- /* True if new jumps cannot be created, to replace existing ones or
- not, at the current point in the compilation. */
- bool (* cannot_modify_jumps_p) (void);
-
- /* Return a register class for which branch target register
- optimizations should be applied. */
- int (* branch_target_register_class) (void);
-
- /* Return true if branch target register optimizations should include
- callee-saved registers that are not already live during the current
- function. AFTER_PE_GEN is true if prologues and epilogues have
- already been generated. */
- bool (* branch_target_register_callee_saved) (bool after_pe_gen);
-
- /* True if the constant X cannot be placed in the constant pool. */
- bool (* cannot_force_const_mem) (rtx);
-
- /* True if the insn X cannot be duplicated. */
- bool (* cannot_copy_insn_p) (rtx);
-
- /* True if X is considered to be commutative. */
- bool (* commutative_p) (const_rtx, int);
-
- /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
- rtx (* delegitimize_address) (rtx);
-
- /* True if the given constant can be put into an object_block. */
- bool (* use_blocks_for_constant_p) (enum machine_mode, const_rtx);
-
- /* The minimum and maximum byte offsets for anchored addresses. */
- HOST_WIDE_INT min_anchor_offset;
- HOST_WIDE_INT max_anchor_offset;
-
- /* True if section anchors can be used to access the given symbol. */
- bool (* use_anchors_for_symbol_p) (const_rtx);
-
- /* True if it is OK to do sibling call optimization for the specified
- call expression EXP. DECL will be the called function, or NULL if
- this is an indirect call. */
- bool (*function_ok_for_sibcall) (tree decl, tree exp);
-
- /* Establish appropriate back-end context for processing the function
- FNDECL. The argument might be NULL to indicate processing at top
- level, outside of any function scope. */
- void (*set_current_function) (tree fndecl);
-
- /* True if EXP should be placed in a "small data" section. */
- bool (* in_small_data_p) (const_tree);
-
- /* True if EXP names an object for which name resolution must resolve
- to the current executable or shared library. */
- bool (* binds_local_p) (const_tree);
-
- /* Modify and return the identifier of a DECL's external name,
- originally identified by ID, as required by the target,
- (eg, append @nn to windows32 stdcall function names).
- The default is to return ID without modification. */
- tree (* mangle_decl_assembler_name) (tree decl, tree id);
-
- /* Do something target-specific to record properties of the DECL into
- the associated SYMBOL_REF. */
- void (* encode_section_info) (tree, rtx, int);
-
- /* Undo the effects of encode_section_info on the symbol string. */
- const char * (* strip_name_encoding) (const char *);
-
- /* If shift optabs for MODE are known to always truncate the shift count,
- return the mask that they apply. Return 0 otherwise. */
- unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode);
-
- /* Return the number of divisions in the given MODE that should be present,
- so that it is profitable to turn the division into a multiplication by
- the reciprocal. */
- unsigned int (* min_divisions_for_recip_mul) (enum machine_mode mode);
-
- /* 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. */
- /* Note that the return type ought to be RTX_CODE, but that's not
- necessarily defined at this point. */
- int (* mode_rep_extended) (enum machine_mode mode,
- enum machine_mode mode_rep);
-
- /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
- bool (* valid_pointer_mode) (enum machine_mode mode);
-
- /* 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. */
- bool (* scalar_mode_supported_p) (enum machine_mode mode);
-
- /* Similarly for vector modes. "Supported" here is less strict. At
- least some operations are supported; need to check optabs or builtins
- for further details. */
- bool (* vector_mode_supported_p) (enum machine_mode mode);
-
- /* Compute a (partial) cost for rtx X. Return true if the complete
- cost has been computed, and false if subexpressions should be
- scanned. In either case, *TOTAL contains the cost result. */
- /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
- not necessarily defined at this point. */
- bool (* rtx_costs) (rtx x, int code, int outer_code, int *total, bool speed);
-
- /* Compute the cost of X, used as an address. Never called with
- invalid addresses. */
- int (* address_cost) (rtx x, bool speed);
-
- /* Return where to allocate pseudo for a given hard register initial
- value. */
- rtx (* allocate_initial_value) (rtx x);
-
- /* Return nonzero if evaluating UNSPEC[_VOLATILE] X might cause a trap.
- FLAGS has the same meaning as in rtlanal.c: may_trap_p_1. */
- int (* unspec_may_trap_p) (const_rtx x, unsigned flags);
-
- /* Given a register, this hook should return a parallel of registers
- to represent where to find the register pieces. Define this hook
- if the register and its mode are represented in Dwarf in
- non-contiguous locations, or if the register should be
- represented in more than one register in Dwarf. Otherwise, this
- hook should return NULL_RTX. */
- rtx (* dwarf_register_span) (rtx);
-
- /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
- entries not corresponding directly to registers below
- FIRST_PSEUDO_REGISTER, this hook should generate the necessary
- code, given the address of the table. */
- void (* init_dwarf_reg_sizes_extra) (tree);
-
- /* Fetch the fixed register(s) which hold condition codes, for
- targets where it makes sense to look for duplicate assignments to
- the condition codes. This should return true if there is such a
- register, false otherwise. The arguments should be set to the
- fixed register numbers. Up to two condition code registers are
- supported. If there is only one for this target, the int pointed
- at by the second argument should be set to -1. */
- bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *);
-
- /* If two condition code modes are compatible, return a condition
- code mode which is compatible with both, such that a comparison
- done in the returned mode will work for both of the original
- modes. If the condition code modes are not compatible, return
- VOIDmode. */
- enum machine_mode (* cc_modes_compatible) (enum machine_mode,
- enum machine_mode);
-
- /* Do machine-dependent code transformations. Called just before
- delayed-branch scheduling. */
- void (* machine_dependent_reorg) (void);
-
- /* Create the __builtin_va_list type. */
- tree (* build_builtin_va_list) (void);
-
- /* Get the cfun/fndecl calling abi __builtin_va_list type. */
- tree (* fn_abi_va_list) (tree);
-
- /* Get the __builtin_va_list type dependent on input type. */
- tree (* canonical_va_list_type) (tree);
-
- /* Expand the __builtin_va_start builtin. */
- void (* expand_builtin_va_start) (tree valist, rtx nextarg);
-
- /* Gimplifies a VA_ARG_EXPR. */
- tree (* gimplify_va_arg_expr) (tree valist, tree type, gimple_seq *pre_p,
- gimple_seq *post_p);
-
- /* Validity-checking routines for PCH files, target-specific.
- get_pch_validity returns a pointer to the data to be stored,
- and stores the size in its argument. pch_valid_p gets the same
- information back and returns NULL if the PCH is valid,
- or an error message if not.
- */
- void * (* get_pch_validity) (size_t *);
- const char * (* pch_valid_p) (const void *, size_t);
-
- /* If nonnull, this function checks whether a PCH file with the
- given set of target flags can be used. It returns NULL if so,
- otherwise it returns an error message. */
- const char *(*check_pch_target_flags) (int);
-
- /* True if the compiler should give an enum type only as many
- bytes as it takes to represent the range of possible values of
- that type. */
- bool (* default_short_enums) (void);
-
- /* This target hook returns an rtx that is used to store the address
- of the current frame into the built-in setjmp buffer. */
- rtx (* builtin_setjmp_frame_value) (void);
-
- /* This target hook should add STRING_CST trees for any hard regs
- the port wishes to automatically clobber for an asm. */
- tree (* md_asm_clobbers) (tree, tree, tree);
-
- /* This target hook allows the backend to specify a calling convention
- in the debug information. This function actually returns an
- enum dwarf_calling_convention, but because of forward declarations
- and not wanting to include dwarf2.h everywhere target.h is included
- the function is being declared as an int. */
- int (* dwarf_calling_convention) (const_tree);
-
- /* This target hook allows the backend to emit frame-related insns that
- contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info
- engine will invoke it on insns of the form
- (set (reg) (unspec [...] UNSPEC_INDEX))
- and
- (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
- to let the backend emit the call frame instructions. */
- void (* dwarf_handle_frame_unspec) (const char *, rtx, int);
-
- /* Perform architecture specific checking of statements gimplified
- from VA_ARG_EXPR. STMT is the statement. Returns true if the statement
- doesn't need to be checked for va_list references. */
- bool (* stdarg_optimize_hook) (struct stdarg_info *ai, const_gimple stmt);
-
- /* This target hook allows the operating system to override the DECL
- that represents the external variable that contains the stack
- protection guard variable. The type of this DECL is ptr_type_node. */
- tree (* stack_protect_guard) (void);
-
- /* This target hook allows the operating system to override the CALL_EXPR
- that is invoked when a check vs the guard variable fails. */
- tree (* stack_protect_fail) (void);
-
- /* Returns NULL if target supports the insn within a doloop block,
- otherwise it returns an error message. */
- const char * (*invalid_within_doloop) (const_rtx);
-
- /* DECL is a variable or function with __attribute__((dllimport))
- specified. Use this hook if the target needs to add extra validation
- checks to handle_dll_attribute (). */
- bool (* valid_dllimport_attribute_p) (const_tree decl);
-
- /* Functions relating to calls - argument passing, returns, etc. */
- struct calls {
- bool (*promote_function_args) (const_tree fntype);
- bool (*promote_function_return) (const_tree fntype);
- bool (*promote_prototypes) (const_tree fntype);
- rtx (*struct_value_rtx) (tree fndecl, int incoming);
- bool (*return_in_memory) (const_tree type, const_tree fndecl);
- bool (*return_in_msb) (const_tree type);
-
- /* Return true if a parameter must be passed by reference. TYPE may
- be null if this is a libcall. CA may be null if this query is
- from __builtin_va_arg. */
- bool (*pass_by_reference) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
- const_tree type, bool named_arg);
-
- rtx (*expand_builtin_saveregs) (void);
- /* Returns pretend_argument_size. */
- void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
- tree type, int *pretend_arg_size,
- int second_time);
- bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca);
- /* Returns true if we should use
- targetm.calls.setup_incoming_varargs() and/or
- targetm.calls.strict_argument_naming(). */
- bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca);
-
- /* Given a complex type T, return true if a parameter of type T
- should be passed as two scalars. */
- bool (* split_complex_arg) (const_tree type);
-
- /* Return true if type T, mode MODE, may not be passed in registers,
- but must be passed on the stack. */
- /* ??? This predicate should be applied strictly after pass-by-reference.
- Need audit to verify that this is the case. */
- bool (* must_pass_in_stack) (enum machine_mode mode, const_tree t);
-
- /* Return true if type TYPE, mode MODE, which is passed by reference,
- should have the object copy generated by the callee rather than
- the caller. It is never called for TYPE requiring constructors. */
- bool (* callee_copies) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
- const_tree type, bool named);
-
- /* Return zero for arguments passed entirely on the stack or entirely
- in registers. If passed in both, return the number of bytes passed
- in registers; the balance is therefore passed on the stack. */
- int (* arg_partial_bytes) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
- tree type, bool named);
-
- /* Return the diagnostic message string if function without a prototype
- is not allowed for this 'val' argument; NULL otherwise. */
- const char *(*invalid_arg_for_unprototyped_fn) (const_tree typelist,
- const_tree funcdecl,
- const_tree val);
-
- /* Return an rtx for the return value location of the function
- specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */
- rtx (*function_value) (const_tree ret_type, const_tree fn_decl_or_type,
- bool outgoing);
-
- /* Return an rtx for the argument pointer incoming to the
- current function. */
- rtx (*internal_arg_pointer) (void);
-
- /* Update the current function stack boundary if needed. */
- void (*update_stack_boundary) (void);
-
- /* Handle stack alignment and return an rtx for Dynamic Realign
- Argument Pointer if necessary. */
- rtx (*get_drap_rtx) (void);
-
- /* Return true if all function parameters should be spilled to the
- stack. */
- bool (*allocate_stack_slots_for_args) (void);
-
- } calls;
-
- /* Return the diagnostic message string if conversion from FROMTYPE
- to TOTYPE is not allowed, NULL otherwise. */
- const char *(*invalid_conversion) (const_tree fromtype, const_tree totype);
-
- /* Return the diagnostic message string if the unary operation OP is
- not permitted on TYPE, NULL otherwise. */
- const char *(*invalid_unary_op) (int op, const_tree type);
-
- /* Return the diagnostic message string if the binary operation OP
- is not permitted on TYPE1 and TYPE2, NULL otherwise. */
- const char *(*invalid_binary_op) (int op, const_tree type1, const_tree type2);
-
- /* Return the array of IRA cover classes for the current target. */
- const enum reg_class *(*ira_cover_classes) (void);
-
- /* Return the class for a secondary reload, and fill in extra information. */
- enum reg_class (*secondary_reload) (bool, rtx, enum reg_class,
- enum machine_mode,
- struct secondary_reload_info *);
-
- /* This target hook allows the backend to perform additional
- processing while initializing for variable expansion. */
- void (* expand_to_rtl_hook) (void);
-
- /* This target hook allows the backend to perform additional
- instantiations on rtx that are not actually in insns yet,
- but will be later. */
- void (* instantiate_decls) (void);
-
- /* Return true if is OK to use a hard register REGNO as scratch register
- in peephole2. */
- bool (* hard_regno_scratch_ok) (unsigned int regno);
-
- /* Functions specific to the C family of frontends. */
- struct c {
- /* Return machine mode for non-standard suffix
- or VOIDmode if non-standard suffixes are unsupported. */
- enum machine_mode (*mode_for_suffix) (char);
- } c;
-
- /* Functions specific to the C++ frontend. */
- struct cxx {
- /* Return the integer type used for guard variables. */
- tree (*guard_type) (void);
- /* Return true if only the low bit of the guard should be tested. */
- bool (*guard_mask_bit) (void);
- /* Returns the size of the array cookie for an array of type. */
- tree (*get_cookie_size) (tree);
- /* Returns true if the element size should be stored in the
- array cookie. */
- bool (*cookie_has_size) (void);
- /* Allows backends to perform additional processing when
- deciding if a class should be exported or imported. */
- int (*import_export_class) (tree, int);
- /* Returns true if constructors and destructors return "this". */
- bool (*cdtor_returns_this) (void);
- /* Returns true if the key method for a class can be an inline
- function, so long as it is not declared inline in the class
- itself. Returning true is the behavior required by the Itanium
- C++ ABI. */
- bool (*key_method_may_be_inline) (void);
- /* 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 DECL_VISIBILITY and
- DECL_VISIBILITY_SPECIFIED. */
- void (*determine_class_data_visibility) (tree decl);
- /* 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. */
- bool (*class_data_always_comdat) (void);
- /* Returns true (the default) if the RTTI for the basic types,
- which is always defined in the C++ runtime, should be COMDAT;
- false if it should not be COMDAT. */
- bool (*library_rtti_comdat) (void);
- /* Returns true if __aeabi_atexit should be used to register static
- destructors. */
- bool (*use_aeabi_atexit) (void);
- /* Returns true if target may use atexit in the same manner as
- __cxa_atexit to register static destructors. */
- bool (*use_atexit_for_cxa_atexit) (void);
- /* TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that
- has just been defined. Use this hook to make adjustments to the
- class (eg, tweak visibility or perform any other required
- target modifications). */
- void (*adjust_class_at_definition) (tree type);
- } cxx;
-
- /* Functions and data for emulated TLS support. */
- struct emutls {
- /* Name of the address and common functions. */
- const char *get_address;
- const char *register_common;
-
- /* Prefixes for proxy variable and template. */
- const char *var_section;
- const char *tmpl_section;
-
- /* Prefixes for proxy variable and template. */
- const char *var_prefix;
- const char *tmpl_prefix;
-
- /* Function to generate field definitions of the proxy variable. */
- tree (*var_fields) (tree, tree *);
-
- /* Function to initialize a proxy variable. */
- tree (*var_init) (tree, tree, tree);
-
- /* Whether we are allowed to alter the usual alignment of the
- proxy variable. */
- bool var_align_fixed;
-
- /* Whether we can emit debug information for TLS vars. */
- bool debug_form_tls_address;
- } emutls;
-
- struct target_option_hooks {
- /* Function to validate the attribute((option(...))) strings or NULL. If
- the option is validated, it is assumed that DECL_FUNCTION_SPECIFIC will
- be filled in in the function decl node. */
- bool (*valid_attribute_p) (tree, tree, tree, int);
-
- /* Function to save any extra target state in the target options
- structure. */
- void (*save) (struct cl_target_option *);
-
- /* Function to restore any extra target state from the target options
- structure. */
- void (*restore) (struct cl_target_option *);
-
- /* Function to print any extra target state from the target options
- structure. */
- void (*print) (FILE *, int, struct cl_target_option *);
-
- /* Function to parse arguments to be validated for #pragma option, and to
- change the state if the options are valid. If the first argument is
- NULL, the second argument specifies the default options to use. Return
- true if the options are valid, and set the current state. */
- bool (*pragma_parse) (tree, tree);
-
- /* Function to determine if one function can inline another function. */
- bool (*can_inline_p) (tree, tree);
- } target_option;
-
- /* For targets that need to mark extra registers as live on entry to
- the function, they should define this target hook and set their
- bits in the bitmap passed in. */
- void (*live_on_entry) (bitmap);
-
- /* True if unwinding tables should be generated by default. */
- bool unwind_tables_default;
-
- /* Leave the boolean fields at the end. */
-
- /* True if arbitrary sections are supported. */
- bool have_named_sections;
-
- /* True if we can create zeroed data by switching to a BSS section
- and then using ASM_OUTPUT_SKIP to allocate the space. */
- bool have_switchable_bss_sections;
-
- /* True if "native" constructors and destructors are supported,
- false if we're using collect2 for the job. */
- bool have_ctors_dtors;
-
- /* True if thread-local storage is supported. */
- bool have_tls;
-
- /* True if a small readonly data section is supported. */
- bool have_srodata_section;
-
- /* True if EH frame info sections should be zero-terminated. */
- bool terminate_dw2_eh_frame_info;
-
- /* True if #NO_APP should be emitted at the beginning of
- assembly output. */
- bool file_start_app_off;