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c6d9a88c 1/* params.def - Run-time parameters.
e42febca 2 Copyright (C) 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
c6d9a88c
MM
3 Written by Mark Mitchell <mark@codesourcery.com>.
4
1322177d 5This file is part of GCC.
c6d9a88c 6
1322177d
LB
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
c6d9a88c 11
1322177d
LB
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
c6d9a88c
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16
17You should have received a copy of the GNU General Public License
1322177d 18along with GCC; see the file COPYING. If not, write to the Free
366ccddb
KC
19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2002110-1301, USA.
c6d9a88c
MM
21
22*/
23
24/* This file contains definitions for language-independent
1eb68dca 25 parameters. The DEFPARAM macro takes 6 arguments:
c6d9a88c 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
9e7705cb 36 - The minimum acceptable value for the parameter.
1eb68dca 37
9e7705cb 38 - The maximum acceptable value for the parameter (if greater than
1eb68dca
KZ
39 the minimum).
40
1c4c47db 41 Be sure to add an entry to invoke.texi summarizing the parameter. */
c6d9a88c 42
31617ef1
DB
43/* The maximum number of fields in a variable with only implicit uses
44 for which structure aliasing will consider trying to track each
45 field. The default is 5. */
46DEFPARAM (PARAM_SALIAS_MAX_IMPLICIT_FIELDS,
47 "salias-max-implicit-fields",
48 "The maximum number of fields in a structure variable without direct structure accesses that GCC will attempt to track separately",
49 5, 0, 0)
a916f21d
RG
50
51/* The maximum number of array elements structure aliasing will decompose
52 an array for. The default is 4. */
53DEFPARAM (PARAM_SALIAS_MAX_ARRAY_ELEMENTS,
54 "salias-max-array-elements",
55 "The maximum number of elements in an array for wich we track its elements separately",
56 4, 0, 0)
57
61b58001
BE
58/* The maximum structure size at which the scalar replacement of
59 aggregates (SRA) pass will perform block copies. The default
60 value, 0, implies that GCC will select the most appropriate size
61 itself. */
62DEFPARAM (PARAM_SRA_MAX_STRUCTURE_SIZE,
63 "sra-max-structure-size",
460f84ed
RH
64 "The maximum structure size (in bytes) for which GCC will "
65 "use by-element copies",
66 0, 0, 0)
67
68/* The maximum number of structure fields which the SRA pass will
69 instantiate to avoid block copies. The default value, 0, implies
70 that GCC will select the appropriate value itself. */
71DEFPARAM (PARAM_SRA_MAX_STRUCTURE_COUNT,
72 "sra-max-structure-count",
73 "The maximum number of structure fields for which GCC will "
74 "use by-element copies",
e06c0feb 75 0, 0, 0)
61b58001
BE
76
77/* The ratio between instantiated fields and the complete structure
78 size. We say that if the ratio of the number of bytes in
79 instantiated fields to the number of bytes in the complete
460f84ed
RH
80 structure exceeds this parameter, or if the number of instantiated
81 fields to the total number of fields exceeds this parameter, then
82 block copies are not used. The default is 75%. */
61b58001
BE
83DEFPARAM (PARAM_SRA_FIELD_STRUCTURE_RATIO,
84 "sra-field-structure-ratio",
e06c0feb
NS
85 "The threshold ratio between instantiated fields and the total structure size",
86 75, 0, 100)
61b58001 87
a6227154
KG
88/* The single function inlining limit. This is the maximum size
89 of a function counted in internal gcc instructions (not in
90 real machine instructions) that is eligible for inlining
91 by the tree inliner.
e5c4f28a 92 The default value is 450.
a6227154 93 Only functions marked inline (or methods defined in the class
e5c4f28a 94 definition for C++) are affected by this.
a6227154
KG
95 There are more restrictions to inlining: If inlined functions
96 call other functions, the already inlined instructions are
97 counted and once the recursive inline limit (see
98 "max-inline-insns" parameter) is exceeded, the acceptable size
99 gets decreased. */
100DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
101 "max-inline-insns-single",
bc522472 102 "The maximum number of instructions in a single function eligible for inlining",
e5c4f28a 103 450, 0, 0)
a6227154 104
bc522472
KG
105/* The single function inlining limit for functions that are
106 inlined by virtue of -finline-functions (-O3).
107 This limit should be chosen to be below or equal to the limit
108 that is applied to functions marked inlined (or defined in the
109 class declaration in C++) given by the "max-inline-insns-single"
110 parameter.
e5c4f28a 111 The default value is 90. */
bc522472
KG
112DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
113 "max-inline-insns-auto",
114 "The maximum number of instructions when automatically inlining",
e5c4f28a 115 90, 0, 0)
bc522472 116
6de9cd9a
DN
117DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
118 "max-inline-insns-recursive",
119 "The maximum number of instructions inline function can grow to via recursive inlining",
e5c4f28a 120 450, 0, 0)
6de9cd9a
DN
121
122DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
123 "max-inline-insns-recursive-auto",
124 "The maximum number of instructions non-inline function can grow to via recursive inlining",
e5c4f28a 125 450, 0, 0)
6de9cd9a
DN
126
127DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
128 "max-inline-recursive-depth",
129 "The maximum depth of recursive inlining for inline functions",
e06c0feb 130 8, 0, 0)
6de9cd9a
DN
131
132DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
133 "max-inline-recursive-depth-auto",
134 "The maximum depth of recursive inlining for non-inline functions",
e06c0feb 135 8, 0, 0)
6de9cd9a 136
c5a4444c
JH
137DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
138 "min-inline-recursive-probability",
139 "Inline recursively only when the probability of call being executed exceeds the parameter",
140 10, 0, 0)
141
f37a4f14
RE
142/* Limit the number of expansions created by the variable expansion
143 optimization to avoid register pressure. */
144DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
145 "max-variable-expansions-in-unroller",
5fa534e3 146 "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling",
e06c0feb 147 1, 0, 0)
f37a4f14 148
0443f602
JO
149/* The maximum number of instructions to consider when looking for an
150 instruction to fill a delay slot. If more than this arbitrary
151 number of instructions is searched, the time savings from filling
152 the delay slot will be minimal so stop searching. Increasing
153 values mean more aggressive optimization, making the compile time
154 increase with probably small improvement in executable run time. */
155DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
156 "max-delay-slot-insn-search",
157 "The maximum number of instructions to consider to fill a delay slot",
e06c0feb 158 100, 0, 0)
0443f602 159
d5d063d7
JO
160/* When trying to fill delay slots, the maximum number of instructions
161 to consider when searching for a block with valid live register
162 information. Increasing this arbitrarily chosen value means more
163 aggressive optimization, increasing the compile time. This
164 parameter should be removed when the delay slot code is rewritten
165 to maintain the control-flow graph. */
166DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
167 "max-delay-slot-live-search",
168 "The maximum number of instructions to consider to find accurate live register information",
e06c0feb 169 333, 0, 0)
d5d063d7 170
4a121cc3 171/* This parameter limits the number of branch elements that the
ff7cc307 172 scheduler will track anti-dependencies through without resetting
4a121cc3 173 the tracking mechanism. Large functions with few calls or barriers
ff7cc307 174 can generate lists containing many 1000's of dependencies. Generally
4a121cc3
AM
175 the compiler either uses all available memory, or runs for far too long. */
176DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
177 "max-pending-list-length",
178 "The maximum length of scheduling's pending operations list",
e06c0feb 179 32, 0, 0)
4a121cc3 180
b58b1157
JH
181DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
182 "large-function-insns",
183 "The size of function body to be considered large",
e5c4f28a 184 2700, 0, 0)
b58b1157
JH
185DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
186 "large-function-growth",
2cc98056 187 "Maximal growth due to inlining of large function (in percent)",
e06c0feb 188 100, 0, 0)
b4f32d07
JH
189DEFPARAM(PARAM_LARGE_UNIT_INSNS,
190 "large-unit-insns",
191 "The size of translation unit to be considered large",
192 10000, 0, 0)
b58b1157
JH
193DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
194 "inline-unit-growth",
2cc98056 195 "how much can given compilation unit grow because of the inlining (in percent)",
e06c0feb 196 50, 0, 0)
e5c4f28a
RG
197DEFPARAM(PARAM_INLINE_CALL_COST,
198 "inline-call-cost",
2e0ea515 199 "expense of call operation relative to ordinary arithmetic operations",
e5c4f28a 200 16, 0, 0)
b58b1157 201
f1fa37ff
MM
202/* The GCSE optimization will be disabled if it would require
203 significantly more memory than this value. */
204DEFPARAM(PARAM_MAX_GCSE_MEMORY,
205 "max-gcse-memory",
206 "The maximum amount of memory to be allocated by GCSE",
e06c0feb 207 50 * 1024 * 1024, 0, 0)
991b6592 208/* The number of repetitions of copy/const prop and PRE to run. */
740f35a0
DB
209DEFPARAM(PARAM_MAX_GCSE_PASSES,
210 "max-gcse-passes",
211 "The maximum number of passes to make when doing GCSE",
e06c0feb 212 1, 1, 0)
f9957958
MH
213/* This is the threshold ratio when to perform partial redundancy
214 elimination after reload. We perform partial redundancy elimination
215 when the following holds:
216 (Redundant load execution count)
217 ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
218 (Added loads execution count) */
219DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
220 "gcse-after-reload-partial-fraction",
c85ce869 221 "The threshold ratio for performing partial redundancy elimination after reload",
e06c0feb 222 3, 0, 0)
f9957958
MH
223/* This is the threshold ratio of the critical edges execution count compared to
224 the redundant loads execution count that permits performing the load
225 redundancy elimination in gcse after reload. */
226DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
227 "gcse-after-reload-critical-fraction",
c85ce869 228 "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload",
e06c0feb 229 10, 0, 0)
03e9dbc9 230/* This parameter limits the number of insns in a loop that will be unrolled,
701ad47e
JH
231 and by how much the loop is unrolled.
232
233 This limit should be at most half of the peeling limits: loop unroller
234 decides to not unroll loops that iterate fewer than 2*number of allowed
a1105617 235 unrollings and thus we would have loops that are neither peeled or unrolled
701ad47e 236 otherwise. */
03e9dbc9
MM
237DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
238 "max-unrolled-insns",
239 "The maximum number of instructions to consider to unroll in a loop",
e06c0feb 240 200, 0, 0)
b17d5d7c
ZD
241/* This parameter limits how many times the loop is unrolled depending
242 on number of insns really executed in each iteration. */
243DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
244 "max-average-unrolled-insns",
245 "The maximum number of instructions to consider to unroll in a loop on average",
e06c0feb 246 80, 0, 0)
b17d5d7c
ZD
247/* The maximum number of unrollings of a single loop. */
248DEFPARAM(PARAM_MAX_UNROLL_TIMES,
249 "max-unroll-times",
250 "The maximum number of unrollings of a single loop",
e06c0feb 251 8, 0, 0)
b17d5d7c
ZD
252/* The maximum number of insns of a peeled loop. */
253DEFPARAM(PARAM_MAX_PEELED_INSNS,
254 "max-peeled-insns",
255 "The maximum number of insns of a peeled loop",
e06c0feb 256 400, 0, 0)
b17d5d7c
ZD
257/* The maximum number of peelings of a single loop. */
258DEFPARAM(PARAM_MAX_PEEL_TIMES,
259 "max-peel-times",
260 "The maximum number of peelings of a single loop",
e06c0feb 261 16, 0, 0)
b17d5d7c
ZD
262/* The maximum number of insns of a peeled loop. */
263DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
264 "max-completely-peeled-insns",
265 "The maximum number of insns of a completely peeled loop",
e06c0feb 266 400, 0, 0)
b17d5d7c
ZD
267/* The maximum number of peelings of a single loop that is peeled completely. */
268DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
269 "max-completely-peel-times",
270 "The maximum number of peelings of a single loop that is peeled completely",
e06c0feb 271 16, 0, 0)
b17d5d7c
ZD
272/* The maximum number of insns of a peeled loop that rolls only once. */
273DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
274 "max-once-peeled-insns",
275 "The maximum number of insns of a peeled loop that rolls only once",
e06c0feb 276 400, 0, 0)
194734e9 277
617b465c
ZD
278/* The maximum number of insns of an unswitched loop. */
279DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
280 "max-unswitch-insns",
281 "The maximum number of insns of an unswitched loop",
e06c0feb 282 50, 0, 0)
617b465c
ZD
283/* The maximum level of recursion in unswitch_single_loop. */
284DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
285 "max-unswitch-level",
286 "The maximum number of unswitchings in a single loop",
e06c0feb 287 3, 0, 0)
617b465c 288
e9eb809d
ZD
289/* The maximum number of iterations of a loop the brute force algorithm
290 for analysis of # of iterations of the loop tries to evaluate. */
291DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
292 "max-iterations-to-track",
e06c0feb
NS
293 "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates",
294 1000, 0, 0)
e9eb809d 295
e5626198
AZ
296DEFPARAM(PARAM_MAX_SMS_LOOP_NUMBER,
297 "max-sms-loop-number",
e06c0feb
NS
298 "Maximum number of loops to perform swing modulo scheduling on (mainly for debugging)",
299 -1, -1, -1)
300
e5626198
AZ
301/* This parameter is used to tune SMS MAX II calculations. */
302DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
303 "sms-max-ii-factor",
e06c0feb
NS
304 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop",
305 100, 0, 0)
e5626198
AZ
306DEFPARAM(PARAM_SMS_DFA_HISTORY,
307 "sms-dfa-history",
5fa534e3 308 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA",
e06c0feb 309 0, 0, 0)
e5626198
AZ
310DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
311 "sms-loop-average-count-threshold",
e06c0feb
NS
312 "A threshold on the average loop count considered by the swing modulo scheduler",
313 0, 0, 0)
e5626198 314
194734e9
JH
315DEFPARAM(HOT_BB_COUNT_FRACTION,
316 "hot-bb-count-fraction",
e06c0feb
NS
317 "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot",
318 10000, 0, 0)
194734e9
JH
319DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
320 "hot-bb-frequency-fraction",
e06c0feb
NS
321 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot",
322 1000, 0, 0)
95b9a3a5
JH
323
324/* For guessed profiles, the loops having unknown number of iterations
325 are predicted to iterate relatively few (10) times at average.
326 For functions containing one loop with large known number of iterations
327 and other loops having unbounded loops we would end up predicting all
c83eecad 328 the other loops cold that is not usually the case. So we need to artificially
95b9a3a5
JH
329 flatten the profile.
330
6416ae7f 331 We need to cut the maximal predicted iterations to large enough iterations
95b9a3a5
JH
332 so the loop appears important, but safely within HOT_BB_COUNT_FRACTION
333 range. */
334
335DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
336 "max-predicted-iterations",
337 "The maximum number of loop iterations we predict statically",
338 100, 0, 0)
5c856b23
JH
339DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
340 "tracer-dynamic-coverage-feedback",
e06c0feb
NS
341 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available",
342 95, 0, 100)
5c856b23
JH
343DEFPARAM(TRACER_DYNAMIC_COVERAGE,
344 "tracer-dynamic-coverage",
e06c0feb
NS
345 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available",
346 75, 0, 100)
5c856b23
JH
347DEFPARAM(TRACER_MAX_CODE_GROWTH,
348 "tracer-max-code-growth",
2cc98056 349 "Maximal code growth caused by tail duplication (in percent)",
e06c0feb 350 100, 0, 0)
5c856b23
JH
351DEFPARAM(TRACER_MIN_BRANCH_RATIO,
352 "tracer-min-branch-ratio",
e06c0feb
NS
353 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)",
354 10, 0, 100)
5c856b23
JH
355DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
356 "tracer-min-branch-probability-feedback",
e06c0feb
NS
357 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available",
358 80, 0, 100)
5c856b23
JH
359DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
360 "tracer-min-branch-probability",
e06c0feb
NS
361 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available",
362 50, 0, 100)
3788cc17 363
5f24e0dc
RH
364/* The maximum number of incoming edges to consider for crossjumping. */
365DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
366 "max-crossjump-edges",
367 "The maximum number of incoming edges to consider for crossjumping",
e06c0feb 368 100, 0, 0)
5f24e0dc 369
12183e0f
PH
370/* The minimum number of matching instructions to consider for crossjumping. */
371DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
372 "min-crossjump-insns",
373 "The minimum number of matching instructions to consider for crossjumping",
e06c0feb 374 5, 0, 0)
12183e0f 375
f935b9e0
DE
376/* The maximum number expansion factor when copying basic blocks. */
377DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
378 "max-grow-copy-bb-insns",
379 "The maximum expansion factor when copying basic blocks",
380 8, 0, 0)
381
bbcb0c05
SB
382/* The maximum number of insns to duplicate when unfactoring computed gotos. */
383DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
384 "max-goto-duplication-insns",
385 "The maximum number of insns to duplicate when unfactoring computed gotos",
386 8, 0, 0)
387
9bf8cfbf
ZD
388/* The maximum length of path considered in cse. */
389DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
390 "max-cse-path-length",
2cc98056 391 "The maximum length of path considered in cse",
e06c0feb 392 10, 0, 0)
95b9a3a5
JH
393DEFPARAM(PARAM_MAX_CSE_INSNS,
394 "max-flow-memory-locations",
395 "The maximum instructions CSE process before flushing",
396 1000, 0, 0)
9bf8cfbf 397
a7e5372d
ZD
398/* The cost of expression in loop invariant motion that is considered
399 expensive. */
400DEFPARAM(PARAM_LIM_EXPENSIVE,
401 "lim-expensive",
402 "The minimum cost of an expensive expression in the loop invariant motion",
e06c0feb 403 20, 0, 0)
a7e5372d 404
8b11a64c
ZD
405/* Bound on number of candidates for induction variables below that
406 all candidates are considered for each use in induction variable
407 optimizations. */
408
409DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
410 "iv-consider-all-candidates-bound",
411 "Bound on number of candidates below that all candidates are considered in iv optimizations",
e06c0feb 412 30, 0, 0)
8b11a64c
ZD
413
414/* The induction variable optimizations give up on loops that contain more
415 induction variable uses. */
416
417DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
418 "iv-max-considered-uses",
419 "Bound on number of iv uses in loop optimized in iv optimizations",
e06c0feb 420 250, 0, 0)
8b11a64c 421
36f5ada1
ZD
422/* If there are at most this number of ivs in the set, try removing unnecessary
423 ivs from the set always. */
424
425DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
426 "iv-always-prune-cand-set-bound",
427 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization",
428 10, 0, 0)
429
2412d35c
SP
430DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
431 "scev-max-expr-size",
432 "Bound on size of expressions used in the scalar evolutions analyzer",
433 20, 0, 0)
434
c12cc930
KB
435DEFPARAM(PARAM_VECT_MAX_VERSION_CHECKS,
436 "vect-max-version-checks",
437 "Bound on number of runtime checks inserted by the vectorizer's loop versioning",
438 6, 0, 0)
439
6de9cd9a
DN
440/* The product of the next two is used to decide whether or not to
441 use .GLOBAL_VAR. See tree-dfa.c. */
442DEFPARAM(PARAM_GLOBAL_VAR_THRESHOLD,
443 "global-var-threshold",
444 "Given N calls and V call-clobbered vars in a function. Use .GLOBAL_VAR if NxV is larger than this limit",
e06c0feb 445 500000, 0, 0)
6de9cd9a 446
c65ecebc
JH
447DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
448 "max-cselib-memory-locations",
449 "The maximum memory locations recorded by cselib",
e06c0feb 450 500, 0, 0)
95b9a3a5
JH
451DEFPARAM(PARAM_MAX_FLOW_MEMORY_LOCATIONS,
452 "max-flow-memory-locations",
453 "The maximum memory locations recorded by flow",
454 100, 0, 0)
c65ecebc 455
3788cc17
ZW
456#ifdef ENABLE_GC_ALWAYS_COLLECT
457# define GGC_MIN_EXPAND_DEFAULT 0
737c38d1 458# define GGC_MIN_HEAPSIZE_DEFAULT 0
3788cc17
ZW
459#else
460# define GGC_MIN_EXPAND_DEFAULT 30
737c38d1 461# define GGC_MIN_HEAPSIZE_DEFAULT 4096
3788cc17
ZW
462#endif
463
464DEFPARAM(GGC_MIN_EXPAND,
465 "ggc-min-expand",
e06c0feb
NS
466 "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap",
467 GGC_MIN_EXPAND_DEFAULT, 0, 0)
3788cc17 468
3788cc17
ZW
469DEFPARAM(GGC_MIN_HEAPSIZE,
470 "ggc-min-heapsize",
2cc98056 471 "Minimum heap size before we start collecting garbage, in kilobytes",
e06c0feb 472 GGC_MIN_HEAPSIZE_DEFAULT, 0, 0)
737c38d1
GK
473
474#undef GGC_MIN_EXPAND_DEFAULT
475#undef GGC_MIN_HEAPSIZE_DEFAULT
3788cc17 476
0bcf8261
JH
477DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
478 "max-reload-search-insns",
479 "The maximum number of instructions to search backward when looking for equivalent reload",
e06c0feb 480 100, 0, 0)
0bcf8261 481
6de9cd9a
DN
482DEFPARAM(PARAM_MAX_ALIASED_VOPS,
483 "max-aliased-vops",
c85ce869 484 "The maximum number of virtual operands allowed to represent aliases before triggering alias grouping",
e06c0feb 485 500, 0, 0)
6de9cd9a 486
f72c6b56
DE
487DEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS,
488 "max-sched-region-blocks",
489 "The maximum number of blocks in a region to be considered for interblock scheduling",
e06c0feb 490 10, 0, 0)
f72c6b56
DE
491
492DEFPARAM(PARAM_MAX_SCHED_REGION_INSNS,
493 "max-sched-region-insns",
494 "The maximum number of insns in a region to be considered for interblock scheduling",
e06c0feb 495 100, 0, 0)
f72c6b56 496
6f48c21a
PS
497DEFPARAM(PARAM_MIN_SPEC_PROB,
498 "min-spec-prob",
499 "The minimum probability of reaching a source block for interblock speculative scheduling",
500 40, 0, 0)
501
49c3b9a8
JJ
502DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
503 "max-last-value-rtl",
504 "The maximum number of RTL nodes that can be recorded as combiner's last value",
505 10000, 0, 0)
506
89b0433e
NS
507/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
508 {signed,unsigned} integral types. This determines N.
509 Experimentation shows 256 to be a good value. */
510DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
511 "integer-share-limit",
512 "The upper bound for sharing integer constants",
e06c0feb 513 256, 2, 2)
89b0433e 514
84d65814
DN
515/* Incremental SSA updates for virtual operands may be very slow if
516 there is a large number of mappings to process. In those cases, it
517 is faster to rewrite the virtual symbols from scratch as if they
518 had been recently introduced. This heuristic cannot be applied to
519 SSA mappings for real SSA names, only symbols kept in FUD chains.
520
521 PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual
522 mappings that should be registered to trigger the heuristic.
523
524 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between
525 mappings and symbols. If the number of virtual mappings is
526 PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of
527 virtual symbols to be updated, then the updater switches to a full
528 update for those symbols. */
529DEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS,
530 "min-virtual-mappings",
531 "Minimum number of virtual mappings to consider switching to full virtual renames",
532 100, 0, 0)
533
534DEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO,
535 "virtual-mappings-ratio",
536 "Ratio between virtual mappings and virtual symbols to do full virtual renames",
537 3, 0, 0)
538
7d69de61
RH
539DEFPARAM (PARAM_SSP_BUFFER_SIZE,
540 "ssp-buffer-size",
541 "The lower bound for a buffer to be considered for stack smashing protection",
542 8, 1, 0)
543
43f31be5
JL
544/* When we thread through a block we have to make copies of the
545 statements within the block. Clearly for large blocks the code
546 duplication is bad.
547
548 PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number
549 of statements and PHI nodes allowed in a block which is going to
550 be duplicated for thread jumping purposes.
551
552 Some simple analysis showed that more than 99% of the jump
553 threading opportunities are for blocks with less than 15
554 statements. So we can get the benefits of jump threading
555 without excessive code bloat for pathological cases with the
556 throttle set at 15 statements. */
557DEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS,
558 "max-jump-thread-duplication-stmts",
559 "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps",
560 15, 0, 0)
98035a75
DB
561
562/* This is the maximum number of fields a variable may have before the pointer analysis machinery
563 will stop trying to treat it in a field-sensitive manner.
564 There are programs out there with thousands of fields per structure, and handling them
565 field-sensitively is not worth the cost. */
566DEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE,
567 "max-fields-for-field-sensitive",
568 "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable",
569 100, 0, 0)
c6d9a88c
MM
570/*
571Local variables:
572mode:c
573End: */