1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2024 Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
49 ; This variable is set to non-0 only by LTO front-end. 1 indicates that
50 ; the output produced will be used for incremental linking (thus weak symbols
51 ; can still be bound) and 2 indicates that the IL is going to be linked and
52 ; and output to LTO object file.
54 enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE
56 ; 0 means straightforward implementation of complex divide acceptable.
57 ; 1 means wide ranges of inputs must work for complex divide.
58 ; 2 means C99-like requirements for complex multiply and divide.
60 int flag_complex_method = 1
63 int flag_default_complex_method = 1
65 ; Language specific warning pass for unused results.
67 bool flag_warn_unused_result = false
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
75 int flag_generate_offload = 0
77 ; Nonzero means we should be saving declaration info into a .X file.
79 int flag_gen_aux_info = 0
81 ; Nonzero if we are compiling code for a shared library, zero for
86 ; These three are really VEC(char_p,heap) *.
89 void *flag_instrument_functions_exclude_functions
92 void *flag_instrument_functions_exclude_files
95 void *flag_ignored_attributes
97 ; Generic structs (e.g. templates not explicitly specialized)
98 ; may not have a compilation unit associated with them, and so
99 ; may need to be treated differently from ordinary structs.
101 ; Structs only handled by reference (indirectly), will also usually
102 ; not need as much debugging information.
105 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
108 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
110 ; True if we should exit after parsing options.
112 bool exit_after_options
114 ; Type(s) of debugging information we are producing (if any). See
115 ; flag-types.h for the definitions of the different possible types of
116 ; debugging information.
118 uint32_t write_symbols = NO_DEBUG
120 ; Level of debugging information we are producing. See flag-types.h
121 ; for the definitions of the different possible levels.
123 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
125 ; Level of CTF debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum ctf_debug_info_levels ctf_debug_info_level = CTFINFO_LEVEL_NONE
130 ; Original value of maximum field alignment in bytes, specified via
131 ; -fpack-struct=<value>.
133 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
135 ; Type of stack check.
137 enum stack_check_type flag_stack_check = NO_STACK_CHECK
139 ; True if stack usage information needs to be computed.
141 bool flag_stack_usage_info = false
143 ; -dA causes debug commentary information to be produced in
144 ; the generated assembly code (to make it more readable). This option
145 ; is generally only of use to those who actually need to read the
146 ; generated assembly code (perhaps while debugging the compiler itself).
147 ; Currently, this switch is only used by dwarf2out.cc; however, it is intended
148 ; to be a catchall for printing debug information in the assembler file.
152 ; Balance between GNAT encodings and standard DWARF to emit.
154 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
156 ; -dP causes the rtl to be emitted as a comment in assembly.
158 int flag_dump_rtl_in_asm
160 ; Whether -da was passed (used only in handle_common_deferred_options).
162 bool flag_dump_all_passed
164 ; Other flags saying which kinds of debugging dump have been requested.
167 int rtl_dump_and_exit
170 int flag_print_asm_name
172 ; Name of top-level original source file (what was input to cpp).
173 ; This comes from the #-command at the beginning of the actual input.
174 ; If there isn't any there, then this is the cc1 input file name.
176 const char *main_input_filename
178 ; Pointer to base name in main_input_filename, with directories and a
179 ; single final extension removed, and the length of this base
183 const char *main_input_basename
186 int main_input_baselength
188 ; The base name used for auxiliary output files.
189 ; dump_base_name minus dump_base_ext.
192 const char *aux_base_name
194 ; Which options have been printed by --help.
198 ; Which enums have been printed by --help. 0 = not printed, no
199 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
202 char *help_enum_printed
204 ; The number of columns for --help output.
206 unsigned int help_columns
208 ; Whether this options structure has been through finish_options
210 bool flag_opts_finished
212 ; What the sanitizer should instrument
214 unsigned int flag_sanitize
216 ; What sanitizers should recover from errors
218 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS | SANITIZE_KERNEL_HWADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
220 ; What sanitizers should use __builtin_trap () instead of runtime diagnostics
222 unsigned int flag_sanitize_trap
224 ; Flag whether a prefix has been added to dump_base_name
226 bool dump_base_name_prefixed = false
228 ; What subset of registers should be zeroed on function return
230 unsigned int flag_zero_call_used_regs
242 Common Driver Joined Undocumented
243 Provide bash completion for options starting with provided string.
246 Driver Alias(coverage)
252 Common Separate Alias(d)
255 Common Joined Alias(d)
258 Driver Common Separate Alias(dumpbase)
261 Driver Common Separate Alias(dumpbase-ext)
264 Driver Common Separate Alias(dumpdir)
267 Driver Separate Alias(e)
270 Driver Joined Alias(e)
273 Common Warning Alias(Wextra)
276 Driver Separate Alias(Xassembler)
279 Driver JoinedOrMissing Alias(Xassembler)
282 Driver Separate Alias(Xlinker)
285 Driver JoinedOrMissing Alias(Xlinker)
288 Driver Separate Alias(u)
291 Driver Joined Alias(u)
294 Common Driver Var(help_flag)
295 Display this information.
299 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
302 Driver Separate Alias(x)
305 Driver Joined Alias(x)
308 Driver Separate Alias(L)
311 Driver Joined Alias(L)
313 -no-canonical-prefixes
314 Driver Alias(no-canonical-prefixes)
316 -no-standard-libraries
317 Driver Alias(nostdlib)
320 Driver Var(no_sysroot_suffix)
329 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
332 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
335 Driver Alias(pass-exit-codes)
338 Common Alias(Wpedantic)
341 Common Alias(pedantic-errors)
347 Driver Alias(static-pie)
353 Driver Separate Alias(B)
356 Driver JoinedOrMissing Alias(B)
362 Driver Separate Alias(print-file-name=)
365 Driver JoinedOrMissing Alias(print-file-name=)
367 -print-libgcc-file-name
368 Driver Alias(print-libgcc-file-name)
370 -print-multi-directory
371 Driver Alias(print-multi-directory)
374 Driver Alias(print-multi-lib)
376 -print-multi-os-directory
377 Driver Alias(print-multi-os-directory)
380 Driver Alias(print-multiarch)
383 Driver Separate Alias(print-prog-name=)
386 Driver JoinedOrMissing Alias(print-prog-name=)
389 Driver Alias(print-search-dirs)
392 Driver Alias(print-sysroot)
394 -print-sysroot-headers-suffix
395 Driver Alias(print-sysroot-headers-suffix)
401 Driver Alias(save-temps)
407 Driver Separate Alias(specs=)
410 Driver Joined Alias(specs=)
416 Driver Alias(symbolic)
420 Display target specific command line options (including assembler and linker options).
425 ;; Truncate the file specified after linking.
426 ;; This option is used by lto-wrapper to reduce the peak disk-usage when
427 ;; linking with many .LTRANS units.
429 Driver Separate Undocumented MissingArgError(missing filename after %qs)
434 ;; The driver used to convert options such as --help into forms such
435 ;; as -fhelp; the following four entries are for compatibility with
436 ;; any direct uses of those (undocumented) -f forms
438 Common Driver Alias(-help)
441 Common Driver Joined Alias(-help=)
444 Common Driver Alias(-target-help)
447 Common Driver Alias(-version)
450 Driver Separate Alias(-sysroot=)
453 Driver JoinedOrMissing
459 Driver Joined Separate
465 Driver Joined Separate
471 Common JoinedOrMissing Optimization
472 -O<number> Set optimization level to <number>.
476 Optimize for space rather than speed.
480 Optimize for speed disregarding exact standards compliance.
484 Optimize for debugging experience rather than speed or size.
488 Optimize for space aggressively rather than speed.
500 Driver Joined Separate
506 Driver Joined Separate
527 Common RejectNegative Warning Alias(Wextra)
528 This switch is deprecated; use -Wextra instead.
531 Driver JoinedOrMissing RejectNegative
534 Driver JoinedOrMissing RejectNegative
537 Driver JoinedOrMissing RejectNegative
540 Common Var(warn_aggregate_return) Warning
541 Warn about returning structures, unions or arrays.
543 Waggressive-loop-optimizations
544 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
545 Warn if a loop with constant number of iterations triggers undefined behavior.
548 Common Alias(Warray-bounds=, 1, 0) Warning
551 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
552 Warn if an array is accessed out of bounds.
555 Common Var(warn_use_after_free) Warning
556 Warn for uses of pointers to deallocated storage.
559 Common Joined RejectNegative UInteger Var(warn_use_after_free) Warning IntegerRange(0, 3)
560 Warn for uses of pointers to deallocated storage.
563 Common Var(warn_attributes) Init(1) Warning
564 Warn about inappropriate attribute usage.
568 Do not warn about specified attributes.
571 Common Alias(Wattribute_alias=, 1, 0) Warning
572 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
575 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
576 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
579 Common Var(warn_cannot_profile) Init(1) Warning
580 Warn when profiling instrumentation was requested, but could not be applied to
584 Common Var(warn_cast_align) Warning
585 Warn about pointer casts which increase alignment.
588 Common Var(warn_cast_align,2) Warning
589 Warn about pointer casts which increase alignment.
592 Common Var(warn_complain_wrong_lang) Init(1) Warning
593 Complain when a command-line option is valid, but not applicable to the current front end.
596 Common Var(warn_cpp) Init(1) Warning
597 Warn when a #warning directive is encountered.
600 Common Var(warn_attribute_warning) Init(1) Warning
601 Warn about uses of __attribute__((warning)) declarations.
604 Common Var(warn_deprecated) Init(1) Warning
605 Warn if a deprecated compiler feature, class, method, or field is used.
607 Wdeprecated-declarations
608 Common Var(warn_deprecated_decl) Init(1) Warning
609 Warn about uses of __attribute__((deprecated)) declarations.
611 Wdisabled-optimization
612 Common Var(warn_disabled_optimization) Warning
613 Warn when an optimization pass is disabled.
616 Common Var(warnings_are_errors)
617 Treat all warnings as errors.
621 Treat specified warning as error.
624 Common Var(extra_warnings) Warning
625 Print extra (possibly unwanted) warnings.
628 Common Var(flag_fatal_errors)
629 Exit on the first error occurred.
632 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
633 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
635 Wno-frame-larger-than
636 Common Alias(Wframe-larger-than=,18446744073709551615EiB,none) Warning
637 Disable -Wframe-larger-than= warning. Equivalent to -Wframe-larger-than=<SIZE_MAX> or larger.
640 Common Var(warn_free_nonheap_object) Init(1) Warning
641 Warn when attempting to free a non-heap object.
644 Common Var(warn_hardened) Init(1) Warning
645 Warn when -fhardened did not enable an option from its set.
648 Common Ignore Warning
649 Does nothing. Preserved for backward compatibility.
651 Wimplicit-fallthrough
652 Common Alias(Wimplicit-fallthrough=,3,0) Warning
654 Wimplicit-fallthrough=
655 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
656 Warn when a switch case falls through.
659 Var(warn_infinite_recursion) Warning
660 Warn for infinitely recursive calls.
663 Common Var(warn_inline) Warning Optimization
664 Warn when an inlined function cannot be inlined.
666 Winvalid-memory-model
667 Common Var(warn_invalid_memory_model) Init(1) Warning
668 Warn when an atomic memory model parameter is known to be outside the valid range.
671 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
674 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
675 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
678 Common Alias(Wlarger-than=,18446744073709551615EiB,none) Warning
679 Disable -Wlarger-than= warning. Equivalent to -Wlarger-than=<SIZE_MAX> or larger.
682 Var(warn_nonnull_compare) Warning
683 Warn if comparing pointer parameter with nonnull attribute with NULL.
686 Common Var(warn_null_dereference) Warning
687 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
689 Wunsafe-loop-optimizations
690 Common Ignore Warning
691 Does nothing. Preserved for backward compatibility.
694 Common Warning Alias(Wsuggest-attribute=noreturn)
697 Common Var(warn_odr_violations) Init(1) Warning
698 Warn about some C++ One Definition Rule violations during link time optimization.
701 Common Var(warn_overflow) Init(1) Warning
702 Warn about overflow in arithmetic expressions.
705 Common Var(warn_lto_type_mismatch) Init(1) Warning
706 During link time optimization warn about mismatched types of global declarations.
709 Common Var(warn_packed) Warning
710 Warn when the packed attribute has no effect on struct layout.
713 Common Var(warn_padded) Warning
714 Warn when padding is required to align structure members.
717 Common Var(pedantic) Init(0) Warning
718 Issue warnings needed for strict compliance to the standard.
721 Common Var(warn_return_local_addr) Init(1) Warning
722 Warn about returning a pointer/reference to a local or temporary variable.
725 Common Var(warn_shadow) Warning
726 Warn when one variable shadows another. Same as -Wshadow=global.
729 Common Warning Alias(Wshadow)
730 Warn when one variable shadows another (globally).
733 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
734 Warn when one local variable shadows another local variable or parameter.
737 Common Warning Undocumented Alias(Wshadow=local)
739 Wshadow=compatible-local
740 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
741 Warn when one local variable shadows another local variable or parameter of compatible type.
743 Wshadow-compatible-local
744 Common Warning Undocumented Alias(Wshadow=compatible-local)
747 Common Var(warn_stack_protect) Warning
748 Warn when not issuing stack smashing protection for some reason.
751 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
752 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
755 Common Alias(Wstack-usage=,18446744073709551615EiB,none) Warning
756 Disable Wstack-usage= warning. Equivalent to Wstack-usage=<SIZE_MAX> or larger.
760 Warn about code which might break strict aliasing rules.
763 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
764 Warn about code which might break strict aliasing rules.
768 Warn about optimizations that assume that signed overflow is undefined.
771 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
772 Warn about optimizations that assume that signed overflow is undefined.
774 Wsuggest-attribute=cold
775 Common Var(warn_suggest_attribute_cold) Warning
776 Warn about functions which might be candidates for __attribute__((cold)).
778 Wsuggest-attribute=const
779 Common Var(warn_suggest_attribute_const) Warning
780 Warn about functions which might be candidates for __attribute__((const)).
782 Wsuggest-attribute=pure
783 Common Var(warn_suggest_attribute_pure) Warning
784 Warn about functions which might be candidates for __attribute__((pure)).
786 Wsuggest-attribute=noreturn
787 Common Var(warn_suggest_attribute_noreturn) Warning
788 Warn about functions which might be candidates for __attribute__((noreturn)).
790 Wsuggest-attribute=malloc
791 Common Var(warn_suggest_attribute_malloc) Warning
792 Warn about functions which might be candidates for __attribute__((malloc)).
794 Wsuggest-attribute=returns_nonnull
795 Common Var(warn_suggest_attribute_returns_nonnull) Warning
796 Warn about functions which might be candidates for __attribute__((returns_nonnull)).
799 Common Var(warn_suggest_final_types) Warning
800 Warn about C++ polymorphic types where adding final keyword would improve code quality.
802 Wsuggest-final-methods
803 Common Var(warn_suggest_final_methods) Warning
804 Warn about C++ virtual methods where adding final keyword would improve code quality.
807 Common Var(warn_switch_unreachable) Warning Init(1)
808 Warn about statements between switch's controlling expression and the first
812 Common Var(warn_system_headers) Warning
813 Do not suppress warnings from system headers.
816 Common Var(warn_trampolines) Warning
817 Warn whenever a trampoline is generated.
819 Wtrivial-auto-var-init
820 Common Var(warn_trivial_auto_var_init) Warning Init(0)
821 Warn about cases where -ftrivial-auto-var-init cannot initialize an auto variable.
824 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
825 Warn if a comparison is always true or always false due to the limited range of the data type.
828 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
829 Warn about uninitialized automatic variables.
832 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
833 Warn about maybe uninitialized automatic variables.
836 Common Ignore Warning
837 Does nothing. Preserved for backward compatibility.
840 Common Var(warn_unused) Init(0) Warning
841 Enable all -Wunused- warnings.
843 Wunused-but-set-parameter
844 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
845 Warn when a function parameter is only set, otherwise unused.
847 Wunused-but-set-variable
848 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
849 Warn when a variable is only set, otherwise unused.
852 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
853 Warn when a function is unused.
856 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
857 Warn when a label is unused.
860 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
861 Warn when a function parameter is unused.
864 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
865 Warn when an expression value is unused.
868 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
869 Warn when a variable is unused.
872 Common Var(warn_coverage_mismatch) Init(1) Warning
873 Warn in case profiles in -fprofile-use do not match.
875 Wcoverage-invalid-line-number
876 Common Var(warn_coverage_invalid_linenum) Init(1) Warning
877 Warn in case a function ends earlier than it begins due to an invalid linenum macros.
879 Wcoverage-too-many-conditions
880 Common Var(warn_too_many_conditions) Init(1) Warning
881 Warn when a conditional has too many terms and condition coverage profiling
882 gives up instrumenting the expression.
885 Common Var(warn_missing_profile) Init(1) Warning
886 Warn in case profiles in -fprofile-use do not exist.
888 Wvector-operation-performance
889 Common Var(warn_vector_operation_performance) Warning
890 Warn when a vector operation is compiled outside the SIMD.
893 Common Var(warn_tsan) Init(1) Warning
894 Warn about unsupported features in ThreadSanitizer.
909 Common Separate Var(aux_info_file_name)
910 -aux-info <file> Emit declaration information into <file>.
913 Common Joined Alias(aux-info)
923 -d<letters> Enable dumps from specific passes of the compiler.
926 Driver Common Separate Var(dump_base_name)
927 -dumpbase <file> Set the file basename to be used for dumps.
930 Driver Common Separate Var(dump_base_ext)
931 -dumpbase-ext .<ext> Drop a trailing .<ext> from the dump basename to name auxiliary output files.
934 Driver Common Separate Var(dump_dir_name)
935 -dumpdir <dir> Set the directory name to be used for dumps.
950 Driver Joined Separate
952 ; This option has historically been passed down to the linker by an
953 ; accident of a %{e*} spec, so ensure it continues to be passed down
954 ; as a single option. The supported option for this purpose is
955 ; -rdynamic. See PR 47390.
959 ; The version of the C++ ABI in use. The following values are allowed:
961 ; 0: The version of the ABI believed most conformant with the C++ ABI
962 ; specification. This ABI may change as bugs are discovered and fixed.
963 ; Therefore, 0 will not necessarily indicate the same ABI in different
966 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
968 ; 2: The version of the ABI first used in G++ 3.4, and the default
971 ; 3: The version of the ABI that fixes the missing underscore
972 ; in template non-type arguments of pointer type.
974 ; 4: The version of the ABI that introduces unambiguous mangling of
975 ; vector types. First selectable in G++ 4.5.
977 ; 5: The version of the ABI that ignores attribute const/noreturn
978 ; in function pointer mangling, and corrects mangling of decltype and
979 ; function parameters used in other parameters and the return type.
980 ; First selectable in G++ 4.6.
982 ; 6: The version of the ABI that doesn't promote scoped enums to int and
983 ; changes the mangling of template argument packs, const/static_cast,
984 ; prefix ++ and --, and a class scope function used as a template
986 ; First selectable in G++ 4.7.
988 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
989 ; corrects the mangling of lambdas in default argument scope.
990 ; First selectable in G++ 4.8.
992 ; 8: The version of the ABI that corrects the substitution behavior of
993 ; function types with function-cv-qualifiers.
994 ; First selectable in G++ 4.9 and default in G++ 5.
996 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
997 ; First selectable and default in G++ 5.2.
999 ; 10: The version of the ABI that mangles attributes that affect type
1000 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
1001 ; Default in G++ 6 (set in c_common_post_options).
1003 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
1004 ; and introduces new inheriting constructor handling.
1007 ; 12: Corrects the calling convention for classes with only deleted copy/move
1008 ; constructors and changes passing/returning of empty records.
1009 ; Default in G++ 8.1.
1011 ; 13: Fixes the accidental change in 12 to the calling convention for classes
1012 ; with deleted copy constructor and trivial move constructor.
1013 ; Default in G++ 8.2.
1015 ; 14: Corrects the mangling of nullptr expression.
1016 ; Default in G++ 10.
1018 ; 15: Corrects G++ 10 ABI tag regression [PR98481].
1019 ; Available, but not default, in G++ 10.3.
1021 ; 16: Changes the mangling of __alignof__ to be distinct from that of alignof.
1022 ; Adds missing 'on' in mangling of operator names in some cases.
1023 ; Default in G++ 11.
1025 ; 17: Fixes layout of classes that inherit from aggregate classes with default
1026 ; member initializers in C++14 and up.
1027 ; Default in G++ 12.
1029 ; 18: Corrects errors in mangling of lambdas with additional context.
1030 ; Default in G++ 13.
1032 ; 19: Emits ABI tags if needed in structured binding mangled names.
1033 ; Ignores cv-quals on [[no_unique_object]] members.
1034 ; Mangles constraints on function templates.
1035 ; Default in G++ 14.
1037 ; Additional positive integers will be assigned as new versions of
1038 ; the ABI become the default version of the ABI.
1040 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1041 The version of the C++ ABI in use.
1043 faggressive-loop-optimizations
1044 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1045 Aggressively optimize loops using language constraints.
1048 Common Var(flag_align_functions) Optimization
1049 Align the start of functions.
1052 Common RejectNegative Joined Var(str_align_functions) Optimization
1055 Common Var(flag_align_jumps) Optimization
1056 Align labels which are only reached by jumping.
1059 Common RejectNegative Joined Var(str_align_jumps) Optimization
1062 Common Var(flag_align_labels) Optimization
1066 Common RejectNegative Joined Var(str_align_labels) Optimization
1069 Common Var(flag_align_loops) Optimization
1070 Align the start of loops.
1073 Common RejectNegative Joined Var(str_align_loops) Optimization
1075 fallow-store-data-races
1076 Common Var(flag_store_data_races) Optimization
1077 Allow the compiler to introduce new data races on stores.
1080 Common Var(flag_analyzer)
1081 Enable static analysis pass.
1085 Does nothing. Preserved for backward compatibility.
1089 Does nothing. Preserved for backward compatibility.
1091 fargument-noalias-global
1093 Does nothing. Preserved for backward compatibility.
1095 fargument-noalias-anything
1097 Does nothing. Preserved for backward compatibility.
1100 Common Driver Joined
1101 Select what to sanitize.
1104 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1105 Select type of coverage sanitization.
1108 Name(sanitize_coverage) Type(int)
1111 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1114 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1116 fasan-shadow-offset=
1117 Common Joined RejectNegative Var(common_deferred_options) Defer
1118 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1121 Common Joined RejectNegative Var(common_deferred_options) Defer
1122 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1123 in user-defined sections.
1127 After diagnosing undefined behavior attempt to continue execution.
1131 This switch is deprecated; use -fsanitize-recover= instead.
1134 Common Driver Joined
1135 Use traps instead of diagnostics of undefined behavior sanitizers.
1140 fsanitize-address-use-after-scope
1141 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1143 fsanitize-undefined-trap-on-error
1144 Common Driver Alias(fsanitize-trap)
1145 This switch is deprecated; use -fsanitize-trap= instead.
1147 fasynchronous-unwind-tables
1148 Common Var(flag_asynchronous_unwind_tables) Optimization
1149 Generate unwind tables that are exact at each instruction boundary.
1152 Common Var(flag_auto_inc_dec) Init(1) Optimization
1153 Generate auto-inc/dec instructions.
1156 Common Var(flag_auto_profile)
1157 Use sample profile information for call graph node weights. The default
1158 profile file is fbdata.afdo in 'pwd'.
1161 Common Joined RejectNegative Var(auto_profile_file)
1162 Use sample profile information for call graph node weights. The profile
1163 file is specified in the argument.
1165 ; -fcheck-bounds causes gcc to generate array bounds checks.
1166 ; For C, C++ and ObjC: defaults off.
1167 ; For Java: defaults to on.
1168 ; For Fortran: defaults to off.
1170 Common Var(flag_bounds_check)
1171 Generate code to check bounds before indexing arrays.
1174 Common Var(flag_branch_on_count_reg) Optimization
1175 Replace add, compare, branch with branch on count register.
1177 fbranch-probabilities
1178 Common Var(flag_branch_probabilities) Optimization
1179 Use profiling information for branch probabilities.
1181 fbranch-target-load-optimize
1183 Does nothing. Preserved for backward compatibility.
1185 fbranch-target-load-optimize2
1187 Does nothing. Preserved for backward compatibility.
1191 Does nothing. Preserved for backward compatibility.
1194 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1195 Output callgraph information on a per-file basis.
1198 Common RejectNegative Joined
1199 Output callgraph information on a per-file basis with decorations.
1202 Common Joined RejectNegative Var(common_deferred_options) Defer
1203 -fcall-saved-<register> Mark <register> as being preserved across functions.
1206 Common Joined RejectNegative Var(common_deferred_options) Defer
1207 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1209 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1210 ; be saved across function calls, if that produces overall better code.
1211 ; Optional now, so people can test it.
1213 Common Var(flag_caller_saves) Optimization
1214 Save registers around function calls.
1218 This switch is deprecated; do not use.
1221 Common Var(flag_check_new)
1222 Check the return value of new in C++.
1225 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1226 Perform internal consistency checkings.
1229 Common Joined RejectNegative UInteger Var(flag_checking)
1230 Perform internal consistency checkings.
1233 Common Var(common_deferred_options) Defer
1234 For -f*-prefix-map= options compare canonicalized pathnames rather than just strings.
1237 Common Var(flag_code_hoisting) Optimization
1238 Enable code hoisting.
1240 fcombine-stack-adjustments
1241 Common Var(flag_combine_stack_adjustments) Optimization
1242 Looks for opportunities to reduce stack adjustments and stack references.
1245 Common Var(flag_no_common,0) Init(1)
1246 Put uninitialized globals in the common section.
1250 ; Converted by the driver to -fcompare-debug= options.
1253 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1254 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1256 fcompare-debug-second
1257 Common Driver RejectNegative Var(flag_compare_debug)
1258 Run only the second compilation of -fcompare-debug.
1261 Common Var(flag_compare_elim_after_reload) Optimization
1262 Perform comparison elimination after register allocation has finished.
1265 Common Var(flag_conserve_stack) Optimization
1266 Do not perform optimizations increasing noticeably stack usage.
1269 Common Var(flag_cprop_registers) Optimization
1270 Perform a register copy-propagation optimization pass.
1273 Common Var(flag_fold_mem_offsets) Init(1) Optimization
1274 Fold instructions calculating memory offsets to the memory access instruction if possible.
1277 Common Var(flag_crossjumping) Optimization
1278 Perform cross-jumping optimization.
1281 Common Var(flag_cse_follow_jumps) Optimization
1282 When running CSE, follow jumps to their targets.
1286 Does nothing. Preserved for backward compatibility.
1289 Common Var(flag_cx_limited_range) Optimization SetByCombined
1290 Omit range reduction step when performing complex division.
1293 Common Var(flag_cx_fortran_rules) Optimization
1294 Complex multiplication and division follow Fortran rules.
1297 Common Var(flag_data_sections)
1298 Place data items into their own section.
1301 Common Var(flag_dbg_cnt_list)
1302 List all available debugging counters with their limits and counts.
1305 Common RejectNegative Joined Var(common_deferred_options) Defer
1306 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1309 Common Joined RejectNegative Var(common_deferred_options) Defer
1310 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1313 Common Joined RejectNegative Var(common_deferred_options) Defer
1314 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1316 fdebug-types-section
1317 Common Var(flag_debug_types_section) Init(0)
1318 Output .debug_types section when using DWARF v4 debuginfo.
1320 ; Nonzero for -fdefer-pop: don't pop args after each function call
1321 ; instead save them up to pop many calls' args with one insns.
1323 Common Var(flag_defer_pop) Optimization
1324 Defer popping functions args from stack until later.
1327 Common Var(flag_delayed_branch) Optimization
1328 Attempt to fill delay slots of branch instructions.
1330 fdelete-dead-exceptions
1331 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1332 Delete dead instructions that may throw exceptions.
1334 fdelete-null-pointer-checks
1335 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1336 Delete useless null pointer checks.
1338 fdevirtualize-at-ltrans
1339 Common Var(flag_ltrans_devirtualize)
1340 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1342 fdevirtualize-speculatively
1343 Common Var(flag_devirtualize_speculatively) Optimization
1344 Perform speculative devirtualization.
1347 Common Var(flag_devirtualize) Optimization
1348 Try to convert virtual calls to direct ones.
1350 fdiagnostics-show-location=
1351 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1352 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1354 ; Required for these enum values.
1359 Name(diagnostic_prefixing_rule) Type(int)
1362 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1365 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1367 fdiagnostics-show-caret
1368 Common Var(flag_diagnostics_show_caret) Init(1)
1369 Show the source line with a caret indicating the column.
1371 fdiagnostics-show-labels
1372 Common Var(flag_diagnostics_show_labels) Init(1)
1373 Show labels annotating ranges of source code when showing source.
1375 fdiagnostics-show-line-numbers
1376 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1377 Show line numbers in the left margin when showing source.
1380 Common Alias(fdiagnostics-color=,always,never)
1384 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1385 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1387 ; Required for these enum values.
1392 Name(diagnostic_color_rule) Type(int)
1395 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1398 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1401 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1403 fdiagnostics-json-formatting
1404 Common Var(flag_diagnostics_json_formatting) Init(1)
1405 Enable formatting of JSON output.
1408 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1409 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1411 ; Required for these enum values.
1416 Name(diagnostic_url_rule) Type(int)
1419 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1422 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1425 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1427 fdiagnostics-column-unit=
1428 Common Joined RejectNegative Enum(diagnostics_column_unit)
1429 -fdiagnostics-column-unit=[display|byte] Select whether column numbers are output as display columns (default) or raw bytes.
1431 fdiagnostics-column-origin=
1432 Common Joined RejectNegative UInteger
1433 -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.
1435 fdiagnostics-format=
1436 Common Joined RejectNegative Enum(diagnostics_output_format)
1437 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file] Select output format.
1439 fdiagnostics-escape-format=
1440 Common Joined RejectNegative Enum(diagnostics_escape_format)
1441 -fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1443 ; Required for these enum values.
1448 Name(diagnostics_column_unit) Type(int)
1451 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1454 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1457 Name(diagnostics_escape_format) Type(int)
1460 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1463 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1466 Name(diagnostics_output_format) Type(int)
1469 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1472 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1475 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1478 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1481 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1484 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1486 fdiagnostics-parseable-fixits
1487 Common Var(flag_diagnostics_parseable_fixits)
1488 Print fix-it hints in machine-readable form.
1490 fdiagnostics-generate-patch
1491 Common Var(flag_diagnostics_generate_patch)
1492 Print fix-it hints to stderr in unified diff format.
1494 fdiagnostics-show-option
1495 Common Var(flag_diagnostics_show_option) Init(1)
1496 Amend appropriate diagnostic messages with the command line option that controls them.
1498 fdiagnostics-show-cwe
1499 Common Var(flag_diagnostics_show_cwe) Init(1)
1500 Print CWE identifiers for diagnostic messages, where available.
1502 fdiagnostics-show-rules
1503 Common Var(flag_diagnostics_show_rules) Init(1)
1504 Print any rules associated with diagnostic messages.
1506 fdiagnostics-path-format=
1507 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1508 Specify how to print any control-flow path associated with a diagnostic.
1510 fdiagnostics-plain-output
1511 Driver Common RejectNegative
1512 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1515 Common Joined RejectNegative UInteger
1516 -ftabstop=<number> Distance between tab stops for column reporting.
1519 Name(diagnostic_path_format) Type(int)
1522 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1525 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1528 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1530 fdiagnostics-show-path-depths
1531 Common Var(flag_diagnostics_show_path_depths) Init(0)
1532 Show stack depths of events in paths.
1534 fdiagnostics-text-art-charset=
1535 Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1536 -fdiagnostics-text-art-charset=[none|ascii|unicode|emoji] Determine which characters to use in text arg diagrams.
1539 Name(diagnostic_text_art_charset) Type(int)
1542 Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
1545 Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
1548 Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
1551 Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
1553 fdiagnostics-minimum-margin-width=
1554 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1555 Set minimum width of left margin of source code when showing source.
1558 Common Joined RejectNegative Var(common_deferred_options) Defer
1559 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 Disable an optimization pass.
1562 Common Joined RejectNegative Var(common_deferred_options) Defer
1563 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 Enable an optimization pass.
1566 Common Joined RejectNegative Var(common_deferred_options) Defer
1567 -fdump-<type> Dump various compiler internals to a file.
1570 Driver RejectNegative
1573 Common RejectNegative Joined Var(flag_dump_final_insns)
1574 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1577 Common RejectNegative Joined Var(flag_dump_go_spec)
1578 -fdump-go-spec=filename Write all declarations to file as Go code.
1581 Common Var(flag_dump_noaddr)
1582 Suppress output of addresses in debugging dumps.
1585 Common Driver Var(flag_report_bug)
1586 Collect and dump debug information into temporary file if ICE in C/C++
1589 fdump-internal-locations
1590 Common Var(flag_dump_locations) Init(0)
1591 Dump detailed information on GCC's internal representation of source code locations.
1594 Common Var(flag_dump_passes) Init(0)
1595 Dump optimization passes.
1598 Common Var(flag_dump_unnumbered)
1599 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1601 fdump-unnumbered-links
1602 Common Var(flag_dump_unnumbered_links)
1603 Suppress output of previous and next insn numbers in debugging dumps.
1606 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1607 Enable CFI tables via GAS assembler directives.
1610 Common Var(flag_early_inlining) Init(1) Optimization
1611 Perform early inlining.
1613 feliminate-dwarf2-dups
1615 Does nothing. Preserved for backward compatibility.
1618 Common Var(flag_ipa_sra) Init(0) Optimization
1619 Perform interprocedural reduction of aggregates.
1621 feliminate-unused-debug-symbols
1622 Common Var(flag_debug_only_used_symbols) Init(1)
1623 Perform unused symbol elimination in debug info.
1625 feliminate-unused-debug-types
1626 Common Var(flag_eliminate_unused_debug_types) Init(1)
1627 Perform unused type elimination in debug info.
1629 femit-class-debug-always
1630 Common Var(flag_emit_class_debug_always) Init(0)
1631 Do not suppress C++ class debug information.
1634 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1635 Enable exception handling.
1637 fexpensive-optimizations
1638 Common Var(flag_expensive_optimizations) Optimization
1639 Perform a number of minor, expensive optimizations.
1642 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1643 -fexcess-precision=[fast|standard|16] Specify handling of excess floating-point precision.
1646 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1649 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1652 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1655 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1657 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1658 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1659 fpermitted-flt-eval-methods=
1660 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1661 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1664 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)
1667 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1670 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1676 Common Var(flag_fat_lto_objects)
1677 Output lto objects containing both the intermediate language and binary output.
1680 Common Var(flag_finite_math_only) Optimization SetByCombined
1681 Assume no NaNs or infinities are generated.
1684 Common Var(flag_finite_loops) Optimization Init(0)
1685 Assume that loops with an exit will terminate and not loop indefinitely.
1688 Common Joined RejectNegative Var(common_deferred_options) Defer
1689 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1692 Common Var(flag_float_store) Optimization
1693 Don't allocate floats and doubles in extended-precision registers.
1697 Does nothing. Preserved for backward compatibility.
1700 Common Var(flag_forward_propagate) Optimization
1701 Perform a forward propagation pass on RTL.
1704 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1705 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1708 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1711 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1714 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_ON)
1717 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1719 ffp-int-builtin-inexact
1720 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1721 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1723 ; Nonzero means don't put addresses of constant functions in registers.
1724 ; Used for compiling the Unix kernel, where strange substitutions are
1725 ; done on the assembly output.
1727 Common Var(flag_no_function_cse,0) Optimization
1728 Allow function addresses to be held in registers.
1731 Common Var(flag_function_sections)
1732 Place each function into its own section.
1735 Common Var(flag_gcse) Optimization
1736 Perform global common subexpression elimination.
1739 Common Var(flag_gcse_lm) Init(1) Optimization
1740 Perform enhanced load motion during global common subexpression elimination.
1743 Common Var(flag_gcse_sm) Init(0) Optimization
1744 Perform store motion after global common subexpression elimination.
1747 Common Var(flag_gcse_las) Init(0) Optimization
1748 Perform redundant load after store elimination in global common subexpression
1752 Common Var(flag_gcse_after_reload) Optimization
1753 Perform global common subexpression elimination after register allocation has
1757 Name(dwarf_gnat_encodings) Type(int)
1760 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1763 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1766 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1769 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1770 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1772 ; This option is not documented yet as its semantics will change.
1774 Common Var(flag_graphite) Optimization
1775 Enable in and out of Graphite representation.
1778 Common Var(flag_graphite_identity) Optimization
1779 Enable Graphite Identity transformation.
1781 fhoist-adjacent-loads
1782 Common Var(flag_hoist_adjacent_loads) Optimization
1783 Enable hoisting adjacent loads to encourage generating conditional move
1787 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1788 ; Always keep a pointer to a live memory block
1791 Common Var(flag_large_source_files) Init(0)
1792 Improve GCC's ability to track column numbers in large source files,
1793 at the expense of slower compilation.
1795 floop-parallelize-all
1796 Common Var(flag_loop_parallelize_all) Optimization
1797 Mark all loops as parallel.
1800 Common Alias(floop-nest-optimize)
1801 Enable loop nest transforms. Same as -floop-nest-optimize.
1804 Common Var(flag_loop_interchange) Optimization
1805 Enable loop interchange on trees.
1808 Common Alias(floop-nest-optimize)
1809 Enable loop nest transforms. Same as -floop-nest-optimize.
1811 floop-unroll-and-jam
1812 Common Var(flag_unroll_jam) Optimization
1813 Perform unroll-and-jam on loops.
1817 Enable support for GNU transactional memory.
1820 Common Var(flag_gnu_unique) Init(1)
1821 Use STB_GNU_UNIQUE if supported by the assembler.
1825 Does nothing. Preserved for backward compatibility.
1828 Common Var(flag_loop_nest_optimize) Optimization
1829 Enable the loop nest optimizer.
1831 fstrict-volatile-bitfields
1832 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1833 Force bitfield accesses to match their type width.
1836 Common Var(flag_store_merging) Optimization
1837 Merge adjacent stores.
1839 fguess-branch-probability
1840 Common Var(flag_guess_branch_prob) Optimization
1841 Enable guessing of branch probabilities.
1844 Common Driver Var(flag_hardened)
1845 Enable various security-relevant flags.
1848 Common Var(flag_harden_compares) Optimization
1849 Harden conditionals not used in branches, checking reversed conditions.
1851 fharden-conditional-branches
1852 Common Var(flag_harden_conditional_branches) Optimization
1853 Harden conditional branches by checking reversed conditions.
1855 fharden-control-flow-redundancy
1856 Common Var(flag_harden_control_flow_redundancy) Optimization
1857 Harden control flow by recording and checking execution paths.
1860 Common Var(flag_harden_control_flow_redundancy_skip_leaf) Optimization
1861 Disable CFR in leaf functions.
1863 fhardcfr-check-returning-calls
1864 Common Var(flag_harden_control_flow_redundancy_check_returning_calls) Init(-1) Optimization
1865 Check CFR execution paths also before calls followed by returns of their results.
1867 fhardcfr-check-exceptions
1868 Common Var(flag_harden_control_flow_redundancy_check_exceptions) Init(-1) Optimization
1869 Check CFR execution paths also when exiting a function through an exception.
1871 fhardcfr-check-noreturn-calls=
1872 Common Joined RejectNegative Enum(hardcfr_check_noreturn_calls) Var(flag_harden_control_flow_redundancy_check_noreturn) Init(HCFRNR_UNSPECIFIED) Optimization
1873 -fhardcfr-check-noreturn-calls=[always|no-xthrow|nothrow|never] Check CFR execution paths also before calling noreturn functions.
1876 Name(hardcfr_check_noreturn_calls) Type(enum hardcfr_noret) UnknownError(unknown hardcfr noreturn checking level %qs)
1879 Enum(hardcfr_check_noreturn_calls) String(never) Value(HCFRNR_NEVER)
1882 Enum(hardcfr_check_noreturn_calls) String(nothrow) Value(HCFRNR_NOTHROW)
1885 Enum(hardcfr_check_noreturn_calls) String(no-xthrow) Value(HCFRNR_NO_XTHROW)
1888 Enum(hardcfr_check_noreturn_calls) String(always) Value(HCFRNR_ALWAYS)
1890 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1891 ; Generate position-independent code for executables if possible
1892 ; On SVR4 targets, it also controls whether or not to emit a
1893 ; string identifying the compiler.
1895 Common Var(flag_no_ident,0)
1896 Process #ident directives.
1899 Common Var(flag_if_conversion) Optimization
1900 Perform conversion of conditional jumps to branchless equivalents.
1903 Common Var(flag_if_conversion2) Optimization
1904 Perform conversion of conditional jumps to conditional execution.
1907 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1908 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1911 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1914 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1917 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1920 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1922 ftree-loop-if-convert
1923 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1924 Convert conditional jumps in innermost loops to branchless equivalents.
1926 ftree-loop-if-convert-stores
1928 Does nothing. Preserved for backward compatibility.
1930 ; -finhibit-size-directive inhibits output of .size for ELF.
1931 ; This is used only for compiling crtstuff.c,
1932 ; and it may be extended to other effects
1933 ; needed for crtstuff.c on other systems.
1934 finhibit-size-directive
1935 Common Var(flag_inhibit_size_directive)
1936 Do not generate .size directives.
1939 Common Var(flag_indirect_inlining) Optimization
1940 Perform indirect inlining.
1942 ; General flag to enable inlining. Specifying -fno-inline will disable
1943 ; all inlining apart from always-inline functions.
1945 Common Var(flag_no_inline,0) Init(0) Optimization
1946 Enable inlining of function declared \"inline\", disabling disables all inlining.
1948 finline-small-functions
1949 Common Var(flag_inline_small_functions) Optimization
1950 Integrate functions into their callers when code size is known not to grow.
1953 Common Var(flag_inline_functions) Optimization
1954 Integrate functions not declared \"inline\" into their callers when profitable.
1956 finline-functions-called-once
1957 Common Var(flag_inline_functions_called_once) Optimization
1958 Integrate functions only required by their single caller.
1961 Common RejectNegative Joined Alias(finline-limit=)
1964 Common RejectNegative Joined UInteger
1965 -finline-limit=<number> Limit the size of inlined functions to <number>.
1968 Common Var(flag_inline_atomics) Init(1) Optimization
1969 Inline __atomic operations when a lock free instruction sequence is available.
1972 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_ALL) Enum(ilsop_fn) Init(ILSOP_NONE) Optimization Undocumented
1974 fno-inline-stringops
1975 Common RejectNegative Enum(ilsop_fn) Var(flag_inline_stringops, ILSOP_NONE) Enum(ilsop_fn) Optimization Undocumented
1978 Common Joined Var(flag_inline_stringops) EnumSet Enum(ilsop_fn) Optimization
1979 -finline-stringops[=memcmp|memcpy|memmove|memset]
1980 Expand supported mem/str operations inline, even if against optimization.
1983 Name(ilsop_fn) Type(enum ilsop_fn) UnknownError(unavailable stringop for inlining %qs)
1985 ; This is not part of any set.
1987 ; Enum(ilsop_fn) String(none) Value(ILSOP_NONE)
1990 Enum(ilsop_fn) String(memcmp) Value(ILSOP_MEMCMP) Set(1)
1993 Enum(ilsop_fn) String(memcpy) Value(ILSOP_MEMCPY) Set(2)
1996 Enum(ilsop_fn) String(memmove) Value(ILSOP_MEMMOVE) Set(3)
1999 Enum(ilsop_fn) String(memset) Value(ILSOP_MEMSET) Set(4)
2001 ; This is not part of any set either.
2003 ; Enum(ilsop_fn) String(all) Value(ILSOP_ALL)
2006 Common RejectNegative Alias(fcf-protection=,full)
2009 Common Joined RejectNegative Enum(cf_protection_level) EnumSet Var(flag_cf_protection) Init(CF_NONE)
2010 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
2011 instructions have valid targets.
2014 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
2017 Enum(cf_protection_level) String(full) Value(CF_FULL) Set(1)
2020 Enum(cf_protection_level) String(branch) Value(CF_BRANCH) Set(2)
2023 Enum(cf_protection_level) String(return) Value(CF_RETURN) Set(3)
2026 Enum(cf_protection_level) String(check) Value(CF_CHECK) Set(4)
2029 Enum(cf_protection_level) String(none) Value(CF_NONE) Set(1)
2031 finstrument-functions
2032 Common Var(flag_instrument_function_entry_exit,1)
2033 Instrument function entry and exit with profiling calls.
2035 finstrument-functions-once
2036 Common Var(flag_instrument_function_entry_exit,2)
2037 Instrument function entry and exit with profiling calls invoked once.
2039 finstrument-functions-exclude-function-list=
2040 Common RejectNegative Joined
2041 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
2043 finstrument-functions-exclude-file-list=
2044 Common RejectNegative Joined
2045 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
2048 Common Var(flag_ipa_cp) Optimization
2049 Perform interprocedural constant propagation.
2052 Common Var(flag_ipa_cp_clone) Optimization
2053 Perform cloning to make Interprocedural constant propagation stronger.
2057 Does nothing. Preserved for backward compatibility.
2060 Common Var(flag_ipa_bit_cp) Optimization
2061 Perform interprocedural bitwise constant propagation.
2064 Common Var(flag_ipa_modref) Optimization
2065 Perform interprocedural modref analysis.
2068 Common Var(flag_ipa_profile) Init(0) Optimization
2069 Perform interprocedural profile propagation.
2072 Common Var(flag_ipa_pta) Init(0) Optimization
2073 Perform interprocedural points-to analysis.
2076 Common Var(flag_ipa_pure_const) Init(0) Optimization
2077 Discover pure and const functions.
2080 Common Var(flag_ipa_icf) Optimization
2081 Perform Identical Code Folding for functions and read-only variables.
2084 Common Var(flag_ipa_icf_functions) Optimization
2085 Perform Identical Code Folding for functions.
2088 Common Var(flag_ipa_icf_variables) Optimization
2089 Perform Identical Code Folding for variables.
2092 Common Var(flag_ipa_reference) Init(0) Optimization
2093 Discover read-only and non addressable static variables.
2095 fipa-reference-addressable
2096 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
2097 Discover read-only, write-only and non-addressable static variables.
2099 fipa-stack-alignment
2100 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
2101 Reduce stack alignment on call sites if possible.
2105 Does nothing. Preserved for backward compatibility.
2109 Does nothing. Preserved for backward compatibility.
2112 Common Var(flag_ipa_vrp) Optimization
2113 Perform IPA Value Range Propagation.
2116 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
2117 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
2119 fipa-strict-aliasing
2120 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
2121 Assume strict aliasing rules apply across (uninlined) function boundaries.
2124 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
2127 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2130 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2133 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2134 -fira-region=[one|all|mixed] Set regions for IRA.
2137 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2140 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2143 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2146 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2149 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2150 Use IRA based register pressure calculation
2151 in RTL hoist optimizations.
2154 Common Var(flag_ira_loop_pressure) Optimization
2155 Use IRA based register pressure calculation
2156 in RTL loop optimizations.
2158 fira-share-save-slots
2159 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2160 Share slots for saving different hard registers.
2162 fira-share-spill-slots
2163 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2164 Share stack slots for spilled pseudo-registers.
2167 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2168 -fira-verbose=<number> Control IRA's level of diagnostic messages.
2171 Common Var(flag_ivopts) Init(1) Optimization
2172 Optimize induction variables on trees.
2175 Common Var(flag_jump_tables) Init(1) Optimization
2176 Use jump tables for sufficiently large switch statements.
2179 Common Var(flag_bit_tests) Init(1) Optimization
2180 Use bit tests for sufficiently large switch statements.
2182 fkeep-inline-functions
2183 Common Var(flag_keep_inline_functions)
2184 Generate code for functions even if they are fully inlined.
2186 fkeep-static-functions
2187 Common Var(flag_keep_static_functions)
2188 Generate code for static functions even if they are never called.
2191 Common Var(flag_keep_static_consts) Init(1)
2192 Emit static const variables even if they are not used.
2195 Common Var(flag_leading_underscore) Init(-1)
2196 Give external symbols a leading underscore.
2200 Does nothing. Preserved for backward compatibility.
2203 Common Var(flag_lra_remat) Optimization
2204 Do CFG-sensitive rematerialization in LRA.
2208 Enable link-time optimization.
2211 Common RejectNegative Joined Var(flag_lto)
2212 Link-time optimization with number of parallel jobs or jobserver.
2215 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2218 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2221 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2224 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2227 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2230 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2233 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2234 Specify the algorithm to partition symbols and vars at linktime.
2236 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2237 flto-compression-level=
2238 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2239 Use zlib/zstd compression level <number> for IL.
2241 flto-odr-type-merging
2243 Does nothing. Preserved for backward compatibility.
2246 Common Var(flag_lto_report) Init(0)
2247 Report various link-time optimization statistics.
2250 Common Var(flag_lto_report_wpa) Init(0)
2251 Report various link-time optimization statistics for WPA only.
2254 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2255 Set errno after built-in math functions.
2258 Common Joined RejectNegative UInteger Var(flag_max_errors)
2259 -fmax-errors=<number> Maximum number of errors to report.
2262 Common Var(mem_report)
2263 Report on permanent memory allocation.
2266 Common Var(mem_report_wpa)
2267 Report on permanent memory allocation in WPA only.
2269 ; This will attempt to merge constant section constants, if 1 only
2270 ; string constants and constants from constant pool, if 2 also constant
2272 fmerge-all-constants
2273 Common Var(flag_merge_constants,2) Init(1)
2274 Attempt to merge identical constants and constant variables.
2277 Common Var(flag_merge_constants,1)
2278 Attempt to merge identical constants across compilation units.
2280 fmerge-debug-strings
2281 Common Var(flag_merge_debug_strings) Init(1)
2282 Attempt to merge identical debug strings across compilation units.
2285 Common RejectNegative Joined UInteger
2286 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
2288 fmin-function-alignment=
2289 Common Joined RejectNegative UInteger Var(flag_min_function_alignment) Optimization
2290 Align the start of every function.
2293 Common Var(flag_modulo_sched) Optimization
2294 Perform SMS based modulo scheduling before the first scheduling pass.
2296 fmodulo-sched-allow-regmoves
2297 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2298 Perform SMS based modulo scheduling with register moves allowed.
2300 fmove-loop-invariants
2301 Common Var(flag_move_loop_invariants) Optimization
2302 Move loop invariant computations out of loops.
2305 Common Var(flag_move_loop_stores) Optimization
2306 Move stores out of loops.
2309 Common Driver RejectNegative
2310 Building block for specs-based multilib-aware TFLAGS.
2313 Common Var(flag_dce) Init(1) Optimization
2314 Use the RTL dead code elimination pass.
2317 Common Var(flag_dse) Init(0) Optimization
2318 Use the RTL dead store elimination pass.
2320 freschedule-modulo-scheduled-loops
2321 Common Var(flag_resched_modulo_sched) Optimization
2322 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2324 fnon-call-exceptions
2325 Common Var(flag_non_call_exceptions) Optimization
2326 Support synchronous non-call exceptions.
2329 Driver Joined MissingArgError(targets missing after %qs)
2332 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2333 -foffload-options=<targets>=<options> Specify options for the offloading targets.
2336 Common Joined RejectNegative Enum(offload_abi)
2337 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2340 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2343 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2346 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2349 Common Var(flag_omit_frame_pointer) Optimization
2350 When possible do not generate stack frames.
2352 fopenmp-target-simd-clone
2353 Common Alias(fopenmp-target-simd-clone=,any,none)
2355 fopenmp-target-simd-clone=
2356 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2357 Generate SIMD clones for functions with the OpenMP declare target directive.
2360 Name(target_simd_clone_device) Type(int)
2363 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2366 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2369 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2372 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2375 Common Var(flag_opt_info) Optimization
2376 Enable all optimization info dumps on stderr.
2379 Common Joined RejectNegative Var(common_deferred_options) Defer
2380 -fopt-info[-<type>=filename] Dump compiler optimization details.
2382 fsave-optimization-record
2383 Common Var(flag_save_optimization_record) Optimization
2384 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2386 foptimize-register-move
2388 Does nothing. Preserved for backward compatibility.
2390 foptimize-sibling-calls
2391 Common Var(flag_optimize_sibling_calls) Optimization
2392 Optimize sibling and tail recursive calls.
2395 Common Var(flag_partial_inlining) Optimization
2396 Perform partial inlining.
2399 Common Var(pre_ipa_mem_report)
2400 Report on memory allocation before interprocedural optimization.
2402 fpost-ipa-mem-report
2403 Common Var(post_ipa_mem_report)
2404 Report on memory allocation before interprocedural optimization.
2407 Common Var(flag_pack_struct) Optimization
2408 Pack structure members together without holes.
2411 Common RejectNegative Joined UInteger Optimization
2412 -fpack-struct=<number> Set initial maximum structure member alignment.
2415 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2416 Return small aggregates in memory, not registers.
2419 Common Var(flag_peel_loops) Optimization
2420 Perform loop peeling.
2423 Common Var(flag_no_peephole,0) Optimization
2424 Enable machine specific peephole optimizations.
2427 Common Var(flag_peephole2) Optimization
2428 Enable an RTL peephole pass before sched2.
2431 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2432 Generate position-independent code if possible (large mode).
2435 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2436 Generate position-independent code for executables if possible (large mode).
2439 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2440 Generate position-independent code if possible (small mode).
2443 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2444 Generate position-independent code for executables if possible (small mode).
2447 Common Var(flag_plt) Init(1) Optimization
2448 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2451 Common Joined RejectNegative Var(common_deferred_options) Defer
2452 Specify a plugin to load.
2455 Common Joined RejectNegative Var(common_deferred_options) Defer
2456 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2458 fpredictive-commoning
2459 Common Var(flag_predictive_commoning) Optimization
2460 Run predictive commoning optimization.
2462 fprefetch-loop-arrays
2463 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2464 Generate prefetch instructions, if available, for arrays in loops.
2467 Common Var(profile_flag)
2468 Enable basic program profiling code.
2471 Common Var(profile_abs_path_flag)
2472 Generate absolute source path names for gcov.
2475 Common Var(profile_arc_flag)
2476 Insert arc-based program profiling code.
2479 Common Var(condition_coverage_flag)
2480 Insert condition coverage profiling code.
2483 Common Joined RejectNegative Var(profile_data_prefix)
2484 Set the top-level directory for storing the profile data.
2485 The default is 'pwd'.
2488 Common Joined RejectNegative Var(profile_note_location)
2489 Select the name for storing the profile note file.
2492 Common Var(flag_profile_correction)
2493 Enable correction of flow inconsistent profile data input.
2496 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2497 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2499 fprofile-filter-files=
2500 Common Joined RejectNegative Var(flag_profile_filter_files)
2501 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2503 fprofile-exclude-files=
2504 Common Joined RejectNegative Var(flag_profile_exclude_files)
2505 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2508 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2511 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2514 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2517 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2519 fprofile-reproducible=
2520 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2521 -fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate.
2524 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2527 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2530 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2533 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2535 fprofile-prefix-path=
2536 Common Joined RejectNegative Var(profile_prefix_path)
2537 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2539 fprofile-prefix-map=
2540 Common Joined RejectNegative Var(common_deferred_options) Defer
2541 -fprofile-prefix-map=<old>=<new> Map one directory name to another in GCOV coverage result.
2545 Enable common options for generating profile info for profile feedback directed optimizations.
2548 Common Joined RejectNegative
2549 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2551 fprofile-info-section
2552 Common RejectNegative
2553 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2555 fprofile-info-section=
2556 Common Joined RejectNegative Var(profile_info_section)
2557 Register the profile information in the specified section instead of using a constructor/destructor.
2559 fprofile-partial-training
2560 Common Var(flag_profile_partial_training) Optimization
2561 Do not assume that functions never executed during the train run are cold.
2564 Common Var(flag_profile_use)
2565 Enable common options for performing profile feedback directed optimizations.
2568 Common Joined RejectNegative
2569 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2572 Common Var(flag_profile_values)
2573 Insert code to profile values of expressions.
2576 Common Var(profile_report)
2577 Report on consistency of profile.
2579 fprofile-reorder-functions
2580 Common Var(flag_profile_reorder_functions) Optimization
2581 Enable function reordering that improves code placement.
2583 fpatchable-function-entry=
2584 Common Var(flag_patchable_function_entry) Joined Optimization
2585 Insert NOP instructions at each function entry.
2588 Common Var(common_deferred_options) Defer
2591 Common Joined RejectNegative Var(common_deferred_options) Defer
2592 -frandom-seed=<string> Make compile reproducible using <string>.
2594 ; This switch causes the command line that was used to create an
2595 ; object file to be recorded into the object file. The exact format
2596 ; of this recording is target and binary file format dependent.
2597 ; It is related to the -fverbose-asm switch, but that switch only
2598 ; records information in the assembler output file as comments, so
2599 ; they never reach the object file.
2600 frecord-gcc-switches
2601 Common Var(flag_record_gcc_switches)
2602 Record gcc command line switches in the object file.
2605 Common Var(flag_pcc_struct_return,0) Optimization
2606 Return small aggregates in registers.
2610 Does nothing. Preserved for backward compatibility.
2613 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2614 Tell DSE that the storage for a C++ object is dead when the constructor
2615 starts and when the destructor finishes.
2618 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2620 flimit-function-alignment
2621 Common Var(flag_limit_function_alignment) Optimization Init(0)
2624 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2627 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2628 -flive-patching=[inline-only-static|inline-clone] Control IPA
2629 optimizations to provide a safe compilation for live-patching. At the same
2630 time, provides multiple-level control on the enabled IPA optimizations.
2633 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2636 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2639 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2642 Common Var(flag_allocation_dce) Init(1) Optimization
2643 Tell DCE to remove unused C++ allocations.
2645 flive-range-shrinkage
2646 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2647 Relief of register pressure through live range shrinkage.
2650 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2651 Perform a register renaming optimization pass.
2654 Common Var(flag_schedule_fusion) Init(2) Optimization
2655 Perform a target dependent instruction fusion optimization pass.
2658 Common Var(flag_reorder_blocks) Optimization
2659 Reorder basic blocks to improve code placement.
2661 freorder-blocks-algorithm=
2662 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2663 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2666 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2669 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2672 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2674 freorder-blocks-and-partition
2675 Common Var(flag_reorder_blocks_and_partition) Optimization
2676 Reorder basic blocks and partition into hot and cold sections.
2679 Common Var(flag_reorder_functions) Optimization
2680 Reorder functions to improve code placement.
2682 frerun-cse-after-loop
2683 Common Var(flag_rerun_cse_after_loop) Optimization
2684 Add a common subexpression elimination pass after loop optimizations.
2688 Does nothing. Preserved for backward compatibility.
2691 Common Var(flag_rounding_math) Optimization SetByCombined
2692 Disable optimizations that assume default FP rounding behavior.
2695 Common Var(flag_schedule_interblock) Init(1) Optimization
2696 Enable scheduling across basic blocks.
2699 Common Var(flag_sched_pressure) Init(0) Optimization
2700 Enable register pressure sensitive insn scheduling.
2703 Common Var(flag_schedule_speculative) Init(1) Optimization
2704 Allow speculative motion of non-loads.
2707 Common Var(flag_schedule_speculative_load) Optimization
2708 Allow speculative motion of some loads.
2710 fsched-spec-load-dangerous
2711 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2712 Allow speculative motion of more loads.
2715 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2716 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2718 fsched2-use-superblocks
2719 Common Var(flag_sched2_use_superblocks) Optimization
2720 If scheduling post reload, do superblock scheduling.
2724 Does nothing. Preserved for backward compatibility.
2727 Common Var(flag_schedule_insns) Optimization
2728 Reschedule instructions before register allocation.
2731 Common Var(flag_schedule_insns_after_reload) Optimization
2732 Reschedule instructions after register allocation.
2734 ; This flag should be on when a target implements non-trivial
2735 ; scheduling hooks, maybe saving some information for its own sake.
2736 ; On IA64, for example, this is used for correct bundling.
2737 fselective-scheduling
2738 Common Var(flag_selective_scheduling) Optimization
2739 Schedule instructions using selective scheduling algorithm.
2741 fselective-scheduling2
2742 Common Var(flag_selective_scheduling2) Optimization
2743 Run selective scheduling after reload.
2746 Common Undocumented Joined Var(flag_self_test)
2747 Run self-tests, using the given path to locate test files.
2749 fsel-sched-pipelining
2750 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2751 Perform software pipelining of inner loops during selective scheduling.
2753 fsel-sched-pipelining-outer-loops
2754 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2755 Perform software pipelining of outer loops during selective scheduling.
2757 fsel-sched-reschedule-pipelined
2758 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2759 Reschedule pipelined regions without pipelining.
2761 fsemantic-interposition
2762 Common Var(flag_semantic_interposition) Init(1) Optimization
2763 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2765 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2766 ; of stalled insns into the ready list.
2767 fsched-stalled-insns
2768 Common Var(flag_sched_stalled_insns) Optimization UInteger
2769 Allow premature scheduling of queued insns.
2771 fsched-stalled-insns=
2772 Common RejectNegative Joined UInteger Optimization
2773 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2775 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2776 ; be examined for a dependency on a stalled insn that is candidate for
2777 ; premature removal from the queue of stalled insns into the ready list (has
2778 ; an effect only if the flag 'sched_stalled_insns' is set).
2779 fsched-stalled-insns-dep
2780 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2781 Set dependence distance checking in premature scheduling of queued insns.
2783 fsched-stalled-insns-dep=
2784 Common RejectNegative Joined UInteger Optimization
2785 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2787 fsched-group-heuristic
2788 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2789 Enable the group heuristic in the scheduler.
2791 fsched-critical-path-heuristic
2792 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2793 Enable the critical path heuristic in the scheduler.
2795 fsched-spec-insn-heuristic
2796 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2797 Enable the speculative instruction heuristic in the scheduler.
2799 fsched-rank-heuristic
2800 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2801 Enable the rank heuristic in the scheduler.
2803 fsched-last-insn-heuristic
2804 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2805 Enable the last instruction heuristic in the scheduler.
2807 fsched-dep-count-heuristic
2808 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2809 Enable the dependent count heuristic in the scheduler.
2812 Common Var(flag_section_anchors) Optimization
2813 Access data in the same section from shared anchor points.
2817 Does nothing. Preserved for backward compatibility.
2821 Does nothing. Preserved for backward compatibility.
2824 Common Var(flag_ree) Init(0) Optimization
2825 Turn on Redundant Extensions Elimination pass.
2828 Common Var(flag_show_column) Init(1)
2829 Show column numbers in diagnostics, when available. Default on.
2832 Common Var(flag_shrink_wrap) Optimization
2833 Emit function prologues only before parts of the function that need it,
2834 rather than at the top of the function.
2836 fshrink-wrap-separate
2837 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2838 Shrink-wrap parts of the prologue and epilogue separately.
2841 Common Var(flag_signaling_nans) Optimization SetByCombined
2842 Disable optimizations observable by IEEE signaling NaNs.
2845 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2846 Disable floating point optimizations that ignore the IEEE signedness of zero.
2848 fsingle-precision-constant
2849 Common Var(flag_single_precision_constant) Optimization
2850 Convert floating point constants to single precision constants.
2852 fsplit-ivs-in-unroller
2853 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2854 Split lifetimes of induction variables when loops are unrolled.
2857 Common Var(flag_split_stack) Init(-1)
2858 Generate discontiguous stack frames.
2861 Common Var(flag_split_wide_types) Optimization
2862 Split wide types into independent registers.
2864 fsplit-wide-types-early
2865 Common Var(flag_split_wide_types_early) Optimization
2866 Split wide types into independent registers earlier.
2869 Common Var(flag_ssa_backprop) Init(1) Optimization
2870 Enable backward propagation of use properties at the SSA level.
2873 Common Var(flag_ssa_phiopt) Optimization
2874 Optimize conditional patterns using SSA PHI nodes.
2877 Common Var(flag_stdarg_opt) Init(1) Optimization
2878 Optimize amount of stdarg registers saved to stack at start of function.
2880 fvariable-expansion-in-unroller
2881 Common Var(flag_variable_expansion_in_unroller) Optimization
2882 Apply variable expansion when loops are unrolled.
2885 Common RejectNegative Joined Optimization
2886 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2889 Common Alias(fstack-check=, specific, no)
2890 Insert stack checking code into the program. Same as -fstack-check=specific.
2892 fstack-clash-protection
2893 Common Var(flag_stack_clash_protection) Optimization
2894 Insert code to probe each page of stack space as it is allocated to protect
2895 from stack-clash style attacks.
2898 Common Var(common_deferred_options) Defer
2900 fstack-limit-register=
2901 Common RejectNegative Joined Var(common_deferred_options) Defer
2902 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2904 fstack-limit-symbol=
2905 Common RejectNegative Joined Var(common_deferred_options) Defer
2906 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2909 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2910 Use propolice as a stack protection method.
2912 fstack-protector-all
2913 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2914 Use a stack protection method for every function.
2916 fstack-protector-strong
2917 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2918 Use a smart stack protection method for certain functions.
2920 fstack-protector-explicit
2921 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2922 Use stack protection method only for functions with the stack_protect attribute.
2925 Common RejectNegative Var(flag_stack_usage)
2926 Output stack usage information on a per-function basis.
2930 Does nothing. Preserved for backward compatibility.
2932 ; Nonzero if we should do (language-dependent) alias analysis.
2933 ; Typically, this analysis will assume that expressions of certain
2934 ; types do not alias expressions of certain other types. Only used
2935 ; if alias analysis (in general) is enabled.
2937 Common Var(flag_strict_aliasing) Optimization
2938 Assume strict aliasing rules apply.
2942 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2945 Common RejectNegative Var(flag_strub, 0)
2946 Disable stack scrub entirely, disregarding strub attributes.
2949 Common RejectNegative Var(flag_strub, -4)
2950 Enable stack scrub as per attributes, with strict call checking.
2952 ; If any strub-enabling attribute is seen when the default or strict
2953 ; initializer values are in effect, flag_strub is bumped up by 2. The
2954 ; scrub mode gate function will then bump these initializer values to
2955 ; 0 if no strub-enabling attribute is seen. This minimizes the strub
2958 Common RejectNegative Var(flag_strub, -3) Init(-3)
2959 Restore default strub mode: as per attributes, with relaxed checking.
2962 Common RejectNegative Var(flag_strub, 3)
2963 Enable stack scrubbing for all viable functions.
2966 Common RejectNegative Var(flag_strub, 1)
2967 Enable at-calls stack scrubbing for all viable functions.
2970 Common RejectNegative Var(flag_strub, 2)
2971 Enable internal stack scrubbing for all viable functions.
2974 Common Var(flag_sync_libcalls) Init(1)
2975 Implement __atomic operations via libcalls to legacy __sync functions.
2978 Common Var(flag_syntax_only)
2979 Check for syntax errors, then stop.
2982 Common Var(flag_test_coverage)
2983 Create data files needed by \"gcov\".
2986 Common Var(flag_thread_jumps) Optimization
2987 Perform jump threading optimizations.
2990 Common Var(time_report)
2991 Report the time taken by each compiler pass.
2993 ftime-report-details
2994 Common Var(time_report_details)
2995 Record times taken by sub-phases separately.
2998 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2999 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
3002 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
3005 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
3008 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
3011 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
3014 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
3017 Common Var(flag_toplevel_reorder) Init(2) Optimization
3018 Reorder top level functions, variables, and asms.
3021 Common Var(flag_tracer) Optimization
3022 Perform superblock formation via tail duplication.
3025 Common Var(flag_trampolines) Init(HEAP_TRAMPOLINES_INIT)
3026 For targets that normally need trampolines for nested functions, always
3027 generate them instead of using descriptors.
3030 Common Joined RejectNegative Enum(trampoline_impl) Var(flag_trampoline_impl) Init(HEAP_TRAMPOLINES_INIT ? TRAMPOLINE_IMPL_HEAP : TRAMPOLINE_IMPL_STACK)
3031 Whether trampolines are generated in executable memory rather than
3035 Name(trampoline_impl) Type(enum trampoline_impl) UnknownError(unknown trampoline implementation %qs)
3038 Enum(trampoline_impl) String(stack) Value(TRAMPOLINE_IMPL_STACK)
3041 Enum(trampoline_impl) String(heap) Value(TRAMPOLINE_IMPL_HEAP)
3044 ; Zero means that floating-point math operations cannot generate a
3045 ; (user-visible) trap. This is the case, for example, in nonstop
3046 ; IEEE 754 arithmetic.
3048 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
3049 Assume floating-point operations can trap.
3052 Common Var(flag_trapv) Optimization
3053 Trap for signed overflow in addition, subtraction and multiplication.
3056 Common Var(flag_tree_ccp) Optimization
3057 Enable SSA-CCP optimization on trees.
3060 Common Var(flag_tree_bit_ccp) Optimization
3061 Enable SSA-BIT-CCP optimization on trees.
3065 Does nothing. Preserved for backward compatibility.
3068 Common Var(flag_tree_ch) Optimization
3069 Enable loop header copying on trees.
3071 ftree-coalesce-inlined-vars
3072 Common Ignore RejectNegative
3073 Does nothing. Preserved for backward compatibility.
3076 Common Var(flag_tree_coalesce_vars) Optimization
3077 Enable SSA coalescing of user variables.
3081 Does nothing. Preserved for backward compatibility.
3084 Common Var(flag_tree_copy_prop) Optimization
3085 Enable copy propagation on trees.
3087 ftree-store-copy-prop
3089 Does nothing. Preserved for backward compatibility.
3092 Common Var(flag_tree_cselim) Optimization
3093 Transform condition stores into unconditional ones.
3095 ftree-switch-conversion
3096 Common Var(flag_tree_switch_conversion) Optimization
3097 Perform conversions of switch initializations.
3100 Common Var(flag_tree_dce) Optimization
3101 Enable SSA dead code elimination optimization on trees.
3103 ftree-dominator-opts
3104 Common Var(flag_tree_dom) Optimization
3105 Enable dominator optimizations.
3108 Common Var(flag_tree_tail_merge) Optimization
3109 Enable tail merging on trees.
3112 Common Var(flag_tree_dse) Optimization
3113 Enable dead store elimination.
3116 Common Var(flag_tree_forwprop) Init(1) Optimization
3117 Enable forward propagation on trees.
3120 Common Var(flag_tree_fre) Optimization
3121 Enable Full Redundancy Elimination (FRE) on trees.
3124 Common Var(flag_optimize_strlen) Optimization
3125 Enable string length optimizations on trees.
3127 fisolate-erroneous-paths-dereference
3128 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
3129 Detect paths that trigger erroneous or undefined behavior due to
3130 dereferencing a null pointer. Isolate those paths from the main control
3131 flow and turn the statement with erroneous or undefined behavior into a trap.
3133 fisolate-erroneous-paths-attribute
3134 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
3135 Detect paths that trigger erroneous or undefined behavior due to a null value
3136 being used in a way forbidden by a returns_nonnull or nonnull
3137 attribute. Isolate those paths from the main control flow and turn the
3138 statement with erroneous or undefined behavior into a trap.
3140 ftree-loop-distribution
3141 Common Var(flag_tree_loop_distribution) Optimization
3142 Enable loop distribution on trees.
3144 ftree-loop-distribute-patterns
3145 Common Var(flag_tree_loop_distribute_patterns) Optimization
3146 Enable loop distribution for patterns transformed into a library call.
3149 Common Var(flag_tree_loop_im) Init(1) Optimization
3150 Enable loop invariant motion on trees.
3153 Common Alias(floop-nest-optimize)
3154 Enable loop nest transforms. Same as -floop-nest-optimize.
3157 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
3158 Create canonical induction variables in loops.
3161 Common Var(flag_tree_loop_optimize) Init(1) Optimization
3162 Enable loop optimizations on tree level.
3164 ftree-parallelize-loops=
3165 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
3166 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
3169 Common Var(flag_tree_phiprop) Init(1) Optimization
3170 Enable hoisting loads from conditional pointers.
3173 Common Var(flag_tree_pre) Optimization
3174 Enable SSA-PRE optimization on trees.
3177 Common Var(flag_tree_partial_pre) Optimization
3178 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
3181 Common Var(flag_tree_pta) Optimization
3182 Perform function-local points-to analysis on trees.
3185 Common Var(flag_tree_reassoc) Init(1) Optimization
3186 Enable reassociation on tree level.
3190 Does nothing. Preserved for backward compatibility.
3193 Common Var(flag_tree_sink) Optimization
3194 Enable SSA code sinking on trees.
3197 Common Var(flag_tree_slsr) Optimization
3198 Perform straight-line strength reduction.
3201 Common Var(flag_tree_sra) Optimization
3202 Perform scalar replacement of aggregates.
3205 Common Var(flag_tree_ter) Optimization
3206 Replace temporary expressions in the SSA->normal pass.
3209 Common Var(flag_tree_live_range_split) Optimization
3210 Perform live range splitting during the SSA->normal pass.
3213 Common Var(flag_tree_vrp) Init(0) Optimization
3214 Perform Value Range Propagation on trees.
3217 Common Var(flag_split_paths) Init(0) Optimization
3218 Split paths leading to loop backedges.
3220 funconstrained-commons
3221 Common Var(flag_unconstrained_commons) Optimization
3222 Assume common declarations may be overridden with ones with a larger
3226 Common Var(flag_unit_at_a_time) Init(1)
3227 Compile whole compilation unit at a time.
3230 Common Var(flag_unreachable_traps) Optimization
3231 Trap on __builtin_unreachable instead of using it for optimization.
3234 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3235 Perform loop unrolling when iteration count is known.
3238 Common Var(flag_unroll_all_loops) Optimization
3239 Perform loop unrolling for all loops.
3241 funroll-completely-grow-size
3242 Undocumented Var(flag_cunroll_grow_size) Optimization
3243 ; Internal undocumented flag, allow size growth during complete unrolling
3245 ; Nonzero means that loop optimizer may assume that the induction variables
3246 ; that control loops do not overflow and that the loops with nontrivial
3247 ; exit condition are not infinite
3248 funsafe-loop-optimizations
3250 Does nothing. Preserved for backward compatibility.
3253 Common Var(flag_associative_math) SetByCombined Optimization
3254 Allow optimization for floating-point arithmetic which may change the
3255 result of the operation due to rounding.
3258 Common Var(flag_reciprocal_math) SetByCombined Optimization
3259 Same as -fassociative-math for expressions which include division.
3261 ; Nonzero means that unsafe floating-point math optimizations are allowed
3262 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
3263 ; are allowed to assume that their arguments and results are "normal"
3264 ; (e.g., nonnegative for SQRT).
3265 funsafe-math-optimizations
3266 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3267 Allow math optimizations that may violate IEEE or ISO standards.
3270 Common Var(flag_unswitch_loops) Optimization
3271 Perform loop unswitching.
3274 Common Var(flag_split_loops) Optimization
3275 Perform loop splitting.
3277 fversion-loops-for-strides
3278 Common Var(flag_version_loops_for_strides) Optimization
3279 Version loops based on whether indices have a stride of one.
3282 Common Var(flag_unwind_tables) Optimization
3283 Just generate unwind tables for exception handling.
3286 Common Driver Negative(fuse-ld=gold)
3287 Use the bfd linker instead of the default linker.
3290 Common Driver Negative(fuse-ld=bfd)
3291 Use the gold linker instead of the default linker.
3294 Common Driver Negative(fuse-ld=lld)
3295 Use the lld LLVM linker instead of the default linker.
3298 Common Driver Negative(fuse-ld=mold)
3299 Use the Modern linker (MOLD) linker instead of the default linker.
3302 Common Undocumented Var(flag_use_linker_plugin)
3304 ; Positive if we should track variables, negative if we should run
3305 ; the var-tracking pass only to discard debug annotations, zero if
3306 ; we're not to run it.
3308 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3309 Perform variable tracking.
3311 ; Positive if we should track variables at assignments, negative if
3312 ; we should run the var-tracking pass only to discard debug
3314 fvar-tracking-assignments
3315 Common Var(flag_var_tracking_assignments) PerFunction
3316 Perform variable tracking by annotating assignments.
3318 ; Nonzero if we should toggle flag_var_tracking_assignments after
3319 ; processing options and computing its default. */
3320 fvar-tracking-assignments-toggle
3321 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3322 Toggle -fvar-tracking-assignments.
3324 ; Positive if we should track uninitialized variables, negative if
3325 ; we should run the var-tracking pass only to discard debug
3327 fvar-tracking-uninit
3328 Common Var(flag_var_tracking_uninit) PerFunction
3329 Perform variable tracking and also tag variables that are uninitialized.
3331 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3333 Common Var(flag_tree_vectorize) Optimization
3334 Enable vectorization on trees.
3336 ftree-vectorizer-verbose=
3337 Common Joined RejectNegative Ignore
3338 Does nothing. Preserved for backward compatibility.
3340 ftree-loop-vectorize
3341 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3342 Enable loop vectorization on trees.
3345 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3346 Enable basic block vectorization (SLP) on trees.
3349 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3350 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the cost model for vectorization.
3353 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3354 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the vectorization cost model for code marked with a simd directive.
3357 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3360 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3363 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3366 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3369 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3372 Common Alias(fvect-cost-model=,dynamic,unlimited)
3373 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
3375 ftree-vect-loop-version
3377 Does nothing. Preserved for backward compatibility.
3380 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3381 Enable copy propagation of scalar-evolution information.
3383 ftrivial-auto-var-init=
3384 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3385 -ftrivial-auto-var-init=[uninitialized|pattern|zero] Add initializations to automatic variables.
3388 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3391 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3394 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3397 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3399 ; -fverbose-asm causes extra commentary information to be produced in
3400 ; the generated assembly code (to make it more readable). This option
3401 ; is generally only of use to those who actually need to read the
3402 ; generated assembly code (perhaps while debugging the compiler itself).
3403 ; -fno-verbose-asm, the default, causes the extra information
3404 ; to not be added and is useful when comparing two assembler files.
3406 Common Var(flag_verbose_asm)
3407 Add extra commentary to assembler output.
3410 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3411 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
3414 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3417 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3420 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3423 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3426 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3429 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3430 Validate vtable pointers before using them.
3433 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3436 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3439 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3442 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3445 Common Var(flag_vtv_counts)
3446 Output vtable verification counters.
3449 Common Var(flag_vtv_debug)
3450 Output vtable verification pointer sets information.
3453 Common Var(flag_value_profile_transformations) Optimization
3454 Use expression value profiles in optimizations.
3457 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3458 Construct webs and split unrelated uses of single variable.
3460 ftree-builtin-call-dce
3461 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3462 Enable conditional dead code elimination for builtin calls.
3465 Common Var(flag_whole_program) Init(0)
3466 Perform whole program optimizations.
3469 Common Var(flag_wrapv_pointer) Optimization
3470 Assume pointer overflow wraps around.
3473 Common Var(flag_wrapv) Optimization
3474 Assume signed arithmetic overflow wraps around.
3476 fzero-initialized-in-bss
3477 Common Var(flag_zero_initialized_in_bss) Init(1)
3478 Put zero initialized data in the bss section.
3480 fzero-call-used-regs=
3481 Common RejectNegative Joined
3482 Clear call-used registers upon function return.
3485 Common Driver RejectNegative JoinedOrMissing
3486 Generate debug information in default format.
3489 Common Driver Var(dwarf2out_as_loc_support)
3490 Assume assembler support for (DWARF2+) .loc directives.
3493 Common Driver Var(dwarf2out_as_locview_support)
3494 Assume assembler support for view in (DWARF2+) .loc directives.
3497 Common Driver JoinedOrMissing
3498 Generate debug information in CodeView format.
3501 Common Driver WarnRemoved
3502 Does nothing. Preserved for backward compatibility.
3505 Common Driver WarnRemoved
3506 Does nothing. Preserved for backward compatibility.
3509 Common Driver WarnRemoved
3510 Does nothing. Preserved for backward compatibility.
3513 Common Driver WarnRemoved
3514 Does nothing. Preserved for backward compatibility.
3517 Common Driver Var(debug_column_info,1) Init(1)
3518 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3520 ; The CTF generation process feeds off DWARF dies. This option implicitly
3521 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3523 Common Driver RejectNegative JoinedOrMissing
3524 Generate CTF debug information at default level.
3527 Common Driver RejectNegative JoinedOrMissing
3528 Generate BTF debug information at default level.
3531 Common Driver JoinedOrMissing RejectNegative
3532 Generate debug information in default version of DWARF format.
3535 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT) RejectNegative
3536 Generate debug information in DWARF v2 (or later) format.
3539 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3540 Use 32-bit DWARF format when emitting DWARF debug information.
3543 Common Driver Var(dwarf_offset_size,8) RejectNegative
3544 Use 64-bit DWARF format when emitting DWARF debug information.
3547 Common Driver JoinedOrMissing RejectNegative
3548 Generate debug information in default extended format.
3551 Common Driver Var(debug_inline_points)
3552 Generate extended entry point information for inlined functions.
3554 ginternal-reset-location-views
3555 Common Driver Var(debug_internal_reset_location_views) Init(2)
3556 Compute locview reset points based on insn length estimates.
3559 RejectNegative Joined Undocumented
3560 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3563 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3564 Don't generate DWARF pubnames and pubtypes sections.
3567 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3568 Generate DWARF pubnames and pubtypes sections.
3571 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3572 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3574 grecord-gcc-switches
3575 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3576 Record gcc command line switches in DWARF DW_AT_producer.
3579 Common Driver Var(dwarf_split_debug_info) Init(0)
3580 Generate debug information in separate .dwo files.
3583 Common Driver WarnRemoved
3584 Does nothing. Preserved for backward compatibility.
3587 Common Driver WarnRemoved
3588 Does nothing. Preserved for backward compatibility.
3590 gstatement-frontiers
3591 Common Driver Var(debug_nonbind_markers_p) PerFunction
3592 Emit progressive recommended breakpoint locations.
3595 Common Driver Var(dwarf_strict) Init(0)
3596 Don't emit DWARF additions beyond selected version.
3599 Common Driver Var(flag_describe_dies) Init(0)
3600 Add description attributes to some DWARF DIEs that have no name attribute.
3603 Common Driver Var(flag_gtoggle)
3604 Toggle debug information generation.
3606 gvariable-location-views
3607 Common Driver Var(debug_variable_location_views, 1)
3608 Augment variable location lists with progressive views.
3610 gvariable-location-views=incompat5
3611 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3614 Common Driver JoinedOrMissing RejectNegative
3615 Generate debug information in VMS format.
3618 Common Driver WarnRemoved
3619 Does nothing. Preserved for backward compatibility.
3622 Common Driver JoinedOrMissing WarnRemoved
3623 Does nothing. Preserved for backward compatibility.
3626 Name(compressed_debug_sections) Type(int)
3628 ; Since -gz= is completely handled in specs, the values aren't used and we
3629 ; assign arbitrary constants.
3631 Enum(compressed_debug_sections) String(none) Value(0)
3634 Enum(compressed_debug_sections) String(zlib) Value(1)
3637 Enum(compressed_debug_sections) String(zstd) Value(2)
3640 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3644 Generate compressed debug sections.
3647 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3648 -gz=<format> Generate compressed debug sections in format <format>.
3651 Driver Joined Separate
3654 Common Joined Var(plugindir_string) Init(0)
3655 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3658 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3659 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3662 Driver Joined Separate
3667 no-canonical-prefixes
3686 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3687 -o <file> Place output into <file>.
3690 Common Var(profile_flag)
3691 Enable function profiling.
3694 Driver Var(pass_exit_codes)
3697 Common Alias(Wpedantic)
3700 Common Var(flag_pedantic_errors)
3701 Like -pedantic but issue them as errors.
3707 Driver Var(use_pipes)
3710 Driver JoinedOrMissing Var(print_file_name)
3712 print-libgcc-file-name
3715 print-multi-directory
3716 Driver Var(print_multi_directory)
3719 Driver Var(print_multi_lib)
3721 print-multi-os-directory
3722 Driver Var(print_multi_os_directory)
3725 Driver Var(print_multiarch)
3728 Driver JoinedOrMissing Var(print_prog_name)
3731 Driver Var(print_search_dirs)
3734 Driver Var(print_sysroot)
3736 print-sysroot-headers-suffix
3737 Driver Var(print_sysroot_headers_suffix)
3740 Common Var(quiet_flag) RejectDriver
3741 Do not display functions compiled or elapsed time.
3759 Driver Var(report_times)
3762 Driver JoinedOrMissing
3765 Driver Joined Separate
3769 ; C option, but driver must not handle as "-u ndef".
3772 Common Driver Var(verbose_flag)
3773 Enable verbose output.
3776 Common Var(version_flag) RejectDriver
3777 Display the compiler's version.
3780 Common Var(inhibit_warnings)
3784 Driver Separate Var(wrapper_string)
3787 Driver Joined Separate
3790 Driver RejectNegative Negative(static-pie)
3791 Create a shared library.
3797 Driver Separate Alias(specs=)
3810 ; Documented for Fortran, but always accepted by driver.
3814 ; Documented for Modula-2, but always accepted by driver.
3818 ; Documented for D, but always accepted by driver.
3822 ; Documented for Fortran, but always accepted by driver.
3829 ; Documented for Go, but always accepted by driver.
3850 Driver RejectNegative Negative(shared)
3851 Don't create a dynamically linked position independent executable.
3854 Driver RejectNegative Negative(no-pie)
3855 Create a dynamically linked position independent executable.
3858 Driver RejectNegative Negative(pie)
3859 Create a static position independent executable.
3862 Driver Joined Separate
3865 Common Var(flag_ipa_ra) Optimization
3866 Use caller save register across calls if possible.
3868 ; This comment is to ensure we retain the blank line above.