/* params.def - Run-time parameters. Copyright (C) 2001 Free Software Foundation, Inc. Written by Mark Mitchell . 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This file contains definitions for language-independent parameters. The DEFPARAM macro takes 4 arguments: - The enumeral corresponding to this parameter. - The name that can be used to set this parameter using the command-line option `--param ='. - A help string explaining how the parameter is used. - A default value for the parameter. Be sure to add an entry to invoke.texi summarizing the parameter. */ /* 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 300. Only functions marked inline (or methods defined in the class definition for C++) are affected by this, unless you set the -finline-functions (included in -O3) compiler option. 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 eliglible for inlining", 300) /* The repeated inlining limit. After this number of instructions (in the internal gcc representation, not real machine instructions) got inlined by repeated inlining, gcc starts to decrease the maximum number of inlinable instructions in the tree inliner. This is done by a linear function, see "max-inline-slope" parameter. It is necessary in order to limit the compile-time resources, that could otherwise become very high. It is recommended to set this value to twice the value of the single function limit (set by the "max-inline-insns-single" parameter) or higher. The default value is 600. Higher values mean that more inlining is done, resulting in better performance of the code, at the expense of higher compile-time resource (time, memory) requirements and larger binaries. This parameters also controls the maximum size of functions considered for inlining in the RTL inliner. */ DEFPARAM (PARAM_MAX_INLINE_INSNS, "max-inline-insns", "The maximuem number of instructions by repeated inlining before gcc starts to throttle inlining", 600) /* After the repeated inline limit has been exceeded (see "max-inline-insns" parameter), a linear function is used to decrease the size of single functions eligible for inlining. The slope of this linear function is given the negative reciprocal value (-1/x) of this parameter. The default vlue is 32. This linear function is used until it falls below a minimum value specified by the "min-inline-insns" parameter. */ DEFPARAM (PARAM_MAX_INLINE_SLOPE, "max-inline-slope", "The slope of the linear funtion throttling inlining after the recursive inlining limit has been reached is given by the negative reciprocal value of this parameter", 32) /* When gcc has inlined so many instructions (by repeated inlining) that the throttling limits the inlining very much, inlining for very small functions is still desirable to achieve good runtime performance. The size of single functions (measured in gcc instructions) which will still be eligible for inlining then is given by this parameter. It defaults to 130. Only much later (after exceeding 128 times the recursive limit) inlining is cut down completely. */ DEFPARAM (PARAM_MIN_INLINE_INSNS, "min-inline-insns", "The number of instructions in a single functions still eligible to inlining after a lot recursive inlining", 130) /* 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) /* 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) /* 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) /* 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) /* 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) /* This parameter limits the number of insns in a loop that will be unrolled, and by how much the loop is unrolled. */ DEFPARAM(PARAM_MAX_UNROLLED_INSNS, "max-unrolled-insns", "The maximum number of instructions to consider to unroll in a loop", 100) 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) 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) /* Local variables: mode:c End: */