]> git.ipfire.org Git - thirdparty/gcc.git/blob - gcc/common.opt
2019-10-18 Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
[thirdparty/gcc.git] / gcc / common.opt
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 fallow-store-data-races
997 Common Report Var(flag_store_data_races) Optimization
998 Allow the compiler to introduce new data races on stores.
999
1000 fargument-alias
1001 Common Ignore
1002 Does nothing. Preserved for backward compatibility.
1003
1004 fargument-noalias
1005 Common Ignore
1006 Does nothing. Preserved for backward compatibility.
1007
1008 fargument-noalias-global
1009 Common Ignore
1010 Does nothing. Preserved for backward compatibility.
1011
1012 fargument-noalias-anything
1013 Common Ignore
1014 Does nothing. Preserved for backward compatibility.
1015
1016 fsanitize=
1017 Common Driver Report Joined
1018 Select what to sanitize.
1019
1020 fsanitize-coverage=
1021 Common Report Joined
1022 Select type of coverage sanitization.
1023
1024 fasan-shadow-offset=
1025 Common Joined RejectNegative Var(common_deferred_options) Defer
1026 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1027
1028 fsanitize-sections=
1029 Common Joined RejectNegative Var(common_deferred_options) Defer
1030 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1031 in user-defined sections.
1032
1033 fsanitize-recover=
1034 Common Report Joined
1035 After diagnosing undefined behavior attempt to continue execution.
1036
1037 fsanitize-recover
1038 Common Report
1039 This switch is deprecated; use -fsanitize-recover= instead.
1040
1041 fsanitize-address-use-after-scope
1042 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1043
1044 fsanitize-undefined-trap-on-error
1045 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1046 Use trap instead of a library function for undefined behavior sanitization.
1047
1048 fasynchronous-unwind-tables
1049 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1050 Generate unwind tables that are exact at each instruction boundary.
1051
1052 fauto-inc-dec
1053 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1054 Generate auto-inc/dec instructions.
1055
1056 fauto-profile
1057 Common Report Var(flag_auto_profile)
1058 Use sample profile information for call graph node weights. The default
1059 profile file is fbdata.afdo in 'pwd'.
1060
1061 fauto-profile=
1062 Common Joined RejectNegative Var(auto_profile_file)
1063 Use sample profile information for call graph node weights. The profile
1064 file is specified in the argument.
1065
1066 ; -fcheck-bounds causes gcc to generate array bounds checks.
1067 ; For C, C++ and ObjC: defaults off.
1068 ; For Java: defaults to on.
1069 ; For Fortran: defaults to off.
1070 fbounds-check
1071 Common Report Var(flag_bounds_check)
1072 Generate code to check bounds before indexing arrays.
1073
1074 fbranch-count-reg
1075 Common Report Var(flag_branch_on_count_reg) Optimization
1076 Replace add, compare, branch with branch on count register.
1077
1078 fbranch-probabilities
1079 Common Report Var(flag_branch_probabilities) Optimization
1080 Use profiling information for branch probabilities.
1081
1082 fbranch-target-load-optimize
1083 Common Ignore
1084 Does nothing. Preserved for backward compatibility.
1085
1086 fbranch-target-load-optimize2
1087 Common Ignore
1088 Does nothing. Preserved for backward compatibility.
1089
1090 fbtr-bb-exclusive
1091 Common Ignore
1092 Does nothing. Preserved for backward compatibility.
1093
1094 fcall-saved-
1095 Common Joined RejectNegative Var(common_deferred_options) Defer
1096 -fcall-saved-<register> Mark <register> as being preserved across functions.
1097
1098 fcall-used-
1099 Common Joined RejectNegative Var(common_deferred_options) Defer
1100 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1101
1102 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1103 ; be saved across function calls, if that produces overall better code.
1104 ; Optional now, so people can test it.
1105 fcaller-saves
1106 Common Report Var(flag_caller_saves) Optimization
1107 Save registers around function calls.
1108
1109 fcheck-data-deps
1110 Common Ignore
1111 This switch is deprecated; do not use.
1112
1113 fcheck-new
1114 Common Var(flag_check_new)
1115 Check the return value of new in C++.
1116
1117 fchecking
1118 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1119 Perform internal consistency checkings.
1120
1121 fchecking=
1122 Common Joined RejectNegative UInteger Var(flag_checking)
1123 Perform internal consistency checkings.
1124
1125 fcode-hoisting
1126 Common Report Var(flag_code_hoisting) Optimization
1127 Enable code hoisting.
1128
1129 fcombine-stack-adjustments
1130 Common Report Var(flag_combine_stack_adjustments) Optimization
1131 Looks for opportunities to reduce stack adjustments and stack references.
1132
1133 fcommon
1134 Common Report Var(flag_no_common,0)
1135 Do not put uninitialized globals in the common section.
1136
1137 fcompare-debug
1138 Driver
1139 ; Converted by the driver to -fcompare-debug= options.
1140
1141 fcompare-debug=
1142 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1143 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1144
1145 fcompare-debug-second
1146 Common Driver RejectNegative Var(flag_compare_debug)
1147 Run only the second compilation of -fcompare-debug.
1148
1149 fcompare-elim
1150 Common Report Var(flag_compare_elim_after_reload) Optimization
1151 Perform comparison elimination after register allocation has finished.
1152
1153 fconserve-stack
1154 Common Var(flag_conserve_stack) Optimization
1155 Do not perform optimizations increasing noticeably stack usage.
1156
1157 fcprop-registers
1158 Common Report Var(flag_cprop_registers) Optimization
1159 Perform a register copy-propagation optimization pass.
1160
1161 fcrossjumping
1162 Common Report Var(flag_crossjumping) Optimization
1163 Perform cross-jumping optimization.
1164
1165 fcse-follow-jumps
1166 Common Report Var(flag_cse_follow_jumps) Optimization
1167 When running CSE, follow jumps to their targets.
1168
1169 fcse-skip-blocks
1170 Common Ignore
1171 Does nothing. Preserved for backward compatibility.
1172
1173 fcx-limited-range
1174 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1175 Omit range reduction step when performing complex division.
1176
1177 fcx-fortran-rules
1178 Common Report Var(flag_cx_fortran_rules) Optimization
1179 Complex multiplication and division follow Fortran rules.
1180
1181 fdata-sections
1182 Common Report Var(flag_data_sections)
1183 Place data items into their own section.
1184
1185 fdbg-cnt-list
1186 Common Report Var(common_deferred_options) Defer
1187 List all available debugging counters with their limits and counts.
1188
1189 fdbg-cnt=
1190 Common RejectNegative Joined Var(common_deferred_options) Defer
1191 -fdbg-cnt=<counter>[:<lower_limit>]:<upper_limit>[,<counter>:...] Set the debug counter limit.
1192
1193 fdebug-prefix-map=
1194 Common Joined RejectNegative Var(common_deferred_options) Defer
1195 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1196
1197 ffile-prefix-map=
1198 Common Joined RejectNegative Var(common_deferred_options) Defer
1199 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1200
1201 fdebug-types-section
1202 Common Report Var(flag_debug_types_section) Init(0)
1203 Output .debug_types section when using DWARF v4 debuginfo.
1204
1205 ; Nonzero for -fdefer-pop: don't pop args after each function call
1206 ; instead save them up to pop many calls' args with one insns.
1207 fdefer-pop
1208 Common Report Var(flag_defer_pop) Optimization
1209 Defer popping functions args from stack until later.
1210
1211 fdelayed-branch
1212 Common Report Var(flag_delayed_branch) Optimization
1213 Attempt to fill delay slots of branch instructions.
1214
1215 fdelete-dead-exceptions
1216 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1217 Delete dead instructions that may throw exceptions.
1218
1219 fdelete-null-pointer-checks
1220 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1221 Delete useless null pointer checks.
1222
1223 fdevirtualize-at-ltrans
1224 Common Report Var(flag_ltrans_devirtualize)
1225 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1226
1227 fdevirtualize-speculatively
1228 Common Report Var(flag_devirtualize_speculatively) Optimization
1229 Perform speculative devirtualization.
1230
1231 fdevirtualize
1232 Common Report Var(flag_devirtualize) Optimization
1233 Try to convert virtual calls to direct ones.
1234
1235 fdiagnostics-show-location=
1236 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1237 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1238
1239 ; Required for these enum values.
1240 SourceInclude
1241 pretty-print.h
1242
1243 Enum
1244 Name(diagnostic_prefixing_rule) Type(int)
1245
1246 EnumValue
1247 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1248
1249 EnumValue
1250 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1251
1252 fdiagnostics-show-caret
1253 Common Var(flag_diagnostics_show_caret) Init(1)
1254 Show the source line with a caret indicating the column.
1255
1256 fdiagnostics-show-labels
1257 Common Var(flag_diagnostics_show_labels) Init(1)
1258 Show labels annotating ranges of source code when showing source.
1259
1260 fdiagnostics-show-line-numbers
1261 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1262 Show line numbers in the left margin when showing source.
1263
1264 fdiagnostics-color
1265 Common Alias(fdiagnostics-color=,always,never)
1266 ;
1267
1268 fdiagnostics-color=
1269 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1270 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1271
1272 ; Required for these enum values.
1273 SourceInclude
1274 diagnostic-color.h
1275
1276 Enum
1277 Name(diagnostic_color_rule) Type(int)
1278
1279 EnumValue
1280 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1281
1282 EnumValue
1283 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1284
1285 EnumValue
1286 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1287
1288 fdiagnostics-urls=
1289 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1290 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1291
1292 ; Required for these enum values.
1293 SourceInclude
1294 diagnostic-url.h
1295
1296 Enum
1297 Name(diagnostic_url_rule) Type(int)
1298
1299 EnumValue
1300 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1301
1302 EnumValue
1303 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1304
1305 EnumValue
1306 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1307
1308 fdiagnostics-format=
1309 Common Joined RejectNegative Enum(diagnostics_output_format)
1310 -fdiagnostics-format=[text|json] Select output format.
1311
1312 ; Required for these enum values.
1313 SourceInclude
1314 diagnostic.h
1315
1316 Enum
1317 Name(diagnostics_output_format) Type(int)
1318
1319 EnumValue
1320 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1321
1322 EnumValue
1323 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1324
1325 fdiagnostics-parseable-fixits
1326 Common Var(flag_diagnostics_parseable_fixits)
1327 Print fix-it hints in machine-readable form.
1328
1329 fdiagnostics-generate-patch
1330 Common Var(flag_diagnostics_generate_patch)
1331 Print fix-it hints to stderr in unified diff format.
1332
1333 fdiagnostics-show-option
1334 Common Var(flag_diagnostics_show_option) Init(1)
1335 Amend appropriate diagnostic messages with the command line option that controls them.
1336
1337 fdiagnostics-minimum-margin-width=
1338 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1339 Set minimum width of left margin of source code when showing source.
1340
1341 fdisable-
1342 Common Joined RejectNegative Var(common_deferred_options) Defer
1343 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1344
1345 fenable-
1346 Common Joined RejectNegative Var(common_deferred_options) Defer
1347 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1348
1349 fdump-
1350 Common Joined RejectNegative Var(common_deferred_options) Defer
1351 -fdump-<type> Dump various compiler internals to a file.
1352
1353 fdump-final-insns
1354 Driver RejectNegative
1355
1356 fdump-final-insns=
1357 Common RejectNegative Joined Var(flag_dump_final_insns)
1358 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1359
1360 fdump-go-spec=
1361 Common RejectNegative Joined Var(flag_dump_go_spec)
1362 -fdump-go-spec=filename Write all declarations to file as Go code.
1363
1364 fdump-noaddr
1365 Common Report Var(flag_dump_noaddr)
1366 Suppress output of addresses in debugging dumps.
1367
1368 freport-bug
1369 Common Driver Var(flag_report_bug)
1370 Collect and dump debug information into temporary file if ICE in C/C++
1371 compiler occurred.
1372
1373 fdump-internal-locations
1374 Common Var(flag_dump_locations) Init(0)
1375 Dump detailed information on GCC's internal representation of source code locations.
1376
1377 fdump-passes
1378 Common Var(flag_dump_passes) Init(0)
1379 Dump optimization passes.
1380
1381 fdump-unnumbered
1382 Common Report Var(flag_dump_unnumbered)
1383 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1384
1385 fdump-unnumbered-links
1386 Common Report Var(flag_dump_unnumbered_links)
1387 Suppress output of previous and next insn numbers in debugging dumps.
1388
1389 fdwarf2-cfi-asm
1390 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1391 Enable CFI tables via GAS assembler directives.
1392
1393 fearly-inlining
1394 Common Report Var(flag_early_inlining) Init(1) Optimization
1395 Perform early inlining.
1396
1397 feliminate-dwarf2-dups
1398 Common Ignore
1399 Does nothing. Preserved for backward compatibility.
1400
1401 fipa-sra
1402 Common Report Var(flag_ipa_sra) Init(0) Optimization
1403 Perform interprocedural reduction of aggregates.
1404
1405 feliminate-unused-debug-symbols
1406 Common Report Var(flag_debug_only_used_symbols) Init(1)
1407 Perform unused symbol elimination in debug info.
1408
1409 feliminate-unused-debug-types
1410 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1411 Perform unused type elimination in debug info.
1412
1413 femit-class-debug-always
1414 Common Report Var(flag_emit_class_debug_always) Init(0)
1415 Do not suppress C++ class debug information.
1416
1417 fexceptions
1418 Common Report Var(flag_exceptions) Optimization
1419 Enable exception handling.
1420
1421 fexpensive-optimizations
1422 Common Report Var(flag_expensive_optimizations) Optimization
1423 Perform a number of minor, expensive optimizations.
1424
1425 fexcess-precision=
1426 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1427 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1428
1429 Enum
1430 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1431
1432 EnumValue
1433 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1434
1435 EnumValue
1436 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1437
1438 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1439 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1440 fpermitted-flt-eval-methods=
1441 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1442 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1443
1444 Enum
1445 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)
1446
1447 EnumValue
1448 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1449
1450 EnumValue
1451 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1452
1453 ffast-math
1454 Common Optimization
1455
1456 ffat-lto-objects
1457 Common Var(flag_fat_lto_objects)
1458 Output lto objects containing both the intermediate language and binary output.
1459
1460 ffinite-math-only
1461 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1462 Assume no NaNs or infinities are generated.
1463
1464 ffinite-loops
1465 Common Report Var(flag_finite_loops) Optimization
1466 Assume that loops with an exit will terminate and not loop indefinitely.
1467
1468 ffixed-
1469 Common Joined RejectNegative Var(common_deferred_options) Defer
1470 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1471
1472 ffloat-store
1473 Common Report Var(flag_float_store) Optimization
1474 Don't allocate floats and doubles in extended-precision registers.
1475
1476 fforce-addr
1477 Common Ignore
1478 Does nothing. Preserved for backward compatibility.
1479
1480 fforward-propagate
1481 Common Report Var(flag_forward_propagate) Optimization
1482 Perform a forward propagation pass on RTL.
1483
1484 ffp-contract=
1485 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1486 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1487
1488 Enum
1489 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1490
1491 EnumValue
1492 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1493
1494 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1495 EnumValue
1496 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1497
1498 EnumValue
1499 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1500
1501 ffp-int-builtin-inexact
1502 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1503 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1504
1505 ; Nonzero means don't put addresses of constant functions in registers.
1506 ; Used for compiling the Unix kernel, where strange substitutions are
1507 ; done on the assembly output.
1508 ffunction-cse
1509 Common Report Var(flag_no_function_cse,0) Optimization
1510 Allow function addresses to be held in registers.
1511
1512 ffunction-sections
1513 Common Report Var(flag_function_sections)
1514 Place each function into its own section.
1515
1516 fgcse
1517 Common Report Var(flag_gcse) Optimization
1518 Perform global common subexpression elimination.
1519
1520 fgcse-lm
1521 Common Report Var(flag_gcse_lm) Init(1) Optimization
1522 Perform enhanced load motion during global common subexpression elimination.
1523
1524 fgcse-sm
1525 Common Report Var(flag_gcse_sm) Init(0) Optimization
1526 Perform store motion after global common subexpression elimination.
1527
1528 fgcse-las
1529 Common Report Var(flag_gcse_las) Init(0) Optimization
1530 Perform redundant load after store elimination in global common subexpression
1531 elimination.
1532
1533 fgcse-after-reload
1534 Common Report Var(flag_gcse_after_reload) Optimization
1535 Perform global common subexpression elimination after register allocation has
1536 finished.
1537
1538 Enum
1539 Name(dwarf_gnat_encodings) Type(int)
1540
1541 EnumValue
1542 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1543
1544 EnumValue
1545 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1546
1547 EnumValue
1548 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1549
1550 fgnat-encodings=
1551 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1552 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1553
1554 ; This option is not documented yet as its semantics will change.
1555 fgraphite
1556 Common Report Var(flag_graphite) Optimization
1557 Enable in and out of Graphite representation.
1558
1559 fgraphite-identity
1560 Common Report Var(flag_graphite_identity) Optimization
1561 Enable Graphite Identity transformation.
1562
1563 fhoist-adjacent-loads
1564 Common Report Var(flag_hoist_adjacent_loads) Optimization
1565 Enable hoisting adjacent loads to encourage generating conditional move
1566 instructions.
1567
1568 fkeep-gc-roots-live
1569 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1570 ; Always keep a pointer to a live memory block
1571
1572 floop-parallelize-all
1573 Common Report Var(flag_loop_parallelize_all) Optimization
1574 Mark all loops as parallel.
1575
1576 floop-strip-mine
1577 Common Alias(floop-nest-optimize)
1578 Enable loop nest transforms. Same as -floop-nest-optimize.
1579
1580 floop-interchange
1581 Common Report Var(flag_loop_interchange) Optimization
1582 Enable loop interchange on trees.
1583
1584 floop-block
1585 Common Alias(floop-nest-optimize)
1586 Enable loop nest transforms. Same as -floop-nest-optimize.
1587
1588 floop-unroll-and-jam
1589 Common Report Var(flag_unroll_jam) Optimization
1590 Perform unroll-and-jam on loops.
1591
1592 fgnu-tm
1593 Common Report Var(flag_tm)
1594 Enable support for GNU transactional memory.
1595
1596 fgnu-unique
1597 Common Report Var(flag_gnu_unique) Init(1)
1598 Use STB_GNU_UNIQUE if supported by the assembler.
1599
1600 floop-flatten
1601 Common Ignore
1602 Does nothing. Preserved for backward compatibility.
1603
1604 floop-nest-optimize
1605 Common Report Var(flag_loop_nest_optimize) Optimization
1606 Enable the loop nest optimizer.
1607
1608 fstrict-volatile-bitfields
1609 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1610 Force bitfield accesses to match their type width.
1611
1612 fstore-merging
1613 Common Report Var(flag_store_merging) Optimization
1614 Merge adjacent stores.
1615
1616 fguess-branch-probability
1617 Common Report Var(flag_guess_branch_prob) Optimization
1618 Enable guessing of branch probabilities.
1619
1620 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1621 ; Generate position-independent code for executables if possible
1622 ; On SVR4 targets, it also controls whether or not to emit a
1623 ; string identifying the compiler.
1624 fident
1625 Common Report Var(flag_no_ident,0)
1626 Process #ident directives.
1627
1628 fif-conversion
1629 Common Report Var(flag_if_conversion) Optimization
1630 Perform conversion of conditional jumps to branchless equivalents.
1631
1632 fif-conversion2
1633 Common Report Var(flag_if_conversion2) Optimization
1634 Perform conversion of conditional jumps to conditional execution.
1635
1636 fstack-reuse=
1637 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1638 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1639
1640 Enum
1641 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1642
1643 EnumValue
1644 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1645
1646 EnumValue
1647 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1648
1649 EnumValue
1650 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1651
1652 ftree-loop-if-convert
1653 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1654 Convert conditional jumps in innermost loops to branchless equivalents.
1655
1656 ftree-loop-if-convert-stores
1657 Common Ignore
1658 Does nothing. Preserved for backward compatibility.
1659
1660 ; -finhibit-size-directive inhibits output of .size for ELF.
1661 ; This is used only for compiling crtstuff.c,
1662 ; and it may be extended to other effects
1663 ; needed for crtstuff.c on other systems.
1664 finhibit-size-directive
1665 Common Report Var(flag_inhibit_size_directive)
1666 Do not generate .size directives.
1667
1668 findirect-inlining
1669 Common Report Var(flag_indirect_inlining) Optimization
1670 Perform indirect inlining.
1671
1672 ; General flag to enable inlining. Specifying -fno-inline will disable
1673 ; all inlining apart from always-inline functions.
1674 finline
1675 Common Report Var(flag_no_inline,0) Init(0) Optimization
1676 Enable inlining of function declared \"inline\", disabling disables all inlining.
1677
1678 finline-small-functions
1679 Common Report Var(flag_inline_small_functions) Optimization
1680 Integrate functions into their callers when code size is known not to grow.
1681
1682 finline-functions
1683 Common Report Var(flag_inline_functions) Optimization
1684 Integrate functions not declared \"inline\" into their callers when profitable.
1685
1686 finline-functions-called-once
1687 Common Report Var(flag_inline_functions_called_once) Optimization
1688 Integrate functions only required by their single caller.
1689
1690 finline-limit-
1691 Common RejectNegative Joined Alias(finline-limit=)
1692
1693 finline-limit=
1694 Common RejectNegative Joined UInteger
1695 -finline-limit=<number> Limit the size of inlined functions to <number>.
1696
1697 finline-atomics
1698 Common Report Var(flag_inline_atomics) Init(1) Optimization
1699 Inline __atomic operations when a lock free instruction sequence is available.
1700
1701 fcf-protection
1702 Common RejectNegative Alias(fcf-protection=,full)
1703
1704 fcf-protection=
1705 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1706 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1707 instructions have valid targets.
1708
1709 Enum
1710 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1711
1712 EnumValue
1713 Enum(cf_protection_level) String(full) Value(CF_FULL)
1714
1715 EnumValue
1716 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1717
1718 EnumValue
1719 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1720
1721 EnumValue
1722 Enum(cf_protection_level) String(none) Value(CF_NONE)
1723
1724 finstrument-functions
1725 Common Report Var(flag_instrument_function_entry_exit)
1726 Instrument function entry and exit with profiling calls.
1727
1728 finstrument-functions-exclude-function-list=
1729 Common RejectNegative Joined
1730 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1731
1732 finstrument-functions-exclude-file-list=
1733 Common RejectNegative Joined
1734 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1735
1736 fipa-cp
1737 Common Report Var(flag_ipa_cp) Optimization
1738 Perform interprocedural constant propagation.
1739
1740 fipa-cp-clone
1741 Common Report Var(flag_ipa_cp_clone) Optimization
1742 Perform cloning to make Interprocedural constant propagation stronger.
1743
1744 fipa-cp-alignment
1745 Common Ignore
1746 Does nothing. Preserved for backward compatibility.
1747
1748 fipa-bit-cp
1749 Common Report Var(flag_ipa_bit_cp) Optimization
1750 Perform interprocedural bitwise constant propagation.
1751
1752 fipa-profile
1753 Common Report Var(flag_ipa_profile) Init(0) Optimization
1754 Perform interprocedural profile propagation.
1755
1756 fipa-pta
1757 Common Report Var(flag_ipa_pta) Init(0) Optimization
1758 Perform interprocedural points-to analysis.
1759
1760 fipa-pure-const
1761 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1762 Discover pure and const functions.
1763
1764 fipa-icf
1765 Common Report Var(flag_ipa_icf) Optimization
1766 Perform Identical Code Folding for functions and read-only variables.
1767
1768 fipa-icf-functions
1769 Common Report Var(flag_ipa_icf_functions) Optimization
1770 Perform Identical Code Folding for functions.
1771
1772 fipa-icf-variables
1773 Common Report Var(flag_ipa_icf_variables) Optimization
1774 Perform Identical Code Folding for variables.
1775
1776 fipa-reference
1777 Common Report Var(flag_ipa_reference) Init(0) Optimization
1778 Discover read-only and non addressable static variables.
1779
1780 fipa-reference-addressable
1781 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1782 Discover read-only, write-only and non-addressable static variables.
1783
1784 fipa-stack-alignment
1785 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1786 Reduce stack alignment on call sites if possible.
1787
1788 fipa-matrix-reorg
1789 Common Ignore
1790 Does nothing. Preserved for backward compatibility.
1791
1792 fipa-struct-reorg
1793 Common Ignore
1794 Does nothing. Preserved for backward compatibility.
1795
1796 fipa-vrp
1797 Common Report Var(flag_ipa_vrp) Optimization
1798 Perform IPA Value Range Propagation.
1799
1800 fira-algorithm=
1801 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1802 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1803
1804 Enum
1805 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1806
1807 EnumValue
1808 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1809
1810 EnumValue
1811 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1812
1813 fira-region=
1814 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1815 -fira-region=[one|all|mixed] Set regions for IRA.
1816
1817 Enum
1818 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1819
1820 EnumValue
1821 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1822
1823 EnumValue
1824 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1825
1826 EnumValue
1827 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1828
1829 fira-hoist-pressure
1830 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1831 Use IRA based register pressure calculation
1832 in RTL hoist optimizations.
1833
1834 fira-loop-pressure
1835 Common Report Var(flag_ira_loop_pressure) Optimization
1836 Use IRA based register pressure calculation
1837 in RTL loop optimizations.
1838
1839 fira-share-save-slots
1840 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1841 Share slots for saving different hard registers.
1842
1843 fira-share-spill-slots
1844 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1845 Share stack slots for spilled pseudo-registers.
1846
1847 fira-verbose=
1848 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1849 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1850
1851 fivopts
1852 Common Report Var(flag_ivopts) Init(1) Optimization
1853 Optimize induction variables on trees.
1854
1855 fjump-tables
1856 Common Var(flag_jump_tables) Init(1) Optimization
1857 Use jump tables for sufficiently large switch statements.
1858
1859 fkeep-inline-functions
1860 Common Report Var(flag_keep_inline_functions)
1861 Generate code for functions even if they are fully inlined.
1862
1863 fkeep-static-functions
1864 Common Report Var(flag_keep_static_functions)
1865 Generate code for static functions even if they are never called.
1866
1867 fkeep-static-consts
1868 Common Report Var(flag_keep_static_consts) Init(1)
1869 Emit static const variables even if they are not used.
1870
1871 fleading-underscore
1872 Common Report Var(flag_leading_underscore) Init(-1)
1873 Give external symbols a leading underscore.
1874
1875 floop-optimize
1876 Common Ignore
1877 Does nothing. Preserved for backward compatibility.
1878
1879 flra-remat
1880 Common Report Var(flag_lra_remat) Optimization
1881 Do CFG-sensitive rematerialization in LRA.
1882
1883 flto
1884 Common
1885 Enable link-time optimization.
1886
1887 flto=
1888 Common RejectNegative Joined Var(flag_lto)
1889 Link-time optimization with number of parallel jobs or jobserver.
1890
1891 Enum
1892 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1893
1894 EnumValue
1895 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1896
1897 EnumValue
1898 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1899
1900 EnumValue
1901 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1902
1903 EnumValue
1904 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1905
1906 EnumValue
1907 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1908
1909 flto-partition=
1910 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1911 Specify the algorithm to partition symbols and vars at linktime.
1912
1913 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1914 flto-compression-level=
1915 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
1916 -flto-compression-level=<number> Use zlib/zstd compression level <number> for IL.
1917
1918 flto-odr-type-merging
1919 Common Ignore
1920 Does nothing. Preserved for backward compatibility.
1921
1922 flto-report
1923 Common Report Var(flag_lto_report) Init(0)
1924 Report various link-time optimization statistics.
1925
1926 flto-report-wpa
1927 Common Report Var(flag_lto_report_wpa) Init(0)
1928 Report various link-time optimization statistics for WPA only.
1929
1930 fmath-errno
1931 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1932 Set errno after built-in math functions.
1933
1934 fmax-errors=
1935 Common Joined RejectNegative UInteger Var(flag_max_errors)
1936 -fmax-errors=<number> Maximum number of errors to report.
1937
1938 fmem-report
1939 Common Report Var(mem_report)
1940 Report on permanent memory allocation.
1941
1942 fmem-report-wpa
1943 Common Report Var(mem_report_wpa)
1944 Report on permanent memory allocation in WPA only.
1945
1946 ; This will attempt to merge constant section constants, if 1 only
1947 ; string constants and constants from constant pool, if 2 also constant
1948 ; variables.
1949 fmerge-all-constants
1950 Common Report Var(flag_merge_constants,2) Init(1)
1951 Attempt to merge identical constants and constant variables.
1952
1953 fmerge-constants
1954 Common Report Var(flag_merge_constants,1)
1955 Attempt to merge identical constants across compilation units.
1956
1957 fmerge-debug-strings
1958 Common Report Var(flag_merge_debug_strings) Init(1)
1959 Attempt to merge identical debug strings across compilation units.
1960
1961 fmessage-length=
1962 Common RejectNegative Joined UInteger
1963 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1964
1965 fmodulo-sched
1966 Common Report Var(flag_modulo_sched) Optimization
1967 Perform SMS based modulo scheduling before the first scheduling pass.
1968
1969 fmodulo-sched-allow-regmoves
1970 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1971 Perform SMS based modulo scheduling with register moves allowed.
1972
1973 fmove-loop-invariants
1974 Common Report Var(flag_move_loop_invariants) Optimization
1975 Move loop invariant computations out of loops.
1976
1977 fdce
1978 Common Var(flag_dce) Init(1) Optimization
1979 Use the RTL dead code elimination pass.
1980
1981 fdse
1982 Common Var(flag_dse) Init(0) Optimization
1983 Use the RTL dead store elimination pass.
1984
1985 freschedule-modulo-scheduled-loops
1986 Common Report Var(flag_resched_modulo_sched) Optimization
1987 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1988
1989 fnon-call-exceptions
1990 Common Report Var(flag_non_call_exceptions) Optimization
1991 Support synchronous non-call exceptions.
1992
1993 foffload=
1994 Common Driver Joined MissingArgError(options or targets missing after %qs)
1995 -foffload=<targets>=<options> Specify offloading targets and options for them.
1996
1997 foffload-abi=
1998 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1999 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2000
2001 Enum
2002 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2003
2004 EnumValue
2005 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2006
2007 EnumValue
2008 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2009
2010 fomit-frame-pointer
2011 Common Report Var(flag_omit_frame_pointer) Optimization
2012 When possible do not generate stack frames.
2013
2014 fopt-info
2015 Common Report Var(flag_opt_info) Optimization
2016 Enable all optimization info dumps on stderr.
2017
2018 fopt-info-
2019 Common Joined RejectNegative Var(common_deferred_options) Defer
2020 -fopt-info[-<type>=filename] Dump compiler optimization details.
2021
2022 fsave-optimization-record
2023 Common Report Var(flag_save_optimization_record) Optimization
2024 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2025
2026 foptimize-register-move
2027 Common Ignore
2028 Does nothing. Preserved for backward compatibility.
2029
2030 foptimize-sibling-calls
2031 Common Report Var(flag_optimize_sibling_calls) Optimization
2032 Optimize sibling and tail recursive calls.
2033
2034 fpartial-inlining
2035 Common Report Var(flag_partial_inlining) Optimization
2036 Perform partial inlining.
2037
2038 fpre-ipa-mem-report
2039 Common Report Var(pre_ipa_mem_report)
2040 Report on memory allocation before interprocedural optimization.
2041
2042 fpost-ipa-mem-report
2043 Common Report Var(post_ipa_mem_report)
2044 Report on memory allocation before interprocedural optimization.
2045
2046 fpack-struct
2047 Common Report Var(flag_pack_struct) Optimization
2048 Pack structure members together without holes.
2049
2050 fpack-struct=
2051 Common RejectNegative Joined UInteger Optimization
2052 -fpack-struct=<number> Set initial maximum structure member alignment.
2053
2054 fpcc-struct-return
2055 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2056 Return small aggregates in memory, not registers.
2057
2058 fpeel-loops
2059 Common Report Var(flag_peel_loops) Optimization
2060 Perform loop peeling.
2061
2062 fpeephole
2063 Common Report Var(flag_no_peephole,0) Optimization
2064 Enable machine specific peephole optimizations.
2065
2066 fpeephole2
2067 Common Report Var(flag_peephole2) Optimization
2068 Enable an RTL peephole pass before sched2.
2069
2070 fPIC
2071 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2072 Generate position-independent code if possible (large mode).
2073
2074 fPIE
2075 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2076 Generate position-independent code for executables if possible (large mode).
2077
2078 fpic
2079 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2080 Generate position-independent code if possible (small mode).
2081
2082 fpie
2083 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2084 Generate position-independent code for executables if possible (small mode).
2085
2086 fplt
2087 Common Report Var(flag_plt) Init(1) Optimization
2088 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2089
2090 fplugin=
2091 Common Joined RejectNegative Var(common_deferred_options) Defer
2092 Specify a plugin to load.
2093
2094 fplugin-arg-
2095 Common Joined RejectNegative Var(common_deferred_options) Defer
2096 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2097
2098 fpredictive-commoning
2099 Common Report Var(flag_predictive_commoning) Optimization
2100 Run predictive commoning optimization.
2101
2102 fprefetch-loop-arrays
2103 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2104 Generate prefetch instructions, if available, for arrays in loops.
2105
2106 fprofile
2107 Common Report Var(profile_flag)
2108 Enable basic program profiling code.
2109
2110 fprofile-abs-path
2111 Common Report Var(profile_abs_path_flag)
2112 Generate absolute source path names for gcov.
2113
2114 fprofile-arcs
2115 Common Report Var(profile_arc_flag)
2116 Insert arc-based program profiling code.
2117
2118 fprofile-dir=
2119 Common Joined RejectNegative Var(profile_data_prefix)
2120 Set the top-level directory for storing the profile data.
2121 The default is 'pwd'.
2122
2123 fprofile-note=
2124 Common Joined RejectNegative Var(profile_note_location)
2125 Select the name for storing the profile note file.
2126
2127 fprofile-correction
2128 Common Report Var(flag_profile_correction)
2129 Enable correction of flow inconsistent profile data input.
2130
2131 fprofile-update=
2132 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2133 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2134
2135 fprofile-filter-files=
2136 Common Joined RejectNegative Var(flag_profile_filter_files)
2137 Instrument only functions from files where names match any regular expression (separated by a semi-colon).
2138
2139 fprofile-exclude-files=
2140 Common Joined RejectNegative Var(flag_profile_exclude_files)
2141 Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon).
2142
2143 Enum
2144 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2145
2146 EnumValue
2147 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2148
2149 EnumValue
2150 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2151
2152 EnumValue
2153 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2154
2155 fprofile-generate
2156 Common
2157 Enable common options for generating profile info for profile feedback directed optimizations.
2158
2159 fprofile-generate=
2160 Common Joined RejectNegative
2161 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2162
2163 fprofile-use
2164 Common Var(flag_profile_use)
2165 Enable common options for performing profile feedback directed optimizations.
2166
2167 fprofile-use=
2168 Common Joined RejectNegative
2169 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2170
2171 fprofile-values
2172 Common Report Var(flag_profile_values)
2173 Insert code to profile values of expressions.
2174
2175 fprofile-report
2176 Common Report Var(profile_report)
2177 Report on consistency of profile.
2178
2179 fprofile-reorder-functions
2180 Common Report Var(flag_profile_reorder_functions)
2181 Enable function reordering that improves code placement.
2182
2183 fpatchable-function-entry=
2184 Common Joined Optimization
2185 Insert NOP instructions at each function entry.
2186
2187 frandom-seed
2188 Common Var(common_deferred_options) Defer
2189
2190 frandom-seed=
2191 Common Joined RejectNegative Var(common_deferred_options) Defer
2192 -frandom-seed=<string> Make compile reproducible using <string>.
2193
2194 ; This switch causes the command line that was used to create an
2195 ; object file to be recorded into the object file. The exact format
2196 ; of this recording is target and binary file format dependent.
2197 ; It is related to the -fverbose-asm switch, but that switch only
2198 ; records information in the assembler output file as comments, so
2199 ; they never reach the object file.
2200 frecord-gcc-switches
2201 Common Report Var(flag_record_gcc_switches)
2202 Record gcc command line switches in the object file.
2203
2204 freg-struct-return
2205 Common Report Var(flag_pcc_struct_return,0) Optimization
2206 Return small aggregates in registers.
2207
2208 fregmove
2209 Common Ignore
2210 Does nothing. Preserved for backward compatibility.
2211
2212 flifetime-dse
2213 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2214 Tell DSE that the storage for a C++ object is dead when the constructor
2215 starts and when the destructor finishes.
2216
2217 flifetime-dse=
2218 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2219
2220 flive-patching
2221 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2222
2223 flive-patching=
2224 Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2225 -flive-patching=[inline-only-static|inline-clone] Control IPA
2226 optimizations to provide a safe compilation for live-patching. At the same
2227 time, provides multiple-level control on the enabled IPA optimizations.
2228
2229 Enum
2230 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2231
2232 EnumValue
2233 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2234
2235 EnumValue
2236 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2237
2238 fallocation-dce
2239 Common Report Var(flag_allocation_dce) Init(1) Optimization
2240 Tell DCE to remove unused C++ allocations.
2241
2242 flive-range-shrinkage
2243 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2244 Relief of register pressure through live range shrinkage.
2245
2246 frename-registers
2247 Common Report Var(flag_rename_registers) Init(2) Optimization
2248 Perform a register renaming optimization pass.
2249
2250 fschedule-fusion
2251 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2252 Perform a target dependent instruction fusion optimization pass.
2253
2254 freorder-blocks
2255 Common Report Var(flag_reorder_blocks) Optimization
2256 Reorder basic blocks to improve code placement.
2257
2258 freorder-blocks-algorithm=
2259 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2260 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2261
2262 Enum
2263 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2264
2265 EnumValue
2266 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2267
2268 EnumValue
2269 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2270
2271 freorder-blocks-and-partition
2272 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2273 Reorder basic blocks and partition into hot and cold sections.
2274
2275 freorder-functions
2276 Common Report Var(flag_reorder_functions) Optimization
2277 Reorder functions to improve code placement.
2278
2279 frerun-cse-after-loop
2280 Common Report Var(flag_rerun_cse_after_loop) Optimization
2281 Add a common subexpression elimination pass after loop optimizations.
2282
2283 frerun-loop-opt
2284 Common Ignore
2285 Does nothing. Preserved for backward compatibility.
2286
2287 frounding-math
2288 Common Report Var(flag_rounding_math) Optimization SetByCombined
2289 Disable optimizations that assume default FP rounding behavior.
2290
2291 fsched-interblock
2292 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2293 Enable scheduling across basic blocks.
2294
2295 fsched-pressure
2296 Common Report Var(flag_sched_pressure) Init(0) Optimization
2297 Enable register pressure sensitive insn scheduling.
2298
2299 fsched-spec
2300 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2301 Allow speculative motion of non-loads.
2302
2303 fsched-spec-load
2304 Common Report Var(flag_schedule_speculative_load) Optimization
2305 Allow speculative motion of some loads.
2306
2307 fsched-spec-load-dangerous
2308 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2309 Allow speculative motion of more loads.
2310
2311 fsched-verbose=
2312 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2313 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2314
2315 fsched2-use-superblocks
2316 Common Report Var(flag_sched2_use_superblocks) Optimization
2317 If scheduling post reload, do superblock scheduling.
2318
2319 fsched2-use-traces
2320 Common Ignore
2321 Does nothing. Preserved for backward compatibility.
2322
2323 fschedule-insns
2324 Common Report Var(flag_schedule_insns) Optimization
2325 Reschedule instructions before register allocation.
2326
2327 fschedule-insns2
2328 Common Report Var(flag_schedule_insns_after_reload) Optimization
2329 Reschedule instructions after register allocation.
2330
2331 ; This flag should be on when a target implements non-trivial
2332 ; scheduling hooks, maybe saving some information for its own sake.
2333 ; On IA64, for example, this is used for correct bundling.
2334 fselective-scheduling
2335 Common Report Var(flag_selective_scheduling) Optimization
2336 Schedule instructions using selective scheduling algorithm.
2337
2338 fselective-scheduling2
2339 Common Report Var(flag_selective_scheduling2) Optimization
2340 Run selective scheduling after reload.
2341
2342 fself-test=
2343 Common Undocumented Joined Var(flag_self_test)
2344 Run self-tests, using the given path to locate test files.
2345
2346 fsel-sched-pipelining
2347 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2348 Perform software pipelining of inner loops during selective scheduling.
2349
2350 fsel-sched-pipelining-outer-loops
2351 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2352 Perform software pipelining of outer loops during selective scheduling.
2353
2354 fsel-sched-reschedule-pipelined
2355 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2356 Reschedule pipelined regions without pipelining.
2357
2358 fsemantic-interposition
2359 Common Report Var(flag_semantic_interposition) Init(1)
2360 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2361
2362 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2363 ; of stalled insns into the ready list.
2364 fsched-stalled-insns
2365 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2366 Allow premature scheduling of queued insns.
2367
2368 fsched-stalled-insns=
2369 Common RejectNegative Joined UInteger Optimization
2370 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2371
2372 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2373 ; be examined for a dependency on a stalled insn that is candidate for
2374 ; premature removal from the queue of stalled insns into the ready list (has
2375 ; an effect only if the flag 'sched_stalled_insns' is set).
2376 fsched-stalled-insns-dep
2377 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2378 Set dependence distance checking in premature scheduling of queued insns.
2379
2380 fsched-stalled-insns-dep=
2381 Common RejectNegative Joined UInteger Optimization
2382 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2383
2384 fsched-group-heuristic
2385 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2386 Enable the group heuristic in the scheduler.
2387
2388 fsched-critical-path-heuristic
2389 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2390 Enable the critical path heuristic in the scheduler.
2391
2392 fsched-spec-insn-heuristic
2393 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2394 Enable the speculative instruction heuristic in the scheduler.
2395
2396 fsched-rank-heuristic
2397 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2398 Enable the rank heuristic in the scheduler.
2399
2400 fsched-last-insn-heuristic
2401 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2402 Enable the last instruction heuristic in the scheduler.
2403
2404 fsched-dep-count-heuristic
2405 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2406 Enable the dependent count heuristic in the scheduler.
2407
2408 fsection-anchors
2409 Common Report Var(flag_section_anchors) Optimization
2410 Access data in the same section from shared anchor points.
2411
2412 fsee
2413 Common Ignore
2414 Does nothing. Preserved for backward compatibility.
2415
2416 fzee
2417 Common Ignore
2418 Does nothing. Preserved for backward compatibility.
2419
2420 free
2421 Common Report Var(flag_ree) Init(0)
2422 Turn on Redundant Extensions Elimination pass.
2423
2424 fshow-column
2425 Common Report Var(flag_show_column) Init(1)
2426 Show column numbers in diagnostics, when available. Default on.
2427
2428 fshrink-wrap
2429 Common Report Var(flag_shrink_wrap) Optimization
2430 Emit function prologues only before parts of the function that need it,
2431 rather than at the top of the function.
2432
2433 fshrink-wrap-separate
2434 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2435 Shrink-wrap parts of the prologue and epilogue separately.
2436
2437 fsignaling-nans
2438 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2439 Disable optimizations observable by IEEE signaling NaNs.
2440
2441 fsigned-zeros
2442 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2443 Disable floating point optimizations that ignore the IEEE signedness of zero.
2444
2445 fsingle-precision-constant
2446 Common Report Var(flag_single_precision_constant) Optimization
2447 Convert floating point constants to single precision constants.
2448
2449 fsplit-ivs-in-unroller
2450 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2451 Split lifetimes of induction variables when loops are unrolled.
2452
2453 fsplit-stack
2454 Common Report Var(flag_split_stack) Init(-1)
2455 Generate discontiguous stack frames.
2456
2457 fsplit-wide-types
2458 Common Report Var(flag_split_wide_types) Optimization
2459 Split wide types into independent registers.
2460
2461 fsplit-wide-types-early
2462 Common Report Var(flag_split_wide_types_early) Optimization
2463 Split wide types into independent registers earlier.
2464
2465 fssa-backprop
2466 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2467 Enable backward propagation of use properties at the SSA level.
2468
2469 fssa-phiopt
2470 Common Report Var(flag_ssa_phiopt) Optimization
2471 Optimize conditional patterns using SSA PHI nodes.
2472
2473 fstdarg-opt
2474 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2475 Optimize amount of stdarg registers saved to stack at start of function.
2476
2477 fvariable-expansion-in-unroller
2478 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2479 Apply variable expansion when loops are unrolled.
2480
2481 fstack-check=
2482 Common Report RejectNegative Joined Optimization
2483 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2484
2485 fstack-check
2486 Common Alias(fstack-check=, specific, no)
2487 Insert stack checking code into the program. Same as -fstack-check=specific.
2488
2489 fstack-clash-protection
2490 Common Report Var(flag_stack_clash_protection) Optimization
2491 Insert code to probe each page of stack space as it is allocated to protect
2492 from stack-clash style attacks.
2493
2494 fstack-limit
2495 Common Var(common_deferred_options) Defer
2496
2497 fstack-limit-register=
2498 Common RejectNegative Joined Var(common_deferred_options) Defer
2499 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2500
2501 fstack-limit-symbol=
2502 Common RejectNegative Joined Var(common_deferred_options) Defer
2503 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2504
2505 fstack-protector
2506 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2507 Use propolice as a stack protection method.
2508
2509 fstack-protector-all
2510 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2511 Use a stack protection method for every function.
2512
2513 fstack-protector-strong
2514 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2515 Use a smart stack protection method for certain functions.
2516
2517 fstack-protector-explicit
2518 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2519 Use stack protection method only for functions with the stack_protect attribute.
2520
2521 fstack-usage
2522 Common RejectNegative Var(flag_stack_usage)
2523 Output stack usage information on a per-function basis.
2524
2525 fstrength-reduce
2526 Common Ignore
2527 Does nothing. Preserved for backward compatibility.
2528
2529 ; Nonzero if we should do (language-dependent) alias analysis.
2530 ; Typically, this analysis will assume that expressions of certain
2531 ; types do not alias expressions of certain other types. Only used
2532 ; if alias analysis (in general) is enabled.
2533 fstrict-aliasing
2534 Common Report Var(flag_strict_aliasing) Optimization
2535 Assume strict aliasing rules apply.
2536
2537 fstrict-overflow
2538 Common Report
2539 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2540
2541 fsync-libcalls
2542 Common Report Var(flag_sync_libcalls) Init(1)
2543 Implement __atomic operations via libcalls to legacy __sync functions.
2544
2545 fsyntax-only
2546 Common Report Var(flag_syntax_only)
2547 Check for syntax errors, then stop.
2548
2549 ftest-coverage
2550 Common Report Var(flag_test_coverage)
2551 Create data files needed by \"gcov\".
2552
2553 fthread-jumps
2554 Common Report Var(flag_thread_jumps) Optimization
2555 Perform jump threading optimizations.
2556
2557 ftime-report
2558 Common Report Var(time_report)
2559 Report the time taken by each compiler pass.
2560
2561 ftime-report-details
2562 Common Report Var(time_report_details)
2563 Record times taken by sub-phases separately.
2564
2565 ftls-model=
2566 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2567 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2568
2569 Enum
2570 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2571
2572 EnumValue
2573 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2574
2575 EnumValue
2576 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2577
2578 EnumValue
2579 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2580
2581 EnumValue
2582 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2583
2584 ftoplevel-reorder
2585 Common Report Var(flag_toplevel_reorder) Init(2)
2586 Reorder top level functions, variables, and asms.
2587
2588 ftracer
2589 Common Report Var(flag_tracer) Optimization
2590 Perform superblock formation via tail duplication.
2591
2592 ftrampolines
2593 Common Report Var(flag_trampolines) Init(0)
2594 For targets that normally need trampolines for nested functions, always
2595 generate them instead of using descriptors.
2596
2597 ; Zero means that floating-point math operations cannot generate a
2598 ; (user-visible) trap. This is the case, for example, in nonstop
2599 ; IEEE 754 arithmetic.
2600 ftrapping-math
2601 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2602 Assume floating-point operations can trap.
2603
2604 ftrapv
2605 Common Report Var(flag_trapv) Optimization
2606 Trap for signed overflow in addition, subtraction and multiplication.
2607
2608 ftree-ccp
2609 Common Report Var(flag_tree_ccp) Optimization
2610 Enable SSA-CCP optimization on trees.
2611
2612 ftree-bit-ccp
2613 Common Report Var(flag_tree_bit_ccp) Optimization
2614 Enable SSA-BIT-CCP optimization on trees.
2615
2616 ftree-store-ccp
2617 Common Ignore
2618 Does nothing. Preserved for backward compatibility.
2619
2620 ftree-ch
2621 Common Report Var(flag_tree_ch) Optimization
2622 Enable loop header copying on trees.
2623
2624 ftree-coalesce-inlined-vars
2625 Common Ignore RejectNegative
2626 Does nothing. Preserved for backward compatibility.
2627
2628 ftree-coalesce-vars
2629 Common Report Var(flag_tree_coalesce_vars) Optimization
2630 Enable SSA coalescing of user variables.
2631
2632 ftree-copyrename
2633 Common Ignore
2634 Does nothing. Preserved for backward compatibility.
2635
2636 ftree-copy-prop
2637 Common Report Var(flag_tree_copy_prop) Optimization
2638 Enable copy propagation on trees.
2639
2640 ftree-store-copy-prop
2641 Common Ignore
2642 Does nothing. Preserved for backward compatibility.
2643
2644 ftree-cselim
2645 Common Report Var(flag_tree_cselim) Init(2) Optimization
2646 Transform condition stores into unconditional ones.
2647
2648 ftree-switch-conversion
2649 Common Report Var(flag_tree_switch_conversion) Optimization
2650 Perform conversions of switch initializations.
2651
2652 ftree-dce
2653 Common Report Var(flag_tree_dce) Optimization
2654 Enable SSA dead code elimination optimization on trees.
2655
2656 ftree-dominator-opts
2657 Common Report Var(flag_tree_dom) Optimization
2658 Enable dominator optimizations.
2659
2660 ftree-tail-merge
2661 Common Report Var(flag_tree_tail_merge) Optimization
2662 Enable tail merging on trees.
2663
2664 ftree-dse
2665 Common Report Var(flag_tree_dse) Optimization
2666 Enable dead store elimination.
2667
2668 ftree-forwprop
2669 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2670 Enable forward propagation on trees.
2671
2672 ftree-fre
2673 Common Report Var(flag_tree_fre) Optimization
2674 Enable Full Redundancy Elimination (FRE) on trees.
2675
2676 foptimize-strlen
2677 Common Report Var(flag_optimize_strlen) Optimization
2678 Enable string length optimizations on trees.
2679
2680 fisolate-erroneous-paths-dereference
2681 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2682 Detect paths that trigger erroneous or undefined behavior due to
2683 dereferencing a null pointer. Isolate those paths from the main control
2684 flow and turn the statement with erroneous or undefined behavior into a trap.
2685
2686 fisolate-erroneous-paths-attribute
2687 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2688 Detect paths that trigger erroneous or undefined behavior due to a null value
2689 being used in a way forbidden by a returns_nonnull or nonnull
2690 attribute. Isolate those paths from the main control flow and turn the
2691 statement with erroneous or undefined behavior into a trap.
2692
2693 ftree-loop-distribution
2694 Common Report Var(flag_tree_loop_distribution) Optimization
2695 Enable loop distribution on trees.
2696
2697 ftree-loop-distribute-patterns
2698 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2699 Enable loop distribution for patterns transformed into a library call.
2700
2701 ftree-loop-im
2702 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2703 Enable loop invariant motion on trees.
2704
2705 ftree-loop-linear
2706 Common Alias(floop-nest-optimize)
2707 Enable loop nest transforms. Same as -floop-nest-optimize.
2708
2709 ftree-loop-ivcanon
2710 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2711 Create canonical induction variables in loops.
2712
2713 ftree-loop-optimize
2714 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2715 Enable loop optimizations on tree level.
2716
2717 ftree-parallelize-loops=
2718 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2719 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2720
2721 ftree-phiprop
2722 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2723 Enable hoisting loads from conditional pointers.
2724
2725 ftree-pre
2726 Common Report Var(flag_tree_pre) Optimization
2727 Enable SSA-PRE optimization on trees.
2728
2729 ftree-partial-pre
2730 Common Report Var(flag_tree_partial_pre) Optimization
2731 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2732
2733 ftree-pta
2734 Common Report Var(flag_tree_pta) Optimization
2735 Perform function-local points-to analysis on trees.
2736
2737 ftree-reassoc
2738 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2739 Enable reassociation on tree level.
2740
2741 ftree-salias
2742 Common Ignore
2743 Does nothing. Preserved for backward compatibility.
2744
2745 ftree-sink
2746 Common Report Var(flag_tree_sink) Optimization
2747 Enable SSA code sinking on trees.
2748
2749 ftree-slsr
2750 Common Report Var(flag_tree_slsr) Optimization
2751 Perform straight-line strength reduction.
2752
2753 ftree-sra
2754 Common Report Var(flag_tree_sra) Optimization
2755 Perform scalar replacement of aggregates.
2756
2757 ftree-ter
2758 Common Report Var(flag_tree_ter) Optimization
2759 Replace temporary expressions in the SSA->normal pass.
2760
2761 ftree-lrs
2762 Common Report Var(flag_tree_live_range_split) Optimization
2763 Perform live range splitting during the SSA->normal pass.
2764
2765 ftree-vrp
2766 Common Report Var(flag_tree_vrp) Init(0) Optimization
2767 Perform Value Range Propagation on trees.
2768
2769 fsplit-paths
2770 Common Report Var(flag_split_paths) Init(0) Optimization
2771 Split paths leading to loop backedges.
2772
2773 funconstrained-commons
2774 Common Var(flag_unconstrained_commons) Optimization
2775 Assume common declarations may be overridden with ones with a larger
2776 trailing array.
2777
2778 funit-at-a-time
2779 Common Report Var(flag_unit_at_a_time) Init(1)
2780 Compile whole compilation unit at a time.
2781
2782 funroll-loops
2783 Common Report Var(flag_unroll_loops) Optimization
2784 Perform loop unrolling when iteration count is known.
2785
2786 funroll-all-loops
2787 Common Report Var(flag_unroll_all_loops) Optimization
2788 Perform loop unrolling for all loops.
2789
2790 ; Nonzero means that loop optimizer may assume that the induction variables
2791 ; that control loops do not overflow and that the loops with nontrivial
2792 ; exit condition are not infinite
2793 funsafe-loop-optimizations
2794 Common Ignore
2795 Does nothing. Preserved for backward compatibility.
2796
2797 fassociative-math
2798 Common Report Var(flag_associative_math) SetByCombined Optimization
2799 Allow optimization for floating-point arithmetic which may change the
2800 result of the operation due to rounding.
2801
2802 freciprocal-math
2803 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2804 Same as -fassociative-math for expressions which include division.
2805
2806 ; Nonzero means that unsafe floating-point math optimizations are allowed
2807 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2808 ; are allowed to assume that their arguments and results are "normal"
2809 ; (e.g., nonnegative for SQRT).
2810 funsafe-math-optimizations
2811 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2812 Allow math optimizations that may violate IEEE or ISO standards.
2813
2814 funswitch-loops
2815 Common Report Var(flag_unswitch_loops) Optimization
2816 Perform loop unswitching.
2817
2818 fsplit-loops
2819 Common Report Var(flag_split_loops) Optimization
2820 Perform loop splitting.
2821
2822 fversion-loops-for-strides
2823 Common Report Var(flag_version_loops_for_strides) Optimization
2824 Version loops based on whether indices have a stride of one.
2825
2826 funwind-tables
2827 Common Report Var(flag_unwind_tables) Optimization
2828 Just generate unwind tables for exception handling.
2829
2830 fuse-ld=bfd
2831 Common Driver Negative(fuse-ld=gold)
2832 Use the bfd linker instead of the default linker.
2833
2834 fuse-ld=gold
2835 Common Driver Negative(fuse-ld=bfd)
2836 Use the gold linker instead of the default linker.
2837
2838 fuse-ld=lld
2839 Common Driver Negative(fuse-ld=lld)
2840 Use the lld LLVM linker instead of the default linker.
2841
2842 fuse-linker-plugin
2843 Common Undocumented Var(flag_use_linker_plugin)
2844
2845 ; Positive if we should track variables, negative if we should run
2846 ; the var-tracking pass only to discard debug annotations, zero if
2847 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2848 ; will be set according to optimize, debug_info_level and debug_hooks
2849 ; in process_options ().
2850 fvar-tracking
2851 Common Report Var(flag_var_tracking) Init(2) PerFunction
2852 Perform variable tracking.
2853
2854 ; Positive if we should track variables at assignments, negative if
2855 ; we should run the var-tracking pass only to discard debug
2856 ; annotations. When flag_var_tracking_assignments ==
2857 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2858 fvar-tracking-assignments
2859 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2860 Perform variable tracking by annotating assignments.
2861
2862 ; Nonzero if we should toggle flag_var_tracking_assignments after
2863 ; processing options and computing its default. */
2864 fvar-tracking-assignments-toggle
2865 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2866 Toggle -fvar-tracking-assignments.
2867
2868 ; Positive if we should track uninitialized variables, negative if
2869 ; we should run the var-tracking pass only to discard debug
2870 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2871 ; will be set according to flag_var_tracking.
2872 fvar-tracking-uninit
2873 Common Report Var(flag_var_tracking_uninit) PerFunction
2874 Perform variable tracking and also tag variables that are uninitialized.
2875
2876 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2877 ftree-vectorize
2878 Common Report Optimization
2879 Enable vectorization on trees.
2880
2881 ftree-vectorizer-verbose=
2882 Common Joined RejectNegative Ignore
2883 Does nothing. Preserved for backward compatibility.
2884
2885 ftree-loop-vectorize
2886 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2887 Enable loop vectorization on trees.
2888
2889 ftree-slp-vectorize
2890 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2891 Enable basic block vectorization (SLP) on trees.
2892
2893 fvect-cost-model=
2894 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2895 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2896
2897 fsimd-cost-model=
2898 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2899 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2900
2901 Enum
2902 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2903
2904 EnumValue
2905 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2906
2907 EnumValue
2908 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2909
2910 EnumValue
2911 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2912
2913 fvect-cost-model
2914 Common Alias(fvect-cost-model=,dynamic,unlimited)
2915 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2916
2917 ftree-vect-loop-version
2918 Common Ignore
2919 Does nothing. Preserved for backward compatibility.
2920
2921 ftree-scev-cprop
2922 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2923 Enable copy propagation of scalar-evolution information.
2924
2925 ; -fverbose-asm causes extra commentary information to be produced in
2926 ; the generated assembly code (to make it more readable). This option
2927 ; is generally only of use to those who actually need to read the
2928 ; generated assembly code (perhaps while debugging the compiler itself).
2929 ; -fno-verbose-asm, the default, causes the extra information
2930 ; to not be added and is useful when comparing two assembler files.
2931 fverbose-asm
2932 Common Report Var(flag_verbose_asm)
2933 Add extra commentary to assembler output.
2934
2935 fvisibility=
2936 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2937 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2938
2939 Enum
2940 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2941
2942 EnumValue
2943 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2944
2945 EnumValue
2946 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2947
2948 EnumValue
2949 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2950
2951 EnumValue
2952 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2953
2954 fvtable-verify=
2955 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2956 Validate vtable pointers before using them.
2957
2958 Enum
2959 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2960
2961 EnumValue
2962 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2963
2964 EnumValue
2965 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2966
2967 EnumValue
2968 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2969
2970 fvtv-counts
2971 Common Var(flag_vtv_counts)
2972 Output vtable verification counters.
2973
2974 fvtv-debug
2975 Common Var(flag_vtv_debug)
2976 Output vtable verification pointer sets information.
2977
2978 fvpt
2979 Common Report Var(flag_value_profile_transformations) Optimization
2980 Use expression value profiles in optimizations.
2981
2982 fweb
2983 Common Report Var(flag_web) Init(2) Optimization
2984 Construct webs and split unrelated uses of single variable.
2985
2986 ftree-builtin-call-dce
2987 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2988 Enable conditional dead code elimination for builtin calls.
2989
2990 fwhole-program
2991 Common Report Var(flag_whole_program) Init(0)
2992 Perform whole program optimizations.
2993
2994 fwrapv-pointer
2995 Common Report Var(flag_wrapv_pointer) Optimization
2996 Assume pointer overflow wraps around.
2997
2998 fwrapv
2999 Common Report Var(flag_wrapv) Optimization
3000 Assume signed arithmetic overflow wraps around.
3001
3002 fzero-initialized-in-bss
3003 Common Report Var(flag_zero_initialized_in_bss) Init(1)
3004 Put zero initialized data in the bss section.
3005
3006 g
3007 Common Driver RejectNegative JoinedOrMissing
3008 Generate debug information in default format.
3009
3010 gas-loc-support
3011 Common Driver Var(dwarf2out_as_loc_support) Init(2)
3012 Assume assembler support for (DWARF2+) .loc directives.
3013
3014 gas-locview-support
3015 Common Driver Var(dwarf2out_as_locview_support) Init(2)
3016 Assume assembler support for view in (DWARF2+) .loc directives.
3017
3018 gcoff
3019 Common Driver WarnRemoved
3020 Does nothing. Preserved for backward compatibility.
3021
3022 gcoff1
3023 Common Driver WarnRemoved
3024 Does nothing. Preserved for backward compatibility.
3025
3026 gcoff2
3027 Common Driver WarnRemoved
3028 Does nothing. Preserved for backward compatibility.
3029
3030 gcoff3
3031 Common Driver WarnRemoved
3032 Does nothing. Preserved for backward compatibility.
3033
3034 gcolumn-info
3035 Common Driver Var(debug_column_info,1) Init(1)
3036 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3037
3038 gdwarf
3039 Common Driver JoinedOrMissing Negative(gdwarf-)
3040 Generate debug information in default version of DWARF format.
3041
3042 gdwarf-
3043 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
3044 Generate debug information in DWARF v2 (or later) format.
3045
3046 ggdb
3047 Common Driver JoinedOrMissing
3048 Generate debug information in default extended format.
3049
3050 ginline-points
3051 Common Driver Var(debug_inline_points) Init(2)
3052 Generate extended entry point information for inlined functions.
3053
3054 ginternal-reset-location-views
3055 Common Driver Var(debug_internal_reset_location_views) Init(2)
3056 Compute locview reset points based on insn length estimates.
3057
3058 gno-
3059 RejectNegative Joined Undocumented
3060 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3061
3062 gno-pubnames
3063 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3064 Don't generate DWARF pubnames and pubtypes sections.
3065
3066 gpubnames
3067 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3068 Generate DWARF pubnames and pubtypes sections.
3069
3070 ggnu-pubnames
3071 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3072 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3073
3074 grecord-gcc-switches
3075 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3076 Record gcc command line switches in DWARF DW_AT_producer.
3077
3078 gsplit-dwarf
3079 Common Driver Var(dwarf_split_debug_info) Init(0)
3080 Generate debug information in separate .dwo files.
3081
3082 gstabs
3083 Common Driver JoinedOrMissing Negative(gstabs+)
3084 Generate debug information in STABS format.
3085
3086 gstabs+
3087 Common Driver JoinedOrMissing Negative(gvms)
3088 Generate debug information in extended STABS format.
3089
3090 gstatement-frontiers
3091 Common Driver Var(debug_nonbind_markers_p) Init(2)
3092 Emit progressive recommended breakpoint locations.
3093
3094 gstrict-dwarf
3095 Common Driver Report Var(dwarf_strict) Init(0)
3096 Don't emit DWARF additions beyond selected version.
3097
3098 gdescribe-dies
3099 Common Driver Report Var(flag_describe_dies) Init(0)
3100 Add description attributes to some DWARF DIEs that have no name attribute.
3101
3102 gtoggle
3103 Common Driver Report Var(flag_gtoggle)
3104 Toggle debug information generation.
3105
3106 gvariable-location-views
3107 Common Driver Var(debug_variable_location_views, 1) Init(2)
3108 Augment variable location lists with progressive views.
3109
3110 gvariable-location-views=incompat5
3111 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3112
3113 gvms
3114 Common Driver JoinedOrMissing Negative(gxcoff)
3115 Generate debug information in VMS format.
3116
3117 gxcoff
3118 Common Driver JoinedOrMissing Negative(gxcoff+)
3119 Generate debug information in XCOFF format.
3120
3121 gxcoff+
3122 Common Driver JoinedOrMissing Negative(gdwarf)
3123 Generate debug information in extended XCOFF format.
3124
3125 Enum
3126 Name(compressed_debug_sections) Type(int)
3127
3128 ; Since -gz= is completely handled in specs, the values aren't used and we
3129 ; assign arbitrary constants.
3130 EnumValue
3131 Enum(compressed_debug_sections) String(none) Value(0)
3132
3133 EnumValue
3134 Enum(compressed_debug_sections) String(zlib) Value(1)
3135
3136 EnumValue
3137 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3138
3139 gz
3140 Common Driver
3141 Generate compressed debug sections.
3142
3143 gz=
3144 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3145 -gz=<format> Generate compressed debug sections in format <format>.
3146
3147 h
3148 Driver Joined Separate
3149
3150 iplugindir=
3151 Common Joined Var(plugindir_string) Init(0)
3152 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3153
3154 imultiarch
3155 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3156 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3157
3158 l
3159 Driver Joined Separate
3160
3161 n
3162 Driver
3163
3164 no-canonical-prefixes
3165 Driver
3166
3167 nodefaultlibs
3168 Driver
3169
3170 nostartfiles
3171 Driver
3172
3173 nolibc
3174 Driver
3175
3176 nostdlib
3177 Driver
3178
3179 o
3180 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3181 -o <file> Place output into <file>.
3182
3183 p
3184 Common Var(profile_flag)
3185 Enable function profiling.
3186
3187 pass-exit-codes
3188 Driver Var(pass_exit_codes)
3189
3190 pedantic
3191 Common Alias(Wpedantic)
3192
3193 pedantic-errors
3194 Common Var(flag_pedantic_errors)
3195 Like -pedantic but issue them as errors.
3196
3197 pg
3198 Driver
3199
3200 pipe
3201 Driver Var(use_pipes)
3202
3203 print-file-name=
3204 Driver JoinedOrMissing Var(print_file_name)
3205
3206 print-libgcc-file-name
3207 Driver
3208
3209 print-multi-directory
3210 Driver Var(print_multi_directory)
3211
3212 print-multi-lib
3213 Driver Var(print_multi_lib)
3214
3215 print-multi-os-directory
3216 Driver Var(print_multi_os_directory)
3217
3218 print-multiarch
3219 Driver Var(print_multiarch)
3220
3221 print-prog-name=
3222 Driver JoinedOrMissing Var(print_prog_name)
3223
3224 print-search-dirs
3225 Driver Var(print_search_dirs)
3226
3227 print-sysroot
3228 Driver Var(print_sysroot)
3229
3230 print-sysroot-headers-suffix
3231 Driver Var(print_sysroot_headers_suffix)
3232
3233 quiet
3234 Common Var(quiet_flag) RejectDriver
3235 Do not display functions compiled or elapsed time.
3236
3237 r
3238 Driver
3239
3240 s
3241 Driver
3242
3243 save-temps
3244 Driver
3245
3246 save-temps=
3247 Driver Joined
3248
3249 t
3250 Driver
3251
3252 time
3253 Driver Var(report_times)
3254
3255 time=
3256 Driver JoinedOrMissing
3257
3258 u
3259 Driver Joined Separate
3260
3261 undef
3262 Driver
3263 ; C option, but driver must not handle as "-u ndef".
3264
3265 v
3266 Common Driver Var(verbose_flag)
3267 Enable verbose output.
3268
3269 version
3270 Common Var(version_flag) RejectDriver
3271 Display the compiler's version.
3272
3273 w
3274 Common Var(inhibit_warnings)
3275 Suppress warnings.
3276
3277 wrapper
3278 Driver Separate Var(wrapper_string)
3279
3280 x
3281 Driver Joined Separate
3282
3283 shared
3284 Driver RejectNegative Negative(static-pie)
3285 Create a shared library.
3286
3287 shared-libgcc
3288 Driver
3289
3290 specs
3291 Driver Separate Alias(specs=)
3292
3293 specs=
3294 Driver Joined
3295
3296 static
3297 Driver
3298
3299 static-libgcc
3300 Driver
3301
3302 static-libgfortran
3303 Driver
3304 ; Documented for Fortran, but always accepted by driver.
3305
3306 static-libstdc++
3307 Driver
3308
3309 static-libgo
3310 Driver
3311 ; Documented for Go, but always accepted by driver.
3312
3313 static-libasan
3314 Driver
3315
3316 static-libtsan
3317 Driver
3318
3319 static-liblsan
3320 Driver
3321
3322 static-libubsan
3323 Driver
3324
3325 symbolic
3326 Driver
3327
3328 no-pie
3329 Driver RejectNegative Negative(shared)
3330 Don't create a dynamically linked position independent executable.
3331
3332 pie
3333 Driver RejectNegative Negative(no-pie)
3334 Create a dynamically linked position independent executable.
3335
3336 static-pie
3337 Driver RejectNegative Negative(pie)
3338 Create a static position independent executable.
3339
3340 z
3341 Driver Joined Separate
3342
3343 fipa-ra
3344 Common Report Var(flag_ipa_ra) Optimization
3345 Use caller save register across calls if possible.
3346
3347 ; This comment is to ensure we retain the blank line above.