@c Copyright (C) 1988,1989,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,
-@c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+@c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
@c Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
from being defined in the @file{.h} file to being part of the
@code{targetm} structure.
+Similarly, there is a @code{targetcm} variable for hooks that are
+specific to front ends for C-family languages, documented as ``C
+Target Hook''. This is declared in @file{c-family/c-target.h}, the
+initializer @code{TARGETCM_INITIALIZER} in
+@file{c-family/c-target-def.h}. If targets initialize @code{targetcm}
+themselves, they should set @code{target_has_targetcm=yes} in
+@file{config.gcc}; otherwise a default definition is used.
+
+Similarly, there is a @code{targetm_common} variable for hooks that
+are shared between the compiler driver and the compilers proper,
+documented as ``Common Target Hook''. This is declared in
+@file{common/common-target.h}, the initializer
+@code{TARGETM_COMMON_INITIALIZER} in
+@file{common/common-target-def.h}. If targets initialize
+@code{targetm_common} themselves, they should set
+@code{target_has_targetm_common=yes} in @file{config.gcc}; otherwise a
+default definition is used.
+
@node Driver
@section Controlling the Compilation Driver, @file{gcc}
@cindex driver
removing duplicate search directories changes the linker's semantics.
@end defmac
+@hook TARGET_ALWAYS_STRIP_DOTDOT
+
@defmac MULTILIB_DEFAULTS
Define this macro as a C expression for the initializer of an array of
string to tell the driver program which options are defaults for this
Define this macro as a C string constant if you wish to override the
standard choice of @file{/usr/local/include} as the default prefix to
try when searching for local header files. @code{LOCAL_INCLUDE_DIR}
-comes before @code{SYSTEM_INCLUDE_DIR} in the search order.
+comes before @code{NATIVE_SYSTEM_HEADER_DIR} (set in
+@file{config.gcc}, normally @file{/usr/include}) in the search order.
Cross compilers do not search either @file{/usr/local/include} or its
replacement.
@end defmac
-@defmac SYSTEM_INCLUDE_DIR
-Define this macro as a C string constant if you wish to specify a
-system-specific directory to search for header files before the standard
-directory. @code{SYSTEM_INCLUDE_DIR} comes before
-@code{STANDARD_INCLUDE_DIR} in the search order.
-
-Cross compilers do not use this macro and do not search the directory
-specified.
-@end defmac
-
-@defmac STANDARD_INCLUDE_DIR
-Define this macro as a C string constant if you wish to override the
-standard choice of @file{/usr/include} as the default prefix to
-try when searching for header files.
-
-Cross compilers ignore this macro and do not search either
-@file{/usr/include} or its replacement.
-@end defmac
-
-@defmac STANDARD_INCLUDE_COMPONENT
-The ``component'' corresponding to @code{STANDARD_INCLUDE_DIR}.
+@defmac NATIVE_SYSTEM_HEADER_COMPONENT
+The ``component'' corresponding to @code{NATIVE_SYSTEM_HEADER_DIR}.
See @code{INCLUDE_DEFAULTS}, below, for the description of components.
If you do not define this macro, no component is used.
@end defmac
Define this macro if you wish to override the entire default search path
for include files. For a native compiler, the default search path
usually consists of @code{GCC_INCLUDE_DIR}, @code{LOCAL_INCLUDE_DIR},
-@code{SYSTEM_INCLUDE_DIR}, @code{GPLUSPLUS_INCLUDE_DIR}, and
-@code{STANDARD_INCLUDE_DIR}. In addition, @code{GPLUSPLUS_INCLUDE_DIR}
+@code{GPLUSPLUS_INCLUDE_DIR}, and
+@code{NATIVE_SYSTEM_HEADER_DIR}. In addition, @code{GPLUSPLUS_INCLUDE_DIR}
and @code{GCC_INCLUDE_DIR} are defined automatically by @file{Makefile},
and specify private search areas for GCC@. The directory
@code{GPLUSPLUS_INCLUDE_DIR} is used only for C++ programs.
@item
The environment variable @code{GCC_EXEC_PREFIX} or, if @code{GCC_EXEC_PREFIX}
-is not set and the compiler has not been installed in the configure-time
+is not set and the compiler has not been installed in the configure-time
@var{prefix}, the location in which the compiler has actually been installed.
@item
@item
The macro @code{STANDARD_EXEC_PREFIX}, if the compiler has been installed
-in the configured-time @var{prefix}.
+in the configured-time @var{prefix}.
@item
-The location @file{/usr/libexec/gcc/}, but only if this is a native compiler.
+The location @file{/usr/libexec/gcc/}, but only if this is a native compiler.
@item
-The location @file{/usr/lib/gcc/}, but only if this is a native compiler.
+The location @file{/usr/lib/gcc/}, but only if this is a native compiler.
@item
-The macro @code{MD_EXEC_PREFIX}, if defined, but only if this is a native
+The macro @code{MD_EXEC_PREFIX}, if defined, but only if this is a native
compiler.
@end enumerate
@item
The macro @code{STANDARD_EXEC_PREFIX}, but only if the toolchain is installed
-in the configured @var{prefix} or this is a native compiler.
+in the configured @var{prefix} or this is a native compiler.
@item
The location @file{/usr/lib/gcc/}, but only if this is a native compiler.
@item
-The macro @code{MD_EXEC_PREFIX}, if defined, but only if this is a native
+The macro @code{MD_EXEC_PREFIX}, if defined, but only if this is a native
compiler.
@item
-The macro @code{MD_STARTFILE_PREFIX}, if defined, but only if this is a
+The macro @code{MD_STARTFILE_PREFIX}, if defined, but only if this is a
native compiler, or we have a target system root.
@item
-The macro @code{MD_STARTFILE_PREFIX_1}, if defined, but only if this is a
+The macro @code{MD_STARTFILE_PREFIX_1}, if defined, but only if this is a
native compiler, or we have a target system root.
@item
@hook TARGET_OBJC_CONSTRUCT_STRING_OBJECT
-@hook TARGET_STRING_OBJECT_REF_TYPE_P
+@hook TARGET_OBJC_DECLARE_UNRESOLVED_CLASS_REFERENCE
-@hook TARGET_CHECK_STRING_OBJECT_FORMAT_ARG
+@hook TARGET_OBJC_DECLARE_CLASS_DEFINITION
-@defmac TARGET_VERSION
-This macro is a C statement to print on @code{stderr} a string
-describing the particular machine description choice. Every machine
-description should define @code{TARGET_VERSION}. For example:
+@hook TARGET_STRING_OBJECT_REF_TYPE_P
-@smallexample
-#ifdef MOTOROLA
-#define TARGET_VERSION \
- fprintf (stderr, " (68k, Motorola syntax)");
-#else
-#define TARGET_VERSION \
- fprintf (stderr, " (68k, MIT syntax)");
-#endif
-@end smallexample
-@end defmac
+@hook TARGET_CHECK_STRING_OBJECT_FORMAT_ARG
@hook TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE
This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}
@hook TARGET_OPTION_DEFAULT_PARAMS
-@hook TARGET_HELP
-This hook is called in response to the user invoking
-@option{--target-help} on the command line. It gives the target a
-chance to display extra information on the target specific command
-line options found in its @file{.opt} file.
-@end deftypefn
-
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
during compilation. For example, the MIPS target has one subtarget for
@defmac WORDS_BIG_ENDIAN
Define this macro to have the value 1 if, in a multiword object, the
most significant word has the lowest number. This applies to both
-memory locations and registers; GCC fundamentally assumes that the
-order of words in memory is the same as the order in registers. This
+memory locations and registers; see @code{REG_WORDS_BIG_ENDIAN} if the
+order of words in memory is not the same as the order in registers. This
macro need not be a constant.
@end defmac
+@defmac REG_WORDS_BIG_ENDIAN
+On some machines, the order of words in a multiword object differs between
+registers in memory. In such a situation, define this macro to describe
+the order of words in a register. The macro @code{WORDS_BIG_ENDIAN} controls
+the order of words in memory.
+@end defmac
+
@defmac FLOAT_WORDS_BIG_ENDIAN
Define this macro to have the value 1 if @code{DFmode}, @code{XFmode} or
@code{TFmode} floating point numbers are stored in memory with the word
then the hook should return the same mode as @code{promote_mode}, though
the signedness may be different.
+@var{type} can be NULL when promoting function arguments of libcalls.
+
The default is to not promote arguments and return values. You can
also define the hook to @code{default_promote_function_mode_always_promote}
if you would like to apply the same rules given by @code{PROMOTE_MODE}.
If the value of this macro has a type, it should be an unsigned type.
@end defmac
+@hook TARGET_VECTOR_ALIGNMENT
+
@defmac STACK_SLOT_ALIGNMENT (@var{type}, @var{mode}, @var{basic-align})
If defined, a C expression to compute the alignment for stack slot.
@var{type} is the data type, @var{mode} is the widest mode available,
is 128 then the default is 1, otherwise it is 0.
@end defmac
+@defmac LIBGCC2_GNU_PREFIX
+This macro corresponds to the @code{TARGET_LIBFUNC_GNU_PREFIX} target
+hook and should be defined if that hook is overriden to be true. It
+causes function names in libgcc to be changed to use a @code{__gnu_}
+prefix for their name rather than the default @code{__}. A port which
+uses this macro should also arrange to use @file{t-gnu-prefix} in
+the libgcc @file{config.host}.
+@end defmac
+
@defmac SF_SIZE
@defmacx DF_SIZE
@defmacx XF_SIZE
You can define such letters to correspond to various classes, then use
them in operand constraints.
+You must define the narrowest register classes for allocatable
+registers, so that each class either has no subclasses, or that for
+some mode, the move cost between registers within the class is
+cheaper than moving a register in the class to or from memory
+(@pxref{Costs}).
+
You should define a class for the union of two classes whenever some
instruction allows both classes. For example, if an instruction allows
either a floating point (coprocessor) register or a general register for a
certain operand, you should define a class @code{FLOAT_OR_GENERAL_REGS}
which includes both of them. Otherwise you will get suboptimal code,
or even internal compiler errors when reload cannot find a register in the
-the class computed via @code{reg_class_subunion}.
+class computed via @code{reg_class_subunion}.
You must also specify certain redundant information about the register
classes: for each class, which classes contain it and which ones are
addresses have different requirements than other base register uses.
@end defmac
-@defmac MODE_CODE_BASE_REG_CLASS (@var{mode}, @var{outer_code}, @var{index_code})
+@defmac MODE_CODE_BASE_REG_CLASS (@var{mode}, @var{address_space}, @var{outer_code}, @var{index_code})
A C expression whose value is the register class to which a valid
-base register must belong. @var{outer_code} and @var{index_code} define the
-context in which the base register occurs. @var{outer_code} is the code of
-the immediately enclosing expression (@code{MEM} for the top level of an
-address, @code{ADDRESS} for something that occurs in an
+base register for a memory reference in mode @var{mode} to address
+space @var{address_space} must belong. @var{outer_code} and @var{index_code}
+define the context in which the base register occurs. @var{outer_code} is
+the code of the immediately enclosing expression (@code{MEM} for the top level
+of an address, @code{ADDRESS} for something that occurs in an
@code{address_operand}). @var{index_code} is the code of the corresponding
index expression if @var{outer_code} is @code{PLUS}; @code{SCRATCH} otherwise.
@end defmac
@code{REGNO_MODE_CODE_OK_FOR_BASE_P}.
@end defmac
-@defmac REGNO_MODE_CODE_OK_FOR_BASE_P (@var{num}, @var{mode}, @var{outer_code}, @var{index_code})
-A C expression that is just like @code{REGNO_MODE_OK_FOR_BASE_P}, except
+@defmac REGNO_MODE_CODE_OK_FOR_BASE_P (@var{num}, @var{mode}, @var{address_space}, @var{outer_code}, @var{index_code})
+A C expression which is nonzero if register number @var{num} is
+suitable for use as a base register in operand addresses, accessing
+memory in mode @var{mode} in address space @var{address_space}.
+This is similar to @code{REGNO_MODE_OK_FOR_BASE_P}, except
that that expression may examine the context in which the register
appears in the memory reference. @var{outer_code} is the code of the
immediately enclosing expression (@code{MEM} if at the top level of the
register, so @code{TARGET_PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when
@var{x} is a floating-point constant. If the constant can't be loaded
into any kind of register, code generation will be better if
-@code{LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead
+@code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead
of using @code{TARGET_PREFERRED_RELOAD_CLASS}.
If an insn has pseudos in it after register allocation, reload will go
register, so @code{PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when
@var{x} is a floating-point constant. If the constant can't be loaded
into any kind of register, code generation will be better if
-@code{LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead
-of using @code{PREFERRED_RELOAD_CLASS}.
+@code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead
+of using @code{TARGET_PREFERRED_RELOAD_CLASS}.
If an insn has pseudos in it after register allocation, reload will go
through the alternatives and call repeatedly @code{PREFERRED_RELOAD_CLASS}
the SSE registers (and vice versa).
@end defmac
-@defmac PREFERRED_OUTPUT_RELOAD_CLASS (@var{x}, @var{class})
-Like @code{PREFERRED_RELOAD_CLASS}, but for output reloads instead of
-input reloads. If you don't define this macro, the default is to use
-@var{class}, unchanged.
-
-You can also use @code{PREFERRED_OUTPUT_RELOAD_CLASS} to discourage
-reload from using some alternatives, like @code{PREFERRED_RELOAD_CLASS}.
-@end defmac
-
@hook TARGET_PREFERRED_OUTPUT_RELOAD_CLASS
Like @code{TARGET_PREFERRED_RELOAD_CLASS}, but for output reloads instead of
input reloads.
allocation.
@end deftypefn
+@hook TARGET_CLASS_MAX_NREGS
+A target hook returns the maximum number of consecutive registers
+of class @var{rclass} needed to hold a value of mode @var{mode}.
+
+This is closely related to the macro @code{HARD_REGNO_NREGS}. In fact,
+the value returned by @code{TARGET_CLASS_MAX_NREGS (@var{rclass},
+@var{mode})} target hook should be the maximum value of
+@code{HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno}
+values in the class @var{rclass}.
+
+This target hook helps control the handling of multiple-word values
+in the reload pass.
+
+The default version of this target hook returns the size of @var{mode}
+in words.
+@end deftypefn
+
@defmac CLASS_MAX_NREGS (@var{class}, @var{mode})
A C expression for the maximum number of consecutive registers
of class @var{class} needed to hold a value of mode @var{mode}.
@end smallexample
@end defmac
-@hook TARGET_IRA_COVER_CLASSES
-Return an array of cover classes for the Integrated Register Allocator
-(@acronym{IRA}). Cover classes are a set of non-intersecting register
-classes covering all hard registers used for register allocation
-purposes. If a move between two registers in the same cover class is
-possible, it should be cheaper than a load or store of the registers.
-The array is terminated by a @code{LIM_REG_CLASSES} element.
-
-The order of cover classes in the array is important. If two classes
-have the same cost of usage for a pseudo, the class occurred first in
-the array is chosen for the pseudo.
-
-This hook is called once at compiler startup, after the command-line
-options have been processed. It is then re-examined by every call to
-@code{target_reinit}.
-
-The default implementation returns @code{IRA_COVER_CLASSES}, if defined,
-otherwise there is no default implementation. You must define either this
-macro or @code{IRA_COVER_CLASSES} in order to use the integrated register
-allocator with Chaitin-Briggs coloring. If the macro is not defined,
-the only available coloring algorithm is Chow's priority coloring.
-
-This hook must not be modified from @code{NULL} to non-@code{NULL} or
-vice versa by command-line option processing.
-@end deftypefn
-
-@defmac IRA_COVER_CLASSES
-See the documentation for @code{TARGET_IRA_COVER_CLASSES}.
-@end defmac
-
@node Old Constraints
@section Obsolete Macros for Defining Constraints
@cindex defining constraints, obsolete method
to be emitted.
@end defmac
-@defmac MD_UNWIND_SUPPORT
-A string specifying a file to be #include'd in unwind-dw2.c. The file
-so included typically defines @code{MD_FALLBACK_FRAME_STATE_FOR}.
-@end defmac
-
@defmac MD_FALLBACK_FRAME_STATE_FOR (@var{context}, @var{fs})
This macro allows the target to add CPU and operating system specific
code to the call-frame unwinder for use when there is no unwind data
@end defmac
+@defmac REG_VALUE_IN_UNWIND_CONTEXT
+
+Define this macro if the target stores register values as
+@code{_Unwind_Word} type in unwind context. It should be defined if
+target register size is larger than the size of @code{void *}. The
+default is to store register values as @code{void *} type.
+
+@end defmac
+
+@defmac ASSUME_EXTENDED_UNWIND_CONTEXT
+
+Define this macro to be 1 if the target always uses extended unwind
+context with version, args_size and by_value fields. If it is undefined,
+it will be defined to 1 when @code{REG_VALUE_IN_UNWIND_CONTEXT} is
+defined and 0 otherwise.
+
+@end defmac
+
@node Elimination
@subsection Eliminating Frame Pointer and Arg Pointer
types of arguments are passed in registers or how they are arranged in
the stack.
-@defmac FUNCTION_ARG (@var{cum}, @var{mode}, @var{type}, @var{named})
-A C expression that controls whether a function argument is passed
-in a register, and which register.
+@hook TARGET_FUNCTION_ARG
+Return an RTX indicating whether a function argument is passed in a
+register and if so, which register.
-The arguments are @var{cum}, which summarizes all the previous
+The arguments are @var{ca}, which summarizes all the previous
arguments; @var{mode}, the machine mode of the argument; @var{type},
the data type of the argument as a tree node or 0 if that is not known
(which happens for C support library functions); and @var{named},
-which is 1 for an ordinary argument and 0 for nameless arguments that
-correspond to @samp{@dots{}} in the called function's prototype.
-@var{type} can be an incomplete type if a syntax error has previously
-occurred.
+which is @code{true} for an ordinary argument and @code{false} for
+nameless arguments that correspond to @samp{@dots{}} in the called
+function's prototype. @var{type} can be an incomplete type if a
+syntax error has previously occurred.
-The value of the expression is usually either a @code{reg} RTX for the
-hard register in which to pass the argument, or zero to pass the
-argument on the stack.
-
-For machines like the VAX and 68000, where normally all arguments are
-pushed, zero suffices as a definition.
+The return value is usually either a @code{reg} RTX for the hard
+register in which to pass the argument, or zero to pass the argument
+on the stack.
The value of the expression can also be a @code{parallel} RTX@. This is
used when an argument is passed in multiple locations. The mode of the
RTX may have a first operand of zero. This indicates that the entire
argument is also stored on the stack.
-The last time this macro is called, it is called with @code{MODE ==
+The last time this hook is called, it is called with @code{MODE ==
VOIDmode}, and its result is passed to the @code{call} or @code{call_value}
pattern as operands 2 and 3 respectively.
@cindex @file{stdarg.h} and register arguments
-The usual way to make the ISO library @file{stdarg.h} work on a machine
-where some arguments are usually passed in registers, is to cause
-nameless arguments to be passed on the stack instead. This is done
-by making @code{FUNCTION_ARG} return 0 whenever @var{named} is 0.
-
-@cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{FUNCTION_ARG}
-@cindex @code{REG_PARM_STACK_SPACE}, and @code{FUNCTION_ARG}
+The usual way to make the ISO library @file{stdarg.h} work on a
+machine where some arguments are usually passed in registers, is to
+cause nameless arguments to be passed on the stack instead. This is
+done by making @code{TARGET_FUNCTION_ARG} return 0 whenever
+@var{named} is @code{false}.
+
+@cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{TARGET_FUNCTION_ARG}
+@cindex @code{REG_PARM_STACK_SPACE}, and @code{TARGET_FUNCTION_ARG}
You may use the hook @code{targetm.calls.must_pass_in_stack}
in the definition of this macro to determine if this argument is of a
type that must be passed in the stack. If @code{REG_PARM_STACK_SPACE}
-is not defined and @code{FUNCTION_ARG} returns nonzero for such an
+is not defined and @code{TARGET_FUNCTION_ARG} returns nonzero for such an
argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is
defined, the argument will be computed in the stack and then loaded into
a register.
-@end defmac
+@end deftypefn
@hook TARGET_MUST_PASS_IN_STACK
This target hook should return @code{true} if we should not pass @var{type}
documentation.
@end deftypefn
-@defmac FUNCTION_INCOMING_ARG (@var{cum}, @var{mode}, @var{type}, @var{named})
-Define this macro if the target machine has ``register windows'', so
+@hook TARGET_FUNCTION_INCOMING_ARG
+Define this hook if the target machine has ``register windows'', so
that the register in which a function sees an arguments is not
necessarily the same as the one in which the caller passed the
argument.
-For such machines, @code{FUNCTION_ARG} computes the register in which
-the caller passes the value, and @code{FUNCTION_INCOMING_ARG} should
-be defined in a similar fashion to tell the function being called
-where the arguments will arrive.
+For such machines, @code{TARGET_FUNCTION_ARG} computes the register in
+which the caller passes the value, and
+@code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar
+fashion to tell the function being called where the arguments will
+arrive.
-If @code{FUNCTION_INCOMING_ARG} is not defined, @code{FUNCTION_ARG}
-serves both purposes.
-@end defmac
+If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,
+@code{TARGET_FUNCTION_ARG} serves both purposes.
+@end deftypefn
@hook TARGET_ARG_PARTIAL_BYTES
This target hook returns the number of bytes at the beginning of an
in registers and the rest must be pushed. This macro tells the
compiler when this occurs, and how many bytes should go in registers.
-@code{FUNCTION_ARG} for these arguments should return the first
+@code{TARGET_FUNCTION_ARG} for these arguments should return the first
register to be used by the caller for this argument; likewise
-@code{FUNCTION_INCOMING_ARG}, for the called function.
+@code{TARGET_FUNCTION_INCOMING_ARG}, for the called function.
@end deftypefn
@hook TARGET_PASS_BY_REFERENCE
@end deftypefn
@defmac CUMULATIVE_ARGS
-A C type for declaring a variable that is used as the first argument of
-@code{FUNCTION_ARG} and other related values. For some target machines,
-the type @code{int} suffices and can hold the number of bytes of
-argument so far.
+A C type for declaring a variable that is used as the first argument
+of @code{TARGET_FUNCTION_ARG} and other related values. For some
+target machines, the type @code{int} suffices and can hold the number
+of bytes of argument so far.
There is no need to record in @code{CUMULATIVE_ARGS} anything about the
arguments that have been passed on the stack. The compiler has other
@c --mew 5feb93 i switched the order of the sentences. --mew 10feb93
@end defmac
-@defmac FUNCTION_ARG_ADVANCE (@var{cum}, @var{mode}, @var{type}, @var{named})
-A C statement (sans semicolon) to update the summarizer variable
-@var{cum} to advance past an argument in the argument list. The
-values @var{mode}, @var{type} and @var{named} describe that argument.
-Once this is done, the variable @var{cum} is suitable for analyzing
-the @emph{following} argument with @code{FUNCTION_ARG}, etc.
+@hook TARGET_FUNCTION_ARG_ADVANCE
+This hook updates the summarizer variable pointed to by @var{ca} to
+advance past an argument in the argument list. The values @var{mode},
+@var{type} and @var{named} describe that argument. Once this is done,
+the variable @var{cum} is suitable for analyzing the @emph{following}
+argument with @code{TARGET_FUNCTION_ARG}, etc.
-This macro need not do anything if the argument in question was passed
+This hook need not do anything if the argument in question was passed
on the stack. The compiler knows how to track the amount of stack space
used for arguments without any special help.
-@end defmac
+@end deftypefn
@defmac FUNCTION_ARG_OFFSET (@var{mode}, @var{type})
If defined, a C expression that is the number of bytes to add to the
@code{enum direction}: either @code{upward} to pad above the argument,
@code{downward} to pad below, or @code{none} to inhibit padding.
-The @emph{amount} of padding is always just enough to reach the next
-multiple of @code{TARGET_FUNCTION_ARG_BOUNDARY}; this macro does not
-control it.
+The @emph{amount} of padding is not controlled by this macro, but by the
+target hook @code{TARGET_FUNCTION_ARG_ROUND_BOUNDARY}. It is
+always just enough to reach the next multiple of that boundary.
This macro has a default definition which is right for most systems.
For little-endian machines, the default is to pad upward. For
@code{PARM_BOUNDARY} for all arguments.
@end deftypefn
+@hook TARGET_FUNCTION_ARG_ROUND_BOUNDARY
+
@defmac FUNCTION_ARG_REGNO_P (@var{regno})
A C expression that is nonzero if @var{regno} is the number of a hard
register in which function arguments are sometimes passed. This does
must have move patterns for this mode.
@end deftypefn
+@hook TARGET_ARRAY_MODE_SUPPORTED_P
+
@hook TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P
Define this to return nonzero for machine modes for which the port has
small register classes. If this target hook returns nonzero for a given
place regardless of mode.) The value of the expression is usually a
@code{reg} RTX for the hard register where the return value is stored.
The value can also be a @code{parallel} RTX, if the return value is in
-multiple places. See @code{FUNCTION_ARG} for an explanation of the
+multiple places. See @code{TARGET_FUNCTION_ARG} for an explanation of the
@code{parallel} form. Note that the callee will populate every
location specified in the @code{parallel}, but if the first element of
the @code{parallel} contains the whole return value, callers will use
@hook TARGET_LIBCALL_VALUE
Define this hook if the back-end needs to know the name of the libcall
-function in order to determine where the result should be returned.
+function in order to determine where the result should be returned.
The mode of the result is given by @var{mode} and the name of the called
-library function is given by @var{fun}. The hook should return an RTX
+library function is given by @var{fun}. The hook should return an RTX
representing the place where the library function result will be returned.
If this hook is not defined, then LIBCALL_VALUE will be used.
FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.
@end deftypefn
+@hook TARGET_SET_UP_BY_PROLOGUE
+
@node Stack Smashing Protection
@subsection Stack smashing protection
@cindex stack smashing protection
Define this hook to return @code{true} if the location where a function
argument is passed depends on whether or not it is a named argument.
-This hook controls how the @var{named} argument to @code{FUNCTION_ARG}
+This hook controls how the @var{named} argument to @code{TARGET_FUNCTION_ARG}
is set for varargs and stdarg functions. If this hook returns
@code{true}, the @var{named} argument is always true for named
arguments, and false for unnamed arguments. If it returns @code{false},
If the target defines @code{TARGET_ASM_TRAMPOLINE_TEMPLATE}, then the
first thing this hook should do is emit a block move into @var{m_tramp}
from the memory block returned by @code{assemble_trampoline_template}.
-Note that the block move need only cover the constant parts of the
+Note that the block move need only cover the constant parts of the
trampoline. If the target isolates the variable parts of the trampoline
to the end, not all @code{TRAMPOLINE_SIZE} bytes need be copied.
If the target requires any other actions, such as flushing caches or
-enabling stack execution, these actions should be performed after
+enabling stack execution, these actions should be performed after
initializing the trampoline proper.
@end deftypefn
@var{end} are both pointer expressions.
@end defmac
-The operating system may also require the stack to be made executable
-before calling the trampoline. To implement this requirement, define
-the following macro.
-
-@defmac ENABLE_EXECUTE_STACK
-Define this macro if certain operations must be performed before executing
-code located on the stack. The macro should expand to a series of C
-file-scope constructs (e.g.@: functions) and provide a unique entry point
-named @code{__enable_execute_stack}. The target is responsible for
-emitting calls to the entry point in the code, for example from the
-@code{TARGET_TRAMPOLINE_INIT} hook.
-@end defmac
-
To use a standard subroutine, define the following macro. In addition,
you must make sure that the instructions in a trampoline fill an entire
cache line with identical instructions, or else ensure that the
The default is to do nothing. Most ports don't need to define this hook.
@end deftypefn
+@hook TARGET_LIBFUNC_GNU_PREFIX
+
@defmac FLOAT_LIB_COMPARE_RETURNS_BOOL (@var{mode}, @var{comparison})
This macro should return @code{true} if the library routine that
implements the floating point comparison operator @var{comparison} in
@end defmac
@defmac NEXT_OBJC_RUNTIME
-Define this macro to generate code for Objective-C message sending using
-the calling convention of the NeXT system. This calling convention
-involves passing the object, the selector and the method arguments all
-at once to the method-lookup library function.
+Set this macro to 1 to use the "NeXT" Objective-C message sending conventions
+by default. This calling convention involves passing the object, the selector
+and the method arguments all at once to the method-lookup library function.
+This is the usual setting when targeting Darwin/Mac OS X systems, which have
+the NeXT runtime installed.
+
+If the macro is set to 0, the "GNU" Objective-C message sending convention
+will be used by default. This convention passes just the object and the
+selector to the method-lookup function, which returns a pointer to the method.
-The default calling convention passes just the object and the selector
-to the lookup function, which returns a pointer to the method.
+In either case, it remains possible to select code-generation for the alternate
+scheme, by means of compiler command line switches.
@end defmac
@node Addressing Modes
is a valid address. On most machines the default definition of
@code{(CONSTANT_P (@var{x}) && GET_CODE (@var{x}) != CONST_DOUBLE)}
is acceptable, but a few machines are more restrictive as to which
-constant addresses are supported.
+constant addresses are supported.
@end defmac
@defmac CONSTANT_P (@var{x})
@code{TARGET_MODE_DEPENDENT_ADDRESS_P} target hook.
@end defmac
-@defmac LEGITIMATE_CONSTANT_P (@var{x})
-A C expression that is nonzero if @var{x} is a legitimate constant for
-an immediate operand on the target machine. You can assume that
-@var{x} satisfies @code{CONSTANT_P}, so you need not check this. In fact,
-@samp{1} is a suitable definition for this macro on machines where
-anything @code{CONSTANT_P} is valid.
-@end defmac
+@hook TARGET_LEGITIMATE_CONSTANT_P
+This hook returns true if @var{x} is a legitimate constant for a
+@var{mode}-mode immediate operand on the target machine. You can assume that
+@var{x} satisfies @code{CONSTANT_P}, so you need not check this.
+
+The default definition returns true.
+@end deftypefn
@hook TARGET_DELEGITIMIZE_ADDRESS
This hook is used to undo the possibly obfuscating effects of the
into their original form.
@end deftypefn
+@hook TARGET_CONST_NOT_OK_FOR_DEBUG_P
+This hook should return true if @var{x} should not be emitted into
+debug sections.
+@end deftypefn
+
@hook TARGET_CANNOT_FORCE_CONST_MEM
This hook should return true if @var{x} is of a form that cannot (or
-should not) be spilled to the constant pool. The default version of
-this hook returns false.
+should not) be spilled to the constant pool. @var{mode} is the mode
+of @var{x}.
+
+The default version of this hook returns false.
The primary reason to define this hook is to prevent reload from
deciding that a non-legitimate constant would be better reloaded
@hook TARGET_VECTORIZE_BUILTIN_VECTORIZATION_COST
Returns cost of different scalar or vector statements for vectorization cost model.
-For vector memory operations the cost may depend on type (@var{vectype}) and
+For vector memory operations the cost may depend on type (@var{vectype}) and
misalignment value (@var{misalign}).
@end deftypefn
Return true if vector alignment is reachable (by peeling N iterations) for the given type.
@end deftypefn
-@hook TARGET_VECTORIZE_BUILTIN_VEC_PERM
-Target builtin that implements vector permute.
-@end deftypefn
-
-@hook TARGET_VECTORIZE_BUILTIN_VEC_PERM_OK
-Return true if a vector created for @code{builtin_vec_perm} is valid.
+@hook TARGET_VECTORIZE_VEC_PERM_CONST_OK
+Return true if a vector created for @code{vec_perm_const} is valid.
@end deftypefn
@hook TARGET_VECTORIZE_BUILTIN_CONVERSION
The default is zero which means to not iterate over other vector sizes.
@end deftypefn
+@hook TARGET_VECTORIZE_BUILTIN_TM_LOAD
+
+@hook TARGET_VECTORIZE_BUILTIN_TM_STORE
+
+@hook TARGET_VECTORIZE_BUILTIN_GATHER
+Target builtin that implements vector gather operation. @var{mem_vectype}
+is the vector type of the load and @var{index_type} is scalar type of
+the index, scaled by @var{scale}.
+The default is @code{NULL_TREE} which means to not vectorize gather
+loads.
+@end deftypefn
+
@node Anchored Addresses
@section Anchored Addresses
@cindex anchored addresses
@defmac SET_RATIO (@var{speed})
The threshold of number of scalar move insns, @emph{below} which a sequence
of insns should be generated to set memory to a constant value, instead of
-a block set insn or a library call.
+a block set insn or a library call.
Increasing the value will always make code faster, but
eventually incurs high cost in increased code size.
@defmac SET_BY_PIECES_P (@var{size}, @var{alignment})
A C expression used to determine whether @code{store_by_pieces} will be
-used to set a chunk of memory to a constant value, or whether some
-other mechanism will be used. Used by @code{__builtin_memset} when
+used to set a chunk of memory to a constant value, or whether some
+other mechanism will be used. Used by @code{__builtin_memset} when
storing values other than constant zero.
Defaults to 1 if @code{move_by_pieces_ninsns} returns less
than @code{SET_RATIO}.
This target hook describes the relative costs of RTL expressions.
The cost may depend on the precise form of the expression, which is
-available for examination in @var{x}, and the rtx code of the expression
-in which it is contained, found in @var{outer_code}. @var{code} is the
-expression code---redundant, since it can be obtained with
-@code{GET_CODE (@var{x})}.
+available for examination in @var{x}, and the fact that @var{x} appears
+as operand @var{opno} of an expression with rtx code @var{outer_code}.
+That is, the hook can assume that there is some rtx @var{y} such
+that @samp{GET_CODE (@var{y}) == @var{outer_code}} and such that
+either (a) @samp{XEXP (@var{y}, @var{opno}) == @var{x}} or
+(b) @samp{XVEC (@var{y}, @var{opno})} contains @var{x}.
+
+@var{code} is @var{x}'s expression code---redundant, since it can be
+obtained with @code{GET_CODE (@var{x})}.
In implementing this hook, you can use the construct
@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast
in its second parameter.
@end deftypefn
+@hook TARGET_SCHED_EXPOSED_PIPELINE
+
+@hook TARGET_SCHED_REASSOCIATION_WIDTH
+
@node Sections
@section Dividing the Output into Sections (Texts, Data, @dots{})
@c the above section title is WAY too long. maybe cut the part between
@defmac BSS_SECTION_ASM_OP
If defined, a C expression whose value is a string, including spacing,
containing the assembler operation to identify the following data as
-uninitialized global data. If not defined, and neither
-@code{ASM_OUTPUT_BSS} nor @code{ASM_OUTPUT_ALIGNED_BSS} are defined,
+uninitialized global data. If not defined, and
+@code{ASM_OUTPUT_ALIGNED_BSS} not defined,
uninitialized global data will be output in the data section if
@option{-fno-common} is passed, otherwise @code{ASM_OUTPUT_COMMON} will be
used.
otherwise.
@end deftypefn
+@hook TARGET_ASM_MERGEABLE_RODATA_PREFIX
+
+@hook TARGET_ASM_TM_CLONE_TABLE_SECTION
+
@hook TARGET_ASM_SELECT_RTX_SECTION
Return the section into which a constant @var{x}, of mode @var{mode},
should be placed. You can assume that @var{x} is some kind of
when the source operand contains a symbolic address. You may also
need to alter the handling of switch statements so that they use
relative addresses.
-@c i rearranged the order of the macros above to try to force one of
+@c i rearranged the order of the macros above to try to force one of
@c them to the next line, to eliminate an overfull hbox. --mew 10feb93
@defmac PIC_OFFSET_TABLE_REGNUM
@hook TARGET_ASM_FUNCTION_SECTION
Return preferred text (sub)section for function @var{decl}.
Main purpose of this function is to separate cold, normal and hot
-functions. @var{startup} is true when function is known to be used only
+functions. @var{startup} is true when function is known to be used only
at startup (from static constructors or it is @code{main()}).
@var{exit} is true when function is known to be used only at exit
(from static destructors).
return @code{true}.
@end deftypefn
-@defmac OUTPUT_ADDR_CONST_EXTRA (@var{stream}, @var{x}, @var{fail})
-A C statement to recognize @var{rtx} patterns that
-@code{output_addr_const} can't deal with, and output assembly code to
-@var{stream} corresponding to the pattern @var{x}. This may be used to
-allow machine-dependent @code{UNSPEC}s to appear within constants.
-
-If @code{OUTPUT_ADDR_CONST_EXTRA} fails to recognize a pattern, it must
-@code{goto fail}, so that a standard error message is printed. If it
-prints an error message itself, by calling, for example,
-@code{output_operand_lossage}, it may just complete normally.
-@end defmac
-
@defmac ASM_OUTPUT_ASCII (@var{stream}, @var{ptr}, @var{len})
A C statement to output to the stdio stream @var{stream} an assembler
instruction to assemble a string constant containing the @var{len}
the variable's decl in order to chose what to output.
@end defmac
-@defmac ASM_OUTPUT_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{rounded})
+@defmac ASM_OUTPUT_ALIGNED_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment})
A C statement (sans semicolon) to output to the stdio stream
@var{stream} the assembler definition of uninitialized global @var{decl} named
-@var{name} whose size is @var{size} bytes. The variable @var{rounded}
-is the size rounded up to whatever alignment the caller wants.
+@var{name} whose size is @var{size} bytes. The variable @var{alignment}
+is the alignment specified as the number of bits.
-Try to use function @code{asm_output_bss} defined in @file{varasm.c} when
-defining this macro. If unable, use the expression
+Try to use function @code{asm_output_aligned_bss} defined in file
+@file{varasm.c} when defining this macro. If unable, use the expression
@code{assemble_name (@var{stream}, @var{name})} to output the name itself;
before and after that, output the additional assembler syntax for defining
the name, and a newline.
-There are two ways of handling global BSS@. One is to define either
-this macro or its aligned counterpart, @code{ASM_OUTPUT_ALIGNED_BSS}.
+There are two ways of handling global BSS@. One is to define this macro.
The other is to have @code{TARGET_ASM_SELECT_SECTION} return a
switchable BSS section (@pxref{TARGET_HAVE_SWITCHABLE_BSS_SECTIONS}).
You do not need to do both.
common in order to save space in the object file.
@end defmac
-@defmac ASM_OUTPUT_ALIGNED_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment})
-Like @code{ASM_OUTPUT_BSS} except takes the required alignment as a
-separate, explicit argument. If you define this macro, it is used in
-place of @code{ASM_OUTPUT_BSS}, and gives you more flexibility in
-handling the required alignment of the variable. The alignment is specified
-as the number of bits.
-
-Try to use function @code{asm_output_aligned_bss} defined in file
-@file{varasm.c} when defining this macro.
-@end defmac
-
@defmac ASM_OUTPUT_LOCAL (@var{stream}, @var{name}, @var{size}, @var{rounded})
A C statement (sans semicolon) to output to the stdio stream
@var{stream} the assembler definition of a local-common-label named
macro to provide more human-readable names.
@end defmac
-@defmac ASM_DECLARE_CLASS_REFERENCE (@var{stream}, @var{name})
-A C statement (sans semicolon) to output to the stdio stream
-@var{stream} commands to declare that the label @var{name} is an
-Objective-C class reference. This is only needed for targets whose
-linkers have special support for NeXT-style runtimes.
-@end defmac
-
-@defmac ASM_DECLARE_UNRESOLVED_REFERENCE (@var{stream}, @var{name})
-A C statement (sans semicolon) to output to the stdio stream
-@var{stream} commands to declare that the label @var{name} is an
-unresolved Objective-C class reference. This is only needed for targets
-whose linkers have special support for NeXT-style runtimes.
-@end defmac
-
@node Initialization
@subsection How Initialization Functions Are Handled
@cindex initialization routines
@hook TARGET_WANT_DEBUG_PUB_SECTIONS
+@hook TARGET_FORCE_AT_COMP_DIR
+
+@hook TARGET_DELAY_SCHED2
+
+@hook TARGET_DELAY_VARTRACK
+
@defmac ASM_OUTPUT_DWARF_DELTA (@var{stream}, @var{size}, @var{label1}, @var{label2})
A C statement to issue assembly directives that create a difference
@var{lab1} minus @var{lab2}, using an integer of the given @var{size}.
value is the same as for @code{TARGET_PCH_VALID_P}.
@end deftypefn
+@hook TARGET_PREPARE_PCH_SAVE
+
@node C++ ABI
@section C++ ABI parameters
@cindex parameters, c++ abi
@defmac CLZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value})
@defmacx CTZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value})
A C expression that indicates whether the architecture defines a value
-for @code{clz} or @code{ctz} with a zero operand.
+for @code{clz} or @code{ctz} with a zero operand.
A result of @code{0} indicates the value is undefined.
If the value is defined for only the RTL expression, the macro should
evaluate to @code{1}; if the value applies also to the corresponding optab
entry (which is normally the case if it expands directly into
-the corresponding RTL), then the macro should evaluate to @code{2}.
+the corresponding RTL), then the macro should evaluate to @code{2}.
In the cases where the value is defined, @var{value} should be set to
-this value.
+this value.
If this macro is not defined, the value of @code{clz} or
@code{ctz} at zero is assumed to be undefined.
@defmac FUNCTION_MODE
An alias for the machine mode used for memory references to functions
being called, in @code{call} RTL expressions. On most CISC machines,
-where an instruction can begin at any byte address, this should be
+where an instruction can begin at any byte address, this should be
@code{QImode}. On most RISC machines, where all instructions have fixed
size and alignment, this should be a mode with the same size and alignment
as the machine instruction words - typically @code{SImode} or @code{HImode}.
To create a built-in function, call the function
@code{lang_hooks.builtin_function}
which is defined by the language front end. You can use any type nodes set
-up by @code{build_common_tree_nodes} and @code{build_common_tree_nodes_2};
+up by @code{build_common_tree_nodes};
only language front ends that use those two functions will call
@samp{TARGET_INIT_BUILTINS}.
@end deftypefn
@end deftypefn
@hook TARGET_SET_CURRENT_FUNCTION
-The compiler invokes this hook whenever it changes its current function
+The compiler invokes this hook whenever it changes its current function
context (@code{cfun}). You can define this function if
the back end needs to perform any initialization or reset actions on a
per-function basis. For example, it may be used to implement function
@hook TARGET_INVALID_PARAMETER_TYPE
If defined, this macro returns the diagnostic message when it is
-invalid for functions to include parameters of type @var{type},
+invalid for functions to include parameters of type @var{type},
or @code{NULL} if validity should be determined by
the front end. This is currently used only by the C and C++ front ends.
@end deftypefn
@hook TARGET_INVALID_RETURN_TYPE
If defined, this macro returns the diagnostic message when it is
-invalid for functions to have return type @var{type},
+invalid for functions to have return type @var{type},
or @code{NULL} if validity should be determined by
the front end. This is currently used only by the C and C++ front ends.
@end deftypefn
@hook TARGET_PROMOTED_TYPE
-If defined, this target hook returns the type to which values of
-@var{type} should be promoted when they appear in expressions,
+If defined, this target hook returns the type to which values of
+@var{type} should be promoted when they appear in expressions,
analogous to the integer promotions, or @code{NULL_TREE} to use the
front end's normal promotion rules. This hook is useful when there are
target-specific types with special promotion rules.
@end deftypefn
@hook TARGET_CONVERT_TO_TYPE
-If defined, this hook returns the result of converting @var{expr} to
-@var{type}. It should return the converted expression,
+If defined, this hook returns the result of converting @var{expr} to
+@var{type}. It should return the converted expression,
or @code{NULL_TREE} to apply the front end's normal conversion rules.
-This hook is useful when there are target-specific types with special
+This hook is useful when there are target-specific types with special
conversion rules.
This is currently used only by the C and C++ front ends.
@end deftypefn
@defmac LIBGCC2_UNWIND_ATTRIBUTE
Define this macro if any target-specific attributes need to be attached
-to the functions in @file{libgcc} that provide low-level support for
+to the functions in @file{libgcc} that provide low-level support for
call stack unwinding. It is used in declarations in @file{unwind-generic.h}
and the associated definitions of those functions.
@end defmac
MIPS, where add-immediate takes a 16-bit signed value,
@code{TARGET_CONST_ANCHOR} is set to @samp{0x8000}. The default value
is zero, which disables this optimization. @end deftypevr
+
+@hook TARGET_ATOMIC_TEST_AND_SET_TRUEVAL
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