@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.
@item -fcheck-memory-usage
Generate extra code to check each memory access. GNU CC will generate
code that is suitable for a detector of bad memory accesses such as
-@file{Checker}. If you specify this option, you can not use the
-@code{asm} or @code{__asm__} keywords.
+@file{Checker}.
You must also specify this option when you compile functions you call that
have side effects. If you do not, you may get erroneous messages from
stubs for every function you call, you may have to specify
@samp{-fcheck-memory-usage} without @samp{-fprefix-function-name}.
+If you specify this option, you can not use the @code{asm} or
+@code{__asm__} keywords in functions with memory checking enabled. The
+compiler cannot understand what the @code{asm} statement will do, and
+therefore cannot generate the appropriate code, so it is rejected.
+However, the function attribute @code{no_check_memory_usage} will
+disable memory checking within a function, and @code{asm} statements can
+be put inside such functions. Inline expansion of a non-checked
+function within a checked function is permitted; the inline function's
+memory accesses won't be checked, but the rest will.
+
+If you move your @code{asm} statements to non-checked inline functions,
+but they do access memory, you can add calls to the support code in your
+inline function, to indicate any reads, writes, or copies being done.
+These calls would be similar to those done in the stubs described above.
+
+@c FIXME: The support-routine interface is defined by the compiler and
+@c should be documented!
+
@item -fprefix-function-name
Request GNU CC to add a prefix to the symbols generated for function names.
GNU CC adds a prefix to the names of functions defined as well as
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
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