1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 ; Free Software Foundation, Inc.
6 ; This file is part of GCC.
8 ; GCC is free software; you can redistribute it and/or modify it under
9 ; the terms of the GNU General Public License as published by the Free
10 ; Software Foundation; either version 3, or (at your option) any later
13 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 ; You should have received a copy of the GNU General Public License
19 ; along with GCC; see the file COPYING3. If not see
20 ; <http://www.gnu.org/licenses/>.
22 ; See the GCC internals manual (options.texi) for a description of this file's format.
24 ; Please try to keep this file in ASCII collating order.
38 ; Not used directly to control optimizations, only to save -Ofast
39 ; setting for "optimize" attributes.
43 ; True if this is the lto front end. This is used to disable gimple
44 ; generation and lowering passes that are normally run on the output
45 ; of a front end. These passes must be bypassed for lto since they
46 ; have already been done before the gimple was written.
50 ; 0 means straightforward implementation of complex divide acceptable.
51 ; 1 means wide ranges of inputs must work for complex divide.
52 ; 2 means C99-like requirements for complex multiply and divide.
54 int flag_complex_method = 1
56 ; Nonzero if subexpressions must be evaluated from left-to-right.
58 int flag_evaluation_order = 0
60 ; Language specific warning pass for unused results.
62 bool flag_warn_unused_result = false
67 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
71 ; True to warn about any objects definitions whose size is larger
72 ; than N bytes. Also want about function definitions whose returned
73 ; values are larger than N bytes, where N is 'larger_than_size'.
78 HOST_WIDE_INT larger_than_size
80 ; True to warn about any function whose frame size is larger
83 bool warn_frame_larger_than
86 HOST_WIDE_INT frame_larger_than_size
88 ; Nonzero means we should be saving declaration info into a .X file.
90 int flag_gen_aux_info = 0
92 ; Nonzero if we are compiling code for a shared library, zero for
97 ; These two are really VEC(char_p,heap) *.
100 void *flag_instrument_functions_exclude_functions
103 void *flag_instrument_functions_exclude_files
105 ; Generic structs (e.g. templates not explicitly specialized)
106 ; may not have a compilation unit associated with them, and so
107 ; may need to be treated differently from ordinary structs.
109 ; Structs only handled by reference (indirectly), will also usually
110 ; not need as much debugging information.
113 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
116 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
118 ; True if we should exit after parsing options.
120 bool exit_after_options
122 ; Type(s) of debugging information we are producing (if any). See
123 ; flag-types.h for the definitions of the different possible types of
124 ; debugging information.
126 enum debug_info_type write_symbols = NO_DEBUG
128 ; Level of debugging information we are producing. See flag-types.h
129 ; for the definitions of the different possible levels.
131 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
133 ; Nonzero means use GNU-only extensions in the generated symbolic
134 ; debugging information. Currently, this only has an effect when
135 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
137 bool use_gnu_debug_info_extensions
139 ; Original value of maximum field alignment in bytes, specified via
140 ; -fpack-struct=<value>.
142 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
144 ; Type of stack check.
146 enum stack_check_type flag_stack_check = NO_STACK_CHECK
148 ; True if stack usage information needs to be computed.
150 bool flag_stack_usage_info = false
152 ; -dA causes debug commentary information to be produced in
153 ; the generated assembly code (to make it more readable). This option
154 ; is generally only of use to those who actually need to read the
155 ; generated assembly code (perhaps while debugging the compiler itself).
156 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
157 ; to be a catchall for printing debug information in the assembler file.
161 ; -dP causes the rtl to be emitted as a comment in assembly.
163 int flag_dump_rtl_in_asm
165 ; Whether -da was passed (used only in handle_common_deferred_options).
167 bool flag_dump_all_passed
169 ; Other flags saying which kinds of debugging dump have been requested.
172 int rtl_dump_and_exit
175 int flag_print_asm_name
178 enum graph_dump_types graph_dump_format = no_graph
180 ; Name of top-level original source file (what was input to cpp).
181 ; This comes from the #-command at the beginning of the actual input.
182 ; If there isn't any there, then this is the cc1 input file name.
184 const char *main_input_filename
186 ; Pointer to base name in main_input_filename, with directories and a
187 ; single final extension removed, and the length of this base
191 const char *main_input_basename
194 int main_input_baselength
196 ; Which options have been printed by --help.
200 ; Which enums have been printed by --help. 0 = not printed, no
201 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
204 char *help_enum_printed
206 ; The number of columns for --help output.
208 unsigned int help_columns
210 ; Whether this options structure has been through finish_options
212 bool flag_opts_finished
224 Driver Alias(coverage)
230 Common Separate Alias(d)
233 Common Joined Alias(d)
236 Common Separate Alias(dumpbase)
239 Common Separate Alias(dumpdir)
242 Driver Separate Alias(e)
245 Driver Joined Alias(e)
248 Common Warning Alias(Wextra)
251 Driver Separate Alias(Xassembler)
254 Driver JoinedOrMissing Alias(Xassembler)
257 Driver Separate Alias(Xlinker)
260 Driver JoinedOrMissing Alias(Xlinker)
263 Driver Separate Alias(u)
266 Driver Joined Alias(u)
269 Common Driver Var(help_flag)
270 Display this information
273 Common Driver Report Joined
274 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
277 Driver Separate Alias(x)
280 Driver Joined Alias(x)
283 Driver Separate Alias(L)
286 Driver Joined Alias(L)
288 -no-canonical-prefixes
289 Driver Alias(no-canonical-prefixes)
291 -no-standard-libraries
292 Driver Alias(nostdlib)
295 Driver Var(no_sysroot_suffix)
304 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
307 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
310 Driver Alias(pass-exit-codes)
313 Common Alias(Wpedantic)
316 Common Alias(pedantic-errors)
325 Driver Separate Alias(B)
328 Driver JoinedOrMissing Alias(B)
334 Driver Separate Alias(print-file-name=)
337 Driver JoinedOrMissing Alias(print-file-name=)
339 -print-libgcc-file-name
340 Driver Alias(print-libgcc-file-name)
342 -print-multi-directory
343 Driver Alias(print-multi-directory)
346 Driver Alias(print-multi-lib)
348 -print-multi-os-directory
349 Driver Alias(print-multi-os-directory)
352 Driver 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
454 Optimize for debugging experience rather than speed or size
466 Driver Joined Separate
472 Driver Joined Separate
493 Common RejectNegative Warning Alias(Wextra)
494 This switch is deprecated; use -Wextra instead
497 Driver JoinedOrMissing
500 Driver JoinedOrMissing
503 Driver JoinedOrMissing
506 Common Var(warn_aggregate_return) Warning
507 Warn about returning structures, unions or arrays
510 Common Var(warn_array_bounds) Warning
511 Warn if an array is accessed out of bounds
514 Common Var(warn_attributes) Init(1) Warning
515 Warn about inappropriate attribute usage
518 Common Var(warn_cast_align) Warning
519 Warn about pointer casts which increase alignment
522 Common Var(warn_cpp) Init(1) Warning
523 Warn when a #warning directive is encountered
525 Wdeprecated-declarations
526 Common Var(warn_deprecated_decl) Init(1) Warning
527 Warn about uses of __attribute__((deprecated)) declarations
529 Wdisabled-optimization
530 Common Var(warn_disabled_optimization) Warning
531 Warn when an optimization pass is disabled
534 Common Var(warnings_are_errors)
535 Treat all warnings as errors
539 Treat specified warning as error
542 Common Var(extra_warnings) Warning
543 Print extra (possibly unwanted) warnings
546 Common Var(flag_fatal_errors)
547 Exit on the first error occurred
550 Common RejectNegative Joined UInteger
551 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
554 Common Var(warn_free_nonheap_object) Init(1) Warning
555 Warn when attempting to free a non-heap object
558 Common Var(warn_inline) Warning
559 Warn when an inlined function cannot be inlined
561 Winvalid-memory-model
562 Common Var(warn_invalid_memory_model) Init(1) Warning
563 Warn when an atomic memory model parameter is known to be outside the valid range.
566 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
569 Common RejectNegative Joined UInteger Warning
570 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
572 Wunsafe-loop-optimizations
573 Common Var(warn_unsafe_loop_optimizations) Warning
574 Warn if the loop cannot be optimized due to nontrivial assumptions.
577 Common Alias(Wsuggest-attribute=noreturn)
580 Common Var(warn_overflow) Init(1) Warning
581 Warn about overflow in arithmetic expressions
584 Common Var(warn_packed) Warning
585 Warn when the packed attribute has no effect on struct layout
588 Common Var(warn_padded) Warning
589 Warn when padding is required to align structure members
592 Common Var(pedantic) Warning
593 Issue warnings needed for strict compliance to the standard
596 Common Var(warn_shadow) Warning
597 Warn when one local variable shadows another
600 Common Var(warn_stack_protect) Warning
601 Warn when not issuing stack smashing protection for some reason
604 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
605 Warn if stack usage might be larger than specified amount
609 Warn about code which might break strict aliasing rules
612 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
613 Warn about code which might break strict aliasing rules
617 Warn about optimizations that assume that signed overflow is undefined
620 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
621 Warn about optimizations that assume that signed overflow is undefined
623 Wsuggest-attribute=const
624 Common Var(warn_suggest_attribute_const) Warning
625 Warn about functions which might be candidates for __attribute__((const))
627 Wsuggest-attribute=pure
628 Common Var(warn_suggest_attribute_pure) Warning
629 Warn about functions which might be candidates for __attribute__((pure))
631 Wsuggest-attribute=noreturn
632 Common Var(warn_suggest_attribute_noreturn) Warning
633 Warn about functions which might be candidates for __attribute__((noreturn))
636 Common Var(warn_switch) Warning
637 Warn about enumerated switches, with no default, missing a case
640 Common Var(warn_switch_default) Warning
641 Warn about enumerated switches missing a \"default:\" statement
644 Common Var(warn_switch_enum) Warning
645 Warn about all enumerated switches missing a specific case
648 Common Var(warn_system_headers) Warning
649 Do not suppress warnings from system headers
652 Common Var(warn_trampolines) Warning
653 Warn whenever a trampoline is generated
656 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
657 Warn if a comparison is always true or always false due to the limited range of the data type
660 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
661 Warn about uninitialized automatic variables
664 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
665 Warn about maybe uninitialized automatic variables
669 Does nothing. Preserved for backward compatibility.
672 Common Var(warn_unused) Init(0) Warning
673 Enable all -Wunused- warnings
675 Wunused-but-set-parameter
676 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
677 Warn when a function parameter is only set, otherwise unused
679 Wunused-but-set-variable
680 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
681 Warn when a variable is only set, otherwise unused
684 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
685 Warn when a function is unused
688 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
689 Warn when a label is unused
692 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
693 Warn when a function parameter is unused
696 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
697 Warn when an expression value is unused
700 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
701 Warn when a variable is unused
704 Common Var(warn_coverage_mismatch) Init(1) Warning
705 Warn in case profiles in -fprofile-use do not match
707 Wvector-operation-performance
708 Common Var(warn_vector_operation_performance) Warning
709 Warn when a vector operation is compiled outside the SIMD
724 Common Separate Var(aux_info_file_name)
725 -aux-info <file> Emit declaration information into <file>
728 Common Joined Alias(aux-info)
731 Common Separate RejectDriver Var(aux_base_name)
734 Common Separate RejectDriver
744 -d<letters> Enable dumps from specific passes of the compiler
747 Common Separate Var(dump_base_name)
748 -dumpbase <file> Set the file basename to be used for dumps
751 Common Separate Var(dump_dir_name)
752 -dumpdir <dir> Set the directory name to be used for dumps
764 Driver Joined Separate
766 ; This option has historically been passed down to the linker by an
767 ; accident of a %{e*} spec, so ensure it continues to be passed down
768 ; as a single option. The supported option for this purpose is
769 ; -rdynamic. See PR 47390.
773 ; The version of the C++ ABI in use. The following values are allowed:
775 ; 0: The version of the ABI believed most conformant with the C++ ABI
776 ; specification. This ABI may change as bugs are discovered and fixed.
777 ; Therefore, 0 will not necessarily indicate the same ABI in different
780 ; 1: The version of the ABI first used in G++ 3.2.
782 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
784 ; 3: The version of the ABI that fixes the missing underscore
785 ; in template non-type arguments of pointer type.
787 ; 4: The version of the ABI that introduces unambiguous mangling of
788 ; vector types. First selectable in G++ 4.5.
790 ; 5: The version of the ABI that ignores attribute const/noreturn
791 ; in function pointer mangling, and corrects mangling of decltype and
792 ; function parameters used in other parameters and the return type.
793 ; First selectable in G++ 4.6.
795 ; 6: The version of the ABI that doesn't promote scoped enums to int and
796 ; changes the mangling of template argument packs, const/static_cast,
797 ; prefix ++ and --, and a class scope function used as a template
799 ; First selectable in G++ 4.7.
801 ; 7: The version of the ABI that treats nullptr_t as a builtin type.
802 ; First selectable in G++ 4.8.
803 ; Additional positive integers will be assigned as new versions of
804 ; the ABI become the default version of the ABI.
806 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
809 Common Report Var(align_functions,0) Optimization UInteger
810 Align the start of functions
813 Common RejectNegative Joined UInteger Var(align_functions)
816 Common Report Var(align_jumps,0) Optimization UInteger
817 Align labels which are only reached by jumping
820 Common RejectNegative Joined UInteger Var(align_jumps)
823 Common Report Var(align_labels,0) Optimization UInteger
827 Common RejectNegative Joined UInteger Var(align_labels)
830 Common Report Var(align_loops,0) Optimization UInteger
831 Align the start of loops
834 Common RejectNegative Joined UInteger Var(align_loops)
838 Does nothing. Preserved for backward compatibility.
842 Does nothing. Preserved for backward compatibility.
844 fargument-noalias-global
846 Does nothing. Preserved for backward compatibility.
848 fargument-noalias-anything
850 Does nothing. Preserved for backward compatibility.
852 fasynchronous-unwind-tables
853 Common Report Var(flag_asynchronous_unwind_tables) Optimization
854 Generate unwind tables that are exact at each instruction boundary
857 Common Report Var(flag_auto_inc_dec) Init(1)
858 Generate auto-inc/dec instructions
860 ; -fcheck-bounds causes gcc to generate array bounds checks.
861 ; For C, C++ and ObjC: defaults off.
862 ; For Java: defaults to on.
863 ; For Fortran: defaults to off.
865 Common Report Var(flag_bounds_check)
866 Generate code to check bounds before indexing arrays
869 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
870 Replace add, compare, branch with branch on count register
872 fbranch-probabilities
873 Common Report Var(flag_branch_probabilities) Optimization
874 Use profiling information for branch probabilities
876 fbranch-target-load-optimize
877 Common Report Var(flag_branch_target_load_optimize) Optimization
878 Perform branch target load optimization before prologue / epilogue threading
880 fbranch-target-load-optimize2
881 Common Report Var(flag_branch_target_load_optimize2) Optimization
882 Perform branch target load optimization after prologue / epilogue threading
885 Common Report Var(flag_btr_bb_exclusive) Optimization
886 Restrict target load migration not to re-use registers in any basic block
889 Common Joined RejectNegative Var(common_deferred_options) Defer
890 -fcall-saved-<register> Mark <register> as being preserved across functions
893 Common Joined RejectNegative Var(common_deferred_options) Defer
894 -fcall-used-<register> Mark <register> as being corrupted by function calls
896 ; Nonzero for -fcaller-saves: allocate values in regs that need to
897 ; be saved across function calls, if that produces overall better code.
898 ; Optional now, so people can test it.
900 Common Report Var(flag_caller_saves) Optimization
901 Save registers around function calls
904 Common Report Var(flag_check_data_deps)
905 Compare the results of several data dependence analyzers.
907 fcombine-stack-adjustments
908 Common Report Var(flag_combine_stack_adjustments) Optimization
909 Looks for opportunities to reduce stack adjustments and stack references.
912 Common Report Var(flag_no_common,0) Optimization
913 Do not put uninitialized globals in the common section
917 ; Converted by the driver to -fcompare-debug= options.
920 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
921 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
923 fcompare-debug-second
924 Common Driver RejectNegative Var(flag_compare_debug)
925 Run only the second compilation of -fcompare-debug
928 Common Report Var(flag_compare_elim_after_reload) Optimization
929 Perform comparison elimination after register allocation has finished
932 Common Var(flag_conserve_stack) Optimization
933 Do not perform optimizations increasing noticeably stack usage
936 Common Report Var(flag_cprop_registers) Optimization
937 Perform a register copy-propagation optimization pass
940 Common Report Var(flag_crossjumping) Optimization
941 Perform cross-jumping optimization
944 Common Report Var(flag_cse_follow_jumps) Optimization
945 When running CSE, follow jumps to their targets
949 Does nothing. Preserved for backward compatibility.
952 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
953 Omit range reduction step when performing complex division
956 Common Report Var(flag_cx_fortran_rules) Optimization
957 Complex multiplication and division follow Fortran rules
960 Common Report Var(flag_data_sections) Optimization
961 Place data items into their own section
964 Common Report Var(common_deferred_options) Defer
965 List all available debugging counters with their limits and counts.
968 Common RejectNegative Joined Var(common_deferred_options) Defer
969 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
972 Common Joined RejectNegative Var(common_deferred_options) Defer
973 Map one directory name to another in debug information
976 Common Report Var(flag_debug_types_section) Init(0)
977 Output .debug_types section when using DWARF v4 debuginfo.
979 ; Nonzero for -fdefer-pop: don't pop args after each function call
980 ; instead save them up to pop many calls' args with one insns.
982 Common Report Var(flag_defer_pop) Optimization
983 Defer popping functions args from stack until later
986 Common Report Var(flag_delayed_branch) Optimization
987 Attempt to fill delay slots of branch instructions
989 fdelete-dead-exceptions
990 Common Report Var(flag_delete_dead_exceptions) Init(0)
991 Delete dead instructions that may throw exceptions
993 fdelete-null-pointer-checks
994 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
995 Delete useless null pointer checks
998 Common Report Var(flag_devirtualize) Optimization
999 Try to convert virtual calls to direct ones.
1001 fdiagnostics-show-location=
1002 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1003 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1005 ; Required for these enum values.
1010 Name(diagnostic_prefixing_rule) Type(int)
1013 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1016 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1018 fdiagnostics-show-caret
1019 Common Var(flag_diagnostics_show_caret) Init(1)
1020 Show the source line with a caret indicating the column
1022 fdiagnostics-show-option
1023 Common Var(flag_diagnostics_show_option) Init(1)
1024 Amend appropriate diagnostic messages with the command line option that controls them
1027 Common Joined RejectNegative Var(common_deferred_options) Defer
1028 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1031 Common Joined RejectNegative Var(common_deferred_options) Defer
1032 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1035 Common Joined RejectNegative Var(common_deferred_options) Defer
1036 -fdump-<type> Dump various compiler internals to a file
1039 Driver RejectNegative
1042 Common RejectNegative Joined Var(flag_dump_final_insns)
1043 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1046 Common RejectNegative Joined Var(flag_dump_go_spec)
1047 -fdump-go-spec=filename Write all declarations to file as Go code
1050 Common Report Var(flag_dump_noaddr)
1051 Suppress output of addresses in debugging dumps
1054 Common Var(flag_dump_passes) Init(0)
1055 Dump optimization passes
1058 Common Report Var(flag_dump_unnumbered)
1059 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1061 fdump-unnumbered-links
1062 Common Report Var(flag_dump_unnumbered_links)
1063 Suppress output of previous and next insn numbers in debugging dumps
1066 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1067 Enable CFI tables via GAS assembler directives.
1070 Common Report Var(flag_early_inlining) Init(1) Optimization
1071 Perform early inlining
1073 feliminate-dwarf2-dups
1074 Common Report Var(flag_eliminate_dwarf2_dups)
1075 Perform DWARF2 duplicate elimination
1078 Common Report Var(flag_ipa_sra) Init(0) Optimization
1079 Perform interprocedural reduction of aggregates
1081 feliminate-unused-debug-symbols
1082 Common Report Var(flag_debug_only_used_symbols)
1083 Perform unused type elimination in debug info
1085 feliminate-unused-debug-types
1086 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1087 Perform unused type elimination in debug info
1089 femit-class-debug-always
1090 Common Report Var(flag_emit_class_debug_always) Init(0)
1091 Do not suppress C++ class debug information.
1094 Common Report Var(flag_exceptions) Optimization
1095 Enable exception handling
1097 fexpensive-optimizations
1098 Common Report Var(flag_expensive_optimizations) Optimization
1099 Perform a number of minor, expensive optimizations
1102 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1103 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1106 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1109 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1112 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1118 Common Var(flag_fat_lto_objects) Init(1)
1119 Output lto objects containing both the intermediate language and binary output.
1122 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1123 Assume no NaNs or infinities are generated
1126 Common Joined RejectNegative Var(common_deferred_options) Defer
1127 -ffixed-<register> Mark <register> as being unavailable to the compiler
1130 Common Report Var(flag_float_store) Optimization
1131 Don't allocate floats and doubles in extended-precision registers
1135 Does nothing. Preserved for backward compatibility.
1138 Common Report Var(flag_forward_propagate) Optimization
1139 Perform a forward propagation pass on RTL
1142 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1143 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1146 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1149 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1151 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1153 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1156 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1158 ; Nonzero means don't put addresses of constant functions in registers.
1159 ; Used for compiling the Unix kernel, where strange substitutions are
1160 ; done on the assembly output.
1162 Common Report Var(flag_no_function_cse,0)
1163 Allow function addresses to be held in registers
1166 Common Report Var(flag_function_sections)
1167 Place each function into its own section
1170 Common Report Var(flag_gcse) Optimization
1171 Perform global common subexpression elimination
1174 Common Report Var(flag_gcse_lm) Init(1) Optimization
1175 Perform enhanced load motion during global common subexpression elimination
1178 Common Report Var(flag_gcse_sm) Init(0) Optimization
1179 Perform store motion after global common subexpression elimination
1182 Common Report Var(flag_gcse_las) Init(0) Optimization
1183 Perform redundant load after store elimination in global common subexpression
1187 Common Report Var(flag_gcse_after_reload) Optimization
1188 Perform global common subexpression elimination after register allocation
1191 ; This option is not documented yet as its semantics will change.
1193 Common Report Var(flag_graphite)
1194 Enable in and out of Graphite representation
1197 Common Report Var(flag_graphite_identity) Optimization
1198 Enable Graphite Identity transformation
1200 fhoist-adjacent-loads
1201 Common Report Var(flag_hoist_adjacent_loads) Optimization
1202 Enable hoisting adjacent loads to encourage generating conditional move
1205 floop-parallelize-all
1206 Common Report Var(flag_loop_parallelize_all) Optimization
1207 Mark all loops as parallel
1210 Common Report Var(flag_loop_strip_mine) Optimization
1211 Enable Loop Strip Mining transformation
1214 Common Report Var(flag_loop_interchange) Optimization
1215 Enable Loop Interchange transformation
1218 Common Report Var(flag_loop_block) Optimization
1219 Enable Loop Blocking transformation
1222 Common Report Var(flag_tm)
1223 Enable support for GNU transactional memory
1227 Does nothing. Preserved for backward compatibility.
1230 Common Report Var(flag_loop_optimize_isl) Optimization
1231 Enable the ISL based loop nest optimizer
1233 fstrict-volatile-bitfields
1234 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1235 Force bitfield accesses to match their type width
1237 fguess-branch-probability
1238 Common Report Var(flag_guess_branch_prob) Optimization
1239 Enable guessing of branch probabilities
1241 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1242 ; Generate position-independent code for executables if possible
1243 ; On SVR4 targets, it also controls whether or not to emit a
1244 ; string identifying the compiler.
1246 Common Report Var(flag_no_ident,0)
1247 Process #ident directives
1250 Common Report Var(flag_if_conversion) Optimization
1251 Perform conversion of conditional jumps to branchless equivalents
1254 Common Report Var(flag_if_conversion2) Optimization
1255 Perform conversion of conditional jumps to conditional execution
1258 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1259 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1262 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1265 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1268 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1271 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1273 ftree-loop-if-convert
1274 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1275 Convert conditional jumps in innermost loops to branchless equivalents
1277 ftree-loop-if-convert-stores
1278 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1279 Also if-convert conditional jumps containing memory writes
1281 ; -finhibit-size-directive inhibits output of .size for ELF.
1282 ; This is used only for compiling crtstuff.c,
1283 ; and it may be extended to other effects
1284 ; needed for crtstuff.c on other systems.
1285 finhibit-size-directive
1286 Common Report Var(flag_inhibit_size_directive)
1287 Do not generate .size directives
1290 Common Report Var(flag_indirect_inlining)
1291 Perform indirect inlining
1293 ; General flag to enable inlining. Specifying -fno-inline will disable
1294 ; all inlining apart from always-inline functions.
1296 Common Report Var(flag_no_inline,0) Init(0) Optimization
1297 Enable inlining of function declared \"inline\", disabling disables all inlining
1299 finline-small-functions
1300 Common Report Var(flag_inline_small_functions) Optimization
1301 Integrate functions into their callers when code size is known not to grow
1304 Common Report Var(flag_inline_functions) Optimization
1305 Integrate functions not declared \"inline\" into their callers when profitable
1307 finline-functions-called-once
1308 Common Report Var(flag_inline_functions_called_once) Optimization
1309 Integrate functions only required by their single caller
1312 Common RejectNegative Joined Alias(finline-limit=)
1315 Common RejectNegative Joined UInteger
1316 -finline-limit=<number> Limit the size of inlined functions to <number>
1319 Common Report Var(flag_inline_atomics) Init(1) Optimization
1320 Inline __atomic operations when a lock free instruction sequence is available.
1322 finstrument-functions
1323 Common Report Var(flag_instrument_function_entry_exit)
1324 Instrument function entry and exit with profiling calls
1326 finstrument-functions-exclude-function-list=
1327 Common RejectNegative Joined
1328 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1330 finstrument-functions-exclude-file-list=
1331 Common RejectNegative Joined
1332 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1335 Common Report Var(flag_ipa_cp) Optimization
1336 Perform Interprocedural constant propagation
1339 Common Report Var(flag_ipa_cp_clone) Optimization
1340 Perform cloning to make Interprocedural constant propagation stronger
1343 Common Report Var(flag_ipa_profile) Init(0) Optimization
1344 Perform interprocedural profile propagation
1347 Common Report Var(flag_ipa_pta) Init(0) Optimization
1348 Perform interprocedural points-to analysis
1351 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1352 Discover pure and const functions
1355 Common Report Var(flag_ipa_reference) Init(0) Optimization
1356 Discover readonly and non addressable static variables
1360 Does nothing. Preserved for backward compatibility.
1364 Does nothing. Preserved for backward compatibility.
1367 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1368 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1371 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1374 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1377 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1380 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1381 -fira-region=[one|all|mixed] Set regions for IRA
1384 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1387 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1390 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1393 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1396 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1397 Use IRA based register pressure calculation
1398 in RTL hoist optimizations.
1401 Common Report Var(flag_ira_loop_pressure)
1402 Use IRA based register pressure calculation
1403 in RTL loop optimizations.
1405 fira-share-save-slots
1406 Common Report Var(flag_ira_share_save_slots) Init(1)
1407 Share slots for saving different hard registers.
1409 fira-share-spill-slots
1410 Common Report Var(flag_ira_share_spill_slots) Init(1)
1411 Share stack slots for spilled pseudo-registers.
1414 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1415 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1418 Common Report Var(flag_ivopts) Init(1) Optimization
1419 Optimize induction variables on trees
1422 Common Var(flag_jump_tables) Init(1) Optimization
1423 Use jump tables for sufficiently large switch statements
1425 fkeep-inline-functions
1426 Common Report Var(flag_keep_inline_functions)
1427 Generate code for functions even if they are fully inlined
1430 Common Report Var(flag_keep_static_consts) Init(1)
1431 Emit static const variables even if they are not used
1434 Common Report Var(flag_leading_underscore) Init(-1)
1435 Give external symbols a leading underscore
1439 Does nothing. Preserved for backward compatibility.
1443 Enable link-time optimization.
1446 Common RejectNegative Joined Var(flag_lto)
1447 Link-time optimization with number of parallel jobs or jobserver.
1450 Common Var(flag_lto_partition_1to1)
1451 Partition symbols and vars at linktime based on object files they originate from
1453 flto-partition=balanced
1454 Common Var(flag_lto_partition_balanced)
1455 Partition functions and vars at linktime into approximately same sized buckets
1458 Common Var(flag_lto_partition_max)
1459 Put every symbol into separate partition
1462 Common Var(flag_lto_partition_none)
1463 Disable partioning and streaming
1465 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1466 flto-compression-level=
1467 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1468 -flto-compression-level=<number> Use zlib compression level <number> for IL
1471 Common Report Var(flag_lto_report) Init(0)
1472 Report various link-time optimization statistics
1475 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1476 Set errno after built-in math functions
1479 Common Joined RejectNegative UInteger Var(flag_max_errors)
1480 -fmax-errors=<number> Maximum number of errors to report
1483 Common Report Var(mem_report)
1484 Report on permanent memory allocation
1487 Common Report Var(mem_report_wpa)
1488 Report on permanent memory allocation in WPA only
1490 ; This will attempt to merge constant section constants, if 1 only
1491 ; string constants and constants from constant pool, if 2 also constant
1493 fmerge-all-constants
1494 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1495 Attempt to merge identical constants and constant variables
1498 Common Report Var(flag_merge_constants,1) Optimization
1499 Attempt to merge identical constants across compilation units
1501 fmerge-debug-strings
1502 Common Report Var(flag_merge_debug_strings) Init(1)
1503 Attempt to merge identical debug strings across compilation units
1506 Common RejectNegative Joined UInteger
1507 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1510 Common Report Var(flag_modulo_sched) Optimization
1511 Perform SMS based modulo scheduling before the first scheduling pass
1513 fmodulo-sched-allow-regmoves
1514 Common Report Var(flag_modulo_sched_allow_regmoves)
1515 Perform SMS based modulo scheduling with register moves allowed
1517 fmove-loop-invariants
1518 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1519 Move loop invariant computations out of loops
1522 Common Var(flag_dce) Init(1) Optimization
1523 Use the RTL dead code elimination pass
1526 Common Var(flag_dse) Init(1) Optimization
1527 Use the RTL dead store elimination pass
1529 freschedule-modulo-scheduled-loops
1530 Common Report Var(flag_resched_modulo_sched) Optimization
1531 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1533 fnon-call-exceptions
1534 Common Report Var(flag_non_call_exceptions) Optimization
1535 Support synchronous non-call exceptions
1538 Common Report Var(flag_omit_frame_pointer) Optimization
1539 When possible do not generate stack frames
1542 Common Report Var(flag_opt_info) Optimization
1543 Enable all optimization info dumps on stderr
1546 Common Joined RejectNegative Var(common_deferred_options) Defer
1547 -fopt-info[-<type>=filename] Dump compiler optimization details
1549 foptimize-register-move
1550 Common Report Var(flag_regmove) Optimization
1551 Do the full register move optimization pass
1553 foptimize-sibling-calls
1554 Common Report Var(flag_optimize_sibling_calls) Optimization
1555 Optimize sibling and tail recursive calls
1558 Common Report Var(flag_partial_inlining)
1559 Perform partial inlining
1562 Common Report Var(pre_ipa_mem_report)
1563 Report on memory allocation before interprocedural optimization
1565 fpost-ipa-mem-report
1566 Common Report Var(post_ipa_mem_report)
1567 Report on memory allocation before interprocedural optimization
1570 Common Report Var(flag_pack_struct) Optimization
1571 Pack structure members together without holes
1574 Common RejectNegative Joined UInteger Optimization
1575 -fpack-struct=<number> Set initial maximum structure member alignment
1578 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1579 Return small aggregates in memory, not registers
1582 Common Report Var(flag_peel_loops) Optimization
1583 Perform loop peeling
1586 Common Report Var(flag_no_peephole,0) Optimization
1587 Enable machine specific peephole optimizations
1590 Common Report Var(flag_peephole2) Optimization
1591 Enable an RTL peephole pass before sched2
1594 Common Report Var(flag_pic,2)
1595 Generate position-independent code if possible (large mode)
1598 Common Report Var(flag_pie,2)
1599 Generate position-independent code for executables if possible (large mode)
1602 Common Report Var(flag_pic,1)
1603 Generate position-independent code if possible (small mode)
1606 Common Report Var(flag_pie,1)
1607 Generate position-independent code for executables if possible (small mode)
1610 Common Joined RejectNegative Var(common_deferred_options) Defer
1611 Specify a plugin to load
1614 Common Joined RejectNegative Var(common_deferred_options) Defer
1615 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1617 fpredictive-commoning
1618 Common Report Var(flag_predictive_commoning) Optimization
1619 Run predictive commoning optimization.
1621 fprefetch-loop-arrays
1622 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1623 Generate prefetch instructions, if available, for arrays in loops
1626 Common Report Var(profile_flag)
1627 Enable basic program profiling code
1630 Common Report Var(profile_arc_flag)
1631 Insert arc-based program profiling code
1634 Common Joined RejectNegative Var(profile_data_prefix)
1635 Set the top-level directory for storing the profile data.
1636 The default is 'pwd'.
1639 Common Report Var(flag_profile_correction)
1640 Enable correction of flow inconsistent profile data input
1644 Enable common options for generating profile info for profile feedback directed optimizations
1647 Common Joined RejectNegative
1648 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1651 Common Var(flag_profile_use)
1652 Enable common options for performing profile feedback directed optimizations
1655 Common Joined RejectNegative
1656 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1659 Common Report Var(flag_profile_values)
1660 Insert code to profile values of expressions
1663 Common Report Var(profile_report)
1664 Report on consistency of profile
1667 Common Var(common_deferred_options) Defer
1670 Common Joined RejectNegative Var(common_deferred_options) Defer
1671 -frandom-seed=<string> Make compile reproducible using <string>
1673 ; This switch causes the command line that was used to create an
1674 ; object file to be recorded into the object file. The exact format
1675 ; of this recording is target and binary file format dependent.
1676 ; It is related to the -fverbose-asm switch, but that switch only
1677 ; records information in the assembler output file as comments, so
1678 ; they never reach the object file.
1679 frecord-gcc-switches
1680 Common Report Var(flag_record_gcc_switches)
1681 Record gcc command line switches in the object file.
1684 Common Report Var(flag_pcc_struct_return,0) Optimization
1685 Return small aggregates in registers
1688 Common Report Var(flag_regmove) Optimization
1689 Enables a register move optimization
1692 Common Report Var(flag_rename_registers) Init(2) Optimization
1693 Perform a register renaming optimization pass
1696 Common Report Var(flag_reorder_blocks) Optimization
1697 Reorder basic blocks to improve code placement
1699 freorder-blocks-and-partition
1700 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1701 Reorder basic blocks and partition into hot and cold sections
1704 Common Report Var(flag_reorder_functions) Optimization
1705 Reorder functions to improve code placement
1707 frerun-cse-after-loop
1708 Common Report Var(flag_rerun_cse_after_loop) Optimization
1709 Add a common subexpression elimination pass after loop optimizations
1713 Does nothing. Preserved for backward compatibility.
1716 Common Report Var(flag_rounding_math) Optimization SetByCombined
1717 Disable optimizations that assume default FP rounding behavior
1720 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1721 Enable scheduling across basic blocks
1724 Common Report Var(flag_sched_pressure) Init(0) Optimization
1725 Enable register pressure sensitive insn scheduling
1728 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1729 Allow speculative motion of non-loads
1732 Common Report Var(flag_schedule_speculative_load) Optimization
1733 Allow speculative motion of some loads
1735 fsched-spec-load-dangerous
1736 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1737 Allow speculative motion of more loads
1740 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1741 -fsched-verbose=<number> Set the verbosity level of the scheduler
1743 fsched2-use-superblocks
1744 Common Report Var(flag_sched2_use_superblocks) Optimization
1745 If scheduling post reload, do superblock scheduling
1749 Does nothing. Preserved for backward compatibility.
1752 Common Report Var(flag_schedule_insns) Optimization
1753 Reschedule instructions before register allocation
1756 Common Report Var(flag_schedule_insns_after_reload) Optimization
1757 Reschedule instructions after register allocation
1759 ; This flag should be on when a target implements non-trivial
1760 ; scheduling hooks, maybe saving some information for its own sake.
1761 ; On IA64, for example, this is used for correct bundling.
1762 fselective-scheduling
1763 Common Report Var(flag_selective_scheduling) Optimization
1764 Schedule instructions using selective scheduling algorithm
1766 fselective-scheduling2
1767 Common Report Var(flag_selective_scheduling2) Optimization
1768 Run selective scheduling after reload
1770 fsel-sched-pipelining
1771 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1772 Perform software pipelining of inner loops during selective scheduling
1774 fsel-sched-pipelining-outer-loops
1775 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1776 Perform software pipelining of outer loops during selective scheduling
1778 fsel-sched-reschedule-pipelined
1779 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1780 Reschedule pipelined regions without pipelining
1782 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1783 ; of stalled insns into the ready list.
1784 fsched-stalled-insns
1785 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1786 Allow premature scheduling of queued insns
1788 fsched-stalled-insns=
1789 Common RejectNegative Joined UInteger
1790 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1792 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1793 ; be examined for a dependency on a stalled insn that is candidate for
1794 ; premature removal from the queue of stalled insns into the ready list (has
1795 ; an effect only if the flag 'sched_stalled_insns' is set).
1796 fsched-stalled-insns-dep
1797 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1798 Set dependence distance checking in premature scheduling of queued insns
1800 fsched-stalled-insns-dep=
1801 Common RejectNegative Joined UInteger
1802 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1804 fsched-group-heuristic
1805 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1806 Enable the group heuristic in the scheduler
1808 fsched-critical-path-heuristic
1809 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1810 Enable the critical path heuristic in the scheduler
1812 fsched-spec-insn-heuristic
1813 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1814 Enable the speculative instruction heuristic in the scheduler
1816 fsched-rank-heuristic
1817 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1818 Enable the rank heuristic in the scheduler
1820 fsched-last-insn-heuristic
1821 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1822 Enable the last instruction heuristic in the scheduler
1824 fsched-dep-count-heuristic
1825 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1826 Enable the dependent count heuristic in the scheduler
1829 Common Report Var(flag_section_anchors) Optimization
1830 Access data in the same section from shared anchor points
1834 Does nothing. Preserved for backward compatibility.
1838 Does nothing. Preserved for backward compatibility.
1841 Common Report Var(flag_ree) Init(0)
1842 Turn on Redundant Extensions Elimination pass.
1845 Common Report Var(flag_show_column) Init(1)
1846 Show column numbers in diagnostics, when available. Default on
1849 Common Report Var(flag_shrink_wrap) Optimization
1850 Emit function prologues only before parts of the function that need it,
1851 rather than at the top of the function.
1854 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1855 Disable optimizations observable by IEEE signaling NaNs
1858 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1859 Disable floating point optimizations that ignore the IEEE signedness of zero
1861 fsingle-precision-constant
1862 Common Report Var(flag_single_precision_constant) Optimization
1863 Convert floating point constants to single precision constants
1865 fsplit-ivs-in-unroller
1866 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1867 Split lifetimes of induction variables when loops are unrolled
1870 Common Report Var(flag_split_stack) Init(-1)
1871 Generate discontiguous stack frames
1874 Common Report Var(flag_split_wide_types) Optimization
1875 Split wide types into independent registers
1877 fvariable-expansion-in-unroller
1878 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1879 Apply variable expansion when loops are unrolled
1882 Common Report RejectNegative Joined
1883 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1886 Common Alias(fstack-check=, specific, no)
1887 Insert stack checking code into the program. Same as -fstack-check=specific
1890 Common Var(common_deferred_options) Defer
1892 fstack-limit-register=
1893 Common RejectNegative Joined Var(common_deferred_options) Defer
1894 -fstack-limit-register=<register> Trap if the stack goes past <register>
1896 fstack-limit-symbol=
1897 Common RejectNegative Joined Var(common_deferred_options) Defer
1898 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1901 Common Report Var(flag_stack_protect, 1)
1902 Use propolice as a stack protection method
1904 fstack-protector-all
1905 Common Report RejectNegative Var(flag_stack_protect, 2)
1906 Use a stack protection method for every function
1909 Common RejectNegative Var(flag_stack_usage)
1910 Output stack usage information on a per-function basis
1914 Does nothing. Preserved for backward compatibility.
1916 ; Nonzero if we should do (language-dependent) alias analysis.
1917 ; Typically, this analysis will assume that expressions of certain
1918 ; types do not alias expressions of certain other types. Only used
1919 ; if alias analysis (in general) is enabled.
1921 Common Report Var(flag_strict_aliasing) Optimization
1922 Assume strict aliasing rules apply
1925 Common Report Var(flag_strict_overflow)
1926 Treat signed overflow as undefined
1929 Common Report Var(flag_sync_libcalls) Init(1)
1930 Implement __atomic operations via libcalls to legacy __sync functions
1933 Common Report Var(flag_syntax_only)
1934 Check for syntax errors, then stop
1937 Common Report Var(flag_test_coverage)
1938 Create data files needed by \"gcov\"
1941 Common Report Var(flag_thread_jumps) Optimization
1942 Perform jump threading optimizations
1945 Common Report Var(time_report)
1946 Report the time taken by each compiler pass
1949 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
1950 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1953 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
1956 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
1959 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
1962 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
1965 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
1968 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1969 Reorder top level functions, variables, and asms
1972 Common Report Var(flag_tracer)
1973 Perform superblock formation via tail duplication
1975 ; Zero means that floating-point math operations cannot generate a
1976 ; (user-visible) trap. This is the case, for example, in nonstop
1977 ; IEEE 754 arithmetic.
1979 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
1980 Assume floating-point operations can trap
1983 Common Report Var(flag_trapv) Optimization
1984 Trap for signed overflow in addition, subtraction and multiplication
1987 Common Report Var(flag_tree_ccp) Optimization
1988 Enable SSA-CCP optimization on trees
1991 Common Report Var(flag_tree_bit_ccp) Optimization
1992 Enable SSA-BIT-CCP optimization on trees
1996 Does nothing. Preserved for backward compatibility.
1999 Common Report Var(flag_tree_ch) Optimization
2000 Enable loop header copying on trees
2002 ftree-coalesce-inlined-vars
2003 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2004 Enable coalescing of copy-related user variables that are inlined
2007 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2008 Enable coalescing of all copy-related user variables
2011 Common Report Var(flag_tree_copyrename) Optimization
2012 Replace SSA temporaries with better names in copies
2015 Common Report Var(flag_tree_copy_prop) Optimization
2016 Enable copy propagation on trees
2018 ftree-store-copy-prop
2020 Does nothing. Preserved for backward compatibility.
2023 Common Report Var(flag_tree_cselim) Init(2) Optimization
2024 Transform condition stores into unconditional ones
2026 ftree-switch-conversion
2027 Common Report Var(flag_tree_switch_conversion) Optimization
2028 Perform conversions of switch initializations.
2031 Common Report Var(flag_tree_dce) Optimization
2032 Enable SSA dead code elimination optimization on trees
2034 ftree-dominator-opts
2035 Common Report Var(flag_tree_dom) Optimization
2036 Enable dominator optimizations
2039 Common Report Var(flag_tree_tail_merge) Optimization
2040 Enable tail merging on trees
2043 Common Report Var(flag_tree_dse) Optimization
2044 Enable dead store elimination
2047 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2048 Enable forward propagation on trees
2051 Common Report Var(flag_tree_fre) Optimization
2052 Enable Full Redundancy Elimination (FRE) on trees
2055 Common Report Var(flag_optimize_strlen) Optimization
2056 Enable string length optimizations on trees
2058 ftree-loop-distribution
2059 Common Report Var(flag_tree_loop_distribution) Optimization
2060 Enable loop distribution on trees
2062 ftree-loop-distribute-patterns
2063 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2064 Enable loop distribution for patterns transformed into a library call
2067 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2068 Enable loop invariant motion on trees
2071 Common Alias(floop-interchange)
2072 Enable loop interchange transforms. Same as -floop-interchange
2075 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2076 Create canonical induction variables in loops
2079 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2080 Enable loop optimizations on tree level
2082 ftree-parallelize-loops=
2083 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2084 Enable automatic parallelization of loops
2087 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2088 Enable hoisting loads from conditional pointers.
2091 Common Report Var(flag_tree_pre) Optimization
2092 Enable SSA-PRE optimization on trees
2095 Common Report Var(flag_tree_partial_pre) Optimization
2096 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2099 Common Report Var(flag_tree_pta) Init(1) Optimization
2100 Perform function-local points-to analysis on trees.
2103 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2104 Enable reassociation on tree level
2108 Does nothing. Preserved for backward compatibility.
2111 Common Report Var(flag_tree_sink) Optimization
2112 Enable SSA code sinking on trees
2115 Common Report Var(flag_tree_slsr) Optimization
2116 Perform straight-line strength reduction
2119 Common Report Var(flag_tree_sra) Optimization
2120 Perform scalar replacement of aggregates
2123 Common Report Var(flag_tree_ter) Optimization
2124 Replace temporary expressions in the SSA->normal pass
2127 Common Report Var(flag_tree_live_range_split) Optimization
2128 Perform live range splitting during the SSA->normal pass
2131 Common Report Var(flag_tree_vrp) Init(0) Optimization
2132 Perform Value Range Propagation on trees
2135 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2136 Compile whole compilation unit at a time
2139 Common Report Var(flag_unroll_loops) Optimization
2140 Perform loop unrolling when iteration count is known
2143 Common Report Var(flag_unroll_all_loops) Optimization
2144 Perform loop unrolling for all loops
2146 ; Nonzero means that loop optimizer may assume that the induction variables
2147 ; that control loops do not overflow and that the loops with nontrivial
2148 ; exit condition are not infinite
2149 funsafe-loop-optimizations
2150 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2151 Allow loop optimizations to assume that the loops behave in normal way
2154 Common Report Var(flag_associative_math) SetByCombined
2155 Allow optimization for floating-point arithmetic which may change the
2156 result of the operation due to rounding.
2159 Common Report Var(flag_reciprocal_math) SetByCombined
2160 Same as -fassociative-math for expressions which include division.
2162 ; Nonzero means that unsafe floating-point math optimizations are allowed
2163 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2164 ; are allowed to assume that their arguments and results are "normal"
2165 ; (e.g., nonnegative for SQRT).
2166 funsafe-math-optimizations
2167 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2168 Allow math optimizations that may violate IEEE or ISO standards
2171 Common Report Var(flag_unswitch_loops) Optimization
2172 Perform loop unswitching
2175 Common Report Var(flag_unwind_tables) Optimization
2176 Just generate unwind tables for exception handling
2181 ; Positive if we should track variables, negative if we should run
2182 ; the var-tracking pass only to discard debug annotations, zero if
2183 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2184 ; will be set according to optimize, debug_info_level and debug_hooks
2185 ; in process_options ().
2187 Common Report Var(flag_var_tracking) Init(2) Optimization
2188 Perform variable tracking
2190 ; Positive if we should track variables at assignments, negative if
2191 ; we should run the var-tracking pass only to discard debug
2192 ; annotations. When flag_var_tracking_assignments ==
2193 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2194 fvar-tracking-assignments
2195 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2196 Perform variable tracking by annotating assignments
2198 ; Nonzero if we should toggle flag_var_tracking_assignments after
2199 ; processing options and computing its default. */
2200 fvar-tracking-assignments-toggle
2201 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2202 Toggle -fvar-tracking-assignments
2204 fvar-tracking-uninit
2205 Common Report Var(flag_var_tracking_uninit) Optimization
2206 Perform variable tracking and also tag variables that are uninitialized
2209 Common Report Var(flag_tree_vectorize) Optimization
2210 Enable loop vectorization on trees
2212 ftree-vectorizer-verbose=
2213 Common RejectNegative Joined UInteger Var(common_deferred_options) Defer
2214 -ftree-vectorizer-verbose=<number> This switch is deprecated. Use -fopt-info instead.
2217 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2218 Enable basic block vectorization (SLP) on trees
2221 Common Report Var(flag_vect_cost_model) Optimization
2222 Enable use of cost model in vectorization
2224 ftree-vect-loop-version
2225 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2226 Enable loop versioning when doing loop vectorization on trees
2229 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2230 Enable copy propagation of scalar-evolution information.
2232 ; -fverbose-asm causes extra commentary information to be produced in
2233 ; the generated assembly code (to make it more readable). This option
2234 ; is generally only of use to those who actually need to read the
2235 ; generated assembly code (perhaps while debugging the compiler itself).
2236 ; -fno-verbose-asm, the default, causes the extra information
2237 ; to not be added and is useful when comparing two assembler files.
2239 Common Report Var(flag_verbose_asm)
2240 Add extra commentary to assembler output
2243 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2244 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2247 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2250 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2253 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2256 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2259 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2262 Common Report Var(flag_value_profile_transformations) Optimization
2263 Use expression value profiles in optimizations
2266 Common Report Var(flag_web) Init(2) Optimization
2267 Construct webs and split unrelated uses of single variable
2269 ftree-builtin-call-dce
2270 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2271 Enable conditional dead code elimination for builtin calls
2274 Common Report Var(flag_whole_program) Init(0) Optimization
2275 Perform whole program optimizations
2278 Common Report Var(flag_wrapv) Optimization
2279 Assume signed arithmetic overflow wraps around
2281 fzero-initialized-in-bss
2282 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2283 Put zero initialized data in the bss section
2286 Common JoinedOrMissing
2287 Generate debug information in default format
2290 Common JoinedOrMissing Negative(gdwarf-)
2291 Generate debug information in COFF format
2294 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2295 Generate debug information in DWARF v2 (or later) format
2298 Common JoinedOrMissing
2299 Generate debug information in default extended format
2302 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2303 Don't generate DWARF pubnames and pubtypes sections.
2306 Common RejectNegative Var(debug_generate_pub_sections, 1)
2307 Generate DWARF pubnames and pubtypes sections.
2309 gno-record-gcc-switches
2310 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2311 Don't record gcc command line switches in DWARF DW_AT_producer.
2313 grecord-gcc-switches
2314 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2315 Record gcc command line switches in DWARF DW_AT_producer.
2318 Common JoinedOrMissing Negative(gstabs+)
2319 Generate debug information in STABS format
2322 Common JoinedOrMissing Negative(gvms)
2323 Generate debug information in extended STABS format
2326 Common RejectNegative Var(dwarf_strict,0) Init(0)
2327 Emit DWARF additions beyond selected version
2330 Common Report RejectNegative Var(dwarf_strict,1)
2331 Don't emit DWARF additions beyond selected version
2334 Common Report Var(flag_gtoggle)
2335 Toggle debug information generation
2338 Common JoinedOrMissing Negative(gxcoff)
2339 Generate debug information in VMS format
2342 Common JoinedOrMissing Negative(gxcoff+)
2343 Generate debug information in XCOFF format
2346 Common JoinedOrMissing Negative(gcoff)
2347 Generate debug information in extended XCOFF format
2350 Driver Joined Separate
2353 Common Joined Var(plugindir_string) Init(0)
2354 -iplugindir=<dir> Set <dir> to be the default plugin directory
2357 Driver Joined Separate
2362 no-canonical-prefixes
2375 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2376 -o <file> Place output into <file>
2379 Common Var(profile_flag)
2380 Enable function profiling
2383 Driver Var(pass_exit_codes)
2386 Common Alias(Wpedantic)
2389 Common Var(flag_pedantic_errors)
2390 Like -pedantic but issue them as errors
2396 Driver Var(use_pipes)
2399 Driver JoinedOrMissing Var(print_file_name)
2401 print-libgcc-file-name
2404 print-multi-directory
2405 Driver Var(print_multi_directory)
2408 Driver Var(print_multi_lib)
2410 print-multi-os-directory
2411 Driver Var(print_multi_os_directory)
2414 Driver JoinedOrMissing Var(print_prog_name)
2417 Driver Var(print_search_dirs)
2420 Driver Var(print_sysroot)
2422 print-sysroot-headers-suffix
2423 Driver Var(print_sysroot_headers_suffix)
2426 Common Var(quiet_flag) RejectDriver
2427 Do not display functions compiled or elapsed time
2445 Driver Var(report_times)
2448 Driver JoinedOrMissing
2451 Driver Joined Separate
2455 ; C option, but driver must not handle as "-u ndef".
2458 Common Driver Var(verbose_flag)
2459 Enable verbose output
2462 Common Var(version_flag) RejectDriver
2463 Display the compiler's version
2466 Common Var(inhibit_warnings)
2470 Driver Separate Var(wrapper_string)
2473 Driver Joined Separate
2476 Driver RejectNegative Negative(pie)
2477 Create a shared library
2483 Driver Separate Alias(specs=)
2496 ; Documented for Fortran, but always accepted by driver.
2503 ; Documented for Go, but always accepted by driver.
2509 Driver RejectNegative Negative(shared)
2510 Create a position independent executable
2513 Driver Joined Separate
2515 ; This comment is to ensure we retain the blank line above.