1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2013 Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
49 ; 0 means straightforward implementation of complex divide acceptable.
50 ; 1 means wide ranges of inputs must work for complex divide.
51 ; 2 means C99-like requirements for complex multiply and divide.
53 int flag_complex_method = 1
55 ; Nonzero if subexpressions must be evaluated from left-to-right.
57 int flag_evaluation_order = 0
59 ; Language specific warning pass for unused results.
61 bool flag_warn_unused_result = false
66 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
70 ; True to warn about any objects definitions whose size is larger
71 ; than N bytes. Also want about function definitions whose returned
72 ; values are larger than N bytes, where N is 'larger_than_size'.
77 HOST_WIDE_INT larger_than_size
79 ; True to warn about any function whose frame size is larger
82 bool warn_frame_larger_than
85 HOST_WIDE_INT frame_larger_than_size
87 ; Nonzero means we should be saving declaration info into a .X file.
89 int flag_gen_aux_info = 0
91 ; Nonzero if we are compiling code for a shared library, zero for
96 ; These two are really VEC(char_p,heap) *.
99 void *flag_instrument_functions_exclude_functions
102 void *flag_instrument_functions_exclude_files
104 ; Generic structs (e.g. templates not explicitly specialized)
105 ; may not have a compilation unit associated with them, and so
106 ; may need to be treated differently from ordinary structs.
108 ; Structs only handled by reference (indirectly), will also usually
109 ; not need as much debugging information.
112 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
117 ; True if we should exit after parsing options.
119 bool exit_after_options
121 ; Type(s) of debugging information we are producing (if any). See
122 ; flag-types.h for the definitions of the different possible types of
123 ; debugging information.
125 enum debug_info_type write_symbols = NO_DEBUG
127 ; Level of debugging information we are producing. See flag-types.h
128 ; for the definitions of the different possible levels.
130 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
132 ; Nonzero means use GNU-only extensions in the generated symbolic
133 ; debugging information. Currently, this only has an effect when
134 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
136 bool use_gnu_debug_info_extensions
138 ; Original value of maximum field alignment in bytes, specified via
139 ; -fpack-struct=<value>.
141 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
143 ; Type of stack check.
145 enum stack_check_type flag_stack_check = NO_STACK_CHECK
147 ; True if stack usage information needs to be computed.
149 bool flag_stack_usage_info = false
151 ; -dA causes debug commentary information to be produced in
152 ; the generated assembly code (to make it more readable). This option
153 ; is generally only of use to those who actually need to read the
154 ; generated assembly code (perhaps while debugging the compiler itself).
155 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
156 ; to be a catchall for printing debug information in the assembler file.
160 ; -dP causes the rtl to be emitted as a comment in assembly.
162 int flag_dump_rtl_in_asm
164 ; Whether -da was passed (used only in handle_common_deferred_options).
166 bool flag_dump_all_passed
168 ; Other flags saying which kinds of debugging dump have been requested.
171 int rtl_dump_and_exit
174 int flag_print_asm_name
176 ; Name of top-level original source file (what was input to cpp).
177 ; This comes from the #-command at the beginning of the actual input.
178 ; If there isn't any there, then this is the cc1 input file name.
180 const char *main_input_filename
182 ; Pointer to base name in main_input_filename, with directories and a
183 ; single final extension removed, and the length of this base
187 const char *main_input_basename
190 int main_input_baselength
192 ; Which options have been printed by --help.
196 ; Which enums have been printed by --help. 0 = not printed, no
197 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
200 char *help_enum_printed
202 ; The number of columns for --help output.
204 unsigned int help_columns
206 ; Whether this options structure has been through finish_options
208 bool flag_opts_finished
220 Driver Alias(coverage)
226 Common Separate Alias(d)
229 Common Joined Alias(d)
232 Common Separate Alias(dumpbase)
235 Common Separate Alias(dumpdir)
238 Driver Separate Alias(e)
241 Driver Joined Alias(e)
244 Common Warning Alias(Wextra)
247 Driver Separate Alias(Xassembler)
250 Driver JoinedOrMissing Alias(Xassembler)
253 Driver Separate Alias(Xlinker)
256 Driver JoinedOrMissing Alias(Xlinker)
259 Driver Separate Alias(u)
262 Driver Joined Alias(u)
265 Common Driver Var(help_flag)
266 Display this information
269 Common Driver Report Joined
270 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
273 Driver Separate Alias(x)
276 Driver Joined Alias(x)
279 Driver Separate Alias(L)
282 Driver Joined Alias(L)
284 -no-canonical-prefixes
285 Driver Alias(no-canonical-prefixes)
287 -no-standard-libraries
288 Driver Alias(nostdlib)
291 Driver Var(no_sysroot_suffix)
300 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
303 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
306 Driver Alias(pass-exit-codes)
309 Common Alias(Wpedantic)
312 Common Alias(pedantic-errors)
321 Driver Separate Alias(B)
324 Driver JoinedOrMissing Alias(B)
330 Driver Separate Alias(print-file-name=)
333 Driver JoinedOrMissing Alias(print-file-name=)
335 -print-libgcc-file-name
336 Driver Alias(print-libgcc-file-name)
338 -print-multi-directory
339 Driver Alias(print-multi-directory)
342 Driver Alias(print-multi-lib)
344 -print-multi-os-directory
345 Driver Alias(print-multi-os-directory)
348 Driver Alias(print-multiarch)
351 Driver Separate Alias(print-prog-name=)
354 Driver JoinedOrMissing Alias(print-prog-name=)
357 Driver Alias(print-search-dirs)
360 Driver Alias(print-sysroot)
362 -print-sysroot-headers-suffix
363 Driver Alias(print-sysroot-headers-suffix)
369 Driver Alias(save-temps)
375 Driver Separate Alias(specs=)
378 Driver Joined Alias(specs=)
384 Driver Alias(symbolic)
388 Alias for --help=target
396 ;; The driver used to convert options such as --help into forms such
397 ;; as -fhelp; the following four entries are for compatibility with
398 ;; any direct uses of those (undocumented) -f forms
400 Common Driver Alias(-help)
403 Common Driver Joined Alias(-help=)
406 Common Driver Alias(-target-help)
409 Common Driver Alias(-version)
413 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
416 Common Joined Alias(-param)
419 Driver Separate Alias(-sysroot=)
422 Driver JoinedOrMissing
428 Driver Joined Separate
434 Driver Joined Separate
440 Common JoinedOrMissing Optimization
441 -O<number> Set optimization level to <number>
445 Optimize for space rather than speed
449 Optimize for speed disregarding exact standards compliance
453 Optimize for debugging experience rather than speed or size
465 Driver Joined Separate
471 Driver Joined Separate
492 Common RejectNegative Warning Alias(Wextra)
493 This switch is deprecated; use -Wextra instead
496 Driver JoinedOrMissing
499 Driver JoinedOrMissing
502 Driver JoinedOrMissing
505 Common Var(warn_aggregate_return) Warning
506 Warn about returning structures, unions or arrays
508 Waggressive-loop-optimizations
509 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
510 Warn if a loop with constant number of iterations triggers undefined behavior
513 Common Var(warn_array_bounds) Warning
514 Warn if an array is accessed out of bounds
517 Common Var(warn_attributes) Init(1) Warning
518 Warn about inappropriate attribute usage
521 Common Var(warn_cast_align) Warning
522 Warn about pointer casts which increase alignment
525 Common Var(warn_cpp) Init(1) Warning
526 Warn when a #warning directive is encountered
528 Wdeprecated-declarations
529 Common Var(warn_deprecated_decl) Init(1) Warning
530 Warn about uses of __attribute__((deprecated)) declarations
532 Wdisabled-optimization
533 Common Var(warn_disabled_optimization) Warning
534 Warn when an optimization pass is disabled
537 Common Var(warnings_are_errors)
538 Treat all warnings as errors
542 Treat specified warning as error
545 Common Var(extra_warnings) Warning
546 Print extra (possibly unwanted) warnings
549 Common Var(flag_fatal_errors)
550 Exit on the first error occurred
553 Common RejectNegative Joined UInteger
554 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
557 Common Var(warn_free_nonheap_object) Init(1) Warning
558 Warn when attempting to free a non-heap object
561 Common Var(warn_inline) Warning
562 Warn when an inlined function cannot be inlined
564 Winvalid-memory-model
565 Common Var(warn_invalid_memory_model) Init(1) Warning
566 Warn when an atomic memory model parameter is known to be outside the valid range.
569 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
572 Common RejectNegative Joined UInteger Warning
573 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
575 Wunsafe-loop-optimizations
576 Common Var(warn_unsafe_loop_optimizations) Warning
577 Warn if the loop cannot be optimized due to nontrivial assumptions.
580 Common Alias(Wsuggest-attribute=noreturn)
583 Common Var(warn_overflow) Init(1) Warning
584 Warn about overflow in arithmetic expressions
587 Common Var(warn_packed) Warning
588 Warn when the packed attribute has no effect on struct layout
591 Common Var(warn_padded) Warning
592 Warn when padding is required to align structure members
595 Common Var(pedantic) Warning
596 Issue warnings needed for strict compliance to the standard
599 Common Var(warn_shadow) Warning
600 Warn when one local variable shadows another
603 Common Var(warn_stack_protect) Warning
604 Warn when not issuing stack smashing protection for some reason
607 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
608 Warn if stack usage might be larger than specified amount
612 Warn about code which might break strict aliasing rules
615 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
616 Warn about code which might break strict aliasing rules
620 Warn about optimizations that assume that signed overflow is undefined
623 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
624 Warn about optimizations that assume that signed overflow is undefined
626 Wsuggest-attribute=const
627 Common Var(warn_suggest_attribute_const) Warning
628 Warn about functions which might be candidates for __attribute__((const))
630 Wsuggest-attribute=pure
631 Common Var(warn_suggest_attribute_pure) Warning
632 Warn about functions which might be candidates for __attribute__((pure))
634 Wsuggest-attribute=noreturn
635 Common Var(warn_suggest_attribute_noreturn) Warning
636 Warn about functions which might be candidates for __attribute__((noreturn))
639 Common Var(warn_system_headers) Warning
640 Do not suppress warnings from system headers
643 Common Var(warn_trampolines) Warning
644 Warn whenever a trampoline is generated
647 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
648 Warn if a comparison is always true or always false due to the limited range of the data type
651 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
652 Warn about uninitialized automatic variables
655 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
656 Warn about maybe uninitialized automatic variables
660 Does nothing. Preserved for backward compatibility.
663 Common Var(warn_unused) Init(0) Warning
664 Enable all -Wunused- warnings
666 Wunused-but-set-parameter
667 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
668 Warn when a function parameter is only set, otherwise unused
670 Wunused-but-set-variable
671 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
672 Warn when a variable is only set, otherwise unused
675 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
676 Warn when a function is unused
679 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
680 Warn when a label is unused
683 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
684 Warn when a function parameter is unused
687 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
688 Warn when an expression value is unused
691 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
692 Warn when a variable is unused
695 Common Var(warn_coverage_mismatch) Init(1) Warning
696 Warn in case profiles in -fprofile-use do not match
698 Wvector-operation-performance
699 Common Var(warn_vector_operation_performance) Warning
700 Warn when a vector operation is compiled outside the SIMD
715 Common Separate Var(aux_info_file_name)
716 -aux-info <file> Emit declaration information into <file>
719 Common Joined Alias(aux-info)
722 Common Separate RejectDriver Var(aux_base_name)
725 Common Separate RejectDriver
735 -d<letters> Enable dumps from specific passes of the compiler
738 Common Separate Var(dump_base_name)
739 -dumpbase <file> Set the file basename to be used for dumps
742 Common Separate Var(dump_dir_name)
743 -dumpdir <dir> Set the directory name to be used for dumps
755 Driver Joined Separate
757 ; This option has historically been passed down to the linker by an
758 ; accident of a %{e*} spec, so ensure it continues to be passed down
759 ; as a single option. The supported option for this purpose is
760 ; -rdynamic. See PR 47390.
764 ; The version of the C++ ABI in use. The following values are allowed:
766 ; 0: The version of the ABI believed most conformant with the C++ ABI
767 ; specification. This ABI may change as bugs are discovered and fixed.
768 ; Therefore, 0 will not necessarily indicate the same ABI in different
771 ; 1: The version of the ABI first used in G++ 3.2.
773 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
775 ; 3: The version of the ABI that fixes the missing underscore
776 ; in template non-type arguments of pointer type.
778 ; 4: The version of the ABI that introduces unambiguous mangling of
779 ; vector types. First selectable in G++ 4.5.
781 ; 5: The version of the ABI that ignores attribute const/noreturn
782 ; in function pointer mangling, and corrects mangling of decltype and
783 ; function parameters used in other parameters and the return type.
784 ; First selectable in G++ 4.6.
786 ; 6: The version of the ABI that doesn't promote scoped enums to int and
787 ; changes the mangling of template argument packs, const/static_cast,
788 ; prefix ++ and --, and a class scope function used as a template
790 ; First selectable in G++ 4.7.
792 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
793 ; corrects the mangling of lambdas in default argument scope.
794 ; First selectable in G++ 4.8.
796 ; 8: The version of the ABI that corrects the substitution behavior of
797 ; function types with function-cv-qualifiers.
798 ; First selectable in G++ 4.9.
800 ; Additional positive integers will be assigned as new versions of
801 ; the ABI become the default version of the ABI.
803 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
805 faggressive-loop-optimizations
806 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
807 Aggressively optimize loops using language constraints
810 Common Report Var(align_functions,0) Optimization UInteger
811 Align the start of functions
814 Common RejectNegative Joined UInteger Var(align_functions)
817 Common Report Var(align_jumps,0) Optimization UInteger
818 Align labels which are only reached by jumping
821 Common RejectNegative Joined UInteger Var(align_jumps)
824 Common Report Var(align_labels,0) Optimization UInteger
828 Common RejectNegative Joined UInteger Var(align_labels)
831 Common Report Var(align_loops,0) Optimization UInteger
832 Align the start of loops
835 Common RejectNegative Joined UInteger Var(align_loops)
839 Does nothing. Preserved for backward compatibility.
843 Does nothing. Preserved for backward compatibility.
845 fargument-noalias-global
847 Does nothing. Preserved for backward compatibility.
849 fargument-noalias-anything
851 Does nothing. Preserved for backward compatibility.
854 Common Report Var(flag_asan)
855 Enable AddressSanitizer, a memory error detector
858 Common Report Var(flag_tsan)
859 Enable ThreadSanitizer, a data race detector
861 fasynchronous-unwind-tables
862 Common Report Var(flag_asynchronous_unwind_tables) Optimization
863 Generate unwind tables that are exact at each instruction boundary
866 Common Report Var(flag_auto_inc_dec) Init(1)
867 Generate auto-inc/dec instructions
869 ; -fcheck-bounds causes gcc to generate array bounds checks.
870 ; For C, C++ and ObjC: defaults off.
871 ; For Java: defaults to on.
872 ; For Fortran: defaults to off.
874 Common Report Var(flag_bounds_check)
875 Generate code to check bounds before indexing arrays
878 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
879 Replace add, compare, branch with branch on count register
881 fbranch-probabilities
882 Common Report Var(flag_branch_probabilities) Optimization
883 Use profiling information for branch probabilities
885 fbranch-target-load-optimize
886 Common Report Var(flag_branch_target_load_optimize) Optimization
887 Perform branch target load optimization before prologue / epilogue threading
889 fbranch-target-load-optimize2
890 Common Report Var(flag_branch_target_load_optimize2) Optimization
891 Perform branch target load optimization after prologue / epilogue threading
894 Common Report Var(flag_btr_bb_exclusive) Optimization
895 Restrict target load migration not to re-use registers in any basic block
898 Common Joined RejectNegative Var(common_deferred_options) Defer
899 -fcall-saved-<register> Mark <register> as being preserved across functions
902 Common Joined RejectNegative Var(common_deferred_options) Defer
903 -fcall-used-<register> Mark <register> as being corrupted by function calls
905 ; Nonzero for -fcaller-saves: allocate values in regs that need to
906 ; be saved across function calls, if that produces overall better code.
907 ; Optional now, so people can test it.
909 Common Report Var(flag_caller_saves) Optimization
910 Save registers around function calls
913 Common Report Var(flag_check_data_deps)
914 Compare the results of several data dependence analyzers.
916 fcombine-stack-adjustments
917 Common Report Var(flag_combine_stack_adjustments) Optimization
918 Looks for opportunities to reduce stack adjustments and stack references.
921 Common Report Var(flag_no_common,0) Optimization
922 Do not put uninitialized globals in the common section
926 ; Converted by the driver to -fcompare-debug= options.
929 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
930 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
932 fcompare-debug-second
933 Common Driver RejectNegative Var(flag_compare_debug)
934 Run only the second compilation of -fcompare-debug
937 Common Report Var(flag_compare_elim_after_reload) Optimization
938 Perform comparison elimination after register allocation has finished
941 Common Var(flag_conserve_stack) Optimization
942 Do not perform optimizations increasing noticeably stack usage
945 Common Report Var(flag_cprop_registers) Optimization
946 Perform a register copy-propagation optimization pass
949 Common Report Var(flag_crossjumping) Optimization
950 Perform cross-jumping optimization
953 Common Report Var(flag_cse_follow_jumps) Optimization
954 When running CSE, follow jumps to their targets
958 Does nothing. Preserved for backward compatibility.
961 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
962 Omit range reduction step when performing complex division
965 Common Report Var(flag_cx_fortran_rules) Optimization
966 Complex multiplication and division follow Fortran rules
969 Common Report Var(flag_data_sections) Optimization
970 Place data items into their own section
973 Common Report Var(common_deferred_options) Defer
974 List all available debugging counters with their limits and counts.
977 Common RejectNegative Joined Var(common_deferred_options) Defer
978 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
981 Common Joined RejectNegative Var(common_deferred_options) Defer
982 Map one directory name to another in debug information
985 Common Report Var(flag_debug_types_section) Init(0)
986 Output .debug_types section when using DWARF v4 debuginfo.
988 ; Nonzero for -fdefer-pop: don't pop args after each function call
989 ; instead save them up to pop many calls' args with one insns.
991 Common Report Var(flag_defer_pop) Optimization
992 Defer popping functions args from stack until later
995 Common Report Var(flag_delayed_branch) Optimization
996 Attempt to fill delay slots of branch instructions
998 fdelete-dead-exceptions
999 Common Report Var(flag_delete_dead_exceptions) Init(0)
1000 Delete dead instructions that may throw exceptions
1002 fdelete-null-pointer-checks
1003 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
1004 Delete useless null pointer checks
1007 Common Report Var(flag_devirtualize) Optimization
1008 Try to convert virtual calls to direct ones.
1010 fdiagnostics-show-location=
1011 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1012 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1014 ; Required for these enum values.
1019 Name(diagnostic_prefixing_rule) Type(int)
1022 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1025 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1027 fdiagnostics-show-caret
1028 Common Var(flag_diagnostics_show_caret) Init(1)
1029 Show the source line with a caret indicating the column
1031 fdiagnostics-show-option
1032 Common Var(flag_diagnostics_show_option) Init(1)
1033 Amend appropriate diagnostic messages with the command line option that controls them
1036 Common Joined RejectNegative Var(common_deferred_options) Defer
1037 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1040 Common Joined RejectNegative Var(common_deferred_options) Defer
1041 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1044 Common Joined RejectNegative Var(common_deferred_options) Defer
1045 -fdump-<type> Dump various compiler internals to a file
1048 Driver RejectNegative
1051 Common RejectNegative Joined Var(flag_dump_final_insns)
1052 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1055 Common RejectNegative Joined Var(flag_dump_go_spec)
1056 -fdump-go-spec=filename Write all declarations to file as Go code
1059 Common Report Var(flag_dump_noaddr)
1060 Suppress output of addresses in debugging dumps
1063 Common Var(flag_dump_passes) Init(0)
1064 Dump optimization passes
1067 Common Report Var(flag_dump_unnumbered)
1068 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1070 fdump-unnumbered-links
1071 Common Report Var(flag_dump_unnumbered_links)
1072 Suppress output of previous and next insn numbers in debugging dumps
1075 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1076 Enable CFI tables via GAS assembler directives.
1079 Common Report Var(flag_early_inlining) Init(1) Optimization
1080 Perform early inlining
1082 feliminate-dwarf2-dups
1083 Common Report Var(flag_eliminate_dwarf2_dups)
1084 Perform DWARF2 duplicate elimination
1087 Common Report Var(flag_ipa_sra) Init(0) Optimization
1088 Perform interprocedural reduction of aggregates
1090 feliminate-unused-debug-symbols
1091 Common Report Var(flag_debug_only_used_symbols)
1092 Perform unused type elimination in debug info
1094 feliminate-unused-debug-types
1095 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1096 Perform unused type elimination in debug info
1098 femit-class-debug-always
1099 Common Report Var(flag_emit_class_debug_always) Init(0)
1100 Do not suppress C++ class debug information.
1103 Common Report Var(flag_exceptions) Optimization
1104 Enable exception handling
1106 fexpensive-optimizations
1107 Common Report Var(flag_expensive_optimizations) Optimization
1108 Perform a number of minor, expensive optimizations
1111 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1112 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1115 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1118 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1121 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1127 Common Var(flag_fat_lto_objects) Init(1)
1128 Output lto objects containing both the intermediate language and binary output.
1131 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1132 Assume no NaNs or infinities are generated
1135 Common Joined RejectNegative Var(common_deferred_options) Defer
1136 -ffixed-<register> Mark <register> as being unavailable to the compiler
1139 Common Report Var(flag_float_store) Optimization
1140 Don't allocate floats and doubles in extended-precision registers
1144 Does nothing. Preserved for backward compatibility.
1147 Common Report Var(flag_forward_propagate) Optimization
1148 Perform a forward propagation pass on RTL
1151 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1152 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1155 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1158 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1160 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1162 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1165 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1167 ; Nonzero means don't put addresses of constant functions in registers.
1168 ; Used for compiling the Unix kernel, where strange substitutions are
1169 ; done on the assembly output.
1171 Common Report Var(flag_no_function_cse,0)
1172 Allow function addresses to be held in registers
1175 Common Report Var(flag_function_sections)
1176 Place each function into its own section
1179 Common Report Var(flag_gcse) Optimization
1180 Perform global common subexpression elimination
1183 Common Report Var(flag_gcse_lm) Init(1) Optimization
1184 Perform enhanced load motion during global common subexpression elimination
1187 Common Report Var(flag_gcse_sm) Init(0) Optimization
1188 Perform store motion after global common subexpression elimination
1191 Common Report Var(flag_gcse_las) Init(0) Optimization
1192 Perform redundant load after store elimination in global common subexpression
1196 Common Report Var(flag_gcse_after_reload) Optimization
1197 Perform global common subexpression elimination after register allocation
1200 ; This option is not documented yet as its semantics will change.
1202 Common Report Var(flag_graphite)
1203 Enable in and out of Graphite representation
1206 Common Report Var(flag_graphite_identity) Optimization
1207 Enable Graphite Identity transformation
1209 fhoist-adjacent-loads
1210 Common Report Var(flag_hoist_adjacent_loads) Optimization
1211 Enable hoisting adjacent loads to encourage generating conditional move
1214 floop-parallelize-all
1215 Common Report Var(flag_loop_parallelize_all) Optimization
1216 Mark all loops as parallel
1219 Common Report Var(flag_loop_strip_mine) Optimization
1220 Enable Loop Strip Mining transformation
1223 Common Report Var(flag_loop_interchange) Optimization
1224 Enable Loop Interchange transformation
1227 Common Report Var(flag_loop_block) Optimization
1228 Enable Loop Blocking transformation
1231 Common Report Var(flag_tm)
1232 Enable support for GNU transactional memory
1236 Does nothing. Preserved for backward compatibility.
1239 Common Report Var(flag_loop_optimize_isl) Optimization
1240 Enable the ISL based loop nest optimizer
1242 fstrict-volatile-bitfields
1243 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1244 Force bitfield accesses to match their type width
1246 fguess-branch-probability
1247 Common Report Var(flag_guess_branch_prob) Optimization
1248 Enable guessing of branch probabilities
1250 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1251 ; Generate position-independent code for executables if possible
1252 ; On SVR4 targets, it also controls whether or not to emit a
1253 ; string identifying the compiler.
1255 Common Report Var(flag_no_ident,0)
1256 Process #ident directives
1259 Common Report Var(flag_if_conversion) Optimization
1260 Perform conversion of conditional jumps to branchless equivalents
1263 Common Report Var(flag_if_conversion2) Optimization
1264 Perform conversion of conditional jumps to conditional execution
1267 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1268 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1271 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1274 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1277 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1280 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1282 ftree-loop-if-convert
1283 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1284 Convert conditional jumps in innermost loops to branchless equivalents
1286 ftree-loop-if-convert-stores
1287 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1288 Also if-convert conditional jumps containing memory writes
1290 ; -finhibit-size-directive inhibits output of .size for ELF.
1291 ; This is used only for compiling crtstuff.c,
1292 ; and it may be extended to other effects
1293 ; needed for crtstuff.c on other systems.
1294 finhibit-size-directive
1295 Common Report Var(flag_inhibit_size_directive)
1296 Do not generate .size directives
1299 Common Report Var(flag_indirect_inlining)
1300 Perform indirect inlining
1302 ; General flag to enable inlining. Specifying -fno-inline will disable
1303 ; all inlining apart from always-inline functions.
1305 Common Report Var(flag_no_inline,0) Init(0) Optimization
1306 Enable inlining of function declared \"inline\", disabling disables all inlining
1308 finline-small-functions
1309 Common Report Var(flag_inline_small_functions) Optimization
1310 Integrate functions into their callers when code size is known not to grow
1313 Common Report Var(flag_inline_functions) Optimization
1314 Integrate functions not declared \"inline\" into their callers when profitable
1316 finline-functions-called-once
1317 Common Report Var(flag_inline_functions_called_once) Optimization
1318 Integrate functions only required by their single caller
1321 Common RejectNegative Joined Alias(finline-limit=)
1324 Common RejectNegative Joined UInteger
1325 -finline-limit=<number> Limit the size of inlined functions to <number>
1328 Common Report Var(flag_inline_atomics) Init(1) Optimization
1329 Inline __atomic operations when a lock free instruction sequence is available.
1331 finstrument-functions
1332 Common Report Var(flag_instrument_function_entry_exit)
1333 Instrument function entry and exit with profiling calls
1335 finstrument-functions-exclude-function-list=
1336 Common RejectNegative Joined
1337 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1339 finstrument-functions-exclude-file-list=
1340 Common RejectNegative Joined
1341 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1344 Common Report Var(flag_ipa_cp) Optimization
1345 Perform Interprocedural constant propagation
1348 Common Report Var(flag_ipa_cp_clone) Optimization
1349 Perform cloning to make Interprocedural constant propagation stronger
1352 Common Report Var(flag_ipa_profile) Init(0) Optimization
1353 Perform interprocedural profile propagation
1356 Common Report Var(flag_ipa_pta) Init(0) Optimization
1357 Perform interprocedural points-to analysis
1360 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1361 Discover pure and const functions
1364 Common Report Var(flag_ipa_reference) Init(0) Optimization
1365 Discover readonly and non addressable static variables
1369 Does nothing. Preserved for backward compatibility.
1373 Does nothing. Preserved for backward compatibility.
1376 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1377 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1380 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1383 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1386 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1389 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1390 -fira-region=[one|all|mixed] Set regions for IRA
1393 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1396 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1399 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1402 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1405 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1406 Use IRA based register pressure calculation
1407 in RTL hoist optimizations.
1410 Common Report Var(flag_ira_loop_pressure)
1411 Use IRA based register pressure calculation
1412 in RTL loop optimizations.
1414 fira-share-save-slots
1415 Common Report Var(flag_ira_share_save_slots) Init(1)
1416 Share slots for saving different hard registers.
1418 fira-share-spill-slots
1419 Common Report Var(flag_ira_share_spill_slots) Init(1)
1420 Share stack slots for spilled pseudo-registers.
1423 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1424 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1427 Common Report Var(flag_ivopts) Init(1) Optimization
1428 Optimize induction variables on trees
1431 Common Var(flag_jump_tables) Init(1) Optimization
1432 Use jump tables for sufficiently large switch statements
1434 fkeep-inline-functions
1435 Common Report Var(flag_keep_inline_functions)
1436 Generate code for functions even if they are fully inlined
1439 Common Report Var(flag_keep_static_consts) Init(1)
1440 Emit static const variables even if they are not used
1443 Common Report Var(flag_leading_underscore) Init(-1)
1444 Give external symbols a leading underscore
1448 Does nothing. Preserved for backward compatibility.
1452 Enable link-time optimization.
1455 Common RejectNegative Joined Var(flag_lto)
1456 Link-time optimization with number of parallel jobs or jobserver.
1459 Common Var(flag_lto_partition_1to1)
1460 Partition symbols and vars at linktime based on object files they originate from
1462 flto-partition=balanced
1463 Common Var(flag_lto_partition_balanced)
1464 Partition functions and vars at linktime into approximately same sized buckets
1467 Common Var(flag_lto_partition_max)
1468 Put every symbol into separate partition
1471 Common Var(flag_lto_partition_none)
1472 Disable partioning and streaming
1474 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1475 flto-compression-level=
1476 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1477 -flto-compression-level=<number> Use zlib compression level <number> for IL
1480 Common Report Var(flag_lto_report) Init(0)
1481 Report various link-time optimization statistics
1484 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1485 Set errno after built-in math functions
1488 Common Joined RejectNegative UInteger Var(flag_max_errors)
1489 -fmax-errors=<number> Maximum number of errors to report
1492 Common Report Var(mem_report)
1493 Report on permanent memory allocation
1496 Common Report Var(mem_report_wpa)
1497 Report on permanent memory allocation in WPA only
1499 ; This will attempt to merge constant section constants, if 1 only
1500 ; string constants and constants from constant pool, if 2 also constant
1502 fmerge-all-constants
1503 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1504 Attempt to merge identical constants and constant variables
1507 Common Report Var(flag_merge_constants,1) Optimization
1508 Attempt to merge identical constants across compilation units
1510 fmerge-debug-strings
1511 Common Report Var(flag_merge_debug_strings) Init(1)
1512 Attempt to merge identical debug strings across compilation units
1515 Common RejectNegative Joined UInteger
1516 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1519 Common Report Var(flag_modulo_sched) Optimization
1520 Perform SMS based modulo scheduling before the first scheduling pass
1522 fmodulo-sched-allow-regmoves
1523 Common Report Var(flag_modulo_sched_allow_regmoves)
1524 Perform SMS based modulo scheduling with register moves allowed
1526 fmove-loop-invariants
1527 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1528 Move loop invariant computations out of loops
1531 Common Var(flag_dce) Init(1) Optimization
1532 Use the RTL dead code elimination pass
1535 Common Var(flag_dse) Init(1) Optimization
1536 Use the RTL dead store elimination pass
1538 freschedule-modulo-scheduled-loops
1539 Common Report Var(flag_resched_modulo_sched) Optimization
1540 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1542 fnon-call-exceptions
1543 Common Report Var(flag_non_call_exceptions) Optimization
1544 Support synchronous non-call exceptions
1547 Common Report Var(flag_omit_frame_pointer) Optimization
1548 When possible do not generate stack frames
1551 Common Report Var(flag_opt_info) Optimization
1552 Enable all optimization info dumps on stderr
1555 Common Joined RejectNegative Var(common_deferred_options) Defer
1556 -fopt-info[-<type>=filename] Dump compiler optimization details
1558 foptimize-register-move
1559 Common Report Var(flag_regmove) Optimization
1560 Do the full register move optimization pass
1562 foptimize-sibling-calls
1563 Common Report Var(flag_optimize_sibling_calls) Optimization
1564 Optimize sibling and tail recursive calls
1567 Common Report Var(flag_partial_inlining)
1568 Perform partial inlining
1571 Common Report Var(pre_ipa_mem_report)
1572 Report on memory allocation before interprocedural optimization
1574 fpost-ipa-mem-report
1575 Common Report Var(post_ipa_mem_report)
1576 Report on memory allocation before interprocedural optimization
1579 Common Report Var(flag_pack_struct) Optimization
1580 Pack structure members together without holes
1583 Common RejectNegative Joined UInteger Optimization
1584 -fpack-struct=<number> Set initial maximum structure member alignment
1587 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1588 Return small aggregates in memory, not registers
1591 Common Report Var(flag_peel_loops) Optimization
1592 Perform loop peeling
1595 Common Report Var(flag_no_peephole,0) Optimization
1596 Enable machine specific peephole optimizations
1599 Common Report Var(flag_peephole2) Optimization
1600 Enable an RTL peephole pass before sched2
1603 Common Report Var(flag_pic,2) Negative(fPIE)
1604 Generate position-independent code if possible (large mode)
1607 Common Report Var(flag_pie,2) Negative(fpic)
1608 Generate position-independent code for executables if possible (large mode)
1611 Common Report Var(flag_pic,1) Negative(fpie)
1612 Generate position-independent code if possible (small mode)
1615 Common Report Var(flag_pie,1) Negative(fPIC)
1616 Generate position-independent code for executables if possible (small mode)
1619 Common Joined RejectNegative Var(common_deferred_options) Defer
1620 Specify a plugin to load
1623 Common Joined RejectNegative Var(common_deferred_options) Defer
1624 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1626 fpredictive-commoning
1627 Common Report Var(flag_predictive_commoning) Optimization
1628 Run predictive commoning optimization.
1630 fprefetch-loop-arrays
1631 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1632 Generate prefetch instructions, if available, for arrays in loops
1635 Common Report Var(profile_flag)
1636 Enable basic program profiling code
1639 Common Report Var(profile_arc_flag)
1640 Insert arc-based program profiling code
1643 Common Joined RejectNegative Var(profile_data_prefix)
1644 Set the top-level directory for storing the profile data.
1645 The default is 'pwd'.
1648 Common Report Var(flag_profile_correction)
1649 Enable correction of flow inconsistent profile data input
1653 Enable common options for generating profile info for profile feedback directed optimizations
1656 Common Joined RejectNegative
1657 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1660 Common Var(flag_profile_use)
1661 Enable common options for performing profile feedback directed optimizations
1664 Common Joined RejectNegative
1665 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1668 Common Report Var(flag_profile_values)
1669 Insert code to profile values of expressions
1672 Common Report Var(profile_report)
1673 Report on consistency of profile
1676 Common Var(common_deferred_options) Defer
1679 Common Joined RejectNegative Var(common_deferred_options) Defer
1680 -frandom-seed=<string> Make compile reproducible using <string>
1682 ; This switch causes the command line that was used to create an
1683 ; object file to be recorded into the object file. The exact format
1684 ; of this recording is target and binary file format dependent.
1685 ; It is related to the -fverbose-asm switch, but that switch only
1686 ; records information in the assembler output file as comments, so
1687 ; they never reach the object file.
1688 frecord-gcc-switches
1689 Common Report Var(flag_record_gcc_switches)
1690 Record gcc command line switches in the object file.
1693 Common Report Var(flag_pcc_struct_return,0) Optimization
1694 Return small aggregates in registers
1697 Common Report Var(flag_regmove) Optimization
1698 Enables a register move optimization
1701 Common Report Var(flag_rename_registers) Init(2) Optimization
1702 Perform a register renaming optimization pass
1705 Common Report Var(flag_reorder_blocks) Optimization
1706 Reorder basic blocks to improve code placement
1708 freorder-blocks-and-partition
1709 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1710 Reorder basic blocks and partition into hot and cold sections
1713 Common Report Var(flag_reorder_functions) Optimization
1714 Reorder functions to improve code placement
1716 frerun-cse-after-loop
1717 Common Report Var(flag_rerun_cse_after_loop) Optimization
1718 Add a common subexpression elimination pass after loop optimizations
1722 Does nothing. Preserved for backward compatibility.
1725 Common Report Var(flag_rounding_math) Optimization SetByCombined
1726 Disable optimizations that assume default FP rounding behavior
1729 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1730 Enable scheduling across basic blocks
1733 Common Report Var(flag_sched_pressure) Init(0) Optimization
1734 Enable register pressure sensitive insn scheduling
1737 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1738 Allow speculative motion of non-loads
1741 Common Report Var(flag_schedule_speculative_load) Optimization
1742 Allow speculative motion of some loads
1744 fsched-spec-load-dangerous
1745 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1746 Allow speculative motion of more loads
1749 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1750 -fsched-verbose=<number> Set the verbosity level of the scheduler
1752 fsched2-use-superblocks
1753 Common Report Var(flag_sched2_use_superblocks) Optimization
1754 If scheduling post reload, do superblock scheduling
1758 Does nothing. Preserved for backward compatibility.
1761 Common Report Var(flag_schedule_insns) Optimization
1762 Reschedule instructions before register allocation
1765 Common Report Var(flag_schedule_insns_after_reload) Optimization
1766 Reschedule instructions after register allocation
1768 ; This flag should be on when a target implements non-trivial
1769 ; scheduling hooks, maybe saving some information for its own sake.
1770 ; On IA64, for example, this is used for correct bundling.
1771 fselective-scheduling
1772 Common Report Var(flag_selective_scheduling) Optimization
1773 Schedule instructions using selective scheduling algorithm
1775 fselective-scheduling2
1776 Common Report Var(flag_selective_scheduling2) Optimization
1777 Run selective scheduling after reload
1779 fsel-sched-pipelining
1780 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1781 Perform software pipelining of inner loops during selective scheduling
1783 fsel-sched-pipelining-outer-loops
1784 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1785 Perform software pipelining of outer loops during selective scheduling
1787 fsel-sched-reschedule-pipelined
1788 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1789 Reschedule pipelined regions without pipelining
1791 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1792 ; of stalled insns into the ready list.
1793 fsched-stalled-insns
1794 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1795 Allow premature scheduling of queued insns
1797 fsched-stalled-insns=
1798 Common RejectNegative Joined UInteger
1799 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1801 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1802 ; be examined for a dependency on a stalled insn that is candidate for
1803 ; premature removal from the queue of stalled insns into the ready list (has
1804 ; an effect only if the flag 'sched_stalled_insns' is set).
1805 fsched-stalled-insns-dep
1806 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1807 Set dependence distance checking in premature scheduling of queued insns
1809 fsched-stalled-insns-dep=
1810 Common RejectNegative Joined UInteger
1811 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1813 fsched-group-heuristic
1814 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1815 Enable the group heuristic in the scheduler
1817 fsched-critical-path-heuristic
1818 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1819 Enable the critical path heuristic in the scheduler
1821 fsched-spec-insn-heuristic
1822 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1823 Enable the speculative instruction heuristic in the scheduler
1825 fsched-rank-heuristic
1826 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1827 Enable the rank heuristic in the scheduler
1829 fsched-last-insn-heuristic
1830 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1831 Enable the last instruction heuristic in the scheduler
1833 fsched-dep-count-heuristic
1834 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1835 Enable the dependent count heuristic in the scheduler
1838 Common Report Var(flag_section_anchors) Optimization
1839 Access data in the same section from shared anchor points
1843 Does nothing. Preserved for backward compatibility.
1847 Does nothing. Preserved for backward compatibility.
1850 Common Report Var(flag_ree) Init(0)
1851 Turn on Redundant Extensions Elimination pass.
1854 Common Report Var(flag_show_column) Init(1)
1855 Show column numbers in diagnostics, when available. Default on
1858 Common Report Var(flag_shrink_wrap) Optimization
1859 Emit function prologues only before parts of the function that need it,
1860 rather than at the top of the function.
1863 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1864 Disable optimizations observable by IEEE signaling NaNs
1867 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1868 Disable floating point optimizations that ignore the IEEE signedness of zero
1870 fsingle-precision-constant
1871 Common Report Var(flag_single_precision_constant) Optimization
1872 Convert floating point constants to single precision constants
1874 fsplit-ivs-in-unroller
1875 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1876 Split lifetimes of induction variables when loops are unrolled
1879 Common Report Var(flag_split_stack) Init(-1)
1880 Generate discontiguous stack frames
1883 Common Report Var(flag_split_wide_types) Optimization
1884 Split wide types into independent registers
1886 fvariable-expansion-in-unroller
1887 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1888 Apply variable expansion when loops are unrolled
1891 Common Report RejectNegative Joined
1892 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1895 Common Alias(fstack-check=, specific, no)
1896 Insert stack checking code into the program. Same as -fstack-check=specific
1899 Common Var(common_deferred_options) Defer
1901 fstack-limit-register=
1902 Common RejectNegative Joined Var(common_deferred_options) Defer
1903 -fstack-limit-register=<register> Trap if the stack goes past <register>
1905 fstack-limit-symbol=
1906 Common RejectNegative Joined Var(common_deferred_options) Defer
1907 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1910 Common Report Var(flag_stack_protect, 1)
1911 Use propolice as a stack protection method
1913 fstack-protector-all
1914 Common Report RejectNegative Var(flag_stack_protect, 2)
1915 Use a stack protection method for every function
1918 Common RejectNegative Var(flag_stack_usage)
1919 Output stack usage information on a per-function basis
1923 Does nothing. Preserved for backward compatibility.
1925 ; Nonzero if we should do (language-dependent) alias analysis.
1926 ; Typically, this analysis will assume that expressions of certain
1927 ; types do not alias expressions of certain other types. Only used
1928 ; if alias analysis (in general) is enabled.
1930 Common Report Var(flag_strict_aliasing) Optimization
1931 Assume strict aliasing rules apply
1934 Common Report Var(flag_strict_overflow)
1935 Treat signed overflow as undefined
1938 Common Report Var(flag_sync_libcalls) Init(1)
1939 Implement __atomic operations via libcalls to legacy __sync functions
1942 Common Report Var(flag_syntax_only)
1943 Check for syntax errors, then stop
1946 Common Report Var(flag_test_coverage)
1947 Create data files needed by \"gcov\"
1950 Common Report Var(flag_thread_jumps) Optimization
1951 Perform jump threading optimizations
1954 Common Report Var(time_report)
1955 Report the time taken by each compiler pass
1958 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1959 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1962 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1965 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1968 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1971 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1974 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1977 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1978 Reorder top level functions, variables, and asms
1981 Common Report Var(flag_tracer)
1982 Perform superblock formation via tail duplication
1984 ; Zero means that floating-point math operations cannot generate a
1985 ; (user-visible) trap. This is the case, for example, in nonstop
1986 ; IEEE 754 arithmetic.
1988 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1989 Assume floating-point operations can trap
1992 Common Report Var(flag_trapv) Optimization
1993 Trap for signed overflow in addition, subtraction and multiplication
1996 Common Report Var(flag_tree_ccp) Optimization
1997 Enable SSA-CCP optimization on trees
2000 Common Report Var(flag_tree_bit_ccp) Optimization
2001 Enable SSA-BIT-CCP optimization on trees
2005 Does nothing. Preserved for backward compatibility.
2008 Common Report Var(flag_tree_ch) Optimization
2009 Enable loop header copying on trees
2011 ftree-coalesce-inlined-vars
2012 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2013 Enable coalescing of copy-related user variables that are inlined
2016 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2017 Enable coalescing of all copy-related user variables
2020 Common Report Var(flag_tree_copyrename) Optimization
2021 Replace SSA temporaries with better names in copies
2024 Common Report Var(flag_tree_copy_prop) Optimization
2025 Enable copy propagation on trees
2027 ftree-store-copy-prop
2029 Does nothing. Preserved for backward compatibility.
2032 Common Report Var(flag_tree_cselim) Init(2) Optimization
2033 Transform condition stores into unconditional ones
2035 ftree-switch-conversion
2036 Common Report Var(flag_tree_switch_conversion) Optimization
2037 Perform conversions of switch initializations.
2040 Common Report Var(flag_tree_dce) Optimization
2041 Enable SSA dead code elimination optimization on trees
2043 ftree-dominator-opts
2044 Common Report Var(flag_tree_dom) Optimization
2045 Enable dominator optimizations
2048 Common Report Var(flag_tree_tail_merge) Optimization
2049 Enable tail merging on trees
2052 Common Report Var(flag_tree_dse) Optimization
2053 Enable dead store elimination
2056 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2057 Enable forward propagation on trees
2060 Common Report Var(flag_tree_fre) Optimization
2061 Enable Full Redundancy Elimination (FRE) on trees
2064 Common Report Var(flag_optimize_strlen) Optimization
2065 Enable string length optimizations on trees
2067 ftree-loop-distribution
2068 Common Report Var(flag_tree_loop_distribution) Optimization
2069 Enable loop distribution on trees
2071 ftree-loop-distribute-patterns
2072 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2073 Enable loop distribution for patterns transformed into a library call
2076 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2077 Enable loop invariant motion on trees
2080 Common Alias(floop-interchange)
2081 Enable loop interchange transforms. Same as -floop-interchange
2084 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2085 Create canonical induction variables in loops
2088 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2089 Enable loop optimizations on tree level
2091 ftree-parallelize-loops=
2092 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2093 Enable automatic parallelization of loops
2096 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2097 Enable hoisting loads from conditional pointers.
2100 Common Report Var(flag_tree_pre) Optimization
2101 Enable SSA-PRE optimization on trees
2104 Common Report Var(flag_tree_partial_pre) Optimization
2105 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2108 Common Report Var(flag_tree_pta) Init(1) Optimization
2109 Perform function-local points-to analysis on trees.
2112 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2113 Enable reassociation on tree level
2117 Does nothing. Preserved for backward compatibility.
2120 Common Report Var(flag_tree_sink) Optimization
2121 Enable SSA code sinking on trees
2124 Common Report Var(flag_tree_slsr) Optimization
2125 Perform straight-line strength reduction
2128 Common Report Var(flag_tree_sra) Optimization
2129 Perform scalar replacement of aggregates
2132 Common Report Var(flag_tree_ter) Optimization
2133 Replace temporary expressions in the SSA->normal pass
2136 Common Report Var(flag_tree_live_range_split) Optimization
2137 Perform live range splitting during the SSA->normal pass
2140 Common Report Var(flag_tree_vrp) Init(0) Optimization
2141 Perform Value Range Propagation on trees
2144 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2145 Compile whole compilation unit at a time
2148 Common Report Var(flag_unroll_loops) Optimization
2149 Perform loop unrolling when iteration count is known
2152 Common Report Var(flag_unroll_all_loops) Optimization
2153 Perform loop unrolling for all loops
2155 ; Nonzero means that loop optimizer may assume that the induction variables
2156 ; that control loops do not overflow and that the loops with nontrivial
2157 ; exit condition are not infinite
2158 funsafe-loop-optimizations
2159 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2160 Allow loop optimizations to assume that the loops behave in normal way
2163 Common Report Var(flag_associative_math) SetByCombined
2164 Allow optimization for floating-point arithmetic which may change the
2165 result of the operation due to rounding.
2168 Common Report Var(flag_reciprocal_math) SetByCombined
2169 Same as -fassociative-math for expressions which include division.
2171 ; Nonzero means that unsafe floating-point math optimizations are allowed
2172 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2173 ; are allowed to assume that their arguments and results are "normal"
2174 ; (e.g., nonnegative for SQRT).
2175 funsafe-math-optimizations
2176 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2177 Allow math optimizations that may violate IEEE or ISO standards
2180 Common Report Var(flag_unswitch_loops) Optimization
2181 Perform loop unswitching
2184 Common Report Var(flag_unwind_tables) Optimization
2185 Just generate unwind tables for exception handling
2188 Common Negative(fuse-ld=gold)
2189 Use the bfd linker instead of the default linker
2192 Common Negative(fuse-ld=bfd)
2193 Use the gold linker instead of the default linker
2198 ; Positive if we should track variables, negative if we should run
2199 ; the var-tracking pass only to discard debug annotations, zero if
2200 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2201 ; will be set according to optimize, debug_info_level and debug_hooks
2202 ; in process_options ().
2204 Common Report Var(flag_var_tracking) Init(2) Optimization
2205 Perform variable tracking
2207 ; Positive if we should track variables at assignments, negative if
2208 ; we should run the var-tracking pass only to discard debug
2209 ; annotations. When flag_var_tracking_assignments ==
2210 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2211 fvar-tracking-assignments
2212 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2213 Perform variable tracking by annotating assignments
2215 ; Nonzero if we should toggle flag_var_tracking_assignments after
2216 ; processing options and computing its default. */
2217 fvar-tracking-assignments-toggle
2218 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2219 Toggle -fvar-tracking-assignments
2221 ; Positive if we should track uninitialized variables, negative if
2222 ; we should run the var-tracking pass only to discard debug
2223 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2224 ; will be set according to flag_var_tracking.
2225 fvar-tracking-uninit
2226 Common Report Var(flag_var_tracking_uninit) Optimization
2227 Perform variable tracking and also tag variables that are uninitialized
2230 Common Report Var(flag_tree_vectorize) Optimization
2231 Enable loop vectorization on trees
2233 ftree-vectorizer-verbose=
2234 Common RejectNegative Joined UInteger Var(common_deferred_options) Defer
2235 -ftree-vectorizer-verbose=<number> This switch is deprecated. Use -fopt-info instead.
2238 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2239 Enable basic block vectorization (SLP) on trees
2242 Common Report Var(flag_vect_cost_model) Optimization
2243 Enable use of cost model in vectorization
2245 ftree-vect-loop-version
2246 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2247 Enable loop versioning when doing loop vectorization on trees
2250 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2251 Enable copy propagation of scalar-evolution information.
2253 ; -fverbose-asm causes extra commentary information to be produced in
2254 ; the generated assembly code (to make it more readable). This option
2255 ; is generally only of use to those who actually need to read the
2256 ; generated assembly code (perhaps while debugging the compiler itself).
2257 ; -fno-verbose-asm, the default, causes the extra information
2258 ; to not be added and is useful when comparing two assembler files.
2260 Common Report Var(flag_verbose_asm)
2261 Add extra commentary to assembler output
2264 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2265 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2268 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2271 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2274 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2277 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2280 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2283 Common Report Var(flag_value_profile_transformations) Optimization
2284 Use expression value profiles in optimizations
2287 Common Report Var(flag_web) Init(2) Optimization
2288 Construct webs and split unrelated uses of single variable
2290 ftree-builtin-call-dce
2291 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2292 Enable conditional dead code elimination for builtin calls
2295 Common Report Var(flag_whole_program) Init(0) Optimization
2296 Perform whole program optimizations
2299 Common Report Var(flag_wrapv) Optimization
2300 Assume signed arithmetic overflow wraps around
2302 fzero-initialized-in-bss
2303 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2304 Put zero initialized data in the bss section
2307 Common JoinedOrMissing
2308 Generate debug information in default format
2311 Common JoinedOrMissing Negative(gdwarf)
2312 Generate debug information in COFF format
2315 Common JoinedOrMissing Negative(gdwarf-)
2316 Generate debug information in default version of DWARF format
2319 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2320 Generate debug information in DWARF v2 (or later) format
2323 Common JoinedOrMissing
2324 Generate debug information in default extended format
2327 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2328 Don't generate DWARF pubnames and pubtypes sections.
2331 Common RejectNegative Var(debug_generate_pub_sections, 1)
2332 Generate DWARF pubnames and pubtypes sections.
2334 gno-record-gcc-switches
2335 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2336 Don't record gcc command line switches in DWARF DW_AT_producer.
2338 grecord-gcc-switches
2339 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2340 Record gcc command line switches in DWARF DW_AT_producer.
2343 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2344 Don't generate debug information in separate .dwo files
2347 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2348 Generate debug information in separate .dwo files
2351 Common JoinedOrMissing Negative(gstabs+)
2352 Generate debug information in STABS format
2355 Common JoinedOrMissing Negative(gvms)
2356 Generate debug information in extended STABS format
2359 Common RejectNegative Var(dwarf_strict,0) Init(0)
2360 Emit DWARF additions beyond selected version
2363 Common Report RejectNegative Var(dwarf_strict,1)
2364 Don't emit DWARF additions beyond selected version
2367 Common Report Var(flag_gtoggle)
2368 Toggle debug information generation
2371 Common JoinedOrMissing Negative(gxcoff)
2372 Generate debug information in VMS format
2375 Common JoinedOrMissing Negative(gxcoff+)
2376 Generate debug information in XCOFF format
2379 Common JoinedOrMissing Negative(gcoff)
2380 Generate debug information in extended XCOFF format
2383 Driver Joined Separate
2386 Common Joined Var(plugindir_string) Init(0)
2387 -iplugindir=<dir> Set <dir> to be the default plugin directory
2390 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2391 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2394 Driver Joined Separate
2399 no-canonical-prefixes
2412 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2413 -o <file> Place output into <file>
2416 Common Var(profile_flag)
2417 Enable function profiling
2420 Driver Var(pass_exit_codes)
2423 Common Alias(Wpedantic)
2426 Common Var(flag_pedantic_errors)
2427 Like -pedantic but issue them as errors
2433 Driver Var(use_pipes)
2436 Driver JoinedOrMissing Var(print_file_name)
2438 print-libgcc-file-name
2441 print-multi-directory
2442 Driver Var(print_multi_directory)
2445 Driver Var(print_multi_lib)
2447 print-multi-os-directory
2448 Driver Var(print_multi_os_directory)
2451 Driver Var(print_multiarch)
2454 Driver JoinedOrMissing Var(print_prog_name)
2457 Driver Var(print_search_dirs)
2460 Driver Var(print_sysroot)
2462 print-sysroot-headers-suffix
2463 Driver Var(print_sysroot_headers_suffix)
2466 Common Var(quiet_flag) RejectDriver
2467 Do not display functions compiled or elapsed time
2485 Driver Var(report_times)
2488 Driver JoinedOrMissing
2491 Driver Joined Separate
2495 ; C option, but driver must not handle as "-u ndef".
2498 Common Driver Var(verbose_flag)
2499 Enable verbose output
2502 Common Var(version_flag) RejectDriver
2503 Display the compiler's version
2506 Common Var(inhibit_warnings)
2510 Driver Separate Var(wrapper_string)
2513 Driver Joined Separate
2516 Driver RejectNegative Negative(pie)
2517 Create a shared library
2523 Driver Separate Alias(specs=)
2536 ; Documented for Fortran, but always accepted by driver.
2543 ; Documented for Go, but always accepted by driver.
2555 Driver RejectNegative Negative(shared)
2556 Create a position independent executable
2559 Driver Joined Separate
2561 ; This comment is to ensure we retain the blank line above.