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.
874 Common Var(warn_missing_profile) Init(1) Warning
875 Warn in case profiles in -fprofile-use do not exist.
877 Wvector-operation-performance
878 Common Var(warn_vector_operation_performance) Warning
879 Warn when a vector operation is compiled outside the SIMD.
882 Common Var(warn_tsan) Init(1) Warning
883 Warn about unsupported features in ThreadSanitizer.
898 Common Separate Var(aux_info_file_name)
899 -aux-info <file> Emit declaration information into <file>.
902 Common Joined Alias(aux-info)
912 -d<letters> Enable dumps from specific passes of the compiler.
915 Driver Common Separate Var(dump_base_name)
916 -dumpbase <file> Set the file basename to be used for dumps.
919 Driver Common Separate Var(dump_base_ext)
920 -dumpbase-ext .<ext> Drop a trailing .<ext> from the dump basename to name auxiliary output files.
923 Driver Common Separate Var(dump_dir_name)
924 -dumpdir <dir> Set the directory name to be used for dumps.
939 Driver Joined Separate
941 ; This option has historically been passed down to the linker by an
942 ; accident of a %{e*} spec, so ensure it continues to be passed down
943 ; as a single option. The supported option for this purpose is
944 ; -rdynamic. See PR 47390.
948 ; The version of the C++ ABI in use. The following values are allowed:
950 ; 0: The version of the ABI believed most conformant with the C++ ABI
951 ; specification. This ABI may change as bugs are discovered and fixed.
952 ; Therefore, 0 will not necessarily indicate the same ABI in different
955 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
957 ; 2: The version of the ABI first used in G++ 3.4, and the default
960 ; 3: The version of the ABI that fixes the missing underscore
961 ; in template non-type arguments of pointer type.
963 ; 4: The version of the ABI that introduces unambiguous mangling of
964 ; vector types. First selectable in G++ 4.5.
966 ; 5: The version of the ABI that ignores attribute const/noreturn
967 ; in function pointer mangling, and corrects mangling of decltype and
968 ; function parameters used in other parameters and the return type.
969 ; First selectable in G++ 4.6.
971 ; 6: The version of the ABI that doesn't promote scoped enums to int and
972 ; changes the mangling of template argument packs, const/static_cast,
973 ; prefix ++ and --, and a class scope function used as a template
975 ; First selectable in G++ 4.7.
977 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
978 ; corrects the mangling of lambdas in default argument scope.
979 ; First selectable in G++ 4.8.
981 ; 8: The version of the ABI that corrects the substitution behavior of
982 ; function types with function-cv-qualifiers.
983 ; First selectable in G++ 4.9 and default in G++ 5.
985 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
986 ; First selectable and default in G++ 5.2.
988 ; 10: The version of the ABI that mangles attributes that affect type
989 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
990 ; Default in G++ 6 (set in c_common_post_options).
992 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
993 ; and introduces new inheriting constructor handling.
996 ; 12: Corrects the calling convention for classes with only deleted copy/move
997 ; constructors and changes passing/returning of empty records.
998 ; Default in G++ 8.1.
1000 ; 13: Fixes the accidental change in 12 to the calling convention for classes
1001 ; with deleted copy constructor and trivial move constructor.
1002 ; Default in G++ 8.2.
1004 ; 14: Corrects the mangling of nullptr expression.
1005 ; Default in G++ 10.
1007 ; 15: Corrects G++ 10 ABI tag regression [PR98481].
1008 ; Available, but not default, in G++ 10.3.
1010 ; 16: Changes the mangling of __alignof__ to be distinct from that of alignof.
1011 ; Adds missing 'on' in mangling of operator names in some cases.
1012 ; Default in G++ 11.
1014 ; 17: Fixes layout of classes that inherit from aggregate classes with default
1015 ; member initializers in C++14 and up.
1016 ; Default in G++ 12.
1018 ; 18: Corrects errors in mangling of lambdas with additional context.
1019 ; Default in G++ 13.
1021 ; 19: Emits ABI tags if needed in structured binding mangled names.
1022 ; Ignores cv-quals on [[no_unique_object]] members.
1023 ; Mangles constraints on function templates.
1024 ; Default in G++ 14.
1026 ; Additional positive integers will be assigned as new versions of
1027 ; the ABI become the default version of the ABI.
1029 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1030 The version of the C++ ABI in use.
1032 faggressive-loop-optimizations
1033 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1034 Aggressively optimize loops using language constraints.
1037 Common Var(flag_align_functions) Optimization
1038 Align the start of functions.
1041 Common RejectNegative Joined Var(str_align_functions) Optimization
1044 Common Var(flag_align_jumps) Optimization
1045 Align labels which are only reached by jumping.
1048 Common RejectNegative Joined Var(str_align_jumps) Optimization
1051 Common Var(flag_align_labels) Optimization
1055 Common RejectNegative Joined Var(str_align_labels) Optimization
1058 Common Var(flag_align_loops) Optimization
1059 Align the start of loops.
1062 Common RejectNegative Joined Var(str_align_loops) Optimization
1064 fallow-store-data-races
1065 Common Var(flag_store_data_races) Optimization
1066 Allow the compiler to introduce new data races on stores.
1069 Common Var(flag_analyzer)
1070 Enable static analysis pass.
1074 Does nothing. Preserved for backward compatibility.
1078 Does nothing. Preserved for backward compatibility.
1080 fargument-noalias-global
1082 Does nothing. Preserved for backward compatibility.
1084 fargument-noalias-anything
1086 Does nothing. Preserved for backward compatibility.
1089 Common Driver Joined
1090 Select what to sanitize.
1093 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1094 Select type of coverage sanitization.
1097 Name(sanitize_coverage) Type(int)
1100 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1103 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1105 fasan-shadow-offset=
1106 Common Joined RejectNegative Var(common_deferred_options) Defer
1107 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1110 Common Joined RejectNegative Var(common_deferred_options) Defer
1111 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1112 in user-defined sections.
1116 After diagnosing undefined behavior attempt to continue execution.
1120 This switch is deprecated; use -fsanitize-recover= instead.
1123 Common Driver Joined
1124 Use traps instead of diagnostics of undefined behavior sanitizers.
1129 fsanitize-address-use-after-scope
1130 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1132 fsanitize-undefined-trap-on-error
1133 Common Driver Alias(fsanitize-trap)
1134 This switch is deprecated; use -fsanitize-trap= instead.
1136 fasynchronous-unwind-tables
1137 Common Var(flag_asynchronous_unwind_tables) Optimization
1138 Generate unwind tables that are exact at each instruction boundary.
1141 Common Var(flag_auto_inc_dec) Init(1) Optimization
1142 Generate auto-inc/dec instructions.
1145 Common Var(flag_auto_profile)
1146 Use sample profile information for call graph node weights. The default
1147 profile file is fbdata.afdo in 'pwd'.
1150 Common Joined RejectNegative Var(auto_profile_file)
1151 Use sample profile information for call graph node weights. The profile
1152 file is specified in the argument.
1154 ; -fcheck-bounds causes gcc to generate array bounds checks.
1155 ; For C, C++ and ObjC: defaults off.
1156 ; For Java: defaults to on.
1157 ; For Fortran: defaults to off.
1159 Common Var(flag_bounds_check)
1160 Generate code to check bounds before indexing arrays.
1163 Common Var(flag_branch_on_count_reg) Optimization
1164 Replace add, compare, branch with branch on count register.
1166 fbranch-probabilities
1167 Common Var(flag_branch_probabilities) Optimization
1168 Use profiling information for branch probabilities.
1170 fbranch-target-load-optimize
1172 Does nothing. Preserved for backward compatibility.
1174 fbranch-target-load-optimize2
1176 Does nothing. Preserved for backward compatibility.
1180 Does nothing. Preserved for backward compatibility.
1183 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1184 Output callgraph information on a per-file basis.
1187 Common RejectNegative Joined
1188 Output callgraph information on a per-file basis with decorations.
1191 Common Joined RejectNegative Var(common_deferred_options) Defer
1192 -fcall-saved-<register> Mark <register> as being preserved across functions.
1195 Common Joined RejectNegative Var(common_deferred_options) Defer
1196 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1198 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1199 ; be saved across function calls, if that produces overall better code.
1200 ; Optional now, so people can test it.
1202 Common Var(flag_caller_saves) Optimization
1203 Save registers around function calls.
1207 This switch is deprecated; do not use.
1210 Common Var(flag_check_new)
1211 Check the return value of new in C++.
1214 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1215 Perform internal consistency checkings.
1218 Common Joined RejectNegative UInteger Var(flag_checking)
1219 Perform internal consistency checkings.
1222 Common Var(common_deferred_options) Defer
1223 For -f*-prefix-map= options compare canonicalized pathnames rather than just strings.
1226 Common Var(flag_code_hoisting) Optimization
1227 Enable code hoisting.
1229 fcombine-stack-adjustments
1230 Common Var(flag_combine_stack_adjustments) Optimization
1231 Looks for opportunities to reduce stack adjustments and stack references.
1234 Common Var(flag_no_common,0) Init(1)
1235 Put uninitialized globals in the common section.
1239 ; Converted by the driver to -fcompare-debug= options.
1242 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1243 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1245 fcompare-debug-second
1246 Common Driver RejectNegative Var(flag_compare_debug)
1247 Run only the second compilation of -fcompare-debug.
1250 Common Var(flag_compare_elim_after_reload) Optimization
1251 Perform comparison elimination after register allocation has finished.
1254 Common Var(flag_conserve_stack) Optimization
1255 Do not perform optimizations increasing noticeably stack usage.
1258 Common Var(flag_cprop_registers) Optimization
1259 Perform a register copy-propagation optimization pass.
1262 Common Var(flag_fold_mem_offsets) Init(1) Optimization
1263 Fold instructions calculating memory offsets to the memory access instruction if possible.
1266 Common Var(flag_crossjumping) Optimization
1267 Perform cross-jumping optimization.
1270 Common Var(flag_cse_follow_jumps) Optimization
1271 When running CSE, follow jumps to their targets.
1275 Does nothing. Preserved for backward compatibility.
1278 Common Var(flag_cx_limited_range) Optimization SetByCombined
1279 Omit range reduction step when performing complex division.
1282 Common Var(flag_cx_fortran_rules) Optimization
1283 Complex multiplication and division follow Fortran rules.
1286 Common Var(flag_data_sections)
1287 Place data items into their own section.
1290 Common Var(flag_dbg_cnt_list)
1291 List all available debugging counters with their limits and counts.
1294 Common RejectNegative Joined Var(common_deferred_options) Defer
1295 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1298 Common Joined RejectNegative Var(common_deferred_options) Defer
1299 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1302 Common Joined RejectNegative Var(common_deferred_options) Defer
1303 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1305 fdebug-types-section
1306 Common Var(flag_debug_types_section) Init(0)
1307 Output .debug_types section when using DWARF v4 debuginfo.
1309 ; Nonzero for -fdefer-pop: don't pop args after each function call
1310 ; instead save them up to pop many calls' args with one insns.
1312 Common Var(flag_defer_pop) Optimization
1313 Defer popping functions args from stack until later.
1316 Common Var(flag_delayed_branch) Optimization
1317 Attempt to fill delay slots of branch instructions.
1319 fdelete-dead-exceptions
1320 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1321 Delete dead instructions that may throw exceptions.
1323 fdelete-null-pointer-checks
1324 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1325 Delete useless null pointer checks.
1327 fdevirtualize-at-ltrans
1328 Common Var(flag_ltrans_devirtualize)
1329 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1331 fdevirtualize-speculatively
1332 Common Var(flag_devirtualize_speculatively) Optimization
1333 Perform speculative devirtualization.
1336 Common Var(flag_devirtualize) Optimization
1337 Try to convert virtual calls to direct ones.
1339 fdiagnostics-show-location=
1340 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1341 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1343 ; Required for these enum values.
1348 Name(diagnostic_prefixing_rule) Type(int)
1351 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1354 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1356 fdiagnostics-show-caret
1357 Common Var(flag_diagnostics_show_caret) Init(1)
1358 Show the source line with a caret indicating the column.
1360 fdiagnostics-show-labels
1361 Common Var(flag_diagnostics_show_labels) Init(1)
1362 Show labels annotating ranges of source code when showing source.
1364 fdiagnostics-show-line-numbers
1365 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1366 Show line numbers in the left margin when showing source.
1369 Common Alias(fdiagnostics-color=,always,never)
1373 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1374 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1376 ; Required for these enum values.
1381 Name(diagnostic_color_rule) Type(int)
1384 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1387 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1390 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1392 fdiagnostics-json-formatting
1393 Common Var(flag_diagnostics_json_formatting) Init(1)
1394 Enable formatting of JSON output.
1397 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1398 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1400 ; Required for these enum values.
1405 Name(diagnostic_url_rule) Type(int)
1408 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1411 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1414 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1416 fdiagnostics-column-unit=
1417 Common Joined RejectNegative Enum(diagnostics_column_unit)
1418 -fdiagnostics-column-unit=[display|byte] Select whether column numbers are output as display columns (default) or raw bytes.
1420 fdiagnostics-column-origin=
1421 Common Joined RejectNegative UInteger
1422 -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.
1424 fdiagnostics-format=
1425 Common Joined RejectNegative Enum(diagnostics_output_format)
1426 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file] Select output format.
1428 fdiagnostics-escape-format=
1429 Common Joined RejectNegative Enum(diagnostics_escape_format)
1430 -fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1432 ; Required for these enum values.
1437 Name(diagnostics_column_unit) Type(int)
1440 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1443 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1446 Name(diagnostics_escape_format) Type(int)
1449 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1452 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1455 Name(diagnostics_output_format) Type(int)
1458 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1461 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1464 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1467 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1470 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1473 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1475 fdiagnostics-parseable-fixits
1476 Common Var(flag_diagnostics_parseable_fixits)
1477 Print fix-it hints in machine-readable form.
1479 fdiagnostics-generate-patch
1480 Common Var(flag_diagnostics_generate_patch)
1481 Print fix-it hints to stderr in unified diff format.
1483 fdiagnostics-show-option
1484 Common Var(flag_diagnostics_show_option) Init(1)
1485 Amend appropriate diagnostic messages with the command line option that controls them.
1487 fdiagnostics-show-cwe
1488 Common Var(flag_diagnostics_show_cwe) Init(1)
1489 Print CWE identifiers for diagnostic messages, where available.
1491 fdiagnostics-show-rules
1492 Common Var(flag_diagnostics_show_rules) Init(1)
1493 Print any rules associated with diagnostic messages.
1495 fdiagnostics-path-format=
1496 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1497 Specify how to print any control-flow path associated with a diagnostic.
1499 fdiagnostics-plain-output
1500 Driver Common RejectNegative
1501 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1504 Common Joined RejectNegative UInteger
1505 -ftabstop=<number> Distance between tab stops for column reporting.
1508 Name(diagnostic_path_format) Type(int)
1511 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1514 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1517 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1519 fdiagnostics-show-path-depths
1520 Common Var(flag_diagnostics_show_path_depths) Init(0)
1521 Show stack depths of events in paths.
1523 fdiagnostics-text-art-charset=
1524 Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1525 -fdiagnostics-text-art-charset=[none|ascii|unicode|emoji] Determine which characters to use in text arg diagrams.
1528 Name(diagnostic_text_art_charset) Type(int)
1531 Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
1534 Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
1537 Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
1540 Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1542 fdiagnostics-minimum-margin-width=
1543 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1544 Set minimum width of left margin of source code when showing source.
1547 Common Joined RejectNegative Var(common_deferred_options) Defer
1548 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 Disable an optimization pass.
1551 Common Joined RejectNegative Var(common_deferred_options) Defer
1552 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 Enable an optimization pass.
1555 Common Joined RejectNegative Var(common_deferred_options) Defer
1556 -fdump-<type> Dump various compiler internals to a file.
1559 Driver RejectNegative
1562 Common RejectNegative Joined Var(flag_dump_final_insns)
1563 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1566 Common RejectNegative Joined Var(flag_dump_go_spec)
1567 -fdump-go-spec=filename Write all declarations to file as Go code.
1570 Common Var(flag_dump_noaddr)
1571 Suppress output of addresses in debugging dumps.
1574 Common Driver Var(flag_report_bug)
1575 Collect and dump debug information into temporary file if ICE in C/C++
1578 fdump-internal-locations
1579 Common Var(flag_dump_locations) Init(0)
1580 Dump detailed information on GCC's internal representation of source code locations.
1583 Common Var(flag_dump_passes) Init(0)
1584 Dump optimization passes.
1587 Common Var(flag_dump_unnumbered)
1588 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1590 fdump-unnumbered-links
1591 Common Var(flag_dump_unnumbered_links)
1592 Suppress output of previous and next insn numbers in debugging dumps.
1595 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1596 Enable CFI tables via GAS assembler directives.
1599 Common Var(flag_early_inlining) Init(1) Optimization
1600 Perform early inlining.
1602 feliminate-dwarf2-dups
1604 Does nothing. Preserved for backward compatibility.
1607 Common Var(flag_ipa_sra) Init(0) Optimization
1608 Perform interprocedural reduction of aggregates.
1610 feliminate-unused-debug-symbols
1611 Common Var(flag_debug_only_used_symbols) Init(1)
1612 Perform unused symbol elimination in debug info.
1614 feliminate-unused-debug-types
1615 Common Var(flag_eliminate_unused_debug_types) Init(1)
1616 Perform unused type elimination in debug info.
1618 femit-class-debug-always
1619 Common Var(flag_emit_class_debug_always) Init(0)
1620 Do not suppress C++ class debug information.
1623 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1624 Enable exception handling.
1626 fexpensive-optimizations
1627 Common Var(flag_expensive_optimizations) Optimization
1628 Perform a number of minor, expensive optimizations.
1631 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1632 -fexcess-precision=[fast|standard|16] Specify handling of excess floating-point precision.
1635 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1638 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1641 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1644 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1646 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1647 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1648 fpermitted-flt-eval-methods=
1649 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1650 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1653 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)
1656 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1659 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1665 Common Var(flag_fat_lto_objects)
1666 Output lto objects containing both the intermediate language and binary output.
1669 Common Var(flag_finite_math_only) Optimization SetByCombined
1670 Assume no NaNs or infinities are generated.
1673 Common Var(flag_finite_loops) Optimization Init(0)
1674 Assume that loops with an exit will terminate and not loop indefinitely.
1677 Common Joined RejectNegative Var(common_deferred_options) Defer
1678 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1681 Common Var(flag_float_store) Optimization
1682 Don't allocate floats and doubles in extended-precision registers.
1686 Does nothing. Preserved for backward compatibility.
1689 Common Var(flag_forward_propagate) Optimization
1690 Perform a forward propagation pass on RTL.
1693 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1694 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1697 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1700 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1703 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_ON)
1706 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1708 ffp-int-builtin-inexact
1709 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1710 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1712 ; Nonzero means don't put addresses of constant functions in registers.
1713 ; Used for compiling the Unix kernel, where strange substitutions are
1714 ; done on the assembly output.
1716 Common Var(flag_no_function_cse,0) Optimization
1717 Allow function addresses to be held in registers.
1720 Common Var(flag_function_sections)
1721 Place each function into its own section.
1724 Common Var(flag_gcse) Optimization
1725 Perform global common subexpression elimination.
1728 Common Var(flag_gcse_lm) Init(1) Optimization
1729 Perform enhanced load motion during global common subexpression elimination.
1732 Common Var(flag_gcse_sm) Init(0) Optimization
1733 Perform store motion after global common subexpression elimination.
1736 Common Var(flag_gcse_las) Init(0) Optimization
1737 Perform redundant load after store elimination in global common subexpression
1741 Common Var(flag_gcse_after_reload) Optimization
1742 Perform global common subexpression elimination after register allocation has
1746 Name(dwarf_gnat_encodings) Type(int)
1749 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1752 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1755 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1758 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1759 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1761 ; This option is not documented yet as its semantics will change.
1763 Common Var(flag_graphite) Optimization
1764 Enable in and out of Graphite representation.
1767 Common Var(flag_graphite_identity) Optimization
1768 Enable Graphite Identity transformation.
1770 fhoist-adjacent-loads
1771 Common Var(flag_hoist_adjacent_loads) Optimization
1772 Enable hoisting adjacent loads to encourage generating conditional move
1776 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1777 ; Always keep a pointer to a live memory block
1780 Common Var(flag_large_source_files) Init(0)
1781 Improve GCC's ability to track column numbers in large source files,
1782 at the expense of slower compilation.
1784 floop-parallelize-all
1785 Common Var(flag_loop_parallelize_all) Optimization
1786 Mark all loops as parallel.
1789 Common Alias(floop-nest-optimize)
1790 Enable loop nest transforms. Same as -floop-nest-optimize.
1793 Common Var(flag_loop_interchange) Optimization
1794 Enable loop interchange on trees.
1797 Common Alias(floop-nest-optimize)
1798 Enable loop nest transforms. Same as -floop-nest-optimize.
1800 floop-unroll-and-jam
1801 Common Var(flag_unroll_jam) Optimization
1802 Perform unroll-and-jam on loops.
1806 Enable support for GNU transactional memory.
1809 Common Var(flag_gnu_unique) Init(1)
1810 Use STB_GNU_UNIQUE if supported by the assembler.
1814 Does nothing. Preserved for backward compatibility.
1817 Common Var(flag_loop_nest_optimize) Optimization
1818 Enable the loop nest optimizer.
1820 fstrict-volatile-bitfields
1821 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1822 Force bitfield accesses to match their type width.
1825 Common Var(flag_store_merging) Optimization
1826 Merge adjacent stores.
1828 fguess-branch-probability
1829 Common Var(flag_guess_branch_prob) Optimization
1830 Enable guessing of branch probabilities.
1833 Common Driver Var(flag_hardened)
1834 Enable various security-relevant flags.
1837 Common Var(flag_harden_compares) Optimization
1838 Harden conditionals not used in branches, checking reversed conditions.
1840 fharden-conditional-branches
1841 Common Var(flag_harden_conditional_branches) Optimization
1842 Harden conditional branches by checking reversed conditions.
1844 fharden-control-flow-redundancy
1845 Common Var(flag_harden_control_flow_redundancy) Optimization
1846 Harden control flow by recording and checking execution paths.
1849 Common Var(flag_harden_control_flow_redundancy_skip_leaf) Optimization
1850 Disable CFR in leaf functions.
1852 fhardcfr-check-returning-calls
1853 Common Var(flag_harden_control_flow_redundancy_check_returning_calls) Init(-1) Optimization
1854 Check CFR execution paths also before calls followed by returns of their results.
1856 fhardcfr-check-exceptions
1857 Common Var(flag_harden_control_flow_redundancy_check_exceptions) Init(-1) Optimization
1858 Check CFR execution paths also when exiting a function through an exception.
1860 fhardcfr-check-noreturn-calls=
1861 Common Joined RejectNegative Enum(hardcfr_check_noreturn_calls) Var(flag_harden_control_flow_redundancy_check_noreturn) Init(HCFRNR_UNSPECIFIED) Optimization
1862 -fhardcfr-check-noreturn-calls=[always|no-xthrow|nothrow|never] Check CFR execution paths also before calling noreturn functions.
1865 Name(hardcfr_check_noreturn_calls) Type(enum hardcfr_noret) UnknownError(unknown hardcfr noreturn checking level %qs)
1868 Enum(hardcfr_check_noreturn_calls) String(never) Value(HCFRNR_NEVER)
1871 Enum(hardcfr_check_noreturn_calls) String(nothrow) Value(HCFRNR_NOTHROW)
1874 Enum(hardcfr_check_noreturn_calls) String(no-xthrow) Value(HCFRNR_NO_XTHROW)
1877 Enum(hardcfr_check_noreturn_calls) String(always) Value(HCFRNR_ALWAYS)
1879 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1880 ; Generate position-independent code for executables if possible
1881 ; On SVR4 targets, it also controls whether or not to emit a
1882 ; string identifying the compiler.
1884 Common Var(flag_no_ident,0)
1885 Process #ident directives.
1888 Common Var(flag_if_conversion) Optimization
1889 Perform conversion of conditional jumps to branchless equivalents.
1892 Common Var(flag_if_conversion2) Optimization
1893 Perform conversion of conditional jumps to conditional execution.
1896 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1897 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1900 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1903 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1906 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1909 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1911 ftree-loop-if-convert
1912 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1913 Convert conditional jumps in innermost loops to branchless equivalents.
1915 ftree-loop-if-convert-stores
1917 Does nothing. Preserved for backward compatibility.
1919 ; -finhibit-size-directive inhibits output of .size for ELF.
1920 ; This is used only for compiling crtstuff.c,
1921 ; and it may be extended to other effects
1922 ; needed for crtstuff.c on other systems.
1923 finhibit-size-directive
1924 Common Var(flag_inhibit_size_directive)
1925 Do not generate .size directives.
1928 Common Var(flag_indirect_inlining) Optimization
1929 Perform indirect inlining.
1931 ; General flag to enable inlining. Specifying -fno-inline will disable
1932 ; all inlining apart from always-inline functions.
1934 Common Var(flag_no_inline,0) Init(0) Optimization
1935 Enable inlining of function declared \"inline\", disabling disables all inlining.
1937 finline-small-functions
1938 Common Var(flag_inline_small_functions) Optimization
1939 Integrate functions into their callers when code size is known not to grow.
1942 Common Var(flag_inline_functions) Optimization
1943 Integrate functions not declared \"inline\" into their callers when profitable.
1945 finline-functions-called-once
1946 Common Var(flag_inline_functions_called_once) Optimization
1947 Integrate functions only required by their single caller.
1950 Common RejectNegative Joined Alias(finline-limit=)
1953 Common RejectNegative Joined UInteger
1954 -finline-limit=<number> Limit the size of inlined functions to <number>.
1957 Common Var(flag_inline_atomics) Init(1) Optimization
1958 Inline __atomic operations when a lock free instruction sequence is available.
1961 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_ALL) Enum(ilsop_fn) Init(ILSOP_NONE) Optimization Undocumented
1963 fno-inline-stringops
1964 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_NONE) Enum(ilsop_fn) Optimization Undocumented
1967 Common Joined Var(flag_inline_stringops) EnumSet Enum(ilsop_fn) Optimization
1968 -finline-stringops[=memcmp|memcpy|memmove|memset]
1969 Expand supported mem/str operations inline, even if against optimization.
1972 Name(ilsop_fn) Type(enum ilsop_fn) UnknownError(unavailable stringop for inlining %qs)
1974 ; This is not part of any set.
1976 ; Enum(ilsop_fn) String(none) Value(ILSOP_NONE)
1979 Enum(ilsop_fn) String(memcmp) Value(ILSOP_MEMCMP) Set(1)
1982 Enum(ilsop_fn) String(memcpy) Value(ILSOP_MEMCPY) Set(2)
1985 Enum(ilsop_fn) String(memmove) Value(ILSOP_MEMMOVE) Set(3)
1988 Enum(ilsop_fn) String(memset) Value(ILSOP_MEMSET) Set(4)
1990 ; This is not part of any set either.
1992 ; Enum(ilsop_fn) String(all) Value(ILSOP_ALL)
1995 Common RejectNegative Alias(fcf-protection=,full)
1998 Common Joined RejectNegative Enum(cf_protection_level) EnumSet Var(flag_cf_protection) Init(CF_NONE)
1999 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
2000 instructions have valid targets.
2003 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
2006 Enum(cf_protection_level) String(full) Value(CF_FULL) Set(1)
2009 Enum(cf_protection_level) String(branch) Value(CF_BRANCH) Set(2)
2012 Enum(cf_protection_level) String(return) Value(CF_RETURN) Set(3)
2015 Enum(cf_protection_level) String(check) Value(CF_CHECK) Set(4)
2018 Enum(cf_protection_level) String(none) Value(CF_NONE) Set(1)
2020 finstrument-functions
2021 Common Var(flag_instrument_function_entry_exit,1)
2022 Instrument function entry and exit with profiling calls.
2024 finstrument-functions-once
2025 Common Var(flag_instrument_function_entry_exit,2)
2026 Instrument function entry and exit with profiling calls invoked once.
2028 finstrument-functions-exclude-function-list=
2029 Common RejectNegative Joined
2030 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
2032 finstrument-functions-exclude-file-list=
2033 Common RejectNegative Joined
2034 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
2037 Common Var(flag_ipa_cp) Optimization
2038 Perform interprocedural constant propagation.
2041 Common Var(flag_ipa_cp_clone) Optimization
2042 Perform cloning to make Interprocedural constant propagation stronger.
2046 Does nothing. Preserved for backward compatibility.
2049 Common Var(flag_ipa_bit_cp) Optimization
2050 Perform interprocedural bitwise constant propagation.
2053 Common Var(flag_ipa_modref) Optimization
2054 Perform interprocedural modref analysis.
2057 Common Var(flag_ipa_profile) Init(0) Optimization
2058 Perform interprocedural profile propagation.
2061 Common Var(flag_ipa_pta) Init(0) Optimization
2062 Perform interprocedural points-to analysis.
2065 Common Var(flag_ipa_pure_const) Init(0) Optimization
2066 Discover pure and const functions.
2069 Common Var(flag_ipa_icf) Optimization
2070 Perform Identical Code Folding for functions and read-only variables.
2073 Common Var(flag_ipa_icf_functions) Optimization
2074 Perform Identical Code Folding for functions.
2077 Common Var(flag_ipa_icf_variables) Optimization
2078 Perform Identical Code Folding for variables.
2081 Common Var(flag_ipa_reference) Init(0) Optimization
2082 Discover read-only and non addressable static variables.
2084 fipa-reference-addressable
2085 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
2086 Discover read-only, write-only and non-addressable static variables.
2088 fipa-stack-alignment
2089 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
2090 Reduce stack alignment on call sites if possible.
2094 Does nothing. Preserved for backward compatibility.
2098 Does nothing. Preserved for backward compatibility.
2101 Common Var(flag_ipa_vrp) Optimization
2102 Perform IPA Value Range Propagation.
2105 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
2106 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
2108 fipa-strict-aliasing
2109 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
2110 Assume strict aliasing rules apply across (uninlined) function boundaries.
2113 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
2116 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2119 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2122 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2123 -fira-region=[one|all|mixed] Set regions for IRA.
2126 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2129 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2132 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2135 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2138 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2139 Use IRA based register pressure calculation
2140 in RTL hoist optimizations.
2143 Common Var(flag_ira_loop_pressure) Optimization
2144 Use IRA based register pressure calculation
2145 in RTL loop optimizations.
2147 fira-share-save-slots
2148 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2149 Share slots for saving different hard registers.
2151 fira-share-spill-slots
2152 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2153 Share stack slots for spilled pseudo-registers.
2156 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2157 -fira-verbose=<number> Control IRA's level of diagnostic messages.
2160 Common Var(flag_ivopts) Init(1) Optimization
2161 Optimize induction variables on trees.
2164 Common Var(flag_jump_tables) Init(1) Optimization
2165 Use jump tables for sufficiently large switch statements.
2168 Common Var(flag_bit_tests) Init(1) Optimization
2169 Use bit tests for sufficiently large switch statements.
2171 fkeep-inline-functions
2172 Common Var(flag_keep_inline_functions)
2173 Generate code for functions even if they are fully inlined.
2175 fkeep-static-functions
2176 Common Var(flag_keep_static_functions)
2177 Generate code for static functions even if they are never called.
2180 Common Var(flag_keep_static_consts) Init(1)
2181 Emit static const variables even if they are not used.
2184 Common Var(flag_leading_underscore) Init(-1)
2185 Give external symbols a leading underscore.
2189 Does nothing. Preserved for backward compatibility.
2192 Common Var(flag_lra_remat) Optimization
2193 Do CFG-sensitive rematerialization in LRA.
2197 Enable link-time optimization.
2200 Common RejectNegative Joined Var(flag_lto)
2201 Link-time optimization with number of parallel jobs or jobserver.
2204 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2207 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2210 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2213 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2216 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2219 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2222 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2223 Specify the algorithm to partition symbols and vars at linktime.
2225 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2226 flto-compression-level=
2227 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2228 Use zlib/zstd compression level <number> for IL.
2230 flto-odr-type-merging
2232 Does nothing. Preserved for backward compatibility.
2235 Common Var(flag_lto_report) Init(0)
2236 Report various link-time optimization statistics.
2239 Common Var(flag_lto_report_wpa) Init(0)
2240 Report various link-time optimization statistics for WPA only.
2243 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2244 Set errno after built-in math functions.
2247 Common Joined RejectNegative UInteger Var(flag_max_errors)
2248 -fmax-errors=<number> Maximum number of errors to report.
2251 Common Var(mem_report)
2252 Report on permanent memory allocation.
2255 Common Var(mem_report_wpa)
2256 Report on permanent memory allocation in WPA only.
2258 ; This will attempt to merge constant section constants, if 1 only
2259 ; string constants and constants from constant pool, if 2 also constant
2261 fmerge-all-constants
2262 Common Var(flag_merge_constants,2) Init(1)
2263 Attempt to merge identical constants and constant variables.
2266 Common Var(flag_merge_constants,1)
2267 Attempt to merge identical constants across compilation units.
2269 fmerge-debug-strings
2270 Common Var(flag_merge_debug_strings) Init(1)
2271 Attempt to merge identical debug strings across compilation units.
2274 Common RejectNegative Joined UInteger
2275 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
2277 fmin-function-alignment=
2278 Common Joined RejectNegative UInteger Var(flag_min_function_alignment) Optimization
2279 Align the start of every function.
2282 Common Var(flag_modulo_sched) Optimization
2283 Perform SMS based modulo scheduling before the first scheduling pass.
2285 fmodulo-sched-allow-regmoves
2286 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2287 Perform SMS based modulo scheduling with register moves allowed.
2289 fmove-loop-invariants
2290 Common Var(flag_move_loop_invariants) Optimization
2291 Move loop invariant computations out of loops.
2294 Common Var(flag_move_loop_stores) Optimization
2295 Move stores out of loops.
2298 Common Driver RejectNegative
2299 Building block for specs-based multilib-aware TFLAGS.
2302 Common Var(flag_dce) Init(1) Optimization
2303 Use the RTL dead code elimination pass.
2306 Common Var(flag_dse) Init(0) Optimization
2307 Use the RTL dead store elimination pass.
2309 freschedule-modulo-scheduled-loops
2310 Common Var(flag_resched_modulo_sched) Optimization
2311 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2313 fnon-call-exceptions
2314 Common Var(flag_non_call_exceptions) Optimization
2315 Support synchronous non-call exceptions.
2318 Driver Joined MissingArgError(targets missing after %qs)
2321 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2322 -foffload-options=<targets>=<options> Specify options for the offloading targets.
2325 Common Joined RejectNegative Enum(offload_abi)
2326 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2329 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2332 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2335 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2338 Common Var(flag_omit_frame_pointer) Optimization
2339 When possible do not generate stack frames.
2341 fopenmp-target-simd-clone
2342 Common Alias(fopenmp-target-simd-clone=,any,none)
2344 fopenmp-target-simd-clone=
2345 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2346 Generate SIMD clones for functions with the OpenMP declare target directive.
2349 Name(target_simd_clone_device) Type(int)
2352 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2355 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2358 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2361 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2364 Common Var(flag_opt_info) Optimization
2365 Enable all optimization info dumps on stderr.
2368 Common Joined RejectNegative Var(common_deferred_options) Defer
2369 -fopt-info[-<type>=filename] Dump compiler optimization details.
2371 fsave-optimization-record
2372 Common Var(flag_save_optimization_record) Optimization
2373 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2375 foptimize-register-move
2377 Does nothing. Preserved for backward compatibility.
2379 foptimize-sibling-calls
2380 Common Var(flag_optimize_sibling_calls) Optimization
2381 Optimize sibling and tail recursive calls.
2384 Common Var(flag_partial_inlining) Optimization
2385 Perform partial inlining.
2388 Common Var(pre_ipa_mem_report)
2389 Report on memory allocation before interprocedural optimization.
2391 fpost-ipa-mem-report
2392 Common Var(post_ipa_mem_report)
2393 Report on memory allocation before interprocedural optimization.
2396 Common Var(flag_pack_struct) Optimization
2397 Pack structure members together without holes.
2400 Common RejectNegative Joined UInteger Optimization
2401 -fpack-struct=<number> Set initial maximum structure member alignment.
2404 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2405 Return small aggregates in memory, not registers.
2408 Common Var(flag_peel_loops) Optimization
2409 Perform loop peeling.
2412 Common Var(flag_no_peephole,0) Optimization
2413 Enable machine specific peephole optimizations.
2416 Common Var(flag_peephole2) Optimization
2417 Enable an RTL peephole pass before sched2.
2420 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2421 Generate position-independent code if possible (large mode).
2424 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2425 Generate position-independent code for executables if possible (large mode).
2428 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2429 Generate position-independent code if possible (small mode).
2432 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2433 Generate position-independent code for executables if possible (small mode).
2436 Common Var(flag_plt) Init(1) Optimization
2437 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2440 Common Joined RejectNegative Var(common_deferred_options) Defer
2441 Specify a plugin to load.
2444 Common Joined RejectNegative Var(common_deferred_options) Defer
2445 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2447 fpredictive-commoning
2448 Common Var(flag_predictive_commoning) Optimization
2449 Run predictive commoning optimization.
2451 fprefetch-loop-arrays
2452 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2453 Generate prefetch instructions, if available, for arrays in loops.
2456 Common Var(profile_flag)
2457 Enable basic program profiling code.
2460 Common Var(profile_abs_path_flag)
2461 Generate absolute source path names for gcov.
2464 Common Var(profile_arc_flag)
2465 Insert arc-based program profiling code.
2468 Common Joined RejectNegative Var(profile_data_prefix)
2469 Set the top-level directory for storing the profile data.
2470 The default is 'pwd'.
2473 Common Joined RejectNegative Var(profile_note_location)
2474 Select the name for storing the profile note file.
2477 Common Var(flag_profile_correction)
2478 Enable correction of flow inconsistent profile data input.
2481 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2482 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2484 fprofile-filter-files=
2485 Common Joined RejectNegative Var(flag_profile_filter_files)
2486 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2488 fprofile-exclude-files=
2489 Common Joined RejectNegative Var(flag_profile_exclude_files)
2490 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2493 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2496 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2499 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2502 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2504 fprofile-reproducible=
2505 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2506 -fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate.
2509 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2512 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2515 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2518 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2520 fprofile-prefix-path=
2521 Common Joined RejectNegative Var(profile_prefix_path)
2522 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2524 fprofile-prefix-map=
2525 Common Joined RejectNegative Var(common_deferred_options) Defer
2526 -fprofile-prefix-map=<old>=<new> Map one directory name to another in GCOV coverage result.
2530 Enable common options for generating profile info for profile feedback directed optimizations.
2533 Common Joined RejectNegative
2534 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2536 fprofile-info-section
2537 Common RejectNegative
2538 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2540 fprofile-info-section=
2541 Common Joined RejectNegative Var(profile_info_section)
2542 Register the profile information in the specified section instead of using a constructor/destructor.
2544 fprofile-partial-training
2545 Common Var(flag_profile_partial_training) Optimization
2546 Do not assume that functions never executed during the train run are cold.
2549 Common Var(flag_profile_use)
2550 Enable common options for performing profile feedback directed optimizations.
2553 Common Joined RejectNegative
2554 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2557 Common Var(flag_profile_values)
2558 Insert code to profile values of expressions.
2561 Common Var(profile_report)
2562 Report on consistency of profile.
2564 fprofile-reorder-functions
2565 Common Var(flag_profile_reorder_functions) Optimization
2566 Enable function reordering that improves code placement.
2568 fpatchable-function-entry=
2569 Common Var(flag_patchable_function_entry) Joined Optimization
2570 Insert NOP instructions at each function entry.
2573 Common Var(common_deferred_options) Defer
2576 Common Joined RejectNegative Var(common_deferred_options) Defer
2577 -frandom-seed=<string> Make compile reproducible using <string>.
2579 ; This switch causes the command line that was used to create an
2580 ; object file to be recorded into the object file. The exact format
2581 ; of this recording is target and binary file format dependent.
2582 ; It is related to the -fverbose-asm switch, but that switch only
2583 ; records information in the assembler output file as comments, so
2584 ; they never reach the object file.
2585 frecord-gcc-switches
2586 Common Var(flag_record_gcc_switches)
2587 Record gcc command line switches in the object file.
2590 Common Var(flag_pcc_struct_return,0) Optimization
2591 Return small aggregates in registers.
2595 Does nothing. Preserved for backward compatibility.
2598 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2599 Tell DSE that the storage for a C++ object is dead when the constructor
2600 starts and when the destructor finishes.
2603 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2605 flimit-function-alignment
2606 Common Var(flag_limit_function_alignment) Optimization Init(0)
2609 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2612 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2613 -flive-patching=[inline-only-static|inline-clone] Control IPA
2614 optimizations to provide a safe compilation for live-patching. At the same
2615 time, provides multiple-level control on the enabled IPA optimizations.
2618 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2621 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2624 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2627 Common Var(flag_allocation_dce) Init(1) Optimization
2628 Tell DCE to remove unused C++ allocations.
2630 flive-range-shrinkage
2631 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2632 Relief of register pressure through live range shrinkage.
2635 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2636 Perform a register renaming optimization pass.
2639 Common Var(flag_schedule_fusion) Init(2) Optimization
2640 Perform a target dependent instruction fusion optimization pass.
2643 Common Var(flag_reorder_blocks) Optimization
2644 Reorder basic blocks to improve code placement.
2646 freorder-blocks-algorithm=
2647 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2648 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2651 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2654 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2657 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2659 freorder-blocks-and-partition
2660 Common Var(flag_reorder_blocks_and_partition) Optimization
2661 Reorder basic blocks and partition into hot and cold sections.
2664 Common Var(flag_reorder_functions) Optimization
2665 Reorder functions to improve code placement.
2667 frerun-cse-after-loop
2668 Common Var(flag_rerun_cse_after_loop) Optimization
2669 Add a common subexpression elimination pass after loop optimizations.
2673 Does nothing. Preserved for backward compatibility.
2676 Common Var(flag_rounding_math) Optimization SetByCombined
2677 Disable optimizations that assume default FP rounding behavior.
2680 Common Var(flag_schedule_interblock) Init(1) Optimization
2681 Enable scheduling across basic blocks.
2684 Common Var(flag_sched_pressure) Init(0) Optimization
2685 Enable register pressure sensitive insn scheduling.
2688 Common Var(flag_schedule_speculative) Init(1) Optimization
2689 Allow speculative motion of non-loads.
2692 Common Var(flag_schedule_speculative_load) Optimization
2693 Allow speculative motion of some loads.
2695 fsched-spec-load-dangerous
2696 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2697 Allow speculative motion of more loads.
2700 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2701 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2703 fsched2-use-superblocks
2704 Common Var(flag_sched2_use_superblocks) Optimization
2705 If scheduling post reload, do superblock scheduling.
2709 Does nothing. Preserved for backward compatibility.
2712 Common Var(flag_schedule_insns) Optimization
2713 Reschedule instructions before register allocation.
2716 Common Var(flag_schedule_insns_after_reload) Optimization
2717 Reschedule instructions after register allocation.
2719 ; This flag should be on when a target implements non-trivial
2720 ; scheduling hooks, maybe saving some information for its own sake.
2721 ; On IA64, for example, this is used for correct bundling.
2722 fselective-scheduling
2723 Common Var(flag_selective_scheduling) Optimization
2724 Schedule instructions using selective scheduling algorithm.
2726 fselective-scheduling2
2727 Common Var(flag_selective_scheduling2) Optimization
2728 Run selective scheduling after reload.
2731 Common Undocumented Joined Var(flag_self_test)
2732 Run self-tests, using the given path to locate test files.
2734 fsel-sched-pipelining
2735 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2736 Perform software pipelining of inner loops during selective scheduling.
2738 fsel-sched-pipelining-outer-loops
2739 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2740 Perform software pipelining of outer loops during selective scheduling.
2742 fsel-sched-reschedule-pipelined
2743 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2744 Reschedule pipelined regions without pipelining.
2746 fsemantic-interposition
2747 Common Var(flag_semantic_interposition) Init(1) Optimization
2748 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2750 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2751 ; of stalled insns into the ready list.
2752 fsched-stalled-insns
2753 Common Var(flag_sched_stalled_insns) Optimization UInteger
2754 Allow premature scheduling of queued insns.
2756 fsched-stalled-insns=
2757 Common RejectNegative Joined UInteger Optimization
2758 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2760 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2761 ; be examined for a dependency on a stalled insn that is candidate for
2762 ; premature removal from the queue of stalled insns into the ready list (has
2763 ; an effect only if the flag 'sched_stalled_insns' is set).
2764 fsched-stalled-insns-dep
2765 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2766 Set dependence distance checking in premature scheduling of queued insns.
2768 fsched-stalled-insns-dep=
2769 Common RejectNegative Joined UInteger Optimization
2770 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2772 fsched-group-heuristic
2773 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2774 Enable the group heuristic in the scheduler.
2776 fsched-critical-path-heuristic
2777 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2778 Enable the critical path heuristic in the scheduler.
2780 fsched-spec-insn-heuristic
2781 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2782 Enable the speculative instruction heuristic in the scheduler.
2784 fsched-rank-heuristic
2785 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2786 Enable the rank heuristic in the scheduler.
2788 fsched-last-insn-heuristic
2789 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2790 Enable the last instruction heuristic in the scheduler.
2792 fsched-dep-count-heuristic
2793 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2794 Enable the dependent count heuristic in the scheduler.
2797 Common Var(flag_section_anchors) Optimization
2798 Access data in the same section from shared anchor points.
2802 Does nothing. Preserved for backward compatibility.
2806 Does nothing. Preserved for backward compatibility.
2809 Common Var(flag_ree) Init(0) Optimization
2810 Turn on Redundant Extensions Elimination pass.
2813 Common Var(flag_show_column) Init(1)
2814 Show column numbers in diagnostics, when available. Default on.
2817 Common Var(flag_shrink_wrap) Optimization
2818 Emit function prologues only before parts of the function that need it,
2819 rather than at the top of the function.
2821 fshrink-wrap-separate
2822 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2823 Shrink-wrap parts of the prologue and epilogue separately.
2826 Common Var(flag_signaling_nans) Optimization SetByCombined
2827 Disable optimizations observable by IEEE signaling NaNs.
2830 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2831 Disable floating point optimizations that ignore the IEEE signedness of zero.
2833 fsingle-precision-constant
2834 Common Var(flag_single_precision_constant) Optimization
2835 Convert floating point constants to single precision constants.
2837 fsplit-ivs-in-unroller
2838 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2839 Split lifetimes of induction variables when loops are unrolled.
2842 Common Var(flag_split_stack) Init(-1)
2843 Generate discontiguous stack frames.
2846 Common Var(flag_split_wide_types) Optimization
2847 Split wide types into independent registers.
2849 fsplit-wide-types-early
2850 Common Var(flag_split_wide_types_early) Optimization
2851 Split wide types into independent registers earlier.
2854 Common Var(flag_ssa_backprop) Init(1) Optimization
2855 Enable backward propagation of use properties at the SSA level.
2858 Common Var(flag_ssa_phiopt) Optimization
2859 Optimize conditional patterns using SSA PHI nodes.
2862 Common Var(flag_stdarg_opt) Init(1) Optimization
2863 Optimize amount of stdarg registers saved to stack at start of function.
2865 fvariable-expansion-in-unroller
2866 Common Var(flag_variable_expansion_in_unroller) Optimization
2867 Apply variable expansion when loops are unrolled.
2870 Common RejectNegative Joined Optimization
2871 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2874 Common Alias(fstack-check=, specific, no)
2875 Insert stack checking code into the program. Same as -fstack-check=specific.
2877 fstack-clash-protection
2878 Common Var(flag_stack_clash_protection) Optimization
2879 Insert code to probe each page of stack space as it is allocated to protect
2880 from stack-clash style attacks.
2883 Common Var(common_deferred_options) Defer
2885 fstack-limit-register=
2886 Common RejectNegative Joined Var(common_deferred_options) Defer
2887 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2889 fstack-limit-symbol=
2890 Common RejectNegative Joined Var(common_deferred_options) Defer
2891 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2894 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2895 Use propolice as a stack protection method.
2897 fstack-protector-all
2898 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2899 Use a stack protection method for every function.
2901 fstack-protector-strong
2902 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2903 Use a smart stack protection method for certain functions.
2905 fstack-protector-explicit
2906 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2907 Use stack protection method only for functions with the stack_protect attribute.
2910 Common RejectNegative Var(flag_stack_usage)
2911 Output stack usage information on a per-function basis.
2915 Does nothing. Preserved for backward compatibility.
2917 ; Nonzero if we should do (language-dependent) alias analysis.
2918 ; Typically, this analysis will assume that expressions of certain
2919 ; types do not alias expressions of certain other types. Only used
2920 ; if alias analysis (in general) is enabled.
2922 Common Var(flag_strict_aliasing) Optimization
2923 Assume strict aliasing rules apply.
2927 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2930 Common RejectNegative Var(flag_strub, 0)
2931 Disable stack scrub entirely, disregarding strub attributes.
2934 Common RejectNegative Var(flag_strub, -4)
2935 Enable stack scrub as per attributes, with strict call checking.
2937 ; If any strub-enabling attribute is seen when the default or strict
2938 ; initializer values are in effect, flag_strub is bumped up by 2. The
2939 ; scrub mode gate function will then bump these initializer values to
2940 ; 0 if no strub-enabling attribute is seen. This minimizes the strub
2943 Common RejectNegative Var(flag_strub, -3) Init(-3)
2944 Restore default strub mode: as per attributes, with relaxed checking.
2947 Common RejectNegative Var(flag_strub, 3)
2948 Enable stack scrubbing for all viable functions.
2951 Common RejectNegative Var(flag_strub, 1)
2952 Enable at-calls stack scrubbing for all viable functions.
2955 Common RejectNegative Var(flag_strub, 2)
2956 Enable internal stack scrubbing for all viable functions.
2959 Common Var(flag_sync_libcalls) Init(1)
2960 Implement __atomic operations via libcalls to legacy __sync functions.
2963 Common Var(flag_syntax_only)
2964 Check for syntax errors, then stop.
2967 Common Var(flag_test_coverage)
2968 Create data files needed by \"gcov\".
2971 Common Var(flag_thread_jumps) Optimization
2972 Perform jump threading optimizations.
2975 Common Var(time_report)
2976 Report the time taken by each compiler pass.
2978 ftime-report-details
2979 Common Var(time_report_details)
2980 Record times taken by sub-phases separately.
2983 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2984 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2987 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2990 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2993 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2996 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2999 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
3002 Common Var(flag_toplevel_reorder) Init(2) Optimization
3003 Reorder top level functions, variables, and asms.
3006 Common Var(flag_tracer) Optimization
3007 Perform superblock formation via tail duplication.
3010 Common Var(flag_trampolines) Init(HEAP_TRAMPOLINES_INIT)
3011 For targets that normally need trampolines for nested functions, always
3012 generate them instead of using descriptors.
3015 Common Joined RejectNegative Enum(trampoline_impl) Var(flag_trampoline_impl) Init(HEAP_TRAMPOLINES_INIT ? TRAMPOLINE_IMPL_HEAP : TRAMPOLINE_IMPL_STACK)
3016 Whether trampolines are generated in executable memory rather than
3020 Name(trampoline_impl) Type(enum trampoline_impl) UnknownError(unknown trampoline implementation %qs)
3023 Enum(trampoline_impl) String(stack) Value(TRAMPOLINE_IMPL_STACK)
3026 Enum(trampoline_impl) String(heap) Value(TRAMPOLINE_IMPL_HEAP)
3029 ; Zero means that floating-point math operations cannot generate a
3030 ; (user-visible) trap. This is the case, for example, in nonstop
3031 ; IEEE 754 arithmetic.
3033 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
3034 Assume floating-point operations can trap.
3037 Common Var(flag_trapv) Optimization
3038 Trap for signed overflow in addition, subtraction and multiplication.
3041 Common Var(flag_tree_ccp) Optimization
3042 Enable SSA-CCP optimization on trees.
3045 Common Var(flag_tree_bit_ccp) Optimization
3046 Enable SSA-BIT-CCP optimization on trees.
3050 Does nothing. Preserved for backward compatibility.
3053 Common Var(flag_tree_ch) Optimization
3054 Enable loop header copying on trees.
3056 ftree-coalesce-inlined-vars
3057 Common Ignore RejectNegative
3058 Does nothing. Preserved for backward compatibility.
3061 Common Var(flag_tree_coalesce_vars) Optimization
3062 Enable SSA coalescing of user variables.
3066 Does nothing. Preserved for backward compatibility.
3069 Common Var(flag_tree_copy_prop) Optimization
3070 Enable copy propagation on trees.
3072 ftree-store-copy-prop
3074 Does nothing. Preserved for backward compatibility.
3077 Common Var(flag_tree_cselim) Optimization
3078 Transform condition stores into unconditional ones.
3080 ftree-switch-conversion
3081 Common Var(flag_tree_switch_conversion) Optimization
3082 Perform conversions of switch initializations.
3085 Common Var(flag_tree_dce) Optimization
3086 Enable SSA dead code elimination optimization on trees.
3088 ftree-dominator-opts
3089 Common Var(flag_tree_dom) Optimization
3090 Enable dominator optimizations.
3093 Common Var(flag_tree_tail_merge) Optimization
3094 Enable tail merging on trees.
3097 Common Var(flag_tree_dse) Optimization
3098 Enable dead store elimination.
3101 Common Var(flag_tree_forwprop) Init(1) Optimization
3102 Enable forward propagation on trees.
3105 Common Var(flag_tree_fre) Optimization
3106 Enable Full Redundancy Elimination (FRE) on trees.
3109 Common Var(flag_optimize_strlen) Optimization
3110 Enable string length optimizations on trees.
3112 fisolate-erroneous-paths-dereference
3113 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
3114 Detect paths that trigger erroneous or undefined behavior due to
3115 dereferencing a null pointer. Isolate those paths from the main control
3116 flow and turn the statement with erroneous or undefined behavior into a trap.
3118 fisolate-erroneous-paths-attribute
3119 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
3120 Detect paths that trigger erroneous or undefined behavior due to a null value
3121 being used in a way forbidden by a returns_nonnull or nonnull
3122 attribute. Isolate those paths from the main control flow and turn the
3123 statement with erroneous or undefined behavior into a trap.
3125 ftree-loop-distribution
3126 Common Var(flag_tree_loop_distribution) Optimization
3127 Enable loop distribution on trees.
3129 ftree-loop-distribute-patterns
3130 Common Var(flag_tree_loop_distribute_patterns) Optimization
3131 Enable loop distribution for patterns transformed into a library call.
3134 Common Var(flag_tree_loop_im) Init(1) Optimization
3135 Enable loop invariant motion on trees.
3138 Common Alias(floop-nest-optimize)
3139 Enable loop nest transforms. Same as -floop-nest-optimize.
3142 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
3143 Create canonical induction variables in loops.
3146 Common Var(flag_tree_loop_optimize) Init(1) Optimization
3147 Enable loop optimizations on tree level.
3149 ftree-parallelize-loops=
3150 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
3151 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
3154 Common Var(flag_tree_phiprop) Init(1) Optimization
3155 Enable hoisting loads from conditional pointers.
3158 Common Var(flag_tree_pre) Optimization
3159 Enable SSA-PRE optimization on trees.
3162 Common Var(flag_tree_partial_pre) Optimization
3163 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
3166 Common Var(flag_tree_pta) Optimization
3167 Perform function-local points-to analysis on trees.
3170 Common Var(flag_tree_reassoc) Init(1) Optimization
3171 Enable reassociation on tree level.
3175 Does nothing. Preserved for backward compatibility.
3178 Common Var(flag_tree_sink) Optimization
3179 Enable SSA code sinking on trees.
3182 Common Var(flag_tree_slsr) Optimization
3183 Perform straight-line strength reduction.
3186 Common Var(flag_tree_sra) Optimization
3187 Perform scalar replacement of aggregates.
3190 Common Var(flag_tree_ter) Optimization
3191 Replace temporary expressions in the SSA->normal pass.
3194 Common Var(flag_tree_live_range_split) Optimization
3195 Perform live range splitting during the SSA->normal pass.
3198 Common Var(flag_tree_vrp) Init(0) Optimization
3199 Perform Value Range Propagation on trees.
3202 Common Var(flag_split_paths) Init(0) Optimization
3203 Split paths leading to loop backedges.
3205 funconstrained-commons
3206 Common Var(flag_unconstrained_commons) Optimization
3207 Assume common declarations may be overridden with ones with a larger
3211 Common Var(flag_unit_at_a_time) Init(1)
3212 Compile whole compilation unit at a time.
3215 Common Var(flag_unreachable_traps) Optimization
3216 Trap on __builtin_unreachable instead of using it for optimization.
3219 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3220 Perform loop unrolling when iteration count is known.
3223 Common Var(flag_unroll_all_loops) Optimization
3224 Perform loop unrolling for all loops.
3226 funroll-completely-grow-size
3227 Undocumented Var(flag_cunroll_grow_size) Optimization
3228 ; Internal undocumented flag, allow size growth during complete unrolling
3230 ; Nonzero means that loop optimizer may assume that the induction variables
3231 ; that control loops do not overflow and that the loops with nontrivial
3232 ; exit condition are not infinite
3233 funsafe-loop-optimizations
3235 Does nothing. Preserved for backward compatibility.
3238 Common Var(flag_associative_math) SetByCombined Optimization
3239 Allow optimization for floating-point arithmetic which may change the
3240 result of the operation due to rounding.
3243 Common Var(flag_reciprocal_math) SetByCombined Optimization
3244 Same as -fassociative-math for expressions which include division.
3246 ; Nonzero means that unsafe floating-point math optimizations are allowed
3247 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
3248 ; are allowed to assume that their arguments and results are "normal"
3249 ; (e.g., nonnegative for SQRT).
3250 funsafe-math-optimizations
3251 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3252 Allow math optimizations that may violate IEEE or ISO standards.
3255 Common Var(flag_unswitch_loops) Optimization
3256 Perform loop unswitching.
3259 Common Var(flag_split_loops) Optimization
3260 Perform loop splitting.
3262 fversion-loops-for-strides
3263 Common Var(flag_version_loops_for_strides) Optimization
3264 Version loops based on whether indices have a stride of one.
3267 Common Var(flag_unwind_tables) Optimization
3268 Just generate unwind tables for exception handling.
3271 Common Driver Negative(fuse-ld=gold)
3272 Use the bfd linker instead of the default linker.
3275 Common Driver Negative(fuse-ld=bfd)
3276 Use the gold linker instead of the default linker.
3279 Common Driver Negative(fuse-ld=lld)
3280 Use the lld LLVM linker instead of the default linker.
3283 Common Driver Negative(fuse-ld=mold)
3284 Use the Modern linker (MOLD) linker instead of the default linker.
3287 Common Undocumented Var(flag_use_linker_plugin)
3289 ; Positive if we should track variables, negative if we should run
3290 ; the var-tracking pass only to discard debug annotations, zero if
3291 ; we're not to run it.
3293 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3294 Perform variable tracking.
3296 ; Positive if we should track variables at assignments, negative if
3297 ; we should run the var-tracking pass only to discard debug
3299 fvar-tracking-assignments
3300 Common Var(flag_var_tracking_assignments) PerFunction
3301 Perform variable tracking by annotating assignments.
3303 ; Nonzero if we should toggle flag_var_tracking_assignments after
3304 ; processing options and computing its default. */
3305 fvar-tracking-assignments-toggle
3306 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3307 Toggle -fvar-tracking-assignments.
3309 ; Positive if we should track uninitialized variables, negative if
3310 ; we should run the var-tracking pass only to discard debug
3312 fvar-tracking-uninit
3313 Common Var(flag_var_tracking_uninit) PerFunction
3314 Perform variable tracking and also tag variables that are uninitialized.
3316 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3318 Common Var(flag_tree_vectorize) Optimization
3319 Enable vectorization on trees.
3321 ftree-vectorizer-verbose=
3322 Common Joined RejectNegative Ignore
3323 Does nothing. Preserved for backward compatibility.
3325 ftree-loop-vectorize
3326 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3327 Enable loop vectorization on trees.
3330 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3331 Enable basic block vectorization (SLP) on trees.
3334 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3335 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the cost model for vectorization.
3338 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3339 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the vectorization cost model for code marked with a simd directive.
3342 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3345 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3348 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3351 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3354 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3357 Common Alias(fvect-cost-model=,dynamic,unlimited)
3358 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
3360 ftree-vect-loop-version
3362 Does nothing. Preserved for backward compatibility.
3365 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3366 Enable copy propagation of scalar-evolution information.
3368 ftrivial-auto-var-init=
3369 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3370 -ftrivial-auto-var-init=[uninitialized|pattern|zero] Add initializations to automatic variables.
3373 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3376 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3379 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3382 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3384 ; -fverbose-asm causes extra commentary information to be produced in
3385 ; the generated assembly code (to make it more readable). This option
3386 ; is generally only of use to those who actually need to read the
3387 ; generated assembly code (perhaps while debugging the compiler itself).
3388 ; -fno-verbose-asm, the default, causes the extra information
3389 ; to not be added and is useful when comparing two assembler files.
3391 Common Var(flag_verbose_asm)
3392 Add extra commentary to assembler output.
3395 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3396 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
3399 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3402 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3405 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3408 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3411 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3414 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3415 Validate vtable pointers before using them.
3418 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3421 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3424 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3427 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3430 Common Var(flag_vtv_counts)
3431 Output vtable verification counters.
3434 Common Var(flag_vtv_debug)
3435 Output vtable verification pointer sets information.
3438 Common Var(flag_value_profile_transformations) Optimization
3439 Use expression value profiles in optimizations.
3442 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3443 Construct webs and split unrelated uses of single variable.
3445 ftree-builtin-call-dce
3446 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3447 Enable conditional dead code elimination for builtin calls.
3450 Common Var(flag_whole_program) Init(0)
3451 Perform whole program optimizations.
3454 Common Var(flag_wrapv_pointer) Optimization
3455 Assume pointer overflow wraps around.
3458 Common Var(flag_wrapv) Optimization
3459 Assume signed arithmetic overflow wraps around.
3461 fzero-initialized-in-bss
3462 Common Var(flag_zero_initialized_in_bss) Init(1)
3463 Put zero initialized data in the bss section.
3465 fzero-call-used-regs=
3466 Common RejectNegative Joined
3467 Clear call-used registers upon function return.
3470 Common Driver RejectNegative JoinedOrMissing
3471 Generate debug information in default format.
3474 Common Driver Var(dwarf2out_as_loc_support)
3475 Assume assembler support for (DWARF2+) .loc directives.
3478 Common Driver Var(dwarf2out_as_locview_support)
3479 Assume assembler support for view in (DWARF2+) .loc directives.
3482 Common Driver JoinedOrMissing
3483 Generate debug information in CodeView format.
3486 Common Driver WarnRemoved
3487 Does nothing. Preserved for backward compatibility.
3490 Common Driver WarnRemoved
3491 Does nothing. Preserved for backward compatibility.
3494 Common Driver WarnRemoved
3495 Does nothing. Preserved for backward compatibility.
3498 Common Driver WarnRemoved
3499 Does nothing. Preserved for backward compatibility.
3502 Common Driver Var(debug_column_info,1) Init(1)
3503 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3505 ; The CTF generation process feeds off DWARF dies. This option implicitly
3506 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3508 Common Driver RejectNegative JoinedOrMissing
3509 Generate CTF debug information at default level.
3512 Common Driver RejectNegative JoinedOrMissing
3513 Generate BTF debug information at default level.
3516 Common Driver JoinedOrMissing RejectNegative
3517 Generate debug information in default version of DWARF format.
3520 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT) RejectNegative
3521 Generate debug information in DWARF v2 (or later) format.
3524 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3525 Use 32-bit DWARF format when emitting DWARF debug information.
3528 Common Driver Var(dwarf_offset_size,8) RejectNegative
3529 Use 64-bit DWARF format when emitting DWARF debug information.
3532 Common Driver JoinedOrMissing RejectNegative
3533 Generate debug information in default extended format.
3536 Common Driver Var(debug_inline_points)
3537 Generate extended entry point information for inlined functions.
3539 ginternal-reset-location-views
3540 Common Driver Var(debug_internal_reset_location_views) Init(2)
3541 Compute locview reset points based on insn length estimates.
3544 RejectNegative Joined Undocumented
3545 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3548 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3549 Don't generate DWARF pubnames and pubtypes sections.
3552 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3553 Generate DWARF pubnames and pubtypes sections.
3556 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3557 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3559 grecord-gcc-switches
3560 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3561 Record gcc command line switches in DWARF DW_AT_producer.
3564 Common Driver Var(dwarf_split_debug_info) Init(0)
3565 Generate debug information in separate .dwo files.
3568 Common Driver WarnRemoved
3569 Does nothing. Preserved for backward compatibility.
3572 Common Driver WarnRemoved
3573 Does nothing. Preserved for backward compatibility.
3575 gstatement-frontiers
3576 Common Driver Var(debug_nonbind_markers_p) PerFunction
3577 Emit progressive recommended breakpoint locations.
3580 Common Driver Var(dwarf_strict) Init(0)
3581 Don't emit DWARF additions beyond selected version.
3584 Common Driver Var(flag_describe_dies) Init(0)
3585 Add description attributes to some DWARF DIEs that have no name attribute.
3588 Common Driver Var(flag_gtoggle)
3589 Toggle debug information generation.
3591 gvariable-location-views
3592 Common Driver Var(debug_variable_location_views, 1)
3593 Augment variable location lists with progressive views.
3595 gvariable-location-views=incompat5
3596 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3599 Common Driver JoinedOrMissing RejectNegative
3600 Generate debug information in VMS format.
3603 Common Driver WarnRemoved
3604 Does nothing. Preserved for backward compatibility.
3607 Common Driver JoinedOrMissing WarnRemoved
3608 Does nothing. Preserved for backward compatibility.
3611 Name(compressed_debug_sections) Type(int)
3613 ; Since -gz= is completely handled in specs, the values aren't used and we
3614 ; assign arbitrary constants.
3616 Enum(compressed_debug_sections) String(none) Value(0)
3619 Enum(compressed_debug_sections) String(zlib) Value(1)
3622 Enum(compressed_debug_sections) String(zstd) Value(2)
3625 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3629 Generate compressed debug sections.
3632 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3633 -gz=<format> Generate compressed debug sections in format <format>.
3636 Driver Joined Separate
3639 Common Joined Var(plugindir_string) Init(0)
3640 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3643 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3644 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3647 Driver Joined Separate
3652 no-canonical-prefixes
3671 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3672 -o <file> Place output into <file>.
3675 Common Var(profile_flag)
3676 Enable function profiling.
3679 Driver Var(pass_exit_codes)
3682 Common Alias(Wpedantic)
3685 Common Var(flag_pedantic_errors)
3686 Like -pedantic but issue them as errors.
3692 Driver Var(use_pipes)
3695 Driver JoinedOrMissing Var(print_file_name)
3697 print-libgcc-file-name
3700 print-multi-directory
3701 Driver Var(print_multi_directory)
3704 Driver Var(print_multi_lib)
3706 print-multi-os-directory
3707 Driver Var(print_multi_os_directory)
3710 Driver Var(print_multiarch)
3713 Driver JoinedOrMissing Var(print_prog_name)
3716 Driver Var(print_search_dirs)
3719 Driver Var(print_sysroot)
3721 print-sysroot-headers-suffix
3722 Driver Var(print_sysroot_headers_suffix)
3725 Common Var(quiet_flag) RejectDriver
3726 Do not display functions compiled or elapsed time.
3744 Driver Var(report_times)
3747 Driver JoinedOrMissing
3750 Driver Joined Separate
3754 ; C option, but driver must not handle as "-u ndef".
3757 Common Driver Var(verbose_flag)
3758 Enable verbose output.
3761 Common Var(version_flag) RejectDriver
3762 Display the compiler's version.
3765 Common Var(inhibit_warnings)
3769 Driver Separate Var(wrapper_string)
3772 Driver Joined Separate
3775 Driver RejectNegative Negative(static-pie)
3776 Create a shared library.
3782 Driver Separate Alias(specs=)
3795 ; Documented for Fortran, but always accepted by driver.
3799 ; Documented for Modula-2, but always accepted by driver.
3803 ; Documented for D, but always accepted by driver.
3807 ; Documented for Fortran, but always accepted by driver.
3814 ; Documented for Go, but always accepted by driver.
3835 Driver RejectNegative Negative(shared)
3836 Don't create a dynamically linked position independent executable.
3839 Driver RejectNegative Negative(no-pie)
3840 Create a dynamically linked position independent executable.
3843 Driver RejectNegative Negative(pie)
3844 Create a static position independent executable.
3847 Driver Joined Separate
3850 Common Var(flag_ipa_ra) Optimization
3851 Use caller save register across calls if possible.
3853 ; This comment is to ensure we retain the blank line above.