1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2024 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
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
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.
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
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.
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.
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.
60 int flag_complex_method = 1
63 int flag_default_complex_method = 1
65 ; Language specific warning pass for unused results.
67 bool flag_warn_unused_result = false
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
75 int flag_generate_offload = 0
77 ; Nonzero means we should be saving declaration info into a .X file.
79 int flag_gen_aux_info = 0
81 ; Nonzero if we are compiling code for a shared library, zero for
86 ; These three are really VEC(char_p,heap) *.
89 void *flag_instrument_functions_exclude_functions
92 void *flag_instrument_functions_exclude_files
95 void *flag_ignored_attributes
97 ; Generic structs (e.g. templates not explicitly specialized)
98 ; may not have a compilation unit associated with them, and so
99 ; may need to be treated differently from ordinary structs.
101 ; Structs only handled by reference (indirectly), will also usually
102 ; not need as much debugging information.
105 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
108 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
110 ; True if we should exit after parsing options.
112 bool exit_after_options
114 ; Type(s) of debugging information we are producing (if any). See
115 ; flag-types.h for the definitions of the different possible types of
116 ; debugging information.
118 uint32_t write_symbols = NO_DEBUG
120 ; Level of debugging information we are producing. See flag-types.h
121 ; for the definitions of the different possible levels.
123 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
125 ; Level of CTF debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum ctf_debug_info_levels ctf_debug_info_level = CTFINFO_LEVEL_NONE
130 ; Original value of maximum field alignment in bytes, specified via
131 ; -fpack-struct=<value>.
133 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
135 ; Type of stack check.
137 enum stack_check_type flag_stack_check = NO_STACK_CHECK
139 ; True if stack usage information needs to be computed.
141 bool flag_stack_usage_info = false
143 ; -dA causes debug commentary information to be produced in
144 ; the generated assembly code (to make it more readable). This option
145 ; is generally only of use to those who actually need to read the
146 ; generated assembly code (perhaps while debugging the compiler itself).
147 ; Currently, this switch is only used by dwarf2out.cc; however, it is intended
148 ; to be a catchall for printing debug information in the assembler file.
152 ; Balance between GNAT encodings and standard DWARF to emit.
154 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
156 ; -dP causes the rtl to be emitted as a comment in assembly.
158 int flag_dump_rtl_in_asm
160 ; Whether -da was passed (used only in handle_common_deferred_options).
162 bool flag_dump_all_passed
164 ; Other flags saying which kinds of debugging dump have been requested.
167 int rtl_dump_and_exit
170 int flag_print_asm_name
172 ; Name of top-level original source file (what was input to cpp).
173 ; This comes from the #-command at the beginning of the actual input.
174 ; If there isn't any there, then this is the cc1 input file name.
176 const char *main_input_filename
178 ; Pointer to base name in main_input_filename, with directories and a
179 ; single final extension removed, and the length of this base
183 const char *main_input_basename
186 int main_input_baselength
188 ; The base name used for auxiliary output files.
189 ; dump_base_name minus dump_base_ext.
192 const char *aux_base_name
194 ; Which options have been printed by --help.
198 ; Which enums have been printed by --help. 0 = not printed, no
199 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
202 char *help_enum_printed
204 ; The number of columns for --help output.
206 unsigned int help_columns
208 ; Whether this options structure has been through finish_options
210 bool flag_opts_finished
212 ; What the sanitizer should instrument
214 unsigned int flag_sanitize
216 ; What sanitizers should recover from errors
218 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS | SANITIZE_KERNEL_HWADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
220 ; What sanitizers should use __builtin_trap () instead of runtime diagnostics
222 unsigned int flag_sanitize_trap
224 ; Flag whether a prefix has been added to dump_base_name
226 bool dump_base_name_prefixed = false
228 ; What subset of registers should be zeroed on function return
230 unsigned int flag_zero_call_used_regs
242 Common Driver Joined Undocumented
243 Provide bash completion for options starting with provided string.
246 Driver Alias(coverage)
252 Common Separate Alias(d)
255 Common Joined Alias(d)
258 Driver Common Separate Alias(dumpbase)
261 Driver Common Separate Alias(dumpbase-ext)
264 Driver Common Separate Alias(dumpdir)
267 Driver Separate Alias(e)
270 Driver Joined Alias(e)
273 Common Warning Alias(Wextra)
276 Driver Separate Alias(Xassembler)
279 Driver JoinedOrMissing Alias(Xassembler)
282 Driver Separate Alias(Xlinker)
285 Driver JoinedOrMissing Alias(Xlinker)
288 Driver Separate Alias(u)
291 Driver Joined Alias(u)
294 Common Driver Var(help_flag)
295 Display this information.
299 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
302 Driver Separate Alias(x)
305 Driver Joined Alias(x)
308 Driver Separate Alias(L)
311 Driver Joined Alias(L)
313 -no-canonical-prefixes
314 Driver Alias(no-canonical-prefixes)
316 -no-standard-libraries
317 Driver Alias(nostdlib)
320 Driver Var(no_sysroot_suffix)
329 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
332 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
335 Driver Alias(pass-exit-codes)
338 Common Alias(Wpedantic)
341 Common Alias(pedantic-errors)
347 Driver Alias(static-pie)
353 Driver Separate Alias(B)
356 Driver JoinedOrMissing Alias(B)
362 Driver Separate Alias(print-file-name=)
365 Driver JoinedOrMissing Alias(print-file-name=)
367 -print-libgcc-file-name
368 Driver Alias(print-libgcc-file-name)
370 -print-multi-directory
371 Driver Alias(print-multi-directory)
374 Driver Alias(print-multi-lib)
376 -print-multi-os-directory
377 Driver Alias(print-multi-os-directory)
380 Driver Alias(print-multiarch)
383 Driver Separate Alias(print-prog-name=)
386 Driver JoinedOrMissing Alias(print-prog-name=)
389 Driver Alias(print-search-dirs)
392 Driver Alias(print-sysroot)
394 -print-sysroot-headers-suffix
395 Driver Alias(print-sysroot-headers-suffix)
401 Driver Alias(save-temps)
407 Driver Separate Alias(specs=)
410 Driver Joined Alias(specs=)
416 Driver Alias(symbolic)
420 Display target specific command line options (including assembler and linker options).
428 ;; The driver used to convert options such as --help into forms such
429 ;; as -fhelp; the following four entries are for compatibility with
430 ;; any direct uses of those (undocumented) -f forms
432 Common Driver Alias(-help)
435 Common Driver Joined Alias(-help=)
438 Common Driver Alias(-target-help)
441 Common Driver Alias(-version)
444 Driver Separate Alias(-sysroot=)
447 Driver JoinedOrMissing
453 Driver Joined Separate
459 Driver Joined Separate
465 Common JoinedOrMissing Optimization
466 -O<number> Set optimization level to <number>.
470 Optimize for space rather than speed.
474 Optimize for speed disregarding exact standards compliance.
478 Optimize for debugging experience rather than speed or size.
482 Optimize for space aggressively rather than speed.
494 Driver Joined Separate
500 Driver Joined Separate
521 Common RejectNegative Warning Alias(Wextra)
522 This switch is deprecated; use -Wextra instead.
525 Driver JoinedOrMissing RejectNegative
528 Driver JoinedOrMissing RejectNegative
531 Driver JoinedOrMissing RejectNegative
534 Common Var(warn_aggregate_return) Warning
535 Warn about returning structures, unions or arrays.
537 Waggressive-loop-optimizations
538 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
539 Warn if a loop with constant number of iterations triggers undefined behavior.
542 Common Alias(Warray-bounds=, 1, 0) Warning
545 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
546 Warn if an array is accessed out of bounds.
549 Common Var(warn_use_after_free) Warning
550 Warn for uses of pointers to deallocated storage.
553 Common Joined RejectNegative UInteger Var(warn_use_after_free) Warning IntegerRange(0, 3)
554 Warn for uses of pointers to deallocated storage.
557 Common Var(warn_attributes) Init(1) Warning
558 Warn about inappropriate attribute usage.
562 Do not warn about specified attributes.
565 Common Alias(Wattribute_alias=, 1, 0) Warning
566 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
569 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
570 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
573 Common Var(warn_cannot_profile) Init(1) Warning
574 Warn when profiling instrumentation was requested, but could not be applied to
578 Common Var(warn_cast_align) Warning
579 Warn about pointer casts which increase alignment.
582 Common Var(warn_cast_align,2) Warning
583 Warn about pointer casts which increase alignment.
586 Common Var(warn_complain_wrong_lang) Init(1) Warning
587 Complain when a command-line option is valid, but not applicable to the current front end.
590 Common Var(warn_cpp) Init(1) Warning
591 Warn when a #warning directive is encountered.
594 Common Var(warn_attribute_warning) Init(1) Warning
595 Warn about uses of __attribute__((warning)) declarations.
598 Common Var(warn_deprecated) Init(1) Warning
599 Warn if a deprecated compiler feature, class, method, or field is used.
601 Wdeprecated-declarations
602 Common Var(warn_deprecated_decl) Init(1) Warning
603 Warn about uses of __attribute__((deprecated)) declarations.
605 Wdisabled-optimization
606 Common Var(warn_disabled_optimization) Warning
607 Warn when an optimization pass is disabled.
610 Common Var(warnings_are_errors)
611 Treat all warnings as errors.
615 Treat specified warning as error.
618 Common Var(extra_warnings) Warning
619 Print extra (possibly unwanted) warnings.
622 Common Var(flag_fatal_errors)
623 Exit on the first error occurred.
626 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
627 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
629 Wno-frame-larger-than
630 Common Alias(Wframe-larger-than=,18446744073709551615EiB,none) Warning
631 Disable -Wframe-larger-than= warning. Equivalent to -Wframe-larger-than=<SIZE_MAX> or larger.
634 Common Var(warn_free_nonheap_object) Init(1) Warning
635 Warn when attempting to free a non-heap object.
638 Common Var(warn_hardened) Init(1) Warning
639 Warn when -fhardened did not enable an option from its set.
642 Common Ignore Warning
643 Does nothing. Preserved for backward compatibility.
645 Wimplicit-fallthrough
646 Common Alias(Wimplicit-fallthrough=,3,0) Warning
648 Wimplicit-fallthrough=
649 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
650 Warn when a switch case falls through.
653 Var(warn_infinite_recursion) Warning
654 Warn for infinitely recursive calls.
657 Common Var(warn_inline) Warning Optimization
658 Warn when an inlined function cannot be inlined.
660 Winvalid-memory-model
661 Common Var(warn_invalid_memory_model) Init(1) Warning
662 Warn when an atomic memory model parameter is known to be outside the valid range.
665 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
668 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
669 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
672 Common Alias(Wlarger-than=,18446744073709551615EiB,none) Warning
673 Disable -Wlarger-than= warning. Equivalent to -Wlarger-than=<SIZE_MAX> or larger.
676 Var(warn_nonnull_compare) Warning
677 Warn if comparing pointer parameter with nonnull attribute with NULL.
680 Common Var(warn_null_dereference) Warning
681 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
683 Wunsafe-loop-optimizations
684 Common Ignore Warning
685 Does nothing. Preserved for backward compatibility.
688 Common Warning Alias(Wsuggest-attribute=noreturn)
691 Common Var(warn_odr_violations) Init(1) Warning
692 Warn about some C++ One Definition Rule violations during link time optimization.
695 Common Var(warn_overflow) Init(1) Warning
696 Warn about overflow in arithmetic expressions.
699 Common Var(warn_lto_type_mismatch) Init(1) Warning
700 During link time optimization warn about mismatched types of global declarations.
703 Common Var(warn_packed) Warning
704 Warn when the packed attribute has no effect on struct layout.
707 Common Var(warn_padded) Warning
708 Warn when padding is required to align structure members.
711 Common Var(pedantic) Init(0) Warning
712 Issue warnings needed for strict compliance to the standard.
715 Common Var(warn_return_local_addr) Init(1) Warning
716 Warn about returning a pointer/reference to a local or temporary variable.
719 Common Var(warn_shadow) Warning
720 Warn when one variable shadows another. Same as -Wshadow=global.
723 Common Warning Alias(Wshadow)
724 Warn when one variable shadows another (globally).
727 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
728 Warn when one local variable shadows another local variable or parameter.
731 Common Warning Undocumented Alias(Wshadow=local)
733 Wshadow=compatible-local
734 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
735 Warn when one local variable shadows another local variable or parameter of compatible type.
737 Wshadow-compatible-local
738 Common Warning Undocumented Alias(Wshadow=compatible-local)
741 Common Var(warn_stack_protect) Warning
742 Warn when not issuing stack smashing protection for some reason.
745 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
746 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
749 Common Alias(Wstack-usage=,18446744073709551615EiB,none) Warning
750 Disable Wstack-usage= warning. Equivalent to Wstack-usage=<SIZE_MAX> or larger.
754 Warn about code which might break strict aliasing rules.
757 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
758 Warn about code which might break strict aliasing rules.
762 Warn about optimizations that assume that signed overflow is undefined.
765 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
766 Warn about optimizations that assume that signed overflow is undefined.
768 Wsuggest-attribute=cold
769 Common Var(warn_suggest_attribute_cold) Warning
770 Warn about functions which might be candidates for __attribute__((cold)).
772 Wsuggest-attribute=const
773 Common Var(warn_suggest_attribute_const) Warning
774 Warn about functions which might be candidates for __attribute__((const)).
776 Wsuggest-attribute=pure
777 Common Var(warn_suggest_attribute_pure) Warning
778 Warn about functions which might be candidates for __attribute__((pure)).
780 Wsuggest-attribute=noreturn
781 Common Var(warn_suggest_attribute_noreturn) Warning
782 Warn about functions which might be candidates for __attribute__((noreturn)).
784 Wsuggest-attribute=malloc
785 Common Var(warn_suggest_attribute_malloc) Warning
786 Warn about functions which might be candidates for __attribute__((malloc)).
788 Wsuggest-attribute=returns_nonnull
789 Common Var(warn_suggest_attribute_returns_nonnull) Warning
790 Warn about functions which might be candidates for __attribute__((returns_nonnull)).
793 Common Var(warn_suggest_final_types) Warning
794 Warn about C++ polymorphic types where adding final keyword would improve code quality.
796 Wsuggest-final-methods
797 Common Var(warn_suggest_final_methods) Warning
798 Warn about C++ virtual methods where adding final keyword would improve code quality.
801 Common Var(warn_switch_unreachable) Warning Init(1)
802 Warn about statements between switch's controlling expression and the first
806 Common Var(warn_system_headers) Warning
807 Do not suppress warnings from system headers.
810 Common Var(warn_trampolines) Warning
811 Warn whenever a trampoline is generated.
813 Wtrivial-auto-var-init
814 Common Var(warn_trivial_auto_var_init) Warning Init(0)
815 Warn about cases where -ftrivial-auto-var-init cannot initialize an auto variable.
818 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
819 Warn if a comparison is always true or always false due to the limited range of the data type.
822 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
823 Warn about uninitialized automatic variables.
826 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
827 Warn about maybe uninitialized automatic variables.
830 Common Ignore Warning
831 Does nothing. Preserved for backward compatibility.
834 Common Var(warn_unused) Init(0) Warning
835 Enable all -Wunused- warnings.
837 Wunused-but-set-parameter
838 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
839 Warn when a function parameter is only set, otherwise unused.
841 Wunused-but-set-variable
842 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
843 Warn when a variable is only set, otherwise unused.
846 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
847 Warn when a function is unused.
850 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
851 Warn when a label is unused.
854 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
855 Warn when a function parameter is unused.
858 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
859 Warn when an expression value is unused.
862 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
863 Warn when a variable is unused.
866 Common Var(warn_coverage_mismatch) Init(1) Warning
867 Warn in case profiles in -fprofile-use do not match.
869 Wcoverage-invalid-line-number
870 Common Var(warn_coverage_invalid_linenum) Init(1) Warning
871 Warn in case a function ends earlier than it begins due to an invalid linenum macros.
873 Wcoverage-too-many-conditions
874 Common Var(warn_too_many_conditions) Init(1) Warning
875 Warn when a conditional has too many terms and condition coverage profiling
876 gives up instrumenting the expression.
879 Common Var(warn_missing_profile) Init(1) Warning
880 Warn in case profiles in -fprofile-use do not exist.
882 Wvector-operation-performance
883 Common Var(warn_vector_operation_performance) Warning
884 Warn when a vector operation is compiled outside the SIMD.
887 Common Var(warn_tsan) Init(1) Warning
888 Warn about unsupported features in ThreadSanitizer.
903 Common Separate Var(aux_info_file_name)
904 -aux-info <file> Emit declaration information into <file>.
907 Common Joined Alias(aux-info)
917 -d<letters> Enable dumps from specific passes of the compiler.
920 Driver Common Separate Var(dump_base_name)
921 -dumpbase <file> Set the file basename to be used for dumps.
924 Driver Common Separate Var(dump_base_ext)
925 -dumpbase-ext .<ext> Drop a trailing .<ext> from the dump basename to name auxiliary output files.
928 Driver Common Separate Var(dump_dir_name)
929 -dumpdir <dir> Set the directory name to be used for dumps.
944 Driver Joined Separate
946 ; This option has historically been passed down to the linker by an
947 ; accident of a %{e*} spec, so ensure it continues to be passed down
948 ; as a single option. The supported option for this purpose is
949 ; -rdynamic. See PR 47390.
953 ; The version of the C++ ABI in use. The following values are allowed:
955 ; 0: The version of the ABI believed most conformant with the C++ ABI
956 ; specification. This ABI may change as bugs are discovered and fixed.
957 ; Therefore, 0 will not necessarily indicate the same ABI in different
960 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
962 ; 2: The version of the ABI first used in G++ 3.4, and the default
965 ; 3: The version of the ABI that fixes the missing underscore
966 ; in template non-type arguments of pointer type.
968 ; 4: The version of the ABI that introduces unambiguous mangling of
969 ; vector types. First selectable in G++ 4.5.
971 ; 5: The version of the ABI that ignores attribute const/noreturn
972 ; in function pointer mangling, and corrects mangling of decltype and
973 ; function parameters used in other parameters and the return type.
974 ; First selectable in G++ 4.6.
976 ; 6: The version of the ABI that doesn't promote scoped enums to int and
977 ; changes the mangling of template argument packs, const/static_cast,
978 ; prefix ++ and --, and a class scope function used as a template
980 ; First selectable in G++ 4.7.
982 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
983 ; corrects the mangling of lambdas in default argument scope.
984 ; First selectable in G++ 4.8.
986 ; 8: The version of the ABI that corrects the substitution behavior of
987 ; function types with function-cv-qualifiers.
988 ; First selectable in G++ 4.9 and default in G++ 5.
990 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
991 ; First selectable and default in G++ 5.2.
993 ; 10: The version of the ABI that mangles attributes that affect type
994 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
995 ; Default in G++ 6 (set in c_common_post_options).
997 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
998 ; and introduces new inheriting constructor handling.
1001 ; 12: Corrects the calling convention for classes with only deleted copy/move
1002 ; constructors and changes passing/returning of empty records.
1003 ; Default in G++ 8.1.
1005 ; 13: Fixes the accidental change in 12 to the calling convention for classes
1006 ; with deleted copy constructor and trivial move constructor.
1007 ; Default in G++ 8.2.
1009 ; 14: Corrects the mangling of nullptr expression.
1010 ; Default in G++ 10.
1012 ; 15: Corrects G++ 10 ABI tag regression [PR98481].
1013 ; Available, but not default, in G++ 10.3.
1015 ; 16: Changes the mangling of __alignof__ to be distinct from that of alignof.
1016 ; Adds missing 'on' in mangling of operator names in some cases.
1017 ; Default in G++ 11.
1019 ; 17: Fixes layout of classes that inherit from aggregate classes with default
1020 ; member initializers in C++14 and up.
1021 ; Default in G++ 12.
1023 ; 18: Corrects errors in mangling of lambdas with additional context.
1024 ; Default in G++ 13.
1026 ; 19: Emits ABI tags if needed in structured binding mangled names.
1027 ; Ignores cv-quals on [[no_unique_object]] members.
1028 ; Mangles constraints on function templates.
1029 ; Default in G++ 14.
1031 ; Additional positive integers will be assigned as new versions of
1032 ; the ABI become the default version of the ABI.
1034 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1035 The version of the C++ ABI in use.
1037 faggressive-loop-optimizations
1038 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1039 Aggressively optimize loops using language constraints.
1042 Common Var(flag_align_functions) Optimization
1043 Align the start of functions.
1046 Common RejectNegative Joined Var(str_align_functions) Optimization
1049 Common Var(flag_align_jumps) Optimization
1050 Align labels which are only reached by jumping.
1053 Common RejectNegative Joined Var(str_align_jumps) Optimization
1056 Common Var(flag_align_labels) Optimization
1060 Common RejectNegative Joined Var(str_align_labels) Optimization
1063 Common Var(flag_align_loops) Optimization
1064 Align the start of loops.
1067 Common RejectNegative Joined Var(str_align_loops) Optimization
1069 fallow-store-data-races
1070 Common Var(flag_store_data_races) Optimization
1071 Allow the compiler to introduce new data races on stores.
1074 Common Var(flag_analyzer)
1075 Enable static analysis pass.
1079 Does nothing. Preserved for backward compatibility.
1083 Does nothing. Preserved for backward compatibility.
1085 fargument-noalias-global
1087 Does nothing. Preserved for backward compatibility.
1089 fargument-noalias-anything
1091 Does nothing. Preserved for backward compatibility.
1094 Common Driver Joined
1095 Select what to sanitize.
1098 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1099 Select type of coverage sanitization.
1102 Name(sanitize_coverage) Type(int)
1105 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1108 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1110 fasan-shadow-offset=
1111 Common Joined RejectNegative Var(common_deferred_options) Defer
1112 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1115 Common Joined RejectNegative Var(common_deferred_options) Defer
1116 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1117 in user-defined sections.
1121 After diagnosing undefined behavior attempt to continue execution.
1125 This switch is deprecated; use -fsanitize-recover= instead.
1128 Common Driver Joined
1129 Use traps instead of diagnostics of undefined behavior sanitizers.
1134 fsanitize-address-use-after-scope
1135 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1137 fsanitize-undefined-trap-on-error
1138 Common Driver Alias(fsanitize-trap)
1139 This switch is deprecated; use -fsanitize-trap= instead.
1141 fasynchronous-unwind-tables
1142 Common Var(flag_asynchronous_unwind_tables) Optimization
1143 Generate unwind tables that are exact at each instruction boundary.
1146 Common Var(flag_auto_inc_dec) Init(1) Optimization
1147 Generate auto-inc/dec instructions.
1150 Common Var(flag_auto_profile)
1151 Use sample profile information for call graph node weights. The default
1152 profile file is fbdata.afdo in 'pwd'.
1155 Common Joined RejectNegative Var(auto_profile_file)
1156 Use sample profile information for call graph node weights. The profile
1157 file is specified in the argument.
1159 ; -fcheck-bounds causes gcc to generate array bounds checks.
1160 ; For C, C++ and ObjC: defaults off.
1161 ; For Java: defaults to on.
1162 ; For Fortran: defaults to off.
1164 Common Var(flag_bounds_check)
1165 Generate code to check bounds before indexing arrays.
1168 Common Var(flag_branch_on_count_reg) Optimization
1169 Replace add, compare, branch with branch on count register.
1171 fbranch-probabilities
1172 Common Var(flag_branch_probabilities) Optimization
1173 Use profiling information for branch probabilities.
1175 fbranch-target-load-optimize
1177 Does nothing. Preserved for backward compatibility.
1179 fbranch-target-load-optimize2
1181 Does nothing. Preserved for backward compatibility.
1185 Does nothing. Preserved for backward compatibility.
1188 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1189 Output callgraph information on a per-file basis.
1192 Common RejectNegative Joined
1193 Output callgraph information on a per-file basis with decorations.
1196 Common Joined RejectNegative Var(common_deferred_options) Defer
1197 -fcall-saved-<register> Mark <register> as being preserved across functions.
1200 Common Joined RejectNegative Var(common_deferred_options) Defer
1201 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1203 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1204 ; be saved across function calls, if that produces overall better code.
1205 ; Optional now, so people can test it.
1207 Common Var(flag_caller_saves) Optimization
1208 Save registers around function calls.
1212 This switch is deprecated; do not use.
1215 Common Var(flag_check_new)
1216 Check the return value of new in C++.
1219 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1220 Perform internal consistency checkings.
1223 Common Joined RejectNegative UInteger Var(flag_checking)
1224 Perform internal consistency checkings.
1227 Common Var(common_deferred_options) Defer
1228 For -f*-prefix-map= options compare canonicalized pathnames rather than just strings.
1231 Common Var(flag_code_hoisting) Optimization
1232 Enable code hoisting.
1234 fcombine-stack-adjustments
1235 Common Var(flag_combine_stack_adjustments) Optimization
1236 Looks for opportunities to reduce stack adjustments and stack references.
1239 Common Var(flag_no_common,0) Init(1)
1240 Put uninitialized globals in the common section.
1244 ; Converted by the driver to -fcompare-debug= options.
1247 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1248 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1250 fcompare-debug-second
1251 Common Driver RejectNegative Var(flag_compare_debug)
1252 Run only the second compilation of -fcompare-debug.
1255 Common Var(flag_compare_elim_after_reload) Optimization
1256 Perform comparison elimination after register allocation has finished.
1259 Common Var(flag_conserve_stack) Optimization
1260 Do not perform optimizations increasing noticeably stack usage.
1263 Common Var(flag_cprop_registers) Optimization
1264 Perform a register copy-propagation optimization pass.
1267 Common Var(flag_fold_mem_offsets) Init(1) Optimization
1268 Fold instructions calculating memory offsets to the memory access instruction if possible.
1271 Common Var(flag_crossjumping) Optimization
1272 Perform cross-jumping optimization.
1275 Common Var(flag_cse_follow_jumps) Optimization
1276 When running CSE, follow jumps to their targets.
1280 Does nothing. Preserved for backward compatibility.
1283 Common Var(flag_cx_limited_range) Optimization SetByCombined
1284 Omit range reduction step when performing complex division.
1287 Common Var(flag_cx_fortran_rules) Optimization
1288 Complex multiplication and division follow Fortran rules.
1291 Common Var(flag_data_sections)
1292 Place data items into their own section.
1295 Common Var(flag_dbg_cnt_list)
1296 List all available debugging counters with their limits and counts.
1299 Common RejectNegative Joined Var(common_deferred_options) Defer
1300 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1303 Common Joined RejectNegative Var(common_deferred_options) Defer
1304 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1307 Common Joined RejectNegative Var(common_deferred_options) Defer
1308 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1310 fdebug-types-section
1311 Common Var(flag_debug_types_section) Init(0)
1312 Output .debug_types section when using DWARF v4 debuginfo.
1314 ; Nonzero for -fdefer-pop: don't pop args after each function call
1315 ; instead save them up to pop many calls' args with one insns.
1317 Common Var(flag_defer_pop) Optimization
1318 Defer popping functions args from stack until later.
1321 Common Var(flag_delayed_branch) Optimization
1322 Attempt to fill delay slots of branch instructions.
1324 fdelete-dead-exceptions
1325 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1326 Delete dead instructions that may throw exceptions.
1328 fdelete-null-pointer-checks
1329 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1330 Delete useless null pointer checks.
1332 fdevirtualize-at-ltrans
1333 Common Var(flag_ltrans_devirtualize)
1334 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1336 fdevirtualize-speculatively
1337 Common Var(flag_devirtualize_speculatively) Optimization
1338 Perform speculative devirtualization.
1341 Common Var(flag_devirtualize) Optimization
1342 Try to convert virtual calls to direct ones.
1344 fdiagnostics-show-location=
1345 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1346 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1348 ; Required for these enum values.
1353 Name(diagnostic_prefixing_rule) Type(int)
1356 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1359 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1361 fdiagnostics-show-caret
1362 Common Var(flag_diagnostics_show_caret) Init(1)
1363 Show the source line with a caret indicating the column.
1365 fdiagnostics-show-labels
1366 Common Var(flag_diagnostics_show_labels) Init(1)
1367 Show labels annotating ranges of source code when showing source.
1369 fdiagnostics-show-line-numbers
1370 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1371 Show line numbers in the left margin when showing source.
1374 Common Alias(fdiagnostics-color=,always,never)
1378 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1379 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1381 ; Required for these enum values.
1386 Name(diagnostic_color_rule) Type(int)
1389 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1392 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1395 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1397 fdiagnostics-json-formatting
1398 Common Var(flag_diagnostics_json_formatting) Init(1)
1399 Enable formatting of JSON output.
1402 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1403 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1405 ; Required for these enum values.
1410 Name(diagnostic_url_rule) Type(int)
1413 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1416 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1419 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1421 fdiagnostics-column-unit=
1422 Common Joined RejectNegative Enum(diagnostics_column_unit)
1423 -fdiagnostics-column-unit=[display|byte] Select whether column numbers are output as display columns (default) or raw bytes.
1425 fdiagnostics-column-origin=
1426 Common Joined RejectNegative UInteger
1427 -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.
1429 fdiagnostics-format=
1430 Common Joined RejectNegative Enum(diagnostics_output_format)
1431 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file] Select output format.
1433 fdiagnostics-escape-format=
1434 Common Joined RejectNegative Enum(diagnostics_escape_format)
1435 -fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1437 ; Required for these enum values.
1442 Name(diagnostics_column_unit) Type(int)
1445 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1448 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1451 Name(diagnostics_escape_format) Type(int)
1454 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1457 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1460 Name(diagnostics_output_format) Type(int)
1463 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1466 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1469 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1472 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1475 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1478 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1480 fdiagnostics-parseable-fixits
1481 Common Var(flag_diagnostics_parseable_fixits)
1482 Print fix-it hints in machine-readable form.
1484 fdiagnostics-generate-patch
1485 Common Var(flag_diagnostics_generate_patch)
1486 Print fix-it hints to stderr in unified diff format.
1488 fdiagnostics-show-option
1489 Common Var(flag_diagnostics_show_option) Init(1)
1490 Amend appropriate diagnostic messages with the command line option that controls them.
1492 fdiagnostics-show-cwe
1493 Common Var(flag_diagnostics_show_cwe) Init(1)
1494 Print CWE identifiers for diagnostic messages, where available.
1496 fdiagnostics-show-rules
1497 Common Var(flag_diagnostics_show_rules) Init(1)
1498 Print any rules associated with diagnostic messages.
1500 fdiagnostics-path-format=
1501 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1502 Specify how to print any control-flow path associated with a diagnostic.
1504 fdiagnostics-plain-output
1505 Driver Common RejectNegative
1506 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1509 Common Joined RejectNegative UInteger
1510 -ftabstop=<number> Distance between tab stops for column reporting.
1513 Name(diagnostic_path_format) Type(int)
1516 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1519 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1522 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1524 fdiagnostics-show-path-depths
1525 Common Var(flag_diagnostics_show_path_depths) Init(0)
1526 Show stack depths of events in paths.
1528 fdiagnostics-text-art-charset=
1529 Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1530 -fdiagnostics-text-art-charset=[none|ascii|unicode|emoji] Determine which characters to use in text arg diagrams.
1533 Name(diagnostic_text_art_charset) Type(int)
1536 Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
1539 Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
1542 Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
1545 Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1547 fdiagnostics-minimum-margin-width=
1548 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1549 Set minimum width of left margin of source code when showing source.
1552 Common Joined RejectNegative Var(common_deferred_options) Defer
1553 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 Disable an optimization pass.
1556 Common Joined RejectNegative Var(common_deferred_options) Defer
1557 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 Enable an optimization pass.
1560 Common Joined RejectNegative Var(common_deferred_options) Defer
1561 -fdump-<type> Dump various compiler internals to a file.
1564 Driver RejectNegative
1567 Common RejectNegative Joined Var(flag_dump_final_insns)
1568 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1571 Common RejectNegative Joined Var(flag_dump_go_spec)
1572 -fdump-go-spec=filename Write all declarations to file as Go code.
1575 Common Var(flag_dump_noaddr)
1576 Suppress output of addresses in debugging dumps.
1579 Common Driver Var(flag_report_bug)
1580 Collect and dump debug information into temporary file if ICE in C/C++
1583 fdump-internal-locations
1584 Common Var(flag_dump_locations) Init(0)
1585 Dump detailed information on GCC's internal representation of source code locations.
1588 Common Var(flag_dump_passes) Init(0)
1589 Dump optimization passes.
1592 Common Var(flag_dump_unnumbered)
1593 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1595 fdump-unnumbered-links
1596 Common Var(flag_dump_unnumbered_links)
1597 Suppress output of previous and next insn numbers in debugging dumps.
1600 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1601 Enable CFI tables via GAS assembler directives.
1604 Common Var(flag_early_inlining) Init(1) Optimization
1605 Perform early inlining.
1607 feliminate-dwarf2-dups
1609 Does nothing. Preserved for backward compatibility.
1612 Common Var(flag_ipa_sra) Init(0) Optimization
1613 Perform interprocedural reduction of aggregates.
1615 feliminate-unused-debug-symbols
1616 Common Var(flag_debug_only_used_symbols) Init(1)
1617 Perform unused symbol elimination in debug info.
1619 feliminate-unused-debug-types
1620 Common Var(flag_eliminate_unused_debug_types) Init(1)
1621 Perform unused type elimination in debug info.
1623 femit-class-debug-always
1624 Common Var(flag_emit_class_debug_always) Init(0)
1625 Do not suppress C++ class debug information.
1628 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1629 Enable exception handling.
1631 fexpensive-optimizations
1632 Common Var(flag_expensive_optimizations) Optimization
1633 Perform a number of minor, expensive optimizations.
1636 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1637 -fexcess-precision=[fast|standard|16] Specify handling of excess floating-point precision.
1640 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1643 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1646 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1649 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1651 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1652 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1653 fpermitted-flt-eval-methods=
1654 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1655 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1658 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)
1661 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1664 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1670 Common Var(flag_fat_lto_objects)
1671 Output lto objects containing both the intermediate language and binary output.
1674 Common Var(flag_finite_math_only) Optimization SetByCombined
1675 Assume no NaNs or infinities are generated.
1678 Common Var(flag_finite_loops) Optimization Init(0)
1679 Assume that loops with an exit will terminate and not loop indefinitely.
1682 Common Joined RejectNegative Var(common_deferred_options) Defer
1683 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1686 Common Var(flag_float_store) Optimization
1687 Don't allocate floats and doubles in extended-precision registers.
1691 Does nothing. Preserved for backward compatibility.
1694 Common Var(flag_forward_propagate) Optimization
1695 Perform a forward propagation pass on RTL.
1698 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1699 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1702 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1705 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1708 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_ON)
1711 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1713 ffp-int-builtin-inexact
1714 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1715 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1717 ; Nonzero means don't put addresses of constant functions in registers.
1718 ; Used for compiling the Unix kernel, where strange substitutions are
1719 ; done on the assembly output.
1721 Common Var(flag_no_function_cse,0) Optimization
1722 Allow function addresses to be held in registers.
1725 Common Var(flag_function_sections)
1726 Place each function into its own section.
1729 Common Var(flag_gcse) Optimization
1730 Perform global common subexpression elimination.
1733 Common Var(flag_gcse_lm) Init(1) Optimization
1734 Perform enhanced load motion during global common subexpression elimination.
1737 Common Var(flag_gcse_sm) Init(0) Optimization
1738 Perform store motion after global common subexpression elimination.
1741 Common Var(flag_gcse_las) Init(0) Optimization
1742 Perform redundant load after store elimination in global common subexpression
1746 Common Var(flag_gcse_after_reload) Optimization
1747 Perform global common subexpression elimination after register allocation has
1751 Name(dwarf_gnat_encodings) Type(int)
1754 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1757 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1760 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1763 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1764 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1766 ; This option is not documented yet as its semantics will change.
1768 Common Var(flag_graphite) Optimization
1769 Enable in and out of Graphite representation.
1772 Common Var(flag_graphite_identity) Optimization
1773 Enable Graphite Identity transformation.
1775 fhoist-adjacent-loads
1776 Common Var(flag_hoist_adjacent_loads) Optimization
1777 Enable hoisting adjacent loads to encourage generating conditional move
1781 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1782 ; Always keep a pointer to a live memory block
1785 Common Var(flag_large_source_files) Init(0)
1786 Improve GCC's ability to track column numbers in large source files,
1787 at the expense of slower compilation.
1789 floop-parallelize-all
1790 Common Var(flag_loop_parallelize_all) Optimization
1791 Mark all loops as parallel.
1794 Common Alias(floop-nest-optimize)
1795 Enable loop nest transforms. Same as -floop-nest-optimize.
1798 Common Var(flag_loop_interchange) Optimization
1799 Enable loop interchange on trees.
1802 Common Alias(floop-nest-optimize)
1803 Enable loop nest transforms. Same as -floop-nest-optimize.
1805 floop-unroll-and-jam
1806 Common Var(flag_unroll_jam) Optimization
1807 Perform unroll-and-jam on loops.
1811 Enable support for GNU transactional memory.
1814 Common Var(flag_gnu_unique) Init(1)
1815 Use STB_GNU_UNIQUE if supported by the assembler.
1819 Does nothing. Preserved for backward compatibility.
1822 Common Var(flag_loop_nest_optimize) Optimization
1823 Enable the loop nest optimizer.
1825 fstrict-volatile-bitfields
1826 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1827 Force bitfield accesses to match their type width.
1830 Common Var(flag_store_merging) Optimization
1831 Merge adjacent stores.
1833 fguess-branch-probability
1834 Common Var(flag_guess_branch_prob) Optimization
1835 Enable guessing of branch probabilities.
1838 Common Driver Var(flag_hardened)
1839 Enable various security-relevant flags.
1842 Common Var(flag_harden_compares) Optimization
1843 Harden conditionals not used in branches, checking reversed conditions.
1845 fharden-conditional-branches
1846 Common Var(flag_harden_conditional_branches) Optimization
1847 Harden conditional branches by checking reversed conditions.
1849 fharden-control-flow-redundancy
1850 Common Var(flag_harden_control_flow_redundancy) Optimization
1851 Harden control flow by recording and checking execution paths.
1854 Common Var(flag_harden_control_flow_redundancy_skip_leaf) Optimization
1855 Disable CFR in leaf functions.
1857 fhardcfr-check-returning-calls
1858 Common Var(flag_harden_control_flow_redundancy_check_returning_calls) Init(-1) Optimization
1859 Check CFR execution paths also before calls followed by returns of their results.
1861 fhardcfr-check-exceptions
1862 Common Var(flag_harden_control_flow_redundancy_check_exceptions) Init(-1) Optimization
1863 Check CFR execution paths also when exiting a function through an exception.
1865 fhardcfr-check-noreturn-calls=
1866 Common Joined RejectNegative Enum(hardcfr_check_noreturn_calls) Var(flag_harden_control_flow_redundancy_check_noreturn) Init(HCFRNR_UNSPECIFIED) Optimization
1867 -fhardcfr-check-noreturn-calls=[always|no-xthrow|nothrow|never] Check CFR execution paths also before calling noreturn functions.
1870 Name(hardcfr_check_noreturn_calls) Type(enum hardcfr_noret) UnknownError(unknown hardcfr noreturn checking level %qs)
1873 Enum(hardcfr_check_noreturn_calls) String(never) Value(HCFRNR_NEVER)
1876 Enum(hardcfr_check_noreturn_calls) String(nothrow) Value(HCFRNR_NOTHROW)
1879 Enum(hardcfr_check_noreturn_calls) String(no-xthrow) Value(HCFRNR_NO_XTHROW)
1882 Enum(hardcfr_check_noreturn_calls) String(always) Value(HCFRNR_ALWAYS)
1884 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1885 ; Generate position-independent code for executables if possible
1886 ; On SVR4 targets, it also controls whether or not to emit a
1887 ; string identifying the compiler.
1889 Common Var(flag_no_ident,0)
1890 Process #ident directives.
1893 Common Var(flag_if_conversion) Optimization
1894 Perform conversion of conditional jumps to branchless equivalents.
1897 Common Var(flag_if_conversion2) Optimization
1898 Perform conversion of conditional jumps to conditional execution.
1901 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1902 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1905 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1908 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1911 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1914 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1916 ftree-loop-if-convert
1917 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1918 Convert conditional jumps in innermost loops to branchless equivalents.
1920 ftree-loop-if-convert-stores
1922 Does nothing. Preserved for backward compatibility.
1924 ; -finhibit-size-directive inhibits output of .size for ELF.
1925 ; This is used only for compiling crtstuff.c,
1926 ; and it may be extended to other effects
1927 ; needed for crtstuff.c on other systems.
1928 finhibit-size-directive
1929 Common Var(flag_inhibit_size_directive)
1930 Do not generate .size directives.
1933 Common Var(flag_indirect_inlining) Optimization
1934 Perform indirect inlining.
1936 ; General flag to enable inlining. Specifying -fno-inline will disable
1937 ; all inlining apart from always-inline functions.
1939 Common Var(flag_no_inline,0) Init(0) Optimization
1940 Enable inlining of function declared \"inline\", disabling disables all inlining.
1942 finline-small-functions
1943 Common Var(flag_inline_small_functions) Optimization
1944 Integrate functions into their callers when code size is known not to grow.
1947 Common Var(flag_inline_functions) Optimization
1948 Integrate functions not declared \"inline\" into their callers when profitable.
1950 finline-functions-called-once
1951 Common Var(flag_inline_functions_called_once) Optimization
1952 Integrate functions only required by their single caller.
1955 Common RejectNegative Joined Alias(finline-limit=)
1958 Common RejectNegative Joined UInteger
1959 -finline-limit=<number> Limit the size of inlined functions to <number>.
1962 Common Var(flag_inline_atomics) Init(1) Optimization
1963 Inline __atomic operations when a lock free instruction sequence is available.
1966 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_ALL) Enum(ilsop_fn) Init(ILSOP_NONE) Optimization Undocumented
1968 fno-inline-stringops
1969 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_NONE) Enum(ilsop_fn) Optimization Undocumented
1972 Common Joined Var(flag_inline_stringops) EnumSet Enum(ilsop_fn) Optimization
1973 -finline-stringops[=memcmp|memcpy|memmove|memset]
1974 Expand supported mem/str operations inline, even if against optimization.
1977 Name(ilsop_fn) Type(enum ilsop_fn) UnknownError(unavailable stringop for inlining %qs)
1979 ; This is not part of any set.
1981 ; Enum(ilsop_fn) String(none) Value(ILSOP_NONE)
1984 Enum(ilsop_fn) String(memcmp) Value(ILSOP_MEMCMP) Set(1)
1987 Enum(ilsop_fn) String(memcpy) Value(ILSOP_MEMCPY) Set(2)
1990 Enum(ilsop_fn) String(memmove) Value(ILSOP_MEMMOVE) Set(3)
1993 Enum(ilsop_fn) String(memset) Value(ILSOP_MEMSET) Set(4)
1995 ; This is not part of any set either.
1997 ; Enum(ilsop_fn) String(all) Value(ILSOP_ALL)
2000 Common RejectNegative Alias(fcf-protection=,full)
2003 Common Joined RejectNegative Enum(cf_protection_level) EnumSet Var(flag_cf_protection) Init(CF_NONE)
2004 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
2005 instructions have valid targets.
2008 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
2011 Enum(cf_protection_level) String(full) Value(CF_FULL) Set(1)
2014 Enum(cf_protection_level) String(branch) Value(CF_BRANCH) Set(2)
2017 Enum(cf_protection_level) String(return) Value(CF_RETURN) Set(3)
2020 Enum(cf_protection_level) String(check) Value(CF_CHECK) Set(4)
2023 Enum(cf_protection_level) String(none) Value(CF_NONE) Set(1)
2025 finstrument-functions
2026 Common Var(flag_instrument_function_entry_exit,1)
2027 Instrument function entry and exit with profiling calls.
2029 finstrument-functions-once
2030 Common Var(flag_instrument_function_entry_exit,2)
2031 Instrument function entry and exit with profiling calls invoked once.
2033 finstrument-functions-exclude-function-list=
2034 Common RejectNegative Joined
2035 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
2037 finstrument-functions-exclude-file-list=
2038 Common RejectNegative Joined
2039 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
2042 Common Var(flag_ipa_cp) Optimization
2043 Perform interprocedural constant propagation.
2046 Common Var(flag_ipa_cp_clone) Optimization
2047 Perform cloning to make Interprocedural constant propagation stronger.
2051 Does nothing. Preserved for backward compatibility.
2054 Common Var(flag_ipa_bit_cp) Optimization
2055 Perform interprocedural bitwise constant propagation.
2058 Common Var(flag_ipa_modref) Optimization
2059 Perform interprocedural modref analysis.
2062 Common Var(flag_ipa_profile) Init(0) Optimization
2063 Perform interprocedural profile propagation.
2066 Common Var(flag_ipa_pta) Init(0) Optimization
2067 Perform interprocedural points-to analysis.
2070 Common Var(flag_ipa_pure_const) Init(0) Optimization
2071 Discover pure and const functions.
2074 Common Var(flag_ipa_icf) Optimization
2075 Perform Identical Code Folding for functions and read-only variables.
2078 Common Var(flag_ipa_icf_functions) Optimization
2079 Perform Identical Code Folding for functions.
2082 Common Var(flag_ipa_icf_variables) Optimization
2083 Perform Identical Code Folding for variables.
2086 Common Var(flag_ipa_reference) Init(0) Optimization
2087 Discover read-only and non addressable static variables.
2089 fipa-reference-addressable
2090 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
2091 Discover read-only, write-only and non-addressable static variables.
2093 fipa-stack-alignment
2094 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
2095 Reduce stack alignment on call sites if possible.
2099 Does nothing. Preserved for backward compatibility.
2103 Does nothing. Preserved for backward compatibility.
2106 Common Var(flag_ipa_vrp) Optimization
2107 Perform IPA Value Range Propagation.
2110 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
2111 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
2113 fipa-strict-aliasing
2114 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
2115 Assume strict aliasing rules apply across (uninlined) function boundaries.
2118 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
2121 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2124 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2127 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2128 -fira-region=[one|all|mixed] Set regions for IRA.
2131 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2134 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2137 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2140 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2143 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2144 Use IRA based register pressure calculation
2145 in RTL hoist optimizations.
2148 Common Var(flag_ira_loop_pressure) Optimization
2149 Use IRA based register pressure calculation
2150 in RTL loop optimizations.
2152 fira-share-save-slots
2153 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2154 Share slots for saving different hard registers.
2156 fira-share-spill-slots
2157 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2158 Share stack slots for spilled pseudo-registers.
2161 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2162 -fira-verbose=<number> Control IRA's level of diagnostic messages.
2165 Common Var(flag_ivopts) Init(1) Optimization
2166 Optimize induction variables on trees.
2169 Common Var(flag_jump_tables) Init(1) Optimization
2170 Use jump tables for sufficiently large switch statements.
2173 Common Var(flag_bit_tests) Init(1) Optimization
2174 Use bit tests for sufficiently large switch statements.
2176 fkeep-inline-functions
2177 Common Var(flag_keep_inline_functions)
2178 Generate code for functions even if they are fully inlined.
2180 fkeep-static-functions
2181 Common Var(flag_keep_static_functions)
2182 Generate code for static functions even if they are never called.
2185 Common Var(flag_keep_static_consts) Init(1)
2186 Emit static const variables even if they are not used.
2189 Common Var(flag_leading_underscore) Init(-1)
2190 Give external symbols a leading underscore.
2194 Does nothing. Preserved for backward compatibility.
2197 Common Var(flag_lra_remat) Optimization
2198 Do CFG-sensitive rematerialization in LRA.
2202 Enable link-time optimization.
2205 Common RejectNegative Joined Var(flag_lto)
2206 Link-time optimization with number of parallel jobs or jobserver.
2209 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2212 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2215 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2218 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2221 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2224 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2227 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2228 Specify the algorithm to partition symbols and vars at linktime.
2230 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2231 flto-compression-level=
2232 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2233 Use zlib/zstd compression level <number> for IL.
2235 flto-odr-type-merging
2237 Does nothing. Preserved for backward compatibility.
2240 Common Var(flag_lto_report) Init(0)
2241 Report various link-time optimization statistics.
2244 Common Var(flag_lto_report_wpa) Init(0)
2245 Report various link-time optimization statistics for WPA only.
2248 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2249 Set errno after built-in math functions.
2252 Common Joined RejectNegative UInteger Var(flag_max_errors)
2253 -fmax-errors=<number> Maximum number of errors to report.
2256 Common Var(mem_report)
2257 Report on permanent memory allocation.
2260 Common Var(mem_report_wpa)
2261 Report on permanent memory allocation in WPA only.
2263 ; This will attempt to merge constant section constants, if 1 only
2264 ; string constants and constants from constant pool, if 2 also constant
2266 fmerge-all-constants
2267 Common Var(flag_merge_constants,2) Init(1)
2268 Attempt to merge identical constants and constant variables.
2271 Common Var(flag_merge_constants,1)
2272 Attempt to merge identical constants across compilation units.
2274 fmerge-debug-strings
2275 Common Var(flag_merge_debug_strings) Init(1)
2276 Attempt to merge identical debug strings across compilation units.
2279 Common RejectNegative Joined UInteger
2280 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
2282 fmin-function-alignment=
2283 Common Joined RejectNegative UInteger Var(flag_min_function_alignment) Optimization
2284 Align the start of every function.
2287 Common Var(flag_modulo_sched) Optimization
2288 Perform SMS based modulo scheduling before the first scheduling pass.
2290 fmodulo-sched-allow-regmoves
2291 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2292 Perform SMS based modulo scheduling with register moves allowed.
2294 fmove-loop-invariants
2295 Common Var(flag_move_loop_invariants) Optimization
2296 Move loop invariant computations out of loops.
2299 Common Var(flag_move_loop_stores) Optimization
2300 Move stores out of loops.
2303 Common Driver RejectNegative
2304 Building block for specs-based multilib-aware TFLAGS.
2307 Common Var(flag_dce) Init(1) Optimization
2308 Use the RTL dead code elimination pass.
2311 Common Var(flag_dse) Init(0) Optimization
2312 Use the RTL dead store elimination pass.
2314 freschedule-modulo-scheduled-loops
2315 Common Var(flag_resched_modulo_sched) Optimization
2316 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2318 fnon-call-exceptions
2319 Common Var(flag_non_call_exceptions) Optimization
2320 Support synchronous non-call exceptions.
2323 Driver Joined MissingArgError(targets missing after %qs)
2326 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2327 -foffload-options=<targets>=<options> Specify options for the offloading targets.
2330 Common Joined RejectNegative Enum(offload_abi)
2331 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2334 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2337 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2340 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2343 Common Var(flag_omit_frame_pointer) Optimization
2344 When possible do not generate stack frames.
2346 fopenmp-target-simd-clone
2347 Common Alias(fopenmp-target-simd-clone=,any,none)
2349 fopenmp-target-simd-clone=
2350 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2351 Generate SIMD clones for functions with the OpenMP declare target directive.
2354 Name(target_simd_clone_device) Type(int)
2357 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2360 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2363 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2366 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2369 Common Var(flag_opt_info) Optimization
2370 Enable all optimization info dumps on stderr.
2373 Common Joined RejectNegative Var(common_deferred_options) Defer
2374 -fopt-info[-<type>=filename] Dump compiler optimization details.
2376 fsave-optimization-record
2377 Common Var(flag_save_optimization_record) Optimization
2378 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2380 foptimize-register-move
2382 Does nothing. Preserved for backward compatibility.
2384 foptimize-sibling-calls
2385 Common Var(flag_optimize_sibling_calls) Optimization
2386 Optimize sibling and tail recursive calls.
2389 Common Var(flag_partial_inlining) Optimization
2390 Perform partial inlining.
2393 Common Var(pre_ipa_mem_report)
2394 Report on memory allocation before interprocedural optimization.
2396 fpost-ipa-mem-report
2397 Common Var(post_ipa_mem_report)
2398 Report on memory allocation before interprocedural optimization.
2401 Common Var(flag_pack_struct) Optimization
2402 Pack structure members together without holes.
2405 Common RejectNegative Joined UInteger Optimization
2406 -fpack-struct=<number> Set initial maximum structure member alignment.
2409 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2410 Return small aggregates in memory, not registers.
2413 Common Var(flag_peel_loops) Optimization
2414 Perform loop peeling.
2417 Common Var(flag_no_peephole,0) Optimization
2418 Enable machine specific peephole optimizations.
2421 Common Var(flag_peephole2) Optimization
2422 Enable an RTL peephole pass before sched2.
2425 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2426 Generate position-independent code if possible (large mode).
2429 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2430 Generate position-independent code for executables if possible (large mode).
2433 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2434 Generate position-independent code if possible (small mode).
2437 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2438 Generate position-independent code for executables if possible (small mode).
2441 Common Var(flag_plt) Init(1) Optimization
2442 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2445 Common Joined RejectNegative Var(common_deferred_options) Defer
2446 Specify a plugin to load.
2449 Common Joined RejectNegative Var(common_deferred_options) Defer
2450 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2452 fpredictive-commoning
2453 Common Var(flag_predictive_commoning) Optimization
2454 Run predictive commoning optimization.
2456 fprefetch-loop-arrays
2457 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2458 Generate prefetch instructions, if available, for arrays in loops.
2461 Common Var(profile_flag)
2462 Enable basic program profiling code.
2465 Common Var(profile_abs_path_flag)
2466 Generate absolute source path names for gcov.
2469 Common Var(profile_arc_flag)
2470 Insert arc-based program profiling code.
2473 Common Var(condition_coverage_flag)
2474 Insert condition coverage profiling code.
2477 Common Joined RejectNegative Var(profile_data_prefix)
2478 Set the top-level directory for storing the profile data.
2479 The default is 'pwd'.
2482 Common Joined RejectNegative Var(profile_note_location)
2483 Select the name for storing the profile note file.
2486 Common Var(flag_profile_correction)
2487 Enable correction of flow inconsistent profile data input.
2490 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2491 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2493 fprofile-filter-files=
2494 Common Joined RejectNegative Var(flag_profile_filter_files)
2495 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2497 fprofile-exclude-files=
2498 Common Joined RejectNegative Var(flag_profile_exclude_files)
2499 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2502 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2505 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2508 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2511 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2513 fprofile-reproducible=
2514 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2515 -fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate.
2518 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2521 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2524 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2527 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2529 fprofile-prefix-path=
2530 Common Joined RejectNegative Var(profile_prefix_path)
2531 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2533 fprofile-prefix-map=
2534 Common Joined RejectNegative Var(common_deferred_options) Defer
2535 -fprofile-prefix-map=<old>=<new> Map one directory name to another in GCOV coverage result.
2539 Enable common options for generating profile info for profile feedback directed optimizations.
2542 Common Joined RejectNegative
2543 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2545 fprofile-info-section
2546 Common RejectNegative
2547 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2549 fprofile-info-section=
2550 Common Joined RejectNegative Var(profile_info_section)
2551 Register the profile information in the specified section instead of using a constructor/destructor.
2553 fprofile-partial-training
2554 Common Var(flag_profile_partial_training) Optimization
2555 Do not assume that functions never executed during the train run are cold.
2558 Common Var(flag_profile_use)
2559 Enable common options for performing profile feedback directed optimizations.
2562 Common Joined RejectNegative
2563 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2566 Common Var(flag_profile_values)
2567 Insert code to profile values of expressions.
2570 Common Var(profile_report)
2571 Report on consistency of profile.
2573 fprofile-reorder-functions
2574 Common Var(flag_profile_reorder_functions) Optimization
2575 Enable function reordering that improves code placement.
2577 fpatchable-function-entry=
2578 Common Var(flag_patchable_function_entry) Joined Optimization
2579 Insert NOP instructions at each function entry.
2582 Common Var(common_deferred_options) Defer
2585 Common Joined RejectNegative Var(common_deferred_options) Defer
2586 -frandom-seed=<string> Make compile reproducible using <string>.
2588 ; This switch causes the command line that was used to create an
2589 ; object file to be recorded into the object file. The exact format
2590 ; of this recording is target and binary file format dependent.
2591 ; It is related to the -fverbose-asm switch, but that switch only
2592 ; records information in the assembler output file as comments, so
2593 ; they never reach the object file.
2594 frecord-gcc-switches
2595 Common Var(flag_record_gcc_switches)
2596 Record gcc command line switches in the object file.
2599 Common Var(flag_pcc_struct_return,0) Optimization
2600 Return small aggregates in registers.
2604 Does nothing. Preserved for backward compatibility.
2607 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2608 Tell DSE that the storage for a C++ object is dead when the constructor
2609 starts and when the destructor finishes.
2612 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2614 flimit-function-alignment
2615 Common Var(flag_limit_function_alignment) Optimization Init(0)
2618 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2621 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2622 -flive-patching=[inline-only-static|inline-clone] Control IPA
2623 optimizations to provide a safe compilation for live-patching. At the same
2624 time, provides multiple-level control on the enabled IPA optimizations.
2627 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2630 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2633 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2636 Common Var(flag_allocation_dce) Init(1) Optimization
2637 Tell DCE to remove unused C++ allocations.
2639 flive-range-shrinkage
2640 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2641 Relief of register pressure through live range shrinkage.
2644 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2645 Perform a register renaming optimization pass.
2648 Common Var(flag_schedule_fusion) Init(2) Optimization
2649 Perform a target dependent instruction fusion optimization pass.
2652 Common Var(flag_reorder_blocks) Optimization
2653 Reorder basic blocks to improve code placement.
2655 freorder-blocks-algorithm=
2656 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2657 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2660 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2663 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2666 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2668 freorder-blocks-and-partition
2669 Common Var(flag_reorder_blocks_and_partition) Optimization
2670 Reorder basic blocks and partition into hot and cold sections.
2673 Common Var(flag_reorder_functions) Optimization
2674 Reorder functions to improve code placement.
2676 frerun-cse-after-loop
2677 Common Var(flag_rerun_cse_after_loop) Optimization
2678 Add a common subexpression elimination pass after loop optimizations.
2682 Does nothing. Preserved for backward compatibility.
2685 Common Var(flag_rounding_math) Optimization SetByCombined
2686 Disable optimizations that assume default FP rounding behavior.
2689 Common Var(flag_schedule_interblock) Init(1) Optimization
2690 Enable scheduling across basic blocks.
2693 Common Var(flag_sched_pressure) Init(0) Optimization
2694 Enable register pressure sensitive insn scheduling.
2697 Common Var(flag_schedule_speculative) Init(1) Optimization
2698 Allow speculative motion of non-loads.
2701 Common Var(flag_schedule_speculative_load) Optimization
2702 Allow speculative motion of some loads.
2704 fsched-spec-load-dangerous
2705 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2706 Allow speculative motion of more loads.
2709 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2710 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2712 fsched2-use-superblocks
2713 Common Var(flag_sched2_use_superblocks) Optimization
2714 If scheduling post reload, do superblock scheduling.
2718 Does nothing. Preserved for backward compatibility.
2721 Common Var(flag_schedule_insns) Optimization
2722 Reschedule instructions before register allocation.
2725 Common Var(flag_schedule_insns_after_reload) Optimization
2726 Reschedule instructions after register allocation.
2728 ; This flag should be on when a target implements non-trivial
2729 ; scheduling hooks, maybe saving some information for its own sake.
2730 ; On IA64, for example, this is used for correct bundling.
2731 fselective-scheduling
2732 Common Var(flag_selective_scheduling) Optimization
2733 Schedule instructions using selective scheduling algorithm.
2735 fselective-scheduling2
2736 Common Var(flag_selective_scheduling2) Optimization
2737 Run selective scheduling after reload.
2740 Common Undocumented Joined Var(flag_self_test)
2741 Run self-tests, using the given path to locate test files.
2743 fsel-sched-pipelining
2744 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2745 Perform software pipelining of inner loops during selective scheduling.
2747 fsel-sched-pipelining-outer-loops
2748 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2749 Perform software pipelining of outer loops during selective scheduling.
2751 fsel-sched-reschedule-pipelined
2752 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2753 Reschedule pipelined regions without pipelining.
2755 fsemantic-interposition
2756 Common Var(flag_semantic_interposition) Init(1) Optimization
2757 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2759 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2760 ; of stalled insns into the ready list.
2761 fsched-stalled-insns
2762 Common Var(flag_sched_stalled_insns) Optimization UInteger
2763 Allow premature scheduling of queued insns.
2765 fsched-stalled-insns=
2766 Common RejectNegative Joined UInteger Optimization
2767 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2769 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2770 ; be examined for a dependency on a stalled insn that is candidate for
2771 ; premature removal from the queue of stalled insns into the ready list (has
2772 ; an effect only if the flag 'sched_stalled_insns' is set).
2773 fsched-stalled-insns-dep
2774 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2775 Set dependence distance checking in premature scheduling of queued insns.
2777 fsched-stalled-insns-dep=
2778 Common RejectNegative Joined UInteger Optimization
2779 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2781 fsched-group-heuristic
2782 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2783 Enable the group heuristic in the scheduler.
2785 fsched-critical-path-heuristic
2786 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2787 Enable the critical path heuristic in the scheduler.
2789 fsched-spec-insn-heuristic
2790 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2791 Enable the speculative instruction heuristic in the scheduler.
2793 fsched-rank-heuristic
2794 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2795 Enable the rank heuristic in the scheduler.
2797 fsched-last-insn-heuristic
2798 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2799 Enable the last instruction heuristic in the scheduler.
2801 fsched-dep-count-heuristic
2802 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2803 Enable the dependent count heuristic in the scheduler.
2806 Common Var(flag_section_anchors) Optimization
2807 Access data in the same section from shared anchor points.
2811 Does nothing. Preserved for backward compatibility.
2815 Does nothing. Preserved for backward compatibility.
2818 Common Var(flag_ree) Init(0) Optimization
2819 Turn on Redundant Extensions Elimination pass.
2822 Common Var(flag_show_column) Init(1)
2823 Show column numbers in diagnostics, when available. Default on.
2826 Common Var(flag_shrink_wrap) Optimization
2827 Emit function prologues only before parts of the function that need it,
2828 rather than at the top of the function.
2830 fshrink-wrap-separate
2831 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2832 Shrink-wrap parts of the prologue and epilogue separately.
2835 Common Var(flag_signaling_nans) Optimization SetByCombined
2836 Disable optimizations observable by IEEE signaling NaNs.
2839 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2840 Disable floating point optimizations that ignore the IEEE signedness of zero.
2842 fsingle-precision-constant
2843 Common Var(flag_single_precision_constant) Optimization
2844 Convert floating point constants to single precision constants.
2846 fsplit-ivs-in-unroller
2847 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2848 Split lifetimes of induction variables when loops are unrolled.
2851 Common Var(flag_split_stack) Init(-1)
2852 Generate discontiguous stack frames.
2855 Common Var(flag_split_wide_types) Optimization
2856 Split wide types into independent registers.
2858 fsplit-wide-types-early
2859 Common Var(flag_split_wide_types_early) Optimization
2860 Split wide types into independent registers earlier.
2863 Common Var(flag_ssa_backprop) Init(1) Optimization
2864 Enable backward propagation of use properties at the SSA level.
2867 Common Var(flag_ssa_phiopt) Optimization
2868 Optimize conditional patterns using SSA PHI nodes.
2871 Common Var(flag_stdarg_opt) Init(1) Optimization
2872 Optimize amount of stdarg registers saved to stack at start of function.
2874 fvariable-expansion-in-unroller
2875 Common Var(flag_variable_expansion_in_unroller) Optimization
2876 Apply variable expansion when loops are unrolled.
2879 Common RejectNegative Joined Optimization
2880 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2883 Common Alias(fstack-check=, specific, no)
2884 Insert stack checking code into the program. Same as -fstack-check=specific.
2886 fstack-clash-protection
2887 Common Var(flag_stack_clash_protection) Optimization
2888 Insert code to probe each page of stack space as it is allocated to protect
2889 from stack-clash style attacks.
2892 Common Var(common_deferred_options) Defer
2894 fstack-limit-register=
2895 Common RejectNegative Joined Var(common_deferred_options) Defer
2896 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2898 fstack-limit-symbol=
2899 Common RejectNegative Joined Var(common_deferred_options) Defer
2900 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2903 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2904 Use propolice as a stack protection method.
2906 fstack-protector-all
2907 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2908 Use a stack protection method for every function.
2910 fstack-protector-strong
2911 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2912 Use a smart stack protection method for certain functions.
2914 fstack-protector-explicit
2915 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2916 Use stack protection method only for functions with the stack_protect attribute.
2919 Common RejectNegative Var(flag_stack_usage)
2920 Output stack usage information on a per-function basis.
2924 Does nothing. Preserved for backward compatibility.
2926 ; Nonzero if we should do (language-dependent) alias analysis.
2927 ; Typically, this analysis will assume that expressions of certain
2928 ; types do not alias expressions of certain other types. Only used
2929 ; if alias analysis (in general) is enabled.
2931 Common Var(flag_strict_aliasing) Optimization
2932 Assume strict aliasing rules apply.
2936 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2939 Common RejectNegative Var(flag_strub, 0)
2940 Disable stack scrub entirely, disregarding strub attributes.
2943 Common RejectNegative Var(flag_strub, -4)
2944 Enable stack scrub as per attributes, with strict call checking.
2946 ; If any strub-enabling attribute is seen when the default or strict
2947 ; initializer values are in effect, flag_strub is bumped up by 2. The
2948 ; scrub mode gate function will then bump these initializer values to
2949 ; 0 if no strub-enabling attribute is seen. This minimizes the strub
2952 Common RejectNegative Var(flag_strub, -3) Init(-3)
2953 Restore default strub mode: as per attributes, with relaxed checking.
2956 Common RejectNegative Var(flag_strub, 3)
2957 Enable stack scrubbing for all viable functions.
2960 Common RejectNegative Var(flag_strub, 1)
2961 Enable at-calls stack scrubbing for all viable functions.
2964 Common RejectNegative Var(flag_strub, 2)
2965 Enable internal stack scrubbing for all viable functions.
2968 Common Var(flag_sync_libcalls) Init(1)
2969 Implement __atomic operations via libcalls to legacy __sync functions.
2972 Common Var(flag_syntax_only)
2973 Check for syntax errors, then stop.
2976 Common Var(flag_test_coverage)
2977 Create data files needed by \"gcov\".
2980 Common Var(flag_thread_jumps) Optimization
2981 Perform jump threading optimizations.
2984 Common Var(time_report)
2985 Report the time taken by each compiler pass.
2987 ftime-report-details
2988 Common Var(time_report_details)
2989 Record times taken by sub-phases separately.
2992 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2993 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2996 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2999 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
3002 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
3005 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
3008 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
3011 Common Var(flag_toplevel_reorder) Init(2) Optimization
3012 Reorder top level functions, variables, and asms.
3015 Common Var(flag_tracer) Optimization
3016 Perform superblock formation via tail duplication.
3019 Common Var(flag_trampolines) Init(HEAP_TRAMPOLINES_INIT)
3020 For targets that normally need trampolines for nested functions, always
3021 generate them instead of using descriptors.
3024 Common Joined RejectNegative Enum(trampoline_impl) Var(flag_trampoline_impl) Init(HEAP_TRAMPOLINES_INIT ? TRAMPOLINE_IMPL_HEAP : TRAMPOLINE_IMPL_STACK)
3025 Whether trampolines are generated in executable memory rather than
3029 Name(trampoline_impl) Type(enum trampoline_impl) UnknownError(unknown trampoline implementation %qs)
3032 Enum(trampoline_impl) String(stack) Value(TRAMPOLINE_IMPL_STACK)
3035 Enum(trampoline_impl) String(heap) Value(TRAMPOLINE_IMPL_HEAP)
3038 ; Zero means that floating-point math operations cannot generate a
3039 ; (user-visible) trap. This is the case, for example, in nonstop
3040 ; IEEE 754 arithmetic.
3042 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
3043 Assume floating-point operations can trap.
3046 Common Var(flag_trapv) Optimization
3047 Trap for signed overflow in addition, subtraction and multiplication.
3050 Common Var(flag_tree_ccp) Optimization
3051 Enable SSA-CCP optimization on trees.
3054 Common Var(flag_tree_bit_ccp) Optimization
3055 Enable SSA-BIT-CCP optimization on trees.
3059 Does nothing. Preserved for backward compatibility.
3062 Common Var(flag_tree_ch) Optimization
3063 Enable loop header copying on trees.
3065 ftree-coalesce-inlined-vars
3066 Common Ignore RejectNegative
3067 Does nothing. Preserved for backward compatibility.
3070 Common Var(flag_tree_coalesce_vars) Optimization
3071 Enable SSA coalescing of user variables.
3075 Does nothing. Preserved for backward compatibility.
3078 Common Var(flag_tree_copy_prop) Optimization
3079 Enable copy propagation on trees.
3081 ftree-store-copy-prop
3083 Does nothing. Preserved for backward compatibility.
3086 Common Var(flag_tree_cselim) Optimization
3087 Transform condition stores into unconditional ones.
3089 ftree-switch-conversion
3090 Common Var(flag_tree_switch_conversion) Optimization
3091 Perform conversions of switch initializations.
3094 Common Var(flag_tree_dce) Optimization
3095 Enable SSA dead code elimination optimization on trees.
3097 ftree-dominator-opts
3098 Common Var(flag_tree_dom) Optimization
3099 Enable dominator optimizations.
3102 Common Var(flag_tree_tail_merge) Optimization
3103 Enable tail merging on trees.
3106 Common Var(flag_tree_dse) Optimization
3107 Enable dead store elimination.
3110 Common Var(flag_tree_forwprop) Init(1) Optimization
3111 Enable forward propagation on trees.
3114 Common Var(flag_tree_fre) Optimization
3115 Enable Full Redundancy Elimination (FRE) on trees.
3118 Common Var(flag_optimize_strlen) Optimization
3119 Enable string length optimizations on trees.
3121 fisolate-erroneous-paths-dereference
3122 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
3123 Detect paths that trigger erroneous or undefined behavior due to
3124 dereferencing a null pointer. Isolate those paths from the main control
3125 flow and turn the statement with erroneous or undefined behavior into a trap.
3127 fisolate-erroneous-paths-attribute
3128 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
3129 Detect paths that trigger erroneous or undefined behavior due to a null value
3130 being used in a way forbidden by a returns_nonnull or nonnull
3131 attribute. Isolate those paths from the main control flow and turn the
3132 statement with erroneous or undefined behavior into a trap.
3134 ftree-loop-distribution
3135 Common Var(flag_tree_loop_distribution) Optimization
3136 Enable loop distribution on trees.
3138 ftree-loop-distribute-patterns
3139 Common Var(flag_tree_loop_distribute_patterns) Optimization
3140 Enable loop distribution for patterns transformed into a library call.
3143 Common Var(flag_tree_loop_im) Init(1) Optimization
3144 Enable loop invariant motion on trees.
3147 Common Alias(floop-nest-optimize)
3148 Enable loop nest transforms. Same as -floop-nest-optimize.
3151 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
3152 Create canonical induction variables in loops.
3155 Common Var(flag_tree_loop_optimize) Init(1) Optimization
3156 Enable loop optimizations on tree level.
3158 ftree-parallelize-loops=
3159 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
3160 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
3163 Common Var(flag_tree_phiprop) Init(1) Optimization
3164 Enable hoisting loads from conditional pointers.
3167 Common Var(flag_tree_pre) Optimization
3168 Enable SSA-PRE optimization on trees.
3171 Common Var(flag_tree_partial_pre) Optimization
3172 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
3175 Common Var(flag_tree_pta) Optimization
3176 Perform function-local points-to analysis on trees.
3179 Common Var(flag_tree_reassoc) Init(1) Optimization
3180 Enable reassociation on tree level.
3184 Does nothing. Preserved for backward compatibility.
3187 Common Var(flag_tree_sink) Optimization
3188 Enable SSA code sinking on trees.
3191 Common Var(flag_tree_slsr) Optimization
3192 Perform straight-line strength reduction.
3195 Common Var(flag_tree_sra) Optimization
3196 Perform scalar replacement of aggregates.
3199 Common Var(flag_tree_ter) Optimization
3200 Replace temporary expressions in the SSA->normal pass.
3203 Common Var(flag_tree_live_range_split) Optimization
3204 Perform live range splitting during the SSA->normal pass.
3207 Common Var(flag_tree_vrp) Init(0) Optimization
3208 Perform Value Range Propagation on trees.
3211 Common Var(flag_split_paths) Init(0) Optimization
3212 Split paths leading to loop backedges.
3214 funconstrained-commons
3215 Common Var(flag_unconstrained_commons) Optimization
3216 Assume common declarations may be overridden with ones with a larger
3220 Common Var(flag_unit_at_a_time) Init(1)
3221 Compile whole compilation unit at a time.
3224 Common Var(flag_unreachable_traps) Optimization
3225 Trap on __builtin_unreachable instead of using it for optimization.
3228 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3229 Perform loop unrolling when iteration count is known.
3232 Common Var(flag_unroll_all_loops) Optimization
3233 Perform loop unrolling for all loops.
3235 funroll-completely-grow-size
3236 Undocumented Var(flag_cunroll_grow_size) Optimization
3237 ; Internal undocumented flag, allow size growth during complete unrolling
3239 ; Nonzero means that loop optimizer may assume that the induction variables
3240 ; that control loops do not overflow and that the loops with nontrivial
3241 ; exit condition are not infinite
3242 funsafe-loop-optimizations
3244 Does nothing. Preserved for backward compatibility.
3247 Common Var(flag_associative_math) SetByCombined Optimization
3248 Allow optimization for floating-point arithmetic which may change the
3249 result of the operation due to rounding.
3252 Common Var(flag_reciprocal_math) SetByCombined Optimization
3253 Same as -fassociative-math for expressions which include division.
3255 ; Nonzero means that unsafe floating-point math optimizations are allowed
3256 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
3257 ; are allowed to assume that their arguments and results are "normal"
3258 ; (e.g., nonnegative for SQRT).
3259 funsafe-math-optimizations
3260 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3261 Allow math optimizations that may violate IEEE or ISO standards.
3264 Common Var(flag_unswitch_loops) Optimization
3265 Perform loop unswitching.
3268 Common Var(flag_split_loops) Optimization
3269 Perform loop splitting.
3271 fversion-loops-for-strides
3272 Common Var(flag_version_loops_for_strides) Optimization
3273 Version loops based on whether indices have a stride of one.
3276 Common Var(flag_unwind_tables) Optimization
3277 Just generate unwind tables for exception handling.
3280 Common Driver Negative(fuse-ld=gold)
3281 Use the bfd linker instead of the default linker.
3284 Common Driver Negative(fuse-ld=bfd)
3285 Use the gold linker instead of the default linker.
3288 Common Driver Negative(fuse-ld=lld)
3289 Use the lld LLVM linker instead of the default linker.
3292 Common Driver Negative(fuse-ld=mold)
3293 Use the Modern linker (MOLD) linker instead of the default linker.
3296 Common Undocumented Var(flag_use_linker_plugin)
3298 ; Positive if we should track variables, negative if we should run
3299 ; the var-tracking pass only to discard debug annotations, zero if
3300 ; we're not to run it.
3302 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3303 Perform variable tracking.
3305 ; Positive if we should track variables at assignments, negative if
3306 ; we should run the var-tracking pass only to discard debug
3308 fvar-tracking-assignments
3309 Common Var(flag_var_tracking_assignments) PerFunction
3310 Perform variable tracking by annotating assignments.
3312 ; Nonzero if we should toggle flag_var_tracking_assignments after
3313 ; processing options and computing its default. */
3314 fvar-tracking-assignments-toggle
3315 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3316 Toggle -fvar-tracking-assignments.
3318 ; Positive if we should track uninitialized variables, negative if
3319 ; we should run the var-tracking pass only to discard debug
3321 fvar-tracking-uninit
3322 Common Var(flag_var_tracking_uninit) PerFunction
3323 Perform variable tracking and also tag variables that are uninitialized.
3325 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3327 Common Var(flag_tree_vectorize) Optimization
3328 Enable vectorization on trees.
3330 ftree-vectorizer-verbose=
3331 Common Joined RejectNegative Ignore
3332 Does nothing. Preserved for backward compatibility.
3334 ftree-loop-vectorize
3335 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3336 Enable loop vectorization on trees.
3339 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3340 Enable basic block vectorization (SLP) on trees.
3343 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3344 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the cost model for vectorization.
3347 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3348 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the vectorization cost model for code marked with a simd directive.
3351 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3354 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3357 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3360 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3363 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3366 Common Alias(fvect-cost-model=,dynamic,unlimited)
3367 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
3369 ftree-vect-loop-version
3371 Does nothing. Preserved for backward compatibility.
3374 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3375 Enable copy propagation of scalar-evolution information.
3377 ftrivial-auto-var-init=
3378 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3379 -ftrivial-auto-var-init=[uninitialized|pattern|zero] Add initializations to automatic variables.
3382 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3385 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3388 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3391 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3393 ; -fverbose-asm causes extra commentary information to be produced in
3394 ; the generated assembly code (to make it more readable). This option
3395 ; is generally only of use to those who actually need to read the
3396 ; generated assembly code (perhaps while debugging the compiler itself).
3397 ; -fno-verbose-asm, the default, causes the extra information
3398 ; to not be added and is useful when comparing two assembler files.
3400 Common Var(flag_verbose_asm)
3401 Add extra commentary to assembler output.
3404 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3405 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
3408 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3411 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3414 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3417 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3420 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3423 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3424 Validate vtable pointers before using them.
3427 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3430 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3433 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3436 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3439 Common Var(flag_vtv_counts)
3440 Output vtable verification counters.
3443 Common Var(flag_vtv_debug)
3444 Output vtable verification pointer sets information.
3447 Common Var(flag_value_profile_transformations) Optimization
3448 Use expression value profiles in optimizations.
3451 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3452 Construct webs and split unrelated uses of single variable.
3454 ftree-builtin-call-dce
3455 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3456 Enable conditional dead code elimination for builtin calls.
3459 Common Var(flag_whole_program) Init(0)
3460 Perform whole program optimizations.
3463 Common Var(flag_wrapv_pointer) Optimization
3464 Assume pointer overflow wraps around.
3467 Common Var(flag_wrapv) Optimization
3468 Assume signed arithmetic overflow wraps around.
3470 fzero-initialized-in-bss
3471 Common Var(flag_zero_initialized_in_bss) Init(1)
3472 Put zero initialized data in the bss section.
3474 fzero-call-used-regs=
3475 Common RejectNegative Joined
3476 Clear call-used registers upon function return.
3479 Common Driver RejectNegative JoinedOrMissing
3480 Generate debug information in default format.
3483 Common Driver Var(dwarf2out_as_loc_support)
3484 Assume assembler support for (DWARF2+) .loc directives.
3487 Common Driver Var(dwarf2out_as_locview_support)
3488 Assume assembler support for view in (DWARF2+) .loc directives.
3491 Common Driver JoinedOrMissing
3492 Generate debug information in CodeView format.
3495 Common Driver WarnRemoved
3496 Does nothing. Preserved for backward compatibility.
3499 Common Driver WarnRemoved
3500 Does nothing. Preserved for backward compatibility.
3503 Common Driver WarnRemoved
3504 Does nothing. Preserved for backward compatibility.
3507 Common Driver WarnRemoved
3508 Does nothing. Preserved for backward compatibility.
3511 Common Driver Var(debug_column_info,1) Init(1)
3512 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3514 ; The CTF generation process feeds off DWARF dies. This option implicitly
3515 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3517 Common Driver RejectNegative JoinedOrMissing
3518 Generate CTF debug information at default level.
3521 Common Driver RejectNegative JoinedOrMissing
3522 Generate BTF debug information at default level.
3525 Common Driver JoinedOrMissing RejectNegative
3526 Generate debug information in default version of DWARF format.
3529 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT) RejectNegative
3530 Generate debug information in DWARF v2 (or later) format.
3533 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3534 Use 32-bit DWARF format when emitting DWARF debug information.
3537 Common Driver Var(dwarf_offset_size,8) RejectNegative
3538 Use 64-bit DWARF format when emitting DWARF debug information.
3541 Common Driver JoinedOrMissing RejectNegative
3542 Generate debug information in default extended format.
3545 Common Driver Var(debug_inline_points)
3546 Generate extended entry point information for inlined functions.
3548 ginternal-reset-location-views
3549 Common Driver Var(debug_internal_reset_location_views) Init(2)
3550 Compute locview reset points based on insn length estimates.
3553 RejectNegative Joined Undocumented
3554 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3557 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3558 Don't generate DWARF pubnames and pubtypes sections.
3561 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3562 Generate DWARF pubnames and pubtypes sections.
3565 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3566 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3568 grecord-gcc-switches
3569 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3570 Record gcc command line switches in DWARF DW_AT_producer.
3573 Common Driver Var(dwarf_split_debug_info) Init(0)
3574 Generate debug information in separate .dwo files.
3577 Common Driver WarnRemoved
3578 Does nothing. Preserved for backward compatibility.
3581 Common Driver WarnRemoved
3582 Does nothing. Preserved for backward compatibility.
3584 gstatement-frontiers
3585 Common Driver Var(debug_nonbind_markers_p) PerFunction
3586 Emit progressive recommended breakpoint locations.
3589 Common Driver Var(dwarf_strict) Init(0)
3590 Don't emit DWARF additions beyond selected version.
3593 Common Driver Var(flag_describe_dies) Init(0)
3594 Add description attributes to some DWARF DIEs that have no name attribute.
3597 Common Driver Var(flag_gtoggle)
3598 Toggle debug information generation.
3600 gvariable-location-views
3601 Common Driver Var(debug_variable_location_views, 1)
3602 Augment variable location lists with progressive views.
3604 gvariable-location-views=incompat5
3605 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3608 Common Driver JoinedOrMissing RejectNegative
3609 Generate debug information in VMS format.
3612 Common Driver WarnRemoved
3613 Does nothing. Preserved for backward compatibility.
3616 Common Driver JoinedOrMissing WarnRemoved
3617 Does nothing. Preserved for backward compatibility.
3620 Name(compressed_debug_sections) Type(int)
3622 ; Since -gz= is completely handled in specs, the values aren't used and we
3623 ; assign arbitrary constants.
3625 Enum(compressed_debug_sections) String(none) Value(0)
3628 Enum(compressed_debug_sections) String(zlib) Value(1)
3631 Enum(compressed_debug_sections) String(zstd) Value(2)
3634 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3638 Generate compressed debug sections.
3641 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3642 -gz=<format> Generate compressed debug sections in format <format>.
3645 Driver Joined Separate
3648 Common Joined Var(plugindir_string) Init(0)
3649 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3652 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3653 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3656 Driver Joined Separate
3661 no-canonical-prefixes
3680 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3681 -o <file> Place output into <file>.
3684 Common Var(profile_flag)
3685 Enable function profiling.
3688 Driver Var(pass_exit_codes)
3691 Common Alias(Wpedantic)
3694 Common Var(flag_pedantic_errors)
3695 Like -pedantic but issue them as errors.
3701 Driver Var(use_pipes)
3704 Driver JoinedOrMissing Var(print_file_name)
3706 print-libgcc-file-name
3709 print-multi-directory
3710 Driver Var(print_multi_directory)
3713 Driver Var(print_multi_lib)
3715 print-multi-os-directory
3716 Driver Var(print_multi_os_directory)
3719 Driver Var(print_multiarch)
3722 Driver JoinedOrMissing Var(print_prog_name)
3725 Driver Var(print_search_dirs)
3728 Driver Var(print_sysroot)
3730 print-sysroot-headers-suffix
3731 Driver Var(print_sysroot_headers_suffix)
3734 Common Var(quiet_flag) RejectDriver
3735 Do not display functions compiled or elapsed time.
3753 Driver Var(report_times)
3756 Driver JoinedOrMissing
3759 Driver Joined Separate
3763 ; C option, but driver must not handle as "-u ndef".
3766 Common Driver Var(verbose_flag)
3767 Enable verbose output.
3770 Common Var(version_flag) RejectDriver
3771 Display the compiler's version.
3774 Common Var(inhibit_warnings)
3778 Driver Separate Var(wrapper_string)
3781 Driver Joined Separate
3784 Driver RejectNegative Negative(static-pie)
3785 Create a shared library.
3791 Driver Separate Alias(specs=)
3804 ; Documented for Fortran, but always accepted by driver.
3808 ; Documented for Modula-2, but always accepted by driver.
3812 ; Documented for D, but always accepted by driver.
3816 ; Documented for Fortran, but always accepted by driver.
3823 ; Documented for Go, but always accepted by driver.
3844 Driver RejectNegative Negative(shared)
3845 Don't create a dynamically linked position independent executable.
3848 Driver RejectNegative Negative(no-pie)
3849 Create a dynamically linked position independent executable.
3852 Driver RejectNegative Negative(pie)
3853 Create a static position independent executable.
3856 Driver Joined Separate
3859 Common Var(flag_ipa_ra) Optimization
3860 Use caller save register across calls if possible.
3862 ; This comment is to ensure we retain the blank line above.