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
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.
605 Common Var(warn_inline) Warning
606 Warn when an inlined function cannot be inlined.
608 Winvalid-memory-model
609 Common Var(warn_invalid_memory_model) Init(1) Warning
610 Warn when an atomic memory model parameter is known to be outside the valid range.
613 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
616 Common RejectNegative Joined UInteger Warning
617 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
620 Var(warn_nonnull_compare) Warning
621 Warn if comparing pointer parameter with nonnull attribute with NULL.
624 Common Var(warn_null_dereference) Warning
625 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
627 Wunsafe-loop-optimizations
628 Common Var(warn_unsafe_loop_optimizations) Warning
629 Warn if the loop cannot be optimized due to nontrivial assumptions.
632 Common Warning Alias(Wsuggest-attribute=noreturn)
635 Common Var(warn_odr_violations) Init(1) Warning
636 Warn about some C++ One Definition Rule violations during link time optimization.
639 Common Var(warn_overflow) Init(1) Warning
640 Warn about overflow in arithmetic expressions.
643 Common Var(warn_lto_type_mismatch) Init(1) Warning
644 During link time optimization warn about mismatched types of global declarations.
647 Common Var(warn_packed) Warning
648 Warn when the packed attribute has no effect on struct layout.
651 Common Var(warn_padded) Warning
652 Warn when padding is required to align structure members.
655 Common Var(pedantic) Init(0) Warning
656 Issue warnings needed for strict compliance to the standard.
659 Common Var(warn_return_local_addr) Init(1) Warning
660 Warn about returning a pointer/reference to a local or temporary variable.
663 Common Var(warn_shadow) Warning
664 Warn when one local variable shadows another.
667 Common Var(warn_stack_protect) Warning
668 Warn when not issuing stack smashing protection for some reason.
671 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
672 Warn if stack usage might be larger than specified amount.
676 Warn about code which might break strict aliasing rules.
679 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
680 Warn about code which might break strict aliasing rules.
684 Warn about optimizations that assume that signed overflow is undefined.
687 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
688 Warn about optimizations that assume that signed overflow is undefined.
690 Wsuggest-attribute=const
691 Common Var(warn_suggest_attribute_const) Warning
692 Warn about functions which might be candidates for __attribute__((const)).
694 Wsuggest-attribute=pure
695 Common Var(warn_suggest_attribute_pure) Warning
696 Warn about functions which might be candidates for __attribute__((pure)).
698 Wsuggest-attribute=noreturn
699 Common Var(warn_suggest_attribute_noreturn) Warning
700 Warn about functions which might be candidates for __attribute__((noreturn)).
703 Common Var(warn_suggest_final_types) Warning
704 Warn about C++ polymorphic types where adding final keyword would improve code quality.
706 Wsuggest-final-methods
707 Common Var(warn_suggest_final_methods) Warning
708 Warn about C++ virtual methods where adding final keyword would improve code quality.
711 Common Var(warn_switch_unreachable) Warning Init(1)
712 Warn about statements between switch's controlling expression and the first
716 Common Var(warn_system_headers) Warning
717 Do not suppress warnings from system headers.
720 Common Var(warn_trampolines) Warning
721 Warn whenever a trampoline is generated.
724 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
725 Warn if a comparison is always true or always false due to the limited range of the data type.
728 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
729 Warn about uninitialized automatic variables.
732 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
733 Warn about maybe uninitialized automatic variables.
736 Common Ignore Warning
737 Does nothing. Preserved for backward compatibility.
740 Common Var(warn_unused) Init(0) Warning
741 Enable all -Wunused- warnings.
743 Wunused-but-set-parameter
744 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
745 Warn when a function parameter is only set, otherwise unused.
747 Wunused-but-set-variable
748 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
749 Warn when a variable is only set, otherwise unused.
752 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
753 Warn when a function is unused.
756 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
757 Warn when a label is unused.
760 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
761 Warn when a function parameter is unused.
764 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
765 Warn when an expression value is unused.
768 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
769 Warn when a variable is unused.
772 Common Var(warn_coverage_mismatch) Init(1) Warning
773 Warn in case profiles in -fprofile-use do not match.
775 Wvector-operation-performance
776 Common Var(warn_vector_operation_performance) Warning
777 Warn when a vector operation is compiled outside the SIMD.
792 Common Separate Var(aux_info_file_name)
793 -aux-info <file> Emit declaration information into <file>.
796 Common Joined Alias(aux-info)
799 Common Separate RejectDriver Var(aux_base_name)
802 Common Separate RejectDriver
812 -d<letters> Enable dumps from specific passes of the compiler.
815 Common Separate Var(dump_base_name)
816 -dumpbase <file> Set the file basename to be used for dumps.
819 Common Separate Var(dump_dir_name)
820 -dumpdir <dir> Set the directory name to be used for dumps.
832 Driver Joined Separate
834 ; This option has historically been passed down to the linker by an
835 ; accident of a %{e*} spec, so ensure it continues to be passed down
836 ; as a single option. The supported option for this purpose is
837 ; -rdynamic. See PR 47390.
841 ; The version of the C++ ABI in use. The following values are allowed:
843 ; 0: The version of the ABI believed most conformant with the C++ ABI
844 ; specification. This ABI may change as bugs are discovered and fixed.
845 ; Therefore, 0 will not necessarily indicate the same ABI in different
848 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
850 ; 2: The version of the ABI first used in G++ 3.4, and the default
853 ; 3: The version of the ABI that fixes the missing underscore
854 ; in template non-type arguments of pointer type.
856 ; 4: The version of the ABI that introduces unambiguous mangling of
857 ; vector types. First selectable in G++ 4.5.
859 ; 5: The version of the ABI that ignores attribute const/noreturn
860 ; in function pointer mangling, and corrects mangling of decltype and
861 ; function parameters used in other parameters and the return type.
862 ; First selectable in G++ 4.6.
864 ; 6: The version of the ABI that doesn't promote scoped enums to int and
865 ; changes the mangling of template argument packs, const/static_cast,
866 ; prefix ++ and --, and a class scope function used as a template
868 ; First selectable in G++ 4.7.
870 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
871 ; corrects the mangling of lambdas in default argument scope.
872 ; First selectable in G++ 4.8.
874 ; 8: The version of the ABI that corrects the substitution behavior of
875 ; function types with function-cv-qualifiers.
876 ; First selectable in G++ 4.9 and default in G++ 5.
878 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
879 ; First selectable and default in G++ 5.2.
881 ; 10: The version of the ABI that mangles attributes that affect type
882 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
883 ; Default in G++ 6 (set in c_common_post_options).
885 ; 11: The version of the ABI that corrects mangling of sizeof... expressions.
888 ; Additional positive integers will be assigned as new versions of
889 ; the ABI become the default version of the ABI.
891 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
892 The version of the C++ ABI in use.
894 faggressive-loop-optimizations
895 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
896 Aggressively optimize loops using language constraints.
899 Common Report Var(align_functions,0) Optimization UInteger
900 Align the start of functions.
903 Common RejectNegative Joined UInteger Var(align_functions)
906 Common Report Var(align_jumps,0) Optimization UInteger
907 Align labels which are only reached by jumping.
910 Common RejectNegative Joined UInteger Var(align_jumps)
913 Common Report Var(align_labels,0) Optimization UInteger
917 Common RejectNegative Joined UInteger Var(align_labels)
920 Common Report Var(align_loops,0) Optimization UInteger
921 Align the start of loops.
924 Common RejectNegative Joined UInteger Var(align_loops)
928 Does nothing. Preserved for backward compatibility.
932 Does nothing. Preserved for backward compatibility.
934 fargument-noalias-global
936 Does nothing. Preserved for backward compatibility.
938 fargument-noalias-anything
940 Does nothing. Preserved for backward compatibility.
943 Common Driver Report Joined
944 Select what to sanitize.
947 Common Joined RejectNegative Var(common_deferred_options) Defer
948 -fasan-shadow-offset=<number> Use custom shadow memory offset.
951 Common Joined RejectNegative Var(common_deferred_options) Defer
952 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
953 in user-defined sections.
957 After diagnosing undefined behavior attempt to continue execution.
961 This switch is deprecated; use -fsanitize-recover= instead.
963 fsanitize-undefined-trap-on-error
964 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
965 Use trap instead of a library function for undefined behavior sanitization.
967 fasynchronous-unwind-tables
968 Common Report Var(flag_asynchronous_unwind_tables) Optimization
969 Generate unwind tables that are exact at each instruction boundary.
972 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
973 Generate auto-inc/dec instructions.
976 Common Report Var(flag_auto_profile)
977 Use sample profile information for call graph node weights. The default
978 profile file is fbdata.afdo in 'pwd'.
981 Common Joined RejectNegative Var(auto_profile_file)
982 Use sample profile information for call graph node weights. The profile
983 file is specified in the argument.
985 ; -fcheck-bounds causes gcc to generate array bounds checks.
986 ; For C, C++ and ObjC: defaults off.
987 ; For Java: defaults to on.
988 ; For Fortran: defaults to off.
990 Common Report Var(flag_bounds_check)
991 Generate code to check bounds before indexing arrays.
994 Common Report Var(flag_branch_on_count_reg) Optimization
995 Replace add, compare, branch with branch on count register.
997 fbranch-probabilities
998 Common Report Var(flag_branch_probabilities) Optimization
999 Use profiling information for branch probabilities.
1001 fbranch-target-load-optimize
1002 Common Report Var(flag_branch_target_load_optimize) Optimization
1003 Perform branch target load optimization before prologue / epilogue threading.
1005 fbranch-target-load-optimize2
1006 Common Report Var(flag_branch_target_load_optimize2) Optimization
1007 Perform branch target load optimization after prologue / epilogue threading.
1010 Common Report Var(flag_btr_bb_exclusive) Optimization
1011 Restrict target load migration not to re-use registers in any basic block.
1014 Common Joined RejectNegative Var(common_deferred_options) Defer
1015 -fcall-saved-<register> Mark <register> as being preserved across functions.
1018 Common Joined RejectNegative Var(common_deferred_options) Defer
1019 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1021 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1022 ; be saved across function calls, if that produces overall better code.
1023 ; Optional now, so people can test it.
1025 Common Report Var(flag_caller_saves) Optimization
1026 Save registers around function calls.
1029 Common Report Var(flag_check_data_deps)
1030 This switch is deprecated; do not use.
1033 Common Var(flag_check_new)
1034 Check the return value of new in C++.
1037 Common Var(flag_checking) Init(CHECKING_P)
1038 Perform internal consistency checkings.
1041 Common Joined RejectNegative UInteger Var(flag_checking)
1042 Perform internal consistency checkings.
1045 Common Report Var(flag_code_hoisting) Optimization
1046 Enable code hoisting.
1048 fcombine-stack-adjustments
1049 Common Report Var(flag_combine_stack_adjustments) Optimization
1050 Looks for opportunities to reduce stack adjustments and stack references.
1053 Common Report Var(flag_no_common,0)
1054 Do not put uninitialized globals in the common section.
1058 ; Converted by the driver to -fcompare-debug= options.
1061 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1062 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1064 fcompare-debug-second
1065 Common Driver RejectNegative Var(flag_compare_debug)
1066 Run only the second compilation of -fcompare-debug.
1069 Common Report Var(flag_compare_elim_after_reload) Optimization
1070 Perform comparison elimination after register allocation has finished.
1073 Common Var(flag_conserve_stack) Optimization
1074 Do not perform optimizations increasing noticeably stack usage.
1077 Common Report Var(flag_cprop_registers) Optimization
1078 Perform a register copy-propagation optimization pass.
1081 Common Report Var(flag_crossjumping) Optimization
1082 Perform cross-jumping optimization.
1085 Common Report Var(flag_cse_follow_jumps) Optimization
1086 When running CSE, follow jumps to their targets.
1090 Does nothing. Preserved for backward compatibility.
1093 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1094 Omit range reduction step when performing complex division.
1097 Common Report Var(flag_cx_fortran_rules) Optimization
1098 Complex multiplication and division follow Fortran rules.
1101 Common Report Var(flag_data_sections)
1102 Place data items into their own section.
1105 Common Report Var(common_deferred_options) Defer
1106 List all available debugging counters with their limits and counts.
1109 Common RejectNegative Joined Var(common_deferred_options) Defer
1110 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1113 Common Joined RejectNegative Var(common_deferred_options) Defer
1114 Map one directory name to another in debug information.
1116 fdebug-types-section
1117 Common Report Var(flag_debug_types_section) Init(0)
1118 Output .debug_types section when using DWARF v4 debuginfo.
1120 ; Nonzero for -fdefer-pop: don't pop args after each function call
1121 ; instead save them up to pop many calls' args with one insns.
1123 Common Report Var(flag_defer_pop) Optimization
1124 Defer popping functions args from stack until later.
1127 Common Report Var(flag_delayed_branch) Optimization
1128 Attempt to fill delay slots of branch instructions.
1130 fdelete-dead-exceptions
1131 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1132 Delete dead instructions that may throw exceptions.
1134 fdelete-null-pointer-checks
1135 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1136 Delete useless null pointer checks.
1138 fdevirtualize-at-ltrans
1139 Common Report Var(flag_ltrans_devirtualize)
1140 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1142 fdevirtualize-speculatively
1143 Common Report Var(flag_devirtualize_speculatively) Optimization
1144 Perform speculative devirtualization.
1147 Common Report Var(flag_devirtualize) Optimization
1148 Try to convert virtual calls to direct ones.
1150 fdiagnostics-show-location=
1151 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1152 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1154 ; Required for these enum values.
1159 Name(diagnostic_prefixing_rule) Type(int)
1162 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1165 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1167 fdiagnostics-show-caret
1168 Common Var(flag_diagnostics_show_caret) Init(1)
1169 Show the source line with a caret indicating the column.
1172 Common Alias(fdiagnostics-color=,always,never)
1176 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1177 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1179 ; Required for these enum values.
1184 Name(diagnostic_color_rule) Type(int)
1187 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1190 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1193 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1195 fdiagnostics-parseable-fixits
1196 Common Var(flag_diagnostics_parseable_fixits)
1197 Print fixit hints in machine-readable form.
1199 fdiagnostics-generate-patch
1200 Common Var(flag_diagnostics_generate_patch)
1201 Print fix-it hints to stderr in unified diff format.
1203 fdiagnostics-show-option
1204 Common Var(flag_diagnostics_show_option) Init(1)
1205 Amend appropriate diagnostic messages with the command line option that controls them.
1208 Common Joined RejectNegative Var(common_deferred_options) Defer
1209 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1212 Common Joined RejectNegative Var(common_deferred_options) Defer
1213 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1216 Common Joined RejectNegative Var(common_deferred_options) Defer
1217 -fdump-<type> Dump various compiler internals to a file.
1220 Driver RejectNegative
1223 Common RejectNegative Joined Var(flag_dump_final_insns)
1224 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1227 Common RejectNegative Joined Var(flag_dump_go_spec)
1228 -fdump-go-spec=filename Write all declarations to file as Go code.
1231 Common Report Var(flag_dump_noaddr)
1232 Suppress output of addresses in debugging dumps.
1235 Common Driver Var(flag_report_bug)
1236 Collect and dump debug information into temporary file if ICE in C/C++
1239 fdump-internal-locations
1240 Common Var(flag_dump_locations) Init(0)
1241 Dump detailed information on GCC's internal representation of source code locations.
1244 Common Var(flag_dump_passes) Init(0)
1245 Dump optimization passes.
1248 Common Report Var(flag_dump_unnumbered)
1249 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1251 fdump-unnumbered-links
1252 Common Report Var(flag_dump_unnumbered_links)
1253 Suppress output of previous and next insn numbers in debugging dumps.
1256 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1257 Enable CFI tables via GAS assembler directives.
1260 Common Report Var(flag_early_inlining) Init(1) Optimization
1261 Perform early inlining.
1263 feliminate-dwarf2-dups
1264 Common Report Var(flag_eliminate_dwarf2_dups)
1265 Perform DWARF duplicate elimination.
1268 Common Report Var(flag_ipa_sra) Init(0) Optimization
1269 Perform interprocedural reduction of aggregates.
1271 feliminate-unused-debug-symbols
1272 Common Report Var(flag_debug_only_used_symbols)
1273 Perform unused symbol elimination in debug info.
1275 feliminate-unused-debug-types
1276 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1277 Perform unused type elimination in debug info.
1279 femit-class-debug-always
1280 Common Report Var(flag_emit_class_debug_always) Init(0)
1281 Do not suppress C++ class debug information.
1284 Common Report Var(flag_exceptions) Optimization
1285 Enable exception handling.
1287 fexpensive-optimizations
1288 Common Report Var(flag_expensive_optimizations) Optimization
1289 Perform a number of minor, expensive optimizations.
1292 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1293 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1296 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1299 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1302 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1308 Common Var(flag_fat_lto_objects)
1309 Output lto objects containing both the intermediate language and binary output.
1312 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1313 Assume no NaNs or infinities are generated.
1316 Common Joined RejectNegative Var(common_deferred_options) Defer
1317 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1320 Common Report Var(flag_float_store) Optimization
1321 Don't allocate floats and doubles in extended-precision registers.
1325 Does nothing. Preserved for backward compatibility.
1328 Common Report Var(flag_forward_propagate) Optimization
1329 Perform a forward propagation pass on RTL.
1332 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1333 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1336 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1339 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1341 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1343 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1346 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1348 ffp-int-builtin-inexact
1349 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1350 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1352 ; Nonzero means don't put addresses of constant functions in registers.
1353 ; Used for compiling the Unix kernel, where strange substitutions are
1354 ; done on the assembly output.
1356 Common Report Var(flag_no_function_cse,0) Optimization
1357 Allow function addresses to be held in registers.
1360 Common Report Var(flag_function_sections)
1361 Place each function into its own section.
1364 Common Report Var(flag_gcse) Optimization
1365 Perform global common subexpression elimination.
1368 Common Report Var(flag_gcse_lm) Init(1) Optimization
1369 Perform enhanced load motion during global common subexpression elimination.
1372 Common Report Var(flag_gcse_sm) Init(0) Optimization
1373 Perform store motion after global common subexpression elimination.
1376 Common Report Var(flag_gcse_las) Init(0) Optimization
1377 Perform redundant load after store elimination in global common subexpression
1381 Common Report Var(flag_gcse_after_reload) Optimization
1382 Perform global common subexpression elimination after register allocation has
1386 Name(dwarf_gnat_encodings) Type(int)
1389 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1392 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1395 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1398 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1399 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1401 ; This option is not documented yet as its semantics will change.
1403 Common Report Var(flag_graphite) Optimization
1404 Enable in and out of Graphite representation.
1407 Common Report Var(flag_graphite_identity) Optimization
1408 Enable Graphite Identity transformation.
1410 fhoist-adjacent-loads
1411 Common Report Var(flag_hoist_adjacent_loads) Optimization
1412 Enable hoisting adjacent loads to encourage generating conditional move
1416 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1417 ; Always keep a pointer to a live memory block
1419 floop-parallelize-all
1420 Common Report Var(flag_loop_parallelize_all) Optimization
1421 Mark all loops as parallel.
1424 Common Alias(floop-nest-optimize)
1425 Enable loop nest transforms. Same as -floop-nest-optimize.
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.
1435 floop-unroll-and-jam
1436 Common Alias(floop-nest-optimize)
1437 Enable loop nest transforms. Same as -floop-nest-optimize.
1440 Common Report Var(flag_tm)
1441 Enable support for GNU transactional memory.
1444 Common Report Var(flag_gnu_unique) Init(1)
1445 Use STB_GNU_UNIQUE if supported by the assembler.
1449 Does nothing. Preserved for backward compatibility.
1452 Common Report Var(flag_loop_nest_optimize) Optimization
1453 Enable the loop nest optimizer.
1455 fstrict-volatile-bitfields
1456 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1457 Force bitfield accesses to match their type width.
1459 fguess-branch-probability
1460 Common Report Var(flag_guess_branch_prob) Optimization
1461 Enable guessing of branch probabilities.
1463 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1464 ; Generate position-independent code for executables if possible
1465 ; On SVR4 targets, it also controls whether or not to emit a
1466 ; string identifying the compiler.
1468 Common Report Var(flag_no_ident,0)
1469 Process #ident directives.
1472 Common Report Var(flag_if_conversion) Optimization
1473 Perform conversion of conditional jumps to branchless equivalents.
1476 Common Report Var(flag_if_conversion2) Optimization
1477 Perform conversion of conditional jumps to conditional execution.
1480 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1481 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1484 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1487 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1490 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1493 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1495 ftree-loop-if-convert
1496 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1497 Convert conditional jumps in innermost loops to branchless equivalents.
1499 ftree-loop-if-convert-stores
1500 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1501 Also if-convert conditional jumps containing memory writes.
1503 ; -finhibit-size-directive inhibits output of .size for ELF.
1504 ; This is used only for compiling crtstuff.c,
1505 ; and it may be extended to other effects
1506 ; needed for crtstuff.c on other systems.
1507 finhibit-size-directive
1508 Common Report Var(flag_inhibit_size_directive)
1509 Do not generate .size directives.
1512 Common Report Var(flag_indirect_inlining) Optimization
1513 Perform indirect inlining.
1515 ; General flag to enable inlining. Specifying -fno-inline will disable
1516 ; all inlining apart from always-inline functions.
1518 Common Report Var(flag_no_inline,0) Init(0) Optimization
1519 Enable inlining of function declared \"inline\", disabling disables all inlining.
1521 finline-small-functions
1522 Common Report Var(flag_inline_small_functions) Optimization
1523 Integrate functions into their callers when code size is known not to grow.
1526 Common Report Var(flag_inline_functions) Optimization
1527 Integrate functions not declared \"inline\" into their callers when profitable.
1529 finline-functions-called-once
1530 Common Report Var(flag_inline_functions_called_once) Optimization
1531 Integrate functions only required by their single caller.
1534 Common RejectNegative Joined Alias(finline-limit=)
1537 Common RejectNegative Joined UInteger
1538 -finline-limit=<number> Limit the size of inlined functions to <number>.
1541 Common Report Var(flag_inline_atomics) Init(1) Optimization
1542 Inline __atomic operations when a lock free instruction sequence is available.
1544 finstrument-functions
1545 Common Report Var(flag_instrument_function_entry_exit)
1546 Instrument function entry and exit with profiling calls.
1548 finstrument-functions-exclude-function-list=
1549 Common RejectNegative Joined
1550 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1552 finstrument-functions-exclude-file-list=
1553 Common RejectNegative Joined
1554 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1557 Common Report Var(flag_ipa_cp) Optimization
1558 Perform interprocedural constant propagation.
1561 Common Report Var(flag_ipa_cp_clone) Optimization
1562 Perform cloning to make Interprocedural constant propagation stronger.
1565 Common Report Var(flag_ipa_cp_alignment) Optimization
1566 Perform alignment discovery and propagation to make Interprocedural constant propagation stronger.
1569 Common Report Var(flag_ipa_bit_cp) Optimization
1570 Perform interprocedural bitwise constant propagation.
1573 Common Report Var(flag_ipa_profile) Init(0) Optimization
1574 Perform interprocedural profile propagation.
1577 Common Report Var(flag_ipa_pta) Init(0) Optimization
1578 Perform interprocedural points-to analysis.
1581 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1582 Discover pure and const functions.
1585 Common Report Var(flag_ipa_icf) Optimization
1586 Perform Identical Code Folding for functions and read-only variables.
1589 Common Report Var(flag_ipa_icf_functions) Optimization
1590 Perform Identical Code Folding for functions.
1593 Common Report Var(flag_ipa_icf_variables)
1594 Perform Identical Code Folding for variables.
1597 Common Report Var(flag_ipa_reference) Init(0) Optimization
1598 Discover readonly and non addressable static variables.
1602 Does nothing. Preserved for backward compatibility.
1606 Does nothing. Preserved for backward compatibility.
1609 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1610 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1613 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1616 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1619 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1622 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1623 -fira-region=[one|all|mixed] Set regions for IRA.
1626 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1629 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1632 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1635 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1638 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1639 Use IRA based register pressure calculation
1640 in RTL hoist optimizations.
1643 Common Report Var(flag_ira_loop_pressure) Optimization
1644 Use IRA based register pressure calculation
1645 in RTL loop optimizations.
1647 fira-share-save-slots
1648 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1649 Share slots for saving different hard registers.
1651 fira-share-spill-slots
1652 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1653 Share stack slots for spilled pseudo-registers.
1656 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1657 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1660 Common Report Var(flag_ivopts) Init(1) Optimization
1661 Optimize induction variables on trees.
1664 Common Var(flag_jump_tables) Init(1) Optimization
1665 Use jump tables for sufficiently large switch statements.
1667 fkeep-inline-functions
1668 Common Report Var(flag_keep_inline_functions)
1669 Generate code for functions even if they are fully inlined.
1671 fkeep-static-functions
1672 Common Report Var(flag_keep_static_functions)
1673 Generate code for static functions even if they are never called.
1676 Common Report Var(flag_keep_static_consts) Init(1)
1677 Emit static const variables even if they are not used.
1680 Common Report Var(flag_leading_underscore) Init(-1)
1681 Give external symbols a leading underscore.
1685 Does nothing. Preserved for backward compatibility.
1688 Common Report Var(flag_lra_remat) Optimization
1689 Do CFG-sensitive rematerialization in LRA.
1693 Enable link-time optimization.
1696 Common RejectNegative Joined Var(flag_lto)
1697 Link-time optimization with number of parallel jobs or jobserver.
1700 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1703 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1706 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1709 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1712 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1715 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1718 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1719 Specify the algorithm to partition symbols and vars at linktime.
1721 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1722 flto-compression-level=
1723 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1724 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1726 flto-odr-type-merging
1727 Common Report Var(flag_lto_odr_type_mering) Init(1)
1728 Merge C++ types using One Definition Rule.
1731 Common Report Var(flag_lto_report) Init(0)
1732 Report various link-time optimization statistics.
1735 Common Report Var(flag_lto_report_wpa) Init(0)
1736 Report various link-time optimization statistics for WPA only.
1739 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1740 Set errno after built-in math functions.
1743 Common Joined RejectNegative UInteger Var(flag_max_errors)
1744 -fmax-errors=<number> Maximum number of errors to report.
1747 Common Report Var(mem_report)
1748 Report on permanent memory allocation.
1751 Common Report Var(mem_report_wpa)
1752 Report on permanent memory allocation in WPA only.
1754 ; This will attempt to merge constant section constants, if 1 only
1755 ; string constants and constants from constant pool, if 2 also constant
1757 fmerge-all-constants
1758 Common Report Var(flag_merge_constants,2) Init(1)
1759 Attempt to merge identical constants and constant variables.
1762 Common Report Var(flag_merge_constants,1)
1763 Attempt to merge identical constants across compilation units.
1765 fmerge-debug-strings
1766 Common Report Var(flag_merge_debug_strings) Init(1)
1767 Attempt to merge identical debug strings across compilation units.
1770 Common RejectNegative Joined UInteger
1771 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1774 Common Report Var(flag_modulo_sched) Optimization
1775 Perform SMS based modulo scheduling before the first scheduling pass.
1777 fmodulo-sched-allow-regmoves
1778 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1779 Perform SMS based modulo scheduling with register moves allowed.
1781 fmove-loop-invariants
1782 Common Report Var(flag_move_loop_invariants) Optimization
1783 Move loop invariant computations out of loops.
1786 Common Var(flag_dce) Init(1) Optimization
1787 Use the RTL dead code elimination pass.
1790 Common Var(flag_dse) Init(1) Optimization
1791 Use the RTL dead store elimination pass.
1793 freschedule-modulo-scheduled-loops
1794 Common Report Var(flag_resched_modulo_sched) Optimization
1795 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1797 fnon-call-exceptions
1798 Common Report Var(flag_non_call_exceptions) Optimization
1799 Support synchronous non-call exceptions.
1802 Common Driver Joined MissingArgError(options or targets missing after %qs)
1803 -foffload=<targets>=<options> Specify offloading targets and options for them.
1806 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1807 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1810 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1813 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1816 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1819 Common Report Var(flag_omit_frame_pointer) Optimization
1820 When possible do not generate stack frames.
1823 Common Report Var(flag_opt_info) Optimization
1824 Enable all optimization info dumps on stderr.
1827 Common Joined RejectNegative Var(common_deferred_options) Defer
1828 -fopt-info[-<type>=filename] Dump compiler optimization details.
1830 foptimize-register-move
1832 Does nothing. Preserved for backward compatibility.
1834 foptimize-sibling-calls
1835 Common Report Var(flag_optimize_sibling_calls) Optimization
1836 Optimize sibling and tail recursive calls.
1839 Common Report Var(flag_partial_inlining) Optimization
1840 Perform partial inlining.
1843 Common Report Var(pre_ipa_mem_report)
1844 Report on memory allocation before interprocedural optimization.
1846 fpost-ipa-mem-report
1847 Common Report Var(post_ipa_mem_report)
1848 Report on memory allocation before interprocedural optimization.
1851 Common Report Var(flag_pack_struct) Optimization
1852 Pack structure members together without holes.
1855 Common RejectNegative Joined UInteger Optimization
1856 -fpack-struct=<number> Set initial maximum structure member alignment.
1859 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1860 Return small aggregates in memory, not registers.
1863 Common Report Var(flag_peel_loops) Optimization
1864 Perform loop peeling.
1867 Common Report Var(flag_no_peephole,0) Optimization
1868 Enable machine specific peephole optimizations.
1871 Common Report Var(flag_peephole2) Optimization
1872 Enable an RTL peephole pass before sched2.
1875 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1876 Generate position-independent code if possible (large mode).
1879 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1880 Generate position-independent code for executables if possible (large mode).
1883 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1884 Generate position-independent code if possible (small mode).
1887 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1888 Generate position-independent code for executables if possible (small mode).
1891 Common Report Var(flag_plt) Init(1) Optimization
1892 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
1895 Common Joined RejectNegative Var(common_deferred_options) Defer
1896 Specify a plugin to load.
1899 Common Joined RejectNegative Var(common_deferred_options) Defer
1900 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
1902 fpredictive-commoning
1903 Common Report Var(flag_predictive_commoning) Optimization
1904 Run predictive commoning optimization.
1906 fprefetch-loop-arrays
1907 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1908 Generate prefetch instructions, if available, for arrays in loops.
1911 Common Report Var(profile_flag)
1912 Enable basic program profiling code.
1915 Common Report Var(profile_arc_flag)
1916 Insert arc-based program profiling code.
1919 Common Joined RejectNegative Var(profile_data_prefix)
1920 Set the top-level directory for storing the profile data.
1921 The default is 'pwd'.
1924 Common Report Var(flag_profile_correction)
1925 Enable correction of flow inconsistent profile data input.
1928 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
1929 -fprofile-update=[single|atomic] Set the profile update method.
1932 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
1935 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
1938 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
1942 Enable common options for generating profile info for profile feedback directed optimizations.
1945 Common Joined RejectNegative
1946 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
1949 Common Var(flag_profile_use)
1950 Enable common options for performing profile feedback directed optimizations.
1953 Common Joined RejectNegative
1954 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
1957 Common Report Var(flag_profile_values)
1958 Insert code to profile values of expressions.
1961 Common Report Var(profile_report)
1962 Report on consistency of profile.
1964 fprofile-reorder-functions
1965 Common Report Var(flag_profile_reorder_functions)
1966 Enable function reordering that improves code placement.
1969 Common Var(common_deferred_options) Defer
1972 Common Joined RejectNegative Var(common_deferred_options) Defer
1973 -frandom-seed=<string> Make compile reproducible using <string>.
1975 ; This switch causes the command line that was used to create an
1976 ; object file to be recorded into the object file. The exact format
1977 ; of this recording is target and binary file format dependent.
1978 ; It is related to the -fverbose-asm switch, but that switch only
1979 ; records information in the assembler output file as comments, so
1980 ; they never reach the object file.
1981 frecord-gcc-switches
1982 Common Report Var(flag_record_gcc_switches)
1983 Record gcc command line switches in the object file.
1986 Common Report Var(flag_pcc_struct_return,0) Optimization
1987 Return small aggregates in registers.
1991 Does nothing. Preserved for backward compatibility.
1994 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
1995 Tell DSE that the storage for a C++ object is dead when the constructor
1996 starts and when the destructor finishes.
1999 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization
2001 flive-range-shrinkage
2002 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2003 Relief of register pressure through live range shrinkage.
2006 Common Report Var(flag_rename_registers) Init(2) Optimization
2007 Perform a register renaming optimization pass.
2010 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2011 Perform a target dependent instruction fusion optimization pass.
2014 Common Report Var(flag_reorder_blocks) Optimization
2015 Reorder basic blocks to improve code placement.
2017 freorder-blocks-algorithm=
2018 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2019 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2022 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2025 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2028 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2030 freorder-blocks-and-partition
2031 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2032 Reorder basic blocks and partition into hot and cold sections.
2035 Common Report Var(flag_reorder_functions) Optimization
2036 Reorder functions to improve code placement.
2038 frerun-cse-after-loop
2039 Common Report Var(flag_rerun_cse_after_loop) Optimization
2040 Add a common subexpression elimination pass after loop optimizations.
2044 Does nothing. Preserved for backward compatibility.
2047 Common Report Var(flag_rounding_math) Optimization SetByCombined
2048 Disable optimizations that assume default FP rounding behavior.
2051 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2052 Enable scheduling across basic blocks.
2055 Common Report Var(flag_sched_pressure) Init(0) Optimization
2056 Enable register pressure sensitive insn scheduling.
2059 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2060 Allow speculative motion of non-loads.
2063 Common Report Var(flag_schedule_speculative_load) Optimization
2064 Allow speculative motion of some loads.
2066 fsched-spec-load-dangerous
2067 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2068 Allow speculative motion of more loads.
2071 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2072 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2074 fsched2-use-superblocks
2075 Common Report Var(flag_sched2_use_superblocks) Optimization
2076 If scheduling post reload, do superblock scheduling.
2080 Does nothing. Preserved for backward compatibility.
2083 Common Report Var(flag_schedule_insns) Optimization
2084 Reschedule instructions before register allocation.
2087 Common Report Var(flag_schedule_insns_after_reload) Optimization
2088 Reschedule instructions after register allocation.
2090 ; This flag should be on when a target implements non-trivial
2091 ; scheduling hooks, maybe saving some information for its own sake.
2092 ; On IA64, for example, this is used for correct bundling.
2093 fselective-scheduling
2094 Common Report Var(flag_selective_scheduling) Optimization
2095 Schedule instructions using selective scheduling algorithm.
2097 fselective-scheduling2
2098 Common Report Var(flag_selective_scheduling2) Optimization
2099 Run selective scheduling after reload.
2102 Common Undocumented Var(flag_self_test)
2105 fsel-sched-pipelining
2106 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2107 Perform software pipelining of inner loops during selective scheduling.
2109 fsel-sched-pipelining-outer-loops
2110 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2111 Perform software pipelining of outer loops during selective scheduling.
2113 fsel-sched-reschedule-pipelined
2114 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2115 Reschedule pipelined regions without pipelining.
2117 fsemantic-interposition
2118 Common Report Var(flag_semantic_interposition) Init(1)
2119 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2121 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2122 ; of stalled insns into the ready list.
2123 fsched-stalled-insns
2124 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2125 Allow premature scheduling of queued insns.
2127 fsched-stalled-insns=
2128 Common RejectNegative Joined UInteger Optimization
2129 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2131 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2132 ; be examined for a dependency on a stalled insn that is candidate for
2133 ; premature removal from the queue of stalled insns into the ready list (has
2134 ; an effect only if the flag 'sched_stalled_insns' is set).
2135 fsched-stalled-insns-dep
2136 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2137 Set dependence distance checking in premature scheduling of queued insns.
2139 fsched-stalled-insns-dep=
2140 Common RejectNegative Joined UInteger Optimization
2141 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2143 fsched-group-heuristic
2144 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2145 Enable the group heuristic in the scheduler.
2147 fsched-critical-path-heuristic
2148 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2149 Enable the critical path heuristic in the scheduler.
2151 fsched-spec-insn-heuristic
2152 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2153 Enable the speculative instruction heuristic in the scheduler.
2155 fsched-rank-heuristic
2156 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2157 Enable the rank heuristic in the scheduler.
2159 fsched-last-insn-heuristic
2160 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2161 Enable the last instruction heuristic in the scheduler.
2163 fsched-dep-count-heuristic
2164 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2165 Enable the dependent count heuristic in the scheduler.
2168 Common Report Var(flag_section_anchors) Optimization
2169 Access data in the same section from shared anchor points.
2173 Does nothing. Preserved for backward compatibility.
2177 Does nothing. Preserved for backward compatibility.
2180 Common Report Var(flag_ree) Init(0)
2181 Turn on Redundant Extensions Elimination pass.
2184 Common Report Var(flag_show_column) Init(1)
2185 Show column numbers in diagnostics, when available. Default on.
2188 Common Report Var(flag_shrink_wrap) Optimization
2189 Emit function prologues only before parts of the function that need it,
2190 rather than at the top of the function.
2193 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2194 Disable optimizations observable by IEEE signaling NaNs.
2197 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2198 Disable floating point optimizations that ignore the IEEE signedness of zero.
2200 fsingle-precision-constant
2201 Common Report Var(flag_single_precision_constant) Optimization
2202 Convert floating point constants to single precision constants.
2204 fsplit-ivs-in-unroller
2205 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2206 Split lifetimes of induction variables when loops are unrolled.
2209 Common Report Var(flag_split_stack) Init(-1)
2210 Generate discontiguous stack frames.
2213 Common Report Var(flag_split_wide_types) Optimization
2214 Split wide types into independent registers.
2217 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2218 Enable backward propagation of use properties at the SSA level.
2221 Common Report Var(flag_ssa_phiopt) Optimization
2222 Optimize conditional patterns using SSA PHI nodes.
2225 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2226 Optimize amount of stdarg registers saved to stack at start of function.
2228 fvariable-expansion-in-unroller
2229 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2230 Apply variable expansion when loops are unrolled.
2233 Common Report RejectNegative Joined
2234 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2237 Common Alias(fstack-check=, specific, no)
2238 Insert stack checking code into the program. Same as -fstack-check=specific.
2241 Common Var(common_deferred_options) Defer
2243 fstack-limit-register=
2244 Common RejectNegative Joined Var(common_deferred_options) Defer
2245 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2247 fstack-limit-symbol=
2248 Common RejectNegative Joined Var(common_deferred_options) Defer
2249 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2252 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2253 Use propolice as a stack protection method.
2255 fstack-protector-all
2256 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2257 Use a stack protection method for every function.
2259 fstack-protector-strong
2260 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2261 Use a smart stack protection method for certain functions.
2263 fstack-protector-explicit
2264 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2265 Use stack protection method only for functions with the stack_protect attribute.
2268 Common RejectNegative Var(flag_stack_usage)
2269 Output stack usage information on a per-function basis.
2273 Does nothing. Preserved for backward compatibility.
2275 ; Nonzero if we should do (language-dependent) alias analysis.
2276 ; Typically, this analysis will assume that expressions of certain
2277 ; types do not alias expressions of certain other types. Only used
2278 ; if alias analysis (in general) is enabled.
2280 Common Report Var(flag_strict_aliasing) Optimization
2281 Assume strict aliasing rules apply.
2284 Common Report Var(flag_strict_overflow) Optimization
2285 Treat signed overflow as undefined.
2288 Common Report Var(flag_sync_libcalls) Init(1)
2289 Implement __atomic operations via libcalls to legacy __sync functions.
2292 Common Report Var(flag_syntax_only)
2293 Check for syntax errors, then stop.
2296 Common Report Var(flag_test_coverage)
2297 Create data files needed by \"gcov\".
2300 Common Report Var(flag_thread_jumps) Optimization
2301 Perform jump threading optimizations.
2304 Common Report Var(time_report)
2305 Report the time taken by each compiler pass.
2307 ftime-report-details
2308 Common Report Var(time_report_details)
2309 Record times taken by sub-phases separately.
2312 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2313 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2316 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2319 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2322 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2325 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2328 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2331 Common Report Var(flag_toplevel_reorder) Init(2)
2332 Reorder top level functions, variables, and asms.
2335 Common Report Var(flag_tracer) Optimization
2336 Perform superblock formation via tail duplication.
2338 ; Zero means that floating-point math operations cannot generate a
2339 ; (user-visible) trap. This is the case, for example, in nonstop
2340 ; IEEE 754 arithmetic.
2342 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2343 Assume floating-point operations can trap.
2346 Common Report Var(flag_trapv) Optimization
2347 Trap for signed overflow in addition, subtraction and multiplication.
2350 Common Report Var(flag_tree_ccp) Optimization
2351 Enable SSA-CCP optimization on trees.
2354 Common Report Var(flag_tree_bit_ccp) Optimization
2355 Enable SSA-BIT-CCP optimization on trees.
2359 Does nothing. Preserved for backward compatibility.
2362 Common Report Var(flag_tree_ch) Optimization
2363 Enable loop header copying on trees.
2365 ftree-coalesce-inlined-vars
2366 Common Ignore RejectNegative
2367 Does nothing. Preserved for backward compatibility.
2370 Common Report Var(flag_tree_coalesce_vars) Optimization
2371 Enable SSA coalescing of user variables.
2375 Does nothing. Preserved for backward compatibility.
2378 Common Report Var(flag_tree_copy_prop) Optimization
2379 Enable copy propagation on trees.
2381 ftree-store-copy-prop
2383 Does nothing. Preserved for backward compatibility.
2386 Common Report Var(flag_tree_cselim) Init(2) Optimization
2387 Transform condition stores into unconditional ones.
2389 ftree-switch-conversion
2390 Common Report Var(flag_tree_switch_conversion) Optimization
2391 Perform conversions of switch initializations.
2394 Common Report Var(flag_tree_dce) Optimization
2395 Enable SSA dead code elimination optimization on trees.
2397 ftree-dominator-opts
2398 Common Report Var(flag_tree_dom) Optimization
2399 Enable dominator optimizations.
2402 Common Report Var(flag_tree_tail_merge) Optimization
2403 Enable tail merging on trees.
2406 Common Report Var(flag_tree_dse) Optimization
2407 Enable dead store elimination.
2410 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2411 Enable forward propagation on trees.
2414 Common Report Var(flag_tree_fre) Optimization
2415 Enable Full Redundancy Elimination (FRE) on trees.
2418 Common Report Var(flag_optimize_strlen) Optimization
2419 Enable string length optimizations on trees.
2421 fisolate-erroneous-paths-dereference
2422 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2423 Detect paths that trigger erroneous or undefined behavior due to
2424 dereferencing a null pointer. Isolate those paths from the main control
2425 flow and turn the statement with erroneous or undefined behavior into a trap.
2427 fisolate-erroneous-paths-attribute
2428 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2429 Detect paths that trigger erroneous or undefined behavior due a null value
2430 being used in a way forbidden by a returns_nonnull or nonnull
2431 attribute. Isolate those paths from the main control flow and turn the
2432 statement with erroneous or undefined behavior into a trap.
2434 ftree-loop-distribution
2435 Common Report Var(flag_tree_loop_distribution) Optimization
2436 Enable loop distribution on trees.
2438 ftree-loop-distribute-patterns
2439 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2440 Enable loop distribution for patterns transformed into a library call.
2443 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2444 Enable loop invariant motion on trees.
2447 Common Alias(floop-nest-optimize)
2448 Enable loop nest transforms. Same as -floop-nest-optimize.
2451 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2452 Create canonical induction variables in loops.
2455 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2456 Enable loop optimizations on tree level.
2458 ftree-parallelize-loops=
2459 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2460 Enable automatic parallelization of loops.
2463 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2464 Enable hoisting loads from conditional pointers.
2467 Common Report Var(flag_tree_pre) Optimization
2468 Enable SSA-PRE optimization on trees.
2471 Common Report Var(flag_tree_partial_pre) Optimization
2472 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2475 Common Report Var(flag_tree_pta) Optimization
2476 Perform function-local points-to analysis on trees.
2479 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2480 Enable reassociation on tree level.
2484 Does nothing. Preserved for backward compatibility.
2487 Common Report Var(flag_tree_sink) Optimization
2488 Enable SSA code sinking on trees.
2491 Common Report Var(flag_tree_slsr) Optimization
2492 Perform straight-line strength reduction.
2495 Common Report Var(flag_tree_sra) Optimization
2496 Perform scalar replacement of aggregates.
2499 Common Report Var(flag_tree_ter) Optimization
2500 Replace temporary expressions in the SSA->normal pass.
2503 Common Report Var(flag_tree_live_range_split) Optimization
2504 Perform live range splitting during the SSA->normal pass.
2507 Common Report Var(flag_tree_vrp) Init(0) Optimization
2508 Perform Value Range Propagation on trees.
2511 Common Report Var(flag_split_paths) Init(0) Optimization
2512 Split paths leading to loop backedges.
2514 funconstrained-commons
2515 Common Var(flag_unconstrained_commons) Optimization
2516 Assume common declarations may be overridden with ones with a larger
2520 Common Report Var(flag_unit_at_a_time) Init(1)
2521 Compile whole compilation unit at a time.
2524 Common Report Var(flag_unroll_loops) Optimization
2525 Perform loop unrolling when iteration count is known.
2528 Common Report Var(flag_unroll_all_loops) Optimization
2529 Perform loop unrolling for all loops.
2531 ; Nonzero means that loop optimizer may assume that the induction variables
2532 ; that control loops do not overflow and that the loops with nontrivial
2533 ; exit condition are not infinite
2534 funsafe-loop-optimizations
2536 Does nothing. Preserved for backward compatibility.
2539 Common Report Var(flag_associative_math) SetByCombined Optimization
2540 Allow optimization for floating-point arithmetic which may change the
2541 result of the operation due to rounding.
2544 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2545 Same as -fassociative-math for expressions which include division.
2547 ; Nonzero means that unsafe floating-point math optimizations are allowed
2548 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2549 ; are allowed to assume that their arguments and results are "normal"
2550 ; (e.g., nonnegative for SQRT).
2551 funsafe-math-optimizations
2552 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2553 Allow math optimizations that may violate IEEE or ISO standards.
2556 Common Report Var(flag_unswitch_loops) Optimization
2557 Perform loop unswitching.
2560 Common Report Var(flag_unwind_tables) Optimization
2561 Just generate unwind tables for exception handling.
2564 Common Driver Negative(fuse-ld=gold)
2565 Use the bfd linker instead of the default linker.
2568 Common Driver Negative(fuse-ld=bfd)
2569 Use the gold linker instead of the default linker.
2572 Common Undocumented Var(flag_use_linker_plugin)
2574 ; Positive if we should track variables, negative if we should run
2575 ; the var-tracking pass only to discard debug annotations, zero if
2576 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2577 ; will be set according to optimize, debug_info_level and debug_hooks
2578 ; in process_options ().
2580 Common Report Var(flag_var_tracking) Init(2) Optimization
2581 Perform variable tracking.
2583 ; Positive if we should track variables at assignments, negative if
2584 ; we should run the var-tracking pass only to discard debug
2585 ; annotations. When flag_var_tracking_assignments ==
2586 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2587 fvar-tracking-assignments
2588 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2589 Perform variable tracking by annotating assignments.
2591 ; Nonzero if we should toggle flag_var_tracking_assignments after
2592 ; processing options and computing its default. */
2593 fvar-tracking-assignments-toggle
2594 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2595 Toggle -fvar-tracking-assignments.
2597 ; Positive if we should track uninitialized variables, negative if
2598 ; we should run the var-tracking pass only to discard debug
2599 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2600 ; will be set according to flag_var_tracking.
2601 fvar-tracking-uninit
2602 Common Report Var(flag_var_tracking_uninit) Optimization
2603 Perform variable tracking and also tag variables that are uninitialized.
2606 Common Report Var(flag_tree_vectorize) Optimization
2607 Enable vectorization on trees.
2609 ftree-vectorizer-verbose=
2610 Common Joined RejectNegative Ignore
2611 Does nothing. Preserved for backward compatibility.
2613 ftree-loop-vectorize
2614 Common Report Var(flag_tree_loop_vectorize) Optimization
2615 Enable loop vectorization on trees.
2618 Common Report Var(flag_tree_slp_vectorize) Optimization
2619 Enable basic block vectorization (SLP) on trees.
2622 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2623 Specifies the cost model for vectorization.
2626 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2627 Specifies the vectorization cost model for code marked with a simd directive.
2630 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2633 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2636 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2639 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2642 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2643 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2646 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2647 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2649 ftree-vect-loop-version
2651 Does nothing. Preserved for backward compatibility.
2654 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2655 Enable copy propagation of scalar-evolution information.
2657 ; -fverbose-asm causes extra commentary information to be produced in
2658 ; the generated assembly code (to make it more readable). This option
2659 ; is generally only of use to those who actually need to read the
2660 ; generated assembly code (perhaps while debugging the compiler itself).
2661 ; -fno-verbose-asm, the default, causes the extra information
2662 ; to not be added and is useful when comparing two assembler files.
2664 Common Report Var(flag_verbose_asm)
2665 Add extra commentary to assembler output.
2668 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2669 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2672 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2675 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2678 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2681 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2684 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2687 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2688 Validate vtable pointers before using them.
2691 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2694 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2697 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2700 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2703 Common Var(flag_vtv_counts)
2704 Output vtable verification counters.
2707 Common Var(flag_vtv_debug)
2708 Output vtable verification pointer sets information.
2711 Common Report Var(flag_value_profile_transformations) Optimization
2712 Use expression value profiles in optimizations.
2715 Common Report Var(flag_web) Init(2) Optimization
2716 Construct webs and split unrelated uses of single variable.
2718 ftree-builtin-call-dce
2719 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2720 Enable conditional dead code elimination for builtin calls.
2723 Common Report Var(flag_whole_program) Init(0)
2724 Perform whole program optimizations.
2727 Common Report Var(flag_wrapv) Optimization
2728 Assume signed arithmetic overflow wraps around.
2730 fzero-initialized-in-bss
2731 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2732 Put zero initialized data in the bss section.
2735 Common JoinedOrMissing
2736 Generate debug information in default format.
2739 Common JoinedOrMissing Negative(gdwarf)
2740 Generate debug information in COFF format.
2743 Common JoinedOrMissing Negative(gdwarf-)
2744 Generate debug information in default version of DWARF format.
2747 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2748 Generate debug information in DWARF v2 (or later) format.
2751 Common JoinedOrMissing
2752 Generate debug information in default extended format.
2755 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2756 Don't generate DWARF pubnames and pubtypes sections.
2759 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2760 Generate DWARF pubnames and pubtypes sections.
2763 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2764 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2766 gno-record-gcc-switches
2767 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2768 Don't record gcc command line switches in DWARF DW_AT_producer.
2770 grecord-gcc-switches
2771 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2772 Record gcc command line switches in DWARF DW_AT_producer.
2775 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2776 Don't generate debug information in separate .dwo files.
2779 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2780 Generate debug information in separate .dwo files.
2783 Common JoinedOrMissing Negative(gstabs+)
2784 Generate debug information in STABS format.
2787 Common JoinedOrMissing Negative(gvms)
2788 Generate debug information in extended STABS format.
2791 Common RejectNegative Var(dwarf_strict,0) Init(0)
2792 Emit DWARF additions beyond selected version.
2795 Common Report RejectNegative Var(dwarf_strict,1)
2796 Don't emit DWARF additions beyond selected version.
2799 Common Report Var(flag_gtoggle)
2800 Toggle debug information generation.
2803 Common JoinedOrMissing Negative(gxcoff)
2804 Generate debug information in VMS format.
2807 Common JoinedOrMissing Negative(gxcoff+)
2808 Generate debug information in XCOFF format.
2811 Common JoinedOrMissing Negative(gcoff)
2812 Generate debug information in extended XCOFF format.
2815 Name(compressed_debug_sections) Type(int)
2817 ; Since -gz= is completely handled in specs, the values aren't used and we
2818 ; assign arbitrary constants.
2820 Enum(compressed_debug_sections) String(none) Value(0)
2823 Enum(compressed_debug_sections) String(zlib) Value(1)
2826 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2830 Generate compressed debug sections.
2833 Common Driver Joined Enum(compressed_debug_sections)
2834 -gz=<format> Generate compressed debug sections in format <format>.
2837 Driver Joined Separate
2840 Common Joined Var(plugindir_string) Init(0)
2841 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2844 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2845 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2848 Driver Joined Separate
2853 no-canonical-prefixes
2866 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2867 -o <file> Place output into <file>.
2870 Common Var(profile_flag)
2871 Enable function profiling.
2874 Driver Var(pass_exit_codes)
2877 Common Alias(Wpedantic)
2880 Common Var(flag_pedantic_errors)
2881 Like -pedantic but issue them as errors.
2887 Driver Var(use_pipes)
2890 Driver JoinedOrMissing Var(print_file_name)
2892 print-libgcc-file-name
2895 print-multi-directory
2896 Driver Var(print_multi_directory)
2899 Driver Var(print_multi_lib)
2901 print-multi-os-directory
2902 Driver Var(print_multi_os_directory)
2905 Driver Var(print_multiarch)
2908 Driver JoinedOrMissing Var(print_prog_name)
2911 Driver Var(print_search_dirs)
2914 Driver Var(print_sysroot)
2916 print-sysroot-headers-suffix
2917 Driver Var(print_sysroot_headers_suffix)
2920 Common Var(quiet_flag) RejectDriver
2921 Do not display functions compiled or elapsed time.
2939 Driver Var(report_times)
2942 Driver JoinedOrMissing
2945 Driver Joined Separate
2949 ; C option, but driver must not handle as "-u ndef".
2952 Common Driver Var(verbose_flag)
2953 Enable verbose output.
2956 Common Var(version_flag) RejectDriver
2957 Display the compiler's version.
2960 Common Var(inhibit_warnings)
2964 Driver Separate Var(wrapper_string)
2967 Driver Joined Separate
2970 Driver RejectNegative Negative(pie)
2971 Create a shared library.
2977 Driver Separate Alias(specs=)
2990 ; Documented for Fortran, but always accepted by driver.
2997 ; Documented for Go, but always accepted by driver.
3015 Driver RejectNegative Negative(shared)
3016 Don't create a position independent executable.
3019 Driver RejectNegative Negative(no-pie)
3020 Create a position independent executable.
3023 Driver Joined Separate
3026 Common Report Var(flag_ipa_ra) Optimization
3027 Use caller save register across calls if possible.
3029 ; This comment is to ensure we retain the blank line above.