1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2018 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 Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
555 Warn about type safety and similar errors and mismatches in attribute alias and related.
558 Common Alias(Wattribute_alias=, 0, 0) Warning
559 Disable -Wattribute-alias.
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.
582 Wdeprecated-declarations
583 Common Var(warn_deprecated_decl) Init(1) Warning
584 Warn about uses of __attribute__((deprecated)) declarations.
586 Wdisabled-optimization
587 Common Var(warn_disabled_optimization) Warning
588 Warn when an optimization pass is disabled.
591 Common Var(warnings_are_errors)
592 Treat all warnings as errors.
596 Treat specified warning as error.
599 Common Var(extra_warnings) Warning
600 Print extra (possibly unwanted) warnings.
603 Common Var(flag_fatal_errors)
604 Exit on the first error occurred.
607 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
608 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
611 Common Var(warn_free_nonheap_object) Init(1) Warning
612 Warn when attempting to free a non-heap object.
615 Common Var(warn_hsa) Init(1) Warning
616 Warn when a function cannot be expanded to HSAIL.
618 Wimplicit-fallthrough
619 Common Alias(Wimplicit-fallthrough=,3,0) Warning
621 Wimplicit-fallthrough=
622 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
623 Warn when a switch case falls through.
626 Common Var(warn_inline) Warning
627 Warn when an inlined function cannot be inlined.
629 Winvalid-memory-model
630 Common Var(warn_invalid_memory_model) Init(1) Warning
631 Warn when an atomic memory model parameter is known to be outside the valid range.
634 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
637 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
638 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
641 Var(warn_nonnull_compare) Warning
642 Warn if comparing pointer parameter with nonnull attribute with NULL.
645 Common Var(warn_null_dereference) Warning
646 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
648 Wunsafe-loop-optimizations
649 Common Ignore Warning
650 Does nothing. Preserved for backward compatibility.
653 Common Warning Alias(Wsuggest-attribute=noreturn)
656 Common Var(warn_odr_violations) Init(1) Warning
657 Warn about some C++ One Definition Rule violations during link time optimization.
660 Common Var(warn_overflow) Init(1) Warning
661 Warn about overflow in arithmetic expressions.
664 Common Var(warn_lto_type_mismatch) Init(1) Warning
665 During link time optimization warn about mismatched types of global declarations.
668 Common Var(warn_packed) Warning
669 Warn when the packed attribute has no effect on struct layout.
672 Common Var(warn_padded) Warning
673 Warn when padding is required to align structure members.
676 Common Var(pedantic) Init(0) Warning
677 Issue warnings needed for strict compliance to the standard.
680 Common Var(warn_return_local_addr) Init(1) Warning
681 Warn about returning a pointer/reference to a local or temporary variable.
684 Common Var(warn_shadow) Warning
685 Warn when one variable shadows another. Same as -Wshadow=global.
688 Common Warning Alias(Wshadow)
689 Warn when one variable shadows another (globally).
692 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
693 Warn when one local variable shadows another local variable or parameter.
696 Common Warning Undocumented Alias(Wshadow=local)
698 Wshadow=compatible-local
699 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
700 Warn when one local variable shadows another local variable or parameter of compatible type.
702 Wshadow-compatible-local
703 Common Warning Undocumented Alias(Wshadow=compatible-local)
706 Common Var(warn_stack_protect) Warning
707 Warn when not issuing stack smashing protection for some reason.
710 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
711 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
715 Warn about code which might break strict aliasing rules.
718 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
719 Warn about code which might break strict aliasing rules.
723 Warn about optimizations that assume that signed overflow is undefined.
726 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
727 Warn about optimizations that assume that signed overflow is undefined.
729 Wsuggest-attribute=cold
730 Common Var(warn_suggest_attribute_cold) Warning
731 Warn about functions which might be candidates for __attribute__((cold)).
733 Wsuggest-attribute=const
734 Common Var(warn_suggest_attribute_const) Warning
735 Warn about functions which might be candidates for __attribute__((const)).
737 Wsuggest-attribute=pure
738 Common Var(warn_suggest_attribute_pure) Warning
739 Warn about functions which might be candidates for __attribute__((pure)).
741 Wsuggest-attribute=noreturn
742 Common Var(warn_suggest_attribute_noreturn) Warning
743 Warn about functions which might be candidates for __attribute__((noreturn)).
745 Wsuggest-attribute=malloc
746 Common Var(warn_suggest_attribute_malloc) Warning
747 Warn about functions which might be candidates for __attribute__((malloc)).
750 Common Var(warn_suggest_final_types) Warning
751 Warn about C++ polymorphic types where adding final keyword would improve code quality.
753 Wsuggest-final-methods
754 Common Var(warn_suggest_final_methods) Warning
755 Warn about C++ virtual methods where adding final keyword would improve code quality.
758 Common Var(warn_switch_unreachable) Warning Init(1)
759 Warn about statements between switch's controlling expression and the first
763 Common Var(warn_system_headers) Warning
764 Do not suppress warnings from system headers.
767 Common Var(warn_trampolines) Warning
768 Warn whenever a trampoline is generated.
771 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
772 Warn if a comparison is always true or always false due to the limited range of the data type.
775 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
776 Warn about uninitialized automatic variables.
779 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
780 Warn about maybe uninitialized automatic variables.
783 Common Ignore Warning
784 Does nothing. Preserved for backward compatibility.
787 Common Var(warn_unused) Init(0) Warning
788 Enable all -Wunused- warnings.
790 Wunused-but-set-parameter
791 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
792 Warn when a function parameter is only set, otherwise unused.
794 Wunused-but-set-variable
795 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
796 Warn when a variable is only set, otherwise unused.
799 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
800 Warn when a function is unused.
803 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
804 Warn when a label is unused.
807 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
808 Warn when a function parameter is unused.
811 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
812 Warn when an expression value is unused.
815 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
816 Warn when a variable is unused.
819 Common Var(warn_coverage_mismatch) Init(1) Warning
820 Warn in case profiles in -fprofile-use do not match.
823 Common Var(warn_missing_profile) Init(1) Warning
824 Warn in case profiles in -fprofile-use do not exist.
826 Wvector-operation-performance
827 Common Var(warn_vector_operation_performance) Warning
828 Warn when a vector operation is compiled outside the SIMD.
843 Common Separate Var(aux_info_file_name)
844 -aux-info <file> Emit declaration information into <file>.
847 Common Joined Alias(aux-info)
850 Common Separate RejectDriver Var(aux_base_name)
853 Common Separate RejectDriver
863 -d<letters> Enable dumps from specific passes of the compiler.
866 Common Separate Var(dump_base_name)
867 -dumpbase <file> Set the file basename to be used for dumps.
870 Common Separate Var(dump_dir_name)
871 -dumpdir <dir> Set the directory name to be used for dumps.
886 Driver Joined Separate
888 ; This option has historically been passed down to the linker by an
889 ; accident of a %{e*} spec, so ensure it continues to be passed down
890 ; as a single option. The supported option for this purpose is
891 ; -rdynamic. See PR 47390.
895 ; The version of the C++ ABI in use. The following values are allowed:
897 ; 0: The version of the ABI believed most conformant with the C++ ABI
898 ; specification. This ABI may change as bugs are discovered and fixed.
899 ; Therefore, 0 will not necessarily indicate the same ABI in different
902 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
904 ; 2: The version of the ABI first used in G++ 3.4, and the default
907 ; 3: The version of the ABI that fixes the missing underscore
908 ; in template non-type arguments of pointer type.
910 ; 4: The version of the ABI that introduces unambiguous mangling of
911 ; vector types. First selectable in G++ 4.5.
913 ; 5: The version of the ABI that ignores attribute const/noreturn
914 ; in function pointer mangling, and corrects mangling of decltype and
915 ; function parameters used in other parameters and the return type.
916 ; First selectable in G++ 4.6.
918 ; 6: The version of the ABI that doesn't promote scoped enums to int and
919 ; changes the mangling of template argument packs, const/static_cast,
920 ; prefix ++ and --, and a class scope function used as a template
922 ; First selectable in G++ 4.7.
924 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
925 ; corrects the mangling of lambdas in default argument scope.
926 ; First selectable in G++ 4.8.
928 ; 8: The version of the ABI that corrects the substitution behavior of
929 ; function types with function-cv-qualifiers.
930 ; First selectable in G++ 4.9 and default in G++ 5.
932 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
933 ; First selectable and default in G++ 5.2.
935 ; 10: The version of the ABI that mangles attributes that affect type
936 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
937 ; Default in G++ 6 (set in c_common_post_options).
939 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
940 ; and introduces new inheriting constructor handling.
943 ; 12: Corrects the calling convention for classes with only deleted copy/move
944 ; constructors and changes passing/returning of empty records.
945 ; Default in G++ 8.1.
947 ; 13: Fixes the accidental change in 12 to the calling convention for classes
948 ; with deleted copy constructor and trivial move constructor.
949 ; Default in G++ 8.2.
951 ; Additional positive integers will be assigned as new versions of
952 ; the ABI become the default version of the ABI.
954 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
955 The version of the C++ ABI in use.
957 faggressive-loop-optimizations
958 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
959 Aggressively optimize loops using language constraints.
962 Common Report Var(flag_align_functions) Optimization
963 Align the start of functions.
966 Common RejectNegative Joined Var(str_align_functions) Optimization
968 flimit-function-alignment
969 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
972 Common Report Var(flag_align_jumps) Optimization
973 Align labels which are only reached by jumping.
976 Common RejectNegative Joined Var(str_align_jumps) Optimization
979 Common Report Var(flag_align_labels) Optimization
983 Common RejectNegative Joined Var(str_align_labels) Optimization
986 Common Report Var(flag_align_loops) Optimization
987 Align the start of loops.
990 Common RejectNegative Joined Var(str_align_loops) Optimization
994 Does nothing. Preserved for backward compatibility.
998 Does nothing. Preserved for backward compatibility.
1000 fargument-noalias-global
1002 Does nothing. Preserved for backward compatibility.
1004 fargument-noalias-anything
1006 Does nothing. Preserved for backward compatibility.
1009 Common Driver Report Joined
1010 Select what to sanitize.
1013 Common Report Joined
1014 Select type of coverage sanitization.
1016 fasan-shadow-offset=
1017 Common Joined RejectNegative Var(common_deferred_options) Defer
1018 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1021 Common Joined RejectNegative Var(common_deferred_options) Defer
1022 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1023 in user-defined sections.
1026 Common Report Joined
1027 After diagnosing undefined behavior attempt to continue execution.
1031 This switch is deprecated; use -fsanitize-recover= instead.
1033 fsanitize-address-use-after-scope
1034 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1036 fsanitize-undefined-trap-on-error
1037 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1038 Use trap instead of a library function for undefined behavior sanitization.
1040 fasynchronous-unwind-tables
1041 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1042 Generate unwind tables that are exact at each instruction boundary.
1045 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1046 Generate auto-inc/dec instructions.
1049 Common Report Var(flag_auto_profile)
1050 Use sample profile information for call graph node weights. The default
1051 profile file is fbdata.afdo in 'pwd'.
1054 Common Joined RejectNegative Var(auto_profile_file)
1055 Use sample profile information for call graph node weights. The profile
1056 file is specified in the argument.
1058 ; -fcheck-bounds causes gcc to generate array bounds checks.
1059 ; For C, C++ and ObjC: defaults off.
1060 ; For Java: defaults to on.
1061 ; For Fortran: defaults to off.
1063 Common Report Var(flag_bounds_check)
1064 Generate code to check bounds before indexing arrays.
1067 Common Report Var(flag_branch_on_count_reg) Optimization
1068 Replace add, compare, branch with branch on count register.
1070 fbranch-probabilities
1071 Common Report Var(flag_branch_probabilities) Optimization
1072 Use profiling information for branch probabilities.
1074 fbranch-target-load-optimize
1075 Common Report Var(flag_branch_target_load_optimize) Optimization
1076 Perform branch target load optimization before prologue / epilogue threading.
1078 fbranch-target-load-optimize2
1079 Common Report Var(flag_branch_target_load_optimize2) Optimization
1080 Perform branch target load optimization after prologue / epilogue threading.
1083 Common Report Var(flag_btr_bb_exclusive) Optimization
1084 Restrict target load migration not to re-use registers in any basic block.
1087 Common Joined RejectNegative Var(common_deferred_options) Defer
1088 -fcall-saved-<register> Mark <register> as being preserved across functions.
1091 Common Joined RejectNegative Var(common_deferred_options) Defer
1092 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1094 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1095 ; be saved across function calls, if that produces overall better code.
1096 ; Optional now, so people can test it.
1098 Common Report Var(flag_caller_saves) Optimization
1099 Save registers around function calls.
1103 This switch is deprecated; do not use.
1106 Common Var(flag_check_new)
1107 Check the return value of new in C++.
1110 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1111 Perform internal consistency checkings.
1114 Common Joined RejectNegative UInteger Var(flag_checking)
1115 Perform internal consistency checkings.
1118 Common Report Var(flag_code_hoisting) Optimization
1119 Enable code hoisting.
1121 fcombine-stack-adjustments
1122 Common Report Var(flag_combine_stack_adjustments) Optimization
1123 Looks for opportunities to reduce stack adjustments and stack references.
1126 Common Report Var(flag_no_common,0)
1127 Do not put uninitialized globals in the common section.
1131 ; Converted by the driver to -fcompare-debug= options.
1134 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1135 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1137 fcompare-debug-second
1138 Common Driver RejectNegative Var(flag_compare_debug)
1139 Run only the second compilation of -fcompare-debug.
1142 Common Report Var(flag_compare_elim_after_reload) Optimization
1143 Perform comparison elimination after register allocation has finished.
1146 Common Var(flag_conserve_stack) Optimization
1147 Do not perform optimizations increasing noticeably stack usage.
1150 Common Report Var(flag_cprop_registers) Optimization
1151 Perform a register copy-propagation optimization pass.
1154 Common Report Var(flag_crossjumping) Optimization
1155 Perform cross-jumping optimization.
1158 Common Report Var(flag_cse_follow_jumps) Optimization
1159 When running CSE, follow jumps to their targets.
1163 Does nothing. Preserved for backward compatibility.
1166 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1167 Omit range reduction step when performing complex division.
1170 Common Report Var(flag_cx_fortran_rules) Optimization
1171 Complex multiplication and division follow Fortran rules.
1174 Common Report Var(flag_data_sections)
1175 Place data items into their own section.
1178 Common Report Var(common_deferred_options) Defer
1179 List all available debugging counters with their limits and counts.
1182 Common RejectNegative Joined Var(common_deferred_options) Defer
1183 -fdbg-cnt=<counter>[:<lower_limit>]:<upper_limit>[,<counter>:...] Set the debug counter limit.
1186 Common Joined RejectNegative Var(common_deferred_options) Defer
1187 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1190 Common Joined RejectNegative Var(common_deferred_options) Defer
1191 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1193 fdebug-types-section
1194 Common Report Var(flag_debug_types_section) Init(0)
1195 Output .debug_types section when using DWARF v4 debuginfo.
1197 ; Nonzero for -fdefer-pop: don't pop args after each function call
1198 ; instead save them up to pop many calls' args with one insns.
1200 Common Report Var(flag_defer_pop) Optimization
1201 Defer popping functions args from stack until later.
1204 Common Report Var(flag_delayed_branch) Optimization
1205 Attempt to fill delay slots of branch instructions.
1207 fdelete-dead-exceptions
1208 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1209 Delete dead instructions that may throw exceptions.
1211 fdelete-null-pointer-checks
1212 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1213 Delete useless null pointer checks.
1215 fdevirtualize-at-ltrans
1216 Common Report Var(flag_ltrans_devirtualize)
1217 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1219 fdevirtualize-speculatively
1220 Common Report Var(flag_devirtualize_speculatively) Optimization
1221 Perform speculative devirtualization.
1224 Common Report Var(flag_devirtualize) Optimization
1225 Try to convert virtual calls to direct ones.
1227 fdiagnostics-show-location=
1228 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1229 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1231 ; Required for these enum values.
1236 Name(diagnostic_prefixing_rule) Type(int)
1239 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1242 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1244 fdiagnostics-show-caret
1245 Common Var(flag_diagnostics_show_caret) Init(1)
1246 Show the source line with a caret indicating the column.
1248 fdiagnostics-show-labels
1249 Common Var(flag_diagnostics_show_labels) Init(1)
1250 Show labels annotating ranges of source code when showing source
1252 fdiagnostics-show-line-numbers
1253 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1254 Show line numbers in the left margin when showing source
1257 Common Alias(fdiagnostics-color=,always,never)
1261 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1262 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1264 ; Required for these enum values.
1269 Name(diagnostic_color_rule) Type(int)
1272 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1275 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1278 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1280 fdiagnostics-format=
1281 Common Joined RejectNegative Enum(diagnostics_output_format)
1282 -fdiagnostics-format=[text|json] Select output format
1284 ; Required for these enum values.
1289 Name(diagnostics_output_format) Type(int)
1292 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1295 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON)
1297 fdiagnostics-parseable-fixits
1298 Common Var(flag_diagnostics_parseable_fixits)
1299 Print fix-it hints in machine-readable form.
1301 fdiagnostics-generate-patch
1302 Common Var(flag_diagnostics_generate_patch)
1303 Print fix-it hints to stderr in unified diff format.
1305 fdiagnostics-show-option
1306 Common Var(flag_diagnostics_show_option) Init(1)
1307 Amend appropriate diagnostic messages with the command line option that controls them.
1309 fdiagnostics-minimum-margin-width=
1310 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1311 Set minimum width of left margin of source code when showing source
1314 Common Joined RejectNegative Var(common_deferred_options) Defer
1315 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1318 Common Joined RejectNegative Var(common_deferred_options) Defer
1319 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1322 Common Joined RejectNegative Var(common_deferred_options) Defer
1323 -fdump-<type> Dump various compiler internals to a file.
1326 Driver RejectNegative
1329 Common RejectNegative Joined Var(flag_dump_final_insns)
1330 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1333 Common RejectNegative Joined Var(flag_dump_go_spec)
1334 -fdump-go-spec=filename Write all declarations to file as Go code.
1337 Common Report Var(flag_dump_noaddr)
1338 Suppress output of addresses in debugging dumps.
1341 Common Driver Var(flag_report_bug)
1342 Collect and dump debug information into temporary file if ICE in C/C++
1345 fdump-internal-locations
1346 Common Var(flag_dump_locations) Init(0)
1347 Dump detailed information on GCC's internal representation of source code locations.
1350 Common Var(flag_dump_passes) Init(0)
1351 Dump optimization passes.
1354 Common Report Var(flag_dump_unnumbered)
1355 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1357 fdump-unnumbered-links
1358 Common Report Var(flag_dump_unnumbered_links)
1359 Suppress output of previous and next insn numbers in debugging dumps.
1362 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1363 Enable CFI tables via GAS assembler directives.
1366 Common Report Var(flag_early_inlining) Init(1) Optimization
1367 Perform early inlining.
1369 feliminate-dwarf2-dups
1371 Does nothing. Preserved for backward compatibility.
1374 Common Report Var(flag_ipa_sra) Init(0) Optimization
1375 Perform interprocedural reduction of aggregates.
1377 feliminate-unused-debug-symbols
1378 Common Report Var(flag_debug_only_used_symbols)
1379 Perform unused symbol elimination in debug info.
1381 feliminate-unused-debug-types
1382 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1383 Perform unused type elimination in debug info.
1385 femit-class-debug-always
1386 Common Report Var(flag_emit_class_debug_always) Init(0)
1387 Do not suppress C++ class debug information.
1390 Common Report Var(flag_exceptions) Optimization
1391 Enable exception handling.
1393 fexpensive-optimizations
1394 Common Report Var(flag_expensive_optimizations) Optimization
1395 Perform a number of minor, expensive optimizations.
1398 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1399 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1402 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1405 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1408 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1410 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1411 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1412 fpermitted-flt-eval-methods=
1413 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1414 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1417 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)
1420 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1423 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1429 Common Var(flag_fat_lto_objects)
1430 Output lto objects containing both the intermediate language and binary output.
1433 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1434 Assume no NaNs or infinities are generated.
1437 Common Joined RejectNegative Var(common_deferred_options) Defer
1438 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1441 Common Report Var(flag_float_store) Optimization
1442 Don't allocate floats and doubles in extended-precision registers.
1446 Does nothing. Preserved for backward compatibility.
1449 Common Report Var(flag_forward_propagate) Optimization
1450 Perform a forward propagation pass on RTL.
1453 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1454 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1457 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1460 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1462 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1464 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1467 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1469 ffp-int-builtin-inexact
1470 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1471 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1473 ; Nonzero means don't put addresses of constant functions in registers.
1474 ; Used for compiling the Unix kernel, where strange substitutions are
1475 ; done on the assembly output.
1477 Common Report Var(flag_no_function_cse,0) Optimization
1478 Allow function addresses to be held in registers.
1481 Common Report Var(flag_function_sections)
1482 Place each function into its own section.
1485 Common Report Var(flag_gcse) Optimization
1486 Perform global common subexpression elimination.
1489 Common Report Var(flag_gcse_lm) Init(1) Optimization
1490 Perform enhanced load motion during global common subexpression elimination.
1493 Common Report Var(flag_gcse_sm) Init(0) Optimization
1494 Perform store motion after global common subexpression elimination.
1497 Common Report Var(flag_gcse_las) Init(0) Optimization
1498 Perform redundant load after store elimination in global common subexpression
1502 Common Report Var(flag_gcse_after_reload) Optimization
1503 Perform global common subexpression elimination after register allocation has
1507 Name(dwarf_gnat_encodings) Type(int)
1510 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1513 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1516 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1519 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1520 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1522 ; This option is not documented yet as its semantics will change.
1524 Common Report Var(flag_graphite) Optimization
1525 Enable in and out of Graphite representation.
1528 Common Report Var(flag_graphite_identity) Optimization
1529 Enable Graphite Identity transformation.
1531 fhoist-adjacent-loads
1532 Common Report Var(flag_hoist_adjacent_loads) Optimization
1533 Enable hoisting adjacent loads to encourage generating conditional move
1537 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1538 ; Always keep a pointer to a live memory block
1540 floop-parallelize-all
1541 Common Report Var(flag_loop_parallelize_all) Optimization
1542 Mark all loops as parallel.
1545 Common Alias(floop-nest-optimize)
1546 Enable loop nest transforms. Same as -floop-nest-optimize.
1549 Common Report Var(flag_loop_interchange) Optimization
1550 Enable loop interchange on trees.
1553 Common Alias(floop-nest-optimize)
1554 Enable loop nest transforms. Same as -floop-nest-optimize.
1556 floop-unroll-and-jam
1557 Common Report Var(flag_unroll_jam) Optimization
1558 Perform unroll-and-jam on loops.
1561 Common Report Var(flag_tm)
1562 Enable support for GNU transactional memory.
1565 Common Report Var(flag_gnu_unique) Init(1)
1566 Use STB_GNU_UNIQUE if supported by the assembler.
1570 Does nothing. Preserved for backward compatibility.
1573 Common Report Var(flag_loop_nest_optimize) Optimization
1574 Enable the loop nest optimizer.
1576 fstrict-volatile-bitfields
1577 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1578 Force bitfield accesses to match their type width.
1581 Common Report Var(flag_store_merging) Optimization
1582 Merge adjacent stores.
1584 fguess-branch-probability
1585 Common Report Var(flag_guess_branch_prob) Optimization
1586 Enable guessing of branch probabilities.
1588 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1589 ; Generate position-independent code for executables if possible
1590 ; On SVR4 targets, it also controls whether or not to emit a
1591 ; string identifying the compiler.
1593 Common Report Var(flag_no_ident,0)
1594 Process #ident directives.
1597 Common Report Var(flag_if_conversion) Optimization
1598 Perform conversion of conditional jumps to branchless equivalents.
1601 Common Report Var(flag_if_conversion2) Optimization
1602 Perform conversion of conditional jumps to conditional execution.
1605 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1606 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1609 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1612 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1615 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1618 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1620 ftree-loop-if-convert
1621 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1622 Convert conditional jumps in innermost loops to branchless equivalents.
1624 ftree-loop-if-convert-stores
1626 Does nothing. Preserved for backward compatibility.
1628 ; -finhibit-size-directive inhibits output of .size for ELF.
1629 ; This is used only for compiling crtstuff.c,
1630 ; and it may be extended to other effects
1631 ; needed for crtstuff.c on other systems.
1632 finhibit-size-directive
1633 Common Report Var(flag_inhibit_size_directive)
1634 Do not generate .size directives.
1637 Common Report Var(flag_indirect_inlining) Optimization
1638 Perform indirect inlining.
1640 ; General flag to enable inlining. Specifying -fno-inline will disable
1641 ; all inlining apart from always-inline functions.
1643 Common Report Var(flag_no_inline,0) Init(0) Optimization
1644 Enable inlining of function declared \"inline\", disabling disables all inlining.
1646 finline-small-functions
1647 Common Report Var(flag_inline_small_functions) Optimization
1648 Integrate functions into their callers when code size is known not to grow.
1651 Common Report Var(flag_inline_functions) Optimization
1652 Integrate functions not declared \"inline\" into their callers when profitable.
1654 finline-functions-called-once
1655 Common Report Var(flag_inline_functions_called_once) Optimization
1656 Integrate functions only required by their single caller.
1659 Common RejectNegative Joined Alias(finline-limit=)
1662 Common RejectNegative Joined UInteger
1663 -finline-limit=<number> Limit the size of inlined functions to <number>.
1666 Common Report Var(flag_inline_atomics) Init(1) Optimization
1667 Inline __atomic operations when a lock free instruction sequence is available.
1670 Common RejectNegative Alias(fcf-protection=,full)
1673 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1674 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1675 instructions have valid targets.
1678 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1681 Enum(cf_protection_level) String(full) Value(CF_FULL)
1684 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1687 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1690 Enum(cf_protection_level) String(none) Value(CF_NONE)
1692 finstrument-functions
1693 Common Report Var(flag_instrument_function_entry_exit)
1694 Instrument function entry and exit with profiling calls.
1696 finstrument-functions-exclude-function-list=
1697 Common RejectNegative Joined
1698 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1700 finstrument-functions-exclude-file-list=
1701 Common RejectNegative Joined
1702 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1705 Common Report Var(flag_ipa_cp) Optimization
1706 Perform interprocedural constant propagation.
1709 Common Report Var(flag_ipa_cp_clone) Optimization
1710 Perform cloning to make Interprocedural constant propagation stronger.
1714 Does nothing. Preserved for backward compatibility.
1717 Common Report Var(flag_ipa_bit_cp) Optimization
1718 Perform interprocedural bitwise constant propagation.
1721 Common Report Var(flag_ipa_profile) Init(0) Optimization
1722 Perform interprocedural profile propagation.
1725 Common Report Var(flag_ipa_pta) Init(0) Optimization
1726 Perform interprocedural points-to analysis.
1729 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1730 Discover pure and const functions.
1733 Common Report Var(flag_ipa_icf) Optimization
1734 Perform Identical Code Folding for functions and read-only variables.
1737 Common Report Var(flag_ipa_icf_functions) Optimization
1738 Perform Identical Code Folding for functions.
1741 Common Report Var(flag_ipa_icf_variables) Optimization
1742 Perform Identical Code Folding for variables.
1745 Common Report Var(flag_ipa_reference) Init(0) Optimization
1746 Discover read-only and non addressable static variables.
1748 fipa-reference-addressable
1749 Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization
1750 Discover read-only, write-only and non-addressable static variables.
1752 fipa-stack-alignment
1753 Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization
1754 Reduce stack alignment on call sites if possible.
1758 Does nothing. Preserved for backward compatibility.
1762 Does nothing. Preserved for backward compatibility.
1765 Common Report Var(flag_ipa_vrp) Optimization
1766 Perform IPA Value Range Propagation.
1769 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1770 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1773 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1776 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1779 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1782 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1783 -fira-region=[one|all|mixed] Set regions for IRA.
1786 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1789 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1792 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1795 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1798 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1799 Use IRA based register pressure calculation
1800 in RTL hoist optimizations.
1803 Common Report Var(flag_ira_loop_pressure) Optimization
1804 Use IRA based register pressure calculation
1805 in RTL loop optimizations.
1807 fira-share-save-slots
1808 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1809 Share slots for saving different hard registers.
1811 fira-share-spill-slots
1812 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1813 Share stack slots for spilled pseudo-registers.
1816 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1817 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1820 Common Report Var(flag_ivopts) Init(1) Optimization
1821 Optimize induction variables on trees.
1824 Common Var(flag_jump_tables) Init(1) Optimization
1825 Use jump tables for sufficiently large switch statements.
1827 fkeep-inline-functions
1828 Common Report Var(flag_keep_inline_functions)
1829 Generate code for functions even if they are fully inlined.
1831 fkeep-static-functions
1832 Common Report Var(flag_keep_static_functions)
1833 Generate code for static functions even if they are never called.
1836 Common Report Var(flag_keep_static_consts) Init(1)
1837 Emit static const variables even if they are not used.
1840 Common Report Var(flag_leading_underscore) Init(-1)
1841 Give external symbols a leading underscore.
1845 Does nothing. Preserved for backward compatibility.
1848 Common Report Var(flag_lra_remat) Optimization
1849 Do CFG-sensitive rematerialization in LRA.
1853 Enable link-time optimization.
1856 Common RejectNegative Joined Var(flag_lto)
1857 Link-time optimization with number of parallel jobs or jobserver.
1860 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1863 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1866 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1869 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1872 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1875 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1878 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1879 Specify the algorithm to partition symbols and vars at linktime.
1881 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1882 flto-compression-level=
1883 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1884 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1886 flto-odr-type-merging
1887 Common Report Var(flag_lto_odr_type_mering) Init(1)
1888 Merge C++ types using One Definition Rule.
1891 Common Report Var(flag_lto_report) Init(0)
1892 Report various link-time optimization statistics.
1895 Common Report Var(flag_lto_report_wpa) Init(0)
1896 Report various link-time optimization statistics for WPA only.
1899 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1900 Set errno after built-in math functions.
1903 Common Joined RejectNegative UInteger Var(flag_max_errors)
1904 -fmax-errors=<number> Maximum number of errors to report.
1907 Common Report Var(mem_report)
1908 Report on permanent memory allocation.
1911 Common Report Var(mem_report_wpa)
1912 Report on permanent memory allocation in WPA only.
1914 ; This will attempt to merge constant section constants, if 1 only
1915 ; string constants and constants from constant pool, if 2 also constant
1917 fmerge-all-constants
1918 Common Report Var(flag_merge_constants,2) Init(1)
1919 Attempt to merge identical constants and constant variables.
1922 Common Report Var(flag_merge_constants,1)
1923 Attempt to merge identical constants across compilation units.
1925 fmerge-debug-strings
1926 Common Report Var(flag_merge_debug_strings) Init(1)
1927 Attempt to merge identical debug strings across compilation units.
1930 Common RejectNegative Joined UInteger
1931 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1934 Common Report Var(flag_modulo_sched) Optimization
1935 Perform SMS based modulo scheduling before the first scheduling pass.
1937 fmodulo-sched-allow-regmoves
1938 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1939 Perform SMS based modulo scheduling with register moves allowed.
1941 fmove-loop-invariants
1942 Common Report Var(flag_move_loop_invariants) Optimization
1943 Move loop invariant computations out of loops.
1946 Common Var(flag_dce) Init(1) Optimization
1947 Use the RTL dead code elimination pass.
1950 Common Var(flag_dse) Init(1) Optimization
1951 Use the RTL dead store elimination pass.
1953 freschedule-modulo-scheduled-loops
1954 Common Report Var(flag_resched_modulo_sched) Optimization
1955 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1957 fnon-call-exceptions
1958 Common Report Var(flag_non_call_exceptions) Optimization
1959 Support synchronous non-call exceptions.
1962 Common Driver Joined MissingArgError(options or targets missing after %qs)
1963 -foffload=<targets>=<options> Specify offloading targets and options for them.
1966 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1967 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1970 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1973 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1976 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1979 Common Report Var(flag_omit_frame_pointer) Optimization
1980 When possible do not generate stack frames.
1983 Common Report Var(flag_opt_info) Optimization
1984 Enable all optimization info dumps on stderr.
1987 Common Joined RejectNegative Var(common_deferred_options) Defer
1988 -fopt-info[-<type>=filename] Dump compiler optimization details.
1990 fsave-optimization-record
1991 Common Report Var(flag_save_optimization_record) Optimization
1992 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
1994 foptimize-register-move
1996 Does nothing. Preserved for backward compatibility.
1998 foptimize-sibling-calls
1999 Common Report Var(flag_optimize_sibling_calls) Optimization
2000 Optimize sibling and tail recursive calls.
2003 Common Report Var(flag_partial_inlining) Optimization
2004 Perform partial inlining.
2007 Common Report Var(pre_ipa_mem_report)
2008 Report on memory allocation before interprocedural optimization.
2010 fpost-ipa-mem-report
2011 Common Report Var(post_ipa_mem_report)
2012 Report on memory allocation before interprocedural optimization.
2015 Common Report Var(flag_pack_struct) Optimization
2016 Pack structure members together without holes.
2019 Common RejectNegative Joined UInteger Optimization
2020 -fpack-struct=<number> Set initial maximum structure member alignment.
2023 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2024 Return small aggregates in memory, not registers.
2027 Common Report Var(flag_peel_loops) Optimization
2028 Perform loop peeling.
2031 Common Report Var(flag_no_peephole,0) Optimization
2032 Enable machine specific peephole optimizations.
2035 Common Report Var(flag_peephole2) Optimization
2036 Enable an RTL peephole pass before sched2.
2039 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
2040 Generate position-independent code if possible (large mode).
2043 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2044 Generate position-independent code for executables if possible (large mode).
2047 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2048 Generate position-independent code if possible (small mode).
2051 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2052 Generate position-independent code for executables if possible (small mode).
2055 Common Report Var(flag_plt) Init(1) Optimization
2056 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2059 Common Joined RejectNegative Var(common_deferred_options) Defer
2060 Specify a plugin to load.
2063 Common Joined RejectNegative Var(common_deferred_options) Defer
2064 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2066 fpredictive-commoning
2067 Common Report Var(flag_predictive_commoning) Optimization
2068 Run predictive commoning optimization.
2070 fprefetch-loop-arrays
2071 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2072 Generate prefetch instructions, if available, for arrays in loops.
2075 Common Report Var(profile_flag)
2076 Enable basic program profiling code.
2079 Common Report Var(profile_abs_path_flag)
2080 Generate absolute source path names for gcov.
2083 Common Report Var(profile_arc_flag)
2084 Insert arc-based program profiling code.
2087 Common Joined RejectNegative Var(profile_data_prefix)
2088 Set the top-level directory for storing the profile data.
2089 The default is 'pwd'.
2092 Common Report Var(flag_profile_correction)
2093 Enable correction of flow inconsistent profile data input.
2096 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2097 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2099 fprofile-filter-files=
2100 Common Joined RejectNegative Var(flag_profile_filter_files)
2101 Instrument only functions from files where names match any regular expression (separated by a semi-colon).
2103 fprofile-exclude-files=
2104 Common Joined RejectNegative Var(flag_profile_exclude_files)
2105 Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon).
2108 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2111 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2114 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2117 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2121 Enable common options for generating profile info for profile feedback directed optimizations.
2124 Common Joined RejectNegative
2125 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2128 Common Var(flag_profile_use)
2129 Enable common options for performing profile feedback directed optimizations.
2132 Common Joined RejectNegative
2133 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2136 Common Report Var(flag_profile_values)
2137 Insert code to profile values of expressions.
2140 Common Report Var(profile_report)
2141 Report on consistency of profile.
2143 fprofile-reorder-functions
2144 Common Report Var(flag_profile_reorder_functions)
2145 Enable function reordering that improves code placement.
2147 fpatchable-function-entry=
2148 Common Joined Optimization
2149 Insert NOP instructions at each function entry.
2152 Common Var(common_deferred_options) Defer
2155 Common Joined RejectNegative Var(common_deferred_options) Defer
2156 -frandom-seed=<string> Make compile reproducible using <string>.
2158 ; This switch causes the command line that was used to create an
2159 ; object file to be recorded into the object file. The exact format
2160 ; of this recording is target and binary file format dependent.
2161 ; It is related to the -fverbose-asm switch, but that switch only
2162 ; records information in the assembler output file as comments, so
2163 ; they never reach the object file.
2164 frecord-gcc-switches
2165 Common Report Var(flag_record_gcc_switches)
2166 Record gcc command line switches in the object file.
2169 Common Report Var(flag_pcc_struct_return,0) Optimization
2170 Return small aggregates in registers.
2174 Does nothing. Preserved for backward compatibility.
2177 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2178 Tell DSE that the storage for a C++ object is dead when the constructor
2179 starts and when the destructor finishes.
2182 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2184 flive-range-shrinkage
2185 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2186 Relief of register pressure through live range shrinkage.
2189 Common Report Var(flag_rename_registers) Init(2) Optimization
2190 Perform a register renaming optimization pass.
2193 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2194 Perform a target dependent instruction fusion optimization pass.
2197 Common Report Var(flag_reorder_blocks) Optimization
2198 Reorder basic blocks to improve code placement.
2200 freorder-blocks-algorithm=
2201 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2202 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2205 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2208 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2211 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2213 freorder-blocks-and-partition
2214 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2215 Reorder basic blocks and partition into hot and cold sections.
2218 Common Report Var(flag_reorder_functions) Optimization
2219 Reorder functions to improve code placement.
2221 frerun-cse-after-loop
2222 Common Report Var(flag_rerun_cse_after_loop) Optimization
2223 Add a common subexpression elimination pass after loop optimizations.
2227 Does nothing. Preserved for backward compatibility.
2230 Common Report Var(flag_rounding_math) Optimization SetByCombined
2231 Disable optimizations that assume default FP rounding behavior.
2234 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2235 Enable scheduling across basic blocks.
2238 Common Report Var(flag_sched_pressure) Init(0) Optimization
2239 Enable register pressure sensitive insn scheduling.
2242 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2243 Allow speculative motion of non-loads.
2246 Common Report Var(flag_schedule_speculative_load) Optimization
2247 Allow speculative motion of some loads.
2249 fsched-spec-load-dangerous
2250 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2251 Allow speculative motion of more loads.
2254 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2255 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2257 fsched2-use-superblocks
2258 Common Report Var(flag_sched2_use_superblocks) Optimization
2259 If scheduling post reload, do superblock scheduling.
2263 Does nothing. Preserved for backward compatibility.
2266 Common Report Var(flag_schedule_insns) Optimization
2267 Reschedule instructions before register allocation.
2270 Common Report Var(flag_schedule_insns_after_reload) Optimization
2271 Reschedule instructions after register allocation.
2273 ; This flag should be on when a target implements non-trivial
2274 ; scheduling hooks, maybe saving some information for its own sake.
2275 ; On IA64, for example, this is used for correct bundling.
2276 fselective-scheduling
2277 Common Report Var(flag_selective_scheduling) Optimization
2278 Schedule instructions using selective scheduling algorithm.
2280 fselective-scheduling2
2281 Common Report Var(flag_selective_scheduling2) Optimization
2282 Run selective scheduling after reload.
2285 Common Undocumented Joined Var(flag_self_test)
2286 Run self-tests, using the given path to locate test files.
2288 fsel-sched-pipelining
2289 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2290 Perform software pipelining of inner loops during selective scheduling.
2292 fsel-sched-pipelining-outer-loops
2293 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2294 Perform software pipelining of outer loops during selective scheduling.
2296 fsel-sched-reschedule-pipelined
2297 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2298 Reschedule pipelined regions without pipelining.
2300 fsemantic-interposition
2301 Common Report Var(flag_semantic_interposition) Init(1)
2302 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2304 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2305 ; of stalled insns into the ready list.
2306 fsched-stalled-insns
2307 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2308 Allow premature scheduling of queued insns.
2310 fsched-stalled-insns=
2311 Common RejectNegative Joined UInteger Optimization
2312 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2314 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2315 ; be examined for a dependency on a stalled insn that is candidate for
2316 ; premature removal from the queue of stalled insns into the ready list (has
2317 ; an effect only if the flag 'sched_stalled_insns' is set).
2318 fsched-stalled-insns-dep
2319 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2320 Set dependence distance checking in premature scheduling of queued insns.
2322 fsched-stalled-insns-dep=
2323 Common RejectNegative Joined UInteger Optimization
2324 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2326 fsched-group-heuristic
2327 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2328 Enable the group heuristic in the scheduler.
2330 fsched-critical-path-heuristic
2331 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2332 Enable the critical path heuristic in the scheduler.
2334 fsched-spec-insn-heuristic
2335 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2336 Enable the speculative instruction heuristic in the scheduler.
2338 fsched-rank-heuristic
2339 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2340 Enable the rank heuristic in the scheduler.
2342 fsched-last-insn-heuristic
2343 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2344 Enable the last instruction heuristic in the scheduler.
2346 fsched-dep-count-heuristic
2347 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2348 Enable the dependent count heuristic in the scheduler.
2351 Common Report Var(flag_section_anchors) Optimization
2352 Access data in the same section from shared anchor points.
2356 Does nothing. Preserved for backward compatibility.
2360 Does nothing. Preserved for backward compatibility.
2363 Common Report Var(flag_ree) Init(0)
2364 Turn on Redundant Extensions Elimination pass.
2367 Common Report Var(flag_show_column) Init(1)
2368 Show column numbers in diagnostics, when available. Default on.
2371 Common Report Var(flag_shrink_wrap) Optimization
2372 Emit function prologues only before parts of the function that need it,
2373 rather than at the top of the function.
2375 fshrink-wrap-separate
2376 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2377 Shrink-wrap parts of the prologue and epilogue separately.
2380 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2381 Disable optimizations observable by IEEE signaling NaNs.
2384 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2385 Disable floating point optimizations that ignore the IEEE signedness of zero.
2387 fsingle-precision-constant
2388 Common Report Var(flag_single_precision_constant) Optimization
2389 Convert floating point constants to single precision constants.
2391 fsplit-ivs-in-unroller
2392 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2393 Split lifetimes of induction variables when loops are unrolled.
2396 Common Report Var(flag_split_stack) Init(-1)
2397 Generate discontiguous stack frames.
2400 Common Report Var(flag_split_wide_types) Optimization
2401 Split wide types into independent registers.
2404 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2405 Enable backward propagation of use properties at the SSA level.
2408 Common Report Var(flag_ssa_phiopt) Optimization
2409 Optimize conditional patterns using SSA PHI nodes.
2412 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2413 Optimize amount of stdarg registers saved to stack at start of function.
2415 fvariable-expansion-in-unroller
2416 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2417 Apply variable expansion when loops are unrolled.
2420 Common Report RejectNegative Joined Optimization
2421 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2424 Common Alias(fstack-check=, specific, no)
2425 Insert stack checking code into the program. Same as -fstack-check=specific.
2427 fstack-clash-protection
2428 Common Report Var(flag_stack_clash_protection) Optimization
2429 Insert code to probe each page of stack space as it is allocated to protect
2430 from stack-clash style attacks.
2433 Common Var(common_deferred_options) Defer
2435 fstack-limit-register=
2436 Common RejectNegative Joined Var(common_deferred_options) Defer
2437 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2439 fstack-limit-symbol=
2440 Common RejectNegative Joined Var(common_deferred_options) Defer
2441 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2444 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2445 Use propolice as a stack protection method.
2447 fstack-protector-all
2448 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2449 Use a stack protection method for every function.
2451 fstack-protector-strong
2452 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2453 Use a smart stack protection method for certain functions.
2455 fstack-protector-explicit
2456 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2457 Use stack protection method only for functions with the stack_protect attribute.
2460 Common RejectNegative Var(flag_stack_usage)
2461 Output stack usage information on a per-function basis.
2465 Does nothing. Preserved for backward compatibility.
2467 ; Nonzero if we should do (language-dependent) alias analysis.
2468 ; Typically, this analysis will assume that expressions of certain
2469 ; types do not alias expressions of certain other types. Only used
2470 ; if alias analysis (in general) is enabled.
2472 Common Report Var(flag_strict_aliasing) Optimization
2473 Assume strict aliasing rules apply.
2477 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2480 Common Report Var(flag_sync_libcalls) Init(1)
2481 Implement __atomic operations via libcalls to legacy __sync functions.
2484 Common Report Var(flag_syntax_only)
2485 Check for syntax errors, then stop.
2488 Common Report Var(flag_test_coverage)
2489 Create data files needed by \"gcov\".
2492 Common Report Var(flag_thread_jumps) Optimization
2493 Perform jump threading optimizations.
2496 Common Report Var(time_report)
2497 Report the time taken by each compiler pass.
2499 ftime-report-details
2500 Common Report Var(time_report_details)
2501 Record times taken by sub-phases separately.
2504 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2505 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2508 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2511 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2514 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2517 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2520 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2523 Common Report Var(flag_toplevel_reorder) Init(2)
2524 Reorder top level functions, variables, and asms.
2527 Common Report Var(flag_tracer) Optimization
2528 Perform superblock formation via tail duplication.
2531 Common Report Var(flag_trampolines) Init(0)
2532 For targets that normally need trampolines for nested functions, always
2533 generate them instead of using descriptors.
2535 ; Zero means that floating-point math operations cannot generate a
2536 ; (user-visible) trap. This is the case, for example, in nonstop
2537 ; IEEE 754 arithmetic.
2539 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2540 Assume floating-point operations can trap.
2543 Common Report Var(flag_trapv) Optimization
2544 Trap for signed overflow in addition, subtraction and multiplication.
2547 Common Report Var(flag_tree_ccp) Optimization
2548 Enable SSA-CCP optimization on trees.
2551 Common Report Var(flag_tree_bit_ccp) Optimization
2552 Enable SSA-BIT-CCP optimization on trees.
2556 Does nothing. Preserved for backward compatibility.
2559 Common Report Var(flag_tree_ch) Optimization
2560 Enable loop header copying on trees.
2562 ftree-coalesce-inlined-vars
2563 Common Ignore RejectNegative
2564 Does nothing. Preserved for backward compatibility.
2567 Common Report Var(flag_tree_coalesce_vars) Optimization
2568 Enable SSA coalescing of user variables.
2572 Does nothing. Preserved for backward compatibility.
2575 Common Report Var(flag_tree_copy_prop) Optimization
2576 Enable copy propagation on trees.
2578 ftree-store-copy-prop
2580 Does nothing. Preserved for backward compatibility.
2583 Common Report Var(flag_tree_cselim) Init(2) Optimization
2584 Transform condition stores into unconditional ones.
2586 ftree-switch-conversion
2587 Common Report Var(flag_tree_switch_conversion) Optimization
2588 Perform conversions of switch initializations.
2591 Common Report Var(flag_tree_dce) Optimization
2592 Enable SSA dead code elimination optimization on trees.
2594 ftree-dominator-opts
2595 Common Report Var(flag_tree_dom) Optimization
2596 Enable dominator optimizations.
2599 Common Report Var(flag_tree_tail_merge) Optimization
2600 Enable tail merging on trees.
2603 Common Report Var(flag_tree_dse) Optimization
2604 Enable dead store elimination.
2607 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2608 Enable forward propagation on trees.
2611 Common Report Var(flag_tree_fre) Optimization
2612 Enable Full Redundancy Elimination (FRE) on trees.
2615 Common Report Var(flag_optimize_strlen) Optimization
2616 Enable string length optimizations on trees.
2618 fisolate-erroneous-paths-dereference
2619 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2620 Detect paths that trigger erroneous or undefined behavior due to
2621 dereferencing a null pointer. Isolate those paths from the main control
2622 flow and turn the statement with erroneous or undefined behavior into a trap.
2624 fisolate-erroneous-paths-attribute
2625 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2626 Detect paths that trigger erroneous or undefined behavior due to a null value
2627 being used in a way forbidden by a returns_nonnull or nonnull
2628 attribute. Isolate those paths from the main control flow and turn the
2629 statement with erroneous or undefined behavior into a trap.
2631 ftree-loop-distribution
2632 Common Report Var(flag_tree_loop_distribution) Optimization
2633 Enable loop distribution on trees.
2635 ftree-loop-distribute-patterns
2636 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2637 Enable loop distribution for patterns transformed into a library call.
2640 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2641 Enable loop invariant motion on trees.
2644 Common Alias(floop-nest-optimize)
2645 Enable loop nest transforms. Same as -floop-nest-optimize.
2648 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2649 Create canonical induction variables in loops.
2652 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2653 Enable loop optimizations on tree level.
2655 ftree-parallelize-loops=
2656 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2657 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2660 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2661 Enable hoisting loads from conditional pointers.
2664 Common Report Var(flag_tree_pre) Optimization
2665 Enable SSA-PRE optimization on trees.
2668 Common Report Var(flag_tree_partial_pre) Optimization
2669 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2672 Common Report Var(flag_tree_pta) Optimization
2673 Perform function-local points-to analysis on trees.
2676 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2677 Enable reassociation on tree level.
2681 Does nothing. Preserved for backward compatibility.
2684 Common Report Var(flag_tree_sink) Optimization
2685 Enable SSA code sinking on trees.
2688 Common Report Var(flag_tree_slsr) Optimization
2689 Perform straight-line strength reduction.
2692 Common Report Var(flag_tree_sra) Optimization
2693 Perform scalar replacement of aggregates.
2696 Common Report Var(flag_tree_ter) Optimization
2697 Replace temporary expressions in the SSA->normal pass.
2700 Common Report Var(flag_tree_live_range_split) Optimization
2701 Perform live range splitting during the SSA->normal pass.
2704 Common Report Var(flag_tree_vrp) Init(0) Optimization
2705 Perform Value Range Propagation on trees.
2708 Common Report Var(flag_split_paths) Init(0) Optimization
2709 Split paths leading to loop backedges.
2711 funconstrained-commons
2712 Common Var(flag_unconstrained_commons) Optimization
2713 Assume common declarations may be overridden with ones with a larger
2717 Common Report Var(flag_unit_at_a_time) Init(1)
2718 Compile whole compilation unit at a time.
2721 Common Report Var(flag_unroll_loops) Optimization
2722 Perform loop unrolling when iteration count is known.
2725 Common Report Var(flag_unroll_all_loops) Optimization
2726 Perform loop unrolling for all loops.
2728 ; Nonzero means that loop optimizer may assume that the induction variables
2729 ; that control loops do not overflow and that the loops with nontrivial
2730 ; exit condition are not infinite
2731 funsafe-loop-optimizations
2733 Does nothing. Preserved for backward compatibility.
2736 Common Report Var(flag_associative_math) SetByCombined Optimization
2737 Allow optimization for floating-point arithmetic which may change the
2738 result of the operation due to rounding.
2741 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2742 Same as -fassociative-math for expressions which include division.
2744 ; Nonzero means that unsafe floating-point math optimizations are allowed
2745 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2746 ; are allowed to assume that their arguments and results are "normal"
2747 ; (e.g., nonnegative for SQRT).
2748 funsafe-math-optimizations
2749 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2750 Allow math optimizations that may violate IEEE or ISO standards.
2753 Common Report Var(flag_unswitch_loops) Optimization
2754 Perform loop unswitching.
2757 Common Report Var(flag_split_loops) Optimization
2758 Perform loop splitting.
2761 Common Report Var(flag_unwind_tables) Optimization
2762 Just generate unwind tables for exception handling.
2765 Common Driver Negative(fuse-ld=gold)
2766 Use the bfd linker instead of the default linker.
2769 Common Driver Negative(fuse-ld=bfd)
2770 Use the gold linker instead of the default linker.
2773 Common Driver Negative(fuse-ld=lld)
2774 Use the lld LLVM linker instead of the default linker.
2777 Common Undocumented Var(flag_use_linker_plugin)
2779 ; Positive if we should track variables, negative if we should run
2780 ; the var-tracking pass only to discard debug annotations, zero if
2781 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2782 ; will be set according to optimize, debug_info_level and debug_hooks
2783 ; in process_options ().
2785 Common Report Var(flag_var_tracking) Init(2) PerFunction
2786 Perform variable tracking.
2788 ; Positive if we should track variables at assignments, negative if
2789 ; we should run the var-tracking pass only to discard debug
2790 ; annotations. When flag_var_tracking_assignments ==
2791 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2792 fvar-tracking-assignments
2793 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2794 Perform variable tracking by annotating assignments.
2796 ; Nonzero if we should toggle flag_var_tracking_assignments after
2797 ; processing options and computing its default. */
2798 fvar-tracking-assignments-toggle
2799 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2800 Toggle -fvar-tracking-assignments.
2802 ; Positive if we should track uninitialized variables, negative if
2803 ; we should run the var-tracking pass only to discard debug
2804 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2805 ; will be set according to flag_var_tracking.
2806 fvar-tracking-uninit
2807 Common Report Var(flag_var_tracking_uninit) PerFunction
2808 Perform variable tracking and also tag variables that are uninitialized.
2810 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2812 Common Report Optimization
2813 Enable vectorization on trees.
2815 ftree-vectorizer-verbose=
2816 Common Joined RejectNegative Ignore
2817 Does nothing. Preserved for backward compatibility.
2819 ftree-loop-vectorize
2820 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2821 Enable loop vectorization on trees.
2824 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2825 Enable basic block vectorization (SLP) on trees.
2828 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2829 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2832 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2833 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2836 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2839 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2842 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2845 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2848 Common Alias(fvect-cost-model=,dynamic,unlimited)
2849 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2851 ftree-vect-loop-version
2853 Does nothing. Preserved for backward compatibility.
2856 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2857 Enable copy propagation of scalar-evolution information.
2859 ; -fverbose-asm causes extra commentary information to be produced in
2860 ; the generated assembly code (to make it more readable). This option
2861 ; is generally only of use to those who actually need to read the
2862 ; generated assembly code (perhaps while debugging the compiler itself).
2863 ; -fno-verbose-asm, the default, causes the extra information
2864 ; to not be added and is useful when comparing two assembler files.
2866 Common Report Var(flag_verbose_asm)
2867 Add extra commentary to assembler output.
2870 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2871 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2874 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2877 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2880 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2883 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2886 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2889 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2890 Validate vtable pointers before using them.
2893 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2896 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2899 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2902 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2905 Common Var(flag_vtv_counts)
2906 Output vtable verification counters.
2909 Common Var(flag_vtv_debug)
2910 Output vtable verification pointer sets information.
2913 Common Report Var(flag_value_profile_transformations) Optimization
2914 Use expression value profiles in optimizations.
2917 Common Report Var(flag_web) Init(2) Optimization
2918 Construct webs and split unrelated uses of single variable.
2920 ftree-builtin-call-dce
2921 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2922 Enable conditional dead code elimination for builtin calls.
2925 Common Report Var(flag_whole_program) Init(0)
2926 Perform whole program optimizations.
2929 Common Report Var(flag_wrapv_pointer) Optimization
2930 Assume pointer overflow wraps around.
2933 Common Report Var(flag_wrapv) Optimization
2934 Assume signed arithmetic overflow wraps around.
2936 fzero-initialized-in-bss
2937 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2938 Put zero initialized data in the bss section.
2941 Common Driver RejectNegative JoinedOrMissing
2942 Generate debug information in default format.
2945 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2946 Assume assembler support for (DWARF2+) .loc directives
2949 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2950 Assume assembler support for view in (DWARF2+) .loc directives
2953 Common Driver Deprecated
2954 Does nothing. Preserved for backward compatibility.
2957 Common Driver Deprecated
2958 Does nothing. Preserved for backward compatibility.
2961 Common Driver Deprecated
2962 Does nothing. Preserved for backward compatibility.
2965 Common Driver Deprecated
2966 Does nothing. Preserved for backward compatibility.
2969 Common Driver Var(debug_column_info,1) Init(1)
2970 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2973 Common Driver JoinedOrMissing Negative(gdwarf-)
2974 Generate debug information in default version of DWARF format.
2977 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2978 Generate debug information in DWARF v2 (or later) format.
2981 Common Driver JoinedOrMissing
2982 Generate debug information in default extended format.
2985 Common Driver Var(debug_inline_points) Init(2)
2986 Generate extended entry point information for inlined functions
2988 ginternal-reset-location-views
2989 Common Driver Var(debug_internal_reset_location_views) Init(2)
2990 Compute locview reset points based on insn length estimates
2993 RejectNegative Joined Undocumented
2994 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
2997 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2998 Don't generate DWARF pubnames and pubtypes sections.
3001 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3002 Generate DWARF pubnames and pubtypes sections.
3005 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3006 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3008 grecord-gcc-switches
3009 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3010 Record gcc command line switches in DWARF DW_AT_producer.
3013 Common Driver Var(dwarf_split_debug_info) Init(0)
3014 Generate debug information in separate .dwo files.
3017 Common Driver JoinedOrMissing Negative(gstabs+)
3018 Generate debug information in STABS format.
3021 Common Driver JoinedOrMissing Negative(gvms)
3022 Generate debug information in extended STABS format.
3024 gstatement-frontiers
3025 Common Driver Var(debug_nonbind_markers_p) Init(2)
3026 Emit progressive recommended breakpoint locations.
3029 Common Driver Report Var(dwarf_strict) Init(0)
3030 Don't emit DWARF additions beyond selected version.
3033 Common Driver Report Var(flag_describe_dies) Init(0)
3034 Add description attributes to some DWARF DIEs that have no name attribute.
3037 Common Driver Report Var(flag_gtoggle)
3038 Toggle debug information generation.
3040 gvariable-location-views
3041 Common Driver Var(debug_variable_location_views, 1) Init(2)
3042 Augment variable location lists with progressive views.
3044 gvariable-location-views=incompat5
3045 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3048 Common Driver JoinedOrMissing Negative(gxcoff)
3049 Generate debug information in VMS format.
3052 Common Driver JoinedOrMissing Negative(gxcoff+)
3053 Generate debug information in XCOFF format.
3056 Common Driver JoinedOrMissing Negative(gdwarf)
3057 Generate debug information in extended XCOFF format.
3060 Name(compressed_debug_sections) Type(int)
3062 ; Since -gz= is completely handled in specs, the values aren't used and we
3063 ; assign arbitrary constants.
3065 Enum(compressed_debug_sections) String(none) Value(0)
3068 Enum(compressed_debug_sections) String(zlib) Value(1)
3071 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3075 Generate compressed debug sections.
3078 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3079 -gz=<format> Generate compressed debug sections in format <format>.
3082 Driver Joined Separate
3085 Common Joined Var(plugindir_string) Init(0)
3086 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3089 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3090 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3093 Driver Joined Separate
3098 no-canonical-prefixes
3114 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3115 -o <file> Place output into <file>.
3118 Common Var(profile_flag)
3119 Enable function profiling.
3122 Driver Var(pass_exit_codes)
3125 Common Alias(Wpedantic)
3128 Common Var(flag_pedantic_errors)
3129 Like -pedantic but issue them as errors.
3135 Driver Var(use_pipes)
3138 Driver JoinedOrMissing Var(print_file_name)
3140 print-libgcc-file-name
3143 print-multi-directory
3144 Driver Var(print_multi_directory)
3147 Driver Var(print_multi_lib)
3149 print-multi-os-directory
3150 Driver Var(print_multi_os_directory)
3153 Driver Var(print_multiarch)
3156 Driver JoinedOrMissing Var(print_prog_name)
3159 Driver Var(print_search_dirs)
3162 Driver Var(print_sysroot)
3164 print-sysroot-headers-suffix
3165 Driver Var(print_sysroot_headers_suffix)
3168 Common Var(quiet_flag) RejectDriver
3169 Do not display functions compiled or elapsed time.
3187 Driver Var(report_times)
3190 Driver JoinedOrMissing
3193 Driver Joined Separate
3197 ; C option, but driver must not handle as "-u ndef".
3200 Common Driver Var(verbose_flag)
3201 Enable verbose output.
3204 Common Var(version_flag) RejectDriver
3205 Display the compiler's version.
3208 Common Var(inhibit_warnings)
3212 Driver Separate Var(wrapper_string)
3215 Driver Joined Separate
3218 Driver RejectNegative Negative(static-pie)
3219 Create a shared library.
3225 Driver Separate Alias(specs=)
3238 ; Documented for Fortran, but always accepted by driver.
3245 ; Documented for Go, but always accepted by driver.
3263 Driver RejectNegative Negative(shared)
3264 Don't create a dynamically linked position independent executable.
3267 Driver RejectNegative Negative(no-pie)
3268 Create a dynamically linked position independent executable.
3271 Driver RejectNegative Negative(pie)
3272 Create a static position independent executable.
3275 Driver Joined Separate
3278 Common Report Var(flag_ipa_ra) Optimization
3279 Use caller save register across calls if possible.
3281 ; This comment is to ensure we retain the blank line above.