tree-optimization/112450 - avoid AVX512 style masking for BImode masks
[official-gcc.git] / gcc / common.opt
blobd21db5d4a208d06eacef6488af285762cfefadc8
1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2023 Free Software Foundation, Inc.
5 ; This file is part of GCC.
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.
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.
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/>.
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
25 Variable
26 int target_flags
28 Variable
29 int optimize
31 Variable
32 int optimize_size
34 Variable
35 int optimize_debug
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
39 Variable
40 int optimize_fast
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
49 ; This variable is set to non-0 only by LTO front-end.  1 indicates that
50 ; the output produced will be used for incremental 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
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
62 Variable
63 int flag_default_complex_method = 1
65 ; Language specific warning pass for unused results.
66 Variable
67 bool flag_warn_unused_result = false
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
70 Variable
71 int flag_generate_lto
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
74 Variable
75 int flag_generate_offload = 0
77 ; Nonzero means we should be saving declaration info into a .X file.
78 Variable
79 int flag_gen_aux_info = 0
81 ; Nonzero if we are compiling code for a shared library, zero for
82 ; executable.
83 Variable
84 int flag_shlib
86 ; These three are really VEC(char_p,heap) *.
88 Variable
89 void *flag_instrument_functions_exclude_functions
91 Variable
92 void *flag_instrument_functions_exclude_files
94 Variable
95 void *flag_ignored_attributes
97 ; Generic structs (e.g. templates not explicitly specialized)
98 ; may not have a compilation unit associated with them, and so
99 ; may need to be treated differently from ordinary structs.
101 ; Structs only handled by reference (indirectly), will also usually
102 ; not need as much debugging information.
104 Variable
105 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
107 Variable
108 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
110 ; True if we should exit after parsing options.
111 Variable
112 bool exit_after_options
114 ; Type(s) of debugging information we are producing (if any).  See
115 ; flag-types.h for the definitions of the different possible types of
116 ; debugging information.
117 Variable
118 uint32_t write_symbols = NO_DEBUG
120 ; Level of debugging information we are producing.  See flag-types.h
121 ; for the definitions of the different possible levels.
122 Variable
123 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
125 ; Level of CTF debugging information we are producing.  See flag-types.h
126 ; for the definitions of the different possible levels.
127 Variable
128 enum ctf_debug_info_levels ctf_debug_info_level = CTFINFO_LEVEL_NONE
130 ; Original value of maximum field alignment in bytes, specified via
131 ; -fpack-struct=<value>.
132 Variable
133 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
135 ; Type of stack check.
136 Variable
137 enum stack_check_type flag_stack_check = NO_STACK_CHECK
139 ; True if stack usage information needs to be computed.
140 Variable
141 bool flag_stack_usage_info = false
143 ; -dA causes debug commentary information to be produced in
144 ; the generated assembly code (to make it more readable).  This option
145 ; is generally only of use to those who actually need to read the
146 ; generated assembly code (perhaps while debugging the compiler itself).
147 ; Currently, this switch is only used by dwarf2out.cc; however, it is intended
148 ; to be a catchall for printing debug information in the assembler file.
149 Variable
150 int flag_debug_asm
152 ; Balance between GNAT encodings and standard DWARF to emit.
153 Variable
154 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
156 ; -dP causes the rtl to be emitted as a comment in assembly.
157 Variable
158 int flag_dump_rtl_in_asm
160 ; Whether -da was passed (used only in handle_common_deferred_options).
161 Variable
162 bool flag_dump_all_passed
164 ; Other flags saying which kinds of debugging dump have been requested.
166 Variable
167 int rtl_dump_and_exit
169 Variable
170 int flag_print_asm_name
172 ; Name of top-level original source file (what was input to cpp).
173 ; This comes from the #-command at the beginning of the actual input.
174 ; If there isn't any there, then this is the cc1 input file name.
175 Variable
176 const char *main_input_filename
178 ; Pointer to base name in main_input_filename, with directories and a
179 ; single final extension removed, and the length of this base
180 ; name.
182 Variable
183 const char *main_input_basename
185 Variable
186 int main_input_baselength
188 ; The base name used for auxiliary output files.
189 ; dump_base_name minus dump_base_ext.
191 Variable
192 const char *aux_base_name
194 ; Which options have been printed by --help.
195 Variable
196 char *help_printed
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
204 ; The number of columns for --help output.
205 Variable
206 unsigned int help_columns
208 ; Whether this options structure has been through finish_options
209 Variable
210 bool flag_opts_finished
212 ; What the sanitizer should instrument
213 Variable
214 unsigned int flag_sanitize
216 ; What sanitizers should recover from errors
217 Variable
218 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS | SANITIZE_KERNEL_HWADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
220 ; What sanitizers should use __builtin_trap () instead of runtime diagnostics
221 Variable
222 unsigned int flag_sanitize_trap
224 ; Flag whether a prefix has been added to dump_base_name
225 Variable
226 bool dump_base_name_prefixed = false
228 ; What subset of registers should be zeroed on function return
229 Variable
230 unsigned int flag_zero_call_used_regs
233 Driver
235 -assemble
236 Driver Alias(S)
238 -compile
239 Driver Alias(c)
241 -completion=
242 Common Driver Joined Undocumented
243 Provide bash completion for options starting with provided string.
245 -coverage
246 Driver Alias(coverage)
248 -debug
249 Common Alias(g)
251 -dump
252 Common Separate Alias(d)
254 -dump=
255 Common Joined Alias(d)
257 -dumpbase
258 Driver Common Separate Alias(dumpbase)
260 -dumpbase-ext
261 Driver Common Separate Alias(dumpbase-ext)
263 -dumpdir
264 Driver Common Separate Alias(dumpdir)
266 -entry
267 Driver Separate Alias(e)
269 -entry=
270 Driver Joined Alias(e)
272 -extra-warnings
273 Common Warning Alias(Wextra)
275 -for-assembler
276 Driver Separate Alias(Xassembler)
278 -for-assembler=
279 Driver JoinedOrMissing Alias(Xassembler)
281 -for-linker
282 Driver Separate Alias(Xlinker)
284 -for-linker=
285 Driver JoinedOrMissing Alias(Xlinker)
287 -force-link
288 Driver Separate Alias(u)
290 -force-link=
291 Driver Joined Alias(u)
293 -help
294 Common Driver Var(help_flag)
295 Display this information.
297 -help=
298 Common Driver Joined
299 --help=<class>  Display descriptions of a specific class of options.  <class> is one or more of optimizers, target, warnings, undocumented, params.
301 -language
302 Driver Separate Alias(x)
304 -language=
305 Driver Joined Alias(x)
307 -library-directory
308 Driver Separate Alias(L)
310 -library-directory=
311 Driver Joined Alias(L)
313 -no-canonical-prefixes
314 Driver Alias(no-canonical-prefixes)
316 -no-standard-libraries
317 Driver Alias(nostdlib)
319 -no-sysroot-suffix
320 Driver Var(no_sysroot_suffix)
322 -no-warnings
323 Common Alias(w)
325 -optimize
326 Common Alias(O)
328 -output
329 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
331 -output=
332 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
334 -pass-exit-codes
335 Driver Alias(pass-exit-codes)
337 -pedantic
338 Common Alias(Wpedantic)
340 -pedantic-errors
341 Common Alias(pedantic-errors)
343 -pie
344 Driver Alias(pie)
346 -static-pie
347 Driver Alias(static-pie)
349 -pipe
350 Driver Alias(pipe)
352 -prefix
353 Driver Separate Alias(B)
355 -prefix=
356 Driver JoinedOrMissing Alias(B)
358 -preprocess
359 Driver Alias(E)
361 -print-file-name
362 Driver Separate Alias(print-file-name=)
364 -print-file-name=
365 Driver JoinedOrMissing Alias(print-file-name=)
367 -print-libgcc-file-name
368 Driver Alias(print-libgcc-file-name)
370 -print-multi-directory
371 Driver Alias(print-multi-directory)
373 -print-multi-lib
374 Driver Alias(print-multi-lib)
376 -print-multi-os-directory
377 Driver Alias(print-multi-os-directory)
379 -print-multiarch
380 Driver Alias(print-multiarch)
382 -print-prog-name
383 Driver Separate Alias(print-prog-name=)
385 -print-prog-name=
386 Driver JoinedOrMissing Alias(print-prog-name=)
388 -print-search-dirs
389 Driver Alias(print-search-dirs)
391 -print-sysroot
392 Driver Alias(print-sysroot)
394 -print-sysroot-headers-suffix
395 Driver Alias(print-sysroot-headers-suffix)
397 -profile
398 Common Alias(p)
400 -save-temps
401 Driver Alias(save-temps)
403 -shared
404 Driver Alias(shared)
406 -specs
407 Driver Separate Alias(specs=)
409 -specs=
410 Driver Joined Alias(specs=)
412 -static
413 Driver Alias(static)
415 -symbolic
416 Driver Alias(symbolic)
418 -target-help
419 Common Driver
420 Display target specific command line options (including assembler and linker options).
422 -time
423 Driver Alias(time)
425 -verbose
426 Driver Alias(v)
428 ;; The driver used to convert options such as --help into forms such
429 ;; as -fhelp; the following four entries are for compatibility with
430 ;; any direct uses of those (undocumented) -f forms
431 fhelp
432 Common Driver Alias(-help)
434 fhelp=
435 Common Driver Joined Alias(-help=)
437 ftarget-help
438 Common Driver Alias(-target-help)
440 fversion
441 Common Driver Alias(-version)
443 -sysroot
444 Driver Separate Alias(-sysroot=)
446 -sysroot=
447 Driver JoinedOrMissing
449 -version
450 Common Driver
453 Driver Joined Separate
456 Driver
459 Driver Joined Separate
462 Driver
465 Common JoinedOrMissing Optimization
466 -O<number>      Set optimization level to <number>.
469 Common Optimization
470 Optimize for space rather than speed.
472 Ofast
473 Common Optimization
474 Optimize for speed disregarding exact standards compliance.
477 Common Optimization
478 Optimize for debugging experience rather than speed or size.
481 Common Optimization
482 Optimize for space aggressively rather than speed.
485 Driver
488 Driver Negative(Qy)
491 Driver Negative(Qn)
494 Driver Joined Separate
497 Driver
500 Driver Joined Separate
502 Tbss
503 Driver Separate
505 Tbss=
506 Driver Joined
508 Tdata
509 Driver Separate
511 Tdata=
512 Driver Joined
514 Ttext
515 Driver Separate
517 Ttext=
518 Driver Joined
521 Common RejectNegative Warning Alias(Wextra)
522 This switch is deprecated; use -Wextra instead.
525 Driver JoinedOrMissing RejectNegative
528 Driver JoinedOrMissing RejectNegative
531 Driver JoinedOrMissing RejectNegative
533 Waggregate-return
534 Common Var(warn_aggregate_return) Warning
535 Warn about returning structures, unions or arrays.
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.
541 Warray-bounds
542 Common Alias(Warray-bounds=, 1, 0) Warning
544 Warray-bounds=
545 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
546 Warn if an array is accessed out of bounds.
548 Wuse-after-free
549 Common Var(warn_use_after_free) Warning
550 Warn for uses of pointers to deallocated storage.
552 Wuse-after-free=
553 Common Joined RejectNegative UInteger Var(warn_use_after_free) Warning IntegerRange(0, 3)
554 Warn for uses of pointers to deallocated storage.
556 Wattributes
557 Common Var(warn_attributes) Init(1) Warning
558 Warn about inappropriate attribute usage.
560 Wattributes=
561 Common Joined
562 Do not warn about specified attributes.
564 Wattribute-alias
565 Common Alias(Wattribute_alias=, 1, 0) Warning
566 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
568 Wattribute-alias=
569 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
570 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
572 Wcannot-profile
573 Common Var(warn_cannot_profile) Init(1) Warning
574 Warn when profiling instrumentation was requested, but could not be applied to
575 a certain function.
577 Wcast-align
578 Common Var(warn_cast_align) Warning
579 Warn about pointer casts which increase alignment.
581 Wcast-align=strict
582 Common Var(warn_cast_align,2) Warning
583 Warn about pointer casts which increase alignment.
585 Wcomplain-wrong-lang
586 Common Var(warn_complain_wrong_lang) Init(1) Warning
587 Complain when a command-line option is valid, but not applicable to the current front end.
589 Wcpp
590 Common Var(warn_cpp) Init(1) Warning
591 Warn when a #warning directive is encountered.
593 Wattribute-warning
594 Common Var(warn_attribute_warning) Init(1) Warning
595 Warn about uses of __attribute__((warning)) declarations.
597 Wdeprecated
598 Common Var(warn_deprecated) Init(1) Warning
599 Warn if a deprecated compiler feature, class, method, or field is used.
601 Wdeprecated-declarations
602 Common Var(warn_deprecated_decl) Init(1) Warning
603 Warn about uses of __attribute__((deprecated)) declarations.
605 Wdisabled-optimization
606 Common Var(warn_disabled_optimization) Warning
607 Warn when an optimization pass is disabled.
609 Werror
610 Common Var(warnings_are_errors)
611 Treat all warnings as errors.
613 Werror=
614 Common Joined
615 Treat specified warning as error.
617 Wextra
618 Common Var(extra_warnings) Warning
619 Print extra (possibly unwanted) warnings.
621 Wfatal-errors
622 Common Var(flag_fatal_errors)
623 Exit on the first error occurred.
625 Wframe-larger-than=
626 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
627 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
629 Wno-frame-larger-than
630 Common Alias(Wframe-larger-than=,18446744073709551615EiB,none) Warning
631 Disable -Wframe-larger-than= warning.  Equivalent to -Wframe-larger-than=<SIZE_MAX> or larger.
633 Wfree-nonheap-object
634 Common Var(warn_free_nonheap_object) Init(1) Warning
635 Warn when attempting to free a non-heap object.
637 Whsa
638 Common Ignore Warning
639 Does nothing.  Preserved for backward compatibility.
641 Wimplicit-fallthrough
642 Common Alias(Wimplicit-fallthrough=,3,0) Warning
644 Wimplicit-fallthrough=
645 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
646 Warn when a switch case falls through.
648 Winfinite-recursion
649 Var(warn_infinite_recursion) Warning
650 Warn for infinitely recursive calls.
652 Winline
653 Common Var(warn_inline) Warning Optimization
654 Warn when an inlined function cannot be inlined.
656 Winvalid-memory-model
657 Common Var(warn_invalid_memory_model) Init(1) Warning
658 Warn when an atomic memory model parameter is known to be outside the valid range.
660 Wlarger-than-
661 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
663 Wlarger-than=
664 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
665 -Wlarger-than=<byte-size>       Warn if an object's size exceeds <byte-size>.
667 Wno-larger-than
668 Common Alias(Wlarger-than=,18446744073709551615EiB,none) Warning
669 Disable -Wlarger-than= warning.  Equivalent to -Wlarger-than=<SIZE_MAX> or larger.
671 Wnonnull-compare
672 Var(warn_nonnull_compare) Warning
673 Warn if comparing pointer parameter with nonnull attribute with NULL.
675 Wnull-dereference
676 Common Var(warn_null_dereference) Warning
677 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
679 Wunsafe-loop-optimizations
680 Common Ignore Warning
681 Does nothing. Preserved for backward compatibility.
683 Wmissing-noreturn
684 Common Warning Alias(Wsuggest-attribute=noreturn)
686 Wodr
687 Common Var(warn_odr_violations) Init(1) Warning
688 Warn about some C++ One Definition Rule violations during link time optimization.
690 Woverflow
691 Common Var(warn_overflow) Init(1) Warning
692 Warn about overflow in arithmetic expressions.
694 Wlto-type-mismatch
695 Common Var(warn_lto_type_mismatch) Init(1) Warning
696 During link time optimization warn about mismatched types of global declarations.
698 Wpacked
699 Common Var(warn_packed) Warning
700 Warn when the packed attribute has no effect on struct layout.
702 Wpadded
703 Common Var(warn_padded) Warning
704 Warn when padding is required to align structure members.
706 Wpedantic
707 Common Var(pedantic) Init(0) Warning
708 Issue warnings needed for strict compliance to the standard.
710 Wreturn-local-addr
711 Common Var(warn_return_local_addr) Init(1) Warning
712 Warn about returning a pointer/reference to a local or temporary variable.
714 Wshadow
715 Common Var(warn_shadow) Warning
716 Warn when one variable shadows another.  Same as -Wshadow=global.
718 Wshadow=global
719 Common Warning Alias(Wshadow)
720 Warn when one variable shadows another (globally).
722 Wshadow=local
723 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
724 Warn when one local variable shadows another local variable or parameter.
726 Wshadow-local
727 Common Warning Undocumented Alias(Wshadow=local)
729 Wshadow=compatible-local
730 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
731 Warn when one local variable shadows another local variable or parameter of compatible type.
733 Wshadow-compatible-local
734 Common Warning Undocumented Alias(Wshadow=compatible-local)
736 Wstack-protector
737 Common Var(warn_stack_protect) Warning
738 Warn when not issuing stack smashing protection for some reason.
740 Wstack-usage=
741 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
742 -Wstack-usage=<byte-size>       Warn if stack usage might exceed <byte-size>.
744 Wno-stack-usage
745 Common Alias(Wstack-usage=,18446744073709551615EiB,none) Warning
746 Disable Wstack-usage= warning.  Equivalent to Wstack-usage=<SIZE_MAX> or larger.
748 Wstrict-aliasing
749 Common Warning
750 Warn about code which might break strict aliasing rules.
752 Wstrict-aliasing=
753 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
754 Warn about code which might break strict aliasing rules.
756 Wstrict-overflow
757 Common Warning
758 Warn about optimizations that assume that signed overflow is undefined.
760 Wstrict-overflow=
761 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
762 Warn about optimizations that assume that signed overflow is undefined.
764 Wsuggest-attribute=cold
765 Common Var(warn_suggest_attribute_cold) Warning
766 Warn about functions which might be candidates for __attribute__((cold)).
768 Wsuggest-attribute=const
769 Common Var(warn_suggest_attribute_const) Warning
770 Warn about functions which might be candidates for __attribute__((const)).
772 Wsuggest-attribute=pure
773 Common Var(warn_suggest_attribute_pure) Warning
774 Warn about functions which might be candidates for __attribute__((pure)).
776 Wsuggest-attribute=noreturn
777 Common Var(warn_suggest_attribute_noreturn) Warning
778 Warn about functions which might be candidates for __attribute__((noreturn)).
780 Wsuggest-attribute=malloc
781 Common Var(warn_suggest_attribute_malloc) Warning
782 Warn about functions which might be candidates for __attribute__((malloc)).
784 Wsuggest-final-types
785 Common Var(warn_suggest_final_types) Warning
786 Warn about C++ polymorphic types where adding final keyword would improve code quality.
788 Wsuggest-final-methods
789 Common Var(warn_suggest_final_methods) Warning
790 Warn about C++ virtual methods where adding final keyword would improve code quality.
792 Wswitch-unreachable
793 Common Var(warn_switch_unreachable) Warning Init(1)
794 Warn about statements between switch's controlling expression and the first
795 case.
797 Wsystem-headers
798 Common Var(warn_system_headers) Warning
799 Do not suppress warnings from system headers.
801 Wtrampolines
802 Common Var(warn_trampolines) Warning
803 Warn whenever a trampoline is generated.
805 Wtrivial-auto-var-init
806 Common Var(warn_trivial_auto_var_init) Warning Init(0)
807 Warn about cases where -ftrivial-auto-var-init cannot initialize an auto variable.
809 Wtype-limits
810 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
811 Warn if a comparison is always true or always false due to the limited range of the data type.
813 Wuninitialized
814 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
815 Warn about uninitialized automatic variables.
817 Wmaybe-uninitialized
818 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
819 Warn about maybe uninitialized automatic variables.
821 Wunreachable-code
822 Common Ignore Warning
823 Does nothing. Preserved for backward compatibility.
825 Wunused
826 Common Var(warn_unused) Init(0) Warning
827 Enable all -Wunused- warnings.
829 Wunused-but-set-parameter
830 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
831 Warn when a function parameter is only set, otherwise unused.
833 Wunused-but-set-variable
834 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
835 Warn when a variable is only set, otherwise unused.
837 Wunused-function
838 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
839 Warn when a function is unused.
841 Wunused-label
842 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
843 Warn when a label is unused.
845 Wunused-parameter
846 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
847 Warn when a function parameter is unused.
849 Wunused-value
850 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
851 Warn when an expression value is unused.
853 Wunused-variable
854 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
855 Warn when a variable is unused.
857 Wcoverage-mismatch
858 Common Var(warn_coverage_mismatch) Init(1) Warning
859 Warn in case profiles in -fprofile-use do not match.
861 Wcoverage-invalid-line-number
862 Common Var(warn_coverage_invalid_linenum) Init(1) Warning
863 Warn in case a function ends earlier than it begins due to an invalid linenum macros.
865 Wmissing-profile
866 Common Var(warn_missing_profile) Init(1) Warning
867 Warn in case profiles in -fprofile-use do not exist.
869 Wvector-operation-performance
870 Common Var(warn_vector_operation_performance) Warning
871 Warn when a vector operation is compiled outside the SIMD.
873 Wtsan
874 Common Var(warn_tsan) Init(1) Warning
875 Warn about unsupported features in ThreadSanitizer.
877 Xassembler
878 Driver Separate
880 Xlinker
881 Driver Separate
883 Xpreprocessor
884 Driver Separate
887 Driver
889 aux-info
890 Common Separate Var(aux_info_file_name)
891 -aux-info <file>        Emit declaration information into <file>.
893 aux-info=
894 Common Joined Alias(aux-info)
896 coverage
897 Driver
900 Driver
903 Common Joined
904 -d<letters>     Enable dumps from specific passes of the compiler.
906 dumpbase
907 Driver Common Separate Var(dump_base_name)
908 -dumpbase <file>        Set the file basename to be used for dumps.
910 dumpbase-ext
911 Driver Common Separate Var(dump_base_ext)
912 -dumpbase-ext .<ext>    Drop a trailing .<ext> from the dump basename to name auxiliary output files.
914 dumpdir
915 Driver Common Separate Var(dump_dir_name)
916 -dumpdir <dir>  Set the directory name to be used for dumps.
918 dumpmachine
919 Driver
921 dumpspecs
922 Driver
924 dumpversion
925 Driver
927 dumpfullversion
928 Driver
931 Driver Joined Separate
933 ; This option has historically been passed down to the linker by an
934 ; accident of a %{e*} spec, so ensure it continues to be passed down
935 ; as a single option.  The supported option for this purpose is
936 ; -rdynamic.  See PR 47390.
937 export-dynamic
938 Driver Undocumented
940 ; The version of the C++ ABI in use.  The following values are allowed:
942 ; 0: The version of the ABI believed most conformant with the C++ ABI
943 ;    specification.  This ABI may change as bugs are discovered and fixed.
944 ;    Therefore, 0 will not necessarily indicate the same ABI in different
945 ;    versions of G++.
947 ; 1: The version of the ABI first used in G++ 3.2.  No longer selectable.
949 ; 2: The version of the ABI first used in G++ 3.4, and the default
950 ;    until GCC 4.9.
952 ; 3: The version of the ABI that fixes the missing underscore
953 ;    in template non-type arguments of pointer type.
955 ; 4: The version of the ABI that introduces unambiguous mangling of
956 ;    vector types.  First selectable in G++ 4.5.
958 ; 5: The version of the ABI that ignores attribute const/noreturn
959 ;    in function pointer mangling, and corrects mangling of decltype and
960 ;    function parameters used in other parameters and the return type.
961 ;    First selectable in G++ 4.6.
963 ; 6: The version of the ABI that doesn't promote scoped enums to int and
964 ;    changes the mangling of template argument packs, const/static_cast,
965 ;    prefix ++ and --, and a class scope function used as a template
966 ;    argument.
967 ;    First selectable in G++ 4.7.
969 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
970 ;    corrects the mangling of lambdas in default argument scope.
971 ;    First selectable in G++ 4.8.
973 ; 8: The version of the ABI that corrects the substitution behavior of
974 ;    function types with function-cv-qualifiers.
975 ;    First selectable in G++ 4.9 and default in G++ 5.
977 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
978 ;    First selectable and default in G++ 5.2.
980 ; 10: The version of the ABI that mangles attributes that affect type
981 ;     identity, such as ia32 calling convention attributes (stdcall, etc.)
982 ;     Default in G++ 6 (set in c_common_post_options).
984 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
985 ;     and introduces new inheriting constructor handling.
986 ;     Default in G++ 7.
988 ; 12: Corrects the calling convention for classes with only deleted copy/move
989 ;     constructors and changes passing/returning of empty records.
990 ;     Default in G++ 8.1.
992 ; 13: Fixes the accidental change in 12 to the calling convention for classes
993 ;     with deleted copy constructor and trivial move constructor.
994 ;     Default in G++ 8.2.
996 ; 14: Corrects the mangling of nullptr expression.
997 ;     Default in G++ 10.
999 ; 15: Corrects G++ 10 ABI tag regression [PR98481].
1000 ;     Available, but not default, in G++ 10.3.
1002 ; 16: Changes the mangling of __alignof__ to be distinct from that of alignof.
1003 ;     Adds missing 'on' in mangling of operator names in some cases.
1004 ;     Default in G++ 11.
1006 ; 17: Fixes layout of classes that inherit from aggregate classes with default
1007 ;     member initializers in C++14 and up.
1008 ;     Default in G++ 12.
1010 ; 18: Corrects errors in mangling of lambdas with additional context.
1011 ;     Default in G++ 13.
1013 ; 19: Emits ABI tags if needed in structured binding mangled names.
1014 ;     Ignores cv-quals on [[no_unique_object]] members.
1015 ;     Default in G++ 14.
1017 ; Additional positive integers will be assigned as new versions of
1018 ; the ABI become the default version of the ABI.
1019 fabi-version=
1020 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1021 The version of the C++ ABI in use.
1023 faggressive-loop-optimizations
1024 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1025 Aggressively optimize loops using language constraints.
1027 falign-functions
1028 Common Var(flag_align_functions) Optimization
1029 Align the start of functions.
1031 falign-functions=
1032 Common RejectNegative Joined Var(str_align_functions) Optimization
1034 flimit-function-alignment
1035 Common Var(flag_limit_function_alignment) Optimization Init(0)
1037 falign-jumps
1038 Common Var(flag_align_jumps) Optimization
1039 Align labels which are only reached by jumping.
1041 falign-jumps=
1042 Common RejectNegative Joined Var(str_align_jumps) Optimization
1044 falign-labels
1045 Common Var(flag_align_labels) Optimization
1046 Align all labels.
1048 falign-labels=
1049 Common RejectNegative Joined Var(str_align_labels) Optimization
1051 falign-loops
1052 Common Var(flag_align_loops) Optimization
1053 Align the start of loops.
1055 falign-loops=
1056 Common RejectNegative Joined Var(str_align_loops) Optimization
1058 fallow-store-data-races
1059 Common Var(flag_store_data_races) Optimization
1060 Allow the compiler to introduce new data races on stores.
1062 fanalyzer
1063 Common Var(flag_analyzer)
1064 Enable static analysis pass.
1066 fargument-alias
1067 Common Ignore
1068 Does nothing. Preserved for backward compatibility.
1070 fargument-noalias
1071 Common Ignore
1072 Does nothing. Preserved for backward compatibility.
1074 fargument-noalias-global
1075 Common Ignore
1076 Does nothing. Preserved for backward compatibility.
1078 fargument-noalias-anything
1079 Common Ignore
1080 Does nothing. Preserved for backward compatibility.
1082 fsanitize=
1083 Common Driver Joined
1084 Select what to sanitize.
1086 fsanitize-coverage=
1087 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1088 Select type of coverage sanitization.
1090 Enum
1091 Name(sanitize_coverage) Type(int)
1093 EnumValue
1094 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1096 EnumValue
1097 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1099 fasan-shadow-offset=
1100 Common Joined RejectNegative Var(common_deferred_options) Defer
1101 -fasan-shadow-offset=<number>   Use custom shadow memory offset.
1103 fsanitize-sections=
1104 Common Joined RejectNegative Var(common_deferred_options) Defer
1105 -fsanitize-sections=<sec1,sec2,...>     Sanitize global variables
1106 in user-defined sections.
1108 fsanitize-recover=
1109 Common Joined
1110 After diagnosing undefined behavior attempt to continue execution.
1112 fsanitize-recover
1113 Common
1114 This switch is deprecated; use -fsanitize-recover= instead.
1116 fsanitize-trap=
1117 Common Driver Joined
1118 Use traps instead of diagnostics of undefined behavior sanitizers.
1120 fsanitize-trap
1121 Common Driver
1123 fsanitize-address-use-after-scope
1124 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1126 fsanitize-undefined-trap-on-error
1127 Common Driver Alias(fsanitize-trap)
1128 This switch is deprecated; use -fsanitize-trap= instead.
1130 fasynchronous-unwind-tables
1131 Common Var(flag_asynchronous_unwind_tables) Optimization
1132 Generate unwind tables that are exact at each instruction boundary.
1134 fauto-inc-dec
1135 Common Var(flag_auto_inc_dec) Init(1) Optimization
1136 Generate auto-inc/dec instructions.
1138 fauto-profile
1139 Common Var(flag_auto_profile)
1140 Use sample profile information for call graph node weights. The default
1141 profile file is fbdata.afdo in 'pwd'.
1143 fauto-profile=
1144 Common Joined RejectNegative Var(auto_profile_file)
1145 Use sample profile information for call graph node weights. The profile
1146 file is specified in the argument.
1148 ; -fcheck-bounds causes gcc to generate array bounds checks.
1149 ; For C, C++ and ObjC: defaults off.
1150 ; For Java: defaults to on.
1151 ; For Fortran: defaults to off.
1152 fbounds-check
1153 Common Var(flag_bounds_check)
1154 Generate code to check bounds before indexing arrays.
1156 fbranch-count-reg
1157 Common Var(flag_branch_on_count_reg) Optimization
1158 Replace add, compare, branch with branch on count register.
1160 fbranch-probabilities
1161 Common Var(flag_branch_probabilities) Optimization
1162 Use profiling information for branch probabilities.
1164 fbranch-target-load-optimize
1165 Common Ignore
1166 Does nothing.  Preserved for backward compatibility.
1168 fbranch-target-load-optimize2
1169 Common Ignore
1170 Does nothing.  Preserved for backward compatibility.
1172 fbtr-bb-exclusive
1173 Common Ignore
1174 Does nothing.  Preserved for backward compatibility.
1176 fcallgraph-info
1177 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1178 Output callgraph information on a per-file basis.
1180 fcallgraph-info=
1181 Common RejectNegative Joined
1182 Output callgraph information on a per-file basis with decorations.
1184 fcall-saved-
1185 Common Joined RejectNegative Var(common_deferred_options) Defer
1186 -fcall-saved-<register> Mark <register> as being preserved across functions.
1188 fcall-used-
1189 Common Joined RejectNegative Var(common_deferred_options) Defer
1190 -fcall-used-<register>  Mark <register> as being corrupted by function calls.
1192 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1193 ; be saved across function calls, if that produces overall better code.
1194 ; Optional now, so people can test it.
1195 fcaller-saves
1196 Common Var(flag_caller_saves) Optimization
1197 Save registers around function calls.
1199 fcheck-data-deps
1200 Common Ignore
1201 This switch is deprecated; do not use.
1203 fcheck-new
1204 Common Var(flag_check_new)
1205 Check the return value of new in C++.
1207 fchecking
1208 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1209 Perform internal consistency checkings.
1211 fchecking=
1212 Common Joined RejectNegative UInteger Var(flag_checking)
1213 Perform internal consistency checkings.
1215 fcanon-prefix-map
1216 Common Var(common_deferred_options) Defer
1217 For -f*-prefix-map= options compare canonicalized pathnames rather than just strings.
1219 fcode-hoisting
1220 Common Var(flag_code_hoisting) Optimization
1221 Enable code hoisting.
1223 fcombine-stack-adjustments
1224 Common Var(flag_combine_stack_adjustments) Optimization
1225 Looks for opportunities to reduce stack adjustments and stack references.
1227 fcommon
1228 Common Var(flag_no_common,0) Init(1)
1229 Put uninitialized globals in the common section.
1231 fcompare-debug
1232 Driver
1233 ; Converted by the driver to -fcompare-debug= options.
1235 fcompare-debug=
1236 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1237 -fcompare-debug[=<opts>]        Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1239 fcompare-debug-second
1240 Common Driver RejectNegative Var(flag_compare_debug)
1241 Run only the second compilation of -fcompare-debug.
1243 fcompare-elim
1244 Common Var(flag_compare_elim_after_reload) Optimization
1245 Perform comparison elimination after register allocation has finished.
1247 fconserve-stack
1248 Common Var(flag_conserve_stack) Optimization
1249 Do not perform optimizations increasing noticeably stack usage.
1251 fcprop-registers
1252 Common Var(flag_cprop_registers) Optimization
1253 Perform a register copy-propagation optimization pass.
1255 ffold-mem-offsets
1256 Target Bool Var(flag_fold_mem_offsets) Init(1)
1257 Fold instructions calculating memory offsets to the memory access instruction if possible.
1259 fcrossjumping
1260 Common Var(flag_crossjumping) Optimization
1261 Perform cross-jumping optimization.
1263 fcse-follow-jumps
1264 Common Var(flag_cse_follow_jumps) Optimization
1265 When running CSE, follow jumps to their targets.
1267 fcse-skip-blocks
1268 Common Ignore
1269 Does nothing.  Preserved for backward compatibility.
1271 fcx-limited-range
1272 Common Var(flag_cx_limited_range) Optimization SetByCombined
1273 Omit range reduction step when performing complex division.
1275 fcx-fortran-rules
1276 Common Var(flag_cx_fortran_rules) Optimization
1277 Complex multiplication and division follow Fortran rules.
1279 fdata-sections
1280 Common Var(flag_data_sections)
1281 Place data items into their own section.
1283 fdbg-cnt-list
1284 Common Var(flag_dbg_cnt_list)
1285 List all available debugging counters with their limits and counts.
1287 fdbg-cnt=
1288 Common RejectNegative Joined Var(common_deferred_options) Defer
1289 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1291 fdebug-prefix-map=
1292 Common Joined RejectNegative Var(common_deferred_options) Defer
1293 -fdebug-prefix-map=<old>=<new>  Map one directory name to another in debug information.
1295 ffile-prefix-map=
1296 Common Joined RejectNegative Var(common_deferred_options) Defer
1297 -ffile-prefix-map=<old>=<new>   Map one directory name to another in compilation result.
1299 fdebug-types-section
1300 Common Var(flag_debug_types_section) Init(0)
1301 Output .debug_types section when using DWARF v4 debuginfo.
1303 ; Nonzero for -fdefer-pop: don't pop args after each function call
1304 ; instead save them up to pop many calls' args with one insns.
1305 fdefer-pop
1306 Common Var(flag_defer_pop) Optimization
1307 Defer popping functions args from stack until later.
1309 fdelayed-branch
1310 Common Var(flag_delayed_branch) Optimization
1311 Attempt to fill delay slots of branch instructions.
1313 fdelete-dead-exceptions
1314 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1315 Delete dead instructions that may throw exceptions.
1317 fdelete-null-pointer-checks
1318 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1319 Delete useless null pointer checks.
1321 fdevirtualize-at-ltrans
1322 Common Var(flag_ltrans_devirtualize)
1323 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1325 fdevirtualize-speculatively
1326 Common Var(flag_devirtualize_speculatively) Optimization
1327 Perform speculative devirtualization.
1329 fdevirtualize
1330 Common Var(flag_devirtualize) Optimization
1331 Try to convert virtual calls to direct ones.
1333 fdiagnostics-show-location=
1334 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1335 -fdiagnostics-show-location=[once|every-line]   How often to emit source location at the beginning of line-wrapped diagnostics.
1337 ; Required for these enum values.
1338 SourceInclude
1339 pretty-print.h
1341 Enum
1342 Name(diagnostic_prefixing_rule) Type(int)
1344 EnumValue
1345 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1347 EnumValue
1348 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1350 fdiagnostics-show-caret
1351 Common Var(flag_diagnostics_show_caret) Init(1)
1352 Show the source line with a caret indicating the column.
1354 fdiagnostics-show-labels
1355 Common Var(flag_diagnostics_show_labels) Init(1)
1356 Show labels annotating ranges of source code when showing source.
1358 fdiagnostics-show-line-numbers
1359 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1360 Show line numbers in the left margin when showing source.
1362 fdiagnostics-color
1363 Common Alias(fdiagnostics-color=,always,never)
1366 fdiagnostics-color=
1367 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1368 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1370 ; Required for these enum values.
1371 SourceInclude
1372 diagnostic-color.h
1374 Enum
1375 Name(diagnostic_color_rule) Type(int)
1377 EnumValue
1378 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1380 EnumValue
1381 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1383 EnumValue
1384 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1386 fdiagnostics-urls=
1387 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1388 -fdiagnostics-urls=[never|always|auto]  Embed URLs in diagnostics.
1390 ; Required for these enum values.
1391 SourceInclude
1392 diagnostic-url.h
1394 Enum
1395 Name(diagnostic_url_rule) Type(int)
1397 EnumValue
1398 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1400 EnumValue
1401 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1403 EnumValue
1404 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1406 fdiagnostics-column-unit=
1407 Common Joined RejectNegative Enum(diagnostics_column_unit)
1408 -fdiagnostics-column-unit=[display|byte]        Select whether column numbers are output as display columns (default) or raw bytes.
1410 fdiagnostics-column-origin=
1411 Common Joined RejectNegative UInteger
1412 -fdiagnostics-column-origin=<number>    Set the number of the first column.  The default is 1-based as per GNU style, but some utilities may expect 0-based, for example.
1414 fdiagnostics-format=
1415 Common Joined RejectNegative Enum(diagnostics_output_format)
1416 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file]  Select output format.
1418 fdiagnostics-escape-format=
1419 Common Joined RejectNegative Enum(diagnostics_escape_format)
1420 -fdiagnostics-escape-format=[unicode|bytes]     Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1422 ; Required for these enum values.
1423 SourceInclude
1424 diagnostic.h
1426 Enum
1427 Name(diagnostics_column_unit) Type(int)
1429 EnumValue
1430 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1432 EnumValue
1433 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1435 Enum
1436 Name(diagnostics_escape_format) Type(int)
1438 EnumValue
1439 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1441 EnumValue
1442 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1444 Enum
1445 Name(diagnostics_output_format) Type(int)
1447 EnumValue
1448 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1450 EnumValue
1451 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1453 EnumValue
1454 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1456 EnumValue
1457 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1459 EnumValue
1460 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1462 EnumValue
1463 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1465 fdiagnostics-parseable-fixits
1466 Common Var(flag_diagnostics_parseable_fixits)
1467 Print fix-it hints in machine-readable form.
1469 fdiagnostics-generate-patch
1470 Common Var(flag_diagnostics_generate_patch)
1471 Print fix-it hints to stderr in unified diff format.
1473 fdiagnostics-show-option
1474 Common Var(flag_diagnostics_show_option) Init(1)
1475 Amend appropriate diagnostic messages with the command line option that controls them.
1477 fdiagnostics-show-cwe
1478 Common Var(flag_diagnostics_show_cwe) Init(1)
1479 Print CWE identifiers for diagnostic messages, where available.
1481 fdiagnostics-show-rules
1482 Common Var(flag_diagnostics_show_rules) Init(1)
1483 Print any rules associated with diagnostic messages.
1485 fdiagnostics-path-format=
1486 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1487 Specify how to print any control-flow path associated with a diagnostic.
1489 fdiagnostics-plain-output
1490 Driver Common RejectNegative
1491 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1493 ftabstop=
1494 Common Joined RejectNegative UInteger
1495 -ftabstop=<number>      Distance between tab stops for column reporting.
1497 Enum
1498 Name(diagnostic_path_format) Type(int)
1500 EnumValue
1501 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1503 EnumValue
1504 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1506 EnumValue
1507 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1509 fdiagnostics-show-path-depths
1510 Common Var(flag_diagnostics_show_path_depths) Init(0)
1511 Show stack depths of events in paths.
1513 fdiagnostics-text-art-charset=
1514 Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1515 -fdiagnostics-text-art-charset=[none|ascii|unicode|emoji]       Determine which characters to use in text arg diagrams.
1517 Enum
1518 Name(diagnostic_text_art_charset) Type(int)
1520 EnumValue
1521 Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
1523 EnumValue
1524 Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
1526 EnumValue
1527 Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
1529 EnumValue
1530 Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1532 fdiagnostics-minimum-margin-width=
1533 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1534 Set minimum width of left margin of source code when showing source.
1536 fdisable-
1537 Common Joined RejectNegative Var(common_deferred_options) Defer
1538 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2   Disable an optimization pass.
1540 fenable-
1541 Common Joined RejectNegative Var(common_deferred_options) Defer
1542 -fenable-[tree|rtl|ipa]-<pass>=range1+range2    Enable an optimization pass.
1544 fdump-
1545 Common Joined RejectNegative Var(common_deferred_options) Defer
1546 -fdump-<type>   Dump various compiler internals to a file.
1548 fdump-final-insns
1549 Driver RejectNegative
1551 fdump-final-insns=
1552 Common RejectNegative Joined Var(flag_dump_final_insns)
1553 -fdump-final-insns=filename     Dump to filename the insns at the end of translation.
1555 fdump-go-spec=
1556 Common RejectNegative Joined Var(flag_dump_go_spec)
1557 -fdump-go-spec=filename Write all declarations to file as Go code.
1559 fdump-noaddr
1560 Common Var(flag_dump_noaddr)
1561 Suppress output of addresses in debugging dumps.
1563 freport-bug
1564 Common Driver Var(flag_report_bug)
1565 Collect and dump debug information into temporary file if ICE in C/C++
1566 compiler occurred.
1568 fdump-internal-locations
1569 Common Var(flag_dump_locations) Init(0)
1570 Dump detailed information on GCC's internal representation of source code locations.
1572 fdump-passes
1573 Common Var(flag_dump_passes) Init(0)
1574 Dump optimization passes.
1576 fdump-unnumbered
1577 Common Var(flag_dump_unnumbered)
1578 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1580 fdump-unnumbered-links
1581 Common Var(flag_dump_unnumbered_links)
1582 Suppress output of previous and next insn numbers in debugging dumps.
1584 fdwarf2-cfi-asm
1585 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1586 Enable CFI tables via GAS assembler directives.
1588 fearly-inlining
1589 Common Var(flag_early_inlining) Init(1) Optimization
1590 Perform early inlining.
1592 feliminate-dwarf2-dups
1593 Common Ignore
1594 Does nothing.  Preserved for backward compatibility.
1596 fipa-sra
1597 Common Var(flag_ipa_sra) Init(0) Optimization
1598 Perform interprocedural reduction of aggregates.
1600 feliminate-unused-debug-symbols
1601 Common Var(flag_debug_only_used_symbols) Init(1)
1602 Perform unused symbol elimination in debug info.
1604 feliminate-unused-debug-types
1605 Common Var(flag_eliminate_unused_debug_types) Init(1)
1606 Perform unused type elimination in debug info.
1608 femit-class-debug-always
1609 Common Var(flag_emit_class_debug_always) Init(0)
1610 Do not suppress C++ class debug information.
1612 fexceptions
1613 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1614 Enable exception handling.
1616 fexpensive-optimizations
1617 Common Var(flag_expensive_optimizations) Optimization
1618 Perform a number of minor, expensive optimizations.
1620 fexcess-precision=
1621 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1622 -fexcess-precision=[fast|standard|16]   Specify handling of excess floating-point precision.
1624 Enum
1625 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1627 EnumValue
1628 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1630 EnumValue
1631 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1633 EnumValue
1634 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1636 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1637 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1638 fpermitted-flt-eval-methods=
1639 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1640 -fpermitted-flt-eval-methods=[c11|ts-18661]     Specify which values of FLT_EVAL_METHOD are permitted.
1642 Enum
1643 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)
1645 EnumValue
1646 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1648 EnumValue
1649 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1651 ffast-math
1652 Common Optimization
1654 ffat-lto-objects
1655 Common Var(flag_fat_lto_objects)
1656 Output lto objects containing both the intermediate language and binary output.
1658 ffinite-math-only
1659 Common Var(flag_finite_math_only) Optimization SetByCombined
1660 Assume no NaNs or infinities are generated.
1662 ffinite-loops
1663 Common Var(flag_finite_loops) Optimization Init(0)
1664 Assume that loops with an exit will terminate and not loop indefinitely.
1666 ffixed-
1667 Common Joined RejectNegative Var(common_deferred_options) Defer
1668 -ffixed-<register>      Mark <register> as being unavailable to the compiler.
1670 ffloat-store
1671 Common Var(flag_float_store) Optimization
1672 Don't allocate floats and doubles in extended-precision registers.
1674 fforce-addr
1675 Common Ignore
1676 Does nothing.  Preserved for backward compatibility.
1678 fforward-propagate
1679 Common Var(flag_forward_propagate) Optimization
1680 Perform a forward propagation pass on RTL.
1682 ffp-contract=
1683 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1684 -ffp-contract=[off|on|fast]     Perform floating-point expression contraction.
1686 Enum
1687 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1689 EnumValue
1690 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1692 EnumValue
1693 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_ON)
1695 EnumValue
1696 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1698 ffp-int-builtin-inexact
1699 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1700 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1702 ; Nonzero means don't put addresses of constant functions in registers.
1703 ; Used for compiling the Unix kernel, where strange substitutions are
1704 ; done on the assembly output.
1705 ffunction-cse
1706 Common Var(flag_no_function_cse,0) Optimization
1707 Allow function addresses to be held in registers.
1709 ffunction-sections
1710 Common Var(flag_function_sections)
1711 Place each function into its own section.
1713 fgcse
1714 Common Var(flag_gcse) Optimization
1715 Perform global common subexpression elimination.
1717 fgcse-lm
1718 Common Var(flag_gcse_lm) Init(1) Optimization
1719 Perform enhanced load motion during global common subexpression elimination.
1721 fgcse-sm
1722 Common Var(flag_gcse_sm) Init(0) Optimization
1723 Perform store motion after global common subexpression elimination.
1725 fgcse-las
1726 Common Var(flag_gcse_las) Init(0) Optimization
1727 Perform redundant load after store elimination in global common subexpression
1728 elimination.
1730 fgcse-after-reload
1731 Common Var(flag_gcse_after_reload) Optimization
1732 Perform global common subexpression elimination after register allocation has
1733 finished.
1735 Enum
1736 Name(dwarf_gnat_encodings) Type(int)
1738 EnumValue
1739 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1741 EnumValue
1742 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1744 EnumValue
1745 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1747 fgnat-encodings=
1748 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1749 -fgnat-encodings=[all|gdb|minimal]      Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1751 ; This option is not documented yet as its semantics will change.
1752 fgraphite
1753 Common Var(flag_graphite) Optimization
1754 Enable in and out of Graphite representation.
1756 fgraphite-identity
1757 Common Var(flag_graphite_identity) Optimization
1758 Enable Graphite Identity transformation.
1760 fhoist-adjacent-loads
1761 Common Var(flag_hoist_adjacent_loads) Optimization
1762 Enable hoisting adjacent loads to encourage generating conditional move
1763 instructions.
1765 fkeep-gc-roots-live
1766 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1767 ; Always keep a pointer to a live memory block
1769 flarge-source-files
1770 Common Var(flag_large_source_files) Init(0)
1771 Improve GCC's ability to track column numbers in large source files,
1772 at the expense of slower compilation.
1774 floop-parallelize-all
1775 Common Var(flag_loop_parallelize_all) Optimization
1776 Mark all loops as parallel.
1778 floop-strip-mine
1779 Common Alias(floop-nest-optimize)
1780 Enable loop nest transforms.  Same as -floop-nest-optimize.
1782 floop-interchange
1783 Common Var(flag_loop_interchange) Optimization
1784 Enable loop interchange on trees.
1786 floop-block
1787 Common Alias(floop-nest-optimize)
1788 Enable loop nest transforms.  Same as -floop-nest-optimize.
1790 floop-unroll-and-jam
1791 Common Var(flag_unroll_jam) Optimization
1792 Perform unroll-and-jam on loops.
1794 fgnu-tm
1795 Common Var(flag_tm)
1796 Enable support for GNU transactional memory.
1798 fgnu-unique
1799 Common Var(flag_gnu_unique) Init(1)
1800 Use STB_GNU_UNIQUE if supported by the assembler.
1802 floop-flatten
1803 Common Ignore
1804 Does nothing. Preserved for backward compatibility.
1806 floop-nest-optimize
1807 Common Var(flag_loop_nest_optimize) Optimization
1808 Enable the loop nest optimizer.
1810 fstrict-volatile-bitfields
1811 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1812 Force bitfield accesses to match their type width.
1814 fstore-merging
1815 Common Var(flag_store_merging) Optimization
1816 Merge adjacent stores.
1818 fguess-branch-probability
1819 Common Var(flag_guess_branch_prob) Optimization
1820 Enable guessing of branch probabilities.
1822 fharden-compares
1823 Common Var(flag_harden_compares) Optimization
1824 Harden conditionals not used in branches, checking reversed conditions.
1826 fharden-conditional-branches
1827 Common Var(flag_harden_conditional_branches) Optimization
1828 Harden conditional branches by checking reversed conditions.
1830 fharden-control-flow-redundancy
1831 Common Var(flag_harden_control_flow_redundancy) Optimization
1832 Harden control flow by recording and checking execution paths.
1834 fhardcfr-skip-leaf
1835 Common Var(flag_harden_control_flow_redundancy_skip_leaf) Optimization
1836 Disable CFR in leaf functions.
1838 fhardcfr-check-returning-calls
1839 Common Var(flag_harden_control_flow_redundancy_check_returning_calls) Init(-1) Optimization
1840 Check CFR execution paths also before calls followed by returns of their results.
1842 fhardcfr-check-exceptions
1843 Common Var(flag_harden_control_flow_redundancy_check_exceptions) Init(-1) Optimization
1844 Check CFR execution paths also when exiting a function through an exception.
1846 fhardcfr-check-noreturn-calls=
1847 Common Joined RejectNegative Enum(hardcfr_check_noreturn_calls) Var(flag_harden_control_flow_redundancy_check_noreturn) Init(HCFRNR_UNSPECIFIED) Optimization
1848 -fhardcfr-check-noreturn-calls=[always|no-xthrow|nothrow|never] Check CFR execution paths also before calling noreturn functions.
1850 Enum
1851 Name(hardcfr_check_noreturn_calls) Type(enum hardcfr_noret) UnknownError(unknown hardcfr noreturn checking level %qs)
1853 EnumValue
1854 Enum(hardcfr_check_noreturn_calls) String(never) Value(HCFRNR_NEVER)
1856 EnumValue
1857 Enum(hardcfr_check_noreturn_calls) String(nothrow) Value(HCFRNR_NOTHROW)
1859 EnumValue
1860 Enum(hardcfr_check_noreturn_calls) String(no-xthrow) Value(HCFRNR_NO_XTHROW)
1862 EnumValue
1863 Enum(hardcfr_check_noreturn_calls) String(always) Value(HCFRNR_ALWAYS)
1865 ; Nonzero means ignore `#ident' directives.  0 means handle them.
1866 ; Generate position-independent code for executables if possible
1867 ; On SVR4 targets, it also controls whether or not to emit a
1868 ; string identifying the compiler.
1869 fident
1870 Common Var(flag_no_ident,0)
1871 Process #ident directives.
1873 fif-conversion
1874 Common Var(flag_if_conversion) Optimization
1875 Perform conversion of conditional jumps to branchless equivalents.
1877 fif-conversion2
1878 Common Var(flag_if_conversion2) Optimization
1879 Perform conversion of conditional jumps to conditional execution.
1881 fstack-reuse=
1882 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1883 -fstack-reuse=[all|named_vars|none]     Set stack reuse level for local variables.
1885 Enum
1886 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1888 EnumValue
1889 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1891 EnumValue
1892 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1894 EnumValue
1895 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1897 ftree-loop-if-convert
1898 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1899 Convert conditional jumps in innermost loops to branchless equivalents.
1901 ftree-loop-if-convert-stores
1902 Common Ignore
1903 Does nothing. Preserved for backward compatibility.
1905 ; -finhibit-size-directive inhibits output of .size for ELF.
1906 ; This is used only for compiling crtstuff.c,
1907 ; and it may be extended to other effects
1908 ; needed for crtstuff.c on other systems.
1909 finhibit-size-directive
1910 Common Var(flag_inhibit_size_directive)
1911 Do not generate .size directives.
1913 findirect-inlining
1914 Common Var(flag_indirect_inlining) Optimization
1915 Perform indirect inlining.
1917 ; General flag to enable inlining.  Specifying -fno-inline will disable
1918 ; all inlining apart from always-inline functions.
1919 finline
1920 Common Var(flag_no_inline,0) Init(0) Optimization
1921 Enable inlining of function declared \"inline\", disabling disables all inlining.
1923 finline-small-functions
1924 Common Var(flag_inline_small_functions) Optimization
1925 Integrate functions into their callers when code size is known not to grow.
1927 finline-functions
1928 Common Var(flag_inline_functions) Optimization
1929 Integrate functions not declared \"inline\" into their callers when profitable.
1931 finline-functions-called-once
1932 Common Var(flag_inline_functions_called_once) Optimization
1933 Integrate functions only required by their single caller.
1935 finline-limit-
1936 Common RejectNegative Joined Alias(finline-limit=)
1938 finline-limit=
1939 Common RejectNegative Joined UInteger
1940 -finline-limit=<number> Limit the size of inlined functions to <number>.
1942 finline-atomics
1943 Common Var(flag_inline_atomics) Init(1) Optimization
1944 Inline __atomic operations when a lock free instruction sequence is available.
1946 fcf-protection
1947 Common RejectNegative Alias(fcf-protection=,full)
1949 fcf-protection=
1950 Common Joined RejectNegative Enum(cf_protection_level) EnumSet Var(flag_cf_protection) Init(CF_NONE)
1951 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
1952 instructions have valid targets.
1954 Enum
1955 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1957 EnumValue
1958 Enum(cf_protection_level) String(full) Value(CF_FULL) Set(1)
1960 EnumValue
1961 Enum(cf_protection_level) String(branch) Value(CF_BRANCH) Set(2)
1963 EnumValue
1964 Enum(cf_protection_level) String(return) Value(CF_RETURN) Set(3)
1966 EnumValue
1967 Enum(cf_protection_level) String(check) Value(CF_CHECK) Set(4)
1969 EnumValue
1970 Enum(cf_protection_level) String(none) Value(CF_NONE) Set(1)
1972 finstrument-functions
1973 Common Var(flag_instrument_function_entry_exit,1)
1974 Instrument function entry and exit with profiling calls.
1976 finstrument-functions-once
1977 Common Var(flag_instrument_function_entry_exit,2)
1978 Instrument function entry and exit with profiling calls invoked once.
1980 finstrument-functions-exclude-function-list=
1981 Common RejectNegative Joined
1982 -finstrument-functions-exclude-function-list=name,...   Do not instrument listed functions.
1984 finstrument-functions-exclude-file-list=
1985 Common RejectNegative Joined
1986 -finstrument-functions-exclude-file-list=filename,...   Do not instrument functions listed in files.
1988 fipa-cp
1989 Common Var(flag_ipa_cp) Optimization
1990 Perform interprocedural constant propagation.
1992 fipa-cp-clone
1993 Common Var(flag_ipa_cp_clone) Optimization
1994 Perform cloning to make Interprocedural constant propagation stronger.
1996 fipa-cp-alignment
1997 Common Ignore
1998 Does nothing.  Preserved for backward compatibility.
2000 fipa-bit-cp
2001 Common Var(flag_ipa_bit_cp) Optimization
2002 Perform interprocedural bitwise constant propagation.
2004 fipa-modref
2005 Common Var(flag_ipa_modref) Optimization
2006 Perform interprocedural modref analysis.
2008 fipa-profile
2009 Common Var(flag_ipa_profile) Init(0) Optimization
2010 Perform interprocedural profile propagation.
2012 fipa-pta
2013 Common Var(flag_ipa_pta) Init(0) Optimization
2014 Perform interprocedural points-to analysis.
2016 fipa-pure-const
2017 Common Var(flag_ipa_pure_const) Init(0) Optimization
2018 Discover pure and const functions.
2020 fipa-icf
2021 Common Var(flag_ipa_icf) Optimization
2022 Perform Identical Code Folding for functions and read-only variables.
2024 fipa-icf-functions
2025 Common Var(flag_ipa_icf_functions) Optimization
2026 Perform Identical Code Folding for functions.
2028 fipa-icf-variables
2029 Common Var(flag_ipa_icf_variables) Optimization
2030 Perform Identical Code Folding for variables.
2032 fipa-reference
2033 Common Var(flag_ipa_reference) Init(0) Optimization
2034 Discover read-only and non addressable static variables.
2036 fipa-reference-addressable
2037 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
2038 Discover read-only, write-only and non-addressable static variables.
2040 fipa-stack-alignment
2041 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
2042 Reduce stack alignment on call sites if possible.
2044 fipa-matrix-reorg
2045 Common Ignore
2046 Does nothing. Preserved for backward compatibility.
2048 fipa-struct-reorg
2049 Common Ignore
2050 Does nothing. Preserved for backward compatibility.
2052 fipa-vrp
2053 Common Var(flag_ipa_vrp) Optimization
2054 Perform IPA Value Range Propagation.
2056 fira-algorithm=
2057 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
2058 -fira-algorithm=[CB|priority]   Set the used IRA algorithm.
2060 fipa-strict-aliasing
2061 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
2062 Assume strict aliasing rules apply across (uninlined) function boundaries.
2064 Enum
2065 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
2067 EnumValue
2068 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2070 EnumValue
2071 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2073 fira-region=
2074 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2075 -fira-region=[one|all|mixed]    Set regions for IRA.
2077 Enum
2078 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2080 EnumValue
2081 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2083 EnumValue
2084 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2086 EnumValue
2087 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2089 fira-hoist-pressure
2090 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2091 Use IRA based register pressure calculation
2092 in RTL hoist optimizations.
2094 fira-loop-pressure
2095 Common Var(flag_ira_loop_pressure) Optimization
2096 Use IRA based register pressure calculation
2097 in RTL loop optimizations.
2099 fira-share-save-slots
2100 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2101 Share slots for saving different hard registers.
2103 fira-share-spill-slots
2104 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2105 Share stack slots for spilled pseudo-registers.
2107 fira-verbose=
2108 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2109 -fira-verbose=<number>  Control IRA's level of diagnostic messages.
2111 fivopts
2112 Common Var(flag_ivopts) Init(1) Optimization
2113 Optimize induction variables on trees.
2115 fjump-tables
2116 Common Var(flag_jump_tables) Init(1) Optimization
2117 Use jump tables for sufficiently large switch statements.
2119 fbit-tests
2120 Common Var(flag_bit_tests) Init(1) Optimization
2121 Use bit tests for sufficiently large switch statements.
2123 fkeep-inline-functions
2124 Common Var(flag_keep_inline_functions)
2125 Generate code for functions even if they are fully inlined.
2127 fkeep-static-functions
2128 Common Var(flag_keep_static_functions)
2129 Generate code for static functions even if they are never called.
2131 fkeep-static-consts
2132 Common Var(flag_keep_static_consts) Init(1)
2133 Emit static const variables even if they are not used.
2135 fleading-underscore
2136 Common Var(flag_leading_underscore) Init(-1)
2137 Give external symbols a leading underscore.
2139 floop-optimize
2140 Common Ignore
2141 Does nothing.  Preserved for backward compatibility.
2143 flra-remat
2144 Common Var(flag_lra_remat) Optimization
2145 Do CFG-sensitive rematerialization in LRA.
2147 flto
2148 Common
2149 Enable link-time optimization.
2151 flto=
2152 Common RejectNegative Joined Var(flag_lto)
2153 Link-time optimization with number of parallel jobs or jobserver.
2155 Enum
2156 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2158 EnumValue
2159 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2161 EnumValue
2162 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2164 EnumValue
2165 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2167 EnumValue
2168 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2170 EnumValue
2171 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2173 flto-partition=
2174 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2175 Specify the algorithm to partition symbols and vars at linktime.
2177 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2178 flto-compression-level=
2179 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2180 Use zlib/zstd compression level <number> for IL.
2182 flto-odr-type-merging
2183 Common Ignore
2184 Does nothing.  Preserved for backward compatibility.
2186 flto-report
2187 Common Var(flag_lto_report) Init(0)
2188 Report various link-time optimization statistics.
2190 flto-report-wpa
2191 Common Var(flag_lto_report_wpa) Init(0)
2192 Report various link-time optimization statistics for WPA only.
2194 fmath-errno
2195 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2196 Set errno after built-in math functions.
2198 fmax-errors=
2199 Common Joined RejectNegative UInteger Var(flag_max_errors)
2200 -fmax-errors=<number>   Maximum number of errors to report.
2202 fmem-report
2203 Common Var(mem_report)
2204 Report on permanent memory allocation.
2206 fmem-report-wpa
2207 Common Var(mem_report_wpa)
2208 Report on permanent memory allocation in WPA only.
2210 ; This will attempt to merge constant section constants, if 1 only
2211 ; string constants and constants from constant pool, if 2 also constant
2212 ; variables.
2213 fmerge-all-constants
2214 Common Var(flag_merge_constants,2) Init(1)
2215 Attempt to merge identical constants and constant variables.
2217 fmerge-constants
2218 Common Var(flag_merge_constants,1)
2219 Attempt to merge identical constants across compilation units.
2221 fmerge-debug-strings
2222 Common Var(flag_merge_debug_strings) Init(1)
2223 Attempt to merge identical debug strings across compilation units.
2225 fmessage-length=
2226 Common RejectNegative Joined UInteger
2227 -fmessage-length=<number>       Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping.
2229 fmodulo-sched
2230 Common Var(flag_modulo_sched) Optimization
2231 Perform SMS based modulo scheduling before the first scheduling pass.
2233 fmodulo-sched-allow-regmoves
2234 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2235 Perform SMS based modulo scheduling with register moves allowed.
2237 fmove-loop-invariants
2238 Common Var(flag_move_loop_invariants) Optimization
2239 Move loop invariant computations out of loops.
2241 fmove-loop-stores
2242 Common Var(flag_move_loop_stores) Optimization
2243 Move stores out of loops.
2245 fmultiflags
2246 Common Driver
2247 Building block for specs-based multilib-aware TFLAGS.
2249 fdce
2250 Common Var(flag_dce) Init(1) Optimization
2251 Use the RTL dead code elimination pass.
2253 fdse
2254 Common Var(flag_dse) Init(0) Optimization
2255 Use the RTL dead store elimination pass.
2257 freschedule-modulo-scheduled-loops
2258 Common Var(flag_resched_modulo_sched) Optimization
2259 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2261 fnon-call-exceptions
2262 Common Var(flag_non_call_exceptions) Optimization
2263 Support synchronous non-call exceptions.
2265 foffload=
2266 Driver Joined MissingArgError(targets missing after %qs)
2268 foffload-options=
2269 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2270 -foffload-options=<targets>=<options>   Specify options for the offloading targets.
2272 foffload-abi=
2273 Common Joined RejectNegative Enum(offload_abi)
2274 -foffload-abi=[lp64|ilp32]      Set the ABI to use in an offload compiler.
2276 Enum
2277 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2279 EnumValue
2280 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2282 EnumValue
2283 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2285 fomit-frame-pointer
2286 Common Var(flag_omit_frame_pointer) Optimization
2287 When possible do not generate stack frames.
2289 fopenmp-target-simd-clone
2290 Common Alias(fopenmp-target-simd-clone=,any,none)
2292 fopenmp-target-simd-clone=
2293 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2294 Generate SIMD clones for functions with the OpenMP declare target directive.
2296 Enum
2297 Name(target_simd_clone_device) Type(int)
2299 EnumValue
2300 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2302 EnumValue
2303 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2305 EnumValue
2306 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2308 EnumValue
2309 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2311 fopt-info
2312 Common Var(flag_opt_info) Optimization
2313 Enable all optimization info dumps on stderr.
2315 fopt-info-
2316 Common Joined RejectNegative Var(common_deferred_options) Defer
2317 -fopt-info[-<type>=filename]    Dump compiler optimization details.
2319 fsave-optimization-record
2320 Common Var(flag_save_optimization_record) Optimization
2321 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2323 foptimize-register-move
2324 Common Ignore
2325 Does nothing. Preserved for backward compatibility.
2327 foptimize-sibling-calls
2328 Common Var(flag_optimize_sibling_calls) Optimization
2329 Optimize sibling and tail recursive calls.
2331 fpartial-inlining
2332 Common Var(flag_partial_inlining) Optimization
2333 Perform partial inlining.
2335 fpre-ipa-mem-report
2336 Common Var(pre_ipa_mem_report)
2337 Report on memory allocation before interprocedural optimization.
2339 fpost-ipa-mem-report
2340 Common Var(post_ipa_mem_report)
2341 Report on memory allocation before interprocedural optimization.
2343 fpack-struct
2344 Common Var(flag_pack_struct) Optimization
2345 Pack structure members together without holes.
2347 fpack-struct=
2348 Common RejectNegative Joined UInteger Optimization
2349 -fpack-struct=<number>  Set initial maximum structure member alignment.
2351 fpcc-struct-return
2352 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2353 Return small aggregates in memory, not registers.
2355 fpeel-loops
2356 Common Var(flag_peel_loops) Optimization
2357 Perform loop peeling.
2359 fpeephole
2360 Common Var(flag_no_peephole,0) Optimization
2361 Enable machine specific peephole optimizations.
2363 fpeephole2
2364 Common Var(flag_peephole2) Optimization
2365 Enable an RTL peephole pass before sched2.
2367 fPIC
2368 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2369 Generate position-independent code if possible (large mode).
2371 fPIE
2372 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2373 Generate position-independent code for executables if possible (large mode).
2375 fpic
2376 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2377 Generate position-independent code if possible (small mode).
2379 fpie
2380 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2381 Generate position-independent code for executables if possible (small mode).
2383 fplt
2384 Common Var(flag_plt) Init(1) Optimization
2385 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2387 fplugin=
2388 Common Joined RejectNegative Var(common_deferred_options) Defer
2389 Specify a plugin to load.
2391 fplugin-arg-
2392 Common Joined RejectNegative Var(common_deferred_options) Defer
2393 -fplugin-arg-<name>-<key>[=<value>]     Specify argument <key>=<value> for plugin <name>.
2395 fpredictive-commoning
2396 Common Var(flag_predictive_commoning) Optimization
2397 Run predictive commoning optimization.
2399 fprefetch-loop-arrays
2400 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2401 Generate prefetch instructions, if available, for arrays in loops.
2403 fprofile
2404 Common Var(profile_flag)
2405 Enable basic program profiling code.
2407 fprofile-abs-path
2408 Common Var(profile_abs_path_flag)
2409 Generate absolute source path names for gcov.
2411 fprofile-arcs
2412 Common Var(profile_arc_flag)
2413 Insert arc-based program profiling code.
2415 fprofile-dir=
2416 Common Joined RejectNegative Var(profile_data_prefix)
2417 Set the top-level directory for storing the profile data.
2418 The default is 'pwd'.
2420 fprofile-note=
2421 Common Joined RejectNegative Var(profile_note_location)
2422 Select the name for storing the profile note file.
2424 fprofile-correction
2425 Common Var(flag_profile_correction)
2426 Enable correction of flow inconsistent profile data input.
2428 fprofile-update=
2429 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2430 -fprofile-update=[single|atomic|prefer-atomic]  Set the profile update method.
2432 fprofile-filter-files=
2433 Common Joined RejectNegative Var(flag_profile_filter_files)
2434 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2436 fprofile-exclude-files=
2437 Common Joined RejectNegative Var(flag_profile_exclude_files)
2438 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2440 Enum
2441 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2443 EnumValue
2444 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2446 EnumValue
2447 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2449 EnumValue
2450 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2452 fprofile-reproducible=
2453 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2454 -fprofile-reproducible=[serial|parallel-runs|multithreaded]     Control level of reproducibility of profile gathered by -fprofile-generate.
2456 Enum
2457 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2459 EnumValue
2460 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2462 EnumValue
2463 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2465 EnumValue
2466 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2468 fprofile-prefix-path=
2469 Common Joined RejectNegative Var(profile_prefix_path)
2470 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2472 fprofile-prefix-map=
2473 Common Joined RejectNegative Var(common_deferred_options) Defer
2474 -fprofile-prefix-map=<old>=<new>        Map one directory name to another in GCOV coverage result.
2476 fprofile-generate
2477 Common
2478 Enable common options for generating profile info for profile feedback directed optimizations.
2480 fprofile-generate=
2481 Common Joined RejectNegative
2482 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2484 fprofile-info-section
2485 Common RejectNegative
2486 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2488 fprofile-info-section=
2489 Common Joined RejectNegative Var(profile_info_section)
2490 Register the profile information in the specified section instead of using a constructor/destructor.
2492 fprofile-partial-training
2493 Common Var(flag_profile_partial_training) Optimization
2494 Do not assume that functions never executed during the train run are cold.
2496 fprofile-use
2497 Common Var(flag_profile_use)
2498 Enable common options for performing profile feedback directed optimizations.
2500 fprofile-use=
2501 Common Joined RejectNegative
2502 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2504 fprofile-values
2505 Common Var(flag_profile_values)
2506 Insert code to profile values of expressions.
2508 fprofile-report
2509 Common Var(profile_report)
2510 Report on consistency of profile.
2512 fprofile-reorder-functions
2513 Common Var(flag_profile_reorder_functions) Optimization
2514 Enable function reordering that improves code placement.
2516 fpatchable-function-entry=
2517 Common Var(flag_patchable_function_entry) Joined Optimization
2518 Insert NOP instructions at each function entry.
2520 frandom-seed
2521 Common Var(common_deferred_options) Defer
2523 frandom-seed=
2524 Common Joined RejectNegative Var(common_deferred_options) Defer
2525 -frandom-seed=<string>  Make compile reproducible using <string>.
2527 ; This switch causes the command line that was used to create an
2528 ; object file to be recorded into the object file.  The exact format
2529 ; of this recording is target and binary file format dependent.
2530 ; It is related to the -fverbose-asm switch, but that switch only
2531 ; records information in the assembler output file as comments, so
2532 ; they never reach the object file.
2533 frecord-gcc-switches
2534 Common Var(flag_record_gcc_switches)
2535 Record gcc command line switches in the object file.
2537 freg-struct-return
2538 Common Var(flag_pcc_struct_return,0) Optimization
2539 Return small aggregates in registers.
2541 fregmove
2542 Common Ignore
2543 Does nothing. Preserved for backward compatibility.
2545 flifetime-dse
2546 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2547 Tell DSE that the storage for a C++ object is dead when the constructor
2548 starts and when the destructor finishes.
2550 flifetime-dse=
2551 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2553 flive-patching
2554 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2556 flive-patching=
2557 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2558 -flive-patching=[inline-only-static|inline-clone]       Control IPA
2559 optimizations to provide a safe compilation for live-patching.  At the same
2560 time, provides multiple-level control on the enabled IPA optimizations.
2562 Enum
2563 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2565 EnumValue
2566 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2568 EnumValue
2569 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2571 fallocation-dce
2572 Common Var(flag_allocation_dce) Init(1) Optimization
2573 Tell DCE to remove unused C++ allocations.
2575 flive-range-shrinkage
2576 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2577 Relief of register pressure through live range shrinkage.
2579 frename-registers
2580 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2581 Perform a register renaming optimization pass.
2583 fschedule-fusion
2584 Common Var(flag_schedule_fusion) Init(2) Optimization
2585 Perform a target dependent instruction fusion optimization pass.
2587 freorder-blocks
2588 Common Var(flag_reorder_blocks) Optimization
2589 Reorder basic blocks to improve code placement.
2591 freorder-blocks-algorithm=
2592 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2593 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2595 Enum
2596 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2598 EnumValue
2599 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2601 EnumValue
2602 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2604 freorder-blocks-and-partition
2605 Common Var(flag_reorder_blocks_and_partition) Optimization
2606 Reorder basic blocks and partition into hot and cold sections.
2608 freorder-functions
2609 Common Var(flag_reorder_functions) Optimization
2610 Reorder functions to improve code placement.
2612 frerun-cse-after-loop
2613 Common Var(flag_rerun_cse_after_loop) Optimization
2614 Add a common subexpression elimination pass after loop optimizations.
2616 frerun-loop-opt
2617 Common Ignore
2618 Does nothing.  Preserved for backward compatibility.
2620 frounding-math
2621 Common Var(flag_rounding_math) Optimization SetByCombined
2622 Disable optimizations that assume default FP rounding behavior.
2624 fsched-interblock
2625 Common Var(flag_schedule_interblock) Init(1) Optimization
2626 Enable scheduling across basic blocks.
2628 fsched-pressure
2629 Common Var(flag_sched_pressure) Init(0) Optimization
2630 Enable register pressure sensitive insn scheduling.
2632 fsched-spec
2633 Common Var(flag_schedule_speculative) Init(1) Optimization
2634 Allow speculative motion of non-loads.
2636 fsched-spec-load
2637 Common Var(flag_schedule_speculative_load) Optimization
2638 Allow speculative motion of some loads.
2640 fsched-spec-load-dangerous
2641 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2642 Allow speculative motion of more loads.
2644 fsched-verbose=
2645 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2646 -fsched-verbose=<number>        Set the verbosity level of the scheduler.
2648 fsched2-use-superblocks
2649 Common Var(flag_sched2_use_superblocks) Optimization
2650 If scheduling post reload, do superblock scheduling.
2652 fsched2-use-traces
2653 Common Ignore
2654 Does nothing.  Preserved for backward compatibility.
2656 fschedule-insns
2657 Common Var(flag_schedule_insns) Optimization
2658 Reschedule instructions before register allocation.
2660 fschedule-insns2
2661 Common Var(flag_schedule_insns_after_reload) Optimization
2662 Reschedule instructions after register allocation.
2664 ; This flag should be on when a target implements non-trivial
2665 ; scheduling hooks, maybe saving some information for its own sake.
2666 ; On IA64, for example, this is used for correct bundling.
2667 fselective-scheduling
2668 Common Var(flag_selective_scheduling) Optimization
2669 Schedule instructions using selective scheduling algorithm.
2671 fselective-scheduling2
2672 Common Var(flag_selective_scheduling2) Optimization
2673 Run selective scheduling after reload.
2675 fself-test=
2676 Common Undocumented Joined Var(flag_self_test)
2677 Run self-tests, using the given path to locate test files.
2679 fsel-sched-pipelining
2680 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2681 Perform software pipelining of inner loops during selective scheduling.
2683 fsel-sched-pipelining-outer-loops
2684 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2685 Perform software pipelining of outer loops during selective scheduling.
2687 fsel-sched-reschedule-pipelined
2688 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2689 Reschedule pipelined regions without pipelining.
2691 fsemantic-interposition
2692 Common Var(flag_semantic_interposition) Init(1) Optimization
2693 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2695 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2696 ; of stalled insns into the ready list.
2697 fsched-stalled-insns
2698 Common Var(flag_sched_stalled_insns) Optimization UInteger
2699 Allow premature scheduling of queued insns.
2701 fsched-stalled-insns=
2702 Common RejectNegative Joined UInteger Optimization
2703 -fsched-stalled-insns=<number>  Set number of queued insns that can be prematurely scheduled.
2705 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2706 ; be examined for a dependency on a stalled insn that is candidate for
2707 ; premature removal from the queue of stalled insns into the ready list (has
2708 ; an effect only if the flag 'sched_stalled_insns' is set).
2709 fsched-stalled-insns-dep
2710 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2711 Set dependence distance checking in premature scheduling of queued insns.
2713 fsched-stalled-insns-dep=
2714 Common RejectNegative Joined UInteger Optimization
2715 -fsched-stalled-insns-dep=<number>      Set dependence distance checking in premature scheduling of queued insns.
2717 fsched-group-heuristic
2718 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2719 Enable the group heuristic in the scheduler.
2721 fsched-critical-path-heuristic
2722 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2723 Enable the critical path heuristic in the scheduler.
2725 fsched-spec-insn-heuristic
2726 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2727 Enable the speculative instruction heuristic in the scheduler.
2729 fsched-rank-heuristic
2730 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2731 Enable the rank heuristic in the scheduler.
2733 fsched-last-insn-heuristic
2734 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2735 Enable the last instruction heuristic in the scheduler.
2737 fsched-dep-count-heuristic
2738 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2739 Enable the dependent count heuristic in the scheduler.
2741 fsection-anchors
2742 Common Var(flag_section_anchors) Optimization
2743 Access data in the same section from shared anchor points.
2745 fsee
2746 Common Ignore
2747 Does nothing.  Preserved for backward compatibility.
2749 fzee
2750 Common Ignore
2751 Does nothing.  Preserved for backward compatibility.
2753 free
2754 Common Var(flag_ree) Init(0) Optimization
2755 Turn on Redundant Extensions Elimination pass.
2757 fshow-column
2758 Common Var(flag_show_column) Init(1)
2759 Show column numbers in diagnostics, when available.  Default on.
2761 fshrink-wrap
2762 Common Var(flag_shrink_wrap) Optimization
2763 Emit function prologues only before parts of the function that need it,
2764 rather than at the top of the function.
2766 fshrink-wrap-separate
2767 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2768 Shrink-wrap parts of the prologue and epilogue separately.
2770 fsignaling-nans
2771 Common Var(flag_signaling_nans) Optimization SetByCombined
2772 Disable optimizations observable by IEEE signaling NaNs.
2774 fsigned-zeros
2775 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2776 Disable floating point optimizations that ignore the IEEE signedness of zero.
2778 fsingle-precision-constant
2779 Common Var(flag_single_precision_constant) Optimization
2780 Convert floating point constants to single precision constants.
2782 fsplit-ivs-in-unroller
2783 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2784 Split lifetimes of induction variables when loops are unrolled.
2786 fsplit-stack
2787 Common Var(flag_split_stack) Init(-1)
2788 Generate discontiguous stack frames.
2790 fsplit-wide-types
2791 Common Var(flag_split_wide_types) Optimization
2792 Split wide types into independent registers.
2794 fsplit-wide-types-early
2795 Common Var(flag_split_wide_types_early) Optimization
2796 Split wide types into independent registers earlier.
2798 fssa-backprop
2799 Common Var(flag_ssa_backprop) Init(1) Optimization
2800 Enable backward propagation of use properties at the SSA level.
2802 fssa-phiopt
2803 Common Var(flag_ssa_phiopt) Optimization
2804 Optimize conditional patterns using SSA PHI nodes.
2806 fstdarg-opt
2807 Common Var(flag_stdarg_opt) Init(1) Optimization
2808 Optimize amount of stdarg registers saved to stack at start of function.
2810 fvariable-expansion-in-unroller
2811 Common Var(flag_variable_expansion_in_unroller) Optimization
2812 Apply variable expansion when loops are unrolled.
2814 fstack-check=
2815 Common RejectNegative Joined Optimization
2816 -fstack-check=[no|generic|specific]     Insert stack checking code into the program.
2818 fstack-check
2819 Common Alias(fstack-check=, specific, no)
2820 Insert stack checking code into the program.  Same as -fstack-check=specific.
2822 fstack-clash-protection
2823 Common Var(flag_stack_clash_protection) Optimization
2824 Insert code to probe each page of stack space as it is allocated to protect
2825 from stack-clash style attacks.
2827 fstack-limit
2828 Common Var(common_deferred_options) Defer
2830 fstack-limit-register=
2831 Common RejectNegative Joined Var(common_deferred_options) Defer
2832 -fstack-limit-register=<register>       Trap if the stack goes past <register>.
2834 fstack-limit-symbol=
2835 Common RejectNegative Joined Var(common_deferred_options) Defer
2836 -fstack-limit-symbol=<name>     Trap if the stack goes past symbol <name>.
2838 fstack-protector
2839 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2840 Use propolice as a stack protection method.
2842 fstack-protector-all
2843 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2844 Use a stack protection method for every function.
2846 fstack-protector-strong
2847 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2848 Use a smart stack protection method for certain functions.
2850 fstack-protector-explicit
2851 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2852 Use stack protection method only for functions with the stack_protect attribute.
2854 fstack-usage
2855 Common RejectNegative Var(flag_stack_usage)
2856 Output stack usage information on a per-function basis.
2858 fstrength-reduce
2859 Common Ignore
2860 Does nothing.  Preserved for backward compatibility.
2862 ; Nonzero if we should do (language-dependent) alias analysis.
2863 ; Typically, this analysis will assume that expressions of certain
2864 ; types do not alias expressions of certain other types.  Only used
2865 ; if alias analysis (in general) is enabled.
2866 fstrict-aliasing
2867 Common Var(flag_strict_aliasing) Optimization
2868 Assume strict aliasing rules apply.
2870 fstrict-overflow
2871 Common
2872 Treat signed overflow as undefined.  Negated as -fwrapv -fwrapv-pointer.
2874 fsync-libcalls
2875 Common Var(flag_sync_libcalls) Init(1)
2876 Implement __atomic operations via libcalls to legacy __sync functions.
2878 fsyntax-only
2879 Common Var(flag_syntax_only)
2880 Check for syntax errors, then stop.
2882 ftest-coverage
2883 Common Var(flag_test_coverage)
2884 Create data files needed by \"gcov\".
2886 fthread-jumps
2887 Common Var(flag_thread_jumps) Optimization
2888 Perform jump threading optimizations.
2890 ftime-report
2891 Common Var(time_report)
2892 Report the time taken by each compiler pass.
2894 ftime-report-details
2895 Common Var(time_report_details)
2896 Record times taken by sub-phases separately.
2898 ftls-model=
2899 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2900 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]      Set the default thread-local storage code generation model.
2902 Enum
2903 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2905 EnumValue
2906 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2908 EnumValue
2909 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2911 EnumValue
2912 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2914 EnumValue
2915 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2917 ftoplevel-reorder
2918 Common Var(flag_toplevel_reorder) Init(2) Optimization
2919 Reorder top level functions, variables, and asms.
2921 ftracer
2922 Common Var(flag_tracer) Optimization
2923 Perform superblock formation via tail duplication.
2925 ftrampolines
2926 Common Var(flag_trampolines) Init(HEAP_TRAMPOLINES_INIT)
2927 For targets that normally need trampolines for nested functions, always
2928 generate them instead of using descriptors.
2930 ftrampoline-impl=
2931 Common Joined RejectNegative Enum(trampoline_impl) Var(flag_trampoline_impl) Init(HEAP_TRAMPOLINES_INIT ? TRAMPOLINE_IMPL_HEAP : TRAMPOLINE_IMPL_STACK)
2932 Whether trampolines are generated in executable memory rather than
2933 executable stack.
2935 Enum
2936 Name(trampoline_impl) Type(enum trampoline_impl) UnknownError(unknown trampoline implementation %qs)
2938 EnumValue
2939 Enum(trampoline_impl) String(stack) Value(TRAMPOLINE_IMPL_STACK)
2941 EnumValue
2942 Enum(trampoline_impl) String(heap) Value(TRAMPOLINE_IMPL_HEAP)
2945 ; Zero means that floating-point math operations cannot generate a
2946 ; (user-visible) trap.  This is the case, for example, in nonstop
2947 ; IEEE 754 arithmetic.
2948 ftrapping-math
2949 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
2950 Assume floating-point operations can trap.
2952 ftrapv
2953 Common Var(flag_trapv) Optimization
2954 Trap for signed overflow in addition, subtraction and multiplication.
2956 ftree-ccp
2957 Common Var(flag_tree_ccp) Optimization
2958 Enable SSA-CCP optimization on trees.
2960 ftree-bit-ccp
2961 Common Var(flag_tree_bit_ccp) Optimization
2962 Enable SSA-BIT-CCP optimization on trees.
2964 ftree-store-ccp
2965 Common Ignore
2966 Does nothing.  Preserved for backward compatibility.
2968 ftree-ch
2969 Common Var(flag_tree_ch) Optimization
2970 Enable loop header copying on trees.
2972 ftree-coalesce-inlined-vars
2973 Common Ignore RejectNegative
2974 Does nothing.  Preserved for backward compatibility.
2976 ftree-coalesce-vars
2977 Common Var(flag_tree_coalesce_vars) Optimization
2978 Enable SSA coalescing of user variables.
2980 ftree-copyrename
2981 Common Ignore
2982 Does nothing.  Preserved for backward compatibility.
2984 ftree-copy-prop
2985 Common Var(flag_tree_copy_prop) Optimization
2986 Enable copy propagation on trees.
2988 ftree-store-copy-prop
2989 Common Ignore
2990 Does nothing.  Preserved for backward compatibility.
2992 ftree-cselim
2993 Common Var(flag_tree_cselim) Optimization
2994 Transform condition stores into unconditional ones.
2996 ftree-switch-conversion
2997 Common Var(flag_tree_switch_conversion) Optimization
2998 Perform conversions of switch initializations.
3000 ftree-dce
3001 Common Var(flag_tree_dce) Optimization
3002 Enable SSA dead code elimination optimization on trees.
3004 ftree-dominator-opts
3005 Common Var(flag_tree_dom) Optimization
3006 Enable dominator optimizations.
3008 ftree-tail-merge
3009 Common Var(flag_tree_tail_merge) Optimization
3010 Enable tail merging on trees.
3012 ftree-dse
3013 Common Var(flag_tree_dse) Optimization
3014 Enable dead store elimination.
3016 ftree-forwprop
3017 Common Var(flag_tree_forwprop) Init(1) Optimization
3018 Enable forward propagation on trees.
3020 ftree-fre
3021 Common Var(flag_tree_fre) Optimization
3022 Enable Full Redundancy Elimination (FRE) on trees.
3024 foptimize-strlen
3025 Common Var(flag_optimize_strlen) Optimization
3026 Enable string length optimizations on trees.
3028 fisolate-erroneous-paths-dereference
3029 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
3030 Detect paths that trigger erroneous or undefined behavior due to
3031 dereferencing a null pointer.  Isolate those paths from the main control
3032 flow and turn the statement with erroneous or undefined behavior into a trap.
3034 fisolate-erroneous-paths-attribute
3035 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
3036 Detect paths that trigger erroneous or undefined behavior due to a null value
3037 being used in a way forbidden by a returns_nonnull or nonnull
3038 attribute.  Isolate those paths from the main control flow and turn the
3039 statement with erroneous or undefined behavior into a trap.
3041 ftree-loop-distribution
3042 Common Var(flag_tree_loop_distribution) Optimization
3043 Enable loop distribution on trees.
3045 ftree-loop-distribute-patterns
3046 Common Var(flag_tree_loop_distribute_patterns) Optimization
3047 Enable loop distribution for patterns transformed into a library call.
3049 ftree-loop-im
3050 Common Var(flag_tree_loop_im) Init(1) Optimization
3051 Enable loop invariant motion on trees.
3053 ftree-loop-linear
3054 Common Alias(floop-nest-optimize)
3055 Enable loop nest transforms.  Same as -floop-nest-optimize.
3057 ftree-loop-ivcanon
3058 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
3059 Create canonical induction variables in loops.
3061 ftree-loop-optimize
3062 Common Var(flag_tree_loop_optimize) Init(1) Optimization
3063 Enable loop optimizations on tree level.
3065 ftree-parallelize-loops=
3066 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
3067 -ftree-parallelize-loops=<number>       Enable automatic parallelization of loops.
3069 ftree-phiprop
3070 Common Var(flag_tree_phiprop) Init(1) Optimization
3071 Enable hoisting loads from conditional pointers.
3073 ftree-pre
3074 Common Var(flag_tree_pre) Optimization
3075 Enable SSA-PRE optimization on trees.
3077 ftree-partial-pre
3078 Common Var(flag_tree_partial_pre) Optimization
3079 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
3081 ftree-pta
3082 Common Var(flag_tree_pta) Optimization
3083 Perform function-local points-to analysis on trees.
3085 ftree-reassoc
3086 Common Var(flag_tree_reassoc) Init(1) Optimization
3087 Enable reassociation on tree level.
3089 ftree-salias
3090 Common Ignore
3091 Does nothing.  Preserved for backward compatibility.
3093 ftree-sink
3094 Common Var(flag_tree_sink) Optimization
3095 Enable SSA code sinking on trees.
3097 ftree-slsr
3098 Common Var(flag_tree_slsr) Optimization
3099 Perform straight-line strength reduction.
3101 ftree-sra
3102 Common Var(flag_tree_sra) Optimization
3103 Perform scalar replacement of aggregates.
3105 ftree-ter
3106 Common Var(flag_tree_ter) Optimization
3107 Replace temporary expressions in the SSA->normal pass.
3109 ftree-lrs
3110 Common Var(flag_tree_live_range_split) Optimization
3111 Perform live range splitting during the SSA->normal pass.
3113 ftree-vrp
3114 Common Var(flag_tree_vrp) Init(0) Optimization
3115 Perform Value Range Propagation on trees.
3117 fsplit-paths
3118 Common Var(flag_split_paths) Init(0) Optimization
3119 Split paths leading to loop backedges.
3121 funconstrained-commons
3122 Common Var(flag_unconstrained_commons) Optimization
3123 Assume common declarations may be overridden with ones with a larger
3124 trailing array.
3126 funit-at-a-time
3127 Common Var(flag_unit_at_a_time) Init(1)
3128 Compile whole compilation unit at a time.
3130 funreachable-traps
3131 Common Var(flag_unreachable_traps) Optimization
3132 Trap on __builtin_unreachable instead of using it for optimization.
3134 funroll-loops
3135 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3136 Perform loop unrolling when iteration count is known.
3138 funroll-all-loops
3139 Common Var(flag_unroll_all_loops) Optimization
3140 Perform loop unrolling for all loops.
3142 funroll-completely-grow-size
3143 Undocumented Var(flag_cunroll_grow_size) Optimization
3144 ; Internal undocumented flag, allow size growth during complete unrolling
3146 ; Nonzero means that loop optimizer may assume that the induction variables
3147 ; that control loops do not overflow and that the loops with nontrivial
3148 ; exit condition are not infinite
3149 funsafe-loop-optimizations
3150 Common Ignore
3151 Does nothing.  Preserved for backward compatibility.
3153 fassociative-math
3154 Common Var(flag_associative_math) SetByCombined Optimization
3155 Allow optimization for floating-point arithmetic which may change the
3156 result of the operation due to rounding.
3158 freciprocal-math
3159 Common Var(flag_reciprocal_math) SetByCombined Optimization
3160 Same as -fassociative-math for expressions which include division.
3162 ; Nonzero means that unsafe floating-point math optimizations are allowed
3163 ; for the sake of speed.  IEEE compliance is not guaranteed, and operations
3164 ; are allowed to assume that their arguments and results are "normal"
3165 ; (e.g., nonnegative for SQRT).
3166 funsafe-math-optimizations
3167 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3168 Allow math optimizations that may violate IEEE or ISO standards.
3170 funswitch-loops
3171 Common Var(flag_unswitch_loops) Optimization
3172 Perform loop unswitching.
3174 fsplit-loops
3175 Common Var(flag_split_loops) Optimization
3176 Perform loop splitting.
3178 fversion-loops-for-strides
3179 Common Var(flag_version_loops_for_strides) Optimization
3180 Version loops based on whether indices have a stride of one.
3182 funwind-tables
3183 Common Var(flag_unwind_tables) Optimization
3184 Just generate unwind tables for exception handling.
3186 fuse-ld=bfd
3187 Common Driver Negative(fuse-ld=gold)
3188 Use the bfd linker instead of the default linker.
3190 fuse-ld=gold
3191 Common Driver Negative(fuse-ld=bfd)
3192 Use the gold linker instead of the default linker.
3194 fuse-ld=lld
3195 Common Driver Negative(fuse-ld=lld)
3196 Use the lld LLVM linker instead of the default linker.
3198 fuse-ld=mold
3199 Common Driver Negative(fuse-ld=mold)
3200 Use the Modern linker (MOLD) linker instead of the default linker.
3202 fuse-linker-plugin
3203 Common Undocumented Var(flag_use_linker_plugin)
3205 ; Positive if we should track variables, negative if we should run
3206 ; the var-tracking pass only to discard debug annotations, zero if
3207 ; we're not to run it.
3208 fvar-tracking
3209 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3210 Perform variable tracking.
3212 ; Positive if we should track variables at assignments, negative if
3213 ; we should run the var-tracking pass only to discard debug
3214 ; annotations.
3215 fvar-tracking-assignments
3216 Common Var(flag_var_tracking_assignments) PerFunction
3217 Perform variable tracking by annotating assignments.
3219 ; Nonzero if we should toggle flag_var_tracking_assignments after
3220 ; processing options and computing its default.  */
3221 fvar-tracking-assignments-toggle
3222 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3223 Toggle -fvar-tracking-assignments.
3225 ; Positive if we should track uninitialized variables, negative if
3226 ; we should run the var-tracking pass only to discard debug
3227 ; annotations.
3228 fvar-tracking-uninit
3229 Common Var(flag_var_tracking_uninit) PerFunction
3230 Perform variable tracking and also tag variables that are uninitialized.
3232 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3233 ftree-vectorize
3234 Common Var(flag_tree_vectorize) Optimization
3235 Enable vectorization on trees.
3237 ftree-vectorizer-verbose=
3238 Common Joined RejectNegative Ignore
3239 Does nothing.  Preserved for backward compatibility.
3241 ftree-loop-vectorize
3242 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3243 Enable loop vectorization on trees.
3245 ftree-slp-vectorize
3246 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3247 Enable basic block vectorization (SLP) on trees.
3249 fvect-cost-model=
3250 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3251 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap]  Specifies the cost model for vectorization.
3253 fsimd-cost-model=
3254 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3255 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap]  Specifies the vectorization cost model for code marked with a simd directive.
3257 Enum
3258 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3260 EnumValue
3261 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3263 EnumValue
3264 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3266 EnumValue
3267 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3269 EnumValue
3270 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3272 fvect-cost-model
3273 Common Alias(fvect-cost-model=,dynamic,unlimited)
3274 Enables the dynamic vectorizer cost model.  Preserved for backward compatibility.
3276 ftree-vect-loop-version
3277 Common Ignore
3278 Does nothing. Preserved for backward compatibility.
3280 ftree-scev-cprop
3281 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3282 Enable copy propagation of scalar-evolution information.
3284 ftrivial-auto-var-init=
3285 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3286 -ftrivial-auto-var-init=[uninitialized|pattern|zero]    Add initializations to automatic variables.
3288 Enum
3289 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3291 EnumValue
3292 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3294 EnumValue
3295 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3297 EnumValue
3298 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3300 ; -fverbose-asm causes extra commentary information to be produced in
3301 ; the generated assembly code (to make it more readable).  This option
3302 ; is generally only of use to those who actually need to read the
3303 ; generated assembly code (perhaps while debugging the compiler itself).
3304 ; -fno-verbose-asm, the default, causes the extra information
3305 ; to not be added and is useful when comparing two assembler files.
3306 fverbose-asm
3307 Common Var(flag_verbose_asm)
3308 Add extra commentary to assembler output.
3310 fvisibility=
3311 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3312 -fvisibility=[default|internal|hidden|protected]        Set the default symbol visibility.
3314 Enum
3315 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3317 EnumValue
3318 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3320 EnumValue
3321 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3323 EnumValue
3324 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3326 EnumValue
3327 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3329 fvtable-verify=
3330 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3331 Validate vtable pointers before using them.
3333 Enum
3334 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3336 EnumValue
3337 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3339 EnumValue
3340 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3342 EnumValue
3343 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3345 fvtv-counts
3346 Common Var(flag_vtv_counts)
3347 Output vtable verification counters.
3349 fvtv-debug
3350 Common Var(flag_vtv_debug)
3351 Output vtable verification pointer sets information.
3353 fvpt
3354 Common Var(flag_value_profile_transformations) Optimization
3355 Use expression value profiles in optimizations.
3357 fweb
3358 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3359 Construct webs and split unrelated uses of single variable.
3361 ftree-builtin-call-dce
3362 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3363 Enable conditional dead code elimination for builtin calls.
3365 fwhole-program
3366 Common Var(flag_whole_program) Init(0)
3367 Perform whole program optimizations.
3369 fwrapv-pointer
3370 Common Var(flag_wrapv_pointer) Optimization
3371 Assume pointer overflow wraps around.
3373 fwrapv
3374 Common Var(flag_wrapv) Optimization
3375 Assume signed arithmetic overflow wraps around.
3377 fzero-initialized-in-bss
3378 Common Var(flag_zero_initialized_in_bss) Init(1)
3379 Put zero initialized data in the bss section.
3381 fzero-call-used-regs=
3382 Common RejectNegative Joined
3383 Clear call-used registers upon function return.
3386 Common Driver RejectNegative JoinedOrMissing
3387 Generate debug information in default format.
3389 gas-loc-support
3390 Common Driver Var(dwarf2out_as_loc_support)
3391 Assume assembler support for (DWARF2+) .loc directives.
3393 gas-locview-support
3394 Common Driver Var(dwarf2out_as_locview_support)
3395 Assume assembler support for view in (DWARF2+) .loc directives.
3397 gcodeview
3398 Common Driver JoinedOrMissing
3399 Generate debug information in CodeView format.
3401 gcoff
3402 Common Driver WarnRemoved
3403 Does nothing.  Preserved for backward compatibility.
3405 gcoff1
3406 Common Driver WarnRemoved
3407 Does nothing.  Preserved for backward compatibility.
3409 gcoff2
3410 Common Driver WarnRemoved
3411 Does nothing.  Preserved for backward compatibility.
3413 gcoff3
3414 Common Driver WarnRemoved
3415 Does nothing.  Preserved for backward compatibility.
3417 gcolumn-info
3418 Common Driver Var(debug_column_info,1) Init(1)
3419 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3421 ; The CTF generation process feeds off DWARF dies.  This option implicitly
3422 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3423 gctf
3424 Common Driver RejectNegative JoinedOrMissing
3425 Generate CTF debug information at default level.
3427 gbtf
3428 Common Driver RejectNegative JoinedOrMissing
3429 Generate BTF debug information at default level.
3431 gdwarf
3432 Common Driver JoinedOrMissing RejectNegative
3433 Generate debug information in default version of DWARF format.
3435 gdwarf-
3436 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT) RejectNegative
3437 Generate debug information in DWARF v2 (or later) format.
3439 gdwarf32
3440 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3441 Use 32-bit DWARF format when emitting DWARF debug information.
3443 gdwarf64
3444 Common Driver Var(dwarf_offset_size,8) RejectNegative
3445 Use 64-bit DWARF format when emitting DWARF debug information.
3447 ggdb
3448 Common Driver JoinedOrMissing RejectNegative
3449 Generate debug information in default extended format.
3451 ginline-points
3452 Common Driver Var(debug_inline_points)
3453 Generate extended entry point information for inlined functions.
3455 ginternal-reset-location-views
3456 Common Driver Var(debug_internal_reset_location_views) Init(2)
3457 Compute locview reset points based on insn length estimates.
3459 gno-
3460 RejectNegative Joined Undocumented
3461 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3463 gno-pubnames
3464 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3465 Don't generate DWARF pubnames and pubtypes sections.
3467 gpubnames
3468 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3469 Generate DWARF pubnames and pubtypes sections.
3471 ggnu-pubnames
3472 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3473 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3475 grecord-gcc-switches
3476 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3477 Record gcc command line switches in DWARF DW_AT_producer.
3479 gsplit-dwarf
3480 Common Driver Var(dwarf_split_debug_info) Init(0)
3481 Generate debug information in separate .dwo files.
3483 gstabs
3484 Common Driver WarnRemoved
3485 Does nothing.  Preserved for backward compatibility.
3487 gstabs+
3488 Common Driver WarnRemoved
3489 Does nothing.  Preserved for backward compatibility.
3491 gstatement-frontiers
3492 Common Driver Var(debug_nonbind_markers_p) PerFunction
3493 Emit progressive recommended breakpoint locations.
3495 gstrict-dwarf
3496 Common Driver Var(dwarf_strict) Init(0)
3497 Don't emit DWARF additions beyond selected version.
3499 gdescribe-dies
3500 Common Driver Var(flag_describe_dies) Init(0)
3501 Add description attributes to some DWARF DIEs that have no name attribute.
3503 gtoggle
3504 Common Driver Var(flag_gtoggle)
3505 Toggle debug information generation.
3507 gvariable-location-views
3508 Common Driver Var(debug_variable_location_views, 1)
3509 Augment variable location lists with progressive views.
3511 gvariable-location-views=incompat5
3512 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3514 gvms
3515 Common Driver JoinedOrMissing RejectNegative
3516 Generate debug information in VMS format.
3518 gxcoff
3519 Common Driver WarnRemoved
3520 Does nothing.  Preserved for backward compatibility.
3522 gxcoff+
3523 Common Driver JoinedOrMissing  WarnRemoved
3524 Does nothing.  Preserved for backward compatibility.
3526 Enum
3527 Name(compressed_debug_sections) Type(int)
3529 ; Since -gz= is completely handled in specs, the values aren't used and we
3530 ; assign arbitrary constants.
3531 EnumValue
3532 Enum(compressed_debug_sections) String(none) Value(0)
3534 EnumValue
3535 Enum(compressed_debug_sections) String(zlib) Value(1)
3537 EnumValue
3538 Enum(compressed_debug_sections) String(zstd) Value(2)
3540 EnumValue
3541 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3544 Common Driver
3545 Generate compressed debug sections.
3548 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3549 -gz=<format>    Generate compressed debug sections in format <format>.
3552 Driver Joined Separate
3554 iplugindir=
3555 Common Joined Var(plugindir_string) Init(0)
3556 -iplugindir=<dir>       Set <dir> to be the default plugin directory.
3558 imultiarch
3559 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3560 -imultiarch <dir>       Set <dir> to be the multiarch include subdirectory.
3563 Driver Joined Separate
3566 Driver
3568 no-canonical-prefixes
3569 Driver
3571 nodefaultlibs
3572 Driver
3574 nostartfiles
3575 Driver
3577 nolibc
3578 Driver
3580 nostdlib
3581 Driver
3583 nostdlib++
3584 Driver
3587 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3588 -o <file>       Place output into <file>.
3591 Common Var(profile_flag)
3592 Enable function profiling.
3594 pass-exit-codes
3595 Driver Var(pass_exit_codes)
3597 pedantic
3598 Common Alias(Wpedantic)
3600 pedantic-errors
3601 Common Var(flag_pedantic_errors)
3602 Like -pedantic but issue them as errors.
3605 Driver
3607 pipe
3608 Driver Var(use_pipes)
3610 print-file-name=
3611 Driver JoinedOrMissing Var(print_file_name)
3613 print-libgcc-file-name
3614 Driver
3616 print-multi-directory
3617 Driver Var(print_multi_directory)
3619 print-multi-lib
3620 Driver Var(print_multi_lib)
3622 print-multi-os-directory
3623 Driver Var(print_multi_os_directory)
3625 print-multiarch
3626 Driver Var(print_multiarch)
3628 print-prog-name=
3629 Driver JoinedOrMissing Var(print_prog_name)
3631 print-search-dirs
3632 Driver Var(print_search_dirs)
3634 print-sysroot
3635 Driver Var(print_sysroot)
3637 print-sysroot-headers-suffix
3638 Driver Var(print_sysroot_headers_suffix)
3640 quiet
3641 Common Var(quiet_flag) RejectDriver
3642 Do not display functions compiled or elapsed time.
3645 Driver
3648 Driver
3650 save-temps
3651 Driver
3653 save-temps=
3654 Driver Joined
3657 Driver
3659 time
3660 Driver Var(report_times)
3662 time=
3663 Driver JoinedOrMissing
3666 Driver Joined Separate
3668 undef
3669 Driver
3670 ; C option, but driver must not handle as "-u ndef".
3673 Common Driver Var(verbose_flag)
3674 Enable verbose output.
3676 version
3677 Common Var(version_flag) RejectDriver
3678 Display the compiler's version.
3681 Common Var(inhibit_warnings)
3682 Suppress warnings.
3684 wrapper
3685 Driver Separate Var(wrapper_string)
3688 Driver Joined Separate
3690 shared
3691 Driver RejectNegative Negative(static-pie)
3692 Create a shared library.
3694 shared-libgcc
3695 Driver
3697 specs
3698 Driver Separate Alias(specs=)
3700 specs=
3701 Driver Joined
3703 static
3704 Driver
3706 static-libgcc
3707 Driver
3709 static-libgfortran
3710 Driver
3711 ; Documented for Fortran, but always accepted by driver.
3713 static-libgm2
3714 Driver
3715 ; Documented for Modula-2, but always accepted by driver.
3717 static-libphobos
3718 Driver
3719 ; Documented for D, but always accepted by driver.
3721 static-libquadmath
3722 Driver
3723 ; Documented for Fortran, but always accepted by driver.
3725 static-libstdc++
3726 Driver
3728 static-libgo
3729 Driver
3730 ; Documented for Go, but always accepted by driver.
3732 static-libasan
3733 Driver
3735 static-libhwasan
3736 Driver
3738 static-libtsan
3739 Driver
3741 static-liblsan
3742 Driver
3744 static-libubsan
3745 Driver
3747 symbolic
3748 Driver
3750 no-pie
3751 Driver RejectNegative Negative(shared)
3752 Don't create a dynamically linked position independent executable.
3755 Driver RejectNegative Negative(no-pie)
3756 Create a dynamically linked position independent executable.
3758 static-pie
3759 Driver RejectNegative Negative(pie)
3760 Create a static position independent executable.
3763 Driver Joined Separate
3765 fipa-ra
3766 Common Var(flag_ipa_ra) Optimization
3767 Use caller save register across calls if possible.
3769 ; This comment is to ensure we retain the blank line above.