path: root/gcc/common.opt

; Options for the language- and target-independent parts of the compiler.

; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
; Free Software Foundation, Inc.
;
; This file is part of GCC.
;
; GCC is free software; you can redistribute it and/or modify it under
; the terms of the GNU General Public License as published by the Free
; Software Foundation; either version 3, or (at your option) any later
; version.
;
; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
; WARRANTY; without even the implied warranty of MERCHANTABILITY or
; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
; for more details.
;
; You should have received a copy of the GNU General Public License
; along with GCC; see the file COPYING3.  If not see
; <http://www.gnu.org/licenses/>.

; See the GCC internals manual (options.texi) for a description of this file's format.

; Please try to keep this file in ASCII collating order.

Variable
int target_flags

Variable
int optimize

Variable
int optimize_size

; Not used directly to control optimizations, only to save -Ofast
; setting for "optimize" attributes.
Variable
int optimize_fast

; 0 means straightforward implementation of complex divide acceptable.
; 1 means wide ranges of inputs must work for complex divide.
; 2 means C99-like requirements for complex multiply and divide.
Variable
int flag_complex_method = 1

; Nonzero if subexpressions must be evaluated from left-to-right.
Variable
int flag_evaluation_order = 0

; Language specific warning pass for unused results.
Variable
bool flag_warn_unused_result = false

Variable
int *param_values

; Nonzero if we should write GIMPLE bytecode for link-time optimization.
Variable
int flag_generate_lto

; True to warn about any objects definitions whose size is larger
; than N bytes.  Also want about function definitions whose returned
; values are larger than N bytes, where N is 'larger_than_size'.
Variable
bool warn_larger_than

Variable
HOST_WIDE_INT larger_than_size

; True to warn about any function whose frame size is larger
; than N bytes.
Variable
bool warn_frame_larger_than

Variable
HOST_WIDE_INT frame_larger_than_size

; Nonzero means we should be saving declaration info into a .X file.
Variable
int flag_gen_aux_info = 0

; Nonzero if we are compiling code for a shared library, zero for
; executable.
Variable
int flag_shlib

; These two are really VEC(char_p,heap) *.

Variable
void *flag_instrument_functions_exclude_functions

Variable
void *flag_instrument_functions_exclude_files

; Generic structs (e.g. templates not explicitly specialized)
; may not have a compilation unit associated with them, and so
; may need to be treated differently from ordinary structs.
;
; Structs only handled by reference (indirectly), will also usually
; not need as much debugging information.

Variable
enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }

Variable
enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }

; True if we should exit after parsing options.
Variable
bool exit_after_options

; Type(s) of debugging information we are producing (if any).  See
; flag-types.h for the definitions of the different possible types of
; debugging information.
Variable
enum debug_info_type write_symbols = NO_DEBUG

; Level of debugging information we are producing.  See flag-types.h
; for the definitions of the different possible levels.
Variable
enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE

; Nonzero means use GNU-only extensions in the generated symbolic
; debugging information.  Currently, this only has an effect when
; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
Variable
bool use_gnu_debug_info_extensions

; Original value of maximum field alignment in bytes, specified via
; -fpack-struct=<value>.
Variable
unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT

Variable
enum vect_verbosity_levels user_vect_verbosity_level = MAX_VERBOSITY_LEVEL

; Type of stack check.
Variable
enum stack_check_type flag_stack_check = NO_STACK_CHECK

; True if stack usage information needs to be computed.
Variable
bool flag_stack_usage_info = false

; -dA causes debug commentary information to be produced in
; the generated assembly code (to make it more readable).  This option
; is generally only of use to those who actually need to read the
; generated assembly code (perhaps while debugging the compiler itself).
; Currently, this switch is only used by dwarf2out.c; however, it is intended
; to be a catchall for printing debug information in the assembler file.
Variable
int flag_debug_asm

; -dP causes the rtl to be emitted as a comment in assembly.
Variable
int flag_dump_rtl_in_asm

; Whether -da was passed (used only in handle_common_deferred_options).
Variable
bool flag_dump_all_passed

; Other flags saying which kinds of debugging dump have been requested.

Variable
int rtl_dump_and_exit

Variable
int flag_print_asm_name

Variable
enum graph_dump_types graph_dump_format = no_graph

; Name of top-level original source file (what was input to cpp).
; This comes from the #-command at the beginning of the actual input.
; If there isn't any there, then this is the cc1 input file name.
Variable
const char *main_input_filename

; Pointer to base name in main_input_filename, with directories and a
; single final extension removed, and the length of this base
; name.

Variable
const char *main_input_basename

Variable
int main_input_baselength

; Which options have been printed by --help.
Variable
char *help_printed

; Which enums have been printed by --help.  0 = not printed, no
; relevant options seen, 1 = relevant option seen, not yet printed, 2
; = printed.
Variable
char *help_enum_printed

; The number of columns for --help output.
Variable
unsigned int help_columns

; Whether this options structure has been through finish_options
Variable
bool flag_opts_finished

###
Driver

-assemble
Driver Alias(S)

-compile
Driver Alias(c)

-coverage
Driver Alias(coverage)

-debug
Common Alias(g)

-dump
Common Separate Alias(d)

-dump=
Common Joined Alias(d)

-dumpbase
Common Separate Alias(dumpbase)

-dumpdir
Common Separate Alias(dumpdir)

-entry
Driver Separate Alias(e)

-entry=
Driver Joined Alias(e)

-extra-warnings
Common Warning Alias(Wextra)

-for-assembler
Driver Separate Alias(Xassembler)

-for-assembler=
Driver JoinedOrMissing Alias(Xassembler)

-for-linker
Driver Separate Alias(Xlinker)

-for-linker=
Driver JoinedOrMissing Alias(Xlinker)

-force-link
Driver Separate Alias(u)

-force-link=
Driver Joined Alias(u)

-help
Common Driver Var(help_flag)
Display this information

-help=
Common Driver Report Joined
--help=<class>	Display descriptions of a specific class of options.  <class> is one or more of optimizers, target, warnings, undocumented, params

-language
Driver Separate Alias(x)

-language=
Driver Joined Alias(x)

-library-directory
Driver Separate Alias(L)

-library-directory=
Driver Joined Alias(L)

-no-canonical-prefixes
Driver Alias(no-canonical-prefixes)

-no-standard-libraries
Driver Alias(nostdlib)

-no-warnings
Common Alias(w)

-optimize
Common Alias(O)

-output
Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)

-output=
Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)

-pass-exit-codes
Driver Alias(pass-exit-codes)

-pedantic
Common Alias(pedantic)

-pedantic-errors
Common Alias(pedantic-errors)

-pie
Common Alias(pie)

-pipe
Driver Alias(pipe)

-prefix
Driver Separate Alias(B)

-prefix=
Driver JoinedOrMissing Alias(B)

-preprocess
Driver Alias(E)

-print-file-name
Driver Separate Alias(print-file-name=)

-print-file-name=
Driver JoinedOrMissing Alias(print-file-name=)

-print-libgcc-file-name
Driver Alias(print-libgcc-file-name)

-print-multi-directory
Driver Alias(print-multi-directory)

-print-multi-lib
Driver Alias(print-multi-lib)

-print-multi-os-directory
Driver Alias(print-multi-os-directory)

-print-prog-name
Driver Separate Alias(print-prog-name=)

-print-prog-name=
Driver JoinedOrMissing Alias(print-prog-name=)

-print-search-dirs
Driver Alias(print-search-dirs)

-print-sysroot
Driver Alias(print-sysroot)

-print-sysroot-headers-suffix
Driver Alias(print-sysroot-headers-suffix)

-profile
Common Alias(p)

-save-temps
Driver Alias(save-temps)

-shared
Common Alias(shared)

-specs
Driver Separate Alias(specs=)

-specs=
Driver Joined Alias(specs=)

-static
Driver Alias(static)

-symbolic
Driver Alias(symbolic)

-target-help
Common Driver
Alias for --help=target

-time
Driver Alias(time)

-verbose
Driver Alias(v)

;; The driver used to convert options such as --help into forms such
;; as -fhelp; the following four entries are for compatibility with
;; any direct uses of those (undocumented) -f forms
fhelp
Common Driver Alias(-help)

fhelp=
Common Driver Joined Alias(-help=)

ftarget-help
Common Driver Alias(-target-help)

fversion
Common Driver Alias(-version)

-param
Common Separate
--param <param>=<value>	Set parameter <param> to value.  See below for a complete list of parameters

-param=
Common Joined Alias(-param)

-sysroot
Driver Separate Alias(-sysroot=)

-sysroot=
Driver JoinedOrMissing

-version
Common Driver

B
Driver Joined Separate

E
Driver

L
Driver Joined Separate

N
Driver

O
Common JoinedOrMissing Optimization
-O<number>	Set optimization level to <number>

Os
Common Optimization
Optimize for space rather than speed

Ofast
Common Optimization
Optimize for speed disregarding exact standards compliance

Q
Driver

Qn
Driver Negative(Qy)

Qy
Driver Negative(Qn)

R
Driver Joined Separate

S
Driver

T
Driver Joined Separate

Tbss
Driver Separate

Tbss=
Driver Joined

Tdata
Driver Separate

Tdata=
Driver Joined

Ttext
Driver Separate

Ttext=
Driver Joined

W
Common RejectNegative Warning Alias(Wextra)
This switch is deprecated; use -Wextra instead

Wa,
Driver JoinedOrMissing

Wl,
Driver JoinedOrMissing

Wp,
Driver JoinedOrMissing

Waggregate-return
Common Var(warn_aggregate_return) Warning
Warn about returning structures, unions or arrays

Warray-bounds
Common Var(warn_array_bounds) Warning
Warn if an array is accessed out of bounds

Wattributes
Common Var(warn_attributes) Init(1) Warning
Warn about inappropriate attribute usage

Wcast-align
Common Var(warn_cast_align) Warning
Warn about pointer casts which increase alignment

Wcpp
Common Var(warn_cpp) Init(1) Warning
Warn when a #warning directive is encountered

Wdeprecated-declarations
Common Var(warn_deprecated_decl) Init(1) Warning
Warn about uses of __attribute__((deprecated)) declarations

Wdisabled-optimization
Common Var(warn_disabled_optimization) Warning
Warn when an optimization pass is disabled

Werror
Common Var(warnings_are_errors)
Treat all warnings as errors

Werror=
Common Joined
Treat specified warning as error

Wextra
Common Var(extra_warnings) Warning
Print extra (possibly unwanted) warnings

Wfatal-errors
Common Var(flag_fatal_errors)
Exit on the first error occurred

Wframe-larger-than=
Common RejectNegative Joined UInteger
-Wframe-larger-than=<number>	Warn if a function's stack frame requires more than <number> bytes

Winline
Common Var(warn_inline) Warning
Warn when an inlined function cannot be inlined

Wlarger-than-
Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)

Wlarger-than=
Common RejectNegative Joined UInteger Warning
-Wlarger-than=<number>	Warn if an object is larger than <number> bytes

Wunsafe-loop-optimizations
Common Var(warn_unsafe_loop_optimizations) Warning
Warn if the loop cannot be optimized due to nontrivial assumptions.

Wmissing-noreturn
Common Var(warn_missing_noreturn) Warning
Warn about functions which might be candidates for __attribute__((noreturn))

Wmudflap
Common Var(warn_mudflap) Init(1) Warning
Warn about constructs not instrumented by -fmudflap

Woverflow
Common Var(warn_overflow) Init(1) Warning
Warn about overflow in arithmetic expressions

Wpacked
Common Var(warn_packed) Warning
Warn when the packed attribute has no effect on struct layout

Wpadded
Common Var(warn_padded) Warning
Warn when padding is required to align structure members

Wshadow
Common Var(warn_shadow) Warning
Warn when one local variable shadows another

Wstack-protector
Common Var(warn_stack_protect) Warning
Warn when not issuing stack smashing protection for some reason

Wstack-usage=
Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
Warn if stack usage might be larger than specified amount

Wstrict-aliasing
Common Warning
Warn about code which might break strict aliasing rules

Wstrict-aliasing=
Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Init(-1) Warning
Warn about code which might break strict aliasing rules

Wstrict-overflow
Common Warning
Warn about optimizations that assume that signed overflow is undefined

Wstrict-overflow=
Common Joined RejectNegative UInteger Var(warn_strict_overflow) Init(-1) Warning
Warn about optimizations that assume that signed overflow is undefined

Wsuggest-attribute=const
Common Var(warn_suggest_attribute_const) Warning
Warn about functions which might be candidates for __attribute__((const))

Wsuggest-attribute=pure
Common Var(warn_suggest_attribute_pure) Warning
Warn about functions which might be candidates for __attribute__((pure))

Wsuggest-attribute=noreturn
Common Var(warn_suggest_attribute_noreturn) Warning
Warn about functions which might be candidates for __attribute__((noreturn))

Wswitch
Common Var(warn_switch) Warning
Warn about enumerated switches, with no default, missing a case

Wswitch-default
Common Var(warn_switch_default) Warning
Warn about enumerated switches missing a \"default:\" statement

Wswitch-enum
Common Var(warn_switch_enum) Warning
Warn about all enumerated switches missing a specific case

Wsystem-headers
Common Var(warn_system_headers) Warning
Do not suppress warnings from system headers

Wtrampolines
Common Var(warn_trampolines) Warning
Warn whenever a trampoline is generated

Wtype-limits
Common Var(warn_type_limits) Init(-1) Warning
Warn if a comparison is always true or always false due to the limited range of the data type

Wuninitialized
Common Var(warn_uninitialized) Init(-1) Warning
Warn about uninitialized automatic variables

Wmaybe-uninitialized
Common Var(warn_maybe_uninitialized) Warning
Warn about maybe uninitialized automatic variables

Wunreachable-code
Common Ignore
Does nothing. Preserved for backward compatibility.

Wunused
Common Var(warn_unused) Init(0) Warning
Enable all -Wunused- warnings

Wunused-but-set-parameter
Common Var(warn_unused_but_set_parameter) Init(-1) Warning
Warn when a function parameter is only set, otherwise unused

Wunused-but-set-variable
Common Var(warn_unused_but_set_variable) Init(-1) Warning
Warn when a variable is only set, otherwise unused

Wunused-function
Common Var(warn_unused_function) Init(-1) Warning
Warn when a function is unused

Wunused-label
Common Var(warn_unused_label) Init(-1) Warning
Warn when a label is unused

Wunused-parameter
Common Var(warn_unused_parameter) Init(-1) Warning
Warn when a function parameter is unused

Wunused-value
Common Var(warn_unused_value) Init(-1) Warning
Warn when an expression value is unused

Wunused-variable
Common Var(warn_unused_variable) Init(-1) Warning
Warn when a variable is unused

Wcoverage-mismatch
Common Var(warn_coverage_mismatch) Init(1) Warning
Warn in case profiles in -fprofile-use do not match

Xassembler
Driver Separate

Xlinker
Driver Separate

Xpreprocessor
Driver Separate

Z
Driver

aux-info
Common Separate Var(aux_info_file_name)
-aux-info <file>	Emit declaration information into <file>

aux-info=
Common Joined Alias(aux-info)

auxbase
Common Separate RejectDriver Var(aux_base_name)

auxbase-strip
Common Separate RejectDriver

coverage
Driver

c
Driver

d
Common Joined
-d<letters>	Enable dumps from specific passes of the compiler

dumpbase
Common Separate Var(dump_base_name)
-dumpbase <file>	Set the file basename to be used for dumps

dumpdir
Common Separate Var(dump_dir_name)
-dumpdir <dir>	Set the directory name to be used for dumps

dumpmachine
Driver

dumpspecs
Driver

dumpversion
Driver

e
Driver Joined Separate

; This option has historically been passed down to the linker by an
; accident of a %{e*} spec, so ensure it continues to be passed down
; as a single option.  The supported option for this purpose is
; -rdynamic.  See PR 47390.
export-dynamic
Driver Undocumented

; The version of the C++ ABI in use.  The following values are allowed:
;
; 0: The version of the ABI believed most conformant with the C++ ABI
;    specification.  This ABI may change as bugs are discovered and fixed.
;    Therefore, 0 will not necessarily indicate the same ABI in different
;    versions of G++.
;
; 1: The version of the ABI first used in G++ 3.2.
;
; 2: The version of the ABI first used in G++ 3.4 (and current default).
;
; 3: The version of the ABI that fixes the missing underscore
;    in template non-type arguments of pointer type.
;
; 4: The version of the ABI that introduces unambiguous mangling of
;    vector types.  First selectable in G++ 4.5.
;
; 5: The version of the ABI that ignores attribute const/noreturn
;    in function pointer mangling, and corrects mangling of decltype and
;    function parameters used in other parameters and the return type.
;    First selectable in G++ 4.6.
;
; 6: The version of the ABI that doesn't promote scoped enums to int.
;    First selectable in G++ 4.7.
;
; Additional positive integers will be assigned as new versions of
; the ABI become the default version of the ABI.
fabi-version=
Common Joined RejectNegative UInteger Var(flag_abi_version) Init(2)

falign-functions
Common Report Var(align_functions,0) Optimization UInteger
Align the start of functions

falign-functions=
Common RejectNegative Joined UInteger Var(align_functions)

falign-jumps
Common Report Var(align_jumps,0) Optimization UInteger
Align labels which are only reached by jumping

falign-jumps=
Common RejectNegative Joined UInteger Var(align_jumps)

falign-labels
Common Report Var(align_labels,0) Optimization UInteger
Align all labels

falign-labels=
Common RejectNegative Joined UInteger Var(align_labels)

falign-loops
Common Report Var(align_loops,0) Optimization UInteger
Align the start of loops

falign-loops=
Common RejectNegative Joined UInteger Var(align_loops)

fargument-alias
Common Ignore
Does nothing. Preserved for backward compatibility.

fargument-noalias
Common Ignore
Does nothing. Preserved for backward compatibility.

fargument-noalias-global
Common Ignore
Does nothing. Preserved for backward compatibility.

fargument-noalias-anything
Common Ignore
Does nothing. Preserved for backward compatibility.

fasynchronous-unwind-tables
Common Report Var(flag_asynchronous_unwind_tables) Optimization
Generate unwind tables that are exact at each instruction boundary

fauto-inc-dec
Common Report Var(flag_auto_inc_dec) Init(1)
Generate auto-inc/dec instructions

; -fcheck-bounds causes gcc to generate array bounds checks.
; For C, C++ and ObjC: defaults off.
; For Java: defaults to on.
; For Fortran: defaults to off.
fbounds-check
Common Report Var(flag_bounds_check)
Generate code to check bounds before indexing arrays

fbranch-count-reg
Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
Replace add, compare, branch with branch on count register

fbranch-probabilities
Common Report Var(flag_branch_probabilities) Optimization
Use profiling information for branch probabilities

fbranch-target-load-optimize
Common Report Var(flag_branch_target_load_optimize) Optimization
Perform branch target load optimization before prologue / epilogue threading

fbranch-target-load-optimize2
Common Report Var(flag_branch_target_load_optimize2) Optimization
Perform branch target load optimization after prologue / epilogue threading

fbtr-bb-exclusive
Common Report Var(flag_btr_bb_exclusive) Optimization
Restrict target load migration not to re-use registers in any basic block

fcall-saved-
Common Joined RejectNegative Var(common_deferred_options) Defer
-fcall-saved-<register>	Mark <register> as being preserved across functions

fcall-used-
Common Joined RejectNegative Var(common_deferred_options) Defer
-fcall-used-<register>	Mark <register> as being corrupted by function calls

; Nonzero for -fcaller-saves: allocate values in regs that need to
; be saved across function calls, if that produces overall better code.
; Optional now, so people can test it.
fcaller-saves
Common Report Var(flag_caller_saves) Optimization
Save registers around function calls

fcheck-data-deps
Common Report Var(flag_check_data_deps)
Compare the results of several data dependence analyzers.

fcombine-stack-adjustments
Common Report Var(flag_combine_stack_adjustments) Optimization
Looks for opportunities to reduce stack adjustments and stack references.

fcommon
Common Report Var(flag_no_common,0) Optimization
Do not put uninitialized globals in the common section

fcompare-debug
Driver
; Converted by the driver to -fcompare-debug= options.

fcompare-debug=
Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
-fcompare-debug[=<opts>]	Compile with and without e.g. -gtoggle, and compare the final-insns dump

fcompare-debug-second
Common Driver RejectNegative Var(flag_compare_debug)
Run only the second compilation of -fcompare-debug

fcompare-elim
Common Report Var(flag_compare_elim_after_reload) Optimization
Perform comparison elimination after register allocation has finished

fconserve-stack
Common Var(flag_conserve_stack) Optimization
Do not perform optimizations increasing noticeably stack usage

fcprop-registers
Common Report Var(flag_cprop_registers) Optimization
Perform a register copy-propagation optimization pass

fcrossjumping
Common Report Var(flag_crossjumping) Optimization
Perform cross-jumping optimization

fcse-follow-jumps
Common Report Var(flag_cse_follow_jumps) Optimization
When running CSE, follow jumps to their targets

fcse-skip-blocks
Common Ignore
Does nothing.  Preserved for backward compatibility.

fcx-limited-range
Common Report Var(flag_cx_limited_range) Optimization SetByCombined
Omit range reduction step when performing complex division

fcx-fortran-rules
Common Report Var(flag_cx_fortran_rules) Optimization
Complex multiplication and division follow Fortran rules

fdata-sections
Common Report Var(flag_data_sections) Optimization
Place data items into their own section

fdbg-cnt-list
Common Report Var(common_deferred_options) Defer
List all available debugging counters with their limits and counts.

fdbg-cnt=
Common RejectNegative Joined Var(common_deferred_options) Defer
-fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...]	Set the debug counter limit.   

fdebug-prefix-map=
Common Joined RejectNegative Var(common_deferred_options) Defer
Map one directory name to another in debug information

fdebug-types-section
Common Report Var(flag_debug_types_section) Init(1)
Output .debug_types section when using DWARF v4 debuginfo.

; Nonzero for -fdefer-pop: don't pop args after each function call
; instead save them up to pop many calls' args with one insns.
fdefer-pop
Common Report Var(flag_defer_pop) Optimization
Defer popping functions args from stack until later

fdelayed-branch
Common Report Var(flag_delayed_branch) Optimization
Attempt to fill delay slots of branch instructions

fdelete-null-pointer-checks
Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
Delete useless null pointer checks

fdevirtualize
Common Report Var(flag_devirtualize) Optimization
Try to convert virtual calls to direct ones.

fdiagnostics-show-location=
Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
-fdiagnostics-show-location=[once|every-line]	How often to emit source location at the beginning of line-wrapped diagnostics

; Required for these enum values.
SourceInclude
pretty-print.h

Enum
Name(diagnostic_prefixing_rule) Type(int)

EnumValue
Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)

EnumValue
Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)

fdiagnostics-show-option
Common Var(flag_diagnostics_show_option) Init(1)
Amend appropriate diagnostic messages with the command line option that controls them

fdisable-
Common Joined RejectNegative Var(common_deferred_options) Defer
-fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass

fenable-
Common Joined RejectNegative Var(common_deferred_options) Defer
-fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass

fdump-
Common Joined RejectNegative Var(common_deferred_options) Defer
-fdump-<type>	Dump various compiler internals to a file

fdump-final-insns
Driver RejectNegative

fdump-final-insns=
Common RejectNegative Joined Var(flag_dump_final_insns)
-fdump-final-insns=filename	Dump to filename the insns at the end of translation

fdump-go-spec=
Common RejectNegative Joined Var(flag_dump_go_spec)
-fdump-go-spec=filename	Write all declarations to file as Go code

fdump-noaddr
Common Report Var(flag_dump_noaddr)
Suppress output of addresses in debugging dumps

fdump-passes
Common Var(flag_dump_passes) Init(0)
Dump optimization passes

fdump-unnumbered
Common Report Var(flag_dump_unnumbered)
Suppress output of instruction numbers, line number notes and addresses in debugging dumps

fdump-unnumbered-links
Common Report Var(flag_dump_unnumbered_links)
Suppress output of previous and next insn numbers in debugging dumps

fdwarf2-cfi-asm
Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
Enable CFI tables via GAS assembler directives.

fearly-inlining
Common Report Var(flag_early_inlining) Init(1) Optimization
Perform early inlining

feliminate-dwarf2-dups
Common Report Var(flag_eliminate_dwarf2_dups)
Perform DWARF2 duplicate elimination

fipa-sra
Common Report Var(flag_ipa_sra) Init(0) Optimization
Perform interprocedural reduction of aggregates

feliminate-unused-debug-symbols
Common Report Var(flag_debug_only_used_symbols)
Perform unused type elimination in debug info

feliminate-unused-debug-types
Common Report Var(flag_eliminate_unused_debug_types) Init(1)
Perform unused type elimination in debug info

femit-class-debug-always
Common Report Var(flag_emit_class_debug_always) Init(0)
Do not suppress C++ class debug information.

fexceptions
Common Report Var(flag_exceptions) Optimization
Enable exception handling

fexpensive-optimizations
Common Report Var(flag_expensive_optimizations) Optimization
Perform a number of minor, expensive optimizations

fexcess-precision=
Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
-fexcess-precision=[fast|standard]	Specify handling of excess floating-point precision

Enum
Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)

EnumValue
Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)

EnumValue
Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)

ffast-math
Common

ffinite-math-only
Common Report Var(flag_finite_math_only) Optimization SetByCombined
Assume no NaNs or infinities are generated

ffixed-
Common Joined RejectNegative Var(common_deferred_options) Defer
-ffixed-<register>	Mark <register> as being unavailable to the compiler

ffloat-store
Common Report Var(flag_float_store) Optimization
Don't allocate floats and doubles in extended-precision registers

fforce-addr
Common Ignore
Does nothing.  Preserved for backward compatibility.

fforward-propagate
Common Report Var(flag_forward_propagate) Optimization
Perform a forward propagation pass on RTL

ffp-contract=
Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
-ffp-contract=[off|on|fast] Perform floating-point expression contraction.

Enum
Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)

EnumValue
Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)

; Not implemented, fall back to conservative FP_CONTRACT_OFF.
EnumValue
Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)

EnumValue
Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)

; Nonzero means don't put addresses of constant functions in registers.
; Used for compiling the Unix kernel, where strange substitutions are
; done on the assembly output.
ffunction-cse
Common Report Var(flag_no_function_cse,0)
Allow function addresses to be held in registers

ffunction-sections
Common Report Var(flag_function_sections)
Place each function into its own section

fgcse
Common Report Var(flag_gcse) Optimization
Perform global common subexpression elimination

fgcse-lm
Common Report Var(flag_gcse_lm) Init(1) Optimization
Perform enhanced load motion during global common subexpression elimination

fgcse-sm
Common Report Var(flag_gcse_sm) Init(0) Optimization
Perform store motion after global common subexpression elimination

fgcse-las
Common Report Var(flag_gcse_las) Init(0) Optimization
Perform redundant load after store elimination in global common subexpression
elimination

fgcse-after-reload
Common Report Var(flag_gcse_after_reload) Optimization
Perform global common subexpression elimination after register allocation
has finished

; This option is not documented yet as its semantics will change.
fgraphite
Common Report Var(flag_graphite)
Enable in and out of Graphite representation

fgraphite-identity
Common Report Var(flag_graphite_identity) Optimization
Enable Graphite Identity transformation

floop-parallelize-all
Common Report Var(flag_loop_parallelize_all) Optimization
Mark all loops as parallel

floop-strip-mine
Common Report Var(flag_loop_strip_mine) Optimization
Enable Loop Strip Mining transformation

floop-interchange
Common Report Var(flag_loop_interchange) Optimization
Enable Loop Interchange transformation

floop-block
Common Report Var(flag_loop_block) Optimization
Enable Loop Blocking transformation

floop-flatten
Common Report Var(flag_loop_flatten) Optimization
Enable Loop Flattening transformation

fstrict-volatile-bitfields
Common Report Var(flag_strict_volatile_bitfields) Init(-1)
Force bitfield accesses to match their type width

fguess-branch-probability
Common Report Var(flag_guess_branch_prob) Optimization
Enable guessing of branch probabilities

; Nonzero means ignore `#ident' directives.  0 means handle them.
; Generate position-independent code for executables if possible
; On SVR4 targets, it also controls whether or not to emit a
; string identifying the compiler.
fident
Common Report Var(flag_no_ident,0)
Process #ident directives

fif-conversion
Common Report Var(flag_if_conversion) Optimization
Perform conversion of conditional jumps to branchless equivalents

fif-conversion2
Common Report Var(flag_if_conversion2) Optimization
Perform conversion of conditional jumps to conditional execution

ftree-loop-if-convert
Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
Convert conditional jumps in innermost loops to branchless equivalents

ftree-loop-if-convert-stores
Common Report Var(flag_tree_loop_if_convert_stores) Optimization
Also if-convert conditional jumps containing memory writes

; -finhibit-size-directive inhibits output of .size for ELF.
; This is used only for compiling crtstuff.c,
; and it may be extended to other effects
; needed for crtstuff.c on other systems.
finhibit-size-directive
Common Report Var(flag_inhibit_size_directive)
Do not generate .size directives

findirect-inlining
Common Report Var(flag_indirect_inlining)
Perform indirect inlining

; Nonzero means that functions declared `inline' will be treated
; as `static'.  Prevents generation of zillions of copies of unused
; static inline functions; instead, `inlines' are written out
; only when actually used.  Used in conjunction with -g.  Also
; does the right thing with #pragma interface.
finline
Common Report Var(flag_no_inline,0) Init(0)
Pay attention to the \"inline\" keyword

finline-small-functions
Common Report Var(flag_inline_small_functions) Optimization
Integrate simple functions into their callers when code size is known to not growth

finline-functions
Common Report Var(flag_inline_functions) Optimization
Integrate simple functions into their callers

finline-functions-called-once
Common Report Var(flag_inline_functions_called_once) Optimization
Integrate functions called once into their callers

finline-limit-
Common RejectNegative Joined Alias(finline-limit=)

finline-limit=
Common RejectNegative Joined UInteger
-finline-limit=<number>	Limit the size of inlined functions to <number>

finstrument-functions
Common Report Var(flag_instrument_function_entry_exit)
Instrument function entry and exit with profiling calls

finstrument-functions-exclude-function-list=
Common RejectNegative Joined
-finstrument-functions-exclude-function-list=name,...  Do not instrument listed functions

finstrument-functions-exclude-file-list=
Common RejectNegative Joined
-finstrument-functions-exclude-file-list=filename,...  Do not instrument functions listed in files

fipa-cp
Common Report Var(flag_ipa_cp) Optimization
Perform Interprocedural constant propagation

fipa-cp-clone
Common Report Var(flag_ipa_cp_clone) Optimization
Perform cloning to make Interprocedural constant propagation stronger

fipa-profile
Common Report Var(flag_ipa_profile) Init(0) Optimization
Perform interprocedural profile propagation

fipa-pta
Common Report Var(flag_ipa_pta) Init(0) Optimization
Perform interprocedural points-to analysis

fipa-pure-const
Common Report Var(flag_ipa_pure_const) Init(0) Optimization
Discover pure and const functions

fipa-reference
Common Report Var(flag_ipa_reference) Init(0) Optimization
Discover readonly and non addressable static variables

fipa-matrix-reorg
Common Report Var(flag_ipa_matrix_reorg) Optimization
Perform matrix layout flattening and transposing based
on profiling information.

fipa-struct-reorg
Common Ignore
Does nothing. Preserved for backward compatibility.

fira-algorithm=
Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
-fira-algorithm=[CB|priority] Set the used IRA algorithm

Enum
Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)

EnumValue
Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)

EnumValue
Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)

fira-region=
Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_MIXED)
-fira-region=[one|all|mixed] Set regions for IRA

Enum
Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)

EnumValue
Enum(ira_region) String(one) Value(IRA_REGION_ONE)

EnumValue
Enum(ira_region) String(all) Value(IRA_REGION_ALL)

EnumValue
Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)

fira-loop-pressure
Common Report Var(flag_ira_loop_pressure)
Use IRA based register pressure calculation
in RTL loop optimizations.

fira-share-save-slots
Common Report Var(flag_ira_share_save_slots) Init(1)
Share slots for saving different hard registers.

fira-share-spill-slots
Common Report Var(flag_ira_share_spill_slots) Init(1)
Share stack slots for spilled pseudo-registers.

fira-verbose=
Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
-fira-verbose=<number>	Control IRA's level of diagnostic messages.

fivopts
Common Report Var(flag_ivopts) Init(1) Optimization
Optimize induction variables on trees

fjump-tables
Common Var(flag_jump_tables) Init(1) Optimization
Use jump tables for sufficiently large switch statements

fkeep-inline-functions
Common Report Var(flag_keep_inline_functions)
Generate code for functions even if they are fully inlined

fkeep-static-consts
Common Report Var(flag_keep_static_consts) Init(1)
Emit static const variables even if they are not used

fleading-underscore
Common Report Var(flag_leading_underscore) Init(-1)
Give external symbols a leading underscore

floop-optimize
Common Ignore
Does nothing.  Preserved for backward compatibility.

flto
Common
Enable link-time optimization.

flto=
Common RejectNegative Joined Var(flag_lto)
Link-time optimization with number of parallel jobs or jobserver.

flto-partition=1to1
Common Var(flag_lto_partition_1to1)
Partition functions and vars at linktime based on object files they originate from

flto-partition=balanced
Common Var(flag_lto_partition_balanced)
Partition functions and vars at linktime into approximately same sized buckets

flto-partition=none
Common Var(flag_lto_partition_none)
Disable partioning and streaming

; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
flto-compression-level=
Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
-flto-compression-level=<number>	Use zlib compression level <number> for IL

flto-report
Common Report Var(flag_lto_report) Init(0) Optimization
Report various link-time optimization statistics

fmath-errno
Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
Set errno after built-in math functions

fmax-errors=
Common Joined RejectNegative UInteger Var(flag_max_errors)
-fmax-errors=<number>	Maximum number of errors to report

fmem-report
Common Report Var(mem_report)
Report on permanent memory allocation

; This will attempt to merge constant section constants, if 1 only
; string constants and constants from constant pool, if 2 also constant
; variables.
fmerge-all-constants
Common Report Var(flag_merge_constants,2) Init(1) Optimization
Attempt to merge identical constants and constant variables

fmerge-constants
Common Report Var(flag_merge_constants,1) Optimization
Attempt to merge identical constants across compilation units

fmerge-debug-strings
Common Report Var(flag_merge_debug_strings) Init(1)
Attempt to merge identical debug strings across compilation units

fmessage-length=
Common RejectNegative Joined UInteger
-fmessage-length=<number>	Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping

fmodulo-sched
Common Report Var(flag_modulo_sched) Optimization
Perform SMS based modulo scheduling before the first scheduling pass

fmodulo-sched-allow-regmoves
Common Report Var(flag_modulo_sched_allow_regmoves)
Perform SMS based modulo scheduling with register moves allowed

fmove-loop-invariants
Common Report Var(flag_move_loop_invariants) Init(1) Optimization
Move loop invariant computations out of loops

fmudflap
Common RejectNegative Report Var(flag_mudflap)
Add mudflap bounds-checking instrumentation for single-threaded program

fmudflapth
Common RejectNegative Report Var(flag_mudflap,2)
Add mudflap bounds-checking instrumentation for multi-threaded program

fmudflapir
Common RejectNegative Report Var(flag_mudflap_ignore_reads)
Ignore read operations when inserting mudflap instrumentation

fdce
Common Var(flag_dce) Init(1) Optimization
Use the RTL dead code elimination pass

fdse
Common Var(flag_dse) Init(1) Optimization
Use the RTL dead store elimination pass

freschedule-modulo-scheduled-loops
Common Report Var(flag_resched_modulo_sched) Optimization
Enable/Disable the traditional scheduling in loops that already passed modulo scheduling

fnon-call-exceptions
Common Report Var(flag_non_call_exceptions) Optimization
Support synchronous non-call exceptions

fomit-frame-pointer
Common Report Var(flag_omit_frame_pointer) Optimization
When possible do not generate stack frames

foptimize-register-move
Common Report Var(flag_regmove) Optimization
Do the full register move optimization pass

foptimize-sibling-calls
Common Report Var(flag_optimize_sibling_calls) Optimization
Optimize sibling and tail recursive calls

fpartial-inlining
Common Report Var(flag_partial_inlining)
Perform partial inlining

fpre-ipa-mem-report
Common Report Var(pre_ipa_mem_report)
Report on memory allocation before interprocedural optimization

fpost-ipa-mem-report
Common Report Var(post_ipa_mem_report)
Report on memory allocation before interprocedural optimization

fpack-struct
Common Report Var(flag_pack_struct) Optimization
Pack structure members together without holes

fpack-struct=
Common RejectNegative Joined UInteger Optimization
-fpack-struct=<number>	Set initial maximum structure member alignment

fpcc-struct-return
Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
Return small aggregates in memory, not registers

fpeel-loops
Common Report Var(flag_peel_loops) Optimization
Perform loop peeling

fpeephole
Common Report Var(flag_no_peephole,0) Optimization
Enable machine specific peephole optimizations

fpeephole2
Common Report Var(flag_peephole2) Optimization
Enable an RTL peephole pass before sched2

fPIC
Common Report Var(flag_pic,2)
Generate position-independent code if possible (large mode)

fPIE
Common Report Var(flag_pie,2)
Generate position-independent code for executables if possible (large mode)

fpic
Common Report Var(flag_pic,1)
Generate position-independent code if possible (small mode)

fpie
Common Report Var(flag_pie,1)
Generate position-independent code for executables if possible (small mode)

fplugin=
Common Joined RejectNegative Var(common_deferred_options) Defer
Specify a plugin to load

fplugin-arg-
Common Joined RejectNegative Var(common_deferred_options) Defer
-fplugin-arg-<name>-<key>[=<value>]	Specify argument <key>=<value> for plugin <name>

fpredictive-commoning
Common Report Var(flag_predictive_commoning) Optimization
Run predictive commoning optimization.

fprefetch-loop-arrays
Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
Generate prefetch instructions, if available, for arrays in loops

fprofile
Common Report Var(profile_flag)
Enable basic program profiling code

fprofile-arcs
Common Report Var(profile_arc_flag)
Insert arc-based program profiling code

fprofile-dir=
Common Joined RejectNegative Var(profile_data_prefix)
Set the top-level directory for storing the profile data.
The default is 'pwd'.

fprofile-correction
Common Report Var(flag_profile_correction)
Enable correction of flow inconsistent profile data input

fprofile-generate
Common
Enable common options for generating profile info for profile feedback directed optimizations

fprofile-generate=
Common Joined RejectNegative
Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=

fprofile-use
Common Var(flag_profile_use)
Enable common options for performing profile feedback directed optimizations

fprofile-use=
Common Joined RejectNegative
Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=

fprofile-values
Common Report Var(flag_profile_values)
Insert code to profile values of expressions

frandom-seed
Common Var(common_deferred_options) Defer

frandom-seed=
Common Joined RejectNegative Var(common_deferred_options) Defer
-frandom-seed=<string>	Make compile reproducible using <string>

; This switch causes the command line that was used to create an
; object file to be recorded into the object file.  The exact format
; of this recording is target and binary file format dependent.
; It is related to the -fverbose-asm switch, but that switch only
; records information in the assembler output file as comments, so
; they never reach the object file.
frecord-gcc-switches
Common Report Var(flag_record_gcc_switches)
Record gcc command line switches in the object file.

freg-struct-return
Common Report Var(flag_pcc_struct_return,0) Optimization
Return small aggregates in registers

fregmove
Common Report Var(flag_regmove) Optimization
Enables a register move optimization

frename-registers
Common Report Var(flag_rename_registers) Init(2) Optimization
Perform a register renaming optimization pass

freorder-blocks
Common Report Var(flag_reorder_blocks) Optimization
Reorder basic blocks to improve code placement

freorder-blocks-and-partition
Common Report Var(flag_reorder_blocks_and_partition) Optimization
Reorder basic blocks and partition into hot and cold sections

freorder-functions
Common Report Var(flag_reorder_functions) Optimization
Reorder functions to improve code placement

frerun-cse-after-loop
Common Report Var(flag_rerun_cse_after_loop) Optimization
Add a common subexpression elimination pass after loop optimizations

frerun-loop-opt
Common Ignore
Does nothing.  Preserved for backward compatibility.

frounding-math
Common Report Var(flag_rounding_math) Optimization SetByCombined
Disable optimizations that assume default FP rounding behavior

fsched-interblock
Common Report Var(flag_schedule_interblock) Init(1) Optimization
Enable scheduling across basic blocks

fsched-pressure
Common Report Var(flag_sched_pressure) Init(0) Optimization
Enable register pressure sensitive insn scheduling

fsched-spec
Common Report Var(flag_schedule_speculative) Init(1) Optimization
Allow speculative motion of non-loads

fsched-spec-load
Common Report Var(flag_schedule_speculative_load) Optimization
Allow speculative motion of some loads

fsched-spec-load-dangerous
Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
Allow speculative motion of more loads

fsched-verbose=
Common RejectNegative Joined UInteger Var(sched_verbose_param)
-fsched-verbose=<number>	Set the verbosity level of the scheduler

fsched2-use-superblocks
Common Report Var(flag_sched2_use_superblocks) Optimization
If scheduling post reload, do superblock scheduling

fsched2-use-traces
Common Ignore
Does nothing.  Preserved for backward compatibility.

fschedule-insns
Common Report Var(flag_schedule_insns) Optimization
Reschedule instructions before register allocation

fschedule-insns2
Common Report Var(flag_schedule_insns_after_reload) Optimization
Reschedule instructions after register allocation

; This flag should be on when a target implements non-trivial
; scheduling hooks, maybe saving some information for its own sake.
; On IA64, for example, this is used for correct bundling. 
fselective-scheduling
Common Report Var(flag_selective_scheduling) Optimization
Schedule instructions using selective scheduling algorithm

fselective-scheduling2
Common Report Var(flag_selective_scheduling2) Optimization 
Run selective scheduling after reload

fsel-sched-pipelining
Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
Perform software pipelining of inner loops during selective scheduling

fsel-sched-pipelining-outer-loops
Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
Perform software pipelining of outer loops during selective scheduling

fsel-sched-reschedule-pipelined
Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
Reschedule pipelined regions without pipelining

; sched_stalled_insns means that insns can be moved prematurely from the queue
; of stalled insns into the ready list.
fsched-stalled-insns
Common Report Var(flag_sched_stalled_insns) Optimization UInteger
Allow premature scheduling of queued insns

fsched-stalled-insns=
Common RejectNegative Joined UInteger
-fsched-stalled-insns=<number>	Set number of queued insns that can be prematurely scheduled

; sched_stalled_insns_dep controls how many recently scheduled cycles will
; be examined for a dependency on a stalled insn that is candidate for
; premature removal from the queue of stalled insns into the ready list (has
; an effect only if the flag 'sched_stalled_insns' is set).
fsched-stalled-insns-dep
Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
Set dependence distance checking in premature scheduling of queued insns

fsched-stalled-insns-dep=
Common RejectNegative Joined UInteger
-fsched-stalled-insns-dep=<number>	Set dependence distance checking in premature scheduling of queued insns

fsched-group-heuristic
Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
Enable the group heuristic in the scheduler

fsched-critical-path-heuristic
Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
Enable the critical path heuristic in the scheduler

fsched-spec-insn-heuristic
Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
Enable the speculative instruction heuristic in the scheduler

fsched-rank-heuristic
Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
Enable the rank heuristic in the scheduler

fsched-last-insn-heuristic
Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
Enable the last instruction heuristic in the scheduler

fsched-dep-count-heuristic
Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
Enable the dependent count heuristic in the scheduler

fsection-anchors
Common Report Var(flag_section_anchors) Optimization
Access data in the same section from shared anchor points

fsee
Common Ignore
Does nothing.  Preserved for backward compatibility.

fzee
Common Report Var(flag_zee) Init(0)
Eliminate redundant zero extensions on targets that support implicit extensions.

fshow-column
Common Report Var(flag_show_column) Init(1)
Show column numbers in diagnostics, when available.  Default on

fsignaling-nans
Common Report Var(flag_signaling_nans) Optimization SetByCombined
Disable optimizations observable by IEEE signaling NaNs

fsigned-zeros
Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
Disable floating point optimizations that ignore the IEEE signedness of zero

fsingle-precision-constant
Common Report Var(flag_single_precision_constant) Optimization
Convert floating point constants to single precision constants

fsplit-ivs-in-unroller
Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
Split lifetimes of induction variables when loops are unrolled

fsplit-stack
Common Report Var(flag_split_stack) Init(-1)
Generate discontiguous stack frames

fsplit-wide-types
Common Report Var(flag_split_wide_types) Optimization
Split wide types into independent registers

fvariable-expansion-in-unroller
Common Report Var(flag_variable_expansion_in_unroller) Optimization
Apply variable expansion when loops are unrolled

fstack-check=
Common Report RejectNegative Joined
-fstack-check=[no|generic|specific]	Insert stack checking code into the program

fstack-check
Common Alias(fstack-check=, specific, no)
Insert stack checking code into the program.  Same as -fstack-check=specific

fstack-limit
Common Var(common_deferred_options) Defer

fstack-limit-register=
Common RejectNegative Joined Var(common_deferred_options) Defer
-fstack-limit-register=<register>	Trap if the stack goes past <register>

fstack-limit-symbol=
Common RejectNegative Joined Var(common_deferred_options) Defer
-fstack-limit-symbol=<name>	Trap if the stack goes past symbol <name>

fstack-protector
Common Report Var(flag_stack_protect, 1)
Use propolice as a stack protection method

fstack-protector-all
Common Report RejectNegative Var(flag_stack_protect, 2)
Use a stack protection method for every function

fstack-usage
Common RejectNegative Var(flag_stack_usage)
Output stack usage information on a per-function basis

fstrength-reduce
Common Ignore
Does nothing.  Preserved for backward compatibility.

; Nonzero if we should do (language-dependent) alias analysis.
; Typically, this analysis will assume that expressions of certain
; types do not alias expressions of certain other types.  Only used
; if alias analysis (in general) is enabled.
fstrict-aliasing
Common Report Var(flag_strict_aliasing) Optimization
Assume strict aliasing rules apply

fstrict-overflow
Common Report Var(flag_strict_overflow)
Treat signed overflow as undefined

fsyntax-only
Common Report Var(flag_syntax_only)
Check for syntax errors, then stop

ftest-coverage
Common Report Var(flag_test_coverage)
Create data files needed by \"gcov\"

fthread-jumps
Common Report Var(flag_thread_jumps) Optimization
Perform jump threading optimizations

ftime-report
Common Report Var(time_report)
Report the time taken by each compiler pass

ftls-model=
Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
-ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]	Set the default thread-local storage code generation model

Enum
Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)

EnumValue
Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)

EnumValue
Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)

EnumValue
Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)

EnumValue
Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)

ftoplevel-reorder
Common Report Var(flag_toplevel_reorder) Init(2) Optimization
Reorder top level functions, variables, and asms

ftracer
Common Report Var(flag_tracer)
Perform superblock formation via tail duplication

; Zero means that floating-point math operations cannot generate a
; (user-visible) trap.  This is the case, for example, in nonstop
; IEEE 754 arithmetic.
ftrapping-math
Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
Assume floating-point operations can trap

ftrapv
Common Report Var(flag_trapv) Optimization
Trap for signed overflow in addition, subtraction and multiplication

ftree-ccp
Common Report Var(flag_tree_ccp) Optimization
Enable SSA-CCP optimization on trees

ftree-bit-ccp
Common Report Var(flag_tree_bit_ccp) Optimization
Enable SSA-BIT-CCP optimization on trees

ftree-store-ccp
Common Ignore
Does nothing.  Preserved for backward compatibility.

ftree-ch
Common Report Var(flag_tree_ch) Optimization
Enable loop header copying on trees

ftree-copyrename
Common Report Var(flag_tree_copyrename) Optimization
Replace SSA temporaries with better names in copies

ftree-copy-prop
Common Report Var(flag_tree_copy_prop) Optimization
Enable copy propagation on trees

ftree-store-copy-prop
Common Ignore
Does nothing.  Preserved for backward compatibility.

ftree-cselim
Common Report Var(flag_tree_cselim) Init(2) Optimization
Transform condition stores into unconditional ones

ftree-switch-conversion
Common Report Var(flag_tree_switch_conversion) Optimization
Perform conversions of switch initializations.

ftree-dce
Common Report Var(flag_tree_dce) Optimization
Enable SSA dead code elimination optimization on trees

ftree-dominator-opts
Common Report Var(flag_tree_dom) Optimization
Enable dominator optimizations

ftree-dse
Common Report Var(flag_tree_dse) Optimization
Enable dead store elimination

ftree-forwprop
Common Report Var(flag_tree_forwprop) Init(1) Optimization
Enable forward propagation on trees

ftree-fre
Common Report Var(flag_tree_fre) Optimization
Enable Full Redundancy Elimination (FRE) on trees

ftree-loop-distribution
Common Report Var(flag_tree_loop_distribution) Optimization
Enable loop distribution on trees

ftree-loop-distribute-patterns
Common Report Var(flag_tree_loop_distribute_patterns) Optimization
Enable loop distribution for patterns transformed into a library call

ftree-loop-im
Common Report Var(flag_tree_loop_im) Init(1) Optimization
Enable loop invariant motion on trees

ftree-loop-linear
Common Alias(floop-interchange)
Enable loop interchange transforms.  Same as -floop-interchange

ftree-loop-ivcanon
Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
Create canonical induction variables in loops

ftree-loop-optimize
Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
Enable loop optimizations on tree level

ftree-parallelize-loops=
Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
Enable automatic parallelization of loops

ftree-phiprop
Common Report Var(flag_tree_phiprop) Init(1) Optimization
Enable hoisting loads from conditional pointers.

ftree-pre
Common Report Var(flag_tree_pre) Optimization
Enable SSA-PRE optimization on trees

ftree-pta
Common Report Var(flag_tree_pta) Init(1) Optimization
Perform function-local points-to analysis on trees.

ftree-reassoc
Common Report Var(flag_tree_reassoc) Init(1) Optimization
Enable reassociation on tree level

ftree-salias
Common Ignore
Does nothing.  Preserved for backward compatibility.

ftree-sink
Common Report Var(flag_tree_sink) Optimization
Enable SSA code sinking on trees

ftree-sra
Common Report Var(flag_tree_sra) Optimization
Perform scalar replacement of aggregates

ftree-ter
Common Report Var(flag_tree_ter) Optimization
Replace temporary expressions in the SSA->normal pass

ftree-lrs
Common Report Var(flag_tree_live_range_split) Optimization
Perform live range splitting during the SSA->normal pass

ftree-vrp
Common Report Var(flag_tree_vrp) Init(0) Optimization
Perform Value Range Propagation on trees

funit-at-a-time
Common Report Var(flag_unit_at_a_time) Init(1) Optimization
Compile whole compilation unit at a time

funroll-loops
Common Report Var(flag_unroll_loops) Optimization
Perform loop unrolling when iteration count is known

funroll-all-loops
Common Report Var(flag_unroll_all_loops) Optimization
Perform loop unrolling for all loops

; Nonzero means that loop optimizer may assume that the induction variables
; that control loops do not overflow and that the loops with nontrivial
; exit condition are not infinite
funsafe-loop-optimizations
Common Report Var(flag_unsafe_loop_optimizations) Optimization
Allow loop optimizations to assume that the loops behave in normal way

fassociative-math
Common Report Var(flag_associative_math) SetByCombined
Allow optimization for floating-point arithmetic which may change the
result of the operation due to rounding.

freciprocal-math
Common Report Var(flag_reciprocal_math) SetByCombined
Same as -fassociative-math for expressions which include division.

; Nonzero means that unsafe floating-point math optimizations are allowed
; for the sake of speed.  IEEE compliance is not guaranteed, and operations
; are allowed to assume that their arguments and results are "normal"
; (e.g., nonnegative for SQRT).
funsafe-math-optimizations
Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
Allow math optimizations that may violate IEEE or ISO standards

funswitch-loops
Common Report Var(flag_unswitch_loops) Optimization
Perform loop unswitching

funwind-tables
Common Report Var(flag_unwind_tables) Optimization
Just generate unwind tables for exception handling

fuse-linker-plugin
Common Undocumented

; Positive if we should track variables, negative if we should run
; the var-tracking pass only to discard debug annotations, zero if
; we're not to run it.  When flag_var_tracking == 2 (AUTODETECT_VALUE) it
; will be set according to optimize, debug_info_level and debug_hooks
; in process_options ().
fvar-tracking
Common Report Var(flag_var_tracking) Init(2) Optimization
Perform variable tracking

; Positive if we should track variables at assignments, negative if
; we should run the var-tracking pass only to discard debug
; annotations.  When flag_var_tracking_assignments ==
; AUTODETECT_VALUE it will be set according to flag_var_tracking.
fvar-tracking-assignments
Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
Perform variable tracking by annotating assignments

; Nonzero if we should toggle flag_var_tracking_assignments after
; processing options and computing its default.  */
fvar-tracking-assignments-toggle
Common Report Var(flag_var_tracking_assignments_toggle) Optimization
Toggle -fvar-tracking-assignments

fvar-tracking-uninit
Common Report Var(flag_var_tracking_uninit) Optimization
Perform variable tracking and also tag variables that are uninitialized

ftree-vectorize
Common Report Var(flag_tree_vectorize) Optimization
Enable loop vectorization on trees

ftree-slp-vectorize
Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
Enable basic block vectorization (SLP) on trees

fvect-cost-model
Common Report Var(flag_vect_cost_model) Optimization
Enable use of cost model in vectorization

ftree-vect-loop-version
Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
Enable loop versioning when doing loop vectorization on trees

ftree-vectorizer-verbose=
Common RejectNegative Joined UInteger
-ftree-vectorizer-verbose=<number>	Set the verbosity level of the vectorizer

ftree-scev-cprop
Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
Enable copy propagation of scalar-evolution information.

; -fverbose-asm causes extra commentary information to be produced in
; the generated assembly code (to make it more readable).  This option
; is generally only of use to those who actually need to read the
; generated assembly code (perhaps while debugging the compiler itself).
; -fno-verbose-asm, the default, causes the extra information
; to not be added and is useful when comparing two assembler files.
fverbose-asm
Common Report Var(flag_verbose_asm)
Add extra commentary to assembler output

fvisibility=
Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
-fvisibility=[default|internal|hidden|protected]	Set the default symbol visibility

Enum
Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)

EnumValue
Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)

EnumValue
Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)

EnumValue
Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)

EnumValue
Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)

fvpt
Common Report Var(flag_value_profile_transformations) Optimization
Use expression value profiles in optimizations

fweb
Common Report Var(flag_web) Init(2) Optimization
Construct webs and split unrelated uses of single variable

ftree-builtin-call-dce
Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
Enable conditional dead code elimination for builtin calls

fwhole-program
Common Report Var(flag_whole_program) Init(0) Optimization
Perform whole program optimizations

fwrapv
Common Report Var(flag_wrapv) Optimization
Assume signed arithmetic overflow wraps around

fzero-initialized-in-bss
Common Report Var(flag_zero_initialized_in_bss) Init(1)
Put zero initialized data in the bss section

g
Common JoinedOrMissing
Generate debug information in default format

gcoff
Common JoinedOrMissing Negative(gdwarf-)
Generate debug information in COFF format

gdwarf-
Common Joined UInteger Var(dwarf_version) Init(2) Negative(gstabs)
Generate debug information in DWARF v2 (or later) format

ggdb
Common JoinedOrMissing
Generate debug information in default extended format

gstabs
Common JoinedOrMissing Negative(gstabs+)
Generate debug information in STABS format

gstabs+
Common JoinedOrMissing Negative(gvms)
Generate debug information in extended STABS format

gno-strict-dwarf
Common RejectNegative Var(dwarf_strict,0) Init(-1)
Emit DWARF additions beyond selected version

gstrict-dwarf
Common Report RejectNegative Var(dwarf_strict,1)
Don't emit DWARF additions beyond selected version

gtoggle
Common Report Var(flag_gtoggle)
Toggle debug information generation

gvms
Common JoinedOrMissing Negative(gxcoff)
Generate debug information in VMS format

gxcoff
Common JoinedOrMissing Negative(gxcoff+)
Generate debug information in XCOFF format

gxcoff+
Common JoinedOrMissing Negative(gcoff)
Generate debug information in extended XCOFF format

h
Driver Joined Separate

iplugindir=
Common Joined Var(plugindir_string) Init(0)
-iplugindir=<dir>	Set <dir> to be the default plugin directory

l
Driver Joined Separate

n
Driver

no-canonical-prefixes
Driver

nodefaultlibs
Driver

nostartfiles
Driver

nostdlib
Driver

o
Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
-o <file>	Place output into <file>

p
Common Var(profile_flag)
Enable function profiling

pass-exit-codes
Driver Var(pass_exit_codes)

pedantic
Common Var(pedantic)
Issue warnings needed for strict compliance to the standard

pedantic-errors
Common Var(flag_pedantic_errors)
Like -pedantic but issue them as errors

pg
Driver

pipe
Driver Var(use_pipes)

print-file-name=
Driver JoinedOrMissing Var(print_file_name)

print-libgcc-file-name
Driver

print-multi-directory
Driver Var(print_multi_directory)

print-multi-lib
Driver Var(print_multi_lib)

print-multi-os-directory
Driver Var(print_multi_os_directory)

print-prog-name=
Driver JoinedOrMissing Var(print_prog_name)

print-search-dirs
Driver Var(print_search_dirs)

print-sysroot
Driver Var(print_sysroot)

print-sysroot-headers-suffix
Driver Var(print_sysroot_headers_suffix)

quiet
Common Var(quiet_flag) RejectDriver
Do not display functions compiled or elapsed time

r
Driver

s
Driver

save-temps
Driver

save-temps=
Driver Joined

t
Driver

time
Driver Var(report_times)

time=
Driver JoinedOrMissing

u
Driver Joined Separate

undef
Driver
; C option, but driver must not handle as "-u ndef".

v
Common Driver Var(verbose_flag)
Enable verbose output

version
Common Var(version_flag) RejectDriver
Display the compiler's version

w
Common Var(inhibit_warnings)
Suppress warnings

wrapper
Driver Separate Var(wrapper_string)

x
Driver Joined Separate

shared
Common RejectNegative Negative(pie)
Create a shared library

shared-libgcc
Driver

specs
Driver Separate Alias(specs=)

specs=
Driver Joined

static
Driver

static-libgcc
Driver

static-libgfortran
Driver
; Documented for Fortran, but always accepted by driver.

static-libstdc++
Driver

static-libgo
Driver
; Documented for Go, but always accepted by driver.

symbolic
Driver

pie
Common RejectNegative Negative(shared)
Create a position independent executable

z
Driver Joined Separate

; This comment is to ensure we retain the blank line above.