; Options for the language- and target-independent parts of the compiler.
-; Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+
+; Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
;
; This file is part of GCC.
;
; the terms of the GNU General Public License as published by the Free
; Software Foundation; either version 2, 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 COPYING. If not, write to the Free
-; Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-; 02111-1307, USA.
+; Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+; 02110-1301, USA.
-; See c.opt for a description of this file's format.
+; See the GCC internals manual for a description of this file's format.
; Please try to keep this file in ASCII collating order.
Common
Display this information
--param
-Common Separate
---param <param>=<value> Set paramter <param> to value. See below for a complete list of parameters
+-help=
+Common Report Joined
+--help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
-target-help
Common
+Alias for --help=target
+
+;; The following three entries are to work around the gcc driver
+;; program's insatiable desire to turn options starting with a
+;; double dash (--) into options starting with a dash f (-f).
+fhelp
+Common
+
+fhelp=
+Common Joined
+
+ftarget-help
+Common
+
+-param
+Common Separate
+--param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
-version
Common
This switch is deprecated; use -Wextra instead
Waggregate-return
-Common
+Common Var(warn_aggregate_return) Warning
Warn about returning structures, unions or arrays
+Walways-true
+Common Var(warn_always_true) Warning
+Warn about comparisons that always evaluate to true
+
+Warray-bounds
+Common Var(warn_array_bounds)
+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
+Common Var(warn_cast_align) Warning
Warn about pointer casts which increase alignment
Wdeprecated-declarations
-Common
+Common Var(warn_deprecated_decl) Init(1) Warning
Warn about uses of __attribute__((deprecated)) declarations
Wdisabled-optimization
-Common
+Common Var(warn_disabled_optimization) Warning
Warn when an optimization pass is disabled
Werror
-Common
+Common Var(warnings_are_errors)
Treat all warnings as errors
+Werror=
+Common Joined
+Treat specified warning as error
+
Wextra
-Common
+Common Warning
Print extra (possibly unwanted) warnings
Wfatal-errors
-Common
+Common Var(flag_fatal_errors)
Exit on the first error occurred
Winline
-Common
+Common Var(warn_inline) Warning
Warn when an inlined function cannot be inlined
Wlarger-than-
-Common RejectNegative Joined UInteger
+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
+Common Var(warn_missing_noreturn) Warning
Warn about functions which might be candidates for __attribute__((noreturn))
+Woverflow
+Common Var(warn_overflow) Init(1) Warning
+Warn about overflow in arithmetic expressions
+
Wpacked
-Common
+Common Var(warn_packed) Warning
Warn when the packed attribute has no effect on struct layout
Wpadded
-Common
+Common Var(warn_padded) Warning
Warn when padding is required to align structure members
Wshadow
-Common
+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
+
Wstrict-aliasing
-Common
+Common Warning
Warn about code which might break strict aliasing rules
Wstrict-aliasing=
-Common Joined UInteger
+Common Joined UInteger Warning
Warn about code which might break strict aliasing rules
-Wswitch
+Wstrict-overflow
Common
+Warn about optimizations that assume that signed overflow is undefined
+
+Wstrict-overflow=
+Common Joined UInteger
+Warn about optimizations that assume that signed overflow is undefined
+
+Wstring-literal-comparison
+Common Var(warn_string_literal_comparison) Warning
+Warn about comparisons to constant string literals
+
+Wswitch
+Common Var(warn_switch) Warning
Warn about enumerated switches, with no default, missing a case
Wswitch-default
-Common
+Common Var(warn_switch_default) Warning
Warn about enumerated switches missing a \"default:\" statement
Wswitch-enum
-Common
+Common Var(warn_switch_enum) Warning
Warn about all enumerated switches missing a specific case
Wsystem-headers
-Common
+Common Var(warn_system_headers) Warning
Do not suppress warnings from system headers
Wuninitialized
-Common
+Common Var(warn_uninitialized) Warning
Warn about uninitialized automatic variables
Wunreachable-code
-Common
+Common Var(warn_notreached) Warning
Warn about code that will never be executed
Wunused
-Common
+Common Warning
Enable all -Wunused- warnings
Wunused-function
-Common
+Common Var(warn_unused_function) Warning
Warn when a function is unused
Wunused-label
-Common
+Common Var(warn_unused_label) Warning
Warn when a label is unused
Wunused-parameter
-Common
+Common Var(warn_unused_parameter) Warning
Warn when a function parameter is unused
Wunused-value
-Common
+Common Var(warn_unused_value) Warning
Warn when an expression value is unused
Wunused-variable
-Common
+Common Var(warn_unused_variable) Warning
Warn when a variable is unused
+Wvolatile-register-var
+Common Var(warn_register_var) Warning
+Warn when a register variable is declared volatile
+
+Wcoverage-mismatch
+Common RejectNegative Var(warn_coverage_mismatch)
+Warn instead of error in case profiles in -fprofile-use do not match
+
aux-info
Common Separate
-aux-info <file> Emit declaration information into <file>
Common Separate
-dumpbase <file> Set the file basename to be used for dumps
-fPIC
-Common
-
-fPIE
-Common
-
+; 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.
+;
+; Additional positive integers will be assigned as new versions of
+; the ABI become the default version of the ABI.
fabi-version=
-Common Joined UInteger
+Common Joined UInteger Var(flag_abi_version) Init(2)
falign-functions
-Common
+Common Report Var(align_functions,0)
Align the start of functions
falign-functions=
Common RejectNegative Joined UInteger
falign-jumps
-Common
+Common Report Var(align_jumps,0) Optimization
Align labels which are only reached by jumping
falign-jumps=
Common RejectNegative Joined UInteger
falign-labels
-Common
+Common Report Var(align_labels,0) Optimization
Align all labels
falign-labels=
Common RejectNegative Joined UInteger
falign-loops
-Common
+Common Report Var(align_loops) Optimization
Align the start of loops
falign-loops=
Common RejectNegative Joined UInteger
+; This flag is only tested if alias checking is enabled.
+; 0 if pointer arguments may alias each other. True in C.
+; 1 if pointer arguments may not alias each other but may alias
+; global variables.
+; 2 if pointer arguments may not alias each other and may not
+; alias global variables.
+; 3 if pointer arguments may not alias anything. True in Fortran.
+; Set by the front end.
fargument-alias
-Common
+Common Report Var(flag_argument_noalias,0) Optimization
Specify that arguments may alias each other and globals
fargument-noalias
-Common
+Common Report Var(flag_argument_noalias,1) VarExists Optimization
Assume arguments may alias globals but not each other
fargument-noalias-global
-Common
+Common Report Var(flag_argument_noalias,2) VarExists Optimization
Assume arguments alias neither each other nor globals
+fargument-noalias-anything
+Common Report Var(flag_argument_noalias,3) VarExists Optimization
+Assume arguments alias no other storage
+
fasynchronous-unwind-tables
-Common
+Common Report Var(flag_asynchronous_unwind_tables) Optimization
Generate unwind tables that are exact at each instruction boundary
+; -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
+Common Report Var(flag_bounds_check)
Generate code to check bounds before indexing arrays
fbranch-count-reg
-Common
+Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
Replace add, compare, branch with branch on count register
fbranch-probabilities
-Common
+Common Report Var(flag_branch_probabilities) Optimization
Use profiling information for branch probabilities
fbranch-target-load-optimize
-Common
+Common Report Var(flag_branch_target_load_optimize) Optimization
Perform branch target load optimization before prologue / epilogue threading
fbranch-target-load-optimize2
-Common
+Common Report Var(flag_branch_target_load_optimize2) Optimization
Perform branch target load optimization after prologue / epilogue threading
fbtr-bb-exclusive
-Common
+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
-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
+Common Report Var(flag_caller_saves) Optimization
Save registers around function calls
fcommon
-Common
+Common Report Var(flag_no_common,0) Optimization
Do not put uninitialized globals in the common section
fcprop-registers
-Common
+Common Report Var(flag_cprop_registers) Optimization
Perform a register copy-propagation optimization pass
fcrossjumping
-Common
+Common Report Var(flag_crossjumping) Optimization
Perform cross-jumping optimization
fcse-follow-jumps
-Common
+Common Report Var(flag_cse_follow_jumps) Optimization
When running CSE, follow jumps to their targets
fcse-skip-blocks
-Common
+Common Report Var(flag_cse_skip_blocks) Optimization
When running CSE, follow conditional jumps
+fcx-limited-range
+Common Report Var(flag_cx_limited_range) Optimization
+Omit range reduction step when performing complex division
+
fdata-sections
-Common
+Common Report Var(flag_data_sections) Optimization
Place data items into their own section
+; 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
+Common Report Var(flag_defer_pop) Optimization
Defer popping functions args from stack until later
fdelayed-branch
-Common
+Common Report Var(flag_delayed_branch) Optimization
Attempt to fill delay slots of branch instructions
fdelete-null-pointer-checks
-Common
+Common Report Var(flag_delete_null_pointer_checks) Optimization
Delete useless null pointer checks
fdiagnostics-show-location=
Common Joined RejectNegative
-fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
+fdiagnostics-show-option
+Common
+Amend appropriate diagnostic messages with the command line option that controls them
+
fdump-
Common Joined RejectNegative
-fdump-<type> Dump various compiler internals to a file
+fdump-noaddr
+Common Report Var(flag_dump_noaddr)
+Suppress output of addresses in debugging dumps
+
fdump-unnumbered
-Common
-Suppress output of instruction numbers and line number notes in debugging dumps
+Common Report Var(flag_dump_unnumbered) VarExists
+Suppress output of instruction numbers, line number notes and addresses in debugging dumps
+
+fearly-inlining
+Common Report Var(flag_early_inlining) Init(1) Optimization
+Perform early inlining
feliminate-dwarf2-dups
-Common
+Common Report Var(flag_eliminate_dwarf2_dups)
Perform DWARF2 duplicate elimination
feliminate-unused-debug-symbols
-Common
+Common Report Var(flag_debug_only_used_symbols)
Perform unused type elimination in debug info
feliminate-unused-debug-types
-Common
+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(1)
+Do not suppress C++ class debug information.
+
fexceptions
-Common
+Common Report Var(flag_exceptions) Optimization
Enable exception handling
fexpensive-optimizations
-Common
+Common Report Var(flag_expensive_optimizations) Optimization
Perform a number of minor, expensive optimizations
ffast-math
Common
ffinite-math-only
-Common
+Common Report Var(flag_finite_math_only) Optimization
Assume no NaNs or infinities are generated
ffixed-
-ffixed-<register> Mark <register> as being unavailable to the compiler
ffloat-store
-Common
-Do not store floats in registers
+Common Report Var(flag_float_store) Optimization
+Don't allocate floats and doubles in extended-precision registers
+; Nonzero for -fforce-addr: load memory address into a register before
+; reference to memory. This makes better cse but slower compilation.
fforce-addr
-Common
+Common Report Var(flag_force_addr) Optimization
Copy memory address constants into registers before use
-fforce-mem
-Common
-Copy memory operands into registers before use
+fforward-propagate Optimization
+Common Report Var(flag_forward_propagate)
+Perform a forward propagation pass on RTL
+; 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
+Common Report Var(flag_no_function_cse,0)
Allow function addresses to be held in registers
ffunction-sections
-Common
+Common Report Var(flag_function_sections)
Place each function into its own section
fgcse
-Common
+Common Report Var(flag_gcse) Optimization
Perform global common subexpression elimination
fgcse-lm
-Common
+Common Report Var(flag_gcse_lm) Init(1) Optimization
Perform enhanced load motion during global common subexpression elimination
fgcse-sm
-Common
+Common Report Var(flag_gcse_sm) Init(0) Optimization
Perform store motion after global common subexpression elimination
fgcse-las
-Common
+Common Report Var(flag_gcse_las) Init(0) Optimization
Perform redundant load after store elimination in global common subexpression
elimination
fgcse-after-reload
-Common
+Common Report Var(flag_gcse_after_reload) Optimization
Perform global common subexpression elimination after register allocation
-has finished.
+has finished
fguess-branch-probability
-Common
+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
+Common Report Var(flag_no_ident,0)
Process #ident directives
fif-conversion
-Common
+Common Report Var(flag_if_conversion) Optimization
Perform conversion of conditional jumps to branchless equivalents
fif-conversion2
-Common
+Common Report Var(flag_if_conversion2) Optimization
Perform conversion of conditional jumps to conditional execution
+; -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
+Common Report Var(flag_inhibit_size_directive)
Do not generate .size directives
+; 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
+Common Report Var(flag_no_inline,0) Init(2)
Pay attention to the \"inline\" keyword
finline-functions
-Common
+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) Init(1) Optimization
+Integrate functions called once into their callers
+
finline-limit-
Common RejectNegative Joined UInteger
-finline-limit=<number> Limit the size of inlined functions to <number>
finstrument-functions
-Common
+Common Report Var(flag_instrument_function_entry_exit)
Instrument function entry and exit with profiling calls
+fipa-cp
+Common Report Var(flag_ipa_cp) Optimization
+Perform Interprocedural constant propagation
+
+fipa-pure-const
+Common Report Var(flag_ipa_pure_const) Init(0) Optimization
+Discover pure and const functions
+
+fipa-pta
+Common Report Var(flag_ipa_pta) Init(0) Optimization
+Perform interprocedural points-to analysis
+
+fipa-reference
+Common Report Var(flag_ipa_reference) Init(0) Optimization
+Discover readonly and non addressable static variables
+
+fipa-type-escape
+Common Report Var(flag_ipa_type_escape) Init(0) Optimization
+Type based escape and alias analysis
+
+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
+Common Report Var(flag_keep_inline_functions)
Generate code for functions even if they are fully inlined
fkeep-static-consts
-Common
+Common Report Var(flag_keep_static_consts) Init(1)
Emit static const variables even if they are not used
fleading-underscore
-Common
+Common Report Var(flag_leading_underscore) Init(-1)
Give external symbols a leading underscore
floop-optimize
Common
-Perform loop optimizations
+Does nothing. Preserved for backward compatibility.
fmath-errno
-Common
+Common Report Var(flag_errno_math) Init(1)
Set errno after built-in math functions
fmem-report
-Common
+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
+Common Report Var(flag_merge_constants,2) Init(1) Optimization
Attempt to merge identical constants and constant variables
fmerge-constants
-Common
+Common Report Var(flag_merge_constants,1) VarExists Optimization
Attempt to merge identical constants across compilation units
fmessage-length=
Common RejectNegative Joined UInteger
-fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
-fmove-all-movables
-Common
-Force all loop invariant computations out of loops
+fmodulo-sched
+Common Report Var(flag_modulo_sched) Optimization
+Perform SMS based modulo scheduling before the first scheduling pass
+
+fmove-loop-invariants
+Common Report Var(flag_move_loop_invariants) Init(1) Optimization
+Move loop invariant computations out of loops
fmudflap
-Common RejectNegative
-Add mudflap bounds-checking instrumentation for single-threaded program.
+Common RejectNegative Report Var(flag_mudflap)
+Add mudflap bounds-checking instrumentation for single-threaded program
fmudflapth
-Common RejectNegative
-Add mudflap bounds-checking instrumentation for multi-threaded program.
+Common RejectNegative Report VarExists Var(flag_mudflap,2)
+Add mudflap bounds-checking instrumentation for multi-threaded program
fmudflapir
-Common RejectNegative
-Ignore read operations when inserting mudflap instrumentation.
+Common RejectNegative Report Var(flag_mudflap_ignore_reads)
+Ignore read operations when inserting mudflap instrumentation
-fnew-ra
-Common
-Use graph-coloring register allocation
+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
+Common Report Var(flag_non_call_exceptions) Optimization
Support synchronous non-call exceptions
-fold-unroll-loops
-Common
-Perform loop unrolling when iteration count is known
-
-fold-unroll-all-loops
-Common
-Perform loop unrolling for all loops
-
fomit-frame-pointer
-Common
+Common Report Var(flag_omit_frame_pointer) Optimization
When possible do not generate stack frames
foptimize-register-move
-Common
+Common Report Var(flag_regmove) Optimization
Do the full register move optimization pass
foptimize-sibling-calls
-Common
+Common Report Var(flag_optimize_sibling_calls) Optimization
Optimize sibling and tail recursive calls
+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
+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
+Common Report Var(flag_pcc_struct_return,1) VarExists
Return small aggregates in memory, not registers
fpeel-loops
-Common
+Common Report Var(flag_peel_loops) Optimization
Perform loop peeling
fpeephole
-Common
+Common Report Var(flag_no_peephole,0) Optimization
Enable machine specific peephole optimizations
fpeephole2
-Common
+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
-Generate position-independent code if possible
+Common Report Var(flag_pic,1) VarExists
+Generate position-independent code if possible (small mode)
fpie
-Common
-Generate position-independent code for executables if possible
+Common Report Var(flag_pie,1) VarExists
+Generate position-independent code for executables if possible (small mode)
fprefetch-loop-arrays
-Common
+Common Report Var(flag_prefetch_loop_arrays) Optimization
Generate prefetch instructions, if available, for arrays in loops
fprofile
-Common
+Common Report Var(profile_flag)
Enable basic program profiling code
fprofile-arcs
-Common
+Common Report Var(profile_arc_flag)
Insert arc-based program profiling code
fprofile-generate
Enable common options for performing profile feedback directed optimizations
fprofile-values
-Common
+Common Report Var(flag_profile_values)
Insert code to profile values of expressions
frandom-seed
Common Joined RejectNegative
-frandom-seed=<string> Make compile reproducible using <string>
-freduce-all-givs
-Common
-Strength reduce all loop general induction variables
+; 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
+Common Report Var(flag_pcc_struct_return,0) VarExists Optimization
Return small aggregates in registers
fregmove
-Common
+Common Report Var(flag_regmove) Optimization
Enables a register move optimization
frename-registers
-Common
+Common Report Var(flag_rename_registers) Init(2) Optimization
Perform a register renaming optimization pass
freorder-blocks
-Common
+Common Report Var(flag_reorder_blocks) Optimization
Reorder basic blocks to improve code placement
freorder-blocks-and-partition
-Common
+Common Report Var(flag_reorder_blocks_and_partition) Optimization
Reorder basic blocks and partition into hot and cold sections
freorder-functions
-Common
+Common Report Var(flag_reorder_functions) Optimization
Reorder functions to improve code placement
frerun-cse-after-loop
-Common
+Common Report Var(flag_rerun_cse_after_loop) Init(2) Optimization
Add a common subexpression elimination pass after loop optimizations
frerun-loop-opt
Common
-Run the loop optimizer twice
+Does nothing. Preserved for backward compatibility.
frounding-math
-Common
+Common Report Var(flag_rounding_math) Optimization
Disable optimizations that assume default FP rounding behavior
fsched-interblock
-Common
+Common Report Var(flag_schedule_interblock) Init(1) Optimization
Enable scheduling across basic blocks
fsched-spec
-Common
+Common Report Var(flag_schedule_speculative) Init(1) Optimization
Allow speculative motion of non-loads
fsched-spec-load
-Common
+Common Report Var(flag_schedule_speculative_load) Optimization
Allow speculative motion of some loads
fsched-spec-load-dangerous
-Common
+Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
Allow speculative motion of more loads
fsched-verbose=
-fsched-verbose=<number> Set the verbosity level of the scheduler
fsched2-use-superblocks
-Common
+Common Report Var(flag_sched2_use_superblocks) Optimization
If scheduling post reload, do superblock scheduling
fsched2-use-traces
-Common
+Common Report Var(flag_sched2_use_traces) Optimization
If scheduling post reload, do trace scheduling
fschedule-insns
-Common
+Common Report Var(flag_schedule_insns) Optimization
Reschedule instructions before register allocation
fschedule-insns2
-Common
+Common Report Var(flag_schedule_insns_after_reload) Optimization
Reschedule instructions after register allocation
+; sched_stalled_insns means that insns can be moved prematurely from the queue
+; of stalled insns into the ready list.
fsched-stalled-insns
-Common
+Common Report Var(flag_sched_stalled_insns) Optimization
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
+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
+Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization
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-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
-fshared-data
-Common
-Mark data as shared rather than private
+fsection-anchors
+Common Report Var(flag_section_anchors) Optimization
+Access data in the same section from shared anchor points
+
+frtl-abstract-sequences
+Common Report Var(flag_rtl_seqabstr) Optimization
+Perform sequence abstraction optimization on RTL
+
+fsee
+Common Report Var(flag_see) Init(0)
+Eliminate redundant sign extensions using LCM.
+
+fshow-column
+Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(1)
+Show column numbers in diagnostics, when available. Default on
fsignaling-nans
-Common
+Common Report Var(flag_signaling_nans) Optimization
Disable optimizations observable by IEEE signaling NaNs
+fsigned-zeros
+Common Report Var(flag_signed_zeros) Init(1)
+Disable floating point optimizations that ignore the IEEE signedness of zero
+
fsingle-precision-constant
-Common
+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-wide-types
+Common Report Var(flag_split_wide_types)
+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
+
+; Emit code to probe the stack, to help detect stack overflow; also
+; may cause large objects to be allocated dynamically.
fstack-check
-Common
+Common Report Var(flag_stack_check)
Insert stack checking code into the program
fstack-limit
Common RejectNegative Joined
-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) VarExists
+Use a stack protection method for every function
+
fstrength-reduce
Common
-Perform strength reduction optimizations
+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
+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
+Common Report Var(flag_syntax_only)
Check for syntax errors, then stop
ftest-coverage
-Common
+Common Report Var(flag_test_coverage)
Create data files needed by \"gcov\"
fthread-jumps
-Common
+Common Report Var(flag_thread_jumps) Optimization
Perform jump threading optimizations
ftime-report
-Common
+Common Report Var(time_report)
Report the time taken by each compiler pass
ftls-model=
Common Joined RejectNegative
-ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
+ftoplevel-reorder
+Common Report Var(flag_toplevel_reorder) Init(1) Optimization
+Reorder top level functions, variables, and asms
+
ftracer
-Common
+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
+Common Report Var(flag_trapping_math) Init(1) Optimization
Assume floating-point operations can trap
ftrapv
-Common
+Common Report Var(flag_trapv) Optimization
Trap for signed overflow in addition, subtraction and multiplication
-ftree-based-profiling
-Common
-Use tree-ssa based implementation of profiling
-
ftree-ccp
-Common
+Common Report Var(flag_tree_ccp) Optimization
Enable SSA-CCP optimization on trees
+ftree-store-ccp
+Common Report Var(flag_tree_store_ccp) Optimization
+Enable SSA-CCP optimization for stores and loads
+
ftree-ch
-Common
+Common Report Var(flag_tree_ch) Optimization
Enable loop header copying on trees
-ftree-combine-temps
-Common
-Coalesce memory temporaries in the SSA->normal pass
-
ftree-copyrename
-Common
-Replace SSA temporaries with better names in copies.
+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 Report Var(flag_tree_store_copy_prop) Optimization
+Enable copy propagation for stores and loads
ftree-dce
-Common
+Common Report Var(flag_tree_dce) Optimization
Enable SSA dead code elimination optimization on trees
ftree-dominator-opts
-Common
+Common Report Var(flag_tree_dom) Optimization
Enable dominator optimizations
ftree-dse
-Common
+Common Report Var(flag_tree_dse) Optimization
Enable dead store elimination
-ftree-loop-optimize
-Common
-Enable loop optimizations on trees
+ftree-fre
+Common Report Var(flag_tree_fre) Optimization
+Enable Full Redundancy Elimination (FRE) on trees
-ftree-points-to=
-Common Joined RejectNegative
+ftree-loop-im
+Common Report Var(flag_tree_loop_im) Init(1) Optimization
+Enable loop invariant motion on trees
+
+ftree-loop-linear
+Common Report Var(flag_tree_loop_linear) Optimization
+Enable linear loop transforms on trees
+
+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-pre
-Common
+Common Report Var(flag_tree_pre) Optimization
Enable SSA-PRE optimization on trees
+ftree-salias
+Common Report Var(flag_tree_salias) Optimization
+Perform structural alias analysis
+
+ftree-sink
+Common Report Var(flag_tree_sink) Optimization
+Enable SSA code sinking on trees
+
ftree-sra
-Common
+Common Report Var(flag_tree_sra) Optimization
Perform scalar replacement of aggregates
ftree-ter
-Common
+Common Report Var(flag_tree_ter) Optimization
Replace temporary expressions in the SSA->normal pass
ftree-lrs
-Common
-Perform live range splitting during the SSA->normal pass.
+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
+Common Report Var(flag_unit_at_a_time) Optimization
Compile whole compilation unit at a time
funroll-loops
-Common
+Common Report Var(flag_unroll_loops) Optimization
Perform loop unrolling when iteration count is known
funroll-all-loops
-Common
+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
+
+; 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
+Common Report Var(flag_unsafe_math_optimizations) Optimization
Allow math optimizations that may violate IEEE or ISO standards
funswitch-loops
-Common
+Common Report Var(flag_unswitch_loops) Optimization
Perform loop unswitching
funwind-tables
-Common
+Common Report Var(flag_unwind_tables) Optimization
Just generate unwind tables for exception handling
fvar-tracking
-Common
+Common Report Var(flag_var_tracking) VarExists Optimization
Perform variable tracking
+ftree-vectorize
+Common Report Var(flag_tree_vectorize) Optimization
+Enable loop vectorization on trees
+
+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
+-ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
+
+ftree-scev-cprop
+Common Report Var(flag_tree_scev_cprop) Init(1)
+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
+Common Report Var(flag_verbose_asm)
Add extra commentary to assembler output
+fvisibility=
+Common Joined RejectNegative
+-fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
+
+
fvpt
-Common
+Common Report Var(flag_value_profile_transformations) Optimization
Use expression value profiles in optimizations
fweb
-Common
+Common Report Var(flag_web) Init(2) Optimization
Construct webs and split unrelated uses of single variable
+fwhole-program
+Common Report Var(flag_whole_program) Init(0) Optimization
+Perform whole program optimizations
+
fwrapv
-Common
+Common Report Var(flag_wrapv) Optimization
Assume signed arithmetic overflow wraps around
fzero-initialized-in-bss
-Common
+Common Report Var(flag_zero_initialized_in_bss) Init(1)
Put zero initialized data in the bss section
g
Generate debug information in default format
gcoff
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gdwarf-2)
Generate debug information in COFF format
gdwarf-2
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gstabs)
Generate debug information in DWARF v2 format
ggdb
Generate debug information in default extended format
gstabs
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gstabs+)
Generate debug information in STABS format
gstabs+
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gvms)
Generate debug information in extended STABS format
gvms
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gxcoff)
Generate debug information in VMS format
gxcoff
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gxcoff+)
Generate debug information in XCOFF format
gxcoff+
-Common JoinedOrMissing
+Common JoinedOrMissing Negative(gcoff)
Generate debug information in extended XCOFF format
-m
-Common Joined
-
o
Common Joined Separate
-o <file> Place output into <file>
p
-Common
+Common Var(profile_flag)
Enable function profiling
pedantic
-Common
+Common Var(pedantic)
Issue warnings needed for strict compliance to the standard
pedantic-errors
Like -pedantic but issue them as errors
quiet
-Common
+Common Var(quiet_flag)
Do not display functions compiled or elapsed time
version
-Common
+Common Var(version_flag)
Display the compiler's version
w
-Common
+Common Var(inhibit_warnings)
Suppress warnings
; This comment is to ensure we retain the blank line above.