/* Data structure definitions for a generic GCC target. Copyright (C) 2001, 2002, 2003, 2004 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. */ #include "tm.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 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); /* Switch to an arbitrary section NAME with attributes as specified by FLAGS. */ void (* named_section) (const char *, unsigned int); /* 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); /* 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); } 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); /* 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 following member value is a pointer to a function returning nonzero if we should use DFA based scheduling. The default is to use the old pipeline scheduler. */ int (* use_dfa_pipeline_interface) (void); /* The values of all the following members are used only for the DFA based scheduler: */ /* 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 values of the following members are pointers to functions used to improve the first cycle multipass scheduling by inserting nop insns. dfa_scheduler_bubble gives a function returning a nop insn with given index. The indexes start with zero. The function should return NULL if there are no more nop insns with indexes greater than given index. To initialize the nop insn the function given by member init_dfa_scheduler_bubbles is used. The default values of the members result in not inserting nop insns during the multipass scheduling. */ void (* init_dfa_bubbles) (void); rtx (* dfa_bubble) (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; /* 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); /* 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); /* 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 *); /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */ bool (* valid_pointer_mode) (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); /* 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); /* 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); 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 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); } calls; /* 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; /* Leave the boolean fields at the end. */ }; extern struct gcc_target targetm;