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
+under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``GNU General Public License'' and ``Funding
Free Software'', the Front-Cover texts being (a) (see below), and with
@gccoptlist{-c -S -E -o @var{file} -combine -no-canonical-prefixes @gol
-pipe -pass-exit-codes @gol
-x @var{language} -v -### --help@r{[}=@var{class}@r{[},@dots{}@r{]]} --target-help @gol
---version -wrapper@@@var{file} -fplugin=@var{file} -fplugin-arg-@var{name}=@var{arg}}
+--version -wrapper@@@var{file} -fplugin=@var{file} -fplugin-arg-@var{name}=@var{arg} @gol
+-fdump-ada-spec@r{[}-slim@r{]}}
@item C Language Options
@xref{C Dialect Options,,Options Controlling C Dialect}.
-fno-default-inline -fvisibility-inlines-hidden @gol
-fvisibility-ms-compat @gol
-Wabi -Wconversion-null -Wctor-dtor-privacy @gol
--Wnon-virtual-dtor -Wreorder @gol
+-Wnoexcept -Wnon-virtual-dtor -Wreorder @gol
-Weffc++ -Wstrict-null-sentinel @gol
-Wno-non-template-friend -Wold-style-cast @gol
-Woverloaded-virtual -Wno-pmf-conversions @gol
-Wlogical-op -Wlong-long @gol
-Wmain -Wmissing-braces -Wmissing-field-initializers @gol
-Wmissing-format-attribute -Wmissing-include-dirs @gol
--Wmissing-noreturn -Wno-mudflap @gol
+-Wno-mudflap @gol
-Wno-multichar -Wnonnull -Wno-overflow @gol
-Woverlength-strings -Wpacked -Wpacked-bitfield-compat -Wpadded @gol
-Wparentheses -Wpedantic-ms-format -Wno-pedantic-ms-format @gol
-Wsign-compare -Wsign-conversion -Wstack-protector @gol
-Wstrict-aliasing -Wstrict-aliasing=n @gol
-Wstrict-overflow -Wstrict-overflow=@var{n} @gol
--Wsuggest-attribute=@r{[}const@r{|}pure@r{]} @gol
+-Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{]} @gol
-Wswitch -Wswitch-default -Wswitch-enum -Wsync-nand @gol
--Wsystem-headers -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized @gol
--Wunknown-pragmas -Wno-pragmas @gol
+-Wsystem-headers -Wtrampolines -Wtrigraphs -Wtype-limits -Wundef @gol
+-Wuninitialized -Wunknown-pragmas -Wno-pragmas @gol
-Wunsuffixed-float-constants -Wunused -Wunused-function @gol
-Wunused-label -Wunused-parameter -Wno-unused-result -Wunused-value -Wunused-variable @gol
-Wunused-but-set-parameter -Wunused-but-set-variable -Wvariadic-macros -Wvla @gol
-fearly-inlining -fipa-sra -fexpensive-optimizations -ffast-math @gol
-ffinite-math-only -ffloat-store -fexcess-precision=@var{style} @gol
-fforward-propagate -ffunction-sections @gol
--fgcse -fgcse-after-reload -fgcse-las -fgcse-lm @gol
+-fgcse -fgcse-after-reload -fgcse-las -fgcse-lm -fgraphite-identity @gol
-fgcse-sm -fif-conversion -fif-conversion2 -findirect-inlining @gol
-finline-functions -finline-functions-called-once -finline-limit=@var{n} @gol
-finline-small-functions -fipa-cp -fipa-cp-clone -fipa-matrix-reorg -fipa-pta @gol
-fira-loop-pressure -fno-ira-share-save-slots @gol
-fno-ira-share-spill-slots -fira-verbose=@var{n} @gol
-fivopts -fkeep-inline-functions -fkeep-static-consts @gol
--floop-block -floop-interchange -floop-strip-mine -fgraphite-identity @gol
+-floop-block -floop-interchange -floop-strip-mine @gol
-floop-parallelize-all -flto -flto-compression-level -flto-report -fltrans @gol
-fltrans-output-list -fmerge-all-constants -fmerge-constants -fmodulo-sched @gol
-fmodulo-sched-allow-regmoves -fmove-loop-invariants -fmudflap @gol
-fno-sched-interblock -fno-sched-spec -fno-signed-zeros @gol
-fno-toplevel-reorder -fno-trapping-math -fno-zero-initialized-in-bss @gol
-fomit-frame-pointer -foptimize-register-move -foptimize-sibling-calls @gol
--fpeel-loops -fpredictive-commoning -fprefetch-loop-arrays @gol
+-fpartial-inlining -fpeel-loops -fpredictive-commoning -fprefetch-loop-arrays @gol
-fprofile-correction -fprofile-dir=@var{path} -fprofile-generate @gol
-fprofile-generate=@var{path} @gol
-fprofile-use -fprofile-use=@var{path} -fprofile-values @gol
-fsplit-wide-types -fstack-protector -fstack-protector-all @gol
-fstrict-aliasing -fstrict-overflow -fthread-jumps -ftracer @gol
-ftree-builtin-call-dce -ftree-ccp -ftree-ch -ftree-copy-prop @gol
--ftree-copyrename -ftree-dce @gol
--ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre -ftree-loop-im @gol
--ftree-phiprop -ftree-loop-distribution @gol
+-ftree-copyrename -ftree-dce -ftree-dominator-opts -ftree-dse @gol
+-ftree-forwprop -ftree-fre -ftree-loop-if-convert -ftree-loop-im @gol
+-ftree-phiprop -ftree-loop-distribution -ftree-loop-distribute-patterns @gol
-ftree-loop-ivcanon -ftree-loop-linear -ftree-loop-optimize @gol
-ftree-parallelize-loops=@var{n} -ftree-pre -ftree-pta -ftree-reassoc @gol
-ftree-sink -ftree-sra -ftree-switch-conversion @gol
-fvariable-expansion-in-unroller -fvect-cost-model -fvpt -fweb @gol
-fwhole-program -fwhopr[=@var{n}] -fwpa -fuse-linker-plugin @gol
--param @var{name}=@var{value}
--O -O0 -O1 -O2 -O3 -Os}
+-O -O0 -O1 -O2 -O3 -Os -Ofast}
@item Preprocessor Options
@xref{Preprocessor Options,,Options Controlling the Preprocessor}.
-mcpu=@var{cpu}}
@emph{GNU/Linux Options}
-@gccoptlist{-muclibc}
+@gccoptlist{-mglibc -muclibc -mbionic -mandroid @gol
+-tno-android-cc -tno-android-ld}
@emph{H8/300 Options}
@gccoptlist{-mrelax -mh -ms -mn -mint32 -malign-300}
-mincoming-stack-boundary=@var{num}
-mcld -mcx16 -msahf -mmovbe -mcrc32 -mrecip @gol
-mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -msse4 -mavx @gol
--maes -mpclmul -mfused-madd @gol
+-maes -mpclmul -mfsgsbase -mrdrnd -mf16c -mfused-madd @gol
-msse4a -m3dnow -mpopcnt -mabm -mfma4 -mxop -mlwp @gol
-mthreads -mno-align-stringops -minline-all-stringops @gol
-minline-stringops-dynamically -mstringop-strategy=@var{alg} @gol
-momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs @gol
-mcmodel=@var{code-model} -mabi=@var{name} @gol
-m32 -m64 -mlarge-data-threshold=@var{num} @gol
--msse2avx}
+-msse2avx -mfentry}
@emph{IA-64 Options}
@gccoptlist{-mbig-endian -mlittle-endian -mgnu-as -mgnu-ld -mno-pic @gol
@emph{RS/6000 and PowerPC Options}
@gccoptlist{-mcpu=@var{cpu-type} @gol
-mtune=@var{cpu-type} @gol
+-mcmodel=@var{code-model} @gol
-mpower -mno-power -mpower2 -mno-power2 @gol
-mpowerpc -mpowerpc64 -mno-powerpc @gol
-maltivec -mno-altivec @gol
-mcall-sysv -mcall-netbsd @gol
-maix-struct-return -msvr4-struct-return @gol
-mabi=@var{abi-type} -msecure-plt -mbss-plt @gol
+-mblock-move-inline-limit=@var{num} @gol
-misel -mno-isel @gol
-misel=yes -misel=no @gol
-mspe -mno-spe @gol
-mfloat-gprs=yes -mfloat-gprs=no -mfloat-gprs=single -mfloat-gprs=double @gol
-mprototype -mno-prototype @gol
-msim -mmvme -mads -myellowknife -memb -msdata @gol
--msdata=@var{opt} -mvxworks -G @var{num} -pthread}
+-msdata=@var{opt} -mvxworks -G @var{num} -pthread @gol
+-mrecip -mrecip=@var{opt} -mno-recip -mrecip-precision -mno-recip-precision}
@emph{RX Options}
@gccoptlist{-m64bit-doubles -m32bit-doubles -fpu -nofpu@gol
--mcpu= -patch=@gol
+-mcpu=@gol
-mbig-endian-data -mlittle-endian-data @gol
-msmall-data @gol
-msim -mno-sim@gol
-mtda=@var{n} -msda=@var{n} -mzda=@var{n} @gol
-mapp-regs -mno-app-regs @gol
-mdisable-callt -mno-disable-callt @gol
+-mv850e2v3 @gol
+-mv850e2 @gol
-mv850e1 @gol
-mv850e @gol
-mv850 -mbig-switch}
@emph{Xtensa Options}
@gccoptlist{-mconst16 -mno-const16 @gol
-mfused-madd -mno-fused-madd @gol
+-mforce-no-pic @gol
-mserialize-volatile -mno-serialize-volatile @gol
-mtext-section-literals -mno-text-section-literals @gol
-mtarget-align -mno-target-align @gol
@item @var{file}.h
C, C++, Objective-C or Objective-C++ header file to be turned into a
-precompiled header.
+precompiled header (default), or C, C++ header file to be turned into an
+Ada spec (via the @option{-fdump-ada-spec} switch).
@item @var{file}.cc
@itemx @var{file}.cp
@itemx @var{file}.HPP
@itemx @var{file}.h++
@itemx @var{file}.tcc
-C++ header file to be turned into a precompiled header.
+C++ header file to be turned into a precompiled header or Ada spec.
@item @var{file}.f
@itemx @var{file}.for
Define an argument called @var{key} with a value of @var{value}
for the plugin called @var{name}.
+@item -fdump-ada-spec@r{[}-slim@r{]}
+For C and C++ source and include files, generate corresponding Ada
+specs. @xref{Generating Ada Bindings for C and C++ headers,,, gnat_ugn,
+GNAT User's Guide}, which provides detailed documentation on this feature.
+
@include @value{srcdir}/../libiberty/at-file.texi
@end table
destructors in that class are private, and it has neither friends nor
public static member functions.
+@item -Wnoexcept @r{(C++ and Objective-C++ only)}
+@opindex Wnoexcept
+@opindex Wno-noexcept
+Warn when a noexcept-expression evaluates to false because of a call
+to a function that does not have a non-throwing exception
+specification (i.e. @samp{throw()} or @samp{noexcept}) but is known by
+the compiler to never throw an exception.
+
@item -Wnon-virtual-dtor @r{(C++ and Objective-C++ only)}
@opindex Wnon-virtual-dtor
@opindex Wno-non-virtual-dtor
@end group
@end smallexample
+Also warn for dangerous uses of the
+?: with omitted middle operand GNU extension. When the condition
+in the ?: operator is a boolean expression the omitted value will
+be always 1. Often the user expects it to be a value computed
+inside the conditional expression instead.
+
This warning is enabled by @option{-Wall}.
@item -Wsequence-point
false positives.
@end table
-@item -Wsuggest-attribute=@r{[}const@r{|}pure@r{]}
+@item -Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{]}
@opindex Wsuggest-attribute=
@opindex Wno-suggest-attribute=
Warn for cases where adding an attribute may be beneficial. The
@table @gcctabopt
@item -Wsuggest-attribute=pure
@itemx -Wsuggest-attribute=const
+@itemx -Wsuggest-attribute=noreturn
@opindex Wsuggest-attribute=pure
@opindex Wno-suggest-attribute=pure
@opindex Wsuggest-attribute=const
@opindex Wno-suggest-attribute=const
+@opindex Wsuggest-attribute=noreturn
+@opindex Wno-suggest-attribute=noreturn
Warn about functions which might be candidates for attributes
-@code{pure} or @code{const}. The compiler only warns for functions
-visible in other compilation units or if it cannot prove that the
-function returns normally. A function returns normally if it doesn't
-contain an infinite loop nor returns abnormally by throwing, calling
-@code{abort()} or trapping. This analysis requires option
-@option{-fipa-pure-const}, which is enabled by default at @option{-O}
-and higher. Higher optimization levels improve the accuracy of the
-analysis.
+@code{pure}, @code{const} or @code{noreturn}. The compiler only warns for
+functions visible in other compilation units or (in the case of @code{pure} and
+@code{const}) if it cannot prove that the function returns normally. A function
+returns normally if it doesn't contain an infinite loop nor returns abnormally
+by throwing, calling @code{abort()} or trapping. This analysis requires option
+@option{-fipa-pure-const}, which is enabled by default at @option{-O} and
+higher. Higher optimization levels improve the accuracy of the analysis.
@end table
@item -Warray-bounds
option will @emph{not} warn about unknown pragmas in system
headers---for that, @option{-Wunknown-pragmas} must also be used.
+@item -Wtrampolines
+@opindex Wtrampolines
+@opindex Wno-trampolines
+ Warn about trampolines generated for pointers to nested functions.
+
+ A trampoline is a small piece of data or code that is created at run
+ time on the stack when the address of a nested function is taken, and
+ is used to call the nested function indirectly. For some targets, it
+ is made up of data only and thus requires no special treatment. But,
+ for most targets, it is made up of code and thus requires the stack
+ to be made executable in order for the program to work properly.
+
@item -Wfloat-equal
@opindex Wfloat-equal
@opindex Wno-float-equal
@item -Wshadow
@opindex Wshadow
@opindex Wno-shadow
-Warn whenever a local variable shadows another local variable, parameter or
-global variable or whenever a built-in function is shadowed.
+Warn whenever a local variable or type declaration shadows another variable,
+parameter, type, or class member (in C++), or whenever a built-in function
+is shadowed. Note that in C++, the compiler will not warn if a local variable
+shadows a struct/class/enum, but will warn if it shadows an explicit typedef.
@item -Wlarger-than=@var{len}
@opindex Wlarger-than=@var{len}
This warning is included in @option{-Wextra}. To get other @option{-Wextra}
warnings without this one, use @samp{-Wextra -Wno-missing-field-initializers}.
-@item -Wmissing-noreturn
-@opindex Wmissing-noreturn
-@opindex Wno-missing-noreturn
-Warn about functions which might be candidates for attribute @code{noreturn}.
-Note these are only possible candidates, not absolute ones. Care should
-be taken to manually verify functions actually do not ever return before
-adding the @code{noreturn} attribute, otherwise subtle code generation
-bugs could be introduced. You will not get a warning for @code{main} in
-hosted C environments.
-
@item -Wmissing-format-attribute
@opindex Wmissing-format-attribute
@opindex Wno-missing-format-attribute
-findirect-inlining @gol
-fipa-sra @gol
-foptimize-sibling-calls @gol
+-fpartial-inlining @gol
-fpeephole2 @gol
-fregmove @gol
-freorder-blocks -freorder-functions @gol
-falign-labels -freorder-blocks -freorder-blocks-and-partition @gol
-fprefetch-loop-arrays -ftree-vect-loop-version}
+@item -Ofast
+@opindex Ofast
+Disregard strict standards compliance. @option{-Ofast} enables all
+@option{-O3} optimizations. It also enables optimizations that are not
+valid for all standard compliant programs.
+It turns on @option{-ffast-math}.
+
If you use multiple @option{-O} options, with or without level numbers,
the last such option is the one that is effective.
@end table
Compare the results of several data dependence analyzers. This option
is used for debugging the data dependence analyzers.
+@item -ftree-loop-if-convert
+Attempt to transform conditional jumps in the innermost loops to
+branch-less equivalents. The intent is to remove control-flow from
+the innermost loops in order to improve the ability of the
+vectorization pass to handle these loops. This is enabled by default
+if vectorization is enabled.
+
@item -ftree-loop-distribution
Perform loop distribution. This flag can improve cache performance on
big loop bodies and allow further loop optimizations, like
ENDDO
@end smallexample
+@item -ftree-loop-distribute-patterns
+Perform loop distribution of patterns that can be code generated with
+calls to a library. This flag is enabled by default at @option{-O3}.
+
+This pass distributes the initialization loops and generates a call to
+memset zero. For example, the loop
+@smallexample
+DO I = 1, N
+ A(I) = 0
+ B(I) = A(I) + I
+ENDDO
+@end smallexample
+is transformed to
+@smallexample
+DO I = 1, N
+ A(I) = 0
+ENDDO
+DO I = 1, N
+ B(I) = A(I) + I
+ENDDO
+@end smallexample
+and the initialization loop is transformed into a call to memset zero.
+
@item -ftree-loop-im
@opindex ftree-loop-im
Perform loop invariant motion on trees. This pass moves only invariants that
With this option, the compiler will create multiple copies of some
local variables when unrolling a loop which can result in superior code.
+@item -fpartial-inlining
+@opindex fpartial-inlining
+Inline parts of functions. This option has any effect only
+when inlining itself is turned on by the @option{-finline-functions}
+or @option{-finline-small-functions} options.
+
+Enabled at level @option{-O2}.
+
@item -fpredictive-commoning
@opindex fpredictive-commoning
Perform predictive commoning optimization, i.e., reusing computations
Assume that the current compilation unit represents the whole program being
compiled. All public functions and variables with the exception of @code{main}
and those merged by attribute @code{externally_visible} become static functions
-and in effect are optimized more aggressively by interprocedural optimizers.
+and in effect are optimized more aggressively by interprocedural optimizers. If @command{gold} is used as the linker plugin, @code{externally_visible} attributes are automatically added to functions (not variable yet due to a current @command{gold} issue) that are accessed outside of LTO objects according to resolution file produced by @command{gold}. For other linkers that cannot generate resolution file, explicit @code{externally_visible} attributes are still necessary.
While this option is equivalent to proper use of the @code{static} keyword for
programs consisting of a single file, in combination with option
@option{-combine}, @option{-flto} or @option{-fwhopr} this flag can be used to
by the compiler will be investigated. To those functions, a different
(more restrictive) limit compared to functions declared inline can
be applied.
-The default value is 50.
+The default value is 40.
@item large-function-insns
The limit specifying really large functions. For functions larger than this
vectorization needs to be greater than the value specified by this option
to allow vectorization. The default value is 0.
+@item gcse-cost-distance-ratio
+Scaling factor in calculation of maximum distance an expression
+can be moved by GCSE optimizations. This is currently supported only in
+code hoisting pass. The bigger the ratio, the more agressive code hoisting
+will be with simple expressions, i.e., the expressions which have cost
+less than @option{gcse-unrestricted-cost}. Specifying 0 will disable
+hoisting of simple expressions. The default value is 10.
+
+@item gcse-unrestricted-cost
+Cost, roughly measured as the cost of a single typical machine
+instruction, at which GCSE optimizations will not constrain
+the distance an expression can travel. This is currently
+supported only in code hoisting pass. The lesser the cost,
+the more aggressive code hoisting will be. Specifying 0 will
+allow all expressions to travel unrestricted distances.
+The default value is 3.
+
+@item max-hoist-depth
+The depth of search in the dominator tree for expressions to hoist.
+This is used to avoid quadratic behavior in hoisting algorithm.
+The value of 0 will avoid limiting the search, but may slow down compilation
+of huge functions. The default value is 30.
+
@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
length can be changed using the @option{loop-block-tile-size}
parameter. The default value is 51 iterations.
+@item devirt-type-list-size
+IPA-CP attempts to track all possible types passed to a function's
+parameter in order to perform devirtualization.
+@option{devirt-type-list-size} is the maximum number of types it
+stores per a single formal parameter of a function.
+
@end table
@end table
@samp{arm1136j-s}, @samp{arm1136jf-s}, @samp{mpcore}, @samp{mpcorenovfp},
@samp{arm1156t2-s}, @samp{arm1156t2f-s}, @samp{arm1176jz-s}, @samp{arm1176jzf-s},
@samp{cortex-a5}, @samp{cortex-a8}, @samp{cortex-a9},
-@samp{cortex-r4}, @samp{cortex-r4f}, @samp{cortex-m3},
+@samp{cortex-r4}, @samp{cortex-r4f}, @samp{cortex-m4}, @samp{cortex-m3},
@samp{cortex-m1},
@samp{cortex-m0},
@samp{xscale}, @samp{iwmmxt}, @samp{iwmmxt2}, @samp{ep9312}.
If @option{-msoft-float} is specified this specifies the format of
floating point values.
+If the selected floating-point hardware includes the NEON extension
+(e.g. @option{-mfpu}=@samp{neon}), note that floating-point
+operations will not be used by GCC's auto-vectorization pass unless
+@option{-funsafe-math-optimizations} is also specified. This is
+because NEON hardware does not fully implement the IEEE 754 standard for
+floating-point arithmetic (in particular denormal values are treated as
+zero), so the use of NEON instructions may lead to a loss of precision.
+
@item -mfp16-format=@var{name}
@opindex mfp16-format
Specify the format of the @code{__fp16} half-precision floating-point type.
@table @gcctabopt
@item -mglibc
@opindex mglibc
-Use the GNU C library instead of uClibc. This is the default except
-on @samp{*-*-linux-*uclibc*} targets.
+Use the GNU C library. This is the default except
+on @samp{*-*-linux-*uclibc*} and @samp{*-*-linux-*android*} targets.
@item -muclibc
@opindex muclibc
-Use uClibc instead of the GNU C library. This is the default on
+Use uClibc C library. This is the default on
@samp{*-*-linux-*uclibc*} targets.
+
+@item -mbionic
+@opindex mbionic
+Use Bionic C library. This is the default on
+@samp{*-*-linux-*android*} targets.
+
+@item -mandroid
+@opindex mandroid
+Compile code compatible with Android platform. This is the default on
+@samp{*-*-linux-*android*} targets.
+
+When compiling, this option enables @option{-mbionic}, @option{-fPIC},
+@option{-fno-exceptions} and @option{-fno-rtti} by default. When linking,
+this option makes the GCC driver pass Android-specific options to the linker.
+Finally, this option causes the preprocessor macro @code{__ANDROID__}
+to be defined.
+
+@item -tno-android-cc
+@opindex tno-android-cc
+Disable compilation effects of @option{-mandroid}, i.e., do not enable
+@option{-mbionic}, @option{-fPIC}, @option{-fno-exceptions} and
+@option{-fno-rtti} by default.
+
+@item -tno-android-ld
+@opindex tno-android-ld
+Disable linking effects of @option{-mandroid}, i.e., pass standard Linux
+linking options to the linker.
+
@end table
@node H8/300 Options
@itemx -mno-aes
@itemx -mpclmul
@itemx -mno-pclmul
+@itemx -mfsgsbase
+@itemx -mno-fsgsbase
+@itemx -mrdrnd
+@itemx -mno-rdrnd
+@itemx -mf16c
+@itemx -mno-f16c
@itemx -msse4a
@itemx -mno-sse4a
@itemx -mfma4
@opindex m3dnow
@opindex mno-3dnow
These switches enable or disable the use of instructions in the MMX,
-SSE, SSE2, SSE3, SSSE3, SSE4.1, AVX, AES, PCLMUL, SSE4A, FMA4, XOP,
-LWP, ABM or 3DNow!@: extended instruction sets.
+SSE, SSE2, SSE3, SSSE3, SSE4.1, AVX, AES, PCLMUL, FSGSBASE, RDRND,
+F16C, SSE4A, FMA4, XOP, LWP, ABM or 3DNow!@: extended instruction sets.
These extensions are also available as built-in functions: see
@ref{X86 Built-in Functions}, for details of the functions enabled and
disabled by these switches.
@opindex msse2avx
Specify that the assembler should encode SSE instructions with VEX
prefix. The option @option{-mavx} turns this on by default.
+
+@item -mfentry
+@itemx -mno-fentry
+@opindex mfentry
+If profiling is active @option{-pg} put the profiling
+counter call before prologue.
+Note: On x86 architectures the attribute @code{ms_hook_prologue}
+isn't possible at the moment for @option{-mfentry} and @option{-pg}.
@end table
These @samp{-m} switches are supported in addition to the above
@samp{7400}, @samp{7450}, @samp{750}, @samp{801}, @samp{821}, @samp{823},
@samp{860}, @samp{970}, @samp{8540}, @samp{a2}, @samp{e300c2},
@samp{e300c3}, @samp{e500mc}, @samp{e500mc64}, @samp{ec603e}, @samp{G3},
-@samp{G4}, @samp{G5}, @samp{power}, @samp{power2}, @samp{power3},
+@samp{G4}, @samp{G5}, @samp{titan}, @samp{power}, @samp{power2}, @samp{power3},
@samp{power4}, @samp{power5}, @samp{power5+}, @samp{power6}, @samp{power6x},
@samp{power7}, @samp{common}, @samp{powerpc}, @samp{powerpc64}, @samp{rios},
@samp{rios1}, @samp{rios2}, @samp{rsc}, and @samp{rs64}.
architecture, registers, and mnemonics set by @option{-mcpu}, but the
scheduling parameters set by @option{-mtune}.
-@item -mswdiv
-@itemx -mno-swdiv
-@opindex mswdiv
-@opindex mno-swdiv
-Generate code to compute division as reciprocal estimate and iterative
-refinement, creating opportunities for increased throughput. This
-feature requires: optional PowerPC Graphics instruction set for single
-precision and FRE instruction for double precision, assuming divides
-cannot generate user-visible traps, and the domain values not include
-Infinities, denormals or zero denominator.
+@item -mcmodel=small
+@opindex mcmodel=small
+Generate PowerPC64 code for the small model: The TOC is limited to
+64k.
+
+@item -mcmodel=large
+@opindex mcmodel=large
+Generate PowerPC64 code for the large model: The TOC may be up to 4G
+in size. Other data and code is only limited by the 64-bit address
+space.
@item -maltivec
@itemx -mno-altivec
@itemx -mno-relocatable
@opindex mrelocatable
@opindex mno-relocatable
-On embedded PowerPC systems generate code that allows (does not allow)
-the program to be relocated to a different address at runtime. If you
-use @option{-mrelocatable} on any module, all objects linked together must
-be compiled with @option{-mrelocatable} or @option{-mrelocatable-lib}.
+Generate code that allows (does not allow) a static executable to be
+relocated to a different address at runtime. A simple embedded
+PowerPC system loader should relocate the entire contents of
+@code{.got2} and 4-byte locations listed in the @code{.fixup} section,
+a table of 32-bit addresses generated by this option. For this to
+work, all objects linked together must be compiled with
+@option{-mrelocatable} or @option{-mrelocatable-lib}.
+@option{-mrelocatable} code aligns the stack to an 8 byte boundary.
@item -mrelocatable-lib
@itemx -mno-relocatable-lib
@opindex mrelocatable-lib
@opindex mno-relocatable-lib
-On embedded PowerPC systems generate code that allows (does not allow)
-the program to be relocated to a different address at runtime. Modules
-compiled with @option{-mrelocatable-lib} can be linked with either modules
-compiled without @option{-mrelocatable} and @option{-mrelocatable-lib} or
-with modules compiled with the @option{-mrelocatable} options.
+Like @option{-mrelocatable}, @option{-mrelocatable-lib} generates a
+@code{.fixup} section to allow static executables to be relocated at
+runtime, but @option{-mrelocatable-lib} does not use the smaller stack
+alignment of @option{-mrelocatable}. Objects compiled with
+@option{-mrelocatable-lib} may be linked with objects compiled with
+any combination of the @option{-mrelocatable} options.
@item -mno-toc
@itemx -mtoc
in the @samp{.data} section, and all uninitialized data in the
@samp{.bss} section.
+@item -mblock-move-inline-limit=@var{num}
+@opindex mblock-move-inline-limit
+Inline all block moves (such as calls to @code{memcpy} or structure
+copies) less than or equal to @var{num} bytes. The minimum value for
+@var{num} is 32 bytes on 32-bit targets and 64 bytes on 64-bit
+targets. The default value is target-specific.
+
@item -G @var{num}
@opindex G
@cindex smaller data references (PowerPC)
Adds support for multithreading with the @dfn{pthreads} library.
This option sets flags for both the preprocessor and linker.
+@item -mrecip
+@itemx -mno-recip
+@opindex mrecip
+This option will enable GCC to use the reciprocal estimate and
+reciprocal square root estimate instructions with additional
+Newton-Raphson steps to increase precision instead of doing a divide or
+square root and divide for floating point arguments. You should use
+the @option{-ffast-math} option when using @option{-mrecip} (or at
+least @option{-funsafe-math-optimizations},
+@option{-finite-math-only}, @option{-freciprocal-math} and
+@option{-fno-trapping-math}). Note that while the throughput of the
+sequence is generally higher than the throughput of the non-reciprocal
+instruction, the precision of the sequence can be decreased by up to 2
+ulp (i.e. the inverse of 1.0 equals 0.99999994) for reciprocal square
+roots.
+
+@item -mrecip=@var{opt}
+@opindex mrecip=opt
+This option allows to control which reciprocal estimate instructions
+may be used. @var{opt} is a comma separated list of options, that may
+be preceeded by a @code{!} to invert the option:
+@code{all}: enable all estimate instructions,
+@code{default}: enable the default instructions, equvalent to @option{-mrecip},
+@code{none}: disable all estimate instructions, equivalent to @option{-mno-recip};
+@code{div}: enable the reciprocal approximation instructions for both single and double precision;
+@code{divf}: enable the single precision reciprocal approximation instructions;
+@code{divd}: enable the double precision reciprocal approximation instructions;
+@code{rsqrt}: enable the reciprocal square root approximation instructions for both single and double precision;
+@code{rsqrtf}: enable the single precision reciprocal square root approximation instructions;
+@code{rsqrtd}: enable the double precision reciprocal square root approximation instructions;
+
+So for example, @option{-mrecip=all,!rsqrtd} would enable the
+all of the reciprocal estimate instructions, except for the
+@code{FRSQRTE}, @code{XSRSQRTEDP}, and @code{XVRSQRTEDP} instructions
+which handle the double precision reciprocal square root calculations.
+
+@item -mrecip-precision
+@itemx -mno-recip-precision
+@opindex mrecip-precision
+Assume (do not assume) that the reciprocal estimate instructions
+provide higher precision estimates than is mandated by the powerpc
+ABI. Selecting @option{-mcpu=power6} or @option{-mcpu=power7}
+automatically selects @option{-mrecip-precision}. The double
+precision square root estimate instructions are not generated by
+default on low precision machines, since they do not provide an
+estimate that converges after three steps.
@end table
@node RX Options
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 three types are
supported, the generic @var{RX600} and @var{RX200} series hardware and
the specific @var{RX610} cpu. The default is @var{RX600}.
@opindex mno-app-regs
This option will cause r2 and r5 to be treated as fixed registers.
+@item -mv850e2v3
+@opindex mv850e2v3
+Specify that the target processor is the V850E2V3. The preprocessor
+constants @samp{__v850e2v3__} will be defined if
+this option is used.
+
+@item -mv850e2
+@opindex mv850e2
+Specify that the target processor is the V850E2. The preprocessor
+constants @samp{__v850e2__} will be defined if
+
@item -mv850e1
@opindex mv850e1
Specify that the target processor is the V850E1. The preprocessor
constants @samp{__v850e1__} and @samp{__v850e__} will be defined if
-this option is used.
@item -mv850e
@opindex mv850e
constant @samp{__v850e__} will be defined if this option is used.
If neither @option{-mv850} nor @option{-mv850e} nor @option{-mv850e1}
+nor @option{-mv850e2} nor @option{-mv850e2v3}
are defined then a default target processor will be chosen and the
relevant @samp{__v850*__} preprocessor constant will be defined.
@item -mdisable-callt
@opindex mdisable-callt
This option will suppress generation of the CALLT instruction for the
-v850e and v850e1 flavors of the v850 architecture. The default is
+v850e, v850e1, v850e2 and v850e2v3 flavors of the v850 architecture. The default is
@option{-mno-disable-callt} which allows the CALLT instruction to be used.
@end table
The default is @option{-mserialize-volatile}. Use
@option{-mno-serialize-volatile} to omit the @code{MEMW} instructions.
+@item -mforce-no-pic
+@opindex mforce-no-pic
+For targets, like GNU/Linux, where all user-mode Xtensa code must be
+position-independent code (PIC), this option disables PIC for compiling
+kernel code.
+
@item -mtext-section-literals
@itemx -mno-text-section-literals
@opindex mtext-section-literals
An overview of these techniques, their benefits and how to use them
is at @w{@uref{http://gcc.gnu.org/wiki/Visibility}}.
+@item -fstrict-volatile-bitfields
+This option should be used if accesses to volatile bitfields (or other
+structure fields, although the compiler usually honors those types
+anyway) should use a single access in a mode of the same size as the
+container's type, aligned to a natural alignment if possible. For
+example, targets with memory-mapped peripheral registers might require
+all such accesses to be 16 bits wide; with this flag the user could
+declare all peripheral bitfields as ``unsigned short'' (assuming short
+is 16 bits on these targets) to force GCC to use 16 bit accesses
+instead of, perhaps, a more efficient 32 bit access.
+
+If this option is disabled, the compiler will use the most efficient
+instruction. In the previous example, that might be a 32-bit load
+instruction, even though that will access bytes that do not contain
+any portion of the bitfield, or memory-mapped registers unrelated to
+the one being updated.
+
+If the target requires strict alignment, and honoring the container
+type would require violating this alignment, a warning is issued.
+However, the access happens as the user requested, under the
+assumption that the user knows something about the target hardware
+that GCC is unaware of.
+
+The default value of this option is determined by the application binary
+interface for the target processor.
+
@end table
@c man end