/* params.def - Run-time parameters. Copyright (C) 2001, 2002, 2004, 2005 Free Software Foundation, Inc. Written by Mark Mitchell <mark@codesourcery.com>. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING. If not, write to the Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* This file contains definitions for language-independent parameters. The DEFPARAM macro takes 6 arguments: - The enumeral corresponding to this parameter. - The name that can be used to set this parameter using the command-line option `--param <name>=<value>'. - A help string explaining how the parameter is used. - A default value for the parameter. - The minimum acceptable value for the parameter. - The maximum acceptable value for the parameter (if greater than the minimum). Be sure to add an entry to invoke.texi summarizing the parameter. */ /* The maximum number of fields in a variable with only implicit uses for which structure aliasing will consider trying to track each field. The default is 5. */ DEFPARAM (PARAM_SALIAS_MAX_IMPLICIT_FIELDS, "salias-max-implicit-fields", "The maximum number of fields in a structure variable without direct structure accesses that GCC will attempt to track separately", 5, 0, 0) /* The maximum number of array elements structure aliasing will decompose an array for. The default is 4. */ DEFPARAM (PARAM_SALIAS_MAX_ARRAY_ELEMENTS, "salias-max-array-elements", "The maximum number of elements in an array for wich we track its elements separately", 4, 0, 0) /* The maximum structure size at which the scalar replacement of aggregates (SRA) pass will perform block copies. The default value, 0, implies that GCC will select the most appropriate size itself. */ DEFPARAM (PARAM_SRA_MAX_STRUCTURE_SIZE, "sra-max-structure-size", "The maximum structure size (in bytes) for which GCC will " "use by-element copies", 0, 0, 0) /* The maximum number of structure fields which the SRA pass will instantiate to avoid block copies. The default value, 0, implies that GCC will select the appropriate value itself. */ DEFPARAM (PARAM_SRA_MAX_STRUCTURE_COUNT, "sra-max-structure-count", "The maximum number of structure fields for which GCC will " "use by-element copies", 0, 0, 0) /* The ratio between instantiated fields and the complete structure size. We say that if the ratio of the number of bytes in instantiated fields to the number of bytes in the complete structure exceeds this parameter, or if the number of instantiated fields to the total number of fields exceeds this parameter, then block copies are not used. The default is 75%. */ DEFPARAM (PARAM_SRA_FIELD_STRUCTURE_RATIO, "sra-field-structure-ratio", "The threshold ratio between instantiated fields and the total structure size", 75, 0, 100) /* The single function inlining limit. This is the maximum size of a function counted in internal gcc instructions (not in real machine instructions) that is eligible for inlining by the tree inliner. The default value is 450. Only functions marked inline (or methods defined in the class definition for C++) are affected by this. There are more restrictions to inlining: If inlined functions call other functions, the already inlined instructions are counted and once the recursive inline limit (see "max-inline-insns" parameter) is exceeded, the acceptable size gets decreased. */ DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE, "max-inline-insns-single", "The maximum number of instructions in a single function eligible for inlining", 450, 0, 0) /* The single function inlining limit for functions that are inlined by virtue of -finline-functions (-O3). This limit should be chosen to be below or equal to the limit that is applied to functions marked inlined (or defined in the class declaration in C++) given by the "max-inline-insns-single" parameter. The default value is 90. */ DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO, "max-inline-insns-auto", "The maximum number of instructions when automatically inlining", 90, 0, 0) DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE, "max-inline-insns-recursive", "The maximum number of instructions inline function can grow to via recursive inlining", 450, 0, 0) DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO, "max-inline-insns-recursive-auto", "The maximum number of instructions non-inline function can grow to via recursive inlining", 450, 0, 0) DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH, "max-inline-recursive-depth", "The maximum depth of recursive inlining for inline functions", 8, 0, 0) DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO, "max-inline-recursive-depth-auto", "The maximum depth of recursive inlining for non-inline functions", 8, 0, 0) DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY, "min-inline-recursive-probability", "Inline recursively only when the probability of call being executed exceeds the parameter", 10, 0, 0) /* Limit the number of expansions created by the variable expansion optimization to avoid register pressure. */ DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS, "max-variable-expansions-in-unroller", "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling", 1, 0, 0) /* The maximum number of instructions to consider when looking for an instruction to fill a delay slot. If more than this arbitrary number of instructions is searched, the time savings from filling the delay slot will be minimal so stop searching. Increasing values mean more aggressive optimization, making the compile time increase with probably small improvement in executable run time. */ DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH, "max-delay-slot-insn-search", "The maximum number of instructions to consider to fill a delay slot", 100, 0, 0) /* When trying to fill delay slots, the maximum number of instructions to consider when searching for a block with valid live register information. Increasing this arbitrarily chosen value means more aggressive optimization, increasing the compile time. This parameter should be removed when the delay slot code is rewritten to maintain the control-flow graph. */ DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH, "max-delay-slot-live-search", "The maximum number of instructions to consider to find accurate live register information", 333, 0, 0) /* This parameter limits the number of branch elements that the scheduler will track anti-dependencies through without resetting the tracking mechanism. Large functions with few calls or barriers can generate lists containing many 1000's of dependencies. Generally the compiler either uses all available memory, or runs for far too long. */ DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH, "max-pending-list-length", "The maximum length of scheduling's pending operations list", 32, 0, 0) DEFPARAM(PARAM_LARGE_FUNCTION_INSNS, "large-function-insns", "The size of function body to be considered large", 2700, 0, 0) DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH, "large-function-growth", "Maximal growth due to inlining of large function (in percent)", 100, 0, 0) DEFPARAM(PARAM_LARGE_UNIT_INSNS, "large-unit-insns", "The size of translation unit to be considered large", 10000, 0, 0) DEFPARAM(PARAM_INLINE_UNIT_GROWTH, "inline-unit-growth", "how much can given compilation unit grow because of the inlining (in percent)", 50, 0, 0) DEFPARAM(PARAM_INLINE_CALL_COST, "inline-call-cost", "expense of call operation relative to ordinary arithmetic operations", 16, 0, 0) /* The GCSE optimization will be disabled if it would require significantly more memory than this value. */ DEFPARAM(PARAM_MAX_GCSE_MEMORY, "max-gcse-memory", "The maximum amount of memory to be allocated by GCSE", 50 * 1024 * 1024, 0, 0) /* The number of repetitions of copy/const prop and PRE to run. */ DEFPARAM(PARAM_MAX_GCSE_PASSES, "max-gcse-passes", "The maximum number of passes to make when doing GCSE", 1, 1, 0) /* This is the threshold ratio when to perform partial redundancy elimination after reload. We perform partial redundancy elimination when the following holds: (Redundant load execution count) ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION (Added loads execution count) */ DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION, "gcse-after-reload-partial-fraction", "The threshold ratio for performing partial redundancy elimination after reload", 3, 0, 0) /* This is the threshold ratio of the critical edges execution count compared to the redundant loads execution count that permits performing the load redundancy elimination in gcse after reload. */ DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION, "gcse-after-reload-critical-fraction", "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload", 10, 0, 0) /* This parameter limits the number of insns in a loop that will be unrolled, and by how much the loop is unrolled. This limit should be at most half of the peeling limits: loop unroller decides to not unroll loops that iterate fewer than 2*number of allowed unrollings and thus we would have loops that are neither peeled or unrolled otherwise. */ DEFPARAM(PARAM_MAX_UNROLLED_INSNS, "max-unrolled-insns", "The maximum number of instructions to consider to unroll in a loop", 200, 0, 0) /* This parameter limits how many times the loop is unrolled depending on number of insns really executed in each iteration. */ DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS, "max-average-unrolled-insns", "The maximum number of instructions to consider to unroll in a loop on average", 80, 0, 0) /* The maximum number of unrollings of a single loop. */ DEFPARAM(PARAM_MAX_UNROLL_TIMES, "max-unroll-times", "The maximum number of unrollings of a single loop", 8, 0, 0) /* The maximum number of insns of a peeled loop. */ DEFPARAM(PARAM_MAX_PEELED_INSNS, "max-peeled-insns", "The maximum number of insns of a peeled loop", 400, 0, 0) /* The maximum number of peelings of a single loop. */ DEFPARAM(PARAM_MAX_PEEL_TIMES, "max-peel-times", "The maximum number of peelings of a single loop", 16, 0, 0) /* The maximum number of insns of a peeled loop. */ DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS, "max-completely-peeled-insns", "The maximum number of insns of a completely peeled loop", 400, 0, 0) /* The maximum number of peelings of a single loop that is peeled completely. */ DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES, "max-completely-peel-times", "The maximum number of peelings of a single loop that is peeled completely", 16, 0, 0) /* The maximum number of insns of a peeled loop that rolls only once. */ DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS, "max-once-peeled-insns", "The maximum number of insns of a peeled loop that rolls only once", 400, 0, 0) /* The maximum number of insns of an unswitched loop. */ DEFPARAM(PARAM_MAX_UNSWITCH_INSNS, "max-unswitch-insns", "The maximum number of insns of an unswitched loop", 50, 0, 0) /* The maximum level of recursion in unswitch_single_loop. */ DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL, "max-unswitch-level", "The maximum number of unswitchings in a single loop", 3, 0, 0) /* The maximum number of iterations of a loop the brute force algorithm for analysis of # of iterations of the loop tries to evaluate. */ DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK, "max-iterations-to-track", "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates", 1000, 0, 0) /* A cutoff to avoid costly computations of the number of iterations in the doloop transformation. */ DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST, "max-iterations-computation-cost", "Bound on the cost of an expression to compute the number of iterations", 10, 0, 0) DEFPARAM(PARAM_MAX_SMS_LOOP_NUMBER, "max-sms-loop-number", "Maximum number of loops to perform swing modulo scheduling on (mainly for debugging)", -1, -1, -1) /* This parameter is used to tune SMS MAX II calculations. */ DEFPARAM(PARAM_SMS_MAX_II_FACTOR, "sms-max-ii-factor", "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop", 100, 0, 0) DEFPARAM(PARAM_SMS_DFA_HISTORY, "sms-dfa-history", "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA", 0, 0, 0) DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD, "sms-loop-average-count-threshold", "A threshold on the average loop count considered by the swing modulo scheduler", 0, 0, 0) DEFPARAM(HOT_BB_COUNT_FRACTION, "hot-bb-count-fraction", "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot", 10000, 0, 0) DEFPARAM(HOT_BB_FREQUENCY_FRACTION, "hot-bb-frequency-fraction", "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot", 1000, 0, 0) /* For guessed profiles, the loops having unknown number of iterations are predicted to iterate relatively few (10) times at average. For functions containing one loop with large known number of iterations and other loops having unbounded loops we would end up predicting all the other loops cold that is not usually the case. So we need to artificially flatten the profile. We need to cut the maximal predicted iterations to large enough iterations so the loop appears important, but safely within HOT_BB_COUNT_FRACTION range. */ DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS, "max-predicted-iterations", "The maximum number of loop iterations we predict statically", 100, 0, 0) DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK, "tracer-dynamic-coverage-feedback", "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available", 95, 0, 100) DEFPARAM(TRACER_DYNAMIC_COVERAGE, "tracer-dynamic-coverage", "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available", 75, 0, 100) DEFPARAM(TRACER_MAX_CODE_GROWTH, "tracer-max-code-growth", "Maximal code growth caused by tail duplication (in percent)", 100, 0, 0) DEFPARAM(TRACER_MIN_BRANCH_RATIO, "tracer-min-branch-ratio", "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)", 10, 0, 100) DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK, "tracer-min-branch-probability-feedback", "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available", 80, 0, 100) DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY, "tracer-min-branch-probability", "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available", 50, 0, 100) /* The maximum number of incoming edges to consider for crossjumping. */ DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES, "max-crossjump-edges", "The maximum number of incoming edges to consider for crossjumping", 100, 0, 0) /* The minimum number of matching instructions to consider for crossjumping. */ DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS, "min-crossjump-insns", "The minimum number of matching instructions to consider for crossjumping", 5, 0, 0) /* The maximum number expansion factor when copying basic blocks. */ DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS, "max-grow-copy-bb-insns", "The maximum expansion factor when copying basic blocks", 8, 0, 0) /* The maximum number of insns to duplicate when unfactoring computed gotos. */ DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS, "max-goto-duplication-insns", "The maximum number of insns to duplicate when unfactoring computed gotos", 8, 0, 0) /* The maximum length of path considered in cse. */ DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH, "max-cse-path-length", "The maximum length of path considered in cse", 10, 0, 0) DEFPARAM(PARAM_MAX_CSE_INSNS, "max-cse-insns", "The maximum instructions CSE process before flushing", 1000, 0, 0) /* The cost of expression in loop invariant motion that is considered expensive. */ DEFPARAM(PARAM_LIM_EXPENSIVE, "lim-expensive", "The minimum cost of an expensive expression in the loop invariant motion", 20, 0, 0) /* Bound on number of candidates for induction variables below that all candidates are considered for each use in induction variable optimizations. */ DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND, "iv-consider-all-candidates-bound", "Bound on number of candidates below that all candidates are considered in iv optimizations", 30, 0, 0) /* The induction variable optimizations give up on loops that contain more induction variable uses. */ DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES, "iv-max-considered-uses", "Bound on number of iv uses in loop optimized in iv optimizations", 250, 0, 0) /* If there are at most this number of ivs in the set, try removing unnecessary ivs from the set always. */ DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND, "iv-always-prune-cand-set-bound", "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization", 10, 0, 0) DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE, "scev-max-expr-size", "Bound on size of expressions used in the scalar evolutions analyzer", 20, 0, 0) DEFPARAM(PARAM_VECT_MAX_VERSION_CHECKS, "vect-max-version-checks", "Bound on number of runtime checks inserted by the vectorizer's loop versioning", 6, 0, 0) /* The product of the next two is used to decide whether or not to use .GLOBAL_VAR. See tree-dfa.c. */ DEFPARAM(PARAM_GLOBAL_VAR_THRESHOLD, "global-var-threshold", "Given N calls and V call-clobbered vars in a function. Use .GLOBAL_VAR if NxV is larger than this limit", 500000, 0, 0) DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS, "max-cselib-memory-locations", "The maximum memory locations recorded by cselib", 500, 0, 0) DEFPARAM(PARAM_MAX_FLOW_MEMORY_LOCATIONS, "max-flow-memory-locations", "The maximum memory locations recorded by flow", 100, 0, 0) #ifdef ENABLE_GC_ALWAYS_COLLECT # define GGC_MIN_EXPAND_DEFAULT 0 # define GGC_MIN_HEAPSIZE_DEFAULT 0 #else # define GGC_MIN_EXPAND_DEFAULT 30 # define GGC_MIN_HEAPSIZE_DEFAULT 4096 #endif DEFPARAM(GGC_MIN_EXPAND, "ggc-min-expand", "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap", GGC_MIN_EXPAND_DEFAULT, 0, 0) DEFPARAM(GGC_MIN_HEAPSIZE, "ggc-min-heapsize", "Minimum heap size before we start collecting garbage, in kilobytes", GGC_MIN_HEAPSIZE_DEFAULT, 0, 0) #undef GGC_MIN_EXPAND_DEFAULT #undef GGC_MIN_HEAPSIZE_DEFAULT DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS, "max-reload-search-insns", "The maximum number of instructions to search backward when looking for equivalent reload", 100, 0, 0) DEFPARAM(PARAM_MAX_ALIASED_VOPS, "max-aliased-vops", "The maximum number of virtual operands allowed to represent aliases before triggering alias grouping", 500, 0, 0) DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS, "max-sched-region-blocks", "The maximum number of blocks in a region to be considered for interblock scheduling", 10, 0, 0) DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS, "max-sched-region-insns", "The maximum number of insns in a region to be considered for interblock scheduling", 100, 0, 0) DEFPARAM(PARAM_MIN_SPEC_PROB, "min-spec-prob", "The minimum probability of reaching a source block for interblock speculative scheduling", 40, 0, 0) DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS, "max-sched-extend-regions-iters", "The maximum number of iterations through CFG to extend regions", 0, 0, 0) DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY, "max-sched-insn-conflict-delay", "The maximum conflict delay for an insn to be considered for speculative motion", 3, 1, 10) DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF, "sched-spec-prob-cutoff", "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.", 40, 0, 100) DEFPARAM(PARAM_MAX_LAST_VALUE_RTL, "max-last-value-rtl", "The maximum number of RTL nodes that can be recorded as combiner's last value", 10000, 0, 0) /* INTEGER_CST nodes are shared for values [{-1,0} .. N) for {signed,unsigned} integral types. This determines N. Experimentation shows 256 to be a good value. */ DEFPARAM (PARAM_INTEGER_SHARE_LIMIT, "integer-share-limit", "The upper bound for sharing integer constants", 256, 2, 2) /* Incremental SSA updates for virtual operands may be very slow if there is a large number of mappings to process. In those cases, it is faster to rewrite the virtual symbols from scratch as if they had been recently introduced. This heuristic cannot be applied to SSA mappings for real SSA names, only symbols kept in FUD chains. PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual mappings that should be registered to trigger the heuristic. PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between mappings and symbols. If the number of virtual mappings is PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of virtual symbols to be updated, then the updater switches to a full update for those symbols. */ DEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS, "min-virtual-mappings", "Minimum number of virtual mappings to consider switching to full virtual renames", 100, 0, 0) DEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO, "virtual-mappings-ratio", "Ratio between virtual mappings and virtual symbols to do full virtual renames", 3, 0, 0) DEFPARAM (PARAM_SSP_BUFFER_SIZE, "ssp-buffer-size", "The lower bound for a buffer to be considered for stack smashing protection", 8, 1, 0) /* When we thread through a block we have to make copies of the statements within the block. Clearly for large blocks the code duplication is bad. PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number of statements and PHI nodes allowed in a block which is going to be duplicated for thread jumping purposes. Some simple analysis showed that more than 99% of the jump threading opportunities are for blocks with less than 15 statements. So we can get the benefits of jump threading without excessive code bloat for pathological cases with the throttle set at 15 statements. */ DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS, "max-jump-thread-duplication-stmts", "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps", 15, 0, 0) /* This is the maximum number of fields a variable may have before the pointer analysis machinery will stop trying to treat it in a field-sensitive manner. There are programs out there with thousands of fields per structure, and handling them field-sensitively is not worth the cost. */ DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE, "max-fields-for-field-sensitive", "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable", 100, 0, 0) DEFPARAM(PARAM_MAX_SCHED_READY_INSNS, "max-sched-ready-insns", "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass", 100, 0, 0) /* Local variables: mode:c End: */