1 /* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 2, or (at your option) any
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 In other words, you are welcome to use, share and improve this program.
19 You are forbidden to forbid anyone else to use, share and improve
20 what you give them. Help stamp out software-hoarding! */
22 /* This file contains a data structure that describes a GCC target.
23 At present it is incomplete, but in future it should grow to
24 contain most or all target machine and target O/S specific
27 This structure has its initializer declared in target-def.h in the
28 form of large macro TARGET_INITIALIZER that expands to many smaller
31 The smaller macros each initialize one component of the structure,
32 and each has a default. Each target should have a file that
33 includes target.h and target-def.h, and overrides any inappropriate
34 defaults by undefining the relevant macro and defining a suitable
35 replacement. That file should then contain the definition of
38 struct gcc_target targetm = TARGET_INITIALIZER;
40 Doing things this way allows us to bring together everything that
41 defines a GCC target. By supplying a default that is appropriate
42 to most targets, we can easily add new items without needing to
43 edit dozens of target configuration files. It should also allow us
44 to gradually reduce the amount of conditional compilation that is
45 scattered throughout GCC. */
49 /* Functions that output assembler for the target. */
52 /* Opening and closing parentheses for asm expression grouping. */
53 const char *open_paren, *close_paren;
55 /* Assembler instructions for creating various kinds of integer object. */
63 } aligned_op, unaligned_op;
65 /* Try to output the assembler code for an integer object whose
66 value is given by X. SIZE is the size of the object in bytes and
67 ALIGNED_P indicates whether it is aligned. Return true if
68 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
69 and UNALIGNED_OP are NULL. */
70 bool (* integer) (rtx x, unsigned int size, int aligned_p);
72 /* Output code that will globalize a label. */
73 void (* globalize_label) (FILE *, const char *);
75 /* Output an internal label. */
76 void (* internal_label) (FILE *, const char *, unsigned long);
78 /* Emit an assembler directive to set visibility for the symbol
79 associated with the tree decl. */
80 void (* visibility) (tree, int);
82 /* Output the assembler code for entry to a function. */
83 void (* function_prologue) (FILE *, HOST_WIDE_INT);
85 /* Output the assembler code for end of prologue. */
86 void (* function_end_prologue) (FILE *);
88 /* Output the assembler code for start of epilogue. */
89 void (* function_begin_epilogue) (FILE *);
91 /* Output the assembler code for function exit. */
92 void (* function_epilogue) (FILE *, HOST_WIDE_INT);
94 /* Switch to an arbitrary section NAME with attributes as
95 specified by FLAGS. */
96 void (* named_section) (const char *, unsigned int);
98 /* Switch to the section that holds the exception table. */
99 void (* exception_section) (void);
101 /* Switch to the section that holds the exception frames. */
102 void (* eh_frame_section) (void);
104 /* Select and switch to a section for EXP. It may be a DECL or a
105 constant. RELOC is nonzero if runtime relocations must be applied;
106 bit 1 will be set if the runtime relocations require non-local
107 name resolution. ALIGN is the required alignment of the data. */
108 void (* select_section) (tree, int, unsigned HOST_WIDE_INT);
110 /* Select and switch to a section for X with MODE. ALIGN is
111 the desired alignment of the data. */
112 void (* select_rtx_section) (enum machine_mode, rtx,
113 unsigned HOST_WIDE_INT);
115 /* Select a unique section name for DECL. RELOC is the same as
116 for SELECT_SECTION. */
117 void (* unique_section) (tree, int);
119 /* Output a constructor for a symbol with a given priority. */
120 void (* constructor) (rtx, int);
122 /* Output a destructor for a symbol with a given priority. */
123 void (* destructor) (rtx, int);
125 /* Output the assembler code for a thunk function. THUNK_DECL is the
126 declaration for the thunk function itself, FUNCTION is the decl for
127 the target function. DELTA is an immediate constant offset to be
128 added to THIS. If VCALL_OFFSET is nonzero, the word at
129 *(*this + vcall_offset) should be added to THIS. */
130 void (* output_mi_thunk) (FILE *file, tree thunk_decl,
131 HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
134 /* Determine whether output_mi_thunk would succeed. */
135 /* ??? Ideally, this hook would not exist, and success or failure
136 would be returned from output_mi_thunk directly. But there's
137 too much undo-able setup involved in invoking output_mi_thunk.
138 Could be fixed by making output_mi_thunk emit rtl instead of
139 text to the output file. */
140 bool (* can_output_mi_thunk) (tree thunk_decl, HOST_WIDE_INT delta,
141 HOST_WIDE_INT vcall_offset,
144 /* Output any boilerplate text needed at the beginning of a
146 void (*file_start) (void);
148 /* Output any boilerplate text needed at the end of a
150 void (*file_end) (void);
152 /* Output an assembler pseudo-op to declare a library function name
154 void (*external_libcall) (rtx);
157 /* Functions relating to instruction scheduling. */
160 /* Given the current cost, COST, of an insn, INSN, calculate and
161 return a new cost based on its relationship to DEP_INSN through
162 the dependence LINK. The default is to make no adjustment. */
163 int (* adjust_cost) (rtx insn, rtx link, rtx def_insn, int cost);
165 /* Adjust the priority of an insn as you see fit. Returns the new
167 int (* adjust_priority) (rtx, int);
169 /* Function which returns the maximum number of insns that can be
170 scheduled in the same machine cycle. This must be constant
171 over an entire compilation. The default is 1. */
172 int (* issue_rate) (void);
174 /* Calculate how much this insn affects how many more insns we
175 can emit this cycle. Default is they all cost the same. */
176 int (* variable_issue) (FILE *, int, rtx, int);
178 /* Initialize machine-dependent scheduling code. */
179 void (* md_init) (FILE *, int, int);
181 /* Finalize machine-dependent scheduling code. */
182 void (* md_finish) (FILE *, int);
184 /* Reorder insns in a machine-dependent fashion, in two different
185 places. Default does nothing. */
186 int (* reorder) (FILE *, int, rtx *, int *, int);
187 int (* reorder2) (FILE *, int, rtx *, int *, int);
189 /* The following member value is a pointer to a function called
190 after evaluation forward dependencies of insns in chain given
191 by two parameter values (head and tail correspondingly). */
192 void (* dependencies_evaluation_hook) (rtx, rtx);
194 /* The following member value is a pointer to a function returning
195 nonzero if we should use DFA based scheduling. The default is
196 to use the old pipeline scheduler. */
197 int (* use_dfa_pipeline_interface) (void);
198 /* The values of all the following members are used only for the
199 DFA based scheduler: */
200 /* The values of the following four members are pointers to
201 functions used to simplify the automaton descriptions.
202 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
203 returning insns which are used to change the pipeline hazard
204 recognizer state when the new simulated processor cycle
205 correspondingly starts and finishes. The function defined by
206 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
207 to initialize the corresponding insns. The default values of
208 the memebers result in not changing the automaton state when
209 the new simulated processor cycle correspondingly starts and
211 void (* init_dfa_pre_cycle_insn) (void);
212 rtx (* dfa_pre_cycle_insn) (void);
213 void (* init_dfa_post_cycle_insn) (void);
214 rtx (* dfa_post_cycle_insn) (void);
215 /* The following member value is a pointer to a function returning value
216 which defines how many insns in queue `ready' will we try for
217 multi-pass scheduling. if the member value is nonzero and the
218 function returns positive value, the DFA based scheduler will make
219 multi-pass scheduling for the first cycle. In other words, we will
220 try to choose ready insn which permits to start maximum number of
221 insns on the same cycle. */
222 int (* first_cycle_multipass_dfa_lookahead) (void);
223 /* The following member value is pointer to a function controlling
224 what insns from the ready insn queue will be considered for the
225 multipass insn scheduling. If the hook returns zero for insn
226 passed as the parameter, the insn will be not chosen to be
228 int (* first_cycle_multipass_dfa_lookahead_guard) (rtx);
229 /* The following member value is pointer to a function called by
230 the insn scheduler before issuing insn passed as the third
231 parameter on given cycle. If the hook returns nonzero, the
232 insn is not issued on given processors cycle. Instead of that,
233 the processor cycle is advanced. If the value passed through
234 the last parameter is zero, the insn ready queue is not sorted
235 on the new cycle start as usually. The first parameter passes
236 file for debugging output. The second one passes the scheduler
237 verbose level of the debugging output. The forth and the fifth
238 parameter values are correspondingly processor cycle on which
239 the previous insn has been issued and the current processor
241 int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *);
242 /* The values of the following members are pointers to functions
243 used to improve the first cycle multipass scheduling by
244 inserting nop insns. dfa_scheduler_bubble gives a function
245 returning a nop insn with given index. The indexes start with
246 zero. The function should return NULL if there are no more nop
247 insns with indexes greater than given index. To initialize the
248 nop insn the function given by member
249 init_dfa_scheduler_bubbles is used. The default values of the
250 members result in not inserting nop insns during the multipass
252 void (* init_dfa_bubbles) (void);
253 rtx (* dfa_bubble) (int);
256 /* Given two decls, merge their attributes and return the result. */
257 tree (* merge_decl_attributes) (tree, tree);
259 /* Given two types, merge their attributes and return the result. */
260 tree (* merge_type_attributes) (tree, tree);
262 /* Table of machine attributes and functions to handle them.
264 const struct attribute_spec *attribute_table;
266 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
267 one if they are compatible and two if they are nearly compatible
268 (which causes a warning to be generated). */
269 int (* comp_type_attributes) (tree type1, tree type2);
271 /* Assign default attributes to the newly defined TYPE. */
272 void (* set_default_type_attributes) (tree type);
274 /* Insert attributes on the newly created DECL. */
275 void (* insert_attributes) (tree decl, tree *attributes);
277 /* Return true if FNDECL (which has at least one machine attribute)
278 can be inlined despite its machine attributes, false otherwise. */
279 bool (* function_attribute_inlinable_p) (tree fndecl);
281 /* Return true if bitfields in RECORD_TYPE should follow the
282 Microsoft Visual C++ bitfield layout rules. */
283 bool (* ms_bitfield_layout_p) (tree record_type);
285 /* Set up target-specific built-in functions. */
286 void (* init_builtins) (void);
288 /* Expand a target-specific builtin. */
289 rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget,
290 enum machine_mode mode, int ignore);
292 /* Make any adjustments to libfunc names needed for this target. */
293 void (* init_libfuncs) (void);
295 /* Given a decl, a section name, and whether the decl initializer
296 has relocs, choose attributes for the section. */
297 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
298 unsigned int (* section_type_flags) (tree, const char *, int);
300 /* True if new jumps cannot be created, to replace existing ones or
301 not, at the current point in the compilation. */
302 bool (* cannot_modify_jumps_p) (void);
304 /* Return a register class for which branch target register
305 optimizations should be applied. */
306 int (* branch_target_register_class) (void);
308 /* Return true if branch target register optimizations should include
309 callee-saved registers that are not already live during the current
310 function. AFTER_PE_GEN is true if prologues and epilogues have
311 already been generated. */
312 bool (* branch_target_register_callee_saved) (bool after_pe_gen);
314 /* True if the constant X cannot be placed in the constant pool. */
315 bool (* cannot_force_const_mem) (rtx);
317 /* True if the insn X cannot be duplicated. */
318 bool (* cannot_copy_insn_p) (rtx);
320 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
321 rtx (* delegitimize_address) (rtx);
323 /* True if it is OK to do sibling call optimization for the specified
324 call expression EXP. DECL will be the called function, or NULL if
325 this is an indirect call. */
326 bool (*function_ok_for_sibcall) (tree decl, tree exp);
328 /* True if EXP should be placed in a "small data" section. */
329 bool (* in_small_data_p) (tree);
331 /* True if EXP names an object for which name resolution must resolve
332 to the current module. */
333 bool (* binds_local_p) (tree);
335 /* Do something target-specific to record properties of the DECL into
336 the associated SYMBOL_REF. */
337 void (* encode_section_info) (tree, rtx, int);
339 /* Undo the effects of encode_section_info on the symbol string. */
340 const char * (* strip_name_encoding) (const char *);
342 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
343 bool (* valid_pointer_mode) (enum machine_mode mode);
345 /* True if a vector is opaque. */
346 bool (* vector_opaque_p) (tree);
348 /* Compute a (partial) cost for rtx X. Return true if the complete
349 cost has been computed, and false if subexpressions should be
350 scanned. In either case, *TOTAL contains the cost result. */
351 /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
352 not necessarily defined at this point. */
353 bool (* rtx_costs) (rtx x, int code, int outer_code, int *total);
355 /* Compute the cost of X, used as an address. Never called with
356 invalid addresses. */
357 int (* address_cost) (rtx x);
359 /* Given a register, this hook should return a parallel of registers
360 to represent where to find the register pieces. Define this hook
361 if the register and its mode are represented in Dwarf in
362 non-contiguous locations, or if the register should be
363 represented in more than one register in Dwarf. Otherwise, this
364 hook should return NULL_RTX. */
365 rtx (* dwarf_register_span) (rtx);
367 /* Do machine-dependent code transformations. Called just before
368 delayed-branch scheduling. */
369 void (* machine_dependent_reorg) (void);
371 /* Leave the boolean fields at the end. */
373 /* True if arbitrary sections are supported. */
374 bool have_named_sections;
376 /* True if "native" constructors and destructors are supported,
377 false if we're using collect2 for the job. */
378 bool have_ctors_dtors;
380 /* True if thread-local storage is supported. */
383 /* True if a small readonly data section is supported. */
384 bool have_srodata_section;
386 /* True if EH frame info sections should be zero-terminated. */
387 bool terminate_dw2_eh_frame_info;
389 /* True if #NO_APP should be emitted at the beginning of
391 bool file_start_app_off;
393 /* True if output_file_directive should be called for main_input_filename
394 at the beginning of assembly output. */
395 bool file_start_file_directive;
397 /* Functions relating to calls - argument passing, returns, etc. */
399 bool (*promote_function_args) (tree fntype);
400 bool (*promote_function_return) (tree fntype);
401 bool (*promote_prototypes) (tree fntype);
402 rtx (*struct_value_rtx) (tree fndecl, int incoming);
403 bool (*return_in_memory) (tree type, tree fndecl);
404 rtx (*expand_builtin_saveregs) (void);
405 /* Returns pretend_argument_size. */
406 void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
407 tree type, int *pretend_arg_size, int second_time);
408 bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca);
409 /* Returns true if we should use SETUP_INCOMING_VARARGS and/or
410 STRICT_ARGUMENT_NAMING. */
411 bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca);
415 extern struct gcc_target targetm;