1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 ; Free Software Foundation, Inc.
6 ; This file is part of GCC.
8 ; GCC is free software; you can redistribute it and/or modify it under
9 ; the terms of the GNU General Public License as published by the Free
10 ; Software Foundation; either version 3, or (at your option) any later
13 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 ; You should have received a copy of the GNU General Public License
19 ; along with GCC; see the file COPYING3. If not see
20 ; <http://www.gnu.org/licenses/>.
22 ; See the GCC internals manual (options.texi) for a description of this file's format.
24 ; Please try to keep this file in ASCII collating order.
35 ; Not used directly to control optimizations, only to save -Ofast
36 ; setting for "optimize" attributes.
40 ; True if this is the lto front end. This is used to disable gimple
41 ; generation and lowering passes that are normally run on the output
42 ; of a front end. These passes must be bypassed for lto since they
43 ; have already been done before the gimple was written.
47 ; 0 means straightforward implementation of complex divide acceptable.
48 ; 1 means wide ranges of inputs must work for complex divide.
49 ; 2 means C99-like requirements for complex multiply and divide.
51 int flag_complex_method = 1
53 ; Nonzero if subexpressions must be evaluated from left-to-right.
55 int flag_evaluation_order = 0
57 ; Language specific warning pass for unused results.
59 bool flag_warn_unused_result = false
64 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
68 ; True to warn about any objects definitions whose size is larger
69 ; than N bytes. Also want about function definitions whose returned
70 ; values are larger than N bytes, where N is 'larger_than_size'.
75 HOST_WIDE_INT larger_than_size
77 ; True to warn about any function whose frame size is larger
80 bool warn_frame_larger_than
83 HOST_WIDE_INT frame_larger_than_size
85 ; Nonzero means we should be saving declaration info into a .X file.
87 int flag_gen_aux_info = 0
89 ; Nonzero if we are compiling code for a shared library, zero for
94 ; These two are really VEC(char_p,heap) *.
97 void *flag_instrument_functions_exclude_functions
100 void *flag_instrument_functions_exclude_files
102 ; Generic structs (e.g. templates not explicitly specialized)
103 ; may not have a compilation unit associated with them, and so
104 ; may need to be treated differently from ordinary structs.
106 ; Structs only handled by reference (indirectly), will also usually
107 ; not need as much debugging information.
110 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
113 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 ; True if we should exit after parsing options.
117 bool exit_after_options
119 ; Type(s) of debugging information we are producing (if any). See
120 ; flag-types.h for the definitions of the different possible types of
121 ; debugging information.
123 enum debug_info_type write_symbols = NO_DEBUG
125 ; Level of debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
130 ; Nonzero means use GNU-only extensions in the generated symbolic
131 ; debugging information. Currently, this only has an effect when
132 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
134 bool use_gnu_debug_info_extensions
136 ; Original value of maximum field alignment in bytes, specified via
137 ; -fpack-struct=<value>.
139 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
142 enum vect_verbosity_levels user_vect_verbosity_level = MAX_VERBOSITY_LEVEL
144 ; Type of stack check.
146 enum stack_check_type flag_stack_check = NO_STACK_CHECK
148 ; True if stack usage information needs to be computed.
150 bool flag_stack_usage_info = false
152 ; -dA causes debug commentary information to be produced in
153 ; the generated assembly code (to make it more readable). This option
154 ; is generally only of use to those who actually need to read the
155 ; generated assembly code (perhaps while debugging the compiler itself).
156 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
157 ; to be a catchall for printing debug information in the assembler file.
161 ; -dP causes the rtl to be emitted as a comment in assembly.
163 int flag_dump_rtl_in_asm
165 ; Whether -da was passed (used only in handle_common_deferred_options).
167 bool flag_dump_all_passed
169 ; Other flags saying which kinds of debugging dump have been requested.
172 int rtl_dump_and_exit
175 int flag_print_asm_name
178 enum graph_dump_types graph_dump_format = no_graph
180 ; Name of top-level original source file (what was input to cpp).
181 ; This comes from the #-command at the beginning of the actual input.
182 ; If there isn't any there, then this is the cc1 input file name.
184 const char *main_input_filename
186 ; Pointer to base name in main_input_filename, with directories and a
187 ; single final extension removed, and the length of this base
191 const char *main_input_basename
194 int main_input_baselength
196 ; Which options have been printed by --help.
200 ; Which enums have been printed by --help. 0 = not printed, no
201 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
204 char *help_enum_printed
206 ; The number of columns for --help output.
208 unsigned int help_columns
210 ; Whether this options structure has been through finish_options
212 bool flag_opts_finished
224 Driver Alias(coverage)
230 Common Separate Alias(d)
233 Common Joined Alias(d)
236 Common Separate Alias(dumpbase)
239 Common Separate Alias(dumpdir)
242 Driver Separate Alias(e)
245 Driver Joined Alias(e)
248 Common Warning Alias(Wextra)
251 Driver Separate Alias(Xassembler)
254 Driver JoinedOrMissing Alias(Xassembler)
257 Driver Separate Alias(Xlinker)
260 Driver JoinedOrMissing Alias(Xlinker)
263 Driver Separate Alias(u)
266 Driver Joined Alias(u)
269 Common Driver Var(help_flag)
270 Display this information
273 Common Driver Report Joined
274 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
277 Driver Separate Alias(x)
280 Driver Joined Alias(x)
283 Driver Separate Alias(L)
286 Driver Joined Alias(L)
288 -no-canonical-prefixes
289 Driver Alias(no-canonical-prefixes)
291 -no-standard-libraries
292 Driver Alias(nostdlib)
295 Driver Var(no_sysroot_suffix)
304 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
307 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
310 Driver Alias(pass-exit-codes)
313 Common Alias(Wpedantic)
316 Common Alias(pedantic-errors)
325 Driver Separate Alias(B)
328 Driver JoinedOrMissing Alias(B)
334 Driver Separate Alias(print-file-name=)
337 Driver JoinedOrMissing Alias(print-file-name=)
339 -print-libgcc-file-name
340 Driver Alias(print-libgcc-file-name)
342 -print-multi-directory
343 Driver Alias(print-multi-directory)
346 Driver Alias(print-multi-lib)
348 -print-multi-os-directory
349 Driver Alias(print-multi-os-directory)
352 Driver Separate Alias(print-prog-name=)
355 Driver JoinedOrMissing Alias(print-prog-name=)
358 Driver Alias(print-search-dirs)
361 Driver Alias(print-sysroot)
363 -print-sysroot-headers-suffix
364 Driver Alias(print-sysroot-headers-suffix)
370 Driver Alias(save-temps)
376 Driver Separate Alias(specs=)
379 Driver Joined Alias(specs=)
385 Driver Alias(symbolic)
389 Alias for --help=target
397 ;; The driver used to convert options such as --help into forms such
398 ;; as -fhelp; the following four entries are for compatibility with
399 ;; any direct uses of those (undocumented) -f forms
401 Common Driver Alias(-help)
404 Common Driver Joined Alias(-help=)
407 Common Driver Alias(-target-help)
410 Common Driver Alias(-version)
414 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
417 Common Joined Alias(-param)
420 Driver Separate Alias(-sysroot=)
423 Driver JoinedOrMissing
429 Driver Joined Separate
435 Driver Joined Separate
441 Common JoinedOrMissing Optimization
442 -O<number> Set optimization level to <number>
446 Optimize for space rather than speed
450 Optimize for speed disregarding exact standards compliance
462 Driver Joined Separate
468 Driver Joined Separate
489 Common RejectNegative Warning Alias(Wextra)
490 This switch is deprecated; use -Wextra instead
493 Driver JoinedOrMissing
496 Driver JoinedOrMissing
499 Driver JoinedOrMissing
502 Common Var(warn_aggregate_return) Warning
503 Warn about returning structures, unions or arrays
506 Common Var(warn_array_bounds) Warning
507 Warn if an array is accessed out of bounds
510 Common Var(warn_attributes) Init(1) Warning
511 Warn about inappropriate attribute usage
514 Common Var(warn_cast_align) Warning
515 Warn about pointer casts which increase alignment
518 Common Var(warn_cpp) Init(1) Warning
519 Warn when a #warning directive is encountered
521 Wdeprecated-declarations
522 Common Var(warn_deprecated_decl) Init(1) Warning
523 Warn about uses of __attribute__((deprecated)) declarations
525 Wdisabled-optimization
526 Common Var(warn_disabled_optimization) Warning
527 Warn when an optimization pass is disabled
530 Common Var(warnings_are_errors)
531 Treat all warnings as errors
535 Treat specified warning as error
538 Common Var(extra_warnings) Warning
539 Print extra (possibly unwanted) warnings
542 Common Var(flag_fatal_errors)
543 Exit on the first error occurred
546 Common RejectNegative Joined UInteger
547 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
550 Common Var(warn_free_nonheap_object) Init(1) Warning
551 Warn when attempting to free a non-heap object
554 Common Var(warn_inline) Warning
555 Warn when an inlined function cannot be inlined
557 Winvalid-memory-model
558 Common Var(warn_invalid_memory_model) Init(1) Warning
559 Warn when an atomic memory model parameter is known to be outside the valid range.
562 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
565 Common RejectNegative Joined UInteger Warning
566 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
568 Wunsafe-loop-optimizations
569 Common Var(warn_unsafe_loop_optimizations) Warning
570 Warn if the loop cannot be optimized due to nontrivial assumptions.
573 Common Alias(Wsuggest-attribute=noreturn)
576 Common Var(warn_overflow) Init(1) Warning
577 Warn about overflow in arithmetic expressions
580 Common Var(warn_packed) Warning
581 Warn when the packed attribute has no effect on struct layout
584 Common Var(warn_padded) Warning
585 Warn when padding is required to align structure members
588 Common Var(pedantic) Warning
589 Issue warnings needed for strict compliance to the standard
592 Common Var(warn_shadow) Warning
593 Warn when one local variable shadows another
596 Common Var(warn_stack_protect) Warning
597 Warn when not issuing stack smashing protection for some reason
600 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
601 Warn if stack usage might be larger than specified amount
605 Warn about code which might break strict aliasing rules
608 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Init(-1) Warning
609 Warn about code which might break strict aliasing rules
613 Warn about optimizations that assume that signed overflow is undefined
616 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Init(-1) Warning
617 Warn about optimizations that assume that signed overflow is undefined
619 Wsuggest-attribute=const
620 Common Var(warn_suggest_attribute_const) Warning
621 Warn about functions which might be candidates for __attribute__((const))
623 Wsuggest-attribute=pure
624 Common Var(warn_suggest_attribute_pure) Warning
625 Warn about functions which might be candidates for __attribute__((pure))
627 Wsuggest-attribute=noreturn
628 Common Var(warn_suggest_attribute_noreturn) Warning
629 Warn about functions which might be candidates for __attribute__((noreturn))
632 Common Var(warn_switch) Warning
633 Warn about enumerated switches, with no default, missing a case
636 Common Var(warn_switch_default) Warning
637 Warn about enumerated switches missing a \"default:\" statement
640 Common Var(warn_switch_enum) Warning
641 Warn about all enumerated switches missing a specific case
644 Common Var(warn_system_headers) Warning
645 Do not suppress warnings from system headers
648 Common Var(warn_trampolines) Warning
649 Warn whenever a trampoline is generated
652 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
653 Warn if a comparison is always true or always false due to the limited range of the data type
656 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
657 Warn about uninitialized automatic variables
660 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
661 Warn about maybe uninitialized automatic variables
665 Does nothing. Preserved for backward compatibility.
668 Common Var(warn_unused) Init(0) Warning
669 Enable all -Wunused- warnings
671 Wunused-but-set-parameter
672 Common Var(warn_unused_but_set_parameter) Init(-1) Warning
673 Warn when a function parameter is only set, otherwise unused
675 Wunused-but-set-variable
676 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
677 Warn when a variable is only set, otherwise unused
680 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
681 Warn when a function is unused
684 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
685 Warn when a label is unused
688 Common Var(warn_unused_parameter) Init(-1) Warning
689 Warn when a function parameter is unused
692 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
693 Warn when an expression value is unused
696 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
697 Warn when a variable is unused
700 Common Var(warn_coverage_mismatch) Init(1) Warning
701 Warn in case profiles in -fprofile-use do not match
703 Wvector-operation-performance
704 Common Var(warn_vector_operation_performance) Warning
705 Warn when a vector operation is compiled outside the SIMD
720 Common Separate Var(aux_info_file_name)
721 -aux-info <file> Emit declaration information into <file>
724 Common Joined Alias(aux-info)
727 Common Separate RejectDriver Var(aux_base_name)
730 Common Separate RejectDriver
740 -d<letters> Enable dumps from specific passes of the compiler
743 Common Separate Var(dump_base_name)
744 -dumpbase <file> Set the file basename to be used for dumps
747 Common Separate Var(dump_dir_name)
748 -dumpdir <dir> Set the directory name to be used for dumps
760 Driver Joined Separate
762 ; This option has historically been passed down to the linker by an
763 ; accident of a %{e*} spec, so ensure it continues to be passed down
764 ; as a single option. The supported option for this purpose is
765 ; -rdynamic. See PR 47390.
769 ; The version of the C++ ABI in use. The following values are allowed:
771 ; 0: The version of the ABI believed most conformant with the C++ ABI
772 ; specification. This ABI may change as bugs are discovered and fixed.
773 ; Therefore, 0 will not necessarily indicate the same ABI in different
776 ; 1: The version of the ABI first used in G++ 3.2.
778 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
780 ; 3: The version of the ABI that fixes the missing underscore
781 ; in template non-type arguments of pointer type.
783 ; 4: The version of the ABI that introduces unambiguous mangling of
784 ; vector types. First selectable in G++ 4.5.
786 ; 5: The version of the ABI that ignores attribute const/noreturn
787 ; in function pointer mangling, and corrects mangling of decltype and
788 ; function parameters used in other parameters and the return type.
789 ; First selectable in G++ 4.6.
791 ; 6: The version of the ABI that doesn't promote scoped enums to int and
792 ; changes the mangling of template argument packs, const/static_cast,
793 ; prefix ++ and --, and a class scope function used as a template
795 ; First selectable in G++ 4.7.
797 ; 7: The version of the ABI that treats nullptr_t as a builtin type.
798 ; First selectable in G++ 4.8.
799 ; Additional positive integers will be assigned as new versions of
800 ; the ABI become the default version of the ABI.
802 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
805 Common Report Var(align_functions,0) Optimization UInteger
806 Align the start of functions
809 Common RejectNegative Joined UInteger Var(align_functions)
812 Common Report Var(align_jumps,0) Optimization UInteger
813 Align labels which are only reached by jumping
816 Common RejectNegative Joined UInteger Var(align_jumps)
819 Common Report Var(align_labels,0) Optimization UInteger
823 Common RejectNegative Joined UInteger Var(align_labels)
826 Common Report Var(align_loops,0) Optimization UInteger
827 Align the start of loops
830 Common RejectNegative Joined UInteger Var(align_loops)
834 Does nothing. Preserved for backward compatibility.
838 Does nothing. Preserved for backward compatibility.
840 fargument-noalias-global
842 Does nothing. Preserved for backward compatibility.
844 fargument-noalias-anything
846 Does nothing. Preserved for backward compatibility.
848 fasynchronous-unwind-tables
849 Common Report Var(flag_asynchronous_unwind_tables) Optimization
850 Generate unwind tables that are exact at each instruction boundary
853 Common Report Var(flag_auto_inc_dec) Init(1)
854 Generate auto-inc/dec instructions
856 ; -fcheck-bounds causes gcc to generate array bounds checks.
857 ; For C, C++ and ObjC: defaults off.
858 ; For Java: defaults to on.
859 ; For Fortran: defaults to off.
861 Common Report Var(flag_bounds_check)
862 Generate code to check bounds before indexing arrays
865 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
866 Replace add, compare, branch with branch on count register
868 fbranch-probabilities
869 Common Report Var(flag_branch_probabilities) Optimization
870 Use profiling information for branch probabilities
872 fbranch-target-load-optimize
873 Common Report Var(flag_branch_target_load_optimize) Optimization
874 Perform branch target load optimization before prologue / epilogue threading
876 fbranch-target-load-optimize2
877 Common Report Var(flag_branch_target_load_optimize2) Optimization
878 Perform branch target load optimization after prologue / epilogue threading
881 Common Report Var(flag_btr_bb_exclusive) Optimization
882 Restrict target load migration not to re-use registers in any basic block
885 Common Joined RejectNegative Var(common_deferred_options) Defer
886 -fcall-saved-<register> Mark <register> as being preserved across functions
889 Common Joined RejectNegative Var(common_deferred_options) Defer
890 -fcall-used-<register> Mark <register> as being corrupted by function calls
892 ; Nonzero for -fcaller-saves: allocate values in regs that need to
893 ; be saved across function calls, if that produces overall better code.
894 ; Optional now, so people can test it.
896 Common Report Var(flag_caller_saves) Optimization
897 Save registers around function calls
900 Common Report Var(flag_check_data_deps)
901 Compare the results of several data dependence analyzers.
903 fcombine-stack-adjustments
904 Common Report Var(flag_combine_stack_adjustments) Optimization
905 Looks for opportunities to reduce stack adjustments and stack references.
908 Common Report Var(flag_no_common,0) Optimization
909 Do not put uninitialized globals in the common section
913 ; Converted by the driver to -fcompare-debug= options.
916 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
917 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
919 fcompare-debug-second
920 Common Driver RejectNegative Var(flag_compare_debug)
921 Run only the second compilation of -fcompare-debug
924 Common Report Var(flag_compare_elim_after_reload) Optimization
925 Perform comparison elimination after register allocation has finished
928 Common Var(flag_conserve_stack) Optimization
929 Do not perform optimizations increasing noticeably stack usage
932 Common Report Var(flag_cprop_registers) Optimization
933 Perform a register copy-propagation optimization pass
936 Common Report Var(flag_crossjumping) Optimization
937 Perform cross-jumping optimization
940 Common Report Var(flag_cse_follow_jumps) Optimization
941 When running CSE, follow jumps to their targets
945 Does nothing. Preserved for backward compatibility.
948 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
949 Omit range reduction step when performing complex division
952 Common Report Var(flag_cx_fortran_rules) Optimization
953 Complex multiplication and division follow Fortran rules
956 Common Report Var(flag_data_sections) Optimization
957 Place data items into their own section
960 Common Report Var(common_deferred_options) Defer
961 List all available debugging counters with their limits and counts.
964 Common RejectNegative Joined Var(common_deferred_options) Defer
965 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
968 Common Joined RejectNegative Var(common_deferred_options) Defer
969 Map one directory name to another in debug information
972 Common Report Var(flag_debug_types_section) Init(0)
973 Output .debug_types section when using DWARF v4 debuginfo.
975 ; Nonzero for -fdefer-pop: don't pop args after each function call
976 ; instead save them up to pop many calls' args with one insns.
978 Common Report Var(flag_defer_pop) Optimization
979 Defer popping functions args from stack until later
982 Common Report Var(flag_delayed_branch) Optimization
983 Attempt to fill delay slots of branch instructions
985 fdelete-dead-exceptions
986 Common Report Var(flag_delete_dead_exceptions) Init(0)
987 Delete dead instructions that may throw exceptions
989 fdelete-null-pointer-checks
990 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
991 Delete useless null pointer checks
994 Common Report Var(flag_devirtualize) Optimization
995 Try to convert virtual calls to direct ones.
997 fdiagnostics-show-location=
998 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
999 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1001 ; Required for these enum values.
1006 Name(diagnostic_prefixing_rule) Type(int)
1009 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1012 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1014 fdiagnostics-show-caret
1015 Common Var(flag_diagnostics_show_caret) Init(1)
1016 Show the source line with a caret indicating the column
1018 fdiagnostics-show-option
1019 Common Var(flag_diagnostics_show_option) Init(1)
1020 Amend appropriate diagnostic messages with the command line option that controls them
1023 Common Joined RejectNegative Var(common_deferred_options) Defer
1024 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1027 Common Joined RejectNegative Var(common_deferred_options) Defer
1028 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1031 Common Joined RejectNegative Var(common_deferred_options) Defer
1032 -fdump-<type> Dump various compiler internals to a file
1035 Driver RejectNegative
1038 Common RejectNegative Joined Var(flag_dump_final_insns)
1039 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1042 Common RejectNegative Joined Var(flag_dump_go_spec)
1043 -fdump-go-spec=filename Write all declarations to file as Go code
1046 Common Report Var(flag_dump_noaddr)
1047 Suppress output of addresses in debugging dumps
1050 Common Var(flag_dump_passes) Init(0)
1051 Dump optimization passes
1054 Common Report Var(flag_dump_unnumbered)
1055 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1057 fdump-unnumbered-links
1058 Common Report Var(flag_dump_unnumbered_links)
1059 Suppress output of previous and next insn numbers in debugging dumps
1062 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1063 Enable CFI tables via GAS assembler directives.
1066 Common Report Var(flag_early_inlining) Init(1) Optimization
1067 Perform early inlining
1069 feliminate-dwarf2-dups
1070 Common Report Var(flag_eliminate_dwarf2_dups)
1071 Perform DWARF2 duplicate elimination
1074 Common Report Var(flag_ipa_sra) Init(0) Optimization
1075 Perform interprocedural reduction of aggregates
1077 feliminate-unused-debug-symbols
1078 Common Report Var(flag_debug_only_used_symbols)
1079 Perform unused type elimination in debug info
1081 feliminate-unused-debug-types
1082 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1083 Perform unused type elimination in debug info
1085 femit-class-debug-always
1086 Common Report Var(flag_emit_class_debug_always) Init(0)
1087 Do not suppress C++ class debug information.
1090 Common Report Var(flag_exceptions) Optimization
1091 Enable exception handling
1093 fexpensive-optimizations
1094 Common Report Var(flag_expensive_optimizations) Optimization
1095 Perform a number of minor, expensive optimizations
1098 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1099 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1102 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1105 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1108 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1114 Common Var(flag_fat_lto_objects) Init(1)
1115 Output lto objects containing both the intermediate language and binary output.
1118 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1119 Assume no NaNs or infinities are generated
1122 Common Joined RejectNegative Var(common_deferred_options) Defer
1123 -ffixed-<register> Mark <register> as being unavailable to the compiler
1126 Common Report Var(flag_float_store) Optimization
1127 Don't allocate floats and doubles in extended-precision registers
1131 Does nothing. Preserved for backward compatibility.
1134 Common Report Var(flag_forward_propagate) Optimization
1135 Perform a forward propagation pass on RTL
1138 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1139 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1142 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1145 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1147 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1149 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1152 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1154 ; Nonzero means don't put addresses of constant functions in registers.
1155 ; Used for compiling the Unix kernel, where strange substitutions are
1156 ; done on the assembly output.
1158 Common Report Var(flag_no_function_cse,0)
1159 Allow function addresses to be held in registers
1162 Common Report Var(flag_function_sections)
1163 Place each function into its own section
1166 Common Report Var(flag_gcse) Optimization
1167 Perform global common subexpression elimination
1170 Common Report Var(flag_gcse_lm) Init(1) Optimization
1171 Perform enhanced load motion during global common subexpression elimination
1174 Common Report Var(flag_gcse_sm) Init(0) Optimization
1175 Perform store motion after global common subexpression elimination
1178 Common Report Var(flag_gcse_las) Init(0) Optimization
1179 Perform redundant load after store elimination in global common subexpression
1183 Common Report Var(flag_gcse_after_reload) Optimization
1184 Perform global common subexpression elimination after register allocation
1187 ; This option is not documented yet as its semantics will change.
1189 Common Report Var(flag_graphite)
1190 Enable in and out of Graphite representation
1193 Common Report Var(flag_graphite_identity) Optimization
1194 Enable Graphite Identity transformation
1196 fhoist-adjacent-loads
1197 Common Report Var(flag_hoist_adjacent_loads) Optimization
1198 Enable hoisting adjacent loads to encourage generating conditional move
1201 floop-parallelize-all
1202 Common Report Var(flag_loop_parallelize_all) Optimization
1203 Mark all loops as parallel
1206 Common Report Var(flag_loop_strip_mine) Optimization
1207 Enable Loop Strip Mining transformation
1210 Common Report Var(flag_loop_interchange) Optimization
1211 Enable Loop Interchange transformation
1214 Common Report Var(flag_loop_block) Optimization
1215 Enable Loop Blocking transformation
1218 Common Report Var(flag_tm)
1219 Enable support for GNU transactional memory
1223 Does nothing. Preserved for backward compatibility.
1226 Common Report Var(flag_loop_optimize_isl) Optimization
1227 Enable the ISL based loop nest optimizer
1229 fstrict-volatile-bitfields
1230 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1231 Force bitfield accesses to match their type width
1233 fguess-branch-probability
1234 Common Report Var(flag_guess_branch_prob) Optimization
1235 Enable guessing of branch probabilities
1237 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1238 ; Generate position-independent code for executables if possible
1239 ; On SVR4 targets, it also controls whether or not to emit a
1240 ; string identifying the compiler.
1242 Common Report Var(flag_no_ident,0)
1243 Process #ident directives
1246 Common Report Var(flag_if_conversion) Optimization
1247 Perform conversion of conditional jumps to branchless equivalents
1250 Common Report Var(flag_if_conversion2) Optimization
1251 Perform conversion of conditional jumps to conditional execution
1254 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1255 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1258 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1261 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1264 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1267 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1269 ftree-loop-if-convert
1270 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1271 Convert conditional jumps in innermost loops to branchless equivalents
1273 ftree-loop-if-convert-stores
1274 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1275 Also if-convert conditional jumps containing memory writes
1277 ; -finhibit-size-directive inhibits output of .size for ELF.
1278 ; This is used only for compiling crtstuff.c,
1279 ; and it may be extended to other effects
1280 ; needed for crtstuff.c on other systems.
1281 finhibit-size-directive
1282 Common Report Var(flag_inhibit_size_directive)
1283 Do not generate .size directives
1286 Common Report Var(flag_indirect_inlining)
1287 Perform indirect inlining
1289 ; General flag to enable inlining. Specifying -fno-inline will disable
1290 ; all inlining apart from always-inline functions.
1292 Common Report Var(flag_no_inline,0) Init(0)
1293 Enable inlining of function declared \"inline\", disabling disables all inlining
1295 finline-small-functions
1296 Common Report Var(flag_inline_small_functions) Optimization
1297 Integrate functions into their callers when code size is known not to grow
1300 Common Report Var(flag_inline_functions) Optimization
1301 Integrate functions not declared \"inline\" into their callers when profitable
1303 finline-functions-called-once
1304 Common Report Var(flag_inline_functions_called_once) Optimization
1305 Integrate functions only required by their single caller
1308 Common RejectNegative Joined Alias(finline-limit=)
1311 Common RejectNegative Joined UInteger
1312 -finline-limit=<number> Limit the size of inlined functions to <number>
1315 Common Report Var(flag_inline_atomics) Init(1) Optimization
1316 Inline __atomic operations when a lock free instruction sequence is available.
1318 finstrument-functions
1319 Common Report Var(flag_instrument_function_entry_exit)
1320 Instrument function entry and exit with profiling calls
1322 finstrument-functions-exclude-function-list=
1323 Common RejectNegative Joined
1324 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1326 finstrument-functions-exclude-file-list=
1327 Common RejectNegative Joined
1328 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1331 Common Report Var(flag_ipa_cp) Optimization
1332 Perform Interprocedural constant propagation
1335 Common Report Var(flag_ipa_cp_clone) Optimization
1336 Perform cloning to make Interprocedural constant propagation stronger
1339 Common Report Var(flag_ipa_profile) Init(0) Optimization
1340 Perform interprocedural profile propagation
1343 Common Report Var(flag_ipa_pta) Init(0) Optimization
1344 Perform interprocedural points-to analysis
1347 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1348 Discover pure and const functions
1351 Common Report Var(flag_ipa_reference) Init(0) Optimization
1352 Discover readonly and non addressable static variables
1356 Does nothing. Preserved for backward compatibility.
1360 Does nothing. Preserved for backward compatibility.
1363 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1364 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1367 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1370 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1373 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1376 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1377 -fira-region=[one|all|mixed] Set regions for IRA
1380 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1383 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1386 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1389 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1392 Common Report Var(flag_ira_loop_pressure)
1393 Use IRA based register pressure calculation
1394 in RTL loop optimizations.
1396 fira-share-save-slots
1397 Common Report Var(flag_ira_share_save_slots) Init(1)
1398 Share slots for saving different hard registers.
1400 fira-share-spill-slots
1401 Common Report Var(flag_ira_share_spill_slots) Init(1)
1402 Share stack slots for spilled pseudo-registers.
1405 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1406 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1409 Common Report Var(flag_ivopts) Init(1) Optimization
1410 Optimize induction variables on trees
1413 Common Var(flag_jump_tables) Init(1) Optimization
1414 Use jump tables for sufficiently large switch statements
1416 fkeep-inline-functions
1417 Common Report Var(flag_keep_inline_functions)
1418 Generate code for functions even if they are fully inlined
1421 Common Report Var(flag_keep_static_consts) Init(1)
1422 Emit static const variables even if they are not used
1425 Common Report Var(flag_leading_underscore) Init(-1)
1426 Give external symbols a leading underscore
1430 Does nothing. Preserved for backward compatibility.
1434 Enable link-time optimization.
1437 Common RejectNegative Joined Var(flag_lto)
1438 Link-time optimization with number of parallel jobs or jobserver.
1441 Common Var(flag_lto_partition_1to1)
1442 Partition functions and vars at linktime based on object files they originate from
1444 flto-partition=balanced
1445 Common Var(flag_lto_partition_balanced)
1446 Partition functions and vars at linktime into approximately same sized buckets
1449 Common Var(flag_lto_partition_none)
1450 Disable partioning and streaming
1452 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1453 flto-compression-level=
1454 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1455 -flto-compression-level=<number> Use zlib compression level <number> for IL
1458 Common Report Var(flag_lto_report) Init(0)
1459 Report various link-time optimization statistics
1462 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1463 Set errno after built-in math functions
1466 Common Joined RejectNegative UInteger Var(flag_max_errors)
1467 -fmax-errors=<number> Maximum number of errors to report
1470 Common Report Var(mem_report)
1471 Report on permanent memory allocation
1474 Common Report Var(mem_report_wpa)
1475 Report on permanent memory allocation in WPA only
1477 ; This will attempt to merge constant section constants, if 1 only
1478 ; string constants and constants from constant pool, if 2 also constant
1480 fmerge-all-constants
1481 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1482 Attempt to merge identical constants and constant variables
1485 Common Report Var(flag_merge_constants,1) Optimization
1486 Attempt to merge identical constants across compilation units
1488 fmerge-debug-strings
1489 Common Report Var(flag_merge_debug_strings) Init(1)
1490 Attempt to merge identical debug strings across compilation units
1493 Common RejectNegative Joined UInteger
1494 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1497 Common Report Var(flag_modulo_sched) Optimization
1498 Perform SMS based modulo scheduling before the first scheduling pass
1500 fmodulo-sched-allow-regmoves
1501 Common Report Var(flag_modulo_sched_allow_regmoves)
1502 Perform SMS based modulo scheduling with register moves allowed
1504 fmove-loop-invariants
1505 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1506 Move loop invariant computations out of loops
1509 Common Var(flag_dce) Init(1) Optimization
1510 Use the RTL dead code elimination pass
1513 Common Var(flag_dse) Init(1) Optimization
1514 Use the RTL dead store elimination pass
1516 freschedule-modulo-scheduled-loops
1517 Common Report Var(flag_resched_modulo_sched) Optimization
1518 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1520 fnon-call-exceptions
1521 Common Report Var(flag_non_call_exceptions) Optimization
1522 Support synchronous non-call exceptions
1525 Common Report Var(flag_omit_frame_pointer) Optimization
1526 When possible do not generate stack frames
1528 foptimize-register-move
1529 Common Report Var(flag_regmove) Optimization
1530 Do the full register move optimization pass
1532 foptimize-sibling-calls
1533 Common Report Var(flag_optimize_sibling_calls) Optimization
1534 Optimize sibling and tail recursive calls
1537 Common Report Var(flag_partial_inlining)
1538 Perform partial inlining
1541 Common Report Var(pre_ipa_mem_report)
1542 Report on memory allocation before interprocedural optimization
1544 fpost-ipa-mem-report
1545 Common Report Var(post_ipa_mem_report)
1546 Report on memory allocation before interprocedural optimization
1549 Common Report Var(flag_pack_struct) Optimization
1550 Pack structure members together without holes
1553 Common RejectNegative Joined UInteger Optimization
1554 -fpack-struct=<number> Set initial maximum structure member alignment
1557 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1558 Return small aggregates in memory, not registers
1561 Common Report Var(flag_peel_loops) Optimization
1562 Perform loop peeling
1565 Common Report Var(flag_no_peephole,0) Optimization
1566 Enable machine specific peephole optimizations
1569 Common Report Var(flag_peephole2) Optimization
1570 Enable an RTL peephole pass before sched2
1573 Common Report Var(flag_pic,2)
1574 Generate position-independent code if possible (large mode)
1577 Common Report Var(flag_pie,2)
1578 Generate position-independent code for executables if possible (large mode)
1581 Common Report Var(flag_pic,1)
1582 Generate position-independent code if possible (small mode)
1585 Common Report Var(flag_pie,1)
1586 Generate position-independent code for executables if possible (small mode)
1589 Common Joined RejectNegative Var(common_deferred_options) Defer
1590 Specify a plugin to load
1593 Common Joined RejectNegative Var(common_deferred_options) Defer
1594 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1596 fpredictive-commoning
1597 Common Report Var(flag_predictive_commoning) Optimization
1598 Run predictive commoning optimization.
1600 fprefetch-loop-arrays
1601 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1602 Generate prefetch instructions, if available, for arrays in loops
1605 Common Report Var(profile_flag)
1606 Enable basic program profiling code
1609 Common Report Var(profile_arc_flag)
1610 Insert arc-based program profiling code
1613 Common Joined RejectNegative Var(profile_data_prefix)
1614 Set the top-level directory for storing the profile data.
1615 The default is 'pwd'.
1618 Common Report Var(flag_profile_correction)
1619 Enable correction of flow inconsistent profile data input
1623 Enable common options for generating profile info for profile feedback directed optimizations
1626 Common Joined RejectNegative
1627 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1630 Common Var(flag_profile_use)
1631 Enable common options for performing profile feedback directed optimizations
1634 Common Joined RejectNegative
1635 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1638 Common Report Var(flag_profile_values)
1639 Insert code to profile values of expressions
1642 Common Var(common_deferred_options) Defer
1645 Common Joined RejectNegative Var(common_deferred_options) Defer
1646 -frandom-seed=<string> Make compile reproducible using <string>
1648 ; This switch causes the command line that was used to create an
1649 ; object file to be recorded into the object file. The exact format
1650 ; of this recording is target and binary file format dependent.
1651 ; It is related to the -fverbose-asm switch, but that switch only
1652 ; records information in the assembler output file as comments, so
1653 ; they never reach the object file.
1654 frecord-gcc-switches
1655 Common Report Var(flag_record_gcc_switches)
1656 Record gcc command line switches in the object file.
1659 Common Report Var(flag_pcc_struct_return,0) Optimization
1660 Return small aggregates in registers
1663 Common Report Var(flag_regmove) Optimization
1664 Enables a register move optimization
1667 Common Report Var(flag_rename_registers) Init(2) Optimization
1668 Perform a register renaming optimization pass
1671 Common Report Var(flag_reorder_blocks) Optimization
1672 Reorder basic blocks to improve code placement
1674 freorder-blocks-and-partition
1675 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1676 Reorder basic blocks and partition into hot and cold sections
1679 Common Report Var(flag_reorder_functions) Optimization
1680 Reorder functions to improve code placement
1682 frerun-cse-after-loop
1683 Common Report Var(flag_rerun_cse_after_loop) Optimization
1684 Add a common subexpression elimination pass after loop optimizations
1688 Does nothing. Preserved for backward compatibility.
1691 Common Report Var(flag_rounding_math) Optimization SetByCombined
1692 Disable optimizations that assume default FP rounding behavior
1695 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1696 Enable scheduling across basic blocks
1699 Common Report Var(flag_sched_pressure) Init(0) Optimization
1700 Enable register pressure sensitive insn scheduling
1703 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1704 Allow speculative motion of non-loads
1707 Common Report Var(flag_schedule_speculative_load) Optimization
1708 Allow speculative motion of some loads
1710 fsched-spec-load-dangerous
1711 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1712 Allow speculative motion of more loads
1715 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1716 -fsched-verbose=<number> Set the verbosity level of the scheduler
1718 fsched2-use-superblocks
1719 Common Report Var(flag_sched2_use_superblocks) Optimization
1720 If scheduling post reload, do superblock scheduling
1724 Does nothing. Preserved for backward compatibility.
1727 Common Report Var(flag_schedule_insns) Optimization
1728 Reschedule instructions before register allocation
1731 Common Report Var(flag_schedule_insns_after_reload) Optimization
1732 Reschedule instructions after register allocation
1734 ; This flag should be on when a target implements non-trivial
1735 ; scheduling hooks, maybe saving some information for its own sake.
1736 ; On IA64, for example, this is used for correct bundling.
1737 fselective-scheduling
1738 Common Report Var(flag_selective_scheduling) Optimization
1739 Schedule instructions using selective scheduling algorithm
1741 fselective-scheduling2
1742 Common Report Var(flag_selective_scheduling2) Optimization
1743 Run selective scheduling after reload
1745 fsel-sched-pipelining
1746 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1747 Perform software pipelining of inner loops during selective scheduling
1749 fsel-sched-pipelining-outer-loops
1750 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1751 Perform software pipelining of outer loops during selective scheduling
1753 fsel-sched-reschedule-pipelined
1754 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1755 Reschedule pipelined regions without pipelining
1757 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1758 ; of stalled insns into the ready list.
1759 fsched-stalled-insns
1760 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1761 Allow premature scheduling of queued insns
1763 fsched-stalled-insns=
1764 Common RejectNegative Joined UInteger
1765 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1767 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1768 ; be examined for a dependency on a stalled insn that is candidate for
1769 ; premature removal from the queue of stalled insns into the ready list (has
1770 ; an effect only if the flag 'sched_stalled_insns' is set).
1771 fsched-stalled-insns-dep
1772 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1773 Set dependence distance checking in premature scheduling of queued insns
1775 fsched-stalled-insns-dep=
1776 Common RejectNegative Joined UInteger
1777 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1779 fsched-group-heuristic
1780 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1781 Enable the group heuristic in the scheduler
1783 fsched-critical-path-heuristic
1784 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1785 Enable the critical path heuristic in the scheduler
1787 fsched-spec-insn-heuristic
1788 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1789 Enable the speculative instruction heuristic in the scheduler
1791 fsched-rank-heuristic
1792 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1793 Enable the rank heuristic in the scheduler
1795 fsched-last-insn-heuristic
1796 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1797 Enable the last instruction heuristic in the scheduler
1799 fsched-dep-count-heuristic
1800 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1801 Enable the dependent count heuristic in the scheduler
1804 Common Report Var(flag_section_anchors) Optimization
1805 Access data in the same section from shared anchor points
1809 Does nothing. Preserved for backward compatibility.
1813 Does nothing. Preserved for backward compatibility.
1816 Common Report Var(flag_ree) Init(0)
1817 Turn on Redundant Extensions Elimination pass.
1820 Common Report Var(flag_show_column) Init(1)
1821 Show column numbers in diagnostics, when available. Default on
1824 Common Report Var(flag_shrink_wrap) Optimization
1825 Emit function prologues only before parts of the function that need it,
1826 rather than at the top of the function.
1829 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1830 Disable optimizations observable by IEEE signaling NaNs
1833 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1834 Disable floating point optimizations that ignore the IEEE signedness of zero
1836 fsingle-precision-constant
1837 Common Report Var(flag_single_precision_constant) Optimization
1838 Convert floating point constants to single precision constants
1840 fsplit-ivs-in-unroller
1841 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1842 Split lifetimes of induction variables when loops are unrolled
1845 Common Report Var(flag_split_stack) Init(-1)
1846 Generate discontiguous stack frames
1849 Common Report Var(flag_split_wide_types) Optimization
1850 Split wide types into independent registers
1852 fvariable-expansion-in-unroller
1853 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1854 Apply variable expansion when loops are unrolled
1857 Common Report RejectNegative Joined
1858 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1861 Common Alias(fstack-check=, specific, no)
1862 Insert stack checking code into the program. Same as -fstack-check=specific
1865 Common Var(common_deferred_options) Defer
1867 fstack-limit-register=
1868 Common RejectNegative Joined Var(common_deferred_options) Defer
1869 -fstack-limit-register=<register> Trap if the stack goes past <register>
1871 fstack-limit-symbol=
1872 Common RejectNegative Joined Var(common_deferred_options) Defer
1873 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1876 Common Report Var(flag_stack_protect, 1)
1877 Use propolice as a stack protection method
1879 fstack-protector-all
1880 Common Report RejectNegative Var(flag_stack_protect, 2)
1881 Use a stack protection method for every function
1884 Common RejectNegative Var(flag_stack_usage)
1885 Output stack usage information on a per-function basis
1889 Does nothing. Preserved for backward compatibility.
1891 ; Nonzero if we should do (language-dependent) alias analysis.
1892 ; Typically, this analysis will assume that expressions of certain
1893 ; types do not alias expressions of certain other types. Only used
1894 ; if alias analysis (in general) is enabled.
1896 Common Report Var(flag_strict_aliasing) Optimization
1897 Assume strict aliasing rules apply
1900 Common Report Var(flag_strict_overflow)
1901 Treat signed overflow as undefined
1904 Common Report Var(flag_sync_libcalls) Init(1)
1905 Implement __atomic operations via libcalls to legacy __sync functions
1908 Common Report Var(flag_syntax_only)
1909 Check for syntax errors, then stop
1912 Common Report Var(flag_test_coverage)
1913 Create data files needed by \"gcov\"
1916 Common Report Var(flag_thread_jumps) Optimization
1917 Perform jump threading optimizations
1920 Common Report Var(time_report)
1921 Report the time taken by each compiler pass
1924 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1925 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1928 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1931 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1934 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1937 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1940 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1943 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1944 Reorder top level functions, variables, and asms
1947 Common Report Var(flag_tracer)
1948 Perform superblock formation via tail duplication
1950 ; Zero means that floating-point math operations cannot generate a
1951 ; (user-visible) trap. This is the case, for example, in nonstop
1952 ; IEEE 754 arithmetic.
1954 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1955 Assume floating-point operations can trap
1958 Common Report Var(flag_trapv) Optimization
1959 Trap for signed overflow in addition, subtraction and multiplication
1962 Common Report Var(flag_tree_ccp) Optimization
1963 Enable SSA-CCP optimization on trees
1966 Common Report Var(flag_tree_bit_ccp) Optimization
1967 Enable SSA-BIT-CCP optimization on trees
1971 Does nothing. Preserved for backward compatibility.
1974 Common Report Var(flag_tree_ch) Optimization
1975 Enable loop header copying on trees
1977 ftree-coalesce-inlined-vars
1978 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
1979 Enable coalescing of copy-related user variables that are inlined
1982 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
1983 Enable coalescing of all copy-related user variables
1986 Common Report Var(flag_tree_copyrename) Optimization
1987 Replace SSA temporaries with better names in copies
1990 Common Report Var(flag_tree_copy_prop) Optimization
1991 Enable copy propagation on trees
1993 ftree-store-copy-prop
1995 Does nothing. Preserved for backward compatibility.
1998 Common Report Var(flag_tree_cselim) Init(2) Optimization
1999 Transform condition stores into unconditional ones
2001 ftree-switch-conversion
2002 Common Report Var(flag_tree_switch_conversion) Optimization
2003 Perform conversions of switch initializations.
2006 Common Report Var(flag_tree_dce) Optimization
2007 Enable SSA dead code elimination optimization on trees
2009 ftree-dominator-opts
2010 Common Report Var(flag_tree_dom) Optimization
2011 Enable dominator optimizations
2014 Common Report Var(flag_tree_tail_merge) Optimization
2015 Enable tail merging on trees
2018 Common Report Var(flag_tree_dse) Optimization
2019 Enable dead store elimination
2022 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2023 Enable forward propagation on trees
2026 Common Report Var(flag_tree_fre) Optimization
2027 Enable Full Redundancy Elimination (FRE) on trees
2030 Common Report Var(flag_optimize_strlen) Optimization
2031 Enable string length optimizations on trees
2033 ftree-loop-distribution
2034 Common Report Var(flag_tree_loop_distribution) Optimization
2035 Enable loop distribution on trees
2037 ftree-loop-distribute-patterns
2038 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2039 Enable loop distribution for patterns transformed into a library call
2042 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2043 Enable loop invariant motion on trees
2046 Common Alias(floop-interchange)
2047 Enable loop interchange transforms. Same as -floop-interchange
2050 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2051 Create canonical induction variables in loops
2054 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2055 Enable loop optimizations on tree level
2057 ftree-parallelize-loops=
2058 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2059 Enable automatic parallelization of loops
2062 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2063 Enable hoisting loads from conditional pointers.
2066 Common Report Var(flag_tree_pre) Optimization
2067 Enable SSA-PRE optimization on trees
2070 Common Report Var(flag_tree_partial_pre) Optimization
2071 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2074 Common Report Var(flag_tree_pta) Init(1) Optimization
2075 Perform function-local points-to analysis on trees.
2078 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2079 Enable reassociation on tree level
2083 Does nothing. Preserved for backward compatibility.
2086 Common Report Var(flag_tree_sink) Optimization
2087 Enable SSA code sinking on trees
2090 Common Report Var(flag_tree_slsr) Optimization
2091 Perform straight-line strength reduction
2094 Common Report Var(flag_tree_sra) Optimization
2095 Perform scalar replacement of aggregates
2098 Common Report Var(flag_tree_ter) Optimization
2099 Replace temporary expressions in the SSA->normal pass
2102 Common Report Var(flag_tree_live_range_split) Optimization
2103 Perform live range splitting during the SSA->normal pass
2106 Common Report Var(flag_tree_vrp) Init(0) Optimization
2107 Perform Value Range Propagation on trees
2110 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2111 Compile whole compilation unit at a time
2114 Common Report Var(flag_unroll_loops) Optimization
2115 Perform loop unrolling when iteration count is known
2118 Common Report Var(flag_unroll_all_loops) Optimization
2119 Perform loop unrolling for all loops
2121 ; Nonzero means that loop optimizer may assume that the induction variables
2122 ; that control loops do not overflow and that the loops with nontrivial
2123 ; exit condition are not infinite
2124 funsafe-loop-optimizations
2125 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2126 Allow loop optimizations to assume that the loops behave in normal way
2129 Common Report Var(flag_associative_math) SetByCombined
2130 Allow optimization for floating-point arithmetic which may change the
2131 result of the operation due to rounding.
2134 Common Report Var(flag_reciprocal_math) SetByCombined
2135 Same as -fassociative-math for expressions which include division.
2137 ; Nonzero means that unsafe floating-point math optimizations are allowed
2138 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2139 ; are allowed to assume that their arguments and results are "normal"
2140 ; (e.g., nonnegative for SQRT).
2141 funsafe-math-optimizations
2142 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2143 Allow math optimizations that may violate IEEE or ISO standards
2146 Common Report Var(flag_unswitch_loops) Optimization
2147 Perform loop unswitching
2150 Common Report Var(flag_unwind_tables) Optimization
2151 Just generate unwind tables for exception handling
2156 ; Positive if we should track variables, negative if we should run
2157 ; the var-tracking pass only to discard debug annotations, zero if
2158 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2159 ; will be set according to optimize, debug_info_level and debug_hooks
2160 ; in process_options ().
2162 Common Report Var(flag_var_tracking) Init(2) Optimization
2163 Perform variable tracking
2165 ; Positive if we should track variables at assignments, negative if
2166 ; we should run the var-tracking pass only to discard debug
2167 ; annotations. When flag_var_tracking_assignments ==
2168 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2169 fvar-tracking-assignments
2170 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2171 Perform variable tracking by annotating assignments
2173 ; Nonzero if we should toggle flag_var_tracking_assignments after
2174 ; processing options and computing its default. */
2175 fvar-tracking-assignments-toggle
2176 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2177 Toggle -fvar-tracking-assignments
2179 fvar-tracking-uninit
2180 Common Report Var(flag_var_tracking_uninit) Optimization
2181 Perform variable tracking and also tag variables that are uninitialized
2184 Common Report Var(flag_tree_vectorize) Optimization
2185 Enable loop vectorization on trees
2188 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2189 Enable basic block vectorization (SLP) on trees
2192 Common Report Var(flag_vect_cost_model) Optimization
2193 Enable use of cost model in vectorization
2195 ftree-vect-loop-version
2196 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2197 Enable loop versioning when doing loop vectorization on trees
2199 ftree-vectorizer-verbose=
2200 Common RejectNegative Joined UInteger
2201 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
2204 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2205 Enable copy propagation of scalar-evolution information.
2207 ; -fverbose-asm causes extra commentary information to be produced in
2208 ; the generated assembly code (to make it more readable). This option
2209 ; is generally only of use to those who actually need to read the
2210 ; generated assembly code (perhaps while debugging the compiler itself).
2211 ; -fno-verbose-asm, the default, causes the extra information
2212 ; to not be added and is useful when comparing two assembler files.
2214 Common Report Var(flag_verbose_asm)
2215 Add extra commentary to assembler output
2218 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2219 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2222 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2225 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2228 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2231 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2234 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2237 Common Report Var(flag_value_profile_transformations) Optimization
2238 Use expression value profiles in optimizations
2241 Common Report Var(flag_web) Init(2) Optimization
2242 Construct webs and split unrelated uses of single variable
2244 ftree-builtin-call-dce
2245 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2246 Enable conditional dead code elimination for builtin calls
2249 Common Report Var(flag_whole_program) Init(0) Optimization
2250 Perform whole program optimizations
2253 Common Report Var(flag_wrapv) Optimization
2254 Assume signed arithmetic overflow wraps around
2256 fzero-initialized-in-bss
2257 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2258 Put zero initialized data in the bss section
2261 Common JoinedOrMissing
2262 Generate debug information in default format
2265 Common JoinedOrMissing Negative(gdwarf-)
2266 Generate debug information in COFF format
2269 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2270 Generate debug information in DWARF v2 (or later) format
2273 Common JoinedOrMissing
2274 Generate debug information in default extended format
2277 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2278 Don't generate DWARF pubnames and pubtypes sections.
2281 Common RejectNegative Var(debug_generate_pub_sections, 1)
2282 Generate DWARF pubnames and pubtypes sections.
2284 gno-record-gcc-switches
2285 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2286 Don't record gcc command line switches in DWARF DW_AT_producer.
2288 grecord-gcc-switches
2289 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2290 Record gcc command line switches in DWARF DW_AT_producer.
2293 Common JoinedOrMissing Negative(gstabs+)
2294 Generate debug information in STABS format
2297 Common JoinedOrMissing Negative(gvms)
2298 Generate debug information in extended STABS format
2301 Common RejectNegative Var(dwarf_strict,0) Init(0)
2302 Emit DWARF additions beyond selected version
2305 Common Report RejectNegative Var(dwarf_strict,1)
2306 Don't emit DWARF additions beyond selected version
2309 Common Report Var(flag_gtoggle)
2310 Toggle debug information generation
2313 Common JoinedOrMissing Negative(gxcoff)
2314 Generate debug information in VMS format
2317 Common JoinedOrMissing Negative(gxcoff+)
2318 Generate debug information in XCOFF format
2321 Common JoinedOrMissing Negative(gcoff)
2322 Generate debug information in extended XCOFF format
2325 Driver Joined Separate
2328 Common Joined Var(plugindir_string) Init(0)
2329 -iplugindir=<dir> Set <dir> to be the default plugin directory
2332 Driver Joined Separate
2337 no-canonical-prefixes
2350 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2351 -o <file> Place output into <file>
2354 Common Var(profile_flag)
2355 Enable function profiling
2358 Driver Var(pass_exit_codes)
2361 Common Alias(Wpedantic)
2364 Common Var(flag_pedantic_errors)
2365 Like -pedantic but issue them as errors
2371 Driver Var(use_pipes)
2374 Driver JoinedOrMissing Var(print_file_name)
2376 print-libgcc-file-name
2379 print-multi-directory
2380 Driver Var(print_multi_directory)
2383 Driver Var(print_multi_lib)
2385 print-multi-os-directory
2386 Driver Var(print_multi_os_directory)
2389 Driver JoinedOrMissing Var(print_prog_name)
2392 Driver Var(print_search_dirs)
2395 Driver Var(print_sysroot)
2397 print-sysroot-headers-suffix
2398 Driver Var(print_sysroot_headers_suffix)
2401 Common Var(quiet_flag) RejectDriver
2402 Do not display functions compiled or elapsed time
2420 Driver Var(report_times)
2423 Driver JoinedOrMissing
2426 Driver Joined Separate
2430 ; C option, but driver must not handle as "-u ndef".
2433 Common Driver Var(verbose_flag)
2434 Enable verbose output
2437 Common Var(version_flag) RejectDriver
2438 Display the compiler's version
2441 Common Var(inhibit_warnings)
2445 Driver Separate Var(wrapper_string)
2448 Driver Joined Separate
2451 Driver RejectNegative Negative(pie)
2452 Create a shared library
2458 Driver Separate Alias(specs=)
2471 ; Documented for Fortran, but always accepted by driver.
2478 ; Documented for Go, but always accepted by driver.
2484 Driver RejectNegative Negative(shared)
2485 Create a position independent executable
2488 Driver Joined Separate
2490 ; This comment is to ensure we retain the blank line above.