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c6d9a88c 1/* params.def - Run-time parameters.
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2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
3 2011
3d8864c0 4 Free Software Foundation, Inc.
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5 Written by Mark Mitchell <mark@codesourcery.com>.
6
1322177d 7This file is part of GCC.
c6d9a88c 8
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9GCC is free software; you can redistribute it and/or modify it under
10the terms of the GNU General Public License as published by the Free
9dcd6f09 11Software Foundation; either version 3, or (at your option) any later
1322177d 12version.
c6d9a88c 13
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14GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15WARRANTY; without even the implied warranty of MERCHANTABILITY or
16FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17for more details.
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18
19You should have received a copy of the GNU General Public License
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20along with GCC; see the file COPYING3. If not see
21<http://www.gnu.org/licenses/>. */
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22
23/* This file contains definitions for language-independent
1eb68dca 24 parameters. The DEFPARAM macro takes 6 arguments:
c6d9a88c 25
0443f602 26 - The enumeral corresponding to this parameter.
c6d9a88c 27
b8698a0f 28 - The name that can be used to set this parameter using the
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29 command-line option `--param <name>=<value>'.
30
31 - A help string explaining how the parameter is used.
32
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33 - A default value for the parameter.
34
9e7705cb 35 - The minimum acceptable value for the parameter.
1eb68dca 36
9e7705cb 37 - The maximum acceptable value for the parameter (if greater than
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38 the minimum).
39
1c4c47db 40 Be sure to add an entry to invoke.texi summarizing the parameter. */
c6d9a88c 41
ea429753 42/* The threshold ratio between current and hottest structure counts.
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43 We say that if the ratio of the current structure count,
44 calculated by profiling, to the hottest structure count
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45 in the program is less than this parameter, then structure
46 reorganization is not applied. The default is 10%. */
47DEFPARAM (PARAM_STRUCT_REORG_COLD_STRUCT_RATIO,
48 "struct-reorg-cold-struct-ratio",
ea429753 49 "The threshold ratio between current and hottest structure counts",
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OG
50 10, 0, 100)
51
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52/* When branch is predicted to be taken with probability lower than this
53 threshold (in percent), then it is considered well predictable. */
54DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME,
55 "predictable-branch-outcome",
67018619 56 "Maximal estimated outcome of branch considered predictable",
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JH
57 2, 0, 50)
58
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59/* The single function inlining limit. This is the maximum size
60 of a function counted in internal gcc instructions (not in
61 real machine instructions) that is eligible for inlining
62 by the tree inliner.
e5c4f28a 63 The default value is 450.
a6227154 64 Only functions marked inline (or methods defined in the class
e5c4f28a 65 definition for C++) are affected by this.
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66 There are more restrictions to inlining: If inlined functions
67 call other functions, the already inlined instructions are
b8698a0f 68 counted and once the recursive inline limit (see
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69 "max-inline-insns" parameter) is exceeded, the acceptable size
70 gets decreased. */
71DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
72 "max-inline-insns-single",
bc522472 73 "The maximum number of instructions in a single function eligible for inlining",
172d54e0 74 400, 0, 0)
a6227154 75
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76/* The single function inlining limit for functions that are
77 inlined by virtue of -finline-functions (-O3).
78 This limit should be chosen to be below or equal to the limit
79 that is applied to functions marked inlined (or defined in the
80 class declaration in C++) given by the "max-inline-insns-single"
81 parameter.
7802ca7c 82 The default value is 40. */
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83DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
84 "max-inline-insns-auto",
85 "The maximum number of instructions when automatically inlining",
7802ca7c 86 40, 0, 0)
bc522472 87
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88DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
89 "max-inline-insns-recursive",
90 "The maximum number of instructions inline function can grow to via recursive inlining",
172d54e0 91 450, 0, 0)
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92
93DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
94 "max-inline-insns-recursive-auto",
95 "The maximum number of instructions non-inline function can grow to via recursive inlining",
172d54e0 96 450, 0, 0)
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97
98DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
99 "max-inline-recursive-depth",
100 "The maximum depth of recursive inlining for inline functions",
e06c0feb 101 8, 0, 0)
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DN
102
103DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
104 "max-inline-recursive-depth-auto",
105 "The maximum depth of recursive inlining for non-inline functions",
e06c0feb 106 8, 0, 0)
6de9cd9a 107
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108DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
109 "min-inline-recursive-probability",
110 "Inline recursively only when the probability of call being executed exceeds the parameter",
111 10, 0, 0)
112
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113/* Limit of iterations of early inliner. This basically bounds number of
114 nested indirect calls early inliner can resolve. Deeper chains are still
115 handled by late inlining. */
116DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS,
117 "max-early-inliner-iterations",
118 "The maximum number of nested indirect inlining performed by early inliner",
119 10, 0, 0)
120
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121/* Limit on probability of entry BB. */
122DEFPARAM (PARAM_COMDAT_SHARING_PROBABILITY,
123 "comdat-sharing-probability",
124 "Probability that COMDAT function will be shared with different compilatoin unit",
125 20, 0, 0)
126
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127/* Limit on probability of entry BB. */
128DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY,
129 "partial-inlining-entry-probability",
130 "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen",
131 70, 0, 0)
132
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133/* Limit the number of expansions created by the variable expansion
134 optimization to avoid register pressure. */
135DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
136 "max-variable-expansions-in-unroller",
5fa534e3 137 "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling",
e06c0feb 138 1, 0, 0)
b8698a0f 139
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140/* Limit loop autovectorization to loops with large enough iteration count. */
141DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND,
142 "min-vect-loop-bound",
143 "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization",
8d888559 144 1, 1, 0)
acdc40df 145
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146/* The maximum number of instructions to consider when looking for an
147 instruction to fill a delay slot. If more than this arbitrary
148 number of instructions is searched, the time savings from filling
149 the delay slot will be minimal so stop searching. Increasing
150 values mean more aggressive optimization, making the compile time
151 increase with probably small improvement in executable run time. */
152DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
153 "max-delay-slot-insn-search",
154 "The maximum number of instructions to consider to fill a delay slot",
e06c0feb 155 100, 0, 0)
0443f602 156
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157/* When trying to fill delay slots, the maximum number of instructions
158 to consider when searching for a block with valid live register
159 information. Increasing this arbitrarily chosen value means more
160 aggressive optimization, increasing the compile time. This
161 parameter should be removed when the delay slot code is rewritten
162 to maintain the control-flow graph. */
163DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
164 "max-delay-slot-live-search",
165 "The maximum number of instructions to consider to find accurate live register information",
e06c0feb 166 333, 0, 0)
d5d063d7 167
b8698a0f 168/* This parameter limits the number of branch elements that the
ff7cc307 169 scheduler will track anti-dependencies through without resetting
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170 the tracking mechanism. Large functions with few calls or barriers
171 can generate lists containing many 1000's of dependencies. Generally
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172 the compiler either uses all available memory, or runs for far too long. */
173DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
174 "max-pending-list-length",
175 "The maximum length of scheduling's pending operations list",
e06c0feb 176 32, 0, 0)
4a121cc3 177
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178DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
179 "large-function-insns",
180 "The size of function body to be considered large",
e5c4f28a 181 2700, 0, 0)
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182DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
183 "large-function-growth",
2cc98056 184 "Maximal growth due to inlining of large function (in percent)",
e06c0feb 185 100, 0, 0)
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186DEFPARAM(PARAM_LARGE_UNIT_INSNS,
187 "large-unit-insns",
188 "The size of translation unit to be considered large",
189 10000, 0, 0)
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190DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
191 "inline-unit-growth",
7b98c16f 192 "How much can given compilation unit grow because of the inlining (in percent)",
d562c668 193 30, 0, 0)
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194DEFPARAM(PARAM_IPCP_UNIT_GROWTH,
195 "ipcp-unit-growth",
7b98c16f 196 "How much can given compilation unit grow because of the interprocedural constant propagation (in percent)",
5e45130d 197 10, 0, 0)
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198DEFPARAM(PARAM_EARLY_INLINING_INSNS,
199 "early-inlining-insns",
7b98c16f 200 "Maximal estimated growth of function body caused by early inlining of single call",
211ceaca 201 10, 0, 0)
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202DEFPARAM(PARAM_LARGE_STACK_FRAME,
203 "large-stack-frame",
204 "The size of stack frame to be considered large",
205 256, 0, 0)
206DEFPARAM(PARAM_STACK_FRAME_GROWTH,
207 "large-stack-frame-growth",
208 "Maximal stack frame growth due to inlining (in percent)",
209 1000, 0, 0)
b58b1157 210
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211/* The GCSE optimization will be disabled if it would require
212 significantly more memory than this value. */
213DEFPARAM(PARAM_MAX_GCSE_MEMORY,
214 "max-gcse-memory",
215 "The maximum amount of memory to be allocated by GCSE",
e06c0feb 216 50 * 1024 * 1024, 0, 0)
3906a4a1 217
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218/* The GCSE optimization of an expression will avoided if the ratio of
219 insertions to deletions is greater than this value. */
220DEFPARAM(PARAM_MAX_GCSE_INSERTION_RATIO,
221 "max-gcse-insertion-ratio",
222 "The maximum ratio of insertions to deletions of expressions in GCSE",
223 20, 0, 0)
224
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225/* This is the threshold ratio when to perform partial redundancy
226 elimination after reload. We perform partial redundancy elimination
227 when the following holds:
228 (Redundant load execution count)
229 ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
230 (Added loads execution count) */
231DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
232 "gcse-after-reload-partial-fraction",
c85ce869 233 "The threshold ratio for performing partial redundancy elimination after reload",
e06c0feb 234 3, 0, 0)
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235/* This is the threshold ratio of the critical edges execution count compared to
236 the redundant loads execution count that permits performing the load
237 redundancy elimination in gcse after reload. */
238DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
239 "gcse-after-reload-critical-fraction",
c85ce869 240 "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload",
e06c0feb 241 10, 0, 0)
20160347
MK
242
243/* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor
244 to calculate maximum distance for which an expression is allowed to move
245 from its rtx_cost. */
246DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO,
247 "gcse-cost-distance-ratio",
248 "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations",
249 10, 0, 0)
250/* GCSE won't restrict distance for which an expression with rtx_cost greater
251 than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move. */
252DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST,
253 "gcse-unrestricted-cost",
254 "Cost at which GCSE optimizations will not constraint the distance an expression can travel",
255 3, 0, 0)
256
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MK
257/* How deep from a given basic block the dominator tree should be searched
258 for expressions to hoist to the block. The value of 0 will avoid limiting
259 the search. */
260DEFPARAM(PARAM_MAX_HOIST_DEPTH,
261 "max-hoist-depth",
262 "Maximum depth of search in the dominator tree for expressions to hoist",
263 30, 0, 0)
264
03e9dbc9 265/* This parameter limits the number of insns in a loop that will be unrolled,
701ad47e 266 and by how much the loop is unrolled.
b8698a0f 267
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268 This limit should be at most half of the peeling limits: loop unroller
269 decides to not unroll loops that iterate fewer than 2*number of allowed
a1105617 270 unrollings and thus we would have loops that are neither peeled or unrolled
701ad47e 271 otherwise. */
03e9dbc9
MM
272DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
273 "max-unrolled-insns",
274 "The maximum number of instructions to consider to unroll in a loop",
e06c0feb 275 200, 0, 0)
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276/* This parameter limits how many times the loop is unrolled depending
277 on number of insns really executed in each iteration. */
278DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
279 "max-average-unrolled-insns",
280 "The maximum number of instructions to consider to unroll in a loop on average",
e06c0feb 281 80, 0, 0)
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282/* The maximum number of unrollings of a single loop. */
283DEFPARAM(PARAM_MAX_UNROLL_TIMES,
284 "max-unroll-times",
285 "The maximum number of unrollings of a single loop",
e06c0feb 286 8, 0, 0)
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287/* The maximum number of insns of a peeled loop. */
288DEFPARAM(PARAM_MAX_PEELED_INSNS,
289 "max-peeled-insns",
290 "The maximum number of insns of a peeled loop",
e06c0feb 291 400, 0, 0)
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292/* The maximum number of peelings of a single loop. */
293DEFPARAM(PARAM_MAX_PEEL_TIMES,
294 "max-peel-times",
295 "The maximum number of peelings of a single loop",
e06c0feb 296 16, 0, 0)
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297/* The maximum number of insns of a peeled loop. */
298DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
299 "max-completely-peeled-insns",
300 "The maximum number of insns of a completely peeled loop",
e06c0feb 301 400, 0, 0)
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ZD
302/* The maximum number of peelings of a single loop that is peeled completely. */
303DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
304 "max-completely-peel-times",
305 "The maximum number of peelings of a single loop that is peeled completely",
e06c0feb 306 16, 0, 0)
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ZD
307/* The maximum number of insns of a peeled loop that rolls only once. */
308DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
309 "max-once-peeled-insns",
310 "The maximum number of insns of a peeled loop that rolls only once",
e06c0feb 311 400, 0, 0)
30bc1dca
RG
312/* The maximum depth of a loop nest we completely peel. */
313DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS,
314 "max-completely-peel-loop-nest-depth",
315 "The maximum depth of a loop nest we completely peel",
316 8, 0, 0)
194734e9 317
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318/* The maximum number of insns of an unswitched loop. */
319DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
320 "max-unswitch-insns",
321 "The maximum number of insns of an unswitched loop",
e06c0feb 322 50, 0, 0)
617b465c
ZD
323/* The maximum level of recursion in unswitch_single_loop. */
324DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
325 "max-unswitch-level",
326 "The maximum number of unswitchings in a single loop",
e06c0feb 327 3, 0, 0)
617b465c 328
e9eb809d
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329/* The maximum number of iterations of a loop the brute force algorithm
330 for analysis of # of iterations of the loop tries to evaluate. */
331DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
332 "max-iterations-to-track",
e06c0feb
NS
333 "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates",
334 1000, 0, 0)
45b9a14b
BS
335/* A cutoff to avoid costly computations of the number of iterations in
336 the doloop transformation. */
337DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST,
338 "max-iterations-computation-cost",
339 "Bound on the cost of an expression to compute the number of iterations",
340 10, 0, 0)
e9eb809d 341
e5626198
AZ
342/* This parameter is used to tune SMS MAX II calculations. */
343DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
344 "sms-max-ii-factor",
e06c0feb
NS
345 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop",
346 100, 0, 0)
e5626198
AZ
347DEFPARAM(PARAM_SMS_DFA_HISTORY,
348 "sms-dfa-history",
5fa534e3 349 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA",
e06c0feb 350 0, 0, 0)
e5626198
AZ
351DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
352 "sms-loop-average-count-threshold",
e06c0feb
NS
353 "A threshold on the average loop count considered by the swing modulo scheduler",
354 0, 0, 0)
e5626198 355
194734e9
JH
356DEFPARAM(HOT_BB_COUNT_FRACTION,
357 "hot-bb-count-fraction",
e06c0feb
NS
358 "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot",
359 10000, 0, 0)
194734e9
JH
360DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
361 "hot-bb-frequency-fraction",
e06c0feb
NS
362 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot",
363 1000, 0, 0)
95b9a3a5 364
edbed3d3
JH
365DEFPARAM (PARAM_ALIGN_THRESHOLD,
366 "align-threshold",
367 "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment",
368 100, 0, 0)
369
370DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS,
371 "align-loop-iterations",
372 "Loops iterating at least selected number of iterations will get loop alignement.",
373 4, 0, 0)
374
95b9a3a5
JH
375/* For guessed profiles, the loops having unknown number of iterations
376 are predicted to iterate relatively few (10) times at average.
377 For functions containing one loop with large known number of iterations
378 and other loops having unbounded loops we would end up predicting all
c83eecad 379 the other loops cold that is not usually the case. So we need to artificially
b8698a0f 380 flatten the profile.
95b9a3a5 381
6416ae7f 382 We need to cut the maximal predicted iterations to large enough iterations
95b9a3a5
JH
383 so the loop appears important, but safely within HOT_BB_COUNT_FRACTION
384 range. */
385
386DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
387 "max-predicted-iterations",
388 "The maximum number of loop iterations we predict statically",
389 100, 0, 0)
5c856b23
JH
390DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
391 "tracer-dynamic-coverage-feedback",
e06c0feb
NS
392 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available",
393 95, 0, 100)
5c856b23
JH
394DEFPARAM(TRACER_DYNAMIC_COVERAGE,
395 "tracer-dynamic-coverage",
e06c0feb
NS
396 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available",
397 75, 0, 100)
5c856b23
JH
398DEFPARAM(TRACER_MAX_CODE_GROWTH,
399 "tracer-max-code-growth",
2cc98056 400 "Maximal code growth caused by tail duplication (in percent)",
e06c0feb 401 100, 0, 0)
5c856b23
JH
402DEFPARAM(TRACER_MIN_BRANCH_RATIO,
403 "tracer-min-branch-ratio",
e06c0feb
NS
404 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)",
405 10, 0, 100)
5c856b23
JH
406DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
407 "tracer-min-branch-probability-feedback",
e06c0feb
NS
408 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available",
409 80, 0, 100)
5c856b23
JH
410DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
411 "tracer-min-branch-probability",
e06c0feb
NS
412 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available",
413 50, 0, 100)
3788cc17 414
5f24e0dc
RH
415/* The maximum number of incoming edges to consider for crossjumping. */
416DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
417 "max-crossjump-edges",
418 "The maximum number of incoming edges to consider for crossjumping",
e06c0feb 419 100, 0, 0)
5f24e0dc 420
12183e0f
PH
421/* The minimum number of matching instructions to consider for crossjumping. */
422DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
423 "min-crossjump-insns",
424 "The minimum number of matching instructions to consider for crossjumping",
e06c0feb 425 5, 0, 0)
12183e0f 426
f935b9e0
DE
427/* The maximum number expansion factor when copying basic blocks. */
428DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
429 "max-grow-copy-bb-insns",
430 "The maximum expansion factor when copying basic blocks",
431 8, 0, 0)
432
bbcb0c05
SB
433/* The maximum number of insns to duplicate when unfactoring computed gotos. */
434DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
435 "max-goto-duplication-insns",
436 "The maximum number of insns to duplicate when unfactoring computed gotos",
437 8, 0, 0)
438
9bf8cfbf
ZD
439/* The maximum length of path considered in cse. */
440DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
441 "max-cse-path-length",
2cc98056 442 "The maximum length of path considered in cse",
e06c0feb 443 10, 0, 0)
95b9a3a5 444DEFPARAM(PARAM_MAX_CSE_INSNS,
921b02cd 445 "max-cse-insns",
95b9a3a5
JH
446 "The maximum instructions CSE process before flushing",
447 1000, 0, 0)
9bf8cfbf 448
a7e5372d
ZD
449/* The cost of expression in loop invariant motion that is considered
450 expensive. */
451DEFPARAM(PARAM_LIM_EXPENSIVE,
452 "lim-expensive",
453 "The minimum cost of an expensive expression in the loop invariant motion",
e06c0feb 454 20, 0, 0)
a7e5372d 455
8b11a64c
ZD
456/* Bound on number of candidates for induction variables below that
457 all candidates are considered for each use in induction variable
458 optimizations. */
459
460DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
461 "iv-consider-all-candidates-bound",
462 "Bound on number of candidates below that all candidates are considered in iv optimizations",
e06c0feb 463 30, 0, 0)
8b11a64c
ZD
464
465/* The induction variable optimizations give up on loops that contain more
466 induction variable uses. */
467
468DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
469 "iv-max-considered-uses",
470 "Bound on number of iv uses in loop optimized in iv optimizations",
e06c0feb 471 250, 0, 0)
8b11a64c 472
36f5ada1
ZD
473/* If there are at most this number of ivs in the set, try removing unnecessary
474 ivs from the set always. */
475
476DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
477 "iv-always-prune-cand-set-bound",
478 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization",
479 10, 0, 0)
480
2412d35c
SP
481DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
482 "scev-max-expr-size",
483 "Bound on size of expressions used in the scalar evolutions analyzer",
34c1de79 484 20, 0, 0)
2412d35c 485
3d8864c0
SP
486DEFPARAM(PARAM_OMEGA_MAX_VARS,
487 "omega-max-vars",
488 "Bound on the number of variables in Omega constraint systems",
489 128, 0, 0)
490
491DEFPARAM(PARAM_OMEGA_MAX_GEQS,
492 "omega-max-geqs",
493 "Bound on the number of inequalities in Omega constraint systems",
494 256, 0, 0)
495
496DEFPARAM(PARAM_OMEGA_MAX_EQS,
497 "omega-max-eqs",
498 "Bound on the number of equalities in Omega constraint systems",
499 128, 0, 0)
500
501DEFPARAM(PARAM_OMEGA_MAX_WILD_CARDS,
502 "omega-max-wild-cards",
503 "Bound on the number of wild cards in Omega constraint systems",
504 18, 0, 0)
505
506DEFPARAM(PARAM_OMEGA_HASH_TABLE_SIZE,
507 "omega-hash-table-size",
508 "Bound on the size of the hash table in Omega constraint systems",
509 550, 0, 0)
510
511DEFPARAM(PARAM_OMEGA_MAX_KEYS,
512 "omega-max-keys",
513 "Bound on the number of keys in Omega constraint systems",
514 500, 0, 0)
515
516DEFPARAM(PARAM_OMEGA_ELIMINATE_REDUNDANT_CONSTRAINTS,
517 "omega-eliminate-redundant-constraints",
518 "When set to 1, use expensive methods to eliminate all redundant constraints",
519 0, 0, 1)
520
bc1edb77
VK
521DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS,
522 "vect-max-version-for-alignment-checks",
523 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check",
c12cc930
KB
524 6, 0, 0)
525
bc1edb77
VK
526DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS,
527 "vect-max-version-for-alias-checks",
528 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alias check",
529 10, 0, 0)
530
c65ecebc
JH
531DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
532 "max-cselib-memory-locations",
533 "The maximum memory locations recorded by cselib",
e06c0feb 534 500, 0, 0)
c65ecebc 535
3788cc17
ZW
536#ifdef ENABLE_GC_ALWAYS_COLLECT
537# define GGC_MIN_EXPAND_DEFAULT 0
737c38d1 538# define GGC_MIN_HEAPSIZE_DEFAULT 0
3788cc17
ZW
539#else
540# define GGC_MIN_EXPAND_DEFAULT 30
737c38d1 541# define GGC_MIN_HEAPSIZE_DEFAULT 4096
3788cc17
ZW
542#endif
543
544DEFPARAM(GGC_MIN_EXPAND,
545 "ggc-min-expand",
e06c0feb
NS
546 "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap",
547 GGC_MIN_EXPAND_DEFAULT, 0, 0)
3788cc17 548
3788cc17
ZW
549DEFPARAM(GGC_MIN_HEAPSIZE,
550 "ggc-min-heapsize",
2cc98056 551 "Minimum heap size before we start collecting garbage, in kilobytes",
e06c0feb 552 GGC_MIN_HEAPSIZE_DEFAULT, 0, 0)
737c38d1
GK
553
554#undef GGC_MIN_EXPAND_DEFAULT
555#undef GGC_MIN_HEAPSIZE_DEFAULT
3788cc17 556
0bcf8261
JH
557DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
558 "max-reload-search-insns",
559 "The maximum number of instructions to search backward when looking for equivalent reload",
e06c0feb 560 100, 0, 0)
0bcf8261 561
f72c6b56
DE
562DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS,
563 "max-sched-region-blocks",
564 "The maximum number of blocks in a region to be considered for interblock scheduling",
e06c0feb 565 10, 0, 0)
f72c6b56
DE
566
567DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS,
568 "max-sched-region-insns",
569 "The maximum number of insns in a region to be considered for interblock scheduling",
e06c0feb 570 100, 0, 0)
f72c6b56 571
e855c69d
AB
572DEFPARAM(PARAM_MAX_PIPELINE_REGION_BLOCKS,
573 "max-pipeline-region-blocks",
574 "The maximum number of blocks in a region to be considered for interblock scheduling",
575 15, 0, 0)
576
577DEFPARAM(PARAM_MAX_PIPELINE_REGION_INSNS,
578 "max-pipeline-region-insns",
579 "The maximum number of insns in a region to be considered for interblock scheduling",
580 200, 0, 0)
581
6f48c21a
PS
582DEFPARAM(PARAM_MIN_SPEC_PROB,
583 "min-spec-prob",
584 "The minimum probability of reaching a source block for interblock speculative scheduling",
585 40, 0, 0)
586
d08eefb9
MK
587DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS,
588 "max-sched-extend-regions-iters",
589 "The maximum number of iterations through CFG to extend regions",
bb83aa4b 590 0, 0, 0)
d08eefb9 591
496d7bb0
MK
592DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY,
593 "max-sched-insn-conflict-delay",
594 "The maximum conflict delay for an insn to be considered for speculative motion",
595 3, 1, 10)
596
597DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF,
598 "sched-spec-prob-cutoff",
599 "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.",
600 40, 0, 100)
601
e855c69d
AB
602DEFPARAM(PARAM_SELSCHED_MAX_LOOKAHEAD,
603 "selsched-max-lookahead",
604 "The maximum size of the lookahead window of selective scheduling",
605 50, 0, 0)
606
607DEFPARAM(PARAM_SELSCHED_MAX_SCHED_TIMES,
608 "selsched-max-sched-times",
609 "Maximum number of times that an insn could be scheduled",
610 2, 0, 0)
611
612DEFPARAM(PARAM_SELSCHED_INSNS_TO_RENAME,
613 "selsched-insns-to-rename",
614 "Maximum number of instructions in the ready list that are considered eligible for renaming",
615 2, 0, 0)
616
617DEFPARAM (PARAM_SCHED_MEM_TRUE_DEP_COST,
618 "sched-mem-true-dep-cost",
619 "Minimal distance between possibly conflicting store and load",
620 1, 0, 0)
621
49c3b9a8
JJ
622DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
623 "max-last-value-rtl",
624 "The maximum number of RTL nodes that can be recorded as combiner's last value",
625 10000, 0, 0)
626
89b0433e
NS
627/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
628 {signed,unsigned} integral types. This determines N.
629 Experimentation shows 256 to be a good value. */
630DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
631 "integer-share-limit",
632 "The upper bound for sharing integer constants",
e06c0feb 633 256, 2, 2)
89b0433e 634
84d65814
DN
635/* Incremental SSA updates for virtual operands may be very slow if
636 there is a large number of mappings to process. In those cases, it
637 is faster to rewrite the virtual symbols from scratch as if they
638 had been recently introduced. This heuristic cannot be applied to
639 SSA mappings for real SSA names, only symbols kept in FUD chains.
640
641 PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual
642 mappings that should be registered to trigger the heuristic.
b8698a0f 643
84d65814
DN
644 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between
645 mappings and symbols. If the number of virtual mappings is
646 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of
647 virtual symbols to be updated, then the updater switches to a full
648 update for those symbols. */
649DEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS,
650 "min-virtual-mappings",
651 "Minimum number of virtual mappings to consider switching to full virtual renames",
652 100, 0, 0)
653
654DEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO,
655 "virtual-mappings-ratio",
656 "Ratio between virtual mappings and virtual symbols to do full virtual renames",
657 3, 0, 0)
658
7d69de61
RH
659DEFPARAM (PARAM_SSP_BUFFER_SIZE,
660 "ssp-buffer-size",
661 "The lower bound for a buffer to be considered for stack smashing protection",
662 8, 1, 0)
663
43f31be5
JL
664/* When we thread through a block we have to make copies of the
665 statements within the block. Clearly for large blocks the code
666 duplication is bad.
667
668 PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number
669 of statements and PHI nodes allowed in a block which is going to
670 be duplicated for thread jumping purposes.
671
672 Some simple analysis showed that more than 99% of the jump
673 threading opportunities are for blocks with less than 15
674 statements. So we can get the benefits of jump threading
675 without excessive code bloat for pathological cases with the
676 throttle set at 15 statements. */
677DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS,
678 "max-jump-thread-duplication-stmts",
679 "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps",
680 15, 0, 0)
98035a75
DB
681
682/* This is the maximum number of fields a variable may have before the pointer analysis machinery
b8698a0f 683 will stop trying to treat it in a field-sensitive manner.
98035a75
DB
684 There are programs out there with thousands of fields per structure, and handling them
685 field-sensitively is not worth the cost. */
686DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE,
687 "max-fields-for-field-sensitive",
688 "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable",
d9338cf0 689 0, 0, 0)
6f8dd94b
EB
690
691DEFPARAM(PARAM_MAX_SCHED_READY_INSNS,
692 "max-sched-ready-insns",
693 "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass",
694 100, 0, 0)
695
47eb5b32
ZD
696/* Prefetching and cache-optimizations related parameters. Default values are
697 usually set by machine description. */
698
699/* The number of insns executed before prefetch is completed. */
700
701DEFPARAM (PARAM_PREFETCH_LATENCY,
702 "prefetch-latency",
703 "The number of insns executed before prefetch is completed",
704 200, 0, 0)
705
706/* The number of prefetches that can run at the same time. */
707
708DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES,
709 "simultaneous-prefetches",
710 "The number of prefetches that can run at the same time",
711 3, 0, 0)
712
46cb0441 713/* The size of L1 cache in kB. */
47eb5b32
ZD
714
715DEFPARAM (PARAM_L1_CACHE_SIZE,
716 "l1-cache-size",
717 "The size of L1 cache",
46cb0441 718 64, 0, 0)
47eb5b32
ZD
719
720/* The size of L1 cache line in bytes. */
721
722DEFPARAM (PARAM_L1_CACHE_LINE_SIZE,
723 "l1-cache-line-size",
724 "The size of L1 cache line",
725 32, 0, 0)
726
46cb0441
ZD
727/* The size of L2 cache in kB. */
728
729DEFPARAM (PARAM_L2_CACHE_SIZE,
730 "l2-cache-size",
731 "The size of L2 cache",
732 512, 0, 0)
733
7313518b
DG
734/* Whether we should use canonical types rather than deep "structural"
735 type checking. Setting this value to 1 (the default) improves
736 compilation performance in the C++ and Objective-C++ front end;
737 this value should only be set to zero to work around bugs in the
738 canonical type system by disabling it. */
739
740DEFPARAM (PARAM_USE_CANONICAL_TYPES,
741 "use-canonical-types",
742 "Whether to use canonical types",
743 1, 0, 1)
f0ed4cfb
NC
744
745DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH,
746 "max-partial-antic-length",
747 "Maximum length of partial antic set when performing tree pre optimization",
748 100, 0, 0)
749
863d2a57
RG
750/* The following is used as a stop-gap limit for cases where really huge
751 SCCs blow up memory and compile-time use too much. If we hit this limit,
752 SCCVN and such FRE and PRE will be not done at all for the current
753 function. */
754
755DEFPARAM (PARAM_SCCVN_MAX_SCC_SIZE,
756 "sccvn-max-scc-size",
757 "Maximum size of a SCC before SCCVN stops processing a function",
758 10000, 10, 0)
759
058e97ec
VM
760DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM,
761 "ira-max-loops-num",
7b98c16f 762 "Max loops number for regional RA",
30ea859e 763 100, 0, 0)
058e97ec 764
311aab06
VM
765DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE,
766 "ira-max-conflict-table-size",
7b98c16f 767 "Max size of conflict table in MB",
7cd06356 768 1000, 0, 0)
311aab06 769
1833192f
VM
770DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS,
771 "ira-loop-reserved-regs",
772 "The number of registers in each class kept unused by loop invariant motion",
773 2, 0, 0)
774
b6e99746
MJ
775/* Switch initialization conversion will refuse to create arrays that are
776 bigger than this parameter times the number of switch branches. */
777
778DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO,
779 "switch-conversion-max-branch-ratio",
780 "The maximum ratio between array size and switch branches for "
781 "a switch conversion to take place",
782 8, 1, 0)
783
e797c5f2
SP
784/* Size of tiles when doing loop blocking. */
785
786DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE,
787 "loop-block-tile-size",
788 "size of tiles for loop blocking",
789 51, 0, 0)
790
4e7dd376
SP
791/* Maximal number of parameters that we allow in a SCoP. */
792
793DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS,
794 "graphite-max-nb-scop-params",
d97c90ae 795 "maximum number of parameters in a SCoP",
4e7dd376
SP
796 10, 0, 0)
797
b6bb0094
SP
798/* Maximal number of basic blocks in the functions analyzed by Graphite. */
799
800DEFPARAM (PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION,
801 "graphite-max-bbs-per-function",
d97c90ae 802 "maximum number of basic blocks per function to be analyzed by Graphite",
b6bb0094
SP
803 100, 0, 0)
804
b1fb9f56
JJ
805/* Avoid doing loop invariant motion on very large loops. */
806
807DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP,
808 "loop-invariant-max-bbs-in-loop",
7b98c16f 809 "Max basic blocks number in loop for loop invariant motion",
b1fb9f56
JJ
810 10000, 0, 0)
811
a70d6342
IR
812/* Avoid SLP vectorization of large basic blocks. */
813DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB,
814 "slp-max-insns-in-bb",
815 "Maximum number of instructions in basic block to be considered for SLP vectorization",
816 1000, 0, 0)
817
db34470d
GS
818DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO,
819 "min-insn-to-prefetch-ratio",
7b98c16f 820 "Min. ratio of insns to prefetches to enable prefetching for "
db34470d
GS
821 "a loop with an unknown trip count",
822 10, 0, 0)
823
824DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO,
825 "prefetch-min-insn-to-mem-ratio",
7b98c16f 826 "Min. ratio of insns to mem ops to enable prefetching in a loop",
db34470d
GS
827 3, 0, 0)
828
ec8c3978
JJ
829/* Set maximum hash table size for var tracking. */
830
831DEFPARAM (PARAM_MAX_VARTRACK_SIZE,
832 "max-vartrack-size",
833 "Max. size of var tracking hash tables",
834 50000000, 0, 0)
835
b5b8b0ac
AO
836/* Set minimum insn uid for non-debug insns. */
837
838DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID,
839 "min-nondebug-insn-uid",
840 "The minimum UID to be used for a nondebug insn",
841 0, 1, 0)
842
07ffa034
MJ
843DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR,
844 "ipa-sra-ptr-growth-factor",
7b98c16f 845 "Maximum allowed growth of size of new parameters ipa-sra replaces "
07ffa034
MJ
846 "a pointer to an aggregate with",
847 2, 0, 0)
848
3949c4a7
MJ
849DEFPARAM (PARAM_DEVIRT_TYPE_LIST_SIZE,
850 "devirt-type-list-size",
851 "Maximum size of a type list associated with each parameter for "
852 "devirtualization",
853 8, 0, 0)
854
852e4bd2
JH
855/* WHOPR partitioning configuration. */
856
857DEFPARAM (PARAM_LTO_PARTITIONS,
858 "lto-partitions",
859 "Number of paritions program should be split to",
860 32, 0, 0)
861
862DEFPARAM (MIN_PARTITION_SIZE,
863 "lto-min-partition",
864 "Size of minimal paritition for WHOPR (in estimated instructions)",
865 1000, 0, 0)
501c95ff
NF
866
867/* Diagnostic parameters. */
868
869DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP,
870 "cxx-max-namespaces-for-diagnostic-help",
871 "Maximum number of namespaces to search for alternatives when "
872 "name lookup fails",
873 1000, 0, 0)
874
c6d9a88c
MM
875/*
876Local variables:
877mode:c
f4b4a3e2
NC
878End:
879*/