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Extend DCE to remove unnecessary new/delete-pairs (PR c++/23383).
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1 ; Options for the language- and target-independent parts of the compiler.
2
3 ; Copyright (C) 2003-2019 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 3, 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 COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
20
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
22
23 ; Please try to keep this file in ASCII collating order.
24
25 Variable
26 int target_flags
27
28 Variable
29 int optimize
30
31 Variable
32 int optimize_size
33
34 Variable
35 int optimize_debug
36
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
39 Variable
40 int optimize_fast
41
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
46 Variable
47 bool in_lto_p = false
48
49 ; This variable is set to non-0 only by LTO front-end. 1 indicates that
50 ; the output produced will be used for incrmeental linking (thus weak symbols
51 ; can still be bound) and 2 indicates that the IL is going to be linked and
52 ; and output to LTO object file.
53 Variable
54 enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE
55
56 ; 0 means straightforward implementation of complex divide acceptable.
57 ; 1 means wide ranges of inputs must work for complex divide.
58 ; 2 means C99-like requirements for complex multiply and divide.
59 Variable
60 int flag_complex_method = 1
61
62 ; Language specific warning pass for unused results.
63 Variable
64 bool flag_warn_unused_result = false
65
66 Variable
67 int *param_values
68
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
70 Variable
71 int flag_generate_lto
72
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
74 Variable
75 int flag_generate_offload = 0
76
77 ; Nonzero means we should be saving declaration info into a .X file.
78 Variable
79 int flag_gen_aux_info = 0
80
81 ; Nonzero if we are compiling code for a shared library, zero for
82 ; executable.
83 Variable
84 int flag_shlib
85
86 ; These two are really VEC(char_p,heap) *.
87
88 Variable
89 void *flag_instrument_functions_exclude_functions
90
91 Variable
92 void *flag_instrument_functions_exclude_files
93
94 ; Generic structs (e.g. templates not explicitly specialized)
95 ; may not have a compilation unit associated with them, and so
96 ; may need to be treated differently from ordinary structs.
97 ;
98 ; Structs only handled by reference (indirectly), will also usually
99 ; not need as much debugging information.
100
101 Variable
102 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
103
104 Variable
105 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
106
107 ; True if we should exit after parsing options.
108 Variable
109 bool exit_after_options
110
111 ; Type(s) of debugging information we are producing (if any). See
112 ; flag-types.h for the definitions of the different possible types of
113 ; debugging information.
114 Variable
115 enum debug_info_type write_symbols = NO_DEBUG
116
117 ; Level of debugging information we are producing. See flag-types.h
118 ; for the definitions of the different possible levels.
119 Variable
120 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
121
122 ; Nonzero means use GNU-only extensions in the generated symbolic
123 ; debugging information. Currently, this only has an effect when
124 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
125 Variable
126 bool use_gnu_debug_info_extensions
127
128 ; Original value of maximum field alignment in bytes, specified via
129 ; -fpack-struct=<value>.
130 Variable
131 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
132
133 ; Type of stack check.
134 Variable
135 enum stack_check_type flag_stack_check = NO_STACK_CHECK
136
137 ; True if stack usage information needs to be computed.
138 Variable
139 bool flag_stack_usage_info = false
140
141 ; -dA causes debug commentary information to be produced in
142 ; the generated assembly code (to make it more readable). This option
143 ; is generally only of use to those who actually need to read the
144 ; generated assembly code (perhaps while debugging the compiler itself).
145 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
146 ; to be a catchall for printing debug information in the assembler file.
147 Variable
148 int flag_debug_asm
149
150 ; How many NOP insns to place at each function entry by default
151 Variable
152 HOST_WIDE_INT function_entry_patch_area_size
153
154 ; And how far the real asm entry point is into this area
155 Variable
156 HOST_WIDE_INT function_entry_patch_area_start
157
158 ; Balance between GNAT encodings and standard DWARF to emit.
159 Variable
160 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
161
162 ; -dP causes the rtl to be emitted as a comment in assembly.
163 Variable
164 int flag_dump_rtl_in_asm
165
166 ; Whether -da was passed (used only in handle_common_deferred_options).
167 Variable
168 bool flag_dump_all_passed
169
170 ; Other flags saying which kinds of debugging dump have been requested.
171
172 Variable
173 int rtl_dump_and_exit
174
175 Variable
176 int flag_print_asm_name
177
178 ; Name of top-level original source file (what was input to cpp).
179 ; This comes from the #-command at the beginning of the actual input.
180 ; If there isn't any there, then this is the cc1 input file name.
181 Variable
182 const char *main_input_filename
183
184 ; Pointer to base name in main_input_filename, with directories and a
185 ; single final extension removed, and the length of this base
186 ; name.
187
188 Variable
189 const char *main_input_basename
190
191 Variable
192 int main_input_baselength
193
194 ; Which options have been printed by --help.
195 Variable
196 char *help_printed
197
198 ; Which enums have been printed by --help. 0 = not printed, no
199 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
200 ; = printed.
201 Variable
202 char *help_enum_printed
203
204 ; The number of columns for --help output.
205 Variable
206 unsigned int help_columns
207
208 ; Whether this options structure has been through finish_options
209 Variable
210 bool flag_opts_finished
211
212 ; What the sanitizer should instrument
213 Variable
214 unsigned int flag_sanitize
215
216 ; What sanitizers should recover from errors
217 Variable
218 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
219
220 ; What the coverage sanitizers should instrument
221 Variable
222 unsigned int flag_sanitize_coverage
223
224 ; Flag whether a prefix has been added to dump_base_name
225 Variable
226 bool dump_base_name_prefixed = false
227
228 ; Flag whether HSA generation has been explicitely disabled
229 Variable
230 bool flag_disable_hsa = false
231
232 ###
233 Driver
234
235 -assemble
236 Driver Alias(S)
237
238 -compile
239 Driver Alias(c)
240
241 -completion=
242 Common Driver Joined Undocumented
243 Provide bash completion for options starting with provided string.
244
245 -coverage
246 Driver Alias(coverage)
247
248 -debug
249 Common Alias(g)
250
251 -dump
252 Common Separate Alias(d)
253
254 -dump=
255 Common Joined Alias(d)
256
257 -dumpbase
258 Common Separate Alias(dumpbase)
259
260 -dumpdir
261 Common Separate Alias(dumpdir)
262
263 -entry
264 Driver Separate Alias(e)
265
266 -entry=
267 Driver Joined Alias(e)
268
269 -extra-warnings
270 Common Warning Alias(Wextra)
271
272 -for-assembler
273 Driver Separate Alias(Xassembler)
274
275 -for-assembler=
276 Driver JoinedOrMissing Alias(Xassembler)
277
278 -for-linker
279 Driver Separate Alias(Xlinker)
280
281 -for-linker=
282 Driver JoinedOrMissing Alias(Xlinker)
283
284 -force-link
285 Driver Separate Alias(u)
286
287 -force-link=
288 Driver Joined Alias(u)
289
290 -help
291 Common Driver Var(help_flag)
292 Display this information.
293
294 -help=
295 Common Driver Report Joined
296 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
297
298 -language
299 Driver Separate Alias(x)
300
301 -language=
302 Driver Joined Alias(x)
303
304 -library-directory
305 Driver Separate Alias(L)
306
307 -library-directory=
308 Driver Joined Alias(L)
309
310 -no-canonical-prefixes
311 Driver Alias(no-canonical-prefixes)
312
313 -no-standard-libraries
314 Driver Alias(nostdlib)
315
316 -no-sysroot-suffix
317 Driver Var(no_sysroot_suffix)
318
319 -no-warnings
320 Common Alias(w)
321
322 -optimize
323 Common Alias(O)
324
325 -output
326 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
327
328 -output=
329 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
330
331 -pass-exit-codes
332 Driver Alias(pass-exit-codes)
333
334 -pedantic
335 Common Alias(Wpedantic)
336
337 -pedantic-errors
338 Common Alias(pedantic-errors)
339
340 -pie
341 Driver Alias(pie)
342
343 -static-pie
344 Driver Alias(static-pie)
345
346 -pipe
347 Driver Alias(pipe)
348
349 -prefix
350 Driver Separate Alias(B)
351
352 -prefix=
353 Driver JoinedOrMissing Alias(B)
354
355 -preprocess
356 Driver Alias(E)
357
358 -print-file-name
359 Driver Separate Alias(print-file-name=)
360
361 -print-file-name=
362 Driver JoinedOrMissing Alias(print-file-name=)
363
364 -print-libgcc-file-name
365 Driver Alias(print-libgcc-file-name)
366
367 -print-multi-directory
368 Driver Alias(print-multi-directory)
369
370 -print-multi-lib
371 Driver Alias(print-multi-lib)
372
373 -print-multi-os-directory
374 Driver Alias(print-multi-os-directory)
375
376 -print-multiarch
377 Driver Alias(print-multiarch)
378
379 -print-prog-name
380 Driver Separate Alias(print-prog-name=)
381
382 -print-prog-name=
383 Driver JoinedOrMissing Alias(print-prog-name=)
384
385 -print-search-dirs
386 Driver Alias(print-search-dirs)
387
388 -print-sysroot
389 Driver Alias(print-sysroot)
390
391 -print-sysroot-headers-suffix
392 Driver Alias(print-sysroot-headers-suffix)
393
394 -profile
395 Common Alias(p)
396
397 -save-temps
398 Driver Alias(save-temps)
399
400 -shared
401 Driver Alias(shared)
402
403 -specs
404 Driver Separate Alias(specs=)
405
406 -specs=
407 Driver Joined Alias(specs=)
408
409 -static
410 Driver Alias(static)
411
412 -symbolic
413 Driver Alias(symbolic)
414
415 -target-help
416 Common Driver
417 Alias for --help=target.
418
419 -time
420 Driver Alias(time)
421
422 -verbose
423 Driver Alias(v)
424
425 ;; The driver used to convert options such as --help into forms such
426 ;; as -fhelp; the following four entries are for compatibility with
427 ;; any direct uses of those (undocumented) -f forms
428 fhelp
429 Common Driver Alias(-help)
430
431 fhelp=
432 Common Driver Joined Alias(-help=)
433
434 ftarget-help
435 Common Driver Alias(-target-help)
436
437 fversion
438 Common Driver Alias(-version)
439
440 -param
441 Common Separate
442 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
443
444 -param=
445 Common Joined Alias(-param)
446
447 -sysroot
448 Driver Separate Alias(-sysroot=)
449
450 -sysroot=
451 Driver JoinedOrMissing
452
453 -version
454 Common Driver
455
456 B
457 Driver Joined Separate
458
459 E
460 Driver
461
462 L
463 Driver Joined Separate
464
465 N
466 Driver
467
468 O
469 Common JoinedOrMissing Optimization
470 -O<number> Set optimization level to <number>.
471
472 Os
473 Common Optimization
474 Optimize for space rather than speed.
475
476 Ofast
477 Common Optimization
478 Optimize for speed disregarding exact standards compliance.
479
480 Og
481 Common Optimization
482 Optimize for debugging experience rather than speed or size.
483
484 Q
485 Driver
486
487 Qn
488 Driver Negative(Qy)
489
490 Qy
491 Driver Negative(Qn)
492
493 R
494 Driver Joined Separate
495
496 S
497 Driver
498
499 T
500 Driver Joined Separate
501
502 Tbss
503 Driver Separate
504
505 Tbss=
506 Driver Joined
507
508 Tdata
509 Driver Separate
510
511 Tdata=
512 Driver Joined
513
514 Ttext
515 Driver Separate
516
517 Ttext=
518 Driver Joined
519
520 W
521 Common RejectNegative Warning Alias(Wextra)
522 This switch is deprecated; use -Wextra instead.
523
524 Wa,
525 Driver JoinedOrMissing RejectNegative
526
527 Wl,
528 Driver JoinedOrMissing RejectNegative
529
530 Wp,
531 Driver JoinedOrMissing RejectNegative
532
533 Waggregate-return
534 Common Var(warn_aggregate_return) Warning
535 Warn about returning structures, unions or arrays.
536
537 Waggressive-loop-optimizations
538 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
539 Warn if a loop with constant number of iterations triggers undefined behavior.
540
541 Warray-bounds
542 Common Var(warn_array_bounds) Warning
543 Warn if an array is accessed out of bounds.
544
545 Warray-bounds=
546 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
547 Warn if an array is accessed out of bounds.
548
549 Wattributes
550 Common Var(warn_attributes) Init(1) Warning
551 Warn about inappropriate attribute usage.
552
553 Wattribute-alias
554 Common Alias(Wattribute_alias=, 1, 0) Warning
555 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
556
557 Wattribute-alias=
558 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
559 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
560
561 Wcannot-profile
562 Common Var(warn_cannot_profile) Init(1) Warning
563 Warn when profiling instrumentation was requested, but could not be applied to
564 a certain function.
565
566 Wcast-align
567 Common Var(warn_cast_align) Warning
568 Warn about pointer casts which increase alignment.
569
570 Wcast-align=strict
571 Common Var(warn_cast_align,2) Warning
572 Warn about pointer casts which increase alignment.
573
574 Wcpp
575 Common Var(warn_cpp) Init(1) Warning
576 Warn when a #warning directive is encountered.
577
578 Wattribute-warning
579 Common Var(warn_attribute_warning) Init(1) Warning
580 Warn about uses of __attribute__((warning)) declarations.
581
582 Wdeprecated
583 Common Var(warn_deprecated) Init(1) Warning
584 Warn if a deprecated compiler feature, class, method, or field is used.
585
586 Wdeprecated-declarations
587 Common Var(warn_deprecated_decl) Init(1) Warning
588 Warn about uses of __attribute__((deprecated)) declarations.
589
590 Wdisabled-optimization
591 Common Var(warn_disabled_optimization) Warning
592 Warn when an optimization pass is disabled.
593
594 Werror
595 Common Var(warnings_are_errors)
596 Treat all warnings as errors.
597
598 Werror=
599 Common Joined
600 Treat specified warning as error.
601
602 Wextra
603 Common Var(extra_warnings) Warning
604 Print extra (possibly unwanted) warnings.
605
606 Wfatal-errors
607 Common Var(flag_fatal_errors)
608 Exit on the first error occurred.
609
610 Wframe-larger-than=
611 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
612 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
613
614 Wfree-nonheap-object
615 Common Var(warn_free_nonheap_object) Init(1) Warning
616 Warn when attempting to free a non-heap object.
617
618 Whsa
619 Common Var(warn_hsa) Init(1) Warning
620 Warn when a function cannot be expanded to HSAIL.
621
622 Wimplicit-fallthrough
623 Common Alias(Wimplicit-fallthrough=,3,0) Warning
624
625 Wimplicit-fallthrough=
626 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
627 Warn when a switch case falls through.
628
629 Winline
630 Common Var(warn_inline) Warning
631 Warn when an inlined function cannot be inlined.
632
633 Winvalid-memory-model
634 Common Var(warn_invalid_memory_model) Init(1) Warning
635 Warn when an atomic memory model parameter is known to be outside the valid range.
636
637 Wlarger-than-
638 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
639
640 Wlarger-than=
641 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
642 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
643
644 Wnonnull-compare
645 Var(warn_nonnull_compare) Warning
646 Warn if comparing pointer parameter with nonnull attribute with NULL.
647
648 Wnull-dereference
649 Common Var(warn_null_dereference) Warning
650 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
651
652 Wunsafe-loop-optimizations
653 Common Ignore Warning
654 Does nothing. Preserved for backward compatibility.
655
656 Wmissing-noreturn
657 Common Warning Alias(Wsuggest-attribute=noreturn)
658
659 Wodr
660 Common Var(warn_odr_violations) Init(1) Warning
661 Warn about some C++ One Definition Rule violations during link time optimization.
662
663 Woverflow
664 Common Var(warn_overflow) Init(1) Warning
665 Warn about overflow in arithmetic expressions.
666
667 Wlto-type-mismatch
668 Common Var(warn_lto_type_mismatch) Init(1) Warning
669 During link time optimization warn about mismatched types of global declarations.
670
671 Wpacked
672 Common Var(warn_packed) Warning
673 Warn when the packed attribute has no effect on struct layout.
674
675 Wpadded
676 Common Var(warn_padded) Warning
677 Warn when padding is required to align structure members.
678
679 Wpedantic
680 Common Var(pedantic) Init(0) Warning
681 Issue warnings needed for strict compliance to the standard.
682
683 Wreturn-local-addr
684 Common Var(warn_return_local_addr) Init(1) Warning
685 Warn about returning a pointer/reference to a local or temporary variable.
686
687 Wshadow
688 Common Var(warn_shadow) Warning
689 Warn when one variable shadows another. Same as -Wshadow=global.
690
691 Wshadow=global
692 Common Warning Alias(Wshadow)
693 Warn when one variable shadows another (globally).
694
695 Wshadow=local
696 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
697 Warn when one local variable shadows another local variable or parameter.
698
699 Wshadow-local
700 Common Warning Undocumented Alias(Wshadow=local)
701
702 Wshadow=compatible-local
703 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
704 Warn when one local variable shadows another local variable or parameter of compatible type.
705
706 Wshadow-compatible-local
707 Common Warning Undocumented Alias(Wshadow=compatible-local)
708
709 Wstack-protector
710 Common Var(warn_stack_protect) Warning
711 Warn when not issuing stack smashing protection for some reason.
712
713 Wstack-usage=
714 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
715 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
716
717 Wstrict-aliasing
718 Common Warning
719 Warn about code which might break strict aliasing rules.
720
721 Wstrict-aliasing=
722 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
723 Warn about code which might break strict aliasing rules.
724
725 Wstrict-overflow
726 Common Warning
727 Warn about optimizations that assume that signed overflow is undefined.
728
729 Wstrict-overflow=
730 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
731 Warn about optimizations that assume that signed overflow is undefined.
732
733 Wsuggest-attribute=cold
734 Common Var(warn_suggest_attribute_cold) Warning
735 Warn about functions which might be candidates for __attribute__((cold)).
736
737 Wsuggest-attribute=const
738 Common Var(warn_suggest_attribute_const) Warning
739 Warn about functions which might be candidates for __attribute__((const)).
740
741 Wsuggest-attribute=pure
742 Common Var(warn_suggest_attribute_pure) Warning
743 Warn about functions which might be candidates for __attribute__((pure)).
744
745 Wsuggest-attribute=noreturn
746 Common Var(warn_suggest_attribute_noreturn) Warning
747 Warn about functions which might be candidates for __attribute__((noreturn)).
748
749 Wsuggest-attribute=malloc
750 Common Var(warn_suggest_attribute_malloc) Warning
751 Warn about functions which might be candidates for __attribute__((malloc)).
752
753 Wsuggest-final-types
754 Common Var(warn_suggest_final_types) Warning
755 Warn about C++ polymorphic types where adding final keyword would improve code quality.
756
757 Wsuggest-final-methods
758 Common Var(warn_suggest_final_methods) Warning
759 Warn about C++ virtual methods where adding final keyword would improve code quality.
760
761 Wswitch-unreachable
762 Common Var(warn_switch_unreachable) Warning Init(1)
763 Warn about statements between switch's controlling expression and the first
764 case.
765
766 Wsystem-headers
767 Common Var(warn_system_headers) Warning
768 Do not suppress warnings from system headers.
769
770 Wtrampolines
771 Common Var(warn_trampolines) Warning
772 Warn whenever a trampoline is generated.
773
774 Wtype-limits
775 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
776 Warn if a comparison is always true or always false due to the limited range of the data type.
777
778 Wuninitialized
779 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
780 Warn about uninitialized automatic variables.
781
782 Wmaybe-uninitialized
783 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
784 Warn about maybe uninitialized automatic variables.
785
786 Wunreachable-code
787 Common Ignore Warning
788 Does nothing. Preserved for backward compatibility.
789
790 Wunused
791 Common Var(warn_unused) Init(0) Warning
792 Enable all -Wunused- warnings.
793
794 Wunused-but-set-parameter
795 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
796 Warn when a function parameter is only set, otherwise unused.
797
798 Wunused-but-set-variable
799 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
800 Warn when a variable is only set, otherwise unused.
801
802 Wunused-function
803 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
804 Warn when a function is unused.
805
806 Wunused-label
807 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
808 Warn when a label is unused.
809
810 Wunused-parameter
811 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
812 Warn when a function parameter is unused.
813
814 Wunused-value
815 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
816 Warn when an expression value is unused.
817
818 Wunused-variable
819 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
820 Warn when a variable is unused.
821
822 Wcoverage-mismatch
823 Common Var(warn_coverage_mismatch) Init(1) Warning
824 Warn in case profiles in -fprofile-use do not match.
825
826 Wmissing-profile
827 Common Var(warn_missing_profile) Init(1) Warning
828 Warn in case profiles in -fprofile-use do not exist.
829
830 Wvector-operation-performance
831 Common Var(warn_vector_operation_performance) Warning
832 Warn when a vector operation is compiled outside the SIMD.
833
834 Xassembler
835 Driver Separate
836
837 Xlinker
838 Driver Separate
839
840 Xpreprocessor
841 Driver Separate
842
843 Z
844 Driver
845
846 aux-info
847 Common Separate Var(aux_info_file_name)
848 -aux-info <file> Emit declaration information into <file>.
849
850 aux-info=
851 Common Joined Alias(aux-info)
852
853 auxbase
854 Common Separate RejectDriver Var(aux_base_name)
855
856 auxbase-strip
857 Common Separate RejectDriver
858
859 coverage
860 Driver
861
862 c
863 Driver
864
865 d
866 Common Joined
867 -d<letters> Enable dumps from specific passes of the compiler.
868
869 dumpbase
870 Common Separate Var(dump_base_name)
871 -dumpbase <file> Set the file basename to be used for dumps.
872
873 dumpdir
874 Common Separate Var(dump_dir_name)
875 -dumpdir <dir> Set the directory name to be used for dumps.
876
877 dumpmachine
878 Driver
879
880 dumpspecs
881 Driver
882
883 dumpversion
884 Driver
885
886 dumpfullversion
887 Driver
888
889 e
890 Driver Joined Separate
891
892 ; This option has historically been passed down to the linker by an
893 ; accident of a %{e*} spec, so ensure it continues to be passed down
894 ; as a single option. The supported option for this purpose is
895 ; -rdynamic. See PR 47390.
896 export-dynamic
897 Driver Undocumented
898
899 ; The version of the C++ ABI in use. The following values are allowed:
900 ;
901 ; 0: The version of the ABI believed most conformant with the C++ ABI
902 ; specification. This ABI may change as bugs are discovered and fixed.
903 ; Therefore, 0 will not necessarily indicate the same ABI in different
904 ; versions of G++.
905 ;
906 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
907 ;
908 ; 2: The version of the ABI first used in G++ 3.4, and the default
909 ; until GCC 4.9.
910 ;
911 ; 3: The version of the ABI that fixes the missing underscore
912 ; in template non-type arguments of pointer type.
913 ;
914 ; 4: The version of the ABI that introduces unambiguous mangling of
915 ; vector types. First selectable in G++ 4.5.
916 ;
917 ; 5: The version of the ABI that ignores attribute const/noreturn
918 ; in function pointer mangling, and corrects mangling of decltype and
919 ; function parameters used in other parameters and the return type.
920 ; First selectable in G++ 4.6.
921 ;
922 ; 6: The version of the ABI that doesn't promote scoped enums to int and
923 ; changes the mangling of template argument packs, const/static_cast,
924 ; prefix ++ and --, and a class scope function used as a template
925 ; argument.
926 ; First selectable in G++ 4.7.
927 ;
928 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
929 ; corrects the mangling of lambdas in default argument scope.
930 ; First selectable in G++ 4.8.
931 ;
932 ; 8: The version of the ABI that corrects the substitution behavior of
933 ; function types with function-cv-qualifiers.
934 ; First selectable in G++ 4.9 and default in G++ 5.
935 ;
936 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
937 ; First selectable and default in G++ 5.2.
938 ;
939 ; 10: The version of the ABI that mangles attributes that affect type
940 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
941 ; Default in G++ 6 (set in c_common_post_options).
942 ;
943 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
944 ; and introduces new inheriting constructor handling.
945 ; Default in G++ 7.
946 ;
947 ; 12: Corrects the calling convention for classes with only deleted copy/move
948 ; constructors and changes passing/returning of empty records.
949 ; Default in G++ 8.1.
950 ;
951 ; 13: Fixes the accidental change in 12 to the calling convention for classes
952 ; with deleted copy constructor and trivial move constructor.
953 ; Default in G++ 8.2.
954 ;
955 ; Additional positive integers will be assigned as new versions of
956 ; the ABI become the default version of the ABI.
957 fabi-version=
958 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
959 The version of the C++ ABI in use.
960
961 faggressive-loop-optimizations
962 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
963 Aggressively optimize loops using language constraints.
964
965 falign-functions
966 Common Report Var(flag_align_functions) Optimization
967 Align the start of functions.
968
969 falign-functions=
970 Common RejectNegative Joined Var(str_align_functions) Optimization
971
972 flimit-function-alignment
973 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
974
975 falign-jumps
976 Common Report Var(flag_align_jumps) Optimization
977 Align labels which are only reached by jumping.
978
979 falign-jumps=
980 Common RejectNegative Joined Var(str_align_jumps) Optimization
981
982 falign-labels
983 Common Report Var(flag_align_labels) Optimization
984 Align all labels.
985
986 falign-labels=
987 Common RejectNegative Joined Var(str_align_labels) Optimization
988
989 falign-loops
990 Common Report Var(flag_align_loops) Optimization
991 Align the start of loops.
992
993 falign-loops=
994 Common RejectNegative Joined Var(str_align_loops) Optimization
995
996 fargument-alias
997 Common Ignore
998 Does nothing. Preserved for backward compatibility.
999
1000 fargument-noalias
1001 Common Ignore
1002 Does nothing. Preserved for backward compatibility.
1003
1004 fargument-noalias-global
1005 Common Ignore
1006 Does nothing. Preserved for backward compatibility.
1007
1008 fargument-noalias-anything
1009 Common Ignore
1010 Does nothing. Preserved for backward compatibility.
1011
1012 fsanitize=
1013 Common Driver Report Joined
1014 Select what to sanitize.
1015
1016 fsanitize-coverage=
1017 Common Report Joined
1018 Select type of coverage sanitization.
1019
1020 fasan-shadow-offset=
1021 Common Joined RejectNegative Var(common_deferred_options) Defer
1022 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1023
1024 fsanitize-sections=
1025 Common Joined RejectNegative Var(common_deferred_options) Defer
1026 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1027 in user-defined sections.
1028
1029 fsanitize-recover=
1030 Common Report Joined
1031 After diagnosing undefined behavior attempt to continue execution.
1032
1033 fsanitize-recover
1034 Common Report
1035 This switch is deprecated; use -fsanitize-recover= instead.
1036
1037 fsanitize-address-use-after-scope
1038 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1039
1040 fsanitize-undefined-trap-on-error
1041 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1042 Use trap instead of a library function for undefined behavior sanitization.
1043
1044 fasynchronous-unwind-tables
1045 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1046 Generate unwind tables that are exact at each instruction boundary.
1047
1048 fauto-inc-dec
1049 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1050 Generate auto-inc/dec instructions.
1051
1052 fauto-profile
1053 Common Report Var(flag_auto_profile)
1054 Use sample profile information for call graph node weights. The default
1055 profile file is fbdata.afdo in 'pwd'.
1056
1057 fauto-profile=
1058 Common Joined RejectNegative Var(auto_profile_file)
1059 Use sample profile information for call graph node weights. The profile
1060 file is specified in the argument.
1061
1062 ; -fcheck-bounds causes gcc to generate array bounds checks.
1063 ; For C, C++ and ObjC: defaults off.
1064 ; For Java: defaults to on.
1065 ; For Fortran: defaults to off.
1066 fbounds-check
1067 Common Report Var(flag_bounds_check)
1068 Generate code to check bounds before indexing arrays.
1069
1070 fbranch-count-reg
1071 Common Report Var(flag_branch_on_count_reg) Optimization
1072 Replace add, compare, branch with branch on count register.
1073
1074 fbranch-probabilities
1075 Common Report Var(flag_branch_probabilities) Optimization
1076 Use profiling information for branch probabilities.
1077
1078 fbranch-target-load-optimize
1079 Common Report Var(flag_branch_target_load_optimize) Optimization
1080 Perform branch target load optimization before prologue / epilogue threading.
1081
1082 fbranch-target-load-optimize2
1083 Common Report Var(flag_branch_target_load_optimize2) Optimization
1084 Perform branch target load optimization after prologue / epilogue threading.
1085
1086 fbtr-bb-exclusive
1087 Common Report Var(flag_btr_bb_exclusive) Optimization
1088 Restrict target load migration not to re-use registers in any basic block.
1089
1090 fcall-saved-
1091 Common Joined RejectNegative Var(common_deferred_options) Defer
1092 -fcall-saved-<register> Mark <register> as being preserved across functions.
1093
1094 fcall-used-
1095 Common Joined RejectNegative Var(common_deferred_options) Defer
1096 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1097
1098 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1099 ; be saved across function calls, if that produces overall better code.
1100 ; Optional now, so people can test it.
1101 fcaller-saves
1102 Common Report Var(flag_caller_saves) Optimization
1103 Save registers around function calls.
1104
1105 fcheck-data-deps
1106 Common Ignore
1107 This switch is deprecated; do not use.
1108
1109 fcheck-new
1110 Common Var(flag_check_new)
1111 Check the return value of new in C++.
1112
1113 fchecking
1114 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1115 Perform internal consistency checkings.
1116
1117 fchecking=
1118 Common Joined RejectNegative UInteger Var(flag_checking)
1119 Perform internal consistency checkings.
1120
1121 fcode-hoisting
1122 Common Report Var(flag_code_hoisting) Optimization
1123 Enable code hoisting.
1124
1125 fcombine-stack-adjustments
1126 Common Report Var(flag_combine_stack_adjustments) Optimization
1127 Looks for opportunities to reduce stack adjustments and stack references.
1128
1129 fcommon
1130 Common Report Var(flag_no_common,0)
1131 Do not put uninitialized globals in the common section.
1132
1133 fcompare-debug
1134 Driver
1135 ; Converted by the driver to -fcompare-debug= options.
1136
1137 fcompare-debug=
1138 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1139 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1140
1141 fcompare-debug-second
1142 Common Driver RejectNegative Var(flag_compare_debug)
1143 Run only the second compilation of -fcompare-debug.
1144
1145 fcompare-elim
1146 Common Report Var(flag_compare_elim_after_reload) Optimization
1147 Perform comparison elimination after register allocation has finished.
1148
1149 fconserve-stack
1150 Common Var(flag_conserve_stack) Optimization
1151 Do not perform optimizations increasing noticeably stack usage.
1152
1153 fcprop-registers
1154 Common Report Var(flag_cprop_registers) Optimization
1155 Perform a register copy-propagation optimization pass.
1156
1157 fcrossjumping
1158 Common Report Var(flag_crossjumping) Optimization
1159 Perform cross-jumping optimization.
1160
1161 fcse-follow-jumps
1162 Common Report Var(flag_cse_follow_jumps) Optimization
1163 When running CSE, follow jumps to their targets.
1164
1165 fcse-skip-blocks
1166 Common Ignore
1167 Does nothing. Preserved for backward compatibility.
1168
1169 fcx-limited-range
1170 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1171 Omit range reduction step when performing complex division.
1172
1173 fcx-fortran-rules
1174 Common Report Var(flag_cx_fortran_rules) Optimization
1175 Complex multiplication and division follow Fortran rules.
1176
1177 fdata-sections
1178 Common Report Var(flag_data_sections)
1179 Place data items into their own section.
1180
1181 fdbg-cnt-list
1182 Common Report Var(common_deferred_options) Defer
1183 List all available debugging counters with their limits and counts.
1184
1185 fdbg-cnt=
1186 Common RejectNegative Joined Var(common_deferred_options) Defer
1187 -fdbg-cnt=<counter>[:<lower_limit>]:<upper_limit>[,<counter>:...] Set the debug counter limit.
1188
1189 fdebug-prefix-map=
1190 Common Joined RejectNegative Var(common_deferred_options) Defer
1191 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1192
1193 ffile-prefix-map=
1194 Common Joined RejectNegative Var(common_deferred_options) Defer
1195 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1196
1197 fdebug-types-section
1198 Common Report Var(flag_debug_types_section) Init(0)
1199 Output .debug_types section when using DWARF v4 debuginfo.
1200
1201 ; Nonzero for -fdefer-pop: don't pop args after each function call
1202 ; instead save them up to pop many calls' args with one insns.
1203 fdefer-pop
1204 Common Report Var(flag_defer_pop) Optimization
1205 Defer popping functions args from stack until later.
1206
1207 fdelayed-branch
1208 Common Report Var(flag_delayed_branch) Optimization
1209 Attempt to fill delay slots of branch instructions.
1210
1211 fdelete-dead-exceptions
1212 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1213 Delete dead instructions that may throw exceptions.
1214
1215 fdelete-null-pointer-checks
1216 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1217 Delete useless null pointer checks.
1218
1219 fdevirtualize-at-ltrans
1220 Common Report Var(flag_ltrans_devirtualize)
1221 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1222
1223 fdevirtualize-speculatively
1224 Common Report Var(flag_devirtualize_speculatively) Optimization
1225 Perform speculative devirtualization.
1226
1227 fdevirtualize
1228 Common Report Var(flag_devirtualize) Optimization
1229 Try to convert virtual calls to direct ones.
1230
1231 fdiagnostics-show-location=
1232 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1233 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1234
1235 ; Required for these enum values.
1236 SourceInclude
1237 pretty-print.h
1238
1239 Enum
1240 Name(diagnostic_prefixing_rule) Type(int)
1241
1242 EnumValue
1243 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1244
1245 EnumValue
1246 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1247
1248 fdiagnostics-show-caret
1249 Common Var(flag_diagnostics_show_caret) Init(1)
1250 Show the source line with a caret indicating the column.
1251
1252 fdiagnostics-show-labels
1253 Common Var(flag_diagnostics_show_labels) Init(1)
1254 Show labels annotating ranges of source code when showing source.
1255
1256 fdiagnostics-show-line-numbers
1257 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1258 Show line numbers in the left margin when showing source.
1259
1260 fdiagnostics-color
1261 Common Alias(fdiagnostics-color=,always,never)
1262 ;
1263
1264 fdiagnostics-color=
1265 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1266 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1267
1268 ; Required for these enum values.
1269 SourceInclude
1270 diagnostic-color.h
1271
1272 Enum
1273 Name(diagnostic_color_rule) Type(int)
1274
1275 EnumValue
1276 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1277
1278 EnumValue
1279 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1280
1281 EnumValue
1282 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1283
1284 fdiagnostics-format=
1285 Common Joined RejectNegative Enum(diagnostics_output_format)
1286 -fdiagnostics-format=[text|json] Select output format.
1287
1288 ; Required for these enum values.
1289 SourceInclude
1290 diagnostic.h
1291
1292 Enum
1293 Name(diagnostics_output_format) Type(int)
1294
1295 EnumValue
1296 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1297
1298 EnumValue
1299 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1300
1301 fdiagnostics-parseable-fixits
1302 Common Var(flag_diagnostics_parseable_fixits)
1303 Print fix-it hints in machine-readable form.
1304
1305 fdiagnostics-generate-patch
1306 Common Var(flag_diagnostics_generate_patch)
1307 Print fix-it hints to stderr in unified diff format.
1308
1309 fdiagnostics-show-option
1310 Common Var(flag_diagnostics_show_option) Init(1)
1311 Amend appropriate diagnostic messages with the command line option that controls them.
1312
1313 fdiagnostics-minimum-margin-width=
1314 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1315 Set minimum width of left margin of source code when showing source.
1316
1317 fdisable-
1318 Common Joined RejectNegative Var(common_deferred_options) Defer
1319 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1320
1321 fenable-
1322 Common Joined RejectNegative Var(common_deferred_options) Defer
1323 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1324
1325 fdump-
1326 Common Joined RejectNegative Var(common_deferred_options) Defer
1327 -fdump-<type> Dump various compiler internals to a file.
1328
1329 fdump-final-insns
1330 Driver RejectNegative
1331
1332 fdump-final-insns=
1333 Common RejectNegative Joined Var(flag_dump_final_insns)
1334 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1335
1336 fdump-go-spec=
1337 Common RejectNegative Joined Var(flag_dump_go_spec)
1338 -fdump-go-spec=filename Write all declarations to file as Go code.
1339
1340 fdump-noaddr
1341 Common Report Var(flag_dump_noaddr)
1342 Suppress output of addresses in debugging dumps.
1343
1344 freport-bug
1345 Common Driver Var(flag_report_bug)
1346 Collect and dump debug information into temporary file if ICE in C/C++
1347 compiler occurred.
1348
1349 fdump-internal-locations
1350 Common Var(flag_dump_locations) Init(0)
1351 Dump detailed information on GCC's internal representation of source code locations.
1352
1353 fdump-passes
1354 Common Var(flag_dump_passes) Init(0)
1355 Dump optimization passes.
1356
1357 fdump-unnumbered
1358 Common Report Var(flag_dump_unnumbered)
1359 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1360
1361 fdump-unnumbered-links
1362 Common Report Var(flag_dump_unnumbered_links)
1363 Suppress output of previous and next insn numbers in debugging dumps.
1364
1365 fdwarf2-cfi-asm
1366 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1367 Enable CFI tables via GAS assembler directives.
1368
1369 fearly-inlining
1370 Common Report Var(flag_early_inlining) Init(1) Optimization
1371 Perform early inlining.
1372
1373 feliminate-dwarf2-dups
1374 Common Ignore
1375 Does nothing. Preserved for backward compatibility.
1376
1377 fipa-sra
1378 Common Report Var(flag_ipa_sra) Init(0) Optimization
1379 Perform interprocedural reduction of aggregates.
1380
1381 feliminate-unused-debug-symbols
1382 Common Report Var(flag_debug_only_used_symbols) Init(1)
1383 Perform unused symbol elimination in debug info.
1384
1385 feliminate-unused-debug-types
1386 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1387 Perform unused type elimination in debug info.
1388
1389 femit-class-debug-always
1390 Common Report Var(flag_emit_class_debug_always) Init(0)
1391 Do not suppress C++ class debug information.
1392
1393 fexceptions
1394 Common Report Var(flag_exceptions) Optimization
1395 Enable exception handling.
1396
1397 fexpensive-optimizations
1398 Common Report Var(flag_expensive_optimizations) Optimization
1399 Perform a number of minor, expensive optimizations.
1400
1401 fexcess-precision=
1402 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1403 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1404
1405 Enum
1406 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1407
1408 EnumValue
1409 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1410
1411 EnumValue
1412 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1413
1414 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1415 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1416 fpermitted-flt-eval-methods=
1417 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1418 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1419
1420 Enum
1421 Name(permitted_flt_eval_methods) Type(enum permitted_flt_eval_methods) UnknownError(unknown specification for the set of FLT_EVAL_METHOD values to permit %qs)
1422
1423 EnumValue
1424 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1425
1426 EnumValue
1427 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1428
1429 ffast-math
1430 Common Optimization
1431
1432 ffat-lto-objects
1433 Common Var(flag_fat_lto_objects)
1434 Output lto objects containing both the intermediate language and binary output.
1435
1436 ffinite-math-only
1437 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1438 Assume no NaNs or infinities are generated.
1439
1440 ffinite-loops
1441 Common Report Var(flag_finite_loops) Optimization
1442 Assume that loops with an exit will terminate and not loop indefinitely.
1443
1444 ffixed-
1445 Common Joined RejectNegative Var(common_deferred_options) Defer
1446 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1447
1448 ffloat-store
1449 Common Report Var(flag_float_store) Optimization
1450 Don't allocate floats and doubles in extended-precision registers.
1451
1452 fforce-addr
1453 Common Ignore
1454 Does nothing. Preserved for backward compatibility.
1455
1456 fforward-propagate
1457 Common Report Var(flag_forward_propagate) Optimization
1458 Perform a forward propagation pass on RTL.
1459
1460 ffp-contract=
1461 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1462 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1463
1464 Enum
1465 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1466
1467 EnumValue
1468 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1469
1470 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1471 EnumValue
1472 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1473
1474 EnumValue
1475 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1476
1477 ffp-int-builtin-inexact
1478 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1479 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1480
1481 ; Nonzero means don't put addresses of constant functions in registers.
1482 ; Used for compiling the Unix kernel, where strange substitutions are
1483 ; done on the assembly output.
1484 ffunction-cse
1485 Common Report Var(flag_no_function_cse,0) Optimization
1486 Allow function addresses to be held in registers.
1487
1488 ffunction-sections
1489 Common Report Var(flag_function_sections)
1490 Place each function into its own section.
1491
1492 fgcse
1493 Common Report Var(flag_gcse) Optimization
1494 Perform global common subexpression elimination.
1495
1496 fgcse-lm
1497 Common Report Var(flag_gcse_lm) Init(1) Optimization
1498 Perform enhanced load motion during global common subexpression elimination.
1499
1500 fgcse-sm
1501 Common Report Var(flag_gcse_sm) Init(0) Optimization
1502 Perform store motion after global common subexpression elimination.
1503
1504 fgcse-las
1505 Common Report Var(flag_gcse_las) Init(0) Optimization
1506 Perform redundant load after store elimination in global common subexpression
1507 elimination.
1508
1509 fgcse-after-reload
1510 Common Report Var(flag_gcse_after_reload) Optimization
1511 Perform global common subexpression elimination after register allocation has
1512 finished.
1513
1514 Enum
1515 Name(dwarf_gnat_encodings) Type(int)
1516
1517 EnumValue
1518 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1519
1520 EnumValue
1521 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1522
1523 EnumValue
1524 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1525
1526 fgnat-encodings=
1527 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1528 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1529
1530 ; This option is not documented yet as its semantics will change.
1531 fgraphite
1532 Common Report Var(flag_graphite) Optimization
1533 Enable in and out of Graphite representation.
1534
1535 fgraphite-identity
1536 Common Report Var(flag_graphite_identity) Optimization
1537 Enable Graphite Identity transformation.
1538
1539 fhoist-adjacent-loads
1540 Common Report Var(flag_hoist_adjacent_loads) Optimization
1541 Enable hoisting adjacent loads to encourage generating conditional move
1542 instructions.
1543
1544 fkeep-gc-roots-live
1545 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1546 ; Always keep a pointer to a live memory block
1547
1548 floop-parallelize-all
1549 Common Report Var(flag_loop_parallelize_all) Optimization
1550 Mark all loops as parallel.
1551
1552 floop-strip-mine
1553 Common Alias(floop-nest-optimize)
1554 Enable loop nest transforms. Same as -floop-nest-optimize.
1555
1556 floop-interchange
1557 Common Report Var(flag_loop_interchange) Optimization
1558 Enable loop interchange on trees.
1559
1560 floop-block
1561 Common Alias(floop-nest-optimize)
1562 Enable loop nest transforms. Same as -floop-nest-optimize.
1563
1564 floop-unroll-and-jam
1565 Common Report Var(flag_unroll_jam) Optimization
1566 Perform unroll-and-jam on loops.
1567
1568 fgnu-tm
1569 Common Report Var(flag_tm)
1570 Enable support for GNU transactional memory.
1571
1572 fgnu-unique
1573 Common Report Var(flag_gnu_unique) Init(1)
1574 Use STB_GNU_UNIQUE if supported by the assembler.
1575
1576 floop-flatten
1577 Common Ignore
1578 Does nothing. Preserved for backward compatibility.
1579
1580 floop-nest-optimize
1581 Common Report Var(flag_loop_nest_optimize) Optimization
1582 Enable the loop nest optimizer.
1583
1584 fstrict-volatile-bitfields
1585 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1586 Force bitfield accesses to match their type width.
1587
1588 fstore-merging
1589 Common Report Var(flag_store_merging) Optimization
1590 Merge adjacent stores.
1591
1592 fguess-branch-probability
1593 Common Report Var(flag_guess_branch_prob) Optimization
1594 Enable guessing of branch probabilities.
1595
1596 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1597 ; Generate position-independent code for executables if possible
1598 ; On SVR4 targets, it also controls whether or not to emit a
1599 ; string identifying the compiler.
1600 fident
1601 Common Report Var(flag_no_ident,0)
1602 Process #ident directives.
1603
1604 fif-conversion
1605 Common Report Var(flag_if_conversion) Optimization
1606 Perform conversion of conditional jumps to branchless equivalents.
1607
1608 fif-conversion2
1609 Common Report Var(flag_if_conversion2) Optimization
1610 Perform conversion of conditional jumps to conditional execution.
1611
1612 fstack-reuse=
1613 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1614 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1615
1616 Enum
1617 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1618
1619 EnumValue
1620 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1621
1622 EnumValue
1623 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1624
1625 EnumValue
1626 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1627
1628 ftree-loop-if-convert
1629 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1630 Convert conditional jumps in innermost loops to branchless equivalents.
1631
1632 ftree-loop-if-convert-stores
1633 Common Ignore
1634 Does nothing. Preserved for backward compatibility.
1635
1636 ; -finhibit-size-directive inhibits output of .size for ELF.
1637 ; This is used only for compiling crtstuff.c,
1638 ; and it may be extended to other effects
1639 ; needed for crtstuff.c on other systems.
1640 finhibit-size-directive
1641 Common Report Var(flag_inhibit_size_directive)
1642 Do not generate .size directives.
1643
1644 findirect-inlining
1645 Common Report Var(flag_indirect_inlining) Optimization
1646 Perform indirect inlining.
1647
1648 ; General flag to enable inlining. Specifying -fno-inline will disable
1649 ; all inlining apart from always-inline functions.
1650 finline
1651 Common Report Var(flag_no_inline,0) Init(0) Optimization
1652 Enable inlining of function declared \"inline\", disabling disables all inlining.
1653
1654 finline-small-functions
1655 Common Report Var(flag_inline_small_functions) Optimization
1656 Integrate functions into their callers when code size is known not to grow.
1657
1658 finline-functions
1659 Common Report Var(flag_inline_functions) Optimization
1660 Integrate functions not declared \"inline\" into their callers when profitable.
1661
1662 finline-functions-called-once
1663 Common Report Var(flag_inline_functions_called_once) Optimization
1664 Integrate functions only required by their single caller.
1665
1666 finline-limit-
1667 Common RejectNegative Joined Alias(finline-limit=)
1668
1669 finline-limit=
1670 Common RejectNegative Joined UInteger
1671 -finline-limit=<number> Limit the size of inlined functions to <number>.
1672
1673 finline-atomics
1674 Common Report Var(flag_inline_atomics) Init(1) Optimization
1675 Inline __atomic operations when a lock free instruction sequence is available.
1676
1677 fcf-protection
1678 Common RejectNegative Alias(fcf-protection=,full)
1679
1680 fcf-protection=
1681 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1682 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1683 instructions have valid targets.
1684
1685 Enum
1686 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1687
1688 EnumValue
1689 Enum(cf_protection_level) String(full) Value(CF_FULL)
1690
1691 EnumValue
1692 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1693
1694 EnumValue
1695 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1696
1697 EnumValue
1698 Enum(cf_protection_level) String(none) Value(CF_NONE)
1699
1700 finstrument-functions
1701 Common Report Var(flag_instrument_function_entry_exit)
1702 Instrument function entry and exit with profiling calls.
1703
1704 finstrument-functions-exclude-function-list=
1705 Common RejectNegative Joined
1706 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1707
1708 finstrument-functions-exclude-file-list=
1709 Common RejectNegative Joined
1710 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1711
1712 fipa-cp
1713 Common Report Var(flag_ipa_cp) Optimization
1714 Perform interprocedural constant propagation.
1715
1716 fipa-cp-clone
1717 Common Report Var(flag_ipa_cp_clone) Optimization
1718 Perform cloning to make Interprocedural constant propagation stronger.
1719
1720 fipa-cp-alignment
1721 Common Ignore
1722 Does nothing. Preserved for backward compatibility.
1723
1724 fipa-bit-cp
1725 Common Report Var(flag_ipa_bit_cp) Optimization
1726 Perform interprocedural bitwise constant propagation.
1727
1728 fipa-profile
1729 Common Report Var(flag_ipa_profile) Init(0) Optimization
1730 Perform interprocedural profile propagation.
1731
1732 fipa-pta
1733 Common Report Var(flag_ipa_pta) Init(0) Optimization
1734 Perform interprocedural points-to analysis.
1735
1736 fipa-pure-const
1737 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1738 Discover pure and const functions.
1739
1740 fipa-icf
1741 Common Report Var(flag_ipa_icf) Optimization
1742 Perform Identical Code Folding for functions and read-only variables.
1743
1744 fipa-icf-functions
1745 Common Report Var(flag_ipa_icf_functions) Optimization
1746 Perform Identical Code Folding for functions.
1747
1748 fipa-icf-variables
1749 Common Report Var(flag_ipa_icf_variables) Optimization
1750 Perform Identical Code Folding for variables.
1751
1752 fipa-reference
1753 Common Report Var(flag_ipa_reference) Init(0) Optimization
1754 Discover read-only and non addressable static variables.
1755
1756 fipa-reference-addressable
1757 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1758 Discover read-only, write-only and non-addressable static variables.
1759
1760 fipa-stack-alignment
1761 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1762 Reduce stack alignment on call sites if possible.
1763
1764 fipa-matrix-reorg
1765 Common Ignore
1766 Does nothing. Preserved for backward compatibility.
1767
1768 fipa-struct-reorg
1769 Common Ignore
1770 Does nothing. Preserved for backward compatibility.
1771
1772 fipa-vrp
1773 Common Report Var(flag_ipa_vrp) Optimization
1774 Perform IPA Value Range Propagation.
1775
1776 fira-algorithm=
1777 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1778 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1779
1780 Enum
1781 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1782
1783 EnumValue
1784 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1785
1786 EnumValue
1787 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1788
1789 fira-region=
1790 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1791 -fira-region=[one|all|mixed] Set regions for IRA.
1792
1793 Enum
1794 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1795
1796 EnumValue
1797 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1798
1799 EnumValue
1800 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1801
1802 EnumValue
1803 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1804
1805 fira-hoist-pressure
1806 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1807 Use IRA based register pressure calculation
1808 in RTL hoist optimizations.
1809
1810 fira-loop-pressure
1811 Common Report Var(flag_ira_loop_pressure) Optimization
1812 Use IRA based register pressure calculation
1813 in RTL loop optimizations.
1814
1815 fira-share-save-slots
1816 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1817 Share slots for saving different hard registers.
1818
1819 fira-share-spill-slots
1820 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1821 Share stack slots for spilled pseudo-registers.
1822
1823 fira-verbose=
1824 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1825 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1826
1827 fivopts
1828 Common Report Var(flag_ivopts) Init(1) Optimization
1829 Optimize induction variables on trees.
1830
1831 fjump-tables
1832 Common Var(flag_jump_tables) Init(1) Optimization
1833 Use jump tables for sufficiently large switch statements.
1834
1835 fkeep-inline-functions
1836 Common Report Var(flag_keep_inline_functions)
1837 Generate code for functions even if they are fully inlined.
1838
1839 fkeep-static-functions
1840 Common Report Var(flag_keep_static_functions)
1841 Generate code for static functions even if they are never called.
1842
1843 fkeep-static-consts
1844 Common Report Var(flag_keep_static_consts) Init(1)
1845 Emit static const variables even if they are not used.
1846
1847 fleading-underscore
1848 Common Report Var(flag_leading_underscore) Init(-1)
1849 Give external symbols a leading underscore.
1850
1851 floop-optimize
1852 Common Ignore
1853 Does nothing. Preserved for backward compatibility.
1854
1855 flra-remat
1856 Common Report Var(flag_lra_remat) Optimization
1857 Do CFG-sensitive rematerialization in LRA.
1858
1859 flto
1860 Common
1861 Enable link-time optimization.
1862
1863 flto=
1864 Common RejectNegative Joined Var(flag_lto)
1865 Link-time optimization with number of parallel jobs or jobserver.
1866
1867 Enum
1868 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1869
1870 EnumValue
1871 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1872
1873 EnumValue
1874 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1875
1876 EnumValue
1877 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1878
1879 EnumValue
1880 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1881
1882 EnumValue
1883 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1884
1885 flto-partition=
1886 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1887 Specify the algorithm to partition symbols and vars at linktime.
1888
1889 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1890 flto-compression-level=
1891 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
1892 -flto-compression-level=<number> Use zlib/zstd compression level <number> for IL.
1893
1894 flto-odr-type-merging
1895 Common Ignore
1896 Does nothing. Preserved for backward compatibility.
1897
1898 flto-report
1899 Common Report Var(flag_lto_report) Init(0)
1900 Report various link-time optimization statistics.
1901
1902 flto-report-wpa
1903 Common Report Var(flag_lto_report_wpa) Init(0)
1904 Report various link-time optimization statistics for WPA only.
1905
1906 fmath-errno
1907 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1908 Set errno after built-in math functions.
1909
1910 fmax-errors=
1911 Common Joined RejectNegative UInteger Var(flag_max_errors)
1912 -fmax-errors=<number> Maximum number of errors to report.
1913
1914 fmem-report
1915 Common Report Var(mem_report)
1916 Report on permanent memory allocation.
1917
1918 fmem-report-wpa
1919 Common Report Var(mem_report_wpa)
1920 Report on permanent memory allocation in WPA only.
1921
1922 ; This will attempt to merge constant section constants, if 1 only
1923 ; string constants and constants from constant pool, if 2 also constant
1924 ; variables.
1925 fmerge-all-constants
1926 Common Report Var(flag_merge_constants,2) Init(1)
1927 Attempt to merge identical constants and constant variables.
1928
1929 fmerge-constants
1930 Common Report Var(flag_merge_constants,1)
1931 Attempt to merge identical constants across compilation units.
1932
1933 fmerge-debug-strings
1934 Common Report Var(flag_merge_debug_strings) Init(1)
1935 Attempt to merge identical debug strings across compilation units.
1936
1937 fmessage-length=
1938 Common RejectNegative Joined UInteger
1939 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1940
1941 fmodulo-sched
1942 Common Report Var(flag_modulo_sched) Optimization
1943 Perform SMS based modulo scheduling before the first scheduling pass.
1944
1945 fmodulo-sched-allow-regmoves
1946 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1947 Perform SMS based modulo scheduling with register moves allowed.
1948
1949 fmove-loop-invariants
1950 Common Report Var(flag_move_loop_invariants) Optimization
1951 Move loop invariant computations out of loops.
1952
1953 fdce
1954 Common Var(flag_dce) Init(1) Optimization
1955 Use the RTL dead code elimination pass.
1956
1957 fdse
1958 Common Var(flag_dse) Init(1) Optimization
1959 Use the RTL dead store elimination pass.
1960
1961 freschedule-modulo-scheduled-loops
1962 Common Report Var(flag_resched_modulo_sched) Optimization
1963 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1964
1965 fnon-call-exceptions
1966 Common Report Var(flag_non_call_exceptions) Optimization
1967 Support synchronous non-call exceptions.
1968
1969 foffload=
1970 Common Driver Joined MissingArgError(options or targets missing after %qs)
1971 -foffload=<targets>=<options> Specify offloading targets and options for them.
1972
1973 foffload-abi=
1974 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1975 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1976
1977 Enum
1978 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1979
1980 EnumValue
1981 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1982
1983 EnumValue
1984 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1985
1986 fomit-frame-pointer
1987 Common Report Var(flag_omit_frame_pointer) Optimization
1988 When possible do not generate stack frames.
1989
1990 fopt-info
1991 Common Report Var(flag_opt_info) Optimization
1992 Enable all optimization info dumps on stderr.
1993
1994 fopt-info-
1995 Common Joined RejectNegative Var(common_deferred_options) Defer
1996 -fopt-info[-<type>=filename] Dump compiler optimization details.
1997
1998 fsave-optimization-record
1999 Common Report Var(flag_save_optimization_record) Optimization
2000 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2001
2002 foptimize-register-move
2003 Common Ignore
2004 Does nothing. Preserved for backward compatibility.
2005
2006 foptimize-sibling-calls
2007 Common Report Var(flag_optimize_sibling_calls) Optimization
2008 Optimize sibling and tail recursive calls.
2009
2010 fpartial-inlining
2011 Common Report Var(flag_partial_inlining) Optimization
2012 Perform partial inlining.
2013
2014 fpre-ipa-mem-report
2015 Common Report Var(pre_ipa_mem_report)
2016 Report on memory allocation before interprocedural optimization.
2017
2018 fpost-ipa-mem-report
2019 Common Report Var(post_ipa_mem_report)
2020 Report on memory allocation before interprocedural optimization.
2021
2022 fpack-struct
2023 Common Report Var(flag_pack_struct) Optimization
2024 Pack structure members together without holes.
2025
2026 fpack-struct=
2027 Common RejectNegative Joined UInteger Optimization
2028 -fpack-struct=<number> Set initial maximum structure member alignment.
2029
2030 fpcc-struct-return
2031 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2032 Return small aggregates in memory, not registers.
2033
2034 fpeel-loops
2035 Common Report Var(flag_peel_loops) Optimization
2036 Perform loop peeling.
2037
2038 fpeephole
2039 Common Report Var(flag_no_peephole,0) Optimization
2040 Enable machine specific peephole optimizations.
2041
2042 fpeephole2
2043 Common Report Var(flag_peephole2) Optimization
2044 Enable an RTL peephole pass before sched2.
2045
2046 fPIC
2047 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2048 Generate position-independent code if possible (large mode).
2049
2050 fPIE
2051 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2052 Generate position-independent code for executables if possible (large mode).
2053
2054 fpic
2055 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2056 Generate position-independent code if possible (small mode).
2057
2058 fpie
2059 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2060 Generate position-independent code for executables if possible (small mode).
2061
2062 fplt
2063 Common Report Var(flag_plt) Init(1) Optimization
2064 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2065
2066 fplugin=
2067 Common Joined RejectNegative Var(common_deferred_options) Defer
2068 Specify a plugin to load.
2069
2070 fplugin-arg-
2071 Common Joined RejectNegative Var(common_deferred_options) Defer
2072 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2073
2074 fpredictive-commoning
2075 Common Report Var(flag_predictive_commoning) Optimization
2076 Run predictive commoning optimization.
2077
2078 fprefetch-loop-arrays
2079 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2080 Generate prefetch instructions, if available, for arrays in loops.
2081
2082 fprofile
2083 Common Report Var(profile_flag)
2084 Enable basic program profiling code.
2085
2086 fprofile-abs-path
2087 Common Report Var(profile_abs_path_flag)
2088 Generate absolute source path names for gcov.
2089
2090 fprofile-arcs
2091 Common Report Var(profile_arc_flag)
2092 Insert arc-based program profiling code.
2093
2094 fprofile-dir=
2095 Common Joined RejectNegative Var(profile_data_prefix)
2096 Set the top-level directory for storing the profile data.
2097 The default is 'pwd'.
2098
2099 fprofile-note=
2100 Common Joined RejectNegative Var(profile_note_location)
2101 Select the name for storing the profile note file.
2102
2103 fprofile-correction
2104 Common Report Var(flag_profile_correction)
2105 Enable correction of flow inconsistent profile data input.
2106
2107 fprofile-update=
2108 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2109 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2110
2111 fprofile-filter-files=
2112 Common Joined RejectNegative Var(flag_profile_filter_files)
2113 Instrument only functions from files where names match any regular expression (separated by a semi-colon).
2114
2115 fprofile-exclude-files=
2116 Common Joined RejectNegative Var(flag_profile_exclude_files)
2117 Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon).
2118
2119 Enum
2120 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2121
2122 EnumValue
2123 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2124
2125 EnumValue
2126 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2127
2128 EnumValue
2129 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2130
2131 fprofile-generate
2132 Common
2133 Enable common options for generating profile info for profile feedback directed optimizations.
2134
2135 fprofile-generate=
2136 Common Joined RejectNegative
2137 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2138
2139 fprofile-use
2140 Common Var(flag_profile_use)
2141 Enable common options for performing profile feedback directed optimizations.
2142
2143 fprofile-use=
2144 Common Joined RejectNegative
2145 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2146
2147 fprofile-values
2148 Common Report Var(flag_profile_values)
2149 Insert code to profile values of expressions.
2150
2151 fprofile-report
2152 Common Report Var(profile_report)
2153 Report on consistency of profile.
2154
2155 fprofile-reorder-functions
2156 Common Report Var(flag_profile_reorder_functions)
2157 Enable function reordering that improves code placement.
2158
2159 fpatchable-function-entry=
2160 Common Joined Optimization
2161 Insert NOP instructions at each function entry.
2162
2163 frandom-seed
2164 Common Var(common_deferred_options) Defer
2165
2166 frandom-seed=
2167 Common Joined RejectNegative Var(common_deferred_options) Defer
2168 -frandom-seed=<string> Make compile reproducible using <string>.
2169
2170 ; This switch causes the command line that was used to create an
2171 ; object file to be recorded into the object file. The exact format
2172 ; of this recording is target and binary file format dependent.
2173 ; It is related to the -fverbose-asm switch, but that switch only
2174 ; records information in the assembler output file as comments, so
2175 ; they never reach the object file.
2176 frecord-gcc-switches
2177 Common Report Var(flag_record_gcc_switches)
2178 Record gcc command line switches in the object file.
2179
2180 freg-struct-return
2181 Common Report Var(flag_pcc_struct_return,0) Optimization
2182 Return small aggregates in registers.
2183
2184 fregmove
2185 Common Ignore
2186 Does nothing. Preserved for backward compatibility.
2187
2188 flifetime-dse
2189 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2190 Tell DSE that the storage for a C++ object is dead when the constructor
2191 starts and when the destructor finishes.
2192
2193 flifetime-dse=
2194 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2195
2196 flive-patching
2197 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2198
2199 flive-patching=
2200 Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2201 -flive-patching=[inline-only-static|inline-clone] Control IPA
2202 optimizations to provide a safe compilation for live-patching. At the same
2203 time, provides multiple-level control on the enabled IPA optimizations.
2204
2205 Enum
2206 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2207
2208 EnumValue
2209 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2210
2211 EnumValue
2212 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2213
2214 fallocation-dce
2215 Common Report Var(flag_allocation_dce) Init(1) Optimization
2216 Tell DCE to remove unused C++ allocations.
2217
2218 flive-range-shrinkage
2219 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2220 Relief of register pressure through live range shrinkage.
2221
2222 frename-registers
2223 Common Report Var(flag_rename_registers) Init(2) Optimization
2224 Perform a register renaming optimization pass.
2225
2226 fschedule-fusion
2227 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2228 Perform a target dependent instruction fusion optimization pass.
2229
2230 freorder-blocks
2231 Common Report Var(flag_reorder_blocks) Optimization
2232 Reorder basic blocks to improve code placement.
2233
2234 freorder-blocks-algorithm=
2235 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2236 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2237
2238 Enum
2239 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2240
2241 EnumValue
2242 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2243
2244 EnumValue
2245 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2246
2247 freorder-blocks-and-partition
2248 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2249 Reorder basic blocks and partition into hot and cold sections.
2250
2251 freorder-functions
2252 Common Report Var(flag_reorder_functions) Optimization
2253 Reorder functions to improve code placement.
2254
2255 frerun-cse-after-loop
2256 Common Report Var(flag_rerun_cse_after_loop) Optimization
2257 Add a common subexpression elimination pass after loop optimizations.
2258
2259 frerun-loop-opt
2260 Common Ignore
2261 Does nothing. Preserved for backward compatibility.
2262
2263 frounding-math
2264 Common Report Var(flag_rounding_math) Optimization SetByCombined
2265 Disable optimizations that assume default FP rounding behavior.
2266
2267 fsched-interblock
2268 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2269 Enable scheduling across basic blocks.
2270
2271 fsched-pressure
2272 Common Report Var(flag_sched_pressure) Init(0) Optimization
2273 Enable register pressure sensitive insn scheduling.
2274
2275 fsched-spec
2276 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2277 Allow speculative motion of non-loads.
2278
2279 fsched-spec-load
2280 Common Report Var(flag_schedule_speculative_load) Optimization
2281 Allow speculative motion of some loads.
2282
2283 fsched-spec-load-dangerous
2284 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2285 Allow speculative motion of more loads.
2286
2287 fsched-verbose=
2288 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2289 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2290
2291 fsched2-use-superblocks
2292 Common Report Var(flag_sched2_use_superblocks) Optimization
2293 If scheduling post reload, do superblock scheduling.
2294
2295 fsched2-use-traces
2296 Common Ignore
2297 Does nothing. Preserved for backward compatibility.
2298
2299 fschedule-insns
2300 Common Report Var(flag_schedule_insns) Optimization
2301 Reschedule instructions before register allocation.
2302
2303 fschedule-insns2
2304 Common Report Var(flag_schedule_insns_after_reload) Optimization
2305 Reschedule instructions after register allocation.
2306
2307 ; This flag should be on when a target implements non-trivial
2308 ; scheduling hooks, maybe saving some information for its own sake.
2309 ; On IA64, for example, this is used for correct bundling.
2310 fselective-scheduling
2311 Common Report Var(flag_selective_scheduling) Optimization
2312 Schedule instructions using selective scheduling algorithm.
2313
2314 fselective-scheduling2
2315 Common Report Var(flag_selective_scheduling2) Optimization
2316 Run selective scheduling after reload.
2317
2318 fself-test=
2319 Common Undocumented Joined Var(flag_self_test)
2320 Run self-tests, using the given path to locate test files.
2321
2322 fsel-sched-pipelining
2323 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2324 Perform software pipelining of inner loops during selective scheduling.
2325
2326 fsel-sched-pipelining-outer-loops
2327 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2328 Perform software pipelining of outer loops during selective scheduling.
2329
2330 fsel-sched-reschedule-pipelined
2331 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2332 Reschedule pipelined regions without pipelining.
2333
2334 fsemantic-interposition
2335 Common Report Var(flag_semantic_interposition) Init(1)
2336 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2337
2338 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2339 ; of stalled insns into the ready list.
2340 fsched-stalled-insns
2341 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2342 Allow premature scheduling of queued insns.
2343
2344 fsched-stalled-insns=
2345 Common RejectNegative Joined UInteger Optimization
2346 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2347
2348 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2349 ; be examined for a dependency on a stalled insn that is candidate for
2350 ; premature removal from the queue of stalled insns into the ready list (has
2351 ; an effect only if the flag 'sched_stalled_insns' is set).
2352 fsched-stalled-insns-dep
2353 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2354 Set dependence distance checking in premature scheduling of queued insns.
2355
2356 fsched-stalled-insns-dep=
2357 Common RejectNegative Joined UInteger Optimization
2358 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2359
2360 fsched-group-heuristic
2361 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2362 Enable the group heuristic in the scheduler.
2363
2364 fsched-critical-path-heuristic
2365 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2366 Enable the critical path heuristic in the scheduler.
2367
2368 fsched-spec-insn-heuristic
2369 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2370 Enable the speculative instruction heuristic in the scheduler.
2371
2372 fsched-rank-heuristic
2373 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2374 Enable the rank heuristic in the scheduler.
2375
2376 fsched-last-insn-heuristic
2377 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2378 Enable the last instruction heuristic in the scheduler.
2379
2380 fsched-dep-count-heuristic
2381 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2382 Enable the dependent count heuristic in the scheduler.
2383
2384 fsection-anchors
2385 Common Report Var(flag_section_anchors) Optimization
2386 Access data in the same section from shared anchor points.
2387
2388 fsee
2389 Common Ignore
2390 Does nothing. Preserved for backward compatibility.
2391
2392 fzee
2393 Common Ignore
2394 Does nothing. Preserved for backward compatibility.
2395
2396 free
2397 Common Report Var(flag_ree) Init(0)
2398 Turn on Redundant Extensions Elimination pass.
2399
2400 fshow-column
2401 Common Report Var(flag_show_column) Init(1)
2402 Show column numbers in diagnostics, when available. Default on.
2403
2404 fshrink-wrap
2405 Common Report Var(flag_shrink_wrap) Optimization
2406 Emit function prologues only before parts of the function that need it,
2407 rather than at the top of the function.
2408
2409 fshrink-wrap-separate
2410 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2411 Shrink-wrap parts of the prologue and epilogue separately.
2412
2413 fsignaling-nans
2414 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2415 Disable optimizations observable by IEEE signaling NaNs.
2416
2417 fsigned-zeros
2418 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2419 Disable floating point optimizations that ignore the IEEE signedness of zero.
2420
2421 fsingle-precision-constant
2422 Common Report Var(flag_single_precision_constant) Optimization
2423 Convert floating point constants to single precision constants.
2424
2425 fsplit-ivs-in-unroller
2426 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2427 Split lifetimes of induction variables when loops are unrolled.
2428
2429 fsplit-stack
2430 Common Report Var(flag_split_stack) Init(-1)
2431 Generate discontiguous stack frames.
2432
2433 fsplit-wide-types
2434 Common Report Var(flag_split_wide_types) Optimization
2435 Split wide types into independent registers.
2436
2437 fsplit-wide-types-early
2438 Common Report Var(flag_split_wide_types_early) Optimization
2439 Split wide types into independent registers earlier.
2440
2441 fssa-backprop
2442 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2443 Enable backward propagation of use properties at the SSA level.
2444
2445 fssa-phiopt
2446 Common Report Var(flag_ssa_phiopt) Optimization
2447 Optimize conditional patterns using SSA PHI nodes.
2448
2449 fstdarg-opt
2450 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2451 Optimize amount of stdarg registers saved to stack at start of function.
2452
2453 fvariable-expansion-in-unroller
2454 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2455 Apply variable expansion when loops are unrolled.
2456
2457 fstack-check=
2458 Common Report RejectNegative Joined Optimization
2459 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2460
2461 fstack-check
2462 Common Alias(fstack-check=, specific, no)
2463 Insert stack checking code into the program. Same as -fstack-check=specific.
2464
2465 fstack-clash-protection
2466 Common Report Var(flag_stack_clash_protection) Optimization
2467 Insert code to probe each page of stack space as it is allocated to protect
2468 from stack-clash style attacks.
2469
2470 fstack-limit
2471 Common Var(common_deferred_options) Defer
2472
2473 fstack-limit-register=
2474 Common RejectNegative Joined Var(common_deferred_options) Defer
2475 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2476
2477 fstack-limit-symbol=
2478 Common RejectNegative Joined Var(common_deferred_options) Defer
2479 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2480
2481 fstack-protector
2482 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2483 Use propolice as a stack protection method.
2484
2485 fstack-protector-all
2486 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2487 Use a stack protection method for every function.
2488
2489 fstack-protector-strong
2490 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2491 Use a smart stack protection method for certain functions.
2492
2493 fstack-protector-explicit
2494 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2495 Use stack protection method only for functions with the stack_protect attribute.
2496
2497 fstack-usage
2498 Common RejectNegative Var(flag_stack_usage)
2499 Output stack usage information on a per-function basis.
2500
2501 fstrength-reduce
2502 Common Ignore
2503 Does nothing. Preserved for backward compatibility.
2504
2505 ; Nonzero if we should do (language-dependent) alias analysis.
2506 ; Typically, this analysis will assume that expressions of certain
2507 ; types do not alias expressions of certain other types. Only used
2508 ; if alias analysis (in general) is enabled.
2509 fstrict-aliasing
2510 Common Report Var(flag_strict_aliasing) Optimization
2511 Assume strict aliasing rules apply.
2512
2513 fstrict-overflow
2514 Common Report
2515 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2516
2517 fsync-libcalls
2518 Common Report Var(flag_sync_libcalls) Init(1)
2519 Implement __atomic operations via libcalls to legacy __sync functions.
2520
2521 fsyntax-only
2522 Common Report Var(flag_syntax_only)
2523 Check for syntax errors, then stop.
2524
2525 ftest-coverage
2526 Common Report Var(flag_test_coverage)
2527 Create data files needed by \"gcov\".
2528
2529 fthread-jumps
2530 Common Report Var(flag_thread_jumps) Optimization
2531 Perform jump threading optimizations.
2532
2533 ftime-report
2534 Common Report Var(time_report)
2535 Report the time taken by each compiler pass.
2536
2537 ftime-report-details
2538 Common Report Var(time_report_details)
2539 Record times taken by sub-phases separately.
2540
2541 ftls-model=
2542 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2543 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2544
2545 Enum
2546 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2547
2548 EnumValue
2549 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2550
2551 EnumValue
2552 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2553
2554 EnumValue
2555 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2556
2557 EnumValue
2558 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2559
2560 ftoplevel-reorder
2561 Common Report Var(flag_toplevel_reorder) Init(2)
2562 Reorder top level functions, variables, and asms.
2563
2564 ftracer
2565 Common Report Var(flag_tracer) Optimization
2566 Perform superblock formation via tail duplication.
2567
2568 ftrampolines
2569 Common Report Var(flag_trampolines) Init(0)
2570 For targets that normally need trampolines for nested functions, always
2571 generate them instead of using descriptors.
2572
2573 ; Zero means that floating-point math operations cannot generate a
2574 ; (user-visible) trap. This is the case, for example, in nonstop
2575 ; IEEE 754 arithmetic.
2576 ftrapping-math
2577 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2578 Assume floating-point operations can trap.
2579
2580 ftrapv
2581 Common Report Var(flag_trapv) Optimization
2582 Trap for signed overflow in addition, subtraction and multiplication.
2583
2584 ftree-ccp
2585 Common Report Var(flag_tree_ccp) Optimization
2586 Enable SSA-CCP optimization on trees.
2587
2588 ftree-bit-ccp
2589 Common Report Var(flag_tree_bit_ccp) Optimization
2590 Enable SSA-BIT-CCP optimization on trees.
2591
2592 ftree-store-ccp
2593 Common Ignore
2594 Does nothing. Preserved for backward compatibility.
2595
2596 ftree-ch
2597 Common Report Var(flag_tree_ch) Optimization
2598 Enable loop header copying on trees.
2599
2600 ftree-coalesce-inlined-vars
2601 Common Ignore RejectNegative
2602 Does nothing. Preserved for backward compatibility.
2603
2604 ftree-coalesce-vars
2605 Common Report Var(flag_tree_coalesce_vars) Optimization
2606 Enable SSA coalescing of user variables.
2607
2608 ftree-copyrename
2609 Common Ignore
2610 Does nothing. Preserved for backward compatibility.
2611
2612 ftree-copy-prop
2613 Common Report Var(flag_tree_copy_prop) Optimization
2614 Enable copy propagation on trees.
2615
2616 ftree-store-copy-prop
2617 Common Ignore
2618 Does nothing. Preserved for backward compatibility.
2619
2620 ftree-cselim
2621 Common Report Var(flag_tree_cselim) Init(2) Optimization
2622 Transform condition stores into unconditional ones.
2623
2624 ftree-switch-conversion
2625 Common Report Var(flag_tree_switch_conversion) Optimization
2626 Perform conversions of switch initializations.
2627
2628 ftree-dce
2629 Common Report Var(flag_tree_dce) Optimization
2630 Enable SSA dead code elimination optimization on trees.
2631
2632 ftree-dominator-opts
2633 Common Report Var(flag_tree_dom) Optimization
2634 Enable dominator optimizations.
2635
2636 ftree-tail-merge
2637 Common Report Var(flag_tree_tail_merge) Optimization
2638 Enable tail merging on trees.
2639
2640 ftree-dse
2641 Common Report Var(flag_tree_dse) Optimization
2642 Enable dead store elimination.
2643
2644 ftree-forwprop
2645 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2646 Enable forward propagation on trees.
2647
2648 ftree-fre
2649 Common Report Var(flag_tree_fre) Optimization
2650 Enable Full Redundancy Elimination (FRE) on trees.
2651
2652 foptimize-strlen
2653 Common Report Var(flag_optimize_strlen) Optimization
2654 Enable string length optimizations on trees.
2655
2656 fisolate-erroneous-paths-dereference
2657 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2658 Detect paths that trigger erroneous or undefined behavior due to
2659 dereferencing a null pointer. Isolate those paths from the main control
2660 flow and turn the statement with erroneous or undefined behavior into a trap.
2661
2662 fisolate-erroneous-paths-attribute
2663 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2664 Detect paths that trigger erroneous or undefined behavior due to a null value
2665 being used in a way forbidden by a returns_nonnull or nonnull
2666 attribute. Isolate those paths from the main control flow and turn the
2667 statement with erroneous or undefined behavior into a trap.
2668
2669 ftree-loop-distribution
2670 Common Report Var(flag_tree_loop_distribution) Optimization
2671 Enable loop distribution on trees.
2672
2673 ftree-loop-distribute-patterns
2674 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2675 Enable loop distribution for patterns transformed into a library call.
2676
2677 ftree-loop-im
2678 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2679 Enable loop invariant motion on trees.
2680
2681 ftree-loop-linear
2682 Common Alias(floop-nest-optimize)
2683 Enable loop nest transforms. Same as -floop-nest-optimize.
2684
2685 ftree-loop-ivcanon
2686 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2687 Create canonical induction variables in loops.
2688
2689 ftree-loop-optimize
2690 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2691 Enable loop optimizations on tree level.
2692
2693 ftree-parallelize-loops=
2694 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2695 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2696
2697 ftree-phiprop
2698 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2699 Enable hoisting loads from conditional pointers.
2700
2701 ftree-pre
2702 Common Report Var(flag_tree_pre) Optimization
2703 Enable SSA-PRE optimization on trees.
2704
2705 ftree-partial-pre
2706 Common Report Var(flag_tree_partial_pre) Optimization
2707 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2708
2709 ftree-pta
2710 Common Report Var(flag_tree_pta) Optimization
2711 Perform function-local points-to analysis on trees.
2712
2713 ftree-reassoc
2714 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2715 Enable reassociation on tree level.
2716
2717 ftree-salias
2718 Common Ignore
2719 Does nothing. Preserved for backward compatibility.
2720
2721 ftree-sink
2722 Common Report Var(flag_tree_sink) Optimization
2723 Enable SSA code sinking on trees.
2724
2725 ftree-slsr
2726 Common Report Var(flag_tree_slsr) Optimization
2727 Perform straight-line strength reduction.
2728
2729 ftree-sra
2730 Common Report Var(flag_tree_sra) Optimization
2731 Perform scalar replacement of aggregates.
2732
2733 ftree-ter
2734 Common Report Var(flag_tree_ter) Optimization
2735 Replace temporary expressions in the SSA->normal pass.
2736
2737 ftree-lrs
2738 Common Report Var(flag_tree_live_range_split) Optimization
2739 Perform live range splitting during the SSA->normal pass.
2740
2741 ftree-vrp
2742 Common Report Var(flag_tree_vrp) Init(0) Optimization
2743 Perform Value Range Propagation on trees.
2744
2745 fsplit-paths
2746 Common Report Var(flag_split_paths) Init(0) Optimization
2747 Split paths leading to loop backedges.
2748
2749 funconstrained-commons
2750 Common Var(flag_unconstrained_commons) Optimization
2751 Assume common declarations may be overridden with ones with a larger
2752 trailing array.
2753
2754 funit-at-a-time
2755 Common Report Var(flag_unit_at_a_time) Init(1)
2756 Compile whole compilation unit at a time.
2757
2758 funroll-loops
2759 Common Report Var(flag_unroll_loops) Optimization
2760 Perform loop unrolling when iteration count is known.
2761
2762 funroll-all-loops
2763 Common Report Var(flag_unroll_all_loops) Optimization
2764 Perform loop unrolling for all loops.
2765
2766 ; Nonzero means that loop optimizer may assume that the induction variables
2767 ; that control loops do not overflow and that the loops with nontrivial
2768 ; exit condition are not infinite
2769 funsafe-loop-optimizations
2770 Common Ignore
2771 Does nothing. Preserved for backward compatibility.
2772
2773 fassociative-math
2774 Common Report Var(flag_associative_math) SetByCombined Optimization
2775 Allow optimization for floating-point arithmetic which may change the
2776 result of the operation due to rounding.
2777
2778 freciprocal-math
2779 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2780 Same as -fassociative-math for expressions which include division.
2781
2782 ; Nonzero means that unsafe floating-point math optimizations are allowed
2783 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2784 ; are allowed to assume that their arguments and results are "normal"
2785 ; (e.g., nonnegative for SQRT).
2786 funsafe-math-optimizations
2787 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2788 Allow math optimizations that may violate IEEE or ISO standards.
2789
2790 funswitch-loops
2791 Common Report Var(flag_unswitch_loops) Optimization
2792 Perform loop unswitching.
2793
2794 fsplit-loops
2795 Common Report Var(flag_split_loops) Optimization
2796 Perform loop splitting.
2797
2798 fversion-loops-for-strides
2799 Common Report Var(flag_version_loops_for_strides) Optimization
2800 Version loops based on whether indices have a stride of one.
2801
2802 funwind-tables
2803 Common Report Var(flag_unwind_tables) Optimization
2804 Just generate unwind tables for exception handling.
2805
2806 fuse-ld=bfd
2807 Common Driver Negative(fuse-ld=gold)
2808 Use the bfd linker instead of the default linker.
2809
2810 fuse-ld=gold
2811 Common Driver Negative(fuse-ld=bfd)
2812 Use the gold linker instead of the default linker.
2813
2814 fuse-ld=lld
2815 Common Driver Negative(fuse-ld=lld)
2816 Use the lld LLVM linker instead of the default linker.
2817
2818 fuse-linker-plugin
2819 Common Undocumented Var(flag_use_linker_plugin)
2820
2821 ; Positive if we should track variables, negative if we should run
2822 ; the var-tracking pass only to discard debug annotations, zero if
2823 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2824 ; will be set according to optimize, debug_info_level and debug_hooks
2825 ; in process_options ().
2826 fvar-tracking
2827 Common Report Var(flag_var_tracking) Init(2) PerFunction
2828 Perform variable tracking.
2829
2830 ; Positive if we should track variables at assignments, negative if
2831 ; we should run the var-tracking pass only to discard debug
2832 ; annotations. When flag_var_tracking_assignments ==
2833 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2834 fvar-tracking-assignments
2835 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2836 Perform variable tracking by annotating assignments.
2837
2838 ; Nonzero if we should toggle flag_var_tracking_assignments after
2839 ; processing options and computing its default. */
2840 fvar-tracking-assignments-toggle
2841 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2842 Toggle -fvar-tracking-assignments.
2843
2844 ; Positive if we should track uninitialized variables, negative if
2845 ; we should run the var-tracking pass only to discard debug
2846 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2847 ; will be set according to flag_var_tracking.
2848 fvar-tracking-uninit
2849 Common Report Var(flag_var_tracking_uninit) PerFunction
2850 Perform variable tracking and also tag variables that are uninitialized.
2851
2852 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2853 ftree-vectorize
2854 Common Report Optimization
2855 Enable vectorization on trees.
2856
2857 ftree-vectorizer-verbose=
2858 Common Joined RejectNegative Ignore
2859 Does nothing. Preserved for backward compatibility.
2860
2861 ftree-loop-vectorize
2862 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2863 Enable loop vectorization on trees.
2864
2865 ftree-slp-vectorize
2866 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2867 Enable basic block vectorization (SLP) on trees.
2868
2869 fvect-cost-model=
2870 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2871 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2872
2873 fsimd-cost-model=
2874 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2875 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2876
2877 Enum
2878 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2879
2880 EnumValue
2881 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2882
2883 EnumValue
2884 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2885
2886 EnumValue
2887 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2888
2889 fvect-cost-model
2890 Common Alias(fvect-cost-model=,dynamic,unlimited)
2891 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2892
2893 ftree-vect-loop-version
2894 Common Ignore
2895 Does nothing. Preserved for backward compatibility.
2896
2897 ftree-scev-cprop
2898 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2899 Enable copy propagation of scalar-evolution information.
2900
2901 ; -fverbose-asm causes extra commentary information to be produced in
2902 ; the generated assembly code (to make it more readable). This option
2903 ; is generally only of use to those who actually need to read the
2904 ; generated assembly code (perhaps while debugging the compiler itself).
2905 ; -fno-verbose-asm, the default, causes the extra information
2906 ; to not be added and is useful when comparing two assembler files.
2907 fverbose-asm
2908 Common Report Var(flag_verbose_asm)
2909 Add extra commentary to assembler output.
2910
2911 fvisibility=
2912 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2913 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2914
2915 Enum
2916 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2917
2918 EnumValue
2919 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2920
2921 EnumValue
2922 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2923
2924 EnumValue
2925 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2926
2927 EnumValue
2928 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2929
2930 fvtable-verify=
2931 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2932 Validate vtable pointers before using them.
2933
2934 Enum
2935 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2936
2937 EnumValue
2938 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2939
2940 EnumValue
2941 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2942
2943 EnumValue
2944 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2945
2946 fvtv-counts
2947 Common Var(flag_vtv_counts)
2948 Output vtable verification counters.
2949
2950 fvtv-debug
2951 Common Var(flag_vtv_debug)
2952 Output vtable verification pointer sets information.
2953
2954 fvpt
2955 Common Report Var(flag_value_profile_transformations) Optimization
2956 Use expression value profiles in optimizations.
2957
2958 fweb
2959 Common Report Var(flag_web) Init(2) Optimization
2960 Construct webs and split unrelated uses of single variable.
2961
2962 ftree-builtin-call-dce
2963 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2964 Enable conditional dead code elimination for builtin calls.
2965
2966 fwhole-program
2967 Common Report Var(flag_whole_program) Init(0)
2968 Perform whole program optimizations.
2969
2970 fwrapv-pointer
2971 Common Report Var(flag_wrapv_pointer) Optimization
2972 Assume pointer overflow wraps around.
2973
2974 fwrapv
2975 Common Report Var(flag_wrapv) Optimization
2976 Assume signed arithmetic overflow wraps around.
2977
2978 fzero-initialized-in-bss
2979 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2980 Put zero initialized data in the bss section.
2981
2982 g
2983 Common Driver RejectNegative JoinedOrMissing
2984 Generate debug information in default format.
2985
2986 gas-loc-support
2987 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2988 Assume assembler support for (DWARF2+) .loc directives.
2989
2990 gas-locview-support
2991 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2992 Assume assembler support for view in (DWARF2+) .loc directives.
2993
2994 gcoff
2995 Common Driver Deprecated
2996 Does nothing. Preserved for backward compatibility.
2997
2998 gcoff1
2999 Common Driver Deprecated
3000 Does nothing. Preserved for backward compatibility.
3001
3002 gcoff2
3003 Common Driver Deprecated
3004 Does nothing. Preserved for backward compatibility.
3005
3006 gcoff3
3007 Common Driver Deprecated
3008 Does nothing. Preserved for backward compatibility.
3009
3010 gcolumn-info
3011 Common Driver Var(debug_column_info,1) Init(1)
3012 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3013
3014 gdwarf
3015 Common Driver JoinedOrMissing Negative(gdwarf-)
3016 Generate debug information in default version of DWARF format.
3017
3018 gdwarf-
3019 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
3020 Generate debug information in DWARF v2 (or later) format.
3021
3022 ggdb
3023 Common Driver JoinedOrMissing
3024 Generate debug information in default extended format.
3025
3026 ginline-points
3027 Common Driver Var(debug_inline_points) Init(2)
3028 Generate extended entry point information for inlined functions.
3029
3030 ginternal-reset-location-views
3031 Common Driver Var(debug_internal_reset_location_views) Init(2)
3032 Compute locview reset points based on insn length estimates.
3033
3034 gno-
3035 RejectNegative Joined Undocumented
3036 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3037
3038 gno-pubnames
3039 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3040 Don't generate DWARF pubnames and pubtypes sections.
3041
3042 gpubnames
3043 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3044 Generate DWARF pubnames and pubtypes sections.
3045
3046 ggnu-pubnames
3047 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3048 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3049
3050 grecord-gcc-switches
3051 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3052 Record gcc command line switches in DWARF DW_AT_producer.
3053
3054 gsplit-dwarf
3055 Common Driver Var(dwarf_split_debug_info) Init(0)
3056 Generate debug information in separate .dwo files.
3057
3058 gstabs
3059 Common Driver JoinedOrMissing Negative(gstabs+)
3060 Generate debug information in STABS format.
3061
3062 gstabs+
3063 Common Driver JoinedOrMissing Negative(gvms)
3064 Generate debug information in extended STABS format.
3065
3066 gstatement-frontiers
3067 Common Driver Var(debug_nonbind_markers_p) Init(2)
3068 Emit progressive recommended breakpoint locations.
3069
3070 gstrict-dwarf
3071 Common Driver Report Var(dwarf_strict) Init(0)
3072 Don't emit DWARF additions beyond selected version.
3073
3074 gdescribe-dies
3075 Common Driver Report Var(flag_describe_dies) Init(0)
3076 Add description attributes to some DWARF DIEs that have no name attribute.
3077
3078 gtoggle
3079 Common Driver Report Var(flag_gtoggle)
3080 Toggle debug information generation.
3081
3082 gvariable-location-views
3083 Common Driver Var(debug_variable_location_views, 1) Init(2)
3084 Augment variable location lists with progressive views.
3085
3086 gvariable-location-views=incompat5
3087 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3088
3089 gvms
3090 Common Driver JoinedOrMissing Negative(gxcoff)
3091 Generate debug information in VMS format.
3092
3093 gxcoff
3094 Common Driver JoinedOrMissing Negative(gxcoff+)
3095 Generate debug information in XCOFF format.
3096
3097 gxcoff+
3098 Common Driver JoinedOrMissing Negative(gdwarf)
3099 Generate debug information in extended XCOFF format.
3100
3101 Enum
3102 Name(compressed_debug_sections) Type(int)
3103
3104 ; Since -gz= is completely handled in specs, the values aren't used and we
3105 ; assign arbitrary constants.
3106 EnumValue
3107 Enum(compressed_debug_sections) String(none) Value(0)
3108
3109 EnumValue
3110 Enum(compressed_debug_sections) String(zlib) Value(1)
3111
3112 EnumValue
3113 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3114
3115 gz
3116 Common Driver
3117 Generate compressed debug sections.
3118
3119 gz=
3120 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3121 -gz=<format> Generate compressed debug sections in format <format>.
3122
3123 h
3124 Driver Joined Separate
3125
3126 iplugindir=
3127 Common Joined Var(plugindir_string) Init(0)
3128 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3129
3130 imultiarch
3131 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3132 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3133
3134 l
3135 Driver Joined Separate
3136
3137 n
3138 Driver
3139
3140 no-canonical-prefixes
3141 Driver
3142
3143 nodefaultlibs
3144 Driver
3145
3146 nostartfiles
3147 Driver
3148
3149 nolibc
3150 Driver
3151
3152 nostdlib
3153 Driver
3154
3155 o
3156 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3157 -o <file> Place output into <file>.
3158
3159 p
3160 Common Var(profile_flag)
3161 Enable function profiling.
3162
3163 pass-exit-codes
3164 Driver Var(pass_exit_codes)
3165
3166 pedantic
3167 Common Alias(Wpedantic)
3168
3169 pedantic-errors
3170 Common Var(flag_pedantic_errors)
3171 Like -pedantic but issue them as errors.
3172
3173 pg
3174 Driver
3175
3176 pipe
3177 Driver Var(use_pipes)
3178
3179 print-file-name=
3180 Driver JoinedOrMissing Var(print_file_name)
3181
3182 print-libgcc-file-name
3183 Driver
3184
3185 print-multi-directory
3186 Driver Var(print_multi_directory)
3187
3188 print-multi-lib
3189 Driver Var(print_multi_lib)
3190
3191 print-multi-os-directory
3192 Driver Var(print_multi_os_directory)
3193
3194 print-multiarch
3195 Driver Var(print_multiarch)
3196
3197 print-prog-name=
3198 Driver JoinedOrMissing Var(print_prog_name)
3199
3200 print-search-dirs
3201 Driver Var(print_search_dirs)
3202
3203 print-sysroot
3204 Driver Var(print_sysroot)
3205
3206 print-sysroot-headers-suffix
3207 Driver Var(print_sysroot_headers_suffix)
3208
3209 quiet
3210 Common Var(quiet_flag) RejectDriver
3211 Do not display functions compiled or elapsed time.
3212
3213 r
3214 Driver
3215
3216 s
3217 Driver
3218
3219 save-temps
3220 Driver
3221
3222 save-temps=
3223 Driver Joined
3224
3225 t
3226 Driver
3227
3228 time
3229 Driver Var(report_times)
3230
3231 time=
3232 Driver JoinedOrMissing
3233
3234 u
3235 Driver Joined Separate
3236
3237 undef
3238 Driver
3239 ; C option, but driver must not handle as "-u ndef".
3240
3241 v
3242 Common Driver Var(verbose_flag)
3243 Enable verbose output.
3244
3245 version
3246 Common Var(version_flag) RejectDriver
3247 Display the compiler's version.
3248
3249 w
3250 Common Var(inhibit_warnings)
3251 Suppress warnings.
3252
3253 wrapper
3254 Driver Separate Var(wrapper_string)
3255
3256 x
3257 Driver Joined Separate
3258
3259 shared
3260 Driver RejectNegative Negative(static-pie)
3261 Create a shared library.
3262
3263 shared-libgcc
3264 Driver
3265
3266 specs
3267 Driver Separate Alias(specs=)
3268
3269 specs=
3270 Driver Joined
3271
3272 static
3273 Driver
3274
3275 static-libgcc
3276 Driver
3277
3278 static-libgfortran
3279 Driver
3280 ; Documented for Fortran, but always accepted by driver.
3281
3282 static-libstdc++
3283 Driver
3284
3285 static-libgo
3286 Driver
3287 ; Documented for Go, but always accepted by driver.
3288
3289 static-libasan
3290 Driver
3291
3292 static-libtsan
3293 Driver
3294
3295 static-liblsan
3296 Driver
3297
3298 static-libubsan
3299 Driver
3300
3301 symbolic
3302 Driver
3303
3304 no-pie
3305 Driver RejectNegative Negative(shared)
3306 Don't create a dynamically linked position independent executable.
3307
3308 pie
3309 Driver RejectNegative Negative(no-pie)
3310 Create a dynamically linked position independent executable.
3311
3312 static-pie
3313 Driver RejectNegative Negative(pie)
3314 Create a static position independent executable.
3315
3316 z
3317 Driver Joined Separate
3318
3319 fipa-ra
3320 Common Report Var(flag_ipa_ra) Optimization
3321 Use caller save register across calls if possible.
3322
3323 ; This comment is to ensure we retain the blank line above.