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 ; Mangles constraints on function templates.
1024 ; Default in G++ 14.
1026 ; Additional positive integers will be assigned as new versions of
1027 ; the ABI become the default version of the ABI.
1029 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1030 The version of the C++ ABI in use.
1032 faggressive-loop-optimizations
1033 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1034 Aggressively optimize loops using language constraints.
1037 Common Var(flag_align_functions) Optimization
1038 Align the start of functions.
1041 Common RejectNegative Joined Var(str_align_functions) Optimization
1043 flimit-function-alignment
1044 Common Var(flag_limit_function_alignment) Optimization Init(0)
1047 Common Var(flag_align_jumps) Optimization
1048 Align labels which are only reached by jumping.
1051 Common RejectNegative Joined Var(str_align_jumps) Optimization
1054 Common Var(flag_align_labels) Optimization
1058 Common RejectNegative Joined Var(str_align_labels) Optimization
1061 Common Var(flag_align_loops) Optimization
1062 Align the start of loops.
1065 Common RejectNegative Joined Var(str_align_loops) Optimization
1067 fallow-store-data-races
1068 Common Var(flag_store_data_races) Optimization
1069 Allow the compiler to introduce new data races on stores.
1072 Common Var(flag_analyzer)
1073 Enable static analysis pass.
1077 Does nothing. Preserved for backward compatibility.
1081 Does nothing. Preserved for backward compatibility.
1083 fargument-noalias-global
1085 Does nothing. Preserved for backward compatibility.
1087 fargument-noalias-anything
1089 Does nothing. Preserved for backward compatibility.
1092 Common Driver Joined
1093 Select what to sanitize.
1096 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1097 Select type of coverage sanitization.
1100 Name(sanitize_coverage) Type(int)
1103 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1106 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1108 fasan-shadow-offset=
1109 Common Joined RejectNegative Var(common_deferred_options) Defer
1110 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1113 Common Joined RejectNegative Var(common_deferred_options) Defer
1114 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1115 in user-defined sections.
1119 After diagnosing undefined behavior attempt to continue execution.
1123 This switch is deprecated; use -fsanitize-recover= instead.
1126 Common Driver Joined
1127 Use traps instead of diagnostics of undefined behavior sanitizers.
1132 fsanitize-address-use-after-scope
1133 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1135 fsanitize-undefined-trap-on-error
1136 Common Driver Alias(fsanitize-trap)
1137 This switch is deprecated; use -fsanitize-trap= instead.
1139 fasynchronous-unwind-tables
1140 Common Var(flag_asynchronous_unwind_tables) Optimization
1141 Generate unwind tables that are exact at each instruction boundary.
1144 Common Var(flag_auto_inc_dec) Init(1) Optimization
1145 Generate auto-inc/dec instructions.
1148 Common Var(flag_auto_profile)
1149 Use sample profile information for call graph node weights. The default
1150 profile file is fbdata.afdo in 'pwd'.
1153 Common Joined RejectNegative Var(auto_profile_file)
1154 Use sample profile information for call graph node weights. The profile
1155 file is specified in the argument.
1157 ; -fcheck-bounds causes gcc to generate array bounds checks.
1158 ; For C, C++ and ObjC: defaults off.
1159 ; For Java: defaults to on.
1160 ; For Fortran: defaults to off.
1162 Common Var(flag_bounds_check)
1163 Generate code to check bounds before indexing arrays.
1166 Common Var(flag_branch_on_count_reg) Optimization
1167 Replace add, compare, branch with branch on count register.
1169 fbranch-probabilities
1170 Common Var(flag_branch_probabilities) Optimization
1171 Use profiling information for branch probabilities.
1173 fbranch-target-load-optimize
1175 Does nothing. Preserved for backward compatibility.
1177 fbranch-target-load-optimize2
1179 Does nothing. Preserved for backward compatibility.
1183 Does nothing. Preserved for backward compatibility.
1186 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1187 Output callgraph information on a per-file basis.
1190 Common RejectNegative Joined
1191 Output callgraph information on a per-file basis with decorations.
1194 Common Joined RejectNegative Var(common_deferred_options) Defer
1195 -fcall-saved-<register> Mark <register> as being preserved across functions.
1198 Common Joined RejectNegative Var(common_deferred_options) Defer
1199 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1201 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1202 ; be saved across function calls, if that produces overall better code.
1203 ; Optional now, so people can test it.
1205 Common Var(flag_caller_saves) Optimization
1206 Save registers around function calls.
1210 This switch is deprecated; do not use.
1213 Common Var(flag_check_new)
1214 Check the return value of new in C++.
1217 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1218 Perform internal consistency checkings.
1221 Common Joined RejectNegative UInteger Var(flag_checking)
1222 Perform internal consistency checkings.
1225 Common Var(common_deferred_options) Defer
1226 For -f*-prefix-map= options compare canonicalized pathnames rather than just strings.
1229 Common Var(flag_code_hoisting) Optimization
1230 Enable code hoisting.
1232 fcombine-stack-adjustments
1233 Common Var(flag_combine_stack_adjustments) Optimization
1234 Looks for opportunities to reduce stack adjustments and stack references.
1237 Common Var(flag_no_common,0) Init(1)
1238 Put uninitialized globals in the common section.
1242 ; Converted by the driver to -fcompare-debug= options.
1245 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1246 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1248 fcompare-debug-second
1249 Common Driver RejectNegative Var(flag_compare_debug)
1250 Run only the second compilation of -fcompare-debug.
1253 Common Var(flag_compare_elim_after_reload) Optimization
1254 Perform comparison elimination after register allocation has finished.
1257 Common Var(flag_conserve_stack) Optimization
1258 Do not perform optimizations increasing noticeably stack usage.
1261 Common Var(flag_cprop_registers) Optimization
1262 Perform a register copy-propagation optimization pass.
1265 Target Bool Var(flag_fold_mem_offsets) Init(1)
1266 Fold instructions calculating memory offsets to the memory access instruction if possible.
1269 Common Var(flag_crossjumping) Optimization
1270 Perform cross-jumping optimization.
1273 Common Var(flag_cse_follow_jumps) Optimization
1274 When running CSE, follow jumps to their targets.
1278 Does nothing. Preserved for backward compatibility.
1281 Common Var(flag_cx_limited_range) Optimization SetByCombined
1282 Omit range reduction step when performing complex division.
1285 Common Var(flag_cx_fortran_rules) Optimization
1286 Complex multiplication and division follow Fortran rules.
1289 Common Var(flag_data_sections)
1290 Place data items into their own section.
1293 Common Var(flag_dbg_cnt_list)
1294 List all available debugging counters with their limits and counts.
1297 Common RejectNegative Joined Var(common_deferred_options) Defer
1298 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1301 Common Joined RejectNegative Var(common_deferred_options) Defer
1302 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1305 Common Joined RejectNegative Var(common_deferred_options) Defer
1306 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1308 fdebug-types-section
1309 Common Var(flag_debug_types_section) Init(0)
1310 Output .debug_types section when using DWARF v4 debuginfo.
1312 ; Nonzero for -fdefer-pop: don't pop args after each function call
1313 ; instead save them up to pop many calls' args with one insns.
1315 Common Var(flag_defer_pop) Optimization
1316 Defer popping functions args from stack until later.
1319 Common Var(flag_delayed_branch) Optimization
1320 Attempt to fill delay slots of branch instructions.
1322 fdelete-dead-exceptions
1323 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1324 Delete dead instructions that may throw exceptions.
1326 fdelete-null-pointer-checks
1327 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1328 Delete useless null pointer checks.
1330 fdevirtualize-at-ltrans
1331 Common Var(flag_ltrans_devirtualize)
1332 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1334 fdevirtualize-speculatively
1335 Common Var(flag_devirtualize_speculatively) Optimization
1336 Perform speculative devirtualization.
1339 Common Var(flag_devirtualize) Optimization
1340 Try to convert virtual calls to direct ones.
1342 fdiagnostics-show-location=
1343 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1344 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1346 ; Required for these enum values.
1351 Name(diagnostic_prefixing_rule) Type(int)
1354 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1357 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1359 fdiagnostics-show-caret
1360 Common Var(flag_diagnostics_show_caret) Init(1)
1361 Show the source line with a caret indicating the column.
1363 fdiagnostics-show-labels
1364 Common Var(flag_diagnostics_show_labels) Init(1)
1365 Show labels annotating ranges of source code when showing source.
1367 fdiagnostics-show-line-numbers
1368 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1369 Show line numbers in the left margin when showing source.
1372 Common Alias(fdiagnostics-color=,always,never)
1376 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1377 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1379 ; Required for these enum values.
1384 Name(diagnostic_color_rule) Type(int)
1387 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1390 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1393 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1395 fdiagnostics-json-formatting
1396 Common Var(flag_diagnostics_json_formatting) Init(1)
1397 Enable formatting of JSON output.
1400 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1401 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1403 ; Required for these enum values.
1408 Name(diagnostic_url_rule) Type(int)
1411 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1414 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1417 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1419 fdiagnostics-column-unit=
1420 Common Joined RejectNegative Enum(diagnostics_column_unit)
1421 -fdiagnostics-column-unit=[display|byte] Select whether column numbers are output as display columns (default) or raw bytes.
1423 fdiagnostics-column-origin=
1424 Common Joined RejectNegative UInteger
1425 -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.
1427 fdiagnostics-format=
1428 Common Joined RejectNegative Enum(diagnostics_output_format)
1429 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file] Select output format.
1431 fdiagnostics-escape-format=
1432 Common Joined RejectNegative Enum(diagnostics_escape_format)
1433 -fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1435 ; Required for these enum values.
1440 Name(diagnostics_column_unit) Type(int)
1443 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1446 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1449 Name(diagnostics_escape_format) Type(int)
1452 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1455 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1458 Name(diagnostics_output_format) Type(int)
1461 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1464 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1467 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1470 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1473 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1476 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1478 fdiagnostics-parseable-fixits
1479 Common Var(flag_diagnostics_parseable_fixits)
1480 Print fix-it hints in machine-readable form.
1482 fdiagnostics-generate-patch
1483 Common Var(flag_diagnostics_generate_patch)
1484 Print fix-it hints to stderr in unified diff format.
1486 fdiagnostics-show-option
1487 Common Var(flag_diagnostics_show_option) Init(1)
1488 Amend appropriate diagnostic messages with the command line option that controls them.
1490 fdiagnostics-show-cwe
1491 Common Var(flag_diagnostics_show_cwe) Init(1)
1492 Print CWE identifiers for diagnostic messages, where available.
1494 fdiagnostics-show-rules
1495 Common Var(flag_diagnostics_show_rules) Init(1)
1496 Print any rules associated with diagnostic messages.
1498 fdiagnostics-path-format=
1499 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1500 Specify how to print any control-flow path associated with a diagnostic.
1502 fdiagnostics-plain-output
1503 Driver Common RejectNegative
1504 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1507 Common Joined RejectNegative UInteger
1508 -ftabstop=<number> Distance between tab stops for column reporting.
1511 Name(diagnostic_path_format) Type(int)
1514 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1517 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1520 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1522 fdiagnostics-show-path-depths
1523 Common Var(flag_diagnostics_show_path_depths) Init(0)
1524 Show stack depths of events in paths.
1526 fdiagnostics-text-art-charset=
1527 Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1528 -fdiagnostics-text-art-charset=[none|ascii|unicode|emoji] Determine which characters to use in text arg diagrams.
1531 Name(diagnostic_text_art_charset) Type(int)
1534 Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
1537 Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
1540 Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
1543 Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1545 fdiagnostics-minimum-margin-width=
1546 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1547 Set minimum width of left margin of source code when showing source.
1550 Common Joined RejectNegative Var(common_deferred_options) Defer
1551 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 Disable an optimization pass.
1554 Common Joined RejectNegative Var(common_deferred_options) Defer
1555 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 Enable an optimization pass.
1558 Common Joined RejectNegative Var(common_deferred_options) Defer
1559 -fdump-<type> Dump various compiler internals to a file.
1562 Driver RejectNegative
1565 Common RejectNegative Joined Var(flag_dump_final_insns)
1566 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1569 Common RejectNegative Joined Var(flag_dump_go_spec)
1570 -fdump-go-spec=filename Write all declarations to file as Go code.
1573 Common Var(flag_dump_noaddr)
1574 Suppress output of addresses in debugging dumps.
1577 Common Driver Var(flag_report_bug)
1578 Collect and dump debug information into temporary file if ICE in C/C++
1581 fdump-internal-locations
1582 Common Var(flag_dump_locations) Init(0)
1583 Dump detailed information on GCC's internal representation of source code locations.
1586 Common Var(flag_dump_passes) Init(0)
1587 Dump optimization passes.
1590 Common Var(flag_dump_unnumbered)
1591 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1593 fdump-unnumbered-links
1594 Common Var(flag_dump_unnumbered_links)
1595 Suppress output of previous and next insn numbers in debugging dumps.
1598 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1599 Enable CFI tables via GAS assembler directives.
1602 Common Var(flag_early_inlining) Init(1) Optimization
1603 Perform early inlining.
1605 feliminate-dwarf2-dups
1607 Does nothing. Preserved for backward compatibility.
1610 Common Var(flag_ipa_sra) Init(0) Optimization
1611 Perform interprocedural reduction of aggregates.
1613 feliminate-unused-debug-symbols
1614 Common Var(flag_debug_only_used_symbols) Init(1)
1615 Perform unused symbol elimination in debug info.
1617 feliminate-unused-debug-types
1618 Common Var(flag_eliminate_unused_debug_types) Init(1)
1619 Perform unused type elimination in debug info.
1621 femit-class-debug-always
1622 Common Var(flag_emit_class_debug_always) Init(0)
1623 Do not suppress C++ class debug information.
1626 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1627 Enable exception handling.
1629 fexpensive-optimizations
1630 Common Var(flag_expensive_optimizations) Optimization
1631 Perform a number of minor, expensive optimizations.
1634 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1635 -fexcess-precision=[fast|standard|16] Specify handling of excess floating-point precision.
1638 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1641 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1644 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1647 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1649 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1650 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1651 fpermitted-flt-eval-methods=
1652 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1653 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1656 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)
1659 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1662 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1668 Common Var(flag_fat_lto_objects)
1669 Output lto objects containing both the intermediate language and binary output.
1672 Common Var(flag_finite_math_only) Optimization SetByCombined
1673 Assume no NaNs or infinities are generated.
1676 Common Var(flag_finite_loops) Optimization Init(0)
1677 Assume that loops with an exit will terminate and not loop indefinitely.
1680 Common Joined RejectNegative Var(common_deferred_options) Defer
1681 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1684 Common Var(flag_float_store) Optimization
1685 Don't allocate floats and doubles in extended-precision registers.
1689 Does nothing. Preserved for backward compatibility.
1692 Common Var(flag_forward_propagate) Optimization
1693 Perform a forward propagation pass on RTL.
1696 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1697 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1700 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1703 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1706 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_ON)
1709 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1711 ffp-int-builtin-inexact
1712 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1713 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1715 ; Nonzero means don't put addresses of constant functions in registers.
1716 ; Used for compiling the Unix kernel, where strange substitutions are
1717 ; done on the assembly output.
1719 Common Var(flag_no_function_cse,0) Optimization
1720 Allow function addresses to be held in registers.
1723 Common Var(flag_function_sections)
1724 Place each function into its own section.
1727 Common Var(flag_gcse) Optimization
1728 Perform global common subexpression elimination.
1731 Common Var(flag_gcse_lm) Init(1) Optimization
1732 Perform enhanced load motion during global common subexpression elimination.
1735 Common Var(flag_gcse_sm) Init(0) Optimization
1736 Perform store motion after global common subexpression elimination.
1739 Common Var(flag_gcse_las) Init(0) Optimization
1740 Perform redundant load after store elimination in global common subexpression
1744 Common Var(flag_gcse_after_reload) Optimization
1745 Perform global common subexpression elimination after register allocation has
1749 Name(dwarf_gnat_encodings) Type(int)
1752 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1755 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1758 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1761 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1762 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1764 ; This option is not documented yet as its semantics will change.
1766 Common Var(flag_graphite) Optimization
1767 Enable in and out of Graphite representation.
1770 Common Var(flag_graphite_identity) Optimization
1771 Enable Graphite Identity transformation.
1773 fhoist-adjacent-loads
1774 Common Var(flag_hoist_adjacent_loads) Optimization
1775 Enable hoisting adjacent loads to encourage generating conditional move
1779 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1780 ; Always keep a pointer to a live memory block
1783 Common Var(flag_large_source_files) Init(0)
1784 Improve GCC's ability to track column numbers in large source files,
1785 at the expense of slower compilation.
1787 floop-parallelize-all
1788 Common Var(flag_loop_parallelize_all) Optimization
1789 Mark all loops as parallel.
1792 Common Alias(floop-nest-optimize)
1793 Enable loop nest transforms. Same as -floop-nest-optimize.
1796 Common Var(flag_loop_interchange) Optimization
1797 Enable loop interchange on trees.
1800 Common Alias(floop-nest-optimize)
1801 Enable loop nest transforms. Same as -floop-nest-optimize.
1803 floop-unroll-and-jam
1804 Common Var(flag_unroll_jam) Optimization
1805 Perform unroll-and-jam on loops.
1809 Enable support for GNU transactional memory.
1812 Common Var(flag_gnu_unique) Init(1)
1813 Use STB_GNU_UNIQUE if supported by the assembler.
1817 Does nothing. Preserved for backward compatibility.
1820 Common Var(flag_loop_nest_optimize) Optimization
1821 Enable the loop nest optimizer.
1823 fstrict-volatile-bitfields
1824 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1825 Force bitfield accesses to match their type width.
1828 Common Var(flag_store_merging) Optimization
1829 Merge adjacent stores.
1831 fguess-branch-probability
1832 Common Var(flag_guess_branch_prob) Optimization
1833 Enable guessing of branch probabilities.
1836 Common Driver Var(flag_hardened)
1837 Enable various security-relevant flags.
1840 Common Var(flag_harden_compares) Optimization
1841 Harden conditionals not used in branches, checking reversed conditions.
1843 fharden-conditional-branches
1844 Common Var(flag_harden_conditional_branches) Optimization
1845 Harden conditional branches by checking reversed conditions.
1847 fharden-control-flow-redundancy
1848 Common Var(flag_harden_control_flow_redundancy) Optimization
1849 Harden control flow by recording and checking execution paths.
1852 Common Var(flag_harden_control_flow_redundancy_skip_leaf) Optimization
1853 Disable CFR in leaf functions.
1855 fhardcfr-check-returning-calls
1856 Common Var(flag_harden_control_flow_redundancy_check_returning_calls) Init(-1) Optimization
1857 Check CFR execution paths also before calls followed by returns of their results.
1859 fhardcfr-check-exceptions
1860 Common Var(flag_harden_control_flow_redundancy_check_exceptions) Init(-1) Optimization
1861 Check CFR execution paths also when exiting a function through an exception.
1863 fhardcfr-check-noreturn-calls=
1864 Common Joined RejectNegative Enum(hardcfr_check_noreturn_calls) Var(flag_harden_control_flow_redundancy_check_noreturn) Init(HCFRNR_UNSPECIFIED) Optimization
1865 -fhardcfr-check-noreturn-calls=[always|no-xthrow|nothrow|never] Check CFR execution paths also before calling noreturn functions.
1868 Name(hardcfr_check_noreturn_calls) Type(enum hardcfr_noret) UnknownError(unknown hardcfr noreturn checking level %qs)
1871 Enum(hardcfr_check_noreturn_calls) String(never) Value(HCFRNR_NEVER)
1874 Enum(hardcfr_check_noreturn_calls) String(nothrow) Value(HCFRNR_NOTHROW)
1877 Enum(hardcfr_check_noreturn_calls) String(no-xthrow) Value(HCFRNR_NO_XTHROW)
1880 Enum(hardcfr_check_noreturn_calls) String(always) Value(HCFRNR_ALWAYS)
1882 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1883 ; Generate position-independent code for executables if possible
1884 ; On SVR4 targets, it also controls whether or not to emit a
1885 ; string identifying the compiler.
1887 Common Var(flag_no_ident,0)
1888 Process #ident directives.
1891 Common Var(flag_if_conversion) Optimization
1892 Perform conversion of conditional jumps to branchless equivalents.
1895 Common Var(flag_if_conversion2) Optimization
1896 Perform conversion of conditional jumps to conditional execution.
1899 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1900 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1903 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1906 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1909 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1912 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1914 ftree-loop-if-convert
1915 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1916 Convert conditional jumps in innermost loops to branchless equivalents.
1918 ftree-loop-if-convert-stores
1920 Does nothing. Preserved for backward compatibility.
1922 ; -finhibit-size-directive inhibits output of .size for ELF.
1923 ; This is used only for compiling crtstuff.c,
1924 ; and it may be extended to other effects
1925 ; needed for crtstuff.c on other systems.
1926 finhibit-size-directive
1927 Common Var(flag_inhibit_size_directive)
1928 Do not generate .size directives.
1931 Common Var(flag_indirect_inlining) Optimization
1932 Perform indirect inlining.
1934 ; General flag to enable inlining. Specifying -fno-inline will disable
1935 ; all inlining apart from always-inline functions.
1937 Common Var(flag_no_inline,0) Init(0) Optimization
1938 Enable inlining of function declared \"inline\", disabling disables all inlining.
1940 finline-small-functions
1941 Common Var(flag_inline_small_functions) Optimization
1942 Integrate functions into their callers when code size is known not to grow.
1945 Common Var(flag_inline_functions) Optimization
1946 Integrate functions not declared \"inline\" into their callers when profitable.
1948 finline-functions-called-once
1949 Common Var(flag_inline_functions_called_once) Optimization
1950 Integrate functions only required by their single caller.
1953 Common RejectNegative Joined Alias(finline-limit=)
1956 Common RejectNegative Joined UInteger
1957 -finline-limit=<number> Limit the size of inlined functions to <number>.
1960 Common Var(flag_inline_atomics) Init(1) Optimization
1961 Inline __atomic operations when a lock free instruction sequence is available.
1964 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_ALL) Enum(ilsop_fn) Init(ILSOP_NONE) Optimization Undocumented
1966 fno-inline-stringops
1967 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_NONE) Enum(ilsop_fn) Optimization Undocumented
1970 Common Joined Var(flag_inline_stringops) EnumSet Enum(ilsop_fn) Optimization
1971 -finline-stringops[=memcmp|memcpy|memmove|memset]
1972 Expand supported mem/str operations inline, even if against optimization.
1975 Name(ilsop_fn) Type(enum ilsop_fn) UnknownError(unavailable stringop for inlining %qs)
1977 ; This is not part of any set.
1979 ; Enum(ilsop_fn) String(none) Value(ILSOP_NONE)
1982 Enum(ilsop_fn) String(memcmp) Value(ILSOP_MEMCMP) Set(1)
1985 Enum(ilsop_fn) String(memcpy) Value(ILSOP_MEMCPY) Set(2)
1988 Enum(ilsop_fn) String(memmove) Value(ILSOP_MEMMOVE) Set(3)
1991 Enum(ilsop_fn) String(memset) Value(ILSOP_MEMSET) Set(4)
1993 ; This is not part of any set either.
1995 ; Enum(ilsop_fn) String(all) Value(ILSOP_ALL)
1998 Common RejectNegative Alias(fcf-protection=,full)
2001 Common Joined RejectNegative Enum(cf_protection_level) EnumSet Var(flag_cf_protection) Init(CF_NONE)
2002 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
2003 instructions have valid targets.
2006 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
2009 Enum(cf_protection_level) String(full) Value(CF_FULL) Set(1)
2012 Enum(cf_protection_level) String(branch) Value(CF_BRANCH) Set(2)
2015 Enum(cf_protection_level) String(return) Value(CF_RETURN) Set(3)
2018 Enum(cf_protection_level) String(check) Value(CF_CHECK) Set(4)
2021 Enum(cf_protection_level) String(none) Value(CF_NONE) Set(1)
2023 finstrument-functions
2024 Common Var(flag_instrument_function_entry_exit,1)
2025 Instrument function entry and exit with profiling calls.
2027 finstrument-functions-once
2028 Common Var(flag_instrument_function_entry_exit,2)
2029 Instrument function entry and exit with profiling calls invoked once.
2031 finstrument-functions-exclude-function-list=
2032 Common RejectNegative Joined
2033 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
2035 finstrument-functions-exclude-file-list=
2036 Common RejectNegative Joined
2037 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
2040 Common Var(flag_ipa_cp) Optimization
2041 Perform interprocedural constant propagation.
2044 Common Var(flag_ipa_cp_clone) Optimization
2045 Perform cloning to make Interprocedural constant propagation stronger.
2049 Does nothing. Preserved for backward compatibility.
2052 Common Var(flag_ipa_bit_cp) Optimization
2053 Perform interprocedural bitwise constant propagation.
2056 Common Var(flag_ipa_modref) Optimization
2057 Perform interprocedural modref analysis.
2060 Common Var(flag_ipa_profile) Init(0) Optimization
2061 Perform interprocedural profile propagation.
2064 Common Var(flag_ipa_pta) Init(0) Optimization
2065 Perform interprocedural points-to analysis.
2068 Common Var(flag_ipa_pure_const) Init(0) Optimization
2069 Discover pure and const functions.
2072 Common Var(flag_ipa_icf) Optimization
2073 Perform Identical Code Folding for functions and read-only variables.
2076 Common Var(flag_ipa_icf_functions) Optimization
2077 Perform Identical Code Folding for functions.
2080 Common Var(flag_ipa_icf_variables) Optimization
2081 Perform Identical Code Folding for variables.
2084 Common Var(flag_ipa_reference) Init(0) Optimization
2085 Discover read-only and non addressable static variables.
2087 fipa-reference-addressable
2088 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
2089 Discover read-only, write-only and non-addressable static variables.
2091 fipa-stack-alignment
2092 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
2093 Reduce stack alignment on call sites if possible.
2097 Does nothing. Preserved for backward compatibility.
2101 Does nothing. Preserved for backward compatibility.
2104 Common Var(flag_ipa_vrp) Optimization
2105 Perform IPA Value Range Propagation.
2108 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
2109 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
2111 fipa-strict-aliasing
2112 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
2113 Assume strict aliasing rules apply across (uninlined) function boundaries.
2116 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
2119 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2122 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2125 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2126 -fira-region=[one|all|mixed] Set regions for IRA.
2129 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2132 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2135 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2138 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2141 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2142 Use IRA based register pressure calculation
2143 in RTL hoist optimizations.
2146 Common Var(flag_ira_loop_pressure) Optimization
2147 Use IRA based register pressure calculation
2148 in RTL loop optimizations.
2150 fira-share-save-slots
2151 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2152 Share slots for saving different hard registers.
2154 fira-share-spill-slots
2155 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2156 Share stack slots for spilled pseudo-registers.
2159 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2160 -fira-verbose=<number> Control IRA's level of diagnostic messages.
2163 Common Var(flag_ivopts) Init(1) Optimization
2164 Optimize induction variables on trees.
2167 Common Var(flag_jump_tables) Init(1) Optimization
2168 Use jump tables for sufficiently large switch statements.
2171 Common Var(flag_bit_tests) Init(1) Optimization
2172 Use bit tests for sufficiently large switch statements.
2174 fkeep-inline-functions
2175 Common Var(flag_keep_inline_functions)
2176 Generate code for functions even if they are fully inlined.
2178 fkeep-static-functions
2179 Common Var(flag_keep_static_functions)
2180 Generate code for static functions even if they are never called.
2183 Common Var(flag_keep_static_consts) Init(1)
2184 Emit static const variables even if they are not used.
2187 Common Var(flag_leading_underscore) Init(-1)
2188 Give external symbols a leading underscore.
2192 Does nothing. Preserved for backward compatibility.
2195 Common Var(flag_lra_remat) Optimization
2196 Do CFG-sensitive rematerialization in LRA.
2200 Enable link-time optimization.
2203 Common RejectNegative Joined Var(flag_lto)
2204 Link-time optimization with number of parallel jobs or jobserver.
2207 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2210 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2213 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2216 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2219 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2222 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2225 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2226 Specify the algorithm to partition symbols and vars at linktime.
2228 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2229 flto-compression-level=
2230 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2231 Use zlib/zstd compression level <number> for IL.
2233 flto-odr-type-merging
2235 Does nothing. Preserved for backward compatibility.
2238 Common Var(flag_lto_report) Init(0)
2239 Report various link-time optimization statistics.
2242 Common Var(flag_lto_report_wpa) Init(0)
2243 Report various link-time optimization statistics for WPA only.
2246 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2247 Set errno after built-in math functions.
2250 Common Joined RejectNegative UInteger Var(flag_max_errors)
2251 -fmax-errors=<number> Maximum number of errors to report.
2254 Common Var(mem_report)
2255 Report on permanent memory allocation.
2258 Common Var(mem_report_wpa)
2259 Report on permanent memory allocation in WPA only.
2261 ; This will attempt to merge constant section constants, if 1 only
2262 ; string constants and constants from constant pool, if 2 also constant
2264 fmerge-all-constants
2265 Common Var(flag_merge_constants,2) Init(1)
2266 Attempt to merge identical constants and constant variables.
2269 Common Var(flag_merge_constants,1)
2270 Attempt to merge identical constants across compilation units.
2272 fmerge-debug-strings
2273 Common Var(flag_merge_debug_strings) Init(1)
2274 Attempt to merge identical debug strings across compilation units.
2277 Common RejectNegative Joined UInteger
2278 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
2281 Common Var(flag_modulo_sched) Optimization
2282 Perform SMS based modulo scheduling before the first scheduling pass.
2284 fmodulo-sched-allow-regmoves
2285 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2286 Perform SMS based modulo scheduling with register moves allowed.
2288 fmove-loop-invariants
2289 Common Var(flag_move_loop_invariants) Optimization
2290 Move loop invariant computations out of loops.
2293 Common Var(flag_move_loop_stores) Optimization
2294 Move stores out of loops.
2298 Building block for specs-based multilib-aware TFLAGS.
2301 Common Var(flag_dce) Init(1) Optimization
2302 Use the RTL dead code elimination pass.
2305 Common Var(flag_dse) Init(0) Optimization
2306 Use the RTL dead store elimination pass.
2308 freschedule-modulo-scheduled-loops
2309 Common Var(flag_resched_modulo_sched) Optimization
2310 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2312 fnon-call-exceptions
2313 Common Var(flag_non_call_exceptions) Optimization
2314 Support synchronous non-call exceptions.
2317 Driver Joined MissingArgError(targets missing after %qs)
2320 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2321 -foffload-options=<targets>=<options> Specify options for the offloading targets.
2324 Common Joined RejectNegative Enum(offload_abi)
2325 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2328 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2331 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2334 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2337 Common Var(flag_omit_frame_pointer) Optimization
2338 When possible do not generate stack frames.
2340 fopenmp-target-simd-clone
2341 Common Alias(fopenmp-target-simd-clone=,any,none)
2343 fopenmp-target-simd-clone=
2344 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2345 Generate SIMD clones for functions with the OpenMP declare target directive.
2348 Name(target_simd_clone_device) Type(int)
2351 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2354 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2357 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2360 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2363 Common Var(flag_opt_info) Optimization
2364 Enable all optimization info dumps on stderr.
2367 Common Joined RejectNegative Var(common_deferred_options) Defer
2368 -fopt-info[-<type>=filename] Dump compiler optimization details.
2370 fsave-optimization-record
2371 Common Var(flag_save_optimization_record) Optimization
2372 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2374 foptimize-register-move
2376 Does nothing. Preserved for backward compatibility.
2378 foptimize-sibling-calls
2379 Common Var(flag_optimize_sibling_calls) Optimization
2380 Optimize sibling and tail recursive calls.
2383 Common Var(flag_partial_inlining) Optimization
2384 Perform partial inlining.
2387 Common Var(pre_ipa_mem_report)
2388 Report on memory allocation before interprocedural optimization.
2390 fpost-ipa-mem-report
2391 Common Var(post_ipa_mem_report)
2392 Report on memory allocation before interprocedural optimization.
2395 Common Var(flag_pack_struct) Optimization
2396 Pack structure members together without holes.
2399 Common RejectNegative Joined UInteger Optimization
2400 -fpack-struct=<number> Set initial maximum structure member alignment.
2403 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2404 Return small aggregates in memory, not registers.
2407 Common Var(flag_peel_loops) Optimization
2408 Perform loop peeling.
2411 Common Var(flag_no_peephole,0) Optimization
2412 Enable machine specific peephole optimizations.
2415 Common Var(flag_peephole2) Optimization
2416 Enable an RTL peephole pass before sched2.
2419 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2420 Generate position-independent code if possible (large mode).
2423 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2424 Generate position-independent code for executables if possible (large mode).
2427 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2428 Generate position-independent code if possible (small mode).
2431 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2432 Generate position-independent code for executables if possible (small mode).
2435 Common Var(flag_plt) Init(1) Optimization
2436 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2439 Common Joined RejectNegative Var(common_deferred_options) Defer
2440 Specify a plugin to load.
2443 Common Joined RejectNegative Var(common_deferred_options) Defer
2444 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2446 fpredictive-commoning
2447 Common Var(flag_predictive_commoning) Optimization
2448 Run predictive commoning optimization.
2450 fprefetch-loop-arrays
2451 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2452 Generate prefetch instructions, if available, for arrays in loops.
2455 Common Var(profile_flag)
2456 Enable basic program profiling code.
2459 Common Var(profile_abs_path_flag)
2460 Generate absolute source path names for gcov.
2463 Common Var(profile_arc_flag)
2464 Insert arc-based program profiling code.
2467 Common Joined RejectNegative Var(profile_data_prefix)
2468 Set the top-level directory for storing the profile data.
2469 The default is 'pwd'.
2472 Common Joined RejectNegative Var(profile_note_location)
2473 Select the name for storing the profile note file.
2476 Common Var(flag_profile_correction)
2477 Enable correction of flow inconsistent profile data input.
2480 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2481 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2483 fprofile-filter-files=
2484 Common Joined RejectNegative Var(flag_profile_filter_files)
2485 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2487 fprofile-exclude-files=
2488 Common Joined RejectNegative Var(flag_profile_exclude_files)
2489 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2492 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2495 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2498 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2501 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2503 fprofile-reproducible=
2504 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2505 -fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate.
2508 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2511 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2514 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2517 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2519 fprofile-prefix-path=
2520 Common Joined RejectNegative Var(profile_prefix_path)
2521 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2523 fprofile-prefix-map=
2524 Common Joined RejectNegative Var(common_deferred_options) Defer
2525 -fprofile-prefix-map=<old>=<new> Map one directory name to another in GCOV coverage result.
2529 Enable common options for generating profile info for profile feedback directed optimizations.
2532 Common Joined RejectNegative
2533 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2535 fprofile-info-section
2536 Common RejectNegative
2537 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2539 fprofile-info-section=
2540 Common Joined RejectNegative Var(profile_info_section)
2541 Register the profile information in the specified section instead of using a constructor/destructor.
2543 fprofile-partial-training
2544 Common Var(flag_profile_partial_training) Optimization
2545 Do not assume that functions never executed during the train run are cold.
2548 Common Var(flag_profile_use)
2549 Enable common options for performing profile feedback directed optimizations.
2552 Common Joined RejectNegative
2553 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2556 Common Var(flag_profile_values)
2557 Insert code to profile values of expressions.
2560 Common Var(profile_report)
2561 Report on consistency of profile.
2563 fprofile-reorder-functions
2564 Common Var(flag_profile_reorder_functions) Optimization
2565 Enable function reordering that improves code placement.
2567 fpatchable-function-entry=
2568 Common Var(flag_patchable_function_entry) Joined Optimization
2569 Insert NOP instructions at each function entry.
2572 Common Var(common_deferred_options) Defer
2575 Common Joined RejectNegative Var(common_deferred_options) Defer
2576 -frandom-seed=<string> Make compile reproducible using <string>.
2578 ; This switch causes the command line that was used to create an
2579 ; object file to be recorded into the object file. The exact format
2580 ; of this recording is target and binary file format dependent.
2581 ; It is related to the -fverbose-asm switch, but that switch only
2582 ; records information in the assembler output file as comments, so
2583 ; they never reach the object file.
2584 frecord-gcc-switches
2585 Common Var(flag_record_gcc_switches)
2586 Record gcc command line switches in the object file.
2589 Common Var(flag_pcc_struct_return,0) Optimization
2590 Return small aggregates in registers.
2594 Does nothing. Preserved for backward compatibility.
2597 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2598 Tell DSE that the storage for a C++ object is dead when the constructor
2599 starts and when the destructor finishes.
2602 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2605 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2608 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2609 -flive-patching=[inline-only-static|inline-clone] Control IPA
2610 optimizations to provide a safe compilation for live-patching. At the same
2611 time, provides multiple-level control on the enabled IPA optimizations.
2614 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2617 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2620 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2623 Common Var(flag_allocation_dce) Init(1) Optimization
2624 Tell DCE to remove unused C++ allocations.
2626 flive-range-shrinkage
2627 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2628 Relief of register pressure through live range shrinkage.
2631 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2632 Perform a register renaming optimization pass.
2635 Common Var(flag_schedule_fusion) Init(2) Optimization
2636 Perform a target dependent instruction fusion optimization pass.
2639 Common Var(flag_reorder_blocks) Optimization
2640 Reorder basic blocks to improve code placement.
2642 freorder-blocks-algorithm=
2643 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2644 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2647 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2650 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2653 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2655 freorder-blocks-and-partition
2656 Common Var(flag_reorder_blocks_and_partition) Optimization
2657 Reorder basic blocks and partition into hot and cold sections.
2660 Common Var(flag_reorder_functions) Optimization
2661 Reorder functions to improve code placement.
2663 frerun-cse-after-loop
2664 Common Var(flag_rerun_cse_after_loop) Optimization
2665 Add a common subexpression elimination pass after loop optimizations.
2669 Does nothing. Preserved for backward compatibility.
2672 Common Var(flag_rounding_math) Optimization SetByCombined
2673 Disable optimizations that assume default FP rounding behavior.
2676 Common Var(flag_schedule_interblock) Init(1) Optimization
2677 Enable scheduling across basic blocks.
2680 Common Var(flag_sched_pressure) Init(0) Optimization
2681 Enable register pressure sensitive insn scheduling.
2684 Common Var(flag_schedule_speculative) Init(1) Optimization
2685 Allow speculative motion of non-loads.
2688 Common Var(flag_schedule_speculative_load) Optimization
2689 Allow speculative motion of some loads.
2691 fsched-spec-load-dangerous
2692 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2693 Allow speculative motion of more loads.
2696 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2697 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2699 fsched2-use-superblocks
2700 Common Var(flag_sched2_use_superblocks) Optimization
2701 If scheduling post reload, do superblock scheduling.
2705 Does nothing. Preserved for backward compatibility.
2708 Common Var(flag_schedule_insns) Optimization
2709 Reschedule instructions before register allocation.
2712 Common Var(flag_schedule_insns_after_reload) Optimization
2713 Reschedule instructions after register allocation.
2715 ; This flag should be on when a target implements non-trivial
2716 ; scheduling hooks, maybe saving some information for its own sake.
2717 ; On IA64, for example, this is used for correct bundling.
2718 fselective-scheduling
2719 Common Var(flag_selective_scheduling) Optimization
2720 Schedule instructions using selective scheduling algorithm.
2722 fselective-scheduling2
2723 Common Var(flag_selective_scheduling2) Optimization
2724 Run selective scheduling after reload.
2727 Common Undocumented Joined Var(flag_self_test)
2728 Run self-tests, using the given path to locate test files.
2730 fsel-sched-pipelining
2731 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2732 Perform software pipelining of inner loops during selective scheduling.
2734 fsel-sched-pipelining-outer-loops
2735 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2736 Perform software pipelining of outer loops during selective scheduling.
2738 fsel-sched-reschedule-pipelined
2739 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2740 Reschedule pipelined regions without pipelining.
2742 fsemantic-interposition
2743 Common Var(flag_semantic_interposition) Init(1) Optimization
2744 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2746 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2747 ; of stalled insns into the ready list.
2748 fsched-stalled-insns
2749 Common Var(flag_sched_stalled_insns) Optimization UInteger
2750 Allow premature scheduling of queued insns.
2752 fsched-stalled-insns=
2753 Common RejectNegative Joined UInteger Optimization
2754 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2756 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2757 ; be examined for a dependency on a stalled insn that is candidate for
2758 ; premature removal from the queue of stalled insns into the ready list (has
2759 ; an effect only if the flag 'sched_stalled_insns' is set).
2760 fsched-stalled-insns-dep
2761 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2762 Set dependence distance checking in premature scheduling of queued insns.
2764 fsched-stalled-insns-dep=
2765 Common RejectNegative Joined UInteger Optimization
2766 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2768 fsched-group-heuristic
2769 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2770 Enable the group heuristic in the scheduler.
2772 fsched-critical-path-heuristic
2773 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2774 Enable the critical path heuristic in the scheduler.
2776 fsched-spec-insn-heuristic
2777 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2778 Enable the speculative instruction heuristic in the scheduler.
2780 fsched-rank-heuristic
2781 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2782 Enable the rank heuristic in the scheduler.
2784 fsched-last-insn-heuristic
2785 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2786 Enable the last instruction heuristic in the scheduler.
2788 fsched-dep-count-heuristic
2789 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2790 Enable the dependent count heuristic in the scheduler.
2793 Common Var(flag_section_anchors) Optimization
2794 Access data in the same section from shared anchor points.
2798 Does nothing. Preserved for backward compatibility.
2802 Does nothing. Preserved for backward compatibility.
2805 Common Var(flag_ree) Init(0) Optimization
2806 Turn on Redundant Extensions Elimination pass.
2809 Common Var(flag_show_column) Init(1)
2810 Show column numbers in diagnostics, when available. Default on.
2813 Common Var(flag_shrink_wrap) Optimization
2814 Emit function prologues only before parts of the function that need it,
2815 rather than at the top of the function.
2817 fshrink-wrap-separate
2818 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2819 Shrink-wrap parts of the prologue and epilogue separately.
2822 Common Var(flag_signaling_nans) Optimization SetByCombined
2823 Disable optimizations observable by IEEE signaling NaNs.
2826 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2827 Disable floating point optimizations that ignore the IEEE signedness of zero.
2829 fsingle-precision-constant
2830 Common Var(flag_single_precision_constant) Optimization
2831 Convert floating point constants to single precision constants.
2833 fsplit-ivs-in-unroller
2834 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2835 Split lifetimes of induction variables when loops are unrolled.
2838 Common Var(flag_split_stack) Init(-1)
2839 Generate discontiguous stack frames.
2842 Common Var(flag_split_wide_types) Optimization
2843 Split wide types into independent registers.
2845 fsplit-wide-types-early
2846 Common Var(flag_split_wide_types_early) Optimization
2847 Split wide types into independent registers earlier.
2850 Common Var(flag_ssa_backprop) Init(1) Optimization
2851 Enable backward propagation of use properties at the SSA level.
2854 Common Var(flag_ssa_phiopt) Optimization
2855 Optimize conditional patterns using SSA PHI nodes.
2858 Common Var(flag_stdarg_opt) Init(1) Optimization
2859 Optimize amount of stdarg registers saved to stack at start of function.
2861 fvariable-expansion-in-unroller
2862 Common Var(flag_variable_expansion_in_unroller) Optimization
2863 Apply variable expansion when loops are unrolled.
2866 Common RejectNegative Joined Optimization
2867 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2870 Common Alias(fstack-check=, specific, no)
2871 Insert stack checking code into the program. Same as -fstack-check=specific.
2873 fstack-clash-protection
2874 Common Var(flag_stack_clash_protection) Optimization
2875 Insert code to probe each page of stack space as it is allocated to protect
2876 from stack-clash style attacks.
2879 Common Var(common_deferred_options) Defer
2881 fstack-limit-register=
2882 Common RejectNegative Joined Var(common_deferred_options) Defer
2883 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2885 fstack-limit-symbol=
2886 Common RejectNegative Joined Var(common_deferred_options) Defer
2887 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2890 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2891 Use propolice as a stack protection method.
2893 fstack-protector-all
2894 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2895 Use a stack protection method for every function.
2897 fstack-protector-strong
2898 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2899 Use a smart stack protection method for certain functions.
2901 fstack-protector-explicit
2902 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2903 Use stack protection method only for functions with the stack_protect attribute.
2906 Common RejectNegative Var(flag_stack_usage)
2907 Output stack usage information on a per-function basis.
2911 Does nothing. Preserved for backward compatibility.
2913 ; Nonzero if we should do (language-dependent) alias analysis.
2914 ; Typically, this analysis will assume that expressions of certain
2915 ; types do not alias expressions of certain other types. Only used
2916 ; if alias analysis (in general) is enabled.
2918 Common Var(flag_strict_aliasing) Optimization
2919 Assume strict aliasing rules apply.
2923 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2926 Common RejectNegative Var(flag_strub, 0)
2927 Disable stack scrub entirely, disregarding strub attributes.
2930 Common RejectNegative Var(flag_strub, -4)
2931 Enable stack scrub as per attributes, with strict call checking.
2933 ; If any strub-enabling attribute is seen when the default or strict
2934 ; initializer values are in effect, flag_strub is bumped up by 2. The
2935 ; scrub mode gate function will then bump these initializer values to
2936 ; 0 if no strub-enabling attribute is seen. This minimizes the strub
2939 Common RejectNegative Var(flag_strub, -3) Init(-3)
2940 Restore default strub mode: as per attributes, with relaxed checking.
2943 Common RejectNegative Var(flag_strub, 3)
2944 Enable stack scrubbing for all viable functions.
2947 Common RejectNegative Var(flag_strub, 1)
2948 Enable at-calls stack scrubbing for all viable functions.
2951 Common RejectNegative Var(flag_strub, 2)
2952 Enable internal stack scrubbing for all viable functions.
2955 Common Var(flag_sync_libcalls) Init(1)
2956 Implement __atomic operations via libcalls to legacy __sync functions.
2959 Common Var(flag_syntax_only)
2960 Check for syntax errors, then stop.
2963 Common Var(flag_test_coverage)
2964 Create data files needed by \"gcov\".
2967 Common Var(flag_thread_jumps) Optimization
2968 Perform jump threading optimizations.
2971 Common Var(time_report)
2972 Report the time taken by each compiler pass.
2974 ftime-report-details
2975 Common Var(time_report_details)
2976 Record times taken by sub-phases separately.
2979 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2980 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2983 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2986 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2989 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2992 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2995 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2998 Common Var(flag_toplevel_reorder) Init(2) Optimization
2999 Reorder top level functions, variables, and asms.
3002 Common Var(flag_tracer) Optimization
3003 Perform superblock formation via tail duplication.
3006 Common Var(flag_trampolines) Init(HEAP_TRAMPOLINES_INIT)
3007 For targets that normally need trampolines for nested functions, always
3008 generate them instead of using descriptors.
3011 Common Joined RejectNegative Enum(trampoline_impl) Var(flag_trampoline_impl) Init(HEAP_TRAMPOLINES_INIT ? TRAMPOLINE_IMPL_HEAP : TRAMPOLINE_IMPL_STACK)
3012 Whether trampolines are generated in executable memory rather than
3016 Name(trampoline_impl) Type(enum trampoline_impl) UnknownError(unknown trampoline implementation %qs)
3019 Enum(trampoline_impl) String(stack) Value(TRAMPOLINE_IMPL_STACK)
3022 Enum(trampoline_impl) String(heap) Value(TRAMPOLINE_IMPL_HEAP)
3025 ; Zero means that floating-point math operations cannot generate a
3026 ; (user-visible) trap. This is the case, for example, in nonstop
3027 ; IEEE 754 arithmetic.
3029 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
3030 Assume floating-point operations can trap.
3033 Common Var(flag_trapv) Optimization
3034 Trap for signed overflow in addition, subtraction and multiplication.
3037 Common Var(flag_tree_ccp) Optimization
3038 Enable SSA-CCP optimization on trees.
3041 Common Var(flag_tree_bit_ccp) Optimization
3042 Enable SSA-BIT-CCP optimization on trees.
3046 Does nothing. Preserved for backward compatibility.
3049 Common Var(flag_tree_ch) Optimization
3050 Enable loop header copying on trees.
3052 ftree-coalesce-inlined-vars
3053 Common Ignore RejectNegative
3054 Does nothing. Preserved for backward compatibility.
3057 Common Var(flag_tree_coalesce_vars) Optimization
3058 Enable SSA coalescing of user variables.
3062 Does nothing. Preserved for backward compatibility.
3065 Common Var(flag_tree_copy_prop) Optimization
3066 Enable copy propagation on trees.
3068 ftree-store-copy-prop
3070 Does nothing. Preserved for backward compatibility.
3073 Common Var(flag_tree_cselim) Optimization
3074 Transform condition stores into unconditional ones.
3076 ftree-switch-conversion
3077 Common Var(flag_tree_switch_conversion) Optimization
3078 Perform conversions of switch initializations.
3081 Common Var(flag_tree_dce) Optimization
3082 Enable SSA dead code elimination optimization on trees.
3084 ftree-dominator-opts
3085 Common Var(flag_tree_dom) Optimization
3086 Enable dominator optimizations.
3089 Common Var(flag_tree_tail_merge) Optimization
3090 Enable tail merging on trees.
3093 Common Var(flag_tree_dse) Optimization
3094 Enable dead store elimination.
3097 Common Var(flag_tree_forwprop) Init(1) Optimization
3098 Enable forward propagation on trees.
3101 Common Var(flag_tree_fre) Optimization
3102 Enable Full Redundancy Elimination (FRE) on trees.
3105 Common Var(flag_optimize_strlen) Optimization
3106 Enable string length optimizations on trees.
3108 fisolate-erroneous-paths-dereference
3109 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
3110 Detect paths that trigger erroneous or undefined behavior due to
3111 dereferencing a null pointer. Isolate those paths from the main control
3112 flow and turn the statement with erroneous or undefined behavior into a trap.
3114 fisolate-erroneous-paths-attribute
3115 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
3116 Detect paths that trigger erroneous or undefined behavior due to a null value
3117 being used in a way forbidden by a returns_nonnull or nonnull
3118 attribute. Isolate those paths from the main control flow and turn the
3119 statement with erroneous or undefined behavior into a trap.
3121 ftree-loop-distribution
3122 Common Var(flag_tree_loop_distribution) Optimization
3123 Enable loop distribution on trees.
3125 ftree-loop-distribute-patterns
3126 Common Var(flag_tree_loop_distribute_patterns) Optimization
3127 Enable loop distribution for patterns transformed into a library call.
3130 Common Var(flag_tree_loop_im) Init(1) Optimization
3131 Enable loop invariant motion on trees.
3134 Common Alias(floop-nest-optimize)
3135 Enable loop nest transforms. Same as -floop-nest-optimize.
3138 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
3139 Create canonical induction variables in loops.
3142 Common Var(flag_tree_loop_optimize) Init(1) Optimization
3143 Enable loop optimizations on tree level.
3145 ftree-parallelize-loops=
3146 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
3147 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
3150 Common Var(flag_tree_phiprop) Init(1) Optimization
3151 Enable hoisting loads from conditional pointers.
3154 Common Var(flag_tree_pre) Optimization
3155 Enable SSA-PRE optimization on trees.
3158 Common Var(flag_tree_partial_pre) Optimization
3159 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
3162 Common Var(flag_tree_pta) Optimization
3163 Perform function-local points-to analysis on trees.
3166 Common Var(flag_tree_reassoc) Init(1) Optimization
3167 Enable reassociation on tree level.
3171 Does nothing. Preserved for backward compatibility.
3174 Common Var(flag_tree_sink) Optimization
3175 Enable SSA code sinking on trees.
3178 Common Var(flag_tree_slsr) Optimization
3179 Perform straight-line strength reduction.
3182 Common Var(flag_tree_sra) Optimization
3183 Perform scalar replacement of aggregates.
3186 Common Var(flag_tree_ter) Optimization
3187 Replace temporary expressions in the SSA->normal pass.
3190 Common Var(flag_tree_live_range_split) Optimization
3191 Perform live range splitting during the SSA->normal pass.
3194 Common Var(flag_tree_vrp) Init(0) Optimization
3195 Perform Value Range Propagation on trees.
3198 Common Var(flag_split_paths) Init(0) Optimization
3199 Split paths leading to loop backedges.
3201 funconstrained-commons
3202 Common Var(flag_unconstrained_commons) Optimization
3203 Assume common declarations may be overridden with ones with a larger
3207 Common Var(flag_unit_at_a_time) Init(1)
3208 Compile whole compilation unit at a time.
3211 Common Var(flag_unreachable_traps) Optimization
3212 Trap on __builtin_unreachable instead of using it for optimization.
3215 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3216 Perform loop unrolling when iteration count is known.
3219 Common Var(flag_unroll_all_loops) Optimization
3220 Perform loop unrolling for all loops.
3222 funroll-completely-grow-size
3223 Undocumented Var(flag_cunroll_grow_size) Optimization
3224 ; Internal undocumented flag, allow size growth during complete unrolling
3226 ; Nonzero means that loop optimizer may assume that the induction variables
3227 ; that control loops do not overflow and that the loops with nontrivial
3228 ; exit condition are not infinite
3229 funsafe-loop-optimizations
3231 Does nothing. Preserved for backward compatibility.
3234 Common Var(flag_associative_math) SetByCombined Optimization
3235 Allow optimization for floating-point arithmetic which may change the
3236 result of the operation due to rounding.
3239 Common Var(flag_reciprocal_math) SetByCombined Optimization
3240 Same as -fassociative-math for expressions which include division.
3242 ; Nonzero means that unsafe floating-point math optimizations are allowed
3243 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
3244 ; are allowed to assume that their arguments and results are "normal"
3245 ; (e.g., nonnegative for SQRT).
3246 funsafe-math-optimizations
3247 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3248 Allow math optimizations that may violate IEEE or ISO standards.
3251 Common Var(flag_unswitch_loops) Optimization
3252 Perform loop unswitching.
3255 Common Var(flag_split_loops) Optimization
3256 Perform loop splitting.
3258 fversion-loops-for-strides
3259 Common Var(flag_version_loops_for_strides) Optimization
3260 Version loops based on whether indices have a stride of one.
3263 Common Var(flag_unwind_tables) Optimization
3264 Just generate unwind tables for exception handling.
3267 Common Driver Negative(fuse-ld=gold)
3268 Use the bfd linker instead of the default linker.
3271 Common Driver Negative(fuse-ld=bfd)
3272 Use the gold linker instead of the default linker.
3275 Common Driver Negative(fuse-ld=lld)
3276 Use the lld LLVM linker instead of the default linker.
3279 Common Driver Negative(fuse-ld=mold)
3280 Use the Modern linker (MOLD) linker instead of the default linker.
3283 Common Undocumented Var(flag_use_linker_plugin)
3285 ; Positive if we should track variables, negative if we should run
3286 ; the var-tracking pass only to discard debug annotations, zero if
3287 ; we're not to run it.
3289 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3290 Perform variable tracking.
3292 ; Positive if we should track variables at assignments, negative if
3293 ; we should run the var-tracking pass only to discard debug
3295 fvar-tracking-assignments
3296 Common Var(flag_var_tracking_assignments) PerFunction
3297 Perform variable tracking by annotating assignments.
3299 ; Nonzero if we should toggle flag_var_tracking_assignments after
3300 ; processing options and computing its default. */
3301 fvar-tracking-assignments-toggle
3302 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3303 Toggle -fvar-tracking-assignments.
3305 ; Positive if we should track uninitialized variables, negative if
3306 ; we should run the var-tracking pass only to discard debug
3308 fvar-tracking-uninit
3309 Common Var(flag_var_tracking_uninit) PerFunction
3310 Perform variable tracking and also tag variables that are uninitialized.
3312 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3314 Common Var(flag_tree_vectorize) Optimization
3315 Enable vectorization on trees.
3317 ftree-vectorizer-verbose=
3318 Common Joined RejectNegative Ignore
3319 Does nothing. Preserved for backward compatibility.
3321 ftree-loop-vectorize
3322 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3323 Enable loop vectorization on trees.
3326 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3327 Enable basic block vectorization (SLP) on trees.
3330 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3331 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the cost model for vectorization.
3334 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3335 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the vectorization cost model for code marked with a simd directive.
3338 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3341 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3344 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3347 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3350 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3353 Common Alias(fvect-cost-model=,dynamic,unlimited)
3354 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
3356 ftree-vect-loop-version
3358 Does nothing. Preserved for backward compatibility.
3361 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3362 Enable copy propagation of scalar-evolution information.
3364 ftrivial-auto-var-init=
3365 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3366 -ftrivial-auto-var-init=[uninitialized|pattern|zero] Add initializations to automatic variables.
3369 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3372 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3375 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3378 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3380 ; -fverbose-asm causes extra commentary information to be produced in
3381 ; the generated assembly code (to make it more readable). This option
3382 ; is generally only of use to those who actually need to read the
3383 ; generated assembly code (perhaps while debugging the compiler itself).
3384 ; -fno-verbose-asm, the default, causes the extra information
3385 ; to not be added and is useful when comparing two assembler files.
3387 Common Var(flag_verbose_asm)
3388 Add extra commentary to assembler output.
3391 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3392 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
3395 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3398 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3401 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3404 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3407 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3410 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3411 Validate vtable pointers before using them.
3414 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3417 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3420 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3423 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3426 Common Var(flag_vtv_counts)
3427 Output vtable verification counters.
3430 Common Var(flag_vtv_debug)
3431 Output vtable verification pointer sets information.
3434 Common Var(flag_value_profile_transformations) Optimization
3435 Use expression value profiles in optimizations.
3438 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3439 Construct webs and split unrelated uses of single variable.
3441 ftree-builtin-call-dce
3442 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3443 Enable conditional dead code elimination for builtin calls.
3446 Common Var(flag_whole_program) Init(0)
3447 Perform whole program optimizations.
3450 Common Var(flag_wrapv_pointer) Optimization
3451 Assume pointer overflow wraps around.
3454 Common Var(flag_wrapv) Optimization
3455 Assume signed arithmetic overflow wraps around.
3457 fzero-initialized-in-bss
3458 Common Var(flag_zero_initialized_in_bss) Init(1)
3459 Put zero initialized data in the bss section.
3461 fzero-call-used-regs=
3462 Common RejectNegative Joined
3463 Clear call-used registers upon function return.
3466 Common Driver RejectNegative JoinedOrMissing
3467 Generate debug information in default format.
3470 Common Driver Var(dwarf2out_as_loc_support)
3471 Assume assembler support for (DWARF2+) .loc directives.
3474 Common Driver Var(dwarf2out_as_locview_support)
3475 Assume assembler support for view in (DWARF2+) .loc directives.
3478 Common Driver JoinedOrMissing
3479 Generate debug information in CodeView format.
3482 Common Driver WarnRemoved
3483 Does nothing. Preserved for backward compatibility.
3486 Common Driver WarnRemoved
3487 Does nothing. Preserved for backward compatibility.
3490 Common Driver WarnRemoved
3491 Does nothing. Preserved for backward compatibility.
3494 Common Driver WarnRemoved
3495 Does nothing. Preserved for backward compatibility.
3498 Common Driver Var(debug_column_info,1) Init(1)
3499 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3501 ; The CTF generation process feeds off DWARF dies. This option implicitly
3502 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3504 Common Driver RejectNegative JoinedOrMissing
3505 Generate CTF debug information at default level.
3508 Common Driver RejectNegative JoinedOrMissing
3509 Generate BTF debug information at default level.
3512 Common Driver JoinedOrMissing RejectNegative
3513 Generate debug information in default version of DWARF format.
3516 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT) RejectNegative
3517 Generate debug information in DWARF v2 (or later) format.
3520 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3521 Use 32-bit DWARF format when emitting DWARF debug information.
3524 Common Driver Var(dwarf_offset_size,8) RejectNegative
3525 Use 64-bit DWARF format when emitting DWARF debug information.
3528 Common Driver JoinedOrMissing RejectNegative
3529 Generate debug information in default extended format.
3532 Common Driver Var(debug_inline_points)
3533 Generate extended entry point information for inlined functions.
3535 ginternal-reset-location-views
3536 Common Driver Var(debug_internal_reset_location_views) Init(2)
3537 Compute locview reset points based on insn length estimates.
3540 RejectNegative Joined Undocumented
3541 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3544 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3545 Don't generate DWARF pubnames and pubtypes sections.
3548 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3549 Generate DWARF pubnames and pubtypes sections.
3552 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3553 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3555 grecord-gcc-switches
3556 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3557 Record gcc command line switches in DWARF DW_AT_producer.
3560 Common Driver Var(dwarf_split_debug_info) Init(0)
3561 Generate debug information in separate .dwo files.
3564 Common Driver WarnRemoved
3565 Does nothing. Preserved for backward compatibility.
3568 Common Driver WarnRemoved
3569 Does nothing. Preserved for backward compatibility.
3571 gstatement-frontiers
3572 Common Driver Var(debug_nonbind_markers_p) PerFunction
3573 Emit progressive recommended breakpoint locations.
3576 Common Driver Var(dwarf_strict) Init(0)
3577 Don't emit DWARF additions beyond selected version.
3580 Common Driver Var(flag_describe_dies) Init(0)
3581 Add description attributes to some DWARF DIEs that have no name attribute.
3584 Common Driver Var(flag_gtoggle)
3585 Toggle debug information generation.
3587 gvariable-location-views
3588 Common Driver Var(debug_variable_location_views, 1)
3589 Augment variable location lists with progressive views.
3591 gvariable-location-views=incompat5
3592 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3595 Common Driver JoinedOrMissing RejectNegative
3596 Generate debug information in VMS format.
3599 Common Driver WarnRemoved
3600 Does nothing. Preserved for backward compatibility.
3603 Common Driver JoinedOrMissing WarnRemoved
3604 Does nothing. Preserved for backward compatibility.
3607 Name(compressed_debug_sections) Type(int)
3609 ; Since -gz= is completely handled in specs, the values aren't used and we
3610 ; assign arbitrary constants.
3612 Enum(compressed_debug_sections) String(none) Value(0)
3615 Enum(compressed_debug_sections) String(zlib) Value(1)
3618 Enum(compressed_debug_sections) String(zstd) Value(2)
3621 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3625 Generate compressed debug sections.
3628 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3629 -gz=<format> Generate compressed debug sections in format <format>.
3632 Driver Joined Separate
3635 Common Joined Var(plugindir_string) Init(0)
3636 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3639 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3640 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3643 Driver Joined Separate
3648 no-canonical-prefixes
3667 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3668 -o <file> Place output into <file>.
3671 Common Var(profile_flag)
3672 Enable function profiling.
3675 Driver Var(pass_exit_codes)
3678 Common Alias(Wpedantic)
3681 Common Var(flag_pedantic_errors)
3682 Like -pedantic but issue them as errors.
3688 Driver Var(use_pipes)
3691 Driver JoinedOrMissing Var(print_file_name)
3693 print-libgcc-file-name
3696 print-multi-directory
3697 Driver Var(print_multi_directory)
3700 Driver Var(print_multi_lib)
3702 print-multi-os-directory
3703 Driver Var(print_multi_os_directory)
3706 Driver Var(print_multiarch)
3709 Driver JoinedOrMissing Var(print_prog_name)
3712 Driver Var(print_search_dirs)
3715 Driver Var(print_sysroot)
3717 print-sysroot-headers-suffix
3718 Driver Var(print_sysroot_headers_suffix)
3721 Common Var(quiet_flag) RejectDriver
3722 Do not display functions compiled or elapsed time.
3740 Driver Var(report_times)
3743 Driver JoinedOrMissing
3746 Driver Joined Separate
3750 ; C option, but driver must not handle as "-u ndef".
3753 Common Driver Var(verbose_flag)
3754 Enable verbose output.
3757 Common Var(version_flag) RejectDriver
3758 Display the compiler's version.
3761 Common Var(inhibit_warnings)
3765 Driver Separate Var(wrapper_string)
3768 Driver Joined Separate
3771 Driver RejectNegative Negative(static-pie)
3772 Create a shared library.
3778 Driver Separate Alias(specs=)
3791 ; Documented for Fortran, but always accepted by driver.
3795 ; Documented for Modula-2, but always accepted by driver.
3799 ; Documented for D, but always accepted by driver.
3803 ; Documented for Fortran, but always accepted by driver.
3810 ; Documented for Go, but always accepted by driver.
3831 Driver RejectNegative Negative(shared)
3832 Don't create a dynamically linked position independent executable.
3835 Driver RejectNegative Negative(no-pie)
3836 Create a dynamically linked position independent executable.
3839 Driver RejectNegative Negative(pie)
3840 Create a static position independent executable.
3843 Driver Joined Separate
3846 Common Var(flag_ipa_ra) Optimization
3847 Use caller save register across calls if possible.
3849 ; This comment is to ensure we retain the blank line above.