This section describes the command-line options that are only meaningful
for C++ programs. You can also use most of the GNU compiler options
regardless of what language your program is in. For example, you
-might compile a file @code{firstClass.C} like this:
+might compile a file @file{firstClass.C} like this:
@smallexample
g++ -g -frepo -O -c firstClass.C
as introduced in C++14. This is useful for user-defined replacement
deallocation functions that, for example, use the size of the object
to make deallocation faster. Enabled by default under
-@samp{-std=c++14} and above. The flag @option{-Wsized-deallocation}
+@option{-std=c++14} and above. The flag @option{-Wsized-deallocation}
warns about places that might want to add a definition.
@item -fstats
Warn when a string or character literal is followed by a ud-suffix which does
not begin with an underscore. As a conforming extension, GCC treats such
suffixes as separate preprocessing tokens in order to maintain backwards
-compatibility with code that uses formatting macros from @code{<inttypes.h>}.
+compatibility with code that uses formatting macros from
+the standard header file @file{inttypes.h}.
For example:
@smallexample
This section describes the command-line options that are only meaningful
for Objective-C and Objective-C++ programs. You can also use most of
the language-independent GNU compiler options.
-For example, you might compile a file @code{some_class.m} like this:
+For example, you might compile a file @file{some_class.m} like this:
@smallexample
gcc -g -fgnu-runtime -O -c some_class.m
@opindex Wno-uninitialized
Warn if an automatic variable is used without first being initialized
or if a variable may be clobbered by a @code{setjmp} call. In C++,
-warn if a non-static reference or non-static @samp{const} member
+warn if a non-static reference or non-static @code{const} member
appears in a class without constructors.
If you want to warn about code that uses the uninitialized value of the
The @samp{U} integer constant suffix, or the @samp{F} or @samp{L} floating-point
constant suffixes. (Traditional C does support the @samp{L} suffix on integer
constants.) Note, these suffixes appear in macros defined in the system
-headers of most modern systems, e.g.@: the @samp{_MIN}/@samp{_MAX} macros in @code{<limits.h>}.
+headers of most modern systems, e.g.@: the @samp{_MIN}/@samp{_MAX} macros in
+@file{limits.h}.
Use of these macros in user code might normally lead to spurious
warnings, however GCC's integrated preprocessor has enough context to
avoid warning in these cases.
Produce compressed debug sections in DWARF format, if that is supported.
If @var{type} is not given, the default type depends on the capabilities
of the assembler and linker used. @var{type} may be one of
-@option{none} (don't compress debug sections), @option{zlib} (use zlib
-compression in ELF gABI format), or @option{zlib-gnu} (use zlib
+@samp{none} (don't compress debug sections), @samp{zlib} (use zlib
+compression in ELF gABI format), or @samp{zlib-gnu} (use zlib
compression in traditional GNU format). If the linker doesn't support
writing compressed debug sections, the option is rejected. Otherwise,
if the assembler does not support them, @option{-gz} is silently ignored
@env{GCC_COMPARE_DEBUG} from taking effect.
To verify full coverage during @option{-fcompare-debug} testing, set
-@env{GCC_COMPARE_DEBUG} to say @samp{-fcompare-debug-not-overridden},
+@env{GCC_COMPARE_DEBUG} to say @option{-fcompare-debug-not-overridden},
which GCC rejects as an invalid option in any actual compilation
(rather than preprocessing, assembly or linking). To get just a
warning, setting @env{GCC_COMPARE_DEBUG} to @samp{-w%n-fcompare-debug
Attempt to transform conditional jumps into branch-less equivalents. This
includes use of conditional moves, min, max, set flags and abs instructions, and
some tricks doable by standard arithmetics. The use of conditional execution
-on chips where it is available is controlled by @code{if-conversion2}.
+on chips where it is available is controlled by @option{-fif-conversion2}.
Enabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
@item -fvect-cost-model=@var{model}
@opindex fvect-cost-model
Alter the cost model used for vectorization. The @var{model} argument
-should be one of @code{unlimited}, @code{dynamic} or @code{cheap}.
-With the @code{unlimited} model the vectorized code-path is assumed
-to be profitable while with the @code{dynamic} model a runtime check
+should be one of @samp{unlimited}, @samp{dynamic} or @samp{cheap}.
+With the @samp{unlimited} model the vectorized code-path is assumed
+to be profitable while with the @samp{dynamic} model a runtime check
guards the vectorized code-path to enable it only for iteration
counts that will likely execute faster than when executing the original
-scalar loop. The @code{cheap} model disables vectorization of
+scalar loop. The @samp{cheap} model disables vectorization of
loops where doing so would be cost prohibitive for example due to
required runtime checks for data dependence or alignment but otherwise
-is equal to the @code{dynamic} model.
+is equal to the @samp{dynamic} model.
The default cost model depends on other optimization flags and is
-either @code{dynamic} or @code{cheap}.
+either @samp{dynamic} or @samp{cheap}.
@item -fsimd-cost-model=@var{model}
@opindex fsimd-cost-model
Alter the cost model used for vectorization of loops marked with the OpenMP
or Cilk Plus simd directive. The @var{model} argument should be one of
-@code{unlimited}, @code{dynamic}, @code{cheap}. All values of @var{model}
+@samp{unlimited}, @samp{dynamic}, @samp{cheap}. All values of @var{model}
have the same meaning as described in @option{-fvect-cost-model} and by
default a cost model defined with @option{-fvect-cost-model} is used.
and those merged by attribute @code{externally_visible} become static functions
and in effect are optimized more aggressively by interprocedural optimizers.
-This option should not be used in combination with @code{-flto}.
+This option should not be used in combination with @option{-flto}.
Instead relying on a linker plugin should provide safer and more precise
information.
@file{libfoo.a}, it is possible to extract and use them in an LTO link if you
are using a linker with plugin support. To create static libraries suitable
for LTO, use @command{gcc-ar} and @command{gcc-ranlib} instead of @command{ar}
-and @code{ranlib}; to show the symbols of object files with GIMPLE bytecode, use
+and @command{ranlib};
+to show the symbols of object files with GIMPLE bytecode, use
@command{gcc-nm}. Those commands require that @command{ar}, @command{ranlib}
and @command{nm} have been compiled with plugin support. At link time, use the the
flag @option{-fuse-linker-plugin} to ensure that the library participates in
are extracted and linked as usual, but they do not participate
in the LTO optimization process. In order to make a static library suitable
for both LTO optimization and usual linkage, compile its object files with
-@option{-flto} @code{-ffat-lto-objects}.
+@option{-flto} @option{-ffat-lto-objects}.
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
@item -flto-partition=@var{alg}
@opindex flto-partition
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) or @code{max} to create
-new partition for every symbol where possible. Specifying @code{none}
+The value is either @samp{1to1} to specify a partitioning mirroring
+the original source files or @samp{balanced} to specify partitioning
+into equally sized chunks (whenever possible) or @samp{max} to create
+new partition for every symbol where possible. Specifying @samp{none}
as an algorithm disables partitioning and streaming completely.
-The default value is @code{balanced}. While @code{1to1} can be used
-as an workaround for various code ordering issues, the @code{max}
+The default value is @samp{balanced}. While @samp{1to1} can be used
+as an workaround for various code ordering issues, the @samp{max}
partitioning is intended for internal testing only.
-The value @code{one} specifies that exactly one partition should be
-used while the value @code{none} bypasses partitioning and executes
+The value @samp{one} specifies that exactly one partition should be
+used while the value @samp{none} bypasses partitioning and executes
the link-time optimization step directly from the WPA phase.
@item -flto-odr-type-merging
more code to the link-time optimizer. This information specifies what
symbols can be accessed externally (by non-LTO object or during dynamic
linking). Resulting code quality improvements on binaries (and shared
-libraries that use hidden visibility) are similar to @code{-fwhole-program}.
+libraries that use hidden visibility) are similar to @option{-fwhole-program}.
See @option{-flto} for a description of the effect of this flag and how to
use it.
Only use these options when there are significant benefits from doing
so. When you specify these options, the assembler and linker
create larger object and executable files and are also slower.
-You cannot use @code{gprof} on all systems if you
+You cannot use @command{gprof} on all systems if you
specify this option, and you may have problems with debugging if
you specify both this option and @option{-g}.
@opindex nodefaultlibs
Do not use the standard system libraries when linking.
Only the libraries you specify are passed to the linker, and options
-specifying linkage of the system libraries, such as @code{-static-libgcc}
-or @code{-shared-libgcc}, are ignored.
+specifying linkage of the system libraries, such as @option{-static-libgcc}
+or @option{-shared-libgcc}, are ignored.
The standard startup files are used normally, unless @option{-nostartfiles}
is used.
Do not use the standard system startup files or libraries when linking.
No startup files and only the libraries you specify are passed to
the linker, and options specifying linkage of the system libraries, such as
-@code{-static-libgcc} or @code{-shared-libgcc}, are ignored.
+@option{-static-libgcc} or @option{-shared-libgcc}, are ignored.
The compiler may generate calls to @code{memcmp}, @code{memset},
@code{memcpy} and @code{memmove}.
@item %p
Substitutes the standard macro predefinitions for the
-current target machine. Use this when running @code{cpp}.
+current target machine. Use this when running @command{cpp}.
@item %P
Like @samp{%p}, but puts @samp{__} before and after the name of each
@item %1
Process the @code{cc1} spec. This is used to construct the options to be
-passed to the actual C compiler (@samp{cc1}).
+passed to the actual C compiler (@command{cc1}).
@item %2
Process the @code{cc1plus} spec. This is used to construct the options to be
-passed to the actual C++ compiler (@samp{cc1plus}).
+passed to the actual C++ compiler (@command{cc1plus}).
@item %*
Substitute the variable part of a matched option. See below.
@end smallexample
@noindent
-when matching an option like @code{-mcu=newchip} produces:
+when matching an option like @option{-mcu=newchip} produces:
@smallexample
--script=newchip/memory.ld
@item -mbarrel-shifter
@opindex mbarrel-shifter
Generate instructions supported by barrel shifter. This is the default
-unless @samp{-mcpu=ARC601} is in effect.
+unless @option{-mcpu=ARC601} is in effect.
@item -mcpu=@var{cpu}
@opindex mcpu
@opindex mA7
@opindex mARC700
Compile for ARC700. Aliases: @option{-mA7}, @option{-mARC700}.
-This is the default when configured with @samp{--with-cpu=arc700}@.
+This is the default when configured with @option{--with-cpu=arc700}@.
@end table
@item -mdpfp
@opindex mea
Generate Extended arithmetic instructions. Currently only
@code{divaw}, @code{adds}, @code{subs}, and @code{sat16} are
-supported. This is always enabled for @samp{-mcpu=ARC700}.
+supported. This is always enabled for @option{-mcpu=ARC700}.
@item -mno-mpy
@opindex mno-mpy
@item -mmul64
@opindex mmul64
-Generate mul64 and mulu64 instructions. Only valid for @samp{-mcpu=ARC600}.
+Generate mul64 and mulu64 instructions. Only valid for @option{-mcpu=ARC600}.
@item -mnorm
@opindex mnorm
-Generate norm instruction. This is the default if @samp{-mcpu=ARC700}
+Generate norm instruction. This is the default if @option{-mcpu=ARC700}
is in effect.
@item -mspfp
@item -msimd
@opindex msimd
Enable generation of ARC SIMD instructions via target-specific
-builtins. Only valid for @samp{-mcpu=ARC700}.
+builtins. Only valid for @option{-mcpu=ARC700}.
@item -msoft-float
@opindex msoft-float
@opindex mlra
Enable Local Register Allocation. This is still experimental for ARC,
so by default the compiler uses standard reload
-(i.e. @samp{-mno-lra}).
+(i.e. @option{-mno-lra}).
@item -mlra-priority-none
@opindex mlra-priority-none
@item -mbarrel_shifter
@opindex mbarrel_shifter
-Replaced by @samp{-mbarrel-shifter}
+Replaced by @option{-mbarrel-shifter}.
@item -mdpfp_compact
@opindex mdpfp_compact
-Replaced by @samp{-mdpfp-compact}
+Replaced by @option{-mdpfp-compact}.
@item -mdpfp_fast
@opindex mdpfp_fast
-Replaced by @samp{-mdpfp-fast}
+Replaced by @option{-mdpfp-fast}.
@item -mdsp_packa
@opindex mdsp_packa
-Replaced by @samp{-mdsp-packa}
+Replaced by @option{-mdsp-packa}.
@item -mEA
@opindex mEA
-Replaced by @samp{-mea}
+Replaced by @option{-mea}.
@item -mmac_24
@opindex mmac_24
-Replaced by @samp{-mmac-24}
+Replaced by @option{-mmac-24}.
@item -mmac_d16
@opindex mmac_d16
-Replaced by @samp{-mmac-d16}
+Replaced by @option{-mmac-d16}.
@item -mspfp_compact
@opindex mspfp_compact
-Replaced by @samp{-mspfp-compact}
+Replaced by @option{-mspfp-compact}.
@item -mspfp_fast
@opindex mspfp_fast
-Replaced by @samp{-mspfp-fast}
+Replaced by @option{-mspfp-fast}.
@item -mtune=@var{cpu}
@opindex mtune
@item -multcost=@var{num}
@opindex multcost
-Replaced by @samp{-mmultcost}.
+Replaced by @option{-mmultcost}.
@end table
@item -mtp=@var{name}
@opindex mtp
Specify the access model for the thread local storage pointer. The valid
-models are @option{soft}, which generates calls to @code{__aeabi_read_tp},
-@option{cp15}, which fetches the thread pointer from @code{cp15} directly
-(supported in the arm6k architecture), and @option{auto}, which uses the
+models are @samp{soft}, which generates calls to @code{__aeabi_read_tp},
+@samp{cp15}, which fetches the thread pointer from @code{cp15} directly
+(supported in the arm6k architecture), and @samp{auto}, which uses the
best available method for the selected processor. The default setting is
-@option{auto}.
+@samp{auto}.
@item -mtls-dialect=@var{dialect}
@opindex mtls-dialect
@opindex mmcu
Specify Atmel AVR instruction set architectures (ISA) or MCU type.
-The default for this option is@tie{}@code{avr2}.
+The default for this option is@tie{}@samp{avr2}.
GCC supports the following AVR devices and ISAs:
@opindex mrelax
Try to replace @code{CALL} resp.@: @code{JMP} instruction by the shorter
@code{RCALL} resp.@: @code{RJMP} instruction if applicable.
-Setting @code{-mrelax} just adds the @code{--relax} option to the
+Setting @option{-mrelax} just adds the @option{--relax} option to the
linker command line when the linker is called.
Jump relaxing is performed by the linker because jump offsets are not
This option is used internally by the compiler to select and
build multilibs for architectures @code{avr2} and @code{avr25}.
These architectures mix devices with and without @code{SPH}.
-For any setting other than @code{-mmcu=avr2} or @code{-mmcu=avr25}
+For any setting other than @option{-mmcu=avr2} or @option{-mmcu=avr25}
the compiler driver adds or removes this option from the compiler
proper's command line, because the compiler then knows if the device
or architecture has an 8-bit stack pointer and thus no @code{SPH}
@item
Linker relaxation must be turned on so that the linker generates
the stubs correctly in all situations. See the compiler option
-@code{-mrelax} and the linker option @code{--relax}.
+@option{-mrelax} and the linker option @option{--relax}.
There are corner cases where the linker is supposed to generate stubs
but aborts without relaxation and without a helpful error message.
@}
@end example
-and the application be linked with @code{-Wl,--defsym,func_4=0x4}.
+and the application be linked with @option{-Wl,--defsym,func_4=0x4}.
Alternatively, @code{func_4} can be defined in the linker script.
@end itemize
GCC defines several built-in macros so that the user code can test
for the presence or absence of features. Almost any of the following
built-in macros are deduced from device capabilities and thus
-triggered by the @code{-mmcu=} command-line option.
+triggered by the @option{-mmcu=} command-line option.
For even more AVR-specific built-in macros see
@ref{AVR Named Address Spaces} and @ref{AVR Built-in Functions}.
@item __AVR_ARCH__
Build-in macro that resolves to a decimal number that identifies the
-architecture and depends on the @code{-mmcu=@var{mcu}} option.
+architecture and depends on the @option{-mmcu=@var{mcu}} option.
Possible values are:
@code{2}, @code{25}, @code{3}, @code{31}, @code{35},
@code{avr6}, @code{avrxmega2}, @code{avrxmega4}, @code{avrxmega5},
@code{avrxmega6}, @code{avrxmega7}, respectively.
If @var{mcu} specifies a device, this built-in macro is set
-accordingly. For example, with @code{-mmcu=atmega8} the macro is
+accordingly. For example, with @option{-mmcu=atmega8} the macro is
defined to @code{4}.
@item __AVR_@var{Device}__
-Setting @code{-mmcu=@var{device}} defines this built-in macro which reflects
-the device's name. For example, @code{-mmcu=atmega8} defines the
-built-in macro @code{__AVR_ATmega8__}, @code{-mmcu=attiny261a} defines
+Setting @option{-mmcu=@var{device}} defines this built-in macro which reflects
+the device's name. For example, @option{-mmcu=atmega8} defines the
+built-in macro @code{__AVR_ATmega8__}, @option{-mmcu=attiny261a} defines
@code{__AVR_ATtiny261A__}, etc.
The built-in macros' names follow
the scheme @code{__AVR_@var{Device}__} where @var{Device} is
the device name as from the AVR user manual. The difference between
@var{Device} in the built-in macro and @var{device} in
-@code{-mmcu=@var{device}} is that the latter is always lowercase.
+@option{-mmcu=@var{device}} is that the latter is always lowercase.
If @var{device} is not a device but only a core architecture like
-@code{avr51}, this macro is not defined.
+@samp{avr51}, this macro is not defined.
@item __AVR_DEVICE_NAME__
-Setting @code{-mmcu=@var{device}} defines this built-in macro to
-the device's name. For example, with @code{-mmcu=atmega8} the macro
+Setting @option{-mmcu=@var{device}} defines this built-in macro to
+the device's name. For example, with @option{-mmcu=atmega8} the macro
is defined to @code{atmega8}.
If @var{device} is not a device but only a core architecture like
-@code{avr51}, this macro is not defined.
+@samp{avr51}, this macro is not defined.
@item __AVR_XMEGA__
The device / architecture belongs to the XMEGA family of devices.
@itemx __AVR_HAVE_16BIT_SP__
The stack pointer (SP) register is treated as 8-bit respectively
16-bit register by the compiler.
-The definition of these macros is affected by @code{-mtiny-stack}.
+The definition of these macros is affected by @option{-mtiny-stack}.
@item __AVR_HAVE_SPH__
@itemx __AVR_SP8__
The device has the SPH (high part of stack pointer) special function
register or has an 8-bit stack pointer, respectively.
-The definition of these macros is affected by @code{-mmcu=} and
-in the cases of @code{-mmcu=avr2} and @code{-mmcu=avr25} also
-by @code{-msp8}.
+The definition of these macros is affected by @option{-mmcu=} and
+in the cases of @option{-mmcu=avr2} and @option{-mmcu=avr25} also
+by @option{-msp8}.
@item __AVR_HAVE_RAMPD__
@itemx __AVR_HAVE_RAMPX__
@code{RAMPZ} special function register, respectively.
@item __NO_INTERRUPTS__
-This macro reflects the @code{-mno-interrupts} command line option.
+This macro reflects the @option{-mno-interrupts} command line option.
@item __AVR_ERRATA_SKIP__
@itemx __AVR_ERRATA_SKIP_JMP_CALL__
@item __WITH_AVRLIBC__
The compiler is configured to be used together with AVR-Libc.
-See the @code{--with-avrlibc} configure option.
+See the @option{--with-avrlibc} configure option.
@end table
@opindex ffix-and-continue
@opindex findirect-data
Generate code suitable for fast turnaround development, such as to
-allow GDB to dynamically load @code{.o} files into already-running
+allow GDB to dynamically load @file{.o} files into already-running
programs. @option{-findirect-data} and @option{-ffix-and-continue}
are provided for backwards compatibility.
@item -force_cpusubtype_ALL
@opindex force_cpusubtype_ALL
-This causes GCC's output file to have the @var{ALL} subtype, instead of
+This causes GCC's output file to have the @samp{ALL} subtype, instead of
one controlled by the @option{-mcpu} or @option{-march} option.
@item -allowable_client @var{client_name}
option.
Library code that is intended to operate with more than one UNIX
-standard must test, set and restore the variable @var{__xpg4_extended_mask}
+standard must test, set and restore the variable @code{__xpg4_extended_mask}
as appropriate. Most GNU software doesn't provide this capability.
@item -nolibdld
Support thread-safe exception handling on MinGW. Programs that rely
on thread-safe exception handling must compile and link all code with the
@option{-mthreads} option. When compiling, @option{-mthreads} defines
-@code{-D_MT}; when linking, it links in a special thread helper library
+@option{-D_MT}; when linking, it links in a special thread helper library
@option{-lmingwthrd} which cleans up per-thread exception-handling data.
@item -mno-align-stringops
@item -mflush-func=@var{name}
@opindex mflush-func=@var{name}
Specifies the name of the operating system function to call to flush
-the cache. The default is @emph{_flush_cache}, but a function call
+the cache. The default is @samp{_flush_cache}, but a function call
is only used if a trap is not available.
@item -mno-flush-func
@var{arch} is compatible with @var{cpu}. Other combinations of
@option{-mcpu} and @option{-march} are rejected.
-GCC defines the macro @samp{__mcf_cpu_@var{cpu}} when ColdFire target
-@var{cpu} is selected. It also defines @samp{__mcf_family_@var{family}},
+GCC defines the macro @code{__mcf_cpu_@var{cpu}} when ColdFire target
+@var{cpu} is selected. It also defines @code{__mcf_family_@var{family}},
where the value of @var{family} is given by the table above.
@item -mtune=@var{tune}
as well. These two options select the same tuning decisions as
@option{-m68020-40} and @option{-m68020-60} respectively.
-GCC defines the macros @samp{__mc@var{arch}} and @samp{__mc@var{arch}__}
+GCC defines the macros @code{__mc@var{arch}} and @code{__mc@var{arch}__}
when tuning for 680x0 architecture @var{arch}. It also defines
-@samp{mc@var{arch}} unless either @option{-ansi} or a non-GNU @option{-std}
+@code{mc@var{arch}} unless either @option{-ansi} or a non-GNU @option{-std}
option is used. If GCC is tuning for a range of architectures,
as selected by @option{-mtune=68020-40} or @option{-mtune=68020-60},
it defines the macros for every architecture in the range.
-GCC also defines the macro @samp{__m@var{uarch}__} when tuning for
+GCC also defines the macro @code{__m@var{uarch}__} when tuning for
ColdFire microarchitecture @var{uarch}, where @var{uarch} is one
of the arguments given above.
@opindex m68881
Generate floating-point instructions. This is the default for 68020
and above, and for ColdFire devices that have an FPU@. It defines the
-macro @samp{__HAVE_68881__} on M680x0 targets and @samp{__mcffpu__}
+macro @code{__HAVE_68881__} on M680x0 targets and @code{__mcffpu__}
on ColdFire targets.
@item -msoft-float
example, the default is ``off'' for @option{-mcpu=5206} and ``on'' for
@option{-mcpu=5206e}.
-GCC defines the macro @samp{__mcfhwdiv__} when this option is enabled.
+GCC defines the macro @code{__mcfhwdiv__} when this option is enabled.
@item -mshort
@opindex mshort
@item -mc=@var{name}
@opindex mc=
Selects which section constant data is placed in. @var{name} may
-be @code{tiny}, @code{near}, or @code{far}.
+be @samp{tiny}, @samp{near}, or @samp{far}.
@item -mclip
@opindex mclip
-Enables the @code{clip} instruction. Note that @code{-mclip} is not
-useful unless you also provide @code{-mminmax}.
+Enables the @code{clip} instruction. Note that @option{-mclip} is not
+useful unless you also provide @option{-mminmax}.
@item -mconfig=@var{name}
@opindex mconfig=
@code{MeP-Integrator} tool, not part of GCC, provides these
configurations through this option; using this option is the same as
using all the corresponding command-line options. The default
-configuration is @code{default}.
+configuration is @samp{default}.
@item -mcop
@opindex mcop
Enables the coprocessor instructions. By default, this is a 32-bit
coprocessor. Note that the coprocessor is normally enabled via the
-@code{-mconfig=} option.
+@option{-mconfig=} option.
@item -mcop32
@opindex mcop32
@item -mno-opts
@opindex mno-opts
-Disables all the optional instructions enabled by @code{-mall-opts}.
+Disables all the optional instructions enabled by @option{-mall-opts}.
@item -mrepeat
@opindex mrepeat
accepted as synonyms for @samp{@var{n}f1_1}.
GCC defines two macros based on the value of this option. The first
-is @samp{_MIPS_ARCH}, which gives the name of target architecture, as
-a string. The second has the form @samp{_MIPS_ARCH_@var{foo}},
-where @var{foo} is the capitalized value of @samp{_MIPS_ARCH}@.
-For example, @option{-march=r2000} sets @samp{_MIPS_ARCH}
-to @samp{"r2000"} and defines the macro @samp{_MIPS_ARCH_R2000}.
+is @code{_MIPS_ARCH}, which gives the name of target architecture, as
+a string. The second has the form @code{_MIPS_ARCH_@var{foo}},
+where @var{foo} is the capitalized value of @code{_MIPS_ARCH}@.
+For example, @option{-march=r2000} sets @code{_MIPS_ARCH}
+to @code{"r2000"} and defines the macro @code{_MIPS_ARCH_R2000}.
-Note that the @samp{_MIPS_ARCH} macro uses the processor names given
+Note that the @code{_MIPS_ARCH} macro uses the processor names given
above. In other words, it has the full prefix and does not
abbreviate @samp{000} as @samp{k}. In the case of @samp{from-abi},
-the macro names the resolved architecture (either @samp{"mips1"} or
-@samp{"mips3"}). It names the default architecture when no
+the macro names the resolved architecture (either @code{"mips1"} or
+@code{"mips3"}). It names the default architecture when no
@option{-march} option is given.
@item -mtune=@var{arch}
runs on a family of processors, but optimize the code for one
particular member of that family.
-@option{-mtune} defines the macros @samp{_MIPS_TUNE} and
-@samp{_MIPS_TUNE_@var{foo}}, which work in the same way as the
+@option{-mtune} defines the macros @code{_MIPS_TUNE} and
+@code{_MIPS_TUNE_@var{foo}}, which work in the same way as the
@option{-march} ones described above.
@item -mips1
configurations, where it may select a special set of libraries
that lack all floating-point support (including, for example, the
floating-point @code{printf} formats).
-If code compiled with @code{-mno-float} accidentally contains
+If code compiled with @option{-mno-float} accidentally contains
floating-point operations, it is likely to suffer a link-time
or run-time failure.
@opindex mno-odd-spreg
Enable the use of odd-numbered single-precision floating-point registers
for the o32 ABI. This is the default for processors that are known to
-support these registers. When using the o32 FPXX ABI, @code{-mno-odd-spreg}
+support these registers. When using the o32 FPXX ABI, @option{-mno-odd-spreg}
is set by default.
@item -mabs=2008
@opindex mno-dsp
Use (do not use) revision 1 of the MIPS DSP ASE@.
@xref{MIPS DSP Built-in Functions}. This option defines the
-preprocessor macro @samp{__mips_dsp}. It also defines
-@samp{__mips_dsp_rev} to 1.
+preprocessor macro @code{__mips_dsp}. It also defines
+@code{__mips_dsp_rev} to 1.
@item -mdspr2
@itemx -mno-dspr2
@opindex mno-dspr2
Use (do not use) revision 2 of the MIPS DSP ASE@.
@xref{MIPS DSP Built-in Functions}. This option defines the
-preprocessor macros @samp{__mips_dsp} and @samp{__mips_dspr2}.
-It also defines @samp{__mips_dsp_rev} to 2.
+preprocessor macros @code{__mips_dsp} and @code{__mips_dspr2}.
+It also defines @code{__mips_dsp_rev} to 2.
@item -msmartmips
@itemx -mno-smartmips
memory range for which the cache is being flushed, the size of the
memory range, and the number 3 (to flush both caches). The default
depends on the target GCC was configured for, but commonly is either
-@samp{_flush_func} or @samp{__cpu_flush}.
+@code{_flush_func} or @code{__cpu_flush}.
@item mbranch-cost=@var{num}
@opindex mbranch-cost
enabled) are generated when @code{__builtin___clear_cache()} is
compiled.
-This option defaults to @code{-mno-synci}, but the default can be
-overridden by configuring with @code{--with-synci}.
+This option defaults to @option{-mno-synci}, but the default can be
+overridden by configuring GCC with @option{--with-synci}.
When compiling code for single processor systems, it is generally safe
to use @code{synci}. However, on many multi-core (SMP) systems, it
@option{-mrelax-pic-calls} is the default if GCC was configured to use
an assembler and a linker that support the @code{.reloc} assembly
-directive and @code{-mexplicit-relocs} is in effect. With
-@code{-mno-explicit-relocs}, this optimization can be performed by the
+directive and @option{-mexplicit-relocs} is in effect. With
+@option{-mno-explicit-relocs}, this optimization can be performed by the
assembler and the linker alone without help from the compiler.
@item -mmcount-ra-address
@opindex mliw
Allow the compiler to generate @emph{Long Instruction Word}
instructions if the target is the @samp{AM33} or later. This is the
-default. This option defines the preprocessor macro @samp{__LIW__}.
+default. This option defines the preprocessor macro @code{__LIW__}.
@item -mnoliw
@opindex mnoliw
Do not allow the compiler to generate @emph{Long Instruction Word}
instructions. This option defines the preprocessor macro
-@samp{__NO_LIW__}.
+@code{__NO_LIW__}.
@item -msetlb
@opindex msetlb
Allow the compiler to generate the @emph{SETLB} and @emph{Lcc}
instructions if the target is the @samp{AM33} or later. This is the
-default. This option defines the preprocessor macro @samp{__SETLB__}.
+default. This option defines the preprocessor macro @code{__SETLB__}.
@item -mnosetlb
@opindex mnosetlb
Do not allow the compiler to generate @emph{SETLB} or @emph{Lcc}
instructions. This option defines the preprocessor macro
-@samp{__NO_SETLB__}.
+@code{__NO_SETLB__}.
@end table
Select the MCU to target. This is used to create a C preprocessor
symbol based upon the MCU name, converted to upper case and pre- and
post-fixed with @samp{__}. This in turn is used by the
-@code{msp430.h} header file to select an MCU-specific supplementary
+@file{msp430.h} header file to select an MCU-specific supplementary
header file.
The option also sets the ISA to use. If the MCU name is one that is
known to only support the 430 ISA then that is selected, otherwise the
-430X ISA is selected. A generic MCU name of @code{msp430} can also be
-used to select the 430 ISA. Similarly the generic @code{msp430x} MCU
+430X ISA is selected. A generic MCU name of @samp{msp430} can also be
+used to select the 430 ISA. Similarly the generic @samp{msp430x} MCU
name selects the 430X ISA.
In addition an MCU-specific linker script is added to the linker
@item -mcpu=
@opindex mcpu=
-Specifies the ISA to use. Accepted values are @code{msp430},
-@code{msp430x} and @code{msp430xv2}. This option is deprecated. The
+Specifies the ISA to use. Accepted values are @samp{msp430},
+@samp{msp430x} and @samp{msp430xv2}. This option is deprecated. The
@option{-mmcu=} option should be used to select the ISA.
@item -msim
@item mhwmult=
@opindex mhwmult=
Describes the type of hardware multiply supported by the target.
-Accepted values are @code{none} for no hardware multiply, @code{16bit}
+Accepted values are @samp{none} for no hardware multiply, @samp{16bit}
for the original 16-bit-only multiply supported by early MCUs.
-@code{32bit} for the 16/32-bit multiply supported by later MCUs and
-@code{f5series} for the 16/32-bit multiply supported by F5-series MCUs.
-A value of @code{auto} can also be given. This tells GCC to deduce
+@samp{32bit} for the 16/32-bit multiply supported by later MCUs and
+@samp{f5series} for the 16/32-bit multiply supported by F5-series MCUs.
+A value of @samp{auto} can also be given. This tells GCC to deduce
the hardware multiply support based upon the MCU name provided by the
@option{-mmcu} option. If no @option{-mmcu} option is specified then
-@code{32bit} hardware multiply support is assumed. @code{auto} is the
+@samp{32bit} hardware multiply support is assumed. @samp{auto} is the
default setting.
Hardware multiplies are normally performed by calling a library
routine. This saves space in the generated code. When compiling at
-@code{-O3} or higher however the hardware multiplier is invoked
+@option{-O3} or higher however the hardware multiplier is invoked
inline. This makes for bigger, but faster code.
The hardware multiply routines disable interrupts whilst running and
@opindex mno-custom-@var{insn}
Each @option{-mcustom-@var{insn}=@var{N}} option enables use of a
custom instruction with encoding @var{N} when generating code that uses
-@var{insn}. For example, @code{-mcustom-fadds=253} generates custom
+@var{insn}. For example, @option{-mcustom-fadds=253} generates custom
instruction 253 for single-precision floating-point add operations instead
of the default behavior of using a library call.
@itemx -mmul=rl78
@opindex mmul
Specifies the type of hardware multiplication support to be used. The
-default is @code{none}, which uses software multiplication functions.
-The @code{g13} option is for the hardware multiply/divide peripheral
-only on the RL78/G13 targets. The @code{rl78} option is for the
+default is @samp{none}, which uses software multiplication functions.
+The @samp{g13} option is for the hardware multiply/divide peripheral
+only on the RL78/G13 targets. The @samp{rl78} option is for the
standard hardware multiplication defined in the RL78 software manual.
@item -m64bit-doubles
operations on the general-purpose registers for architectures that
support it.
-The argument @var{yes} or @var{single} enables the use of
+The argument @samp{yes} or @samp{single} enables the use of
single-precision floating-point operations.
-The argument @var{double} enables the use of single and
+The argument @samp{double} enables the use of single and
double-precision floating-point operations.
-The argument @var{no} disables floating-point operations on the
+The argument @samp{no} disables floating-point operations on the
general-purpose registers.
This option is currently only available on the MPC854x.
@item -mabi=@var{abi-type}
@opindex mabi
Extend the current ABI with a particular extension, or remove such extension.
-Valid values are @var{altivec}, @var{no-altivec}, @var{spe},
-@var{no-spe}, @var{ibmlongdouble}, @var{ieeelongdouble},
-@var{elfv1}, @var{elfv2}@.
+Valid values are @samp{altivec}, @samp{no-altivec}, @samp{spe},
+@samp{no-spe}, @samp{ibmlongdouble}, @samp{ieeelongdouble},
+@samp{elfv1}, @samp{elfv2}@.
@item -mabi=spe
@opindex mabi=spe
On System V.4 and embedded PowerPC systems assume that all calls to
variable argument functions are properly prototyped. Otherwise, the
compiler must insert an instruction before every non-prototyped call to
-set or clear bit 6 of the condition code register (@var{CR}) to
+set or clear bit 6 of the condition code register (@code{CR}) to
indicate whether floating-point values are passed in the floating-point
registers in case the function takes variable arguments. With
@option{-mprototype}, only calls to prototyped variable argument functions
@item -memb
@opindex memb
-On embedded PowerPC systems, set the @var{PPC_EMB} bit in the ELF flags
+On embedded PowerPC systems, set the @code{PPC_EMB} bit in the ELF flags
header to indicate that @samp{eabi} extended relocations are used.
@item -meabi
@item -mveclibabi=@var{type}
@opindex mveclibabi
Specifies the ABI type to use for vectorizing intrinsics using an
-external library. The only type supported at present is @code{mass},
+external library. The only type supported at present is @samp{mass},
which specifies to use IBM's Mathematical Acceleration Subsystem
(MASS) libraries for vectorizing intrinsics using external libraries.
GCC currently emits calls to @code{acosd2}, @code{acosf4},
@itemx -mno-pointers-to-nested-functions
@opindex mpointers-to-nested-functions
Generate (do not generate) code to load up the static chain register
-(@var{r11}) when calling through a pointer on AIX and 64-bit Linux
+(@code{r11}) when calling through a pointer on AIX and 64-bit Linux
systems where a function pointer points to a 3-word descriptor giving
-the function address, TOC value to be loaded in register @var{r2}, and
-static chain value to be loaded in register @var{r11}. The
+the function address, TOC value to be loaded in register @code{r2}, and
+static chain value to be loaded in register @code{r11}. The
@option{-mpointers-to-nested-functions} is on by default. You cannot
call through pointers to nested functions or pointers
to functions compiled in other languages that use the static chain if
@opindex fpu
@opindex nofpu
Enables (@option{-fpu}) or disables (@option{-nofpu}) the use of RX
-floating-point hardware. The default is enabled for the @var{RX600}
-series and disabled for the @var{RX200} series.
+floating-point hardware. The default is enabled for the RX600
+series and disabled for the RX200 series.
Floating-point instructions are only generated for 32-bit floating-point
values, however, so the FPU hardware is not used for doubles if the
@item -mcpu=@var{name}
@opindex mcpu
Selects the type of RX CPU to be targeted. Currently three types are
-supported, the generic @var{RX600} and @var{RX200} series hardware and
-the specific @var{RX610} CPU. The default is @var{RX600}.
+supported, the generic @samp{RX600} and @samp{RX200} series hardware and
+the specific @samp{RX610} CPU. The default is @samp{RX600}.
-The only difference between @var{RX600} and @var{RX610} is that the
-@var{RX610} does not support the @code{MVTIPL} instruction.
+The only difference between @samp{RX600} and @samp{RX610} is that the
+@samp{RX610} does not support the @code{MVTIPL} instruction.
-The @var{RX200} series does not have a hardware floating-point unit
+The @samp{RX200} series does not have a hardware floating-point unit
and so @option{-nofpu} is enabled by default when this type is
selected.
@opindex mfsca
@opindex mno-fsca
Allow or disallow the compiler to emit the @code{fsca} instruction for sine
-and cosine approximations. The option @code{-mfsca} must be used in
-combination with @code{-funsafe-math-optimizations}. It is enabled by default
-when generating code for SH4A. Using @code{-mno-fsca} disables sine and cosine
-approximations even if @code{-funsafe-math-optimizations} is in effect.
+and cosine approximations. The option @option{-mfsca} must be used in
+combination with @option{-funsafe-math-optimizations}. It is enabled by default
+when generating code for SH4A. Using @option{-mno-fsca} disables sine and cosine
+approximations even if @option{-funsafe-math-optimizations} is in effect.
@item -mfsrra
@itemx -mno-fsrra
@opindex mfsrra
@opindex mno-fsrra
Allow or disallow the compiler to emit the @code{fsrra} instruction for
-reciprocal square root approximations. The option @code{-mfsrra} must be used
-in combination with @code{-funsafe-math-optimizations} and
-@code{-ffinite-math-only}. It is enabled by default when generating code for
-SH4A. Using @code{-mno-fsrra} disables reciprocal square root approximations
-even if @code{-funsafe-math-optimizations} and @code{-ffinite-math-only} are
+reciprocal square root approximations. The option @option{-mfsrra} must be used
+in combination with @option{-funsafe-math-optimizations} and
+@option{-ffinite-math-only}. It is enabled by default when generating code for
+SH4A. Using @option{-mno-fsrra} disables reciprocal square root approximations
+even if @option{-funsafe-math-optimizations} and @option{-ffinite-math-only} are
in effect.
@item -mpretend-cmove
@itemx -mno-8byte-align
@opindex m8byte-align
@opindex mno-8byte-align
-Enables support for @code{doubles} and @code{long long} types to be
+Enables support for @code{double} and @code{long long} types to be
aligned on 8-byte boundaries. The default is to restrict the
alignment of all objects to at most 4-bytes. When
@option{-m8byte-align} is in effect the C preprocessor symbol
@opindex finstrument-functions-exclude-file-list
Set the list of functions that are excluded from instrumentation (see
-the description of @code{-finstrument-functions}). If the file that
+the description of @option{-finstrument-functions}). If the file that
contains a function definition matches with one of @var{file}, then
that function is not instrumented. The match is done on substrings:
if the @var{file} parameter is a substring of the file name, it is
@noindent
excludes any inline function defined in files whose pathnames
-contain @code{/bits/stl} or @code{include/sys}.
+contain @file{/bits/stl} or @file{include/sys}.
-If, for some reason, you want to include letter @code{','} in one of
-@var{sym}, write @code{'\,'}. For example,
-@code{-finstrument-functions-exclude-file-list='\,\,tmp'}
+If, for some reason, you want to include letter @samp{,} in one of
+@var{sym}, write @samp{\,}. For example,
+@option{-finstrument-functions-exclude-file-list='\,\,tmp'}
(note the single quote surrounding the option).
@item -finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{}
@opindex finstrument-functions-exclude-function-list
-This is similar to @code{-finstrument-functions-exclude-file-list},
+This is similar to @option{-finstrument-functions-exclude-file-list},
but this option sets the list of function names to be excluded from
instrumentation. The function name to be matched is its user-visible
name, such as @code{vector<int> blah(const vector<int> &)}, not the
operating system or the language runtime must do that. The switch causes
generation of code to ensure that they see the stack being extended.
-You can additionally specify a string parameter: @code{no} means no
-checking, @code{generic} means force the use of old-style checking,
-@code{specific} means use the best checking method and is equivalent
+You can additionally specify a string parameter: @samp{no} means no
+checking, @samp{generic} means force the use of old-style checking,
+@samp{specific} means use the best checking method and is equivalent
to bare @option{-fstack-check}.
Old-style checking is a generic mechanism that requires no specific
@end enumerate
Note that old-style stack checking is also the fallback method for
-@code{specific} if no target support has been added in the compiler.
+@samp{specific} if no target support has been added in the compiler.
@item -fstack-limit-register=@var{reg}
@itemx -fstack-limit-symbol=@var{sym}
@item -ftls-model=@var{model}
@opindex ftls-model
Alter the thread-local storage model to be used (@pxref{Thread-Local}).
-The @var{model} argument should be one of @code{global-dynamic},
-@code{local-dynamic}, @code{initial-exec} or @code{local-exec}.
+The @var{model} argument should be one of @samp{global-dynamic},
+@samp{local-dynamic}, @samp{initial-exec} or @samp{local-exec}.
Note that the choice is subject to optimization: the compiler may use
a more efficient model for symbols not visible outside of the translation
unit, or if @option{-fpic} is not given on the command line.
-The default without @option{-fpic} is @code{initial-exec}; with
-@option{-fpic} the default is @code{global-dynamic}.
+The default without @option{-fpic} is @samp{initial-exec}; with
+@option{-fpic} the default is @samp{global-dynamic}.
@item -fvisibility=@var{default|internal|hidden|protected}
@opindex fvisibility
It is @strong{strongly} recommended that you use this in any shared objects
you distribute.
-Despite the nomenclature, @code{default} always means public; i.e.,
+Despite the nomenclature, @samp{default} always means public; i.e.,
available to be linked against from outside the shared object.
-@code{protected} and @code{internal} are pretty useless in real-world
-usage so the only other commonly used option is @code{hidden}.
+@samp{protected} and @samp{internal} are pretty useless in real-world
+usage so the only other commonly used option is @samp{hidden}.
The default if @option{-fvisibility} isn't specified is
-@code{default}, i.e., make every
+@samp{default}, i.e., make every
symbol public---this causes the same behavior as previous versions of
GCC@.
projects / gcc.git / commitdiff