1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 ; Free Software Foundation, Inc.
6 ; This file is part of GCC.
8 ; GCC is free software; you can redistribute it and/or modify it under
9 ; the terms of the GNU General Public License as published by the Free
10 ; Software Foundation; either version 3, or (at your option) any later
13 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 ; You should have received a copy of the GNU General Public License
19 ; along with GCC; see the file COPYING3. If not see
20 ; <http://www.gnu.org/licenses/>.
22 ; See the GCC internals manual (options.texi) for a description of this file's format.
24 ; Please try to keep this file in ASCII collating order.
35 ; Not used directly to control optimizations, only to save -Ofast
36 ; setting for "optimize" attributes.
40 ; True if this is the lto front end. This is used to disable gimple
41 ; generation and lowering passes that are normally run on the output
42 ; of a front end. These passes must be bypassed for lto since they
43 ; have already been done before the gimple was written.
47 ; 0 means straightforward implementation of complex divide acceptable.
48 ; 1 means wide ranges of inputs must work for complex divide.
49 ; 2 means C99-like requirements for complex multiply and divide.
51 int flag_complex_method = 1
53 ; Nonzero if subexpressions must be evaluated from left-to-right.
55 int flag_evaluation_order = 0
57 ; Language specific warning pass for unused results.
59 bool flag_warn_unused_result = false
64 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
68 ; True to warn about any objects definitions whose size is larger
69 ; than N bytes. Also want about function definitions whose returned
70 ; values are larger than N bytes, where N is 'larger_than_size'.
75 HOST_WIDE_INT larger_than_size
77 ; True to warn about any function whose frame size is larger
80 bool warn_frame_larger_than
83 HOST_WIDE_INT frame_larger_than_size
85 ; Nonzero means we should be saving declaration info into a .X file.
87 int flag_gen_aux_info = 0
89 ; Nonzero if we are compiling code for a shared library, zero for
94 ; These two are really VEC(char_p,heap) *.
97 void *flag_instrument_functions_exclude_functions
100 void *flag_instrument_functions_exclude_files
102 ; Generic structs (e.g. templates not explicitly specialized)
103 ; may not have a compilation unit associated with them, and so
104 ; may need to be treated differently from ordinary structs.
106 ; Structs only handled by reference (indirectly), will also usually
107 ; not need as much debugging information.
110 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
113 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 ; True if we should exit after parsing options.
117 bool exit_after_options
119 ; Type(s) of debugging information we are producing (if any). See
120 ; flag-types.h for the definitions of the different possible types of
121 ; debugging information.
123 enum debug_info_type write_symbols = NO_DEBUG
125 ; Level of debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
130 ; Nonzero means use GNU-only extensions in the generated symbolic
131 ; debugging information. Currently, this only has an effect when
132 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
134 bool use_gnu_debug_info_extensions
136 ; Original value of maximum field alignment in bytes, specified via
137 ; -fpack-struct=<value>.
139 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
142 enum vect_verbosity_levels user_vect_verbosity_level = MAX_VERBOSITY_LEVEL
144 ; Type of stack check.
146 enum stack_check_type flag_stack_check = NO_STACK_CHECK
148 ; True if stack usage information needs to be computed.
150 bool flag_stack_usage_info = false
152 ; -dA causes debug commentary information to be produced in
153 ; the generated assembly code (to make it more readable). This option
154 ; is generally only of use to those who actually need to read the
155 ; generated assembly code (perhaps while debugging the compiler itself).
156 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
157 ; to be a catchall for printing debug information in the assembler file.
161 ; -dP causes the rtl to be emitted as a comment in assembly.
163 int flag_dump_rtl_in_asm
165 ; Whether -da was passed (used only in handle_common_deferred_options).
167 bool flag_dump_all_passed
169 ; Other flags saying which kinds of debugging dump have been requested.
172 int rtl_dump_and_exit
175 int flag_print_asm_name
178 enum graph_dump_types graph_dump_format = no_graph
180 ; Name of top-level original source file (what was input to cpp).
181 ; This comes from the #-command at the beginning of the actual input.
182 ; If there isn't any there, then this is the cc1 input file name.
184 const char *main_input_filename
186 ; Pointer to base name in main_input_filename, with directories and a
187 ; single final extension removed, and the length of this base
191 const char *main_input_basename
194 int main_input_baselength
196 ; Which options have been printed by --help.
200 ; Which enums have been printed by --help. 0 = not printed, no
201 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
204 char *help_enum_printed
206 ; The number of columns for --help output.
208 unsigned int help_columns
210 ; Whether this options structure has been through finish_options
212 bool flag_opts_finished
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)
301 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
304 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
307 Driver Alias(pass-exit-codes)
310 Common Alias(Wpedantic)
313 Common Alias(pedantic-errors)
322 Driver Separate Alias(B)
325 Driver JoinedOrMissing Alias(B)
331 Driver Separate Alias(print-file-name=)
334 Driver JoinedOrMissing Alias(print-file-name=)
336 -print-libgcc-file-name
337 Driver Alias(print-libgcc-file-name)
339 -print-multi-directory
340 Driver Alias(print-multi-directory)
343 Driver Alias(print-multi-lib)
345 -print-multi-os-directory
346 Driver Alias(print-multi-os-directory)
349 Driver Separate Alias(print-prog-name=)
352 Driver JoinedOrMissing Alias(print-prog-name=)
355 Driver Alias(print-search-dirs)
358 Driver Alias(print-sysroot)
360 -print-sysroot-headers-suffix
361 Driver Alias(print-sysroot-headers-suffix)
367 Driver Alias(save-temps)
373 Driver Separate Alias(specs=)
376 Driver Joined Alias(specs=)
382 Driver Alias(symbolic)
386 Alias for --help=target
394 ;; The driver used to convert options such as --help into forms such
395 ;; as -fhelp; the following four entries are for compatibility with
396 ;; any direct uses of those (undocumented) -f forms
398 Common Driver Alias(-help)
401 Common Driver Joined Alias(-help=)
404 Common Driver Alias(-target-help)
407 Common Driver Alias(-version)
411 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
414 Common Joined Alias(-param)
417 Driver Separate Alias(-sysroot=)
420 Driver JoinedOrMissing
426 Driver Joined Separate
432 Driver Joined Separate
438 Common JoinedOrMissing Optimization
439 -O<number> Set optimization level to <number>
443 Optimize for space rather than speed
447 Optimize for speed disregarding exact standards compliance
459 Driver Joined Separate
465 Driver Joined Separate
486 Common RejectNegative Warning Alias(Wextra)
487 This switch is deprecated; use -Wextra instead
490 Driver JoinedOrMissing
493 Driver JoinedOrMissing
496 Driver JoinedOrMissing
499 Common Var(warn_aggregate_return) Warning
500 Warn about returning structures, unions or arrays
503 Common Var(warn_array_bounds) Warning
504 Warn if an array is accessed out of bounds
507 Common Var(warn_attributes) Init(1) Warning
508 Warn about inappropriate attribute usage
511 Common Var(warn_cast_align) Warning
512 Warn about pointer casts which increase alignment
515 Common Var(warn_cpp) Init(1) Warning
516 Warn when a #warning directive is encountered
518 Wdeprecated-declarations
519 Common Var(warn_deprecated_decl) Init(1) Warning
520 Warn about uses of __attribute__((deprecated)) declarations
522 Wdisabled-optimization
523 Common Var(warn_disabled_optimization) Warning
524 Warn when an optimization pass is disabled
527 Common Var(warnings_are_errors)
528 Treat all warnings as errors
532 Treat specified warning as error
535 Common Var(extra_warnings) Warning
536 Print extra (possibly unwanted) warnings
539 Common Var(flag_fatal_errors)
540 Exit on the first error occurred
543 Common RejectNegative Joined UInteger
544 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
547 Common Var(warn_free_nonheap_object) Init(1) Warning
548 Warn when attempting to free a non-heap object
551 Common Var(warn_inline) Warning
552 Warn when an inlined function cannot be inlined
554 Winvalid-memory-model
555 Common Var(warn_invalid_memory_model) Init(1) Warning
556 Warn when an atomic memory model parameter is known to be outside the valid range.
559 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
562 Common RejectNegative Joined UInteger Warning
563 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
565 Wunsafe-loop-optimizations
566 Common Var(warn_unsafe_loop_optimizations) Warning
567 Warn if the loop cannot be optimized due to nontrivial assumptions.
570 Common Alias(Wsuggest-attribute=noreturn)
573 Common Var(warn_overflow) Init(1) Warning
574 Warn about overflow in arithmetic expressions
577 Common Var(warn_packed) Warning
578 Warn when the packed attribute has no effect on struct layout
581 Common Var(warn_padded) Warning
582 Warn when padding is required to align structure members
585 Common Var(pedantic) Warning
586 Issue warnings needed for strict compliance to the standard
589 Common Var(warn_shadow) Warning
590 Warn when one local variable shadows another
593 Common Var(warn_stack_protect) Warning
594 Warn when not issuing stack smashing protection for some reason
597 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
598 Warn if stack usage might be larger than specified amount
602 Warn about code which might break strict aliasing rules
605 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Init(-1) Warning
606 Warn about code which might break strict aliasing rules
610 Warn about optimizations that assume that signed overflow is undefined
613 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Init(-1) Warning
614 Warn about optimizations that assume that signed overflow is undefined
616 Wsuggest-attribute=const
617 Common Var(warn_suggest_attribute_const) Warning
618 Warn about functions which might be candidates for __attribute__((const))
620 Wsuggest-attribute=pure
621 Common Var(warn_suggest_attribute_pure) Warning
622 Warn about functions which might be candidates for __attribute__((pure))
624 Wsuggest-attribute=noreturn
625 Common Var(warn_suggest_attribute_noreturn) Warning
626 Warn about functions which might be candidates for __attribute__((noreturn))
629 Common Var(warn_switch) Warning
630 Warn about enumerated switches, with no default, missing a case
633 Common Var(warn_switch_default) Warning
634 Warn about enumerated switches missing a \"default:\" statement
637 Common Var(warn_switch_enum) Warning
638 Warn about all enumerated switches missing a specific case
641 Common Var(warn_system_headers) Warning
642 Do not suppress warnings from system headers
645 Common Var(warn_trampolines) Warning
646 Warn whenever a trampoline is generated
649 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
650 Warn if a comparison is always true or always false due to the limited range of the data type
653 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
654 Warn about uninitialized automatic variables
657 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
658 Warn about maybe uninitialized automatic variables
662 Does nothing. Preserved for backward compatibility.
665 Common Var(warn_unused) Init(0) Warning
666 Enable all -Wunused- warnings
668 Wunused-but-set-parameter
669 Common Var(warn_unused_but_set_parameter) Init(-1) Warning
670 Warn when a function parameter is only set, otherwise unused
672 Wunused-but-set-variable
673 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
674 Warn when a variable is only set, otherwise unused
677 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
678 Warn when a function is unused
681 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
682 Warn when a label is unused
685 Common Var(warn_unused_parameter) Init(-1) Warning
686 Warn when a function parameter is unused
689 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
690 Warn when an expression value is unused
693 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
694 Warn when a variable is unused
697 Common Var(warn_coverage_mismatch) Init(1) Warning
698 Warn in case profiles in -fprofile-use do not match
700 Wvector-operation-performance
701 Common Var(warn_vector_operation_performance) Warning
702 Warn when a vector operation is compiled outside the SIMD
717 Common Separate Var(aux_info_file_name)
718 -aux-info <file> Emit declaration information into <file>
721 Common Joined Alias(aux-info)
724 Common Separate RejectDriver Var(aux_base_name)
727 Common Separate RejectDriver
737 -d<letters> Enable dumps from specific passes of the compiler
740 Common Separate Var(dump_base_name)
741 -dumpbase <file> Set the file basename to be used for dumps
744 Common Separate Var(dump_dir_name)
745 -dumpdir <dir> Set the directory name to be used for dumps
757 Driver Joined Separate
759 ; This option has historically been passed down to the linker by an
760 ; accident of a %{e*} spec, so ensure it continues to be passed down
761 ; as a single option. The supported option for this purpose is
762 ; -rdynamic. See PR 47390.
766 ; The version of the C++ ABI in use. The following values are allowed:
768 ; 0: The version of the ABI believed most conformant with the C++ ABI
769 ; specification. This ABI may change as bugs are discovered and fixed.
770 ; Therefore, 0 will not necessarily indicate the same ABI in different
773 ; 1: The version of the ABI first used in G++ 3.2.
775 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
777 ; 3: The version of the ABI that fixes the missing underscore
778 ; in template non-type arguments of pointer type.
780 ; 4: The version of the ABI that introduces unambiguous mangling of
781 ; vector types. First selectable in G++ 4.5.
783 ; 5: The version of the ABI that ignores attribute const/noreturn
784 ; in function pointer mangling, and corrects mangling of decltype and
785 ; function parameters used in other parameters and the return type.
786 ; First selectable in G++ 4.6.
788 ; 6: The version of the ABI that doesn't promote scoped enums to int and
789 ; changes the mangling of template argument packs, const/static_cast,
790 ; prefix ++ and --, and a class scope function used as a template
792 ; First selectable in G++ 4.7.
794 ; 7: The version of the ABI that treats nullptr_t as a builtin type.
795 ; First selectable in G++ 4.8.
796 ; Additional positive integers will be assigned as new versions of
797 ; the ABI become the default version of the ABI.
799 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
802 Common Report Var(align_functions,0) Optimization UInteger
803 Align the start of functions
806 Common RejectNegative Joined UInteger Var(align_functions)
809 Common Report Var(align_jumps,0) Optimization UInteger
810 Align labels which are only reached by jumping
813 Common RejectNegative Joined UInteger Var(align_jumps)
816 Common Report Var(align_labels,0) Optimization UInteger
820 Common RejectNegative Joined UInteger Var(align_labels)
823 Common Report Var(align_loops,0) Optimization UInteger
824 Align the start of loops
827 Common RejectNegative Joined UInteger Var(align_loops)
831 Does nothing. Preserved for backward compatibility.
835 Does nothing. Preserved for backward compatibility.
837 fargument-noalias-global
839 Does nothing. Preserved for backward compatibility.
841 fargument-noalias-anything
843 Does nothing. Preserved for backward compatibility.
845 fasynchronous-unwind-tables
846 Common Report Var(flag_asynchronous_unwind_tables) Optimization
847 Generate unwind tables that are exact at each instruction boundary
850 Common Report Var(flag_auto_inc_dec) Init(1)
851 Generate auto-inc/dec instructions
853 ; -fcheck-bounds causes gcc to generate array bounds checks.
854 ; For C, C++ and ObjC: defaults off.
855 ; For Java: defaults to on.
856 ; For Fortran: defaults to off.
858 Common Report Var(flag_bounds_check)
859 Generate code to check bounds before indexing arrays
862 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
863 Replace add, compare, branch with branch on count register
865 fbranch-probabilities
866 Common Report Var(flag_branch_probabilities) Optimization
867 Use profiling information for branch probabilities
869 fbranch-target-load-optimize
870 Common Report Var(flag_branch_target_load_optimize) Optimization
871 Perform branch target load optimization before prologue / epilogue threading
873 fbranch-target-load-optimize2
874 Common Report Var(flag_branch_target_load_optimize2) Optimization
875 Perform branch target load optimization after prologue / epilogue threading
878 Common Report Var(flag_btr_bb_exclusive) Optimization
879 Restrict target load migration not to re-use registers in any basic block
882 Common Joined RejectNegative Var(common_deferred_options) Defer
883 -fcall-saved-<register> Mark <register> as being preserved across functions
886 Common Joined RejectNegative Var(common_deferred_options) Defer
887 -fcall-used-<register> Mark <register> as being corrupted by function calls
889 ; Nonzero for -fcaller-saves: allocate values in regs that need to
890 ; be saved across function calls, if that produces overall better code.
891 ; Optional now, so people can test it.
893 Common Report Var(flag_caller_saves) Optimization
894 Save registers around function calls
897 Common Report Var(flag_check_data_deps)
898 Compare the results of several data dependence analyzers.
900 fcombine-stack-adjustments
901 Common Report Var(flag_combine_stack_adjustments) Optimization
902 Looks for opportunities to reduce stack adjustments and stack references.
905 Common Report Var(flag_no_common,0) Optimization
906 Do not put uninitialized globals in the common section
910 ; Converted by the driver to -fcompare-debug= options.
913 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
914 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
916 fcompare-debug-second
917 Common Driver RejectNegative Var(flag_compare_debug)
918 Run only the second compilation of -fcompare-debug
921 Common Report Var(flag_compare_elim_after_reload) Optimization
922 Perform comparison elimination after register allocation has finished
925 Common Var(flag_conserve_stack) Optimization
926 Do not perform optimizations increasing noticeably stack usage
929 Common Report Var(flag_cprop_registers) Optimization
930 Perform a register copy-propagation optimization pass
933 Common Report Var(flag_crossjumping) Optimization
934 Perform cross-jumping optimization
937 Common Report Var(flag_cse_follow_jumps) Optimization
938 When running CSE, follow jumps to their targets
942 Does nothing. Preserved for backward compatibility.
945 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
946 Omit range reduction step when performing complex division
949 Common Report Var(flag_cx_fortran_rules) Optimization
950 Complex multiplication and division follow Fortran rules
953 Common Report Var(flag_data_sections) Optimization
954 Place data items into their own section
957 Common Report Var(common_deferred_options) Defer
958 List all available debugging counters with their limits and counts.
961 Common RejectNegative Joined Var(common_deferred_options) Defer
962 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
965 Common Joined RejectNegative Var(common_deferred_options) Defer
966 Map one directory name to another in debug information
969 Common Report Var(flag_debug_types_section) Init(0)
970 Output .debug_types section when using DWARF v4 debuginfo.
972 ; Nonzero for -fdefer-pop: don't pop args after each function call
973 ; instead save them up to pop many calls' args with one insns.
975 Common Report Var(flag_defer_pop) Optimization
976 Defer popping functions args from stack until later
979 Common Report Var(flag_delayed_branch) Optimization
980 Attempt to fill delay slots of branch instructions
982 fdelete-null-pointer-checks
983 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
984 Delete useless null pointer checks
987 Common Report Var(flag_devirtualize) Optimization
988 Try to convert virtual calls to direct ones.
990 fdiagnostics-show-location=
991 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
992 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
994 ; Required for these enum values.
999 Name(diagnostic_prefixing_rule) Type(int)
1002 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1005 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1007 fdiagnostics-show-caret
1008 Common Var(flag_diagnostics_show_caret) Init(1)
1009 Show the source line with a caret indicating the column
1011 fdiagnostics-show-option
1012 Common Var(flag_diagnostics_show_option) Init(1)
1013 Amend appropriate diagnostic messages with the command line option that controls them
1016 Common Joined RejectNegative Var(common_deferred_options) Defer
1017 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1020 Common Joined RejectNegative Var(common_deferred_options) Defer
1021 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1024 Common Joined RejectNegative Var(common_deferred_options) Defer
1025 -fdump-<type> Dump various compiler internals to a file
1028 Driver RejectNegative
1031 Common RejectNegative Joined Var(flag_dump_final_insns)
1032 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1035 Common RejectNegative Joined Var(flag_dump_go_spec)
1036 -fdump-go-spec=filename Write all declarations to file as Go code
1039 Common Report Var(flag_dump_noaddr)
1040 Suppress output of addresses in debugging dumps
1043 Common Var(flag_dump_passes) Init(0)
1044 Dump optimization passes
1047 Common Report Var(flag_dump_unnumbered)
1048 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1050 fdump-unnumbered-links
1051 Common Report Var(flag_dump_unnumbered_links)
1052 Suppress output of previous and next insn numbers in debugging dumps
1055 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1056 Enable CFI tables via GAS assembler directives.
1059 Common Report Var(flag_early_inlining) Init(1) Optimization
1060 Perform early inlining
1062 feliminate-dwarf2-dups
1063 Common Report Var(flag_eliminate_dwarf2_dups)
1064 Perform DWARF2 duplicate elimination
1067 Common Report Var(flag_ipa_sra) Init(0) Optimization
1068 Perform interprocedural reduction of aggregates
1070 feliminate-unused-debug-symbols
1071 Common Report Var(flag_debug_only_used_symbols)
1072 Perform unused type elimination in debug info
1074 feliminate-unused-debug-types
1075 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1076 Perform unused type elimination in debug info
1078 femit-class-debug-always
1079 Common Report Var(flag_emit_class_debug_always) Init(0)
1080 Do not suppress C++ class debug information.
1083 Common Report Var(flag_exceptions) Optimization
1084 Enable exception handling
1086 fexpensive-optimizations
1087 Common Report Var(flag_expensive_optimizations) Optimization
1088 Perform a number of minor, expensive optimizations
1091 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1092 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1095 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1098 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1101 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1107 Common Var(flag_fat_lto_objects) Init(1)
1108 Output lto objects containing both the intermediate language and binary output.
1111 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1112 Assume no NaNs or infinities are generated
1115 Common Joined RejectNegative Var(common_deferred_options) Defer
1116 -ffixed-<register> Mark <register> as being unavailable to the compiler
1119 Common Report Var(flag_float_store) Optimization
1120 Don't allocate floats and doubles in extended-precision registers
1124 Does nothing. Preserved for backward compatibility.
1127 Common Report Var(flag_forward_propagate) Optimization
1128 Perform a forward propagation pass on RTL
1131 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1132 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1135 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1138 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1140 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1142 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1145 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1147 ; Nonzero means don't put addresses of constant functions in registers.
1148 ; Used for compiling the Unix kernel, where strange substitutions are
1149 ; done on the assembly output.
1151 Common Report Var(flag_no_function_cse,0)
1152 Allow function addresses to be held in registers
1155 Common Report Var(flag_function_sections)
1156 Place each function into its own section
1159 Common Report Var(flag_gcse) Optimization
1160 Perform global common subexpression elimination
1163 Common Report Var(flag_gcse_lm) Init(1) Optimization
1164 Perform enhanced load motion during global common subexpression elimination
1167 Common Report Var(flag_gcse_sm) Init(0) Optimization
1168 Perform store motion after global common subexpression elimination
1171 Common Report Var(flag_gcse_las) Init(0) Optimization
1172 Perform redundant load after store elimination in global common subexpression
1176 Common Report Var(flag_gcse_after_reload) Optimization
1177 Perform global common subexpression elimination after register allocation
1180 ; This option is not documented yet as its semantics will change.
1182 Common Report Var(flag_graphite)
1183 Enable in and out of Graphite representation
1186 Common Report Var(flag_graphite_identity) Optimization
1187 Enable Graphite Identity transformation
1189 floop-parallelize-all
1190 Common Report Var(flag_loop_parallelize_all) Optimization
1191 Mark all loops as parallel
1194 Common Report Var(flag_loop_strip_mine) Optimization
1195 Enable Loop Strip Mining transformation
1198 Common Report Var(flag_loop_interchange) Optimization
1199 Enable Loop Interchange transformation
1202 Common Report Var(flag_loop_block) Optimization
1203 Enable Loop Blocking transformation
1206 Common Report Var(flag_tm)
1207 Enable support for GNU transactional memory
1211 Does nothing. Preserved for backward compatibility.
1213 fstrict-volatile-bitfields
1214 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1215 Force bitfield accesses to match their type width
1217 fguess-branch-probability
1218 Common Report Var(flag_guess_branch_prob) Optimization
1219 Enable guessing of branch probabilities
1221 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1222 ; Generate position-independent code for executables if possible
1223 ; On SVR4 targets, it also controls whether or not to emit a
1224 ; string identifying the compiler.
1226 Common Report Var(flag_no_ident,0)
1227 Process #ident directives
1230 Common Report Var(flag_if_conversion) Optimization
1231 Perform conversion of conditional jumps to branchless equivalents
1234 Common Report Var(flag_if_conversion2) Optimization
1235 Perform conversion of conditional jumps to conditional execution
1237 ftree-loop-if-convert
1238 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1239 Convert conditional jumps in innermost loops to branchless equivalents
1241 ftree-loop-if-convert-stores
1242 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1243 Also if-convert conditional jumps containing memory writes
1245 ; -finhibit-size-directive inhibits output of .size for ELF.
1246 ; This is used only for compiling crtstuff.c,
1247 ; and it may be extended to other effects
1248 ; needed for crtstuff.c on other systems.
1249 finhibit-size-directive
1250 Common Report Var(flag_inhibit_size_directive)
1251 Do not generate .size directives
1254 Common Report Var(flag_indirect_inlining)
1255 Perform indirect inlining
1257 ; General flag to enable inlining. Specifying -fno-inline will disable
1258 ; all inlining apart from always-inline functions.
1260 Common Report Var(flag_no_inline,0) Init(0)
1261 Enable inlining of function declared \"inline\", disabling disables all inlining
1263 finline-small-functions
1264 Common Report Var(flag_inline_small_functions) Optimization
1265 Integrate functions into their callers when code size is known not to grow
1268 Common Report Var(flag_inline_functions) Optimization
1269 Integrate functions not declared \"inline\" into their callers when profitable
1271 finline-functions-called-once
1272 Common Report Var(flag_inline_functions_called_once) Optimization
1273 Integrate functions only required by their single caller
1276 Common RejectNegative Joined Alias(finline-limit=)
1279 Common RejectNegative Joined UInteger
1280 -finline-limit=<number> Limit the size of inlined functions to <number>
1283 Common Report Var(flag_inline_atomics) Init(1) Optimization
1284 Inline __atomic operations when a lock free instruction sequence is available.
1286 finstrument-functions
1287 Common Report Var(flag_instrument_function_entry_exit)
1288 Instrument function entry and exit with profiling calls
1290 finstrument-functions-exclude-function-list=
1291 Common RejectNegative Joined
1292 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1294 finstrument-functions-exclude-file-list=
1295 Common RejectNegative Joined
1296 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1299 Common Report Var(flag_ipa_cp) Optimization
1300 Perform Interprocedural constant propagation
1303 Common Report Var(flag_ipa_cp_clone) Optimization
1304 Perform cloning to make Interprocedural constant propagation stronger
1307 Common Report Var(flag_ipa_profile) Init(0) Optimization
1308 Perform interprocedural profile propagation
1311 Common Report Var(flag_ipa_pta) Init(0) Optimization
1312 Perform interprocedural points-to analysis
1315 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1316 Discover pure and const functions
1319 Common Report Var(flag_ipa_reference) Init(0) Optimization
1320 Discover readonly and non addressable static variables
1323 Common Report Var(flag_ipa_matrix_reorg) Optimization
1324 Perform matrix layout flattening and transposing based
1325 on profiling information.
1329 Does nothing. Preserved for backward compatibility.
1332 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1333 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1336 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1339 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1342 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1345 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1346 -fira-region=[one|all|mixed] Set regions for IRA
1349 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1352 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1355 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1358 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1361 Common Report Var(flag_ira_loop_pressure)
1362 Use IRA based register pressure calculation
1363 in RTL loop optimizations.
1365 fira-share-save-slots
1366 Common Report Var(flag_ira_share_save_slots) Init(1)
1367 Share slots for saving different hard registers.
1369 fira-share-spill-slots
1370 Common Report Var(flag_ira_share_spill_slots) Init(1)
1371 Share stack slots for spilled pseudo-registers.
1374 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1375 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1378 Common Report Var(flag_ivopts) Init(1) Optimization
1379 Optimize induction variables on trees
1382 Common Var(flag_jump_tables) Init(1) Optimization
1383 Use jump tables for sufficiently large switch statements
1385 fkeep-inline-functions
1386 Common Report Var(flag_keep_inline_functions)
1387 Generate code for functions even if they are fully inlined
1390 Common Report Var(flag_keep_static_consts) Init(1)
1391 Emit static const variables even if they are not used
1394 Common Report Var(flag_leading_underscore) Init(-1)
1395 Give external symbols a leading underscore
1399 Does nothing. Preserved for backward compatibility.
1403 Enable link-time optimization.
1406 Common RejectNegative Joined Var(flag_lto)
1407 Link-time optimization with number of parallel jobs or jobserver.
1410 Common Var(flag_lto_partition_1to1)
1411 Partition functions and vars at linktime based on object files they originate from
1413 flto-partition=balanced
1414 Common Var(flag_lto_partition_balanced)
1415 Partition functions and vars at linktime into approximately same sized buckets
1418 Common Var(flag_lto_partition_none)
1419 Disable partioning and streaming
1421 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1422 flto-compression-level=
1423 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1424 -flto-compression-level=<number> Use zlib compression level <number> for IL
1427 Common Report Var(flag_lto_report) Init(0)
1428 Report various link-time optimization statistics
1431 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1432 Set errno after built-in math functions
1435 Common Joined RejectNegative UInteger Var(flag_max_errors)
1436 -fmax-errors=<number> Maximum number of errors to report
1439 Common Report Var(mem_report)
1440 Report on permanent memory allocation
1442 ; This will attempt to merge constant section constants, if 1 only
1443 ; string constants and constants from constant pool, if 2 also constant
1445 fmerge-all-constants
1446 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1447 Attempt to merge identical constants and constant variables
1450 Common Report Var(flag_merge_constants,1) Optimization
1451 Attempt to merge identical constants across compilation units
1453 fmerge-debug-strings
1454 Common Report Var(flag_merge_debug_strings) Init(1)
1455 Attempt to merge identical debug strings across compilation units
1458 Common RejectNegative Joined UInteger
1459 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1462 Common Report Var(flag_modulo_sched) Optimization
1463 Perform SMS based modulo scheduling before the first scheduling pass
1465 fmodulo-sched-allow-regmoves
1466 Common Report Var(flag_modulo_sched_allow_regmoves)
1467 Perform SMS based modulo scheduling with register moves allowed
1469 fmove-loop-invariants
1470 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1471 Move loop invariant computations out of loops
1474 Common Var(flag_dce) Init(1) Optimization
1475 Use the RTL dead code elimination pass
1478 Common Var(flag_dse) Init(1) Optimization
1479 Use the RTL dead store elimination pass
1481 freschedule-modulo-scheduled-loops
1482 Common Report Var(flag_resched_modulo_sched) Optimization
1483 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1485 fnon-call-exceptions
1486 Common Report Var(flag_non_call_exceptions) Optimization
1487 Support synchronous non-call exceptions
1490 Common Report Var(flag_omit_frame_pointer) Optimization
1491 When possible do not generate stack frames
1493 foptimize-register-move
1494 Common Report Var(flag_regmove) Optimization
1495 Do the full register move optimization pass
1497 foptimize-sibling-calls
1498 Common Report Var(flag_optimize_sibling_calls) Optimization
1499 Optimize sibling and tail recursive calls
1502 Common Report Var(flag_partial_inlining)
1503 Perform partial inlining
1506 Common Report Var(pre_ipa_mem_report)
1507 Report on memory allocation before interprocedural optimization
1509 fpost-ipa-mem-report
1510 Common Report Var(post_ipa_mem_report)
1511 Report on memory allocation before interprocedural optimization
1514 Common Report Var(flag_pack_struct) Optimization
1515 Pack structure members together without holes
1518 Common RejectNegative Joined UInteger Optimization
1519 -fpack-struct=<number> Set initial maximum structure member alignment
1522 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1523 Return small aggregates in memory, not registers
1526 Common Report Var(flag_peel_loops) Optimization
1527 Perform loop peeling
1530 Common Report Var(flag_no_peephole,0) Optimization
1531 Enable machine specific peephole optimizations
1534 Common Report Var(flag_peephole2) Optimization
1535 Enable an RTL peephole pass before sched2
1538 Common Report Var(flag_pic,2)
1539 Generate position-independent code if possible (large mode)
1542 Common Report Var(flag_pie,2)
1543 Generate position-independent code for executables if possible (large mode)
1546 Common Report Var(flag_pic,1)
1547 Generate position-independent code if possible (small mode)
1550 Common Report Var(flag_pie,1)
1551 Generate position-independent code for executables if possible (small mode)
1554 Common Joined RejectNegative Var(common_deferred_options) Defer
1555 Specify a plugin to load
1558 Common Joined RejectNegative Var(common_deferred_options) Defer
1559 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1561 fpredictive-commoning
1562 Common Report Var(flag_predictive_commoning) Optimization
1563 Run predictive commoning optimization.
1565 fprefetch-loop-arrays
1566 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1567 Generate prefetch instructions, if available, for arrays in loops
1570 Common Report Var(profile_flag)
1571 Enable basic program profiling code
1574 Common Report Var(profile_arc_flag)
1575 Insert arc-based program profiling code
1578 Common Joined RejectNegative Var(profile_data_prefix)
1579 Set the top-level directory for storing the profile data.
1580 The default is 'pwd'.
1583 Common Report Var(flag_profile_correction)
1584 Enable correction of flow inconsistent profile data input
1588 Enable common options for generating profile info for profile feedback directed optimizations
1591 Common Joined RejectNegative
1592 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1595 Common Var(flag_profile_use)
1596 Enable common options for performing profile feedback directed optimizations
1599 Common Joined RejectNegative
1600 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1603 Common Report Var(flag_profile_values)
1604 Insert code to profile values of expressions
1607 Common Var(common_deferred_options) Defer
1610 Common Joined RejectNegative Var(common_deferred_options) Defer
1611 -frandom-seed=<string> Make compile reproducible using <string>
1613 ; This switch causes the command line that was used to create an
1614 ; object file to be recorded into the object file. The exact format
1615 ; of this recording is target and binary file format dependent.
1616 ; It is related to the -fverbose-asm switch, but that switch only
1617 ; records information in the assembler output file as comments, so
1618 ; they never reach the object file.
1619 frecord-gcc-switches
1620 Common Report Var(flag_record_gcc_switches)
1621 Record gcc command line switches in the object file.
1624 Common Report Var(flag_pcc_struct_return,0) Optimization
1625 Return small aggregates in registers
1628 Common Report Var(flag_regmove) Optimization
1629 Enables a register move optimization
1632 Common Report Var(flag_rename_registers) Init(2) Optimization
1633 Perform a register renaming optimization pass
1636 Common Report Var(flag_reorder_blocks) Optimization
1637 Reorder basic blocks to improve code placement
1639 freorder-blocks-and-partition
1640 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1641 Reorder basic blocks and partition into hot and cold sections
1644 Common Report Var(flag_reorder_functions) Optimization
1645 Reorder functions to improve code placement
1647 frerun-cse-after-loop
1648 Common Report Var(flag_rerun_cse_after_loop) Optimization
1649 Add a common subexpression elimination pass after loop optimizations
1653 Does nothing. Preserved for backward compatibility.
1656 Common Report Var(flag_rounding_math) Optimization SetByCombined
1657 Disable optimizations that assume default FP rounding behavior
1660 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1661 Enable scheduling across basic blocks
1664 Common Report Var(flag_sched_pressure) Init(0) Optimization
1665 Enable register pressure sensitive insn scheduling
1668 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1669 Allow speculative motion of non-loads
1672 Common Report Var(flag_schedule_speculative_load) Optimization
1673 Allow speculative motion of some loads
1675 fsched-spec-load-dangerous
1676 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1677 Allow speculative motion of more loads
1680 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1681 -fsched-verbose=<number> Set the verbosity level of the scheduler
1683 fsched2-use-superblocks
1684 Common Report Var(flag_sched2_use_superblocks) Optimization
1685 If scheduling post reload, do superblock scheduling
1689 Does nothing. Preserved for backward compatibility.
1692 Common Report Var(flag_schedule_insns) Optimization
1693 Reschedule instructions before register allocation
1696 Common Report Var(flag_schedule_insns_after_reload) Optimization
1697 Reschedule instructions after register allocation
1699 ; This flag should be on when a target implements non-trivial
1700 ; scheduling hooks, maybe saving some information for its own sake.
1701 ; On IA64, for example, this is used for correct bundling.
1702 fselective-scheduling
1703 Common Report Var(flag_selective_scheduling) Optimization
1704 Schedule instructions using selective scheduling algorithm
1706 fselective-scheduling2
1707 Common Report Var(flag_selective_scheduling2) Optimization
1708 Run selective scheduling after reload
1710 fsel-sched-pipelining
1711 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1712 Perform software pipelining of inner loops during selective scheduling
1714 fsel-sched-pipelining-outer-loops
1715 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1716 Perform software pipelining of outer loops during selective scheduling
1718 fsel-sched-reschedule-pipelined
1719 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1720 Reschedule pipelined regions without pipelining
1722 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1723 ; of stalled insns into the ready list.
1724 fsched-stalled-insns
1725 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1726 Allow premature scheduling of queued insns
1728 fsched-stalled-insns=
1729 Common RejectNegative Joined UInteger
1730 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1732 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1733 ; be examined for a dependency on a stalled insn that is candidate for
1734 ; premature removal from the queue of stalled insns into the ready list (has
1735 ; an effect only if the flag 'sched_stalled_insns' is set).
1736 fsched-stalled-insns-dep
1737 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1738 Set dependence distance checking in premature scheduling of queued insns
1740 fsched-stalled-insns-dep=
1741 Common RejectNegative Joined UInteger
1742 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1744 fsched-group-heuristic
1745 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1746 Enable the group heuristic in the scheduler
1748 fsched-critical-path-heuristic
1749 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1750 Enable the critical path heuristic in the scheduler
1752 fsched-spec-insn-heuristic
1753 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1754 Enable the speculative instruction heuristic in the scheduler
1756 fsched-rank-heuristic
1757 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1758 Enable the rank heuristic in the scheduler
1760 fsched-last-insn-heuristic
1761 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1762 Enable the last instruction heuristic in the scheduler
1764 fsched-dep-count-heuristic
1765 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1766 Enable the dependent count heuristic in the scheduler
1769 Common Report Var(flag_section_anchors) Optimization
1770 Access data in the same section from shared anchor points
1774 Does nothing. Preserved for backward compatibility.
1778 Does nothing. Preserved for backward compatibility.
1781 Common Report Var(flag_ree) Init(0)
1782 Turn on Redundant Extensions Elimination pass.
1785 Common Report Var(flag_show_column) Init(1)
1786 Show column numbers in diagnostics, when available. Default on
1789 Common Report Var(flag_shrink_wrap) Optimization
1790 Emit function prologues only before parts of the function that need it,
1791 rather than at the top of the function.
1794 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1795 Disable optimizations observable by IEEE signaling NaNs
1798 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1799 Disable floating point optimizations that ignore the IEEE signedness of zero
1801 fsingle-precision-constant
1802 Common Report Var(flag_single_precision_constant) Optimization
1803 Convert floating point constants to single precision constants
1805 fsplit-ivs-in-unroller
1806 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1807 Split lifetimes of induction variables when loops are unrolled
1810 Common Report Var(flag_split_stack) Init(-1)
1811 Generate discontiguous stack frames
1814 Common Report Var(flag_split_wide_types) Optimization
1815 Split wide types into independent registers
1817 fvariable-expansion-in-unroller
1818 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1819 Apply variable expansion when loops are unrolled
1822 Common Report RejectNegative Joined
1823 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1826 Common Alias(fstack-check=, specific, no)
1827 Insert stack checking code into the program. Same as -fstack-check=specific
1830 Common Var(common_deferred_options) Defer
1832 fstack-limit-register=
1833 Common RejectNegative Joined Var(common_deferred_options) Defer
1834 -fstack-limit-register=<register> Trap if the stack goes past <register>
1836 fstack-limit-symbol=
1837 Common RejectNegative Joined Var(common_deferred_options) Defer
1838 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1841 Common Report Var(flag_stack_protect, 1)
1842 Use propolice as a stack protection method
1844 fstack-protector-all
1845 Common Report RejectNegative Var(flag_stack_protect, 2)
1846 Use a stack protection method for every function
1849 Common RejectNegative Var(flag_stack_usage)
1850 Output stack usage information on a per-function basis
1854 Does nothing. Preserved for backward compatibility.
1856 ; Nonzero if we should do (language-dependent) alias analysis.
1857 ; Typically, this analysis will assume that expressions of certain
1858 ; types do not alias expressions of certain other types. Only used
1859 ; if alias analysis (in general) is enabled.
1861 Common Report Var(flag_strict_aliasing) Optimization
1862 Assume strict aliasing rules apply
1865 Common Report Var(flag_strict_overflow)
1866 Treat signed overflow as undefined
1869 Common Report Var(flag_sync_libcalls) Init(1)
1870 Implement __atomic operations via libcalls to legacy __sync functions
1873 Common Report Var(flag_syntax_only)
1874 Check for syntax errors, then stop
1877 Common Report Var(flag_test_coverage)
1878 Create data files needed by \"gcov\"
1881 Common Report Var(flag_thread_jumps) Optimization
1882 Perform jump threading optimizations
1885 Common Report Var(time_report)
1886 Report the time taken by each compiler pass
1889 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1890 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1893 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1896 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1899 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1902 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1905 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1908 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1909 Reorder top level functions, variables, and asms
1912 Common Report Var(flag_tracer)
1913 Perform superblock formation via tail duplication
1915 ; Zero means that floating-point math operations cannot generate a
1916 ; (user-visible) trap. This is the case, for example, in nonstop
1917 ; IEEE 754 arithmetic.
1919 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1920 Assume floating-point operations can trap
1923 Common Report Var(flag_trapv) Optimization
1924 Trap for signed overflow in addition, subtraction and multiplication
1927 Common Report Var(flag_tree_ccp) Optimization
1928 Enable SSA-CCP optimization on trees
1931 Common Report Var(flag_tree_bit_ccp) Optimization
1932 Enable SSA-BIT-CCP optimization on trees
1936 Does nothing. Preserved for backward compatibility.
1939 Common Report Var(flag_tree_ch) Optimization
1940 Enable loop header copying on trees
1943 Common Report Var(flag_tree_copyrename) Optimization
1944 Replace SSA temporaries with better names in copies
1947 Common Report Var(flag_tree_copy_prop) Optimization
1948 Enable copy propagation on trees
1950 ftree-store-copy-prop
1952 Does nothing. Preserved for backward compatibility.
1955 Common Report Var(flag_tree_cselim) Init(2) Optimization
1956 Transform condition stores into unconditional ones
1958 ftree-switch-conversion
1959 Common Report Var(flag_tree_switch_conversion) Optimization
1960 Perform conversions of switch initializations.
1963 Common Report Var(flag_tree_dce) Optimization
1964 Enable SSA dead code elimination optimization on trees
1966 ftree-dominator-opts
1967 Common Report Var(flag_tree_dom) Optimization
1968 Enable dominator optimizations
1971 Common Report Var(flag_tree_tail_merge) Optimization
1972 Enable tail merging on trees
1975 Common Report Var(flag_tree_dse) Optimization
1976 Enable dead store elimination
1979 Common Report Var(flag_tree_forwprop) Init(1) Optimization
1980 Enable forward propagation on trees
1983 Common Report Var(flag_tree_fre) Optimization
1984 Enable Full Redundancy Elimination (FRE) on trees
1987 Common Report Var(flag_optimize_strlen) Optimization
1988 Enable string length optimizations on trees
1990 ftree-loop-distribution
1991 Common Report Var(flag_tree_loop_distribution) Optimization
1992 Enable loop distribution on trees
1994 ftree-loop-distribute-patterns
1995 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
1996 Enable loop distribution for patterns transformed into a library call
1999 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2000 Enable loop invariant motion on trees
2003 Common Alias(floop-interchange)
2004 Enable loop interchange transforms. Same as -floop-interchange
2007 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2008 Create canonical induction variables in loops
2011 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2012 Enable loop optimizations on tree level
2014 ftree-parallelize-loops=
2015 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2016 Enable automatic parallelization of loops
2019 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2020 Enable hoisting loads from conditional pointers.
2023 Common Report Var(flag_tree_pre) Optimization
2024 Enable SSA-PRE optimization on trees
2027 Common Report Var(flag_tree_partial_pre) Optimization
2028 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2031 Common Report Var(flag_tree_pta) Init(1) Optimization
2032 Perform function-local points-to analysis on trees.
2035 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2036 Enable reassociation on tree level
2040 Does nothing. Preserved for backward compatibility.
2043 Common Report Var(flag_tree_sink) Optimization
2044 Enable SSA code sinking on trees
2047 Common Report Var(flag_tree_sra) Optimization
2048 Perform scalar replacement of aggregates
2051 Common Report Var(flag_tree_ter) Optimization
2052 Replace temporary expressions in the SSA->normal pass
2055 Common Report Var(flag_tree_live_range_split) Optimization
2056 Perform live range splitting during the SSA->normal pass
2059 Common Report Var(flag_tree_vrp) Init(0) Optimization
2060 Perform Value Range Propagation on trees
2063 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2064 Compile whole compilation unit at a time
2067 Common Report Var(flag_unroll_loops) Optimization
2068 Perform loop unrolling when iteration count is known
2071 Common Report Var(flag_unroll_all_loops) Optimization
2072 Perform loop unrolling for all loops
2074 ; Nonzero means that loop optimizer may assume that the induction variables
2075 ; that control loops do not overflow and that the loops with nontrivial
2076 ; exit condition are not infinite
2077 funsafe-loop-optimizations
2078 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2079 Allow loop optimizations to assume that the loops behave in normal way
2082 Common Report Var(flag_associative_math) SetByCombined
2083 Allow optimization for floating-point arithmetic which may change the
2084 result of the operation due to rounding.
2087 Common Report Var(flag_reciprocal_math) SetByCombined
2088 Same as -fassociative-math for expressions which include division.
2090 ; Nonzero means that unsafe floating-point math optimizations are allowed
2091 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2092 ; are allowed to assume that their arguments and results are "normal"
2093 ; (e.g., nonnegative for SQRT).
2094 funsafe-math-optimizations
2095 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2096 Allow math optimizations that may violate IEEE or ISO standards
2099 Common Report Var(flag_unswitch_loops) Optimization
2100 Perform loop unswitching
2103 Common Report Var(flag_unwind_tables) Optimization
2104 Just generate unwind tables for exception handling
2109 ; Positive if we should track variables, negative if we should run
2110 ; the var-tracking pass only to discard debug annotations, zero if
2111 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2112 ; will be set according to optimize, debug_info_level and debug_hooks
2113 ; in process_options ().
2115 Common Report Var(flag_var_tracking) Init(2) Optimization
2116 Perform variable tracking
2118 ; Positive if we should track variables at assignments, negative if
2119 ; we should run the var-tracking pass only to discard debug
2120 ; annotations. When flag_var_tracking_assignments ==
2121 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2122 fvar-tracking-assignments
2123 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2124 Perform variable tracking by annotating assignments
2126 ; Nonzero if we should toggle flag_var_tracking_assignments after
2127 ; processing options and computing its default. */
2128 fvar-tracking-assignments-toggle
2129 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2130 Toggle -fvar-tracking-assignments
2132 fvar-tracking-uninit
2133 Common Report Var(flag_var_tracking_uninit) Optimization
2134 Perform variable tracking and also tag variables that are uninitialized
2137 Common Report Var(flag_tree_vectorize) Optimization
2138 Enable loop vectorization on trees
2141 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2142 Enable basic block vectorization (SLP) on trees
2145 Common Report Var(flag_vect_cost_model) Optimization
2146 Enable use of cost model in vectorization
2148 ftree-vect-loop-version
2149 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2150 Enable loop versioning when doing loop vectorization on trees
2152 ftree-vectorizer-verbose=
2153 Common RejectNegative Joined UInteger
2154 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
2157 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2158 Enable copy propagation of scalar-evolution information.
2160 ; -fverbose-asm causes extra commentary information to be produced in
2161 ; the generated assembly code (to make it more readable). This option
2162 ; is generally only of use to those who actually need to read the
2163 ; generated assembly code (perhaps while debugging the compiler itself).
2164 ; -fno-verbose-asm, the default, causes the extra information
2165 ; to not be added and is useful when comparing two assembler files.
2167 Common Report Var(flag_verbose_asm)
2168 Add extra commentary to assembler output
2171 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2172 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2175 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2178 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2181 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2184 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2187 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2190 Common Report Var(flag_value_profile_transformations) Optimization
2191 Use expression value profiles in optimizations
2194 Common Report Var(flag_web) Init(2) Optimization
2195 Construct webs and split unrelated uses of single variable
2197 ftree-builtin-call-dce
2198 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2199 Enable conditional dead code elimination for builtin calls
2202 Common Report Var(flag_whole_program) Init(0) Optimization
2203 Perform whole program optimizations
2206 Common Report Var(flag_wrapv) Optimization
2207 Assume signed arithmetic overflow wraps around
2209 fzero-initialized-in-bss
2210 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2211 Put zero initialized data in the bss section
2214 Common JoinedOrMissing
2215 Generate debug information in default format
2218 Common JoinedOrMissing Negative(gdwarf-)
2219 Generate debug information in COFF format
2222 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2223 Generate debug information in DWARF v2 (or later) format
2226 Common JoinedOrMissing
2227 Generate debug information in default extended format
2229 gno-record-gcc-switches
2230 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2231 Don't record gcc command line switches in DWARF DW_AT_producer.
2233 grecord-gcc-switches
2234 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2235 Record gcc command line switches in DWARF DW_AT_producer.
2238 Common JoinedOrMissing Negative(gstabs+)
2239 Generate debug information in STABS format
2242 Common JoinedOrMissing Negative(gvms)
2243 Generate debug information in extended STABS format
2246 Common RejectNegative Var(dwarf_strict,0) Init(0)
2247 Emit DWARF additions beyond selected version
2250 Common Report RejectNegative Var(dwarf_strict,1)
2251 Don't emit DWARF additions beyond selected version
2254 Common Report Var(flag_gtoggle)
2255 Toggle debug information generation
2258 Common JoinedOrMissing Negative(gxcoff)
2259 Generate debug information in VMS format
2262 Common JoinedOrMissing Negative(gxcoff+)
2263 Generate debug information in XCOFF format
2266 Common JoinedOrMissing Negative(gcoff)
2267 Generate debug information in extended XCOFF format
2270 Driver Joined Separate
2273 Common Joined Var(plugindir_string) Init(0)
2274 -iplugindir=<dir> Set <dir> to be the default plugin directory
2277 Driver Joined Separate
2282 no-canonical-prefixes
2295 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2296 -o <file> Place output into <file>
2299 Common Var(profile_flag)
2300 Enable function profiling
2303 Driver Var(pass_exit_codes)
2306 Common Alias(Wpedantic)
2309 Common Var(flag_pedantic_errors)
2310 Like -pedantic but issue them as errors
2316 Driver Var(use_pipes)
2319 Driver JoinedOrMissing Var(print_file_name)
2321 print-libgcc-file-name
2324 print-multi-directory
2325 Driver Var(print_multi_directory)
2328 Driver Var(print_multi_lib)
2330 print-multi-os-directory
2331 Driver Var(print_multi_os_directory)
2334 Driver JoinedOrMissing Var(print_prog_name)
2337 Driver Var(print_search_dirs)
2340 Driver Var(print_sysroot)
2342 print-sysroot-headers-suffix
2343 Driver Var(print_sysroot_headers_suffix)
2346 Common Var(quiet_flag) RejectDriver
2347 Do not display functions compiled or elapsed time
2365 Driver Var(report_times)
2368 Driver JoinedOrMissing
2371 Driver Joined Separate
2375 ; C option, but driver must not handle as "-u ndef".
2378 Common Driver Var(verbose_flag)
2379 Enable verbose output
2382 Common Var(version_flag) RejectDriver
2383 Display the compiler's version
2386 Common Var(inhibit_warnings)
2390 Driver Separate Var(wrapper_string)
2393 Driver Joined Separate
2396 Driver RejectNegative Negative(pie)
2397 Create a shared library
2403 Driver Separate Alias(specs=)
2416 ; Documented for Fortran, but always accepted by driver.
2423 ; Documented for Go, but always accepted by driver.
2429 Driver RejectNegative Negative(shared)
2430 Create a position independent executable
2433 Driver Joined Separate
2435 ; This comment is to ensure we retain the blank line above.