1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2016 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.
167 ; Balance between GNAT encodings and standard DWARF to emit.
169 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
171 ; -dP causes the rtl to be emitted as a comment in assembly.
173 int flag_dump_rtl_in_asm
175 ; Whether -da was passed (used only in handle_common_deferred_options).
177 bool flag_dump_all_passed
179 ; Other flags saying which kinds of debugging dump have been requested.
182 int rtl_dump_and_exit
185 int flag_print_asm_name
187 ; Name of top-level original source file (what was input to cpp).
188 ; This comes from the #-command at the beginning of the actual input.
189 ; If there isn't any there, then this is the cc1 input file name.
191 const char *main_input_filename
193 ; Pointer to base name in main_input_filename, with directories and a
194 ; single final extension removed, and the length of this base
198 const char *main_input_basename
201 int main_input_baselength
203 ; Which options have been printed by --help.
207 ; Which enums have been printed by --help. 0 = not printed, no
208 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
211 char *help_enum_printed
213 ; The number of columns for --help output.
215 unsigned int help_columns
217 ; Whether this options structure has been through finish_options
219 bool flag_opts_finished
221 ; What the sanitizer should instrument
223 unsigned int flag_sanitize
225 ; What sanitizers should recover from errors
227 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
229 fsanitize-coverage=trace-pc
230 Common Report Var(flag_sanitize_coverage)
231 Enable coverage-guided fuzzing code instrumentation.
232 Inserts call to __sanitizer_cov_trace_pc into every basic block.
234 ; Flag whether a prefix has been added to dump_base_name
236 bool dump_base_name_prefixed = false
238 ; Flag whether HSA generation has been explicitely disabled
240 bool flag_disable_hsa = false
252 Driver Alias(coverage)
258 Common Separate Alias(d)
261 Common Joined Alias(d)
264 Common Separate Alias(dumpbase)
267 Common Separate Alias(dumpdir)
270 Driver Separate Alias(e)
273 Driver Joined Alias(e)
276 Common Warning Alias(Wextra)
279 Driver Separate Alias(Xassembler)
282 Driver JoinedOrMissing Alias(Xassembler)
285 Driver Separate Alias(Xlinker)
288 Driver JoinedOrMissing Alias(Xlinker)
291 Driver Separate Alias(u)
294 Driver Joined Alias(u)
297 Common Driver Var(help_flag)
298 Display this information.
301 Common Driver Report Joined
302 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
305 Driver Separate Alias(x)
308 Driver Joined Alias(x)
311 Driver Separate Alias(L)
314 Driver Joined Alias(L)
316 -no-canonical-prefixes
317 Driver Alias(no-canonical-prefixes)
319 -no-standard-libraries
320 Driver Alias(nostdlib)
323 Driver Var(no_sysroot_suffix)
332 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
335 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
338 Driver Alias(pass-exit-codes)
341 Common Alias(Wpedantic)
344 Common Alias(pedantic-errors)
353 Driver Separate Alias(B)
356 Driver JoinedOrMissing Alias(B)
362 Driver Separate Alias(print-file-name=)
365 Driver JoinedOrMissing Alias(print-file-name=)
367 -print-libgcc-file-name
368 Driver Alias(print-libgcc-file-name)
370 -print-multi-directory
371 Driver Alias(print-multi-directory)
374 Driver Alias(print-multi-lib)
376 -print-multi-os-directory
377 Driver Alias(print-multi-os-directory)
380 Driver Alias(print-multiarch)
383 Driver Separate Alias(print-prog-name=)
386 Driver JoinedOrMissing Alias(print-prog-name=)
389 Driver Alias(print-search-dirs)
392 Driver Alias(print-sysroot)
394 -print-sysroot-headers-suffix
395 Driver Alias(print-sysroot-headers-suffix)
401 Driver Alias(save-temps)
407 Driver Separate Alias(specs=)
410 Driver Joined Alias(specs=)
416 Driver Alias(symbolic)
420 Alias for --help=target.
428 ;; The driver used to convert options such as --help into forms such
429 ;; as -fhelp; the following four entries are for compatibility with
430 ;; any direct uses of those (undocumented) -f forms
432 Common Driver Alias(-help)
435 Common Driver Joined Alias(-help=)
438 Common Driver Alias(-target-help)
441 Common Driver Alias(-version)
445 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
448 Common Joined Alias(-param)
451 Driver Separate Alias(-sysroot=)
454 Driver JoinedOrMissing
460 Driver Joined Separate
466 Driver Joined Separate
472 Common JoinedOrMissing Optimization
473 -O<number> Set optimization level to <number>.
477 Optimize for space rather than speed.
481 Optimize for speed disregarding exact standards compliance.
485 Optimize for debugging experience rather than speed or size.
497 Driver Joined Separate
503 Driver Joined Separate
524 Common RejectNegative Warning Alias(Wextra)
525 This switch is deprecated; use -Wextra instead.
528 Driver JoinedOrMissing
531 Driver JoinedOrMissing
534 Driver JoinedOrMissing
537 Common Var(warn_aggregate_return) Warning
538 Warn about returning structures, unions or arrays.
540 Waggressive-loop-optimizations
541 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
542 Warn if a loop with constant number of iterations triggers undefined behavior.
545 Common Var(warn_array_bounds) Warning
546 Warn if an array is accessed out of bounds.
549 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning
550 Warn if an array is accessed out of bounds.
553 Common Var(warn_attributes) Init(1) Warning
554 Warn about inappropriate attribute usage.
557 Common Var(warn_cast_align) Warning
558 Warn about pointer casts which increase alignment.
561 Common Var(warn_cpp) Init(1) Warning
562 Warn when a #warning directive is encountered.
564 Wdeprecated-declarations
565 Common Var(warn_deprecated_decl) Init(1) Warning
566 Warn about uses of __attribute__((deprecated)) declarations.
568 Wdisabled-optimization
569 Common Var(warn_disabled_optimization) Warning
570 Warn when an optimization pass is disabled.
573 Common Var(warnings_are_errors)
574 Treat all warnings as errors.
578 Treat specified warning as error.
581 Common Var(extra_warnings) Warning
582 Print extra (possibly unwanted) warnings.
585 Common Var(flag_fatal_errors)
586 Exit on the first error occurred.
589 Common RejectNegative Joined UInteger Warning
590 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes.
593 Common Var(warn_free_nonheap_object) Init(1) Warning
594 Warn when attempting to free a non-heap object.
597 Common Var(warn_hsa) Init(1) Warning
598 Warn when a function cannot be expanded to HSAIL.
600 Wimplicit-fallthrough
601 Common Alias(Wimplicit-fallthrough=,3,0) Warning
603 Wimplicit-fallthrough=
604 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning
605 Warn when a switch case falls through.
608 Common Var(warn_inline) Warning
609 Warn when an inlined function cannot be inlined.
611 Winvalid-memory-model
612 Common Var(warn_invalid_memory_model) Init(1) Warning
613 Warn when an atomic memory model parameter is known to be outside the valid range.
616 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
619 Common RejectNegative Joined UInteger Warning
620 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
623 Var(warn_nonnull_compare) Warning
624 Warn if comparing pointer parameter with nonnull attribute with NULL.
627 Common Var(warn_null_dereference) Warning
628 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
630 Wunsafe-loop-optimizations
631 Common Var(warn_unsafe_loop_optimizations) Warning
632 Warn if the loop cannot be optimized due to nontrivial assumptions.
635 Common Warning Alias(Wsuggest-attribute=noreturn)
638 Common Var(warn_odr_violations) Init(1) Warning
639 Warn about some C++ One Definition Rule violations during link time optimization.
642 Common Var(warn_overflow) Init(1) Warning
643 Warn about overflow in arithmetic expressions.
646 Common Var(warn_lto_type_mismatch) Init(1) Warning
647 During link time optimization warn about mismatched types of global declarations.
650 Common Var(warn_packed) Warning
651 Warn when the packed attribute has no effect on struct layout.
654 Common Var(warn_padded) Warning
655 Warn when padding is required to align structure members.
658 Common Var(pedantic) Init(0) Warning
659 Issue warnings needed for strict compliance to the standard.
662 Common Var(warn_return_local_addr) Init(1) Warning
663 Warn about returning a pointer/reference to a local or temporary variable.
666 Common Var(warn_shadow) Warning
667 Warn when one variable shadows another. Same as -Wshadow=global.
670 Common Warning Alias(Wshadow)
671 Warn when one variable shadows another (globally).
674 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
675 Warn when one local variable shadows another local variable or parameter.
678 Common Warning Undocumented Alias(Wshadow=local)
680 Wshadow=compatible-local
681 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
682 Warn when one local variable shadows another local variable or parameter of compatible type.
684 Wshadow-compatible-local
685 Common Warning Undocumented Alias(Wshadow=compatible-local)
688 Common Var(warn_stack_protect) Warning
689 Warn when not issuing stack smashing protection for some reason.
692 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
693 Warn if stack usage might be larger than specified amount.
697 Warn about code which might break strict aliasing rules.
700 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
701 Warn about code which might break strict aliasing rules.
705 Warn about optimizations that assume that signed overflow is undefined.
708 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
709 Warn about optimizations that assume that signed overflow is undefined.
711 Wsuggest-attribute=const
712 Common Var(warn_suggest_attribute_const) Warning
713 Warn about functions which might be candidates for __attribute__((const)).
715 Wsuggest-attribute=pure
716 Common Var(warn_suggest_attribute_pure) Warning
717 Warn about functions which might be candidates for __attribute__((pure)).
719 Wsuggest-attribute=noreturn
720 Common Var(warn_suggest_attribute_noreturn) Warning
721 Warn about functions which might be candidates for __attribute__((noreturn)).
724 Common Var(warn_suggest_final_types) Warning
725 Warn about C++ polymorphic types where adding final keyword would improve code quality.
727 Wsuggest-final-methods
728 Common Var(warn_suggest_final_methods) Warning
729 Warn about C++ virtual methods where adding final keyword would improve code quality.
732 Common Var(warn_switch_unreachable) Warning Init(1)
733 Warn about statements between switch's controlling expression and the first
737 Common Var(warn_system_headers) Warning
738 Do not suppress warnings from system headers.
741 Common Var(warn_trampolines) Warning
742 Warn whenever a trampoline is generated.
745 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
746 Warn if a comparison is always true or always false due to the limited range of the data type.
749 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
750 Warn about uninitialized automatic variables.
753 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
754 Warn about maybe uninitialized automatic variables.
757 Common Ignore Warning
758 Does nothing. Preserved for backward compatibility.
761 Common Var(warn_unused) Init(0) Warning
762 Enable all -Wunused- warnings.
764 Wunused-but-set-parameter
765 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
766 Warn when a function parameter is only set, otherwise unused.
768 Wunused-but-set-variable
769 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
770 Warn when a variable is only set, otherwise unused.
773 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
774 Warn when a function is unused.
777 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
778 Warn when a label is unused.
781 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
782 Warn when a function parameter is unused.
785 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
786 Warn when an expression value is unused.
789 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
790 Warn when a variable is unused.
793 Common Var(warn_coverage_mismatch) Init(1) Warning
794 Warn in case profiles in -fprofile-use do not match.
796 Wvector-operation-performance
797 Common Var(warn_vector_operation_performance) Warning
798 Warn when a vector operation is compiled outside the SIMD.
813 Common Separate Var(aux_info_file_name)
814 -aux-info <file> Emit declaration information into <file>.
817 Common Joined Alias(aux-info)
820 Common Separate RejectDriver Var(aux_base_name)
823 Common Separate RejectDriver
833 -d<letters> Enable dumps from specific passes of the compiler.
836 Common Separate Var(dump_base_name)
837 -dumpbase <file> Set the file basename to be used for dumps.
840 Common Separate Var(dump_dir_name)
841 -dumpdir <dir> Set the directory name to be used for dumps.
853 Driver Joined Separate
855 ; This option has historically been passed down to the linker by an
856 ; accident of a %{e*} spec, so ensure it continues to be passed down
857 ; as a single option. The supported option for this purpose is
858 ; -rdynamic. See PR 47390.
862 ; The version of the C++ ABI in use. The following values are allowed:
864 ; 0: The version of the ABI believed most conformant with the C++ ABI
865 ; specification. This ABI may change as bugs are discovered and fixed.
866 ; Therefore, 0 will not necessarily indicate the same ABI in different
869 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
871 ; 2: The version of the ABI first used in G++ 3.4, and the default
874 ; 3: The version of the ABI that fixes the missing underscore
875 ; in template non-type arguments of pointer type.
877 ; 4: The version of the ABI that introduces unambiguous mangling of
878 ; vector types. First selectable in G++ 4.5.
880 ; 5: The version of the ABI that ignores attribute const/noreturn
881 ; in function pointer mangling, and corrects mangling of decltype and
882 ; function parameters used in other parameters and the return type.
883 ; First selectable in G++ 4.6.
885 ; 6: The version of the ABI that doesn't promote scoped enums to int and
886 ; changes the mangling of template argument packs, const/static_cast,
887 ; prefix ++ and --, and a class scope function used as a template
889 ; First selectable in G++ 4.7.
891 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
892 ; corrects the mangling of lambdas in default argument scope.
893 ; First selectable in G++ 4.8.
895 ; 8: The version of the ABI that corrects the substitution behavior of
896 ; function types with function-cv-qualifiers.
897 ; First selectable in G++ 4.9 and default in G++ 5.
899 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
900 ; First selectable and default in G++ 5.2.
902 ; 10: The version of the ABI that mangles attributes that affect type
903 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
904 ; Default in G++ 6 (set in c_common_post_options).
906 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
907 ; and introduces new inheriting constructor handling.
910 ; Additional positive integers will be assigned as new versions of
911 ; the ABI become the default version of the ABI.
913 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
914 The version of the C++ ABI in use.
916 faggressive-loop-optimizations
917 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
918 Aggressively optimize loops using language constraints.
921 Common Report Var(align_functions,0) Optimization UInteger
922 Align the start of functions.
925 Common RejectNegative Joined UInteger Var(align_functions)
928 Common Report Var(align_jumps,0) Optimization UInteger
929 Align labels which are only reached by jumping.
932 Common RejectNegative Joined UInteger Var(align_jumps)
935 Common Report Var(align_labels,0) Optimization UInteger
939 Common RejectNegative Joined UInteger Var(align_labels)
942 Common Report Var(align_loops,0) Optimization UInteger
943 Align the start of loops.
946 Common RejectNegative Joined UInteger Var(align_loops)
950 Does nothing. Preserved for backward compatibility.
954 Does nothing. Preserved for backward compatibility.
956 fargument-noalias-global
958 Does nothing. Preserved for backward compatibility.
960 fargument-noalias-anything
962 Does nothing. Preserved for backward compatibility.
965 Common Driver Report Joined
966 Select what to sanitize.
969 Common Joined RejectNegative Var(common_deferred_options) Defer
970 -fasan-shadow-offset=<number> Use custom shadow memory offset.
973 Common Joined RejectNegative Var(common_deferred_options) Defer
974 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
975 in user-defined sections.
979 After diagnosing undefined behavior attempt to continue execution.
983 This switch is deprecated; use -fsanitize-recover= instead.
985 fsanitize-address-use-after-scope
986 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
988 fsanitize-undefined-trap-on-error
989 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
990 Use trap instead of a library function for undefined behavior sanitization.
992 fasynchronous-unwind-tables
993 Common Report Var(flag_asynchronous_unwind_tables) Optimization
994 Generate unwind tables that are exact at each instruction boundary.
997 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
998 Generate auto-inc/dec instructions.
1001 Common Report Var(flag_auto_profile)
1002 Use sample profile information for call graph node weights. The default
1003 profile file is fbdata.afdo in 'pwd'.
1006 Common Joined RejectNegative Var(auto_profile_file)
1007 Use sample profile information for call graph node weights. The profile
1008 file is specified in the argument.
1010 ; -fcheck-bounds causes gcc to generate array bounds checks.
1011 ; For C, C++ and ObjC: defaults off.
1012 ; For Java: defaults to on.
1013 ; For Fortran: defaults to off.
1015 Common Report Var(flag_bounds_check)
1016 Generate code to check bounds before indexing arrays.
1019 Common Report Var(flag_branch_on_count_reg) Optimization
1020 Replace add, compare, branch with branch on count register.
1022 fbranch-probabilities
1023 Common Report Var(flag_branch_probabilities) Optimization
1024 Use profiling information for branch probabilities.
1026 fbranch-target-load-optimize
1027 Common Report Var(flag_branch_target_load_optimize) Optimization
1028 Perform branch target load optimization before prologue / epilogue threading.
1030 fbranch-target-load-optimize2
1031 Common Report Var(flag_branch_target_load_optimize2) Optimization
1032 Perform branch target load optimization after prologue / epilogue threading.
1035 Common Report Var(flag_btr_bb_exclusive) Optimization
1036 Restrict target load migration not to re-use registers in any basic block.
1039 Common Joined RejectNegative Var(common_deferred_options) Defer
1040 -fcall-saved-<register> Mark <register> as being preserved across functions.
1043 Common Joined RejectNegative Var(common_deferred_options) Defer
1044 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1046 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1047 ; be saved across function calls, if that produces overall better code.
1048 ; Optional now, so people can test it.
1050 Common Report Var(flag_caller_saves) Optimization
1051 Save registers around function calls.
1054 Common Report Var(flag_check_data_deps)
1055 This switch is deprecated; do not use.
1058 Common Var(flag_check_new)
1059 Check the return value of new in C++.
1062 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1063 Perform internal consistency checkings.
1066 Common Joined RejectNegative UInteger Var(flag_checking)
1067 Perform internal consistency checkings.
1070 Common Report Var(flag_code_hoisting) Optimization
1071 Enable code hoisting.
1073 fcombine-stack-adjustments
1074 Common Report Var(flag_combine_stack_adjustments) Optimization
1075 Looks for opportunities to reduce stack adjustments and stack references.
1078 Common Report Var(flag_no_common,0)
1079 Do not put uninitialized globals in the common section.
1083 ; Converted by the driver to -fcompare-debug= options.
1086 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1087 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1089 fcompare-debug-second
1090 Common Driver RejectNegative Var(flag_compare_debug)
1091 Run only the second compilation of -fcompare-debug.
1094 Common Report Var(flag_compare_elim_after_reload) Optimization
1095 Perform comparison elimination after register allocation has finished.
1098 Common Var(flag_conserve_stack) Optimization
1099 Do not perform optimizations increasing noticeably stack usage.
1102 Common Report Var(flag_cprop_registers) Optimization
1103 Perform a register copy-propagation optimization pass.
1106 Common Report Var(flag_crossjumping) Optimization
1107 Perform cross-jumping optimization.
1110 Common Report Var(flag_cse_follow_jumps) Optimization
1111 When running CSE, follow jumps to their targets.
1115 Does nothing. Preserved for backward compatibility.
1118 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1119 Omit range reduction step when performing complex division.
1122 Common Report Var(flag_cx_fortran_rules) Optimization
1123 Complex multiplication and division follow Fortran rules.
1126 Common Report Var(flag_data_sections)
1127 Place data items into their own section.
1130 Common Report Var(common_deferred_options) Defer
1131 List all available debugging counters with their limits and counts.
1134 Common RejectNegative Joined Var(common_deferred_options) Defer
1135 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1138 Common Joined RejectNegative Var(common_deferred_options) Defer
1139 Map one directory name to another in debug information.
1141 fdebug-types-section
1142 Common Report Var(flag_debug_types_section) Init(0)
1143 Output .debug_types section when using DWARF v4 debuginfo.
1145 ; Nonzero for -fdefer-pop: don't pop args after each function call
1146 ; instead save them up to pop many calls' args with one insns.
1148 Common Report Var(flag_defer_pop) Optimization
1149 Defer popping functions args from stack until later.
1152 Common Report Var(flag_delayed_branch) Optimization
1153 Attempt to fill delay slots of branch instructions.
1155 fdelete-dead-exceptions
1156 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1157 Delete dead instructions that may throw exceptions.
1159 fdelete-null-pointer-checks
1160 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1161 Delete useless null pointer checks.
1163 fdevirtualize-at-ltrans
1164 Common Report Var(flag_ltrans_devirtualize)
1165 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1167 fdevirtualize-speculatively
1168 Common Report Var(flag_devirtualize_speculatively) Optimization
1169 Perform speculative devirtualization.
1172 Common Report Var(flag_devirtualize) Optimization
1173 Try to convert virtual calls to direct ones.
1175 fdiagnostics-show-location=
1176 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1177 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1179 ; Required for these enum values.
1184 Name(diagnostic_prefixing_rule) Type(int)
1187 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1190 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1192 fdiagnostics-show-caret
1193 Common Var(flag_diagnostics_show_caret) Init(1)
1194 Show the source line with a caret indicating the column.
1197 Common Alias(fdiagnostics-color=,always,never)
1201 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1202 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1204 ; Required for these enum values.
1209 Name(diagnostic_color_rule) Type(int)
1212 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1215 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1218 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1220 fdiagnostics-parseable-fixits
1221 Common Var(flag_diagnostics_parseable_fixits)
1222 Print fixit hints in machine-readable form.
1224 fdiagnostics-generate-patch
1225 Common Var(flag_diagnostics_generate_patch)
1226 Print fix-it hints to stderr in unified diff format.
1228 fdiagnostics-show-option
1229 Common Var(flag_diagnostics_show_option) Init(1)
1230 Amend appropriate diagnostic messages with the command line option that controls them.
1233 Common Joined RejectNegative Var(common_deferred_options) Defer
1234 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1237 Common Joined RejectNegative Var(common_deferred_options) Defer
1238 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1241 Common Joined RejectNegative Var(common_deferred_options) Defer
1242 -fdump-<type> Dump various compiler internals to a file.
1245 Driver RejectNegative
1248 Common RejectNegative Joined Var(flag_dump_final_insns)
1249 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1252 Common RejectNegative Joined Var(flag_dump_go_spec)
1253 -fdump-go-spec=filename Write all declarations to file as Go code.
1256 Common Report Var(flag_dump_noaddr)
1257 Suppress output of addresses in debugging dumps.
1260 Common Driver Var(flag_report_bug)
1261 Collect and dump debug information into temporary file if ICE in C/C++
1264 fdump-internal-locations
1265 Common Var(flag_dump_locations) Init(0)
1266 Dump detailed information on GCC's internal representation of source code locations.
1269 Common Var(flag_dump_passes) Init(0)
1270 Dump optimization passes.
1273 Common Report Var(flag_dump_unnumbered)
1274 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1276 fdump-unnumbered-links
1277 Common Report Var(flag_dump_unnumbered_links)
1278 Suppress output of previous and next insn numbers in debugging dumps.
1281 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1282 Enable CFI tables via GAS assembler directives.
1285 Common Report Var(flag_early_inlining) Init(1) Optimization
1286 Perform early inlining.
1288 feliminate-dwarf2-dups
1289 Common Report Var(flag_eliminate_dwarf2_dups)
1290 Perform DWARF duplicate elimination.
1293 Common Report Var(flag_ipa_sra) Init(0) Optimization
1294 Perform interprocedural reduction of aggregates.
1296 feliminate-unused-debug-symbols
1297 Common Report Var(flag_debug_only_used_symbols)
1298 Perform unused symbol elimination in debug info.
1300 feliminate-unused-debug-types
1301 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1302 Perform unused type elimination in debug info.
1304 femit-class-debug-always
1305 Common Report Var(flag_emit_class_debug_always) Init(0)
1306 Do not suppress C++ class debug information.
1309 Common Report Var(flag_exceptions) Optimization
1310 Enable exception handling.
1312 fexpensive-optimizations
1313 Common Report Var(flag_expensive_optimizations) Optimization
1314 Perform a number of minor, expensive optimizations.
1317 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1318 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1321 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1324 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1327 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1333 Common Var(flag_fat_lto_objects)
1334 Output lto objects containing both the intermediate language and binary output.
1337 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1338 Assume no NaNs or infinities are generated.
1341 Common Joined RejectNegative Var(common_deferred_options) Defer
1342 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1345 Common Report Var(flag_float_store) Optimization
1346 Don't allocate floats and doubles in extended-precision registers.
1350 Does nothing. Preserved for backward compatibility.
1353 Common Report Var(flag_forward_propagate) Optimization
1354 Perform a forward propagation pass on RTL.
1357 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1358 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1361 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1364 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1366 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1368 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1371 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1373 ffp-int-builtin-inexact
1374 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1375 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1377 ; Nonzero means don't put addresses of constant functions in registers.
1378 ; Used for compiling the Unix kernel, where strange substitutions are
1379 ; done on the assembly output.
1381 Common Report Var(flag_no_function_cse,0) Optimization
1382 Allow function addresses to be held in registers.
1385 Common Report Var(flag_function_sections)
1386 Place each function into its own section.
1389 Common Report Var(flag_gcse) Optimization
1390 Perform global common subexpression elimination.
1393 Common Report Var(flag_gcse_lm) Init(1) Optimization
1394 Perform enhanced load motion during global common subexpression elimination.
1397 Common Report Var(flag_gcse_sm) Init(0) Optimization
1398 Perform store motion after global common subexpression elimination.
1401 Common Report Var(flag_gcse_las) Init(0) Optimization
1402 Perform redundant load after store elimination in global common subexpression
1406 Common Report Var(flag_gcse_after_reload) Optimization
1407 Perform global common subexpression elimination after register allocation has
1411 Name(dwarf_gnat_encodings) Type(int)
1414 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1417 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1420 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1423 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1424 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1426 ; This option is not documented yet as its semantics will change.
1428 Common Report Var(flag_graphite) Optimization
1429 Enable in and out of Graphite representation.
1432 Common Report Var(flag_graphite_identity) Optimization
1433 Enable Graphite Identity transformation.
1435 fhoist-adjacent-loads
1436 Common Report Var(flag_hoist_adjacent_loads) Optimization
1437 Enable hoisting adjacent loads to encourage generating conditional move
1441 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1442 ; Always keep a pointer to a live memory block
1444 floop-parallelize-all
1445 Common Report Var(flag_loop_parallelize_all) Optimization
1446 Mark all loops as parallel.
1449 Common Alias(floop-nest-optimize)
1450 Enable loop nest transforms. Same as -floop-nest-optimize.
1453 Common Alias(floop-nest-optimize)
1454 Enable loop nest transforms. Same as -floop-nest-optimize.
1457 Common Alias(floop-nest-optimize)
1458 Enable loop nest transforms. Same as -floop-nest-optimize.
1460 floop-unroll-and-jam
1461 Common Alias(floop-nest-optimize)
1462 Enable loop nest transforms. Same as -floop-nest-optimize.
1465 Common Report Var(flag_tm)
1466 Enable support for GNU transactional memory.
1469 Common Report Var(flag_gnu_unique) Init(1)
1470 Use STB_GNU_UNIQUE if supported by the assembler.
1474 Does nothing. Preserved for backward compatibility.
1477 Common Report Var(flag_loop_nest_optimize) Optimization
1478 Enable the loop nest optimizer.
1480 fstrict-volatile-bitfields
1481 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1482 Force bitfield accesses to match their type width.
1485 Common Report Var(flag_store_merging) Optimization
1486 Merge adjacent stores.
1488 fguess-branch-probability
1489 Common Report Var(flag_guess_branch_prob) Optimization
1490 Enable guessing of branch probabilities.
1492 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1493 ; Generate position-independent code for executables if possible
1494 ; On SVR4 targets, it also controls whether or not to emit a
1495 ; string identifying the compiler.
1497 Common Report Var(flag_no_ident,0)
1498 Process #ident directives.
1501 Common Report Var(flag_if_conversion) Optimization
1502 Perform conversion of conditional jumps to branchless equivalents.
1505 Common Report Var(flag_if_conversion2) Optimization
1506 Perform conversion of conditional jumps to conditional execution.
1509 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1510 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1513 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1516 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1519 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1522 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1524 ftree-loop-if-convert
1525 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1526 Convert conditional jumps in innermost loops to branchless equivalents.
1528 ftree-loop-if-convert-stores
1529 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1530 Also if-convert conditional jumps containing memory writes.
1532 ; -finhibit-size-directive inhibits output of .size for ELF.
1533 ; This is used only for compiling crtstuff.c,
1534 ; and it may be extended to other effects
1535 ; needed for crtstuff.c on other systems.
1536 finhibit-size-directive
1537 Common Report Var(flag_inhibit_size_directive)
1538 Do not generate .size directives.
1541 Common Report Var(flag_indirect_inlining) Optimization
1542 Perform indirect inlining.
1544 ; General flag to enable inlining. Specifying -fno-inline will disable
1545 ; all inlining apart from always-inline functions.
1547 Common Report Var(flag_no_inline,0) Init(0) Optimization
1548 Enable inlining of function declared \"inline\", disabling disables all inlining.
1550 finline-small-functions
1551 Common Report Var(flag_inline_small_functions) Optimization
1552 Integrate functions into their callers when code size is known not to grow.
1555 Common Report Var(flag_inline_functions) Optimization
1556 Integrate functions not declared \"inline\" into their callers when profitable.
1558 finline-functions-called-once
1559 Common Report Var(flag_inline_functions_called_once) Optimization
1560 Integrate functions only required by their single caller.
1563 Common RejectNegative Joined Alias(finline-limit=)
1566 Common RejectNegative Joined UInteger
1567 -finline-limit=<number> Limit the size of inlined functions to <number>.
1570 Common Report Var(flag_inline_atomics) Init(1) Optimization
1571 Inline __atomic operations when a lock free instruction sequence is available.
1573 finstrument-functions
1574 Common Report Var(flag_instrument_function_entry_exit)
1575 Instrument function entry and exit with profiling calls.
1577 finstrument-functions-exclude-function-list=
1578 Common RejectNegative Joined
1579 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1581 finstrument-functions-exclude-file-list=
1582 Common RejectNegative Joined
1583 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1586 Common Report Var(flag_ipa_cp) Optimization
1587 Perform interprocedural constant propagation.
1590 Common Report Var(flag_ipa_cp_clone) Optimization
1591 Perform cloning to make Interprocedural constant propagation stronger.
1594 Common Report Var(flag_ipa_cp_alignment) Optimization
1595 Perform alignment discovery and propagation to make Interprocedural constant propagation stronger.
1598 Common Report Var(flag_ipa_bit_cp) Optimization
1599 Perform interprocedural bitwise constant propagation.
1602 Common Report Var(flag_ipa_profile) Init(0) Optimization
1603 Perform interprocedural profile propagation.
1606 Common Report Var(flag_ipa_pta) Init(0) Optimization
1607 Perform interprocedural points-to analysis.
1610 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1611 Discover pure and const functions.
1614 Common Report Var(flag_ipa_icf) Optimization
1615 Perform Identical Code Folding for functions and read-only variables.
1618 Common Report Var(flag_ipa_icf_functions) Optimization
1619 Perform Identical Code Folding for functions.
1622 Common Report Var(flag_ipa_icf_variables) Optimization
1623 Perform Identical Code Folding for variables.
1626 Common Report Var(flag_ipa_reference) Init(0) Optimization
1627 Discover readonly and non addressable static variables.
1631 Does nothing. Preserved for backward compatibility.
1635 Does nothing. Preserved for backward compatibility.
1638 Common Report Var(flag_ipa_vrp) Optimization
1639 Perform IPA Value Range Propagation.
1642 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1643 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1646 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1649 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1652 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1655 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1656 -fira-region=[one|all|mixed] Set regions for IRA.
1659 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1662 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1665 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1668 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1671 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1672 Use IRA based register pressure calculation
1673 in RTL hoist optimizations.
1676 Common Report Var(flag_ira_loop_pressure) Optimization
1677 Use IRA based register pressure calculation
1678 in RTL loop optimizations.
1680 fira-share-save-slots
1681 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1682 Share slots for saving different hard registers.
1684 fira-share-spill-slots
1685 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1686 Share stack slots for spilled pseudo-registers.
1689 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1690 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1693 Common Report Var(flag_ivopts) Init(1) Optimization
1694 Optimize induction variables on trees.
1697 Common Var(flag_jump_tables) Init(1) Optimization
1698 Use jump tables for sufficiently large switch statements.
1700 fkeep-inline-functions
1701 Common Report Var(flag_keep_inline_functions)
1702 Generate code for functions even if they are fully inlined.
1704 fkeep-static-functions
1705 Common Report Var(flag_keep_static_functions)
1706 Generate code for static functions even if they are never called.
1709 Common Report Var(flag_keep_static_consts) Init(1)
1710 Emit static const variables even if they are not used.
1713 Common Report Var(flag_leading_underscore) Init(-1)
1714 Give external symbols a leading underscore.
1718 Does nothing. Preserved for backward compatibility.
1721 Common Report Var(flag_lra_remat) Optimization
1722 Do CFG-sensitive rematerialization in LRA.
1726 Enable link-time optimization.
1729 Common RejectNegative Joined Var(flag_lto)
1730 Link-time optimization with number of parallel jobs or jobserver.
1733 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1736 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1739 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1742 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1745 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1748 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1751 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1752 Specify the algorithm to partition symbols and vars at linktime.
1754 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1755 flto-compression-level=
1756 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1757 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1759 flto-odr-type-merging
1760 Common Report Var(flag_lto_odr_type_mering) Init(1)
1761 Merge C++ types using One Definition Rule.
1764 Common Report Var(flag_lto_report) Init(0)
1765 Report various link-time optimization statistics.
1768 Common Report Var(flag_lto_report_wpa) Init(0)
1769 Report various link-time optimization statistics for WPA only.
1772 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1773 Set errno after built-in math functions.
1776 Common Joined RejectNegative UInteger Var(flag_max_errors)
1777 -fmax-errors=<number> Maximum number of errors to report.
1780 Common Report Var(mem_report)
1781 Report on permanent memory allocation.
1784 Common Report Var(mem_report_wpa)
1785 Report on permanent memory allocation in WPA only.
1787 ; This will attempt to merge constant section constants, if 1 only
1788 ; string constants and constants from constant pool, if 2 also constant
1790 fmerge-all-constants
1791 Common Report Var(flag_merge_constants,2) Init(1)
1792 Attempt to merge identical constants and constant variables.
1795 Common Report Var(flag_merge_constants,1)
1796 Attempt to merge identical constants across compilation units.
1798 fmerge-debug-strings
1799 Common Report Var(flag_merge_debug_strings) Init(1)
1800 Attempt to merge identical debug strings across compilation units.
1803 Common RejectNegative Joined UInteger
1804 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1807 Common Report Var(flag_modulo_sched) Optimization
1808 Perform SMS based modulo scheduling before the first scheduling pass.
1810 fmodulo-sched-allow-regmoves
1811 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1812 Perform SMS based modulo scheduling with register moves allowed.
1814 fmove-loop-invariants
1815 Common Report Var(flag_move_loop_invariants) Optimization
1816 Move loop invariant computations out of loops.
1819 Common Var(flag_dce) Init(1) Optimization
1820 Use the RTL dead code elimination pass.
1823 Common Var(flag_dse) Init(1) Optimization
1824 Use the RTL dead store elimination pass.
1826 freschedule-modulo-scheduled-loops
1827 Common Report Var(flag_resched_modulo_sched) Optimization
1828 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1830 fnon-call-exceptions
1831 Common Report Var(flag_non_call_exceptions) Optimization
1832 Support synchronous non-call exceptions.
1835 Common Driver Joined MissingArgError(options or targets missing after %qs)
1836 -foffload=<targets>=<options> Specify offloading targets and options for them.
1839 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1840 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1843 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1846 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1849 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1852 Common Report Var(flag_omit_frame_pointer) Optimization
1853 When possible do not generate stack frames.
1856 Common Report Var(flag_opt_info) Optimization
1857 Enable all optimization info dumps on stderr.
1860 Common Joined RejectNegative Var(common_deferred_options) Defer
1861 -fopt-info[-<type>=filename] Dump compiler optimization details.
1863 foptimize-register-move
1865 Does nothing. Preserved for backward compatibility.
1867 foptimize-sibling-calls
1868 Common Report Var(flag_optimize_sibling_calls) Optimization
1869 Optimize sibling and tail recursive calls.
1872 Common Report Var(flag_partial_inlining) Optimization
1873 Perform partial inlining.
1876 Common Report Var(pre_ipa_mem_report)
1877 Report on memory allocation before interprocedural optimization.
1879 fpost-ipa-mem-report
1880 Common Report Var(post_ipa_mem_report)
1881 Report on memory allocation before interprocedural optimization.
1884 Common Report Var(flag_pack_struct) Optimization
1885 Pack structure members together without holes.
1888 Common RejectNegative Joined UInteger Optimization
1889 -fpack-struct=<number> Set initial maximum structure member alignment.
1892 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1893 Return small aggregates in memory, not registers.
1896 Common Report Var(flag_peel_loops) Optimization
1897 Perform loop peeling.
1900 Common Report Var(flag_no_peephole,0) Optimization
1901 Enable machine specific peephole optimizations.
1904 Common Report Var(flag_peephole2) Optimization
1905 Enable an RTL peephole pass before sched2.
1908 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1909 Generate position-independent code if possible (large mode).
1912 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1913 Generate position-independent code for executables if possible (large mode).
1916 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1917 Generate position-independent code if possible (small mode).
1920 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1921 Generate position-independent code for executables if possible (small mode).
1924 Common Report Var(flag_plt) Init(1) Optimization
1925 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
1928 Common Joined RejectNegative Var(common_deferred_options) Defer
1929 Specify a plugin to load.
1932 Common Joined RejectNegative Var(common_deferred_options) Defer
1933 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
1935 fpredictive-commoning
1936 Common Report Var(flag_predictive_commoning) Optimization
1937 Run predictive commoning optimization.
1939 fprefetch-loop-arrays
1940 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1941 Generate prefetch instructions, if available, for arrays in loops.
1944 Common Report Var(profile_flag)
1945 Enable basic program profiling code.
1948 Common Report Var(profile_arc_flag)
1949 Insert arc-based program profiling code.
1952 Common Joined RejectNegative Var(profile_data_prefix)
1953 Set the top-level directory for storing the profile data.
1954 The default is 'pwd'.
1957 Common Report Var(flag_profile_correction)
1958 Enable correction of flow inconsistent profile data input.
1961 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
1962 -fprofile-update=[single|atomic] Set the profile update method.
1965 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
1968 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
1971 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
1975 Enable common options for generating profile info for profile feedback directed optimizations.
1978 Common Joined RejectNegative
1979 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
1982 Common Var(flag_profile_use)
1983 Enable common options for performing profile feedback directed optimizations.
1986 Common Joined RejectNegative
1987 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
1990 Common Report Var(flag_profile_values)
1991 Insert code to profile values of expressions.
1994 Common Report Var(profile_report)
1995 Report on consistency of profile.
1997 fprofile-reorder-functions
1998 Common Report Var(flag_profile_reorder_functions)
1999 Enable function reordering that improves code placement.
2002 Common Var(common_deferred_options) Defer
2005 Common Joined RejectNegative Var(common_deferred_options) Defer
2006 -frandom-seed=<string> Make compile reproducible using <string>.
2008 ; This switch causes the command line that was used to create an
2009 ; object file to be recorded into the object file. The exact format
2010 ; of this recording is target and binary file format dependent.
2011 ; It is related to the -fverbose-asm switch, but that switch only
2012 ; records information in the assembler output file as comments, so
2013 ; they never reach the object file.
2014 frecord-gcc-switches
2015 Common Report Var(flag_record_gcc_switches)
2016 Record gcc command line switches in the object file.
2019 Common Report Var(flag_pcc_struct_return,0) Optimization
2020 Return small aggregates in registers.
2024 Does nothing. Preserved for backward compatibility.
2027 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2028 Tell DSE that the storage for a C++ object is dead when the constructor
2029 starts and when the destructor finishes.
2032 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization
2034 flive-range-shrinkage
2035 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2036 Relief of register pressure through live range shrinkage.
2039 Common Report Var(flag_rename_registers) Init(2) Optimization
2040 Perform a register renaming optimization pass.
2043 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2044 Perform a target dependent instruction fusion optimization pass.
2047 Common Report Var(flag_reorder_blocks) Optimization
2048 Reorder basic blocks to improve code placement.
2050 freorder-blocks-algorithm=
2051 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2052 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2055 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2058 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2061 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2063 freorder-blocks-and-partition
2064 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2065 Reorder basic blocks and partition into hot and cold sections.
2068 Common Report Var(flag_reorder_functions) Optimization
2069 Reorder functions to improve code placement.
2071 frerun-cse-after-loop
2072 Common Report Var(flag_rerun_cse_after_loop) Optimization
2073 Add a common subexpression elimination pass after loop optimizations.
2077 Does nothing. Preserved for backward compatibility.
2080 Common Report Var(flag_rounding_math) Optimization SetByCombined
2081 Disable optimizations that assume default FP rounding behavior.
2084 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2085 Enable scheduling across basic blocks.
2088 Common Report Var(flag_sched_pressure) Init(0) Optimization
2089 Enable register pressure sensitive insn scheduling.
2092 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2093 Allow speculative motion of non-loads.
2096 Common Report Var(flag_schedule_speculative_load) Optimization
2097 Allow speculative motion of some loads.
2099 fsched-spec-load-dangerous
2100 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2101 Allow speculative motion of more loads.
2104 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2105 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2107 fsched2-use-superblocks
2108 Common Report Var(flag_sched2_use_superblocks) Optimization
2109 If scheduling post reload, do superblock scheduling.
2113 Does nothing. Preserved for backward compatibility.
2116 Common Report Var(flag_schedule_insns) Optimization
2117 Reschedule instructions before register allocation.
2120 Common Report Var(flag_schedule_insns_after_reload) Optimization
2121 Reschedule instructions after register allocation.
2123 ; This flag should be on when a target implements non-trivial
2124 ; scheduling hooks, maybe saving some information for its own sake.
2125 ; On IA64, for example, this is used for correct bundling.
2126 fselective-scheduling
2127 Common Report Var(flag_selective_scheduling) Optimization
2128 Schedule instructions using selective scheduling algorithm.
2130 fselective-scheduling2
2131 Common Report Var(flag_selective_scheduling2) Optimization
2132 Run selective scheduling after reload.
2135 Common Undocumented Var(flag_self_test)
2138 fsel-sched-pipelining
2139 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2140 Perform software pipelining of inner loops during selective scheduling.
2142 fsel-sched-pipelining-outer-loops
2143 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2144 Perform software pipelining of outer loops during selective scheduling.
2146 fsel-sched-reschedule-pipelined
2147 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2148 Reschedule pipelined regions without pipelining.
2150 fsemantic-interposition
2151 Common Report Var(flag_semantic_interposition) Init(1)
2152 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2154 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2155 ; of stalled insns into the ready list.
2156 fsched-stalled-insns
2157 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2158 Allow premature scheduling of queued insns.
2160 fsched-stalled-insns=
2161 Common RejectNegative Joined UInteger Optimization
2162 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2164 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2165 ; be examined for a dependency on a stalled insn that is candidate for
2166 ; premature removal from the queue of stalled insns into the ready list (has
2167 ; an effect only if the flag 'sched_stalled_insns' is set).
2168 fsched-stalled-insns-dep
2169 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2170 Set dependence distance checking in premature scheduling of queued insns.
2172 fsched-stalled-insns-dep=
2173 Common RejectNegative Joined UInteger Optimization
2174 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2176 fsched-group-heuristic
2177 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2178 Enable the group heuristic in the scheduler.
2180 fsched-critical-path-heuristic
2181 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2182 Enable the critical path heuristic in the scheduler.
2184 fsched-spec-insn-heuristic
2185 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2186 Enable the speculative instruction heuristic in the scheduler.
2188 fsched-rank-heuristic
2189 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2190 Enable the rank heuristic in the scheduler.
2192 fsched-last-insn-heuristic
2193 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2194 Enable the last instruction heuristic in the scheduler.
2196 fsched-dep-count-heuristic
2197 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2198 Enable the dependent count heuristic in the scheduler.
2201 Common Report Var(flag_section_anchors) Optimization
2202 Access data in the same section from shared anchor points.
2206 Does nothing. Preserved for backward compatibility.
2210 Does nothing. Preserved for backward compatibility.
2213 Common Report Var(flag_ree) Init(0)
2214 Turn on Redundant Extensions Elimination pass.
2217 Common Report Var(flag_show_column) Init(1)
2218 Show column numbers in diagnostics, when available. Default on.
2221 Common Report Var(flag_shrink_wrap) Optimization
2222 Emit function prologues only before parts of the function that need it,
2223 rather than at the top of the function.
2225 fshrink-wrap-separate
2226 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2227 Shrink-wrap parts of the prologue and epilogue separately.
2230 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2231 Disable optimizations observable by IEEE signaling NaNs.
2234 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2235 Disable floating point optimizations that ignore the IEEE signedness of zero.
2237 fsingle-precision-constant
2238 Common Report Var(flag_single_precision_constant) Optimization
2239 Convert floating point constants to single precision constants.
2241 fsplit-ivs-in-unroller
2242 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2243 Split lifetimes of induction variables when loops are unrolled.
2246 Common Report Var(flag_split_stack) Init(-1)
2247 Generate discontiguous stack frames.
2250 Common Report Var(flag_split_wide_types) Optimization
2251 Split wide types into independent registers.
2254 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2255 Enable backward propagation of use properties at the SSA level.
2258 Common Report Var(flag_ssa_phiopt) Optimization
2259 Optimize conditional patterns using SSA PHI nodes.
2262 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2263 Optimize amount of stdarg registers saved to stack at start of function.
2265 fvariable-expansion-in-unroller
2266 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2267 Apply variable expansion when loops are unrolled.
2270 Common Report RejectNegative Joined
2271 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2274 Common Alias(fstack-check=, specific, no)
2275 Insert stack checking code into the program. Same as -fstack-check=specific.
2278 Common Var(common_deferred_options) Defer
2280 fstack-limit-register=
2281 Common RejectNegative Joined Var(common_deferred_options) Defer
2282 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2284 fstack-limit-symbol=
2285 Common RejectNegative Joined Var(common_deferred_options) Defer
2286 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2289 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2290 Use propolice as a stack protection method.
2292 fstack-protector-all
2293 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2294 Use a stack protection method for every function.
2296 fstack-protector-strong
2297 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2298 Use a smart stack protection method for certain functions.
2300 fstack-protector-explicit
2301 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2302 Use stack protection method only for functions with the stack_protect attribute.
2305 Common RejectNegative Var(flag_stack_usage)
2306 Output stack usage information on a per-function basis.
2310 Does nothing. Preserved for backward compatibility.
2312 ; Nonzero if we should do (language-dependent) alias analysis.
2313 ; Typically, this analysis will assume that expressions of certain
2314 ; types do not alias expressions of certain other types. Only used
2315 ; if alias analysis (in general) is enabled.
2317 Common Report Var(flag_strict_aliasing) Optimization
2318 Assume strict aliasing rules apply.
2321 Common Report Var(flag_strict_overflow) Optimization
2322 Treat signed overflow as undefined.
2325 Common Report Var(flag_sync_libcalls) Init(1)
2326 Implement __atomic operations via libcalls to legacy __sync functions.
2329 Common Report Var(flag_syntax_only)
2330 Check for syntax errors, then stop.
2333 Common Report Var(flag_test_coverage)
2334 Create data files needed by \"gcov\".
2337 Common Report Var(flag_thread_jumps) Optimization
2338 Perform jump threading optimizations.
2341 Common Report Var(time_report)
2342 Report the time taken by each compiler pass.
2344 ftime-report-details
2345 Common Report Var(time_report_details)
2346 Record times taken by sub-phases separately.
2349 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2350 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2353 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2356 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2359 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2362 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2365 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2368 Common Report Var(flag_toplevel_reorder) Init(2)
2369 Reorder top level functions, variables, and asms.
2372 Common Report Var(flag_tracer) Optimization
2373 Perform superblock formation via tail duplication.
2376 Common Report Var(flag_trampolines) Init(0)
2377 For targets that normally need trampolines for nested functions, always
2378 generate them instead of using descriptors.
2380 ; Zero means that floating-point math operations cannot generate a
2381 ; (user-visible) trap. This is the case, for example, in nonstop
2382 ; IEEE 754 arithmetic.
2384 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2385 Assume floating-point operations can trap.
2388 Common Report Var(flag_trapv) Optimization
2389 Trap for signed overflow in addition, subtraction and multiplication.
2392 Common Report Var(flag_tree_ccp) Optimization
2393 Enable SSA-CCP optimization on trees.
2396 Common Report Var(flag_tree_bit_ccp) Optimization
2397 Enable SSA-BIT-CCP optimization on trees.
2401 Does nothing. Preserved for backward compatibility.
2404 Common Report Var(flag_tree_ch) Optimization
2405 Enable loop header copying on trees.
2407 ftree-coalesce-inlined-vars
2408 Common Ignore RejectNegative
2409 Does nothing. Preserved for backward compatibility.
2412 Common Report Var(flag_tree_coalesce_vars) Optimization
2413 Enable SSA coalescing of user variables.
2417 Does nothing. Preserved for backward compatibility.
2420 Common Report Var(flag_tree_copy_prop) Optimization
2421 Enable copy propagation on trees.
2423 ftree-store-copy-prop
2425 Does nothing. Preserved for backward compatibility.
2428 Common Report Var(flag_tree_cselim) Init(2) Optimization
2429 Transform condition stores into unconditional ones.
2431 ftree-switch-conversion
2432 Common Report Var(flag_tree_switch_conversion) Optimization
2433 Perform conversions of switch initializations.
2436 Common Report Var(flag_tree_dce) Optimization
2437 Enable SSA dead code elimination optimization on trees.
2439 ftree-dominator-opts
2440 Common Report Var(flag_tree_dom) Optimization
2441 Enable dominator optimizations.
2444 Common Report Var(flag_tree_tail_merge) Optimization
2445 Enable tail merging on trees.
2448 Common Report Var(flag_tree_dse) Optimization
2449 Enable dead store elimination.
2452 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2453 Enable forward propagation on trees.
2456 Common Report Var(flag_tree_fre) Optimization
2457 Enable Full Redundancy Elimination (FRE) on trees.
2460 Common Report Var(flag_optimize_strlen) Optimization
2461 Enable string length optimizations on trees.
2463 fisolate-erroneous-paths-dereference
2464 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2465 Detect paths that trigger erroneous or undefined behavior due to
2466 dereferencing a null pointer. Isolate those paths from the main control
2467 flow and turn the statement with erroneous or undefined behavior into a trap.
2469 fisolate-erroneous-paths-attribute
2470 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2471 Detect paths that trigger erroneous or undefined behavior due a null value
2472 being used in a way forbidden by a returns_nonnull or nonnull
2473 attribute. Isolate those paths from the main control flow and turn the
2474 statement with erroneous or undefined behavior into a trap.
2476 ftree-loop-distribution
2477 Common Report Var(flag_tree_loop_distribution) Optimization
2478 Enable loop distribution on trees.
2480 ftree-loop-distribute-patterns
2481 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2482 Enable loop distribution for patterns transformed into a library call.
2485 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2486 Enable loop invariant motion on trees.
2489 Common Alias(floop-nest-optimize)
2490 Enable loop nest transforms. Same as -floop-nest-optimize.
2493 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2494 Create canonical induction variables in loops.
2497 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2498 Enable loop optimizations on tree level.
2500 ftree-parallelize-loops=
2501 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2502 Enable automatic parallelization of loops.
2505 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2506 Enable hoisting loads from conditional pointers.
2509 Common Report Var(flag_tree_pre) Optimization
2510 Enable SSA-PRE optimization on trees.
2513 Common Report Var(flag_tree_partial_pre) Optimization
2514 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2517 Common Report Var(flag_tree_pta) Optimization
2518 Perform function-local points-to analysis on trees.
2521 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2522 Enable reassociation on tree level.
2526 Does nothing. Preserved for backward compatibility.
2529 Common Report Var(flag_tree_sink) Optimization
2530 Enable SSA code sinking on trees.
2533 Common Report Var(flag_tree_slsr) Optimization
2534 Perform straight-line strength reduction.
2537 Common Report Var(flag_tree_sra) Optimization
2538 Perform scalar replacement of aggregates.
2541 Common Report Var(flag_tree_ter) Optimization
2542 Replace temporary expressions in the SSA->normal pass.
2545 Common Report Var(flag_tree_live_range_split) Optimization
2546 Perform live range splitting during the SSA->normal pass.
2549 Common Report Var(flag_tree_vrp) Init(0) Optimization
2550 Perform Value Range Propagation on trees.
2553 Common Report Var(flag_split_paths) Init(0) Optimization
2554 Split paths leading to loop backedges.
2556 funconstrained-commons
2557 Common Var(flag_unconstrained_commons) Optimization
2558 Assume common declarations may be overridden with ones with a larger
2562 Common Report Var(flag_unit_at_a_time) Init(1)
2563 Compile whole compilation unit at a time.
2566 Common Report Var(flag_unroll_loops) Optimization
2567 Perform loop unrolling when iteration count is known.
2570 Common Report Var(flag_unroll_all_loops) Optimization
2571 Perform loop unrolling for all loops.
2573 ; Nonzero means that loop optimizer may assume that the induction variables
2574 ; that control loops do not overflow and that the loops with nontrivial
2575 ; exit condition are not infinite
2576 funsafe-loop-optimizations
2578 Does nothing. Preserved for backward compatibility.
2581 Common Report Var(flag_associative_math) SetByCombined Optimization
2582 Allow optimization for floating-point arithmetic which may change the
2583 result of the operation due to rounding.
2586 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2587 Same as -fassociative-math for expressions which include division.
2589 ; Nonzero means that unsafe floating-point math optimizations are allowed
2590 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2591 ; are allowed to assume that their arguments and results are "normal"
2592 ; (e.g., nonnegative for SQRT).
2593 funsafe-math-optimizations
2594 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2595 Allow math optimizations that may violate IEEE or ISO standards.
2598 Common Report Var(flag_unswitch_loops) Optimization
2599 Perform loop unswitching.
2602 Common Report Var(flag_split_loops) Optimization
2603 Perform loop splitting.
2606 Common Report Var(flag_unwind_tables) Optimization
2607 Just generate unwind tables for exception handling.
2610 Common Driver Negative(fuse-ld=gold)
2611 Use the bfd linker instead of the default linker.
2614 Common Driver Negative(fuse-ld=bfd)
2615 Use the gold linker instead of the default linker.
2618 Common Undocumented Var(flag_use_linker_plugin)
2620 ; Positive if we should track variables, negative if we should run
2621 ; the var-tracking pass only to discard debug annotations, zero if
2622 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2623 ; will be set according to optimize, debug_info_level and debug_hooks
2624 ; in process_options ().
2626 Common Report Var(flag_var_tracking) Init(2) Optimization
2627 Perform variable tracking.
2629 ; Positive if we should track variables at assignments, negative if
2630 ; we should run the var-tracking pass only to discard debug
2631 ; annotations. When flag_var_tracking_assignments ==
2632 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2633 fvar-tracking-assignments
2634 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2635 Perform variable tracking by annotating assignments.
2637 ; Nonzero if we should toggle flag_var_tracking_assignments after
2638 ; processing options and computing its default. */
2639 fvar-tracking-assignments-toggle
2640 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2641 Toggle -fvar-tracking-assignments.
2643 ; Positive if we should track uninitialized variables, negative if
2644 ; we should run the var-tracking pass only to discard debug
2645 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2646 ; will be set according to flag_var_tracking.
2647 fvar-tracking-uninit
2648 Common Report Var(flag_var_tracking_uninit) Optimization
2649 Perform variable tracking and also tag variables that are uninitialized.
2652 Common Report Var(flag_tree_vectorize) Optimization
2653 Enable vectorization on trees.
2655 ftree-vectorizer-verbose=
2656 Common Joined RejectNegative Ignore
2657 Does nothing. Preserved for backward compatibility.
2659 ftree-loop-vectorize
2660 Common Report Var(flag_tree_loop_vectorize) Optimization
2661 Enable loop vectorization on trees.
2664 Common Report Var(flag_tree_slp_vectorize) Optimization
2665 Enable basic block vectorization (SLP) on trees.
2668 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2669 Specifies the cost model for vectorization.
2672 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2673 Specifies the vectorization cost model for code marked with a simd directive.
2676 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2679 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2682 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2685 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2688 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2689 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2692 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2693 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2695 ftree-vect-loop-version
2697 Does nothing. Preserved for backward compatibility.
2700 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2701 Enable copy propagation of scalar-evolution information.
2703 ; -fverbose-asm causes extra commentary information to be produced in
2704 ; the generated assembly code (to make it more readable). This option
2705 ; is generally only of use to those who actually need to read the
2706 ; generated assembly code (perhaps while debugging the compiler itself).
2707 ; -fno-verbose-asm, the default, causes the extra information
2708 ; to not be added and is useful when comparing two assembler files.
2710 Common Report Var(flag_verbose_asm)
2711 Add extra commentary to assembler output.
2714 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2715 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2718 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2721 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2724 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2727 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2730 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2733 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2734 Validate vtable pointers before using them.
2737 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2740 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2743 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2746 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2749 Common Var(flag_vtv_counts)
2750 Output vtable verification counters.
2753 Common Var(flag_vtv_debug)
2754 Output vtable verification pointer sets information.
2757 Common Report Var(flag_value_profile_transformations) Optimization
2758 Use expression value profiles in optimizations.
2761 Common Report Var(flag_web) Init(2) Optimization
2762 Construct webs and split unrelated uses of single variable.
2764 ftree-builtin-call-dce
2765 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2766 Enable conditional dead code elimination for builtin calls.
2769 Common Report Var(flag_whole_program) Init(0)
2770 Perform whole program optimizations.
2773 Common Report Var(flag_wrapv) Optimization
2774 Assume signed arithmetic overflow wraps around.
2776 fzero-initialized-in-bss
2777 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2778 Put zero initialized data in the bss section.
2781 Common JoinedOrMissing
2782 Generate debug information in default format.
2785 Common JoinedOrMissing Negative(gdwarf)
2786 Generate debug information in COFF format.
2789 Common JoinedOrMissing Negative(gdwarf-)
2790 Generate debug information in default version of DWARF format.
2793 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2794 Generate debug information in DWARF v2 (or later) format.
2797 Common JoinedOrMissing
2798 Generate debug information in default extended format.
2801 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2802 Don't generate DWARF pubnames and pubtypes sections.
2805 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2806 Generate DWARF pubnames and pubtypes sections.
2809 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2810 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2812 gno-record-gcc-switches
2813 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2814 Don't record gcc command line switches in DWARF DW_AT_producer.
2816 grecord-gcc-switches
2817 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2818 Record gcc command line switches in DWARF DW_AT_producer.
2821 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2822 Don't generate debug information in separate .dwo files.
2825 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2826 Generate debug information in separate .dwo files.
2829 Common JoinedOrMissing Negative(gstabs+)
2830 Generate debug information in STABS format.
2833 Common JoinedOrMissing Negative(gvms)
2834 Generate debug information in extended STABS format.
2837 Common RejectNegative Var(dwarf_strict,0) Init(0)
2838 Emit DWARF additions beyond selected version.
2841 Common Report RejectNegative Var(dwarf_strict,1)
2842 Don't emit DWARF additions beyond selected version.
2845 Common Report Var(flag_gtoggle)
2846 Toggle debug information generation.
2849 Common JoinedOrMissing Negative(gxcoff)
2850 Generate debug information in VMS format.
2853 Common JoinedOrMissing Negative(gxcoff+)
2854 Generate debug information in XCOFF format.
2857 Common JoinedOrMissing Negative(gcoff)
2858 Generate debug information in extended XCOFF format.
2861 Name(compressed_debug_sections) Type(int)
2863 ; Since -gz= is completely handled in specs, the values aren't used and we
2864 ; assign arbitrary constants.
2866 Enum(compressed_debug_sections) String(none) Value(0)
2869 Enum(compressed_debug_sections) String(zlib) Value(1)
2872 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2876 Generate compressed debug sections.
2879 Common Driver Joined Enum(compressed_debug_sections)
2880 -gz=<format> Generate compressed debug sections in format <format>.
2883 Driver Joined Separate
2886 Common Joined Var(plugindir_string) Init(0)
2887 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2890 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2891 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2894 Driver Joined Separate
2899 no-canonical-prefixes
2912 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2913 -o <file> Place output into <file>.
2916 Common Var(profile_flag)
2917 Enable function profiling.
2920 Driver Var(pass_exit_codes)
2923 Common Alias(Wpedantic)
2926 Common Var(flag_pedantic_errors)
2927 Like -pedantic but issue them as errors.
2933 Driver Var(use_pipes)
2936 Driver JoinedOrMissing Var(print_file_name)
2938 print-libgcc-file-name
2941 print-multi-directory
2942 Driver Var(print_multi_directory)
2945 Driver Var(print_multi_lib)
2947 print-multi-os-directory
2948 Driver Var(print_multi_os_directory)
2951 Driver Var(print_multiarch)
2954 Driver JoinedOrMissing Var(print_prog_name)
2957 Driver Var(print_search_dirs)
2960 Driver Var(print_sysroot)
2962 print-sysroot-headers-suffix
2963 Driver Var(print_sysroot_headers_suffix)
2966 Common Var(quiet_flag) RejectDriver
2967 Do not display functions compiled or elapsed time.
2985 Driver Var(report_times)
2988 Driver JoinedOrMissing
2991 Driver Joined Separate
2995 ; C option, but driver must not handle as "-u ndef".
2998 Common Driver Var(verbose_flag)
2999 Enable verbose output.
3002 Common Var(version_flag) RejectDriver
3003 Display the compiler's version.
3006 Common Var(inhibit_warnings)
3010 Driver Separate Var(wrapper_string)
3013 Driver Joined Separate
3016 Driver RejectNegative Negative(pie)
3017 Create a shared library.
3023 Driver Separate Alias(specs=)
3036 ; Documented for Fortran, but always accepted by driver.
3043 ; Documented for Go, but always accepted by driver.
3061 Driver RejectNegative Negative(shared)
3062 Don't create a position independent executable.
3065 Driver RejectNegative Negative(no-pie)
3066 Create a position independent executable.
3069 Driver Joined Separate
3072 Common Report Var(flag_ipa_ra) Optimization
3073 Use caller save register across calls if possible.
3075 ; This comment is to ensure we retain the blank line above.