1/* params.def - Run-time parameters. 2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 3 2011, 2012 4 Free Software Foundation, Inc. 5 Written by Mark Mitchell <mark@codesourcery.com>. 6 7This file is part of GCC. 8 9GCC is free software; you can redistribute it and/or modify it under 10the terms of the GNU General Public License as published by the Free 11Software Foundation; either version 3, or (at your option) any later 12version. 13 14GCC is distributed in the hope that it will be useful, but WITHOUT ANY 15WARRANTY; without even the implied warranty of MERCHANTABILITY or 16FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 17for more details. 18 19You should have received a copy of the GNU General Public License 20along with GCC; see the file COPYING3. If not see 21<http://www.gnu.org/licenses/>. */ 22 23/* This file contains definitions for language-independent 24 parameters. The DEFPARAM macro takes 6 arguments: 25 26 - The enumeral corresponding to this parameter. 27 28 - The name that can be used to set this parameter using the 29 command-line option `--param <name>=<value>'. 30 31 - A help string explaining how the parameter is used. 32 33 - A default value for the parameter. 34 35 - The minimum acceptable value for the parameter. 36 37 - The maximum acceptable value for the parameter (if greater than 38 the minimum). 39 40 Be sure to add an entry to invoke.texi summarizing the parameter. */ 41 42/* When branch is predicted to be taken with probability lower than this 43 threshold (in percent), then it is considered well predictable. */ 44DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME, 45 "predictable-branch-outcome", 46 "Maximal estimated outcome of branch considered predictable", 47 2, 0, 50) 48 49/* The single function inlining limit. This is the maximum size 50 of a function counted in internal gcc instructions (not in 51 real machine instructions) that is eligible for inlining 52 by the tree inliner. 53 The default value is 450. 54 Only functions marked inline (or methods defined in the class 55 definition for C++) are affected by this. 56 There are more restrictions to inlining: If inlined functions 57 call other functions, the already inlined instructions are 58 counted and once the recursive inline limit (see 59 "max-inline-insns" parameter) is exceeded, the acceptable size 60 gets decreased. */ 61DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE, 62 "max-inline-insns-single", 63 "The maximum number of instructions in a single function eligible for inlining", 64 400, 0, 0) 65 66/* The single function inlining limit for functions that are 67 inlined by virtue of -finline-functions (-O3). 68 This limit should be chosen to be below or equal to the limit 69 that is applied to functions marked inlined (or defined in the 70 class declaration in C++) given by the "max-inline-insns-single" 71 parameter. 72 The default value is 40. */ 73DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO, 74 "max-inline-insns-auto", 75 "The maximum number of instructions when automatically inlining", 76 40, 0, 0) 77 78DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE, 79 "max-inline-insns-recursive", 80 "The maximum number of instructions inline function can grow to via recursive inlining", 81 450, 0, 0) 82 83DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO, 84 "max-inline-insns-recursive-auto", 85 "The maximum number of instructions non-inline function can grow to via recursive inlining", 86 450, 0, 0) 87 88DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH, 89 "max-inline-recursive-depth", 90 "The maximum depth of recursive inlining for inline functions", 91 8, 0, 0) 92 93DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO, 94 "max-inline-recursive-depth-auto", 95 "The maximum depth of recursive inlining for non-inline functions", 96 8, 0, 0) 97 98DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY, 99 "min-inline-recursive-probability", 100 "Inline recursively only when the probability of call being executed exceeds the parameter", 101 10, 0, 0) 102 103/* Limit of iterations of early inliner. This basically bounds number of 104 nested indirect calls early inliner can resolve. Deeper chains are still 105 handled by late inlining. */ 106DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS, 107 "max-early-inliner-iterations", 108 "The maximum number of nested indirect inlining performed by early inliner", 109 10, 0, 0) 110 111/* Limit on probability of entry BB. */ 112DEFPARAM (PARAM_COMDAT_SHARING_PROBABILITY, 113 "comdat-sharing-probability", 114 "Probability that COMDAT function will be shared with different compilation unit", 115 20, 0, 0) 116 117/* Limit on probability of entry BB. */ 118DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY, 119 "partial-inlining-entry-probability", 120 "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen", 121 70, 0, 0) 122 123/* Limit the number of expansions created by the variable expansion 124 optimization to avoid register pressure. */ 125DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS, 126 "max-variable-expansions-in-unroller", 127 "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling", 128 1, 0, 0) 129 130/* Limit loop autovectorization to loops with large enough iteration count. */ 131DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND, 132 "min-vect-loop-bound", 133 "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization", 134 1, 1, 0) 135 136/* The maximum number of instructions to consider when looking for an 137 instruction to fill a delay slot. If more than this arbitrary 138 number of instructions is searched, the time savings from filling 139 the delay slot will be minimal so stop searching. Increasing 140 values mean more aggressive optimization, making the compile time 141 increase with probably small improvement in executable run time. */ 142DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH, 143 "max-delay-slot-insn-search", 144 "The maximum number of instructions to consider to fill a delay slot", 145 100, 0, 0) 146 147/* When trying to fill delay slots, the maximum number of instructions 148 to consider when searching for a block with valid live register 149 information. Increasing this arbitrarily chosen value means more 150 aggressive optimization, increasing the compile time. This 151 parameter should be removed when the delay slot code is rewritten 152 to maintain the control-flow graph. */ 153DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH, 154 "max-delay-slot-live-search", 155 "The maximum number of instructions to consider to find accurate live register information", 156 333, 0, 0) 157 158/* This parameter limits the number of branch elements that the 159 scheduler will track anti-dependencies through without resetting 160 the tracking mechanism. Large functions with few calls or barriers 161 can generate lists containing many 1000's of dependencies. Generally 162 the compiler either uses all available memory, or runs for far too long. */ 163DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH, 164 "max-pending-list-length", 165 "The maximum length of scheduling's pending operations list", 166 32, 0, 0) 167 168/* This parameter limits the number of backtracking attempts when using the 169 haifa scheduler for modulo scheduling. */ 170DEFPARAM(PARAM_MAX_MODULO_BACKTRACK_ATTEMPTS, 171 "max-modulo-backtrack-attempts", 172 "The maximum number of backtrack attempts the scheduler should make when modulo scheduling a loop", 173 40, 0, 0) 174 175DEFPARAM(PARAM_LARGE_FUNCTION_INSNS, 176 "large-function-insns", 177 "The size of function body to be considered large", 178 2700, 0, 0) 179DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH, 180 "large-function-growth", 181 "Maximal growth due to inlining of large function (in percent)", 182 100, 0, 0) 183DEFPARAM(PARAM_LARGE_UNIT_INSNS, 184 "large-unit-insns", 185 "The size of translation unit to be considered large", 186 10000, 0, 0) 187DEFPARAM(PARAM_INLINE_UNIT_GROWTH, 188 "inline-unit-growth", 189 "How much can given compilation unit grow because of the inlining (in percent)", 190 30, 0, 0) 191DEFPARAM(PARAM_IPCP_UNIT_GROWTH, 192 "ipcp-unit-growth", 193 "How much can given compilation unit grow because of the interprocedural constant propagation (in percent)", 194 10, 0, 0) 195DEFPARAM(PARAM_EARLY_INLINING_INSNS, 196 "early-inlining-insns", 197 "Maximal estimated growth of function body caused by early inlining of single call", 198 11, 0, 0) 199DEFPARAM(PARAM_LARGE_STACK_FRAME, 200 "large-stack-frame", 201 "The size of stack frame to be considered large", 202 256, 0, 0) 203DEFPARAM(PARAM_STACK_FRAME_GROWTH, 204 "large-stack-frame-growth", 205 "Maximal stack frame growth due to inlining (in percent)", 206 1000, 0, 0) 207 208/* The GCSE optimization will be disabled if it would require 209 significantly more memory than this value. */ 210DEFPARAM(PARAM_MAX_GCSE_MEMORY, 211 "max-gcse-memory", 212 "The maximum amount of memory to be allocated by GCSE", 213 50 * 1024 * 1024, 0, 0) 214 215/* The GCSE optimization of an expression will avoided if the ratio of 216 insertions to deletions is greater than this value. */ 217DEFPARAM(PARAM_MAX_GCSE_INSERTION_RATIO, 218 "max-gcse-insertion-ratio", 219 "The maximum ratio of insertions to deletions of expressions in GCSE", 220 20, 0, 0) 221 222/* This is the threshold ratio when to perform partial redundancy 223 elimination after reload. We perform partial redundancy elimination 224 when the following holds: 225 (Redundant load execution count) 226 ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION 227 (Added loads execution count) */ 228DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION, 229 "gcse-after-reload-partial-fraction", 230 "The threshold ratio for performing partial redundancy elimination after reload", 231 3, 0, 0) 232/* This is the threshold ratio of the critical edges execution count compared to 233 the redundant loads execution count that permits performing the load 234 redundancy elimination in gcse after reload. */ 235DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION, 236 "gcse-after-reload-critical-fraction", 237 "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload", 238 10, 0, 0) 239 240/* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor 241 to calculate maximum distance for which an expression is allowed to move 242 from its rtx_cost. */ 243DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO, 244 "gcse-cost-distance-ratio", 245 "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations", 246 10, 0, 0) 247/* GCSE won't restrict distance for which an expression with rtx_cost greater 248 than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move. */ 249DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST, 250 "gcse-unrestricted-cost", 251 "Cost at which GCSE optimizations will not constraint the distance an expression can travel", 252 3, 0, 0) 253 254/* How deep from a given basic block the dominator tree should be searched 255 for expressions to hoist to the block. The value of 0 will avoid limiting 256 the search. */ 257DEFPARAM(PARAM_MAX_HOIST_DEPTH, 258 "max-hoist-depth", 259 "Maximum depth of search in the dominator tree for expressions to hoist", 260 30, 0, 0) 261 262/* This parameter limits the number of insns in a loop that will be unrolled, 263 and by how much the loop is unrolled. 264 265 This limit should be at most half of the peeling limits: loop unroller 266 decides to not unroll loops that iterate fewer than 2*number of allowed 267 unrollings and thus we would have loops that are neither peeled or unrolled 268 otherwise. */ 269DEFPARAM(PARAM_MAX_UNROLLED_INSNS, 270 "max-unrolled-insns", 271 "The maximum number of instructions to consider to unroll in a loop", 272 200, 0, 0) 273/* This parameter limits how many times the loop is unrolled depending 274 on number of insns really executed in each iteration. */ 275DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS, 276 "max-average-unrolled-insns", 277 "The maximum number of instructions to consider to unroll in a loop on average", 278 80, 0, 0) 279/* The maximum number of unrollings of a single loop. */ 280DEFPARAM(PARAM_MAX_UNROLL_TIMES, 281 "max-unroll-times", 282 "The maximum number of unrollings of a single loop", 283 8, 0, 0) 284/* The maximum number of insns of a peeled loop. */ 285DEFPARAM(PARAM_MAX_PEELED_INSNS, 286 "max-peeled-insns", 287 "The maximum number of insns of a peeled loop", 288 400, 0, 0) 289/* The maximum number of peelings of a single loop. */ 290DEFPARAM(PARAM_MAX_PEEL_TIMES, 291 "max-peel-times", 292 "The maximum number of peelings of a single loop", 293 16, 0, 0) 294/* The maximum number of insns of a peeled loop. */ 295DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS, 296 "max-completely-peeled-insns", 297 "The maximum number of insns of a completely peeled loop", 298 400, 0, 0) 299/* The maximum number of peelings of a single loop that is peeled completely. */ 300DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES, 301 "max-completely-peel-times", 302 "The maximum number of peelings of a single loop that is peeled completely", 303 16, 0, 0) 304/* The maximum number of insns of a peeled loop that rolls only once. */ 305DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS, 306 "max-once-peeled-insns", 307 "The maximum number of insns of a peeled loop that rolls only once", 308 400, 0, 0) 309/* The maximum depth of a loop nest we completely peel. */ 310DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS, 311 "max-completely-peel-loop-nest-depth", 312 "The maximum depth of a loop nest we completely peel", 313 8, 0, 0) 314 315/* The maximum number of insns of an unswitched loop. */ 316DEFPARAM(PARAM_MAX_UNSWITCH_INSNS, 317 "max-unswitch-insns", 318 "The maximum number of insns of an unswitched loop", 319 50, 0, 0) 320/* The maximum level of recursion in unswitch_single_loop. */ 321DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL, 322 "max-unswitch-level", 323 "The maximum number of unswitchings in a single loop", 324 3, 0, 0) 325 326/* The maximum number of iterations of a loop the brute force algorithm 327 for analysis of # of iterations of the loop tries to evaluate. */ 328DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK, 329 "max-iterations-to-track", 330 "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates", 331 1000, 0, 0) 332/* A cutoff to avoid costly computations of the number of iterations in 333 the doloop transformation. */ 334DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST, 335 "max-iterations-computation-cost", 336 "Bound on the cost of an expression to compute the number of iterations", 337 10, 0, 0) 338 339/* This parameter is used to tune SMS MAX II calculations. */ 340DEFPARAM(PARAM_SMS_MAX_II_FACTOR, 341 "sms-max-ii-factor", 342 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop", 343 100, 0, 0) 344/* The minimum value of stage count that swing modulo scheduler will generate. */ 345DEFPARAM(PARAM_SMS_MIN_SC, 346 "sms-min-sc", 347 "The minimum value of stage count that swing modulo scheduler will generate.", 348 2, 1, 1) 349DEFPARAM(PARAM_SMS_DFA_HISTORY, 350 "sms-dfa-history", 351 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA", 352 0, 0, 0) 353DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD, 354 "sms-loop-average-count-threshold", 355 "A threshold on the average loop count considered by the swing modulo scheduler", 356 0, 0, 0) 357 358DEFPARAM(HOT_BB_COUNT_FRACTION, 359 "hot-bb-count-fraction", 360 "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot", 361 10000, 0, 0) 362DEFPARAM(HOT_BB_FREQUENCY_FRACTION, 363 "hot-bb-frequency-fraction", 364 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot", 365 1000, 0, 0) 366 367DEFPARAM (PARAM_ALIGN_THRESHOLD, 368 "align-threshold", 369 "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment", 370 100, 0, 0) 371 372DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS, 373 "align-loop-iterations", 374 "Loops iterating at least selected number of iterations will get loop alignement.", 375 4, 0, 0) 376 377/* For guessed profiles, the loops having unknown number of iterations 378 are predicted to iterate relatively few (10) times at average. 379 For functions containing one loop with large known number of iterations 380 and other loops having unbounded loops we would end up predicting all 381 the other loops cold that is not usually the case. So we need to artificially 382 flatten the profile. 383 384 We need to cut the maximal predicted iterations to large enough iterations 385 so the loop appears important, but safely within HOT_BB_COUNT_FRACTION 386 range. */ 387 388DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS, 389 "max-predicted-iterations", 390 "The maximum number of loop iterations we predict statically", 391 100, 0, 0) 392DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK, 393 "tracer-dynamic-coverage-feedback", 394 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available", 395 95, 0, 100) 396DEFPARAM(TRACER_DYNAMIC_COVERAGE, 397 "tracer-dynamic-coverage", 398 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available", 399 75, 0, 100) 400DEFPARAM(TRACER_MAX_CODE_GROWTH, 401 "tracer-max-code-growth", 402 "Maximal code growth caused by tail duplication (in percent)", 403 100, 0, 0) 404DEFPARAM(TRACER_MIN_BRANCH_RATIO, 405 "tracer-min-branch-ratio", 406 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)", 407 10, 0, 100) 408DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK, 409 "tracer-min-branch-probability-feedback", 410 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available", 411 80, 0, 100) 412DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY, 413 "tracer-min-branch-probability", 414 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available", 415 50, 0, 100) 416 417/* The maximum number of incoming edges to consider for crossjumping. */ 418DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES, 419 "max-crossjump-edges", 420 "The maximum number of incoming edges to consider for crossjumping", 421 100, 0, 0) 422 423/* The minimum number of matching instructions to consider for crossjumping. */ 424DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS, 425 "min-crossjump-insns", 426 "The minimum number of matching instructions to consider for crossjumping", 427 5, 0, 0) 428 429/* The maximum number expansion factor when copying basic blocks. */ 430DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS, 431 "max-grow-copy-bb-insns", 432 "The maximum expansion factor when copying basic blocks", 433 8, 0, 0) 434 435/* The maximum number of insns to duplicate when unfactoring computed gotos. */ 436DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS, 437 "max-goto-duplication-insns", 438 "The maximum number of insns to duplicate when unfactoring computed gotos", 439 8, 0, 0) 440 441/* The maximum length of path considered in cse. */ 442DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH, 443 "max-cse-path-length", 444 "The maximum length of path considered in cse", 445 10, 0, 0) 446DEFPARAM(PARAM_MAX_CSE_INSNS, 447 "max-cse-insns", 448 "The maximum instructions CSE process before flushing", 449 1000, 0, 0) 450 451/* The cost of expression in loop invariant motion that is considered 452 expensive. */ 453DEFPARAM(PARAM_LIM_EXPENSIVE, 454 "lim-expensive", 455 "The minimum cost of an expensive expression in the loop invariant motion", 456 20, 0, 0) 457 458/* Bound on number of candidates for induction variables below that 459 all candidates are considered for each use in induction variable 460 optimizations. */ 461 462DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND, 463 "iv-consider-all-candidates-bound", 464 "Bound on number of candidates below that all candidates are considered in iv optimizations", 465 30, 0, 0) 466 467/* The induction variable optimizations give up on loops that contain more 468 induction variable uses. */ 469 470DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES, 471 "iv-max-considered-uses", 472 "Bound on number of iv uses in loop optimized in iv optimizations", 473 250, 0, 0) 474 475/* If there are at most this number of ivs in the set, try removing unnecessary 476 ivs from the set always. */ 477 478DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND, 479 "iv-always-prune-cand-set-bound", 480 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization", 481 10, 0, 0) 482 483DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE, 484 "scev-max-expr-size", 485 "Bound on size of expressions used in the scalar evolutions analyzer", 486 100, 0, 0) 487 488DEFPARAM(PARAM_SCEV_MAX_EXPR_COMPLEXITY, 489 "scev-max-expr-complexity", 490 "Bound on the complexity of the expressions in the scalar evolutions analyzer", 491 10, 0, 0) 492 493DEFPARAM(PARAM_OMEGA_MAX_VARS, 494 "omega-max-vars", 495 "Bound on the number of variables in Omega constraint systems", 496 128, 0, 0) 497 498DEFPARAM(PARAM_OMEGA_MAX_GEQS, 499 "omega-max-geqs", 500 "Bound on the number of inequalities in Omega constraint systems", 501 256, 0, 0) 502 503DEFPARAM(PARAM_OMEGA_MAX_EQS, 504 "omega-max-eqs", 505 "Bound on the number of equalities in Omega constraint systems", 506 128, 0, 0) 507 508DEFPARAM(PARAM_OMEGA_MAX_WILD_CARDS, 509 "omega-max-wild-cards", 510 "Bound on the number of wild cards in Omega constraint systems", 511 18, 0, 0) 512 513DEFPARAM(PARAM_OMEGA_HASH_TABLE_SIZE, 514 "omega-hash-table-size", 515 "Bound on the size of the hash table in Omega constraint systems", 516 550, 0, 0) 517 518DEFPARAM(PARAM_OMEGA_MAX_KEYS, 519 "omega-max-keys", 520 "Bound on the number of keys in Omega constraint systems", 521 500, 0, 0) 522 523DEFPARAM(PARAM_OMEGA_ELIMINATE_REDUNDANT_CONSTRAINTS, 524 "omega-eliminate-redundant-constraints", 525 "When set to 1, use expensive methods to eliminate all redundant constraints", 526 0, 0, 1) 527 528DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS, 529 "vect-max-version-for-alignment-checks", 530 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check", 531 6, 0, 0) 532 533DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS, 534 "vect-max-version-for-alias-checks", 535 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alias check", 536 10, 0, 0) 537 538DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS, 539 "max-cselib-memory-locations", 540 "The maximum memory locations recorded by cselib", 541 500, 0, 0) 542 543#ifdef ENABLE_GC_ALWAYS_COLLECT 544# define GGC_MIN_EXPAND_DEFAULT 0 545# define GGC_MIN_HEAPSIZE_DEFAULT 0 546#else 547# define GGC_MIN_EXPAND_DEFAULT 30 548# define GGC_MIN_HEAPSIZE_DEFAULT 4096 549#endif 550 551DEFPARAM(GGC_MIN_EXPAND, 552 "ggc-min-expand", 553 "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap", 554 GGC_MIN_EXPAND_DEFAULT, 0, 0) 555 556DEFPARAM(GGC_MIN_HEAPSIZE, 557 "ggc-min-heapsize", 558 "Minimum heap size before we start collecting garbage, in kilobytes", 559 GGC_MIN_HEAPSIZE_DEFAULT, 0, 0) 560 561#undef GGC_MIN_EXPAND_DEFAULT 562#undef GGC_MIN_HEAPSIZE_DEFAULT 563 564DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS, 565 "max-reload-search-insns", 566 "The maximum number of instructions to search backward when looking for equivalent reload", 567 100, 0, 0) 568 569DEFPARAM(PARAM_SINK_FREQUENCY_THRESHOLD, 570 "sink-frequency-threshold", 571 "Target block's relative execution frequency (as a percentage) required to sink a statement", 572 75, 0, 100) 573 574DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS, 575 "max-sched-region-blocks", 576 "The maximum number of blocks in a region to be considered for interblock scheduling", 577 10, 0, 0) 578 579DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS, 580 "max-sched-region-insns", 581 "The maximum number of insns in a region to be considered for interblock scheduling", 582 100, 0, 0) 583 584DEFPARAM(PARAM_MAX_PIPELINE_REGION_BLOCKS, 585 "max-pipeline-region-blocks", 586 "The maximum number of blocks in a region to be considered for interblock scheduling", 587 15, 0, 0) 588 589DEFPARAM(PARAM_MAX_PIPELINE_REGION_INSNS, 590 "max-pipeline-region-insns", 591 "The maximum number of insns in a region to be considered for interblock scheduling", 592 200, 0, 0) 593 594DEFPARAM(PARAM_MIN_SPEC_PROB, 595 "min-spec-prob", 596 "The minimum probability of reaching a source block for interblock speculative scheduling", 597 40, 0, 0) 598 599DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS, 600 "max-sched-extend-regions-iters", 601 "The maximum number of iterations through CFG to extend regions", 602 0, 0, 0) 603 604DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY, 605 "max-sched-insn-conflict-delay", 606 "The maximum conflict delay for an insn to be considered for speculative motion", 607 3, 1, 10) 608 609DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF, 610 "sched-spec-prob-cutoff", 611 "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.", 612 40, 0, 100) 613 614DEFPARAM(PARAM_SELSCHED_MAX_LOOKAHEAD, 615 "selsched-max-lookahead", 616 "The maximum size of the lookahead window of selective scheduling", 617 50, 0, 0) 618 619DEFPARAM(PARAM_SELSCHED_MAX_SCHED_TIMES, 620 "selsched-max-sched-times", 621 "Maximum number of times that an insn could be scheduled", 622 2, 0, 0) 623 624DEFPARAM(PARAM_SELSCHED_INSNS_TO_RENAME, 625 "selsched-insns-to-rename", 626 "Maximum number of instructions in the ready list that are considered eligible for renaming", 627 2, 0, 0) 628 629DEFPARAM (PARAM_SCHED_MEM_TRUE_DEP_COST, 630 "sched-mem-true-dep-cost", 631 "Minimal distance between possibly conflicting store and load", 632 1, 0, 0) 633 634DEFPARAM(PARAM_MAX_LAST_VALUE_RTL, 635 "max-last-value-rtl", 636 "The maximum number of RTL nodes that can be recorded as combiner's last value", 637 10000, 0, 0) 638 639/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for 640 {signed,unsigned} integral types. This determines N. 641 Experimentation shows 251 to be a good value that generates the 642 least amount of garbage for allocating the TREE_VEC storage. */ 643DEFPARAM (PARAM_INTEGER_SHARE_LIMIT, 644 "integer-share-limit", 645 "The upper bound for sharing integer constants", 646 251, 2, 2) 647 648/* Incremental SSA updates for virtual operands may be very slow if 649 there is a large number of mappings to process. In those cases, it 650 is faster to rewrite the virtual symbols from scratch as if they 651 had been recently introduced. This heuristic cannot be applied to 652 SSA mappings for real SSA names, only symbols kept in FUD chains. 653 654 PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual 655 mappings that should be registered to trigger the heuristic. 656 657 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between 658 mappings and symbols. If the number of virtual mappings is 659 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of 660 virtual symbols to be updated, then the updater switches to a full 661 update for those symbols. */ 662DEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS, 663 "min-virtual-mappings", 664 "Minimum number of virtual mappings to consider switching to full virtual renames", 665 100, 0, 0) 666 667DEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO, 668 "virtual-mappings-ratio", 669 "Ratio between virtual mappings and virtual symbols to do full virtual renames", 670 3, 0, 0) 671 672DEFPARAM (PARAM_SSP_BUFFER_SIZE, 673 "ssp-buffer-size", 674 "The lower bound for a buffer to be considered for stack smashing protection", 675 8, 1, 0) 676 677/* When we thread through a block we have to make copies of the 678 statements within the block. Clearly for large blocks the code 679 duplication is bad. 680 681 PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number 682 of statements and PHI nodes allowed in a block which is going to 683 be duplicated for thread jumping purposes. 684 685 Some simple analysis showed that more than 99% of the jump 686 threading opportunities are for blocks with less than 15 687 statements. So we can get the benefits of jump threading 688 without excessive code bloat for pathological cases with the 689 throttle set at 15 statements. */ 690DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS, 691 "max-jump-thread-duplication-stmts", 692 "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps", 693 15, 0, 0) 694 695/* This is the maximum number of fields a variable may have before the pointer analysis machinery 696 will stop trying to treat it in a field-sensitive manner. 697 There are programs out there with thousands of fields per structure, and handling them 698 field-sensitively is not worth the cost. */ 699DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE, 700 "max-fields-for-field-sensitive", 701 "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable", 702 0, 0, 0) 703 704DEFPARAM(PARAM_MAX_SCHED_READY_INSNS, 705 "max-sched-ready-insns", 706 "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass", 707 100, 0, 0) 708 709/* This is the maximum number of active local stores RTL DSE will consider. */ 710DEFPARAM (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES, 711 "max-dse-active-local-stores", 712 "Maximum number of active local stores in RTL dead store elimination", 713 5000, 0, 0) 714 715/* Prefetching and cache-optimizations related parameters. Default values are 716 usually set by machine description. */ 717 718/* The number of insns executed before prefetch is completed. */ 719 720DEFPARAM (PARAM_PREFETCH_LATENCY, 721 "prefetch-latency", 722 "The number of insns executed before prefetch is completed", 723 200, 0, 0) 724 725/* The number of prefetches that can run at the same time. */ 726 727DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES, 728 "simultaneous-prefetches", 729 "The number of prefetches that can run at the same time", 730 3, 0, 0) 731 732/* The size of L1 cache in kB. */ 733 734DEFPARAM (PARAM_L1_CACHE_SIZE, 735 "l1-cache-size", 736 "The size of L1 cache", 737 64, 0, 0) 738 739/* The size of L1 cache line in bytes. */ 740 741DEFPARAM (PARAM_L1_CACHE_LINE_SIZE, 742 "l1-cache-line-size", 743 "The size of L1 cache line", 744 32, 0, 0) 745 746/* The size of L2 cache in kB. */ 747 748DEFPARAM (PARAM_L2_CACHE_SIZE, 749 "l2-cache-size", 750 "The size of L2 cache", 751 512, 0, 0) 752 753/* Whether we should use canonical types rather than deep "structural" 754 type checking. Setting this value to 1 (the default) improves 755 compilation performance in the C++ and Objective-C++ front end; 756 this value should only be set to zero to work around bugs in the 757 canonical type system by disabling it. */ 758 759DEFPARAM (PARAM_USE_CANONICAL_TYPES, 760 "use-canonical-types", 761 "Whether to use canonical types", 762 1, 0, 1) 763 764DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH, 765 "max-partial-antic-length", 766 "Maximum length of partial antic set when performing tree pre optimization", 767 100, 0, 0) 768 769/* The following is used as a stop-gap limit for cases where really huge 770 SCCs blow up memory and compile-time use too much. If we hit this limit, 771 SCCVN and such FRE and PRE will be not done at all for the current 772 function. */ 773 774DEFPARAM (PARAM_SCCVN_MAX_SCC_SIZE, 775 "sccvn-max-scc-size", 776 "Maximum size of a SCC before SCCVN stops processing a function", 777 10000, 10, 0) 778 779DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM, 780 "ira-max-loops-num", 781 "Max loops number for regional RA", 782 100, 0, 0) 783 784DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE, 785 "ira-max-conflict-table-size", 786 "Max size of conflict table in MB", 787 1000, 0, 0) 788 789DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS, 790 "ira-loop-reserved-regs", 791 "The number of registers in each class kept unused by loop invariant motion", 792 2, 0, 0) 793 794/* Switch initialization conversion will refuse to create arrays that are 795 bigger than this parameter times the number of switch branches. */ 796 797DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO, 798 "switch-conversion-max-branch-ratio", 799 "The maximum ratio between array size and switch branches for " 800 "a switch conversion to take place", 801 8, 1, 0) 802 803/* Size of tiles when doing loop blocking. */ 804 805DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE, 806 "loop-block-tile-size", 807 "size of tiles for loop blocking", 808 51, 0, 0) 809 810/* Maximal number of parameters that we allow in a SCoP. */ 811 812DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS, 813 "graphite-max-nb-scop-params", 814 "maximum number of parameters in a SCoP", 815 10, 0, 0) 816 817/* Maximal number of basic blocks in the functions analyzed by Graphite. */ 818 819DEFPARAM (PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION, 820 "graphite-max-bbs-per-function", 821 "maximum number of basic blocks per function to be analyzed by Graphite", 822 100, 0, 0) 823 824/* Avoid data dependence analysis on very large loops. */ 825DEFPARAM (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS, 826 "loop-max-datarefs-for-datadeps", 827 "Maximum number of datarefs in loop for building loop data dependencies", 828 1000, 0, 0) 829 830/* Avoid doing loop invariant motion on very large loops. */ 831 832DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP, 833 "loop-invariant-max-bbs-in-loop", 834 "Max basic blocks number in loop for loop invariant motion", 835 10000, 0, 0) 836 837/* Avoid SLP vectorization of large basic blocks. */ 838DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB, 839 "slp-max-insns-in-bb", 840 "Maximum number of instructions in basic block to be considered for SLP vectorization", 841 1000, 0, 0) 842 843DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO, 844 "min-insn-to-prefetch-ratio", 845 "Min. ratio of insns to prefetches to enable prefetching for " 846 "a loop with an unknown trip count", 847 9, 0, 0) 848 849DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO, 850 "prefetch-min-insn-to-mem-ratio", 851 "Min. ratio of insns to mem ops to enable prefetching in a loop", 852 3, 0, 0) 853 854/* Set maximum hash table size for var tracking. */ 855 856DEFPARAM (PARAM_MAX_VARTRACK_SIZE, 857 "max-vartrack-size", 858 "Max. size of var tracking hash tables", 859 50000000, 0, 0) 860 861/* Set maximum recursion depth for var tracking expression expansion 862 and resolution. */ 863 864DEFPARAM (PARAM_MAX_VARTRACK_EXPR_DEPTH, 865 "max-vartrack-expr-depth", 866 "Max. recursion depth for expanding var tracking expressions", 867 12, 0, 0) 868 869/* Set minimum insn uid for non-debug insns. */ 870 871DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID, 872 "min-nondebug-insn-uid", 873 "The minimum UID to be used for a nondebug insn", 874 0, 1, 0) 875 876DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR, 877 "ipa-sra-ptr-growth-factor", 878 "Maximum allowed growth of size of new parameters ipa-sra replaces " 879 "a pointer to an aggregate with", 880 2, 0, 0) 881 882DEFPARAM (PARAM_TM_MAX_AGGREGATE_SIZE, 883 "tm-max-aggregate-size", 884 "Size in bytes after which thread-local aggregates should be " 885 "instrumented with the logging functions instead of save/restore " 886 "pairs", 887 9, 0, 0) 888 889DEFPARAM (PARAM_IPA_CP_VALUE_LIST_SIZE, 890 "ipa-cp-value-list-size", 891 "Maximum size of a list of values associated with each parameter for " 892 "interprocedural constant propagation", 893 8, 0, 0) 894 895DEFPARAM (PARAM_IPA_CP_EVAL_THRESHOLD, 896 "ipa-cp-eval-threshold", 897 "Threshold ipa-cp opportunity evaluation that is still considered " 898 "beneficial to clone.", 899 500, 0, 0) 900 901/* WHOPR partitioning configuration. */ 902 903DEFPARAM (PARAM_LTO_PARTITIONS, 904 "lto-partitions", 905 "Number of partitions the program should be split to", 906 32, 1, 0) 907 908DEFPARAM (MIN_PARTITION_SIZE, 909 "lto-min-partition", 910 "Minimal size of a partition for LTO (in estimated instructions)", 911 1000, 0, 0) 912 913/* Diagnostic parameters. */ 914 915DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP, 916 "cxx-max-namespaces-for-diagnostic-help", 917 "Maximum number of namespaces to search for alternatives when " 918 "name lookup fails", 919 1000, 0, 0) 920 921/* Maximum number of conditional store pairs that can be sunk. */ 922DEFPARAM (PARAM_MAX_STORES_TO_SINK, 923 "max-stores-to-sink", 924 "Maximum number of conditional store pairs that can be sunk", 925 2, 0, 0) 926 927/* Override CASE_VALUES_THRESHOLD of when to switch from doing switch 928 statements via if statements to using a table jump operation. If the value 929 is 0, the default CASE_VALUES_THRESHOLD will be used. */ 930DEFPARAM (PARAM_CASE_VALUES_THRESHOLD, 931 "case-values-threshold", 932 "The smallest number of different values for which it is best to " 933 "use a jump-table instead of a tree of conditional branches, " 934 "if 0, use the default for the machine", 935 0, 0, 0) 936 937/* Data race flags for C++0x memory model compliance. */ 938DEFPARAM (PARAM_ALLOW_LOAD_DATA_RACES, 939 "allow-load-data-races", 940 "Allow new data races on loads to be introduced", 941 1, 0, 1) 942 943DEFPARAM (PARAM_ALLOW_STORE_DATA_RACES, 944 "allow-store-data-races", 945 "Allow new data races on stores to be introduced", 946 1, 0, 1) 947 948DEFPARAM (PARAM_ALLOW_PACKED_LOAD_DATA_RACES, 949 "allow-packed-load-data-races", 950 "Allow new data races on packed data loads to be introduced", 951 1, 0, 1) 952 953DEFPARAM (PARAM_ALLOW_PACKED_STORE_DATA_RACES, 954 "allow-packed-store-data-races", 955 "Allow new data races on packed data stores to be introduced", 956 1, 0, 1) 957 958/* Reassociation width to be used by tree reassoc optimization. */ 959DEFPARAM (PARAM_TREE_REASSOC_WIDTH, 960 "tree-reassoc-width", 961 "Set the maximum number of instructions executed in parallel in " 962 "reassociated tree. If 0, use the target dependent heuristic.", 963 0, 0, 0) 964 965DEFPARAM (PARAM_MAX_TAIL_MERGE_COMPARISONS, 966 "max-tail-merge-comparisons", 967 "Maximum amount of similar bbs to compare a bb with", 968 10, 0, 0) 969 970DEFPARAM (PARAM_MAX_TAIL_MERGE_ITERATIONS, 971 "max-tail-merge-iterations", 972 "Maximum amount of iterations of the pass over a function", 973 2, 0, 0) 974 975/* Maximum number of strings for which strlen optimization pass will 976 track string lenths. */ 977DEFPARAM (PARAM_MAX_TRACKED_STRLENS, 978 "max-tracked-strlens", 979 "Maximum number of strings for which strlen optimization pass will " 980 "track string lengths", 981 1000, 0, 0) 982 983/* 984Local variables: 985mode:c 986End: 987*/ 988