190075Sobrien/* params.def - Run-time parameters.
2169689Skan   Copyright (C) 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
390075Sobrien   Written by Mark Mitchell <mark@codesourcery.com>.
490075Sobrien
590075SobrienThis file is part of GCC.
690075Sobrien
790075SobrienGCC is free software; you can redistribute it and/or modify it under
890075Sobrienthe terms of the GNU General Public License as published by the Free
990075SobrienSoftware Foundation; either version 2, or (at your option) any later
1090075Sobrienversion.
1190075Sobrien
1290075SobrienGCC is distributed in the hope that it will be useful, but WITHOUT ANY
1390075SobrienWARRANTY; without even the implied warranty of MERCHANTABILITY or
1490075SobrienFITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
1590075Sobrienfor more details.
1690075Sobrien
1790075SobrienYou should have received a copy of the GNU General Public License
1890075Sobrienalong with GCC; see the file COPYING.  If not, write to the Free
19169689SkanSoftware Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
20169689Skan02110-1301, USA.
2190075Sobrien
2290075Sobrien*/
2390075Sobrien
2490075Sobrien/* This file contains definitions for language-independent
25169689Skan   parameters.  The DEFPARAM macro takes 6 arguments:
2690075Sobrien
2790075Sobrien     - The enumeral corresponding to this parameter.
2890075Sobrien
2990075Sobrien     - The name that can be used to set this parameter using the 
3090075Sobrien       command-line option `--param <name>=<value>'.
3190075Sobrien
3290075Sobrien     - A help string explaining how the parameter is used.
3390075Sobrien
3490075Sobrien     - A default value for the parameter.
3590075Sobrien
36169689Skan     - The minimum acceptable value for the parameter.
37169689Skan
38169689Skan     - The maximum acceptable value for the parameter (if greater than
39169689Skan     the minimum).
40169689Skan
4190075Sobrien   Be sure to add an entry to invoke.texi summarizing the parameter.  */
4290075Sobrien
43169689Skan/* The maximum number of fields in a variable with only implicit uses
44169689Skan   for which structure aliasing will consider trying to track each
45169689Skan   field.  The default is 5.  */
46169689SkanDEFPARAM (PARAM_SALIAS_MAX_IMPLICIT_FIELDS,
47169689Skan	  "salias-max-implicit-fields",
48169689Skan	  "The maximum number of fields in a structure variable without direct structure accesses that GCC will attempt to track separately",
49169689Skan	  5, 0, 0)
50169689Skan
51169689Skan/* The maximum number of array elements structure aliasing will decompose
52169689Skan   an array for.  The default is 4.  */
53169689SkanDEFPARAM (PARAM_SALIAS_MAX_ARRAY_ELEMENTS,
54169689Skan	  "salias-max-array-elements",
55169689Skan	  "The maximum number of elements in an array for wich we track its elements separately",
56169689Skan	  4, 0, 0)
57169689Skan
58169689Skan/* The maximum structure size at which the scalar replacement of
59169689Skan   aggregates (SRA) pass will perform block copies.  The default
60169689Skan   value, 0, implies that GCC will select the most appropriate size
61169689Skan   itself.  */
62169689SkanDEFPARAM (PARAM_SRA_MAX_STRUCTURE_SIZE,
63169689Skan	  "sra-max-structure-size",
64169689Skan	  "The maximum structure size (in bytes) for which GCC will "
65169689Skan	  "use by-element copies",
66169689Skan	  0, 0, 0)
67169689Skan
68169689Skan/* The maximum number of structure fields which the SRA pass will
69169689Skan   instantiate to avoid block copies.  The default value, 0, implies
70169689Skan   that GCC will select the appropriate value itself.  */
71169689SkanDEFPARAM (PARAM_SRA_MAX_STRUCTURE_COUNT,
72169689Skan	  "sra-max-structure-count",
73169689Skan	  "The maximum number of structure fields for which GCC will "
74169689Skan	  "use by-element copies",
75169689Skan	  0, 0, 0)
76169689Skan
77169689Skan/* The ratio between instantiated fields and the complete structure
78169689Skan   size.  We say that if the ratio of the number of bytes in
79169689Skan   instantiated fields to the number of bytes in the complete
80169689Skan   structure exceeds this parameter, or if the number of instantiated
81169689Skan   fields to the total number of fields exceeds this parameter, then
82169689Skan   block copies are not used.  The default is 75%.  */
83169689SkanDEFPARAM (PARAM_SRA_FIELD_STRUCTURE_RATIO,
84169689Skan	  "sra-field-structure-ratio",
85169689Skan	  "The threshold ratio between instantiated fields and the total structure size",
86169689Skan	  75, 0, 100)
87169689Skan
88117395Skan/* The single function inlining limit. This is the maximum size
89117395Skan   of a function counted in internal gcc instructions (not in
90117395Skan   real machine instructions) that is eligible for inlining
91117395Skan   by the tree inliner.
92169689Skan   The default value is 450.
93117395Skan   Only functions marked inline (or methods defined in the class
94169689Skan   definition for C++) are affected by this.
95117395Skan   There are more restrictions to inlining: If inlined functions
96117395Skan   call other functions, the already inlined instructions are
97117395Skan   counted and once the recursive inline limit (see 
98117395Skan   "max-inline-insns" parameter) is exceeded, the acceptable size
99117395Skan   gets decreased.  */
100117395SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
101117395Skan	  "max-inline-insns-single",
102117395Skan	  "The maximum number of instructions in a single function eligible for inlining",
103169689Skan	  450, 0, 0)
104117395Skan
105117395Skan/* The single function inlining limit for functions that are
106117395Skan   inlined by virtue of -finline-functions (-O3).
107117395Skan   This limit should be chosen to be below or equal to the limit
108117395Skan   that is applied to functions marked inlined (or defined in the
109117395Skan   class declaration in C++) given by the "max-inline-insns-single"
110117395Skan   parameter.
111169689Skan   The default value is 90.  */
112117395SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
113117395Skan	  "max-inline-insns-auto",
114117395Skan	  "The maximum number of instructions when automatically inlining",
115169689Skan	  90, 0, 0)
116117395Skan
117169689SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE,
118169689Skan	  "max-inline-insns-recursive",
119169689Skan	  "The maximum number of instructions inline function can grow to via recursive inlining",
120169689Skan	  450, 0, 0)
121117395Skan
122169689SkanDEFPARAM (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO,
123169689Skan	  "max-inline-insns-recursive-auto",
124169689Skan	  "The maximum number of instructions non-inline function can grow to via recursive inlining",
125169689Skan	  450, 0, 0)
126169689Skan
127169689SkanDEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH,
128169689Skan	  "max-inline-recursive-depth",
129169689Skan	  "The maximum depth of recursive inlining for inline functions",
130169689Skan	  8, 0, 0)
131169689Skan
132169689SkanDEFPARAM (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO,
133169689Skan	  "max-inline-recursive-depth-auto",
134169689Skan	  "The maximum depth of recursive inlining for non-inline functions",
135169689Skan	  8, 0, 0)
136169689Skan
137169689SkanDEFPARAM (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY,
138169689Skan	  "min-inline-recursive-probability",
139169689Skan	  "Inline recursively only when the probability of call being executed exceeds the parameter",
140169689Skan	  10, 0, 0)
141169689Skan
142169689Skan/* Limit the number of expansions created by the variable expansion
143169689Skan   optimization to avoid register pressure.  */
144169689SkanDEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
145169689Skan	  "max-variable-expansions-in-unroller",
146169689Skan	  "If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling",
147169689Skan          1, 0, 0)
148169689Skan     
14990075Sobrien/* The maximum number of instructions to consider when looking for an
15090075Sobrien   instruction to fill a delay slot.  If more than this arbitrary
15190075Sobrien   number of instructions is searched, the time savings from filling
15290075Sobrien   the delay slot will be minimal so stop searching.  Increasing
15390075Sobrien   values mean more aggressive optimization, making the compile time
15490075Sobrien   increase with probably small improvement in executable run time.  */
15590075SobrienDEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
15690075Sobrien	  "max-delay-slot-insn-search",
15790075Sobrien	  "The maximum number of instructions to consider to fill a delay slot",
158169689Skan	  100, 0, 0)
15990075Sobrien
16090075Sobrien/* When trying to fill delay slots, the maximum number of instructions
16190075Sobrien   to consider when searching for a block with valid live register
16290075Sobrien   information.  Increasing this arbitrarily chosen value means more
16390075Sobrien   aggressive optimization, increasing the compile time.  This
16490075Sobrien   parameter should be removed when the delay slot code is rewritten
16590075Sobrien   to maintain the control-flow graph.  */
16690075SobrienDEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
16790075Sobrien	 "max-delay-slot-live-search",
16890075Sobrien	 "The maximum number of instructions to consider to find accurate live register information",
169169689Skan	 333, 0, 0)
17090075Sobrien
17190075Sobrien/* This parameter limits the number of branch elements that the 
17290075Sobrien   scheduler will track anti-dependencies through without resetting
17390075Sobrien   the tracking mechanism.  Large functions with few calls or barriers 
17490075Sobrien   can generate lists containing many 1000's of dependencies.  Generally 
17590075Sobrien   the compiler either uses all available memory, or runs for far too long.  */
17690075SobrienDEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
17790075Sobrien	 "max-pending-list-length",
17890075Sobrien	 "The maximum length of scheduling's pending operations list",
179169689Skan	 32, 0, 0)
18090075Sobrien
181132718SkanDEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
182132718Skan	 "large-function-insns",
183132718Skan	 "The size of function body to be considered large",
184169689Skan	 2700, 0, 0)
185132718SkanDEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
186132718Skan	 "large-function-growth",
187132718Skan	 "Maximal growth due to inlining of large function (in percent)",
188169689Skan	 100, 0, 0)
189169689SkanDEFPARAM(PARAM_LARGE_UNIT_INSNS,
190169689Skan	 "large-unit-insns",
191169689Skan	 "The size of translation unit to be considered large",
192169689Skan	 10000, 0, 0)
193132718SkanDEFPARAM(PARAM_INLINE_UNIT_GROWTH,
194132718Skan	 "inline-unit-growth",
195132718Skan	 "how much can given compilation unit grow because of the inlining (in percent)",
196169689Skan	 50, 0, 0)
197169689SkanDEFPARAM(PARAM_INLINE_CALL_COST,
198169689Skan	 "inline-call-cost",
199169689Skan	 "expense of call operation relative to ordinary arithmetic operations",
200169689Skan	 16, 0, 0)
201132718Skan
20290075Sobrien/* The GCSE optimization will be disabled if it would require
20390075Sobrien   significantly more memory than this value.  */
20490075SobrienDEFPARAM(PARAM_MAX_GCSE_MEMORY,
20590075Sobrien	 "max-gcse-memory",
20690075Sobrien	 "The maximum amount of memory to be allocated by GCSE",
207169689Skan	 50 * 1024 * 1024, 0, 0)
208117395Skan/* The number of repetitions of copy/const prop and PRE to run.  */
20990075SobrienDEFPARAM(PARAM_MAX_GCSE_PASSES,
21090075Sobrien	"max-gcse-passes",
21190075Sobrien	"The maximum number of passes to make when doing GCSE",
212169689Skan	1, 1, 0)
213169689Skan/* This is the threshold ratio when to perform partial redundancy
214169689Skan   elimination after reload. We perform partial redundancy elimination
215169689Skan   when the following holds:
216169689Skan   (Redundant load execution count)
217169689Skan   ------------------------------- >= GCSE_AFTER_RELOAD_PARTIAL_FRACTION
218169689Skan   (Added loads execution count)					  */
219169689SkanDEFPARAM(PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
220169689Skan	"gcse-after-reload-partial-fraction",
221169689Skan	"The threshold ratio for performing partial redundancy elimination after reload",
222169689Skan        3, 0, 0)
223169689Skan/* This is the threshold ratio of the critical edges execution count compared to
224169689Skan   the redundant loads execution count that permits performing the load
225169689Skan   redundancy elimination in gcse after reload.  */
226169689SkanDEFPARAM(PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION,
227169689Skan	"gcse-after-reload-critical-fraction",
228169689Skan	"The threshold ratio of critical edges execution count that permit performing redundancy elimination after reload",
229169689Skan        10, 0, 0)
230117395Skan/* This parameter limits the number of insns in a loop that will be unrolled,
231132718Skan   and by how much the loop is unrolled.
232132718Skan   
233132718Skan   This limit should be at most half of the peeling limits:  loop unroller
234132718Skan   decides to not unroll loops that iterate fewer than 2*number of allowed
235169689Skan   unrollings and thus we would have loops that are neither peeled or unrolled
236132718Skan   otherwise.  */
237117395SkanDEFPARAM(PARAM_MAX_UNROLLED_INSNS,
238117395Skan	 "max-unrolled-insns",
239117395Skan	 "The maximum number of instructions to consider to unroll in a loop",
240169689Skan	 200, 0, 0)
241132718Skan/* This parameter limits how many times the loop is unrolled depending
242132718Skan   on number of insns really executed in each iteration.  */
243132718SkanDEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
244132718Skan	 "max-average-unrolled-insns",
245132718Skan	 "The maximum number of instructions to consider to unroll in a loop on average",
246169689Skan	 80, 0, 0)
247132718Skan/* The maximum number of unrollings of a single loop.  */
248132718SkanDEFPARAM(PARAM_MAX_UNROLL_TIMES,
249132718Skan	"max-unroll-times",
250132718Skan	"The maximum number of unrollings of a single loop",
251169689Skan	8, 0, 0)
252132718Skan/* The maximum number of insns of a peeled loop.  */
253132718SkanDEFPARAM(PARAM_MAX_PEELED_INSNS,
254132718Skan	"max-peeled-insns",
255132718Skan	"The maximum number of insns of a peeled loop",
256169689Skan	400, 0, 0)
257132718Skan/* The maximum number of peelings of a single loop.  */
258132718SkanDEFPARAM(PARAM_MAX_PEEL_TIMES,
259132718Skan	"max-peel-times",
260132718Skan	"The maximum number of peelings of a single loop",
261169689Skan	16, 0, 0)
262132718Skan/* The maximum number of insns of a peeled loop.  */
263132718SkanDEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
264132718Skan	"max-completely-peeled-insns",
265132718Skan	"The maximum number of insns of a completely peeled loop",
266169689Skan	400, 0, 0)
267132718Skan/* The maximum number of peelings of a single loop that is peeled completely.  */
268132718SkanDEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
269132718Skan	"max-completely-peel-times",
270132718Skan	"The maximum number of peelings of a single loop that is peeled completely",
271169689Skan	16, 0, 0)
272132718Skan/* The maximum number of insns of a peeled loop that rolls only once.  */
273132718SkanDEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
274132718Skan	"max-once-peeled-insns",
275132718Skan	"The maximum number of insns of a peeled loop that rolls only once",
276169689Skan	400, 0, 0)
277117395Skan
278132718Skan/* The maximum number of insns of an unswitched loop.  */
279132718SkanDEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
280132718Skan	"max-unswitch-insns",
281132718Skan	"The maximum number of insns of an unswitched loop",
282169689Skan	50, 0, 0)
283132718Skan/* The maximum level of recursion in unswitch_single_loop.  */
284132718SkanDEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
285132718Skan	"max-unswitch-level",
286132718Skan	"The maximum number of unswitchings in a single loop",
287169689Skan	3, 0, 0)
288132718Skan
289169689Skan/* The maximum number of iterations of a loop the brute force algorithm
290169689Skan   for analysis of # of iterations of the loop tries to evaluate.  */
291169689SkanDEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,
292169689Skan	"max-iterations-to-track",
293169689Skan	"Bound on the number of iterations the brute force # of iterations analysis algorithm evaluates",
294169689Skan	1000, 0, 0)
295169689Skan/* A cutoff to avoid costly computations of the number of iterations in
296169689Skan   the doloop transformation.  */
297169689SkanDEFPARAM(PARAM_MAX_ITERATIONS_COMPUTATION_COST,
298169689Skan	"max-iterations-computation-cost",
299169689Skan	"Bound on the cost of an expression to compute the number of iterations",
300169689Skan	10, 0, 0)
301169689Skan
302169689SkanDEFPARAM(PARAM_MAX_SMS_LOOP_NUMBER,
303169689Skan	 "max-sms-loop-number",
304169689Skan	 "Maximum number of loops to perform swing modulo scheduling on (mainly for debugging)",
305169689Skan	 -1, -1, -1)
306169689Skan  
307169689Skan/* This parameter is used to tune SMS MAX II calculations.  */
308169689SkanDEFPARAM(PARAM_SMS_MAX_II_FACTOR,
309169689Skan	 "sms-max-ii-factor",
310169689Skan	 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop",
311169689Skan	 100, 0, 0)
312169689SkanDEFPARAM(PARAM_SMS_DFA_HISTORY,
313169689Skan	 "sms-dfa-history",
314169689Skan	 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA",
315169689Skan	 0, 0, 0)
316169689SkanDEFPARAM(PARAM_SMS_LOOP_AVERAGE_COUNT_THRESHOLD,
317169689Skan	 "sms-loop-average-count-threshold",
318169689Skan	 "A threshold on the average loop count considered by the swing modulo scheduler",
319169689Skan	 0, 0, 0)
320169689Skan
321117395SkanDEFPARAM(HOT_BB_COUNT_FRACTION,
322117395Skan	 "hot-bb-count-fraction",
323169689Skan	 "Select fraction of the maximal count of repetitions of basic block in program given basic block needs to have to be considered hot",
324169689Skan	 10000, 0, 0)
325117395SkanDEFPARAM(HOT_BB_FREQUENCY_FRACTION,
326117395Skan	 "hot-bb-frequency-fraction",
327169689Skan	 "Select fraction of the maximal frequency of executions of basic block in function given basic block needs to have to be considered hot",
328169689Skan	 1000, 0, 0)
329169689Skan
330169689Skan/* For guessed profiles, the loops having unknown number of iterations
331169689Skan   are predicted to iterate relatively few (10) times at average.
332169689Skan   For functions containing one loop with large known number of iterations
333169689Skan   and other loops having unbounded loops we would end up predicting all
334169689Skan   the other loops cold that is not usually the case.  So we need to artificially
335169689Skan   flatten the profile.  
336169689Skan
337169689Skan   We need to cut the maximal predicted iterations to large enough iterations
338169689Skan   so the loop appears important, but safely within HOT_BB_COUNT_FRACTION
339169689Skan   range.  */
340169689Skan
341169689SkanDEFPARAM(PARAM_MAX_PREDICTED_ITERATIONS,
342169689Skan	 "max-predicted-iterations",
343169689Skan	 "The maximum number of loop iterations we predict statically",
344169689Skan	 100, 0, 0)
345117395SkanDEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
346117395Skan	 "tracer-dynamic-coverage-feedback",
347169689Skan	 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is available",
348169689Skan	 95, 0, 100)
349117395SkanDEFPARAM(TRACER_DYNAMIC_COVERAGE,
350117395Skan	 "tracer-dynamic-coverage",
351169689Skan	 "The percentage of function, weighted by execution frequency, that must be covered by trace formation. Used when profile feedback is not available",
352169689Skan	 75, 0, 100)
353117395SkanDEFPARAM(TRACER_MAX_CODE_GROWTH,
354117395Skan	 "tracer-max-code-growth",
355132718Skan	 "Maximal code growth caused by tail duplication (in percent)",
356169689Skan	 100, 0, 0)
357117395SkanDEFPARAM(TRACER_MIN_BRANCH_RATIO,
358117395Skan	 "tracer-min-branch-ratio",
359169689Skan	 "Stop reverse growth if the reverse probability of best edge is less than this threshold (in percent)",
360169689Skan	 10, 0, 100)
361117395SkanDEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
362117395Skan	 "tracer-min-branch-probability-feedback",
363169689Skan	 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is available",
364169689Skan	 80, 0, 100)
365117395SkanDEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
366117395Skan	 "tracer-min-branch-probability",
367169689Skan	 "Stop forward growth if the probability of best edge is less than this threshold (in percent). Used when profile feedback is not available",
368169689Skan	 50, 0, 100)
369117395Skan
370117395Skan/* The maximum number of incoming edges to consider for crossjumping.  */
371117395SkanDEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
372117395Skan	 "max-crossjump-edges",
373117395Skan	 "The maximum number of incoming edges to consider for crossjumping",
374169689Skan	 100, 0, 0)
375117395Skan
376169689Skan/* The minimum number of matching instructions to consider for crossjumping.  */
377169689SkanDEFPARAM(PARAM_MIN_CROSSJUMP_INSNS,
378169689Skan     "min-crossjump-insns",
379169689Skan     "The minimum number of matching instructions to consider for crossjumping",
380169689Skan     5, 0, 0)
381169689Skan
382169689Skan/* The maximum number expansion factor when copying basic blocks.  */
383169689SkanDEFPARAM(PARAM_MAX_GROW_COPY_BB_INSNS,
384169689Skan     "max-grow-copy-bb-insns",
385169689Skan     "The maximum expansion factor when copying basic blocks",
386169689Skan     8, 0, 0)
387169689Skan
388169689Skan/* The maximum number of insns to duplicate when unfactoring computed gotos.  */
389169689SkanDEFPARAM(PARAM_MAX_GOTO_DUPLICATION_INSNS,
390169689Skan     "max-goto-duplication-insns",
391169689Skan     "The maximum number of insns to duplicate when unfactoring computed gotos",
392169689Skan     8, 0, 0)
393169689Skan
394132718Skan/* The maximum length of path considered in cse.  */
395132718SkanDEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
396132718Skan	 "max-cse-path-length",
397132718Skan	 "The maximum length of path considered in cse",
398169689Skan	 10, 0, 0)
399169689SkanDEFPARAM(PARAM_MAX_CSE_INSNS,
400169689Skan	 "max-cse-insns",
401169689Skan	 "The maximum instructions CSE process before flushing",
402169689Skan	 1000, 0, 0)
403132718Skan
404169689Skan/* The cost of expression in loop invariant motion that is considered
405169689Skan   expensive.  */
406169689SkanDEFPARAM(PARAM_LIM_EXPENSIVE,
407169689Skan	 "lim-expensive",
408169689Skan	 "The minimum cost of an expensive expression in the loop invariant motion",
409169689Skan	 20, 0, 0)
410169689Skan
411169689Skan/* Bound on number of candidates for induction variables below that
412169689Skan   all candidates are considered for each use in induction variable
413169689Skan   optimizations.  */
414169689Skan
415169689SkanDEFPARAM(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
416169689Skan	 "iv-consider-all-candidates-bound",
417169689Skan	 "Bound on number of candidates below that all candidates are considered in iv optimizations",
418169689Skan	 30, 0, 0)
419169689Skan
420169689Skan/* The induction variable optimizations give up on loops that contain more
421169689Skan   induction variable uses.  */
422169689Skan
423169689SkanDEFPARAM(PARAM_IV_MAX_CONSIDERED_USES,
424169689Skan	 "iv-max-considered-uses",
425169689Skan	 "Bound on number of iv uses in loop optimized in iv optimizations",
426169689Skan	 250, 0, 0)
427169689Skan
428169689Skan/* If there are at most this number of ivs in the set, try removing unnecessary
429169689Skan   ivs from the set always.  */
430169689Skan
431169689SkanDEFPARAM(PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND,
432169689Skan	 "iv-always-prune-cand-set-bound",
433169689Skan	 "If number of candidates in the set is smaller, we always try to remove unused ivs during its optimization",
434169689Skan	 10, 0, 0)
435169689Skan
436169689SkanDEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
437169689Skan 	 "scev-max-expr-size",
438169689Skan	 "Bound on size of expressions used in the scalar evolutions analyzer",
439169689Skan	 20, 0, 0)
440169689Skan
441169689SkanDEFPARAM(PARAM_VECT_MAX_VERSION_CHECKS,
442169689Skan         "vect-max-version-checks",
443169689Skan         "Bound on number of runtime checks inserted by the vectorizer's loop versioning",
444169689Skan         6, 0, 0)
445169689Skan
446169689Skan/* The product of the next two is used to decide whether or not to
447169689Skan   use .GLOBAL_VAR.  See tree-dfa.c.  */
448169689SkanDEFPARAM(PARAM_GLOBAL_VAR_THRESHOLD,
449169689Skan	"global-var-threshold",
450169689Skan	"Given N calls and V call-clobbered vars in a function.  Use .GLOBAL_VAR if NxV is larger than this limit",
451169689Skan	500000, 0, 0)
452169689Skan
453132718SkanDEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
454132718Skan	 "max-cselib-memory-locations",
455132718Skan	 "The maximum memory locations recorded by cselib",
456169689Skan	 500, 0, 0)
457169689SkanDEFPARAM(PARAM_MAX_FLOW_MEMORY_LOCATIONS,
458169689Skan	 "max-flow-memory-locations",
459169689Skan	 "The maximum memory locations recorded by flow",
460169689Skan	 100, 0, 0)
461132718Skan
462117395Skan#ifdef ENABLE_GC_ALWAYS_COLLECT
463117395Skan# define GGC_MIN_EXPAND_DEFAULT 0
464117395Skan# define GGC_MIN_HEAPSIZE_DEFAULT 0
465117395Skan#else
466117395Skan# define GGC_MIN_EXPAND_DEFAULT 30
467117395Skan# define GGC_MIN_HEAPSIZE_DEFAULT 4096
468117395Skan#endif
469117395Skan
470117395SkanDEFPARAM(GGC_MIN_EXPAND,
471117395Skan	 "ggc-min-expand",
472169689Skan	 "Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the heap",
473169689Skan	 GGC_MIN_EXPAND_DEFAULT, 0, 0)
474117395Skan
475117395SkanDEFPARAM(GGC_MIN_HEAPSIZE,
476117395Skan	 "ggc-min-heapsize",
477132718Skan	 "Minimum heap size before we start collecting garbage, in kilobytes",
478169689Skan	 GGC_MIN_HEAPSIZE_DEFAULT, 0, 0)
479117395Skan
480117395Skan#undef GGC_MIN_EXPAND_DEFAULT
481117395Skan#undef GGC_MIN_HEAPSIZE_DEFAULT
482117395Skan
483132718SkanDEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
484132718Skan	 "max-reload-search-insns",
485132718Skan	 "The maximum number of instructions to search backward when looking for equivalent reload",
486169689Skan	 100, 0, 0)
487132718Skan
488169689SkanDEFPARAM(PARAM_MAX_ALIASED_VOPS,
489169689Skan         "max-aliased-vops",
490169689Skan	 "The maximum number of virtual operands allowed to represent aliases before triggering alias grouping",
491169689Skan	 500, 0, 0)
492169689Skan
493169689SkanDEFPARAM(PARAM_MAX_SCHED_REGION_BLOCKS,
494169689Skan	 "max-sched-region-blocks",
495169689Skan	 "The maximum number of blocks in a region to be considered for interblock scheduling",
496169689Skan	 10, 0, 0)
497169689Skan
498169689SkanDEFPARAM(PARAM_MAX_SCHED_REGION_INSNS,
499169689Skan	 "max-sched-region-insns",
500169689Skan	 "The maximum number of insns in a region to be considered for interblock scheduling",
501169689Skan	 100, 0, 0)
502169689Skan
503169689SkanDEFPARAM(PARAM_MIN_SPEC_PROB,
504169689Skan         "min-spec-prob",
505169689Skan         "The minimum probability of reaching a source block for interblock speculative scheduling",
506169689Skan         40, 0, 0)
507169689Skan
508169689SkanDEFPARAM(PARAM_MAX_SCHED_EXTEND_REGIONS_ITERS,
509169689Skan         "max-sched-extend-regions-iters",
510169689Skan         "The maximum number of iterations through CFG to extend regions",
511169689Skan         0, 0, 0)
512169689Skan
513169689SkanDEFPARAM(PARAM_MAX_SCHED_INSN_CONFLICT_DELAY,
514169689Skan         "max-sched-insn-conflict-delay",
515169689Skan         "The maximum conflict delay for an insn to be considered for speculative motion",
516169689Skan         3, 1, 10)
517169689Skan
518169689SkanDEFPARAM(PARAM_SCHED_SPEC_PROB_CUTOFF,
519169689Skan         "sched-spec-prob-cutoff",
520169689Skan         "The minimal probability of speculation success (in percents), so that speculative insn will be scheduled.",
521169689Skan         40, 0, 100)
522169689Skan
523169689SkanDEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
524169689Skan	 "max-last-value-rtl",
525169689Skan	 "The maximum number of RTL nodes that can be recorded as combiner's last value",
526169689Skan	 10000, 0, 0)
527169689Skan
528169689Skan/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
529169689Skan   {signed,unsigned} integral types.  This determines N.
530169689Skan   Experimentation shows 256 to be a good value.  */
531169689SkanDEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
532169689Skan	  "integer-share-limit",
533169689Skan	  "The upper bound for sharing integer constants",
534169689Skan	  256, 2, 2)
535169689Skan
536169689Skan/* Incremental SSA updates for virtual operands may be very slow if
537169689Skan   there is a large number of mappings to process.  In those cases, it
538169689Skan   is faster to rewrite the virtual symbols from scratch as if they
539169689Skan   had been recently introduced.  This heuristic cannot be applied to
540169689Skan   SSA mappings for real SSA names, only symbols kept in FUD chains.
541169689Skan
542169689Skan   PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual
543169689Skan   mappings that should be registered to trigger the heuristic.
544169689Skan   
545169689Skan   PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between
546169689Skan   mappings and symbols.  If the number of virtual mappings is
547169689Skan   PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of
548169689Skan   virtual symbols to be updated, then the updater switches to a full
549169689Skan   update for those symbols.  */
550169689SkanDEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS,
551169689Skan	  "min-virtual-mappings",
552169689Skan	  "Minimum number of virtual mappings to consider switching to full virtual renames",
553169689Skan	  100, 0, 0)
554169689Skan
555169689SkanDEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO,
556169689Skan	  "virtual-mappings-ratio",
557169689Skan	  "Ratio between virtual mappings and virtual symbols to do full virtual renames",
558169689Skan	  3, 0, 0)
559169689Skan
560169689SkanDEFPARAM (PARAM_SSP_BUFFER_SIZE,
561169689Skan	  "ssp-buffer-size",
562169689Skan	  "The lower bound for a buffer to be considered for stack smashing protection",
563169689Skan	  8, 1, 0)
564169689Skan
565169689Skan/* When we thread through a block we have to make copies of the
566169689Skan   statements within the block.  Clearly for large blocks the code
567169689Skan   duplication is bad.
568169689Skan
569169689Skan   PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS specifies the maximum number
570169689Skan   of statements and PHI nodes allowed in a block which is going to
571169689Skan   be duplicated for thread jumping purposes.
572169689Skan
573169689Skan   Some simple analysis showed that more than 99% of the jump
574169689Skan   threading opportunities are for blocks with less than 15
575169689Skan   statements.  So we can get the benefits of jump threading
576169689Skan   without excessive code bloat for pathological cases with the
577169689Skan   throttle set at 15 statements.  */
578169689SkanDEFPARAM (PARAM_MAX_JUMP_THREAD_DUPLICATION_STMTS,
579169689Skan	  "max-jump-thread-duplication-stmts",
580169689Skan          "Maximum number of statements allowed in a block that needs to be duplicated when threading jumps",
581169689Skan	  15, 0, 0)
582169689Skan
583169689Skan/* This is the maximum number of fields a variable may have before the pointer analysis machinery
584169689Skan   will stop trying to treat it in a field-sensitive manner.  
585169689Skan   There are programs out there with thousands of fields per structure, and handling them
586169689Skan   field-sensitively is not worth the cost.  */
587169689SkanDEFPARAM (PARAM_MAX_FIELDS_FOR_FIELD_SENSITIVE,
588169689Skan          "max-fields-for-field-sensitive",
589169689Skan	  "Maximum number of fields in a structure before pointer analysis treats the structure as a single variable",
590169689Skan	  100, 0, 0)
591169689Skan
592169689SkanDEFPARAM(PARAM_MAX_SCHED_READY_INSNS,
593169689Skan	 "max-sched-ready-insns",
594169689Skan	 "The maximum number of instructions ready to be issued to be considered by the scheduler during the first scheduling pass",
595169689Skan	 100, 0, 0)
596169689Skan
59790075Sobrien/*
59890075SobrienLocal variables:
59990075Sobrienmode:c
60090075SobrienEnd: */
601