@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-@c 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+@c 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
@c Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@c man begin COPYRIGHT
Copyright @copyright{} 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
-fno-nonansi-builtins -fno-operator-names @gol
-fno-optional-diags -fpermissive @gol
-fno-pretty-templates @gol
--frepo -fno-rtti -fstats -ftemplate-depth-@var{n} @gol
+-frepo -fno-rtti -fstats -ftemplate-depth=@var{n} @gol
-fno-threadsafe-statics -fuse-cxa-atexit -fno-weak -nostdinc++ @gol
-fno-default-inline -fvisibility-inlines-hidden @gol
-fvisibility-ms-compat @gol
--Wabi -Wctor-dtor-privacy @gol
+-Wabi -Wconversion-null -Wctor-dtor-privacy @gol
-Wnon-virtual-dtor -Wreorder @gol
-Weffc++ -Wstrict-null-sentinel @gol
-Wno-non-template-friend -Wold-style-cast @gol
-Wno-attributes -Wno-builtin-macro-redefined @gol
-Wc++-compat -Wc++0x-compat -Wcast-align -Wcast-qual @gol
-Wchar-subscripts -Wclobbered -Wcomment @gol
--Wconversion -Wcoverage-mismatch -Wno-deprecated @gol
+-Wconversion -Wcoverage-mismatch -Wcpp -Wno-deprecated @gol
-Wno-deprecated-declarations -Wdisabled-optimization @gol
-Wno-div-by-zero -Wempty-body -Wenum-compare -Wno-endif-labels @gol
-Werror -Werror=* @gol
-Wstrict-overflow -Wstrict-overflow=@var{n} @gol
-Wswitch -Wswitch-default -Wswitch-enum -Wsync-nand @gol
-Wsystem-headers -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized @gol
--Wunknown-pragmas -Wno-pragmas -Wunreachable-code @gol
+-Wunknown-pragmas -Wno-pragmas @gol
-Wunsuffixed-float-constants -Wunused -Wunused-function @gol
-Wunused-label -Wunused-parameter -Wno-unused-result -Wunused-value -Wunused-variable @gol
--Wvariadic-macros -Wvla @gol
+-Wunused-but-set-parameter -Wunused-but-set-variable -Wvariadic-macros -Wvla @gol
-Wvolatile-register-var -Wwrite-strings}
@item C and Objective-C-only Warning Options
-frandom-seed=@var{string} -fsched-verbose=@var{n} @gol
-fsel-sched-verbose -fsel-sched-dump-cfg -fsel-sched-pipelining-verbose @gol
-ftest-coverage -ftime-report -fvar-tracking @gol
--fvar-tracking-assigments -fvar-tracking-assignments-toggle @gol
+-fvar-tracking-assignments -fvar-tracking-assignments-toggle @gol
-g -g@var{level} -gtoggle -gcoff -gdwarf-@var{version} @gol
-ggdb -gstabs -gstabs+ -gstrict-dwarf -gno-strict-dwarf @gol
-gvms -gxcoff -gxcoff+ @gol
-freciprocal-math -fregmove -frename-registers -freorder-blocks @gol
-freorder-blocks-and-partition -freorder-functions @gol
-frerun-cse-after-loop -freschedule-modulo-scheduled-loops @gol
--frounding-math -fsched2-use-superblocks @gol
--fsched2-use-traces -fsched-pressure @gol
+-frounding-math -fsched2-use-superblocks -fsched-pressure @gol
-fsched-spec-load -fsched-spec-load-dangerous @gol
-fsched-stalled-insns-dep[=@var{n}] -fsched-stalled-insns[=@var{n}] @gol
-fsched-group-heuristic -fsched-critical-path-heuristic @gol
-fshort-double -fshort-wchar @gol
-fverbose-asm -fpack-struct[=@var{n}] -fstack-check @gol
-fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol
--fno-stack-limit -fargument-alias -fargument-noalias @gol
--fargument-noalias-global -fargument-noalias-anything @gol
+-fno-stack-limit @gol
-fleading-underscore -ftls-model=@var{model} @gol
-ftrapv -fwrapv -fbounds-check @gol
-fvisibility}
@cindex ISO support
@item -ansi
@opindex ansi
-In C mode, this is equivalent to @samp{-std=c89}. In C++ mode, it is
+In C mode, this is equivalent to @samp{-std=c90}. In C++ mode, it is
equivalent to @samp{-std=c++98}.
This turns off certain features of GCC that are incompatible with ISO
Supported by GCC}, for details of these standard versions. This option
is currently only supported when compiling C or C++.
-The compiler can accept several base standards, such as @samp{c89} or
+The compiler can accept several base standards, such as @samp{c90} or
@samp{c++98}, and GNU dialects of those standards, such as
-@samp{gnu89} or @samp{gnu++98}. By specifying a base standard, the
+@samp{gnu90} or @samp{gnu++98}. By specifying a base standard, the
compiler will accept all programs following that standard and those
using GNU extensions that do not contradict it. For example,
-@samp{-std=c89} turns off certain features of GCC that are
+@samp{-std=c90} turns off certain features of GCC that are
incompatible with ISO C90, such as the @code{asm} and @code{typeof}
keywords, but not other GNU extensions that do not have a meaning in
ISO C90, such as omitting the middle term of a @code{?:}
strict-conforming programs may be rejected. The particular standard
is used by @option{-pedantic} to identify which features are GNU
extensions given that version of the standard. For example
-@samp{-std=gnu89 -pedantic} would warn about C++ style @samp{//}
+@samp{-std=gnu90 -pedantic} would warn about C++ style @samp{//}
comments, while @samp{-std=gnu99 -pedantic} would not.
A value for this option must be provided; possible values are
@table @samp
-@item c89
+@item c90
+@itemx c89
@itemx iso9899:1990
Support all ISO C90 programs (certain GNU extensions that conflict
with ISO C90 are disabled). Same as @option{-ansi} for C code.
@w{@uref{http://gcc.gnu.org/c99status.html}} for more information. The
names @samp{c9x} and @samp{iso9899:199x} are deprecated.
-@item gnu89
+@item gnu90
+@itemx gnu89
GNU dialect of ISO C90 (including some C99 features). This
is the default for C code.
The option @option{-fno-gnu89-inline} explicitly tells GCC to use the
C99 semantics for @code{inline} when in C99 or gnu99 mode (i.e., it
specifies the default behavior). This option was first supported in
-GCC 4.3. This option is not supported in C89 or gnu89 mode.
+GCC 4.3. This option is not supported in @option{-std=c90} or
+@option{-std=gnu90} mode.
The preprocessor macros @code{__GNUC_GNU_INLINE__} and
@code{__GNUC_STDC_INLINE__} may be used to check which semantics are
The default is version 2.
+Version 3 corrects an error in mangling a constant address as a
+template argument.
+
+Version 4 implements a standard mangling for vector types.
+
+See also @option{-Wabi}.
+
@item -fno-access-control
@opindex fno-access-control
Turn off all access checking. This switch is mainly useful for working
Emit statistics about front-end processing at the end of the compilation.
This information is generally only useful to the G++ development team.
-@item -ftemplate-depth-@var{n}
+@item -ftemplate-depth=@var{n}
@opindex ftemplate-depth
Set the maximum instantiation depth for template classes to @var{n}.
A limit on the template instantiation depth is needed to detect
concerned about the fact that code generated by G++ may not be binary
compatible with code generated by other compilers.
-The known incompatibilities at this point include:
+The known incompatibilities in @option{-fabi-version=2} (the default) include:
+
+@itemize @bullet
+
+@item
+A template with a non-type template parameter of reference type is
+mangled incorrectly:
+@smallexample
+extern int N;
+template <int &> struct S @{@};
+void n (S<N>) @{2@}
+@end smallexample
+
+This is fixed in @option{-fabi-version=3}.
+
+@item
+SIMD vector types declared using @code{__attribute ((vector_size))} are
+mangled in a non-standard way that does not allow for overloading of
+functions taking vectors of different sizes.
+
+The mangling is changed in @option{-fabi-version=4}.
+@end itemize
+
+The known incompatibilities in @option{-fabi-version=1} include:
@itemize @bullet
support such a feature in the near future.
Where the standard specified with @option{-std} represents a GNU
-extended dialect of C, such as @samp{gnu89} or @samp{gnu99}, there is a
+extended dialect of C, such as @samp{gnu90} or @samp{gnu99}, there is a
corresponding @dfn{base standard}, the version of ISO C on which the GNU
extended dialect is based. Warnings from @option{-pedantic} are given
where they are required by the base standard. (It would not make sense
-Wsign-compare @gol
-Wtype-limits @gol
-Wuninitialized @gol
--Wunused-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
+-Wunused-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
+-Wunused-but-set-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
}
The option @option{-Wextra} also prints warning messages for the
comment, or whenever a Backslash-Newline appears in a @samp{//} comment.
This warning is enabled by @option{-Wall}.
+@item -Wno-cpp \
+@r{(C, Objective-C, C++, Objective-C++ and Fortran only)}
+
+Suppress warning messages emitted by @code{#warning} directives.
+
@item -Wformat
@opindex Wformat
@opindex Wno-format
the program (trigraphs within comments are not warned about).
This warning is enabled by @option{-Wall}.
+@item -Wunused-but-set-parameter
+@opindex Wunused-but-set-parameter
+@opindex Wno-unused-but-set-parameter
+Warn whenever a function parameter is assigned to, but otherwise unused
+(aside from its declaration).
+
+To suppress this warning use the @samp{unused} attribute
+(@pxref{Variable Attributes}).
+
+This warning is also enabled by @option{-Wunused} together with
+@option{-Wextra}.
+
+@item -Wunused-but-set-variable
+@opindex Wunused-but-set-variable
+@opindex Wno-unused-but-set-variable
+Warn whenever a local variable is assigned to, but otherwise unused
+(aside from its declaration).
+This warning is enabled by @option{-Wall}.
+
+To suppress this warning use the @samp{unused} attribute
+(@pxref{Variable Attributes}).
+
+This warning is also enabled by @option{-Wunused}, which is enabled
+by @option{-Wall}.
+
@item -Wunused-function
@opindex Wunused-function
@opindex Wno-unused-function
Level 3 (default for @option{-Wstrict-aliasing}):
Should have very few false positives and few false
negatives. Slightly slower than levels 1 or 2 when optimization is enabled.
-Takes care of the common punn+dereference pattern in the frontend:
+Takes care of the common pun+dereference pattern in the frontend:
@code{*(int*)&some_float}.
If optimization is enabled, it also runs in the backend, where it deals
with multiple statement cases using flow-sensitive points-to information.
conversions between signed and unsigned integers can be disabled by
using @option{-Wno-sign-conversion}.
-For C++, also warn for conversions between @code{NULL} and non-pointer
-types; confusing overload resolution for user-defined conversions; and
-conversions that will never use a type conversion operator:
-conversions to @code{void}, the same type, a base class or a reference
-to them. Warnings about conversions between signed and unsigned
-integers are disabled by default in C++ unless
+For C++, also warn for confusing overload resolution for user-defined
+conversions; and conversions that will never use a type conversion
+operator: conversions to @code{void}, the same type, a base class or a
+reference to them. Warnings about conversions between signed and
+unsigned integers are disabled by default in C++ unless
@option{-Wsign-conversion} is explicitly enabled.
+@item -Wno-conversion-null @r{(C++ and Objective-C++ only)}
+@opindex Wconversion-null
+@opindex Wno-conversion-null
+Do not warn for conversions between @code{NULL} and non-pointer
+types. @option{-Wconversion-null} is enabled by default.
+
@item -Wempty-body
@opindex Wempty-body
@opindex Wno-empty-body
@opindex Wno-nested-externs
Warn if an @code{extern} declaration is encountered within a function.
-@item -Wunreachable-code
-@opindex Wunreachable-code
-@opindex Wno-unreachable-code
-Warn if the compiler detects that code will never be executed.
-
-This option is intended to warn when the compiler detects that at
-least a whole line of source code will never be executed, because
-some condition is never satisfied or because it is after a
-procedure that never returns.
-
-It is possible for this option to produce a warning even though there
-are circumstances under which part of the affected line can be executed,
-so care should be taken when removing apparently-unreachable code.
-
-For instance, when a function is inlined, a warning may mean that the
-line is unreachable in only one inlined copy of the function.
-
-This option is not made part of @option{-Wall} because in a debugging
-version of a program there is often substantial code which checks
-correct functioning of the program and is, hopefully, unreachable
-because the program does work. Another common use of unreachable
-code is to provide behavior which is selectable at compile-time.
-
@item -Winline
@opindex Winline
@opindex Wno-inline
using longer strings.
The limit applies @emph{after} string constant concatenation, and does
-not count the trailing NUL@. In C89, the limit was 509 characters; in
+not count the trailing NUL@. In C90, the limit was 509 characters; in
C99, it was raised to 4095. C++98 does not specify a normative
minimum maximum, so we do not diagnose overlength strings in C++@.
amount of debugging output the scheduler prints. This information is
written to standard error, unless @option{-fdump-rtl-sched1} or
@option{-fdump-rtl-sched2} is specified, in which case it is output
-to the usual dump listing file, @file{.sched} or @file{.sched2}
+to the usual dump listing file, @file{.sched1} or @file{.sched2}
respectively. However for @var{n} greater than nine, the output is
always printed to standard error.
Not all optimizations are controlled directly by a flag. Only
optimizations that have a flag are listed in this section.
-Most of the optimizations are not enabled if a @option{-O} level is not set on
-the command line, even if individual optimization flags are specified.
+Most optimizations are only enabled if an @option{-O} level is set on
+the command line. Otherwise they are disabled, even if individual
+optimization flags are specified.
Depending on the target and how GCC was configured, a slightly different
set of optimizations may be enabled at each @option{-O} level than
In C, emit @code{static} functions that are declared @code{inline}
into the object file, even if the function has been inlined into all
of its callers. This switch does not affect functions using the
-@code{extern inline} extension in GNU C89@. In C++, emit any and all
+@code{extern inline} extension in GNU C90@. In C++, emit any and all
inline functions into the object file.
@item -fkeep-static-consts
with @option{-fschedule-insns} or @option{-fschedule-insns2} or
at @option{-O2} or higher.
-@item -fsched2-use-traces
-@opindex fsched2-use-traces
-Use @option{-fsched2-use-superblocks} algorithm when scheduling after register
-allocation and additionally perform code duplication in order to increase the
-size of superblocks using tracer pass. See @option{-ftracer} for details on
-trace formation.
-
-This mode should produce faster but significantly longer programs. Also
-without @option{-fbranch-probabilities} the traces constructed may not
-match the reality and hurt the performance. This only makes
-sense when scheduling after register allocation, i.e.@: with
-@option{-fschedule-insns2} or at @option{-O2} or higher.
-
@item -freschedule-modulo-scheduled-loops
@opindex freschedule-modulo-scheduled-loops
The modulo scheduling comes before the traditional scheduling, if a loop
Perform loop strip mining transformations on loops. Strip mining
splits a loop into two nested loops. The outer loop has strides
equal to the strip size and the inner loop has strides of the
-original loop within a strip. For example, given a loop like:
+original loop within a strip. The strip length can be changed
+using the @option{loop-block-tile-size} parameter. For example,
+given a loop like:
@smallexample
DO I = 1, N
A(I) = A(I) + C
@end smallexample
loop strip mining will transform the loop as if the user had written:
@smallexample
-DO II = 1, N, 4
- DO I = II, min (II + 3, N)
+DO II = 1, N, 51
+ DO I = II, min (II + 50, N)
A(I) = A(I) + C
ENDDO
ENDDO
@item -floop-block
Perform loop blocking transformations on loops. Blocking strip mines
each loop in the loop nest such that the memory accesses of the
-element loops fit inside caches. For example, given a loop like:
+element loops fit inside caches. The strip length can be changed
+using the @option{loop-block-tile-size} parameter. For example, given
+a loop like:
@smallexample
DO I = 1, N
DO J = 1, M
@end smallexample
loop blocking will transform the loop as if the user had written:
@smallexample
-DO II = 1, N, 64
- DO JJ = 1, M, 64
- DO I = II, min (II + 63, N)
- DO J = JJ, min (JJ + 63, M)
+DO II = 1, N, 51
+ DO JJ = 1, M, 51
+ DO I = II, min (II + 50, N)
+ DO J = JJ, min (JJ + 50, M)
A(J, I) = B(I) + C(J)
ENDDO
ENDDO
was mixing languages before, all you need to add is @option{-flto} to
all the compile and link commands.
+If LTO encounters objects with C linkage declared with incompatible
+types in separate translation units to be linked together (undefined
+behavior according to ISO C99 6.2.7), a non-fatal diagnostic may be
+issued. The behavior is still undefined at runtime.
+
If object files containing GIMPLE bytecode are stored in a library
archive, say @file{libfoo.a}, it is possible to extract and use them
in an LTO link if you are using @command{gold} as the linker (which,
and thus may not be used when ordered comparisons are required.
This option requires that both @option{-fno-signed-zeros} and
@option{-fno-trapping-math} be in effect. Moreover, it doesn't make
-much sense with @option{-frounding-math}.
+much sense with @option{-frounding-math}. For Fortran the option
+is automatically enabled when both @option{-fno-signed-zeros} and
+@option{-fno-trapping-math} are in effect.
The default is @option{-fno-associative-math}.
parameter, then structure reorganization is not applied to this structure.
The default is 10.
-@item predictable-branch-cost-outcome
+@item predictable-branch-outcome
When branch is predicted to be taken with probability lower than this threshold
(in percent), then it is considered well predictable. The default is 10.
@item max-completely-peel-times
The maximum number of iterations of a loop to be suitable for complete peeling.
+@item max-completely-peel-loop-nest-depth
+The maximum depth of a loop nest suitable for complete peeling.
+
@item max-unswitch-insns
The maximum number of insns of an unswitched loop.
motion optimization performed on them. The default value of the
parameter is 1000 for -O1 and 10000 for -O2 and above.
+@item max-vartrack-size
+Sets a maximum number of hash table slots to use during variable
+tracking dataflow analysis of any function. If this limit is exceeded
+with variable tracking at assignments enabled, analysis for that
+function is retried without it, after removing all debug insns from
+the function. If the limit is exceeded even without debug insns, var
+tracking analysis is completely disabled for the function. Setting
+the parameter to zero makes it unlimited.
+
@item min-nondebug-insn-uid
Use uids starting at this parameter for nondebug insns. The range below
the parameter is reserved exclusively for debug insns created by
@option{ipa-sra-ptr-growth-factor} times the size of the original
pointer parameter.
+@item graphite-max-nb-scop-params
+To avoid exponential effects in the Graphite loop transforms, the
+number of parameters in a Static Control Part (SCoP) is bounded. The
+default value is 10 parameters. A variable whose value is unknown at
+compile time and defined outside a SCoP is a parameter of the SCoP.
+
+@item graphite-max-bbs-per-function
+To avoid exponential effects in the detection of SCoPs, the size of
+the functions analyzed by Graphite is bounded. The default value is
+100 basic blocks.
+
+@item loop-block-tile-size
+Loop blocking or strip mining transforms, enabled with
+@option{-floop-block} or @option{-floop-strip-mine}, strip mine each
+loop in the loop nest by a given number of iterations. The strip
+length can be changed using the @option{loop-block-tile-size}
+parameter. The default value is 51 iterations.
+
@end table
@end table
@item k6
AMD K6 CPU with MMX instruction set support.
@item k6-2, k6-3
-Improved versions of AMD K6 CPU with MMX and 3dNOW!@: instruction set support.
+Improved versions of AMD K6 CPU with MMX and 3DNow!@: instruction set support.
@item athlon, athlon-tbird
-AMD Athlon CPU with MMX, 3dNOW!, enhanced 3dNOW!@: and SSE prefetch instructions
+AMD Athlon CPU with MMX, 3dNOW!, enhanced 3DNow!@: and SSE prefetch instructions
support.
@item athlon-4, athlon-xp, athlon-mp
-Improved AMD Athlon CPU with MMX, 3dNOW!, enhanced 3dNOW!@: and full SSE
+Improved AMD Athlon CPU with MMX, 3DNow!, enhanced 3DNow!@: and full SSE
instruction set support.
@item k8, opteron, athlon64, athlon-fx
AMD K8 core based CPUs with x86-64 instruction set support. (This supersets
-MMX, SSE, SSE2, 3dNOW!, enhanced 3dNOW!@: and 64-bit instruction set extensions.)
+MMX, SSE, SSE2, 3DNow!, enhanced 3DNow!@: and 64-bit instruction set extensions.)
@item k8-sse3, opteron-sse3, athlon64-sse3
Improved versions of k8, opteron and athlon64 with SSE3 instruction set support.
@item amdfam10, barcelona
AMD Family 10h core based CPUs with x86-64 instruction set support. (This
-supersets MMX, SSE, SSE2, SSE3, SSE4A, 3dNOW!, enhanced 3dNOW!, ABM and 64-bit
+supersets MMX, SSE, SSE2, SSE3, SSE4A, 3DNow!, enhanced 3DNow!, ABM and 64-bit
instruction set extensions.)
@item winchip-c6
IDT Winchip C6 CPU, dealt in same way as i486 with additional MMX instruction
set support.
@item winchip2
-IDT Winchip2 CPU, dealt in same way as i486 with additional MMX and 3dNOW!@:
+IDT Winchip2 CPU, dealt in same way as i486 with additional MMX and 3DNow!@:
instruction set support.
@item c3
-Via C3 CPU with MMX and 3dNOW!@: instruction set support. (No scheduling is
+Via C3 CPU with MMX and 3DNow!@: instruction set support. (No scheduling is
implemented for this chip.)
@item c3-2
Via C3-2 CPU with MMX and SSE instruction set support. (No scheduling is
implemented for this chip.)
@item geode
-Embedded AMD CPU with MMX and 3dNOW! instruction set support.
+Embedded AMD CPU with MMX and 3DNow!@: instruction set support.
@end table
While picking a specific @var{cpu-type} will schedule things appropriately
@subsection RX Options
@cindex RX Options
-These @option{-m} options are defined for RX implementations:
+These command line options are defined for RX targets:
@table @gcctabopt
@item -m64bit-doubles
@itemx -m32bit-doubles
-@itemx -fpu
-@itemx -nofpu
@opindex m64bit-doubles
@opindex m32bit-doubles
-@opindex fpu
-@opindex nofpu
Make the @code{double} data type be 64-bits (@option{-m64bit-doubles})
or 32-bits (@option{-m32bit-doubles}) in size. The default is
-@option{-m64bit-doubles}. @emph{Note} the RX's hardware floating
-point instructions are only used for 32-bit floating point values, and
-then only if @option{-ffast-math} has been specified on the command
-line. This is because the RX FPU instructions do not properly support
-denormal (or sub-normal) values.
-
-The options @option{-fpu} and @option{-nofpu} have been provided at
-the request of Rensas for compatibility with their toolchain. The
-@option{-mfpu} option enables the use of RX FPU instructions by
-selecting 32-bit doubles and enabling unsafe math optimizations. The
-@option{-mnofpu} option disables the use of RX FPU instructions, even
-if @option{-m32bit-doubles} is active and unsafe math optimizations
-have been enabled.
+@option{-m32bit-doubles}. @emph{Note} RX floating point hardware only
+works on 32-bit values, which is why the default is
+@option{-m32bit-doubles}.
+
+@item -fpu
+@itemx -nofpu
+@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 instructions will only be generated for 32-bit floating
+point values however, so if the @option{-m64bit-doubles} option is in
+use then the FPU hardware will not be used for doubles.
+
+@emph{Note} If the @option{-fpu} option is enabled then
+@option{-funsafe-math-optimizations} is also enabled automatically.
+This is because the RX FPU instructions are themselves unsafe.
@item -mcpu=@var{name}
@itemx -patch=@var{name}
@opindex -mcpu
@opindex -patch
-Selects the type of RX CPU to be targeted. Currently on two types are
-supported, the generic @var{RX600} and the specific @var{RX610}. The
-only difference between them is that the @var{RX610} does not support
-the @code{MVTIPL} instruction.
+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}.
+
+The only difference between @var{RX600} and @var{RX610} is that the
+@var{RX610} does not support the @code{MVTIPL} instruction.
+
+The @var{RX200} series does not have a hardware floating point unit
+and so @option{-nofpu} is enabled by default when this type is
+selected.
@item -mbig-endian-data
@itemx -mlittle-endian-data
Note, common variables (variables which have not been initialised) and
constants are not placed into the small data area as they are assigned
-to other sections in the output executeable.
+to other sections in the output executable.
The default value is zero, which disables this feature. Note, this
feature is not enabled by default with higher optimization levels
-(@option{-O2} etc) because of the potentially deterimental effects of
+(@option{-O2} etc) because of the potentially detrimental effects of
reserving register @code{r13}. It is up to the programmer to
experiment and discover whether this feature is of benefit to their
program.
@item -mmax-constant-size=@var{N}
@opindex mmax-constant-size
-Specifies the maxium size, in bytes, of a constant that can be used as
+Specifies the maximum size, in bytes, of a constant that can be used as
an operand in a RX instruction. Although the RX instruction set does
-allow consants of up to 4 bytes in length to be used in instructions,
+allow constants of up to 4 bytes in length to be used in instructions,
a longer value equates to a longer instruction. Thus in some
circumstances it can be beneficial to restrict the size of constants
that are used in instructions. Constants that are too big are instead
placed into a constant pool and referenced via register indirection.
-The value @var{N} can be between 0 and 3. A value of 0, the default,
-means that constants of any size are allowed.
+The value @var{N} can be between 0 and 4. A value of 0 (the default)
+or 4 means that constants of any size are allowed.
@item -mrelax
@opindex mrelax
@opindex mint-register
Specify the number of registers to reserve for fast interrupt handler
functions. The value @var{N} can be between 0 and 4. A value of 1
-means that register @code{r13} will be reserved for ther exclusive use
+means that register @code{r13} will be reserved for the exclusive use
of fast interrupt handlers. A value of 2 reserves @code{r13} and
@code{r12}. A value of 3 reserves @code{r13}, @code{r12} and
@code{r11}, and a value of 4 reserves @code{r13} through @code{r10}.
@opindex municode
This option is available for mingw-w64 targets. It specifies
that the UNICODE macro is getting pre-defined and that the
-unicode capable runtime startup code is choosen.
+unicode capable runtime startup code is chosen.
@item -mwin32
@opindex mwin32
@option{-Wl,--defsym,__stack_limit=0x7ffe0000} to enforce a stack limit
of 128KB@. Note that this may only work with the GNU linker.
-@cindex aliasing of parameters
-@cindex parameters, aliased
-@item -fargument-alias
-@itemx -fargument-noalias
-@itemx -fargument-noalias-global
-@itemx -fargument-noalias-anything
-@opindex fargument-alias
-@opindex fargument-noalias
-@opindex fargument-noalias-global
-@opindex fargument-noalias-anything
-Specify the possible relationships among parameters and between
-parameters and global data.
-
-@option{-fargument-alias} specifies that arguments (parameters) may
-alias each other and may alias global storage.@*
-@option{-fargument-noalias} specifies that arguments do not alias
-each other, but may alias global storage.@*
-@option{-fargument-noalias-global} specifies that arguments do not
-alias each other and do not alias global storage.
-@option{-fargument-noalias-anything} specifies that arguments do not
-alias any other storage.
-
-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
@opindex fleading-underscore
This option and its counterpart, @option{-fno-leading-underscore}, forcibly