the alignment requirements of an unnamed bitfield's type.
@end deftypefn
+@deftypefn {Target Hook} bool TARGET_NARROW_VOLATILE_BITFIELDS (void)
+This target hook should return @code{true} if accesses to volatile bitfields
+should use the narrowest mode possible. It should return @code{false} if
+these accesses should use the bitfield container type.
+
+The default is @code{!TARGET_STRICT_ALIGN}.
+@end deftypefn
+
@defmac MEMBER_TYPE_FORCES_BLK (@var{field}, @var{mode})
Return 1 if a structure or array containing @var{field} should be accessed using
@code{BLKMODE}.
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}.
+
+If an insn has pseudos in it after register allocation, reload will go
+through the alternatives and call repeatedly @code{PREFERRED_RELOAD_CLASS}
+to find the best one. Returning @code{NO_REGS}, in this case, makes
+reload add a @code{!} in front of the constraint: the x86 back-end uses
+this feature to discourage usage of 387 registers when math is done in
+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
@defmac LIMIT_RELOAD_CLASS (@var{mode}, @var{class})
is found by the called function is not the same place that the
caller put it. This can be due to register windows, or it could
be because the function prologue moves it to a different place.
-@var{incoming} is @code{true} when the location is needed in
-the context of the called function, and @code{false} in the context of
+@var{incoming} is @code{1} or @code{2} when the location is needed in
+the context of the called function, and @code{0} in the context of
the caller.
-If @var{incoming} is @code{true} and the address is to be found on the
-stack, return a @code{mem} which refers to the frame pointer.
+If @var{incoming} is nonzero and the address is to be found on the
+stack, return a @code{mem} which refers to the frame pointer. If
+@var{incoming} is @code{2}, the result is being used to fetch the
+structure value address at the beginning of a function. If you need
+to emit adjusting code, you should do it at this point.
@end deftypefn
@defmac PCC_STATIC_STRUCT_RETURN
of passing dependence as a second parameter, it passes a type of that
dependence. This is useful to calculate cost of dependence between insns
not having the corresponding link. If @samp{TARGET_SCHED_ADJUST_COST_2} is
-definded it is used instead of @samp{TARGET_SCHED_ADJUST_COST}.
+defined it is used instead of @samp{TARGET_SCHED_ADJUST_COST}.
@end deftypefn
@deftypefn {Target Hook} void TARGET_SCHED_H_I_D_EXTENDED (void)
@deftypefn {Target Hook} int TARGET_SCHED_NEEDS_BLOCK_P (rtx @var{insn})
This hook is called by the insn scheduler during generation of recovery code
-for @var{insn}. It should return non-zero, if the corresponding check
+for @var{insn}. It should return nonzero, if the corresponding check
instruction should branch to recovery code, or zero otherwise.
@end deftypefn
speculative instruction for which the check should be generated.
@var{label} is either a label of a basic block, where recovery code should
be emitted, or a null pointer, when requested check doesn't branch to
-recovery code (a simple check). If @var{mutate_p} is non-zero, then
+recovery code (a simple check). If @var{mutate_p} is nonzero, then
a pattern for a branchy check corresponding to a simple check denoted by
@var{insn} should be generated. In this case @var{label} can't be null.
@end deftypefn
called on the first instruction of the ready list. The hook is used to
discard speculative instruction that stand first in the ready list from
being scheduled on the current cycle. For non-speculative instructions,
-the hook should always return non-zero. For example, in the ia64 backend
+the hook should always return nonzero. For example, in the ia64 backend
the hook is used to cancel data speculative insns when the ALAT table
is nearly full.
@end deftypefn
enabled/used. @var{flags} initially may have either the SCHED_RGN or SCHED_EBB
bit set. This denotes the scheduler pass for which the data should be
provided. The target backend should modify @var{flags} by modifying
-the bits correponding to the following features: USE_DEPS_LIST, USE_GLAT,
+the bits corresponding to the following features: USE_DEPS_LIST, USE_GLAT,
DETACH_LIFE_INFO, and DO_SPECULATION. For the DO_SPECULATION feature
an additional structure @var{spec_info} should be filled by the target.
The structure describes speculation types that can be used in the scheduler.
such cases may improve things.
@end defmac
+@deftypefn {Target Hook} int TARGET_MODE_REP_EXTENDED (enum machine_mode @var{mode}, enum machine_mode @var{rep_mode})
+The representation of an intergral mode can be such that the values
+are always extended to a wider integral mode. Return
+@code{SIGN_EXTEND} if values of @var{mode} are represented in
+sign-extended form to @var{rep_mode}. Return @code{UNKNOWN}
+otherwise. (Currently, none of the targets use zero-extended
+representation this way so unlike @code{LOAD_EXTEND_OP},
+@code{TARGET_MODE_REP_EXTENDED} is expected to return either
+@code{SIGN_EXTEND} or @code{UNKNOWN}. Also no target extends
+@var{mode} to @var{mode_rep} so that @var{mode_rep} is not the next
+widest integral mode and currently we take advantage of this fact.)
+
+Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}
+value even if the extension is not performed on certain hard registers
+as long as for the @code{REGNO_REG_CLASS} of these hard registers
+@code{CANNOT_CHANGE_MODE_CLASS} returns nonzero.
+
+Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}
+describe two related properties. If you define
+@code{TARGET_MODE_REP_EXTENDED (mode, word_mode)} you probably also want
+to define @code{LOAD_EXTEND_OP (mode)} to return the same type of
+extension.
+
+In order to enforce the representation of @code{mode},
+@code{TRULY_NOOP_TRUNCATION} should return false when truncating to
+@code{mode}.
+@end deftypefn
+
@defmac STORE_FLAG_VALUE
A C expression describing the value returned by a comparison operator
with an integral mode and stored by a store-flag instruction
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