1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2017 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 ; This variable is set to non-0 only by LTO front-end. 1 indicates that
50 ; the output produced will be used for incrmeental linking (thus weak symbols
51 ; can still be bound).
53 int flag_incremental_link = 0
55 ; 0 means straightforward implementation of complex divide acceptable.
56 ; 1 means wide ranges of inputs must work for complex divide.
57 ; 2 means C99-like requirements for complex multiply and divide.
59 int flag_complex_method = 1
61 ; Language specific warning pass for unused results.
63 bool flag_warn_unused_result = false
68 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
72 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
74 int flag_generate_offload = 0
76 ; True to warn about any objects definitions whose size is larger
77 ; than N bytes. Also want about function definitions whose returned
78 ; values are larger than N bytes, where N is 'larger_than_size'.
83 HOST_WIDE_INT larger_than_size
85 ; True to warn about any function whose frame size is larger
88 bool warn_frame_larger_than
91 HOST_WIDE_INT frame_larger_than_size
93 ; Nonzero means we should be saving declaration info into a .X file.
95 int flag_gen_aux_info = 0
97 ; Nonzero if we are compiling code for a shared library, zero for
102 ; These two are really VEC(char_p,heap) *.
105 void *flag_instrument_functions_exclude_functions
108 void *flag_instrument_functions_exclude_files
110 ; Generic structs (e.g. templates not explicitly specialized)
111 ; may not have a compilation unit associated with them, and so
112 ; may need to be treated differently from ordinary structs.
114 ; Structs only handled by reference (indirectly), will also usually
115 ; not need as much debugging information.
118 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
121 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
123 ; True if we should exit after parsing options.
125 bool exit_after_options
127 ; Type(s) of debugging information we are producing (if any). See
128 ; flag-types.h for the definitions of the different possible types of
129 ; debugging information.
131 enum debug_info_type write_symbols = NO_DEBUG
133 ; Level of debugging information we are producing. See flag-types.h
134 ; for the definitions of the different possible levels.
136 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
138 ; Nonzero means use GNU-only extensions in the generated symbolic
139 ; debugging information. Currently, this only has an effect when
140 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
142 bool use_gnu_debug_info_extensions
144 ; Original value of maximum field alignment in bytes, specified via
145 ; -fpack-struct=<value>.
147 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
149 ; Type of stack check.
151 enum stack_check_type flag_stack_check = NO_STACK_CHECK
153 ; True if stack usage information needs to be computed.
155 bool flag_stack_usage_info = false
157 ; -dA causes debug commentary information to be produced in
158 ; the generated assembly code (to make it more readable). This option
159 ; is generally only of use to those who actually need to read the
160 ; generated assembly code (perhaps while debugging the compiler itself).
161 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
162 ; to be a catchall for printing debug information in the assembler file.
166 ; How many NOP insns to place at each function entry by default
168 HOST_WIDE_INT function_entry_patch_area_size
170 ; And how far the real asm entry point is into this area
172 HOST_WIDE_INT function_entry_patch_area_start
174 ; Balance between GNAT encodings and standard DWARF to emit.
176 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
178 ; -dP causes the rtl to be emitted as a comment in assembly.
180 int flag_dump_rtl_in_asm
182 ; Whether -da was passed (used only in handle_common_deferred_options).
184 bool flag_dump_all_passed
186 ; Other flags saying which kinds of debugging dump have been requested.
189 int rtl_dump_and_exit
192 int flag_print_asm_name
194 ; Name of top-level original source file (what was input to cpp).
195 ; This comes from the #-command at the beginning of the actual input.
196 ; If there isn't any there, then this is the cc1 input file name.
198 const char *main_input_filename
200 ; Pointer to base name in main_input_filename, with directories and a
201 ; single final extension removed, and the length of this base
205 const char *main_input_basename
208 int main_input_baselength
210 ; Which options have been printed by --help.
214 ; Which enums have been printed by --help. 0 = not printed, no
215 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
218 char *help_enum_printed
220 ; The number of columns for --help output.
222 unsigned int help_columns
224 ; Whether this options structure has been through finish_options
226 bool flag_opts_finished
228 ; What the sanitizer should instrument
230 unsigned int flag_sanitize
232 ; What sanitizers should recover from errors
234 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
236 ; What the coverage sanitizers should instrument
238 unsigned int flag_sanitize_coverage
240 ; Flag whether a prefix has been added to dump_base_name
242 bool dump_base_name_prefixed = false
244 ; Flag whether HSA generation has been explicitely disabled
246 bool flag_disable_hsa = false
258 Driver Alias(coverage)
264 Common Separate Alias(d)
267 Common Joined Alias(d)
270 Common Separate Alias(dumpbase)
273 Common Separate Alias(dumpdir)
276 Driver Separate Alias(e)
279 Driver Joined Alias(e)
282 Common Warning Alias(Wextra)
285 Driver Separate Alias(Xassembler)
288 Driver JoinedOrMissing Alias(Xassembler)
291 Driver Separate Alias(Xlinker)
294 Driver JoinedOrMissing Alias(Xlinker)
297 Driver Separate Alias(u)
300 Driver Joined Alias(u)
303 Common Driver Var(help_flag)
304 Display this information.
307 Common Driver Report Joined
308 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
311 Driver Separate Alias(x)
314 Driver Joined Alias(x)
317 Driver Separate Alias(L)
320 Driver Joined Alias(L)
322 -no-canonical-prefixes
323 Driver Alias(no-canonical-prefixes)
325 -no-standard-libraries
326 Driver Alias(nostdlib)
329 Driver Var(no_sysroot_suffix)
338 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
341 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
344 Driver Alias(pass-exit-codes)
347 Common Alias(Wpedantic)
350 Common Alias(pedantic-errors)
356 Driver Alias(static-pie)
362 Driver Separate Alias(B)
365 Driver JoinedOrMissing Alias(B)
371 Driver Separate Alias(print-file-name=)
374 Driver JoinedOrMissing Alias(print-file-name=)
376 -print-libgcc-file-name
377 Driver Alias(print-libgcc-file-name)
379 -print-multi-directory
380 Driver Alias(print-multi-directory)
383 Driver Alias(print-multi-lib)
385 -print-multi-os-directory
386 Driver Alias(print-multi-os-directory)
389 Driver Alias(print-multiarch)
392 Driver Separate Alias(print-prog-name=)
395 Driver JoinedOrMissing Alias(print-prog-name=)
398 Driver Alias(print-search-dirs)
401 Driver Alias(print-sysroot)
403 -print-sysroot-headers-suffix
404 Driver Alias(print-sysroot-headers-suffix)
410 Driver Alias(save-temps)
416 Driver Separate Alias(specs=)
419 Driver Joined Alias(specs=)
425 Driver Alias(symbolic)
429 Alias for --help=target.
437 ;; The driver used to convert options such as --help into forms such
438 ;; as -fhelp; the following four entries are for compatibility with
439 ;; any direct uses of those (undocumented) -f forms
441 Common Driver Alias(-help)
444 Common Driver Joined Alias(-help=)
447 Common Driver Alias(-target-help)
450 Common Driver Alias(-version)
454 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
457 Common Joined Alias(-param)
460 Driver Separate Alias(-sysroot=)
463 Driver JoinedOrMissing
469 Driver Joined Separate
475 Driver Joined Separate
481 Common JoinedOrMissing Optimization
482 -O<number> Set optimization level to <number>.
486 Optimize for space rather than speed.
490 Optimize for speed disregarding exact standards compliance.
494 Optimize for debugging experience rather than speed or size.
506 Driver Joined Separate
512 Driver Joined Separate
533 Common RejectNegative Warning Alias(Wextra)
534 This switch is deprecated; use -Wextra instead.
537 Driver JoinedOrMissing RejectNegative
540 Driver JoinedOrMissing RejectNegative
543 Driver JoinedOrMissing RejectNegative
546 Common Var(warn_aggregate_return) Warning
547 Warn about returning structures, unions or arrays.
549 Waggressive-loop-optimizations
550 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
551 Warn if a loop with constant number of iterations triggers undefined behavior.
554 Common Var(warn_array_bounds) Warning
555 Warn if an array is accessed out of bounds.
558 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
559 Warn if an array is accessed out of bounds.
562 Common Var(warn_attributes) Init(1) Warning
563 Warn about inappropriate attribute usage.
566 Common Var(warn_attributes) Init(1) Warning
567 Warn about type safety and similar errors in attribute alias and related.
570 Common Var(warn_cast_align) Warning
571 Warn about pointer casts which increase alignment.
574 Common Var(warn_cast_align,2) Warning
575 Warn about pointer casts which increase alignment.
578 Common Var(warn_cpp) Init(1) Warning
579 Warn when a #warning directive is encountered.
581 Wdeprecated-declarations
582 Common Var(warn_deprecated_decl) Init(1) Warning
583 Warn about uses of __attribute__((deprecated)) declarations.
585 Wdisabled-optimization
586 Common Var(warn_disabled_optimization) Warning
587 Warn when an optimization pass is disabled.
590 Common Var(warnings_are_errors)
591 Treat all warnings as errors.
595 Treat specified warning as error.
598 Common Var(extra_warnings) Warning
599 Print extra (possibly unwanted) warnings.
602 Common Var(flag_fatal_errors)
603 Exit on the first error occurred.
606 Common RejectNegative Joined UInteger Warning
607 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes.
610 Common Var(warn_free_nonheap_object) Init(1) Warning
611 Warn when attempting to free a non-heap object.
614 Common Var(warn_hsa) Init(1) Warning
615 Warn when a function cannot be expanded to HSAIL.
617 Wimplicit-fallthrough
618 Common Alias(Wimplicit-fallthrough=,3,0) Warning
620 Wimplicit-fallthrough=
621 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
622 Warn when a switch case falls through.
625 Common Var(warn_inline) Warning
626 Warn when an inlined function cannot be inlined.
628 Winvalid-memory-model
629 Common Var(warn_invalid_memory_model) Init(1) Warning
630 Warn when an atomic memory model parameter is known to be outside the valid range.
633 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
636 Common RejectNegative Joined UInteger Warning
637 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
640 Var(warn_nonnull_compare) Warning
641 Warn if comparing pointer parameter with nonnull attribute with NULL.
644 Common Var(warn_null_dereference) Warning
645 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
647 Wunsafe-loop-optimizations
648 Common Var(warn_unsafe_loop_optimizations) Warning
649 Warn if the loop cannot be optimized due to nontrivial assumptions.
652 Common Warning Alias(Wsuggest-attribute=noreturn)
655 Common Var(warn_odr_violations) Init(1) Warning
656 Warn about some C++ One Definition Rule violations during link time optimization.
659 Common Var(warn_overflow) Init(1) Warning
660 Warn about overflow in arithmetic expressions.
663 Common Var(warn_lto_type_mismatch) Init(1) Warning
664 During link time optimization warn about mismatched types of global declarations.
667 Common Var(warn_packed) Warning
668 Warn when the packed attribute has no effect on struct layout.
671 Common Var(warn_padded) Warning
672 Warn when padding is required to align structure members.
675 Common Var(pedantic) Init(0) Warning
676 Issue warnings needed for strict compliance to the standard.
679 Common Var(warn_return_local_addr) Init(1) Warning
680 Warn about returning a pointer/reference to a local or temporary variable.
683 Common Var(warn_shadow) Warning
684 Warn when one variable shadows another. Same as -Wshadow=global.
687 Common Warning Alias(Wshadow)
688 Warn when one variable shadows another (globally).
691 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
692 Warn when one local variable shadows another local variable or parameter.
695 Common Warning Undocumented Alias(Wshadow=local)
697 Wshadow=compatible-local
698 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
699 Warn when one local variable shadows another local variable or parameter of compatible type.
701 Wshadow-compatible-local
702 Common Warning Undocumented Alias(Wshadow=compatible-local)
705 Common Var(warn_stack_protect) Warning
706 Warn when not issuing stack smashing protection for some reason.
709 Common Joined RejectNegative UInteger Var(warn_stack_usage) Warning
710 -Wstack-usage=<number> Warn if stack usage might be larger than specified amount.
714 Warn about code which might break strict aliasing rules.
717 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
718 Warn about code which might break strict aliasing rules.
722 Warn about optimizations that assume that signed overflow is undefined.
725 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
726 Warn about optimizations that assume that signed overflow is undefined.
728 Wsuggest-attribute=cold
729 Common Var(warn_suggest_attribute_cold) Warning
730 Warn about functions which might be candidates for __attribute__((cold)).
732 Wsuggest-attribute=const
733 Common Var(warn_suggest_attribute_const) Warning
734 Warn about functions which might be candidates for __attribute__((const)).
736 Wsuggest-attribute=pure
737 Common Var(warn_suggest_attribute_pure) Warning
738 Warn about functions which might be candidates for __attribute__((pure)).
740 Wsuggest-attribute=noreturn
741 Common Var(warn_suggest_attribute_noreturn) Warning
742 Warn about functions which might be candidates for __attribute__((noreturn)).
744 Wsuggest-attribute=malloc
745 Common Var(warn_suggest_attribute_malloc) Warning
746 Warn about functions which might be candidates for __attribute__((malloc)).
749 Common Var(warn_suggest_final_types) Warning
750 Warn about C++ polymorphic types where adding final keyword would improve code quality.
752 Wsuggest-final-methods
753 Common Var(warn_suggest_final_methods) Warning
754 Warn about C++ virtual methods where adding final keyword would improve code quality.
757 Common Var(warn_switch_unreachable) Warning Init(1)
758 Warn about statements between switch's controlling expression and the first
762 Common Var(warn_system_headers) Warning
763 Do not suppress warnings from system headers.
766 Common Var(warn_trampolines) Warning
767 Warn whenever a trampoline is generated.
770 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
771 Warn if a comparison is always true or always false due to the limited range of the data type.
774 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
775 Warn about uninitialized automatic variables.
778 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
779 Warn about maybe uninitialized automatic variables.
782 Common Ignore Warning
783 Does nothing. Preserved for backward compatibility.
786 Common Var(warn_unused) Init(0) Warning
787 Enable all -Wunused- warnings.
789 Wunused-but-set-parameter
790 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
791 Warn when a function parameter is only set, otherwise unused.
793 Wunused-but-set-variable
794 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
795 Warn when a variable is only set, otherwise unused.
798 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
799 Warn when a function is unused.
802 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
803 Warn when a label is unused.
806 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
807 Warn when a function parameter is unused.
810 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
811 Warn when an expression value is unused.
814 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
815 Warn when a variable is unused.
818 Common Var(warn_coverage_mismatch) Init(1) Warning
819 Warn in case profiles in -fprofile-use do not match.
821 Wvector-operation-performance
822 Common Var(warn_vector_operation_performance) Warning
823 Warn when a vector operation is compiled outside the SIMD.
838 Common Separate Var(aux_info_file_name)
839 -aux-info <file> Emit declaration information into <file>.
842 Common Joined Alias(aux-info)
845 Common Separate RejectDriver Var(aux_base_name)
848 Common Separate RejectDriver
858 -d<letters> Enable dumps from specific passes of the compiler.
861 Common Separate Var(dump_base_name)
862 -dumpbase <file> Set the file basename to be used for dumps.
865 Common Separate Var(dump_dir_name)
866 -dumpdir <dir> Set the directory name to be used for dumps.
881 Driver Joined Separate
883 ; This option has historically been passed down to the linker by an
884 ; accident of a %{e*} spec, so ensure it continues to be passed down
885 ; as a single option. The supported option for this purpose is
886 ; -rdynamic. See PR 47390.
890 ; The version of the C++ ABI in use. The following values are allowed:
892 ; 0: The version of the ABI believed most conformant with the C++ ABI
893 ; specification. This ABI may change as bugs are discovered and fixed.
894 ; Therefore, 0 will not necessarily indicate the same ABI in different
897 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
899 ; 2: The version of the ABI first used in G++ 3.4, and the default
902 ; 3: The version of the ABI that fixes the missing underscore
903 ; in template non-type arguments of pointer type.
905 ; 4: The version of the ABI that introduces unambiguous mangling of
906 ; vector types. First selectable in G++ 4.5.
908 ; 5: The version of the ABI that ignores attribute const/noreturn
909 ; in function pointer mangling, and corrects mangling of decltype and
910 ; function parameters used in other parameters and the return type.
911 ; First selectable in G++ 4.6.
913 ; 6: The version of the ABI that doesn't promote scoped enums to int and
914 ; changes the mangling of template argument packs, const/static_cast,
915 ; prefix ++ and --, and a class scope function used as a template
917 ; First selectable in G++ 4.7.
919 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
920 ; corrects the mangling of lambdas in default argument scope.
921 ; First selectable in G++ 4.8.
923 ; 8: The version of the ABI that corrects the substitution behavior of
924 ; function types with function-cv-qualifiers.
925 ; First selectable in G++ 4.9 and default in G++ 5.
927 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
928 ; First selectable and default in G++ 5.2.
930 ; 10: The version of the ABI that mangles attributes that affect type
931 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
932 ; Default in G++ 6 (set in c_common_post_options).
934 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
935 ; and introduces new inheriting constructor handling.
938 ; 12: Corrects the calling convention for classes with only deleted copy/move
939 ; constructors and changes passing/returning of empty records.
942 ; Additional positive integers will be assigned as new versions of
943 ; the ABI become the default version of the ABI.
945 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
946 The version of the C++ ABI in use.
948 faggressive-loop-optimizations
949 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
950 Aggressively optimize loops using language constraints.
953 Common Report Var(align_functions,0) Optimization UInteger
954 Align the start of functions.
957 Common RejectNegative Joined UInteger Var(align_functions)
959 flimit-function-alignment
960 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
963 Common Report Var(align_jumps,0) Optimization UInteger
964 Align labels which are only reached by jumping.
967 Common RejectNegative Joined UInteger Var(align_jumps)
970 Common Report Var(align_labels,0) Optimization UInteger
974 Common RejectNegative Joined UInteger Var(align_labels)
977 Common Report Var(align_loops,0) Optimization UInteger
978 Align the start of loops.
981 Common RejectNegative Joined UInteger Var(align_loops)
985 Does nothing. Preserved for backward compatibility.
989 Does nothing. Preserved for backward compatibility.
991 fargument-noalias-global
993 Does nothing. Preserved for backward compatibility.
995 fargument-noalias-anything
997 Does nothing. Preserved for backward compatibility.
1000 Common Driver Report Joined
1001 Select what to sanitize.
1004 Common Report Joined
1005 Select what to coverage sanitize.
1007 fasan-shadow-offset=
1008 Common Joined RejectNegative Var(common_deferred_options) Defer
1009 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1012 Common Joined RejectNegative Var(common_deferred_options) Defer
1013 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1014 in user-defined sections.
1017 Common Report Joined
1018 After diagnosing undefined behavior attempt to continue execution.
1022 This switch is deprecated; use -fsanitize-recover= instead.
1024 fsanitize-address-use-after-scope
1025 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1027 fsanitize-undefined-trap-on-error
1028 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1029 Use trap instead of a library function for undefined behavior sanitization.
1031 fasynchronous-unwind-tables
1032 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1033 Generate unwind tables that are exact at each instruction boundary.
1036 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1037 Generate auto-inc/dec instructions.
1040 Common Report Var(flag_auto_profile)
1041 Use sample profile information for call graph node weights. The default
1042 profile file is fbdata.afdo in 'pwd'.
1045 Common Joined RejectNegative Var(auto_profile_file)
1046 Use sample profile information for call graph node weights. The profile
1047 file is specified in the argument.
1049 ; -fcheck-bounds causes gcc to generate array bounds checks.
1050 ; For C, C++ and ObjC: defaults off.
1051 ; For Java: defaults to on.
1052 ; For Fortran: defaults to off.
1054 Common Report Var(flag_bounds_check)
1055 Generate code to check bounds before indexing arrays.
1058 Common Report Var(flag_branch_on_count_reg) Optimization
1059 Replace add, compare, branch with branch on count register.
1061 fbranch-probabilities
1062 Common Report Var(flag_branch_probabilities) Optimization
1063 Use profiling information for branch probabilities.
1065 fbranch-target-load-optimize
1066 Common Report Var(flag_branch_target_load_optimize) Optimization
1067 Perform branch target load optimization before prologue / epilogue threading.
1069 fbranch-target-load-optimize2
1070 Common Report Var(flag_branch_target_load_optimize2) Optimization
1071 Perform branch target load optimization after prologue / epilogue threading.
1074 Common Report Var(flag_btr_bb_exclusive) Optimization
1075 Restrict target load migration not to re-use registers in any basic block.
1078 Common Joined RejectNegative Var(common_deferred_options) Defer
1079 -fcall-saved-<register> Mark <register> as being preserved across functions.
1082 Common Joined RejectNegative Var(common_deferred_options) Defer
1083 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1085 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1086 ; be saved across function calls, if that produces overall better code.
1087 ; Optional now, so people can test it.
1089 Common Report Var(flag_caller_saves) Optimization
1090 Save registers around function calls.
1093 Common Report Var(flag_check_data_deps)
1094 This switch is deprecated; do not use.
1097 Common Var(flag_check_new)
1098 Check the return value of new in C++.
1101 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1102 Perform internal consistency checkings.
1105 Common Joined RejectNegative UInteger Var(flag_checking)
1106 Perform internal consistency checkings.
1109 Common Report Var(flag_code_hoisting) Optimization
1110 Enable code hoisting.
1112 fcombine-stack-adjustments
1113 Common Report Var(flag_combine_stack_adjustments) Optimization
1114 Looks for opportunities to reduce stack adjustments and stack references.
1117 Common Report Var(flag_no_common,0)
1118 Do not put uninitialized globals in the common section.
1122 ; Converted by the driver to -fcompare-debug= options.
1125 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1126 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1128 fcompare-debug-second
1129 Common Driver RejectNegative Var(flag_compare_debug)
1130 Run only the second compilation of -fcompare-debug.
1133 Common Report Var(flag_compare_elim_after_reload) Optimization
1134 Perform comparison elimination after register allocation has finished.
1137 Common Var(flag_conserve_stack) Optimization
1138 Do not perform optimizations increasing noticeably stack usage.
1141 Common Report Var(flag_cprop_registers) Optimization
1142 Perform a register copy-propagation optimization pass.
1145 Common Report Var(flag_crossjumping) Optimization
1146 Perform cross-jumping optimization.
1149 Common Report Var(flag_cse_follow_jumps) Optimization
1150 When running CSE, follow jumps to their targets.
1154 Does nothing. Preserved for backward compatibility.
1157 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1158 Omit range reduction step when performing complex division.
1161 Common Report Var(flag_cx_fortran_rules) Optimization
1162 Complex multiplication and division follow Fortran rules.
1165 Common Report Var(flag_data_sections)
1166 Place data items into their own section.
1169 Common Report Var(common_deferred_options) Defer
1170 List all available debugging counters with their limits and counts.
1173 Common RejectNegative Joined Var(common_deferred_options) Defer
1174 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1177 Common Joined RejectNegative Var(common_deferred_options) Defer
1178 Map one directory name to another in debug information.
1180 fdebug-types-section
1181 Common Report Var(flag_debug_types_section) Init(0)
1182 Output .debug_types section when using DWARF v4 debuginfo.
1184 ; Nonzero for -fdefer-pop: don't pop args after each function call
1185 ; instead save them up to pop many calls' args with one insns.
1187 Common Report Var(flag_defer_pop) Optimization
1188 Defer popping functions args from stack until later.
1191 Common Report Var(flag_delayed_branch) Optimization
1192 Attempt to fill delay slots of branch instructions.
1194 fdelete-dead-exceptions
1195 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1196 Delete dead instructions that may throw exceptions.
1198 fdelete-null-pointer-checks
1199 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1200 Delete useless null pointer checks.
1202 fdevirtualize-at-ltrans
1203 Common Report Var(flag_ltrans_devirtualize)
1204 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1206 fdevirtualize-speculatively
1207 Common Report Var(flag_devirtualize_speculatively) Optimization
1208 Perform speculative devirtualization.
1211 Common Report Var(flag_devirtualize) Optimization
1212 Try to convert virtual calls to direct ones.
1214 fdiagnostics-show-location=
1215 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1216 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1218 ; Required for these enum values.
1223 Name(diagnostic_prefixing_rule) Type(int)
1226 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1229 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1231 fdiagnostics-show-caret
1232 Common Var(flag_diagnostics_show_caret) Init(1)
1233 Show the source line with a caret indicating the column.
1236 Common Alias(fdiagnostics-color=,always,never)
1240 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1241 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1243 ; Required for these enum values.
1248 Name(diagnostic_color_rule) Type(int)
1251 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1254 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1257 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1259 fdiagnostics-parseable-fixits
1260 Common Var(flag_diagnostics_parseable_fixits)
1261 Print fix-it hints in machine-readable form.
1263 fdiagnostics-generate-patch
1264 Common Var(flag_diagnostics_generate_patch)
1265 Print fix-it hints to stderr in unified diff format.
1267 fdiagnostics-show-option
1268 Common Var(flag_diagnostics_show_option) Init(1)
1269 Amend appropriate diagnostic messages with the command line option that controls them.
1272 Common Joined RejectNegative Var(common_deferred_options) Defer
1273 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1276 Common Joined RejectNegative Var(common_deferred_options) Defer
1277 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1280 Common Joined RejectNegative Var(common_deferred_options) Defer
1281 -fdump-<type> Dump various compiler internals to a file.
1284 Driver RejectNegative
1287 Common RejectNegative Joined Var(flag_dump_final_insns)
1288 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1291 Common RejectNegative Joined Var(flag_dump_go_spec)
1292 -fdump-go-spec=filename Write all declarations to file as Go code.
1295 Common Report Var(flag_dump_noaddr)
1296 Suppress output of addresses in debugging dumps.
1299 Common Driver Var(flag_report_bug)
1300 Collect and dump debug information into temporary file if ICE in C/C++
1303 fdump-internal-locations
1304 Common Var(flag_dump_locations) Init(0)
1305 Dump detailed information on GCC's internal representation of source code locations.
1308 Common Var(flag_dump_passes) Init(0)
1309 Dump optimization passes.
1312 Common Report Var(flag_dump_unnumbered)
1313 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1315 fdump-unnumbered-links
1316 Common Report Var(flag_dump_unnumbered_links)
1317 Suppress output of previous and next insn numbers in debugging dumps.
1320 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1321 Enable CFI tables via GAS assembler directives.
1324 Common Report Var(flag_early_inlining) Init(1) Optimization
1325 Perform early inlining.
1327 feliminate-dwarf2-dups
1329 Does nothing. Preserved for backward compatibility.
1332 Common Report Var(flag_ipa_sra) Init(0) Optimization
1333 Perform interprocedural reduction of aggregates.
1335 feliminate-unused-debug-symbols
1336 Common Report Var(flag_debug_only_used_symbols)
1337 Perform unused symbol elimination in debug info.
1339 feliminate-unused-debug-types
1340 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1341 Perform unused type elimination in debug info.
1343 femit-class-debug-always
1344 Common Report Var(flag_emit_class_debug_always) Init(0)
1345 Do not suppress C++ class debug information.
1348 Common Report Var(flag_exceptions) Optimization
1349 Enable exception handling.
1351 fexpensive-optimizations
1352 Common Report Var(flag_expensive_optimizations) Optimization
1353 Perform a number of minor, expensive optimizations.
1356 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1357 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1360 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1363 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1366 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1368 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1369 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1370 fpermitted-flt-eval-methods=
1371 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1372 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1375 Name(permitted_flt_eval_methods) Type(enum permitted_flt_eval_methods) UnknownError(unknown specification for the set of FLT_EVAL_METHOD values to permit %qs)
1378 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1381 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1387 Common Var(flag_fat_lto_objects)
1388 Output lto objects containing both the intermediate language and binary output.
1391 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1392 Assume no NaNs or infinities are generated.
1395 Common Joined RejectNegative Var(common_deferred_options) Defer
1396 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1399 Common Report Var(flag_float_store) Optimization
1400 Don't allocate floats and doubles in extended-precision registers.
1404 Does nothing. Preserved for backward compatibility.
1407 Common Report Var(flag_forward_propagate) Optimization
1408 Perform a forward propagation pass on RTL.
1411 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1412 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1415 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1418 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1420 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1422 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1425 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1427 ffp-int-builtin-inexact
1428 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1429 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1431 ; Nonzero means don't put addresses of constant functions in registers.
1432 ; Used for compiling the Unix kernel, where strange substitutions are
1433 ; done on the assembly output.
1435 Common Report Var(flag_no_function_cse,0) Optimization
1436 Allow function addresses to be held in registers.
1439 Common Report Var(flag_function_sections)
1440 Place each function into its own section.
1443 Common Report Var(flag_gcse) Optimization
1444 Perform global common subexpression elimination.
1447 Common Report Var(flag_gcse_lm) Init(1) Optimization
1448 Perform enhanced load motion during global common subexpression elimination.
1451 Common Report Var(flag_gcse_sm) Init(0) Optimization
1452 Perform store motion after global common subexpression elimination.
1455 Common Report Var(flag_gcse_las) Init(0) Optimization
1456 Perform redundant load after store elimination in global common subexpression
1460 Common Report Var(flag_gcse_after_reload) Optimization
1461 Perform global common subexpression elimination after register allocation has
1465 Name(dwarf_gnat_encodings) Type(int)
1468 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1471 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1474 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1477 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1478 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1480 ; This option is not documented yet as its semantics will change.
1482 Common Report Var(flag_graphite) Optimization
1483 Enable in and out of Graphite representation.
1486 Common Report Var(flag_graphite_identity) Optimization
1487 Enable Graphite Identity transformation.
1489 fhoist-adjacent-loads
1490 Common Report Var(flag_hoist_adjacent_loads) Optimization
1491 Enable hoisting adjacent loads to encourage generating conditional move
1495 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1496 ; Always keep a pointer to a live memory block
1498 floop-parallelize-all
1499 Common Report Var(flag_loop_parallelize_all) Optimization
1500 Mark all loops as parallel.
1503 Common Alias(floop-nest-optimize)
1504 Enable loop nest transforms. Same as -floop-nest-optimize.
1507 Common Alias(floop-nest-optimize)
1508 Enable loop nest transforms. Same as -floop-nest-optimize.
1511 Common Alias(floop-nest-optimize)
1512 Enable loop nest transforms. Same as -floop-nest-optimize.
1514 floop-unroll-and-jam
1515 Common Alias(floop-nest-optimize)
1516 Enable loop nest transforms. Same as -floop-nest-optimize.
1519 Common Report Var(flag_tm)
1520 Enable support for GNU transactional memory.
1523 Common Report Var(flag_gnu_unique) Init(1)
1524 Use STB_GNU_UNIQUE if supported by the assembler.
1528 Does nothing. Preserved for backward compatibility.
1531 Common Report Var(flag_loop_nest_optimize) Optimization
1532 Enable the loop nest optimizer.
1534 fstrict-volatile-bitfields
1535 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1536 Force bitfield accesses to match their type width.
1539 Common Report Var(flag_store_merging) Optimization
1540 Merge adjacent stores.
1542 fguess-branch-probability
1543 Common Report Var(flag_guess_branch_prob) Optimization
1544 Enable guessing of branch probabilities.
1546 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1547 ; Generate position-independent code for executables if possible
1548 ; On SVR4 targets, it also controls whether or not to emit a
1549 ; string identifying the compiler.
1551 Common Report Var(flag_no_ident,0)
1552 Process #ident directives.
1555 Common Report Var(flag_if_conversion) Optimization
1556 Perform conversion of conditional jumps to branchless equivalents.
1559 Common Report Var(flag_if_conversion2) Optimization
1560 Perform conversion of conditional jumps to conditional execution.
1563 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1564 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1567 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1570 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1573 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1576 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1578 ftree-loop-if-convert
1579 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1580 Convert conditional jumps in innermost loops to branchless equivalents.
1582 ftree-loop-if-convert-stores
1584 Does nothing. Preserved for backward compatibility.
1586 ; -finhibit-size-directive inhibits output of .size for ELF.
1587 ; This is used only for compiling crtstuff.c,
1588 ; and it may be extended to other effects
1589 ; needed for crtstuff.c on other systems.
1590 finhibit-size-directive
1591 Common Report Var(flag_inhibit_size_directive)
1592 Do not generate .size directives.
1595 Common Report Var(flag_indirect_inlining) Optimization
1596 Perform indirect inlining.
1598 ; General flag to enable inlining. Specifying -fno-inline will disable
1599 ; all inlining apart from always-inline functions.
1601 Common Report Var(flag_no_inline,0) Init(0) Optimization
1602 Enable inlining of function declared \"inline\", disabling disables all inlining.
1604 finline-small-functions
1605 Common Report Var(flag_inline_small_functions) Optimization
1606 Integrate functions into their callers when code size is known not to grow.
1609 Common Report Var(flag_inline_functions) Optimization
1610 Integrate functions not declared \"inline\" into their callers when profitable.
1612 finline-functions-called-once
1613 Common Report Var(flag_inline_functions_called_once) Optimization
1614 Integrate functions only required by their single caller.
1617 Common RejectNegative Joined Alias(finline-limit=)
1620 Common RejectNegative Joined UInteger
1621 -finline-limit=<number> Limit the size of inlined functions to <number>.
1624 Common Report Var(flag_inline_atomics) Init(1) Optimization
1625 Inline __atomic operations when a lock free instruction sequence is available.
1628 Common RejectNegative Alias(fcf-protection=,full)
1631 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1632 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1633 instructions have valid targets.
1636 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Cotrol-Flow Protection Level %qs)
1639 Enum(cf_protection_level) String(full) Value(CF_FULL)
1642 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1645 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1648 Enum(cf_protection_level) String(none) Value(CF_NONE)
1650 finstrument-functions
1651 Common Report Var(flag_instrument_function_entry_exit)
1652 Instrument function entry and exit with profiling calls.
1654 finstrument-functions-exclude-function-list=
1655 Common RejectNegative Joined
1656 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1658 finstrument-functions-exclude-file-list=
1659 Common RejectNegative Joined
1660 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1663 Common Report Var(flag_ipa_cp) Optimization
1664 Perform interprocedural constant propagation.
1667 Common Report Var(flag_ipa_cp_clone) Optimization
1668 Perform cloning to make Interprocedural constant propagation stronger.
1672 Does nothing. Preserved for backward compatibility.
1675 Common Report Var(flag_ipa_bit_cp) Optimization
1676 Perform interprocedural bitwise constant propagation.
1679 Common Report Var(flag_ipa_profile) Init(0) Optimization
1680 Perform interprocedural profile propagation.
1683 Common Report Var(flag_ipa_pta) Init(0) Optimization
1684 Perform interprocedural points-to analysis.
1687 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1688 Discover pure and const functions.
1691 Common Report Var(flag_ipa_icf) Optimization
1692 Perform Identical Code Folding for functions and read-only variables.
1695 Common Report Var(flag_ipa_icf_functions) Optimization
1696 Perform Identical Code Folding for functions.
1699 Common Report Var(flag_ipa_icf_variables) Optimization
1700 Perform Identical Code Folding for variables.
1703 Common Report Var(flag_ipa_reference) Init(0) Optimization
1704 Discover readonly and non addressable static variables.
1708 Does nothing. Preserved for backward compatibility.
1712 Does nothing. Preserved for backward compatibility.
1715 Common Report Var(flag_ipa_vrp) Optimization
1716 Perform IPA Value Range Propagation.
1719 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1720 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1723 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1726 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1729 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1732 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1733 -fira-region=[one|all|mixed] Set regions for IRA.
1736 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1739 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1742 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1745 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1748 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1749 Use IRA based register pressure calculation
1750 in RTL hoist optimizations.
1753 Common Report Var(flag_ira_loop_pressure) Optimization
1754 Use IRA based register pressure calculation
1755 in RTL loop optimizations.
1757 fira-share-save-slots
1758 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1759 Share slots for saving different hard registers.
1761 fira-share-spill-slots
1762 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1763 Share stack slots for spilled pseudo-registers.
1766 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1767 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1770 Common Report Var(flag_ivopts) Init(1) Optimization
1771 Optimize induction variables on trees.
1774 Common Var(flag_jump_tables) Init(1) Optimization
1775 Use jump tables for sufficiently large switch statements.
1777 fkeep-inline-functions
1778 Common Report Var(flag_keep_inline_functions)
1779 Generate code for functions even if they are fully inlined.
1781 fkeep-static-functions
1782 Common Report Var(flag_keep_static_functions)
1783 Generate code for static functions even if they are never called.
1786 Common Report Var(flag_keep_static_consts) Init(1)
1787 Emit static const variables even if they are not used.
1790 Common Report Var(flag_leading_underscore) Init(-1)
1791 Give external symbols a leading underscore.
1795 Does nothing. Preserved for backward compatibility.
1798 Common Report Var(flag_lra_remat) Optimization
1799 Do CFG-sensitive rematerialization in LRA.
1803 Enable link-time optimization.
1806 Common RejectNegative Joined Var(flag_lto)
1807 Link-time optimization with number of parallel jobs or jobserver.
1810 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1813 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1816 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1819 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1822 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1825 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1828 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1829 Specify the algorithm to partition symbols and vars at linktime.
1831 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1832 flto-compression-level=
1833 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1834 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1836 flto-odr-type-merging
1837 Common Report Var(flag_lto_odr_type_mering) Init(1)
1838 Merge C++ types using One Definition Rule.
1841 Common Report Var(flag_lto_report) Init(0)
1842 Report various link-time optimization statistics.
1845 Common Report Var(flag_lto_report_wpa) Init(0)
1846 Report various link-time optimization statistics for WPA only.
1849 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1850 Set errno after built-in math functions.
1853 Common Joined RejectNegative UInteger Var(flag_max_errors)
1854 -fmax-errors=<number> Maximum number of errors to report.
1857 Common Report Var(mem_report)
1858 Report on permanent memory allocation.
1861 Common Report Var(mem_report_wpa)
1862 Report on permanent memory allocation in WPA only.
1864 ; This will attempt to merge constant section constants, if 1 only
1865 ; string constants and constants from constant pool, if 2 also constant
1867 fmerge-all-constants
1868 Common Report Var(flag_merge_constants,2) Init(1)
1869 Attempt to merge identical constants and constant variables.
1872 Common Report Var(flag_merge_constants,1)
1873 Attempt to merge identical constants across compilation units.
1875 fmerge-debug-strings
1876 Common Report Var(flag_merge_debug_strings) Init(1)
1877 Attempt to merge identical debug strings across compilation units.
1880 Common RejectNegative Joined UInteger
1881 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1884 Common Report Var(flag_modulo_sched) Optimization
1885 Perform SMS based modulo scheduling before the first scheduling pass.
1887 fmodulo-sched-allow-regmoves
1888 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1889 Perform SMS based modulo scheduling with register moves allowed.
1891 fmove-loop-invariants
1892 Common Report Var(flag_move_loop_invariants) Optimization
1893 Move loop invariant computations out of loops.
1896 Common Var(flag_dce) Init(1) Optimization
1897 Use the RTL dead code elimination pass.
1900 Common Var(flag_dse) Init(1) Optimization
1901 Use the RTL dead store elimination pass.
1903 freschedule-modulo-scheduled-loops
1904 Common Report Var(flag_resched_modulo_sched) Optimization
1905 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1907 fnon-call-exceptions
1908 Common Report Var(flag_non_call_exceptions) Optimization
1909 Support synchronous non-call exceptions.
1912 Common Driver Joined MissingArgError(options or targets missing after %qs)
1913 -foffload=<targets>=<options> Specify offloading targets and options for them.
1916 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1917 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1920 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1923 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1926 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1929 Common Report Var(flag_omit_frame_pointer) Optimization
1930 When possible do not generate stack frames.
1933 Common Report Var(flag_opt_info) Optimization
1934 Enable all optimization info dumps on stderr.
1937 Common Joined RejectNegative Var(common_deferred_options) Defer
1938 -fopt-info[-<type>=filename] Dump compiler optimization details.
1940 foptimize-register-move
1942 Does nothing. Preserved for backward compatibility.
1944 foptimize-sibling-calls
1945 Common Report Var(flag_optimize_sibling_calls) Optimization
1946 Optimize sibling and tail recursive calls.
1949 Common Report Var(flag_partial_inlining) Optimization
1950 Perform partial inlining.
1953 Common Report Var(pre_ipa_mem_report)
1954 Report on memory allocation before interprocedural optimization.
1956 fpost-ipa-mem-report
1957 Common Report Var(post_ipa_mem_report)
1958 Report on memory allocation before interprocedural optimization.
1961 Common Report Var(flag_pack_struct) Optimization
1962 Pack structure members together without holes.
1965 Common RejectNegative Joined UInteger Optimization
1966 -fpack-struct=<number> Set initial maximum structure member alignment.
1969 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1970 Return small aggregates in memory, not registers.
1973 Common Report Var(flag_peel_loops) Optimization
1974 Perform loop peeling.
1977 Common Report Var(flag_no_peephole,0) Optimization
1978 Enable machine specific peephole optimizations.
1981 Common Report Var(flag_peephole2) Optimization
1982 Enable an RTL peephole pass before sched2.
1985 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1986 Generate position-independent code if possible (large mode).
1989 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1990 Generate position-independent code for executables if possible (large mode).
1993 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1994 Generate position-independent code if possible (small mode).
1997 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1998 Generate position-independent code for executables if possible (small mode).
2001 Common Report Var(flag_plt) Init(1) Optimization
2002 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2005 Common Joined RejectNegative Var(common_deferred_options) Defer
2006 Specify a plugin to load.
2009 Common Joined RejectNegative Var(common_deferred_options) Defer
2010 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2012 fpredictive-commoning
2013 Common Report Var(flag_predictive_commoning) Optimization
2014 Run predictive commoning optimization.
2016 fprefetch-loop-arrays
2017 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2018 Generate prefetch instructions, if available, for arrays in loops.
2021 Common Report Var(profile_flag)
2022 Enable basic program profiling code.
2025 Common Report Var(profile_abs_path_flag)
2026 Generate absolute source path names for gcov.
2029 Common Report Var(profile_arc_flag)
2030 Insert arc-based program profiling code.
2033 Common Joined RejectNegative Var(profile_data_prefix)
2034 Set the top-level directory for storing the profile data.
2035 The default is 'pwd'.
2038 Common Report Var(flag_profile_correction)
2039 Enable correction of flow inconsistent profile data input.
2042 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2043 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2046 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2049 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2052 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2055 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2059 Enable common options for generating profile info for profile feedback directed optimizations.
2062 Common Joined RejectNegative
2063 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2066 Common Var(flag_profile_use)
2067 Enable common options for performing profile feedback directed optimizations.
2070 Common Joined RejectNegative
2071 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2074 Common Report Var(flag_profile_values)
2075 Insert code to profile values of expressions.
2078 Common Report Var(profile_report)
2079 Report on consistency of profile.
2081 fprofile-reorder-functions
2082 Common Report Var(flag_profile_reorder_functions)
2083 Enable function reordering that improves code placement.
2085 fpatchable-function-entry=
2086 Common Joined Optimization
2087 Insert NOP instructions at each function entry.
2090 Common Var(common_deferred_options) Defer
2093 Common Joined RejectNegative Var(common_deferred_options) Defer
2094 -frandom-seed=<string> Make compile reproducible using <string>.
2096 ; This switch causes the command line that was used to create an
2097 ; object file to be recorded into the object file. The exact format
2098 ; of this recording is target and binary file format dependent.
2099 ; It is related to the -fverbose-asm switch, but that switch only
2100 ; records information in the assembler output file as comments, so
2101 ; they never reach the object file.
2102 frecord-gcc-switches
2103 Common Report Var(flag_record_gcc_switches)
2104 Record gcc command line switches in the object file.
2107 Common Report Var(flag_pcc_struct_return,0) Optimization
2108 Return small aggregates in registers.
2112 Does nothing. Preserved for backward compatibility.
2115 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2116 Tell DSE that the storage for a C++ object is dead when the constructor
2117 starts and when the destructor finishes.
2120 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2122 flive-range-shrinkage
2123 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2124 Relief of register pressure through live range shrinkage.
2127 Common Report Var(flag_rename_registers) Init(2) Optimization
2128 Perform a register renaming optimization pass.
2131 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2132 Perform a target dependent instruction fusion optimization pass.
2135 Common Report Var(flag_reorder_blocks) Optimization
2136 Reorder basic blocks to improve code placement.
2138 freorder-blocks-algorithm=
2139 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2140 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2143 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2146 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2149 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2151 freorder-blocks-and-partition
2152 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2153 Reorder basic blocks and partition into hot and cold sections.
2156 Common Report Var(flag_reorder_functions) Optimization
2157 Reorder functions to improve code placement.
2159 frerun-cse-after-loop
2160 Common Report Var(flag_rerun_cse_after_loop) Optimization
2161 Add a common subexpression elimination pass after loop optimizations.
2165 Does nothing. Preserved for backward compatibility.
2168 Common Report Var(flag_rounding_math) Optimization SetByCombined
2169 Disable optimizations that assume default FP rounding behavior.
2172 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2173 Enable scheduling across basic blocks.
2176 Common Report Var(flag_sched_pressure) Init(0) Optimization
2177 Enable register pressure sensitive insn scheduling.
2180 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2181 Allow speculative motion of non-loads.
2184 Common Report Var(flag_schedule_speculative_load) Optimization
2185 Allow speculative motion of some loads.
2187 fsched-spec-load-dangerous
2188 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2189 Allow speculative motion of more loads.
2192 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2193 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2195 fsched2-use-superblocks
2196 Common Report Var(flag_sched2_use_superblocks) Optimization
2197 If scheduling post reload, do superblock scheduling.
2201 Does nothing. Preserved for backward compatibility.
2204 Common Report Var(flag_schedule_insns) Optimization
2205 Reschedule instructions before register allocation.
2208 Common Report Var(flag_schedule_insns_after_reload) Optimization
2209 Reschedule instructions after register allocation.
2211 ; This flag should be on when a target implements non-trivial
2212 ; scheduling hooks, maybe saving some information for its own sake.
2213 ; On IA64, for example, this is used for correct bundling.
2214 fselective-scheduling
2215 Common Report Var(flag_selective_scheduling) Optimization
2216 Schedule instructions using selective scheduling algorithm.
2218 fselective-scheduling2
2219 Common Report Var(flag_selective_scheduling2) Optimization
2220 Run selective scheduling after reload.
2223 Common Undocumented Joined Var(flag_self_test)
2224 Run self-tests, using the given path to locate test files.
2226 fsel-sched-pipelining
2227 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2228 Perform software pipelining of inner loops during selective scheduling.
2230 fsel-sched-pipelining-outer-loops
2231 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2232 Perform software pipelining of outer loops during selective scheduling.
2234 fsel-sched-reschedule-pipelined
2235 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2236 Reschedule pipelined regions without pipelining.
2238 fsemantic-interposition
2239 Common Report Var(flag_semantic_interposition) Init(1)
2240 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2242 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2243 ; of stalled insns into the ready list.
2244 fsched-stalled-insns
2245 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2246 Allow premature scheduling of queued insns.
2248 fsched-stalled-insns=
2249 Common RejectNegative Joined UInteger Optimization
2250 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2252 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2253 ; be examined for a dependency on a stalled insn that is candidate for
2254 ; premature removal from the queue of stalled insns into the ready list (has
2255 ; an effect only if the flag 'sched_stalled_insns' is set).
2256 fsched-stalled-insns-dep
2257 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2258 Set dependence distance checking in premature scheduling of queued insns.
2260 fsched-stalled-insns-dep=
2261 Common RejectNegative Joined UInteger Optimization
2262 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2264 fsched-group-heuristic
2265 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2266 Enable the group heuristic in the scheduler.
2268 fsched-critical-path-heuristic
2269 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2270 Enable the critical path heuristic in the scheduler.
2272 fsched-spec-insn-heuristic
2273 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2274 Enable the speculative instruction heuristic in the scheduler.
2276 fsched-rank-heuristic
2277 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2278 Enable the rank heuristic in the scheduler.
2280 fsched-last-insn-heuristic
2281 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2282 Enable the last instruction heuristic in the scheduler.
2284 fsched-dep-count-heuristic
2285 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2286 Enable the dependent count heuristic in the scheduler.
2289 Common Report Var(flag_section_anchors) Optimization
2290 Access data in the same section from shared anchor points.
2294 Does nothing. Preserved for backward compatibility.
2298 Does nothing. Preserved for backward compatibility.
2301 Common Report Var(flag_ree) Init(0)
2302 Turn on Redundant Extensions Elimination pass.
2305 Common Report Var(flag_show_column) Init(1)
2306 Show column numbers in diagnostics, when available. Default on.
2309 Common Report Var(flag_shrink_wrap) Optimization
2310 Emit function prologues only before parts of the function that need it,
2311 rather than at the top of the function.
2313 fshrink-wrap-separate
2314 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2315 Shrink-wrap parts of the prologue and epilogue separately.
2318 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2319 Disable optimizations observable by IEEE signaling NaNs.
2322 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2323 Disable floating point optimizations that ignore the IEEE signedness of zero.
2325 fsingle-precision-constant
2326 Common Report Var(flag_single_precision_constant) Optimization
2327 Convert floating point constants to single precision constants.
2329 fsplit-ivs-in-unroller
2330 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2331 Split lifetimes of induction variables when loops are unrolled.
2334 Common Report Var(flag_split_stack) Init(-1)
2335 Generate discontiguous stack frames.
2338 Common Report Var(flag_split_wide_types) Optimization
2339 Split wide types into independent registers.
2342 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2343 Enable backward propagation of use properties at the SSA level.
2346 Common Report Var(flag_ssa_phiopt) Optimization
2347 Optimize conditional patterns using SSA PHI nodes.
2350 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2351 Optimize amount of stdarg registers saved to stack at start of function.
2353 fvariable-expansion-in-unroller
2354 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2355 Apply variable expansion when loops are unrolled.
2358 Common Report RejectNegative Joined Optimization
2359 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2362 Common Alias(fstack-check=, specific, no)
2363 Insert stack checking code into the program. Same as -fstack-check=specific.
2365 fstack-clash-protection
2366 Common Report Var(flag_stack_clash_protection) Optimization
2367 Insert code to probe each page of stack space as it is allocated to protect
2368 from stack-clash style attacks.
2371 Common Var(common_deferred_options) Defer
2373 fstack-limit-register=
2374 Common RejectNegative Joined Var(common_deferred_options) Defer
2375 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2377 fstack-limit-symbol=
2378 Common RejectNegative Joined Var(common_deferred_options) Defer
2379 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2382 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2383 Use propolice as a stack protection method.
2385 fstack-protector-all
2386 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2387 Use a stack protection method for every function.
2389 fstack-protector-strong
2390 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2391 Use a smart stack protection method for certain functions.
2393 fstack-protector-explicit
2394 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2395 Use stack protection method only for functions with the stack_protect attribute.
2398 Common RejectNegative Var(flag_stack_usage)
2399 Output stack usage information on a per-function basis.
2403 Does nothing. Preserved for backward compatibility.
2405 ; Nonzero if we should do (language-dependent) alias analysis.
2406 ; Typically, this analysis will assume that expressions of certain
2407 ; types do not alias expressions of certain other types. Only used
2408 ; if alias analysis (in general) is enabled.
2410 Common Report Var(flag_strict_aliasing) Optimization
2411 Assume strict aliasing rules apply.
2414 Common NegativeAlias Alias(fwrapv)
2415 Treat signed overflow as undefined. Negated as -fwrapv.
2418 Common Report Var(flag_sync_libcalls) Init(1)
2419 Implement __atomic operations via libcalls to legacy __sync functions.
2422 Common Report Var(flag_syntax_only)
2423 Check for syntax errors, then stop.
2426 Common Report Var(flag_test_coverage)
2427 Create data files needed by \"gcov\".
2430 Common Report Var(flag_thread_jumps) Optimization
2431 Perform jump threading optimizations.
2434 Common Report Var(time_report)
2435 Report the time taken by each compiler pass.
2437 ftime-report-details
2438 Common Report Var(time_report_details)
2439 Record times taken by sub-phases separately.
2442 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2443 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2446 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2449 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2452 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2455 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2458 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2461 Common Report Var(flag_toplevel_reorder) Init(2)
2462 Reorder top level functions, variables, and asms.
2465 Common Report Var(flag_tracer) Optimization
2466 Perform superblock formation via tail duplication.
2469 Common Report Var(flag_trampolines) Init(0)
2470 For targets that normally need trampolines for nested functions, always
2471 generate them instead of using descriptors.
2473 ; Zero means that floating-point math operations cannot generate a
2474 ; (user-visible) trap. This is the case, for example, in nonstop
2475 ; IEEE 754 arithmetic.
2477 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2478 Assume floating-point operations can trap.
2481 Common Report Var(flag_trapv) Optimization
2482 Trap for signed overflow in addition, subtraction and multiplication.
2485 Common Report Var(flag_tree_ccp) Optimization
2486 Enable SSA-CCP optimization on trees.
2489 Common Report Var(flag_tree_bit_ccp) Optimization
2490 Enable SSA-BIT-CCP optimization on trees.
2494 Does nothing. Preserved for backward compatibility.
2497 Common Report Var(flag_tree_ch) Optimization
2498 Enable loop header copying on trees.
2500 ftree-coalesce-inlined-vars
2501 Common Ignore RejectNegative
2502 Does nothing. Preserved for backward compatibility.
2505 Common Report Var(flag_tree_coalesce_vars) Optimization
2506 Enable SSA coalescing of user variables.
2510 Does nothing. Preserved for backward compatibility.
2513 Common Report Var(flag_tree_copy_prop) Optimization
2514 Enable copy propagation on trees.
2516 ftree-store-copy-prop
2518 Does nothing. Preserved for backward compatibility.
2521 Common Report Var(flag_tree_cselim) Init(2) Optimization
2522 Transform condition stores into unconditional ones.
2524 ftree-switch-conversion
2525 Common Report Var(flag_tree_switch_conversion) Optimization
2526 Perform conversions of switch initializations.
2529 Common Report Var(flag_tree_dce) Optimization
2530 Enable SSA dead code elimination optimization on trees.
2532 ftree-dominator-opts
2533 Common Report Var(flag_tree_dom) Optimization
2534 Enable dominator optimizations.
2537 Common Report Var(flag_tree_tail_merge) Optimization
2538 Enable tail merging on trees.
2541 Common Report Var(flag_tree_dse) Optimization
2542 Enable dead store elimination.
2545 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2546 Enable forward propagation on trees.
2549 Common Report Var(flag_tree_fre) Optimization
2550 Enable Full Redundancy Elimination (FRE) on trees.
2553 Common Report Var(flag_optimize_strlen) Optimization
2554 Enable string length optimizations on trees.
2556 fisolate-erroneous-paths-dereference
2557 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2558 Detect paths that trigger erroneous or undefined behavior due to
2559 dereferencing a null pointer. Isolate those paths from the main control
2560 flow and turn the statement with erroneous or undefined behavior into a trap.
2562 fisolate-erroneous-paths-attribute
2563 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2564 Detect paths that trigger erroneous or undefined behavior due to a null value
2565 being used in a way forbidden by a returns_nonnull or nonnull
2566 attribute. Isolate those paths from the main control flow and turn the
2567 statement with erroneous or undefined behavior into a trap.
2569 ftree-loop-distribution
2570 Common Report Var(flag_tree_loop_distribution) Optimization
2571 Enable loop distribution on trees.
2573 ftree-loop-distribute-patterns
2574 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2575 Enable loop distribution for patterns transformed into a library call.
2578 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2579 Enable loop invariant motion on trees.
2582 Common Alias(floop-nest-optimize)
2583 Enable loop nest transforms. Same as -floop-nest-optimize.
2586 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2587 Create canonical induction variables in loops.
2590 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2591 Enable loop optimizations on tree level.
2593 ftree-parallelize-loops=
2594 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2595 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2598 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2599 Enable hoisting loads from conditional pointers.
2602 Common Report Var(flag_tree_pre) Optimization
2603 Enable SSA-PRE optimization on trees.
2606 Common Report Var(flag_tree_partial_pre) Optimization
2607 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2610 Common Report Var(flag_tree_pta) Optimization
2611 Perform function-local points-to analysis on trees.
2614 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2615 Enable reassociation on tree level.
2619 Does nothing. Preserved for backward compatibility.
2622 Common Report Var(flag_tree_sink) Optimization
2623 Enable SSA code sinking on trees.
2626 Common Report Var(flag_tree_slsr) Optimization
2627 Perform straight-line strength reduction.
2630 Common Report Var(flag_tree_sra) Optimization
2631 Perform scalar replacement of aggregates.
2634 Common Report Var(flag_tree_ter) Optimization
2635 Replace temporary expressions in the SSA->normal pass.
2638 Common Report Var(flag_tree_live_range_split) Optimization
2639 Perform live range splitting during the SSA->normal pass.
2642 Common Report Var(flag_tree_vrp) Init(0) Optimization
2643 Perform Value Range Propagation on trees.
2646 Common Report Var(flag_split_paths) Init(0) Optimization
2647 Split paths leading to loop backedges.
2649 funconstrained-commons
2650 Common Var(flag_unconstrained_commons) Optimization
2651 Assume common declarations may be overridden with ones with a larger
2655 Common Report Var(flag_unit_at_a_time) Init(1)
2656 Compile whole compilation unit at a time.
2659 Common Report Var(flag_unroll_loops) Optimization
2660 Perform loop unrolling when iteration count is known.
2663 Common Report Var(flag_unroll_all_loops) Optimization
2664 Perform loop unrolling for all loops.
2666 ; Nonzero means that loop optimizer may assume that the induction variables
2667 ; that control loops do not overflow and that the loops with nontrivial
2668 ; exit condition are not infinite
2669 funsafe-loop-optimizations
2671 Does nothing. Preserved for backward compatibility.
2674 Common Report Var(flag_associative_math) SetByCombined Optimization
2675 Allow optimization for floating-point arithmetic which may change the
2676 result of the operation due to rounding.
2679 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2680 Same as -fassociative-math for expressions which include division.
2682 ; Nonzero means that unsafe floating-point math optimizations are allowed
2683 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2684 ; are allowed to assume that their arguments and results are "normal"
2685 ; (e.g., nonnegative for SQRT).
2686 funsafe-math-optimizations
2687 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2688 Allow math optimizations that may violate IEEE or ISO standards.
2691 Common Report Var(flag_unswitch_loops) Optimization
2692 Perform loop unswitching.
2695 Common Report Var(flag_split_loops) Optimization
2696 Perform loop splitting.
2699 Common Report Var(flag_unwind_tables) Optimization
2700 Just generate unwind tables for exception handling.
2703 Common Driver Negative(fuse-ld=gold)
2704 Use the bfd linker instead of the default linker.
2707 Common Driver Negative(fuse-ld=bfd)
2708 Use the gold linker instead of the default linker.
2711 Common Undocumented Var(flag_use_linker_plugin)
2713 ; Positive if we should track variables, negative if we should run
2714 ; the var-tracking pass only to discard debug annotations, zero if
2715 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2716 ; will be set according to optimize, debug_info_level and debug_hooks
2717 ; in process_options ().
2719 Common Report Var(flag_var_tracking) Init(2) PerFunction
2720 Perform variable tracking.
2722 ; Positive if we should track variables at assignments, negative if
2723 ; we should run the var-tracking pass only to discard debug
2724 ; annotations. When flag_var_tracking_assignments ==
2725 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2726 fvar-tracking-assignments
2727 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2728 Perform variable tracking by annotating assignments.
2730 ; Nonzero if we should toggle flag_var_tracking_assignments after
2731 ; processing options and computing its default. */
2732 fvar-tracking-assignments-toggle
2733 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2734 Toggle -fvar-tracking-assignments.
2736 ; Positive if we should track uninitialized variables, negative if
2737 ; we should run the var-tracking pass only to discard debug
2738 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2739 ; will be set according to flag_var_tracking.
2740 fvar-tracking-uninit
2741 Common Report Var(flag_var_tracking_uninit) PerFunction
2742 Perform variable tracking and also tag variables that are uninitialized.
2744 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2746 Common Report Optimization
2747 Enable vectorization on trees.
2749 ftree-vectorizer-verbose=
2750 Common Joined RejectNegative Ignore
2751 Does nothing. Preserved for backward compatibility.
2753 ftree-loop-vectorize
2754 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2755 Enable loop vectorization on trees.
2758 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2759 Enable basic block vectorization (SLP) on trees.
2762 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2763 Specifies the cost model for vectorization.
2764 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2767 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2768 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2771 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2774 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2777 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2780 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2783 Common Alias(fvect-cost-model=,dynamic,unlimited)
2784 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2786 ftree-vect-loop-version
2788 Does nothing. Preserved for backward compatibility.
2791 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2792 Enable copy propagation of scalar-evolution information.
2794 ; -fverbose-asm causes extra commentary information to be produced in
2795 ; the generated assembly code (to make it more readable). This option
2796 ; is generally only of use to those who actually need to read the
2797 ; generated assembly code (perhaps while debugging the compiler itself).
2798 ; -fno-verbose-asm, the default, causes the extra information
2799 ; to not be added and is useful when comparing two assembler files.
2801 Common Report Var(flag_verbose_asm)
2802 Add extra commentary to assembler output.
2805 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2806 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2809 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2812 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2815 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2818 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2821 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2824 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2825 Validate vtable pointers before using them.
2828 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2831 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2834 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2837 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2840 Common Var(flag_vtv_counts)
2841 Output vtable verification counters.
2844 Common Var(flag_vtv_debug)
2845 Output vtable verification pointer sets information.
2848 Common Report Var(flag_value_profile_transformations) Optimization
2849 Use expression value profiles in optimizations.
2852 Common Report Var(flag_web) Init(2) Optimization
2853 Construct webs and split unrelated uses of single variable.
2855 ftree-builtin-call-dce
2856 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2857 Enable conditional dead code elimination for builtin calls.
2860 Common Report Var(flag_whole_program) Init(0)
2861 Perform whole program optimizations.
2864 Common Report Var(flag_wrapv) Optimization
2865 Assume signed arithmetic overflow wraps around.
2867 fzero-initialized-in-bss
2868 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2869 Put zero initialized data in the bss section.
2872 Common Driver RejectNegative JoinedOrMissing
2873 Generate debug information in default format.
2876 Common Driver Ignore Warn(switch %qs no longer supported)
2877 Does nothing. Preserved for backward compatibility.
2880 Common Driver Ignore Warn(switch %qs no longer supported)
2881 Does nothing. Preserved for backward compatibility.
2884 Common Driver Ignore Warn(switch %qs no longer supported)
2885 Does nothing. Preserved for backward compatibility.
2888 Common Driver Ignore Warn(switch %qs no longer supported)
2889 Does nothing. Preserved for backward compatibility.
2892 Common Driver Var(debug_column_info,1) Init(1)
2893 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2896 Common Driver JoinedOrMissing Negative(gdwarf-)
2897 Generate debug information in default version of DWARF format.
2900 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2901 Generate debug information in DWARF v2 (or later) format.
2904 Common Driver JoinedOrMissing
2905 Generate debug information in default extended format.
2908 RejectNegative Joined Undocumented
2909 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
2912 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2913 Don't generate DWARF pubnames and pubtypes sections.
2916 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2917 Generate DWARF pubnames and pubtypes sections.
2920 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2921 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2923 grecord-gcc-switches
2924 Common Driver Var(dwarf_record_gcc_switches) Init(1)
2925 Record gcc command line switches in DWARF DW_AT_producer.
2928 Common Driver Var(dwarf_split_debug_info) Init(0)
2929 Generate debug information in separate .dwo files.
2932 Common Driver JoinedOrMissing Negative(gstabs+)
2933 Generate debug information in STABS format.
2936 Common Driver JoinedOrMissing Negative(gvms)
2937 Generate debug information in extended STABS format.
2940 Common Driver Report Var(dwarf_strict) Init(0)
2941 Don't emit DWARF additions beyond selected version.
2944 Common Driver Report Var(flag_gtoggle)
2945 Toggle debug information generation.
2948 Common Driver JoinedOrMissing Negative(gxcoff)
2949 Generate debug information in VMS format.
2952 Common Driver JoinedOrMissing Negative(gxcoff+)
2953 Generate debug information in XCOFF format.
2956 Common Driver JoinedOrMissing Negative(gdwarf)
2957 Generate debug information in extended XCOFF format.
2960 Name(compressed_debug_sections) Type(int)
2962 ; Since -gz= is completely handled in specs, the values aren't used and we
2963 ; assign arbitrary constants.
2965 Enum(compressed_debug_sections) String(none) Value(0)
2968 Enum(compressed_debug_sections) String(zlib) Value(1)
2971 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2975 Generate compressed debug sections.
2978 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
2979 -gz=<format> Generate compressed debug sections in format <format>.
2982 Driver Joined Separate
2985 Common Joined Var(plugindir_string) Init(0)
2986 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2989 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2990 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2993 Driver Joined Separate
2998 no-canonical-prefixes
3011 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3012 -o <file> Place output into <file>.
3015 Common Var(profile_flag)
3016 Enable function profiling.
3019 Driver Var(pass_exit_codes)
3022 Common Alias(Wpedantic)
3025 Common Var(flag_pedantic_errors)
3026 Like -pedantic but issue them as errors.
3032 Driver Var(use_pipes)
3035 Driver JoinedOrMissing Var(print_file_name)
3037 print-libgcc-file-name
3040 print-multi-directory
3041 Driver Var(print_multi_directory)
3044 Driver Var(print_multi_lib)
3046 print-multi-os-directory
3047 Driver Var(print_multi_os_directory)
3050 Driver Var(print_multiarch)
3053 Driver JoinedOrMissing Var(print_prog_name)
3056 Driver Var(print_search_dirs)
3059 Driver Var(print_sysroot)
3061 print-sysroot-headers-suffix
3062 Driver Var(print_sysroot_headers_suffix)
3065 Common Var(quiet_flag) RejectDriver
3066 Do not display functions compiled or elapsed time.
3084 Driver Var(report_times)
3087 Driver JoinedOrMissing
3090 Driver Joined Separate
3094 ; C option, but driver must not handle as "-u ndef".
3097 Common Driver Var(verbose_flag)
3098 Enable verbose output.
3101 Common Var(version_flag) RejectDriver
3102 Display the compiler's version.
3105 Common Var(inhibit_warnings)
3109 Driver Separate Var(wrapper_string)
3112 Driver Joined Separate
3115 Driver RejectNegative Negative(static-pie)
3116 Create a shared library.
3122 Driver Separate Alias(specs=)
3135 ; Documented for Fortran, but always accepted by driver.
3142 ; Documented for Go, but always accepted by driver.
3160 Driver RejectNegative Negative(shared)
3161 Don't create a dynamically linked position independent executable.
3164 Driver RejectNegative Negative(no-pie)
3165 Create a dynamically linked position independent executable.
3168 Driver RejectNegative Negative(pie)
3169 Create a static position independent executable.
3172 Driver Joined Separate
3175 Common Report Var(flag_ipa_ra) Optimization
3176 Use caller save register across calls if possible.
3178 ; This comment is to ensure we retain the blank line above.