1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2018 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) and 2 indicates that the IL is going to be linked and
52 ; and output to LTO object file.
54 enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE
56 ; 0 means straightforward implementation of complex divide acceptable.
57 ; 1 means wide ranges of inputs must work for complex divide.
58 ; 2 means C99-like requirements for complex multiply and divide.
60 int flag_complex_method = 1
62 ; Language specific warning pass for unused results.
64 bool flag_warn_unused_result = false
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
75 int flag_generate_offload = 0
77 ; True to warn about any objects definitions whose size is larger
78 ; than N bytes. Also want about function definitions whose returned
79 ; values are larger than N bytes, where N is 'larger_than_size'.
84 HOST_WIDE_INT larger_than_size
86 ; True to warn about any function whose frame size is larger
89 bool warn_frame_larger_than
92 HOST_WIDE_INT frame_larger_than_size
94 ; Nonzero means we should be saving declaration info into a .X file.
96 int flag_gen_aux_info = 0
98 ; Nonzero if we are compiling code for a shared library, zero for
103 ; These two are really VEC(char_p,heap) *.
106 void *flag_instrument_functions_exclude_functions
109 void *flag_instrument_functions_exclude_files
111 ; Generic structs (e.g. templates not explicitly specialized)
112 ; may not have a compilation unit associated with them, and so
113 ; may need to be treated differently from ordinary structs.
115 ; Structs only handled by reference (indirectly), will also usually
116 ; not need as much debugging information.
119 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
122 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
124 ; True if we should exit after parsing options.
126 bool exit_after_options
128 ; Type(s) of debugging information we are producing (if any). See
129 ; flag-types.h for the definitions of the different possible types of
130 ; debugging information.
132 enum debug_info_type write_symbols = NO_DEBUG
134 ; Level of debugging information we are producing. See flag-types.h
135 ; for the definitions of the different possible levels.
137 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
139 ; Nonzero means use GNU-only extensions in the generated symbolic
140 ; debugging information. Currently, this only has an effect when
141 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
143 bool use_gnu_debug_info_extensions
145 ; Original value of maximum field alignment in bytes, specified via
146 ; -fpack-struct=<value>.
148 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
150 ; Type of stack check.
152 enum stack_check_type flag_stack_check = NO_STACK_CHECK
154 ; True if stack usage information needs to be computed.
156 bool flag_stack_usage_info = false
158 ; -dA causes debug commentary information to be produced in
159 ; the generated assembly code (to make it more readable). This option
160 ; is generally only of use to those who actually need to read the
161 ; generated assembly code (perhaps while debugging the compiler itself).
162 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
163 ; to be a catchall for printing debug information in the assembler file.
167 ; How many NOP insns to place at each function entry by default
169 HOST_WIDE_INT function_entry_patch_area_size
171 ; And how far the real asm entry point is into this area
173 HOST_WIDE_INT function_entry_patch_area_start
175 ; Balance between GNAT encodings and standard DWARF to emit.
177 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
179 ; -dP causes the rtl to be emitted as a comment in assembly.
181 int flag_dump_rtl_in_asm
183 ; Whether -da was passed (used only in handle_common_deferred_options).
185 bool flag_dump_all_passed
187 ; Other flags saying which kinds of debugging dump have been requested.
190 int rtl_dump_and_exit
193 int flag_print_asm_name
195 ; Name of top-level original source file (what was input to cpp).
196 ; This comes from the #-command at the beginning of the actual input.
197 ; If there isn't any there, then this is the cc1 input file name.
199 const char *main_input_filename
201 ; Pointer to base name in main_input_filename, with directories and a
202 ; single final extension removed, and the length of this base
206 const char *main_input_basename
209 int main_input_baselength
211 ; Which options have been printed by --help.
215 ; Which enums have been printed by --help. 0 = not printed, no
216 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
219 char *help_enum_printed
221 ; The number of columns for --help output.
223 unsigned int help_columns
225 ; Whether this options structure has been through finish_options
227 bool flag_opts_finished
229 ; What the sanitizer should instrument
231 unsigned int flag_sanitize
233 ; What sanitizers should recover from errors
235 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
237 ; What the coverage sanitizers should instrument
239 unsigned int flag_sanitize_coverage
241 ; Flag whether a prefix has been added to dump_base_name
243 bool dump_base_name_prefixed = false
245 ; Flag whether HSA generation has been explicitely disabled
247 bool flag_disable_hsa = false
259 Common Driver Joined Undocumented
260 Provide bash completion for options starting with provided string.
263 Driver Alias(coverage)
269 Common Separate Alias(d)
272 Common Joined Alias(d)
275 Common Separate Alias(dumpbase)
278 Common Separate Alias(dumpdir)
281 Driver Separate Alias(e)
284 Driver Joined Alias(e)
287 Common Warning Alias(Wextra)
290 Driver Separate Alias(Xassembler)
293 Driver JoinedOrMissing Alias(Xassembler)
296 Driver Separate Alias(Xlinker)
299 Driver JoinedOrMissing Alias(Xlinker)
302 Driver Separate Alias(u)
305 Driver Joined Alias(u)
308 Common Driver Var(help_flag)
309 Display this information.
312 Common Driver Report Joined
313 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
316 Driver Separate Alias(x)
319 Driver Joined Alias(x)
322 Driver Separate Alias(L)
325 Driver Joined Alias(L)
327 -no-canonical-prefixes
328 Driver Alias(no-canonical-prefixes)
330 -no-standard-libraries
331 Driver Alias(nostdlib)
334 Driver Var(no_sysroot_suffix)
343 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
346 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
349 Driver Alias(pass-exit-codes)
352 Common Alias(Wpedantic)
355 Common Alias(pedantic-errors)
361 Driver Alias(static-pie)
367 Driver Separate Alias(B)
370 Driver JoinedOrMissing Alias(B)
376 Driver Separate Alias(print-file-name=)
379 Driver JoinedOrMissing Alias(print-file-name=)
381 -print-libgcc-file-name
382 Driver Alias(print-libgcc-file-name)
384 -print-multi-directory
385 Driver Alias(print-multi-directory)
388 Driver Alias(print-multi-lib)
390 -print-multi-os-directory
391 Driver Alias(print-multi-os-directory)
394 Driver Alias(print-multiarch)
397 Driver Separate Alias(print-prog-name=)
400 Driver JoinedOrMissing Alias(print-prog-name=)
403 Driver Alias(print-search-dirs)
406 Driver Alias(print-sysroot)
408 -print-sysroot-headers-suffix
409 Driver Alias(print-sysroot-headers-suffix)
415 Driver Alias(save-temps)
421 Driver Separate Alias(specs=)
424 Driver Joined Alias(specs=)
430 Driver Alias(symbolic)
434 Alias for --help=target.
442 ;; The driver used to convert options such as --help into forms such
443 ;; as -fhelp; the following four entries are for compatibility with
444 ;; any direct uses of those (undocumented) -f forms
446 Common Driver Alias(-help)
449 Common Driver Joined Alias(-help=)
452 Common Driver Alias(-target-help)
455 Common Driver Alias(-version)
459 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
462 Common Joined Alias(-param)
465 Driver Separate Alias(-sysroot=)
468 Driver JoinedOrMissing
474 Driver Joined Separate
480 Driver Joined Separate
486 Common JoinedOrMissing Optimization
487 -O<number> Set optimization level to <number>.
491 Optimize for space rather than speed.
495 Optimize for speed disregarding exact standards compliance.
499 Optimize for debugging experience rather than speed or size.
511 Driver Joined Separate
517 Driver Joined Separate
538 Common RejectNegative Warning Alias(Wextra)
539 This switch is deprecated; use -Wextra instead.
542 Driver JoinedOrMissing RejectNegative
545 Driver JoinedOrMissing RejectNegative
548 Driver JoinedOrMissing RejectNegative
551 Common Var(warn_aggregate_return) Warning
552 Warn about returning structures, unions or arrays.
554 Waggressive-loop-optimizations
555 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
556 Warn if a loop with constant number of iterations triggers undefined behavior.
559 Common Var(warn_array_bounds) Warning
560 Warn if an array is accessed out of bounds.
563 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
564 Warn if an array is accessed out of bounds.
567 Common Var(warn_attributes) Init(1) Warning
568 Warn about inappropriate attribute usage.
571 Common Var(warn_attributes) Init(1) Warning
572 Warn about type safety and similar errors in attribute alias and related.
575 Common Var(warn_cast_align) Warning
576 Warn about pointer casts which increase alignment.
579 Common Var(warn_cast_align,2) Warning
580 Warn about pointer casts which increase alignment.
583 Common Var(warn_cpp) Init(1) Warning
584 Warn when a #warning directive is encountered.
586 Wdeprecated-declarations
587 Common Var(warn_deprecated_decl) Init(1) Warning
588 Warn about uses of __attribute__((deprecated)) declarations.
590 Wdisabled-optimization
591 Common Var(warn_disabled_optimization) Warning
592 Warn when an optimization pass is disabled.
595 Common Var(warnings_are_errors)
596 Treat all warnings as errors.
600 Treat specified warning as error.
603 Common Var(extra_warnings) Warning
604 Print extra (possibly unwanted) warnings.
607 Common Var(flag_fatal_errors)
608 Exit on the first error occurred.
611 Common RejectNegative Joined UInteger Warning
612 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes.
615 Common Var(warn_free_nonheap_object) Init(1) Warning
616 Warn when attempting to free a non-heap object.
619 Common Var(warn_hsa) Init(1) Warning
620 Warn when a function cannot be expanded to HSAIL.
622 Wimplicit-fallthrough
623 Common Alias(Wimplicit-fallthrough=,3,0) Warning
625 Wimplicit-fallthrough=
626 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
627 Warn when a switch case falls through.
630 Common Var(warn_inline) Warning
631 Warn when an inlined function cannot be inlined.
633 Winvalid-memory-model
634 Common Var(warn_invalid_memory_model) Init(1) Warning
635 Warn when an atomic memory model parameter is known to be outside the valid range.
638 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
641 Common RejectNegative Joined UInteger Warning
642 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
645 Var(warn_nonnull_compare) Warning
646 Warn if comparing pointer parameter with nonnull attribute with NULL.
649 Common Var(warn_null_dereference) Warning
650 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
652 Wunsafe-loop-optimizations
653 Common Ignore Warning
654 Does nothing. Preserved for backward compatibility.
657 Common Warning Alias(Wsuggest-attribute=noreturn)
660 Common Var(warn_odr_violations) Init(1) Warning
661 Warn about some C++ One Definition Rule violations during link time optimization.
664 Common Var(warn_overflow) Init(1) Warning
665 Warn about overflow in arithmetic expressions.
668 Common Var(warn_lto_type_mismatch) Init(1) Warning
669 During link time optimization warn about mismatched types of global declarations.
672 Common Var(warn_packed) Warning
673 Warn when the packed attribute has no effect on struct layout.
676 Common Var(warn_padded) Warning
677 Warn when padding is required to align structure members.
680 Common Var(pedantic) Init(0) Warning
681 Issue warnings needed for strict compliance to the standard.
684 Common Var(warn_return_local_addr) Init(1) Warning
685 Warn about returning a pointer/reference to a local or temporary variable.
688 Common Var(warn_shadow) Warning
689 Warn when one variable shadows another. Same as -Wshadow=global.
692 Common Warning Alias(Wshadow)
693 Warn when one variable shadows another (globally).
696 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
697 Warn when one local variable shadows another local variable or parameter.
700 Common Warning Undocumented Alias(Wshadow=local)
702 Wshadow=compatible-local
703 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
704 Warn when one local variable shadows another local variable or parameter of compatible type.
706 Wshadow-compatible-local
707 Common Warning Undocumented Alias(Wshadow=compatible-local)
710 Common Var(warn_stack_protect) Warning
711 Warn when not issuing stack smashing protection for some reason.
714 Common Joined RejectNegative UInteger Var(warn_stack_usage) Warning
715 -Wstack-usage=<number> Warn if stack usage might be larger than specified amount.
719 Warn about code which might break strict aliasing rules.
722 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
723 Warn about code which might break strict aliasing rules.
727 Warn about optimizations that assume that signed overflow is undefined.
730 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
731 Warn about optimizations that assume that signed overflow is undefined.
733 Wsuggest-attribute=cold
734 Common Var(warn_suggest_attribute_cold) Warning
735 Warn about functions which might be candidates for __attribute__((cold)).
737 Wsuggest-attribute=const
738 Common Var(warn_suggest_attribute_const) Warning
739 Warn about functions which might be candidates for __attribute__((const)).
741 Wsuggest-attribute=pure
742 Common Var(warn_suggest_attribute_pure) Warning
743 Warn about functions which might be candidates for __attribute__((pure)).
745 Wsuggest-attribute=noreturn
746 Common Var(warn_suggest_attribute_noreturn) Warning
747 Warn about functions which might be candidates for __attribute__((noreturn)).
749 Wsuggest-attribute=malloc
750 Common Var(warn_suggest_attribute_malloc) Warning
751 Warn about functions which might be candidates for __attribute__((malloc)).
754 Common Var(warn_suggest_final_types) Warning
755 Warn about C++ polymorphic types where adding final keyword would improve code quality.
757 Wsuggest-final-methods
758 Common Var(warn_suggest_final_methods) Warning
759 Warn about C++ virtual methods where adding final keyword would improve code quality.
762 Common Var(warn_switch_unreachable) Warning Init(1)
763 Warn about statements between switch's controlling expression and the first
767 Common Var(warn_system_headers) Warning
768 Do not suppress warnings from system headers.
771 Common Var(warn_trampolines) Warning
772 Warn whenever a trampoline is generated.
775 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
776 Warn if a comparison is always true or always false due to the limited range of the data type.
779 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
780 Warn about uninitialized automatic variables.
783 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
784 Warn about maybe uninitialized automatic variables.
787 Common Ignore Warning
788 Does nothing. Preserved for backward compatibility.
791 Common Var(warn_unused) Init(0) Warning
792 Enable all -Wunused- warnings.
794 Wunused-but-set-parameter
795 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
796 Warn when a function parameter is only set, otherwise unused.
798 Wunused-but-set-variable
799 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
800 Warn when a variable is only set, otherwise unused.
803 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
804 Warn when a function is unused.
807 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
808 Warn when a label is unused.
811 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
812 Warn when a function parameter is unused.
815 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
816 Warn when an expression value is unused.
819 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
820 Warn when a variable is unused.
823 Common Var(warn_coverage_mismatch) Init(1) Warning
824 Warn in case profiles in -fprofile-use do not match.
826 Wvector-operation-performance
827 Common Var(warn_vector_operation_performance) Warning
828 Warn when a vector operation is compiled outside the SIMD.
843 Common Separate Var(aux_info_file_name)
844 -aux-info <file> Emit declaration information into <file>.
847 Common Joined Alias(aux-info)
850 Common Separate RejectDriver Var(aux_base_name)
853 Common Separate RejectDriver
863 -d<letters> Enable dumps from specific passes of the compiler.
866 Common Separate Var(dump_base_name)
867 -dumpbase <file> Set the file basename to be used for dumps.
870 Common Separate Var(dump_dir_name)
871 -dumpdir <dir> Set the directory name to be used for dumps.
886 Driver Joined Separate
888 ; This option has historically been passed down to the linker by an
889 ; accident of a %{e*} spec, so ensure it continues to be passed down
890 ; as a single option. The supported option for this purpose is
891 ; -rdynamic. See PR 47390.
895 ; The version of the C++ ABI in use. The following values are allowed:
897 ; 0: The version of the ABI believed most conformant with the C++ ABI
898 ; specification. This ABI may change as bugs are discovered and fixed.
899 ; Therefore, 0 will not necessarily indicate the same ABI in different
902 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
904 ; 2: The version of the ABI first used in G++ 3.4, and the default
907 ; 3: The version of the ABI that fixes the missing underscore
908 ; in template non-type arguments of pointer type.
910 ; 4: The version of the ABI that introduces unambiguous mangling of
911 ; vector types. First selectable in G++ 4.5.
913 ; 5: The version of the ABI that ignores attribute const/noreturn
914 ; in function pointer mangling, and corrects mangling of decltype and
915 ; function parameters used in other parameters and the return type.
916 ; First selectable in G++ 4.6.
918 ; 6: The version of the ABI that doesn't promote scoped enums to int and
919 ; changes the mangling of template argument packs, const/static_cast,
920 ; prefix ++ and --, and a class scope function used as a template
922 ; First selectable in G++ 4.7.
924 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
925 ; corrects the mangling of lambdas in default argument scope.
926 ; First selectable in G++ 4.8.
928 ; 8: The version of the ABI that corrects the substitution behavior of
929 ; function types with function-cv-qualifiers.
930 ; First selectable in G++ 4.9 and default in G++ 5.
932 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
933 ; First selectable and default in G++ 5.2.
935 ; 10: The version of the ABI that mangles attributes that affect type
936 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
937 ; Default in G++ 6 (set in c_common_post_options).
939 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
940 ; and introduces new inheriting constructor handling.
943 ; 12: Corrects the calling convention for classes with only deleted copy/move
944 ; constructors and changes passing/returning of empty records.
945 ; Default in G++ 8.1.
947 ; 13: Fixes the accidental change in 12 to the calling convention for classes
948 ; with deleted copy constructor and trivial move constructor.
949 ; Default in G++ 8.2.
951 ; Additional positive integers will be assigned as new versions of
952 ; the ABI become the default version of the ABI.
954 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
955 The version of the C++ ABI in use.
957 faggressive-loop-optimizations
958 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
959 Aggressively optimize loops using language constraints.
962 Common Report Var(flag_align_functions) Optimization
963 Align the start of functions.
966 Common RejectNegative Joined Var(str_align_functions) Optimization
968 flimit-function-alignment
969 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
972 Common Report Var(flag_align_jumps) Optimization
973 Align labels which are only reached by jumping.
976 Common RejectNegative Joined Var(str_align_jumps) Optimization
979 Common Report Var(flag_align_labels) Optimization
983 Common RejectNegative Joined Var(str_align_labels) Optimization
986 Common Report Var(flag_align_loops) Optimization
987 Align the start of loops.
990 Common RejectNegative Joined Var(str_align_loops)
994 Does nothing. Preserved for backward compatibility.
998 Does nothing. Preserved for backward compatibility.
1000 fargument-noalias-global
1002 Does nothing. Preserved for backward compatibility.
1004 fargument-noalias-anything
1006 Does nothing. Preserved for backward compatibility.
1009 Common Driver Report Joined
1010 Select what to sanitize.
1013 Common Report Joined
1014 Select type of coverage sanitization.
1016 fasan-shadow-offset=
1017 Common Joined RejectNegative Var(common_deferred_options) Defer
1018 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1021 Common Joined RejectNegative Var(common_deferred_options) Defer
1022 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1023 in user-defined sections.
1026 Common Report Joined
1027 After diagnosing undefined behavior attempt to continue execution.
1031 This switch is deprecated; use -fsanitize-recover= instead.
1033 fsanitize-address-use-after-scope
1034 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1036 fsanitize-undefined-trap-on-error
1037 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1038 Use trap instead of a library function for undefined behavior sanitization.
1040 fasynchronous-unwind-tables
1041 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1042 Generate unwind tables that are exact at each instruction boundary.
1045 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1046 Generate auto-inc/dec instructions.
1049 Common Report Var(flag_auto_profile)
1050 Use sample profile information for call graph node weights. The default
1051 profile file is fbdata.afdo in 'pwd'.
1054 Common Joined RejectNegative Var(auto_profile_file)
1055 Use sample profile information for call graph node weights. The profile
1056 file is specified in the argument.
1058 ; -fcheck-bounds causes gcc to generate array bounds checks.
1059 ; For C, C++ and ObjC: defaults off.
1060 ; For Java: defaults to on.
1061 ; For Fortran: defaults to off.
1063 Common Report Var(flag_bounds_check)
1064 Generate code to check bounds before indexing arrays.
1067 Common Report Var(flag_branch_on_count_reg) Optimization
1068 Replace add, compare, branch with branch on count register.
1070 fbranch-probabilities
1071 Common Report Var(flag_branch_probabilities) Optimization
1072 Use profiling information for branch probabilities.
1074 fbranch-target-load-optimize
1075 Common Report Var(flag_branch_target_load_optimize) Optimization
1076 Perform branch target load optimization before prologue / epilogue threading.
1078 fbranch-target-load-optimize2
1079 Common Report Var(flag_branch_target_load_optimize2) Optimization
1080 Perform branch target load optimization after prologue / epilogue threading.
1083 Common Report Var(flag_btr_bb_exclusive) Optimization
1084 Restrict target load migration not to re-use registers in any basic block.
1087 Common Joined RejectNegative Var(common_deferred_options) Defer
1088 -fcall-saved-<register> Mark <register> as being preserved across functions.
1091 Common Joined RejectNegative Var(common_deferred_options) Defer
1092 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1094 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1095 ; be saved across function calls, if that produces overall better code.
1096 ; Optional now, so people can test it.
1098 Common Report Var(flag_caller_saves) Optimization
1099 Save registers around function calls.
1102 Common Report Var(flag_check_data_deps)
1103 This switch is deprecated; do not use.
1106 Common Var(flag_check_new)
1107 Check the return value of new in C++.
1110 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1111 Perform internal consistency checkings.
1114 Common Joined RejectNegative UInteger Var(flag_checking)
1115 Perform internal consistency checkings.
1118 Common Report Var(flag_code_hoisting) Optimization
1119 Enable code hoisting.
1121 fcombine-stack-adjustments
1122 Common Report Var(flag_combine_stack_adjustments) Optimization
1123 Looks for opportunities to reduce stack adjustments and stack references.
1126 Common Report Var(flag_no_common,0)
1127 Do not put uninitialized globals in the common section.
1131 ; Converted by the driver to -fcompare-debug= options.
1134 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1135 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1137 fcompare-debug-second
1138 Common Driver RejectNegative Var(flag_compare_debug)
1139 Run only the second compilation of -fcompare-debug.
1142 Common Report Var(flag_compare_elim_after_reload) Optimization
1143 Perform comparison elimination after register allocation has finished.
1146 Common Var(flag_conserve_stack) Optimization
1147 Do not perform optimizations increasing noticeably stack usage.
1150 Common Report Var(flag_cprop_registers) Optimization
1151 Perform a register copy-propagation optimization pass.
1154 Common Report Var(flag_crossjumping) Optimization
1155 Perform cross-jumping optimization.
1158 Common Report Var(flag_cse_follow_jumps) Optimization
1159 When running CSE, follow jumps to their targets.
1163 Does nothing. Preserved for backward compatibility.
1166 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1167 Omit range reduction step when performing complex division.
1170 Common Report Var(flag_cx_fortran_rules) Optimization
1171 Complex multiplication and division follow Fortran rules.
1174 Common Report Var(flag_data_sections)
1175 Place data items into their own section.
1178 Common Report Var(common_deferred_options) Defer
1179 List all available debugging counters with their limits and counts.
1182 Common RejectNegative Joined Var(common_deferred_options) Defer
1183 -fdbg-cnt=<counter>[:<lower_limit>]:<upper_limit>[,<counter>:...] Set the debug counter limit.
1186 Common Joined RejectNegative Var(common_deferred_options) Defer
1187 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1190 Common Joined RejectNegative Var(common_deferred_options) Defer
1191 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1193 fdebug-types-section
1194 Common Report Var(flag_debug_types_section) Init(0)
1195 Output .debug_types section when using DWARF v4 debuginfo.
1197 ; Nonzero for -fdefer-pop: don't pop args after each function call
1198 ; instead save them up to pop many calls' args with one insns.
1200 Common Report Var(flag_defer_pop) Optimization
1201 Defer popping functions args from stack until later.
1204 Common Report Var(flag_delayed_branch) Optimization
1205 Attempt to fill delay slots of branch instructions.
1207 fdelete-dead-exceptions
1208 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1209 Delete dead instructions that may throw exceptions.
1211 fdelete-null-pointer-checks
1212 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1213 Delete useless null pointer checks.
1215 fdevirtualize-at-ltrans
1216 Common Report Var(flag_ltrans_devirtualize)
1217 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1219 fdevirtualize-speculatively
1220 Common Report Var(flag_devirtualize_speculatively) Optimization
1221 Perform speculative devirtualization.
1224 Common Report Var(flag_devirtualize) Optimization
1225 Try to convert virtual calls to direct ones.
1227 fdiagnostics-show-location=
1228 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1229 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1231 ; Required for these enum values.
1236 Name(diagnostic_prefixing_rule) Type(int)
1239 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1242 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1244 fdiagnostics-show-caret
1245 Common Var(flag_diagnostics_show_caret) Init(1)
1246 Show the source line with a caret indicating the column.
1249 Common Alias(fdiagnostics-color=,always,never)
1253 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1254 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1256 ; Required for these enum values.
1261 Name(diagnostic_color_rule) Type(int)
1264 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1267 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1270 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1272 fdiagnostics-parseable-fixits
1273 Common Var(flag_diagnostics_parseable_fixits)
1274 Print fix-it hints in machine-readable form.
1276 fdiagnostics-generate-patch
1277 Common Var(flag_diagnostics_generate_patch)
1278 Print fix-it hints to stderr in unified diff format.
1280 fdiagnostics-show-option
1281 Common Var(flag_diagnostics_show_option) Init(1)
1282 Amend appropriate diagnostic messages with the command line option that controls them.
1285 Common Joined RejectNegative Var(common_deferred_options) Defer
1286 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1289 Common Joined RejectNegative Var(common_deferred_options) Defer
1290 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1293 Common Joined RejectNegative Var(common_deferred_options) Defer
1294 -fdump-<type> Dump various compiler internals to a file.
1297 Driver RejectNegative
1300 Common RejectNegative Joined Var(flag_dump_final_insns)
1301 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1304 Common RejectNegative Joined Var(flag_dump_go_spec)
1305 -fdump-go-spec=filename Write all declarations to file as Go code.
1308 Common Report Var(flag_dump_noaddr)
1309 Suppress output of addresses in debugging dumps.
1312 Common Driver Var(flag_report_bug)
1313 Collect and dump debug information into temporary file if ICE in C/C++
1316 fdump-internal-locations
1317 Common Var(flag_dump_locations) Init(0)
1318 Dump detailed information on GCC's internal representation of source code locations.
1321 Common Var(flag_dump_passes) Init(0)
1322 Dump optimization passes.
1325 Common Report Var(flag_dump_unnumbered)
1326 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1328 fdump-unnumbered-links
1329 Common Report Var(flag_dump_unnumbered_links)
1330 Suppress output of previous and next insn numbers in debugging dumps.
1333 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1334 Enable CFI tables via GAS assembler directives.
1337 Common Report Var(flag_early_inlining) Init(1) Optimization
1338 Perform early inlining.
1340 feliminate-dwarf2-dups
1342 Does nothing. Preserved for backward compatibility.
1345 Common Report Var(flag_ipa_sra) Init(0) Optimization
1346 Perform interprocedural reduction of aggregates.
1348 feliminate-unused-debug-symbols
1349 Common Report Var(flag_debug_only_used_symbols)
1350 Perform unused symbol elimination in debug info.
1352 feliminate-unused-debug-types
1353 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1354 Perform unused type elimination in debug info.
1356 femit-class-debug-always
1357 Common Report Var(flag_emit_class_debug_always) Init(0)
1358 Do not suppress C++ class debug information.
1361 Common Report Var(flag_exceptions) Optimization
1362 Enable exception handling.
1364 fexpensive-optimizations
1365 Common Report Var(flag_expensive_optimizations) Optimization
1366 Perform a number of minor, expensive optimizations.
1369 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1370 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1373 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1376 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1379 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1381 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1382 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1383 fpermitted-flt-eval-methods=
1384 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1385 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1388 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)
1391 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1394 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1400 Common Var(flag_fat_lto_objects)
1401 Output lto objects containing both the intermediate language and binary output.
1404 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1405 Assume no NaNs or infinities are generated.
1408 Common Joined RejectNegative Var(common_deferred_options) Defer
1409 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1412 Common Report Var(flag_float_store) Optimization
1413 Don't allocate floats and doubles in extended-precision registers.
1417 Does nothing. Preserved for backward compatibility.
1420 Common Report Var(flag_forward_propagate) Optimization
1421 Perform a forward propagation pass on RTL.
1424 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1425 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1428 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1431 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1433 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1435 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1438 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1440 ffp-int-builtin-inexact
1441 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1442 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1444 ; Nonzero means don't put addresses of constant functions in registers.
1445 ; Used for compiling the Unix kernel, where strange substitutions are
1446 ; done on the assembly output.
1448 Common Report Var(flag_no_function_cse,0) Optimization
1449 Allow function addresses to be held in registers.
1452 Common Report Var(flag_function_sections)
1453 Place each function into its own section.
1456 Common Report Var(flag_gcse) Optimization
1457 Perform global common subexpression elimination.
1460 Common Report Var(flag_gcse_lm) Init(1) Optimization
1461 Perform enhanced load motion during global common subexpression elimination.
1464 Common Report Var(flag_gcse_sm) Init(0) Optimization
1465 Perform store motion after global common subexpression elimination.
1468 Common Report Var(flag_gcse_las) Init(0) Optimization
1469 Perform redundant load after store elimination in global common subexpression
1473 Common Report Var(flag_gcse_after_reload) Optimization
1474 Perform global common subexpression elimination after register allocation has
1478 Name(dwarf_gnat_encodings) Type(int)
1481 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1484 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1487 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1490 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1491 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1493 ; This option is not documented yet as its semantics will change.
1495 Common Report Var(flag_graphite) Optimization
1496 Enable in and out of Graphite representation.
1499 Common Report Var(flag_graphite_identity) Optimization
1500 Enable Graphite Identity transformation.
1502 fhoist-adjacent-loads
1503 Common Report Var(flag_hoist_adjacent_loads) Optimization
1504 Enable hoisting adjacent loads to encourage generating conditional move
1508 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1509 ; Always keep a pointer to a live memory block
1511 floop-parallelize-all
1512 Common Report Var(flag_loop_parallelize_all) Optimization
1513 Mark all loops as parallel.
1516 Common Alias(floop-nest-optimize)
1517 Enable loop nest transforms. Same as -floop-nest-optimize.
1520 Common Report Var(flag_loop_interchange) Optimization
1521 Enable loop interchange on trees.
1524 Common Alias(floop-nest-optimize)
1525 Enable loop nest transforms. Same as -floop-nest-optimize.
1527 floop-unroll-and-jam
1528 Common Report Var(flag_unroll_jam) Optimization
1529 Perform unroll-and-jam on loops.
1532 Common Report Var(flag_tm)
1533 Enable support for GNU transactional memory.
1536 Common Report Var(flag_gnu_unique) Init(1)
1537 Use STB_GNU_UNIQUE if supported by the assembler.
1541 Does nothing. Preserved for backward compatibility.
1544 Common Report Var(flag_loop_nest_optimize) Optimization
1545 Enable the loop nest optimizer.
1547 fstrict-volatile-bitfields
1548 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1549 Force bitfield accesses to match their type width.
1552 Common Report Var(flag_store_merging) Optimization
1553 Merge adjacent stores.
1555 fguess-branch-probability
1556 Common Report Var(flag_guess_branch_prob) Optimization
1557 Enable guessing of branch probabilities.
1559 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1560 ; Generate position-independent code for executables if possible
1561 ; On SVR4 targets, it also controls whether or not to emit a
1562 ; string identifying the compiler.
1564 Common Report Var(flag_no_ident,0)
1565 Process #ident directives.
1568 Common Report Var(flag_if_conversion) Optimization
1569 Perform conversion of conditional jumps to branchless equivalents.
1572 Common Report Var(flag_if_conversion2) Optimization
1573 Perform conversion of conditional jumps to conditional execution.
1576 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1577 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1580 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1583 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1586 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1589 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1591 ftree-loop-if-convert
1592 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1593 Convert conditional jumps in innermost loops to branchless equivalents.
1595 ftree-loop-if-convert-stores
1597 Does nothing. Preserved for backward compatibility.
1599 ; -finhibit-size-directive inhibits output of .size for ELF.
1600 ; This is used only for compiling crtstuff.c,
1601 ; and it may be extended to other effects
1602 ; needed for crtstuff.c on other systems.
1603 finhibit-size-directive
1604 Common Report Var(flag_inhibit_size_directive)
1605 Do not generate .size directives.
1608 Common Report Var(flag_indirect_inlining) Optimization
1609 Perform indirect inlining.
1611 ; General flag to enable inlining. Specifying -fno-inline will disable
1612 ; all inlining apart from always-inline functions.
1614 Common Report Var(flag_no_inline,0) Init(0) Optimization
1615 Enable inlining of function declared \"inline\", disabling disables all inlining.
1617 finline-small-functions
1618 Common Report Var(flag_inline_small_functions) Optimization
1619 Integrate functions into their callers when code size is known not to grow.
1622 Common Report Var(flag_inline_functions) Optimization
1623 Integrate functions not declared \"inline\" into their callers when profitable.
1625 finline-functions-called-once
1626 Common Report Var(flag_inline_functions_called_once) Optimization
1627 Integrate functions only required by their single caller.
1630 Common RejectNegative Joined Alias(finline-limit=)
1633 Common RejectNegative Joined UInteger
1634 -finline-limit=<number> Limit the size of inlined functions to <number>.
1637 Common Report Var(flag_inline_atomics) Init(1) Optimization
1638 Inline __atomic operations when a lock free instruction sequence is available.
1641 Common RejectNegative Alias(fcf-protection=,full)
1644 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1645 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1646 instructions have valid targets.
1649 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1652 Enum(cf_protection_level) String(full) Value(CF_FULL)
1655 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1658 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1661 Enum(cf_protection_level) String(none) Value(CF_NONE)
1663 finstrument-functions
1664 Common Report Var(flag_instrument_function_entry_exit)
1665 Instrument function entry and exit with profiling calls.
1667 finstrument-functions-exclude-function-list=
1668 Common RejectNegative Joined
1669 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1671 finstrument-functions-exclude-file-list=
1672 Common RejectNegative Joined
1673 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1676 Common Report Var(flag_ipa_cp) Optimization
1677 Perform interprocedural constant propagation.
1680 Common Report Var(flag_ipa_cp_clone) Optimization
1681 Perform cloning to make Interprocedural constant propagation stronger.
1685 Does nothing. Preserved for backward compatibility.
1688 Common Report Var(flag_ipa_bit_cp) Optimization
1689 Perform interprocedural bitwise constant propagation.
1692 Common Report Var(flag_ipa_profile) Init(0) Optimization
1693 Perform interprocedural profile propagation.
1696 Common Report Var(flag_ipa_pta) Init(0) Optimization
1697 Perform interprocedural points-to analysis.
1700 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1701 Discover pure and const functions.
1704 Common Report Var(flag_ipa_icf) Optimization
1705 Perform Identical Code Folding for functions and read-only variables.
1708 Common Report Var(flag_ipa_icf_functions) Optimization
1709 Perform Identical Code Folding for functions.
1712 Common Report Var(flag_ipa_icf_variables) Optimization
1713 Perform Identical Code Folding for variables.
1716 Common Report Var(flag_ipa_reference) Init(0) Optimization
1717 Discover readonly and non addressable static variables.
1721 Does nothing. Preserved for backward compatibility.
1725 Does nothing. Preserved for backward compatibility.
1728 Common Report Var(flag_ipa_vrp) Optimization
1729 Perform IPA Value Range Propagation.
1732 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1733 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1736 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1739 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1742 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1745 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1746 -fira-region=[one|all|mixed] Set regions for IRA.
1749 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1752 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1755 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1758 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1761 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1762 Use IRA based register pressure calculation
1763 in RTL hoist optimizations.
1766 Common Report Var(flag_ira_loop_pressure) Optimization
1767 Use IRA based register pressure calculation
1768 in RTL loop optimizations.
1770 fira-share-save-slots
1771 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1772 Share slots for saving different hard registers.
1774 fira-share-spill-slots
1775 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1776 Share stack slots for spilled pseudo-registers.
1779 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1780 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1783 Common Report Var(flag_ivopts) Init(1) Optimization
1784 Optimize induction variables on trees.
1787 Common Var(flag_jump_tables) Init(1) Optimization
1788 Use jump tables for sufficiently large switch statements.
1790 fkeep-inline-functions
1791 Common Report Var(flag_keep_inline_functions)
1792 Generate code for functions even if they are fully inlined.
1794 fkeep-static-functions
1795 Common Report Var(flag_keep_static_functions)
1796 Generate code for static functions even if they are never called.
1799 Common Report Var(flag_keep_static_consts) Init(1)
1800 Emit static const variables even if they are not used.
1803 Common Report Var(flag_leading_underscore) Init(-1)
1804 Give external symbols a leading underscore.
1808 Does nothing. Preserved for backward compatibility.
1811 Common Report Var(flag_lra_remat) Optimization
1812 Do CFG-sensitive rematerialization in LRA.
1816 Enable link-time optimization.
1819 Common RejectNegative Joined Var(flag_lto)
1820 Link-time optimization with number of parallel jobs or jobserver.
1823 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1826 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1829 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1832 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1835 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1838 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1841 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1842 Specify the algorithm to partition symbols and vars at linktime.
1844 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1845 flto-compression-level=
1846 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1847 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1849 flto-odr-type-merging
1850 Common Report Var(flag_lto_odr_type_mering) Init(1)
1851 Merge C++ types using One Definition Rule.
1854 Common Report Var(flag_lto_report) Init(0)
1855 Report various link-time optimization statistics.
1858 Common Report Var(flag_lto_report_wpa) Init(0)
1859 Report various link-time optimization statistics for WPA only.
1862 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1863 Set errno after built-in math functions.
1866 Common Joined RejectNegative UInteger Var(flag_max_errors)
1867 -fmax-errors=<number> Maximum number of errors to report.
1870 Common Report Var(mem_report)
1871 Report on permanent memory allocation.
1874 Common Report Var(mem_report_wpa)
1875 Report on permanent memory allocation in WPA only.
1877 ; This will attempt to merge constant section constants, if 1 only
1878 ; string constants and constants from constant pool, if 2 also constant
1880 fmerge-all-constants
1881 Common Report Var(flag_merge_constants,2) Init(1)
1882 Attempt to merge identical constants and constant variables.
1885 Common Report Var(flag_merge_constants,1)
1886 Attempt to merge identical constants across compilation units.
1888 fmerge-debug-strings
1889 Common Report Var(flag_merge_debug_strings) Init(1)
1890 Attempt to merge identical debug strings across compilation units.
1893 Common RejectNegative Joined UInteger
1894 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1897 Common Report Var(flag_modulo_sched) Optimization
1898 Perform SMS based modulo scheduling before the first scheduling pass.
1900 fmodulo-sched-allow-regmoves
1901 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1902 Perform SMS based modulo scheduling with register moves allowed.
1904 fmove-loop-invariants
1905 Common Report Var(flag_move_loop_invariants) Optimization
1906 Move loop invariant computations out of loops.
1909 Common Var(flag_dce) Init(1) Optimization
1910 Use the RTL dead code elimination pass.
1913 Common Var(flag_dse) Init(1) Optimization
1914 Use the RTL dead store elimination pass.
1916 freschedule-modulo-scheduled-loops
1917 Common Report Var(flag_resched_modulo_sched) Optimization
1918 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1920 fnon-call-exceptions
1921 Common Report Var(flag_non_call_exceptions) Optimization
1922 Support synchronous non-call exceptions.
1925 Common Driver Joined MissingArgError(options or targets missing after %qs)
1926 -foffload=<targets>=<options> Specify offloading targets and options for them.
1929 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1930 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1933 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1936 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1939 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1942 Common Report Var(flag_omit_frame_pointer) Optimization
1943 When possible do not generate stack frames.
1946 Common Report Var(flag_opt_info) Optimization
1947 Enable all optimization info dumps on stderr.
1950 Common Joined RejectNegative Var(common_deferred_options) Defer
1951 -fopt-info[-<type>=filename] Dump compiler optimization details.
1953 foptimize-register-move
1955 Does nothing. Preserved for backward compatibility.
1957 foptimize-sibling-calls
1958 Common Report Var(flag_optimize_sibling_calls) Optimization
1959 Optimize sibling and tail recursive calls.
1962 Common Report Var(flag_partial_inlining) Optimization
1963 Perform partial inlining.
1966 Common Report Var(pre_ipa_mem_report)
1967 Report on memory allocation before interprocedural optimization.
1969 fpost-ipa-mem-report
1970 Common Report Var(post_ipa_mem_report)
1971 Report on memory allocation before interprocedural optimization.
1974 Common Report Var(flag_pack_struct) Optimization
1975 Pack structure members together without holes.
1978 Common RejectNegative Joined UInteger Optimization
1979 -fpack-struct=<number> Set initial maximum structure member alignment.
1982 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1983 Return small aggregates in memory, not registers.
1986 Common Report Var(flag_peel_loops) Optimization
1987 Perform loop peeling.
1990 Common Report Var(flag_no_peephole,0) Optimization
1991 Enable machine specific peephole optimizations.
1994 Common Report Var(flag_peephole2) Optimization
1995 Enable an RTL peephole pass before sched2.
1998 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1999 Generate position-independent code if possible (large mode).
2002 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
2003 Generate position-independent code for executables if possible (large mode).
2006 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
2007 Generate position-independent code if possible (small mode).
2010 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2011 Generate position-independent code for executables if possible (small mode).
2014 Common Report Var(flag_plt) Init(1) Optimization
2015 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2018 Common Joined RejectNegative Var(common_deferred_options) Defer
2019 Specify a plugin to load.
2022 Common Joined RejectNegative Var(common_deferred_options) Defer
2023 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2025 fpredictive-commoning
2026 Common Report Var(flag_predictive_commoning) Optimization
2027 Run predictive commoning optimization.
2029 fprefetch-loop-arrays
2030 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2031 Generate prefetch instructions, if available, for arrays in loops.
2034 Common Report Var(profile_flag)
2035 Enable basic program profiling code.
2038 Common Report Var(profile_abs_path_flag)
2039 Generate absolute source path names for gcov.
2042 Common Report Var(profile_arc_flag)
2043 Insert arc-based program profiling code.
2046 Common Joined RejectNegative Var(profile_data_prefix)
2047 Set the top-level directory for storing the profile data.
2048 The default is 'pwd'.
2051 Common Report Var(flag_profile_correction)
2052 Enable correction of flow inconsistent profile data input.
2055 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2056 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2059 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2062 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2065 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2068 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2072 Enable common options for generating profile info for profile feedback directed optimizations.
2075 Common Joined RejectNegative
2076 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2079 Common Var(flag_profile_use)
2080 Enable common options for performing profile feedback directed optimizations.
2083 Common Joined RejectNegative
2084 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2087 Common Report Var(flag_profile_values)
2088 Insert code to profile values of expressions.
2091 Common Report Var(profile_report)
2092 Report on consistency of profile.
2094 fprofile-reorder-functions
2095 Common Report Var(flag_profile_reorder_functions)
2096 Enable function reordering that improves code placement.
2098 fpatchable-function-entry=
2099 Common Joined Optimization
2100 Insert NOP instructions at each function entry.
2103 Common Var(common_deferred_options) Defer
2106 Common Joined RejectNegative Var(common_deferred_options) Defer
2107 -frandom-seed=<string> Make compile reproducible using <string>.
2109 ; This switch causes the command line that was used to create an
2110 ; object file to be recorded into the object file. The exact format
2111 ; of this recording is target and binary file format dependent.
2112 ; It is related to the -fverbose-asm switch, but that switch only
2113 ; records information in the assembler output file as comments, so
2114 ; they never reach the object file.
2115 frecord-gcc-switches
2116 Common Report Var(flag_record_gcc_switches)
2117 Record gcc command line switches in the object file.
2120 Common Report Var(flag_pcc_struct_return,0) Optimization
2121 Return small aggregates in registers.
2125 Does nothing. Preserved for backward compatibility.
2128 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2129 Tell DSE that the storage for a C++ object is dead when the constructor
2130 starts and when the destructor finishes.
2133 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2135 flive-range-shrinkage
2136 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2137 Relief of register pressure through live range shrinkage.
2140 Common Report Var(flag_rename_registers) Init(2) Optimization
2141 Perform a register renaming optimization pass.
2144 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2145 Perform a target dependent instruction fusion optimization pass.
2148 Common Report Var(flag_reorder_blocks) Optimization
2149 Reorder basic blocks to improve code placement.
2151 freorder-blocks-algorithm=
2152 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2153 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2156 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2159 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2162 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2164 freorder-blocks-and-partition
2165 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2166 Reorder basic blocks and partition into hot and cold sections.
2169 Common Report Var(flag_reorder_functions) Optimization
2170 Reorder functions to improve code placement.
2172 frerun-cse-after-loop
2173 Common Report Var(flag_rerun_cse_after_loop) Optimization
2174 Add a common subexpression elimination pass after loop optimizations.
2178 Does nothing. Preserved for backward compatibility.
2181 Common Report Var(flag_rounding_math) Optimization SetByCombined
2182 Disable optimizations that assume default FP rounding behavior.
2185 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2186 Enable scheduling across basic blocks.
2189 Common Report Var(flag_sched_pressure) Init(0) Optimization
2190 Enable register pressure sensitive insn scheduling.
2193 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2194 Allow speculative motion of non-loads.
2197 Common Report Var(flag_schedule_speculative_load) Optimization
2198 Allow speculative motion of some loads.
2200 fsched-spec-load-dangerous
2201 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2202 Allow speculative motion of more loads.
2205 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2206 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2208 fsched2-use-superblocks
2209 Common Report Var(flag_sched2_use_superblocks) Optimization
2210 If scheduling post reload, do superblock scheduling.
2214 Does nothing. Preserved for backward compatibility.
2217 Common Report Var(flag_schedule_insns) Optimization
2218 Reschedule instructions before register allocation.
2221 Common Report Var(flag_schedule_insns_after_reload) Optimization
2222 Reschedule instructions after register allocation.
2224 ; This flag should be on when a target implements non-trivial
2225 ; scheduling hooks, maybe saving some information for its own sake.
2226 ; On IA64, for example, this is used for correct bundling.
2227 fselective-scheduling
2228 Common Report Var(flag_selective_scheduling) Optimization
2229 Schedule instructions using selective scheduling algorithm.
2231 fselective-scheduling2
2232 Common Report Var(flag_selective_scheduling2) Optimization
2233 Run selective scheduling after reload.
2236 Common Undocumented Joined Var(flag_self_test)
2237 Run self-tests, using the given path to locate test files.
2239 fsel-sched-pipelining
2240 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2241 Perform software pipelining of inner loops during selective scheduling.
2243 fsel-sched-pipelining-outer-loops
2244 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2245 Perform software pipelining of outer loops during selective scheduling.
2247 fsel-sched-reschedule-pipelined
2248 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2249 Reschedule pipelined regions without pipelining.
2251 fsemantic-interposition
2252 Common Report Var(flag_semantic_interposition) Init(1)
2253 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2255 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2256 ; of stalled insns into the ready list.
2257 fsched-stalled-insns
2258 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2259 Allow premature scheduling of queued insns.
2261 fsched-stalled-insns=
2262 Common RejectNegative Joined UInteger Optimization
2263 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2265 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2266 ; be examined for a dependency on a stalled insn that is candidate for
2267 ; premature removal from the queue of stalled insns into the ready list (has
2268 ; an effect only if the flag 'sched_stalled_insns' is set).
2269 fsched-stalled-insns-dep
2270 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2271 Set dependence distance checking in premature scheduling of queued insns.
2273 fsched-stalled-insns-dep=
2274 Common RejectNegative Joined UInteger Optimization
2275 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2277 fsched-group-heuristic
2278 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2279 Enable the group heuristic in the scheduler.
2281 fsched-critical-path-heuristic
2282 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2283 Enable the critical path heuristic in the scheduler.
2285 fsched-spec-insn-heuristic
2286 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2287 Enable the speculative instruction heuristic in the scheduler.
2289 fsched-rank-heuristic
2290 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2291 Enable the rank heuristic in the scheduler.
2293 fsched-last-insn-heuristic
2294 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2295 Enable the last instruction heuristic in the scheduler.
2297 fsched-dep-count-heuristic
2298 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2299 Enable the dependent count heuristic in the scheduler.
2302 Common Report Var(flag_section_anchors) Optimization
2303 Access data in the same section from shared anchor points.
2307 Does nothing. Preserved for backward compatibility.
2311 Does nothing. Preserved for backward compatibility.
2314 Common Report Var(flag_ree) Init(0)
2315 Turn on Redundant Extensions Elimination pass.
2318 Common Report Var(flag_show_column) Init(1)
2319 Show column numbers in diagnostics, when available. Default on.
2322 Common Report Var(flag_shrink_wrap) Optimization
2323 Emit function prologues only before parts of the function that need it,
2324 rather than at the top of the function.
2326 fshrink-wrap-separate
2327 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2328 Shrink-wrap parts of the prologue and epilogue separately.
2331 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2332 Disable optimizations observable by IEEE signaling NaNs.
2335 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2336 Disable floating point optimizations that ignore the IEEE signedness of zero.
2338 fsingle-precision-constant
2339 Common Report Var(flag_single_precision_constant) Optimization
2340 Convert floating point constants to single precision constants.
2342 fsplit-ivs-in-unroller
2343 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2344 Split lifetimes of induction variables when loops are unrolled.
2347 Common Report Var(flag_split_stack) Init(-1)
2348 Generate discontiguous stack frames.
2351 Common Report Var(flag_split_wide_types) Optimization
2352 Split wide types into independent registers.
2355 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2356 Enable backward propagation of use properties at the SSA level.
2359 Common Report Var(flag_ssa_phiopt) Optimization
2360 Optimize conditional patterns using SSA PHI nodes.
2363 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2364 Optimize amount of stdarg registers saved to stack at start of function.
2366 fvariable-expansion-in-unroller
2367 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2368 Apply variable expansion when loops are unrolled.
2371 Common Report RejectNegative Joined Optimization
2372 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2375 Common Alias(fstack-check=, specific, no)
2376 Insert stack checking code into the program. Same as -fstack-check=specific.
2378 fstack-clash-protection
2379 Common Report Var(flag_stack_clash_protection) Optimization
2380 Insert code to probe each page of stack space as it is allocated to protect
2381 from stack-clash style attacks.
2384 Common Var(common_deferred_options) Defer
2386 fstack-limit-register=
2387 Common RejectNegative Joined Var(common_deferred_options) Defer
2388 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2390 fstack-limit-symbol=
2391 Common RejectNegative Joined Var(common_deferred_options) Defer
2392 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2395 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2396 Use propolice as a stack protection method.
2398 fstack-protector-all
2399 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2400 Use a stack protection method for every function.
2402 fstack-protector-strong
2403 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2404 Use a smart stack protection method for certain functions.
2406 fstack-protector-explicit
2407 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2408 Use stack protection method only for functions with the stack_protect attribute.
2411 Common RejectNegative Var(flag_stack_usage)
2412 Output stack usage information on a per-function basis.
2416 Does nothing. Preserved for backward compatibility.
2418 ; Nonzero if we should do (language-dependent) alias analysis.
2419 ; Typically, this analysis will assume that expressions of certain
2420 ; types do not alias expressions of certain other types. Only used
2421 ; if alias analysis (in general) is enabled.
2423 Common Report Var(flag_strict_aliasing) Optimization
2424 Assume strict aliasing rules apply.
2428 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2431 Common Report Var(flag_sync_libcalls) Init(1)
2432 Implement __atomic operations via libcalls to legacy __sync functions.
2435 Common Report Var(flag_syntax_only)
2436 Check for syntax errors, then stop.
2439 Common Report Var(flag_test_coverage)
2440 Create data files needed by \"gcov\".
2443 Common Report Var(flag_thread_jumps) Optimization
2444 Perform jump threading optimizations.
2447 Common Report Var(time_report)
2448 Report the time taken by each compiler pass.
2450 ftime-report-details
2451 Common Report Var(time_report_details)
2452 Record times taken by sub-phases separately.
2455 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2456 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2459 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2462 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2465 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2468 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2471 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2474 Common Report Var(flag_toplevel_reorder) Init(2)
2475 Reorder top level functions, variables, and asms.
2478 Common Report Var(flag_tracer) Optimization
2479 Perform superblock formation via tail duplication.
2482 Common Report Var(flag_trampolines) Init(0)
2483 For targets that normally need trampolines for nested functions, always
2484 generate them instead of using descriptors.
2486 ; Zero means that floating-point math operations cannot generate a
2487 ; (user-visible) trap. This is the case, for example, in nonstop
2488 ; IEEE 754 arithmetic.
2490 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2491 Assume floating-point operations can trap.
2494 Common Report Var(flag_trapv) Optimization
2495 Trap for signed overflow in addition, subtraction and multiplication.
2498 Common Report Var(flag_tree_ccp) Optimization
2499 Enable SSA-CCP optimization on trees.
2502 Common Report Var(flag_tree_bit_ccp) Optimization
2503 Enable SSA-BIT-CCP optimization on trees.
2507 Does nothing. Preserved for backward compatibility.
2510 Common Report Var(flag_tree_ch) Optimization
2511 Enable loop header copying on trees.
2513 ftree-coalesce-inlined-vars
2514 Common Ignore RejectNegative
2515 Does nothing. Preserved for backward compatibility.
2518 Common Report Var(flag_tree_coalesce_vars) Optimization
2519 Enable SSA coalescing of user variables.
2523 Does nothing. Preserved for backward compatibility.
2526 Common Report Var(flag_tree_copy_prop) Optimization
2527 Enable copy propagation on trees.
2529 ftree-store-copy-prop
2531 Does nothing. Preserved for backward compatibility.
2534 Common Report Var(flag_tree_cselim) Init(2) Optimization
2535 Transform condition stores into unconditional ones.
2537 ftree-switch-conversion
2538 Common Report Var(flag_tree_switch_conversion) Optimization
2539 Perform conversions of switch initializations.
2542 Common Report Var(flag_tree_dce) Optimization
2543 Enable SSA dead code elimination optimization on trees.
2545 ftree-dominator-opts
2546 Common Report Var(flag_tree_dom) Optimization
2547 Enable dominator optimizations.
2550 Common Report Var(flag_tree_tail_merge) Optimization
2551 Enable tail merging on trees.
2554 Common Report Var(flag_tree_dse) Optimization
2555 Enable dead store elimination.
2558 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2559 Enable forward propagation on trees.
2562 Common Report Var(flag_tree_fre) Optimization
2563 Enable Full Redundancy Elimination (FRE) on trees.
2566 Common Report Var(flag_optimize_strlen) Optimization
2567 Enable string length optimizations on trees.
2569 fisolate-erroneous-paths-dereference
2570 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2571 Detect paths that trigger erroneous or undefined behavior due to
2572 dereferencing a null pointer. Isolate those paths from the main control
2573 flow and turn the statement with erroneous or undefined behavior into a trap.
2575 fisolate-erroneous-paths-attribute
2576 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2577 Detect paths that trigger erroneous or undefined behavior due to a null value
2578 being used in a way forbidden by a returns_nonnull or nonnull
2579 attribute. Isolate those paths from the main control flow and turn the
2580 statement with erroneous or undefined behavior into a trap.
2582 ftree-loop-distribution
2583 Common Report Var(flag_tree_loop_distribution) Optimization
2584 Enable loop distribution on trees.
2586 ftree-loop-distribute-patterns
2587 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2588 Enable loop distribution for patterns transformed into a library call.
2591 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2592 Enable loop invariant motion on trees.
2595 Common Alias(floop-nest-optimize)
2596 Enable loop nest transforms. Same as -floop-nest-optimize.
2599 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2600 Create canonical induction variables in loops.
2603 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2604 Enable loop optimizations on tree level.
2606 ftree-parallelize-loops=
2607 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2608 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2611 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2612 Enable hoisting loads from conditional pointers.
2615 Common Report Var(flag_tree_pre) Optimization
2616 Enable SSA-PRE optimization on trees.
2619 Common Report Var(flag_tree_partial_pre) Optimization
2620 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2623 Common Report Var(flag_tree_pta) Optimization
2624 Perform function-local points-to analysis on trees.
2627 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2628 Enable reassociation on tree level.
2632 Does nothing. Preserved for backward compatibility.
2635 Common Report Var(flag_tree_sink) Optimization
2636 Enable SSA code sinking on trees.
2639 Common Report Var(flag_tree_slsr) Optimization
2640 Perform straight-line strength reduction.
2643 Common Report Var(flag_tree_sra) Optimization
2644 Perform scalar replacement of aggregates.
2647 Common Report Var(flag_tree_ter) Optimization
2648 Replace temporary expressions in the SSA->normal pass.
2651 Common Report Var(flag_tree_live_range_split) Optimization
2652 Perform live range splitting during the SSA->normal pass.
2655 Common Report Var(flag_tree_vrp) Init(0) Optimization
2656 Perform Value Range Propagation on trees.
2659 Common Report Var(flag_split_paths) Init(0) Optimization
2660 Split paths leading to loop backedges.
2662 funconstrained-commons
2663 Common Var(flag_unconstrained_commons) Optimization
2664 Assume common declarations may be overridden with ones with a larger
2668 Common Report Var(flag_unit_at_a_time) Init(1)
2669 Compile whole compilation unit at a time.
2672 Common Report Var(flag_unroll_loops) Optimization
2673 Perform loop unrolling when iteration count is known.
2676 Common Report Var(flag_unroll_all_loops) Optimization
2677 Perform loop unrolling for all loops.
2679 ; Nonzero means that loop optimizer may assume that the induction variables
2680 ; that control loops do not overflow and that the loops with nontrivial
2681 ; exit condition are not infinite
2682 funsafe-loop-optimizations
2684 Does nothing. Preserved for backward compatibility.
2687 Common Report Var(flag_associative_math) SetByCombined Optimization
2688 Allow optimization for floating-point arithmetic which may change the
2689 result of the operation due to rounding.
2692 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2693 Same as -fassociative-math for expressions which include division.
2695 ; Nonzero means that unsafe floating-point math optimizations are allowed
2696 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2697 ; are allowed to assume that their arguments and results are "normal"
2698 ; (e.g., nonnegative for SQRT).
2699 funsafe-math-optimizations
2700 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2701 Allow math optimizations that may violate IEEE or ISO standards.
2704 Common Report Var(flag_unswitch_loops) Optimization
2705 Perform loop unswitching.
2708 Common Report Var(flag_split_loops) Optimization
2709 Perform loop splitting.
2712 Common Report Var(flag_unwind_tables) Optimization
2713 Just generate unwind tables for exception handling.
2716 Common Driver Negative(fuse-ld=gold)
2717 Use the bfd linker instead of the default linker.
2720 Common Driver Negative(fuse-ld=bfd)
2721 Use the gold linker instead of the default linker.
2724 Common Undocumented Var(flag_use_linker_plugin)
2726 ; Positive if we should track variables, negative if we should run
2727 ; the var-tracking pass only to discard debug annotations, zero if
2728 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2729 ; will be set according to optimize, debug_info_level and debug_hooks
2730 ; in process_options ().
2732 Common Report Var(flag_var_tracking) Init(2) PerFunction
2733 Perform variable tracking.
2735 ; Positive if we should track variables at assignments, negative if
2736 ; we should run the var-tracking pass only to discard debug
2737 ; annotations. When flag_var_tracking_assignments ==
2738 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2739 fvar-tracking-assignments
2740 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2741 Perform variable tracking by annotating assignments.
2743 ; Nonzero if we should toggle flag_var_tracking_assignments after
2744 ; processing options and computing its default. */
2745 fvar-tracking-assignments-toggle
2746 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2747 Toggle -fvar-tracking-assignments.
2749 ; Positive if we should track uninitialized variables, negative if
2750 ; we should run the var-tracking pass only to discard debug
2751 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2752 ; will be set according to flag_var_tracking.
2753 fvar-tracking-uninit
2754 Common Report Var(flag_var_tracking_uninit) PerFunction
2755 Perform variable tracking and also tag variables that are uninitialized.
2757 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2759 Common Report Optimization
2760 Enable vectorization on trees.
2762 ftree-vectorizer-verbose=
2763 Common Joined RejectNegative Ignore
2764 Does nothing. Preserved for backward compatibility.
2766 ftree-loop-vectorize
2767 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2768 Enable loop vectorization on trees.
2771 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2772 Enable basic block vectorization (SLP) on trees.
2775 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2776 Specifies the cost model for vectorization.
2777 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2780 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2781 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2784 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2787 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2790 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2793 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2796 Common Alias(fvect-cost-model=,dynamic,unlimited)
2797 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2799 ftree-vect-loop-version
2801 Does nothing. Preserved for backward compatibility.
2804 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2805 Enable copy propagation of scalar-evolution information.
2807 ; -fverbose-asm causes extra commentary information to be produced in
2808 ; the generated assembly code (to make it more readable). This option
2809 ; is generally only of use to those who actually need to read the
2810 ; generated assembly code (perhaps while debugging the compiler itself).
2811 ; -fno-verbose-asm, the default, causes the extra information
2812 ; to not be added and is useful when comparing two assembler files.
2814 Common Report Var(flag_verbose_asm)
2815 Add extra commentary to assembler output.
2818 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2819 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2822 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2825 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2828 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2831 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2834 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2837 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2838 Validate vtable pointers before using them.
2841 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2844 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2847 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2850 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2853 Common Var(flag_vtv_counts)
2854 Output vtable verification counters.
2857 Common Var(flag_vtv_debug)
2858 Output vtable verification pointer sets information.
2861 Common Report Var(flag_value_profile_transformations) Optimization
2862 Use expression value profiles in optimizations.
2865 Common Report Var(flag_web) Init(2) Optimization
2866 Construct webs and split unrelated uses of single variable.
2868 ftree-builtin-call-dce
2869 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2870 Enable conditional dead code elimination for builtin calls.
2873 Common Report Var(flag_whole_program) Init(0)
2874 Perform whole program optimizations.
2877 Common Report Var(flag_wrapv_pointer) Optimization
2878 Assume pointer overflow wraps around.
2881 Common Report Var(flag_wrapv) Optimization
2882 Assume signed arithmetic overflow wraps around.
2884 fzero-initialized-in-bss
2885 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2886 Put zero initialized data in the bss section.
2889 Common Driver RejectNegative JoinedOrMissing
2890 Generate debug information in default format.
2893 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2894 Assume assembler support for (DWARF2+) .loc directives
2897 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2898 Assume assembler support for view in (DWARF2+) .loc directives
2901 Common Driver Ignore Warn(switch %qs no longer supported)
2902 Does nothing. Preserved for backward compatibility.
2905 Common Driver Ignore Warn(switch %qs no longer supported)
2906 Does nothing. Preserved for backward compatibility.
2909 Common Driver Ignore Warn(switch %qs no longer supported)
2910 Does nothing. Preserved for backward compatibility.
2913 Common Driver Ignore Warn(switch %qs no longer supported)
2914 Does nothing. Preserved for backward compatibility.
2917 Common Driver Var(debug_column_info,1) Init(1)
2918 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2921 Common Driver JoinedOrMissing Negative(gdwarf-)
2922 Generate debug information in default version of DWARF format.
2925 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2926 Generate debug information in DWARF v2 (or later) format.
2929 Common Driver JoinedOrMissing
2930 Generate debug information in default extended format.
2933 Common Driver Var(debug_inline_points) Init(2)
2934 Generate extended entry point information for inlined functions
2936 ginternal-reset-location-views
2937 Common Driver Var(debug_internal_reset_location_views) Init(2)
2938 Compute locview reset points based on insn length estimates
2941 RejectNegative Joined Undocumented
2942 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
2945 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2946 Don't generate DWARF pubnames and pubtypes sections.
2949 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2950 Generate DWARF pubnames and pubtypes sections.
2953 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2954 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2956 grecord-gcc-switches
2957 Common Driver Var(dwarf_record_gcc_switches) Init(1)
2958 Record gcc command line switches in DWARF DW_AT_producer.
2961 Common Driver Var(dwarf_split_debug_info) Init(0)
2962 Generate debug information in separate .dwo files.
2965 Common Driver JoinedOrMissing Negative(gstabs+)
2966 Generate debug information in STABS format.
2969 Common Driver JoinedOrMissing Negative(gvms)
2970 Generate debug information in extended STABS format.
2972 gstatement-frontiers
2973 Common Driver Var(debug_nonbind_markers_p) Init(2)
2974 Emit progressive recommended breakpoint locations.
2977 Common Driver Report Var(dwarf_strict) Init(0)
2978 Don't emit DWARF additions beyond selected version.
2981 Common Driver Report Var(flag_gtoggle)
2982 Toggle debug information generation.
2984 gvariable-location-views
2985 Common Driver Var(debug_variable_location_views, 1) Init(2)
2986 Augment variable location lists with progressive views.
2988 gvariable-location-views=incompat5
2989 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
2992 Common Driver JoinedOrMissing Negative(gxcoff)
2993 Generate debug information in VMS format.
2996 Common Driver JoinedOrMissing Negative(gxcoff+)
2997 Generate debug information in XCOFF format.
3000 Common Driver JoinedOrMissing Negative(gdwarf)
3001 Generate debug information in extended XCOFF format.
3004 Name(compressed_debug_sections) Type(int)
3006 ; Since -gz= is completely handled in specs, the values aren't used and we
3007 ; assign arbitrary constants.
3009 Enum(compressed_debug_sections) String(none) Value(0)
3012 Enum(compressed_debug_sections) String(zlib) Value(1)
3015 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3019 Generate compressed debug sections.
3022 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3023 -gz=<format> Generate compressed debug sections in format <format>.
3026 Driver Joined Separate
3029 Common Joined Var(plugindir_string) Init(0)
3030 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3033 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3034 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3037 Driver Joined Separate
3042 no-canonical-prefixes
3055 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3056 -o <file> Place output into <file>.
3059 Common Var(profile_flag)
3060 Enable function profiling.
3063 Driver Var(pass_exit_codes)
3066 Common Alias(Wpedantic)
3069 Common Var(flag_pedantic_errors)
3070 Like -pedantic but issue them as errors.
3076 Driver Var(use_pipes)
3079 Driver JoinedOrMissing Var(print_file_name)
3081 print-libgcc-file-name
3084 print-multi-directory
3085 Driver Var(print_multi_directory)
3088 Driver Var(print_multi_lib)
3090 print-multi-os-directory
3091 Driver Var(print_multi_os_directory)
3094 Driver Var(print_multiarch)
3097 Driver JoinedOrMissing Var(print_prog_name)
3100 Driver Var(print_search_dirs)
3103 Driver Var(print_sysroot)
3105 print-sysroot-headers-suffix
3106 Driver Var(print_sysroot_headers_suffix)
3109 Common Var(quiet_flag) RejectDriver
3110 Do not display functions compiled or elapsed time.
3128 Driver Var(report_times)
3131 Driver JoinedOrMissing
3134 Driver Joined Separate
3138 ; C option, but driver must not handle as "-u ndef".
3141 Common Driver Var(verbose_flag)
3142 Enable verbose output.
3145 Common Var(version_flag) RejectDriver
3146 Display the compiler's version.
3149 Common Var(inhibit_warnings)
3153 Driver Separate Var(wrapper_string)
3156 Driver Joined Separate
3159 Driver RejectNegative Negative(static-pie)
3160 Create a shared library.
3166 Driver Separate Alias(specs=)
3179 ; Documented for Fortran, but always accepted by driver.
3186 ; Documented for Go, but always accepted by driver.
3204 Driver RejectNegative Negative(shared)
3205 Don't create a dynamically linked position independent executable.
3208 Driver RejectNegative Negative(no-pie)
3209 Create a dynamically linked position independent executable.
3212 Driver RejectNegative Negative(pie)
3213 Create a static position independent executable.
3216 Driver Joined Separate
3219 Common Report Var(flag_ipa_ra) Optimization
3220 Use caller save register across calls if possible.
3222 ; This comment is to ensure we retain the blank line above.