1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 ; Free Software Foundation, Inc.
6 ; This file is part of GCC.
8 ; GCC is free software; you can redistribute it and/or modify it under
9 ; the terms of the GNU General Public License as published by the Free
10 ; Software Foundation; either version 3, or (at your option) any later
13 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 ; You should have received a copy of the GNU General Public License
19 ; along with GCC; see the file COPYING3. If not see
20 ; <http://www.gnu.org/licenses/>.
22 ; See the GCC internals manual (options.texi) for a description of this file's format.
24 ; Please try to keep this file in ASCII collating order.
35 ; Not used directly to control optimizations, only to save -Ofast
36 ; setting for "optimize" attributes.
40 ; True if this is the lto front end. This is used to disable gimple
41 ; generation and lowering passes that are normally run on the output
42 ; of a front end. These passes must be bypassed for lto since they
43 ; have already been done before the gimple was written.
47 ; 0 means straightforward implementation of complex divide acceptable.
48 ; 1 means wide ranges of inputs must work for complex divide.
49 ; 2 means C99-like requirements for complex multiply and divide.
51 int flag_complex_method = 1
53 ; Nonzero if subexpressions must be evaluated from left-to-right.
55 int flag_evaluation_order = 0
57 ; Language specific warning pass for unused results.
59 bool flag_warn_unused_result = false
64 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
68 ; True to warn about any objects definitions whose size is larger
69 ; than N bytes. Also want about function definitions whose returned
70 ; values are larger than N bytes, where N is 'larger_than_size'.
75 HOST_WIDE_INT larger_than_size
77 ; True to warn about any function whose frame size is larger
80 bool warn_frame_larger_than
83 HOST_WIDE_INT frame_larger_than_size
85 ; Nonzero means we should be saving declaration info into a .X file.
87 int flag_gen_aux_info = 0
89 ; Nonzero if we are compiling code for a shared library, zero for
94 ; These two are really VEC(char_p,heap) *.
97 void *flag_instrument_functions_exclude_functions
100 void *flag_instrument_functions_exclude_files
102 ; Generic structs (e.g. templates not explicitly specialized)
103 ; may not have a compilation unit associated with them, and so
104 ; may need to be treated differently from ordinary structs.
106 ; Structs only handled by reference (indirectly), will also usually
107 ; not need as much debugging information.
110 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
113 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
115 ; True if we should exit after parsing options.
117 bool exit_after_options
119 ; Type(s) of debugging information we are producing (if any). See
120 ; flag-types.h for the definitions of the different possible types of
121 ; debugging information.
123 enum debug_info_type write_symbols = NO_DEBUG
125 ; Level of debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
130 ; Whether to generate line number table. Normally set at DINFO_LEVEL_NORMAL
131 ; or above; can also be set for DINFO_LEVEL_TERSE with -gmlt.
133 bool generate_debug_line_table = false
135 ; Nonzero means use GNU-only extensions in the generated symbolic
136 ; debugging information. Currently, this only has an effect when
137 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
139 bool use_gnu_debug_info_extensions
141 ; Original value of maximum field alignment in bytes, specified via
142 ; -fpack-struct=<value>.
144 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
147 enum vect_verbosity_levels user_vect_verbosity_level = MAX_VERBOSITY_LEVEL
149 ; Type of stack check.
151 enum stack_check_type flag_stack_check = NO_STACK_CHECK
153 ; True if stack usage information needs to be computed.
155 bool flag_stack_usage_info = false
157 ; -dA causes debug commentary information to be produced in
158 ; the generated assembly code (to make it more readable). This option
159 ; is generally only of use to those who actually need to read the
160 ; generated assembly code (perhaps while debugging the compiler itself).
161 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
162 ; to be a catchall for printing debug information in the assembler file.
166 ; -dP causes the rtl to be emitted as a comment in assembly.
168 int flag_dump_rtl_in_asm
170 ; Whether -da was passed (used only in handle_common_deferred_options).
172 bool flag_dump_all_passed
174 ; Other flags saying which kinds of debugging dump have been requested.
177 int rtl_dump_and_exit
180 int flag_print_asm_name
183 enum graph_dump_types graph_dump_format = no_graph
185 ; Name of top-level original source file (what was input to cpp).
186 ; This comes from the #-command at the beginning of the actual input.
187 ; If there isn't any there, then this is the cc1 input file name.
189 const char *main_input_filename
191 ; Pointer to base name in main_input_filename, with directories and a
192 ; single final extension removed, and the length of this base
196 const char *main_input_basename
199 int main_input_baselength
201 ; Which options have been printed by --help.
205 ; Which enums have been printed by --help. 0 = not printed, no
206 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
209 char *help_enum_printed
211 ; The number of columns for --help output.
213 unsigned int help_columns
215 ; Whether this options structure has been through finish_options
217 bool flag_opts_finished
229 Driver Alias(coverage)
235 Common Separate Alias(d)
238 Common Joined Alias(d)
241 Common Separate Alias(dumpbase)
244 Common Separate Alias(dumpdir)
247 Driver Separate Alias(e)
250 Driver Joined Alias(e)
253 Common Warning Alias(Wextra)
256 Driver Separate Alias(Xassembler)
259 Driver JoinedOrMissing Alias(Xassembler)
262 Driver Separate Alias(Xlinker)
265 Driver JoinedOrMissing Alias(Xlinker)
268 Driver Separate Alias(u)
271 Driver Joined Alias(u)
274 Common Driver Var(help_flag)
275 Display this information
278 Common Driver Report Joined
279 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
282 Driver Separate Alias(x)
285 Driver Joined Alias(x)
288 Driver Separate Alias(L)
291 Driver Joined Alias(L)
293 -no-canonical-prefixes
294 Driver Alias(no-canonical-prefixes)
297 Driver Alias(canonical-prefixes)
299 -no-standard-libraries
300 Driver Alias(nostdlib)
309 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
312 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
315 Driver Alias(pass-exit-codes)
318 Common Alias(pedantic)
321 Common Alias(pedantic-errors)
330 Driver Separate Alias(B)
333 Driver JoinedOrMissing Alias(B)
339 Driver Separate Alias(print-file-name=)
342 Driver JoinedOrMissing Alias(print-file-name=)
344 -print-libgcc-file-name
345 Driver Alias(print-libgcc-file-name)
347 -print-multi-directory
348 Driver Alias(print-multi-directory)
351 Driver Alias(print-multi-lib)
353 -print-multi-os-directory
354 Driver Alias(print-multi-os-directory)
357 Driver Separate Alias(print-prog-name=)
360 Driver JoinedOrMissing Alias(print-prog-name=)
363 Driver Alias(print-search-dirs)
366 Driver Alias(print-sysroot)
368 -print-sysroot-headers-suffix
369 Driver Alias(print-sysroot-headers-suffix)
375 Driver Alias(save-temps)
381 Driver Separate Alias(specs=)
384 Driver Joined Alias(specs=)
390 Driver Alias(symbolic)
394 Alias for --help=target
402 ;; The driver used to convert options such as --help into forms such
403 ;; as -fhelp; the following four entries are for compatibility with
404 ;; any direct uses of those (undocumented) -f forms
406 Common Driver Alias(-help)
409 Common Driver Joined Alias(-help=)
412 Common Driver Alias(-target-help)
415 Common Driver Alias(-version)
419 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
422 Common Joined Alias(-param)
425 Driver Separate Alias(-sysroot=)
428 Driver JoinedOrMissing
434 Driver Joined Separate
440 Driver Joined Separate
446 Common JoinedOrMissing Optimization
447 -O<number> Set optimization level to <number>
451 Optimize for space rather than speed
455 Optimize for speed disregarding exact standards compliance
467 Driver Joined Separate
473 Driver Joined Separate
494 Common RejectNegative Warning Alias(Wextra)
495 This switch is deprecated; use -Wextra instead
498 Driver JoinedOrMissing
501 Driver JoinedOrMissing
504 Driver JoinedOrMissing
507 Common Var(warn_aggregate_return) Warning
508 Warn about returning structures, unions or arrays
511 Common Var(warn_array_bounds) Warning
512 Warn if an array is accessed out of bounds
515 Common Var(warn_attributes) Init(1) Warning
516 Warn about inappropriate attribute usage
519 Common Var(warn_cast_align) Warning
520 Warn about pointer casts which increase alignment
523 Common Var(warn_cpp) Init(1) Warning
524 Warn when a #warning directive is encountered
526 Wdeprecated-declarations
527 Common Var(warn_deprecated_decl) Init(1) Warning
528 Warn about uses of __attribute__((deprecated)) declarations
530 Wdisabled-optimization
531 Common Var(warn_disabled_optimization) Warning
532 Warn when an optimization pass is disabled
535 Common Var(warnings_are_errors)
536 Treat all warnings as errors
540 Treat specified warning as error
543 Common Var(extra_warnings) Warning
544 Print extra (possibly unwanted) warnings
547 Common Var(flag_fatal_errors)
548 Exit on the first error occurred
551 Common Var(flag_force_warnings)
552 Disable promoting warnings to errors
555 Common RejectNegative Joined UInteger
556 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
559 Common Var(warn_free_nonheap_object) Init(1) Warning
560 Warn when attempting to free a non-heap object
563 Common Var(warn_inline) Warning
564 Warn when an inlined function cannot be inlined
566 Winvalid-memory-model
567 Common Var(warn_invalid_memory_model) Init(1) Warning
568 Warn when an atomic memory model parameter is known to be outside the valid range.
571 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
574 Common RejectNegative Joined UInteger Warning
575 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
577 Wunsafe-loop-optimizations
578 Common Var(warn_unsafe_loop_optimizations) Warning
579 Warn if the loop cannot be optimized due to nontrivial assumptions.
582 Common Var(warn_missing_noreturn) Warning
583 Warn about functions which might be candidates for __attribute__((noreturn))
586 Common Var(warn_overflow) Init(1) Warning
587 Warn about overflow in arithmetic expressions
590 Common Var(warn_packed) Warning
591 Warn when the packed attribute has no effect on struct layout
594 Common Var(warn_padded) Warning
595 Warn when padding is required to align structure members
598 Common Var(warn_ripa_opt_mismatch) Warning
599 Warn if primary and auxiliary modules have mismatched command line options
602 Common Var(warn_self_assign) Init(0) Warning
603 Warn when a variable is assigned to itself
606 Common Var(warn_shadow) Warning
607 Warn when one local variable shadows another
610 Common Var(warn_shadow_local) Warning
611 Warn when one local variable shadows another local variable or parameter
613 Wshadow-compatible-local
614 Common Var(warn_shadow_compatible_local) Warning
615 Warn when one local variable shadows another local variable or parameter
619 Common Var(warn_stack_protect) Warning
620 Warn when not issuing stack smashing protection for some reason
623 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
624 Warn if stack usage might be larger than specified amount
628 Warn about code which might break strict aliasing rules
631 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Init(-1) Warning
632 Warn about code which might break strict aliasing rules
636 Warn about optimizations that assume that signed overflow is undefined
639 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Init(-1) Warning
640 Warn about optimizations that assume that signed overflow is undefined
642 Wsuggest-attribute=const
643 Common Var(warn_suggest_attribute_const) Warning
644 Warn about functions which might be candidates for __attribute__((const))
646 Wsuggest-attribute=pure
647 Common Var(warn_suggest_attribute_pure) Warning
648 Warn about functions which might be candidates for __attribute__((pure))
650 Wsuggest-attribute=noreturn
651 Common Var(warn_suggest_attribute_noreturn) Warning
652 Warn about functions which might be candidates for __attribute__((noreturn))
655 Common Var(warn_switch) Warning
656 Warn about enumerated switches, with no default, missing a case
659 Common Var(warn_switch_default) Warning
660 Warn about enumerated switches missing a \"default:\" statement
663 Common Var(warn_switch_enum) Warning
664 Warn about all enumerated switches missing a specific case
667 Common Var(warn_system_headers) Warning
668 Do not suppress warnings from system headers
671 Common Var(warn_trampolines) Warning
672 Warn whenever a trampoline is generated
675 Common Var(warn_thread_safety) Warning
676 Warn about potential thread safety issues when the code is annotated with thread safety attributes
678 Wthread-unguarded-var
679 Common Var(warn_thread_unguarded_var) Init(1) Warning
680 Warn about shared variables not properly protected by locks specified in the attributes
682 Wthread-unguarded-func
683 Common Var(warn_thread_unguarded_func) Init(1) Warning
684 Warn about function calls not properly protected by locks specified in the attributes
686 Wthread-mismatched-lock-order
687 Common Var(warn_thread_mismatched_lock_order) Init(1) Warning
688 Warn about lock acquisition order inconsistent with what specified in the attributes
690 Wthread-mismatched-lock-acq-rel
691 Common Var(warn_thread_mismatched_lock_acq_rel) Init(1) Warning
692 Warn about mismatched lock acquisition and release
694 Wthread-reentrant-lock
695 Common Var(warn_thread_reentrant_lock) Init(1) Warning
696 Warn about a lock being acquired recursively
698 Wthread-unsupported-lock-name
699 Common Var(warn_unsupported_lock_name) Init(0) Warning
700 Warn about uses of unsupported lock names in attributes
702 Wthread-attr-bind-param
703 Common Var(warn_thread_attr_bind_param) Init(1) Warning
704 Make the thread safety analysis try to bind the function parameters used in the attributes
707 Common Var(warn_type_limits) Init(-1) Warning
708 Warn if a comparison is always true or always false due to the limited range of the data type
711 Common Var(warn_uninitialized) Init(-1) Warning
712 Warn about uninitialized automatic variables
715 Common Var(warn_maybe_uninitialized) Warning
716 Warn about maybe uninitialized automatic variables
720 Does nothing. Preserved for backward compatibility.
723 Common Var(warn_unused) Init(0) Warning
724 Enable all -Wunused- warnings
726 Wunused-but-set-parameter
727 Common Var(warn_unused_but_set_parameter) Init(-1) Warning
728 Warn when a function parameter is only set, otherwise unused
730 Wunused-but-set-variable
731 Common Var(warn_unused_but_set_variable) Init(-1) Warning
732 Warn when a variable is only set, otherwise unused
735 Common Var(warn_unused_function) Init(-1) Warning
736 Warn when a function is unused
739 Common Var(warn_unused_label) Init(-1) Warning
740 Warn when a label is unused
743 Common Var(warn_unused_parameter) Init(-1) Warning
744 Warn when a function parameter is unused
747 Common Var(warn_unused_value) Init(-1) Warning
748 Warn when an expression value is unused
751 Common Var(warn_unused_variable) Init(-1) Warning
752 Warn when a variable is unused
755 Common Var(warn_coverage_mismatch) Init(1) Warning
756 Warn in case profiles in -fprofile-use do not match
758 Wvector-operation-performance
759 Common Var(warn_vector_operation_performance) Warning
760 Warn when a vector operation is compiled outside the SIMD
778 Common Separate Var(aux_info_file_name)
779 -aux-info <file> Emit declaration information into <file>
782 Common Joined Alias(aux-info)
785 Common Separate RejectDriver Var(aux_base_name)
788 Common Separate RejectDriver
798 -d<letters> Enable dumps from specific passes of the compiler
801 Common Separate Var(dump_base_name)
802 -dumpbase <file> Set the file basename to be used for dumps
805 Common Separate Var(dump_dir_name)
806 -dumpdir <dir> Set the directory name to be used for dumps
818 Driver Joined Separate
820 ; This option has historically been passed down to the linker by an
821 ; accident of a %{e*} spec, so ensure it continues to be passed down
822 ; as a single option. The supported option for this purpose is
823 ; -rdynamic. See PR 47390.
827 ; The version of the C++ ABI in use. The following values are allowed:
829 ; 0: The version of the ABI believed most conformant with the C++ ABI
830 ; specification. This ABI may change as bugs are discovered and fixed.
831 ; Therefore, 0 will not necessarily indicate the same ABI in different
834 ; 1: The version of the ABI first used in G++ 3.2.
836 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
838 ; 3: The version of the ABI that fixes the missing underscore
839 ; in template non-type arguments of pointer type.
841 ; 4: The version of the ABI that introduces unambiguous mangling of
842 ; vector types. First selectable in G++ 4.5.
844 ; 5: The version of the ABI that ignores attribute const/noreturn
845 ; in function pointer mangling, and corrects mangling of decltype and
846 ; function parameters used in other parameters and the return type.
847 ; First selectable in G++ 4.6.
849 ; 6: The version of the ABI that doesn't promote scoped enums to int and
850 ; changes the mangling of template argument packs, const/static_cast,
851 ; prefix ++ and --, and a class scope function used as a template
853 ; First selectable in G++ 4.7.
855 ; Additional positive integers will be assigned as new versions of
856 ; the ABI become the default version of the ABI.
858 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)
861 Common Report Var(align_functions,0) Optimization UInteger
862 Align the start of functions
865 Common RejectNegative Joined UInteger Var(align_functions)
868 Common Report Var(align_jumps,0) Optimization UInteger
869 Align labels which are only reached by jumping
872 Common RejectNegative Joined UInteger Var(align_jumps)
875 Common Report Var(align_labels,0) Optimization UInteger
879 Common RejectNegative Joined UInteger Var(align_labels)
882 Common Report Var(align_loops,0) Optimization UInteger
883 Align the start of loops
886 Common RejectNegative Joined UInteger Var(align_loops)
890 Does nothing. Preserved for backward compatibility.
894 Does nothing. Preserved for backward compatibility.
896 fargument-noalias-global
898 Does nothing. Preserved for backward compatibility.
900 fargument-noalias-anything
902 Does nothing. Preserved for backward compatibility.
905 Common RejectNegative Report Var(flag_asan)
906 Enable AddressSanitizer, a memory error detector
908 fasynchronous-unwind-tables
909 Common Report Var(flag_asynchronous_unwind_tables) Optimization
910 Generate unwind tables that are exact at each instruction boundary
913 Common Report Var(flag_auto_inc_dec) Init(1)
914 Generate auto-inc/dec instructions
916 ; -fcheck-bounds causes gcc to generate array bounds checks.
917 ; For C, C++ and ObjC: defaults off.
918 ; For Java: defaults to on.
919 ; For Fortran: defaults to off.
921 Common Report Var(flag_bounds_check)
922 Generate code to check bounds before indexing arrays
925 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
926 Replace add, compare, branch with branch on count register
928 fbranch-probabilities
929 Common Report Var(flag_branch_probabilities) Optimization
930 Use profiling information for branch probabilities
932 fbranch-target-load-optimize
933 Common Report Var(flag_branch_target_load_optimize) Optimization
934 Perform branch target load optimization before prologue / epilogue threading
936 fbranch-target-load-optimize2
937 Common Report Var(flag_branch_target_load_optimize2) Optimization
938 Perform branch target load optimization after prologue / epilogue threading
941 Common Report Var(flag_btr_bb_exclusive) Optimization
942 Restrict target load migration not to re-use registers in any basic block
945 Common Joined RejectNegative Var(common_deferred_options) Defer
946 -fcall-saved-<register> Mark <register> as being preserved across functions
949 Common Joined RejectNegative Var(common_deferred_options) Defer
950 -fcall-used-<register> Mark <register> as being corrupted by function calls
952 ; Nonzero for -fcaller-saves: allocate values in regs that need to
953 ; be saved across function calls, if that produces overall better code.
954 ; Optional now, so people can test it.
956 Common Report Var(flag_caller_saves) Optimization
957 Save registers around function calls
960 Common Report Var(flag_check_data_deps)
961 Compare the results of several data dependence analyzers.
963 fcombine-stack-adjustments
964 Common Report Var(flag_combine_stack_adjustments) Optimization
965 Looks for opportunities to reduce stack adjustments and stack references.
968 Common Report Var(flag_no_common,0) Optimization
969 Do not put uninitialized globals in the common section
973 ; Converted by the driver to -fcompare-debug= options.
976 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
977 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
979 fcompare-debug-second
980 Common Driver RejectNegative Var(flag_compare_debug)
981 Run only the second compilation of -fcompare-debug
984 Common Report Var(flag_compare_elim_after_reload) Optimization
985 Perform comparison elimination after register allocation has finished
988 Common Var(flag_conserve_stack) Optimization
989 Do not perform optimizations increasing noticeably stack usage
992 Common Report Var(flag_cprop_registers) Optimization
993 Perform a register copy-propagation optimization pass
996 Common Report Var(flag_crossjumping) Optimization
997 Perform cross-jumping optimization
1000 Common Report Var(flag_cse_follow_jumps) Optimization
1001 When running CSE, follow jumps to their targets
1005 Does nothing. Preserved for backward compatibility.
1008 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1009 Omit range reduction step when performing complex division
1012 Common Report Var(flag_cx_fortran_rules) Optimization
1013 Complex multiplication and division follow Fortran rules
1016 Common Report Var(flag_data_sections) Optimization
1017 Place data items into their own section
1020 Common Report Var(common_deferred_options) Defer
1021 List all available debugging counters with their limits and counts.
1024 Common RejectNegative Joined Var(common_deferred_options) Defer
1025 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1028 Common Joined RejectNegative Var(common_deferred_options) Defer
1029 Map one directory name to another in debug information
1031 fdebug-types-section
1032 Common Report Var(flag_debug_types_section) Init(1)
1033 Output .debug_types section when using DWARF v4 debuginfo.
1035 ; Nonzero for -fdefer-pop: don't pop args after each function call
1036 ; instead save them up to pop many calls' args with one insns.
1038 Common Report Var(flag_defer_pop) Optimization
1039 Defer popping functions args from stack until later
1042 Common Report Var(flag_delayed_branch) Optimization
1043 Attempt to fill delay slots of branch instructions
1045 fdelete-null-pointer-checks
1046 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
1047 Delete useless null pointer checks
1050 Common Report Var(flag_devirtualize) Optimization
1051 Try to convert virtual calls to direct ones.
1053 fdiagnostics-show-location=
1054 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1055 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1057 ; Required for these enum values.
1062 Name(diagnostic_prefixing_rule) Type(int)
1065 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1068 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1070 fdiagnostics-show-option
1071 Common Var(flag_diagnostics_show_option) Init(1)
1072 Amend appropriate diagnostic messages with the command line option that controls them
1075 Common Joined RejectNegative Var(common_deferred_options) Defer
1076 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1079 Common Joined RejectNegative Var(common_deferred_options) Defer
1080 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1083 Common Joined RejectNegative Var(common_deferred_options) Defer
1084 -fdump-<type> Dump various compiler internals to a file
1087 Driver RejectNegative
1090 Common RejectNegative Joined Var(flag_dump_final_insns)
1091 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1094 Common RejectNegative Joined Var(flag_dump_go_spec)
1095 -fdump-go-spec=filename Write all declarations to file as Go code
1098 Common Report Var(flag_dump_noaddr)
1099 Suppress output of addresses in debugging dumps
1102 Common Var(flag_dump_passes) Init(0)
1103 Dump optimization passes
1106 Common Report Var(flag_dump_unnumbered)
1107 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1109 fdump-unnumbered-links
1110 Common Report Var(flag_dump_unnumbered_links)
1111 Suppress output of previous and next insn numbers in debugging dumps
1114 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1115 Enable CFI tables via GAS assembler directives.
1118 Common Report Var(flag_profile_reusedist)
1119 Profile generation for memory reuse distance.
1122 Common Report Var(flag_optimize_locality)
1123 Optimization based on improving memory reference locality.
1126 Common Report Var(flag_dyn_ipa)
1127 Perform Dynamic Inter-Procedural Analysis.
1129 fripa-disallow-asm-modules
1130 Common Report Var(flag_ripa_disallow_asm_modules)
1131 Don't import an auxiliary module if it contains asm statements
1133 fripa-disallow-opt-mismatch
1134 Common Report Var(flag_ripa_disallow_opt_mismatch)
1135 Don't import an auxiliary module if the command line options mismatch with the primary module
1137 fripa-no-promote-always-inline-func
1138 Common Report Var(flag_ripa_no_promote_always_inline) Init(0)
1139 Don't promote always inline static functions assuming they
1140 will be inlined and no copy is needed.
1143 Common Joined RejectNegative Var(lipo_inc_path_pattern)
1144 Substitute substring in include paths with a new string to allow reuse profile data
1147 Common Report Var(flag_early_inlining) Init(1) Optimization
1148 Perform early inlining
1150 feliminate-dwarf2-dups
1151 Common Report Var(flag_eliminate_dwarf2_dups)
1152 Perform DWARF2 duplicate elimination
1155 Common Report Var(flag_ipa_sra) Init(0) Optimization
1156 Perform interprocedural reduction of aggregates
1158 feliminate-unused-debug-symbols
1159 Common Report Var(flag_debug_only_used_symbols)
1160 Perform unused type elimination in debug info
1162 feliminate-unused-debug-types
1163 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1164 Perform unused type elimination in debug info
1166 femit-class-debug-always
1167 Common Report Var(flag_emit_class_debug_always) Init(0)
1168 Do not suppress C++ class debug information.
1171 Common Report Var(flag_exceptions) Optimization
1172 Enable exception handling
1174 fexpensive-optimizations
1175 Common Report Var(flag_expensive_optimizations) Optimization
1176 Perform a number of minor, expensive optimizations
1179 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1180 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1183 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1186 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1189 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1195 Common Var(flag_fat_lto_objects) Init(1)
1196 Output lto objects containing both the intermediate language and binary output.
1199 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1200 Assume no NaNs or infinities are generated
1203 Common Joined RejectNegative Var(common_deferred_options) Defer
1204 -ffixed-<register> Mark <register> as being unavailable to the compiler
1207 Common Report Var(flag_float_store) Optimization
1208 Don't allocate floats and doubles in extended-precision registers
1212 Does nothing. Preserved for backward compatibility.
1215 Common Report Var(flag_forward_propagate) Optimization
1216 Perform a forward propagation pass on RTL
1219 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1220 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1223 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1226 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1228 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1230 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1233 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1235 ffunction-attribute-list=
1236 Common Joined RejectNegative Var(common_deferred_options) Defer
1237 -ffunction-attribute-list=attribute:name,... Add attribute to named functions
1239 ; Nonzero means don't put addresses of constant functions in registers.
1240 ; Used for compiling the Unix kernel, where strange substitutions are
1241 ; done on the assembly output.
1243 Common Report Var(flag_no_function_cse,0)
1244 Allow function addresses to be held in registers
1247 Common Report Var(flag_function_sections)
1248 Place each function into its own section
1251 Common Report Var(flag_gcse) Optimization
1252 Perform global common subexpression elimination
1255 Common Report Var(flag_gcse_lm) Init(1) Optimization
1256 Perform enhanced load motion during global common subexpression elimination
1259 Common Report Var(flag_gcse_sm) Init(0) Optimization
1260 Perform store motion after global common subexpression elimination
1263 Common Report Var(flag_gcse_las) Init(0) Optimization
1264 Perform redundant load after store elimination in global common subexpression
1268 Common Report Var(flag_gcse_after_reload) Optimization
1269 Perform global common subexpression elimination after register allocation
1272 ; This option is not documented yet as its semantics will change.
1274 Common Report Var(flag_graphite)
1275 Enable in and out of Graphite representation
1278 Common Report Var(flag_graphite_identity) Optimization
1279 Enable Graphite Identity transformation
1281 floop-parallelize-all
1282 Common Report Var(flag_loop_parallelize_all) Optimization
1283 Mark all loops as parallel
1286 Common Report Var(flag_loop_strip_mine) Optimization
1287 Enable Loop Strip Mining transformation
1290 Common Report Var(flag_loop_interchange) Optimization
1291 Enable Loop Interchange transformation
1294 Common Report Var(flag_loop_block) Optimization
1295 Enable Loop Blocking transformation
1298 Common Report Var(flag_tm)
1299 Enable support for GNU transactional memory
1302 Common Report Var(flag_loop_flatten) Optimization
1303 Enable Loop Flattening transformation
1305 fstrict-volatile-bitfields
1306 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1307 Force bitfield accesses to match their type width
1309 fguess-branch-probability
1310 Common Report Var(flag_guess_branch_prob) Optimization
1311 Enable guessing of branch probabilities
1313 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1314 ; Generate position-independent code for executables if possible
1315 ; On SVR4 targets, it also controls whether or not to emit a
1316 ; string identifying the compiler.
1318 Common Report Var(flag_no_ident,0)
1319 Process #ident directives
1322 Common Report Var(flag_if_conversion) Optimization
1323 Perform conversion of conditional jumps to branchless equivalents
1326 Common Report Var(flag_if_conversion2) Optimization
1327 Perform conversion of conditional jumps to conditional execution
1330 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1331 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1334 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1337 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1340 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1343 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1345 ftree-loop-if-convert
1346 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1347 Convert conditional jumps in innermost loops to branchless equivalents
1349 ftree-loop-if-convert-stores
1350 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1351 Also if-convert conditional jumps containing memory writes
1353 ; -finhibit-size-directive inhibits output of .size for ELF.
1354 ; This is used only for compiling crtstuff.c,
1355 ; and it may be extended to other effects
1356 ; needed for crtstuff.c on other systems.
1357 finhibit-size-directive
1358 Common Report Var(flag_inhibit_size_directive)
1359 Do not generate .size directives
1362 Common Report Var(flag_indirect_inlining)
1363 Perform indirect inlining
1365 ; General flag to enable inlining. Specifying -fno-inline will disable
1366 ; all inlining apart from always-inline functions.
1368 Common Report Var(flag_no_inline,0) Init(0)
1369 Enable inlining of function declared \"inline\", disabling disables all inlining
1371 finline-small-functions
1372 Common Report Var(flag_inline_small_functions) Optimization
1373 Integrate functions into their callers when code size is known not to grow
1376 Common Report Var(flag_inline_functions) Optimization
1377 Integrate functions not declared \"inline\" into their callers when profitable
1379 finline-functions-called-once
1380 Common Report Var(flag_inline_functions_called_once) Optimization
1381 Integrate functions only required by their single caller
1384 Common RejectNegative Joined Alias(finline-limit=)
1387 Common RejectNegative Joined UInteger
1388 -finline-limit=<number> Limit the size of inlined functions to <number>
1391 Common Report Var(flag_inline_atomics) Init(1) Optimization
1392 Inline __atomic operations when a lock free instruction sequence is available.
1394 finstrument-functions
1395 Common Report Var(flag_instrument_function_entry_exit)
1396 Instrument function entry and exit with profiling calls
1398 finstrument-functions-exclude-function-list=
1399 Common RejectNegative Joined
1400 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1402 finstrument-functions-exclude-file-list=
1403 Common RejectNegative Joined
1404 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1407 Common Report Var(flag_ipa_cp) Optimization
1408 Perform Interprocedural constant propagation
1411 Common Report Var(flag_ipa_cp_clone) Optimization
1412 Perform cloning to make Interprocedural constant propagation stronger
1415 Common Report Var(flag_ipa_profile) Init(0) Optimization
1416 Perform interprocedural profile propagation
1419 Common Report Var(flag_ipa_pta) Init(0) Optimization
1420 Perform interprocedural points-to analysis
1423 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1424 Discover pure and const functions
1427 Common Report Var(flag_ipa_reference) Init(0) Optimization
1428 Discover readonly and non addressable static variables
1431 Common Report Var(flag_ipa_matrix_reorg) Optimization
1432 Perform matrix layout flattening and transposing based
1433 on profiling information.
1437 Does nothing. Preserved for backward compatibility.
1440 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1441 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1444 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1447 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1450 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1453 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1454 -fira-region=[one|all|mixed] Set regions for IRA
1457 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1460 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1463 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1466 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1469 Common Report Var(flag_ira_loop_pressure)
1470 Use IRA based register pressure calculation
1471 in RTL loop optimizations.
1473 fira-share-save-slots
1474 Common Report Var(flag_ira_share_save_slots) Init(1)
1475 Share slots for saving different hard registers.
1477 fira-share-spill-slots
1478 Common Report Var(flag_ira_share_spill_slots) Init(1)
1479 Share stack slots for spilled pseudo-registers.
1482 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1483 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1486 Common Report Var(flag_ivopts) Init(1) Optimization
1487 Optimize induction variables on trees
1490 Common Var(flag_jump_tables) Init(1) Optimization
1491 Use jump tables for sufficiently large switch statements
1493 fkeep-inline-functions
1494 Common Report Var(flag_keep_inline_functions)
1495 Generate code for functions even if they are fully inlined
1498 Common Report Var(flag_keep_static_consts) Init(1)
1499 Emit static const variables even if they are not used
1502 Common Report Var(flag_leading_underscore) Init(-1)
1503 Give external symbols a leading underscore
1507 Does nothing. Preserved for backward compatibility.
1511 Enable link-time optimization.
1514 Common RejectNegative Joined Var(flag_lto)
1515 Link-time optimization with number of parallel jobs or jobserver.
1518 Common Var(flag_lto_partition_1to1)
1519 Partition functions and vars at linktime based on object files they originate from
1521 flto-partition=balanced
1522 Common Var(flag_lto_partition_balanced)
1523 Partition functions and vars at linktime into approximately same sized buckets
1526 Common Var(flag_lto_partition_none)
1527 Disable partioning and streaming
1529 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1530 flto-compression-level=
1531 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1532 -flto-compression-level=<number> Use zlib compression level <number> for IL
1535 Common Report Var(flag_lto_report) Init(0)
1536 Report various link-time optimization statistics
1539 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1540 Set errno after built-in math functions
1543 Common Joined RejectNegative UInteger Var(flag_max_errors)
1544 -fmax-errors=<number> Maximum number of errors to report
1547 Common Report Var(mem_report)
1548 Report on permanent memory allocation
1550 ; This will attempt to merge constant section constants, if 1 only
1551 ; string constants and constants from constant pool, if 2 also constant
1553 fmerge-all-constants
1554 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1555 Attempt to merge identical constants and constant variables
1558 Common Report Var(flag_merge_constants,1) Optimization
1559 Attempt to merge identical constants across compilation units
1561 fmerge-debug-strings
1562 Common Report Var(flag_merge_debug_strings) Init(1)
1563 Attempt to merge identical debug strings across compilation units
1566 Common RejectNegative Joined UInteger
1567 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1570 Common Report Var(flag_modulo_sched) Optimization
1571 Perform SMS based modulo scheduling before the first scheduling pass
1573 fmodulo-sched-allow-regmoves
1574 Common Report Var(flag_modulo_sched_allow_regmoves)
1575 Perform SMS based modulo scheduling with register moves allowed
1577 fmove-loop-invariants
1578 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
1579 Move loop invariant computations out of loops
1582 Common RejectNegative Report Var(flag_tsan)
1583 Add ThreadSanitizer instrumentation
1586 Common RejectNegative Joined Var(flag_tsan_ignore)
1587 -ftsan-ignore=filename ThreadSanitizer ignore file
1590 Common Var(flag_dce) Init(1) Optimization
1591 Use the RTL dead code elimination pass
1594 Common Var(flag_dse) Init(1) Optimization
1595 Use the RTL dead store elimination pass
1597 freschedule-modulo-scheduled-loops
1598 Common Report Var(flag_resched_modulo_sched) Optimization
1599 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1601 fnon-call-exceptions
1602 Common Report Var(flag_non_call_exceptions) Optimization
1603 Support synchronous non-call exceptions
1606 Common Report Var(flag_omit_frame_pointer) Optimization
1607 When possible do not generate stack frames
1610 Common Report Var(flag_opt_info) Optimization Init(0)
1611 Enable verbose informational messages for optimizations (same as -fopt-info=1)
1613 ; fopt-info=0: no message will be emitted.
1614 ; fopt-info or fopt-info=1: emit important warnings and optimization messages with
1615 ; large performance impact.
1616 ; fopt-info=2: warnings and optimization messages targeting power users.
1617 ; fopt-info=3: informational messages for compiler developers.
1619 Common RejectNegative Joined UInteger Optimization
1620 -fopt-info=[0|1|2|3] Set the verbose level of informational messages for optimizations
1622 foptimize-register-move
1623 Common Report Var(flag_regmove) Optimization
1624 Do the full register move optimization pass
1626 foptimize-sibling-calls
1627 Common Report Var(flag_optimize_sibling_calls) Optimization
1628 Optimize sibling and tail recursive calls
1631 Common Report Var(flag_partial_inlining)
1632 Perform partial inlining
1635 Common Report Var(pre_ipa_mem_report)
1636 Report on memory allocation before interprocedural optimization
1638 fpost-ipa-mem-report
1639 Common Report Var(post_ipa_mem_report)
1640 Report on memory allocation before interprocedural optimization
1643 Common Report Var(flag_pack_struct) Optimization
1644 Pack structure members together without holes
1647 Common RejectNegative Joined UInteger Optimization
1648 -fpack-struct=<number> Set initial maximum structure member alignment
1651 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1652 Return small aggregates in memory, not registers
1654 fpeel-codesize-limit
1655 Common Report Var(flag_peel_codesize_limit) Init(1) Optimization
1656 Limit non-const non-FP loop peeling under profile estimates of large code footprint
1659 Common Report Var(flag_peel_loops) Optimization
1660 Perform loop peeling
1663 Common Report Var(flag_no_peephole,0) Optimization
1664 Enable machine specific peephole optimizations
1667 Common Report Var(flag_peephole2) Optimization
1668 Enable an RTL peephole pass before sched2
1671 Common Report Var(flag_pic,2)
1672 Generate position-independent code if possible (large mode)
1675 Common Report Var(flag_pie,2)
1676 Generate position-independent code for executables if possible (large mode)
1679 Common Report Var(flag_pic,1)
1680 Generate position-independent code if possible (small mode)
1683 Common Report Var(flag_pie,1)
1684 Generate position-independent code for executables if possible (small mode)
1687 Common Joined RejectNegative Var(common_deferred_options) Defer
1688 Specify a plugin to load
1691 Common Joined RejectNegative Var(common_deferred_options) Defer
1692 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1694 fpmu-profile-generate=
1695 Common Joined RejectNegative Var(flag_pmu_profile_generate)
1696 -fpmu-profile-generate=[load-latency] Generate pmu profile for cache misses. Currently only pfmon based load latency profiling is supported on Intel/PEBS and AMD/IBS platforms.
1699 Common Joined RejectNegative Var(flag_pmu_profile_use)
1700 -fpmu-profile-use=[load-latency] Use pmu profile data while optimizing. Currently only perfmon based load latency profiling is supported on Intel/PEBS and AMD/IBS platforms.
1702 fpredictive-commoning
1703 Common Report Var(flag_predictive_commoning) Optimization
1704 Run predictive commoning optimization.
1706 fprefetch-loop-arrays
1707 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1708 Generate prefetch instructions, if available, for arrays in loops
1711 Common Report Var(profile_flag)
1712 Enable basic program profiling code
1715 Common Report Var(profile_arc_flag)
1716 Insert arc-based program profiling code
1719 Common Joined RejectNegative Var(profile_data_prefix)
1720 Set the top-level directory for storing the profile data.
1721 The default is 'pwd'.
1724 Common Report Var(flag_profile_correction)
1725 Enable correction of flow inconsistent profile data input
1728 Common Report Var(flag_profile_dump) Init(0) Optimization
1729 Dump CFG profile for comparison.
1733 Enable common options for generating profile info for profile feedback directed optimizations
1736 Common Joined RejectNegative
1737 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1739 fprofile-generate-sampling
1740 Common Var(flag_profile_generate_sampling)
1741 Turn on instrumentation sampling with -fprofile-generate with rate set by --param profile-generate-sampling-rate or environment variable GCOV_SAMPLING_RATE
1744 Common Joined RejectNegative Var(profile_base_name_suffix_to_strip)
1745 Specify a substring to be stripped from the profile base file name
1748 Common Var(flag_profile_use)
1749 Enable common options for performing profile feedback directed optimizations
1752 Common Joined RejectNegative
1753 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1756 Common Report Var(flag_profile_values)
1757 Insert code to profile values of expressions
1760 Common Var(common_deferred_options) Defer
1763 Common Joined RejectNegative Var(common_deferred_options) Defer
1764 -frandom-seed=<string> Make compile reproducible using <string>
1766 ; This switch causes the command line that was used to create an
1767 ; object file to be recorded into the object file. The exact format
1768 ; of this recording is target and binary file format dependent.
1769 ; It is related to the -fverbose-asm switch, but that switch only
1770 ; records information in the assembler output file as comments, so
1771 ; they never reach the object file.
1772 frecord-gcc-switches
1773 Common Report Var(flag_record_gcc_switches)
1774 Record gcc command line switches in the object file.
1776 ; This option differs from frecord-gcc-switches in the way that it
1777 ; divide the command line options into several categories. And the
1778 ; section is not mergable so that linker can save gcc switches for
1780 frecord-gcc-switches-in-elf
1781 Common Report Var(flag_record_gcc_switches_in_elf)
1782 Record the compiler optimizations in a .gnu.switches.text section.
1785 Common Report Var(flag_pcc_struct_return,0) Optimization
1786 Return small aggregates in registers
1789 Common Report Var(flag_regmove) Optimization
1790 Enables a register move optimization
1793 Common Report Var(flag_rename_registers) Init(2) Optimization
1794 Perform a register renaming optimization pass
1797 Common Report Var(flag_reorder_blocks) Optimization
1798 Reorder basic blocks to improve code placement
1800 freorder-blocks-and-partition
1801 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1802 Reorder basic blocks and partition into hot and cold sections
1805 Common Report Var(flag_reorder_functions) Optimization
1806 Reorder functions to improve code placement
1809 Common Joined RejectNegative Enum(function_reorder) Var(flag_reorder_functions) Init(0) Optimization
1810 -freorder-functions=[callgraph] Select the scheme for function reordering. This invokes a linker plugin. Generate .gnu.callgraph.text sections listing callees and edge counts.
1813 Name(function_reorder) Type(int) UnknownError(unrecognized function reorder value %qs)
1816 Enum(function_reorder) String(callgraph) Value(2)
1818 frerun-cse-after-loop
1819 Common Report Var(flag_rerun_cse_after_loop) Optimization
1820 Add a common subexpression elimination pass after loop optimizations
1824 Does nothing. Preserved for backward compatibility.
1827 Common Report Var(flag_rounding_math) Optimization SetByCombined
1828 Disable optimizations that assume default FP rounding behavior
1831 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1832 Enable scheduling across basic blocks
1835 Common Report Var(flag_sched_pressure) Init(0) Optimization
1836 Enable register pressure sensitive insn scheduling
1839 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1840 Allow speculative motion of non-loads
1843 Common Report Var(flag_schedule_speculative_load) Optimization
1844 Allow speculative motion of some loads
1846 fsched-spec-load-dangerous
1847 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1848 Allow speculative motion of more loads
1851 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1852 -fsched-verbose=<number> Set the verbosity level of the scheduler
1854 fsched2-use-superblocks
1855 Common Report Var(flag_sched2_use_superblocks) Optimization
1856 If scheduling post reload, do superblock scheduling
1860 Does nothing. Preserved for backward compatibility.
1863 Common Report Var(flag_schedule_insns) Optimization
1864 Reschedule instructions before register allocation
1867 Common Report Var(flag_schedule_insns_after_reload) Optimization
1868 Reschedule instructions after register allocation
1870 ; This flag should be on when a target implements non-trivial
1871 ; scheduling hooks, maybe saving some information for its own sake.
1872 ; On IA64, for example, this is used for correct bundling.
1873 fselective-scheduling
1874 Common Report Var(flag_selective_scheduling) Optimization
1875 Schedule instructions using selective scheduling algorithm
1877 fselective-scheduling2
1878 Common Report Var(flag_selective_scheduling2) Optimization
1879 Run selective scheduling after reload
1881 fsel-sched-pipelining
1882 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1883 Perform software pipelining of inner loops during selective scheduling
1885 fsel-sched-pipelining-outer-loops
1886 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1887 Perform software pipelining of outer loops during selective scheduling
1889 fsel-sched-reschedule-pipelined
1890 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1891 Reschedule pipelined regions without pipelining
1893 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1894 ; of stalled insns into the ready list.
1895 fsched-stalled-insns
1896 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1897 Allow premature scheduling of queued insns
1899 fsched-stalled-insns=
1900 Common RejectNegative Joined UInteger
1901 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1903 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1904 ; be examined for a dependency on a stalled insn that is candidate for
1905 ; premature removal from the queue of stalled insns into the ready list (has
1906 ; an effect only if the flag 'sched_stalled_insns' is set).
1907 fsched-stalled-insns-dep
1908 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1909 Set dependence distance checking in premature scheduling of queued insns
1911 fsched-stalled-insns-dep=
1912 Common RejectNegative Joined UInteger
1913 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1915 fsched-group-heuristic
1916 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1917 Enable the group heuristic in the scheduler
1919 fsched-critical-path-heuristic
1920 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1921 Enable the critical path heuristic in the scheduler
1923 fsched-spec-insn-heuristic
1924 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1925 Enable the speculative instruction heuristic in the scheduler
1927 fsched-rank-heuristic
1928 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1929 Enable the rank heuristic in the scheduler
1931 fsched-last-insn-heuristic
1932 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1933 Enable the last instruction heuristic in the scheduler
1935 fsched-dep-count-heuristic
1936 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1937 Enable the dependent count heuristic in the scheduler
1940 Common Report Var(flag_section_anchors) Optimization
1941 Access data in the same section from shared anchor points
1945 Does nothing. Preserved for backward compatibility.
1949 Does nothing. Preserved for backward compatibility.
1952 Common Report Var(flag_ree) Init(0)
1953 Turn on Redundant Extensions Elimination pass.
1956 Common Report Var(flag_show_column) Init(1)
1957 Show column numbers in diagnostics, when available. Default on
1960 Common Report Var(flag_shrink_wrap) Optimization
1961 Emit function prologues only before parts of the function that need it,
1962 rather than at the top of the function.
1965 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1966 Disable optimizations observable by IEEE signaling NaNs
1969 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1970 Disable floating point optimizations that ignore the IEEE signedness of zero
1972 fsingle-precision-constant
1973 Common Report Var(flag_single_precision_constant) Optimization
1974 Convert floating point constants to single precision constants
1977 Common Report Var(flag_sized_delete) Optimization
1978 Support delete operator with objetc's size as the second parameter.
1980 fsplit-ivs-in-unroller
1981 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1982 Split lifetimes of induction variables when loops are unrolled
1985 Common Report Var(flag_split_stack) Init(-1)
1986 Generate discontiguous stack frames
1989 Common Report Var(flag_split_wide_types) Optimization
1990 Split wide types into independent registers
1992 fvariable-expansion-in-unroller
1993 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1994 Apply variable expansion when loops are unrolled
1997 Common Report RejectNegative Joined
1998 -fstack-check=[no|generic|specific] Insert stack checking code into the program
2001 Common Alias(fstack-check=, specific, no)
2002 Insert stack checking code into the program. Same as -fstack-check=specific
2005 Common Var(common_deferred_options) Defer
2007 fstack-limit-register=
2008 Common RejectNegative Joined Var(common_deferred_options) Defer
2009 -fstack-limit-register=<register> Trap if the stack goes past <register>
2011 fstack-limit-symbol=
2012 Common RejectNegative Joined Var(common_deferred_options) Defer
2013 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
2016 Common Report Var(flag_stack_protect, 1)
2017 Use propolice as a stack protection method
2019 fstack-protector-strong
2020 Common Report RejectNegative Var(flag_stack_protect, 2)
2021 Use a smart stack protection method for certain functions
2023 fstack-protector-all
2024 Common Report RejectNegative Var(flag_stack_protect, 3)
2025 Use a stack protection method for every function
2028 Common RejectNegative Var(flag_stack_usage)
2029 Output stack usage information on a per-function basis
2033 Does nothing. Preserved for backward compatibility.
2035 ; Nonzero if we should do (language-dependent) alias analysis.
2036 ; Typically, this analysis will assume that expressions of certain
2037 ; types do not alias expressions of certain other types. Only used
2038 ; if alias analysis (in general) is enabled.
2040 Common Report Var(flag_strict_aliasing) Optimization
2041 Assume strict aliasing rules apply
2044 Common Report Var(flag_strict_overflow)
2045 Treat signed overflow as undefined
2048 Common Report Var(flag_syntax_only)
2049 Check for syntax errors, then stop
2052 Common Report Var(flag_test_coverage)
2053 Create data files needed by \"gcov\"
2056 Common Report Var(flag_thread_jumps) Optimization
2057 Perform jump threading optimizations
2060 Common Report Var(time_report)
2061 Report the time taken by each compiler pass
2064 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2065 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
2068 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2071 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2074 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2077 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2080 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2083 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2084 Reorder top level functions, variables, and asms
2087 Common Report Var(flag_tracer)
2088 Perform superblock formation via tail duplication
2090 ; Zero means that floating-point math operations cannot generate a
2091 ; (user-visible) trap. This is the case, for example, in nonstop
2092 ; IEEE 754 arithmetic.
2094 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2095 Assume floating-point operations can trap
2098 Common Report Var(flag_trapv) Optimization
2099 Trap for signed overflow in addition, subtraction and multiplication
2102 Common Report Var(flag_tree_ccp) Optimization
2103 Enable SSA-CCP optimization on trees
2106 Common Report Var(flag_tree_bit_ccp) Optimization
2107 Enable SSA-BIT-CCP optimization on trees
2111 Does nothing. Preserved for backward compatibility.
2114 Common Report Var(flag_tree_ch) Optimization
2115 Enable loop header copying on trees
2118 Common Report Var(flag_tree_copyrename) Optimization
2119 Replace SSA temporaries with better names in copies
2122 Common Report Var(flag_tree_copy_prop) Optimization
2123 Enable copy propagation on trees
2125 ftree-store-copy-prop
2127 Does nothing. Preserved for backward compatibility.
2130 Common Report Var(flag_tree_cselim) Init(2) Optimization
2131 Transform condition stores into unconditional ones
2133 ftree-switch-conversion
2134 Common Report Var(flag_tree_switch_conversion) Optimization
2135 Perform conversions of switch initializations.
2138 Common Report Var(flag_tree_dce) Optimization
2139 Enable SSA dead code elimination optimization on trees
2141 ftree-dominator-opts
2142 Common Report Var(flag_tree_dom) Optimization
2143 Enable dominator optimizations
2146 Common Report Var(flag_tree_tail_merge) Optimization
2147 Enable tail merging on trees
2150 Common Report Var(flag_tree_dse) Optimization
2151 Enable dead store elimination
2154 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2155 Enable forward propagation on trees
2158 Common Report Var(flag_tree_fre) Optimization
2159 Enable Full Redundancy Elimination (FRE) on trees
2162 Common Report Var(flag_optimize_strlen) Optimization
2163 Enable string length optimizations on trees
2165 ftree-loop-distribution
2166 Common Report Var(flag_tree_loop_distribution) Optimization
2167 Enable loop distribution on trees
2169 ftree-loop-distribute-patterns
2170 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2171 Enable loop distribution for patterns transformed into a library call
2174 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2175 Enable loop invariant motion on trees
2178 Common Alias(floop-interchange)
2179 Enable loop interchange transforms. Same as -floop-interchange
2182 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2183 Create canonical induction variables in loops
2186 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2187 Enable loop optimizations on tree level
2189 ftree-parallelize-loops=
2190 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2191 Enable automatic parallelization of loops
2194 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2195 Enable hoisting loads from conditional pointers.
2198 Common Report Var(flag_tree_pre) Optimization
2199 Enable SSA-PRE optimization on trees
2202 Common Report Var(flag_tree_pta) Init(1) Optimization
2203 Perform function-local points-to analysis on trees.
2206 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2207 Enable reassociation on tree level
2211 Does nothing. Preserved for backward compatibility.
2214 Common Report Var(flag_tree_sink) Optimization
2215 Enable SSA code sinking on trees
2218 Common Report Var(flag_tree_sra) Optimization
2219 Perform scalar replacement of aggregates
2222 Common Report Var(flag_tree_ter) Optimization
2223 Replace temporary expressions in the SSA->normal pass
2226 Common Report Var(flag_tree_live_range_split) Optimization
2227 Perform live range splitting during the SSA->normal pass
2230 Common Report Var(flag_tree_vrp) Init(0) Optimization
2231 Perform Value Range Propagation on trees
2233 fstrict-enum-precision
2234 Common Report Var(flag_strict_enum_precision) Init(1) Optimization
2235 Perform transformations based on enum precision
2238 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2239 Compile whole compilation unit at a time
2242 Common Report Var(flag_unroll_loops) Optimization
2243 Perform loop unrolling when iteration count is known
2246 Common Report Var(flag_unroll_all_loops) Optimization
2247 Perform loop unrolling for all loops
2249 funroll-codesize-limit
2250 Common Report Var(flag_unroll_codesize_limit) Init(1) Optimization
2251 Limit non-const non-FP loop unrolling under profile estimates of large code footprint
2253 ; Nonzero means that loop optimizer may assume that the induction variables
2254 ; that control loops do not overflow and that the loops with nontrivial
2255 ; exit condition are not infinite
2256 funsafe-loop-optimizations
2257 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2258 Allow loop optimizations to assume that the loops behave in normal way
2261 Common Report Var(flag_associative_math) SetByCombined
2262 Allow optimization for floating-point arithmetic which may change the
2263 result of the operation due to rounding.
2266 Common Report Var(flag_reciprocal_math) SetByCombined
2267 Same as -fassociative-math for expressions which include division.
2269 ; Nonzero means that unsafe floating-point math optimizations are allowed
2270 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2271 ; are allowed to assume that their arguments and results are "normal"
2272 ; (e.g., nonnegative for SQRT).
2273 funsafe-math-optimizations
2274 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2275 Allow math optimizations that may violate IEEE or ISO standards
2278 Common Report Var(flag_unswitch_loops) Optimization
2279 Perform loop unswitching
2282 Common Report Var(flag_unwind_tables) Optimization
2283 Just generate unwind tables for exception handling
2286 Common Joined Undocumented
2291 ; Positive if we should track variables, negative if we should run
2292 ; the var-tracking pass only to discard debug annotations, zero if
2293 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2294 ; will be set according to optimize, debug_info_level and debug_hooks
2295 ; in process_options ().
2297 Common Report Var(flag_var_tracking) Init(2) Optimization
2298 Perform variable tracking
2300 ; Positive if we should track variables at assignments, negative if
2301 ; we should run the var-tracking pass only to discard debug
2302 ; annotations. When flag_var_tracking_assignments ==
2303 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2304 fvar-tracking-assignments
2305 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2306 Perform variable tracking by annotating assignments
2308 ; Nonzero if we should toggle flag_var_tracking_assignments after
2309 ; processing options and computing its default. */
2310 fvar-tracking-assignments-toggle
2311 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2312 Toggle -fvar-tracking-assignments
2314 fvar-tracking-uninit
2315 Common Report Var(flag_var_tracking_uninit) Optimization
2316 Perform variable tracking and also tag variables that are uninitialized
2319 Common Report Var(flag_tree_vectorize) Optimization
2320 Enable loop vectorization on trees
2323 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
2324 Enable basic block vectorization (SLP) on trees
2327 Common Report Var(flag_vect_cost_model) Optimization
2328 Enable use of cost model in vectorization
2330 ftree-vect-loop-version
2331 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
2332 Enable loop versioning when doing loop vectorization on trees
2334 ftree-vectorizer-verbose=
2335 Common RejectNegative Joined UInteger
2336 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
2339 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2340 Enable copy propagation of scalar-evolution information.
2342 ; -fverbose-asm causes extra commentary information to be produced in
2343 ; the generated assembly code (to make it more readable). This option
2344 ; is generally only of use to those who actually need to read the
2345 ; generated assembly code (perhaps while debugging the compiler itself).
2346 ; -fno-verbose-asm, the default, causes the extra information
2347 ; to not be added and is useful when comparing two assembler files.
2349 Common Report Var(flag_verbose_asm)
2350 Add extra commentary to assembler output
2353 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2354 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2357 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2360 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2363 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2366 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2369 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2372 Common Report Var(flag_value_profile_transformations) Optimization
2373 Use expression value profiles in optimizations
2376 Common Report Var(flag_web) Init(2) Optimization
2377 Construct webs and split unrelated uses of single variable
2379 ftree-builtin-call-dce
2380 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2381 Enable conditional dead code elimination for builtin calls
2383 fclone-hot-version-paths
2384 Common Report Var(flag_clone_hot_version_paths) Init(0)
2385 Enable cloning and hoisting of hot multiversioned paths
2388 Common Report Var(flag_whole_program) Init(0) Optimization
2389 Perform whole program optimizations
2392 Common Report Var(flag_wrapv) Optimization
2393 Assume signed arithmetic overflow wraps around
2395 fzero-initialized-in-bss
2396 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2397 Put zero initialized data in the bss section
2400 Common JoinedOrMissing
2401 Generate debug information in default format
2404 Common JoinedOrMissing Negative(gdwarf-)
2405 Generate debug information in COFF format
2408 Common Joined UInteger Var(dwarf_version) Init(2) Negative(gstabs)
2409 Generate debug information in DWARF v2 (or later) format
2412 Common JoinedOrMissing
2413 Generate debug information in default extended format
2416 Common RejectNegative
2417 Generate debug information at level 1 with minimal line table
2420 Common RejectNegative Var(debug_generate_pub_sections, 0) Init(-1)
2421 Don't generate DWARF pubnames and pubtypes sections.
2424 Common RejectNegative Var(debug_generate_pub_sections, 1)
2425 Generate DWARF pubnames and pubtypes sections.
2427 gno-record-gcc-switches
2428 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(0)
2429 Don't record gcc command line switches in DWARF DW_AT_producer.
2431 grecord-gcc-switches
2432 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2433 Record gcc command line switches in DWARF DW_AT_producer.
2436 Common JoinedOrMissing Negative(gstabs+)
2437 Generate debug information in STABS format
2440 Common JoinedOrMissing Negative(gvms)
2441 Generate debug information in extended STABS format
2444 Common RejectNegative Var(dwarf_strict,0) Init(-1)
2445 Emit DWARF additions beyond selected version
2448 Common Report RejectNegative Var(dwarf_strict,1)
2449 Don't emit DWARF additions beyond selected version
2452 Common Report Var(flag_gtoggle)
2453 Toggle debug information generation
2456 Common JoinedOrMissing Negative(gxcoff)
2457 Generate debug information in VMS format
2460 Common JoinedOrMissing Negative(gxcoff+)
2461 Generate debug information in XCOFF format
2464 Common JoinedOrMissing Negative(gcoff)
2465 Generate debug information in extended XCOFF format
2468 Driver Joined Separate
2471 Common Joined Var(plugindir_string) Init(0)
2472 -iplugindir=<dir> Set <dir> to be the default plugin directory
2475 Driver Joined Separate
2480 no-canonical-prefixes
2496 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2497 -o <file> Place output into <file>
2500 Common Var(profile_flag)
2501 Enable function profiling
2504 Driver Var(pass_exit_codes)
2507 Common Var(pedantic)
2508 Issue warnings needed for strict compliance to the standard
2511 Common Var(flag_pedantic_errors)
2512 Like -pedantic but issue them as errors
2518 Driver Var(use_pipes)
2521 Driver JoinedOrMissing Var(print_file_name)
2523 print-libgcc-file-name
2526 print-multi-directory
2527 Driver Var(print_multi_directory)
2530 Driver Var(print_multi_lib)
2532 print-multi-os-directory
2533 Driver Var(print_multi_os_directory)
2536 Driver JoinedOrMissing Var(print_prog_name)
2539 Driver Var(print_search_dirs)
2542 Driver Var(print_sysroot)
2544 print-sysroot-headers-suffix
2545 Driver Var(print_sysroot_headers_suffix)
2548 Common Var(quiet_flag) RejectDriver
2549 Do not display functions compiled or elapsed time
2567 Driver Var(report_times)
2570 Driver JoinedOrMissing
2573 Driver Joined Separate
2577 ; C option, but driver must not handle as "-u ndef".
2580 Common Driver Var(verbose_flag)
2581 Enable verbose output
2584 Common Var(version_flag) RejectDriver
2585 Display the compiler's version
2588 Common Var(inhibit_warnings)
2592 Driver Separate Var(wrapper_string)
2595 Driver Joined Separate
2598 Driver RejectNegative Negative(pie)
2599 Create a shared library
2605 Driver Separate Alias(specs=)
2618 ; Documented for Fortran, but always accepted by driver.
2625 ; Documented for Go, but always accepted by driver.
2631 Driver RejectNegative Negative(shared)
2632 Create a position independent executable
2635 Driver Joined Separate
2637 ; This comment is to ensure we retain the blank line above.