-fno-default-inline -fvisibility-inlines-hidden @gol
-Wabi -Wctor-dtor-privacy @gol
-Wnon-virtual-dtor -Wreorder @gol
--Weffc++ -Wno-deprecated @gol
+-Weffc++ -Wno-deprecated -Wstrict-null-sentinel @gol
-Wno-non-template-friend -Wold-style-cast @gol
-Woverloaded-virtual -Wno-pmf-conversions @gol
-Wsign-promo}
-fconstant-string-class=@var{class-name} @gol
-fgnu-runtime -fnext-runtime @gol
-fno-nil-receivers @gol
+-fobjc-call-cxx-cdtors @gol
+-fobjc-direct-dispatch @gol
-fobjc-exceptions @gol
+-fobjc-gc @gol
-freplace-objc-classes @gol
-fzero-link @gol
-gen-decls @gol
--Wno-protocol -Wselector -Wundeclared-selector}
+-Wassign-intercept @gol
+-Wno-protocol -Wselector @gol
+-Wstrict-selector-match @gol
+-Wundeclared-selector}
@item Language Independent Options
@xref{Language Independent Options,,Options to Control Diagnostic Messages Formatting}.
@gccoptlist{-fmessage-length=@var{n} @gol
--fdiagnostics-show-location=@r{[}once@r{|}every-line@r{]}}
+-fdiagnostics-show-location=@r{[}once@r{|}every-line@r{]}} @gol
+-fdiagnostics-show-options
@item Warning Options
@xref{Warning Options,,Options to Request or Suppress Warnings}.
@gccoptlist{-fsyntax-only -pedantic -pedantic-errors @gol
--w -Wextra -Wall -Waggregate-return @gol
+-w -Wextra -Wall -Waggregate-return -Wno-attributes @gol
-Wcast-align -Wcast-qual -Wchar-subscripts -Wcomment @gol
-Wconversion -Wno-deprecated-declarations @gol
-Wdisabled-optimization -Wno-div-by-zero -Wno-endif-labels @gol
-Wformat-security -Wformat-y2k @gol
-Wimplicit -Wimplicit-function-declaration -Wimplicit-int @gol
-Wimport -Wno-import -Winit-self -Winline @gol
+-Wno-int-to-pointer-cast @gol
-Wno-invalid-offsetof -Winvalid-pch @gol
-Wlarger-than-@var{len} -Wlong-long @gol
-Wmain -Wmissing-braces -Wmissing-field-initializers @gol
-Wmissing-format-attribute -Wmissing-include-dirs @gol
-Wmissing-noreturn @gol
-Wno-multichar -Wnonnull -Wpacked -Wpadded @gol
--Wparentheses -Wpointer-arith -Wredundant-decls @gol
+-Wparentheses -Wpointer-arith -Wno-pointer-to-int-cast @gol
+-Wredundant-decls @gol
-Wreturn-type -Wsequence-point -Wshadow @gol
-Wsign-compare -Wstrict-aliasing -Wstrict-aliasing=2 @gol
-Wswitch -Wswitch-default -Wswitch-enum @gol
-fdump-tree-sra@r{[}-@var{n}@r{]} @gol
-fdump-tree-salias @gol
-fdump-tree-fre@r{[}-@var{n}@r{]} @gol
+-fdump-tree-vrp@r{[}-@var{n}@r{]} @gol
-ftree-vectorizer-verbose=@var{n} @gol
+-fdump-tree-storeccp@r{[}-@var{n}@r{]} @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
-ftree-dominator-opts -ftree-dse -ftree-copyrename -ftree-sink @gol
-ftree-ch -ftree-sra -ftree-ter -ftree-lrs -ftree-fre -ftree-vectorize @gol
-ftree-salias -fweb @gol
+-ftree-copy-prop -ftree-store-ccp -ftree-store-copy-prop @gol
--param @var{name}=@var{value}
-O -O0 -O1 -O2 -O3 -Os}
-mxgot -mno-xgot -mgp32 -mgp64 -mfp32 -mfp64 @gol
-mhard-float -msoft-float -msingle-float -mdouble-float @gol
-mpaired-single -mips3d @gol
--mint64 -mlong64 -mlong32 -msym32 -mno-sym32 @gol
+-mlong64 -mlong32 -msym32 -mno-sym32 @gol
-G@var{num} -membedded-data -mno-embedded-data @gol
-muninit-const-in-rodata -mno-uninit-const-in-rodata @gol
-msplit-addresses -mno-split-addresses @gol
-minsert-sched-nops=@var{scheme} @gol
-mcall-sysv -mcall-netbsd @gol
-maix-struct-return -msvr4-struct-return @gol
--mabi=altivec -mabi=no-altivec @gol
--mabi=spe -mabi=no-spe @gol
+-mabi=@var{abi-type} -msecure-plt -mbss-plt @gol
+-misel -mno-isel @gol
-misel=yes -misel=no @gol
+-mspe -mno-spe @gol
-mspe=yes -mspe=no @gol
+-mvrsave -mno-vrsave @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
-mb -ml -mdalign -mrelax @gol
-mbigtable -mfmovd -mhitachi -mrenesas -mno-renesas -mnomacsave @gol
-mieee -misize -mpadstruct -mspace @gol
--mprefergot -musermode}
+-mprefergot -musermode -multcost=@var{number} -mdiv=@var{strategy} @gol
+-mdivsi3_libfunc=@var{name} @gol
+-madjust-unroll -mindexed-addressing -mgettrcost=@var{number} -mpt-fixed @gol
+ -minvalid-symbols}
@emph{SPARC Options}
@gccoptlist{-mcpu=@var{cpu-type} @gol
-finhibit-size-directive -finstrument-functions @gol
-fno-common -fno-ident @gol
-fpcc-struct-return -fpic -fPIC -fpie -fPIE @gol
+-fno-jump-tables @gol
-freg-struct-return -fshared-data -fshort-enums @gol
-fshort-double -fshort-wchar @gol
-fverbose-asm -fpack-struct[=@var{n}] -fstack-check @gol
the last two letters must both be literally @samp{x}. Likewise,
@samp{.C} refers to a literal capital C@.
+@item @var{file}.mm
+@itemx @var{file}.M
+Objective-C++ source code which must be preprocessed.
+
+@item @var{file}.mii
+Objective-C++ source code which should not be preprocessed.
+
@item @var{file}.hh
@itemx @var{file}.H
C++ header file to be turned into a precompiled header.
@opindex Wno-deprecated
Do not warn about usage of deprecated features. @xref{Deprecated Features}.
+@item -Wstrict-null-sentinel @r{(C++ only)}
+@opindex Wstrict-null-sentinel
+Warn also about the use of an uncasted @code{NULL} as sentinel. When
+compiling only with GCC this is a valid sentinel, as @code{NULL} is defined
+to @code{__null}. Although it is a null pointer constant not a null pointer,
+it is guaranteed to of the same size as a pointer. But this use is
+not portable across different compilers.
+
@item -Wno-non-template-friend @r{(C++ only)}
@opindex Wno-non-template-friend
Disable warnings when non-templatized friend functions are declared
to be used. Currently, this option is only available in conjunction with
the NeXT runtime on Mac OS X 10.3 and later.
+@item -fobjc-call-cxx-cdtors
+@opindex fobjc-call-cxx-cdtors
+For each Objective-C class, check if any of its instance variables is a
+C++ object with a non-trivial default constructor. If so, synthesize a
+special @code{- (id) .cxx_construct} instance method that will run
+non-trivial default constructors on any such instance variables, in order,
+and then return @code{self}. Similarly, check if any instance variable
+is a C++ object with a non-trivial destructor, and if so, synthesize a
+special @code{- (void) .cxx_destruct} method that will run
+all such default destructors, in reverse order.
+
+The @code{- (id) .cxx_construct} and/or @code{- (void) .cxx_destruct} methods
+thusly generated will only operate on instance variables declared in the
+current Objective-C class, and not those inherited from superclasses. It
+is the responsibility of the Objective-C runtime to invoke all such methods
+in an object's inheritance hierarchy. The @code{- (id) .cxx_construct} methods
+will be invoked by the runtime immediately after a new object
+instance is allocated; the @code{- (void) .cxx_destruct} methods will
+be invoked immediately before the runtime deallocates an object instance.
+
+As of this writing, only the NeXT runtime on Mac OS X 10.4 and later has
+support for invoking the @code{- (id) .cxx_construct} and
+@code{- (void) .cxx_destruct} methods.
+
+@item -fobjc-direct-dispatch
+@opindex fobjc-direct-dispatch
+Allow fast jumps to the message dispatcher. On Darwin this is
+accomplished via the comm page.
+
@item -fobjc-exceptions
@opindex fobjc-exceptions
Enable syntactic support for structured exception handling in Objective-C,
@code{@@synchronized} blocks is allowed, and will cause the guarding object
to be unlocked properly.
+@item -fobjc-gc
+@opindex fobjc-gc
+Enable garbage collection (GC) in Objective-C and Objective-C++ programs.
+
@item -freplace-objc-classes
@opindex freplace-objc-classes
Emit a special marker instructing @command{ld(1)} not to statically link in
Dump interface declarations for all classes seen in the source file to a
file named @file{@var{sourcename}.decl}.
+@item -Wassign-intercept
+@opindex Wassign-intercept
+Warn whenever an Objective-C assignment is being intercepted by the
+garbage collector.
+
@item -Wno-protocol
@opindex Wno-protocol
If a class is declared to implement a protocol, a warning is issued for
found during compilation, or because the @option{-fsyntax-only} option is
being used.
+@item -Wstrict-selector-match
+@opindex Wstrict-selector-match
+Warn if multiple methods with differing argument and/or return types are
+found for a given selector when attempting to send a message using this
+selector to a receiver of type @code{id} or @code{Class}. When this flag
+is off (which is the default behavior), the compiler will omit such warnings
+if any differences found are confined to types which share the same size
+and alignment.
+
@item -Wundeclared-selector
@opindex Wundeclared-selector
Warn if a @code{@@selector(@dots{})} expression referring to an
prefix) for physical lines that result from the process of breaking
a message which is too long to fit on a single line.
+@item -fdiagnostics-show-options
+@opindex fdiagnostics-show-options
+This option instructs the diagnostic machinery to add text to each
+diagnostic emitted, which indicates which command line option directly
+controls that diagnostic, when such an option is known to the
+diagnostic machinery.
+
@end table
@node Warning Options
If you want to warn about code which uses the uninitialized value of the
variable in its own initializer, use the @option{-Winit-self} option.
-These warnings occur only for variables that are candidates for
-register allocation. Therefore, they do not occur for a variable that
-is declared @code{volatile}, or whose address is taken, or whose size
-is other than 1, 2, 4 or 8 bytes. Also, they do not occur for
-structures, unions or arrays, even when they are in registers.
+These warnings occur for individual uninitialized or clobbered
+elements of structure, union or array variables as well as for
+variables which are uninitialized or clobbered as a whole. They do
+not occur for variables or elements declared @code{volatile}. Because
+these warnings depend on optimization, the exact variables or elements
+for which there are warnings will depend on the precise optimization
+options and version of GCC used.
Note that there may be no warning about a variable that is used only
to compute a value that itself is never used, because such
called. (In languages where you can return an array, this also elicits
a warning.)
+@item -Wno-attributes
+@opindex Wno-attributes
+@opindex Wattributes
+Do not warn if an unexpected @code{__attribute__} is used, such as
+unrecognized attributes, function attributes applied to variables,
+etc. This will not stop errors for incorrect use of supported
+attributes.
+
@item -Wstrict-prototypes @r{(C only)}
@opindex Wstrict-prototypes
Warn if a function is declared or defined without specifying the
The compiler uses a variety of heuristics to determine whether or not
to inline a function. For example, the compiler takes into account
-the size of the function being inlined and the the amount of inlining
+the size of the function being inlined and the amount of inlining
that has already been done in the current function. Therefore,
seemingly insignificant changes in the source program can cause the
warnings produced by @option{-Winline} to appear or disappear.
The restrictions on @samp{offsetof} may be relaxed in a future version
of the C++ standard.
+@item -Wno-int-to-pointer-cast @r{(C only)}
+@opindex Wno-int-to-pointer-cast
+Suppress warnings from casts to pointer type of an integer of a
+different size.
+
+@item -Wno-pointer-to-int-cast @r{(C only)}
+@opindex Wno-pointer-to-int-cast
+Suppress warnings from casts from a pointer to an integer type of a
+different size.
+
@item -Winvalid-pch
@opindex Winvalid-pch
Warn if a precompiled header (@pxref{Precompiled Headers}) is found in
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}).
+@xref{Cross-profiling}.
@cindex @command{gcov}
@item --coverage
@opindex fdump-rtl-btl
@opindex fdump-rtl-dbr
@option{-dd} and @option{-fdump-rtl-btl} enable dumping after branch
-target load optimization, to to @file{@var{file}.31.btl}. @option{-dd}
+target load optimization, to @file{@var{file}.31.btl}. @option{-dd}
and @option{-fdump-rtl-dbr} enable dumping after delayed branch
scheduling, to @file{@var{file}.36.dbr}.
use diff on debugging dumps for compiler invocations with different
options, in particular with and without @option{-g}.
-@item -fdump-translation-unit @r{(C and C++ only)}
-@itemx -fdump-translation-unit-@var{options} @r{(C and C++ only)}
+@item -fdump-translation-unit @r{(C++ only)}
+@itemx -fdump-translation-unit-@var{options} @r{(C++ only)}
@opindex fdump-translation-unit
Dump a representation of the tree structure for the entire translation
unit to a file. The file name is made by appending @file{.tu} to the
Dump each function after CCP@. The file name is made by appending
@file{.ccp} to the source file name.
+@item storeccp
+@opindex fdump-tree-storeccp
+Dump each function after STORE-CCP. The file name is made by appending
+@file{.storeccp} to the source file name.
+
@item pre
@opindex fdump-tree-pre
Dump trees after partial redundancy elimination. The file name is made
Dump trees after full redundancy elimination. The file name is made
by appending @file{.fre} to the source file name.
+@item copyprop
+@opindex fdump-tree-copyprop
+Dump trees after copy propagation. The file name is made
+by appending @file{.copyprop} to the source file name.
+
+@item store_copyprop
+@opindex fdump-tree-store_copyprop
+Dump trees after store copy-propagation. The file name is made
+by appending @file{.store_copyprop} to the source file name.
+
@item dce
@opindex fdump-tree-dce
Dump each function after dead code elimination. The file name is made by
Dump each function after applying vectorization of loops. The file name is
made by appending @file{.vect} to the source file name.
+@item vrp
+@opindex fdump-tree-vrp
+Dump each function after Value Range Propagation (VRP). The file name
+is made by appending @file{.vrp} to the source file name.
+
@item all
@opindex fdump-tree-all
Enable all the available tree dumps with the flags provided in this option.
-fif-conversion2 @gol
-ftree-ccp @gol
-ftree-dce @gol
--ftree-dom @gol
+-ftree-dominator-opts @gol
-ftree-dse @gol
-ftree-ter @gol
-ftree-lrs @gol
-funit-at-a-time @gol
-falign-functions -falign-jumps @gol
-falign-loops -falign-labels @gol
+-ftree-vrp @gol
-ftree-pre}
Please note the warning under @option{-fgcse} about
parameters controlling inlining.
@emph{Note:} pseudo instruction represents, in this particular context, an
-abstract measurement of function's size. In no way, it represents a count
+abstract measurement of function's size. In no way does it represent a count
of assembly instructions and as such its exact meaning might change from one
release to an another.
This analysis faster than PRE, though it exposes fewer redundancies.
This flag is enabled by default at @option{-O} and higher.
+@item -ftree-copy-prop
+Perform copy propagation on trees. This pass eliminates unnecessary
+copy operations. This flag is enabled by default at @option{-O} and
+higher.
+
+@item -ftree-store-copy-prop
+Perform copy propagation of memory loads and stores. This pass
+eliminates unnecessary copy operations in memory references
+(structures, global variables, arrays, etc). This flag is enabled by
+default at @option{-O2} and higher.
+
@item -ftree-salias
Perform structural alias analysis on trees. This flag
is enabled by default at @option{-O} and higher.
enabled by default at @option{-O} and higher.
@item -ftree-ccp
-Perform sparse conditional constant propagation (CCP) on trees. This flag
-is enabled by default at @option{-O} and higher.
+Perform sparse conditional constant propagation (CCP) on trees. This
+pass only operates on local scalar variables and is enabled by default
+at @option{-O} and higher.
+
+@item -ftree-store-ccp
+Perform sparse conditional constant propagation (CCP) on trees. This
+pass operates on both local scalar variables and memory stores and
+loads (global variables, structures, arrays, etc). This flag is
+enabled by default at @option{-O2} and higher.
@item -ftree-dce
Perform dead code elimination (DCE) on trees. This flag is enabled by
@item -ftree-loop-im
Perform loop invariant motion on trees. This pass moves only invariants that
-would be hard to handle on rtl level (function calls, operations that expand to
+would be hard to handle at RTL level (function calls, operations that expand to
nontrivial sequences of insns). With @option{-funswitch-loops} it also moves
operands of conditions that are invariant out of the loop, so that we can use
just trivial invariantness analysis in loop unswitching. The pass also includes
@item -ftree-vectorize
Perform loop vectorization on trees.
+@item -ftree-vrp
+Perform Value Range Propagation on trees. This is similar to the
+constant propagation pass, but instead of values, ranges of values are
+propagated. This allows the optimizers to remove unnecessary range
+checks like array bound checks and null pointer checks. This is
+enabled by default at @option{-O2} and higher. Null pointer check
+elimination is only done if @option{-fdelete-null-pointer-checks} is
+enabled.
+
@item -ftracer
@opindex ftracer
Perform tail duplication to enlarge superblock size. This transformation
we always try to remove unnecessary ivs from the set during its
optimization when a new iv is added to the set.
+@item scev-max-expr-size
+Bound on size of expressions used in the scalar evolutions analyzer.
+Large expressions slow the analyzer.
+
@item max-iterations-to-track
The maximum number of iterations of a loop the brute force algorithm
compiler's memory usage and increasing its speed. This sets the maximum
value of a shared integer constant's. The default value is 256.
+@item min-virtual-mappings
+Specifies the minimum number of virtual mappings in the incremental
+SSA updater that should be registered to trigger the virtual mappings
+heuristic defined by virtual-mappings-ratio. The default value is
+100.
+
+@item virtual-mappings-ratio
+If the number of virtual mappings is virtual-mappings-ratio bigger
+than the number of virtual symbols to be updated, then the incremental
+SSA updater switches to a full update for those symbols. The default
+ratio is 3.
+
@end table
@end table
options, usually for compatibility with other compilers on the same
platform.
-These options are defined by the macro @code{TARGET_SWITCHES} in the
-machine description. The default for the options is also defined by
-that macro, which enables you to change the defaults.
-
@c This list is ordered alphanumerically by subsection name.
@c It should be the same order and spelling as these options are listed
@c in Machine Dependent Options
Don't generate extra code to prevent speculative loads from occurring.
@item -mlow-64k
-@opindex
+@opindex mlow-64k
When enabled, the compiler is free to take advantage of the knowledge that
the entire program fits into the low 64k of memory.
Use (do not use) the MIPS-3D ASE@. @xref{MIPS-3D Built-in Functions}.
The option @option{-mips3d} implies @option{-mpaired-single}.
-@item -mint64
-@opindex mint64
-Force @code{int} and @code{long} types to be 64 bits wide. See
-@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
@samp{860}, @samp{970}, @samp{8540}, @samp{common}, @samp{ec603e}, @samp{G3},
@samp{G4}, @samp{G5}, @samp{power}, @samp{power2}, @samp{power3},
@samp{power4}, @samp{power5}, @samp{powerpc}, @samp{powerpc64},
-@samp{rios}, @samp{rios1}, @samp{rios2}, @samp{rsc}, and @samp{rs64a}.
+@samp{rios}, @samp{rios1}, @samp{rios2}, @samp{rsc}, and @samp{rs64}.
@option{-mcpu=common} selects a completely generic processor. Code
generated under this option will run on any POWER or PowerPC processor.
@option{-mabi=altivec} to adjust the current ABI with AltiVec ABI
enhancements.
+@item -mvrsave
+@item -mno-vrsave
+@opindex mvrsave
+@opindex mno-vrsave
+Generate VRSAVE instructions when generating AltiVec code.
+
@item -mabi=spe
@opindex mabi=spe
Extend the current ABI with SPE ABI extensions. This does not change
@opindex mabi=no-spe
Disable Booke SPE ABI extensions for the current ABI@.
-@item -misel=@var{yes/no}
-@itemx -misel
+@item -msecure-plt
+@opindex msecure-plt
+Generate code that allows ld and ld.so to build executables and shared
+libraries with non-exec .plt and .got sections. This is a PowerPC
+32-bit SYSV ABI option.
+
+@item -mbss-plt
+@opindex mbss-plt
+Generate code that uses a BSS .plt section that ld.so fills in, and
+requires .plt and .got sections that are both writable and executable.
+This is a PowerPC 32-bit SYSV ABI option.
+
+@item -misel
+@itemx -mno-isel
@opindex misel
+@opindex mno-isel
This switch enables or disables the generation of ISEL instructions.
-@item -mspe=@var{yes/no}
-@itemx -mspe
+@item -misel=@var{yes/no}
+This switch has been deprecated. Use @option{-misel} and
+@option{-mno-isel} instead.
+
+@item -mspe
+@itemx -mno-isel
@opindex mspe
+@opindex mno-spe
This switch enables or disables the generation of SPE simd
instructions.
+@item -mspe=@var{yes/no}
+This option has been deprecated. Use @option{-mspe} and
+@option{-mno-spe} instead.
+
@item -mfloat-gprs=@var{yes/single/double/no}
@itemx -mfloat-gprs
@opindex mfloat-gprs
Return structures smaller than 8 bytes in registers (as specified by the
SVR4 ABI)@.
-@item -mabi=altivec
-@opindex mabi=altivec
-Extend the current ABI with AltiVec ABI extensions. This does not
-change the default ABI, instead it adds the AltiVec ABI extensions to
-the current ABI@.
-
-@item -mabi=no-altivec
-@opindex mabi=no-altivec
-Disable AltiVec ABI extensions for the current ABI@.
+@item -mabi=@var{abi-type}
+@opindex mabi
+Extend the current ABI with a particular extension, or remove such extension.
+Valid values are @var{altivec}, @var{no-altivec}, @var{spe},
+@var{no-spe}@.
@item -mprototype
@itemx -mno-prototype
@item -mieee
@opindex mieee
Increase IEEE-compliance of floating-point code.
+At the moment, this is equivalent to @option{-fno-finite-math-only}.
+When generating 16 bit SH opcodes, getting IEEE-conforming results for
+comparisons of NANs / infinities incurs extra overhead in every
+floating point comparison, therefore the default is set to
+@option{-ffinite-math-only}.
@item -misize
@opindex misize
entries, after fixing up a trampoline. This library function call
doesn't assume it can write to the whole memory address space. This
is the default when the target is @code{sh-*-linux*}.
+
+@item -multcost=@var{number}
+@opindex multcost=@var{number}
+Set the cost to assume for a multiply insn.
+
+@item -mdiv=@var{strategy}
+@opindex mdiv=@var{strategy}
+Set the division strategy to use for SHmedia code. @var{strategy} must be
+one of: call, call2, fp, inv, inv:minlat, inv20u, inv20l, inv:call,
+inv:call2, inv:fp .
+"fp" performs the operation in floating point. This has a very high latency,
+but needs only a few instructions, so it might be a good choice if
+your code has enough easily exploitable ILP to allow the compiler to
+schedule the floating point instructions together with other instructions.
+Division by zero causes a floating point exception.
+"inv" uses integer operations to calculate the inverse of the divisor,
+and then multiplies the dividend with the inverse. This strategy allows
+cse and hoisting of the inverse calculation. Division by zero calculates
+an unspecified result, but does not trap.
+"inv:minlat" is a variant of "inv" where if no cse / hoisting opportunities
+have been found, or if the entire operation has been hoisted to the same
+place, the last stages of the inverse calculation are intertwined with the
+final multiply to reduce the overall latency, at the expense of using a few
+more instructions, and thus offering fewer scheduling opportunities with
+other code.
+"call" calls a library function that usually implements the inv:minlat
+strategy.
+This gives high code density for m5-*media-nofpu compilations.
+"call2" uses a different entry point of the same library function, where it
+assumes that a pointer to a lookup table has already been set up, which
+exposes the pointer load to cse / code hoisting optimizations.
+"inv:call", "inv:call2" and "inv:fp" all use the "inv" algorithm for initial
+code generation, but if the code stays unoptimized, revert to the "call",
+"call2", or "fp" strategies, respectively. Note that the
+potentially-trapping side effect of division by zero is carried by a
+separate instruction, so it is possible that all the integer instructions
+are hoisted out, but the marker for the side effect stays where it is.
+A recombination to fp operations or a call is not possible in that case.
+"inv20u" and "inv20l" are variants of the "inv:minlat" strategy. In the case
+that the inverse calculation was nor separated from the multiply, they speed
+up division where the dividend fits into 20 bits (plus sign where applicable),
+by inserting a test to skip a number of operations in this case; this test
+slows down the case of larger dividends. inv20u assumes the case of a such
+a small dividend to be unlikely, and inv20l assumes it to be likely.
+
+@item -mdivsi3_libfunc=@var{name}
+@opindex mdivsi3_libfunc=@var{name}
+Set the name of the library function used for 32 bit signed division to
+@var{name}. This only affect the name used in the call and inv:call
+division strategies, and the compiler will still expect the same
+sets of input/output/clobbered registers as if this option was not present.
+
+@item -madjust-unroll
+@opindex madjust-unroll
+Throttle unrolling to avoid thrashing target registers.
+This option only has an effect if the gcc code base supports the
+TARGET_ADJUST_UNROLL_MAX target hook.
+
+@item -mindexed-addressing
+@opindex mindexed-addressing
+Enable the use of the indexed addressing mode for SHmedia32/SHcompact.
+This is only safe if the hardware and/or OS implement 32 bit wrap-around
+semantics for the indexed addressing mode. The architecture allows the
+implementation of processors with 64 bit MMU, which the OS could use to
+get 32 bit addressing, but since no current hardware implementation supports
+this or any other way to make the indexed addressing mode safe to use in
+the 32 bit ABI, the default is -mno-indexed-addressing.
+
+@item -mgettrcost=@var{number}
+@opindex mgettrcost=@var{number}
+Set the cost assumed for the gettr instruction to @var{number}.
+The default is 2 if @option{-mpt-fixed} is in effect, 100 otherwise.
+
+@item -mpt-fixed
+@opindex mpt-fixed
+Assume pt* instructions won't trap. This will generally generate better
+scheduled code, but is unsafe on current hardware. The current architecture
+definition says that ptabs and ptrel trap when the target anded with 3 is 3.
+This has the unintentional effect of making it unsafe to schedule ptabs /
+ptrel before a branch, or hoist it out of a loop. For example,
+__do_global_ctors, a part of libgcc that runs constructors at program
+startup, calls functions in a list which is delimited by -1. With the
+-mpt-fixed option, the ptabs will be done before testing against -1.
+That means that all the constructors will be run a bit quicker, but when
+the loop comes to the end of the list, the program crashes because ptabs
+loads -1 into a target register. Since this option is unsafe for any
+hardware implementing the current architecture specification, the default
+is -mno-pt-fixed. Unless the user specifies a specific cost with
+@option{-mgettrcost}, -mno-pt-fixed also implies @option{-mgettrcost=100};
+this deters register allocation using target registers for storing
+ordinary integers.
+
+@item -minvalid-symbols
+@opindex minvalid-symbols
+Assume symbols might be invalid. Ordinary function symbols generated by
+the compiler will always be valid to load with movi/shori/ptabs or
+movi/shori/ptrel, but with assembler and/or linker tricks it is possible
+to generate symbols that will cause ptabs / ptrel to trap.
+This option is only meaningful when @option{-mno-pt-fixed} is in effect.
+It will then prevent cross-basic-block cse, hoisting and most scheduling
+of symbol loads. The default is @option{-mno-invalid-symbols}.
@end table
@node SPARC Options
Usually these options are used when @option{-pie} GCC option will be
used during linking.
+@item -fno-jump-tables
+@opindex fno-jump-tables
+Do not use jump tables for switch statements even where it would be
+more efficient than other code generation strategies. This option is
+of use in conjunction with @option{-fpic} or @option{-fPIC} for
+building code which forms part of a dynamic linker and cannot
+reference the address of a jump table. On some targets, jump tables
+do not require a GOT and this option is not needed.
+
@item -ffixed-@var{reg}
@opindex ffixed
Treat the register named @var{reg} as a fixed register; generated code
@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}.
+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
`precompile' a header file; then, if builds can use the precompiled
header file they will be much faster.
-@strong{Caution:} There are a few known situations where GCC will
-crash when trying to use a precompiled header. If you have trouble
-with a precompiled header, you should remove the precompiled header
-and compile without it. In addition, please use GCC's on-line
-defect-tracking system to report any problems you encounter with
-precompiled headers. @xref{Bugs}.
-
To create a precompiled header file, simply compile it as you would any
other file, if necessary using the @option{-x} option to make the driver
treat it as a C or C++ header file. You will probably want to use a
compilation.
@item
-The precompiled header file must be produced by the same compiler
-version and configuration as the current compilation is using.
-The easiest way to guarantee this is to use the same compiler binary
-for creating and using precompiled headers.
+The precompiled header file must have been produced by the same compiler
+binary as the current compilation is using.
@item
Any macros defined before the precompiled header is included must
either be defined in the same way as when the precompiled header was
generated, or must not affect the precompiled header, which usually
-means that the they don't appear in the precompiled header at all.
+means that they don't appear in the precompiled header at all.
The @option{-D} option is one way to define a macro before a
precompiled header is included; using a @code{#define} can also do it.
is to use exactly the same options when generating and using the
precompiled header. The following are known to be safe:
-@gccoptlist{-fpreprocessed -pedantic-errors}
+@gccoptlist{-fpreprocessed
+-fsched-interblock -fsched-spec -fsched-spec-load -fsched-spec-load-dangerous
+-fsched-verbose=<number> -fschedule-insns
+-pedantic-errors}
@end itemize
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