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
192Wvariable-decl
193Common Var(warn_variable_decl)
194Warn about variable-sized declarations.
195
196Wvolatile-register-var
197Common Var(warn_register_var)
198Warn when a register variable is declared volatile
199
200aux-info
201Common Separate
202-aux-info <file>	Emit declaration information into <file>
203
204aux-info=
205Common Joined
206
207auxbase
208Common Separate
209
210auxbase-strip
211Common Separate
212
213d
214Common Joined
215-d<letters>	Enable dumps from specific passes of the compiler
216
217dumpbase
218Common Separate
219-dumpbase <file>	Set the file basename to be used for dumps
220
221; The version of the C++ ABI in use.  The following values are allowed:
222;
223; 0: The version of the ABI believed most conformant with the C++ ABI
224;    specification.  This ABI may change as bugs are discovered and fixed.
225;    Therefore, 0 will not necessarily indicate the same ABI in different
226;    versions of G++.
227;
228; 1: The version of the ABI first used in G++ 3.2.
229;
230; Additional positive integers will be assigned as new versions of
231; the ABI become the default version of the ABI.
232fabi-version=
233Common Joined UInteger Var(flag_abi_version) Init(2)
234
235falign-functions
236Common Report Var(align_functions,0)
237Align the start of functions
238
239falign-functions=
240Common RejectNegative Joined UInteger
241
242falign-jumps
243Common Report Var(align_jumps,0)
244Align labels which are only reached by jumping
245
246falign-jumps=
247Common RejectNegative Joined UInteger
248
249falign-labels
250Common Report Var(align_labels,0)
251Align all labels
252
253falign-labels=
254Common RejectNegative Joined UInteger
255
256falign-loops
257Common Report Var(align_loops)
258Align the start of loops
259
260falign-loops=
261Common RejectNegative Joined UInteger
262
263; This flag is only tested if alias checking is enabled.
264; 0 if pointer arguments may alias each other.  True in C.
265; 1 if pointer arguments may not alias each other but may alias
266;   global variables.
267; 2 if pointer arguments may not alias each other and may not
268;   alias global variables.
269; 3 if pointer arguments may not alias anything.  True in Fortran.
270;   Set by the front end.
271fargument-alias
272Common Report Var(flag_argument_noalias,0)
273Specify that arguments may alias each other and globals
274
275fargument-noalias
276Common Report Var(flag_argument_noalias,1) VarExists
277Assume arguments may alias globals but not each other
278
279fargument-noalias-global
280Common Report Var(flag_argument_noalias,2) VarExists
281Assume arguments alias neither each other nor globals
282
283fargument-noalias-anything
284Common Report Var(flag_argument_noalias,3) VarExists
285Assume arguments alias no other storage
286
287fasynchronous-unwind-tables
288Common Report Var(flag_asynchronous_unwind_tables)
289Generate unwind tables that are exact at each instruction boundary
290
291; -fcheck-bounds causes gcc to generate array bounds checks.
292; For C, C++ and ObjC: defaults off.
293; For Java: defaults to on.
294; For Fortran: defaults to off.
295fbounds-check
296Common Report Var(flag_bounds_check)
297Generate code to check bounds before indexing arrays
298
299fbranch-count-reg
300Common Report Var(flag_branch_on_count_reg) Init(1)
301Replace add, compare, branch with branch on count register
302
303fbranch-probabilities
304Common Report Var(flag_branch_probabilities)
305Use profiling information for branch probabilities
306
307fbranch-target-load-optimize
308Common Report Var(flag_branch_target_load_optimize)
309Perform branch target load optimization before prologue / epilogue threading
310
311fbranch-target-load-optimize2
312Common Report Var(flag_branch_target_load_optimize2)
313Perform branch target load optimization after prologue / epilogue threading
314
315fbtr-bb-exclusive
316Common Report Var(flag_btr_bb_exclusive)
317Restrict target load migration not to re-use registers in any basic block
318
319fcall-saved-
320Common Joined RejectNegative
321-fcall-saved-<register>	Mark <register> as being preserved across functions
322
323fcall-used-
324Common Joined RejectNegative
325-fcall-used-<register>	Mark <register> as being corrupted by function calls
326
327; Nonzero for -fcaller-saves: allocate values in regs that need to
328; be saved across function calls, if that produces overall better code.
329; Optional now, so people can test it.
330fcaller-saves
331Common Report Var(flag_caller_saves)
332Save registers around function calls
333
334fcommon
335Common Report Var(flag_no_common,0)
336Do not put uninitialized globals in the common section
337
338fcprop-registers
339Common Report Var(flag_cprop_registers)
340Perform a register copy-propagation optimization pass
341
342fcrossjumping
343Common Report Var(flag_crossjumping)
344Perform cross-jumping optimization
345
346fcse-follow-jumps
347Common Report Var(flag_cse_follow_jumps)
348When running CSE, follow jumps to their targets
349
350fcse-skip-blocks
351Common Report Var(flag_cse_skip_blocks)
352When running CSE, follow conditional jumps
353
354fcx-limited-range
355Common Report Var(flag_cx_limited_range)
356Omit range reduction step when performing complex division
357
358fdata-sections
359Common Report Var(flag_data_sections)
360Place data items into their own section
361
362; Nonzero for -fdefer-pop: don't pop args after each function call
363; instead save them up to pop many calls' args with one insns.
364fdefer-pop
365Common Report Var(flag_defer_pop)
366Defer popping functions args from stack until later
367
368fdelayed-branch
369Common Report Var(flag_delayed_branch)
370Attempt to fill delay slots of branch instructions
371
372fdelete-null-pointer-checks
373Common Report Var(flag_delete_null_pointer_checks)
374Delete useless null pointer checks
375
376fdiagnostics-show-location=
377Common Joined RejectNegative
378-fdiagnostics-show-location=[once|every-line]	How often to emit source location at the beginning of line-wrapped diagnostics
379
380fdiagnostics-show-option
381Common
382Amend appropriate diagnostic messages with the command line option that controls them
383
384fdump-
385Common Joined RejectNegative
386-fdump-<type>	Dump various compiler internals to a file
387
388fdump-noaddr
389Common Report Var(flag_dump_noaddr)
390Suppress output of addresses in debugging dumps
391
392fdump-unnumbered
393Common Report Var(flag_dump_unnumbered) VarExists
394Suppress output of instruction numbers, line number notes and addresses in debugging dumps
395
396fearly-inlining
397Common Report Var(flag_early_inlining) Init(1)
398Perform early inlining
399
400feliminate-dwarf2-dups
401Common Report Var(flag_eliminate_dwarf2_dups)
402Perform DWARF2 duplicate elimination
403
404feliminate-unused-debug-symbols
405Common Report Var(flag_debug_only_used_symbols)
406Perform unused type elimination in debug info
407
408feliminate-unused-debug-types
409Common Report Var(flag_eliminate_unused_debug_types) Init(1)
410Perform unused type elimination in debug info
411
412femit-class-debug-always
413Common Report Var(flag_emit_class_debug_always) Init(1)
414Do not suppress C++ class debug information.
415
416fexceptions
417Common Report Var(flag_exceptions)
418Enable exception handling
419
420fexpensive-optimizations
421Common Report Var(flag_expensive_optimizations)
422Perform a number of minor, expensive optimizations
423
424ffast-math
425Common
426
427ffinite-math-only
428Common Report Var(flag_finite_math_only)
429Assume no NaNs or infinities are generated
430
431ffixed-
432Common Joined RejectNegative
433-ffixed-<register>	Mark <register> as being unavailable to the compiler
434
435ffloat-store
436Common Report Var(flag_float_store)
437Don't allocate floats and doubles in extended-precision registers
438
439; Nonzero for -fforce-addr: load memory address into a register before
440; reference to memory.  This makes better cse but slower compilation.
441fforce-addr
442Common Report Var(flag_force_addr)
443Copy memory address constants into registers before use
444
445; Nonzero for -fforce-mem: load memory value into a register
446; before arithmetic on it.  This makes better cse but slower compilation.
447fforce-mem
448Common Report Var(flag_force_mem)
449Copy memory operands into registers before use
450
451; Nonzero means don't put addresses of constant functions in registers.
452; Used for compiling the Unix kernel, where strange substitutions are
453; done on the assembly output.
454ffunction-cse
455Common Report Var(flag_no_function_cse,0)
456Allow function addresses to be held in registers
457
458ffunction-sections
459Common Report Var(flag_function_sections)
460Place each function into its own section
461
462fgcse
463Common Report Var(flag_gcse)
464Perform global common subexpression elimination
465
466fgcse-lm
467Common Report Var(flag_gcse_lm) Init(1)
468Perform enhanced load motion during global common subexpression elimination
469
470fgcse-sm
471Common Report Var(flag_gcse_sm) Init(0)
472Perform store motion after global common subexpression elimination
473
474fgcse-las
475Common Report Var(flag_gcse_las) Init(0)
476Perform redundant load after store elimination in global common subexpression
477elimination
478
479fgcse-after-reload
480Common Report Var(flag_gcse_after_reload)
481Perform global common subexpression elimination after register allocation
482has finished
483
484fguess-branch-probability
485Common Report Var(flag_guess_branch_prob)
486Enable guessing of branch probabilities
487
488; Nonzero means ignore `#ident' directives.  0 means handle them.
489; Generate position-independent code for executables if possible
490; On SVR4 targets, it also controls whether or not to emit a
491; string identifying the compiler.
492fident
493Common Report Var(flag_no_ident,0)
494Process #ident directives
495
496fif-conversion
497Common Report Var(flag_if_conversion)
498Perform conversion of conditional jumps to branchless equivalents
499
500fif-conversion2
501Common Report Var(flag_if_conversion2)
502Perform conversion of conditional jumps to conditional execution
503
504; -finhibit-size-directive inhibits output of .size for ELF.
505; This is used only for compiling crtstuff.c,
506; and it may be extended to other effects
507; needed for crtstuff.c on other systems.
508finhibit-size-directive
509Common Report Var(flag_inhibit_size_directive)
510Do not generate .size directives
511
512; Nonzero means that functions declared `inline' will be treated
513; as `static'.  Prevents generation of zillions of copies of unused
514; static inline functions; instead, `inlines' are written out
515; only when actually used.  Used in conjunction with -g.  Also
516; does the right thing with #pragma interface.
517finline
518Common Report Var(flag_no_inline,0) Init(2)
519Pay attention to the \"inline\" keyword
520
521finline-functions
522Common Report Var(flag_inline_functions)
523Integrate simple functions into their callers
524
525finline-functions-called-once
526Common Report Var(flag_inline_functions_called_once) Init(1)
527Integrate functions called once into their callers
528
529finline-limit-
530Common RejectNegative Joined UInteger
531
532finline-limit=
533Common RejectNegative Joined UInteger
534-finline-limit=<number>	Limit the size of inlined functions to <number>
535
536finstrument-functions
537Common Report Var(flag_instrument_function_entry_exit)
538Instrument function entry and exit with profiling calls
539
540fipa-cp
541Common Report Var(flag_ipa_cp)
542Perform Interprocedural constant propagation
543
544fipa-pure-const
545Common Report Var(flag_ipa_pure_const) Init(0)
546Discover pure and const functions
547
548fipa-pta
549Common Report Var(flag_ipa_pta) Init(0)
550Perform interprocedural points-to analysis
551
552fipa-reference
553Common Report Var(flag_ipa_reference) Init(0)
554Discover readonly and non addressable static variables
555
556fipa-type-escape
557Common Report Var(flag_ipa_type_escape) Init(0)
558Type based escape and alias analysis
559
560fivopts
561Common Report Var(flag_ivopts) Init(1)
562Optimize induction variables on trees
563
564fjump-tables
565Common Var(flag_jump_tables) Init(1)
566Use jump tables for sufficiently large switch statements
567
568fkeep-inline-functions
569Common Report Var(flag_keep_inline_functions)
570Generate code for functions even if they are fully inlined
571
572fkeep-static-consts
573Common Report Var(flag_keep_static_consts) Init(1)
574Emit static const variables even if they are not used
575
576fleading-underscore
577Common Report Var(flag_leading_underscore) Init(-1)
578Give external symbols a leading underscore
579
580floop-optimize
581Common
582Does nothing.  Preserved for backward compatibility.
583
584fmath-errno
585Common Report Var(flag_errno_math) Init(0)
586Set errno after built-in math functions
587
588fmem-report
589Common Report Var(mem_report)
590Report on permanent memory allocation
591
592; This will attempt to merge constant section constants, if 1 only
593; string constants and constants from constant pool, if 2 also constant
594; variables.
595fmerge-all-constants
596Common Report Var(flag_merge_constants,2) Init(1)
597Attempt to merge identical constants and constant variables
598
599fmerge-constants
600Common Report Var(flag_merge_constants,1) VarExists
601Attempt to merge identical constants across compilation units
602
603fmessage-length=
604Common RejectNegative Joined UInteger
605-fmessage-length=<number>	Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping
606
607fmodulo-sched
608Common Report Var(flag_modulo_sched)
609Perform SMS based modulo scheduling before the first scheduling pass
610
611fmove-loop-invariants
612Common Report Var(flag_move_loop_invariants) Init(1)
613Move loop invariant computations out of loops
614
615fmudflap
616Common RejectNegative Report Var(flag_mudflap)
617Add mudflap bounds-checking instrumentation for single-threaded program
618
619fmudflapth
620Common RejectNegative Report VarExists Var(flag_mudflap,2)
621Add mudflap bounds-checking instrumentation for multi-threaded program
622
623fmudflapir
624Common RejectNegative Report Var(flag_mudflap_ignore_reads)
625Ignore read operations when inserting mudflap instrumentation
626
627freschedule-modulo-scheduled-loops
628Common Report Var(flag_resched_modulo_sched)
629Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
630
631fnon-call-exceptions
632Common Report Var(flag_non_call_exceptions)
633Support synchronous non-call exceptions
634
635fomit-frame-pointer
636Common Report Var(flag_omit_frame_pointer)
637When possible do not generate stack frames
638
639foptimize-register-move
640Common Report Var(flag_regmove)
641Do the full register move optimization pass
642
643foptimize-sibling-calls
644Common Report Var(flag_optimize_sibling_calls)
645Optimize sibling and tail recursive calls
646
647fpack-struct
648Common Report Var(flag_pack_struct)
649Pack structure members together without holes
650
651fpack-struct=
652Common RejectNegative Joined UInteger
653-fpack-struct=<number>	Set initial maximum structure member alignment
654
655fpcc-struct-return
656Common Report Var(flag_pcc_struct_return,1) VarExists
657Return small aggregates in memory, not registers
658
659fpeel-loops
660Common Report Var(flag_peel_loops)
661Perform loop peeling
662
663fpeephole
664Common Report Var(flag_no_peephole,0)
665Enable machine specific peephole optimizations
666
667fpeephole2
668Common Report Var(flag_peephole2)
669Enable an RTL peephole pass before sched2
670
671fPIC
672Common Report Var(flag_pic,2)
673Generate position-independent code if possible (large mode)
674
675fPIE
676Common Report Var(flag_pie,2)
677Generate position-independent code for executables if possible (large mode)
678
679fpic
680Common Report Var(flag_pic,1) VarExists
681Generate position-independent code if possible (small mode)
682
683fpie
684Common Report Var(flag_pie,1) VarExists
685Generate position-independent code for executables if possible (small mode)
686
687fprefetch-loop-arrays
688Common Report Var(flag_prefetch_loop_arrays)
689Generate prefetch instructions, if available, for arrays in loops
690
691fprofile
692Common Report Var(profile_flag)
693Enable basic program profiling code
694
695fprofile-arcs
696Common Report Var(profile_arc_flag)
697Insert arc-based program profiling code
698
699fprofile-generate
700Common
701Enable common options for generating profile info for profile feedback directed optimizations
702
703fprofile-use
704Common
705Enable common options for performing profile feedback directed optimizations
706
707fprofile-values
708Common Report Var(flag_profile_values)
709Insert code to profile values of expressions
710
711frandom-seed
712Common
713
714frandom-seed=
715Common Joined RejectNegative
716-frandom-seed=<string>	Make compile reproducible using <string>
717
718freg-struct-return
719Common Report Var(flag_pcc_struct_return,0) VarExists
720Return small aggregates in registers
721
722fregmove
723Common Report Var(flag_regmove)
724Enables a register move optimization
725
726frename-registers
727Common Report Var(flag_rename_registers) Init(2)
728Perform a register renaming optimization pass
729
730freorder-blocks
731Common Report Var(flag_reorder_blocks)
732Reorder basic blocks to improve code placement
733
734freorder-blocks-and-partition
735Common Report Var(flag_reorder_blocks_and_partition)
736Reorder basic blocks and partition into hot and cold sections
737
738freorder-functions
739Common Report Var(flag_reorder_functions)
740Reorder functions to improve code placement
741
742frerun-cse-after-loop
743Common Report Var(flag_rerun_cse_after_loop) Init(2)
744Add a common subexpression elimination pass after loop optimizations
745
746frerun-loop-opt
747Common
748Does nothing.  Preserved for backward compatibility.
749
750frounding-math
751Common Report Var(flag_rounding_math)
752Disable optimizations that assume default FP rounding behavior
753
754fsched-interblock
755Common Report Var(flag_schedule_interblock) Init(1)
756Enable scheduling across basic blocks
757
758fsched-spec
759Common Report Var(flag_schedule_speculative) Init(1)
760Allow speculative motion of non-loads
761
762fsched-spec-load
763Common Report Var(flag_schedule_speculative_load)
764Allow speculative motion of some loads
765
766fsched-spec-load-dangerous
767Common Report Var(flag_schedule_speculative_load_dangerous)
768Allow speculative motion of more loads
769
770fsched-verbose=
771Common RejectNegative Joined
772-fsched-verbose=<number>	Set the verbosity level of the scheduler
773
774fsched2-use-superblocks
775Common Report Var(flag_sched2_use_superblocks)
776If scheduling post reload, do superblock scheduling
777
778fsched2-use-traces
779Common Report Var(flag_sched2_use_traces)
780If scheduling post reload, do trace scheduling
781
782fschedule-insns
783Common Report Var(flag_schedule_insns)
784Reschedule instructions before register allocation
785
786fschedule-insns2
787Common Report Var(flag_schedule_insns_after_reload)
788Reschedule instructions after register allocation
789
790; sched_stalled_insns means that insns can be moved prematurely from the queue
791; of stalled insns into the ready list.
792fsched-stalled-insns
793Common Report Var(flag_sched_stalled_insns)
794Allow premature scheduling of queued insns
795
796fsched-stalled-insns=
797Common RejectNegative Joined UInteger
798-fsched-stalled-insns=<number>	Set number of queued insns that can be prematurely scheduled
799
800; sched_stalled_insns_dep controls how many recently scheduled cycles will
801; be examined for a dependency on a stalled insn that is candidate for
802; premature removal from the queue of stalled insns into the ready list (has
803; an effect only if the flag 'sched_stalled_insns' is set).
804fsched-stalled-insns-dep
805Common Report Var(flag_sched_stalled_insns_dep,1) Init(1)
806Set dependence distance checking in premature scheduling of queued insns
807
808fsched-stalled-insns-dep=
809Common RejectNegative Joined UInteger
810-fsched-stalled-insns-dep=<number>	Set dependence distance checking in premature scheduling of queued insns
811
812fsection-anchors
813Common Report Var(flag_section_anchors)
814Access data in the same section from shared anchor points
815
816frtl-abstract-sequences
817Common Report Var(flag_rtl_seqabstr)
818Perform sequence abstraction optimization on RTL
819
820fsee
821Common Report Var(flag_see) Init(0)
822Eliminate redundant sign extensions using LCM.
823
824fshow-column
825Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(1)
826Show column numbers in diagnostics, when available.  Default on
827
828fsignaling-nans
829Common Report Var(flag_signaling_nans)
830Disable optimizations observable by IEEE signaling NaNs
831
832fsingle-precision-constant
833Common Report Var(flag_single_precision_constant)
834Convert floating point constants to single precision constants
835
836fsplit-ivs-in-unroller
837Common Report Var(flag_split_ivs_in_unroller) Init(1)
838Split lifetimes of induction variables when loops are unrolled
839
840fvariable-expansion-in-unroller
841Common Report Var(flag_variable_expansion_in_unroller)
842Apply variable expansion when loops are unrolled
843
844; Emit code to probe the stack, to help detect stack overflow; also
845; may cause large objects to be allocated dynamically.
846fstack-check
847Common Report Var(flag_stack_check)
848Insert stack checking code into the program
849
850fstack-limit
851Common
852
853fstack-limit-register=
854Common RejectNegative Joined
855-fstack-limit-register=<register>	Trap if the stack goes past <register>
856
857fstack-limit-symbol=
858Common RejectNegative Joined
859-fstack-limit-symbol=<name>	Trap if the stack goes past symbol <name>
860
861fstack-protector
862Common Report Var(flag_stack_protect, 1)
863Use propolice as a stack protection method
864
865fstack-protector-all
866Common Report RejectNegative Var(flag_stack_protect, 2) VarExists
867Use a stack protection method for every function
868
869fstrength-reduce
870Common
871Does nothing.  Preserved for backward compatibility.
872
873; Nonzero if we should do (language-dependent) alias analysis.
874; Typically, this analysis will assume that expressions of certain
875; types do not alias expressions of certain other types.  Only used
876; if alias analysis (in general) is enabled.
877fstrict-aliasing
878Common Report Var(flag_strict_aliasing)
879Assume strict aliasing rules apply
880
881fstrict-overflow
882Common Report Var(flag_strict_overflow)
883Treat signed overflow as undefined
884
885fsyntax-only
886Common Report Var(flag_syntax_only)
887Check for syntax errors, then stop
888
889ftest-coverage
890Common Report Var(flag_test_coverage)
891Create data files needed by \"gcov\"
892
893fthread-jumps
894Common Report Var(flag_thread_jumps)
895Perform jump threading optimizations
896
897ftime-report
898Common Report Var(time_report)
899Report the time taken by each compiler pass
900
901ftls-model=
902Common Joined RejectNegative
903-ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]	Set the default thread-local storage code generation model
904
905ftoplevel-reorder
906Common Report Var(flag_toplevel_reorder) Init(1)
907Reorder top level functions, variables, and asms
908
909ftracer
910Common Report Var(flag_tracer)
911Perform superblock formation via tail duplication
912
913; Zero means that floating-point math operations cannot generate a
914; (user-visible) trap.  This is the case, for example, in nonstop
915; IEEE 754 arithmetic.
916ftrapping-math
917Common Report Var(flag_trapping_math) Init(1)
918Assume floating-point operations can trap
919
920ftrapv
921Common Report Var(flag_trapv)
922Trap for signed overflow in addition, subtraction and multiplication
923
924ftree-ccp
925Common Report Var(flag_tree_ccp)
926Enable SSA-CCP optimization on trees
927
928ftree-store-ccp
929Common Report Var(flag_tree_store_ccp)
930Enable SSA-CCP optimization for stores and loads
931
932ftree-ch
933Common Report Var(flag_tree_ch)
934Enable loop header copying on trees
935
936ftree-combine-temps
937Common Report Var(flag_tree_combine_temps)
938Coalesce memory temporaries in the SSA->normal pass
939
940ftree-copyrename
941Common Report Var(flag_tree_copyrename)
942Replace SSA temporaries with better names in copies
943
944ftree-copy-prop
945Common Report Var(flag_tree_copy_prop)
946Enable copy propagation on trees
947
948ftree-store-copy-prop
949Common Report Var(flag_tree_store_copy_prop)
950Enable copy propagation for stores and loads
951
952ftree-dce
953Common Report Var(flag_tree_dce)
954Enable SSA dead code elimination optimization on trees
955
956ftree-dominator-opts
957Common Report Var(flag_tree_dom)
958Enable dominator optimizations
959
960ftree-dse
961Common Report Var(flag_tree_dse)
962Enable dead store elimination
963
964ftree-fre
965Common Report Var(flag_tree_fre)
966Enable Full Redundancy Elimination (FRE) on trees
967
968ftree-loop-im
969Common Report Var(flag_tree_loop_im) Init(1)
970Enable loop invariant motion on trees
971
972ftree-loop-linear
973Common Report Var(flag_tree_loop_linear)
974Enable linear loop transforms on trees
975
976ftree-loop-ivcanon
977Common Report Var(flag_tree_loop_ivcanon) Init(1)
978Create canonical induction variables in loops
979
980ftree-loop-optimize
981Common Report Var(flag_tree_loop_optimize) Init(1)
982Enable loop optimizations on tree level
983
984ftree-pre
985Common Report Var(flag_tree_pre)
986Enable SSA-PRE optimization on trees
987
988ftree-salias
989Common Report Var(flag_tree_salias)
990Perform structural alias analysis
991
992ftree-sink
993Common Report Var(flag_tree_sink)
994Enable SSA code sinking on trees
995
996ftree-sra
997Common Report Var(flag_tree_sra)
998Perform scalar replacement of aggregates
999
1000ftree-ter
1001Common Report Var(flag_tree_ter)
1002Replace temporary expressions in the SSA->normal pass
1003
1004ftree-lrs
1005Common Report Var(flag_tree_live_range_split)
1006Perform live range splitting during the SSA->normal pass
1007
1008ftree-vrp
1009Common Report Var(flag_tree_vrp) Init(0)
1010Perform Value Range Propagation on trees
1011
1012funit-at-a-time
1013Common Report Var(flag_unit_at_a_time)
1014Compile whole compilation unit at a time
1015
1016funroll-loops
1017Common Report Var(flag_unroll_loops)
1018Perform loop unrolling when iteration count is known
1019
1020funroll-all-loops
1021Common Report Var(flag_unroll_all_loops)
1022Perform loop unrolling for all loops
1023
1024; Nonzero means that loop optimizer may assume that the induction variables
1025; that control loops do not overflow and that the loops with nontrivial
1026; exit condition are not infinite
1027funsafe-loop-optimizations
1028Common Report Var(flag_unsafe_loop_optimizations)
1029Allow loop optimizations to assume that the loops behave in normal way
1030
1031; Nonzero means that unsafe floating-point math optimizations are allowed
1032; for the sake of speed.  IEEE compliance is not guaranteed, and operations
1033; are allowed to assume that their arguments and results are "normal"
1034; (e.g., nonnegative for SQRT).
1035funsafe-math-optimizations
1036Common Report Var(flag_unsafe_math_optimizations)
1037Allow math optimizations that may violate IEEE or ISO standards
1038
1039funswitch-loops
1040Common Report Var(flag_unswitch_loops)
1041Perform loop unswitching
1042
1043funwind-tables
1044Common Report Var(flag_unwind_tables)
1045Just generate unwind tables for exception handling
1046
1047fvar-tracking
1048Common Report Var(flag_var_tracking) VarExists
1049Perform variable tracking
1050
1051ftree-vectorize
1052Common Report Var(flag_tree_vectorize)
1053Enable loop vectorization on trees
1054
1055ftree-vect-loop-version
1056Common Report Var(flag_tree_vect_loop_version) Init(1)
1057Enable loop versioning when doing loop vectorization on trees
1058
1059ftree-vectorizer-verbose=
1060Common RejectNegative Joined
1061-ftree-vectorizer-verbose=<number>	Set the verbosity level of the vectorizer
1062
1063; -fverbose-asm causes extra commentary information to be produced in
1064; the generated assembly code (to make it more readable).  This option
1065; is generally only of use to those who actually need to read the
1066; generated assembly code (perhaps while debugging the compiler itself).
1067; -fno-verbose-asm, the default, causes the extra information
1068; to not be added and is useful when comparing two assembler files.
1069fverbose-asm
1070Common Report Var(flag_verbose_asm)
1071Add extra commentary to assembler output
1072
1073fvisibility=
1074Common Joined RejectNegative
1075-fvisibility=[default|internal|hidden|protected]	Set the default symbol visibility
1076
1077
1078fvpt
1079Common Report Var(flag_value_profile_transformations)
1080Use expression value profiles in optimizations
1081
1082fweb
1083Common Report Var(flag_web) Init(2)
1084Construct webs and split unrelated uses of single variable
1085
1086fwhole-program
1087Common Report Var(flag_whole_program) Init(0)
1088Perform whole program optimizations
1089
1090fwrapv
1091Common Report Var(flag_wrapv)
1092Assume signed arithmetic overflow wraps around
1093
1094fzero-initialized-in-bss
1095Common Report Var(flag_zero_initialized_in_bss) Init(1)
1096Put zero initialized data in the bss section
1097
1098g
1099Common JoinedOrMissing
1100Generate debug information in default format
1101
1102gcoff
1103Common JoinedOrMissing Negative(gdwarf-2)
1104Generate debug information in COFF format
1105
1106gdwarf-2
1107Common JoinedOrMissing Negative(gstabs)
1108Generate debug information in DWARF v2 format
1109
1110ggdb
1111Common JoinedOrMissing
1112Generate debug information in default extended format
1113
1114gstabs
1115Common JoinedOrMissing Negative(gstabs+)
1116Generate debug information in STABS format
1117
1118gstabs+
1119Common JoinedOrMissing Negative(gvms)
1120Generate debug information in extended STABS format
1121
1122gvms
1123Common JoinedOrMissing Negative(gxcoff)
1124Generate debug information in VMS format
1125
1126gxcoff
1127Common JoinedOrMissing Negative(gxcoff+)
1128Generate debug information in XCOFF format
1129
1130gxcoff+
1131Common JoinedOrMissing Negative(gcoff)
1132Generate debug information in extended XCOFF format
1133
1134o
1135Common Joined Separate
1136-o <file>	Place output into <file>
1137
1138p
1139Common Var(profile_flag)
1140Enable function profiling
1141
1142pedantic
1143Common Var(pedantic)
1144Issue warnings needed for strict compliance to the standard
1145
1146pedantic-errors
1147Common
1148Like -pedantic but issue them as errors
1149
1150quiet
1151Common Var(quiet_flag)
1152Do not display functions compiled or elapsed time
1153
1154version
1155Common Var(version_flag)
1156Display the compiler's version
1157
1158w
1159Common Var(inhibit_warnings)
1160Suppress warnings
1161
1162; This comment is to ensure we retain the blank line above.
1163