gcc/params.def

   1 /* params.def - Run-time parameters.
   2    Copyright (C) 2001-2019 Free Software Foundation, Inc.
   3    Written by Mark Mitchell <mark@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    The DEFPARAMENUM<N> macro is similar, but instead of the minumum and maximum
  39    arguments, it contains a list of <N> allowed strings, corresponding to
  40    integer values 0..<N>-1.  Note that the default argument needs to be
  41    specified as one of the allowed strings, rather than an integer value.
  42
  43    Be sure to add an entry to invoke.texi summarizing the parameter.  */
  44
  45 /* When branch is predicted to be taken with probability lower than this
  46    threshold (in percent), then it is considered well predictable. */
  47 DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME,
  48           "predictable-branch-outcome",
  49           "Maximal estimated outcome of branch considered predictable.",
  50           2, 0, 50)
  51
  52 DEFPARAM (PARAM_INLINE_MIN_SPEEDUP,
  53           "inline-min-speedup",
  54           "The minimal estimated speedup allowing inliner to ignore inline-insns-single and inline-insns-auto.",
  55           15, 0, 0)
  56
  57 /* The single function inlining limit. This is the maximum size
  58    of a function counted in internal gcc instructions (not in
  59    real machine instructions) that is eligible for inlining
  60    by the tree inliner.
  61    The default value is 400.
  62    Only functions marked inline (or methods defined in the class
  63    definition for C++) are affected by this.
  64    There are more restrictions to inlining: If inlined functions
  65    call other functions, the already inlined instructions are
  66    counted and once the recursive inline limit (see
  67    "max-inline-insns" parameter) is exceeded, the acceptable size
  68    gets decreased.  */
  69 DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
  70           "max-inline-insns-single",
  71           "The maximum number of instructions in a single function eligible for inlining.",
  72           400, 0, 0)
  73
  74 /* The single function inlining limit for functions that are
  75    inlined by virtue of -finline-functions (-O3).
  76    This limit should be chosen to be below or equal to the limit
  77    that is applied to functions marked inlined (or defined in the
  78    class declaration in C++) given by the "max-inline-insns-single"
  79    parameter.
  80    The default value is 30.  */
  81 DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
  82           "max-inline-insns-auto",
  83           "The maximum number of instructions when automatically inlining.",
  84           30, 0, 0)
  85
  86 DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
  87           "max-inline-insns-recursive",
  88           "The maximum number of instructions inline function can grow to via recursive inlining.",
  89           450, 0, 0)
  90
  91 DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
  92           "max-inline-insns-recursive-auto",
  93           "The maximum number of instructions non-inline function can grow to via recursive inlining.",
  94           450, 0, 0)
  95
  96 DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
  97           "max-inline-recursive-depth",
  98           "The maximum depth of recursive inlining for inline functions.",
  99           8, 0, 0)
 100
 101 DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
 102           "max-inline-recursive-depth-auto",
 103           "The maximum depth of recursive inlining for non-inline functions.",
 104           8, 0, 0)
 105
 106 DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
 107           "min-inline-recursive-probability",
 108           "Inline recursively only when the probability of call being executed exceeds the parameter.",
 109           10, 0, 0)
 110
 111 /* Limit of iterations of early inliner.  This basically bounds number of
 112    nested indirect calls early inliner can resolve.  Deeper chains are still
 113    handled by late inlining.  */
 114 DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS,
 115           "max-early-inliner-iterations",
 116           "The maximum number of nested indirect inlining performed by early inliner.",
 117           1, 0, 0)
 118
 119 /* Limit on probability of entry BB.  */
 120 DEFPARAM (PARAM_COMDAT_SHARING_PROBABILITY,
 121           "comdat-sharing-probability",
 122           "Probability that COMDAT function will be shared with different compilation unit.",
 123           20, 0, 0)
 124
 125 /* Limit on probability of entry BB.  */
 126 DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY,
 127           "partial-inlining-entry-probability",
 128           "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen.",
 129           70, 0, 100)
 130
 131 /* Limit the number of expansions created by the variable expansion
 132    optimization to avoid register pressure.  */
 133 DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
 134           "max-variable-expansions-in-unroller",
 135           "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling.",
 136           1, 0, 0)
 137
 138 /* Limit loop autovectorization to loops with large enough iteration count.  */
 139 DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND,
 140           "min-vect-loop-bound",
 141           "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization.",
 142           0, 0, 0)
 143
 144 /* The maximum number of instructions to consider when looking for an
 145    instruction to fill a delay slot.  If more than this arbitrary
 146    number of instructions is searched, the time savings from filling
 147    the delay slot will be minimal so stop searching.  Increasing
 148    values mean more aggressive optimization, making the compile time
 149    increase with probably small improvement in executable run time.  */
 150 DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
 151           "max-delay-slot-insn-search",
 152           "The maximum number of instructions to consider to fill a delay slot.",
 153           100, 0, 0)
 154
 155 /* When trying to fill delay slots, the maximum number of instructions
 156    to consider when searching for a block with valid live register
 157    information.  Increasing this arbitrarily chosen value means more
 158    aggressive optimization, increasing the compile time.  This
 159    parameter should be removed when the delay slot code is rewritten
 160    to maintain the control-flow graph.  */
 161 DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
 162          "max-delay-slot-live-search",
 163          "The maximum number of instructions to consider to find accurate live register information.",
 164          333, 0, 0)
 165
 166 /* This parameter limits the number of branch elements that the
 167    scheduler will track anti-dependencies through without resetting
 168    the tracking mechanism.  Large functions with few calls or barriers
 169    can generate lists containing many 1000's of dependencies.  Generally
 170    the compiler either uses all available memory, or runs for far too long.  */
 171 DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
 172          "max-pending-list-length",
 173          "The maximum length of scheduling's pending operations list.",
 174          32, 0, 0)
 175
 176 /* This parameter limits the number of backtracking attempts when using the
 177    haifa scheduler for modulo scheduling.  */
 178 DEFPARAM(PARAM_MAX_MODULO_BACKTRACK_ATTEMPTS,
 179          "max-modulo-backtrack-attempts",
 180          "The maximum number of backtrack attempts the scheduler should make when modulo scheduling a loop.",
 181          40, 0, 0)
 182
 183 DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
 184          "large-function-insns",
 185          "The size of function body to be considered large.",
 186          2700, 0, 0)
 187 DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
 188          "large-function-growth",
 189          "Maximal growth due to inlining of large function (in percent).",
 190          100, 0, 0)
 191 DEFPARAM(PARAM_LARGE_UNIT_INSNS,
 192          "large-unit-insns",
 193          "The size of translation unit to be considered large.",
 194          10000, 0, 0)
 195 DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
 196          "inline-unit-growth",
 197          "How much can given compilation unit grow because of the inlining (in percent).",
 198          20, 0, 0)
 199 DEFPARAM(PARAM_IPCP_UNIT_GROWTH,
 200          "ipcp-unit-growth",
 201          "How much can given compilation unit grow because of the interprocedural constant propagation (in percent).",
 202          10, 0, 0)
 203 DEFPARAM(PARAM_EARLY_INLINING_INSNS,
 204          "early-inlining-insns",
 205          "Maximal estimated growth of function body caused by early inlining of single call.",
 206          14, 0, 0)
 207 DEFPARAM(PARAM_LARGE_STACK_FRAME,
 208          "large-stack-frame",
 209          "The size of stack frame to be considered large.",
 210          256, 0, 0)
 211 DEFPARAM(PARAM_STACK_FRAME_GROWTH,
 212          "large-stack-frame-growth",
 213          "Maximal stack frame growth due to inlining (in percent).",
 214          1000, 0, 0)
 215
 216 /* Keep these up to date with those in configure.ac.  */
 217 DEFPARAM(PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE,
 218          "stack-clash-protection-guard-size",
 219          "Size of the stack guard expressed as a power of two in bytes.",
 220          12, 12, 30)
 221
 222 DEFPARAM(PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL,
 223          "stack-clash-protection-probe-interval",
 224          "Interval in which to probe the stack expressed as a power of two in bytes.",
 225          12, 10, 16)
 226
 227 /* The GCSE optimization will be disabled if it would require
 228    significantly more memory than this value.  */
 229 DEFPARAM(PARAM_MAX_GCSE_MEMORY,
 230          "max-gcse-memory",
 231          "The maximum amount of memory to be allocated by GCSE.",
 232          128 * 1024 * 1024, 0, 0)
 233
 234 /* The GCSE optimization of an expression will avoided if the ratio of
 235    insertions to deletions is greater than this value.  */
 236 DEFPARAM(PARAM_MAX_GCSE_INSERTION_RATIO,
 237          "max-gcse-insertion-ratio",
 238          "The maximum ratio of insertions to deletions of expressions in GCSE.",
 239          20, 0, 0)
 240
 241 /* This is the threshold ratio when to perform partial redundancy
 242    elimination after reload. We perform partial redundancy elimination
 243    when the following holds:
 244    (Redundant load execution count)
 245    ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
 246    (Added loads execution count)                                          */
 247 DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
 248         "gcse-after-reload-partial-fraction",
 249         "The threshold ratio for performing partial redundancy elimination after reload.",
 250         3, 0, 0)
 251 /* This is the threshold ratio of the critical edges execution count compared to
 252    the redundant loads execution count that permits performing the load
 253    redundancy elimination in gcse after reload.  */
 254 DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
 255         "gcse-after-reload-critical-fraction",
 256         "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload.",
 257         10, 0, 0)
 258
 259 /* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor
 260    to calculate maximum distance for which an expression is allowed to move
 261    from its rtx_cost.  */
 262 DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO,
 263          "gcse-cost-distance-ratio",
 264          "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations.",
 265          10, 0, 0)
 266 /* GCSE won't restrict distance for which an expression with rtx_cost greater
 267    than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move.  */
 268 DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST,
 269          "gcse-unrestricted-cost",
 270          "Cost at which GCSE optimizations will not constraint the distance an expression can travel.",
 271          3, 0, 0)
 272
 273 /* How deep from a given basic block the dominator tree should be searched
 274    for expressions to hoist to the block.  The value of 0 will avoid limiting
 275    the search.  */
 276 DEFPARAM(PARAM_MAX_HOIST_DEPTH,
 277          "max-hoist-depth",
 278          "Maximum depth of search in the dominator tree for expressions to hoist.",
 279          30, 0, 0)
 280
 281
 282 /* When synthesizing expnonentiation by a real constant operations using square
 283    roots, this controls how deep sqrt chains we are willing to generate.  */
 284 DEFPARAM(PARAM_MAX_POW_SQRT_DEPTH,
 285          "max-pow-sqrt-depth",
 286          "Maximum depth of sqrt chains to use when synthesizing exponentiation by a real constant.",
 287          5, 1, 32)
 288
 289 /* This parameter limits the number of insns in a loop that will be unrolled,
 290    and by how much the loop is unrolled.
 291
 292    This limit should be at most half of the peeling limits:  loop unroller
 293    decides to not unroll loops that iterate fewer than 2*number of allowed
 294    unrollings and thus we would have loops that are neither peeled or unrolled
 295    otherwise.  */
 296 DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
 297          "max-unrolled-insns",
 298          "The maximum number of instructions to consider to unroll in a loop.",
 299          200, 0, 0)
 300 /* This parameter limits how many times the loop is unrolled depending
 301    on number of insns really executed in each iteration.  */
 302 DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
 303          "max-average-unrolled-insns",
 304          "The maximum number of instructions to consider to unroll in a loop on average.",
 305          80, 0, 0)
 306 /* The maximum number of unrollings of a single loop.  */
 307 DEFPARAM(PARAM_MAX_UNROLL_TIMES,
 308         "max-unroll-times",
 309         "The maximum number of unrollings of a single loop.",
 310         8, 0, 0)
 311 /* The maximum number of insns of a peeled loop.  */
 312 DEFPARAM(PARAM_MAX_PEELED_INSNS,
 313         "max-peeled-insns",
 314         "The maximum number of insns of a peeled loop.",
 315         100, 0, 0)
 316 /* The maximum number of peelings of a single loop.  */
 317 DEFPARAM(PARAM_MAX_PEEL_TIMES,
 318         "max-peel-times",
 319         "The maximum number of peelings of a single loop.",
 320         16, 0, 0)
 321 /* The maximum number of peelings of a single loop that is peeled completely.  */
 322 DEFPARAM(PARAM_MAX_PEEL_BRANCHES,
 323         "max-peel-branches",
 324         "The maximum number of branches on the path through the peeled sequence.",
 325         32, 0, 0)
 326 /* The maximum number of insns of a peeled loop.  */
 327 DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
 328         "max-completely-peeled-insns",
 329         "The maximum number of insns of a completely peeled loop.",
 330         200, 0, 0)
 331 /* The maximum number of peelings of a single loop that is peeled completely.  */
 332 DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
 333         "max-completely-peel-times",
 334         "The maximum number of peelings of a single loop that is peeled completely.",
 335         16, 0, 0)
 336 /* The maximum number of insns of a peeled loop that rolls only once.  */
 337 DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
 338         "max-once-peeled-insns",
 339         "The maximum number of insns of a peeled loop that rolls only once.",
 340         400, 0, 0)
 341 /* The maximum depth of a loop nest we completely peel.  */
 342 DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS,
 343          "max-completely-peel-loop-nest-depth",
 344          "The maximum depth of a loop nest we completely peel.",
 345          8, 0, 0)
 346
 347 /* The maximum number of insns of an unswitched loop.  */
 348 DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
 349         "max-unswitch-insns",
 350         "The maximum number of insns of an unswitched loop.",
 351         50, 0, 0)
 352 /* The maximum level of recursion in unswitch_single_loop.  */
 353 DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
 354         "max-unswitch-level",
 355         "The maximum number of unswitchings in a single loop.",
 356         3, 0, 0)
 357
 358 /* The maximum number of insns in loop header duplicated by the copy loop
 359    headers pass.  */
 360 DEFPARAM(PARAM_MAX_LOOP_HEADER_INSNS,
 361         "max-loop-header-insns",
 362         "The maximum number of insns in loop header duplicated by the copy loop headers pass.",
 363         20, 0, 0)
 364
 365 /* The maximum number of iterations of a loop the brute force algorithm
 366    for analysis of # of iterations of the loop tries to evaluate.  */
 367 DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
 368         "max-iterations-to-track",
 369         "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates.",
 370         1000, 0, 0)
 371 /* A cutoff to avoid costly computations of the number of iterations in
 372    the doloop transformation.  */
 373 DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST,
 374         "max-iterations-computation-cost",
 375         "Bound on the cost of an expression to compute the number of iterations.",
 376         10, 0, 0)
 377
 378 /* This parameter is used to tune SMS MAX II calculations.  */
 379 DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
 380          "sms-max-ii-factor",
 381          "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop.",
 382          100, 0, 0)
 383 /* The minimum value of stage count that swing modulo scheduler will generate.  */
 384 DEFPARAM(PARAM_SMS_MIN_SC,
 385         "sms-min-sc",
 386         "The minimum value of stage count that swing modulo scheduler will generate.",
 387         2, 1, 1)
 388 DEFPARAM(PARAM_SMS_DFA_HISTORY,
 389          "sms-dfa-history",
 390          "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA.",
 391          0, 0, 0)
 392 DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
 393          "sms-loop-average-count-threshold",
 394          "A threshold on the average loop count considered by the swing modulo scheduler.",
 395          0, 0, 0)
 396
 397 DEFPARAM(HOT_BB_COUNT_FRACTION,
 398          "hot-bb-count-fraction",
 399          "Select fraction of the maximal count of repetitions of basic block in program given basic "
 400          "block needs to have to be considered hot (used in non-LTO mode).",
 401          10000, 0, 0)
 402 DEFPARAM(HOT_BB_COUNT_WS_PERMILLE,
 403          "hot-bb-count-ws-permille",
 404          "A basic block profile count is considered hot if it contributes to "
 405          "the given permillage of the entire profiled execution (used in LTO mode).",
 406          990, 0, 1000)
 407 DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
 408          "hot-bb-frequency-fraction",
 409          "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot.",
 410          1000, 0, 0)
 411
 412 DEFPARAM(UNLIKELY_BB_COUNT_FRACTION,
 413          "unlikely-bb-count-fraction",
 414          "The minimum fraction of profile runs a given basic block execution count must be not to be considered unlikely.",
 415          20, 1, 10000)
 416
 417 DEFPARAM (PARAM_ALIGN_THRESHOLD,
 418           "align-threshold",
 419           "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment.",
 420           100, 1, 0)
 421
 422 DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS,
 423           "align-loop-iterations",
 424           "Loops iterating at least selected number of iterations will get "
 425           "loop alignment.", 4, 0, 0)
 426
 427 /* For guessed profiles, the loops having unknown number of iterations
 428    are predicted to iterate relatively few (10) times at average.
 429    For functions containing one loop with large known number of iterations
 430    and other loops having unbounded loops we would end up predicting all
 431    the other loops cold that is not usually the case.  So we need to artificially
 432    flatten the profile.
 433
 434    We need to cut the maximal predicted iterations to large enough iterations
 435    so the loop appears important, but safely within maximum hotness
 436    range.  */
 437
 438 DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
 439          "max-predicted-iterations",
 440          "The maximum number of loop iterations we predict statically.",
 441          100, 0, 0)
 442
 443 /* This parameter controls the probability of builtin_expect. The default
 444    value is 90%. This empirical value is obtained through the weighted
 445    probability of FDO counters (with the FDO count value as the weight)
 446    in some real world programs:
 447    (1) Google performance test benchmarks: the probability is 0.9081.
 448    (2) Linux 3.3 kernel running Google search workload: the probability
 449    is 0.8717.  */
 450
 451 DEFPARAM(BUILTIN_EXPECT_PROBABILITY,
 452          "builtin-expect-probability",
 453          "Set the estimated probability in percentage for builtin expect. The default value is 90% probability.",
 454          90, 0, 100)
 455 DEFPARAM(BUILTIN_STRING_CMP_INLINE_LENGTH,
 456          "builtin-string-cmp-inline-length",
 457          "The maximum length of a constant string for a builtin string cmp call eligible for inlining. The default value is 3.",
 458          3, 0, 100)
 459 DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
 460          "tracer-dynamic-coverage-feedback",
 461          "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available.",
 462          95, 0, 100)
 463 DEFPARAM(TRACER_DYNAMIC_COVERAGE,
 464          "tracer-dynamic-coverage",
 465          "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available.",
 466          75, 0, 100)
 467 DEFPARAM(TRACER_MAX_CODE_GROWTH,
 468          "tracer-max-code-growth",
 469          "Maximal code growth caused by tail duplication (in percent).",
 470          100, 0, 0)
 471 DEFPARAM(TRACER_MIN_BRANCH_RATIO,
 472          "tracer-min-branch-ratio",
 473          "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent).",
 474          10, 0, 100)
 475 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
 476          "tracer-min-branch-probability-feedback",
 477          "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available.",
 478          80, 0, 100)
 479 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
 480          "tracer-min-branch-probability",
 481          "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available.",
 482          50, 0, 100)
 483
 484 /* The maximum number of incoming edges to consider for crossjumping.  */
 485 DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
 486          "max-crossjump-edges",
 487          "The maximum number of incoming edges to consider for crossjumping.",
 488          100, 0, 0)
 489
 490 /* The minimum number of matching instructions to consider for crossjumping.  */
 491 DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
 492      "min-crossjump-insns",
 493      "The minimum number of matching instructions to consider for crossjumping.",
 494      5, 1, 0)
 495
 496 /* The maximum number expansion factor when copying basic blocks.  */
 497 DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
 498      "max-grow-copy-bb-insns",
 499      "The maximum expansion factor when copying basic blocks.",
 500      8, 0, 0)
 501
 502 /* The maximum number of insns to duplicate when unfactoring computed gotos.  */
 503 DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
 504      "max-goto-duplication-insns",
 505      "The maximum number of insns to duplicate when unfactoring computed gotos.",
 506      8, 0, 0)
 507
 508 /* The maximum length of path considered in cse.  */
 509 DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
 510          "max-cse-path-length",
 511          "The maximum length of path considered in cse.",
 512          10, 1, 0)
 513 DEFPARAM(PARAM_MAX_CSE_INSNS,
 514          "max-cse-insns",
 515          "The maximum instructions CSE process before flushing.",
 516          1000, 0, 0)
 517
 518 /* The cost of expression in loop invariant motion that is considered
 519    expensive.  */
 520 DEFPARAM(PARAM_LIM_EXPENSIVE,
 521          "lim-expensive",
 522          "The minimum cost of an expensive expression in the loop invariant motion.",
 523          20, 0, 0)
 524
 525 /* Bound on number of candidates for induction variables below that
 526    all candidates are considered for each use in induction variable
 527    optimizations.  */
 528
 529 DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
 530          "iv-consider-all-candidates-bound",
 531          "Bound on number of candidates below that all candidates are considered in iv optimizations.",
 532          40, 0, 0)
 533
 534 /* The induction variable optimizations give up on loops that contain more
 535    induction variable uses.  */
 536
 537 DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
 538          "iv-max-considered-uses",
 539          "Bound on number of iv uses in loop optimized in iv optimizations.",
 540          250, 0, 0)
 541
 542 /* If there are at most this number of ivs in the set, try removing unnecessary
 543    ivs from the set always.  */
 544
 545 DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
 546          "iv-always-prune-cand-set-bound",
 547          "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization.",
 548          10, 0, 0)
 549
 550 DEFPARAM(PARAM_AVG_LOOP_NITER,
 551          "avg-loop-niter",
 552          "Average number of iterations of a loop.",
 553          10, 1, 0)
 554
 555 DEFPARAM(PARAM_DSE_MAX_OBJECT_SIZE,
 556          "dse-max-object-size",
 557          "Maximum size (in bytes) of objects tracked bytewise by dead store elimination.",
 558          256, 0, 0)
 559
 560 DEFPARAM(PARAM_DSE_MAX_ALIAS_QUERIES_PER_STORE,
 561          "dse-max-alias-queries-per-store",
 562          "Maximum number of queries into the alias oracle per store.",
 563          256, 0, 0)
 564
 565 DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
 566          "scev-max-expr-size",
 567          "Bound on size of expressions used in the scalar evolutions analyzer.",
 568          100, 0, 0)
 569
 570 DEFPARAM(PARAM_SCEV_MAX_EXPR_COMPLEXITY,
 571          "scev-max-expr-complexity",
 572          "Bound on the complexity of the expressions in the scalar evolutions analyzer.",
 573          10, 0, 0)
 574
 575 DEFPARAM (PARAM_MAX_TREE_IF_CONVERSION_PHI_ARGS,
 576           "max-tree-if-conversion-phi-args",
 577           "Maximum number of arguments in a PHI supported by TREE if-conversion "
 578           "unless the loop is marked with simd pragma.",
 579           4, 2, 0)
 580
 581 DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS,
 582          "vect-max-version-for-alignment-checks",
 583          "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check.",
 584          6, 0, 0)
 585
 586 DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS,
 587          "vect-max-version-for-alias-checks",
 588          "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alias check.",
 589          10, 0, 0)
 590
 591 DEFPARAM(PARAM_VECT_MAX_PEELING_FOR_ALIGNMENT,
 592          "vect-max-peeling-for-alignment",
 593          "Maximum number of loop peels to enhance alignment of data references in a loop.",
 594          -1, -1, 64)
 595
 596 DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
 597          "max-cselib-memory-locations",
 598          "The maximum memory locations recorded by cselib.",
 599          500, 0, 0)
 600
 601 #ifdef ENABLE_GC_ALWAYS_COLLECT
 602 # define GGC_MIN_EXPAND_DEFAULT 0
 603 # define GGC_MIN_HEAPSIZE_DEFAULT 0
 604 #else
 605 # define GGC_MIN_EXPAND_DEFAULT 30
 606 # define GGC_MIN_HEAPSIZE_DEFAULT 4096
 607 #endif
 608
 609 DEFPARAM(GGC_MIN_EXPAND,
 610          "ggc-min-expand",
 611          "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap.",
 612          GGC_MIN_EXPAND_DEFAULT, 0, 0)
 613
 614 DEFPARAM(GGC_MIN_HEAPSIZE,
 615          "ggc-min-heapsize",
 616          "Minimum heap size before we start collecting garbage, in kilobytes.",
 617          GGC_MIN_HEAPSIZE_DEFAULT, 0, 0)
 618
 619 #undef GGC_MIN_EXPAND_DEFAULT
 620 #undef GGC_MIN_HEAPSIZE_DEFAULT
 621
 622 DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
 623          "max-reload-search-insns",
 624          "The maximum number of instructions to search backward when looking for equivalent reload.",
 625          100, 0, 0)
 626
 627 DEFPARAM(PARAM_SINK_FREQUENCY_THRESHOLD,
 628          "sink-frequency-threshold",
 629          "Target block's relative execution frequency (as a percentage) required to sink a statement.",
 630          75, 0, 100)
 631
 632 DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS,
 633          "max-sched-region-blocks",
 634          "The maximum number of blocks in a region to be considered for interblock scheduling.",
 635          10, 0, 0)
 636
 637 DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS,
 638          "max-sched-region-insns",
 639          "The maximum number of insns in a region to be considered for interblock scheduling.",
 640          100, 0, 0)
 641
 642 DEFPARAM(PARAM_MAX_PIPELINE_REGION_BLOCKS,
 643          "max-pipeline-region-blocks",
 644          "The maximum number of blocks in a region to be considered for interblock scheduling.",
 645          15, 0, 0)
 646
 647 DEFPARAM(PARAM_MAX_PIPELINE_REGION_INSNS,
 648          "max-pipeline-region-insns",
 649          "The maximum number of insns in a region to be considered for interblock scheduling.",
 650          200, 0, 0)
 651
 652 DEFPARAM(PARAM_MIN_SPEC_PROB,
 653          "min-spec-prob",
 654          "The minimum probability of reaching a source block for interblock speculative scheduling.",
 655          40, 0, 0)
 656
 657 DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS,
 658          "max-sched-extend-regions-iters",
 659          "The maximum number of iterations through CFG to extend regions.",
 660          0, 0, 0)
 661
 662 DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY,
 663          "max-sched-insn-conflict-delay",
 664          "The maximum conflict delay for an insn to be considered for speculative motion.",
 665          3, 1, 10)
 666
 667 DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF,
 668          "sched-spec-prob-cutoff",
 669          "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.",
 670          40, 0, 100)
 671
 672 DEFPARAM(PARAM_SCHED_STATE_EDGE_PROB_CUTOFF,
 673          "sched-state-edge-prob-cutoff",
 674          "The minimum probability an edge must have for the scheduler to save its state across it.",
 675          10, 0, 100)
 676
 677 DEFPARAM(PARAM_SELSCHED_MAX_LOOKAHEAD,
 678          "selsched-max-lookahead",
 679          "The maximum size of the lookahead window of selective scheduling.",
 680          50, 0, 0)
 681
 682 DEFPARAM(PARAM_SELSCHED_MAX_SCHED_TIMES,
 683          "selsched-max-sched-times",
 684          "Maximum number of times that an insn could be scheduled.",
 685          2, 1, 0)
 686
 687 DEFPARAM(PARAM_SELSCHED_INSNS_TO_RENAME,
 688          "selsched-insns-to-rename",
 689          "Maximum number of instructions in the ready list that are considered eligible for renaming.",
 690          2, 0, 0)
 691
 692 DEFPARAM (PARAM_SCHED_MEM_TRUE_DEP_COST,
 693           "sched-mem-true-dep-cost",
 694           "Minimal distance between possibly conflicting store and load.",
 695           1, 0, 0)
 696
 697 DEFPARAM (PARAM_SCHED_AUTOPREF_QUEUE_DEPTH,
 698           "sched-autopref-queue-depth",
 699           "Hardware autoprefetcher scheduler model control flag.  Number of lookahead cycles the model looks into; at '0' only enable instruction sorting heuristic.  Disabled by default.",
 700           -1, 0, 0)
 701
 702 DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
 703          "max-last-value-rtl",
 704          "The maximum number of RTL nodes that can be recorded as combiner's last value.",
 705          10000, 0, 0)
 706
 707 DEFPARAM(PARAM_MAX_COMBINE_INSNS,
 708          "max-combine-insns",
 709          "The maximum number of insns combine tries to combine.",
 710          4, 2, 4)
 711
 712 /* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
 713    {signed,unsigned} integral types.  This determines N.
 714    Experimentation shows 251 to be a good value that generates the
 715    least amount of garbage for allocating the TREE_VEC storage.  */
 716 DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
 717           "integer-share-limit",
 718           "The upper bound for sharing integer constants.",
 719           251, 2, 2)
 720
 721 DEFPARAM (PARAM_SSP_BUFFER_SIZE,
 722           "ssp-buffer-size",
 723           "The lower bound for a buffer to be considered for stack smashing protection.",
 724           8, 1, 0)
 725
 726 DEFPARAM (PARAM_MIN_SIZE_FOR_STACK_SHARING,
 727           "min-size-for-stack-sharing",
 728           "The minimum size of variables taking part in stack slot sharing "
 729           "when not optimizing.",
 730           32, 0, 0)
 731
 732 /* When we thread through a block we have to make copies of the
 733    statements within the block.  Clearly for large blocks the code
 734    duplication is bad.
 735
 736    PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number
 737    of statements and PHI nodes allowed in a block which is going to
 738    be duplicated for thread jumping purposes.
 739
 740    Some simple analysis showed that more than 99% of the jump
 741    threading opportunities are for blocks with less than 15
 742    statements.  So we can get the benefits of jump threading
 743    without excessive code bloat for pathological cases with the
 744    throttle set at 15 statements.  */
 745 DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS,
 746           "max-jump-thread-duplication-stmts",
 747           "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps.",
 748           15, 0, 0)
 749
 750 /* This is the maximum number of fields a variable may have before the pointer analysis machinery
 751    will stop trying to treat it in a field-sensitive manner.
 752    There are programs out there with thousands of fields per structure, and handling them
 753    field-sensitively is not worth the cost.  */
 754 DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE,
 755           "max-fields-for-field-sensitive",
 756           "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable.",
 757           0, 0, 0)
 758
 759 DEFPARAM(PARAM_MAX_SCHED_READY_INSNS,
 760          "max-sched-ready-insns",
 761          "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass.",
 762          100, 1, 0)
 763
 764 /* This is the maximum number of active local stores RTL DSE will consider.  */
 765 DEFPARAM (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES,
 766           "max-dse-active-local-stores",
 767           "Maximum number of active local stores in RTL dead store elimination.",
 768           5000, 0, 0)
 769
 770 /* Prefetching and cache-optimizations related parameters.  Default values are
 771    usually set by machine description.  */
 772
 773 /* The number of insns executed before prefetch is completed.  */
 774
 775 DEFPARAM (PARAM_PREFETCH_LATENCY,
 776          "prefetch-latency",
 777          "The number of insns executed before prefetch is completed.",
 778          200, 0, 0)
 779
 780 /* The number of prefetches that can run at the same time.  */
 781
 782 DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES,
 783           "simultaneous-prefetches",
 784           "The number of prefetches that can run at the same time.",
 785           3, 0, 0)
 786
 787 /* The size of L1 cache in kB.  */
 788
 789 DEFPARAM (PARAM_L1_CACHE_SIZE,
 790           "l1-cache-size",
 791           "The size of L1 cache.",
 792           64, 0, 0)
 793
 794 /* The size of L1 cache line in bytes.  */
 795
 796 DEFPARAM (PARAM_L1_CACHE_LINE_SIZE,
 797           "l1-cache-line-size",
 798           "The size of L1 cache line.",
 799           32, 0, 0)
 800
 801 /* The size of L2 cache in kB.  */
 802
 803 DEFPARAM (PARAM_L2_CACHE_SIZE,
 804           "l2-cache-size",
 805           "The size of L2 cache.",
 806           512, 0, 0)
 807
 808 /* Whether software prefetch hints should be issued for non-constant
 809    strides.  */
 810
 811 DEFPARAM (PARAM_PREFETCH_DYNAMIC_STRIDES,
 812           "prefetch-dynamic-strides",
 813           "Whether software prefetch hints should be issued for non-constant "
 814           "strides.",
 815           1, 0, 1)
 816
 817 /* The minimum constant stride beyond which we should use prefetch hints
 818    for.  */
 819
 820 DEFPARAM (PARAM_PREFETCH_MINIMUM_STRIDE,
 821           "prefetch-minimum-stride",
 822           "The minimum constant stride beyond which we should use prefetch "
 823           "hints for.",
 824           -1, 0, 0)
 825
 826 /* Maximum number of statements in loop nest for loop interchange.  */
 827
 828 DEFPARAM (PARAM_LOOP_INTERCHANGE_MAX_NUM_STMTS,
 829           "loop-interchange-max-num-stmts",
 830           "The maximum number of stmts in loop nest for loop interchange.",
 831           64, 0, 0)
 832
 833 /* Minimum stride ratio for loop interchange to be profitiable.  */
 834
 835 DEFPARAM (PARAM_LOOP_INTERCHANGE_STRIDE_RATIO,
 836           "loop-interchange-stride-ratio",
 837           "The minimum stride ratio for loop interchange to be profitable.",
 838           2, 0, 0)
 839
 840 /* Whether we should use canonical types rather than deep "structural"
 841    type checking.  Setting this value to 1 (the default) improves
 842    compilation performance in the C++ and Objective-C++ front end;
 843    this value should only be set to zero to work around bugs in the
 844    canonical type system by disabling it.  */
 845
 846 DEFPARAM (PARAM_USE_CANONICAL_TYPES,
 847           "use-canonical-types",
 848           "Whether to use canonical types.",
 849           1, 0, 1)
 850
 851 DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH,
 852           "max-partial-antic-length",
 853           "Maximum length of partial antic set when performing tree pre optimization.",
 854           100, 0, 0)
 855
 856 /* The following is used as a stop-gap limit for cases where really deep
 857    loop nests cause compile-time to blow up.  If we hit this limit,
 858    FRE and PRE will value-number outer loops (but the outermost) in a
 859    loop nest non-optimistically.  */
 860
 861 DEFPARAM (PARAM_RPO_VN_MAX_LOOP_DEPTH,
 862           "rpo-vn-max-loop-depth",
 863           "Maximum depth of a loop nest to fully value-number optimistically.",
 864           7, 2, 0)
 865
 866 /* The following is used as a stop-gap limit for cases where really huge
 867    functions blow up compile-time use too much.  It limits the number of
 868    alias-queries we do for finding common subexpressions for memory loads and
 869    stores.  The number of alias-queries is otherwise limited by the number of
 870    stores on paths to function entry.  */
 871
 872 DEFPARAM (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS,
 873           "sccvn-max-alias-queries-per-access",
 874           "Maximum number of disambiguations to perform per memory access.",
 875           1000, 0, 0)
 876
 877 DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM,
 878           "ira-max-loops-num",
 879           "Max loops number for regional RA.",
 880           100, 0, 0)
 881
 882 DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE,
 883           "ira-max-conflict-table-size",
 884           "Max size of conflict table in MB.",
 885           1000, 0, 0)
 886
 887 DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS,
 888           "ira-loop-reserved-regs",
 889           "The number of registers in each class kept unused by loop invariant motion.",
 890           2, 0, 0)
 891
 892 DEFPARAM (PARAM_LRA_MAX_CONSIDERED_RELOAD_PSEUDOS,
 893           "lra-max-considered-reload-pseudos",
 894           "The max number of reload pseudos which are considered during spilling a non-reload pseudo.",
 895           500, 0, 0)
 896
 897 DEFPARAM (PARAM_LRA_INHERITANCE_EBB_PROBABILITY_CUTOFF,
 898           "lra-inheritance-ebb-probability-cutoff",
 899           "Minimal fall-through edge probability in percentage used to add BB to inheritance EBB in LRA.",
 900           40, 0, 100)
 901
 902 /* Switch initialization conversion will refuse to create arrays that are
 903    bigger than this parameter times the number of switch branches.  */
 904
 905 DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO,
 906           "switch-conversion-max-branch-ratio",
 907           "The maximum ratio between array size and switch branches for "
 908           "a switch conversion to take place.",
 909           8, 1, 0)
 910
 911 /* Size of tiles when doing loop blocking.  */
 912
 913 DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE,
 914           "loop-block-tile-size",
 915           "Size of tiles for loop blocking.",
 916           51, 0, 0)
 917
 918 /* Maximal number of parameters that we allow in a SCoP.  */
 919
 920 DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS,
 921           "graphite-max-nb-scop-params",
 922           "Maximum number of parameters in a SCoP.",
 923           10, 0, 0)
 924
 925 /* Maximal number of array references in a scop.  */
 926
 927 DEFPARAM (PARAM_GRAPHITE_MAX_ARRAYS_PER_SCOP,
 928           "graphite-max-arrays-per-scop",
 929           "Maximum number of arrays per scop.",
 930           100, 0, 0)
 931
 932 DEFPARAM (PARAM_MAX_ISL_OPERATIONS,
 933           "max-isl-operations",
 934           "Maximum number of isl operations, 0 means unlimited.",
 935           350000, 0, 0)
 936
 937 /* For testsuite purposes allow to check for codegen error handling.  */
 938 DEFPARAM (PARAM_GRAPHITE_ALLOW_CODEGEN_ERRORS,
 939           "graphite-allow-codegen-errors",
 940           "Whether codegen errors should be ICEs when -fchecking.",
 941           0, 0, 1)
 942
 943 /* Avoid data dependence analysis on very large loops.  */
 944 DEFPARAM (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS,
 945           "loop-max-datarefs-for-datadeps",
 946           "Maximum number of datarefs in loop for building loop data dependencies.",
 947           1000, 0, 0)
 948
 949 /* Avoid doing loop invariant motion on very large loops.  */
 950
 951 DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP,
 952           "loop-invariant-max-bbs-in-loop",
 953           "Max basic blocks number in loop for loop invariant motion.",
 954           10000, 0, 0)
 955
 956 /* When the parameter is 1, use the internal function id
 957    to look up for profile data. Otherwise, use a more stable
 958    external id based on assembler name and source location. */
 959 DEFPARAM (PARAM_PROFILE_FUNC_INTERNAL_ID,
 960           "profile-func-internal-id",
 961           "Use internal function id in profile lookup.",
 962           0, 0, 1)
 963
 964 /* When the parameter is 1, track the most frequent N target
 965    addresses in indirect-call profile. This disables
 966    indirect_call_profiler_v2 which tracks single target.  */
 967 DEFPARAM (PARAM_INDIR_CALL_TOPN_PROFILE,
 968           "indir-call-topn-profile",
 969           "Track top N target addresses in indirect-call profile.",
 970           0, 0, 1)
 971
 972 /* Avoid SLP vectorization of large basic blocks.  */
 973 DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB,
 974           "slp-max-insns-in-bb",
 975           "Maximum number of instructions in basic block to be considered for "
 976           "SLP vectorization.", 1000, 0, 0)
 977
 978 DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO,
 979           "min-insn-to-prefetch-ratio",
 980           "Min. ratio of insns to prefetches to enable prefetching for "
 981           "a loop with an unknown trip count.",
 982           9, 0, 0)
 983
 984 DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO,
 985           "prefetch-min-insn-to-mem-ratio",
 986           "Min. ratio of insns to mem ops to enable prefetching in a loop.",
 987           3, 0, 0)
 988
 989 /* Set maximum hash table size for var tracking.  */
 990
 991 DEFPARAM (PARAM_MAX_VARTRACK_SIZE,
 992           "max-vartrack-size",
 993           "Max. size of var tracking hash tables.",
 994           50000000, 0, 0)
 995
 996 /* Set maximum recursion depth for var tracking expression expansion
 997    and resolution.  */
 998
 999 DEFPARAM (PARAM_MAX_VARTRACK_EXPR_DEPTH,
1000           "max-vartrack-expr-depth",
1001           "Max. recursion depth for expanding var tracking expressions.",
1002           12, 0, 0)
1003
1004 /* Set maximum length of value location list for which var tracking
1005    should add reverse operations.  */
1006
1007 DEFPARAM (PARAM_MAX_VARTRACK_REVERSE_OP_SIZE,
1008           "max-vartrack-reverse-op-size",
1009           "Max. size of loc list for which reverse ops should be added.",
1010           50, 0, 0)
1011
1012 /* Set a threshold to discard debug markers (e.g. debug begin stmt
1013    markers) when expanding a function to RTL, or inlining it into
1014    another function.  */
1015
1016 DEFPARAM (PARAM_MAX_DEBUG_MARKER_COUNT,
1017           "max-debug-marker-count",
1018           "Max. count of debug markers to expand or inline.",
1019           100000, 0, 0)
1020
1021 /* Set minimum insn uid for non-debug insns.  */
1022
1023 DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID,
1024           "min-nondebug-insn-uid",
1025           "The minimum UID to be used for a nondebug insn.",
1026           0, 0, 0)
1027
1028 DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR,
1029           "ipa-sra-ptr-growth-factor",
1030           "Maximum allowed growth of number and total size of new parameters "
1031           "that ipa-sra replaces a pointer to an aggregate with.",
1032           2, 0, 0)
1033
1034 DEFPARAM (PARAM_TM_MAX_AGGREGATE_SIZE,
1035           "tm-max-aggregate-size",
1036           "Size in bytes after which thread-local aggregates should be "
1037           "instrumented with the logging functions instead of save/restore "
1038           "pairs.",
1039           9, 0, 0)
1040
1041 DEFPARAM (PARAM_SRA_MAX_SCALARIZATION_SIZE_SPEED,
1042           "sra-max-scalarization-size-Ospeed",
1043           "Maximum size, in storage units, of an aggregate which should be "
1044           "considered for scalarization when compiling for speed.",
1045           0, 0, 0)
1046
1047 DEFPARAM (PARAM_SRA_MAX_SCALARIZATION_SIZE_SIZE,
1048           "sra-max-scalarization-size-Osize",
1049           "Maximum size, in storage units, of an aggregate which should be "
1050           "considered for scalarization when compiling for size.",
1051           0, 0, 0)
1052
1053 DEFPARAM (PARAM_IPA_CP_VALUE_LIST_SIZE,
1054           "ipa-cp-value-list-size",
1055           "Maximum size of a list of values associated with each parameter for "
1056           "interprocedural constant propagation.",
1057           8, 0, 0)
1058
1059 DEFPARAM (PARAM_IPA_CP_EVAL_THRESHOLD,
1060           "ipa-cp-eval-threshold",
1061           "Threshold ipa-cp opportunity evaluation that is still considered "
1062           "beneficial to clone.",
1063           500, 0, 0)
1064
1065 DEFPARAM (PARAM_IPA_CP_RECURSION_PENALTY,
1066           "ipa-cp-recursion-penalty",
1067           "Percentage penalty the recursive functions will receive when they "
1068           "are evaluated for cloning.",
1069           40, 0, 100)
1070
1071 DEFPARAM (PARAM_IPA_CP_SINGLE_CALL_PENALTY,
1072           "ipa-cp-single-call-penalty",
1073           "Percentage penalty functions containing a single call to another "
1074           "function will receive when they are evaluated for cloning.",
1075           15, 0, 100)
1076
1077 DEFPARAM (PARAM_IPA_MAX_AGG_ITEMS,
1078           "ipa-max-agg-items",
1079           "Maximum number of aggregate content items for a parameter in "
1080           "jump functions and lattices.",
1081           16, 0, 0)
1082
1083 DEFPARAM (PARAM_IPA_CP_LOOP_HINT_BONUS,
1084           "ipa-cp-loop-hint-bonus",
1085           "Compile-time bonus IPA-CP assigns to candidates which make loop "
1086           "bounds or strides known.",
1087           64, 0, 0)
1088
1089 DEFPARAM (PARAM_IPA_CP_ARRAY_INDEX_HINT_BONUS,
1090           "ipa-cp-array-index-hint-bonus",
1091           "Compile-time bonus IPA-CP assigns to candidates which make an array "
1092           "index known.",
1093           48, 0, 0)
1094
1095 DEFPARAM (PARAM_IPA_MAX_AA_STEPS,
1096           "ipa-max-aa-steps",
1097           "Maximum number of statements that will be visited by IPA formal "
1098           "parameter analysis based on alias analysis in any given function.",
1099           25000, 0, 0)
1100
1101 /* WHOPR partitioning configuration.  */
1102
1103 DEFPARAM (PARAM_LTO_PARTITIONS,
1104           "lto-partitions",
1105           "Number of partitions the program should be split to.",
1106           128, 1, 0)
1107
1108 DEFPARAM (MIN_PARTITION_SIZE,
1109           "lto-min-partition",
1110           "Minimal size of a partition for LTO (in estimated instructions).",
1111           10000, 0, 0)
1112
1113 DEFPARAM (MAX_PARTITION_SIZE,
1114           "lto-max-partition",
1115           "Maximal size of a partition for LTO (in estimated instructions).",
1116           1000000, 0, INT_MAX)
1117
1118 /* Diagnostic parameters.  */
1119
1120 DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP,
1121           "cxx-max-namespaces-for-diagnostic-help",
1122           "Maximum number of namespaces to search for alternatives when "
1123           "name lookup fails.",
1124           1000, 0, 0)
1125
1126 /* Maximum number of conditional store pairs that can be sunk.  */
1127 DEFPARAM (PARAM_MAX_STORES_TO_SINK,
1128           "max-stores-to-sink",
1129           "Maximum number of conditional store pairs that can be sunk.",
1130           2, 0, 0)
1131
1132 /* Override CASE_VALUES_THRESHOLD of when to switch from doing switch
1133    statements via if statements to using a table jump operation.  If the value
1134    is 0, the default CASE_VALUES_THRESHOLD will be used.  */
1135 DEFPARAM (PARAM_CASE_VALUES_THRESHOLD,
1136           "case-values-threshold",
1137           "The smallest number of different values for which it is best to "
1138           "use a jump-table instead of a tree of conditional branches, "
1139           "if 0, use the default for the machine.",
1140           0, 0, 0)
1141
1142 /* Data race flags for C++0x memory model compliance.  */
1143 DEFPARAM (PARAM_ALLOW_STORE_DATA_RACES,
1144           "allow-store-data-races",
1145           "Allow new data races on stores to be introduced.",
1146           0, 0, 1)
1147
1148 /* Reassociation width to be used by tree reassoc optimization.  */
1149 DEFPARAM (PARAM_TREE_REASSOC_WIDTH,
1150           "tree-reassoc-width",
1151           "Set the maximum number of instructions executed in parallel in "
1152           "reassociated tree.  If 0, use the target dependent heuristic.",
1153           0, 0, 0)
1154
1155 DEFPARAM (PARAM_MAX_TAIL_MERGE_COMPARISONS,
1156           "max-tail-merge-comparisons",
1157           "Maximum amount of similar bbs to compare a bb with.",
1158           10, 0, 0)
1159
1160 DEFPARAM (PARAM_STORE_MERGING_ALLOW_UNALIGNED,
1161           "store-merging-allow-unaligned",
1162           "Allow the store merging pass to introduce unaligned stores "
1163           "if it is legal to do so.",
1164           1, 0, 1)
1165
1166 DEFPARAM (PARAM_MAX_STORES_TO_MERGE,
1167           "max-stores-to-merge",
1168           "Maximum number of constant stores to merge in the "
1169           "store merging pass.",
1170           64, 2, 0)
1171
1172 DEFPARAM (PARAM_MAX_TAIL_MERGE_ITERATIONS,
1173           "max-tail-merge-iterations",
1174           "Maximum amount of iterations of the pass over a function.",
1175           2, 0, 0)
1176
1177 /* Maximum number of strings for which strlen optimization pass will
1178    track string lenths.  */
1179 DEFPARAM (PARAM_MAX_TRACKED_STRLENS,
1180           "max-tracked-strlens",
1181           "Maximum number of strings for which strlen optimization pass will "
1182           "track string lengths.",
1183           10000, 0, 0)
1184
1185 /* Keep this in sync with the sched_pressure_algorithm enum.  */
1186 DEFPARAM (PARAM_SCHED_PRESSURE_ALGORITHM,
1187           "sched-pressure-algorithm",
1188           "Which -fsched-pressure algorithm to apply.",
1189           1, 1, 2)
1190
1191 /* Maximum length of candidate scans in straight-line strength reduction.  */
1192 DEFPARAM (PARAM_MAX_SLSR_CANDIDATE_SCAN,
1193           "max-slsr-cand-scan",
1194           "Maximum length of candidate scans for straight-line "
1195           "strength reduction.",
1196           50, 1, 999999)
1197
1198 /* ASan stands for AddressSanitizer: https://github.com/google/sanitizers.  */
1199
1200 DEFPARAM (PARAM_ASAN_STACK,
1201          "asan-stack",
1202          "Enable asan stack protection.",
1203          1, 0, 1)
1204
1205 DEFPARAM (PARAM_ASAN_PROTECT_ALLOCAS,
1206         "asan-instrument-allocas",
1207         "Enable asan allocas/VLAs protection.",
1208         1, 0, 1)
1209
1210 DEFPARAM (PARAM_ASAN_GLOBALS,
1211          "asan-globals",
1212          "Enable asan globals protection.",
1213          1, 0, 1)
1214
1215 DEFPARAM (PARAM_ASAN_INSTRUMENT_WRITES,
1216          "asan-instrument-writes",
1217          "Enable asan store operations protection.",
1218          1, 0, 1)
1219
1220 DEFPARAM (PARAM_ASAN_INSTRUMENT_READS,
1221          "asan-instrument-reads",
1222          "Enable asan load operations protection.",
1223          1, 0, 1)
1224
1225 DEFPARAM (PARAM_ASAN_MEMINTRIN,
1226          "asan-memintrin",
1227          "Enable asan builtin functions protection.",
1228          1, 0, 1)
1229
1230 DEFPARAM (PARAM_ASAN_USE_AFTER_RETURN,
1231          "asan-use-after-return",
1232          "Enable asan detection of use-after-return bugs.",
1233          1, 0, 1)
1234
1235 DEFPARAM (PARAM_ASAN_INSTRUMENTATION_WITH_CALL_THRESHOLD,
1236          "asan-instrumentation-with-call-threshold",
1237          "Use callbacks instead of inline code if number of accesses "
1238          "in function becomes greater or equal to this number.",
1239          7000, 0, INT_MAX)
1240
1241 DEFPARAM (PARAM_USE_AFTER_SCOPE_DIRECT_EMISSION_THRESHOLD,
1242          "use-after-scope-direct-emission-threshold",
1243          "Use direct poisoning/unpoisoning instructions for variables "
1244          "smaller or equal to this number.",
1245          256, 0, INT_MAX)
1246
1247 DEFPARAM (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS,
1248           "uninit-control-dep-attempts",
1249           "Maximum number of nested calls to search for control dependencies "
1250           "during uninitialized variable analysis.",
1251           1000, 1, 0)
1252
1253 DEFPARAM (PARAM_FSM_SCALE_PATH_STMTS,
1254           "fsm-scale-path-stmts",
1255           "Scale factor to apply to the number of statements in a threading path when comparing to the number of (scaled) blocks.",
1256           2, 1, 10)
1257
1258 DEFPARAM (PARAM_FSM_MAXIMUM_PHI_ARGUMENTS,
1259           "fsm-maximum-phi-arguments",
1260           "Maximum number of arguments a PHI may have before the FSM threader will not try to thread through its block.",
1261           100, 1, 999999)
1262
1263 DEFPARAM (PARAM_FSM_SCALE_PATH_BLOCKS,
1264           "fsm-scale-path-blocks",
1265           "Scale factor to apply to the number of blocks in a threading path when comparing to the number of (scaled) statements.",
1266           3, 1, 10)
1267
1268 DEFPARAM (PARAM_MAX_FSM_THREAD_PATH_INSNS,
1269           "max-fsm-thread-path-insns",
1270           "Maximum number of instructions to copy when duplicating blocks on a finite state automaton jump thread path.",
1271           100, 1, 999999)
1272
1273 DEFPARAM (PARAM_MAX_FSM_THREAD_LENGTH,
1274           "max-fsm-thread-length",
1275           "Maximum number of basic blocks on a finite state automaton jump thread path.",
1276           10, 1, 999999)
1277
1278 DEFPARAM (PARAM_MAX_FSM_THREAD_PATHS,
1279           "max-fsm-thread-paths",
1280           "Maximum number of new jump thread paths to create for a finite state automaton.",
1281           50, 1, 999999)
1282
1283 DEFPARAM (PARAM_PARLOOPS_CHUNK_SIZE,
1284           "parloops-chunk-size",
1285           "Chunk size of omp schedule for loops parallelized by parloops.",
1286           0, 0, 0)
1287
1288 DEFPARAMENUM5 (PARAM_PARLOOPS_SCHEDULE,
1289                "parloops-schedule",
1290                "Schedule type of omp schedule for loops parallelized by "
1291                "parloops (static, dynamic, guided, auto, runtime).",
1292                static,
1293                static, dynamic, guided, auto, runtime)
1294
1295 DEFPARAM (PARAM_PARLOOPS_MIN_PER_THREAD,
1296           "parloops-min-per-thread",
1297           "Minimum number of iterations per thread of an innermost "
1298           "parallelized loop.",
1299           100, 2, 0)
1300
1301 DEFPARAM (PARAM_MAX_SSA_NAME_QUERY_DEPTH,
1302           "max-ssa-name-query-depth",
1303           "Maximum recursion depth allowed when querying a property of an"
1304           " SSA name.",
1305           3, 1, 10)
1306
1307 DEFPARAM (PARAM_MAX_RTL_IF_CONVERSION_INSNS,
1308           "max-rtl-if-conversion-insns",
1309           "Maximum number of insns in a basic block to consider for RTL "
1310           "if-conversion.",
1311           10, 0, 99)
1312
1313 DEFPARAM (PARAM_MAX_RTL_IF_CONVERSION_PREDICTABLE_COST,
1314           "max-rtl-if-conversion-predictable-cost",
1315           "Maximum permissible cost for the sequence that would be "
1316           "generated by the RTL if-conversion pass for a branch that "
1317           "is considered predictable.",
1318           20, 0, 200)
1319
1320 DEFPARAM (PARAM_MAX_RTL_IF_CONVERSION_UNPREDICTABLE_COST,
1321           "max-rtl-if-conversion-unpredictable-cost",
1322           "Maximum permissible cost for the sequence that would be "
1323           "generated by the RTL if-conversion pass for a branch that "
1324           "is considered unpredictable.",
1325           40, 0, 200)
1326
1327 DEFPARAM (PARAM_HSA_GEN_DEBUG_STORES,
1328           "hsa-gen-debug-stores",
1329           "Level of hsa debug stores verbosity.",
1330           0, 0, 1)
1331
1332 DEFPARAM (PARAM_MAX_SPECULATIVE_DEVIRT_MAYDEFS,
1333           "max-speculative-devirt-maydefs",
1334           "Maximum number of may-defs visited when devirtualizing "
1335           "speculatively.", 50, 0, 0)
1336
1337 DEFPARAM (PARAM_MAX_VRP_SWITCH_ASSERTIONS,
1338           "max-vrp-switch-assertions",
1339           "Maximum number of assertions to add along the default "
1340           "edge of a switch statement during VRP.",
1341           10, 0, 0)
1342
1343 DEFPARAM (PARAM_VECT_EPILOGUES_NOMASK,
1344           "vect-epilogues-nomask",
1345           "Enable loop epilogue vectorization using smaller vector size.",
1346           0, 0, 1)
1347
1348 DEFPARAM(PARAM_UNROLL_JAM_MIN_PERCENT,
1349          "unroll-jam-min-percent",
1350          "Minimum percentage of memrefs that must go away for unroll-and-jam to be considered profitable.",
1351          1, 0, 100)
1352
1353 DEFPARAM(PARAM_UNROLL_JAM_MAX_UNROLL,
1354          "unroll-jam-max-unroll",
1355          "Maximum unroll factor for the unroll-and-jam transformation.",
1356          4, 0, 0)
1357
1358 DEFPARAM(PARAM_AVOID_FMA_MAX_BITS,
1359          "avoid-fma-max-bits",
1360          "Maximum number of bits for which we avoid creating FMAs.",
1361          0, 0, 512)
1362
1363 DEFPARAM(PARAM_LOGICAL_OP_NON_SHORT_CIRCUIT,
1364          "logical-op-non-short-circuit",
1365          "True if a non-short-circuit operation is optimal.",
1366          -1, -1, 1)
1367
1368 DEFPARAM(PARAM_LOOP_VERSIONING_MAX_INNER_INSNS,
1369          "loop-versioning-max-inner-insns",
1370          "The maximum number of instructions in an inner loop that is being"
1371          " considered for versioning.",
1372          200, 0, 0)
1373
1374 DEFPARAM(PARAM_LOOP_VERSIONING_MAX_OUTER_INSNS,
1375          "loop-versioning-max-outer-insns",
1376          "The maximum number of instructions in an outer loop that is being"
1377          " considered for versioning, on top of the instructions in inner"
1378          " loops.",
1379          100, 0, 0)
1380
1381 /*
1382
1383 Local variables:
1384 mode:c
1385 End:
1386 */