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c6d9a88c | 1 | /* params.def - Run-time parameters. |
737c38d1 | 2 | Copyright (C) 2001, 2002 Free Software Foundation, Inc. |
c6d9a88c MM |
3 | Written by Mark Mitchell <mark@codesourcery.com>. |
4 | ||
1322177d | 5 | This file is part of GCC. |
c6d9a88c | 6 | |
1322177d LB |
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. | |
c6d9a88c | 11 | |
1322177d LB |
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. | |
c6d9a88c MM |
16 | |
17 | You should have received a copy of the GNU General Public License | |
1322177d LB |
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. | |
c6d9a88c MM |
21 | |
22 | */ | |
23 | ||
24 | /* This file contains definitions for language-independent | |
25 | parameters. The DEFPARAM macro takes 4 arguments: | |
26 | ||
0443f602 | 27 | - The enumeral corresponding to this parameter. |
c6d9a88c MM |
28 | |
29 | - The name that can be used to set this parameter using the | |
30 | command-line option `--param <name>=<value>'. | |
31 | ||
32 | - A help string explaining how the parameter is used. | |
33 | ||
1c4c47db JO |
34 | - A default value for the parameter. |
35 | ||
36 | Be sure to add an entry to invoke.texi summarizing the parameter. */ | |
c6d9a88c | 37 | |
a6227154 KG |
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", | |
bc522472 | 53 | "The maximum number of instructions in a single function eligible for inlining", |
a6227154 KG |
54 | 300) |
55 | ||
bc522472 KG |
56 | /* The single function inlining limit for functions that are |
57 | inlined by virtue of -finline-functions (-O3). | |
58 | This limit should be chosen to be below or equal to the limit | |
59 | that is applied to functions marked inlined (or defined in the | |
60 | class declaration in C++) given by the "max-inline-insns-single" | |
61 | parameter. | |
62 | The default value is 300. */ | |
63 | DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO, | |
64 | "max-inline-insns-auto", | |
65 | "The maximum number of instructions when automatically inlining", | |
66 | 300) | |
67 | ||
68 | /* The repeated inlining limit. After this number of instructions | |
a6227154 KG |
69 | (in the internal gcc representation, not real machine instructions) |
70 | got inlined by repeated inlining, gcc starts to decrease the maximum | |
71 | number of inlinable instructions in the tree inliner. | |
72 | This is done by a linear function, see "max-inline-slope" parameter. | |
73 | It is necessary in order to limit the compile-time resources, that | |
74 | could otherwise become very high. | |
75 | It is recommended to set this value to twice the value of the single | |
76 | function limit (set by the "max-inline-insns-single" parameter) or | |
bc522472 | 77 | higher. The default value is 600. |
a6227154 KG |
78 | Higher values mean that more inlining is done, resulting in |
79 | better performance of the code, at the expense of higher | |
80 | compile-time resource (time, memory) requirements and larger | |
bc522472 | 81 | binaries. */ |
c6d9a88c MM |
82 | DEFPARAM (PARAM_MAX_INLINE_INSNS, |
83 | "max-inline-insns", | |
bc522472 | 84 | "The maximum number of instructions by repeated inlining before gcc starts to throttle inlining", |
eb77eeb3 | 85 | 600) |
c6d9a88c | 86 | |
a6227154 KG |
87 | /* After the repeated inline limit has been exceeded (see |
88 | "max-inline-insns" parameter), a linear function is used to | |
89 | decrease the size of single functions eligible for inlining. | |
90 | The slope of this linear function is given the negative | |
91 | reciprocal value (-1/x) of this parameter. | |
bc522472 | 92 | The default value is 32. |
a6227154 KG |
93 | This linear function is used until it falls below a minimum |
94 | value specified by the "min-inline-insns" parameter. */ | |
95 | DEFPARAM (PARAM_MAX_INLINE_SLOPE, | |
96 | "max-inline-slope", | |
8e854b76 | 97 | "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", |
a6227154 KG |
98 | 32) |
99 | ||
100 | /* When gcc has inlined so many instructions (by repeated | |
101 | inlining) that the throttling limits the inlining very much, | |
102 | inlining for very small functions is still desirable to | |
bc522472 | 103 | achieve good runtime performance. The size of single functions |
a6227154 | 104 | (measured in gcc instructions) which will still be eligible for |
bc522472 | 105 | inlining then is given by this parameter. It defaults to 130. |
a6227154 KG |
106 | Only much later (after exceeding 128 times the recursive limit) |
107 | inlining is cut down completely. */ | |
108 | DEFPARAM (PARAM_MIN_INLINE_INSNS, | |
109 | "min-inline-insns", | |
110 | "The number of instructions in a single functions still eligible to inlining after a lot recursive inlining", | |
111 | 130) | |
112 | ||
bc522472 KG |
113 | /* For languages that (still) use the RTL inliner, we can specify |
114 | limits for the RTL inliner separately. | |
115 | The parameter here defines the maximum number of RTL instructions | |
116 | a function may have to be eligible for inlining in the RTL inliner. | |
117 | The default value is 600. */ | |
118 | DEFPARAM (PARAM_MAX_INLINE_INSNS_RTL, | |
119 | "max-inline-insns-rtl", | |
120 | "The maximum number of instructions for the RTL inliner", | |
121 | 600) | |
122 | ||
0443f602 JO |
123 | /* The maximum number of instructions to consider when looking for an |
124 | instruction to fill a delay slot. If more than this arbitrary | |
125 | number of instructions is searched, the time savings from filling | |
126 | the delay slot will be minimal so stop searching. Increasing | |
127 | values mean more aggressive optimization, making the compile time | |
128 | increase with probably small improvement in executable run time. */ | |
129 | DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH, | |
130 | "max-delay-slot-insn-search", | |
131 | "The maximum number of instructions to consider to fill a delay slot", | |
132 | 100) | |
133 | ||
d5d063d7 JO |
134 | /* When trying to fill delay slots, the maximum number of instructions |
135 | to consider when searching for a block with valid live register | |
136 | information. Increasing this arbitrarily chosen value means more | |
137 | aggressive optimization, increasing the compile time. This | |
138 | parameter should be removed when the delay slot code is rewritten | |
139 | to maintain the control-flow graph. */ | |
140 | DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH, | |
141 | "max-delay-slot-live-search", | |
142 | "The maximum number of instructions to consider to find accurate live register information", | |
143 | 333) | |
144 | ||
4a121cc3 | 145 | /* This parameter limits the number of branch elements that the |
ff7cc307 | 146 | scheduler will track anti-dependencies through without resetting |
4a121cc3 | 147 | the tracking mechanism. Large functions with few calls or barriers |
ff7cc307 | 148 | can generate lists containing many 1000's of dependencies. Generally |
4a121cc3 AM |
149 | the compiler either uses all available memory, or runs for far too long. */ |
150 | DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH, | |
151 | "max-pending-list-length", | |
152 | "The maximum length of scheduling's pending operations list", | |
153 | 32) | |
154 | ||
f1fa37ff MM |
155 | /* The GCSE optimization will be disabled if it would require |
156 | significantly more memory than this value. */ | |
157 | DEFPARAM(PARAM_MAX_GCSE_MEMORY, | |
158 | "max-gcse-memory", | |
159 | "The maximum amount of memory to be allocated by GCSE", | |
160 | 50 * 1024 * 1024) | |
991b6592 | 161 | /* The number of repetitions of copy/const prop and PRE to run. */ |
740f35a0 DB |
162 | DEFPARAM(PARAM_MAX_GCSE_PASSES, |
163 | "max-gcse-passes", | |
164 | "The maximum number of passes to make when doing GCSE", | |
165 | 1) | |
03e9dbc9 MM |
166 | |
167 | /* This parameter limits the number of insns in a loop that will be unrolled, | |
168 | and by how much the loop is unrolled. */ | |
169 | DEFPARAM(PARAM_MAX_UNROLLED_INSNS, | |
170 | "max-unrolled-insns", | |
171 | "The maximum number of instructions to consider to unroll in a loop", | |
b17d5d7c ZD |
172 | 200) |
173 | /* This parameter limits how many times the loop is unrolled depending | |
174 | on number of insns really executed in each iteration. */ | |
175 | DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS, | |
176 | "max-average-unrolled-insns", | |
177 | "The maximum number of instructions to consider to unroll in a loop on average", | |
178 | 80) | |
179 | /* The maximum number of unrollings of a single loop. */ | |
180 | DEFPARAM(PARAM_MAX_UNROLL_TIMES, | |
181 | "max-unroll-times", | |
182 | "The maximum number of unrollings of a single loop", | |
183 | 8) | |
184 | /* The maximum number of insns of a peeled loop. */ | |
185 | DEFPARAM(PARAM_MAX_PEELED_INSNS, | |
186 | "max-peeled-insns", | |
187 | "The maximum number of insns of a peeled loop", | |
188 | 120) | |
189 | /* The maximum number of peelings of a single loop. */ | |
190 | DEFPARAM(PARAM_MAX_PEEL_TIMES, | |
191 | "max-peel-times", | |
192 | "The maximum number of peelings of a single loop", | |
193 | 16) | |
194 | /* The maximum number of insns of a peeled loop. */ | |
195 | DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS, | |
196 | "max-completely-peeled-insns", | |
197 | "The maximum number of insns of a completely peeled loop", | |
198 | 120) | |
199 | /* The maximum number of peelings of a single loop that is peeled completely. */ | |
200 | DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES, | |
201 | "max-completely-peel-times", | |
202 | "The maximum number of peelings of a single loop that is peeled completely", | |
203 | 16) | |
204 | /* The maximum number of insns of a peeled loop that rolls only once. */ | |
205 | DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS, | |
206 | "max-once-peeled-insns", | |
207 | "The maximum number of insns of a peeled loop that rolls only once", | |
208 | 200) | |
194734e9 | 209 | |
617b465c ZD |
210 | /* The maximum number of insns of an unswitched loop. */ |
211 | DEFPARAM(PARAM_MAX_UNSWITCH_INSNS, | |
212 | "max-unswitch-insns", | |
213 | "The maximum number of insns of an unswitched loop", | |
214 | 50) | |
215 | /* The maximum level of recursion in unswitch_single_loop. */ | |
216 | DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL, | |
217 | "max-unswitch-level", | |
218 | "The maximum number of unswitchings in a single loop", | |
219 | 3) | |
220 | ||
194734e9 JH |
221 | DEFPARAM(HOT_BB_COUNT_FRACTION, |
222 | "hot-bb-count-fraction", | |
5c856b23 JH |
223 | "Select fraction of the maximal count of repetitions of basic block in \ |
224 | program given basic block needs to have to be considered hot", | |
194734e9 JH |
225 | 10000) |
226 | DEFPARAM(HOT_BB_FREQUENCY_FRACTION, | |
227 | "hot-bb-frequency-fraction", | |
5c856b23 JH |
228 | "Select fraction of the maximal frequency of executions of basic \ |
229 | block in function given basic block needs to have to be considered hot", | |
194734e9 | 230 | 1000) |
5c856b23 JH |
231 | DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK, |
232 | "tracer-dynamic-coverage-feedback", | |
233 | "The percentage of function, weighted by execution frequency, that \ | |
234 | must be covered by trace formation. Used when profile feedback is available", | |
235 | 95) | |
236 | DEFPARAM(TRACER_DYNAMIC_COVERAGE, | |
237 | "tracer-dynamic-coverage", | |
238 | "The percentage of function, weighted by execution frequency, that \ | |
239 | must be covered by trace formation. Used when profile feedback is not available", | |
240 | 75) | |
241 | DEFPARAM(TRACER_MAX_CODE_GROWTH, | |
242 | "tracer-max-code-growth", | |
243 | "Maximal code growth caused by tail duplication (in percents)", | |
244 | 100) | |
245 | DEFPARAM(TRACER_MIN_BRANCH_RATIO, | |
246 | "tracer-min-branch-ratio", | |
247 | "Stop reverse growth if the reverse probability of best edge is less \ | |
248 | than this threshold (in percents)", | |
249 | 10) | |
250 | DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK, | |
251 | "tracer-min-branch-probability-feedback", | |
252 | "Stop forward growth if the probability of best edge is less than \ | |
253 | this threshold (in percents). Used when profile feedback is available", | |
66b4e478 | 254 | 80) |
5c856b23 JH |
255 | DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY, |
256 | "tracer-min-branch-probability", | |
257 | "Stop forward growth if the probability of best edge is less than \ | |
258 | this threshold (in percents). Used when profile feedback is not available", | |
259 | 50) | |
3788cc17 | 260 | |
5f24e0dc RH |
261 | /* The maximum number of incoming edges to consider for crossjumping. */ |
262 | DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES, | |
263 | "max-crossjump-edges", | |
264 | "The maximum number of incoming edges to consider for crossjumping", | |
265 | 100) | |
266 | ||
3788cc17 ZW |
267 | #ifdef ENABLE_GC_ALWAYS_COLLECT |
268 | # define GGC_MIN_EXPAND_DEFAULT 0 | |
737c38d1 | 269 | # define GGC_MIN_HEAPSIZE_DEFAULT 0 |
3788cc17 ZW |
270 | #else |
271 | # define GGC_MIN_EXPAND_DEFAULT 30 | |
737c38d1 | 272 | # define GGC_MIN_HEAPSIZE_DEFAULT 4096 |
3788cc17 ZW |
273 | #endif |
274 | ||
275 | DEFPARAM(GGC_MIN_EXPAND, | |
276 | "ggc-min-expand", | |
277 | "Minimum heap expansion to trigger garbage collection, as \ | |
278 | a percentage of the total size of the heap.", | |
279 | GGC_MIN_EXPAND_DEFAULT) | |
280 | ||
3788cc17 ZW |
281 | DEFPARAM(GGC_MIN_HEAPSIZE, |
282 | "ggc-min-heapsize", | |
283 | "Minimum heap size before we start collecting garbage, in kilobytes.", | |
737c38d1 GK |
284 | GGC_MIN_HEAPSIZE_DEFAULT) |
285 | ||
286 | #undef GGC_MIN_EXPAND_DEFAULT | |
287 | #undef GGC_MIN_HEAPSIZE_DEFAULT | |
3788cc17 | 288 | |
c6d9a88c MM |
289 | /* |
290 | Local variables: | |
291 | mode:c | |
292 | End: */ |