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 ; 0 means straightforward implementation of complex divide acceptable.
41 ; 1 means wide ranges of inputs must work for complex divide.
42 ; 2 means C99-like requirements for complex multiply and divide.
44 int flag_complex_method = 1
46 ; Nonzero if subexpressions must be evaluated from left-to-right.
48 int flag_evaluation_order = 0
50 ; Language specific warning pass for unused results.
52 bool flag_warn_unused_result = false
57 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
61 ; True to warn about any objects definitions whose size is larger
62 ; than N bytes. Also want about function definitions whose returned
63 ; values are larger than N bytes, where N is 'larger_than_size'.
68 HOST_WIDE_INT larger_than_size
70 ; True to warn about any function whose frame size is larger
73 bool warn_frame_larger_than
76 HOST_WIDE_INT frame_larger_than_size
78 ; Nonzero means we should be saving declaration info into a .X file.
80 int flag_gen_aux_info = 0
82 ; Nonzero if we are compiling code for a shared library, zero for
87 ; These two are really VEC(char_p,heap) *.
90 void *flag_instrument_functions_exclude_functions
93 void *flag_instrument_functions_exclude_files
95 ; Generic structs (e.g. templates not explicitly specialized)
96 ; may not have a compilation unit associated with them, and so
97 ; may need to be treated differently from ordinary structs.
99 ; Structs only handled by reference (indirectly), will also usually
100 ; not need as much debugging information.
103 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
106 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
108 ; True if we should exit after parsing options.
110 bool exit_after_options
112 ; Type(s) of debugging information we are producing (if any). See
113 ; flag-types.h for the definitions of the different possible types of
114 ; debugging information.
116 enum debug_info_type write_symbols = NO_DEBUG
118 ; Level of debugging information we are producing. See flag-types.h
119 ; for the definitions of the different possible levels.
121 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
123 ; Nonzero means use GNU-only extensions in the generated symbolic
124 ; debugging information. Currently, this only has an effect when
125 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
127 bool use_gnu_debug_info_extensions
129 ; Original value of maximum field alignment in bytes, specified via
130 ; -fpack-struct=<value>.
132 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
135 enum vect_verbosity_levels user_vect_verbosity_level = MAX_VERBOSITY_LEVEL
137 ; Type of stack check.
139 enum stack_check_type flag_stack_check = NO_STACK_CHECK
141 ; -dA causes debug commentary information to be produced in
142 ; the generated assembly code (to make it more readable). This option
143 ; is generally only of use to those who actually need to read the
144 ; generated assembly code (perhaps while debugging the compiler itself).
145 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
146 ; to be a catchall for printing debug information in the assembler file.
150 ; -dP causes the rtl to be emitted as a comment in assembly.
152 int flag_dump_rtl_in_asm
154 ; Whether -da was passed (used only in handle_common_deferred_options).
156 bool flag_dump_all_passed
158 ; Other flags saying which kinds of debugging dump have been requested.
161 int rtl_dump_and_exit
164 int flag_print_asm_name
167 enum graph_dump_types graph_dump_format = no_graph
169 ; Name of top-level original source file (what was input to cpp).
170 ; This comes from the #-command at the beginning of the actual input.
171 ; If there isn't any there, then this is the cc1 input file name.
173 const char *main_input_filename
175 ; Pointer to base name in main_input_filename, with directories and a
176 ; single final extension removed, and the length of this base
180 const char *main_input_basename
183 int main_input_baselength
185 ; Which options have been printed by --help.
189 ; Which enums have been printed by --help. 0 = not printed, no
190 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
193 char *help_enum_printed
195 ; The number of columns for --help output.
197 unsigned int help_columns
199 ; Whether this options structure has been through finish_options
201 bool flag_opts_finished
213 Driver Alias(coverage)
219 Common Separate Alias(d)
222 Common Joined Alias(d)
225 Common Separate Alias(dumpbase)
228 Common Separate Alias(dumpdir)
231 Driver Separate Alias(e)
234 Driver Joined Alias(e)
237 Common Warning Alias(Wextra)
240 Driver Separate Alias(Xassembler)
243 Driver JoinedOrMissing Alias(Xassembler)
246 Driver Separate Alias(Xlinker)
249 Driver JoinedOrMissing Alias(Xlinker)
252 Driver Separate Alias(u)
255 Driver Joined Alias(u)
258 Common Driver Var(help_flag)
259 Display this information
262 Common Driver Report Joined
263 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
266 Driver Separate Alias(x)
269 Driver Joined Alias(x)
272 Driver Separate Alias(L)
275 Driver Joined Alias(L)
277 -no-canonical-prefixes
278 Driver Alias(no-canonical-prefixes)
280 -no-standard-libraries
281 Driver Alias(nostdlib)
290 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
293 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
296 Driver Alias(pass-exit-codes)
299 Common Alias(pedantic)
302 Common Alias(pedantic-errors)
311 Driver Separate Alias(B)
314 Driver JoinedOrMissing Alias(B)
320 Driver Separate Alias(print-file-name=)
323 Driver JoinedOrMissing Alias(print-file-name=)
325 -print-libgcc-file-name
326 Driver Alias(print-libgcc-file-name)
328 -print-multi-directory
329 Driver Alias(print-multi-directory)
332 Driver Alias(print-multi-lib)
334 -print-multi-os-directory
335 Driver Alias(print-multi-os-directory)
338 Driver Separate Alias(print-prog-name=)
341 Driver JoinedOrMissing Alias(print-prog-name=)
344 Driver Alias(print-search-dirs)
347 Driver Alias(print-sysroot)
349 -print-sysroot-headers-suffix
350 Driver Alias(print-sysroot-headers-suffix)
356 Driver Alias(save-temps)
362 Driver Separate Alias(specs=)
365 Driver Joined Alias(specs=)
371 Driver Alias(symbolic)
375 Alias for --help=target
383 ;; The driver used to convert options such as --help into forms such
384 ;; as -fhelp; the following four entries are for compatibility with
385 ;; any direct uses of those (undocumented) -f forms
387 Common Driver Alias(-help)
390 Common Driver Joined Alias(-help=)
393 Common Driver Alias(-target-help)
396 Common Driver Alias(-version)
400 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
403 Common Joined Alias(-param)
406 Driver Separate Alias(-sysroot=)
409 Driver JoinedOrMissing
415 Driver Joined Separate
421 Driver Joined Separate
427 Common JoinedOrMissing Optimization
428 -O<number> Set optimization level to <number>
432 Optimize for space rather than speed
436 Optimize for speed disregarding exact standards compliance
448 Driver Joined Separate
454 Driver Joined Separate
475 Common RejectNegative Warning Alias(Wextra)
476 This switch is deprecated; use -Wextra instead
479 Driver JoinedOrMissing
482 Driver JoinedOrMissing
485 Driver JoinedOrMissing
488 Common Var(warn_aggregate_return) Warning
489 Warn about returning structures, unions or arrays
492 Common Var(warn_array_bounds) Warning
493 Warn if an array is accessed out of bounds
496 Common Var(warn_attributes) Init(1) Warning
497 Warn about inappropriate attribute usage
500 Common Var(warn_cast_align) Warning
501 Warn about pointer casts which increase alignment
504 Common Var(warn_cpp) Init(1) Warning
505 Warn when a #warning directive is encountered
507 Wdeprecated-declarations
508 Common Var(warn_deprecated_decl) Init(1) Warning
509 Warn about uses of __attribute__((deprecated)) declarations
511 Wdisabled-optimization
512 Common Var(warn_disabled_optimization) Warning
513 Warn when an optimization pass is disabled
516 Common Var(warnings_are_errors)
517 Treat all warnings as errors
521 Treat specified warning as error
524 Common Var(extra_warnings) Warning
525 Print extra (possibly unwanted) warnings
528 Common Var(flag_fatal_errors)
529 Exit on the first error occurred
532 Common RejectNegative Joined UInteger
533 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
536 Common Var(warn_inline) Warning
537 Warn when an inlined function cannot be inlined
540 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
543 Common RejectNegative Joined UInteger Warning
544 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
546 Wunsafe-loop-optimizations
547 Common Var(warn_unsafe_loop_optimizations) Warning
548 Warn if the loop cannot be optimized due to nontrivial assumptions.
551 Common Var(warn_missing_noreturn) Warning
552 Warn about functions which might be candidates for __attribute__((noreturn))
555 Common Var(warn_mudflap) Init(1) Warning
556 Warn about constructs not instrumented by -fmudflap
559 Common Var(warn_overflow) Init(1) Warning
560 Warn about overflow in arithmetic expressions
563 Common Var(warn_packed) Warning
564 Warn when the packed attribute has no effect on struct layout
567 Common Var(warn_padded) Warning
568 Warn when padding is required to align structure members
571 Common Var(warn_shadow) Warning
572 Warn when one local variable shadows another
575 Common Var(warn_stack_protect) Warning
576 Warn when not issuing stack smashing protection for some reason
580 Warn about code which might break strict aliasing rules
583 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Init(-1) Warning
584 Warn about code which might break strict aliasing rules
588 Warn about optimizations that assume that signed overflow is undefined
591 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Init(-1) Warning
592 Warn about optimizations that assume that signed overflow is undefined
594 Wsuggest-attribute=const
595 Common Var(warn_suggest_attribute_const) Warning
596 Warn about functions which might be candidates for __attribute__((const))
598 Wsuggest-attribute=pure
599 Common Var(warn_suggest_attribute_pure) Warning
600 Warn about functions which might be candidates for __attribute__((pure))
602 Wsuggest-attribute=noreturn
603 Common Var(warn_suggest_attribute_noreturn) Warning
604 Warn about functions which might be candidates for __attribute__((noreturn))
607 Common Var(warn_switch) Warning
608 Warn about enumerated switches, with no default, missing a case
611 Common Var(warn_switch_default) Warning
612 Warn about enumerated switches missing a \"default:\" statement
615 Common Var(warn_switch_enum) Warning
616 Warn about all enumerated switches missing a specific case
619 Common Var(warn_system_headers) Warning
620 Do not suppress warnings from system headers
623 Common Var(warn_trampolines) Warning
624 Warn whenever a trampoline is generated
627 Common Var(warn_type_limits) Init(-1) Warning
628 Warn if a comparison is always true or always false due to the limited range of the data type
631 Common Var(warn_uninitialized) Init(-1) Warning
632 Warn about uninitialized automatic variables
636 Does nothing. Preserved for backward compatibility.
639 Common Var(warn_unused) Init(0) Warning
640 Enable all -Wunused- warnings
642 Wunused-but-set-parameter
643 Common Var(warn_unused_but_set_parameter) Init(-1) Warning
644 Warn when a function parameter is only set, otherwise unused
646 Wunused-but-set-variable
647 Common Var(warn_unused_but_set_variable) Init(-1) Warning
648 Warn when a variable is only set, otherwise unused
651 Common Var(warn_unused_function) Init(-1) Warning
652 Warn when a function is unused
655 Common Var(warn_unused_label) Init(-1) Warning
656 Warn when a label is unused
659 Common Var(warn_unused_parameter) Init(-1) Warning
660 Warn when a function parameter is unused
663 Common Var(warn_unused_value) Init(-1) Warning
664 Warn when an expression value is unused
667 Common Var(warn_unused_variable) Init(-1) Warning
668 Warn when a variable is unused
671 Common Var(warn_coverage_mismatch) Init(1) Warning
672 Warn in case profiles in -fprofile-use do not match
687 Common Separate Var(aux_info_file_name)
688 -aux-info <file> Emit declaration information into <file>
691 Common Joined Alias(aux-info)
694 Common Separate RejectDriver Var(aux_base_name)
697 Common Separate RejectDriver
707 -d<letters> Enable dumps from specific passes of the compiler
710 Common Separate Var(dump_base_name)
711 -dumpbase <file> Set the file basename to be used for dumps
714 Common Separate Var(dump_dir_name)
715 -dumpdir <dir> Set the directory name to be used for dumps
727 Driver Joined Separate
729 ; This option has historically been passed down to the linker by an
730 ; accident of a %{e*} spec, so ensure it continues to be passed down
731 ; as a single option. The supported option for this purpose is
732 ; -rdynamic. See PR 47390.
736 ; The version of the C++ ABI in use. The following values are allowed:
738 ; 0: The version of the ABI believed most conformant with the C++ ABI
739 ; specification. This ABI may change as bugs are discovered and fixed.
740 ; Therefore, 0 will not necessarily indicate the same ABI in different
743 ; 1: The version of the ABI first used in G++ 3.2.
745 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
747 ; 3: The version of the ABI that fixes the missing underscore
748 ; in template non-type arguments of pointer type.
750 ; 4: The version of the ABI that introduces unambiguous mangling of
751 ; vector types. First selectable in G++ 4.5.
753 ; 5: The version of the ABI that ignores attribute const/noreturn
754 ; in function pointer mangling, and corrects mangling of decltype and
755 ; function parameters used in other parameters and the return type.
756 ; First selectable in G++ 4.6.
758 ; Additional positive integers will be assigned as new versions of
759 ; the ABI become the default version of the ABI.
761 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
764 Common Report Var(align_functions,0) Optimization UInteger
765 Align the start of functions
768 Common RejectNegative Joined UInteger Var(align_functions)
771 Common Report Var(align_jumps,0) Optimization UInteger
772 Align labels which are only reached by jumping
775 Common RejectNegative Joined UInteger Var(align_jumps)
778 Common Report Var(align_labels,0) Optimization UInteger
782 Common RejectNegative Joined UInteger Var(align_labels)
785 Common Report Var(align_loops,0) Optimization UInteger
786 Align the start of loops
789 Common RejectNegative Joined UInteger Var(align_loops)
793 Does nothing. Preserved for backward compatibility.
797 Does nothing. Preserved for backward compatibility.
799 fargument-noalias-global
801 Does nothing. Preserved for backward compatibility.
803 fargument-noalias-anything
805 Does nothing. Preserved for backward compatibility.
807 fasynchronous-unwind-tables
808 Common Report Var(flag_asynchronous_unwind_tables) Optimization
809 Generate unwind tables that are exact at each instruction boundary
812 Common Report Var(flag_auto_inc_dec) Init(1)
813 Generate auto-inc/dec instructions
815 ; -fcheck-bounds causes gcc to generate array bounds checks.
816 ; For C, C++ and ObjC: defaults off.
817 ; For Java: defaults to on.
818 ; For Fortran: defaults to off.
820 Common Report Var(flag_bounds_check)
821 Generate code to check bounds before indexing arrays
824 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
825 Replace add, compare, branch with branch on count register
827 fbranch-probabilities
828 Common Report Var(flag_branch_probabilities) Optimization
829 Use profiling information for branch probabilities
831 fbranch-target-load-optimize
832 Common Report Var(flag_branch_target_load_optimize) Optimization
833 Perform branch target load optimization before prologue / epilogue threading
835 fbranch-target-load-optimize2
836 Common Report Var(flag_branch_target_load_optimize2) Optimization
837 Perform branch target load optimization after prologue / epilogue threading
840 Common Report Var(flag_btr_bb_exclusive) Optimization
841 Restrict target load migration not to re-use registers in any basic block
844 Common Joined RejectNegative Var(common_deferred_options) Defer
845 -fcall-saved-<register> Mark <register> as being preserved across functions
848 Common Joined RejectNegative Var(common_deferred_options) Defer
849 -fcall-used-<register> Mark <register> as being corrupted by function calls
851 ; Nonzero for -fcaller-saves: allocate values in regs that need to
852 ; be saved across function calls, if that produces overall better code.
853 ; Optional now, so people can test it.
855 Common Report Var(flag_caller_saves) Optimization
856 Save registers around function calls
859 Common Report Var(flag_check_data_deps)
860 Compare the results of several data dependence analyzers.
862 fcombine-stack-adjustments
863 Common Report Var(flag_combine_stack_adjustments) Optimization
864 Looks for opportunities to reduce stack adjustments and stack references.
867 Common Report Var(flag_no_common,0) Optimization
868 Do not put uninitialized globals in the common section
872 ; Converted by the driver to -fcompare-debug= options.
875 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
876 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
878 fcompare-debug-second
879 Common Driver RejectNegative Var(flag_compare_debug)
880 Run only the second compilation of -fcompare-debug
883 Common Report Var(flag_compare_elim_after_reload) Optimization
884 Perform comparison elimination after register allocation has finished
887 Common Var(flag_conserve_stack) Optimization
888 Do not perform optimizations increasing noticeably stack usage
891 Common Report Var(flag_cprop_registers) Optimization
892 Perform a register copy-propagation optimization pass
895 Common Report Var(flag_crossjumping) Optimization
896 Perform cross-jumping optimization
899 Common Report Var(flag_cse_follow_jumps) Optimization
900 When running CSE, follow jumps to their targets
904 Does nothing. Preserved for backward compatibility.
907 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
908 Omit range reduction step when performing complex division
911 Common Report Var(flag_cx_fortran_rules) Optimization
912 Complex multiplication and division follow Fortran rules
915 Common Report Var(flag_data_sections) Optimization
916 Place data items into their own section
919 Common Report Var(common_deferred_options) Defer
920 List all available debugging counters with their limits and counts.
923 Common RejectNegative Joined Var(common_deferred_options) Defer
924 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
927 Common Joined RejectNegative Var(common_deferred_options) Defer
928 Map one directory name to another in debug information
931 Common Report Var(flag_debug_types_section) Init(1)
932 Output .debug_types section when using DWARF v4 debuginfo.
934 ; Nonzero for -fdefer-pop: don't pop args after each function call
935 ; instead save them up to pop many calls' args with one insns.
937 Common Report Var(flag_defer_pop) Optimization
938 Defer popping functions args from stack until later
941 Common Report Var(flag_delayed_branch) Optimization
942 Attempt to fill delay slots of branch instructions
944 fdelete-null-pointer-checks
945 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
946 Delete useless null pointer checks
949 Common Report Var(flag_devirtualize) Optimization
950 Try to convert virtual calls to direct ones.
952 fdiagnostics-show-location=
953 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
954 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
956 ; Required for these enum values.
961 Name(diagnostic_prefixing_rule) Type(int)
964 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
967 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
969 fdiagnostics-show-option
970 Common Var(flag_diagnostics_show_option) Init(1)
971 Amend appropriate diagnostic messages with the command line option that controls them
974 Common Joined RejectNegative Var(common_deferred_options) Defer
975 -fdump-<type> Dump various compiler internals to a file
978 Driver RejectNegative
981 Common RejectNegative Joined Var(flag_dump_final_insns)
982 -fdump-final-insns=filename Dump to filename the insns at the end of translation
985 Common RejectNegative Joined Var(flag_dump_go_spec)
986 -fdump-go-spec=filename Write all declarations to file as Go code
989 Common Report Var(flag_dump_noaddr)
990 Suppress output of addresses in debugging dumps
993 Common Report Var(flag_dump_unnumbered)
994 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
996 fdump-unnumbered-links
997 Common Report Var(flag_dump_unnumbered_links)
998 Suppress output of previous and next insn numbers in debugging dumps
1001 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1002 Enable CFI tables via GAS assembler directives.
1005 Common Report Var(flag_early_inlining) Init(1) Optimization
1006 Perform early inlining
1008 feliminate-dwarf2-dups
1009 Common Report Var(flag_eliminate_dwarf2_dups)
1010 Perform DWARF2 duplicate elimination
1013 Common Report Var(flag_ipa_sra) Init(0) Optimization
1014 Perform interprocedural reduction of aggregates
1016 feliminate-unused-debug-symbols
1017 Common Report Var(flag_debug_only_used_symbols)
1018 Perform unused type elimination in debug info
1020 feliminate-unused-debug-types
1021 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1022 Perform unused type elimination in debug info
1024 femit-class-debug-always
1025 Common Report Var(flag_emit_class_debug_always) Init(0)
1026 Do not suppress C++ class debug information.
1029 Common Report Var(flag_exceptions) Optimization
1030 Enable exception handling
1032 fexpensive-optimizations
1033 Common Report Var(flag_expensive_optimizations) Optimization
1034 Perform a number of minor, expensive optimizations
1037 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1038 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1041 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1044 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1047 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1053 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1054 Assume no NaNs or infinities are generated
1057 Common Joined RejectNegative Var(common_deferred_options) Defer
1058 -ffixed-<register> Mark <register> as being unavailable to the compiler
1061 Common Report Var(flag_float_store) Optimization
1062 Don't allocate floats and doubles in extended-precision registers
1066 Does nothing. Preserved for backward compatibility.
1069 Common Report Var(flag_forward_propagate) Optimization
1070 Perform a forward propagation pass on RTL
1073 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1074 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1077 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1080 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1082 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1084 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1087 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1089 ; Nonzero means don't put addresses of constant functions in registers.
1090 ; Used for compiling the Unix kernel, where strange substitutions are
1091 ; done on the assembly output.
1093 Common Report Var(flag_no_function_cse,0)
1094 Allow function addresses to be held in registers
1097 Common Report Var(flag_function_sections)
1098 Place each function into its own section
1101 Common Report Var(flag_gcse) Optimization
1102 Perform global common subexpression elimination
1105 Common Report Var(flag_gcse_lm) Init(1) Optimization
1106 Perform enhanced load motion during global common subexpression elimination
1109 Common Report Var(flag_gcse_sm) Init(0) Optimization
1110 Perform store motion after global common subexpression elimination
1113 Common Report Var(flag_gcse_las) Init(0) Optimization
1114 Perform redundant load after store elimination in global common subexpression
1118 Common Report Var(flag_gcse_after_reload) Optimization
1119 Perform global common subexpression elimination after register allocation
1122 ; This option is not documented yet as its semantics will change.
1124 Common Report Var(flag_graphite)
1125 Enable in and out of Graphite representation
1128 Common Report Var(flag_graphite_identity) Optimization
1129 Enable Graphite Identity transformation
1131 floop-parallelize-all
1132 Common Report Var(flag_loop_parallelize_all) Optimization
1133 Mark all loops as parallel
1136 Common Report Var(flag_loop_strip_mine) Optimization
1137 Enable Loop Strip Mining transformation
1140 Common Report Var(flag_loop_interchange) Optimization
1141 Enable Loop Interchange transformation
1144 Common Report Var(flag_loop_block) Optimization
1145 Enable Loop Blocking transformation
1148 Common Report Var(flag_loop_flatten) Optimization
1149 Enable Loop Flattening transformation
1151 fstrict-volatile-bitfields
1152 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1153 Force bitfield accesses to match their type width
1155 fguess-branch-probability
1156 Common Report Var(flag_guess_branch_prob) Optimization
1157 Enable guessing of branch probabilities
1159 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1160 ; Generate position-independent code for executables if possible
1161 ; On SVR4 targets, it also controls whether or not to emit a
1162 ; string identifying the compiler.
1164 Common Report Var(flag_no_ident,0)
1165 Process #ident directives
1168 Common Report Var(flag_if_conversion) Optimization
1169 Perform conversion of conditional jumps to branchless equivalents
1172 Common Report Var(flag_if_conversion2) Optimization
1173 Perform conversion of conditional jumps to conditional execution
1175 ftree-loop-if-convert
1176 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1177 Convert conditional jumps in innermost loops to branchless equivalents
1179 ftree-loop-if-convert-stores
1180 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1181 Also if-convert conditional jumps containing memory writes
1183 ; -finhibit-size-directive inhibits output of .size for ELF.
1184 ; This is used only for compiling crtstuff.c,
1185 ; and it may be extended to other effects
1186 ; needed for crtstuff.c on other systems.
1187 finhibit-size-directive
1188 Common Report Var(flag_inhibit_size_directive)
1189 Do not generate .size directives
1192 Common Report Var(flag_indirect_inlining)
1193 Perform indirect inlining
1195 ; Nonzero means that functions declared `inline' will be treated
1196 ; as `static'. Prevents generation of zillions of copies of unused
1197 ; static inline functions; instead, `inlines' are written out
1198 ; only when actually used. Used in conjunction with -g. Also
1199 ; does the right thing with #pragma interface.
1201 Common Report Var(flag_no_inline,0) Init(0)
1202 Pay attention to the \"inline\" keyword
1204 finline-small-functions
1205 Common Report Var(flag_inline_small_functions) Optimization
1206 Integrate simple functions into their callers when code size is known to not growth
1209 Common Report Var(flag_inline_functions) Optimization
1210 Integrate simple functions into their callers
1212 finline-functions-called-once
1213 Common Report Var(flag_inline_functions_called_once) Init(1) Optimization
1214 Integrate functions called once into their callers
1217 Common RejectNegative Joined Alias(finline-limit=)
1220 Common RejectNegative Joined UInteger
1221 -finline-limit=<number> Limit the size of inlined functions to <number>
1223 finstrument-functions
1224 Common Report Var(flag_instrument_function_entry_exit)
1225 Instrument function entry and exit with profiling calls
1227 finstrument-functions-exclude-function-list=
1228 Common RejectNegative Joined
1229 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1231 finstrument-functions-exclude-file-list=
1232 Common RejectNegative Joined
1233 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1236 Common Report Var(flag_ipa_cp) Optimization
1237 Perform Interprocedural constant propagation
1240 Common Report Var(flag_ipa_cp_clone) Optimization
1241 Perform cloning to make Interprocedural constant propagation stronger
1244 Common Report Var(flag_ipa_profile) Init(0) Optimization
1245 Perform interprocedural profile propagation
1248 Common Report Var(flag_ipa_pta) Init(0) Optimization
1249 Perform interprocedural points-to analysis
1252 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1253 Discover pure and const functions
1256 Common Report Var(flag_ipa_reference) Init(0) Optimization
1257 Discover readonly and non addressable static variables
1260 Common Report Var(flag_ipa_matrix_reorg) Optimization
1261 Perform matrix layout flattening and transposing based
1262 on profiling information.
1266 Does nothing. Preserved for backward compatibility.
1269 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1270 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1273 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1276 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1279 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1282 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_MIXED)
1283 -fira-region=[one|all|mixed] Set regions for IRA
1286 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1289 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1292 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1295 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1298 Common Report Var(flag_ira_loop_pressure)
1299 Use IRA based register pressure calculation
1300 in RTL loop optimizations.
1302 fira-share-save-slots
1303 Common Report Var(flag_ira_share_save_slots) Init(1)
1304 Share slots for saving different hard registers.
1306 fira-share-spill-slots
1307 Common Report Var(flag_ira_share_spill_slots) Init(1)
1308 Share stack slots for spilled pseudo-registers.
1311 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1312 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1315 Common Report Var(flag_ivopts) Init(1) Optimization
1316 Optimize induction variables on trees
1319 Common Var(flag_jump_tables) Init(1) Optimization
1320 Use jump tables for sufficiently large switch statements
1322 fkeep-inline-functions
1323 Common Report Var(flag_keep_inline_functions)
1324 Generate code for functions even if they are fully inlined
1327 Common Report Var(flag_keep_static_consts) Init(1)
1328 Emit static const variables even if they are not used
1331 Common Report Var(flag_leading_underscore) Init(-1)
1332 Give external symbols a leading underscore
1336 Does nothing. Preserved for backward compatibility.
1340 Enable link-time optimization.
1343 Common RejectNegative Joined Var(flag_lto)
1344 Link-time optimization with number of parallel jobs or jobserver.
1347 Common Var(flag_lto_partition_1to1)
1348 Partition functions and vars at linktime based on object files they originate from
1350 flto-partition=balanced
1351 Common Var(flag_lto_partition_balanced)
1352 Partition functions and vars at linktime into approximately same sized buckets
1355 Common Var(flag_lto_partition_none)
1356 Disable partioning and streaming
1358 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1359 flto-compression-level=
1360 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1361 -flto-compression-level=<number> Use zlib compression level <number> for IL
1364 Common Report Var(flag_lto_report) Init(0) Optimization
1365 Report various link-time optimization statistics
1368 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1369 Set errno after built-in math functions
1372 Common Joined RejectNegative UInteger Var(flag_max_errors)
1373 -fmax-errors=<number> Maximum number of errors to report
1376 Common Report Var(mem_report)
1377 Report on permanent memory allocation
1379 ; This will attempt to merge constant section constants, if 1 only
1380 ; string constants and constants from constant pool, if 2 also constant
1382 fmerge-all-constants
1383 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1384 Attempt to merge identical constants and constant variables
1387 Common Report Var(flag_merge_constants,1) Optimization
1388 Attempt to merge identical constants across compilation units
1390 fmerge-debug-strings
1391 Common Report Var(flag_merge_debug_strings) Init(1)
1392 Attempt to merge identical debug strings across compilation units
1395 Common RejectNegative Joined UInteger
1396 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1399 Common Report Var(flag_modulo_sched) Optimization
1400 Perform SMS based modulo scheduling before the first scheduling pass
1402 fmodulo-sched-allow-regmoves
1403 Common Report Var(flag_modulo_sched_allow_regmoves)
1404 Perform SMS based modulo scheduling with register moves allowed
1406 fmove-loop-invariants
1407 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1408 Move loop invariant computations out of loops
1411 Common RejectNegative Report Var(flag_mudflap)
1412 Add mudflap bounds-checking instrumentation for single-threaded program
1415 Common RejectNegative Report Var(flag_mudflap,2)
1416 Add mudflap bounds-checking instrumentation for multi-threaded program
1419 Common RejectNegative Report Var(flag_mudflap_ignore_reads)
1420 Ignore read operations when inserting mudflap instrumentation
1423 Common Var(flag_dce) Init(1) Optimization
1424 Use the RTL dead code elimination pass
1427 Common Var(flag_dse) Init(1) Optimization
1428 Use the RTL dead store elimination pass
1430 freschedule-modulo-scheduled-loops
1431 Common Report Var(flag_resched_modulo_sched) Optimization
1432 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1434 fnon-call-exceptions
1435 Common Report Var(flag_non_call_exceptions) Optimization
1436 Support synchronous non-call exceptions
1439 Common Report Var(flag_omit_frame_pointer) Optimization
1440 When possible do not generate stack frames
1442 foptimize-register-move
1443 Common Report Var(flag_regmove) Optimization
1444 Do the full register move optimization pass
1446 foptimize-sibling-calls
1447 Common Report Var(flag_optimize_sibling_calls) Optimization
1448 Optimize sibling and tail recursive calls
1451 Common Report Var(flag_partial_inlining)
1452 Perform partial inlining
1455 Common Report Var(pre_ipa_mem_report)
1456 Report on memory allocation before interprocedural optimization
1458 fpost-ipa-mem-report
1459 Common Report Var(post_ipa_mem_report)
1460 Report on memory allocation before interprocedural optimization
1463 Common Report Var(flag_pack_struct) Optimization
1464 Pack structure members together without holes
1467 Common RejectNegative Joined UInteger Optimization
1468 -fpack-struct=<number> Set initial maximum structure member alignment
1471 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1472 Return small aggregates in memory, not registers
1475 Common Report Var(flag_peel_loops) Optimization
1476 Perform loop peeling
1479 Common Report Var(flag_no_peephole,0) Optimization
1480 Enable machine specific peephole optimizations
1483 Common Report Var(flag_peephole2) Optimization
1484 Enable an RTL peephole pass before sched2
1487 Common Report Var(flag_pic,2)
1488 Generate position-independent code if possible (large mode)
1491 Common Report Var(flag_pie,2)
1492 Generate position-independent code for executables if possible (large mode)
1495 Common Report Var(flag_pic,1)
1496 Generate position-independent code if possible (small mode)
1499 Common Report Var(flag_pie,1)
1500 Generate position-independent code for executables if possible (small mode)
1503 Common Joined RejectNegative Var(common_deferred_options) Defer
1504 Specify a plugin to load
1507 Common Joined RejectNegative Var(common_deferred_options) Defer
1508 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1510 fpredictive-commoning
1511 Common Report Var(flag_predictive_commoning) Optimization
1512 Run predictive commoning optimization.
1514 fprefetch-loop-arrays
1515 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1516 Generate prefetch instructions, if available, for arrays in loops
1519 Common Report Var(profile_flag)
1520 Enable basic program profiling code
1523 Common Report Var(profile_arc_flag)
1524 Insert arc-based program profiling code
1527 Common Joined RejectNegative Var(profile_data_prefix)
1528 Set the top-level directory for storing the profile data.
1529 The default is 'pwd'.
1532 Common Report Var(flag_profile_correction)
1533 Enable correction of flow inconsistent profile data input
1537 Enable common options for generating profile info for profile feedback directed optimizations
1540 Common Joined RejectNegative
1541 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1544 Common Var(flag_profile_use)
1545 Enable common options for performing profile feedback directed optimizations
1548 Common Joined RejectNegative
1549 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1552 Common Report Var(flag_profile_values)
1553 Insert code to profile values of expressions
1556 Common Var(common_deferred_options) Defer
1559 Common Joined RejectNegative Var(common_deferred_options) Defer
1560 -frandom-seed=<string> Make compile reproducible using <string>
1562 ; This switch causes the command line that was used to create an
1563 ; object file to be recorded into the object file. The exact format
1564 ; of this recording is target and binary file format dependent.
1565 ; It is related to the -fverbose-asm switch, but that switch only
1566 ; records information in the assembler output file as comments, so
1567 ; they never reach the object file.
1568 frecord-gcc-switches
1569 Common Report Var(flag_record_gcc_switches)
1570 Record gcc command line switches in the object file.
1573 Common Report Var(flag_pcc_struct_return,0) Optimization
1574 Return small aggregates in registers
1577 Common Report Var(flag_regmove) Optimization
1578 Enables a register move optimization
1581 Common Report Var(flag_rename_registers) Init(2) Optimization
1582 Perform a register renaming optimization pass
1585 Common Report Var(flag_reorder_blocks) Optimization
1586 Reorder basic blocks to improve code placement
1588 freorder-blocks-and-partition
1589 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1590 Reorder basic blocks and partition into hot and cold sections
1593 Common Report Var(flag_reorder_functions) Optimization
1594 Reorder functions to improve code placement
1596 frerun-cse-after-loop
1597 Common Report Var(flag_rerun_cse_after_loop) Optimization
1598 Add a common subexpression elimination pass after loop optimizations
1602 Does nothing. Preserved for backward compatibility.
1605 Common Report Var(flag_rounding_math) Optimization SetByCombined
1606 Disable optimizations that assume default FP rounding behavior
1609 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1610 Enable scheduling across basic blocks
1613 Common Report Var(flag_sched_pressure) Init(0) Optimization
1614 Enable register pressure sensitive insn scheduling
1617 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1618 Allow speculative motion of non-loads
1621 Common Report Var(flag_schedule_speculative_load) Optimization
1622 Allow speculative motion of some loads
1624 fsched-spec-load-dangerous
1625 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1626 Allow speculative motion of more loads
1629 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1630 -fsched-verbose=<number> Set the verbosity level of the scheduler
1632 fsched2-use-superblocks
1633 Common Report Var(flag_sched2_use_superblocks) Optimization
1634 If scheduling post reload, do superblock scheduling
1638 Does nothing. Preserved for backward compatibility.
1641 Common Report Var(flag_schedule_insns) Optimization
1642 Reschedule instructions before register allocation
1645 Common Report Var(flag_schedule_insns_after_reload) Optimization
1646 Reschedule instructions after register allocation
1648 ; This flag should be on when a target implements non-trivial
1649 ; scheduling hooks, maybe saving some information for its own sake.
1650 ; On IA64, for example, this is used for correct bundling.
1651 fselective-scheduling
1652 Common Report Var(flag_selective_scheduling) Optimization
1653 Schedule instructions using selective scheduling algorithm
1655 fselective-scheduling2
1656 Common Report Var(flag_selective_scheduling2) Optimization
1657 Run selective scheduling after reload
1659 fsel-sched-pipelining
1660 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1661 Perform software pipelining of inner loops during selective scheduling
1663 fsel-sched-pipelining-outer-loops
1664 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1665 Perform software pipelining of outer loops during selective scheduling
1667 fsel-sched-reschedule-pipelined
1668 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1669 Reschedule pipelined regions without pipelining
1671 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1672 ; of stalled insns into the ready list.
1673 fsched-stalled-insns
1674 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1675 Allow premature scheduling of queued insns
1677 fsched-stalled-insns=
1678 Common RejectNegative Joined UInteger
1679 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1681 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1682 ; be examined for a dependency on a stalled insn that is candidate for
1683 ; premature removal from the queue of stalled insns into the ready list (has
1684 ; an effect only if the flag 'sched_stalled_insns' is set).
1685 fsched-stalled-insns-dep
1686 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1687 Set dependence distance checking in premature scheduling of queued insns
1689 fsched-stalled-insns-dep=
1690 Common RejectNegative Joined UInteger
1691 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1693 fsched-group-heuristic
1694 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1695 Enable the group heuristic in the scheduler
1697 fsched-critical-path-heuristic
1698 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1699 Enable the critical path heuristic in the scheduler
1701 fsched-spec-insn-heuristic
1702 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1703 Enable the speculative instruction heuristic in the scheduler
1705 fsched-rank-heuristic
1706 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1707 Enable the rank heuristic in the scheduler
1709 fsched-last-insn-heuristic
1710 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1711 Enable the last instruction heuristic in the scheduler
1713 fsched-dep-count-heuristic
1714 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1715 Enable the dependent count heuristic in the scheduler
1718 Common Report Var(flag_section_anchors) Optimization
1719 Access data in the same section from shared anchor points
1723 Does nothing. Preserved for backward compatibility.
1726 Common Report Var(flag_zee) Init(0)
1727 Eliminate redundant zero extensions on targets that support implicit extensions.
1730 Common Report Var(flag_show_column) Init(1)
1731 Show column numbers in diagnostics, when available. Default on
1734 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1735 Disable optimizations observable by IEEE signaling NaNs
1738 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1739 Disable floating point optimizations that ignore the IEEE signedness of zero
1741 fsingle-precision-constant
1742 Common Report Var(flag_single_precision_constant) Optimization
1743 Convert floating point constants to single precision constants
1745 fsplit-ivs-in-unroller
1746 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1747 Split lifetimes of induction variables when loops are unrolled
1750 Common Report Var(flag_split_stack) Init(-1)
1751 Generate discontiguous stack frames
1754 Common Report Var(flag_split_wide_types) Optimization
1755 Split wide types into independent registers
1757 fvariable-expansion-in-unroller
1758 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1759 Apply variable expansion when loops are unrolled
1762 Common Report RejectNegative Joined
1763 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1766 Common Alias(fstack-check=, specific, no)
1767 Insert stack checking code into the program. Same as -fstack-check=specific
1770 Common Var(common_deferred_options) Defer
1772 fstack-limit-register=
1773 Common RejectNegative Joined Var(common_deferred_options) Defer
1774 -fstack-limit-register=<register> Trap if the stack goes past <register>
1776 fstack-limit-symbol=
1777 Common RejectNegative Joined Var(common_deferred_options) Defer
1778 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1781 Common Report Var(flag_stack_protect, 1)
1782 Use propolice as a stack protection method
1784 fstack-protector-all
1785 Common Report RejectNegative Var(flag_stack_protect, 2)
1786 Use a stack protection method for every function
1789 Common RejectNegative Var(flag_stack_usage)
1790 Output stack usage information on a per-function basis
1794 Does nothing. Preserved for backward compatibility.
1796 ; Nonzero if we should do (language-dependent) alias analysis.
1797 ; Typically, this analysis will assume that expressions of certain
1798 ; types do not alias expressions of certain other types. Only used
1799 ; if alias analysis (in general) is enabled.
1801 Common Report Var(flag_strict_aliasing) Optimization
1802 Assume strict aliasing rules apply
1805 Common Report Var(flag_strict_overflow)
1806 Treat signed overflow as undefined
1809 Common Report Var(flag_syntax_only)
1810 Check for syntax errors, then stop
1813 Common Report Var(flag_test_coverage)
1814 Create data files needed by \"gcov\"
1817 Common Report Var(flag_thread_jumps) Optimization
1818 Perform jump threading optimizations
1821 Common Report Var(time_report)
1822 Report the time taken by each compiler pass
1825 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1826 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1829 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1832 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1835 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1838 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1841 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1844 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1845 Reorder top level functions, variables, and asms
1848 Common Report Var(flag_tracer)
1849 Perform superblock formation via tail duplication
1851 ; Zero means that floating-point math operations cannot generate a
1852 ; (user-visible) trap. This is the case, for example, in nonstop
1853 ; IEEE 754 arithmetic.
1855 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1856 Assume floating-point operations can trap
1859 Common Report Var(flag_trapv) Optimization
1860 Trap for signed overflow in addition, subtraction and multiplication
1863 Common Report Var(flag_tree_ccp) Optimization
1864 Enable SSA-CCP optimization on trees
1867 Common Report Var(flag_tree_bit_ccp) Optimization
1868 Enable SSA-BIT-CCP optimization on trees
1872 Does nothing. Preserved for backward compatibility.
1875 Common Report Var(flag_tree_ch) Optimization
1876 Enable loop header copying on trees
1879 Common Report Var(flag_tree_copyrename) Optimization
1880 Replace SSA temporaries with better names in copies
1883 Common Report Var(flag_tree_copy_prop) Optimization
1884 Enable copy propagation on trees
1886 ftree-store-copy-prop
1888 Does nothing. Preserved for backward compatibility.
1891 Common Report Var(flag_tree_cselim) Init(2) Optimization
1892 Transform condition stores into unconditional ones
1894 ftree-switch-conversion
1895 Common Report Var(flag_tree_switch_conversion) Optimization
1896 Perform conversions of switch initializations.
1899 Common Report Var(flag_tree_dce) Optimization
1900 Enable SSA dead code elimination optimization on trees
1902 ftree-dominator-opts
1903 Common Report Var(flag_tree_dom) Optimization
1904 Enable dominator optimizations
1907 Common Report Var(flag_tree_dse) Optimization
1908 Enable dead store elimination
1911 Common Report Var(flag_tree_forwprop) Init(1) Optimization
1912 Enable forward propagation on trees
1915 Common Report Var(flag_tree_fre) Optimization
1916 Enable Full Redundancy Elimination (FRE) on trees
1918 ftree-loop-distribution
1919 Common Report Var(flag_tree_loop_distribution) Optimization
1920 Enable loop distribution on trees
1922 ftree-loop-distribute-patterns
1923 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
1924 Enable loop distribution for patterns transformed into a library call
1927 Common Report Var(flag_tree_loop_im) Init(1) Optimization
1928 Enable loop invariant motion on trees
1931 Common Alias(floop-interchange)
1932 Enable loop interchange transforms. Same as -floop-interchange
1935 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
1936 Create canonical induction variables in loops
1939 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
1940 Enable loop optimizations on tree level
1942 ftree-parallelize-loops=
1943 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
1944 Enable automatic parallelization of loops
1947 Common Report Var(flag_tree_phiprop) Init(1) Optimization
1948 Enable hoisting loads from conditional pointers.
1951 Common Report Var(flag_tree_pre) Optimization
1952 Enable SSA-PRE optimization on trees
1955 Common Report Var(flag_tree_pta) Init(1) Optimization
1956 Perform function-local points-to analysis on trees.
1959 Common Report Var(flag_tree_reassoc) Init(1) Optimization
1960 Enable reassociation on tree level
1964 Does nothing. Preserved for backward compatibility.
1967 Common Report Var(flag_tree_sink) Optimization
1968 Enable SSA code sinking on trees
1971 Common Report Var(flag_tree_sra) Optimization
1972 Perform scalar replacement of aggregates
1975 Common Report Var(flag_tree_ter) Optimization
1976 Replace temporary expressions in the SSA->normal pass
1979 Common Report Var(flag_tree_live_range_split) Optimization
1980 Perform live range splitting during the SSA->normal pass
1983 Common Report Var(flag_tree_vrp) Init(0) Optimization
1984 Perform Value Range Propagation on trees
1987 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
1988 Compile whole compilation unit at a time
1991 Common Report Var(flag_unroll_loops) Optimization
1992 Perform loop unrolling when iteration count is known
1995 Common Report Var(flag_unroll_all_loops) Optimization
1996 Perform loop unrolling for all loops
1998 ; Nonzero means that loop optimizer may assume that the induction variables
1999 ; that control loops do not overflow and that the loops with nontrivial
2000 ; exit condition are not infinite
2001 funsafe-loop-optimizations
2002 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2003 Allow loop optimizations to assume that the loops behave in normal way
2006 Common Report Var(flag_associative_math) SetByCombined
2007 Allow optimization for floating-point arithmetic which may change the
2008 result of the operation due to rounding.
2011 Common Report Var(flag_reciprocal_math) SetByCombined
2012 Same as -fassociative-math for expressions which include division.
2014 ; Nonzero means that unsafe floating-point math optimizations are allowed
2015 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2016 ; are allowed to assume that their arguments and results are "normal"
2017 ; (e.g., nonnegative for SQRT).
2018 funsafe-math-optimizations
2019 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2020 Allow math optimizations that may violate IEEE or ISO standards
2023 Common Report Var(flag_unswitch_loops) Optimization
2024 Perform loop unswitching
2027 Common Report Var(flag_unwind_tables) Optimization
2028 Just generate unwind tables for exception handling
2033 ; Positive if we should track variables, negative if we should run
2034 ; the var-tracking pass only to discard debug annotations, zero if
2035 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2036 ; will be set according to optimize, debug_info_level and debug_hooks
2037 ; in process_options ().
2039 Common Report Var(flag_var_tracking) Init(2) Optimization
2040 Perform variable tracking
2042 ; Positive if we should track variables at assignments, negative if
2043 ; we should run the var-tracking pass only to discard debug
2044 ; annotations. When flag_var_tracking_assignments ==
2045 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2046 fvar-tracking-assignments
2047 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2048 Perform variable tracking by annotating assignments
2050 ; Nonzero if we should toggle flag_var_tracking_assignments after
2051 ; processing options and computing its default. */
2052 fvar-tracking-assignments-toggle
2053 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2054 Toggle -fvar-tracking-assignments
2056 fvar-tracking-uninit
2057 Common Report Var(flag_var_tracking_uninit) Optimization
2058 Perform variable tracking and also tag variables that are uninitialized
2061 Common Report Var(flag_tree_vectorize) Optimization
2062 Enable loop vectorization on trees
2065 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2066 Enable basic block vectorization (SLP) on trees
2069 Common Report Var(flag_vect_cost_model) Optimization
2070 Enable use of cost model in vectorization
2072 ftree-vect-loop-version
2073 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2074 Enable loop versioning when doing loop vectorization on trees
2076 ftree-vectorizer-verbose=
2077 Common RejectNegative Joined UInteger
2078 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
2081 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2082 Enable copy propagation of scalar-evolution information.
2084 ; -fverbose-asm causes extra commentary information to be produced in
2085 ; the generated assembly code (to make it more readable). This option
2086 ; is generally only of use to those who actually need to read the
2087 ; generated assembly code (perhaps while debugging the compiler itself).
2088 ; -fno-verbose-asm, the default, causes the extra information
2089 ; to not be added and is useful when comparing two assembler files.
2091 Common Report Var(flag_verbose_asm)
2092 Add extra commentary to assembler output
2095 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2096 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2099 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2102 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2105 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2108 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2111 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2114 Common Report Var(flag_value_profile_transformations) Optimization
2115 Use expression value profiles in optimizations
2118 Common Report Var(flag_web) Init(2) Optimization
2119 Construct webs and split unrelated uses of single variable
2121 ftree-builtin-call-dce
2122 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2123 Enable conditional dead code elimination for builtin calls
2126 Common Report Var(flag_whole_program) Init(0) Optimization
2127 Perform whole program optimizations
2130 Common Report Var(flag_wrapv) Optimization
2131 Assume signed arithmetic overflow wraps around
2133 fzero-initialized-in-bss
2134 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2135 Put zero initialized data in the bss section
2138 Common JoinedOrMissing
2139 Generate debug information in default format
2142 Common JoinedOrMissing Negative(gdwarf-)
2143 Generate debug information in COFF format
2146 Common Joined UInteger Var(dwarf_version) Init(2) Negative(gstabs)
2147 Generate debug information in DWARF v2 (or later) format
2150 Common JoinedOrMissing
2151 Generate debug information in default extended format
2154 Common JoinedOrMissing Negative(gstabs+)
2155 Generate debug information in STABS format
2158 Common JoinedOrMissing Negative(gvms)
2159 Generate debug information in extended STABS format
2162 Common RejectNegative Var(dwarf_strict,0) Init(-1)
2163 Emit DWARF additions beyond selected version
2166 Common Report RejectNegative Var(dwarf_strict,1)
2167 Don't emit DWARF additions beyond selected version
2170 Common Report Var(flag_gtoggle)
2171 Toggle debug information generation
2174 Common JoinedOrMissing Negative(gxcoff)
2175 Generate debug information in VMS format
2178 Common JoinedOrMissing Negative(gxcoff+)
2179 Generate debug information in XCOFF format
2182 Common JoinedOrMissing Negative(gcoff)
2183 Generate debug information in extended XCOFF format
2186 Driver Joined Separate
2189 Common Joined Var(plugindir_string) Init(0)
2190 -iplugindir=<dir> Set <dir> to be the default plugin directory
2193 Driver Joined Separate
2198 no-canonical-prefixes
2211 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2212 -o <file> Place output into <file>
2215 Common Var(profile_flag)
2216 Enable function profiling
2219 Driver Var(pass_exit_codes)
2222 Common Var(pedantic)
2223 Issue warnings needed for strict compliance to the standard
2226 Common Var(flag_pedantic_errors)
2227 Like -pedantic but issue them as errors
2233 Driver Var(use_pipes)
2236 Driver JoinedOrMissing Var(print_file_name)
2238 print-libgcc-file-name
2241 print-multi-directory
2242 Driver Var(print_multi_directory)
2245 Driver Var(print_multi_lib)
2247 print-multi-os-directory
2248 Driver Var(print_multi_os_directory)
2251 Driver JoinedOrMissing Var(print_prog_name)
2254 Driver Var(print_search_dirs)
2257 Driver Var(print_sysroot)
2259 print-sysroot-headers-suffix
2260 Driver Var(print_sysroot_headers_suffix)
2263 Common Var(quiet_flag) RejectDriver
2264 Do not display functions compiled or elapsed time
2282 Driver Var(report_times)
2285 Driver JoinedOrMissing
2288 Driver Joined Separate
2292 ; C option, but driver must not handle as "-u ndef".
2295 Common Driver Var(verbose_flag)
2296 Enable verbose output
2299 Common Var(version_flag) RejectDriver
2300 Display the compiler's version
2303 Common Var(inhibit_warnings)
2307 Driver Separate Var(wrapper_string)
2310 Driver Joined Separate
2313 Common RejectNegative Negative(pie)
2314 Create a shared library
2320 Driver Separate Alias(specs=)
2333 ; Documented for Fortran, but always accepted by driver.
2340 ; Documented for Go, but always accepted by driver.
2346 Common RejectNegative Negative(shared)
2347 Create a position independent executable
2350 Driver Joined Separate
2352 ; This comment is to ensure we retain the blank line above.