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 with -O3 and -Ofast.",
  55           15, 0, 100)
  56
  57 DEFPARAM (PARAM_INLINE_MIN_SPEEDUP_O2,
  58           "inline-min-speedup-O2",
  59           "The minimal estimated speedup allowing inliner to ignore inline-insns-single and inline-insns-auto.",
  60           30, 0, 100)
  61
  62 /* The single function inlining limit. This is the maximum size
  63    of a function counted in internal gcc instructions (not in
  64    real machine instructions) that is eligible for inlining
  65    by the tree inliner.
  66    Only functions marked inline (or methods defined in the class
  67    definition for C++) are affected by this.
  68    There are more restrictions to inlining: If inlined functions
  69    call other functions, the already inlined instructions are
  70    counted and once the recursive inline limit (see
  71    "max-inline-insns" parameter) is exceeded, the acceptable size
  72    gets decreased.  */
  73 DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
  74           "max-inline-insns-single",
  75           "The maximum number of instructions in a single function eligible for inlining with -O3 and -Ofast.",
  76           200, 0, 0)
  77
  78 DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE_O2,
  79           "max-inline-insns-single-O2",
  80           "The maximum number of instructions in a single function eligible for inlining.",
  81           30, 0, 0)
  82
  83 /* The single function inlining limit for functions that are
  84    inlined by virtue of -finline-functions (-O3).
  85    This limit should be chosen to be below or equal to the limit
  86    that is applied to functions marked inlined (or defined in the
  87    class declaration in C++) given by the "max-inline-insns-single"
  88    parameter.
  89    The default value is 30.  */
  90 DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
  91           "max-inline-insns-auto",
  92           "The maximum number of instructions when automatically inlining with -O3 and -Ofast.",
  93           30, 0, 0)
  94
  95 DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO_O2,
  96           "max-inline-insns-auto-O2",
  97           "The maximum number of instructions when automatically inlining.",
  98           15, 0, 0)
  99
 100 DEFPARAM (PARAM_MAX_INLINE_INSNS_SMALL,
 101           "max-inline-insns-small",
 102           "The maximum number of instructions when automatically inlining small functions.",
 103           0, 0, 0)
 104
 105 DEFPARAM (PARAM_INLINE_HEURISTICS_HINT_PERCENT,
 106           "inline-heuristics-hint-percent",
 107           "The scale (in percents) applied to inline-insns-single and auto limits when heuristics hints that inlining is very profitable with -O3 and -Ofast.",
 108           1600, 100, 1000000)
 109
 110 DEFPARAM (PARAM_INLINE_HEURISTICS_HINT_PERCENT_O2,
 111           "inline-heuristics-hint-percent-O2",
 112           "The scale (in percents) applied to inline-insns-single and auto limits when heuristics hints that inlining is very profitable.",
 113           200, 100, 1000000)
 114
 115 DEFPARAM (PARAM_MAX_INLINE_INSNS_SIZE,
 116           "max-inline-insns-size",
 117           "The maximum number of instructions when inlining for size.",
 118           0, 0, 0)
 119
 120 DEFPARAM (PARAM_UNINLINED_FUNCTION_INSNS,
 121           "uninlined-function-insns",
 122           "Instruction accounted for function prologue, epilogue and other"
 123           " overhead.",
 124           2, 0, 1000000)
 125
 126 DEFPARAM (PARAM_UNINLINED_FUNCTION_TIME,
 127           "uninlined-function-time",
 128           "Time accounted for function prologue, epilogue and other"
 129           " overhead.",
 130           0, 0, 1000000)
 131
 132 DEFPARAM (PARAM_UNINLINED_FUNCTION_THUNK_INSNS,
 133           "uninlined-thunk-insns",
 134           "Instruction accounted for function thunk overhead.",
 135           2, 0, 1000000)
 136
 137 DEFPARAM (PARAM_UNINLINED_FUNCTION_THUNK_TIME,
 138           "uninlined-thunk-time",
 139           "Time accounted for function thunk overhead.",
 140           2, 0, 1000000)
 141
 142 DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
 143           "max-inline-insns-recursive",
 144           "The maximum number of instructions inline function can grow to via recursive inlining.",
 145           450, 0, 0)
 146
 147 DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
 148           "max-inline-insns-recursive-auto",
 149           "The maximum number of instructions non-inline function can grow to via recursive inlining.",
 150           450, 0, 0)
 151
 152 DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
 153           "max-inline-recursive-depth",
 154           "The maximum depth of recursive inlining for inline functions.",
 155           8, 0, 0)
 156
 157 DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
 158           "max-inline-recursive-depth-auto",
 159           "The maximum depth of recursive inlining for non-inline functions.",
 160           8, 0, 0)
 161
 162 DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
 163           "min-inline-recursive-probability",
 164           "Inline recursively only when the probability of call being executed exceeds the parameter.",
 165           10, 0, 0)
 166
 167 /* Limit of iterations of early inliner.  This basically bounds number of
 168    nested indirect calls early inliner can resolve.  Deeper chains are still
 169    handled by late inlining.  */
 170 DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS,
 171           "max-early-inliner-iterations",
 172           "The maximum number of nested indirect inlining performed by early inliner.",
 173           1, 0, 0)
 174
 175 /* Limit on probability of entry BB.  */
 176 DEFPARAM (PARAM_COMDAT_SHARING_PROBABILITY,
 177           "comdat-sharing-probability",
 178           "Probability that COMDAT function will be shared with different compilation unit.",
 179           20, 0, 0)
 180
 181 /* Limit on probability of entry BB.  */
 182 DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY,
 183           "partial-inlining-entry-probability",
 184           "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen.",
 185           70, 0, 100)
 186
 187 /* Limit the number of expansions created by the variable expansion
 188    optimization to avoid register pressure.  */
 189 DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
 190           "max-variable-expansions-in-unroller",
 191           "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling.",
 192           1, 0, 0)
 193
 194 /* Limit loop autovectorization to loops with large enough iteration count.  */
 195 DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND,
 196           "min-vect-loop-bound",
 197           "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization.",
 198           0, 0, 0)
 199
 200 /* The maximum number of instructions to consider when looking for an
 201    instruction to fill a delay slot.  If more than this arbitrary
 202    number of instructions is searched, the time savings from filling
 203    the delay slot will be minimal so stop searching.  Increasing
 204    values mean more aggressive optimization, making the compile time
 205    increase with probably small improvement in executable run time.  */
 206 DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
 207           "max-delay-slot-insn-search",
 208           "The maximum number of instructions to consider to fill a delay slot.",
 209           100, 0, 0)
 210
 211 /* When trying to fill delay slots, the maximum number of instructions
 212    to consider when searching for a block with valid live register
 213    information.  Increasing this arbitrarily chosen value means more
 214    aggressive optimization, increasing the compile time.  This
 215    parameter should be removed when the delay slot code is rewritten
 216    to maintain the control-flow graph.  */
 217 DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
 218          "max-delay-slot-live-search",
 219          "The maximum number of instructions to consider to find accurate live register information.",
 220          333, 0, 0)
 221
 222 /* This parameter limits the number of branch elements that the
 223    scheduler will track anti-dependencies through without resetting
 224    the tracking mechanism.  Large functions with few calls or barriers
 225    can generate lists containing many 1000's of dependencies.  Generally
 226    the compiler either uses all available memory, or runs for far too long.  */
 227 DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
 228          "max-pending-list-length",
 229          "The maximum length of scheduling's pending operations list.",
 230          32, 0, 0)
 231
 232 /* This parameter limits the number of backtracking attempts when using the
 233    haifa scheduler for modulo scheduling.  */
 234 DEFPARAM(PARAM_MAX_MODULO_BACKTRACK_ATTEMPTS,
 235          "max-modulo-backtrack-attempts",
 236          "The maximum number of backtrack attempts the scheduler should make when modulo scheduling a loop.",
 237          40, 0, 0)
 238
 239 DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
 240          "large-function-insns",
 241          "The size of function body to be considered large.",
 242          2700, 0, 0)
 243 DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
 244          "large-function-growth",
 245          "Maximal growth due to inlining of large function (in percent).",
 246          100, 0, 0)
 247 DEFPARAM(PARAM_LARGE_UNIT_INSNS,
 248          "large-unit-insns",
 249          "The size of translation unit to be considered large.",
 250          10000, 0, 0)
 251 DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
 252          "inline-unit-growth",
 253          "How much can given compilation unit grow because of the inlining (in percent).",
 254          40, 0, 0)
 255 DEFPARAM(PARAM_IPCP_UNIT_GROWTH,
 256          "ipcp-unit-growth",
 257          "How much can given compilation unit grow because of the interprocedural constant propagation (in percent).",
 258          10, 0, 0)
 259 DEFPARAM(PARAM_EARLY_INLINING_INSNS,
 260          "early-inlining-insns",
 261          "Maximal estimated growth of function body caused by early inlining of single call with -O3 and -Ofast.",
 262          14, 0, 0)
 263 DEFPARAM(PARAM_EARLY_INLINING_INSNS_O2,
 264          "early-inlining-insns-O2",
 265          "Maximal estimated growth of function body caused by early inlining of single call with -O1 and -O2.",
 266          6, 0, 0)
 267 DEFPARAM(PARAM_LARGE_STACK_FRAME,
 268          "large-stack-frame",
 269          "The size of stack frame to be considered large.",
 270          256, 0, 0)
 271 DEFPARAM(PARAM_STACK_FRAME_GROWTH,
 272          "large-stack-frame-growth",
 273          "Maximal stack frame growth due to inlining (in percent).",
 274          1000, 0, 0)
 275
 276 /* Keep these up to date with those in configure.ac.  */
 277 DEFPARAM(PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE,
 278          "stack-clash-protection-guard-size",
 279          "Size of the stack guard expressed as a power of two in bytes.",
 280          12, 12, 30)
 281
 282 DEFPARAM(PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL,
 283          "stack-clash-protection-probe-interval",
 284          "Interval in which to probe the stack expressed as a power of two in bytes.",
 285          12, 10, 16)
 286
 287 /* The GCSE optimization will be disabled if it would require
 288    significantly more memory than this value.  */
 289 DEFPARAM(PARAM_MAX_GCSE_MEMORY,
 290          "max-gcse-memory",
 291          "The maximum amount of memory to be allocated by GCSE.",
 292          128 * 1024 * 1024, 0, 0)
 293
 294 /* The GCSE optimization of an expression will avoided if the ratio of
 295    insertions to deletions is greater than this value.  */
 296 DEFPARAM(PARAM_MAX_GCSE_INSERTION_RATIO,
 297          "max-gcse-insertion-ratio",
 298          "The maximum ratio of insertions to deletions of expressions in GCSE.",
 299          20, 0, 0)
 300
 301 /* This is the threshold ratio when to perform partial redundancy
 302    elimination after reload. We perform partial redundancy elimination
 303    when the following holds:
 304    (Redundant load execution count)
 305    ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
 306    (Added loads execution count)                                          */
 307 DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
 308         "gcse-after-reload-partial-fraction",
 309         "The threshold ratio for performing partial redundancy elimination after reload.",
 310         3, 0, 0)
 311 /* This is the threshold ratio of the critical edges execution count compared to
 312    the redundant loads execution count that permits performing the load
 313    redundancy elimination in gcse after reload.  */
 314 DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
 315         "gcse-after-reload-critical-fraction",
 316         "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload.",
 317         10, 0, 0)
 318
 319 /* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor
 320    to calculate maximum distance for which an expression is allowed to move
 321    from its rtx_cost.  */
 322 DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO,
 323          "gcse-cost-distance-ratio",
 324          "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations.",
 325          10, 0, 0)
 326 /* GCSE won't restrict distance for which an expression with rtx_cost greater
 327    than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move.  */
 328 DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST,
 329          "gcse-unrestricted-cost",
 330          "Cost at which GCSE optimizations will not constraint the distance an expression can travel.",
 331          3, 0, 0)
 332
 333 /* How deep from a given basic block the dominator tree should be searched
 334    for expressions to hoist to the block.  The value of 0 will avoid limiting
 335    the search.  */
 336 DEFPARAM(PARAM_MAX_HOIST_DEPTH,
 337          "max-hoist-depth",
 338          "Maximum depth of search in the dominator tree for expressions to hoist.",
 339          30, 0, 0)
 340
 341
 342 /* When synthesizing expnonentiation by a real constant operations using square
 343    roots, this controls how deep sqrt chains we are willing to generate.  */
 344 DEFPARAM(PARAM_MAX_POW_SQRT_DEPTH,
 345          "max-pow-sqrt-depth",
 346          "Maximum depth of sqrt chains to use when synthesizing exponentiation by a real constant.",
 347          5, 1, 32)
 348
 349 /* This parameter limits the number of insns in a loop that will be unrolled,
 350    and by how much the loop is unrolled.
 351
 352    This limit should be at most half of the peeling limits:  loop unroller
 353    decides to not unroll loops that iterate fewer than 2*number of allowed
 354    unrollings and thus we would have loops that are neither peeled or unrolled
 355    otherwise.  */
 356 DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
 357          "max-unrolled-insns",
 358          "The maximum number of instructions to consider to unroll in a loop.",
 359          200, 0, 0)
 360 /* This parameter limits how many times the loop is unrolled depending
 361    on number of insns really executed in each iteration.  */
 362 DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
 363          "max-average-unrolled-insns",
 364          "The maximum number of instructions to consider to unroll in a loop on average.",
 365          80, 0, 0)
 366 /* The maximum number of unrollings of a single loop.  */
 367 DEFPARAM(PARAM_MAX_UNROLL_TIMES,
 368         "max-unroll-times",
 369         "The maximum number of unrollings of a single loop.",
 370         8, 0, 0)
 371 /* The maximum number of insns of a peeled loop.  */
 372 DEFPARAM(PARAM_MAX_PEELED_INSNS,
 373         "max-peeled-insns",
 374         "The maximum number of insns of a peeled loop.",
 375         100, 0, 0)
 376 /* The maximum number of peelings of a single loop.  */
 377 DEFPARAM(PARAM_MAX_PEEL_TIMES,
 378         "max-peel-times",
 379         "The maximum number of peelings of a single loop.",
 380         16, 0, 0)
 381 /* The maximum number of peelings of a single loop that is peeled completely.  */
 382 DEFPARAM(PARAM_MAX_PEEL_BRANCHES,
 383         "max-peel-branches",
 384         "The maximum number of branches on the path through the peeled sequence.",
 385         32, 0, 0)
 386 /* The maximum number of insns of a peeled loop.  */
 387 DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
 388         "max-completely-peeled-insns",
 389         "The maximum number of insns of a completely peeled loop.",
 390         200, 0, 0)
 391 /* The maximum number of peelings of a single loop that is peeled completely.  */
 392 DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
 393         "max-completely-peel-times",
 394         "The maximum number of peelings of a single loop that is peeled completely.",
 395         16, 0, 0)
 396 /* The maximum number of insns of a peeled loop that rolls only once.  */
 397 DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
 398         "max-once-peeled-insns",
 399         "The maximum number of insns of a peeled loop that rolls only once.",
 400         400, 0, 0)
 401 /* The maximum depth of a loop nest we completely peel.  */
 402 DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS,
 403          "max-completely-peel-loop-nest-depth",
 404          "The maximum depth of a loop nest we completely peel.",
 405          8, 0, 0)
 406
 407 /* The maximum number of insns of an unswitched loop.  */
 408 DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
 409         "max-unswitch-insns",
 410         "The maximum number of insns of an unswitched loop.",
 411         50, 0, 0)
 412 /* The maximum level of recursion in unswitch_single_loop.  */
 413 DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
 414         "max-unswitch-level",
 415         "The maximum number of unswitchings in a single loop.",
 416         3, 0, 0)
 417
 418 /* The maximum number of insns in loop header duplicated by the copy loop
 419    headers pass.  */
 420 DEFPARAM(PARAM_MAX_LOOP_HEADER_INSNS,
 421         "max-loop-header-insns",
 422         "The maximum number of insns in loop header duplicated by the copy loop headers pass.",
 423         20, 0, 0)
 424
 425 /* The maximum number of iterations of a loop the brute force algorithm
 426    for analysis of # of iterations of the loop tries to evaluate.  */
 427 DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
 428         "max-iterations-to-track",
 429         "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates.",
 430         1000, 0, 0)
 431 /* A cutoff to avoid costly computations of the number of iterations in
 432    the doloop transformation.  */
 433 DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST,
 434         "max-iterations-computation-cost",
 435         "Bound on the cost of an expression to compute the number of iterations.",
 436         10, 0, 0)
 437
 438 /* This parameter is used to tune SMS MAX II calculations.  */
 439 DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
 440          "sms-max-ii-factor",
 441          "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop.",
 442          100, 0, 0)
 443 /* The minimum value of stage count that swing modulo scheduler will generate.  */
 444 DEFPARAM(PARAM_SMS_MIN_SC,
 445         "sms-min-sc",
 446         "The minimum value of stage count that swing modulo scheduler will generate.",
 447         2, 1, 1)
 448 DEFPARAM(PARAM_SMS_DFA_HISTORY,
 449          "sms-dfa-history",
 450          "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA.",
 451          0, 0, 0)
 452 DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
 453          "sms-loop-average-count-threshold",
 454          "A threshold on the average loop count considered by the swing modulo scheduler.",
 455          0, 0, 0)
 456
 457 DEFPARAM(HOT_BB_COUNT_FRACTION,
 458          "hot-bb-count-fraction",
 459          "The denominator n of fraction 1/n of the maximal execution count of "
 460          "a basic block in the entire program that a basic block needs to at "
 461          "least have in order to be considered hot (used in non-LTO mode).",
 462          10000, 0, 0)
 463
 464 DEFPARAM(HOT_BB_COUNT_WS_PERMILLE,
 465          "hot-bb-count-ws-permille",
 466          "The number of most executed permilles of the profiled execution of "
 467          "the entire program to which the execution count of a basic block "
 468          "must be part of in order to be considered hot (used in LTO mode).",
 469          990, 0, 1000)
 470
 471 DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
 472          "hot-bb-frequency-fraction",
 473          "The denominator n of fraction 1/n of the execution frequency of the "
 474          "entry block of a function that a basic block of this function needs "
 475          "to at least have in order to be considered hot.",
 476          1000, 0, 0)
 477
 478 DEFPARAM(UNLIKELY_BB_COUNT_FRACTION,
 479          "unlikely-bb-count-fraction",
 480          "The denominator n of fraction 1/n of the number of profiled runs of "
 481          "the entire program below which the execution count of a basic block "
 482          "must be in order for the basic block to be considered unlikely.",
 483          20, 0, 0)
 484
 485 DEFPARAM (PARAM_ALIGN_THRESHOLD,
 486           "align-threshold",
 487           "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment.",
 488           100, 1, 0)
 489
 490 DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS,
 491           "align-loop-iterations",
 492           "Loops iterating at least selected number of iterations will get "
 493           "loop alignment.", 4, 0, 0)
 494
 495 /* For guessed profiles, the loops having unknown number of iterations
 496    are predicted to iterate relatively few (10) times at average.
 497    For functions containing one loop with large known number of iterations
 498    and other loops having unbounded loops we would end up predicting all
 499    the other loops cold that is not usually the case.  So we need to artificially
 500    flatten the profile.
 501
 502    We need to cut the maximal predicted iterations to large enough iterations
 503    so the loop appears important, but safely within maximum hotness
 504    range.  */
 505
 506 DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
 507          "max-predicted-iterations",
 508          "The maximum number of loop iterations we predict statically.",
 509          100, 0, 0)
 510
 511 /* This parameter controls the probability of builtin_expect. The default
 512    value is 90%. This empirical value is obtained through the weighted
 513    probability of FDO counters (with the FDO count value as the weight)
 514    in some real world programs:
 515    (1) Google performance test benchmarks: the probability is 0.9081.
 516    (2) Linux 3.3 kernel running Google search workload: the probability
 517    is 0.8717.  */
 518
 519 DEFPARAM(BUILTIN_EXPECT_PROBABILITY,
 520          "builtin-expect-probability",
 521          "Set the estimated probability in percentage for builtin expect. The default value is 90% probability.",
 522          90, 0, 100)
 523 DEFPARAM(BUILTIN_STRING_CMP_INLINE_LENGTH,
 524          "builtin-string-cmp-inline-length",
 525          "The maximum length of a constant string for a builtin string cmp call eligible for inlining. The default value is 3.",
 526          3, 0, 100)
 527 DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
 528          "tracer-dynamic-coverage-feedback",
 529          "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available.",
 530          95, 0, 100)
 531 DEFPARAM(TRACER_DYNAMIC_COVERAGE,
 532          "tracer-dynamic-coverage",
 533          "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available.",
 534          75, 0, 100)
 535 DEFPARAM(TRACER_MAX_CODE_GROWTH,
 536          "tracer-max-code-growth",
 537          "Maximal code growth caused by tail duplication (in percent).",
 538          100, 0, 0)
 539 DEFPARAM(TRACER_MIN_BRANCH_RATIO,
 540          "tracer-min-branch-ratio",
 541          "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent).",
 542          10, 0, 100)
 543 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
 544          "tracer-min-branch-probability-feedback",
 545          "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available.",
 546          80, 0, 100)
 547 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
 548          "tracer-min-branch-probability",
 549          "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available.",
 550          50, 0, 100)
 551
 552 /* The maximum number of incoming edges to consider for crossjumping.  */
 553 DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
 554          "max-crossjump-edges",
 555          "The maximum number of incoming edges to consider for crossjumping.",
 556          100, 0, 0)
 557
 558 /* The minimum number of matching instructions to consider for crossjumping.  */
 559 DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
 560      "min-crossjump-insns",
 561      "The minimum number of matching instructions to consider for crossjumping.",
 562      5, 1, 0)
 563
 564 /* The maximum number expansion factor when copying basic blocks.  */
 565 DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
 566      "max-grow-copy-bb-insns",
 567      "The maximum expansion factor when copying basic blocks.",
 568      8, 0, 0)
 569
 570 /* The maximum number of insns to duplicate when unfactoring computed gotos.  */
 571 DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
 572      "max-goto-duplication-insns",
 573      "The maximum number of insns to duplicate when unfactoring computed gotos.",
 574      8, 0, 0)
 575
 576 /* The maximum length of path considered in cse.  */
 577 DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
 578          "max-cse-path-length",
 579          "The maximum length of path considered in cse.",
 580          10, 1, 0)
 581 DEFPARAM(PARAM_MAX_CSE_INSNS,
 582          "max-cse-insns",
 583          "The maximum instructions CSE process before flushing.",
 584          1000, 0, 0)
 585
 586 /* The cost of expression in loop invariant motion that is considered
 587    expensive.  */
 588 DEFPARAM(PARAM_LIM_EXPENSIVE,
 589          "lim-expensive",
 590          "The minimum cost of an expensive expression in the loop invariant motion.",
 591          20, 0, 0)
 592
 593 /* Bound on number of candidates for induction variables below that
 594    all candidates are considered for each use in induction variable
 595    optimizations.  */
 596
 597 DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
 598          "iv-consider-all-candidates-bound",
 599          "Bound on number of candidates below that all candidates are considered in iv optimizations.",
 600          40, 0, 0)
 601
 602 /* The induction variable optimizations give up on loops that contain more
 603    induction variable uses.  */
 604
 605 DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
 606          "iv-max-considered-uses",
 607          "Bound on number of iv uses in loop optimized in iv optimizations.",
 608          250, 0, 0)
 609
 610 /* If there are at most this number of ivs in the set, try removing unnecessary
 611    ivs from the set always.  */
 612
 613 DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
 614          "iv-always-prune-cand-set-bound",
 615          "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization.",
 616          10, 0, 0)
 617
 618 DEFPARAM(PARAM_AVG_LOOP_NITER,
 619          "avg-loop-niter",
 620          "Average number of iterations of a loop.",
 621          10, 1, 0)
 622
 623 DEFPARAM(PARAM_DSE_MAX_OBJECT_SIZE,
 624          "dse-max-object-size",
 625          "Maximum size (in bytes) of objects tracked bytewise by dead store elimination.",
 626          256, 0, 0)
 627
 628 DEFPARAM(PARAM_DSE_MAX_ALIAS_QUERIES_PER_STORE,
 629          "dse-max-alias-queries-per-store",
 630          "Maximum number of queries into the alias oracle per store.",
 631          256, 0, 0)
 632
 633 DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
 634          "scev-max-expr-size",
 635          "Bound on size of expressions used in the scalar evolutions analyzer.",
 636          100, 0, 0)
 637
 638 DEFPARAM(PARAM_SCEV_MAX_EXPR_COMPLEXITY,
 639          "scev-max-expr-complexity",
 640          "Bound on the complexity of the expressions in the scalar evolutions analyzer.",
 641          10, 0, 0)
 642
 643 DEFPARAM (PARAM_MAX_TREE_IF_CONVERSION_PHI_ARGS,
 644           "max-tree-if-conversion-phi-args",
 645           "Maximum number of arguments in a PHI supported by TREE if-conversion "
 646           "unless the loop is marked with simd pragma.",
 647           4, 2, 0)
 648
 649 DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS,
 650          "vect-max-version-for-alignment-checks",
 651          "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check.",
 652          6, 0, 0)
 653
 654 DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS,
 655          "vect-max-version-for-alias-checks",
 656          "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alias check.",
 657          10, 0, 0)
 658
 659 DEFPARAM(PARAM_VECT_MAX_PEELING_FOR_ALIGNMENT,
 660          "vect-max-peeling-for-alignment",
 661          "Maximum number of loop peels to enhance alignment of data references in a loop.",
 662          -1, -1, 64)
 663
 664 DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
 665          "max-cselib-memory-locations",
 666          "The maximum memory locations recorded by cselib.",
 667          500, 0, 0)
 668
 669 #ifdef ENABLE_GC_ALWAYS_COLLECT
 670 # define GGC_MIN_EXPAND_DEFAULT 0
 671 # define GGC_MIN_HEAPSIZE_DEFAULT 0
 672 #else
 673 # define GGC_MIN_EXPAND_DEFAULT 30
 674 # define GGC_MIN_HEAPSIZE_DEFAULT 4096
 675 #endif
 676
 677 DEFPARAM(GGC_MIN_EXPAND,
 678          "ggc-min-expand",
 679          "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap.",
 680          GGC_MIN_EXPAND_DEFAULT, 0, 0)
 681
 682 DEFPARAM(GGC_MIN_HEAPSIZE,
 683          "ggc-min-heapsize",
 684          "Minimum heap size before we start collecting garbage, in kilobytes.",
 685          GGC_MIN_HEAPSIZE_DEFAULT, 0, 0)
 686
 687 #undef GGC_MIN_EXPAND_DEFAULT
 688 #undef GGC_MIN_HEAPSIZE_DEFAULT
 689
 690 DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
 691          "max-reload-search-insns",
 692          "The maximum number of instructions to search backward when looking for equivalent reload.",
 693          100, 0, 0)
 694
 695 DEFPARAM(PARAM_SINK_FREQUENCY_THRESHOLD,
 696          "sink-frequency-threshold",
 697          "Target block's relative execution frequency (as a percentage) required to sink a statement.",
 698          75, 0, 100)
 699
 700 DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS,
 701          "max-sched-region-blocks",
 702          "The maximum number of blocks in a region to be considered for interblock scheduling.",
 703          10, 0, 0)
 704
 705 DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS,
 706          "max-sched-region-insns",
 707          "The maximum number of insns in a region to be considered for interblock scheduling.",
 708          100, 0, 0)
 709
 710 DEFPARAM(PARAM_MAX_PIPELINE_REGION_BLOCKS,
 711          "max-pipeline-region-blocks",
 712          "The maximum number of blocks in a region to be considered for interblock scheduling.",
 713          15, 0, 0)
 714
 715 DEFPARAM(PARAM_MAX_PIPELINE_REGION_INSNS,
 716          "max-pipeline-region-insns",
 717          "The maximum number of insns in a region to be considered for interblock scheduling.",
 718          200, 0, 0)
 719
 720 DEFPARAM(PARAM_MIN_SPEC_PROB,
 721          "min-spec-prob",
 722          "The minimum probability of reaching a source block for interblock speculative scheduling.",
 723          40, 0, 0)
 724
 725 DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS,
 726          "max-sched-extend-regions-iters",
 727          "The maximum number of iterations through CFG to extend regions.",
 728          0, 0, 0)
 729
 730 DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY,
 731          "max-sched-insn-conflict-delay",
 732          "The maximum conflict delay for an insn to be considered for speculative motion.",
 733          3, 1, 10)
 734
 735 DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF,
 736          "sched-spec-prob-cutoff",
 737          "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.",
 738          40, 0, 100)
 739
 740 DEFPARAM(PARAM_SCHED_STATE_EDGE_PROB_CUTOFF,
 741          "sched-state-edge-prob-cutoff",
 742          "The minimum probability an edge must have for the scheduler to save its state across it.",
 743          10, 0, 100)
 744
 745 DEFPARAM(PARAM_SELSCHED_MAX_LOOKAHEAD,
 746          "selsched-max-lookahead",
 747          "The maximum size of the lookahead window of selective scheduling.",
 748          50, 0, 0)
 749
 750 DEFPARAM(PARAM_SELSCHED_MAX_SCHED_TIMES,
 751          "selsched-max-sched-times",
 752          "Maximum number of times that an insn could be scheduled.",
 753          2, 1, 0)
 754
 755 DEFPARAM(PARAM_SELSCHED_INSNS_TO_RENAME,
 756          "selsched-insns-to-rename",
 757          "Maximum number of instructions in the ready list that are considered eligible for renaming.",
 758          2, 0, 0)
 759
 760 DEFPARAM (PARAM_SCHED_MEM_TRUE_DEP_COST,
 761           "sched-mem-true-dep-cost",
 762           "Minimal distance between possibly conflicting store and load.",
 763           1, 0, 0)
 764
 765 DEFPARAM (PARAM_SCHED_AUTOPREF_QUEUE_DEPTH,
 766           "sched-autopref-queue-depth",
 767           "Hardware autoprefetcher scheduler model control flag.  Number of lookahead cycles the model looks into; at '0' only enable instruction sorting heuristic.  Disabled by default.",
 768           -1, 0, 0)
 769
 770 DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
 771          "max-last-value-rtl",
 772          "The maximum number of RTL nodes that can be recorded as combiner's last value.",
 773          10000, 0, 0)
 774
 775 DEFPARAM(PARAM_MAX_COMBINE_INSNS,
 776          "max-combine-insns",
 777          "The maximum number of insns combine tries to combine.",
 778          4, 2, 4)
 779
 780 /* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
 781    {signed,unsigned} integral types.  This determines N.
 782    Experimentation shows 251 to be a good value that generates the
 783    least amount of garbage for allocating the TREE_VEC storage.  */
 784 DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
 785           "integer-share-limit",
 786           "The upper bound for sharing integer constants.",
 787           251, 2, 2)
 788
 789 DEFPARAM (PARAM_SSP_BUFFER_SIZE,
 790           "ssp-buffer-size",
 791           "The lower bound for a buffer to be considered for stack smashing protection.",
 792           8, 1, 0)
 793
 794 DEFPARAM (PARAM_MIN_SIZE_FOR_STACK_SHARING,
 795           "min-size-for-stack-sharing",
 796           "The minimum size of variables taking part in stack slot sharing "
 797           "when not optimizing.",
 798           32, 0, 0)
 799
 800 /* When we thread through a block we have to make copies of the
 801    statements within the block.  Clearly for large blocks the code
 802    duplication is bad.
 803
 804    PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number
 805    of statements and PHI nodes allowed in a block which is going to
 806    be duplicated for thread jumping purposes.
 807
 808    Some simple analysis showed that more than 99% of the jump
 809    threading opportunities are for blocks with less than 15
 810    statements.  So we can get the benefits of jump threading
 811    without excessive code bloat for pathological cases with the
 812    throttle set at 15 statements.  */
 813 DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS,
 814           "max-jump-thread-duplication-stmts",
 815           "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps.",
 816           15, 0, 0)
 817
 818 /* This is the maximum number of fields a variable may have before the pointer analysis machinery
 819    will stop trying to treat it in a field-sensitive manner.
 820    There are programs out there with thousands of fields per structure, and handling them
 821    field-sensitively is not worth the cost.  */
 822 DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE,
 823           "max-fields-for-field-sensitive",
 824           "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable.",
 825           0, 0, 0)
 826
 827 DEFPARAM(PARAM_MAX_SCHED_READY_INSNS,
 828          "max-sched-ready-insns",
 829          "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass.",
 830          100, 1, 0)
 831
 832 /* This is the maximum number of active local stores RTL DSE will consider.  */
 833 DEFPARAM (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES,
 834           "max-dse-active-local-stores",
 835           "Maximum number of active local stores in RTL dead store elimination.",
 836           5000, 0, 0)
 837
 838 /* Prefetching and cache-optimizations related parameters.  Default values are
 839    usually set by machine description.  */
 840
 841 /* The number of insns executed before prefetch is completed.  */
 842
 843 DEFPARAM (PARAM_PREFETCH_LATENCY,
 844          "prefetch-latency",
 845          "The number of insns executed before prefetch is completed.",
 846          200, 0, 0)
 847
 848 /* The number of prefetches that can run at the same time.  */
 849
 850 DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES,
 851           "simultaneous-prefetches",
 852           "The number of prefetches that can run at the same time.",
 853           3, 0, 0)
 854
 855 /* The size of L1 cache in kB.  */
 856
 857 DEFPARAM (PARAM_L1_CACHE_SIZE,
 858           "l1-cache-size",
 859           "The size of L1 cache.",
 860           64, 0, 0)
 861
 862 /* The size of L1 cache line in bytes.  */
 863
 864 DEFPARAM (PARAM_L1_CACHE_LINE_SIZE,
 865           "l1-cache-line-size",
 866           "The size of L1 cache line.",
 867           32, 0, 0)
 868
 869 /* The size of L2 cache in kB.  */
 870
 871 DEFPARAM (PARAM_L2_CACHE_SIZE,
 872           "l2-cache-size",
 873           "The size of L2 cache.",
 874           512, 0, 0)
 875
 876 /* Whether software prefetch hints should be issued for non-constant
 877    strides.  */
 878
 879 DEFPARAM (PARAM_PREFETCH_DYNAMIC_STRIDES,
 880           "prefetch-dynamic-strides",
 881           "Whether software prefetch hints should be issued for non-constant "
 882           "strides.",
 883           1, 0, 1)
 884
 885 /* The minimum constant stride beyond which we should use prefetch hints
 886    for.  */
 887
 888 DEFPARAM (PARAM_PREFETCH_MINIMUM_STRIDE,
 889           "prefetch-minimum-stride",
 890           "The minimum constant stride beyond which we should use prefetch "
 891           "hints for.",
 892           -1, 0, 0)
 893
 894 /* Maximum number of statements in loop nest for loop interchange.  */
 895
 896 DEFPARAM (PARAM_LOOP_INTERCHANGE_MAX_NUM_STMTS,
 897           "loop-interchange-max-num-stmts",
 898           "The maximum number of stmts in loop nest for loop interchange.",
 899           64, 0, 0)
 900
 901 /* Minimum stride ratio for loop interchange to be profitiable.  */
 902
 903 DEFPARAM (PARAM_LOOP_INTERCHANGE_STRIDE_RATIO,
 904           "loop-interchange-stride-ratio",
 905           "The minimum stride ratio for loop interchange to be profitable.",
 906           2, 0, 0)
 907
 908 /* Whether we should use canonical types rather than deep "structural"
 909    type checking.  Setting this value to 1 (the default) improves
 910    compilation performance in the C++ and Objective-C++ front end;
 911    this value should only be set to zero to work around bugs in the
 912    canonical type system by disabling it.  */
 913
 914 DEFPARAM (PARAM_USE_CANONICAL_TYPES,
 915           "use-canonical-types",
 916           "Whether to use canonical types.",
 917           1, 0, 1)
 918
 919 DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH,
 920           "max-partial-antic-length",
 921           "Maximum length of partial antic set when performing tree pre optimization.",
 922           100, 0, 0)
 923
 924 /* The following is used as a stop-gap limit for cases where really deep
 925    loop nests cause compile-time to blow up.  If we hit this limit,
 926    FRE and PRE will value-number outer loops (but the outermost) in a
 927    loop nest non-optimistically.  */
 928
 929 DEFPARAM (PARAM_RPO_VN_MAX_LOOP_DEPTH,
 930           "rpo-vn-max-loop-depth",
 931           "Maximum depth of a loop nest to fully value-number optimistically.",
 932           7, 2, 0)
 933
 934 /* The following is used as a stop-gap limit for cases where really huge
 935    functions blow up compile-time use too much.  It limits the number of
 936    alias-queries we do for finding common subexpressions for memory loads and
 937    stores.  The number of alias-queries is otherwise limited by the number of
 938    stores on paths to function entry.  */
 939
 940 DEFPARAM (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS,
 941           "sccvn-max-alias-queries-per-access",
 942           "Maximum number of disambiguations to perform per memory access.",
 943           1000, 0, 0)
 944
 945 DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM,
 946           "ira-max-loops-num",
 947           "Max loops number for regional RA.",
 948           100, 0, 0)
 949
 950 DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE,
 951           "ira-max-conflict-table-size",
 952           "Max size of conflict table in MB.",
 953           1000, 0, 0)
 954
 955 DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS,
 956           "ira-loop-reserved-regs",
 957           "The number of registers in each class kept unused by loop invariant motion.",
 958           2, 0, 0)
 959
 960 DEFPARAM (PARAM_LRA_MAX_CONSIDERED_RELOAD_PSEUDOS,
 961           "lra-max-considered-reload-pseudos",
 962           "The max number of reload pseudos which are considered during spilling a non-reload pseudo.",
 963           500, 0, 0)
 964
 965 DEFPARAM (PARAM_LRA_INHERITANCE_EBB_PROBABILITY_CUTOFF,
 966           "lra-inheritance-ebb-probability-cutoff",
 967           "Minimal fall-through edge probability in percentage used to add BB to inheritance EBB in LRA.",
 968           40, 0, 100)
 969
 970 /* Switch initialization conversion will refuse to create arrays that are
 971    bigger than this parameter times the number of switch branches.  */
 972
 973 DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO,
 974           "switch-conversion-max-branch-ratio",
 975           "The maximum ratio between array size and switch branches for "
 976           "a switch conversion to take place.",
 977           8, 1, 0)
 978
 979 /* Size of tiles when doing loop blocking.  */
 980
 981 DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE,
 982           "loop-block-tile-size",
 983           "Size of tiles for loop blocking.",
 984           51, 0, 0)
 985
 986 /* Maximal number of parameters that we allow in a SCoP.  */
 987
 988 DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS,
 989           "graphite-max-nb-scop-params",
 990           "Maximum number of parameters in a SCoP.",
 991           10, 0, 0)
 992
 993 /* Maximal number of array references in a scop.  */
 994
 995 DEFPARAM (PARAM_GRAPHITE_MAX_ARRAYS_PER_SCOP,
 996           "graphite-max-arrays-per-scop",
 997           "Maximum number of arrays per SCoP.",
 998           100, 0, 0)
 999
1000 DEFPARAM (PARAM_MAX_ISL_OPERATIONS,
1001           "max-isl-operations",
1002           "Maximum number of isl operations, 0 means unlimited.",
1003           350000, 0, 0)
1004
1005 /* For testsuite purposes allow to check for codegen error handling.  */
1006 DEFPARAM (PARAM_GRAPHITE_ALLOW_CODEGEN_ERRORS,
1007           "graphite-allow-codegen-errors",
1008           "Whether codegen errors should be ICEs when -fchecking.",
1009           0, 0, 1)
1010
1011 /* Avoid data dependence analysis on very large loops.  */
1012 DEFPARAM (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS,
1013           "loop-max-datarefs-for-datadeps",
1014           "Maximum number of datarefs in loop for building loop data dependencies.",
1015           1000, 0, 0)
1016
1017 /* Avoid doing loop invariant motion on very large loops.  */
1018
1019 DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP,
1020           "loop-invariant-max-bbs-in-loop",
1021           "Max basic blocks number in loop for loop invariant motion.",
1022           10000, 0, 0)
1023
1024 /* When the parameter is 1, use the internal function id
1025    to look up for profile data. Otherwise, use a more stable
1026    external id based on assembler name and source location. */
1027 DEFPARAM (PARAM_PROFILE_FUNC_INTERNAL_ID,
1028           "profile-func-internal-id",
1029           "Use internal function id in profile lookup.",
1030           0, 0, 1)
1031
1032 /* Avoid SLP vectorization of large basic blocks.  */
1033 DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB,
1034           "slp-max-insns-in-bb",
1035           "Maximum number of instructions in basic block to be considered for "
1036           "SLP vectorization.", 1000, 0, 0)
1037
1038 DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO,
1039           "min-insn-to-prefetch-ratio",
1040           "Min. ratio of insns to prefetches to enable prefetching for "
1041           "a loop with an unknown trip count.",
1042           9, 0, 0)
1043
1044 DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO,
1045           "prefetch-min-insn-to-mem-ratio",
1046           "Min. ratio of insns to mem ops to enable prefetching in a loop.",
1047           3, 0, 0)
1048
1049 /* Set maximum hash table size for var tracking.  */
1050
1051 DEFPARAM (PARAM_MAX_VARTRACK_SIZE,
1052           "max-vartrack-size",
1053           "Max. size of var tracking hash tables.",
1054           50000000, 0, 0)
1055
1056 /* Set maximum recursion depth for var tracking expression expansion
1057    and resolution.  */
1058
1059 DEFPARAM (PARAM_MAX_VARTRACK_EXPR_DEPTH,
1060           "max-vartrack-expr-depth",
1061           "Max. recursion depth for expanding var tracking expressions.",
1062           12, 0, 0)
1063
1064 /* Set maximum length of value location list for which var tracking
1065    should add reverse operations.  */
1066
1067 DEFPARAM (PARAM_MAX_VARTRACK_REVERSE_OP_SIZE,
1068           "max-vartrack-reverse-op-size",
1069           "Max. size of loc list for which reverse ops should be added.",
1070           50, 0, 0)
1071
1072 /* Set a threshold to discard debug markers (e.g. debug begin stmt
1073    markers) when expanding a function to RTL, or inlining it into
1074    another function.  */
1075
1076 DEFPARAM (PARAM_MAX_DEBUG_MARKER_COUNT,
1077           "max-debug-marker-count",
1078           "Max. count of debug markers to expand or inline.",
1079           100000, 0, 0)
1080
1081 /* Set minimum insn uid for non-debug insns.  */
1082
1083 DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID,
1084           "min-nondebug-insn-uid",
1085           "The minimum UID to be used for a nondebug insn.",
1086           0, 0, 0)
1087
1088 DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR,
1089           "ipa-sra-ptr-growth-factor",
1090           "Maximum allowed growth of number and total size of new parameters "
1091           "that ipa-sra replaces a pointer to an aggregate with.",
1092           2, 0, 0)
1093
1094 DEFPARAM (PARAM_IPA_SRA_MAX_REPLACEMENTS,
1095           "ipa-sra-max-replacements",
1096           "Maximum pieces that IPA-SRA tracks per formal parameter, as "
1097           "a consequence, also the maximum number of replacements of a formal "
1098           "parameter.",
1099           8, 0, 16)
1100
1101 DEFPARAM (PARAM_TM_MAX_AGGREGATE_SIZE,
1102           "tm-max-aggregate-size",
1103           "Size in bytes after which thread-local aggregates should be "
1104           "instrumented with the logging functions instead of save/restore "
1105           "pairs.",
1106           9, 0, 0)
1107
1108 DEFPARAM (PARAM_SRA_MAX_SCALARIZATION_SIZE_SPEED,
1109           "sra-max-scalarization-size-Ospeed",
1110           "Maximum size, in storage units, of an aggregate which should be "
1111           "considered for scalarization when compiling for speed.",
1112           0, 0, 0)
1113
1114 DEFPARAM (PARAM_SRA_MAX_SCALARIZATION_SIZE_SIZE,
1115           "sra-max-scalarization-size-Osize",
1116           "Maximum size, in storage units, of an aggregate which should be "
1117           "considered for scalarization when compiling for size.",
1118           0, 0, 0)
1119
1120 DEFPARAM (PARAM_IPA_CP_VALUE_LIST_SIZE,
1121           "ipa-cp-value-list-size",
1122           "Maximum size of a list of values associated with each parameter for "
1123           "interprocedural constant propagation.",
1124           8, 0, 0)
1125
1126 DEFPARAM (PARAM_IPA_CP_EVAL_THRESHOLD,
1127           "ipa-cp-eval-threshold",
1128           "Threshold ipa-cp opportunity evaluation that is still considered "
1129           "beneficial to clone.",
1130           500, 0, 0)
1131
1132 DEFPARAM (PARAM_IPA_CP_RECURSION_PENALTY,
1133           "ipa-cp-recursion-penalty",
1134           "Percentage penalty the recursive functions will receive when they "
1135           "are evaluated for cloning.",
1136           40, 0, 100)
1137
1138 DEFPARAM (PARAM_IPA_CP_SINGLE_CALL_PENALTY,
1139           "ipa-cp-single-call-penalty",
1140           "Percentage penalty functions containing a single call to another "
1141           "function will receive when they are evaluated for cloning.",
1142           15, 0, 100)
1143
1144 DEFPARAM (PARAM_IPA_MAX_AGG_ITEMS,
1145           "ipa-max-agg-items",
1146           "Maximum number of aggregate content items for a parameter in "
1147           "jump functions and lattices.",
1148           16, 0, 0)
1149
1150 DEFPARAM (PARAM_IPA_CP_LOOP_HINT_BONUS,
1151           "ipa-cp-loop-hint-bonus",
1152           "Compile-time bonus IPA-CP assigns to candidates which make loop "
1153           "bounds or strides known.",
1154           64, 0, 0)
1155
1156 DEFPARAM (PARAM_IPA_MAX_AA_STEPS,
1157           "ipa-max-aa-steps",
1158           "Maximum number of statements that will be visited by IPA formal "
1159           "parameter analysis based on alias analysis in any given function.",
1160           25000, 0, 0)
1161
1162 DEFPARAM (PARAM_IPA_MAX_SWITCH_PREDICATE_BOUNDS,
1163           "ipa-max-switch-predicate-bounds",
1164           "Maximal number of boundary endpoints of case ranges of switch "
1165           "statement used during IPA functoin summary generation.",
1166           5, 0, 0)
1167
1168 DEFPARAM (PARAM_IPA_MAX_PARAM_EXPR_OPS,
1169           "ipa-max-param-expr-ops",
1170           "Maximum number of operations in a parameter expression that can "
1171           "be handled by IPA analysis.",
1172           10, 0, 0)
1173
1174 /* WHOPR partitioning configuration.  */
1175
1176 DEFPARAM (PARAM_LTO_PARTITIONS,
1177           "lto-partitions",
1178           "Number of partitions the program should be split to.",
1179           128, 1, 0)
1180
1181 DEFPARAM (MIN_PARTITION_SIZE,
1182           "lto-min-partition",
1183           "Minimal size of a partition for LTO (in estimated instructions).",
1184           10000, 0, 0)
1185
1186 DEFPARAM (MAX_PARTITION_SIZE,
1187           "lto-max-partition",
1188           "Maximal size of a partition for LTO (in estimated instructions).",
1189           1000000, 0, INT_MAX)
1190
1191 DEFPARAM (PARAM_MAX_LTO_STREAMING_PARALLELISM,
1192           "lto-max-streaming-parallelism",
1193           "maximal number of LTO partitions streamed in parallel.",
1194           32, 1, 0)
1195
1196 /* Diagnostic parameters.  */
1197
1198 DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP,
1199           "cxx-max-namespaces-for-diagnostic-help",
1200           "Maximum number of namespaces to search for alternatives when "
1201           "name lookup fails.",
1202           1000, 0, 0)
1203
1204 /* Maximum number of conditional store pairs that can be sunk.  */
1205 DEFPARAM (PARAM_MAX_STORES_TO_SINK,
1206           "max-stores-to-sink",
1207           "Maximum number of conditional store pairs that can be sunk.",
1208           2, 0, 0)
1209
1210 /* Override CASE_VALUES_THRESHOLD of when to switch from doing switch
1211    statements via if statements to using a table jump operation.  If the value
1212    is 0, the default CASE_VALUES_THRESHOLD will be used.  */
1213 DEFPARAM (PARAM_CASE_VALUES_THRESHOLD,
1214           "case-values-threshold",
1215           "The smallest number of different values for which it is best to "
1216           "use a jump-table instead of a tree of conditional branches, "
1217           "if 0, use the default for the machine.",
1218           0, 0, 0)
1219
1220 DEFPARAM (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SIZE,
1221           "jump-table-max-growth-ratio-for-size",
1222           "The maximum code size growth ratio when expanding "
1223           "into a jump table (in percent).  The parameter is used when "
1224           "optimizing for size.",
1225           300, 0, 0)
1226
1227 DEFPARAM (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SPEED,
1228           "jump-table-max-growth-ratio-for-speed",
1229           "The maximum code size growth ratio when expanding "
1230           "into a jump table (in percent).  The parameter is used when "
1231           "optimizing for speed.",
1232           800, 0, 0)
1233
1234 /* Reassociation width to be used by tree reassoc optimization.  */
1235 DEFPARAM (PARAM_TREE_REASSOC_WIDTH,
1236           "tree-reassoc-width",
1237           "Set the maximum number of instructions executed in parallel in "
1238           "reassociated tree.  If 0, use the target dependent heuristic.",
1239           0, 0, 0)
1240
1241 DEFPARAM (PARAM_MAX_TAIL_MERGE_COMPARISONS,
1242           "max-tail-merge-comparisons",
1243           "Maximum amount of similar bbs to compare a bb with.",
1244           10, 0, 0)
1245
1246 DEFPARAM (PARAM_STORE_MERGING_ALLOW_UNALIGNED,
1247           "store-merging-allow-unaligned",
1248           "Allow the store merging pass to introduce unaligned stores "
1249           "if it is legal to do so.",
1250           1, 0, 1)
1251
1252 DEFPARAM (PARAM_MAX_STORES_TO_MERGE,
1253           "max-stores-to-merge",
1254           "Maximum number of constant stores to merge in the "
1255           "store merging pass.",
1256           64, 2, 0)
1257
1258 DEFPARAM (PARAM_STORE_MERGING_MAX_SIZE,
1259           "store-merging-max-size",
1260           "Maximum size of a single store merging region in bytes.",
1261           65536, 1, 1)
1262
1263 DEFPARAM (PARAM_MAX_TAIL_MERGE_ITERATIONS,
1264           "max-tail-merge-iterations",
1265           "Maximum amount of iterations of the pass over a function.",
1266           2, 0, 0)
1267
1268 /* Maximum number of strings for which strlen optimization pass will
1269    track string lenths.  */
1270 DEFPARAM (PARAM_MAX_TRACKED_STRLENS,
1271           "max-tracked-strlens",
1272           "Maximum number of strings for which strlen optimization pass will "
1273           "track string lengths.",
1274           10000, 0, 0)
1275
1276 /* Keep this in sync with the sched_pressure_algorithm enum.  */
1277 DEFPARAM (PARAM_SCHED_PRESSURE_ALGORITHM,
1278           "sched-pressure-algorithm",
1279           "Which -fsched-pressure algorithm to apply.",
1280           1, 1, 2)
1281
1282 /* Maximum length of candidate scans in straight-line strength reduction.  */
1283 DEFPARAM (PARAM_MAX_SLSR_CANDIDATE_SCAN,
1284           "max-slsr-cand-scan",
1285           "Maximum length of candidate scans for straight-line "
1286           "strength reduction.",
1287           50, 1, 999999)
1288
1289 /* ASan stands for AddressSanitizer: https://github.com/google/sanitizers.  */
1290
1291 DEFPARAM (PARAM_ASAN_STACK,
1292          "asan-stack",
1293          "Enable asan stack protection.",
1294          1, 0, 1)
1295
1296 DEFPARAM (PARAM_ASAN_PROTECT_ALLOCAS,
1297         "asan-instrument-allocas",
1298         "Enable asan allocas/VLAs protection.",
1299         1, 0, 1)
1300
1301 DEFPARAM (PARAM_ASAN_GLOBALS,
1302          "asan-globals",
1303          "Enable asan globals protection.",
1304          1, 0, 1)
1305
1306 DEFPARAM (PARAM_ASAN_INSTRUMENT_WRITES,
1307          "asan-instrument-writes",
1308          "Enable asan store operations protection.",
1309          1, 0, 1)
1310
1311 DEFPARAM (PARAM_ASAN_INSTRUMENT_READS,
1312          "asan-instrument-reads",
1313          "Enable asan load operations protection.",
1314          1, 0, 1)
1315
1316 DEFPARAM (PARAM_ASAN_MEMINTRIN,
1317          "asan-memintrin",
1318          "Enable asan builtin functions protection.",
1319          1, 0, 1)
1320
1321 DEFPARAM (PARAM_ASAN_USE_AFTER_RETURN,
1322          "asan-use-after-return",
1323          "Enable asan detection of use-after-return bugs.",
1324          1, 0, 1)
1325
1326 DEFPARAM (PARAM_ASAN_INSTRUMENTATION_WITH_CALL_THRESHOLD,
1327          "asan-instrumentation-with-call-threshold",
1328          "Use callbacks instead of inline code if number of accesses "
1329          "in function becomes greater or equal to this number.",
1330          7000, 0, INT_MAX)
1331
1332 DEFPARAM (PARAM_USE_AFTER_SCOPE_DIRECT_EMISSION_THRESHOLD,
1333          "use-after-scope-direct-emission-threshold",
1334          "Use direct poisoning/unpoisoning instructions for variables "
1335          "smaller or equal to this number.",
1336          256, 0, INT_MAX)
1337
1338 DEFPARAM (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS,
1339           "uninit-control-dep-attempts",
1340           "Maximum number of nested calls to search for control dependencies "
1341           "during uninitialized variable analysis.",
1342           1000, 1, 0)
1343
1344 DEFPARAM (PARAM_FSM_SCALE_PATH_STMTS,
1345           "fsm-scale-path-stmts",
1346           "Scale factor to apply to the number of statements in a threading path when comparing to the number of (scaled) blocks.",
1347           2, 1, 10)
1348
1349 DEFPARAM (PARAM_FSM_MAXIMUM_PHI_ARGUMENTS,
1350           "fsm-maximum-phi-arguments",
1351           "Maximum number of arguments a PHI may have before the FSM threader will not try to thread through its block.",
1352           100, 1, 999999)
1353
1354 DEFPARAM (PARAM_FSM_SCALE_PATH_BLOCKS,
1355           "fsm-scale-path-blocks",
1356           "Scale factor to apply to the number of blocks in a threading path when comparing to the number of (scaled) statements.",
1357           3, 1, 10)
1358
1359 DEFPARAM (PARAM_MAX_FSM_THREAD_PATH_INSNS,
1360           "max-fsm-thread-path-insns",
1361           "Maximum number of instructions to copy when duplicating blocks on a finite state automaton jump thread path.",
1362           100, 1, 999999)
1363
1364 DEFPARAM (PARAM_MAX_FSM_THREAD_LENGTH,
1365           "max-fsm-thread-length",
1366           "Maximum number of basic blocks on a finite state automaton jump thread path.",
1367           10, 1, 999999)
1368
1369 DEFPARAM (PARAM_MAX_FSM_THREAD_PATHS,
1370           "max-fsm-thread-paths",
1371           "Maximum number of new jump thread paths to create for a finite state automaton.",
1372           50, 1, 999999)
1373
1374 DEFPARAM (PARAM_PARLOOPS_CHUNK_SIZE,
1375           "parloops-chunk-size",
1376           "Chunk size of omp schedule for loops parallelized by parloops.",
1377           0, 0, 0)
1378
1379 DEFPARAMENUM5 (PARAM_PARLOOPS_SCHEDULE,
1380                "parloops-schedule",
1381                "Schedule type of omp schedule for loops parallelized by "
1382                "parloops (static, dynamic, guided, auto, runtime).",
1383                static,
1384                static, dynamic, guided, auto, runtime)
1385
1386 DEFPARAM (PARAM_PARLOOPS_MIN_PER_THREAD,
1387           "parloops-min-per-thread",
1388           "Minimum number of iterations per thread of an innermost "
1389           "parallelized loop.",
1390           100, 2, 0)
1391
1392 DEFPARAM (PARAM_MAX_SSA_NAME_QUERY_DEPTH,
1393           "max-ssa-name-query-depth",
1394           "Maximum recursion depth allowed when querying a property of an"
1395           " SSA name.",
1396           3, 1, 10)
1397
1398 DEFPARAM (PARAM_MAX_RTL_IF_CONVERSION_INSNS,
1399           "max-rtl-if-conversion-insns",
1400           "Maximum number of insns in a basic block to consider for RTL "
1401           "if-conversion.",
1402           10, 0, 99)
1403
1404 DEFPARAM (PARAM_MAX_RTL_IF_CONVERSION_PREDICTABLE_COST,
1405           "max-rtl-if-conversion-predictable-cost",
1406           "Maximum permissible cost for the sequence that would be "
1407           "generated by the RTL if-conversion pass for a branch that "
1408           "is considered predictable.",
1409           20, 0, 200)
1410
1411 DEFPARAM (PARAM_MAX_RTL_IF_CONVERSION_UNPREDICTABLE_COST,
1412           "max-rtl-if-conversion-unpredictable-cost",
1413           "Maximum permissible cost for the sequence that would be "
1414           "generated by the RTL if-conversion pass for a branch that "
1415           "is considered unpredictable.",
1416           40, 0, 200)
1417
1418 DEFPARAM (PARAM_HSA_GEN_DEBUG_STORES,
1419           "hsa-gen-debug-stores",
1420           "Level of hsa debug stores verbosity.",
1421           0, 0, 1)
1422
1423 DEFPARAM (PARAM_MAX_SPECULATIVE_DEVIRT_MAYDEFS,
1424           "max-speculative-devirt-maydefs",
1425           "Maximum number of may-defs visited when devirtualizing "
1426           "speculatively.", 50, 0, 0)
1427
1428 DEFPARAM (PARAM_MAX_VRP_SWITCH_ASSERTIONS,
1429           "max-vrp-switch-assertions",
1430           "Maximum number of assertions to add along the default "
1431           "edge of a switch statement during VRP.",
1432           10, 0, 0)
1433
1434 DEFPARAM (PARAM_VECT_EPILOGUES_NOMASK,
1435           "vect-epilogues-nomask",
1436           "Enable loop epilogue vectorization using smaller vector size.",
1437           0, 0, 1)
1438
1439 DEFPARAM(PARAM_UNROLL_JAM_MIN_PERCENT,
1440          "unroll-jam-min-percent",
1441          "Minimum percentage of memrefs that must go away for unroll-and-jam to be considered profitable.",
1442          1, 0, 100)
1443
1444 DEFPARAM(PARAM_UNROLL_JAM_MAX_UNROLL,
1445          "unroll-jam-max-unroll",
1446          "Maximum unroll factor for the unroll-and-jam transformation.",
1447          4, 0, 0)
1448
1449 DEFPARAM(PARAM_AVOID_FMA_MAX_BITS,
1450          "avoid-fma-max-bits",
1451          "Maximum number of bits for which we avoid creating FMAs.",
1452          0, 0, 512)
1453
1454 DEFPARAM(PARAM_LOGICAL_OP_NON_SHORT_CIRCUIT,
1455          "logical-op-non-short-circuit",
1456          "True if a non-short-circuit operation is optimal.",
1457          -1, -1, 1)
1458
1459 DEFPARAM(PARAM_LOOP_VERSIONING_MAX_INNER_INSNS,
1460          "loop-versioning-max-inner-insns",
1461          "The maximum number of instructions in an inner loop that is being"
1462          " considered for versioning.",
1463          200, 0, 0)
1464
1465 DEFPARAM(PARAM_LOOP_VERSIONING_MAX_OUTER_INSNS,
1466          "loop-versioning-max-outer-insns",
1467          "The maximum number of instructions in an outer loop that is being"
1468          " considered for versioning, on top of the instructions in inner"
1469          " loops.",
1470          100, 0, 0)
1471
1472 DEFPARAM(PARAM_GIMPLE_FE_COMPUTED_HOT_BB_THRESHOLD,
1473          "gimple-fe-computed-hot-bb-threshold",
1474          "The number of executions of a basic block which is considered hot."
1475          " The parameter is used only in GIMPLE FE.",
1476          0, 0, 0)
1477
1478 DEFPARAM(PARAM_HASH_TABLE_VERIFICATION_LIMIT,
1479          "hash-table-verification-limit",
1480          "The number of elements for which hash table verification is done for "
1481          "each searched element.",
1482          10, 0, 0)
1483
1484 DEFPARAM(PARAM_SSA_NAME_DEF_CHAIN_LIMIT,
1485          "ssa-name-def-chain-limit",
1486          "The maximum number of SSA_NAME assignments to follow in determining "
1487          "a value.",
1488          512, 0, 0)
1489
1490 /*
1491
1492 Local variables:
1493 mode:c
1494 End:
1495 */