1 /* params.def - Run-time parameters. 2 Copyright (C) 2001-2013 Free Software Foundation, Inc. 3 Written by Mark Mitchell <mark (at) codesourcery.com>. 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 /* This file contains definitions for language-independent 22 parameters. The DEFPARAM macro takes 6 arguments: 23 24 - The enumeral corresponding to this parameter. 25 26 - The name that can be used to set this parameter using the 27 command-line option `--param <name>=<value>'. 28 29 - A help string explaining how the parameter is used. 30 31 - A default value for the parameter. 32 33 - The minimum acceptable value for the parameter. 34 35 - The maximum acceptable value for the parameter (if greater than 36 the minimum). 37 38 Be sure to add an entry to invoke.texi summarizing the parameter. */ 39 40 /* When branch is predicted to be taken with probability lower than this 41 threshold (in percent), then it is considered well predictable. */ 42 DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME, 43 "predictable-branch-outcome", 44 "Maximal estimated outcome of branch considered predictable", 45 2, 0, 50) 46 47 DEFPARAM (PARAM_INLINE_MIN_SPEEDUP, 48 "inline-min-speedup", 49 "The minimal estimated speedup allowing inliner to ignore inline-insns-single and inline-isnsns-auto", 50 10, 0, 0) 51 52 /* The single function inlining limit. This is the maximum size 53 of a function counted in internal gcc instructions (not in 54 real machine instructions) that is eligible for inlining 55 by the tree inliner. 56 The default value is 450. 57 Only functions marked inline (or methods defined in the class 58 definition for C++) are affected by this. 59 There are more restrictions to inlining: If inlined functions 60 call other functions, the already inlined instructions are 61 counted and once the recursive inline limit (see 62 "max-inline-insns" parameter) is exceeded, the acceptable size 63 gets decreased. */ 64 DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE, 65 "max-inline-insns-single", 66 "The maximum number of instructions in a single function eligible for inlining", 67 400, 0, 0) 68 69 /* The single function inlining limit for functions that are 70 inlined by virtue of -finline-functions (-O3). 71 This limit should be chosen to be below or equal to the limit 72 that is applied to functions marked inlined (or defined in the 73 class declaration in C++) given by the "max-inline-insns-single" 74 parameter. 75 The default value is 40. */ 76 DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO, 77 "max-inline-insns-auto", 78 "The maximum number of instructions when automatically inlining", 79 40, 0, 0) 80 81 DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE, 82 "max-inline-insns-recursive", 83 "The maximum number of instructions inline function can grow to via recursive inlining", 84 450, 0, 0) 85 86 DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO, 87 "max-inline-insns-recursive-auto", 88 "The maximum number of instructions non-inline function can grow to via recursive inlining", 89 450, 0, 0) 90 91 DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH, 92 "max-inline-recursive-depth", 93 "The maximum depth of recursive inlining for inline functions", 94 8, 0, 0) 95 96 DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO, 97 "max-inline-recursive-depth-auto", 98 "The maximum depth of recursive inlining for non-inline functions", 99 8, 0, 0) 100 101 DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY, 102 "min-inline-recursive-probability", 103 "Inline recursively only when the probability of call being executed exceeds the parameter", 104 10, 0, 0) 105 106 /* Limit of iterations of early inliner. This basically bounds number of 107 nested indirect calls early inliner can resolve. Deeper chains are still 108 handled by late inlining. */ 109 DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS, 110 "max-early-inliner-iterations", 111 "The maximum number of nested indirect inlining performed by early inliner", 112 1, 0, 0) 113 114 /* Limit on probability of entry BB. */ 115 DEFPARAM (PARAM_COMDAT_SHARING_PROBABILITY, 116 "comdat-sharing-probability", 117 "Probability that COMDAT function will be shared with different compilation unit", 118 20, 0, 0) 119 120 /* Limit on probability of entry BB. */ 121 DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY, 122 "partial-inlining-entry-probability", 123 "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen", 124 70, 0, 0) 125 126 /* Limit the number of expansions created by the variable expansion 127 optimization to avoid register pressure. */ 128 DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS, 129 "max-variable-expansions-in-unroller", 130 "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling", 131 1, 0, 0) 132 133 /* Limit loop autovectorization to loops with large enough iteration count. */ 134 DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND, 135 "min-vect-loop-bound", 136 "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization", 137 1, 1, 0) 138 139 /* The maximum number of instructions to consider when looking for an 140 instruction to fill a delay slot. If more than this arbitrary 141 number of instructions is searched, the time savings from filling 142 the delay slot will be minimal so stop searching. Increasing 143 values mean more aggressive optimization, making the compile time 144 increase with probably small improvement in executable run time. */ 145 DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH, 146 "max-delay-slot-insn-search", 147 "The maximum number of instructions to consider to fill a delay slot", 148 100, 0, 0) 149 150 /* When trying to fill delay slots, the maximum number of instructions 151 to consider when searching for a block with valid live register 152 information. Increasing this arbitrarily chosen value means more 153 aggressive optimization, increasing the compile time. This 154 parameter should be removed when the delay slot code is rewritten 155 to maintain the control-flow graph. */ 156 DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH, 157 "max-delay-slot-live-search", 158 "The maximum number of instructions to consider to find accurate live register information", 159 333, 0, 0) 160 161 /* This parameter limits the number of branch elements that the 162 scheduler will track anti-dependencies through without resetting 163 the tracking mechanism. Large functions with few calls or barriers 164 can generate lists containing many 1000's of dependencies. Generally 165 the compiler either uses all available memory, or runs for far too long. */ 166 DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH, 167 "max-pending-list-length", 168 "The maximum length of scheduling's pending operations list", 169 32, 0, 0) 170 171 /* This parameter limits the number of backtracking attempts when using the 172 haifa scheduler for modulo scheduling. */ 173 DEFPARAM(PARAM_MAX_MODULO_BACKTRACK_ATTEMPTS, 174 "max-modulo-backtrack-attempts", 175 "The maximum number of backtrack attempts the scheduler should make when modulo scheduling a loop", 176 40, 0, 0) 177 178 DEFPARAM(PARAM_LARGE_FUNCTION_INSNS, 179 "large-function-insns", 180 "The size of function body to be considered large", 181 2700, 0, 0) 182 DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH, 183 "large-function-growth", 184 "Maximal growth due to inlining of large function (in percent)", 185 100, 0, 0) 186 DEFPARAM(PARAM_LARGE_UNIT_INSNS, 187 "large-unit-insns", 188 "The size of translation unit to be considered large", 189 10000, 0, 0) 190 DEFPARAM(PARAM_INLINE_UNIT_GROWTH, 191 "inline-unit-growth", 192 "How much can given compilation unit grow because of the inlining (in percent)", 193 30, 0, 0) 194 DEFPARAM(PARAM_IPCP_UNIT_GROWTH, 195 "ipcp-unit-growth", 196 "How much can given compilation unit grow because of the interprocedural constant propagation (in percent)", 197 10, 0, 0) 198 DEFPARAM(PARAM_EARLY_INLINING_INSNS, 199 "early-inlining-insns", 200 "Maximal estimated growth of function body caused by early inlining of single call", 201 11, 0, 0) 202 DEFPARAM(PARAM_LARGE_STACK_FRAME, 203 "large-stack-frame", 204 "The size of stack frame to be considered large", 205 256, 0, 0) 206 DEFPARAM(PARAM_STACK_FRAME_GROWTH, 207 "large-stack-frame-growth", 208 "Maximal stack frame growth due to inlining (in percent)", 209 1000, 0, 0) 210 211 /* The GCSE optimization will be disabled if it would require 212 significantly more memory than this value. */ 213 DEFPARAM(PARAM_MAX_GCSE_MEMORY, 214 "max-gcse-memory", 215 "The maximum amount of memory to be allocated by GCSE", 216 50 * 1024 * 1024, 0, 0) 217 218 /* The GCSE optimization of an expression will avoided if the ratio of 219 insertions to deletions is greater than this value. */ 220 DEFPARAM(PARAM_MAX_GCSE_INSERTION_RATIO, 221 "max-gcse-insertion-ratio", 222 "The maximum ratio of insertions to deletions of expressions in GCSE", 223 20, 0, 0) 224 225 /* This is the threshold ratio when to perform partial redundancy 226 elimination after reload. We perform partial redundancy elimination 227 when the following holds: 228 (Redundant load execution count) 229 ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION 230 (Added loads execution count) */ 231 DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION, 232 "gcse-after-reload-partial-fraction", 233 "The threshold ratio for performing partial redundancy elimination after reload", 234 3, 0, 0) 235 /* This is the threshold ratio of the critical edges execution count compared to 236 the redundant loads execution count that permits performing the load 237 redundancy elimination in gcse after reload. */ 238 DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION, 239 "gcse-after-reload-critical-fraction", 240 "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload", 241 10, 0, 0) 242 243 /* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor 244 to calculate maximum distance for which an expression is allowed to move 245 from its rtx_cost. */ 246 DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO, 247 "gcse-cost-distance-ratio", 248 "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations", 249 10, 0, 0) 250 /* GCSE won't restrict distance for which an expression with rtx_cost greater 251 than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move. */ 252 DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST, 253 "gcse-unrestricted-cost", 254 "Cost at which GCSE optimizations will not constraint the distance an expression can travel", 255 3, 0, 0) 256 257 /* How deep from a given basic block the dominator tree should be searched 258 for expressions to hoist to the block. The value of 0 will avoid limiting 259 the search. */ 260 DEFPARAM(PARAM_MAX_HOIST_DEPTH, 261 "max-hoist-depth", 262 "Maximum depth of search in the dominator tree for expressions to hoist", 263 30, 0, 0) 264 265 /* This parameter limits the number of insns in a loop that will be unrolled, 266 and by how much the loop is unrolled. 267 268 This limit should be at most half of the peeling limits: loop unroller 269 decides to not unroll loops that iterate fewer than 2*number of allowed 270 unrollings and thus we would have loops that are neither peeled or unrolled 271 otherwise. */ 272 DEFPARAM(PARAM_MAX_UNROLLED_INSNS, 273 "max-unrolled-insns", 274 "The maximum number of instructions to consider to unroll in a loop", 275 200, 0, 0) 276 /* This parameter limits how many times the loop is unrolled depending 277 on number of insns really executed in each iteration. */ 278 DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS, 279 "max-average-unrolled-insns", 280 "The maximum number of instructions to consider to unroll in a loop on average", 281 80, 0, 0) 282 /* The maximum number of unrollings of a single loop. */ 283 DEFPARAM(PARAM_MAX_UNROLL_TIMES, 284 "max-unroll-times", 285 "The maximum number of unrollings of a single loop", 286 8, 0, 0) 287 /* The maximum number of insns of a peeled loop. */ 288 DEFPARAM(PARAM_MAX_PEELED_INSNS, 289 "max-peeled-insns", 290 "The maximum number of insns of a peeled loop", 291 100, 0, 0) 292 /* The maximum number of peelings of a single loop. */ 293 DEFPARAM(PARAM_MAX_PEEL_TIMES, 294 "max-peel-times", 295 "The maximum number of peelings of a single loop", 296 16, 0, 0) 297 /* The maximum number of peelings of a single loop that is peeled completely. */ 298 DEFPARAM(PARAM_MAX_PEEL_BRANCHES, 299 "max-peel-branches", 300 "The maximum number of branches on the path through the peeled sequence", 301 32, 0, 0) 302 /* The maximum number of insns of a peeled loop. */ 303 DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS, 304 "max-completely-peeled-insns", 305 "The maximum number of insns of a completely peeled loop", 306 100, 0, 0) 307 /* The maximum number of peelings of a single loop that is peeled completely. */ 308 DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES, 309 "max-completely-peel-times", 310 "The maximum number of peelings of a single loop that is peeled completely", 311 16, 0, 0) 312 /* The maximum number of insns of a peeled loop that rolls only once. */ 313 DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS, 314 "max-once-peeled-insns", 315 "The maximum number of insns of a peeled loop that rolls only once", 316 400, 0, 0) 317 /* The maximum depth of a loop nest we completely peel. */ 318 DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS, 319 "max-completely-peel-loop-nest-depth", 320 "The maximum depth of a loop nest we completely peel", 321 8, 0, 0) 322 323 /* The maximum number of insns of an unswitched loop. */ 324 DEFPARAM(PARAM_MAX_UNSWITCH_INSNS, 325 "max-unswitch-insns", 326 "The maximum number of insns of an unswitched loop", 327 50, 0, 0) 328 /* The maximum level of recursion in unswitch_single_loop. */ 329 DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL, 330 "max-unswitch-level", 331 "The maximum number of unswitchings in a single loop", 332 3, 0, 0) 333 334 /* The maximum number of iterations of a loop the brute force algorithm 335 for analysis of # of iterations of the loop tries to evaluate. */ 336 DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK, 337 "max-iterations-to-track", 338 "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates", 339 1000, 0, 0) 340 /* A cutoff to avoid costly computations of the number of iterations in 341 the doloop transformation. */ 342 DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST, 343 "max-iterations-computation-cost", 344 "Bound on the cost of an expression to compute the number of iterations", 345 10, 0, 0) 346 347 /* This parameter is used to tune SMS MAX II calculations. */ 348 DEFPARAM(PARAM_SMS_MAX_II_FACTOR, 349 "sms-max-ii-factor", 350 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop", 351 100, 0, 0) 352 /* The minimum value of stage count that swing modulo scheduler will generate. */ 353 DEFPARAM(PARAM_SMS_MIN_SC, 354 "sms-min-sc", 355 "The minimum value of stage count that swing modulo scheduler will generate.", 356 2, 1, 1) 357 DEFPARAM(PARAM_SMS_DFA_HISTORY, 358 "sms-dfa-history", 359 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA", 360 0, 0, 0) 361 DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD, 362 "sms-loop-average-count-threshold", 363 "A threshold on the average loop count considered by the swing modulo scheduler", 364 0, 0, 0) 365 366 DEFPARAM(HOT_BB_COUNT_WS_PERMILLE, 367 "hot-bb-count-ws-permille", 368 "A basic block profile count is considered hot if it contributes to " 369 "the given permillage of the entire profiled execution", 370 999, 0, 1000) 371 DEFPARAM(HOT_BB_FREQUENCY_FRACTION, 372 "hot-bb-frequency-fraction", 373 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot", 374 1000, 0, 0) 375 376 DEFPARAM (PARAM_ALIGN_THRESHOLD, 377 "align-threshold", 378 "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment", 379 100, 1, 0) 380 381 DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS, 382 "align-loop-iterations", 383 "Loops iterating at least selected number of iterations will get loop alignement.", 384 4, 0, 0) 385 386 /* For guessed profiles, the loops having unknown number of iterations 387 are predicted to iterate relatively few (10) times at average. 388 For functions containing one loop with large known number of iterations 389 and other loops having unbounded loops we would end up predicting all 390 the other loops cold that is not usually the case. So we need to artificially 391 flatten the profile. 392 393 We need to cut the maximal predicted iterations to large enough iterations 394 so the loop appears important, but safely within maximum hotness 395 range. */ 396 397 DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS, 398 "max-predicted-iterations", 399 "The maximum number of loop iterations we predict statically", 400 100, 0, 0) 401 DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK, 402 "tracer-dynamic-coverage-feedback", 403 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available", 404 95, 0, 100) 405 DEFPARAM(TRACER_DYNAMIC_COVERAGE, 406 "tracer-dynamic-coverage", 407 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available", 408 75, 0, 100) 409 DEFPARAM(TRACER_MAX_CODE_GROWTH, 410 "tracer-max-code-growth", 411 "Maximal code growth caused by tail duplication (in percent)", 412 100, 0, 0) 413 DEFPARAM(TRACER_MIN_BRANCH_RATIO, 414 "tracer-min-branch-ratio", 415 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)", 416 10, 0, 100) 417 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK, 418 "tracer-min-branch-probability-feedback", 419 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available", 420 80, 0, 100) 421 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY, 422 "tracer-min-branch-probability", 423 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available", 424 50, 0, 100) 425 426 /* The maximum number of incoming edges to consider for crossjumping. */ 427 DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES, 428 "max-crossjump-edges", 429 "The maximum number of incoming edges to consider for crossjumping", 430 100, 0, 0) 431 432 /* The minimum number of matching instructions to consider for crossjumping. */ 433 DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS, 434 "min-crossjump-insns", 435 "The minimum number of matching instructions to consider for crossjumping", 436 5, 1, 0) 437 438 /* The maximum number expansion factor when copying basic blocks. */ 439 DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS, 440 "max-grow-copy-bb-insns", 441 "The maximum expansion factor when copying basic blocks", 442 8, 0, 0) 443 444 /* The maximum number of insns to duplicate when unfactoring computed gotos. */ 445 DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS, 446 "max-goto-duplication-insns", 447 "The maximum number of insns to duplicate when unfactoring computed gotos", 448 8, 0, 0) 449 450 /* The maximum length of path considered in cse. */ 451 DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH, 452 "max-cse-path-length", 453 "The maximum length of path considered in cse", 454 10, 1, 0) 455 DEFPARAM(PARAM_MAX_CSE_INSNS, 456 "max-cse-insns", 457 "The maximum instructions CSE process before flushing", 458 1000, 0, 0) 459 460 /* The cost of expression in loop invariant motion that is considered 461 expensive. */ 462 DEFPARAM(PARAM_LIM_EXPENSIVE, 463 "lim-expensive", 464 "The minimum cost of an expensive expression in the loop invariant motion", 465 20, 0, 0) 466 467 /* Bound on number of candidates for induction variables below that 468 all candidates are considered for each use in induction variable 469 optimizations. */ 470 471 DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND, 472 "iv-consider-all-candidates-bound", 473 "Bound on number of candidates below that all candidates are considered in iv optimizations", 474 30, 0, 0) 475 476 /* The induction variable optimizations give up on loops that contain more 477 induction variable uses. */ 478 479 DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES, 480 "iv-max-considered-uses", 481 "Bound on number of iv uses in loop optimized in iv optimizations", 482 250, 0, 0) 483 484 /* If there are at most this number of ivs in the set, try removing unnecessary 485 ivs from the set always. */ 486 487 DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND, 488 "iv-always-prune-cand-set-bound", 489 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization", 490 10, 0, 0) 491 492 DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE, 493 "scev-max-expr-size", 494 "Bound on size of expressions used in the scalar evolutions analyzer", 495 100, 0, 0) 496 497 DEFPARAM(PARAM_SCEV_MAX_EXPR_COMPLEXITY, 498 "scev-max-expr-complexity", 499 "Bound on the complexity of the expressions in the scalar evolutions analyzer", 500 10, 0, 0) 501 502 DEFPARAM(PARAM_OMEGA_MAX_VARS, 503 "omega-max-vars", 504 "Bound on the number of variables in Omega constraint systems", 505 128, 0, 0) 506 507 DEFPARAM(PARAM_OMEGA_MAX_GEQS, 508 "omega-max-geqs", 509 "Bound on the number of inequalities in Omega constraint systems", 510 256, 0, 0) 511 512 DEFPARAM(PARAM_OMEGA_MAX_EQS, 513 "omega-max-eqs", 514 "Bound on the number of equalities in Omega constraint systems", 515 128, 0, 0) 516 517 DEFPARAM(PARAM_OMEGA_MAX_WILD_CARDS, 518 "omega-max-wild-cards", 519 "Bound on the number of wild cards in Omega constraint systems", 520 18, 0, 0) 521 522 DEFPARAM(PARAM_OMEGA_HASH_TABLE_SIZE, 523 "omega-hash-table-size", 524 "Bound on the size of the hash table in Omega constraint systems", 525 550, 0, 0) 526 527 DEFPARAM(PARAM_OMEGA_MAX_KEYS, 528 "omega-max-keys", 529 "Bound on the number of keys in Omega constraint systems", 530 500, 0, 0) 531 532 DEFPARAM(PARAM_OMEGA_ELIMINATE_REDUNDANT_CONSTRAINTS, 533 "omega-eliminate-redundant-constraints", 534 "When set to 1, use expensive methods to eliminate all redundant constraints", 535 0, 0, 1) 536 537 DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS, 538 "vect-max-version-for-alignment-checks", 539 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check", 540 6, 0, 0) 541 542 DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS, 543 "vect-max-version-for-alias-checks", 544 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alias check", 545 10, 0, 0) 546 547 DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS, 548 "max-cselib-memory-locations", 549 "The maximum memory locations recorded by cselib", 550 500, 0, 0) 551 552 #ifdef ENABLE_GC_ALWAYS_COLLECT 553 # define GGC_MIN_EXPAND_DEFAULT 0 554 # define GGC_MIN_HEAPSIZE_DEFAULT 0 555 #else 556 # define GGC_MIN_EXPAND_DEFAULT 30 557 # define GGC_MIN_HEAPSIZE_DEFAULT 4096 558 #endif 559 560 DEFPARAM(GGC_MIN_EXPAND, 561 "ggc-min-expand", 562 "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap", 563 GGC_MIN_EXPAND_DEFAULT, 0, 0) 564 565 DEFPARAM(GGC_MIN_HEAPSIZE, 566 "ggc-min-heapsize", 567 "Minimum heap size before we start collecting garbage, in kilobytes", 568 GGC_MIN_HEAPSIZE_DEFAULT, 0, 0) 569 570 #undef GGC_MIN_EXPAND_DEFAULT 571 #undef GGC_MIN_HEAPSIZE_DEFAULT 572 573 DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS, 574 "max-reload-search-insns", 575 "The maximum number of instructions to search backward when looking for equivalent reload", 576 100, 0, 0) 577 578 DEFPARAM(PARAM_SINK_FREQUENCY_THRESHOLD, 579 "sink-frequency-threshold", 580 "Target block's relative execution frequency (as a percentage) required to sink a statement", 581 75, 0, 100) 582 583 DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS, 584 "max-sched-region-blocks", 585 "The maximum number of blocks in a region to be considered for interblock scheduling", 586 10, 0, 0) 587 588 DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS, 589 "max-sched-region-insns", 590 "The maximum number of insns in a region to be considered for interblock scheduling", 591 100, 0, 0) 592 593 DEFPARAM(PARAM_MAX_PIPELINE_REGION_BLOCKS, 594 "max-pipeline-region-blocks", 595 "The maximum number of blocks in a region to be considered for interblock scheduling", 596 15, 0, 0) 597 598 DEFPARAM(PARAM_MAX_PIPELINE_REGION_INSNS, 599 "max-pipeline-region-insns", 600 "The maximum number of insns in a region to be considered for interblock scheduling", 601 200, 0, 0) 602 603 DEFPARAM(PARAM_MIN_SPEC_PROB, 604 "min-spec-prob", 605 "The minimum probability of reaching a source block for interblock speculative scheduling", 606 40, 0, 0) 607 608 DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS, 609 "max-sched-extend-regions-iters", 610 "The maximum number of iterations through CFG to extend regions", 611 0, 0, 0) 612 613 DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY, 614 "max-sched-insn-conflict-delay", 615 "The maximum conflict delay for an insn to be considered for speculative motion", 616 3, 1, 10) 617 618 DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF, 619 "sched-spec-prob-cutoff", 620 "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.", 621 40, 0, 100) 622 623 DEFPARAM(PARAM_SCHED_STATE_EDGE_PROB_CUTOFF, 624 "sched-state-edge-prob-cutoff", 625 "The minimum probability an edge must have for the scheduler to save its state across it.", 626 10, 0, 100) 627 628 DEFPARAM(PARAM_SELSCHED_MAX_LOOKAHEAD, 629 "selsched-max-lookahead", 630 "The maximum size of the lookahead window of selective scheduling", 631 50, 0, 0) 632 633 DEFPARAM(PARAM_SELSCHED_MAX_SCHED_TIMES, 634 "selsched-max-sched-times", 635 "Maximum number of times that an insn could be scheduled", 636 2, 0, 0) 637 638 DEFPARAM(PARAM_SELSCHED_INSNS_TO_RENAME, 639 "selsched-insns-to-rename", 640 "Maximum number of instructions in the ready list that are considered eligible for renaming", 641 2, 0, 0) 642 643 DEFPARAM (PARAM_SCHED_MEM_TRUE_DEP_COST, 644 "sched-mem-true-dep-cost", 645 "Minimal distance between possibly conflicting store and load", 646 1, 0, 0) 647 648 DEFPARAM(PARAM_MAX_LAST_VALUE_RTL, 649 "max-last-value-rtl", 650 "The maximum number of RTL nodes that can be recorded as combiner's last value", 651 10000, 0, 0) 652 653 /* INTEGER_CST nodes are shared for values [{-1,0} .. N) for 654 {signed,unsigned} integral types. This determines N. 655 Experimentation shows 251 to be a good value that generates the 656 least amount of garbage for allocating the TREE_VEC storage. */ 657 DEFPARAM (PARAM_INTEGER_SHARE_LIMIT, 658 "integer-share-limit", 659 "The upper bound for sharing integer constants", 660 251, 2, 2) 661 662 DEFPARAM (PARAM_SSP_BUFFER_SIZE, 663 "ssp-buffer-size", 664 "The lower bound for a buffer to be considered for stack smashing protection", 665 8, 1, 0) 666 667 /* When we thread through a block we have to make copies of the 668 statements within the block. Clearly for large blocks the code 669 duplication is bad. 670 671 PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number 672 of statements and PHI nodes allowed in a block which is going to 673 be duplicated for thread jumping purposes. 674 675 Some simple analysis showed that more than 99% of the jump 676 threading opportunities are for blocks with less than 15 677 statements. So we can get the benefits of jump threading 678 without excessive code bloat for pathological cases with the 679 throttle set at 15 statements. */ 680 DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS, 681 "max-jump-thread-duplication-stmts", 682 "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps", 683 15, 0, 0) 684 685 /* This is the maximum number of fields a variable may have before the pointer analysis machinery 686 will stop trying to treat it in a field-sensitive manner. 687 There are programs out there with thousands of fields per structure, and handling them 688 field-sensitively is not worth the cost. */ 689 DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE, 690 "max-fields-for-field-sensitive", 691 "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable", 692 0, 0, 0) 693 694 DEFPARAM(PARAM_MAX_SCHED_READY_INSNS, 695 "max-sched-ready-insns", 696 "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass", 697 100, 0, 0) 698 699 /* This is the maximum number of active local stores RTL DSE will consider. */ 700 DEFPARAM (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES, 701 "max-dse-active-local-stores", 702 "Maximum number of active local stores in RTL dead store elimination", 703 5000, 0, 0) 704 705 /* Prefetching and cache-optimizations related parameters. Default values are 706 usually set by machine description. */ 707 708 /* The number of insns executed before prefetch is completed. */ 709 710 DEFPARAM (PARAM_PREFETCH_LATENCY, 711 "prefetch-latency", 712 "The number of insns executed before prefetch is completed", 713 200, 0, 0) 714 715 /* The number of prefetches that can run at the same time. */ 716 717 DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES, 718 "simultaneous-prefetches", 719 "The number of prefetches that can run at the same time", 720 3, 0, 0) 721 722 /* The size of L1 cache in kB. */ 723 724 DEFPARAM (PARAM_L1_CACHE_SIZE, 725 "l1-cache-size", 726 "The size of L1 cache", 727 64, 0, 0) 728 729 /* The size of L1 cache line in bytes. */ 730 731 DEFPARAM (PARAM_L1_CACHE_LINE_SIZE, 732 "l1-cache-line-size", 733 "The size of L1 cache line", 734 32, 0, 0) 735 736 /* The size of L2 cache in kB. */ 737 738 DEFPARAM (PARAM_L2_CACHE_SIZE, 739 "l2-cache-size", 740 "The size of L2 cache", 741 512, 0, 0) 742 743 /* Whether we should use canonical types rather than deep "structural" 744 type checking. Setting this value to 1 (the default) improves 745 compilation performance in the C++ and Objective-C++ front end; 746 this value should only be set to zero to work around bugs in the 747 canonical type system by disabling it. */ 748 749 DEFPARAM (PARAM_USE_CANONICAL_TYPES, 750 "use-canonical-types", 751 "Whether to use canonical types", 752 1, 0, 1) 753 754 DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH, 755 "max-partial-antic-length", 756 "Maximum length of partial antic set when performing tree pre optimization", 757 100, 0, 0) 758 759 /* The following is used as a stop-gap limit for cases where really huge 760 SCCs blow up memory and compile-time use too much. If we hit this limit, 761 SCCVN and such FRE and PRE will be not done at all for the current 762 function. */ 763 764 DEFPARAM (PARAM_SCCVN_MAX_SCC_SIZE, 765 "sccvn-max-scc-size", 766 "Maximum size of a SCC before SCCVN stops processing a function", 767 10000, 10, 0) 768 769 /* The following is used as a stop-gap limit for cases where really huge 770 functions blow up compile-time use too much. It limits the number of 771 alias-queries we do for finding common subexpressions for memory loads and 772 stores. The number of alias-queries is otherwise limited by the number of 773 stores on paths to function entry. */ 774 775 DEFPARAM (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS, 776 "sccvn-max-alias-queries-per-access", 777 "Maximum number of disambiguations to perform per memory access", 778 1000, 0, 0) 779 780 DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM, 781 "ira-max-loops-num", 782 "Max loops number for regional RA", 783 100, 0, 0) 784 785 DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE, 786 "ira-max-conflict-table-size", 787 "Max size of conflict table in MB", 788 1000, 0, 0) 789 790 DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS, 791 "ira-loop-reserved-regs", 792 "The number of registers in each class kept unused by loop invariant motion", 793 2, 0, 0) 794 795 /* Switch initialization conversion will refuse to create arrays that are 796 bigger than this parameter times the number of switch branches. */ 797 798 DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO, 799 "switch-conversion-max-branch-ratio", 800 "The maximum ratio between array size and switch branches for " 801 "a switch conversion to take place", 802 8, 1, 0) 803 804 /* Size of tiles when doing loop blocking. */ 805 806 DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE, 807 "loop-block-tile-size", 808 "size of tiles for loop blocking", 809 51, 0, 0) 810 811 /* Maximal number of parameters that we allow in a SCoP. */ 812 813 DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS, 814 "graphite-max-nb-scop-params", 815 "maximum number of parameters in a SCoP", 816 10, 0, 0) 817 818 /* Maximal number of basic blocks in the functions analyzed by Graphite. */ 819 820 DEFPARAM (PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION, 821 "graphite-max-bbs-per-function", 822 "maximum number of basic blocks per function to be analyzed by Graphite", 823 100, 0, 0) 824 825 /* Avoid data dependence analysis on very large loops. */ 826 DEFPARAM (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS, 827 "loop-max-datarefs-for-datadeps", 828 "Maximum number of datarefs in loop for building loop data dependencies", 829 1000, 0, 0) 830 831 /* Avoid doing loop invariant motion on very large loops. */ 832 833 DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP, 834 "loop-invariant-max-bbs-in-loop", 835 "Max basic blocks number in loop for loop invariant motion", 836 10000, 0, 0) 837 838 /* Avoid SLP vectorization of large basic blocks. */ 839 DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB, 840 "slp-max-insns-in-bb", 841 "Maximum number of instructions in basic block to be considered for SLP vectorization", 842 1000, 0, 0) 843 844 DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO, 845 "min-insn-to-prefetch-ratio", 846 "Min. ratio of insns to prefetches to enable prefetching for " 847 "a loop with an unknown trip count", 848 9, 0, 0) 849 850 DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO, 851 "prefetch-min-insn-to-mem-ratio", 852 "Min. ratio of insns to mem ops to enable prefetching in a loop", 853 3, 0, 0) 854 855 /* Set maximum hash table size for var tracking. */ 856 857 DEFPARAM (PARAM_MAX_VARTRACK_SIZE, 858 "max-vartrack-size", 859 "Max. size of var tracking hash tables", 860 50000000, 0, 0) 861 862 /* Set maximum recursion depth for var tracking expression expansion 863 and resolution. */ 864 865 DEFPARAM (PARAM_MAX_VARTRACK_EXPR_DEPTH, 866 "max-vartrack-expr-depth", 867 "Max. recursion depth for expanding var tracking expressions", 868 12, 0, 0) 869 870 /* Set maximum length of value location list for which var tracking 871 should add reverse operations. */ 872 873 DEFPARAM (PARAM_MAX_VARTRACK_REVERSE_OP_SIZE, 874 "max-vartrack-reverse-op-size", 875 "Max. size of loc list for which reverse ops should be added", 876 50, 0, 0) 877 878 /* Set minimum insn uid for non-debug insns. */ 879 880 DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID, 881 "min-nondebug-insn-uid", 882 "The minimum UID to be used for a nondebug insn", 883 0, 1, 0) 884 885 DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR, 886 "ipa-sra-ptr-growth-factor", 887 "Maximum allowed growth of size of new parameters ipa-sra replaces " 888 "a pointer to an aggregate with", 889 2, 0, 0) 890 891 DEFPARAM (PARAM_TM_MAX_AGGREGATE_SIZE, 892 "tm-max-aggregate-size", 893 "Size in bytes after which thread-local aggregates should be " 894 "instrumented with the logging functions instead of save/restore " 895 "pairs", 896 9, 0, 0) 897 898 DEFPARAM (PARAM_IPA_CP_VALUE_LIST_SIZE, 899 "ipa-cp-value-list-size", 900 "Maximum size of a list of values associated with each parameter for " 901 "interprocedural constant propagation", 902 8, 0, 0) 903 904 DEFPARAM (PARAM_IPA_CP_EVAL_THRESHOLD, 905 "ipa-cp-eval-threshold", 906 "Threshold ipa-cp opportunity evaluation that is still considered " 907 "beneficial to clone.", 908 500, 0, 0) 909 910 DEFPARAM (PARAM_IPA_MAX_AGG_ITEMS, 911 "ipa-max-agg-items", 912 "Maximum number of aggregate content items for a parameter in " 913 "jump functions and lattices", 914 16, 0, 0) 915 916 DEFPARAM (PARAM_IPA_CP_LOOP_HINT_BONUS, 917 "ipa-cp-loop-hint-bonus", 918 "Compile-time bonus IPA-CP assigns to candidates which make loop " 919 "bounds or strides known.", 920 64, 0, 0) 921 922 /* WHOPR partitioning configuration. */ 923 924 DEFPARAM (PARAM_LTO_PARTITIONS, 925 "lto-partitions", 926 "Number of partitions the program should be split to", 927 32, 1, 0) 928 929 DEFPARAM (MIN_PARTITION_SIZE, 930 "lto-min-partition", 931 "Minimal size of a partition for LTO (in estimated instructions)", 932 1000, 0, 0) 933 934 /* Diagnostic parameters. */ 935 936 DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP, 937 "cxx-max-namespaces-for-diagnostic-help", 938 "Maximum number of namespaces to search for alternatives when " 939 "name lookup fails", 940 1000, 0, 0) 941 942 /* Maximum number of conditional store pairs that can be sunk. */ 943 DEFPARAM (PARAM_MAX_STORES_TO_SINK, 944 "max-stores-to-sink", 945 "Maximum number of conditional store pairs that can be sunk", 946 2, 0, 0) 947 948 /* Override CASE_VALUES_THRESHOLD of when to switch from doing switch 949 statements via if statements to using a table jump operation. If the value 950 is 0, the default CASE_VALUES_THRESHOLD will be used. */ 951 DEFPARAM (PARAM_CASE_VALUES_THRESHOLD, 952 "case-values-threshold", 953 "The smallest number of different values for which it is best to " 954 "use a jump-table instead of a tree of conditional branches, " 955 "if 0, use the default for the machine", 956 0, 0, 0) 957 958 /* Data race flags for C++0x memory model compliance. */ 959 DEFPARAM (PARAM_ALLOW_LOAD_DATA_RACES, 960 "allow-load-data-races", 961 "Allow new data races on loads to be introduced", 962 1, 0, 1) 963 964 DEFPARAM (PARAM_ALLOW_STORE_DATA_RACES, 965 "allow-store-data-races", 966 "Allow new data races on stores to be introduced", 967 1, 0, 1) 968 969 DEFPARAM (PARAM_ALLOW_PACKED_LOAD_DATA_RACES, 970 "allow-packed-load-data-races", 971 "Allow new data races on packed data loads to be introduced", 972 1, 0, 1) 973 974 DEFPARAM (PARAM_ALLOW_PACKED_STORE_DATA_RACES, 975 "allow-packed-store-data-races", 976 "Allow new data races on packed data stores to be introduced", 977 1, 0, 1) 978 979 /* Reassociation width to be used by tree reassoc optimization. */ 980 DEFPARAM (PARAM_TREE_REASSOC_WIDTH, 981 "tree-reassoc-width", 982 "Set the maximum number of instructions executed in parallel in " 983 "reassociated tree. If 0, use the target dependent heuristic.", 984 0, 0, 0) 985 986 DEFPARAM (PARAM_MAX_TAIL_MERGE_COMPARISONS, 987 "max-tail-merge-comparisons", 988 "Maximum amount of similar bbs to compare a bb with", 989 10, 0, 0) 990 991 DEFPARAM (PARAM_MAX_TAIL_MERGE_ITERATIONS, 992 "max-tail-merge-iterations", 993 "Maximum amount of iterations of the pass over a function", 994 2, 0, 0) 995 996 /* Maximum number of strings for which strlen optimization pass will 997 track string lenths. */ 998 DEFPARAM (PARAM_MAX_TRACKED_STRLENS, 999 "max-tracked-strlens", 1000 "Maximum number of strings for which strlen optimization pass will " 1001 "track string lengths", 1002 1000, 0, 0) 1003 1004 /* Keep this in sync with the sched_pressure_algorithm enum. */ 1005 DEFPARAM (PARAM_SCHED_PRESSURE_ALGORITHM, 1006 "sched-pressure-algorithm", 1007 "Which -fsched-pressure algorithm to apply", 1008 1, 1, 2) 1009 1010 /* Maximum length of candidate scans in straight-line strength reduction. */ 1011 DEFPARAM (PARAM_MAX_SLSR_CANDIDATE_SCAN, 1012 "max-slsr-cand-scan", 1013 "Maximum length of candidate scans for straight-line " 1014 "strength reduction", 1015 50, 1, 999999) 1016 1017 DEFPARAM (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS, 1018 "uninit-control-dep-attempts", 1019 "Maximum number of nested calls to search for control dependencies " 1020 "during uninitialized variable analysis", 1021 1000, 1, 0) 1022 1023 /* 1024 Local variables: 1025 mode:c 1026 End: 1027 */ 1028
