-fobjc-direct-dispatch @gol
-fobjc-exceptions @gol
-fobjc-gc @gol
+-fobjc-std=objc1 @gol
-freplace-objc-classes @gol
-fzero-link @gol
-gen-decls @gol
@item Warning Options
@xref{Warning Options,,Options to Request or Suppress Warnings}.
-@gccoptlist{-fsyntax-only -pedantic -pedantic-errors @gol
+@gccoptlist{-fsyntax-only fmax-errors=@var{n} -pedantic @gol
+-pedantic-errors @gol
-w -Wextra -Wall -Waddress -Waggregate-return -Warray-bounds @gol
-Wno-attributes -Wno-builtin-macro-redefined @gol
-Wc++-compat -Wc++0x-compat -Wcast-align -Wcast-qual @gol
-fdelayed-branch -fdelete-null-pointer-checks -fdse -fdse @gol
-fearly-inlining -fipa-sra -fexpensive-optimizations -ffast-math @gol
-ffinite-math-only -ffloat-store -fexcess-precision=@var{style} @gol
--fforward-propagate -ffunction-sections @gol
+-fforward-propagate -ffp-contract=@var{style} -ffunction-sections @gol
-fgcse -fgcse-after-reload -fgcse-las -fgcse-lm -fgraphite-identity @gol
-fgcse-sm -fif-conversion -fif-conversion2 -findirect-inlining @gol
-finline-functions -finline-functions-called-once -finline-limit=@var{n} @gol
-fno-ira-share-spill-slots -fira-verbose=@var{n} @gol
-fivopts -fkeep-inline-functions -fkeep-static-consts @gol
-floop-block -floop-flatten -floop-interchange -floop-strip-mine @gol
--floop-parallelize-all -flto -flto-compression-level -flto-partition=@var{alg} @gol
--flto-report -fltrans -fltrans-output-list -fmerge-all-constants @gol
+-floop-parallelize-all -flto -flto-compression-level
+-flto-partition=@var{alg} -flto-report -fmerge-all-constants @gol
-fmerge-constants -fmodulo-sched -fmodulo-sched-allow-regmoves @gol
-fmove-loop-invariants fmudflap -fmudflapir -fmudflapth -fno-branch-count-reg @gol
-fno-default-inline @gol
-funit-at-a-time -funroll-all-loops -funroll-loops @gol
-funsafe-loop-optimizations -funsafe-math-optimizations -funswitch-loops @gol
-fvariable-expansion-in-unroller -fvect-cost-model -fvpt -fweb @gol
--fwhole-program -fwhopr[=@var{n}] -fwpa -fuse-linker-plugin @gol
+-fwhole-program -fwpa -fuse-linker-plugin @gol
--param @var{name}=@var{value}
-O -O0 -O1 -O2 -O3 -Os -Ofast}
-mcld -mcx16 -msahf -mmovbe -mcrc32 -mrecip -mvzeroupper @gol
-mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -msse4 -mavx @gol
-maes -mpclmul -mfsgsbase -mrdrnd -mf16c -mfused-madd @gol
--msse4a -m3dnow -mpopcnt -mabm -mfma4 -mxop -mlwp @gol
+-msse4a -m3dnow -mpopcnt -mabm -mbmi -mtbm -mfma4 -mxop -mlwp @gol
-mthreads -mno-align-stringops -minline-all-stringops @gol
-minline-stringops-dynamically -mstringop-strategy=@var{alg} @gol
-mpush-args -maccumulate-outgoing-args -m128bit-long-double @gol
-mint16 -mno-int32 -mfloat32 -mno-float64 @gol
-mfloat64 -mno-float32 -mabshi -mno-abshi @gol
-mbranch-expensive -mbranch-cheap @gol
--msplit -mno-split -munix-asm -mdec-asm}
+-munix-asm -mdec-asm}
@emph{picoChip Options}
@gccoptlist{-mae=@var{ae_type} -mvliw-lookahead=@var{N} @gol
GNU runtime has a different garbage collection implementation that
does not require special compiler flags.
+@item -fobjc-std=objc1
+@opindex fobjc-std
+Conform to the language syntax of Objective-C 1.0, the language
+recognized by GCC 4.0. This only affects the Objective-C additions to
+the C/C++ language; it does not affect conformance to C/C++ standards,
+which is controlled by the separate C/C++ dialect option flags. When
+this option is used with the Objective-C or Objective-C++ compiler,
+any Objective-C syntax that is not recognized by GCC 4.0 is rejected.
+This is useful if you need to make sure that your Objective-C code can
+be compiled with older versions of GCC.
+
@item -freplace-objc-classes
@opindex freplace-objc-classes
Emit a special marker instructing @command{ld(1)} not to statically link in
@opindex fsyntax-only
Check the code for syntax errors, but don't do anything beyond that.
+@item -fmax-errors=@var{n}
+@opindex fmax-errors
+Limits the maximum number of error messages to @var{n}, at which point
+GCC bails out rather than attempting to continue processing the source
+code. If @var{n} is 0 (the default), there is no limit on the number
+of error messages produced. If @option{-Wfatal-errors} is also
+specified, then @option{-Wfatal-errors} takes precedence over this
+option.
+
@item -w
@opindex w
Inhibit all warning messages.
This option is enabled by default at optimization levels @option{-O},
@option{-O2}, @option{-O3}, @option{-Os}.
+@item -ffp-contract=@var{style}
+@opindex ffp-contract
+@option{-ffp-contract=off} disables floating-point expression contraction.
+@option{-ffp-contract=fast} enables floating-point expression contraction
+such as forming of fused multiply-add operations if the target has
+native support for them.
+@option{-ffp-contract=on} enables floating-point expression contraction
+if allowed by the language standard. This is currently not implemented
+and treated equal to @option{-ffp-contract=off}.
+
+The default is @option{-ffp-contract=fast}.
+
@item -fomit-frame-pointer
@opindex fomit-frame-pointer
Don't keep the frame pointer in a register for functions that
and in effect are optimized more aggressively by interprocedural optimizers. If @command{gold} is used as the linker plugin, @code{externally_visible} attributes are automatically added to functions (not variable yet due to a current @command{gold} issue) that are accessed outside of LTO objects according to resolution file produced by @command{gold}. For other linkers that cannot generate resolution file, explicit @code{externally_visible} attributes are still necessary.
While this option is equivalent to proper use of the @code{static} keyword for
programs consisting of a single file, in combination with option
-@option{-flto} or @option{-fwhopr} this flag can be used to
+@option{-flto} this flag can be used to
compile many smaller scale programs since the functions and variables become
local for the whole combined compilation unit, not for the single source file
itself.
This option implies @option{-fwhole-file} for Fortran programs.
-@item -flto
+@item -flto[=@var{n}]
@opindex flto
This option runs the standard link-time optimizer. When invoked
with source code, it generates GIMPLE (one of GCC's internal
optimizations the @option{-flto} flag needs to be passed to both the
compile and the link commands.
+To make whole program optimization effective, it is necesary to make
+certain whole program assumptions. The compiler needs to know
+what functions and variables can be accessed by libraries and runtime
+outside of the link time optimized unit. When supported by the linker,
+the linker plugin (see @option{-fuse-linker-plugin}) passes to the
+compiler information about used and externally visible symbols. When
+the linker plugin is not available, @option{-fwhole-program} should be
+used to allow the compiler to make these assumptions, which will lead
+to more aggressive optimization decisions.
+
Note that when a file is compiled with @option{-flto}, the generated
object file will be larger than a regular object file because it will
contain GIMPLE bytecodes and the usual final code. This means that
will be extracted and linked as usual, but they will not participate
in the LTO optimization process.
-Link time optimizations do not require the presence of the whole
-program to operate. If the program does not require any symbols to
-be exported, it is possible to combine @option{-flto} and
-@option{-fwhopr} with @option{-fwhole-program} to allow the
-interprocedural optimizers to use more aggressive assumptions which
-may lead to improved optimization opportunities.
+Link time optimizations do not require the presence of the whole program to
+operate. If the program does not require any symbols to be exported, it is
+possible to combine @option{-flto} and with @option{-fwhole-program} to allow
+the interprocedural optimizers to use more aggressive assumptions which may
+lead to improved optimization opportunities.
+Use of @option{-fwhole-program} is not needed when linker plugin is
+active (see @option{-fuse-linker-plugin}).
Regarding portability: the current implementation of LTO makes no
attempt at generating bytecode that can be ported between different
GCC will not work with an older/newer version of GCC.
Link time optimization does not play well with generating debugging
-information. Combining @option{-flto} or @option{-fwhopr} with
-@option{-g} is experimental.
+information. Combining @option{-flto} with
+@option{-g} is currently experimental and expected to produce wrong
+results.
-This option is disabled by default.
+If you specify the optional @var{n}, the optimization and code
+generation done at link time is executed in parallel using @var{n}
+parallel jobs by utilizing an installed @command{make} program. The
+environment variable @env{MAKE} may be used to override the program
+used. The default value for @var{n} is 1.
-@item -fwhopr[=@var{n}]
-@opindex fwhopr
-This option is identical in functionality to @option{-flto} but it
-differs in how the final link stage is executed. Instead of loading
-all the function bodies in memory, the callgraph is analyzed and
-optimization decisions are made (whole program analysis or WPA). Once
-optimization decisions are made, the callgraph is partitioned and the
-different sections are compiled separately (local transformations or
-LTRANS)@. This process allows optimizations on very large programs
-that otherwise would not fit in memory. This option enables
-@option{-fwpa} and @option{-fltrans} automatically.
-
-If you specify the optional @var{n} the link stage is executed in
-parallel using @var{n} parallel jobs by utilizing an installed
-@command{make} program. The environment variable @env{MAKE} may be
-used to override the program used.
-
-You can also specify @option{-fwhopr=jobserver} to use GNU make's
+You can also specify @option{-flto=jobserver} to use GNU make's
job server mode to determine the number of parallel jobs. This
-is useful when the Makefile calling GCC is already parallel.
+is useful when the Makefile calling GCC is already executing in parallel.
The parent Makefile will need a @samp{+} prepended to the command recipe
for this to work. This will likely only work if @env{MAKE} is
GNU make.
-Disabled by default.
+This option is disabled by default.
@item -flto-partition=@var{alg}
@opindex flto-partition
-Specify partitioning algorithm used by @option{-fwhopr} mode. The value is
-either @code{1to1} to specify partitioning corresponding to source files
-or @code{balanced} to specify partitioning into, if possible, equally sized
-chunks. The default value is @code{balanced}.
-
-@item -fwpa
-@opindex fwpa
-This is an internal option used by GCC when compiling with
-@option{-fwhopr}. You should never need to use it.
-
-This option runs the link-time optimizer in the whole-program-analysis
-(WPA) mode, which reads in summary information from all inputs and
-performs a whole-program analysis based on summary information only.
-It generates object files for subsequent runs of the link-time
-optimizer where individual object files are optimized using both
-summary information from the WPA mode and the actual function bodies.
-It then drives the LTRANS phase.
-
-Disabled by default.
-
-@item -fltrans
-@opindex fltrans
-This is an internal option used by GCC when compiling with
-@option{-fwhopr}. You should never need to use it.
-
-This option runs the link-time optimizer in the local-transformation (LTRANS)
-mode, which reads in output from a previous run of the LTO in WPA mode.
-In the LTRANS mode, LTO optimizes an object and produces the final assembly.
-
-Disabled by default.
-
-@item -fltrans-output-list=@var{file}
-@opindex fltrans-output-list
-This is an internal option used by GCC when compiling with
-@option{-fwhopr}. You should never need to use it.
-
-This option specifies a file to which the names of LTRANS output files are
-written. This option is only meaningful in conjunction with @option{-fwpa}.
-
-Disabled by default.
+Specify the partitioning algorithm used by the link time optimizer.
+The value is either @code{1to1} to specify a partitioning mirroring
+the original source files or @code{balanced} to specify partitioning
+into equally sized chunks (whenever possible). Specifying @code{none}
+as an algorithm disables partitioning and streaming completely. The
+default value is @code{balanced}.
@item -flto-compression-level=@var{n}
This option specifies the level of compression used for intermediate
language written to LTO object files, and is only meaningful in
-conjunction with LTO mode (@option{-fwhopr}, @option{-flto}). Valid
+conjunction with LTO mode (@option{-flto}). Valid
values are 0 (no compression) to 9 (maximum compression). Values
outside this range are clamped to either 0 or 9. If the option is not
given, a default balanced compression setting is used.
Prints a report with internal details on the workings of the link-time
optimizer. The contents of this report vary from version to version,
it is meant to be useful to GCC developers when processing object
-files in LTO mode (via @option{-fwhopr} or @option{-flto}).
+files in LTO mode (via @option{-flto}).
Disabled by default.
@item early-inlining-insns
Specify growth that early inliner can make. In effect it increases amount of
-inlining for code having large abstraction penalty. The default value is 8.
+inlining for code having large abstraction penalty. The default value is 10.
@item max-early-inliner-iterations
@itemx max-early-inliner-iterations
indirect calls early inliner can resolve. Deeper chains are still handled by
late inlining.
+@item comdat-sharing-probability
+@itemx comdat-sharing-probability
+Probability (in percent) that C++ inline function with comdat visibility
+will be shared acroess multiple compilation units. The default value is 20.
+
@item min-vect-loop-bound
The minimum number of iterations under which a loop will not get vectorized
when @option{-ftree-vectorize} is used. The number of iterations after
@itemx -mno-popcnt
@itemx -mabm
@itemx -mno-abm
+@itemx -mbmi
+@itemx -mno-bmi
+@itemx -mtbm
+@itemx -mno-tbm
@opindex mmmx
@opindex mno-mmx
@opindex msse
@opindex mno-3dnow
These switches enable or disable the use of instructions in the MMX,
SSE, SSE2, SSE3, SSSE3, SSE4.1, AVX, AES, PCLMUL, FSGSBASE, RDRND,
-F16C, SSE4A, FMA4, XOP, LWP, ABM or 3DNow!@: extended instruction sets.
+F16C, SSE4A, FMA4, XOP, LWP, ABM, BMI, or 3DNow!@: extended instruction sets.
These extensions are also available as built-in functions: see
@ref{X86 Built-in Functions}, for details of the functions enabled and
disabled by these switches.
@samp{34kc}, @samp{34kf2_1}, @samp{34kf1_1},
@samp{74kc}, @samp{74kf2_1}, @samp{74kf1_1}, @samp{74kf3_2},
@samp{1004kc}, @samp{1004kf2_1}, @samp{1004kf1_1},
-@samp{loongson2e}, @samp{loongson2f},
+@samp{loongson2e}, @samp{loongson2f}, @samp{loongson3a},
@samp{m4k},
@samp{octeon},
@samp{orion},
@opindex mbranch-cheap
Do not pretend that branches are expensive. This is the default.
-@item -msplit
-@opindex msplit
-Generate code for a system with split I&D@.
-
-@item -mno-split
-@opindex mno-split
-Generate code for a system without split I&D@. This is the default.
-
@item -munix-asm
@opindex munix-asm
Use Unix assembler syntax. This is the default when configured for
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