testsuite: Correct vec-rlmi-rlnm.c testsuite expected result
[official-gcc.git] / gcc / common.opt
blob7e789d1c47f0f52cf7d6121e8354283cafeef991
1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2020 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 ; Language specific warning pass for unused results.
63 Variable
64 bool flag_warn_unused_result = false
66 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
67 Variable
68 int flag_generate_lto
70 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
71 Variable
72 int flag_generate_offload = 0
74 ; Nonzero means we should be saving declaration info into a .X file.
75 Variable
76 int flag_gen_aux_info = 0
78 ; Nonzero if we are compiling code for a shared library, zero for
79 ; executable.
80 Variable
81 int flag_shlib
83 ; These two are really VEC(char_p,heap) *.
85 Variable
86 void *flag_instrument_functions_exclude_functions
88 Variable
89 void *flag_instrument_functions_exclude_files
91 ; Generic structs (e.g. templates not explicitly specialized)
92 ; may not have a compilation unit associated with them, and so
93 ; may need to be treated differently from ordinary structs.
95 ; Structs only handled by reference (indirectly), will also usually
96 ; not need as much debugging information.
98 Variable
99 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
101 Variable
102 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
104 ; True if we should exit after parsing options.
105 Variable
106 bool exit_after_options
108 ; Type(s) of debugging information we are producing (if any).  See
109 ; flag-types.h for the definitions of the different possible types of
110 ; debugging information.
111 Variable
112 enum debug_info_type write_symbols = NO_DEBUG
114 ; Level of debugging information we are producing.  See flag-types.h
115 ; for the definitions of the different possible levels.
116 Variable
117 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
119 ; Nonzero means use GNU-only extensions in the generated symbolic
120 ; debugging information.  Currently, this only has an effect when
121 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
122 Variable
123 bool use_gnu_debug_info_extensions
125 ; Original value of maximum field alignment in bytes, specified via
126 ; -fpack-struct=<value>.
127 Variable
128 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
130 ; Type of stack check.
131 Variable
132 enum stack_check_type flag_stack_check = NO_STACK_CHECK
134 ; True if stack usage information needs to be computed.
135 Variable
136 bool flag_stack_usage_info = false
138 ; -dA causes debug commentary information to be produced in
139 ; the generated assembly code (to make it more readable).  This option
140 ; is generally only of use to those who actually need to read the
141 ; generated assembly code (perhaps while debugging the compiler itself).
142 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
143 ; to be a catchall for printing debug information in the assembler file.
144 Variable
145 int flag_debug_asm
147 ; How many NOP insns to place at each function entry by default
148 Variable
149 HOST_WIDE_INT function_entry_patch_area_size
151 ; And how far the real asm entry point is into this area
152 Variable
153 HOST_WIDE_INT function_entry_patch_area_start
155 ; Balance between GNAT encodings and standard DWARF to emit.
156 Variable
157 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
159 ; -dP causes the rtl to be emitted as a comment in assembly.
160 Variable
161 int flag_dump_rtl_in_asm
163 ; Whether -da was passed (used only in handle_common_deferred_options).
164 Variable
165 bool flag_dump_all_passed
167 ; Other flags saying which kinds of debugging dump have been requested.
169 Variable
170 int rtl_dump_and_exit
172 Variable
173 int flag_print_asm_name
175 ; Name of top-level original source file (what was input to cpp).
176 ; This comes from the #-command at the beginning of the actual input.
177 ; If there isn't any there, then this is the cc1 input file name.
178 Variable
179 const char *main_input_filename
181 ; Pointer to base name in main_input_filename, with directories and a
182 ; single final extension removed, and the length of this base
183 ; name.
185 Variable
186 const char *main_input_basename
188 Variable
189 int main_input_baselength
191 ; The base name used for auxiliary output files.
192 ; dump_base_name minus dump_base_ext.
194 Variable
195 const char *aux_base_name
197 ; Which options have been printed by --help.
198 Variable
199 char *help_printed
201 ; Which enums have been printed by --help.  0 = not printed, no
202 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
203 ; = printed.
204 Variable
205 char *help_enum_printed
207 ; The number of columns for --help output.
208 Variable
209 unsigned int help_columns
211 ; Whether this options structure has been through finish_options
212 Variable
213 bool flag_opts_finished
215 ; What the sanitizer should instrument
216 Variable
217 unsigned int flag_sanitize
219 ; What sanitizers should recover from errors
220 Variable
221 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
223 ; What the coverage sanitizers should instrument
224 Variable
225 unsigned int flag_sanitize_coverage
227 ; Flag whether a prefix has been added to dump_base_name
228 Variable
229 bool dump_base_name_prefixed = false
232 Driver
234 -assemble
235 Driver Alias(S)
237 -compile
238 Driver Alias(c)
240 -completion=
241 Common Driver Joined Undocumented
242 Provide bash completion for options starting with provided string.
244 -coverage
245 Driver Alias(coverage)
247 -debug
248 Common Alias(g)
250 -dump
251 Common Separate Alias(d)
253 -dump=
254 Common Joined Alias(d)
256 -dumpbase
257 Driver Common Separate Alias(dumpbase)
259 -dumpbase-ext
260 Driver Common Separate Alias(dumpbase-ext)
262 -dumpdir
263 Driver Common Separate Alias(dumpdir)
265 -entry
266 Driver Separate Alias(e)
268 -entry=
269 Driver Joined Alias(e)
271 -extra-warnings
272 Common Warning Alias(Wextra)
274 -for-assembler
275 Driver Separate Alias(Xassembler)
277 -for-assembler=
278 Driver JoinedOrMissing Alias(Xassembler)
280 -for-linker
281 Driver Separate Alias(Xlinker)
283 -for-linker=
284 Driver JoinedOrMissing Alias(Xlinker)
286 -force-link
287 Driver Separate Alias(u)
289 -force-link=
290 Driver Joined Alias(u)
292 -help
293 Common Driver Var(help_flag)
294 Display this information.
296 -help=
297 Common Driver Report Joined
298 --help=<class>  Display descriptions of a specific class of options.  <class> is one or more of optimizers, target, warnings, undocumented, params.
300 -language
301 Driver Separate Alias(x)
303 -language=
304 Driver Joined Alias(x)
306 -library-directory
307 Driver Separate Alias(L)
309 -library-directory=
310 Driver Joined Alias(L)
312 -no-canonical-prefixes
313 Driver Alias(no-canonical-prefixes)
315 -no-standard-libraries
316 Driver Alias(nostdlib)
318 -no-sysroot-suffix
319 Driver Var(no_sysroot_suffix)
321 -no-warnings
322 Common Alias(w)
324 -optimize
325 Common Alias(O)
327 -output
328 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
330 -output=
331 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
333 -pass-exit-codes
334 Driver Alias(pass-exit-codes)
336 -pedantic
337 Common Alias(Wpedantic)
339 -pedantic-errors
340 Common Alias(pedantic-errors)
342 -pie
343 Driver Alias(pie)
345 -static-pie
346 Driver Alias(static-pie)
348 -pipe
349 Driver Alias(pipe)
351 -prefix
352 Driver Separate Alias(B)
354 -prefix=
355 Driver JoinedOrMissing Alias(B)
357 -preprocess
358 Driver Alias(E)
360 -print-file-name
361 Driver Separate Alias(print-file-name=)
363 -print-file-name=
364 Driver JoinedOrMissing Alias(print-file-name=)
366 -print-libgcc-file-name
367 Driver Alias(print-libgcc-file-name)
369 -print-multi-directory
370 Driver Alias(print-multi-directory)
372 -print-multi-lib
373 Driver Alias(print-multi-lib)
375 -print-multi-os-directory
376 Driver Alias(print-multi-os-directory)
378 -print-multiarch
379 Driver Alias(print-multiarch)
381 -print-prog-name
382 Driver Separate Alias(print-prog-name=)
384 -print-prog-name=
385 Driver JoinedOrMissing Alias(print-prog-name=)
387 -print-search-dirs
388 Driver Alias(print-search-dirs)
390 -print-sysroot
391 Driver Alias(print-sysroot)
393 -print-sysroot-headers-suffix
394 Driver Alias(print-sysroot-headers-suffix)
396 -profile
397 Common Alias(p)
399 -save-temps
400 Driver Alias(save-temps)
402 -shared
403 Driver Alias(shared)
405 -specs
406 Driver Separate Alias(specs=)
408 -specs=
409 Driver Joined Alias(specs=)
411 -static
412 Driver Alias(static)
414 -symbolic
415 Driver Alias(symbolic)
417 -target-help
418 Common Driver
419 Alias for --help=target.
421 -time
422 Driver Alias(time)
424 -verbose
425 Driver Alias(v)
427 ;; The driver used to convert options such as --help into forms such
428 ;; as -fhelp; the following four entries are for compatibility with
429 ;; any direct uses of those (undocumented) -f forms
430 fhelp
431 Common Driver Alias(-help)
433 fhelp=
434 Common Driver Joined Alias(-help=)
436 ftarget-help
437 Common Driver Alias(-target-help)
439 fversion
440 Common Driver Alias(-version)
442 -sysroot
443 Driver Separate Alias(-sysroot=)
445 -sysroot=
446 Driver JoinedOrMissing
448 -version
449 Common Driver
452 Driver Joined Separate
455 Driver
458 Driver Joined Separate
461 Driver
464 Common JoinedOrMissing Optimization
465 -O<number>      Set optimization level to <number>.
468 Common Optimization
469 Optimize for space rather than speed.
471 Ofast
472 Common Optimization
473 Optimize for speed disregarding exact standards compliance.
476 Common Optimization
477 Optimize for debugging experience rather than speed or size.
480 Driver
483 Driver Negative(Qy)
486 Driver Negative(Qn)
489 Driver Joined Separate
492 Driver
495 Driver Joined Separate
497 Tbss
498 Driver Separate
500 Tbss=
501 Driver Joined
503 Tdata
504 Driver Separate
506 Tdata=
507 Driver Joined
509 Ttext
510 Driver Separate
512 Ttext=
513 Driver Joined
516 Common RejectNegative Warning Alias(Wextra)
517 This switch is deprecated; use -Wextra instead.
520 Driver JoinedOrMissing RejectNegative
523 Driver JoinedOrMissing RejectNegative
526 Driver JoinedOrMissing RejectNegative
528 Waggregate-return
529 Common Var(warn_aggregate_return) Warning
530 Warn about returning structures, unions or arrays.
532 Waggressive-loop-optimizations
533 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
534 Warn if a loop with constant number of iterations triggers undefined behavior.
536 Warray-bounds
537 Common Var(warn_array_bounds) Warning
538 Warn if an array is accessed out of bounds.
540 Warray-bounds=
541 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
542 Warn if an array is accessed out of bounds.
544 Wattributes
545 Common Var(warn_attributes) Init(1) Warning
546 Warn about inappropriate attribute usage.
548 Wattribute-alias
549 Common Alias(Wattribute_alias=, 1, 0) Warning
550 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
552 Wattribute-alias=
553 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
554 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
556 Wcannot-profile
557 Common Var(warn_cannot_profile) Init(1) Warning
558 Warn when profiling instrumentation was requested, but could not be applied to
559 a certain function.
561 Wcast-align
562 Common Var(warn_cast_align) Warning
563 Warn about pointer casts which increase alignment.
565 Wcast-align=strict
566 Common Var(warn_cast_align,2) Warning
567 Warn about pointer casts which increase alignment.
569 Wcpp
570 Common Var(warn_cpp) Init(1) Warning
571 Warn when a #warning directive is encountered.
573 Wattribute-warning
574 Common Var(warn_attribute_warning) Init(1) Warning
575 Warn about uses of __attribute__((warning)) declarations.
577 Wdeprecated
578 Common Var(warn_deprecated) Init(1) Warning
579 Warn if a deprecated compiler feature, class, method, or field is used.
581 Wdeprecated-declarations
582 Common Var(warn_deprecated_decl) Init(1) Warning
583 Warn about uses of __attribute__((deprecated)) declarations.
585 Wdisabled-optimization
586 Common Var(warn_disabled_optimization) Warning
587 Warn when an optimization pass is disabled.
589 Werror
590 Common Var(warnings_are_errors)
591 Treat all warnings as errors.
593 Werror=
594 Common Joined
595 Treat specified warning as error.
597 Wextra
598 Common Var(extra_warnings) Warning
599 Print extra (possibly unwanted) warnings.
601 Wfatal-errors
602 Common Var(flag_fatal_errors)
603 Exit on the first error occurred.
605 Wframe-larger-than=
606 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
607 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
609 Wno-frame-larger-than
610 Common Alias(Wframe-larger-than=,18446744073709551615EiB,none) Warning
611 Disable -Wframe-larger-than= warning.  Equivalent to -Wframe-larger-than=<SIZE_MAX> or larger.
613 Wfree-nonheap-object
614 Common Var(warn_free_nonheap_object) Init(1) Warning
615 Warn when attempting to free a non-heap object.
617 Whsa
618 Common Ignore Warning
619 Does nothing.  Preserved for backward compatibility.
621 Wimplicit-fallthrough
622 Common Alias(Wimplicit-fallthrough=,3,0) Warning
624 Wimplicit-fallthrough=
625 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
626 Warn when a switch case falls through.
628 Winline
629 Common Var(warn_inline) Warning Optimization
630 Warn when an inlined function cannot be inlined.
632 Winvalid-memory-model
633 Common Var(warn_invalid_memory_model) Init(1) Warning
634 Warn when an atomic memory model parameter is known to be outside the valid range.
636 Wlarger-than-
637 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
639 Wlarger-than=
640 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
641 -Wlarger-than=<byte-size>       Warn if an object's size exceeds <byte-size>.
643 Wno-larger-than
644 Common Alias(Wlarger-than=,18446744073709551615EiB,none) Warning
645 Disable -Wlarger-than= warning.  Equivalent to -Wlarger-than=<SIZE_MAX> or larger.
647 Wnonnull-compare
648 Var(warn_nonnull_compare) Warning
649 Warn if comparing pointer parameter with nonnull attribute with NULL.
651 Wnull-dereference
652 Common Var(warn_null_dereference) Warning
653 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
655 Wunsafe-loop-optimizations
656 Common Ignore Warning
657 Does nothing. Preserved for backward compatibility.
659 Wmissing-noreturn
660 Common Warning Alias(Wsuggest-attribute=noreturn)
662 Wodr
663 Common Var(warn_odr_violations) Init(1) Warning
664 Warn about some C++ One Definition Rule violations during link time optimization.
666 Woverflow
667 Common Var(warn_overflow) Init(1) Warning
668 Warn about overflow in arithmetic expressions.
670 Wlto-type-mismatch
671 Common Var(warn_lto_type_mismatch) Init(1) Warning
672 During link time optimization warn about mismatched types of global declarations.
674 Wpacked
675 Common Var(warn_packed) Warning
676 Warn when the packed attribute has no effect on struct layout.
678 Wpadded
679 Common Var(warn_padded) Warning
680 Warn when padding is required to align structure members.
682 Wpedantic
683 Common Var(pedantic) Init(0) Warning
684 Issue warnings needed for strict compliance to the standard.
686 Wreturn-local-addr
687 Common Var(warn_return_local_addr) Init(1) Warning
688 Warn about returning a pointer/reference to a local or temporary variable.
690 Wshadow
691 Common Var(warn_shadow) Warning
692 Warn when one variable shadows another.  Same as -Wshadow=global.
694 Wshadow=global
695 Common Warning Alias(Wshadow)
696 Warn when one variable shadows another (globally).
698 Wshadow=local
699 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
700 Warn when one local variable shadows another local variable or parameter.
702 Wshadow-local
703 Common Warning Undocumented Alias(Wshadow=local)
705 Wshadow=compatible-local
706 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
707 Warn when one local variable shadows another local variable or parameter of compatible type.
709 Wshadow-compatible-local
710 Common Warning Undocumented Alias(Wshadow=compatible-local)
712 Wstack-protector
713 Common Var(warn_stack_protect) Warning
714 Warn when not issuing stack smashing protection for some reason.
716 Wstack-usage=
717 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
718 -Wstack-usage=<byte-size>       Warn if stack usage might exceed <byte-size>.
720 Wno-stack-usage
721 Common Alias(Wstack-usage=,18446744073709551615EiB,none) Warning
722 Disable Wstack-usage= warning.  Equivalent to Wstack-usage=<SIZE_MAX> or larger.
724 Wstrict-aliasing
725 Common Warning
726 Warn about code which might break strict aliasing rules.
728 Wstrict-aliasing=
729 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
730 Warn about code which might break strict aliasing rules.
732 Wstrict-overflow
733 Common Warning
734 Warn about optimizations that assume that signed overflow is undefined.
736 Wstrict-overflow=
737 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
738 Warn about optimizations that assume that signed overflow is undefined.
740 Wsuggest-attribute=cold
741 Common Var(warn_suggest_attribute_cold) Warning
742 Warn about functions which might be candidates for __attribute__((cold)).
744 Wsuggest-attribute=const
745 Common Var(warn_suggest_attribute_const) Warning
746 Warn about functions which might be candidates for __attribute__((const)).
748 Wsuggest-attribute=pure
749 Common Var(warn_suggest_attribute_pure) Warning
750 Warn about functions which might be candidates for __attribute__((pure)).
752 Wsuggest-attribute=noreturn
753 Common Var(warn_suggest_attribute_noreturn) Warning
754 Warn about functions which might be candidates for __attribute__((noreturn)).
756 Wsuggest-attribute=malloc
757 Common Var(warn_suggest_attribute_malloc) Warning
758 Warn about functions which might be candidates for __attribute__((malloc)).
760 Wsuggest-final-types
761 Common Var(warn_suggest_final_types) Warning
762 Warn about C++ polymorphic types where adding final keyword would improve code quality.
764 Wsuggest-final-methods
765 Common Var(warn_suggest_final_methods) Warning
766 Warn about C++ virtual methods where adding final keyword would improve code quality.
768 Wswitch-unreachable
769 Common Var(warn_switch_unreachable) Warning Init(1)
770 Warn about statements between switch's controlling expression and the first
771 case.
773 Wsystem-headers
774 Common Var(warn_system_headers) Warning
775 Do not suppress warnings from system headers.
777 Wtrampolines
778 Common Var(warn_trampolines) Warning
779 Warn whenever a trampoline is generated.
781 Wtype-limits
782 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
783 Warn if a comparison is always true or always false due to the limited range of the data type.
785 Wuninitialized
786 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
787 Warn about uninitialized automatic variables.
789 Wmaybe-uninitialized
790 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
791 Warn about maybe uninitialized automatic variables.
793 Wunreachable-code
794 Common Ignore Warning
795 Does nothing. Preserved for backward compatibility.
797 Wunused
798 Common Var(warn_unused) Init(0) Warning
799 Enable all -Wunused- warnings.
801 Wunused-but-set-parameter
802 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
803 Warn when a function parameter is only set, otherwise unused.
805 Wunused-but-set-variable
806 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
807 Warn when a variable is only set, otherwise unused.
809 Wunused-function
810 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
811 Warn when a function is unused.
813 Wunused-label
814 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
815 Warn when a label is unused.
817 Wunused-parameter
818 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
819 Warn when a function parameter is unused.
821 Wunused-value
822 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
823 Warn when an expression value is unused.
825 Wunused-variable
826 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
827 Warn when a variable is unused.
829 Wcoverage-mismatch
830 Common Var(warn_coverage_mismatch) Init(1) Warning
831 Warn in case profiles in -fprofile-use do not match.
833 Wmissing-profile
834 Common Var(warn_missing_profile) Init(1) Warning
835 Warn in case profiles in -fprofile-use do not exist.
837 Wvector-operation-performance
838 Common Var(warn_vector_operation_performance) Warning
839 Warn when a vector operation is compiled outside the SIMD.
841 Xassembler
842 Driver Separate
844 Xlinker
845 Driver Separate
847 Xpreprocessor
848 Driver Separate
851 Driver
853 aux-info
854 Common Separate Var(aux_info_file_name)
855 -aux-info <file>        Emit declaration information into <file>.
857 aux-info=
858 Common Joined Alias(aux-info)
860 coverage
861 Driver
864 Driver
867 Common Joined
868 -d<letters>     Enable dumps from specific passes of the compiler.
870 dumpbase
871 Driver Common Separate Var(dump_base_name)
872 -dumpbase <file>        Set the file basename to be used for dumps.
874 dumpbase-ext
875 Driver Common Separate Var(dump_base_ext)
876 -dumpbase-ext .<ext>    Drop a trailing .<ext> from the dump basename to name auxiliary output files.
878 dumpdir
879 Driver Common Separate Var(dump_dir_name)
880 -dumpdir <dir>  Set the directory name to be used for dumps.
882 dumpmachine
883 Driver
885 dumpspecs
886 Driver
888 dumpversion
889 Driver
891 dumpfullversion
892 Driver
895 Driver Joined Separate
897 ; This option has historically been passed down to the linker by an
898 ; accident of a %{e*} spec, so ensure it continues to be passed down
899 ; as a single option.  The supported option for this purpose is
900 ; -rdynamic.  See PR 47390.
901 export-dynamic
902 Driver Undocumented
904 ; The version of the C++ ABI in use.  The following values are allowed:
906 ; 0: The version of the ABI believed most conformant with the C++ ABI
907 ;    specification.  This ABI may change as bugs are discovered and fixed.
908 ;    Therefore, 0 will not necessarily indicate the same ABI in different
909 ;    versions of G++.
911 ; 1: The version of the ABI first used in G++ 3.2.  No longer selectable.
913 ; 2: The version of the ABI first used in G++ 3.4, and the default
914 ;    until GCC 4.9.
916 ; 3: The version of the ABI that fixes the missing underscore
917 ;    in template non-type arguments of pointer type.
919 ; 4: The version of the ABI that introduces unambiguous mangling of
920 ;    vector types.  First selectable in G++ 4.5.
922 ; 5: The version of the ABI that ignores attribute const/noreturn
923 ;    in function pointer mangling, and corrects mangling of decltype and
924 ;    function parameters used in other parameters and the return type.
925 ;    First selectable in G++ 4.6.
927 ; 6: The version of the ABI that doesn't promote scoped enums to int and
928 ;    changes the mangling of template argument packs, const/static_cast,
929 ;    prefix ++ and --, and a class scope function used as a template
930 ;    argument.
931 ;    First selectable in G++ 4.7.
933 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
934 ;    corrects the mangling of lambdas in default argument scope.
935 ;    First selectable in G++ 4.8.
937 ; 8: The version of the ABI that corrects the substitution behavior of
938 ;    function types with function-cv-qualifiers.
939 ;    First selectable in G++ 4.9 and default in G++ 5.
941 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
942 ;    First selectable and default in G++ 5.2.
944 ; 10: The version of the ABI that mangles attributes that affect type
945 ;     identity, such as ia32 calling convention attributes (stdcall, etc.)
946 ;     Default in G++ 6 (set in c_common_post_options).
948 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
949 ;     and introduces new inheriting constructor handling.
950 ;     Default in G++ 7.
952 ; 12: Corrects the calling convention for classes with only deleted copy/move
953 ;     constructors and changes passing/returning of empty records.
954 ;     Default in G++ 8.1.
956 ; 13: Fixes the accidental change in 12 to the calling convention for classes
957 ;     with deleted copy constructor and trivial move constructor.
958 ;     Default in G++ 8.2.
959 ; 14: Corrects the mangling of nullptr expression.
960 ;     Default in G++ 10.
962 ; Additional positive integers will be assigned as new versions of
963 ; the ABI become the default version of the ABI.
964 fabi-version=
965 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
966 The version of the C++ ABI in use.
968 faggressive-loop-optimizations
969 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
970 Aggressively optimize loops using language constraints.
972 falign-functions
973 Common Report Var(flag_align_functions) Optimization
974 Align the start of functions.
976 falign-functions=
977 Common RejectNegative Joined Var(str_align_functions) Optimization
979 flimit-function-alignment
980 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
982 falign-jumps
983 Common Report Var(flag_align_jumps) Optimization
984 Align labels which are only reached by jumping.
986 falign-jumps=
987 Common RejectNegative Joined Var(str_align_jumps) Optimization
989 falign-labels
990 Common Report Var(flag_align_labels) Optimization
991 Align all labels.
993 falign-labels=
994 Common RejectNegative Joined Var(str_align_labels) Optimization
996 falign-loops
997 Common Report Var(flag_align_loops) Optimization
998 Align the start of loops.
1000 falign-loops=
1001 Common RejectNegative Joined Var(str_align_loops) Optimization
1003 fallow-store-data-races
1004 Common Report Var(flag_store_data_races) Optimization
1005 Allow the compiler to introduce new data races on stores.
1007 fanalyzer
1008 Common Var(flag_analyzer)
1009 Enable static analysis pass.
1011 fargument-alias
1012 Common Ignore
1013 Does nothing. Preserved for backward compatibility.
1015 fargument-noalias
1016 Common Ignore
1017 Does nothing. Preserved for backward compatibility.
1019 fargument-noalias-global
1020 Common Ignore
1021 Does nothing. Preserved for backward compatibility.
1023 fargument-noalias-anything
1024 Common Ignore
1025 Does nothing. Preserved for backward compatibility.
1027 fsanitize=
1028 Common Driver Report Joined
1029 Select what to sanitize.
1031 fsanitize-coverage=
1032 Common Report Joined
1033 Select type of coverage sanitization.
1035 fasan-shadow-offset=
1036 Common Joined RejectNegative Var(common_deferred_options) Defer
1037 -fasan-shadow-offset=<number>   Use custom shadow memory offset.
1039 fsanitize-sections=
1040 Common Joined RejectNegative Var(common_deferred_options) Defer
1041 -fsanitize-sections=<sec1,sec2,...>     Sanitize global variables
1042 in user-defined sections.
1044 fsanitize-recover=
1045 Common Report Joined
1046 After diagnosing undefined behavior attempt to continue execution.
1048 fsanitize-recover
1049 Common Report
1050 This switch is deprecated; use -fsanitize-recover= instead.
1052 fsanitize-address-use-after-scope
1053 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1055 fsanitize-undefined-trap-on-error
1056 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1057 Use trap instead of a library function for undefined behavior sanitization.
1059 fasynchronous-unwind-tables
1060 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1061 Generate unwind tables that are exact at each instruction boundary.
1063 fauto-inc-dec
1064 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1065 Generate auto-inc/dec instructions.
1067 fauto-profile
1068 Common Report Var(flag_auto_profile)
1069 Use sample profile information for call graph node weights. The default
1070 profile file is fbdata.afdo in 'pwd'.
1072 fauto-profile=
1073 Common Joined RejectNegative Var(auto_profile_file)
1074 Use sample profile information for call graph node weights. The profile
1075 file is specified in the argument.
1077 ; -fcheck-bounds causes gcc to generate array bounds checks.
1078 ; For C, C++ and ObjC: defaults off.
1079 ; For Java: defaults to on.
1080 ; For Fortran: defaults to off.
1081 fbounds-check
1082 Common Report Var(flag_bounds_check)
1083 Generate code to check bounds before indexing arrays.
1085 fbranch-count-reg
1086 Common Report Var(flag_branch_on_count_reg) Optimization
1087 Replace add, compare, branch with branch on count register.
1089 fbranch-probabilities
1090 Common Report Var(flag_branch_probabilities) Optimization
1091 Use profiling information for branch probabilities.
1093 fbranch-target-load-optimize
1094 Common Ignore
1095 Does nothing.  Preserved for backward compatibility.
1097 fbranch-target-load-optimize2
1098 Common Ignore
1099 Does nothing.  Preserved for backward compatibility.
1101 fbtr-bb-exclusive
1102 Common Ignore
1103 Does nothing.  Preserved for backward compatibility.
1105 fcallgraph-info
1106 Common Report RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1107 Output callgraph information on a per-file basis.
1109 fcallgraph-info=
1110 Common Report RejectNegative Joined
1111 Output callgraph information on a per-file basis with decorations.
1113 fcall-saved-
1114 Common Joined RejectNegative Var(common_deferred_options) Defer
1115 -fcall-saved-<register> Mark <register> as being preserved across functions.
1117 fcall-used-
1118 Common Joined RejectNegative Var(common_deferred_options) Defer
1119 -fcall-used-<register>  Mark <register> as being corrupted by function calls.
1121 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1122 ; be saved across function calls, if that produces overall better code.
1123 ; Optional now, so people can test it.
1124 fcaller-saves
1125 Common Report Var(flag_caller_saves) Optimization
1126 Save registers around function calls.
1128 fcheck-data-deps
1129 Common Ignore
1130 This switch is deprecated; do not use.
1132 fcheck-new
1133 Common Var(flag_check_new)
1134 Check the return value of new in C++.
1136 fchecking
1137 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1138 Perform internal consistency checkings.
1140 fchecking=
1141 Common Joined RejectNegative UInteger Var(flag_checking)
1142 Perform internal consistency checkings.
1144 fcode-hoisting
1145 Common Report Var(flag_code_hoisting) Optimization
1146 Enable code hoisting.
1148 fcombine-stack-adjustments
1149 Common Report Var(flag_combine_stack_adjustments) Optimization
1150 Looks for opportunities to reduce stack adjustments and stack references.
1152 fcommon
1153 Common Report Var(flag_no_common,0) Init(1)
1154 Put uninitialized globals in the common section.
1156 fcompare-debug
1157 Driver
1158 ; Converted by the driver to -fcompare-debug= options.
1160 fcompare-debug=
1161 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1162 -fcompare-debug[=<opts>]        Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1164 fcompare-debug-second
1165 Common Driver RejectNegative Var(flag_compare_debug)
1166 Run only the second compilation of -fcompare-debug.
1168 fcompare-elim
1169 Common Report Var(flag_compare_elim_after_reload) Optimization
1170 Perform comparison elimination after register allocation has finished.
1172 fconserve-stack
1173 Common Var(flag_conserve_stack) Optimization
1174 Do not perform optimizations increasing noticeably stack usage.
1176 fcprop-registers
1177 Common Report Var(flag_cprop_registers) Optimization
1178 Perform a register copy-propagation optimization pass.
1180 fcrossjumping
1181 Common Report Var(flag_crossjumping) Optimization
1182 Perform cross-jumping optimization.
1184 fcse-follow-jumps
1185 Common Report Var(flag_cse_follow_jumps) Optimization
1186 When running CSE, follow jumps to their targets.
1188 fcse-skip-blocks
1189 Common Ignore
1190 Does nothing.  Preserved for backward compatibility.
1192 fcx-limited-range
1193 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1194 Omit range reduction step when performing complex division.
1196 fcx-fortran-rules
1197 Common Report Var(flag_cx_fortran_rules) Optimization
1198 Complex multiplication and division follow Fortran rules.
1200 fdata-sections
1201 Common Report Var(flag_data_sections)
1202 Place data items into their own section.
1204 fdbg-cnt-list
1205 Common Report Var(flag_dbg_cnt_list)
1206 List all available debugging counters with their limits and counts.
1208 fdbg-cnt=
1209 Common RejectNegative Joined Var(common_deferred_options) Defer
1210 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1212 fdebug-prefix-map=
1213 Common Joined RejectNegative Var(common_deferred_options) Defer
1214 -fdebug-prefix-map=<old>=<new>  Map one directory name to another in debug information.
1216 ffile-prefix-map=
1217 Common Joined RejectNegative Var(common_deferred_options) Defer
1218 -ffile-prefix-map=<old>=<new>   Map one directory name to another in compilation result.
1220 fdebug-types-section
1221 Common Report Var(flag_debug_types_section) Init(0)
1222 Output .debug_types section when using DWARF v4 debuginfo.
1224 ; Nonzero for -fdefer-pop: don't pop args after each function call
1225 ; instead save them up to pop many calls' args with one insns.
1226 fdefer-pop
1227 Common Report Var(flag_defer_pop) Optimization
1228 Defer popping functions args from stack until later.
1230 fdelayed-branch
1231 Common Report Var(flag_delayed_branch) Optimization
1232 Attempt to fill delay slots of branch instructions.
1234 fdelete-dead-exceptions
1235 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1236 Delete dead instructions that may throw exceptions.
1238 fdelete-null-pointer-checks
1239 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1240 Delete useless null pointer checks.
1242 fdevirtualize-at-ltrans
1243 Common Report Var(flag_ltrans_devirtualize)
1244 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1246 fdevirtualize-speculatively
1247 Common Report Var(flag_devirtualize_speculatively) Optimization
1248 Perform speculative devirtualization.
1250 fdevirtualize
1251 Common Report Var(flag_devirtualize) Optimization
1252 Try to convert virtual calls to direct ones.
1254 fdiagnostics-show-location=
1255 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1256 -fdiagnostics-show-location=[once|every-line]   How often to emit source location at the beginning of line-wrapped diagnostics.
1258 ; Required for these enum values.
1259 SourceInclude
1260 pretty-print.h
1262 Enum
1263 Name(diagnostic_prefixing_rule) Type(int)
1265 EnumValue
1266 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1268 EnumValue
1269 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1271 fdiagnostics-show-caret
1272 Common Var(flag_diagnostics_show_caret) Init(1)
1273 Show the source line with a caret indicating the column.
1275 fdiagnostics-show-labels
1276 Common Var(flag_diagnostics_show_labels) Init(1)
1277 Show labels annotating ranges of source code when showing source.
1279 fdiagnostics-show-line-numbers
1280 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1281 Show line numbers in the left margin when showing source.
1283 fdiagnostics-color
1284 Common Alias(fdiagnostics-color=,always,never)
1287 fdiagnostics-color=
1288 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1289 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1291 ; Required for these enum values.
1292 SourceInclude
1293 diagnostic-color.h
1295 Enum
1296 Name(diagnostic_color_rule) Type(int)
1298 EnumValue
1299 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1301 EnumValue
1302 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1304 EnumValue
1305 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1307 fdiagnostics-urls=
1308 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1309 -fdiagnostics-urls=[never|always|auto]  Embed URLs in diagnostics.
1311 ; Required for these enum values.
1312 SourceInclude
1313 diagnostic-url.h
1315 Enum
1316 Name(diagnostic_url_rule) Type(int)
1318 EnumValue
1319 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1321 EnumValue
1322 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1324 EnumValue
1325 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1327 fdiagnostics-column-unit=
1328 Common Joined RejectNegative Enum(diagnostics_column_unit)
1329 -fdiagnostics-column-unit=[display|byte]        Select whether column numbers are output as display columns (default) or raw bytes.
1331 fdiagnostics-column-origin=
1332 Common Joined RejectNegative UInteger
1333 -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.
1335 fdiagnostics-format=
1336 Common Joined RejectNegative Enum(diagnostics_output_format)
1337 -fdiagnostics-format=[text|json]        Select output format.
1339 ; Required for these enum values.
1340 SourceInclude
1341 diagnostic.h
1343 Enum
1344 Name(diagnostics_column_unit) Type(int)
1346 EnumValue
1347 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1349 EnumValue
1350 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1352 Enum
1353 Name(diagnostics_output_format) Type(int)
1355 EnumValue
1356 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1358 EnumValue
1359 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1361 fdiagnostics-parseable-fixits
1362 Common Var(flag_diagnostics_parseable_fixits)
1363 Print fix-it hints in machine-readable form.
1365 fdiagnostics-generate-patch
1366 Common Var(flag_diagnostics_generate_patch)
1367 Print fix-it hints to stderr in unified diff format.
1369 fdiagnostics-show-option
1370 Common Var(flag_diagnostics_show_option) Init(1)
1371 Amend appropriate diagnostic messages with the command line option that controls them.
1373 fdiagnostics-show-cwe
1374 Common Var(flag_diagnostics_show_cwe) Init(1)
1375 Print CWE identifiers for diagnostic messages, where available.
1377 fdiagnostics-path-format=
1378 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1379 Specify how to print any control-flow path associated with a diagnostic.
1381 fdiagnostics-plain-output
1382 Driver Common RejectNegative
1383 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1385 ftabstop=
1386 Common Joined RejectNegative UInteger
1387 -ftabstop=<number>      Distance between tab stops for column reporting.
1389 Enum
1390 Name(diagnostic_path_format) Type(int)
1392 EnumValue
1393 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1395 EnumValue
1396 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1398 EnumValue
1399 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1401 fdiagnostics-show-path-depths
1402 Common Var(flag_diagnostics_show_path_depths) Init(0)
1403 Show stack depths of events in paths.
1405 fdiagnostics-minimum-margin-width=
1406 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1407 Set minimum width of left margin of source code when showing source.
1409 fdisable-
1410 Common Joined RejectNegative Var(common_deferred_options) Defer
1411 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2   Disable an optimization pass.
1413 fenable-
1414 Common Joined RejectNegative Var(common_deferred_options) Defer
1415 -fenable-[tree|rtl|ipa]-<pass>=range1+range2    Enable an optimization pass.
1417 fdump-
1418 Common Joined RejectNegative Var(common_deferred_options) Defer
1419 -fdump-<type>   Dump various compiler internals to a file.
1421 fdump-final-insns
1422 Driver RejectNegative
1424 fdump-final-insns=
1425 Common RejectNegative Joined Var(flag_dump_final_insns)
1426 -fdump-final-insns=filename     Dump to filename the insns at the end of translation.
1428 fdump-go-spec=
1429 Common RejectNegative Joined Var(flag_dump_go_spec)
1430 -fdump-go-spec=filename Write all declarations to file as Go code.
1432 fdump-noaddr
1433 Common Report Var(flag_dump_noaddr)
1434 Suppress output of addresses in debugging dumps.
1436 freport-bug
1437 Common Driver Var(flag_report_bug)
1438 Collect and dump debug information into temporary file if ICE in C/C++
1439 compiler occurred.
1441 fdump-internal-locations
1442 Common Var(flag_dump_locations) Init(0)
1443 Dump detailed information on GCC's internal representation of source code locations.
1445 fdump-passes
1446 Common Var(flag_dump_passes) Init(0)
1447 Dump optimization passes.
1449 fdump-unnumbered
1450 Common Report Var(flag_dump_unnumbered)
1451 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1453 fdump-unnumbered-links
1454 Common Report Var(flag_dump_unnumbered_links)
1455 Suppress output of previous and next insn numbers in debugging dumps.
1457 fdwarf2-cfi-asm
1458 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1459 Enable CFI tables via GAS assembler directives.
1461 fearly-inlining
1462 Common Report Var(flag_early_inlining) Init(1) Optimization
1463 Perform early inlining.
1465 feliminate-dwarf2-dups
1466 Common Ignore
1467 Does nothing.  Preserved for backward compatibility.
1469 fipa-sra
1470 Common Report Var(flag_ipa_sra) Init(0) Optimization
1471 Perform interprocedural reduction of aggregates.
1473 feliminate-unused-debug-symbols
1474 Common Report Var(flag_debug_only_used_symbols) Init(1)
1475 Perform unused symbol elimination in debug info.
1477 feliminate-unused-debug-types
1478 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1479 Perform unused type elimination in debug info.
1481 femit-class-debug-always
1482 Common Report Var(flag_emit_class_debug_always) Init(0)
1483 Do not suppress C++ class debug information.
1485 fexceptions
1486 Common Report Var(flag_exceptions) Optimization
1487 Enable exception handling.
1489 fexpensive-optimizations
1490 Common Report Var(flag_expensive_optimizations) Optimization
1491 Perform a number of minor, expensive optimizations.
1493 fexcess-precision=
1494 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1495 -fexcess-precision=[fast|standard]      Specify handling of excess floating-point precision.
1497 Enum
1498 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1500 EnumValue
1501 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1503 EnumValue
1504 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1506 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1507 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1508 fpermitted-flt-eval-methods=
1509 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1510 -fpermitted-flt-eval-methods=[c11|ts-18661]     Specify which values of FLT_EVAL_METHOD are permitted.
1512 Enum
1513 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)
1515 EnumValue
1516 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1518 EnumValue
1519 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1521 ffast-math
1522 Common Optimization
1524 ffat-lto-objects
1525 Common Var(flag_fat_lto_objects)
1526 Output lto objects containing both the intermediate language and binary output.
1528 ffinite-math-only
1529 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1530 Assume no NaNs or infinities are generated.
1532 ffinite-loops
1533 Common Report Var(flag_finite_loops) Optimization Init(0)
1534 Assume that loops with an exit will terminate and not loop indefinitely.
1536 ffixed-
1537 Common Joined RejectNegative Var(common_deferred_options) Defer
1538 -ffixed-<register>      Mark <register> as being unavailable to the compiler.
1540 ffloat-store
1541 Common Report Var(flag_float_store) Optimization
1542 Don't allocate floats and doubles in extended-precision registers.
1544 fforce-addr
1545 Common Ignore
1546 Does nothing.  Preserved for backward compatibility.
1548 fforward-propagate
1549 Common Report Var(flag_forward_propagate) Optimization
1550 Perform a forward propagation pass on RTL.
1552 ffp-contract=
1553 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1554 -ffp-contract=[off|on|fast]     Perform floating-point expression contraction.
1556 Enum
1557 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1559 EnumValue
1560 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1562 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1563 EnumValue
1564 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1566 EnumValue
1567 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1569 ffp-int-builtin-inexact
1570 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1571 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1573 ; Nonzero means don't put addresses of constant functions in registers.
1574 ; Used for compiling the Unix kernel, where strange substitutions are
1575 ; done on the assembly output.
1576 ffunction-cse
1577 Common Report Var(flag_no_function_cse,0) Optimization
1578 Allow function addresses to be held in registers.
1580 ffunction-sections
1581 Common Report Var(flag_function_sections)
1582 Place each function into its own section.
1584 fgcse
1585 Common Report Var(flag_gcse) Optimization
1586 Perform global common subexpression elimination.
1588 fgcse-lm
1589 Common Report Var(flag_gcse_lm) Init(1) Optimization
1590 Perform enhanced load motion during global common subexpression elimination.
1592 fgcse-sm
1593 Common Report Var(flag_gcse_sm) Init(0) Optimization
1594 Perform store motion after global common subexpression elimination.
1596 fgcse-las
1597 Common Report Var(flag_gcse_las) Init(0) Optimization
1598 Perform redundant load after store elimination in global common subexpression
1599 elimination.
1601 fgcse-after-reload
1602 Common Report Var(flag_gcse_after_reload) Optimization
1603 Perform global common subexpression elimination after register allocation has
1604 finished.
1606 Enum
1607 Name(dwarf_gnat_encodings) Type(int)
1609 EnumValue
1610 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1612 EnumValue
1613 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1615 EnumValue
1616 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1618 fgnat-encodings=
1619 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1620 -fgnat-encodings=[all|gdb|minimal]      Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1622 ; This option is not documented yet as its semantics will change.
1623 fgraphite
1624 Common Report Var(flag_graphite) Optimization
1625 Enable in and out of Graphite representation.
1627 fgraphite-identity
1628 Common Report Var(flag_graphite_identity) Optimization
1629 Enable Graphite Identity transformation.
1631 fhoist-adjacent-loads
1632 Common Report Var(flag_hoist_adjacent_loads) Optimization
1633 Enable hoisting adjacent loads to encourage generating conditional move
1634 instructions.
1636 fkeep-gc-roots-live
1637 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1638 ; Always keep a pointer to a live memory block
1640 flarge-source-files
1641 Common Report Var(flag_large_source_files) Init(0)
1642 Improve GCC's ability to track column numbers in large source files,
1643 at the expense of slower compilation.
1645 floop-parallelize-all
1646 Common Report Var(flag_loop_parallelize_all) Optimization
1647 Mark all loops as parallel.
1649 floop-strip-mine
1650 Common Alias(floop-nest-optimize)
1651 Enable loop nest transforms.  Same as -floop-nest-optimize.
1653 floop-interchange
1654 Common Report Var(flag_loop_interchange) Optimization
1655 Enable loop interchange on trees.
1657 floop-block
1658 Common Alias(floop-nest-optimize)
1659 Enable loop nest transforms.  Same as -floop-nest-optimize.
1661 floop-unroll-and-jam
1662 Common Report Var(flag_unroll_jam) Optimization
1663 Perform unroll-and-jam on loops.
1665 fgnu-tm
1666 Common Report Var(flag_tm)
1667 Enable support for GNU transactional memory.
1669 fgnu-unique
1670 Common Report Var(flag_gnu_unique) Init(1)
1671 Use STB_GNU_UNIQUE if supported by the assembler.
1673 floop-flatten
1674 Common Ignore
1675 Does nothing. Preserved for backward compatibility.
1677 floop-nest-optimize
1678 Common Report Var(flag_loop_nest_optimize) Optimization
1679 Enable the loop nest optimizer.
1681 fstrict-volatile-bitfields
1682 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1683 Force bitfield accesses to match their type width.
1685 fstore-merging
1686 Common Report Var(flag_store_merging) Optimization
1687 Merge adjacent stores.
1689 fguess-branch-probability
1690 Common Report Var(flag_guess_branch_prob) Optimization
1691 Enable guessing of branch probabilities.
1693 ; Nonzero means ignore `#ident' directives.  0 means handle them.
1694 ; Generate position-independent code for executables if possible
1695 ; On SVR4 targets, it also controls whether or not to emit a
1696 ; string identifying the compiler.
1697 fident
1698 Common Report Var(flag_no_ident,0)
1699 Process #ident directives.
1701 fif-conversion
1702 Common Report Var(flag_if_conversion) Optimization
1703 Perform conversion of conditional jumps to branchless equivalents.
1705 fif-conversion2
1706 Common Report Var(flag_if_conversion2) Optimization
1707 Perform conversion of conditional jumps to conditional execution.
1709 fstack-reuse=
1710 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1711 -fstack-reuse=[all|named_vars|none]     Set stack reuse level for local variables.
1713 Enum
1714 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1716 EnumValue
1717 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1719 EnumValue
1720 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1722 EnumValue
1723 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1725 ftree-loop-if-convert
1726 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1727 Convert conditional jumps in innermost loops to branchless equivalents.
1729 ftree-loop-if-convert-stores
1730 Common Ignore
1731 Does nothing. Preserved for backward compatibility.
1733 ; -finhibit-size-directive inhibits output of .size for ELF.
1734 ; This is used only for compiling crtstuff.c,
1735 ; and it may be extended to other effects
1736 ; needed for crtstuff.c on other systems.
1737 finhibit-size-directive
1738 Common Report Var(flag_inhibit_size_directive)
1739 Do not generate .size directives.
1741 findirect-inlining
1742 Common Report Var(flag_indirect_inlining) Optimization
1743 Perform indirect inlining.
1745 ; General flag to enable inlining.  Specifying -fno-inline will disable
1746 ; all inlining apart from always-inline functions.
1747 finline
1748 Common Report Var(flag_no_inline,0) Init(0) Optimization
1749 Enable inlining of function declared \"inline\", disabling disables all inlining.
1751 finline-small-functions
1752 Common Report Var(flag_inline_small_functions) Optimization
1753 Integrate functions into their callers when code size is known not to grow.
1755 finline-functions
1756 Common Report Var(flag_inline_functions) Optimization
1757 Integrate functions not declared \"inline\" into their callers when profitable.
1759 finline-functions-called-once
1760 Common Report Var(flag_inline_functions_called_once) Optimization
1761 Integrate functions only required by their single caller.
1763 finline-limit-
1764 Common RejectNegative Joined Alias(finline-limit=)
1766 finline-limit=
1767 Common RejectNegative Joined UInteger
1768 -finline-limit=<number> Limit the size of inlined functions to <number>.
1770 finline-atomics
1771 Common Report Var(flag_inline_atomics) Init(1) Optimization
1772 Inline __atomic operations when a lock free instruction sequence is available.
1774 fcf-protection
1775 Common RejectNegative Alias(fcf-protection=,full)
1777 fcf-protection=
1778 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1779 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
1780 instructions have valid targets.
1782 Enum
1783 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1785 EnumValue
1786 Enum(cf_protection_level) String(full) Value(CF_FULL)
1788 EnumValue
1789 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1791 EnumValue
1792 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1794 EnumValue
1795 Enum(cf_protection_level) String(check) Value(CF_CHECK)
1797 EnumValue
1798 Enum(cf_protection_level) String(none) Value(CF_NONE)
1800 finstrument-functions
1801 Common Report Var(flag_instrument_function_entry_exit)
1802 Instrument function entry and exit with profiling calls.
1804 finstrument-functions-exclude-function-list=
1805 Common RejectNegative Joined
1806 -finstrument-functions-exclude-function-list=name,...   Do not instrument listed functions.
1808 finstrument-functions-exclude-file-list=
1809 Common RejectNegative Joined
1810 -finstrument-functions-exclude-file-list=filename,...   Do not instrument functions listed in files.
1812 fipa-cp
1813 Common Report Var(flag_ipa_cp) Optimization
1814 Perform interprocedural constant propagation.
1816 fipa-cp-clone
1817 Common Report Var(flag_ipa_cp_clone) Optimization
1818 Perform cloning to make Interprocedural constant propagation stronger.
1820 fipa-cp-alignment
1821 Common Ignore
1822 Does nothing.  Preserved for backward compatibility.
1824 fipa-bit-cp
1825 Common Report Var(flag_ipa_bit_cp) Optimization
1826 Perform interprocedural bitwise constant propagation.
1828 fipa-modref
1829 Common Report Var(flag_ipa_modref) Optimization
1830 Perform interprocedural modref analysis.
1832 fipa-profile
1833 Common Report Var(flag_ipa_profile) Init(0) Optimization
1834 Perform interprocedural profile propagation.
1836 fipa-pta
1837 Common Report Var(flag_ipa_pta) Init(0) Optimization
1838 Perform interprocedural points-to analysis.
1840 fipa-pure-const
1841 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1842 Discover pure and const functions.
1844 fipa-icf
1845 Common Report Var(flag_ipa_icf) Optimization
1846 Perform Identical Code Folding for functions and read-only variables.
1848 fipa-icf-functions
1849 Common Report Var(flag_ipa_icf_functions) Optimization
1850 Perform Identical Code Folding for functions.
1852 fipa-icf-variables
1853 Common Report Var(flag_ipa_icf_variables) Optimization
1854 Perform Identical Code Folding for variables.
1856 fipa-reference
1857 Common Report Var(flag_ipa_reference) Init(0) Optimization
1858 Discover read-only and non addressable static variables.
1860 fipa-reference-addressable
1861 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1862 Discover read-only, write-only and non-addressable static variables.
1864 fipa-stack-alignment
1865 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1866 Reduce stack alignment on call sites if possible.
1868 fipa-matrix-reorg
1869 Common Ignore
1870 Does nothing. Preserved for backward compatibility.
1872 fipa-struct-reorg
1873 Common Ignore
1874 Does nothing. Preserved for backward compatibility.
1876 fipa-vrp
1877 Common Report Var(flag_ipa_vrp) Optimization
1878 Perform IPA Value Range Propagation.
1880 fira-algorithm=
1881 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1882 -fira-algorithm=[CB|priority]   Set the used IRA algorithm.
1884 Enum
1885 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1887 EnumValue
1888 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1890 EnumValue
1891 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1893 fira-region=
1894 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1895 -fira-region=[one|all|mixed]    Set regions for IRA.
1897 Enum
1898 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1900 EnumValue
1901 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1903 EnumValue
1904 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1906 EnumValue
1907 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1909 fira-hoist-pressure
1910 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1911 Use IRA based register pressure calculation
1912 in RTL hoist optimizations.
1914 fira-loop-pressure
1915 Common Report Var(flag_ira_loop_pressure) Optimization
1916 Use IRA based register pressure calculation
1917 in RTL loop optimizations.
1919 fira-share-save-slots
1920 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1921 Share slots for saving different hard registers.
1923 fira-share-spill-slots
1924 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1925 Share stack slots for spilled pseudo-registers.
1927 fira-verbose=
1928 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1929 -fira-verbose=<number>  Control IRA's level of diagnostic messages.
1931 fivopts
1932 Common Report Var(flag_ivopts) Init(1) Optimization
1933 Optimize induction variables on trees.
1935 fjump-tables
1936 Common Var(flag_jump_tables) Init(1) Optimization
1937 Use jump tables for sufficiently large switch statements.
1939 fkeep-inline-functions
1940 Common Report Var(flag_keep_inline_functions)
1941 Generate code for functions even if they are fully inlined.
1943 fkeep-static-functions
1944 Common Report Var(flag_keep_static_functions)
1945 Generate code for static functions even if they are never called.
1947 fkeep-static-consts
1948 Common Report Var(flag_keep_static_consts) Init(1)
1949 Emit static const variables even if they are not used.
1951 fleading-underscore
1952 Common Report Var(flag_leading_underscore) Init(-1)
1953 Give external symbols a leading underscore.
1955 floop-optimize
1956 Common Ignore
1957 Does nothing.  Preserved for backward compatibility.
1959 flra-remat
1960 Common Report Var(flag_lra_remat) Optimization
1961 Do CFG-sensitive rematerialization in LRA.
1963 flto
1964 Common
1965 Enable link-time optimization.
1967 flto=
1968 Common RejectNegative Joined Var(flag_lto)
1969 Link-time optimization with number of parallel jobs or jobserver.
1971 Enum
1972 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1974 EnumValue
1975 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1977 EnumValue
1978 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1980 EnumValue
1981 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1983 EnumValue
1984 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1986 EnumValue
1987 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1989 flto-partition=
1990 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1991 Specify the algorithm to partition symbols and vars at linktime.
1993 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1994 flto-compression-level=
1995 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
1996 -flto-compression-level=<number>        Use zlib/zstd compression level <number> for IL.
1998 flto-odr-type-merging
1999 Common Ignore
2000 Does nothing.  Preserved for backward compatibility.
2002 flto-report
2003 Common Report Var(flag_lto_report) Init(0)
2004 Report various link-time optimization statistics.
2006 flto-report-wpa
2007 Common Report Var(flag_lto_report_wpa) Init(0)
2008 Report various link-time optimization statistics for WPA only.
2010 fmath-errno
2011 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
2012 Set errno after built-in math functions.
2014 fmax-errors=
2015 Common Joined RejectNegative UInteger Var(flag_max_errors)
2016 -fmax-errors=<number>   Maximum number of errors to report.
2018 fmem-report
2019 Common Report Var(mem_report)
2020 Report on permanent memory allocation.
2022 fmem-report-wpa
2023 Common Report Var(mem_report_wpa)
2024 Report on permanent memory allocation in WPA only.
2026 ; This will attempt to merge constant section constants, if 1 only
2027 ; string constants and constants from constant pool, if 2 also constant
2028 ; variables.
2029 fmerge-all-constants
2030 Common Report Var(flag_merge_constants,2) Init(1)
2031 Attempt to merge identical constants and constant variables.
2033 fmerge-constants
2034 Common Report Var(flag_merge_constants,1)
2035 Attempt to merge identical constants across compilation units.
2037 fmerge-debug-strings
2038 Common Report Var(flag_merge_debug_strings) Init(1)
2039 Attempt to merge identical debug strings across compilation units.
2041 fmessage-length=
2042 Common RejectNegative Joined UInteger
2043 -fmessage-length=<number>       Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping.
2045 fmodulo-sched
2046 Common Report Var(flag_modulo_sched) Optimization
2047 Perform SMS based modulo scheduling before the first scheduling pass.
2049 fmodulo-sched-allow-regmoves
2050 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
2051 Perform SMS based modulo scheduling with register moves allowed.
2053 fmove-loop-invariants
2054 Common Report Var(flag_move_loop_invariants) Optimization
2055 Move loop invariant computations out of loops.
2057 fdce
2058 Common Var(flag_dce) Init(1) Optimization
2059 Use the RTL dead code elimination pass.
2061 fdse
2062 Common Var(flag_dse) Init(0) Optimization
2063 Use the RTL dead store elimination pass.
2065 freschedule-modulo-scheduled-loops
2066 Common Report Var(flag_resched_modulo_sched) Optimization
2067 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2069 fnon-call-exceptions
2070 Common Report Var(flag_non_call_exceptions) Optimization
2071 Support synchronous non-call exceptions.
2073 foffload=
2074 Common Driver Joined MissingArgError(options or targets missing after %qs)
2075 -foffload=<targets>=<options>   Specify offloading targets and options for them.
2077 foffload-abi=
2078 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
2079 -foffload-abi=[lp64|ilp32]      Set the ABI to use in an offload compiler.
2081 Enum
2082 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2084 EnumValue
2085 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2087 EnumValue
2088 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2090 fomit-frame-pointer
2091 Common Report Var(flag_omit_frame_pointer) Optimization
2092 When possible do not generate stack frames.
2094 fopt-info
2095 Common Report Var(flag_opt_info) Optimization
2096 Enable all optimization info dumps on stderr.
2098 fopt-info-
2099 Common Joined RejectNegative Var(common_deferred_options) Defer
2100 -fopt-info[-<type>=filename]    Dump compiler optimization details.
2102 fsave-optimization-record
2103 Common Report Var(flag_save_optimization_record) Optimization
2104 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2106 foptimize-register-move
2107 Common Ignore
2108 Does nothing. Preserved for backward compatibility.
2110 foptimize-sibling-calls
2111 Common Report Var(flag_optimize_sibling_calls) Optimization
2112 Optimize sibling and tail recursive calls.
2114 fpartial-inlining
2115 Common Report Var(flag_partial_inlining) Optimization
2116 Perform partial inlining.
2118 fpre-ipa-mem-report
2119 Common Report Var(pre_ipa_mem_report)
2120 Report on memory allocation before interprocedural optimization.
2122 fpost-ipa-mem-report
2123 Common Report Var(post_ipa_mem_report)
2124 Report on memory allocation before interprocedural optimization.
2126 fpack-struct
2127 Common Report Var(flag_pack_struct) Optimization
2128 Pack structure members together without holes.
2130 fpack-struct=
2131 Common RejectNegative Joined UInteger Optimization
2132 -fpack-struct=<number>  Set initial maximum structure member alignment.
2134 fpcc-struct-return
2135 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2136 Return small aggregates in memory, not registers.
2138 fpeel-loops
2139 Common Report Var(flag_peel_loops) Optimization
2140 Perform loop peeling.
2142 fpeephole
2143 Common Report Var(flag_no_peephole,0) Optimization
2144 Enable machine specific peephole optimizations.
2146 fpeephole2
2147 Common Report Var(flag_peephole2) Optimization
2148 Enable an RTL peephole pass before sched2.
2150 fPIC
2151 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2152 Generate position-independent code if possible (large mode).
2154 fPIE
2155 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2156 Generate position-independent code for executables if possible (large mode).
2158 fpic
2159 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2160 Generate position-independent code if possible (small mode).
2162 fpie
2163 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2164 Generate position-independent code for executables if possible (small mode).
2166 fplt
2167 Common Report Var(flag_plt) Init(1) Optimization
2168 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2170 fplugin=
2171 Common Joined RejectNegative Var(common_deferred_options) Defer
2172 Specify a plugin to load.
2174 fplugin-arg-
2175 Common Joined RejectNegative Var(common_deferred_options) Defer
2176 -fplugin-arg-<name>-<key>[=<value>]     Specify argument <key>=<value> for plugin <name>.
2178 fpredictive-commoning
2179 Common Report Var(flag_predictive_commoning) Optimization
2180 Run predictive commoning optimization.
2182 fprefetch-loop-arrays
2183 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2184 Generate prefetch instructions, if available, for arrays in loops.
2186 fprofile
2187 Common Report Var(profile_flag)
2188 Enable basic program profiling code.
2190 fprofile-abs-path
2191 Common Report Var(profile_abs_path_flag)
2192 Generate absolute source path names for gcov.
2194 fprofile-arcs
2195 Common Report Var(profile_arc_flag)
2196 Insert arc-based program profiling code.
2198 fprofile-dir=
2199 Common Joined RejectNegative Var(profile_data_prefix)
2200 Set the top-level directory for storing the profile data.
2201 The default is 'pwd'.
2203 fprofile-note=
2204 Common Joined RejectNegative Var(profile_note_location)
2205 Select the name for storing the profile note file.
2207 fprofile-correction
2208 Common Report Var(flag_profile_correction)
2209 Enable correction of flow inconsistent profile data input.
2211 fprofile-update=
2212 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2213 -fprofile-update=[single|atomic|prefer-atomic]  Set the profile update method.
2215 fprofile-filter-files=
2216 Common Joined RejectNegative Var(flag_profile_filter_files)
2217 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2219 fprofile-exclude-files=
2220 Common Joined RejectNegative Var(flag_profile_exclude_files)
2221 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2223 Enum
2224 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2226 EnumValue
2227 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2229 EnumValue
2230 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2232 EnumValue
2233 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2235 fprofile-reproducible
2236 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2237 -fprofile-reproducible=[serial|parallel-runs|multithreaded]     Control level of reproducibility of profile gathered by -fprofile-generate.
2239 Enum
2240 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2242 EnumValue
2243 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2245 EnumValue
2246 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2248 EnumValue
2249 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2251 fprofile-prefix-path=
2252 Common Joined RejectNegative Var(profile_prefix_path)
2253 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2255 fprofile-generate
2256 Common
2257 Enable common options for generating profile info for profile feedback directed optimizations.
2259 fprofile-generate=
2260 Common Joined RejectNegative
2261 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2263 fprofile-partial-training
2264 Common Report Var(flag_profile_partial_training) Optimization
2265 Do not assume that functions never executed during the train run are cold.
2267 fprofile-use
2268 Common Var(flag_profile_use)
2269 Enable common options for performing profile feedback directed optimizations.
2271 fprofile-use=
2272 Common Joined RejectNegative
2273 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2275 fprofile-values
2276 Common Report Var(flag_profile_values)
2277 Insert code to profile values of expressions.
2279 fprofile-report
2280 Common Report Var(profile_report)
2281 Report on consistency of profile.
2283 fprofile-reorder-functions
2284 Common Report Var(flag_profile_reorder_functions) Optimization
2285 Enable function reordering that improves code placement.
2287 fpatchable-function-entry=
2288 Common Joined Optimization
2289 Insert NOP instructions at each function entry.
2291 frandom-seed
2292 Common Var(common_deferred_options) Defer
2294 frandom-seed=
2295 Common Joined RejectNegative Var(common_deferred_options) Defer
2296 -frandom-seed=<string>  Make compile reproducible using <string>.
2298 ; This switch causes the command line that was used to create an
2299 ; object file to be recorded into the object file.  The exact format
2300 ; of this recording is target and binary file format dependent.
2301 ; It is related to the -fverbose-asm switch, but that switch only
2302 ; records information in the assembler output file as comments, so
2303 ; they never reach the object file.
2304 frecord-gcc-switches
2305 Common Report Var(flag_record_gcc_switches)
2306 Record gcc command line switches in the object file.
2308 freg-struct-return
2309 Common Report Var(flag_pcc_struct_return,0) Optimization
2310 Return small aggregates in registers.
2312 fregmove
2313 Common Ignore
2314 Does nothing. Preserved for backward compatibility.
2316 flifetime-dse
2317 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2318 Tell DSE that the storage for a C++ object is dead when the constructor
2319 starts and when the destructor finishes.
2321 flifetime-dse=
2322 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2324 flive-patching
2325 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2327 flive-patching=
2328 Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2329 -flive-patching=[inline-only-static|inline-clone]       Control IPA
2330 optimizations to provide a safe compilation for live-patching.  At the same
2331 time, provides multiple-level control on the enabled IPA optimizations.
2333 Enum
2334 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2336 EnumValue
2337 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2339 EnumValue
2340 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2342 fallocation-dce
2343 Common Report Var(flag_allocation_dce) Init(1) Optimization
2344 Tell DCE to remove unused C++ allocations.
2346 flive-range-shrinkage
2347 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2348 Relief of register pressure through live range shrinkage.
2350 frename-registers
2351 Common Report Var(flag_rename_registers) Init(2) Optimization
2352 Perform a register renaming optimization pass.
2354 fschedule-fusion
2355 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2356 Perform a target dependent instruction fusion optimization pass.
2358 freorder-blocks
2359 Common Report Var(flag_reorder_blocks) Optimization
2360 Reorder basic blocks to improve code placement.
2362 freorder-blocks-algorithm=
2363 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2364 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2366 Enum
2367 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2369 EnumValue
2370 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2372 EnumValue
2373 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2375 freorder-blocks-and-partition
2376 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2377 Reorder basic blocks and partition into hot and cold sections.
2379 freorder-functions
2380 Common Report Var(flag_reorder_functions) Optimization
2381 Reorder functions to improve code placement.
2383 frerun-cse-after-loop
2384 Common Report Var(flag_rerun_cse_after_loop) Optimization
2385 Add a common subexpression elimination pass after loop optimizations.
2387 frerun-loop-opt
2388 Common Ignore
2389 Does nothing.  Preserved for backward compatibility.
2391 frounding-math
2392 Common Report Var(flag_rounding_math) Optimization SetByCombined
2393 Disable optimizations that assume default FP rounding behavior.
2395 fsched-interblock
2396 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2397 Enable scheduling across basic blocks.
2399 fsched-pressure
2400 Common Report Var(flag_sched_pressure) Init(0) Optimization
2401 Enable register pressure sensitive insn scheduling.
2403 fsched-spec
2404 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2405 Allow speculative motion of non-loads.
2407 fsched-spec-load
2408 Common Report Var(flag_schedule_speculative_load) Optimization
2409 Allow speculative motion of some loads.
2411 fsched-spec-load-dangerous
2412 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2413 Allow speculative motion of more loads.
2415 fsched-verbose=
2416 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2417 -fsched-verbose=<number>        Set the verbosity level of the scheduler.
2419 fsched2-use-superblocks
2420 Common Report Var(flag_sched2_use_superblocks) Optimization
2421 If scheduling post reload, do superblock scheduling.
2423 fsched2-use-traces
2424 Common Ignore
2425 Does nothing.  Preserved for backward compatibility.
2427 fschedule-insns
2428 Common Report Var(flag_schedule_insns) Optimization
2429 Reschedule instructions before register allocation.
2431 fschedule-insns2
2432 Common Report Var(flag_schedule_insns_after_reload) Optimization
2433 Reschedule instructions after register allocation.
2435 ; This flag should be on when a target implements non-trivial
2436 ; scheduling hooks, maybe saving some information for its own sake.
2437 ; On IA64, for example, this is used for correct bundling.
2438 fselective-scheduling
2439 Common Report Var(flag_selective_scheduling) Optimization
2440 Schedule instructions using selective scheduling algorithm.
2442 fselective-scheduling2
2443 Common Report Var(flag_selective_scheduling2) Optimization
2444 Run selective scheduling after reload.
2446 fself-test=
2447 Common Undocumented Joined Var(flag_self_test)
2448 Run self-tests, using the given path to locate test files.
2450 fsel-sched-pipelining
2451 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2452 Perform software pipelining of inner loops during selective scheduling.
2454 fsel-sched-pipelining-outer-loops
2455 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2456 Perform software pipelining of outer loops during selective scheduling.
2458 fsel-sched-reschedule-pipelined
2459 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2460 Reschedule pipelined regions without pipelining.
2462 fsemantic-interposition
2463 Common Report Var(flag_semantic_interposition) Init(1)
2464 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2466 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2467 ; of stalled insns into the ready list.
2468 fsched-stalled-insns
2469 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2470 Allow premature scheduling of queued insns.
2472 fsched-stalled-insns=
2473 Common RejectNegative Joined UInteger Optimization
2474 -fsched-stalled-insns=<number>  Set number of queued insns that can be prematurely scheduled.
2476 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2477 ; be examined for a dependency on a stalled insn that is candidate for
2478 ; premature removal from the queue of stalled insns into the ready list (has
2479 ; an effect only if the flag 'sched_stalled_insns' is set).
2480 fsched-stalled-insns-dep
2481 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2482 Set dependence distance checking in premature scheduling of queued insns.
2484 fsched-stalled-insns-dep=
2485 Common RejectNegative Joined UInteger Optimization
2486 -fsched-stalled-insns-dep=<number>      Set dependence distance checking in premature scheduling of queued insns.
2488 fsched-group-heuristic
2489 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2490 Enable the group heuristic in the scheduler.
2492 fsched-critical-path-heuristic
2493 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2494 Enable the critical path heuristic in the scheduler.
2496 fsched-spec-insn-heuristic
2497 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2498 Enable the speculative instruction heuristic in the scheduler.
2500 fsched-rank-heuristic
2501 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2502 Enable the rank heuristic in the scheduler.
2504 fsched-last-insn-heuristic
2505 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2506 Enable the last instruction heuristic in the scheduler.
2508 fsched-dep-count-heuristic
2509 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2510 Enable the dependent count heuristic in the scheduler.
2512 fsection-anchors
2513 Common Report Var(flag_section_anchors) Optimization
2514 Access data in the same section from shared anchor points.
2516 fsee
2517 Common Ignore
2518 Does nothing.  Preserved for backward compatibility.
2520 fzee
2521 Common Ignore
2522 Does nothing.  Preserved for backward compatibility.
2524 free
2525 Common Report Var(flag_ree) Init(0) Optimization
2526 Turn on Redundant Extensions Elimination pass.
2528 fshow-column
2529 Common Report Var(flag_show_column) Init(1)
2530 Show column numbers in diagnostics, when available.  Default on.
2532 fshrink-wrap
2533 Common Report Var(flag_shrink_wrap) Optimization
2534 Emit function prologues only before parts of the function that need it,
2535 rather than at the top of the function.
2537 fshrink-wrap-separate
2538 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2539 Shrink-wrap parts of the prologue and epilogue separately.
2541 fsignaling-nans
2542 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2543 Disable optimizations observable by IEEE signaling NaNs.
2545 fsigned-zeros
2546 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2547 Disable floating point optimizations that ignore the IEEE signedness of zero.
2549 fsingle-precision-constant
2550 Common Report Var(flag_single_precision_constant) Optimization
2551 Convert floating point constants to single precision constants.
2553 fsplit-ivs-in-unroller
2554 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2555 Split lifetimes of induction variables when loops are unrolled.
2557 fsplit-stack
2558 Common Report Var(flag_split_stack) Init(-1)
2559 Generate discontiguous stack frames.
2561 fsplit-wide-types
2562 Common Report Var(flag_split_wide_types) Optimization
2563 Split wide types into independent registers.
2565 fsplit-wide-types-early
2566 Common Report Var(flag_split_wide_types_early) Optimization
2567 Split wide types into independent registers earlier.
2569 fssa-backprop
2570 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2571 Enable backward propagation of use properties at the SSA level.
2573 fssa-phiopt
2574 Common Report Var(flag_ssa_phiopt) Optimization
2575 Optimize conditional patterns using SSA PHI nodes.
2577 fstdarg-opt
2578 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2579 Optimize amount of stdarg registers saved to stack at start of function.
2581 fvariable-expansion-in-unroller
2582 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2583 Apply variable expansion when loops are unrolled.
2585 fstack-check=
2586 Common Report RejectNegative Joined Optimization
2587 -fstack-check=[no|generic|specific]     Insert stack checking code into the program.
2589 fstack-check
2590 Common Alias(fstack-check=, specific, no)
2591 Insert stack checking code into the program.  Same as -fstack-check=specific.
2593 fstack-clash-protection
2594 Common Report Var(flag_stack_clash_protection) Optimization
2595 Insert code to probe each page of stack space as it is allocated to protect
2596 from stack-clash style attacks.
2598 fstack-limit
2599 Common Var(common_deferred_options) Defer
2601 fstack-limit-register=
2602 Common RejectNegative Joined Var(common_deferred_options) Defer
2603 -fstack-limit-register=<register>       Trap if the stack goes past <register>.
2605 fstack-limit-symbol=
2606 Common RejectNegative Joined Var(common_deferred_options) Defer
2607 -fstack-limit-symbol=<name>     Trap if the stack goes past symbol <name>.
2609 fstack-protector
2610 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2611 Use propolice as a stack protection method.
2613 fstack-protector-all
2614 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2615 Use a stack protection method for every function.
2617 fstack-protector-strong
2618 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2619 Use a smart stack protection method for certain functions.
2621 fstack-protector-explicit
2622 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2623 Use stack protection method only for functions with the stack_protect attribute.
2625 fstack-usage
2626 Common RejectNegative Var(flag_stack_usage)
2627 Output stack usage information on a per-function basis.
2629 fstrength-reduce
2630 Common Ignore
2631 Does nothing.  Preserved for backward compatibility.
2633 ; Nonzero if we should do (language-dependent) alias analysis.
2634 ; Typically, this analysis will assume that expressions of certain
2635 ; types do not alias expressions of certain other types.  Only used
2636 ; if alias analysis (in general) is enabled.
2637 fstrict-aliasing
2638 Common Report Var(flag_strict_aliasing) Optimization
2639 Assume strict aliasing rules apply.
2641 fstrict-overflow
2642 Common Report
2643 Treat signed overflow as undefined.  Negated as -fwrapv -fwrapv-pointer.
2645 fsync-libcalls
2646 Common Report Var(flag_sync_libcalls) Init(1)
2647 Implement __atomic operations via libcalls to legacy __sync functions.
2649 fsyntax-only
2650 Common Report Var(flag_syntax_only)
2651 Check for syntax errors, then stop.
2653 ftest-coverage
2654 Common Report Var(flag_test_coverage)
2655 Create data files needed by \"gcov\".
2657 fthread-jumps
2658 Common Report Var(flag_thread_jumps) Optimization
2659 Perform jump threading optimizations.
2661 ftime-report
2662 Common Report Var(time_report)
2663 Report the time taken by each compiler pass.
2665 ftime-report-details
2666 Common Report Var(time_report_details)
2667 Record times taken by sub-phases separately.
2669 ftls-model=
2670 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2671 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]      Set the default thread-local storage code generation model.
2673 Enum
2674 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2676 EnumValue
2677 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2679 EnumValue
2680 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2682 EnumValue
2683 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2685 EnumValue
2686 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2688 ftoplevel-reorder
2689 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2690 Reorder top level functions, variables, and asms.
2692 ftracer
2693 Common Report Var(flag_tracer) Optimization
2694 Perform superblock formation via tail duplication.
2696 ftrampolines
2697 Common Report Var(flag_trampolines) Init(0)
2698 For targets that normally need trampolines for nested functions, always
2699 generate them instead of using descriptors.
2701 ; Zero means that floating-point math operations cannot generate a
2702 ; (user-visible) trap.  This is the case, for example, in nonstop
2703 ; IEEE 754 arithmetic.
2704 ftrapping-math
2705 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2706 Assume floating-point operations can trap.
2708 ftrapv
2709 Common Report Var(flag_trapv) Optimization
2710 Trap for signed overflow in addition, subtraction and multiplication.
2712 ftree-ccp
2713 Common Report Var(flag_tree_ccp) Optimization
2714 Enable SSA-CCP optimization on trees.
2716 ftree-bit-ccp
2717 Common Report Var(flag_tree_bit_ccp) Optimization
2718 Enable SSA-BIT-CCP optimization on trees.
2720 ftree-store-ccp
2721 Common Ignore
2722 Does nothing.  Preserved for backward compatibility.
2724 ftree-ch
2725 Common Report Var(flag_tree_ch) Optimization
2726 Enable loop header copying on trees.
2728 ftree-coalesce-inlined-vars
2729 Common Ignore RejectNegative
2730 Does nothing.  Preserved for backward compatibility.
2732 ftree-coalesce-vars
2733 Common Report Var(flag_tree_coalesce_vars) Optimization
2734 Enable SSA coalescing of user variables.
2736 ftree-copyrename
2737 Common Ignore
2738 Does nothing.  Preserved for backward compatibility.
2740 ftree-copy-prop
2741 Common Report Var(flag_tree_copy_prop) Optimization
2742 Enable copy propagation on trees.
2744 ftree-store-copy-prop
2745 Common Ignore
2746 Does nothing.  Preserved for backward compatibility.
2748 ftree-cselim
2749 Common Report Var(flag_tree_cselim) Init(2) Optimization
2750 Transform condition stores into unconditional ones.
2752 ftree-switch-conversion
2753 Common Report Var(flag_tree_switch_conversion) Optimization
2754 Perform conversions of switch initializations.
2756 ftree-dce
2757 Common Report Var(flag_tree_dce) Optimization
2758 Enable SSA dead code elimination optimization on trees.
2760 ftree-dominator-opts
2761 Common Report Var(flag_tree_dom) Optimization
2762 Enable dominator optimizations.
2764 ftree-tail-merge
2765 Common Report Var(flag_tree_tail_merge) Optimization
2766 Enable tail merging on trees.
2768 ftree-dse
2769 Common Report Var(flag_tree_dse) Optimization
2770 Enable dead store elimination.
2772 ftree-forwprop
2773 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2774 Enable forward propagation on trees.
2776 ftree-fre
2777 Common Report Var(flag_tree_fre) Optimization
2778 Enable Full Redundancy Elimination (FRE) on trees.
2780 foptimize-strlen
2781 Common Report Var(flag_optimize_strlen) Optimization
2782 Enable string length optimizations on trees.
2784 fisolate-erroneous-paths-dereference
2785 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2786 Detect paths that trigger erroneous or undefined behavior due to
2787 dereferencing a null pointer.  Isolate those paths from the main control
2788 flow and turn the statement with erroneous or undefined behavior into a trap.
2790 fisolate-erroneous-paths-attribute
2791 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2792 Detect paths that trigger erroneous or undefined behavior due to a null value
2793 being used in a way forbidden by a returns_nonnull or nonnull
2794 attribute.  Isolate those paths from the main control flow and turn the
2795 statement with erroneous or undefined behavior into a trap.
2797 ftree-loop-distribution
2798 Common Report Var(flag_tree_loop_distribution) Optimization
2799 Enable loop distribution on trees.
2801 ftree-loop-distribute-patterns
2802 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2803 Enable loop distribution for patterns transformed into a library call.
2805 ftree-loop-im
2806 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2807 Enable loop invariant motion on trees.
2809 ftree-loop-linear
2810 Common Alias(floop-nest-optimize)
2811 Enable loop nest transforms.  Same as -floop-nest-optimize.
2813 ftree-loop-ivcanon
2814 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2815 Create canonical induction variables in loops.
2817 ftree-loop-optimize
2818 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2819 Enable loop optimizations on tree level.
2821 ftree-parallelize-loops=
2822 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2823 -ftree-parallelize-loops=<number>       Enable automatic parallelization of loops.
2825 ftree-phiprop
2826 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2827 Enable hoisting loads from conditional pointers.
2829 ftree-pre
2830 Common Report Var(flag_tree_pre) Optimization
2831 Enable SSA-PRE optimization on trees.
2833 ftree-partial-pre
2834 Common Report Var(flag_tree_partial_pre) Optimization
2835 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2837 ftree-pta
2838 Common Report Var(flag_tree_pta) Optimization
2839 Perform function-local points-to analysis on trees.
2841 ftree-reassoc
2842 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2843 Enable reassociation on tree level.
2845 ftree-salias
2846 Common Ignore
2847 Does nothing.  Preserved for backward compatibility.
2849 ftree-sink
2850 Common Report Var(flag_tree_sink) Optimization
2851 Enable SSA code sinking on trees.
2853 ftree-slsr
2854 Common Report Var(flag_tree_slsr) Optimization
2855 Perform straight-line strength reduction.
2857 ftree-sra
2858 Common Report Var(flag_tree_sra) Optimization
2859 Perform scalar replacement of aggregates.
2861 ftree-ter
2862 Common Report Var(flag_tree_ter) Optimization
2863 Replace temporary expressions in the SSA->normal pass.
2865 ftree-lrs
2866 Common Report Var(flag_tree_live_range_split) Optimization
2867 Perform live range splitting during the SSA->normal pass.
2869 ftree-vrp
2870 Common Report Var(flag_tree_vrp) Init(0) Optimization
2871 Perform Value Range Propagation on trees.
2873 fsplit-paths
2874 Common Report Var(flag_split_paths) Init(0) Optimization
2875 Split paths leading to loop backedges.
2877 funconstrained-commons
2878 Common Var(flag_unconstrained_commons) Optimization
2879 Assume common declarations may be overridden with ones with a larger
2880 trailing array.
2882 funit-at-a-time
2883 Common Report Var(flag_unit_at_a_time) Init(1)
2884 Compile whole compilation unit at a time.
2886 funroll-loops
2887 Common Report Var(flag_unroll_loops) Optimization
2888 Perform loop unrolling when iteration count is known.
2890 funroll-all-loops
2891 Common Report Var(flag_unroll_all_loops) Optimization
2892 Perform loop unrolling for all loops.
2894 funroll-completely-grow-size
2895 Undocumented Var(flag_cunroll_grow_size) Optimization
2896 ; Internal undocumented flag, allow size growth during complete unrolling
2898 ; Nonzero means that loop optimizer may assume that the induction variables
2899 ; that control loops do not overflow and that the loops with nontrivial
2900 ; exit condition are not infinite
2901 funsafe-loop-optimizations
2902 Common Ignore
2903 Does nothing.  Preserved for backward compatibility.
2905 fassociative-math
2906 Common Report Var(flag_associative_math) SetByCombined Optimization
2907 Allow optimization for floating-point arithmetic which may change the
2908 result of the operation due to rounding.
2910 freciprocal-math
2911 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2912 Same as -fassociative-math for expressions which include division.
2914 ; Nonzero means that unsafe floating-point math optimizations are allowed
2915 ; for the sake of speed.  IEEE compliance is not guaranteed, and operations
2916 ; are allowed to assume that their arguments and results are "normal"
2917 ; (e.g., nonnegative for SQRT).
2918 funsafe-math-optimizations
2919 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2920 Allow math optimizations that may violate IEEE or ISO standards.
2922 funswitch-loops
2923 Common Report Var(flag_unswitch_loops) Optimization
2924 Perform loop unswitching.
2926 fsplit-loops
2927 Common Report Var(flag_split_loops) Optimization
2928 Perform loop splitting.
2930 fversion-loops-for-strides
2931 Common Report Var(flag_version_loops_for_strides) Optimization
2932 Version loops based on whether indices have a stride of one.
2934 funwind-tables
2935 Common Report Var(flag_unwind_tables) Optimization
2936 Just generate unwind tables for exception handling.
2938 fuse-ld=bfd
2939 Common Driver Negative(fuse-ld=gold)
2940 Use the bfd linker instead of the default linker.
2942 fuse-ld=gold
2943 Common Driver Negative(fuse-ld=bfd)
2944 Use the gold linker instead of the default linker.
2946 fuse-ld=lld
2947 Common Driver Negative(fuse-ld=lld)
2948 Use the lld LLVM linker instead of the default linker.
2950 fuse-linker-plugin
2951 Common Undocumented Var(flag_use_linker_plugin)
2953 ; Positive if we should track variables, negative if we should run
2954 ; the var-tracking pass only to discard debug annotations, zero if
2955 ; we're not to run it.  When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2956 ; will be set according to optimize, debug_info_level and debug_hooks
2957 ; in process_options ().
2958 fvar-tracking
2959 Common Report Var(flag_var_tracking) Init(2) PerFunction
2960 Perform variable tracking.
2962 ; Positive if we should track variables at assignments, negative if
2963 ; we should run the var-tracking pass only to discard debug
2964 ; annotations.  When flag_var_tracking_assignments ==
2965 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2966 fvar-tracking-assignments
2967 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2968 Perform variable tracking by annotating assignments.
2970 ; Nonzero if we should toggle flag_var_tracking_assignments after
2971 ; processing options and computing its default.  */
2972 fvar-tracking-assignments-toggle
2973 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2974 Toggle -fvar-tracking-assignments.
2976 ; Positive if we should track uninitialized variables, negative if
2977 ; we should run the var-tracking pass only to discard debug
2978 ; annotations.  When flag_var_tracking_uninit == AUTODETECT_VALUE it
2979 ; will be set according to flag_var_tracking.
2980 fvar-tracking-uninit
2981 Common Report Var(flag_var_tracking_uninit) PerFunction
2982 Perform variable tracking and also tag variables that are uninitialized.
2984 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2985 ftree-vectorize
2986 Common Report Optimization
2987 Enable vectorization on trees.
2989 ftree-vectorizer-verbose=
2990 Common Joined RejectNegative Ignore
2991 Does nothing.  Preserved for backward compatibility.
2993 ftree-loop-vectorize
2994 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2995 Enable loop vectorization on trees.
2997 ftree-slp-vectorize
2998 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2999 Enable basic block vectorization (SLP) on trees.
3001 fvect-cost-model=
3002 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3003 -fvect-cost-model=[unlimited|dynamic|cheap]     Specifies the cost model for vectorization.
3005 fsimd-cost-model=
3006 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3007 -fsimd-cost-model=[unlimited|dynamic|cheap]     Specifies the vectorization cost model for code marked with a simd directive.
3009 Enum
3010 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3012 EnumValue
3013 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3015 EnumValue
3016 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3018 EnumValue
3019 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3021 fvect-cost-model
3022 Common Alias(fvect-cost-model=,dynamic,unlimited)
3023 Enables the dynamic vectorizer cost model.  Preserved for backward compatibility.
3025 ftree-vect-loop-version
3026 Common Ignore
3027 Does nothing. Preserved for backward compatibility.
3029 ftree-scev-cprop
3030 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
3031 Enable copy propagation of scalar-evolution information.
3033 ; -fverbose-asm causes extra commentary information to be produced in
3034 ; the generated assembly code (to make it more readable).  This option
3035 ; is generally only of use to those who actually need to read the
3036 ; generated assembly code (perhaps while debugging the compiler itself).
3037 ; -fno-verbose-asm, the default, causes the extra information
3038 ; to not be added and is useful when comparing two assembler files.
3039 fverbose-asm
3040 Common Report Var(flag_verbose_asm)
3041 Add extra commentary to assembler output.
3043 fvisibility=
3044 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3045 -fvisibility=[default|internal|hidden|protected]        Set the default symbol visibility.
3047 Enum
3048 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3050 EnumValue
3051 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3053 EnumValue
3054 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3056 EnumValue
3057 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3059 EnumValue
3060 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3062 fvtable-verify=
3063 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3064 Validate vtable pointers before using them.
3066 Enum
3067 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3069 EnumValue
3070 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3072 EnumValue
3073 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3075 EnumValue
3076 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3078 fvtv-counts
3079 Common Var(flag_vtv_counts)
3080 Output vtable verification counters.
3082 fvtv-debug
3083 Common Var(flag_vtv_debug)
3084 Output vtable verification pointer sets information.
3086 fvpt
3087 Common Report Var(flag_value_profile_transformations) Optimization
3088 Use expression value profiles in optimizations.
3090 fweb
3091 Common Report Var(flag_web) Init(2) Optimization
3092 Construct webs and split unrelated uses of single variable.
3094 ftree-builtin-call-dce
3095 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
3096 Enable conditional dead code elimination for builtin calls.
3098 fwhole-program
3099 Common Report Var(flag_whole_program) Init(0)
3100 Perform whole program optimizations.
3102 fwrapv-pointer
3103 Common Report Var(flag_wrapv_pointer) Optimization
3104 Assume pointer overflow wraps around.
3106 fwrapv
3107 Common Report Var(flag_wrapv) Optimization
3108 Assume signed arithmetic overflow wraps around.
3110 fzero-initialized-in-bss
3111 Common Report Var(flag_zero_initialized_in_bss) Init(1)
3112 Put zero initialized data in the bss section.
3115 Common Driver RejectNegative JoinedOrMissing
3116 Generate debug information in default format.
3118 gas-loc-support
3119 Common Driver Var(dwarf2out_as_loc_support) Init(2)
3120 Assume assembler support for (DWARF2+) .loc directives.
3122 gas-locview-support
3123 Common Driver Var(dwarf2out_as_locview_support) Init(2)
3124 Assume assembler support for view in (DWARF2+) .loc directives.
3126 gcoff
3127 Common Driver WarnRemoved
3128 Does nothing.  Preserved for backward compatibility.
3130 gcoff1
3131 Common Driver WarnRemoved
3132 Does nothing.  Preserved for backward compatibility.
3134 gcoff2
3135 Common Driver WarnRemoved
3136 Does nothing.  Preserved for backward compatibility.
3138 gcoff3
3139 Common Driver WarnRemoved
3140 Does nothing.  Preserved for backward compatibility.
3142 gcolumn-info
3143 Common Driver Var(debug_column_info,1) Init(1)
3144 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3146 gdwarf
3147 Common Driver JoinedOrMissing Negative(gdwarf-)
3148 Generate debug information in default version of DWARF format.
3150 gdwarf-
3151 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
3152 Generate debug information in DWARF v2 (or later) format.
3154 ggdb
3155 Common Driver JoinedOrMissing
3156 Generate debug information in default extended format.
3158 ginline-points
3159 Common Driver Var(debug_inline_points) Init(2)
3160 Generate extended entry point information for inlined functions.
3162 ginternal-reset-location-views
3163 Common Driver Var(debug_internal_reset_location_views) Init(2)
3164 Compute locview reset points based on insn length estimates.
3166 gno-
3167 RejectNegative Joined Undocumented
3168 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3170 gno-pubnames
3171 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3172 Don't generate DWARF pubnames and pubtypes sections.
3174 gpubnames
3175 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3176 Generate DWARF pubnames and pubtypes sections.
3178 ggnu-pubnames
3179 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3180 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3182 grecord-gcc-switches
3183 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3184 Record gcc command line switches in DWARF DW_AT_producer.
3186 gsplit-dwarf
3187 Common Driver Var(dwarf_split_debug_info) Init(0)
3188 Generate debug information in separate .dwo files.
3190 gstabs
3191 Common Driver JoinedOrMissing Negative(gstabs+)
3192 Generate debug information in STABS format.
3194 gstabs+
3195 Common Driver JoinedOrMissing Negative(gvms)
3196 Generate debug information in extended STABS format.
3198 gstatement-frontiers
3199 Common Driver Var(debug_nonbind_markers_p) Init(2)
3200 Emit progressive recommended breakpoint locations.
3202 gstrict-dwarf
3203 Common Driver Report Var(dwarf_strict) Init(0)
3204 Don't emit DWARF additions beyond selected version.
3206 gdescribe-dies
3207 Common Driver Report Var(flag_describe_dies) Init(0)
3208 Add description attributes to some DWARF DIEs that have no name attribute.
3210 gtoggle
3211 Common Driver Report Var(flag_gtoggle)
3212 Toggle debug information generation.
3214 gvariable-location-views
3215 Common Driver Var(debug_variable_location_views, 1) Init(2)
3216 Augment variable location lists with progressive views.
3218 gvariable-location-views=incompat5
3219 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3221 gvms
3222 Common Driver JoinedOrMissing Negative(gxcoff)
3223 Generate debug information in VMS format.
3225 gxcoff
3226 Common Driver JoinedOrMissing Negative(gxcoff+)
3227 Generate debug information in XCOFF format.
3229 gxcoff+
3230 Common Driver JoinedOrMissing Negative(gdwarf)
3231 Generate debug information in extended XCOFF format.
3233 Enum
3234 Name(compressed_debug_sections) Type(int)
3236 ; Since -gz= is completely handled in specs, the values aren't used and we
3237 ; assign arbitrary constants.
3238 EnumValue
3239 Enum(compressed_debug_sections) String(none) Value(0)
3241 EnumValue
3242 Enum(compressed_debug_sections) String(zlib) Value(1)
3244 EnumValue
3245 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3248 Common Driver
3249 Generate compressed debug sections.
3252 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3253 -gz=<format>    Generate compressed debug sections in format <format>.
3256 Driver Joined Separate
3258 iplugindir=
3259 Common Joined Var(plugindir_string) Init(0)
3260 -iplugindir=<dir>       Set <dir> to be the default plugin directory.
3262 imultiarch
3263 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3264 -imultiarch <dir>       Set <dir> to be the multiarch include subdirectory.
3267 Driver Joined Separate
3270 Driver
3272 no-canonical-prefixes
3273 Driver
3275 nodefaultlibs
3276 Driver
3278 nostartfiles
3279 Driver
3281 nolibc
3282 Driver
3284 nostdlib
3285 Driver
3288 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3289 -o <file>       Place output into <file>.
3292 Common Var(profile_flag)
3293 Enable function profiling.
3295 pass-exit-codes
3296 Driver Var(pass_exit_codes)
3298 pedantic
3299 Common Alias(Wpedantic)
3301 pedantic-errors
3302 Common Var(flag_pedantic_errors)
3303 Like -pedantic but issue them as errors.
3306 Driver
3308 pipe
3309 Driver Var(use_pipes)
3311 print-file-name=
3312 Driver JoinedOrMissing Var(print_file_name)
3314 print-libgcc-file-name
3315 Driver
3317 print-multi-directory
3318 Driver Var(print_multi_directory)
3320 print-multi-lib
3321 Driver Var(print_multi_lib)
3323 print-multi-os-directory
3324 Driver Var(print_multi_os_directory)
3326 print-multiarch
3327 Driver Var(print_multiarch)
3329 print-prog-name=
3330 Driver JoinedOrMissing Var(print_prog_name)
3332 print-search-dirs
3333 Driver Var(print_search_dirs)
3335 print-sysroot
3336 Driver Var(print_sysroot)
3338 print-sysroot-headers-suffix
3339 Driver Var(print_sysroot_headers_suffix)
3341 quiet
3342 Common Var(quiet_flag) RejectDriver
3343 Do not display functions compiled or elapsed time.
3346 Driver
3349 Driver
3351 save-temps
3352 Driver
3354 save-temps=
3355 Driver Joined
3358 Driver
3360 time
3361 Driver Var(report_times)
3363 time=
3364 Driver JoinedOrMissing
3367 Driver Joined Separate
3369 undef
3370 Driver
3371 ; C option, but driver must not handle as "-u ndef".
3374 Common Driver Var(verbose_flag)
3375 Enable verbose output.
3377 version
3378 Common Var(version_flag) RejectDriver
3379 Display the compiler's version.
3382 Common Var(inhibit_warnings)
3383 Suppress warnings.
3385 wrapper
3386 Driver Separate Var(wrapper_string)
3389 Driver Joined Separate
3391 shared
3392 Driver RejectNegative Negative(static-pie)
3393 Create a shared library.
3395 shared-libgcc
3396 Driver
3398 specs
3399 Driver Separate Alias(specs=)
3401 specs=
3402 Driver Joined
3404 static
3405 Driver
3407 static-libgcc
3408 Driver
3410 static-libgfortran
3411 Driver
3412 ; Documented for Fortran, but always accepted by driver.
3414 static-libstdc++
3415 Driver
3417 static-libgo
3418 Driver
3419 ; Documented for Go, but always accepted by driver.
3421 static-libasan
3422 Driver
3424 static-libtsan
3425 Driver
3427 static-liblsan
3428 Driver
3430 static-libubsan
3431 Driver
3433 symbolic
3434 Driver
3436 no-pie
3437 Driver RejectNegative Negative(shared)
3438 Don't create a dynamically linked position independent executable.
3441 Driver RejectNegative Negative(no-pie)
3442 Create a dynamically linked position independent executable.
3444 static-pie
3445 Driver RejectNegative Negative(pie)
3446 Create a static position independent executable.
3449 Driver Joined Separate
3451 fipa-ra
3452 Common Report Var(flag_ipa_ra) Optimization
3453 Use caller save register across calls if possible.
3455 ; This comment is to ensure we retain the blank line above.