1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2013 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 ; 0 means straightforward implementation of complex divide acceptable.
50 ; 1 means wide ranges of inputs must work for complex divide.
51 ; 2 means C99-like requirements for complex multiply and divide.
53 int flag_complex_method = 1
55 ; Nonzero if subexpressions must be evaluated from left-to-right.
57 int flag_evaluation_order = 0
59 ; Language specific warning pass for unused results.
61 bool flag_warn_unused_result = false
66 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
70 ; True to warn about any objects definitions whose size is larger
71 ; than N bytes. Also want about function definitions whose returned
72 ; values are larger than N bytes, where N is 'larger_than_size'.
77 HOST_WIDE_INT larger_than_size
79 ; True to warn about any function whose frame size is larger
82 bool warn_frame_larger_than
85 HOST_WIDE_INT frame_larger_than_size
87 ; Nonzero means we should be saving declaration info into a .X file.
89 int flag_gen_aux_info = 0
91 ; Nonzero if we are compiling code for a shared library, zero for
96 ; These two are really VEC(char_p,heap) *.
99 void *flag_instrument_functions_exclude_functions
102 void *flag_instrument_functions_exclude_files
104 ; Generic structs (e.g. templates not explicitly specialized)
105 ; may not have a compilation unit associated with them, and so
106 ; may need to be treated differently from ordinary structs.
108 ; Structs only handled by reference (indirectly), will also usually
109 ; not need as much debugging information.
112 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
117 ; True if we should exit after parsing options.
119 bool exit_after_options
121 ; Type(s) of debugging information we are producing (if any). See
122 ; flag-types.h for the definitions of the different possible types of
123 ; debugging information.
125 enum debug_info_type write_symbols = NO_DEBUG
127 ; Level of debugging information we are producing. See flag-types.h
128 ; for the definitions of the different possible levels.
130 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
132 ; Nonzero means use GNU-only extensions in the generated symbolic
133 ; debugging information. Currently, this only has an effect when
134 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
136 bool use_gnu_debug_info_extensions
138 ; Original value of maximum field alignment in bytes, specified via
139 ; -fpack-struct=<value>.
141 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
143 ; Type of stack check.
145 enum stack_check_type flag_stack_check = NO_STACK_CHECK
147 ; True if stack usage information needs to be computed.
149 bool flag_stack_usage_info = false
151 ; -dA causes debug commentary information to be produced in
152 ; the generated assembly code (to make it more readable). This option
153 ; is generally only of use to those who actually need to read the
154 ; generated assembly code (perhaps while debugging the compiler itself).
155 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
156 ; to be a catchall for printing debug information in the assembler file.
160 ; -dP causes the rtl to be emitted as a comment in assembly.
162 int flag_dump_rtl_in_asm
164 ; Whether -da was passed (used only in handle_common_deferred_options).
166 bool flag_dump_all_passed
168 ; Other flags saying which kinds of debugging dump have been requested.
171 int rtl_dump_and_exit
174 int flag_print_asm_name
176 ; Name of top-level original source file (what was input to cpp).
177 ; This comes from the #-command at the beginning of the actual input.
178 ; If there isn't any there, then this is the cc1 input file name.
180 const char *main_input_filename
182 ; Pointer to base name in main_input_filename, with directories and a
183 ; single final extension removed, and the length of this base
187 const char *main_input_basename
190 int main_input_baselength
192 ; Which options have been printed by --help.
196 ; Which enums have been printed by --help. 0 = not printed, no
197 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
200 char *help_enum_printed
202 ; The number of columns for --help output.
204 unsigned int help_columns
206 ; Whether this options structure has been through finish_options
208 bool flag_opts_finished
220 Driver Alias(coverage)
226 Common Separate Alias(d)
229 Common Joined Alias(d)
232 Common Separate Alias(dumpbase)
235 Common Separate Alias(dumpdir)
238 Driver Separate Alias(e)
241 Driver Joined Alias(e)
244 Common Warning Alias(Wextra)
247 Driver Separate Alias(Xassembler)
250 Driver JoinedOrMissing Alias(Xassembler)
253 Driver Separate Alias(Xlinker)
256 Driver JoinedOrMissing Alias(Xlinker)
259 Driver Separate Alias(u)
262 Driver Joined Alias(u)
265 Common Driver Var(help_flag)
266 Display this information
269 Common Driver Report Joined
270 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
273 Driver Separate Alias(x)
276 Driver Joined Alias(x)
279 Driver Separate Alias(L)
282 Driver Joined Alias(L)
284 -no-canonical-prefixes
285 Driver Alias(no-canonical-prefixes)
287 -no-standard-libraries
288 Driver Alias(nostdlib)
291 Driver Var(no_sysroot_suffix)
300 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
303 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
306 Driver Alias(pass-exit-codes)
309 Common Alias(Wpedantic)
312 Common Alias(pedantic-errors)
321 Driver Separate Alias(B)
324 Driver JoinedOrMissing Alias(B)
330 Driver Separate Alias(print-file-name=)
333 Driver JoinedOrMissing Alias(print-file-name=)
335 -print-libgcc-file-name
336 Driver Alias(print-libgcc-file-name)
338 -print-multi-directory
339 Driver Alias(print-multi-directory)
342 Driver Alias(print-multi-lib)
344 -print-multi-os-directory
345 Driver Alias(print-multi-os-directory)
348 Driver Alias(print-multiarch)
351 Driver Separate Alias(print-prog-name=)
354 Driver JoinedOrMissing Alias(print-prog-name=)
357 Driver Alias(print-search-dirs)
360 Driver Alias(print-sysroot)
362 -print-sysroot-headers-suffix
363 Driver Alias(print-sysroot-headers-suffix)
369 Driver Alias(save-temps)
375 Driver Separate Alias(specs=)
378 Driver Joined Alias(specs=)
384 Driver Alias(symbolic)
388 Alias for --help=target
396 ;; The driver used to convert options such as --help into forms such
397 ;; as -fhelp; the following four entries are for compatibility with
398 ;; any direct uses of those (undocumented) -f forms
400 Common Driver Alias(-help)
403 Common Driver Joined Alias(-help=)
406 Common Driver Alias(-target-help)
409 Common Driver Alias(-version)
413 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
416 Common Joined Alias(-param)
419 Driver Separate Alias(-sysroot=)
422 Driver JoinedOrMissing
428 Driver Joined Separate
434 Driver Joined Separate
440 Common JoinedOrMissing Optimization
441 -O<number> Set optimization level to <number>
445 Optimize for space rather than speed
449 Optimize for speed disregarding exact standards compliance
453 Optimize for debugging experience rather than speed or size
465 Driver Joined Separate
471 Driver Joined Separate
492 Common RejectNegative Warning Alias(Wextra)
493 This switch is deprecated; use -Wextra instead
496 Driver JoinedOrMissing
499 Driver JoinedOrMissing
502 Driver JoinedOrMissing
505 Common Var(warn_aggregate_return) Warning
506 Warn about returning structures, unions or arrays
508 Waggressive-loop-optimizations
509 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
510 Warn if a loop with constant number of iterations triggers undefined behavior
513 Common Var(warn_array_bounds) Warning
514 Warn if an array is accessed out of bounds
517 Common Var(warn_attributes) Init(1) Warning
518 Warn about inappropriate attribute usage
521 Common Var(warn_cast_align) Warning
522 Warn about pointer casts which increase alignment
525 Common Var(warn_cpp) Init(1) Warning
526 Warn when a #warning directive is encountered
528 Wdeprecated-declarations
529 Common Var(warn_deprecated_decl) Init(1) Warning
530 Warn about uses of __attribute__((deprecated)) declarations
532 Wdisabled-optimization
533 Common Var(warn_disabled_optimization) Warning
534 Warn when an optimization pass is disabled
537 Common Var(warnings_are_errors)
538 Treat all warnings as errors
542 Treat specified warning as error
545 Common Var(extra_warnings) Warning
546 Print extra (possibly unwanted) warnings
549 Common Var(flag_fatal_errors)
550 Exit on the first error occurred
553 Common RejectNegative Joined UInteger
554 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
557 Common Var(warn_free_nonheap_object) Init(1) Warning
558 Warn when attempting to free a non-heap object
561 Common Var(warn_inline) Warning
562 Warn when an inlined function cannot be inlined
564 Winvalid-memory-model
565 Common Var(warn_invalid_memory_model) Init(1) Warning
566 Warn when an atomic memory model parameter is known to be outside the valid range.
569 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
572 Common RejectNegative Joined UInteger Warning
573 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
575 Wunsafe-loop-optimizations
576 Common Var(warn_unsafe_loop_optimizations) Warning
577 Warn if the loop cannot be optimized due to nontrivial assumptions.
580 Common Alias(Wsuggest-attribute=noreturn)
583 Common Var(warn_overflow) Init(1) Warning
584 Warn about overflow in arithmetic expressions
587 Common Var(warn_packed) Warning
588 Warn when the packed attribute has no effect on struct layout
591 Common Var(warn_padded) Warning
592 Warn when padding is required to align structure members
595 Common Var(pedantic) Warning
596 Issue warnings needed for strict compliance to the standard
599 Common Var(warn_shadow) Warning
600 Warn when one local variable shadows another
603 Common Var(warn_stack_protect) Warning
604 Warn when not issuing stack smashing protection for some reason
607 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
608 Warn if stack usage might be larger than specified amount
612 Warn about code which might break strict aliasing rules
615 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
616 Warn about code which might break strict aliasing rules
620 Warn about optimizations that assume that signed overflow is undefined
623 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
624 Warn about optimizations that assume that signed overflow is undefined
626 Wsuggest-attribute=const
627 Common Var(warn_suggest_attribute_const) Warning
628 Warn about functions which might be candidates for __attribute__((const))
630 Wsuggest-attribute=pure
631 Common Var(warn_suggest_attribute_pure) Warning
632 Warn about functions which might be candidates for __attribute__((pure))
634 Wsuggest-attribute=noreturn
635 Common Var(warn_suggest_attribute_noreturn) Warning
636 Warn about functions which might be candidates for __attribute__((noreturn))
639 Common Var(warn_system_headers) Warning
640 Do not suppress warnings from system headers
643 Common Var(warn_trampolines) Warning
644 Warn whenever a trampoline is generated
647 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
648 Warn if a comparison is always true or always false due to the limited range of the data type
651 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
652 Warn about uninitialized automatic variables
655 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
656 Warn about maybe uninitialized automatic variables
660 Does nothing. Preserved for backward compatibility.
663 Common Var(warn_unused) Init(0) Warning
664 Enable all -Wunused- warnings
666 Wunused-but-set-parameter
667 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
668 Warn when a function parameter is only set, otherwise unused
670 Wunused-but-set-variable
671 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
672 Warn when a variable is only set, otherwise unused
675 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
676 Warn when a function is unused
679 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
680 Warn when a label is unused
683 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
684 Warn when a function parameter is unused
687 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
688 Warn when an expression value is unused
691 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
692 Warn when a variable is unused
695 Common Var(warn_coverage_mismatch) Init(1) Warning
696 Warn in case profiles in -fprofile-use do not match
698 Wvector-operation-performance
699 Common Var(warn_vector_operation_performance) Warning
700 Warn when a vector operation is compiled outside the SIMD
715 Common Separate Var(aux_info_file_name)
716 -aux-info <file> Emit declaration information into <file>
719 Common Joined Alias(aux-info)
722 Common Separate RejectDriver Var(aux_base_name)
725 Common Separate RejectDriver
735 -d<letters> Enable dumps from specific passes of the compiler
738 Common Separate Var(dump_base_name)
739 -dumpbase <file> Set the file basename to be used for dumps
742 Common Separate Var(dump_dir_name)
743 -dumpdir <dir> Set the directory name to be used for dumps
755 Driver Joined Separate
757 ; This option has historically been passed down to the linker by an
758 ; accident of a %{e*} spec, so ensure it continues to be passed down
759 ; as a single option. The supported option for this purpose is
760 ; -rdynamic. See PR 47390.
764 ; The version of the C++ ABI in use. The following values are allowed:
766 ; 0: The version of the ABI believed most conformant with the C++ ABI
767 ; specification. This ABI may change as bugs are discovered and fixed.
768 ; Therefore, 0 will not necessarily indicate the same ABI in different
771 ; 1: The version of the ABI first used in G++ 3.2.
773 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
775 ; 3: The version of the ABI that fixes the missing underscore
776 ; in template non-type arguments of pointer type.
778 ; 4: The version of the ABI that introduces unambiguous mangling of
779 ; vector types. First selectable in G++ 4.5.
781 ; 5: The version of the ABI that ignores attribute const/noreturn
782 ; in function pointer mangling, and corrects mangling of decltype and
783 ; function parameters used in other parameters and the return type.
784 ; First selectable in G++ 4.6.
786 ; 6: The version of the ABI that doesn't promote scoped enums to int and
787 ; changes the mangling of template argument packs, const/static_cast,
788 ; prefix ++ and --, and a class scope function used as a template
790 ; First selectable in G++ 4.7.
792 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
793 ; corrects the mangling of lambdas in default argument scope.
794 ; First selectable in G++ 4.8.
796 ; 8: The version of the ABI that corrects the substitution behavior of
797 ; function types with function-cv-qualifiers.
798 ; First selectable in G++ 4.9.
800 ; Additional positive integers will be assigned as new versions of
801 ; the ABI become the default version of the ABI.
803 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
805 faggressive-loop-optimizations
806 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
807 Aggressively optimize loops using language constraints
810 Common Report Var(align_functions,0) Optimization UInteger
811 Align the start of functions
814 Common RejectNegative Joined UInteger Var(align_functions)
817 Common Report Var(align_jumps,0) Optimization UInteger
818 Align labels which are only reached by jumping
821 Common RejectNegative Joined UInteger Var(align_jumps)
824 Common Report Var(align_labels,0) Optimization UInteger
828 Common RejectNegative Joined UInteger Var(align_labels)
831 Common Report Var(align_loops,0) Optimization UInteger
832 Align the start of loops
835 Common RejectNegative Joined UInteger Var(align_loops)
839 Does nothing. Preserved for backward compatibility.
843 Does nothing. Preserved for backward compatibility.
845 fargument-noalias-global
847 Does nothing. Preserved for backward compatibility.
849 fargument-noalias-anything
851 Does nothing. Preserved for backward compatibility.
854 Common Report Var(flag_asan)
855 Enable AddressSanitizer, a memory error detector
858 Common Report Var(flag_tsan)
859 Enable ThreadSanitizer, a data race detector
861 fasynchronous-unwind-tables
862 Common Report Var(flag_asynchronous_unwind_tables) Optimization
863 Generate unwind tables that are exact at each instruction boundary
866 Common Report Var(flag_auto_inc_dec) Init(1)
867 Generate auto-inc/dec instructions
869 ; -fcheck-bounds causes gcc to generate array bounds checks.
870 ; For C, C++ and ObjC: defaults off.
871 ; For Java: defaults to on.
872 ; For Fortran: defaults to off.
874 Common Report Var(flag_bounds_check)
875 Generate code to check bounds before indexing arrays
878 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
879 Replace add, compare, branch with branch on count register
881 fbranch-probabilities
882 Common Report Var(flag_branch_probabilities) Optimization
883 Use profiling information for branch probabilities
885 fbranch-target-load-optimize
886 Common Report Var(flag_branch_target_load_optimize) Optimization
887 Perform branch target load optimization before prologue / epilogue threading
889 fbranch-target-load-optimize2
890 Common Report Var(flag_branch_target_load_optimize2) Optimization
891 Perform branch target load optimization after prologue / epilogue threading
894 Common Report Var(flag_btr_bb_exclusive) Optimization
895 Restrict target load migration not to re-use registers in any basic block
898 Common Joined RejectNegative Var(common_deferred_options) Defer
899 -fcall-saved-<register> Mark <register> as being preserved across functions
902 Common Joined RejectNegative Var(common_deferred_options) Defer
903 -fcall-used-<register> Mark <register> as being corrupted by function calls
905 ; Nonzero for -fcaller-saves: allocate values in regs that need to
906 ; be saved across function calls, if that produces overall better code.
907 ; Optional now, so people can test it.
909 Common Report Var(flag_caller_saves) Optimization
910 Save registers around function calls
913 Common Report Var(flag_check_data_deps)
914 Compare the results of several data dependence analyzers.
916 fcombine-stack-adjustments
917 Common Report Var(flag_combine_stack_adjustments) Optimization
918 Looks for opportunities to reduce stack adjustments and stack references.
921 Common Report Var(flag_no_common,0) Optimization
922 Do not put uninitialized globals in the common section
926 ; Converted by the driver to -fcompare-debug= options.
929 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
930 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
932 fcompare-debug-second
933 Common Driver RejectNegative Var(flag_compare_debug)
934 Run only the second compilation of -fcompare-debug
937 Common Report Var(flag_compare_elim_after_reload) Optimization
938 Perform comparison elimination after register allocation has finished
941 Common Var(flag_conserve_stack) Optimization
942 Do not perform optimizations increasing noticeably stack usage
945 Common Report Var(flag_cprop_registers) Optimization
946 Perform a register copy-propagation optimization pass
949 Common Report Var(flag_crossjumping) Optimization
950 Perform cross-jumping optimization
953 Common Report Var(flag_cse_follow_jumps) Optimization
954 When running CSE, follow jumps to their targets
958 Does nothing. Preserved for backward compatibility.
961 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
962 Omit range reduction step when performing complex division
965 Common Report Var(flag_cx_fortran_rules) Optimization
966 Complex multiplication and division follow Fortran rules
969 Common Report Var(flag_data_sections) Optimization
970 Place data items into their own section
973 Common Report Var(common_deferred_options) Defer
974 List all available debugging counters with their limits and counts.
977 Common RejectNegative Joined Var(common_deferred_options) Defer
978 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
981 Common Joined RejectNegative Var(common_deferred_options) Defer
982 Map one directory name to another in debug information
985 Common Report Var(flag_debug_types_section) Init(0)
986 Output .debug_types section when using DWARF v4 debuginfo.
988 ; Nonzero for -fdefer-pop: don't pop args after each function call
989 ; instead save them up to pop many calls' args with one insns.
991 Common Report Var(flag_defer_pop) Optimization
992 Defer popping functions args from stack until later
995 Common Report Var(flag_delayed_branch) Optimization
996 Attempt to fill delay slots of branch instructions
998 fdelete-dead-exceptions
999 Common Report Var(flag_delete_dead_exceptions) Init(0)
1000 Delete dead instructions that may throw exceptions
1002 fdelete-null-pointer-checks
1003 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
1004 Delete useless null pointer checks
1007 Common Report Var(flag_devirtualize) Optimization
1008 Try to convert virtual calls to direct ones.
1010 fdiagnostics-show-location=
1011 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1012 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1014 ; Required for these enum values.
1019 Name(diagnostic_prefixing_rule) Type(int)
1022 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1025 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1027 fdiagnostics-show-caret
1028 Common Var(flag_diagnostics_show_caret) Init(1)
1029 Show the source line with a caret indicating the column
1032 Common Alias(fdiagnostics-color=,always,never)
1036 Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1037 -fdiagnostics-color=[never|always|auto] Colorize diagnostics
1039 ; Required for these enum values.
1044 Name(diagnostic_color_rule) Type(int)
1047 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1050 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1053 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1055 fdiagnostics-show-option
1056 Common Var(flag_diagnostics_show_option) Init(1)
1057 Amend appropriate diagnostic messages with the command line option that controls them
1060 Common Joined RejectNegative Var(common_deferred_options) Defer
1061 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1064 Common Joined RejectNegative Var(common_deferred_options) Defer
1065 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1068 Common Joined RejectNegative Var(common_deferred_options) Defer
1069 -fdump-<type> Dump various compiler internals to a file
1072 Driver RejectNegative
1075 Common RejectNegative Joined Var(flag_dump_final_insns)
1076 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1079 Common RejectNegative Joined Var(flag_dump_go_spec)
1080 -fdump-go-spec=filename Write all declarations to file as Go code
1083 Common Report Var(flag_dump_noaddr)
1084 Suppress output of addresses in debugging dumps
1087 Common Var(flag_dump_passes) Init(0)
1088 Dump optimization passes
1091 Common Report Var(flag_dump_unnumbered)
1092 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1094 fdump-unnumbered-links
1095 Common Report Var(flag_dump_unnumbered_links)
1096 Suppress output of previous and next insn numbers in debugging dumps
1099 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1100 Enable CFI tables via GAS assembler directives.
1103 Common Report Var(flag_early_inlining) Init(1) Optimization
1104 Perform early inlining
1106 feliminate-dwarf2-dups
1107 Common Report Var(flag_eliminate_dwarf2_dups)
1108 Perform DWARF2 duplicate elimination
1111 Common Report Var(flag_ipa_sra) Init(0) Optimization
1112 Perform interprocedural reduction of aggregates
1114 feliminate-unused-debug-symbols
1115 Common Report Var(flag_debug_only_used_symbols)
1116 Perform unused type elimination in debug info
1118 feliminate-unused-debug-types
1119 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1120 Perform unused type elimination in debug info
1122 femit-class-debug-always
1123 Common Report Var(flag_emit_class_debug_always) Init(0)
1124 Do not suppress C++ class debug information.
1127 Common Report Var(flag_exceptions) Optimization
1128 Enable exception handling
1130 fexpensive-optimizations
1131 Common Report Var(flag_expensive_optimizations) Optimization
1132 Perform a number of minor, expensive optimizations
1135 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1136 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1139 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1142 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1145 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1151 Common Var(flag_fat_lto_objects) Init(1)
1152 Output lto objects containing both the intermediate language and binary output.
1155 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1156 Assume no NaNs or infinities are generated
1159 Common Joined RejectNegative Var(common_deferred_options) Defer
1160 -ffixed-<register> Mark <register> as being unavailable to the compiler
1163 Common Report Var(flag_float_store) Optimization
1164 Don't allocate floats and doubles in extended-precision registers
1168 Does nothing. Preserved for backward compatibility.
1171 Common Report Var(flag_forward_propagate) Optimization
1172 Perform a forward propagation pass on RTL
1175 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1176 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1179 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1182 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1184 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1186 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1189 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1191 ; Nonzero means don't put addresses of constant functions in registers.
1192 ; Used for compiling the Unix kernel, where strange substitutions are
1193 ; done on the assembly output.
1195 Common Report Var(flag_no_function_cse,0)
1196 Allow function addresses to be held in registers
1199 Common Report Var(flag_function_sections)
1200 Place each function into its own section
1203 Common Report Var(flag_gcse) Optimization
1204 Perform global common subexpression elimination
1207 Common Report Var(flag_gcse_lm) Init(1) Optimization
1208 Perform enhanced load motion during global common subexpression elimination
1211 Common Report Var(flag_gcse_sm) Init(0) Optimization
1212 Perform store motion after global common subexpression elimination
1215 Common Report Var(flag_gcse_las) Init(0) Optimization
1216 Perform redundant load after store elimination in global common subexpression
1220 Common Report Var(flag_gcse_after_reload) Optimization
1221 Perform global common subexpression elimination after register allocation
1224 ; This option is not documented yet as its semantics will change.
1226 Common Report Var(flag_graphite)
1227 Enable in and out of Graphite representation
1230 Common Report Var(flag_graphite_identity) Optimization
1231 Enable Graphite Identity transformation
1233 fhoist-adjacent-loads
1234 Common Report Var(flag_hoist_adjacent_loads) Optimization
1235 Enable hoisting adjacent loads to encourage generating conditional move
1238 floop-parallelize-all
1239 Common Report Var(flag_loop_parallelize_all) Optimization
1240 Mark all loops as parallel
1243 Common Report Var(flag_loop_strip_mine) Optimization
1244 Enable Loop Strip Mining transformation
1247 Common Report Var(flag_loop_interchange) Optimization
1248 Enable Loop Interchange transformation
1251 Common Report Var(flag_loop_block) Optimization
1252 Enable Loop Blocking transformation
1255 Common Report Var(flag_tm)
1256 Enable support for GNU transactional memory
1260 Does nothing. Preserved for backward compatibility.
1263 Common Report Var(flag_loop_optimize_isl) Optimization
1264 Enable the ISL based loop nest optimizer
1266 fstrict-volatile-bitfields
1267 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1268 Force bitfield accesses to match their type width
1270 fguess-branch-probability
1271 Common Report Var(flag_guess_branch_prob) Optimization
1272 Enable guessing of branch probabilities
1274 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1275 ; Generate position-independent code for executables if possible
1276 ; On SVR4 targets, it also controls whether or not to emit a
1277 ; string identifying the compiler.
1279 Common Report Var(flag_no_ident,0)
1280 Process #ident directives
1283 Common Report Var(flag_if_conversion) Optimization
1284 Perform conversion of conditional jumps to branchless equivalents
1287 Common Report Var(flag_if_conversion2) Optimization
1288 Perform conversion of conditional jumps to conditional execution
1291 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1292 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1295 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1298 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1301 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1304 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1306 ftree-loop-if-convert
1307 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1308 Convert conditional jumps in innermost loops to branchless equivalents
1310 ftree-loop-if-convert-stores
1311 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1312 Also if-convert conditional jumps containing memory writes
1314 ; -finhibit-size-directive inhibits output of .size for ELF.
1315 ; This is used only for compiling crtstuff.c,
1316 ; and it may be extended to other effects
1317 ; needed for crtstuff.c on other systems.
1318 finhibit-size-directive
1319 Common Report Var(flag_inhibit_size_directive)
1320 Do not generate .size directives
1323 Common Report Var(flag_indirect_inlining)
1324 Perform indirect inlining
1326 ; General flag to enable inlining. Specifying -fno-inline will disable
1327 ; all inlining apart from always-inline functions.
1329 Common Report Var(flag_no_inline,0) Init(0) Optimization
1330 Enable inlining of function declared \"inline\", disabling disables all inlining
1332 finline-small-functions
1333 Common Report Var(flag_inline_small_functions) Optimization
1334 Integrate functions into their callers when code size is known not to grow
1337 Common Report Var(flag_inline_functions) Optimization
1338 Integrate functions not declared \"inline\" into their callers when profitable
1340 finline-functions-called-once
1341 Common Report Var(flag_inline_functions_called_once) Optimization
1342 Integrate functions only required by their single caller
1345 Common RejectNegative Joined Alias(finline-limit=)
1348 Common RejectNegative Joined UInteger
1349 -finline-limit=<number> Limit the size of inlined functions to <number>
1352 Common Report Var(flag_inline_atomics) Init(1) Optimization
1353 Inline __atomic operations when a lock free instruction sequence is available.
1355 finstrument-functions
1356 Common Report Var(flag_instrument_function_entry_exit)
1357 Instrument function entry and exit with profiling calls
1359 finstrument-functions-exclude-function-list=
1360 Common RejectNegative Joined
1361 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1363 finstrument-functions-exclude-file-list=
1364 Common RejectNegative Joined
1365 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1368 Common Report Var(flag_ipa_cp) Optimization
1369 Perform Interprocedural constant propagation
1372 Common Report Var(flag_ipa_cp_clone) Optimization
1373 Perform cloning to make Interprocedural constant propagation stronger
1376 Common Report Var(flag_ipa_profile) Init(0) Optimization
1377 Perform interprocedural profile propagation
1380 Common Report Var(flag_ipa_pta) Init(0) Optimization
1381 Perform interprocedural points-to analysis
1384 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1385 Discover pure and const functions
1388 Common Report Var(flag_ipa_reference) Init(0) Optimization
1389 Discover readonly and non addressable static variables
1393 Does nothing. Preserved for backward compatibility.
1397 Does nothing. Preserved for backward compatibility.
1400 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1401 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1404 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1407 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1410 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1413 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1414 -fira-region=[one|all|mixed] Set regions for IRA
1417 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1420 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1423 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1426 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1429 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1430 Use IRA based register pressure calculation
1431 in RTL hoist optimizations.
1434 Common Report Var(flag_ira_loop_pressure)
1435 Use IRA based register pressure calculation
1436 in RTL loop optimizations.
1438 fira-share-save-slots
1439 Common Report Var(flag_ira_share_save_slots) Init(1)
1440 Share slots for saving different hard registers.
1442 fira-share-spill-slots
1443 Common Report Var(flag_ira_share_spill_slots) Init(1)
1444 Share stack slots for spilled pseudo-registers.
1447 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1448 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1451 Common Report Var(flag_ivopts) Init(1) Optimization
1452 Optimize induction variables on trees
1455 Common Var(flag_jump_tables) Init(1) Optimization
1456 Use jump tables for sufficiently large switch statements
1458 fkeep-inline-functions
1459 Common Report Var(flag_keep_inline_functions)
1460 Generate code for functions even if they are fully inlined
1463 Common Report Var(flag_keep_static_consts) Init(1)
1464 Emit static const variables even if they are not used
1467 Common Report Var(flag_leading_underscore) Init(-1)
1468 Give external symbols a leading underscore
1472 Does nothing. Preserved for backward compatibility.
1476 Enable link-time optimization.
1479 Common RejectNegative Joined Var(flag_lto)
1480 Link-time optimization with number of parallel jobs or jobserver.
1483 Common Var(flag_lto_partition_1to1)
1484 Partition symbols and vars at linktime based on object files they originate from
1486 flto-partition=balanced
1487 Common Var(flag_lto_partition_balanced)
1488 Partition functions and vars at linktime into approximately same sized buckets
1491 Common Var(flag_lto_partition_max)
1492 Put every symbol into separate partition
1495 Common Var(flag_lto_partition_none)
1496 Disable partioning and streaming
1498 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1499 flto-compression-level=
1500 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1501 -flto-compression-level=<number> Use zlib compression level <number> for IL
1504 Common Report Var(flag_lto_report) Init(0)
1505 Report various link-time optimization statistics
1508 Common Report Var(flag_lto_report_wpa) Init(0)
1509 Report various link-time optimization statistics for WPA only
1512 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1513 Set errno after built-in math functions
1516 Common Joined RejectNegative UInteger Var(flag_max_errors)
1517 -fmax-errors=<number> Maximum number of errors to report
1520 Common Report Var(mem_report)
1521 Report on permanent memory allocation
1524 Common Report Var(mem_report_wpa)
1525 Report on permanent memory allocation in WPA only
1527 ; This will attempt to merge constant section constants, if 1 only
1528 ; string constants and constants from constant pool, if 2 also constant
1530 fmerge-all-constants
1531 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1532 Attempt to merge identical constants and constant variables
1535 Common Report Var(flag_merge_constants,1) Optimization
1536 Attempt to merge identical constants across compilation units
1538 fmerge-debug-strings
1539 Common Report Var(flag_merge_debug_strings) Init(1)
1540 Attempt to merge identical debug strings across compilation units
1543 Common RejectNegative Joined UInteger
1544 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1547 Common Report Var(flag_modulo_sched) Optimization
1548 Perform SMS based modulo scheduling before the first scheduling pass
1550 fmodulo-sched-allow-regmoves
1551 Common Report Var(flag_modulo_sched_allow_regmoves)
1552 Perform SMS based modulo scheduling with register moves allowed
1554 fmove-loop-invariants
1555 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1556 Move loop invariant computations out of loops
1559 Common Var(flag_dce) Init(1) Optimization
1560 Use the RTL dead code elimination pass
1563 Common Var(flag_dse) Init(1) Optimization
1564 Use the RTL dead store elimination pass
1566 freschedule-modulo-scheduled-loops
1567 Common Report Var(flag_resched_modulo_sched) Optimization
1568 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1570 fnon-call-exceptions
1571 Common Report Var(flag_non_call_exceptions) Optimization
1572 Support synchronous non-call exceptions
1575 Common Report Var(flag_omit_frame_pointer) Optimization
1576 When possible do not generate stack frames
1579 Common Report Var(flag_opt_info) Optimization
1580 Enable all optimization info dumps on stderr
1583 Common Joined RejectNegative Var(common_deferred_options) Defer
1584 -fopt-info[-<type>=filename] Dump compiler optimization details
1586 foptimize-register-move
1587 Common Report Var(flag_regmove) Optimization
1588 Do the full register move optimization pass
1590 foptimize-sibling-calls
1591 Common Report Var(flag_optimize_sibling_calls) Optimization
1592 Optimize sibling and tail recursive calls
1595 Common Report Var(flag_partial_inlining)
1596 Perform partial inlining
1599 Common Report Var(pre_ipa_mem_report)
1600 Report on memory allocation before interprocedural optimization
1602 fpost-ipa-mem-report
1603 Common Report Var(post_ipa_mem_report)
1604 Report on memory allocation before interprocedural optimization
1607 Common Report Var(flag_pack_struct) Optimization
1608 Pack structure members together without holes
1611 Common RejectNegative Joined UInteger Optimization
1612 -fpack-struct=<number> Set initial maximum structure member alignment
1615 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1616 Return small aggregates in memory, not registers
1619 Common Report Var(flag_peel_loops) Optimization
1620 Perform loop peeling
1623 Common Report Var(flag_no_peephole,0) Optimization
1624 Enable machine specific peephole optimizations
1627 Common Report Var(flag_peephole2) Optimization
1628 Enable an RTL peephole pass before sched2
1631 Common Report Var(flag_pic,2) Negative(fPIE)
1632 Generate position-independent code if possible (large mode)
1635 Common Report Var(flag_pie,2) Negative(fpic)
1636 Generate position-independent code for executables if possible (large mode)
1639 Common Report Var(flag_pic,1) Negative(fpie)
1640 Generate position-independent code if possible (small mode)
1643 Common Report Var(flag_pie,1) Negative(fPIC)
1644 Generate position-independent code for executables if possible (small mode)
1647 Common Joined RejectNegative Var(common_deferred_options) Defer
1648 Specify a plugin to load
1651 Common Joined RejectNegative Var(common_deferred_options) Defer
1652 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1654 fpredictive-commoning
1655 Common Report Var(flag_predictive_commoning) Optimization
1656 Run predictive commoning optimization.
1658 fprefetch-loop-arrays
1659 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1660 Generate prefetch instructions, if available, for arrays in loops
1663 Common Report Var(profile_flag)
1664 Enable basic program profiling code
1667 Common Report Var(profile_arc_flag)
1668 Insert arc-based program profiling code
1671 Common Joined RejectNegative Var(profile_data_prefix)
1672 Set the top-level directory for storing the profile data.
1673 The default is 'pwd'.
1676 Common Report Var(flag_profile_correction)
1677 Enable correction of flow inconsistent profile data input
1681 Enable common options for generating profile info for profile feedback directed optimizations
1684 Common Joined RejectNegative
1685 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1688 Common Var(flag_profile_use)
1689 Enable common options for performing profile feedback directed optimizations
1692 Common Joined RejectNegative
1693 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1696 Common Report Var(flag_profile_values)
1697 Insert code to profile values of expressions
1700 Common Report Var(profile_report)
1701 Report on consistency of profile
1704 Common Var(common_deferred_options) Defer
1707 Common Joined RejectNegative Var(common_deferred_options) Defer
1708 -frandom-seed=<string> Make compile reproducible using <string>
1710 ; This switch causes the command line that was used to create an
1711 ; object file to be recorded into the object file. The exact format
1712 ; of this recording is target and binary file format dependent.
1713 ; It is related to the -fverbose-asm switch, but that switch only
1714 ; records information in the assembler output file as comments, so
1715 ; they never reach the object file.
1716 frecord-gcc-switches
1717 Common Report Var(flag_record_gcc_switches)
1718 Record gcc command line switches in the object file.
1721 Common Report Var(flag_pcc_struct_return,0) Optimization
1722 Return small aggregates in registers
1725 Common Report Var(flag_regmove) Optimization
1726 Enables a register move optimization
1729 Common Report Var(flag_rename_registers) Init(2) Optimization
1730 Perform a register renaming optimization pass
1733 Common Report Var(flag_reorder_blocks) Optimization
1734 Reorder basic blocks to improve code placement
1736 freorder-blocks-and-partition
1737 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1738 Reorder basic blocks and partition into hot and cold sections
1741 Common Report Var(flag_reorder_functions) Optimization
1742 Reorder functions to improve code placement
1744 frerun-cse-after-loop
1745 Common Report Var(flag_rerun_cse_after_loop) Optimization
1746 Add a common subexpression elimination pass after loop optimizations
1750 Does nothing. Preserved for backward compatibility.
1753 Common Report Var(flag_rounding_math) Optimization SetByCombined
1754 Disable optimizations that assume default FP rounding behavior
1757 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1758 Enable scheduling across basic blocks
1761 Common Report Var(flag_sched_pressure) Init(0) Optimization
1762 Enable register pressure sensitive insn scheduling
1765 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1766 Allow speculative motion of non-loads
1769 Common Report Var(flag_schedule_speculative_load) Optimization
1770 Allow speculative motion of some loads
1772 fsched-spec-load-dangerous
1773 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1774 Allow speculative motion of more loads
1777 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1778 -fsched-verbose=<number> Set the verbosity level of the scheduler
1780 fsched2-use-superblocks
1781 Common Report Var(flag_sched2_use_superblocks) Optimization
1782 If scheduling post reload, do superblock scheduling
1786 Does nothing. Preserved for backward compatibility.
1789 Common Report Var(flag_schedule_insns) Optimization
1790 Reschedule instructions before register allocation
1793 Common Report Var(flag_schedule_insns_after_reload) Optimization
1794 Reschedule instructions after register allocation
1796 ; This flag should be on when a target implements non-trivial
1797 ; scheduling hooks, maybe saving some information for its own sake.
1798 ; On IA64, for example, this is used for correct bundling.
1799 fselective-scheduling
1800 Common Report Var(flag_selective_scheduling) Optimization
1801 Schedule instructions using selective scheduling algorithm
1803 fselective-scheduling2
1804 Common Report Var(flag_selective_scheduling2) Optimization
1805 Run selective scheduling after reload
1807 fsel-sched-pipelining
1808 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1809 Perform software pipelining of inner loops during selective scheduling
1811 fsel-sched-pipelining-outer-loops
1812 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1813 Perform software pipelining of outer loops during selective scheduling
1815 fsel-sched-reschedule-pipelined
1816 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1817 Reschedule pipelined regions without pipelining
1819 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1820 ; of stalled insns into the ready list.
1821 fsched-stalled-insns
1822 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1823 Allow premature scheduling of queued insns
1825 fsched-stalled-insns=
1826 Common RejectNegative Joined UInteger
1827 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1829 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1830 ; be examined for a dependency on a stalled insn that is candidate for
1831 ; premature removal from the queue of stalled insns into the ready list (has
1832 ; an effect only if the flag 'sched_stalled_insns' is set).
1833 fsched-stalled-insns-dep
1834 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1835 Set dependence distance checking in premature scheduling of queued insns
1837 fsched-stalled-insns-dep=
1838 Common RejectNegative Joined UInteger
1839 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1841 fsched-group-heuristic
1842 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1843 Enable the group heuristic in the scheduler
1845 fsched-critical-path-heuristic
1846 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1847 Enable the critical path heuristic in the scheduler
1849 fsched-spec-insn-heuristic
1850 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1851 Enable the speculative instruction heuristic in the scheduler
1853 fsched-rank-heuristic
1854 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1855 Enable the rank heuristic in the scheduler
1857 fsched-last-insn-heuristic
1858 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1859 Enable the last instruction heuristic in the scheduler
1861 fsched-dep-count-heuristic
1862 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1863 Enable the dependent count heuristic in the scheduler
1866 Common Report Var(flag_section_anchors) Optimization
1867 Access data in the same section from shared anchor points
1871 Does nothing. Preserved for backward compatibility.
1875 Does nothing. Preserved for backward compatibility.
1878 Common Report Var(flag_ree) Init(0)
1879 Turn on Redundant Extensions Elimination pass.
1882 Common Report Var(flag_show_column) Init(1)
1883 Show column numbers in diagnostics, when available. Default on
1886 Common Report Var(flag_shrink_wrap) Optimization
1887 Emit function prologues only before parts of the function that need it,
1888 rather than at the top of the function.
1891 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1892 Disable optimizations observable by IEEE signaling NaNs
1895 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1896 Disable floating point optimizations that ignore the IEEE signedness of zero
1898 fsingle-precision-constant
1899 Common Report Var(flag_single_precision_constant) Optimization
1900 Convert floating point constants to single precision constants
1902 fsplit-ivs-in-unroller
1903 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1904 Split lifetimes of induction variables when loops are unrolled
1907 Common Report Var(flag_split_stack) Init(-1)
1908 Generate discontiguous stack frames
1911 Common Report Var(flag_split_wide_types) Optimization
1912 Split wide types into independent registers
1914 fvariable-expansion-in-unroller
1915 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1916 Apply variable expansion when loops are unrolled
1919 Common Report RejectNegative Joined
1920 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1923 Common Alias(fstack-check=, specific, no)
1924 Insert stack checking code into the program. Same as -fstack-check=specific
1927 Common Var(common_deferred_options) Defer
1929 fstack-limit-register=
1930 Common RejectNegative Joined Var(common_deferred_options) Defer
1931 -fstack-limit-register=<register> Trap if the stack goes past <register>
1933 fstack-limit-symbol=
1934 Common RejectNegative Joined Var(common_deferred_options) Defer
1935 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1938 Common Report Var(flag_stack_protect, 1)
1939 Use propolice as a stack protection method
1941 fstack-protector-all
1942 Common Report RejectNegative Var(flag_stack_protect, 2)
1943 Use a stack protection method for every function
1945 fstack-protector-strong
1946 Common Report RejectNegative Var(flag_stack_protect, 3)
1947 Use a smart stack protection method for certain functions
1950 Common RejectNegative Var(flag_stack_usage)
1951 Output stack usage information on a per-function basis
1955 Does nothing. Preserved for backward compatibility.
1957 ; Nonzero if we should do (language-dependent) alias analysis.
1958 ; Typically, this analysis will assume that expressions of certain
1959 ; types do not alias expressions of certain other types. Only used
1960 ; if alias analysis (in general) is enabled.
1962 Common Report Var(flag_strict_aliasing) Optimization
1963 Assume strict aliasing rules apply
1966 Common Report Var(flag_strict_overflow)
1967 Treat signed overflow as undefined
1970 Common Report Var(flag_sync_libcalls) Init(1)
1971 Implement __atomic operations via libcalls to legacy __sync functions
1974 Common Report Var(flag_syntax_only)
1975 Check for syntax errors, then stop
1978 Common Report Var(flag_test_coverage)
1979 Create data files needed by \"gcov\"
1982 Common Report Var(flag_thread_jumps) Optimization
1983 Perform jump threading optimizations
1986 Common Report Var(time_report)
1987 Report the time taken by each compiler pass
1990 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1991 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1994 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1997 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2000 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2003 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2006 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2009 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2010 Reorder top level functions, variables, and asms
2013 Common Report Var(flag_tracer)
2014 Perform superblock formation via tail duplication
2016 ; Zero means that floating-point math operations cannot generate a
2017 ; (user-visible) trap. This is the case, for example, in nonstop
2018 ; IEEE 754 arithmetic.
2020 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2021 Assume floating-point operations can trap
2024 Common Report Var(flag_trapv) Optimization
2025 Trap for signed overflow in addition, subtraction and multiplication
2028 Common Report Var(flag_tree_ccp) Optimization
2029 Enable SSA-CCP optimization on trees
2032 Common Report Var(flag_tree_bit_ccp) Optimization
2033 Enable SSA-BIT-CCP optimization on trees
2037 Does nothing. Preserved for backward compatibility.
2040 Common Report Var(flag_tree_ch) Optimization
2041 Enable loop header copying on trees
2043 ftree-coalesce-inlined-vars
2044 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2045 Enable coalescing of copy-related user variables that are inlined
2048 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2049 Enable coalescing of all copy-related user variables
2052 Common Report Var(flag_tree_copyrename) Optimization
2053 Replace SSA temporaries with better names in copies
2056 Common Report Var(flag_tree_copy_prop) Optimization
2057 Enable copy propagation on trees
2059 ftree-store-copy-prop
2061 Does nothing. Preserved for backward compatibility.
2064 Common Report Var(flag_tree_cselim) Init(2) Optimization
2065 Transform condition stores into unconditional ones
2067 ftree-switch-conversion
2068 Common Report Var(flag_tree_switch_conversion) Optimization
2069 Perform conversions of switch initializations.
2072 Common Report Var(flag_tree_dce) Optimization
2073 Enable SSA dead code elimination optimization on trees
2075 ftree-dominator-opts
2076 Common Report Var(flag_tree_dom) Optimization
2077 Enable dominator optimizations
2080 Common Report Var(flag_tree_tail_merge) Optimization
2081 Enable tail merging on trees
2084 Common Report Var(flag_tree_dse) Optimization
2085 Enable dead store elimination
2088 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2089 Enable forward propagation on trees
2092 Common Report Var(flag_tree_fre) Optimization
2093 Enable Full Redundancy Elimination (FRE) on trees
2096 Common Report Var(flag_optimize_strlen) Optimization
2097 Enable string length optimizations on trees
2099 ftree-loop-distribution
2100 Common Report Var(flag_tree_loop_distribution) Optimization
2101 Enable loop distribution on trees
2103 ftree-loop-distribute-patterns
2104 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2105 Enable loop distribution for patterns transformed into a library call
2108 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2109 Enable loop invariant motion on trees
2112 Common Alias(floop-interchange)
2113 Enable loop interchange transforms. Same as -floop-interchange
2116 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2117 Create canonical induction variables in loops
2120 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2121 Enable loop optimizations on tree level
2123 ftree-parallelize-loops=
2124 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2125 Enable automatic parallelization of loops
2128 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2129 Enable hoisting loads from conditional pointers.
2132 Common Report Var(flag_tree_pre) Optimization
2133 Enable SSA-PRE optimization on trees
2136 Common Report Var(flag_tree_partial_pre) Optimization
2137 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2140 Common Report Var(flag_tree_pta) Init(1) Optimization
2141 Perform function-local points-to analysis on trees.
2144 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2145 Enable reassociation on tree level
2149 Does nothing. Preserved for backward compatibility.
2152 Common Report Var(flag_tree_sink) Optimization
2153 Enable SSA code sinking on trees
2156 Common Report Var(flag_tree_slsr) Optimization
2157 Perform straight-line strength reduction
2160 Common Report Var(flag_tree_sra) Optimization
2161 Perform scalar replacement of aggregates
2164 Common Report Var(flag_tree_ter) Optimization
2165 Replace temporary expressions in the SSA->normal pass
2168 Common Report Var(flag_tree_live_range_split) Optimization
2169 Perform live range splitting during the SSA->normal pass
2172 Common Report Var(flag_tree_vrp) Init(0) Optimization
2173 Perform Value Range Propagation on trees
2176 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2177 Compile whole compilation unit at a time
2180 Common Report Var(flag_unroll_loops) Optimization
2181 Perform loop unrolling when iteration count is known
2184 Common Report Var(flag_unroll_all_loops) Optimization
2185 Perform loop unrolling for all loops
2187 ; Nonzero means that loop optimizer may assume that the induction variables
2188 ; that control loops do not overflow and that the loops with nontrivial
2189 ; exit condition are not infinite
2190 funsafe-loop-optimizations
2191 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2192 Allow loop optimizations to assume that the loops behave in normal way
2195 Common Report Var(flag_associative_math) SetByCombined
2196 Allow optimization for floating-point arithmetic which may change the
2197 result of the operation due to rounding.
2200 Common Report Var(flag_reciprocal_math) SetByCombined
2201 Same as -fassociative-math for expressions which include division.
2203 ; Nonzero means that unsafe floating-point math optimizations are allowed
2204 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2205 ; are allowed to assume that their arguments and results are "normal"
2206 ; (e.g., nonnegative for SQRT).
2207 funsafe-math-optimizations
2208 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2209 Allow math optimizations that may violate IEEE or ISO standards
2212 Common Report Var(flag_unswitch_loops) Optimization
2213 Perform loop unswitching
2216 Common Report Var(flag_unwind_tables) Optimization
2217 Just generate unwind tables for exception handling
2220 Common Negative(fuse-ld=gold)
2221 Use the bfd linker instead of the default linker
2224 Common Negative(fuse-ld=bfd)
2225 Use the gold linker instead of the default linker
2230 ; Positive if we should track variables, negative if we should run
2231 ; the var-tracking pass only to discard debug annotations, zero if
2232 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2233 ; will be set according to optimize, debug_info_level and debug_hooks
2234 ; in process_options ().
2236 Common Report Var(flag_var_tracking) Init(2) Optimization
2237 Perform variable tracking
2239 ; Positive if we should track variables at assignments, negative if
2240 ; we should run the var-tracking pass only to discard debug
2241 ; annotations. When flag_var_tracking_assignments ==
2242 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2243 fvar-tracking-assignments
2244 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2245 Perform variable tracking by annotating assignments
2247 ; Nonzero if we should toggle flag_var_tracking_assignments after
2248 ; processing options and computing its default. */
2249 fvar-tracking-assignments-toggle
2250 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2251 Toggle -fvar-tracking-assignments
2253 ; Positive if we should track uninitialized variables, negative if
2254 ; we should run the var-tracking pass only to discard debug
2255 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2256 ; will be set according to flag_var_tracking.
2257 fvar-tracking-uninit
2258 Common Report Var(flag_var_tracking_uninit) Optimization
2259 Perform variable tracking and also tag variables that are uninitialized
2262 Common Report Var(flag_tree_vectorize) Optimization
2263 Enable loop vectorization on trees
2265 ftree-vectorizer-verbose=
2266 Common RejectNegative Joined UInteger Var(common_deferred_options) Defer
2267 -ftree-vectorizer-verbose=<number> This switch is deprecated. Use -fopt-info instead.
2270 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2271 Enable basic block vectorization (SLP) on trees
2274 Common Report Var(flag_vect_cost_model) Optimization
2275 Enable use of cost model in vectorization
2277 ftree-vect-loop-version
2278 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2279 Enable loop versioning when doing loop vectorization on trees
2282 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2283 Enable copy propagation of scalar-evolution information.
2285 ; -fverbose-asm causes extra commentary information to be produced in
2286 ; the generated assembly code (to make it more readable). This option
2287 ; is generally only of use to those who actually need to read the
2288 ; generated assembly code (perhaps while debugging the compiler itself).
2289 ; -fno-verbose-asm, the default, causes the extra information
2290 ; to not be added and is useful when comparing two assembler files.
2292 Common Report Var(flag_verbose_asm)
2293 Add extra commentary to assembler output
2296 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2297 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2300 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2303 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2306 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2309 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2312 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2315 Common Report Var(flag_value_profile_transformations) Optimization
2316 Use expression value profiles in optimizations
2319 Common Report Var(flag_web) Init(2) Optimization
2320 Construct webs and split unrelated uses of single variable
2322 ftree-builtin-call-dce
2323 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2324 Enable conditional dead code elimination for builtin calls
2327 Common Report Var(flag_whole_program) Init(0) Optimization
2328 Perform whole program optimizations
2331 Common Report Var(flag_wrapv) Optimization
2332 Assume signed arithmetic overflow wraps around
2334 fzero-initialized-in-bss
2335 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2336 Put zero initialized data in the bss section
2339 Common JoinedOrMissing
2340 Generate debug information in default format
2343 Common JoinedOrMissing Negative(gdwarf)
2344 Generate debug information in COFF format
2347 Common JoinedOrMissing Negative(gdwarf-)
2348 Generate debug information in default version of DWARF format
2351 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2352 Generate debug information in DWARF v2 (or later) format
2355 Common JoinedOrMissing
2356 Generate debug information in default extended format
2359 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2360 Don't generate DWARF pubnames and pubtypes sections.
2363 Common RejectNegative Var(debug_generate_pub_sections, 1)
2364 Generate DWARF pubnames and pubtypes sections.
2366 gno-record-gcc-switches
2367 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2368 Don't record gcc command line switches in DWARF DW_AT_producer.
2370 grecord-gcc-switches
2371 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2372 Record gcc command line switches in DWARF DW_AT_producer.
2375 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2376 Don't generate debug information in separate .dwo files
2379 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2380 Generate debug information in separate .dwo files
2383 Common JoinedOrMissing Negative(gstabs+)
2384 Generate debug information in STABS format
2387 Common JoinedOrMissing Negative(gvms)
2388 Generate debug information in extended STABS format
2391 Common RejectNegative Var(dwarf_strict,0) Init(0)
2392 Emit DWARF additions beyond selected version
2395 Common Report RejectNegative Var(dwarf_strict,1)
2396 Don't emit DWARF additions beyond selected version
2399 Common Report Var(flag_gtoggle)
2400 Toggle debug information generation
2403 Common JoinedOrMissing Negative(gxcoff)
2404 Generate debug information in VMS format
2407 Common JoinedOrMissing Negative(gxcoff+)
2408 Generate debug information in XCOFF format
2411 Common JoinedOrMissing Negative(gcoff)
2412 Generate debug information in extended XCOFF format
2415 Driver Joined Separate
2418 Common Joined Var(plugindir_string) Init(0)
2419 -iplugindir=<dir> Set <dir> to be the default plugin directory
2422 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2423 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2426 Driver Joined Separate
2431 no-canonical-prefixes
2444 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2445 -o <file> Place output into <file>
2448 Common Var(profile_flag)
2449 Enable function profiling
2452 Driver Var(pass_exit_codes)
2455 Common Alias(Wpedantic)
2458 Common Var(flag_pedantic_errors)
2459 Like -pedantic but issue them as errors
2465 Driver Var(use_pipes)
2468 Driver JoinedOrMissing Var(print_file_name)
2470 print-libgcc-file-name
2473 print-multi-directory
2474 Driver Var(print_multi_directory)
2477 Driver Var(print_multi_lib)
2479 print-multi-os-directory
2480 Driver Var(print_multi_os_directory)
2483 Driver Var(print_multiarch)
2486 Driver JoinedOrMissing Var(print_prog_name)
2489 Driver Var(print_search_dirs)
2492 Driver Var(print_sysroot)
2494 print-sysroot-headers-suffix
2495 Driver Var(print_sysroot_headers_suffix)
2498 Common Var(quiet_flag) RejectDriver
2499 Do not display functions compiled or elapsed time
2517 Driver Var(report_times)
2520 Driver JoinedOrMissing
2523 Driver Joined Separate
2527 ; C option, but driver must not handle as "-u ndef".
2530 Common Driver Var(verbose_flag)
2531 Enable verbose output
2534 Common Var(version_flag) RejectDriver
2535 Display the compiler's version
2538 Common Var(inhibit_warnings)
2542 Driver Separate Var(wrapper_string)
2545 Driver Joined Separate
2548 Driver RejectNegative Negative(pie)
2549 Create a shared library
2555 Driver Separate Alias(specs=)
2568 ; Documented for Fortran, but always accepted by driver.
2575 ; Documented for Go, but always accepted by driver.
2587 Driver RejectNegative Negative(shared)
2588 Create a position independent executable
2591 Driver Joined Separate
2593 ; This comment is to ensure we retain the blank line above.