@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-@c 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+@c 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@ignore
@c man begin COPYRIGHT
Copyright @copyright{} 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
-1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2 or
@c man end
@c man begin BUGS
For instructions on reporting bugs, see
-@w{@uref{http://gcc.gnu.org/bugs.html}}. Use of the @command{gccbug}
-script to report bugs is recommended.
+@w{@uref{http://gcc.gnu.org/bugs.html}}.
@c man end
@c man begin AUTHOR
See the Info entry for @command{gcc}, or
-w -Wextra -Wall -Waggregate-return @gol
-Wcast-align -Wcast-qual -Wchar-subscripts -Wcomment @gol
-Wconversion -Wno-deprecated-declarations @gol
--Wdisabled-optimization -Wno-div-by-zero -Wendif-labels @gol
+-Wdisabled-optimization -Wno-div-by-zero -Wno-endif-labels @gol
-Werror -Werror-implicit-function-declaration @gol
-Wfatal-errors -Wfloat-equal -Wformat -Wformat=2 @gol
-Wno-format-extra-args -Wformat-nonliteral @gol
@gccoptlist{-Wbad-function-cast -Wmissing-declarations @gol
-Wmissing-prototypes -Wnested-externs -Wold-style-definition @gol
-Wstrict-prototypes -Wtraditional @gol
--Wdeclaration-after-statement}
+-Wdeclaration-after-statement -Wno-pointer-sign}
@item Debugging Options
@xref{Debugging Options,,Options for Debugging Your Program or GCC}.
-fdump-tree-nrv -fdump-tree-vect @gol
-fdump-tree-sra@r{[}-@var{n}@r{]} @gol
-fdump-tree-fre@r{[}-@var{n}@r{]} @gol
+-ftree-vectorizer-verbose=@var{n} @gol
-feliminate-dwarf2-dups -feliminate-unused-debug-types @gol
-feliminate-unused-debug-symbols -fmem-report -fprofile-arcs -ftree-based-profiling @gol
-frandom-seed=@var{string} -fsched-verbose=@var{n} @gol
-floop-optimize -fcrossjumping -fif-conversion -fif-conversion2 @gol
-finline-functions -finline-limit=@var{n} -fkeep-inline-functions @gol
-fkeep-static-consts -fmerge-constants -fmerge-all-constants @gol
--fmodulo-sched -fnew-ra -fno-branch-count-reg @gol
+-fmodulo-sched -fno-branch-count-reg @gol
-fno-default-inline -fno-defer-pop -floop-optimize2 -fmove-loop-invariants @gol
-fno-function-cse -fno-guess-branch-probability @gol
-fno-inline -fno-math-errno -fno-peephole -fno-peephole2 @gol
-mvliw-branch -mno-vliw-branch @gol
-mmulti-cond-exec -mno-multi-cond-exec -mnested-cond-exec @gol
-mno-nested-cond-exec -mtomcat-stats @gol
+-mTLS -mtls @gol
-mcpu=@var{cpu}}
@emph{H8/300 Options}
@emph{IA-64 Options}
@gccoptlist{-mbig-endian -mlittle-endian -mgnu-as -mgnu-ld -mno-pic @gol
--mvolatile-asm-stop -mb-step -mregister-names -mno-sdata @gol
+-mvolatile-asm-stop -mregister-names -mno-sdata @gol
-mconstant-gp -mauto-pic -minline-float-divide-min-latency @gol
-minline-float-divide-max-throughput @gol
-minline-int-divide-min-latency @gol
--minline-int-divide-max-throughput -mno-dwarf2-asm @gol
--mfixed-range=@var{register-range}}
+-minline-int-divide-max-throughput @gol
+-minline-sqrt-min-latency -minline-sqrt-max-throughput @gol
+-mno-dwarf2-asm -mearly-stop-bits @gol
+-mfixed-range=@var{register-range} -mtls-size=@var{tls-size} @gol
+-mtune=@var{cpu-type} -mt -pthread -milp32 -mlp64}
@emph{M32R/D Options}
@gccoptlist{-m32r2 -m32rx -m32r @gol
-mpowerpc-gfxopt -mno-powerpc-gfxopt @gol
-mnew-mnemonics -mold-mnemonics @gol
-mfull-toc -mminimal-toc -mno-fp-in-toc -mno-sum-in-toc @gol
--m64 -m32 -mxl-call -mno-xl-call -mpe @gol
+-m64 -m32 -mxl-compat -mno-xl-compat -mpe @gol
-malign-power -malign-natural @gol
-msoft-float -mhard-float -mmultiple -mno-multiple @gol
-mstring -mno-string -mupdate -mno-update @gol
@emph{S/390 and zSeries Options}
@gccoptlist{-mtune=@var{cpu-type} -march=@var{cpu-type} @gol
--mhard-float -msoft-float -mbackchain -mno-backchain -mkernel-backchain @gol
+-mhard-float -msoft-float -mbackchain -mno-backchain @gol
+-mpacked-stack -mno-packed-stack @gol
-msmall-exec -mno-small-exec -mmvcle -mno-mvcle @gol
-m64 -m31 -mdebug -mno-debug -mesa -mzarch @gol
-mtpf-trace -mno-tpf-trace -mfused-madd -mno-fused-madd @gol
@item --version
@opindex version
-Display the version number and copyrights of the invoked GCC.
+Display the version number and copyrights of the invoked GCC@.
@end table
@node Invoking G++
@opindex no-integrated-cpp
Performs a compilation in two passes: preprocessing and compiling. This
option allows a user supplied "cc1", "cc1plus", or "cc1obj" via the
-@option{-B} option. The user supplied compilation step can then add in
+@option{-B} option. The user supplied compilation step can then add in
an additional preprocessing step after normal preprocessing but before
-compiling. The default is to use the integrated cpp (internal cpp)
+compiling. The default is to use the integrated cpp (internal cpp)
The semantics of this option will change if "cc1", "cc1plus", and
"cc1obj" are merged.
@item -fabi-version=@var{n}
@opindex fabi-version
-Use version @var{n} of the C++ ABI. Version 2 is the version of the
+Use version @var{n} of the C++ ABI@. Version 2 is the version of the
C++ ABI that first appeared in G++ 3.4. Version 1 is the version of
the C++ ABI that first appeared in G++ 3.2. Version 0 will always be
the version that conforms most closely to the C++ ABI specification.
Causes all inlined methods to be marked with
@code{__attribute__ ((visibility ("hidden")))} so that they do not
appear in the export table of a DSO and do not require a PLT indirection
-when used within the DSO. Enabling this option can have a dramatic effect
+when used within the DSO@. Enabling this option can have a dramatic effect
on load and link times of a DSO as it massively reduces the size of the
-dynamic export table when the library makes heavy use of templates. While
+dynamic export table when the library makes heavy use of templates. While
it can cause bloating through duplication of code within each DSO where
it is used, often the wastage is less than the considerable space occupied
by a long symbol name in the export table which is typical when using
-templates and namespaces. For even more savings, combine with the
+templates and namespaces. For even more savings, combine with the
@option{-fvisibility=hidden} switch.
@item -fno-weak
@item -Wabi @r{(C++ only)}
@opindex Wabi
Warn when G++ generates code that is probably not compatible with the
-vendor-neutral C++ ABI. Although an effort has been made to warn about
+vendor-neutral C++ ABI@. Although an effort has been made to warn about
all such cases, there are probably some cases that are not warned about,
even though G++ is generating incompatible code. There may also be
cases where warnings are emitted even though the code that is generated
Warn if an array subscript has type @code{char}. This is a common cause
of error, as programmers often forget that this type is signed on some
machines.
+This warning is enabled by @option{-Wall}.
@item -Wcomment
@opindex Wcomment
Warn whenever a comment-start sequence @samp{/*} appears in a @samp{/*}
comment, or whenever a Backslash-Newline appears in a @samp{//} comment.
+This warning is enabled by @option{-Wall}.
@item -Wfatal-errors
@opindex Wfatal-errors
@item -Wimplicit-int
@opindex Wimplicit-int
Warn when a declaration does not specify a type.
+This warning is enabled by @option{-Wall}.
@item -Wimplicit-function-declaration
@itemx -Werror-implicit-function-declaration
Give a warning (or error) whenever a function is used before being
declared. The form @option{-Wno-error-implicit-function-declaration}
is not supported.
+This warning is enabled by @option{-Wall} (as a warning, not an error).
@item -Wimplicit
@opindex Wimplicit
Same as @option{-Wimplicit-int} and @option{-Wimplicit-function-declaration}.
+This warning is enabled by @option{-Wall}.
@item -Wmain
@opindex Wmain
Warn if the type of @samp{main} is suspicious. @samp{main} should be a
function with external linkage, returning int, taking either zero
arguments, two, or three arguments of appropriate types.
+This warning is enabled by @option{-Wall}.
@item -Wmissing-braces
@opindex Wmissing-braces
int b[2][2] = @{ @{ 0, 1 @}, @{ 2, 3 @} @};
@end smallexample
+This warning is enabled by @option{-Wall}.
+
@item -Wmissing-include-dirs @r{(C, C++, Objective-C and Objective-C++ only)}
@opindex Wmissing-include-dirs
Warn if a user-supplied include directory does not exist.
@end group
@end smallexample
+This warning is enabled by @option{-Wall}.
+
@item -Wsequence-point
@opindex Wsequence-point
Warn about code that may have undefined semantics because of violations
definitions, may be found on the GCC readings page, at
@w{@uref{http://gcc.gnu.org/readings.html}}.
+This warning is enabled by @option{-Wall}.
+
@item -Wreturn-type
@opindex Wreturn-type
Warn whenever a function is defined with a return-type that defaults to
message, even when @option{-Wno-return-type} is specified. The only
exceptions are @samp{main} and functions defined in system headers.
+This warning is enabled by @option{-Wall}.
+
@item -Wswitch
@opindex Wswitch
Warn whenever a @code{switch} statement has an index of enumerated type
enumeration. (The presence of a @code{default} label prevents this
warning.) @code{case} labels outside the enumeration range also
provoke warnings when this option is used.
+This warning is enabled by @option{-Wall}.
@item -Wswitch-default
@opindex Wswitch-switch
@opindex Wtrigraphs
Warn if any trigraphs are encountered that might change the meaning of
the program (trigraphs within comments are not warned about).
+This warning is enabled by @option{-Wall}.
@item -Wunused-function
@opindex Wunused-function
Warn whenever a static function is declared but not defined or a
non\-inline static function is unused.
+This warning is enabled by @option{-Wall}.
@item -Wunused-label
@opindex Wunused-label
Warn whenever a label is declared but not used.
+This warning is enabled by @option{-Wall}.
To suppress this warning use the @samp{unused} attribute
(@pxref{Variable Attributes}).
@opindex Wunused-variable
Warn whenever a local variable or non-constant static variable is unused
aside from its declaration
+This warning is enabled by @option{-Wall}.
To suppress this warning use the @samp{unused} attribute
(@pxref{Variable Attributes}).
@item -Wunused-value
@opindex Wunused-value
Warn whenever a statement computes a result that is explicitly not used.
+This warning is enabled by @option{-Wall}.
To suppress this warning cast the expression to @samp{void}.
you use that never return as @code{noreturn}. @xref{Function
Attributes}.
+This warning is enabled by @option{-Wall}.
+
@item -Wunknown-pragmas
@opindex Wunknown-pragmas
@cindex warning for unknown pragmas
@opindex Wstrict-aliasing
This option is only active when @option{-fstrict-aliasing} is active.
It warns about code which might break the strict aliasing rules that the
-compiler is using for optimization. The warning does not catch all
-cases, but does attempt to catch the more common pitfalls. It is
+compiler is using for optimization. The warning does not catch all
+cases, but does attempt to catch the more common pitfalls. It is
included in @option{-Wall}.
@item -Wstrict-aliasing=2
@opindex Wundef
Warn if an undefined identifier is evaluated in an @samp{#if} directive.
-@item -Wendif-labels
+@item -Wno-endif-labels
+@opindex Wno-endif-labels
@opindex Wendif-labels
-Warn whenever an @samp{#else} or an @samp{#endif} are followed by text.
+Do not warn whenever an @samp{#else} or an @samp{#endif} are followed by text.
@item -Wshadow
@opindex Wshadow
complex; GCC will refuse to optimize programs when the optimization
itself is likely to take inordinate amounts of time.
+@item -Wno-pointer-sign
+@opindex Wno-pointer-sign
+Don't warn for pointer argument passing or assignment with different signedness.
+Only useful in the negative form since this warning is enabled by default.
+This option is only supported for C and Objective-C@.
+
@item -Werror
@opindex Werror
Make all warnings into errors.
execution the program records how many times each branch and call is
executed and how many times it is taken or returns. When the compiled
program exits it saves this data to a file called
-@file{@var{auxname}.gcda} for each source file. The data may be used for
+@file{@var{auxname}.gcda} for each source file. The data may be used for
profile-directed optimizations (@option{-fbranch-probabilities}), or for
-test coverage analysis (@option{-ftest-coverage}). Each object file's
+test coverage analysis (@option{-ftest-coverage}). Each object file's
@var{auxname} is generated from the name of the output file, if
explicitly specified and it is not the final executable, otherwise it is
-the basename of the source file. In both cases any suffix is removed
+the basename of the source file. In both cases any suffix is removed
(e.g.@: @file{foo.gcda} for input file @file{dir/foo.c}, or
@file{dir/foo.gcda} for output file specified as @option{-o dir/foo.o}).
@item
Compile the source files with @option{-fprofile-arcs} plus optimization
-and code generation options. For test coverage analysis, use the
-additional @option{-ftest-coverage} option. You do not need to profile
+and code generation options. For test coverage analysis, use the
+additional @option{-ftest-coverage} option. You do not need to profile
every source file in a program.
@item
@item
Run the program on a representative workload to generate the arc profile
-information. This may be repeated any number of times. You can run
+information. This may be repeated any number of times. You can run
concurrent instances of your program, and provided that the file system
-supports locking, the data files will be correctly updated. Also
+supports locking, the data files will be correctly updated. Also
@code{fork} calls are detected and correctly handled (double counting
will not happen).
@item
For test coverage analysis, use @command{gcov} to produce human readable
-information from the @file{.gcno} and @file{.gcda} files. Refer to the
+information from the @file{.gcno} and @file{.gcda} files. Refer to the
@command{gcov} documentation for further information.
@end itemize
@opindex ftest-coverage
Produce a notes file that the @command{gcov} code-coverage utility
(@pxref{Gcov,, @command{gcov}---a Test Coverage Program}) can use to
-show program coverage. Each source file's note file is called
-@file{@var{auxname}.gcno}. Refer to the @option{-fprofile-arcs} option
+show program coverage. Each source file's note file is called
+@file{@var{auxname}.gcno}. Refer to the @option{-fprofile-arcs} option
above for a description of @var{auxname} and instructions on how to
-generate test coverage data. Coverage data will match the source files
+generate test coverage data. Coverage data will match the source files
more closely, if you do not optimize.
@item -d@var{letters}
@opindex fdump-ipa
Control the dumping at various stages of inter-procedural analysis
language tree to a file. The file name is generated by appending a switch
-specific suffix to the source file name. The following dumps are possible:
+specific suffix to the source file name. The following dumps are possible:
@table @samp
@item all
language tree to a file. The file name is generated by appending a switch
specific suffix to the source file name. If the @samp{-@var{options}}
form is used, @var{options} is a list of @samp{-} separated options that
-control the details of the dump. Not all options are applicable to all
-dumps, those which are not meaningful will be ignored. The following
+control the details of the dump. Not all options are applicable to all
+dumps, those which are not meaningful will be ignored. The following
options are available
@table @samp
@item address
Print the address of each node. Usually this is not meaningful as it
-changes according to the environment and source file. Its primary use
+changes according to the environment and source file. Its primary use
is for tying up a dump file with a debug environment.
@item slim
Inhibit dumping of members of a scope or body of a function merely
Dump the control flow graph of each function to a file in VCG format. The
file name is made by appending @file{.vcg} to the source file name. Note
that if the file contains more than one function, the generated file cannot
-be used directly by VCG. You will need to cut and paste each function's
+be used directly by VCG@. You will need to cut and paste each function's
graph into its own separate file first.
@item ch
@item ccp
@opindex fdump-tree-ccp
-Dump each function after CCP. The file name is made by appending
+Dump each function after CCP@. The file name is made by appending
@file{.ccp} to the source file name.
@item pre
Enable all the available tree dumps with the flags provided in this option.
@end table
+@item -ftree-vectorizer-verbose=@var{n}
+@opindex ftree-vectorizer-verbose
+This option controls the amount of debugging output the vectorizer prints.
+This information is written to standard error, unless @option{-fdump-tree-all}
+or @option{-fdump-tree-vect} is specified, in which case it is output to the
+usual dump listing file, @file{.vect}.
+
@item -frandom-seed=@var{string}
@opindex frandom-string
This option provides a seed that GCC uses when it would otherwise use
random numbers. It is used to generate certain symbol names
-that have to be different in every compiled file. It is also used to
+that have to be different in every compiled file. It is also used to
place unique stamps in coverage data files and the object files that
-produce them. You can use the @option{-frandom-seed} option to produce
+produce them. You can use the @option{-frandom-seed} option to produce
reproducibly identical object files.
The @var{string} should be different for every file you compile.
preprocessed @file{foo.i} output file even though the compiler now
normally uses an integrated preprocessor.
+When used in combination with the @option{-x} command line option,
+@option{-save-temps} is sensible enough to avoid over writing an
+input source file with the same extension as an intermediate file.
+The corresponding intermediate file may be obtained by renaming the
+source file before using @option{-save-temps}.
+
@item -time
@opindex time
Report the CPU time taken by each subprocess in the compilation
@item -fvar-tracking
@opindex fvar-tracking
-Run variable tracking pass. It computes where variables are stored at each
-position in code. Better debugging information is then generated
+Run variable tracking pass. It computes where variables are stored at each
+position in code. Better debugging information is then generated
(if the debugging information format supports this information).
It is enabled by default when compiling with optimization (@option{-Os},
@option{-O} turns on the following optimization flags:
@gccoptlist{-fdefer-pop @gol
--fmerge-constants @gol
--fthread-jumps @gol
+-fdelayed-branch @gol
+-fguess-branch-probability @gol
+-fcprop-registers @gol
-floop-optimize @gol
-fif-conversion @gol
-fif-conversion2 @gol
--fdelayed-branch @gol
--fguess-branch-probability @gol
--fcprop-registers}
+-ftree-ccp @gol
+-ftree-dce @gol
+-ftree-dom @gol
+-ftree-dse @gol
+-ftree-ter @gol
+-ftree-live_range_split @gol
+-ftree-sra @gol
+-ftree-copyrename @gol
+-ftree-fre @gol
+-ftree-ch @gol
+-fmerge-constants}
@option{-O} also turns on @option{-fomit-frame-pointer} on machines
where doing so does not interfere with debugging.
@option{-O2} turns on all optimization flags specified by @option{-O}. It
also turns on the following optimization flags:
-@gccoptlist{-fforce-mem @gol
+@gccoptlist{-fthread-jumps @gol
+-fcrossjumping @gol
-foptimize-sibling-calls @gol
--fstrength-reduce @gol
-fcse-follow-jumps -fcse-skip-blocks @gol
--frerun-cse-after-loop -frerun-loop-opt @gol
--fgcse -fgcse-lm -fgcse-sm -fgcse-las @gol
--fdelete-null-pointer-checks @gol
+-fgcse -fgcse-lm @gol
-fexpensive-optimizations @gol
--fregmove @gol
--fschedule-insns -fschedule-insns2 @gol
--fsched-interblock -fsched-spec @gol
+-fstrength-reduce @gol
+-frerun-cse-after-loop -frerun-loop-opt @gol
-fcaller-saves @gol
+-fforce-mem @gol
-fpeephole2 @gol
--freorder-blocks -freorder-functions @gol
+-fschedule-insns -fschedule-insns2 @gol
+-fsched-interblock -fsched-spec @gol
+-fregmove @gol
-fstrict-aliasing @gol
+-fdelete-null-pointer-checks @gol
+-freorder-blocks -freorder-functions @gol
-funit-at-a-time @gol
-falign-functions -falign-jumps @gol
-falign-loops -falign-labels @gol
--fcrossjumping}
+-ftree-pre}
Please note the warning under @option{-fgcse} about
invoking @option{-O2} on programs that use computed gotos.
@opindex O3
Optimize yet more. @option{-O3} turns on all optimizations specified by
@option{-O2} and also turns on the @option{-finline-functions},
-@option{-fweb} and @option{-fgcse-after-reload} options.
+@option{-funswitch-loops} and @option{-fgcse-after-reload} options.
@item -O0
@opindex O0
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 C. In C++, emit any and all
+@code{extern inline} extension in GNU C@. In C++, emit any and all
inline functions into the object file.
@item -fkeep-static-consts
pass. This pass looks at innermost loops and reorders their
instructions by overlapping different iterations.
-@item -fnew-ra
-@opindex fnew-ra
-Use a graph coloring register allocator. Currently this option is meant
-only for testing. Users should not specify this option, since it is not
-yet ready for production use.
-
@item -fno-branch-count-reg
@opindex fno-branch-count-reg
Do not use ``decrement and branch'' instructions on a count register,
second branch or a point immediately following it, depending on whether
the condition is known to be true or false.
-Enabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
+Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
@item -fcse-follow-jumps
@opindex fcse-follow-jumps
loops containing a load/store sequence can be changed to a load before
the loop and a store after the loop.
-Enabled by default when gcse is enabled.
+Not enabled at any optimization level.
@item -fgcse-las
@opindex fgcse-las
elimination pass eliminates redundant loads that come after stores to the
same memory location (both partial and full redundancies).
-Enabled by default when gcse is enabled.
+Not enabled at any optimization level.
@item -fgcse-after-reload
@opindex fgcse-after-reload
When @option{-fgcse-after-reload} is enabled, a redundant load elimination
-pass is performed after reload. The purpose of this pass is to cleanup
+pass is performed after reload. The purpose of this pass is to cleanup
redundant spilling.
@item -floop-optimize
@item -fcrossjumping
@opindex crossjumping
-Perform cross-jumping transformation. This transformation unifies equivalent code and save code size. The
+Perform cross-jumping transformation. This transformation unifies equivalent code and save code size. The
resulting code may or may not perform better than without cross-jumping.
Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
@item -ftree-pre
Perform Partial Redundancy Elimination (PRE) on trees. This flag is
-enabled by default at @option{-O} and higher.
+enabled by default at @option{-O2} and @option{-O3}.
@item -ftree-fre
Perform Full Redundancy Elimination (FRE) on trees. The difference
at @option{-O} and higher.
@item -ftree-loop-linear
-Perform linear loop transformations on tree. This flag can improve cache
+Perform linear loop transformations on tree. This flag can improve cache
performance and allow further loop optimizations to take place.
@item -ftree-lim
@item -ftracer
@opindex ftracer
-Perform tail duplication to enlarge superblock size. This transformation
+Perform tail duplication to enlarge superblock size. This transformation
simplifies the control flow of the function allowing other optimizations to do
better job.
(for best results, @option{-fweb} should be used as well).
Combination of @option{-fweb} and CSE is often sufficient to obtain the
-same effect. However in cases the loop body is more complicated than
+same effect. However in cases the loop body is more complicated than
a single basic block, this is not reliable. It also does not work at all
on some of the architectures due to restrictions in the CSE pass.
@item -fno-guess-branch-probability
@opindex fno-guess-branch-probability
-Do not guess branch probabilities using a randomized model.
-
-Sometimes GCC will opt to use a randomized model to guess branch
-probabilities, when none are available from either profiling feedback
-(@option{-fprofile-arcs}) or @samp{__builtin_expect}. This means that
-different runs of the compiler on the same program may produce different
-object code.
-
-In a hard real-time system, people don't want different runs of the
-compiler to produce code that has different behavior; minimizing
-non-determinism is of paramount import. This switch allows users to
-reduce non-determinism, possibly at the expense of inferior
-optimization.
+Do not guess branch probabilities using heuristics.
+
+GCC will use heuristics to guess branch probabilities if they are
+not provided by profiling feedback (@option{-fprofile-arcs}). These
+heuristics are based on the control flow graph. If some branch probabilities
+are specified by @samp{__builtin_expect}, then the heuristics will be
+used to guess branch probabilities for the rest of the control flow graph,
+taking the @samp{__builtin_expect} info into account. The interactions
+between the heuristics and @samp{__builtin_expect} can be complex, and in
+some cases, it may be useful to disable the heuristics so that the effects
+of @samp{__builtin_expect} are easier to understand.
The default is @option{-fguess-branch-probability} at levels
@option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
@item -freorder-functions
@opindex freorder-functions
-Reorder basic blocks in the compiled function in order to reduce number of
-taken branches and improve code locality. This is implemented by using special
+Reorder functions in the object file in order to
+improve code locality. This is implemented by using special
subsections @code{.text.hot} for most frequently executed functions and
@code{.text.unlikely} for unlikely executed functions. Reordering is done by
the linker so object file format must support named sections and linker must
@item
Static functions now can use non-standard passing conventions that
-may break @code{asm} statements calling functions directly. Again,
+may break @code{asm} statements calling functions directly. Again,
attribute @code{used} will prevent this behavior.
@end itemize
As a temporary workaround, @option{-fno-unit-at-a-time} can be used,
-but this scheme may not be supported by future releases of GCC.
+but this scheme may not be supported by future releases of GCC@.
Enabled at levels @option{-O2}, @option{-O3}.
Not enabled by default at any level because it has known bugs.
-@item -fnew-ra
-@opindex fnew-ra
-Use a graph coloring register allocator. Currently this option is meant
-for testing, so we are interested to hear about miscompilations with
-@option{-fnew-ra}.
-
@item -ftracer
@opindex ftracer
-Perform tail duplication to enlarge superblock size. This transformation
+Perform tail duplication to enlarge superblock size. This transformation
simplifies the control flow of the function allowing other optimizations to do
better job.
value is ignored in the case where all instructions in the block being
crossjumped from are matched. The default value is 5.
+@item max-goto-duplication-insns
+The maximum number of instructions to duplicate to a block that jumps
+to a computed goto. To avoid @math{O(N^2)} behavior in a number of
+passes, GCC factors computed gotos early in the compilation process,
+and unfactors them as late as possible. Only computed jumps at the
+end of a basic blocks with no more than max-goto-duplication-insns are
+unfactored. The default value is 8.
+
@item max-delay-slot-insn-search
The maximum number of instructions to consider when looking for an
instruction to fill a delay slot. If more than this arbitrary number of
The default value is 120.
@item large-function-insns
-The limit specifying really large functions. For functions greater than this
-limit inlining is constrained by @option{--param large-function-growth}.
-This parameter is useful primarily to avoid extreme compilation time caused by non-linear
-algorithms used by the backend.
+The limit specifying really large functions. For functions larger than this
+limit after inlining inlining is constrained by
+@option{--param large-function-growth}. This parameter is useful primarily
+to avoid extreme compilation time caused by non-linear algorithms used by the
+backend.
This parameter is ignored when @option{-funit-at-a-time} is not used.
The default value is 3000.
@item large-function-growth
Specifies maximal growth of large function caused by inlining in percents.
This parameter is ignored when @option{-funit-at-a-time} is not used.
-The default value is 200.
+The default value is 100 which limits large function growth to 2.0 times
+the original size.
@item inline-unit-growth
Specifies maximal overall growth of the compilation unit caused by inlining.
This parameter is ignored when @option{-funit-at-a-time} is not used.
-The default value is 150.
+The default value is 50 which limits unit growth to 1.5 times the original
+size.
@item max-inline-insns-recursive
@itemx max-inline-insns-recursive-auto
enabled and @option{--param max-inline-recursive-depth-auto} is used. The
default value is 500.
-@item max-inline-insns-rtl
-For languages that use the RTL inliner (this happens at a later stage
-than tree inlining), you can set the maximum allowable size (counted
-in RTL instructions) for the RTL inliner with this parameter.
-The default value is 600.
-
@item max-unrolled-insns
The maximum number of instructions that a loop should have if that loop
is unrolled, and if the loop is unrolled, it determines how many times
The induction variable optimizations give up on loops that contain more
induction variable uses.
+@item iv-always-prune-cand-set-bound
+If number of candidates in the set is smaller than this value,
+we always try to remove unnecessary ivs from the set during its
+optimization when a new iv is added to the set.
+
@item max-iterations-to-track
The maximum number of iterations of a loop the brute force algorithm
@item global-var-threshold
-Counts the number of function calls (N) and the number of
-call-clobbered variables (V). If NxV is larger than this limit, a
+Counts the number of function calls (@var{n}) and the number of
+call-clobbered variables (@var{v}). If @var{n}x@var{v} is larger than this limit, a
single artificial variable will be created to represent all the
call-clobbered variables at function call sites. This artificial
variable will then be made to alias every call-clobbered variable.
-(done as int * size_t on the host machine; beware overflow).
+(done as @code{int * size_t} on the host machine; beware overflow).
@item max-aliased-vops
generation.
The default is 30% + 70% * (RAM/1GB) with an upper bound of 100% when
-RAM >= 1GB. If @code{getrlimit} is available, the notion of "RAM" is
-the smallest of actual RAM and RLIMIT_DATA or RLIMIT_AS. If
+RAM >= 1GB@. If @code{getrlimit} is available, the notion of "RAM" is
+the smallest of actual RAM and @code{RLIMIT_DATA} or @code{RLIMIT_AS}. If
GCC is not able to calculate RAM on a particular platform, the lower
bound of 30% is used. Setting this parameter and
@option{ggc-min-heapsize} to zero causes a full collection to occur at
The maximum number of insns in a region to be considered for
interblock scheduling. The default value is 100.
+@item max-last-value-rtl
+
+The maximum size measured as number of RTLs that can be recorded in an expression
+in combiner for a pseudo register as last known value of that register. The default
+is 10000.
+
@item integer-share-limit
Small integer constants can use a shared data structure, reducing the
compiler's memory usage and increasing its speed. This sets the maximum
contain startup files. If the target supports multilibs then the
current multilib directory will be prepended to each of these paths.
-@item %M
-Output the multilib directory with directory separators replaced with
-@samp{_}. If multilib directories are not set, or the multilib directory is
-@file{.} then this option emits nothing.
-
@item %L
Process the @code{lib} spec. This is a spec string for deciding which
libraries should be included on the command line to the linker.
@table @gcctabopt
@item -mabi=@var{name}
@opindex mabi
-Generate code for the specified ABI. Permissible values are: @samp{apcs-gnu},
+Generate code for the specified ABI@. Permissible values are: @samp{apcs-gnu},
@samp{atpcs}, @samp{aapcs} and @samp{iwmmxt}.
@item -mapcs-frame
@item -mint8
@opindex mint8
-Assume int to be 8 bit integer. This affects the sizes of all types: A
+Assume int to be 8 bit integer. This affects the sizes of all types: A
char will be 1 byte, an int will be 1 byte, an long will be 2 bytes
-and long long will be 4 bytes. Please note that this option does not
+and long long will be 4 bytes. Please note that this option does not
comply to the C standards, but it will provide you with smaller code
size.
@end table
@opindex mcpu
Generate code for the specified architecture. The choices for
@var{architecture-type} are @samp{v3}, @samp{v8} and @samp{v10} for
-respectively ETRAX@w{ }4, ETRAX@w{ }100, and ETRAX@w{ }100@w{ }LX.
+respectively ETRAX@w{ }4, ETRAX@w{ }100, and ETRAX@w{ }100@w{ }LX@.
Default is @samp{v0} except for cris-axis-linux-gnu, where the default is
@samp{v10}.
With @option{-fpic} and @option{-fPIC}, don't generate (do generate)
instruction sequences that load addresses for functions from the PLT part
of the GOT rather than (traditional on other architectures) calls to the
-PLT. The default is @option{-mgotplt}.
+PLT@. The default is @option{-mgotplt}.
@item -maout
@opindex maout
@item -gused
@opindex -gused
-Emit debugging information for symbols that are used. For STABS
+Emit debugging information for symbols that are used. For STABS
debugging format, this enables @option{-feliminate-unused-debug-symbols}.
-This is by default ON.
+This is by default ON@.
@item -gfull
@opindex -gfull
@item -bundle_loader @var{executable}
@opindex bundle_loader
This option specifies the @var{executable} that will be loading the build
-output file being linked. See man ld(1) for more information.
+output file being linked. See man ld(1) for more information.
@item -dynamiclib
@opindex -dynamiclib
directly accessed via a single instruction.
The default is @option{-mlarge-data}. With this option the data area
-is limited to just below 2GB. Programs that require more than 2GB of
+is limited to just below 2GB@. Programs that require more than 2GB of
data must use @code{malloc} or @code{mmap} to allocate the data in the
heap instead of in the program's data segment.
optimization option such as @option{-O3} or above is present in the
command line.
+@item -mTLS
+@opindex TLS
+
+Assume a large TLS segment when generating thread-local code.
+
+@item -mtls
+@opindex tls
+
+Do not assume a large TLS segment when generating thread-local code.
+
@item -mgprel-ro
@opindex mgprel-ro
@item -msio
@opindex msio
-Generate the predefine, @code{_SIO}, for server IO. The default is
+Generate the predefine, @code{_SIO}, for server IO@. The default is
@option{-mwsio}. This generates the predefines, @code{__hp9000s700},
-@code{__hp9000s700__} and @code{_WSIO}, for workstation IO. These
-options are available under HP-UX and HI-UX.
+@code{__hp9000s700__} and @code{_WSIO}, for workstation IO@. These
+options are available under HP-UX and HI-UX@.
@item -mgnu-ld
@opindex gnu-ld
@item -threads
@opindex threads
Add support for multithreading with the @dfn{dce thread} library
-under HP-UX. This option sets flags for both the preprocessor and
+under HP-UX@. This option sets flags for both the preprocessor and
linker.
@end table
@var{cpu-type} are:
@table @emph
@item i386
-Original Intel's i386 CPU.
+Original Intel's i386 CPU@.
@item i486
-Intel's i486 CPU. (No scheduling is implemented for this chip.)
+Intel's i486 CPU@. (No scheduling is implemented for this chip.)
@item i586, pentium
Intel Pentium CPU with no MMX support.
@item pentium-mmx
Intel PentiumMMX CPU based on Pentium core with MMX instruction set support.
@item i686, pentiumpro
-Intel PentiumPro CPU.
+Intel PentiumPro CPU@.
@item pentium2
Intel Pentium2 CPU based on PentiumPro core with MMX instruction set support.
@item pentium3, pentium3m
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
emulated otherwise. Code compiled with this option will run almost everywhere.
The temporary results are computed in 80bit precision instead of precision
specified by the type resulting in slightly different results compared to most
-of other chips. See @option{-ffloat-store} for more detailed description.
+of other chips. See @option{-ffloat-store} for more detailed description.
This is the default choice for i386 compiler.
only in Pentium4 and the future AMD x86-64 chips supports double precision
arithmetics too.
-For i387 you need to use @option{-march=@var{cpu-type}}, @option{-msse} or
-@option{-msse2} switches to enable SSE extensions and make this option
-effective. For x86-64 compiler, these extensions are enabled by default.
+For the i386 compiler, you need to use @option{-march=@var{cpu-type}}, @option{-msse}
+or @option{-msse2} switches to enable SSE extensions and make this option
+effective. For the x86-64 compiler, these extensions are enabled by default.
The resulting code should be considerably faster in the majority of cases and avoid
the numerical instability problems of 387 code, but may break some existing
@item -masm=@var{dialect}
@opindex masm=@var{dialect}
-Output asm instructions using selected @var{dialect}. Supported choices are
+Output asm instructions using selected @var{dialect}. Supported choices are
@samp{intel} or @samp{att} (the default one).
@item -mieee-fp
@itemx -m128bit-long-double
@opindex m96bit-long-double
@opindex m128bit-long-double
-These switches control the size of @code{long double} type. The i386
+These switches control the size of @code{long double} type. The i386
application binary interface specifies the size to be 96 bits,
so @option{-m96bit-long-double} is the default in 32 bit mode.
Generate (or don't) a stop bit immediately before and after volatile asm
statements.
-@item -mb-step
-@opindex mb-step
-Generate code that works around Itanium B step errata.
-
@item -mregister-names
@itemx -mno-register-names
@opindex mregister-names
Generate code for inline divides of integer values
using the maximum throughput algorithm.
+@item -minline-sqrt-min-latency
+@opindex minline-sqrt-min-latency
+Generate code for inline square roots
+using the minimum latency algorithm.
+
+@item -minline-sqrt-max-throughput
+@opindex minline-sqrt-max-throughput
+Generate code for inline square roots
+using the maximum throughput algorithm.
+
@item -mno-dwarf2-asm
@itemx -mdwarf2-asm
@opindex mno-dwarf2-asm
Don't (or do) generate assembler code for the DWARF2 line number debugging
info. This may be useful when not using the GNU assembler.
+@item -mearly-stop-bits
+@itemx -mno-early-stop-bits
+@opindex mearly-stop-bits
+@opindex mno-early-stop-bits
+Allow stop bits to be placed earlier than immediately preceding the
+instruction that triggered the stop bit. This can improve instruction
+scheduling, but does not always do so.
+
@item -mfixed-range=@var{register-range}
@opindex mfixed-range
Generate code treating the given register range as fixed registers.
two registers separated by a dash. Multiple register ranges can be
specified separated by a comma.
-@item -mearly-stop-bits
-@itemx -mno-early-stop-bits
-@opindex mearly-stop-bits
-@opindex mno-early-stop-bits
-Allow stop bits to be placed earlier than immediately preceding the
-instruction that triggered the stop bit. This can improve instruction
-scheduling, but does not always do so.
+@item -mtls-size=@var{tls-size}
+@opindex mtls-size
+Specify bit size of immediate TLS offsets. Valid values are 14, 22, and
+64.
+
+@item -mtune-arch=@var{cpu-type}
+@opindex mtune-arch
+Tune the instruction scheduling for a particular CPU, Valid values are
+itanium, itanium1, merced, itanium2, and mckinley.
+
+@item -mt
+@itemx -pthread
+@opindex mt
+@opindex pthread
+Add support for multithreading using the POSIX threads library. This
+option sets flags for both the preprocessor and linker. It does
+not affect the thread safety of object code produced by the compiler or
+that of libraries supplied with it. These are HP-UX specific flags.
+
+@item -milp32
+@itemx -mlp64
+@opindex milp32
+@opindex mlp64
+Generate code for a 32-bit or 64-bit environment.
+The 32-bit environment sets int, long and pointer to 32 bits.
+The 64-bit environment sets int to 32 bits and long and pointer
+to 64 bits. These are HP-UX specific flags.
+
@end table
@node M32R/D Options
@itemx -mno-mips16
@opindex mips16
@opindex mno-mips16
-Use (do not use) the MIPS16 ISA.
+Use (do not use) the MIPS16 ISA@.
@item -mabi=32
@itemx -mabi=o64
Lift (do not lift) the usual restrictions on the size of the global
offset table.
-GCC normally uses a single instruction to load values from the GOT.
+GCC normally uses a single instruction to load values from the GOT@.
While this is relatively efficient, it will only work if the GOT
is smaller than about 64k. Anything larger will cause the linker
to report an error such as:
@itemx -mno-mips3d
@opindex mips3d
@opindex mno-mips3d
-Use (do not use) the MIPS-3D ASE. @xref{MIPS-3D Built-in Functions}.
+Use (do not use) the MIPS-3D ASE@. @xref{MIPS-3D Built-in Functions}.
The option @option{-mips3d} implies @option{-mpaired-single}.
@item -mint64
@option{-mlong32} for an explanation of the default and the way
that the pointer size is determined.
+This option has been deprecated and will be removed in a future release.
+
@item -mlong64
@opindex mlong64
Force @code{long} types to be 64 bits wide. See @option{-mlong32} for
conditional trap or a break instruction. Using traps results in
smaller code, but is only supported on MIPS II and later. Also, some
versions of the Linux kernel have a bug that prevents trap from
-generating the proper signal (SIGFPE). Use @option{-mdivide-traps} to
+generating the proper signal (@code{SIGFPE}). Use @option{-mdivide-traps} to
allow conditional traps on architectures that support them and
@option{-mdivide-breaks} to force the use of breaks.
@opindex mmad
@opindex mno-mad
Enable (disable) use of the @code{mad}, @code{madu} and @code{mul}
-instructions, as provided by the R4650 ISA.
+instructions, as provided by the R4650 ISA@.
@item -mfused-madd
@itemx -mno-fused-madd
@item -msplit
@opindex msplit
-Generate code for a system with split I&D.
+Generate code for a system with split I&D@.
@item -mno-split
@opindex mno-split
-Generate code for a system without split I&D. This is the default.
+Generate code for a system without split I&D@. This is the default.
@item -munix-asm
@opindex munix-asm
@item -mabi=no-spe
@opindex mabi=no-spe
-Disable Booke SPE ABI extensions for the current ABI.
+Disable Booke SPE ABI extensions for the current ABI@.
@item -misel=@var{yes/no}
@itemx -misel
@option{-mpowerpc}, while @option{-maix32} disables the 64-bit ABI and
implies @option{-mno-powerpc64}. GCC defaults to @option{-maix32}.
-@item -mxl-call
-@itemx -mno-xl-call
-@opindex mxl-call
-@opindex mno-xl-call
-On AIX, pass floating-point arguments to prototyped functions beyond the
-register save area (RSA) on the stack in addition to argument FPRs. The
-AIX calling convention was extended but not initially documented to
+@item -mxl-compat
+@itemx -mno-xl-compat
+@opindex mxl-compat
+@opindex mno-xl-compat
+Produce code that conforms more closely to IBM XLC semantics when using
+AIX-compatible ABI. Pass floating-point arguments to prototyped
+functions beyond the register save area (RSA) on the stack in addition
+to argument FPRs. Do not assume that most significant double in 128
+bit long double value is properly rounded when comparing values.
+
+The AIX calling convention was extended but not initially documented to
handle an obscure K&R C case of calling a function that takes the
address of its arguments with fewer arguments than declared. AIX XL
compilers access floating point arguments which do not fit in the
@itemx -malign-power
@opindex malign-natural
@opindex malign-power
-On AIX, Darwin, and 64-bit PowerPC GNU/Linux, the option
+On AIX, 32-bit Darwin, and 64-bit PowerPC GNU/Linux, the option
@option{-malign-natural} overrides the ABI-defined alignment of larger
types, such as floating-point doubles, on their natural size-based boundary.
The option @option{-malign-power} instructs GCC to follow the ABI-specified
-alignment rules. GCC defaults to the standard alignment defined in the ABI.
+alignment rules. GCC defaults to the standard alignment defined in the ABI@.
+
+On 64-bit Darwin, natural alignment is the default, and @option{-malign-power}
+is not supported.
@item -msoft-float
@itemx -mhard-float
@item -minsert-sched-nops=@var{scheme}
@opindex minsert-sched-nops
This option controls which nop insertion scheme will be used during
-the second scheduling pass. The argument @var{scheme} takes one of the
+the second scheduling pass. The argument @var{scheme} takes one of the
following values:
@var{no}: Don't insert nops.
@var{pad}: Pad with nops any dispatch group which has vacant issue slots,
@item -mabi=no-altivec
@opindex mabi=no-altivec
-Disable AltiVec ABI extensions for the current ABI.
+Disable AltiVec ABI extensions for the current ABI@.
@item -mprototype
@itemx -mno-prototype
@item -mbackchain
@itemx -mno-backchain
-@itemx -mkernel-backchain
@opindex mbackchain
@opindex mno-backchain
-@opindex mkernel-backchain
-In order to provide a backchain the address of the caller's frame
-is stored within the callee's stack frame.
+Store (do not store) the address of the caller's frame as backchain pointer
+into the callee's stack frame.
A backchain may be needed to allow debugging using tools that do not understand
DWARF-2 call frame information.
-For @option{-mno-backchain} no backchain is maintained at all which is the
-default.
-If one of the other options is present the backchain pointer is placed either
-on top of the stack frame (@option{-mkernel-backchain}) or on
-the bottom (@option{-mbackchain}).
-Beside the different backchain location @option{-mkernel-backchain}
-also changes stack frame layout breaking the ABI. This option
-is intended to be used for code which internally needs a backchain but has
-to get by with a limited stack size e.g.@: the linux kernel.
-Internal unwinding code not using DWARF-2 info has to be able to locate the
-return address of a function. That will be eased be the fact that
-the return address of a function is placed two words below the backchain
-pointer.
+When @option{-mno-packed-stack} is in effect, the backchain pointer is stored
+at the bottom of the stack frame; when @option{-mpacked-stack} is in effect,
+the backchain is placed into the topmost word of the 96/160 byte register
+save area.
+
+In general, code compiled with @option{-mbackchain} is call-compatible with
+code compiled with @option{-mmo-backchain}; however, use of the backchain
+for debugging purposes usually requires that the whole binary is built with
+@option{-mbackchain}. Note that the combination of @option{-mbackchain},
+@option{-mpacked-stack} and @option{-mhard-float} is not supported. In order
+to build a linux kernel use @option{-msoft-float}.
+
+The default is to not maintain the backchain.
+
+@item -mpacked-stack
+@item -mno-packed-stack
+@opindex mpacked-stack
+@opindex mno-packed-stack
+Use (do not use) the packed stack layout. When @option{-mno-packed-stack} is
+specified, the compiler uses the all fields of the 96/160 byte register save
+area only for their default purpose; unused fields still take up stack space.
+When @option{-mpacked-stack} is specified, register save slots are densely
+packed at the top of the register save area; unused space is reused for other
+purposes, allowing for more efficient use of the available stack space.
+However, when @option{-mbackchain} is also in effect, the topmost word of
+the save area is always used to store the backchain, and the return address
+register is always saved two words below the backchain.
+
+As long as the stack frame backchain is not used, code generated with
+@option{-mpacked-stack} is call-compatible with code generated with
+@option{-mno-packed-stack}. Note that some non-FSF releases of GCC 2.95 for
+S/390 or zSeries generated code that uses the stack frame backchain at run
+time, not just for debugging purposes. Such code is not call-compatible
+with code compiled with @option{-mpacked-stack}. Also, note that the
+combination of @option{-mbackchain},
+@option{-mpacked-stack} and @option{-mhard-float} is not supported. In order
+to build a linux kernel use @option{-msoft-float}.
+
+The default is to not use the packed stack layout.
@item -msmall-exec
@itemx -mno-small-exec
When @option{-mzarch} is specified, generate code using the
instructions available on z/Architecture.
When @option{-mesa} is specified, generate code using the
-instructions available on ESA/390. Note that @option{-mesa} is
+instructions available on ESA/390. Note that @option{-mesa} is
not possible with @option{-m64}.
When generating code compliant to the GNU/Linux for S/390 ABI,
the default is @option{-mesa}. When generating code compliant
@item -march=@var{cpu-type}
@opindex march
Generate code that will run on @var{cpu-type}, which is the name of a system
-representing a certain processor type. Possible values for
+representing a certain processor type. Possible values for
@var{cpu-type} are @samp{g5}, @samp{g6}, @samp{z900}, and @samp{z990}.
When generating code using the instructions available on z/Architecture,
the default is @option{-march=z900}. Otherwise, the default is
@opindex mno-tpf-trace
Generate code that adds (does not add) in TPF OS specific branches to trace
routines in the operating system. This option is off by default, even
-when compiling for the TPF OS.
+when compiling for the TPF OS@.
@item -mfused-madd
@itemx -mno-fused-madd
the SPARC architecture. This adds the integer multiply, integer divide step
and scan (@code{ffs}) instructions which exist in SPARClite but not in SPARC-V7.
With @option{-mcpu=f930}, the compiler additionally optimizes it for the
-Fujitsu MB86930 chip, which is the original SPARClite, with no FPU. With
+Fujitsu MB86930 chip, which is the original SPARClite, with no FPU@. With
@option{-mcpu=f934}, the compiler additionally optimizes it for the Fujitsu
-MB86934 chip, which is the more recent SPARClite with FPU.
+MB86934 chip, which is the more recent SPARClite with FPU@.
With @option{-mcpu=sparclet}, GCC generates code for the SPARClet variant of
the SPARC architecture. This adds the integer multiply, multiply/accumulate,
@itemx -mno-v8plus
@opindex mv8plus
@opindex mno-v8plus
-With @option{-mv8plus}, GCC generates code for the SPARC-V8+ ABI. The
+With @option{-mv8plus}, GCC generates code for the SPARC-V8+ ABI@. The
difference from the V8 ABI is that the global and out registers are
considered 64-bit wide. This is enabled by default on Solaris in 32-bit
mode for all SPARC-V9 processors.
@table @gcctabopt
@item -mlittle-endian
@opindex mlittle-endian
-Generate code for a processor running in little-endian mode. It is only
+Generate code for a processor running in little-endian mode. It is only
available for a few configurations and most notably not on Solaris.
@item -m32
@item -mv850e
@opindex mv850e
-Specify that the target processor is the V850E. The preprocessor
+Specify that the target processor is the V850E@. The preprocessor
constant @samp{__v850e__} will be defined if this option is used.
If neither @option{-mv850} nor @option{-mv850e} nor @option{-mv850e1}
@opindex fPIC
If supported for the target machine, emit position-independent code,
suitable for dynamic linking and avoiding any limit on the size of the
-global offset table. This option makes a difference on the m68k
-and the SPARC.
+global offset table. This option makes a difference on the m68k,
+PowerPC and SPARC@.
Position-independent code requires special support, and therefore works
only on certain machines.
@item -fpack-struct[=@var{n}]
@opindex fpack-struct
Without a value specified, pack all structure members together without
-holes. When a value is specified (which must be a small power of two), pack
+holes. When a value is specified (which must be a small power of two), pack
structure members according to this value, representing the maximum
alignment (that is, objects with default alignment requirements larger than
this will be output potentially unaligned at the next fitting location.
The default if @option{-fvisibility} isn't specified is
@code{default}, i.e., make every
symbol public---this causes the same behavior as previous versions of
-GCC.
+GCC@.
A good explanation of the benefits offered by ensuring ELF
symbols have the correct visibility is given by ``How To Write
@w{@uref{http://people.redhat.com/~drepper/}})---however a superior
solution made possible by this option to marking things hidden when
the default is public is to make the default hidden and mark things
-public. This is the norm with DLL's on Windows and with @option{-fvisibility=hidden}
+public. This is the norm with DLL's on Windows and with @option{-fvisibility=hidden}
and @code{__attribute__ ((visibility("default")))} instead of
@code{__declspec(dllexport)} you get almost identical semantics with
-identical syntax. This is a great boon to those working with
+identical syntax. This is a great boon to those working with
cross-platform projects.
For those adding visibility support to existing code, you may find
-@samp{#pragma GCC visibility} of use. This works by you enclosing
+@samp{#pragma GCC visibility} of use. This works by you enclosing
the declarations you wish to set visibility for with (for example)
@samp{#pragma GCC visibility push(hidden)} and
-@samp{#pragma GCC visibility pop}. These can be nested up to sixteen
-times. Bear in mind that symbol visibility should be viewed @strong{as
+@samp{#pragma GCC visibility pop}. These can be nested up to sixteen
+times. Bear in mind that symbol visibility should be viewed @strong{as
part of the API interface contract} and thus all new code should
always specify visibility when it is not the default ie; declarations
only for use within the local DSO should @strong{always} be marked explicitly
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