1 /* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 3, or (at your option) any
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; see the file COPYING3. If not see
17 <http://www.gnu.org/licenses/>.
19 In other words, you are welcome to use, share and improve this program.
20 You are forbidden to forbid anyone else to use, share and improve
21 what you give them. Help stamp out software-hoarding! */
24 /* This file contains a data structure that describes a GCC target.
25 At present it is incomplete, but in future it should grow to
26 contain most or all target machine and target O/S specific
29 This structure has its initializer declared in target-def.h in the
30 form of large macro TARGET_INITIALIZER that expands to many smaller
33 The smaller macros each initialize one component of the structure,
34 and each has a default. Each target should have a file that
35 includes target.h and target-def.h, and overrides any inappropriate
36 defaults by undefining the relevant macro and defining a suitable
37 replacement. That file should then contain the definition of
40 struct gcc_target targetm = TARGET_INITIALIZER;
42 Doing things this way allows us to bring together everything that
43 defines a GCC target. By supplying a default that is appropriate
44 to most targets, we can easily add new items without needing to
45 edit dozens of target configuration files. It should also allow us
46 to gradually reduce the amount of conditional compilation that is
47 scattered throughout GCC. */
53 #include "insn-modes.h"
55 /* Types used by the record_gcc_switches() target function. */
58 SWITCH_TYPE_PASSED, /* A switch passed on the command line. */
59 SWITCH_TYPE_ENABLED, /* An option that is currently enabled. */
60 SWITCH_TYPE_DESCRIPTIVE, /* Descriptive text, not a switch or option. */
61 SWITCH_TYPE_LINE_START, /* Please emit any necessary text at the start of a line. */
62 SWITCH_TYPE_LINE_END /* Please emit a line terminator. */
66 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
68 /* An example implementation for ELF targets. Defined in varasm.c */
69 extern int elf_record_gcc_switches (print_switch_type type, const char *);
71 /* Some places still assume that all pointer or address modes are the
72 standard Pmode and ptr_mode. These optimizations become invalid if
73 the target actually supports multiple different modes. For now,
74 we disable such optimizations on such targets, using this function. */
75 extern bool target_default_pointer_address_modes_p (void);
80 /* The struct used by the secondary_reload target hook. */
81 typedef struct secondary_reload_info
83 /* icode is actually an enum insn_code, but we don't want to force every
84 file that includes target.h to include optabs.h . */
86 int extra_cost; /* Cost for using (a) scratch register(s) to be taken
87 into account by copy_cost. */
88 /* The next two members are for the use of the backward
89 compatibility hook. */
90 struct secondary_reload_info *prev_sri;
91 int t_icode; /* Actually an enum insn_code - see above. */
92 } secondary_reload_info;
94 /* This is defined in sched-int.h . */
97 /* This is defined in ddg.h . */
100 /* This is defined in cfgloop.h . */
103 /* Assembler instructions for creating various kinds of integer object. */
113 /* Types of costs for vectorizer cost model. */
114 enum vect_cost_for_stmt
125 cond_branch_not_taken,
130 /* The target structure. This holds all the backend hooks. */
134 /* Functions that output assembler for the target. */
137 /* Opening and closing parentheses for asm expression grouping. */
138 const char *open_paren, *close_paren;
140 /* Assembler instructions for creating various kinds of integer object. */
142 struct asm_int_op aligned_op, unaligned_op;
144 /* Try to output the assembler code for an integer object whose
145 value is given by X. SIZE is the size of the object in bytes and
146 ALIGNED_P indicates whether it is aligned. Return true if
147 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
148 and UNALIGNED_OP are NULL. */
149 bool (* integer) (rtx x, unsigned int size, int aligned_p);
151 /* Output code that will globalize a label. */
152 void (* globalize_label) (FILE *, const char *);
154 /* Output code that will globalize a declaration. */
155 void (* globalize_decl_name) (FILE *, tree);
157 /* Output code that will emit a label for unwind info, if this
158 target requires such labels. Second argument is the decl the
159 unwind info is associated with, third is a boolean: true if
160 this is for exception handling, fourth is a boolean: true if
161 this is only a placeholder for an omitted FDE. */
162 void (* unwind_label) (FILE *, tree, int, int);
164 /* Output code that will emit a label to divide up the exception
166 void (* except_table_label) (FILE *);
168 /* Emit any directives required to unwind this instruction. */
169 void (* unwind_emit) (FILE *, rtx);
171 /* Output an internal label. */
172 void (* internal_label) (FILE *, const char *, unsigned long);
174 /* Output label for the constant. */
175 void (* declare_constant_name) (FILE *, const char *, const_tree,
178 /* Emit a ttype table reference to a typeinfo object. */
179 bool (* ttype) (rtx);
181 /* Emit an assembler directive to set visibility for the symbol
182 associated with the tree decl. */
183 void (* visibility) (tree, int);
185 /* Output the assembler code for entry to a function. */
186 void (* function_prologue) (FILE *, HOST_WIDE_INT);
188 /* Output the assembler code for end of prologue. */
189 void (* function_end_prologue) (FILE *);
191 /* Output the assembler code for start of epilogue. */
192 void (* function_begin_epilogue) (FILE *);
194 /* Output the assembler code for function exit. */
195 void (* function_epilogue) (FILE *, HOST_WIDE_INT);
197 /* Initialize target-specific sections. */
198 void (* init_sections) (void);
200 /* Tell assembler to change to section NAME with attributes FLAGS.
201 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
202 which this section is associated. */
203 void (* named_section) (const char *name, unsigned int flags, tree decl);
205 /* Return a mask describing how relocations should be treated when
206 selecting sections. Bit 1 should be set if global relocations
207 should be placed in a read-write section; bit 0 should be set if
208 local relocations should be placed in a read-write section. */
209 int (*reloc_rw_mask) (void);
211 /* Return a section for EXP. It may be a DECL or a constant. RELOC
212 is nonzero if runtime relocations must be applied; bit 1 will be
213 set if the runtime relocations require non-local name resolution.
214 ALIGN is the required alignment of the data. */
215 section *(* select_section) (tree, int, unsigned HOST_WIDE_INT);
217 /* Return a section for X. MODE is X's mode and ALIGN is its
218 alignment in bits. */
219 section *(* select_rtx_section) (enum machine_mode, rtx,
220 unsigned HOST_WIDE_INT);
222 /* Select a unique section name for DECL. RELOC is the same as
223 for SELECT_SECTION. */
224 void (* unique_section) (tree, int);
226 /* Return the readonly data section associated with function DECL. */
227 section *(* function_rodata_section) (tree);
229 /* Output a constructor for a symbol with a given priority. */
230 void (* constructor) (rtx, int);
232 /* Output a destructor for a symbol with a given priority. */
233 void (* destructor) (rtx, int);
235 /* Output the assembler code for a thunk function. THUNK_DECL is the
236 declaration for the thunk function itself, FUNCTION is the decl for
237 the target function. DELTA is an immediate constant offset to be
238 added to THIS. If VCALL_OFFSET is nonzero, the word at
239 *(*this + vcall_offset) should be added to THIS. */
240 void (* output_mi_thunk) (FILE *file, tree thunk_decl,
241 HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
244 /* Determine whether output_mi_thunk would succeed. */
245 /* ??? Ideally, this hook would not exist, and success or failure
246 would be returned from output_mi_thunk directly. But there's
247 too much undo-able setup involved in invoking output_mi_thunk.
248 Could be fixed by making output_mi_thunk emit rtl instead of
249 text to the output file. */
250 bool (* can_output_mi_thunk) (const_tree thunk_decl, HOST_WIDE_INT delta,
251 HOST_WIDE_INT vcall_offset,
252 const_tree function_decl);
254 /* Output any boilerplate text needed at the beginning of a
256 void (*file_start) (void);
258 /* Output any boilerplate text needed at the end of a
260 void (*file_end) (void);
262 /* Output any boilerplate text needed at the beginning of an
263 LTO output stream. */
264 void (*lto_start) (void);
266 /* Output any boilerplate text needed at the end of an
267 LTO output stream. */
268 void (*lto_end) (void);
270 /* Output any boilerplace text needed at the end of a
271 translation unit before debug and unwind info is emitted. */
272 void (*code_end) (void);
274 /* Output an assembler pseudo-op to declare a library function name
276 void (*external_libcall) (rtx);
278 /* Output an assembler directive to mark decl live. This instructs
279 linker to not dead code strip this symbol. */
280 void (*mark_decl_preserved) (const char *);
282 /* Output a record of the command line switches that have been passed. */
283 print_switch_fn_type record_gcc_switches;
284 /* The name of the section that the example ELF implementation of
285 record_gcc_switches will use to store the information. Target
286 specific versions of record_gcc_switches may or may not use
288 const char * record_gcc_switches_section;
290 /* Output the definition of a section anchor. */
291 void (*output_anchor) (rtx);
293 /* Output a DTP-relative reference to a TLS symbol. */
294 void (*output_dwarf_dtprel) (FILE *file, int size, rtx x);
296 /* Some target machines need to postscan each insn after it is output. */
297 void (*final_postscan_insn) (FILE *, rtx, rtx *, int);
299 /* Emit the trampoline template. This hook may be NULL. */
300 void (*trampoline_template) (FILE *);
302 /* Emit a machine-specific insn operand. */
303 void (*print_operand) (FILE *, rtx, int);
305 /* Emit a machine-specific memory address. */
306 void (*print_operand_address) (FILE *, rtx);
308 /* Determine whether CODE is a valid punctuation character for the
309 `print_operand' hook. */
310 bool (*print_operand_punct_valid_p)(unsigned char code);
313 /* Functions relating to instruction scheduling. */
316 /* Given the current cost, COST, of an insn, INSN, calculate and
317 return a new cost based on its relationship to DEP_INSN through
318 the dependence LINK. The default is to make no adjustment. */
319 int (* adjust_cost) (rtx insn, rtx link, rtx dep_insn, int cost);
321 /* Adjust the priority of an insn as you see fit. Returns the new
323 int (* adjust_priority) (rtx, int);
325 /* Function which returns the maximum number of insns that can be
326 scheduled in the same machine cycle. This must be constant
327 over an entire compilation. The default is 1. */
328 int (* issue_rate) (void);
330 /* Calculate how much this insn affects how many more insns we
331 can emit this cycle. Default is they all cost the same. */
332 int (* variable_issue) (FILE *, int, rtx, int);
334 /* Initialize machine-dependent scheduling code. */
335 void (* md_init) (FILE *, int, int);
337 /* Finalize machine-dependent scheduling code. */
338 void (* md_finish) (FILE *, int);
340 /* Initialize machine-dependent function wide scheduling code. */
341 void (* md_init_global) (FILE *, int, int);
343 /* Finalize machine-dependent function wide scheduling code. */
344 void (* md_finish_global) (FILE *, int);
346 /* Reorder insns in a machine-dependent fashion, in two different
347 places. Default does nothing. */
348 int (* reorder) (FILE *, int, rtx *, int *, int);
349 int (* reorder2) (FILE *, int, rtx *, int *, int);
351 /* The following member value is a pointer to a function called
352 after evaluation forward dependencies of insns in chain given
353 by two parameter values (head and tail correspondingly). */
354 void (* dependencies_evaluation_hook) (rtx, rtx);
356 /* The values of the following four members are pointers to
357 functions used to simplify the automaton descriptions.
358 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
359 returning insns which are used to change the pipeline hazard
360 recognizer state when the new simulated processor cycle
361 correspondingly starts and finishes. The function defined by
362 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
363 to initialize the corresponding insns. The default values of
364 the members result in not changing the automaton state when
365 the new simulated processor cycle correspondingly starts and
367 void (* init_dfa_pre_cycle_insn) (void);
368 rtx (* dfa_pre_cycle_insn) (void);
369 void (* init_dfa_post_cycle_insn) (void);
370 rtx (* dfa_post_cycle_insn) (void);
372 /* The values of the following two members are pointers to
373 functions used to simplify the automaton descriptions.
374 dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called
375 immediately before and after cycle is advanced. */
376 void (* dfa_pre_advance_cycle) (void);
377 void (* dfa_post_advance_cycle) (void);
379 /* The following member value is a pointer to a function returning value
380 which defines how many insns in queue `ready' will we try for
381 multi-pass scheduling. If the member value is nonzero and the
382 function returns positive value, the DFA based scheduler will make
383 multi-pass scheduling for the first cycle. In other words, we will
384 try to choose ready insn which permits to start maximum number of
385 insns on the same cycle. */
386 int (* first_cycle_multipass_dfa_lookahead) (void);
388 /* The following member value is pointer to a function controlling
389 what insns from the ready insn queue will be considered for the
390 multipass insn scheduling. If the hook returns zero for insn
391 passed as the parameter, the insn will be not chosen to be
393 int (* first_cycle_multipass_dfa_lookahead_guard) (rtx);
395 /* The following member value is pointer to a function called by
396 the insn scheduler before issuing insn passed as the third
397 parameter on given cycle. If the hook returns nonzero, the
398 insn is not issued on given processors cycle. Instead of that,
399 the processor cycle is advanced. If the value passed through
400 the last parameter is zero, the insn ready queue is not sorted
401 on the new cycle start as usually. The first parameter passes
402 file for debugging output. The second one passes the scheduler
403 verbose level of the debugging output. The forth and the fifth
404 parameter values are correspondingly processor cycle on which
405 the previous insn has been issued and the current processor
407 int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *);
409 /* The following member value is a pointer to a function called by the
410 insn scheduler. It should return true if there exists a dependence
411 which is considered costly by the target, between the insn
412 DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP). The first parameter is
413 the dep that represents the dependence between the two insns. The
414 second argument is the cost of the dependence as estimated by
415 the scheduler. The last argument is the distance in cycles
416 between the already scheduled insn (first parameter) and the
417 second insn (second parameter). */
418 bool (* is_costly_dependence) (struct _dep *_dep, int, int);
420 /* Given the current cost, COST, of an insn, INSN, calculate and
421 return a new cost based on its relationship to DEP_INSN through the
422 dependence of type DEP_TYPE. The default is to make no adjustment. */
423 int (* adjust_cost_2) (rtx insn, int, rtx dep_insn, int cost, int dw);
425 /* The following member value is a pointer to a function called
426 by the insn scheduler. This hook is called to notify the backend
427 that new instructions were emitted. */
428 void (* h_i_d_extended) (void);
430 /* Next 5 functions are for multi-point scheduling. */
432 /* Allocate memory for scheduler context. */
433 void *(* alloc_sched_context) (void);
435 /* Fills the context from the local machine scheduler context. */
436 void (* init_sched_context) (void *, bool);
438 /* Sets local machine scheduler context to a saved value. */
439 void (* set_sched_context) (void *);
441 /* Clears a scheduler context so it becomes like after init. */
442 void (* clear_sched_context) (void *);
444 /* Frees the scheduler context. */
445 void (* free_sched_context) (void *);
447 /* The following member value is a pointer to a function called
448 by the insn scheduler.
449 The first parameter is an instruction, the second parameter is the type
450 of the requested speculation, and the third parameter is a pointer to the
451 speculative pattern of the corresponding type (set if return value == 1).
453 -1, if there is no pattern, that will satisfy the requested speculation
455 0, if current pattern satisfies the requested speculation type,
456 1, if pattern of the instruction should be changed to the newly
458 int (* speculate_insn) (rtx, int, rtx *);
460 /* The following member value is a pointer to a function called
461 by the insn scheduler. It should return true if the check instruction
462 passed as the parameter needs a recovery block. */
463 bool (* needs_block_p) (int);
465 /* The following member value is a pointer to a function called
466 by the insn scheduler. It should return a pattern for the check
468 The first parameter is a speculative instruction, the second parameter
469 is the label of the corresponding recovery block (or null, if it is a
470 simple check). If the mutation of the check is requested (e.g. from
471 ld.c to chk.a), the third parameter is true - in this case the first
472 parameter is the previous check. */
473 rtx (* gen_spec_check) (rtx, rtx, int);
475 /* The following member value is a pointer to a function controlling
476 what insns from the ready insn queue will be considered for the
477 multipass insn scheduling. If the hook returns zero for the insn
478 passed as the parameter, the insn will not be chosen to be
479 issued. This hook is used to discard speculative instructions,
480 that stand at the first position of the ready list. */
481 bool (* first_cycle_multipass_dfa_lookahead_guard_spec) (const_rtx);
483 /* The following member value is a pointer to a function that provides
484 information about the speculation capabilities of the target.
485 The parameter is a pointer to spec_info variable. */
486 void (* set_sched_flags) (struct spec_info_def *);
488 /* Return speculation types of the instruction passed as the parameter. */
489 int (* get_insn_spec_ds) (rtx);
491 /* Return speculation types that are checked for the instruction passed as
493 int (* get_insn_checked_ds) (rtx);
495 /* Return bool if rtx scanning should just skip current layer and
496 advance to the inner rtxes. */
497 bool (* skip_rtx_p) (const_rtx);
499 /* The following member value is a pointer to a function that provides
500 information about the target resource-based lower bound which is
501 used by the swing modulo scheduler. The parameter is a pointer
503 int (* sms_res_mii) (struct ddg *);
506 /* Functions relating to vectorization. */
509 /* The following member value is a pointer to a function called
510 by the vectorizer, and return the decl of the target builtin
512 tree (* builtin_mask_for_load) (void);
514 /* Returns a code for builtin that realizes vectorized version of
515 function, or NULL_TREE if not available. */
516 tree (* builtin_vectorized_function) (tree, tree, tree);
518 /* Returns a function declaration for a builtin that realizes the
519 vector conversion, or NULL_TREE if not available. */
520 tree (* builtin_conversion) (unsigned, tree, tree);
522 /* Target builtin that implements vector widening multiplication.
523 builtin_mul_widen_eve computes the element-by-element products
524 for the even elements, and builtin_mul_widen_odd computes the
525 element-by-element products for the odd elements. */
526 tree (* builtin_mul_widen_even) (tree);
527 tree (* builtin_mul_widen_odd) (tree);
529 /* Cost of different vector/scalar statements in vectorization cost
531 int (* builtin_vectorization_cost) (enum vect_cost_for_stmt);
533 /* Return true if vector alignment is reachable (by peeling N
534 iterations) for the given type. */
535 bool (* vector_alignment_reachable) (const_tree, bool);
537 /* Target builtin that implements vector permute. */
538 tree (* builtin_vec_perm) (tree, tree*);
540 /* Return true if a vector created for builtin_vec_perm is valid. */
541 bool (* builtin_vec_perm_ok) (tree, tree);
543 /* Return true if the target supports misaligned store/load of a
544 specific factor denoted in the third parameter. The last parameter
545 is true if the access is defined in a packed struct. */
546 bool (* builtin_support_vector_misalignment) (enum machine_mode,
547 const_tree, int, bool);
550 /* The initial value of target_flags. */
551 int default_target_flags;
553 /* Allow target specific overriding of option settings after options have
554 been changed by an attribute or pragma or when it is reset at the
555 end of the code affected by an attribute or pragma. */
556 void (* override_options_after_change) (void);
558 /* Handle target switch CODE (an OPT_* value). ARG is the argument
559 passed to the switch; it is NULL if no argument was. VALUE is the
560 value of ARG if CODE specifies a UInteger option, otherwise it is
561 1 if the positive form of the switch was used and 0 if the negative
562 form was. Return true if the switch was valid. */
563 bool (* handle_option) (size_t code, const char *arg, int value);
565 /* Handle target-specific parts of specifying -Ofast. */
566 void (* handle_ofast) (void);
568 /* Display extra, target specific information in response to a
569 --target-help switch. */
570 void (* target_help) (void);
572 /* Return machine mode for filter value. */
573 enum machine_mode (* eh_return_filter_mode) (void);
575 /* Return machine mode for libgcc expanded cmp instructions. */
576 enum machine_mode (* libgcc_cmp_return_mode) (void);
578 /* Return machine mode for libgcc expanded shift instructions. */
579 enum machine_mode (* libgcc_shift_count_mode) (void);
581 /* Return machine mode to be used for _Unwind_Word type. */
582 enum machine_mode (* unwind_word_mode) (void);
584 /* Given two decls, merge their attributes and return the result. */
585 tree (* merge_decl_attributes) (tree, tree);
587 /* Given two types, merge their attributes and return the result. */
588 tree (* merge_type_attributes) (tree, tree);
590 /* Table of machine attributes and functions to handle them.
592 const struct attribute_spec *attribute_table;
594 /* Return true iff attribute NAME expects a plain identifier as its first
596 bool (*attribute_takes_identifier_p) (const_tree name);
598 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
599 one if they are compatible and two if they are nearly compatible
600 (which causes a warning to be generated). */
601 int (* comp_type_attributes) (const_tree type1, const_tree type2);
603 /* Assign default attributes to the newly defined TYPE. */
604 void (* set_default_type_attributes) (tree type);
606 /* Insert attributes on the newly created DECL. */
607 void (* insert_attributes) (tree decl, tree *attributes);
609 /* Return true if FNDECL (which has at least one machine attribute)
610 can be inlined despite its machine attributes, false otherwise. */
611 bool (* function_attribute_inlinable_p) (const_tree fndecl);
613 /* Return true if bitfields in RECORD_TYPE should follow the
614 Microsoft Visual C++ bitfield layout rules. */
615 bool (* ms_bitfield_layout_p) (const_tree record_type);
617 /* True if the target supports decimal floating point. */
618 bool (* decimal_float_supported_p) (void);
620 /* True if the target supports fixed-point. */
621 bool (* fixed_point_supported_p) (void);
623 /* Return true if anonymous bitfields affect structure alignment. */
624 bool (* align_anon_bitfield) (void);
626 /* Return true if volatile bitfields should use the narrowest type possible.
627 Return false if they should use the container type. */
628 bool (* narrow_volatile_bitfield) (void);
630 /* Set up target-specific built-in functions. */
631 void (* init_builtins) (void);
633 /* Initialize (if INITIALIZE_P is true) and return the target-specific
634 built-in function decl for CODE.
635 Return NULL if that is not possible. Return error_mark_node if CODE
636 is outside of the range of valid target builtin function codes. */
637 tree (* builtin_decl) (unsigned code, bool initialize_p);
639 /* Expand a target-specific builtin. */
640 rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget,
641 enum machine_mode mode, int ignore);
643 /* Select a replacement for a target-specific builtin. This is done
644 *before* regular type checking, and so allows the target to
645 implement a crude form of function overloading. The result is a
646 complete expression that implements the operation. PARAMS really
647 has type VEC(tree,gc)*, but we don't want to include tree.h
649 tree (*resolve_overloaded_builtin) (unsigned int /*location_t*/,
650 tree decl, void *params);
652 /* Fold a target-specific builtin. */
653 tree (* fold_builtin) (tree fndecl, int nargs, tree *argp, bool ignore);
655 /* Returns a code for a target-specific builtin that implements
656 reciprocal of the function, or NULL_TREE if not available. */
657 tree (* builtin_reciprocal) (unsigned, bool, bool);
659 /* For a vendor-specific TYPE, return a pointer to a statically-allocated
660 string containing the C++ mangling for TYPE. In all other cases, return
662 const char * (* mangle_type) (const_tree type);
664 /* Make any adjustments to libfunc names needed for this target. */
665 void (* init_libfuncs) (void);
667 /* Given a decl, a section name, and whether the decl initializer
668 has relocs, choose attributes for the section. */
669 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
670 unsigned int (* section_type_flags) (tree, const char *, int);
672 /* True if new jumps cannot be created, to replace existing ones or
673 not, at the current point in the compilation. */
674 bool (* cannot_modify_jumps_p) (void);
676 /* Return a register class for which branch target register
677 optimizations should be applied. */
678 enum reg_class (* branch_target_register_class) (void);
680 /* Return true if branch target register optimizations should include
681 callee-saved registers that are not already live during the current
682 function. AFTER_PE_GEN is true if prologues and epilogues have
683 already been generated. */
684 bool (* branch_target_register_callee_saved) (bool after_pe_gen);
686 /* Return true if the target supports conditional execution. */
687 bool (* have_conditional_execution) (void);
689 /* Return a new value for loop unroll size. */
690 unsigned (* loop_unroll_adjust) (unsigned nunroll, struct loop *loop);
692 /* True if the constant X cannot be placed in the constant pool. */
693 bool (* cannot_force_const_mem) (rtx);
695 /* True if the insn X cannot be duplicated. */
696 bool (* cannot_copy_insn_p) (rtx);
698 /* True if X is considered to be commutative. */
699 bool (* commutative_p) (const_rtx, int);
701 /* True if ADDR is an address-expression whose effect depends
702 on the mode of the memory reference it is used in. */
703 bool (* mode_dependent_address_p) (const_rtx addr);
705 /* Given an invalid address X for a given machine mode, try machine-specific
706 ways to make it legitimate. Return X or an invalid address on failure. */
707 rtx (* legitimize_address) (rtx, rtx, enum machine_mode);
709 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
710 rtx (* delegitimize_address) (rtx);
712 /* Given an address RTX, say whether it is valid. */
713 bool (* legitimate_address_p) (enum machine_mode, rtx, bool);
715 /* True if the given constant can be put into an object_block. */
716 bool (* use_blocks_for_constant_p) (enum machine_mode, const_rtx);
718 /* The minimum and maximum byte offsets for anchored addresses. */
719 HOST_WIDE_INT min_anchor_offset;
720 HOST_WIDE_INT max_anchor_offset;
722 /* True if section anchors can be used to access the given symbol. */
723 bool (* use_anchors_for_symbol_p) (const_rtx);
725 /* True if it is OK to do sibling call optimization for the specified
726 call expression EXP. DECL will be the called function, or NULL if
727 this is an indirect call. */
728 bool (*function_ok_for_sibcall) (tree decl, tree exp);
730 /* Establish appropriate back-end context for processing the function
731 FNDECL. The argument might be NULL to indicate processing at top
732 level, outside of any function scope. */
733 void (*set_current_function) (tree fndecl);
735 /* True if EXP should be placed in a "small data" section. */
736 bool (* in_small_data_p) (const_tree);
738 /* True if EXP names an object for which name resolution must resolve
739 to the current executable or shared library. */
740 bool (* binds_local_p) (const_tree);
742 /* Modify and return the identifier of a DECL's external name,
743 originally identified by ID, as required by the target,
744 (eg, append @nn to windows32 stdcall function names).
745 The default is to return ID without modification. */
746 tree (* mangle_decl_assembler_name) (tree decl, tree id);
748 /* Do something target-specific to record properties of the DECL into
749 the associated SYMBOL_REF. */
750 void (* encode_section_info) (tree, rtx, int);
752 /* Undo the effects of encode_section_info on the symbol string. */
753 const char * (* strip_name_encoding) (const char *);
755 /* If shift optabs for MODE are known to always truncate the shift count,
756 return the mask that they apply. Return 0 otherwise. */
757 unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode);
759 /* Return the number of divisions in the given MODE that should be present,
760 so that it is profitable to turn the division into a multiplication by
762 unsigned int (* min_divisions_for_recip_mul) (enum machine_mode mode);
764 /* If the representation of integral MODE is such that values are
765 always sign-extended to a wider mode MODE_REP then return
766 SIGN_EXTEND. Return UNKNOWN otherwise. */
767 /* Note that the return type ought to be RTX_CODE, but that's not
768 necessarily defined at this point. */
769 int (* mode_rep_extended) (enum machine_mode mode,
770 enum machine_mode mode_rep);
772 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
773 bool (* valid_pointer_mode) (enum machine_mode mode);
775 /* Support for named address spaces. */
777 /* MODE to use for a pointer into another address space. */
778 enum machine_mode (* pointer_mode) (addr_space_t);
780 /* MODE to use for an address in another address space. */
781 enum machine_mode (* address_mode) (addr_space_t);
783 /* True if MODE is valid for a pointer in __attribute__((mode("MODE")))
784 in another address space. */
785 bool (* valid_pointer_mode) (enum machine_mode, addr_space_t);
787 /* True if an address is a valid memory address to a given named address
788 space for a given mode. */
789 bool (* legitimate_address_p) (enum machine_mode, rtx, bool, addr_space_t);
791 /* Return an updated address to convert an invalid pointer to a named
792 address space to a valid one. If NULL_RTX is returned use machine
793 independent methods to make the address valid. */
794 rtx (* legitimize_address) (rtx, rtx, enum machine_mode, addr_space_t);
796 /* True if one named address space is a subset of another named address. */
797 bool (* subset_p) (addr_space_t, addr_space_t);
799 /* Function to convert an rtl expression from one address space to
801 rtx (* convert) (rtx, tree, tree);
805 /* True if MODE is valid for the target. By "valid", we mean able to
806 be manipulated in non-trivial ways. In particular, this means all
807 the arithmetic is supported. */
808 bool (* scalar_mode_supported_p) (enum machine_mode mode);
810 /* Similarly for vector modes. "Supported" here is less strict. At
811 least some operations are supported; need to check optabs or builtins
812 for further details. */
813 bool (* vector_mode_supported_p) (enum machine_mode mode);
815 /* Compute cost of moving data from a register of class FROM to one of
817 int (* register_move_cost) (enum machine_mode, enum reg_class,
820 /* Compute cost of moving registers to/from memory. */
821 int (* memory_move_cost) (enum machine_mode, enum reg_class, bool);
823 /* True for MODE if the target expects that registers in this mode will
824 be allocated to registers in a small register class. The compiler is
825 allowed to use registers explicitly used in the rtl as spill registers
826 but it should prevent extending the lifetime of these registers. */
827 bool (* small_register_classes_for_mode_p) (enum machine_mode mode);
829 /* Compute a (partial) cost for rtx X. Return true if the complete
830 cost has been computed, and false if subexpressions should be
831 scanned. In either case, *TOTAL contains the cost result. */
832 /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
833 not necessarily defined at this point. */
834 bool (* rtx_costs) (rtx x, int code, int outer_code, int *total, bool speed);
836 /* Compute the cost of X, used as an address. Never called with
837 invalid addresses. */
838 int (* address_cost) (rtx x, bool speed);
840 /* Return where to allocate pseudo for a given hard register initial
842 rtx (* allocate_initial_value) (rtx x);
844 /* Return nonzero if evaluating UNSPEC[_VOLATILE] X might cause a trap.
845 FLAGS has the same meaning as in rtlanal.c: may_trap_p_1. */
846 int (* unspec_may_trap_p) (const_rtx x, unsigned flags);
848 /* Given a register, this hook should return a parallel of registers
849 to represent where to find the register pieces. Define this hook
850 if the register and its mode are represented in Dwarf in
851 non-contiguous locations, or if the register should be
852 represented in more than one register in Dwarf. Otherwise, this
853 hook should return NULL_RTX. */
854 rtx (* dwarf_register_span) (rtx);
856 /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
857 entries not corresponding directly to registers below
858 FIRST_PSEUDO_REGISTER, this hook should generate the necessary
859 code, given the address of the table. */
860 void (* init_dwarf_reg_sizes_extra) (tree);
862 /* Fetch the fixed register(s) which hold condition codes, for
863 targets where it makes sense to look for duplicate assignments to
864 the condition codes. This should return true if there is such a
865 register, false otherwise. The arguments should be set to the
866 fixed register numbers. Up to two condition code registers are
867 supported. If there is only one for this target, the int pointed
868 at by the second argument should be set to -1. */
869 bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *);
871 /* If two condition code modes are compatible, return a condition
872 code mode which is compatible with both, such that a comparison
873 done in the returned mode will work for both of the original
874 modes. If the condition code modes are not compatible, return
876 enum machine_mode (* cc_modes_compatible) (enum machine_mode,
879 /* Do machine-dependent code transformations. Called just before
880 delayed-branch scheduling. */
881 void (* machine_dependent_reorg) (void);
883 /* Create the __builtin_va_list type. */
884 tree (* build_builtin_va_list) (void);
886 /* Enumerate the va list variants. */
887 int (* enum_va_list) (int, const char **, tree *);
889 /* Get the cfun/fndecl calling abi __builtin_va_list type. */
890 tree (* fn_abi_va_list) (tree);
892 /* Get the __builtin_va_list type dependent on input type. */
893 tree (* canonical_va_list_type) (tree);
895 /* Expand the __builtin_va_start builtin. */
896 void (* expand_builtin_va_start) (tree valist, rtx nextarg);
898 /* Gimplifies a VA_ARG_EXPR. */
899 tree (* gimplify_va_arg_expr) (tree valist, tree type, gimple_seq *pre_p,
902 /* Validity-checking routines for PCH files, target-specific.
903 get_pch_validity returns a pointer to the data to be stored,
904 and stores the size in its argument. pch_valid_p gets the same
905 information back and returns NULL if the PCH is valid,
906 or an error message if not.
908 void * (* get_pch_validity) (size_t *);
909 const char * (* pch_valid_p) (const void *, size_t);
911 /* If nonnull, this function checks whether a PCH file with the
912 given set of target flags can be used. It returns NULL if so,
913 otherwise it returns an error message. */
914 const char *(*check_pch_target_flags) (int);
916 /* True if the compiler should give an enum type only as many
917 bytes as it takes to represent the range of possible values of
919 bool (* default_short_enums) (void);
921 /* This target hook returns an rtx that is used to store the address
922 of the current frame into the built-in setjmp buffer. */
923 rtx (* builtin_setjmp_frame_value) (void);
925 /* This target hook should add STRING_CST trees for any hard regs
926 the port wishes to automatically clobber for an asm. */
927 tree (* md_asm_clobbers) (tree, tree, tree);
929 /* This target hook allows the backend to specify a calling convention
930 in the debug information. This function actually returns an
931 enum dwarf_calling_convention, but because of forward declarations
932 and not wanting to include dwarf2.h everywhere target.h is included
933 the function is being declared as an int. */
934 int (* dwarf_calling_convention) (const_tree);
936 /* This target hook allows the backend to emit frame-related insns that
937 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info
938 engine will invoke it on insns of the form
939 (set (reg) (unspec [...] UNSPEC_INDEX))
941 (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
942 to let the backend emit the call frame instructions. */
943 void (* dwarf_handle_frame_unspec) (const char *, rtx, int);
945 /* Perform architecture specific checking of statements gimplified
946 from VA_ARG_EXPR. STMT is the statement. Returns true if the statement
947 doesn't need to be checked for va_list references. */
948 bool (* stdarg_optimize_hook) (struct stdarg_info *ai, const_gimple stmt);
950 /* This target hook allows the operating system to override the DECL
951 that represents the external variable that contains the stack
952 protection guard variable. The type of this DECL is ptr_type_node. */
953 tree (* stack_protect_guard) (void);
955 /* This target hook allows the operating system to override the CALL_EXPR
956 that is invoked when a check vs the guard variable fails. */
957 tree (* stack_protect_fail) (void);
959 /* Returns NULL if target supports the insn within a doloop block,
960 otherwise it returns an error message. */
961 const char * (*invalid_within_doloop) (const_rtx);
963 /* DECL is a variable or function with __attribute__((dllimport))
964 specified. Use this hook if the target needs to add extra validation
965 checks to handle_dll_attribute (). */
966 bool (* valid_dllimport_attribute_p) (const_tree decl);
968 /* If non-zero, align constant anchors in CSE to a multiple of this
970 unsigned HOST_WIDE_INT const_anchor;
972 /* Functions relating to calls - argument passing, returns, etc. */
974 enum machine_mode (*promote_function_mode) (const_tree type,
975 enum machine_mode mode,
979 bool (*promote_prototypes) (const_tree fntype);
980 rtx (*struct_value_rtx) (tree fndecl, int incoming);
981 bool (*return_in_memory) (const_tree type, const_tree fndecl);
982 bool (*return_in_msb) (const_tree type);
984 /* Return true if a parameter must be passed by reference. TYPE may
985 be null if this is a libcall. CA may be null if this query is
986 from __builtin_va_arg. */
987 bool (*pass_by_reference) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
988 const_tree type, bool named_arg);
990 rtx (*expand_builtin_saveregs) (void);
991 /* Returns pretend_argument_size. */
992 void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
993 tree type, int *pretend_arg_size,
995 bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca);
996 /* Returns true if we should use
997 targetm.calls.setup_incoming_varargs() and/or
998 targetm.calls.strict_argument_naming(). */
999 bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca);
1001 /* Given a complex type T, return true if a parameter of type T
1002 should be passed as two scalars. */
1003 bool (* split_complex_arg) (const_tree type);
1005 /* Return true if type T, mode MODE, may not be passed in registers,
1006 but must be passed on the stack. */
1007 /* ??? This predicate should be applied strictly after pass-by-reference.
1008 Need audit to verify that this is the case. */
1009 bool (* must_pass_in_stack) (enum machine_mode mode, const_tree t);
1011 /* Return true if type TYPE, mode MODE, which is passed by reference,
1012 should have the object copy generated by the callee rather than
1013 the caller. It is never called for TYPE requiring constructors. */
1014 bool (* callee_copies) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1015 const_tree type, bool named);
1017 /* Return zero for arguments passed entirely on the stack or entirely
1018 in registers. If passed in both, return the number of bytes passed
1019 in registers; the balance is therefore passed on the stack. */
1020 int (* arg_partial_bytes) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1021 tree type, bool named);
1023 /* Return the diagnostic message string if function without a prototype
1024 is not allowed for this 'val' argument; NULL otherwise. */
1025 const char *(*invalid_arg_for_unprototyped_fn) (const_tree typelist,
1026 const_tree funcdecl,
1029 /* Return an rtx for the return value location of the function
1030 specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */
1031 rtx (*function_value) (const_tree ret_type, const_tree fn_decl_or_type,
1034 /* Return the rtx for the result of a libcall of mode MODE,
1035 calling the function FN_NAME. */
1036 rtx (*libcall_value) (enum machine_mode, const_rtx);
1038 /* Return true if REGNO is a possible register number for
1039 a function value as seen by the caller. */
1040 bool (*function_value_regno_p) (const unsigned int);
1042 /* Return an rtx for the argument pointer incoming to the
1043 current function. */
1044 rtx (*internal_arg_pointer) (void);
1046 /* Update the current function stack boundary if needed. */
1047 void (*update_stack_boundary) (void);
1049 /* Handle stack alignment and return an rtx for Dynamic Realign
1050 Argument Pointer if necessary. */
1051 rtx (*get_drap_rtx) (void);
1053 /* Return true if all function parameters should be spilled to the
1055 bool (*allocate_stack_slots_for_args) (void);
1057 /* Return an rtx for the static chain for FNDECL. If INCOMING_P is true,
1058 then it should be for the callee; otherwise for the caller. */
1059 rtx (*static_chain) (const_tree fndecl, bool incoming_p);
1061 /* Fill in the trampoline at MEM with a call to FNDECL and a
1062 static chain value of CHAIN. */
1063 void (*trampoline_init) (rtx mem, tree fndecl, rtx chain);
1065 /* Adjust the address of the trampoline in a target-specific way. */
1066 rtx (*trampoline_adjust_address) (rtx addr);
1069 /* Return the diagnostic message string if conversion from FROMTYPE
1070 to TOTYPE is not allowed, NULL otherwise. */
1071 const char *(*invalid_conversion) (const_tree fromtype, const_tree totype);
1073 /* Return the diagnostic message string if the unary operation OP is
1074 not permitted on TYPE, NULL otherwise. */
1075 const char *(*invalid_unary_op) (int op, const_tree type);
1077 /* Return the diagnostic message string if the binary operation OP
1078 is not permitted on TYPE1 and TYPE2, NULL otherwise. */
1079 const char *(*invalid_binary_op) (int op, const_tree type1, const_tree type2);
1081 /* Return the diagnostic message string if TYPE is not valid as a
1082 function parameter type, NULL otherwise. */
1083 const char *(*invalid_parameter_type) (const_tree type);
1085 /* Return the diagnostic message string if TYPE is not valid as a
1086 function return type, NULL otherwise. */
1087 const char *(*invalid_return_type) (const_tree type);
1089 /* If values of TYPE are promoted to some other type when used in
1090 expressions (analogous to the integer promotions), return that type,
1091 or NULL_TREE otherwise. */
1092 tree (*promoted_type) (const_tree type);
1094 /* Convert EXPR to TYPE, if target-specific types with special conversion
1095 rules are involved. Return the converted expression, or NULL to apply
1096 the standard conversion rules. */
1097 tree (*convert_to_type) (tree type, tree expr);
1099 /* Return the array of IRA cover classes for the current target. */
1100 const enum reg_class *(*ira_cover_classes) (void);
1102 /* Return the class for a secondary reload, and fill in extra information. */
1103 enum reg_class (*secondary_reload) (bool, rtx, enum reg_class,
1105 secondary_reload_info *);
1107 /* This target hook allows the backend to perform additional
1108 processing while initializing for variable expansion. */
1109 void (* expand_to_rtl_hook) (void);
1111 /* This target hook allows the backend to perform additional
1112 instantiations on rtx that are not actually in insns yet,
1113 but will be later. */
1114 void (* instantiate_decls) (void);
1116 /* Return true if is OK to use a hard register REGNO as scratch register
1118 bool (* hard_regno_scratch_ok) (unsigned int regno);
1120 /* Return the smallest number of different values for which it is best to
1121 use a jump-table instead of a tree of conditional branches. */
1122 unsigned int (* case_values_threshold) (void);
1124 /* Retutn true if a function must have and use a frame pointer. */
1125 bool (* frame_pointer_required) (void);
1127 /* Returns true if the compiler is allowed to try to replace register number
1128 from-reg with register number to-reg. */
1129 bool (* can_eliminate) (const int, const int);
1131 /* Functions specific to the C family of frontends. */
1133 /* Return machine mode for non-standard suffix
1134 or VOIDmode if non-standard suffixes are unsupported. */
1135 enum machine_mode (*mode_for_suffix) (char);
1138 /* Functions specific to the C++ frontend. */
1140 /* Return the integer type used for guard variables. */
1141 tree (*guard_type) (void);
1142 /* Return true if only the low bit of the guard should be tested. */
1143 bool (*guard_mask_bit) (void);
1144 /* Returns the size of the array cookie for an array of type. */
1145 tree (*get_cookie_size) (tree);
1146 /* Returns true if the element size should be stored in the
1148 bool (*cookie_has_size) (void);
1149 /* Allows backends to perform additional processing when
1150 deciding if a class should be exported or imported. */
1151 int (*import_export_class) (tree, int);
1152 /* Returns true if constructors and destructors return "this". */
1153 bool (*cdtor_returns_this) (void);
1154 /* Returns true if the key method for a class can be an inline
1155 function, so long as it is not declared inline in the class
1156 itself. Returning true is the behavior required by the Itanium
1158 bool (*key_method_may_be_inline) (void);
1159 /* DECL is a virtual table, virtual table table, typeinfo object,
1160 or other similar implicit class data object that will be
1161 emitted with external linkage in this translation unit. No ELF
1162 visibility has been explicitly specified. If the target needs
1163 to specify a visibility other than that of the containing class,
1164 use this hook to set DECL_VISIBILITY and
1165 DECL_VISIBILITY_SPECIFIED. */
1166 void (*determine_class_data_visibility) (tree decl);
1167 /* Returns true (the default) if virtual tables and other
1168 similar implicit class data objects are always COMDAT if they
1169 have external linkage. If this hook returns false, then
1170 class data for classes whose virtual table will be emitted in
1171 only one translation unit will not be COMDAT. */
1172 bool (*class_data_always_comdat) (void);
1173 /* Returns true (the default) if the RTTI for the basic types,
1174 which is always defined in the C++ runtime, should be COMDAT;
1175 false if it should not be COMDAT. */
1176 bool (*library_rtti_comdat) (void);
1177 /* Returns true if __aeabi_atexit should be used to register static
1179 bool (*use_aeabi_atexit) (void);
1180 /* Returns true if target may use atexit in the same manner as
1181 __cxa_atexit to register static destructors. */
1182 bool (*use_atexit_for_cxa_atexit) (void);
1183 /* TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that
1184 has just been defined. Use this hook to make adjustments to the
1185 class (eg, tweak visibility or perform any other required
1186 target modifications). */
1187 void (*adjust_class_at_definition) (tree type);
1190 /* Functions and data for emulated TLS support. */
1192 /* Name of the address and common functions. */
1193 const char *get_address;
1194 const char *register_common;
1196 /* Prefixes for proxy variable and template. */
1197 const char *var_section;
1198 const char *tmpl_section;
1200 /* Prefixes for proxy variable and template. */
1201 const char *var_prefix;
1202 const char *tmpl_prefix;
1204 /* Function to generate field definitions of the proxy variable. */
1205 tree (*var_fields) (tree, tree *);
1207 /* Function to initialize a proxy variable. */
1208 tree (*var_init) (tree, tree, tree);
1210 /* Whether we are allowed to alter the usual alignment of the
1212 bool var_align_fixed;
1214 /* Whether we can emit debug information for TLS vars. */
1215 bool debug_form_tls_address;
1218 struct target_option_hooks {
1219 /* Function to validate the attribute((option(...))) strings or NULL. If
1220 the option is validated, it is assumed that DECL_FUNCTION_SPECIFIC will
1221 be filled in in the function decl node. */
1222 bool (*valid_attribute_p) (tree, tree, tree, int);
1224 /* Function to save any extra target state in the target options
1226 void (*save) (struct cl_target_option *);
1228 /* Function to restore any extra target state from the target options
1230 void (*restore) (struct cl_target_option *);
1232 /* Function to print any extra target state from the target options
1234 void (*print) (FILE *, int, struct cl_target_option *);
1236 /* Function to parse arguments to be validated for #pragma option, and to
1237 change the state if the options are valid. If the first argument is
1238 NULL, the second argument specifies the default options to use. Return
1239 true if the options are valid, and set the current state. */
1240 bool (*pragma_parse) (tree, tree);
1242 /* Function to determine if one function can inline another function. */
1243 bool (*can_inline_p) (tree, tree);
1246 /* For targets that need to mark extra registers as live on entry to
1247 the function, they should define this target hook and set their
1248 bits in the bitmap passed in. */
1249 void (*live_on_entry) (bitmap);
1251 /* True if unwinding tables should be generated by default. */
1252 bool unwind_tables_default;
1254 /* Leave the boolean fields at the end. */
1256 /* True if arbitrary sections are supported. */
1257 bool have_named_sections;
1259 /* True if we can create zeroed data by switching to a BSS section
1260 and then using ASM_OUTPUT_SKIP to allocate the space. */
1261 bool have_switchable_bss_sections;
1263 /* True if "native" constructors and destructors are supported,
1264 false if we're using collect2 for the job. */
1265 bool have_ctors_dtors;
1267 /* True if thread-local storage is supported. */
1270 /* True if a small readonly data section is supported. */
1271 bool have_srodata_section;
1273 /* True if EH frame info sections should be zero-terminated. */
1274 bool terminate_dw2_eh_frame_info;
1276 /* True if #NO_APP should be emitted at the beginning of
1278 bool file_start_app_off;
1280 /* True if output_file_directive should be called for main_input_filename
1281 at the beginning of assembly output. */
1282 bool file_start_file_directive;
1284 /* True if #pragma extern_prefix is to be supported. */
1285 bool handle_pragma_extern_prefix;
1287 /* True if the target is allowed to reorder memory accesses unless
1288 synchronization is explicitly requested. */
1289 bool relaxed_ordering;
1291 /* Returns true if we should generate exception tables for use with the
1292 ARM EABI. The effects the encoding of function exception specifications.
1294 bool arm_eabi_unwinder;
1296 /* Leave the boolean fields at the end. */
1299 extern struct gcc_target targetm;
1301 struct gcc_targetcm {
1302 /* Handle target switch CODE (an OPT_* value). ARG is the argument
1303 passed to the switch; it is NULL if no argument was. VALUE is the
1304 value of ARG if CODE specifies a UInteger option, otherwise it is
1305 1 if the positive form of the switch was used and 0 if the negative
1306 form was. Return true if the switch was valid. */
1307 bool (*handle_c_option) (size_t code, const char *arg, int value);
1310 /* Each target can provide their own. */
1311 extern struct gcc_targetcm targetcm;
1313 #endif /* GCC_TARGET_H */