1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2019 Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
49 ; This variable is set to non-0 only by LTO front-end. 1 indicates that
50 ; the output produced will be used for incrmeental linking (thus weak symbols
51 ; can still be bound) and 2 indicates that the IL is going to be linked and
52 ; and output to LTO object file.
54 enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE
56 ; 0 means straightforward implementation of complex divide acceptable.
57 ; 1 means wide ranges of inputs must work for complex divide.
58 ; 2 means C99-like requirements for complex multiply and divide.
60 int flag_complex_method = 1
62 ; Language specific warning pass for unused results.
64 bool flag_warn_unused_result = false
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
75 int flag_generate_offload = 0
77 ; Nonzero means we should be saving declaration info into a .X file.
79 int flag_gen_aux_info = 0
81 ; Nonzero if we are compiling code for a shared library, zero for
86 ; These two are really VEC(char_p,heap) *.
89 void *flag_instrument_functions_exclude_functions
92 void *flag_instrument_functions_exclude_files
94 ; Generic structs (e.g. templates not explicitly specialized)
95 ; may not have a compilation unit associated with them, and so
96 ; may need to be treated differently from ordinary structs.
98 ; Structs only handled by reference (indirectly), will also usually
99 ; not need as much debugging information.
102 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
105 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
107 ; True if we should exit after parsing options.
109 bool exit_after_options
111 ; Type(s) of debugging information we are producing (if any). See
112 ; flag-types.h for the definitions of the different possible types of
113 ; debugging information.
115 enum debug_info_type write_symbols = NO_DEBUG
117 ; Level of debugging information we are producing. See flag-types.h
118 ; for the definitions of the different possible levels.
120 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
122 ; Nonzero means use GNU-only extensions in the generated symbolic
123 ; debugging information. Currently, this only has an effect when
124 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
126 bool use_gnu_debug_info_extensions
128 ; Original value of maximum field alignment in bytes, specified via
129 ; -fpack-struct=<value>.
131 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
133 ; Type of stack check.
135 enum stack_check_type flag_stack_check = NO_STACK_CHECK
137 ; True if stack usage information needs to be computed.
139 bool flag_stack_usage_info = false
141 ; -dA causes debug commentary information to be produced in
142 ; the generated assembly code (to make it more readable). This option
143 ; is generally only of use to those who actually need to read the
144 ; generated assembly code (perhaps while debugging the compiler itself).
145 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
146 ; to be a catchall for printing debug information in the assembler file.
150 ; How many NOP insns to place at each function entry by default
152 HOST_WIDE_INT function_entry_patch_area_size
154 ; And how far the real asm entry point is into this area
156 HOST_WIDE_INT function_entry_patch_area_start
158 ; Balance between GNAT encodings and standard DWARF to emit.
160 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
162 ; -dP causes the rtl to be emitted as a comment in assembly.
164 int flag_dump_rtl_in_asm
166 ; Whether -da was passed (used only in handle_common_deferred_options).
168 bool flag_dump_all_passed
170 ; Other flags saying which kinds of debugging dump have been requested.
173 int rtl_dump_and_exit
176 int flag_print_asm_name
178 ; Name of top-level original source file (what was input to cpp).
179 ; This comes from the #-command at the beginning of the actual input.
180 ; If there isn't any there, then this is the cc1 input file name.
182 const char *main_input_filename
184 ; Pointer to base name in main_input_filename, with directories and a
185 ; single final extension removed, and the length of this base
189 const char *main_input_basename
192 int main_input_baselength
194 ; Which options have been printed by --help.
198 ; Which enums have been printed by --help. 0 = not printed, no
199 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
202 char *help_enum_printed
204 ; The number of columns for --help output.
206 unsigned int help_columns
208 ; Whether this options structure has been through finish_options
210 bool flag_opts_finished
212 ; What the sanitizer should instrument
214 unsigned int flag_sanitize
216 ; What sanitizers should recover from errors
218 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
220 ; What the coverage sanitizers should instrument
222 unsigned int flag_sanitize_coverage
224 ; Flag whether a prefix has been added to dump_base_name
226 bool dump_base_name_prefixed = false
228 ; Flag whether HSA generation has been explicitely disabled
230 bool flag_disable_hsa = false
242 Common Driver Joined Undocumented
243 Provide bash completion for options starting with provided string.
246 Driver Alias(coverage)
252 Common Separate Alias(d)
255 Common Joined Alias(d)
258 Common Separate Alias(dumpbase)
261 Common Separate Alias(dumpdir)
264 Driver Separate Alias(e)
267 Driver Joined Alias(e)
270 Common Warning Alias(Wextra)
273 Driver Separate Alias(Xassembler)
276 Driver JoinedOrMissing Alias(Xassembler)
279 Driver Separate Alias(Xlinker)
282 Driver JoinedOrMissing Alias(Xlinker)
285 Driver Separate Alias(u)
288 Driver Joined Alias(u)
291 Common Driver Var(help_flag)
292 Display this information.
295 Common Driver Report Joined
296 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
299 Driver Separate Alias(x)
302 Driver Joined Alias(x)
305 Driver Separate Alias(L)
308 Driver Joined Alias(L)
310 -no-canonical-prefixes
311 Driver Alias(no-canonical-prefixes)
313 -no-standard-libraries
314 Driver Alias(nostdlib)
317 Driver Var(no_sysroot_suffix)
326 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
329 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
332 Driver Alias(pass-exit-codes)
335 Common Alias(Wpedantic)
338 Common Alias(pedantic-errors)
344 Driver Alias(static-pie)
350 Driver Separate Alias(B)
353 Driver JoinedOrMissing Alias(B)
359 Driver Separate Alias(print-file-name=)
362 Driver JoinedOrMissing Alias(print-file-name=)
364 -print-libgcc-file-name
365 Driver Alias(print-libgcc-file-name)
367 -print-multi-directory
368 Driver Alias(print-multi-directory)
371 Driver Alias(print-multi-lib)
373 -print-multi-os-directory
374 Driver Alias(print-multi-os-directory)
377 Driver Alias(print-multiarch)
380 Driver Separate Alias(print-prog-name=)
383 Driver JoinedOrMissing Alias(print-prog-name=)
386 Driver Alias(print-search-dirs)
389 Driver Alias(print-sysroot)
391 -print-sysroot-headers-suffix
392 Driver Alias(print-sysroot-headers-suffix)
398 Driver Alias(save-temps)
404 Driver Separate Alias(specs=)
407 Driver Joined Alias(specs=)
413 Driver Alias(symbolic)
417 Alias for --help=target.
425 ;; The driver used to convert options such as --help into forms such
426 ;; as -fhelp; the following four entries are for compatibility with
427 ;; any direct uses of those (undocumented) -f forms
429 Common Driver Alias(-help)
432 Common Driver Joined Alias(-help=)
435 Common Driver Alias(-target-help)
438 Common Driver Alias(-version)
442 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
445 Common Joined Alias(-param)
448 Driver Separate Alias(-sysroot=)
451 Driver JoinedOrMissing
457 Driver Joined Separate
463 Driver Joined Separate
469 Common JoinedOrMissing Optimization
470 -O<number> Set optimization level to <number>.
474 Optimize for space rather than speed.
478 Optimize for speed disregarding exact standards compliance.
482 Optimize for debugging experience rather than speed or size.
494 Driver Joined Separate
500 Driver Joined Separate
521 Common RejectNegative Warning Alias(Wextra)
522 This switch is deprecated; use -Wextra instead.
525 Driver JoinedOrMissing RejectNegative
528 Driver JoinedOrMissing RejectNegative
531 Driver JoinedOrMissing RejectNegative
534 Common Var(warn_aggregate_return) Warning
535 Warn about returning structures, unions or arrays.
537 Waggressive-loop-optimizations
538 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
539 Warn if a loop with constant number of iterations triggers undefined behavior.
542 Common Var(warn_array_bounds) Warning
543 Warn if an array is accessed out of bounds.
546 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
547 Warn if an array is accessed out of bounds.
550 Common Var(warn_attributes) Init(1) Warning
551 Warn about inappropriate attribute usage.
554 Common Alias(Wattribute_alias=, 1, 0) Warning
555 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
558 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
559 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
562 Common Var(warn_cannot_profile) Init(1) Warning
563 Warn when profiling instrumentation was requested, but could not be applied to
567 Common Var(warn_cast_align) Warning
568 Warn about pointer casts which increase alignment.
571 Common Var(warn_cast_align,2) Warning
572 Warn about pointer casts which increase alignment.
575 Common Var(warn_cpp) Init(1) Warning
576 Warn when a #warning directive is encountered.
579 Common Var(warn_attribute_warning) Init(1) Warning
580 Warn about uses of __attribute__((warning)) declarations.
583 Common Var(warn_deprecated) Init(1) Warning
584 Warn if a deprecated compiler feature, class, method, or field is used.
586 Wdeprecated-declarations
587 Common Var(warn_deprecated_decl) Init(1) Warning
588 Warn about uses of __attribute__((deprecated)) declarations.
590 Wdisabled-optimization
591 Common Var(warn_disabled_optimization) Warning
592 Warn when an optimization pass is disabled.
595 Common Var(warnings_are_errors)
596 Treat all warnings as errors.
600 Treat specified warning as error.
603 Common Var(extra_warnings) Warning
604 Print extra (possibly unwanted) warnings.
607 Common Var(flag_fatal_errors)
608 Exit on the first error occurred.
611 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
612 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
615 Common Var(warn_free_nonheap_object) Init(1) Warning
616 Warn when attempting to free a non-heap object.
619 Common Var(warn_hsa) Init(1) Warning
620 Warn when a function cannot be expanded to HSAIL.
622 Wimplicit-fallthrough
623 Common Alias(Wimplicit-fallthrough=,3,0) Warning
625 Wimplicit-fallthrough=
626 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
627 Warn when a switch case falls through.
630 Common Var(warn_inline) Warning
631 Warn when an inlined function cannot be inlined.
633 Winvalid-memory-model
634 Common Var(warn_invalid_memory_model) Init(1) Warning
635 Warn when an atomic memory model parameter is known to be outside the valid range.
638 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
641 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
642 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
645 Var(warn_nonnull_compare) Warning
646 Warn if comparing pointer parameter with nonnull attribute with NULL.
649 Common Var(warn_null_dereference) Warning
650 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
652 Wunsafe-loop-optimizations
653 Common Ignore Warning
654 Does nothing. Preserved for backward compatibility.
657 Common Warning Alias(Wsuggest-attribute=noreturn)
660 Common Var(warn_odr_violations) Init(1) Warning
661 Warn about some C++ One Definition Rule violations during link time optimization.
664 Common Var(warn_overflow) Init(1) Warning
665 Warn about overflow in arithmetic expressions.
668 Common Var(warn_lto_type_mismatch) Init(1) Warning
669 During link time optimization warn about mismatched types of global declarations.
672 Common Var(warn_packed) Warning
673 Warn when the packed attribute has no effect on struct layout.
676 Common Var(warn_padded) Warning
677 Warn when padding is required to align structure members.
680 Common Var(pedantic) Init(0) Warning
681 Issue warnings needed for strict compliance to the standard.
684 Common Var(warn_return_local_addr) Init(1) Warning
685 Warn about returning a pointer/reference to a local or temporary variable.
688 Common Var(warn_shadow) Warning
689 Warn when one variable shadows another. Same as -Wshadow=global.
692 Common Warning Alias(Wshadow)
693 Warn when one variable shadows another (globally).
696 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
697 Warn when one local variable shadows another local variable or parameter.
700 Common Warning Undocumented Alias(Wshadow=local)
702 Wshadow=compatible-local
703 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
704 Warn when one local variable shadows another local variable or parameter of compatible type.
706 Wshadow-compatible-local
707 Common Warning Undocumented Alias(Wshadow=compatible-local)
710 Common Var(warn_stack_protect) Warning
711 Warn when not issuing stack smashing protection for some reason.
714 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
715 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
719 Warn about code which might break strict aliasing rules.
722 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
723 Warn about code which might break strict aliasing rules.
727 Warn about optimizations that assume that signed overflow is undefined.
730 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
731 Warn about optimizations that assume that signed overflow is undefined.
733 Wsuggest-attribute=cold
734 Common Var(warn_suggest_attribute_cold) Warning
735 Warn about functions which might be candidates for __attribute__((cold)).
737 Wsuggest-attribute=const
738 Common Var(warn_suggest_attribute_const) Warning
739 Warn about functions which might be candidates for __attribute__((const)).
741 Wsuggest-attribute=pure
742 Common Var(warn_suggest_attribute_pure) Warning
743 Warn about functions which might be candidates for __attribute__((pure)).
745 Wsuggest-attribute=noreturn
746 Common Var(warn_suggest_attribute_noreturn) Warning
747 Warn about functions which might be candidates for __attribute__((noreturn)).
749 Wsuggest-attribute=malloc
750 Common Var(warn_suggest_attribute_malloc) Warning
751 Warn about functions which might be candidates for __attribute__((malloc)).
754 Common Var(warn_suggest_final_types) Warning
755 Warn about C++ polymorphic types where adding final keyword would improve code quality.
757 Wsuggest-final-methods
758 Common Var(warn_suggest_final_methods) Warning
759 Warn about C++ virtual methods where adding final keyword would improve code quality.
762 Common Var(warn_switch_unreachable) Warning Init(1)
763 Warn about statements between switch's controlling expression and the first
767 Common Var(warn_system_headers) Warning
768 Do not suppress warnings from system headers.
771 Common Var(warn_trampolines) Warning
772 Warn whenever a trampoline is generated.
775 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
776 Warn if a comparison is always true or always false due to the limited range of the data type.
779 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
780 Warn about uninitialized automatic variables.
783 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
784 Warn about maybe uninitialized automatic variables.
787 Common Ignore Warning
788 Does nothing. Preserved for backward compatibility.
791 Common Var(warn_unused) Init(0) Warning
792 Enable all -Wunused- warnings.
794 Wunused-but-set-parameter
795 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
796 Warn when a function parameter is only set, otherwise unused.
798 Wunused-but-set-variable
799 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
800 Warn when a variable is only set, otherwise unused.
803 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
804 Warn when a function is unused.
807 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
808 Warn when a label is unused.
811 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
812 Warn when a function parameter is unused.
815 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
816 Warn when an expression value is unused.
819 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
820 Warn when a variable is unused.
823 Common Var(warn_coverage_mismatch) Init(1) Warning
824 Warn in case profiles in -fprofile-use do not match.
827 Common Var(warn_missing_profile) Init(1) Warning
828 Warn in case profiles in -fprofile-use do not exist.
830 Wvector-operation-performance
831 Common Var(warn_vector_operation_performance) Warning
832 Warn when a vector operation is compiled outside the SIMD.
847 Common Separate Var(aux_info_file_name)
848 -aux-info <file> Emit declaration information into <file>.
851 Common Joined Alias(aux-info)
854 Common Separate RejectDriver Var(aux_base_name)
857 Common Separate RejectDriver
867 -d<letters> Enable dumps from specific passes of the compiler.
870 Common Separate Var(dump_base_name)
871 -dumpbase <file> Set the file basename to be used for dumps.
874 Common Separate Var(dump_dir_name)
875 -dumpdir <dir> Set the directory name to be used for dumps.
890 Driver Joined Separate
892 ; This option has historically been passed down to the linker by an
893 ; accident of a %{e*} spec, so ensure it continues to be passed down
894 ; as a single option. The supported option for this purpose is
895 ; -rdynamic. See PR 47390.
899 ; The version of the C++ ABI in use. The following values are allowed:
901 ; 0: The version of the ABI believed most conformant with the C++ ABI
902 ; specification. This ABI may change as bugs are discovered and fixed.
903 ; Therefore, 0 will not necessarily indicate the same ABI in different
906 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
908 ; 2: The version of the ABI first used in G++ 3.4, and the default
911 ; 3: The version of the ABI that fixes the missing underscore
912 ; in template non-type arguments of pointer type.
914 ; 4: The version of the ABI that introduces unambiguous mangling of
915 ; vector types. First selectable in G++ 4.5.
917 ; 5: The version of the ABI that ignores attribute const/noreturn
918 ; in function pointer mangling, and corrects mangling of decltype and
919 ; function parameters used in other parameters and the return type.
920 ; First selectable in G++ 4.6.
922 ; 6: The version of the ABI that doesn't promote scoped enums to int and
923 ; changes the mangling of template argument packs, const/static_cast,
924 ; prefix ++ and --, and a class scope function used as a template
926 ; First selectable in G++ 4.7.
928 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
929 ; corrects the mangling of lambdas in default argument scope.
930 ; First selectable in G++ 4.8.
932 ; 8: The version of the ABI that corrects the substitution behavior of
933 ; function types with function-cv-qualifiers.
934 ; First selectable in G++ 4.9 and default in G++ 5.
936 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
937 ; First selectable and default in G++ 5.2.
939 ; 10: The version of the ABI that mangles attributes that affect type
940 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
941 ; Default in G++ 6 (set in c_common_post_options).
943 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
944 ; and introduces new inheriting constructor handling.
947 ; 12: Corrects the calling convention for classes with only deleted copy/move
948 ; constructors and changes passing/returning of empty records.
949 ; Default in G++ 8.1.
951 ; 13: Fixes the accidental change in 12 to the calling convention for classes
952 ; with deleted copy constructor and trivial move constructor.
953 ; Default in G++ 8.2.
955 ; Additional positive integers will be assigned as new versions of
956 ; the ABI become the default version of the ABI.
958 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
959 The version of the C++ ABI in use.
961 faggressive-loop-optimizations
962 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
963 Aggressively optimize loops using language constraints.
966 Common Report Var(flag_align_functions) Optimization
967 Align the start of functions.
970 Common RejectNegative Joined Var(str_align_functions) Optimization
972 flimit-function-alignment
973 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
976 Common Report Var(flag_align_jumps) Optimization
977 Align labels which are only reached by jumping.
980 Common RejectNegative Joined Var(str_align_jumps) Optimization
983 Common Report Var(flag_align_labels) Optimization
987 Common RejectNegative Joined Var(str_align_labels) Optimization
990 Common Report Var(flag_align_loops) Optimization
991 Align the start of loops.
994 Common RejectNegative Joined Var(str_align_loops) Optimization
998 Does nothing. Preserved for backward compatibility.
1002 Does nothing. Preserved for backward compatibility.
1004 fargument-noalias-global
1006 Does nothing. Preserved for backward compatibility.
1008 fargument-noalias-anything
1010 Does nothing. Preserved for backward compatibility.
1013 Common Driver Report Joined
1014 Select what to sanitize.
1017 Common Report Joined
1018 Select type of coverage sanitization.
1020 fasan-shadow-offset=
1021 Common Joined RejectNegative Var(common_deferred_options) Defer
1022 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1025 Common Joined RejectNegative Var(common_deferred_options) Defer
1026 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1027 in user-defined sections.
1030 Common Report Joined
1031 After diagnosing undefined behavior attempt to continue execution.
1035 This switch is deprecated; use -fsanitize-recover= instead.
1037 fsanitize-address-use-after-scope
1038 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1040 fsanitize-undefined-trap-on-error
1041 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1042 Use trap instead of a library function for undefined behavior sanitization.
1044 fasynchronous-unwind-tables
1045 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1046 Generate unwind tables that are exact at each instruction boundary.
1049 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1050 Generate auto-inc/dec instructions.
1053 Common Report Var(flag_auto_profile)
1054 Use sample profile information for call graph node weights. The default
1055 profile file is fbdata.afdo in 'pwd'.
1058 Common Joined RejectNegative Var(auto_profile_file)
1059 Use sample profile information for call graph node weights. The profile
1060 file is specified in the argument.
1062 ; -fcheck-bounds causes gcc to generate array bounds checks.
1063 ; For C, C++ and ObjC: defaults off.
1064 ; For Java: defaults to on.
1065 ; For Fortran: defaults to off.
1067 Common Report Var(flag_bounds_check)
1068 Generate code to check bounds before indexing arrays.
1071 Common Report Var(flag_branch_on_count_reg) Optimization
1072 Replace add, compare, branch with branch on count register.
1074 fbranch-probabilities
1075 Common Report Var(flag_branch_probabilities) Optimization
1076 Use profiling information for branch probabilities.
1078 fbranch-target-load-optimize
1079 Common Report Var(flag_branch_target_load_optimize) Optimization
1080 Perform branch target load optimization before prologue / epilogue threading.
1082 fbranch-target-load-optimize2
1083 Common Report Var(flag_branch_target_load_optimize2) Optimization
1084 Perform branch target load optimization after prologue / epilogue threading.
1087 Common Report Var(flag_btr_bb_exclusive) Optimization
1088 Restrict target load migration not to re-use registers in any basic block.
1091 Common Joined RejectNegative Var(common_deferred_options) Defer
1092 -fcall-saved-<register> Mark <register> as being preserved across functions.
1095 Common Joined RejectNegative Var(common_deferred_options) Defer
1096 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1098 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1099 ; be saved across function calls, if that produces overall better code.
1100 ; Optional now, so people can test it.
1102 Common Report Var(flag_caller_saves) Optimization
1103 Save registers around function calls.
1107 This switch is deprecated; do not use.
1110 Common Var(flag_check_new)
1111 Check the return value of new in C++.
1114 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1115 Perform internal consistency checkings.
1118 Common Joined RejectNegative UInteger Var(flag_checking)
1119 Perform internal consistency checkings.
1122 Common Report Var(flag_code_hoisting) Optimization
1123 Enable code hoisting.
1125 fcombine-stack-adjustments
1126 Common Report Var(flag_combine_stack_adjustments) Optimization
1127 Looks for opportunities to reduce stack adjustments and stack references.
1130 Common Report Var(flag_no_common,0)
1131 Do not put uninitialized globals in the common section.
1135 ; Converted by the driver to -fcompare-debug= options.
1138 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1139 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1141 fcompare-debug-second
1142 Common Driver RejectNegative Var(flag_compare_debug)
1143 Run only the second compilation of -fcompare-debug.
1146 Common Report Var(flag_compare_elim_after_reload) Optimization
1147 Perform comparison elimination after register allocation has finished.
1150 Common Var(flag_conserve_stack) Optimization
1151 Do not perform optimizations increasing noticeably stack usage.
1154 Common Report Var(flag_cprop_registers) Optimization
1155 Perform a register copy-propagation optimization pass.
1158 Common Report Var(flag_crossjumping) Optimization
1159 Perform cross-jumping optimization.
1162 Common Report Var(flag_cse_follow_jumps) Optimization
1163 When running CSE, follow jumps to their targets.
1167 Does nothing. Preserved for backward compatibility.
1170 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1171 Omit range reduction step when performing complex division.
1174 Common Report Var(flag_cx_fortran_rules) Optimization
1175 Complex multiplication and division follow Fortran rules.
1178 Common Report Var(flag_data_sections)
1179 Place data items into their own section.
1182 Common Report Var(common_deferred_options) Defer
1183 List all available debugging counters with their limits and counts.
1186 Common RejectNegative Joined Var(common_deferred_options) Defer
1187 -fdbg-cnt=<counter>[:<lower_limit>]:<upper_limit>[,<counter>:...] Set the debug counter limit.
1190 Common Joined RejectNegative Var(common_deferred_options) Defer
1191 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1194 Common Joined RejectNegative Var(common_deferred_options) Defer
1195 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1197 fdebug-types-section
1198 Common Report Var(flag_debug_types_section) Init(0)
1199 Output .debug_types section when using DWARF v4 debuginfo.
1201 ; Nonzero for -fdefer-pop: don't pop args after each function call
1202 ; instead save them up to pop many calls' args with one insns.
1204 Common Report Var(flag_defer_pop) Optimization
1205 Defer popping functions args from stack until later.
1208 Common Report Var(flag_delayed_branch) Optimization
1209 Attempt to fill delay slots of branch instructions.
1211 fdelete-dead-exceptions
1212 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1213 Delete dead instructions that may throw exceptions.
1215 fdelete-null-pointer-checks
1216 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1217 Delete useless null pointer checks.
1219 fdevirtualize-at-ltrans
1220 Common Report Var(flag_ltrans_devirtualize)
1221 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1223 fdevirtualize-speculatively
1224 Common Report Var(flag_devirtualize_speculatively) Optimization
1225 Perform speculative devirtualization.
1228 Common Report Var(flag_devirtualize) Optimization
1229 Try to convert virtual calls to direct ones.
1231 fdiagnostics-show-location=
1232 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1233 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1235 ; Required for these enum values.
1240 Name(diagnostic_prefixing_rule) Type(int)
1243 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1246 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1248 fdiagnostics-show-caret
1249 Common Var(flag_diagnostics_show_caret) Init(1)
1250 Show the source line with a caret indicating the column.
1252 fdiagnostics-show-labels
1253 Common Var(flag_diagnostics_show_labels) Init(1)
1254 Show labels annotating ranges of source code when showing source.
1256 fdiagnostics-show-line-numbers
1257 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1258 Show line numbers in the left margin when showing source.
1261 Common Alias(fdiagnostics-color=,always,never)
1265 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1266 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1268 ; Required for these enum values.
1273 Name(diagnostic_color_rule) Type(int)
1276 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1279 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1282 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1284 fdiagnostics-format=
1285 Common Joined RejectNegative Enum(diagnostics_output_format)
1286 -fdiagnostics-format=[text|json] Select output format.
1288 ; Required for these enum values.
1293 Name(diagnostics_output_format) Type(int)
1296 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1299 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1301 fdiagnostics-parseable-fixits
1302 Common Var(flag_diagnostics_parseable_fixits)
1303 Print fix-it hints in machine-readable form.
1305 fdiagnostics-generate-patch
1306 Common Var(flag_diagnostics_generate_patch)
1307 Print fix-it hints to stderr in unified diff format.
1309 fdiagnostics-show-option
1310 Common Var(flag_diagnostics_show_option) Init(1)
1311 Amend appropriate diagnostic messages with the command line option that controls them.
1313 fdiagnostics-minimum-margin-width=
1314 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1315 Set minimum width of left margin of source code when showing source.
1318 Common Joined RejectNegative Var(common_deferred_options) Defer
1319 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1322 Common Joined RejectNegative Var(common_deferred_options) Defer
1323 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1326 Common Joined RejectNegative Var(common_deferred_options) Defer
1327 -fdump-<type> Dump various compiler internals to a file.
1330 Driver RejectNegative
1333 Common RejectNegative Joined Var(flag_dump_final_insns)
1334 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1337 Common RejectNegative Joined Var(flag_dump_go_spec)
1338 -fdump-go-spec=filename Write all declarations to file as Go code.
1341 Common Report Var(flag_dump_noaddr)
1342 Suppress output of addresses in debugging dumps.
1345 Common Driver Var(flag_report_bug)
1346 Collect and dump debug information into temporary file if ICE in C/C++
1349 fdump-internal-locations
1350 Common Var(flag_dump_locations) Init(0)
1351 Dump detailed information on GCC's internal representation of source code locations.
1354 Common Var(flag_dump_passes) Init(0)
1355 Dump optimization passes.
1358 Common Report Var(flag_dump_unnumbered)
1359 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1361 fdump-unnumbered-links
1362 Common Report Var(flag_dump_unnumbered_links)
1363 Suppress output of previous and next insn numbers in debugging dumps.
1366 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1367 Enable CFI tables via GAS assembler directives.
1370 Common Report Var(flag_early_inlining) Init(1) Optimization
1371 Perform early inlining.
1373 feliminate-dwarf2-dups
1375 Does nothing. Preserved for backward compatibility.
1378 Common Report Var(flag_ipa_sra) Init(0) Optimization
1379 Perform interprocedural reduction of aggregates.
1381 feliminate-unused-debug-symbols
1382 Common Report Var(flag_debug_only_used_symbols) Init(1)
1383 Perform unused symbol elimination in debug info.
1385 feliminate-unused-debug-types
1386 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1387 Perform unused type elimination in debug info.
1389 femit-class-debug-always
1390 Common Report Var(flag_emit_class_debug_always) Init(0)
1391 Do not suppress C++ class debug information.
1394 Common Report Var(flag_exceptions) Optimization
1395 Enable exception handling.
1397 fexpensive-optimizations
1398 Common Report Var(flag_expensive_optimizations) Optimization
1399 Perform a number of minor, expensive optimizations.
1402 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1403 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1406 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1409 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1412 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1414 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1415 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1416 fpermitted-flt-eval-methods=
1417 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1418 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1421 Name(permitted_flt_eval_methods) Type(enum permitted_flt_eval_methods) UnknownError(unknown specification for the set of FLT_EVAL_METHOD values to permit %qs)
1424 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1427 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1433 Common Var(flag_fat_lto_objects)
1434 Output lto objects containing both the intermediate language and binary output.
1437 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1438 Assume no NaNs or infinities are generated.
1441 Common Report Var(flag_finite_loops) Optimization
1442 Assume that loops with an exit will terminate and not loop indefinitely.
1445 Common Joined RejectNegative Var(common_deferred_options) Defer
1446 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1449 Common Report Var(flag_float_store) Optimization
1450 Don't allocate floats and doubles in extended-precision registers.
1454 Does nothing. Preserved for backward compatibility.
1457 Common Report Var(flag_forward_propagate) Optimization
1458 Perform a forward propagation pass on RTL.
1461 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1462 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1465 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1468 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1470 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1472 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1475 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1477 ffp-int-builtin-inexact
1478 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1479 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1481 ; Nonzero means don't put addresses of constant functions in registers.
1482 ; Used for compiling the Unix kernel, where strange substitutions are
1483 ; done on the assembly output.
1485 Common Report Var(flag_no_function_cse,0) Optimization
1486 Allow function addresses to be held in registers.
1489 Common Report Var(flag_function_sections)
1490 Place each function into its own section.
1493 Common Report Var(flag_gcse) Optimization
1494 Perform global common subexpression elimination.
1497 Common Report Var(flag_gcse_lm) Init(1) Optimization
1498 Perform enhanced load motion during global common subexpression elimination.
1501 Common Report Var(flag_gcse_sm) Init(0) Optimization
1502 Perform store motion after global common subexpression elimination.
1505 Common Report Var(flag_gcse_las) Init(0) Optimization
1506 Perform redundant load after store elimination in global common subexpression
1510 Common Report Var(flag_gcse_after_reload) Optimization
1511 Perform global common subexpression elimination after register allocation has
1515 Name(dwarf_gnat_encodings) Type(int)
1518 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1521 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1524 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1527 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1528 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1530 ; This option is not documented yet as its semantics will change.
1532 Common Report Var(flag_graphite) Optimization
1533 Enable in and out of Graphite representation.
1536 Common Report Var(flag_graphite_identity) Optimization
1537 Enable Graphite Identity transformation.
1539 fhoist-adjacent-loads
1540 Common Report Var(flag_hoist_adjacent_loads) Optimization
1541 Enable hoisting adjacent loads to encourage generating conditional move
1545 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1546 ; Always keep a pointer to a live memory block
1548 floop-parallelize-all
1549 Common Report Var(flag_loop_parallelize_all) Optimization
1550 Mark all loops as parallel.
1553 Common Alias(floop-nest-optimize)
1554 Enable loop nest transforms. Same as -floop-nest-optimize.
1557 Common Report Var(flag_loop_interchange) Optimization
1558 Enable loop interchange on trees.
1561 Common Alias(floop-nest-optimize)
1562 Enable loop nest transforms. Same as -floop-nest-optimize.
1564 floop-unroll-and-jam
1565 Common Report Var(flag_unroll_jam) Optimization
1566 Perform unroll-and-jam on loops.
1569 Common Report Var(flag_tm)
1570 Enable support for GNU transactional memory.
1573 Common Report Var(flag_gnu_unique) Init(1)
1574 Use STB_GNU_UNIQUE if supported by the assembler.
1578 Does nothing. Preserved for backward compatibility.
1581 Common Report Var(flag_loop_nest_optimize) Optimization
1582 Enable the loop nest optimizer.
1584 fstrict-volatile-bitfields
1585 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1586 Force bitfield accesses to match their type width.
1589 Common Report Var(flag_store_merging) Optimization
1590 Merge adjacent stores.
1592 fguess-branch-probability
1593 Common Report Var(flag_guess_branch_prob) Optimization
1594 Enable guessing of branch probabilities.
1596 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1597 ; Generate position-independent code for executables if possible
1598 ; On SVR4 targets, it also controls whether or not to emit a
1599 ; string identifying the compiler.
1601 Common Report Var(flag_no_ident,0)
1602 Process #ident directives.
1605 Common Report Var(flag_if_conversion) Optimization
1606 Perform conversion of conditional jumps to branchless equivalents.
1609 Common Report Var(flag_if_conversion2) Optimization
1610 Perform conversion of conditional jumps to conditional execution.
1613 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1614 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1617 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1620 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1623 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1626 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1628 ftree-loop-if-convert
1629 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1630 Convert conditional jumps in innermost loops to branchless equivalents.
1632 ftree-loop-if-convert-stores
1634 Does nothing. Preserved for backward compatibility.
1636 ; -finhibit-size-directive inhibits output of .size for ELF.
1637 ; This is used only for compiling crtstuff.c,
1638 ; and it may be extended to other effects
1639 ; needed for crtstuff.c on other systems.
1640 finhibit-size-directive
1641 Common Report Var(flag_inhibit_size_directive)
1642 Do not generate .size directives.
1645 Common Report Var(flag_indirect_inlining) Optimization
1646 Perform indirect inlining.
1648 ; General flag to enable inlining. Specifying -fno-inline will disable
1649 ; all inlining apart from always-inline functions.
1651 Common Report Var(flag_no_inline,0) Init(0) Optimization
1652 Enable inlining of function declared \"inline\", disabling disables all inlining.
1654 finline-small-functions
1655 Common Report Var(flag_inline_small_functions) Optimization
1656 Integrate functions into their callers when code size is known not to grow.
1659 Common Report Var(flag_inline_functions) Optimization
1660 Integrate functions not declared \"inline\" into their callers when profitable.
1662 finline-functions-called-once
1663 Common Report Var(flag_inline_functions_called_once) Optimization
1664 Integrate functions only required by their single caller.
1667 Common RejectNegative Joined Alias(finline-limit=)
1670 Common RejectNegative Joined UInteger
1671 -finline-limit=<number> Limit the size of inlined functions to <number>.
1674 Common Report Var(flag_inline_atomics) Init(1) Optimization
1675 Inline __atomic operations when a lock free instruction sequence is available.
1678 Common RejectNegative Alias(fcf-protection=,full)
1681 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1682 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1683 instructions have valid targets.
1686 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1689 Enum(cf_protection_level) String(full) Value(CF_FULL)
1692 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1695 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1698 Enum(cf_protection_level) String(none) Value(CF_NONE)
1700 finstrument-functions
1701 Common Report Var(flag_instrument_function_entry_exit)
1702 Instrument function entry and exit with profiling calls.
1704 finstrument-functions-exclude-function-list=
1705 Common RejectNegative Joined
1706 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1708 finstrument-functions-exclude-file-list=
1709 Common RejectNegative Joined
1710 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1713 Common Report Var(flag_ipa_cp) Optimization
1714 Perform interprocedural constant propagation.
1717 Common Report Var(flag_ipa_cp_clone) Optimization
1718 Perform cloning to make Interprocedural constant propagation stronger.
1722 Does nothing. Preserved for backward compatibility.
1725 Common Report Var(flag_ipa_bit_cp) Optimization
1726 Perform interprocedural bitwise constant propagation.
1729 Common Report Var(flag_ipa_profile) Init(0) Optimization
1730 Perform interprocedural profile propagation.
1733 Common Report Var(flag_ipa_pta) Init(0) Optimization
1734 Perform interprocedural points-to analysis.
1737 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1738 Discover pure and const functions.
1741 Common Report Var(flag_ipa_icf) Optimization
1742 Perform Identical Code Folding for functions and read-only variables.
1745 Common Report Var(flag_ipa_icf_functions) Optimization
1746 Perform Identical Code Folding for functions.
1749 Common Report Var(flag_ipa_icf_variables) Optimization
1750 Perform Identical Code Folding for variables.
1753 Common Report Var(flag_ipa_reference) Init(0) Optimization
1754 Discover read-only and non addressable static variables.
1756 fipa-reference-addressable
1757 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1758 Discover read-only, write-only and non-addressable static variables.
1760 fipa-stack-alignment
1761 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1762 Reduce stack alignment on call sites if possible.
1766 Does nothing. Preserved for backward compatibility.
1770 Does nothing. Preserved for backward compatibility.
1773 Common Report Var(flag_ipa_vrp) Optimization
1774 Perform IPA Value Range Propagation.
1777 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1778 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1781 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1784 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1787 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1790 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1791 -fira-region=[one|all|mixed] Set regions for IRA.
1794 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1797 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1800 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1803 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1806 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1807 Use IRA based register pressure calculation
1808 in RTL hoist optimizations.
1811 Common Report Var(flag_ira_loop_pressure) Optimization
1812 Use IRA based register pressure calculation
1813 in RTL loop optimizations.
1815 fira-share-save-slots
1816 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1817 Share slots for saving different hard registers.
1819 fira-share-spill-slots
1820 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1821 Share stack slots for spilled pseudo-registers.
1824 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1825 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1828 Common Report Var(flag_ivopts) Init(1) Optimization
1829 Optimize induction variables on trees.
1832 Common Var(flag_jump_tables) Init(1) Optimization
1833 Use jump tables for sufficiently large switch statements.
1835 fkeep-inline-functions
1836 Common Report Var(flag_keep_inline_functions)
1837 Generate code for functions even if they are fully inlined.
1839 fkeep-static-functions
1840 Common Report Var(flag_keep_static_functions)
1841 Generate code for static functions even if they are never called.
1844 Common Report Var(flag_keep_static_consts) Init(1)
1845 Emit static const variables even if they are not used.
1848 Common Report Var(flag_leading_underscore) Init(-1)
1849 Give external symbols a leading underscore.
1853 Does nothing. Preserved for backward compatibility.
1856 Common Report Var(flag_lra_remat) Optimization
1857 Do CFG-sensitive rematerialization in LRA.
1861 Enable link-time optimization.
1864 Common RejectNegative Joined Var(flag_lto)
1865 Link-time optimization with number of parallel jobs or jobserver.
1868 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1871 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1874 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1877 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1880 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1883 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1886 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1887 Specify the algorithm to partition symbols and vars at linktime.
1889 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1890 flto-compression-level=
1891 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
1892 -flto-compression-level=<number> Use zlib/zstd compression level <number> for IL.
1894 flto-odr-type-merging
1896 Does nothing. Preserved for backward compatibility.
1899 Common Report Var(flag_lto_report) Init(0)
1900 Report various link-time optimization statistics.
1903 Common Report Var(flag_lto_report_wpa) Init(0)
1904 Report various link-time optimization statistics for WPA only.
1907 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1908 Set errno after built-in math functions.
1911 Common Joined RejectNegative UInteger Var(flag_max_errors)
1912 -fmax-errors=<number> Maximum number of errors to report.
1915 Common Report Var(mem_report)
1916 Report on permanent memory allocation.
1919 Common Report Var(mem_report_wpa)
1920 Report on permanent memory allocation in WPA only.
1922 ; This will attempt to merge constant section constants, if 1 only
1923 ; string constants and constants from constant pool, if 2 also constant
1925 fmerge-all-constants
1926 Common Report Var(flag_merge_constants,2) Init(1)
1927 Attempt to merge identical constants and constant variables.
1930 Common Report Var(flag_merge_constants,1)
1931 Attempt to merge identical constants across compilation units.
1933 fmerge-debug-strings
1934 Common Report Var(flag_merge_debug_strings) Init(1)
1935 Attempt to merge identical debug strings across compilation units.
1938 Common RejectNegative Joined UInteger
1939 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1942 Common Report Var(flag_modulo_sched) Optimization
1943 Perform SMS based modulo scheduling before the first scheduling pass.
1945 fmodulo-sched-allow-regmoves
1946 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1947 Perform SMS based modulo scheduling with register moves allowed.
1949 fmove-loop-invariants
1950 Common Report Var(flag_move_loop_invariants) Optimization
1951 Move loop invariant computations out of loops.
1954 Common Var(flag_dce) Init(1) Optimization
1955 Use the RTL dead code elimination pass.
1958 Common Var(flag_dse) Init(1) Optimization
1959 Use the RTL dead store elimination pass.
1961 freschedule-modulo-scheduled-loops
1962 Common Report Var(flag_resched_modulo_sched) Optimization
1963 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1965 fnon-call-exceptions
1966 Common Report Var(flag_non_call_exceptions) Optimization
1967 Support synchronous non-call exceptions.
1970 Common Driver Joined MissingArgError(options or targets missing after %qs)
1971 -foffload=<targets>=<options> Specify offloading targets and options for them.
1974 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1975 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1978 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1981 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1984 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1987 Common Report Var(flag_omit_frame_pointer) Optimization
1988 When possible do not generate stack frames.
1991 Common Report Var(flag_opt_info) Optimization
1992 Enable all optimization info dumps on stderr.
1995 Common Joined RejectNegative Var(common_deferred_options) Defer
1996 -fopt-info[-<type>=filename] Dump compiler optimization details.
1998 fsave-optimization-record
1999 Common Report Var(flag_save_optimization_record) Optimization
2000 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2002 foptimize-register-move
2004 Does nothing. Preserved for backward compatibility.
2006 foptimize-sibling-calls
2007 Common Report Var(flag_optimize_sibling_calls) Optimization
2008 Optimize sibling and tail recursive calls.
2011 Common Report Var(flag_partial_inlining) Optimization
2012 Perform partial inlining.
2015 Common Report Var(pre_ipa_mem_report)
2016 Report on memory allocation before interprocedural optimization.
2018 fpost-ipa-mem-report
2019 Common Report Var(post_ipa_mem_report)
2020 Report on memory allocation before interprocedural optimization.
2023 Common Report Var(flag_pack_struct) Optimization
2024 Pack structure members together without holes.
2027 Common RejectNegative Joined UInteger Optimization
2028 -fpack-struct=<number> Set initial maximum structure member alignment.
2031 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2032 Return small aggregates in memory, not registers.
2035 Common Report Var(flag_peel_loops) Optimization
2036 Perform loop peeling.
2039 Common Report Var(flag_no_peephole,0) Optimization
2040 Enable machine specific peephole optimizations.
2043 Common Report Var(flag_peephole2) Optimization
2044 Enable an RTL peephole pass before sched2.
2047 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2048 Generate position-independent code if possible (large mode).
2051 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2052 Generate position-independent code for executables if possible (large mode).
2055 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2056 Generate position-independent code if possible (small mode).
2059 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2060 Generate position-independent code for executables if possible (small mode).
2063 Common Report Var(flag_plt) Init(1) Optimization
2064 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2067 Common Joined RejectNegative Var(common_deferred_options) Defer
2068 Specify a plugin to load.
2071 Common Joined RejectNegative Var(common_deferred_options) Defer
2072 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2074 fpredictive-commoning
2075 Common Report Var(flag_predictive_commoning) Optimization
2076 Run predictive commoning optimization.
2078 fprefetch-loop-arrays
2079 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2080 Generate prefetch instructions, if available, for arrays in loops.
2083 Common Report Var(profile_flag)
2084 Enable basic program profiling code.
2087 Common Report Var(profile_abs_path_flag)
2088 Generate absolute source path names for gcov.
2091 Common Report Var(profile_arc_flag)
2092 Insert arc-based program profiling code.
2095 Common Joined RejectNegative Var(profile_data_prefix)
2096 Set the top-level directory for storing the profile data.
2097 The default is 'pwd'.
2100 Common Joined RejectNegative Var(profile_note_location)
2101 Select the name for storing the profile note file.
2104 Common Report Var(flag_profile_correction)
2105 Enable correction of flow inconsistent profile data input.
2108 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2109 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2111 fprofile-filter-files=
2112 Common Joined RejectNegative Var(flag_profile_filter_files)
2113 Instrument only functions from files where names match any regular expression (separated by a semi-colon).
2115 fprofile-exclude-files=
2116 Common Joined RejectNegative Var(flag_profile_exclude_files)
2117 Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon).
2120 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2123 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2126 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2129 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2133 Enable common options for generating profile info for profile feedback directed optimizations.
2136 Common Joined RejectNegative
2137 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2140 Common Var(flag_profile_use)
2141 Enable common options for performing profile feedback directed optimizations.
2144 Common Joined RejectNegative
2145 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2148 Common Report Var(flag_profile_values)
2149 Insert code to profile values of expressions.
2152 Common Report Var(profile_report)
2153 Report on consistency of profile.
2155 fprofile-reorder-functions
2156 Common Report Var(flag_profile_reorder_functions)
2157 Enable function reordering that improves code placement.
2159 fpatchable-function-entry=
2160 Common Joined Optimization
2161 Insert NOP instructions at each function entry.
2164 Common Var(common_deferred_options) Defer
2167 Common Joined RejectNegative Var(common_deferred_options) Defer
2168 -frandom-seed=<string> Make compile reproducible using <string>.
2170 ; This switch causes the command line that was used to create an
2171 ; object file to be recorded into the object file. The exact format
2172 ; of this recording is target and binary file format dependent.
2173 ; It is related to the -fverbose-asm switch, but that switch only
2174 ; records information in the assembler output file as comments, so
2175 ; they never reach the object file.
2176 frecord-gcc-switches
2177 Common Report Var(flag_record_gcc_switches)
2178 Record gcc command line switches in the object file.
2181 Common Report Var(flag_pcc_struct_return,0) Optimization
2182 Return small aggregates in registers.
2186 Does nothing. Preserved for backward compatibility.
2189 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2190 Tell DSE that the storage for a C++ object is dead when the constructor
2191 starts and when the destructor finishes.
2194 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2197 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2200 Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2201 -flive-patching=[inline-only-static|inline-clone] Control IPA
2202 optimizations to provide a safe compilation for live-patching. At the same
2203 time, provides multiple-level control on the enabled IPA optimizations.
2206 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2209 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2212 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2214 flive-range-shrinkage
2215 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2216 Relief of register pressure through live range shrinkage.
2219 Common Report Var(flag_rename_registers) Init(2) Optimization
2220 Perform a register renaming optimization pass.
2223 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2224 Perform a target dependent instruction fusion optimization pass.
2227 Common Report Var(flag_reorder_blocks) Optimization
2228 Reorder basic blocks to improve code placement.
2230 freorder-blocks-algorithm=
2231 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2232 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2235 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2238 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2241 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2243 freorder-blocks-and-partition
2244 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2245 Reorder basic blocks and partition into hot and cold sections.
2248 Common Report Var(flag_reorder_functions) Optimization
2249 Reorder functions to improve code placement.
2251 frerun-cse-after-loop
2252 Common Report Var(flag_rerun_cse_after_loop) Optimization
2253 Add a common subexpression elimination pass after loop optimizations.
2257 Does nothing. Preserved for backward compatibility.
2260 Common Report Var(flag_rounding_math) Optimization SetByCombined
2261 Disable optimizations that assume default FP rounding behavior.
2264 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2265 Enable scheduling across basic blocks.
2268 Common Report Var(flag_sched_pressure) Init(0) Optimization
2269 Enable register pressure sensitive insn scheduling.
2272 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2273 Allow speculative motion of non-loads.
2276 Common Report Var(flag_schedule_speculative_load) Optimization
2277 Allow speculative motion of some loads.
2279 fsched-spec-load-dangerous
2280 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2281 Allow speculative motion of more loads.
2284 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2285 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2287 fsched2-use-superblocks
2288 Common Report Var(flag_sched2_use_superblocks) Optimization
2289 If scheduling post reload, do superblock scheduling.
2293 Does nothing. Preserved for backward compatibility.
2296 Common Report Var(flag_schedule_insns) Optimization
2297 Reschedule instructions before register allocation.
2300 Common Report Var(flag_schedule_insns_after_reload) Optimization
2301 Reschedule instructions after register allocation.
2303 ; This flag should be on when a target implements non-trivial
2304 ; scheduling hooks, maybe saving some information for its own sake.
2305 ; On IA64, for example, this is used for correct bundling.
2306 fselective-scheduling
2307 Common Report Var(flag_selective_scheduling) Optimization
2308 Schedule instructions using selective scheduling algorithm.
2310 fselective-scheduling2
2311 Common Report Var(flag_selective_scheduling2) Optimization
2312 Run selective scheduling after reload.
2315 Common Undocumented Joined Var(flag_self_test)
2316 Run self-tests, using the given path to locate test files.
2318 fsel-sched-pipelining
2319 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2320 Perform software pipelining of inner loops during selective scheduling.
2322 fsel-sched-pipelining-outer-loops
2323 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2324 Perform software pipelining of outer loops during selective scheduling.
2326 fsel-sched-reschedule-pipelined
2327 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2328 Reschedule pipelined regions without pipelining.
2330 fsemantic-interposition
2331 Common Report Var(flag_semantic_interposition) Init(1)
2332 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2334 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2335 ; of stalled insns into the ready list.
2336 fsched-stalled-insns
2337 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2338 Allow premature scheduling of queued insns.
2340 fsched-stalled-insns=
2341 Common RejectNegative Joined UInteger Optimization
2342 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2344 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2345 ; be examined for a dependency on a stalled insn that is candidate for
2346 ; premature removal from the queue of stalled insns into the ready list (has
2347 ; an effect only if the flag 'sched_stalled_insns' is set).
2348 fsched-stalled-insns-dep
2349 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2350 Set dependence distance checking in premature scheduling of queued insns.
2352 fsched-stalled-insns-dep=
2353 Common RejectNegative Joined UInteger Optimization
2354 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2356 fsched-group-heuristic
2357 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2358 Enable the group heuristic in the scheduler.
2360 fsched-critical-path-heuristic
2361 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2362 Enable the critical path heuristic in the scheduler.
2364 fsched-spec-insn-heuristic
2365 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2366 Enable the speculative instruction heuristic in the scheduler.
2368 fsched-rank-heuristic
2369 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2370 Enable the rank heuristic in the scheduler.
2372 fsched-last-insn-heuristic
2373 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2374 Enable the last instruction heuristic in the scheduler.
2376 fsched-dep-count-heuristic
2377 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2378 Enable the dependent count heuristic in the scheduler.
2381 Common Report Var(flag_section_anchors) Optimization
2382 Access data in the same section from shared anchor points.
2386 Does nothing. Preserved for backward compatibility.
2390 Does nothing. Preserved for backward compatibility.
2393 Common Report Var(flag_ree) Init(0)
2394 Turn on Redundant Extensions Elimination pass.
2397 Common Report Var(flag_show_column) Init(1)
2398 Show column numbers in diagnostics, when available. Default on.
2401 Common Report Var(flag_shrink_wrap) Optimization
2402 Emit function prologues only before parts of the function that need it,
2403 rather than at the top of the function.
2405 fshrink-wrap-separate
2406 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2407 Shrink-wrap parts of the prologue and epilogue separately.
2410 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2411 Disable optimizations observable by IEEE signaling NaNs.
2414 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2415 Disable floating point optimizations that ignore the IEEE signedness of zero.
2417 fsingle-precision-constant
2418 Common Report Var(flag_single_precision_constant) Optimization
2419 Convert floating point constants to single precision constants.
2421 fsplit-ivs-in-unroller
2422 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2423 Split lifetimes of induction variables when loops are unrolled.
2426 Common Report Var(flag_split_stack) Init(-1)
2427 Generate discontiguous stack frames.
2430 Common Report Var(flag_split_wide_types) Optimization
2431 Split wide types into independent registers.
2434 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2435 Enable backward propagation of use properties at the SSA level.
2438 Common Report Var(flag_ssa_phiopt) Optimization
2439 Optimize conditional patterns using SSA PHI nodes.
2442 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2443 Optimize amount of stdarg registers saved to stack at start of function.
2445 fvariable-expansion-in-unroller
2446 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2447 Apply variable expansion when loops are unrolled.
2450 Common Report RejectNegative Joined Optimization
2451 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2454 Common Alias(fstack-check=, specific, no)
2455 Insert stack checking code into the program. Same as -fstack-check=specific.
2457 fstack-clash-protection
2458 Common Report Var(flag_stack_clash_protection) Optimization
2459 Insert code to probe each page of stack space as it is allocated to protect
2460 from stack-clash style attacks.
2463 Common Var(common_deferred_options) Defer
2465 fstack-limit-register=
2466 Common RejectNegative Joined Var(common_deferred_options) Defer
2467 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2469 fstack-limit-symbol=
2470 Common RejectNegative Joined Var(common_deferred_options) Defer
2471 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2474 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2475 Use propolice as a stack protection method.
2477 fstack-protector-all
2478 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2479 Use a stack protection method for every function.
2481 fstack-protector-strong
2482 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2483 Use a smart stack protection method for certain functions.
2485 fstack-protector-explicit
2486 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2487 Use stack protection method only for functions with the stack_protect attribute.
2490 Common RejectNegative Var(flag_stack_usage)
2491 Output stack usage information on a per-function basis.
2495 Does nothing. Preserved for backward compatibility.
2497 ; Nonzero if we should do (language-dependent) alias analysis.
2498 ; Typically, this analysis will assume that expressions of certain
2499 ; types do not alias expressions of certain other types. Only used
2500 ; if alias analysis (in general) is enabled.
2502 Common Report Var(flag_strict_aliasing) Optimization
2503 Assume strict aliasing rules apply.
2507 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2510 Common Report Var(flag_sync_libcalls) Init(1)
2511 Implement __atomic operations via libcalls to legacy __sync functions.
2514 Common Report Var(flag_syntax_only)
2515 Check for syntax errors, then stop.
2518 Common Report Var(flag_test_coverage)
2519 Create data files needed by \"gcov\".
2522 Common Report Var(flag_thread_jumps) Optimization
2523 Perform jump threading optimizations.
2526 Common Report Var(time_report)
2527 Report the time taken by each compiler pass.
2529 ftime-report-details
2530 Common Report Var(time_report_details)
2531 Record times taken by sub-phases separately.
2534 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2535 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2538 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2541 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2544 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2547 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2550 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2553 Common Report Var(flag_toplevel_reorder) Init(2)
2554 Reorder top level functions, variables, and asms.
2557 Common Report Var(flag_tracer) Optimization
2558 Perform superblock formation via tail duplication.
2561 Common Report Var(flag_trampolines) Init(0)
2562 For targets that normally need trampolines for nested functions, always
2563 generate them instead of using descriptors.
2565 ; Zero means that floating-point math operations cannot generate a
2566 ; (user-visible) trap. This is the case, for example, in nonstop
2567 ; IEEE 754 arithmetic.
2569 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2570 Assume floating-point operations can trap.
2573 Common Report Var(flag_trapv) Optimization
2574 Trap for signed overflow in addition, subtraction and multiplication.
2577 Common Report Var(flag_tree_ccp) Optimization
2578 Enable SSA-CCP optimization on trees.
2581 Common Report Var(flag_tree_bit_ccp) Optimization
2582 Enable SSA-BIT-CCP optimization on trees.
2586 Does nothing. Preserved for backward compatibility.
2589 Common Report Var(flag_tree_ch) Optimization
2590 Enable loop header copying on trees.
2592 ftree-coalesce-inlined-vars
2593 Common Ignore RejectNegative
2594 Does nothing. Preserved for backward compatibility.
2597 Common Report Var(flag_tree_coalesce_vars) Optimization
2598 Enable SSA coalescing of user variables.
2602 Does nothing. Preserved for backward compatibility.
2605 Common Report Var(flag_tree_copy_prop) Optimization
2606 Enable copy propagation on trees.
2608 ftree-store-copy-prop
2610 Does nothing. Preserved for backward compatibility.
2613 Common Report Var(flag_tree_cselim) Init(2) Optimization
2614 Transform condition stores into unconditional ones.
2616 ftree-switch-conversion
2617 Common Report Var(flag_tree_switch_conversion) Optimization
2618 Perform conversions of switch initializations.
2621 Common Report Var(flag_tree_dce) Optimization
2622 Enable SSA dead code elimination optimization on trees.
2624 ftree-dominator-opts
2625 Common Report Var(flag_tree_dom) Optimization
2626 Enable dominator optimizations.
2629 Common Report Var(flag_tree_tail_merge) Optimization
2630 Enable tail merging on trees.
2633 Common Report Var(flag_tree_dse) Optimization
2634 Enable dead store elimination.
2637 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2638 Enable forward propagation on trees.
2641 Common Report Var(flag_tree_fre) Optimization
2642 Enable Full Redundancy Elimination (FRE) on trees.
2645 Common Report Var(flag_optimize_strlen) Optimization
2646 Enable string length optimizations on trees.
2648 fisolate-erroneous-paths-dereference
2649 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2650 Detect paths that trigger erroneous or undefined behavior due to
2651 dereferencing a null pointer. Isolate those paths from the main control
2652 flow and turn the statement with erroneous or undefined behavior into a trap.
2654 fisolate-erroneous-paths-attribute
2655 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2656 Detect paths that trigger erroneous or undefined behavior due to a null value
2657 being used in a way forbidden by a returns_nonnull or nonnull
2658 attribute. Isolate those paths from the main control flow and turn the
2659 statement with erroneous or undefined behavior into a trap.
2661 ftree-loop-distribution
2662 Common Report Var(flag_tree_loop_distribution) Optimization
2663 Enable loop distribution on trees.
2665 ftree-loop-distribute-patterns
2666 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2667 Enable loop distribution for patterns transformed into a library call.
2670 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2671 Enable loop invariant motion on trees.
2674 Common Alias(floop-nest-optimize)
2675 Enable loop nest transforms. Same as -floop-nest-optimize.
2678 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2679 Create canonical induction variables in loops.
2682 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2683 Enable loop optimizations on tree level.
2685 ftree-parallelize-loops=
2686 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2687 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2690 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2691 Enable hoisting loads from conditional pointers.
2694 Common Report Var(flag_tree_pre) Optimization
2695 Enable SSA-PRE optimization on trees.
2698 Common Report Var(flag_tree_partial_pre) Optimization
2699 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2702 Common Report Var(flag_tree_pta) Optimization
2703 Perform function-local points-to analysis on trees.
2706 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2707 Enable reassociation on tree level.
2711 Does nothing. Preserved for backward compatibility.
2714 Common Report Var(flag_tree_sink) Optimization
2715 Enable SSA code sinking on trees.
2718 Common Report Var(flag_tree_slsr) Optimization
2719 Perform straight-line strength reduction.
2722 Common Report Var(flag_tree_sra) Optimization
2723 Perform scalar replacement of aggregates.
2726 Common Report Var(flag_tree_ter) Optimization
2727 Replace temporary expressions in the SSA->normal pass.
2730 Common Report Var(flag_tree_live_range_split) Optimization
2731 Perform live range splitting during the SSA->normal pass.
2734 Common Report Var(flag_tree_vrp) Init(0) Optimization
2735 Perform Value Range Propagation on trees.
2738 Common Report Var(flag_split_paths) Init(0) Optimization
2739 Split paths leading to loop backedges.
2741 funconstrained-commons
2742 Common Var(flag_unconstrained_commons) Optimization
2743 Assume common declarations may be overridden with ones with a larger
2747 Common Report Var(flag_unit_at_a_time) Init(1)
2748 Compile whole compilation unit at a time.
2751 Common Report Var(flag_unroll_loops) Optimization
2752 Perform loop unrolling when iteration count is known.
2755 Common Report Var(flag_unroll_all_loops) Optimization
2756 Perform loop unrolling for all loops.
2758 ; Nonzero means that loop optimizer may assume that the induction variables
2759 ; that control loops do not overflow and that the loops with nontrivial
2760 ; exit condition are not infinite
2761 funsafe-loop-optimizations
2763 Does nothing. Preserved for backward compatibility.
2766 Common Report Var(flag_associative_math) SetByCombined Optimization
2767 Allow optimization for floating-point arithmetic which may change the
2768 result of the operation due to rounding.
2771 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2772 Same as -fassociative-math for expressions which include division.
2774 ; Nonzero means that unsafe floating-point math optimizations are allowed
2775 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2776 ; are allowed to assume that their arguments and results are "normal"
2777 ; (e.g., nonnegative for SQRT).
2778 funsafe-math-optimizations
2779 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2780 Allow math optimizations that may violate IEEE or ISO standards.
2783 Common Report Var(flag_unswitch_loops) Optimization
2784 Perform loop unswitching.
2787 Common Report Var(flag_split_loops) Optimization
2788 Perform loop splitting.
2790 fversion-loops-for-strides
2791 Common Report Var(flag_version_loops_for_strides) Optimization
2792 Version loops based on whether indices have a stride of one.
2795 Common Report Var(flag_unwind_tables) Optimization
2796 Just generate unwind tables for exception handling.
2799 Common Driver Negative(fuse-ld=gold)
2800 Use the bfd linker instead of the default linker.
2803 Common Driver Negative(fuse-ld=bfd)
2804 Use the gold linker instead of the default linker.
2807 Common Driver Negative(fuse-ld=lld)
2808 Use the lld LLVM linker instead of the default linker.
2811 Common Undocumented Var(flag_use_linker_plugin)
2813 ; Positive if we should track variables, negative if we should run
2814 ; the var-tracking pass only to discard debug annotations, zero if
2815 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2816 ; will be set according to optimize, debug_info_level and debug_hooks
2817 ; in process_options ().
2819 Common Report Var(flag_var_tracking) Init(2) PerFunction
2820 Perform variable tracking.
2822 ; Positive if we should track variables at assignments, negative if
2823 ; we should run the var-tracking pass only to discard debug
2824 ; annotations. When flag_var_tracking_assignments ==
2825 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2826 fvar-tracking-assignments
2827 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2828 Perform variable tracking by annotating assignments.
2830 ; Nonzero if we should toggle flag_var_tracking_assignments after
2831 ; processing options and computing its default. */
2832 fvar-tracking-assignments-toggle
2833 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2834 Toggle -fvar-tracking-assignments.
2836 ; Positive if we should track uninitialized variables, negative if
2837 ; we should run the var-tracking pass only to discard debug
2838 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2839 ; will be set according to flag_var_tracking.
2840 fvar-tracking-uninit
2841 Common Report Var(flag_var_tracking_uninit) PerFunction
2842 Perform variable tracking and also tag variables that are uninitialized.
2844 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2846 Common Report Optimization
2847 Enable vectorization on trees.
2849 ftree-vectorizer-verbose=
2850 Common Joined RejectNegative Ignore
2851 Does nothing. Preserved for backward compatibility.
2853 ftree-loop-vectorize
2854 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2855 Enable loop vectorization on trees.
2858 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2859 Enable basic block vectorization (SLP) on trees.
2862 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2863 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2866 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2867 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2870 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2873 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2876 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2879 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2882 Common Alias(fvect-cost-model=,dynamic,unlimited)
2883 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2885 ftree-vect-loop-version
2887 Does nothing. Preserved for backward compatibility.
2890 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2891 Enable copy propagation of scalar-evolution information.
2893 ; -fverbose-asm causes extra commentary information to be produced in
2894 ; the generated assembly code (to make it more readable). This option
2895 ; is generally only of use to those who actually need to read the
2896 ; generated assembly code (perhaps while debugging the compiler itself).
2897 ; -fno-verbose-asm, the default, causes the extra information
2898 ; to not be added and is useful when comparing two assembler files.
2900 Common Report Var(flag_verbose_asm)
2901 Add extra commentary to assembler output.
2904 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2905 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2908 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2911 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2914 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2917 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2920 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2923 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2924 Validate vtable pointers before using them.
2927 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2930 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2933 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2936 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2939 Common Var(flag_vtv_counts)
2940 Output vtable verification counters.
2943 Common Var(flag_vtv_debug)
2944 Output vtable verification pointer sets information.
2947 Common Report Var(flag_value_profile_transformations) Optimization
2948 Use expression value profiles in optimizations.
2951 Common Report Var(flag_web) Init(2) Optimization
2952 Construct webs and split unrelated uses of single variable.
2954 ftree-builtin-call-dce
2955 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2956 Enable conditional dead code elimination for builtin calls.
2959 Common Report Var(flag_whole_program) Init(0)
2960 Perform whole program optimizations.
2963 Common Report Var(flag_wrapv_pointer) Optimization
2964 Assume pointer overflow wraps around.
2967 Common Report Var(flag_wrapv) Optimization
2968 Assume signed arithmetic overflow wraps around.
2970 fzero-initialized-in-bss
2971 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2972 Put zero initialized data in the bss section.
2975 Common Driver RejectNegative JoinedOrMissing
2976 Generate debug information in default format.
2979 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2980 Assume assembler support for (DWARF2+) .loc directives.
2983 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2984 Assume assembler support for view in (DWARF2+) .loc directives.
2987 Common Driver Deprecated
2988 Does nothing. Preserved for backward compatibility.
2991 Common Driver Deprecated
2992 Does nothing. Preserved for backward compatibility.
2995 Common Driver Deprecated
2996 Does nothing. Preserved for backward compatibility.
2999 Common Driver Deprecated
3000 Does nothing. Preserved for backward compatibility.
3003 Common Driver Var(debug_column_info,1) Init(1)
3004 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3007 Common Driver JoinedOrMissing Negative(gdwarf-)
3008 Generate debug information in default version of DWARF format.
3011 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
3012 Generate debug information in DWARF v2 (or later) format.
3015 Common Driver JoinedOrMissing
3016 Generate debug information in default extended format.
3019 Common Driver Var(debug_inline_points) Init(2)
3020 Generate extended entry point information for inlined functions.
3022 ginternal-reset-location-views
3023 Common Driver Var(debug_internal_reset_location_views) Init(2)
3024 Compute locview reset points based on insn length estimates.
3027 RejectNegative Joined Undocumented
3028 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3031 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3032 Don't generate DWARF pubnames and pubtypes sections.
3035 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3036 Generate DWARF pubnames and pubtypes sections.
3039 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3040 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3042 grecord-gcc-switches
3043 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3044 Record gcc command line switches in DWARF DW_AT_producer.
3047 Common Driver Var(dwarf_split_debug_info) Init(0)
3048 Generate debug information in separate .dwo files.
3051 Common Driver JoinedOrMissing Negative(gstabs+)
3052 Generate debug information in STABS format.
3055 Common Driver JoinedOrMissing Negative(gvms)
3056 Generate debug information in extended STABS format.
3058 gstatement-frontiers
3059 Common Driver Var(debug_nonbind_markers_p) Init(2)
3060 Emit progressive recommended breakpoint locations.
3063 Common Driver Report Var(dwarf_strict) Init(0)
3064 Don't emit DWARF additions beyond selected version.
3067 Common Driver Report Var(flag_describe_dies) Init(0)
3068 Add description attributes to some DWARF DIEs that have no name attribute.
3071 Common Driver Report Var(flag_gtoggle)
3072 Toggle debug information generation.
3074 gvariable-location-views
3075 Common Driver Var(debug_variable_location_views, 1) Init(2)
3076 Augment variable location lists with progressive views.
3078 gvariable-location-views=incompat5
3079 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3082 Common Driver JoinedOrMissing Negative(gxcoff)
3083 Generate debug information in VMS format.
3086 Common Driver JoinedOrMissing Negative(gxcoff+)
3087 Generate debug information in XCOFF format.
3090 Common Driver JoinedOrMissing Negative(gdwarf)
3091 Generate debug information in extended XCOFF format.
3094 Name(compressed_debug_sections) Type(int)
3096 ; Since -gz= is completely handled in specs, the values aren't used and we
3097 ; assign arbitrary constants.
3099 Enum(compressed_debug_sections) String(none) Value(0)
3102 Enum(compressed_debug_sections) String(zlib) Value(1)
3105 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3109 Generate compressed debug sections.
3112 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3113 -gz=<format> Generate compressed debug sections in format <format>.
3116 Driver Joined Separate
3119 Common Joined Var(plugindir_string) Init(0)
3120 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3123 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3124 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3127 Driver Joined Separate
3132 no-canonical-prefixes
3148 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3149 -o <file> Place output into <file>.
3152 Common Var(profile_flag)
3153 Enable function profiling.
3156 Driver Var(pass_exit_codes)
3159 Common Alias(Wpedantic)
3162 Common Var(flag_pedantic_errors)
3163 Like -pedantic but issue them as errors.
3169 Driver Var(use_pipes)
3172 Driver JoinedOrMissing Var(print_file_name)
3174 print-libgcc-file-name
3177 print-multi-directory
3178 Driver Var(print_multi_directory)
3181 Driver Var(print_multi_lib)
3183 print-multi-os-directory
3184 Driver Var(print_multi_os_directory)
3187 Driver Var(print_multiarch)
3190 Driver JoinedOrMissing Var(print_prog_name)
3193 Driver Var(print_search_dirs)
3196 Driver Var(print_sysroot)
3198 print-sysroot-headers-suffix
3199 Driver Var(print_sysroot_headers_suffix)
3202 Common Var(quiet_flag) RejectDriver
3203 Do not display functions compiled or elapsed time.
3221 Driver Var(report_times)
3224 Driver JoinedOrMissing
3227 Driver Joined Separate
3231 ; C option, but driver must not handle as "-u ndef".
3234 Common Driver Var(verbose_flag)
3235 Enable verbose output.
3238 Common Var(version_flag) RejectDriver
3239 Display the compiler's version.
3242 Common Var(inhibit_warnings)
3246 Driver Separate Var(wrapper_string)
3249 Driver Joined Separate
3252 Driver RejectNegative Negative(static-pie)
3253 Create a shared library.
3259 Driver Separate Alias(specs=)
3272 ; Documented for Fortran, but always accepted by driver.
3279 ; Documented for Go, but always accepted by driver.
3297 Driver RejectNegative Negative(shared)
3298 Don't create a dynamically linked position independent executable.
3301 Driver RejectNegative Negative(no-pie)
3302 Create a dynamically linked position independent executable.
3305 Driver RejectNegative Negative(pie)
3306 Create a static position independent executable.
3309 Driver Joined Separate
3312 Common Report Var(flag_ipa_ra) Optimization
3313 Use caller save register across calls if possible.
3315 ; This comment is to ensure we retain the blank line above.