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 Var(warn_implicit_fallthrough) Warning EnabledBy(Wextra)
606 Warn when a switch case falls through.
609 Common Var(warn_inline) Warning
610 Warn when an inlined function cannot be inlined.
612 Winvalid-memory-model
613 Common Var(warn_invalid_memory_model) Init(1) Warning
614 Warn when an atomic memory model parameter is known to be outside the valid range.
617 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
620 Common RejectNegative Joined UInteger Warning
621 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
624 Var(warn_nonnull_compare) Warning
625 Warn if comparing pointer parameter with nonnull attribute with NULL.
628 Common Var(warn_null_dereference) Warning
629 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
631 Wunsafe-loop-optimizations
632 Common Var(warn_unsafe_loop_optimizations) Warning
633 Warn if the loop cannot be optimized due to nontrivial assumptions.
636 Common Warning Alias(Wsuggest-attribute=noreturn)
639 Common Var(warn_odr_violations) Init(1) Warning
640 Warn about some C++ One Definition Rule violations during link time optimization.
643 Common Var(warn_overflow) Init(1) Warning
644 Warn about overflow in arithmetic expressions.
647 Common Var(warn_lto_type_mismatch) Init(1) Warning
648 During link time optimization warn about mismatched types of global declarations.
651 Common Var(warn_packed) Warning
652 Warn when the packed attribute has no effect on struct layout.
655 Common Var(warn_padded) Warning
656 Warn when padding is required to align structure members.
659 Common Var(pedantic) Init(0) Warning
660 Issue warnings needed for strict compliance to the standard.
663 Common Var(warn_return_local_addr) Init(1) Warning
664 Warn about returning a pointer/reference to a local or temporary variable.
667 Common Var(warn_shadow) Warning
668 Warn when one local variable shadows another.
671 Common Var(warn_stack_protect) Warning
672 Warn when not issuing stack smashing protection for some reason.
675 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
676 Warn if stack usage might be larger than specified amount.
680 Warn about code which might break strict aliasing rules.
683 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
684 Warn about code which might break strict aliasing rules.
688 Warn about optimizations that assume that signed overflow is undefined.
691 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
692 Warn about optimizations that assume that signed overflow is undefined.
694 Wsuggest-attribute=const
695 Common Var(warn_suggest_attribute_const) Warning
696 Warn about functions which might be candidates for __attribute__((const)).
698 Wsuggest-attribute=pure
699 Common Var(warn_suggest_attribute_pure) Warning
700 Warn about functions which might be candidates for __attribute__((pure)).
702 Wsuggest-attribute=noreturn
703 Common Var(warn_suggest_attribute_noreturn) Warning
704 Warn about functions which might be candidates for __attribute__((noreturn)).
707 Common Var(warn_suggest_final_types) Warning
708 Warn about C++ polymorphic types where adding final keyword would improve code quality.
710 Wsuggest-final-methods
711 Common Var(warn_suggest_final_methods) Warning
712 Warn about C++ virtual methods where adding final keyword would improve code quality.
715 Common Var(warn_switch_unreachable) Warning Init(1)
716 Warn about statements between switch's controlling expression and the first
720 Common Var(warn_system_headers) Warning
721 Do not suppress warnings from system headers.
724 Common Var(warn_trampolines) Warning
725 Warn whenever a trampoline is generated.
728 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
729 Warn if a comparison is always true or always false due to the limited range of the data type.
732 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
733 Warn about uninitialized automatic variables.
736 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
737 Warn about maybe uninitialized automatic variables.
740 Common Ignore Warning
741 Does nothing. Preserved for backward compatibility.
744 Common Var(warn_unused) Init(0) Warning
745 Enable all -Wunused- warnings.
747 Wunused-but-set-parameter
748 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
749 Warn when a function parameter is only set, otherwise unused.
751 Wunused-but-set-variable
752 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
753 Warn when a variable is only set, otherwise unused.
756 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
757 Warn when a function is unused.
760 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
761 Warn when a label is unused.
764 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
765 Warn when a function parameter is unused.
768 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
769 Warn when an expression value is unused.
772 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
773 Warn when a variable is unused.
776 Common Var(warn_coverage_mismatch) Init(1) Warning
777 Warn in case profiles in -fprofile-use do not match.
779 Wvector-operation-performance
780 Common Var(warn_vector_operation_performance) Warning
781 Warn when a vector operation is compiled outside the SIMD.
796 Common Separate Var(aux_info_file_name)
797 -aux-info <file> Emit declaration information into <file>.
800 Common Joined Alias(aux-info)
803 Common Separate RejectDriver Var(aux_base_name)
806 Common Separate RejectDriver
816 -d<letters> Enable dumps from specific passes of the compiler.
819 Common Separate Var(dump_base_name)
820 -dumpbase <file> Set the file basename to be used for dumps.
823 Common Separate Var(dump_dir_name)
824 -dumpdir <dir> Set the directory name to be used for dumps.
836 Driver Joined Separate
838 ; This option has historically been passed down to the linker by an
839 ; accident of a %{e*} spec, so ensure it continues to be passed down
840 ; as a single option. The supported option for this purpose is
841 ; -rdynamic. See PR 47390.
845 ; The version of the C++ ABI in use. The following values are allowed:
847 ; 0: The version of the ABI believed most conformant with the C++ ABI
848 ; specification. This ABI may change as bugs are discovered and fixed.
849 ; Therefore, 0 will not necessarily indicate the same ABI in different
852 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
854 ; 2: The version of the ABI first used in G++ 3.4, and the default
857 ; 3: The version of the ABI that fixes the missing underscore
858 ; in template non-type arguments of pointer type.
860 ; 4: The version of the ABI that introduces unambiguous mangling of
861 ; vector types. First selectable in G++ 4.5.
863 ; 5: The version of the ABI that ignores attribute const/noreturn
864 ; in function pointer mangling, and corrects mangling of decltype and
865 ; function parameters used in other parameters and the return type.
866 ; First selectable in G++ 4.6.
868 ; 6: The version of the ABI that doesn't promote scoped enums to int and
869 ; changes the mangling of template argument packs, const/static_cast,
870 ; prefix ++ and --, and a class scope function used as a template
872 ; First selectable in G++ 4.7.
874 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
875 ; corrects the mangling of lambdas in default argument scope.
876 ; First selectable in G++ 4.8.
878 ; 8: The version of the ABI that corrects the substitution behavior of
879 ; function types with function-cv-qualifiers.
880 ; First selectable in G++ 4.9 and default in G++ 5.
882 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
883 ; First selectable and default in G++ 5.2.
885 ; 10: The version of the ABI that mangles attributes that affect type
886 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
887 ; Default in G++ 6 (set in c_common_post_options).
889 ; 11: The version of the ABI that corrects mangling of sizeof... expressions.
892 ; Additional positive integers will be assigned as new versions of
893 ; the ABI become the default version of the ABI.
895 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
896 The version of the C++ ABI in use.
898 faggressive-loop-optimizations
899 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
900 Aggressively optimize loops using language constraints.
903 Common Report Var(align_functions,0) Optimization UInteger
904 Align the start of functions.
907 Common RejectNegative Joined UInteger Var(align_functions)
910 Common Report Var(align_jumps,0) Optimization UInteger
911 Align labels which are only reached by jumping.
914 Common RejectNegative Joined UInteger Var(align_jumps)
917 Common Report Var(align_labels,0) Optimization UInteger
921 Common RejectNegative Joined UInteger Var(align_labels)
924 Common Report Var(align_loops,0) Optimization UInteger
925 Align the start of loops.
928 Common RejectNegative Joined UInteger Var(align_loops)
932 Does nothing. Preserved for backward compatibility.
936 Does nothing. Preserved for backward compatibility.
938 fargument-noalias-global
940 Does nothing. Preserved for backward compatibility.
942 fargument-noalias-anything
944 Does nothing. Preserved for backward compatibility.
947 Common Driver Report Joined
948 Select what to sanitize.
951 Common Joined RejectNegative Var(common_deferred_options) Defer
952 -fasan-shadow-offset=<number> Use custom shadow memory offset.
955 Common Joined RejectNegative Var(common_deferred_options) Defer
956 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
957 in user-defined sections.
961 After diagnosing undefined behavior attempt to continue execution.
965 This switch is deprecated; use -fsanitize-recover= instead.
967 fsanitize-undefined-trap-on-error
968 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
969 Use trap instead of a library function for undefined behavior sanitization.
971 fasynchronous-unwind-tables
972 Common Report Var(flag_asynchronous_unwind_tables) Optimization
973 Generate unwind tables that are exact at each instruction boundary.
976 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
977 Generate auto-inc/dec instructions.
980 Common Report Var(flag_auto_profile)
981 Use sample profile information for call graph node weights. The default
982 profile file is fbdata.afdo in 'pwd'.
985 Common Joined RejectNegative Var(auto_profile_file)
986 Use sample profile information for call graph node weights. The profile
987 file is specified in the argument.
989 ; -fcheck-bounds causes gcc to generate array bounds checks.
990 ; For C, C++ and ObjC: defaults off.
991 ; For Java: defaults to on.
992 ; For Fortran: defaults to off.
994 Common Report Var(flag_bounds_check)
995 Generate code to check bounds before indexing arrays.
998 Common Report Var(flag_branch_on_count_reg) Optimization
999 Replace add, compare, branch with branch on count register.
1001 fbranch-probabilities
1002 Common Report Var(flag_branch_probabilities) Optimization
1003 Use profiling information for branch probabilities.
1005 fbranch-target-load-optimize
1006 Common Report Var(flag_branch_target_load_optimize) Optimization
1007 Perform branch target load optimization before prologue / epilogue threading.
1009 fbranch-target-load-optimize2
1010 Common Report Var(flag_branch_target_load_optimize2) Optimization
1011 Perform branch target load optimization after prologue / epilogue threading.
1014 Common Report Var(flag_btr_bb_exclusive) Optimization
1015 Restrict target load migration not to re-use registers in any basic block.
1018 Common Joined RejectNegative Var(common_deferred_options) Defer
1019 -fcall-saved-<register> Mark <register> as being preserved across functions.
1022 Common Joined RejectNegative Var(common_deferred_options) Defer
1023 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1025 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1026 ; be saved across function calls, if that produces overall better code.
1027 ; Optional now, so people can test it.
1029 Common Report Var(flag_caller_saves) Optimization
1030 Save registers around function calls.
1033 Common Report Var(flag_check_data_deps)
1034 This switch is deprecated; do not use.
1037 Common Var(flag_check_new)
1038 Check the return value of new in C++.
1041 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1042 Perform internal consistency checkings.
1045 Common Joined RejectNegative UInteger Var(flag_checking)
1046 Perform internal consistency checkings.
1049 Common Report Var(flag_code_hoisting) Optimization
1050 Enable code hoisting.
1052 fcombine-stack-adjustments
1053 Common Report Var(flag_combine_stack_adjustments) Optimization
1054 Looks for opportunities to reduce stack adjustments and stack references.
1057 Common Report Var(flag_no_common,0)
1058 Do not put uninitialized globals in the common section.
1062 ; Converted by the driver to -fcompare-debug= options.
1065 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1066 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1068 fcompare-debug-second
1069 Common Driver RejectNegative Var(flag_compare_debug)
1070 Run only the second compilation of -fcompare-debug.
1073 Common Report Var(flag_compare_elim_after_reload) Optimization
1074 Perform comparison elimination after register allocation has finished.
1077 Common Var(flag_conserve_stack) Optimization
1078 Do not perform optimizations increasing noticeably stack usage.
1081 Common Report Var(flag_cprop_registers) Optimization
1082 Perform a register copy-propagation optimization pass.
1085 Common Report Var(flag_crossjumping) Optimization
1086 Perform cross-jumping optimization.
1089 Common Report Var(flag_cse_follow_jumps) Optimization
1090 When running CSE, follow jumps to their targets.
1094 Does nothing. Preserved for backward compatibility.
1097 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1098 Omit range reduction step when performing complex division.
1101 Common Report Var(flag_cx_fortran_rules) Optimization
1102 Complex multiplication and division follow Fortran rules.
1105 Common Report Var(flag_data_sections)
1106 Place data items into their own section.
1109 Common Report Var(common_deferred_options) Defer
1110 List all available debugging counters with their limits and counts.
1113 Common RejectNegative Joined Var(common_deferred_options) Defer
1114 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1117 Common Joined RejectNegative Var(common_deferred_options) Defer
1118 Map one directory name to another in debug information.
1120 fdebug-types-section
1121 Common Report Var(flag_debug_types_section) Init(0)
1122 Output .debug_types section when using DWARF v4 debuginfo.
1124 ; Nonzero for -fdefer-pop: don't pop args after each function call
1125 ; instead save them up to pop many calls' args with one insns.
1127 Common Report Var(flag_defer_pop) Optimization
1128 Defer popping functions args from stack until later.
1131 Common Report Var(flag_delayed_branch) Optimization
1132 Attempt to fill delay slots of branch instructions.
1134 fdelete-dead-exceptions
1135 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1136 Delete dead instructions that may throw exceptions.
1138 fdelete-null-pointer-checks
1139 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1140 Delete useless null pointer checks.
1142 fdevirtualize-at-ltrans
1143 Common Report Var(flag_ltrans_devirtualize)
1144 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1146 fdevirtualize-speculatively
1147 Common Report Var(flag_devirtualize_speculatively) Optimization
1148 Perform speculative devirtualization.
1151 Common Report Var(flag_devirtualize) Optimization
1152 Try to convert virtual calls to direct ones.
1154 fdiagnostics-show-location=
1155 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1156 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1158 ; Required for these enum values.
1163 Name(diagnostic_prefixing_rule) Type(int)
1166 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1169 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1171 fdiagnostics-show-caret
1172 Common Var(flag_diagnostics_show_caret) Init(1)
1173 Show the source line with a caret indicating the column.
1176 Common Alias(fdiagnostics-color=,always,never)
1180 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1181 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1183 ; Required for these enum values.
1188 Name(diagnostic_color_rule) Type(int)
1191 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1194 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1197 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1199 fdiagnostics-parseable-fixits
1200 Common Var(flag_diagnostics_parseable_fixits)
1201 Print fixit hints in machine-readable form.
1203 fdiagnostics-generate-patch
1204 Common Var(flag_diagnostics_generate_patch)
1205 Print fix-it hints to stderr in unified diff format.
1207 fdiagnostics-show-option
1208 Common Var(flag_diagnostics_show_option) Init(1)
1209 Amend appropriate diagnostic messages with the command line option that controls them.
1212 Common Joined RejectNegative Var(common_deferred_options) Defer
1213 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1216 Common Joined RejectNegative Var(common_deferred_options) Defer
1217 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1220 Common Joined RejectNegative Var(common_deferred_options) Defer
1221 -fdump-<type> Dump various compiler internals to a file.
1224 Driver RejectNegative
1227 Common RejectNegative Joined Var(flag_dump_final_insns)
1228 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1231 Common RejectNegative Joined Var(flag_dump_go_spec)
1232 -fdump-go-spec=filename Write all declarations to file as Go code.
1235 Common Report Var(flag_dump_noaddr)
1236 Suppress output of addresses in debugging dumps.
1239 Common Driver Var(flag_report_bug)
1240 Collect and dump debug information into temporary file if ICE in C/C++
1243 fdump-internal-locations
1244 Common Var(flag_dump_locations) Init(0)
1245 Dump detailed information on GCC's internal representation of source code locations.
1248 Common Var(flag_dump_passes) Init(0)
1249 Dump optimization passes.
1252 Common Report Var(flag_dump_unnumbered)
1253 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1255 fdump-unnumbered-links
1256 Common Report Var(flag_dump_unnumbered_links)
1257 Suppress output of previous and next insn numbers in debugging dumps.
1260 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1261 Enable CFI tables via GAS assembler directives.
1264 Common Report Var(flag_early_inlining) Init(1) Optimization
1265 Perform early inlining.
1267 feliminate-dwarf2-dups
1268 Common Report Var(flag_eliminate_dwarf2_dups)
1269 Perform DWARF duplicate elimination.
1272 Common Report Var(flag_ipa_sra) Init(0) Optimization
1273 Perform interprocedural reduction of aggregates.
1275 feliminate-unused-debug-symbols
1276 Common Report Var(flag_debug_only_used_symbols)
1277 Perform unused symbol elimination in debug info.
1279 feliminate-unused-debug-types
1280 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1281 Perform unused type elimination in debug info.
1283 femit-class-debug-always
1284 Common Report Var(flag_emit_class_debug_always) Init(0)
1285 Do not suppress C++ class debug information.
1288 Common Report Var(flag_exceptions) Optimization
1289 Enable exception handling.
1291 fexpensive-optimizations
1292 Common Report Var(flag_expensive_optimizations) Optimization
1293 Perform a number of minor, expensive optimizations.
1296 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1297 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1300 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1303 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1306 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1312 Common Var(flag_fat_lto_objects)
1313 Output lto objects containing both the intermediate language and binary output.
1316 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1317 Assume no NaNs or infinities are generated.
1320 Common Joined RejectNegative Var(common_deferred_options) Defer
1321 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1324 Common Report Var(flag_float_store) Optimization
1325 Don't allocate floats and doubles in extended-precision registers.
1329 Does nothing. Preserved for backward compatibility.
1332 Common Report Var(flag_forward_propagate) Optimization
1333 Perform a forward propagation pass on RTL.
1336 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1337 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1340 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1343 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1345 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1347 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1350 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1352 ffp-int-builtin-inexact
1353 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1354 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1356 ; Nonzero means don't put addresses of constant functions in registers.
1357 ; Used for compiling the Unix kernel, where strange substitutions are
1358 ; done on the assembly output.
1360 Common Report Var(flag_no_function_cse,0) Optimization
1361 Allow function addresses to be held in registers.
1364 Common Report Var(flag_function_sections)
1365 Place each function into its own section.
1368 Common Report Var(flag_gcse) Optimization
1369 Perform global common subexpression elimination.
1372 Common Report Var(flag_gcse_lm) Init(1) Optimization
1373 Perform enhanced load motion during global common subexpression elimination.
1376 Common Report Var(flag_gcse_sm) Init(0) Optimization
1377 Perform store motion after global common subexpression elimination.
1380 Common Report Var(flag_gcse_las) Init(0) Optimization
1381 Perform redundant load after store elimination in global common subexpression
1385 Common Report Var(flag_gcse_after_reload) Optimization
1386 Perform global common subexpression elimination after register allocation has
1390 Name(dwarf_gnat_encodings) Type(int)
1393 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1396 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1399 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1402 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1403 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1405 ; This option is not documented yet as its semantics will change.
1407 Common Report Var(flag_graphite) Optimization
1408 Enable in and out of Graphite representation.
1411 Common Report Var(flag_graphite_identity) Optimization
1412 Enable Graphite Identity transformation.
1414 fhoist-adjacent-loads
1415 Common Report Var(flag_hoist_adjacent_loads) Optimization
1416 Enable hoisting adjacent loads to encourage generating conditional move
1420 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1421 ; Always keep a pointer to a live memory block
1423 floop-parallelize-all
1424 Common Report Var(flag_loop_parallelize_all) Optimization
1425 Mark all loops as parallel.
1428 Common Alias(floop-nest-optimize)
1429 Enable loop nest transforms. Same as -floop-nest-optimize.
1432 Common Alias(floop-nest-optimize)
1433 Enable loop nest transforms. Same as -floop-nest-optimize.
1436 Common Alias(floop-nest-optimize)
1437 Enable loop nest transforms. Same as -floop-nest-optimize.
1439 floop-unroll-and-jam
1440 Common Alias(floop-nest-optimize)
1441 Enable loop nest transforms. Same as -floop-nest-optimize.
1444 Common Report Var(flag_tm)
1445 Enable support for GNU transactional memory.
1448 Common Report Var(flag_gnu_unique) Init(1)
1449 Use STB_GNU_UNIQUE if supported by the assembler.
1453 Does nothing. Preserved for backward compatibility.
1456 Common Report Var(flag_loop_nest_optimize) Optimization
1457 Enable the loop nest optimizer.
1459 fstrict-volatile-bitfields
1460 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1461 Force bitfield accesses to match their type width.
1463 fguess-branch-probability
1464 Common Report Var(flag_guess_branch_prob) Optimization
1465 Enable guessing of branch probabilities.
1467 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1468 ; Generate position-independent code for executables if possible
1469 ; On SVR4 targets, it also controls whether or not to emit a
1470 ; string identifying the compiler.
1472 Common Report Var(flag_no_ident,0)
1473 Process #ident directives.
1476 Common Report Var(flag_if_conversion) Optimization
1477 Perform conversion of conditional jumps to branchless equivalents.
1480 Common Report Var(flag_if_conversion2) Optimization
1481 Perform conversion of conditional jumps to conditional execution.
1484 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1485 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1488 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1491 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1494 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1497 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1499 ftree-loop-if-convert
1500 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1501 Convert conditional jumps in innermost loops to branchless equivalents.
1503 ftree-loop-if-convert-stores
1504 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1505 Also if-convert conditional jumps containing memory writes.
1507 ; -finhibit-size-directive inhibits output of .size for ELF.
1508 ; This is used only for compiling crtstuff.c,
1509 ; and it may be extended to other effects
1510 ; needed for crtstuff.c on other systems.
1511 finhibit-size-directive
1512 Common Report Var(flag_inhibit_size_directive)
1513 Do not generate .size directives.
1516 Common Report Var(flag_indirect_inlining) Optimization
1517 Perform indirect inlining.
1519 ; General flag to enable inlining. Specifying -fno-inline will disable
1520 ; all inlining apart from always-inline functions.
1522 Common Report Var(flag_no_inline,0) Init(0) Optimization
1523 Enable inlining of function declared \"inline\", disabling disables all inlining.
1525 finline-small-functions
1526 Common Report Var(flag_inline_small_functions) Optimization
1527 Integrate functions into their callers when code size is known not to grow.
1530 Common Report Var(flag_inline_functions) Optimization
1531 Integrate functions not declared \"inline\" into their callers when profitable.
1533 finline-functions-called-once
1534 Common Report Var(flag_inline_functions_called_once) Optimization
1535 Integrate functions only required by their single caller.
1538 Common RejectNegative Joined Alias(finline-limit=)
1541 Common RejectNegative Joined UInteger
1542 -finline-limit=<number> Limit the size of inlined functions to <number>.
1545 Common Report Var(flag_inline_atomics) Init(1) Optimization
1546 Inline __atomic operations when a lock free instruction sequence is available.
1548 finstrument-functions
1549 Common Report Var(flag_instrument_function_entry_exit)
1550 Instrument function entry and exit with profiling calls.
1552 finstrument-functions-exclude-function-list=
1553 Common RejectNegative Joined
1554 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1556 finstrument-functions-exclude-file-list=
1557 Common RejectNegative Joined
1558 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1561 Common Report Var(flag_ipa_cp) Optimization
1562 Perform interprocedural constant propagation.
1565 Common Report Var(flag_ipa_cp_clone) Optimization
1566 Perform cloning to make Interprocedural constant propagation stronger.
1569 Common Report Var(flag_ipa_cp_alignment) Optimization
1570 Perform alignment discovery and propagation to make Interprocedural constant propagation stronger.
1573 Common Report Var(flag_ipa_bit_cp) Optimization
1574 Perform interprocedural bitwise constant propagation.
1577 Common Report Var(flag_ipa_profile) Init(0) Optimization
1578 Perform interprocedural profile propagation.
1581 Common Report Var(flag_ipa_pta) Init(0) Optimization
1582 Perform interprocedural points-to analysis.
1585 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1586 Discover pure and const functions.
1589 Common Report Var(flag_ipa_icf) Optimization
1590 Perform Identical Code Folding for functions and read-only variables.
1593 Common Report Var(flag_ipa_icf_functions) Optimization
1594 Perform Identical Code Folding for functions.
1597 Common Report Var(flag_ipa_icf_variables)
1598 Perform Identical Code Folding for variables.
1601 Common Report Var(flag_ipa_reference) Init(0) Optimization
1602 Discover readonly and non addressable static variables.
1606 Does nothing. Preserved for backward compatibility.
1610 Does nothing. Preserved for backward compatibility.
1613 Common Report Var(flag_ipa_vrp) Optimization
1614 Perform IPA Value Range Propagation.
1617 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1618 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1621 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1624 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1627 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1630 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1631 -fira-region=[one|all|mixed] Set regions for IRA.
1634 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1637 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1640 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1643 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1646 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1647 Use IRA based register pressure calculation
1648 in RTL hoist optimizations.
1651 Common Report Var(flag_ira_loop_pressure) Optimization
1652 Use IRA based register pressure calculation
1653 in RTL loop optimizations.
1655 fira-share-save-slots
1656 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1657 Share slots for saving different hard registers.
1659 fira-share-spill-slots
1660 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1661 Share stack slots for spilled pseudo-registers.
1664 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1665 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1668 Common Report Var(flag_ivopts) Init(1) Optimization
1669 Optimize induction variables on trees.
1672 Common Var(flag_jump_tables) Init(1) Optimization
1673 Use jump tables for sufficiently large switch statements.
1675 fkeep-inline-functions
1676 Common Report Var(flag_keep_inline_functions)
1677 Generate code for functions even if they are fully inlined.
1679 fkeep-static-functions
1680 Common Report Var(flag_keep_static_functions)
1681 Generate code for static functions even if they are never called.
1684 Common Report Var(flag_keep_static_consts) Init(1)
1685 Emit static const variables even if they are not used.
1688 Common Report Var(flag_leading_underscore) Init(-1)
1689 Give external symbols a leading underscore.
1693 Does nothing. Preserved for backward compatibility.
1696 Common Report Var(flag_lra_remat) Optimization
1697 Do CFG-sensitive rematerialization in LRA.
1701 Enable link-time optimization.
1704 Common RejectNegative Joined Var(flag_lto)
1705 Link-time optimization with number of parallel jobs or jobserver.
1708 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1711 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1714 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1717 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1720 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1723 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1726 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1727 Specify the algorithm to partition symbols and vars at linktime.
1729 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1730 flto-compression-level=
1731 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1732 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1734 flto-odr-type-merging
1735 Common Report Var(flag_lto_odr_type_mering) Init(1)
1736 Merge C++ types using One Definition Rule.
1739 Common Report Var(flag_lto_report) Init(0)
1740 Report various link-time optimization statistics.
1743 Common Report Var(flag_lto_report_wpa) Init(0)
1744 Report various link-time optimization statistics for WPA only.
1747 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1748 Set errno after built-in math functions.
1751 Common Joined RejectNegative UInteger Var(flag_max_errors)
1752 -fmax-errors=<number> Maximum number of errors to report.
1755 Common Report Var(mem_report)
1756 Report on permanent memory allocation.
1759 Common Report Var(mem_report_wpa)
1760 Report on permanent memory allocation in WPA only.
1762 ; This will attempt to merge constant section constants, if 1 only
1763 ; string constants and constants from constant pool, if 2 also constant
1765 fmerge-all-constants
1766 Common Report Var(flag_merge_constants,2) Init(1)
1767 Attempt to merge identical constants and constant variables.
1770 Common Report Var(flag_merge_constants,1)
1771 Attempt to merge identical constants across compilation units.
1773 fmerge-debug-strings
1774 Common Report Var(flag_merge_debug_strings) Init(1)
1775 Attempt to merge identical debug strings across compilation units.
1778 Common RejectNegative Joined UInteger
1779 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1782 Common Report Var(flag_modulo_sched) Optimization
1783 Perform SMS based modulo scheduling before the first scheduling pass.
1785 fmodulo-sched-allow-regmoves
1786 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1787 Perform SMS based modulo scheduling with register moves allowed.
1789 fmove-loop-invariants
1790 Common Report Var(flag_move_loop_invariants) Optimization
1791 Move loop invariant computations out of loops.
1794 Common Var(flag_dce) Init(1) Optimization
1795 Use the RTL dead code elimination pass.
1798 Common Var(flag_dse) Init(1) Optimization
1799 Use the RTL dead store elimination pass.
1801 freschedule-modulo-scheduled-loops
1802 Common Report Var(flag_resched_modulo_sched) Optimization
1803 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1805 fnon-call-exceptions
1806 Common Report Var(flag_non_call_exceptions) Optimization
1807 Support synchronous non-call exceptions.
1810 Common Driver Joined MissingArgError(options or targets missing after %qs)
1811 -foffload=<targets>=<options> Specify offloading targets and options for them.
1814 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1815 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1818 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1821 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1824 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1827 Common Report Var(flag_omit_frame_pointer) Optimization
1828 When possible do not generate stack frames.
1831 Common Report Var(flag_opt_info) Optimization
1832 Enable all optimization info dumps on stderr.
1835 Common Joined RejectNegative Var(common_deferred_options) Defer
1836 -fopt-info[-<type>=filename] Dump compiler optimization details.
1838 foptimize-register-move
1840 Does nothing. Preserved for backward compatibility.
1842 foptimize-sibling-calls
1843 Common Report Var(flag_optimize_sibling_calls) Optimization
1844 Optimize sibling and tail recursive calls.
1847 Common Report Var(flag_partial_inlining) Optimization
1848 Perform partial inlining.
1851 Common Report Var(pre_ipa_mem_report)
1852 Report on memory allocation before interprocedural optimization.
1854 fpost-ipa-mem-report
1855 Common Report Var(post_ipa_mem_report)
1856 Report on memory allocation before interprocedural optimization.
1859 Common Report Var(flag_pack_struct) Optimization
1860 Pack structure members together without holes.
1863 Common RejectNegative Joined UInteger Optimization
1864 -fpack-struct=<number> Set initial maximum structure member alignment.
1867 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1868 Return small aggregates in memory, not registers.
1871 Common Report Var(flag_peel_loops) Optimization
1872 Perform loop peeling.
1875 Common Report Var(flag_no_peephole,0) Optimization
1876 Enable machine specific peephole optimizations.
1879 Common Report Var(flag_peephole2) Optimization
1880 Enable an RTL peephole pass before sched2.
1883 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1884 Generate position-independent code if possible (large mode).
1887 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1888 Generate position-independent code for executables if possible (large mode).
1891 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1892 Generate position-independent code if possible (small mode).
1895 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1896 Generate position-independent code for executables if possible (small mode).
1899 Common Report Var(flag_plt) Init(1) Optimization
1900 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
1903 Common Joined RejectNegative Var(common_deferred_options) Defer
1904 Specify a plugin to load.
1907 Common Joined RejectNegative Var(common_deferred_options) Defer
1908 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
1910 fpredictive-commoning
1911 Common Report Var(flag_predictive_commoning) Optimization
1912 Run predictive commoning optimization.
1914 fprefetch-loop-arrays
1915 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1916 Generate prefetch instructions, if available, for arrays in loops.
1919 Common Report Var(profile_flag)
1920 Enable basic program profiling code.
1923 Common Report Var(profile_arc_flag)
1924 Insert arc-based program profiling code.
1927 Common Joined RejectNegative Var(profile_data_prefix)
1928 Set the top-level directory for storing the profile data.
1929 The default is 'pwd'.
1932 Common Report Var(flag_profile_correction)
1933 Enable correction of flow inconsistent profile data input.
1936 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
1937 -fprofile-update=[single|atomic] Set the profile update method.
1940 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
1943 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
1946 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
1950 Enable common options for generating profile info for profile feedback directed optimizations.
1953 Common Joined RejectNegative
1954 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
1957 Common Var(flag_profile_use)
1958 Enable common options for performing profile feedback directed optimizations.
1961 Common Joined RejectNegative
1962 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
1965 Common Report Var(flag_profile_values)
1966 Insert code to profile values of expressions.
1969 Common Report Var(profile_report)
1970 Report on consistency of profile.
1972 fprofile-reorder-functions
1973 Common Report Var(flag_profile_reorder_functions)
1974 Enable function reordering that improves code placement.
1977 Common Var(common_deferred_options) Defer
1980 Common Joined RejectNegative Var(common_deferred_options) Defer
1981 -frandom-seed=<string> Make compile reproducible using <string>.
1983 ; This switch causes the command line that was used to create an
1984 ; object file to be recorded into the object file. The exact format
1985 ; of this recording is target and binary file format dependent.
1986 ; It is related to the -fverbose-asm switch, but that switch only
1987 ; records information in the assembler output file as comments, so
1988 ; they never reach the object file.
1989 frecord-gcc-switches
1990 Common Report Var(flag_record_gcc_switches)
1991 Record gcc command line switches in the object file.
1994 Common Report Var(flag_pcc_struct_return,0) Optimization
1995 Return small aggregates in registers.
1999 Does nothing. Preserved for backward compatibility.
2002 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2003 Tell DSE that the storage for a C++ object is dead when the constructor
2004 starts and when the destructor finishes.
2007 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization
2009 flive-range-shrinkage
2010 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2011 Relief of register pressure through live range shrinkage.
2014 Common Report Var(flag_rename_registers) Init(2) Optimization
2015 Perform a register renaming optimization pass.
2018 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2019 Perform a target dependent instruction fusion optimization pass.
2022 Common Report Var(flag_reorder_blocks) Optimization
2023 Reorder basic blocks to improve code placement.
2025 freorder-blocks-algorithm=
2026 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2027 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2030 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2033 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2036 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2038 freorder-blocks-and-partition
2039 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2040 Reorder basic blocks and partition into hot and cold sections.
2043 Common Report Var(flag_reorder_functions) Optimization
2044 Reorder functions to improve code placement.
2046 frerun-cse-after-loop
2047 Common Report Var(flag_rerun_cse_after_loop) Optimization
2048 Add a common subexpression elimination pass after loop optimizations.
2052 Does nothing. Preserved for backward compatibility.
2055 Common Report Var(flag_rounding_math) Optimization SetByCombined
2056 Disable optimizations that assume default FP rounding behavior.
2059 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2060 Enable scheduling across basic blocks.
2063 Common Report Var(flag_sched_pressure) Init(0) Optimization
2064 Enable register pressure sensitive insn scheduling.
2067 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2068 Allow speculative motion of non-loads.
2071 Common Report Var(flag_schedule_speculative_load) Optimization
2072 Allow speculative motion of some loads.
2074 fsched-spec-load-dangerous
2075 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2076 Allow speculative motion of more loads.
2079 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2080 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2082 fsched2-use-superblocks
2083 Common Report Var(flag_sched2_use_superblocks) Optimization
2084 If scheduling post reload, do superblock scheduling.
2088 Does nothing. Preserved for backward compatibility.
2091 Common Report Var(flag_schedule_insns) Optimization
2092 Reschedule instructions before register allocation.
2095 Common Report Var(flag_schedule_insns_after_reload) Optimization
2096 Reschedule instructions after register allocation.
2098 ; This flag should be on when a target implements non-trivial
2099 ; scheduling hooks, maybe saving some information for its own sake.
2100 ; On IA64, for example, this is used for correct bundling.
2101 fselective-scheduling
2102 Common Report Var(flag_selective_scheduling) Optimization
2103 Schedule instructions using selective scheduling algorithm.
2105 fselective-scheduling2
2106 Common Report Var(flag_selective_scheduling2) Optimization
2107 Run selective scheduling after reload.
2110 Common Undocumented Var(flag_self_test)
2113 fsel-sched-pipelining
2114 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2115 Perform software pipelining of inner loops during selective scheduling.
2117 fsel-sched-pipelining-outer-loops
2118 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2119 Perform software pipelining of outer loops during selective scheduling.
2121 fsel-sched-reschedule-pipelined
2122 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2123 Reschedule pipelined regions without pipelining.
2125 fsemantic-interposition
2126 Common Report Var(flag_semantic_interposition) Init(1)
2127 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2129 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2130 ; of stalled insns into the ready list.
2131 fsched-stalled-insns
2132 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2133 Allow premature scheduling of queued insns.
2135 fsched-stalled-insns=
2136 Common RejectNegative Joined UInteger Optimization
2137 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2139 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2140 ; be examined for a dependency on a stalled insn that is candidate for
2141 ; premature removal from the queue of stalled insns into the ready list (has
2142 ; an effect only if the flag 'sched_stalled_insns' is set).
2143 fsched-stalled-insns-dep
2144 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2145 Set dependence distance checking in premature scheduling of queued insns.
2147 fsched-stalled-insns-dep=
2148 Common RejectNegative Joined UInteger Optimization
2149 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2151 fsched-group-heuristic
2152 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2153 Enable the group heuristic in the scheduler.
2155 fsched-critical-path-heuristic
2156 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2157 Enable the critical path heuristic in the scheduler.
2159 fsched-spec-insn-heuristic
2160 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2161 Enable the speculative instruction heuristic in the scheduler.
2163 fsched-rank-heuristic
2164 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2165 Enable the rank heuristic in the scheduler.
2167 fsched-last-insn-heuristic
2168 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2169 Enable the last instruction heuristic in the scheduler.
2171 fsched-dep-count-heuristic
2172 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2173 Enable the dependent count heuristic in the scheduler.
2176 Common Report Var(flag_section_anchors) Optimization
2177 Access data in the same section from shared anchor points.
2181 Does nothing. Preserved for backward compatibility.
2185 Does nothing. Preserved for backward compatibility.
2188 Common Report Var(flag_ree) Init(0)
2189 Turn on Redundant Extensions Elimination pass.
2192 Common Report Var(flag_show_column) Init(1)
2193 Show column numbers in diagnostics, when available. Default on.
2196 Common Report Var(flag_shrink_wrap) Optimization
2197 Emit function prologues only before parts of the function that need it,
2198 rather than at the top of the function.
2201 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2202 Disable optimizations observable by IEEE signaling NaNs.
2205 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2206 Disable floating point optimizations that ignore the IEEE signedness of zero.
2208 fsingle-precision-constant
2209 Common Report Var(flag_single_precision_constant) Optimization
2210 Convert floating point constants to single precision constants.
2212 fsplit-ivs-in-unroller
2213 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2214 Split lifetimes of induction variables when loops are unrolled.
2217 Common Report Var(flag_split_stack) Init(-1)
2218 Generate discontiguous stack frames.
2221 Common Report Var(flag_split_wide_types) Optimization
2222 Split wide types into independent registers.
2225 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2226 Enable backward propagation of use properties at the SSA level.
2229 Common Report Var(flag_ssa_phiopt) Optimization
2230 Optimize conditional patterns using SSA PHI nodes.
2233 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2234 Optimize amount of stdarg registers saved to stack at start of function.
2236 fvariable-expansion-in-unroller
2237 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2238 Apply variable expansion when loops are unrolled.
2241 Common Report RejectNegative Joined
2242 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2245 Common Alias(fstack-check=, specific, no)
2246 Insert stack checking code into the program. Same as -fstack-check=specific.
2249 Common Var(common_deferred_options) Defer
2251 fstack-limit-register=
2252 Common RejectNegative Joined Var(common_deferred_options) Defer
2253 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2255 fstack-limit-symbol=
2256 Common RejectNegative Joined Var(common_deferred_options) Defer
2257 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2260 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2261 Use propolice as a stack protection method.
2263 fstack-protector-all
2264 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2265 Use a stack protection method for every function.
2267 fstack-protector-strong
2268 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2269 Use a smart stack protection method for certain functions.
2271 fstack-protector-explicit
2272 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2273 Use stack protection method only for functions with the stack_protect attribute.
2276 Common RejectNegative Var(flag_stack_usage)
2277 Output stack usage information on a per-function basis.
2281 Does nothing. Preserved for backward compatibility.
2283 ; Nonzero if we should do (language-dependent) alias analysis.
2284 ; Typically, this analysis will assume that expressions of certain
2285 ; types do not alias expressions of certain other types. Only used
2286 ; if alias analysis (in general) is enabled.
2288 Common Report Var(flag_strict_aliasing) Optimization
2289 Assume strict aliasing rules apply.
2292 Common Report Var(flag_strict_overflow) Optimization
2293 Treat signed overflow as undefined.
2296 Common Report Var(flag_sync_libcalls) Init(1)
2297 Implement __atomic operations via libcalls to legacy __sync functions.
2300 Common Report Var(flag_syntax_only)
2301 Check for syntax errors, then stop.
2304 Common Report Var(flag_test_coverage)
2305 Create data files needed by \"gcov\".
2308 Common Report Var(flag_thread_jumps) Optimization
2309 Perform jump threading optimizations.
2312 Common Report Var(time_report)
2313 Report the time taken by each compiler pass.
2315 ftime-report-details
2316 Common Report Var(time_report_details)
2317 Record times taken by sub-phases separately.
2320 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2321 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2324 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2327 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2330 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2333 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2336 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2339 Common Report Var(flag_toplevel_reorder) Init(2)
2340 Reorder top level functions, variables, and asms.
2343 Common Report Var(flag_tracer) Optimization
2344 Perform superblock formation via tail duplication.
2346 ; Zero means that floating-point math operations cannot generate a
2347 ; (user-visible) trap. This is the case, for example, in nonstop
2348 ; IEEE 754 arithmetic.
2350 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2351 Assume floating-point operations can trap.
2354 Common Report Var(flag_trapv) Optimization
2355 Trap for signed overflow in addition, subtraction and multiplication.
2358 Common Report Var(flag_tree_ccp) Optimization
2359 Enable SSA-CCP optimization on trees.
2362 Common Report Var(flag_tree_bit_ccp) Optimization
2363 Enable SSA-BIT-CCP optimization on trees.
2367 Does nothing. Preserved for backward compatibility.
2370 Common Report Var(flag_tree_ch) Optimization
2371 Enable loop header copying on trees.
2373 ftree-coalesce-inlined-vars
2374 Common Ignore RejectNegative
2375 Does nothing. Preserved for backward compatibility.
2378 Common Report Var(flag_tree_coalesce_vars) Optimization
2379 Enable SSA coalescing of user variables.
2383 Does nothing. Preserved for backward compatibility.
2386 Common Report Var(flag_tree_copy_prop) Optimization
2387 Enable copy propagation on trees.
2389 ftree-store-copy-prop
2391 Does nothing. Preserved for backward compatibility.
2394 Common Report Var(flag_tree_cselim) Init(2) Optimization
2395 Transform condition stores into unconditional ones.
2397 ftree-switch-conversion
2398 Common Report Var(flag_tree_switch_conversion) Optimization
2399 Perform conversions of switch initializations.
2402 Common Report Var(flag_tree_dce) Optimization
2403 Enable SSA dead code elimination optimization on trees.
2405 ftree-dominator-opts
2406 Common Report Var(flag_tree_dom) Optimization
2407 Enable dominator optimizations.
2410 Common Report Var(flag_tree_tail_merge) Optimization
2411 Enable tail merging on trees.
2414 Common Report Var(flag_tree_dse) Optimization
2415 Enable dead store elimination.
2418 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2419 Enable forward propagation on trees.
2422 Common Report Var(flag_tree_fre) Optimization
2423 Enable Full Redundancy Elimination (FRE) on trees.
2426 Common Report Var(flag_optimize_strlen) Optimization
2427 Enable string length optimizations on trees.
2429 fisolate-erroneous-paths-dereference
2430 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2431 Detect paths that trigger erroneous or undefined behavior due to
2432 dereferencing a null pointer. Isolate those paths from the main control
2433 flow and turn the statement with erroneous or undefined behavior into a trap.
2435 fisolate-erroneous-paths-attribute
2436 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2437 Detect paths that trigger erroneous or undefined behavior due a null value
2438 being used in a way forbidden by a returns_nonnull or nonnull
2439 attribute. Isolate those paths from the main control flow and turn the
2440 statement with erroneous or undefined behavior into a trap.
2442 ftree-loop-distribution
2443 Common Report Var(flag_tree_loop_distribution) Optimization
2444 Enable loop distribution on trees.
2446 ftree-loop-distribute-patterns
2447 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2448 Enable loop distribution for patterns transformed into a library call.
2451 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2452 Enable loop invariant motion on trees.
2455 Common Alias(floop-nest-optimize)
2456 Enable loop nest transforms. Same as -floop-nest-optimize.
2459 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2460 Create canonical induction variables in loops.
2463 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2464 Enable loop optimizations on tree level.
2466 ftree-parallelize-loops=
2467 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2468 Enable automatic parallelization of loops.
2471 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2472 Enable hoisting loads from conditional pointers.
2475 Common Report Var(flag_tree_pre) Optimization
2476 Enable SSA-PRE optimization on trees.
2479 Common Report Var(flag_tree_partial_pre) Optimization
2480 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2483 Common Report Var(flag_tree_pta) Optimization
2484 Perform function-local points-to analysis on trees.
2487 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2488 Enable reassociation on tree level.
2492 Does nothing. Preserved for backward compatibility.
2495 Common Report Var(flag_tree_sink) Optimization
2496 Enable SSA code sinking on trees.
2499 Common Report Var(flag_tree_slsr) Optimization
2500 Perform straight-line strength reduction.
2503 Common Report Var(flag_tree_sra) Optimization
2504 Perform scalar replacement of aggregates.
2507 Common Report Var(flag_tree_ter) Optimization
2508 Replace temporary expressions in the SSA->normal pass.
2511 Common Report Var(flag_tree_live_range_split) Optimization
2512 Perform live range splitting during the SSA->normal pass.
2515 Common Report Var(flag_tree_vrp) Init(0) Optimization
2516 Perform Value Range Propagation on trees.
2519 Common Report Var(flag_split_paths) Init(0) Optimization
2520 Split paths leading to loop backedges.
2522 funconstrained-commons
2523 Common Var(flag_unconstrained_commons) Optimization
2524 Assume common declarations may be overridden with ones with a larger
2528 Common Report Var(flag_unit_at_a_time) Init(1)
2529 Compile whole compilation unit at a time.
2532 Common Report Var(flag_unroll_loops) Optimization
2533 Perform loop unrolling when iteration count is known.
2536 Common Report Var(flag_unroll_all_loops) Optimization
2537 Perform loop unrolling for all loops.
2539 ; Nonzero means that loop optimizer may assume that the induction variables
2540 ; that control loops do not overflow and that the loops with nontrivial
2541 ; exit condition are not infinite
2542 funsafe-loop-optimizations
2544 Does nothing. Preserved for backward compatibility.
2547 Common Report Var(flag_associative_math) SetByCombined Optimization
2548 Allow optimization for floating-point arithmetic which may change the
2549 result of the operation due to rounding.
2552 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2553 Same as -fassociative-math for expressions which include division.
2555 ; Nonzero means that unsafe floating-point math optimizations are allowed
2556 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2557 ; are allowed to assume that their arguments and results are "normal"
2558 ; (e.g., nonnegative for SQRT).
2559 funsafe-math-optimizations
2560 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2561 Allow math optimizations that may violate IEEE or ISO standards.
2564 Common Report Var(flag_unswitch_loops) Optimization
2565 Perform loop unswitching.
2568 Common Report Var(flag_unwind_tables) Optimization
2569 Just generate unwind tables for exception handling.
2572 Common Driver Negative(fuse-ld=gold)
2573 Use the bfd linker instead of the default linker.
2576 Common Driver Negative(fuse-ld=bfd)
2577 Use the gold linker instead of the default linker.
2580 Common Undocumented Var(flag_use_linker_plugin)
2582 ; Positive if we should track variables, negative if we should run
2583 ; the var-tracking pass only to discard debug annotations, zero if
2584 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2585 ; will be set according to optimize, debug_info_level and debug_hooks
2586 ; in process_options ().
2588 Common Report Var(flag_var_tracking) Init(2) Optimization
2589 Perform variable tracking.
2591 ; Positive if we should track variables at assignments, negative if
2592 ; we should run the var-tracking pass only to discard debug
2593 ; annotations. When flag_var_tracking_assignments ==
2594 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2595 fvar-tracking-assignments
2596 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2597 Perform variable tracking by annotating assignments.
2599 ; Nonzero if we should toggle flag_var_tracking_assignments after
2600 ; processing options and computing its default. */
2601 fvar-tracking-assignments-toggle
2602 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2603 Toggle -fvar-tracking-assignments.
2605 ; Positive if we should track uninitialized variables, negative if
2606 ; we should run the var-tracking pass only to discard debug
2607 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2608 ; will be set according to flag_var_tracking.
2609 fvar-tracking-uninit
2610 Common Report Var(flag_var_tracking_uninit) Optimization
2611 Perform variable tracking and also tag variables that are uninitialized.
2614 Common Report Var(flag_tree_vectorize) Optimization
2615 Enable vectorization on trees.
2617 ftree-vectorizer-verbose=
2618 Common Joined RejectNegative Ignore
2619 Does nothing. Preserved for backward compatibility.
2621 ftree-loop-vectorize
2622 Common Report Var(flag_tree_loop_vectorize) Optimization
2623 Enable loop vectorization on trees.
2626 Common Report Var(flag_tree_slp_vectorize) Optimization
2627 Enable basic block vectorization (SLP) on trees.
2630 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2631 Specifies the cost model for vectorization.
2634 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2635 Specifies the vectorization cost model for code marked with a simd directive.
2638 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2641 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2644 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2647 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2650 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2651 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2654 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2655 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2657 ftree-vect-loop-version
2659 Does nothing. Preserved for backward compatibility.
2662 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2663 Enable copy propagation of scalar-evolution information.
2665 ; -fverbose-asm causes extra commentary information to be produced in
2666 ; the generated assembly code (to make it more readable). This option
2667 ; is generally only of use to those who actually need to read the
2668 ; generated assembly code (perhaps while debugging the compiler itself).
2669 ; -fno-verbose-asm, the default, causes the extra information
2670 ; to not be added and is useful when comparing two assembler files.
2672 Common Report Var(flag_verbose_asm)
2673 Add extra commentary to assembler output.
2676 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2677 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2680 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2683 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2686 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2689 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2692 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2695 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2696 Validate vtable pointers before using them.
2699 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2702 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2705 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2708 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2711 Common Var(flag_vtv_counts)
2712 Output vtable verification counters.
2715 Common Var(flag_vtv_debug)
2716 Output vtable verification pointer sets information.
2719 Common Report Var(flag_value_profile_transformations) Optimization
2720 Use expression value profiles in optimizations.
2723 Common Report Var(flag_web) Init(2) Optimization
2724 Construct webs and split unrelated uses of single variable.
2726 ftree-builtin-call-dce
2727 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2728 Enable conditional dead code elimination for builtin calls.
2731 Common Report Var(flag_whole_program) Init(0)
2732 Perform whole program optimizations.
2735 Common Report Var(flag_wrapv) Optimization
2736 Assume signed arithmetic overflow wraps around.
2738 fzero-initialized-in-bss
2739 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2740 Put zero initialized data in the bss section.
2743 Common JoinedOrMissing
2744 Generate debug information in default format.
2747 Common JoinedOrMissing Negative(gdwarf)
2748 Generate debug information in COFF format.
2751 Common JoinedOrMissing Negative(gdwarf-)
2752 Generate debug information in default version of DWARF format.
2755 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2756 Generate debug information in DWARF v2 (or later) format.
2759 Common JoinedOrMissing
2760 Generate debug information in default extended format.
2763 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2764 Don't generate DWARF pubnames and pubtypes sections.
2767 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2768 Generate DWARF pubnames and pubtypes sections.
2771 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2772 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2774 gno-record-gcc-switches
2775 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2776 Don't record gcc command line switches in DWARF DW_AT_producer.
2778 grecord-gcc-switches
2779 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2780 Record gcc command line switches in DWARF DW_AT_producer.
2783 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2784 Don't generate debug information in separate .dwo files.
2787 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2788 Generate debug information in separate .dwo files.
2791 Common JoinedOrMissing Negative(gstabs+)
2792 Generate debug information in STABS format.
2795 Common JoinedOrMissing Negative(gvms)
2796 Generate debug information in extended STABS format.
2799 Common RejectNegative Var(dwarf_strict,0) Init(0)
2800 Emit DWARF additions beyond selected version.
2803 Common Report RejectNegative Var(dwarf_strict,1)
2804 Don't emit DWARF additions beyond selected version.
2807 Common Report Var(flag_gtoggle)
2808 Toggle debug information generation.
2811 Common JoinedOrMissing Negative(gxcoff)
2812 Generate debug information in VMS format.
2815 Common JoinedOrMissing Negative(gxcoff+)
2816 Generate debug information in XCOFF format.
2819 Common JoinedOrMissing Negative(gcoff)
2820 Generate debug information in extended XCOFF format.
2823 Name(compressed_debug_sections) Type(int)
2825 ; Since -gz= is completely handled in specs, the values aren't used and we
2826 ; assign arbitrary constants.
2828 Enum(compressed_debug_sections) String(none) Value(0)
2831 Enum(compressed_debug_sections) String(zlib) Value(1)
2834 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2838 Generate compressed debug sections.
2841 Common Driver Joined Enum(compressed_debug_sections)
2842 -gz=<format> Generate compressed debug sections in format <format>.
2845 Driver Joined Separate
2848 Common Joined Var(plugindir_string) Init(0)
2849 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2852 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2853 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2856 Driver Joined Separate
2861 no-canonical-prefixes
2874 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2875 -o <file> Place output into <file>.
2878 Common Var(profile_flag)
2879 Enable function profiling.
2882 Driver Var(pass_exit_codes)
2885 Common Alias(Wpedantic)
2888 Common Var(flag_pedantic_errors)
2889 Like -pedantic but issue them as errors.
2895 Driver Var(use_pipes)
2898 Driver JoinedOrMissing Var(print_file_name)
2900 print-libgcc-file-name
2903 print-multi-directory
2904 Driver Var(print_multi_directory)
2907 Driver Var(print_multi_lib)
2909 print-multi-os-directory
2910 Driver Var(print_multi_os_directory)
2913 Driver Var(print_multiarch)
2916 Driver JoinedOrMissing Var(print_prog_name)
2919 Driver Var(print_search_dirs)
2922 Driver Var(print_sysroot)
2924 print-sysroot-headers-suffix
2925 Driver Var(print_sysroot_headers_suffix)
2928 Common Var(quiet_flag) RejectDriver
2929 Do not display functions compiled or elapsed time.
2947 Driver Var(report_times)
2950 Driver JoinedOrMissing
2953 Driver Joined Separate
2957 ; C option, but driver must not handle as "-u ndef".
2960 Common Driver Var(verbose_flag)
2961 Enable verbose output.
2964 Common Var(version_flag) RejectDriver
2965 Display the compiler's version.
2968 Common Var(inhibit_warnings)
2972 Driver Separate Var(wrapper_string)
2975 Driver Joined Separate
2978 Driver RejectNegative Negative(pie)
2979 Create a shared library.
2985 Driver Separate Alias(specs=)
2998 ; Documented for Fortran, but always accepted by driver.
3005 ; Documented for Go, but always accepted by driver.
3023 Driver RejectNegative Negative(shared)
3024 Don't create a position independent executable.
3027 Driver RejectNegative Negative(no-pie)
3028 Create a position independent executable.
3031 Driver Joined Separate
3034 Common Report Var(flag_ipa_ra) Optimization
3035 Use caller save register across calls if possible.
3037 ; This comment is to ensure we retain the blank line above.