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
210 ; What the sanitizer should instrument
212 unsigned int flag_sanitize
224 Driver Alias(coverage)
230 Common Separate Alias(d)
233 Common Joined Alias(d)
236 Common Separate Alias(dumpbase)
239 Common Separate Alias(dumpdir)
242 Driver Separate Alias(e)
245 Driver Joined Alias(e)
248 Common Warning Alias(Wextra)
251 Driver Separate Alias(Xassembler)
254 Driver JoinedOrMissing Alias(Xassembler)
257 Driver Separate Alias(Xlinker)
260 Driver JoinedOrMissing Alias(Xlinker)
263 Driver Separate Alias(u)
266 Driver Joined Alias(u)
269 Common Driver Var(help_flag)
270 Display this information
273 Common Driver Report Joined
274 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
277 Driver Separate Alias(x)
280 Driver Joined Alias(x)
283 Driver Separate Alias(L)
286 Driver Joined Alias(L)
288 -no-canonical-prefixes
289 Driver Alias(no-canonical-prefixes)
291 -no-standard-libraries
292 Driver Alias(nostdlib)
295 Driver Var(no_sysroot_suffix)
304 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
307 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
310 Driver Alias(pass-exit-codes)
313 Common Alias(Wpedantic)
316 Common Alias(pedantic-errors)
325 Driver Separate Alias(B)
328 Driver JoinedOrMissing Alias(B)
334 Driver Separate Alias(print-file-name=)
337 Driver JoinedOrMissing Alias(print-file-name=)
339 -print-libgcc-file-name
340 Driver Alias(print-libgcc-file-name)
342 -print-multi-directory
343 Driver Alias(print-multi-directory)
346 Driver Alias(print-multi-lib)
348 -print-multi-os-directory
349 Driver Alias(print-multi-os-directory)
352 Driver Alias(print-multiarch)
355 Driver Separate Alias(print-prog-name=)
358 Driver JoinedOrMissing Alias(print-prog-name=)
361 Driver Alias(print-search-dirs)
364 Driver Alias(print-sysroot)
366 -print-sysroot-headers-suffix
367 Driver Alias(print-sysroot-headers-suffix)
373 Driver Alias(save-temps)
379 Driver Separate Alias(specs=)
382 Driver Joined Alias(specs=)
388 Driver Alias(symbolic)
392 Alias for --help=target
400 ;; The driver used to convert options such as --help into forms such
401 ;; as -fhelp; the following four entries are for compatibility with
402 ;; any direct uses of those (undocumented) -f forms
404 Common Driver Alias(-help)
407 Common Driver Joined Alias(-help=)
410 Common Driver Alias(-target-help)
413 Common Driver Alias(-version)
417 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
420 Common Joined Alias(-param)
423 Driver Separate Alias(-sysroot=)
426 Driver JoinedOrMissing
432 Driver Joined Separate
438 Driver Joined Separate
444 Common JoinedOrMissing Optimization
445 -O<number> Set optimization level to <number>
449 Optimize for space rather than speed
453 Optimize for speed disregarding exact standards compliance
457 Optimize for debugging experience rather than speed or size
469 Driver Joined Separate
475 Driver Joined Separate
496 Common RejectNegative Warning Alias(Wextra)
497 This switch is deprecated; use -Wextra instead
500 Driver JoinedOrMissing
503 Driver JoinedOrMissing
506 Driver JoinedOrMissing
509 Common Var(warn_aggregate_return) Warning
510 Warn about returning structures, unions or arrays
512 Waggressive-loop-optimizations
513 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
514 Warn if a loop with constant number of iterations triggers undefined behavior
517 Common Var(warn_array_bounds) Warning
518 Warn if an array is accessed out of bounds
521 Common Var(warn_attributes) Init(1) Warning
522 Warn about inappropriate attribute usage
525 Common Var(warn_cast_align) Warning
526 Warn about pointer casts which increase alignment
529 Common Var(warn_cpp) Init(1) Warning
530 Warn when a #warning directive is encountered
532 Wdeprecated-declarations
533 Common Var(warn_deprecated_decl) Init(1) Warning
534 Warn about uses of __attribute__((deprecated)) declarations
536 Wdisabled-optimization
537 Common Var(warn_disabled_optimization) Warning
538 Warn when an optimization pass is disabled
541 Common Var(warnings_are_errors)
542 Treat all warnings as errors
546 Treat specified warning as error
549 Common Var(extra_warnings) Warning
550 Print extra (possibly unwanted) warnings
553 Common Var(flag_fatal_errors)
554 Exit on the first error occurred
557 Common RejectNegative Joined UInteger
558 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
561 Common Var(warn_free_nonheap_object) Init(1) Warning
562 Warn when attempting to free a non-heap object
565 Common Var(warn_inline) Warning
566 Warn when an inlined function cannot be inlined
568 Winvalid-memory-model
569 Common Var(warn_invalid_memory_model) Init(1) Warning
570 Warn when an atomic memory model parameter is known to be outside the valid range.
573 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
576 Common RejectNegative Joined UInteger Warning
577 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
579 Wunsafe-loop-optimizations
580 Common Var(warn_unsafe_loop_optimizations) Warning
581 Warn if the loop cannot be optimized due to nontrivial assumptions.
584 Common Alias(Wsuggest-attribute=noreturn)
587 Common Var(warn_overflow) Init(1) Warning
588 Warn about overflow in arithmetic expressions
591 Common Var(warn_packed) Warning
592 Warn when the packed attribute has no effect on struct layout
595 Common Var(warn_padded) Warning
596 Warn when padding is required to align structure members
599 Common Var(pedantic) Warning
600 Issue warnings needed for strict compliance to the standard
603 Common Var(warn_shadow) Warning
604 Warn when one local variable shadows another
607 Common Var(warn_stack_protect) Warning
608 Warn when not issuing stack smashing protection for some reason
611 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
612 Warn if stack usage might be larger than specified amount
616 Warn about code which might break strict aliasing rules
619 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
620 Warn about code which might break strict aliasing rules
624 Warn about optimizations that assume that signed overflow is undefined
627 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
628 Warn about optimizations that assume that signed overflow is undefined
630 Wsuggest-attribute=const
631 Common Var(warn_suggest_attribute_const) Warning
632 Warn about functions which might be candidates for __attribute__((const))
634 Wsuggest-attribute=pure
635 Common Var(warn_suggest_attribute_pure) Warning
636 Warn about functions which might be candidates for __attribute__((pure))
638 Wsuggest-attribute=noreturn
639 Common Var(warn_suggest_attribute_noreturn) Warning
640 Warn about functions which might be candidates for __attribute__((noreturn))
643 Common Var(warn_system_headers) Warning
644 Do not suppress warnings from system headers
647 Common Var(warn_trampolines) Warning
648 Warn whenever a trampoline is generated
651 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
652 Warn if a comparison is always true or always false due to the limited range of the data type
655 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
656 Warn about uninitialized automatic variables
659 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
660 Warn about maybe uninitialized automatic variables
664 Does nothing. Preserved for backward compatibility.
667 Common Var(warn_unused) Init(0) Warning
668 Enable all -Wunused- warnings
670 Wunused-but-set-parameter
671 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
672 Warn when a function parameter is only set, otherwise unused
674 Wunused-but-set-variable
675 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
676 Warn when a variable is only set, otherwise unused
679 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
680 Warn when a function is unused
683 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
684 Warn when a label is unused
687 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
688 Warn when a function parameter is unused
691 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
692 Warn when an expression value is unused
695 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
696 Warn when a variable is unused
699 Common Var(warn_coverage_mismatch) Init(1) Warning
700 Warn in case profiles in -fprofile-use do not match
702 Wvector-operation-performance
703 Common Var(warn_vector_operation_performance) Warning
704 Warn when a vector operation is compiled outside the SIMD
719 Common Separate Var(aux_info_file_name)
720 -aux-info <file> Emit declaration information into <file>
723 Common Joined Alias(aux-info)
726 Common Separate RejectDriver Var(aux_base_name)
729 Common Separate RejectDriver
739 -d<letters> Enable dumps from specific passes of the compiler
742 Common Separate Var(dump_base_name)
743 -dumpbase <file> Set the file basename to be used for dumps
746 Common Separate Var(dump_dir_name)
747 -dumpdir <dir> Set the directory name to be used for dumps
759 Driver Joined Separate
761 ; This option has historically been passed down to the linker by an
762 ; accident of a %{e*} spec, so ensure it continues to be passed down
763 ; as a single option. The supported option for this purpose is
764 ; -rdynamic. See PR 47390.
768 ; The version of the C++ ABI in use. The following values are allowed:
770 ; 0: The version of the ABI believed most conformant with the C++ ABI
771 ; specification. This ABI may change as bugs are discovered and fixed.
772 ; Therefore, 0 will not necessarily indicate the same ABI in different
775 ; 1: The version of the ABI first used in G++ 3.2.
777 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
779 ; 3: The version of the ABI that fixes the missing underscore
780 ; in template non-type arguments of pointer type.
782 ; 4: The version of the ABI that introduces unambiguous mangling of
783 ; vector types. First selectable in G++ 4.5.
785 ; 5: The version of the ABI that ignores attribute const/noreturn
786 ; in function pointer mangling, and corrects mangling of decltype and
787 ; function parameters used in other parameters and the return type.
788 ; First selectable in G++ 4.6.
790 ; 6: The version of the ABI that doesn't promote scoped enums to int and
791 ; changes the mangling of template argument packs, const/static_cast,
792 ; prefix ++ and --, and a class scope function used as a template
794 ; First selectable in G++ 4.7.
796 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
797 ; corrects the mangling of lambdas in default argument scope.
798 ; First selectable in G++ 4.8.
800 ; 8: The version of the ABI that corrects the substitution behavior of
801 ; function types with function-cv-qualifiers.
802 ; First selectable in G++ 4.9.
804 ; Additional positive integers will be assigned as new versions of
805 ; the ABI become the default version of the ABI.
807 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
809 faggressive-loop-optimizations
810 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
811 Aggressively optimize loops using language constraints
814 Common Report Var(align_functions,0) Optimization UInteger
815 Align the start of functions
818 Common RejectNegative Joined UInteger Var(align_functions)
821 Common Report Var(align_jumps,0) Optimization UInteger
822 Align labels which are only reached by jumping
825 Common RejectNegative Joined UInteger Var(align_jumps)
828 Common Report Var(align_labels,0) Optimization UInteger
832 Common RejectNegative Joined UInteger Var(align_labels)
835 Common Report Var(align_loops,0) Optimization UInteger
836 Align the start of loops
839 Common RejectNegative Joined UInteger Var(align_loops)
843 Does nothing. Preserved for backward compatibility.
847 Does nothing. Preserved for backward compatibility.
849 fargument-noalias-global
851 Does nothing. Preserved for backward compatibility.
853 fargument-noalias-anything
855 Does nothing. Preserved for backward compatibility.
858 Common Driver Report Joined
859 Select what to sanitize
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 fdevirtualize-speculatively
1011 Common Report Var(flag_devirtualize_speculatively) Optimization
1012 Perform speculative devirtualization
1014 fdiagnostics-show-location=
1015 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1016 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1018 ; Required for these enum values.
1023 Name(diagnostic_prefixing_rule) Type(int)
1026 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1029 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1031 fdiagnostics-show-caret
1032 Common Var(flag_diagnostics_show_caret) Init(1)
1033 Show the source line with a caret indicating the column
1036 Common Alias(fdiagnostics-color=,always,never)
1040 Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1041 -fdiagnostics-color=[never|always|auto] Colorize diagnostics
1043 ; Required for these enum values.
1048 Name(diagnostic_color_rule) Type(int)
1051 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1054 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1057 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1059 fdiagnostics-show-option
1060 Common Var(flag_diagnostics_show_option) Init(1)
1061 Amend appropriate diagnostic messages with the command line option that controls them
1064 Common Joined RejectNegative Var(common_deferred_options) Defer
1065 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1068 Common Joined RejectNegative Var(common_deferred_options) Defer
1069 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1072 Common Joined RejectNegative Var(common_deferred_options) Defer
1073 -fdump-<type> Dump various compiler internals to a file
1076 Driver RejectNegative
1079 Common RejectNegative Joined Var(flag_dump_final_insns)
1080 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1083 Common RejectNegative Joined Var(flag_dump_go_spec)
1084 -fdump-go-spec=filename Write all declarations to file as Go code
1087 Common Report Var(flag_dump_noaddr)
1088 Suppress output of addresses in debugging dumps
1091 Common Var(flag_dump_passes) Init(0)
1092 Dump optimization passes
1095 Common Report Var(flag_dump_unnumbered)
1096 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1098 fdump-unnumbered-links
1099 Common Report Var(flag_dump_unnumbered_links)
1100 Suppress output of previous and next insn numbers in debugging dumps
1103 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1104 Enable CFI tables via GAS assembler directives.
1107 Common Report Var(flag_early_inlining) Init(1) Optimization
1108 Perform early inlining
1110 feliminate-dwarf2-dups
1111 Common Report Var(flag_eliminate_dwarf2_dups)
1112 Perform DWARF2 duplicate elimination
1115 Common Report Var(flag_ipa_sra) Init(0) Optimization
1116 Perform interprocedural reduction of aggregates
1118 feliminate-unused-debug-symbols
1119 Common Report Var(flag_debug_only_used_symbols)
1120 Perform unused type elimination in debug info
1122 feliminate-unused-debug-types
1123 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1124 Perform unused type elimination in debug info
1126 femit-class-debug-always
1127 Common Report Var(flag_emit_class_debug_always) Init(0)
1128 Do not suppress C++ class debug information.
1131 Common Report Var(flag_exceptions) Optimization
1132 Enable exception handling
1134 fexpensive-optimizations
1135 Common Report Var(flag_expensive_optimizations) Optimization
1136 Perform a number of minor, expensive optimizations
1139 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1140 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1143 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1146 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1149 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1155 Common Var(flag_fat_lto_objects) Init(1)
1156 Output lto objects containing both the intermediate language and binary output.
1159 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1160 Assume no NaNs or infinities are generated
1163 Common Joined RejectNegative Var(common_deferred_options) Defer
1164 -ffixed-<register> Mark <register> as being unavailable to the compiler
1167 Common Report Var(flag_float_store) Optimization
1168 Don't allocate floats and doubles in extended-precision registers
1172 Does nothing. Preserved for backward compatibility.
1175 Common Report Var(flag_forward_propagate) Optimization
1176 Perform a forward propagation pass on RTL
1179 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1180 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1183 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1186 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1188 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1190 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1193 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1195 ; Nonzero means don't put addresses of constant functions in registers.
1196 ; Used for compiling the Unix kernel, where strange substitutions are
1197 ; done on the assembly output.
1199 Common Report Var(flag_no_function_cse,0)
1200 Allow function addresses to be held in registers
1203 Common Report Var(flag_function_sections)
1204 Place each function into its own section
1207 Common Report Var(flag_gcse) Optimization
1208 Perform global common subexpression elimination
1211 Common Report Var(flag_gcse_lm) Init(1) Optimization
1212 Perform enhanced load motion during global common subexpression elimination
1215 Common Report Var(flag_gcse_sm) Init(0) Optimization
1216 Perform store motion after global common subexpression elimination
1219 Common Report Var(flag_gcse_las) Init(0) Optimization
1220 Perform redundant load after store elimination in global common subexpression
1224 Common Report Var(flag_gcse_after_reload) Optimization
1225 Perform global common subexpression elimination after register allocation
1228 ; This option is not documented yet as its semantics will change.
1230 Common Report Var(flag_graphite)
1231 Enable in and out of Graphite representation
1234 Common Report Var(flag_graphite_identity) Optimization
1235 Enable Graphite Identity transformation
1237 fhoist-adjacent-loads
1238 Common Report Var(flag_hoist_adjacent_loads) Optimization
1239 Enable hoisting adjacent loads to encourage generating conditional move
1242 floop-parallelize-all
1243 Common Report Var(flag_loop_parallelize_all) Optimization
1244 Mark all loops as parallel
1247 Common Report Var(flag_loop_strip_mine) Optimization
1248 Enable Loop Strip Mining transformation
1251 Common Report Var(flag_loop_interchange) Optimization
1252 Enable Loop Interchange transformation
1255 Common Report Var(flag_loop_block) Optimization
1256 Enable Loop Blocking transformation
1259 Common Report Var(flag_tm)
1260 Enable support for GNU transactional memory
1264 Does nothing. Preserved for backward compatibility.
1267 Common Report Var(flag_loop_optimize_isl) Optimization
1268 Enable the ISL based loop nest optimizer
1270 fstrict-volatile-bitfields
1271 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1272 Force bitfield accesses to match their type width
1274 fguess-branch-probability
1275 Common Report Var(flag_guess_branch_prob) Optimization
1276 Enable guessing of branch probabilities
1278 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1279 ; Generate position-independent code for executables if possible
1280 ; On SVR4 targets, it also controls whether or not to emit a
1281 ; string identifying the compiler.
1283 Common Report Var(flag_no_ident,0)
1284 Process #ident directives
1287 Common Report Var(flag_if_conversion) Optimization
1288 Perform conversion of conditional jumps to branchless equivalents
1291 Common Report Var(flag_if_conversion2) Optimization
1292 Perform conversion of conditional jumps to conditional execution
1295 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1296 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1299 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1302 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1305 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1308 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1310 ftree-loop-if-convert
1311 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1312 Convert conditional jumps in innermost loops to branchless equivalents
1314 ftree-loop-if-convert-stores
1315 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1316 Also if-convert conditional jumps containing memory writes
1318 ; -finhibit-size-directive inhibits output of .size for ELF.
1319 ; This is used only for compiling crtstuff.c,
1320 ; and it may be extended to other effects
1321 ; needed for crtstuff.c on other systems.
1322 finhibit-size-directive
1323 Common Report Var(flag_inhibit_size_directive)
1324 Do not generate .size directives
1327 Common Report Var(flag_indirect_inlining)
1328 Perform indirect inlining
1330 ; General flag to enable inlining. Specifying -fno-inline will disable
1331 ; all inlining apart from always-inline functions.
1333 Common Report Var(flag_no_inline,0) Init(0) Optimization
1334 Enable inlining of function declared \"inline\", disabling disables all inlining
1336 finline-small-functions
1337 Common Report Var(flag_inline_small_functions) Optimization
1338 Integrate functions into their callers when code size is known not to grow
1341 Common Report Var(flag_inline_functions) Optimization
1342 Integrate functions not declared \"inline\" into their callers when profitable
1344 finline-functions-called-once
1345 Common Report Var(flag_inline_functions_called_once) Optimization
1346 Integrate functions only required by their single caller
1349 Common RejectNegative Joined Alias(finline-limit=)
1352 Common RejectNegative Joined UInteger
1353 -finline-limit=<number> Limit the size of inlined functions to <number>
1356 Common Report Var(flag_inline_atomics) Init(1) Optimization
1357 Inline __atomic operations when a lock free instruction sequence is available.
1359 finstrument-functions
1360 Common Report Var(flag_instrument_function_entry_exit)
1361 Instrument function entry and exit with profiling calls
1363 finstrument-functions-exclude-function-list=
1364 Common RejectNegative Joined
1365 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1367 finstrument-functions-exclude-file-list=
1368 Common RejectNegative Joined
1369 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1372 Common Report Var(flag_ipa_cp) Optimization
1373 Perform interprocedural constant propagation
1376 Common Report Var(flag_ipa_cp_clone) Optimization
1377 Perform cloning to make Interprocedural constant propagation stronger
1380 Common Report Var(flag_ipa_profile) Init(0) Optimization
1381 Perform interprocedural profile propagation
1384 Common Report Var(flag_ipa_pta) Init(0) Optimization
1385 Perform interprocedural points-to analysis
1388 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1389 Discover pure and const functions
1392 Common Report Var(flag_ipa_reference) Init(0) Optimization
1393 Discover readonly and non addressable static variables
1397 Does nothing. Preserved for backward compatibility.
1401 Does nothing. Preserved for backward compatibility.
1404 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1405 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1408 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1411 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1414 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1417 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1418 -fira-region=[one|all|mixed] Set regions for IRA
1421 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1424 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1427 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1430 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1433 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1434 Use IRA based register pressure calculation
1435 in RTL hoist optimizations.
1438 Common Report Var(flag_ira_loop_pressure)
1439 Use IRA based register pressure calculation
1440 in RTL loop optimizations.
1442 fira-share-save-slots
1443 Common Report Var(flag_ira_share_save_slots) Init(1)
1444 Share slots for saving different hard registers.
1446 fira-share-spill-slots
1447 Common Report Var(flag_ira_share_spill_slots) Init(1)
1448 Share stack slots for spilled pseudo-registers.
1451 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1452 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1455 Common Report Var(flag_ivopts) Init(1) Optimization
1456 Optimize induction variables on trees
1459 Common Var(flag_jump_tables) Init(1) Optimization
1460 Use jump tables for sufficiently large switch statements
1462 fkeep-inline-functions
1463 Common Report Var(flag_keep_inline_functions)
1464 Generate code for functions even if they are fully inlined
1467 Common Report Var(flag_keep_static_consts) Init(1)
1468 Emit static const variables even if they are not used
1471 Common Report Var(flag_leading_underscore) Init(-1)
1472 Give external symbols a leading underscore
1476 Does nothing. Preserved for backward compatibility.
1480 Enable link-time optimization.
1483 Common RejectNegative Joined Var(flag_lto)
1484 Link-time optimization with number of parallel jobs or jobserver.
1487 Common Var(flag_lto_partition_1to1)
1488 Partition symbols and vars at linktime based on object files they originate from
1490 flto-partition=balanced
1491 Common Var(flag_lto_partition_balanced)
1492 Partition functions and vars at linktime into approximately same sized buckets
1495 Common Var(flag_lto_partition_max)
1496 Put every symbol into separate partition
1499 Common Var(flag_lto_partition_none)
1500 Disable partioning and streaming
1502 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1503 flto-compression-level=
1504 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1505 -flto-compression-level=<number> Use zlib compression level <number> for IL
1508 Common Report Var(flag_lto_report) Init(0)
1509 Report various link-time optimization statistics
1512 Common Report Var(flag_lto_report_wpa) Init(0)
1513 Report various link-time optimization statistics for WPA only
1516 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1517 Set errno after built-in math functions
1520 Common Joined RejectNegative UInteger Var(flag_max_errors)
1521 -fmax-errors=<number> Maximum number of errors to report
1524 Common Report Var(mem_report)
1525 Report on permanent memory allocation
1528 Common Report Var(mem_report_wpa)
1529 Report on permanent memory allocation in WPA only
1531 ; This will attempt to merge constant section constants, if 1 only
1532 ; string constants and constants from constant pool, if 2 also constant
1534 fmerge-all-constants
1535 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1536 Attempt to merge identical constants and constant variables
1539 Common Report Var(flag_merge_constants,1) Optimization
1540 Attempt to merge identical constants across compilation units
1542 fmerge-debug-strings
1543 Common Report Var(flag_merge_debug_strings) Init(1)
1544 Attempt to merge identical debug strings across compilation units
1547 Common RejectNegative Joined UInteger
1548 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1551 Common Report Var(flag_modulo_sched) Optimization
1552 Perform SMS based modulo scheduling before the first scheduling pass
1554 fmodulo-sched-allow-regmoves
1555 Common Report Var(flag_modulo_sched_allow_regmoves)
1556 Perform SMS based modulo scheduling with register moves allowed
1558 fmove-loop-invariants
1559 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1560 Move loop invariant computations out of loops
1563 Common Var(flag_dce) Init(1) Optimization
1564 Use the RTL dead code elimination pass
1567 Common Var(flag_dse) Init(1) Optimization
1568 Use the RTL dead store elimination pass
1570 freschedule-modulo-scheduled-loops
1571 Common Report Var(flag_resched_modulo_sched) Optimization
1572 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1574 fnon-call-exceptions
1575 Common Report Var(flag_non_call_exceptions) Optimization
1576 Support synchronous non-call exceptions
1579 Common Report Var(flag_omit_frame_pointer) Optimization
1580 When possible do not generate stack frames
1583 Common Report Var(flag_opt_info) Optimization
1584 Enable all optimization info dumps on stderr
1587 Common Joined RejectNegative Var(common_deferred_options) Defer
1588 -fopt-info[-<type>=filename] Dump compiler optimization details
1590 foptimize-register-move
1591 Common Report Var(flag_regmove) Optimization
1592 Do the full register move optimization pass
1594 foptimize-sibling-calls
1595 Common Report Var(flag_optimize_sibling_calls) Optimization
1596 Optimize sibling and tail recursive calls
1599 Common Report Var(flag_partial_inlining)
1600 Perform partial inlining
1603 Common Report Var(pre_ipa_mem_report)
1604 Report on memory allocation before interprocedural optimization
1606 fpost-ipa-mem-report
1607 Common Report Var(post_ipa_mem_report)
1608 Report on memory allocation before interprocedural optimization
1611 Common Report Var(flag_pack_struct) Optimization
1612 Pack structure members together without holes
1615 Common RejectNegative Joined UInteger Optimization
1616 -fpack-struct=<number> Set initial maximum structure member alignment
1619 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1620 Return small aggregates in memory, not registers
1623 Common Report Var(flag_peel_loops) Optimization
1624 Perform loop peeling
1627 Common Report Var(flag_no_peephole,0) Optimization
1628 Enable machine specific peephole optimizations
1631 Common Report Var(flag_peephole2) Optimization
1632 Enable an RTL peephole pass before sched2
1635 Common Report Var(flag_pic,2) Negative(fPIE)
1636 Generate position-independent code if possible (large mode)
1639 Common Report Var(flag_pie,2) Negative(fpic)
1640 Generate position-independent code for executables if possible (large mode)
1643 Common Report Var(flag_pic,1) Negative(fpie)
1644 Generate position-independent code if possible (small mode)
1647 Common Report Var(flag_pie,1) Negative(fPIC)
1648 Generate position-independent code for executables if possible (small mode)
1651 Common Joined RejectNegative Var(common_deferred_options) Defer
1652 Specify a plugin to load
1655 Common Joined RejectNegative Var(common_deferred_options) Defer
1656 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1658 fpredictive-commoning
1659 Common Report Var(flag_predictive_commoning) Optimization
1660 Run predictive commoning optimization.
1662 fprefetch-loop-arrays
1663 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1664 Generate prefetch instructions, if available, for arrays in loops
1667 Common Report Var(profile_flag)
1668 Enable basic program profiling code
1671 Common Report Var(profile_arc_flag)
1672 Insert arc-based program profiling code
1675 Common Joined RejectNegative Var(profile_data_prefix)
1676 Set the top-level directory for storing the profile data.
1677 The default is 'pwd'.
1680 Common Report Var(flag_profile_correction)
1681 Enable correction of flow inconsistent profile data input
1685 Enable common options for generating profile info for profile feedback directed optimizations
1688 Common Joined RejectNegative
1689 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1692 Common Var(flag_profile_use)
1693 Enable common options for performing profile feedback directed optimizations
1696 Common Joined RejectNegative
1697 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1700 Common Report Var(flag_profile_values)
1701 Insert code to profile values of expressions
1704 Common Report Var(profile_report)
1705 Report on consistency of profile
1708 Common Var(common_deferred_options) Defer
1711 Common Joined RejectNegative Var(common_deferred_options) Defer
1712 -frandom-seed=<string> Make compile reproducible using <string>
1714 ; This switch causes the command line that was used to create an
1715 ; object file to be recorded into the object file. The exact format
1716 ; of this recording is target and binary file format dependent.
1717 ; It is related to the -fverbose-asm switch, but that switch only
1718 ; records information in the assembler output file as comments, so
1719 ; they never reach the object file.
1720 frecord-gcc-switches
1721 Common Report Var(flag_record_gcc_switches)
1722 Record gcc command line switches in the object file.
1725 Common Report Var(flag_pcc_struct_return,0) Optimization
1726 Return small aggregates in registers
1729 Common Report Var(flag_regmove) Optimization
1730 Enables a register move optimization
1733 Common Report Var(flag_rename_registers) Init(2) Optimization
1734 Perform a register renaming optimization pass
1737 Common Report Var(flag_reorder_blocks) Optimization
1738 Reorder basic blocks to improve code placement
1740 freorder-blocks-and-partition
1741 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1742 Reorder basic blocks and partition into hot and cold sections
1745 Common Report Var(flag_reorder_functions) Optimization
1746 Reorder functions to improve code placement
1748 frerun-cse-after-loop
1749 Common Report Var(flag_rerun_cse_after_loop) Optimization
1750 Add a common subexpression elimination pass after loop optimizations
1754 Does nothing. Preserved for backward compatibility.
1757 Common Report Var(flag_rounding_math) Optimization SetByCombined
1758 Disable optimizations that assume default FP rounding behavior
1761 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1762 Enable scheduling across basic blocks
1765 Common Report Var(flag_sched_pressure) Init(0) Optimization
1766 Enable register pressure sensitive insn scheduling
1769 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1770 Allow speculative motion of non-loads
1773 Common Report Var(flag_schedule_speculative_load) Optimization
1774 Allow speculative motion of some loads
1776 fsched-spec-load-dangerous
1777 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1778 Allow speculative motion of more loads
1781 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1782 -fsched-verbose=<number> Set the verbosity level of the scheduler
1784 fsched2-use-superblocks
1785 Common Report Var(flag_sched2_use_superblocks) Optimization
1786 If scheduling post reload, do superblock scheduling
1790 Does nothing. Preserved for backward compatibility.
1793 Common Report Var(flag_schedule_insns) Optimization
1794 Reschedule instructions before register allocation
1797 Common Report Var(flag_schedule_insns_after_reload) Optimization
1798 Reschedule instructions after register allocation
1800 ; This flag should be on when a target implements non-trivial
1801 ; scheduling hooks, maybe saving some information for its own sake.
1802 ; On IA64, for example, this is used for correct bundling.
1803 fselective-scheduling
1804 Common Report Var(flag_selective_scheduling) Optimization
1805 Schedule instructions using selective scheduling algorithm
1807 fselective-scheduling2
1808 Common Report Var(flag_selective_scheduling2) Optimization
1809 Run selective scheduling after reload
1811 fsel-sched-pipelining
1812 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1813 Perform software pipelining of inner loops during selective scheduling
1815 fsel-sched-pipelining-outer-loops
1816 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1817 Perform software pipelining of outer loops during selective scheduling
1819 fsel-sched-reschedule-pipelined
1820 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1821 Reschedule pipelined regions without pipelining
1823 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1824 ; of stalled insns into the ready list.
1825 fsched-stalled-insns
1826 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1827 Allow premature scheduling of queued insns
1829 fsched-stalled-insns=
1830 Common RejectNegative Joined UInteger
1831 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1833 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1834 ; be examined for a dependency on a stalled insn that is candidate for
1835 ; premature removal from the queue of stalled insns into the ready list (has
1836 ; an effect only if the flag 'sched_stalled_insns' is set).
1837 fsched-stalled-insns-dep
1838 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1839 Set dependence distance checking in premature scheduling of queued insns
1841 fsched-stalled-insns-dep=
1842 Common RejectNegative Joined UInteger
1843 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1845 fsched-group-heuristic
1846 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1847 Enable the group heuristic in the scheduler
1849 fsched-critical-path-heuristic
1850 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1851 Enable the critical path heuristic in the scheduler
1853 fsched-spec-insn-heuristic
1854 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1855 Enable the speculative instruction heuristic in the scheduler
1857 fsched-rank-heuristic
1858 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1859 Enable the rank heuristic in the scheduler
1861 fsched-last-insn-heuristic
1862 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1863 Enable the last instruction heuristic in the scheduler
1865 fsched-dep-count-heuristic
1866 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1867 Enable the dependent count heuristic in the scheduler
1870 Common Report Var(flag_section_anchors) Optimization
1871 Access data in the same section from shared anchor points
1875 Does nothing. Preserved for backward compatibility.
1879 Does nothing. Preserved for backward compatibility.
1882 Common Report Var(flag_ree) Init(0)
1883 Turn on Redundant Extensions Elimination pass.
1886 Common Report Var(flag_show_column) Init(1)
1887 Show column numbers in diagnostics, when available. Default on
1890 Common Report Var(flag_shrink_wrap) Optimization
1891 Emit function prologues only before parts of the function that need it,
1892 rather than at the top of the function.
1895 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1896 Disable optimizations observable by IEEE signaling NaNs
1899 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1900 Disable floating point optimizations that ignore the IEEE signedness of zero
1902 fsingle-precision-constant
1903 Common Report Var(flag_single_precision_constant) Optimization
1904 Convert floating point constants to single precision constants
1906 fsplit-ivs-in-unroller
1907 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1908 Split lifetimes of induction variables when loops are unrolled
1911 Common Report Var(flag_split_stack) Init(-1)
1912 Generate discontiguous stack frames
1915 Common Report Var(flag_split_wide_types) Optimization
1916 Split wide types into independent registers
1918 fvariable-expansion-in-unroller
1919 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1920 Apply variable expansion when loops are unrolled
1923 Common Report RejectNegative Joined
1924 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1927 Common Alias(fstack-check=, specific, no)
1928 Insert stack checking code into the program. Same as -fstack-check=specific
1931 Common Var(common_deferred_options) Defer
1933 fstack-limit-register=
1934 Common RejectNegative Joined Var(common_deferred_options) Defer
1935 -fstack-limit-register=<register> Trap if the stack goes past <register>
1937 fstack-limit-symbol=
1938 Common RejectNegative Joined Var(common_deferred_options) Defer
1939 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1942 Common Report Var(flag_stack_protect, 1)
1943 Use propolice as a stack protection method
1945 fstack-protector-all
1946 Common Report RejectNegative Var(flag_stack_protect, 2)
1947 Use a stack protection method for every function
1949 fstack-protector-strong
1950 Common Report RejectNegative Var(flag_stack_protect, 3)
1951 Use a smart stack protection method for certain functions
1954 Common RejectNegative Var(flag_stack_usage)
1955 Output stack usage information on a per-function basis
1959 Does nothing. Preserved for backward compatibility.
1961 ; Nonzero if we should do (language-dependent) alias analysis.
1962 ; Typically, this analysis will assume that expressions of certain
1963 ; types do not alias expressions of certain other types. Only used
1964 ; if alias analysis (in general) is enabled.
1966 Common Report Var(flag_strict_aliasing) Optimization
1967 Assume strict aliasing rules apply
1970 Common Report Var(flag_strict_overflow)
1971 Treat signed overflow as undefined
1974 Common Report Var(flag_sync_libcalls) Init(1)
1975 Implement __atomic operations via libcalls to legacy __sync functions
1978 Common Report Var(flag_syntax_only)
1979 Check for syntax errors, then stop
1982 Common Report Var(flag_test_coverage)
1983 Create data files needed by \"gcov\"
1986 Common Report Var(flag_thread_jumps) Optimization
1987 Perform jump threading optimizations
1990 Common Report Var(time_report)
1991 Report the time taken by each compiler pass
1994 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1995 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1998 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2001 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2004 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2007 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2010 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2013 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2014 Reorder top level functions, variables, and asms
2017 Common Report Var(flag_tracer)
2018 Perform superblock formation via tail duplication
2020 ; Zero means that floating-point math operations cannot generate a
2021 ; (user-visible) trap. This is the case, for example, in nonstop
2022 ; IEEE 754 arithmetic.
2024 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2025 Assume floating-point operations can trap
2028 Common Report Var(flag_trapv) Optimization
2029 Trap for signed overflow in addition, subtraction and multiplication
2032 Common Report Var(flag_tree_ccp) Optimization
2033 Enable SSA-CCP optimization on trees
2036 Common Report Var(flag_tree_bit_ccp) Optimization
2037 Enable SSA-BIT-CCP optimization on trees
2041 Does nothing. Preserved for backward compatibility.
2044 Common Report Var(flag_tree_ch) Optimization
2045 Enable loop header copying on trees
2047 ftree-coalesce-inlined-vars
2048 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2049 Enable coalescing of copy-related user variables that are inlined
2052 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2053 Enable coalescing of all copy-related user variables
2056 Common Report Var(flag_tree_copyrename) Optimization
2057 Replace SSA temporaries with better names in copies
2060 Common Report Var(flag_tree_copy_prop) Optimization
2061 Enable copy propagation on trees
2063 ftree-store-copy-prop
2065 Does nothing. Preserved for backward compatibility.
2068 Common Report Var(flag_tree_cselim) Init(2) Optimization
2069 Transform condition stores into unconditional ones
2071 ftree-switch-conversion
2072 Common Report Var(flag_tree_switch_conversion) Optimization
2073 Perform conversions of switch initializations.
2076 Common Report Var(flag_tree_dce) Optimization
2077 Enable SSA dead code elimination optimization on trees
2079 ftree-dominator-opts
2080 Common Report Var(flag_tree_dom) Optimization
2081 Enable dominator optimizations
2084 Common Report Var(flag_tree_tail_merge) Optimization
2085 Enable tail merging on trees
2088 Common Report Var(flag_tree_dse) Optimization
2089 Enable dead store elimination
2092 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2093 Enable forward propagation on trees
2096 Common Report Var(flag_tree_fre) Optimization
2097 Enable Full Redundancy Elimination (FRE) on trees
2100 Common Report Var(flag_optimize_strlen) Optimization
2101 Enable string length optimizations on trees
2103 ftree-loop-distribution
2104 Common Report Var(flag_tree_loop_distribution) Optimization
2105 Enable loop distribution on trees
2107 ftree-loop-distribute-patterns
2108 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2109 Enable loop distribution for patterns transformed into a library call
2112 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2113 Enable loop invariant motion on trees
2116 Common Alias(floop-interchange)
2117 Enable loop interchange transforms. Same as -floop-interchange
2120 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2121 Create canonical induction variables in loops
2124 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2125 Enable loop optimizations on tree level
2127 ftree-parallelize-loops=
2128 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2129 Enable automatic parallelization of loops
2132 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2133 Enable hoisting loads from conditional pointers.
2136 Common Report Var(flag_tree_pre) Optimization
2137 Enable SSA-PRE optimization on trees
2140 Common Report Var(flag_tree_partial_pre) Optimization
2141 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2144 Common Report Var(flag_tree_pta) Init(1) Optimization
2145 Perform function-local points-to analysis on trees.
2148 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2149 Enable reassociation on tree level
2153 Does nothing. Preserved for backward compatibility.
2156 Common Report Var(flag_tree_sink) Optimization
2157 Enable SSA code sinking on trees
2160 Common Report Var(flag_tree_slsr) Optimization
2161 Perform straight-line strength reduction
2164 Common Report Var(flag_tree_sra) Optimization
2165 Perform scalar replacement of aggregates
2168 Common Report Var(flag_tree_ter) Optimization
2169 Replace temporary expressions in the SSA->normal pass
2172 Common Report Var(flag_tree_live_range_split) Optimization
2173 Perform live range splitting during the SSA->normal pass
2176 Common Report Var(flag_tree_vrp) Init(0) Optimization
2177 Perform Value Range Propagation on trees
2180 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2181 Compile whole compilation unit at a time
2184 Common Report Var(flag_unroll_loops) Optimization
2185 Perform loop unrolling when iteration count is known
2188 Common Report Var(flag_unroll_all_loops) Optimization
2189 Perform loop unrolling for all loops
2191 ; Nonzero means that loop optimizer may assume that the induction variables
2192 ; that control loops do not overflow and that the loops with nontrivial
2193 ; exit condition are not infinite
2194 funsafe-loop-optimizations
2195 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2196 Allow loop optimizations to assume that the loops behave in normal way
2199 Common Report Var(flag_associative_math) SetByCombined
2200 Allow optimization for floating-point arithmetic which may change the
2201 result of the operation due to rounding.
2204 Common Report Var(flag_reciprocal_math) SetByCombined
2205 Same as -fassociative-math for expressions which include division.
2207 ; Nonzero means that unsafe floating-point math optimizations are allowed
2208 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2209 ; are allowed to assume that their arguments and results are "normal"
2210 ; (e.g., nonnegative for SQRT).
2211 funsafe-math-optimizations
2212 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2213 Allow math optimizations that may violate IEEE or ISO standards
2216 Common Report Var(flag_unswitch_loops) Optimization
2217 Perform loop unswitching
2220 Common Report Var(flag_unwind_tables) Optimization
2221 Just generate unwind tables for exception handling
2224 Common Negative(fuse-ld=gold)
2225 Use the bfd linker instead of the default linker
2228 Common Negative(fuse-ld=bfd)
2229 Use the gold linker instead of the default linker
2234 ; Positive if we should track variables, negative if we should run
2235 ; the var-tracking pass only to discard debug annotations, zero if
2236 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2237 ; will be set according to optimize, debug_info_level and debug_hooks
2238 ; in process_options ().
2240 Common Report Var(flag_var_tracking) Init(2) Optimization
2241 Perform variable tracking
2243 ; Positive if we should track variables at assignments, negative if
2244 ; we should run the var-tracking pass only to discard debug
2245 ; annotations. When flag_var_tracking_assignments ==
2246 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2247 fvar-tracking-assignments
2248 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2249 Perform variable tracking by annotating assignments
2251 ; Nonzero if we should toggle flag_var_tracking_assignments after
2252 ; processing options and computing its default. */
2253 fvar-tracking-assignments-toggle
2254 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2255 Toggle -fvar-tracking-assignments
2257 ; Positive if we should track uninitialized variables, negative if
2258 ; we should run the var-tracking pass only to discard debug
2259 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2260 ; will be set according to flag_var_tracking.
2261 fvar-tracking-uninit
2262 Common Report Var(flag_var_tracking_uninit) Optimization
2263 Perform variable tracking and also tag variables that are uninitialized
2266 Common Report Var(flag_tree_vectorize) Optimization
2267 Enable loop vectorization on trees
2269 ftree-vectorizer-verbose=
2270 Common RejectNegative Joined UInteger Var(common_deferred_options) Defer
2271 -ftree-vectorizer-verbose=<number> This switch is deprecated. Use -fopt-info instead.
2274 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2275 Enable basic block vectorization (SLP) on trees
2278 Common Report Var(flag_vect_cost_model) Optimization
2279 Enable use of cost model in vectorization
2281 ftree-vect-loop-version
2282 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2283 Enable loop versioning when doing loop vectorization on trees
2286 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2287 Enable copy propagation of scalar-evolution information.
2289 ; -fverbose-asm causes extra commentary information to be produced in
2290 ; the generated assembly code (to make it more readable). This option
2291 ; is generally only of use to those who actually need to read the
2292 ; generated assembly code (perhaps while debugging the compiler itself).
2293 ; -fno-verbose-asm, the default, causes the extra information
2294 ; to not be added and is useful when comparing two assembler files.
2296 Common Report Var(flag_verbose_asm)
2297 Add extra commentary to assembler output
2300 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2301 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2304 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2307 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2310 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2313 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2316 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2319 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2320 Validate vtable pointers before using them.
2323 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2326 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2329 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2332 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2335 Common Var(flag_vtv_counts)
2336 Output vtable verification counters.
2339 Common Var(flag_vtv_debug)
2340 Output vtable verification pointer sets information.
2343 Common Report Var(flag_value_profile_transformations) Optimization
2344 Use expression value profiles in optimizations
2347 Common Report Var(flag_web) Init(2) Optimization
2348 Construct webs and split unrelated uses of single variable
2350 ftree-builtin-call-dce
2351 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2352 Enable conditional dead code elimination for builtin calls
2355 Common Report Var(flag_whole_program) Init(0) Optimization
2356 Perform whole program optimizations
2359 Common Report Var(flag_wrapv) Optimization
2360 Assume signed arithmetic overflow wraps around
2362 fzero-initialized-in-bss
2363 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2364 Put zero initialized data in the bss section
2367 Common JoinedOrMissing
2368 Generate debug information in default format
2371 Common JoinedOrMissing Negative(gdwarf)
2372 Generate debug information in COFF format
2375 Common JoinedOrMissing Negative(gdwarf-)
2376 Generate debug information in default version of DWARF format
2379 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2380 Generate debug information in DWARF v2 (or later) format
2383 Common JoinedOrMissing
2384 Generate debug information in default extended format
2387 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2388 Don't generate DWARF pubnames and pubtypes sections.
2391 Common RejectNegative Var(debug_generate_pub_sections, 1)
2392 Generate DWARF pubnames and pubtypes sections.
2394 gno-record-gcc-switches
2395 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2396 Don't record gcc command line switches in DWARF DW_AT_producer.
2398 grecord-gcc-switches
2399 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2400 Record gcc command line switches in DWARF DW_AT_producer.
2403 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2404 Don't generate debug information in separate .dwo files
2407 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2408 Generate debug information in separate .dwo files
2411 Common JoinedOrMissing Negative(gstabs+)
2412 Generate debug information in STABS format
2415 Common JoinedOrMissing Negative(gvms)
2416 Generate debug information in extended STABS format
2419 Common RejectNegative Var(dwarf_strict,0) Init(0)
2420 Emit DWARF additions beyond selected version
2423 Common Report RejectNegative Var(dwarf_strict,1)
2424 Don't emit DWARF additions beyond selected version
2427 Common Report Var(flag_gtoggle)
2428 Toggle debug information generation
2431 Common JoinedOrMissing Negative(gxcoff)
2432 Generate debug information in VMS format
2435 Common JoinedOrMissing Negative(gxcoff+)
2436 Generate debug information in XCOFF format
2439 Common JoinedOrMissing Negative(gcoff)
2440 Generate debug information in extended XCOFF format
2443 Driver Joined Separate
2446 Common Joined Var(plugindir_string) Init(0)
2447 -iplugindir=<dir> Set <dir> to be the default plugin directory
2450 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2451 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2454 Driver Joined Separate
2459 no-canonical-prefixes
2472 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2473 -o <file> Place output into <file>
2476 Common Var(profile_flag)
2477 Enable function profiling
2480 Driver Var(pass_exit_codes)
2483 Common Alias(Wpedantic)
2486 Common Var(flag_pedantic_errors)
2487 Like -pedantic but issue them as errors
2493 Driver Var(use_pipes)
2496 Driver JoinedOrMissing Var(print_file_name)
2498 print-libgcc-file-name
2501 print-multi-directory
2502 Driver Var(print_multi_directory)
2505 Driver Var(print_multi_lib)
2507 print-multi-os-directory
2508 Driver Var(print_multi_os_directory)
2511 Driver Var(print_multiarch)
2514 Driver JoinedOrMissing Var(print_prog_name)
2517 Driver Var(print_search_dirs)
2520 Driver Var(print_sysroot)
2522 print-sysroot-headers-suffix
2523 Driver Var(print_sysroot_headers_suffix)
2526 Common Var(quiet_flag) RejectDriver
2527 Do not display functions compiled or elapsed time
2545 Driver Var(report_times)
2548 Driver JoinedOrMissing
2551 Driver Joined Separate
2555 ; C option, but driver must not handle as "-u ndef".
2558 Common Driver Var(verbose_flag)
2559 Enable verbose output
2562 Common Var(version_flag) RejectDriver
2563 Display the compiler's version
2566 Common Var(inhibit_warnings)
2570 Driver Separate Var(wrapper_string)
2573 Driver Joined Separate
2576 Driver RejectNegative Negative(pie)
2577 Create a shared library
2583 Driver Separate Alias(specs=)
2596 ; Documented for Fortran, but always accepted by driver.
2603 ; Documented for Go, but always accepted by driver.
2618 Driver RejectNegative Negative(shared)
2619 Create a position independent executable
2622 Driver Joined Separate
2624 ; This comment is to ensure we retain the blank line above.