@item Overall Options
@xref{Overall Options,,Options Controlling the Kind of Output}.
@smallexample
--c -S -E -o @var{file} -pipe -pass-exit-codes -v --help -x @var{language}
+-c -S -E -o @var{file} -pipe -pass-exit-codes -v --target-help --help -x @var{language}
@end smallexample
@item C Language Options
-fdata-sections -ffunction-sections -fgcse
-finline-functions -finline-limit=@var{n} -fkeep-inline-functions
-fmove-all-movables -fno-default-inline -fno-defer-pop
--fno-function-cse -fno-inline -fno-peephole
+-fno-function-cse -fno-inline -fno-peephole -ftrapv
-fomit-frame-pointer -foptimize-register-moves -foptimize-sibling-calls
--fregmove -frerun-cse-after-loop -frerun-loop-opt -freduce-all-givs
--fschedule-insns -fschedule-insns2 -fssa -fstrength-reduce
--fstrict-aliasing -fthread-jumps -funroll-all-loops
+-fregmove -frename-registers -frerun-cse-after-loop -frerun-loop-opt
+-freduce-all-givs -fschedule-insns -fschedule-insns2 -fssa
+-fstrength-reduce -fstrict-aliasing -fthread-jumps -funroll-all-loops
-funroll-loops
-O -O0 -O1 -O2 -O3 -Os
@end smallexample
-mfix7000 -mno-crt0
@emph{i386 Options}
--mcpu=@var{cpu type}
--march=@var{cpu type}
--mieee-fp -mno-fancy-math-387
+-mcpu=@var{cpu type} -march=@var{cpu type}
+-mintel-syntax -mieee-fp -mno-fancy-math-387
-mno-fp-ret-in-387 -msoft-float -msvr3-shlib
-mno-wide-multiply -mrtd -malign-double
-mreg-alloc=@var{list} -mregparm=@var{num}
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.
+
+@item --target-help
+Print (on the standard output) a description of target specific command
+line options for each tool.
@end table
@node Invoking G++
a declaration. According to the C Standard, this usage is obsolescent.
@item
+The return type of a function has a type qualifier such as @code{const}.
+Such a type qualifier has no effect, since the value returned by a
+function is not an lvalue. (But don't warn about the GNU extension of
+@code{volatile void} return types. That extension will be warned about
+if @samp{-pedantic} is specified.)
+
+@item
If @samp{-Wall} or @samp{-Wunused} is also specified, warn about unused
arguments.
adding the @code{noreturn} attribute, otherwise subtle code generation
bugs could be introduced.
+@item -Wmissing-format-attribute
+If @samp{-Wformat} is enabled, also warn about functions which might be
+candidates for @code{format} attributes. Note these are only possible
+candidates, not absolute ones. GCC will guess that @code{format}
+attributes might be appropriate for any function that calls a function
+like @code{vprintf} or @code{vscanf}, but this might not always be the
+case, and some functions for which @code{format} attributes are
+appropriate may not be detected. This option has no effect unless
+@samp{-Wformat} is enabled (possibly by @samp{-Wall}).
+
@item -Wpacked
Warn if a structure is given the packed attribute, but the packed
attribute has no effect on the layout or size of the structure.
@item b
Dump after computing branch probabilities, to @file{@var{file}.11.bp}.
@item B
-Dump after block reordering, to @file{@var{file}.25.bbro}.
+Dump after block reordering, to @file{@var{file}.26.bbro}.
@item c
Dump after instruction combination, to the file @file{@var{file}.14.combine}.
@item C
Dump after the first if conversion, to the file @file{@var{file}.15.ce}.
@item d
-Dump after delayed branch scheduling, to @file{@var{file}.28.dbr}.
+Dump after delayed branch scheduling, to @file{@var{file}.29.dbr}.
@item D
Dump all macro definitions, at the end of preprocessing, in addition to
normal output.
Dump after SSA optimizations, to @file{@var{file}.05.ssa} and
@file{@var{file}.06.ussa}.
@item E
-Dump after the second if conversion, to @file{@var{file}.21.ce2}.
+Dump after the second if conversion, to @file{@var{file}.24.ce2}.
@item f
Dump after life analysis, to @file{@var{file}.13.life}.
@item F
Dump after purging @code{ADDRESSOF} codes, to @file{@var{file}.04.addressof}.
@item g
Dump after global register allocation, to @file{@var{file}.19.greg}.
+@item o
+Dump after post-reload CSE and other optimizations, to @file{@var{file}.20.postreload}.
@item G
Dump after GCSE, to @file{@var{file}.08.gcse}.
@item i
@item j
Dump after the first jump optimization, to @file{@var{file}.02.jump}.
@item J
-Dump after the last jump optimization, to @file{@var{file}.26.jump2}.
+Dump after the last jump optimization, to @file{@var{file}.27.jump2}.
@item k
Dump after conversion from registers to stack, to @file{@var{file}.29.stack}.
@item l
Dump after loop optimization, to @file{@var{file}.09.loop}.
@item M
Dump after performing the machine dependent reorganisation pass, to
-@file{@var{file}.27.mach}.
+@file{@var{file}.28.mach}.
@item n
Dump after register renumbering, to @file{@var{file}.23.rnreg}.
@item N
Dump after RTL generation, to @file{@var{file}.00.rtl}.
@item R
Dump after the second instruction scheduling pass, to
-@file{@var{file}.24.sched2}.
+@file{@var{file}.25.sched2}.
@item s
Dump after CSE (including the jump optimization that sometimes follows
CSE), to @file{@var{file}.03.cse}.
Dump after the second CSE pass (including the jump optimization that
sometimes follows CSE), to @file{@var{file}.10.cse2}.
@item w
-Dump after the second flow pass, to @file{@var{file}.20.flow2}.
+Dump after the second flow pass, to @file{@var{file}.21.flow2}.
@item X
Dump after dead code elimination, to @file{@var{file}.06.dce}.
@item z
As compared to @samp{-O}, this option increases both compilation time
and the performance of the generated code.
-@samp{-O2} turns on all optional optimizations except for loop unrolling
-and function inlining. It also turns on the @samp{-fforce-mem} option
-on all machines and frame pointer elimination on machines where doing so
-does not interfere with debugging.
+@samp{-O2} turns on all optional optimizations except for loop unrolling,
+function inlining, and register renaming. It also turns on the
+@samp{-fforce-mem} option on all machines and frame pointer elimination
+on machines where doing so does not interfere with debugging.
@item -O3
Optimize yet more. @samp{-O3} turns on all optimizations specified by
-@samp{-O2} and also turns on the @samp{inline-functions} option.
+@samp{-O2} and also turns on the @samp{-finline-functions} and
+@samp{-frename-registers} options.
@item -O0
Do not optimize.
@item -foptimize-sibling-calls
Optimize sibling and tail recursive calls.
+@item -ftrapv
+This option generates traps for signed overflow on addition, subtraction,
+multiplication operations.
+
@item -fno-inline
Don't pay attention to the @code{inline} keyword. Normally this option
is used to keep the compiler from expanding any functions inline.
-fno-delete-null-pointer-checks to disable this optimizing for programs
which depend on that behavior.
-
@item -fexpensive-optimizations
Perform a number of minor optimizations that are relatively expensive.
Treat floating point constant as single precision constant instead of
implicitly converting it to double precision constant.
+@item -frename-registers
+Attempt to avoid false dependancies in scheduled code by making use
+of registers left over after register allocation. This optimization
+will most benefit processors with lots of registers. It can, however,
+make debugging impossible, since variables will no longer stay in
+a ``home register''.
@end table
@node Preprocessor Options
executables (preprocessor, compiler per se, assembler and linker)
that do the real work. However, since no real work is done in the
driver program, it usually does not matter that the driver program
-in use is not the one for the specified target and version.
+in use is not the one for the specified target. It is common for the
+interface to the other executables to change incompatibly between
+compiler versions, so unless the version specified is very close to that
+of the driver (for example, @samp{-V 3.0} with a driver program from GCC
+version 3.0.1), use of @samp{-V} may not work; for example, using
+@samp{-V 2.95.2} will not work with a driver program from GCC 3.0.
The only way that the driver program depends on the target machine is
in the parsing and handling of special machine-specific options.
However, this is controlled by a file which is found, along with the
other executables, in the directory for the specified version and
target machine. As a result, a single installed driver program adapts
-to any specified target machine and compiler version.
+to any specified target machine, and sufficiently similar compiler
+versions.
The driver program executable does control one significant thing,
however: the default version and target machine. Therefore, you can
Synonyms for -mcpu=i386, -mcpu=i486, -mcpu=pentium, and -mcpu=pentiumpro
respectively. These synonyms are deprecated.
+@item -mintel-syntax
+Emit assembly using Intel syntax opcodes instead of AT&T syntax.
+
@item -mieee-fp
@itemx -mno-ieee-fp
Control whether or not the compiler uses IEEE floating point
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