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).
53 int flag_incremental_link = 0
55 ; 0 means straightforward implementation of complex divide acceptable.
56 ; 1 means wide ranges of inputs must work for complex divide.
57 ; 2 means C99-like requirements for complex multiply and divide.
59 int flag_complex_method = 1
61 ; Language specific warning pass for unused results.
63 bool flag_warn_unused_result = false
68 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
72 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
74 int flag_generate_offload = 0
76 ; True to warn about any objects definitions whose size is larger
77 ; than N bytes. Also want about function definitions whose returned
78 ; values are larger than N bytes, where N is 'larger_than_size'.
83 HOST_WIDE_INT larger_than_size
85 ; True to warn about any function whose frame size is larger
88 bool warn_frame_larger_than
91 HOST_WIDE_INT frame_larger_than_size
93 ; Nonzero means we should be saving declaration info into a .X file.
95 int flag_gen_aux_info = 0
97 ; Nonzero if we are compiling code for a shared library, zero for
102 ; These two are really VEC(char_p,heap) *.
105 void *flag_instrument_functions_exclude_functions
108 void *flag_instrument_functions_exclude_files
110 ; Generic structs (e.g. templates not explicitly specialized)
111 ; may not have a compilation unit associated with them, and so
112 ; may need to be treated differently from ordinary structs.
114 ; Structs only handled by reference (indirectly), will also usually
115 ; not need as much debugging information.
118 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
121 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
123 ; True if we should exit after parsing options.
125 bool exit_after_options
127 ; Type(s) of debugging information we are producing (if any). See
128 ; flag-types.h for the definitions of the different possible types of
129 ; debugging information.
131 enum debug_info_type write_symbols = NO_DEBUG
133 ; Level of debugging information we are producing. See flag-types.h
134 ; for the definitions of the different possible levels.
136 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
138 ; Nonzero means use GNU-only extensions in the generated symbolic
139 ; debugging information. Currently, this only has an effect when
140 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
142 bool use_gnu_debug_info_extensions
144 ; Original value of maximum field alignment in bytes, specified via
145 ; -fpack-struct=<value>.
147 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
149 ; Type of stack check.
151 enum stack_check_type flag_stack_check = NO_STACK_CHECK
153 ; True if stack usage information needs to be computed.
155 bool flag_stack_usage_info = false
157 ; -dA causes debug commentary information to be produced in
158 ; the generated assembly code (to make it more readable). This option
159 ; is generally only of use to those who actually need to read the
160 ; generated assembly code (perhaps while debugging the compiler itself).
161 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
162 ; to be a catchall for printing debug information in the assembler file.
166 ; How many NOP insns to place at each function entry by default
168 HOST_WIDE_INT function_entry_patch_area_size
170 ; And how far the real asm entry point is into this area
172 HOST_WIDE_INT function_entry_patch_area_start
174 ; Balance between GNAT encodings and standard DWARF to emit.
176 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
178 ; -dP causes the rtl to be emitted as a comment in assembly.
180 int flag_dump_rtl_in_asm
182 ; Whether -da was passed (used only in handle_common_deferred_options).
184 bool flag_dump_all_passed
186 ; Other flags saying which kinds of debugging dump have been requested.
189 int rtl_dump_and_exit
192 int flag_print_asm_name
194 ; Name of top-level original source file (what was input to cpp).
195 ; This comes from the #-command at the beginning of the actual input.
196 ; If there isn't any there, then this is the cc1 input file name.
198 const char *main_input_filename
200 ; Pointer to base name in main_input_filename, with directories and a
201 ; single final extension removed, and the length of this base
205 const char *main_input_basename
208 int main_input_baselength
210 ; Which options have been printed by --help.
214 ; Which enums have been printed by --help. 0 = not printed, no
215 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
218 char *help_enum_printed
220 ; The number of columns for --help output.
222 unsigned int help_columns
224 ; Whether this options structure has been through finish_options
226 bool flag_opts_finished
228 ; What the sanitizer should instrument
230 unsigned int flag_sanitize
232 ; What sanitizers should recover from errors
234 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
236 ; What the coverage sanitizers should instrument
238 unsigned int flag_sanitize_coverage
240 ; Flag whether a prefix has been added to dump_base_name
242 bool dump_base_name_prefixed = false
244 ; Flag whether HSA generation has been explicitely disabled
246 bool flag_disable_hsa = false
258 Driver Alias(coverage)
264 Common Separate Alias(d)
267 Common Joined Alias(d)
270 Common Separate Alias(dumpbase)
273 Common Separate Alias(dumpdir)
276 Driver Separate Alias(e)
279 Driver Joined Alias(e)
282 Common Warning Alias(Wextra)
285 Driver Separate Alias(Xassembler)
288 Driver JoinedOrMissing Alias(Xassembler)
291 Driver Separate Alias(Xlinker)
294 Driver JoinedOrMissing Alias(Xlinker)
297 Driver Separate Alias(u)
300 Driver Joined Alias(u)
303 Common Driver Var(help_flag)
304 Display this information.
307 Common Driver Report Joined
308 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
311 Driver Separate Alias(x)
314 Driver Joined Alias(x)
317 Driver Separate Alias(L)
320 Driver Joined Alias(L)
322 -no-canonical-prefixes
323 Driver Alias(no-canonical-prefixes)
325 -no-standard-libraries
326 Driver Alias(nostdlib)
329 Driver Var(no_sysroot_suffix)
338 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
341 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
344 Driver Alias(pass-exit-codes)
347 Common Alias(Wpedantic)
350 Common Alias(pedantic-errors)
356 Driver Alias(static-pie)
362 Driver Separate Alias(B)
365 Driver JoinedOrMissing Alias(B)
371 Driver Separate Alias(print-file-name=)
374 Driver JoinedOrMissing Alias(print-file-name=)
376 -print-libgcc-file-name
377 Driver Alias(print-libgcc-file-name)
379 -print-multi-directory
380 Driver Alias(print-multi-directory)
383 Driver Alias(print-multi-lib)
385 -print-multi-os-directory
386 Driver Alias(print-multi-os-directory)
389 Driver Alias(print-multiarch)
392 Driver Separate Alias(print-prog-name=)
395 Driver JoinedOrMissing Alias(print-prog-name=)
398 Driver Alias(print-search-dirs)
401 Driver Alias(print-sysroot)
403 -print-sysroot-headers-suffix
404 Driver Alias(print-sysroot-headers-suffix)
410 Driver Alias(save-temps)
416 Driver Separate Alias(specs=)
419 Driver Joined Alias(specs=)
425 Driver Alias(symbolic)
429 Alias for --help=target.
437 ;; The driver used to convert options such as --help into forms such
438 ;; as -fhelp; the following four entries are for compatibility with
439 ;; any direct uses of those (undocumented) -f forms
441 Common Driver Alias(-help)
444 Common Driver Joined Alias(-help=)
447 Common Driver Alias(-target-help)
450 Common Driver Alias(-version)
454 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
457 Common Joined Alias(-param)
460 Driver Separate Alias(-sysroot=)
463 Driver JoinedOrMissing
469 Driver Joined Separate
475 Driver Joined Separate
481 Common JoinedOrMissing Optimization
482 -O<number> Set optimization level to <number>.
486 Optimize for space rather than speed.
490 Optimize for speed disregarding exact standards compliance.
494 Optimize for debugging experience rather than speed or size.
506 Driver Joined Separate
512 Driver Joined Separate
533 Common RejectNegative Warning Alias(Wextra)
534 This switch is deprecated; use -Wextra instead.
537 Driver JoinedOrMissing RejectNegative
540 Driver JoinedOrMissing RejectNegative
543 Driver JoinedOrMissing RejectNegative
546 Common Var(warn_aggregate_return) Warning
547 Warn about returning structures, unions or arrays.
549 Waggressive-loop-optimizations
550 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
551 Warn if a loop with constant number of iterations triggers undefined behavior.
554 Common Var(warn_array_bounds) Warning
555 Warn if an array is accessed out of bounds.
558 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
559 Warn if an array is accessed out of bounds.
562 Common Var(warn_attributes) Init(1) Warning
563 Warn about inappropriate attribute usage.
566 Common Var(warn_attributes) Init(1) Warning
567 Warn about type safety and similar errors in attribute alias and related.
570 Common Var(warn_cast_align) Warning
571 Warn about pointer casts which increase alignment.
574 Common Var(warn_cast_align,2) Warning
575 Warn about pointer casts which increase alignment.
578 Common Var(warn_cpp) Init(1) Warning
579 Warn when a #warning directive is encountered.
581 Wdeprecated-declarations
582 Common Var(warn_deprecated_decl) Init(1) Warning
583 Warn about uses of __attribute__((deprecated)) declarations.
585 Wdisabled-optimization
586 Common Var(warn_disabled_optimization) Warning
587 Warn when an optimization pass is disabled.
590 Common Var(warnings_are_errors)
591 Treat all warnings as errors.
595 Treat specified warning as error.
598 Common Var(extra_warnings) Warning
599 Print extra (possibly unwanted) warnings.
602 Common Var(flag_fatal_errors)
603 Exit on the first error occurred.
606 Common RejectNegative Joined UInteger Warning
607 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes.
610 Common Var(warn_free_nonheap_object) Init(1) Warning
611 Warn when attempting to free a non-heap object.
614 Common Var(warn_hsa) Init(1) Warning
615 Warn when a function cannot be expanded to HSAIL.
617 Wimplicit-fallthrough
618 Common Alias(Wimplicit-fallthrough=,3,0) Warning
620 Wimplicit-fallthrough=
621 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
622 Warn when a switch case falls through.
625 Common Var(warn_inline) Warning
626 Warn when an inlined function cannot be inlined.
628 Winvalid-memory-model
629 Common Var(warn_invalid_memory_model) Init(1) Warning
630 Warn when an atomic memory model parameter is known to be outside the valid range.
633 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
636 Common RejectNegative Joined UInteger Warning
637 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
640 Var(warn_nonnull_compare) Warning
641 Warn if comparing pointer parameter with nonnull attribute with NULL.
644 Common Var(warn_null_dereference) Warning
645 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
647 Wunsafe-loop-optimizations
648 Common Ignore Warning
649 Does nothing. Preserved for backward compatibility.
652 Common Warning Alias(Wsuggest-attribute=noreturn)
655 Common Var(warn_odr_violations) Init(1) Warning
656 Warn about some C++ One Definition Rule violations during link time optimization.
659 Common Var(warn_overflow) Init(1) Warning
660 Warn about overflow in arithmetic expressions.
663 Common Var(warn_lto_type_mismatch) Init(1) Warning
664 During link time optimization warn about mismatched types of global declarations.
667 Common Var(warn_packed) Warning
668 Warn when the packed attribute has no effect on struct layout.
671 Common Var(warn_padded) Warning
672 Warn when padding is required to align structure members.
675 Common Var(pedantic) Init(0) Warning
676 Issue warnings needed for strict compliance to the standard.
679 Common Var(warn_return_local_addr) Init(1) Warning
680 Warn about returning a pointer/reference to a local or temporary variable.
683 Common Var(warn_shadow) Warning
684 Warn when one variable shadows another. Same as -Wshadow=global.
687 Common Warning Alias(Wshadow)
688 Warn when one variable shadows another (globally).
691 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
692 Warn when one local variable shadows another local variable or parameter.
695 Common Warning Undocumented Alias(Wshadow=local)
697 Wshadow=compatible-local
698 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
699 Warn when one local variable shadows another local variable or parameter of compatible type.
701 Wshadow-compatible-local
702 Common Warning Undocumented Alias(Wshadow=compatible-local)
705 Common Var(warn_stack_protect) Warning
706 Warn when not issuing stack smashing protection for some reason.
709 Common Joined RejectNegative UInteger Var(warn_stack_usage) Warning
710 -Wstack-usage=<number> Warn if stack usage might be larger than specified amount.
714 Warn about code which might break strict aliasing rules.
717 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
718 Warn about code which might break strict aliasing rules.
722 Warn about optimizations that assume that signed overflow is undefined.
725 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
726 Warn about optimizations that assume that signed overflow is undefined.
728 Wsuggest-attribute=cold
729 Common Var(warn_suggest_attribute_cold) Warning
730 Warn about functions which might be candidates for __attribute__((cold)).
732 Wsuggest-attribute=const
733 Common Var(warn_suggest_attribute_const) Warning
734 Warn about functions which might be candidates for __attribute__((const)).
736 Wsuggest-attribute=pure
737 Common Var(warn_suggest_attribute_pure) Warning
738 Warn about functions which might be candidates for __attribute__((pure)).
740 Wsuggest-attribute=noreturn
741 Common Var(warn_suggest_attribute_noreturn) Warning
742 Warn about functions which might be candidates for __attribute__((noreturn)).
744 Wsuggest-attribute=malloc
745 Common Var(warn_suggest_attribute_malloc) Warning
746 Warn about functions which might be candidates for __attribute__((malloc)).
749 Common Var(warn_suggest_final_types) Warning
750 Warn about C++ polymorphic types where adding final keyword would improve code quality.
752 Wsuggest-final-methods
753 Common Var(warn_suggest_final_methods) Warning
754 Warn about C++ virtual methods where adding final keyword would improve code quality.
757 Common Var(warn_switch_unreachable) Warning Init(1)
758 Warn about statements between switch's controlling expression and the first
762 Common Var(warn_system_headers) Warning
763 Do not suppress warnings from system headers.
766 Common Var(warn_trampolines) Warning
767 Warn whenever a trampoline is generated.
770 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
771 Warn if a comparison is always true or always false due to the limited range of the data type.
774 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
775 Warn about uninitialized automatic variables.
778 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
779 Warn about maybe uninitialized automatic variables.
782 Common Ignore Warning
783 Does nothing. Preserved for backward compatibility.
786 Common Var(warn_unused) Init(0) Warning
787 Enable all -Wunused- warnings.
789 Wunused-but-set-parameter
790 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
791 Warn when a function parameter is only set, otherwise unused.
793 Wunused-but-set-variable
794 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
795 Warn when a variable is only set, otherwise unused.
798 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
799 Warn when a function is unused.
802 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
803 Warn when a label is unused.
806 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
807 Warn when a function parameter is unused.
810 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
811 Warn when an expression value is unused.
814 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
815 Warn when a variable is unused.
818 Common Var(warn_coverage_mismatch) Init(1) Warning
819 Warn in case profiles in -fprofile-use do not match.
821 Wvector-operation-performance
822 Common Var(warn_vector_operation_performance) Warning
823 Warn when a vector operation is compiled outside the SIMD.
838 Common Separate Var(aux_info_file_name)
839 -aux-info <file> Emit declaration information into <file>.
842 Common Joined Alias(aux-info)
845 Common Separate RejectDriver Var(aux_base_name)
848 Common Separate RejectDriver
858 -d<letters> Enable dumps from specific passes of the compiler.
861 Common Separate Var(dump_base_name)
862 -dumpbase <file> Set the file basename to be used for dumps.
865 Common Separate Var(dump_dir_name)
866 -dumpdir <dir> Set the directory name to be used for dumps.
881 Driver Joined Separate
883 ; This option has historically been passed down to the linker by an
884 ; accident of a %{e*} spec, so ensure it continues to be passed down
885 ; as a single option. The supported option for this purpose is
886 ; -rdynamic. See PR 47390.
890 ; The version of the C++ ABI in use. The following values are allowed:
892 ; 0: The version of the ABI believed most conformant with the C++ ABI
893 ; specification. This ABI may change as bugs are discovered and fixed.
894 ; Therefore, 0 will not necessarily indicate the same ABI in different
897 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
899 ; 2: The version of the ABI first used in G++ 3.4, and the default
902 ; 3: The version of the ABI that fixes the missing underscore
903 ; in template non-type arguments of pointer type.
905 ; 4: The version of the ABI that introduces unambiguous mangling of
906 ; vector types. First selectable in G++ 4.5.
908 ; 5: The version of the ABI that ignores attribute const/noreturn
909 ; in function pointer mangling, and corrects mangling of decltype and
910 ; function parameters used in other parameters and the return type.
911 ; First selectable in G++ 4.6.
913 ; 6: The version of the ABI that doesn't promote scoped enums to int and
914 ; changes the mangling of template argument packs, const/static_cast,
915 ; prefix ++ and --, and a class scope function used as a template
917 ; First selectable in G++ 4.7.
919 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
920 ; corrects the mangling of lambdas in default argument scope.
921 ; First selectable in G++ 4.8.
923 ; 8: The version of the ABI that corrects the substitution behavior of
924 ; function types with function-cv-qualifiers.
925 ; First selectable in G++ 4.9 and default in G++ 5.
927 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
928 ; First selectable and default in G++ 5.2.
930 ; 10: The version of the ABI that mangles attributes that affect type
931 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
932 ; Default in G++ 6 (set in c_common_post_options).
934 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
935 ; and introduces new inheriting constructor handling.
938 ; 12: Corrects the calling convention for classes with only deleted copy/move
939 ; constructors and changes passing/returning of empty records.
940 ; Default in G++ 8.1.
942 ; 13: Fixes the accidental change in 12 to the calling convention for classes
943 ; with deleted copy constructor and trivial move constructor.
944 ; Default in G++ 8.2.
946 ; Additional positive integers will be assigned as new versions of
947 ; the ABI become the default version of the ABI.
949 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
950 The version of the C++ ABI in use.
952 faggressive-loop-optimizations
953 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
954 Aggressively optimize loops using language constraints.
957 Common Report Var(align_functions,0) Optimization UInteger
958 Align the start of functions.
961 Common RejectNegative Joined UInteger Var(align_functions) Optimization
963 flimit-function-alignment
964 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
967 Common Report Var(align_jumps,0) Optimization UInteger
968 Align labels which are only reached by jumping.
971 Common RejectNegative Joined UInteger Var(align_jumps) Optimization
974 Common Report Var(align_labels,0) Optimization UInteger
978 Common RejectNegative Joined UInteger Var(align_labels) Optimization
981 Common Report Var(align_loops,0) Optimization UInteger
982 Align the start of loops.
985 Common RejectNegative Joined UInteger Var(align_loops) Optimization
989 Does nothing. Preserved for backward compatibility.
993 Does nothing. Preserved for backward compatibility.
995 fargument-noalias-global
997 Does nothing. Preserved for backward compatibility.
999 fargument-noalias-anything
1001 Does nothing. Preserved for backward compatibility.
1004 Common Driver Report Joined
1005 Select what to sanitize.
1008 Common Report Joined
1009 Select type of coverage sanitization.
1011 fasan-shadow-offset=
1012 Common Joined RejectNegative Var(common_deferred_options) Defer
1013 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1016 Common Joined RejectNegative Var(common_deferred_options) Defer
1017 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1018 in user-defined sections.
1021 Common Report Joined
1022 After diagnosing undefined behavior attempt to continue execution.
1026 This switch is deprecated; use -fsanitize-recover= instead.
1028 fsanitize-address-use-after-scope
1029 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1031 fsanitize-undefined-trap-on-error
1032 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1033 Use trap instead of a library function for undefined behavior sanitization.
1035 fasynchronous-unwind-tables
1036 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1037 Generate unwind tables that are exact at each instruction boundary.
1040 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1041 Generate auto-inc/dec instructions.
1044 Common Report Var(flag_auto_profile)
1045 Use sample profile information for call graph node weights. The default
1046 profile file is fbdata.afdo in 'pwd'.
1049 Common Joined RejectNegative Var(auto_profile_file)
1050 Use sample profile information for call graph node weights. The profile
1051 file is specified in the argument.
1053 ; -fcheck-bounds causes gcc to generate array bounds checks.
1054 ; For C, C++ and ObjC: defaults off.
1055 ; For Java: defaults to on.
1056 ; For Fortran: defaults to off.
1058 Common Report Var(flag_bounds_check)
1059 Generate code to check bounds before indexing arrays.
1062 Common Report Var(flag_branch_on_count_reg) Optimization
1063 Replace add, compare, branch with branch on count register.
1065 fbranch-probabilities
1066 Common Report Var(flag_branch_probabilities) Optimization
1067 Use profiling information for branch probabilities.
1069 fbranch-target-load-optimize
1070 Common Report Var(flag_branch_target_load_optimize) Optimization
1071 Perform branch target load optimization before prologue / epilogue threading.
1073 fbranch-target-load-optimize2
1074 Common Report Var(flag_branch_target_load_optimize2) Optimization
1075 Perform branch target load optimization after prologue / epilogue threading.
1078 Common Report Var(flag_btr_bb_exclusive) Optimization
1079 Restrict target load migration not to re-use registers in any basic block.
1082 Common Joined RejectNegative Var(common_deferred_options) Defer
1083 -fcall-saved-<register> Mark <register> as being preserved across functions.
1086 Common Joined RejectNegative Var(common_deferred_options) Defer
1087 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1089 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1090 ; be saved across function calls, if that produces overall better code.
1091 ; Optional now, so people can test it.
1093 Common Report Var(flag_caller_saves) Optimization
1094 Save registers around function calls.
1097 Common Report Var(flag_check_data_deps)
1098 This switch is deprecated; do not use.
1101 Common Var(flag_check_new)
1102 Check the return value of new in C++.
1105 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1106 Perform internal consistency checkings.
1109 Common Joined RejectNegative UInteger Var(flag_checking)
1110 Perform internal consistency checkings.
1113 Common Report Var(flag_code_hoisting) Optimization
1114 Enable code hoisting.
1116 fcombine-stack-adjustments
1117 Common Report Var(flag_combine_stack_adjustments) Optimization
1118 Looks for opportunities to reduce stack adjustments and stack references.
1121 Common Report Var(flag_no_common,0)
1122 Do not put uninitialized globals in the common section.
1126 ; Converted by the driver to -fcompare-debug= options.
1129 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1130 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1132 fcompare-debug-second
1133 Common Driver RejectNegative Var(flag_compare_debug)
1134 Run only the second compilation of -fcompare-debug.
1137 Common Report Var(flag_compare_elim_after_reload) Optimization
1138 Perform comparison elimination after register allocation has finished.
1141 Common Var(flag_conserve_stack) Optimization
1142 Do not perform optimizations increasing noticeably stack usage.
1145 Common Report Var(flag_cprop_registers) Optimization
1146 Perform a register copy-propagation optimization pass.
1149 Common Report Var(flag_crossjumping) Optimization
1150 Perform cross-jumping optimization.
1153 Common Report Var(flag_cse_follow_jumps) Optimization
1154 When running CSE, follow jumps to their targets.
1158 Does nothing. Preserved for backward compatibility.
1161 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1162 Omit range reduction step when performing complex division.
1165 Common Report Var(flag_cx_fortran_rules) Optimization
1166 Complex multiplication and division follow Fortran rules.
1169 Common Report Var(flag_data_sections)
1170 Place data items into their own section.
1173 Common Report Var(common_deferred_options) Defer
1174 List all available debugging counters with their limits and counts.
1177 Common RejectNegative Joined Var(common_deferred_options) Defer
1178 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1181 Common Joined RejectNegative Var(common_deferred_options) Defer
1182 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1185 Common Joined RejectNegative Var(common_deferred_options) Defer
1186 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1188 fdebug-types-section
1189 Common Report Var(flag_debug_types_section) Init(0)
1190 Output .debug_types section when using DWARF v4 debuginfo.
1192 ; Nonzero for -fdefer-pop: don't pop args after each function call
1193 ; instead save them up to pop many calls' args with one insns.
1195 Common Report Var(flag_defer_pop) Optimization
1196 Defer popping functions args from stack until later.
1199 Common Report Var(flag_delayed_branch) Optimization
1200 Attempt to fill delay slots of branch instructions.
1202 fdelete-dead-exceptions
1203 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1204 Delete dead instructions that may throw exceptions.
1206 fdelete-null-pointer-checks
1207 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1208 Delete useless null pointer checks.
1210 fdevirtualize-at-ltrans
1211 Common Report Var(flag_ltrans_devirtualize)
1212 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1214 fdevirtualize-speculatively
1215 Common Report Var(flag_devirtualize_speculatively) Optimization
1216 Perform speculative devirtualization.
1219 Common Report Var(flag_devirtualize) Optimization
1220 Try to convert virtual calls to direct ones.
1222 fdiagnostics-show-location=
1223 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1224 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1226 ; Required for these enum values.
1231 Name(diagnostic_prefixing_rule) Type(int)
1234 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1237 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1239 fdiagnostics-show-caret
1240 Common Var(flag_diagnostics_show_caret) Init(1)
1241 Show the source line with a caret indicating the column.
1244 Common Alias(fdiagnostics-color=,always,never)
1248 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1249 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1251 ; Required for these enum values.
1256 Name(diagnostic_color_rule) Type(int)
1259 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1262 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1265 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1267 fdiagnostics-parseable-fixits
1268 Common Var(flag_diagnostics_parseable_fixits)
1269 Print fix-it hints in machine-readable form.
1271 fdiagnostics-generate-patch
1272 Common Var(flag_diagnostics_generate_patch)
1273 Print fix-it hints to stderr in unified diff format.
1275 fdiagnostics-show-option
1276 Common Var(flag_diagnostics_show_option) Init(1)
1277 Amend appropriate diagnostic messages with the command line option that controls them.
1280 Common Joined RejectNegative Var(common_deferred_options) Defer
1281 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1284 Common Joined RejectNegative Var(common_deferred_options) Defer
1285 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1288 Common Joined RejectNegative Var(common_deferred_options) Defer
1289 -fdump-<type> Dump various compiler internals to a file.
1292 Driver RejectNegative
1295 Common RejectNegative Joined Var(flag_dump_final_insns)
1296 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1299 Common RejectNegative Joined Var(flag_dump_go_spec)
1300 -fdump-go-spec=filename Write all declarations to file as Go code.
1303 Common Report Var(flag_dump_noaddr)
1304 Suppress output of addresses in debugging dumps.
1307 Common Driver Var(flag_report_bug)
1308 Collect and dump debug information into temporary file if ICE in C/C++
1311 fdump-internal-locations
1312 Common Var(flag_dump_locations) Init(0)
1313 Dump detailed information on GCC's internal representation of source code locations.
1316 Common Var(flag_dump_passes) Init(0)
1317 Dump optimization passes.
1320 Common Report Var(flag_dump_unnumbered)
1321 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1323 fdump-unnumbered-links
1324 Common Report Var(flag_dump_unnumbered_links)
1325 Suppress output of previous and next insn numbers in debugging dumps.
1328 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1329 Enable CFI tables via GAS assembler directives.
1332 Common Report Var(flag_early_inlining) Init(1) Optimization
1333 Perform early inlining.
1335 feliminate-dwarf2-dups
1337 Does nothing. Preserved for backward compatibility.
1340 Common Report Var(flag_ipa_sra) Init(0) Optimization
1341 Perform interprocedural reduction of aggregates.
1343 feliminate-unused-debug-symbols
1344 Common Report Var(flag_debug_only_used_symbols)
1345 Perform unused symbol elimination in debug info.
1347 feliminate-unused-debug-types
1348 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1349 Perform unused type elimination in debug info.
1351 femit-class-debug-always
1352 Common Report Var(flag_emit_class_debug_always) Init(0)
1353 Do not suppress C++ class debug information.
1356 Common Report Var(flag_exceptions) Optimization
1357 Enable exception handling.
1359 fexpensive-optimizations
1360 Common Report Var(flag_expensive_optimizations) Optimization
1361 Perform a number of minor, expensive optimizations.
1364 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1365 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1368 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1371 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1374 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1376 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1377 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1378 fpermitted-flt-eval-methods=
1379 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1380 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1383 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)
1386 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1389 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1395 Common Var(flag_fat_lto_objects)
1396 Output lto objects containing both the intermediate language and binary output.
1399 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1400 Assume no NaNs or infinities are generated.
1403 Common Joined RejectNegative Var(common_deferred_options) Defer
1404 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1407 Common Report Var(flag_float_store) Optimization
1408 Don't allocate floats and doubles in extended-precision registers.
1412 Does nothing. Preserved for backward compatibility.
1415 Common Report Var(flag_forward_propagate) Optimization
1416 Perform a forward propagation pass on RTL.
1419 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1420 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1423 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1426 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1428 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1430 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1433 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1435 ffp-int-builtin-inexact
1436 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1437 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1439 ; Nonzero means don't put addresses of constant functions in registers.
1440 ; Used for compiling the Unix kernel, where strange substitutions are
1441 ; done on the assembly output.
1443 Common Report Var(flag_no_function_cse,0) Optimization
1444 Allow function addresses to be held in registers.
1447 Common Report Var(flag_function_sections)
1448 Place each function into its own section.
1451 Common Report Var(flag_gcse) Optimization
1452 Perform global common subexpression elimination.
1455 Common Report Var(flag_gcse_lm) Init(1) Optimization
1456 Perform enhanced load motion during global common subexpression elimination.
1459 Common Report Var(flag_gcse_sm) Init(0) Optimization
1460 Perform store motion after global common subexpression elimination.
1463 Common Report Var(flag_gcse_las) Init(0) Optimization
1464 Perform redundant load after store elimination in global common subexpression
1468 Common Report Var(flag_gcse_after_reload) Optimization
1469 Perform global common subexpression elimination after register allocation has
1473 Name(dwarf_gnat_encodings) Type(int)
1476 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1479 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1482 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1485 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1486 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1488 ; This option is not documented yet as its semantics will change.
1490 Common Report Var(flag_graphite) Optimization
1491 Enable in and out of Graphite representation.
1494 Common Report Var(flag_graphite_identity) Optimization
1495 Enable Graphite Identity transformation.
1497 fhoist-adjacent-loads
1498 Common Report Var(flag_hoist_adjacent_loads) Optimization
1499 Enable hoisting adjacent loads to encourage generating conditional move
1503 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1504 ; Always keep a pointer to a live memory block
1506 floop-parallelize-all
1507 Common Report Var(flag_loop_parallelize_all) Optimization
1508 Mark all loops as parallel.
1511 Common Alias(floop-nest-optimize)
1512 Enable loop nest transforms. Same as -floop-nest-optimize.
1515 Common Report Var(flag_loop_interchange) Optimization
1516 Enable loop interchange on trees.
1519 Common Alias(floop-nest-optimize)
1520 Enable loop nest transforms. Same as -floop-nest-optimize.
1522 floop-unroll-and-jam
1523 Common Report Var(flag_unroll_jam) Optimization
1524 Perform unroll-and-jam on loops.
1527 Common Report Var(flag_tm)
1528 Enable support for GNU transactional memory.
1531 Common Report Var(flag_gnu_unique) Init(1)
1532 Use STB_GNU_UNIQUE if supported by the assembler.
1536 Does nothing. Preserved for backward compatibility.
1539 Common Report Var(flag_loop_nest_optimize) Optimization
1540 Enable the loop nest optimizer.
1542 fstrict-volatile-bitfields
1543 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1544 Force bitfield accesses to match their type width.
1547 Common Report Var(flag_store_merging) Optimization
1548 Merge adjacent stores.
1550 fguess-branch-probability
1551 Common Report Var(flag_guess_branch_prob) Optimization
1552 Enable guessing of branch probabilities.
1554 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1555 ; Generate position-independent code for executables if possible
1556 ; On SVR4 targets, it also controls whether or not to emit a
1557 ; string identifying the compiler.
1559 Common Report Var(flag_no_ident,0)
1560 Process #ident directives.
1563 Common Report Var(flag_if_conversion) Optimization
1564 Perform conversion of conditional jumps to branchless equivalents.
1567 Common Report Var(flag_if_conversion2) Optimization
1568 Perform conversion of conditional jumps to conditional execution.
1571 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1572 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1575 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1578 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1581 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1584 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1586 ftree-loop-if-convert
1587 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1588 Convert conditional jumps in innermost loops to branchless equivalents.
1590 ftree-loop-if-convert-stores
1592 Does nothing. Preserved for backward compatibility.
1594 ; -finhibit-size-directive inhibits output of .size for ELF.
1595 ; This is used only for compiling crtstuff.c,
1596 ; and it may be extended to other effects
1597 ; needed for crtstuff.c on other systems.
1598 finhibit-size-directive
1599 Common Report Var(flag_inhibit_size_directive)
1600 Do not generate .size directives.
1603 Common Report Var(flag_indirect_inlining) Optimization
1604 Perform indirect inlining.
1606 ; General flag to enable inlining. Specifying -fno-inline will disable
1607 ; all inlining apart from always-inline functions.
1609 Common Report Var(flag_no_inline,0) Init(0) Optimization
1610 Enable inlining of function declared \"inline\", disabling disables all inlining.
1612 finline-small-functions
1613 Common Report Var(flag_inline_small_functions) Optimization
1614 Integrate functions into their callers when code size is known not to grow.
1617 Common Report Var(flag_inline_functions) Optimization
1618 Integrate functions not declared \"inline\" into their callers when profitable.
1620 finline-functions-called-once
1621 Common Report Var(flag_inline_functions_called_once) Optimization
1622 Integrate functions only required by their single caller.
1625 Common RejectNegative Joined Alias(finline-limit=)
1628 Common RejectNegative Joined UInteger
1629 -finline-limit=<number> Limit the size of inlined functions to <number>.
1632 Common Report Var(flag_inline_atomics) Init(1) Optimization
1633 Inline __atomic operations when a lock free instruction sequence is available.
1636 Common RejectNegative Alias(fcf-protection=,full)
1639 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1640 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1641 instructions have valid targets.
1644 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1647 Enum(cf_protection_level) String(full) Value(CF_FULL)
1650 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1653 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1656 Enum(cf_protection_level) String(none) Value(CF_NONE)
1658 finstrument-functions
1659 Common Report Var(flag_instrument_function_entry_exit)
1660 Instrument function entry and exit with profiling calls.
1662 finstrument-functions-exclude-function-list=
1663 Common RejectNegative Joined
1664 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1666 finstrument-functions-exclude-file-list=
1667 Common RejectNegative Joined
1668 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1671 Common Report Var(flag_ipa_cp) Optimization
1672 Perform interprocedural constant propagation.
1675 Common Report Var(flag_ipa_cp_clone) Optimization
1676 Perform cloning to make Interprocedural constant propagation stronger.
1680 Does nothing. Preserved for backward compatibility.
1683 Common Report Var(flag_ipa_bit_cp) Optimization
1684 Perform interprocedural bitwise constant propagation.
1687 Common Report Var(flag_ipa_profile) Init(0) Optimization
1688 Perform interprocedural profile propagation.
1691 Common Report Var(flag_ipa_pta) Init(0) Optimization
1692 Perform interprocedural points-to analysis.
1695 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1696 Discover pure and const functions.
1699 Common Report Var(flag_ipa_icf) Optimization
1700 Perform Identical Code Folding for functions and read-only variables.
1703 Common Report Var(flag_ipa_icf_functions) Optimization
1704 Perform Identical Code Folding for functions.
1707 Common Report Var(flag_ipa_icf_variables) Optimization
1708 Perform Identical Code Folding for variables.
1711 Common Report Var(flag_ipa_reference) Init(0) Optimization
1712 Discover readonly and non addressable static variables.
1716 Does nothing. Preserved for backward compatibility.
1720 Does nothing. Preserved for backward compatibility.
1723 Common Report Var(flag_ipa_vrp) Optimization
1724 Perform IPA Value Range Propagation.
1727 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1728 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1731 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1734 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1737 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1740 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1741 -fira-region=[one|all|mixed] Set regions for IRA.
1744 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1747 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1750 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1753 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1756 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1757 Use IRA based register pressure calculation
1758 in RTL hoist optimizations.
1761 Common Report Var(flag_ira_loop_pressure) Optimization
1762 Use IRA based register pressure calculation
1763 in RTL loop optimizations.
1765 fira-share-save-slots
1766 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1767 Share slots for saving different hard registers.
1769 fira-share-spill-slots
1770 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1771 Share stack slots for spilled pseudo-registers.
1774 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1775 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1778 Common Report Var(flag_ivopts) Init(1) Optimization
1779 Optimize induction variables on trees.
1782 Common Var(flag_jump_tables) Init(1) Optimization
1783 Use jump tables for sufficiently large switch statements.
1785 fkeep-inline-functions
1786 Common Report Var(flag_keep_inline_functions)
1787 Generate code for functions even if they are fully inlined.
1789 fkeep-static-functions
1790 Common Report Var(flag_keep_static_functions)
1791 Generate code for static functions even if they are never called.
1794 Common Report Var(flag_keep_static_consts) Init(1)
1795 Emit static const variables even if they are not used.
1798 Common Report Var(flag_leading_underscore) Init(-1)
1799 Give external symbols a leading underscore.
1803 Does nothing. Preserved for backward compatibility.
1806 Common Report Var(flag_lra_remat) Optimization
1807 Do CFG-sensitive rematerialization in LRA.
1811 Enable link-time optimization.
1814 Common RejectNegative Joined Var(flag_lto)
1815 Link-time optimization with number of parallel jobs or jobserver.
1818 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1821 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1824 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1827 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1830 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1833 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1836 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1837 Specify the algorithm to partition symbols and vars at linktime.
1839 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1840 flto-compression-level=
1841 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1842 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1844 flto-odr-type-merging
1845 Common Report Var(flag_lto_odr_type_mering) Init(1)
1846 Merge C++ types using One Definition Rule.
1849 Common Report Var(flag_lto_report) Init(0)
1850 Report various link-time optimization statistics.
1853 Common Report Var(flag_lto_report_wpa) Init(0)
1854 Report various link-time optimization statistics for WPA only.
1857 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1858 Set errno after built-in math functions.
1861 Common Joined RejectNegative UInteger Var(flag_max_errors)
1862 -fmax-errors=<number> Maximum number of errors to report.
1865 Common Report Var(mem_report)
1866 Report on permanent memory allocation.
1869 Common Report Var(mem_report_wpa)
1870 Report on permanent memory allocation in WPA only.
1872 ; This will attempt to merge constant section constants, if 1 only
1873 ; string constants and constants from constant pool, if 2 also constant
1875 fmerge-all-constants
1876 Common Report Var(flag_merge_constants,2) Init(1)
1877 Attempt to merge identical constants and constant variables.
1880 Common Report Var(flag_merge_constants,1)
1881 Attempt to merge identical constants across compilation units.
1883 fmerge-debug-strings
1884 Common Report Var(flag_merge_debug_strings) Init(1)
1885 Attempt to merge identical debug strings across compilation units.
1888 Common RejectNegative Joined UInteger
1889 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1892 Common Report Var(flag_modulo_sched) Optimization
1893 Perform SMS based modulo scheduling before the first scheduling pass.
1895 fmodulo-sched-allow-regmoves
1896 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1897 Perform SMS based modulo scheduling with register moves allowed.
1899 fmove-loop-invariants
1900 Common Report Var(flag_move_loop_invariants) Optimization
1901 Move loop invariant computations out of loops.
1904 Common Var(flag_dce) Init(1) Optimization
1905 Use the RTL dead code elimination pass.
1908 Common Var(flag_dse) Init(1) Optimization
1909 Use the RTL dead store elimination pass.
1911 freschedule-modulo-scheduled-loops
1912 Common Report Var(flag_resched_modulo_sched) Optimization
1913 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1915 fnon-call-exceptions
1916 Common Report Var(flag_non_call_exceptions) Optimization
1917 Support synchronous non-call exceptions.
1920 Common Driver Joined MissingArgError(options or targets missing after %qs)
1921 -foffload=<targets>=<options> Specify offloading targets and options for them.
1924 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1925 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1928 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1931 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1934 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1937 Common Report Var(flag_omit_frame_pointer) Optimization
1938 When possible do not generate stack frames.
1941 Common Report Var(flag_opt_info) Optimization
1942 Enable all optimization info dumps on stderr.
1945 Common Joined RejectNegative Var(common_deferred_options) Defer
1946 -fopt-info[-<type>=filename] Dump compiler optimization details.
1948 foptimize-register-move
1950 Does nothing. Preserved for backward compatibility.
1952 foptimize-sibling-calls
1953 Common Report Var(flag_optimize_sibling_calls) Optimization
1954 Optimize sibling and tail recursive calls.
1957 Common Report Var(flag_partial_inlining) Optimization
1958 Perform partial inlining.
1961 Common Report Var(pre_ipa_mem_report)
1962 Report on memory allocation before interprocedural optimization.
1964 fpost-ipa-mem-report
1965 Common Report Var(post_ipa_mem_report)
1966 Report on memory allocation before interprocedural optimization.
1969 Common Report Var(flag_pack_struct) Optimization
1970 Pack structure members together without holes.
1973 Common RejectNegative Joined UInteger Optimization
1974 -fpack-struct=<number> Set initial maximum structure member alignment.
1977 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1978 Return small aggregates in memory, not registers.
1981 Common Report Var(flag_peel_loops) Optimization
1982 Perform loop peeling.
1985 Common Report Var(flag_no_peephole,0) Optimization
1986 Enable machine specific peephole optimizations.
1989 Common Report Var(flag_peephole2) Optimization
1990 Enable an RTL peephole pass before sched2.
1993 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1994 Generate position-independent code if possible (large mode).
1997 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1998 Generate position-independent code for executables if possible (large mode).
2001 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2002 Generate position-independent code if possible (small mode).
2005 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2006 Generate position-independent code for executables if possible (small mode).
2009 Common Report Var(flag_plt) Init(1) Optimization
2010 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2013 Common Joined RejectNegative Var(common_deferred_options) Defer
2014 Specify a plugin to load.
2017 Common Joined RejectNegative Var(common_deferred_options) Defer
2018 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2020 fpredictive-commoning
2021 Common Report Var(flag_predictive_commoning) Optimization
2022 Run predictive commoning optimization.
2024 fprefetch-loop-arrays
2025 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2026 Generate prefetch instructions, if available, for arrays in loops.
2029 Common Report Var(profile_flag)
2030 Enable basic program profiling code.
2033 Common Report Var(profile_abs_path_flag)
2034 Generate absolute source path names for gcov.
2037 Common Report Var(profile_arc_flag)
2038 Insert arc-based program profiling code.
2041 Common Joined RejectNegative Var(profile_data_prefix)
2042 Set the top-level directory for storing the profile data.
2043 The default is 'pwd'.
2046 Common Report Var(flag_profile_correction)
2047 Enable correction of flow inconsistent profile data input.
2050 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2051 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2054 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2057 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2060 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2063 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2067 Enable common options for generating profile info for profile feedback directed optimizations.
2070 Common Joined RejectNegative
2071 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2074 Common Var(flag_profile_use)
2075 Enable common options for performing profile feedback directed optimizations.
2078 Common Joined RejectNegative
2079 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2082 Common Report Var(flag_profile_values)
2083 Insert code to profile values of expressions.
2086 Common Report Var(profile_report)
2087 Report on consistency of profile.
2089 fprofile-reorder-functions
2090 Common Report Var(flag_profile_reorder_functions)
2091 Enable function reordering that improves code placement.
2093 fpatchable-function-entry=
2094 Common Joined Optimization
2095 Insert NOP instructions at each function entry.
2098 Common Var(common_deferred_options) Defer
2101 Common Joined RejectNegative Var(common_deferred_options) Defer
2102 -frandom-seed=<string> Make compile reproducible using <string>.
2104 ; This switch causes the command line that was used to create an
2105 ; object file to be recorded into the object file. The exact format
2106 ; of this recording is target and binary file format dependent.
2107 ; It is related to the -fverbose-asm switch, but that switch only
2108 ; records information in the assembler output file as comments, so
2109 ; they never reach the object file.
2110 frecord-gcc-switches
2111 Common Report Var(flag_record_gcc_switches)
2112 Record gcc command line switches in the object file.
2115 Common Report Var(flag_pcc_struct_return,0) Optimization
2116 Return small aggregates in registers.
2120 Does nothing. Preserved for backward compatibility.
2123 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2124 Tell DSE that the storage for a C++ object is dead when the constructor
2125 starts and when the destructor finishes.
2128 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2130 flive-range-shrinkage
2131 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2132 Relief of register pressure through live range shrinkage.
2135 Common Report Var(flag_rename_registers) Init(2) Optimization
2136 Perform a register renaming optimization pass.
2139 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2140 Perform a target dependent instruction fusion optimization pass.
2143 Common Report Var(flag_reorder_blocks) Optimization
2144 Reorder basic blocks to improve code placement.
2146 freorder-blocks-algorithm=
2147 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2148 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2151 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2154 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2157 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2159 freorder-blocks-and-partition
2160 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2161 Reorder basic blocks and partition into hot and cold sections.
2164 Common Report Var(flag_reorder_functions) Optimization
2165 Reorder functions to improve code placement.
2167 frerun-cse-after-loop
2168 Common Report Var(flag_rerun_cse_after_loop) Optimization
2169 Add a common subexpression elimination pass after loop optimizations.
2173 Does nothing. Preserved for backward compatibility.
2176 Common Report Var(flag_rounding_math) Optimization SetByCombined
2177 Disable optimizations that assume default FP rounding behavior.
2180 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2181 Enable scheduling across basic blocks.
2184 Common Report Var(flag_sched_pressure) Init(0) Optimization
2185 Enable register pressure sensitive insn scheduling.
2188 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2189 Allow speculative motion of non-loads.
2192 Common Report Var(flag_schedule_speculative_load) Optimization
2193 Allow speculative motion of some loads.
2195 fsched-spec-load-dangerous
2196 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2197 Allow speculative motion of more loads.
2200 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2201 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2203 fsched2-use-superblocks
2204 Common Report Var(flag_sched2_use_superblocks) Optimization
2205 If scheduling post reload, do superblock scheduling.
2209 Does nothing. Preserved for backward compatibility.
2212 Common Report Var(flag_schedule_insns) Optimization
2213 Reschedule instructions before register allocation.
2216 Common Report Var(flag_schedule_insns_after_reload) Optimization
2217 Reschedule instructions after register allocation.
2219 ; This flag should be on when a target implements non-trivial
2220 ; scheduling hooks, maybe saving some information for its own sake.
2221 ; On IA64, for example, this is used for correct bundling.
2222 fselective-scheduling
2223 Common Report Var(flag_selective_scheduling) Optimization
2224 Schedule instructions using selective scheduling algorithm.
2226 fselective-scheduling2
2227 Common Report Var(flag_selective_scheduling2) Optimization
2228 Run selective scheduling after reload.
2231 Common Undocumented Joined Var(flag_self_test)
2232 Run self-tests, using the given path to locate test files.
2234 fsel-sched-pipelining
2235 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2236 Perform software pipelining of inner loops during selective scheduling.
2238 fsel-sched-pipelining-outer-loops
2239 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2240 Perform software pipelining of outer loops during selective scheduling.
2242 fsel-sched-reschedule-pipelined
2243 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2244 Reschedule pipelined regions without pipelining.
2246 fsemantic-interposition
2247 Common Report Var(flag_semantic_interposition) Init(1)
2248 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2250 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2251 ; of stalled insns into the ready list.
2252 fsched-stalled-insns
2253 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2254 Allow premature scheduling of queued insns.
2256 fsched-stalled-insns=
2257 Common RejectNegative Joined UInteger Optimization
2258 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2260 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2261 ; be examined for a dependency on a stalled insn that is candidate for
2262 ; premature removal from the queue of stalled insns into the ready list (has
2263 ; an effect only if the flag 'sched_stalled_insns' is set).
2264 fsched-stalled-insns-dep
2265 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2266 Set dependence distance checking in premature scheduling of queued insns.
2268 fsched-stalled-insns-dep=
2269 Common RejectNegative Joined UInteger Optimization
2270 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2272 fsched-group-heuristic
2273 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2274 Enable the group heuristic in the scheduler.
2276 fsched-critical-path-heuristic
2277 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2278 Enable the critical path heuristic in the scheduler.
2280 fsched-spec-insn-heuristic
2281 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2282 Enable the speculative instruction heuristic in the scheduler.
2284 fsched-rank-heuristic
2285 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2286 Enable the rank heuristic in the scheduler.
2288 fsched-last-insn-heuristic
2289 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2290 Enable the last instruction heuristic in the scheduler.
2292 fsched-dep-count-heuristic
2293 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2294 Enable the dependent count heuristic in the scheduler.
2297 Common Report Var(flag_section_anchors) Optimization
2298 Access data in the same section from shared anchor points.
2302 Does nothing. Preserved for backward compatibility.
2306 Does nothing. Preserved for backward compatibility.
2309 Common Report Var(flag_ree) Init(0)
2310 Turn on Redundant Extensions Elimination pass.
2313 Common Report Var(flag_show_column) Init(1)
2314 Show column numbers in diagnostics, when available. Default on.
2317 Common Report Var(flag_shrink_wrap) Optimization
2318 Emit function prologues only before parts of the function that need it,
2319 rather than at the top of the function.
2321 fshrink-wrap-separate
2322 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2323 Shrink-wrap parts of the prologue and epilogue separately.
2326 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2327 Disable optimizations observable by IEEE signaling NaNs.
2330 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2331 Disable floating point optimizations that ignore the IEEE signedness of zero.
2333 fsingle-precision-constant
2334 Common Report Var(flag_single_precision_constant) Optimization
2335 Convert floating point constants to single precision constants.
2337 fsplit-ivs-in-unroller
2338 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2339 Split lifetimes of induction variables when loops are unrolled.
2342 Common Report Var(flag_split_stack) Init(-1)
2343 Generate discontiguous stack frames.
2346 Common Report Var(flag_split_wide_types) Optimization
2347 Split wide types into independent registers.
2350 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2351 Enable backward propagation of use properties at the SSA level.
2354 Common Report Var(flag_ssa_phiopt) Optimization
2355 Optimize conditional patterns using SSA PHI nodes.
2358 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2359 Optimize amount of stdarg registers saved to stack at start of function.
2361 fvariable-expansion-in-unroller
2362 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2363 Apply variable expansion when loops are unrolled.
2366 Common Report RejectNegative Joined Optimization
2367 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2370 Common Alias(fstack-check=, specific, no)
2371 Insert stack checking code into the program. Same as -fstack-check=specific.
2373 fstack-clash-protection
2374 Common Report Var(flag_stack_clash_protection) Optimization
2375 Insert code to probe each page of stack space as it is allocated to protect
2376 from stack-clash style attacks.
2379 Common Var(common_deferred_options) Defer
2381 fstack-limit-register=
2382 Common RejectNegative Joined Var(common_deferred_options) Defer
2383 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2385 fstack-limit-symbol=
2386 Common RejectNegative Joined Var(common_deferred_options) Defer
2387 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2390 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2391 Use propolice as a stack protection method.
2393 fstack-protector-all
2394 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2395 Use a stack protection method for every function.
2397 fstack-protector-strong
2398 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2399 Use a smart stack protection method for certain functions.
2401 fstack-protector-explicit
2402 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2403 Use stack protection method only for functions with the stack_protect attribute.
2406 Common RejectNegative Var(flag_stack_usage)
2407 Output stack usage information on a per-function basis.
2411 Does nothing. Preserved for backward compatibility.
2413 ; Nonzero if we should do (language-dependent) alias analysis.
2414 ; Typically, this analysis will assume that expressions of certain
2415 ; types do not alias expressions of certain other types. Only used
2416 ; if alias analysis (in general) is enabled.
2418 Common Report Var(flag_strict_aliasing) Optimization
2419 Assume strict aliasing rules apply.
2423 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2426 Common Report Var(flag_sync_libcalls) Init(1)
2427 Implement __atomic operations via libcalls to legacy __sync functions.
2430 Common Report Var(flag_syntax_only)
2431 Check for syntax errors, then stop.
2434 Common Report Var(flag_test_coverage)
2435 Create data files needed by \"gcov\".
2438 Common Report Var(flag_thread_jumps) Optimization
2439 Perform jump threading optimizations.
2442 Common Report Var(time_report)
2443 Report the time taken by each compiler pass.
2445 ftime-report-details
2446 Common Report Var(time_report_details)
2447 Record times taken by sub-phases separately.
2450 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2451 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2454 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2457 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2460 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2463 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2466 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2469 Common Report Var(flag_toplevel_reorder) Init(2)
2470 Reorder top level functions, variables, and asms.
2473 Common Report Var(flag_tracer) Optimization
2474 Perform superblock formation via tail duplication.
2477 Common Report Var(flag_trampolines) Init(0)
2478 For targets that normally need trampolines for nested functions, always
2479 generate them instead of using descriptors.
2481 ; Zero means that floating-point math operations cannot generate a
2482 ; (user-visible) trap. This is the case, for example, in nonstop
2483 ; IEEE 754 arithmetic.
2485 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2486 Assume floating-point operations can trap.
2489 Common Report Var(flag_trapv) Optimization
2490 Trap for signed overflow in addition, subtraction and multiplication.
2493 Common Report Var(flag_tree_ccp) Optimization
2494 Enable SSA-CCP optimization on trees.
2497 Common Report Var(flag_tree_bit_ccp) Optimization
2498 Enable SSA-BIT-CCP optimization on trees.
2502 Does nothing. Preserved for backward compatibility.
2505 Common Report Var(flag_tree_ch) Optimization
2506 Enable loop header copying on trees.
2508 ftree-coalesce-inlined-vars
2509 Common Ignore RejectNegative
2510 Does nothing. Preserved for backward compatibility.
2513 Common Report Var(flag_tree_coalesce_vars) Optimization
2514 Enable SSA coalescing of user variables.
2518 Does nothing. Preserved for backward compatibility.
2521 Common Report Var(flag_tree_copy_prop) Optimization
2522 Enable copy propagation on trees.
2524 ftree-store-copy-prop
2526 Does nothing. Preserved for backward compatibility.
2529 Common Report Var(flag_tree_cselim) Init(2) Optimization
2530 Transform condition stores into unconditional ones.
2532 ftree-switch-conversion
2533 Common Report Var(flag_tree_switch_conversion) Optimization
2534 Perform conversions of switch initializations.
2537 Common Report Var(flag_tree_dce) Optimization
2538 Enable SSA dead code elimination optimization on trees.
2540 ftree-dominator-opts
2541 Common Report Var(flag_tree_dom) Optimization
2542 Enable dominator optimizations.
2545 Common Report Var(flag_tree_tail_merge) Optimization
2546 Enable tail merging on trees.
2549 Common Report Var(flag_tree_dse) Optimization
2550 Enable dead store elimination.
2553 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2554 Enable forward propagation on trees.
2557 Common Report Var(flag_tree_fre) Optimization
2558 Enable Full Redundancy Elimination (FRE) on trees.
2561 Common Report Var(flag_optimize_strlen) Optimization
2562 Enable string length optimizations on trees.
2564 fisolate-erroneous-paths-dereference
2565 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2566 Detect paths that trigger erroneous or undefined behavior due to
2567 dereferencing a null pointer. Isolate those paths from the main control
2568 flow and turn the statement with erroneous or undefined behavior into a trap.
2570 fisolate-erroneous-paths-attribute
2571 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2572 Detect paths that trigger erroneous or undefined behavior due to a null value
2573 being used in a way forbidden by a returns_nonnull or nonnull
2574 attribute. Isolate those paths from the main control flow and turn the
2575 statement with erroneous or undefined behavior into a trap.
2577 ftree-loop-distribution
2578 Common Report Var(flag_tree_loop_distribution) Optimization
2579 Enable loop distribution on trees.
2581 ftree-loop-distribute-patterns
2582 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2583 Enable loop distribution for patterns transformed into a library call.
2586 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2587 Enable loop invariant motion on trees.
2590 Common Alias(floop-nest-optimize)
2591 Enable loop nest transforms. Same as -floop-nest-optimize.
2594 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2595 Create canonical induction variables in loops.
2598 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2599 Enable loop optimizations on tree level.
2601 ftree-parallelize-loops=
2602 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2603 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2606 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2607 Enable hoisting loads from conditional pointers.
2610 Common Report Var(flag_tree_pre) Optimization
2611 Enable SSA-PRE optimization on trees.
2614 Common Report Var(flag_tree_partial_pre) Optimization
2615 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2618 Common Report Var(flag_tree_pta) Optimization
2619 Perform function-local points-to analysis on trees.
2622 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2623 Enable reassociation on tree level.
2627 Does nothing. Preserved for backward compatibility.
2630 Common Report Var(flag_tree_sink) Optimization
2631 Enable SSA code sinking on trees.
2634 Common Report Var(flag_tree_slsr) Optimization
2635 Perform straight-line strength reduction.
2638 Common Report Var(flag_tree_sra) Optimization
2639 Perform scalar replacement of aggregates.
2642 Common Report Var(flag_tree_ter) Optimization
2643 Replace temporary expressions in the SSA->normal pass.
2646 Common Report Var(flag_tree_live_range_split) Optimization
2647 Perform live range splitting during the SSA->normal pass.
2650 Common Report Var(flag_tree_vrp) Init(0) Optimization
2651 Perform Value Range Propagation on trees.
2654 Common Report Var(flag_split_paths) Init(0) Optimization
2655 Split paths leading to loop backedges.
2657 funconstrained-commons
2658 Common Var(flag_unconstrained_commons) Optimization
2659 Assume common declarations may be overridden with ones with a larger
2663 Common Report Var(flag_unit_at_a_time) Init(1)
2664 Compile whole compilation unit at a time.
2667 Common Report Var(flag_unroll_loops) Optimization
2668 Perform loop unrolling when iteration count is known.
2671 Common Report Var(flag_unroll_all_loops) Optimization
2672 Perform loop unrolling for all loops.
2674 ; Nonzero means that loop optimizer may assume that the induction variables
2675 ; that control loops do not overflow and that the loops with nontrivial
2676 ; exit condition are not infinite
2677 funsafe-loop-optimizations
2679 Does nothing. Preserved for backward compatibility.
2682 Common Report Var(flag_associative_math) SetByCombined Optimization
2683 Allow optimization for floating-point arithmetic which may change the
2684 result of the operation due to rounding.
2687 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2688 Same as -fassociative-math for expressions which include division.
2690 ; Nonzero means that unsafe floating-point math optimizations are allowed
2691 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2692 ; are allowed to assume that their arguments and results are "normal"
2693 ; (e.g., nonnegative for SQRT).
2694 funsafe-math-optimizations
2695 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2696 Allow math optimizations that may violate IEEE or ISO standards.
2699 Common Report Var(flag_unswitch_loops) Optimization
2700 Perform loop unswitching.
2703 Common Report Var(flag_split_loops) Optimization
2704 Perform loop splitting.
2707 Common Report Var(flag_unwind_tables) Optimization
2708 Just generate unwind tables for exception handling.
2711 Common Driver Negative(fuse-ld=gold)
2712 Use the bfd linker instead of the default linker.
2715 Common Driver Negative(fuse-ld=bfd)
2716 Use the gold linker instead of the default linker.
2719 Common Undocumented Var(flag_use_linker_plugin)
2721 ; Positive if we should track variables, negative if we should run
2722 ; the var-tracking pass only to discard debug annotations, zero if
2723 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2724 ; will be set according to optimize, debug_info_level and debug_hooks
2725 ; in process_options ().
2727 Common Report Var(flag_var_tracking) Init(2) PerFunction
2728 Perform variable tracking.
2730 ; Positive if we should track variables at assignments, negative if
2731 ; we should run the var-tracking pass only to discard debug
2732 ; annotations. When flag_var_tracking_assignments ==
2733 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2734 fvar-tracking-assignments
2735 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2736 Perform variable tracking by annotating assignments.
2738 ; Nonzero if we should toggle flag_var_tracking_assignments after
2739 ; processing options and computing its default. */
2740 fvar-tracking-assignments-toggle
2741 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2742 Toggle -fvar-tracking-assignments.
2744 ; Positive if we should track uninitialized variables, negative if
2745 ; we should run the var-tracking pass only to discard debug
2746 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2747 ; will be set according to flag_var_tracking.
2748 fvar-tracking-uninit
2749 Common Report Var(flag_var_tracking_uninit) PerFunction
2750 Perform variable tracking and also tag variables that are uninitialized.
2752 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2754 Common Report Optimization
2755 Enable vectorization on trees.
2757 ftree-vectorizer-verbose=
2758 Common Joined RejectNegative Ignore
2759 Does nothing. Preserved for backward compatibility.
2761 ftree-loop-vectorize
2762 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2763 Enable loop vectorization on trees.
2766 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2767 Enable basic block vectorization (SLP) on trees.
2770 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2771 Specifies the cost model for vectorization.
2772 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2775 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2776 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2779 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2782 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2785 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2788 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2791 Common Alias(fvect-cost-model=,dynamic,unlimited)
2792 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2794 ftree-vect-loop-version
2796 Does nothing. Preserved for backward compatibility.
2799 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2800 Enable copy propagation of scalar-evolution information.
2802 ; -fverbose-asm causes extra commentary information to be produced in
2803 ; the generated assembly code (to make it more readable). This option
2804 ; is generally only of use to those who actually need to read the
2805 ; generated assembly code (perhaps while debugging the compiler itself).
2806 ; -fno-verbose-asm, the default, causes the extra information
2807 ; to not be added and is useful when comparing two assembler files.
2809 Common Report Var(flag_verbose_asm)
2810 Add extra commentary to assembler output.
2813 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2814 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2817 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2820 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2823 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2826 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2829 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2832 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2833 Validate vtable pointers before using them.
2836 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2839 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2842 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2845 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2848 Common Var(flag_vtv_counts)
2849 Output vtable verification counters.
2852 Common Var(flag_vtv_debug)
2853 Output vtable verification pointer sets information.
2856 Common Report Var(flag_value_profile_transformations) Optimization
2857 Use expression value profiles in optimizations.
2860 Common Report Var(flag_web) Init(2) Optimization
2861 Construct webs and split unrelated uses of single variable.
2863 ftree-builtin-call-dce
2864 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2865 Enable conditional dead code elimination for builtin calls.
2868 Common Report Var(flag_whole_program) Init(0)
2869 Perform whole program optimizations.
2872 Common Report Var(flag_wrapv_pointer) Optimization
2873 Assume pointer overflow wraps around.
2876 Common Report Var(flag_wrapv) Optimization
2877 Assume signed arithmetic overflow wraps around.
2879 fzero-initialized-in-bss
2880 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2881 Put zero initialized data in the bss section.
2884 Common Driver RejectNegative JoinedOrMissing
2885 Generate debug information in default format.
2888 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2889 Assume assembler support for (DWARF2+) .loc directives
2892 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2893 Assume assembler support for view in (DWARF2+) .loc directives
2896 Common Driver Ignore Warn(switch %qs no longer supported)
2897 Does nothing. Preserved for backward compatibility.
2900 Common Driver Ignore Warn(switch %qs no longer supported)
2901 Does nothing. Preserved for backward compatibility.
2904 Common Driver Ignore Warn(switch %qs no longer supported)
2905 Does nothing. Preserved for backward compatibility.
2908 Common Driver Ignore Warn(switch %qs no longer supported)
2909 Does nothing. Preserved for backward compatibility.
2912 Common Driver Var(debug_column_info,1) Init(1)
2913 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2916 Common Driver JoinedOrMissing Negative(gdwarf-)
2917 Generate debug information in default version of DWARF format.
2920 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2921 Generate debug information in DWARF v2 (or later) format.
2924 Common Driver JoinedOrMissing
2925 Generate debug information in default extended format.
2928 Common Driver Var(debug_inline_points) Init(2)
2929 Generate extended entry point information for inlined functions
2931 ginternal-reset-location-views
2932 Common Driver Var(debug_internal_reset_location_views) Init(2)
2933 Compute locview reset points based on insn length estimates
2936 RejectNegative Joined Undocumented
2937 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
2940 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2941 Don't generate DWARF pubnames and pubtypes sections.
2944 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2945 Generate DWARF pubnames and pubtypes sections.
2948 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2949 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2951 grecord-gcc-switches
2952 Common Driver Var(dwarf_record_gcc_switches) Init(1)
2953 Record gcc command line switches in DWARF DW_AT_producer.
2956 Common Driver Var(dwarf_split_debug_info) Init(0)
2957 Generate debug information in separate .dwo files.
2960 Common Driver JoinedOrMissing Negative(gstabs+)
2961 Generate debug information in STABS format.
2964 Common Driver JoinedOrMissing Negative(gvms)
2965 Generate debug information in extended STABS format.
2967 gstatement-frontiers
2968 Common Driver Var(debug_nonbind_markers_p) Init(2)
2969 Emit progressive recommended breakpoint locations.
2972 Common Driver Report Var(dwarf_strict) Init(0)
2973 Don't emit DWARF additions beyond selected version.
2976 Common Driver Report Var(flag_gtoggle)
2977 Toggle debug information generation.
2979 gvariable-location-views
2980 Common Driver Var(debug_variable_location_views, 1) Init(2)
2981 Augment variable location lists with progressive views.
2983 gvariable-location-views=incompat5
2984 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
2987 Common Driver JoinedOrMissing Negative(gxcoff)
2988 Generate debug information in VMS format.
2991 Common Driver JoinedOrMissing Negative(gxcoff+)
2992 Generate debug information in XCOFF format.
2995 Common Driver JoinedOrMissing Negative(gdwarf)
2996 Generate debug information in extended XCOFF format.
2999 Name(compressed_debug_sections) Type(int)
3001 ; Since -gz= is completely handled in specs, the values aren't used and we
3002 ; assign arbitrary constants.
3004 Enum(compressed_debug_sections) String(none) Value(0)
3007 Enum(compressed_debug_sections) String(zlib) Value(1)
3010 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3014 Generate compressed debug sections.
3017 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3018 -gz=<format> Generate compressed debug sections in format <format>.
3021 Driver Joined Separate
3024 Common Joined Var(plugindir_string) Init(0)
3025 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3028 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3029 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3032 Driver Joined Separate
3037 no-canonical-prefixes
3050 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3051 -o <file> Place output into <file>.
3054 Common Var(profile_flag)
3055 Enable function profiling.
3058 Driver Var(pass_exit_codes)
3061 Common Alias(Wpedantic)
3064 Common Var(flag_pedantic_errors)
3065 Like -pedantic but issue them as errors.
3071 Driver Var(use_pipes)
3074 Driver JoinedOrMissing Var(print_file_name)
3076 print-libgcc-file-name
3079 print-multi-directory
3080 Driver Var(print_multi_directory)
3083 Driver Var(print_multi_lib)
3085 print-multi-os-directory
3086 Driver Var(print_multi_os_directory)
3089 Driver Var(print_multiarch)
3092 Driver JoinedOrMissing Var(print_prog_name)
3095 Driver Var(print_search_dirs)
3098 Driver Var(print_sysroot)
3100 print-sysroot-headers-suffix
3101 Driver Var(print_sysroot_headers_suffix)
3104 Common Var(quiet_flag) RejectDriver
3105 Do not display functions compiled or elapsed time.
3123 Driver Var(report_times)
3126 Driver JoinedOrMissing
3129 Driver Joined Separate
3133 ; C option, but driver must not handle as "-u ndef".
3136 Common Driver Var(verbose_flag)
3137 Enable verbose output.
3140 Common Var(version_flag) RejectDriver
3141 Display the compiler's version.
3144 Common Var(inhibit_warnings)
3148 Driver Separate Var(wrapper_string)
3151 Driver Joined Separate
3154 Driver RejectNegative Negative(static-pie)
3155 Create a shared library.
3161 Driver Separate Alias(specs=)
3174 ; Documented for Fortran, but always accepted by driver.
3181 ; Documented for Go, but always accepted by driver.
3199 Driver RejectNegative Negative(shared)
3200 Don't create a dynamically linked position independent executable.
3203 Driver RejectNegative Negative(no-pie)
3204 Create a dynamically linked position independent executable.
3207 Driver RejectNegative Negative(pie)
3208 Create a static position independent executable.
3211 Driver Joined Separate
3214 Common Report Var(flag_ipa_ra) Optimization
3215 Use caller save register across calls if possible.
3217 ; This comment is to ensure we retain the blank line above.