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.
38 ; Not used directly to control optimizations, only to save -Ofast
39 ; setting for "optimize" attributes.
43 ; True if this is the lto front end. This is used to disable gimple
44 ; generation and lowering passes that are normally run on the output
45 ; of a front end. These passes must be bypassed for lto since they
46 ; have already been done before the gimple was written.
50 ; 0 means straightforward implementation of complex divide acceptable.
51 ; 1 means wide ranges of inputs must work for complex divide.
52 ; 2 means C99-like requirements for complex multiply and divide.
54 int flag_complex_method = 1
56 ; Nonzero if subexpressions must be evaluated from left-to-right.
58 int flag_evaluation_order = 0
60 ; Language specific warning pass for unused results.
62 bool flag_warn_unused_result = false
67 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
71 ; True to warn about any objects definitions whose size is larger
72 ; than N bytes. Also want about function definitions whose returned
73 ; values are larger than N bytes, where N is 'larger_than_size'.
78 HOST_WIDE_INT larger_than_size
80 ; True to warn about any function whose frame size is larger
83 bool warn_frame_larger_than
86 HOST_WIDE_INT frame_larger_than_size
88 ; Nonzero means we should be saving declaration info into a .X file.
90 int flag_gen_aux_info = 0
92 ; Nonzero if we are compiling code for a shared library, zero for
97 ; These two are really VEC(char_p,heap) *.
100 void *flag_instrument_functions_exclude_functions
103 void *flag_instrument_functions_exclude_files
105 ; Generic structs (e.g. templates not explicitly specialized)
106 ; may not have a compilation unit associated with them, and so
107 ; may need to be treated differently from ordinary structs.
109 ; Structs only handled by reference (indirectly), will also usually
110 ; not need as much debugging information.
113 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
116 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
118 ; True if we should exit after parsing options.
120 bool exit_after_options
122 ; Type(s) of debugging information we are producing (if any). See
123 ; flag-types.h for the definitions of the different possible types of
124 ; debugging information.
126 enum debug_info_type write_symbols = NO_DEBUG
128 ; Level of debugging information we are producing. See flag-types.h
129 ; for the definitions of the different possible levels.
131 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
133 ; Nonzero means use GNU-only extensions in the generated symbolic
134 ; debugging information. Currently, this only has an effect when
135 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
137 bool use_gnu_debug_info_extensions
139 ; Original value of maximum field alignment in bytes, specified via
140 ; -fpack-struct=<value>.
142 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
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)
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
513 Common Var(warn_array_bounds) Warning
514 Warn if an array is accessed out of bounds
517 Common Var(warn_attributes) Init(1) Warning
518 Warn about inappropriate attribute usage
521 Common Var(warn_cast_align) Warning
522 Warn about pointer casts which increase alignment
525 Common Var(warn_cpp) Init(1) Warning
526 Warn when a #warning directive is encountered
528 Wdeprecated-declarations
529 Common Var(warn_deprecated_decl) Init(1) Warning
530 Warn about uses of __attribute__((deprecated)) declarations
532 Wdisabled-optimization
533 Common Var(warn_disabled_optimization) Warning
534 Warn when an optimization pass is disabled
537 Common Var(warnings_are_errors)
538 Treat all warnings as errors
542 Treat specified warning as error
545 Common Var(extra_warnings) Warning
546 Print extra (possibly unwanted) warnings
549 Common Var(flag_fatal_errors)
550 Exit on the first error occurred
553 Common RejectNegative Joined UInteger
554 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
557 Common Var(warn_free_nonheap_object) Init(1) Warning
558 Warn when attempting to free a non-heap object
561 Common Var(warn_inline) Warning
562 Warn when an inlined function cannot be inlined
564 Winvalid-memory-model
565 Common Var(warn_invalid_memory_model) Init(1) Warning
566 Warn when an atomic memory model parameter is known to be outside the valid range.
569 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
572 Common RejectNegative Joined UInteger Warning
573 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
575 Wunsafe-loop-optimizations
576 Common Var(warn_unsafe_loop_optimizations) Warning
577 Warn if the loop cannot be optimized due to nontrivial assumptions.
580 Common Alias(Wsuggest-attribute=noreturn)
583 Common Var(warn_overflow) Init(1) Warning
584 Warn about overflow in arithmetic expressions
587 Common Var(warn_packed) Warning
588 Warn when the packed attribute has no effect on struct layout
591 Common Var(warn_padded) Warning
592 Warn when padding is required to align structure members
595 Common Var(pedantic) Warning
596 Issue warnings needed for strict compliance to the standard
599 Common Var(warn_shadow) Warning
600 Warn when one local variable shadows another
603 Common Var(warn_stack_protect) Warning
604 Warn when not issuing stack smashing protection for some reason
607 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
608 Warn if stack usage might be larger than specified amount
612 Warn about code which might break strict aliasing rules
615 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
616 Warn about code which might break strict aliasing rules
620 Warn about optimizations that assume that signed overflow is undefined
623 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
624 Warn about optimizations that assume that signed overflow is undefined
626 Wsuggest-attribute=const
627 Common Var(warn_suggest_attribute_const) Warning
628 Warn about functions which might be candidates for __attribute__((const))
630 Wsuggest-attribute=pure
631 Common Var(warn_suggest_attribute_pure) Warning
632 Warn about functions which might be candidates for __attribute__((pure))
634 Wsuggest-attribute=noreturn
635 Common Var(warn_suggest_attribute_noreturn) Warning
636 Warn about functions which might be candidates for __attribute__((noreturn))
639 Common Var(warn_system_headers) Warning
640 Do not suppress warnings from system headers
643 Common Var(warn_trampolines) Warning
644 Warn whenever a trampoline is generated
647 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
648 Warn if a comparison is always true or always false due to the limited range of the data type
651 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
652 Warn about uninitialized automatic variables
655 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
656 Warn about maybe uninitialized automatic variables
660 Does nothing. Preserved for backward compatibility.
663 Common Var(warn_unused) Init(0) Warning
664 Enable all -Wunused- warnings
666 Wunused-but-set-parameter
667 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
668 Warn when a function parameter is only set, otherwise unused
670 Wunused-but-set-variable
671 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
672 Warn when a variable is only set, otherwise unused
675 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
676 Warn when a function is unused
679 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
680 Warn when a label is unused
683 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
684 Warn when a function parameter is unused
687 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
688 Warn when an expression value is unused
691 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
692 Warn when a variable is unused
695 Common Var(warn_coverage_mismatch) Init(1) Warning
696 Warn in case profiles in -fprofile-use do not match
698 Wvector-operation-performance
699 Common Var(warn_vector_operation_performance) Warning
700 Warn when a vector operation is compiled outside the SIMD
715 Common Separate Var(aux_info_file_name)
716 -aux-info <file> Emit declaration information into <file>
719 Common Joined Alias(aux-info)
722 Common Separate RejectDriver Var(aux_base_name)
725 Common Separate RejectDriver
735 -d<letters> Enable dumps from specific passes of the compiler
738 Common Separate Var(dump_base_name)
739 -dumpbase <file> Set the file basename to be used for dumps
742 Common Separate Var(dump_dir_name)
743 -dumpdir <dir> Set the directory name to be used for dumps
755 Driver Joined Separate
757 ; This option has historically been passed down to the linker by an
758 ; accident of a %{e*} spec, so ensure it continues to be passed down
759 ; as a single option. The supported option for this purpose is
760 ; -rdynamic. See PR 47390.
764 ; The version of the C++ ABI in use. The following values are allowed:
766 ; 0: The version of the ABI believed most conformant with the C++ ABI
767 ; specification. This ABI may change as bugs are discovered and fixed.
768 ; Therefore, 0 will not necessarily indicate the same ABI in different
771 ; 1: The version of the ABI first used in G++ 3.2.
773 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
775 ; 3: The version of the ABI that fixes the missing underscore
776 ; in template non-type arguments of pointer type.
778 ; 4: The version of the ABI that introduces unambiguous mangling of
779 ; vector types. First selectable in G++ 4.5.
781 ; 5: The version of the ABI that ignores attribute const/noreturn
782 ; in function pointer mangling, and corrects mangling of decltype and
783 ; function parameters used in other parameters and the return type.
784 ; First selectable in G++ 4.6.
786 ; 6: The version of the ABI that doesn't promote scoped enums to int and
787 ; changes the mangling of template argument packs, const/static_cast,
788 ; prefix ++ and --, and a class scope function used as a template
790 ; First selectable in G++ 4.7.
792 ; 7: The version of the ABI that treats nullptr_t as a builtin type.
793 ; First selectable in G++ 4.8.
794 ; Additional positive integers will be assigned as new versions of
795 ; the ABI become the default version of the ABI.
797 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
800 Common Report Var(align_functions,0) Optimization UInteger
801 Align the start of functions
804 Common RejectNegative Joined UInteger Var(align_functions)
807 Common Report Var(align_jumps,0) Optimization UInteger
808 Align labels which are only reached by jumping
811 Common RejectNegative Joined UInteger Var(align_jumps)
814 Common Report Var(align_labels,0) Optimization UInteger
818 Common RejectNegative Joined UInteger Var(align_labels)
821 Common Report Var(align_loops,0) Optimization UInteger
822 Align the start of loops
825 Common RejectNegative Joined UInteger Var(align_loops)
829 Does nothing. Preserved for backward compatibility.
833 Does nothing. Preserved for backward compatibility.
835 fargument-noalias-global
837 Does nothing. Preserved for backward compatibility.
839 fargument-noalias-anything
841 Does nothing. Preserved for backward compatibility.
844 Common Report Var(flag_asan)
845 Enable AddressSanitizer, a memory error detector
847 fasynchronous-unwind-tables
848 Common Report Var(flag_asynchronous_unwind_tables) Optimization
849 Generate unwind tables that are exact at each instruction boundary
852 Common Report Var(flag_auto_inc_dec) Init(1)
853 Generate auto-inc/dec instructions
855 ; -fcheck-bounds causes gcc to generate array bounds checks.
856 ; For C, C++ and ObjC: defaults off.
857 ; For Java: defaults to on.
858 ; For Fortran: defaults to off.
860 Common Report Var(flag_bounds_check)
861 Generate code to check bounds before indexing arrays
864 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
865 Replace add, compare, branch with branch on count register
867 fbranch-probabilities
868 Common Report Var(flag_branch_probabilities) Optimization
869 Use profiling information for branch probabilities
871 fbranch-target-load-optimize
872 Common Report Var(flag_branch_target_load_optimize) Optimization
873 Perform branch target load optimization before prologue / epilogue threading
875 fbranch-target-load-optimize2
876 Common Report Var(flag_branch_target_load_optimize2) Optimization
877 Perform branch target load optimization after prologue / epilogue threading
880 Common Report Var(flag_btr_bb_exclusive) Optimization
881 Restrict target load migration not to re-use registers in any basic block
884 Common Joined RejectNegative Var(common_deferred_options) Defer
885 -fcall-saved-<register> Mark <register> as being preserved across functions
888 Common Joined RejectNegative Var(common_deferred_options) Defer
889 -fcall-used-<register> Mark <register> as being corrupted by function calls
891 ; Nonzero for -fcaller-saves: allocate values in regs that need to
892 ; be saved across function calls, if that produces overall better code.
893 ; Optional now, so people can test it.
895 Common Report Var(flag_caller_saves) Optimization
896 Save registers around function calls
899 Common Report Var(flag_check_data_deps)
900 Compare the results of several data dependence analyzers.
902 fcombine-stack-adjustments
903 Common Report Var(flag_combine_stack_adjustments) Optimization
904 Looks for opportunities to reduce stack adjustments and stack references.
907 Common Report Var(flag_no_common,0) Optimization
908 Do not put uninitialized globals in the common section
912 ; Converted by the driver to -fcompare-debug= options.
915 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
916 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
918 fcompare-debug-second
919 Common Driver RejectNegative Var(flag_compare_debug)
920 Run only the second compilation of -fcompare-debug
923 Common Report Var(flag_compare_elim_after_reload) Optimization
924 Perform comparison elimination after register allocation has finished
927 Common Var(flag_conserve_stack) Optimization
928 Do not perform optimizations increasing noticeably stack usage
931 Common Report Var(flag_cprop_registers) Optimization
932 Perform a register copy-propagation optimization pass
935 Common Report Var(flag_crossjumping) Optimization
936 Perform cross-jumping optimization
939 Common Report Var(flag_cse_follow_jumps) Optimization
940 When running CSE, follow jumps to their targets
944 Does nothing. Preserved for backward compatibility.
947 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
948 Omit range reduction step when performing complex division
951 Common Report Var(flag_cx_fortran_rules) Optimization
952 Complex multiplication and division follow Fortran rules
955 Common Report Var(flag_data_sections) Optimization
956 Place data items into their own section
959 Common Report Var(common_deferred_options) Defer
960 List all available debugging counters with their limits and counts.
963 Common RejectNegative Joined Var(common_deferred_options) Defer
964 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
967 Common Joined RejectNegative Var(common_deferred_options) Defer
968 Map one directory name to another in debug information
971 Common Report Var(flag_debug_types_section) Init(0)
972 Output .debug_types section when using DWARF v4 debuginfo.
974 ; Nonzero for -fdefer-pop: don't pop args after each function call
975 ; instead save them up to pop many calls' args with one insns.
977 Common Report Var(flag_defer_pop) Optimization
978 Defer popping functions args from stack until later
981 Common Report Var(flag_delayed_branch) Optimization
982 Attempt to fill delay slots of branch instructions
984 fdelete-dead-exceptions
985 Common Report Var(flag_delete_dead_exceptions) Init(0)
986 Delete dead instructions that may throw exceptions
988 fdelete-null-pointer-checks
989 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
990 Delete useless null pointer checks
993 Common Report Var(flag_devirtualize) Optimization
994 Try to convert virtual calls to direct ones.
996 fdiagnostics-show-location=
997 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
998 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1000 ; Required for these enum values.
1005 Name(diagnostic_prefixing_rule) Type(int)
1008 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1011 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1013 fdiagnostics-show-caret
1014 Common Var(flag_diagnostics_show_caret) Init(1)
1015 Show the source line with a caret indicating the column
1017 fdiagnostics-show-option
1018 Common Var(flag_diagnostics_show_option) Init(1)
1019 Amend appropriate diagnostic messages with the command line option that controls them
1022 Common Joined RejectNegative Var(common_deferred_options) Defer
1023 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1026 Common Joined RejectNegative Var(common_deferred_options) Defer
1027 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1030 Common Joined RejectNegative Var(common_deferred_options) Defer
1031 -fdump-<type> Dump various compiler internals to a file
1034 Driver RejectNegative
1037 Common RejectNegative Joined Var(flag_dump_final_insns)
1038 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1041 Common RejectNegative Joined Var(flag_dump_go_spec)
1042 -fdump-go-spec=filename Write all declarations to file as Go code
1045 Common Report Var(flag_dump_noaddr)
1046 Suppress output of addresses in debugging dumps
1049 Common Var(flag_dump_passes) Init(0)
1050 Dump optimization passes
1053 Common Report Var(flag_dump_unnumbered)
1054 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1056 fdump-unnumbered-links
1057 Common Report Var(flag_dump_unnumbered_links)
1058 Suppress output of previous and next insn numbers in debugging dumps
1061 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1062 Enable CFI tables via GAS assembler directives.
1065 Common Report Var(flag_early_inlining) Init(1) Optimization
1066 Perform early inlining
1068 feliminate-dwarf2-dups
1069 Common Report Var(flag_eliminate_dwarf2_dups)
1070 Perform DWARF2 duplicate elimination
1073 Common Report Var(flag_ipa_sra) Init(0) Optimization
1074 Perform interprocedural reduction of aggregates
1076 feliminate-unused-debug-symbols
1077 Common Report Var(flag_debug_only_used_symbols)
1078 Perform unused type elimination in debug info
1080 feliminate-unused-debug-types
1081 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1082 Perform unused type elimination in debug info
1084 femit-class-debug-always
1085 Common Report Var(flag_emit_class_debug_always) Init(0)
1086 Do not suppress C++ class debug information.
1089 Common Report Var(flag_exceptions) Optimization
1090 Enable exception handling
1092 fexpensive-optimizations
1093 Common Report Var(flag_expensive_optimizations) Optimization
1094 Perform a number of minor, expensive optimizations
1097 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1098 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1101 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1104 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1107 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1113 Common Var(flag_fat_lto_objects) Init(1)
1114 Output lto objects containing both the intermediate language and binary output.
1117 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1118 Assume no NaNs or infinities are generated
1121 Common Joined RejectNegative Var(common_deferred_options) Defer
1122 -ffixed-<register> Mark <register> as being unavailable to the compiler
1125 Common Report Var(flag_float_store) Optimization
1126 Don't allocate floats and doubles in extended-precision registers
1130 Does nothing. Preserved for backward compatibility.
1133 Common Report Var(flag_forward_propagate) Optimization
1134 Perform a forward propagation pass on RTL
1137 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1138 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1141 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1144 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1146 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1148 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1151 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1153 ; Nonzero means don't put addresses of constant functions in registers.
1154 ; Used for compiling the Unix kernel, where strange substitutions are
1155 ; done on the assembly output.
1157 Common Report Var(flag_no_function_cse,0)
1158 Allow function addresses to be held in registers
1161 Common Report Var(flag_function_sections)
1162 Place each function into its own section
1165 Common Report Var(flag_gcse) Optimization
1166 Perform global common subexpression elimination
1169 Common Report Var(flag_gcse_lm) Init(1) Optimization
1170 Perform enhanced load motion during global common subexpression elimination
1173 Common Report Var(flag_gcse_sm) Init(0) Optimization
1174 Perform store motion after global common subexpression elimination
1177 Common Report Var(flag_gcse_las) Init(0) Optimization
1178 Perform redundant load after store elimination in global common subexpression
1182 Common Report Var(flag_gcse_after_reload) Optimization
1183 Perform global common subexpression elimination after register allocation
1186 ; This option is not documented yet as its semantics will change.
1188 Common Report Var(flag_graphite)
1189 Enable in and out of Graphite representation
1192 Common Report Var(flag_graphite_identity) Optimization
1193 Enable Graphite Identity transformation
1195 fhoist-adjacent-loads
1196 Common Report Var(flag_hoist_adjacent_loads) Optimization
1197 Enable hoisting adjacent loads to encourage generating conditional move
1200 floop-parallelize-all
1201 Common Report Var(flag_loop_parallelize_all) Optimization
1202 Mark all loops as parallel
1205 Common Report Var(flag_loop_strip_mine) Optimization
1206 Enable Loop Strip Mining transformation
1209 Common Report Var(flag_loop_interchange) Optimization
1210 Enable Loop Interchange transformation
1213 Common Report Var(flag_loop_block) Optimization
1214 Enable Loop Blocking transformation
1217 Common Report Var(flag_tm)
1218 Enable support for GNU transactional memory
1222 Does nothing. Preserved for backward compatibility.
1225 Common Report Var(flag_loop_optimize_isl) Optimization
1226 Enable the ISL based loop nest optimizer
1228 fstrict-volatile-bitfields
1229 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1230 Force bitfield accesses to match their type width
1232 fguess-branch-probability
1233 Common Report Var(flag_guess_branch_prob) Optimization
1234 Enable guessing of branch probabilities
1236 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1237 ; Generate position-independent code for executables if possible
1238 ; On SVR4 targets, it also controls whether or not to emit a
1239 ; string identifying the compiler.
1241 Common Report Var(flag_no_ident,0)
1242 Process #ident directives
1245 Common Report Var(flag_if_conversion) Optimization
1246 Perform conversion of conditional jumps to branchless equivalents
1249 Common Report Var(flag_if_conversion2) Optimization
1250 Perform conversion of conditional jumps to conditional execution
1253 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1254 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1257 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1260 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1263 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1266 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1268 ftree-loop-if-convert
1269 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1270 Convert conditional jumps in innermost loops to branchless equivalents
1272 ftree-loop-if-convert-stores
1273 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1274 Also if-convert conditional jumps containing memory writes
1276 ; -finhibit-size-directive inhibits output of .size for ELF.
1277 ; This is used only for compiling crtstuff.c,
1278 ; and it may be extended to other effects
1279 ; needed for crtstuff.c on other systems.
1280 finhibit-size-directive
1281 Common Report Var(flag_inhibit_size_directive)
1282 Do not generate .size directives
1285 Common Report Var(flag_indirect_inlining)
1286 Perform indirect inlining
1288 ; General flag to enable inlining. Specifying -fno-inline will disable
1289 ; all inlining apart from always-inline functions.
1291 Common Report Var(flag_no_inline,0) Init(0) Optimization
1292 Enable inlining of function declared \"inline\", disabling disables all inlining
1294 finline-small-functions
1295 Common Report Var(flag_inline_small_functions) Optimization
1296 Integrate functions into their callers when code size is known not to grow
1299 Common Report Var(flag_inline_functions) Optimization
1300 Integrate functions not declared \"inline\" into their callers when profitable
1302 finline-functions-called-once
1303 Common Report Var(flag_inline_functions_called_once) Optimization
1304 Integrate functions only required by their single caller
1307 Common RejectNegative Joined Alias(finline-limit=)
1310 Common RejectNegative Joined UInteger
1311 -finline-limit=<number> Limit the size of inlined functions to <number>
1314 Common Report Var(flag_inline_atomics) Init(1) Optimization
1315 Inline __atomic operations when a lock free instruction sequence is available.
1317 finstrument-functions
1318 Common Report Var(flag_instrument_function_entry_exit)
1319 Instrument function entry and exit with profiling calls
1321 finstrument-functions-exclude-function-list=
1322 Common RejectNegative Joined
1323 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1325 finstrument-functions-exclude-file-list=
1326 Common RejectNegative Joined
1327 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1330 Common Report Var(flag_ipa_cp) Optimization
1331 Perform Interprocedural constant propagation
1334 Common Report Var(flag_ipa_cp_clone) Optimization
1335 Perform cloning to make Interprocedural constant propagation stronger
1338 Common Report Var(flag_ipa_profile) Init(0) Optimization
1339 Perform interprocedural profile propagation
1342 Common Report Var(flag_ipa_pta) Init(0) Optimization
1343 Perform interprocedural points-to analysis
1346 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1347 Discover pure and const functions
1350 Common Report Var(flag_ipa_reference) Init(0) Optimization
1351 Discover readonly and non addressable static variables
1355 Does nothing. Preserved for backward compatibility.
1359 Does nothing. Preserved for backward compatibility.
1362 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1363 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1366 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1369 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1372 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1375 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1376 -fira-region=[one|all|mixed] Set regions for IRA
1379 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1382 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1385 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1388 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1391 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1392 Use IRA based register pressure calculation
1393 in RTL hoist optimizations.
1396 Common Report Var(flag_ira_loop_pressure)
1397 Use IRA based register pressure calculation
1398 in RTL loop optimizations.
1400 fira-share-save-slots
1401 Common Report Var(flag_ira_share_save_slots) Init(1)
1402 Share slots for saving different hard registers.
1404 fira-share-spill-slots
1405 Common Report Var(flag_ira_share_spill_slots) Init(1)
1406 Share stack slots for spilled pseudo-registers.
1409 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1410 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1413 Common Report Var(flag_ivopts) Init(1) Optimization
1414 Optimize induction variables on trees
1417 Common Var(flag_jump_tables) Init(1) Optimization
1418 Use jump tables for sufficiently large switch statements
1420 fkeep-inline-functions
1421 Common Report Var(flag_keep_inline_functions)
1422 Generate code for functions even if they are fully inlined
1425 Common Report Var(flag_keep_static_consts) Init(1)
1426 Emit static const variables even if they are not used
1429 Common Report Var(flag_leading_underscore) Init(-1)
1430 Give external symbols a leading underscore
1434 Does nothing. Preserved for backward compatibility.
1438 Enable link-time optimization.
1441 Common RejectNegative Joined Var(flag_lto)
1442 Link-time optimization with number of parallel jobs or jobserver.
1445 Common Var(flag_lto_partition_1to1)
1446 Partition symbols and vars at linktime based on object files they originate from
1448 flto-partition=balanced
1449 Common Var(flag_lto_partition_balanced)
1450 Partition functions and vars at linktime into approximately same sized buckets
1453 Common Var(flag_lto_partition_max)
1454 Put every symbol into separate partition
1457 Common Var(flag_lto_partition_none)
1458 Disable partioning and streaming
1460 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1461 flto-compression-level=
1462 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1463 -flto-compression-level=<number> Use zlib compression level <number> for IL
1466 Common Report Var(flag_lto_report) Init(0)
1467 Report various link-time optimization statistics
1470 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1471 Set errno after built-in math functions
1474 Common Joined RejectNegative UInteger Var(flag_max_errors)
1475 -fmax-errors=<number> Maximum number of errors to report
1478 Common Report Var(mem_report)
1479 Report on permanent memory allocation
1482 Common Report Var(mem_report_wpa)
1483 Report on permanent memory allocation in WPA only
1485 ; This will attempt to merge constant section constants, if 1 only
1486 ; string constants and constants from constant pool, if 2 also constant
1488 fmerge-all-constants
1489 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1490 Attempt to merge identical constants and constant variables
1493 Common Report Var(flag_merge_constants,1) Optimization
1494 Attempt to merge identical constants across compilation units
1496 fmerge-debug-strings
1497 Common Report Var(flag_merge_debug_strings) Init(1)
1498 Attempt to merge identical debug strings across compilation units
1501 Common RejectNegative Joined UInteger
1502 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1505 Common Report Var(flag_modulo_sched) Optimization
1506 Perform SMS based modulo scheduling before the first scheduling pass
1508 fmodulo-sched-allow-regmoves
1509 Common Report Var(flag_modulo_sched_allow_regmoves)
1510 Perform SMS based modulo scheduling with register moves allowed
1512 fmove-loop-invariants
1513 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1514 Move loop invariant computations out of loops
1517 Common Var(flag_dce) Init(1) Optimization
1518 Use the RTL dead code elimination pass
1521 Common Var(flag_dse) Init(1) Optimization
1522 Use the RTL dead store elimination pass
1524 freschedule-modulo-scheduled-loops
1525 Common Report Var(flag_resched_modulo_sched) Optimization
1526 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1528 fnon-call-exceptions
1529 Common Report Var(flag_non_call_exceptions) Optimization
1530 Support synchronous non-call exceptions
1533 Common Report Var(flag_omit_frame_pointer) Optimization
1534 When possible do not generate stack frames
1537 Common Report Var(flag_opt_info) Optimization
1538 Enable all optimization info dumps on stderr
1541 Common Joined RejectNegative Var(common_deferred_options) Defer
1542 -fopt-info[-<type>=filename] Dump compiler optimization details
1544 foptimize-register-move
1545 Common Report Var(flag_regmove) Optimization
1546 Do the full register move optimization pass
1548 foptimize-sibling-calls
1549 Common Report Var(flag_optimize_sibling_calls) Optimization
1550 Optimize sibling and tail recursive calls
1553 Common Report Var(flag_partial_inlining)
1554 Perform partial inlining
1557 Common Report Var(pre_ipa_mem_report)
1558 Report on memory allocation before interprocedural optimization
1560 fpost-ipa-mem-report
1561 Common Report Var(post_ipa_mem_report)
1562 Report on memory allocation before interprocedural optimization
1565 Common Report Var(flag_pack_struct) Optimization
1566 Pack structure members together without holes
1569 Common RejectNegative Joined UInteger Optimization
1570 -fpack-struct=<number> Set initial maximum structure member alignment
1573 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1574 Return small aggregates in memory, not registers
1577 Common Report Var(flag_peel_loops) Optimization
1578 Perform loop peeling
1581 Common Report Var(flag_no_peephole,0) Optimization
1582 Enable machine specific peephole optimizations
1585 Common Report Var(flag_peephole2) Optimization
1586 Enable an RTL peephole pass before sched2
1589 Common Report Var(flag_pic,2) Negative(fPIE)
1590 Generate position-independent code if possible (large mode)
1593 Common Report Var(flag_pie,2) Negative(fpic)
1594 Generate position-independent code for executables if possible (large mode)
1597 Common Report Var(flag_pic,1) Negative(fpie)
1598 Generate position-independent code if possible (small mode)
1601 Common Report Var(flag_pie,1) Negative(fPIC)
1602 Generate position-independent code for executables if possible (small mode)
1605 Common Joined RejectNegative Var(common_deferred_options) Defer
1606 Specify a plugin to load
1609 Common Joined RejectNegative Var(common_deferred_options) Defer
1610 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1612 fpredictive-commoning
1613 Common Report Var(flag_predictive_commoning) Optimization
1614 Run predictive commoning optimization.
1616 fprefetch-loop-arrays
1617 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1618 Generate prefetch instructions, if available, for arrays in loops
1621 Common Report Var(profile_flag)
1622 Enable basic program profiling code
1625 Common Report Var(profile_arc_flag)
1626 Insert arc-based program profiling code
1629 Common Joined RejectNegative Var(profile_data_prefix)
1630 Set the top-level directory for storing the profile data.
1631 The default is 'pwd'.
1634 Common Report Var(flag_profile_correction)
1635 Enable correction of flow inconsistent profile data input
1639 Enable common options for generating profile info for profile feedback directed optimizations
1642 Common Joined RejectNegative
1643 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1646 Common Var(flag_profile_use)
1647 Enable common options for performing profile feedback directed optimizations
1650 Common Joined RejectNegative
1651 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1654 Common Report Var(flag_profile_values)
1655 Insert code to profile values of expressions
1658 Common Report Var(profile_report)
1659 Report on consistency of profile
1662 Common Var(common_deferred_options) Defer
1665 Common Joined RejectNegative Var(common_deferred_options) Defer
1666 -frandom-seed=<string> Make compile reproducible using <string>
1668 ; This switch causes the command line that was used to create an
1669 ; object file to be recorded into the object file. The exact format
1670 ; of this recording is target and binary file format dependent.
1671 ; It is related to the -fverbose-asm switch, but that switch only
1672 ; records information in the assembler output file as comments, so
1673 ; they never reach the object file.
1674 frecord-gcc-switches
1675 Common Report Var(flag_record_gcc_switches)
1676 Record gcc command line switches in the object file.
1679 Common Report Var(flag_pcc_struct_return,0) Optimization
1680 Return small aggregates in registers
1683 Common Report Var(flag_regmove) Optimization
1684 Enables a register move optimization
1687 Common Report Var(flag_rename_registers) Init(2) Optimization
1688 Perform a register renaming optimization pass
1691 Common Report Var(flag_reorder_blocks) Optimization
1692 Reorder basic blocks to improve code placement
1694 freorder-blocks-and-partition
1695 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1696 Reorder basic blocks and partition into hot and cold sections
1699 Common Report Var(flag_reorder_functions) Optimization
1700 Reorder functions to improve code placement
1702 frerun-cse-after-loop
1703 Common Report Var(flag_rerun_cse_after_loop) Optimization
1704 Add a common subexpression elimination pass after loop optimizations
1708 Does nothing. Preserved for backward compatibility.
1711 Common Report Var(flag_rounding_math) Optimization SetByCombined
1712 Disable optimizations that assume default FP rounding behavior
1715 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1716 Enable scheduling across basic blocks
1719 Common Report Var(flag_sched_pressure) Init(0) Optimization
1720 Enable register pressure sensitive insn scheduling
1723 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1724 Allow speculative motion of non-loads
1727 Common Report Var(flag_schedule_speculative_load) Optimization
1728 Allow speculative motion of some loads
1730 fsched-spec-load-dangerous
1731 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1732 Allow speculative motion of more loads
1735 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1736 -fsched-verbose=<number> Set the verbosity level of the scheduler
1738 fsched2-use-superblocks
1739 Common Report Var(flag_sched2_use_superblocks) Optimization
1740 If scheduling post reload, do superblock scheduling
1744 Does nothing. Preserved for backward compatibility.
1747 Common Report Var(flag_schedule_insns) Optimization
1748 Reschedule instructions before register allocation
1751 Common Report Var(flag_schedule_insns_after_reload) Optimization
1752 Reschedule instructions after register allocation
1754 ; This flag should be on when a target implements non-trivial
1755 ; scheduling hooks, maybe saving some information for its own sake.
1756 ; On IA64, for example, this is used for correct bundling.
1757 fselective-scheduling
1758 Common Report Var(flag_selective_scheduling) Optimization
1759 Schedule instructions using selective scheduling algorithm
1761 fselective-scheduling2
1762 Common Report Var(flag_selective_scheduling2) Optimization
1763 Run selective scheduling after reload
1765 fsel-sched-pipelining
1766 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1767 Perform software pipelining of inner loops during selective scheduling
1769 fsel-sched-pipelining-outer-loops
1770 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1771 Perform software pipelining of outer loops during selective scheduling
1773 fsel-sched-reschedule-pipelined
1774 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1775 Reschedule pipelined regions without pipelining
1777 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1778 ; of stalled insns into the ready list.
1779 fsched-stalled-insns
1780 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1781 Allow premature scheduling of queued insns
1783 fsched-stalled-insns=
1784 Common RejectNegative Joined UInteger
1785 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1787 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1788 ; be examined for a dependency on a stalled insn that is candidate for
1789 ; premature removal from the queue of stalled insns into the ready list (has
1790 ; an effect only if the flag 'sched_stalled_insns' is set).
1791 fsched-stalled-insns-dep
1792 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1793 Set dependence distance checking in premature scheduling of queued insns
1795 fsched-stalled-insns-dep=
1796 Common RejectNegative Joined UInteger
1797 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1799 fsched-group-heuristic
1800 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1801 Enable the group heuristic in the scheduler
1803 fsched-critical-path-heuristic
1804 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1805 Enable the critical path heuristic in the scheduler
1807 fsched-spec-insn-heuristic
1808 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1809 Enable the speculative instruction heuristic in the scheduler
1811 fsched-rank-heuristic
1812 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1813 Enable the rank heuristic in the scheduler
1815 fsched-last-insn-heuristic
1816 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1817 Enable the last instruction heuristic in the scheduler
1819 fsched-dep-count-heuristic
1820 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1821 Enable the dependent count heuristic in the scheduler
1824 Common Report Var(flag_section_anchors) Optimization
1825 Access data in the same section from shared anchor points
1829 Does nothing. Preserved for backward compatibility.
1833 Does nothing. Preserved for backward compatibility.
1836 Common Report Var(flag_ree) Init(0)
1837 Turn on Redundant Extensions Elimination pass.
1840 Common Report Var(flag_show_column) Init(1)
1841 Show column numbers in diagnostics, when available. Default on
1844 Common Report Var(flag_shrink_wrap) Optimization
1845 Emit function prologues only before parts of the function that need it,
1846 rather than at the top of the function.
1849 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1850 Disable optimizations observable by IEEE signaling NaNs
1853 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1854 Disable floating point optimizations that ignore the IEEE signedness of zero
1856 fsingle-precision-constant
1857 Common Report Var(flag_single_precision_constant) Optimization
1858 Convert floating point constants to single precision constants
1860 fsplit-ivs-in-unroller
1861 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1862 Split lifetimes of induction variables when loops are unrolled
1865 Common Report Var(flag_split_stack) Init(-1)
1866 Generate discontiguous stack frames
1869 Common Report Var(flag_split_wide_types) Optimization
1870 Split wide types into independent registers
1872 fvariable-expansion-in-unroller
1873 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1874 Apply variable expansion when loops are unrolled
1877 Common Report RejectNegative Joined
1878 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1881 Common Alias(fstack-check=, specific, no)
1882 Insert stack checking code into the program. Same as -fstack-check=specific
1885 Common Var(common_deferred_options) Defer
1887 fstack-limit-register=
1888 Common RejectNegative Joined Var(common_deferred_options) Defer
1889 -fstack-limit-register=<register> Trap if the stack goes past <register>
1891 fstack-limit-symbol=
1892 Common RejectNegative Joined Var(common_deferred_options) Defer
1893 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1896 Common Report Var(flag_stack_protect, 1)
1897 Use propolice as a stack protection method
1899 fstack-protector-all
1900 Common Report RejectNegative Var(flag_stack_protect, 2)
1901 Use a stack protection method for every function
1904 Common RejectNegative Var(flag_stack_usage)
1905 Output stack usage information on a per-function basis
1909 Does nothing. Preserved for backward compatibility.
1911 ; Nonzero if we should do (language-dependent) alias analysis.
1912 ; Typically, this analysis will assume that expressions of certain
1913 ; types do not alias expressions of certain other types. Only used
1914 ; if alias analysis (in general) is enabled.
1916 Common Report Var(flag_strict_aliasing) Optimization
1917 Assume strict aliasing rules apply
1920 Common Report Var(flag_strict_overflow)
1921 Treat signed overflow as undefined
1924 Common Report Var(flag_sync_libcalls) Init(1)
1925 Implement __atomic operations via libcalls to legacy __sync functions
1928 Common Report Var(flag_syntax_only)
1929 Check for syntax errors, then stop
1932 Common Report Var(flag_test_coverage)
1933 Create data files needed by \"gcov\"
1936 Common Report Var(flag_thread_jumps) Optimization
1937 Perform jump threading optimizations
1940 Common Report Var(time_report)
1941 Report the time taken by each compiler pass
1944 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1945 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1948 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1951 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1954 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1957 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1960 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1963 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1964 Reorder top level functions, variables, and asms
1967 Common Report Var(flag_tracer)
1968 Perform superblock formation via tail duplication
1970 ; Zero means that floating-point math operations cannot generate a
1971 ; (user-visible) trap. This is the case, for example, in nonstop
1972 ; IEEE 754 arithmetic.
1974 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1975 Assume floating-point operations can trap
1978 Common Report Var(flag_trapv) Optimization
1979 Trap for signed overflow in addition, subtraction and multiplication
1982 Common Report Var(flag_tree_ccp) Optimization
1983 Enable SSA-CCP optimization on trees
1986 Common Report Var(flag_tree_bit_ccp) Optimization
1987 Enable SSA-BIT-CCP optimization on trees
1991 Does nothing. Preserved for backward compatibility.
1994 Common Report Var(flag_tree_ch) Optimization
1995 Enable loop header copying on trees
1997 ftree-coalesce-inlined-vars
1998 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
1999 Enable coalescing of copy-related user variables that are inlined
2002 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2003 Enable coalescing of all copy-related user variables
2006 Common Report Var(flag_tree_copyrename) Optimization
2007 Replace SSA temporaries with better names in copies
2010 Common Report Var(flag_tree_copy_prop) Optimization
2011 Enable copy propagation on trees
2013 ftree-store-copy-prop
2015 Does nothing. Preserved for backward compatibility.
2018 Common Report Var(flag_tree_cselim) Init(2) Optimization
2019 Transform condition stores into unconditional ones
2021 ftree-switch-conversion
2022 Common Report Var(flag_tree_switch_conversion) Optimization
2023 Perform conversions of switch initializations.
2026 Common Report Var(flag_tree_dce) Optimization
2027 Enable SSA dead code elimination optimization on trees
2029 ftree-dominator-opts
2030 Common Report Var(flag_tree_dom) Optimization
2031 Enable dominator optimizations
2034 Common Report Var(flag_tree_tail_merge) Optimization
2035 Enable tail merging on trees
2038 Common Report Var(flag_tree_dse) Optimization
2039 Enable dead store elimination
2042 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2043 Enable forward propagation on trees
2046 Common Report Var(flag_tree_fre) Optimization
2047 Enable Full Redundancy Elimination (FRE) on trees
2050 Common Report Var(flag_optimize_strlen) Optimization
2051 Enable string length optimizations on trees
2053 ftree-loop-distribution
2054 Common Report Var(flag_tree_loop_distribution) Optimization
2055 Enable loop distribution on trees
2057 ftree-loop-distribute-patterns
2058 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2059 Enable loop distribution for patterns transformed into a library call
2062 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2063 Enable loop invariant motion on trees
2066 Common Alias(floop-interchange)
2067 Enable loop interchange transforms. Same as -floop-interchange
2070 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2071 Create canonical induction variables in loops
2074 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2075 Enable loop optimizations on tree level
2077 ftree-parallelize-loops=
2078 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2079 Enable automatic parallelization of loops
2082 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2083 Enable hoisting loads from conditional pointers.
2086 Common Report Var(flag_tree_pre) Optimization
2087 Enable SSA-PRE optimization on trees
2090 Common Report Var(flag_tree_partial_pre) Optimization
2091 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2094 Common Report Var(flag_tree_pta) Init(1) Optimization
2095 Perform function-local points-to analysis on trees.
2098 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2099 Enable reassociation on tree level
2103 Does nothing. Preserved for backward compatibility.
2106 Common Report Var(flag_tree_sink) Optimization
2107 Enable SSA code sinking on trees
2110 Common Report Var(flag_tree_slsr) Optimization
2111 Perform straight-line strength reduction
2114 Common Report Var(flag_tree_sra) Optimization
2115 Perform scalar replacement of aggregates
2118 Common Report Var(flag_tree_ter) Optimization
2119 Replace temporary expressions in the SSA->normal pass
2122 Common Report Var(flag_tree_live_range_split) Optimization
2123 Perform live range splitting during the SSA->normal pass
2126 Common Report Var(flag_tree_vrp) Init(0) Optimization
2127 Perform Value Range Propagation on trees
2130 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2131 Compile whole compilation unit at a time
2134 Common Report Var(flag_unroll_loops) Optimization
2135 Perform loop unrolling when iteration count is known
2138 Common Report Var(flag_unroll_all_loops) Optimization
2139 Perform loop unrolling for all loops
2141 ; Nonzero means that loop optimizer may assume that the induction variables
2142 ; that control loops do not overflow and that the loops with nontrivial
2143 ; exit condition are not infinite
2144 funsafe-loop-optimizations
2145 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2146 Allow loop optimizations to assume that the loops behave in normal way
2149 Common Report Var(flag_associative_math) SetByCombined
2150 Allow optimization for floating-point arithmetic which may change the
2151 result of the operation due to rounding.
2154 Common Report Var(flag_reciprocal_math) SetByCombined
2155 Same as -fassociative-math for expressions which include division.
2157 ; Nonzero means that unsafe floating-point math optimizations are allowed
2158 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2159 ; are allowed to assume that their arguments and results are "normal"
2160 ; (e.g., nonnegative for SQRT).
2161 funsafe-math-optimizations
2162 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2163 Allow math optimizations that may violate IEEE or ISO standards
2166 Common Report Var(flag_unswitch_loops) Optimization
2167 Perform loop unswitching
2170 Common Report Var(flag_unwind_tables) Optimization
2171 Just generate unwind tables for exception handling
2176 ; Positive if we should track variables, negative if we should run
2177 ; the var-tracking pass only to discard debug annotations, zero if
2178 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2179 ; will be set according to optimize, debug_info_level and debug_hooks
2180 ; in process_options ().
2182 Common Report Var(flag_var_tracking) Init(2) Optimization
2183 Perform variable tracking
2185 ; Positive if we should track variables at assignments, negative if
2186 ; we should run the var-tracking pass only to discard debug
2187 ; annotations. When flag_var_tracking_assignments ==
2188 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2189 fvar-tracking-assignments
2190 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2191 Perform variable tracking by annotating assignments
2193 ; Nonzero if we should toggle flag_var_tracking_assignments after
2194 ; processing options and computing its default. */
2195 fvar-tracking-assignments-toggle
2196 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2197 Toggle -fvar-tracking-assignments
2199 ; Positive if we should track uninitialized variables, negative if
2200 ; we should run the var-tracking pass only to discard debug
2201 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2202 ; will be set according to flag_var_tracking.
2203 fvar-tracking-uninit
2204 Common Report Var(flag_var_tracking_uninit) Optimization
2205 Perform variable tracking and also tag variables that are uninitialized
2208 Common Report Var(flag_tree_vectorize) Optimization
2209 Enable loop vectorization on trees
2211 ftree-vectorizer-verbose=
2212 Common RejectNegative Joined UInteger Var(common_deferred_options) Defer
2213 -ftree-vectorizer-verbose=<number> This switch is deprecated. Use -fopt-info instead.
2216 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2217 Enable basic block vectorization (SLP) on trees
2220 Common Report Var(flag_vect_cost_model) Optimization
2221 Enable use of cost model in vectorization
2223 ftree-vect-loop-version
2224 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2225 Enable loop versioning when doing loop vectorization on trees
2228 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2229 Enable copy propagation of scalar-evolution information.
2231 ; -fverbose-asm causes extra commentary information to be produced in
2232 ; the generated assembly code (to make it more readable). This option
2233 ; is generally only of use to those who actually need to read the
2234 ; generated assembly code (perhaps while debugging the compiler itself).
2235 ; -fno-verbose-asm, the default, causes the extra information
2236 ; to not be added and is useful when comparing two assembler files.
2238 Common Report Var(flag_verbose_asm)
2239 Add extra commentary to assembler output
2242 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2243 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2246 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2249 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2252 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2255 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2258 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2261 Common Report Var(flag_value_profile_transformations) Optimization
2262 Use expression value profiles in optimizations
2265 Common Report Var(flag_web) Init(2) Optimization
2266 Construct webs and split unrelated uses of single variable
2268 ftree-builtin-call-dce
2269 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2270 Enable conditional dead code elimination for builtin calls
2273 Common Report Var(flag_whole_program) Init(0) Optimization
2274 Perform whole program optimizations
2277 Common Report Var(flag_wrapv) Optimization
2278 Assume signed arithmetic overflow wraps around
2280 fzero-initialized-in-bss
2281 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2282 Put zero initialized data in the bss section
2285 Common JoinedOrMissing
2286 Generate debug information in default format
2289 Common JoinedOrMissing Negative(gdwarf-)
2290 Generate debug information in COFF format
2293 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2294 Generate debug information in DWARF v2 (or later) format
2297 Common JoinedOrMissing
2298 Generate debug information in default extended format
2301 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2302 Don't generate DWARF pubnames and pubtypes sections.
2305 Common RejectNegative Var(debug_generate_pub_sections, 1)
2306 Generate DWARF pubnames and pubtypes sections.
2308 gno-record-gcc-switches
2309 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2310 Don't record gcc command line switches in DWARF DW_AT_producer.
2312 grecord-gcc-switches
2313 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2314 Record gcc command line switches in DWARF DW_AT_producer.
2317 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2318 Don't generate debug information in separate .dwo files
2321 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2322 Generate debug information in separate .dwo files
2325 Common JoinedOrMissing Negative(gstabs+)
2326 Generate debug information in STABS format
2329 Common JoinedOrMissing Negative(gvms)
2330 Generate debug information in extended STABS format
2333 Common RejectNegative Var(dwarf_strict,0) Init(0)
2334 Emit DWARF additions beyond selected version
2337 Common Report RejectNegative Var(dwarf_strict,1)
2338 Don't emit DWARF additions beyond selected version
2341 Common Report Var(flag_gtoggle)
2342 Toggle debug information generation
2345 Common JoinedOrMissing Negative(gxcoff)
2346 Generate debug information in VMS format
2349 Common JoinedOrMissing Negative(gxcoff+)
2350 Generate debug information in XCOFF format
2353 Common JoinedOrMissing Negative(gcoff)
2354 Generate debug information in extended XCOFF format
2357 Driver Joined Separate
2360 Common Joined Var(plugindir_string) Init(0)
2361 -iplugindir=<dir> Set <dir> to be the default plugin directory
2364 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2365 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2368 Driver Joined Separate
2373 no-canonical-prefixes
2386 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2387 -o <file> Place output into <file>
2390 Common Var(profile_flag)
2391 Enable function profiling
2394 Driver Var(pass_exit_codes)
2397 Common Alias(Wpedantic)
2400 Common Var(flag_pedantic_errors)
2401 Like -pedantic but issue them as errors
2407 Driver Var(use_pipes)
2410 Driver JoinedOrMissing Var(print_file_name)
2412 print-libgcc-file-name
2415 print-multi-directory
2416 Driver Var(print_multi_directory)
2419 Driver Var(print_multi_lib)
2421 print-multi-os-directory
2422 Driver Var(print_multi_os_directory)
2425 Driver Var(print_multiarch)
2428 Driver JoinedOrMissing Var(print_prog_name)
2431 Driver Var(print_search_dirs)
2434 Driver Var(print_sysroot)
2436 print-sysroot-headers-suffix
2437 Driver Var(print_sysroot_headers_suffix)
2440 Common Var(quiet_flag) RejectDriver
2441 Do not display functions compiled or elapsed time
2459 Driver Var(report_times)
2462 Driver JoinedOrMissing
2465 Driver Joined Separate
2469 ; C option, but driver must not handle as "-u ndef".
2472 Common Driver Var(verbose_flag)
2473 Enable verbose output
2476 Common Var(version_flag) RejectDriver
2477 Display the compiler's version
2480 Common Var(inhibit_warnings)
2484 Driver Separate Var(wrapper_string)
2487 Driver Joined Separate
2490 Driver RejectNegative Negative(pie)
2491 Create a shared library
2497 Driver Separate Alias(specs=)
2510 ; Documented for Fortran, but always accepted by driver.
2517 ; Documented for Go, but always accepted by driver.
2526 Driver RejectNegative Negative(shared)
2527 Create a position independent executable
2530 Driver Joined Separate
2532 ; This comment is to ensure we retain the blank line above.