@c Copyright (C) 1988,1989,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,
-@c 2002, 2003, 2004 Free Software Foundation, Inc.
+@c 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
* Per-Function Data:: Defining data structures for per-function information.
* Storage Layout:: Defining sizes and alignments of data.
* Type Layout:: Defining sizes and properties of basic user data types.
-* Escape Sequences:: Defining the value of target character escape sequences
* Registers:: Naming and describing the hardware registers.
* Register Classes:: Defining the classes of hardware registers.
* Stack and Calling:: Defining which way the stack grows and by how much.
line, but, unlike @code{LIBGCC_SPEC}, it is used unmodified.
@end defmac
+@defmac USE_LD_AS_NEEDED
+A macro that controls the modifications to @code{LIBGCC_SPEC}
+mentioned in @code{REAL_LIBGCC_SPEC}. If nonzero, a spec will be
+generated that uses --as-needed and the shared libgcc in place of the
+static exception handler library, when linking without any of
+@code{-static}, @code{-static-libgcc}, or @code{-shared-libgcc}.
+@end defmac
+
+@defmac LINK_EH_SPEC
+If defined, this C string constant is added to @code{LINK_SPEC}.
+When @code{USE_LD_AS_NEEDED} is zero or undefined, it also affects
+the modifications to @code{LIBGCC_SPEC} mentioned in
+@code{REAL_LIBGCC_SPEC}.
+@end defmac
+
@defmac STARTFILE_SPEC
Another C string constant used much like @code{LINK_SPEC}. The
difference between the two is that @code{STARTFILE_SPEC} is used at
@end smallexample
@end defmac
-@defmac LINK_LIBGCC_SPECIAL
-Define this macro if the driver program should find the library
-@file{libgcc.a} itself and should not pass @option{-L} options to the
-linker. If you do not define this macro, the driver program will pass
-the argument @option{-lgcc} to tell the linker to do the search and will
-pass @option{-L} options to it.
-@end defmac
-
@defmac LINK_LIBGCC_SPECIAL_1
Define this macro if the driver program should find the library
@file{libgcc.a}. If you do not define this macro, the driver program will pass
the argument @option{-lgcc} to tell the linker to do the search.
-This macro is similar to @code{LINK_LIBGCC_SPECIAL}, except that it does
-not affect @option{-L} options.
@end defmac
@defmac LINK_GCC_C_SEQUENCE_SPEC
@end defmac
@deftypevar {extern int} target_flags
-This declaration should be present.
+This variable is declared in @file{options.h}, which is included before
+any target-specific headers.
+@end deftypevar
+
+@deftypevar {Target Hook} int TARGET_DEFAULT_TARGET_FLAGS
+This variable specifies the initial value of @code{target_flags}.
+Its default setting is 0.
@end deftypevar
@cindex optional hardware or system features
@cindex features, optional, in system conventions
-@defmac TARGET_@var{featurename}
-This series of macros is to allow compiler command arguments to
-enable or disable the use of optional features of the target machine.
-For example, one machine description serves both the 68000 and
-the 68020; a command argument tells the compiler whether it should
-use 68020-only instructions or not. This command argument works
-by means of a macro @code{TARGET_68020} that tests a bit in
-@code{target_flags}.
-
-Define a macro @code{TARGET_@var{featurename}} for each such option.
-Its definition should test a bit in @code{target_flags}. It is
-recommended that a helper macro @code{MASK_@var{featurename}}
-is defined for each bit-value to test, and used in
-@code{TARGET_@var{featurename}} and @code{TARGET_SWITCHES}. For
-example:
-
-@smallexample
-#define TARGET_MASK_68020 1
-#define TARGET_68020 (target_flags & MASK_68020)
-@end smallexample
-
-One place where these macros are used is in the condition-expressions
-of instruction patterns. Note how @code{TARGET_68020} appears
-frequently in the 68000 machine description file, @file{m68k.md}.
-Another place they are used is in the definitions of the other
-macros in the @file{@var{machine}.h} file.
-@end defmac
-
-@defmac TARGET_SWITCHES
-This macro defines names of command options to set and clear
-bits in @code{target_flags}. Its definition is an initializer
-with a subgrouping for each command option.
-
-Each subgrouping contains a string constant, that defines the option
-name, a number, which contains the bits to set in
-@code{target_flags}, and a second string which is the description
-displayed by @option{--help}. If the number is negative then the bits specified
-by the number are cleared instead of being set. If the description
-string is present but empty, then no help information will be displayed
-for that option, but it will not count as an undocumented option. The
-actual option name is made by appending @samp{-m} to the specified name.
-Non-empty description strings should be marked with @code{N_(@dots{})} for
-@command{xgettext}. Please do not mark empty strings because the empty
-string is reserved by GNU gettext. @code{gettext("")} returns the header entry
-of the message catalog with meta information, not the empty string.
-
-In addition to the description for @option{--help},
-more detailed documentation for each option should be added to
-@file{invoke.texi}.
-
-One of the subgroupings should have a null string. The number in
-this grouping is the default value for @code{target_flags}. Any
-target options act starting with that value.
-
-Here is an example which defines @option{-m68000} and @option{-m68020}
-with opposite meanings, and picks the latter as the default:
-
-@smallexample
-#define TARGET_SWITCHES \
- @{ @{ "68020", MASK_68020, "" @}, \
- @{ "68000", -MASK_68020, \
- N_("Compile for the 68000") @}, \
- @{ "", MASK_68020, "" @}, \
- @}
-@end smallexample
-@end defmac
-
-@defmac TARGET_OPTIONS
-This macro is similar to @code{TARGET_SWITCHES} but defines names of command
-options that have values. Its definition is an initializer with a
-subgrouping for each command option.
-
-Each subgrouping contains a string constant, that defines the option
-name, the address of a variable, a description string, and a value.
-Non-empty description strings should be marked with @code{N_(@dots{})}
-for @command{xgettext}. Please do not mark empty strings because the
-empty string is reserved by GNU gettext. @code{gettext("")} returns the
-header entry of the message catalog with meta information, not the empty
-string.
-
-If the value listed in the table is @code{NULL}, then the variable, type
-@code{char *}, is set to the variable part of the given option if the
-fixed part matches. In other words, if the first part of the option
-matches what's in the table, the variable will be set to point to the
-rest of the option. This allows the user to specify a value for that
-option. The actual option name is made by appending @samp{-m} to the
-specified name. Again, each option should also be documented in
-@file{invoke.texi}.
-
-If the value listed in the table is non-@code{NULL}, then the option
-must match the option in the table exactly (with @samp{-m}), and the
-variable is set to point to the value listed in the table.
-
-Here is an example which defines @option{-mshort-data-@var{number}}. If the
-given option is @option{-mshort-data-512}, the variable @code{m88k_short_data}
-will be set to the string @code{"512"}.
-
-@smallexample
-extern char *m88k_short_data;
-#define TARGET_OPTIONS \
- @{ @{ "short-data-", &m88k_short_data, \
- N_("Specify the size of the short data section"), 0 @} @}
-@end smallexample
-
-Here is a variant of the above that allows the user to also specify
-just @option{-mshort-data} where a default of @code{"64"} is used.
-
-@smallexample
-extern char *m88k_short_data;
-#define TARGET_OPTIONS \
- @{ @{ "short-data-", &m88k_short_data, \
- N_("Specify the size of the short data section"), 0 @} \
- @{ "short-data", &m88k_short_data, "", "64" @},
- @}
-@end smallexample
-
-Here is an example which defines @option{-mno-alu}, @option{-malu1}, and
-@option{-malu2} as a three-state switch, along with suitable macros for
-checking the state of the option (documentation is elided for brevity).
-
-@smallexample
-[chip.c]
-char *chip_alu = ""; /* Specify default here. */
-
-[chip.h]
-extern char *chip_alu;
-#define TARGET_OPTIONS \
- @{ @{ "no-alu", &chip_alu, "", "" @}, \
- @{ "alu1", &chip_alu, "", "1" @}, \
- @{ "alu2", &chip_alu, "", "2" @}, @}
-#define TARGET_ALU (chip_alu[0] != '\0')
-#define TARGET_ALU1 (chip_alu[0] == '1')
-#define TARGET_ALU2 (chip_alu[0] == '2')
-@end smallexample
-@end defmac
+@deftypefn {Target Hook} bool TARGET_HANDLE_OPTION (size_t @var{code}, const char *@var{arg}, int @var{value})
+This hook is called whenever the user specifies one of the
+target-specific options described by the @file{.opt} definition files
+(@pxref{Options}). It has the opportunity to do some option-specific
+processing and should return true if the option is valid. The default
+definition does nothing but return true.
+
+@var{code} specifies the @code{OPT_@var{name}} enumeration value
+associated with the selected option; @var{name} is just a rendering of
+the option name in which non-alphanumeric characters are replaced by
+underscores. @var{arg} specifies the string argument and is null if
+no argument was given. If the option is flagged as a @code{UInteger}
+(@pxref{Option properties}), @var{value} is the numeric value of the
+argument. Otherwise @var{value} is 1 if the positive form of the
+option was used and 0 if the ``no-'' form was.
+@end deftypefn
@defmac TARGET_VERSION
This macro is a C statement to print on @code{stderr} a string
@code{struct function} structure. It is intended that this would be
used to initialize the @code{machine} of that structure.
-@code{struct machine_function} structures are expected to be freed by GC.
+@code{struct machine_function} structures are expected to be freed by GC@.
Generally, any memory that they reference must be allocated by using
@code{ggc_alloc}, including the structure itself.
@end deftypevar
@end defmac
@defmac UNITS_PER_WORD
-Number of storage units in a word; normally 4.
+Number of storage units in a word; normally the size of a general-purpose
+register, a power of two from 1 or 8.
@end defmac
@defmac MIN_UNITS_PER_WORD
smallest value that @code{UNITS_PER_WORD} can have at run-time.
@end defmac
+@defmac UNITS_PER_SIMD_WORD
+Number of units in the vectors that the vectorizer can produce.
+The default is equal to @code{UNITS_PER_WORD}, because the vectorizer
+can do some transformations even in absence of specialized @acronym{SIMD}
+hardware.
+@end defmac
+
@defmac POINTER_SIZE
Width of a pointer, in bits. You must specify a value no wider than the
width of @code{Pmode}. If it is not equal to the width of @code{Pmode},
functions.
If this target hook returns @code{true}, @code{FUNCTION_VALUE} must
-perform the same promotions done by @code{PROMOTE_FUNCTON_MODE}.
+perform the same promotions done by @code{PROMOTE_FUNCTION_MODE}.
@end deftypefn
@defmac PARM_BOUNDARY
of the underlying type is used by one or more same-size adjacent
bit-fields (that is, if its long:3, 32 bits is used in the record,
and any additional adjacent long bit-fields are packed into the same
-chunk of 32 bits. However, if the size changes, a new field of that
-size is allocated). In an unpacked record, this is the same as using
+chunk of 32 bits. However, if the size changes, a new field of that
+size is allocated). In an unpacked record, this is the same as using
alignment, but not equivalent when packing.
If both MS bit-fields and @samp{__attribute__((packed))} are used,
-the latter will take precedence. If @samp{__attribute__((packed))} is
+the latter will take precedence. If @samp{__attribute__((packed))} is
used on a single field when MS bit-fields are in use, it will take
precedence for that field, but the alignment of the rest of the structure
may affect its placement.
@defmac ADA_LONG_TYPE_SIZE
On some machines, the size used for the Ada equivalent of the type
-@code{long} by a native Ada compiler differs from that used by C. In
+@code{long} by a native Ada compiler differs from that used by C@. In
that situation, define this macro to be a C expression to be used for
the size of that type. If you don't define this, the default is the
value of @code{LONG_TYPE_SIZE}.
words.
@end defmac
+@defmac LIBGCC2_LONG_DOUBLE_TYPE_SIZE
+Define this macro if @code{LONG_DOUBLE_TYPE_SIZE} is not constant or
+if you want routines in @file{libgcc2.a} for a size other than
+@code{LONG_DOUBLE_TYPE_SIZE}. If you don't define this, the
+default is @code{LONG_DOUBLE_TYPE_SIZE}.
+@end defmac
+
+@defmac LIBGCC2_HAS_DF_MODE
+Define this macro if neither @code{LIBGCC2_DOUBLE_TYPE_SIZE} nor
+@code{LIBGCC2_LONG_DOUBLE_TYPE_SIZE} is
+@code{DFmode} but you want @code{DFmode} routines in @file{libgcc2.a}
+anyway. If you don't define this and either @code{LIBGCC2_DOUBLE_TYPE_SIZE}
+or @code{LIBGCC2_LONG_DOUBLE_TYPE_SIZE} is 64 then the default is 1,
+otherwise it is 0.
+@end defmac
+
+@defmac LIBGCC2_HAS_XF_MODE
+Define this macro if @code{LIBGCC2_LONG_DOUBLE_TYPE_SIZE} is not
+@code{XFmode} but you want @code{XFmode} routines in @file{libgcc2.a}
+anyway. If you don't define this and @code{LIBGCC2_LONG_DOUBLE_TYPE_SIZE}
+is 80 then the default is 1, otherwise it is 0.
+@end defmac
+
+@defmac LIBGCC2_HAS_TF_MODE
+Define this macro if @code{LIBGCC2_LONG_DOUBLE_TYPE_SIZE} is not
+@code{TFmode} but you want @code{TFmode} routines in @file{libgcc2.a}
+anyway. If you don't define this and @code{LIBGCC2_LONG_DOUBLE_TYPE_SIZE}
+is 128 then the default is 1, otherwise it is 0.
+@end defmac
+
@defmac TARGET_FLT_EVAL_METHOD
A C expression for the value for @code{FLT_EVAL_METHOD} in @file{float.h},
assuming, if applicable, that the floating-point control word is in its
of words in each data entry.
@end defmac
-@node Escape Sequences
-@section Target Character Escape Sequences
-@cindex escape sequences
-
-By default, GCC assumes that the C character escape sequences and other
-characters take on their ASCII values for the target. If this is not
-correct, you must explicitly define all of the macros below. All of
-them must evaluate to constants; they are used in @code{case}
-statements.
-
-@findex TARGET_BELL
-@findex TARGET_BS
-@findex TARGET_CR
-@findex TARGET_DIGIT0
-@findex TARGET_ESC
-@findex TARGET_FF
-@findex TARGET_NEWLINE
-@findex TARGET_TAB
-@findex TARGET_VT
-@multitable {@code{TARGET_NEWLINE}} {Escape} {ASCII character}
-@item Macro @tab Escape @tab ASCII character
-@item @code{TARGET_BELL} @tab @kbd{\a} @tab @code{07}, @code{BEL}
-@item @code{TARGET_BS} @tab @kbd{\b} @tab @code{08}, @code{BS}
-@item @code{TARGET_CR} @tab @kbd{\r} @tab @code{0D}, @code{CR}
-@item @code{TARGET_DIGIT0} @tab @kbd{0} @tab @code{30}, @code{ZERO}
-@item @code{TARGET_ESC} @tab @kbd{\e}, @kbd{\E} @tab @code{1B}, @code{ESC}
-@item @code{TARGET_FF} @tab @kbd{\f} @tab @code{0C}, @code{FF}
-@item @code{TARGET_NEWLINE} @tab @kbd{\n} @tab @code{0A}, @code{LF}
-@item @code{TARGET_TAB} @tab @kbd{\t} @tab @code{09}, @code{HT}
-@item @code{TARGET_VT} @tab @kbd{\v} @tab @code{0B}, @code{VT}
-@end multitable
-
-@noindent
-Note that the @kbd{\e} and @kbd{\E} escapes are GNU extensions, not
-part of the C standard.
-
@node Registers
@section Register Usage
@cindex register usage
these registers when the target switches are opposed to them.)
@end defmac
-@defmac NON_SAVING_SETJMP
-If this macro is defined and has a nonzero value, it means that
-@code{setjmp} and related functions fail to save the registers, or that
-@code{longjmp} fails to restore them. To compensate, the compiler
-avoids putting variables in registers in functions that use
-@code{setjmp}.
-@end defmac
-
@defmac INCOMING_REGNO (@var{out})
Define this macro if the target machine has register windows. This C
expression returns the register number as seen by the called function
@code{BASE_REG_CLASS}.
@end defmac
+@defmac MODE_BASE_REG_REG_CLASS (@var{mode})
+A C expression whose value is the register class to which a valid
+base register must belong in order to be used in a base plus index
+register address. You should define this macro if base plus index
+addresses have different requirements than other base register uses.
+@end defmac
+
@defmac INDEX_REG_CLASS
A macro whose definition is the name of the class to which a valid
index register must belong. An index register is one used in an
@code{REGNO_OK_FOR_BASE_P}.
@end defmac
+@defmac REGNO_MODE_OK_FOR_REG_BASE_P (@var{num}, @var{mode})
+A C expression which is nonzero if register number @var{num} is suitable for
+use as a base register in base plus index operand addresses, accessing
+memory in mode @var{mode}. It may be either a suitable hard register or a
+pseudo register that has been allocated such a hard register. You should
+define this macro if base plus index addresses have different requirements
+than other base register uses.
+@end defmac
+
@defmac REGNO_OK_FOR_INDEX_P (@var{num})
A C expression which is nonzero if register number @var{num} is
suitable for use as an index register in operand addresses. It may be
* Function Entry::
* Profiling::
* Tail Calls::
+* Stack Smashing Protection::
@end menu
@node Frame Layout
Define this macro if pushing a word onto the stack moves the stack
pointer to a smaller address.
-When we say, ``define this macro if @dots{},'' it means that the
+When we say, ``define this macro if @dots{}'', it means that the
compiler checks this macro only with @code{#ifdef} so the precise
definition used does not matter.
@end defmac
@end defmac
@defmac FRAME_GROWS_DOWNWARD
-Define this macro if the addresses of local variable slots are at negative
-offsets from the frame pointer.
+Define this macro to non-zero value if the addresses of local variable slots
+are at negative offsets from the frame pointer.
@end defmac
@defmac ARGS_GROW_DOWNWARD
machines. See @file{function.c} for details.
@end defmac
+@defmac INITIAL_FRAME_ADDRESS_RTX
+A C expression whose value is RTL representing the address of the initial
+ stack frame. This address is passed to @code{RETURN_ADDR_RTX} and
+@code{DYNAMIC_CHAIN_ADDRESS}.
+If you don't define this macro, the default is to return
+@code{hard_frame_pointer_rtx}.
+This default is usually correct unless @code{-fomit-frame-pointer} is in
+effect.
+Define this macro in order to make @code{__builtin_frame_address (0)} and
+@code{__builtin_return_address (0)} work even in absence of a hard frame pointer.
+@end defmac
+
@defmac DYNAMIC_CHAIN_ADDRESS (@var{frameaddr})
A C expression whose value is RTL representing the address in a stack
frame where the pointer to the caller's frame is stored. Assume that
terminate the stack backtrace. New ports should avoid this.
@end defmac
+@deftypefn {Target Hook} void TARGET_DWARF_HANDLE_FRAME_UNSPEC (const char *@var{label}, rtx @var{pattern}, int @var{index})
+This target hook allows the backend to emit frame-related insns that
+contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame debugging
+info engine will invoke it on insns of the form
+@smallexample
+(set (reg) (unspec [...] UNSPEC_INDEX))
+@end smallexample
+and
+@smallexample
+(set (reg) (unspec_volatile [...] UNSPECV_INDEX)).
+@end smallexample
+to let the backend emit the call frame instructions. @var{label} is
+the CFI label attached to the insn, @var{pattern} is the pattern of
+the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}.
+@end deftypefn
+
@defmac INCOMING_FRAME_SP_OFFSET
A C expression whose value is an integer giving the offset, in bytes,
from the value of the stack pointer register to the top of the stack
serves both purposes.
@end defmac
-@defmac FUNCTION_ARG_PARTIAL_NREGS (@var{cum}, @var{mode}, @var{type}, @var{named})
-A C expression for the number of words, at the beginning of an
-argument, that must be put in registers. The value must be zero for
+@deftypefn {Target Hook} int TARGET_ARG_PARTIAL_BYTES (CUMULATIVE_ARGS *@var{cum}, enum machine_mode @var{mode}, tree @var{type}, bool @var{named})
+This target hook returns the number of bytes at the beginning of an
+argument that must be put in registers. The value must be zero for
arguments that are passed entirely in registers or that are entirely
pushed on the stack.
On some machines, certain arguments must be passed partially in
registers and partially in memory. On these machines, typically the
-first @var{n} words of arguments are passed in registers, and the rest
+first few words of arguments are passed in registers, and the rest
on the stack. If a multi-word argument (a @code{double} or a
structure) crosses that boundary, its first few words must be passed
in registers and the rest must be pushed. This macro tells the
-compiler when this occurs, and how many of the words should go in
-registers.
+compiler when this occurs, and how many bytes should go in registers.
@code{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.
-@end defmac
+@end deftypefn
@deftypefn {Target Hook} bool TARGET_PASS_BY_REFERENCE (CUMULATIVE_ARGS *@var{cum}, enum machine_mode @var{mode}, tree @var{type}, bool @var{named})
This target hook should return @code{true} if an argument at the
function argument should be copied by the callee instead of copied
by the caller.
-For any argument for which the hook returns true, if it can be
+For any argument for which the hook returns true, if it can be
determined that the argument is not modified, then a copy need
not be generated.
being compiled. @var{n_named_args} is set to the number of named
arguments, including a structure return address if it is passed as a
parameter, when making a call. When processing incoming arguments,
-@var{n_named_args} is set to -1.
+@var{n_named_args} is set to @minus{}1.
When processing a call to a compiler support library function,
@var{libname} identifies which one. It is a @code{symbol_ref} rtx which
false.
@end deftypefn
+@deftypefn {Target Hook} tree TARGET_BUILD_BUILTIN_VA_LIST (void)
+This hook returns a type node for @code{va_list} for the target.
+The default version of the hook returns @code{void*}.
+@end deftypefn
+
@deftypefn {Target Hook} tree TARGET_GIMPLIFY_VA_ARG_EXPR (tree @var{valist}, tree @var{type}, tree *@var{pre_p}, tree *@var{post_p})
This hook performs target-specific gimplification of
@code{VA_ARG_EXPR}. The first two parameters correspond to the
@code{gimplify.c:gimplify_expr}.
@end deftypefn
+@deftypefn {Target Hook} bool TARGET_VALID_POINTER_MODE (enum machine_mode @var{mode})
+Define this to return nonzero if the port can handle pointers
+with machine mode @var{mode}. The default version of this
+hook returns true for both @code{ptr_mode} and @code{Pmode}.
+@end deftypefn
+
@deftypefn {Target Hook} bool TARGET_SCALAR_MODE_SUPPORTED_P (enum machine_mode @var{mode})
Define this to return nonzero if the port is prepared to handle
insns involving scalar mode @var{mode}. For a scalar mode to be
@c tell? --mew 5feb93
@end deftypefn
-@deftypefn {Target Hook} bool TARGET_LATE_RTL_PROLOGUE_EPILOGUE
-If set to @code{true}, it instructs the compiler to emit the RTL prologue
-and epilogue later in the game than usual, namely after all passes that
-modify the instructions (and not merely reorder them) have been run. In
-particular, the C variable @code{current_function_uses_only_leaf_regs} is
-valid at that point. This can be used on machines that have "register
-windows" to optimize away the regular "push" on the register stack.
-@xref{Leaf Functions}.
-@end deftypefn
-
@itemize @bullet
@item
@findex current_function_pretend_args_size
@code{DELAY_SLOTS_FOR_EPILOGUE}.
@end defmac
-@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, tree @var{function})
+@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, HOST_WIDE_INT @var{vcall_offset}, tree @var{function})
A function that outputs the assembler code for a thunk
function, used to implement C++ virtual function calls with multiple
inheritance. The thunk acts as a wrapper around a virtual function,
e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of
all other incoming arguments.
-After the addition, emit code to jump to @var{function}, which is a
+Then, if @var{vcall_offset} is nonzero, an additional adjustment should be
+made after adding @code{delta}. In particular, if @var{p} is the
+adjusted pointer, the following adjustment should be made:
+
+@smallexample
+p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]
+@end smallexample
+
+After the additions, emit code to jump to @var{function}, which is a
@code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does
not touch the return address. Hence returning from @var{FUNCTION} will
return to whoever called the current @samp{thunk}.
not support varargs.
@end deftypefn
-@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_VCALL_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, int @var{vcall_offset}, tree @var{function})
-A function like @code{TARGET_ASM_OUTPUT_MI_THUNK}, except that if
-@var{vcall_offset} is nonzero, an additional adjustment should be made
-after adding @code{delta}. In particular, if @var{p} is the
-adjusted pointer, the following adjustment should be made:
-
-@smallexample
-p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]
-@end smallexample
-
-@noindent
-If this function is defined, it will always be used in place of
-@code{TARGET_ASM_OUTPUT_MI_THUNK}.
+@deftypefn {Target Hook} bool TARGET_ASM_CAN_OUTPUT_MI_THUNK (tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, HOST_WIDE_INT @var{vcall_offset}, tree @var{function})
+A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able
+to output the assembler code for the thunk function specified by the
+arguments it is passed, and false otherwise. In the latter case, the
+generic approach will be used by the C++ front end, with the limitations
+previously exposed.
@end deftypefn
@node Profiling
may vary greatly between different architectures.
@end deftypefn
+@node Stack Smashing Protection
+@subsection Stack smashing protection
+@cindex stack smashing protection
+
+@deftypefn {Target Hook} tree TARGET_STACK_PROTECT_GUARD (void)
+This hook returns a @code{DECL} node for the external variable to use
+for the stack protection guard. This variable is initialized by the
+runtime to some random value and is used to initialize the guard value
+that is placed at the top of the local stack frame. The type of this
+variable must be @code{ptr_type_node}.
+
+The default version of this hook creates a variable called
+@samp{__stack_chk_guard}, which is normally defined in @file{libgcc2.c}.
+@end deftypefn
+
+@deftypefn {Target Hook} tree TARGET_STACK_PROTECT_FAIL (void)
+This hook returns a tree expression that alerts the runtime that the
+stack protect guard variable has been modified. This expression should
+involve a call to a @code{noreturn} function.
+
+The default version of this hook invokes a function called
+@samp{__stack_chk_fail}, taking no arguments. This function is
+normally defined in @file{libgcc2.c}.
+@end deftypefn
+
@node Varargs
@section Implementing the Varargs Macros
@cindex varargs implementation
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},
-but @code{TARGET_PRETEND_OUTOGOING_VARARGS_NAMED} returns @code{true},
+but @code{TARGET_PRETEND_OUTGOING_VARARGS_NAMED} returns @code{true},
then all arguments are treated as named. Otherwise, all named arguments
except the last are treated as named.
functions (like @code{__cmpdi2}) return 0 to indicate that the first
operand is smaller than the second, 1 to indicate that they are equal,
and 2 to indicate that the first operand is greater than the second.
-If this macro evalutes to @code{false} the comparison functions return
--1, 0, and 1 instead of 0, 1, and 2. If the target uses the routines
+If this macro evaluates to @code{false} the comparison functions return
+@minus{}1, 0, and 1 instead of 0, 1, and 2. If the target uses the routines
in @file{libgcc.a}, you do not need to define this macro.
@end defmac
@code{REG_OK_FOR_BASE_P}.
@end defmac
+@defmac REG_MODE_OK_FOR_REG_BASE_P (@var{x}, @var{mode})
+A C expression which is nonzero if @var{x} (assumed to be a @code{reg} RTX)
+is suitable for use as a base register in base plus index operand addresses,
+accessing memory in mode @var{mode}. It may be either a suitable hard
+register or a pseudo register that has been allocated such a hard register.
+You should define this macro if base plus index addresses have different
+requirements than other base register uses.
+@end defmac
+
@defmac REG_OK_FOR_INDEX_P (@var{x})
A C expression that is nonzero if @var{x} (assumed to be a @code{reg}
RTX) is valid for use as an index register.
anything @code{CONSTANT_P} is valid.
@end defmac
+@deftypefn {Target Hook} rtx TARGET_DELEGITIMIZE_ADDRESS (rtx @var{x})
+This hook is used to undo the possibly obfuscating effects of the
+@code{LEGITIMIZE_ADDRESS} and @code{LEGITIMIZE_RELOAD_ADDRESS} target
+macros. Some backend implementations of these macros wrap symbol
+references inside an @code{UNSPEC} rtx to represent PIC or similar
+addressing modes. This target hook allows GCC's optimizers to understand
+the semantics of these opaque @code{UNSPEC}s by converting them back
+into their original form.
+@end deftypefn
+
+@deftypefn {Target Hook} bool TARGET_CANNOT_FORCE_CONST_MEM (rtx @var{x})
+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.
+
+The primary reason to define this hook is to prevent reload from
+deciding that a non-legitimate constant would be better reloaded
+from the constant pool instead of spilling and reloading a register
+holding the constant. This restriction is often true of addresses
+of TLS symbols for various targets.
+@end deftypefn
+
+@deftypefn {Target Hook} tree TARGET_VECTORIZE_BUILTIN_MASK_FOR_LOAD (void)
+This hook should return the DECL of a function @var{f} that given an
+address @var{addr} as an argument returns a mask @var{m} that can be
+used to extract from two vectors the relevant data that resides in
+@var{addr} in case @var{addr} is not properly aligned.
+
+The autovectrizer, when vectorizing a load operation from an address
+@var{addr} that may be unaligned, will generate two vector loads from
+the two aligned addresses around @var{addr}. It then generates a
+@code{REALIGN_LOAD} operation to extract the relevant data from the
+two loaded vectors. The first two arguments to @code{REALIGN_LOAD},
+@var{v1} and @var{v2}, are the two vectors, each of size @var{VS}, and
+the third argument, @var{OFF}, defines how the data will be extracted
+from these two vectors: if @var{OFF} is 0, then the returned vector is
+@var{v2}; otherwise, the returned vector is composed from the last
+@var{VS}-@var{OFF} elements of @var{v1} concatenated to the first
+@var{OFF} elements of @var{v2}.
+
+If this hook is defined, the autovectorizer will generate a call
+to @var{f} (using the DECL tree that this hook returns) and will
+use the return value of @var{f} as the argument @var{OFF} to
+@code{REALIGN_LOAD}. Therefore, the mask @var{m} returned by @var{f}
+should comply with the semantics expected by @code{REALIGN_LOAD}
+described above.
+If this hook is not defined, then @var{addr} will be used as
+the argument @var{OFF} to @code{REALIGN_LOAD}, in which case the low
+log2(@var{VS})-1 bits of @var{addr} will be considered.
+@end deftypefn
+
@node Condition Code
@section Condition Code Status
@cindex condition code status
mechanism will be used. Used by @code{__builtin_memset} when storing
values other than constant zero and by @code{__builtin_strcpy} when
when called with a constant source string.
-Defaults to to 1 if @code{move_by_pieces_ninsns} returns less
+Defaults to 1 if @code{move_by_pieces_ninsns} returns less
than @code{MOVE_RATIO}.
@end defmac
for multiplications, @code{COSTS_N_INSNS (7)} for division and modulus
operations, and @code{COSTS_N_INSNS (1)} for all other operations.
-When optimizing for code size, i.e@. when @code{optimize_size} is
+When optimizing for code size, i.e.@: when @code{optimize_size} is
nonzero, this target hook should be used to estimate the relative
size cost of an expression, again relative to @code{COSTS_N_INSNS}.
@end deftypefn
@deftypefn {Target Hook} void TARGET_SCHED_FINISH_GLOBAL (FILE *@var{file}, int @var{verbose})
-This is the cleanup hook corresponding to TARGET_SCHED_INIT_GLOBAL.
+This is the cleanup hook corresponding to @code{TARGET_SCHED_INIT_GLOBAL}.
@var{file} is either a null pointer, or a stdio stream to write any debug output to.
@var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.
@end deftypefn
delays, however: (b) there's a better chance to predict the actual grouping
that will be formed, and (c) correctly emulating the grouping can be very
important. In such targets one may want to allow issuing dependent insns
-closer to one another - i.e, closer than the dependence distance; however,
+closer to one another---i.e., closer than the dependence distance; however,
not in cases of "costly dependences", which this hooks allows to define.
@end deftypefn
not exist.
@end defmac
+@defmac INIT_ARRAY_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
+part of the @code{.init_array} (or equivalent) section. If not
+defined, GCC will assume such a section does not exist. Do not define
+both this macro and @code{INIT_SECTION_ASM_OP}.
+@end defmac
+
+@defmac FINI_ARRAY_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
+part of the @code{.fini_array} (or equivalent) section. If not
+defined, GCC will assume such a section does not exist. Do not define
+both this macro and @code{FINI_SECTION_ASM_OP}.
+@end defmac
+
@defmac CRT_CALL_STATIC_FUNCTION (@var{section_op}, @var{function})
If defined, an ASM statement that switches to a different section
via @var{section_op}, calls @var{function}, and switches back to
The default version of this function takes care of putting read-only
variables in @code{readonly_data_section}.
+
+See also @var{USE_SELECT_SECTION_FOR_FUNCTIONS}.
@end deftypefn
+@defmac USE_SELECT_SECTION_FOR_FUNCTIONS
+Define this macro if you wish TARGET_ASM_SELECT_SECTION to be called
+for @code{FUNCTION_DECL}s as well as for variables and constants.
+
+In the case of a @code{FUNCTION_DECL}, @var{reloc} will be zero if the
+function has been determined to be likely to be called, and nonzero if
+it is unlikely to be called.
+@end defmac
+
@deftypefn {Target Hook} void TARGET_ASM_UNIQUE_SECTION (tree @var{decl}, int @var{reloc})
Build up a unique section name, expressed as a @code{STRING_CST} node,
and assign it to @samp{DECL_SECTION_NAME (@var{decl})}.
of the filename using this macro.
@end defmac
-@defmac ASM_OUTPUT_SOURCE_LINE (@var{stream}, @var{line}, @var{counter})
-A C statement to output DBX or SDB debugging information before code
-for line number @var{line} of the current source file to the
-stdio stream @var{stream}. @var{counter} is the number of time the
-macro was invoked, including the current invocation; it is intended
-to generate unique labels in the assembly output.
-
-This macro need not be defined if the standard form of debugging
-information for the debugger in use is appropriate.
-@end defmac
-
@defmac ASM_OUTPUT_IDENT (@var{stream}, @var{string})
A C statement to output something to the assembler file to handle a
@samp{#ident} directive containing the text @var{string}. If this
definition of this macro is provided which is correct for most systems.
@end defmac
+@findex assemble_name_raw
+@defmac ASM_OUTPUT_INTERNAL_LABEL (@var{stream}, @var{name})
+Identical to @code{ASM_OUTPUT_lABEL}, except that @var{name} is known
+to refer to a compiler-generated label. The default definition uses
+@code{assemble_name_raw}, which is like @code{assemble_name} except
+that it is more efficient.
+@end defmac
+
@defmac SIZE_ASM_OP
A C string containing the appropriate assembler directive to specify the
size of a symbol, without any arguments. On systems that use ELF, the
table of contents.
@end defmac
-@defmac TARGET_SUPPORTS_HIDDEN
-A C expression that evaluates to true if the target supports hidden
-visibility. By default this expression is true if and only if
-@code{HAS_GAS_HIDDEN} is defined. Set this macro if the
-@code{HAS_GAS_HIDDEN} macro gives the wrong answer for this
-target. (For example, if the target's mechanism for supporting
-hidden visibility is not the same as GAS's.)
-@end defmac
-
@defmac ASM_OUTPUT_EXTERNAL (@var{stream}, @var{decl}, @var{name})
A C statement (sans semicolon) to output to the stdio stream
@var{stream} any text necessary for declaring the name of an external
beginning of a label has this effect. You should find out what
convention your system uses, and follow it.
-The default version of this function utilizes ASM_GENERATE_INTERNAL_LABEL.
+The default version of this function utilizes @code{ASM_GENERATE_INTERNAL_LABEL}.
@end deftypefn
@defmac ASM_OUTPUT_DEBUG_LABEL (@var{stream}, @var{prefix}, @var{num})
correct for most systems.
@end defmac
+@defmac TARGET_DEFERRED_OUTPUT_DEFS (@var{decl_of_name}, @var{decl_of_value})
+A C statement that evaluates to true if the assembler code which defines
+(equates) the symbol whose tree node is @var{decl_of_name} to have the value
+of the tree node @var{decl_of_value} should be emitted near the end of the
+current compilation unit. The default is to not defer output of defines.
+This macro affects defines output by @samp{ASM_OUTPUT_DEF} and
+@samp{ASM_OUTPUT_DEF_FROM_DECLS}.
+@end defmac
+
@defmac ASM_OUTPUT_WEAK_ALIAS (@var{stream}, @var{name}, @var{value})
A C statement to output to the stdio stream @var{stream} assembler code
which defines (equates) the weak symbol @var{name} to have the value
part of a cross compiler always uses @command{nm} for the target machine.
@end defmac
-@defmac COLLECT_PARSE_FLAG (@var{flag})
-Define this macro to be C code that examines @command{collect2} command
-line option @var{flag} and performs special actions if
-@command{collect2} needs to behave differently depending on @var{flag}.
-@end defmac
-
@defmac REAL_NM_FILE_NAME
Define this macro as a C string constant containing the file name to use
to execute @command{nm}. The default is to search the path normally for
@end defmac
@deftypefn {Target Hook} void TARGET_ASM_EMIT_UNWIND_LABEL (@var{stream}, @var{decl}, @var{for_eh}, @var{empty})
-This target hook emits a label at the beginning of each FDE. It
+This target hook emits a label at the beginning of each FDE@. It
should be defined on targets where FDEs need special labels, and it
should write the appropriate label, for the FDE associated with the
function declaration @var{decl}, to the stdio stream @var{stream}.
The third argument, @var{for_eh}, is a boolean: true if this is for an
exception table. The fourth argument, @var{empty}, is a boolean:
-true if this is a placeholder label for an omitted FDE.
+true if this is a placeholder label for an omitted FDE@.
The default is that FDEs are not given nonlocal labels.
@end deftypefn
also defined.
@end defmac
+@defmac EH_TABLES_CAN_BE_READ_ONLY
+Define this macro to 1 if your target is such that no frame unwind
+information encoding used with non-PIC code will ever require a
+runtime relocation, but the linker may not support merging read-only
+and read-write sections into a single read-write section.
+@end defmac
+
@defmac MASK_RETURN_ADDR
An rtx used to mask the return address found via @code{RETURN_ADDR_RTX}, so
that it does not contain any extraneous set bits in it.
these will be output by @code{TARGET_UNWIND_EMIT}.
@end defmac
+@deftypevar {Target Hook} bool TARGET_UNWID_TABLES_DEFAULT
+This variable should be set to @code{true} if the target ABI requires unwinding
+tables even when exceptions are not used.
+@end deftypevar
+
@defmac MUST_USE_SJLJ_EXCEPTIONS
This macro need only be defined if @code{DWARF2_UNWIND_INFO} is
runtime-variable. In that case, @file{except.h} cannot correctly
If not defined, the default is to return @code{NULL_RTX}.
@end deftypefn
+@deftypefn {Target Hook} bool TARGET_ASM_TTYPE (rtx @var{sym})
+This hook is used to output a reference from a frame unwinding table to
+the type_info object identified by @var{sym}. It should return @code{true}
+if the reference was output. Returning @code{false} will cause the
+reference to be output using the normal Dwarf2 routines.
+@end deftypefn
+
+@deftypefn {Target Hook} bool TARGET_ARM_EABI_UNWINDER
+This hook should be set to @code{true} on targets that use an ARM EABI
+based unwinding library, and @code{false} on other targets. This effects
+the format of unwinding tables, and how the unwinder in entered after
+running a cleanup. The default is @code{false}.
+@end deftypefn
+
@node Alignment Output
@subsection Assembler Commands for Alignment
do this. The default is @code{'P'}.
@end defmac
-@defmac DBX_MEMPARM_STABS_LETTER
-The letter to use in DBX symbol data to identify a symbol as a stack
-parameter. The default is @code{'p'}.
-@end defmac
-
@defmac DBX_FUNCTION_FIRST
Define this macro if the DBX information for a function and its
arguments should precede the assembler code for the function. Normally,
@end defmac
@defmac DBX_BLOCKS_FUNCTION_RELATIVE
-Define this macro if the value of a symbol describing the scope of a
-block (@code{N_LBRAC} or @code{N_RBRAC}) should be relative to the start
-of the enclosing function. Normally, GCC uses an absolute address.
+Define this macro, with value 1, if the value of a symbol describing
+the scope of a block (@code{N_LBRAC} or @code{N_RBRAC}) should be
+relative to the start of the enclosing function. Normally, GCC uses
+an absolute address.
+@end defmac
+
+@defmac DBX_LINES_FUNCTION_RELATIVE
+Define this macro, with value 1, if the value of a symbol indicating
+the current line number (@code{N_SLINE}) should be relative to the
+start of the enclosing function. Normally, GCC uses an absolute address.
@end defmac
@defmac DBX_USE_BINCL
output an @code{N_FUN} entry for the function @var{decl}.
@end defmac
-@defmac DBX_OUTPUT_FUNCTION_END (@var{stream}, @var{function})
-Define this macro if the target machine requires special output at the
-end of the debugging information for a function. The definition should
-be a C statement (sans semicolon) to output the appropriate information
-to @var{stream}. @var{function} is the @code{FUNCTION_DECL} node for
-the function.
+@defmac DBX_OUTPUT_SOURCE_LINE (@var{stream}, @var{line}, @var{counter})
+A C statement to output DBX debugging information before code for line
+number @var{line} of the current source file to the stdio stream
+@var{stream}. @var{counter} is the number of time the macro was
+invoked, including the current invocation; it is intended to generate
+unique labels in the assembly output.
+
+This macro should not be defined if the default output is correct, or
+if it can be made correct by defining @code{DBX_LINES_FUNCTION_RELATIVE}.
@end defmac
@defmac NO_DBX_FUNCTION_END
@defmac DBX_OUTPUT_MAIN_SOURCE_FILENAME (@var{stream}, @var{name})
A C statement to output DBX debugging information to the stdio stream
-@var{stream} which indicates that file @var{name} is the main source
+@var{stream}, which indicates that file @var{name} is the main source
file---the file specified as the input file for compilation.
This macro is called only once, at the beginning of compilation.
This macro need not be defined if the standard form of output
for DBX debugging information is appropriate.
+
+It may be necessary to refer to a label equal to the beginning of the
+text section. You can use @samp{assemble_name (stream, ltext_label_name)}
+to do so. If you do this, you must also set the variable
+@var{used_ltext_label_name} to @code{true}.
@end defmac
-@defmac DBX_OUTPUT_MAIN_SOURCE_DIRECTORY (@var{stream}, @var{name})
-A C statement to output DBX debugging information to the stdio stream
-@var{stream} which indicates that the current directory during
-compilation is named @var{name}.
+@defmac NO_DBX_MAIN_SOURCE_DIRECTORY
+Define this macro, with value 1, if GCC should not emit an indication
+of the current directory for compilation and current source language at
+the beginning of the file.
+@end defmac
-This macro need not be defined if the standard form of output
-for DBX debugging information is appropriate.
+@defmac NO_DBX_GCC_MARKER
+Define this macro, with value 1, if GCC should not emit an indication
+that this object file was compiled by GCC@. The default is to emit
+an @code{N_OPT} stab at the beginning of every source file, with
+@samp{gcc2_compiled.} for the string and value 0.
@end defmac
@defmac DBX_OUTPUT_MAIN_SOURCE_FILE_END (@var{stream}, @var{name})
A C statement to output DBX debugging information at the end of
-compilation of the main source file @var{name}.
+compilation of the main source file @var{name}. Output should be
+written to the stdio stream @var{stream}.
If you don't define this macro, nothing special is output at the end
of compilation, which is correct for most machines.
@end defmac
+@defmac DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END
+Define this macro @emph{instead of} defining
+@code{DBX_OUTPUT_MAIN_SOURCE_FILE_END}, if what needs to be output at
+the end of compilation is a @code{N_SO} stab with an empty string,
+whose value is the highest absolute text address in the file.
+@end defmac
+
@need 2000
@node SDB and DWARF
@subsection Macros for SDB and DWARF Output
Define this macro if GCC should produce dwarf version 2 format
debugging output in response to the @option{-g} option.
+@deftypefn {Target Hook} int TARGET_DWARF_CALLING_CONVENTION (tree @var{function})
+Define this to enable the dwarf attribute @code{DW_AT_calling_convention} to
+be emitted for each function. Instead of an integer return the enum
+value for the @code{DW_CC_} tag.
+@end deftypefn
+
To support optional call frame debugging information, you must also
define @code{INCOMING_RETURN_ADDR_RTX} and either set
@code{RTX_FRAME_RELATED_P} on the prologue insns if you use RTL for the
information not matter how you define @code{DWARF2_FRAME_INFO}.
@end defmac
-@defmac DWARF2_GENERATE_TEXT_SECTION_LABEL
-By default, the Dwarf 2 debugging information generator will generate a
-label to mark the beginning of the text section. If it is better simply
-to use the name of the text section itself, rather than an explicit label,
-to indicate the beginning of the text section, define this macro to zero.
-@end defmac
-
@defmac DWARF2_ASM_LINE_DEBUG_INFO
Define this macro to be a nonzero value if the assembler can generate Dwarf 2
line debug info sections. This will result in much more compact line number
reference to the given label, using an integer of the given size.
@end defmac
+@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_DWARF_DTPREL (FILE *@var{FILE}, int @var{size}, rtx @var{x})
+If defined, this target hook is a function which outputs a DTP-relative
+reference to the given TLS symbol of the specified size.
+@end deftypefn
+
@defmac PUT_SDB_@dots{}
Define these macros to override the assembler syntax for the special
SDB assembler directives. See @file{sdbout.c} for a list of these
required.
@end defmac
-@defmac SDB_GENERATE_FAKE
-Define this macro to override the usual method of constructing a dummy
-name for anonymous structure and union types. See @file{sdbout.c} for
-more information.
-@end defmac
-
@defmac SDB_ALLOW_UNKNOWN_REFERENCES
Define this macro to allow references to unknown structure,
union, or enumeration tags to be emitted. Standard COFF does not
assemblers choke if forward tags are used, while some require it.
@end defmac
+@defmac SDB_OUTPUT_SOURCE_LINE (@var{stream}, @var{line})
+A C statement to output SDB debugging information before code for line
+number @var{line} of the current source file to the stdio stream
+@var{stream}. The default is to emit an @code{.ln} directive.
+@end defmac
+
@need 2000
@node VMS Debug
@subsection Macros for VMS Debug Format
initializer for an array of integers. Each initializer element
N refers to an entity that needs mode switching, and specifies the number
of different modes that might need to be set for this entity.
-The position of the initializer in the initializer - starting counting at
-zero - determines the integer that is used to refer to the mode-switched
+The position of the initializer in the initializer---starting counting at
+zero---determines the integer that is used to refer to the mode-switched
entity in question.
In macros that take mode arguments / yield a mode result, modes are
represented as numbers 0 @dots{} N @minus{} 1. N is used to specify that no mode
@defmac MODE_AFTER (@var{mode}, @var{insn})
If this macro is defined, it is evaluated for every @var{insn} during
-mode switching. It determines the mode that an insn results in (if
+mode switching. It determines the mode that an insn results in (if
different from the incoming mode).
@end defmac
@defmac MODE_ENTRY (@var{entity})
If this macro is defined, it is evaluated for every @var{entity} that needs
-mode switching. It should evaluate to an integer, which is a mode that
-@var{entity} is assumed to be switched to at function entry. If @code{MODE_ENTRY}
+mode switching. It should evaluate to an integer, which is a mode that
+@var{entity} is assumed to be switched to at function entry. If @code{MODE_ENTRY}
is defined then @code{MODE_EXIT} must be defined.
@end defmac
@defmac MODE_EXIT (@var{entity})
If this macro is defined, it is evaluated for every @var{entity} that needs
-mode switching. It should evaluate to an integer, which is a mode that
-@var{entity} is assumed to be switched to at function exit. If @code{MODE_EXIT}
+mode switching. It should evaluate to an integer, which is a mode that
+@var{entity} is assumed to be switched to at function exit. If @code{MODE_EXIT}
is defined then @code{MODE_ENTRY} must be defined.
@end defmac
later in the function.
Another note: according to the MIPS spec, coprocessor 1 (if present) is
-the FPU. One accesses COP1 registers through standard mips
+the FPU@. One accesses COP1 registers through standard mips
floating-point support; they are not included in this mechanism.
There is one macro used in defining the MIPS coprocessor interface which
@section Parameters for Precompiled Header Validity Checking
@cindex parameters, precompiled headers
-@deftypefn {Target Hook} void * TARGET_GET_PCH_VALIDITY (size_t * @var{sz})
-Define this hook if your target needs to check a different collection
-of flags than the default, which is every flag defined by
-@code{TARGET_SWITCHES} and @code{TARGET_OPTIONS}. It should return
-some data which will be saved in the PCH file and presented to
-@code{TARGET_PCH_VALID_P} later; it should set @code{SZ} to the size
-of the data.
+@deftypefn {Target Hook} void *TARGET_GET_PCH_VALIDITY (size_t *@var{sz})
+This hook returns the data needed by @code{TARGET_PCH_VALID_P} and sets
+@samp{*@var{sz}} to the size of the data in bytes.
@end deftypefn
-@deftypefn {Target Hook} const char * TARGET_PCH_VALID_P (const void * @var{data}, size_t @var{sz})
-Define this hook if your target needs to check a different collection of
-flags than the default, which is every flag defined by @code{TARGET_SWITCHES}
-and @code{TARGET_OPTIONS}. It is given data which came from
-@code{TARGET_GET_PCH_VALIDITY} (in this version of this compiler, so there
-is no need for extensive validity checking). It returns @code{NULL} if
-it is safe to load a PCH file with this data, or a suitable error message
-if not. The error message will be presented to the user, so it should
-be localized.
+@deftypefn {Target Hook} const char *TARGET_PCH_VALID_P (const void *@var{data}, size_t @var{sz})
+This hook checks whether the options used to create a PCH file are
+compatible with the current settings. It returns @code{NULL}
+if so and a suitable error message if not. Error messages will
+be presented to the user and must be localized using @samp{_(@var{msg})}.
+
+@var{data} is the data that was returned by @code{TARGET_GET_PCH_VALIDITY}
+when the PCH file was created and @var{sz} is the size of that data in bytes.
+It's safe to assume that the data was created by the same version of the
+compiler, so no format checking is needed.
+
+The default definition of @code{default_pch_valid_p} should be
+suitable for most targets.
+@end deftypefn
+
+@deftypefn {Target Hook} const char *TARGET_CHECK_PCH_TARGET_FLAGS (int @var{pch_flags})
+If this hook is nonnull, the default implementation of
+@code{TARGET_PCH_VALID_P} will use it to check for compatible values
+of @code{target_flags}. @var{pch_flags} specifies the value that
+@code{target_flags} had when the PCH file was created. The return
+value is the same as for @code{TARGET_PCH_VALID_P}.
@end deftypefn
@node C++ ABI
whose elements have the indicated @var{type}. Assumes that it is already
known that a cookie is needed. The default is
@code{max(sizeof (size_t), alignof(type))}, as defined in section 2.7 of the
-IA64/Generic C++ ABI.
+IA64/Generic C++ ABI@.
@end deftypefn
@deftypefn {Target Hook} bool TARGET_CXX_COOKIE_HAS_SIZE (void)
@deftypefn {Target Hook} int TARGET_CXX_IMPORT_EXPORT_CLASS (tree @var{type}, int @var{import_export})
If defined by a backend this hook allows the decision made to export
class @var{type} to be overruled. Upon entry @var{import_export}
-will contain 1 if the class is going to be exported, -1 if it is going
+will contain 1 if the class is going to be exported, @minus{}1 if it is going
to be imported and 0 otherwise. This function should return the
modified value and perform any other actions necessary to support the
backend's targeted operating system.
method. The default is to return @code{true}.
@end deftypefn
-@deftypefn {Target Hook} bool TARGET_CXX_EXPORT_CLASS_DATA (void)
-If this hook returns false (the default), then virtual tables and RTTI
-data structures will have the ELF visibility of their containing
-class. If this hook returns true, then these data structures will
-have ELF ``default'' visibility, independently of the visibility of
-the containing class.
+@deftypefn {Target Hook} void TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY (tree @var{decl})
+@var{decl} is a virtual table, virtual table table, typeinfo object,
+or other similar implicit class data object that will be emitted with
+external linkage in this translation unit. No ELF visibility has been
+explicitly specified. If the target needs to specify a visibility
+other than that of the containing class, use this hook to set
+@code{DECL_VISIBILITY} and @code{DECL_VISIBILITY_SPECIFIED}.
+@end deftypefn
+
+@deftypefn {Target Hook} bool TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT (void)
+This hook returns true (the default) if virtual tables and other
+similar implicit class data objects are always COMDAT if they have
+external linkage. If this hook returns false, then class data for
+classes whose virtual table will be emitted in only one translation
+unit will not be COMDAT.
+@end deftypefn
+
+@deftypefn {Target Hook} bool TARGET_CXX_USE_AEABI_ATEXIT (void)
+This hook returns true if @code{__aeabi_atexit} (as defined by the ARM EABI)
+should be used to register static destructors when @option{-fuse-cxa-atexit}
+is in effect. The default is to return false to use @code{__cxa_atexit}.
@end deftypefn
@node Misc
is in effect.
@end defmac
-@defmac CASE_DROPS_THROUGH
-Define this if control falls through a @code{case} insn when the index
-value is out of range. This means the specified default-label is
-actually ignored by the @code{case} insn proper.
-@end defmac
-
@defmac CASE_VALUES_THRESHOLD
Define this to be the smallest number of different values for which it
is best to use a jump-table instead of a tree of conditional branches.
@defmac FLOAT_STORE_FLAG_VALUE (@var{mode})
A C expression that gives a nonzero @code{REAL_VALUE_TYPE} value that is
returned when comparison operators with floating-point results are true.
-Define this macro on machine that have comparison operations that return
+Define this macro on machines that have comparison operations that return
floating-point values. If there are no such operations, do not define
this macro.
@end defmac
+@defmac VECTOR_STORE_FLAG_VALUE (@var{mode})
+A C expression that gives a rtx representing the non-zero true element
+for vector comparisons. The returned rtx should be valid for the inner
+mode of @var{mode} which is guaranteed to be a vector mode. Define
+this macro on machines that have vector comparison operations that
+return a vector result. If there are no such operations, do not define
+this macro. Typically, this macro is defined as @code{const1_rtx} or
+@code{constm1_rtx}. This macro may return @code{NULL_RTX} to prevent
+the compiler optimizing such vector comparison operations for the
+given mode.
+@end defmac
+
@defmac CLZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value})
@defmacx CTZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value})
A C expression that evaluates to true if the architecture defines a value
and @code{ctz} at zero do @emph{not} extend to the builtin functions
visible to the user. Thus one may be free to adjust the value at will
to match the target expansion of these operations without fear of
-breaking the API.
+breaking the API@.
@end defmac
@defmac Pmode
@defmac REGISTER_TARGET_PRAGMAS ()
Define this macro if you want to implement any target-specific pragmas.
If defined, it is a C expression which makes a series of calls to
-@code{c_register_pragma} for each pragma. The macro may also do any
+@code{c_register_pragma} or @code{c_register_pragma_with_expansion}
+for each pragma. The macro may also do any
setup required for the pragmas.
The primary reason to define this macro is to provide compatibility with
@end defmac
@deftypefun void c_register_pragma (const char *@var{space}, const char *@var{name}, void (*@var{callback}) (struct cpp_reader *))
+@deftypefunx void c_register_pragma_with_expansion (const char *@var{space}, const char *@var{name}, void (*@var{callback}) (struct cpp_reader *))
-Each call to @code{c_register_pragma} establishes one pragma. The
+Each call to @code{c_register_pragma} or
+@code{c_register_pragma_with_expansion} establishes one pragma. The
@var{callback} routine will be called when the preprocessor encounters a
pragma of the form
on to cpplib's functions if necessary. You can lex tokens after the
@var{name} by calling @code{c_lex}. Tokens that are not read by the
callback will be silently ignored. The end of the line is indicated by
-a token of type @code{CPP_EOF}
+a token of type @code{CPP_EOF}. Macro expansion occurs on the
+arguments of pragmas registered with
+@code{c_register_pragma_with_expansion} but not on the arguments of
+pragmas registered with @code{c_register_pragma}.
For an example use of this routine, see @file{c4x.h} and the callback
routines defined in @file{c4x-c.c}.
of the underlying type is used by one or more same-size adjacent
bit-fields (that is, if its long:3, 32 bits is used in the record,
and any additional adjacent long bit-fields are packed into the same
-chunk of 32 bits. However, if the size changes, a new field of that
+chunk of 32 bits. However, if the size changes, a new field of that
size is allocated).
If both MS bit-fields and @samp{__attribute__((packed))} are used,
-the latter will take precedence. If @samp{__attribute__((packed))} is
+the latter will take precedence. If @samp{__attribute__((packed))} is
used on a single field when MS bit-fields are in use, it will take
precedence for that field, but the alignment of the rest of the structure
may affect its placement.
value.
@end defmac
+@defmac HANDLE_PRAGMA_PACK_WITH_EXPANSION
+Define this macro, as well as
+@code{HANDLE_SYSV_PRAGMA}, if macros should be expanded in the
+arguments of @samp{#pragma pack}.
+@end defmac
+
@defmac TARGET_DEFAULT_PACK_STRUCT
If your target requires a structure packing default other than 0 (meaning
-the machine default), define this macro the the necessary value (in bytes).
+the machine default), define this macro to the necessary value (in bytes).
This must be a value that would also valid to be used with
@samp{#pragma pack()} (that is, a small power of two).
@end defmac
You need not define this macro if it would always evaluate to zero.
@end defmac
-@deftypefn {Target Hook} tree TARGET_MD_ASM_CLOBBERS (tree @var{clobbers})
+@deftypefn {Target Hook} tree TARGET_MD_ASM_CLOBBERS (tree @var{outputs}, tree @var{inputs}, tree @var{clobbers})
This target hook should add to @var{clobbers} @code{STRING_CST} trees for
-any hard regs the port wishes to automatically clobber for all asms.
+any hard regs the port wishes to automatically clobber for an asm.
It should return the result of the last @code{tree_cons} used to add a
-clobber.
+clobber. The @var{outputs}, @var{inputs} and @var{clobber} lists are the
+corresponding parameters to the asm and may be inspected to avoid
+clobbering a register that is an input or output of the asm. You can use
+@code{decl_overlaps_hard_reg_set_p}, declared in @file{tree.h}, to test
+for overlap with regards to asm-declared registers.
@end deftypefn
@defmac MATH_LIBRARY
built-in function.
@end deftypefn
+@deftypefn {Target Hook} tree TARGET_RESOLVE_OVERLOADED_BUILTIN (tree @var{fndecl}, tree @var{arglist})
+
+Select a replacement for a machine specific built-in function that
+was set up by @samp{TARGET_INIT_BUILTINS}. This is done
+@emph{before} regular type checking, and so allows the target to
+implement a crude form of function overloading. @var{fndecl} is the
+declaration of the built-in function. @var{arglist} is the list of
+arguments passed to the built-in function. The result is a
+complete expression that implements the operation, usually
+another @code{CALL_EXPR}.
+@end deftypefn
+
+@deftypefn {Target Hook} tree TARGET_FOLD_BUILTIN (tree @var{fndecl}, tree @var{arglist}, bool @var{ignore})
+
+Fold a call to a machine specific built-in function that was set up by
+@samp{TARGET_INIT_BUILTINS}. @var{fndecl} is the declaration of the
+built-in function. @var{arglist} is the list of arguments passed to
+the built-in function. The result is another tree containing a
+simplified expression for the call's result. If @var{ignore} is true
+the value will be ignored.
+@end deftypefn
+
+@deftypefn {Target Hook} const char * TARGET_INVALID_WITHIN_DOLOOP (rtx @var{insn})
+
+Take an instruction in @var{insn} and return NULL if it is valid within a
+low-overhead loop, otherwise return a string why doloop could not be applied.
+
+Many targets use special registers for low-overhead looping. For any
+instruction that clobbers these this function should return a string indicating
+the reason why the doloop could not be applied.
+By default, the RTL loop optimizer does not use a present doloop pattern for
+loops containing function calls or branch on table instructions.
+@end deftypefn
+
@defmac MD_CAN_REDIRECT_BRANCH (@var{branch1}, @var{branch2})
Take a branch insn in @var{branch1} and another in @var{branch2}.
@deftypefn {Target Hook} bool TARGET_USE_LOCAL_THUNK_ALIAS_P (tree @var{fndecl})
This target hook returns @code{true} if it is safe to use a local alias
for a virtual function @var{fndecl} when constructing thunks,
-@code{false} otherwise. By default, the hook returns @code{true} for all
+@code{false} otherwise. By default, the hook returns @code{true} for all
functions, if a target supports aliases (i.e.@: defines
@code{ASM_OUTPUT_DEF}), @code{false} otherwise,
@end deftypefn
If defined, this macro is the number of entries in
@code{TARGET_FORMAT_TYPES}.
@end defmac
+
+@deftypefn {Target Hook} bool TARGET_RELAXED_ORDERING
+If set to @code{true}, means that the target's memory model does not
+guarantee that loads which do not depend on one another will access
+main memory in the order of the instruction stream; if ordering is
+important, an explicit memory barrier must be used. This is true of
+many recent processors which implement a policy of ``relaxed,''
+``weak,'' or ``release'' memory consistency, such as Alpha, PowerPC,
+and ia64. The default is @code{false}.
+@end deftypefn
+
+@deftypefn {Target Hook} const char *TARGET_INVALID_ARG_FOR_UNPROTOTYPED_FN (tree @var{typelist}, tree @var{funcdecl}, tree @var{val})
+If defined, this macro returns the diagnostic message when it is
+illegal to pass argument @var{val} to function @var{funcdecl}
+with prototype @var{typelist}.
+@end deftypefn
+
+@deftypefn {Target Hook} {const char *} TARGET_INVALID_CONVERSION (tree @var{fromtype}, tree @var{totype})
+If defined, this macro returns the diagnostic message when it is
+invalid to convert from @var{fromtype} to @var{totype}, or @code{NULL}
+if validity should be determined by the front end.
+@end deftypefn
+
+@deftypefn {Target Hook} {const char *} TARGET_INVALID_UNARY_OP (int @var{op}, tree @var{type})
+If defined, this macro returns the diagnostic message when it is
+invalid to apply operation @var{op} (where unary plus is denoted by
+@code{CONVERT_EXPR}) to an operand of type @var{type}, or @code{NULL}
+if validity should be determined by the front end.
+@end deftypefn
+
+@deftypefn {Target Hook} {const char *} TARGET_INVALID_BINARY_OP (int @var{op}, tree @var{type1}, tree @var{type2})
+If defined, this macro returns the diagnostic message when it is
+invalid to apply operation @var{op} to operands of types @var{type1}
+and @var{type2}, or @code{NULL} if validity should be determined by
+the front end.
+@end deftypefn
+
+@defmac TARGET_USE_JCR_SECTION
+This macro determines whether to use the JCR section to register Java
+classes. By default, TARGET_USE_JCR_SECTION is defined to 1 if both
+SUPPORTS_WEAK and TARGET_HAVE_NAMED_SECTIONS are true, else 0.
+@end defmac
OSDN Git Service
