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 ; Nonzero if subexpressions must be evaluated from left-to-right.
63 int flag_evaluation_order = 0
65 ; Language specific warning pass for unused results.
67 bool flag_warn_unused_result = false
72 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
76 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
78 int flag_generate_offload = 0
80 ; True to warn about any objects definitions whose size is larger
81 ; than N bytes. Also want about function definitions whose returned
82 ; values are larger than N bytes, where N is 'larger_than_size'.
87 HOST_WIDE_INT larger_than_size
89 ; True to warn about any function whose frame size is larger
92 bool warn_frame_larger_than
95 HOST_WIDE_INT frame_larger_than_size
97 ; Nonzero means we should be saving declaration info into a .X file.
99 int flag_gen_aux_info = 0
101 ; Nonzero if we are compiling code for a shared library, zero for
106 ; These two are really VEC(char_p,heap) *.
109 void *flag_instrument_functions_exclude_functions
112 void *flag_instrument_functions_exclude_files
114 ; Generic structs (e.g. templates not explicitly specialized)
115 ; may not have a compilation unit associated with them, and so
116 ; may need to be treated differently from ordinary structs.
118 ; Structs only handled by reference (indirectly), will also usually
119 ; not need as much debugging information.
122 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
125 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
127 ; True if we should exit after parsing options.
129 bool exit_after_options
131 ; Type(s) of debugging information we are producing (if any). See
132 ; flag-types.h for the definitions of the different possible types of
133 ; debugging information.
135 enum debug_info_type write_symbols = NO_DEBUG
137 ; Level of debugging information we are producing. See flag-types.h
138 ; for the definitions of the different possible levels.
140 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
142 ; Nonzero means use GNU-only extensions in the generated symbolic
143 ; debugging information. Currently, this only has an effect when
144 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
146 bool use_gnu_debug_info_extensions
148 ; Original value of maximum field alignment in bytes, specified via
149 ; -fpack-struct=<value>.
151 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
153 ; Type of stack check.
155 enum stack_check_type flag_stack_check = NO_STACK_CHECK
157 ; True if stack usage information needs to be computed.
159 bool flag_stack_usage_info = false
161 ; -dA causes debug commentary information to be produced in
162 ; the generated assembly code (to make it more readable). This option
163 ; is generally only of use to those who actually need to read the
164 ; generated assembly code (perhaps while debugging the compiler itself).
165 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
166 ; to be a catchall for printing debug information in the assembler file.
171 ; Balance between GNAT encodings and standard DWARF to emit.
173 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
175 ; -dP causes the rtl to be emitted as a comment in assembly.
177 int flag_dump_rtl_in_asm
179 ; Whether -da was passed (used only in handle_common_deferred_options).
181 bool flag_dump_all_passed
183 ; Other flags saying which kinds of debugging dump have been requested.
186 int rtl_dump_and_exit
189 int flag_print_asm_name
191 ; Name of top-level original source file (what was input to cpp).
192 ; This comes from the #-command at the beginning of the actual input.
193 ; If there isn't any there, then this is the cc1 input file name.
195 const char *main_input_filename
197 ; Pointer to base name in main_input_filename, with directories and a
198 ; single final extension removed, and the length of this base
202 const char *main_input_basename
205 int main_input_baselength
207 ; Which options have been printed by --help.
211 ; Which enums have been printed by --help. 0 = not printed, no
212 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
215 char *help_enum_printed
217 ; The number of columns for --help output.
219 unsigned int help_columns
221 ; Whether this options structure has been through finish_options
223 bool flag_opts_finished
225 ; What the sanitizer should instrument
227 unsigned int flag_sanitize
229 ; What sanitizers should recover from errors
231 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
233 fsanitize-coverage=trace-pc
234 Common Report Var(flag_sanitize_coverage)
235 Enable coverage-guided fuzzing code instrumentation.
236 Inserts call to __sanitizer_cov_trace_pc into every basic block.
238 ; Flag whether a prefix has been added to dump_base_name
240 bool dump_base_name_prefixed = false
242 ; Flag whether HSA generation has been explicitely disabled
244 bool flag_disable_hsa = false
256 Driver Alias(coverage)
262 Common Separate Alias(d)
265 Common Joined Alias(d)
268 Common Separate Alias(dumpbase)
271 Common Separate Alias(dumpdir)
274 Driver Separate Alias(e)
277 Driver Joined Alias(e)
280 Common Warning Alias(Wextra)
283 Driver Separate Alias(Xassembler)
286 Driver JoinedOrMissing Alias(Xassembler)
289 Driver Separate Alias(Xlinker)
292 Driver JoinedOrMissing Alias(Xlinker)
295 Driver Separate Alias(u)
298 Driver Joined Alias(u)
301 Common Driver Var(help_flag)
302 Display this information.
305 Common Driver Report Joined
306 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
309 Driver Separate Alias(x)
312 Driver Joined Alias(x)
315 Driver Separate Alias(L)
318 Driver Joined Alias(L)
320 -no-canonical-prefixes
321 Driver Alias(no-canonical-prefixes)
323 -no-standard-libraries
324 Driver Alias(nostdlib)
327 Driver Var(no_sysroot_suffix)
336 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
339 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
342 Driver Alias(pass-exit-codes)
345 Common Alias(Wpedantic)
348 Common Alias(pedantic-errors)
357 Driver Separate Alias(B)
360 Driver JoinedOrMissing Alias(B)
366 Driver Separate Alias(print-file-name=)
369 Driver JoinedOrMissing Alias(print-file-name=)
371 -print-libgcc-file-name
372 Driver Alias(print-libgcc-file-name)
374 -print-multi-directory
375 Driver Alias(print-multi-directory)
378 Driver Alias(print-multi-lib)
380 -print-multi-os-directory
381 Driver Alias(print-multi-os-directory)
384 Driver Alias(print-multiarch)
387 Driver Separate Alias(print-prog-name=)
390 Driver JoinedOrMissing Alias(print-prog-name=)
393 Driver Alias(print-search-dirs)
396 Driver Alias(print-sysroot)
398 -print-sysroot-headers-suffix
399 Driver Alias(print-sysroot-headers-suffix)
405 Driver Alias(save-temps)
411 Driver Separate Alias(specs=)
414 Driver Joined Alias(specs=)
420 Driver Alias(symbolic)
424 Alias for --help=target.
432 ;; The driver used to convert options such as --help into forms such
433 ;; as -fhelp; the following four entries are for compatibility with
434 ;; any direct uses of those (undocumented) -f forms
436 Common Driver Alias(-help)
439 Common Driver Joined Alias(-help=)
442 Common Driver Alias(-target-help)
445 Common Driver Alias(-version)
449 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
452 Common Joined Alias(-param)
455 Driver Separate Alias(-sysroot=)
458 Driver JoinedOrMissing
464 Driver Joined Separate
470 Driver Joined Separate
476 Common JoinedOrMissing Optimization
477 -O<number> Set optimization level to <number>.
481 Optimize for space rather than speed.
485 Optimize for speed disregarding exact standards compliance.
489 Optimize for debugging experience rather than speed or size.
501 Driver Joined Separate
507 Driver Joined Separate
528 Common RejectNegative Warning Alias(Wextra)
529 This switch is deprecated; use -Wextra instead.
532 Driver JoinedOrMissing
535 Driver JoinedOrMissing
538 Driver JoinedOrMissing
541 Common Var(warn_aggregate_return) Warning
542 Warn about returning structures, unions or arrays.
544 Waggressive-loop-optimizations
545 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
546 Warn if a loop with constant number of iterations triggers undefined behavior.
549 Common Var(warn_array_bounds) Warning
550 Warn if an array is accessed out of bounds.
553 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning
554 Warn if an array is accessed out of bounds.
557 Common Var(warn_attributes) Init(1) Warning
558 Warn about inappropriate attribute usage.
561 Common Var(warn_cast_align) Warning
562 Warn about pointer casts which increase alignment.
565 Common Var(warn_cpp) Init(1) Warning
566 Warn when a #warning directive is encountered.
568 Wdeprecated-declarations
569 Common Var(warn_deprecated_decl) Init(1) Warning
570 Warn about uses of __attribute__((deprecated)) declarations.
572 Wdisabled-optimization
573 Common Var(warn_disabled_optimization) Warning
574 Warn when an optimization pass is disabled.
577 Common Var(warnings_are_errors)
578 Treat all warnings as errors.
582 Treat specified warning as error.
585 Common Var(extra_warnings) Warning
586 Print extra (possibly unwanted) warnings.
589 Common Var(flag_fatal_errors)
590 Exit on the first error occurred.
593 Common RejectNegative Joined UInteger Warning
594 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes.
597 Common Var(warn_free_nonheap_object) Init(1) Warning
598 Warn when attempting to free a non-heap object.
601 Common Var(warn_hsa) Init(1) Warning
602 Warn when a function cannot be expanded to HSAIL.
604 Wimplicit-fallthrough
605 Common Alias(Wimplicit-fallthrough=,3,0) Warning
607 Wimplicit-fallthrough=
608 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning
609 Warn when a switch case falls through.
612 Common Var(warn_inline) Warning
613 Warn when an inlined function cannot be inlined.
615 Winvalid-memory-model
616 Common Var(warn_invalid_memory_model) Init(1) Warning
617 Warn when an atomic memory model parameter is known to be outside the valid range.
620 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
623 Common RejectNegative Joined UInteger Warning
624 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
627 Var(warn_nonnull_compare) Warning
628 Warn if comparing pointer parameter with nonnull attribute with NULL.
631 Common Var(warn_null_dereference) Warning
632 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
634 Wunsafe-loop-optimizations
635 Common Var(warn_unsafe_loop_optimizations) Warning
636 Warn if the loop cannot be optimized due to nontrivial assumptions.
639 Common Warning Alias(Wsuggest-attribute=noreturn)
642 Common Var(warn_odr_violations) Init(1) Warning
643 Warn about some C++ One Definition Rule violations during link time optimization.
646 Common Var(warn_overflow) Init(1) Warning
647 Warn about overflow in arithmetic expressions.
650 Common Var(warn_lto_type_mismatch) Init(1) Warning
651 During link time optimization warn about mismatched types of global declarations.
654 Common Var(warn_packed) Warning
655 Warn when the packed attribute has no effect on struct layout.
658 Common Var(warn_padded) Warning
659 Warn when padding is required to align structure members.
662 Common Var(pedantic) Init(0) Warning
663 Issue warnings needed for strict compliance to the standard.
666 Common Var(warn_return_local_addr) Init(1) Warning
667 Warn about returning a pointer/reference to a local or temporary variable.
670 Common Var(warn_shadow) Warning
671 Warn when one variable shadows another. Same as -Wshadow=global.
674 Common Warning Alias(Wshadow)
675 Warn when one variable shadows another (globally).
678 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
679 Warn when one local variable shadows another local variable or parameter.
682 Common Warning Undocumented Alias(Wshadow=local)
684 Wshadow=compatible-local
685 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
686 Warn when one local variable shadows another local variable or parameter of compatible type.
688 Wshadow-compatible-local
689 Common Warning Undocumented Alias(Wshadow=compatible-local)
692 Common Var(warn_stack_protect) Warning
693 Warn when not issuing stack smashing protection for some reason.
696 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
697 Warn if stack usage might be larger than specified amount.
701 Warn about code which might break strict aliasing rules.
704 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
705 Warn about code which might break strict aliasing rules.
709 Warn about optimizations that assume that signed overflow is undefined.
712 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
713 Warn about optimizations that assume that signed overflow is undefined.
715 Wsuggest-attribute=const
716 Common Var(warn_suggest_attribute_const) Warning
717 Warn about functions which might be candidates for __attribute__((const)).
719 Wsuggest-attribute=pure
720 Common Var(warn_suggest_attribute_pure) Warning
721 Warn about functions which might be candidates for __attribute__((pure)).
723 Wsuggest-attribute=noreturn
724 Common Var(warn_suggest_attribute_noreturn) Warning
725 Warn about functions which might be candidates for __attribute__((noreturn)).
728 Common Var(warn_suggest_final_types) Warning
729 Warn about C++ polymorphic types where adding final keyword would improve code quality.
731 Wsuggest-final-methods
732 Common Var(warn_suggest_final_methods) Warning
733 Warn about C++ virtual methods where adding final keyword would improve code quality.
736 Common Var(warn_switch_unreachable) Warning Init(1)
737 Warn about statements between switch's controlling expression and the first
741 Common Var(warn_system_headers) Warning
742 Do not suppress warnings from system headers.
745 Common Var(warn_trampolines) Warning
746 Warn whenever a trampoline is generated.
749 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
750 Warn if a comparison is always true or always false due to the limited range of the data type.
753 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
754 Warn about uninitialized automatic variables.
757 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
758 Warn about maybe uninitialized automatic variables.
761 Common Ignore Warning
762 Does nothing. Preserved for backward compatibility.
765 Common Var(warn_unused) Init(0) Warning
766 Enable all -Wunused- warnings.
768 Wunused-but-set-parameter
769 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
770 Warn when a function parameter is only set, otherwise unused.
772 Wunused-but-set-variable
773 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
774 Warn when a variable is only set, otherwise unused.
777 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
778 Warn when a function is unused.
781 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
782 Warn when a label is unused.
785 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
786 Warn when a function parameter is unused.
789 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
790 Warn when an expression value is unused.
793 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
794 Warn when a variable is unused.
797 Common Var(warn_coverage_mismatch) Init(1) Warning
798 Warn in case profiles in -fprofile-use do not match.
800 Wvector-operation-performance
801 Common Var(warn_vector_operation_performance) Warning
802 Warn when a vector operation is compiled outside the SIMD.
817 Common Separate Var(aux_info_file_name)
818 -aux-info <file> Emit declaration information into <file>.
821 Common Joined Alias(aux-info)
824 Common Separate RejectDriver Var(aux_base_name)
827 Common Separate RejectDriver
837 -d<letters> Enable dumps from specific passes of the compiler.
840 Common Separate Var(dump_base_name)
841 -dumpbase <file> Set the file basename to be used for dumps.
844 Common Separate Var(dump_dir_name)
845 -dumpdir <dir> Set the directory name to be used for dumps.
857 Driver Joined Separate
859 ; This option has historically been passed down to the linker by an
860 ; accident of a %{e*} spec, so ensure it continues to be passed down
861 ; as a single option. The supported option for this purpose is
862 ; -rdynamic. See PR 47390.
866 ; The version of the C++ ABI in use. The following values are allowed:
868 ; 0: The version of the ABI believed most conformant with the C++ ABI
869 ; specification. This ABI may change as bugs are discovered and fixed.
870 ; Therefore, 0 will not necessarily indicate the same ABI in different
873 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
875 ; 2: The version of the ABI first used in G++ 3.4, and the default
878 ; 3: The version of the ABI that fixes the missing underscore
879 ; in template non-type arguments of pointer type.
881 ; 4: The version of the ABI that introduces unambiguous mangling of
882 ; vector types. First selectable in G++ 4.5.
884 ; 5: The version of the ABI that ignores attribute const/noreturn
885 ; in function pointer mangling, and corrects mangling of decltype and
886 ; function parameters used in other parameters and the return type.
887 ; First selectable in G++ 4.6.
889 ; 6: The version of the ABI that doesn't promote scoped enums to int and
890 ; changes the mangling of template argument packs, const/static_cast,
891 ; prefix ++ and --, and a class scope function used as a template
893 ; First selectable in G++ 4.7.
895 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
896 ; corrects the mangling of lambdas in default argument scope.
897 ; First selectable in G++ 4.8.
899 ; 8: The version of the ABI that corrects the substitution behavior of
900 ; function types with function-cv-qualifiers.
901 ; First selectable in G++ 4.9 and default in G++ 5.
903 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
904 ; First selectable and default in G++ 5.2.
906 ; 10: The version of the ABI that mangles attributes that affect type
907 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
908 ; Default in G++ 6 (set in c_common_post_options).
910 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
911 ; and introduces new inheriting constructor handling.
914 ; Additional positive integers will be assigned as new versions of
915 ; the ABI become the default version of the ABI.
917 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
918 The version of the C++ ABI in use.
920 faggressive-loop-optimizations
921 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
922 Aggressively optimize loops using language constraints.
925 Common Report Var(align_functions,0) Optimization UInteger
926 Align the start of functions.
929 Common RejectNegative Joined UInteger Var(align_functions)
932 Common Report Var(align_jumps,0) Optimization UInteger
933 Align labels which are only reached by jumping.
936 Common RejectNegative Joined UInteger Var(align_jumps)
939 Common Report Var(align_labels,0) Optimization UInteger
943 Common RejectNegative Joined UInteger Var(align_labels)
946 Common Report Var(align_loops,0) Optimization UInteger
947 Align the start of loops.
950 Common RejectNegative Joined UInteger Var(align_loops)
954 Does nothing. Preserved for backward compatibility.
958 Does nothing. Preserved for backward compatibility.
960 fargument-noalias-global
962 Does nothing. Preserved for backward compatibility.
964 fargument-noalias-anything
966 Does nothing. Preserved for backward compatibility.
969 Common Driver Report Joined
970 Select what to sanitize.
973 Common Joined RejectNegative Var(common_deferred_options) Defer
974 -fasan-shadow-offset=<number> Use custom shadow memory offset.
977 Common Joined RejectNegative Var(common_deferred_options) Defer
978 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
979 in user-defined sections.
983 After diagnosing undefined behavior attempt to continue execution.
987 This switch is deprecated; use -fsanitize-recover= instead.
989 fsanitize-address-use-after-scope
990 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
992 fsanitize-undefined-trap-on-error
993 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
994 Use trap instead of a library function for undefined behavior sanitization.
996 fasynchronous-unwind-tables
997 Common Report Var(flag_asynchronous_unwind_tables) Optimization
998 Generate unwind tables that are exact at each instruction boundary.
1001 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1002 Generate auto-inc/dec instructions.
1005 Common Report Var(flag_auto_profile)
1006 Use sample profile information for call graph node weights. The default
1007 profile file is fbdata.afdo in 'pwd'.
1010 Common Joined RejectNegative Var(auto_profile_file)
1011 Use sample profile information for call graph node weights. The profile
1012 file is specified in the argument.
1014 ; -fcheck-bounds causes gcc to generate array bounds checks.
1015 ; For C, C++ and ObjC: defaults off.
1016 ; For Java: defaults to on.
1017 ; For Fortran: defaults to off.
1019 Common Report Var(flag_bounds_check)
1020 Generate code to check bounds before indexing arrays.
1023 Common Report Var(flag_branch_on_count_reg) Optimization
1024 Replace add, compare, branch with branch on count register.
1026 fbranch-probabilities
1027 Common Report Var(flag_branch_probabilities) Optimization
1028 Use profiling information for branch probabilities.
1030 fbranch-target-load-optimize
1031 Common Report Var(flag_branch_target_load_optimize) Optimization
1032 Perform branch target load optimization before prologue / epilogue threading.
1034 fbranch-target-load-optimize2
1035 Common Report Var(flag_branch_target_load_optimize2) Optimization
1036 Perform branch target load optimization after prologue / epilogue threading.
1039 Common Report Var(flag_btr_bb_exclusive) Optimization
1040 Restrict target load migration not to re-use registers in any basic block.
1043 Common Joined RejectNegative Var(common_deferred_options) Defer
1044 -fcall-saved-<register> Mark <register> as being preserved across functions.
1047 Common Joined RejectNegative Var(common_deferred_options) Defer
1048 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1050 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1051 ; be saved across function calls, if that produces overall better code.
1052 ; Optional now, so people can test it.
1054 Common Report Var(flag_caller_saves) Optimization
1055 Save registers around function calls.
1058 Common Report Var(flag_check_data_deps)
1059 This switch is deprecated; do not use.
1062 Common Var(flag_check_new)
1063 Check the return value of new in C++.
1066 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1067 Perform internal consistency checkings.
1070 Common Joined RejectNegative UInteger Var(flag_checking)
1071 Perform internal consistency checkings.
1074 Common Report Var(flag_code_hoisting) Optimization
1075 Enable code hoisting.
1077 fcombine-stack-adjustments
1078 Common Report Var(flag_combine_stack_adjustments) Optimization
1079 Looks for opportunities to reduce stack adjustments and stack references.
1082 Common Report Var(flag_no_common,0)
1083 Do not put uninitialized globals in the common section.
1087 ; Converted by the driver to -fcompare-debug= options.
1090 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1091 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1093 fcompare-debug-second
1094 Common Driver RejectNegative Var(flag_compare_debug)
1095 Run only the second compilation of -fcompare-debug.
1098 Common Report Var(flag_compare_elim_after_reload) Optimization
1099 Perform comparison elimination after register allocation has finished.
1102 Common Var(flag_conserve_stack) Optimization
1103 Do not perform optimizations increasing noticeably stack usage.
1106 Common Report Var(flag_cprop_registers) Optimization
1107 Perform a register copy-propagation optimization pass.
1110 Common Report Var(flag_crossjumping) Optimization
1111 Perform cross-jumping optimization.
1114 Common Report Var(flag_cse_follow_jumps) Optimization
1115 When running CSE, follow jumps to their targets.
1119 Does nothing. Preserved for backward compatibility.
1122 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1123 Omit range reduction step when performing complex division.
1126 Common Report Var(flag_cx_fortran_rules) Optimization
1127 Complex multiplication and division follow Fortran rules.
1130 Common Report Var(flag_data_sections)
1131 Place data items into their own section.
1134 Common Report Var(common_deferred_options) Defer
1135 List all available debugging counters with their limits and counts.
1138 Common RejectNegative Joined Var(common_deferred_options) Defer
1139 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1142 Common Joined RejectNegative Var(common_deferred_options) Defer
1143 Map one directory name to another in debug information.
1145 fdebug-types-section
1146 Common Report Var(flag_debug_types_section) Init(0)
1147 Output .debug_types section when using DWARF v4 debuginfo.
1149 ; Nonzero for -fdefer-pop: don't pop args after each function call
1150 ; instead save them up to pop many calls' args with one insns.
1152 Common Report Var(flag_defer_pop) Optimization
1153 Defer popping functions args from stack until later.
1156 Common Report Var(flag_delayed_branch) Optimization
1157 Attempt to fill delay slots of branch instructions.
1159 fdelete-dead-exceptions
1160 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1161 Delete dead instructions that may throw exceptions.
1163 fdelete-null-pointer-checks
1164 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1165 Delete useless null pointer checks.
1167 fdevirtualize-at-ltrans
1168 Common Report Var(flag_ltrans_devirtualize)
1169 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1171 fdevirtualize-speculatively
1172 Common Report Var(flag_devirtualize_speculatively) Optimization
1173 Perform speculative devirtualization.
1176 Common Report Var(flag_devirtualize) Optimization
1177 Try to convert virtual calls to direct ones.
1179 fdiagnostics-show-location=
1180 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1181 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1183 ; Required for these enum values.
1188 Name(diagnostic_prefixing_rule) Type(int)
1191 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1194 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1196 fdiagnostics-show-caret
1197 Common Var(flag_diagnostics_show_caret) Init(1)
1198 Show the source line with a caret indicating the column.
1201 Common Alias(fdiagnostics-color=,always,never)
1205 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1206 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1208 ; Required for these enum values.
1213 Name(diagnostic_color_rule) Type(int)
1216 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1219 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1222 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1224 fdiagnostics-parseable-fixits
1225 Common Var(flag_diagnostics_parseable_fixits)
1226 Print fixit hints in machine-readable form.
1228 fdiagnostics-generate-patch
1229 Common Var(flag_diagnostics_generate_patch)
1230 Print fix-it hints to stderr in unified diff format.
1232 fdiagnostics-show-option
1233 Common Var(flag_diagnostics_show_option) Init(1)
1234 Amend appropriate diagnostic messages with the command line option that controls them.
1237 Common Joined RejectNegative Var(common_deferred_options) Defer
1238 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1241 Common Joined RejectNegative Var(common_deferred_options) Defer
1242 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1245 Common Joined RejectNegative Var(common_deferred_options) Defer
1246 -fdump-<type> Dump various compiler internals to a file.
1249 Driver RejectNegative
1252 Common RejectNegative Joined Var(flag_dump_final_insns)
1253 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1256 Common RejectNegative Joined Var(flag_dump_go_spec)
1257 -fdump-go-spec=filename Write all declarations to file as Go code.
1260 Common Report Var(flag_dump_noaddr)
1261 Suppress output of addresses in debugging dumps.
1264 Common Driver Var(flag_report_bug)
1265 Collect and dump debug information into temporary file if ICE in C/C++
1268 fdump-internal-locations
1269 Common Var(flag_dump_locations) Init(0)
1270 Dump detailed information on GCC's internal representation of source code locations.
1273 Common Var(flag_dump_passes) Init(0)
1274 Dump optimization passes.
1277 Common Report Var(flag_dump_unnumbered)
1278 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1280 fdump-unnumbered-links
1281 Common Report Var(flag_dump_unnumbered_links)
1282 Suppress output of previous and next insn numbers in debugging dumps.
1285 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1286 Enable CFI tables via GAS assembler directives.
1289 Common Report Var(flag_early_inlining) Init(1) Optimization
1290 Perform early inlining.
1292 feliminate-dwarf2-dups
1293 Common Report Var(flag_eliminate_dwarf2_dups)
1294 Perform DWARF duplicate elimination.
1297 Common Report Var(flag_ipa_sra) Init(0) Optimization
1298 Perform interprocedural reduction of aggregates.
1300 feliminate-unused-debug-symbols
1301 Common Report Var(flag_debug_only_used_symbols)
1302 Perform unused symbol elimination in debug info.
1304 feliminate-unused-debug-types
1305 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1306 Perform unused type elimination in debug info.
1308 femit-class-debug-always
1309 Common Report Var(flag_emit_class_debug_always) Init(0)
1310 Do not suppress C++ class debug information.
1313 Common Report Var(flag_exceptions) Optimization
1314 Enable exception handling.
1316 fexpensive-optimizations
1317 Common Report Var(flag_expensive_optimizations) Optimization
1318 Perform a number of minor, expensive optimizations.
1321 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1322 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1325 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1328 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1331 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1337 Common Var(flag_fat_lto_objects)
1338 Output lto objects containing both the intermediate language and binary output.
1341 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1342 Assume no NaNs or infinities are generated.
1345 Common Joined RejectNegative Var(common_deferred_options) Defer
1346 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1349 Common Report Var(flag_float_store) Optimization
1350 Don't allocate floats and doubles in extended-precision registers.
1354 Does nothing. Preserved for backward compatibility.
1357 Common Report Var(flag_forward_propagate) Optimization
1358 Perform a forward propagation pass on RTL.
1361 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1362 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1365 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1368 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1370 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1372 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1375 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1377 ffp-int-builtin-inexact
1378 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1379 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1381 ; Nonzero means don't put addresses of constant functions in registers.
1382 ; Used for compiling the Unix kernel, where strange substitutions are
1383 ; done on the assembly output.
1385 Common Report Var(flag_no_function_cse,0) Optimization
1386 Allow function addresses to be held in registers.
1389 Common Report Var(flag_function_sections)
1390 Place each function into its own section.
1393 Common Report Var(flag_gcse) Optimization
1394 Perform global common subexpression elimination.
1397 Common Report Var(flag_gcse_lm) Init(1) Optimization
1398 Perform enhanced load motion during global common subexpression elimination.
1401 Common Report Var(flag_gcse_sm) Init(0) Optimization
1402 Perform store motion after global common subexpression elimination.
1405 Common Report Var(flag_gcse_las) Init(0) Optimization
1406 Perform redundant load after store elimination in global common subexpression
1410 Common Report Var(flag_gcse_after_reload) Optimization
1411 Perform global common subexpression elimination after register allocation has
1415 Name(dwarf_gnat_encodings) Type(int)
1418 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1421 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1424 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1427 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1428 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1430 ; This option is not documented yet as its semantics will change.
1432 Common Report Var(flag_graphite) Optimization
1433 Enable in and out of Graphite representation.
1436 Common Report Var(flag_graphite_identity) Optimization
1437 Enable Graphite Identity transformation.
1439 fhoist-adjacent-loads
1440 Common Report Var(flag_hoist_adjacent_loads) Optimization
1441 Enable hoisting adjacent loads to encourage generating conditional move
1445 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1446 ; Always keep a pointer to a live memory block
1448 floop-parallelize-all
1449 Common Report Var(flag_loop_parallelize_all) Optimization
1450 Mark all loops as parallel.
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.
1461 Common Alias(floop-nest-optimize)
1462 Enable loop nest transforms. Same as -floop-nest-optimize.
1464 floop-unroll-and-jam
1465 Common Alias(floop-nest-optimize)
1466 Enable loop nest transforms. Same as -floop-nest-optimize.
1469 Common Report Var(flag_tm)
1470 Enable support for GNU transactional memory.
1473 Common Report Var(flag_gnu_unique) Init(1)
1474 Use STB_GNU_UNIQUE if supported by the assembler.
1478 Does nothing. Preserved for backward compatibility.
1481 Common Report Var(flag_loop_nest_optimize) Optimization
1482 Enable the loop nest optimizer.
1484 fstrict-volatile-bitfields
1485 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1486 Force bitfield accesses to match their type width.
1489 Common Report Var(flag_store_merging) Optimization
1490 Merge adjacent stores.
1492 fguess-branch-probability
1493 Common Report Var(flag_guess_branch_prob) Optimization
1494 Enable guessing of branch probabilities.
1496 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1497 ; Generate position-independent code for executables if possible
1498 ; On SVR4 targets, it also controls whether or not to emit a
1499 ; string identifying the compiler.
1501 Common Report Var(flag_no_ident,0)
1502 Process #ident directives.
1505 Common Report Var(flag_if_conversion) Optimization
1506 Perform conversion of conditional jumps to branchless equivalents.
1509 Common Report Var(flag_if_conversion2) Optimization
1510 Perform conversion of conditional jumps to conditional execution.
1513 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1514 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1517 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1520 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1523 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1526 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1528 ftree-loop-if-convert
1529 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1530 Convert conditional jumps in innermost loops to branchless equivalents.
1532 ftree-loop-if-convert-stores
1533 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1534 Also if-convert conditional jumps containing memory writes.
1536 ; -finhibit-size-directive inhibits output of .size for ELF.
1537 ; This is used only for compiling crtstuff.c,
1538 ; and it may be extended to other effects
1539 ; needed for crtstuff.c on other systems.
1540 finhibit-size-directive
1541 Common Report Var(flag_inhibit_size_directive)
1542 Do not generate .size directives.
1545 Common Report Var(flag_indirect_inlining) Optimization
1546 Perform indirect inlining.
1548 ; General flag to enable inlining. Specifying -fno-inline will disable
1549 ; all inlining apart from always-inline functions.
1551 Common Report Var(flag_no_inline,0) Init(0) Optimization
1552 Enable inlining of function declared \"inline\", disabling disables all inlining.
1554 finline-small-functions
1555 Common Report Var(flag_inline_small_functions) Optimization
1556 Integrate functions into their callers when code size is known not to grow.
1559 Common Report Var(flag_inline_functions) Optimization
1560 Integrate functions not declared \"inline\" into their callers when profitable.
1562 finline-functions-called-once
1563 Common Report Var(flag_inline_functions_called_once) Optimization
1564 Integrate functions only required by their single caller.
1567 Common RejectNegative Joined Alias(finline-limit=)
1570 Common RejectNegative Joined UInteger
1571 -finline-limit=<number> Limit the size of inlined functions to <number>.
1574 Common Report Var(flag_inline_atomics) Init(1) Optimization
1575 Inline __atomic operations when a lock free instruction sequence is available.
1577 finstrument-functions
1578 Common Report Var(flag_instrument_function_entry_exit)
1579 Instrument function entry and exit with profiling calls.
1581 finstrument-functions-exclude-function-list=
1582 Common RejectNegative Joined
1583 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1585 finstrument-functions-exclude-file-list=
1586 Common RejectNegative Joined
1587 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1590 Common Report Var(flag_ipa_cp) Optimization
1591 Perform interprocedural constant propagation.
1594 Common Report Var(flag_ipa_cp_clone) Optimization
1595 Perform cloning to make Interprocedural constant propagation stronger.
1598 Common Report Var(flag_ipa_cp_alignment) Optimization
1599 Perform alignment discovery and propagation to make Interprocedural constant propagation stronger.
1602 Common Report Var(flag_ipa_bit_cp) Optimization
1603 Perform interprocedural bitwise constant propagation.
1606 Common Report Var(flag_ipa_profile) Init(0) Optimization
1607 Perform interprocedural profile propagation.
1610 Common Report Var(flag_ipa_pta) Init(0) Optimization
1611 Perform interprocedural points-to analysis.
1614 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1615 Discover pure and const functions.
1618 Common Report Var(flag_ipa_icf) Optimization
1619 Perform Identical Code Folding for functions and read-only variables.
1622 Common Report Var(flag_ipa_icf_functions) Optimization
1623 Perform Identical Code Folding for functions.
1626 Common Report Var(flag_ipa_icf_variables) Optimization
1627 Perform Identical Code Folding for variables.
1630 Common Report Var(flag_ipa_reference) Init(0) Optimization
1631 Discover readonly and non addressable static variables.
1635 Does nothing. Preserved for backward compatibility.
1639 Does nothing. Preserved for backward compatibility.
1642 Common Report Var(flag_ipa_vrp) Optimization
1643 Perform IPA Value Range Propagation.
1646 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1647 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1650 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1653 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1656 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1659 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1660 -fira-region=[one|all|mixed] Set regions for IRA.
1663 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1666 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1669 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1672 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1675 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1676 Use IRA based register pressure calculation
1677 in RTL hoist optimizations.
1680 Common Report Var(flag_ira_loop_pressure) Optimization
1681 Use IRA based register pressure calculation
1682 in RTL loop optimizations.
1684 fira-share-save-slots
1685 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1686 Share slots for saving different hard registers.
1688 fira-share-spill-slots
1689 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1690 Share stack slots for spilled pseudo-registers.
1693 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1694 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1697 Common Report Var(flag_ivopts) Init(1) Optimization
1698 Optimize induction variables on trees.
1701 Common Var(flag_jump_tables) Init(1) Optimization
1702 Use jump tables for sufficiently large switch statements.
1704 fkeep-inline-functions
1705 Common Report Var(flag_keep_inline_functions)
1706 Generate code for functions even if they are fully inlined.
1708 fkeep-static-functions
1709 Common Report Var(flag_keep_static_functions)
1710 Generate code for static functions even if they are never called.
1713 Common Report Var(flag_keep_static_consts) Init(1)
1714 Emit static const variables even if they are not used.
1717 Common Report Var(flag_leading_underscore) Init(-1)
1718 Give external symbols a leading underscore.
1722 Does nothing. Preserved for backward compatibility.
1725 Common Report Var(flag_lra_remat) Optimization
1726 Do CFG-sensitive rematerialization in LRA.
1730 Enable link-time optimization.
1733 Common RejectNegative Joined Var(flag_lto)
1734 Link-time optimization with number of parallel jobs or jobserver.
1737 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1740 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1743 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1746 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1749 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1752 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1755 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1756 Specify the algorithm to partition symbols and vars at linktime.
1758 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1759 flto-compression-level=
1760 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1761 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1763 flto-odr-type-merging
1764 Common Report Var(flag_lto_odr_type_mering) Init(1)
1765 Merge C++ types using One Definition Rule.
1768 Common Report Var(flag_lto_report) Init(0)
1769 Report various link-time optimization statistics.
1772 Common Report Var(flag_lto_report_wpa) Init(0)
1773 Report various link-time optimization statistics for WPA only.
1776 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1777 Set errno after built-in math functions.
1780 Common Joined RejectNegative UInteger Var(flag_max_errors)
1781 -fmax-errors=<number> Maximum number of errors to report.
1784 Common Report Var(mem_report)
1785 Report on permanent memory allocation.
1788 Common Report Var(mem_report_wpa)
1789 Report on permanent memory allocation in WPA only.
1791 ; This will attempt to merge constant section constants, if 1 only
1792 ; string constants and constants from constant pool, if 2 also constant
1794 fmerge-all-constants
1795 Common Report Var(flag_merge_constants,2) Init(1)
1796 Attempt to merge identical constants and constant variables.
1799 Common Report Var(flag_merge_constants,1)
1800 Attempt to merge identical constants across compilation units.
1802 fmerge-debug-strings
1803 Common Report Var(flag_merge_debug_strings) Init(1)
1804 Attempt to merge identical debug strings across compilation units.
1807 Common RejectNegative Joined UInteger
1808 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1811 Common Report Var(flag_modulo_sched) Optimization
1812 Perform SMS based modulo scheduling before the first scheduling pass.
1814 fmodulo-sched-allow-regmoves
1815 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1816 Perform SMS based modulo scheduling with register moves allowed.
1818 fmove-loop-invariants
1819 Common Report Var(flag_move_loop_invariants) Optimization
1820 Move loop invariant computations out of loops.
1823 Common Var(flag_dce) Init(1) Optimization
1824 Use the RTL dead code elimination pass.
1827 Common Var(flag_dse) Init(1) Optimization
1828 Use the RTL dead store elimination pass.
1830 freschedule-modulo-scheduled-loops
1831 Common Report Var(flag_resched_modulo_sched) Optimization
1832 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1834 fnon-call-exceptions
1835 Common Report Var(flag_non_call_exceptions) Optimization
1836 Support synchronous non-call exceptions.
1839 Common Driver Joined MissingArgError(options or targets missing after %qs)
1840 -foffload=<targets>=<options> Specify offloading targets and options for them.
1843 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1844 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1847 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1850 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1853 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1856 Common Report Var(flag_omit_frame_pointer) Optimization
1857 When possible do not generate stack frames.
1860 Common Report Var(flag_opt_info) Optimization
1861 Enable all optimization info dumps on stderr.
1864 Common Joined RejectNegative Var(common_deferred_options) Defer
1865 -fopt-info[-<type>=filename] Dump compiler optimization details.
1867 foptimize-register-move
1869 Does nothing. Preserved for backward compatibility.
1871 foptimize-sibling-calls
1872 Common Report Var(flag_optimize_sibling_calls) Optimization
1873 Optimize sibling and tail recursive calls.
1876 Common Report Var(flag_partial_inlining) Optimization
1877 Perform partial inlining.
1880 Common Report Var(pre_ipa_mem_report)
1881 Report on memory allocation before interprocedural optimization.
1883 fpost-ipa-mem-report
1884 Common Report Var(post_ipa_mem_report)
1885 Report on memory allocation before interprocedural optimization.
1888 Common Report Var(flag_pack_struct) Optimization
1889 Pack structure members together without holes.
1892 Common RejectNegative Joined UInteger Optimization
1893 -fpack-struct=<number> Set initial maximum structure member alignment.
1896 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1897 Return small aggregates in memory, not registers.
1900 Common Report Var(flag_peel_loops) Optimization
1901 Perform loop peeling.
1904 Common Report Var(flag_no_peephole,0) Optimization
1905 Enable machine specific peephole optimizations.
1908 Common Report Var(flag_peephole2) Optimization
1909 Enable an RTL peephole pass before sched2.
1912 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1913 Generate position-independent code if possible (large mode).
1916 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1917 Generate position-independent code for executables if possible (large mode).
1920 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1921 Generate position-independent code if possible (small mode).
1924 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1925 Generate position-independent code for executables if possible (small mode).
1928 Common Report Var(flag_plt) Init(1) Optimization
1929 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
1932 Common Joined RejectNegative Var(common_deferred_options) Defer
1933 Specify a plugin to load.
1936 Common Joined RejectNegative Var(common_deferred_options) Defer
1937 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
1939 fpredictive-commoning
1940 Common Report Var(flag_predictive_commoning) Optimization
1941 Run predictive commoning optimization.
1943 fprefetch-loop-arrays
1944 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1945 Generate prefetch instructions, if available, for arrays in loops.
1948 Common Report Var(profile_flag)
1949 Enable basic program profiling code.
1952 Common Report Var(profile_arc_flag)
1953 Insert arc-based program profiling code.
1956 Common Joined RejectNegative Var(profile_data_prefix)
1957 Set the top-level directory for storing the profile data.
1958 The default is 'pwd'.
1961 Common Report Var(flag_profile_correction)
1962 Enable correction of flow inconsistent profile data input.
1965 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
1966 -fprofile-update=[single|atomic] Set the profile update method.
1969 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
1972 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
1975 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
1979 Enable common options for generating profile info for profile feedback directed optimizations.
1982 Common Joined RejectNegative
1983 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
1986 Common Var(flag_profile_use)
1987 Enable common options for performing profile feedback directed optimizations.
1990 Common Joined RejectNegative
1991 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
1994 Common Report Var(flag_profile_values)
1995 Insert code to profile values of expressions.
1998 Common Report Var(profile_report)
1999 Report on consistency of profile.
2001 fprofile-reorder-functions
2002 Common Report Var(flag_profile_reorder_functions)
2003 Enable function reordering that improves code placement.
2006 Common Var(common_deferred_options) Defer
2009 Common Joined RejectNegative Var(common_deferred_options) Defer
2010 -frandom-seed=<string> Make compile reproducible using <string>.
2012 ; This switch causes the command line that was used to create an
2013 ; object file to be recorded into the object file. The exact format
2014 ; of this recording is target and binary file format dependent.
2015 ; It is related to the -fverbose-asm switch, but that switch only
2016 ; records information in the assembler output file as comments, so
2017 ; they never reach the object file.
2018 frecord-gcc-switches
2019 Common Report Var(flag_record_gcc_switches)
2020 Record gcc command line switches in the object file.
2023 Common Report Var(flag_pcc_struct_return,0) Optimization
2024 Return small aggregates in registers.
2028 Does nothing. Preserved for backward compatibility.
2031 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2032 Tell DSE that the storage for a C++ object is dead when the constructor
2033 starts and when the destructor finishes.
2036 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization
2038 flive-range-shrinkage
2039 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2040 Relief of register pressure through live range shrinkage.
2043 Common Report Var(flag_rename_registers) Init(2) Optimization
2044 Perform a register renaming optimization pass.
2047 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2048 Perform a target dependent instruction fusion optimization pass.
2051 Common Report Var(flag_reorder_blocks) Optimization
2052 Reorder basic blocks to improve code placement.
2054 freorder-blocks-algorithm=
2055 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2056 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2059 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2062 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2065 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2067 freorder-blocks-and-partition
2068 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2069 Reorder basic blocks and partition into hot and cold sections.
2072 Common Report Var(flag_reorder_functions) Optimization
2073 Reorder functions to improve code placement.
2075 frerun-cse-after-loop
2076 Common Report Var(flag_rerun_cse_after_loop) Optimization
2077 Add a common subexpression elimination pass after loop optimizations.
2081 Does nothing. Preserved for backward compatibility.
2084 Common Report Var(flag_rounding_math) Optimization SetByCombined
2085 Disable optimizations that assume default FP rounding behavior.
2088 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2089 Enable scheduling across basic blocks.
2092 Common Report Var(flag_sched_pressure) Init(0) Optimization
2093 Enable register pressure sensitive insn scheduling.
2096 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2097 Allow speculative motion of non-loads.
2100 Common Report Var(flag_schedule_speculative_load) Optimization
2101 Allow speculative motion of some loads.
2103 fsched-spec-load-dangerous
2104 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2105 Allow speculative motion of more loads.
2108 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2109 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2111 fsched2-use-superblocks
2112 Common Report Var(flag_sched2_use_superblocks) Optimization
2113 If scheduling post reload, do superblock scheduling.
2117 Does nothing. Preserved for backward compatibility.
2120 Common Report Var(flag_schedule_insns) Optimization
2121 Reschedule instructions before register allocation.
2124 Common Report Var(flag_schedule_insns_after_reload) Optimization
2125 Reschedule instructions after register allocation.
2127 ; This flag should be on when a target implements non-trivial
2128 ; scheduling hooks, maybe saving some information for its own sake.
2129 ; On IA64, for example, this is used for correct bundling.
2130 fselective-scheduling
2131 Common Report Var(flag_selective_scheduling) Optimization
2132 Schedule instructions using selective scheduling algorithm.
2134 fselective-scheduling2
2135 Common Report Var(flag_selective_scheduling2) Optimization
2136 Run selective scheduling after reload.
2139 Common Undocumented Var(flag_self_test)
2142 fsel-sched-pipelining
2143 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2144 Perform software pipelining of inner loops during selective scheduling.
2146 fsel-sched-pipelining-outer-loops
2147 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2148 Perform software pipelining of outer loops during selective scheduling.
2150 fsel-sched-reschedule-pipelined
2151 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2152 Reschedule pipelined regions without pipelining.
2154 fsemantic-interposition
2155 Common Report Var(flag_semantic_interposition) Init(1)
2156 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2158 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2159 ; of stalled insns into the ready list.
2160 fsched-stalled-insns
2161 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2162 Allow premature scheduling of queued insns.
2164 fsched-stalled-insns=
2165 Common RejectNegative Joined UInteger Optimization
2166 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2168 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2169 ; be examined for a dependency on a stalled insn that is candidate for
2170 ; premature removal from the queue of stalled insns into the ready list (has
2171 ; an effect only if the flag 'sched_stalled_insns' is set).
2172 fsched-stalled-insns-dep
2173 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2174 Set dependence distance checking in premature scheduling of queued insns.
2176 fsched-stalled-insns-dep=
2177 Common RejectNegative Joined UInteger Optimization
2178 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2180 fsched-group-heuristic
2181 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2182 Enable the group heuristic in the scheduler.
2184 fsched-critical-path-heuristic
2185 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2186 Enable the critical path heuristic in the scheduler.
2188 fsched-spec-insn-heuristic
2189 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2190 Enable the speculative instruction heuristic in the scheduler.
2192 fsched-rank-heuristic
2193 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2194 Enable the rank heuristic in the scheduler.
2196 fsched-last-insn-heuristic
2197 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2198 Enable the last instruction heuristic in the scheduler.
2200 fsched-dep-count-heuristic
2201 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2202 Enable the dependent count heuristic in the scheduler.
2205 Common Report Var(flag_section_anchors) Optimization
2206 Access data in the same section from shared anchor points.
2210 Does nothing. Preserved for backward compatibility.
2214 Does nothing. Preserved for backward compatibility.
2217 Common Report Var(flag_ree) Init(0)
2218 Turn on Redundant Extensions Elimination pass.
2221 Common Report Var(flag_show_column) Init(1)
2222 Show column numbers in diagnostics, when available. Default on.
2225 Common Report Var(flag_shrink_wrap) Optimization
2226 Emit function prologues only before parts of the function that need it,
2227 rather than at the top of the function.
2229 fshrink-wrap-separate
2230 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2231 Shrink-wrap parts of the prologue and epilogue separately.
2234 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2235 Disable optimizations observable by IEEE signaling NaNs.
2238 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2239 Disable floating point optimizations that ignore the IEEE signedness of zero.
2241 fsingle-precision-constant
2242 Common Report Var(flag_single_precision_constant) Optimization
2243 Convert floating point constants to single precision constants.
2245 fsplit-ivs-in-unroller
2246 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2247 Split lifetimes of induction variables when loops are unrolled.
2250 Common Report Var(flag_split_stack) Init(-1)
2251 Generate discontiguous stack frames.
2254 Common Report Var(flag_split_wide_types) Optimization
2255 Split wide types into independent registers.
2258 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2259 Enable backward propagation of use properties at the SSA level.
2262 Common Report Var(flag_ssa_phiopt) Optimization
2263 Optimize conditional patterns using SSA PHI nodes.
2266 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2267 Optimize amount of stdarg registers saved to stack at start of function.
2269 fvariable-expansion-in-unroller
2270 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2271 Apply variable expansion when loops are unrolled.
2274 Common Report RejectNegative Joined
2275 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2278 Common Alias(fstack-check=, specific, no)
2279 Insert stack checking code into the program. Same as -fstack-check=specific.
2282 Common Var(common_deferred_options) Defer
2284 fstack-limit-register=
2285 Common RejectNegative Joined Var(common_deferred_options) Defer
2286 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2288 fstack-limit-symbol=
2289 Common RejectNegative Joined Var(common_deferred_options) Defer
2290 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2293 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2294 Use propolice as a stack protection method.
2296 fstack-protector-all
2297 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2298 Use a stack protection method for every function.
2300 fstack-protector-strong
2301 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2302 Use a smart stack protection method for certain functions.
2304 fstack-protector-explicit
2305 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2306 Use stack protection method only for functions with the stack_protect attribute.
2309 Common RejectNegative Var(flag_stack_usage)
2310 Output stack usage information on a per-function basis.
2314 Does nothing. Preserved for backward compatibility.
2316 ; Nonzero if we should do (language-dependent) alias analysis.
2317 ; Typically, this analysis will assume that expressions of certain
2318 ; types do not alias expressions of certain other types. Only used
2319 ; if alias analysis (in general) is enabled.
2321 Common Report Var(flag_strict_aliasing) Optimization
2322 Assume strict aliasing rules apply.
2325 Common Report Var(flag_strict_overflow) Optimization
2326 Treat signed overflow as undefined.
2329 Common Report Var(flag_sync_libcalls) Init(1)
2330 Implement __atomic operations via libcalls to legacy __sync functions.
2333 Common Report Var(flag_syntax_only)
2334 Check for syntax errors, then stop.
2337 Common Report Var(flag_test_coverage)
2338 Create data files needed by \"gcov\".
2341 Common Report Var(flag_thread_jumps) Optimization
2342 Perform jump threading optimizations.
2345 Common Report Var(time_report)
2346 Report the time taken by each compiler pass.
2348 ftime-report-details
2349 Common Report Var(time_report_details)
2350 Record times taken by sub-phases separately.
2353 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2354 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2357 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2360 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2363 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2366 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2369 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2372 Common Report Var(flag_toplevel_reorder) Init(2)
2373 Reorder top level functions, variables, and asms.
2376 Common Report Var(flag_tracer) Optimization
2377 Perform superblock formation via tail duplication.
2380 Common Report Var(flag_trampolines) Init(0)
2381 For targets that normally need trampolines for nested functions, always
2382 generate them instead of using descriptors.
2384 ; Zero means that floating-point math operations cannot generate a
2385 ; (user-visible) trap. This is the case, for example, in nonstop
2386 ; IEEE 754 arithmetic.
2388 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2389 Assume floating-point operations can trap.
2392 Common Report Var(flag_trapv) Optimization
2393 Trap for signed overflow in addition, subtraction and multiplication.
2396 Common Report Var(flag_tree_ccp) Optimization
2397 Enable SSA-CCP optimization on trees.
2400 Common Report Var(flag_tree_bit_ccp) Optimization
2401 Enable SSA-BIT-CCP optimization on trees.
2405 Does nothing. Preserved for backward compatibility.
2408 Common Report Var(flag_tree_ch) Optimization
2409 Enable loop header copying on trees.
2411 ftree-coalesce-inlined-vars
2412 Common Ignore RejectNegative
2413 Does nothing. Preserved for backward compatibility.
2416 Common Report Var(flag_tree_coalesce_vars) Optimization
2417 Enable SSA coalescing of user variables.
2421 Does nothing. Preserved for backward compatibility.
2424 Common Report Var(flag_tree_copy_prop) Optimization
2425 Enable copy propagation on trees.
2427 ftree-store-copy-prop
2429 Does nothing. Preserved for backward compatibility.
2432 Common Report Var(flag_tree_cselim) Init(2) Optimization
2433 Transform condition stores into unconditional ones.
2435 ftree-switch-conversion
2436 Common Report Var(flag_tree_switch_conversion) Optimization
2437 Perform conversions of switch initializations.
2440 Common Report Var(flag_tree_dce) Optimization
2441 Enable SSA dead code elimination optimization on trees.
2443 ftree-dominator-opts
2444 Common Report Var(flag_tree_dom) Optimization
2445 Enable dominator optimizations.
2448 Common Report Var(flag_tree_tail_merge) Optimization
2449 Enable tail merging on trees.
2452 Common Report Var(flag_tree_dse) Optimization
2453 Enable dead store elimination.
2456 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2457 Enable forward propagation on trees.
2460 Common Report Var(flag_tree_fre) Optimization
2461 Enable Full Redundancy Elimination (FRE) on trees.
2464 Common Report Var(flag_optimize_strlen) Optimization
2465 Enable string length optimizations on trees.
2467 fisolate-erroneous-paths-dereference
2468 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2469 Detect paths that trigger erroneous or undefined behavior due to
2470 dereferencing a null pointer. Isolate those paths from the main control
2471 flow and turn the statement with erroneous or undefined behavior into a trap.
2473 fisolate-erroneous-paths-attribute
2474 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2475 Detect paths that trigger erroneous or undefined behavior due a null value
2476 being used in a way forbidden by a returns_nonnull or nonnull
2477 attribute. Isolate those paths from the main control flow and turn the
2478 statement with erroneous or undefined behavior into a trap.
2480 ftree-loop-distribution
2481 Common Report Var(flag_tree_loop_distribution) Optimization
2482 Enable loop distribution on trees.
2484 ftree-loop-distribute-patterns
2485 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2486 Enable loop distribution for patterns transformed into a library call.
2489 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2490 Enable loop invariant motion on trees.
2493 Common Alias(floop-nest-optimize)
2494 Enable loop nest transforms. Same as -floop-nest-optimize.
2497 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2498 Create canonical induction variables in loops.
2501 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2502 Enable loop optimizations on tree level.
2504 ftree-parallelize-loops=
2505 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2506 Enable automatic parallelization of loops.
2509 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2510 Enable hoisting loads from conditional pointers.
2513 Common Report Var(flag_tree_pre) Optimization
2514 Enable SSA-PRE optimization on trees.
2517 Common Report Var(flag_tree_partial_pre) Optimization
2518 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2521 Common Report Var(flag_tree_pta) Optimization
2522 Perform function-local points-to analysis on trees.
2525 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2526 Enable reassociation on tree level.
2530 Does nothing. Preserved for backward compatibility.
2533 Common Report Var(flag_tree_sink) Optimization
2534 Enable SSA code sinking on trees.
2537 Common Report Var(flag_tree_slsr) Optimization
2538 Perform straight-line strength reduction.
2541 Common Report Var(flag_tree_sra) Optimization
2542 Perform scalar replacement of aggregates.
2545 Common Report Var(flag_tree_ter) Optimization
2546 Replace temporary expressions in the SSA->normal pass.
2549 Common Report Var(flag_tree_live_range_split) Optimization
2550 Perform live range splitting during the SSA->normal pass.
2553 Common Report Var(flag_tree_vrp) Init(0) Optimization
2554 Perform Value Range Propagation on trees.
2557 Common Report Var(flag_split_paths) Init(0) Optimization
2558 Split paths leading to loop backedges.
2560 funconstrained-commons
2561 Common Var(flag_unconstrained_commons) Optimization
2562 Assume common declarations may be overridden with ones with a larger
2566 Common Report Var(flag_unit_at_a_time) Init(1)
2567 Compile whole compilation unit at a time.
2570 Common Report Var(flag_unroll_loops) Optimization
2571 Perform loop unrolling when iteration count is known.
2574 Common Report Var(flag_unroll_all_loops) Optimization
2575 Perform loop unrolling for all loops.
2577 ; Nonzero means that loop optimizer may assume that the induction variables
2578 ; that control loops do not overflow and that the loops with nontrivial
2579 ; exit condition are not infinite
2580 funsafe-loop-optimizations
2582 Does nothing. Preserved for backward compatibility.
2585 Common Report Var(flag_associative_math) SetByCombined Optimization
2586 Allow optimization for floating-point arithmetic which may change the
2587 result of the operation due to rounding.
2590 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2591 Same as -fassociative-math for expressions which include division.
2593 ; Nonzero means that unsafe floating-point math optimizations are allowed
2594 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2595 ; are allowed to assume that their arguments and results are "normal"
2596 ; (e.g., nonnegative for SQRT).
2597 funsafe-math-optimizations
2598 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2599 Allow math optimizations that may violate IEEE or ISO standards.
2602 Common Report Var(flag_unswitch_loops) Optimization
2603 Perform loop unswitching.
2606 Common Report Var(flag_split_loops) Optimization
2607 Perform loop splitting.
2610 Common Report Var(flag_unwind_tables) Optimization
2611 Just generate unwind tables for exception handling.
2614 Common Driver Negative(fuse-ld=gold)
2615 Use the bfd linker instead of the default linker.
2618 Common Driver Negative(fuse-ld=bfd)
2619 Use the gold linker instead of the default linker.
2622 Common Undocumented Var(flag_use_linker_plugin)
2624 ; Positive if we should track variables, negative if we should run
2625 ; the var-tracking pass only to discard debug annotations, zero if
2626 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2627 ; will be set according to optimize, debug_info_level and debug_hooks
2628 ; in process_options ().
2630 Common Report Var(flag_var_tracking) Init(2) Optimization
2631 Perform variable tracking.
2633 ; Positive if we should track variables at assignments, negative if
2634 ; we should run the var-tracking pass only to discard debug
2635 ; annotations. When flag_var_tracking_assignments ==
2636 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2637 fvar-tracking-assignments
2638 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2639 Perform variable tracking by annotating assignments.
2641 ; Nonzero if we should toggle flag_var_tracking_assignments after
2642 ; processing options and computing its default. */
2643 fvar-tracking-assignments-toggle
2644 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2645 Toggle -fvar-tracking-assignments.
2647 ; Positive if we should track uninitialized variables, negative if
2648 ; we should run the var-tracking pass only to discard debug
2649 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2650 ; will be set according to flag_var_tracking.
2651 fvar-tracking-uninit
2652 Common Report Var(flag_var_tracking_uninit) Optimization
2653 Perform variable tracking and also tag variables that are uninitialized.
2656 Common Report Var(flag_tree_vectorize) Optimization
2657 Enable vectorization on trees.
2659 ftree-vectorizer-verbose=
2660 Common Joined RejectNegative Ignore
2661 Does nothing. Preserved for backward compatibility.
2663 ftree-loop-vectorize
2664 Common Report Var(flag_tree_loop_vectorize) Optimization
2665 Enable loop vectorization on trees.
2668 Common Report Var(flag_tree_slp_vectorize) Optimization
2669 Enable basic block vectorization (SLP) on trees.
2672 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2673 Specifies the cost model for vectorization.
2676 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2677 Specifies the vectorization cost model for code marked with a simd directive.
2680 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2683 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2686 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2689 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2692 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2693 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2696 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2697 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2699 ftree-vect-loop-version
2701 Does nothing. Preserved for backward compatibility.
2704 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2705 Enable copy propagation of scalar-evolution information.
2707 ; -fverbose-asm causes extra commentary information to be produced in
2708 ; the generated assembly code (to make it more readable). This option
2709 ; is generally only of use to those who actually need to read the
2710 ; generated assembly code (perhaps while debugging the compiler itself).
2711 ; -fno-verbose-asm, the default, causes the extra information
2712 ; to not be added and is useful when comparing two assembler files.
2714 Common Report Var(flag_verbose_asm)
2715 Add extra commentary to assembler output.
2718 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2719 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2722 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2725 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2728 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2731 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2734 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2737 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2738 Validate vtable pointers before using them.
2741 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2744 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2747 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2750 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2753 Common Var(flag_vtv_counts)
2754 Output vtable verification counters.
2757 Common Var(flag_vtv_debug)
2758 Output vtable verification pointer sets information.
2761 Common Report Var(flag_value_profile_transformations) Optimization
2762 Use expression value profiles in optimizations.
2765 Common Report Var(flag_web) Init(2) Optimization
2766 Construct webs and split unrelated uses of single variable.
2768 ftree-builtin-call-dce
2769 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2770 Enable conditional dead code elimination for builtin calls.
2773 Common Report Var(flag_whole_program) Init(0)
2774 Perform whole program optimizations.
2777 Common Report Var(flag_wrapv) Optimization
2778 Assume signed arithmetic overflow wraps around.
2780 fzero-initialized-in-bss
2781 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2782 Put zero initialized data in the bss section.
2785 Common JoinedOrMissing
2786 Generate debug information in default format.
2789 Common JoinedOrMissing Negative(gdwarf)
2790 Generate debug information in COFF format.
2793 Common JoinedOrMissing Negative(gdwarf-)
2794 Generate debug information in default version of DWARF format.
2797 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2798 Generate debug information in DWARF v2 (or later) format.
2801 Common JoinedOrMissing
2802 Generate debug information in default extended format.
2805 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2806 Don't generate DWARF pubnames and pubtypes sections.
2809 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2810 Generate DWARF pubnames and pubtypes sections.
2813 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2814 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2816 gno-record-gcc-switches
2817 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2818 Don't record gcc command line switches in DWARF DW_AT_producer.
2820 grecord-gcc-switches
2821 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2822 Record gcc command line switches in DWARF DW_AT_producer.
2825 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2826 Don't generate debug information in separate .dwo files.
2829 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2830 Generate debug information in separate .dwo files.
2833 Common JoinedOrMissing Negative(gstabs+)
2834 Generate debug information in STABS format.
2837 Common JoinedOrMissing Negative(gvms)
2838 Generate debug information in extended STABS format.
2841 Common RejectNegative Var(dwarf_strict,0) Init(0)
2842 Emit DWARF additions beyond selected version.
2845 Common Report RejectNegative Var(dwarf_strict,1)
2846 Don't emit DWARF additions beyond selected version.
2849 Common Report Var(flag_gtoggle)
2850 Toggle debug information generation.
2853 Common JoinedOrMissing Negative(gxcoff)
2854 Generate debug information in VMS format.
2857 Common JoinedOrMissing Negative(gxcoff+)
2858 Generate debug information in XCOFF format.
2861 Common JoinedOrMissing Negative(gcoff)
2862 Generate debug information in extended XCOFF format.
2865 Name(compressed_debug_sections) Type(int)
2867 ; Since -gz= is completely handled in specs, the values aren't used and we
2868 ; assign arbitrary constants.
2870 Enum(compressed_debug_sections) String(none) Value(0)
2873 Enum(compressed_debug_sections) String(zlib) Value(1)
2876 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2880 Generate compressed debug sections.
2883 Common Driver Joined Enum(compressed_debug_sections)
2884 -gz=<format> Generate compressed debug sections in format <format>.
2887 Driver Joined Separate
2890 Common Joined Var(plugindir_string) Init(0)
2891 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2894 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2895 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2898 Driver Joined Separate
2903 no-canonical-prefixes
2916 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2917 -o <file> Place output into <file>.
2920 Common Var(profile_flag)
2921 Enable function profiling.
2924 Driver Var(pass_exit_codes)
2927 Common Alias(Wpedantic)
2930 Common Var(flag_pedantic_errors)
2931 Like -pedantic but issue them as errors.
2937 Driver Var(use_pipes)
2940 Driver JoinedOrMissing Var(print_file_name)
2942 print-libgcc-file-name
2945 print-multi-directory
2946 Driver Var(print_multi_directory)
2949 Driver Var(print_multi_lib)
2951 print-multi-os-directory
2952 Driver Var(print_multi_os_directory)
2955 Driver Var(print_multiarch)
2958 Driver JoinedOrMissing Var(print_prog_name)
2961 Driver Var(print_search_dirs)
2964 Driver Var(print_sysroot)
2966 print-sysroot-headers-suffix
2967 Driver Var(print_sysroot_headers_suffix)
2970 Common Var(quiet_flag) RejectDriver
2971 Do not display functions compiled or elapsed time.
2989 Driver Var(report_times)
2992 Driver JoinedOrMissing
2995 Driver Joined Separate
2999 ; C option, but driver must not handle as "-u ndef".
3002 Common Driver Var(verbose_flag)
3003 Enable verbose output.
3006 Common Var(version_flag) RejectDriver
3007 Display the compiler's version.
3010 Common Var(inhibit_warnings)
3014 Driver Separate Var(wrapper_string)
3017 Driver Joined Separate
3020 Driver RejectNegative Negative(pie)
3021 Create a shared library.
3027 Driver Separate Alias(specs=)
3040 ; Documented for Fortran, but always accepted by driver.
3047 ; Documented for Go, but always accepted by driver.
3065 Driver RejectNegative Negative(shared)
3066 Don't create a position independent executable.
3069 Driver RejectNegative Negative(no-pie)
3070 Create a position independent executable.
3073 Driver Joined Separate
3076 Common Report Var(flag_ipa_ra) Optimization
3077 Use caller save register across calls if possible.
3079 ; This comment is to ensure we retain the blank line above.