@item Overall Options
@xref{Overall Options,,Options Controlling the Kind of Output}.
@smallexample
--c -S -E -o @var{file} -pipe -v -x @var{language}
+-c -S -E -o @var{file} -pipe -v --help -x @var{language}
@end smallexample
@item C Language Options
@xref{C Dialect Options,,Options Controlling C Dialect}.
@smallexample
--ansi -fallow-single-precision -fcond-mismatch -fno-asm
+-ansi -flang-isoc9x -fallow-single-precision -fcond-mismatch -fno-asm
-fno-builtin -ffreestanding -fhosted -fsigned-bitfields -fsigned-char
-funsigned-bitfields -funsigned-char -fwritable-strings
-traditional -traditional-cpp -trigraphs
-Wimplicit-function-declaration -Wimport
-Werror-implicit-function-declaration -Winline
-Wlarger-than-@var{len} -Wlong-long
--Wmain -Wmissing-declarations
+-Wmain -Wmissing-declarations -Wmissing-noreturn
-Wmissing-prototypes -Wmultichar -Wnested-externs -Wno-import
-Wno-non-template-friend -Wold-style-cast -Woverloaded-virtual
-Wparentheses -Wpointer-arith -Wredundant-decls -Wreorder
-mprolog-function -mno-prolog-function -mspace
-mtda=@var{n} -msda=@var{n} -mzda=@var{n}
-mv850 -mbig-switch
+
+@emph{NS32K Options}
+-m32032 -m32332 -m32532 -m32081 -m32381 -mmult-add -mnomult-add
+-msoft-float -mrtd -mnortd -mregparam -mnoregparam -msb -mnosb
+-mbitfield -mnobitfield -mhimem -mnohimem
@end smallexample
@item Code Generation Options
-fverbose-asm -fpack-struct -fstack-check
-fargument-alias -fargument-noalias
-fargument-noalias-global
+-fleading-underscore
@end smallexample
@end table
various stages of compilation. This fails to work on some systems where
the assembler is unable to read from a pipe; but the GNU assembler has
no trouble.
+
+@item --help
+Print (on the standard output) a description of the command line options
+understood by @code{gcc}. If the @code{-v} option is also specified
+then @code{--help} will also be passed on to the various processes
+invoked by @code{gcc}, so that they can display the command line options
+they accept. If the @code{-W} option is also specified then command
+line options which have no documentation associated with them will also
+be displayed.
@end table
@node Invoking G++
The functions @code{alloca}, @code{abort}, @code{exit}, and
@code{_exit} are not builtin functions when @samp{-ansi} is used.
+@item -flang-isoc9x
+Enable support for features found in the C9X standard. In particular,
+enable support for the C9X @code{restrict} keyword.
+
+Even when this option is not specified, you can still use some C9X
+features in so far as they do not conflict with previous C standards.
+For example, you may use @code{__restrict__} even when -flang-isoc9x
+is not specified.
+
@item -fno-asm
Do not recognize @code{asm}, @code{inline} or @code{typeof} as a
keyword, so that code can use these words as identifiers. You can use
Use this option to detect global functions that are not declared in
header files.
+@item -Wmissing-noreturn
+Warn about functions which might be candidates for attribute @code{noreturn}.
+Note these are only possible candidates, not absolute ones. Care should
+be taken to manually verify functions actually do not ever return before
+adding the @code{noreturn} attribute, otherwise subtle code generation
+bugs could be introduced.
+
@item -Wredundant-decls
Warn if anything is declared more than once in the same scope, even in
cases where multiple declaration is valid and changes nothing.
* System V Options::
* V850 Options::
* ARC Options::
+* NS32K Options::
@end menu
@node M680x0 Options
@end table
+@node NS32K Options
+@subsection NS32K Options
+@cindex NS32K options
+
+These are the @samp{-m} options defined for the 32000 series. The default
+values for these options depends on which style of 32000 was selected when
+the compiler was configured; the defaults for the most common choices are
+given below.
+
+@table @code
+@item -m32032
+@itemx -m32032
+Generate output for a 32032. This is the default
+when the compiler is configured for 32032 and 32016 based systems.
+
+@item -m32332
+@itemx -m32332
+Generate output for a 32332. This is the default
+when the compiler is configured for 32332-based systems.
+
+@item -m32532
+@itemx -m32532
+Generate output for a 32532. This is the default
+when the compiler is configured for 32532-based systems.
+
+@item -m32081
+Generate output containing 32081 instructions for floating point.
+This is the default for all systems.
+
+@item -m32381
+Generate output containing 32381 instructions for floating point. This
+also implies @samp{-m32081}. The 32381 is only compatible with the 32332
+and 32532 cpus. This is the default for the pc532-netbsd configuration.
+
+@item -mmulti-add
+Try and generate multiply-add floating point instructions @code{polyF}
+and @code{dotF}. This option is only available if the @samp{-m32381}
+option is in effect. Using these instructions requires changes to to
+register allocation which generally has a negative impact on
+performance. This option should only be enabled when compiling code
+particularly likely to make heavy use of multiply-add instructions.
+
+@item -mnomulti-add
+Do not try and generate multiply-add floating point instructions
+@code{polyF} and @code{dotF}. This is the default on all platforms.
+
+@item -msoft-float
+Generate output containing library calls for floating point.
+@strong{Warning:} the requisite libraries may not be available.
+
+@item -mnobitfield
+Do not use the bit-field instructions. On some machines it is faster to
+use shifting and masking operations. This is the default for the pc532.
+
+@item -mbitfield
+Do use the bit-field instructions. This is the default for all platforms
+except the pc532.
+
+@item -mrtd
+Use a different function-calling convention, in which functions
+that take a fixed number of arguments return pop their
+arguments on return with the @code{ret} instruction.
+
+This calling convention is incompatible with the one normally
+used on Unix, so you cannot use it if you need to call libraries
+compiled with the Unix compiler.
+
+Also, you must provide function prototypes for all functions that
+take variable numbers of arguments (including @code{printf});
+otherwise incorrect code will be generated for calls to those
+functions.
+
+In addition, seriously incorrect code will result if you call a
+function with too many arguments. (Normally, extra arguments are
+harmlessly ignored.)
+
+This option takes its name from the 680x0 @code{rtd} instruction.
+
+
+@item -mregparam
+Use a different function-calling convention where the first two arguments
+are passed in registers.
+
+This calling convention is incompatible with the one normally
+used on Unix, so you cannot use it if you need to call libraries
+compiled with the Unix compiler.
+
+@item -mnoregparam
+Do not pass any arguments in registers. This is the default for all
+targets.
+
+@item -msb
+It is OK to use the sb as an index register which is always loaded with
+zero. This is the default for the pc532-netbsd target.
+
+@item -mnosb
+The sb register is not available for use or has not been initialized to
+zero by the run time system. This is the default for all targets except
+the pc532-netbsd. It is also implied whenever @samp{-mhimem} or
+@samp{-fpic} is set.
+
+@item -mhimem
+Many ns32000 series addressing modes use displacements of up to 512MB.
+If an address is above 512MB then displacements from zero can not be used.
+This option causes code to be generated which can be loaded above 512MB.
+This may be useful for operating systems or ROM code.
+
+@item -mnohimem
+Assume code will be loaded in the first 512MB of virtual address space.
+This is the default for all platforms.
+
+
+@end table
+
+
@node Code Gen Options
@section Options for Code Generation Conventions
variables that do not live across a call. Functions compiled this way
will not save and restore the register @var{reg}.
-Use of this flag for a register that has a fixed pervasive role in the
-machine's execution model, such as the stack pointer or frame pointer,
-will produce disastrous results.
+It is an error to used this flag with the frame pointer or stack pointer.
+Use of this flag for other registers that have fixed pervasive roles in
+the machine's execution model will produce disastrous results.
This flag does not have a negative form, because it specifies a
three-way choice.
live across a call. Functions compiled this way will save and restore
the register @var{reg} if they use it.
-Use of this flag for a register that has a fixed pervasive role in the
-machine's execution model, such as the stack pointer or frame pointer,
-will produce disastrous results.
+It is an error to used this flag with the frame pointer or stack pointer.
+Use of this flag for other registers that have fixed pervasive roles in
+the machine's execution model will produce disastrous results.
A different sort of disaster will result from the use of this flag for
a register in which function values may be returned.
Each language will automatically use whatever option is required by
the language standard. You should not need to use these options yourself.
+
+@item -fleading-underscore
+This option and its counterpart, -fno-leading-underscore, forcibly
+change the way C symbols are represented in the object file. One use
+is to help link with legacy assembly code.
+
+Be warned that you should know what you are doing when invoking this
+option, and that not all targets provide complete support for it.
@end table
@node Environment Variables