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)
927 flimit-function-alignment
928 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
931 Common Report Var(align_jumps,0) Optimization UInteger
932 Align labels which are only reached by jumping.
935 Common RejectNegative Joined UInteger Var(align_jumps)
938 Common Report Var(align_labels,0) Optimization UInteger
942 Common RejectNegative Joined UInteger Var(align_labels)
945 Common Report Var(align_loops,0) Optimization UInteger
946 Align the start of loops.
949 Common RejectNegative Joined UInteger Var(align_loops)
953 Does nothing. Preserved for backward compatibility.
957 Does nothing. Preserved for backward compatibility.
959 fargument-noalias-global
961 Does nothing. Preserved for backward compatibility.
963 fargument-noalias-anything
965 Does nothing. Preserved for backward compatibility.
968 Common Driver Report Joined
969 Select what to sanitize.
972 Common Joined RejectNegative Var(common_deferred_options) Defer
973 -fasan-shadow-offset=<number> Use custom shadow memory offset.
976 Common Joined RejectNegative Var(common_deferred_options) Defer
977 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
978 in user-defined sections.
982 After diagnosing undefined behavior attempt to continue execution.
986 This switch is deprecated; use -fsanitize-recover= instead.
988 fsanitize-address-use-after-scope
989 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
991 fsanitize-undefined-trap-on-error
992 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
993 Use trap instead of a library function for undefined behavior sanitization.
995 fasynchronous-unwind-tables
996 Common Report Var(flag_asynchronous_unwind_tables) Optimization
997 Generate unwind tables that are exact at each instruction boundary.
1000 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1001 Generate auto-inc/dec instructions.
1004 Common Report Var(flag_auto_profile)
1005 Use sample profile information for call graph node weights. The default
1006 profile file is fbdata.afdo in 'pwd'.
1009 Common Joined RejectNegative Var(auto_profile_file)
1010 Use sample profile information for call graph node weights. The profile
1011 file is specified in the argument.
1013 ; -fcheck-bounds causes gcc to generate array bounds checks.
1014 ; For C, C++ and ObjC: defaults off.
1015 ; For Java: defaults to on.
1016 ; For Fortran: defaults to off.
1018 Common Report Var(flag_bounds_check)
1019 Generate code to check bounds before indexing arrays.
1022 Common Report Var(flag_branch_on_count_reg) Optimization
1023 Replace add, compare, branch with branch on count register.
1025 fbranch-probabilities
1026 Common Report Var(flag_branch_probabilities) Optimization
1027 Use profiling information for branch probabilities.
1029 fbranch-target-load-optimize
1030 Common Report Var(flag_branch_target_load_optimize) Optimization
1031 Perform branch target load optimization before prologue / epilogue threading.
1033 fbranch-target-load-optimize2
1034 Common Report Var(flag_branch_target_load_optimize2) Optimization
1035 Perform branch target load optimization after prologue / epilogue threading.
1038 Common Report Var(flag_btr_bb_exclusive) Optimization
1039 Restrict target load migration not to re-use registers in any basic block.
1042 Common Joined RejectNegative Var(common_deferred_options) Defer
1043 -fcall-saved-<register> Mark <register> as being preserved across functions.
1046 Common Joined RejectNegative Var(common_deferred_options) Defer
1047 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1049 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1050 ; be saved across function calls, if that produces overall better code.
1051 ; Optional now, so people can test it.
1053 Common Report Var(flag_caller_saves) Optimization
1054 Save registers around function calls.
1057 Common Report Var(flag_check_data_deps)
1058 This switch is deprecated; do not use.
1061 Common Var(flag_check_new)
1062 Check the return value of new in C++.
1065 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1066 Perform internal consistency checkings.
1069 Common Joined RejectNegative UInteger Var(flag_checking)
1070 Perform internal consistency checkings.
1073 Common Report Var(flag_code_hoisting) Optimization
1074 Enable code hoisting.
1076 fcombine-stack-adjustments
1077 Common Report Var(flag_combine_stack_adjustments) Optimization
1078 Looks for opportunities to reduce stack adjustments and stack references.
1081 Common Report Var(flag_no_common,0)
1082 Do not put uninitialized globals in the common section.
1086 ; Converted by the driver to -fcompare-debug= options.
1089 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1090 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1092 fcompare-debug-second
1093 Common Driver RejectNegative Var(flag_compare_debug)
1094 Run only the second compilation of -fcompare-debug.
1097 Common Report Var(flag_compare_elim_after_reload) Optimization
1098 Perform comparison elimination after register allocation has finished.
1101 Common Var(flag_conserve_stack) Optimization
1102 Do not perform optimizations increasing noticeably stack usage.
1105 Common Report Var(flag_cprop_registers) Optimization
1106 Perform a register copy-propagation optimization pass.
1109 Common Report Var(flag_crossjumping) Optimization
1110 Perform cross-jumping optimization.
1113 Common Report Var(flag_cse_follow_jumps) Optimization
1114 When running CSE, follow jumps to their targets.
1118 Does nothing. Preserved for backward compatibility.
1121 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1122 Omit range reduction step when performing complex division.
1125 Common Report Var(flag_cx_fortran_rules) Optimization
1126 Complex multiplication and division follow Fortran rules.
1129 Common Report Var(flag_data_sections)
1130 Place data items into their own section.
1133 Common Report Var(common_deferred_options) Defer
1134 List all available debugging counters with their limits and counts.
1137 Common RejectNegative Joined Var(common_deferred_options) Defer
1138 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1141 Common Joined RejectNegative Var(common_deferred_options) Defer
1142 Map one directory name to another in debug information.
1144 fdebug-types-section
1145 Common Report Var(flag_debug_types_section) Init(0)
1146 Output .debug_types section when using DWARF v4 debuginfo.
1148 ; Nonzero for -fdefer-pop: don't pop args after each function call
1149 ; instead save them up to pop many calls' args with one insns.
1151 Common Report Var(flag_defer_pop) Optimization
1152 Defer popping functions args from stack until later.
1155 Common Report Var(flag_delayed_branch) Optimization
1156 Attempt to fill delay slots of branch instructions.
1158 fdelete-dead-exceptions
1159 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1160 Delete dead instructions that may throw exceptions.
1162 fdelete-null-pointer-checks
1163 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1164 Delete useless null pointer checks.
1166 fdevirtualize-at-ltrans
1167 Common Report Var(flag_ltrans_devirtualize)
1168 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1170 fdevirtualize-speculatively
1171 Common Report Var(flag_devirtualize_speculatively) Optimization
1172 Perform speculative devirtualization.
1175 Common Report Var(flag_devirtualize) Optimization
1176 Try to convert virtual calls to direct ones.
1178 fdiagnostics-show-location=
1179 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1180 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1182 ; Required for these enum values.
1187 Name(diagnostic_prefixing_rule) Type(int)
1190 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1193 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1195 fdiagnostics-show-caret
1196 Common Var(flag_diagnostics_show_caret) Init(1)
1197 Show the source line with a caret indicating the column.
1200 Common Alias(fdiagnostics-color=,always,never)
1204 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1205 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1207 ; Required for these enum values.
1212 Name(diagnostic_color_rule) Type(int)
1215 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1218 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1221 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1223 fdiagnostics-parseable-fixits
1224 Common Var(flag_diagnostics_parseable_fixits)
1225 Print fixit hints in machine-readable form.
1227 fdiagnostics-generate-patch
1228 Common Var(flag_diagnostics_generate_patch)
1229 Print fix-it hints to stderr in unified diff format.
1231 fdiagnostics-show-option
1232 Common Var(flag_diagnostics_show_option) Init(1)
1233 Amend appropriate diagnostic messages with the command line option that controls them.
1236 Common Joined RejectNegative Var(common_deferred_options) Defer
1237 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1240 Common Joined RejectNegative Var(common_deferred_options) Defer
1241 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1244 Common Joined RejectNegative Var(common_deferred_options) Defer
1245 -fdump-<type> Dump various compiler internals to a file.
1248 Driver RejectNegative
1251 Common RejectNegative Joined Var(flag_dump_final_insns)
1252 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1255 Common RejectNegative Joined Var(flag_dump_go_spec)
1256 -fdump-go-spec=filename Write all declarations to file as Go code.
1259 Common Report Var(flag_dump_noaddr)
1260 Suppress output of addresses in debugging dumps.
1263 Common Driver Var(flag_report_bug)
1264 Collect and dump debug information into temporary file if ICE in C/C++
1267 fdump-internal-locations
1268 Common Var(flag_dump_locations) Init(0)
1269 Dump detailed information on GCC's internal representation of source code locations.
1272 Common Var(flag_dump_passes) Init(0)
1273 Dump optimization passes.
1276 Common Report Var(flag_dump_unnumbered)
1277 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1279 fdump-unnumbered-links
1280 Common Report Var(flag_dump_unnumbered_links)
1281 Suppress output of previous and next insn numbers in debugging dumps.
1284 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1285 Enable CFI tables via GAS assembler directives.
1288 Common Report Var(flag_early_inlining) Init(1) Optimization
1289 Perform early inlining.
1291 feliminate-dwarf2-dups
1292 Common Report Var(flag_eliminate_dwarf2_dups)
1293 Perform DWARF duplicate elimination.
1296 Common Report Var(flag_ipa_sra) Init(0) Optimization
1297 Perform interprocedural reduction of aggregates.
1299 feliminate-unused-debug-symbols
1300 Common Report Var(flag_debug_only_used_symbols)
1301 Perform unused symbol elimination in debug info.
1303 feliminate-unused-debug-types
1304 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1305 Perform unused type elimination in debug info.
1307 femit-class-debug-always
1308 Common Report Var(flag_emit_class_debug_always) Init(0)
1309 Do not suppress C++ class debug information.
1312 Common Report Var(flag_exceptions) Optimization
1313 Enable exception handling.
1315 fexpensive-optimizations
1316 Common Report Var(flag_expensive_optimizations) Optimization
1317 Perform a number of minor, expensive optimizations.
1320 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1321 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1324 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1327 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1330 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1332 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1333 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1334 fpermitted-flt-eval-methods=
1335 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1336 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1339 Name(permitted_flt_eval_methods) Type(enum permitted_flt_eval_methods) UnknownError(unknown specification for the set of FLT_EVAL_METHOD values to permit %qs)
1342 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1345 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1351 Common Var(flag_fat_lto_objects)
1352 Output lto objects containing both the intermediate language and binary output.
1355 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1356 Assume no NaNs or infinities are generated.
1359 Common Joined RejectNegative Var(common_deferred_options) Defer
1360 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1363 Common Report Var(flag_float_store) Optimization
1364 Don't allocate floats and doubles in extended-precision registers.
1368 Does nothing. Preserved for backward compatibility.
1371 Common Report Var(flag_forward_propagate) Optimization
1372 Perform a forward propagation pass on RTL.
1375 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1376 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1379 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1382 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1384 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1386 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1389 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1391 ffp-int-builtin-inexact
1392 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1393 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1395 ; Nonzero means don't put addresses of constant functions in registers.
1396 ; Used for compiling the Unix kernel, where strange substitutions are
1397 ; done on the assembly output.
1399 Common Report Var(flag_no_function_cse,0) Optimization
1400 Allow function addresses to be held in registers.
1403 Common Report Var(flag_function_sections)
1404 Place each function into its own section.
1407 Common Report Var(flag_gcse) Optimization
1408 Perform global common subexpression elimination.
1411 Common Report Var(flag_gcse_lm) Init(1) Optimization
1412 Perform enhanced load motion during global common subexpression elimination.
1415 Common Report Var(flag_gcse_sm) Init(0) Optimization
1416 Perform store motion after global common subexpression elimination.
1419 Common Report Var(flag_gcse_las) Init(0) Optimization
1420 Perform redundant load after store elimination in global common subexpression
1424 Common Report Var(flag_gcse_after_reload) Optimization
1425 Perform global common subexpression elimination after register allocation has
1429 Name(dwarf_gnat_encodings) Type(int)
1432 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1435 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1438 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1441 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1442 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1444 ; This option is not documented yet as its semantics will change.
1446 Common Report Var(flag_graphite) Optimization
1447 Enable in and out of Graphite representation.
1450 Common Report Var(flag_graphite_identity) Optimization
1451 Enable Graphite Identity transformation.
1453 fhoist-adjacent-loads
1454 Common Report Var(flag_hoist_adjacent_loads) Optimization
1455 Enable hoisting adjacent loads to encourage generating conditional move
1459 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1460 ; Always keep a pointer to a live memory block
1462 floop-parallelize-all
1463 Common Report Var(flag_loop_parallelize_all) Optimization
1464 Mark all loops as parallel.
1467 Common Alias(floop-nest-optimize)
1468 Enable loop nest transforms. Same as -floop-nest-optimize.
1471 Common Alias(floop-nest-optimize)
1472 Enable loop nest transforms. Same as -floop-nest-optimize.
1475 Common Alias(floop-nest-optimize)
1476 Enable loop nest transforms. Same as -floop-nest-optimize.
1478 floop-unroll-and-jam
1479 Common Alias(floop-nest-optimize)
1480 Enable loop nest transforms. Same as -floop-nest-optimize.
1483 Common Report Var(flag_tm)
1484 Enable support for GNU transactional memory.
1487 Common Report Var(flag_gnu_unique) Init(1)
1488 Use STB_GNU_UNIQUE if supported by the assembler.
1492 Does nothing. Preserved for backward compatibility.
1495 Common Report Var(flag_loop_nest_optimize) Optimization
1496 Enable the loop nest optimizer.
1498 fstrict-volatile-bitfields
1499 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1500 Force bitfield accesses to match their type width.
1503 Common Report Var(flag_store_merging) Optimization
1504 Merge adjacent stores.
1506 fguess-branch-probability
1507 Common Report Var(flag_guess_branch_prob) Optimization
1508 Enable guessing of branch probabilities.
1510 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1511 ; Generate position-independent code for executables if possible
1512 ; On SVR4 targets, it also controls whether or not to emit a
1513 ; string identifying the compiler.
1515 Common Report Var(flag_no_ident,0)
1516 Process #ident directives.
1519 Common Report Var(flag_if_conversion) Optimization
1520 Perform conversion of conditional jumps to branchless equivalents.
1523 Common Report Var(flag_if_conversion2) Optimization
1524 Perform conversion of conditional jumps to conditional execution.
1527 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1528 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1531 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1534 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1537 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1540 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1542 ftree-loop-if-convert
1543 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1544 Convert conditional jumps in innermost loops to branchless equivalents.
1546 ftree-loop-if-convert-stores
1548 Does nothing. Preserved for backward compatibility.
1550 ; -finhibit-size-directive inhibits output of .size for ELF.
1551 ; This is used only for compiling crtstuff.c,
1552 ; and it may be extended to other effects
1553 ; needed for crtstuff.c on other systems.
1554 finhibit-size-directive
1555 Common Report Var(flag_inhibit_size_directive)
1556 Do not generate .size directives.
1559 Common Report Var(flag_indirect_inlining) Optimization
1560 Perform indirect inlining.
1562 ; General flag to enable inlining. Specifying -fno-inline will disable
1563 ; all inlining apart from always-inline functions.
1565 Common Report Var(flag_no_inline,0) Init(0) Optimization
1566 Enable inlining of function declared \"inline\", disabling disables all inlining.
1568 finline-small-functions
1569 Common Report Var(flag_inline_small_functions) Optimization
1570 Integrate functions into their callers when code size is known not to grow.
1573 Common Report Var(flag_inline_functions) Optimization
1574 Integrate functions not declared \"inline\" into their callers when profitable.
1576 finline-functions-called-once
1577 Common Report Var(flag_inline_functions_called_once) Optimization
1578 Integrate functions only required by their single caller.
1581 Common RejectNegative Joined Alias(finline-limit=)
1584 Common RejectNegative Joined UInteger
1585 -finline-limit=<number> Limit the size of inlined functions to <number>.
1588 Common Report Var(flag_inline_atomics) Init(1) Optimization
1589 Inline __atomic operations when a lock free instruction sequence is available.
1591 finstrument-functions
1592 Common Report Var(flag_instrument_function_entry_exit)
1593 Instrument function entry and exit with profiling calls.
1595 finstrument-functions-exclude-function-list=
1596 Common RejectNegative Joined
1597 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1599 finstrument-functions-exclude-file-list=
1600 Common RejectNegative Joined
1601 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1604 Common Report Var(flag_ipa_cp) Optimization
1605 Perform interprocedural constant propagation.
1608 Common Report Var(flag_ipa_cp_clone) Optimization
1609 Perform cloning to make Interprocedural constant propagation stronger.
1612 Common Report Var(flag_ipa_cp_alignment) Optimization
1613 Perform alignment discovery and propagation to make Interprocedural constant propagation stronger.
1616 Common Report Var(flag_ipa_bit_cp) Optimization
1617 Perform interprocedural bitwise constant propagation.
1620 Common Report Var(flag_ipa_profile) Init(0) Optimization
1621 Perform interprocedural profile propagation.
1624 Common Report Var(flag_ipa_pta) Init(0) Optimization
1625 Perform interprocedural points-to analysis.
1628 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1629 Discover pure and const functions.
1632 Common Report Var(flag_ipa_icf) Optimization
1633 Perform Identical Code Folding for functions and read-only variables.
1636 Common Report Var(flag_ipa_icf_functions) Optimization
1637 Perform Identical Code Folding for functions.
1640 Common Report Var(flag_ipa_icf_variables) Optimization
1641 Perform Identical Code Folding for variables.
1644 Common Report Var(flag_ipa_reference) Init(0) Optimization
1645 Discover readonly and non addressable static variables.
1649 Does nothing. Preserved for backward compatibility.
1653 Does nothing. Preserved for backward compatibility.
1656 Common Report Var(flag_ipa_vrp) Optimization
1657 Perform IPA Value Range Propagation.
1660 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1661 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1664 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1667 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1670 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1673 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1674 -fira-region=[one|all|mixed] Set regions for IRA.
1677 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1680 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1683 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1686 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1689 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1690 Use IRA based register pressure calculation
1691 in RTL hoist optimizations.
1694 Common Report Var(flag_ira_loop_pressure) Optimization
1695 Use IRA based register pressure calculation
1696 in RTL loop optimizations.
1698 fira-share-save-slots
1699 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1700 Share slots for saving different hard registers.
1702 fira-share-spill-slots
1703 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1704 Share stack slots for spilled pseudo-registers.
1707 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1708 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1711 Common Report Var(flag_ivopts) Init(1) Optimization
1712 Optimize induction variables on trees.
1715 Common Var(flag_jump_tables) Init(1) Optimization
1716 Use jump tables for sufficiently large switch statements.
1718 fkeep-inline-functions
1719 Common Report Var(flag_keep_inline_functions)
1720 Generate code for functions even if they are fully inlined.
1722 fkeep-static-functions
1723 Common Report Var(flag_keep_static_functions)
1724 Generate code for static functions even if they are never called.
1727 Common Report Var(flag_keep_static_consts) Init(1)
1728 Emit static const variables even if they are not used.
1731 Common Report Var(flag_leading_underscore) Init(-1)
1732 Give external symbols a leading underscore.
1736 Does nothing. Preserved for backward compatibility.
1739 Common Report Var(flag_lra_remat) Optimization
1740 Do CFG-sensitive rematerialization in LRA.
1744 Enable link-time optimization.
1747 Common RejectNegative Joined Var(flag_lto)
1748 Link-time optimization with number of parallel jobs or jobserver.
1751 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1754 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1757 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1760 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1763 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1766 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1769 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1770 Specify the algorithm to partition symbols and vars at linktime.
1772 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1773 flto-compression-level=
1774 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1775 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1777 flto-odr-type-merging
1778 Common Report Var(flag_lto_odr_type_mering) Init(1)
1779 Merge C++ types using One Definition Rule.
1782 Common Report Var(flag_lto_report) Init(0)
1783 Report various link-time optimization statistics.
1786 Common Report Var(flag_lto_report_wpa) Init(0)
1787 Report various link-time optimization statistics for WPA only.
1790 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1791 Set errno after built-in math functions.
1794 Common Joined RejectNegative UInteger Var(flag_max_errors)
1795 -fmax-errors=<number> Maximum number of errors to report.
1798 Common Report Var(mem_report)
1799 Report on permanent memory allocation.
1802 Common Report Var(mem_report_wpa)
1803 Report on permanent memory allocation in WPA only.
1805 ; This will attempt to merge constant section constants, if 1 only
1806 ; string constants and constants from constant pool, if 2 also constant
1808 fmerge-all-constants
1809 Common Report Var(flag_merge_constants,2) Init(1)
1810 Attempt to merge identical constants and constant variables.
1813 Common Report Var(flag_merge_constants,1)
1814 Attempt to merge identical constants across compilation units.
1816 fmerge-debug-strings
1817 Common Report Var(flag_merge_debug_strings) Init(1)
1818 Attempt to merge identical debug strings across compilation units.
1821 Common RejectNegative Joined UInteger
1822 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1825 Common Report Var(flag_modulo_sched) Optimization
1826 Perform SMS based modulo scheduling before the first scheduling pass.
1828 fmodulo-sched-allow-regmoves
1829 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1830 Perform SMS based modulo scheduling with register moves allowed.
1832 fmove-loop-invariants
1833 Common Report Var(flag_move_loop_invariants) Optimization
1834 Move loop invariant computations out of loops.
1837 Common Var(flag_dce) Init(1) Optimization
1838 Use the RTL dead code elimination pass.
1841 Common Var(flag_dse) Init(1) Optimization
1842 Use the RTL dead store elimination pass.
1844 freschedule-modulo-scheduled-loops
1845 Common Report Var(flag_resched_modulo_sched) Optimization
1846 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1848 fnon-call-exceptions
1849 Common Report Var(flag_non_call_exceptions) Optimization
1850 Support synchronous non-call exceptions.
1853 Common Driver Joined MissingArgError(options or targets missing after %qs)
1854 -foffload=<targets>=<options> Specify offloading targets and options for them.
1857 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1858 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1861 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1864 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1867 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1870 Common Report Var(flag_omit_frame_pointer) Optimization
1871 When possible do not generate stack frames.
1874 Common Report Var(flag_opt_info) Optimization
1875 Enable all optimization info dumps on stderr.
1878 Common Joined RejectNegative Var(common_deferred_options) Defer
1879 -fopt-info[-<type>=filename] Dump compiler optimization details.
1881 foptimize-register-move
1883 Does nothing. Preserved for backward compatibility.
1885 foptimize-sibling-calls
1886 Common Report Var(flag_optimize_sibling_calls) Optimization
1887 Optimize sibling and tail recursive calls.
1890 Common Report Var(flag_partial_inlining) Optimization
1891 Perform partial inlining.
1894 Common Report Var(pre_ipa_mem_report)
1895 Report on memory allocation before interprocedural optimization.
1897 fpost-ipa-mem-report
1898 Common Report Var(post_ipa_mem_report)
1899 Report on memory allocation before interprocedural optimization.
1902 Common Report Var(flag_pack_struct) Optimization
1903 Pack structure members together without holes.
1906 Common RejectNegative Joined UInteger Optimization
1907 -fpack-struct=<number> Set initial maximum structure member alignment.
1910 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1911 Return small aggregates in memory, not registers.
1914 Common Report Var(flag_peel_loops) Optimization
1915 Perform loop peeling.
1918 Common Report Var(flag_no_peephole,0) Optimization
1919 Enable machine specific peephole optimizations.
1922 Common Report Var(flag_peephole2) Optimization
1923 Enable an RTL peephole pass before sched2.
1926 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1927 Generate position-independent code if possible (large mode).
1930 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1931 Generate position-independent code for executables if possible (large mode).
1934 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1935 Generate position-independent code if possible (small mode).
1938 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1939 Generate position-independent code for executables if possible (small mode).
1942 Common Report Var(flag_plt) Init(1) Optimization
1943 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
1946 Common Joined RejectNegative Var(common_deferred_options) Defer
1947 Specify a plugin to load.
1950 Common Joined RejectNegative Var(common_deferred_options) Defer
1951 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
1953 fpredictive-commoning
1954 Common Report Var(flag_predictive_commoning) Optimization
1955 Run predictive commoning optimization.
1957 fprefetch-loop-arrays
1958 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1959 Generate prefetch instructions, if available, for arrays in loops.
1962 Common Report Var(profile_flag)
1963 Enable basic program profiling code.
1966 Common Report Var(profile_arc_flag)
1967 Insert arc-based program profiling code.
1970 Common Joined RejectNegative Var(profile_data_prefix)
1971 Set the top-level directory for storing the profile data.
1972 The default is 'pwd'.
1975 Common Report Var(flag_profile_correction)
1976 Enable correction of flow inconsistent profile data input.
1979 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
1980 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
1983 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
1986 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
1989 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
1992 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
1996 Enable common options for generating profile info for profile feedback directed optimizations.
1999 Common Joined RejectNegative
2000 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2003 Common Var(flag_profile_use)
2004 Enable common options for performing profile feedback directed optimizations.
2007 Common Joined RejectNegative
2008 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2011 Common Report Var(flag_profile_values)
2012 Insert code to profile values of expressions.
2015 Common Report Var(profile_report)
2016 Report on consistency of profile.
2018 fprofile-reorder-functions
2019 Common Report Var(flag_profile_reorder_functions)
2020 Enable function reordering that improves code placement.
2023 Common Var(common_deferred_options) Defer
2026 Common Joined RejectNegative Var(common_deferred_options) Defer
2027 -frandom-seed=<string> Make compile reproducible using <string>.
2029 ; This switch causes the command line that was used to create an
2030 ; object file to be recorded into the object file. The exact format
2031 ; of this recording is target and binary file format dependent.
2032 ; It is related to the -fverbose-asm switch, but that switch only
2033 ; records information in the assembler output file as comments, so
2034 ; they never reach the object file.
2035 frecord-gcc-switches
2036 Common Report Var(flag_record_gcc_switches)
2037 Record gcc command line switches in the object file.
2040 Common Report Var(flag_pcc_struct_return,0) Optimization
2041 Return small aggregates in registers.
2045 Does nothing. Preserved for backward compatibility.
2048 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2049 Tell DSE that the storage for a C++ object is dead when the constructor
2050 starts and when the destructor finishes.
2053 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization
2055 flive-range-shrinkage
2056 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2057 Relief of register pressure through live range shrinkage.
2060 Common Report Var(flag_rename_registers) Init(2) Optimization
2061 Perform a register renaming optimization pass.
2064 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2065 Perform a target dependent instruction fusion optimization pass.
2068 Common Report Var(flag_reorder_blocks) Optimization
2069 Reorder basic blocks to improve code placement.
2071 freorder-blocks-algorithm=
2072 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2073 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2076 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2079 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2082 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2084 freorder-blocks-and-partition
2085 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2086 Reorder basic blocks and partition into hot and cold sections.
2089 Common Report Var(flag_reorder_functions) Optimization
2090 Reorder functions to improve code placement.
2092 frerun-cse-after-loop
2093 Common Report Var(flag_rerun_cse_after_loop) Optimization
2094 Add a common subexpression elimination pass after loop optimizations.
2098 Does nothing. Preserved for backward compatibility.
2101 Common Report Var(flag_rounding_math) Optimization SetByCombined
2102 Disable optimizations that assume default FP rounding behavior.
2105 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2106 Enable scheduling across basic blocks.
2109 Common Report Var(flag_sched_pressure) Init(0) Optimization
2110 Enable register pressure sensitive insn scheduling.
2113 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2114 Allow speculative motion of non-loads.
2117 Common Report Var(flag_schedule_speculative_load) Optimization
2118 Allow speculative motion of some loads.
2120 fsched-spec-load-dangerous
2121 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2122 Allow speculative motion of more loads.
2125 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2126 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2128 fsched2-use-superblocks
2129 Common Report Var(flag_sched2_use_superblocks) Optimization
2130 If scheduling post reload, do superblock scheduling.
2134 Does nothing. Preserved for backward compatibility.
2137 Common Report Var(flag_schedule_insns) Optimization
2138 Reschedule instructions before register allocation.
2141 Common Report Var(flag_schedule_insns_after_reload) Optimization
2142 Reschedule instructions after register allocation.
2144 ; This flag should be on when a target implements non-trivial
2145 ; scheduling hooks, maybe saving some information for its own sake.
2146 ; On IA64, for example, this is used for correct bundling.
2147 fselective-scheduling
2148 Common Report Var(flag_selective_scheduling) Optimization
2149 Schedule instructions using selective scheduling algorithm.
2151 fselective-scheduling2
2152 Common Report Var(flag_selective_scheduling2) Optimization
2153 Run selective scheduling after reload.
2156 Common Undocumented Joined Var(flag_self_test)
2157 Run self-tests, using the given path to locate test files.
2159 fsel-sched-pipelining
2160 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2161 Perform software pipelining of inner loops during selective scheduling.
2163 fsel-sched-pipelining-outer-loops
2164 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2165 Perform software pipelining of outer loops during selective scheduling.
2167 fsel-sched-reschedule-pipelined
2168 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2169 Reschedule pipelined regions without pipelining.
2171 fsemantic-interposition
2172 Common Report Var(flag_semantic_interposition) Init(1)
2173 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2175 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2176 ; of stalled insns into the ready list.
2177 fsched-stalled-insns
2178 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2179 Allow premature scheduling of queued insns.
2181 fsched-stalled-insns=
2182 Common RejectNegative Joined UInteger Optimization
2183 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2185 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2186 ; be examined for a dependency on a stalled insn that is candidate for
2187 ; premature removal from the queue of stalled insns into the ready list (has
2188 ; an effect only if the flag 'sched_stalled_insns' is set).
2189 fsched-stalled-insns-dep
2190 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2191 Set dependence distance checking in premature scheduling of queued insns.
2193 fsched-stalled-insns-dep=
2194 Common RejectNegative Joined UInteger Optimization
2195 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2197 fsched-group-heuristic
2198 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2199 Enable the group heuristic in the scheduler.
2201 fsched-critical-path-heuristic
2202 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2203 Enable the critical path heuristic in the scheduler.
2205 fsched-spec-insn-heuristic
2206 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2207 Enable the speculative instruction heuristic in the scheduler.
2209 fsched-rank-heuristic
2210 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2211 Enable the rank heuristic in the scheduler.
2213 fsched-last-insn-heuristic
2214 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2215 Enable the last instruction heuristic in the scheduler.
2217 fsched-dep-count-heuristic
2218 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2219 Enable the dependent count heuristic in the scheduler.
2222 Common Report Var(flag_section_anchors) Optimization
2223 Access data in the same section from shared anchor points.
2227 Does nothing. Preserved for backward compatibility.
2231 Does nothing. Preserved for backward compatibility.
2234 Common Report Var(flag_ree) Init(0)
2235 Turn on Redundant Extensions Elimination pass.
2238 Common Report Var(flag_show_column) Init(1)
2239 Show column numbers in diagnostics, when available. Default on.
2242 Common Report Var(flag_shrink_wrap) Optimization
2243 Emit function prologues only before parts of the function that need it,
2244 rather than at the top of the function.
2246 fshrink-wrap-separate
2247 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2248 Shrink-wrap parts of the prologue and epilogue separately.
2251 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2252 Disable optimizations observable by IEEE signaling NaNs.
2255 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2256 Disable floating point optimizations that ignore the IEEE signedness of zero.
2258 fsingle-precision-constant
2259 Common Report Var(flag_single_precision_constant) Optimization
2260 Convert floating point constants to single precision constants.
2262 fsplit-ivs-in-unroller
2263 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2264 Split lifetimes of induction variables when loops are unrolled.
2267 Common Report Var(flag_split_stack) Init(-1)
2268 Generate discontiguous stack frames.
2271 Common Report Var(flag_split_wide_types) Optimization
2272 Split wide types into independent registers.
2275 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2276 Enable backward propagation of use properties at the SSA level.
2279 Common Report Var(flag_ssa_phiopt) Optimization
2280 Optimize conditional patterns using SSA PHI nodes.
2283 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2284 Optimize amount of stdarg registers saved to stack at start of function.
2286 fvariable-expansion-in-unroller
2287 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2288 Apply variable expansion when loops are unrolled.
2291 Common Report RejectNegative Joined
2292 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2295 Common Alias(fstack-check=, specific, no)
2296 Insert stack checking code into the program. Same as -fstack-check=specific.
2299 Common Var(common_deferred_options) Defer
2301 fstack-limit-register=
2302 Common RejectNegative Joined Var(common_deferred_options) Defer
2303 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2305 fstack-limit-symbol=
2306 Common RejectNegative Joined Var(common_deferred_options) Defer
2307 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2310 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2311 Use propolice as a stack protection method.
2313 fstack-protector-all
2314 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2315 Use a stack protection method for every function.
2317 fstack-protector-strong
2318 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2319 Use a smart stack protection method for certain functions.
2321 fstack-protector-explicit
2322 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2323 Use stack protection method only for functions with the stack_protect attribute.
2326 Common RejectNegative Var(flag_stack_usage)
2327 Output stack usage information on a per-function basis.
2331 Does nothing. Preserved for backward compatibility.
2333 ; Nonzero if we should do (language-dependent) alias analysis.
2334 ; Typically, this analysis will assume that expressions of certain
2335 ; types do not alias expressions of certain other types. Only used
2336 ; if alias analysis (in general) is enabled.
2338 Common Report Var(flag_strict_aliasing) Optimization
2339 Assume strict aliasing rules apply.
2342 Common Report Var(flag_strict_overflow) Optimization
2343 Treat signed overflow as undefined.
2346 Common Report Var(flag_sync_libcalls) Init(1)
2347 Implement __atomic operations via libcalls to legacy __sync functions.
2350 Common Report Var(flag_syntax_only)
2351 Check for syntax errors, then stop.
2354 Common Report Var(flag_test_coverage)
2355 Create data files needed by \"gcov\".
2358 Common Report Var(flag_thread_jumps) Optimization
2359 Perform jump threading optimizations.
2362 Common Report Var(time_report)
2363 Report the time taken by each compiler pass.
2365 ftime-report-details
2366 Common Report Var(time_report_details)
2367 Record times taken by sub-phases separately.
2370 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2371 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2374 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2377 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2380 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2383 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2386 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2389 Common Report Var(flag_toplevel_reorder) Init(2)
2390 Reorder top level functions, variables, and asms.
2393 Common Report Var(flag_tracer) Optimization
2394 Perform superblock formation via tail duplication.
2397 Common Report Var(flag_trampolines) Init(0)
2398 For targets that normally need trampolines for nested functions, always
2399 generate them instead of using descriptors.
2401 ; Zero means that floating-point math operations cannot generate a
2402 ; (user-visible) trap. This is the case, for example, in nonstop
2403 ; IEEE 754 arithmetic.
2405 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2406 Assume floating-point operations can trap.
2409 Common Report Var(flag_trapv) Optimization
2410 Trap for signed overflow in addition, subtraction and multiplication.
2413 Common Report Var(flag_tree_ccp) Optimization
2414 Enable SSA-CCP optimization on trees.
2417 Common Report Var(flag_tree_bit_ccp) Optimization
2418 Enable SSA-BIT-CCP optimization on trees.
2422 Does nothing. Preserved for backward compatibility.
2425 Common Report Var(flag_tree_ch) Optimization
2426 Enable loop header copying on trees.
2428 ftree-coalesce-inlined-vars
2429 Common Ignore RejectNegative
2430 Does nothing. Preserved for backward compatibility.
2433 Common Report Var(flag_tree_coalesce_vars) Optimization
2434 Enable SSA coalescing of user variables.
2438 Does nothing. Preserved for backward compatibility.
2441 Common Report Var(flag_tree_copy_prop) Optimization
2442 Enable copy propagation on trees.
2444 ftree-store-copy-prop
2446 Does nothing. Preserved for backward compatibility.
2449 Common Report Var(flag_tree_cselim) Init(2) Optimization
2450 Transform condition stores into unconditional ones.
2452 ftree-switch-conversion
2453 Common Report Var(flag_tree_switch_conversion) Optimization
2454 Perform conversions of switch initializations.
2457 Common Report Var(flag_tree_dce) Optimization
2458 Enable SSA dead code elimination optimization on trees.
2460 ftree-dominator-opts
2461 Common Report Var(flag_tree_dom) Optimization
2462 Enable dominator optimizations.
2465 Common Report Var(flag_tree_tail_merge) Optimization
2466 Enable tail merging on trees.
2469 Common Report Var(flag_tree_dse) Optimization
2470 Enable dead store elimination.
2473 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2474 Enable forward propagation on trees.
2477 Common Report Var(flag_tree_fre) Optimization
2478 Enable Full Redundancy Elimination (FRE) on trees.
2481 Common Report Var(flag_optimize_strlen) Optimization
2482 Enable string length optimizations on trees.
2484 fisolate-erroneous-paths-dereference
2485 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2486 Detect paths that trigger erroneous or undefined behavior due to
2487 dereferencing a null pointer. Isolate those paths from the main control
2488 flow and turn the statement with erroneous or undefined behavior into a trap.
2490 fisolate-erroneous-paths-attribute
2491 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2492 Detect paths that trigger erroneous or undefined behavior due a null value
2493 being used in a way forbidden by a returns_nonnull or nonnull
2494 attribute. Isolate those paths from the main control flow and turn the
2495 statement with erroneous or undefined behavior into a trap.
2497 ftree-loop-distribution
2498 Common Report Var(flag_tree_loop_distribution) Optimization
2499 Enable loop distribution on trees.
2501 ftree-loop-distribute-patterns
2502 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2503 Enable loop distribution for patterns transformed into a library call.
2506 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2507 Enable loop invariant motion on trees.
2510 Common Alias(floop-nest-optimize)
2511 Enable loop nest transforms. Same as -floop-nest-optimize.
2514 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2515 Create canonical induction variables in loops.
2518 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2519 Enable loop optimizations on tree level.
2521 ftree-parallelize-loops=
2522 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2523 Enable automatic parallelization of loops.
2526 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2527 Enable hoisting loads from conditional pointers.
2530 Common Report Var(flag_tree_pre) Optimization
2531 Enable SSA-PRE optimization on trees.
2534 Common Report Var(flag_tree_partial_pre) Optimization
2535 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2538 Common Report Var(flag_tree_pta) Optimization
2539 Perform function-local points-to analysis on trees.
2542 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2543 Enable reassociation on tree level.
2547 Does nothing. Preserved for backward compatibility.
2550 Common Report Var(flag_tree_sink) Optimization
2551 Enable SSA code sinking on trees.
2554 Common Report Var(flag_tree_slsr) Optimization
2555 Perform straight-line strength reduction.
2558 Common Report Var(flag_tree_sra) Optimization
2559 Perform scalar replacement of aggregates.
2562 Common Report Var(flag_tree_ter) Optimization
2563 Replace temporary expressions in the SSA->normal pass.
2566 Common Report Var(flag_tree_live_range_split) Optimization
2567 Perform live range splitting during the SSA->normal pass.
2570 Common Report Var(flag_tree_vrp) Init(0) Optimization
2571 Perform Value Range Propagation on trees.
2574 Common Report Var(flag_split_paths) Init(0) Optimization
2575 Split paths leading to loop backedges.
2577 funconstrained-commons
2578 Common Var(flag_unconstrained_commons) Optimization
2579 Assume common declarations may be overridden with ones with a larger
2583 Common Report Var(flag_unit_at_a_time) Init(1)
2584 Compile whole compilation unit at a time.
2587 Common Report Var(flag_unroll_loops) Optimization
2588 Perform loop unrolling when iteration count is known.
2591 Common Report Var(flag_unroll_all_loops) Optimization
2592 Perform loop unrolling for all loops.
2594 ; Nonzero means that loop optimizer may assume that the induction variables
2595 ; that control loops do not overflow and that the loops with nontrivial
2596 ; exit condition are not infinite
2597 funsafe-loop-optimizations
2599 Does nothing. Preserved for backward compatibility.
2602 Common Report Var(flag_associative_math) SetByCombined Optimization
2603 Allow optimization for floating-point arithmetic which may change the
2604 result of the operation due to rounding.
2607 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2608 Same as -fassociative-math for expressions which include division.
2610 ; Nonzero means that unsafe floating-point math optimizations are allowed
2611 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2612 ; are allowed to assume that their arguments and results are "normal"
2613 ; (e.g., nonnegative for SQRT).
2614 funsafe-math-optimizations
2615 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2616 Allow math optimizations that may violate IEEE or ISO standards.
2619 Common Report Var(flag_unswitch_loops) Optimization
2620 Perform loop unswitching.
2623 Common Report Var(flag_split_loops) Optimization
2624 Perform loop splitting.
2627 Common Report Var(flag_unwind_tables) Optimization
2628 Just generate unwind tables for exception handling.
2631 Common Driver Negative(fuse-ld=gold)
2632 Use the bfd linker instead of the default linker.
2635 Common Driver Negative(fuse-ld=bfd)
2636 Use the gold linker instead of the default linker.
2639 Common Undocumented Var(flag_use_linker_plugin)
2641 ; Positive if we should track variables, negative if we should run
2642 ; the var-tracking pass only to discard debug annotations, zero if
2643 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2644 ; will be set according to optimize, debug_info_level and debug_hooks
2645 ; in process_options ().
2647 Common Report Var(flag_var_tracking) Init(2) Optimization
2648 Perform variable tracking.
2650 ; Positive if we should track variables at assignments, negative if
2651 ; we should run the var-tracking pass only to discard debug
2652 ; annotations. When flag_var_tracking_assignments ==
2653 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2654 fvar-tracking-assignments
2655 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2656 Perform variable tracking by annotating assignments.
2658 ; Nonzero if we should toggle flag_var_tracking_assignments after
2659 ; processing options and computing its default. */
2660 fvar-tracking-assignments-toggle
2661 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2662 Toggle -fvar-tracking-assignments.
2664 ; Positive if we should track uninitialized variables, negative if
2665 ; we should run the var-tracking pass only to discard debug
2666 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2667 ; will be set according to flag_var_tracking.
2668 fvar-tracking-uninit
2669 Common Report Var(flag_var_tracking_uninit) Optimization
2670 Perform variable tracking and also tag variables that are uninitialized.
2673 Common Report Var(flag_tree_vectorize) Optimization
2674 Enable vectorization on trees.
2676 ftree-vectorizer-verbose=
2677 Common Joined RejectNegative Ignore
2678 Does nothing. Preserved for backward compatibility.
2680 ftree-loop-vectorize
2681 Common Report Var(flag_tree_loop_vectorize) Optimization
2682 Enable loop vectorization on trees.
2685 Common Report Var(flag_tree_slp_vectorize) Optimization
2686 Enable basic block vectorization (SLP) on trees.
2689 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2690 Specifies the cost model for vectorization.
2693 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2694 Specifies the vectorization cost model for code marked with a simd directive.
2697 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2700 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2703 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2706 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2709 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2710 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2713 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2714 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2716 ftree-vect-loop-version
2718 Does nothing. Preserved for backward compatibility.
2721 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2722 Enable copy propagation of scalar-evolution information.
2724 ; -fverbose-asm causes extra commentary information to be produced in
2725 ; the generated assembly code (to make it more readable). This option
2726 ; is generally only of use to those who actually need to read the
2727 ; generated assembly code (perhaps while debugging the compiler itself).
2728 ; -fno-verbose-asm, the default, causes the extra information
2729 ; to not be added and is useful when comparing two assembler files.
2731 Common Report Var(flag_verbose_asm)
2732 Add extra commentary to assembler output.
2735 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2736 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2739 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2742 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2745 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2748 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2751 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2754 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2755 Validate vtable pointers before using them.
2758 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2761 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2764 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2767 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2770 Common Var(flag_vtv_counts)
2771 Output vtable verification counters.
2774 Common Var(flag_vtv_debug)
2775 Output vtable verification pointer sets information.
2778 Common Report Var(flag_value_profile_transformations) Optimization
2779 Use expression value profiles in optimizations.
2782 Common Report Var(flag_web) Init(2) Optimization
2783 Construct webs and split unrelated uses of single variable.
2785 ftree-builtin-call-dce
2786 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2787 Enable conditional dead code elimination for builtin calls.
2790 Common Report Var(flag_whole_program) Init(0)
2791 Perform whole program optimizations.
2794 Common Report Var(flag_wrapv) Optimization
2795 Assume signed arithmetic overflow wraps around.
2797 fzero-initialized-in-bss
2798 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2799 Put zero initialized data in the bss section.
2802 Common JoinedOrMissing
2803 Generate debug information in default format.
2806 Common JoinedOrMissing Negative(gdwarf)
2807 Generate debug information in COFF format.
2810 Common JoinedOrMissing Negative(gdwarf-)
2811 Generate debug information in default version of DWARF format.
2814 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2815 Generate debug information in DWARF v2 (or later) format.
2818 Common JoinedOrMissing
2819 Generate debug information in default extended format.
2822 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2823 Don't generate DWARF pubnames and pubtypes sections.
2826 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2827 Generate DWARF pubnames and pubtypes sections.
2830 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2831 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2833 gno-record-gcc-switches
2834 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2835 Don't record gcc command line switches in DWARF DW_AT_producer.
2837 grecord-gcc-switches
2838 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2839 Record gcc command line switches in DWARF DW_AT_producer.
2842 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2843 Don't generate debug information in separate .dwo files.
2846 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2847 Generate debug information in separate .dwo files.
2850 Common JoinedOrMissing Negative(gstabs+)
2851 Generate debug information in STABS format.
2854 Common JoinedOrMissing Negative(gvms)
2855 Generate debug information in extended STABS format.
2858 Common RejectNegative Var(dwarf_strict,0) Init(0)
2859 Emit DWARF additions beyond selected version.
2862 Common Report RejectNegative Var(dwarf_strict,1)
2863 Don't emit DWARF additions beyond selected version.
2866 Common Report Var(flag_gtoggle)
2867 Toggle debug information generation.
2870 Common JoinedOrMissing Negative(gxcoff)
2871 Generate debug information in VMS format.
2874 Common JoinedOrMissing Negative(gxcoff+)
2875 Generate debug information in XCOFF format.
2878 Common JoinedOrMissing Negative(gcoff)
2879 Generate debug information in extended XCOFF format.
2882 Name(compressed_debug_sections) Type(int)
2884 ; Since -gz= is completely handled in specs, the values aren't used and we
2885 ; assign arbitrary constants.
2887 Enum(compressed_debug_sections) String(none) Value(0)
2890 Enum(compressed_debug_sections) String(zlib) Value(1)
2893 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2897 Generate compressed debug sections.
2900 Common Driver Joined Enum(compressed_debug_sections)
2901 -gz=<format> Generate compressed debug sections in format <format>.
2904 Driver Joined Separate
2907 Common Joined Var(plugindir_string) Init(0)
2908 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2911 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2912 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2915 Driver Joined Separate
2920 no-canonical-prefixes
2933 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2934 -o <file> Place output into <file>.
2937 Common Var(profile_flag)
2938 Enable function profiling.
2941 Driver Var(pass_exit_codes)
2944 Common Alias(Wpedantic)
2947 Common Var(flag_pedantic_errors)
2948 Like -pedantic but issue them as errors.
2954 Driver Var(use_pipes)
2957 Driver JoinedOrMissing Var(print_file_name)
2959 print-libgcc-file-name
2962 print-multi-directory
2963 Driver Var(print_multi_directory)
2966 Driver Var(print_multi_lib)
2968 print-multi-os-directory
2969 Driver Var(print_multi_os_directory)
2972 Driver Var(print_multiarch)
2975 Driver JoinedOrMissing Var(print_prog_name)
2978 Driver Var(print_search_dirs)
2981 Driver Var(print_sysroot)
2983 print-sysroot-headers-suffix
2984 Driver Var(print_sysroot_headers_suffix)
2987 Common Var(quiet_flag) RejectDriver
2988 Do not display functions compiled or elapsed time.
3006 Driver Var(report_times)
3009 Driver JoinedOrMissing
3012 Driver Joined Separate
3016 ; C option, but driver must not handle as "-u ndef".
3019 Common Driver Var(verbose_flag)
3020 Enable verbose output.
3023 Common Var(version_flag) RejectDriver
3024 Display the compiler's version.
3027 Common Var(inhibit_warnings)
3031 Driver Separate Var(wrapper_string)
3034 Driver Joined Separate
3037 Driver RejectNegative Negative(pie)
3038 Create a shared library.
3044 Driver Separate Alias(specs=)
3057 ; Documented for Fortran, but always accepted by driver.
3064 ; Documented for Go, but always accepted by driver.
3082 Driver RejectNegative Negative(shared)
3083 Don't create a position independent executable.
3086 Driver RejectNegative Negative(no-pie)
3087 Create a position independent executable.
3090 Driver Joined Separate
3093 Common Report Var(flag_ipa_ra) Optimization
3094 Use caller save register across calls if possible.
3096 ; This comment is to ensure we retain the blank line above.