1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2019 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 incrmeental 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
62 ; Language specific warning pass for unused results.
64 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 two are really VEC(char_p,heap) *.
89 void *flag_instrument_functions_exclude_functions
92 void *flag_instrument_functions_exclude_files
94 ; Generic structs (e.g. templates not explicitly specialized)
95 ; may not have a compilation unit associated with them, and so
96 ; may need to be treated differently from ordinary structs.
98 ; Structs only handled by reference (indirectly), will also usually
99 ; not need as much debugging information.
102 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
105 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
107 ; True if we should exit after parsing options.
109 bool exit_after_options
111 ; Type(s) of debugging information we are producing (if any). See
112 ; flag-types.h for the definitions of the different possible types of
113 ; debugging information.
115 enum debug_info_type write_symbols = NO_DEBUG
117 ; Level of debugging information we are producing. See flag-types.h
118 ; for the definitions of the different possible levels.
120 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
122 ; Nonzero means use GNU-only extensions in the generated symbolic
123 ; debugging information. Currently, this only has an effect when
124 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
126 bool use_gnu_debug_info_extensions
128 ; Original value of maximum field alignment in bytes, specified via
129 ; -fpack-struct=<value>.
131 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
133 ; Type of stack check.
135 enum stack_check_type flag_stack_check = NO_STACK_CHECK
137 ; True if stack usage information needs to be computed.
139 bool flag_stack_usage_info = false
141 ; -dA causes debug commentary information to be produced in
142 ; the generated assembly code (to make it more readable). This option
143 ; is generally only of use to those who actually need to read the
144 ; generated assembly code (perhaps while debugging the compiler itself).
145 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
146 ; to be a catchall for printing debug information in the assembler file.
150 ; How many NOP insns to place at each function entry by default
152 HOST_WIDE_INT function_entry_patch_area_size
154 ; And how far the real asm entry point is into this area
156 HOST_WIDE_INT function_entry_patch_area_start
158 ; Balance between GNAT encodings and standard DWARF to emit.
160 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
162 ; -dP causes the rtl to be emitted as a comment in assembly.
164 int flag_dump_rtl_in_asm
166 ; Whether -da was passed (used only in handle_common_deferred_options).
168 bool flag_dump_all_passed
170 ; Other flags saying which kinds of debugging dump have been requested.
173 int rtl_dump_and_exit
176 int flag_print_asm_name
178 ; Name of top-level original source file (what was input to cpp).
179 ; This comes from the #-command at the beginning of the actual input.
180 ; If there isn't any there, then this is the cc1 input file name.
182 const char *main_input_filename
184 ; Pointer to base name in main_input_filename, with directories and a
185 ; single final extension removed, and the length of this base
189 const char *main_input_basename
192 int main_input_baselength
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_UNREACHABLE | SANITIZE_RETURN)
220 ; What the coverage sanitizers should instrument
222 unsigned int flag_sanitize_coverage
224 ; Flag whether a prefix has been added to dump_base_name
226 bool dump_base_name_prefixed = false
228 ; Flag whether HSA generation has been explicitely disabled
230 bool flag_disable_hsa = false
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 Common Separate Alias(dumpbase)
261 Common Separate Alias(dumpdir)
264 Driver Separate Alias(e)
267 Driver Joined Alias(e)
270 Common Warning Alias(Wextra)
273 Driver Separate Alias(Xassembler)
276 Driver JoinedOrMissing Alias(Xassembler)
279 Driver Separate Alias(Xlinker)
282 Driver JoinedOrMissing Alias(Xlinker)
285 Driver Separate Alias(u)
288 Driver Joined Alias(u)
291 Common Driver Var(help_flag)
292 Display this information.
295 Common Driver Report Joined
296 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
299 Driver Separate Alias(x)
302 Driver Joined Alias(x)
305 Driver Separate Alias(L)
308 Driver Joined Alias(L)
310 -no-canonical-prefixes
311 Driver Alias(no-canonical-prefixes)
313 -no-standard-libraries
314 Driver Alias(nostdlib)
317 Driver Var(no_sysroot_suffix)
326 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
329 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
332 Driver Alias(pass-exit-codes)
335 Common Alias(Wpedantic)
338 Common Alias(pedantic-errors)
344 Driver Alias(static-pie)
350 Driver Separate Alias(B)
353 Driver JoinedOrMissing Alias(B)
359 Driver Separate Alias(print-file-name=)
362 Driver JoinedOrMissing Alias(print-file-name=)
364 -print-libgcc-file-name
365 Driver Alias(print-libgcc-file-name)
367 -print-multi-directory
368 Driver Alias(print-multi-directory)
371 Driver Alias(print-multi-lib)
373 -print-multi-os-directory
374 Driver Alias(print-multi-os-directory)
377 Driver Alias(print-multiarch)
380 Driver Separate Alias(print-prog-name=)
383 Driver JoinedOrMissing Alias(print-prog-name=)
386 Driver Alias(print-search-dirs)
389 Driver Alias(print-sysroot)
391 -print-sysroot-headers-suffix
392 Driver Alias(print-sysroot-headers-suffix)
398 Driver Alias(save-temps)
404 Driver Separate Alias(specs=)
407 Driver Joined Alias(specs=)
413 Driver Alias(symbolic)
417 Alias for --help=target.
425 ;; The driver used to convert options such as --help into forms such
426 ;; as -fhelp; the following four entries are for compatibility with
427 ;; any direct uses of those (undocumented) -f forms
429 Common Driver Alias(-help)
432 Common Driver Joined Alias(-help=)
435 Common Driver Alias(-target-help)
438 Common Driver Alias(-version)
442 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
445 Common Joined Alias(-param)
448 Driver Separate Alias(-sysroot=)
451 Driver JoinedOrMissing
457 Driver Joined Separate
463 Driver Joined Separate
469 Common JoinedOrMissing Optimization
470 -O<number> Set optimization level to <number>.
474 Optimize for space rather than speed.
478 Optimize for speed disregarding exact standards compliance.
482 Optimize for debugging experience rather than speed or size.
494 Driver Joined Separate
500 Driver Joined Separate
521 Common RejectNegative Warning Alias(Wextra)
522 This switch is deprecated; use -Wextra instead.
525 Driver JoinedOrMissing RejectNegative
528 Driver JoinedOrMissing RejectNegative
531 Driver JoinedOrMissing RejectNegative
534 Common Var(warn_aggregate_return) Warning
535 Warn about returning structures, unions or arrays.
537 Waggressive-loop-optimizations
538 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
539 Warn if a loop with constant number of iterations triggers undefined behavior.
542 Common Var(warn_array_bounds) Warning
543 Warn if an array is accessed out of bounds.
546 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
547 Warn if an array is accessed out of bounds.
550 Common Var(warn_attributes) Init(1) Warning
551 Warn about inappropriate attribute usage.
554 Common Alias(Wattribute_alias=, 1, 0) Warning
555 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
558 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
559 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
562 Common Var(warn_cannot_profile) Init(1) Warning
563 Warn when profiling instrumentation was requested, but could not be applied to
567 Common Var(warn_cast_align) Warning
568 Warn about pointer casts which increase alignment.
571 Common Var(warn_cast_align,2) Warning
572 Warn about pointer casts which increase alignment.
575 Common Var(warn_cpp) Init(1) Warning
576 Warn when a #warning directive is encountered.
579 Common Var(warn_attribute_warning) Init(1) Warning
580 Warn about uses of __attribute__((warning)) declarations.
583 Common Var(warn_deprecated) Init(1) Warning
584 Warn if a deprecated compiler feature, class, method, or field is used.
586 Wdeprecated-declarations
587 Common Var(warn_deprecated_decl) Init(1) Warning
588 Warn about uses of __attribute__((deprecated)) declarations.
590 Wdisabled-optimization
591 Common Var(warn_disabled_optimization) Warning
592 Warn when an optimization pass is disabled.
595 Common Var(warnings_are_errors)
596 Treat all warnings as errors.
600 Treat specified warning as error.
603 Common Var(extra_warnings) Warning
604 Print extra (possibly unwanted) warnings.
607 Common Var(flag_fatal_errors)
608 Exit on the first error occurred.
611 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
612 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
615 Common Var(warn_free_nonheap_object) Init(1) Warning
616 Warn when attempting to free a non-heap object.
619 Common Var(warn_hsa) Init(1) Warning
620 Warn when a function cannot be expanded to HSAIL.
622 Wimplicit-fallthrough
623 Common Alias(Wimplicit-fallthrough=,3,0) Warning
625 Wimplicit-fallthrough=
626 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
627 Warn when a switch case falls through.
630 Common Var(warn_inline) Warning
631 Warn when an inlined function cannot be inlined.
633 Winvalid-memory-model
634 Common Var(warn_invalid_memory_model) Init(1) Warning
635 Warn when an atomic memory model parameter is known to be outside the valid range.
638 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
641 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
642 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
645 Var(warn_nonnull_compare) Warning
646 Warn if comparing pointer parameter with nonnull attribute with NULL.
649 Common Var(warn_null_dereference) Warning
650 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
652 Wunsafe-loop-optimizations
653 Common Ignore Warning
654 Does nothing. Preserved for backward compatibility.
657 Common Warning Alias(Wsuggest-attribute=noreturn)
660 Common Var(warn_odr_violations) Init(1) Warning
661 Warn about some C++ One Definition Rule violations during link time optimization.
664 Common Var(warn_overflow) Init(1) Warning
665 Warn about overflow in arithmetic expressions.
668 Common Var(warn_lto_type_mismatch) Init(1) Warning
669 During link time optimization warn about mismatched types of global declarations.
672 Common Var(warn_packed) Warning
673 Warn when the packed attribute has no effect on struct layout.
676 Common Var(warn_padded) Warning
677 Warn when padding is required to align structure members.
680 Common Var(pedantic) Init(0) Warning
681 Issue warnings needed for strict compliance to the standard.
684 Common Var(warn_return_local_addr) Init(1) Warning
685 Warn about returning a pointer/reference to a local or temporary variable.
688 Common Var(warn_shadow) Warning
689 Warn when one variable shadows another. Same as -Wshadow=global.
692 Common Warning Alias(Wshadow)
693 Warn when one variable shadows another (globally).
696 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
697 Warn when one local variable shadows another local variable or parameter.
700 Common Warning Undocumented Alias(Wshadow=local)
702 Wshadow=compatible-local
703 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
704 Warn when one local variable shadows another local variable or parameter of compatible type.
706 Wshadow-compatible-local
707 Common Warning Undocumented Alias(Wshadow=compatible-local)
710 Common Var(warn_stack_protect) Warning
711 Warn when not issuing stack smashing protection for some reason.
714 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
715 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
719 Warn about code which might break strict aliasing rules.
722 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
723 Warn about code which might break strict aliasing rules.
727 Warn about optimizations that assume that signed overflow is undefined.
730 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
731 Warn about optimizations that assume that signed overflow is undefined.
733 Wsuggest-attribute=cold
734 Common Var(warn_suggest_attribute_cold) Warning
735 Warn about functions which might be candidates for __attribute__((cold)).
737 Wsuggest-attribute=const
738 Common Var(warn_suggest_attribute_const) Warning
739 Warn about functions which might be candidates for __attribute__((const)).
741 Wsuggest-attribute=pure
742 Common Var(warn_suggest_attribute_pure) Warning
743 Warn about functions which might be candidates for __attribute__((pure)).
745 Wsuggest-attribute=noreturn
746 Common Var(warn_suggest_attribute_noreturn) Warning
747 Warn about functions which might be candidates for __attribute__((noreturn)).
749 Wsuggest-attribute=malloc
750 Common Var(warn_suggest_attribute_malloc) Warning
751 Warn about functions which might be candidates for __attribute__((malloc)).
754 Common Var(warn_suggest_final_types) Warning
755 Warn about C++ polymorphic types where adding final keyword would improve code quality.
757 Wsuggest-final-methods
758 Common Var(warn_suggest_final_methods) Warning
759 Warn about C++ virtual methods where adding final keyword would improve code quality.
762 Common Var(warn_switch_unreachable) Warning Init(1)
763 Warn about statements between switch's controlling expression and the first
767 Common Var(warn_system_headers) Warning
768 Do not suppress warnings from system headers.
771 Common Var(warn_trampolines) Warning
772 Warn whenever a trampoline is generated.
775 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
776 Warn if a comparison is always true or always false due to the limited range of the data type.
779 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
780 Warn about uninitialized automatic variables.
783 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
784 Warn about maybe uninitialized automatic variables.
787 Common Ignore Warning
788 Does nothing. Preserved for backward compatibility.
791 Common Var(warn_unused) Init(0) Warning
792 Enable all -Wunused- warnings.
794 Wunused-but-set-parameter
795 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
796 Warn when a function parameter is only set, otherwise unused.
798 Wunused-but-set-variable
799 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
800 Warn when a variable is only set, otherwise unused.
803 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
804 Warn when a function is unused.
807 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
808 Warn when a label is unused.
811 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
812 Warn when a function parameter is unused.
815 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
816 Warn when an expression value is unused.
819 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
820 Warn when a variable is unused.
823 Common Var(warn_coverage_mismatch) Init(1) Warning
824 Warn in case profiles in -fprofile-use do not match.
827 Common Var(warn_missing_profile) Init(1) Warning
828 Warn in case profiles in -fprofile-use do not exist.
830 Wvector-operation-performance
831 Common Var(warn_vector_operation_performance) Warning
832 Warn when a vector operation is compiled outside the SIMD.
847 Common Separate Var(aux_info_file_name)
848 -aux-info <file> Emit declaration information into <file>.
851 Common Joined Alias(aux-info)
854 Common Separate RejectDriver Var(aux_base_name)
857 Common Separate RejectDriver
867 -d<letters> Enable dumps from specific passes of the compiler.
870 Common Separate Var(dump_base_name)
871 -dumpbase <file> Set the file basename to be used for dumps.
874 Common Separate Var(dump_dir_name)
875 -dumpdir <dir> Set the directory name to be used for dumps.
890 Driver Joined Separate
892 ; This option has historically been passed down to the linker by an
893 ; accident of a %{e*} spec, so ensure it continues to be passed down
894 ; as a single option. The supported option for this purpose is
895 ; -rdynamic. See PR 47390.
899 ; The version of the C++ ABI in use. The following values are allowed:
901 ; 0: The version of the ABI believed most conformant with the C++ ABI
902 ; specification. This ABI may change as bugs are discovered and fixed.
903 ; Therefore, 0 will not necessarily indicate the same ABI in different
906 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
908 ; 2: The version of the ABI first used in G++ 3.4, and the default
911 ; 3: The version of the ABI that fixes the missing underscore
912 ; in template non-type arguments of pointer type.
914 ; 4: The version of the ABI that introduces unambiguous mangling of
915 ; vector types. First selectable in G++ 4.5.
917 ; 5: The version of the ABI that ignores attribute const/noreturn
918 ; in function pointer mangling, and corrects mangling of decltype and
919 ; function parameters used in other parameters and the return type.
920 ; First selectable in G++ 4.6.
922 ; 6: The version of the ABI that doesn't promote scoped enums to int and
923 ; changes the mangling of template argument packs, const/static_cast,
924 ; prefix ++ and --, and a class scope function used as a template
926 ; First selectable in G++ 4.7.
928 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
929 ; corrects the mangling of lambdas in default argument scope.
930 ; First selectable in G++ 4.8.
932 ; 8: The version of the ABI that corrects the substitution behavior of
933 ; function types with function-cv-qualifiers.
934 ; First selectable in G++ 4.9 and default in G++ 5.
936 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
937 ; First selectable and default in G++ 5.2.
939 ; 10: The version of the ABI that mangles attributes that affect type
940 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
941 ; Default in G++ 6 (set in c_common_post_options).
943 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
944 ; and introduces new inheriting constructor handling.
947 ; 12: Corrects the calling convention for classes with only deleted copy/move
948 ; constructors and changes passing/returning of empty records.
949 ; Default in G++ 8.1.
951 ; 13: Fixes the accidental change in 12 to the calling convention for classes
952 ; with deleted copy constructor and trivial move constructor.
953 ; Default in G++ 8.2.
955 ; Additional positive integers will be assigned as new versions of
956 ; the ABI become the default version of the ABI.
958 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
959 The version of the C++ ABI in use.
961 faggressive-loop-optimizations
962 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
963 Aggressively optimize loops using language constraints.
966 Common Report Var(flag_align_functions) Optimization
967 Align the start of functions.
970 Common RejectNegative Joined Var(str_align_functions) Optimization
972 flimit-function-alignment
973 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
976 Common Report Var(flag_align_jumps) Optimization
977 Align labels which are only reached by jumping.
980 Common RejectNegative Joined Var(str_align_jumps) Optimization
983 Common Report Var(flag_align_labels) Optimization
987 Common RejectNegative Joined Var(str_align_labels) Optimization
990 Common Report Var(flag_align_loops) Optimization
991 Align the start of loops.
994 Common RejectNegative Joined Var(str_align_loops) Optimization
998 Does nothing. Preserved for backward compatibility.
1002 Does nothing. Preserved for backward compatibility.
1004 fargument-noalias-global
1006 Does nothing. Preserved for backward compatibility.
1008 fargument-noalias-anything
1010 Does nothing. Preserved for backward compatibility.
1013 Common Driver Report Joined
1014 Select what to sanitize.
1017 Common Report Joined
1018 Select type of coverage sanitization.
1020 fasan-shadow-offset=
1021 Common Joined RejectNegative Var(common_deferred_options) Defer
1022 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1025 Common Joined RejectNegative Var(common_deferred_options) Defer
1026 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1027 in user-defined sections.
1030 Common Report Joined
1031 After diagnosing undefined behavior attempt to continue execution.
1035 This switch is deprecated; use -fsanitize-recover= instead.
1037 fsanitize-address-use-after-scope
1038 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1040 fsanitize-undefined-trap-on-error
1041 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1042 Use trap instead of a library function for undefined behavior sanitization.
1044 fasynchronous-unwind-tables
1045 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1046 Generate unwind tables that are exact at each instruction boundary.
1049 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1050 Generate auto-inc/dec instructions.
1053 Common Report Var(flag_auto_profile)
1054 Use sample profile information for call graph node weights. The default
1055 profile file is fbdata.afdo in 'pwd'.
1058 Common Joined RejectNegative Var(auto_profile_file)
1059 Use sample profile information for call graph node weights. The profile
1060 file is specified in the argument.
1062 ; -fcheck-bounds causes gcc to generate array bounds checks.
1063 ; For C, C++ and ObjC: defaults off.
1064 ; For Java: defaults to on.
1065 ; For Fortran: defaults to off.
1067 Common Report Var(flag_bounds_check)
1068 Generate code to check bounds before indexing arrays.
1071 Common Report Var(flag_branch_on_count_reg) Optimization
1072 Replace add, compare, branch with branch on count register.
1074 fbranch-probabilities
1075 Common Report Var(flag_branch_probabilities) Optimization
1076 Use profiling information for branch probabilities.
1078 fbranch-target-load-optimize
1079 Common Report Var(flag_branch_target_load_optimize) Optimization
1080 Perform branch target load optimization before prologue / epilogue threading.
1082 fbranch-target-load-optimize2
1083 Common Report Var(flag_branch_target_load_optimize2) Optimization
1084 Perform branch target load optimization after prologue / epilogue threading.
1087 Common Report Var(flag_btr_bb_exclusive) Optimization
1088 Restrict target load migration not to re-use registers in any basic block.
1091 Common Joined RejectNegative Var(common_deferred_options) Defer
1092 -fcall-saved-<register> Mark <register> as being preserved across functions.
1095 Common Joined RejectNegative Var(common_deferred_options) Defer
1096 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1098 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1099 ; be saved across function calls, if that produces overall better code.
1100 ; Optional now, so people can test it.
1102 Common Report Var(flag_caller_saves) Optimization
1103 Save registers around function calls.
1107 This switch is deprecated; do not use.
1110 Common Var(flag_check_new)
1111 Check the return value of new in C++.
1114 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1115 Perform internal consistency checkings.
1118 Common Joined RejectNegative UInteger Var(flag_checking)
1119 Perform internal consistency checkings.
1122 Common Report Var(flag_code_hoisting) Optimization
1123 Enable code hoisting.
1125 fcombine-stack-adjustments
1126 Common Report Var(flag_combine_stack_adjustments) Optimization
1127 Looks for opportunities to reduce stack adjustments and stack references.
1130 Common Report Var(flag_no_common,0)
1131 Do not put uninitialized globals in the common section.
1135 ; Converted by the driver to -fcompare-debug= options.
1138 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1139 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1141 fcompare-debug-second
1142 Common Driver RejectNegative Var(flag_compare_debug)
1143 Run only the second compilation of -fcompare-debug.
1146 Common Report Var(flag_compare_elim_after_reload) Optimization
1147 Perform comparison elimination after register allocation has finished.
1150 Common Var(flag_conserve_stack) Optimization
1151 Do not perform optimizations increasing noticeably stack usage.
1154 Common Report Var(flag_cprop_registers) Optimization
1155 Perform a register copy-propagation optimization pass.
1158 Common Report Var(flag_crossjumping) Optimization
1159 Perform cross-jumping optimization.
1162 Common Report Var(flag_cse_follow_jumps) Optimization
1163 When running CSE, follow jumps to their targets.
1167 Does nothing. Preserved for backward compatibility.
1170 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1171 Omit range reduction step when performing complex division.
1174 Common Report Var(flag_cx_fortran_rules) Optimization
1175 Complex multiplication and division follow Fortran rules.
1178 Common Report Var(flag_data_sections)
1179 Place data items into their own section.
1182 Common Report Var(common_deferred_options) Defer
1183 List all available debugging counters with their limits and counts.
1186 Common RejectNegative Joined Var(common_deferred_options) Defer
1187 -fdbg-cnt=<counter>[:<lower_limit>]:<upper_limit>[,<counter>:...] Set the debug counter limit.
1190 Common Joined RejectNegative Var(common_deferred_options) Defer
1191 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1194 Common Joined RejectNegative Var(common_deferred_options) Defer
1195 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1197 fdebug-types-section
1198 Common Report Var(flag_debug_types_section) Init(0)
1199 Output .debug_types section when using DWARF v4 debuginfo.
1201 ; Nonzero for -fdefer-pop: don't pop args after each function call
1202 ; instead save them up to pop many calls' args with one insns.
1204 Common Report Var(flag_defer_pop) Optimization
1205 Defer popping functions args from stack until later.
1208 Common Report Var(flag_delayed_branch) Optimization
1209 Attempt to fill delay slots of branch instructions.
1211 fdelete-dead-exceptions
1212 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1213 Delete dead instructions that may throw exceptions.
1215 fdelete-null-pointer-checks
1216 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1217 Delete useless null pointer checks.
1219 fdevirtualize-at-ltrans
1220 Common Report Var(flag_ltrans_devirtualize)
1221 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1223 fdevirtualize-speculatively
1224 Common Report Var(flag_devirtualize_speculatively) Optimization
1225 Perform speculative devirtualization.
1228 Common Report Var(flag_devirtualize) Optimization
1229 Try to convert virtual calls to direct ones.
1231 fdiagnostics-show-location=
1232 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1233 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1235 ; Required for these enum values.
1240 Name(diagnostic_prefixing_rule) Type(int)
1243 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1246 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1248 fdiagnostics-show-caret
1249 Common Var(flag_diagnostics_show_caret) Init(1)
1250 Show the source line with a caret indicating the column.
1252 fdiagnostics-show-labels
1253 Common Var(flag_diagnostics_show_labels) Init(1)
1254 Show labels annotating ranges of source code when showing source.
1256 fdiagnostics-show-line-numbers
1257 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1258 Show line numbers in the left margin when showing source.
1261 Common Alias(fdiagnostics-color=,always,never)
1265 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1266 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1268 ; Required for these enum values.
1273 Name(diagnostic_color_rule) Type(int)
1276 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1279 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1282 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1284 fdiagnostics-format=
1285 Common Joined RejectNegative Enum(diagnostics_output_format)
1286 -fdiagnostics-format=[text|json] Select output format.
1288 ; Required for these enum values.
1293 Name(diagnostics_output_format) Type(int)
1296 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1299 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1301 fdiagnostics-parseable-fixits
1302 Common Var(flag_diagnostics_parseable_fixits)
1303 Print fix-it hints in machine-readable form.
1305 fdiagnostics-generate-patch
1306 Common Var(flag_diagnostics_generate_patch)
1307 Print fix-it hints to stderr in unified diff format.
1309 fdiagnostics-show-option
1310 Common Var(flag_diagnostics_show_option) Init(1)
1311 Amend appropriate diagnostic messages with the command line option that controls them.
1313 fdiagnostics-minimum-margin-width=
1314 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1315 Set minimum width of left margin of source code when showing source.
1318 Common Joined RejectNegative Var(common_deferred_options) Defer
1319 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1322 Common Joined RejectNegative Var(common_deferred_options) Defer
1323 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1326 Common Joined RejectNegative Var(common_deferred_options) Defer
1327 -fdump-<type> Dump various compiler internals to a file.
1330 Driver RejectNegative
1333 Common RejectNegative Joined Var(flag_dump_final_insns)
1334 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1337 Common RejectNegative Joined Var(flag_dump_go_spec)
1338 -fdump-go-spec=filename Write all declarations to file as Go code.
1341 Common Report Var(flag_dump_noaddr)
1342 Suppress output of addresses in debugging dumps.
1345 Common Driver Var(flag_report_bug)
1346 Collect and dump debug information into temporary file if ICE in C/C++
1349 fdump-internal-locations
1350 Common Var(flag_dump_locations) Init(0)
1351 Dump detailed information on GCC's internal representation of source code locations.
1354 Common Var(flag_dump_passes) Init(0)
1355 Dump optimization passes.
1358 Common Report Var(flag_dump_unnumbered)
1359 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1361 fdump-unnumbered-links
1362 Common Report Var(flag_dump_unnumbered_links)
1363 Suppress output of previous and next insn numbers in debugging dumps.
1366 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1367 Enable CFI tables via GAS assembler directives.
1370 Common Report Var(flag_early_inlining) Init(1) Optimization
1371 Perform early inlining.
1373 feliminate-dwarf2-dups
1375 Does nothing. Preserved for backward compatibility.
1378 Common Report Var(flag_ipa_sra) Init(0) Optimization
1379 Perform interprocedural reduction of aggregates.
1381 feliminate-unused-debug-symbols
1382 Common Report Var(flag_debug_only_used_symbols)
1383 Perform unused symbol elimination in debug info.
1385 feliminate-unused-debug-types
1386 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1387 Perform unused type elimination in debug info.
1389 femit-class-debug-always
1390 Common Report Var(flag_emit_class_debug_always) Init(0)
1391 Do not suppress C++ class debug information.
1394 Common Report Var(flag_exceptions) Optimization
1395 Enable exception handling.
1397 fexpensive-optimizations
1398 Common Report Var(flag_expensive_optimizations) Optimization
1399 Perform a number of minor, expensive optimizations.
1402 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1403 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1406 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1409 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1412 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1414 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1415 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1416 fpermitted-flt-eval-methods=
1417 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1418 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1421 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)
1424 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1427 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1433 Common Var(flag_fat_lto_objects)
1434 Output lto objects containing both the intermediate language and binary output.
1437 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1438 Assume no NaNs or infinities are generated.
1441 Common Joined RejectNegative Var(common_deferred_options) Defer
1442 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1445 Common Report Var(flag_float_store) Optimization
1446 Don't allocate floats and doubles in extended-precision registers.
1450 Does nothing. Preserved for backward compatibility.
1453 Common Report Var(flag_forward_propagate) Optimization
1454 Perform a forward propagation pass on RTL.
1457 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1458 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1461 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1464 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1466 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1468 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1471 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1473 ffp-int-builtin-inexact
1474 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1475 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1477 ; Nonzero means don't put addresses of constant functions in registers.
1478 ; Used for compiling the Unix kernel, where strange substitutions are
1479 ; done on the assembly output.
1481 Common Report Var(flag_no_function_cse,0) Optimization
1482 Allow function addresses to be held in registers.
1485 Common Report Var(flag_function_sections)
1486 Place each function into its own section.
1489 Common Report Var(flag_gcse) Optimization
1490 Perform global common subexpression elimination.
1493 Common Report Var(flag_gcse_lm) Init(1) Optimization
1494 Perform enhanced load motion during global common subexpression elimination.
1497 Common Report Var(flag_gcse_sm) Init(0) Optimization
1498 Perform store motion after global common subexpression elimination.
1501 Common Report Var(flag_gcse_las) Init(0) Optimization
1502 Perform redundant load after store elimination in global common subexpression
1506 Common Report Var(flag_gcse_after_reload) Optimization
1507 Perform global common subexpression elimination after register allocation has
1511 Name(dwarf_gnat_encodings) Type(int)
1514 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1517 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1520 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1523 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1524 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1526 ; This option is not documented yet as its semantics will change.
1528 Common Report Var(flag_graphite) Optimization
1529 Enable in and out of Graphite representation.
1532 Common Report Var(flag_graphite_identity) Optimization
1533 Enable Graphite Identity transformation.
1535 fhoist-adjacent-loads
1536 Common Report Var(flag_hoist_adjacent_loads) Optimization
1537 Enable hoisting adjacent loads to encourage generating conditional move
1541 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1542 ; Always keep a pointer to a live memory block
1544 floop-parallelize-all
1545 Common Report Var(flag_loop_parallelize_all) Optimization
1546 Mark all loops as parallel.
1549 Common Alias(floop-nest-optimize)
1550 Enable loop nest transforms. Same as -floop-nest-optimize.
1553 Common Report Var(flag_loop_interchange) Optimization
1554 Enable loop interchange on trees.
1557 Common Alias(floop-nest-optimize)
1558 Enable loop nest transforms. Same as -floop-nest-optimize.
1560 floop-unroll-and-jam
1561 Common Report Var(flag_unroll_jam) Optimization
1562 Perform unroll-and-jam on loops.
1565 Common Report Var(flag_tm)
1566 Enable support for GNU transactional memory.
1569 Common Report Var(flag_gnu_unique) Init(1)
1570 Use STB_GNU_UNIQUE if supported by the assembler.
1574 Does nothing. Preserved for backward compatibility.
1577 Common Report Var(flag_loop_nest_optimize) Optimization
1578 Enable the loop nest optimizer.
1580 fstrict-volatile-bitfields
1581 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1582 Force bitfield accesses to match their type width.
1585 Common Report Var(flag_store_merging) Optimization
1586 Merge adjacent stores.
1588 fguess-branch-probability
1589 Common Report Var(flag_guess_branch_prob) Optimization
1590 Enable guessing of branch probabilities.
1592 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1593 ; Generate position-independent code for executables if possible
1594 ; On SVR4 targets, it also controls whether or not to emit a
1595 ; string identifying the compiler.
1597 Common Report Var(flag_no_ident,0)
1598 Process #ident directives.
1601 Common Report Var(flag_if_conversion) Optimization
1602 Perform conversion of conditional jumps to branchless equivalents.
1605 Common Report Var(flag_if_conversion2) Optimization
1606 Perform conversion of conditional jumps to conditional execution.
1609 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1610 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1613 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1616 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1619 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1622 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1624 ftree-loop-if-convert
1625 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1626 Convert conditional jumps in innermost loops to branchless equivalents.
1628 ftree-loop-if-convert-stores
1630 Does nothing. Preserved for backward compatibility.
1632 ; -finhibit-size-directive inhibits output of .size for ELF.
1633 ; This is used only for compiling crtstuff.c,
1634 ; and it may be extended to other effects
1635 ; needed for crtstuff.c on other systems.
1636 finhibit-size-directive
1637 Common Report Var(flag_inhibit_size_directive)
1638 Do not generate .size directives.
1641 Common Report Var(flag_indirect_inlining) Optimization
1642 Perform indirect inlining.
1644 ; General flag to enable inlining. Specifying -fno-inline will disable
1645 ; all inlining apart from always-inline functions.
1647 Common Report Var(flag_no_inline,0) Init(0) Optimization
1648 Enable inlining of function declared \"inline\", disabling disables all inlining.
1650 finline-small-functions
1651 Common Report Var(flag_inline_small_functions) Optimization
1652 Integrate functions into their callers when code size is known not to grow.
1655 Common Report Var(flag_inline_functions) Optimization
1656 Integrate functions not declared \"inline\" into their callers when profitable.
1658 finline-functions-called-once
1659 Common Report Var(flag_inline_functions_called_once) Optimization
1660 Integrate functions only required by their single caller.
1663 Common RejectNegative Joined Alias(finline-limit=)
1666 Common RejectNegative Joined UInteger
1667 -finline-limit=<number> Limit the size of inlined functions to <number>.
1670 Common Report Var(flag_inline_atomics) Init(1) Optimization
1671 Inline __atomic operations when a lock free instruction sequence is available.
1674 Common RejectNegative Alias(fcf-protection=,full)
1677 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1678 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1679 instructions have valid targets.
1682 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1685 Enum(cf_protection_level) String(full) Value(CF_FULL)
1688 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1691 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1694 Enum(cf_protection_level) String(none) Value(CF_NONE)
1696 finstrument-functions
1697 Common Report Var(flag_instrument_function_entry_exit)
1698 Instrument function entry and exit with profiling calls.
1700 finstrument-functions-exclude-function-list=
1701 Common RejectNegative Joined
1702 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1704 finstrument-functions-exclude-file-list=
1705 Common RejectNegative Joined
1706 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1709 Common Report Var(flag_ipa_cp) Optimization
1710 Perform interprocedural constant propagation.
1713 Common Report Var(flag_ipa_cp_clone) Optimization
1714 Perform cloning to make Interprocedural constant propagation stronger.
1718 Does nothing. Preserved for backward compatibility.
1721 Common Report Var(flag_ipa_bit_cp) Optimization
1722 Perform interprocedural bitwise constant propagation.
1725 Common Report Var(flag_ipa_profile) Init(0) Optimization
1726 Perform interprocedural profile propagation.
1729 Common Report Var(flag_ipa_pta) Init(0) Optimization
1730 Perform interprocedural points-to analysis.
1733 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1734 Discover pure and const functions.
1737 Common Report Var(flag_ipa_icf) Optimization
1738 Perform Identical Code Folding for functions and read-only variables.
1741 Common Report Var(flag_ipa_icf_functions) Optimization
1742 Perform Identical Code Folding for functions.
1745 Common Report Var(flag_ipa_icf_variables) Optimization
1746 Perform Identical Code Folding for variables.
1749 Common Report Var(flag_ipa_reference) Init(0) Optimization
1750 Discover read-only and non addressable static variables.
1752 fipa-reference-addressable
1753 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1754 Discover read-only, write-only and non-addressable static variables.
1756 fipa-stack-alignment
1757 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1758 Reduce stack alignment on call sites if possible.
1762 Does nothing. Preserved for backward compatibility.
1766 Does nothing. Preserved for backward compatibility.
1769 Common Report Var(flag_ipa_vrp) Optimization
1770 Perform IPA Value Range Propagation.
1773 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1774 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1777 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1780 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1783 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1786 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1787 -fira-region=[one|all|mixed] Set regions for IRA.
1790 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1793 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1796 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1799 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1802 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1803 Use IRA based register pressure calculation
1804 in RTL hoist optimizations.
1807 Common Report Var(flag_ira_loop_pressure) Optimization
1808 Use IRA based register pressure calculation
1809 in RTL loop optimizations.
1811 fira-share-save-slots
1812 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1813 Share slots for saving different hard registers.
1815 fira-share-spill-slots
1816 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1817 Share stack slots for spilled pseudo-registers.
1820 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1821 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1824 Common Report Var(flag_ivopts) Init(1) Optimization
1825 Optimize induction variables on trees.
1828 Common Var(flag_jump_tables) Init(1) Optimization
1829 Use jump tables for sufficiently large switch statements.
1831 fkeep-inline-functions
1832 Common Report Var(flag_keep_inline_functions)
1833 Generate code for functions even if they are fully inlined.
1835 fkeep-static-functions
1836 Common Report Var(flag_keep_static_functions)
1837 Generate code for static functions even if they are never called.
1840 Common Report Var(flag_keep_static_consts) Init(1)
1841 Emit static const variables even if they are not used.
1844 Common Report Var(flag_leading_underscore) Init(-1)
1845 Give external symbols a leading underscore.
1849 Does nothing. Preserved for backward compatibility.
1852 Common Report Var(flag_lra_remat) Optimization
1853 Do CFG-sensitive rematerialization in LRA.
1857 Enable link-time optimization.
1860 Common RejectNegative Joined Var(flag_lto)
1861 Link-time optimization with number of parallel jobs or jobserver.
1864 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1867 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1870 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1873 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1876 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1879 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1882 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1883 Specify the algorithm to partition symbols and vars at linktime.
1885 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1886 flto-compression-level=
1887 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1888 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1890 flto-odr-type-merging
1891 Common Report Var(flag_lto_odr_type_mering) Init(1)
1892 Merge C++ types using One Definition Rule.
1895 Common Report Var(flag_lto_report) Init(0)
1896 Report various link-time optimization statistics.
1899 Common Report Var(flag_lto_report_wpa) Init(0)
1900 Report various link-time optimization statistics for WPA only.
1903 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1904 Set errno after built-in math functions.
1907 Common Joined RejectNegative UInteger Var(flag_max_errors)
1908 -fmax-errors=<number> Maximum number of errors to report.
1911 Common Report Var(mem_report)
1912 Report on permanent memory allocation.
1915 Common Report Var(mem_report_wpa)
1916 Report on permanent memory allocation in WPA only.
1918 ; This will attempt to merge constant section constants, if 1 only
1919 ; string constants and constants from constant pool, if 2 also constant
1921 fmerge-all-constants
1922 Common Report Var(flag_merge_constants,2) Init(1)
1923 Attempt to merge identical constants and constant variables.
1926 Common Report Var(flag_merge_constants,1)
1927 Attempt to merge identical constants across compilation units.
1929 fmerge-debug-strings
1930 Common Report Var(flag_merge_debug_strings) Init(1)
1931 Attempt to merge identical debug strings across compilation units.
1934 Common RejectNegative Joined UInteger
1935 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1938 Common Report Var(flag_modulo_sched) Optimization
1939 Perform SMS based modulo scheduling before the first scheduling pass.
1941 fmodulo-sched-allow-regmoves
1942 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1943 Perform SMS based modulo scheduling with register moves allowed.
1945 fmove-loop-invariants
1946 Common Report Var(flag_move_loop_invariants) Optimization
1947 Move loop invariant computations out of loops.
1950 Common Var(flag_dce) Init(1) Optimization
1951 Use the RTL dead code elimination pass.
1954 Common Var(flag_dse) Init(1) Optimization
1955 Use the RTL dead store elimination pass.
1957 freschedule-modulo-scheduled-loops
1958 Common Report Var(flag_resched_modulo_sched) Optimization
1959 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1961 fnon-call-exceptions
1962 Common Report Var(flag_non_call_exceptions) Optimization
1963 Support synchronous non-call exceptions.
1966 Common Driver Joined MissingArgError(options or targets missing after %qs)
1967 -foffload=<targets>=<options> Specify offloading targets and options for them.
1970 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1971 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1974 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1977 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1980 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1983 Common Report Var(flag_omit_frame_pointer) Optimization
1984 When possible do not generate stack frames.
1987 Common Report Var(flag_opt_info) Optimization
1988 Enable all optimization info dumps on stderr.
1991 Common Joined RejectNegative Var(common_deferred_options) Defer
1992 -fopt-info[-<type>=filename] Dump compiler optimization details.
1994 fsave-optimization-record
1995 Common Report Var(flag_save_optimization_record) Optimization
1996 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
1998 foptimize-register-move
2000 Does nothing. Preserved for backward compatibility.
2002 foptimize-sibling-calls
2003 Common Report Var(flag_optimize_sibling_calls) Optimization
2004 Optimize sibling and tail recursive calls.
2007 Common Report Var(flag_partial_inlining) Optimization
2008 Perform partial inlining.
2011 Common Report Var(pre_ipa_mem_report)
2012 Report on memory allocation before interprocedural optimization.
2014 fpost-ipa-mem-report
2015 Common Report Var(post_ipa_mem_report)
2016 Report on memory allocation before interprocedural optimization.
2019 Common Report Var(flag_pack_struct) Optimization
2020 Pack structure members together without holes.
2023 Common RejectNegative Joined UInteger Optimization
2024 -fpack-struct=<number> Set initial maximum structure member alignment.
2027 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2028 Return small aggregates in memory, not registers.
2031 Common Report Var(flag_peel_loops) Optimization
2032 Perform loop peeling.
2035 Common Report Var(flag_no_peephole,0) Optimization
2036 Enable machine specific peephole optimizations.
2039 Common Report Var(flag_peephole2) Optimization
2040 Enable an RTL peephole pass before sched2.
2043 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2044 Generate position-independent code if possible (large mode).
2047 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2048 Generate position-independent code for executables if possible (large mode).
2051 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2052 Generate position-independent code if possible (small mode).
2055 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2056 Generate position-independent code for executables if possible (small mode).
2059 Common Report Var(flag_plt) Init(1) Optimization
2060 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2063 Common Joined RejectNegative Var(common_deferred_options) Defer
2064 Specify a plugin to load.
2067 Common Joined RejectNegative Var(common_deferred_options) Defer
2068 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2070 fpredictive-commoning
2071 Common Report Var(flag_predictive_commoning) Optimization
2072 Run predictive commoning optimization.
2074 fprefetch-loop-arrays
2075 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2076 Generate prefetch instructions, if available, for arrays in loops.
2079 Common Report Var(profile_flag)
2080 Enable basic program profiling code.
2083 Common Report Var(profile_abs_path_flag)
2084 Generate absolute source path names for gcov.
2087 Common Report Var(profile_arc_flag)
2088 Insert arc-based program profiling code.
2091 Common Joined RejectNegative Var(profile_data_prefix)
2092 Set the top-level directory for storing the profile data.
2093 The default is 'pwd'.
2096 Common Report Var(flag_profile_correction)
2097 Enable correction of flow inconsistent profile data input.
2100 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2101 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2103 fprofile-filter-files=
2104 Common Joined RejectNegative Var(flag_profile_filter_files)
2105 Instrument only functions from files where names match any regular expression (separated by a semi-colon).
2107 fprofile-exclude-files=
2108 Common Joined RejectNegative Var(flag_profile_exclude_files)
2109 Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon).
2112 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2115 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2118 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2121 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2125 Enable common options for generating profile info for profile feedback directed optimizations.
2128 Common Joined RejectNegative
2129 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2132 Common Var(flag_profile_use)
2133 Enable common options for performing profile feedback directed optimizations.
2136 Common Joined RejectNegative
2137 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2140 Common Report Var(flag_profile_values)
2141 Insert code to profile values of expressions.
2144 Common Report Var(profile_report)
2145 Report on consistency of profile.
2147 fprofile-reorder-functions
2148 Common Report Var(flag_profile_reorder_functions)
2149 Enable function reordering that improves code placement.
2151 fpatchable-function-entry=
2152 Common Joined Optimization
2153 Insert NOP instructions at each function entry.
2156 Common Var(common_deferred_options) Defer
2159 Common Joined RejectNegative Var(common_deferred_options) Defer
2160 -frandom-seed=<string> Make compile reproducible using <string>.
2162 ; This switch causes the command line that was used to create an
2163 ; object file to be recorded into the object file. The exact format
2164 ; of this recording is target and binary file format dependent.
2165 ; It is related to the -fverbose-asm switch, but that switch only
2166 ; records information in the assembler output file as comments, so
2167 ; they never reach the object file.
2168 frecord-gcc-switches
2169 Common Report Var(flag_record_gcc_switches)
2170 Record gcc command line switches in the object file.
2173 Common Report Var(flag_pcc_struct_return,0) Optimization
2174 Return small aggregates in registers.
2178 Does nothing. Preserved for backward compatibility.
2181 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2182 Tell DSE that the storage for a C++ object is dead when the constructor
2183 starts and when the destructor finishes.
2186 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2189 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2192 Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2193 -flive-patching=[inline-only-static|inline-clone] Control IPA
2194 optimizations to provide a safe compilation for live-patching. At the same
2195 time, provides multiple-level control on the enabled IPA optimizations.
2198 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2201 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2204 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2206 flive-range-shrinkage
2207 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2208 Relief of register pressure through live range shrinkage.
2211 Common Report Var(flag_rename_registers) Init(2) Optimization
2212 Perform a register renaming optimization pass.
2215 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2216 Perform a target dependent instruction fusion optimization pass.
2219 Common Report Var(flag_reorder_blocks) Optimization
2220 Reorder basic blocks to improve code placement.
2222 freorder-blocks-algorithm=
2223 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2224 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2227 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2230 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2233 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2235 freorder-blocks-and-partition
2236 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2237 Reorder basic blocks and partition into hot and cold sections.
2240 Common Report Var(flag_reorder_functions) Optimization
2241 Reorder functions to improve code placement.
2243 frerun-cse-after-loop
2244 Common Report Var(flag_rerun_cse_after_loop) Optimization
2245 Add a common subexpression elimination pass after loop optimizations.
2249 Does nothing. Preserved for backward compatibility.
2252 Common Report Var(flag_rounding_math) Optimization SetByCombined
2253 Disable optimizations that assume default FP rounding behavior.
2256 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2257 Enable scheduling across basic blocks.
2260 Common Report Var(flag_sched_pressure) Init(0) Optimization
2261 Enable register pressure sensitive insn scheduling.
2264 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2265 Allow speculative motion of non-loads.
2268 Common Report Var(flag_schedule_speculative_load) Optimization
2269 Allow speculative motion of some loads.
2271 fsched-spec-load-dangerous
2272 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2273 Allow speculative motion of more loads.
2276 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2277 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2279 fsched2-use-superblocks
2280 Common Report Var(flag_sched2_use_superblocks) Optimization
2281 If scheduling post reload, do superblock scheduling.
2285 Does nothing. Preserved for backward compatibility.
2288 Common Report Var(flag_schedule_insns) Optimization
2289 Reschedule instructions before register allocation.
2292 Common Report Var(flag_schedule_insns_after_reload) Optimization
2293 Reschedule instructions after register allocation.
2295 ; This flag should be on when a target implements non-trivial
2296 ; scheduling hooks, maybe saving some information for its own sake.
2297 ; On IA64, for example, this is used for correct bundling.
2298 fselective-scheduling
2299 Common Report Var(flag_selective_scheduling) Optimization
2300 Schedule instructions using selective scheduling algorithm.
2302 fselective-scheduling2
2303 Common Report Var(flag_selective_scheduling2) Optimization
2304 Run selective scheduling after reload.
2307 Common Undocumented Joined Var(flag_self_test)
2308 Run self-tests, using the given path to locate test files.
2310 fsel-sched-pipelining
2311 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2312 Perform software pipelining of inner loops during selective scheduling.
2314 fsel-sched-pipelining-outer-loops
2315 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2316 Perform software pipelining of outer loops during selective scheduling.
2318 fsel-sched-reschedule-pipelined
2319 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2320 Reschedule pipelined regions without pipelining.
2322 fsemantic-interposition
2323 Common Report Var(flag_semantic_interposition) Init(1)
2324 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2326 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2327 ; of stalled insns into the ready list.
2328 fsched-stalled-insns
2329 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2330 Allow premature scheduling of queued insns.
2332 fsched-stalled-insns=
2333 Common RejectNegative Joined UInteger Optimization
2334 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2336 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2337 ; be examined for a dependency on a stalled insn that is candidate for
2338 ; premature removal from the queue of stalled insns into the ready list (has
2339 ; an effect only if the flag 'sched_stalled_insns' is set).
2340 fsched-stalled-insns-dep
2341 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2342 Set dependence distance checking in premature scheduling of queued insns.
2344 fsched-stalled-insns-dep=
2345 Common RejectNegative Joined UInteger Optimization
2346 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2348 fsched-group-heuristic
2349 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2350 Enable the group heuristic in the scheduler.
2352 fsched-critical-path-heuristic
2353 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2354 Enable the critical path heuristic in the scheduler.
2356 fsched-spec-insn-heuristic
2357 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2358 Enable the speculative instruction heuristic in the scheduler.
2360 fsched-rank-heuristic
2361 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2362 Enable the rank heuristic in the scheduler.
2364 fsched-last-insn-heuristic
2365 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2366 Enable the last instruction heuristic in the scheduler.
2368 fsched-dep-count-heuristic
2369 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2370 Enable the dependent count heuristic in the scheduler.
2373 Common Report Var(flag_section_anchors) Optimization
2374 Access data in the same section from shared anchor points.
2378 Does nothing. Preserved for backward compatibility.
2382 Does nothing. Preserved for backward compatibility.
2385 Common Report Var(flag_ree) Init(0)
2386 Turn on Redundant Extensions Elimination pass.
2389 Common Report Var(flag_show_column) Init(1)
2390 Show column numbers in diagnostics, when available. Default on.
2393 Common Report Var(flag_shrink_wrap) Optimization
2394 Emit function prologues only before parts of the function that need it,
2395 rather than at the top of the function.
2397 fshrink-wrap-separate
2398 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2399 Shrink-wrap parts of the prologue and epilogue separately.
2402 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2403 Disable optimizations observable by IEEE signaling NaNs.
2406 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2407 Disable floating point optimizations that ignore the IEEE signedness of zero.
2409 fsingle-precision-constant
2410 Common Report Var(flag_single_precision_constant) Optimization
2411 Convert floating point constants to single precision constants.
2413 fsplit-ivs-in-unroller
2414 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2415 Split lifetimes of induction variables when loops are unrolled.
2418 Common Report Var(flag_split_stack) Init(-1)
2419 Generate discontiguous stack frames.
2422 Common Report Var(flag_split_wide_types) Optimization
2423 Split wide types into independent registers.
2426 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2427 Enable backward propagation of use properties at the SSA level.
2430 Common Report Var(flag_ssa_phiopt) Optimization
2431 Optimize conditional patterns using SSA PHI nodes.
2434 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2435 Optimize amount of stdarg registers saved to stack at start of function.
2437 fvariable-expansion-in-unroller
2438 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2439 Apply variable expansion when loops are unrolled.
2442 Common Report RejectNegative Joined Optimization
2443 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2446 Common Alias(fstack-check=, specific, no)
2447 Insert stack checking code into the program. Same as -fstack-check=specific.
2449 fstack-clash-protection
2450 Common Report Var(flag_stack_clash_protection) Optimization
2451 Insert code to probe each page of stack space as it is allocated to protect
2452 from stack-clash style attacks.
2455 Common Var(common_deferred_options) Defer
2457 fstack-limit-register=
2458 Common RejectNegative Joined Var(common_deferred_options) Defer
2459 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2461 fstack-limit-symbol=
2462 Common RejectNegative Joined Var(common_deferred_options) Defer
2463 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2466 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2467 Use propolice as a stack protection method.
2469 fstack-protector-all
2470 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2471 Use a stack protection method for every function.
2473 fstack-protector-strong
2474 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2475 Use a smart stack protection method for certain functions.
2477 fstack-protector-explicit
2478 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2479 Use stack protection method only for functions with the stack_protect attribute.
2482 Common RejectNegative Var(flag_stack_usage)
2483 Output stack usage information on a per-function basis.
2487 Does nothing. Preserved for backward compatibility.
2489 ; Nonzero if we should do (language-dependent) alias analysis.
2490 ; Typically, this analysis will assume that expressions of certain
2491 ; types do not alias expressions of certain other types. Only used
2492 ; if alias analysis (in general) is enabled.
2494 Common Report Var(flag_strict_aliasing) Optimization
2495 Assume strict aliasing rules apply.
2499 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2502 Common Report Var(flag_sync_libcalls) Init(1)
2503 Implement __atomic operations via libcalls to legacy __sync functions.
2506 Common Report Var(flag_syntax_only)
2507 Check for syntax errors, then stop.
2510 Common Report Var(flag_test_coverage)
2511 Create data files needed by \"gcov\".
2514 Common Report Var(flag_thread_jumps) Optimization
2515 Perform jump threading optimizations.
2518 Common Report Var(time_report)
2519 Report the time taken by each compiler pass.
2521 ftime-report-details
2522 Common Report Var(time_report_details)
2523 Record times taken by sub-phases separately.
2526 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2527 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2530 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2533 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2536 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2539 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2542 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2545 Common Report Var(flag_toplevel_reorder) Init(2)
2546 Reorder top level functions, variables, and asms.
2549 Common Report Var(flag_tracer) Optimization
2550 Perform superblock formation via tail duplication.
2553 Common Report Var(flag_trampolines) Init(0)
2554 For targets that normally need trampolines for nested functions, always
2555 generate them instead of using descriptors.
2557 ; Zero means that floating-point math operations cannot generate a
2558 ; (user-visible) trap. This is the case, for example, in nonstop
2559 ; IEEE 754 arithmetic.
2561 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2562 Assume floating-point operations can trap.
2565 Common Report Var(flag_trapv) Optimization
2566 Trap for signed overflow in addition, subtraction and multiplication.
2569 Common Report Var(flag_tree_ccp) Optimization
2570 Enable SSA-CCP optimization on trees.
2573 Common Report Var(flag_tree_bit_ccp) Optimization
2574 Enable SSA-BIT-CCP optimization on trees.
2578 Does nothing. Preserved for backward compatibility.
2581 Common Report Var(flag_tree_ch) Optimization
2582 Enable loop header copying on trees.
2584 ftree-coalesce-inlined-vars
2585 Common Ignore RejectNegative
2586 Does nothing. Preserved for backward compatibility.
2589 Common Report Var(flag_tree_coalesce_vars) Optimization
2590 Enable SSA coalescing of user variables.
2594 Does nothing. Preserved for backward compatibility.
2597 Common Report Var(flag_tree_copy_prop) Optimization
2598 Enable copy propagation on trees.
2600 ftree-store-copy-prop
2602 Does nothing. Preserved for backward compatibility.
2605 Common Report Var(flag_tree_cselim) Init(2) Optimization
2606 Transform condition stores into unconditional ones.
2608 ftree-switch-conversion
2609 Common Report Var(flag_tree_switch_conversion) Optimization
2610 Perform conversions of switch initializations.
2613 Common Report Var(flag_tree_dce) Optimization
2614 Enable SSA dead code elimination optimization on trees.
2616 ftree-dominator-opts
2617 Common Report Var(flag_tree_dom) Optimization
2618 Enable dominator optimizations.
2621 Common Report Var(flag_tree_tail_merge) Optimization
2622 Enable tail merging on trees.
2625 Common Report Var(flag_tree_dse) Optimization
2626 Enable dead store elimination.
2629 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2630 Enable forward propagation on trees.
2633 Common Report Var(flag_tree_fre) Optimization
2634 Enable Full Redundancy Elimination (FRE) on trees.
2637 Common Report Var(flag_optimize_strlen) Optimization
2638 Enable string length optimizations on trees.
2640 fisolate-erroneous-paths-dereference
2641 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2642 Detect paths that trigger erroneous or undefined behavior due to
2643 dereferencing a null pointer. Isolate those paths from the main control
2644 flow and turn the statement with erroneous or undefined behavior into a trap.
2646 fisolate-erroneous-paths-attribute
2647 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2648 Detect paths that trigger erroneous or undefined behavior due to a null value
2649 being used in a way forbidden by a returns_nonnull or nonnull
2650 attribute. Isolate those paths from the main control flow and turn the
2651 statement with erroneous or undefined behavior into a trap.
2653 ftree-loop-distribution
2654 Common Report Var(flag_tree_loop_distribution) Optimization
2655 Enable loop distribution on trees.
2657 ftree-loop-distribute-patterns
2658 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2659 Enable loop distribution for patterns transformed into a library call.
2662 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2663 Enable loop invariant motion on trees.
2666 Common Alias(floop-nest-optimize)
2667 Enable loop nest transforms. Same as -floop-nest-optimize.
2670 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2671 Create canonical induction variables in loops.
2674 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2675 Enable loop optimizations on tree level.
2677 ftree-parallelize-loops=
2678 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2679 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2682 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2683 Enable hoisting loads from conditional pointers.
2686 Common Report Var(flag_tree_pre) Optimization
2687 Enable SSA-PRE optimization on trees.
2690 Common Report Var(flag_tree_partial_pre) Optimization
2691 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2694 Common Report Var(flag_tree_pta) Optimization
2695 Perform function-local points-to analysis on trees.
2698 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2699 Enable reassociation on tree level.
2703 Does nothing. Preserved for backward compatibility.
2706 Common Report Var(flag_tree_sink) Optimization
2707 Enable SSA code sinking on trees.
2710 Common Report Var(flag_tree_slsr) Optimization
2711 Perform straight-line strength reduction.
2714 Common Report Var(flag_tree_sra) Optimization
2715 Perform scalar replacement of aggregates.
2718 Common Report Var(flag_tree_ter) Optimization
2719 Replace temporary expressions in the SSA->normal pass.
2722 Common Report Var(flag_tree_live_range_split) Optimization
2723 Perform live range splitting during the SSA->normal pass.
2726 Common Report Var(flag_tree_vrp) Init(0) Optimization
2727 Perform Value Range Propagation on trees.
2730 Common Report Var(flag_split_paths) Init(0) Optimization
2731 Split paths leading to loop backedges.
2733 funconstrained-commons
2734 Common Var(flag_unconstrained_commons) Optimization
2735 Assume common declarations may be overridden with ones with a larger
2739 Common Report Var(flag_unit_at_a_time) Init(1)
2740 Compile whole compilation unit at a time.
2743 Common Report Var(flag_unroll_loops) Optimization
2744 Perform loop unrolling when iteration count is known.
2747 Common Report Var(flag_unroll_all_loops) Optimization
2748 Perform loop unrolling for all loops.
2750 ; Nonzero means that loop optimizer may assume that the induction variables
2751 ; that control loops do not overflow and that the loops with nontrivial
2752 ; exit condition are not infinite
2753 funsafe-loop-optimizations
2755 Does nothing. Preserved for backward compatibility.
2758 Common Report Var(flag_associative_math) SetByCombined Optimization
2759 Allow optimization for floating-point arithmetic which may change the
2760 result of the operation due to rounding.
2763 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2764 Same as -fassociative-math for expressions which include division.
2766 ; Nonzero means that unsafe floating-point math optimizations are allowed
2767 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2768 ; are allowed to assume that their arguments and results are "normal"
2769 ; (e.g., nonnegative for SQRT).
2770 funsafe-math-optimizations
2771 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2772 Allow math optimizations that may violate IEEE or ISO standards.
2775 Common Report Var(flag_unswitch_loops) Optimization
2776 Perform loop unswitching.
2779 Common Report Var(flag_split_loops) Optimization
2780 Perform loop splitting.
2782 fversion-loops-for-strides
2783 Common Report Var(flag_version_loops_for_strides) Optimization
2784 Version loops based on whether indices have a stride of one.
2787 Common Report Var(flag_unwind_tables) Optimization
2788 Just generate unwind tables for exception handling.
2791 Common Driver Negative(fuse-ld=gold)
2792 Use the bfd linker instead of the default linker.
2795 Common Driver Negative(fuse-ld=bfd)
2796 Use the gold linker instead of the default linker.
2799 Common Driver Negative(fuse-ld=lld)
2800 Use the lld LLVM linker instead of the default linker.
2803 Common Undocumented Var(flag_use_linker_plugin)
2805 ; Positive if we should track variables, negative if we should run
2806 ; the var-tracking pass only to discard debug annotations, zero if
2807 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2808 ; will be set according to optimize, debug_info_level and debug_hooks
2809 ; in process_options ().
2811 Common Report Var(flag_var_tracking) Init(2) PerFunction
2812 Perform variable tracking.
2814 ; Positive if we should track variables at assignments, negative if
2815 ; we should run the var-tracking pass only to discard debug
2816 ; annotations. When flag_var_tracking_assignments ==
2817 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2818 fvar-tracking-assignments
2819 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2820 Perform variable tracking by annotating assignments.
2822 ; Nonzero if we should toggle flag_var_tracking_assignments after
2823 ; processing options and computing its default. */
2824 fvar-tracking-assignments-toggle
2825 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2826 Toggle -fvar-tracking-assignments.
2828 ; Positive if we should track uninitialized variables, negative if
2829 ; we should run the var-tracking pass only to discard debug
2830 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2831 ; will be set according to flag_var_tracking.
2832 fvar-tracking-uninit
2833 Common Report Var(flag_var_tracking_uninit) PerFunction
2834 Perform variable tracking and also tag variables that are uninitialized.
2836 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2838 Common Report Optimization
2839 Enable vectorization on trees.
2841 ftree-vectorizer-verbose=
2842 Common Joined RejectNegative Ignore
2843 Does nothing. Preserved for backward compatibility.
2845 ftree-loop-vectorize
2846 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2847 Enable loop vectorization on trees.
2850 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2851 Enable basic block vectorization (SLP) on trees.
2854 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2855 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2858 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2859 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2862 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2865 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2868 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2871 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2874 Common Alias(fvect-cost-model=,dynamic,unlimited)
2875 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2877 ftree-vect-loop-version
2879 Does nothing. Preserved for backward compatibility.
2882 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2883 Enable copy propagation of scalar-evolution information.
2885 ; -fverbose-asm causes extra commentary information to be produced in
2886 ; the generated assembly code (to make it more readable). This option
2887 ; is generally only of use to those who actually need to read the
2888 ; generated assembly code (perhaps while debugging the compiler itself).
2889 ; -fno-verbose-asm, the default, causes the extra information
2890 ; to not be added and is useful when comparing two assembler files.
2892 Common Report Var(flag_verbose_asm)
2893 Add extra commentary to assembler output.
2896 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2897 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2900 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2903 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2906 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2909 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2912 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2915 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2916 Validate vtable pointers before using them.
2919 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2922 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2925 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2928 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2931 Common Var(flag_vtv_counts)
2932 Output vtable verification counters.
2935 Common Var(flag_vtv_debug)
2936 Output vtable verification pointer sets information.
2939 Common Report Var(flag_value_profile_transformations) Optimization
2940 Use expression value profiles in optimizations.
2943 Common Report Var(flag_web) Init(2) Optimization
2944 Construct webs and split unrelated uses of single variable.
2946 ftree-builtin-call-dce
2947 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2948 Enable conditional dead code elimination for builtin calls.
2951 Common Report Var(flag_whole_program) Init(0)
2952 Perform whole program optimizations.
2955 Common Report Var(flag_wrapv_pointer) Optimization
2956 Assume pointer overflow wraps around.
2959 Common Report Var(flag_wrapv) Optimization
2960 Assume signed arithmetic overflow wraps around.
2962 fzero-initialized-in-bss
2963 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2964 Put zero initialized data in the bss section.
2967 Common Driver RejectNegative JoinedOrMissing
2968 Generate debug information in default format.
2971 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2972 Assume assembler support for (DWARF2+) .loc directives.
2975 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2976 Assume assembler support for view in (DWARF2+) .loc directives.
2979 Common Driver Deprecated
2980 Does nothing. Preserved for backward compatibility.
2983 Common Driver Deprecated
2984 Does nothing. Preserved for backward compatibility.
2987 Common Driver Deprecated
2988 Does nothing. Preserved for backward compatibility.
2991 Common Driver Deprecated
2992 Does nothing. Preserved for backward compatibility.
2995 Common Driver Var(debug_column_info,1) Init(1)
2996 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2999 Common Driver JoinedOrMissing Negative(gdwarf-)
3000 Generate debug information in default version of DWARF format.
3003 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
3004 Generate debug information in DWARF v2 (or later) format.
3007 Common Driver JoinedOrMissing
3008 Generate debug information in default extended format.
3011 Common Driver Var(debug_inline_points) Init(2)
3012 Generate extended entry point information for inlined functions.
3014 ginternal-reset-location-views
3015 Common Driver Var(debug_internal_reset_location_views) Init(2)
3016 Compute locview reset points based on insn length estimates.
3019 RejectNegative Joined Undocumented
3020 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3023 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3024 Don't generate DWARF pubnames and pubtypes sections.
3027 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3028 Generate DWARF pubnames and pubtypes sections.
3031 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3032 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3034 grecord-gcc-switches
3035 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3036 Record gcc command line switches in DWARF DW_AT_producer.
3039 Common Driver Var(dwarf_split_debug_info) Init(0)
3040 Generate debug information in separate .dwo files.
3043 Common Driver JoinedOrMissing Negative(gstabs+)
3044 Generate debug information in STABS format.
3047 Common Driver JoinedOrMissing Negative(gvms)
3048 Generate debug information in extended STABS format.
3050 gstatement-frontiers
3051 Common Driver Var(debug_nonbind_markers_p) Init(2)
3052 Emit progressive recommended breakpoint locations.
3055 Common Driver Report Var(dwarf_strict) Init(0)
3056 Don't emit DWARF additions beyond selected version.
3059 Common Driver Report Var(flag_describe_dies) Init(0)
3060 Add description attributes to some DWARF DIEs that have no name attribute.
3063 Common Driver Report Var(flag_gtoggle)
3064 Toggle debug information generation.
3066 gvariable-location-views
3067 Common Driver Var(debug_variable_location_views, 1) Init(2)
3068 Augment variable location lists with progressive views.
3070 gvariable-location-views=incompat5
3071 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3074 Common Driver JoinedOrMissing Negative(gxcoff)
3075 Generate debug information in VMS format.
3078 Common Driver JoinedOrMissing Negative(gxcoff+)
3079 Generate debug information in XCOFF format.
3082 Common Driver JoinedOrMissing Negative(gdwarf)
3083 Generate debug information in extended XCOFF format.
3086 Name(compressed_debug_sections) Type(int)
3088 ; Since -gz= is completely handled in specs, the values aren't used and we
3089 ; assign arbitrary constants.
3091 Enum(compressed_debug_sections) String(none) Value(0)
3094 Enum(compressed_debug_sections) String(zlib) Value(1)
3097 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3101 Generate compressed debug sections.
3104 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3105 -gz=<format> Generate compressed debug sections in format <format>.
3108 Driver Joined Separate
3111 Common Joined Var(plugindir_string) Init(0)
3112 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3115 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3116 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3119 Driver Joined Separate
3124 no-canonical-prefixes
3140 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3141 -o <file> Place output into <file>.
3144 Common Var(profile_flag)
3145 Enable function profiling.
3148 Driver Var(pass_exit_codes)
3151 Common Alias(Wpedantic)
3154 Common Var(flag_pedantic_errors)
3155 Like -pedantic but issue them as errors.
3161 Driver Var(use_pipes)
3164 Driver JoinedOrMissing Var(print_file_name)
3166 print-libgcc-file-name
3169 print-multi-directory
3170 Driver Var(print_multi_directory)
3173 Driver Var(print_multi_lib)
3175 print-multi-os-directory
3176 Driver Var(print_multi_os_directory)
3179 Driver Var(print_multiarch)
3182 Driver JoinedOrMissing Var(print_prog_name)
3185 Driver Var(print_search_dirs)
3188 Driver Var(print_sysroot)
3190 print-sysroot-headers-suffix
3191 Driver Var(print_sysroot_headers_suffix)
3194 Common Var(quiet_flag) RejectDriver
3195 Do not display functions compiled or elapsed time.
3213 Driver Var(report_times)
3216 Driver JoinedOrMissing
3219 Driver Joined Separate
3223 ; C option, but driver must not handle as "-u ndef".
3226 Common Driver Var(verbose_flag)
3227 Enable verbose output.
3230 Common Var(version_flag) RejectDriver
3231 Display the compiler's version.
3234 Common Var(inhibit_warnings)
3238 Driver Separate Var(wrapper_string)
3241 Driver Joined Separate
3244 Driver RejectNegative Negative(static-pie)
3245 Create a shared library.
3251 Driver Separate Alias(specs=)
3264 ; Documented for Fortran, but always accepted by driver.
3271 ; Documented for Go, but always accepted by driver.
3289 Driver RejectNegative Negative(shared)
3290 Don't create a dynamically linked position independent executable.
3293 Driver RejectNegative Negative(no-pie)
3294 Create a dynamically linked position independent executable.
3297 Driver RejectNegative Negative(pie)
3298 Create a static position independent executable.
3301 Driver Joined Separate
3304 Common Report Var(flag_ipa_ra) Optimization
3305 Use caller save register across calls if possible.
3307 ; This comment is to ensure we retain the blank line above.