1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2014 Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
49 ; 0 means straightforward implementation of complex divide acceptable.
50 ; 1 means wide ranges of inputs must work for complex divide.
51 ; 2 means C99-like requirements for complex multiply and divide.
53 int flag_complex_method = 1
55 ; Nonzero if subexpressions must be evaluated from left-to-right.
57 int flag_evaluation_order = 0
59 ; Language specific warning pass for unused results.
61 bool flag_warn_unused_result = false
66 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
70 ; True to warn about any objects definitions whose size is larger
71 ; than N bytes. Also want about function definitions whose returned
72 ; values are larger than N bytes, where N is 'larger_than_size'.
77 HOST_WIDE_INT larger_than_size
79 ; True to warn about any function whose frame size is larger
82 bool warn_frame_larger_than
85 HOST_WIDE_INT frame_larger_than_size
87 ; Nonzero means we should be saving declaration info into a .X file.
89 int flag_gen_aux_info = 0
91 ; Nonzero if we are compiling code for a shared library, zero for
96 ; These two are really VEC(char_p,heap) *.
99 void *flag_instrument_functions_exclude_functions
102 void *flag_instrument_functions_exclude_files
104 ; Generic structs (e.g. templates not explicitly specialized)
105 ; may not have a compilation unit associated with them, and so
106 ; may need to be treated differently from ordinary structs.
108 ; Structs only handled by reference (indirectly), will also usually
109 ; not need as much debugging information.
112 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
117 ; True if we should exit after parsing options.
119 bool exit_after_options
121 ; Type(s) of debugging information we are producing (if any). See
122 ; flag-types.h for the definitions of the different possible types of
123 ; debugging information.
125 enum debug_info_type write_symbols = NO_DEBUG
127 ; Level of debugging information we are producing. See flag-types.h
128 ; for the definitions of the different possible levels.
130 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
132 ; Nonzero means use GNU-only extensions in the generated symbolic
133 ; debugging information. Currently, this only has an effect when
134 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
136 bool use_gnu_debug_info_extensions
138 ; Original value of maximum field alignment in bytes, specified via
139 ; -fpack-struct=<value>.
141 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
143 ; Type of stack check.
145 enum stack_check_type flag_stack_check = NO_STACK_CHECK
147 ; True if stack usage information needs to be computed.
149 bool flag_stack_usage_info = false
151 ; -dA causes debug commentary information to be produced in
152 ; the generated assembly code (to make it more readable). This option
153 ; is generally only of use to those who actually need to read the
154 ; generated assembly code (perhaps while debugging the compiler itself).
155 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
156 ; to be a catchall for printing debug information in the assembler file.
160 ; -dP causes the rtl to be emitted as a comment in assembly.
162 int flag_dump_rtl_in_asm
164 ; Whether -da was passed (used only in handle_common_deferred_options).
166 bool flag_dump_all_passed
168 ; Other flags saying which kinds of debugging dump have been requested.
171 int rtl_dump_and_exit
174 int flag_print_asm_name
176 ; Name of top-level original source file (what was input to cpp).
177 ; This comes from the #-command at the beginning of the actual input.
178 ; If there isn't any there, then this is the cc1 input file name.
180 const char *main_input_filename
182 ; Pointer to base name in main_input_filename, with directories and a
183 ; single final extension removed, and the length of this base
187 const char *main_input_basename
190 int main_input_baselength
192 ; Which options have been printed by --help.
196 ; Which enums have been printed by --help. 0 = not printed, no
197 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
200 char *help_enum_printed
202 ; The number of columns for --help output.
204 unsigned int help_columns
206 ; Whether this options structure has been through finish_options
208 bool flag_opts_finished
210 ; What the sanitizer should instrument
212 unsigned int flag_sanitize
214 ; Flag whether a prefix has been added to dump_base_name
216 bool dump_base_name_prefixed = false
228 Driver Alias(coverage)
234 Common Separate Alias(d)
237 Common Joined Alias(d)
240 Common Separate Alias(dumpbase)
243 Common Separate Alias(dumpdir)
246 Driver Separate Alias(e)
249 Driver Joined Alias(e)
252 Common Warning Alias(Wextra)
255 Driver Separate Alias(Xassembler)
258 Driver JoinedOrMissing Alias(Xassembler)
261 Driver Separate Alias(Xlinker)
264 Driver JoinedOrMissing Alias(Xlinker)
267 Driver Separate Alias(u)
270 Driver Joined Alias(u)
273 Common Driver Var(help_flag)
274 Display this information
277 Common Driver Report Joined
278 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
281 Driver Separate Alias(x)
284 Driver Joined Alias(x)
287 Driver Separate Alias(L)
290 Driver Joined Alias(L)
292 -no-canonical-prefixes
293 Driver Alias(no-canonical-prefixes)
295 -no-standard-libraries
296 Driver Alias(nostdlib)
299 Driver Var(no_sysroot_suffix)
308 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
311 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
314 Driver Alias(pass-exit-codes)
317 Common Alias(Wpedantic)
320 Common Alias(pedantic-errors)
329 Driver Separate Alias(B)
332 Driver JoinedOrMissing Alias(B)
338 Driver Separate Alias(print-file-name=)
341 Driver JoinedOrMissing Alias(print-file-name=)
343 -print-libgcc-file-name
344 Driver Alias(print-libgcc-file-name)
346 -print-multi-directory
347 Driver Alias(print-multi-directory)
350 Driver Alias(print-multi-lib)
352 -print-multi-os-directory
353 Driver Alias(print-multi-os-directory)
356 Driver Alias(print-multiarch)
359 Driver Separate Alias(print-prog-name=)
362 Driver JoinedOrMissing Alias(print-prog-name=)
365 Driver Alias(print-search-dirs)
368 Driver Alias(print-sysroot)
370 -print-sysroot-headers-suffix
371 Driver Alias(print-sysroot-headers-suffix)
377 Driver Alias(save-temps)
383 Driver Separate Alias(specs=)
386 Driver Joined Alias(specs=)
392 Driver Alias(symbolic)
396 Alias for --help=target
404 ;; The driver used to convert options such as --help into forms such
405 ;; as -fhelp; the following four entries are for compatibility with
406 ;; any direct uses of those (undocumented) -f forms
408 Common Driver Alias(-help)
411 Common Driver Joined Alias(-help=)
414 Common Driver Alias(-target-help)
417 Common Driver Alias(-version)
421 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
424 Common Joined Alias(-param)
427 Driver Separate Alias(-sysroot=)
430 Driver JoinedOrMissing
436 Driver Joined Separate
442 Driver Joined Separate
448 Common JoinedOrMissing Optimization
449 -O<number> Set optimization level to <number>
453 Optimize for space rather than speed
457 Optimize for speed disregarding exact standards compliance
461 Optimize for debugging experience rather than speed or size
473 Driver Joined Separate
479 Driver Joined Separate
500 Common RejectNegative Warning Alias(Wextra)
501 This switch is deprecated; use -Wextra instead
504 Driver JoinedOrMissing
507 Driver JoinedOrMissing
510 Driver JoinedOrMissing
513 Common Var(warn_aggregate_return) Warning
514 Warn about returning structures, unions or arrays
516 Waggressive-loop-optimizations
517 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
518 Warn if a loop with constant number of iterations triggers undefined behavior
521 Common Var(warn_array_bounds) Warning
522 Warn if an array is accessed out of bounds
525 Common Var(warn_attributes) Init(1) Warning
526 Warn about inappropriate attribute usage
529 Common Var(warn_cast_align) Warning
530 Warn about pointer casts which increase alignment
533 Common Var(warn_cpp) Init(1) Warning
534 Warn when a #warning directive is encountered
536 Wdeprecated-declarations
537 Common Var(warn_deprecated_decl) Init(1) Warning
538 Warn about uses of __attribute__((deprecated)) declarations
540 Wdisabled-optimization
541 Common Var(warn_disabled_optimization) Warning
542 Warn when an optimization pass is disabled
545 Common Var(warnings_are_errors)
546 Treat all warnings as errors
550 Treat specified warning as error
553 Common Var(extra_warnings) Warning
554 Print extra (possibly unwanted) warnings
557 Common Var(flag_fatal_errors)
558 Exit on the first error occurred
561 Common RejectNegative Joined UInteger
562 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
565 Common Var(warn_free_nonheap_object) Init(1) Warning
566 Warn when attempting to free a non-heap object
569 Common Var(warn_inline) Warning
570 Warn when an inlined function cannot be inlined
572 Winvalid-memory-model
573 Common Var(warn_invalid_memory_model) Init(1) Warning
574 Warn when an atomic memory model parameter is known to be outside the valid range.
577 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
580 Common RejectNegative Joined UInteger Warning
581 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
583 Wunsafe-loop-optimizations
584 Common Var(warn_unsafe_loop_optimizations) Warning
585 Warn if the loop cannot be optimized due to nontrivial assumptions.
588 Common Alias(Wsuggest-attribute=noreturn)
591 Common Var(warn_overflow) Init(1) Warning
592 Warn about overflow in arithmetic expressions
595 Common Var(warn_packed) Warning
596 Warn when the packed attribute has no effect on struct layout
599 Common Var(warn_padded) Warning
600 Warn when padding is required to align structure members
603 Common Var(pedantic) Warning
604 Issue warnings needed for strict compliance to the standard
607 Common Var(warn_shadow) Warning
608 Warn when one local variable shadows another
611 Common Var(warn_stack_protect) Warning
612 Warn when not issuing stack smashing protection for some reason
615 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
616 Warn if stack usage might be larger than specified amount
620 Warn about code which might break strict aliasing rules
623 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
624 Warn about code which might break strict aliasing rules
628 Warn about optimizations that assume that signed overflow is undefined
631 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
632 Warn about optimizations that assume that signed overflow is undefined
634 Wsuggest-attribute=const
635 Common Var(warn_suggest_attribute_const) Warning
636 Warn about functions which might be candidates for __attribute__((const))
638 Wsuggest-attribute=pure
639 Common Var(warn_suggest_attribute_pure) Warning
640 Warn about functions which might be candidates for __attribute__((pure))
642 Wsuggest-attribute=noreturn
643 Common Var(warn_suggest_attribute_noreturn) Warning
644 Warn about functions which might be candidates for __attribute__((noreturn))
647 Common Var(warn_system_headers) Warning
648 Do not suppress warnings from system headers
651 Common Var(warn_trampolines) Warning
652 Warn whenever a trampoline is generated
655 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
656 Warn if a comparison is always true or always false due to the limited range of the data type
659 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
660 Warn about uninitialized automatic variables
663 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
664 Warn about maybe uninitialized automatic variables
668 Does nothing. Preserved for backward compatibility.
671 Common Var(warn_unused) Init(0) Warning
672 Enable all -Wunused- warnings
674 Wunused-but-set-parameter
675 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
676 Warn when a function parameter is only set, otherwise unused
678 Wunused-but-set-variable
679 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
680 Warn when a variable is only set, otherwise unused
683 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
684 Warn when a function is unused
687 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
688 Warn when a label is unused
691 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
692 Warn when a function parameter is unused
695 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
696 Warn when an expression value is unused
699 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
700 Warn when a variable is unused
703 Common Var(warn_coverage_mismatch) Init(1) Warning
704 Warn in case profiles in -fprofile-use do not match
706 Wvector-operation-performance
707 Common Var(warn_vector_operation_performance) Warning
708 Warn when a vector operation is compiled outside the SIMD
723 Common Separate Var(aux_info_file_name)
724 -aux-info <file> Emit declaration information into <file>
727 Common Joined Alias(aux-info)
730 Common Separate RejectDriver Var(aux_base_name)
733 Common Separate RejectDriver
743 -d<letters> Enable dumps from specific passes of the compiler
746 Common Separate Var(dump_base_name)
747 -dumpbase <file> Set the file basename to be used for dumps
750 Common Separate Var(dump_dir_name)
751 -dumpdir <dir> Set the directory name to be used for dumps
763 Driver Joined Separate
765 ; This option has historically been passed down to the linker by an
766 ; accident of a %{e*} spec, so ensure it continues to be passed down
767 ; as a single option. The supported option for this purpose is
768 ; -rdynamic. See PR 47390.
772 ; The version of the C++ ABI in use. The following values are allowed:
774 ; 0: The version of the ABI believed most conformant with the C++ ABI
775 ; specification. This ABI may change as bugs are discovered and fixed.
776 ; Therefore, 0 will not necessarily indicate the same ABI in different
779 ; 1: The version of the ABI first used in G++ 3.2.
781 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
783 ; 3: The version of the ABI that fixes the missing underscore
784 ; in template non-type arguments of pointer type.
786 ; 4: The version of the ABI that introduces unambiguous mangling of
787 ; vector types. First selectable in G++ 4.5.
789 ; 5: The version of the ABI that ignores attribute const/noreturn
790 ; in function pointer mangling, and corrects mangling of decltype and
791 ; function parameters used in other parameters and the return type.
792 ; First selectable in G++ 4.6.
794 ; 6: The version of the ABI that doesn't promote scoped enums to int and
795 ; changes the mangling of template argument packs, const/static_cast,
796 ; prefix ++ and --, and a class scope function used as a template
798 ; First selectable in G++ 4.7.
800 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
801 ; corrects the mangling of lambdas in default argument scope.
802 ; First selectable in G++ 4.8.
804 ; 8: The version of the ABI that corrects the substitution behavior of
805 ; function types with function-cv-qualifiers.
806 ; First selectable in G++ 4.9.
808 ; Additional positive integers will be assigned as new versions of
809 ; the ABI become the default version of the ABI.
811 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
813 faggressive-loop-optimizations
814 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
815 Aggressively optimize loops using language constraints
818 Common Report Var(align_functions,0) Optimization UInteger
819 Align the start of functions
822 Common RejectNegative Joined UInteger Var(align_functions)
825 Common Report Var(align_jumps,0) Optimization UInteger
826 Align labels which are only reached by jumping
829 Common RejectNegative Joined UInteger Var(align_jumps)
832 Common Report Var(align_labels,0) Optimization UInteger
836 Common RejectNegative Joined UInteger Var(align_labels)
839 Common Report Var(align_loops,0) Optimization UInteger
840 Align the start of loops
843 Common RejectNegative Joined UInteger Var(align_loops)
847 Does nothing. Preserved for backward compatibility.
851 Does nothing. Preserved for backward compatibility.
853 fargument-noalias-global
855 Does nothing. Preserved for backward compatibility.
857 fargument-noalias-anything
859 Does nothing. Preserved for backward compatibility.
862 Common Driver Report Joined
863 Select what to sanitize
865 fasynchronous-unwind-tables
866 Common Report Var(flag_asynchronous_unwind_tables) Optimization
867 Generate unwind tables that are exact at each instruction boundary
870 Common Report Var(flag_auto_inc_dec) Init(1)
871 Generate auto-inc/dec instructions
873 ; -fcheck-bounds causes gcc to generate array bounds checks.
874 ; For C, C++ and ObjC: defaults off.
875 ; For Java: defaults to on.
876 ; For Fortran: defaults to off.
878 Common Report Var(flag_bounds_check)
879 Generate code to check bounds before indexing arrays
882 Common Report Var(flag_branch_on_count_reg) Optimization
883 Replace add, compare, branch with branch on count register
885 fbranch-probabilities
886 Common Report Var(flag_branch_probabilities) Optimization
887 Use profiling information for branch probabilities
889 fbranch-target-load-optimize
890 Common Report Var(flag_branch_target_load_optimize) Optimization
891 Perform branch target load optimization before prologue / epilogue threading
893 fbranch-target-load-optimize2
894 Common Report Var(flag_branch_target_load_optimize2) Optimization
895 Perform branch target load optimization after prologue / epilogue threading
898 Common Report Var(flag_btr_bb_exclusive) Optimization
899 Restrict target load migration not to re-use registers in any basic block
902 Common Joined RejectNegative Var(common_deferred_options) Defer
903 -fcall-saved-<register> Mark <register> as being preserved across functions
906 Common Joined RejectNegative Var(common_deferred_options) Defer
907 -fcall-used-<register> Mark <register> as being corrupted by function calls
909 ; Nonzero for -fcaller-saves: allocate values in regs that need to
910 ; be saved across function calls, if that produces overall better code.
911 ; Optional now, so people can test it.
913 Common Report Var(flag_caller_saves) Optimization
914 Save registers around function calls
917 Common Report Var(flag_check_data_deps)
918 Compare the results of several data dependence analyzers.
921 Common Var(flag_check_new)
922 Check the return value of new in C++
924 fcombine-stack-adjustments
925 Common Report Var(flag_combine_stack_adjustments) Optimization
926 Looks for opportunities to reduce stack adjustments and stack references.
929 Common Report Var(flag_no_common,0) Optimization
930 Do not put uninitialized globals in the common section
934 ; Converted by the driver to -fcompare-debug= options.
937 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
938 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
940 fcompare-debug-second
941 Common Driver RejectNegative Var(flag_compare_debug)
942 Run only the second compilation of -fcompare-debug
945 Common Report Var(flag_compare_elim_after_reload) Optimization
946 Perform comparison elimination after register allocation has finished
949 Common Var(flag_conserve_stack) Optimization
950 Do not perform optimizations increasing noticeably stack usage
953 Common Report Var(flag_cprop_registers) Optimization
954 Perform a register copy-propagation optimization pass
957 Common Report Var(flag_crossjumping) Optimization
958 Perform cross-jumping optimization
961 Common Report Var(flag_cse_follow_jumps) Optimization
962 When running CSE, follow jumps to their targets
966 Does nothing. Preserved for backward compatibility.
969 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
970 Omit range reduction step when performing complex division
973 Common Report Var(flag_cx_fortran_rules) Optimization
974 Complex multiplication and division follow Fortran rules
977 Common Report Var(flag_data_sections) Optimization
978 Place data items into their own section
981 Common Report Var(common_deferred_options) Defer
982 List all available debugging counters with their limits and counts.
985 Common RejectNegative Joined Var(common_deferred_options) Defer
986 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
989 Common Joined RejectNegative Var(common_deferred_options) Defer
990 Map one directory name to another in debug information
993 Common Report Var(flag_debug_types_section) Init(0)
994 Output .debug_types section when using DWARF v4 debuginfo.
996 ; Nonzero for -fdefer-pop: don't pop args after each function call
997 ; instead save them up to pop many calls' args with one insns.
999 Common Report Var(flag_defer_pop) Optimization
1000 Defer popping functions args from stack until later
1003 Common Report Var(flag_delayed_branch) Optimization
1004 Attempt to fill delay slots of branch instructions
1006 fdelete-dead-exceptions
1007 Common Report Var(flag_delete_dead_exceptions) Init(0)
1008 Delete dead instructions that may throw exceptions
1010 fdelete-null-pointer-checks
1011 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
1012 Delete useless null pointer checks
1014 fdevirtualize-speculatively
1015 Common Report Var(flag_devirtualize_speculatively) Optimization
1016 Perform speculative devirtualization
1019 Common Report Var(flag_devirtualize) Optimization
1020 Try to convert virtual calls to direct ones.
1022 fdiagnostics-show-location=
1023 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1024 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1026 ; Required for these enum values.
1031 Name(diagnostic_prefixing_rule) Type(int)
1034 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1037 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1039 fdiagnostics-show-caret
1040 Common Var(flag_diagnostics_show_caret) Init(1)
1041 Show the source line with a caret indicating the column
1044 Common Alias(fdiagnostics-color=,always,never)
1048 Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1049 -fdiagnostics-color=[never|always|auto] Colorize diagnostics
1051 ; Required for these enum values.
1056 Name(diagnostic_color_rule) Type(int)
1059 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1062 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1065 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1067 fdiagnostics-show-option
1068 Common Var(flag_diagnostics_show_option) Init(1)
1069 Amend appropriate diagnostic messages with the command line option that controls them
1072 Common Joined RejectNegative Var(common_deferred_options) Defer
1073 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1076 Common Joined RejectNegative Var(common_deferred_options) Defer
1077 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1080 Common Joined RejectNegative Var(common_deferred_options) Defer
1081 -fdump-<type> Dump various compiler internals to a file
1084 Driver RejectNegative
1087 Common RejectNegative Joined Var(flag_dump_final_insns)
1088 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1091 Common RejectNegative Joined Var(flag_dump_go_spec)
1092 -fdump-go-spec=filename Write all declarations to file as Go code
1095 Common Report Var(flag_dump_noaddr)
1096 Suppress output of addresses in debugging dumps
1099 Common Var(flag_dump_passes) Init(0)
1100 Dump optimization passes
1103 Common Report Var(flag_dump_unnumbered)
1104 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1106 fdump-unnumbered-links
1107 Common Report Var(flag_dump_unnumbered_links)
1108 Suppress output of previous and next insn numbers in debugging dumps
1111 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1112 Enable CFI tables via GAS assembler directives.
1115 Common Report Var(flag_early_inlining) Init(1) Optimization
1116 Perform early inlining
1118 feliminate-dwarf2-dups
1119 Common Report Var(flag_eliminate_dwarf2_dups)
1120 Perform DWARF2 duplicate elimination
1123 Common Report Var(flag_ipa_sra) Init(0) Optimization
1124 Perform interprocedural reduction of aggregates
1126 feliminate-unused-debug-symbols
1127 Common Report Var(flag_debug_only_used_symbols)
1128 Perform unused type elimination in debug info
1130 feliminate-unused-debug-types
1131 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1132 Perform unused type elimination in debug info
1134 femit-class-debug-always
1135 Common Report Var(flag_emit_class_debug_always) Init(0)
1136 Do not suppress C++ class debug information.
1139 Common Report Var(flag_exceptions) Optimization
1140 Enable exception handling
1142 fexpensive-optimizations
1143 Common Report Var(flag_expensive_optimizations) Optimization
1144 Perform a number of minor, expensive optimizations
1147 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1148 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1151 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1154 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1157 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1163 Common Var(flag_fat_lto_objects)
1164 Output lto objects containing both the intermediate language and binary output.
1167 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1168 Assume no NaNs or infinities are generated
1171 Common Joined RejectNegative Var(common_deferred_options) Defer
1172 -ffixed-<register> Mark <register> as being unavailable to the compiler
1175 Common Report Var(flag_float_store) Optimization
1176 Don't allocate floats and doubles in extended-precision registers
1180 Does nothing. Preserved for backward compatibility.
1183 Common Report Var(flag_forward_propagate) Optimization
1184 Perform a forward propagation pass on RTL
1187 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1188 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1191 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1194 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1196 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1198 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1201 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1203 ; Nonzero means don't put addresses of constant functions in registers.
1204 ; Used for compiling the Unix kernel, where strange substitutions are
1205 ; done on the assembly output.
1207 Common Report Var(flag_no_function_cse,0)
1208 Allow function addresses to be held in registers
1211 Common Report Var(flag_function_sections)
1212 Place each function into its own section
1215 Common Report Var(flag_gcse) Optimization
1216 Perform global common subexpression elimination
1219 Common Report Var(flag_gcse_lm) Init(1) Optimization
1220 Perform enhanced load motion during global common subexpression elimination
1223 Common Report Var(flag_gcse_sm) Init(0) Optimization
1224 Perform store motion after global common subexpression elimination
1227 Common Report Var(flag_gcse_las) Init(0) Optimization
1228 Perform redundant load after store elimination in global common subexpression
1232 Common Report Var(flag_gcse_after_reload) Optimization
1233 Perform global common subexpression elimination after register allocation
1236 ; This option is not documented yet as its semantics will change.
1238 Common Report Var(flag_graphite)
1239 Enable in and out of Graphite representation
1242 Common Report Var(flag_graphite_identity) Optimization
1243 Enable Graphite Identity transformation
1245 fhoist-adjacent-loads
1246 Common Report Var(flag_hoist_adjacent_loads) Optimization
1247 Enable hoisting adjacent loads to encourage generating conditional move
1250 floop-parallelize-all
1251 Common Report Var(flag_loop_parallelize_all) Optimization
1252 Mark all loops as parallel
1255 Common Report Var(flag_loop_strip_mine) Optimization
1256 Enable Loop Strip Mining transformation
1259 Common Report Var(flag_loop_interchange) Optimization
1260 Enable Loop Interchange transformation
1263 Common Report Var(flag_loop_block) Optimization
1264 Enable Loop Blocking transformation
1267 Common Report Var(flag_tm)
1268 Enable support for GNU transactional memory
1271 Common Report Var(flag_gnu_unique) Init(1)
1272 Use STB_GNU_UNIQUE if supported by the assembler
1276 Does nothing. Preserved for backward compatibility.
1279 Common Report Var(flag_loop_optimize_isl) Optimization
1280 Enable the ISL based loop nest optimizer
1282 fstrict-volatile-bitfields
1283 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1284 Force bitfield accesses to match their type width
1286 fguess-branch-probability
1287 Common Report Var(flag_guess_branch_prob) Optimization
1288 Enable guessing of branch probabilities
1290 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1291 ; Generate position-independent code for executables if possible
1292 ; On SVR4 targets, it also controls whether or not to emit a
1293 ; string identifying the compiler.
1295 Common Report Var(flag_no_ident,0)
1296 Process #ident directives
1299 Common Report Var(flag_if_conversion) Optimization
1300 Perform conversion of conditional jumps to branchless equivalents
1303 Common Report Var(flag_if_conversion2) Optimization
1304 Perform conversion of conditional jumps to conditional execution
1307 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1308 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1311 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1314 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1317 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1320 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1322 ftree-loop-if-convert
1323 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1324 Convert conditional jumps in innermost loops to branchless equivalents
1326 ftree-loop-if-convert-stores
1327 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1328 Also if-convert conditional jumps containing memory writes
1330 ; -finhibit-size-directive inhibits output of .size for ELF.
1331 ; This is used only for compiling crtstuff.c,
1332 ; and it may be extended to other effects
1333 ; needed for crtstuff.c on other systems.
1334 finhibit-size-directive
1335 Common Report Var(flag_inhibit_size_directive)
1336 Do not generate .size directives
1339 Common Report Var(flag_indirect_inlining)
1340 Perform indirect inlining
1342 ; General flag to enable inlining. Specifying -fno-inline will disable
1343 ; all inlining apart from always-inline functions.
1345 Common Report Var(flag_no_inline,0) Init(0) Optimization
1346 Enable inlining of function declared \"inline\", disabling disables all inlining
1348 finline-small-functions
1349 Common Report Var(flag_inline_small_functions) Optimization
1350 Integrate functions into their callers when code size is known not to grow
1353 Common Report Var(flag_inline_functions) Optimization
1354 Integrate functions not declared \"inline\" into their callers when profitable
1356 finline-functions-called-once
1357 Common Report Var(flag_inline_functions_called_once) Optimization
1358 Integrate functions only required by their single caller
1361 Common RejectNegative Joined Alias(finline-limit=)
1364 Common RejectNegative Joined UInteger
1365 -finline-limit=<number> Limit the size of inlined functions to <number>
1368 Common Report Var(flag_inline_atomics) Init(1) Optimization
1369 Inline __atomic operations when a lock free instruction sequence is available.
1371 finstrument-functions
1372 Common Report Var(flag_instrument_function_entry_exit)
1373 Instrument function entry and exit with profiling calls
1375 finstrument-functions-exclude-function-list=
1376 Common RejectNegative Joined
1377 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1379 finstrument-functions-exclude-file-list=
1380 Common RejectNegative Joined
1381 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1384 Common Report Var(flag_ipa_cp) Optimization
1385 Perform interprocedural constant propagation
1388 Common Report Var(flag_ipa_cp_clone) Optimization
1389 Perform cloning to make Interprocedural constant propagation stronger
1392 Common Report Var(flag_ipa_profile) Init(0) Optimization
1393 Perform interprocedural profile propagation
1396 Common Report Var(flag_ipa_pta) Init(0) Optimization
1397 Perform interprocedural points-to analysis
1400 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1401 Discover pure and const functions
1404 Common Report Var(flag_ipa_reference) Init(0) Optimization
1405 Discover readonly and non addressable static variables
1409 Does nothing. Preserved for backward compatibility.
1413 Does nothing. Preserved for backward compatibility.
1416 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1417 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1420 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1423 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1426 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1429 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1430 -fira-region=[one|all|mixed] Set regions for IRA
1433 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1436 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1439 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1442 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1445 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1446 Use IRA based register pressure calculation
1447 in RTL hoist optimizations.
1450 Common Report Var(flag_ira_loop_pressure) Optimization
1451 Use IRA based register pressure calculation
1452 in RTL loop optimizations.
1454 fira-share-save-slots
1455 Common Report Var(flag_ira_share_save_slots) Init(1)
1456 Share slots for saving different hard registers.
1458 fira-share-spill-slots
1459 Common Report Var(flag_ira_share_spill_slots) Init(1)
1460 Share stack slots for spilled pseudo-registers.
1463 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1464 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1467 Common Report Var(flag_ivopts) Init(1) Optimization
1468 Optimize induction variables on trees
1471 Common Var(flag_jump_tables) Init(1) Optimization
1472 Use jump tables for sufficiently large switch statements
1474 fkeep-inline-functions
1475 Common Report Var(flag_keep_inline_functions)
1476 Generate code for functions even if they are fully inlined
1479 Common Report Var(flag_keep_static_consts) Init(1)
1480 Emit static const variables even if they are not used
1483 Common Report Var(flag_leading_underscore) Init(-1)
1484 Give external symbols a leading underscore
1488 Does nothing. Preserved for backward compatibility.
1492 Enable link-time optimization.
1495 Common RejectNegative Joined Var(flag_lto)
1496 Link-time optimization with number of parallel jobs or jobserver.
1499 Common Var(flag_lto_partition_1to1)
1500 Partition symbols and vars at linktime based on object files they originate from
1502 flto-partition=balanced
1503 Common Var(flag_lto_partition_balanced)
1504 Partition functions and vars at linktime into approximately same sized buckets
1507 Common Var(flag_lto_partition_max)
1508 Put every symbol into separate partition
1511 Common Var(flag_lto_partition_none)
1512 Disable partioning and streaming
1514 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1515 flto-compression-level=
1516 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1517 -flto-compression-level=<number> Use zlib compression level <number> for IL
1520 Common Report Var(flag_lto_report) Init(0)
1521 Report various link-time optimization statistics
1524 Common Report Var(flag_lto_report_wpa) Init(0)
1525 Report various link-time optimization statistics for WPA only
1528 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1529 Set errno after built-in math functions
1532 Common Joined RejectNegative UInteger Var(flag_max_errors)
1533 -fmax-errors=<number> Maximum number of errors to report
1536 Common Report Var(mem_report)
1537 Report on permanent memory allocation
1540 Common Report Var(mem_report_wpa)
1541 Report on permanent memory allocation in WPA only
1543 ; This will attempt to merge constant section constants, if 1 only
1544 ; string constants and constants from constant pool, if 2 also constant
1546 fmerge-all-constants
1547 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1548 Attempt to merge identical constants and constant variables
1551 Common Report Var(flag_merge_constants,1) Optimization
1552 Attempt to merge identical constants across compilation units
1554 fmerge-debug-strings
1555 Common Report Var(flag_merge_debug_strings) Init(1)
1556 Attempt to merge identical debug strings across compilation units
1559 Common RejectNegative Joined UInteger
1560 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1563 Common Report Var(flag_modulo_sched) Optimization
1564 Perform SMS based modulo scheduling before the first scheduling pass
1566 fmodulo-sched-allow-regmoves
1567 Common Report Var(flag_modulo_sched_allow_regmoves)
1568 Perform SMS based modulo scheduling with register moves allowed
1570 fmove-loop-invariants
1571 Common Report Var(flag_move_loop_invariants) Optimization
1572 Move loop invariant computations out of loops
1575 Common Var(flag_dce) Init(1) Optimization
1576 Use the RTL dead code elimination pass
1579 Common Var(flag_dse) Init(1) Optimization
1580 Use the RTL dead store elimination pass
1582 freschedule-modulo-scheduled-loops
1583 Common Report Var(flag_resched_modulo_sched) Optimization
1584 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1586 fnon-call-exceptions
1587 Common Report Var(flag_non_call_exceptions) Optimization
1588 Support synchronous non-call exceptions
1591 Common Report Var(flag_omit_frame_pointer) Optimization
1592 When possible do not generate stack frames
1595 Common Report Var(flag_opt_info) Optimization
1596 Enable all optimization info dumps on stderr
1599 Common Joined RejectNegative Var(common_deferred_options) Defer
1600 -fopt-info[-<type>=filename] Dump compiler optimization details
1602 foptimize-register-move
1604 Does nothing. Preserved for backward compatibility.
1606 foptimize-sibling-calls
1607 Common Report Var(flag_optimize_sibling_calls) Optimization
1608 Optimize sibling and tail recursive calls
1611 Common Report Var(flag_partial_inlining)
1612 Perform partial inlining
1615 Common Report Var(pre_ipa_mem_report)
1616 Report on memory allocation before interprocedural optimization
1618 fpost-ipa-mem-report
1619 Common Report Var(post_ipa_mem_report)
1620 Report on memory allocation before interprocedural optimization
1623 Common Report Var(flag_pack_struct) Optimization
1624 Pack structure members together without holes
1627 Common RejectNegative Joined UInteger Optimization
1628 -fpack-struct=<number> Set initial maximum structure member alignment
1631 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1632 Return small aggregates in memory, not registers
1635 Common Report Var(flag_peel_loops) Optimization
1636 Perform loop peeling
1639 Common Report Var(flag_no_peephole,0) Optimization
1640 Enable machine specific peephole optimizations
1643 Common Report Var(flag_peephole2) Optimization
1644 Enable an RTL peephole pass before sched2
1647 Common Report Var(flag_pic,2) Negative(fPIE)
1648 Generate position-independent code if possible (large mode)
1651 Common Report Var(flag_pie,2) Negative(fpic)
1652 Generate position-independent code for executables if possible (large mode)
1655 Common Report Var(flag_pic,1) Negative(fpie)
1656 Generate position-independent code if possible (small mode)
1659 Common Report Var(flag_pie,1) Negative(fPIC)
1660 Generate position-independent code for executables if possible (small mode)
1663 Common Joined RejectNegative Var(common_deferred_options) Defer
1664 Specify a plugin to load
1667 Common Joined RejectNegative Var(common_deferred_options) Defer
1668 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1670 fpredictive-commoning
1671 Common Report Var(flag_predictive_commoning) Optimization
1672 Run predictive commoning optimization.
1674 fprefetch-loop-arrays
1675 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1676 Generate prefetch instructions, if available, for arrays in loops
1679 Common Report Var(profile_flag)
1680 Enable basic program profiling code
1683 Common Report Var(profile_arc_flag)
1684 Insert arc-based program profiling code
1687 Common Joined RejectNegative Var(profile_data_prefix)
1688 Set the top-level directory for storing the profile data.
1689 The default is 'pwd'.
1692 Common Report Var(flag_profile_correction)
1693 Enable correction of flow inconsistent profile data input
1697 Enable common options for generating profile info for profile feedback directed optimizations
1700 Common Joined RejectNegative
1701 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1704 Common Var(flag_profile_use)
1705 Enable common options for performing profile feedback directed optimizations
1708 Common Joined RejectNegative
1709 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1712 Common Report Var(flag_profile_values)
1713 Insert code to profile values of expressions
1716 Common Report Var(profile_report)
1717 Report on consistency of profile
1719 fprofile-reorder-functions
1720 Common Report Var(flag_profile_reorder_functions)
1721 Enable function reordering that improves code placement
1724 Common Var(common_deferred_options) Defer
1727 Common Joined RejectNegative Var(common_deferred_options) Defer
1728 -frandom-seed=<string> Make compile reproducible using <string>
1730 ; This switch causes the command line that was used to create an
1731 ; object file to be recorded into the object file. The exact format
1732 ; of this recording is target and binary file format dependent.
1733 ; It is related to the -fverbose-asm switch, but that switch only
1734 ; records information in the assembler output file as comments, so
1735 ; they never reach the object file.
1736 frecord-gcc-switches
1737 Common Report Var(flag_record_gcc_switches)
1738 Record gcc command line switches in the object file.
1741 Common Report Var(flag_pcc_struct_return,0) Optimization
1742 Return small aggregates in registers
1746 Does nothing. Preserved for backward compatibility.
1748 flive-range-shrinkage
1749 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
1750 Relief of register pressure through live range shrinkage
1753 Common Report Var(flag_rename_registers) Init(2) Optimization
1754 Perform a register renaming optimization pass
1757 Common Report Var(flag_reorder_blocks) Optimization
1758 Reorder basic blocks to improve code placement
1760 freorder-blocks-and-partition
1761 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1762 Reorder basic blocks and partition into hot and cold sections
1765 Common Report Var(flag_reorder_functions) Optimization
1766 Reorder functions to improve code placement
1768 frerun-cse-after-loop
1769 Common Report Var(flag_rerun_cse_after_loop) Optimization
1770 Add a common subexpression elimination pass after loop optimizations
1774 Does nothing. Preserved for backward compatibility.
1777 Common Report Var(flag_rounding_math) Optimization SetByCombined
1778 Disable optimizations that assume default FP rounding behavior
1781 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1782 Enable scheduling across basic blocks
1785 Common Report Var(flag_sched_pressure) Init(0) Optimization
1786 Enable register pressure sensitive insn scheduling
1789 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1790 Allow speculative motion of non-loads
1793 Common Report Var(flag_schedule_speculative_load) Optimization
1794 Allow speculative motion of some loads
1796 fsched-spec-load-dangerous
1797 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1798 Allow speculative motion of more loads
1801 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1802 -fsched-verbose=<number> Set the verbosity level of the scheduler
1804 fsched2-use-superblocks
1805 Common Report Var(flag_sched2_use_superblocks) Optimization
1806 If scheduling post reload, do superblock scheduling
1810 Does nothing. Preserved for backward compatibility.
1813 Common Report Var(flag_schedule_insns) Optimization
1814 Reschedule instructions before register allocation
1817 Common Report Var(flag_schedule_insns_after_reload) Optimization
1818 Reschedule instructions after register allocation
1820 ; This flag should be on when a target implements non-trivial
1821 ; scheduling hooks, maybe saving some information for its own sake.
1822 ; On IA64, for example, this is used for correct bundling.
1823 fselective-scheduling
1824 Common Report Var(flag_selective_scheduling) Optimization
1825 Schedule instructions using selective scheduling algorithm
1827 fselective-scheduling2
1828 Common Report Var(flag_selective_scheduling2) Optimization
1829 Run selective scheduling after reload
1831 fsel-sched-pipelining
1832 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1833 Perform software pipelining of inner loops during selective scheduling
1835 fsel-sched-pipelining-outer-loops
1836 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1837 Perform software pipelining of outer loops during selective scheduling
1839 fsel-sched-reschedule-pipelined
1840 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1841 Reschedule pipelined regions without pipelining
1843 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1844 ; of stalled insns into the ready list.
1845 fsched-stalled-insns
1846 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1847 Allow premature scheduling of queued insns
1849 fsched-stalled-insns=
1850 Common RejectNegative Joined UInteger
1851 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1853 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1854 ; be examined for a dependency on a stalled insn that is candidate for
1855 ; premature removal from the queue of stalled insns into the ready list (has
1856 ; an effect only if the flag 'sched_stalled_insns' is set).
1857 fsched-stalled-insns-dep
1858 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1859 Set dependence distance checking in premature scheduling of queued insns
1861 fsched-stalled-insns-dep=
1862 Common RejectNegative Joined UInteger
1863 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1865 fsched-group-heuristic
1866 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1867 Enable the group heuristic in the scheduler
1869 fsched-critical-path-heuristic
1870 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1871 Enable the critical path heuristic in the scheduler
1873 fsched-spec-insn-heuristic
1874 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1875 Enable the speculative instruction heuristic in the scheduler
1877 fsched-rank-heuristic
1878 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1879 Enable the rank heuristic in the scheduler
1881 fsched-last-insn-heuristic
1882 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1883 Enable the last instruction heuristic in the scheduler
1885 fsched-dep-count-heuristic
1886 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1887 Enable the dependent count heuristic in the scheduler
1890 Common Report Var(flag_section_anchors) Optimization
1891 Access data in the same section from shared anchor points
1895 Does nothing. Preserved for backward compatibility.
1899 Does nothing. Preserved for backward compatibility.
1902 Common Report Var(flag_ree) Init(0)
1903 Turn on Redundant Extensions Elimination pass.
1906 Common Report Var(flag_show_column) Init(1)
1907 Show column numbers in diagnostics, when available. Default on
1910 Common Report Var(flag_shrink_wrap) Optimization
1911 Emit function prologues only before parts of the function that need it,
1912 rather than at the top of the function.
1915 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1916 Disable optimizations observable by IEEE signaling NaNs
1919 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1920 Disable floating point optimizations that ignore the IEEE signedness of zero
1922 fsingle-precision-constant
1923 Common Report Var(flag_single_precision_constant) Optimization
1924 Convert floating point constants to single precision constants
1926 fsplit-ivs-in-unroller
1927 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1928 Split lifetimes of induction variables when loops are unrolled
1931 Common Report Var(flag_split_stack) Init(-1)
1932 Generate discontiguous stack frames
1935 Common Report Var(flag_split_wide_types) Optimization
1936 Split wide types into independent registers
1938 fvariable-expansion-in-unroller
1939 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1940 Apply variable expansion when loops are unrolled
1943 Common Report RejectNegative Joined
1944 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1947 Common Alias(fstack-check=, specific, no)
1948 Insert stack checking code into the program. Same as -fstack-check=specific
1951 Common Var(common_deferred_options) Defer
1953 fstack-limit-register=
1954 Common RejectNegative Joined Var(common_deferred_options) Defer
1955 -fstack-limit-register=<register> Trap if the stack goes past <register>
1957 fstack-limit-symbol=
1958 Common RejectNegative Joined Var(common_deferred_options) Defer
1959 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1962 Common Report Var(flag_stack_protect, 1)
1963 Use propolice as a stack protection method
1965 fstack-protector-all
1966 Common Report RejectNegative Var(flag_stack_protect, 2)
1967 Use a stack protection method for every function
1969 fstack-protector-strong
1970 Common Report RejectNegative Var(flag_stack_protect, 3)
1971 Use a smart stack protection method for certain functions
1974 Common RejectNegative Var(flag_stack_usage)
1975 Output stack usage information on a per-function basis
1979 Does nothing. Preserved for backward compatibility.
1981 ; Nonzero if we should do (language-dependent) alias analysis.
1982 ; Typically, this analysis will assume that expressions of certain
1983 ; types do not alias expressions of certain other types. Only used
1984 ; if alias analysis (in general) is enabled.
1986 Common Report Var(flag_strict_aliasing) Optimization
1987 Assume strict aliasing rules apply
1990 Common Report Var(flag_strict_overflow)
1991 Treat signed overflow as undefined
1994 Common Report Var(flag_sync_libcalls) Init(1)
1995 Implement __atomic operations via libcalls to legacy __sync functions
1998 Common Report Var(flag_syntax_only)
1999 Check for syntax errors, then stop
2002 Common Report Var(flag_test_coverage)
2003 Create data files needed by \"gcov\"
2006 Common Report Var(flag_thread_jumps) Optimization
2007 Perform jump threading optimizations
2010 Common Report Var(time_report)
2011 Report the time taken by each compiler pass
2014 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2015 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
2018 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2021 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2024 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2027 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2030 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2033 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2034 Reorder top level functions, variables, and asms
2037 Common Report Var(flag_tracer)
2038 Perform superblock formation via tail duplication
2040 ; Zero means that floating-point math operations cannot generate a
2041 ; (user-visible) trap. This is the case, for example, in nonstop
2042 ; IEEE 754 arithmetic.
2044 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2045 Assume floating-point operations can trap
2048 Common Report Var(flag_trapv) Optimization
2049 Trap for signed overflow in addition, subtraction and multiplication
2052 Common Report Var(flag_tree_ccp) Optimization
2053 Enable SSA-CCP optimization on trees
2056 Common Report Var(flag_tree_bit_ccp) Optimization
2057 Enable SSA-BIT-CCP optimization on trees
2061 Does nothing. Preserved for backward compatibility.
2064 Common Report Var(flag_tree_ch) Optimization
2065 Enable loop header copying on trees
2067 ftree-coalesce-inlined-vars
2068 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2069 Enable coalescing of copy-related user variables that are inlined
2072 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2073 Enable coalescing of all copy-related user variables
2076 Common Report Var(flag_tree_copyrename) Optimization
2077 Replace SSA temporaries with better names in copies
2080 Common Report Var(flag_tree_copy_prop) Optimization
2081 Enable copy propagation on trees
2083 ftree-store-copy-prop
2085 Does nothing. Preserved for backward compatibility.
2088 Common Report Var(flag_tree_cselim) Init(2) Optimization
2089 Transform condition stores into unconditional ones
2091 ftree-switch-conversion
2092 Common Report Var(flag_tree_switch_conversion) Optimization
2093 Perform conversions of switch initializations.
2096 Common Report Var(flag_tree_dce) Optimization
2097 Enable SSA dead code elimination optimization on trees
2099 ftree-dominator-opts
2100 Common Report Var(flag_tree_dom) Optimization
2101 Enable dominator optimizations
2104 Common Report Var(flag_tree_tail_merge) Optimization
2105 Enable tail merging on trees
2108 Common Report Var(flag_tree_dse) Optimization
2109 Enable dead store elimination
2112 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2113 Enable forward propagation on trees
2116 Common Report Var(flag_tree_fre) Optimization
2117 Enable Full Redundancy Elimination (FRE) on trees
2120 Common Report Var(flag_optimize_strlen) Optimization
2121 Enable string length optimizations on trees
2123 fisolate-erroneous-paths-dereference
2124 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2125 Detect paths which trigger erroneous or undefined behaviour due to
2126 dereferencing a NULL pointer. Isolate those paths from the main control
2127 flow and turn the statement with erroneous or undefined behaviour into a trap.
2129 fisolate-erroneous-paths-attribute
2130 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2131 Detect paths which trigger erroneous or undefined behaviour due a NULL value
2132 being used in a way which is forbidden by a returns_nonnull or nonnull
2133 attribute. Isolate those paths from the main control flow and turn the
2134 statement with erroneous or undefined behaviour into a trap.
2136 ftree-loop-distribution
2137 Common Report Var(flag_tree_loop_distribution) Optimization
2138 Enable loop distribution on trees
2140 ftree-loop-distribute-patterns
2141 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2142 Enable loop distribution for patterns transformed into a library call
2145 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2146 Enable loop invariant motion on trees
2149 Common Alias(floop-interchange)
2150 Enable loop interchange transforms. Same as -floop-interchange
2153 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2154 Create canonical induction variables in loops
2157 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2158 Enable loop optimizations on tree level
2160 ftree-parallelize-loops=
2161 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2162 Enable automatic parallelization of loops
2165 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2166 Enable hoisting loads from conditional pointers.
2169 Common Report Var(flag_tree_pre) Optimization
2170 Enable SSA-PRE optimization on trees
2173 Common Report Var(flag_tree_partial_pre) Optimization
2174 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2177 Common Report Var(flag_tree_pta) Optimization
2178 Perform function-local points-to analysis on trees.
2181 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2182 Enable reassociation on tree level
2186 Does nothing. Preserved for backward compatibility.
2189 Common Report Var(flag_tree_sink) Optimization
2190 Enable SSA code sinking on trees
2193 Common Report Var(flag_tree_slsr) Optimization
2194 Perform straight-line strength reduction
2197 Common Report Var(flag_tree_sra) Optimization
2198 Perform scalar replacement of aggregates
2201 Common Report Var(flag_tree_ter) Optimization
2202 Replace temporary expressions in the SSA->normal pass
2205 Common Report Var(flag_tree_live_range_split) Optimization
2206 Perform live range splitting during the SSA->normal pass
2209 Common Report Var(flag_tree_vrp) Init(0) Optimization
2210 Perform Value Range Propagation on trees
2213 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2214 Compile whole compilation unit at a time
2217 Common Report Var(flag_unroll_loops) Optimization
2218 Perform loop unrolling when iteration count is known
2221 Common Report Var(flag_unroll_all_loops) Optimization
2222 Perform loop unrolling for all loops
2224 ; Nonzero means that loop optimizer may assume that the induction variables
2225 ; that control loops do not overflow and that the loops with nontrivial
2226 ; exit condition are not infinite
2227 funsafe-loop-optimizations
2228 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2229 Allow loop optimizations to assume that the loops behave in normal way
2232 Common Report Var(flag_associative_math) SetByCombined
2233 Allow optimization for floating-point arithmetic which may change the
2234 result of the operation due to rounding.
2237 Common Report Var(flag_reciprocal_math) SetByCombined
2238 Same as -fassociative-math for expressions which include division.
2240 ; Nonzero means that unsafe floating-point math optimizations are allowed
2241 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2242 ; are allowed to assume that their arguments and results are "normal"
2243 ; (e.g., nonnegative for SQRT).
2244 funsafe-math-optimizations
2245 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2246 Allow math optimizations that may violate IEEE or ISO standards
2249 Common Report Var(flag_unswitch_loops) Optimization
2250 Perform loop unswitching
2253 Common Report Var(flag_unwind_tables) Optimization
2254 Just generate unwind tables for exception handling
2257 Common Driver Negative(fuse-ld=gold)
2258 Use the bfd linker instead of the default linker
2261 Common Driver Negative(fuse-ld=bfd)
2262 Use the gold linker instead of the default linker
2265 Common Undocumented Var(flag_use_linker_plugin)
2267 ; Positive if we should track variables, negative if we should run
2268 ; the var-tracking pass only to discard debug annotations, zero if
2269 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2270 ; will be set according to optimize, debug_info_level and debug_hooks
2271 ; in process_options ().
2273 Common Report Var(flag_var_tracking) Init(2) Optimization
2274 Perform variable tracking
2276 ; Positive if we should track variables at assignments, negative if
2277 ; we should run the var-tracking pass only to discard debug
2278 ; annotations. When flag_var_tracking_assignments ==
2279 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2280 fvar-tracking-assignments
2281 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2282 Perform variable tracking by annotating assignments
2284 ; Nonzero if we should toggle flag_var_tracking_assignments after
2285 ; processing options and computing its default. */
2286 fvar-tracking-assignments-toggle
2287 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2288 Toggle -fvar-tracking-assignments
2290 ; Positive if we should track uninitialized variables, negative if
2291 ; we should run the var-tracking pass only to discard debug
2292 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2293 ; will be set according to flag_var_tracking.
2294 fvar-tracking-uninit
2295 Common Report Var(flag_var_tracking_uninit) Optimization
2296 Perform variable tracking and also tag variables that are uninitialized
2299 Common Report Var(flag_tree_vectorize) Optimization
2300 Enable vectorization on trees
2302 ftree-vectorizer-verbose=
2303 Common Joined RejectNegative Ignore
2304 Does nothing. Preserved for backward compatibility.
2306 ftree-loop-vectorize
2307 Common Report Var(flag_tree_loop_vectorize) Optimization
2308 Enable loop vectorization on trees
2311 Common Report Var(flag_tree_slp_vectorize) Optimization
2312 Enable basic block vectorization (SLP) on trees
2315 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT)
2316 Specifies the cost model for vectorization
2319 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED)
2320 Specifies the vectorization cost model for code marked with a simd directive
2323 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2326 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2329 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2332 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2335 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2336 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2339 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2340 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2342 ftree-vect-loop-version
2344 Does nothing. Preserved for backward compatibility.
2347 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2348 Enable copy propagation of scalar-evolution information.
2350 ; -fverbose-asm causes extra commentary information to be produced in
2351 ; the generated assembly code (to make it more readable). This option
2352 ; is generally only of use to those who actually need to read the
2353 ; generated assembly code (perhaps while debugging the compiler itself).
2354 ; -fno-verbose-asm, the default, causes the extra information
2355 ; to not be added and is useful when comparing two assembler files.
2357 Common Report Var(flag_verbose_asm)
2358 Add extra commentary to assembler output
2361 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2362 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2365 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2368 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2371 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2374 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2377 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2380 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2381 Validate vtable pointers before using them.
2384 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2387 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2390 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2393 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2396 Common Var(flag_vtv_counts)
2397 Output vtable verification counters.
2400 Common Var(flag_vtv_debug)
2401 Output vtable verification pointer sets information.
2404 Common Report Var(flag_value_profile_transformations) Optimization
2405 Use expression value profiles in optimizations
2408 Common Report Var(flag_web) Init(2) Optimization
2409 Construct webs and split unrelated uses of single variable
2411 ftree-builtin-call-dce
2412 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2413 Enable conditional dead code elimination for builtin calls
2416 Common Report Var(flag_whole_program) Init(0) Optimization
2417 Perform whole program optimizations
2420 Common Report Var(flag_wrapv) Optimization
2421 Assume signed arithmetic overflow wraps around
2423 fzero-initialized-in-bss
2424 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2425 Put zero initialized data in the bss section
2428 Common JoinedOrMissing
2429 Generate debug information in default format
2432 Common JoinedOrMissing Negative(gdwarf)
2433 Generate debug information in COFF format
2436 Common JoinedOrMissing Negative(gdwarf-)
2437 Generate debug information in default version of DWARF format
2440 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2441 Generate debug information in DWARF v2 (or later) format
2444 Common JoinedOrMissing
2445 Generate debug information in default extended format
2448 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2449 Don't generate DWARF pubnames and pubtypes sections.
2452 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2453 Generate DWARF pubnames and pubtypes sections.
2456 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2457 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2459 gno-record-gcc-switches
2460 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2461 Don't record gcc command line switches in DWARF DW_AT_producer.
2463 grecord-gcc-switches
2464 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2465 Record gcc command line switches in DWARF DW_AT_producer.
2468 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2469 Don't generate debug information in separate .dwo files
2472 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2473 Generate debug information in separate .dwo files
2476 Common JoinedOrMissing Negative(gstabs+)
2477 Generate debug information in STABS format
2480 Common JoinedOrMissing Negative(gvms)
2481 Generate debug information in extended STABS format
2484 Common RejectNegative Var(dwarf_strict,0) Init(0)
2485 Emit DWARF additions beyond selected version
2488 Common Report RejectNegative Var(dwarf_strict,1)
2489 Don't emit DWARF additions beyond selected version
2492 Common Report Var(flag_gtoggle)
2493 Toggle debug information generation
2496 Common JoinedOrMissing Negative(gxcoff)
2497 Generate debug information in VMS format
2500 Common JoinedOrMissing Negative(gxcoff+)
2501 Generate debug information in XCOFF format
2504 Common JoinedOrMissing Negative(gcoff)
2505 Generate debug information in extended XCOFF format
2508 Driver Joined Separate
2511 Common Joined Var(plugindir_string) Init(0)
2512 -iplugindir=<dir> Set <dir> to be the default plugin directory
2515 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2516 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2519 Driver Joined Separate
2524 no-canonical-prefixes
2537 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2538 -o <file> Place output into <file>
2541 Common Var(profile_flag)
2542 Enable function profiling
2545 Driver Var(pass_exit_codes)
2548 Common Alias(Wpedantic)
2551 Common Var(flag_pedantic_errors)
2552 Like -pedantic but issue them as errors
2558 Driver Var(use_pipes)
2561 Driver JoinedOrMissing Var(print_file_name)
2563 print-libgcc-file-name
2566 print-multi-directory
2567 Driver Var(print_multi_directory)
2570 Driver Var(print_multi_lib)
2572 print-multi-os-directory
2573 Driver Var(print_multi_os_directory)
2576 Driver Var(print_multiarch)
2579 Driver JoinedOrMissing Var(print_prog_name)
2582 Driver Var(print_search_dirs)
2585 Driver Var(print_sysroot)
2587 print-sysroot-headers-suffix
2588 Driver Var(print_sysroot_headers_suffix)
2591 Common Var(quiet_flag) RejectDriver
2592 Do not display functions compiled or elapsed time
2610 Driver Var(report_times)
2613 Driver JoinedOrMissing
2616 Driver Joined Separate
2620 ; C option, but driver must not handle as "-u ndef".
2623 Common Driver Var(verbose_flag)
2624 Enable verbose output
2627 Common Var(version_flag) RejectDriver
2628 Display the compiler's version
2631 Common Var(inhibit_warnings)
2635 Driver Separate Var(wrapper_string)
2638 Driver Joined Separate
2641 Driver RejectNegative Negative(pie)
2642 Create a shared library
2648 Driver Separate Alias(specs=)
2661 ; Documented for Fortran, but always accepted by driver.
2668 ; Documented for Go, but always accepted by driver.
2686 Driver RejectNegative Negative(shared)
2687 Create a position independent executable
2690 Driver Joined Separate
2692 ; This comment is to ensure we retain the blank line above.