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c6d9a88c 1/* params.def - Run-time parameters.
c75c517d 2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3d8864c0 3 Free Software Foundation, Inc.
c6d9a88c
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4 Written by Mark Mitchell <mark@codesourcery.com>.
5
1322177d 6This file is part of GCC.
c6d9a88c 7
1322177d
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8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
9dcd6f09 10Software Foundation; either version 3, or (at your option) any later
1322177d 11version.
c6d9a88c 12
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13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
c6d9a88c
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17
18You should have received a copy of the GNU General Public License
9dcd6f09
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19along with GCC; see the file COPYING3. If not see
20<http://www.gnu.org/licenses/>. */
c6d9a88c
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21
22/* This file contains definitions for language-independent
1eb68dca 23 parameters. The DEFPARAM macro takes 6 arguments:
c6d9a88c 24
0443f602 25 - The enumeral corresponding to this parameter.
c6d9a88c 26
b8698a0f 27 - The name that can be used to set this parameter using the
c6d9a88c
MM
28 command-line option `--param <name>=<value>'.
29
30 - A help string explaining how the parameter is used.
31
1c4c47db
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32 - A default value for the parameter.
33
9e7705cb 34 - The minimum acceptable value for the parameter.
1eb68dca 35
9e7705cb 36 - The maximum acceptable value for the parameter (if greater than
1eb68dca
KZ
37 the minimum).
38
1c4c47db 39 Be sure to add an entry to invoke.texi summarizing the parameter. */
c6d9a88c 40
ea429753 41/* The threshold ratio between current and hottest structure counts.
b8698a0f
L
42 We say that if the ratio of the current structure count,
43 calculated by profiling, to the hottest structure count
e1dc98b2
OG
44 in the program is less than this parameter, then structure
45 reorganization is not applied. The default is 10%. */
46DEFPARAM (PARAM_STRUCT_REORG_COLD_STRUCT_RATIO,
47 "struct-reorg-cold-struct-ratio",
ea429753 48 "The threshold ratio between current and hottest structure counts",
e1dc98b2
OG
49 10, 0, 100)
50
3a4fd356
JH
51/* When branch is predicted to be taken with probability lower than this
52 threshold (in percent), then it is considered well predictable. */
53DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME,
54 "predictable-branch-outcome",
67018619 55 "Maximal estimated outcome of branch considered predictable",
3a4fd356
JH
56 2, 0, 50)
57
a6227154
KG
58/* The single function inlining limit. This is the maximum size
59 of a function counted in internal gcc instructions (not in
60 real machine instructions) that is eligible for inlining
61 by the tree inliner.
e5c4f28a 62 The default value is 450.
a6227154 63 Only functions marked inline (or methods defined in the class
e5c4f28a 64 definition for C++) are affected by this.
a6227154
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65 There are more restrictions to inlining: If inlined functions
66 call other functions, the already inlined instructions are
b8698a0f 67 counted and once the recursive inline limit (see
a6227154
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68 "max-inline-insns" parameter) is exceeded, the acceptable size
69 gets decreased. */
70DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
71 "max-inline-insns-single",
bc522472 72 "The maximum number of instructions in a single function eligible for inlining",
172d54e0 73 400, 0, 0)
a6227154 74
bc522472
KG
75/* The single function inlining limit for functions that are
76 inlined by virtue of -finline-functions (-O3).
77 This limit should be chosen to be below or equal to the limit
78 that is applied to functions marked inlined (or defined in the
79 class declaration in C++) given by the "max-inline-insns-single"
80 parameter.
7802ca7c 81 The default value is 40. */
bc522472
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82DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
83 "max-inline-insns-auto",
84 "The maximum number of instructions when automatically inlining",
7802ca7c 85 40, 0, 0)
bc522472 86
6de9cd9a
DN
87DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
88 "max-inline-insns-recursive",
89 "The maximum number of instructions inline function can grow to via recursive inlining",
172d54e0 90 450, 0, 0)
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DN
91
92DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
93 "max-inline-insns-recursive-auto",
94 "The maximum number of instructions non-inline function can grow to via recursive inlining",
172d54e0 95 450, 0, 0)
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DN
96
97DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
98 "max-inline-recursive-depth",
99 "The maximum depth of recursive inlining for inline functions",
e06c0feb 100 8, 0, 0)
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DN
101
102DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
103 "max-inline-recursive-depth-auto",
104 "The maximum depth of recursive inlining for non-inline functions",
e06c0feb 105 8, 0, 0)
6de9cd9a 106
c5a4444c
JH
107DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
108 "min-inline-recursive-probability",
109 "Inline recursively only when the probability of call being executed exceeds the parameter",
110 10, 0, 0)
111
796bda22
JH
112/* Limit of iterations of early inliner. This basically bounds number of
113 nested indirect calls early inliner can resolve. Deeper chains are still
114 handled by late inlining. */
115DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS,
116 "max-early-inliner-iterations",
117 "The maximum number of nested indirect inlining performed by early inliner",
118 10, 0, 0)
119
3e485f62
JH
120/* Limit on probability of entry BB. */
121DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY,
122 "partial-inlining-entry-probability",
123 "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen",
124 70, 0, 0)
125
f37a4f14
RE
126/* Limit the number of expansions created by the variable expansion
127 optimization to avoid register pressure. */
128DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
129 "max-variable-expansions-in-unroller",
5fa534e3 130 "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling",
e06c0feb 131 1, 0, 0)
b8698a0f 132
acdc40df
DN
133/* Limit loop autovectorization to loops with large enough iteration count. */
134DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND,
135 "min-vect-loop-bound",
136 "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization",
8d888559 137 1, 1, 0)
acdc40df 138
0443f602
JO
139/* The maximum number of instructions to consider when looking for an
140 instruction to fill a delay slot. If more than this arbitrary
141 number of instructions is searched, the time savings from filling
142 the delay slot will be minimal so stop searching. Increasing
143 values mean more aggressive optimization, making the compile time
144 increase with probably small improvement in executable run time. */
145DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
146 "max-delay-slot-insn-search",
147 "The maximum number of instructions to consider to fill a delay slot",
e06c0feb 148 100, 0, 0)
0443f602 149
d5d063d7
JO
150/* When trying to fill delay slots, the maximum number of instructions
151 to consider when searching for a block with valid live register
152 information. Increasing this arbitrarily chosen value means more
153 aggressive optimization, increasing the compile time. This
154 parameter should be removed when the delay slot code is rewritten
155 to maintain the control-flow graph. */
156DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
157 "max-delay-slot-live-search",
158 "The maximum number of instructions to consider to find accurate live register information",
e06c0feb 159 333, 0, 0)
d5d063d7 160
b8698a0f 161/* This parameter limits the number of branch elements that the
ff7cc307 162 scheduler will track anti-dependencies through without resetting
b8698a0f
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163 the tracking mechanism. Large functions with few calls or barriers
164 can generate lists containing many 1000's of dependencies. Generally
4a121cc3
AM
165 the compiler either uses all available memory, or runs for far too long. */
166DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
167 "max-pending-list-length",
168 "The maximum length of scheduling's pending operations list",
e06c0feb 169 32, 0, 0)
4a121cc3 170
b58b1157
JH
171DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
172 "large-function-insns",
173 "The size of function body to be considered large",
e5c4f28a 174 2700, 0, 0)
b58b1157
JH
175DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
176 "large-function-growth",
2cc98056 177 "Maximal growth due to inlining of large function (in percent)",
e06c0feb 178 100, 0, 0)
b4f32d07
JH
179DEFPARAM(PARAM_LARGE_UNIT_INSNS,
180 "large-unit-insns",
181 "The size of translation unit to be considered large",
182 10000, 0, 0)
b58b1157
JH
183DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
184 "inline-unit-growth",
7b98c16f 185 "How much can given compilation unit grow because of the inlining (in percent)",
d562c668 186 30, 0, 0)
5e45130d
JH
187DEFPARAM(PARAM_IPCP_UNIT_GROWTH,
188 "ipcp-unit-growth",
7b98c16f 189 "How much can given compilation unit grow because of the interprocedural constant propagation (in percent)",
5e45130d 190 10, 0, 0)
85057983
JH
191DEFPARAM(PARAM_EARLY_INLINING_INSNS,
192 "early-inlining-insns",
7b98c16f 193 "Maximal estimated growth of function body caused by early inlining of single call",
ac875c2e 194 8, 0, 0)
ff28a94d
JH
195DEFPARAM(PARAM_LARGE_STACK_FRAME,
196 "large-stack-frame",
197 "The size of stack frame to be considered large",
198 256, 0, 0)
199DEFPARAM(PARAM_STACK_FRAME_GROWTH,
200 "large-stack-frame-growth",
201 "Maximal stack frame growth due to inlining (in percent)",
202 1000, 0, 0)
b58b1157 203
f1fa37ff
MM
204/* The GCSE optimization will be disabled if it would require
205 significantly more memory than this value. */
206DEFPARAM(PARAM_MAX_GCSE_MEMORY,
207 "max-gcse-memory",
208 "The maximum amount of memory to be allocated by GCSE",
e06c0feb 209 50 * 1024 * 1024, 0, 0)
3906a4a1 210
f9957958
MH
211/* This is the threshold ratio when to perform partial redundancy
212 elimination after reload. We perform partial redundancy elimination
213 when the following holds:
214 (Redundant load execution count)
215 ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
216 (Added loads execution count) */
217DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
218 "gcse-after-reload-partial-fraction",
c85ce869 219 "The threshold ratio for performing partial redundancy elimination after reload",
e06c0feb 220 3, 0, 0)
f9957958
MH
221/* This is the threshold ratio of the critical edges execution count compared to
222 the redundant loads execution count that permits performing the load
223 redundancy elimination in gcse after reload. */
224DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
225 "gcse-after-reload-critical-fraction",
c85ce869 226 "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload",
e06c0feb 227 10, 0, 0)
20160347
MK
228
229/* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor
230 to calculate maximum distance for which an expression is allowed to move
231 from its rtx_cost. */
232DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO,
233 "gcse-cost-distance-ratio",
234 "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations",
235 10, 0, 0)
236/* GCSE won't restrict distance for which an expression with rtx_cost greater
237 than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move. */
238DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST,
239 "gcse-unrestricted-cost",
240 "Cost at which GCSE optimizations will not constraint the distance an expression can travel",
241 3, 0, 0)
242
03e9dbc9 243/* This parameter limits the number of insns in a loop that will be unrolled,
701ad47e 244 and by how much the loop is unrolled.
b8698a0f 245
701ad47e
JH
246 This limit should be at most half of the peeling limits: loop unroller
247 decides to not unroll loops that iterate fewer than 2*number of allowed
a1105617 248 unrollings and thus we would have loops that are neither peeled or unrolled
701ad47e 249 otherwise. */
03e9dbc9
MM
250DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
251 "max-unrolled-insns",
252 "The maximum number of instructions to consider to unroll in a loop",
e06c0feb 253 200, 0, 0)
b17d5d7c
ZD
254/* This parameter limits how many times the loop is unrolled depending
255 on number of insns really executed in each iteration. */
256DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
257 "max-average-unrolled-insns",
258 "The maximum number of instructions to consider to unroll in a loop on average",
e06c0feb 259 80, 0, 0)
b17d5d7c
ZD
260/* The maximum number of unrollings of a single loop. */
261DEFPARAM(PARAM_MAX_UNROLL_TIMES,
262 "max-unroll-times",
263 "The maximum number of unrollings of a single loop",
e06c0feb 264 8, 0, 0)
b17d5d7c
ZD
265/* The maximum number of insns of a peeled loop. */
266DEFPARAM(PARAM_MAX_PEELED_INSNS,
267 "max-peeled-insns",
268 "The maximum number of insns of a peeled loop",
e06c0feb 269 400, 0, 0)
b17d5d7c
ZD
270/* The maximum number of peelings of a single loop. */
271DEFPARAM(PARAM_MAX_PEEL_TIMES,
272 "max-peel-times",
273 "The maximum number of peelings of a single loop",
e06c0feb 274 16, 0, 0)
b17d5d7c
ZD
275/* The maximum number of insns of a peeled loop. */
276DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
277 "max-completely-peeled-insns",
278 "The maximum number of insns of a completely peeled loop",
e06c0feb 279 400, 0, 0)
b17d5d7c
ZD
280/* The maximum number of peelings of a single loop that is peeled completely. */
281DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
282 "max-completely-peel-times",
283 "The maximum number of peelings of a single loop that is peeled completely",
e06c0feb 284 16, 0, 0)
b17d5d7c
ZD
285/* The maximum number of insns of a peeled loop that rolls only once. */
286DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
287 "max-once-peeled-insns",
288 "The maximum number of insns of a peeled loop that rolls only once",
e06c0feb 289 400, 0, 0)
30bc1dca
RG
290/* The maximum depth of a loop nest we completely peel. */
291DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS,
292 "max-completely-peel-loop-nest-depth",
293 "The maximum depth of a loop nest we completely peel",
294 8, 0, 0)
194734e9 295
617b465c
ZD
296/* The maximum number of insns of an unswitched loop. */
297DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
298 "max-unswitch-insns",
299 "The maximum number of insns of an unswitched loop",
e06c0feb 300 50, 0, 0)
617b465c
ZD
301/* The maximum level of recursion in unswitch_single_loop. */
302DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
303 "max-unswitch-level",
304 "The maximum number of unswitchings in a single loop",
e06c0feb 305 3, 0, 0)
617b465c 306
e9eb809d
ZD
307/* The maximum number of iterations of a loop the brute force algorithm
308 for analysis of # of iterations of the loop tries to evaluate. */
309DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
310 "max-iterations-to-track",
e06c0feb
NS
311 "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates",
312 1000, 0, 0)
45b9a14b
BS
313/* A cutoff to avoid costly computations of the number of iterations in
314 the doloop transformation. */
315DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST,
316 "max-iterations-computation-cost",
317 "Bound on the cost of an expression to compute the number of iterations",
318 10, 0, 0)
e9eb809d 319
e5626198
AZ
320/* This parameter is used to tune SMS MAX II calculations. */
321DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
322 "sms-max-ii-factor",
e06c0feb
NS
323 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop",
324 100, 0, 0)
e5626198
AZ
325DEFPARAM(PARAM_SMS_DFA_HISTORY,
326 "sms-dfa-history",
5fa534e3 327 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA",
e06c0feb 328 0, 0, 0)
e5626198
AZ
329DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
330 "sms-loop-average-count-threshold",
e06c0feb
NS
331 "A threshold on the average loop count considered by the swing modulo scheduler",
332 0, 0, 0)
e5626198 333
194734e9
JH
334DEFPARAM(HOT_BB_COUNT_FRACTION,
335 "hot-bb-count-fraction",
e06c0feb
NS
336 "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot",
337 10000, 0, 0)
194734e9
JH
338DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
339 "hot-bb-frequency-fraction",
e06c0feb
NS
340 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot",
341 1000, 0, 0)
95b9a3a5 342
edbed3d3
JH
343DEFPARAM (PARAM_ALIGN_THRESHOLD,
344 "align-threshold",
345 "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment",
346 100, 0, 0)
347
348DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS,
349 "align-loop-iterations",
350 "Loops iterating at least selected number of iterations will get loop alignement.",
351 4, 0, 0)
352
95b9a3a5
JH
353/* For guessed profiles, the loops having unknown number of iterations
354 are predicted to iterate relatively few (10) times at average.
355 For functions containing one loop with large known number of iterations
356 and other loops having unbounded loops we would end up predicting all
c83eecad 357 the other loops cold that is not usually the case. So we need to artificially
b8698a0f 358 flatten the profile.
95b9a3a5 359
6416ae7f 360 We need to cut the maximal predicted iterations to large enough iterations
95b9a3a5
JH
361 so the loop appears important, but safely within HOT_BB_COUNT_FRACTION
362 range. */
363
364DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
365 "max-predicted-iterations",
366 "The maximum number of loop iterations we predict statically",
367 100, 0, 0)
5c856b23
JH
368DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
369 "tracer-dynamic-coverage-feedback",
e06c0feb
NS
370 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available",
371 95, 0, 100)
5c856b23
JH
372DEFPARAM(TRACER_DYNAMIC_COVERAGE,
373 "tracer-dynamic-coverage",
e06c0feb
NS
374 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available",
375 75, 0, 100)
5c856b23
JH
376DEFPARAM(TRACER_MAX_CODE_GROWTH,
377 "tracer-max-code-growth",
2cc98056 378 "Maximal code growth caused by tail duplication (in percent)",
e06c0feb 379 100, 0, 0)
5c856b23
JH
380DEFPARAM(TRACER_MIN_BRANCH_RATIO,
381 "tracer-min-branch-ratio",
e06c0feb
NS
382 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)",
383 10, 0, 100)
5c856b23
JH
384DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
385 "tracer-min-branch-probability-feedback",
e06c0feb
NS
386 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available",
387 80, 0, 100)
5c856b23
JH
388DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
389 "tracer-min-branch-probability",
e06c0feb
NS
390 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available",
391 50, 0, 100)
3788cc17 392
5f24e0dc
RH
393/* The maximum number of incoming edges to consider for crossjumping. */
394DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
395 "max-crossjump-edges",
396 "The maximum number of incoming edges to consider for crossjumping",
e06c0feb 397 100, 0, 0)
5f24e0dc 398
12183e0f
PH
399/* The minimum number of matching instructions to consider for crossjumping. */
400DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
401 "min-crossjump-insns",
402 "The minimum number of matching instructions to consider for crossjumping",
e06c0feb 403 5, 0, 0)
12183e0f 404
f935b9e0
DE
405/* The maximum number expansion factor when copying basic blocks. */
406DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
407 "max-grow-copy-bb-insns",
408 "The maximum expansion factor when copying basic blocks",
409 8, 0, 0)
410
bbcb0c05
SB
411/* The maximum number of insns to duplicate when unfactoring computed gotos. */
412DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
413 "max-goto-duplication-insns",
414 "The maximum number of insns to duplicate when unfactoring computed gotos",
415 8, 0, 0)
416
9bf8cfbf
ZD
417/* The maximum length of path considered in cse. */
418DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
419 "max-cse-path-length",
2cc98056 420 "The maximum length of path considered in cse",
e06c0feb 421 10, 0, 0)
95b9a3a5 422DEFPARAM(PARAM_MAX_CSE_INSNS,
921b02cd 423 "max-cse-insns",
95b9a3a5
JH
424 "The maximum instructions CSE process before flushing",
425 1000, 0, 0)
9bf8cfbf 426
a7e5372d
ZD
427/* The cost of expression in loop invariant motion that is considered
428 expensive. */
429DEFPARAM(PARAM_LIM_EXPENSIVE,
430 "lim-expensive",
431 "The minimum cost of an expensive expression in the loop invariant motion",
e06c0feb 432 20, 0, 0)
a7e5372d 433
8b11a64c
ZD
434/* Bound on number of candidates for induction variables below that
435 all candidates are considered for each use in induction variable
436 optimizations. */
437
438DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
439 "iv-consider-all-candidates-bound",
440 "Bound on number of candidates below that all candidates are considered in iv optimizations",
e06c0feb 441 30, 0, 0)
8b11a64c
ZD
442
443/* The induction variable optimizations give up on loops that contain more
444 induction variable uses. */
445
446DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
447 "iv-max-considered-uses",
448 "Bound on number of iv uses in loop optimized in iv optimizations",
e06c0feb 449 250, 0, 0)
8b11a64c 450
36f5ada1
ZD
451/* If there are at most this number of ivs in the set, try removing unnecessary
452 ivs from the set always. */
453
454DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
455 "iv-always-prune-cand-set-bound",
456 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization",
457 10, 0, 0)
458
2412d35c
SP
459DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
460 "scev-max-expr-size",
461 "Bound on size of expressions used in the scalar evolutions analyzer",
462 20, 0, 0)
463
3d8864c0
SP
464DEFPARAM(PARAM_OMEGA_MAX_VARS,
465 "omega-max-vars",
466 "Bound on the number of variables in Omega constraint systems",
467 128, 0, 0)
468
469DEFPARAM(PARAM_OMEGA_MAX_GEQS,
470 "omega-max-geqs",
471 "Bound on the number of inequalities in Omega constraint systems",
472 256, 0, 0)
473
474DEFPARAM(PARAM_OMEGA_MAX_EQS,
475 "omega-max-eqs",
476 "Bound on the number of equalities in Omega constraint systems",
477 128, 0, 0)
478
479DEFPARAM(PARAM_OMEGA_MAX_WILD_CARDS,
480 "omega-max-wild-cards",
481 "Bound on the number of wild cards in Omega constraint systems",
482 18, 0, 0)
483
484DEFPARAM(PARAM_OMEGA_HASH_TABLE_SIZE,
485 "omega-hash-table-size",
486 "Bound on the size of the hash table in Omega constraint systems",
487 550, 0, 0)
488
489DEFPARAM(PARAM_OMEGA_MAX_KEYS,
490 "omega-max-keys",
491 "Bound on the number of keys in Omega constraint systems",
492 500, 0, 0)
493
494DEFPARAM(PARAM_OMEGA_ELIMINATE_REDUNDANT_CONSTRAINTS,
495 "omega-eliminate-redundant-constraints",
496 "When set to 1, use expensive methods to eliminate all redundant constraints",
497 0, 0, 1)
498
bc1edb77
VK
499DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS,
500 "vect-max-version-for-alignment-checks",
501 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check",
c12cc930
KB
502 6, 0, 0)
503
bc1edb77
VK
504DEFPARAM(PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS,
505 "vect-max-version-for-alias-checks",
506 "Bound on number of runtime checks inserted by the vectorizer's loop versioning for alias check",
507 10, 0, 0)
508
c65ecebc
JH
509DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
510 "max-cselib-memory-locations",
511 "The maximum memory locations recorded by cselib",
e06c0feb 512 500, 0, 0)
c65ecebc 513
3788cc17
ZW
514#ifdef ENABLE_GC_ALWAYS_COLLECT
515# define GGC_MIN_EXPAND_DEFAULT 0
737c38d1 516# define GGC_MIN_HEAPSIZE_DEFAULT 0
3788cc17
ZW
517#else
518# define GGC_MIN_EXPAND_DEFAULT 30
737c38d1 519# define GGC_MIN_HEAPSIZE_DEFAULT 4096
3788cc17
ZW
520#endif
521
522DEFPARAM(GGC_MIN_EXPAND,
523 "ggc-min-expand",
e06c0feb
NS
524 "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap",
525 GGC_MIN_EXPAND_DEFAULT, 0, 0)
3788cc17 526
3788cc17
ZW
527DEFPARAM(GGC_MIN_HEAPSIZE,
528 "ggc-min-heapsize",
2cc98056 529 "Minimum heap size before we start collecting garbage, in kilobytes",
e06c0feb 530 GGC_MIN_HEAPSIZE_DEFAULT, 0, 0)
737c38d1
GK
531
532#undef GGC_MIN_EXPAND_DEFAULT
533#undef GGC_MIN_HEAPSIZE_DEFAULT
3788cc17 534
0bcf8261
JH
535DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
536 "max-reload-search-insns",
537 "The maximum number of instructions to search backward when looking for equivalent reload",
e06c0feb 538 100, 0, 0)
0bcf8261 539
f72c6b56
DE
540DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS,
541 "max-sched-region-blocks",
542 "The maximum number of blocks in a region to be considered for interblock scheduling",
e06c0feb 543 10, 0, 0)
f72c6b56
DE
544
545DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS,
546 "max-sched-region-insns",
547 "The maximum number of insns in a region to be considered for interblock scheduling",
e06c0feb 548 100, 0, 0)
f72c6b56 549
e855c69d
AB
550DEFPARAM(PARAM_MAX_PIPELINE_REGION_BLOCKS,
551 "max-pipeline-region-blocks",
552 "The maximum number of blocks in a region to be considered for interblock scheduling",
553 15, 0, 0)
554
555DEFPARAM(PARAM_MAX_PIPELINE_REGION_INSNS,
556 "max-pipeline-region-insns",
557 "The maximum number of insns in a region to be considered for interblock scheduling",
558 200, 0, 0)
559
6f48c21a
PS
560DEFPARAM(PARAM_MIN_SPEC_PROB,
561 "min-spec-prob",
562 "The minimum probability of reaching a source block for interblock speculative scheduling",
563 40, 0, 0)
564
d08eefb9
MK
565DEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS,
566 "max-sched-extend-regions-iters",
567 "The maximum number of iterations through CFG to extend regions",
bb83aa4b 568 0, 0, 0)
d08eefb9 569
496d7bb0
MK
570DEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY,
571 "max-sched-insn-conflict-delay",
572 "The maximum conflict delay for an insn to be considered for speculative motion",
573 3, 1, 10)
574
575DEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF,
576 "sched-spec-prob-cutoff",
577 "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.",
578 40, 0, 100)
579
e855c69d
AB
580DEFPARAM(PARAM_SELSCHED_MAX_LOOKAHEAD,
581 "selsched-max-lookahead",
582 "The maximum size of the lookahead window of selective scheduling",
583 50, 0, 0)
584
585DEFPARAM(PARAM_SELSCHED_MAX_SCHED_TIMES,
586 "selsched-max-sched-times",
587 "Maximum number of times that an insn could be scheduled",
588 2, 0, 0)
589
590DEFPARAM(PARAM_SELSCHED_INSNS_TO_RENAME,
591 "selsched-insns-to-rename",
592 "Maximum number of instructions in the ready list that are considered eligible for renaming",
593 2, 0, 0)
594
595DEFPARAM (PARAM_SCHED_MEM_TRUE_DEP_COST,
596 "sched-mem-true-dep-cost",
597 "Minimal distance between possibly conflicting store and load",
598 1, 0, 0)
599
49c3b9a8
JJ
600DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
601 "max-last-value-rtl",
602 "The maximum number of RTL nodes that can be recorded as combiner's last value",
603 10000, 0, 0)
604
89b0433e
NS
605/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
606 {signed,unsigned} integral types. This determines N.
607 Experimentation shows 256 to be a good value. */
608DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
609 "integer-share-limit",
610 "The upper bound for sharing integer constants",
e06c0feb 611 256, 2, 2)
89b0433e 612
84d65814
DN
613/* Incremental SSA updates for virtual operands may be very slow if
614 there is a large number of mappings to process. In those cases, it
615 is faster to rewrite the virtual symbols from scratch as if they
616 had been recently introduced. This heuristic cannot be applied to
617 SSA mappings for real SSA names, only symbols kept in FUD chains.
618
619 PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual
620 mappings that should be registered to trigger the heuristic.
b8698a0f 621
84d65814
DN
622 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between
623 mappings and symbols. If the number of virtual mappings is
624 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of
625 virtual symbols to be updated, then the updater switches to a full
626 update for those symbols. */
627DEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS,
628 "min-virtual-mappings",
629 "Minimum number of virtual mappings to consider switching to full virtual renames",
630 100, 0, 0)
631
632DEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO,
633 "virtual-mappings-ratio",
634 "Ratio between virtual mappings and virtual symbols to do full virtual renames",
635 3, 0, 0)
636
7d69de61
RH
637DEFPARAM (PARAM_SSP_BUFFER_SIZE,
638 "ssp-buffer-size",
639 "The lower bound for a buffer to be considered for stack smashing protection",
640 8, 1, 0)
641
43f31be5
JL
642/* When we thread through a block we have to make copies of the
643 statements within the block. Clearly for large blocks the code
644 duplication is bad.
645
646 PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number
647 of statements and PHI nodes allowed in a block which is going to
648 be duplicated for thread jumping purposes.
649
650 Some simple analysis showed that more than 99% of the jump
651 threading opportunities are for blocks with less than 15
652 statements. So we can get the benefits of jump threading
653 without excessive code bloat for pathological cases with the
654 throttle set at 15 statements. */
655DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS,
656 "max-jump-thread-duplication-stmts",
657 "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps",
658 15, 0, 0)
98035a75
DB
659
660/* This is the maximum number of fields a variable may have before the pointer analysis machinery
b8698a0f 661 will stop trying to treat it in a field-sensitive manner.
98035a75
DB
662 There are programs out there with thousands of fields per structure, and handling them
663 field-sensitively is not worth the cost. */
664DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE,
665 "max-fields-for-field-sensitive",
666 "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable",
d9338cf0 667 0, 0, 0)
6f8dd94b
EB
668
669DEFPARAM(PARAM_MAX_SCHED_READY_INSNS,
670 "max-sched-ready-insns",
671 "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass",
672 100, 0, 0)
673
47eb5b32
ZD
674/* Prefetching and cache-optimizations related parameters. Default values are
675 usually set by machine description. */
676
677/* The number of insns executed before prefetch is completed. */
678
679DEFPARAM (PARAM_PREFETCH_LATENCY,
680 "prefetch-latency",
681 "The number of insns executed before prefetch is completed",
682 200, 0, 0)
683
684/* The number of prefetches that can run at the same time. */
685
686DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES,
687 "simultaneous-prefetches",
688 "The number of prefetches that can run at the same time",
689 3, 0, 0)
690
46cb0441 691/* The size of L1 cache in kB. */
47eb5b32
ZD
692
693DEFPARAM (PARAM_L1_CACHE_SIZE,
694 "l1-cache-size",
695 "The size of L1 cache",
46cb0441 696 64, 0, 0)
47eb5b32
ZD
697
698/* The size of L1 cache line in bytes. */
699
700DEFPARAM (PARAM_L1_CACHE_LINE_SIZE,
701 "l1-cache-line-size",
702 "The size of L1 cache line",
703 32, 0, 0)
704
46cb0441
ZD
705/* The size of L2 cache in kB. */
706
707DEFPARAM (PARAM_L2_CACHE_SIZE,
708 "l2-cache-size",
709 "The size of L2 cache",
710 512, 0, 0)
711
7313518b
DG
712/* Whether we should use canonical types rather than deep "structural"
713 type checking. Setting this value to 1 (the default) improves
714 compilation performance in the C++ and Objective-C++ front end;
715 this value should only be set to zero to work around bugs in the
716 canonical type system by disabling it. */
717
718DEFPARAM (PARAM_USE_CANONICAL_TYPES,
719 "use-canonical-types",
720 "Whether to use canonical types",
721 1, 0, 1)
f0ed4cfb
NC
722
723DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH,
724 "max-partial-antic-length",
725 "Maximum length of partial antic set when performing tree pre optimization",
726 100, 0, 0)
727
863d2a57
RG
728/* The following is used as a stop-gap limit for cases where really huge
729 SCCs blow up memory and compile-time use too much. If we hit this limit,
730 SCCVN and such FRE and PRE will be not done at all for the current
731 function. */
732
733DEFPARAM (PARAM_SCCVN_MAX_SCC_SIZE,
734 "sccvn-max-scc-size",
735 "Maximum size of a SCC before SCCVN stops processing a function",
736 10000, 10, 0)
737
058e97ec
VM
738DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM,
739 "ira-max-loops-num",
7b98c16f 740 "Max loops number for regional RA",
30ea859e 741 100, 0, 0)
058e97ec 742
311aab06
VM
743DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE,
744 "ira-max-conflict-table-size",
7b98c16f 745 "Max size of conflict table in MB",
7cd06356 746 1000, 0, 0)
311aab06 747
1833192f
VM
748DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS,
749 "ira-loop-reserved-regs",
750 "The number of registers in each class kept unused by loop invariant motion",
751 2, 0, 0)
752
b6e99746
MJ
753/* Switch initialization conversion will refuse to create arrays that are
754 bigger than this parameter times the number of switch branches. */
755
756DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO,
757 "switch-conversion-max-branch-ratio",
758 "The maximum ratio between array size and switch branches for "
759 "a switch conversion to take place",
760 8, 1, 0)
761
e797c5f2
SP
762/* Size of tiles when doing loop blocking. */
763
764DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE,
765 "loop-block-tile-size",
766 "size of tiles for loop blocking",
767 51, 0, 0)
768
4e7dd376
SP
769/* Maximal number of parameters that we allow in a SCoP. */
770
771DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS,
772 "graphite-max-nb-scop-params",
d97c90ae 773 "maximum number of parameters in a SCoP",
4e7dd376
SP
774 10, 0, 0)
775
b6bb0094
SP
776/* Maximal number of basic blocks in the functions analyzed by Graphite. */
777
778DEFPARAM (PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION,
779 "graphite-max-bbs-per-function",
d97c90ae 780 "maximum number of basic blocks per function to be analyzed by Graphite",
b6bb0094
SP
781 100, 0, 0)
782
b1fb9f56
JJ
783/* Avoid doing loop invariant motion on very large loops. */
784
785DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP,
786 "loop-invariant-max-bbs-in-loop",
7b98c16f 787 "Max basic blocks number in loop for loop invariant motion",
b1fb9f56
JJ
788 10000, 0, 0)
789
a70d6342
IR
790/* Avoid SLP vectorization of large basic blocks. */
791DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB,
792 "slp-max-insns-in-bb",
793 "Maximum number of instructions in basic block to be considered for SLP vectorization",
794 1000, 0, 0)
795
db34470d
GS
796DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO,
797 "min-insn-to-prefetch-ratio",
7b98c16f 798 "Min. ratio of insns to prefetches to enable prefetching for "
db34470d
GS
799 "a loop with an unknown trip count",
800 10, 0, 0)
801
802DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO,
803 "prefetch-min-insn-to-mem-ratio",
7b98c16f 804 "Min. ratio of insns to mem ops to enable prefetching in a loop",
db34470d
GS
805 3, 0, 0)
806
ec8c3978
JJ
807/* Set maximum hash table size for var tracking. */
808
809DEFPARAM (PARAM_MAX_VARTRACK_SIZE,
810 "max-vartrack-size",
811 "Max. size of var tracking hash tables",
812 50000000, 0, 0)
813
b5b8b0ac
AO
814/* Set minimum insn uid for non-debug insns. */
815
816DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID,
817 "min-nondebug-insn-uid",
818 "The minimum UID to be used for a nondebug insn",
819 0, 1, 0)
820
07ffa034
MJ
821DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR,
822 "ipa-sra-ptr-growth-factor",
7b98c16f 823 "Maximum allowed growth of size of new parameters ipa-sra replaces "
07ffa034
MJ
824 "a pointer to an aggregate with",
825 2, 0, 0)
826
c6d9a88c
MM
827/*
828Local variables:
829mode:c
f4b4a3e2
NC
830End:
831*/