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
1080 Does nothing. Preserved for backward compatibility.
1082 fbranch-target-load-optimize2
1084 Does nothing. Preserved for backward compatibility.
1088 Does nothing. Preserved for backward compatibility.
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)
1285 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1286 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1288 ; Required for these enum values.
1293 Name(diagnostic_url_rule) Type(int)
1296 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1299 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1302 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1304 fdiagnostics-format=
1305 Common Joined RejectNegative Enum(diagnostics_output_format)
1306 -fdiagnostics-format=[text|json] Select output format.
1308 ; Required for these enum values.
1313 Name(diagnostics_output_format) Type(int)
1316 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1319 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1321 fdiagnostics-parseable-fixits
1322 Common Var(flag_diagnostics_parseable_fixits)
1323 Print fix-it hints in machine-readable form.
1325 fdiagnostics-generate-patch
1326 Common Var(flag_diagnostics_generate_patch)
1327 Print fix-it hints to stderr in unified diff format.
1329 fdiagnostics-show-option
1330 Common Var(flag_diagnostics_show_option) Init(1)
1331 Amend appropriate diagnostic messages with the command line option that controls them.
1333 fdiagnostics-minimum-margin-width=
1334 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1335 Set minimum width of left margin of source code when showing source.
1338 Common Joined RejectNegative Var(common_deferred_options) Defer
1339 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1342 Common Joined RejectNegative Var(common_deferred_options) Defer
1343 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1346 Common Joined RejectNegative Var(common_deferred_options) Defer
1347 -fdump-<type> Dump various compiler internals to a file.
1350 Driver RejectNegative
1353 Common RejectNegative Joined Var(flag_dump_final_insns)
1354 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1357 Common RejectNegative Joined Var(flag_dump_go_spec)
1358 -fdump-go-spec=filename Write all declarations to file as Go code.
1361 Common Report Var(flag_dump_noaddr)
1362 Suppress output of addresses in debugging dumps.
1365 Common Driver Var(flag_report_bug)
1366 Collect and dump debug information into temporary file if ICE in C/C++
1369 fdump-internal-locations
1370 Common Var(flag_dump_locations) Init(0)
1371 Dump detailed information on GCC's internal representation of source code locations.
1374 Common Var(flag_dump_passes) Init(0)
1375 Dump optimization passes.
1378 Common Report Var(flag_dump_unnumbered)
1379 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1381 fdump-unnumbered-links
1382 Common Report Var(flag_dump_unnumbered_links)
1383 Suppress output of previous and next insn numbers in debugging dumps.
1386 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1387 Enable CFI tables via GAS assembler directives.
1390 Common Report Var(flag_early_inlining) Init(1) Optimization
1391 Perform early inlining.
1393 feliminate-dwarf2-dups
1395 Does nothing. Preserved for backward compatibility.
1398 Common Report Var(flag_ipa_sra) Init(0) Optimization
1399 Perform interprocedural reduction of aggregates.
1401 feliminate-unused-debug-symbols
1402 Common Report Var(flag_debug_only_used_symbols) Init(1)
1403 Perform unused symbol elimination in debug info.
1405 feliminate-unused-debug-types
1406 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1407 Perform unused type elimination in debug info.
1409 femit-class-debug-always
1410 Common Report Var(flag_emit_class_debug_always) Init(0)
1411 Do not suppress C++ class debug information.
1414 Common Report Var(flag_exceptions) Optimization
1415 Enable exception handling.
1417 fexpensive-optimizations
1418 Common Report Var(flag_expensive_optimizations) Optimization
1419 Perform a number of minor, expensive optimizations.
1422 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1423 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1426 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1429 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1432 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1434 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1435 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1436 fpermitted-flt-eval-methods=
1437 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1438 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1441 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)
1444 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1447 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1453 Common Var(flag_fat_lto_objects)
1454 Output lto objects containing both the intermediate language and binary output.
1457 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1458 Assume no NaNs or infinities are generated.
1461 Common Report Var(flag_finite_loops) Optimization
1462 Assume that loops with an exit will terminate and not loop indefinitely.
1465 Common Joined RejectNegative Var(common_deferred_options) Defer
1466 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1469 Common Report Var(flag_float_store) Optimization
1470 Don't allocate floats and doubles in extended-precision registers.
1474 Does nothing. Preserved for backward compatibility.
1477 Common Report Var(flag_forward_propagate) Optimization
1478 Perform a forward propagation pass on RTL.
1481 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1482 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1485 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1488 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1490 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1492 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1495 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1497 ffp-int-builtin-inexact
1498 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1499 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1501 ; Nonzero means don't put addresses of constant functions in registers.
1502 ; Used for compiling the Unix kernel, where strange substitutions are
1503 ; done on the assembly output.
1505 Common Report Var(flag_no_function_cse,0) Optimization
1506 Allow function addresses to be held in registers.
1509 Common Report Var(flag_function_sections)
1510 Place each function into its own section.
1513 Common Report Var(flag_gcse) Optimization
1514 Perform global common subexpression elimination.
1517 Common Report Var(flag_gcse_lm) Init(1) Optimization
1518 Perform enhanced load motion during global common subexpression elimination.
1521 Common Report Var(flag_gcse_sm) Init(0) Optimization
1522 Perform store motion after global common subexpression elimination.
1525 Common Report Var(flag_gcse_las) Init(0) Optimization
1526 Perform redundant load after store elimination in global common subexpression
1530 Common Report Var(flag_gcse_after_reload) Optimization
1531 Perform global common subexpression elimination after register allocation has
1535 Name(dwarf_gnat_encodings) Type(int)
1538 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1541 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1544 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1547 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1548 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1550 ; This option is not documented yet as its semantics will change.
1552 Common Report Var(flag_graphite) Optimization
1553 Enable in and out of Graphite representation.
1556 Common Report Var(flag_graphite_identity) Optimization
1557 Enable Graphite Identity transformation.
1559 fhoist-adjacent-loads
1560 Common Report Var(flag_hoist_adjacent_loads) Optimization
1561 Enable hoisting adjacent loads to encourage generating conditional move
1565 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1566 ; Always keep a pointer to a live memory block
1568 floop-parallelize-all
1569 Common Report Var(flag_loop_parallelize_all) Optimization
1570 Mark all loops as parallel.
1573 Common Alias(floop-nest-optimize)
1574 Enable loop nest transforms. Same as -floop-nest-optimize.
1577 Common Report Var(flag_loop_interchange) Optimization
1578 Enable loop interchange on trees.
1581 Common Alias(floop-nest-optimize)
1582 Enable loop nest transforms. Same as -floop-nest-optimize.
1584 floop-unroll-and-jam
1585 Common Report Var(flag_unroll_jam) Optimization
1586 Perform unroll-and-jam on loops.
1589 Common Report Var(flag_tm)
1590 Enable support for GNU transactional memory.
1593 Common Report Var(flag_gnu_unique) Init(1)
1594 Use STB_GNU_UNIQUE if supported by the assembler.
1598 Does nothing. Preserved for backward compatibility.
1601 Common Report Var(flag_loop_nest_optimize) Optimization
1602 Enable the loop nest optimizer.
1604 fstrict-volatile-bitfields
1605 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1606 Force bitfield accesses to match their type width.
1609 Common Report Var(flag_store_merging) Optimization
1610 Merge adjacent stores.
1612 fguess-branch-probability
1613 Common Report Var(flag_guess_branch_prob) Optimization
1614 Enable guessing of branch probabilities.
1616 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1617 ; Generate position-independent code for executables if possible
1618 ; On SVR4 targets, it also controls whether or not to emit a
1619 ; string identifying the compiler.
1621 Common Report Var(flag_no_ident,0)
1622 Process #ident directives.
1625 Common Report Var(flag_if_conversion) Optimization
1626 Perform conversion of conditional jumps to branchless equivalents.
1629 Common Report Var(flag_if_conversion2) Optimization
1630 Perform conversion of conditional jumps to conditional execution.
1633 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1634 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1637 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1640 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1643 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1646 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1648 ftree-loop-if-convert
1649 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1650 Convert conditional jumps in innermost loops to branchless equivalents.
1652 ftree-loop-if-convert-stores
1654 Does nothing. Preserved for backward compatibility.
1656 ; -finhibit-size-directive inhibits output of .size for ELF.
1657 ; This is used only for compiling crtstuff.c,
1658 ; and it may be extended to other effects
1659 ; needed for crtstuff.c on other systems.
1660 finhibit-size-directive
1661 Common Report Var(flag_inhibit_size_directive)
1662 Do not generate .size directives.
1665 Common Report Var(flag_indirect_inlining) Optimization
1666 Perform indirect inlining.
1668 ; General flag to enable inlining. Specifying -fno-inline will disable
1669 ; all inlining apart from always-inline functions.
1671 Common Report Var(flag_no_inline,0) Init(0) Optimization
1672 Enable inlining of function declared \"inline\", disabling disables all inlining.
1674 finline-small-functions
1675 Common Report Var(flag_inline_small_functions) Optimization
1676 Integrate functions into their callers when code size is known not to grow.
1679 Common Report Var(flag_inline_functions) Optimization
1680 Integrate functions not declared \"inline\" into their callers when profitable.
1682 finline-functions-called-once
1683 Common Report Var(flag_inline_functions_called_once) Optimization
1684 Integrate functions only required by their single caller.
1687 Common RejectNegative Joined Alias(finline-limit=)
1690 Common RejectNegative Joined UInteger
1691 -finline-limit=<number> Limit the size of inlined functions to <number>.
1694 Common Report Var(flag_inline_atomics) Init(1) Optimization
1695 Inline __atomic operations when a lock free instruction sequence is available.
1698 Common RejectNegative Alias(fcf-protection=,full)
1701 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1702 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1703 instructions have valid targets.
1706 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1709 Enum(cf_protection_level) String(full) Value(CF_FULL)
1712 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1715 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1718 Enum(cf_protection_level) String(none) Value(CF_NONE)
1720 finstrument-functions
1721 Common Report Var(flag_instrument_function_entry_exit)
1722 Instrument function entry and exit with profiling calls.
1724 finstrument-functions-exclude-function-list=
1725 Common RejectNegative Joined
1726 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1728 finstrument-functions-exclude-file-list=
1729 Common RejectNegative Joined
1730 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1733 Common Report Var(flag_ipa_cp) Optimization
1734 Perform interprocedural constant propagation.
1737 Common Report Var(flag_ipa_cp_clone) Optimization
1738 Perform cloning to make Interprocedural constant propagation stronger.
1742 Does nothing. Preserved for backward compatibility.
1745 Common Report Var(flag_ipa_bit_cp) Optimization
1746 Perform interprocedural bitwise constant propagation.
1749 Common Report Var(flag_ipa_profile) Init(0) Optimization
1750 Perform interprocedural profile propagation.
1753 Common Report Var(flag_ipa_pta) Init(0) Optimization
1754 Perform interprocedural points-to analysis.
1757 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1758 Discover pure and const functions.
1761 Common Report Var(flag_ipa_icf) Optimization
1762 Perform Identical Code Folding for functions and read-only variables.
1765 Common Report Var(flag_ipa_icf_functions) Optimization
1766 Perform Identical Code Folding for functions.
1769 Common Report Var(flag_ipa_icf_variables) Optimization
1770 Perform Identical Code Folding for variables.
1773 Common Report Var(flag_ipa_reference) Init(0) Optimization
1774 Discover read-only and non addressable static variables.
1776 fipa-reference-addressable
1777 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1778 Discover read-only, write-only and non-addressable static variables.
1780 fipa-stack-alignment
1781 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1782 Reduce stack alignment on call sites if possible.
1786 Does nothing. Preserved for backward compatibility.
1790 Does nothing. Preserved for backward compatibility.
1793 Common Report Var(flag_ipa_vrp) Optimization
1794 Perform IPA Value Range Propagation.
1797 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1798 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1801 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1804 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1807 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1810 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1811 -fira-region=[one|all|mixed] Set regions for IRA.
1814 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1817 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1820 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1823 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1826 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1827 Use IRA based register pressure calculation
1828 in RTL hoist optimizations.
1831 Common Report Var(flag_ira_loop_pressure) Optimization
1832 Use IRA based register pressure calculation
1833 in RTL loop optimizations.
1835 fira-share-save-slots
1836 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1837 Share slots for saving different hard registers.
1839 fira-share-spill-slots
1840 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1841 Share stack slots for spilled pseudo-registers.
1844 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1845 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1848 Common Report Var(flag_ivopts) Init(1) Optimization
1849 Optimize induction variables on trees.
1852 Common Var(flag_jump_tables) Init(1) Optimization
1853 Use jump tables for sufficiently large switch statements.
1855 fkeep-inline-functions
1856 Common Report Var(flag_keep_inline_functions)
1857 Generate code for functions even if they are fully inlined.
1859 fkeep-static-functions
1860 Common Report Var(flag_keep_static_functions)
1861 Generate code for static functions even if they are never called.
1864 Common Report Var(flag_keep_static_consts) Init(1)
1865 Emit static const variables even if they are not used.
1868 Common Report Var(flag_leading_underscore) Init(-1)
1869 Give external symbols a leading underscore.
1873 Does nothing. Preserved for backward compatibility.
1876 Common Report Var(flag_lra_remat) Optimization
1877 Do CFG-sensitive rematerialization in LRA.
1881 Enable link-time optimization.
1884 Common RejectNegative Joined Var(flag_lto)
1885 Link-time optimization with number of parallel jobs or jobserver.
1888 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1891 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1894 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1897 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1900 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1903 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1906 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1907 Specify the algorithm to partition symbols and vars at linktime.
1909 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1910 flto-compression-level=
1911 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
1912 -flto-compression-level=<number> Use zlib/zstd compression level <number> for IL.
1914 flto-odr-type-merging
1916 Does nothing. Preserved for backward compatibility.
1919 Common Report Var(flag_lto_report) Init(0)
1920 Report various link-time optimization statistics.
1923 Common Report Var(flag_lto_report_wpa) Init(0)
1924 Report various link-time optimization statistics for WPA only.
1927 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1928 Set errno after built-in math functions.
1931 Common Joined RejectNegative UInteger Var(flag_max_errors)
1932 -fmax-errors=<number> Maximum number of errors to report.
1935 Common Report Var(mem_report)
1936 Report on permanent memory allocation.
1939 Common Report Var(mem_report_wpa)
1940 Report on permanent memory allocation in WPA only.
1942 ; This will attempt to merge constant section constants, if 1 only
1943 ; string constants and constants from constant pool, if 2 also constant
1945 fmerge-all-constants
1946 Common Report Var(flag_merge_constants,2) Init(1)
1947 Attempt to merge identical constants and constant variables.
1950 Common Report Var(flag_merge_constants,1)
1951 Attempt to merge identical constants across compilation units.
1953 fmerge-debug-strings
1954 Common Report Var(flag_merge_debug_strings) Init(1)
1955 Attempt to merge identical debug strings across compilation units.
1958 Common RejectNegative Joined UInteger
1959 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1962 Common Report Var(flag_modulo_sched) Optimization
1963 Perform SMS based modulo scheduling before the first scheduling pass.
1965 fmodulo-sched-allow-regmoves
1966 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1967 Perform SMS based modulo scheduling with register moves allowed.
1969 fmove-loop-invariants
1970 Common Report Var(flag_move_loop_invariants) Optimization
1971 Move loop invariant computations out of loops.
1974 Common Var(flag_dce) Init(1) Optimization
1975 Use the RTL dead code elimination pass.
1978 Common Var(flag_dse) Init(0) Optimization
1979 Use the RTL dead store elimination pass.
1981 freschedule-modulo-scheduled-loops
1982 Common Report Var(flag_resched_modulo_sched) Optimization
1983 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1985 fnon-call-exceptions
1986 Common Report Var(flag_non_call_exceptions) Optimization
1987 Support synchronous non-call exceptions.
1990 Common Driver Joined MissingArgError(options or targets missing after %qs)
1991 -foffload=<targets>=<options> Specify offloading targets and options for them.
1994 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1995 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1998 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2001 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2004 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2007 Common Report Var(flag_omit_frame_pointer) Optimization
2008 When possible do not generate stack frames.
2011 Common Report Var(flag_opt_info) Optimization
2012 Enable all optimization info dumps on stderr.
2015 Common Joined RejectNegative Var(common_deferred_options) Defer
2016 -fopt-info[-<type>=filename] Dump compiler optimization details.
2018 fsave-optimization-record
2019 Common Report Var(flag_save_optimization_record) Optimization
2020 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2022 foptimize-register-move
2024 Does nothing. Preserved for backward compatibility.
2026 foptimize-sibling-calls
2027 Common Report Var(flag_optimize_sibling_calls) Optimization
2028 Optimize sibling and tail recursive calls.
2031 Common Report Var(flag_partial_inlining) Optimization
2032 Perform partial inlining.
2035 Common Report Var(pre_ipa_mem_report)
2036 Report on memory allocation before interprocedural optimization.
2038 fpost-ipa-mem-report
2039 Common Report Var(post_ipa_mem_report)
2040 Report on memory allocation before interprocedural optimization.
2043 Common Report Var(flag_pack_struct) Optimization
2044 Pack structure members together without holes.
2047 Common RejectNegative Joined UInteger Optimization
2048 -fpack-struct=<number> Set initial maximum structure member alignment.
2051 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2052 Return small aggregates in memory, not registers.
2055 Common Report Var(flag_peel_loops) Optimization
2056 Perform loop peeling.
2059 Common Report Var(flag_no_peephole,0) Optimization
2060 Enable machine specific peephole optimizations.
2063 Common Report Var(flag_peephole2) Optimization
2064 Enable an RTL peephole pass before sched2.
2067 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2068 Generate position-independent code if possible (large mode).
2071 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2072 Generate position-independent code for executables if possible (large mode).
2075 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2076 Generate position-independent code if possible (small mode).
2079 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2080 Generate position-independent code for executables if possible (small mode).
2083 Common Report Var(flag_plt) Init(1) Optimization
2084 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2087 Common Joined RejectNegative Var(common_deferred_options) Defer
2088 Specify a plugin to load.
2091 Common Joined RejectNegative Var(common_deferred_options) Defer
2092 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2094 fpredictive-commoning
2095 Common Report Var(flag_predictive_commoning) Optimization
2096 Run predictive commoning optimization.
2098 fprefetch-loop-arrays
2099 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2100 Generate prefetch instructions, if available, for arrays in loops.
2103 Common Report Var(profile_flag)
2104 Enable basic program profiling code.
2107 Common Report Var(profile_abs_path_flag)
2108 Generate absolute source path names for gcov.
2111 Common Report Var(profile_arc_flag)
2112 Insert arc-based program profiling code.
2115 Common Joined RejectNegative Var(profile_data_prefix)
2116 Set the top-level directory for storing the profile data.
2117 The default is 'pwd'.
2120 Common Joined RejectNegative Var(profile_note_location)
2121 Select the name for storing the profile note file.
2124 Common Report Var(flag_profile_correction)
2125 Enable correction of flow inconsistent profile data input.
2128 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2129 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2131 fprofile-filter-files=
2132 Common Joined RejectNegative Var(flag_profile_filter_files)
2133 Instrument only functions from files where names match any regular expression (separated by a semi-colon).
2135 fprofile-exclude-files=
2136 Common Joined RejectNegative Var(flag_profile_exclude_files)
2137 Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon).
2140 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2143 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2146 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2149 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2153 Enable common options for generating profile info for profile feedback directed optimizations.
2156 Common Joined RejectNegative
2157 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2160 Common Var(flag_profile_use)
2161 Enable common options for performing profile feedback directed optimizations.
2164 Common Joined RejectNegative
2165 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2168 Common Report Var(flag_profile_values)
2169 Insert code to profile values of expressions.
2172 Common Report Var(profile_report)
2173 Report on consistency of profile.
2175 fprofile-reorder-functions
2176 Common Report Var(flag_profile_reorder_functions)
2177 Enable function reordering that improves code placement.
2179 fpatchable-function-entry=
2180 Common Joined Optimization
2181 Insert NOP instructions at each function entry.
2184 Common Var(common_deferred_options) Defer
2187 Common Joined RejectNegative Var(common_deferred_options) Defer
2188 -frandom-seed=<string> Make compile reproducible using <string>.
2190 ; This switch causes the command line that was used to create an
2191 ; object file to be recorded into the object file. The exact format
2192 ; of this recording is target and binary file format dependent.
2193 ; It is related to the -fverbose-asm switch, but that switch only
2194 ; records information in the assembler output file as comments, so
2195 ; they never reach the object file.
2196 frecord-gcc-switches
2197 Common Report Var(flag_record_gcc_switches)
2198 Record gcc command line switches in the object file.
2201 Common Report Var(flag_pcc_struct_return,0) Optimization
2202 Return small aggregates in registers.
2206 Does nothing. Preserved for backward compatibility.
2209 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2210 Tell DSE that the storage for a C++ object is dead when the constructor
2211 starts and when the destructor finishes.
2214 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2217 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2220 Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2221 -flive-patching=[inline-only-static|inline-clone] Control IPA
2222 optimizations to provide a safe compilation for live-patching. At the same
2223 time, provides multiple-level control on the enabled IPA optimizations.
2226 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2229 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2232 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2235 Common Report Var(flag_allocation_dce) Init(1) Optimization
2236 Tell DCE to remove unused C++ allocations.
2238 flive-range-shrinkage
2239 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2240 Relief of register pressure through live range shrinkage.
2243 Common Report Var(flag_rename_registers) Init(2) Optimization
2244 Perform a register renaming optimization pass.
2247 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2248 Perform a target dependent instruction fusion optimization pass.
2251 Common Report Var(flag_reorder_blocks) Optimization
2252 Reorder basic blocks to improve code placement.
2254 freorder-blocks-algorithm=
2255 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2256 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2259 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2262 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2265 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2267 freorder-blocks-and-partition
2268 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2269 Reorder basic blocks and partition into hot and cold sections.
2272 Common Report Var(flag_reorder_functions) Optimization
2273 Reorder functions to improve code placement.
2275 frerun-cse-after-loop
2276 Common Report Var(flag_rerun_cse_after_loop) Optimization
2277 Add a common subexpression elimination pass after loop optimizations.
2281 Does nothing. Preserved for backward compatibility.
2284 Common Report Var(flag_rounding_math) Optimization SetByCombined
2285 Disable optimizations that assume default FP rounding behavior.
2288 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2289 Enable scheduling across basic blocks.
2292 Common Report Var(flag_sched_pressure) Init(0) Optimization
2293 Enable register pressure sensitive insn scheduling.
2296 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2297 Allow speculative motion of non-loads.
2300 Common Report Var(flag_schedule_speculative_load) Optimization
2301 Allow speculative motion of some loads.
2303 fsched-spec-load-dangerous
2304 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2305 Allow speculative motion of more loads.
2308 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2309 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2311 fsched2-use-superblocks
2312 Common Report Var(flag_sched2_use_superblocks) Optimization
2313 If scheduling post reload, do superblock scheduling.
2317 Does nothing. Preserved for backward compatibility.
2320 Common Report Var(flag_schedule_insns) Optimization
2321 Reschedule instructions before register allocation.
2324 Common Report Var(flag_schedule_insns_after_reload) Optimization
2325 Reschedule instructions after register allocation.
2327 ; This flag should be on when a target implements non-trivial
2328 ; scheduling hooks, maybe saving some information for its own sake.
2329 ; On IA64, for example, this is used for correct bundling.
2330 fselective-scheduling
2331 Common Report Var(flag_selective_scheduling) Optimization
2332 Schedule instructions using selective scheduling algorithm.
2334 fselective-scheduling2
2335 Common Report Var(flag_selective_scheduling2) Optimization
2336 Run selective scheduling after reload.
2339 Common Undocumented Joined Var(flag_self_test)
2340 Run self-tests, using the given path to locate test files.
2342 fsel-sched-pipelining
2343 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2344 Perform software pipelining of inner loops during selective scheduling.
2346 fsel-sched-pipelining-outer-loops
2347 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2348 Perform software pipelining of outer loops during selective scheduling.
2350 fsel-sched-reschedule-pipelined
2351 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2352 Reschedule pipelined regions without pipelining.
2354 fsemantic-interposition
2355 Common Report Var(flag_semantic_interposition) Init(1)
2356 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2358 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2359 ; of stalled insns into the ready list.
2360 fsched-stalled-insns
2361 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2362 Allow premature scheduling of queued insns.
2364 fsched-stalled-insns=
2365 Common RejectNegative Joined UInteger Optimization
2366 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2368 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2369 ; be examined for a dependency on a stalled insn that is candidate for
2370 ; premature removal from the queue of stalled insns into the ready list (has
2371 ; an effect only if the flag 'sched_stalled_insns' is set).
2372 fsched-stalled-insns-dep
2373 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2374 Set dependence distance checking in premature scheduling of queued insns.
2376 fsched-stalled-insns-dep=
2377 Common RejectNegative Joined UInteger Optimization
2378 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2380 fsched-group-heuristic
2381 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2382 Enable the group heuristic in the scheduler.
2384 fsched-critical-path-heuristic
2385 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2386 Enable the critical path heuristic in the scheduler.
2388 fsched-spec-insn-heuristic
2389 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2390 Enable the speculative instruction heuristic in the scheduler.
2392 fsched-rank-heuristic
2393 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2394 Enable the rank heuristic in the scheduler.
2396 fsched-last-insn-heuristic
2397 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2398 Enable the last instruction heuristic in the scheduler.
2400 fsched-dep-count-heuristic
2401 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2402 Enable the dependent count heuristic in the scheduler.
2405 Common Report Var(flag_section_anchors) Optimization
2406 Access data in the same section from shared anchor points.
2410 Does nothing. Preserved for backward compatibility.
2414 Does nothing. Preserved for backward compatibility.
2417 Common Report Var(flag_ree) Init(0)
2418 Turn on Redundant Extensions Elimination pass.
2421 Common Report Var(flag_show_column) Init(1)
2422 Show column numbers in diagnostics, when available. Default on.
2425 Common Report Var(flag_shrink_wrap) Optimization
2426 Emit function prologues only before parts of the function that need it,
2427 rather than at the top of the function.
2429 fshrink-wrap-separate
2430 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2431 Shrink-wrap parts of the prologue and epilogue separately.
2434 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2435 Disable optimizations observable by IEEE signaling NaNs.
2438 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2439 Disable floating point optimizations that ignore the IEEE signedness of zero.
2441 fsingle-precision-constant
2442 Common Report Var(flag_single_precision_constant) Optimization
2443 Convert floating point constants to single precision constants.
2445 fsplit-ivs-in-unroller
2446 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2447 Split lifetimes of induction variables when loops are unrolled.
2450 Common Report Var(flag_split_stack) Init(-1)
2451 Generate discontiguous stack frames.
2454 Common Report Var(flag_split_wide_types) Optimization
2455 Split wide types into independent registers.
2457 fsplit-wide-types-early
2458 Common Report Var(flag_split_wide_types_early) Optimization
2459 Split wide types into independent registers earlier.
2462 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2463 Enable backward propagation of use properties at the SSA level.
2466 Common Report Var(flag_ssa_phiopt) Optimization
2467 Optimize conditional patterns using SSA PHI nodes.
2470 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2471 Optimize amount of stdarg registers saved to stack at start of function.
2473 fvariable-expansion-in-unroller
2474 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2475 Apply variable expansion when loops are unrolled.
2478 Common Report RejectNegative Joined Optimization
2479 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2482 Common Alias(fstack-check=, specific, no)
2483 Insert stack checking code into the program. Same as -fstack-check=specific.
2485 fstack-clash-protection
2486 Common Report Var(flag_stack_clash_protection) Optimization
2487 Insert code to probe each page of stack space as it is allocated to protect
2488 from stack-clash style attacks.
2491 Common Var(common_deferred_options) Defer
2493 fstack-limit-register=
2494 Common RejectNegative Joined Var(common_deferred_options) Defer
2495 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2497 fstack-limit-symbol=
2498 Common RejectNegative Joined Var(common_deferred_options) Defer
2499 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2502 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2503 Use propolice as a stack protection method.
2505 fstack-protector-all
2506 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2507 Use a stack protection method for every function.
2509 fstack-protector-strong
2510 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2511 Use a smart stack protection method for certain functions.
2513 fstack-protector-explicit
2514 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2515 Use stack protection method only for functions with the stack_protect attribute.
2518 Common RejectNegative Var(flag_stack_usage)
2519 Output stack usage information on a per-function basis.
2523 Does nothing. Preserved for backward compatibility.
2525 ; Nonzero if we should do (language-dependent) alias analysis.
2526 ; Typically, this analysis will assume that expressions of certain
2527 ; types do not alias expressions of certain other types. Only used
2528 ; if alias analysis (in general) is enabled.
2530 Common Report Var(flag_strict_aliasing) Optimization
2531 Assume strict aliasing rules apply.
2535 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2538 Common Report Var(flag_sync_libcalls) Init(1)
2539 Implement __atomic operations via libcalls to legacy __sync functions.
2542 Common Report Var(flag_syntax_only)
2543 Check for syntax errors, then stop.
2546 Common Report Var(flag_test_coverage)
2547 Create data files needed by \"gcov\".
2550 Common Report Var(flag_thread_jumps) Optimization
2551 Perform jump threading optimizations.
2554 Common Report Var(time_report)
2555 Report the time taken by each compiler pass.
2557 ftime-report-details
2558 Common Report Var(time_report_details)
2559 Record times taken by sub-phases separately.
2562 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2563 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2566 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2569 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2572 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2575 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2578 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2581 Common Report Var(flag_toplevel_reorder) Init(2)
2582 Reorder top level functions, variables, and asms.
2585 Common Report Var(flag_tracer) Optimization
2586 Perform superblock formation via tail duplication.
2589 Common Report Var(flag_trampolines) Init(0)
2590 For targets that normally need trampolines for nested functions, always
2591 generate them instead of using descriptors.
2593 ; Zero means that floating-point math operations cannot generate a
2594 ; (user-visible) trap. This is the case, for example, in nonstop
2595 ; IEEE 754 arithmetic.
2597 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2598 Assume floating-point operations can trap.
2601 Common Report Var(flag_trapv) Optimization
2602 Trap for signed overflow in addition, subtraction and multiplication.
2605 Common Report Var(flag_tree_ccp) Optimization
2606 Enable SSA-CCP optimization on trees.
2609 Common Report Var(flag_tree_bit_ccp) Optimization
2610 Enable SSA-BIT-CCP optimization on trees.
2614 Does nothing. Preserved for backward compatibility.
2617 Common Report Var(flag_tree_ch) Optimization
2618 Enable loop header copying on trees.
2620 ftree-coalesce-inlined-vars
2621 Common Ignore RejectNegative
2622 Does nothing. Preserved for backward compatibility.
2625 Common Report Var(flag_tree_coalesce_vars) Optimization
2626 Enable SSA coalescing of user variables.
2630 Does nothing. Preserved for backward compatibility.
2633 Common Report Var(flag_tree_copy_prop) Optimization
2634 Enable copy propagation on trees.
2636 ftree-store-copy-prop
2638 Does nothing. Preserved for backward compatibility.
2641 Common Report Var(flag_tree_cselim) Init(2) Optimization
2642 Transform condition stores into unconditional ones.
2644 ftree-switch-conversion
2645 Common Report Var(flag_tree_switch_conversion) Optimization
2646 Perform conversions of switch initializations.
2649 Common Report Var(flag_tree_dce) Optimization
2650 Enable SSA dead code elimination optimization on trees.
2652 ftree-dominator-opts
2653 Common Report Var(flag_tree_dom) Optimization
2654 Enable dominator optimizations.
2657 Common Report Var(flag_tree_tail_merge) Optimization
2658 Enable tail merging on trees.
2661 Common Report Var(flag_tree_dse) Optimization
2662 Enable dead store elimination.
2665 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2666 Enable forward propagation on trees.
2669 Common Report Var(flag_tree_fre) Optimization
2670 Enable Full Redundancy Elimination (FRE) on trees.
2673 Common Report Var(flag_optimize_strlen) Optimization
2674 Enable string length optimizations on trees.
2676 fisolate-erroneous-paths-dereference
2677 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2678 Detect paths that trigger erroneous or undefined behavior due to
2679 dereferencing a null pointer. Isolate those paths from the main control
2680 flow and turn the statement with erroneous or undefined behavior into a trap.
2682 fisolate-erroneous-paths-attribute
2683 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2684 Detect paths that trigger erroneous or undefined behavior due to a null value
2685 being used in a way forbidden by a returns_nonnull or nonnull
2686 attribute. Isolate those paths from the main control flow and turn the
2687 statement with erroneous or undefined behavior into a trap.
2689 ftree-loop-distribution
2690 Common Report Var(flag_tree_loop_distribution) Optimization
2691 Enable loop distribution on trees.
2693 ftree-loop-distribute-patterns
2694 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2695 Enable loop distribution for patterns transformed into a library call.
2698 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2699 Enable loop invariant motion on trees.
2702 Common Alias(floop-nest-optimize)
2703 Enable loop nest transforms. Same as -floop-nest-optimize.
2706 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2707 Create canonical induction variables in loops.
2710 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2711 Enable loop optimizations on tree level.
2713 ftree-parallelize-loops=
2714 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2715 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2718 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2719 Enable hoisting loads from conditional pointers.
2722 Common Report Var(flag_tree_pre) Optimization
2723 Enable SSA-PRE optimization on trees.
2726 Common Report Var(flag_tree_partial_pre) Optimization
2727 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2730 Common Report Var(flag_tree_pta) Optimization
2731 Perform function-local points-to analysis on trees.
2734 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2735 Enable reassociation on tree level.
2739 Does nothing. Preserved for backward compatibility.
2742 Common Report Var(flag_tree_sink) Optimization
2743 Enable SSA code sinking on trees.
2746 Common Report Var(flag_tree_slsr) Optimization
2747 Perform straight-line strength reduction.
2750 Common Report Var(flag_tree_sra) Optimization
2751 Perform scalar replacement of aggregates.
2754 Common Report Var(flag_tree_ter) Optimization
2755 Replace temporary expressions in the SSA->normal pass.
2758 Common Report Var(flag_tree_live_range_split) Optimization
2759 Perform live range splitting during the SSA->normal pass.
2762 Common Report Var(flag_tree_vrp) Init(0) Optimization
2763 Perform Value Range Propagation on trees.
2766 Common Report Var(flag_split_paths) Init(0) Optimization
2767 Split paths leading to loop backedges.
2769 funconstrained-commons
2770 Common Var(flag_unconstrained_commons) Optimization
2771 Assume common declarations may be overridden with ones with a larger
2775 Common Report Var(flag_unit_at_a_time) Init(1)
2776 Compile whole compilation unit at a time.
2779 Common Report Var(flag_unroll_loops) Optimization
2780 Perform loop unrolling when iteration count is known.
2783 Common Report Var(flag_unroll_all_loops) Optimization
2784 Perform loop unrolling for all loops.
2786 ; Nonzero means that loop optimizer may assume that the induction variables
2787 ; that control loops do not overflow and that the loops with nontrivial
2788 ; exit condition are not infinite
2789 funsafe-loop-optimizations
2791 Does nothing. Preserved for backward compatibility.
2794 Common Report Var(flag_associative_math) SetByCombined Optimization
2795 Allow optimization for floating-point arithmetic which may change the
2796 result of the operation due to rounding.
2799 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2800 Same as -fassociative-math for expressions which include division.
2802 ; Nonzero means that unsafe floating-point math optimizations are allowed
2803 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2804 ; are allowed to assume that their arguments and results are "normal"
2805 ; (e.g., nonnegative for SQRT).
2806 funsafe-math-optimizations
2807 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2808 Allow math optimizations that may violate IEEE or ISO standards.
2811 Common Report Var(flag_unswitch_loops) Optimization
2812 Perform loop unswitching.
2815 Common Report Var(flag_split_loops) Optimization
2816 Perform loop splitting.
2818 fversion-loops-for-strides
2819 Common Report Var(flag_version_loops_for_strides) Optimization
2820 Version loops based on whether indices have a stride of one.
2823 Common Report Var(flag_unwind_tables) Optimization
2824 Just generate unwind tables for exception handling.
2827 Common Driver Negative(fuse-ld=gold)
2828 Use the bfd linker instead of the default linker.
2831 Common Driver Negative(fuse-ld=bfd)
2832 Use the gold linker instead of the default linker.
2835 Common Driver Negative(fuse-ld=lld)
2836 Use the lld LLVM linker instead of the default linker.
2839 Common Undocumented Var(flag_use_linker_plugin)
2841 ; Positive if we should track variables, negative if we should run
2842 ; the var-tracking pass only to discard debug annotations, zero if
2843 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2844 ; will be set according to optimize, debug_info_level and debug_hooks
2845 ; in process_options ().
2847 Common Report Var(flag_var_tracking) Init(2) PerFunction
2848 Perform variable tracking.
2850 ; Positive if we should track variables at assignments, negative if
2851 ; we should run the var-tracking pass only to discard debug
2852 ; annotations. When flag_var_tracking_assignments ==
2853 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2854 fvar-tracking-assignments
2855 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2856 Perform variable tracking by annotating assignments.
2858 ; Nonzero if we should toggle flag_var_tracking_assignments after
2859 ; processing options and computing its default. */
2860 fvar-tracking-assignments-toggle
2861 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2862 Toggle -fvar-tracking-assignments.
2864 ; Positive if we should track uninitialized variables, negative if
2865 ; we should run the var-tracking pass only to discard debug
2866 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2867 ; will be set according to flag_var_tracking.
2868 fvar-tracking-uninit
2869 Common Report Var(flag_var_tracking_uninit) PerFunction
2870 Perform variable tracking and also tag variables that are uninitialized.
2872 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2874 Common Report Optimization
2875 Enable vectorization on trees.
2877 ftree-vectorizer-verbose=
2878 Common Joined RejectNegative Ignore
2879 Does nothing. Preserved for backward compatibility.
2881 ftree-loop-vectorize
2882 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2883 Enable loop vectorization on trees.
2886 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2887 Enable basic block vectorization (SLP) on trees.
2890 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2891 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2894 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2895 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2898 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2901 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2904 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2907 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2910 Common Alias(fvect-cost-model=,dynamic,unlimited)
2911 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2913 ftree-vect-loop-version
2915 Does nothing. Preserved for backward compatibility.
2918 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2919 Enable copy propagation of scalar-evolution information.
2921 ; -fverbose-asm causes extra commentary information to be produced in
2922 ; the generated assembly code (to make it more readable). This option
2923 ; is generally only of use to those who actually need to read the
2924 ; generated assembly code (perhaps while debugging the compiler itself).
2925 ; -fno-verbose-asm, the default, causes the extra information
2926 ; to not be added and is useful when comparing two assembler files.
2928 Common Report Var(flag_verbose_asm)
2929 Add extra commentary to assembler output.
2932 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2933 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2936 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2939 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2942 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2945 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2948 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2951 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2952 Validate vtable pointers before using them.
2955 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2958 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2961 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2964 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2967 Common Var(flag_vtv_counts)
2968 Output vtable verification counters.
2971 Common Var(flag_vtv_debug)
2972 Output vtable verification pointer sets information.
2975 Common Report Var(flag_value_profile_transformations) Optimization
2976 Use expression value profiles in optimizations.
2979 Common Report Var(flag_web) Init(2) Optimization
2980 Construct webs and split unrelated uses of single variable.
2982 ftree-builtin-call-dce
2983 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2984 Enable conditional dead code elimination for builtin calls.
2987 Common Report Var(flag_whole_program) Init(0)
2988 Perform whole program optimizations.
2991 Common Report Var(flag_wrapv_pointer) Optimization
2992 Assume pointer overflow wraps around.
2995 Common Report Var(flag_wrapv) Optimization
2996 Assume signed arithmetic overflow wraps around.
2998 fzero-initialized-in-bss
2999 Common Report Var(flag_zero_initialized_in_bss) Init(1)
3000 Put zero initialized data in the bss section.
3003 Common Driver RejectNegative JoinedOrMissing
3004 Generate debug information in default format.
3007 Common Driver Var(dwarf2out_as_loc_support) Init(2)
3008 Assume assembler support for (DWARF2+) .loc directives.
3011 Common Driver Var(dwarf2out_as_locview_support) Init(2)
3012 Assume assembler support for view in (DWARF2+) .loc directives.
3015 Common Driver WarnRemoved
3016 Does nothing. Preserved for backward compatibility.
3019 Common Driver WarnRemoved
3020 Does nothing. Preserved for backward compatibility.
3023 Common Driver WarnRemoved
3024 Does nothing. Preserved for backward compatibility.
3027 Common Driver WarnRemoved
3028 Does nothing. Preserved for backward compatibility.
3031 Common Driver Var(debug_column_info,1) Init(1)
3032 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3035 Common Driver JoinedOrMissing Negative(gdwarf-)
3036 Generate debug information in default version of DWARF format.
3039 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
3040 Generate debug information in DWARF v2 (or later) format.
3043 Common Driver JoinedOrMissing
3044 Generate debug information in default extended format.
3047 Common Driver Var(debug_inline_points) Init(2)
3048 Generate extended entry point information for inlined functions.
3050 ginternal-reset-location-views
3051 Common Driver Var(debug_internal_reset_location_views) Init(2)
3052 Compute locview reset points based on insn length estimates.
3055 RejectNegative Joined Undocumented
3056 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3059 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3060 Don't generate DWARF pubnames and pubtypes sections.
3063 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3064 Generate DWARF pubnames and pubtypes sections.
3067 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3068 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3070 grecord-gcc-switches
3071 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3072 Record gcc command line switches in DWARF DW_AT_producer.
3075 Common Driver Var(dwarf_split_debug_info) Init(0)
3076 Generate debug information in separate .dwo files.
3079 Common Driver JoinedOrMissing Negative(gstabs+)
3080 Generate debug information in STABS format.
3083 Common Driver JoinedOrMissing Negative(gvms)
3084 Generate debug information in extended STABS format.
3086 gstatement-frontiers
3087 Common Driver Var(debug_nonbind_markers_p) Init(2)
3088 Emit progressive recommended breakpoint locations.
3091 Common Driver Report Var(dwarf_strict) Init(0)
3092 Don't emit DWARF additions beyond selected version.
3095 Common Driver Report Var(flag_describe_dies) Init(0)
3096 Add description attributes to some DWARF DIEs that have no name attribute.
3099 Common Driver Report Var(flag_gtoggle)
3100 Toggle debug information generation.
3102 gvariable-location-views
3103 Common Driver Var(debug_variable_location_views, 1) Init(2)
3104 Augment variable location lists with progressive views.
3106 gvariable-location-views=incompat5
3107 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3110 Common Driver JoinedOrMissing Negative(gxcoff)
3111 Generate debug information in VMS format.
3114 Common Driver JoinedOrMissing Negative(gxcoff+)
3115 Generate debug information in XCOFF format.
3118 Common Driver JoinedOrMissing Negative(gdwarf)
3119 Generate debug information in extended XCOFF format.
3122 Name(compressed_debug_sections) Type(int)
3124 ; Since -gz= is completely handled in specs, the values aren't used and we
3125 ; assign arbitrary constants.
3127 Enum(compressed_debug_sections) String(none) Value(0)
3130 Enum(compressed_debug_sections) String(zlib) Value(1)
3133 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3137 Generate compressed debug sections.
3140 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3141 -gz=<format> Generate compressed debug sections in format <format>.
3144 Driver Joined Separate
3147 Common Joined Var(plugindir_string) Init(0)
3148 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3151 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3152 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3155 Driver Joined Separate
3160 no-canonical-prefixes
3176 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3177 -o <file> Place output into <file>.
3180 Common Var(profile_flag)
3181 Enable function profiling.
3184 Driver Var(pass_exit_codes)
3187 Common Alias(Wpedantic)
3190 Common Var(flag_pedantic_errors)
3191 Like -pedantic but issue them as errors.
3197 Driver Var(use_pipes)
3200 Driver JoinedOrMissing Var(print_file_name)
3202 print-libgcc-file-name
3205 print-multi-directory
3206 Driver Var(print_multi_directory)
3209 Driver Var(print_multi_lib)
3211 print-multi-os-directory
3212 Driver Var(print_multi_os_directory)
3215 Driver Var(print_multiarch)
3218 Driver JoinedOrMissing Var(print_prog_name)
3221 Driver Var(print_search_dirs)
3224 Driver Var(print_sysroot)
3226 print-sysroot-headers-suffix
3227 Driver Var(print_sysroot_headers_suffix)
3230 Common Var(quiet_flag) RejectDriver
3231 Do not display functions compiled or elapsed time.
3249 Driver Var(report_times)
3252 Driver JoinedOrMissing
3255 Driver Joined Separate
3259 ; C option, but driver must not handle as "-u ndef".
3262 Common Driver Var(verbose_flag)
3263 Enable verbose output.
3266 Common Var(version_flag) RejectDriver
3267 Display the compiler's version.
3270 Common Var(inhibit_warnings)
3274 Driver Separate Var(wrapper_string)
3277 Driver Joined Separate
3280 Driver RejectNegative Negative(static-pie)
3281 Create a shared library.
3287 Driver Separate Alias(specs=)
3300 ; Documented for Fortran, but always accepted by driver.
3307 ; Documented for Go, but always accepted by driver.
3325 Driver RejectNegative Negative(shared)
3326 Don't create a dynamically linked position independent executable.
3329 Driver RejectNegative Negative(no-pie)
3330 Create a dynamically linked position independent executable.
3333 Driver RejectNegative Negative(pie)
3334 Create a static position independent executable.
3337 Driver Joined Separate
3340 Common Report Var(flag_ipa_ra) Optimization
3341 Use caller save register across calls if possible.
3343 ; This comment is to ensure we retain the blank line above.