190075Sobrien/* params.def - Run-time parameters. 2169689Skan Copyright (C) 2001, 2002, 2004, 2005 Free Software Foundation, Inc. 390075Sobrien Written by Mark Mitchell <mark@codesourcery.com>. 490075Sobrien 590075SobrienThis file is part of GCC. 690075Sobrien 790075SobrienGCC is free software; you can redistribute it and/or modify it under 890075Sobrienthe terms of the GNU General Public License as published by the Free 990075SobrienSoftware Foundation; either version 2, or (at your option) any later 1090075Sobrienversion. 1190075Sobrien 1290075SobrienGCC is distributed in the hope that it will be useful, but WITHOUT ANY 1390075SobrienWARRANTY; without even the implied warranty of MERCHANTABILITY or 1490075SobrienFITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1590075Sobrienfor more details. 1690075Sobrien 1790075SobrienYou should have received a copy of the GNU General Public License 1890075Sobrienalong with GCC; see the file COPYING. If not, write to the Free 19169689SkanSoftware Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 20169689Skan02110-1301, USA. 2190075Sobrien 2290075Sobrien*/ 2390075Sobrien 2490075Sobrien/* This file contains definitions for language-independent 25169689Skan parameters. The DEFPARAM macro takes 6 arguments: 2690075Sobrien 2790075Sobrien - The enumeral corresponding to this parameter. 2890075Sobrien 2990075Sobrien - The name that can be used to set this parameter using the 3090075Sobrien command-line option `--param <name>=<value>'. 3190075Sobrien 3290075Sobrien - A help string explaining how the parameter is used. 3390075Sobrien 3490075Sobrien - A default value for the parameter. 3590075Sobrien 36169689Skan - The minimum acceptable value for the parameter. 37169689Skan 38169689Skan - The maximum acceptable value for the parameter (if greater than 39169689Skan the minimum). 40169689Skan 4190075Sobrien Be sure to add an entry to invoke.texi summarizing the parameter. */ 4290075Sobrien 43169689Skan/* The maximum number of fields in a variable with only implicit uses 44169689Skan for which structure aliasing will consider trying to track each 45169689Skan field. The default is 5. */ 46169689SkanDEFPARAM (PARAM_SALIAS_MAX_IMPLICIT_FIELDS, 47169689Skan "salias-max-implicit-fields", 48169689Skan "The maximum number of fields in a structure variable without direct structure accesses that GCC will attempt to track separately", 49169689Skan 5, 0, 0) 50169689Skan 51169689Skan/* The maximum number of array elements structure aliasing will decompose 52169689Skan an array for. The default is 4. */ 53169689SkanDEFPARAM (PARAM_SALIAS_MAX_ARRAY_ELEMENTS, 54169689Skan "salias-max-array-elements", 55169689Skan "The maximum number of elements in an array for wich we track its elements separately", 56169689Skan 4, 0, 0) 57169689Skan 58169689Skan/* The maximum structure size at which the scalar replacement of 59169689Skan aggregates (SRA) pass will perform block copies. The default 60169689Skan value, 0, implies that GCC will select the most appropriate size 61169689Skan itself. */ 62169689SkanDEFPARAM (PARAM_SRA_MAX_STRUCTURE_SIZE, 63169689Skan "sra-max-structure-size", 64169689Skan "The maximum structure size (in bytes) for which GCC will " 65169689Skan "use by-element copies", 66169689Skan 0, 0, 0) 67169689Skan 68169689Skan/* The maximum number of structure fields which the SRA pass will 69169689Skan instantiate to avoid block copies. The default value, 0, implies 70169689Skan that GCC will select the appropriate value itself. */ 71169689SkanDEFPARAM (PARAM_SRA_MAX_STRUCTURE_COUNT, 72169689Skan "sra-max-structure-count", 73169689Skan "The maximum number of structure fields for which GCC will " 74169689Skan "use by-element copies", 75169689Skan 0, 0, 0) 76169689Skan 77169689Skan/* The ratio between instantiated fields and the complete structure 78169689Skan size. We say that if the ratio of the number of bytes in 79169689Skan instantiated fields to the number of bytes in the complete 80169689Skan structure exceeds this parameter, or if the number of instantiated 81169689Skan fields to the total number of fields exceeds this parameter, then 82169689Skan block copies are not used. The default is 75%. */ 83169689SkanDEFPARAM (PARAM_SRA_FIELD_STRUCTURE_RATIO, 84169689Skan "sra-field-structure-ratio", 85169689Skan "The threshold ratio between instantiated fields and the total structure size", 86169689Skan 75, 0, 100) 87169689Skan 88117395Skan/* The single function inlining limit. This is the maximum size 89117395Skan of a function counted in internal gcc instructions (not in 90117395Skan real machine instructions) that is eligible for inlining 91117395Skan by the tree inliner. 92169689Skan The default value is 450. 93117395Skan Only functions marked inline (or methods defined in the class 94169689Skan definition for C++) are affected by this. 95117395Skan There are more restrictions to inlining: If inlined functions 96117395Skan call other functions, the already inlined instructions are 97117395Skan counted and once the recursive inline limit (see 98117395Skan "max-inline-insns" parameter) is exceeded, the acceptable size 99117395Skan gets decreased. */ 100117395SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE, 101117395Skan "max-inline-insns-single", 102117395Skan "The maximum number of instructions in a single function eligible for inlining", 103169689Skan 450, 0, 0) 104117395Skan 105117395Skan/* The single function inlining limit for functions that are 106117395Skan inlined by virtue of -finline-functions (-O3). 107117395Skan This limit should be chosen to be below or equal to the limit 108117395Skan that is applied to functions marked inlined (or defined in the 109117395Skan class declaration in C++) given by the "max-inline-insns-single" 110117395Skan parameter. 111169689Skan The default value is 90. */ 112117395SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO, 113117395Skan "max-inline-insns-auto", 114117395Skan "The maximum number of instructions when automatically inlining", 115169689Skan 90, 0, 0) 116117395Skan 117169689SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE, 118169689Skan "max-inline-insns-recursive", 119169689Skan "The maximum number of instructions inline function can grow to via recursive inlining", 120169689Skan 450, 0, 0) 121117395Skan 122169689SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO, 123169689Skan "max-inline-insns-recursive-auto", 124169689Skan "The maximum number of instructions non-inline function can grow to via recursive inlining", 125169689Skan 450, 0, 0) 126169689Skan 127169689SkanDEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH, 128169689Skan "max-inline-recursive-depth", 129169689Skan "The maximum depth of recursive inlining for inline functions", 130169689Skan 8, 0, 0) 131169689Skan 132169689SkanDEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO, 133169689Skan "max-inline-recursive-depth-auto", 134169689Skan "The maximum depth of recursive inlining for non-inline functions", 135169689Skan 8, 0, 0) 136169689Skan 137169689SkanDEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY, 138169689Skan "min-inline-recursive-probability", 139169689Skan "Inline recursively only when the probability of call being executed exceeds the parameter", 140169689Skan 10, 0, 0) 141169689Skan 142169689Skan/* Limit the number of expansions created by the variable expansion 143169689Skan optimization to avoid register pressure. */ 144169689SkanDEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS, 145169689Skan "max-variable-expansions-in-unroller", 146169689Skan "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling", 147169689Skan 1, 0, 0) 148169689Skan 14990075Sobrien/* The maximum number of instructions to consider when looking for an 15090075Sobrien instruction to fill a delay slot. If more than this arbitrary 15190075Sobrien number of instructions is searched, the time savings from filling 15290075Sobrien the delay slot will be minimal so stop searching. Increasing 15390075Sobrien values mean more aggressive optimization, making the compile time 15490075Sobrien increase with probably small improvement in executable run time. */ 15590075SobrienDEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH, 15690075Sobrien "max-delay-slot-insn-search", 15790075Sobrien "The maximum number of instructions to consider to fill a delay slot", 158169689Skan 100, 0, 0) 15990075Sobrien 16090075Sobrien/* When trying to fill delay slots, the maximum number of instructions 16190075Sobrien to consider when searching for a block with valid live register 16290075Sobrien information. Increasing this arbitrarily chosen value means more 16390075Sobrien aggressive optimization, increasing the compile time. This 16490075Sobrien parameter should be removed when the delay slot code is rewritten 16590075Sobrien to maintain the control-flow graph. */ 16690075SobrienDEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH, 16790075Sobrien "max-delay-slot-live-search", 16890075Sobrien "The maximum number of instructions to consider to find accurate live register information", 169169689Skan 333, 0, 0) 17090075Sobrien 17190075Sobrien/* This parameter limits the number of branch elements that the 17290075Sobrien scheduler will track anti-dependencies through without resetting 17390075Sobrien the tracking mechanism. Large functions with few calls or barriers 17490075Sobrien can generate lists containing many 1000's of dependencies. Generally 17590075Sobrien the compiler either uses all available memory, or runs for far too long. */ 17690075SobrienDEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH, 17790075Sobrien "max-pending-list-length", 17890075Sobrien "The maximum length of scheduling's pending operations list", 179169689Skan 32, 0, 0) 18090075Sobrien 181132718SkanDEFPARAM(PARAM_LARGE_FUNCTION_INSNS, 182132718Skan "large-function-insns", 183132718Skan "The size of function body to be considered large", 184169689Skan 2700, 0, 0) 185132718SkanDEFPARAM(PARAM_LARGE_FUNCTION_GROWTH, 186132718Skan "large-function-growth", 187132718Skan "Maximal growth due to inlining of large function (in percent)", 188169689Skan 100, 0, 0) 189169689SkanDEFPARAM(PARAM_LARGE_UNIT_INSNS, 190169689Skan "large-unit-insns", 191169689Skan "The size of translation unit to be considered large", 192169689Skan 10000, 0, 0) 193132718SkanDEFPARAM(PARAM_INLINE_UNIT_GROWTH, 194132718Skan "inline-unit-growth", 195132718Skan "how much can given compilation unit grow because of the inlining (in percent)", 196169689Skan 50, 0, 0) 197169689SkanDEFPARAM(PARAM_INLINE_CALL_COST, 198169689Skan "inline-call-cost", 199169689Skan "expense of call operation relative to ordinary arithmetic operations", 200169689Skan 16, 0, 0) 201132718Skan 20290075Sobrien/* The GCSE optimization will be disabled if it would require 20390075Sobrien significantly more memory than this value. */ 20490075SobrienDEFPARAM(PARAM_MAX_GCSE_MEMORY, 20590075Sobrien "max-gcse-memory", 20690075Sobrien "The maximum amount of memory to be allocated by GCSE", 207169689Skan 50 * 1024 * 1024, 0, 0) 208117395Skan/* The number of repetitions of copy/const prop and PRE to run. */ 20990075SobrienDEFPARAM(PARAM_MAX_GCSE_PASSES, 21090075Sobrien "max-gcse-passes", 21190075Sobrien "The maximum number of passes to make when doing GCSE", 212169689Skan 1, 1, 0) 213169689Skan/* This is the threshold ratio when to perform partial redundancy 214169689Skan elimination after reload. We perform partial redundancy elimination 215169689Skan when the following holds: 216169689Skan (Redundant load execution count) 217169689Skan ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION 218169689Skan (Added loads execution count) */ 219169689SkanDEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION, 220169689Skan "gcse-after-reload-partial-fraction", 221169689Skan "The threshold ratio for performing partial redundancy elimination after reload", 222169689Skan 3, 0, 0) 223169689Skan/* This is the threshold ratio of the critical edges execution count compared to 224169689Skan the redundant loads execution count that permits performing the load 225169689Skan redundancy elimination in gcse after reload. */ 226169689SkanDEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION, 227169689Skan "gcse-after-reload-critical-fraction", 228169689Skan "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload", 229169689Skan 10, 0, 0) 230117395Skan/* This parameter limits the number of insns in a loop that will be unrolled, 231132718Skan and by how much the loop is unrolled. 232132718Skan 233132718Skan This limit should be at most half of the peeling limits: loop unroller 234132718Skan decides to not unroll loops that iterate fewer than 2*number of allowed 235169689Skan unrollings and thus we would have loops that are neither peeled or unrolled 236132718Skan otherwise. */ 237117395SkanDEFPARAM(PARAM_MAX_UNROLLED_INSNS, 238117395Skan "max-unrolled-insns", 239117395Skan "The maximum number of instructions to consider to unroll in a loop", 240169689Skan 200, 0, 0) 241132718Skan/* This parameter limits how many times the loop is unrolled depending 242132718Skan on number of insns really executed in each iteration. */ 243132718SkanDEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS, 244132718Skan "max-average-unrolled-insns", 245132718Skan "The maximum number of instructions to consider to unroll in a loop on average", 246169689Skan 80, 0, 0) 247132718Skan/* The maximum number of unrollings of a single loop. */ 248132718SkanDEFPARAM(PARAM_MAX_UNROLL_TIMES, 249132718Skan "max-unroll-times", 250132718Skan "The maximum number of unrollings of a single loop", 251169689Skan 8, 0, 0) 252132718Skan/* The maximum number of insns of a peeled loop. */ 253132718SkanDEFPARAM(PARAM_MAX_PEELED_INSNS, 254132718Skan "max-peeled-insns", 255132718Skan "The maximum number of insns of a peeled loop", 256169689Skan 400, 0, 0) 257132718Skan/* The maximum number of peelings of a single loop. */ 258132718SkanDEFPARAM(PARAM_MAX_PEEL_TIMES, 259132718Skan "max-peel-times", 260132718Skan "The maximum number of peelings of a single loop", 261169689Skan 16, 0, 0) 262132718Skan/* The maximum number of insns of a peeled loop. */ 263132718SkanDEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS, 264132718Skan "max-completely-peeled-insns", 265132718Skan "The maximum number of insns of a completely peeled loop", 266169689Skan 400, 0, 0) 267132718Skan/* The maximum number of peelings of a single loop that is peeled completely. */ 268132718SkanDEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES, 269132718Skan "max-completely-peel-times", 270132718Skan "The maximum number of peelings of a single loop that is peeled completely", 271169689Skan 16, 0, 0) 272132718Skan/* The maximum number of insns of a peeled loop that rolls only once. */ 273132718SkanDEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS, 274132718Skan "max-once-peeled-insns", 275132718Skan "The maximum number of insns of a peeled loop that rolls only once", 276169689Skan 400, 0, 0) 277117395Skan 278132718Skan/* The maximum number of insns of an unswitched loop. */ 279132718SkanDEFPARAM(PARAM_MAX_UNSWITCH_INSNS, 280132718Skan "max-unswitch-insns", 281132718Skan "The maximum number of insns of an unswitched loop", 282169689Skan 50, 0, 0) 283132718Skan/* The maximum level of recursion in unswitch_single_loop. */ 284132718SkanDEFPARAM(PARAM_MAX_UNSWITCH_LEVEL, 285132718Skan "max-unswitch-level", 286132718Skan "The maximum number of unswitchings in a single loop", 287169689Skan 3, 0, 0) 288132718Skan 289169689Skan/* The maximum number of iterations of a loop the brute force algorithm 290169689Skan for analysis of # of iterations of the loop tries to evaluate. */ 291169689SkanDEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK, 292169689Skan "max-iterations-to-track", 293169689Skan "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates", 294169689Skan 1000, 0, 0) 295169689Skan/* A cutoff to avoid costly computations of the number of iterations in 296169689Skan the doloop transformation. */ 297169689SkanDEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST, 298169689Skan "max-iterations-computation-cost", 299169689Skan "Bound on the cost of an expression to compute the number of iterations", 300169689Skan 10, 0, 0) 301169689Skan 302169689SkanDEFPARAM(PARAM_MAX_SMS_LOOP_NUMBER, 303169689Skan "max-sms-loop-number", 304169689Skan "Maximum number of loops to perform swing modulo scheduling on (mainly for debugging)", 305169689Skan -1, -1, -1) 306169689Skan 307169689Skan/* This parameter is used to tune SMS MAX II calculations. */ 308169689SkanDEFPARAM(PARAM_SMS_MAX_II_FACTOR, 309169689Skan "sms-max-ii-factor", 310169689Skan "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop", 311169689Skan 100, 0, 0) 312169689SkanDEFPARAM(PARAM_SMS_DFA_HISTORY, 313169689Skan "sms-dfa-history", 314169689Skan "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA", 315169689Skan 0, 0, 0) 316169689SkanDEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD, 317169689Skan "sms-loop-average-count-threshold", 318169689Skan "A threshold on the average loop count considered by the swing modulo scheduler", 319169689Skan 0, 0, 0) 320169689Skan 321117395SkanDEFPARAM(HOT_BB_COUNT_FRACTION, 322117395Skan "hot-bb-count-fraction", 323169689Skan "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot", 324169689Skan 10000, 0, 0) 325117395SkanDEFPARAM(HOT_BB_FREQUENCY_FRACTION, 326117395Skan "hot-bb-frequency-fraction", 327169689Skan "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot", 328169689Skan 1000, 0, 0) 329169689Skan 330169689Skan/* For guessed profiles, the loops having unknown number of iterations 331169689Skan are predicted to iterate relatively few (10) times at average. 332169689Skan For functions containing one loop with large known number of iterations 333169689Skan and other loops having unbounded loops we would end up predicting all 334169689Skan the other loops cold that is not usually the case. So we need to artificially 335169689Skan flatten the profile. 336169689Skan 337169689Skan We need to cut the maximal predicted iterations to large enough iterations 338169689Skan so the loop appears important, but safely within HOT_BB_COUNT_FRACTION 339169689Skan range. */ 340169689Skan 341169689SkanDEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS, 342169689Skan "max-predicted-iterations", 343169689Skan "The maximum number of loop iterations we predict statically", 344169689Skan 100, 0, 0) 345117395SkanDEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK, 346117395Skan "tracer-dynamic-coverage-feedback", 347169689Skan "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available", 348169689Skan 95, 0, 100) 349117395SkanDEFPARAM(TRACER_DYNAMIC_COVERAGE, 350117395Skan "tracer-dynamic-coverage", 351169689Skan "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available", 352169689Skan 75, 0, 100) 353117395SkanDEFPARAM(TRACER_MAX_CODE_GROWTH, 354117395Skan "tracer-max-code-growth", 355132718Skan "Maximal code growth caused by tail duplication (in percent)", 356169689Skan 100, 0, 0) 357117395SkanDEFPARAM(TRACER_MIN_BRANCH_RATIO, 358117395Skan "tracer-min-branch-ratio", 359169689Skan "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)", 360169689Skan 10, 0, 100) 361117395SkanDEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK, 362117395Skan "tracer-min-branch-probability-feedback", 363169689Skan "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available", 364169689Skan 80, 0, 100) 365117395SkanDEFPARAM(TRACER_MIN_BRANCH_PROBABILITY, 366117395Skan "tracer-min-branch-probability", 367169689Skan "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available", 368169689Skan 50, 0, 100) 369117395Skan 370117395Skan/* The maximum number of incoming edges to consider for crossjumping. */ 371117395SkanDEFPARAM(PARAM_MAX_CROSSJUMP_EDGES, 372117395Skan "max-crossjump-edges", 373117395Skan "The maximum number of incoming edges to consider for crossjumping", 374169689Skan 100, 0, 0) 375117395Skan 376169689Skan/* The minimum number of matching instructions to consider for crossjumping. */ 377169689SkanDEFPARAM(PARAM_MIN_CROSSJUMP_INSNS, 378169689Skan "min-crossjump-insns", 379169689Skan "The minimum number of matching instructions to consider for crossjumping", 380169689Skan 5, 0, 0) 381169689Skan 382169689Skan/* The maximum number expansion factor when copying basic blocks. */ 383169689SkanDEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS, 384169689Skan "max-grow-copy-bb-insns", 385169689Skan "The maximum expansion factor when copying basic blocks", 386169689Skan 8, 0, 0) 387169689Skan 388169689Skan/* The maximum number of insns to duplicate when unfactoring computed gotos. */ 389169689SkanDEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS, 390169689Skan "max-goto-duplication-insns", 391169689Skan "The maximum number of insns to duplicate when unfactoring computed gotos", 392169689Skan 8, 0, 0) 393169689Skan 394132718Skan/* The maximum length of path considered in cse. */ 395132718SkanDEFPARAM(PARAM_MAX_CSE_PATH_LENGTH, 396132718Skan "max-cse-path-length", 397132718Skan "The maximum length of path considered in cse", 398169689Skan 10, 0, 0) 399169689SkanDEFPARAM(PARAM_MAX_CSE_INSNS, 400169689Skan "max-cse-insns", 401169689Skan "The maximum instructions CSE process before flushing", 402169689Skan 1000, 0, 0) 403132718Skan 404169689Skan/* The cost of expression in loop invariant motion that is considered 405169689Skan expensive. */ 406169689SkanDEFPARAM(PARAM_LIM_EXPENSIVE, 407169689Skan "lim-expensive", 408169689Skan "The minimum cost of an expensive expression in the loop invariant motion", 409169689Skan 20, 0, 0) 410169689Skan 411169689Skan/* Bound on number of candidates for induction variables below that 412169689Skan all candidates are considered for each use in induction variable 413169689Skan optimizations. */ 414169689Skan 415169689SkanDEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND, 416169689Skan "iv-consider-all-candidates-bound", 417169689Skan "Bound on number of candidates below that all candidates are considered in iv optimizations", 418169689Skan 30, 0, 0) 419169689Skan 420169689Skan/* The induction variable optimizations give up on loops that contain more 421169689Skan induction variable uses. */ 422169689Skan 423169689SkanDEFPARAM(PARAM_IV_MAX_CONSIDERED_USES, 424169689Skan "iv-max-considered-uses", 425169689Skan "Bound on number of iv uses in loop optimized in iv optimizations", 426169689Skan 250, 0, 0) 427169689Skan 428169689Skan/* If there are at most this number of ivs in the set, try removing unnecessary 429169689Skan ivs from the set always. */ 430169689Skan 431169689SkanDEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND, 432169689Skan "iv-always-prune-cand-set-bound", 433169689Skan "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization", 434169689Skan 10, 0, 0) 435169689Skan 436169689SkanDEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE, 437169689Skan "scev-max-expr-size", 438169689Skan "Bound on size of expressions used in the scalar evolutions analyzer", 439169689Skan 20, 0, 0) 440169689Skan 441169689SkanDEFPARAM(PARAM_VECT_MAX_VERSION_CHECKS, 442169689Skan "vect-max-version-checks", 443169689Skan "Bound on number of runtime checks inserted by the vectorizer's loop versioning", 444169689Skan 6, 0, 0) 445169689Skan 446169689Skan/* The product of the next two is used to decide whether or not to 447169689Skan use .GLOBAL_VAR. See tree-dfa.c. */ 448169689SkanDEFPARAM(PARAM_GLOBAL_VAR_THRESHOLD, 449169689Skan "global-var-threshold", 450169689Skan "Given N calls and V call-clobbered vars in a function. Use .GLOBAL_VAR if NxV is larger than this limit", 451169689Skan 500000, 0, 0) 452169689Skan 453132718SkanDEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS, 454132718Skan "max-cselib-memory-locations", 455132718Skan "The maximum memory locations recorded by cselib", 456169689Skan 500, 0, 0) 457169689SkanDEFPARAM(PARAM_MAX_FLOW_MEMORY_LOCATIONS, 458169689Skan "max-flow-memory-locations", 459169689Skan "The maximum memory locations recorded by flow", 460169689Skan 100, 0, 0) 461132718Skan 462117395Skan#ifdef ENABLE_GC_ALWAYS_COLLECT 463117395Skan# define GGC_MIN_EXPAND_DEFAULT 0 464117395Skan# define GGC_MIN_HEAPSIZE_DEFAULT 0 465117395Skan#else 466117395Skan# define GGC_MIN_EXPAND_DEFAULT 30 467117395Skan# define GGC_MIN_HEAPSIZE_DEFAULT 4096 468117395Skan#endif 469117395Skan 470117395SkanDEFPARAM(GGC_MIN_EXPAND, 471117395Skan "ggc-min-expand", 472169689Skan "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap", 473169689Skan GGC_MIN_EXPAND_DEFAULT, 0, 0) 474117395Skan 475117395SkanDEFPARAM(GGC_MIN_HEAPSIZE, 476117395Skan "ggc-min-heapsize", 477132718Skan "Minimum heap size before we start collecting garbage, in kilobytes", 478169689Skan GGC_MIN_HEAPSIZE_DEFAULT, 0, 0) 479117395Skan 480117395Skan#undef GGC_MIN_EXPAND_DEFAULT 481117395Skan#undef GGC_MIN_HEAPSIZE_DEFAULT 482117395Skan 483132718SkanDEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS, 484132718Skan "max-reload-search-insns", 485132718Skan "The maximum number of instructions to search backward when looking for equivalent reload", 486169689Skan 100, 0, 0) 487132718Skan 488169689SkanDEFPARAM(PARAM_MAX_ALIASED_VOPS, 489169689Skan "max-aliased-vops", 490169689Skan "The maximum number of virtual operands allowed to represent aliases before triggering alias grouping", 491169689Skan 500, 0, 0) 492169689Skan 493169689SkanDEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS, 494169689Skan "max-sched-region-blocks", 495169689Skan "The maximum number of blocks in a region to be considered for interblock scheduling", 496169689Skan 10, 0, 0) 497169689Skan 498169689SkanDEFPARAM(PARAM_MAX_SCHED_REGION_INSNS, 499169689Skan "max-sched-region-insns", 500169689Skan "The maximum number of insns in a region to be considered for interblock scheduling", 501169689Skan 100, 0, 0) 502169689Skan 503169689SkanDEFPARAM(PARAM_MIN_SPEC_PROB, 504169689Skan "min-spec-prob", 505169689Skan "The minimum probability of reaching a source block for interblock speculative scheduling", 506169689Skan 40, 0, 0) 507169689Skan 508169689SkanDEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS, 509169689Skan "max-sched-extend-regions-iters", 510169689Skan "The maximum number of iterations through CFG to extend regions", 511169689Skan 0, 0, 0) 512169689Skan 513169689SkanDEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY, 514169689Skan "max-sched-insn-conflict-delay", 515169689Skan "The maximum conflict delay for an insn to be considered for speculative motion", 516169689Skan 3, 1, 10) 517169689Skan 518169689SkanDEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF, 519169689Skan "sched-spec-prob-cutoff", 520169689Skan "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.", 521169689Skan 40, 0, 100) 522169689Skan 523169689SkanDEFPARAM(PARAM_MAX_LAST_VALUE_RTL, 524169689Skan "max-last-value-rtl", 525169689Skan "The maximum number of RTL nodes that can be recorded as combiner's last value", 526169689Skan 10000, 0, 0) 527169689Skan 528169689Skan/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for 529169689Skan {signed,unsigned} integral types. This determines N. 530169689Skan Experimentation shows 256 to be a good value. */ 531169689SkanDEFPARAM (PARAM_INTEGER_SHARE_LIMIT, 532169689Skan "integer-share-limit", 533169689Skan "The upper bound for sharing integer constants", 534169689Skan 256, 2, 2) 535169689Skan 536169689Skan/* Incremental SSA updates for virtual operands may be very slow if 537169689Skan there is a large number of mappings to process. In those cases, it 538169689Skan is faster to rewrite the virtual symbols from scratch as if they 539169689Skan had been recently introduced. This heuristic cannot be applied to 540169689Skan SSA mappings for real SSA names, only symbols kept in FUD chains. 541169689Skan 542169689Skan PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual 543169689Skan mappings that should be registered to trigger the heuristic. 544169689Skan 545169689Skan PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between 546169689Skan mappings and symbols. If the number of virtual mappings is 547169689Skan PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of 548169689Skan virtual symbols to be updated, then the updater switches to a full 549169689Skan update for those symbols. */ 550169689SkanDEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS, 551169689Skan "min-virtual-mappings", 552169689Skan "Minimum number of virtual mappings to consider switching to full virtual renames", 553169689Skan 100, 0, 0) 554169689Skan 555169689SkanDEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO, 556169689Skan "virtual-mappings-ratio", 557169689Skan "Ratio between virtual mappings and virtual symbols to do full virtual renames", 558169689Skan 3, 0, 0) 559169689Skan 560169689SkanDEFPARAM (PARAM_SSP_BUFFER_SIZE, 561169689Skan "ssp-buffer-size", 562169689Skan "The lower bound for a buffer to be considered for stack smashing protection", 563169689Skan 8, 1, 0) 564169689Skan 565169689Skan/* When we thread through a block we have to make copies of the 566169689Skan statements within the block. Clearly for large blocks the code 567169689Skan duplication is bad. 568169689Skan 569169689Skan PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number 570169689Skan of statements and PHI nodes allowed in a block which is going to 571169689Skan be duplicated for thread jumping purposes. 572169689Skan 573169689Skan Some simple analysis showed that more than 99% of the jump 574169689Skan threading opportunities are for blocks with less than 15 575169689Skan statements. So we can get the benefits of jump threading 576169689Skan without excessive code bloat for pathological cases with the 577169689Skan throttle set at 15 statements. */ 578169689SkanDEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS, 579169689Skan "max-jump-thread-duplication-stmts", 580169689Skan "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps", 581169689Skan 15, 0, 0) 582169689Skan 583169689Skan/* This is the maximum number of fields a variable may have before the pointer analysis machinery 584169689Skan will stop trying to treat it in a field-sensitive manner. 585169689Skan There are programs out there with thousands of fields per structure, and handling them 586169689Skan field-sensitively is not worth the cost. */ 587169689SkanDEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE, 588169689Skan "max-fields-for-field-sensitive", 589169689Skan "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable", 590169689Skan 100, 0, 0) 591169689Skan 592169689SkanDEFPARAM(PARAM_MAX_SCHED_READY_INSNS, 593169689Skan "max-sched-ready-insns", 594169689Skan "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass", 595169689Skan 100, 0, 0) 596169689Skan 59790075Sobrien/* 59890075SobrienLocal variables: 59990075Sobrienmode:c 60090075SobrienEnd: */ 601