common.opt revision 169689
1; Options for the language- and target-independent parts of the compiler.
2
3; Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
4;
5; This file is part of GCC.
6;
7; GCC is free software; you can redistribute it and/or modify it under
8; the terms of the GNU General Public License as published by the Free
9; Software Foundation; either version 2, or (at your option) any later
10; version.
11;
12; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15; for more details.
16;
17; You should have received a copy of the GNU General Public License
18; along with GCC; see the file COPYING.  If not, write to the Free
19; Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
20; 02110-1301, USA.
21
22; See the GCC internals manual for a description of this file's format.
23
24; Please try to keep this file in ASCII collating order.
25
26-help
27Common
28Display this information
29
30-param
31Common Separate
32--param <param>=<value>	Set parameter <param> to value.  See below for a complete list of parameters
33
34-target-help
35Common
36
37-version
38Common
39
40G
41Common Joined Separate UInteger
42-G<number>	Put global and static data smaller than <number> bytes into a special section (on some targets)
43
44O
45Common JoinedOrMissing
46-O<number>	Set optimization level to <number>
47
48Os
49Common
50Optimize for space rather than speed
51
52W
53Common RejectNegative
54This switch is deprecated; use -Wextra instead
55
56Waggregate-return
57Common Var(warn_aggregate_return)
58Warn about returning structures, unions or arrays
59
60Wattributes
61Common Var(warn_attributes) Init(1)
62Warn about inappropriate attribute usage
63
64Wcast-align
65Common Var(warn_cast_align)
66Warn about pointer casts which increase alignment
67
68Wdeprecated-declarations
69Common Var(warn_deprecated_decl) Init(1)
70Warn about uses of __attribute__((deprecated)) declarations
71
72Wdisabled-optimization
73Common Var(warn_disabled_optimization)
74Warn when an optimization pass is disabled
75
76Werror
77Common Var(warnings_are_errors)
78Treat all warnings as errors
79
80Werror=
81Common Joined
82Treat specified warning as error
83
84Wextra
85Common
86Print extra (possibly unwanted) warnings
87
88Wfatal-errors
89Common Var(flag_fatal_errors)
90Exit on the first error occurred
91
92Winline
93Common Var(warn_inline)
94Warn when an inlined function cannot be inlined
95
96Wlarger-than-
97Common RejectNegative Joined UInteger
98-Wlarger-than-<number>	Warn if an object is larger than <number> bytes
99
100Wunsafe-loop-optimizations
101Common Var(warn_unsafe_loop_optimizations)
102Warn if the loop cannot be optimized due to nontrivial assumptions.
103
104Wmissing-noreturn
105Common Var(warn_missing_noreturn)
106Warn about functions which might be candidates for __attribute__((noreturn))
107
108Woverflow
109Common Var(warn_overflow) Init(1)
110Warn about overflow in arithmetic expressions
111
112Wpacked
113Common Var(warn_packed)
114Warn when the packed attribute has no effect on struct layout
115
116Wpadded
117Common Var(warn_padded)
118Warn when padding is required to align structure members
119
120Wshadow
121Common Var(warn_shadow)
122Warn when one local variable shadows another
123
124Wstack-protector
125Common Var(warn_stack_protect)
126Warn when not issuing stack smashing protection for some reason
127
128Wstrict-aliasing
129Common
130Warn about code which might break strict aliasing rules
131
132Wstrict-aliasing=
133Common Joined UInteger
134Warn about code which might break strict aliasing rules
135
136Wstrict-overflow
137Common
138Warn about optimizations that assume that signed overflow is undefined
139
140Wstrict-overflow=
141Common Joined UInteger
142Warn about optimizations that assume that signed overflow is undefined
143
144Wswitch
145Common Var(warn_switch)
146Warn about enumerated switches, with no default, missing a case
147
148Wswitch-default
149Common Var(warn_switch_default)
150Warn about enumerated switches missing a \"default:\" statement
151
152Wswitch-enum
153Common Var(warn_switch_enum)
154Warn about all enumerated switches missing a specific case
155
156Wsystem-headers
157Common Var(warn_system_headers)
158Do not suppress warnings from system headers
159
160Wuninitialized
161Common Var(warn_uninitialized)
162Warn about uninitialized automatic variables
163
164Wunreachable-code
165Common Var(warn_notreached)
166Warn about code that will never be executed
167
168Wunused
169Common
170Enable all -Wunused- warnings
171
172Wunused-function
173Common Var(warn_unused_function)
174Warn when a function is unused
175
176Wunused-label
177Common Var(warn_unused_label)
178Warn when a label is unused
179
180Wunused-parameter
181Common Var(warn_unused_parameter)
182Warn when a function parameter is unused
183
184Wunused-value
185Common Var(warn_unused_value)
186Warn when an expression value is unused
187
188Wunused-variable
189Common Var(warn_unused_variable)
190Warn when a variable is unused
191
192Wvolatile-register-var
193Common Var(warn_register_var)
194Warn when a register variable is declared volatile
195
196aux-info
197Common Separate
198-aux-info <file>	Emit declaration information into <file>
199
200aux-info=
201Common Joined
202
203auxbase
204Common Separate
205
206auxbase-strip
207Common Separate
208
209d
210Common Joined
211-d<letters>	Enable dumps from specific passes of the compiler
212
213dumpbase
214Common Separate
215-dumpbase <file>	Set the file basename to be used for dumps
216
217; The version of the C++ ABI in use.  The following values are allowed:
218;
219; 0: The version of the ABI believed most conformant with the C++ ABI
220;    specification.  This ABI may change as bugs are discovered and fixed.
221;    Therefore, 0 will not necessarily indicate the same ABI in different
222;    versions of G++.
223;
224; 1: The version of the ABI first used in G++ 3.2.
225;
226; Additional positive integers will be assigned as new versions of
227; the ABI become the default version of the ABI.
228fabi-version=
229Common Joined UInteger Var(flag_abi_version) Init(2)
230
231falign-functions
232Common Report Var(align_functions,0)
233Align the start of functions
234
235falign-functions=
236Common RejectNegative Joined UInteger
237
238falign-jumps
239Common Report Var(align_jumps,0)
240Align labels which are only reached by jumping
241
242falign-jumps=
243Common RejectNegative Joined UInteger
244
245falign-labels
246Common Report Var(align_labels,0)
247Align all labels
248
249falign-labels=
250Common RejectNegative Joined UInteger
251
252falign-loops
253Common Report Var(align_loops)
254Align the start of loops
255
256falign-loops=
257Common RejectNegative Joined UInteger
258
259; This flag is only tested if alias checking is enabled.
260; 0 if pointer arguments may alias each other.  True in C.
261; 1 if pointer arguments may not alias each other but may alias
262;   global variables.
263; 2 if pointer arguments may not alias each other and may not
264;   alias global variables.
265; 3 if pointer arguments may not alias anything.  True in Fortran.
266;   Set by the front end.
267fargument-alias
268Common Report Var(flag_argument_noalias,0)
269Specify that arguments may alias each other and globals
270
271fargument-noalias
272Common Report Var(flag_argument_noalias,1) VarExists
273Assume arguments may alias globals but not each other
274
275fargument-noalias-global
276Common Report Var(flag_argument_noalias,2) VarExists
277Assume arguments alias neither each other nor globals
278
279fargument-noalias-anything
280Common Report Var(flag_argument_noalias,3) VarExists
281Assume arguments alias no other storage
282
283fasynchronous-unwind-tables
284Common Report Var(flag_asynchronous_unwind_tables)
285Generate unwind tables that are exact at each instruction boundary
286
287; -fcheck-bounds causes gcc to generate array bounds checks.
288; For C, C++ and ObjC: defaults off.
289; For Java: defaults to on.
290; For Fortran: defaults to off.
291fbounds-check
292Common Report Var(flag_bounds_check)
293Generate code to check bounds before indexing arrays
294
295fbranch-count-reg
296Common Report Var(flag_branch_on_count_reg) Init(1)
297Replace add, compare, branch with branch on count register
298
299fbranch-probabilities
300Common Report Var(flag_branch_probabilities)
301Use profiling information for branch probabilities
302
303fbranch-target-load-optimize
304Common Report Var(flag_branch_target_load_optimize)
305Perform branch target load optimization before prologue / epilogue threading
306
307fbranch-target-load-optimize2
308Common Report Var(flag_branch_target_load_optimize2)
309Perform branch target load optimization after prologue / epilogue threading
310
311fbtr-bb-exclusive
312Common Report Var(flag_btr_bb_exclusive)
313Restrict target load migration not to re-use registers in any basic block
314
315fcall-saved-
316Common Joined RejectNegative
317-fcall-saved-<register>	Mark <register> as being preserved across functions
318
319fcall-used-
320Common Joined RejectNegative
321-fcall-used-<register>	Mark <register> as being corrupted by function calls
322
323; Nonzero for -fcaller-saves: allocate values in regs that need to
324; be saved across function calls, if that produces overall better code.
325; Optional now, so people can test it.
326fcaller-saves
327Common Report Var(flag_caller_saves)
328Save registers around function calls
329
330fcommon
331Common Report Var(flag_no_common,0)
332Do not put uninitialized globals in the common section
333
334fcprop-registers
335Common Report Var(flag_cprop_registers)
336Perform a register copy-propagation optimization pass
337
338fcrossjumping
339Common Report Var(flag_crossjumping)
340Perform cross-jumping optimization
341
342fcse-follow-jumps
343Common Report Var(flag_cse_follow_jumps)
344When running CSE, follow jumps to their targets
345
346fcse-skip-blocks
347Common Report Var(flag_cse_skip_blocks)
348When running CSE, follow conditional jumps
349
350fcx-limited-range
351Common Report Var(flag_cx_limited_range)
352Omit range reduction step when performing complex division
353
354fdata-sections
355Common Report Var(flag_data_sections)
356Place data items into their own section
357
358; Nonzero for -fdefer-pop: don't pop args after each function call
359; instead save them up to pop many calls' args with one insns.
360fdefer-pop
361Common Report Var(flag_defer_pop)
362Defer popping functions args from stack until later
363
364fdelayed-branch
365Common Report Var(flag_delayed_branch)
366Attempt to fill delay slots of branch instructions
367
368fdelete-null-pointer-checks
369Common Report Var(flag_delete_null_pointer_checks)
370Delete useless null pointer checks
371
372fdiagnostics-show-location=
373Common Joined RejectNegative
374-fdiagnostics-show-location=[once|every-line]	How often to emit source location at the beginning of line-wrapped diagnostics
375
376fdiagnostics-show-option
377Common
378Amend appropriate diagnostic messages with the command line option that controls them
379
380fdump-
381Common Joined RejectNegative
382-fdump-<type>	Dump various compiler internals to a file
383
384fdump-noaddr
385Common Report Var(flag_dump_noaddr)
386Suppress output of addresses in debugging dumps
387
388fdump-unnumbered
389Common Report Var(flag_dump_unnumbered) VarExists
390Suppress output of instruction numbers, line number notes and addresses in debugging dumps
391
392fearly-inlining
393Common Report Var(flag_early_inlining) Init(1)
394Perform early inlining
395
396feliminate-dwarf2-dups
397Common Report Var(flag_eliminate_dwarf2_dups)
398Perform DWARF2 duplicate elimination
399
400feliminate-unused-debug-symbols
401Common Report Var(flag_debug_only_used_symbols)
402Perform unused type elimination in debug info
403
404feliminate-unused-debug-types
405Common Report Var(flag_eliminate_unused_debug_types) Init(1)
406Perform unused type elimination in debug info
407
408femit-class-debug-always
409Common Report Var(flag_emit_class_debug_always) Init(1)
410Do not suppress C++ class debug information.
411
412fexceptions
413Common Report Var(flag_exceptions)
414Enable exception handling
415
416fexpensive-optimizations
417Common Report Var(flag_expensive_optimizations)
418Perform a number of minor, expensive optimizations
419
420ffast-math
421Common
422
423ffinite-math-only
424Common Report Var(flag_finite_math_only)
425Assume no NaNs or infinities are generated
426
427ffixed-
428Common Joined RejectNegative
429-ffixed-<register>	Mark <register> as being unavailable to the compiler
430
431ffloat-store
432Common Report Var(flag_float_store)
433Don't allocate floats and doubles in extended-precision registers
434
435; Nonzero for -fforce-addr: load memory address into a register before
436; reference to memory.  This makes better cse but slower compilation.
437fforce-addr
438Common Report Var(flag_force_addr)
439Copy memory address constants into registers before use
440
441; Nonzero for -fforce-mem: load memory value into a register
442; before arithmetic on it.  This makes better cse but slower compilation.
443fforce-mem
444Common Report Var(flag_force_mem)
445Copy memory operands into registers before use
446
447; Nonzero means don't put addresses of constant functions in registers.
448; Used for compiling the Unix kernel, where strange substitutions are
449; done on the assembly output.
450ffunction-cse
451Common Report Var(flag_no_function_cse,0)
452Allow function addresses to be held in registers
453
454ffunction-sections
455Common Report Var(flag_function_sections)
456Place each function into its own section
457
458fgcse
459Common Report Var(flag_gcse)
460Perform global common subexpression elimination
461
462fgcse-lm
463Common Report Var(flag_gcse_lm) Init(1)
464Perform enhanced load motion during global common subexpression elimination
465
466fgcse-sm
467Common Report Var(flag_gcse_sm) Init(0)
468Perform store motion after global common subexpression elimination
469
470fgcse-las
471Common Report Var(flag_gcse_las) Init(0)
472Perform redundant load after store elimination in global common subexpression
473elimination
474
475fgcse-after-reload
476Common Report Var(flag_gcse_after_reload)
477Perform global common subexpression elimination after register allocation
478has finished
479
480fguess-branch-probability
481Common Report Var(flag_guess_branch_prob)
482Enable guessing of branch probabilities
483
484; Nonzero means ignore `#ident' directives.  0 means handle them.
485; Generate position-independent code for executables if possible
486; On SVR4 targets, it also controls whether or not to emit a
487; string identifying the compiler.
488fident
489Common Report Var(flag_no_ident,0)
490Process #ident directives
491
492fif-conversion
493Common Report Var(flag_if_conversion)
494Perform conversion of conditional jumps to branchless equivalents
495
496fif-conversion2
497Common Report Var(flag_if_conversion2)
498Perform conversion of conditional jumps to conditional execution
499
500; -finhibit-size-directive inhibits output of .size for ELF.
501; This is used only for compiling crtstuff.c,
502; and it may be extended to other effects
503; needed for crtstuff.c on other systems.
504finhibit-size-directive
505Common Report Var(flag_inhibit_size_directive)
506Do not generate .size directives
507
508; Nonzero means that functions declared `inline' will be treated
509; as `static'.  Prevents generation of zillions of copies of unused
510; static inline functions; instead, `inlines' are written out
511; only when actually used.  Used in conjunction with -g.  Also
512; does the right thing with #pragma interface.
513finline
514Common Report Var(flag_no_inline,0) Init(2)
515Pay attention to the \"inline\" keyword
516
517finline-functions
518Common Report Var(flag_inline_functions)
519Integrate simple functions into their callers
520
521finline-functions-called-once
522Common Report Var(flag_inline_functions_called_once) Init(1)
523Integrate functions called once into their callers
524
525finline-limit-
526Common RejectNegative Joined UInteger
527
528finline-limit=
529Common RejectNegative Joined UInteger
530-finline-limit=<number>	Limit the size of inlined functions to <number>
531
532finstrument-functions
533Common Report Var(flag_instrument_function_entry_exit)
534Instrument function entry and exit with profiling calls
535
536fipa-cp
537Common Report Var(flag_ipa_cp)
538Perform Interprocedural constant propagation
539
540fipa-pure-const
541Common Report Var(flag_ipa_pure_const) Init(0)
542Discover pure and const functions
543
544fipa-pta
545Common Report Var(flag_ipa_pta) Init(0)
546Perform interprocedural points-to analysis
547
548fipa-reference
549Common Report Var(flag_ipa_reference) Init(0)
550Discover readonly and non addressable static variables
551
552fipa-type-escape
553Common Report Var(flag_ipa_type_escape) Init(0)
554Type based escape and alias analysis
555
556fivopts
557Common Report Var(flag_ivopts) Init(1)
558Optimize induction variables on trees
559
560fjump-tables
561Common Var(flag_jump_tables) Init(1)
562Use jump tables for sufficiently large switch statements
563
564fkeep-inline-functions
565Common Report Var(flag_keep_inline_functions)
566Generate code for functions even if they are fully inlined
567
568fkeep-static-consts
569Common Report Var(flag_keep_static_consts) Init(1)
570Emit static const variables even if they are not used
571
572fleading-underscore
573Common Report Var(flag_leading_underscore) Init(-1)
574Give external symbols a leading underscore
575
576floop-optimize
577Common
578Does nothing.  Preserved for backward compatibility.
579
580fmath-errno
581Common Report Var(flag_errno_math) Init(1)
582Set errno after built-in math functions
583
584fmem-report
585Common Report Var(mem_report)
586Report on permanent memory allocation
587
588; This will attempt to merge constant section constants, if 1 only
589; string constants and constants from constant pool, if 2 also constant
590; variables.
591fmerge-all-constants
592Common Report Var(flag_merge_constants,2) Init(1)
593Attempt to merge identical constants and constant variables
594
595fmerge-constants
596Common Report Var(flag_merge_constants,1) VarExists
597Attempt to merge identical constants across compilation units
598
599fmessage-length=
600Common RejectNegative Joined UInteger
601-fmessage-length=<number>	Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping
602
603fmodulo-sched
604Common Report Var(flag_modulo_sched)
605Perform SMS based modulo scheduling before the first scheduling pass
606
607fmove-loop-invariants
608Common Report Var(flag_move_loop_invariants) Init(1)
609Move loop invariant computations out of loops
610
611fmudflap
612Common RejectNegative Report Var(flag_mudflap)
613Add mudflap bounds-checking instrumentation for single-threaded program
614
615fmudflapth
616Common RejectNegative Report VarExists Var(flag_mudflap,2)
617Add mudflap bounds-checking instrumentation for multi-threaded program
618
619fmudflapir
620Common RejectNegative Report Var(flag_mudflap_ignore_reads)
621Ignore read operations when inserting mudflap instrumentation
622
623freschedule-modulo-scheduled-loops
624Common Report Var(flag_resched_modulo_sched)
625Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
626
627fnon-call-exceptions
628Common Report Var(flag_non_call_exceptions)
629Support synchronous non-call exceptions
630
631fomit-frame-pointer
632Common Report Var(flag_omit_frame_pointer)
633When possible do not generate stack frames
634
635foptimize-register-move
636Common Report Var(flag_regmove)
637Do the full register move optimization pass
638
639foptimize-sibling-calls
640Common Report Var(flag_optimize_sibling_calls)
641Optimize sibling and tail recursive calls
642
643fpack-struct
644Common Report Var(flag_pack_struct)
645Pack structure members together without holes
646
647fpack-struct=
648Common RejectNegative Joined UInteger
649-fpack-struct=<number>	Set initial maximum structure member alignment
650
651fpcc-struct-return
652Common Report Var(flag_pcc_struct_return,1) VarExists
653Return small aggregates in memory, not registers
654
655fpeel-loops
656Common Report Var(flag_peel_loops)
657Perform loop peeling
658
659fpeephole
660Common Report Var(flag_no_peephole,0)
661Enable machine specific peephole optimizations
662
663fpeephole2
664Common Report Var(flag_peephole2)
665Enable an RTL peephole pass before sched2
666
667fPIC
668Common Report Var(flag_pic,2)
669Generate position-independent code if possible (large mode)
670
671fPIE
672Common Report Var(flag_pie,2)
673Generate position-independent code for executables if possible (large mode)
674
675fpic
676Common Report Var(flag_pic,1) VarExists
677Generate position-independent code if possible (small mode)
678
679fpie
680Common Report Var(flag_pie,1) VarExists
681Generate position-independent code for executables if possible (small mode)
682
683fprefetch-loop-arrays
684Common Report Var(flag_prefetch_loop_arrays)
685Generate prefetch instructions, if available, for arrays in loops
686
687fprofile
688Common Report Var(profile_flag)
689Enable basic program profiling code
690
691fprofile-arcs
692Common Report Var(profile_arc_flag)
693Insert arc-based program profiling code
694
695fprofile-generate
696Common
697Enable common options for generating profile info for profile feedback directed optimizations
698
699fprofile-use
700Common
701Enable common options for performing profile feedback directed optimizations
702
703fprofile-values
704Common Report Var(flag_profile_values)
705Insert code to profile values of expressions
706
707frandom-seed
708Common
709
710frandom-seed=
711Common Joined RejectNegative
712-frandom-seed=<string>	Make compile reproducible using <string>
713
714freg-struct-return
715Common Report Var(flag_pcc_struct_return,0) VarExists
716Return small aggregates in registers
717
718fregmove
719Common Report Var(flag_regmove)
720Enables a register move optimization
721
722frename-registers
723Common Report Var(flag_rename_registers) Init(2)
724Perform a register renaming optimization pass
725
726freorder-blocks
727Common Report Var(flag_reorder_blocks)
728Reorder basic blocks to improve code placement
729
730freorder-blocks-and-partition
731Common Report Var(flag_reorder_blocks_and_partition)
732Reorder basic blocks and partition into hot and cold sections
733
734freorder-functions
735Common Report Var(flag_reorder_functions)
736Reorder functions to improve code placement
737
738frerun-cse-after-loop
739Common Report Var(flag_rerun_cse_after_loop) Init(2)
740Add a common subexpression elimination pass after loop optimizations
741
742frerun-loop-opt
743Common
744Does nothing.  Preserved for backward compatibility.
745
746frounding-math
747Common Report Var(flag_rounding_math)
748Disable optimizations that assume default FP rounding behavior
749
750fsched-interblock
751Common Report Var(flag_schedule_interblock) Init(1)
752Enable scheduling across basic blocks
753
754fsched-spec
755Common Report Var(flag_schedule_speculative) Init(1)
756Allow speculative motion of non-loads
757
758fsched-spec-load
759Common Report Var(flag_schedule_speculative_load)
760Allow speculative motion of some loads
761
762fsched-spec-load-dangerous
763Common Report Var(flag_schedule_speculative_load_dangerous)
764Allow speculative motion of more loads
765
766fsched-verbose=
767Common RejectNegative Joined
768-fsched-verbose=<number>	Set the verbosity level of the scheduler
769
770fsched2-use-superblocks
771Common Report Var(flag_sched2_use_superblocks)
772If scheduling post reload, do superblock scheduling
773
774fsched2-use-traces
775Common Report Var(flag_sched2_use_traces)
776If scheduling post reload, do trace scheduling
777
778fschedule-insns
779Common Report Var(flag_schedule_insns)
780Reschedule instructions before register allocation
781
782fschedule-insns2
783Common Report Var(flag_schedule_insns_after_reload)
784Reschedule instructions after register allocation
785
786; sched_stalled_insns means that insns can be moved prematurely from the queue
787; of stalled insns into the ready list.
788fsched-stalled-insns
789Common Report Var(flag_sched_stalled_insns)
790Allow premature scheduling of queued insns
791
792fsched-stalled-insns=
793Common RejectNegative Joined UInteger
794-fsched-stalled-insns=<number>	Set number of queued insns that can be prematurely scheduled
795
796; sched_stalled_insns_dep controls how many recently scheduled cycles will
797; be examined for a dependency on a stalled insn that is candidate for
798; premature removal from the queue of stalled insns into the ready list (has
799; an effect only if the flag 'sched_stalled_insns' is set).
800fsched-stalled-insns-dep
801Common Report Var(flag_sched_stalled_insns_dep,1) Init(1)
802Set dependence distance checking in premature scheduling of queued insns
803
804fsched-stalled-insns-dep=
805Common RejectNegative Joined UInteger
806-fsched-stalled-insns-dep=<number>	Set dependence distance checking in premature scheduling of queued insns
807
808fsection-anchors
809Common Report Var(flag_section_anchors)
810Access data in the same section from shared anchor points
811
812frtl-abstract-sequences
813Common Report Var(flag_rtl_seqabstr)
814Perform sequence abstraction optimization on RTL
815
816fsee
817Common Report Var(flag_see) Init(0)
818Eliminate redundant sign extensions using LCM.
819
820fshow-column
821Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(1)
822Show column numbers in diagnostics, when available.  Default on
823
824fsignaling-nans
825Common Report Var(flag_signaling_nans)
826Disable optimizations observable by IEEE signaling NaNs
827
828fsingle-precision-constant
829Common Report Var(flag_single_precision_constant)
830Convert floating point constants to single precision constants
831
832fsplit-ivs-in-unroller
833Common Report Var(flag_split_ivs_in_unroller) Init(1)
834Split lifetimes of induction variables when loops are unrolled
835
836fvariable-expansion-in-unroller
837Common Report Var(flag_variable_expansion_in_unroller)
838Apply variable expansion when loops are unrolled
839
840; Emit code to probe the stack, to help detect stack overflow; also
841; may cause large objects to be allocated dynamically.
842fstack-check
843Common Report Var(flag_stack_check)
844Insert stack checking code into the program
845
846fstack-limit
847Common
848
849fstack-limit-register=
850Common RejectNegative Joined
851-fstack-limit-register=<register>	Trap if the stack goes past <register>
852
853fstack-limit-symbol=
854Common RejectNegative Joined
855-fstack-limit-symbol=<name>	Trap if the stack goes past symbol <name>
856
857fstack-protector
858Common Report Var(flag_stack_protect, 1)
859Use propolice as a stack protection method
860
861fstack-protector-all
862Common Report RejectNegative Var(flag_stack_protect, 2) VarExists
863Use a stack protection method for every function
864
865fstrength-reduce
866Common
867Does nothing.  Preserved for backward compatibility.
868
869; Nonzero if we should do (language-dependent) alias analysis.
870; Typically, this analysis will assume that expressions of certain
871; types do not alias expressions of certain other types.  Only used
872; if alias analysis (in general) is enabled.
873fstrict-aliasing
874Common Report Var(flag_strict_aliasing)
875Assume strict aliasing rules apply
876
877fstrict-overflow
878Common Report Var(flag_strict_overflow)
879Treat signed overflow as undefined
880
881fsyntax-only
882Common Report Var(flag_syntax_only)
883Check for syntax errors, then stop
884
885ftest-coverage
886Common Report Var(flag_test_coverage)
887Create data files needed by \"gcov\"
888
889fthread-jumps
890Common Report Var(flag_thread_jumps)
891Perform jump threading optimizations
892
893ftime-report
894Common Report Var(time_report)
895Report the time taken by each compiler pass
896
897ftls-model=
898Common Joined RejectNegative
899-ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]	Set the default thread-local storage code generation model
900
901ftoplevel-reorder
902Common Report Var(flag_toplevel_reorder) Init(1)
903Reorder top level functions, variables, and asms
904
905ftracer
906Common Report Var(flag_tracer)
907Perform superblock formation via tail duplication
908
909; Zero means that floating-point math operations cannot generate a
910; (user-visible) trap.  This is the case, for example, in nonstop
911; IEEE 754 arithmetic.
912ftrapping-math
913Common Report Var(flag_trapping_math) Init(1)
914Assume floating-point operations can trap
915
916ftrapv
917Common Report Var(flag_trapv)
918Trap for signed overflow in addition, subtraction and multiplication
919
920ftree-ccp
921Common Report Var(flag_tree_ccp)
922Enable SSA-CCP optimization on trees
923
924ftree-store-ccp
925Common Report Var(flag_tree_store_ccp)
926Enable SSA-CCP optimization for stores and loads
927
928ftree-ch
929Common Report Var(flag_tree_ch)
930Enable loop header copying on trees
931
932ftree-combine-temps
933Common Report Var(flag_tree_combine_temps)
934Coalesce memory temporaries in the SSA->normal pass
935
936ftree-copyrename
937Common Report Var(flag_tree_copyrename)
938Replace SSA temporaries with better names in copies
939
940ftree-copy-prop
941Common Report Var(flag_tree_copy_prop)
942Enable copy propagation on trees
943
944ftree-store-copy-prop
945Common Report Var(flag_tree_store_copy_prop)
946Enable copy propagation for stores and loads
947
948ftree-dce
949Common Report Var(flag_tree_dce)
950Enable SSA dead code elimination optimization on trees
951
952ftree-dominator-opts
953Common Report Var(flag_tree_dom)
954Enable dominator optimizations
955
956ftree-dse
957Common Report Var(flag_tree_dse)
958Enable dead store elimination
959
960ftree-fre
961Common Report Var(flag_tree_fre)
962Enable Full Redundancy Elimination (FRE) on trees
963
964ftree-loop-im
965Common Report Var(flag_tree_loop_im) Init(1)
966Enable loop invariant motion on trees
967
968ftree-loop-linear
969Common Report Var(flag_tree_loop_linear)
970Enable linear loop transforms on trees
971
972ftree-loop-ivcanon
973Common Report Var(flag_tree_loop_ivcanon) Init(1)
974Create canonical induction variables in loops
975
976ftree-loop-optimize
977Common Report Var(flag_tree_loop_optimize) Init(1)
978Enable loop optimizations on tree level
979
980ftree-pre
981Common Report Var(flag_tree_pre)
982Enable SSA-PRE optimization on trees
983
984ftree-salias
985Common Report Var(flag_tree_salias)
986Perform structural alias analysis
987
988ftree-sink
989Common Report Var(flag_tree_sink)
990Enable SSA code sinking on trees
991
992ftree-sra
993Common Report Var(flag_tree_sra)
994Perform scalar replacement of aggregates
995
996ftree-ter
997Common Report Var(flag_tree_ter)
998Replace temporary expressions in the SSA->normal pass
999
1000ftree-lrs
1001Common Report Var(flag_tree_live_range_split)
1002Perform live range splitting during the SSA->normal pass
1003
1004ftree-vrp
1005Common Report Var(flag_tree_vrp) Init(0)
1006Perform Value Range Propagation on trees
1007
1008funit-at-a-time
1009Common Report Var(flag_unit_at_a_time)
1010Compile whole compilation unit at a time
1011
1012funroll-loops
1013Common Report Var(flag_unroll_loops)
1014Perform loop unrolling when iteration count is known
1015
1016funroll-all-loops
1017Common Report Var(flag_unroll_all_loops)
1018Perform loop unrolling for all loops
1019
1020; Nonzero means that loop optimizer may assume that the induction variables
1021; that control loops do not overflow and that the loops with nontrivial
1022; exit condition are not infinite
1023funsafe-loop-optimizations
1024Common Report Var(flag_unsafe_loop_optimizations)
1025Allow loop optimizations to assume that the loops behave in normal way
1026
1027; Nonzero means that unsafe floating-point math optimizations are allowed
1028; for the sake of speed.  IEEE compliance is not guaranteed, and operations
1029; are allowed to assume that their arguments and results are "normal"
1030; (e.g., nonnegative for SQRT).
1031funsafe-math-optimizations
1032Common Report Var(flag_unsafe_math_optimizations)
1033Allow math optimizations that may violate IEEE or ISO standards
1034
1035funswitch-loops
1036Common Report Var(flag_unswitch_loops)
1037Perform loop unswitching
1038
1039funwind-tables
1040Common Report Var(flag_unwind_tables)
1041Just generate unwind tables for exception handling
1042
1043fvar-tracking
1044Common Report Var(flag_var_tracking) VarExists
1045Perform variable tracking
1046
1047ftree-vectorize
1048Common Report Var(flag_tree_vectorize)
1049Enable loop vectorization on trees
1050
1051ftree-vect-loop-version
1052Common Report Var(flag_tree_vect_loop_version) Init(1)
1053Enable loop versioning when doing loop vectorization on trees
1054
1055ftree-vectorizer-verbose=
1056Common RejectNegative Joined
1057-ftree-vectorizer-verbose=<number>	Set the verbosity level of the vectorizer
1058
1059; -fverbose-asm causes extra commentary information to be produced in
1060; the generated assembly code (to make it more readable).  This option
1061; is generally only of use to those who actually need to read the
1062; generated assembly code (perhaps while debugging the compiler itself).
1063; -fno-verbose-asm, the default, causes the extra information
1064; to not be added and is useful when comparing two assembler files.
1065fverbose-asm
1066Common Report Var(flag_verbose_asm)
1067Add extra commentary to assembler output
1068
1069fvisibility=
1070Common Joined RejectNegative
1071-fvisibility=[default|internal|hidden|protected]	Set the default symbol visibility
1072
1073
1074fvpt
1075Common Report Var(flag_value_profile_transformations)
1076Use expression value profiles in optimizations
1077
1078fweb
1079Common Report Var(flag_web) Init(2)
1080Construct webs and split unrelated uses of single variable
1081
1082fwhole-program
1083Common Report Var(flag_whole_program) Init(0)
1084Perform whole program optimizations
1085
1086fwrapv
1087Common Report Var(flag_wrapv)
1088Assume signed arithmetic overflow wraps around
1089
1090fzero-initialized-in-bss
1091Common Report Var(flag_zero_initialized_in_bss) Init(1)
1092Put zero initialized data in the bss section
1093
1094g
1095Common JoinedOrMissing
1096Generate debug information in default format
1097
1098gcoff
1099Common JoinedOrMissing Negative(gdwarf-2)
1100Generate debug information in COFF format
1101
1102gdwarf-2
1103Common JoinedOrMissing Negative(gstabs)
1104Generate debug information in DWARF v2 format
1105
1106ggdb
1107Common JoinedOrMissing
1108Generate debug information in default extended format
1109
1110gstabs
1111Common JoinedOrMissing Negative(gstabs+)
1112Generate debug information in STABS format
1113
1114gstabs+
1115Common JoinedOrMissing Negative(gvms)
1116Generate debug information in extended STABS format
1117
1118gvms
1119Common JoinedOrMissing Negative(gxcoff)
1120Generate debug information in VMS format
1121
1122gxcoff
1123Common JoinedOrMissing Negative(gxcoff+)
1124Generate debug information in XCOFF format
1125
1126gxcoff+
1127Common JoinedOrMissing Negative(gcoff)
1128Generate debug information in extended XCOFF format
1129
1130o
1131Common Joined Separate
1132-o <file>	Place output into <file>
1133
1134p
1135Common Var(profile_flag)
1136Enable function profiling
1137
1138pedantic
1139Common Var(pedantic)
1140Issue warnings needed for strict compliance to the standard
1141
1142pedantic-errors
1143Common
1144Like -pedantic but issue them as errors
1145
1146quiet
1147Common Var(quiet_flag)
1148Do not display functions compiled or elapsed time
1149
1150version
1151Common Var(version_flag)
1152Display the compiler's version
1153
1154w
1155Common Var(inhibit_warnings)
1156Suppress warnings
1157
1158; This comment is to ensure we retain the blank line above.
1159