1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2023 Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
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 ; Default in G++ 14.
1025 ; Additional positive integers will be assigned as new versions of
1026 ; the ABI become the default version of the ABI.
1028 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1029 The version of the C++ ABI in use.
1031 faggressive-loop-optimizations
1032 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1033 Aggressively optimize loops using language constraints.
1036 Common Var(flag_align_functions) Optimization
1037 Align the start of functions.
1040 Common RejectNegative Joined Var(str_align_functions) Optimization
1042 flimit-function-alignment
1043 Common Var(flag_limit_function_alignment) Optimization Init(0)
1046 Common Var(flag_align_jumps) Optimization
1047 Align labels which are only reached by jumping.
1050 Common RejectNegative Joined Var(str_align_jumps) Optimization
1053 Common Var(flag_align_labels) Optimization
1057 Common RejectNegative Joined Var(str_align_labels) Optimization
1060 Common Var(flag_align_loops) Optimization
1061 Align the start of loops.
1064 Common RejectNegative Joined Var(str_align_loops) Optimization
1066 fallow-store-data-races
1067 Common Var(flag_store_data_races) Optimization
1068 Allow the compiler to introduce new data races on stores.
1071 Common Var(flag_analyzer)
1072 Enable static analysis pass.
1076 Does nothing. Preserved for backward compatibility.
1080 Does nothing. Preserved for backward compatibility.
1082 fargument-noalias-global
1084 Does nothing. Preserved for backward compatibility.
1086 fargument-noalias-anything
1088 Does nothing. Preserved for backward compatibility.
1091 Common Driver Joined
1092 Select what to sanitize.
1095 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1096 Select type of coverage sanitization.
1099 Name(sanitize_coverage) Type(int)
1102 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1105 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1107 fasan-shadow-offset=
1108 Common Joined RejectNegative Var(common_deferred_options) Defer
1109 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1112 Common Joined RejectNegative Var(common_deferred_options) Defer
1113 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1114 in user-defined sections.
1118 After diagnosing undefined behavior attempt to continue execution.
1122 This switch is deprecated; use -fsanitize-recover= instead.
1125 Common Driver Joined
1126 Use traps instead of diagnostics of undefined behavior sanitizers.
1131 fsanitize-address-use-after-scope
1132 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1134 fsanitize-undefined-trap-on-error
1135 Common Driver Alias(fsanitize-trap)
1136 This switch is deprecated; use -fsanitize-trap= instead.
1138 fasynchronous-unwind-tables
1139 Common Var(flag_asynchronous_unwind_tables) Optimization
1140 Generate unwind tables that are exact at each instruction boundary.
1143 Common Var(flag_auto_inc_dec) Init(1) Optimization
1144 Generate auto-inc/dec instructions.
1147 Common Var(flag_auto_profile)
1148 Use sample profile information for call graph node weights. The default
1149 profile file is fbdata.afdo in 'pwd'.
1152 Common Joined RejectNegative Var(auto_profile_file)
1153 Use sample profile information for call graph node weights. The profile
1154 file is specified in the argument.
1156 ; -fcheck-bounds causes gcc to generate array bounds checks.
1157 ; For C, C++ and ObjC: defaults off.
1158 ; For Java: defaults to on.
1159 ; For Fortran: defaults to off.
1161 Common Var(flag_bounds_check)
1162 Generate code to check bounds before indexing arrays.
1165 Common Var(flag_branch_on_count_reg) Optimization
1166 Replace add, compare, branch with branch on count register.
1168 fbranch-probabilities
1169 Common Var(flag_branch_probabilities) Optimization
1170 Use profiling information for branch probabilities.
1172 fbranch-target-load-optimize
1174 Does nothing. Preserved for backward compatibility.
1176 fbranch-target-load-optimize2
1178 Does nothing. Preserved for backward compatibility.
1182 Does nothing. Preserved for backward compatibility.
1185 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1186 Output callgraph information on a per-file basis.
1189 Common RejectNegative Joined
1190 Output callgraph information on a per-file basis with decorations.
1193 Common Joined RejectNegative Var(common_deferred_options) Defer
1194 -fcall-saved-<register> Mark <register> as being preserved across functions.
1197 Common Joined RejectNegative Var(common_deferred_options) Defer
1198 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1200 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1201 ; be saved across function calls, if that produces overall better code.
1202 ; Optional now, so people can test it.
1204 Common Var(flag_caller_saves) Optimization
1205 Save registers around function calls.
1209 This switch is deprecated; do not use.
1212 Common Var(flag_check_new)
1213 Check the return value of new in C++.
1216 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1217 Perform internal consistency checkings.
1220 Common Joined RejectNegative UInteger Var(flag_checking)
1221 Perform internal consistency checkings.
1224 Common Var(common_deferred_options) Defer
1225 For -f*-prefix-map= options compare canonicalized pathnames rather than just strings.
1228 Common Var(flag_code_hoisting) Optimization
1229 Enable code hoisting.
1231 fcombine-stack-adjustments
1232 Common Var(flag_combine_stack_adjustments) Optimization
1233 Looks for opportunities to reduce stack adjustments and stack references.
1236 Common Var(flag_no_common,0) Init(1)
1237 Put uninitialized globals in the common section.
1241 ; Converted by the driver to -fcompare-debug= options.
1244 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1245 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1247 fcompare-debug-second
1248 Common Driver RejectNegative Var(flag_compare_debug)
1249 Run only the second compilation of -fcompare-debug.
1252 Common Var(flag_compare_elim_after_reload) Optimization
1253 Perform comparison elimination after register allocation has finished.
1256 Common Var(flag_conserve_stack) Optimization
1257 Do not perform optimizations increasing noticeably stack usage.
1260 Common Var(flag_cprop_registers) Optimization
1261 Perform a register copy-propagation optimization pass.
1264 Target Bool Var(flag_fold_mem_offsets) Init(1)
1265 Fold instructions calculating memory offsets to the memory access instruction if possible.
1268 Common Var(flag_crossjumping) Optimization
1269 Perform cross-jumping optimization.
1272 Common Var(flag_cse_follow_jumps) Optimization
1273 When running CSE, follow jumps to their targets.
1277 Does nothing. Preserved for backward compatibility.
1280 Common Var(flag_cx_limited_range) Optimization SetByCombined
1281 Omit range reduction step when performing complex division.
1284 Common Var(flag_cx_fortran_rules) Optimization
1285 Complex multiplication and division follow Fortran rules.
1288 Common Var(flag_data_sections)
1289 Place data items into their own section.
1292 Common Var(flag_dbg_cnt_list)
1293 List all available debugging counters with their limits and counts.
1296 Common RejectNegative Joined Var(common_deferred_options) Defer
1297 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1300 Common Joined RejectNegative Var(common_deferred_options) Defer
1301 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1304 Common Joined RejectNegative Var(common_deferred_options) Defer
1305 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1307 fdebug-types-section
1308 Common Var(flag_debug_types_section) Init(0)
1309 Output .debug_types section when using DWARF v4 debuginfo.
1311 ; Nonzero for -fdefer-pop: don't pop args after each function call
1312 ; instead save them up to pop many calls' args with one insns.
1314 Common Var(flag_defer_pop) Optimization
1315 Defer popping functions args from stack until later.
1318 Common Var(flag_delayed_branch) Optimization
1319 Attempt to fill delay slots of branch instructions.
1321 fdelete-dead-exceptions
1322 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1323 Delete dead instructions that may throw exceptions.
1325 fdelete-null-pointer-checks
1326 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1327 Delete useless null pointer checks.
1329 fdevirtualize-at-ltrans
1330 Common Var(flag_ltrans_devirtualize)
1331 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1333 fdevirtualize-speculatively
1334 Common Var(flag_devirtualize_speculatively) Optimization
1335 Perform speculative devirtualization.
1338 Common Var(flag_devirtualize) Optimization
1339 Try to convert virtual calls to direct ones.
1341 fdiagnostics-show-location=
1342 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1343 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1345 ; Required for these enum values.
1350 Name(diagnostic_prefixing_rule) Type(int)
1353 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1356 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1358 fdiagnostics-show-caret
1359 Common Var(flag_diagnostics_show_caret) Init(1)
1360 Show the source line with a caret indicating the column.
1362 fdiagnostics-show-labels
1363 Common Var(flag_diagnostics_show_labels) Init(1)
1364 Show labels annotating ranges of source code when showing source.
1366 fdiagnostics-show-line-numbers
1367 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1368 Show line numbers in the left margin when showing source.
1371 Common Alias(fdiagnostics-color=,always,never)
1375 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1376 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1378 ; Required for these enum values.
1383 Name(diagnostic_color_rule) Type(int)
1386 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1389 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1392 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1395 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1396 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1398 ; Required for these enum values.
1403 Name(diagnostic_url_rule) Type(int)
1406 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1409 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1412 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1414 fdiagnostics-column-unit=
1415 Common Joined RejectNegative Enum(diagnostics_column_unit)
1416 -fdiagnostics-column-unit=[display|byte] Select whether column numbers are output as display columns (default) or raw bytes.
1418 fdiagnostics-column-origin=
1419 Common Joined RejectNegative UInteger
1420 -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.
1422 fdiagnostics-format=
1423 Common Joined RejectNegative Enum(diagnostics_output_format)
1424 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file] Select output format.
1426 fdiagnostics-escape-format=
1427 Common Joined RejectNegative Enum(diagnostics_escape_format)
1428 -fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1430 ; Required for these enum values.
1435 Name(diagnostics_column_unit) Type(int)
1438 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1441 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1444 Name(diagnostics_escape_format) Type(int)
1447 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1450 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1453 Name(diagnostics_output_format) Type(int)
1456 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1459 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1462 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1465 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1468 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1471 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1473 fdiagnostics-parseable-fixits
1474 Common Var(flag_diagnostics_parseable_fixits)
1475 Print fix-it hints in machine-readable form.
1477 fdiagnostics-generate-patch
1478 Common Var(flag_diagnostics_generate_patch)
1479 Print fix-it hints to stderr in unified diff format.
1481 fdiagnostics-show-option
1482 Common Var(flag_diagnostics_show_option) Init(1)
1483 Amend appropriate diagnostic messages with the command line option that controls them.
1485 fdiagnostics-show-cwe
1486 Common Var(flag_diagnostics_show_cwe) Init(1)
1487 Print CWE identifiers for diagnostic messages, where available.
1489 fdiagnostics-show-rules
1490 Common Var(flag_diagnostics_show_rules) Init(1)
1491 Print any rules associated with diagnostic messages.
1493 fdiagnostics-path-format=
1494 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1495 Specify how to print any control-flow path associated with a diagnostic.
1497 fdiagnostics-plain-output
1498 Driver Common RejectNegative
1499 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1502 Common Joined RejectNegative UInteger
1503 -ftabstop=<number> Distance between tab stops for column reporting.
1506 Name(diagnostic_path_format) Type(int)
1509 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1512 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1515 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1517 fdiagnostics-show-path-depths
1518 Common Var(flag_diagnostics_show_path_depths) Init(0)
1519 Show stack depths of events in paths.
1521 fdiagnostics-text-art-charset=
1522 Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1523 -fdiagnostics-text-art-charset=[none|ascii|unicode|emoji] Determine which characters to use in text arg diagrams.
1526 Name(diagnostic_text_art_charset) Type(int)
1529 Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
1532 Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
1535 Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
1538 Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1540 fdiagnostics-minimum-margin-width=
1541 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1542 Set minimum width of left margin of source code when showing source.
1545 Common Joined RejectNegative Var(common_deferred_options) Defer
1546 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 Disable an optimization pass.
1549 Common Joined RejectNegative Var(common_deferred_options) Defer
1550 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 Enable an optimization pass.
1553 Common Joined RejectNegative Var(common_deferred_options) Defer
1554 -fdump-<type> Dump various compiler internals to a file.
1557 Driver RejectNegative
1560 Common RejectNegative Joined Var(flag_dump_final_insns)
1561 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1564 Common RejectNegative Joined Var(flag_dump_go_spec)
1565 -fdump-go-spec=filename Write all declarations to file as Go code.
1568 Common Var(flag_dump_noaddr)
1569 Suppress output of addresses in debugging dumps.
1572 Common Driver Var(flag_report_bug)
1573 Collect and dump debug information into temporary file if ICE in C/C++
1576 fdump-internal-locations
1577 Common Var(flag_dump_locations) Init(0)
1578 Dump detailed information on GCC's internal representation of source code locations.
1581 Common Var(flag_dump_passes) Init(0)
1582 Dump optimization passes.
1585 Common Var(flag_dump_unnumbered)
1586 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1588 fdump-unnumbered-links
1589 Common Var(flag_dump_unnumbered_links)
1590 Suppress output of previous and next insn numbers in debugging dumps.
1593 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1594 Enable CFI tables via GAS assembler directives.
1597 Common Var(flag_early_inlining) Init(1) Optimization
1598 Perform early inlining.
1600 feliminate-dwarf2-dups
1602 Does nothing. Preserved for backward compatibility.
1605 Common Var(flag_ipa_sra) Init(0) Optimization
1606 Perform interprocedural reduction of aggregates.
1608 feliminate-unused-debug-symbols
1609 Common Var(flag_debug_only_used_symbols) Init(1)
1610 Perform unused symbol elimination in debug info.
1612 feliminate-unused-debug-types
1613 Common Var(flag_eliminate_unused_debug_types) Init(1)
1614 Perform unused type elimination in debug info.
1616 femit-class-debug-always
1617 Common Var(flag_emit_class_debug_always) Init(0)
1618 Do not suppress C++ class debug information.
1621 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1622 Enable exception handling.
1624 fexpensive-optimizations
1625 Common Var(flag_expensive_optimizations) Optimization
1626 Perform a number of minor, expensive optimizations.
1629 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1630 -fexcess-precision=[fast|standard|16] Specify handling of excess floating-point precision.
1633 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1636 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1639 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1642 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1644 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1645 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1646 fpermitted-flt-eval-methods=
1647 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1648 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1651 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)
1654 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1657 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1663 Common Var(flag_fat_lto_objects)
1664 Output lto objects containing both the intermediate language and binary output.
1667 Common Var(flag_finite_math_only) Optimization SetByCombined
1668 Assume no NaNs or infinities are generated.
1671 Common Var(flag_finite_loops) Optimization Init(0)
1672 Assume that loops with an exit will terminate and not loop indefinitely.
1675 Common Joined RejectNegative Var(common_deferred_options) Defer
1676 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1679 Common Var(flag_float_store) Optimization
1680 Don't allocate floats and doubles in extended-precision registers.
1684 Does nothing. Preserved for backward compatibility.
1687 Common Var(flag_forward_propagate) Optimization
1688 Perform a forward propagation pass on RTL.
1691 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1692 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1695 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1698 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1701 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_ON)
1704 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1706 ffp-int-builtin-inexact
1707 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1708 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1710 ; Nonzero means don't put addresses of constant functions in registers.
1711 ; Used for compiling the Unix kernel, where strange substitutions are
1712 ; done on the assembly output.
1714 Common Var(flag_no_function_cse,0) Optimization
1715 Allow function addresses to be held in registers.
1718 Common Var(flag_function_sections)
1719 Place each function into its own section.
1722 Common Var(flag_gcse) Optimization
1723 Perform global common subexpression elimination.
1726 Common Var(flag_gcse_lm) Init(1) Optimization
1727 Perform enhanced load motion during global common subexpression elimination.
1730 Common Var(flag_gcse_sm) Init(0) Optimization
1731 Perform store motion after global common subexpression elimination.
1734 Common Var(flag_gcse_las) Init(0) Optimization
1735 Perform redundant load after store elimination in global common subexpression
1739 Common Var(flag_gcse_after_reload) Optimization
1740 Perform global common subexpression elimination after register allocation has
1744 Name(dwarf_gnat_encodings) Type(int)
1747 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1750 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1753 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1756 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1757 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1759 ; This option is not documented yet as its semantics will change.
1761 Common Var(flag_graphite) Optimization
1762 Enable in and out of Graphite representation.
1765 Common Var(flag_graphite_identity) Optimization
1766 Enable Graphite Identity transformation.
1768 fhoist-adjacent-loads
1769 Common Var(flag_hoist_adjacent_loads) Optimization
1770 Enable hoisting adjacent loads to encourage generating conditional move
1774 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1775 ; Always keep a pointer to a live memory block
1778 Common Var(flag_large_source_files) Init(0)
1779 Improve GCC's ability to track column numbers in large source files,
1780 at the expense of slower compilation.
1782 floop-parallelize-all
1783 Common Var(flag_loop_parallelize_all) Optimization
1784 Mark all loops as parallel.
1787 Common Alias(floop-nest-optimize)
1788 Enable loop nest transforms. Same as -floop-nest-optimize.
1791 Common Var(flag_loop_interchange) Optimization
1792 Enable loop interchange on trees.
1795 Common Alias(floop-nest-optimize)
1796 Enable loop nest transforms. Same as -floop-nest-optimize.
1798 floop-unroll-and-jam
1799 Common Var(flag_unroll_jam) Optimization
1800 Perform unroll-and-jam on loops.
1804 Enable support for GNU transactional memory.
1807 Common Var(flag_gnu_unique) Init(1)
1808 Use STB_GNU_UNIQUE if supported by the assembler.
1812 Does nothing. Preserved for backward compatibility.
1815 Common Var(flag_loop_nest_optimize) Optimization
1816 Enable the loop nest optimizer.
1818 fstrict-volatile-bitfields
1819 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1820 Force bitfield accesses to match their type width.
1823 Common Var(flag_store_merging) Optimization
1824 Merge adjacent stores.
1826 fguess-branch-probability
1827 Common Var(flag_guess_branch_prob) Optimization
1828 Enable guessing of branch probabilities.
1831 Common Driver Var(flag_hardened)
1832 Enable various security-relevant flags.
1835 Common Var(flag_harden_compares) Optimization
1836 Harden conditionals not used in branches, checking reversed conditions.
1838 fharden-conditional-branches
1839 Common Var(flag_harden_conditional_branches) Optimization
1840 Harden conditional branches by checking reversed conditions.
1842 fharden-control-flow-redundancy
1843 Common Var(flag_harden_control_flow_redundancy) Optimization
1844 Harden control flow by recording and checking execution paths.
1847 Common Var(flag_harden_control_flow_redundancy_skip_leaf) Optimization
1848 Disable CFR in leaf functions.
1850 fhardcfr-check-returning-calls
1851 Common Var(flag_harden_control_flow_redundancy_check_returning_calls) Init(-1) Optimization
1852 Check CFR execution paths also before calls followed by returns of their results.
1854 fhardcfr-check-exceptions
1855 Common Var(flag_harden_control_flow_redundancy_check_exceptions) Init(-1) Optimization
1856 Check CFR execution paths also when exiting a function through an exception.
1858 fhardcfr-check-noreturn-calls=
1859 Common Joined RejectNegative Enum(hardcfr_check_noreturn_calls) Var(flag_harden_control_flow_redundancy_check_noreturn) Init(HCFRNR_UNSPECIFIED) Optimization
1860 -fhardcfr-check-noreturn-calls=[always|no-xthrow|nothrow|never] Check CFR execution paths also before calling noreturn functions.
1863 Name(hardcfr_check_noreturn_calls) Type(enum hardcfr_noret) UnknownError(unknown hardcfr noreturn checking level %qs)
1866 Enum(hardcfr_check_noreturn_calls) String(never) Value(HCFRNR_NEVER)
1869 Enum(hardcfr_check_noreturn_calls) String(nothrow) Value(HCFRNR_NOTHROW)
1872 Enum(hardcfr_check_noreturn_calls) String(no-xthrow) Value(HCFRNR_NO_XTHROW)
1875 Enum(hardcfr_check_noreturn_calls) String(always) Value(HCFRNR_ALWAYS)
1877 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1878 ; Generate position-independent code for executables if possible
1879 ; On SVR4 targets, it also controls whether or not to emit a
1880 ; string identifying the compiler.
1882 Common Var(flag_no_ident,0)
1883 Process #ident directives.
1886 Common Var(flag_if_conversion) Optimization
1887 Perform conversion of conditional jumps to branchless equivalents.
1890 Common Var(flag_if_conversion2) Optimization
1891 Perform conversion of conditional jumps to conditional execution.
1894 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1895 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1898 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1901 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1904 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1907 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1909 ftree-loop-if-convert
1910 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1911 Convert conditional jumps in innermost loops to branchless equivalents.
1913 ftree-loop-if-convert-stores
1915 Does nothing. Preserved for backward compatibility.
1917 ; -finhibit-size-directive inhibits output of .size for ELF.
1918 ; This is used only for compiling crtstuff.c,
1919 ; and it may be extended to other effects
1920 ; needed for crtstuff.c on other systems.
1921 finhibit-size-directive
1922 Common Var(flag_inhibit_size_directive)
1923 Do not generate .size directives.
1926 Common Var(flag_indirect_inlining) Optimization
1927 Perform indirect inlining.
1929 ; General flag to enable inlining. Specifying -fno-inline will disable
1930 ; all inlining apart from always-inline functions.
1932 Common Var(flag_no_inline,0) Init(0) Optimization
1933 Enable inlining of function declared \"inline\", disabling disables all inlining.
1935 finline-small-functions
1936 Common Var(flag_inline_small_functions) Optimization
1937 Integrate functions into their callers when code size is known not to grow.
1940 Common Var(flag_inline_functions) Optimization
1941 Integrate functions not declared \"inline\" into their callers when profitable.
1943 finline-functions-called-once
1944 Common Var(flag_inline_functions_called_once) Optimization
1945 Integrate functions only required by their single caller.
1948 Common RejectNegative Joined Alias(finline-limit=)
1951 Common RejectNegative Joined UInteger
1952 -finline-limit=<number> Limit the size of inlined functions to <number>.
1955 Common Var(flag_inline_atomics) Init(1) Optimization
1956 Inline __atomic operations when a lock free instruction sequence is available.
1959 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_ALL) Enum(ilsop_fn) Init(ILSOP_NONE) Optimization Undocumented
1961 fno-inline-stringops
1962 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_NONE) Enum(ilsop_fn) Optimization Undocumented
1965 Common Joined Var(flag_inline_stringops) EnumSet Enum(ilsop_fn) Optimization
1966 -finline-stringops[=memcmp|memcpy|memmove|memset]
1967 Expand supported mem/str operations inline, even if against optimization.
1970 Name(ilsop_fn) Type(enum ilsop_fn) UnknownError(unavailable stringop for inlining %qs)
1972 ; This is not part of any set.
1974 ; Enum(ilsop_fn) String(none) Value(ILSOP_NONE)
1977 Enum(ilsop_fn) String(memcmp) Value(ILSOP_MEMCMP) Set(1)
1980 Enum(ilsop_fn) String(memcpy) Value(ILSOP_MEMCPY) Set(2)
1983 Enum(ilsop_fn) String(memmove) Value(ILSOP_MEMMOVE) Set(3)
1986 Enum(ilsop_fn) String(memset) Value(ILSOP_MEMSET) Set(4)
1988 ; This is not part of any set either.
1990 ; Enum(ilsop_fn) String(all) Value(ILSOP_ALL)
1993 Common RejectNegative Alias(fcf-protection=,full)
1996 Common Joined RejectNegative Enum(cf_protection_level) EnumSet Var(flag_cf_protection) Init(CF_NONE)
1997 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
1998 instructions have valid targets.
2001 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
2004 Enum(cf_protection_level) String(full) Value(CF_FULL) Set(1)
2007 Enum(cf_protection_level) String(branch) Value(CF_BRANCH) Set(2)
2010 Enum(cf_protection_level) String(return) Value(CF_RETURN) Set(3)
2013 Enum(cf_protection_level) String(check) Value(CF_CHECK) Set(4)
2016 Enum(cf_protection_level) String(none) Value(CF_NONE) Set(1)
2018 finstrument-functions
2019 Common Var(flag_instrument_function_entry_exit,1)
2020 Instrument function entry and exit with profiling calls.
2022 finstrument-functions-once
2023 Common Var(flag_instrument_function_entry_exit,2)
2024 Instrument function entry and exit with profiling calls invoked once.
2026 finstrument-functions-exclude-function-list=
2027 Common RejectNegative Joined
2028 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
2030 finstrument-functions-exclude-file-list=
2031 Common RejectNegative Joined
2032 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
2035 Common Var(flag_ipa_cp) Optimization
2036 Perform interprocedural constant propagation.
2039 Common Var(flag_ipa_cp_clone) Optimization
2040 Perform cloning to make Interprocedural constant propagation stronger.
2044 Does nothing. Preserved for backward compatibility.
2047 Common Var(flag_ipa_bit_cp) Optimization
2048 Perform interprocedural bitwise constant propagation.
2051 Common Var(flag_ipa_modref) Optimization
2052 Perform interprocedural modref analysis.
2055 Common Var(flag_ipa_profile) Init(0) Optimization
2056 Perform interprocedural profile propagation.
2059 Common Var(flag_ipa_pta) Init(0) Optimization
2060 Perform interprocedural points-to analysis.
2063 Common Var(flag_ipa_pure_const) Init(0) Optimization
2064 Discover pure and const functions.
2067 Common Var(flag_ipa_icf) Optimization
2068 Perform Identical Code Folding for functions and read-only variables.
2071 Common Var(flag_ipa_icf_functions) Optimization
2072 Perform Identical Code Folding for functions.
2075 Common Var(flag_ipa_icf_variables) Optimization
2076 Perform Identical Code Folding for variables.
2079 Common Var(flag_ipa_reference) Init(0) Optimization
2080 Discover read-only and non addressable static variables.
2082 fipa-reference-addressable
2083 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
2084 Discover read-only, write-only and non-addressable static variables.
2086 fipa-stack-alignment
2087 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
2088 Reduce stack alignment on call sites if possible.
2092 Does nothing. Preserved for backward compatibility.
2096 Does nothing. Preserved for backward compatibility.
2099 Common Var(flag_ipa_vrp) Optimization
2100 Perform IPA Value Range Propagation.
2103 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
2104 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
2106 fipa-strict-aliasing
2107 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
2108 Assume strict aliasing rules apply across (uninlined) function boundaries.
2111 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
2114 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2117 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2120 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2121 -fira-region=[one|all|mixed] Set regions for IRA.
2124 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2127 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2130 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2133 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2136 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2137 Use IRA based register pressure calculation
2138 in RTL hoist optimizations.
2141 Common Var(flag_ira_loop_pressure) Optimization
2142 Use IRA based register pressure calculation
2143 in RTL loop optimizations.
2145 fira-share-save-slots
2146 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2147 Share slots for saving different hard registers.
2149 fira-share-spill-slots
2150 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2151 Share stack slots for spilled pseudo-registers.
2154 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2155 -fira-verbose=<number> Control IRA's level of diagnostic messages.
2158 Common Var(flag_ivopts) Init(1) Optimization
2159 Optimize induction variables on trees.
2162 Common Var(flag_jump_tables) Init(1) Optimization
2163 Use jump tables for sufficiently large switch statements.
2166 Common Var(flag_bit_tests) Init(1) Optimization
2167 Use bit tests for sufficiently large switch statements.
2169 fkeep-inline-functions
2170 Common Var(flag_keep_inline_functions)
2171 Generate code for functions even if they are fully inlined.
2173 fkeep-static-functions
2174 Common Var(flag_keep_static_functions)
2175 Generate code for static functions even if they are never called.
2178 Common Var(flag_keep_static_consts) Init(1)
2179 Emit static const variables even if they are not used.
2182 Common Var(flag_leading_underscore) Init(-1)
2183 Give external symbols a leading underscore.
2187 Does nothing. Preserved for backward compatibility.
2190 Common Var(flag_lra_remat) Optimization
2191 Do CFG-sensitive rematerialization in LRA.
2195 Enable link-time optimization.
2198 Common RejectNegative Joined Var(flag_lto)
2199 Link-time optimization with number of parallel jobs or jobserver.
2202 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2205 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2208 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2211 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2214 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2217 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2220 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2221 Specify the algorithm to partition symbols and vars at linktime.
2223 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2224 flto-compression-level=
2225 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2226 Use zlib/zstd compression level <number> for IL.
2228 flto-odr-type-merging
2230 Does nothing. Preserved for backward compatibility.
2233 Common Var(flag_lto_report) Init(0)
2234 Report various link-time optimization statistics.
2237 Common Var(flag_lto_report_wpa) Init(0)
2238 Report various link-time optimization statistics for WPA only.
2241 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2242 Set errno after built-in math functions.
2245 Common Joined RejectNegative UInteger Var(flag_max_errors)
2246 -fmax-errors=<number> Maximum number of errors to report.
2249 Common Var(mem_report)
2250 Report on permanent memory allocation.
2253 Common Var(mem_report_wpa)
2254 Report on permanent memory allocation in WPA only.
2256 ; This will attempt to merge constant section constants, if 1 only
2257 ; string constants and constants from constant pool, if 2 also constant
2259 fmerge-all-constants
2260 Common Var(flag_merge_constants,2) Init(1)
2261 Attempt to merge identical constants and constant variables.
2264 Common Var(flag_merge_constants,1)
2265 Attempt to merge identical constants across compilation units.
2267 fmerge-debug-strings
2268 Common Var(flag_merge_debug_strings) Init(1)
2269 Attempt to merge identical debug strings across compilation units.
2272 Common RejectNegative Joined UInteger
2273 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
2276 Common Var(flag_modulo_sched) Optimization
2277 Perform SMS based modulo scheduling before the first scheduling pass.
2279 fmodulo-sched-allow-regmoves
2280 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2281 Perform SMS based modulo scheduling with register moves allowed.
2283 fmove-loop-invariants
2284 Common Var(flag_move_loop_invariants) Optimization
2285 Move loop invariant computations out of loops.
2288 Common Var(flag_move_loop_stores) Optimization
2289 Move stores out of loops.
2293 Building block for specs-based multilib-aware TFLAGS.
2296 Common Var(flag_dce) Init(1) Optimization
2297 Use the RTL dead code elimination pass.
2300 Common Var(flag_dse) Init(0) Optimization
2301 Use the RTL dead store elimination pass.
2303 freschedule-modulo-scheduled-loops
2304 Common Var(flag_resched_modulo_sched) Optimization
2305 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2307 fnon-call-exceptions
2308 Common Var(flag_non_call_exceptions) Optimization
2309 Support synchronous non-call exceptions.
2312 Driver Joined MissingArgError(targets missing after %qs)
2315 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2316 -foffload-options=<targets>=<options> Specify options for the offloading targets.
2319 Common Joined RejectNegative Enum(offload_abi)
2320 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2323 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2326 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2329 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2332 Common Var(flag_omit_frame_pointer) Optimization
2333 When possible do not generate stack frames.
2335 fopenmp-target-simd-clone
2336 Common Alias(fopenmp-target-simd-clone=,any,none)
2338 fopenmp-target-simd-clone=
2339 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2340 Generate SIMD clones for functions with the OpenMP declare target directive.
2343 Name(target_simd_clone_device) Type(int)
2346 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2349 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2352 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2355 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2358 Common Var(flag_opt_info) Optimization
2359 Enable all optimization info dumps on stderr.
2362 Common Joined RejectNegative Var(common_deferred_options) Defer
2363 -fopt-info[-<type>=filename] Dump compiler optimization details.
2365 fsave-optimization-record
2366 Common Var(flag_save_optimization_record) Optimization
2367 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2369 foptimize-register-move
2371 Does nothing. Preserved for backward compatibility.
2373 foptimize-sibling-calls
2374 Common Var(flag_optimize_sibling_calls) Optimization
2375 Optimize sibling and tail recursive calls.
2378 Common Var(flag_partial_inlining) Optimization
2379 Perform partial inlining.
2382 Common Var(pre_ipa_mem_report)
2383 Report on memory allocation before interprocedural optimization.
2385 fpost-ipa-mem-report
2386 Common Var(post_ipa_mem_report)
2387 Report on memory allocation before interprocedural optimization.
2390 Common Var(flag_pack_struct) Optimization
2391 Pack structure members together without holes.
2394 Common RejectNegative Joined UInteger Optimization
2395 -fpack-struct=<number> Set initial maximum structure member alignment.
2398 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2399 Return small aggregates in memory, not registers.
2402 Common Var(flag_peel_loops) Optimization
2403 Perform loop peeling.
2406 Common Var(flag_no_peephole,0) Optimization
2407 Enable machine specific peephole optimizations.
2410 Common Var(flag_peephole2) Optimization
2411 Enable an RTL peephole pass before sched2.
2414 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2415 Generate position-independent code if possible (large mode).
2418 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2419 Generate position-independent code for executables if possible (large mode).
2422 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2423 Generate position-independent code if possible (small mode).
2426 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2427 Generate position-independent code for executables if possible (small mode).
2430 Common Var(flag_plt) Init(1) Optimization
2431 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2434 Common Joined RejectNegative Var(common_deferred_options) Defer
2435 Specify a plugin to load.
2438 Common Joined RejectNegative Var(common_deferred_options) Defer
2439 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2441 fpredictive-commoning
2442 Common Var(flag_predictive_commoning) Optimization
2443 Run predictive commoning optimization.
2445 fprefetch-loop-arrays
2446 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2447 Generate prefetch instructions, if available, for arrays in loops.
2450 Common Var(profile_flag)
2451 Enable basic program profiling code.
2454 Common Var(profile_abs_path_flag)
2455 Generate absolute source path names for gcov.
2458 Common Var(profile_arc_flag)
2459 Insert arc-based program profiling code.
2462 Common Joined RejectNegative Var(profile_data_prefix)
2463 Set the top-level directory for storing the profile data.
2464 The default is 'pwd'.
2467 Common Joined RejectNegative Var(profile_note_location)
2468 Select the name for storing the profile note file.
2471 Common Var(flag_profile_correction)
2472 Enable correction of flow inconsistent profile data input.
2475 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2476 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2478 fprofile-filter-files=
2479 Common Joined RejectNegative Var(flag_profile_filter_files)
2480 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2482 fprofile-exclude-files=
2483 Common Joined RejectNegative Var(flag_profile_exclude_files)
2484 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2487 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2490 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2493 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2496 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2498 fprofile-reproducible=
2499 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2500 -fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate.
2503 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2506 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2509 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2512 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2514 fprofile-prefix-path=
2515 Common Joined RejectNegative Var(profile_prefix_path)
2516 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2518 fprofile-prefix-map=
2519 Common Joined RejectNegative Var(common_deferred_options) Defer
2520 -fprofile-prefix-map=<old>=<new> Map one directory name to another in GCOV coverage result.
2524 Enable common options for generating profile info for profile feedback directed optimizations.
2527 Common Joined RejectNegative
2528 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2530 fprofile-info-section
2531 Common RejectNegative
2532 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2534 fprofile-info-section=
2535 Common Joined RejectNegative Var(profile_info_section)
2536 Register the profile information in the specified section instead of using a constructor/destructor.
2538 fprofile-partial-training
2539 Common Var(flag_profile_partial_training) Optimization
2540 Do not assume that functions never executed during the train run are cold.
2543 Common Var(flag_profile_use)
2544 Enable common options for performing profile feedback directed optimizations.
2547 Common Joined RejectNegative
2548 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2551 Common Var(flag_profile_values)
2552 Insert code to profile values of expressions.
2555 Common Var(profile_report)
2556 Report on consistency of profile.
2558 fprofile-reorder-functions
2559 Common Var(flag_profile_reorder_functions) Optimization
2560 Enable function reordering that improves code placement.
2562 fpatchable-function-entry=
2563 Common Var(flag_patchable_function_entry) Joined Optimization
2564 Insert NOP instructions at each function entry.
2567 Common Var(common_deferred_options) Defer
2570 Common Joined RejectNegative Var(common_deferred_options) Defer
2571 -frandom-seed=<string> Make compile reproducible using <string>.
2573 ; This switch causes the command line that was used to create an
2574 ; object file to be recorded into the object file. The exact format
2575 ; of this recording is target and binary file format dependent.
2576 ; It is related to the -fverbose-asm switch, but that switch only
2577 ; records information in the assembler output file as comments, so
2578 ; they never reach the object file.
2579 frecord-gcc-switches
2580 Common Var(flag_record_gcc_switches)
2581 Record gcc command line switches in the object file.
2584 Common Var(flag_pcc_struct_return,0) Optimization
2585 Return small aggregates in registers.
2589 Does nothing. Preserved for backward compatibility.
2592 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2593 Tell DSE that the storage for a C++ object is dead when the constructor
2594 starts and when the destructor finishes.
2597 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2600 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2603 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2604 -flive-patching=[inline-only-static|inline-clone] Control IPA
2605 optimizations to provide a safe compilation for live-patching. At the same
2606 time, provides multiple-level control on the enabled IPA optimizations.
2609 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2612 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2615 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2618 Common Var(flag_allocation_dce) Init(1) Optimization
2619 Tell DCE to remove unused C++ allocations.
2621 flive-range-shrinkage
2622 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2623 Relief of register pressure through live range shrinkage.
2626 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2627 Perform a register renaming optimization pass.
2630 Common Var(flag_schedule_fusion) Init(2) Optimization
2631 Perform a target dependent instruction fusion optimization pass.
2634 Common Var(flag_reorder_blocks) Optimization
2635 Reorder basic blocks to improve code placement.
2637 freorder-blocks-algorithm=
2638 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2639 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2642 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2645 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2648 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2650 freorder-blocks-and-partition
2651 Common Var(flag_reorder_blocks_and_partition) Optimization
2652 Reorder basic blocks and partition into hot and cold sections.
2655 Common Var(flag_reorder_functions) Optimization
2656 Reorder functions to improve code placement.
2658 frerun-cse-after-loop
2659 Common Var(flag_rerun_cse_after_loop) Optimization
2660 Add a common subexpression elimination pass after loop optimizations.
2664 Does nothing. Preserved for backward compatibility.
2667 Common Var(flag_rounding_math) Optimization SetByCombined
2668 Disable optimizations that assume default FP rounding behavior.
2671 Common Var(flag_schedule_interblock) Init(1) Optimization
2672 Enable scheduling across basic blocks.
2675 Common Var(flag_sched_pressure) Init(0) Optimization
2676 Enable register pressure sensitive insn scheduling.
2679 Common Var(flag_schedule_speculative) Init(1) Optimization
2680 Allow speculative motion of non-loads.
2683 Common Var(flag_schedule_speculative_load) Optimization
2684 Allow speculative motion of some loads.
2686 fsched-spec-load-dangerous
2687 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2688 Allow speculative motion of more loads.
2691 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2692 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2694 fsched2-use-superblocks
2695 Common Var(flag_sched2_use_superblocks) Optimization
2696 If scheduling post reload, do superblock scheduling.
2700 Does nothing. Preserved for backward compatibility.
2703 Common Var(flag_schedule_insns) Optimization
2704 Reschedule instructions before register allocation.
2707 Common Var(flag_schedule_insns_after_reload) Optimization
2708 Reschedule instructions after register allocation.
2710 ; This flag should be on when a target implements non-trivial
2711 ; scheduling hooks, maybe saving some information for its own sake.
2712 ; On IA64, for example, this is used for correct bundling.
2713 fselective-scheduling
2714 Common Var(flag_selective_scheduling) Optimization
2715 Schedule instructions using selective scheduling algorithm.
2717 fselective-scheduling2
2718 Common Var(flag_selective_scheduling2) Optimization
2719 Run selective scheduling after reload.
2722 Common Undocumented Joined Var(flag_self_test)
2723 Run self-tests, using the given path to locate test files.
2725 fsel-sched-pipelining
2726 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2727 Perform software pipelining of inner loops during selective scheduling.
2729 fsel-sched-pipelining-outer-loops
2730 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2731 Perform software pipelining of outer loops during selective scheduling.
2733 fsel-sched-reschedule-pipelined
2734 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2735 Reschedule pipelined regions without pipelining.
2737 fsemantic-interposition
2738 Common Var(flag_semantic_interposition) Init(1) Optimization
2739 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2741 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2742 ; of stalled insns into the ready list.
2743 fsched-stalled-insns
2744 Common Var(flag_sched_stalled_insns) Optimization UInteger
2745 Allow premature scheduling of queued insns.
2747 fsched-stalled-insns=
2748 Common RejectNegative Joined UInteger Optimization
2749 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2751 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2752 ; be examined for a dependency on a stalled insn that is candidate for
2753 ; premature removal from the queue of stalled insns into the ready list (has
2754 ; an effect only if the flag 'sched_stalled_insns' is set).
2755 fsched-stalled-insns-dep
2756 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2757 Set dependence distance checking in premature scheduling of queued insns.
2759 fsched-stalled-insns-dep=
2760 Common RejectNegative Joined UInteger Optimization
2761 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2763 fsched-group-heuristic
2764 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2765 Enable the group heuristic in the scheduler.
2767 fsched-critical-path-heuristic
2768 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2769 Enable the critical path heuristic in the scheduler.
2771 fsched-spec-insn-heuristic
2772 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2773 Enable the speculative instruction heuristic in the scheduler.
2775 fsched-rank-heuristic
2776 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2777 Enable the rank heuristic in the scheduler.
2779 fsched-last-insn-heuristic
2780 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2781 Enable the last instruction heuristic in the scheduler.
2783 fsched-dep-count-heuristic
2784 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2785 Enable the dependent count heuristic in the scheduler.
2788 Common Var(flag_section_anchors) Optimization
2789 Access data in the same section from shared anchor points.
2793 Does nothing. Preserved for backward compatibility.
2797 Does nothing. Preserved for backward compatibility.
2800 Common Var(flag_ree) Init(0) Optimization
2801 Turn on Redundant Extensions Elimination pass.
2804 Common Var(flag_show_column) Init(1)
2805 Show column numbers in diagnostics, when available. Default on.
2808 Common Var(flag_shrink_wrap) Optimization
2809 Emit function prologues only before parts of the function that need it,
2810 rather than at the top of the function.
2812 fshrink-wrap-separate
2813 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2814 Shrink-wrap parts of the prologue and epilogue separately.
2817 Common Var(flag_signaling_nans) Optimization SetByCombined
2818 Disable optimizations observable by IEEE signaling NaNs.
2821 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2822 Disable floating point optimizations that ignore the IEEE signedness of zero.
2824 fsingle-precision-constant
2825 Common Var(flag_single_precision_constant) Optimization
2826 Convert floating point constants to single precision constants.
2828 fsplit-ivs-in-unroller
2829 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2830 Split lifetimes of induction variables when loops are unrolled.
2833 Common Var(flag_split_stack) Init(-1)
2834 Generate discontiguous stack frames.
2837 Common Var(flag_split_wide_types) Optimization
2838 Split wide types into independent registers.
2840 fsplit-wide-types-early
2841 Common Var(flag_split_wide_types_early) Optimization
2842 Split wide types into independent registers earlier.
2845 Common Var(flag_ssa_backprop) Init(1) Optimization
2846 Enable backward propagation of use properties at the SSA level.
2849 Common Var(flag_ssa_phiopt) Optimization
2850 Optimize conditional patterns using SSA PHI nodes.
2853 Common Var(flag_stdarg_opt) Init(1) Optimization
2854 Optimize amount of stdarg registers saved to stack at start of function.
2856 fvariable-expansion-in-unroller
2857 Common Var(flag_variable_expansion_in_unroller) Optimization
2858 Apply variable expansion when loops are unrolled.
2861 Common RejectNegative Joined Optimization
2862 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2865 Common Alias(fstack-check=, specific, no)
2866 Insert stack checking code into the program. Same as -fstack-check=specific.
2868 fstack-clash-protection
2869 Common Var(flag_stack_clash_protection) Optimization
2870 Insert code to probe each page of stack space as it is allocated to protect
2871 from stack-clash style attacks.
2874 Common Var(common_deferred_options) Defer
2876 fstack-limit-register=
2877 Common RejectNegative Joined Var(common_deferred_options) Defer
2878 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2880 fstack-limit-symbol=
2881 Common RejectNegative Joined Var(common_deferred_options) Defer
2882 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2885 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2886 Use propolice as a stack protection method.
2888 fstack-protector-all
2889 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2890 Use a stack protection method for every function.
2892 fstack-protector-strong
2893 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2894 Use a smart stack protection method for certain functions.
2896 fstack-protector-explicit
2897 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2898 Use stack protection method only for functions with the stack_protect attribute.
2901 Common RejectNegative Var(flag_stack_usage)
2902 Output stack usage information on a per-function basis.
2906 Does nothing. Preserved for backward compatibility.
2908 ; Nonzero if we should do (language-dependent) alias analysis.
2909 ; Typically, this analysis will assume that expressions of certain
2910 ; types do not alias expressions of certain other types. Only used
2911 ; if alias analysis (in general) is enabled.
2913 Common Var(flag_strict_aliasing) Optimization
2914 Assume strict aliasing rules apply.
2918 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2921 Common Var(flag_sync_libcalls) Init(1)
2922 Implement __atomic operations via libcalls to legacy __sync functions.
2925 Common Var(flag_syntax_only)
2926 Check for syntax errors, then stop.
2929 Common Var(flag_test_coverage)
2930 Create data files needed by \"gcov\".
2933 Common Var(flag_thread_jumps) Optimization
2934 Perform jump threading optimizations.
2937 Common Var(time_report)
2938 Report the time taken by each compiler pass.
2940 ftime-report-details
2941 Common Var(time_report_details)
2942 Record times taken by sub-phases separately.
2945 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2946 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2949 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2952 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2955 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2958 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2961 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2964 Common Var(flag_toplevel_reorder) Init(2) Optimization
2965 Reorder top level functions, variables, and asms.
2968 Common Var(flag_tracer) Optimization
2969 Perform superblock formation via tail duplication.
2972 Common Var(flag_trampolines) Init(HEAP_TRAMPOLINES_INIT)
2973 For targets that normally need trampolines for nested functions, always
2974 generate them instead of using descriptors.
2977 Common Joined RejectNegative Enum(trampoline_impl) Var(flag_trampoline_impl) Init(HEAP_TRAMPOLINES_INIT ? TRAMPOLINE_IMPL_HEAP : TRAMPOLINE_IMPL_STACK)
2978 Whether trampolines are generated in executable memory rather than
2982 Name(trampoline_impl) Type(enum trampoline_impl) UnknownError(unknown trampoline implementation %qs)
2985 Enum(trampoline_impl) String(stack) Value(TRAMPOLINE_IMPL_STACK)
2988 Enum(trampoline_impl) String(heap) Value(TRAMPOLINE_IMPL_HEAP)
2991 ; Zero means that floating-point math operations cannot generate a
2992 ; (user-visible) trap. This is the case, for example, in nonstop
2993 ; IEEE 754 arithmetic.
2995 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
2996 Assume floating-point operations can trap.
2999 Common Var(flag_trapv) Optimization
3000 Trap for signed overflow in addition, subtraction and multiplication.
3003 Common Var(flag_tree_ccp) Optimization
3004 Enable SSA-CCP optimization on trees.
3007 Common Var(flag_tree_bit_ccp) Optimization
3008 Enable SSA-BIT-CCP optimization on trees.
3012 Does nothing. Preserved for backward compatibility.
3015 Common Var(flag_tree_ch) Optimization
3016 Enable loop header copying on trees.
3018 ftree-coalesce-inlined-vars
3019 Common Ignore RejectNegative
3020 Does nothing. Preserved for backward compatibility.
3023 Common Var(flag_tree_coalesce_vars) Optimization
3024 Enable SSA coalescing of user variables.
3028 Does nothing. Preserved for backward compatibility.
3031 Common Var(flag_tree_copy_prop) Optimization
3032 Enable copy propagation on trees.
3034 ftree-store-copy-prop
3036 Does nothing. Preserved for backward compatibility.
3039 Common Var(flag_tree_cselim) Optimization
3040 Transform condition stores into unconditional ones.
3042 ftree-switch-conversion
3043 Common Var(flag_tree_switch_conversion) Optimization
3044 Perform conversions of switch initializations.
3047 Common Var(flag_tree_dce) Optimization
3048 Enable SSA dead code elimination optimization on trees.
3050 ftree-dominator-opts
3051 Common Var(flag_tree_dom) Optimization
3052 Enable dominator optimizations.
3055 Common Var(flag_tree_tail_merge) Optimization
3056 Enable tail merging on trees.
3059 Common Var(flag_tree_dse) Optimization
3060 Enable dead store elimination.
3063 Common Var(flag_tree_forwprop) Init(1) Optimization
3064 Enable forward propagation on trees.
3067 Common Var(flag_tree_fre) Optimization
3068 Enable Full Redundancy Elimination (FRE) on trees.
3071 Common Var(flag_optimize_strlen) Optimization
3072 Enable string length optimizations on trees.
3074 fisolate-erroneous-paths-dereference
3075 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
3076 Detect paths that trigger erroneous or undefined behavior due to
3077 dereferencing a null pointer. Isolate those paths from the main control
3078 flow and turn the statement with erroneous or undefined behavior into a trap.
3080 fisolate-erroneous-paths-attribute
3081 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
3082 Detect paths that trigger erroneous or undefined behavior due to a null value
3083 being used in a way forbidden by a returns_nonnull or nonnull
3084 attribute. Isolate those paths from the main control flow and turn the
3085 statement with erroneous or undefined behavior into a trap.
3087 ftree-loop-distribution
3088 Common Var(flag_tree_loop_distribution) Optimization
3089 Enable loop distribution on trees.
3091 ftree-loop-distribute-patterns
3092 Common Var(flag_tree_loop_distribute_patterns) Optimization
3093 Enable loop distribution for patterns transformed into a library call.
3096 Common Var(flag_tree_loop_im) Init(1) Optimization
3097 Enable loop invariant motion on trees.
3100 Common Alias(floop-nest-optimize)
3101 Enable loop nest transforms. Same as -floop-nest-optimize.
3104 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
3105 Create canonical induction variables in loops.
3108 Common Var(flag_tree_loop_optimize) Init(1) Optimization
3109 Enable loop optimizations on tree level.
3111 ftree-parallelize-loops=
3112 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
3113 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
3116 Common Var(flag_tree_phiprop) Init(1) Optimization
3117 Enable hoisting loads from conditional pointers.
3120 Common Var(flag_tree_pre) Optimization
3121 Enable SSA-PRE optimization on trees.
3124 Common Var(flag_tree_partial_pre) Optimization
3125 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
3128 Common Var(flag_tree_pta) Optimization
3129 Perform function-local points-to analysis on trees.
3132 Common Var(flag_tree_reassoc) Init(1) Optimization
3133 Enable reassociation on tree level.
3137 Does nothing. Preserved for backward compatibility.
3140 Common Var(flag_tree_sink) Optimization
3141 Enable SSA code sinking on trees.
3144 Common Var(flag_tree_slsr) Optimization
3145 Perform straight-line strength reduction.
3148 Common Var(flag_tree_sra) Optimization
3149 Perform scalar replacement of aggregates.
3152 Common Var(flag_tree_ter) Optimization
3153 Replace temporary expressions in the SSA->normal pass.
3156 Common Var(flag_tree_live_range_split) Optimization
3157 Perform live range splitting during the SSA->normal pass.
3160 Common Var(flag_tree_vrp) Init(0) Optimization
3161 Perform Value Range Propagation on trees.
3164 Common Var(flag_split_paths) Init(0) Optimization
3165 Split paths leading to loop backedges.
3167 funconstrained-commons
3168 Common Var(flag_unconstrained_commons) Optimization
3169 Assume common declarations may be overridden with ones with a larger
3173 Common Var(flag_unit_at_a_time) Init(1)
3174 Compile whole compilation unit at a time.
3177 Common Var(flag_unreachable_traps) Optimization
3178 Trap on __builtin_unreachable instead of using it for optimization.
3181 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3182 Perform loop unrolling when iteration count is known.
3185 Common Var(flag_unroll_all_loops) Optimization
3186 Perform loop unrolling for all loops.
3188 funroll-completely-grow-size
3189 Undocumented Var(flag_cunroll_grow_size) Optimization
3190 ; Internal undocumented flag, allow size growth during complete unrolling
3192 ; Nonzero means that loop optimizer may assume that the induction variables
3193 ; that control loops do not overflow and that the loops with nontrivial
3194 ; exit condition are not infinite
3195 funsafe-loop-optimizations
3197 Does nothing. Preserved for backward compatibility.
3200 Common Var(flag_associative_math) SetByCombined Optimization
3201 Allow optimization for floating-point arithmetic which may change the
3202 result of the operation due to rounding.
3205 Common Var(flag_reciprocal_math) SetByCombined Optimization
3206 Same as -fassociative-math for expressions which include division.
3208 ; Nonzero means that unsafe floating-point math optimizations are allowed
3209 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
3210 ; are allowed to assume that their arguments and results are "normal"
3211 ; (e.g., nonnegative for SQRT).
3212 funsafe-math-optimizations
3213 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3214 Allow math optimizations that may violate IEEE or ISO standards.
3217 Common Var(flag_unswitch_loops) Optimization
3218 Perform loop unswitching.
3221 Common Var(flag_split_loops) Optimization
3222 Perform loop splitting.
3224 fversion-loops-for-strides
3225 Common Var(flag_version_loops_for_strides) Optimization
3226 Version loops based on whether indices have a stride of one.
3229 Common Var(flag_unwind_tables) Optimization
3230 Just generate unwind tables for exception handling.
3233 Common Driver Negative(fuse-ld=gold)
3234 Use the bfd linker instead of the default linker.
3237 Common Driver Negative(fuse-ld=bfd)
3238 Use the gold linker instead of the default linker.
3241 Common Driver Negative(fuse-ld=lld)
3242 Use the lld LLVM linker instead of the default linker.
3245 Common Driver Negative(fuse-ld=mold)
3246 Use the Modern linker (MOLD) linker instead of the default linker.
3249 Common Undocumented Var(flag_use_linker_plugin)
3251 ; Positive if we should track variables, negative if we should run
3252 ; the var-tracking pass only to discard debug annotations, zero if
3253 ; we're not to run it.
3255 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3256 Perform variable tracking.
3258 ; Positive if we should track variables at assignments, negative if
3259 ; we should run the var-tracking pass only to discard debug
3261 fvar-tracking-assignments
3262 Common Var(flag_var_tracking_assignments) PerFunction
3263 Perform variable tracking by annotating assignments.
3265 ; Nonzero if we should toggle flag_var_tracking_assignments after
3266 ; processing options and computing its default. */
3267 fvar-tracking-assignments-toggle
3268 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3269 Toggle -fvar-tracking-assignments.
3271 ; Positive if we should track uninitialized variables, negative if
3272 ; we should run the var-tracking pass only to discard debug
3274 fvar-tracking-uninit
3275 Common Var(flag_var_tracking_uninit) PerFunction
3276 Perform variable tracking and also tag variables that are uninitialized.
3278 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3280 Common Var(flag_tree_vectorize) Optimization
3281 Enable vectorization on trees.
3283 ftree-vectorizer-verbose=
3284 Common Joined RejectNegative Ignore
3285 Does nothing. Preserved for backward compatibility.
3287 ftree-loop-vectorize
3288 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3289 Enable loop vectorization on trees.
3292 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3293 Enable basic block vectorization (SLP) on trees.
3296 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3297 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the cost model for vectorization.
3300 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3301 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the vectorization cost model for code marked with a simd directive.
3304 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3307 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3310 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3313 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3316 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3319 Common Alias(fvect-cost-model=,dynamic,unlimited)
3320 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
3322 ftree-vect-loop-version
3324 Does nothing. Preserved for backward compatibility.
3327 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3328 Enable copy propagation of scalar-evolution information.
3330 ftrivial-auto-var-init=
3331 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3332 -ftrivial-auto-var-init=[uninitialized|pattern|zero] Add initializations to automatic variables.
3335 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3338 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3341 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3344 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3346 ; -fverbose-asm causes extra commentary information to be produced in
3347 ; the generated assembly code (to make it more readable). This option
3348 ; is generally only of use to those who actually need to read the
3349 ; generated assembly code (perhaps while debugging the compiler itself).
3350 ; -fno-verbose-asm, the default, causes the extra information
3351 ; to not be added and is useful when comparing two assembler files.
3353 Common Var(flag_verbose_asm)
3354 Add extra commentary to assembler output.
3357 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3358 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
3361 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3364 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3367 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3370 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3373 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3376 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3377 Validate vtable pointers before using them.
3380 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3383 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3386 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3389 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3392 Common Var(flag_vtv_counts)
3393 Output vtable verification counters.
3396 Common Var(flag_vtv_debug)
3397 Output vtable verification pointer sets information.
3400 Common Var(flag_value_profile_transformations) Optimization
3401 Use expression value profiles in optimizations.
3404 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3405 Construct webs and split unrelated uses of single variable.
3407 ftree-builtin-call-dce
3408 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3409 Enable conditional dead code elimination for builtin calls.
3412 Common Var(flag_whole_program) Init(0)
3413 Perform whole program optimizations.
3416 Common Var(flag_wrapv_pointer) Optimization
3417 Assume pointer overflow wraps around.
3420 Common Var(flag_wrapv) Optimization
3421 Assume signed arithmetic overflow wraps around.
3423 fzero-initialized-in-bss
3424 Common Var(flag_zero_initialized_in_bss) Init(1)
3425 Put zero initialized data in the bss section.
3427 fzero-call-used-regs=
3428 Common RejectNegative Joined
3429 Clear call-used registers upon function return.
3432 Common Driver RejectNegative JoinedOrMissing
3433 Generate debug information in default format.
3436 Common Driver Var(dwarf2out_as_loc_support)
3437 Assume assembler support for (DWARF2+) .loc directives.
3440 Common Driver Var(dwarf2out_as_locview_support)
3441 Assume assembler support for view in (DWARF2+) .loc directives.
3444 Common Driver JoinedOrMissing
3445 Generate debug information in CodeView format.
3448 Common Driver WarnRemoved
3449 Does nothing. Preserved for backward compatibility.
3452 Common Driver WarnRemoved
3453 Does nothing. Preserved for backward compatibility.
3456 Common Driver WarnRemoved
3457 Does nothing. Preserved for backward compatibility.
3460 Common Driver WarnRemoved
3461 Does nothing. Preserved for backward compatibility.
3464 Common Driver Var(debug_column_info,1) Init(1)
3465 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3467 ; The CTF generation process feeds off DWARF dies. This option implicitly
3468 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3470 Common Driver RejectNegative JoinedOrMissing
3471 Generate CTF debug information at default level.
3474 Common Driver RejectNegative JoinedOrMissing
3475 Generate BTF debug information at default level.
3478 Common Driver JoinedOrMissing RejectNegative
3479 Generate debug information in default version of DWARF format.
3482 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT) RejectNegative
3483 Generate debug information in DWARF v2 (or later) format.
3486 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3487 Use 32-bit DWARF format when emitting DWARF debug information.
3490 Common Driver Var(dwarf_offset_size,8) RejectNegative
3491 Use 64-bit DWARF format when emitting DWARF debug information.
3494 Common Driver JoinedOrMissing RejectNegative
3495 Generate debug information in default extended format.
3498 Common Driver Var(debug_inline_points)
3499 Generate extended entry point information for inlined functions.
3501 ginternal-reset-location-views
3502 Common Driver Var(debug_internal_reset_location_views) Init(2)
3503 Compute locview reset points based on insn length estimates.
3506 RejectNegative Joined Undocumented
3507 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3510 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3511 Don't generate DWARF pubnames and pubtypes sections.
3514 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3515 Generate DWARF pubnames and pubtypes sections.
3518 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3519 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3521 grecord-gcc-switches
3522 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3523 Record gcc command line switches in DWARF DW_AT_producer.
3526 Common Driver Var(dwarf_split_debug_info) Init(0)
3527 Generate debug information in separate .dwo files.
3530 Common Driver WarnRemoved
3531 Does nothing. Preserved for backward compatibility.
3534 Common Driver WarnRemoved
3535 Does nothing. Preserved for backward compatibility.
3537 gstatement-frontiers
3538 Common Driver Var(debug_nonbind_markers_p) PerFunction
3539 Emit progressive recommended breakpoint locations.
3542 Common Driver Var(dwarf_strict) Init(0)
3543 Don't emit DWARF additions beyond selected version.
3546 Common Driver Var(flag_describe_dies) Init(0)
3547 Add description attributes to some DWARF DIEs that have no name attribute.
3550 Common Driver Var(flag_gtoggle)
3551 Toggle debug information generation.
3553 gvariable-location-views
3554 Common Driver Var(debug_variable_location_views, 1)
3555 Augment variable location lists with progressive views.
3557 gvariable-location-views=incompat5
3558 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3561 Common Driver JoinedOrMissing RejectNegative
3562 Generate debug information in VMS format.
3565 Common Driver WarnRemoved
3566 Does nothing. Preserved for backward compatibility.
3569 Common Driver JoinedOrMissing WarnRemoved
3570 Does nothing. Preserved for backward compatibility.
3573 Name(compressed_debug_sections) Type(int)
3575 ; Since -gz= is completely handled in specs, the values aren't used and we
3576 ; assign arbitrary constants.
3578 Enum(compressed_debug_sections) String(none) Value(0)
3581 Enum(compressed_debug_sections) String(zlib) Value(1)
3584 Enum(compressed_debug_sections) String(zstd) Value(2)
3587 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3591 Generate compressed debug sections.
3594 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3595 -gz=<format> Generate compressed debug sections in format <format>.
3598 Driver Joined Separate
3601 Common Joined Var(plugindir_string) Init(0)
3602 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3605 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3606 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3609 Driver Joined Separate
3614 no-canonical-prefixes
3633 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3634 -o <file> Place output into <file>.
3637 Common Var(profile_flag)
3638 Enable function profiling.
3641 Driver Var(pass_exit_codes)
3644 Common Alias(Wpedantic)
3647 Common Var(flag_pedantic_errors)
3648 Like -pedantic but issue them as errors.
3654 Driver Var(use_pipes)
3657 Driver JoinedOrMissing Var(print_file_name)
3659 print-libgcc-file-name
3662 print-multi-directory
3663 Driver Var(print_multi_directory)
3666 Driver Var(print_multi_lib)
3668 print-multi-os-directory
3669 Driver Var(print_multi_os_directory)
3672 Driver Var(print_multiarch)
3675 Driver JoinedOrMissing Var(print_prog_name)
3678 Driver Var(print_search_dirs)
3681 Driver Var(print_sysroot)
3683 print-sysroot-headers-suffix
3684 Driver Var(print_sysroot_headers_suffix)
3687 Common Var(quiet_flag) RejectDriver
3688 Do not display functions compiled or elapsed time.
3706 Driver Var(report_times)
3709 Driver JoinedOrMissing
3712 Driver Joined Separate
3716 ; C option, but driver must not handle as "-u ndef".
3719 Common Driver Var(verbose_flag)
3720 Enable verbose output.
3723 Common Var(version_flag) RejectDriver
3724 Display the compiler's version.
3727 Common Var(inhibit_warnings)
3731 Driver Separate Var(wrapper_string)
3734 Driver Joined Separate
3737 Driver RejectNegative Negative(static-pie)
3738 Create a shared library.
3744 Driver Separate Alias(specs=)
3757 ; Documented for Fortran, but always accepted by driver.
3761 ; Documented for Modula-2, but always accepted by driver.
3765 ; Documented for D, but always accepted by driver.
3769 ; Documented for Fortran, but always accepted by driver.
3776 ; Documented for Go, but always accepted by driver.
3797 Driver RejectNegative Negative(shared)
3798 Don't create a dynamically linked position independent executable.
3801 Driver RejectNegative Negative(no-pie)
3802 Create a dynamically linked position independent executable.
3805 Driver RejectNegative Negative(pie)
3806 Create a static position independent executable.
3809 Driver Joined Separate
3812 Common Var(flag_ipa_ra) Optimization
3813 Use caller save register across calls if possible.
3815 ; This comment is to ensure we retain the blank line above.