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[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [gcc/] [target.h] - Blame information for rev 280

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1 280 jeremybenn
/* 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.
4
 
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
8
   later version.
9
 
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.
14
 
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/>.
18
 
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!  */
22
 
23
 
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
27
   information.
28
 
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
31
   macros.
32
 
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
38
   "targetm" like so:
39
 
40
   struct gcc_target targetm = TARGET_INITIALIZER;
41
 
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.  */
48
 
49
#ifndef GCC_TARGET_H
50
#define GCC_TARGET_H
51
 
52
#include "tm.h"
53
#include "insn-modes.h"
54
 
55
/* Types used by the record_gcc_switches() target function.  */
56
typedef enum
57
{
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.  */
63
}
64
print_switch_type;
65
 
66
typedef int (* print_switch_fn_type) (print_switch_type, const char *);
67
 
68
/* An example implementation for ELF targets.  Defined in varasm.c  */
69
extern int elf_record_gcc_switches (print_switch_type type, const char *);
70
 
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);
76
 
77
struct stdarg_info;
78
struct spec_info_def;
79
 
80
/* The struct used by the secondary_reload target hook.  */
81
typedef struct secondary_reload_info
82
{
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 .  */
85
  int icode;
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;
93
 
94
/* This is defined in sched-int.h .  */
95
struct _dep;
96
 
97
/* This is defined in ddg.h .  */
98
struct ddg;
99
 
100
/* Assembler instructions for creating various kinds of integer object.  */
101
 
102
struct asm_int_op
103
{
104
  const char *hi;
105
  const char *si;
106
  const char *di;
107
  const char *ti;
108
};
109
 
110
/* The target structure.  This holds all the backend hooks.  */
111
 
112
struct gcc_target
113
{
114
  /* Functions that output assembler for the target.  */
115
  struct asm_out
116
  {
117
    /* Opening and closing parentheses for asm expression grouping.  */
118
    const char *open_paren, *close_paren;
119
 
120
    /* Assembler instructions for creating various kinds of integer object.  */
121
    const char *byte_op;
122
    struct asm_int_op aligned_op, unaligned_op;
123
 
124
    /* Try to output the assembler code for an integer object whose
125
       value is given by X.  SIZE is the size of the object in bytes and
126
       ALIGNED_P indicates whether it is aligned.  Return true if
127
       successful.  Only handles cases for which BYTE_OP, ALIGNED_OP
128
       and UNALIGNED_OP are NULL.  */
129
    bool (* integer) (rtx x, unsigned int size, int aligned_p);
130
 
131
    /* Output code that will globalize a label.  */
132
    void (* globalize_label) (FILE *, const char *);
133
 
134
    /* Output code that will globalize a declaration.  */
135
    void (* globalize_decl_name) (FILE *, tree);
136
 
137
    /* Output code that will emit a label for unwind info, if this
138
       target requires such labels.  Second argument is the decl the
139
       unwind info is associated with, third is a boolean: true if
140
       this is for exception handling, fourth is a boolean: true if
141
       this is only a placeholder for an omitted FDE.  */
142
    void (* unwind_label) (FILE *, tree, int, int);
143
 
144
    /* Output code that will emit a label to divide up the exception
145
       table.  */
146
    void (* except_table_label) (FILE *);
147
 
148
    /* Emit any directives required to unwind this instruction.  */
149
    void (* unwind_emit) (FILE *, rtx);
150
 
151
    /* Output an internal label.  */
152
    void (* internal_label) (FILE *, const char *, unsigned long);
153
 
154
    /* Emit a ttype table reference to a typeinfo object.  */
155
    bool (* ttype) (rtx);
156
 
157
    /* Emit an assembler directive to set visibility for the symbol
158
       associated with the tree decl.  */
159
    void (* visibility) (tree, int);
160
 
161
    /* Output the assembler code for entry to a function.  */
162
    void (* function_prologue) (FILE *, HOST_WIDE_INT);
163
 
164
    /* Output the assembler code for end of prologue.  */
165
    void (* function_end_prologue) (FILE *);
166
 
167
    /* Output the assembler code for start of epilogue.  */
168
    void (* function_begin_epilogue) (FILE *);
169
 
170
    /* Output the assembler code for function exit.  */
171
    void (* function_epilogue) (FILE *, HOST_WIDE_INT);
172
 
173
    /* Initialize target-specific sections.  */
174
    void (* init_sections) (void);
175
 
176
    /* Tell assembler to change to section NAME with attributes FLAGS.
177
       If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
178
       which this section is associated.  */
179
    void (* named_section) (const char *name, unsigned int flags, tree decl);
180
 
181
    /* Return a mask describing how relocations should be treated when
182
       selecting sections.  Bit 1 should be set if global relocations
183
       should be placed in a read-write section; bit 0 should be set if
184
       local relocations should be placed in a read-write section.  */
185
    int (*reloc_rw_mask) (void);
186
 
187
    /* Return a section for EXP.  It may be a DECL or a constant.  RELOC
188
       is nonzero if runtime relocations must be applied; bit 1 will be
189
       set if the runtime relocations require non-local name resolution.
190
       ALIGN is the required alignment of the data.  */
191
    section *(* select_section) (tree, int, unsigned HOST_WIDE_INT);
192
 
193
    /* Return a section for X.  MODE is X's mode and ALIGN is its
194
       alignment in bits.  */
195
    section *(* select_rtx_section) (enum machine_mode, rtx,
196
                                     unsigned HOST_WIDE_INT);
197
 
198
    /* Select a unique section name for DECL.  RELOC is the same as
199
       for SELECT_SECTION.  */
200
    void (* unique_section) (tree, int);
201
 
202
    /* Return the readonly data section associated with function DECL.  */
203
    section *(* function_rodata_section) (tree);
204
 
205
    /* Output a constructor for a symbol with a given priority.  */
206
    void (* constructor) (rtx, int);
207
 
208
    /* Output a destructor for a symbol with a given priority.  */
209
    void (* destructor) (rtx, int);
210
 
211
    /* Output the assembler code for a thunk function.  THUNK_DECL is the
212
       declaration for the thunk function itself, FUNCTION is the decl for
213
       the target function.  DELTA is an immediate constant offset to be
214
       added to THIS.  If VCALL_OFFSET is nonzero, the word at
215
       *(*this + vcall_offset) should be added to THIS.  */
216
    void (* output_mi_thunk) (FILE *file, tree thunk_decl,
217
                              HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
218
                              tree function_decl);
219
 
220
    /* Determine whether output_mi_thunk would succeed.  */
221
    /* ??? Ideally, this hook would not exist, and success or failure
222
       would be returned from output_mi_thunk directly.  But there's
223
       too much undo-able setup involved in invoking output_mi_thunk.
224
       Could be fixed by making output_mi_thunk emit rtl instead of
225
       text to the output file.  */
226
    bool (* can_output_mi_thunk) (const_tree thunk_decl, HOST_WIDE_INT delta,
227
                                  HOST_WIDE_INT vcall_offset,
228
                                  const_tree function_decl);
229
 
230
    /* Output any boilerplate text needed at the beginning of a
231
       translation unit.  */
232
    void (*file_start) (void);
233
 
234
    /* Output any boilerplate text needed at the end of a
235
       translation unit.  */
236
    void (*file_end) (void);
237
 
238
    /* Output any boilerplate text needed at the beginning of an
239
       LTO output stream.  */
240
    void (*lto_start) (void);
241
 
242
    /* Output any boilerplate text needed at the end of an
243
       LTO output stream.  */
244
    void (*lto_end) (void);
245
 
246
    /* Output any boilerplace text needed at the end of a
247
       translation unit before debug and unwind info is emitted.  */
248
    void (*code_end) (void);
249
 
250
    /* Output an assembler pseudo-op to declare a library function name
251
       external.  */
252
    void (*external_libcall) (rtx);
253
 
254
    /* Output an assembler directive to mark decl live. This instructs
255
        linker to not dead code strip this symbol.  */
256
    void (*mark_decl_preserved) (const char *);
257
 
258
    /* Output a record of the command line switches that have been passed.  */
259
    print_switch_fn_type record_gcc_switches;
260
    /* The name of the section that the example ELF implementation of
261
       record_gcc_switches will use to store the information.  Target
262
       specific versions of record_gcc_switches may or may not use
263
       this information.  */
264
    const char * record_gcc_switches_section;
265
 
266
    /* Output the definition of a section anchor.  */
267
    void (*output_anchor) (rtx);
268
 
269
    /* Output a DTP-relative reference to a TLS symbol.  */
270
    void (*output_dwarf_dtprel) (FILE *file, int size, rtx x);
271
 
272
    /* Some target machines need to postscan each insn after it is output.  */
273
    void (*final_postscan_insn) (FILE *, rtx, rtx *, int);
274
 
275
    /* Emit the trampoline template.  This hook may be NULL.  */
276
    void (*trampoline_template) (FILE *);
277
  } asm_out;
278
 
279
  /* Functions relating to instruction scheduling.  */
280
  struct sched
281
  {
282
    /* Given the current cost, COST, of an insn, INSN, calculate and
283
       return a new cost based on its relationship to DEP_INSN through
284
       the dependence LINK.  The default is to make no adjustment.  */
285
    int (* adjust_cost) (rtx insn, rtx link, rtx dep_insn, int cost);
286
 
287
    /* Adjust the priority of an insn as you see fit.  Returns the new
288
       priority.  */
289
    int (* adjust_priority) (rtx, int);
290
 
291
    /* Function which returns the maximum number of insns that can be
292
       scheduled in the same machine cycle.  This must be constant
293
       over an entire compilation.  The default is 1.  */
294
    int (* issue_rate) (void);
295
 
296
    /* Calculate how much this insn affects how many more insns we
297
       can emit this cycle.  Default is they all cost the same.  */
298
    int (* variable_issue) (FILE *, int, rtx, int);
299
 
300
    /* Initialize machine-dependent scheduling code.  */
301
    void (* md_init) (FILE *, int, int);
302
 
303
    /* Finalize machine-dependent scheduling code.  */
304
    void (* md_finish) (FILE *, int);
305
 
306
    /* Initialize machine-dependent function wide scheduling code.  */
307
    void (* md_init_global) (FILE *, int, int);
308
 
309
    /* Finalize machine-dependent function wide scheduling code.  */
310
    void (* md_finish_global) (FILE *, int);
311
 
312
    /* Reorder insns in a machine-dependent fashion, in two different
313
       places.  Default does nothing.  */
314
    int (* reorder) (FILE *, int, rtx *, int *, int);
315
    int (* reorder2) (FILE *, int, rtx *, int *, int);
316
 
317
    /* The following member value is a pointer to a function called
318
       after evaluation forward dependencies of insns in chain given
319
       by two parameter values (head and tail correspondingly).  */
320
    void (* dependencies_evaluation_hook) (rtx, rtx);
321
 
322
    /* The values of the following four members are pointers to
323
       functions used to simplify the automaton descriptions.
324
       dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
325
       returning insns which are used to change the pipeline hazard
326
       recognizer state when the new simulated processor cycle
327
       correspondingly starts and finishes.  The function defined by
328
       init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
329
       to initialize the corresponding insns.  The default values of
330
       the members result in not changing the automaton state when
331
       the new simulated processor cycle correspondingly starts and
332
       finishes.  */
333
    void (* init_dfa_pre_cycle_insn) (void);
334
    rtx (* dfa_pre_cycle_insn) (void);
335
    void (* init_dfa_post_cycle_insn) (void);
336
    rtx (* dfa_post_cycle_insn) (void);
337
 
338
    /* The values of the following two members are pointers to
339
       functions used to simplify the automaton descriptions.
340
       dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called
341
       immediately before and after cycle is advanced.  */
342
    void (* dfa_pre_advance_cycle) (void);
343
    void (* dfa_post_advance_cycle) (void);
344
 
345
    /* The following member value is a pointer to a function returning value
346
       which defines how many insns in queue `ready' will we try for
347
       multi-pass scheduling.  If the member value is nonzero and the
348
       function returns positive value, the DFA based scheduler will make
349
       multi-pass scheduling for the first cycle.  In other words, we will
350
       try to choose ready insn which permits to start maximum number of
351
       insns on the same cycle.  */
352
    int (* first_cycle_multipass_dfa_lookahead) (void);
353
 
354
    /* The following member value is pointer to a function controlling
355
       what insns from the ready insn queue will be considered for the
356
       multipass insn scheduling.  If the hook returns zero for insn
357
       passed as the parameter, the insn will be not chosen to be
358
       issued.  */
359
    int (* first_cycle_multipass_dfa_lookahead_guard) (rtx);
360
 
361
    /* The following member value is pointer to a function called by
362
       the insn scheduler before issuing insn passed as the third
363
       parameter on given cycle.  If the hook returns nonzero, the
364
       insn is not issued on given processors cycle.  Instead of that,
365
       the processor cycle is advanced.  If the value passed through
366
       the last parameter is zero, the insn ready queue is not sorted
367
       on the new cycle start as usually.  The first parameter passes
368
       file for debugging output.  The second one passes the scheduler
369
       verbose level of the debugging output.  The forth and the fifth
370
       parameter values are correspondingly processor cycle on which
371
       the previous insn has been issued and the current processor
372
       cycle.  */
373
    int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *);
374
 
375
    /* The following member value is a pointer to a function called by the
376
       insn scheduler.  It should return true if there exists a dependence
377
       which is considered costly by the target, between the insn
378
       DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP).  The first parameter is
379
       the dep that represents the dependence between the two insns.  The
380
       second argument is the cost of the dependence as estimated by
381
       the scheduler.  The last argument is the distance in cycles
382
       between the already scheduled insn (first parameter) and the
383
       second insn (second parameter).  */
384
    bool (* is_costly_dependence) (struct _dep *_dep, int, int);
385
 
386
    /* Given the current cost, COST, of an insn, INSN, calculate and
387
       return a new cost based on its relationship to DEP_INSN through the
388
       dependence of type DEP_TYPE.  The default is to make no adjustment.  */
389
    int (* adjust_cost_2) (rtx insn, int, rtx dep_insn, int cost, int dw);
390
 
391
    /* The following member value is a pointer to a function called
392
       by the insn scheduler. This hook is called to notify the backend
393
       that new instructions were emitted.  */
394
    void (* h_i_d_extended) (void);
395
 
396
    /* Next 5 functions are for multi-point scheduling.  */
397
 
398
    /* Allocate memory for scheduler context.  */
399
    void *(* alloc_sched_context) (void);
400
 
401
    /* Fills the context from the local machine scheduler context.  */
402
    void (* init_sched_context) (void *, bool);
403
 
404
    /* Sets local machine scheduler context to a saved value.  */
405
    void (* set_sched_context) (void *);
406
 
407
    /* Clears a scheduler context so it becomes like after init.  */
408
    void (* clear_sched_context) (void *);
409
 
410
    /* Frees the scheduler context.  */
411
    void (* free_sched_context) (void *);
412
 
413
    /* The following member value is a pointer to a function called
414
       by the insn scheduler.
415
       The first parameter is an instruction, the second parameter is the type
416
       of the requested speculation, and the third parameter is a pointer to the
417
       speculative pattern of the corresponding type (set if return value == 1).
418
       It should return
419
       -1, if there is no pattern, that will satisfy the requested speculation
420
       type,
421
       0, if current pattern satisfies the requested speculation type,
422
       1, if pattern of the instruction should be changed to the newly
423
       generated one.  */
424
    int (* speculate_insn) (rtx, int, rtx *);
425
 
426
    /* The following member value is a pointer to a function called
427
       by the insn scheduler.  It should return true if the check instruction
428
       passed as the parameter needs a recovery block.  */
429
    bool (* needs_block_p) (int);
430
 
431
    /* The following member value is a pointer to a function called
432
       by the insn scheduler.  It should return a pattern for the check
433
       instruction.
434
       The first parameter is a speculative instruction, the second parameter
435
       is the label of the corresponding recovery block (or null, if it is a
436
       simple check).  If the mutation of the check is requested (e.g. from
437
       ld.c to chk.a), the third parameter is true - in this case the first
438
       parameter is the previous check.  */
439
    rtx (* gen_spec_check) (rtx, rtx, int);
440
 
441
    /* The following member value is a pointer to a function controlling
442
       what insns from the ready insn queue will be considered for the
443
       multipass insn scheduling.  If the hook returns zero for the insn
444
       passed as the parameter, the insn will not be chosen to be
445
       issued.  This hook is used to discard speculative instructions,
446
       that stand at the first position of the ready list.  */
447
    bool (* first_cycle_multipass_dfa_lookahead_guard_spec) (const_rtx);
448
 
449
    /* The following member value is a pointer to a function that provides
450
       information about the speculation capabilities of the target.
451
       The parameter is a pointer to spec_info variable.  */
452
    void (* set_sched_flags) (struct spec_info_def *);
453
 
454
    /* Return speculation types of the instruction passed as the parameter.  */
455
    int (* get_insn_spec_ds) (rtx);
456
 
457
    /* Return speculation types that are checked for the instruction passed as
458
       the parameter.  */
459
    int (* get_insn_checked_ds) (rtx);
460
 
461
    /* Return bool if rtx scanning should just skip current layer and
462
       advance to the inner rtxes.  */
463
    bool (* skip_rtx_p) (const_rtx);
464
 
465
    /* The following member value is a pointer to a function that provides
466
       information about the target resource-based lower bound which is
467
       used by the swing modulo scheduler.  The parameter is a pointer
468
       to ddg variable.  */
469
    int (* sms_res_mii) (struct ddg *);
470
  } sched;
471
 
472
  /* Functions relating to vectorization.  */
473
  struct vectorize
474
  {
475
    /* The following member value is a pointer to a function called
476
       by the vectorizer, and return the decl of the target builtin
477
       function.  */
478
    tree (* builtin_mask_for_load) (void);
479
 
480
    /* Returns a code for builtin that realizes vectorized version of
481
       function, or NULL_TREE if not available.  */
482
    tree (* builtin_vectorized_function) (tree, tree, tree);
483
 
484
    /* Returns a code for builtin that realizes vectorized version of
485
       conversion, or NULL_TREE if not available.  */
486
    tree (* builtin_conversion) (unsigned, tree);
487
 
488
    /* Target builtin that implements vector widening multiplication.
489
       builtin_mul_widen_eve computes the element-by-element products
490
       for the even elements, and builtin_mul_widen_odd computes the
491
       element-by-element products for the odd elements.  */
492
    tree (* builtin_mul_widen_even) (tree);
493
    tree (* builtin_mul_widen_odd) (tree);
494
 
495
    /* Returns the cost to be added to the overheads involved with
496
       executing the vectorized version of a loop.  */
497
    int (*builtin_vectorization_cost) (bool);
498
 
499
    /* Return true if vector alignment is reachable (by peeling N
500
       iterations) for the given type.  */
501
    bool (* vector_alignment_reachable) (const_tree, bool);
502
 
503
    /* Target builtin that implements vector permute.  */
504
    tree (* builtin_vec_perm) (tree, tree*);
505
 
506
    /* Return true if a vector created for builtin_vec_perm is valid.  */
507
    bool (* builtin_vec_perm_ok) (tree, tree);
508
 
509
    /* Return true if the target supports misaligned store/load of a
510
       specific factor denoted in the third parameter.  The last parameter
511
       is true if the access is defined in a packed struct.  */
512
    bool (* builtin_support_vector_misalignment) (enum machine_mode,
513
                                                  const_tree, int, bool);
514
  } vectorize;
515
 
516
  /* The initial value of target_flags.  */
517
  int default_target_flags;
518
 
519
  /* Allow target specific overriding of option settings after options have
520
     been changed by an attribute or pragma or when it is reset at the
521
     end of the code affected by an attribute or pragma.  */
522
  void (* override_options_after_change) (void);
523
 
524
  /* Handle target switch CODE (an OPT_* value).  ARG is the argument
525
     passed to the switch; it is NULL if no argument was.  VALUE is the
526
     value of ARG if CODE specifies a UInteger option, otherwise it is
527
     1 if the positive form of the switch was used and 0 if the negative
528
     form was.  Return true if the switch was valid.  */
529
  bool (* handle_option) (size_t code, const char *arg, int value);
530
 
531
  /* Display extra, target specific information in response to a
532
     --target-help switch.  */
533
  void (* target_help) (void);
534
 
535
  /* Return machine mode for filter value.  */
536
  enum machine_mode (* eh_return_filter_mode) (void);
537
 
538
  /* Return machine mode for libgcc expanded cmp instructions.  */
539
  enum machine_mode (* libgcc_cmp_return_mode) (void);
540
 
541
  /* Return machine mode for libgcc expanded shift instructions.  */
542
  enum machine_mode (* libgcc_shift_count_mode) (void);
543
 
544
  /* Return machine mode to be used for _Unwind_Word type.  */
545
  enum machine_mode (* unwind_word_mode) (void);
546
 
547
  /* Given two decls, merge their attributes and return the result.  */
548
  tree (* merge_decl_attributes) (tree, tree);
549
 
550
  /* Given two types, merge their attributes and return the result.  */
551
  tree (* merge_type_attributes) (tree, tree);
552
 
553
  /* Table of machine attributes and functions to handle them.
554
     Ignored if NULL.  */
555
  const struct attribute_spec *attribute_table;
556
 
557
  /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
558
     one if they are compatible and two if they are nearly compatible
559
     (which causes a warning to be generated).  */
560
  int (* comp_type_attributes) (const_tree type1, const_tree type2);
561
 
562
  /* Assign default attributes to the newly defined TYPE.  */
563
  void (* set_default_type_attributes) (tree type);
564
 
565
  /* Insert attributes on the newly created DECL.  */
566
  void (* insert_attributes) (tree decl, tree *attributes);
567
 
568
  /* Return true if FNDECL (which has at least one machine attribute)
569
     can be inlined despite its machine attributes, false otherwise.  */
570
  bool (* function_attribute_inlinable_p) (const_tree fndecl);
571
 
572
  /* Return true if bitfields in RECORD_TYPE should follow the
573
     Microsoft Visual C++ bitfield layout rules.  */
574
  bool (* ms_bitfield_layout_p) (const_tree record_type);
575
 
576
  /* True if the target supports decimal floating point.  */
577
  bool (* decimal_float_supported_p) (void);
578
 
579
  /* True if the target supports fixed-point.  */
580
  bool (* fixed_point_supported_p) (void);
581
 
582
  /* Return true if anonymous bitfields affect structure alignment.  */
583
  bool (* align_anon_bitfield) (void);
584
 
585
  /* Return true if volatile bitfields should use the narrowest type possible.
586
     Return false if they should use the container type.  */
587
  bool (* narrow_volatile_bitfield) (void);
588
 
589
  /* Set up target-specific built-in functions.  */
590
  void (* init_builtins) (void);
591
 
592
  /* Initialize (if INITIALIZE_P is true) and return the target-specific
593
     built-in function decl for CODE.
594
     Return NULL if that is not possible.  Return error_mark_node if CODE
595
     is outside of the range of valid target builtin function codes.  */
596
  tree (* builtin_decl) (unsigned code, bool initialize_p);
597
 
598
  /* Expand a target-specific builtin.  */
599
  rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget,
600
                          enum machine_mode mode, int ignore);
601
 
602
  /* Select a replacement for a target-specific builtin.  This is done
603
     *before* regular type checking, and so allows the target to
604
     implement a crude form of function overloading.  The result is a
605
     complete expression that implements the operation.  PARAMS really
606
     has type VEC(tree,gc)*, but we don't want to include tree.h
607
     here.  */
608
  tree (*resolve_overloaded_builtin) (unsigned int /*location_t*/,
609
                                      tree decl, void *params);
610
 
611
  /* Fold a target-specific builtin.  */
612
  tree (* fold_builtin) (tree fndecl, tree arglist, bool ignore);
613
 
614
  /* Returns a code for a target-specific builtin that implements
615
     reciprocal of the function, or NULL_TREE if not available.  */
616
  tree (* builtin_reciprocal) (unsigned, bool, bool);
617
 
618
  /* For a vendor-specific TYPE, return a pointer to a statically-allocated
619
     string containing the C++ mangling for TYPE.  In all other cases, return
620
     NULL.  */
621
  const char * (* mangle_type) (const_tree type);
622
 
623
  /* Make any adjustments to libfunc names needed for this target.  */
624
  void (* init_libfuncs) (void);
625
 
626
  /* Given a decl, a section name, and whether the decl initializer
627
     has relocs, choose attributes for the section.  */
628
  /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION.  */
629
  unsigned int (* section_type_flags) (tree, const char *, int);
630
 
631
  /* True if new jumps cannot be created, to replace existing ones or
632
     not, at the current point in the compilation.  */
633
  bool (* cannot_modify_jumps_p) (void);
634
 
635
  /* Return a register class for which branch target register
636
     optimizations should be applied.  */
637
  enum reg_class (* branch_target_register_class) (void);
638
 
639
  /* Return true if branch target register optimizations should include
640
     callee-saved registers that are not already live during the current
641
     function.  AFTER_PE_GEN is true if prologues and epilogues have
642
     already been generated.  */
643
  bool (* branch_target_register_callee_saved) (bool after_pe_gen);
644
 
645
  /* Return true if the target supports conditional execution.  */
646
  bool (* have_conditional_execution) (void);
647
 
648
  /* True if the constant X cannot be placed in the constant pool.  */
649
  bool (* cannot_force_const_mem) (rtx);
650
 
651
  /* True if the insn X cannot be duplicated.  */
652
  bool (* cannot_copy_insn_p) (rtx);
653
 
654
  /* True if X is considered to be commutative.  */
655
  bool (* commutative_p) (const_rtx, int);
656
 
657
  /* Given an invalid address X for a given machine mode, try machine-specific
658
     ways to make it legitimate.  Return X or an invalid address on failure.  */
659
  rtx (* legitimize_address) (rtx, rtx, enum machine_mode);
660
 
661
  /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS.  */
662
  rtx (* delegitimize_address) (rtx);
663
 
664
  /* Given an address RTX, say whether it is valid.  */
665
  bool (* legitimate_address_p) (enum machine_mode, rtx, bool);
666
 
667
  /* True if the given constant can be put into an object_block.  */
668
  bool (* use_blocks_for_constant_p) (enum machine_mode, const_rtx);
669
 
670
  /* The minimum and maximum byte offsets for anchored addresses.  */
671
  HOST_WIDE_INT min_anchor_offset;
672
  HOST_WIDE_INT max_anchor_offset;
673
 
674
  /* True if section anchors can be used to access the given symbol.  */
675
  bool (* use_anchors_for_symbol_p) (const_rtx);
676
 
677
  /* True if it is OK to do sibling call optimization for the specified
678
     call expression EXP.  DECL will be the called function, or NULL if
679
     this is an indirect call.  */
680
  bool (*function_ok_for_sibcall) (tree decl, tree exp);
681
 
682
  /* Establish appropriate back-end context for processing the function
683
     FNDECL.  The argument might be NULL to indicate processing at top
684
     level, outside of any function scope.  */
685
  void (*set_current_function) (tree fndecl);
686
 
687
  /* True if EXP should be placed in a "small data" section.  */
688
  bool (* in_small_data_p) (const_tree);
689
 
690
  /* True if EXP names an object for which name resolution must resolve
691
     to the current executable or shared library.  */
692
  bool (* binds_local_p) (const_tree);
693
 
694
  /* Modify and return the identifier of a DECL's external name,
695
     originally identified by ID, as required by the target,
696
    (eg, append @nn to windows32 stdcall function names).
697
     The default is to return ID without modification. */
698
   tree (* mangle_decl_assembler_name) (tree decl, tree  id);
699
 
700
  /* Do something target-specific to record properties of the DECL into
701
     the associated SYMBOL_REF.  */
702
  void (* encode_section_info) (tree, rtx, int);
703
 
704
  /* Undo the effects of encode_section_info on the symbol string.  */
705
  const char * (* strip_name_encoding) (const char *);
706
 
707
  /* If shift optabs for MODE are known to always truncate the shift count,
708
     return the mask that they apply.  Return 0 otherwise.  */
709
  unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode);
710
 
711
  /* Return the number of divisions in the given MODE that should be present,
712
     so that it is profitable to turn the division into a multiplication by
713
     the reciprocal.  */
714
  unsigned int (* min_divisions_for_recip_mul) (enum machine_mode mode);
715
 
716
  /* If the representation of integral MODE is such that values are
717
     always sign-extended to a wider mode MODE_REP then return
718
     SIGN_EXTEND.  Return UNKNOWN otherwise.  */
719
  /* Note that the return type ought to be RTX_CODE, but that's not
720
     necessarily defined at this point.  */
721
  int (* mode_rep_extended) (enum machine_mode mode,
722
                             enum machine_mode mode_rep);
723
 
724
  /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))).  */
725
  bool (* valid_pointer_mode) (enum machine_mode mode);
726
 
727
  /* Support for named address spaces.  */
728
  struct addr_space {
729
    /* MODE to use for a pointer into another address space.  */
730
    enum machine_mode (* pointer_mode) (addr_space_t);
731
 
732
    /* MODE to use for an address in another address space.  */
733
    enum machine_mode (* address_mode) (addr_space_t);
734
 
735
    /* True if MODE is valid for a pointer in __attribute__((mode("MODE")))
736
       in another address space.  */
737
    bool (* valid_pointer_mode) (enum machine_mode, addr_space_t);
738
 
739
    /* True if an address is a valid memory address to a given named address
740
       space for a given mode.  */
741
    bool (* legitimate_address_p) (enum machine_mode, rtx, bool, addr_space_t);
742
 
743
    /* Return an updated address to convert an invalid pointer to a named
744
       address space to a valid one.  If NULL_RTX is returned use machine
745
       independent methods to make the address valid.  */
746
    rtx (* legitimize_address) (rtx, rtx, enum machine_mode, addr_space_t);
747
 
748
    /* True if one named address space is a subset of another named address. */
749
    bool (* subset_p) (addr_space_t, addr_space_t);
750
 
751
    /* Function to convert an rtl expression from one address space to
752
       another.  */
753
    rtx (* convert) (rtx, tree, tree);
754
 
755
  } addr_space;
756
 
757
  /* True if MODE is valid for the target.  By "valid", we mean able to
758
     be manipulated in non-trivial ways.  In particular, this means all
759
     the arithmetic is supported.  */
760
  bool (* scalar_mode_supported_p) (enum machine_mode mode);
761
 
762
  /* Similarly for vector modes.  "Supported" here is less strict.  At
763
     least some operations are supported; need to check optabs or builtins
764
     for further details.  */
765
  bool (* vector_mode_supported_p) (enum machine_mode mode);
766
 
767
  /* Compute a (partial) cost for rtx X.  Return true if the complete
768
     cost has been computed, and false if subexpressions should be
769
     scanned.  In either case, *TOTAL contains the cost result.  */
770
  /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
771
     not necessarily defined at this point.  */
772
  bool (* rtx_costs) (rtx x, int code, int outer_code, int *total, bool speed);
773
 
774
  /* Compute the cost of X, used as an address.  Never called with
775
     invalid addresses.  */
776
  int (* address_cost) (rtx x, bool speed);
777
 
778
  /* Return where to allocate pseudo for a given hard register initial
779
     value.  */
780
  rtx (* allocate_initial_value) (rtx x);
781
 
782
  /* Return nonzero if evaluating UNSPEC[_VOLATILE] X might cause a trap.
783
     FLAGS has the same meaning as in rtlanal.c: may_trap_p_1.  */
784
  int (* unspec_may_trap_p) (const_rtx x, unsigned flags);
785
 
786
  /* Given a register, this hook should return a parallel of registers
787
     to represent where to find the register pieces.  Define this hook
788
     if the register and its mode are represented in Dwarf in
789
     non-contiguous locations, or if the register should be
790
     represented in more than one register in Dwarf.  Otherwise, this
791
     hook should return NULL_RTX.  */
792
  rtx (* dwarf_register_span) (rtx);
793
 
794
  /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
795
     entries not corresponding directly to registers below
796
     FIRST_PSEUDO_REGISTER, this hook should generate the necessary
797
     code, given the address of the table.  */
798
  void (* init_dwarf_reg_sizes_extra) (tree);
799
 
800
  /* Fetch the fixed register(s) which hold condition codes, for
801
     targets where it makes sense to look for duplicate assignments to
802
     the condition codes.  This should return true if there is such a
803
     register, false otherwise.  The arguments should be set to the
804
     fixed register numbers.  Up to two condition code registers are
805
     supported.  If there is only one for this target, the int pointed
806
     at by the second argument should be set to -1.  */
807
  bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *);
808
 
809
  /* If two condition code modes are compatible, return a condition
810
     code mode which is compatible with both, such that a comparison
811
     done in the returned mode will work for both of the original
812
     modes.  If the condition code modes are not compatible, return
813
     VOIDmode.  */
814
  enum machine_mode (* cc_modes_compatible) (enum machine_mode,
815
                                             enum machine_mode);
816
 
817
  /* Do machine-dependent code transformations.  Called just before
818
     delayed-branch scheduling.  */
819
  void (* machine_dependent_reorg) (void);
820
 
821
  /* Create the __builtin_va_list type.  */
822
  tree (* build_builtin_va_list) (void);
823
 
824
  /* Get the cfun/fndecl calling abi __builtin_va_list type.  */
825
  tree (* fn_abi_va_list) (tree);
826
 
827
  /* Get the __builtin_va_list type dependent on input type.  */
828
  tree (* canonical_va_list_type) (tree);
829
 
830
  /* Expand the __builtin_va_start builtin.  */
831
  void (* expand_builtin_va_start) (tree valist, rtx nextarg);
832
 
833
  /* Gimplifies a VA_ARG_EXPR.  */
834
  tree (* gimplify_va_arg_expr) (tree valist, tree type, gimple_seq *pre_p,
835
                                 gimple_seq *post_p);
836
 
837
  /* Validity-checking routines for PCH files, target-specific.
838
     get_pch_validity returns a pointer to the data to be stored,
839
     and stores the size in its argument.  pch_valid_p gets the same
840
     information back and returns NULL if the PCH is valid,
841
     or an error message if not.
842
  */
843
  void * (* get_pch_validity) (size_t *);
844
  const char * (* pch_valid_p) (const void *, size_t);
845
 
846
  /* If nonnull, this function checks whether a PCH file with the
847
     given set of target flags can be used.  It returns NULL if so,
848
     otherwise it returns an error message.  */
849
  const char *(*check_pch_target_flags) (int);
850
 
851
  /* True if the compiler should give an enum type only as many
852
     bytes as it takes to represent the range of possible values of
853
     that type.  */
854
  bool (* default_short_enums) (void);
855
 
856
  /* This target hook returns an rtx that is used to store the address
857
     of the current frame into the built-in setjmp buffer.  */
858
  rtx (* builtin_setjmp_frame_value) (void);
859
 
860
  /* This target hook should add STRING_CST trees for any hard regs
861
     the port wishes to automatically clobber for an asm.  */
862
  tree (* md_asm_clobbers) (tree, tree, tree);
863
 
864
  /* This target hook allows the backend to specify a calling convention
865
     in the debug information.  This function actually returns an
866
     enum dwarf_calling_convention, but because of forward declarations
867
     and not wanting to include dwarf2.h everywhere target.h is included
868
     the function is being declared as an int.  */
869
  int (* dwarf_calling_convention) (const_tree);
870
 
871
  /* This target hook allows the backend to emit frame-related insns that
872
     contain UNSPECs or UNSPEC_VOLATILEs.  The call frame debugging info
873
     engine will invoke it on insns of the form
874
       (set (reg) (unspec [...] UNSPEC_INDEX))
875
     and
876
       (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
877
     to let the backend emit the call frame instructions.  */
878
  void (* dwarf_handle_frame_unspec) (const char *, rtx, int);
879
 
880
  /* Perform architecture specific checking of statements gimplified
881
     from VA_ARG_EXPR.  STMT is the statement.  Returns true if the statement
882
     doesn't need to be checked for va_list references.  */
883
  bool (* stdarg_optimize_hook) (struct stdarg_info *ai, const_gimple stmt);
884
 
885
  /* This target hook allows the operating system to override the DECL
886
     that represents the external variable that contains the stack
887
     protection guard variable.  The type of this DECL is ptr_type_node.  */
888
  tree (* stack_protect_guard) (void);
889
 
890
  /* This target hook allows the operating system to override the CALL_EXPR
891
     that is invoked when a check vs the guard variable fails.  */
892
  tree (* stack_protect_fail) (void);
893
 
894
  /* Returns NULL if target supports the insn within a doloop block,
895
     otherwise it returns an error message.  */
896
  const char * (*invalid_within_doloop) (const_rtx);
897
 
898
  /* DECL is a variable or function with __attribute__((dllimport))
899
     specified.  Use this hook if the target needs to add extra validation
900
     checks to  handle_dll_attribute ().  */
901
  bool (* valid_dllimport_attribute_p) (const_tree decl);
902
 
903
  /* If non-zero, align constant anchors in CSE to a multiple of this
904
     value.  */
905
  unsigned HOST_WIDE_INT const_anchor;
906
 
907
  /* Functions relating to calls - argument passing, returns, etc.  */
908
  struct calls {
909
    enum machine_mode (*promote_function_mode) (const_tree type,
910
                                                enum machine_mode mode,
911
                                                int *punsignedp,
912
                                                const_tree fntype,
913
                                                int for_return);
914
    bool (*promote_prototypes) (const_tree fntype);
915
    rtx (*struct_value_rtx) (tree fndecl, int incoming);
916
    bool (*return_in_memory) (const_tree type, const_tree fndecl);
917
    bool (*return_in_msb) (const_tree type);
918
 
919
    /* Return true if a parameter must be passed by reference.  TYPE may
920
       be null if this is a libcall.  CA may be null if this query is
921
       from __builtin_va_arg.  */
922
    bool (*pass_by_reference) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
923
                               const_tree type, bool named_arg);
924
 
925
    rtx (*expand_builtin_saveregs) (void);
926
    /* Returns pretend_argument_size.  */
927
    void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
928
                                    tree type, int *pretend_arg_size,
929
                                    int second_time);
930
    bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca);
931
    /* Returns true if we should use
932
       targetm.calls.setup_incoming_varargs() and/or
933
       targetm.calls.strict_argument_naming().  */
934
    bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca);
935
 
936
    /* Given a complex type T, return true if a parameter of type T
937
       should be passed as two scalars.  */
938
    bool (* split_complex_arg) (const_tree type);
939
 
940
    /* Return true if type T, mode MODE, may not be passed in registers,
941
       but must be passed on the stack.  */
942
    /* ??? This predicate should be applied strictly after pass-by-reference.
943
       Need audit to verify that this is the case.  */
944
    bool (* must_pass_in_stack) (enum machine_mode mode, const_tree t);
945
 
946
    /* Return true if type TYPE, mode MODE, which is passed by reference,
947
       should have the object copy generated by the callee rather than
948
       the caller.  It is never called for TYPE requiring constructors.  */
949
    bool (* callee_copies) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
950
                            const_tree type, bool named);
951
 
952
    /* Return zero for arguments passed entirely on the stack or entirely
953
       in registers.  If passed in both, return the number of bytes passed
954
       in registers; the balance is therefore passed on the stack.  */
955
    int (* arg_partial_bytes) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
956
                               tree type, bool named);
957
 
958
    /* Return the diagnostic message string if function without a prototype
959
       is not allowed for this 'val' argument; NULL otherwise. */
960
    const char *(*invalid_arg_for_unprototyped_fn) (const_tree typelist,
961
                                                    const_tree funcdecl,
962
                                                    const_tree val);
963
 
964
    /* Return an rtx for the return value location of the function
965
       specified by FN_DECL_OR_TYPE with a return type of RET_TYPE.  */
966
    rtx (*function_value) (const_tree ret_type, const_tree fn_decl_or_type,
967
                           bool outgoing);
968
 
969
    /* Return the rtx for the result of a libcall of mode MODE,
970
       calling the function FN_NAME.  */
971
    rtx (*libcall_value) (enum machine_mode, const_rtx);
972
 
973
    /* Return an rtx for the argument pointer incoming to the
974
       current function.  */
975
    rtx (*internal_arg_pointer) (void);
976
 
977
    /* Update the current function stack boundary if needed.  */
978
    void (*update_stack_boundary) (void);
979
 
980
    /* Handle stack alignment and return an rtx for Dynamic Realign
981
       Argument Pointer if necessary.  */
982
    rtx (*get_drap_rtx) (void);
983
 
984
    /* Return true if all function parameters should be spilled to the
985
       stack.  */
986
    bool (*allocate_stack_slots_for_args) (void);
987
 
988
    /* Return an rtx for the static chain for FNDECL.  If INCOMING_P is true,
989
       then it should be for the callee; otherwise for the caller.  */
990
    rtx (*static_chain) (const_tree fndecl, bool incoming_p);
991
 
992
    /* Fill in the trampoline at MEM with a call to FNDECL and a
993
       static chain value of CHAIN.  */
994
    void (*trampoline_init) (rtx mem, tree fndecl, rtx chain);
995
 
996
    /* Adjust the address of the trampoline in a target-specific way.  */
997
    rtx (*trampoline_adjust_address) (rtx addr);
998
  } calls;
999
 
1000
  /* Return the diagnostic message string if conversion from FROMTYPE
1001
     to TOTYPE is not allowed, NULL otherwise.  */
1002
  const char *(*invalid_conversion) (const_tree fromtype, const_tree totype);
1003
 
1004
  /* Return the diagnostic message string if the unary operation OP is
1005
     not permitted on TYPE, NULL otherwise.  */
1006
  const char *(*invalid_unary_op) (int op, const_tree type);
1007
 
1008
  /* Return the diagnostic message string if the binary operation OP
1009
     is not permitted on TYPE1 and TYPE2, NULL otherwise.  */
1010
  const char *(*invalid_binary_op) (int op, const_tree type1, const_tree type2);
1011
 
1012
  /* Return the diagnostic message string if TYPE is not valid as a
1013
     function parameter type, NULL otherwise.  */
1014
  const char *(*invalid_parameter_type) (const_tree type);
1015
 
1016
  /* Return the diagnostic message string if TYPE is not valid as a
1017
     function return type, NULL otherwise.  */
1018
  const char *(*invalid_return_type) (const_tree type);
1019
 
1020
  /* If values of TYPE are promoted to some other type when used in
1021
     expressions (analogous to the integer promotions), return that type,
1022
     or NULL_TREE otherwise.  */
1023
  tree (*promoted_type) (const_tree type);
1024
 
1025
  /* Convert EXPR to TYPE, if target-specific types with special conversion
1026
     rules are involved.  Return the converted expression, or NULL to apply
1027
     the standard conversion rules.  */
1028
  tree (*convert_to_type) (tree type, tree expr);
1029
 
1030
  /* Return the array of IRA cover classes for the current target.  */
1031
  const enum reg_class *(*ira_cover_classes) (void);
1032
 
1033
  /* Return the class for a secondary reload, and fill in extra information.  */
1034
  enum reg_class (*secondary_reload) (bool, rtx, enum reg_class,
1035
                                      enum machine_mode,
1036
                                      secondary_reload_info *);
1037
 
1038
  /* This target hook allows the backend to perform additional
1039
     processing while initializing for variable expansion.  */
1040
  void (* expand_to_rtl_hook) (void);
1041
 
1042
  /* This target hook allows the backend to perform additional
1043
     instantiations on rtx that are not actually in insns yet,
1044
     but will be later.  */
1045
  void (* instantiate_decls) (void);
1046
 
1047
  /* Return true if is OK to use a hard register REGNO as scratch register
1048
     in peephole2.  */
1049
  bool (* hard_regno_scratch_ok) (unsigned int regno);
1050
 
1051
  /* Return the smallest number of different values for which it is best to
1052
     use a jump-table instead of a tree of conditional branches.  */
1053
  unsigned int (* case_values_threshold) (void);
1054
 
1055
  /* Retutn true if a function must have and use a frame pointer.  */
1056
  bool (* frame_pointer_required) (void);
1057
 
1058
  /* Returns true if the compiler is allowed to try to replace register number
1059
     from-reg with register number to-reg.  */
1060
  bool (* can_eliminate) (const int, const int);
1061
 
1062
  /* Functions specific to the C family of frontends.  */
1063
  struct c {
1064
    /* Return machine mode for non-standard suffix
1065
       or VOIDmode if non-standard suffixes are unsupported.  */
1066
    enum machine_mode (*mode_for_suffix) (char);
1067
  } c;
1068
 
1069
  /* Functions specific to the C++ frontend.  */
1070
  struct cxx {
1071
    /* Return the integer type used for guard variables.  */
1072
    tree (*guard_type) (void);
1073
    /* Return true if only the low bit of the guard should be tested.  */
1074
    bool (*guard_mask_bit) (void);
1075
    /* Returns the size of the array cookie for an array of type.  */
1076
    tree (*get_cookie_size) (tree);
1077
    /* Returns true if the element size should be stored in the
1078
       array cookie.  */
1079
    bool (*cookie_has_size) (void);
1080
    /* Allows backends to perform additional processing when
1081
       deciding if a class should be exported or imported.  */
1082
    int (*import_export_class) (tree, int);
1083
    /* Returns true if constructors and destructors return "this".  */
1084
    bool (*cdtor_returns_this) (void);
1085
    /* Returns true if the key method for a class can be an inline
1086
       function, so long as it is not declared inline in the class
1087
       itself.  Returning true is the behavior required by the Itanium
1088
       C++ ABI.  */
1089
    bool (*key_method_may_be_inline) (void);
1090
    /* DECL is a virtual table, virtual table table, typeinfo object,
1091
       or other similar implicit class data object that will be
1092
       emitted with external linkage in this translation unit.  No ELF
1093
       visibility has been explicitly specified.  If the target needs
1094
       to specify a visibility other than that of the containing class,
1095
       use this hook to set DECL_VISIBILITY and
1096
       DECL_VISIBILITY_SPECIFIED.  */
1097
    void (*determine_class_data_visibility) (tree decl);
1098
    /* Returns true (the default) if virtual tables and other
1099
       similar implicit class data objects are always COMDAT if they
1100
       have external linkage.  If this hook returns false, then
1101
       class data for classes whose virtual table will be emitted in
1102
       only one translation unit will not be COMDAT.  */
1103
    bool (*class_data_always_comdat) (void);
1104
    /* Returns true (the default) if the RTTI for the basic types,
1105
       which is always defined in the C++ runtime, should be COMDAT;
1106
       false if it should not be COMDAT.  */
1107
    bool (*library_rtti_comdat) (void);
1108
    /* Returns true if __aeabi_atexit should be used to register static
1109
       destructors.  */
1110
    bool (*use_aeabi_atexit) (void);
1111
    /* Returns true if target may use atexit in the same manner as
1112
    __cxa_atexit  to register static destructors.  */
1113
    bool (*use_atexit_for_cxa_atexit) (void);
1114
    /* TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that
1115
       has just been defined.  Use this hook to make adjustments to the
1116
       class  (eg, tweak visibility or perform any other required
1117
       target modifications).  */
1118
    void (*adjust_class_at_definition) (tree type);
1119
  } cxx;
1120
 
1121
  /* Functions and data for emulated TLS support.  */
1122
  struct emutls {
1123
    /* Name of the address and common functions.  */
1124
    const char *get_address;
1125
    const char *register_common;
1126
 
1127
    /* Prefixes for proxy variable and template.  */
1128
    const char *var_section;
1129
    const char *tmpl_section;
1130
 
1131
    /* Prefixes for proxy variable and template.  */
1132
    const char *var_prefix;
1133
    const char *tmpl_prefix;
1134
 
1135
    /* Function to generate field definitions of the proxy variable.  */
1136
    tree (*var_fields) (tree, tree *);
1137
 
1138
    /* Function to initialize a proxy variable.  */
1139
    tree (*var_init) (tree, tree, tree);
1140
 
1141
    /* Whether we are allowed to alter the usual alignment of the
1142
       proxy variable.  */
1143
    bool var_align_fixed;
1144
 
1145
    /* Whether we can emit debug information for TLS vars.  */
1146
    bool debug_form_tls_address;
1147
  } emutls;
1148
 
1149
  struct target_option_hooks {
1150
    /* Function to validate the attribute((option(...))) strings or NULL.  If
1151
       the option is validated, it is assumed that DECL_FUNCTION_SPECIFIC will
1152
       be filled in in the function decl node.  */
1153
    bool (*valid_attribute_p) (tree, tree, tree, int);
1154
 
1155
    /* Function to save any extra target state in the target options
1156
       structure.  */
1157
    void (*save) (struct cl_target_option *);
1158
 
1159
    /* Function to restore any extra target state from the target options
1160
       structure.  */
1161
    void (*restore) (struct cl_target_option *);
1162
 
1163
    /* Function to print any extra target state from the target options
1164
       structure.  */
1165
    void (*print) (FILE *, int, struct cl_target_option *);
1166
 
1167
    /* Function to parse arguments to be validated for #pragma option, and to
1168
       change the state if the options are valid.  If the first argument is
1169
       NULL, the second argument specifies the default options to use.  Return
1170
       true if the options are valid, and set the current state.  */
1171
    bool (*pragma_parse) (tree, tree);
1172
 
1173
    /* Function to determine if one function can inline another function.  */
1174
    bool (*can_inline_p) (tree, tree);
1175
  } target_option;
1176
 
1177
  /* For targets that need to mark extra registers as live on entry to
1178
     the function, they should define this target hook and set their
1179
     bits in the bitmap passed in. */
1180
  void (*live_on_entry) (bitmap);
1181
 
1182
  /* True if unwinding tables should be generated by default.  */
1183
  bool unwind_tables_default;
1184
 
1185
  /* Leave the boolean fields at the end.  */
1186
 
1187
  /* True if arbitrary sections are supported.  */
1188
  bool have_named_sections;
1189
 
1190
  /* True if we can create zeroed data by switching to a BSS section
1191
     and then using ASM_OUTPUT_SKIP to allocate the space.  */
1192
  bool have_switchable_bss_sections;
1193
 
1194
  /* True if "native" constructors and destructors are supported,
1195
     false if we're using collect2 for the job.  */
1196
  bool have_ctors_dtors;
1197
 
1198
  /* True if thread-local storage is supported.  */
1199
  bool have_tls;
1200
 
1201
  /* True if a small readonly data section is supported.  */
1202
  bool have_srodata_section;
1203
 
1204
  /* True if EH frame info sections should be zero-terminated.  */
1205
  bool terminate_dw2_eh_frame_info;
1206
 
1207
  /* True if #NO_APP should be emitted at the beginning of
1208
     assembly output.  */
1209
  bool file_start_app_off;
1210
 
1211
  /* True if output_file_directive should be called for main_input_filename
1212
     at the beginning of assembly output.  */
1213
  bool file_start_file_directive;
1214
 
1215
  /* True if #pragma extern_prefix is to be supported.  */
1216
  bool handle_pragma_extern_prefix;
1217
 
1218
  /* True if the target is allowed to reorder memory accesses unless
1219
     synchronization is explicitly requested.  */
1220
  bool relaxed_ordering;
1221
 
1222
  /* Returns true if we should generate exception tables for use with the
1223
     ARM EABI.  The effects the encoding of function exception specifications.
1224
   */
1225
  bool arm_eabi_unwinder;
1226
 
1227
  /* Leave the boolean fields at the end.  */
1228
};
1229
 
1230
extern struct gcc_target targetm;
1231
 
1232
struct gcc_targetcm {
1233
  /* Handle target switch CODE (an OPT_* value).  ARG is the argument
1234
     passed to the switch; it is NULL if no argument was.  VALUE is the
1235
     value of ARG if CODE specifies a UInteger option, otherwise it is
1236
     1 if the positive form of the switch was used and 0 if the negative
1237
     form was.  Return true if the switch was valid.  */
1238
  bool (*handle_c_option) (size_t code, const char *arg, int value);
1239
};
1240
 
1241
/* Each target can provide their own.  */
1242
extern struct gcc_targetcm targetcm;
1243
 
1244
#endif /* GCC_TARGET_H */

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