+ffinite-math-only
+Common Report Var(flag_finite_math_only)
+Assume no NaNs or infinities are generated
+
+ffixed-
+Common Joined RejectNegative
+-ffixed-<register> Mark <register> as being unavailable to the compiler
+
+ffloat-store
+Common Report Var(flag_float_store)
+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 Report Var(flag_force_addr)
+Copy memory address constants into registers before use
+
+; Nonzero for -fforce-mem: load memory value into a register
+; before arithmetic on it. This makes better cse but slower compilation.
+fforce-mem
+Common Report Var(flag_force_mem)
+Copy memory operands into registers before use
+
+; 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)
+Perform global common subexpression elimination
+
+fgcse-lm
+Common Report Var(flag_gcse_lm) Init(1)
+Perform enhanced load motion during global common subexpression elimination
+
+fgcse-sm
+Common Report Var(flag_gcse_sm) Init(1)
+Perform store motion after global common subexpression elimination
+
+fgcse-las
+Common Report Var(flag_gcse_las) Init(1)
+Perform redundant load after store elimination in global common subexpression
+elimination
+
+fgcse-after-reload
+Common Report Var(flag_gcse_after_reload)
+Perform global common subexpression elimination after register allocation
+has finished.
+
+fguess-branch-probability
+Common Report Var(flag_guess_branch_prob)
+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)
+Perform conversion of conditional jumps to branchless equivalents
+
+fif-conversion2
+Common Report Var(flag_if_conversion2)
+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 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 Report Var(flag_no_inline,0) Init(2)
+Pay attention to the \"inline\" keyword
+
+finline-functions
+Common Report Var(flag_inline_functions)
+Integrate simple functions into their callers
+
+finline-limit-
+Common RejectNegative Joined UInteger
+
+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
+
+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 Report Var(flag_loop_optimize)
+Perform loop optimizations
+
+floop-optimize2
+Common Report Var(flag_loop_optimize2)
+Perform loop optimizations using the new loop optimizer
+
+fmath-errno
+Common Report Var(flag_errno_math) Init(1)
+Set errno after built-in math functions
+
+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)
+Attempt to merge identical constants and constant variables
+
+fmerge-constants
+Common Report Var(flag_merge_constants,1) VarExists
+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
+
+fmodulo-sched
+Common Report Var(flag_modulo_sched)
+Perform SMS based modulo scheduling before the first scheduling pass
+
+fmove-all-movables
+Common Report Var(flag_move_all_movables)
+Force all loop invariant computations out of loops
+
+fmove-loop-invariants
+Common Report Var(flag_move_loop_invariants)
+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_threads)
+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.
+
+fnew-ra
+Common Report Var(flag_new_regalloc)
+Use graph-coloring register allocation
+
+freschedule-modulo-scheduled-loops
+Common Report Var(flag_resched_modulo_sched)
+Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
+
+fnon-call-exceptions
+Common Report Var(flag_non_call_exceptions)
+Support synchronous non-call exceptions
+
+fold-unroll-loops
+Common Report Var(flag_old_unroll_loops)
+Perform loop unrolling when iteration count is known
+
+fold-unroll-all-loops
+Common Report Var(flag_old_unroll_all_loops)
+Perform loop unrolling for all loops
+
+fomit-frame-pointer
+Common Report Var(flag_omit_frame_pointer)
+When possible do not generate stack frames
+
+foptimize-register-move
+Common Report Var(flag_regmove)
+Do the full register move optimization pass
+
+foptimize-sibling-calls
+Common Report Var(flag_optimize_sibling_calls)
+Optimize sibling and tail recursive calls
+
+fpack-struct
+Common Report Var(flag_pack_struct)
+Pack structure members together without holes
+
+fpcc-struct-return
+Common Report Var(flag_pcc_struct_return,1) VarExists
+Return small aggregates in memory, not registers
+
+fpeel-loops
+Common Report Var(flag_peel_loops)
+Perform loop peeling
+
+fpeephole
+Common Report Var(flag_no_peephole,0)
+Enable machine specific peephole optimizations
+
+fpeephole2
+Common Report Var(flag_peephole2)
+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) VarExists
+Generate position-independent code if possible (small mode)
+
+fpie
+Common Report Var(flag_pie,1) VarExists
+Generate position-independent code for executables if possible (small mode)
+
+fprefetch-loop-arrays
+Common Report Var(flag_prefetch_loop_arrays)
+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-generate
+Common
+Enable common options for generating profile info for profile feedback directed optimizations
+
+fprofile-use
+Common
+Enable common options for performing profile feedback directed optimizations
+
+fprofile-values
+Common Report Var(flag_profile_values)
+Insert code to profile values of expressions
+
+frandom-seed
+Common
+
+frandom-seed=
+Common Joined RejectNegative
+-frandom-seed=<string> Make compile reproducible using <string>
+
+freduce-all-givs
+Common Report Var(flag_reduce_all_givs)
+Strength reduce all loop general induction variables
+
+freg-struct-return
+Common Report Var(flag_pcc_struct_return,0) VarExists
+Return small aggregates in registers
+
+fregmove
+Common Report Var(flag_regmove)
+Enables a register move optimization
+
+frename-registers
+Common Report Var(flag_rename_registers)
+Perform a register renaming optimization pass
+
+freorder-blocks
+Common Report Var(flag_reorder_blocks)
+Reorder basic blocks to improve code placement
+
+freorder-blocks-and-partition
+Common Report Var(flag_reorder_blocks_and_partition)
+Reorder basic blocks and partition into hot and cold sections
+
+freorder-functions
+Common Report Var(flag_reorder_functions)
+Reorder functions to improve code placement
+
+frerun-cse-after-loop
+Common Report Var(flag_rerun_cse_after_loop)
+Add a common subexpression elimination pass after loop optimizations
+
+frerun-loop-opt
+Common Report Var(flag_rerun_loop_opt)
+Run the loop optimizer twice
+
+frounding-math
+Common Report Var(flag_rounding_math)
+Disable optimizations that assume default FP rounding behavior
+
+fsched-interblock
+Common Report Var(flag_schedule_interblock) Init(1)
+Enable scheduling across basic blocks
+
+fsched-spec
+Common Report Var(flag_schedule_speculative) Init(1)
+Allow speculative motion of non-loads
+
+fsched-spec-load
+Common Report Var(flag_schedule_speculative_load)
+Allow speculative motion of some loads
+
+fsched-spec-load-dangerous
+Common Report Var(flag_schedule_speculative_load_dangerous)
+Allow speculative motion of more loads
+
+fsched-verbose=
+Common RejectNegative Joined
+-fsched-verbose=<number> Set the verbosity level of the scheduler
+
+fsched2-use-superblocks
+Common Report Var(flag_sched2_use_superblocks)
+If scheduling post reload, do superblock scheduling
+
+fsched2-use-traces
+Common Report Var(flag_sched2_use_traces)
+If scheduling post reload, do trace scheduling
+
+fschedule-insns
+Common Report Var(flag_schedule_insns)
+Reschedule instructions before register allocation
+
+fschedule-insns2
+Common Report Var(flag_schedule_insns_after_reload)
+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 Report Var(flag_sched_stalled_insns)
+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)
+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
+
+fshared-data
+Common Report Var(flag_shared_data)
+Mark data as shared rather than private
+
+fsignaling-nans
+Common Report Var(flag_signaling_nans)
+Disable optimizations observable by IEEE signaling NaNs
+
+fsingle-precision-constant
+Common Report Var(flag_single_precision_constant)
+Convert floating point constants to single precision constants
+
+; Emit code to probe the stack, to help detect stack overflow; also
+; may cause large objects to be allocated dynamically.
+fstack-check
+Common Report Var(flag_stack_check)
+Insert stack checking code into the program
+
+fstack-limit
+Common
+
+fstack-limit-register=
+Common RejectNegative Joined
+-fstack-limit-register=<register> Trap if the stack goes past <register>
+
+fstack-limit-symbol=
+Common RejectNegative Joined
+-fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
+
+fstrength-reduce
+Common Report Var(flag_strength_reduce)
+Perform strength reduction optimizations
+
+; 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)
+Assume strict aliasing rules apply
+
+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)
+Perform jump threading optimizations
+
+ftime-report
+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
+
+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)
+Assume floating-point operations can trap
+
+ftrapv
+Common Report Var(flag_trapv)
+Trap for signed overflow in addition, subtraction and multiplication
+
+ftree-based-profiling
+Common Report Var(flag_tree_based_profiling)
+Use tree-ssa based implementation of profiling
+
+ftree-ccp
+Common Report Var(flag_tree_ccp)
+Enable SSA-CCP optimization on trees
+
+ftree-ch
+Common Report Var(flag_tree_ch)
+Enable loop header copying on trees
+
+ftree-combine-temps
+Common Report Var(flag_tree_combine_temps)
+Coalesce memory temporaries in the SSA->normal pass
+
+ftree-copyrename
+Common Report Var(flag_tree_copyrename)
+Replace SSA temporaries with better names in copies.
+
+ftree-dce
+Common Report Var(flag_tree_dce)
+Enable SSA dead code elimination optimization on trees
+
+ftree-dominator-opts
+Common Report Var(flag_tree_dom)
+Enable dominator optimizations
+
+ftree-dse
+Common Report Var(flag_tree_dse)
+Enable dead store elimination
+
+ftree-fre
+Common Report Var(flag_tree_fre)
+Enable Full Redundancy Elimination (FRE) on trees
+
+ftree-lim
+Common Report Var(flag_tree_lim) Init(1)
+Enable loop invariant motion on trees
+
+ftree-loop-optimize
+Common Report Var(flag_tree_loop_optimize) Init(1)
+Enable loop optimizations on tree level
+
+ftree-points-to=
+Common Joined RejectNegative
+
+ftree-pre
+Common Report Var(flag_tree_pre)
+Enable SSA-PRE optimization on trees
+
+ftree-sra
+Common Report Var(flag_tree_sra)
+Perform scalar replacement of aggregates
+
+ftree-ter
+Common Report Var(flag_tree_ter)
+Replace temporary expressions in the SSA->normal pass
+
+ftree-lrs
+Common Report Var(flag_tree_live_range_split)
+Perform live range splitting during the SSA->normal pass.
+
+funit-at-a-time
+Common Report Var(flag_unit_at_a_time)
+Compile whole compilation unit at a time
+
+funroll-loops
+Common Report Var(flag_unroll_loops)
+Perform loop unrolling when iteration count is known
+
+funroll-all-loops
+Common Report Var(flag_unroll_all_loops)
+Perform loop unrolling for all loops
+
+; 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)
+Allow math optimizations that may violate IEEE or ISO standards
+
+funswitch-loops
+Common Report Var(flag_unswitch_loops)
+Perform loop unswitching
+
+funwind-tables
+Common Report Var(flag_unwind_tables)
+Just generate unwind tables for exception handling
+
+fvar-tracking
+Common Report Var(flag_var_tracking) VarExists
+Perform variable tracking
+
+ftree-vectorize
+Common Report Var(flag_tree_vectorize)
+Enable loop vectorization on trees
+
+; -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
+-fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
+
+
+fvpt
+Common Report Var(flag_value_profile_transformations)
+Use expression value profiles in optimizations
+
+fweb
+Common Report Var(flag_web) VarExists
+Construct webs and split unrelated uses of single variable
+
+fwrapv
+Common Report Var(flag_wrapv)
+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
+Generate debug information in COFF format
+
+gdwarf-2
+Common JoinedOrMissing
+Generate debug information in DWARF v2 format
+
+ggdb
+Common JoinedOrMissing
+Generate debug information in default extended format
+
+gstabs
+Common JoinedOrMissing
+Generate debug information in STABS format
+
+gstabs+
+Common JoinedOrMissing
+Generate debug information in extended STABS format
+
+gvms
+Common JoinedOrMissing
+Generate debug information in VMS format
+
+gxcoff
+Common JoinedOrMissing
+Generate debug information in XCOFF format
+
+gxcoff+
+Common JoinedOrMissing
+Generate debug information in extended XCOFF format
+
+m
+Common Joined
+
+o
+Common Joined Separate
+-o <file> Place output into <file>
+
+p
+Common Var(profile_flag)
+Enable function profiling
+
+pedantic
+Common Var(pedantic)
+Issue warnings needed for strict compliance to the standard
+
+pedantic-errors
+Common
+Like -pedantic but issue them as errors
+
+quiet
+Common Var(quiet_flag)
+Do not display functions compiled or elapsed time
+
+version
+Common Var(version_flag)
+Display the compiler's version
+
+w
+Common Var(inhibit_warnings)
+Suppress warnings
+