* arm.mc (return_address_mask): Use CC_REGNUM for the condition code
[official-gcc.git] / gcc / params.def
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1 /* params.def - Run-time parameters.
2 Copyright (C) 2001, 2002 Free Software Foundation, Inc.
3 Written by Mark Mitchell <mark@codesourcery.com>.
5 This file is part of GCC.
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 2, or (at your option) any later
10 version.
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.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA.
24 /* This file contains definitions for language-independent
25 parameters. The DEFPARAM macro takes 4 arguments:
27 - The enumeral corresponding to this parameter.
29 - The name that can be used to set this parameter using the
30 command-line option `--param <name>=<value>'.
32 - A help string explaining how the parameter is used.
34 - A default value for the parameter.
36 Be sure to add an entry to invoke.texi summarizing the parameter. */
38 /* The single function inlining limit. This is the maximum size
39 of a function counted in internal gcc instructions (not in
40 real machine instructions) that is eligible for inlining
41 by the tree inliner.
42 The default value is 300.
43 Only functions marked inline (or methods defined in the class
44 definition for C++) are affected by this, unless you set the
45 -finline-functions (included in -O3) compiler option.
46 There are more restrictions to inlining: If inlined functions
47 call other functions, the already inlined instructions are
48 counted and once the recursive inline limit (see
49 "max-inline-insns" parameter) is exceeded, the acceptable size
50 gets decreased. */
51 DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
52 "max-inline-insns-single",
53 "The maximum number of instructions in a single function eliglible for inlining",
54 300)
56 /* The repeated inlining limit. After this number of instructions
57 (in the internal gcc representation, not real machine instructions)
58 got inlined by repeated inlining, gcc starts to decrease the maximum
59 number of inlinable instructions in the tree inliner.
60 This is done by a linear function, see "max-inline-slope" parameter.
61 It is necessary in order to limit the compile-time resources, that
62 could otherwise become very high.
63 It is recommended to set this value to twice the value of the single
64 function limit (set by the "max-inline-insns-single" parameter) or
65 higher. The default value is 600.
66 Higher values mean that more inlining is done, resulting in
67 better performance of the code, at the expense of higher
68 compile-time resource (time, memory) requirements and larger
69 binaries.
70 This parameters also controls the maximum size of functions considered
71 for inlining in the RTL inliner. */
72 DEFPARAM (PARAM_MAX_INLINE_INSNS,
73 "max-inline-insns",
74 "The maximuem number of instructions by repeated inlining before gcc starts to throttle inlining",
75 600)
77 /* After the repeated inline limit has been exceeded (see
78 "max-inline-insns" parameter), a linear function is used to
79 decrease the size of single functions eligible for inlining.
80 The slope of this linear function is given the negative
81 reciprocal value (-1/x) of this parameter.
82 The default vlue is 32.
83 This linear function is used until it falls below a minimum
84 value specified by the "min-inline-insns" parameter. */
85 DEFPARAM (PARAM_MAX_INLINE_SLOPE,
86 "max-inline-slope",
87 "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",
88 32)
90 /* When gcc has inlined so many instructions (by repeated
91 inlining) that the throttling limits the inlining very much,
92 inlining for very small functions is still desirable to
93 achieve good runtime performance. The size of single functions
94 (measured in gcc instructions) which will still be eligible for
95 inlining then is given by this parameter. It defaults to 130.
96 Only much later (after exceeding 128 times the recursive limit)
97 inlining is cut down completely. */
98 DEFPARAM (PARAM_MIN_INLINE_INSNS,
99 "min-inline-insns",
100 "The number of instructions in a single functions still eligible to inlining after a lot recursive inlining",
101 130)
103 /* The maximum number of instructions to consider when looking for an
104 instruction to fill a delay slot. If more than this arbitrary
105 number of instructions is searched, the time savings from filling
106 the delay slot will be minimal so stop searching. Increasing
107 values mean more aggressive optimization, making the compile time
108 increase with probably small improvement in executable run time. */
109 DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
110 "max-delay-slot-insn-search",
111 "The maximum number of instructions to consider to fill a delay slot",
112 100)
114 /* When trying to fill delay slots, the maximum number of instructions
115 to consider when searching for a block with valid live register
116 information. Increasing this arbitrarily chosen value means more
117 aggressive optimization, increasing the compile time. This
118 parameter should be removed when the delay slot code is rewritten
119 to maintain the control-flow graph. */
120 DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
121 "max-delay-slot-live-search",
122 "The maximum number of instructions to consider to find accurate live register information",
123 333)
125 /* This parameter limits the number of branch elements that the
126 scheduler will track anti-dependencies through without resetting
127 the tracking mechanism. Large functions with few calls or barriers
128 can generate lists containing many 1000's of dependencies. Generally
129 the compiler either uses all available memory, or runs for far too long. */
130 DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
131 "max-pending-list-length",
132 "The maximum length of scheduling's pending operations list",
135 /* The GCSE optimization will be disabled if it would require
136 significantly more memory than this value. */
137 DEFPARAM(PARAM_MAX_GCSE_MEMORY,
138 "max-gcse-memory",
139 "The maximum amount of memory to be allocated by GCSE",
140 50 * 1024 * 1024)
141 /* The number of repetitions of copy/const prop and PRE to run. */
142 DEFPARAM(PARAM_MAX_GCSE_PASSES,
143 "max-gcse-passes",
144 "The maximum number of passes to make when doing GCSE",
147 /* This parameter limits the number of insns in a loop that will be unrolled,
148 and by how much the loop is unrolled. */
149 DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
150 "max-unrolled-insns",
151 "The maximum number of instructions to consider to unroll in a loop",
152 100)
154 /* The maximum number of insns of an unswitched loop. */
155 DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
156 "max-unswitch-insns",
157 "The maximum number of insns of an unswitched loop",
159 /* The maximum level of recursion in unswitch_single_loop. */
160 DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
161 "max-unswitch-level",
162 "The maximum number of unswitchings in a single loop",
165 DEFPARAM(HOT_BB_COUNT_FRACTION,
166 "hot-bb-count-fraction",
167 "Select fraction of the maximal count of repetitions of basic block in \
168 program given basic block needs to have to be considered hot",
169 10000)
170 DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
171 "hot-bb-frequency-fraction",
172 "Select fraction of the maximal frequency of executions of basic \
173 block in function given basic block needs to have to be considered hot",
174 1000)
175 DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
176 "tracer-dynamic-coverage-feedback",
177 "The percentage of function, weighted by execution frequency, that \
178 must be covered by trace formation. Used when profile feedback is available",
180 DEFPARAM(TRACER_DYNAMIC_COVERAGE,
181 "tracer-dynamic-coverage",
182 "The percentage of function, weighted by execution frequency, that \
183 must be covered by trace formation. Used when profile feedback is not available",
185 DEFPARAM(TRACER_MAX_CODE_GROWTH,
186 "tracer-max-code-growth",
187 "Maximal code growth caused by tail duplication (in percents)",
188 100)
189 DEFPARAM(TRACER_MIN_BRANCH_RATIO,
190 "tracer-min-branch-ratio",
191 "Stop reverse growth if the reverse probability of best edge is less \
192 than this threshold (in percents)",
194 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
195 "tracer-min-branch-probability-feedback",
196 "Stop forward growth if the probability of best edge is less than \
197 this threshold (in percents). Used when profile feedback is available",
199 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
200 "tracer-min-branch-probability",
201 "Stop forward growth if the probability of best edge is less than \
202 this threshold (in percents). Used when profile feedback is not available",
205 #ifdef ENABLE_GC_ALWAYS_COLLECT
206 # define GGC_MIN_EXPAND_DEFAULT 0
207 # define GGC_MIN_HEAPSIZE_DEFAULT 0
208 #else
209 # define GGC_MIN_EXPAND_DEFAULT 30
210 # define GGC_MIN_HEAPSIZE_DEFAULT 4096
211 #endif
213 DEFPARAM(GGC_MIN_EXPAND,
214 "ggc-min-expand",
215 "Minimum heap expansion to trigger garbage collection, as \
216 a percentage of the total size of the heap.",
217 GGC_MIN_EXPAND_DEFAULT)
219 DEFPARAM(GGC_MIN_HEAPSIZE,
220 "ggc-min-heapsize",
221 "Minimum heap size before we start collecting garbage, in kilobytes.",
222 GGC_MIN_HEAPSIZE_DEFAULT)
224 #undef GGC_MIN_EXPAND_DEFAULT
225 #undef GGC_MIN_HEAPSIZE_DEFAULT
228 Local variables:
229 mode:c
230 End: */