/* Target hook definitions.
- Copyright (C) 2001-2017 Free Software Foundation, Inc.
+ Copyright (C) 2001-2018 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
DEFHOOK
(output_source_filename,
- "Output COFF information or DWARF debugging information which indicates\
- that filename @var{name} is the current source file to the stdio\
- stream @var{file}.\n\
+ "Output DWARF debugging information which indicates that filename\
+ @var{name} is the current source file to the stdio stream @var{file}.\n\
\n\
This target hook need not be defined if the standard form of output\
for the file format in use is appropriate.",
HOOK_VECTOR_END (sched)
-/* Functions relating to OpenMP and Cilk Plus SIMD clones. */
+/* Functions relating to OpenMP SIMD and __attribute__((simd)) clones. */
#undef HOOK_PREFIX
#define HOOK_PREFIX "TARGET_SIMD_CLONE_"
HOOK_VECTOR (TARGET_SIMD_CLONE, simd_clone)
int, (enum vect_cost_for_stmt type_of_cost, tree vectype, int misalign),
default_builtin_vectorization_cost)
+DEFHOOK
+(preferred_vector_alignment,
+ "This hook returns the preferred alignment in bits for accesses to\n\
+vectors of type @var{type} in vectorized code. This might be less than\n\
+or greater than the ABI-defined value returned by\n\
+@code{TARGET_VECTOR_ALIGNMENT}. It can be equal to the alignment of\n\
+a single element, in which case the vectorizer will not try to optimize\n\
+for alignment.\n\
+\n\
+The default hook returns @code{TYPE_ALIGN (@var{type})}, which is\n\
+correct for most targets.",
+ HOST_WIDE_INT, (const_tree type),
+ default_preferred_vector_alignment)
+
/* Return true if vector alignment is reachable (by peeling N
iterations) for the given scalar type. */
DEFHOOK
bool, (const_tree type, bool is_packed),
default_builtin_vector_alignment_reachable)
-/* Return true if a vector created for vec_perm_const is valid.
- A NULL indicates that all constants are valid permutations. */
DEFHOOK
-(vec_perm_const_ok,
- "Return true if a vector created for @code{vec_perm_const} is valid.",
- bool, (machine_mode, const unsigned char *sel),
+(vec_perm_const,
+ "This hook is used to test whether the target can permute up to two\n\
+vectors of mode @var{mode} using the permutation vector @code{sel}, and\n\
+also to emit such a permutation. In the former case @var{in0}, @var{in1}\n\
+and @var{out} are all null. In the latter case @var{in0} and @var{in1} are\n\
+the source vectors and @var{out} is the destination vector; all three are\n\
+registers of mode @var{mode}. @var{in1} is the same as @var{in0} if\n\
+@var{sel} describes a permutation on one vector instead of two.\n\
+\n\
+Return true if the operation is possible, emitting instructions for it\n\
+if rtxes are provided.\n\
+\n\
+@cindex @code{vec_perm@var{m}} instruction pattern\n\
+If the hook returns false for a mode with multibyte elements, GCC will\n\
+try the equivalent byte operation. If that also fails, it will try forcing\n\
+the selector into a register and using the @var{vec_perm@var{mode}}\n\
+instruction pattern. There is no need for the hook to handle these two\n\
+implementation approaches itself.",
+ bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
+ const vec_perm_indices &sel),
NULL)
/* Return true if the target supports misaligned store/load of a
(scalar_mode mode),
default_preferred_simd_mode)
+/* Returns the preferred mode for splitting SIMD reductions to. */
+DEFHOOK
+(split_reduction,
+ "This hook should return the preferred mode to split the final reduction\n\
+step on @var{mode} to. The reduction is then carried out reducing upper\n\
+against lower halves of vectors recursively until the specified mode is\n\
+reached. The default is @var{mode} which means no splitting.",
+ machine_mode,
+ (machine_mode),
+ default_split_reduction)
+
/* Returns a mask of vector sizes to iterate over when auto-vectorizing
after processing the preferred one derived from preferred_simd_mode. */
DEFHOOK
(autovectorize_vector_sizes,
- "This hook should return a mask of sizes that should be iterated over\n\
-after trying to autovectorize using the vector size derived from the\n\
-mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.\n\
-The default is zero which means to not iterate over other vector sizes.",
- unsigned int,
- (void),
+ "If the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is not\n\
+the only one that is worth considering, this hook should add all suitable\n\
+vector sizes to @var{sizes}, in order of decreasing preference. The first\n\
+one should be the size of @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.\n\
+\n\
+The hook does not need to do anything if the vector returned by\n\
+@code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is the only one relevant\n\
+for autovectorization. The default implementation does nothing.",
+ void,
+ (vector_sizes *sizes),
default_autovectorize_vector_sizes)
/* Function to get a target mode for a vector mask. */
is @var{length} bytes long and that contains @var{nunits} elements,\n\
if such a mode exists.",
opt_machine_mode,
- (unsigned nunits, unsigned length),
+ (poly_uint64 nunits, poly_uint64 length),
default_get_mask_mode)
+/* Function to say whether a masked operation is expensive when the
+ mask is all zeros. */
+DEFHOOK
+(empty_mask_is_expensive,
+ "This hook returns true if masked internal function @var{ifn} (really of\n\
+type @code{internal_fn}) should be considered expensive when the mask is\n\
+all zeros. GCC can then try to branch around the instruction instead.",
+ bool,
+ (unsigned ifn),
+ default_empty_mask_is_expensive)
+
/* Target builtin that implements vector gather operation. */
DEFHOOK
(builtin_gather,
"This hook should return true if @var{x} should not be emitted into\n\
debug sections.",
bool, (rtx x),
- hook_bool_rtx_false)
+ default_const_not_ok_for_debug_p)
/* Given an address RTX, say whether it is valid. */
DEFHOOK
unsigned int, (machine_mode mode),
default_min_divisions_for_recip_mul)
+DEFHOOK
+(truly_noop_truncation,
+ "This hook returns true if it is safe to ``convert'' a value of\n\
+@var{inprec} bits to one of @var{outprec} bits (where @var{outprec} is\n\
+smaller than @var{inprec}) by merely operating on it as if it had only\n\
+@var{outprec} bits. The default returns true unconditionally, which\n\
+is correct for most machines.\n\
+\n\
+If @code{TARGET_MODES_TIEABLE_P} returns false for a pair of modes,\n\
+suboptimal code can result if this hook returns true for the corresponding\n\
+mode sizes. Making this hook return false in such cases may improve things.",
+ bool, (poly_uint64 outprec, poly_uint64 inprec),
+ hook_bool_puint64_puint64_true)
+
/* If the representation of integral MODE is such that values are
always sign-extended to a wider mode MODE_REP then return
SIGN_EXTEND. Return UNKNOWN otherwise. */
Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}\n\
value even if the extension is not performed on certain hard registers\n\
as long as for the @code{REGNO_REG_CLASS} of these hard registers\n\
-@code{CANNOT_CHANGE_MODE_CLASS} returns nonzero.\n\
+@code{TARGET_CAN_CHANGE_MODE_CLASS} returns false.\n\
\n\
Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}\n\
describe two related properties. If you define\n\
extension.\n\
\n\
In order to enforce the representation of @code{mode},\n\
-@code{TRULY_NOOP_TRUNCATION} should return false when truncating to\n\
+@code{TARGET_TRULY_NOOP_TRUNCATION} should return false when truncating to\n\
@code{mode}.",
int, (scalar_int_mode mode, scalar_int_mode rep_mode),
default_mode_rep_extended)
#undef HOOK_PREFIX
#define HOOK_PREFIX "TARGET_"
+DEFHOOK
+(static_rtx_alignment,
+ "This hook returns the preferred alignment in bits for a\n\
+statically-allocated rtx, such as a constant pool entry. @var{mode}\n\
+is the mode of the rtx. The default implementation returns\n\
+@samp{GET_MODE_ALIGNMENT (@var{mode})}.",
+ HOST_WIDE_INT, (machine_mode mode),
+ default_static_rtx_alignment)
+
+DEFHOOK
+(constant_alignment,
+ "This hook returns the alignment in bits of a constant that is being\n\
+placed in memory. @var{constant} is the constant and @var{basic_align}\n\
+is the alignment that the object would ordinarily have.\n\
+\n\
+The default definition just returns @var{basic_align}.\n\
+\n\
+The typical use of this hook is to increase alignment for string\n\
+constants to be word aligned so that @code{strcpy} calls that copy\n\
+constants can be done inline. The function\n\
+@code{constant_alignment_word_strings} provides such a definition.",
+ HOST_WIDE_INT, (const_tree constant, HOST_WIDE_INT basic_align),
+ default_constant_alignment)
+
/* True if MODE is valid for the target. By "valid", we mean able to
be manipulated in non-trivial ways. In particular, this means all
the arithmetic is supported. */
HOST_WIDE_INT, (const_tree type),
default_vector_alignment)
+DEFHOOK
+(array_mode,
+ "Return the mode that GCC should use for an array that has\n\
+@var{nelems} elements, with each element having mode @var{mode}.\n\
+Return no mode if the target has no special requirements. In the\n\
+latter case, GCC looks for an integer mode of the appropriate size\n\
+if available and uses BLKmode otherwise. Usually the search for the\n\
+integer mode is limited to @code{MAX_FIXED_MODE_SIZE}, but the\n\
+@code{TARGET_ARRAY_MODE_SUPPORTED_P} hook allows a larger mode to be\n\
+used in specific cases.\n\
+\n\
+The main use of this hook is to specify that an array of vectors should\n\
+also have a vector mode. The default implementation returns no mode.",
+ opt_machine_mode, (machine_mode mode, unsigned HOST_WIDE_INT nelems),
+ hook_optmode_mode_uhwi_none)
+
/* True if we should try to use a scalar mode to represent an array,
overriding the usual MAX_FIXED_MODE limit. */
DEFHOOK
opt_scalar_float_mode, (int n, bool extended),
default_floatn_mode)
+DEFHOOK
+(floatn_builtin_p,
+ "Define this to return true if the @code{_Float@var{n}} and\n\
+@code{_Float@var{n}x} built-in functions should implicitly enable the\n\
+built-in function without the @code{__builtin_} prefix in addition to the\n\
+normal built-in function with the @code{__builtin_} prefix. The default is\n\
+to only enable built-in functions without the @code{__builtin_} prefix for\n\
+the GNU C langauge. In strict ANSI/ISO mode, the built-in function without\n\
+the @code{__builtin_} prefix is not enabled. The argument @code{FUNC} is the\n\
+@code{enum built_in_function} id of the function to be enabled.",
+ bool, (int func),
+ default_floatn_builtin_p)
+
/* Compute cost of moving data from a register of class FROM to one of
TO, using MODE. */
DEFHOOK
int, (rtx address, machine_mode mode, addr_space_t as, bool speed),
default_address_cost)
+/* Compute a cost for INSN. */
+DEFHOOK
+(insn_cost,
+ "This target hook describes the relative costs of RTL instructions.\n\
+\n\
+In implementing this hook, you can use the construct\n\
+@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\
+instructions.\n\
+\n\
+When optimizing for code size, i.e.@: when @code{speed} is\n\
+false, this target hook should be used to estimate the relative\n\
+size cost of an expression, again relative to @code{COSTS_N_INSNS}.",
+ int, (rtx_insn *insn, bool speed), NULL)
+
/* Give a cost, in RTX Costs units, for an edge. Like BRANCH_COST, but with
well defined units. */
DEFHOOK
bool, (rtx_insn *seq, struct noce_if_info *if_info),
default_noce_conversion_profitable_p)
+DEFHOOK
+(estimated_poly_value,
+ "Return an estimate of the runtime value of @var{val}, for use in\n\
+things like cost calculations or profiling frequencies. The default\n\
+implementation returns the lowest possible value of @var{val}.",
+ HOST_WIDE_INT, (poly_int64 val),
+ default_estimated_poly_value)
+
/* Permit speculative instructions in delay slots during delayed-branch
scheduling. */
DEFHOOK
the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}.",
void, (const char *label, rtx pattern, int index), NULL)
+DEFHOOK
+(dwarf_poly_indeterminate_value,
+ "Express the value of @code{poly_int} indeterminate @var{i} as a DWARF\n\
+expression, with @var{i} counting from 1. Return the number of a DWARF\n\
+register @var{R} and set @samp{*@var{factor}} and @samp{*@var{offset}} such\n\
+that the value of the indeterminate is:\n\
+@smallexample\n\
+value_of(@var{R}) / @var{factor} - @var{offset}\n\
+@end smallexample\n\
+\n\
+A target only needs to define this hook if it sets\n\
+@samp{NUM_POLY_INT_COEFFS} to a value greater than 1.",
+ unsigned int, (unsigned int i, unsigned int *factor, int *offset),
+ default_dwarf_poly_indeterminate_value)
+
/* ??? Documenting this hook requires a GFDL license grant. */
DEFHOOK_UNDOC
(stdarg_optimize_hook,
(cumulative_args_t ca, machine_mode mode, const_tree type, bool named),
default_function_arg_advance)
+DEFHOOK
+(function_arg_offset,
+ "This hook returns the number of bytes to add to the offset of an\n\
+argument of type @var{type} and mode @var{mode} when passed in memory.\n\
+This is needed for the SPU, which passes @code{char} and @code{short}\n\
+arguments in the preferred slot that is in the middle of the quad word\n\
+instead of starting at the top. The default implementation returns 0.",
+ HOST_WIDE_INT, (machine_mode mode, const_tree type),
+ default_function_arg_offset)
+
DEFHOOK
(function_arg_padding,
"This hook determines whether, and in which direction, to pad out\n\
nothing (the caller pops all). When this convention is in use,\n\
@var{funtype} is examined to determine whether a function takes a fixed\n\
number of arguments.",
- int, (tree fundecl, tree funtype, int size),
+ poly_int64, (tree fundecl, tree funtype, poly_int64 size),
default_return_pops_args)
/* Return a mode wide enough to copy any function value that might be
"This target hook returns the mode to be used when accessing raw return\
registers in @code{__builtin_return}. Define this macro if the value\
in @var{reg_raw_mode} is not correct.",
- machine_mode, (int regno),
+ fixed_size_mode, (int regno),
default_get_reg_raw_mode)
/* Return a mode wide enough to copy any argument value that might be
"This target hook returns the mode to be used when accessing raw argument\
registers in @code{__builtin_apply_args}. Define this macro if the value\
in @var{reg_raw_mode} is not correct.",
- machine_mode, (int regno),
+ fixed_size_mode, (int regno),
default_get_reg_raw_mode)
+/* Return true if a type is an empty record. */
+DEFHOOK
+(empty_record_p,
+ "This target hook returns true if the type is an empty record. The default\n\
+is to return @code{false}.",
+ bool, (const_tree type),
+ hook_bool_const_tree_false)
+
+/* Warn about the change in empty class parameter passing ABI. */
+DEFHOOK
+(warn_parameter_passing_abi,
+ "This target hook warns about the change in empty class parameter passing\n\
+ABI.",
+ void, (cumulative_args_t ca, tree type),
+ hook_void_CUMULATIVE_ARGS_tree)
+
HOOK_VECTOR_END (calls)
DEFHOOK
tree, (tree type, tree expr),
hook_tree_tree_tree_null)
+DEFHOOK
+(can_change_mode_class,
+ "This hook returns true if it is possible to bitcast values held in\n\
+registers of class @var{rclass} from mode @var{from} to mode @var{to}\n\
+and if doing so preserves the low-order bits that are common to both modes.\n\
+The result is only meaningful if @var{rclass} has registers that can hold\n\
+both @code{from} and @code{to}. The default implementation returns true.\n\
+\n\
+As an example of when such bitcasting is invalid, loading 32-bit integer or\n\
+floating-point objects into floating-point registers on Alpha extends them\n\
+to 64 bits. Therefore loading a 64-bit object and then storing it as a\n\
+32-bit object does not store the low-order 32 bits, as would be the case\n\
+for a normal register. Therefore, @file{alpha.h} defines\n\
+@code{TARGET_CAN_CHANGE_MODE_CLASS} to return:\n\
+\n\
+@smallexample\n\
+(GET_MODE_SIZE (from) == GET_MODE_SIZE (to)\n\
+ || !reg_classes_intersect_p (FLOAT_REGS, rclass))\n\
+@end smallexample\n\
+\n\
+Even if storing from a register in mode @var{to} would be valid,\n\
+if both @var{from} and @code{raw_reg_mode} for @var{rclass} are wider\n\
+than @code{word_mode}, then we must prevent @var{to} narrowing the\n\
+mode. This happens when the middle-end assumes that it can load\n\
+or store pieces of an @var{N}-word pseudo, and that the pseudo will\n\
+eventually be allocated to @var{N} @code{word_mode} hard registers.\n\
+Failure to prevent this kind of mode change will result in the\n\
+entire @code{raw_reg_mode} being modified instead of the partial\n\
+value that the middle-end intended.",
+ bool, (machine_mode from, machine_mode to, reg_class_t rclass),
+ hook_bool_mode_mode_reg_class_t_true)
+
/* Change pseudo allocno class calculated by IRA. */
DEFHOOK
(ira_change_pseudo_allocno_class,
\n\
Scratch operands in memory (constraint @code{\"=m\"} / @code{\"=&m\"}) are\n\
currently not supported. For the time being, you will have to continue\n\
-to use @code{SECONDARY_MEMORY_NEEDED} for that purpose.\n\
+to use @code{TARGET_SECONDARY_MEMORY_NEEDED} for that purpose.\n\
\n\
@code{copy_cost} also uses this target hook to find out how values are\n\
copied. If you want it to include some extra cost for the need to allocate\n\
secondary_reload_info *sri),
default_secondary_reload)
+DEFHOOK
+(secondary_memory_needed,
+ "Certain machines have the property that some registers cannot be copied\n\
+to some other registers without using memory. Define this hook on\n\
+those machines to return true if objects of mode @var{m} in registers\n\
+of @var{class1} can only be copied to registers of class @var{class2} by\n\
+ storing a register of @var{class1} into memory and loading that memory\n\
+location into a register of @var{class2}. The default definition returns\n\
+false for all inputs.",
+ bool, (machine_mode mode, reg_class_t class1, reg_class_t class2),
+ hook_bool_mode_reg_class_t_reg_class_t_false)
+
+DEFHOOK
+(secondary_memory_needed_mode,
+ "If @code{TARGET_SECONDARY_MEMORY_NEEDED} tells the compiler to use memory\n\
+when moving between two particular registers of mode @var{mode},\n\
+this hook specifies the mode that the memory should have.\n\
+\n\
+The default depends on @code{TARGET_LRA_P}. Without LRA, the default\n\
+is to use a word-sized mode for integral modes that are smaller than a\n\
+a word. This is right thing to do on most machines because it ensures\n\
+that all bits of the register are copied and prevents accesses to the\n\
+registers in a narrower mode, which some machines prohibit for\n\
+floating-point registers.\n\
+\n\
+However, this default behavior is not correct on some machines, such as\n\
+the DEC Alpha, that store short integers in floating-point registers\n\
+differently than in integer registers. On those machines, the default\n\
+widening will not work correctly and you must define this hook to\n\
+suppress that widening in some cases. See the file @file{alpha.c} for\n\
+details.\n\
+\n\
+With LRA, the default is to use @var{mode} unmodified.",
+ machine_mode, (machine_mode mode),
+ default_secondary_memory_needed_mode)
+
/* Given an rtx X being reloaded into a reg required to be in class CLASS,
return the class of reg to actually use. */
DEFHOOK
(rtx x, reg_class_t rclass),
default_preferred_output_reload_class)
+DEFHOOK
+(select_early_remat_modes,
+ "On some targets, certain modes cannot be held in registers around a\n\
+standard ABI call and are relatively expensive to spill to the stack.\n\
+The early rematerialization pass can help in such cases by aggressively\n\
+recomputing values after calls, so that they don't need to be spilled.\n\
+\n\
+This hook returns the set of such modes by setting the associated bits\n\
+in @var{modes}. The default implementation selects no modes, which has\n\
+the effect of disabling the early rematerialization pass.",
+ void, (sbitmap modes),
+ default_select_early_remat_modes)
+
DEFHOOK
(class_likely_spilled_p,
"A target hook which returns @code{true} if pseudos that have been assigned\n\
at register number @var{regno}, required to hold a value of mode\n\
@var{mode}. This hook must never return zero, even if a register\n\
cannot hold the requested mode - indicate that with\n\
-@code{TARGET_HARD_REGNO_MODE_OK} and/or @code{CANNOT_CHANGE_MODE_CLASS}\n\
-instead.\n\
+@code{TARGET_HARD_REGNO_MODE_OK} and/or\n\
+@code{TARGET_CAN_CHANGE_MODE_CLASS} instead.\n\
\n\
The default definition returns the number of words in @var{mode}.",
unsigned int, (unsigned int regno, machine_mode mode),
unsigned int, (void),
default_case_values_threshold)
+DEFHOOK
+(starting_frame_offset,
+ "This hook returns the offset from the frame pointer to the first local\n\
+variable slot to be allocated. If @code{FRAME_GROWS_DOWNWARD}, it is the\n\
+offset to @emph{end} of the first slot allocated, otherwise it is the\n\
+offset to @emph{beginning} of the first slot allocated. The default\n\
+implementation returns 0.",
+ HOST_WIDE_INT, (void),
+ hook_hwi_void_0)
+
/* Optional callback to advise the target to compute the frame layout. */
DEFHOOK
(compute_frame_layout,
void, (void),
hook_void_void)
+DEFHOOK
+(stack_clash_protection_final_dynamic_probe,
+ "Some targets make optimistic assumptions about the state of stack probing when they emit their prologues. On such targets a probe into the end of any dynamically allocated space is likely required for safety against stack clash style attacks. Define this variable to return nonzero if such a probe is required or zero otherwise. You need not define this macro if it would always have the value zero.",
+ bool, (rtx residual),
+ default_stack_clash_protection_final_dynamic_probe)
+
+
/* Functions specific to the C family of frontends. */
#undef HOOK_PREFIX
#define HOOK_PREFIX "TARGET_C_"
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