]> git.ipfire.org Git - thirdparty/gcc.git/blame - gcc/params.def
i386.c (ix86_rtx_costs): Drop NEG from sub for FMA.
[thirdparty/gcc.git] / gcc / params.def
CommitLineData
c6d9a88c 1/* params.def - Run-time parameters.
29fa95ed
JL
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
3 2011
3d8864c0 4 Free Software Foundation, Inc.
c6d9a88c
MM
5 Written by Mark Mitchell <mark@codesourcery.com>.
6
1322177d 7This file is part of GCC.
c6d9a88c 8
1322177d
LB
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
1322177d
LB
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.
c6d9a88c
MM
18
19You should have received a copy of the GNU General Public License
9dcd6f09
NC
20along with GCC; see the file COPYING3. If not see
21<http://www.gnu.org/licenses/>. */
c6d9a88c
MM
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
c6d9a88c
MM
29 command-line option `--param <name>=<value>'.
30
31 - A help string explaining how the parameter is used.
32
1c4c47db
JO
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
1eb68dca
KZ
38 the minimum).
39
1c4c47db 40 Be sure to add an entry to invoke.texi summarizing the parameter. */
c6d9a88c 41
3a4fd356
JH
42/* When branch is predicted to be taken with probability lower than this
43 threshold (in percent), then it is considered well predictable. */
44DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME,
45 "predictable-branch-outcome",
67018619 46 "Maximal estimated outcome of branch considered predictable",
3a4fd356
JH
47 2, 0, 50)
48
a6227154
KG
49/* The single function inlining limit. This is the maximum size
50 of a function counted in internal gcc instructions (not in
51 real machine instructions) that is eligible for inlining
52 by the tree inliner.
e5c4f28a 53 The default value is 450.
a6227154 54 Only functions marked inline (or methods defined in the class
e5c4f28a 55 definition for C++) are affected by this.
a6227154
KG
56 There are more restrictions to inlining: If inlined functions
57 call other functions, the already inlined instructions are
b8698a0f 58 counted and once the recursive inline limit (see
a6227154
KG
59 "max-inline-insns" parameter) is exceeded, the acceptable size
60 gets decreased. */
61DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
62 "max-inline-insns-single",
bc522472 63 "The maximum number of instructions in a single function eligible for inlining",
172d54e0 64 400, 0, 0)
a6227154 65
bc522472
KG
66/* The single function inlining limit for functions that are
67 inlined by virtue of -finline-functions (-O3).
68 This limit should be chosen to be below or equal to the limit
69 that is applied to functions marked inlined (or defined in the
70 class declaration in C++) given by the "max-inline-insns-single"
71 parameter.
7802ca7c 72 The default value is 40. */
bc522472
KG
73DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
74 "max-inline-insns-auto",
75 "The maximum number of instructions when automatically inlining",
7802ca7c 76 40, 0, 0)
bc522472 77
6de9cd9a
DN
78DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
79 "max-inline-insns-recursive",
80 "The maximum number of instructions inline function can grow to via recursive inlining",
172d54e0 81 450, 0, 0)
6de9cd9a
DN
82
83DEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
84 "max-inline-insns-recursive-auto",
85 "The maximum number of instructions non-inline function can grow to via recursive inlining",
172d54e0 86 450, 0, 0)
6de9cd9a
DN
87
88DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
89 "max-inline-recursive-depth",
90 "The maximum depth of recursive inlining for inline functions",
e06c0feb 91 8, 0, 0)
6de9cd9a
DN
92
93DEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
94 "max-inline-recursive-depth-auto",
95 "The maximum depth of recursive inlining for non-inline functions",
e06c0feb 96 8, 0, 0)
6de9cd9a 97
c5a4444c
JH
98DEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
99 "min-inline-recursive-probability",
100 "Inline recursively only when the probability of call being executed exceeds the parameter",
101 10, 0, 0)
102
796bda22
JH
103/* Limit of iterations of early inliner. This basically bounds number of
104 nested indirect calls early inliner can resolve. Deeper chains are still
105 handled by late inlining. */
106DEFPARAM (PARAM_EARLY_INLINER_MAX_ITERATIONS,
107 "max-early-inliner-iterations",
108 "The maximum number of nested indirect inlining performed by early inliner",
109 10, 0, 0)
110
c5d0600d
JH
111/* Limit on probability of entry BB. */
112DEFPARAM (PARAM_COMDAT_SHARING_PROBABILITY,
113 "comdat-sharing-probability",
114 "Probability that COMDAT function will be shared with different compilatoin unit",
115 20, 0, 0)
116
3e485f62
JH
117/* Limit on probability of entry BB. */
118DEFPARAM (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY,
119 "partial-inlining-entry-probability",
120 "Maximum probability of the entry BB of split region (in percent relative to entry BB of the function) to make partial inlining happen",
121 70, 0, 0)
122
f37a4f14
RE
123/* Limit the number of expansions created by the variable expansion
124 optimization to avoid register pressure. */
125DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
126 "max-variable-expansions-in-unroller",
5fa534e3 127 "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling",
e06c0feb 128 1, 0, 0)
b8698a0f 129
acdc40df
DN
130/* Limit loop autovectorization to loops with large enough iteration count. */
131DEFPARAM (PARAM_MIN_VECT_LOOP_BOUND,
132 "min-vect-loop-bound",
133 "If -ftree-vectorize is used, the minimal loop bound of a loop to be considered for vectorization",
8d888559 134 1, 1, 0)
acdc40df 135
0443f602
JO
136/* The maximum number of instructions to consider when looking for an
137 instruction to fill a delay slot. If more than this arbitrary
138 number of instructions is searched, the time savings from filling
139 the delay slot will be minimal so stop searching. Increasing
140 values mean more aggressive optimization, making the compile time
141 increase with probably small improvement in executable run time. */
142DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
143 "max-delay-slot-insn-search",
144 "The maximum number of instructions to consider to fill a delay slot",
e06c0feb 145 100, 0, 0)
0443f602 146
d5d063d7
JO
147/* When trying to fill delay slots, the maximum number of instructions
148 to consider when searching for a block with valid live register
149 information. Increasing this arbitrarily chosen value means more
150 aggressive optimization, increasing the compile time. This
151 parameter should be removed when the delay slot code is rewritten
152 to maintain the control-flow graph. */
153DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
154 "max-delay-slot-live-search",
155 "The maximum number of instructions to consider to find accurate live register information",
e06c0feb 156 333, 0, 0)
d5d063d7 157
b8698a0f 158/* This parameter limits the number of branch elements that the
ff7cc307 159 scheduler will track anti-dependencies through without resetting
b8698a0f
L
160 the tracking mechanism. Large functions with few calls or barriers
161 can generate lists containing many 1000's of dependencies. Generally
4a121cc3
AM
162 the compiler either uses all available memory, or runs for far too long. */
163DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
164 "max-pending-list-length",
165 "The maximum length of scheduling's pending operations list",
e06c0feb 166 32, 0, 0)
4a121cc3 167
b58b1157
JH
168DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
169 "large-function-insns",
170 "The size of function body to be considered large",
e5c4f28a 171 2700, 0, 0)
b58b1157
JH
172DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
173 "large-function-growth",
2cc98056 174 "Maximal growth due to inlining of large function (in percent)",
e06c0feb 175 100, 0, 0)
b4f32d07
JH
176DEFPARAM(PARAM_LARGE_UNIT_INSNS,
177 "large-unit-insns",
178 "The size of translation unit to be considered large",
179 10000, 0, 0)
b58b1157
JH
180DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
181 "inline-unit-growth",
7b98c16f 182 "How much can given compilation unit grow because of the inlining (in percent)",
d562c668 183 30, 0, 0)
5e45130d
JH
184DEFPARAM(PARAM_IPCP_UNIT_GROWTH,
185 "ipcp-unit-growth",
7b98c16f 186 "How much can given compilation unit grow because of the interprocedural constant propagation (in percent)",
5e45130d 187 10, 0, 0)
85057983
JH
188DEFPARAM(PARAM_EARLY_INLINING_INSNS,
189 "early-inlining-insns",
7b98c16f 190 "Maximal estimated growth of function body caused by early inlining of single call",
632b4f8e 191 11, 0, 0)
ff28a94d
JH
192DEFPARAM(PARAM_LARGE_STACK_FRAME,
193 "large-stack-frame",
194 "The size of stack frame to be considered large",
195 256, 0, 0)
196DEFPARAM(PARAM_STACK_FRAME_GROWTH,
197 "large-stack-frame-growth",
198 "Maximal stack frame growth due to inlining (in percent)",
199 1000, 0, 0)
b58b1157 200
f1fa37ff
MM
201/* The GCSE optimization will be disabled if it would require
202 significantly more memory than this value. */
203DEFPARAM(PARAM_MAX_GCSE_MEMORY,
204 "max-gcse-memory",
205 "The maximum amount of memory to be allocated by GCSE",
e06c0feb 206 50 * 1024 * 1024, 0, 0)
3906a4a1 207
29fa95ed
JL
208/* The GCSE optimization of an expression will avoided if the ratio of
209 insertions to deletions is greater than this value. */
210DEFPARAM(PARAM_MAX_GCSE_INSERTION_RATIO,
211 "max-gcse-insertion-ratio",
212 "The maximum ratio of insertions to deletions of expressions in GCSE",
213 20, 0, 0)
214
f9957958
MH
215/* This is the threshold ratio when to perform partial redundancy
216 elimination after reload. We perform partial redundancy elimination
217 when the following holds:
218 (Redundant load execution count)
219 ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
220 (Added loads execution count) */
221DEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
222 "gcse-after-reload-partial-fraction",
c85ce869 223 "The threshold ratio for performing partial redundancy elimination after reload",
e06c0feb 224 3, 0, 0)
f9957958
MH
225/* This is the threshold ratio of the critical edges execution count compared to
226 the redundant loads execution count that permits performing the load
227 redundancy elimination in gcse after reload. */
228DEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
229 "gcse-after-reload-critical-fraction",
c85ce869 230 "The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload",
e06c0feb 231 10, 0, 0)
20160347
MK
232
233/* GCSE will use GCSE_COST_DISTANCE_RATION as a scaling factor
234 to calculate maximum distance for which an expression is allowed to move
235 from its rtx_cost. */
236DEFPARAM(PARAM_GCSE_COST_DISTANCE_RATIO,
237 "gcse-cost-distance-ratio",
238 "Scaling factor in calculation of maximum distance an expression can be moved by GCSE optimizations",
239 10, 0, 0)
240/* GCSE won't restrict distance for which an expression with rtx_cost greater
241 than COSTS_N_INSN(GCSE_UNRESTRICTED_COST) is allowed to move. */
242DEFPARAM(PARAM_GCSE_UNRESTRICTED_COST,
243 "gcse-unrestricted-cost",
244 "Cost at which GCSE optimizations will not constraint the distance an expression can travel",
245 3, 0, 0)
246
cad9aa15
MK
247/* How deep from a given basic block the dominator tree should be searched
248 for expressions to hoist to the block. The value of 0 will avoid limiting
249 the search. */
250DEFPARAM(PARAM_MAX_HOIST_DEPTH,
251 "max-hoist-depth",
252 "Maximum depth of search in the dominator tree for expressions to hoist",
253 30, 0, 0)
254
03e9dbc9 255/* This parameter limits the number of insns in a loop that will be unrolled,
701ad47e 256 and by how much the loop is unrolled.
b8698a0f 257
701ad47e
JH
258 This limit should be at most half of the peeling limits: loop unroller
259 decides to not unroll loops that iterate fewer than 2*number of allowed
a1105617 260 unrollings and thus we would have loops that are neither peeled or unrolled
701ad47e 261 otherwise. */
03e9dbc9
MM
262DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
263 "max-unrolled-insns",
264 "The maximum number of instructions to consider to unroll in a loop",
e06c0feb 265 200, 0, 0)
b17d5d7c
ZD
266/* This parameter limits how many times the loop is unrolled depending
267 on number of insns really executed in each iteration. */
268DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
269 "max-average-unrolled-insns",
270 "The maximum number of instructions to consider to unroll in a loop on average",
e06c0feb 271 80, 0, 0)
b17d5d7c
ZD
272/* The maximum number of unrollings of a single loop. */
273DEFPARAM(PARAM_MAX_UNROLL_TIMES,
274 "max-unroll-times",
275 "The maximum number of unrollings of a single loop",
e06c0feb 276 8, 0, 0)
b17d5d7c
ZD
277/* The maximum number of insns of a peeled loop. */
278DEFPARAM(PARAM_MAX_PEELED_INSNS,
279 "max-peeled-insns",
280 "The maximum number of insns of a peeled loop",
e06c0feb 281 400, 0, 0)
b17d5d7c
ZD
282/* The maximum number of peelings of a single loop. */
283DEFPARAM(PARAM_MAX_PEEL_TIMES,
284 "max-peel-times",
285 "The maximum number of peelings of a single loop",
e06c0feb 286 16, 0, 0)
b17d5d7c
ZD
287/* The maximum number of insns of a peeled loop. */
288DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
289 "max-completely-peeled-insns",
290 "The maximum number of insns of a completely peeled loop",
e06c0feb 291 400, 0, 0)
b17d5d7c
ZD
292/* The maximum number of peelings of a single loop that is peeled completely. */
293DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
294 "max-completely-peel-times",
295 "The maximum number of peelings of a single loop that is peeled completely",
e06c0feb 296 16, 0, 0)
b17d5d7c
ZD
297/* The maximum number of insns of a peeled loop that rolls only once. */
298DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
299 "max-once-peeled-insns",
300 "The maximum number of insns of a peeled loop that rolls only once",
e06c0feb 301 400, 0, 0)
30bc1dca
RG
302/* The maximum depth of a loop nest we completely peel. */
303DEFPARAM(PARAM_MAX_UNROLL_ITERATIONS,
304 "max-completely-peel-loop-nest-depth",
305 "The maximum depth of a loop nest we completely peel",
306 8, 0, 0)
194734e9 307
617b465c
ZD
308/* The maximum number of insns of an unswitched loop. */
309DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
310 "max-unswitch-insns",
311 "The maximum number of insns of an unswitched loop",
e06c0feb 312 50, 0, 0)
617b465c
ZD
313/* The maximum level of recursion in unswitch_single_loop. */
314DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
315 "max-unswitch-level",
316 "The maximum number of unswitchings in a single loop",
e06c0feb 317 3, 0, 0)
617b465c 318
e9eb809d
ZD
319/* The maximum number of iterations of a loop the brute force algorithm
320 for analysis of # of iterations of the loop tries to evaluate. */
321DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
322 "max-iterations-to-track",
e06c0feb
NS
323 "Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates",
324 1000, 0, 0)
45b9a14b
BS
325/* A cutoff to avoid costly computations of the number of iterations in
326 the doloop transformation. */
327DEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST,
328 "max-iterations-computation-cost",
329 "Bound on the cost of an expression to compute the number of iterations",
330 10, 0, 0)
e9eb809d 331
e5626198
AZ
332/* This parameter is used to tune SMS MAX II calculations. */
333DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
334 "sms-max-ii-factor",
e06c0feb
NS
335 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop",
336 100, 0, 0)
3e2fdd24
RE
337/* The minimum value of stage count that swing modulo scheduler will generate. */
338DEFPARAM(PARAM_SMS_MIN_SC,
339 "sms-min-sc",
340 "The minimum value of stage count that swing modulo scheduler will generate.",
341 2, 1, 1)
e5626198
AZ
342DEFPARAM(PARAM_SMS_DFA_HISTORY,
343 "sms-dfa-history",
5fa534e3 344 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA",
e06c0feb 345 0, 0, 0)
e5626198
AZ
346DEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
347 "sms-loop-average-count-threshold",
e06c0feb
NS
348 "A threshold on the average loop count considered by the swing modulo scheduler",
349 0, 0, 0)
e5626198 350
194734e9
JH
351DEFPARAM(HOT_BB_COUNT_FRACTION,
352 "hot-bb-count-fraction",
e06c0feb
NS
353 "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot",
354 10000, 0, 0)
194734e9
JH
355DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
356 "hot-bb-frequency-fraction",
e06c0feb
NS
357 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot",
358 1000, 0, 0)
95b9a3a5 359
edbed3d3
JH
360DEFPARAM (PARAM_ALIGN_THRESHOLD,
361 "align-threshold",
362 "Select fraction of the maximal frequency of executions of basic block in function given basic block get alignment",
363 100, 0, 0)
364
365DEFPARAM (PARAM_ALIGN_LOOP_ITERATIONS,
366 "align-loop-iterations",
367 "Loops iterating at least selected number of iterations will get loop alignement.",
368 4, 0, 0)
369
95b9a3a5
JH
370/* For guessed profiles, the loops having unknown number of iterations
371 are predicted to iterate relatively few (10) times at average.
372 For functions containing one loop with large known number of iterations
373 and other loops having unbounded loops we would end up predicting all
c83eecad 374 the other loops cold that is not usually the case. So we need to artificially
b8698a0f 375 flatten the profile.
95b9a3a5 376
6416ae7f 377 We need to cut the maximal predicted iterations to large enough iterations
95b9a3a5
JH
378 so the loop appears important, but safely within HOT_BB_COUNT_FRACTION
379 range. */
380
381DEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
382 "max-predicted-iterations",
383 "The maximum number of loop iterations we predict statically",
384 100, 0, 0)
5c856b23
JH
385DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
386 "tracer-dynamic-coverage-feedback",
e06c0feb
NS
387 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available",
388 95, 0, 100)
5c856b23
JH
389DEFPARAM(TRACER_DYNAMIC_COVERAGE,
390 "tracer-dynamic-coverage",
e06c0feb
NS
391 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available",
392 75, 0, 100)
5c856b23
JH
393DEFPARAM(TRACER_MAX_CODE_GROWTH,
394 "tracer-max-code-growth",
2cc98056 395 "Maximal code growth caused by tail duplication (in percent)",
e06c0feb 396 100, 0, 0)
5c856b23
JH
397DEFPARAM(TRACER_MIN_BRANCH_RATIO,
398 "tracer-min-branch-ratio",
e06c0feb
NS
399 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)",
400 10, 0, 100)
5c856b23
JH
401DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
402 "tracer-min-branch-probability-feedback",
e06c0feb
NS
403 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available",
404 80, 0, 100)
5c856b23
JH
405DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
406 "tracer-min-branch-probability",
e06c0feb
NS
407 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available",
408 50, 0, 100)
3788cc17 409
5f24e0dc
RH
410/* The maximum number of incoming edges to consider for crossjumping. */
411DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
412 "max-crossjump-edges",
413 "The maximum number of incoming edges to consider for crossjumping",
e06c0feb 414 100, 0, 0)
5f24e0dc 415
12183e0f
PH
416/* The minimum number of matching instructions to consider for crossjumping. */
417DEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
418 "min-crossjump-insns",
419 "The minimum number of matching instructions to consider for crossjumping",
e06c0feb 420 5, 0, 0)
12183e0f 421
f935b9e0
DE
422/* The maximum number expansion factor when copying basic blocks. */
423DEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
424 "max-grow-copy-bb-insns",
425 "The maximum expansion factor when copying basic blocks",
426 8, 0, 0)
427
bbcb0c05
SB
428/* The maximum number of insns to duplicate when unfactoring computed gotos. */
429DEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
430 "max-goto-duplication-insns",
431 "The maximum number of insns to duplicate when unfactoring computed gotos",
432 8, 0, 0)
433
9bf8cfbf
ZD
434/* The maximum length of path considered in cse. */
435DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
436 "max-cse-path-length",
2cc98056 437 "The maximum length of path considered in cse",
e06c0feb 438 10, 0, 0)
95b9a3a5 439DEFPARAM(PARAM_MAX_CSE_INSNS,
921b02cd 440 "max-cse-insns",
95b9a3a5
JH
441 "The maximum instructions CSE process before flushing",
442 1000, 0, 0)
9bf8cfbf 443
a7e5372d
ZD
444/* The cost of expression in loop invariant motion that is considered
445 expensive. */
446DEFPARAM(PARAM_LIM_EXPENSIVE,
447 "lim-expensive",
448 "The minimum cost of an expensive expression in the loop invariant motion",
e06c0feb 449 20, 0, 0)
a7e5372d 450
8b11a64c
ZD
451/* Bound on number of candidates for induction variables below that
452 all candidates are considered for each use in induction variable
453 optimizations. */
454
455DEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
456 "iv-consider-all-candidates-bound",
457 "Bound on number of candidates below that all candidates are considered in iv optimizations",
e06c0feb 458 30, 0, 0)
8b11a64c
ZD
459
460/* The induction variable optimizations give up on loops that contain more
461 induction variable uses. */
462
463DEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
464 "iv-max-considered-uses",
465 "Bound on number of iv uses in loop optimized in iv optimizations",
e06c0feb 466 250, 0, 0)
8b11a64c 467
36f5ada1
ZD
468/* If there are at most this number of ivs in the set, try removing unnecessary
469 ivs from the set always. */
470
471DEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
472 "iv-always-prune-cand-set-bound",
473 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization",
474 10, 0, 0)
475
2412d35c
SP
476DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
477 "scev-max-expr-size",
478 "Bound on size of expressions used in the scalar evolutions analyzer",
14dd9aab
SP
479 100, 0, 0)
480
481DEFPARAM(PARAM_SCEV_MAX_EXPR_COMPLEXITY,
482 "scev-max-expr-complexity",
483 "Bound on the complexity of the expressions in the scalar evolutions analyzer",
484 10, 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
dabd47e7
JJ
696/* This is the maximum number of active local stores RTL DSE will consider. */
697DEFPARAM (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES,
698 "max-dse-active-local-stores",
699 "Maximum number of active local stores in RTL dead store elimination",
700 5000, 0, 0)
701
47eb5b32
ZD
702/* Prefetching and cache-optimizations related parameters. Default values are
703 usually set by machine description. */
704
705/* The number of insns executed before prefetch is completed. */
706
707DEFPARAM (PARAM_PREFETCH_LATENCY,
708 "prefetch-latency",
709 "The number of insns executed before prefetch is completed",
710 200, 0, 0)
711
712/* The number of prefetches that can run at the same time. */
713
714DEFPARAM (PARAM_SIMULTANEOUS_PREFETCHES,
715 "simultaneous-prefetches",
716 "The number of prefetches that can run at the same time",
717 3, 0, 0)
718
46cb0441 719/* The size of L1 cache in kB. */
47eb5b32
ZD
720
721DEFPARAM (PARAM_L1_CACHE_SIZE,
722 "l1-cache-size",
723 "The size of L1 cache",
46cb0441 724 64, 0, 0)
47eb5b32
ZD
725
726/* The size of L1 cache line in bytes. */
727
728DEFPARAM (PARAM_L1_CACHE_LINE_SIZE,
729 "l1-cache-line-size",
730 "The size of L1 cache line",
731 32, 0, 0)
732
46cb0441
ZD
733/* The size of L2 cache in kB. */
734
735DEFPARAM (PARAM_L2_CACHE_SIZE,
736 "l2-cache-size",
737 "The size of L2 cache",
738 512, 0, 0)
739
7313518b
DG
740/* Whether we should use canonical types rather than deep "structural"
741 type checking. Setting this value to 1 (the default) improves
742 compilation performance in the C++ and Objective-C++ front end;
743 this value should only be set to zero to work around bugs in the
744 canonical type system by disabling it. */
745
746DEFPARAM (PARAM_USE_CANONICAL_TYPES,
747 "use-canonical-types",
748 "Whether to use canonical types",
749 1, 0, 1)
f0ed4cfb
NC
750
751DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH,
752 "max-partial-antic-length",
753 "Maximum length of partial antic set when performing tree pre optimization",
754 100, 0, 0)
755
863d2a57
RG
756/* The following is used as a stop-gap limit for cases where really huge
757 SCCs blow up memory and compile-time use too much. If we hit this limit,
758 SCCVN and such FRE and PRE will be not done at all for the current
759 function. */
760
761DEFPARAM (PARAM_SCCVN_MAX_SCC_SIZE,
762 "sccvn-max-scc-size",
763 "Maximum size of a SCC before SCCVN stops processing a function",
764 10000, 10, 0)
765
058e97ec
VM
766DEFPARAM (PARAM_IRA_MAX_LOOPS_NUM,
767 "ira-max-loops-num",
7b98c16f 768 "Max loops number for regional RA",
30ea859e 769 100, 0, 0)
058e97ec 770
311aab06
VM
771DEFPARAM (PARAM_IRA_MAX_CONFLICT_TABLE_SIZE,
772 "ira-max-conflict-table-size",
7b98c16f 773 "Max size of conflict table in MB",
7cd06356 774 1000, 0, 0)
311aab06 775
1833192f
VM
776DEFPARAM (PARAM_IRA_LOOP_RESERVED_REGS,
777 "ira-loop-reserved-regs",
778 "The number of registers in each class kept unused by loop invariant motion",
779 2, 0, 0)
780
b6e99746
MJ
781/* Switch initialization conversion will refuse to create arrays that are
782 bigger than this parameter times the number of switch branches. */
783
784DEFPARAM (PARAM_SWITCH_CONVERSION_BRANCH_RATIO,
785 "switch-conversion-max-branch-ratio",
786 "The maximum ratio between array size and switch branches for "
787 "a switch conversion to take place",
788 8, 1, 0)
789
e797c5f2
SP
790/* Size of tiles when doing loop blocking. */
791
792DEFPARAM (PARAM_LOOP_BLOCK_TILE_SIZE,
793 "loop-block-tile-size",
794 "size of tiles for loop blocking",
795 51, 0, 0)
796
4e7dd376
SP
797/* Maximal number of parameters that we allow in a SCoP. */
798
799DEFPARAM (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS,
800 "graphite-max-nb-scop-params",
d97c90ae 801 "maximum number of parameters in a SCoP",
4e7dd376
SP
802 10, 0, 0)
803
b6bb0094
SP
804/* Maximal number of basic blocks in the functions analyzed by Graphite. */
805
806DEFPARAM (PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION,
807 "graphite-max-bbs-per-function",
d97c90ae 808 "maximum number of basic blocks per function to be analyzed by Graphite",
b6bb0094
SP
809 100, 0, 0)
810
b1fb9f56
JJ
811/* Avoid doing loop invariant motion on very large loops. */
812
813DEFPARAM (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP,
814 "loop-invariant-max-bbs-in-loop",
7b98c16f 815 "Max basic blocks number in loop for loop invariant motion",
b1fb9f56
JJ
816 10000, 0, 0)
817
a70d6342
IR
818/* Avoid SLP vectorization of large basic blocks. */
819DEFPARAM (PARAM_SLP_MAX_INSNS_IN_BB,
820 "slp-max-insns-in-bb",
821 "Maximum number of instructions in basic block to be considered for SLP vectorization",
822 1000, 0, 0)
823
db34470d
GS
824DEFPARAM (PARAM_MIN_INSN_TO_PREFETCH_RATIO,
825 "min-insn-to-prefetch-ratio",
7b98c16f 826 "Min. ratio of insns to prefetches to enable prefetching for "
db34470d
GS
827 "a loop with an unknown trip count",
828 10, 0, 0)
829
830DEFPARAM (PARAM_PREFETCH_MIN_INSN_TO_MEM_RATIO,
831 "prefetch-min-insn-to-mem-ratio",
7b98c16f 832 "Min. ratio of insns to mem ops to enable prefetching in a loop",
db34470d
GS
833 3, 0, 0)
834
ec8c3978
JJ
835/* Set maximum hash table size for var tracking. */
836
837DEFPARAM (PARAM_MAX_VARTRACK_SIZE,
838 "max-vartrack-size",
839 "Max. size of var tracking hash tables",
840 50000000, 0, 0)
841
b5b8b0ac
AO
842/* Set minimum insn uid for non-debug insns. */
843
844DEFPARAM (PARAM_MIN_NONDEBUG_INSN_UID,
845 "min-nondebug-insn-uid",
846 "The minimum UID to be used for a nondebug insn",
847 0, 1, 0)
848
07ffa034
MJ
849DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR,
850 "ipa-sra-ptr-growth-factor",
7b98c16f 851 "Maximum allowed growth of size of new parameters ipa-sra replaces "
07ffa034
MJ
852 "a pointer to an aggregate with",
853 2, 0, 0)
854
3949c4a7
MJ
855DEFPARAM (PARAM_DEVIRT_TYPE_LIST_SIZE,
856 "devirt-type-list-size",
857 "Maximum size of a type list associated with each parameter for "
858 "devirtualization",
859 8, 0, 0)
860
852e4bd2
JH
861/* WHOPR partitioning configuration. */
862
863DEFPARAM (PARAM_LTO_PARTITIONS,
864 "lto-partitions",
1cd9e416 865 "Number of partitions the program should be split to",
9bfbc1eb 866 32, 1, 0)
852e4bd2
JH
867
868DEFPARAM (MIN_PARTITION_SIZE,
869 "lto-min-partition",
ac43f774 870 "Minimal size of a partition for LTO (in estimated instructions)",
852e4bd2 871 1000, 0, 0)
501c95ff
NF
872
873/* Diagnostic parameters. */
874
875DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP,
876 "cxx-max-namespaces-for-diagnostic-help",
877 "Maximum number of namespaces to search for alternatives when "
878 "name lookup fails",
879 1000, 0, 0)
880
bfe068c3
IR
881/* Maximum number of conditional store pairs that can be sunk. */
882DEFPARAM (PARAM_MAX_STORES_TO_SINK,
883 "max-stores-to-sink",
884 "Maximum number of conditional store pairs that can be sunk",
885 2, 0, 0)
886
887
c6d9a88c
MM
888/*
889Local variables:
890mode:c
f4b4a3e2
NC
891End:
892*/