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246 lines
10 KiB
Modula-2
246 lines
10 KiB
Modula-2
/* params.def - Run-time parameters.
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Copyright (C) 2001, 2002 Free Software Foundation, Inc.
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Written by Mark Mitchell <mark@codesourcery.com>.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA.
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*/
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/* This file contains definitions for language-independent
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parameters. The DEFPARAM macro takes 4 arguments:
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- The enumeral corresponding to this parameter.
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- The name that can be used to set this parameter using the
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command-line option `--param <name>=<value>'.
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- A help string explaining how the parameter is used.
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- A default value for the parameter.
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Be sure to add an entry to invoke.texi summarizing the parameter. */
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/* The single function inlining limit. This is the maximum size
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of a function counted in internal gcc instructions (not in
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real machine instructions) that is eligible for inlining
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by the tree inliner.
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The default value is 300.
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Only functions marked inline (or methods defined in the class
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definition for C++) are affected by this, unless you set the
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-finline-functions (included in -O3) compiler option.
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There are more restrictions to inlining: If inlined functions
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call other functions, the already inlined instructions are
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counted and once the recursive inline limit (see
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"max-inline-insns" parameter) is exceeded, the acceptable size
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gets decreased. */
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DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
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"max-inline-insns-single",
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"The maximum number of instructions in a single function eligible for inlining",
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300)
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/* The single function inlining limit for functions that are
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inlined by virtue of -finline-functions (-O3).
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This limit should be chosen to be below or equal to the limit
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that is applied to functions marked inlined (or defined in the
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class declaration in C++) given by the "max-inline-insns-single"
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parameter.
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The default value is 300. */
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DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
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"max-inline-insns-auto",
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"The maximum number of instructions when automatically inlining",
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300)
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/* The repeated inlining limit. After this number of instructions
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(in the internal gcc representation, not real machine instructions)
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got inlined by repeated inlining, gcc starts to decrease the maximum
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number of inlinable instructions in the tree inliner.
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This is done by a linear function, see "max-inline-slope" parameter.
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It is necessary in order to limit the compile-time resources, that
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could otherwise become very high.
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It is recommended to set this value to twice the value of the single
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function limit (set by the "max-inline-insns-single" parameter) or
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higher. The default value is 600.
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Higher values mean that more inlining is done, resulting in
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better performance of the code, at the expense of higher
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compile-time resource (time, memory) requirements and larger
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binaries. */
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DEFPARAM (PARAM_MAX_INLINE_INSNS,
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"max-inline-insns",
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"The maximum number of instructions by repeated inlining before gcc starts to throttle inlining",
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600)
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/* After the repeated inline limit has been exceeded (see
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"max-inline-insns" parameter), a linear function is used to
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decrease the size of single functions eligible for inlining.
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The slope of this linear function is given the negative
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reciprocal value (-1/x) of this parameter.
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The default value is 32.
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This linear function is used until it falls below a minimum
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value specified by the "min-inline-insns" parameter. */
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DEFPARAM (PARAM_MAX_INLINE_SLOPE,
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"max-inline-slope",
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"The slope of the linear function throttling inlining after the recursive inlining limit has been reached is given by the negative reciprocal value of this parameter",
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32)
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/* When gcc has inlined so many instructions (by repeated
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inlining) that the throttling limits the inlining very much,
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inlining for very small functions is still desirable to
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achieve good runtime performance. The size of single functions
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(measured in gcc instructions) which will still be eligible for
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inlining then is given by this parameter. It defaults to 130.
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Only much later (after exceeding 128 times the recursive limit)
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inlining is cut down completely. */
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DEFPARAM (PARAM_MIN_INLINE_INSNS,
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"min-inline-insns",
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"The number of instructions in a single functions still eligible to inlining after a lot recursive inlining",
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130)
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/* For languages that (still) use the RTL inliner, we can specify
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limits for the RTL inliner separately.
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The parameter here defines the maximum number of RTL instructions
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a function may have to be eligible for inlining in the RTL inliner.
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The default value is 600. */
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DEFPARAM (PARAM_MAX_INLINE_INSNS_RTL,
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"max-inline-insns-rtl",
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"The maximum number of instructions for the RTL inliner",
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600)
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/* The maximum number of instructions to consider when looking for an
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instruction to fill a delay slot. If more than this arbitrary
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number of instructions is searched, the time savings from filling
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the delay slot will be minimal so stop searching. Increasing
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values mean more aggressive optimization, making the compile time
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increase with probably small improvement in executable run time. */
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DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
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"max-delay-slot-insn-search",
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"The maximum number of instructions to consider to fill a delay slot",
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100)
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/* When trying to fill delay slots, the maximum number of instructions
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to consider when searching for a block with valid live register
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information. Increasing this arbitrarily chosen value means more
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aggressive optimization, increasing the compile time. This
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parameter should be removed when the delay slot code is rewritten
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to maintain the control-flow graph. */
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DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
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"max-delay-slot-live-search",
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"The maximum number of instructions to consider to find accurate live register information",
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333)
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/* This parameter limits the number of branch elements that the
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scheduler will track anti-dependencies through without resetting
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the tracking mechanism. Large functions with few calls or barriers
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can generate lists containing many 1000's of dependencies. Generally
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the compiler either uses all available memory, or runs for far too long. */
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DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
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"max-pending-list-length",
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"The maximum length of scheduling's pending operations list",
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32)
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/* The GCSE optimization will be disabled if it would require
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significantly more memory than this value. */
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DEFPARAM(PARAM_MAX_GCSE_MEMORY,
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"max-gcse-memory",
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"The maximum amount of memory to be allocated by GCSE",
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50 * 1024 * 1024)
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/* The number of repetitions of copy/const prop and PRE to run. */
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DEFPARAM(PARAM_MAX_GCSE_PASSES,
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"max-gcse-passes",
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"The maximum number of passes to make when doing GCSE",
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1)
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/* This parameter limits the number of insns in a loop that will be unrolled,
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and by how much the loop is unrolled. */
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DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
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"max-unrolled-insns",
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"The maximum number of instructions to consider to unroll in a loop",
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100)
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DEFPARAM(HOT_BB_COUNT_FRACTION,
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"hot-bb-count-fraction",
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"Select fraction of the maximal count of repetitions of basic block in \
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program given basic block needs to have to be considered hot",
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10000)
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DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
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"hot-bb-frequency-fraction",
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"Select fraction of the maximal frequency of executions of basic \
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block in function given basic block needs to have to be considered hot",
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1000)
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DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
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"tracer-dynamic-coverage-feedback",
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"The percentage of function, weighted by execution frequency, that \
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must be covered by trace formation. Used when profile feedback is available",
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95)
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DEFPARAM(TRACER_DYNAMIC_COVERAGE,
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"tracer-dynamic-coverage",
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"The percentage of function, weighted by execution frequency, that \
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must be covered by trace formation. Used when profile feedback is not available",
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75)
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DEFPARAM(TRACER_MAX_CODE_GROWTH,
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"tracer-max-code-growth",
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"Maximal code growth caused by tail duplication (in percents)",
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100)
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DEFPARAM(TRACER_MIN_BRANCH_RATIO,
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"tracer-min-branch-ratio",
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"Stop reverse growth if the reverse probability of best edge is less \
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than this threshold (in percents)",
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10)
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DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
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"tracer-min-branch-probability-feedback",
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"Stop forward growth if the probability of best edge is less than \
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this threshold (in percents). Used when profile feedback is available",
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30)
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DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
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"tracer-min-branch-probability",
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"Stop forward growth if the probability of best edge is less than \
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this threshold (in percents). Used when profile feedback is not available",
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50)
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/* The maximum number of incoming edges to consider for crossjumping. */
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DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
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"max-crossjump-edges",
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"The maximum number of incoming edges to consider for crossjumping",
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100)
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#ifdef ENABLE_GC_ALWAYS_COLLECT
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# define GGC_MIN_EXPAND_DEFAULT 0
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# define GGC_MIN_HEAPSIZE_DEFAULT 0
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#else
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# define GGC_MIN_EXPAND_DEFAULT 30
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# define GGC_MIN_HEAPSIZE_DEFAULT 4096
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#endif
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DEFPARAM(GGC_MIN_EXPAND,
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"ggc-min-expand",
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"Minimum heap expansion to trigger garbage collection, as \
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a percentage of the total size of the heap.",
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GGC_MIN_EXPAND_DEFAULT)
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DEFPARAM(GGC_MIN_HEAPSIZE,
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"ggc-min-heapsize",
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"Minimum heap size before we start collecting garbage, in kilobytes.",
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GGC_MIN_HEAPSIZE_DEFAULT)
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#undef GGC_MIN_EXPAND_DEFAULT
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#undef GGC_MIN_HEAPSIZE_DEFAULT
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/*
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Local variables:
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mode:c
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End: */
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