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.
917 Common Var(flag_check_new)
918 Check the return value of new in C++
920 fcombine-stack-adjustments
921 Common Report Var(flag_combine_stack_adjustments) Optimization
922 Looks for opportunities to reduce stack adjustments and stack references.
925 Common Report Var(flag_no_common,0) Optimization
926 Do not put uninitialized globals in the common section
930 ; Converted by the driver to -fcompare-debug= options.
933 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
934 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
936 fcompare-debug-second
937 Common Driver RejectNegative Var(flag_compare_debug)
938 Run only the second compilation of -fcompare-debug
941 Common Report Var(flag_compare_elim_after_reload) Optimization
942 Perform comparison elimination after register allocation has finished
945 Common Var(flag_conserve_stack) Optimization
946 Do not perform optimizations increasing noticeably stack usage
949 Common Report Var(flag_cprop_registers) Optimization
950 Perform a register copy-propagation optimization pass
953 Common Report Var(flag_crossjumping) Optimization
954 Perform cross-jumping optimization
957 Common Report Var(flag_cse_follow_jumps) Optimization
958 When running CSE, follow jumps to their targets
962 Does nothing. Preserved for backward compatibility.
965 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
966 Omit range reduction step when performing complex division
969 Common Report Var(flag_cx_fortran_rules) Optimization
970 Complex multiplication and division follow Fortran rules
973 Common Report Var(flag_data_sections) Optimization
974 Place data items into their own section
977 Common Report Var(common_deferred_options) Defer
978 List all available debugging counters with their limits and counts.
981 Common RejectNegative Joined Var(common_deferred_options) Defer
982 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
985 Common Joined RejectNegative Var(common_deferred_options) Defer
986 Map one directory name to another in debug information
989 Common Report Var(flag_debug_types_section) Init(0)
990 Output .debug_types section when using DWARF v4 debuginfo.
992 ; Nonzero for -fdefer-pop: don't pop args after each function call
993 ; instead save them up to pop many calls' args with one insns.
995 Common Report Var(flag_defer_pop) Optimization
996 Defer popping functions args from stack until later
999 Common Report Var(flag_delayed_branch) Optimization
1000 Attempt to fill delay slots of branch instructions
1002 fdelete-dead-exceptions
1003 Common Report Var(flag_delete_dead_exceptions) Init(0)
1004 Delete dead instructions that may throw exceptions
1006 fdelete-null-pointer-checks
1007 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
1008 Delete useless null pointer checks
1010 fdevirtualize-speculatively
1011 Common Report Var(flag_devirtualize_speculatively) Optimization
1012 Perform speculative devirtualization
1015 Common Report Var(flag_devirtualize) Optimization
1016 Try to convert virtual calls to direct ones.
1018 fdiagnostics-show-location=
1019 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1020 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1022 ; Required for these enum values.
1027 Name(diagnostic_prefixing_rule) Type(int)
1030 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1033 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1035 fdiagnostics-show-caret
1036 Common Var(flag_diagnostics_show_caret) Init(1)
1037 Show the source line with a caret indicating the column
1040 Common Alias(fdiagnostics-color=,always,never)
1044 Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1045 -fdiagnostics-color=[never|always|auto] Colorize diagnostics
1047 ; Required for these enum values.
1052 Name(diagnostic_color_rule) Type(int)
1055 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1058 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1061 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1063 fdiagnostics-show-option
1064 Common Var(flag_diagnostics_show_option) Init(1)
1065 Amend appropriate diagnostic messages with the command line option that controls them
1068 Common Joined RejectNegative Var(common_deferred_options) Defer
1069 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1072 Common Joined RejectNegative Var(common_deferred_options) Defer
1073 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1076 Common Joined RejectNegative Var(common_deferred_options) Defer
1077 -fdump-<type> Dump various compiler internals to a file
1080 Driver RejectNegative
1083 Common RejectNegative Joined Var(flag_dump_final_insns)
1084 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1087 Common RejectNegative Joined Var(flag_dump_go_spec)
1088 -fdump-go-spec=filename Write all declarations to file as Go code
1091 Common Report Var(flag_dump_noaddr)
1092 Suppress output of addresses in debugging dumps
1095 Common Var(flag_dump_passes) Init(0)
1096 Dump optimization passes
1099 Common Report Var(flag_dump_unnumbered)
1100 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1102 fdump-unnumbered-links
1103 Common Report Var(flag_dump_unnumbered_links)
1104 Suppress output of previous and next insn numbers in debugging dumps
1107 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1108 Enable CFI tables via GAS assembler directives.
1111 Common Report Var(flag_early_inlining) Init(1) Optimization
1112 Perform early inlining
1114 feliminate-dwarf2-dups
1115 Common Report Var(flag_eliminate_dwarf2_dups)
1116 Perform DWARF2 duplicate elimination
1119 Common Report Var(flag_ipa_sra) Init(0) Optimization
1120 Perform interprocedural reduction of aggregates
1122 feliminate-unused-debug-symbols
1123 Common Report Var(flag_debug_only_used_symbols)
1124 Perform unused type elimination in debug info
1126 feliminate-unused-debug-types
1127 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1128 Perform unused type elimination in debug info
1130 femit-class-debug-always
1131 Common Report Var(flag_emit_class_debug_always) Init(0)
1132 Do not suppress C++ class debug information.
1135 Common Report Var(flag_exceptions) Optimization
1136 Enable exception handling
1138 fexpensive-optimizations
1139 Common Report Var(flag_expensive_optimizations) Optimization
1140 Perform a number of minor, expensive optimizations
1143 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1144 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1147 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1150 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1153 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1159 Common Var(flag_fat_lto_objects)
1160 Output lto objects containing both the intermediate language and binary output.
1163 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1164 Assume no NaNs or infinities are generated
1167 Common Joined RejectNegative Var(common_deferred_options) Defer
1168 -ffixed-<register> Mark <register> as being unavailable to the compiler
1171 Common Report Var(flag_float_store) Optimization
1172 Don't allocate floats and doubles in extended-precision registers
1176 Does nothing. Preserved for backward compatibility.
1179 Common Report Var(flag_forward_propagate) Optimization
1180 Perform a forward propagation pass on RTL
1183 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1184 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1187 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1190 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1192 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1194 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1197 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1199 ; Nonzero means don't put addresses of constant functions in registers.
1200 ; Used for compiling the Unix kernel, where strange substitutions are
1201 ; done on the assembly output.
1203 Common Report Var(flag_no_function_cse,0)
1204 Allow function addresses to be held in registers
1207 Common Report Var(flag_function_sections)
1208 Place each function into its own section
1211 Common Report Var(flag_gcse) Optimization
1212 Perform global common subexpression elimination
1215 Common Report Var(flag_gcse_lm) Init(1) Optimization
1216 Perform enhanced load motion during global common subexpression elimination
1219 Common Report Var(flag_gcse_sm) Init(0) Optimization
1220 Perform store motion after global common subexpression elimination
1223 Common Report Var(flag_gcse_las) Init(0) Optimization
1224 Perform redundant load after store elimination in global common subexpression
1228 Common Report Var(flag_gcse_after_reload) Optimization
1229 Perform global common subexpression elimination after register allocation
1232 ; This option is not documented yet as its semantics will change.
1234 Common Report Var(flag_graphite)
1235 Enable in and out of Graphite representation
1238 Common Report Var(flag_graphite_identity) Optimization
1239 Enable Graphite Identity transformation
1241 fhoist-adjacent-loads
1242 Common Report Var(flag_hoist_adjacent_loads) Optimization
1243 Enable hoisting adjacent loads to encourage generating conditional move
1246 floop-parallelize-all
1247 Common Report Var(flag_loop_parallelize_all) Optimization
1248 Mark all loops as parallel
1251 Common Report Var(flag_loop_strip_mine) Optimization
1252 Enable Loop Strip Mining transformation
1255 Common Report Var(flag_loop_interchange) Optimization
1256 Enable Loop Interchange transformation
1259 Common Report Var(flag_loop_block) Optimization
1260 Enable Loop Blocking transformation
1263 Common Report Var(flag_tm)
1264 Enable support for GNU transactional memory
1268 Does nothing. Preserved for backward compatibility.
1271 Common Report Var(flag_loop_optimize_isl) Optimization
1272 Enable the ISL based loop nest optimizer
1274 fstrict-volatile-bitfields
1275 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1276 Force bitfield accesses to match their type width
1278 fguess-branch-probability
1279 Common Report Var(flag_guess_branch_prob) Optimization
1280 Enable guessing of branch probabilities
1282 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1283 ; Generate position-independent code for executables if possible
1284 ; On SVR4 targets, it also controls whether or not to emit a
1285 ; string identifying the compiler.
1287 Common Report Var(flag_no_ident,0)
1288 Process #ident directives
1291 Common Report Var(flag_if_conversion) Optimization
1292 Perform conversion of conditional jumps to branchless equivalents
1295 Common Report Var(flag_if_conversion2) Optimization
1296 Perform conversion of conditional jumps to conditional execution
1299 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1300 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1303 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1306 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1309 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1312 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1314 ftree-loop-if-convert
1315 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1316 Convert conditional jumps in innermost loops to branchless equivalents
1318 ftree-loop-if-convert-stores
1319 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1320 Also if-convert conditional jumps containing memory writes
1322 ; -finhibit-size-directive inhibits output of .size for ELF.
1323 ; This is used only for compiling crtstuff.c,
1324 ; and it may be extended to other effects
1325 ; needed for crtstuff.c on other systems.
1326 finhibit-size-directive
1327 Common Report Var(flag_inhibit_size_directive)
1328 Do not generate .size directives
1331 Common Report Var(flag_indirect_inlining)
1332 Perform indirect inlining
1334 ; General flag to enable inlining. Specifying -fno-inline will disable
1335 ; all inlining apart from always-inline functions.
1337 Common Report Var(flag_no_inline,0) Init(0) Optimization
1338 Enable inlining of function declared \"inline\", disabling disables all inlining
1340 finline-small-functions
1341 Common Report Var(flag_inline_small_functions) Optimization
1342 Integrate functions into their callers when code size is known not to grow
1345 Common Report Var(flag_inline_functions) Optimization
1346 Integrate functions not declared \"inline\" into their callers when profitable
1348 finline-functions-called-once
1349 Common Report Var(flag_inline_functions_called_once) Optimization
1350 Integrate functions only required by their single caller
1353 Common RejectNegative Joined Alias(finline-limit=)
1356 Common RejectNegative Joined UInteger
1357 -finline-limit=<number> Limit the size of inlined functions to <number>
1360 Common Report Var(flag_inline_atomics) Init(1) Optimization
1361 Inline __atomic operations when a lock free instruction sequence is available.
1363 finstrument-functions
1364 Common Report Var(flag_instrument_function_entry_exit)
1365 Instrument function entry and exit with profiling calls
1367 finstrument-functions-exclude-function-list=
1368 Common RejectNegative Joined
1369 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1371 finstrument-functions-exclude-file-list=
1372 Common RejectNegative Joined
1373 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1376 Common Report Var(flag_ipa_cp) Optimization
1377 Perform interprocedural constant propagation
1380 Common Report Var(flag_ipa_cp_clone) Optimization
1381 Perform cloning to make Interprocedural constant propagation stronger
1384 Common Report Var(flag_ipa_profile) Init(0) Optimization
1385 Perform interprocedural profile propagation
1388 Common Report Var(flag_ipa_pta) Init(0) Optimization
1389 Perform interprocedural points-to analysis
1392 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1393 Discover pure and const functions
1396 Common Report Var(flag_ipa_sem_equality) Iinit(1) Optimization
1397 Perform Semantic function equality
1400 Common Report Var(flag_ipa_reference) Init(0) Optimization
1401 Discover readonly and non addressable static variables
1405 Does nothing. Preserved for backward compatibility.
1409 Does nothing. Preserved for backward compatibility.
1412 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1413 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1416 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1419 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1422 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1425 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1426 -fira-region=[one|all|mixed] Set regions for IRA
1429 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1432 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1435 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1438 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1441 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1442 Use IRA based register pressure calculation
1443 in RTL hoist optimizations.
1446 Common Report Var(flag_ira_loop_pressure)
1447 Use IRA based register pressure calculation
1448 in RTL loop optimizations.
1450 fira-share-save-slots
1451 Common Report Var(flag_ira_share_save_slots) Init(1)
1452 Share slots for saving different hard registers.
1454 fira-share-spill-slots
1455 Common Report Var(flag_ira_share_spill_slots) Init(1)
1456 Share stack slots for spilled pseudo-registers.
1459 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1460 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1463 Common Report Var(flag_ivopts) Init(1) Optimization
1464 Optimize induction variables on trees
1467 Common Var(flag_jump_tables) Init(1) Optimization
1468 Use jump tables for sufficiently large switch statements
1470 fkeep-inline-functions
1471 Common Report Var(flag_keep_inline_functions)
1472 Generate code for functions even if they are fully inlined
1475 Common Report Var(flag_keep_static_consts) Init(1)
1476 Emit static const variables even if they are not used
1479 Common Report Var(flag_leading_underscore) Init(-1)
1480 Give external symbols a leading underscore
1484 Does nothing. Preserved for backward compatibility.
1488 Enable link-time optimization.
1491 Common RejectNegative Joined Var(flag_lto)
1492 Link-time optimization with number of parallel jobs or jobserver.
1495 Common Var(flag_lto_partition_1to1)
1496 Partition symbols and vars at linktime based on object files they originate from
1498 flto-partition=balanced
1499 Common Var(flag_lto_partition_balanced)
1500 Partition functions and vars at linktime into approximately same sized buckets
1503 Common Var(flag_lto_partition_max)
1504 Put every symbol into separate partition
1507 Common Var(flag_lto_partition_none)
1508 Disable partioning and streaming
1510 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1511 flto-compression-level=
1512 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1513 -flto-compression-level=<number> Use zlib compression level <number> for IL
1516 Common Report Var(flag_lto_report) Init(0)
1517 Report various link-time optimization statistics
1520 Common Report Var(flag_lto_report_wpa) Init(0)
1521 Report various link-time optimization statistics for WPA only
1524 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1525 Set errno after built-in math functions
1528 Common Joined RejectNegative UInteger Var(flag_max_errors)
1529 -fmax-errors=<number> Maximum number of errors to report
1532 Common Report Var(mem_report)
1533 Report on permanent memory allocation
1536 Common Report Var(mem_report_wpa)
1537 Report on permanent memory allocation in WPA only
1539 ; This will attempt to merge constant section constants, if 1 only
1540 ; string constants and constants from constant pool, if 2 also constant
1542 fmerge-all-constants
1543 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1544 Attempt to merge identical constants and constant variables
1547 Common Report Var(flag_merge_constants,1) Optimization
1548 Attempt to merge identical constants across compilation units
1550 fmerge-debug-strings
1551 Common Report Var(flag_merge_debug_strings) Init(1)
1552 Attempt to merge identical debug strings across compilation units
1555 Common RejectNegative Joined UInteger
1556 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1559 Common Report Var(flag_modulo_sched) Optimization
1560 Perform SMS based modulo scheduling before the first scheduling pass
1562 fmodulo-sched-allow-regmoves
1563 Common Report Var(flag_modulo_sched_allow_regmoves)
1564 Perform SMS based modulo scheduling with register moves allowed
1566 fmove-loop-invariants
1567 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1568 Move loop invariant computations out of loops
1571 Common Var(flag_dce) Init(1) Optimization
1572 Use the RTL dead code elimination pass
1575 Common Var(flag_dse) Init(1) Optimization
1576 Use the RTL dead store elimination pass
1578 freschedule-modulo-scheduled-loops
1579 Common Report Var(flag_resched_modulo_sched) Optimization
1580 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1582 fnon-call-exceptions
1583 Common Report Var(flag_non_call_exceptions) Optimization
1584 Support synchronous non-call exceptions
1587 Common Report Var(flag_omit_frame_pointer) Optimization
1588 When possible do not generate stack frames
1591 Common Report Var(flag_opt_info) Optimization
1592 Enable all optimization info dumps on stderr
1595 Common Joined RejectNegative Var(common_deferred_options) Defer
1596 -fopt-info[-<type>=filename] Dump compiler optimization details
1598 foptimize-register-move
1600 Does nothing. Preserved for backward compatibility.
1602 foptimize-sibling-calls
1603 Common Report Var(flag_optimize_sibling_calls) Optimization
1604 Optimize sibling and tail recursive calls
1607 Common Report Var(flag_partial_inlining)
1608 Perform partial inlining
1611 Common Report Var(pre_ipa_mem_report)
1612 Report on memory allocation before interprocedural optimization
1614 fpost-ipa-mem-report
1615 Common Report Var(post_ipa_mem_report)
1616 Report on memory allocation before interprocedural optimization
1619 Common Report Var(flag_pack_struct) Optimization
1620 Pack structure members together without holes
1623 Common RejectNegative Joined UInteger Optimization
1624 -fpack-struct=<number> Set initial maximum structure member alignment
1627 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1628 Return small aggregates in memory, not registers
1631 Common Report Var(flag_peel_loops) Optimization
1632 Perform loop peeling
1635 Common Report Var(flag_no_peephole,0) Optimization
1636 Enable machine specific peephole optimizations
1639 Common Report Var(flag_peephole2) Optimization
1640 Enable an RTL peephole pass before sched2
1643 Common Report Var(flag_pic,2) Negative(fPIE)
1644 Generate position-independent code if possible (large mode)
1647 Common Report Var(flag_pie,2) Negative(fpic)
1648 Generate position-independent code for executables if possible (large mode)
1651 Common Report Var(flag_pic,1) Negative(fpie)
1652 Generate position-independent code if possible (small mode)
1655 Common Report Var(flag_pie,1) Negative(fPIC)
1656 Generate position-independent code for executables if possible (small mode)
1659 Common Joined RejectNegative Var(common_deferred_options) Defer
1660 Specify a plugin to load
1663 Common Joined RejectNegative Var(common_deferred_options) Defer
1664 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1666 fpredictive-commoning
1667 Common Report Var(flag_predictive_commoning) Optimization
1668 Run predictive commoning optimization.
1670 fprefetch-loop-arrays
1671 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1672 Generate prefetch instructions, if available, for arrays in loops
1675 Common Report Var(profile_flag)
1676 Enable basic program profiling code
1679 Common Report Var(profile_arc_flag)
1680 Insert arc-based program profiling code
1683 Common Joined RejectNegative Var(profile_data_prefix)
1684 Set the top-level directory for storing the profile data.
1685 The default is 'pwd'.
1688 Common Report Var(flag_profile_correction)
1689 Enable correction of flow inconsistent profile data input
1693 Enable common options for generating profile info for profile feedback directed optimizations
1696 Common Joined RejectNegative
1697 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1700 Common Var(flag_profile_use)
1701 Enable common options for performing profile feedback directed optimizations
1704 Common Joined RejectNegative
1705 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1708 Common Report Var(flag_profile_values)
1709 Insert code to profile values of expressions
1712 Common Report Var(profile_report)
1713 Report on consistency of profile
1715 fprofile-reorder-functions
1716 Common Report Var(flag_profile_reorder_functions)
1717 Enable function reordering that improves code placement
1720 Common Var(common_deferred_options) Defer
1723 Common Joined RejectNegative Var(common_deferred_options) Defer
1724 -frandom-seed=<string> Make compile reproducible using <string>
1726 ; This switch causes the command line that was used to create an
1727 ; object file to be recorded into the object file. The exact format
1728 ; of this recording is target and binary file format dependent.
1729 ; It is related to the -fverbose-asm switch, but that switch only
1730 ; records information in the assembler output file as comments, so
1731 ; they never reach the object file.
1732 frecord-gcc-switches
1733 Common Report Var(flag_record_gcc_switches)
1734 Record gcc command line switches in the object file.
1737 Common Report Var(flag_pcc_struct_return,0) Optimization
1738 Return small aggregates in registers
1742 Does nothing. Preserved for backward compatibility.
1744 flive-range-shrinkage
1745 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
1746 Relief of register pressure through live range shrinkage
1749 Common Report Var(flag_rename_registers) Init(2) Optimization
1750 Perform a register renaming optimization pass
1753 Common Report Var(flag_reorder_blocks) Optimization
1754 Reorder basic blocks to improve code placement
1756 freorder-blocks-and-partition
1757 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1758 Reorder basic blocks and partition into hot and cold sections
1761 Common Report Var(flag_reorder_functions) Optimization
1762 Reorder functions to improve code placement
1764 frerun-cse-after-loop
1765 Common Report Var(flag_rerun_cse_after_loop) Optimization
1766 Add a common subexpression elimination pass after loop optimizations
1770 Does nothing. Preserved for backward compatibility.
1773 Common Report Var(flag_rounding_math) Optimization SetByCombined
1774 Disable optimizations that assume default FP rounding behavior
1777 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1778 Enable scheduling across basic blocks
1781 Common Report Var(flag_sched_pressure) Init(0) Optimization
1782 Enable register pressure sensitive insn scheduling
1785 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1786 Allow speculative motion of non-loads
1789 Common Report Var(flag_schedule_speculative_load) Optimization
1790 Allow speculative motion of some loads
1792 fsched-spec-load-dangerous
1793 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1794 Allow speculative motion of more loads
1797 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1798 -fsched-verbose=<number> Set the verbosity level of the scheduler
1800 fsched2-use-superblocks
1801 Common Report Var(flag_sched2_use_superblocks) Optimization
1802 If scheduling post reload, do superblock scheduling
1806 Does nothing. Preserved for backward compatibility.
1809 Common Report Var(flag_schedule_insns) Optimization
1810 Reschedule instructions before register allocation
1813 Common Report Var(flag_schedule_insns_after_reload) Optimization
1814 Reschedule instructions after register allocation
1816 ; This flag should be on when a target implements non-trivial
1817 ; scheduling hooks, maybe saving some information for its own sake.
1818 ; On IA64, for example, this is used for correct bundling.
1819 fselective-scheduling
1820 Common Report Var(flag_selective_scheduling) Optimization
1821 Schedule instructions using selective scheduling algorithm
1823 fselective-scheduling2
1824 Common Report Var(flag_selective_scheduling2) Optimization
1825 Run selective scheduling after reload
1827 fsel-sched-pipelining
1828 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1829 Perform software pipelining of inner loops during selective scheduling
1831 fsel-sched-pipelining-outer-loops
1832 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1833 Perform software pipelining of outer loops during selective scheduling
1835 fsel-sched-reschedule-pipelined
1836 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1837 Reschedule pipelined regions without pipelining
1839 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1840 ; of stalled insns into the ready list.
1841 fsched-stalled-insns
1842 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1843 Allow premature scheduling of queued insns
1845 fsched-stalled-insns=
1846 Common RejectNegative Joined UInteger
1847 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1849 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1850 ; be examined for a dependency on a stalled insn that is candidate for
1851 ; premature removal from the queue of stalled insns into the ready list (has
1852 ; an effect only if the flag 'sched_stalled_insns' is set).
1853 fsched-stalled-insns-dep
1854 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1855 Set dependence distance checking in premature scheduling of queued insns
1857 fsched-stalled-insns-dep=
1858 Common RejectNegative Joined UInteger
1859 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1861 fsched-group-heuristic
1862 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1863 Enable the group heuristic in the scheduler
1865 fsched-critical-path-heuristic
1866 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1867 Enable the critical path heuristic in the scheduler
1869 fsched-spec-insn-heuristic
1870 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1871 Enable the speculative instruction heuristic in the scheduler
1873 fsched-rank-heuristic
1874 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1875 Enable the rank heuristic in the scheduler
1877 fsched-last-insn-heuristic
1878 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1879 Enable the last instruction heuristic in the scheduler
1881 fsched-dep-count-heuristic
1882 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1883 Enable the dependent count heuristic in the scheduler
1886 Common Report Var(flag_section_anchors) Optimization
1887 Access data in the same section from shared anchor points
1891 Does nothing. Preserved for backward compatibility.
1895 Does nothing. Preserved for backward compatibility.
1898 Common Report Var(flag_ree) Init(0)
1899 Turn on Redundant Extensions Elimination pass.
1902 Common Report Var(flag_show_column) Init(1)
1903 Show column numbers in diagnostics, when available. Default on
1906 Common Report Var(flag_shrink_wrap) Optimization
1907 Emit function prologues only before parts of the function that need it,
1908 rather than at the top of the function.
1911 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1912 Disable optimizations observable by IEEE signaling NaNs
1915 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1916 Disable floating point optimizations that ignore the IEEE signedness of zero
1918 fsingle-precision-constant
1919 Common Report Var(flag_single_precision_constant) Optimization
1920 Convert floating point constants to single precision constants
1922 fsplit-ivs-in-unroller
1923 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1924 Split lifetimes of induction variables when loops are unrolled
1927 Common Report Var(flag_split_stack) Init(-1)
1928 Generate discontiguous stack frames
1931 Common Report Var(flag_split_wide_types) Optimization
1932 Split wide types into independent registers
1934 fvariable-expansion-in-unroller
1935 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1936 Apply variable expansion when loops are unrolled
1939 Common Report RejectNegative Joined
1940 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1943 Common Alias(fstack-check=, specific, no)
1944 Insert stack checking code into the program. Same as -fstack-check=specific
1947 Common Var(common_deferred_options) Defer
1949 fstack-limit-register=
1950 Common RejectNegative Joined Var(common_deferred_options) Defer
1951 -fstack-limit-register=<register> Trap if the stack goes past <register>
1953 fstack-limit-symbol=
1954 Common RejectNegative Joined Var(common_deferred_options) Defer
1955 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1958 Common Report Var(flag_stack_protect, 1)
1959 Use propolice as a stack protection method
1961 fstack-protector-all
1962 Common Report RejectNegative Var(flag_stack_protect, 2)
1963 Use a stack protection method for every function
1965 fstack-protector-strong
1966 Common Report RejectNegative Var(flag_stack_protect, 3)
1967 Use a smart stack protection method for certain functions
1970 Common RejectNegative Var(flag_stack_usage)
1971 Output stack usage information on a per-function basis
1975 Does nothing. Preserved for backward compatibility.
1977 ; Nonzero if we should do (language-dependent) alias analysis.
1978 ; Typically, this analysis will assume that expressions of certain
1979 ; types do not alias expressions of certain other types. Only used
1980 ; if alias analysis (in general) is enabled.
1982 Common Report Var(flag_strict_aliasing) Optimization
1983 Assume strict aliasing rules apply
1986 Common Report Var(flag_strict_overflow)
1987 Treat signed overflow as undefined
1990 Common Report Var(flag_sync_libcalls) Init(1)
1991 Implement __atomic operations via libcalls to legacy __sync functions
1994 Common Report Var(flag_syntax_only)
1995 Check for syntax errors, then stop
1998 Common Report Var(flag_test_coverage)
1999 Create data files needed by \"gcov\"
2002 Common Report Var(flag_thread_jumps) Optimization
2003 Perform jump threading optimizations
2006 Common Report Var(time_report)
2007 Report the time taken by each compiler pass
2010 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2011 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
2014 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2017 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2020 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2023 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2026 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2029 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2030 Reorder top level functions, variables, and asms
2033 Common Report Var(flag_tracer)
2034 Perform superblock formation via tail duplication
2036 ; Zero means that floating-point math operations cannot generate a
2037 ; (user-visible) trap. This is the case, for example, in nonstop
2038 ; IEEE 754 arithmetic.
2040 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2041 Assume floating-point operations can trap
2044 Common Report Var(flag_trapv) Optimization
2045 Trap for signed overflow in addition, subtraction and multiplication
2048 Common Report Var(flag_tree_ccp) Optimization
2049 Enable SSA-CCP optimization on trees
2052 Common Report Var(flag_tree_bit_ccp) Optimization
2053 Enable SSA-BIT-CCP optimization on trees
2057 Does nothing. Preserved for backward compatibility.
2060 Common Report Var(flag_tree_ch) Optimization
2061 Enable loop header copying on trees
2063 ftree-coalesce-inlined-vars
2064 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2065 Enable coalescing of copy-related user variables that are inlined
2068 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2069 Enable coalescing of all copy-related user variables
2072 Common Report Var(flag_tree_copyrename) Optimization
2073 Replace SSA temporaries with better names in copies
2076 Common Report Var(flag_tree_copy_prop) Optimization
2077 Enable copy propagation on trees
2079 ftree-store-copy-prop
2081 Does nothing. Preserved for backward compatibility.
2084 Common Report Var(flag_tree_cselim) Init(2) Optimization
2085 Transform condition stores into unconditional ones
2087 ftree-switch-conversion
2088 Common Report Var(flag_tree_switch_conversion) Optimization
2089 Perform conversions of switch initializations.
2092 Common Report Var(flag_tree_dce) Optimization
2093 Enable SSA dead code elimination optimization on trees
2095 ftree-dominator-opts
2096 Common Report Var(flag_tree_dom) Optimization
2097 Enable dominator optimizations
2100 Common Report Var(flag_tree_tail_merge) Optimization
2101 Enable tail merging on trees
2104 Common Report Var(flag_tree_dse) Optimization
2105 Enable dead store elimination
2108 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2109 Enable forward propagation on trees
2112 Common Report Var(flag_tree_fre) Optimization
2113 Enable Full Redundancy Elimination (FRE) on trees
2116 Common Report Var(flag_optimize_strlen) Optimization
2117 Enable string length optimizations on trees
2119 fisolate-erroneous-paths-dereference
2120 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2121 Detect paths which trigger erroneous or undefined behaviour due to
2122 dereferencing a NULL pointer. Isolate those paths from the main control
2123 flow and turn the statement with erroneous or undefined behaviour into a trap.
2125 fisolate-erroneous-paths-attribute
2126 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2127 Detect paths which trigger erroneous or undefined behaviour due a NULL value
2128 being used in a way which is forbidden by a returns_nonnull or nonnull
2129 attribute. Isolate those paths from the main control flow and turn the
2130 statement with erroneous or undefined behaviour into a trap.
2132 ftree-loop-distribution
2133 Common Report Var(flag_tree_loop_distribution) Optimization
2134 Enable loop distribution on trees
2136 ftree-loop-distribute-patterns
2137 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2138 Enable loop distribution for patterns transformed into a library call
2141 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2142 Enable loop invariant motion on trees
2145 Common Alias(floop-interchange)
2146 Enable loop interchange transforms. Same as -floop-interchange
2149 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2150 Create canonical induction variables in loops
2153 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2154 Enable loop optimizations on tree level
2156 ftree-parallelize-loops=
2157 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2158 Enable automatic parallelization of loops
2161 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2162 Enable hoisting loads from conditional pointers.
2165 Common Report Var(flag_tree_pre) Optimization
2166 Enable SSA-PRE optimization on trees
2169 Common Report Var(flag_tree_partial_pre) Optimization
2170 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2173 Common Report Var(flag_tree_pta) Init(1) Optimization
2174 Perform function-local points-to analysis on trees.
2177 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2178 Enable reassociation on tree level
2182 Does nothing. Preserved for backward compatibility.
2185 Common Report Var(flag_tree_sink) Optimization
2186 Enable SSA code sinking on trees
2189 Common Report Var(flag_tree_slsr) Optimization
2190 Perform straight-line strength reduction
2193 Common Report Var(flag_tree_sra) Optimization
2194 Perform scalar replacement of aggregates
2197 Common Report Var(flag_tree_ter) Optimization
2198 Replace temporary expressions in the SSA->normal pass
2201 Common Report Var(flag_tree_live_range_split) Optimization
2202 Perform live range splitting during the SSA->normal pass
2205 Common Report Var(flag_tree_vrp) Init(0) Optimization
2206 Perform Value Range Propagation on trees
2209 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2210 Compile whole compilation unit at a time
2213 Common Report Var(flag_unroll_loops) Optimization
2214 Perform loop unrolling when iteration count is known
2217 Common Report Var(flag_unroll_all_loops) Optimization
2218 Perform loop unrolling for all loops
2220 ; Nonzero means that loop optimizer may assume that the induction variables
2221 ; that control loops do not overflow and that the loops with nontrivial
2222 ; exit condition are not infinite
2223 funsafe-loop-optimizations
2224 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2225 Allow loop optimizations to assume that the loops behave in normal way
2228 Common Report Var(flag_associative_math) SetByCombined
2229 Allow optimization for floating-point arithmetic which may change the
2230 result of the operation due to rounding.
2233 Common Report Var(flag_reciprocal_math) SetByCombined
2234 Same as -fassociative-math for expressions which include division.
2236 ; Nonzero means that unsafe floating-point math optimizations are allowed
2237 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2238 ; are allowed to assume that their arguments and results are "normal"
2239 ; (e.g., nonnegative for SQRT).
2240 funsafe-math-optimizations
2241 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2242 Allow math optimizations that may violate IEEE or ISO standards
2245 Common Report Var(flag_unswitch_loops) Optimization
2246 Perform loop unswitching
2249 Common Report Var(flag_unwind_tables) Optimization
2250 Just generate unwind tables for exception handling
2253 Common Negative(fuse-ld=gold)
2254 Use the bfd linker instead of the default linker
2257 Common Negative(fuse-ld=bfd)
2258 Use the gold linker instead of the default linker
2261 Common Undocumented Var(flag_use_linker_plugin)
2263 ; Positive if we should track variables, negative if we should run
2264 ; the var-tracking pass only to discard debug annotations, zero if
2265 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2266 ; will be set according to optimize, debug_info_level and debug_hooks
2267 ; in process_options ().
2269 Common Report Var(flag_var_tracking) Init(2) Optimization
2270 Perform variable tracking
2272 ; Positive if we should track variables at assignments, negative if
2273 ; we should run the var-tracking pass only to discard debug
2274 ; annotations. When flag_var_tracking_assignments ==
2275 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2276 fvar-tracking-assignments
2277 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2278 Perform variable tracking by annotating assignments
2280 ; Nonzero if we should toggle flag_var_tracking_assignments after
2281 ; processing options and computing its default. */
2282 fvar-tracking-assignments-toggle
2283 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2284 Toggle -fvar-tracking-assignments
2286 ; Positive if we should track uninitialized variables, negative if
2287 ; we should run the var-tracking pass only to discard debug
2288 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2289 ; will be set according to flag_var_tracking.
2290 fvar-tracking-uninit
2291 Common Report Var(flag_var_tracking_uninit) Optimization
2292 Perform variable tracking and also tag variables that are uninitialized
2295 Common Report Var(flag_tree_vectorize) Optimization
2296 Enable vectorization on trees
2298 ftree-vectorizer-verbose=
2299 Common Joined RejectNegative Ignore
2300 Does nothing. Preserved for backward compatibility.
2302 ftree-loop-vectorize
2303 Common Report Var(flag_tree_loop_vectorize) Optimization
2304 Enable loop vectorization on trees
2307 Common Report Var(flag_tree_slp_vectorize) Optimization
2308 Enable basic block vectorization (SLP) on trees
2311 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT)
2312 Specifies the cost model for vectorization
2315 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED)
2316 Specifies the vectorization cost model for code marked with a simd directive
2319 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2322 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2325 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2328 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2331 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2332 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2335 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2336 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2338 ftree-vect-loop-version
2340 Does nothing. Preserved for backward compatibility.
2343 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2344 Enable copy propagation of scalar-evolution information.
2346 ; -fverbose-asm causes extra commentary information to be produced in
2347 ; the generated assembly code (to make it more readable). This option
2348 ; is generally only of use to those who actually need to read the
2349 ; generated assembly code (perhaps while debugging the compiler itself).
2350 ; -fno-verbose-asm, the default, causes the extra information
2351 ; to not be added and is useful when comparing two assembler files.
2353 Common Report Var(flag_verbose_asm)
2354 Add extra commentary to assembler output
2357 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2358 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2361 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2364 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2367 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2370 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2373 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2376 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2377 Validate vtable pointers before using them.
2380 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2383 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2386 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2389 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2392 Common Var(flag_vtv_counts)
2393 Output vtable verification counters.
2396 Common Var(flag_vtv_debug)
2397 Output vtable verification pointer sets information.
2400 Common Report Var(flag_value_profile_transformations) Optimization
2401 Use expression value profiles in optimizations
2404 Common Report Var(flag_web) Init(2) Optimization
2405 Construct webs and split unrelated uses of single variable
2407 ftree-builtin-call-dce
2408 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2409 Enable conditional dead code elimination for builtin calls
2412 Common Report Var(flag_whole_program) Init(0) Optimization
2413 Perform whole program optimizations
2416 Common Report Var(flag_wrapv) Optimization
2417 Assume signed arithmetic overflow wraps around
2419 fzero-initialized-in-bss
2420 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2421 Put zero initialized data in the bss section
2424 Common JoinedOrMissing
2425 Generate debug information in default format
2428 Common JoinedOrMissing Negative(gdwarf)
2429 Generate debug information in COFF format
2432 Common JoinedOrMissing Negative(gdwarf-)
2433 Generate debug information in default version of DWARF format
2436 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2437 Generate debug information in DWARF v2 (or later) format
2440 Common JoinedOrMissing
2441 Generate debug information in default extended format
2444 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2445 Don't generate DWARF pubnames and pubtypes sections.
2448 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2449 Generate DWARF pubnames and pubtypes sections.
2452 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2453 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2455 gno-record-gcc-switches
2456 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2457 Don't record gcc command line switches in DWARF DW_AT_producer.
2459 grecord-gcc-switches
2460 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2461 Record gcc command line switches in DWARF DW_AT_producer.
2464 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2465 Don't generate debug information in separate .dwo files
2468 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2469 Generate debug information in separate .dwo files
2472 Common JoinedOrMissing Negative(gstabs+)
2473 Generate debug information in STABS format
2476 Common JoinedOrMissing Negative(gvms)
2477 Generate debug information in extended STABS format
2480 Common RejectNegative Var(dwarf_strict,0) Init(0)
2481 Emit DWARF additions beyond selected version
2484 Common Report RejectNegative Var(dwarf_strict,1)
2485 Don't emit DWARF additions beyond selected version
2488 Common Report Var(flag_gtoggle)
2489 Toggle debug information generation
2492 Common JoinedOrMissing Negative(gxcoff)
2493 Generate debug information in VMS format
2496 Common JoinedOrMissing Negative(gxcoff+)
2497 Generate debug information in XCOFF format
2500 Common JoinedOrMissing Negative(gcoff)
2501 Generate debug information in extended XCOFF format
2504 Driver Joined Separate
2507 Common Joined Var(plugindir_string) Init(0)
2508 -iplugindir=<dir> Set <dir> to be the default plugin directory
2511 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2512 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2515 Driver Joined Separate
2520 no-canonical-prefixes
2533 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2534 -o <file> Place output into <file>
2537 Common Var(profile_flag)
2538 Enable function profiling
2541 Driver Var(pass_exit_codes)
2544 Common Alias(Wpedantic)
2547 Common Var(flag_pedantic_errors)
2548 Like -pedantic but issue them as errors
2554 Driver Var(use_pipes)
2557 Driver JoinedOrMissing Var(print_file_name)
2559 print-libgcc-file-name
2562 print-multi-directory
2563 Driver Var(print_multi_directory)
2566 Driver Var(print_multi_lib)
2568 print-multi-os-directory
2569 Driver Var(print_multi_os_directory)
2572 Driver Var(print_multiarch)
2575 Driver JoinedOrMissing Var(print_prog_name)
2578 Driver Var(print_search_dirs)
2581 Driver Var(print_sysroot)
2583 print-sysroot-headers-suffix
2584 Driver Var(print_sysroot_headers_suffix)
2587 Common Var(quiet_flag) RejectDriver
2588 Do not display functions compiled or elapsed time
2606 Driver Var(report_times)
2609 Driver JoinedOrMissing
2612 Driver Joined Separate
2616 ; C option, but driver must not handle as "-u ndef".
2619 Common Driver Var(verbose_flag)
2620 Enable verbose output
2623 Common Var(version_flag) RejectDriver
2624 Display the compiler's version
2627 Common Var(inhibit_warnings)
2631 Driver Separate Var(wrapper_string)
2634 Driver Joined Separate
2637 Driver RejectNegative Negative(pie)
2638 Create a shared library
2644 Driver Separate Alias(specs=)
2657 ; Documented for Fortran, but always accepted by driver.
2664 ; Documented for Go, but always accepted by driver.
2682 Driver RejectNegative Negative(shared)
2683 Create a position independent executable
2686 Driver Joined Separate
2688 ; This comment is to ensure we retain the blank line above.