1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 ; Free Software Foundation, Inc.
6 ; This file is part of GCC.
8 ; GCC is free software; you can redistribute it and/or modify it under
9 ; the terms of the GNU General Public License as published by the Free
10 ; Software Foundation; either version 3, or (at your option) any later
13 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 ; You should have received a copy of the GNU General Public License
19 ; along with GCC; see the file COPYING3. If not see
20 ; <http://www.gnu.org/licenses/>.
22 ; See the GCC internals manual (options.texi) for a description of this file's format.
24 ; Please try to keep this file in ASCII collating order.
35 ; Not used directly to control optimizations, only to save -Ofast
36 ; setting for "optimize" attributes.
40 ; True if this is the lto front end. This is used to disable gimple
41 ; generation and lowering passes that are normally run on the output
42 ; of a front end. These passes must be bypassed for lto since they
43 ; have already been done before the gimple was written.
47 ; 0 means straightforward implementation of complex divide acceptable.
48 ; 1 means wide ranges of inputs must work for complex divide.
49 ; 2 means C99-like requirements for complex multiply and divide.
51 int flag_complex_method = 1
53 ; Nonzero if subexpressions must be evaluated from left-to-right.
55 int flag_evaluation_order = 0
57 ; Language specific warning pass for unused results.
59 bool flag_warn_unused_result = false
64 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
68 ; True to warn about any objects definitions whose size is larger
69 ; than N bytes. Also want about function definitions whose returned
70 ; values are larger than N bytes, where N is 'larger_than_size'.
75 HOST_WIDE_INT larger_than_size
77 ; True to warn about any function whose frame size is larger
80 bool warn_frame_larger_than
83 HOST_WIDE_INT frame_larger_than_size
85 ; Nonzero means we should be saving declaration info into a .X file.
87 int flag_gen_aux_info = 0
89 ; Nonzero if we are compiling code for a shared library, zero for
94 ; These two are really VEC(char_p,heap) *.
97 void *flag_instrument_functions_exclude_functions
100 void *flag_instrument_functions_exclude_files
102 ; Generic structs (e.g. templates not explicitly specialized)
103 ; may not have a compilation unit associated with them, and so
104 ; may need to be treated differently from ordinary structs.
106 ; Structs only handled by reference (indirectly), will also usually
107 ; not need as much debugging information.
110 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
113 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 ; True if we should exit after parsing options.
117 bool exit_after_options
119 ; Type(s) of debugging information we are producing (if any). See
120 ; flag-types.h for the definitions of the different possible types of
121 ; debugging information.
123 enum debug_info_type write_symbols = NO_DEBUG
125 ; Level of debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
130 ; Nonzero means use GNU-only extensions in the generated symbolic
131 ; debugging information. Currently, this only has an effect when
132 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
134 bool use_gnu_debug_info_extensions
136 ; Original value of maximum field alignment in bytes, specified via
137 ; -fpack-struct=<value>.
139 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
142 enum vect_verbosity_levels user_vect_verbosity_level = MAX_VERBOSITY_LEVEL
144 ; Type of stack check.
146 enum stack_check_type flag_stack_check = NO_STACK_CHECK
148 ; True if stack usage information needs to be computed.
150 bool flag_stack_usage_info = false
152 ; -dA causes debug commentary information to be produced in
153 ; the generated assembly code (to make it more readable). This option
154 ; is generally only of use to those who actually need to read the
155 ; generated assembly code (perhaps while debugging the compiler itself).
156 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
157 ; to be a catchall for printing debug information in the assembler file.
161 ; -dP causes the rtl to be emitted as a comment in assembly.
163 int flag_dump_rtl_in_asm
165 ; Whether -da was passed (used only in handle_common_deferred_options).
167 bool flag_dump_all_passed
169 ; Other flags saying which kinds of debugging dump have been requested.
172 int rtl_dump_and_exit
175 int flag_print_asm_name
178 enum graph_dump_types graph_dump_format = no_graph
180 ; Name of top-level original source file (what was input to cpp).
181 ; This comes from the #-command at the beginning of the actual input.
182 ; If there isn't any there, then this is the cc1 input file name.
184 const char *main_input_filename
186 ; Pointer to base name in main_input_filename, with directories and a
187 ; single final extension removed, and the length of this base
191 const char *main_input_basename
194 int main_input_baselength
196 ; Which options have been printed by --help.
200 ; Which enums have been printed by --help. 0 = not printed, no
201 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
204 char *help_enum_printed
206 ; The number of columns for --help output.
208 unsigned int help_columns
210 ; Whether this options structure has been through finish_options
212 bool flag_opts_finished
224 Driver Alias(coverage)
230 Common Separate Alias(d)
233 Common Joined Alias(d)
236 Common Separate Alias(dumpbase)
239 Common Separate Alias(dumpdir)
242 Driver Separate Alias(e)
245 Driver Joined Alias(e)
248 Common Warning Alias(Wextra)
251 Driver Separate Alias(Xassembler)
254 Driver JoinedOrMissing Alias(Xassembler)
257 Driver Separate Alias(Xlinker)
260 Driver JoinedOrMissing Alias(Xlinker)
263 Driver Separate Alias(u)
266 Driver Joined Alias(u)
269 Common Driver Var(help_flag)
270 Display this information
273 Common Driver Report Joined
274 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
277 Driver Separate Alias(x)
280 Driver Joined Alias(x)
283 Driver Separate Alias(L)
286 Driver Joined Alias(L)
288 -no-canonical-prefixes
289 Driver Alias(no-canonical-prefixes)
291 -no-standard-libraries
292 Driver Alias(nostdlib)
301 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
304 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
307 Driver Alias(pass-exit-codes)
310 Common Alias(pedantic)
313 Common Alias(pedantic-errors)
322 Driver Separate Alias(B)
325 Driver JoinedOrMissing Alias(B)
331 Driver Separate Alias(print-file-name=)
334 Driver JoinedOrMissing Alias(print-file-name=)
336 -print-libgcc-file-name
337 Driver Alias(print-libgcc-file-name)
339 -print-multi-directory
340 Driver Alias(print-multi-directory)
343 Driver Alias(print-multi-lib)
345 -print-multi-os-directory
346 Driver Alias(print-multi-os-directory)
349 Driver Separate Alias(print-prog-name=)
352 Driver JoinedOrMissing Alias(print-prog-name=)
355 Driver Alias(print-search-dirs)
358 Driver Alias(print-sysroot)
360 -print-sysroot-headers-suffix
361 Driver Alias(print-sysroot-headers-suffix)
367 Driver Alias(save-temps)
373 Driver Separate Alias(specs=)
376 Driver Joined Alias(specs=)
382 Driver Alias(symbolic)
386 Alias for --help=target
394 ;; The driver used to convert options such as --help into forms such
395 ;; as -fhelp; the following four entries are for compatibility with
396 ;; any direct uses of those (undocumented) -f forms
398 Common Driver Alias(-help)
401 Common Driver Joined Alias(-help=)
404 Common Driver Alias(-target-help)
407 Common Driver Alias(-version)
411 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
414 Common Joined Alias(-param)
417 Driver Separate Alias(-sysroot=)
420 Driver JoinedOrMissing
426 Driver Joined Separate
432 Driver Joined Separate
438 Common JoinedOrMissing Optimization
439 -O<number> Set optimization level to <number>
443 Optimize for space rather than speed
447 Optimize for speed disregarding exact standards compliance
459 Driver Joined Separate
465 Driver Joined Separate
486 Common RejectNegative Warning Alias(Wextra)
487 This switch is deprecated; use -Wextra instead
490 Driver JoinedOrMissing
493 Driver JoinedOrMissing
496 Driver JoinedOrMissing
499 Common Var(warn_aggregate_return) Warning
500 Warn about returning structures, unions or arrays
503 Common Var(warn_array_bounds) Warning
504 Warn if an array is accessed out of bounds
507 Common Var(warn_attributes) Init(1) Warning
508 Warn about inappropriate attribute usage
511 Common Var(warn_cast_align) Warning
512 Warn about pointer casts which increase alignment
515 Common Var(warn_cpp) Init(1) Warning
516 Warn when a #warning directive is encountered
518 Wdeprecated-declarations
519 Common Var(warn_deprecated_decl) Init(1) Warning
520 Warn about uses of __attribute__((deprecated)) declarations
522 Wdisabled-optimization
523 Common Var(warn_disabled_optimization) Warning
524 Warn when an optimization pass is disabled
527 Common Var(warnings_are_errors)
528 Treat all warnings as errors
532 Treat specified warning as error
535 Common Var(extra_warnings) Warning
536 Print extra (possibly unwanted) warnings
539 Common Var(flag_fatal_errors)
540 Exit on the first error occurred
543 Common RejectNegative Joined UInteger
544 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
547 Common Var(warn_inline) Warning
548 Warn when an inlined function cannot be inlined
551 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
554 Common RejectNegative Joined UInteger Warning
555 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
557 Wunsafe-loop-optimizations
558 Common Var(warn_unsafe_loop_optimizations) Warning
559 Warn if the loop cannot be optimized due to nontrivial assumptions.
562 Common Var(warn_missing_noreturn) Warning
563 Warn about functions which might be candidates for __attribute__((noreturn))
566 Common Var(warn_mudflap) Init(1) Warning
567 Warn about constructs not instrumented by -fmudflap
570 Common Var(warn_overflow) Init(1) Warning
571 Warn about overflow in arithmetic expressions
574 Common Var(warn_packed) Warning
575 Warn when the packed attribute has no effect on struct layout
578 Common Var(warn_padded) Warning
579 Warn when padding is required to align structure members
582 Common Var(warn_shadow) Warning
583 Warn when one local variable shadows another
586 Common Var(warn_stack_protect) Warning
587 Warn when not issuing stack smashing protection for some reason
590 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
591 Warn if stack usage might be larger than specified amount
595 Warn about code which might break strict aliasing rules
598 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Init(-1) Warning
599 Warn about code which might break strict aliasing rules
603 Warn about optimizations that assume that signed overflow is undefined
606 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Init(-1) Warning
607 Warn about optimizations that assume that signed overflow is undefined
609 Wsuggest-attribute=const
610 Common Var(warn_suggest_attribute_const) Warning
611 Warn about functions which might be candidates for __attribute__((const))
613 Wsuggest-attribute=pure
614 Common Var(warn_suggest_attribute_pure) Warning
615 Warn about functions which might be candidates for __attribute__((pure))
617 Wsuggest-attribute=noreturn
618 Common Var(warn_suggest_attribute_noreturn) Warning
619 Warn about functions which might be candidates for __attribute__((noreturn))
622 Common Var(warn_switch) Warning
623 Warn about enumerated switches, with no default, missing a case
626 Common Var(warn_switch_default) Warning
627 Warn about enumerated switches missing a \"default:\" statement
630 Common Var(warn_switch_enum) Warning
631 Warn about all enumerated switches missing a specific case
634 Common Var(warn_system_headers) Warning
635 Do not suppress warnings from system headers
638 Common Var(warn_trampolines) Warning
639 Warn whenever a trampoline is generated
642 Common Var(warn_type_limits) Init(-1) Warning
643 Warn if a comparison is always true or always false due to the limited range of the data type
646 Common Var(warn_uninitialized) Init(-1) Warning
647 Warn about uninitialized automatic variables
650 Common Var(warn_maybe_uninitialized) Warning
651 Warn about maybe uninitialized automatic variables
655 Does nothing. Preserved for backward compatibility.
658 Common Var(warn_unused) Init(0) Warning
659 Enable all -Wunused- warnings
661 Wunused-but-set-parameter
662 Common Var(warn_unused_but_set_parameter) Init(-1) Warning
663 Warn when a function parameter is only set, otherwise unused
665 Wunused-but-set-variable
666 Common Var(warn_unused_but_set_variable) Init(-1) Warning
667 Warn when a variable is only set, otherwise unused
670 Common Var(warn_unused_function) Init(-1) Warning
671 Warn when a function is unused
674 Common Var(warn_unused_label) Init(-1) Warning
675 Warn when a label is unused
678 Common Var(warn_unused_parameter) Init(-1) Warning
679 Warn when a function parameter is unused
682 Common Var(warn_unused_value) Init(-1) Warning
683 Warn when an expression value is unused
686 Common Var(warn_unused_variable) Init(-1) Warning
687 Warn when a variable is unused
690 Common Var(warn_coverage_mismatch) Init(1) Warning
691 Warn in case profiles in -fprofile-use do not match
706 Common Separate Var(aux_info_file_name)
707 -aux-info <file> Emit declaration information into <file>
710 Common Joined Alias(aux-info)
713 Common Separate RejectDriver Var(aux_base_name)
716 Common Separate RejectDriver
726 -d<letters> Enable dumps from specific passes of the compiler
729 Common Separate Var(dump_base_name)
730 -dumpbase <file> Set the file basename to be used for dumps
733 Common Separate Var(dump_dir_name)
734 -dumpdir <dir> Set the directory name to be used for dumps
746 Driver Joined Separate
748 ; This option has historically been passed down to the linker by an
749 ; accident of a %{e*} spec, so ensure it continues to be passed down
750 ; as a single option. The supported option for this purpose is
751 ; -rdynamic. See PR 47390.
755 ; The version of the C++ ABI in use. The following values are allowed:
757 ; 0: The version of the ABI believed most conformant with the C++ ABI
758 ; specification. This ABI may change as bugs are discovered and fixed.
759 ; Therefore, 0 will not necessarily indicate the same ABI in different
762 ; 1: The version of the ABI first used in G++ 3.2.
764 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
766 ; 3: The version of the ABI that fixes the missing underscore
767 ; in template non-type arguments of pointer type.
769 ; 4: The version of the ABI that introduces unambiguous mangling of
770 ; vector types. First selectable in G++ 4.5.
772 ; 5: The version of the ABI that ignores attribute const/noreturn
773 ; in function pointer mangling, and corrects mangling of decltype and
774 ; function parameters used in other parameters and the return type.
775 ; First selectable in G++ 4.6.
777 ; 6: The version of the ABI that doesn't promote scoped enums to int.
778 ; First selectable in G++ 4.7.
780 ; Additional positive integers will be assigned as new versions of
781 ; the ABI become the default version of the ABI.
783 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
786 Common Report Var(align_functions,0) Optimization UInteger
787 Align the start of functions
790 Common RejectNegative Joined UInteger Var(align_functions)
793 Common Report Var(align_jumps,0) Optimization UInteger
794 Align labels which are only reached by jumping
797 Common RejectNegative Joined UInteger Var(align_jumps)
800 Common Report Var(align_labels,0) Optimization UInteger
804 Common RejectNegative Joined UInteger Var(align_labels)
807 Common Report Var(align_loops,0) Optimization UInteger
808 Align the start of loops
811 Common RejectNegative Joined UInteger Var(align_loops)
815 Does nothing. Preserved for backward compatibility.
819 Does nothing. Preserved for backward compatibility.
821 fargument-noalias-global
823 Does nothing. Preserved for backward compatibility.
825 fargument-noalias-anything
827 Does nothing. Preserved for backward compatibility.
829 fasynchronous-unwind-tables
830 Common Report Var(flag_asynchronous_unwind_tables) Optimization
831 Generate unwind tables that are exact at each instruction boundary
834 Common Report Var(flag_auto_inc_dec) Init(1)
835 Generate auto-inc/dec instructions
837 ; -fcheck-bounds causes gcc to generate array bounds checks.
838 ; For C, C++ and ObjC: defaults off.
839 ; For Java: defaults to on.
840 ; For Fortran: defaults to off.
842 Common Report Var(flag_bounds_check)
843 Generate code to check bounds before indexing arrays
846 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
847 Replace add, compare, branch with branch on count register
849 fbranch-probabilities
850 Common Report Var(flag_branch_probabilities) Optimization
851 Use profiling information for branch probabilities
853 fbranch-target-load-optimize
854 Common Report Var(flag_branch_target_load_optimize) Optimization
855 Perform branch target load optimization before prologue / epilogue threading
857 fbranch-target-load-optimize2
858 Common Report Var(flag_branch_target_load_optimize2) Optimization
859 Perform branch target load optimization after prologue / epilogue threading
862 Common Report Var(flag_btr_bb_exclusive) Optimization
863 Restrict target load migration not to re-use registers in any basic block
866 Common Joined RejectNegative Var(common_deferred_options) Defer
867 -fcall-saved-<register> Mark <register> as being preserved across functions
870 Common Joined RejectNegative Var(common_deferred_options) Defer
871 -fcall-used-<register> Mark <register> as being corrupted by function calls
873 ; Nonzero for -fcaller-saves: allocate values in regs that need to
874 ; be saved across function calls, if that produces overall better code.
875 ; Optional now, so people can test it.
877 Common Report Var(flag_caller_saves) Optimization
878 Save registers around function calls
881 Common Report Var(flag_check_data_deps)
882 Compare the results of several data dependence analyzers.
884 fcombine-stack-adjustments
885 Common Report Var(flag_combine_stack_adjustments) Optimization
886 Looks for opportunities to reduce stack adjustments and stack references.
889 Common Report Var(flag_no_common,0) Optimization
890 Do not put uninitialized globals in the common section
894 ; Converted by the driver to -fcompare-debug= options.
897 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
898 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
900 fcompare-debug-second
901 Common Driver RejectNegative Var(flag_compare_debug)
902 Run only the second compilation of -fcompare-debug
905 Common Report Var(flag_compare_elim_after_reload) Optimization
906 Perform comparison elimination after register allocation has finished
909 Common Var(flag_conserve_stack) Optimization
910 Do not perform optimizations increasing noticeably stack usage
913 Common Report Var(flag_cprop_registers) Optimization
914 Perform a register copy-propagation optimization pass
917 Common Report Var(flag_crossjumping) Optimization
918 Perform cross-jumping optimization
921 Common Report Var(flag_cse_follow_jumps) Optimization
922 When running CSE, follow jumps to their targets
926 Does nothing. Preserved for backward compatibility.
929 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
930 Omit range reduction step when performing complex division
933 Common Report Var(flag_cx_fortran_rules) Optimization
934 Complex multiplication and division follow Fortran rules
937 Common Report Var(flag_data_sections) Optimization
938 Place data items into their own section
941 Common Report Var(common_deferred_options) Defer
942 List all available debugging counters with their limits and counts.
945 Common RejectNegative Joined Var(common_deferred_options) Defer
946 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
949 Common Joined RejectNegative Var(common_deferred_options) Defer
950 Map one directory name to another in debug information
953 Common Report Var(flag_debug_types_section) Init(1)
954 Output .debug_types section when using DWARF v4 debuginfo.
956 ; Nonzero for -fdefer-pop: don't pop args after each function call
957 ; instead save them up to pop many calls' args with one insns.
959 Common Report Var(flag_defer_pop) Optimization
960 Defer popping functions args from stack until later
963 Common Report Var(flag_delayed_branch) Optimization
964 Attempt to fill delay slots of branch instructions
966 fdelete-null-pointer-checks
967 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
968 Delete useless null pointer checks
971 Common Report Var(flag_devirtualize) Optimization
972 Try to convert virtual calls to direct ones.
974 fdiagnostics-show-location=
975 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
976 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
978 ; Required for these enum values.
983 Name(diagnostic_prefixing_rule) Type(int)
986 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
989 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
991 fdiagnostics-show-option
992 Common Var(flag_diagnostics_show_option) Init(1)
993 Amend appropriate diagnostic messages with the command line option that controls them
996 Common Joined RejectNegative Var(common_deferred_options) Defer
997 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1000 Common Joined RejectNegative Var(common_deferred_options) Defer
1001 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1004 Common Joined RejectNegative Var(common_deferred_options) Defer
1005 -fdump-<type> Dump various compiler internals to a file
1008 Driver RejectNegative
1011 Common RejectNegative Joined Var(flag_dump_final_insns)
1012 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1015 Common RejectNegative Joined Var(flag_dump_go_spec)
1016 -fdump-go-spec=filename Write all declarations to file as Go code
1019 Common Report Var(flag_dump_noaddr)
1020 Suppress output of addresses in debugging dumps
1023 Common Var(flag_dump_passes) Init(0)
1024 Dump optimization passes
1027 Common Report Var(flag_dump_unnumbered)
1028 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1030 fdump-unnumbered-links
1031 Common Report Var(flag_dump_unnumbered_links)
1032 Suppress output of previous and next insn numbers in debugging dumps
1035 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1036 Enable CFI tables via GAS assembler directives.
1039 Common Report Var(flag_early_inlining) Init(1) Optimization
1040 Perform early inlining
1042 feliminate-dwarf2-dups
1043 Common Report Var(flag_eliminate_dwarf2_dups)
1044 Perform DWARF2 duplicate elimination
1047 Common Report Var(flag_ipa_sra) Init(0) Optimization
1048 Perform interprocedural reduction of aggregates
1050 feliminate-unused-debug-symbols
1051 Common Report Var(flag_debug_only_used_symbols)
1052 Perform unused type elimination in debug info
1054 feliminate-unused-debug-types
1055 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1056 Perform unused type elimination in debug info
1058 femit-class-debug-always
1059 Common Report Var(flag_emit_class_debug_always) Init(0)
1060 Do not suppress C++ class debug information.
1063 Common Report Var(flag_exceptions) Optimization
1064 Enable exception handling
1066 fexpensive-optimizations
1067 Common Report Var(flag_expensive_optimizations) Optimization
1068 Perform a number of minor, expensive optimizations
1071 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1072 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1075 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1078 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1081 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1087 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1088 Assume no NaNs or infinities are generated
1091 Common Joined RejectNegative Var(common_deferred_options) Defer
1092 -ffixed-<register> Mark <register> as being unavailable to the compiler
1095 Common Report Var(flag_float_store) Optimization
1096 Don't allocate floats and doubles in extended-precision registers
1100 Does nothing. Preserved for backward compatibility.
1103 Common Report Var(flag_forward_propagate) Optimization
1104 Perform a forward propagation pass on RTL
1107 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1108 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1111 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1114 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1116 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1118 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1121 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1123 ; Nonzero means don't put addresses of constant functions in registers.
1124 ; Used for compiling the Unix kernel, where strange substitutions are
1125 ; done on the assembly output.
1127 Common Report Var(flag_no_function_cse,0)
1128 Allow function addresses to be held in registers
1131 Common Report Var(flag_function_sections)
1132 Place each function into its own section
1135 Common Report Var(flag_gcse) Optimization
1136 Perform global common subexpression elimination
1139 Common Report Var(flag_gcse_lm) Init(1) Optimization
1140 Perform enhanced load motion during global common subexpression elimination
1143 Common Report Var(flag_gcse_sm) Init(0) Optimization
1144 Perform store motion after global common subexpression elimination
1147 Common Report Var(flag_gcse_las) Init(0) Optimization
1148 Perform redundant load after store elimination in global common subexpression
1152 Common Report Var(flag_gcse_after_reload) Optimization
1153 Perform global common subexpression elimination after register allocation
1156 ; This option is not documented yet as its semantics will change.
1158 Common Report Var(flag_graphite)
1159 Enable in and out of Graphite representation
1162 Common Report Var(flag_graphite_identity) Optimization
1163 Enable Graphite Identity transformation
1165 floop-parallelize-all
1166 Common Report Var(flag_loop_parallelize_all) Optimization
1167 Mark all loops as parallel
1170 Common Report Var(flag_loop_strip_mine) Optimization
1171 Enable Loop Strip Mining transformation
1174 Common Report Var(flag_loop_interchange) Optimization
1175 Enable Loop Interchange transformation
1178 Common Report Var(flag_loop_block) Optimization
1179 Enable Loop Blocking transformation
1182 Common Report Var(flag_loop_flatten) Optimization
1183 Enable Loop Flattening transformation
1185 fstrict-volatile-bitfields
1186 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1187 Force bitfield accesses to match their type width
1189 fguess-branch-probability
1190 Common Report Var(flag_guess_branch_prob) Optimization
1191 Enable guessing of branch probabilities
1193 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1194 ; Generate position-independent code for executables if possible
1195 ; On SVR4 targets, it also controls whether or not to emit a
1196 ; string identifying the compiler.
1198 Common Report Var(flag_no_ident,0)
1199 Process #ident directives
1202 Common Report Var(flag_if_conversion) Optimization
1203 Perform conversion of conditional jumps to branchless equivalents
1206 Common Report Var(flag_if_conversion2) Optimization
1207 Perform conversion of conditional jumps to conditional execution
1209 ftree-loop-if-convert
1210 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1211 Convert conditional jumps in innermost loops to branchless equivalents
1213 ftree-loop-if-convert-stores
1214 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1215 Also if-convert conditional jumps containing memory writes
1217 ; -finhibit-size-directive inhibits output of .size for ELF.
1218 ; This is used only for compiling crtstuff.c,
1219 ; and it may be extended to other effects
1220 ; needed for crtstuff.c on other systems.
1221 finhibit-size-directive
1222 Common Report Var(flag_inhibit_size_directive)
1223 Do not generate .size directives
1226 Common Report Var(flag_indirect_inlining)
1227 Perform indirect inlining
1229 ; Nonzero means that functions declared `inline' will be treated
1230 ; as `static'. Prevents generation of zillions of copies of unused
1231 ; static inline functions; instead, `inlines' are written out
1232 ; only when actually used. Used in conjunction with -g. Also
1233 ; does the right thing with #pragma interface.
1235 Common Report Var(flag_no_inline,0) Init(0)
1236 Pay attention to the \"inline\" keyword
1238 finline-small-functions
1239 Common Report Var(flag_inline_small_functions) Optimization
1240 Integrate simple functions into their callers when code size is known to not growth
1243 Common Report Var(flag_inline_functions) Optimization
1244 Integrate simple functions into their callers
1246 finline-functions-called-once
1247 Common Report Var(flag_inline_functions_called_once) Optimization
1248 Integrate functions called once into their callers
1251 Common RejectNegative Joined Alias(finline-limit=)
1254 Common RejectNegative Joined UInteger
1255 -finline-limit=<number> Limit the size of inlined functions to <number>
1257 finstrument-functions
1258 Common Report Var(flag_instrument_function_entry_exit)
1259 Instrument function entry and exit with profiling calls
1261 finstrument-functions-exclude-function-list=
1262 Common RejectNegative Joined
1263 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1265 finstrument-functions-exclude-file-list=
1266 Common RejectNegative Joined
1267 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1270 Common Report Var(flag_ipa_cp) Optimization
1271 Perform Interprocedural constant propagation
1274 Common Report Var(flag_ipa_cp_clone) Optimization
1275 Perform cloning to make Interprocedural constant propagation stronger
1278 Common Report Var(flag_ipa_profile) Init(0) Optimization
1279 Perform interprocedural profile propagation
1282 Common Report Var(flag_ipa_pta) Init(0) Optimization
1283 Perform interprocedural points-to analysis
1286 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1287 Discover pure and const functions
1290 Common Report Var(flag_ipa_reference) Init(0) Optimization
1291 Discover readonly and non addressable static variables
1294 Common Report Var(flag_ipa_matrix_reorg) Optimization
1295 Perform matrix layout flattening and transposing based
1296 on profiling information.
1300 Does nothing. Preserved for backward compatibility.
1303 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1304 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1307 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1310 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1313 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1316 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_MIXED)
1317 -fira-region=[one|all|mixed] Set regions for IRA
1320 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1323 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1326 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1329 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1332 Common Report Var(flag_ira_loop_pressure)
1333 Use IRA based register pressure calculation
1334 in RTL loop optimizations.
1336 fira-share-save-slots
1337 Common Report Var(flag_ira_share_save_slots) Init(1)
1338 Share slots for saving different hard registers.
1340 fira-share-spill-slots
1341 Common Report Var(flag_ira_share_spill_slots) Init(1)
1342 Share stack slots for spilled pseudo-registers.
1345 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1346 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1349 Common Report Var(flag_ivopts) Init(1) Optimization
1350 Optimize induction variables on trees
1353 Common Var(flag_jump_tables) Init(1) Optimization
1354 Use jump tables for sufficiently large switch statements
1356 fkeep-inline-functions
1357 Common Report Var(flag_keep_inline_functions)
1358 Generate code for functions even if they are fully inlined
1361 Common Report Var(flag_keep_static_consts) Init(1)
1362 Emit static const variables even if they are not used
1365 Common Report Var(flag_leading_underscore) Init(-1)
1366 Give external symbols a leading underscore
1370 Does nothing. Preserved for backward compatibility.
1374 Enable link-time optimization.
1377 Common RejectNegative Joined Var(flag_lto)
1378 Link-time optimization with number of parallel jobs or jobserver.
1381 Common Var(flag_lto_partition_1to1)
1382 Partition functions and vars at linktime based on object files they originate from
1384 flto-partition=balanced
1385 Common Var(flag_lto_partition_balanced)
1386 Partition functions and vars at linktime into approximately same sized buckets
1389 Common Var(flag_lto_partition_none)
1390 Disable partioning and streaming
1392 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1393 flto-compression-level=
1394 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1395 -flto-compression-level=<number> Use zlib compression level <number> for IL
1398 Common Report Var(flag_lto_report) Init(0) Optimization
1399 Report various link-time optimization statistics
1402 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1403 Set errno after built-in math functions
1406 Common Joined RejectNegative UInteger Var(flag_max_errors)
1407 -fmax-errors=<number> Maximum number of errors to report
1410 Common Report Var(mem_report)
1411 Report on permanent memory allocation
1413 ; This will attempt to merge constant section constants, if 1 only
1414 ; string constants and constants from constant pool, if 2 also constant
1416 fmerge-all-constants
1417 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1418 Attempt to merge identical constants and constant variables
1421 Common Report Var(flag_merge_constants,1) Optimization
1422 Attempt to merge identical constants across compilation units
1424 fmerge-debug-strings
1425 Common Report Var(flag_merge_debug_strings) Init(1)
1426 Attempt to merge identical debug strings across compilation units
1429 Common RejectNegative Joined UInteger
1430 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1433 Common Report Var(flag_modulo_sched) Optimization
1434 Perform SMS based modulo scheduling before the first scheduling pass
1436 fmodulo-sched-allow-regmoves
1437 Common Report Var(flag_modulo_sched_allow_regmoves)
1438 Perform SMS based modulo scheduling with register moves allowed
1440 fmove-loop-invariants
1441 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1442 Move loop invariant computations out of loops
1445 Common RejectNegative Report Var(flag_mudflap)
1446 Add mudflap bounds-checking instrumentation for single-threaded program
1449 Common RejectNegative Report Var(flag_mudflap,2)
1450 Add mudflap bounds-checking instrumentation for multi-threaded program
1453 Common RejectNegative Report Var(flag_mudflap_ignore_reads)
1454 Ignore read operations when inserting mudflap instrumentation
1457 Common Var(flag_dce) Init(1) Optimization
1458 Use the RTL dead code elimination pass
1461 Common Var(flag_dse) Init(1) Optimization
1462 Use the RTL dead store elimination pass
1464 freschedule-modulo-scheduled-loops
1465 Common Report Var(flag_resched_modulo_sched) Optimization
1466 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1468 fnon-call-exceptions
1469 Common Report Var(flag_non_call_exceptions) Optimization
1470 Support synchronous non-call exceptions
1473 Common Report Var(flag_omit_frame_pointer) Optimization
1474 When possible do not generate stack frames
1476 foptimize-register-move
1477 Common Report Var(flag_regmove) Optimization
1478 Do the full register move optimization pass
1480 foptimize-sibling-calls
1481 Common Report Var(flag_optimize_sibling_calls) Optimization
1482 Optimize sibling and tail recursive calls
1485 Common Report Var(flag_partial_inlining)
1486 Perform partial inlining
1489 Common Report Var(pre_ipa_mem_report)
1490 Report on memory allocation before interprocedural optimization
1492 fpost-ipa-mem-report
1493 Common Report Var(post_ipa_mem_report)
1494 Report on memory allocation before interprocedural optimization
1497 Common Report Var(flag_pack_struct) Optimization
1498 Pack structure members together without holes
1501 Common RejectNegative Joined UInteger Optimization
1502 -fpack-struct=<number> Set initial maximum structure member alignment
1505 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1506 Return small aggregates in memory, not registers
1509 Common Report Var(flag_peel_loops) Optimization
1510 Perform loop peeling
1513 Common Report Var(flag_no_peephole,0) Optimization
1514 Enable machine specific peephole optimizations
1517 Common Report Var(flag_peephole2) Optimization
1518 Enable an RTL peephole pass before sched2
1521 Common Report Var(flag_pic,2)
1522 Generate position-independent code if possible (large mode)
1525 Common Report Var(flag_pie,2)
1526 Generate position-independent code for executables if possible (large mode)
1529 Common Report Var(flag_pic,1)
1530 Generate position-independent code if possible (small mode)
1533 Common Report Var(flag_pie,1)
1534 Generate position-independent code for executables if possible (small mode)
1537 Common Joined RejectNegative Var(common_deferred_options) Defer
1538 Specify a plugin to load
1541 Common Joined RejectNegative Var(common_deferred_options) Defer
1542 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1544 fpredictive-commoning
1545 Common Report Var(flag_predictive_commoning) Optimization
1546 Run predictive commoning optimization.
1548 fprefetch-loop-arrays
1549 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1550 Generate prefetch instructions, if available, for arrays in loops
1553 Common Report Var(profile_flag)
1554 Enable basic program profiling code
1557 Common Report Var(profile_arc_flag)
1558 Insert arc-based program profiling code
1561 Common Joined RejectNegative Var(profile_data_prefix)
1562 Set the top-level directory for storing the profile data.
1563 The default is 'pwd'.
1566 Common Report Var(flag_profile_correction)
1567 Enable correction of flow inconsistent profile data input
1571 Enable common options for generating profile info for profile feedback directed optimizations
1574 Common Joined RejectNegative
1575 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1578 Common Var(flag_profile_use)
1579 Enable common options for performing profile feedback directed optimizations
1582 Common Joined RejectNegative
1583 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1586 Common Report Var(flag_profile_values)
1587 Insert code to profile values of expressions
1590 Common Var(common_deferred_options) Defer
1593 Common Joined RejectNegative Var(common_deferred_options) Defer
1594 -frandom-seed=<string> Make compile reproducible using <string>
1596 ; This switch causes the command line that was used to create an
1597 ; object file to be recorded into the object file. The exact format
1598 ; of this recording is target and binary file format dependent.
1599 ; It is related to the -fverbose-asm switch, but that switch only
1600 ; records information in the assembler output file as comments, so
1601 ; they never reach the object file.
1602 frecord-gcc-switches
1603 Common Report Var(flag_record_gcc_switches)
1604 Record gcc command line switches in the object file.
1607 Common Report Var(flag_pcc_struct_return,0) Optimization
1608 Return small aggregates in registers
1611 Common Report Var(flag_regmove) Optimization
1612 Enables a register move optimization
1615 Common Report Var(flag_rename_registers) Init(2) Optimization
1616 Perform a register renaming optimization pass
1619 Common Report Var(flag_reorder_blocks) Optimization
1620 Reorder basic blocks to improve code placement
1622 freorder-blocks-and-partition
1623 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1624 Reorder basic blocks and partition into hot and cold sections
1627 Common Report Var(flag_reorder_functions) Optimization
1628 Reorder functions to improve code placement
1630 frerun-cse-after-loop
1631 Common Report Var(flag_rerun_cse_after_loop) Optimization
1632 Add a common subexpression elimination pass after loop optimizations
1636 Does nothing. Preserved for backward compatibility.
1639 Common Report Var(flag_rounding_math) Optimization SetByCombined
1640 Disable optimizations that assume default FP rounding behavior
1643 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1644 Enable scheduling across basic blocks
1647 Common Report Var(flag_sched_pressure) Init(0) Optimization
1648 Enable register pressure sensitive insn scheduling
1651 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1652 Allow speculative motion of non-loads
1655 Common Report Var(flag_schedule_speculative_load) Optimization
1656 Allow speculative motion of some loads
1658 fsched-spec-load-dangerous
1659 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1660 Allow speculative motion of more loads
1663 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1664 -fsched-verbose=<number> Set the verbosity level of the scheduler
1666 fsched2-use-superblocks
1667 Common Report Var(flag_sched2_use_superblocks) Optimization
1668 If scheduling post reload, do superblock scheduling
1672 Does nothing. Preserved for backward compatibility.
1675 Common Report Var(flag_schedule_insns) Optimization
1676 Reschedule instructions before register allocation
1679 Common Report Var(flag_schedule_insns_after_reload) Optimization
1680 Reschedule instructions after register allocation
1682 ; This flag should be on when a target implements non-trivial
1683 ; scheduling hooks, maybe saving some information for its own sake.
1684 ; On IA64, for example, this is used for correct bundling.
1685 fselective-scheduling
1686 Common Report Var(flag_selective_scheduling) Optimization
1687 Schedule instructions using selective scheduling algorithm
1689 fselective-scheduling2
1690 Common Report Var(flag_selective_scheduling2) Optimization
1691 Run selective scheduling after reload
1693 fsel-sched-pipelining
1694 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1695 Perform software pipelining of inner loops during selective scheduling
1697 fsel-sched-pipelining-outer-loops
1698 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1699 Perform software pipelining of outer loops during selective scheduling
1701 fsel-sched-reschedule-pipelined
1702 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1703 Reschedule pipelined regions without pipelining
1705 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1706 ; of stalled insns into the ready list.
1707 fsched-stalled-insns
1708 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1709 Allow premature scheduling of queued insns
1711 fsched-stalled-insns=
1712 Common RejectNegative Joined UInteger
1713 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1715 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1716 ; be examined for a dependency on a stalled insn that is candidate for
1717 ; premature removal from the queue of stalled insns into the ready list (has
1718 ; an effect only if the flag 'sched_stalled_insns' is set).
1719 fsched-stalled-insns-dep
1720 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1721 Set dependence distance checking in premature scheduling of queued insns
1723 fsched-stalled-insns-dep=
1724 Common RejectNegative Joined UInteger
1725 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1727 fsched-group-heuristic
1728 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1729 Enable the group heuristic in the scheduler
1731 fsched-critical-path-heuristic
1732 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1733 Enable the critical path heuristic in the scheduler
1735 fsched-spec-insn-heuristic
1736 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1737 Enable the speculative instruction heuristic in the scheduler
1739 fsched-rank-heuristic
1740 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1741 Enable the rank heuristic in the scheduler
1743 fsched-last-insn-heuristic
1744 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1745 Enable the last instruction heuristic in the scheduler
1747 fsched-dep-count-heuristic
1748 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1749 Enable the dependent count heuristic in the scheduler
1752 Common Report Var(flag_section_anchors) Optimization
1753 Access data in the same section from shared anchor points
1757 Does nothing. Preserved for backward compatibility.
1760 Common Report Var(flag_zee) Init(0)
1761 Eliminate redundant zero extensions on targets that support implicit extensions.
1764 Common Report Var(flag_show_column) Init(1)
1765 Show column numbers in diagnostics, when available. Default on
1768 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1769 Disable optimizations observable by IEEE signaling NaNs
1772 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1773 Disable floating point optimizations that ignore the IEEE signedness of zero
1775 fsingle-precision-constant
1776 Common Report Var(flag_single_precision_constant) Optimization
1777 Convert floating point constants to single precision constants
1779 fsplit-ivs-in-unroller
1780 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1781 Split lifetimes of induction variables when loops are unrolled
1784 Common Report Var(flag_split_stack) Init(-1)
1785 Generate discontiguous stack frames
1788 Common Report Var(flag_split_wide_types) Optimization
1789 Split wide types into independent registers
1791 fvariable-expansion-in-unroller
1792 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1793 Apply variable expansion when loops are unrolled
1796 Common Report RejectNegative Joined
1797 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1800 Common Alias(fstack-check=, specific, no)
1801 Insert stack checking code into the program. Same as -fstack-check=specific
1804 Common Var(common_deferred_options) Defer
1806 fstack-limit-register=
1807 Common RejectNegative Joined Var(common_deferred_options) Defer
1808 -fstack-limit-register=<register> Trap if the stack goes past <register>
1810 fstack-limit-symbol=
1811 Common RejectNegative Joined Var(common_deferred_options) Defer
1812 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1815 Common Report Var(flag_stack_protect, 1)
1816 Use propolice as a stack protection method
1818 fstack-protector-all
1819 Common Report RejectNegative Var(flag_stack_protect, 2)
1820 Use a stack protection method for every function
1823 Common RejectNegative Var(flag_stack_usage)
1824 Output stack usage information on a per-function basis
1828 Does nothing. Preserved for backward compatibility.
1830 ; Nonzero if we should do (language-dependent) alias analysis.
1831 ; Typically, this analysis will assume that expressions of certain
1832 ; types do not alias expressions of certain other types. Only used
1833 ; if alias analysis (in general) is enabled.
1835 Common Report Var(flag_strict_aliasing) Optimization
1836 Assume strict aliasing rules apply
1839 Common Report Var(flag_strict_overflow)
1840 Treat signed overflow as undefined
1843 Common Report Var(flag_syntax_only)
1844 Check for syntax errors, then stop
1847 Common Report Var(flag_test_coverage)
1848 Create data files needed by \"gcov\"
1851 Common Report Var(flag_thread_jumps) Optimization
1852 Perform jump threading optimizations
1855 Common Report Var(time_report)
1856 Report the time taken by each compiler pass
1859 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1860 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1863 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1866 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1869 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1872 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1875 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1878 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1879 Reorder top level functions, variables, and asms
1882 Common Report Var(flag_tracer)
1883 Perform superblock formation via tail duplication
1885 ; Zero means that floating-point math operations cannot generate a
1886 ; (user-visible) trap. This is the case, for example, in nonstop
1887 ; IEEE 754 arithmetic.
1889 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1890 Assume floating-point operations can trap
1893 Common Report Var(flag_trapv) Optimization
1894 Trap for signed overflow in addition, subtraction and multiplication
1897 Common Report Var(flag_tree_ccp) Optimization
1898 Enable SSA-CCP optimization on trees
1901 Common Report Var(flag_tree_bit_ccp) Optimization
1902 Enable SSA-BIT-CCP optimization on trees
1906 Does nothing. Preserved for backward compatibility.
1909 Common Report Var(flag_tree_ch) Optimization
1910 Enable loop header copying on trees
1913 Common Report Var(flag_tree_copyrename) Optimization
1914 Replace SSA temporaries with better names in copies
1917 Common Report Var(flag_tree_copy_prop) Optimization
1918 Enable copy propagation on trees
1920 ftree-store-copy-prop
1922 Does nothing. Preserved for backward compatibility.
1925 Common Report Var(flag_tree_cselim) Init(2) Optimization
1926 Transform condition stores into unconditional ones
1928 ftree-switch-conversion
1929 Common Report Var(flag_tree_switch_conversion) Optimization
1930 Perform conversions of switch initializations.
1933 Common Report Var(flag_tree_dce) Optimization
1934 Enable SSA dead code elimination optimization on trees
1936 ftree-dominator-opts
1937 Common Report Var(flag_tree_dom) Optimization
1938 Enable dominator optimizations
1941 Common Report Var(flag_tree_dse) Optimization
1942 Enable dead store elimination
1945 Common Report Var(flag_tree_forwprop) Init(1) Optimization
1946 Enable forward propagation on trees
1949 Common Report Var(flag_tree_fre) Optimization
1950 Enable Full Redundancy Elimination (FRE) on trees
1952 ftree-loop-distribution
1953 Common Report Var(flag_tree_loop_distribution) Optimization
1954 Enable loop distribution on trees
1956 ftree-loop-distribute-patterns
1957 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
1958 Enable loop distribution for patterns transformed into a library call
1961 Common Report Var(flag_tree_loop_im) Init(1) Optimization
1962 Enable loop invariant motion on trees
1965 Common Alias(floop-interchange)
1966 Enable loop interchange transforms. Same as -floop-interchange
1969 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
1970 Create canonical induction variables in loops
1973 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
1974 Enable loop optimizations on tree level
1976 ftree-parallelize-loops=
1977 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
1978 Enable automatic parallelization of loops
1981 Common Report Var(flag_tree_phiprop) Init(1) Optimization
1982 Enable hoisting loads from conditional pointers.
1985 Common Report Var(flag_tree_pre) Optimization
1986 Enable SSA-PRE optimization on trees
1989 Common Report Var(flag_tree_pta) Init(1) Optimization
1990 Perform function-local points-to analysis on trees.
1993 Common Report Var(flag_tree_reassoc) Init(1) Optimization
1994 Enable reassociation on tree level
1998 Does nothing. Preserved for backward compatibility.
2001 Common Report Var(flag_tree_sink) Optimization
2002 Enable SSA code sinking on trees
2005 Common Report Var(flag_tree_sra) Optimization
2006 Perform scalar replacement of aggregates
2009 Common Report Var(flag_tree_ter) Optimization
2010 Replace temporary expressions in the SSA->normal pass
2013 Common Report Var(flag_tree_live_range_split) Optimization
2014 Perform live range splitting during the SSA->normal pass
2017 Common Report Var(flag_tree_vrp) Init(0) Optimization
2018 Perform Value Range Propagation on trees
2021 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2022 Compile whole compilation unit at a time
2025 Common Report Var(flag_unroll_loops) Optimization
2026 Perform loop unrolling when iteration count is known
2029 Common Report Var(flag_unroll_all_loops) Optimization
2030 Perform loop unrolling for all loops
2032 ; Nonzero means that loop optimizer may assume that the induction variables
2033 ; that control loops do not overflow and that the loops with nontrivial
2034 ; exit condition are not infinite
2035 funsafe-loop-optimizations
2036 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2037 Allow loop optimizations to assume that the loops behave in normal way
2040 Common Report Var(flag_associative_math) SetByCombined
2041 Allow optimization for floating-point arithmetic which may change the
2042 result of the operation due to rounding.
2045 Common Report Var(flag_reciprocal_math) SetByCombined
2046 Same as -fassociative-math for expressions which include division.
2048 ; Nonzero means that unsafe floating-point math optimizations are allowed
2049 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2050 ; are allowed to assume that their arguments and results are "normal"
2051 ; (e.g., nonnegative for SQRT).
2052 funsafe-math-optimizations
2053 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2054 Allow math optimizations that may violate IEEE or ISO standards
2057 Common Report Var(flag_unswitch_loops) Optimization
2058 Perform loop unswitching
2061 Common Report Var(flag_unwind_tables) Optimization
2062 Just generate unwind tables for exception handling
2067 ; Positive if we should track variables, negative if we should run
2068 ; the var-tracking pass only to discard debug annotations, zero if
2069 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2070 ; will be set according to optimize, debug_info_level and debug_hooks
2071 ; in process_options ().
2073 Common Report Var(flag_var_tracking) Init(2) Optimization
2074 Perform variable tracking
2076 ; Positive if we should track variables at assignments, negative if
2077 ; we should run the var-tracking pass only to discard debug
2078 ; annotations. When flag_var_tracking_assignments ==
2079 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2080 fvar-tracking-assignments
2081 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2082 Perform variable tracking by annotating assignments
2084 ; Nonzero if we should toggle flag_var_tracking_assignments after
2085 ; processing options and computing its default. */
2086 fvar-tracking-assignments-toggle
2087 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2088 Toggle -fvar-tracking-assignments
2090 fvar-tracking-uninit
2091 Common Report Var(flag_var_tracking_uninit) Optimization
2092 Perform variable tracking and also tag variables that are uninitialized
2095 Common Report Var(flag_tree_vectorize) Optimization
2096 Enable loop vectorization on trees
2099 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2100 Enable basic block vectorization (SLP) on trees
2103 Common Report Var(flag_vect_cost_model) Optimization
2104 Enable use of cost model in vectorization
2106 ftree-vect-loop-version
2107 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2108 Enable loop versioning when doing loop vectorization on trees
2110 ftree-vectorizer-verbose=
2111 Common RejectNegative Joined UInteger
2112 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
2115 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2116 Enable copy propagation of scalar-evolution information.
2118 ; -fverbose-asm causes extra commentary information to be produced in
2119 ; the generated assembly code (to make it more readable). This option
2120 ; is generally only of use to those who actually need to read the
2121 ; generated assembly code (perhaps while debugging the compiler itself).
2122 ; -fno-verbose-asm, the default, causes the extra information
2123 ; to not be added and is useful when comparing two assembler files.
2125 Common Report Var(flag_verbose_asm)
2126 Add extra commentary to assembler output
2129 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2130 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2133 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2136 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2139 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2142 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2145 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2148 Common Report Var(flag_value_profile_transformations) Optimization
2149 Use expression value profiles in optimizations
2152 Common Report Var(flag_web) Init(2) Optimization
2153 Construct webs and split unrelated uses of single variable
2155 ftree-builtin-call-dce
2156 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2157 Enable conditional dead code elimination for builtin calls
2160 Common Report Var(flag_whole_program) Init(0) Optimization
2161 Perform whole program optimizations
2164 Common Report Var(flag_wrapv) Optimization
2165 Assume signed arithmetic overflow wraps around
2167 fzero-initialized-in-bss
2168 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2169 Put zero initialized data in the bss section
2172 Common JoinedOrMissing
2173 Generate debug information in default format
2176 Common JoinedOrMissing Negative(gdwarf-)
2177 Generate debug information in COFF format
2180 Common Joined UInteger Var(dwarf_version) Init(2) Negative(gstabs)
2181 Generate debug information in DWARF v2 (or later) format
2184 Common JoinedOrMissing
2185 Generate debug information in default extended format
2187 gno-record-gcc-switches
2188 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(0)
2189 Don't record gcc command line switches in DWARF DW_AT_producer.
2191 grecord-gcc-switches
2192 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2193 Record gcc command line switches in DWARF DW_AT_producer.
2196 Common JoinedOrMissing Negative(gstabs+)
2197 Generate debug information in STABS format
2200 Common JoinedOrMissing Negative(gvms)
2201 Generate debug information in extended STABS format
2204 Common RejectNegative Var(dwarf_strict,0) Init(-1)
2205 Emit DWARF additions beyond selected version
2208 Common Report RejectNegative Var(dwarf_strict,1)
2209 Don't emit DWARF additions beyond selected version
2212 Common Report Var(flag_gtoggle)
2213 Toggle debug information generation
2216 Common JoinedOrMissing Negative(gxcoff)
2217 Generate debug information in VMS format
2220 Common JoinedOrMissing Negative(gxcoff+)
2221 Generate debug information in XCOFF format
2224 Common JoinedOrMissing Negative(gcoff)
2225 Generate debug information in extended XCOFF format
2228 Driver Joined Separate
2231 Common Joined Var(plugindir_string) Init(0)
2232 -iplugindir=<dir> Set <dir> to be the default plugin directory
2235 Driver Joined Separate
2240 no-canonical-prefixes
2253 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2254 -o <file> Place output into <file>
2257 Common Var(profile_flag)
2258 Enable function profiling
2261 Driver Var(pass_exit_codes)
2264 Common Var(pedantic)
2265 Issue warnings needed for strict compliance to the standard
2268 Common Var(flag_pedantic_errors)
2269 Like -pedantic but issue them as errors
2275 Driver Var(use_pipes)
2278 Driver JoinedOrMissing Var(print_file_name)
2280 print-libgcc-file-name
2283 print-multi-directory
2284 Driver Var(print_multi_directory)
2287 Driver Var(print_multi_lib)
2289 print-multi-os-directory
2290 Driver Var(print_multi_os_directory)
2293 Driver JoinedOrMissing Var(print_prog_name)
2296 Driver Var(print_search_dirs)
2299 Driver Var(print_sysroot)
2301 print-sysroot-headers-suffix
2302 Driver Var(print_sysroot_headers_suffix)
2305 Common Var(quiet_flag) RejectDriver
2306 Do not display functions compiled or elapsed time
2324 Driver Var(report_times)
2327 Driver JoinedOrMissing
2330 Driver Joined Separate
2334 ; C option, but driver must not handle as "-u ndef".
2337 Common Driver Var(verbose_flag)
2338 Enable verbose output
2341 Common Var(version_flag) RejectDriver
2342 Display the compiler's version
2345 Common Var(inhibit_warnings)
2349 Driver Separate Var(wrapper_string)
2352 Driver Joined Separate
2355 Common RejectNegative Negative(pie)
2356 Create a shared library
2362 Driver Separate Alias(specs=)
2375 ; Documented for Fortran, but always accepted by driver.
2382 ; Documented for Go, but always accepted by driver.
2388 Common RejectNegative Negative(shared)
2389 Create a position independent executable
2392 Driver Joined Separate
2394 ; This comment is to ensure we retain the blank line above.