/* Data structure definitions for a generic GCC target. Copyright (C) 2001, 2002, 2003, 2004, 2005 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 Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. In other words, you are welcome to use, share and improve this program. You are forbidden to forbid anyone else to use, share and improve what you give them. Help stamp out software-hoarding! */ /* This file contains a data structure that describes a GCC target. At present it is incomplete, but in future it should grow to contain most or all target machine and target O/S specific information. This structure has its initializer declared in target-def.h in the form of large macro TARGET_INITIALIZER that expands to many smaller macros. The smaller macros each initialize one component of the structure, and each has a default. Each target should have a file that includes target.h and target-def.h, and overrides any inappropriate defaults by undefining the relevant macro and defining a suitable replacement. That file should then contain the definition of "targetm" like so: struct gcc_target targetm = TARGET_INITIALIZER; Doing things this way allows us to bring together everything that defines a GCC target. By supplying a default that is appropriate to most targets, we can easily add new items without needing to edit dozens of target configuration files. It should also allow us to gradually reduce the amount of conditional compilation that is scattered throughout GCC. */ #ifndef GCC_TARGET_H #define GCC_TARGET_H #include "tm.h" #include "insn-modes.h" struct gcc_target { /* Functions that output assembler for the target. */ struct asm_out { /* Opening and closing parentheses for asm expression grouping. */ const char *open_paren, *close_paren; /* Assembler instructions for creating various kinds of integer object. */ const char *byte_op; struct asm_int_op { const char *hi; const char *si; const char *di; const char *ti; } aligned_op, unaligned_op; /* Try to output the assembler code for an integer object whose value is given by X. SIZE is the size of the object in bytes and ALIGNED_P indicates whether it is aligned. Return true if successful. Only handles cases for which BYTE_OP, ALIGNED_OP and UNALIGNED_OP are NULL. */ bool (* integer) (rtx x, unsigned int size, int aligned_p); /* Output code that will globalize a label. */ void (* globalize_label) (FILE *, const char *); /* Output code that will emit a label for unwind info, if this target requires such labels. Second argument is the decl the unwind info is associated with, third is a boolean: true if this is for exception handling, fourth is a boolean: true if this is only a placeholder for an omitted FDE. */ void (* unwind_label) (FILE *, tree, int, int); /* Emit any directives required to unwind this instruction. */ void (* unwind_emit) (FILE *, rtx); /* Output an internal label. */ void (* internal_label) (FILE *, const char *, unsigned long); /* Emit an assembler directive to set visibility for the symbol associated with the tree decl. */ void (* visibility) (tree, int); /* Output the assembler code for entry to a function. */ void (* function_prologue) (FILE *, HOST_WIDE_INT); /* Output the assembler code for end of prologue. */ void (* function_end_prologue) (FILE *); /* Output the assembler code for start of epilogue. */ void (* function_begin_epilogue) (FILE *); /* Output the assembler code for function exit. */ void (* function_epilogue) (FILE *, HOST_WIDE_INT); /* Tell assembler to change to section NAME with attributes FLAGS. If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with which this section is associated. */ void (* named_section) (const char *name, unsigned int flags, tree decl); /* Switch to the section that holds the exception table. */ void (* exception_section) (void); /* Switch to the section that holds the exception frames. */ void (* eh_frame_section) (void); /* Select and switch to a section for EXP. It may be a DECL or a constant. RELOC is nonzero if runtime relocations must be applied; bit 1 will be set if the runtime relocations require non-local name resolution. ALIGN is the required alignment of the data. */ void (* select_section) (tree, int, unsigned HOST_WIDE_INT); /* Select and switch to a section for X with MODE. ALIGN is the desired alignment of the data. */ void (* select_rtx_section) (enum machine_mode, rtx, unsigned HOST_WIDE_INT); /* Select a unique section name for DECL. RELOC is the same as for SELECT_SECTION. */ void (* unique_section) (tree, int); /* Tell assembler to switch to the readonly data section associated with function DECL. */ void (* function_rodata_section) (tree); /* Output a constructor for a symbol with a given priority. */ void (* constructor) (rtx, int); /* Output a destructor for a symbol with a given priority. */ void (* destructor) (rtx, int); /* Output the assembler code for a thunk function. THUNK_DECL is the declaration for the thunk function itself, FUNCTION is the decl for the target function. DELTA is an immediate constant offset to be added to THIS. If VCALL_OFFSET is nonzero, the word at *(*this + vcall_offset) should be added to THIS. */ void (* output_mi_thunk) (FILE *file, tree thunk_decl, HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset, tree function_decl); /* Determine whether output_mi_thunk would succeed. */ /* ??? Ideally, this hook would not exist, and success or failure would be returned from output_mi_thunk directly. But there's too much undo-able setup involved in invoking output_mi_thunk. Could be fixed by making output_mi_thunk emit rtl instead of text to the output file. */ bool (* can_output_mi_thunk) (tree thunk_decl, HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset, tree function_decl); /* Output any boilerplate text needed at the beginning of a translation unit. */ void (*file_start) (void); /* Output any boilerplate text needed at the end of a translation unit. */ void (*file_end) (void); /* Output an assembler pseudo-op to declare a library function name external. */ void (*external_libcall) (rtx); /* Output an assembler directive to mark decl live. This instructs linker to not dead code strip this symbol. */ void (*mark_decl_preserved) (const char *); } asm_out; /* Functions relating to instruction scheduling. */ struct sched { /* Given the current cost, COST, of an insn, INSN, calculate and return a new cost based on its relationship to DEP_INSN through the dependence LINK. The default is to make no adjustment. */ int (* adjust_cost) (rtx insn, rtx link, rtx def_insn, int cost); /* Adjust the priority of an insn as you see fit. Returns the new priority. */ int (* adjust_priority) (rtx, int); /* Function which returns the maximum number of insns that can be scheduled in the same machine cycle. This must be constant over an entire compilation. The default is 1. */ int (* issue_rate) (void); /* Calculate how much this insn affects how many more insns we can emit this cycle. Default is they all cost the same. */ int (* variable_issue) (FILE *, int, rtx, int); /* Initialize machine-dependent scheduling code. */ void (* md_init) (FILE *, int, int); /* Finalize machine-dependent scheduling code. */ void (* md_finish) (FILE *, int); /* Initialize machine-dependent function while scheduling code. */ void (* md_init_global) (FILE *, int, int); /* Finalize machine-dependent function wide scheduling code. */ void (* md_finish_global) (FILE *, int); /* Reorder insns in a machine-dependent fashion, in two different places. Default does nothing. */ int (* reorder) (FILE *, int, rtx *, int *, int); int (* reorder2) (FILE *, int, rtx *, int *, int); /* The following member value is a pointer to a function called after evaluation forward dependencies of insns in chain given by two parameter values (head and tail correspondingly). */ void (* dependencies_evaluation_hook) (rtx, rtx); /* The values of the following four members are pointers to functions used to simplify the automaton descriptions. dfa_pre_cycle_insn and dfa_post_cycle_insn give functions returning insns which are used to change the pipeline hazard recognizer state when the new simulated processor cycle correspondingly starts and finishes. The function defined by init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used to initialize the corresponding insns. The default values of the members result in not changing the automaton state when the new simulated processor cycle correspondingly starts and finishes. */ void (* init_dfa_pre_cycle_insn) (void); rtx (* dfa_pre_cycle_insn) (void); void (* init_dfa_post_cycle_insn) (void); rtx (* dfa_post_cycle_insn) (void); /* The following member value is a pointer to a function returning value which defines how many insns in queue `ready' will we try for multi-pass scheduling. If the member value is nonzero and the function returns positive value, the DFA based scheduler will make multi-pass scheduling for the first cycle. In other words, we will try to choose ready insn which permits to start maximum number of insns on the same cycle. */ int (* first_cycle_multipass_dfa_lookahead) (void); /* The following member value is pointer to a function controlling what insns from the ready insn queue will be considered for the multipass insn scheduling. If the hook returns zero for insn passed as the parameter, the insn will be not chosen to be issued. */ int (* first_cycle_multipass_dfa_lookahead_guard) (rtx); /* The following member value is pointer to a function called by the insn scheduler before issuing insn passed as the third parameter on given cycle. If the hook returns nonzero, the insn is not issued on given processors cycle. Instead of that, the processor cycle is advanced. If the value passed through the last parameter is zero, the insn ready queue is not sorted on the new cycle start as usually. The first parameter passes file for debugging output. The second one passes the scheduler verbose level of the debugging output. The forth and the fifth parameter values are correspondingly processor cycle on which the previous insn has been issued and the current processor cycle. */ int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *); /* The following member value is a pointer to a function called by the insn scheduler. It should return true if there exists a dependence which is considered costly by the target, between the insn passed as the first parameter, and the insn passed as the second parameter. The third parameter is the INSN_DEPEND link that represents the dependence between the two insns. The fourth argument is the cost of the dependence as estimated by the scheduler. The last argument is the distance in cycles between the already scheduled insn (first parameter) and the the second insn (second parameter). */ bool (* is_costly_dependence) (rtx, rtx, rtx, int, int); } sched; /* Functions relating to vectorization. */ struct vectorize { /* The following member value is a pointer to a function called by the vectorizer, and return the decl of the target builtin function. */ tree (* builtin_mask_for_load) (void); } vectorize; /* The initial value of target_flags. */ int default_target_flags; /* Handle target switch CODE (an OPT_* value). ARG is the argument passed to the switch; it is NULL if no argument was. VALUE is the value of ARG if CODE specifies a UInteger option, otherwise it is 1 if the positive form of the switch was used and 0 if the negative form was. Return true if the switch was valid. */ bool (* handle_option) (size_t code, const char *arg, int value); /* Return machine mode for filter value. */ enum machine_mode (* eh_return_filter_mode) (void); /* Given two decls, merge their attributes and return the result. */ tree (* merge_decl_attributes) (tree, tree); /* Given two types, merge their attributes and return the result. */ tree (* merge_type_attributes) (tree, tree); /* Table of machine attributes and functions to handle them. Ignored if NULL. */ const struct attribute_spec *attribute_table; /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible, one if they are compatible and two if they are nearly compatible (which causes a warning to be generated). */ int (* comp_type_attributes) (tree type1, tree type2); /* Assign default attributes to the newly defined TYPE. */ void (* set_default_type_attributes) (tree type); /* Insert attributes on the newly created DECL. */ void (* insert_attributes) (tree decl, tree *attributes); /* Return true if FNDECL (which has at least one machine attribute) can be inlined despite its machine attributes, false otherwise. */ bool (* function_attribute_inlinable_p) (tree fndecl); /* Return true if bitfields in RECORD_TYPE should follow the Microsoft Visual C++ bitfield layout rules. */ bool (* ms_bitfield_layout_p) (tree record_type); /* Return true if anonymous bitfields affect structure alignment. */ bool (* align_anon_bitfield) (void); /* Set up target-specific built-in functions. */ void (* init_builtins) (void); /* Expand a target-specific builtin. */ rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget, enum machine_mode mode, int ignore); /* Fold a target-specific builtin. */ tree (* fold_builtin) (tree fndecl, tree arglist, bool ignore); /* For a vendor-specific fundamental TYPE, return a pointer to a statically-allocated string containing the C++ mangling for TYPE. In all other cases, return NULL. */ const char * (* mangle_fundamental_type) (tree type); /* Make any adjustments to libfunc names needed for this target. */ void (* init_libfuncs) (void); /* Given a decl, a section name, and whether the decl initializer has relocs, choose attributes for the section. */ /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */ unsigned int (* section_type_flags) (tree, const char *, int); /* 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); /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */ rtx (* delegitimize_address) (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); /* True if EXP should be placed in a "small data" section. */ bool (* in_small_data_p) (tree); /* True if EXP names an object for which name resolution must resolve to the current module. */ bool (* binds_local_p) (tree); /* 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); /* 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); /* True if a vector is opaque. */ bool (* vector_opaque_p) (tree); /* 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); /* Compute the cost of X, used as an address. Never called with invalid addresses. */ int (* address_cost) (rtx x); /* 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); /* 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); /* Gimplifies a VA_ARG_EXPR. */ tree (* gimplify_va_arg_expr) (tree valist, tree type, tree *pre_p, tree *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); /* 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) (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); /* Functions relating to calls - argument passing, returns, etc. */ struct calls { bool (*promote_function_args) (tree fntype); bool (*promote_function_return) (tree fntype); bool (*promote_prototypes) (tree fntype); rtx (*struct_value_rtx) (tree fndecl, int incoming); bool (*return_in_memory) (tree type, tree fndecl); bool (*return_in_msb) (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, 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) (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, 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, 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) (tree typelist, tree funcdecl, tree val); } calls; /* 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); /* Returns true if all class data (virtual tables, type info, etc.) should be exported from the current DLL, even when the associated class is not exported. */ bool (*export_class_data) (void); } cxx; /* Leave the boolean fields at the end. */ /* True if arbitrary sections are supported. */ bool have_named_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; /* True if output_file_directive should be called for main_input_filename at the beginning of assembly output. */ bool file_start_file_directive; /* True if #pragma redefine_extname is to be supported. */ bool handle_pragma_redefine_extname; /* True if #pragma extern_prefix is to be supported. */ bool handle_pragma_extern_prefix; /* True if the target is allowed to reorder memory accesses unless synchronization is explicitly requested. */ bool relaxed_ordering; /* Leave the boolean fields at the end. */ }; extern struct gcc_target targetm; #endif /* GCC_TARGET_H */