ipa ().m_val > (uint64_t) other; 955 } 956 957 bool operator<= (const profile_count &other) const 958 { 959 if (!initialized_p () || !other.initialized_p ()) 960 return false; 961 if (*this == zero ()) 962 return true; 963 if (other == zero ()) 964 return (*this == zero ()); 965 gcc_checking_assert (compatible_p (other)); 966 return m_val <= other.m_val; 967 } 968 969 bool operator>= (const profile_count &other) const 970 { 971 if (!initialized_p () || !other.initialized_p ()) 972 return false; 973 if (other == zero ()) 974 return true; 975 if (*this == zero ()) 976 return (other == zero ()); 977 gcc_checking_assert (compatible_p (other)); 978 return m_val >= other.m_val; 979 } 980 981 bool operator<= (const gcov_type other) const 982 { 983 gcc_checking_assert (ipa_p ()); 984 gcc_checking_assert (other >= 0); 985 return ipa ().initialized_p () && ipa ().m_val <= (uint64_t) other; 986 } 987 988 bool operator>= (const gcov_type other) const 989 { 990 gcc_checking_assert (ipa_p ()); 991 gcc_checking_assert (other >= 0); 992 return ipa ().initialized_p () && ipa ().m_val >= (uint64_t) other; 993 } 994 995 /* Return true when value is not zero and can be used for scaling. 996 This is different from *this > 0 because that requires counter to 997 be IPA. */ 998 bool nonzero_p () const 999 { 1000 return initialized_p () && m_val != 0; 1001 } 1002 1003 /* Make counter forcibly nonzero. */ 1004 profile_count force_nonzero () const 1005 { 1006 if (!initialized_p ()) 1007 return *this; 1008 profile_count ret = *this; 1009 if (ret.m_val == 0) 1010 { 1011 ret.m_val = 1; 1012 ret.m_quality = MIN (m_quality, ADJUSTED); 1013 } 1014 return ret; 1015 } 1016 1017 profile_count max (profile_count other) const 1018 { 1019 profile_count val = *this; 1020 1021 /* Always prefer nonzero IPA counts over local counts. */ 1022 if (ipa ().nonzero_p () || other.ipa ().nonzero_p ()) 1023 { 1024 val = ipa (); 1025 other = other.ipa (); 1026 } 1027 if (!initialized_p ()) 1028 return other; 1029 if (!other.initialized_p ()) 1030 return *this; 1031 if (*this == zero ()) 1032 return other; 1033 if (other == zero ()) 1034 return *this; 1035 gcc_checking_assert (compatible_p (other)); 1036 if (val.m_val < other.m_val || (m_val == other.m_val 1037 && val.m_quality < other.m_quality)) 1038 return other; 1039 return *this; 1040 } 1041 1042 /* PROB is a probability in scale 0...REG_BR_PROB_BASE. Scale counter 1043 accordingly. */ 1044 profile_count apply_probability (int prob) const 1045 { 1046 gcc_checking_assert (prob >= 0 && prob <= REG_BR_PROB_BASE); 1047 if (m_val == 0) 1048 return *this; 1049 if (!initialized_p ()) 1050 return uninitialized (); 1051 profile_count ret; 1052 ret.m_val = RDIV (m_val * prob, REG_BR_PROB_BASE); 1053 ret.m_quality = MIN (m_quality, ADJUSTED); 1054 return ret; 1055 } 1056 1057 /* Scale counter according to PROB. */ 1058 profile_count apply_probability (profile_probability prob) const 1059 { 1060 if (*this == zero ()) 1061 return *this; 1062 if (prob == profile_probability::never ()) 1063 return zero (); 1064 if (!initialized_p ()) 1065 return uninitialized (); 1066 profile_count ret; 1067 uint64_t tmp; 1068 safe_scale_64bit (m_val, prob.m_val, profile_probability::max_probability, 1069 &tmp); 1070 ret.m_val = tmp; 1071 ret.m_quality = MIN (m_quality, prob.m_quality); 1072 return ret; 1073 } 1074 1075 /* Return *THIS * NUM / DEN. */ 1076 profile_count apply_scale (int64_t num, int64_t den) const 1077 { 1078 if (m_val == 0) 1079 return *this; 1080 if (!initialized_p ()) 1081 return uninitialized (); 1082 profile_count ret; 1083 uint64_t tmp; 1084 1085 gcc_checking_assert (num >= 0 && den > 0); 1086 safe_scale_64bit (m_val, num, den, &tmp); 1087 ret.m_val = MIN (tmp, max_count); 1088 ret.m_quality = MIN (m_quality, ADJUSTED); 1089 return ret; 1090 } 1091 1092 profile_count apply_scale (profile_count num, profile_count den) const 1093 { 1094 if (*this == zero ()) 1095 return *this; 1096 if (num == zero ()) 1097 return num; 1098 if (!initialized_p () || !num.initialized_p () || !den.initialized_p ()) 1099 return uninitialized (); 1100 if (num == den) 1101 return *this; 1102 gcc_checking_assert (den.m_val); 1103 1104 profile_count ret; 1105 uint64_t val; 1106 safe_scale_64bit (m_val, num.m_val, den.m_val, &val); 1107 ret.m_val = MIN (val, max_count); 1108 ret.m_quality = MIN (MIN (MIN (m_quality, ADJUSTED), 1109 num.m_quality), den.m_quality); 1110 /* Be sure that ret is not local if num is global. 1111 Also ensure that ret is not global0 when num is global. */ 1112 if (num.ipa_p ()) 1113 ret.m_quality = MAX (ret.m_quality, 1114 num == num.ipa () ? GUESSED : num.m_quality); 1115 return ret; 1116 } 1117 1118 /* Return THIS with quality dropped to GUESSED_LOCAL. */ 1119 profile_count guessed_local () const 1120 { 1121 profile_count ret = *this; 1122 if (!initialized_p ()) 1123 return *this; 1124 ret.m_quality = GUESSED_LOCAL; 1125 return ret; 1126 } 1127 1128 /* We know that profile is globally 0 but keep local profile if present. */ 1129 profile_count global0 () const 1130 { 1131 profile_count ret = *this; 1132 if (!initialized_p ()) 1133 return *this; 1134 ret.m_quality = GUESSED_GLOBAL0; 1135 return ret; 1136 } 1137 1138 /* We know that profile is globally adjusted 0 but keep local profile 1139 if present. */ 1140 profile_count global0adjusted () const 1141 { 1142 profile_count ret = *this; 1143 if (!initialized_p ()) 1144 return *this; 1145 ret.m_quality = GUESSED_GLOBAL0_ADJUSTED; 1146 return ret; 1147 } 1148 1149 /* Return THIS with quality dropped to GUESSED. */ 1150 profile_count guessed () const 1151 { 1152 profile_count ret = *this; 1153 ret.m_quality = MIN (ret.m_quality, GUESSED); 1154 return ret; 1155 } 1156 1157 /* Return variant of profile count which is always safe to compare 1158 across functions. */ 1159 profile_count ipa () const 1160 { 1161 if (m_quality > GUESSED_GLOBAL0_ADJUSTED) 1162 return *this; 1163 if (m_quality == GUESSED_GLOBAL0) 1164 return zero (); 1165 if (m_quality == GUESSED_GLOBAL0_ADJUSTED) 1166 return adjusted_zero (); 1167 return uninitialized (); 1168 } 1169 1170 /* Return THIS with quality dropped to AFDO. */ 1171 profile_count afdo () const 1172 { 1173 profile_count ret = *this; 1174 ret.m_quality = AFDO; 1175 return ret; 1176 } 1177 1178 /* Return probability of event with counter THIS within event with counter 1179 OVERALL. */ 1180 profile_probability probability_in (const profile_count overall) const 1181 { 1182 if (*this == zero () 1183 && !(overall == zero ())) 1184 return profile_probability::never (); 1185 if (!initialized_p () || !overall.initialized_p () 1186 || !overall.m_val) 1187 return profile_probability::uninitialized (); 1188 if (*this == overall && m_quality == PRECISE) 1189 return profile_probability::always (); 1190 profile_probability ret; 1191 gcc_checking_assert (compatible_p (overall)); 1192 1193 if (overall.m_val < m_val) 1194 { 1195 ret.m_val = profile_probability::max_probability; 1196 ret.m_quality = GUESSED; 1197 return ret; 1198 } 1199 else 1200 ret.m_val = RDIV (m_val * profile_probability::max_probability, 1201 overall.m_val); 1202 ret.m_quality = MIN (MAX (MIN (m_quality, overall.m_quality), 1203 GUESSED), ADJUSTED); 1204 return ret; 1205 } 1206 1207 int to_frequency (struct function *fun) const; 1208 int to_cgraph_frequency (profile_count entry_bb_count) const; 1209 sreal to_sreal_scale (profile_count in, bool *known = NULL) const; 1210 1211 /* Output THIS to F. */ 1212 void dump (FILE *f) const; 1213 1214 /* Output THIS to BUFFER. */ 1215 void dump (char *buffer) const; 1216 1217 /* Print THIS to stderr. */ 1218 void debug () const; 1219 1220 /* Return true if THIS is known to differ significantly from OTHER. */ 1221 bool differs_from_p (profile_count other) const; 1222 1223 /* We want to scale profile across function boundary from NUM to DEN. 1224 Take care of the side case when NUM and DEN are zeros of incompatible 1225 kinds. */ 1226 static void adjust_for_ipa_scaling (profile_count *num, profile_count *den); 1227 1228 /* THIS is a count of bb which is known to be executed IPA times. 1229 Combine this information into bb counter. This means returning IPA 1230 if it is nonzero, not changing anything if IPA is uninitialized 1231 and if IPA is zero, turning THIS into corresponding local profile with 1232 global0. */ 1233 profile_count combine_with_ipa_count (profile_count ipa); 1234 1235 /* Same as combine_with_ipa_count but inside function with count IPA2. */ 1236 profile_count combine_with_ipa_count_within 1237 (profile_count ipa, profile_count ipa2); 1238 1239 /* The profiling runtime uses gcov_type, which is usually 64bit integer. 1240 Conversions back and forth are used to read the coverage and get it 1241 into internal representation. */ 1242 static profile_count from_gcov_type (gcov_type v, 1243 profile_quality quality = PRECISE); 1244 1245 /* LTO streaming support. */ 1246 static profile_count stream_in (class lto_input_block *); 1247 void stream_out (struct output_block *); 1248 void stream_out (struct lto_output_stream *); 1249}; 1250#endif 1251